I'm trying to clone form components using JQuery's .clone() (actually, I'm cloning a collection of fields by cloning the container element). Everything worked out well except that the datefield, comboboxes are not working, even the validation for minLength, etc. is also not working.
By the way, I'm just transforming an old html form fields to ext js form fields using applyTo
The problem is that jQuery clone() does not clone the event handlers
associated with DOM elements. But even if you use clone(true), that
does copy the event handlers, it still doesn't work, because you also
need to clone the Ext object on the JavaScript side.
You really need to use the tools provided by Ext to create many
similar controls. A good start is to create custom Ext components,
that you can then more easily instanciate multiple times.
For a start you can try using
.clone(true)
so all event handlers for an element are copied. Apart from that I suspect Extjs does some other funky stuff when building its controls therefore this is probably only the first step to getting it working. Looking around quickly on the extjs forums I dont see alot of info about cloning widgets.
Related
I want to create miller columns in angular 4. It can have any level of columns based on the input. And items from one column can be dragged and dropped in other columns.
My problem is attaching events for dynamically created elements in angular4. Like below code in jquery
$('.parentConstantDiv').on('click','.dynamicallyCreatedDiv',function(){
//Some task here
})
I could have used angular renderer but it allows to attach events only to window, document and body. But thats not jQuery handler mentioned above does.
Can someone help me to create handler like jQuery handler mentioned above in angular 4 component.
I got this pure java script method answer, but events are not removed when element is deleted from DOM.
Though I did not find exact answer to replicate the jQuery code in the question, I got something similar solution using this dynamic dom adding method.
Posting this answer so it might help someone else. Cheers!
I am facing an issue. I have a collection of object with size around 22K records. I need to bind this to an select element. Binding is working fine for small collection but such a big collection is freezing UI until its bind completely.
Please suggest the best I can do here....
First thing that pops to mind is using one-way data binding. That is accomplished by appending :: in front of your HTML variables like so
{{::someVar}}
This way, angular will not include someVar in its watchers.
If that is still not enough for you then you might consider writing a special type of select for your own purposes which can use something like ClusterizeJS behind it.
ClusterizeJS allows only rendering a few elements on the screen and re-rendering on scroll such that the user will never know that not all the elements already exist in the select. Couple this with a search bar and you've got yourself a very fast select.
In general it is not wise to populate a <select> element with such a huge number of records. That applies no matter which framework you are using (although it would be especially bad with Angular and two way data binding).
Where you want the user to be able to select from a large number of options, I would recommend using an 'autocomplete' style of interface, where the user types a few characters and the client fetches options that match what they have typed so far.
For example, you could use Angular-UI select
I'm just starting out in Angular, and I get the MVC model for organizing data architecturally, but I'm not sure about building custom UI elements without using jQuery (or vanilla js).
For example, I want to build a custom slider, sort of like a progress bar that a user can click (or touch) and drag to change the value. Is angular built for that, or would it require a hack-y solution? Would it be some combination of mouseover, mousedown, mousemove, mouseup events?
AngularJS has its own lite version of jQuery. The document is here: http://docs.angularjs.org/api/angular.element
It is not supposed to handle heavy DOM manipulation and it will not support such thing in the future. If you want to build a custom slider, there is a plug-in called angular-ui: http://angular-ui.github.io/
However, Angular-ui uses jQuery as well. I also notice they don't have a built-in slider component, so my suggestion is that first you should use angular.element, if this cannot satisfy whatever you need, use jQuery.
I'm trying to get dropdownchecklist jquery plugin working with ko. I've wired up custom binding handler but dropdown won't populate with options. Please check my fiddle: http://jsfiddle.net/amitava82/wMH8J/11/
Appreciate your help. Thanks!
This is because you create dropdown before binding KnockoutJS. How does this dropdown work? It creates additional divs and spans which copy the content of select and create nice looking list. After that bindings are applied and they modify the select (as they should), but dropdown is not updated, because this library is kind of static, i.e. it copies the content of select only at the time of calling.
I've updated your jsFiddle so you can see temporary fix. What I mean is that it works now, the binding is applied before creating dropdown. The only problem is that changing options field in viewModel won't affect the dropdown. What you probably need to do is to use subscribe method. You have to monitor changes to options field and if they occur you have to recreate the dropdown. That's an easy way at least.
#freakish answer will work for most static content, but for anything dynamic using templates, for example if or foreach bindings, or you need to support underlying data updates, such as more checkbox options "suddenly" becoming available, it will not work.
An example of a really simple $.button binding apply which can be used to wrap the more simple jQuery calls. It's a simple matter of adding more members to controls to make them available in bindings.
The case with jQuery Dropdown Check List is a bit tricky however, since you obviously want to use the built in options handler, but you need to run $.dropdownchecklist after the options handler has run, as it creates the DOM elements that jQuery depends on. By wrapping the built in options handler, we are always called in the correct context.
In my experience of usage (our project makes use of about 10-15 custom bindings), you'll average about 10-20 lines of actual JS. If you start ballooning into +100 lines, I find it's a good idea to refactor, and rethink. I hope this helps some :-) I've been using Knockout for a few months now at a major UI implementation project at work, I've really learned alot, and I'm amazed at this stuff.
I have a custom built ajax [div] based dynamic dropdown.
I have an [input] box which; onkeyup, runs an Ajax search which returns results in divs and are drawn back in using innerHTML. These divs all have highlights onmouseover so, a typical successful search yields the following structure (pardon the semi-code):
[input]
[div id=results] //this gets overwritten contantly by my AJAX function
[div id=result1 onmouseover=highlight onclick=input.value=result1]
[div id=result2 onmouseover=highlight onclick=input.value=result2]
[div id=result2 onmouseover=highlight onclick=input.value=result2]
[/div]
It works.
However, I'm missing the important functions behind regular HTML elements. I can't keyboard down or up between "options".
I know javascript handles keyboard events but; I haven't been able to find a good guide. (Of course, the follow-up question will end up being: can I use <ENTER> to trigger that onclick event?)
What you need to do is attach event listeners to the div with id="results". You can do this by adding onkeyup, onkeydown, etc. attributes to the div when you create it or you can attach these using JavaScript.
My recommendation would be that you use an AJAX library like YUI, jQuery, Prototype, etc. for two reasons:
It sounds like you are trying to create an Auto Complete control which is something most AJAX libaries should provide. If you can use an existing component you'll save yourself a lot of time.
Even if you don't want to use the control provided by a library, all libraries provide event libraries that help to hide the differences between the event APIs provided by different browsers.
Forget addEvent, use Yahoo!’s Event Utility provides a good summary of what an event library should provide for you. I'm pretty sure that the event libraries provided by jQuery, Prototype, et. al. provide similar features.
If that article goes over your head have a look at this documentation first and then re-read the original article (I found the article made much more sense after I'd used the event library).
A couple of other things:
Using JavaScript gives you much more control than writing onkeyup etc. attributes into your HTML. Unless you want to do something really simple I would use JavaScript.
If you write your own code to handle keyboard events a good key code reference is really handy.
Off the top of my head, I would think that you'd need to maintain some form of a data structure in the JavaScript that reflects the items in the current dropdown list. You'd also need a reference to the currently active/selected item.
Each time keyup or keydown is fired, update the reference to the active/selected item in the data structure. To provide highlighting information on the UI, add or remove a class name that is styled via CSS based on if the item is active/selected or not.
Also, this isn't a biggy, but innerHTML is not really standard (look into createTextNode(), createElement(), and appendChild() for standard ways of creating data). You may also want to see about attaching event handlers in the JavaScript rather than doing so in an HTML attribute.