Ok, I have written some classes/functions that allow me to bind specific behaviors to certain DOM elements. I want to group all the behaviors for certain elements together, so I create a plugin/function that uses delegate to set up all the functionality I want. As an example, say I want all of my forms to pass through a validation check before submitting, and I also want some text to appear when someone exists an input field (these are just examples). So I've written my own form plugin to automatically handle all these capabilities. It might look something like this:
jQuery.fn.myFormPlugin = function(options){
this.each(function(){
$(this).submit(function(event){
blah blah blah...
});
$(this).children("input").bind("focus",function(){
blah blah blah...
});
});
}
And then when the page loads, I simply invoke it via:
$("form.mySpecialForm").myFormPlugin();
All that works great. But now say I am loading some of these forms via Ajax. How can I automatically bind the plugin to all forms, whether loaded normally or via ajax? I don't believe I can use bind, delegate or live as these can't be associated with a "load" event, so I am stuck. I suppose I could call the plugin as part of the success callback in the ajax load, but then I would have to do that individually with each ajax load.
And I have other plugins to use in a similar way for other DOM elements, like tabs, accordions, etc., so I am looking for something of a holistic approach.
Thanks very much in advance.
You can add custom events - and then trigger those custom events when you need to.
a walk through example: http://www.reynoldsftw.com/2009/04/custom-events-in-jquery-open-doors-to-complex-behaviors/
Related
I'm new with Ember and I would like to show a full screen overlay when a user presses a "get stuff from the server" button.
What is the best way to achieve this?
Does Ember already provide something built-in? Or is it that the only way is to have a piece of HTML in one of my templates, to show/hide it when the promise where I make the AJAX call returns?
You have a few options available to you.
The first concerns a route change. Conventionally speaking, if the user is hitting a button that transitions to another route, a separate route can be created to handle this in-between loading experience.
To describe this briefly, if you have a route named foo, creating a sibling route named foo-loading with an associated template, will show a "foo-loading" page state while things are being fetched, and then dismiss it once things are good.
Alternatively, as you've hinted, if the call to action for a user intends an updated result on the same route, a loading service could be useful. In your application template, you could have a loading div that is hidden by default. Prior to initiating an AJAX request, you could turn the loading state on and reveal the loading div. Then, once the AJAX call is settled, the finally block could include a call to conceal the loading div.
This latter approach would involve a conditionally loaded block in the primary application template, a loading service handling show and hide, and a loading template.
You could use ember-modal-dialog to create a loading screen component that gets rendered when you're waiting for your ajax request.
For example:
// view.js
showLoadingScreen: true
// view.html
{{#if showLoadingScreen}}
{{loading-screen}}
{{/if}}
// loading-screen.html
{{#ember-modal-dialog}}
<div class="loader-full-screen-class"></div>
{{/modal-dialog}}
The advantage of the component/ember-modal-dialog is that this pattern is usually implemented as a modal, and this library is the standard in ember. The component then allows you to put it anywhere you need it to be.
I am not sure if I am adding my JS assets correctly and would like some advice if I am not.
In octoberCMS I have created a custom formWidget that uses the Google Maps API.
I am using my formWidget inside a child form that is rendered via AJaX as a modal when required.
If I use the following code in my widget class:
public function loadAssets(){
$this->addJs("http://maps.googleapis.com/maps/api/js?key=myappkeyhere&libraries=places");
$this->addJs('js/geocomplete/jquery.geocomplete.min.js');
$this->addJs('js/addressinput.js');
$this->addCss('css/addressinput.css');
}
The JS loads with the Page load and not when the widget is rendered. This produces these issues:
The google-maps API returns an error saying it has been loaded multiple times.
Events tied to DOM elements in the child fail since the elements are not in the DOM until the form is called.
The workaround I am using is to embed my JS into the formWidget partial.
Is there a way to make the addJS method work for the formWidget when it is part of a child form?
After some investigation, I realised that my formWidget using the addJs() method would make the widget JS available globally to the entire page even before the formWidget existed or was even needed.
While I could have created an elaborate, fancy JS involving listeners for DOM insertions and blah blah blah, this was not ideal (mainly because the widget properties change based on implementation).
The quickest/safest way to include JS that is tightly bound to a complex formWidget is to include it in the partial. This ensures the form widget will work properly both in a standalone form and in situations where the widget is part of child form that is created via an Ajax load.
(If you know of a better way please let me know)
I want to get the list of all events for any particular component dynamically. For example : If I take a Textfield , how can I get all possible events that are mentioned in ExtJs API Doc. so that user can choose and assign the event for any component.
component.events
Contains the list you need. You could have found out by yourself reading the source of addEvents method, which is linked from any event you wanted to find in a list.
For those still wanting an answer to this, https://coderwall.com/p/jnqupq/easily-capture-all-events-on-a-component-in-extjs has provided a nice means of doing so.
When debugging an ExtJS application, you'll often find it useful to listen to all events fired by a specific component. There is actually a handy built-in static method to do this called Ext.util.Observable.capture().
Here's a handy snippet that simply logs the event name and all arguments:
Ext.util.Observable.capture(myObj, function(evname) {console.log(evname, arguments);})
Even better, if you're currently inspecting your component's main element in your browser's developer tools, you can do this:
Ext.util.Observable.capture(Ext.getCmp($0.id), function(evname) {console.log(evname, arguments);})
Where $0 is the currently selected element. Should work fine in Chrome, Firefox, Opera, Safari.
If you don't want those logs to pollute your console anymore, simply call releaseCapture on your object:
Ext.util.Observable.releaseCapture(myObj);
This removes all captures on a given object so you don't have to reference your listener explicitly (which was likely an anonymous function :)).
Bonus tip: also be sure to check out the observe method which does something similar but allows you to listen to all events fired by all instances of a given class.
Working on a Wicket application that adds markup to the DOM after onLoad via Wicket's built-in AJAX for an auto-complete widget. We have an IE6 glitch that means I need to reposition the markup coming in, and I am trying to avoid tampering with the Wicket javascript... blah blah blah... here's what I'm trying to do:
New markup arrives in the DOM (I
don't have access to a callback)
Somehow I know this, so I fire my
code.
I tried this, hoping the new tags would trigger onLoad events:
$("selectorForNewMarkup").live("onLoad", function(){ //using jQuery 1.4.1
//my code
});
...but have become educated that onLoad only fires on the initial page load. Is there another event fired when elements are added to the DOM? Or another way to sense changes to the DOM?
Everything I've bumped into on similar issues with new markup additions, they have access to the callback function on .load() or similar, or they have a real javascript event to work with and live() works perfectly.
Is this a pipe dream?
.live() doesn't work like this, it's a common misconception. .live() creates an event handler at the DOM root and waits for events to bubble up to it. If the selector matches the event target, .live() will fire the bound event.
It doesn't look for new objects and bind events to them in any way, rather it just listens for a bubble, and doesn't care when that object was added to the DOM.
You need to fire whatever code is needed to run manually when your load operation completes.
What will this is the livequery plug-in, look specifically at the livequery( matchedFn ) call.
You can do something like this:
$('#myID').livequery(function() { $(this).offset()...stuff });
i guess this is what you are looking for http://ananthakumaran.github.com/2010/02/19/wicket-post-ajax-handling.html
I've implemented a few poor solutions for bringing up an AJAX loader before dynamically updating a content DIV, but none seem to be "universal", and I find each time I do it I'm reworking it. If I have a DIV with content that updates depending on what a user clicks on the page, and I want to display the loader over this content DIV, what is the best approach? I've seen some developers have the loader always on the page, and they just display it block or none, and I've seen others append it to the DIV. What about when you also have multiple areas that can update? I'm thinking something repeatable that I can call with a function, maybe passing a few parameters.
Some JavaScript libraries allow listening to opening and closing requests. Check out Prototype's request Responder http://www.prototypejs.org/api/ajax/responders.
You would do something like this:
Ajax.Responders.register({
onCreate: function() {
$('loader').show();
Ajax.activeRequestCount++;
},
onComplete: function() {
Ajax.activeRequestCount--;
if (Ajax.activeRequestCount < 1) $('loader').hide();
}
});
As for visual representation of loading, you may want to identify the different parts of your page which may require separate loading graphics and subclass the Request object, each time indicating the type of request.
E.g.
Is it a field being saved? new FieldUpdateRequest(field)
Is it the page being loaded? new Request();
Is a container being updated? new PartialRequest(div);
Then capture each subclasses type and show or hide a different loader graphic.
There is unfortunately no quick solution, hal. You could build a generic script for appending loader graphics to containers, that should save you some repetition. If you do, mind posting it here :)?
You could use a JQuery progress bar or something similar in a different library.