framework/base/View.php
<?php
/**
* @link https://www.yiiframework.com/
* @copyright Copyright (c) 2008 Yii Software LLC
* @license https://www.yiiframework.com/license/
*/
namespace yii\base;
use Yii;
use yii\helpers\FileHelper;
use yii\widgets\Block;
use yii\widgets\ContentDecorator;
use yii\widgets\FragmentCache;
/**
* View represents a view object in the MVC pattern.
*
* View provides a set of methods (e.g. [[render()]]) for rendering purpose.
*
* For more details and usage information on View, see the [guide article on views](guide:structure-views).
*
* @property-read string|bool $viewFile The view file currently being rendered. False if no view file is being
* rendered.
*
* @author Qiang Xue <qiang.xue@gmail.com>
* @since 2.0
*/
class View extends Component implements DynamicContentAwareInterface
{
/**
* @event Event an event that is triggered by [[beginPage()]].
*/
const EVENT_BEGIN_PAGE = 'beginPage';
/**
* @event Event an event that is triggered by [[endPage()]].
*/
const EVENT_END_PAGE = 'endPage';
/**
* @event ViewEvent an event that is triggered by [[renderFile()]] right before it renders a view file.
*/
const EVENT_BEFORE_RENDER = 'beforeRender';
/**
* @event ViewEvent an event that is triggered by [[renderFile()]] right after it renders a view file.
*/
const EVENT_AFTER_RENDER = 'afterRender';
/**
* @var ViewContextInterface the context under which the [[renderFile()]] method is being invoked.
*/
public $context;
/**
* @var array custom parameters that are shared among view templates.
*/
public $params = [];
/**
* @var array|null a list of available renderers indexed by their corresponding supported file extensions.
* Each renderer may be a view renderer object or the configuration for creating the renderer object.
* For example, the following configuration enables both Smarty and Twig view renderers:
*
* ```php
* [
* 'tpl' => ['class' => 'yii\smarty\ViewRenderer'],
* 'twig' => ['class' => 'yii\twig\ViewRenderer'],
* ]
* ```
*
* If no renderer is available for the given view file, the view file will be treated as a normal PHP
* and rendered via [[renderPhpFile()]].
*/
public $renderers;
/**
* @var string the default view file extension. This will be appended to view file names if they don't have file extensions.
*/
public $defaultExtension = 'php';
/**
* @var Theme|array|string|null the theme object or the configuration for creating the theme object.
* If not set, it means theming is not enabled.
*/
public $theme;
/**
* @var array a list of named output blocks. The keys are the block names and the values
* are the corresponding block content. You can call [[beginBlock()]] and [[endBlock()]]
* to capture small fragments of a view. They can be later accessed somewhere else
* through this property.
*/
public $blocks;
/**
* @var array|DynamicContentAwareInterface[] a list of currently active dynamic content class instances.
* This property is used internally to implement the dynamic content caching feature. Do not modify it directly.
* @internal
* @deprecated Since 2.0.14. Do not use this property directly. Use methods [[getDynamicContents()]],
* [[pushDynamicContent()]], [[popDynamicContent()]] instead.
*/
public $cacheStack = [];
/**
* @var array a list of placeholders for embedding dynamic contents. This property
* is used internally to implement the content caching feature. Do not modify it directly.
* @internal
* @deprecated Since 2.0.14. Do not use this property directly. Use methods [[getDynamicPlaceholders()]],
* [[setDynamicPlaceholders()]], [[addDynamicPlaceholder()]] instead.
*/
public $dynamicPlaceholders = [];
/**
* @var array the view files currently being rendered. There may be multiple view files being
* rendered at a moment because one view may be rendered within another.
*/
private $_viewFiles = [];
/**
* Initializes the view component.
*/
public function init()
{
parent::init();
if (is_array($this->theme)) {
if (!isset($this->theme['class'])) {
$this->theme['class'] = 'yii\base\Theme';
}
$this->theme = Yii::createObject($this->theme);
} elseif (is_string($this->theme)) {
$this->theme = Yii::createObject($this->theme);
}
}
/**
* Renders a view.
*
* The view to be rendered can be specified in one of the following formats:
*
* - [path alias](guide:concept-aliases) (e.g. "@app/views/site/index");
* - absolute path within application (e.g. "//site/index"): the view name starts with double slashes.
* The actual view file will be looked for under the [[Application::viewPath|view path]] of the application.
* - absolute path within current module (e.g. "/site/index"): the view name starts with a single slash.
* The actual view file will be looked for under the [[Module::viewPath|view path]] of the [[Controller::module|current module]].
* - relative view (e.g. "index"): the view name does not start with `@` or `/`. The corresponding view file will be
* looked for under the [[ViewContextInterface::getViewPath()|view path]] of the view `$context`.
* If `$context` is not given, it will be looked for under the directory containing the view currently
* being rendered (i.e., this happens when rendering a view within another view).
*
* @param string $view the view name.
* @param array $params the parameters (name-value pairs) that will be extracted and made available in the view file.
* @param object|null $context the context to be assigned to the view and can later be accessed via [[context]]
* in the view. If the context implements [[ViewContextInterface]], it may also be used to locate
* the view file corresponding to a relative view name.
* @return string the rendering result
* @throws ViewNotFoundException if the view file does not exist.
* @throws InvalidCallException if the view cannot be resolved.
* @see renderFile()
*/
public function render($view, $params = [], $context = null)
{
$viewFile = $this->findViewFile($view, $context);
return $this->renderFile($viewFile, $params, $context);
}
/**
* Finds the view file based on the given view name.
* @param string $view the view name or the [path alias](guide:concept-aliases) of the view file. Please refer to [[render()]]
* on how to specify this parameter.
* @param object|null $context the context to be assigned to the view and can later be accessed via [[context]]
* in the view. If the context implements [[ViewContextInterface]], it may also be used to locate
* the view file corresponding to a relative view name.
* @return string the view file path. Note that the file may not exist.
* @throws InvalidCallException if a relative view name is given while there is no active context to
* determine the corresponding view file.
*/
protected function findViewFile($view, $context = null)
{
if (strncmp($view, '@', 1) === 0) {
// e.g. "@app/views/main"
$file = Yii::getAlias($view);
} elseif (strncmp($view, '//', 2) === 0) {
// e.g. "//layouts/main"
$file = Yii::$app->getViewPath() . DIRECTORY_SEPARATOR . ltrim($view, '/');
} elseif (strncmp($view, '/', 1) === 0) {
// e.g. "/site/index"
if (Yii::$app->controller !== null) {
$file = Yii::$app->controller->module->getViewPath() . DIRECTORY_SEPARATOR . ltrim($view, '/');
} else {
throw new InvalidCallException("Unable to locate view file for view '$view': no active controller.");
}
} elseif ($context instanceof ViewContextInterface) {
$file = $context->getViewPath() . DIRECTORY_SEPARATOR . $view;
} elseif (($currentViewFile = $this->getRequestedViewFile()) !== false) {
$file = dirname($currentViewFile) . DIRECTORY_SEPARATOR . $view;
} else {
throw new InvalidCallException("Unable to resolve view file for view '$view': no active view context.");
}
if (pathinfo($file, PATHINFO_EXTENSION) !== '') {
return $file;
}
$path = $file . '.' . $this->defaultExtension;
if ($this->defaultExtension !== 'php' && !is_file($path)) {
$path = $file . '.php';
}
return $path;
}
/**
* Renders a view file.
*
* If [[theme]] is enabled (not null), it will try to render the themed version of the view file as long
* as it is available.
*
* The method will call [[FileHelper::localize()]] to localize the view file.
*
* If [[renderers|renderer]] is enabled (not null), the method will use it to render the view file.
* Otherwise, it will simply include the view file as a normal PHP file, capture its output and
* return it as a string.
*
* @param string $viewFile the view file. This can be either an absolute file path or an alias of it.
* @param array $params the parameters (name-value pairs) that will be extracted and made available in the view file.
* @param object|null $context the context that the view should use for rendering the view. If null,
* existing [[context]] will be used.
* @return string the rendering result
* @throws ViewNotFoundException if the view file does not exist
*/
public function renderFile($viewFile, $params = [], $context = null)
{
$viewFile = $requestedFile = Yii::getAlias($viewFile);
if ($this->theme !== null) {
$viewFile = $this->theme->applyTo($viewFile);
}
if (is_file($viewFile)) {
$viewFile = FileHelper::localize($viewFile);
} else {
throw new ViewNotFoundException("The view file does not exist: $viewFile");
}
$oldContext = $this->context;
if ($context !== null) {
$this->context = $context;
}
$output = '';
$this->_viewFiles[] = [
'resolved' => $viewFile,
'requested' => $requestedFile
];
if ($this->beforeRender($viewFile, $params)) {
Yii::debug("Rendering view file: $viewFile", __METHOD__);
$ext = pathinfo($viewFile, PATHINFO_EXTENSION);
if (isset($this->renderers[$ext])) {
if (is_array($this->renderers[$ext]) || is_string($this->renderers[$ext])) {
$this->renderers[$ext] = Yii::createObject($this->renderers[$ext]);
}
/* @var $renderer ViewRenderer */
$renderer = $this->renderers[$ext];
$output = $renderer->render($this, $viewFile, $params);
} else {
$output = $this->renderPhpFile($viewFile, $params);
}
$this->afterRender($viewFile, $params, $output);
}
array_pop($this->_viewFiles);
$this->context = $oldContext;
return $output;
}
/**
* @return string|bool the view file currently being rendered. False if no view file is being rendered.
*/
public function getViewFile()
{
return empty($this->_viewFiles) ? false : end($this->_viewFiles)['resolved'];
}
/**
* @return string|bool the requested view currently being rendered. False if no view file is being rendered.
* @since 2.0.16
*/
protected function getRequestedViewFile()
{
return empty($this->_viewFiles) ? false : end($this->_viewFiles)['requested'];
}
/**
* This method is invoked right before [[renderFile()]] renders a view file.
* The default implementation will trigger the [[EVENT_BEFORE_RENDER]] event.
* If you override this method, make sure you call the parent implementation first.
* @param string $viewFile the view file to be rendered.
* @param array $params the parameter array passed to the [[render()]] method.
* @return bool whether to continue rendering the view file.
*/
public function beforeRender($viewFile, $params)
{
$event = new ViewEvent([
'viewFile' => $viewFile,
'params' => $params,
]);
$this->trigger(self::EVENT_BEFORE_RENDER, $event);
return $event->isValid;
}
/**
* This method is invoked right after [[renderFile()]] renders a view file.
* The default implementation will trigger the [[EVENT_AFTER_RENDER]] event.
* If you override this method, make sure you call the parent implementation first.
* @param string $viewFile the view file being rendered.
* @param array $params the parameter array passed to the [[render()]] method.
* @param string $output the rendering result of the view file. Updates to this parameter
* will be passed back and returned by [[renderFile()]].
*/
public function afterRender($viewFile, $params, &$output)
{
if ($this->hasEventHandlers(self::EVENT_AFTER_RENDER)) {
$event = new ViewEvent([
'viewFile' => $viewFile,
'params' => $params,
]);
$event->output =& $output;
$this->trigger(self::EVENT_AFTER_RENDER, $event);
}
}
/**
* Renders a view file as a PHP script.
*
* This method treats the view file as a PHP script and includes the file.
* It extracts the given parameters and makes them available in the view file.
* The method captures the output of the included view file and returns it as a string.
*
* This method should mainly be called by view renderer or [[renderFile()]].
*
* @param string $_file_ the view file.
* @param array $_params_ the parameters (name-value pairs) that will be extracted and made available in the view file.
* @return string the rendering result
* @throws \Throwable
*/
public function renderPhpFile($_file_, $_params_ = [])
{
$_obInitialLevel_ = ob_get_level();
ob_start();
ob_implicit_flush(false);
extract($_params_, EXTR_OVERWRITE);
try {
require $_file_;
return ob_get_clean();
} catch (\Exception $e) {
while (ob_get_level() > $_obInitialLevel_) {
if (!@ob_end_clean()) {
ob_clean();
}
}
throw $e;
} catch (\Throwable $e) {
while (ob_get_level() > $_obInitialLevel_) {
if (!@ob_end_clean()) {
ob_clean();
}
}
throw $e;
}
}
/**
* Renders dynamic content returned by the given PHP statements.
* This method is mainly used together with content caching (fragment caching and page caching)
* when some portions of the content (called *dynamic content*) should not be cached.
* The dynamic content must be returned by some PHP statements.
* @param string $statements the PHP statements for generating the dynamic content.
* @return string the placeholder of the dynamic content, or the dynamic content if there is no
* active content cache currently.
*
* Note that most methods that indirectly modify layout such as registerJS() or registerJSFile() do not
* work with dynamic rendering.
*
* @see https://github.com/yiisoft/yii2/issues/17673
*/
public function renderDynamic($statements)
{
if (!empty($this->cacheStack)) {
$n = count($this->dynamicPlaceholders);
$placeholder = "<![CDATA[YII-DYNAMIC-$n]]>";
$this->addDynamicPlaceholder($placeholder, $statements);
return $placeholder;
}
return $this->evaluateDynamicContent($statements);
}
/**
* {@inheritdoc}
*/
public function getDynamicPlaceholders()
{
return $this->dynamicPlaceholders;
}
/**
* {@inheritdoc}
*/
public function setDynamicPlaceholders($placeholders)
{
$this->dynamicPlaceholders = $placeholders;
}
/**
* {@inheritdoc}
*/
public function addDynamicPlaceholder($placeholder, $statements)
{
foreach ($this->cacheStack as $cache) {
if ($cache instanceof DynamicContentAwareInterface) {
$cache->addDynamicPlaceholder($placeholder, $statements);
} else {
// TODO: Remove in 2.1
$cache->dynamicPlaceholders[$placeholder] = $statements;
}
}
$this->dynamicPlaceholders[$placeholder] = $statements;
}
/**
* Evaluates the given PHP statements.
* This method is mainly used internally to implement dynamic content feature.
* @param string $statements the PHP statements to be evaluated.
* @return mixed the return value of the PHP statements.
*/
public function evaluateDynamicContent($statements)
{
return eval($statements);
}
/**
* Returns a list of currently active dynamic content class instances.
* @return DynamicContentAwareInterface[] class instances supporting dynamic contents.
* @since 2.0.14
*/
public function getDynamicContents()
{
return $this->cacheStack;
}
/**
* Adds a class instance supporting dynamic contents to the end of a list of currently active
* dynamic content class instances.
* @param DynamicContentAwareInterface $instance class instance supporting dynamic contents.
* @since 2.0.14
*/
public function pushDynamicContent(DynamicContentAwareInterface $instance)
{
$this->cacheStack[] = $instance;
}
/**
* Removes a last class instance supporting dynamic contents from a list of currently active
* dynamic content class instances.
* @since 2.0.14
*/
public function popDynamicContent()
{
array_pop($this->cacheStack);
}
/**
* Begins recording a block.
*
* This method is a shortcut to beginning [[Block]].
* @param string $id the block ID.
* @param bool $renderInPlace whether to render the block content in place.
* Defaults to false, meaning the captured block will not be displayed.
* @return Block the Block widget instance
*/
public function beginBlock($id, $renderInPlace = false)
{
return Block::begin([
'id' => $id,
'renderInPlace' => $renderInPlace,
'view' => $this,
]);
}
/**
* Ends recording a block.
*/
public function endBlock()
{
Block::end();
}
/**
* Begins the rendering of content that is to be decorated by the specified view.
*
* This method can be used to implement nested layout. For example, a layout can be embedded
* in another layout file specified as '@app/views/layouts/base.php' like the following:
*
* ```php
* <?php $this->beginContent('@app/views/layouts/base.php'); ?>
* //...layout content here...
* <?php $this->endContent(); ?>
* ```
*
* @param string $viewFile the view file that will be used to decorate the content enclosed by this widget.
* This can be specified as either the view file path or [path alias](guide:concept-aliases).
* @param array $params the variables (name => value) to be extracted and made available in the decorative view.
* @return ContentDecorator the ContentDecorator widget instance
* @see ContentDecorator
*/
public function beginContent($viewFile, $params = [])
{
return ContentDecorator::begin([
'viewFile' => $viewFile,
'params' => $params,
'view' => $this,
]);
}
/**
* Ends the rendering of content.
*/
public function endContent()
{
ContentDecorator::end();
}
/**
* Begins fragment caching.
*
* This method will display cached content if it is available.
* If not, it will start caching and would expect an [[endCache()]]
* call to end the cache and save the content into cache.
* A typical usage of fragment caching is as follows,
*
* ```php
* if ($this->beginCache($id)) {
* // ...generate content here
* $this->endCache();
* }
* ```
*
* @param string $id a unique ID identifying the fragment to be cached.
* @param array $properties initial property values for [[FragmentCache]]
* @return bool whether you should generate the content for caching.
* False if the cached version is available.
*/
public function beginCache($id, $properties = [])
{
$properties['id'] = $id;
$properties['view'] = $this;
/* @var $cache FragmentCache */
$cache = FragmentCache::begin($properties);
if ($cache->getCachedContent() !== false) {
$this->endCache();
return false;
}
return true;
}
/**
* Ends fragment caching.
*/
public function endCache()
{
FragmentCache::end();
}
/**
* Marks the beginning of a page.
*/
public function beginPage()
{
ob_start();
ob_implicit_flush(false);
$this->trigger(self::EVENT_BEGIN_PAGE);
}
/**
* Marks the ending of a page.
*/
public function endPage()
{
$this->trigger(self::EVENT_END_PAGE);
ob_end_flush();
}
}