backbone, javascript mvc - styling views with javascript - javascript

A few of my views need their textareas converted to rich text editors.
I'm using jwysiwyg as the editor. It requires that the element it is being attached to is in the page when the editor is initialized i.e. when I call $(this.el).wysiwyg(), this.el is already in the document.
Most of my views do not actually attach themselves to the dom - their render methods simply set their elements html content using the apps templating engine e.g. $(this.el).html(this.template(content)
Views/Controllers further up the chain look after actually inserting these child views into the page. At the same time, views do re-render themselves when their models change.
How do I ensure that the editor is attached to the element every time its rendered and still ensure that the editor is not attached until the element is already in the page?
Obviously I could hack something together that would work in this particular case but I would like an elegant solution that will work for all cases.
Any help would be much appreciated.
Edit: The main point here is that the solution must scale gracefully to cover multiple elements that must be styled after rendering and must not be styled until they are in the DOM
Edit: This is not an issue if I do top-down rendering but this is slow, I'd like a solution whereby I can render from the bottom up and then insert the complete view in one go at the top
Edit:
Using a combination of some of the techniques suggested below I'm thinking of doing something like the following. Any comments/critique would be appreciated.
app/views/base_view.js:
initialize: function() {
// wrap the render function to trigger 'render' events
this.render = _.wrap(this.render, function() {
this.trigger('render')
});
// bind this view to 'attach' events.
// 'attach' events must be triggered manually on any view being inserted into the dom
this.bind('attach', function() {
this.attached();
// the refreshed event is only attached to the render event after the view has been attached
this.bind('render', this.refreshed())
// each view must keep a record of its child views and propagate the 'attach' events
_.each(this.childViews, function(view) {
view.trigger('attach')
})
})
}
// called when the view is first inserted to the dom
attached: function() {
this.style();
}
// called if the view renders after it has been inserted
refreshed: function() {
this.style();
}
style: function() {
// default styling here, override or extend for custom
}

What if you used the JQuery LiveQuery Plugin to attach the editor? Such code could be a part of your template code, but not as HTML, but as Javascript associated with the template. Or you could add this globally. The code might look like this (assuming you've included the plugin itself):
$('textarea.wysiwyg').livequery(function() {
$(this).wysiwyg();
});
I have not tested this code, but in theory it should match an instance of a textarea element with a class of 'wysiwyg' when it appears in the DOM and call the wysiwyg function to apply the editor.

To adhere to DRY principle and get an elegant solution, you'll want a function dedicated to determining if a textarea has wysiwyg, let's say wysiwygAdder and add it if necessary. Then you can use underscore's wrap function to append your wysiwyg adder to the end of the render function.
var View = Backbone.View.extend({
el: '#somewhere',
initialize: function(){
_.bind(this, "render");
this.render = _.wrap(this.render, wysiwygAdder);
},
render: function(){
//Do your regular templating
return this;//allows wysiwygAdder to pick up context
}
});
function wysiwygAdder(context){
$('textarea', context).doYourStuff();
//check for presence of WYSIWYG, add here
}
When the view is initialized, it overwrites your render function with your render function, followed by wysiwygAdder. Make sure to return this; from render to provide context.

One solution would be to use event delegation and bind the focus event to check whether the rich text editor had been loaded or not. That way the user would get the text editor when they needed it (via the lazy loading, a minor performance improvement) and you wouldn't have to load it otherwise. It would also eliminate needing to worry about when to attach the rich text editor and that being dependent on the rendering chain.
If you're worried about the FOUC (flash of unstyled content) you could simply style the un-modified text areas to contain an element with a background image the looked just like the wysiwyg controls and have your focus binding toggle a class to hide the facade once the rich text editor had taken over.
Here's a sample of what I had in mind:
var View = Backbone.View.extend({
el: '#thing',
template: _.template($("#template").html()),
render: function() {
// render me
$(this.el).html(this.template(context));
// setup my textareas to launch a rich text area and hide the facade
$(this.el).delegate('focus', 'textarea', function() {
if(!$(this).hasRichTextEditor()) { // pseudocode
$(this).wysiwyg();
$(this).find('.facade').toggle();
}
});
}
});

Great problem to solve! Not too sure I've got the entire jist but... You may be able to get away with a 'construction_yard' (I just made that term up) that's way off to the left, build and place items there, then just move them when they're ready to be placed. Something along the lines of:
.construction_yard {
position: absolute;
left: -10000000000px;
}
This solution may fix several problems that might crop up. For example jquery height and width attributes on something that's 'hidden' are 0, so if you are styling along those lines, you'd have to wait till it was placed, which is more complicated, and jumbles things up.
your views would then need to do something along the lines of (pseudo-code):
//parent
//do all your view-y stuff...
foreach (child = this.my_kids) {
if child.is_ready() {
put_that_child_in_its_place();
}
}
Similarly, for children, you'd do a similar thing:
//child
foreach(parent = this.my_parents) {
if parent.isnt_ready() {
this.go_play_in_construction_yard();
} else {
this.go_to_parents_house();
}
}
... and, since backbone is pretty easy to extend, you could wrap it up in a more generalized class using:
var ParentsAndChildrenView = Backbone.View.extend({blah: blah});
and then
var Wsywig = ParentsAndChildrenView.extend({blah: blah});
hope that helps!
Almost forgot to note my source:
http://jqueryui.com/demos/tabs/#...my_slider.2C_Google_Map.2C_sIFR_etc._not_work_when_placed_in_a_hidden_.28inactive.29_tab.3F

Related

Add class to dynamically generated HTML

I'm working to use custom checkbox styles with a checkbox which is dynamically generated by javascript for the Google Identity Toolkit. For example, we add this div:
<div id="gitkitWidgetDiv"></div>
And the Google Identity Toolkit script generates new html for that div.
I need to add a class to the HTML which is added by the javascript without any action by the user and I'm struggling to make it work. For example, here is my code:
$("#gitkitWidgetDiv").on('ready', ".gitkit-sign-in-options label", function() {
$(this).addClass('checkbox');
});
I've tried switching 'ready' for a few other options and also using the livequery plugin, but nothing is working for me. It works if I use an active event like 'click,' but I can't figure out how to do this when the page loads. Could someone please help? Thanks!
Modern browsers (including IE11) support mutation obervers. You can use one to monitor the parent node of the div that will be added. When the div has been added, just add the class.
Here's something I made which comes in handy in annoying cases like this where it's difficult to tell when the element you need has finished loading in: https://gist.github.com/DanWebb/8b688b31492632b38aea
so after including the function it'd be something like:
var interval = 500,
stopTime = 5000,
loaded = false;
setIntervalTimeout(function() {
if($('.dynanicElementClass').length && !loaded) {
$('.dynanicElementClass').addClass('checkbox');
loaded = true;
}
}, interval, stopTime);
It's not perfect and I'm sure there are better solutions out there but in most cases like this it does the job.

CKEditor widget: how do I attach css in onLoad

I'm writing a CKEditor widget. As I am trying to make it easily distributable, I want to make my css external. While this syntax works:
CKEDITOR.plugins.add('myplugin', {
requires: 'widget',
icons: 'myplugin',
init: function(editor) {
CKEDITOR.dialog.add('myplugin', this.path + 'dialogs/myplugin.js');
var self = this;
editor.on('contentDom', function() {
editor.document.appendStyleSheet(CKEDITOR.getUrl(self.path + 'css/style.css'));
});
}
});
I found that CKSource uses onLoad: function(editor){} in their image2 widget to attach css. This looks more canonical than my code. I'm getting editor = undefined though. What's the catch?
Update:
I'm using the framed option and I definitely want to stay DRY through .appendStyleSheet() to user-facing page as well as to the wysiwyg framed editor. However, I still have problem with init/beforeInit:function(editor), where editor does not seem to have document property populated at that very moment. When I do window.ed = editor though, then I can access the window.ed.document in the console once the page is ready. So, is there any kind of deferred promise going on there? Maybe I'm complicating things, but I definitely want to append a distributable stylesheet and remove it easily.
I found this working:
beforeInit: function(
var ccss = CKEDITOR.config.contentsCss;
if(typeof ccss == 'string'){
ccss = [ccss];
}
ccss.push('/css/style.css'); // <-- my css installed at website root
CKEDITOR.config.contentsCss = ccss;
console.log(CKEDITOR.config.contentsCss);
},
While the issue with isolated css stylesheet might sound over-complicated, I want to achieve an easily demoable state without the need to touch existing files.
Note that in the image2 plugin stylesheet is not added to editor instance, but using CKEDITOR.addCss:
CKEDITOR.plugins.add( 'image2', {
...
onLoad: function( editor ) {
CKEDITOR.addCss( ' ... ' );
}
} );
It is a mistake that the editor is specified as an argument - it always will be null.
If you want to add stylesheet manually using document.appendStyleSheet, then do it on init, or beforeInit, not on onLoad.
Altough, you should know that contentDom will be fired multiple times for one document, e.g. when setting data. So in your case stylesheet would be added many times. Therefore, if you want to add a stylesheet for the framed editor (the one using iframe), you can use config.contentsCss, and if you want to add it for inline editor, then you can freely call:
CKEDITOR.document.appendStyleSheet( ... );
In plugin's onLoad (will be called only once). So most likely you'll want to do both things, to handle inline and framed editors.

How do we set an onExpand event in a cfLayout accordion

We're using CFLayout to create a tab structure in our web application. After creation of that layout we call this function:
mytabs = ColdFusion.Layout.getTabLayout("#attributes.cflayoutName#");
mytabs.on('tabchange',
function(tablayout,tab) {
var tabtitle = tab.title;
alert(tabtitle); // Actual code does various useful 'stuff' here.
}
);
That piece of code works very well, and the alert will show each time the user clicks on a tab.
The problem is that we are now trying to do the same thing with a CFLayout type of "accordion", and I cannot get an event to fire when the user switches which accordion pane they are looking at. We've tried leaving the above as is, as well as changing the "tabchange" attribute to "expand", "beforeexpand", "activate", and "collapse".
For this testing I'm using the following simple JS function to avoid issues arising from the JS within the onchange event:
mytabs = ColdFusion.Layout.getAccordionLayout("#attributes.cflayoutName#");
mytabs.on('expand',
function(tablayout,tab) {
console.log('test');
}
);
We do not receive any errors. Nothing is logged to the console at all. I've tried replacing the console.log to an alert to rule out any problems with that line.
I found that the Ext library documentation to be very helpful with finding a solution to this problem: here.
The Ext library has a getComponent method that allows you to reference the accordion layout panel that you are trying to add the expand event to. Once you have this, you can use the "on" method you are using above to assign the expand event to each panel individually.
for (x=1; x<accordionLayoutArray.length; x++) {
mytabs.getComponent(accordionPanelName).on('expand',
function(tab) { ... });
}
This became too long for a comment so adding as an answer
After some Google searches I found what I think are some related posts. It appears as though the accordion in Ext JS does not have the same events as the tab. Instead you need to add a listener in order to catch the expanding.
See this post - in case something happens to that page here is the relevant piece:
You'd need to listen to the expand event of the child panels in the accordion, you could do something like:
Code:
myAccordion.add(myFunc('myTitle'));
function myFunc(title)
{
return new Ext.Panel(
{
title: title,
listeners: { 'expand': {fn: something, scope: foo}}
}
);
}
And I also found another similar post here on SO - see both answers
Once you know that the accordion needs a listener you can find a number of results on Google. Such as How do I attach an event handler to a panel in extJS?
This Google search will give you lots of examples.
Hope that helps.

OnSubtreeModified add my function

I use pie.js (http://css3pie.com/) a library that allows me to have css3 on ie6+. I apply pie.js on document.ready :
$(document).ready(function(){
if (window.PIE) {
$('.vexClass, #vexId').each(function(){
PIE.attach(this);
});
}
});
My problem is when the dom was modified the elements for which I have apply pie.js are not rendering well so I must load my function that apply pie.js to my elements when the dom is modified and only for section that was modified using OnSubtreeModified or another technique ... For example I have a panel that is displayed when dom was loaded, in that panel I have a button that is expanding another panel with buttons and other elements for which I want to apply pie.js, so for main panel all elements for which I have applied pie.js are rendered ok but the elements from expanded panel, pie.js is not applied :|
So how can I inject that pie.js when dom is modified for expanded panel?
Thank's.
If you are using wicket the only way to do that is through Wicket.Ajax.registerPostCallHandler
Add this in your project, every time when a ajax request is done your pie will be applied.
window.document.ready = function() {
Wicket.Ajax.registerPostCallHandler(pieStarter);
}
function pieStarter() {
if (window.PIE) {
go();
}
}
function go() {
$(''.vexClass, #vexId'').each(function() {
PIE.attach(this);
});
}
Do you get your data from an Ajax call? If so, you need to add the pie in the callback. There is no possibility (at least afaik) to add anything on something that you don't have at a given time.
If you need to add the pie in the callback, you should make an separate function for that. You can give a dom node to the function and it checks for every child node if pie is applied, and if not it does so.
You can't use the DOMSubtreeModified event since older versions of IE - which you are targeting - don't support this. You can, however, work around this by using this answer Detect changes in the DOM together with this script:
$(document).ready(function () {
function applyPIE() {
if (window.PIE) {
$('.vexClass, #vexId').not('[data-pie=attached]').each(function(){
PIE.attach(this);
$(this).attr('data-pie', 'attached');
});
}
}
onDomChange(function(){
alert('document updated, applying PIE now');
applyPIE();
});
$('#link').click(function () {
$('body').append('<h4>added content</h4>');
});
applyPIE();
});
It creates a local function applyPIE() which is called on document ready and every time the DOM changes - filtering out already processed elements. You may want to expand the .vexClass, #vexId set of selectors to match your needs.
JSFiddle: http://jsfiddle.net/hongaar/y3FaM/1/

Backbone :: Using jQuery Plugins on Views

I'm having trouble figuring out a clean way to do this. Let's take for an example a code snippet from the example todo app that comes with backbone:
addOne: function(todo) {
var view = new TodoView({model: todo});
$("#todo-list").append(view.render().el);
},
So the ToDo view is being rendered and then it's being appended to #todo-list. But let's suppose we want to add a jQuery plugin to ToDo view. Where should we place the $(".todo").plugin() snippet? If we place it inside the ToDo view render function the HTML element is not set on the page, so the plugin won't 'latch' to any DOM element. If we place this inside the addOne function it will look ugly.
So, what's the best way?
The answer largely depends on the plugin you're talking about.
For example, most of the jQueryUI controls and the KendoUI controls allow you to call the plugin method from the render of the view, directly, before the HTML is attached to the DOM. You simply call it on the view's el.
For example, if I wanted to use KendoUI's menu on a view that generated:
Backbone.View.extend({
tagName: "ul",
render: function(){
var html = "<li>foo</li><li>bar</li>";
this.$el.html(html);
this.$el.kendoMenu();
}
});
There are some plugins that require the HTML to be a part of the DOM already, for whatever reason. In this case, I typically provide an onShow function in my views, and have the code that is displaying the view check for this and call it if it exists.
For example, there's a "Layout" plugin that I've used a few times. This plugin requires the HTML to be part of the DOM before it can work:
MyView = Backbone.View.extend({
render: function(){
var html = "generate some html here...";
this.$el.html(html);
},
onShow: function(){
this.$el.layout();
}
});
// .... some other place where the view is used
var view = new MyView();
view.render();
$("#someElement").html(view.el);
if (view.onShow) {
view.onShow();
}
FWIW: I've written the code for onShow and other common methods and events dozens of times, and have consolidated it all into a Backbone add-on called Backbone.Marionette, so that I don't have to write it anymore.
http://github.com/derickbailey/backbone.marionette
There's a lot more than just this available in this add-on, of course.
You can use the backbone $ method like so this.$('todo') to use context scoped jquery querying which will allow you to search in the current view DOM fragment which wasn't added to the document DOM tree yet.
From my experience adding jquery plugin binding in either render method or some kind of helper function if there was more custom bindings which would be then called from render method after the template was created.

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