Yii renderpartial (proccessoutput = true) Avoid Duplicate js request

Question

Im creating a site who works with ajaxRequest, when I click a link, it will load using ajaxRequest. When I load for example user/login UserController actionLogin, I renderPartial the view with processOUtput to true so the js needed inside that view will be generated, however if I have clientScriptRegister inside that view with events, how can I avoid to generate the scriptRegistered twice or multiple depending on the ajaxRequest? I have tried Yii::app()->clientScript->isSCriptRegistered('scriptId') to check if the script is already registered but it seems that if you used ajaxRequest, the result is always false because it will only be true after the render is finished.

Controller code

if (Yii::app()->request->isAjaxRequest)
{
   $this->renderPartial('view',array('model'=>$model),false,true);
}

View Code

if (!Yii::app()->clientScript->isScriptregistered("view-script"))
   Yii::app()->clientScript->registerScript("view-script","
      $('.link').live('click',function(){
         alert('test');
     })
");

If I request for the controller for the first time, it works perfectly (alert 1 time) but if I request again for that same controller without refreshing my page and just using ajaxRequest, the alert will output twice if you click it (because it keeps on generating eventhough you already registered it once)

This is the same if you have CActiveForm inside the view with jquery functionality.. the corescript yiiactiveform will be called everytime you renderPartial.

Answer 1

To avoid including core scripts twice

If your scripts have already been included through an earlier request, use this to avoid including them again:

// For jQuery core, Yii switches between the human-readable and minified
// versions based on DEBUG status; so make sure to catch both of them
Yii::app()->clientScript->scriptMap['jquery.js'] = false;
Yii::app()->clientScript->scriptMap['jquery.min.js'] = false;

If you have views that are being rendered both independently and as HTML fragments to be included with AJAX, you can wrap this inside if (Yii::app()->request->isAjaxRequest) to cover all bases.

To avoid including jQuery scripts twice (JS solution)

There's also the possibility of preventing scripts from being included twice on the client side. This is not directly supported and slightly more cumbersome, but in practice it works fine and it does not require you to know on the server side what's going on at the client side (i.e. which scripts have been already included).

The idea is to get the HTML from the server and simply strip out the <script> tags with regular expression replace. The important point is you can detect if jQuery core scripts and plugins have already been loaded (because they create $ or properties on it) and do this conditionally:

function stripExistingScripts(html) {
    var map = {
        "jquery.js": "$",
        "jquery.min.js": "$",
        "jquery-ui.min.js": "$.ui",
        "jquery.yiiactiveform.js": "$.fn.yiiactiveform",
        "jquery.yiigridview.js": "$.fn.yiiGridView",
        "jquery.ba-bbq.js": "$.bbq"
    };

    for (var scriptName in map) {
        var target = map[scriptName];
        if (isDefined(target)) {
            var regexp = new RegExp('<script.*src=".*' +
                                    scriptName.replace('.', '\\.') +
                                    '".*</script>', 'i');
            html = html.replace(regexp, '');
        }
    }

    return html;
}

There's a map of filenames and objects that will have been defined if the corresponding script has already been included; pass your incoming HTML through this function and it will check for and remove <script> tags that correspond to previously loaded scripts.

The helper function isDefined is this:

function isDefined(path) {
    var target = window;
    var parts = path.split('.');

    while(parts.length) {
        var branch = parts.shift();
        if (typeof target[branch] === 'undefined') {
            return false;
        }

        target = target[branch];
    }

    return true;
}

To avoid attaching event handlers twice

You can simply use a Javascript object to remember if you have already attached the handler; if yes, do not attach it again. For example (view code):

Yii::app()->clientScript->registerScript("view-script","
  window.myCustomState = window.myCustomState || {}; // initialize if not exists
  if (!window.myCustomState.liveClickHandlerAttached) {
    window.myCustomState.liveClickHandlerAttached = true;
    $('.link').live('click',function(){
       alert('test');
    })
  }
");