Move Handlebars.php helpers to separate classes

src/mibew/libs/classes/Mibew/Handlebars/BlockStorage.php

@@ -0,0 +1,77 @@
+<?php
+/*
+ * This file is a part of Mibew Messenger.
+ *
+ * Copyright 2005-2014 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+namespace Mibew\Handlebars;
+
+/**
+ * A storage for overridable blocks' content.
+ */
+class BlockStorage
+{
+    /**
+     * Associative array of blocks. The keys are blocks names and the values are
+     * blocks content.
+     *
+     * @type string[]
+     */
+    protected $blocks = array();
+
+    /**
+     * Gets content of a block.
+     *
+     * @param string $name Block's name.
+     * @return string Block's content.
+     */
+    public function get($name)
+    {
+        return isset($this->blocks[$name]) ? $this->blocks[$name] : false;
+    }
+
+    /**
+     * Sets content of a block.
+     *
+     * @param string $name Block's name.
+     * @param string $content Block's content.
+     */
+    public function set($name, $content)
+    {
+        $this->blocks[$name] = $content;
+    }
+
+    /**
+     * Checks if a block exists in the storage.
+     *
+     * @param string $name Block's name
+     * @return boolean
+     */
+    public function has($name)
+    {
+        return isset($this->blocks[$name]);
+    }
+
+    /**
+     * Removes block from the storage.
+     *
+     * @param string $name Block's name.
+     */
+    public function remove($name)
+    {
+        unset($this->blocks[$name]);
+    }
+}

src/mibew/libs/classes/Mibew/Handlebars/Helper/AbstractBlockHelper.php

@@ -0,0 +1,43 @@
+<?php
+/*
+ * This file is a part of Mibew Messenger.
+ *
+ * Copyright 2005-2014 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+namespace Mibew\Handlebars\Helper;
+
+use Mibew\Handlebars\BlockStorage;
+
+/**
+ * Contains base functionality for all helpers related with blocks overriding.
+ */
+abstract class AbstractBlockHelper
+{
+    /**
+     * @var BlockStorage
+     */
+    protected $blocksStorage;
+
+    /**
+     * Helper's constructor.
+     *
+     * @param BlockStorage $storage A Blocks context instance
+     */
+    public function __construct(BlockStorage $storage)
+    {
+        $this->blocksStorage = $storage;
+    }
+}

src/mibew/libs/classes/Mibew/Handlebars/Helper/BlockHelper.php

@@ -0,0 +1,58 @@
+<?php
+/*
+ * This file is a part of Mibew Messenger.
+ *
+ * Copyright 2005-2014 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+namespace Mibew\Handlebars\Helper;
+
+use Handlebars\Context;
+use Handlebars\Helper as HelperInterface;
+use Handlebars\Template;
+
+/**
+ * A helper for defining default content of a block.
+ *
+ * Example of usage:
+ * <code>
+ *   {{#block "blockName"}}
+ *     Default content for the block
+ *   {{/block}}
+ * </code>
+ */
+class BlockHelper extends AbstractBlockHelper implements HelperInterface
+{
+    /**
+     * {@inheritdoc}
+     */
+    public function execute(Template $template, Context $context, $args, $source)
+    {
+        // Get block name
+        $parsed_args = $template->parseArguments($args);
+        if (empty($parsed_args)) {
+            return '';
+        }
+        $block_name = $context->get(array_shift($parsed_args));
+
+        // If the block is not overridden render and show the default value
+        if (!$this->blocksStorage->has($block_name)) {
+            return $template->render($context);
+        }
+
+        // Show overridden content
+        return $this->blocksStorage->get($block_name);
+    }
+}

src/mibew/libs/classes/Mibew/Handlebars/Helper/CsrfTokenInUrlHelper.php

@@ -0,0 +1,44 @@
+<?php
+/*
+ * This file is a part of Mibew Messenger.
+ *
+ * Copyright 2005-2014 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+namespace Mibew\Handlebars\Helper;
+
+use Handlebars\Context;
+use Handlebars\Helper as HelperInterface;
+use Handlebars\SafeString;
+use Handlebars\Template;
+
+/**
+ * Generates CSRF token prepared to insert in URLs.
+ *
+ * Example of usage:
+ * <code>
+ *   {{csrfTokenInUrl}}
+ * </code>
+ */
+class CsrfTokenInUrlHelper implements HelperInterface
+{
+    /**
+     * {@inheritdoc}
+     */
+    public function execute(Template $template, Context $context, $args, $source)
+    {
+        return new SafeString(get_csrf_token_in_url());
+    }
+}

src/mibew/libs/classes/Mibew/Handlebars/Helper/CsrfTokenInputHelper.php

@@ -0,0 +1,44 @@
+<?php
+/*
+ * This file is a part of Mibew Messenger.
+ *
+ * Copyright 2005-2014 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+namespace Mibew\Handlebars\Helper;
+
+use Handlebars\Context;
+use Handlebars\Helper as HelperInterface;
+use Handlebars\SafeString;
+use Handlebars\Template;
+
+/**
+ * Generates markup with hidden input tag for CSRF token.
+ *
+ * Example of usage:
+ * <code>
+ *   {{csrfTokenInput}}
+ * </code>
+ */
+class CsrfTokenInputHelper implements HelperInterface
+{
+    /**
+     * {@inheritdoc}
+     */
+    public function execute(Template $template, Context $context, $args, $source)
+    {
+        return new SafeString(get_csrf_token_input());
+    }
+}

src/mibew/libs/classes/Mibew/Handlebars/Helper/CutStringHelper.php

@@ -0,0 +1,51 @@
+<?php
+/*
+ * This file is a part of Mibew Messenger.
+ *
+ * Copyright 2005-2014 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+namespace Mibew\Handlebars\Helper;
+
+use Handlebars\Context;
+use Handlebars\Helper as HelperInterface;
+use Handlebars\Template;
+
+/**
+ * Cut string if it exceeds specified length.
+ *
+ * Example of usage:
+ * <code>
+ *   {{cutString string length}}
+ * </code>
+ */
+class CutStringHelper implements HelperInterface
+{
+    /**
+     * {@inheritdoc}
+     */
+    public function execute(Template $template, Context $context, $args, $source)
+    {
+        $parsed_args = $template->parseArguments($args);
+        if (empty($parsed_args) || count($parsed_args) < 2) {
+            return '';
+        }
+
+        $string = $context->get($parsed_args[0]);
+        $length = intval($context->get($parsed_args[1]));
+
+        return substr($string, 0, $length);
+    }
+}

src/mibew/libs/classes/Mibew/Handlebars/Helper/ExtendsHelper.php

@@ -0,0 +1,66 @@
+<?php
+/*
+ * This file is a part of Mibew Messenger.
+ *
+ * Copyright 2005-2014 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+namespace Mibew\Handlebars\Helper;
+
+use Handlebars\Context;
+use Handlebars\Helper as HelperInterface;
+use Handlebars\Template;
+
+/**
+ * A helper for templates inheritance.
+ *
+ * Example of usage:
+ * <code>
+ *   {{#extends "parentTemplateName"}}
+ *     {{#override "blockName"}}
+ *       Overridden first block
+ *     {{/override}}
+ *
+ *     {{#override "anotherBlockName"}}
+ *       Overridden second block
+ *     {{/override}}
+ *   {{/extends}}
+ * </code>
+ */
+class ExtendsHelper implements HelperInterface
+{
+    /**
+     * {@inheritdoc}
+     */
+    public function execute(Template $template, Context $context, $args, $source)
+    {
+        // Get name of the parent template
+        $parsed_args = $template->parseArguments($args);
+        if (empty($parsed_args)) {
+            return '';
+        }
+        $parent_template = $context->get(array_shift($parsed_args));
+
+        // Render content inside "extends" block to override blocks
+        $template->render($context);
+
+        // We need another instance of \Handlebars\Template to render parent
+        // template. It can be got from Handlebars engine, so get the engine.
+        $handlebars = $template->getEngine();
+
+        // Render the parent template
+        return $handlebars->render($parent_template, $context);
+    }
+}

src/mibew/libs/classes/Mibew/Handlebars/Helper/FormatDateDiffHelper.php

@@ -0,0 +1,50 @@
+<?php
+/*
+ * This file is a part of Mibew Messenger.
+ *
+ * Copyright 2005-2014 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+namespace Mibew\Handlebars\Helper;
+
+use Handlebars\Context;
+use Handlebars\Helper as HelperInterface;
+use Handlebars\Template;
+
+/**
+ * Format date difference using internal format.
+ *
+ * Example of usage:
+ * <code>
+ *   {{formatDateDiff seconds}}
+ * </code>
+ */
+class FormatDateDiffHelper implements HelperInterface
+{
+    /**
+     * {@inheritdoc}
+     */
+    public function execute(Template $template, Context $context, $args, $source)
+    {
+        $parsed_args = $template->parseArguments($args);
+        if (empty($parsed_args)) {
+            return '';
+        }
+
+        $seconds = intval($context->get($parsed_args[0]));
+
+        return date_diff_to_text($seconds);
+    }
+}

src/mibew/libs/classes/Mibew/Handlebars/Helper/FormatDateHelper.php

@@ -0,0 +1,50 @@
+<?php
+/*
+ * This file is a part of Mibew Messenger.
+ *
+ * Copyright 2005-2014 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+namespace Mibew\Handlebars\Helper;
+
+use Handlebars\Context;
+use Handlebars\Helper as HelperInterface;
+use Handlebars\Template;
+
+/**
+ * Format date using internal format.
+ *
+ * Example of usage:
+ * <code>
+ *   {{formatDate unixTimestamp}}
+ * </code>
+ */
+class FormatDateHelper implements HelperInterface
+{
+    /**
+     * {@inheritdoc}
+     */
+    public function execute(Template $template, Context $context, $args, $source)
+    {
+        $parsed_args = $template->parseArguments($args);
+        if (empty($parsed_args)) {
+            return '';
+        }
+
+        $timestamp = intval($context->get($parsed_args[0]));
+
+        return date_to_text($timestamp);
+    }
+}

src/mibew/libs/classes/Mibew/Handlebars/Helper/GeneratePaginationHelper.php

@@ -0,0 +1,67 @@
+<?php
+/*
+ * This file is a part of Mibew Messenger.
+ *
+ * Copyright 2005-2014 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+namespace Mibew\Handlebars\Helper;
+
+use Handlebars\Context;
+use Handlebars\Helper as HelperInterface;
+use Handlebars\SafeString;
+use Handlebars\Template;
+
+/**
+ * Generates pagination block.
+ *
+ * Example of usage:
+ * <code>
+ *   {{generatePagination stylePath paginationInfo bottom}}
+ * </code>
+ * where:
+ *   - "stylePath" is expression for path to current style.
+ *   - "paginationInfo" is 'info' key from the result of setup_pagination
+ *     function.
+ *   - "bottom": optional argument that indicate if pagination block shoud
+ *     be generated for a page bottom or not. If specified and equal to
+ *     string "false" then boolean false will be passed into
+ *     generate_pagination. In all other cases boolean true will be used.
+ */
+class GeneratePaginationHelper implements HelperInterface
+{
+    /**
+     * {@inheritdoc}
+     */
+    public function execute(Template $template, Context $context, $args, $source)
+    {
+        $parsed_args = $template->parseArguments($args);
+        if (empty($parsed_args) || count($parsed_args) < 2) {
+            return '';
+        }
+
+        $stylePath = $context->get($parsed_args[0]);
+        $pagination_info = $context->get($parsed_args[1]);
+        $bottom = empty($parsed_args[2]) ? true : $context->get($parsed_args[2]);
+
+        $pagination = generate_pagination(
+            $stylePath,
+            $pagination_info,
+            ($bottom === "false") ? false : true
+        );
+
+        return new SafeString($pagination);
+    }
+}

src/mibew/libs/classes/Mibew/Handlebars/Helper/IfAnyHelper.php

@@ -0,0 +1,82 @@
+<?php
+/*
+ * This file is a part of Mibew Messenger.
+ *
+ * Copyright 2005-2014 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+namespace Mibew\Handlebars\Helper;
+
+use Handlebars\Context;
+use Handlebars\Helper as HelperInterface;
+use Handlebars\String;
+use Handlebars\Template;
+
+/**
+ * Conditional helper that checks if at least one argumet can be treated as
+ * "true" value.
+ *
+ * Example of usage:
+ * <code>
+ *   {{#ifAny first second third}}
+ *     At least one of argument can be threated as "true".
+ *   {{else}}
+ *     All values are "falsy"
+ *   {{/ifAny}}
+ * </code>
+ */
+class IfAnyHelper implements HelperInterface
+{
+    /**
+     * {@inheritdoc}
+     */
+    public function execute(Template $template, Context $context, $args, $source)
+    {
+        $parsed_args = $template->parseArguments($args);
+        if (empty($parsed_args)) {
+            return '';
+        }
+
+        $condition = false;
+        foreach ($parsed_args as $parsed_arg) {
+            $value = $context->get($parsed_arg);
+
+            if ($value instanceof String) {
+                // We need to get internal string. Casting any object of
+                // \Handlebars\String will have positive result even for those
+                // with empty internal strings.
+                $value = $value->getString();
+            }
+
+            if ($value) {
+                $condition = true;
+                break;
+            }
+        }
+
+        if ($condition) {
+            $template->setStopToken('else');
+            $buffer = $template->render($context);
+            $template->setStopToken(false);
+        } else {
+            $template->setStopToken('else');
+            $template->discard();
+            $template->setStopToken(false);
+            $buffer = $template->render($context);
+        }
+
+        return $buffer;
+    }
+}

src/mibew/libs/classes/Mibew/Handlebars/Helper/IfEqualHelper.php

@@ -0,0 +1,65 @@
+<?php
+/*
+ * This file is a part of Mibew Messenger.
+ *
+ * Copyright 2005-2014 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+namespace Mibew\Handlebars\Helper;
+
+use Handlebars\Context;
+use Handlebars\Helper as HelperInterface;
+use Handlebars\Template;
+
+/**
+ * Conditional helper that checks if two values are equal or not.
+ *
+ * Example of usage:
+ * <code>
+ *   {{#ifEqual first second}}
+ *     The first argument is equal to the second one.
+ *   {{else}}
+ *     The arguments are not equal.
+ *   {{/ifEqual}}
+ * </code>
+ */
+class IfEqualHelper implements HelperInterface
+{
+    /**
+     * {@inheritdoc}
+     */
+    public function execute(Template $template, Context $context, $args, $source)
+    {
+        $parsed_args = $template->parseArguments($args);
+        if (empty($parsed_args) || count($parsed_args) < 2) {
+            return '';
+        }
+
+        $condition = ($context->get($parsed_args[0]) == $context->get($parsed_args[1]));
+
+        if ($condition) {
+            $template->setStopToken('else');
+            $buffer = $template->render($context);
+            $template->setStopToken(false);
+        } else {
+            $template->setStopToken('else');
+            $template->discard();
+            $template->setStopToken(false);
+            $buffer = $template->render($context);
+        }
+
+        return $buffer;
+    }
+}

src/mibew/libs/classes/Mibew/Handlebars/Helper/IfEvenHelper.php

@@ -0,0 +1,65 @@
+<?php
+/*
+ * This file is a part of Mibew Messenger.
+ *
+ * Copyright 2005-2014 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+namespace Mibew\Handlebars\Helper;
+
+use Handlebars\Context;
+use Handlebars\Helper as HelperInterface;
+use Handlebars\Template;
+
+/**
+ * Conditional helper that checks if specified argument is even or not.
+ *
+ * Example of usage:
+ * <code>
+ *   {{#ifEven value}}
+ *     The value is even.
+ *   {{else}}
+ *     The value is odd.
+ *   {{/ifEven}}
+ * </code>
+ */
+class IfEvenHelper implements HelperInterface
+{
+    /**
+     * {@inheritdoc}
+     */
+    public function execute(Template $template, Context $context, $args, $source)
+    {
+        $parsed_args = $template->parseArguments($args);
+        if (empty($parsed_args)) {
+            return '';
+        }
+
+        $condition = ($context->get($parsed_args[0]) % 2 == 0);
+
+        if ($condition) {
+            $template->setStopToken('else');
+            $buffer = $template->render($context);
+            $template->setStopToken(false);
+        } else {
+            $template->setStopToken('else');
+            $template->discard();
+            $template->setStopToken(false);
+            $buffer = $template->render($context);
+        }
+
+        return $buffer;
+    }
+}

src/mibew/libs/classes/Mibew/Handlebars/Helper/IfOddHelper.php

@@ -0,0 +1,66 @@
+<?php
+/*
+ * This file is a part of Mibew Messenger.
+ *
+ * Copyright 2005-2014 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+namespace Mibew\Handlebars\Helper;
+
+use Handlebars\Context;
+use Handlebars\Helper as HelperInterface;
+use Handlebars\String;
+use Handlebars\Template;
+
+/**
+ * Conditional helper that checks if specified argument is odd or not.
+ *
+ * Example of usage:
+ * <code>
+ *   {{#ifOdd value}}
+ *     The value is odd.
+ *   {{else}}
+ *     The value is even.
+ *   {{/ifOdd}}
+ * </code>
+ */
+class IfOddHelper implements HelperInterface
+{
+    /**
+     * {@inheritdoc}
+     */
+    public function execute(Template $template, Context $context, $args, $source)
+    {
+        $parsed_args = $template->parseArguments($args);
+        if (empty($parsed_args)) {
+            return '';
+        }
+
+        $condition = ($context->get($parsed_args[0]) % 2 == 1);
+
+        if ($condition) {
+            $template->setStopToken('else');
+            $buffer = $template->render($context);
+            $template->setStopToken(false);
+        } else {
+            $template->setStopToken('else');
+            $template->discard();
+            $template->setStopToken(false);
+            $buffer = $template->render($context);
+        }
+
+        return $buffer;
+    }
+}

src/mibew/libs/classes/Mibew/Handlebars/Helper/IfOverriddenHelper.php

@@ -0,0 +1,66 @@
+<?php
+/*
+ * This file is a part of Mibew Messenger.
+ *
+ * Copyright 2005-2014 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+namespace Mibew\Handlebars\Helper;
+
+use Handlebars\Context;
+use Handlebars\Helper as HelperInterface;
+use Handlebars\Template;
+
+/**
+ * Conditional helper that checks if block overridden or not.
+ *
+ * Example of usage:
+ * <code>
+ *   {{#ifOverridden "blockName"}}
+ *     The block was overridden
+ *   {{else}}
+ *     The block was not overridden
+ *   {{/ifOverriden}}
+ * </code>
+ */
+class IfOverriddenHelper extends AbstractBlockHelper implements HelperInterface
+{
+    /**
+     * {@inheritdoc}
+     */
+    public function execute(Template $template, Context $context, $args, $source)
+    {
+        // Get block name
+        $parsed_args = $template->parseArguments($args);
+        if (empty($parsed_args)) {
+            return '';
+        }
+        $block_name = $context->get(array_shift($parsed_args));
+
+        // Check condition and render blocks
+        if ($this->blocksStorage->has($block_name)) {
+            $template->setStopToken('else');
+            $buffer = $template->render($context);
+            $template->setStopToken(false);
+        } else {
+            $template->setStopToken('else');
+            $template->discard();
+            $template->setStopToken(false);
+            $buffer = $template->render($context);
+        }
+
+        return $buffer;
+    }
+}

src/mibew/libs/classes/Mibew/Handlebars/Helper/JsStringHelper.php

@@ -0,0 +1,44 @@
+<?php
+/*
+ * This file is a part of Mibew Messenger.
+ *
+ * Copyright 2005-2014 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+namespace Mibew\Handlebars\Helper;
+
+use Handlebars\Context;
+use Handlebars\Helper as HelperInterface;
+use Handlebars\Template;
+
+/**
+ * Escapes special characters to use result as a valid JavaScript string
+ * enclosed with single quotes (') or duouble quotes (").
+ *
+ * Example of usage:
+ * <code>
+ *   var a = "{{#jsString}}some string to escape{{/jsString}}";
+ * </code>
+ */
+class JsStringHelper implements HelperInterface
+{
+    /**
+     * {@inheritdoc}
+     */
+    public function execute(Template $template, Context $context, $args, $source)
+    {
+        return str_replace("\n", "\\n", addslashes($template->render($context)));
+    }
+}

src/mibew/libs/classes/Mibew/Handlebars/Helper/L10nHelper.php

@@ -0,0 +1,81 @@
+<?php
+/*
+ * This file is a part of Mibew Messenger.
+ *
+ * Copyright 2005-2014 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+namespace Mibew\Handlebars\Helper;
+
+use Handlebars\Context;
+use Handlebars\Helper as HelperInterface;
+use Handlebars\SafeString;
+use Handlebars\Template;
+
+/**
+ * A helper for string localization.
+ *
+ * Example of usage:
+ * <code>
+ *   {{l10n "localization.string" arg1 arg2 arg3}}
+ * </code>
+ * where:
+ *   - "localization.string" is localization constant.
+ *   - arg* are arguments that will be passed to getlocal function. There
+ *     can be arbitrary number of such arguments.
+ */
+class L10nHelper implements HelperInterface
+{
+    /**
+     * {@inheritdoc}
+     */
+    public function execute(Template $template, Context $context, $args, $source)
+    {
+        // Check if there is at least one argument
+        $parsed_arguments = $template->parseArguments($args);
+        if (empty($parsed_arguments)) {
+            return '';
+        }
+
+        $text = $context->get(array_shift($parsed_arguments));
+
+        // We need to escape extra arguments passed to the helper. Thus we need
+        // to get escape function and its arguments from the template engine.
+        $escape_func = $template->getEngine()->getEscape();
+        $escape_args = $template->getEngine()->getEscapeArgs();
+
+        // Check if there are any other arguments passed into helper and escape
+        // them.
+        $local_args = array();
+        foreach ($parsed_arguments as $parsed_argument) {
+            // Get locale argument string and add it to escape function
+            // arguments.
+            array_unshift($escape_args, $context->get($parsed_argument));
+
+            // Escape locale argument's value
+            $local_args[] = call_user_func_array(
+                $escape_func,
+                array_values($escape_args)
+            );
+
+            // Remove locale argument's value from escape function argument
+            array_shift($escape_args);
+        }
+
+        $result = getlocal($text, $local_args);
+
+        return new SafeString($result);
+    }
+}

src/mibew/libs/classes/Mibew/Handlebars/Helper/OverrideHelper.php

@@ -0,0 +1,64 @@
+<?php
+/*
+ * This file is a part of Mibew Messenger.
+ *
+ * Copyright 2005-2014 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+namespace Mibew\Handlebars\Helper;
+
+use Handlebars\Context;
+use Handlebars\Helper as HelperInterface;
+use Handlebars\Template;
+
+/**
+ * A helper for overriding content of a block.
+ *
+ * Example of usage:
+ * <code>
+ *   {{#extends "parentTemplateName"}}
+ *     {{#override "blockName"}}
+ *       Overridden first block
+ *     {{/override}}
+ *
+ *     {{#override "anotherBlockName"}}
+ *       Overridden second block
+ *     {{/override}}
+ *   {{/extends}}
+ * </code>
+ */
+class OverrideHelper extends AbstractBlockHelper implements HelperInterface
+{
+    /**
+     * {@inheritdoc}
+     */
+    public function execute(Template $template, Context $context, $args, $source)
+    {
+        // Get block name
+        $parsed_args = $template->parseArguments($args);
+        if (empty($parsed_args)) {
+            return '';
+        }
+        $block_name = $context->get(array_shift($parsed_args));
+
+        // We need to provide unlimited inheritence level. Rendering is started
+        // from the deepest level template. If the content is in the block
+        // storage it is related with the deepest level template. Thus we do not
+        // need to override it.
+        if (!$this->blocksStorage->has($block_name)) {
+            $this->blocksStorage->set($block_name, $template->render($context));
+        }
+    }
+}

src/mibew/libs/classes/Mibew/Handlebars/Helper/RepeatHelper.php

@@ -0,0 +1,51 @@
+<?php
+/*
+ * This file is a part of Mibew Messenger.
+ *
+ * Copyright 2005-2014 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+namespace Mibew\Handlebars\Helper;
+
+use Handlebars\Context;
+use Handlebars\Helper as HelperInterface;
+use Handlebars\Template;
+
+/**
+ * Helper for repeating content.
+ *
+ * Example of usage:
+ * <code>
+ *   {{#repeat times}}content to repeat{{/repeat}}
+ * </code>
+ */
+class RepeatHelper implements HelperInterface
+{
+    /**
+     * {@inheritdoc}
+     */
+    public function execute(Template $template, Context $context, $args, $source)
+    {
+        $parsed_args = $template->parseArguments($args);
+        if (empty($parsed_args)) {
+            return '';
+        }
+
+        $times = intval($context->get($parsed_args[0]));
+        $string = $template->render($context);
+
+        return str_repeat($string, $times);
+    }
+}

src/mibew/libs/classes/Mibew/Handlebars/Helper/ReplaceHelper.php

@@ -0,0 +1,52 @@
+<?php
+/*
+ * This file is a part of Mibew Messenger.
+ *
+ * Copyright 2005-2014 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+namespace Mibew\Handlebars\Helper;
+
+use Handlebars\Context;
+use Handlebars\Helper as HelperInterface;
+use Handlebars\Template;
+
+/**
+ * Helper for replacing substrings.
+ *
+ * Example of usage:
+ * <code>
+ *   {{#replace search replacement}}target content{{/replace}}
+ * </code>
+ */
+class ReplaceHelper implements HelperInterface
+{
+    /**
+     * {@inheritdoc}
+     */
+    public function execute(Template $template, Context $context, $args, $source)
+    {
+        $parsed_args = $template->parseArguments($args);
+        if (empty($parsed_args) || count($parsed_args) < 2) {
+            return '';
+        }
+
+        $search = $context->get($parsed_args[0]);
+        $replacement = $context->get($parsed_args[1]);
+        $subject = $template->render($context);
+
+        return str_replace($search, $replacement, $subject);
+    }
+}

src/mibew/libs/classes/Mibew/Handlebars/Helper/UnlessOverriddenHelper.php

@@ -0,0 +1,66 @@
+<?php
+/*
+ * This file is a part of Mibew Messenger.
+ *
+ * Copyright 2005-2014 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+namespace Mibew\Handlebars\Helper;
+
+use Handlebars\Context;
+use Handlebars\Helper as HelperInterface;
+use Handlebars\Template;
+
+/**
+ * Conditional helper that checks if block overridden or not.
+ *
+ * Example of usage:
+ * <code>
+ *   {{#unlessOverridden "blockName"}}
+ *     The block was not overridden
+ *   {{else}}
+ *     The block was overridden
+ *   {{/unlessOverriden}}
+ * </code>
+ */
+class UnlessOverriddenHelper extends AbstractBlockHelper implements HelperInterface
+{
+    /**
+     * {@inheritdoc}
+     */
+    public function execute(Template $template, Context $context, $args, $source)
+    {
+        // Get block name
+        $parsed_args = $template->parseArguments($args);
+        if (empty($parsed_args)) {
+            return '';
+        }
+        $block_name = $context->get(array_shift($parsed_args));
+
+        // Check condition and render blocks
+        if (!$this->blocksStorage->has($block_name)) {
+            $template->setStopToken('else');
+            $buffer = $template->render($context);
+            $template->setStopToken(false);
+        } else {
+            $template->setStopToken('else');
+            $template->discard();
+            $template->setStopToken(false);
+            $buffer = $template->render($context);
+        }
+
+        return $buffer;
+    }
+}

src/mibew/libs/classes/Mibew/Handlebars/HelpersSet.php

@@ -20,25 +20,16 @@
 namespace Mibew\Handlebars;
 
 /**
- * Set of helpers to for server side templates
+ * Represents a set of default helpers for server side templates.
  */
 class HelpersSet
 {
     /**
-     * Contains an instance of helpers set.
+     * Contains a list of helpers.
      *
-     * @var \Mibew\Handlebars\HelpersSet
+     * @var array()
      */
-    protected static $instance = null;
-
-    /**
-     * Storage for overridable blocks' content.
-     *
-     * This storage is used by "block" helper and "override" helper.
-     *
-     * @var array
-     */
-    protected $blocksStorage = array();
+    protected static $helpers = null;
 
     /**
      * Returns a set of handlebars helpers.
@@ -48,596 +39,31 @@ class HelpersSet
      */
     public static function getHelpers()
     {
-        if (!self::$instance) {
-            self::$instance = new self();
-        }
-
-        return self::$instance->helpersList();
-    }
-
-    /**
-     * A helper for string localization.
-     *
-     * Example of usage:
-     * <code>
-     *   {{l10n "localization.string" arg1 arg2 arg3}}
-     * </code>
-     * where:
-     *   - "localization.string" is localization constant.
-     *   - arg* are arguments that will be passed to getlocal2 function. There
-     *     can be arbitrary number of such arguments.
-     */
-    public function localizationHelper($template, $context, $args, $source)
-    {
-        // Check if there is at least one argument
-        $parsed_arguments = $template->parseArguments($args);
-        if (empty($parsed_arguments)) {
-            return '';
-        }
-
-        $text = $context->get(array_shift($parsed_arguments));
-
-        // We need to escape extra arguments passed to the helper. Thus we need
-        // to get escape function and its arguments from the template engine.
-        $escape_func = $template->getEngine()->getEscape();
-        $escape_args = $template->getEngine()->getEscapeArgs();
-
-        // Check if there are any other arguments passed into helper and escape
-        // them.
-        $local_args = array();
-        foreach ($parsed_arguments as $parsed_argument) {
-            // Get locale argument string and add it to escape function
-            // arguments.
-            array_unshift($escape_args, $context->get($parsed_argument));
-
-            // Escape locale argument's value
-            $local_args[] = call_user_func_array(
-                $escape_func,
-                array_values($escape_args)
+        if (!self::$helpers) {
+            $blocks = new BlockStorage();
+            self::$helpers = array(
+                'l10n' => (new Helper\L10nHelper()),
+                'extends' => (new Helper\ExtendsHelper()),
+                'block' => (new Helper\BlockHelper($blocks)),
+                'override' => (new Helper\OverrideHelper($blocks)),
+                'ifOverridden' => (new Helper\IfOverriddenHelper($blocks)),
+                'unlessOverridden' => (new Helper\UnlessOverriddenHelper($blocks)),
+                'ifEqual' => (new Helper\IfEqualHelper()),
+                'ifAny' => (new Helper\IfAnyHelper()),
+                'ifEven' => (new Helper\IfEvenHelper()),
+                'ifOdd' => (new Helper\IfOddHelper()),
+                'generatePagination' => (new Helper\GeneratePaginationHelper()),
+                'jsString' => (new Helper\JsStringHelper()),
+                'repeat' => (new Helper\RepeatHelper()),
+                'replace' => (new Helper\ReplaceHelper()),
+                'formatDate' => (new Helper\FormatDateHelper()),
+                'formatDateDiff' => (new Helper\FormatDateDiffHelper()),
+                'cutString' => (new Helper\CutStringHelper()),
+                'csrfTokenInput' => (new Helper\CsrfTokenInputHelper()),
+                'csrfTokenInUrl' => (new Helper\CsrfTokenInUrlHelper()),
             );
-
-            // Remove locale argument's value from escape function argument
-            array_shift($escape_args);
         }
 
-        $result = getlocal($text, $local_args);
-
-        return new \Handlebars\SafeString($result);
-    }
-
-    /**
-     * Conditional helper that checks if two values are equal or not.
-     *
-     * Example of usage:
-     * <code>
-     *   {{#ifEqual first second}}
-     *     The first argument is equal to the second one.
-     *   {{else}}
-     *     The arguments are not equal.
-     *   {{/ifEqual}}
-     * </code>
-     */
-    public function ifEqualHelper($template, $context, $args, $source)
-    {
-        $parsed_args = $template->parseArguments($args);
-        if (empty($parsed_args) || count($parsed_args) < 2) {
-            return '';
-        }
-
-        $condition = ($context->get($parsed_args[0]) == $context->get($parsed_args[1]));
-
-        if ($condition) {
-            $template->setStopToken('else');
-            $buffer = $template->render($context);
-            $template->setStopToken(false);
-        } else {
-            $template->setStopToken('else');
-            $template->discard();
-            $template->setStopToken(false);
-            $buffer = $template->render($context);
-        }
-
-        return $buffer;
-    }
-
-    /**
-     * Conditional helper that checks if specified argument is even or not.
-     *
-     * Example of usage:
-     * <code>
-     *   {{#ifEven value}}
-     *     The value is even.
-     *   {{else}}
-     *     The value is odd.
-     *   {{/ifEven}}
-     * </code>
-     */
-    public function ifEvenHelper($template, $context, $args, $source)
-    {
-        $parsed_args = $template->parseArguments($args);
-        if (empty($parsed_args)) {
-            return '';
-        }
-
-        $condition = ($context->get($parsed_args[0]) % 2 == 0);
-
-        if ($condition) {
-            $template->setStopToken('else');
-            $buffer = $template->render($context);
-            $template->setStopToken(false);
-        } else {
-            $template->setStopToken('else');
-            $template->discard();
-            $template->setStopToken(false);
-            $buffer = $template->render($context);
-        }
-
-        return $buffer;
-    }
-
-    /**
-     * Conditional helper that checks if specified argument is odd or not.
-     *
-     * Example of usage:
-     * <code>
-     *   {{#ifOdd value}}
-     *     The value is odd.
-     *   {{else}}
-     *     The value is even.
-     *   {{/ifOdd}}
-     * </code>
-     */
-    public function ifOddHelper($template, $context, $args, $source)
-    {
-        $parsed_args = $template->parseArguments($args);
-        if (empty($parsed_args)) {
-            return '';
-        }
-
-        $condition = ($context->get($parsed_args[0]) % 2 == 1);
-
-        if ($condition) {
-            $template->setStopToken('else');
-            $buffer = $template->render($context);
-            $template->setStopToken(false);
-        } else {
-            $template->setStopToken('else');
-            $template->discard();
-            $template->setStopToken(false);
-            $buffer = $template->render($context);
-        }
-
-        return $buffer;
-    }
-
-    /**
-     * Conditional helper that checks if at least one argumet can be treated as
-     * "true" value.
-     *
-     * Example of usage:
-     * <code>
-     *   {{#ifAny first second third}}
-     *     At least one of argument can be threated as "true".
-     *   {{else}}
-     *     All values are "falsy"
-     *   {{/ifAny}}
-     * </code>
-     */
-    public function ifAnyHelper($template, $context, $args, $source)
-    {
-        $parsed_args = $template->parseArguments($args);
-        if (empty($parsed_args)) {
-            return '';
-        }
-
-        $condition = false;
-        foreach ($parsed_args as $parsed_arg) {
-            $value = $context->get($parsed_arg);
-
-            if ($value instanceof \Handlebars\String) {
-                // We need to get internal string. Casting any object of
-                // \Handlebars\String will have positive result even for those
-                // with empty internal strings.
-                $value = $value->getString();
-            }
-
-            if ($value) {
-                $condition = true;
-                break;
-            }
-        }
-
-        if ($condition) {
-            $template->setStopToken('else');
-            $buffer = $template->render($context);
-            $template->setStopToken(false);
-        } else {
-            $template->setStopToken('else');
-            $template->discard();
-            $template->setStopToken(false);
-            $buffer = $template->render($context);
-        }
-
-        return $buffer;
-    }
-
-    /**
-     * A helper for templates inheritance.
-     *
-     * Example of usage:
-     * <code>
-     *   {{#extends "parentTemplateName"}}
-     *     {{#override "blockName"}}
-     *       Overridden first block
-     *     {{/override}}
-     *
-     *     {{#override "anotherBlockName"}}
-     *       Overridden second block
-     *     {{/override}}
-     *   {{/extends}}
-     * </code>
-     */
-    public function extendsHelper($template, $context, $args, $source)
-    {
-        // Get name of the parent template
-        $parsed_args = $template->parseArguments($args);
-        if (empty($parsed_args)) {
-            return '';
-        }
-        $parent_template = $context->get(array_shift($parsed_args));
-
-        // Render content inside "extends" block to override blocks
-        $template->render($context);
-
-        // We need to another instance of \Handlebars\Template to render parent
-        // template. It can be got from Handlebars engine, so get the latter.
-        $handlebars = $template->getEngine();
-
-        // Render the parent template
-        return $handlebars->render($parent_template, $context);
-    }
-
-    /**
-     * A helper for defining default content of a block.
-     *
-     * Example of usage:
-     * <code>
-     *   {{#block "blockName"}}
-     *     Default content for the block
-     *   {{/block}}
-     * </code>
-     */
-    public function blockHelper($template, $context, $args, $source)
-    {
-        // Get block name
-        $parsed_args = $template->parseArguments($args);
-        if (empty($parsed_args)) {
-            return '';
-        }
-        $block_name = $context->get(array_shift($parsed_args));
-
-        // If the block is not overridden render and show the default value
-        if (!isset($this->blocksStorage[$block_name])) {
-            return $template->render($context);
-        }
-
-        // Show overridden content
-        return $this->blocksStorage[$block_name];
-    }
-
-    /**
-     * A helper for overriding content of a block.
-     *
-     * Example of usage:
-     * <code>
-     *   {{#extends "parentTemplateName"}}
-     *     {{#override "blockName"}}
-     *       Overridden first block
-     *     {{/override}}
-     *
-     *     {{#override "anotherBlockName"}}
-     *       Overridden second block
-     *     {{/override}}
-     *   {{/extends}}
-     * </code>
-     */
-    public function overrideHelper($template, $context, $args, $source)
-    {
-        // Get block name
-        $parsed_args = $template->parseArguments($args);
-        if (empty($parsed_args)) {
-            return '';
-        }
-        $block_name = $context->get(array_shift($parsed_args));
-
-        // We need to provide unlimited inheritence level. Rendering is started
-        // from the deepest level template. If the content is in the block
-        // storage it is related with the deepest level template. Thus we do not
-        // need to override it.
-        if (!isset($this->blocksStorage[$block_name])) {
-            $this->blocksStorage[$block_name] = $template->render($context);
-        }
-    }
-
-    /**
-     * Conditional helper that checks if block overridden or not.
-     *
-     * Example of usage:
-     * <code>
-     *   {{#ifOverridden "blockName"}}
-     *     The block was overridden
-     *   {{else}}
-     *     The block was not overridden
-     *   {{/ifOverriden}}
-     * </code>
-     */
-    public function ifOverriddenHelper($template, $context, $args, $source)
-    {
-        // Get block name
-        $parsed_args = $template->parseArguments($args);
-        if (empty($parsed_args)) {
-            return '';
-        }
-        $block_name = $context->get(array_shift($parsed_args));
-
-        // Check condition and render blocks
-        if (isset($this->blocksStorage[$block_name])) {
-            $template->setStopToken('else');
-            $buffer = $template->render($context);
-            $template->setStopToken(false);
-        } else {
-            $template->setStopToken('else');
-            $template->discard();
-            $template->setStopToken(false);
-            $buffer = $template->render($context);
-        }
-
-        return $buffer;
-    }
-
-    /**
-     * Conditional helper that checks if block overridden or not.
-     *
-     * Example of usage:
-     * <code>
-     *   {{#unlessOverridden "blockName"}}
-     *     The block was not overridden
-     *   {{else}}
-     *     The block was overridden
-     *   {{/unlessOverriden}}
-     * </code>
-     */
-    public function unlessOverriddenHelper($template, $context, $args, $source)
-    {
-        // Get block name
-        $parsed_args = $template->parseArguments($args);
-        if (empty($parsed_args)) {
-            return '';
-        }
-        $block_name = $context->get(array_shift($parsed_args));
-
-        // Check condition and render blocks
-        if (!isset($this->blocksStorage[$block_name])) {
-            $template->setStopToken('else');
-            $buffer = $template->render($context);
-            $template->setStopToken(false);
-        } else {
-            $template->setStopToken('else');
-            $template->discard();
-            $template->setStopToken(false);
-            $buffer = $template->render($context);
-        }
-
-        return $buffer;
-    }
-
-    /**
-     * Generates markup with hidden input tag for CSRF token.
-     *
-     * Example of usage:
-     * <code>
-     *   {{csrfTokenInput}}
-     * </code>
-     */
-    public function csrfTokenInputHelper()
-    {
-        return new \Handlebars\SafeString(get_csrf_token_input());
-    }
-
-    /**
-     * Generates CSRF taken formated prepared to insert in URLs.
-     *
-     * Example of usage:
-     * <code>
-     *   {{csrfTokenInUrl}}
-     * </code>
-     */
-    public function csrfTokenInUrlHelper()
-    {
-        return new \Handlebars\SafeString(get_csrf_token_in_url());
-    }
-
-    /**
-     * Generates pagination block.
-     *
-     * Example of usage:
-     * <code>
-     *   {{generatePagination stylePath paginationInfo bottom}}
-     * </code>
-     * where:
-     *   - "stylePath" is expression for path to current style.
-     *   - "paginationInfo" is 'info' key from the result of setup_pagination
-     *     function.
-     *   - "bottom": optional argument that indicate if pagination block shoud
-     *     be generated for a page bottom or not. If specified and equal to
-     *     string "false" then boolean false will be passed into
-     *     generate_pagination. In all other cases boolean true will be used.
-     */
-    public function generatePaginationHelper($template, $context, $args, $source)
-    {
-        $parsed_args = $template->parseArguments($args);
-        if (empty($parsed_args) || count($parsed_args) < 2) {
-            return '';
-        }
-
-        $stylePath = $context->get($parsed_args[0]);
-        $pagination_info = $context->get($parsed_args[1]);
-        $bottom = empty($parsed_args[2]) ? true : $context->get($parsed_args[2]);
-
-        $pagination = generate_pagination(
-            $stylePath,
-            $pagination_info,
-            ($bottom === "false") ? false : true
-        );
-
-        return new \Handlebars\SafeString($pagination);
-    }
-
-    /**
-     * Escapes special characters to use result as a valid JavaScript string
-     * enclosed with single quotes (') or duouble quotes (").
-     *
-     * Example of usage:
-     * <code>
-     *   var a = "{{#jsString}}some string to escape{{/jsString}}";
-     * </code>
-     */
-    public function jsStringHelper($template, $context, $args, $source)
-    {
-        return str_replace("\n", "\\n", addslashes($template->render($context)));
-    }
-
-    /**
-     * Helper for repeating content.
-     *
-     * Example of usage:
-     * <code>
-     *   {{#repeat times}}content to repeat{{/repeat}}
-     * </code>
-     */
-    public function repeatHelper($template, $context, $args, $source)
-    {
-        $parsed_args = $template->parseArguments($args);
-        if (empty($parsed_args)) {
-            return '';
-        }
-
-        $times = intval($context->get($parsed_args[0]));
-        $string = $template->render($context);
-
-        return str_repeat($string, $times);
-    }
-
-    /**
-     * Helper for replacing substrings.
-     *
-     * Example of usage:
-     * <code>
-     *   {{#replace search replacement}}target content{{/replace}}
-     * </code>
-     */
-    public function replaceHelper($template, $context, $args, $source)
-    {
-        $parsed_args = $template->parseArguments($args);
-        if (empty($parsed_args) || count($parsed_args) < 2) {
-            return '';
-        }
-
-        $search = $context->get($parsed_args[0]);
-        $replacement = $context->get($parsed_args[1]);
-        $subject = $template->render($context);
-
-        return str_replace($search, $replacement, $subject);
-    }
-
-    /**
-     * Format date using internal format.
-     *
-     * Example of usage:
-     * <code>
-     *   {{formatDate unixTimestamp}}
-     * </code>
-     */
-    public function formatDateHelper($template, $context, $args, $source)
-    {
-        $parsed_args = $template->parseArguments($args);
-        if (empty($parsed_args)) {
-            return '';
-        }
-
-        $timestamp = intval($context->get($parsed_args[0]));
-
-        return date_to_text($timestamp);
-    }
-
-    /**
-     * Format date difference using internal format.
-     *
-     * Example of usage:
-     * <code>
-     *   {{formatDateDiff seconds}}
-     * </code>
-     */
-    public function formatDateDiffHelper($template, $context, $args, $source)
-    {
-        $parsed_args = $template->parseArguments($args);
-        if (empty($parsed_args)) {
-            return '';
-        }
-
-        $seconds = intval($context->get($parsed_args[0]));
-
-        return date_diff_to_text($seconds);
-    }
-
-    /**
-     * Cut string if it exceeds specified length.
-     *
-     * Example of usage:
-     * <code>
-     *   {{cutString string length}}
-     * </code>
-     */
-    public function cutStringHelper($template, $context, $args, $source)
-    {
-        $parsed_args = $template->parseArguments($args);
-        if (empty($parsed_args) || count($parsed_args) < 2) {
-            return '';
-        }
-
-        $string = $context->get($parsed_args[0]);
-        $length = intval($context->get($parsed_args[1]));
-
-        return substr($string, 0, $length);
-    }
-
-    /**
-     * Actually builds helpers list.
-     *
-     * @return array List of helpers
-     */
-    protected function helpersList()
-    {
-        return array(
-            'l10n' => array($this, 'localizationHelper'),
-            'extends' => array($this, 'extendsHelper'),
-            'block' => array($this, 'blockHelper'),
-            'override' => array($this, 'overrideHelper'),
-            'ifOverridden' => array($this, 'ifOverriddenHelper'),
-            'unlessOverridden' => array($this, 'unlessOverriddenHelper'),
-            'ifEqual' => array($this, 'ifEqualHelper'),
-            'ifAny' => array($this, 'ifAnyHelper'),
-            'ifEven' => array($this, 'ifEvenHelper'),
-            'ifOdd' => array($this, 'ifOddHelper'),
-            'generatePagination' => array($this, 'generatePaginationHelper'),
-            'jsString' => array($this, 'jsStringHelper'),
-            'repeat' => array($this, 'repeatHelper'),
-            'replace' => array($this, 'replaceHelper'),
-            'formatDate' => array($this, 'formatDateHelper'),
-            'formatDateDiff' => array($this, 'formatDateDiffHelper'),
-            'cutString' => array($this, 'cutStringHelper'),
-            'csrfTokenInput' => array($this, 'csrfTokenInputHelper'),
-            'csrfTokenInUrl' => array($this, 'csrfTokenInUrlHelper'),
-        );
+        return self::$helpers;
     }
 }