Idea discussion: dynamic view script switching in zend MVC implementation [closed] - zend-framework

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Closed 11 years ago.
This is basically the "Am i doing it right?" question.
I have an idea how i can transparently switch views for default/mobile version/admin areas at run time. And I would like to know what pros and cons you see in this approach.
Main requirements are:
switch entire application with
little to no coding
integrate into zend MVC workflow,
not overwrite it
fallback to default
preserve standard functionality
controllers shouldn't be aware of
changes
Here is my pseudohelper
class Xrks_Controller_Action_Helper_VrExtension extends Zend_Controller_Action_Helper_Abstract
{
public function postDispatch()
{
if(!$this->_shouldRender()) {
return; //just skip
}
try {
$vr = $this->_getViewRenderer();
$backupView = clone $vr->view;
$this->_setBasePaths(); //set base path(s) through ViewRenderer::initView($path)
$oldSpecArray = $this->_setVrPathSpecs(); //set VR view script path specs
$vr->render();
$vr->setNoRender(true); //disable renderer
} catch(Zend_View_Exception $e) { //fallback to default viewscripts if view script file not found
$vr->setView($backupView); //restore view on error
} catch(Exception $e) {
$vr->setView($backupView); //restore view on error
$this->_setVrPathSpecs($oldSpecArray); //restore script path spec
throw $e;
}
$this->_setVrPathSpecs($oldSpecArray);//restore script path spec
}
/**
* Same functionality as ViewRenderer helper _shouldRender method
* #return boolean
*/
protected function _shouldRender();
/**
* #return Zend_Controller_Action_Helper_ViewRenderer
*/
protected function _getViewRenderer();
/**
* Sets viewRenderer path specifications
*
* #param array $spec if NULL uses $this->_viewRendererPathSpecs
* #return array old path spec (0 => pathSpec, 1 => pathNoControllerSpec)
*/
protected function _setVrPathSpecs(array $spec = NULL);
}
How exactly helper should be configured is not important and that part skipped
Here is example how it supposed to work:
$this->_setBasePaths(); sets view base paths to application/views/default/ and application/views/admin/
$this->_setVrPathSpecs(); set path specification to ':module/:controller/:action.:suffix'
so for foo-baz-bar it will search at
1. application/views/admin/scripts/foo/baz/bar.phtml
2. application/views/default/scripts/foo/baz/bar.phtml
if view script not found fall back to default ViewRenderer:
3. application/modules/foo/views/scripts/baz/bar.phtml
Ask questions if I missed something
Upd: After some research i decided to use action helper to autoregister view scriptPaths based on specification for inflector and specified variables. I also modified partial helpers to register scriptPaths if partial from other module requested.
This is crude but working version of action helper:
class Xrks_Controller_Action_Helper_ViewRendererPathstack extends Zend_Controller_Action_Helper_Abstract
{
const PATH_APPEND = 'append';
const PATH_PREPEND = 'prepend';
protected $_enabled = FALSE;
protected $_viewScriptPaths = array();
/**
* By default following vars available: baseDir, area, theme, module
* #var string
*/
protected $_viewScriptPathSpec = ':baseDir/:area/:module';
protected $_defaults = array(
'area' => 'frontend',
'theme' => 'default',
);
protected $_vars = array();
protected $_inflector;
protected $_viewRenderer;
public function __construct($baseDir = NULL)
{
if($baseDir == NULL) {
$baseDir = APPLICATION_PATH . DS . 'views';
}
$this->setDefaultVar('baseDir', $baseDir);
$this->addPath(array());
}
/**
* Enter description here ...
* #return Zend_Controller_Action_Helper_ViewRenderer
*/
protected function _getViewRenderer()
{
if(!$this->_viewRenderer) {
$this->_viewRenderer = Zend_Controller_Action_HelperBroker::getStaticHelper('viewRenderer');
}
return $this->_viewRenderer;
}
/**
* Should the ViewRenderer render a view script?
*
* #return boolean
*/
protected function _shouldRender()
{
$vR = $this->_getViewRenderer();
return (!$this->getFrontController()->getParam('noViewRenderer')
&& !$vR->getNeverRender()
&& !$vR->getNoRender()
&& (null !== $vR->getActionController())
&& $vR->getRequest()->isDispatched()
&& !$vR->getResponse()->isRedirect()
);
}
public function generatePaths(array $vars = array())
{
$this->_registerVarsWithInflector();
$vars = array_merge($this->_defaults, $this->_vars, $vars);
$inflector = $this->getInflector();
$generatedPaths = array();
foreach($this->_viewScriptPaths as $path) {
$pathVars = array_merge($vars, $path);
$generatedPaths[] = $inflector->filter($pathVars);
}
return array_reverse(array_unique(array_reverse($generatedPaths)));//last occurence more important than first
// array('test', 'test2', 'test') => array('test2', 'test')
// #todo rethink this code piece later. must be better solution
}
protected function _registerVarsWithInflector()
{
$vars = array_merge($this->_defaults, $this->_vars);
$inflector = $this->getInflector();
$unregistered = array_keys(array_diff_key($vars, $inflector->getRules()));
sort($unregistered, SORT_DESC);//more specific first (moduleDir prior to module key)
foreach($unregistered as $var) {
$inflector->addFilterRule($var, array('Word_CamelCaseToDash', 'StringToLower'));
}
}
protected function _viewAddScriptPaths(Zend_View_Abstract $view, $paths)
{
foreach ($paths as $path) {
$view->addScriptPath($path);
}
}
/**
* Get inflector
*
* #return Zend_Filter_Inflector
*/
public function getInflector()
{
if (null === $this->_inflector) {
$this->_inflector = new Zend_Filter_Inflector();
$this->_inflector->setThrowTargetExceptionsOn(true);
//setup default rules
$this->_inflector->addRules(array(
':baseDir' => array(),
))
->setTargetReference($this->_viewScriptPathSpec);
}
return $this->_inflector;
}
/**
*
* #return array
*/
public function getPaths()
{
return $this->_basePaths;
}
public function getEnabled()
{
return $this->_enabled;
}
public function setEnabled($flag = TRUE)
{
$this->_enabled = (bool)$flag;
return $this;
}
/**
*
* #todo add check for $pathVars keys and values validity
* #param array $pathVars associative array
* #param string $placement either append or prepend
* #return Xrks_Controller_Action_Helper_ViewRendererPathstack
*/
public function addPath(array $pathVars, $placement = self::PATH_APPEND)
{
if($placement == self::PATH_PREPEND) {
array_unshift($this->_viewScriptPaths, $pathVars);
} else {
$this->_viewScriptPaths[] = $pathVars;
}
return $this;
}
/**
*
* #param array|Zend_Config $paths
* #param string $placement either append or prepend
* #return Xrks_Controller_Action_Helper_ViewRendererPathstack
* #throws Xrks_Exception
*/
public function addPaths($paths, $placement = self::PATH_APPEND)
{
if($paths instanceof Zend_Config) {
$paths = $paths->toArray();
} elseif (!is_array($paths)) {
throw new Xrks_Exception('$paths should be either array or instance of Zend_Config');
}
if($placement == self::PATH_PREPEND) {
$paths = array_reverse($paths);
}
foreach($paths as $path) {
$this->addPath((array)$path, $placement);
}
return $this;
}
/**
*
* #param array $pathVars associative array
* #return Xrks_Controller_Action_Helper_ViewRendererPathstack
*/
public function setPath(array $pathVars)
{
$this->_basePaths = array();
$this->addPath($pathVars);
return $this;
}
/**
*
* #param array|Zend_Config $paths
* #return Xrks_Controller_Action_Helper_ViewRendererPathstack
* #throws Xrks_Exception
*/
public function setPaths($paths)
{
$this->_basePaths = array();
$this->addPaths($paths);
return $this;
}
/**
*
* #param string $varName
* #return string |NULL
*/
public function getDefaultVar($varName)
{
if(key_exists($varName, $this->_defaults)) {
return $this->_defaults[$varName];
}
return NULL;
}
/**
* #param string $varName
* #param string $value
* #return Xrks_Controller_Action_Helper_ViewRendererPathstack Provides fluent interface
*/
public function setDefaultVar($varName, $value)
{
$this->_defaults[$varName] = (string)$value;
return $this;
}
/**
*
* #param string $name
* #return string |NULL
*/
public function getVar($name, $defaults = false)
{
if(key_exists($name, $this->_vars)) {
return $this->_vars[$name];
}
return $defaults ? $this->getDefaultVar($name) : NULL;
}
/**
* #param string $varName
* #param string $value
* #return Xrks_Controller_Action_Helper_ViewRendererPathstack Provides fluent interface
*/
public function setVar($varName, $value)
{
$this->_vars[$varName] = $value;
return $this;
}
public function unsetVar($name)
{
if(key_exists($name, $this->_vars)) {
unset($this->_vars[$name]);
}
return $this;
}
public function postDispatch()
{
if(!$this->getEnabled() || !$this->_shouldRender()) {
return; //just skip
}
try {
$vr = $this->_getViewRenderer();
$this->setVar('module', $vr->getModule());
$paths = $this->generatePaths();
$this->_viewAddScriptPaths($vr->view, $paths);
if(Zend_Registry::isRegistered('Zend_Log')) {
Zend_Registry::get('Zend_Log')
->log($paths, Zend_Log::DEBUG);
}
} catch(Exception $e) {
if(Zend_Registry::isRegistered('Zend_Log')) {
Zend_Registry::get('Zend_Log')
->log($e, Zend_Log::WARN);
}
throw $e;
}
}
}

Answer 1

The way I usually handle this:
I register a Layout Plugin, extending Zend_Layout_Controller_Plugin_Layout
I use the preDispatch hook to determine what module, controller, action I am in
I switch between layouts and views depending on the context
For me, that's by far the easiest method.
GJ