I know how to update and redraw a jqPlot object without using ember...
I created the following fiddle to show the "problem": http://jsfiddle.net/QNGWU/
Here, the function load() of App.graphStateController is called every second and updates the series data in the controller's content.
First problem: The updates of the series seem not to propagate to the view.
Second problem: Even if they would, where can i place a call to update the plot (i.e. plotObj.drawSeries())?
I already tried to register an observer in the view's didInsertElement function:
didInsertElement : function() {
var me = this;
me._super();
me.plotObj = $.jqplot('theegraph', this.series, this.options);
me.plotObj.draw();
me.addObserver('series', me.seriesChanged);
},
seriesChanged: function() {
var me = this;
if (me.plotObj != null) {
me.plotObj.drawSeries({});
}
}
But that didn't work...
Well, figured it out, see updated fiddle.
The secret sauce was to update the whole graphState object (not just it's properties) in App.graphStateController:
var newState = App.GraphState.create();
newState.set('series', series);
me.set('content', newState);
And then attach an observer to it in the App.graphStateView:
updateGraph : function() {
[...]
}.observes('graphState')
The updateGraph function then isn't pretty, since jqPlot's data series are stored as [x,y] pairs.
The whole problem, i guess, was that the properties series and options in the App.graphState object itself are not derived from Ember.object and therefore no events are fired for them. Another solution may be to change that to Ember.objects, too.
Related
I have a component which is inserted into the DOM as a '' tag (e.g., default behaviour). The component's job is to wrap a 3rd party jQuery tool and I'm trying to ensure it is responsive to "resize" events so I would like to explicitly set width and height style attributes.
In the component, it is easy enough to being to the style attribute:
attributeBindings: ['style'],
style: function() {
return "width: auto";
}.property('widthCalc'),
In this case, this works but doesn't do anything useful because style just returns a static string (width: auto).
Instead what I want to do is -- based on any change to the computed property widthCalc -- set the width based on the new value. So here's the next logical step:
style: function() {
var width = $('body')[0].offsetWidth;
return 'width: ' + width + 'px';
}.property('widthCalc'),
This too works, dynamically setting the DIV to the width of the body's width (note: this isn't really what I want but it does prove that this simple binding works). Now what I really want is to get the value of width from a computed property on the component but I don't even have to go that far to run into trouble; notice that instead of a global jQuery selector I switch to a localised component-scoped selector:
style: function() {
var width = this.$().offsetWidth;
return 'width: ' + width + 'px';
}.property('widthCalc'),
Unfortunately this causes the page NOT to load and gives the following error:
Uncaught Error: Something you did caused a view to re-render after it rendered but before it was inserted into the DOM.
I imagine this is Ember run-loop juju but I'm not sure how to proceed. Any help would be appreciated.
Since it is not possible to call this.$() in the component before it has been added to the dom, provide an initial value until the component is ready.
For example,
Setting a default value to the property style and on didInsertElement event reopen the class and define style as a calculated property using this.$()
http://emberjs.jsbin.com/delexoqize/1/edit?html,js,output
js
App.MyCompComponent = Em.Component.extend({
attributeBindings:["style"],
style:"visibility:hidden",
prop1:null,
initializeThisStyle:function(){
this.set("style","visibility:visible");
this.reopen({
style:function(){
// var thisOffsetWidth = this.$().get(0).offsetWidth;
return "visibility:visible;color:red;background-color:lightgrey;width:"+this.get("prop1")+"px";
}.property("prop1")
});
}.on("didInsertElement")
});
Alternatively handle the error raised by this.$() and provide a default value. Afterwards when the component will be added the property will be calculated as planned.
http://emberjs.jsbin.com/hilalapoce/1/edit?html,js,output
js
App.MyCompComponent = Em.Component.extend({
attributeBindings:["style"],
style:function(){
try{
this.$();//this will throw an erro initialy
return "visibility:visible;color:red;background-color:lightgrey;width:"+this.get("prop1")+"px";
}catch(e){
return "color:blue";
}
}.property("prop1"),
prop1:null
});
With the component I was trying to solve for I ended coming up with an solution that seems effective to me which I will share below. For an understanding of the why I was getting the error and how one might more directly address that error please see the comment from #melc above.
My Solution
What I'm solving for is resizing a jQuery component wrapped in an Ember component. In many cases, resizing is handled gracefully by CSS alone but some jQuery components -- including the very nice knob component from aterrien -- has JS which gets directly involved and therefore needs the containers width and height properties to be set explicitly by the Ember component so that it reacts appropriately.
When solving for this I realised my use-case had two problems:
Solving for a page resize event
Adjusting to the fact that my knob component was -- at times -- in the DOM but in a part of the DOM which was not visible (more explicitly it was in Bootstrap tab which wasn't visible).
The Resize Listener
The first part of the solution is to listen for a page-level resize of the page. I do this with the following:
resizeListener: function() {
var self = this;
self.$(window).on('resize', Ember.run.bind(self, self.resizeDidHappen));
}.on('didInsertElement'),
Page Resize Handler
When a resize is done at the "page" level I now want my component to inspect what the resize impact has been on the component:
resizeDidHappen: function() {
Ember.run.debounce(this, function() {
// get dimensions
var newWidth = Number(this.$().parent().get(0).offsetWidth);
var newHeight = Number(this.$().parent().get(0).offsetHeight);
// set instance variables
this.set('width', newWidth);
this.set('height', newWidth);
// reconfigure knob
this.$('.knob').trigger(
'configure',
{
width: newWidth,
height: newWidth
}
);
}, 300);
}
This solves the page resize problem if it exists in isolation but to make the component it is probably a good idea to solve for the visibility use case as well (certainly in my case it was critical).
Visibility Handler
Why? Well, for two reasons that I can think of:
Many jQuery components refuse to load or perform badly if they aren't loaded
The ember component appears to not be able to establish a "resize" event when it is not visible in the DOM
The one problem is that there is no DOM-level event for visibility changes, so how do we react to a change in visibility without polling on an interval? Well in most cases there will be a UI element which is controlling the state of visibility. In my case it's Bootstrap's tab bar and in this case they have events that fire on the tabs when they become visible. Great. Here's a selector for Bootstrap's selector (assuming you're inside the content area of the newly visible tab):
visibilityEventEmitter: function(context) {
// since there is no specific DOM event for a change in visibility we must rely on
// whatever component is creating this change to notify us via a bespoke event
// this function is setup for a Bootstrap tab pane; for other event emmitters you will have to build your own
try {
var thisTabPane = context.$().closest('.tab-pane').attr('id');
var $emitter = context.$().closest('.tab-content').siblings('[role=tabpanel]').find('li a[aria-controls=' + thisTabPane + ']');
return $emitter;
} catch(e) {
console.log('Problem getting event emitter: %o', e);
}
return false;
},
visibilityEventName: 'shown.bs.tab',
then we just need to add the following code:
_init: function() {
var isVisible = this.$().get(0).offsetWidth > 0;
if (isVisible) {
this.visibilityDidHappen();
}
}.on('didInsertElement'),
visibilityListener: function() {
// Listen for visibility event and signal a resize when it happens
// note: this listener is placed on a DOM element which is assumed
// to always be visibile so no need to wait on placing this listener
var self = this;
Ember.run.schedule('afterRender', function() {
var $selector = self.get('visibilityEventEmitter')(self);
$selector.on(self.get('visibilityEventName'), Ember.run.bind(self, self.visibilityDidHappen ));
});
}.on('didInsertElement'),
visibilityDidHappen: function() {
// On the first visibility event, the component must be initialised
if(!this.get('isInitialised')) {
this.initiateKnob();
} else {
// force a resize assessment as window sizing may have changed
// since last time component was visible
this.resizeDidHappen();
}
},
Note that this also results in a tiny refactor of our resize listener, removing it's trigger from the didInsertElement event and instead being triggered by initiateKnob which will happen not when the Ember component loads but instead lazy load at the first point of visibility in the DOM.
initiateKnob: function() {
var self = this;
this.set('isInitialised', true);
var options = this.buildOptions();
this.$('.knob').knob(options);
this.syncValue();
this.resizeDidHappen(); // get dimensions initialised on load
console.log('setting resize listener for %s', self.elementId);
self.resizeListener(); // add a listener for future resize events
},
resizeListener: function() {
this.$(window).on('resize', Ember.run.bind(this, this.resizeDidHappen));
},
Does it work?
To a large degree but not completely. Here's what works:
the first 'tab' which is visible at load resizes on demand
all tabs resize when they are switched to (aka, when they gain visibility)
what doesn't work is:
tabs other than the first tab do not resize (aka, the onresize callback appears broken)
The error I get is:
vendor.js:13693 Uncaught TypeError: undefined is not a function
Backburner.run vendor.js:13716
Backburner.join vendor.js:34296
run.join vendor.js:34349
run.bind vendor.js:4759
jQuery.event.dispatch vendor.js:4427
jQuery.event.add.elemData.handle
Not sure what to make of this ... any help would be appreciated. Full code can be found here:
https://gist.github.com/295e7e05c3f2ec92fb45.git
I need to add a webkitTransitionEnd event listener to one of the DOM elements in my EmberView.
This javascript (DOM) equivalent would be:
function transitionEnded() {
console.log("transition ended");
}
document.getElementById('foo').addEventListener(
"webkitTransitionEnd",
this.transitionEnded,
true);
I've tried the following:
var MessageView = Ember.View.extend({
...
transitionEnded: function() {
console.log("Transition Alert!");
},
actions: {
closeMessageWithTransition: function(){
var elem = document.getElementById('transitionThis');
elem.addEventListener(
"webkitTransitionEnd", this.transitionEnded, true);
// Trigger the transition here
}
...
I've also tried using:
this.$("#transitionThis").get(0).addEventListener(...);
instead of using:
var elem = document.getElementById('transitionThis');
elem.addEventListener(...);
but to no avail. The transition happens, but I do not get any events nor do I see errors in the console.
I can confirm that the document.getElementById method selects the right element. So, where are my event handlers going?
EDIT 1: Didn't realize there was an emberjs.jsbin.com. So, here you go:
Emberjs.jsbin
PS: I do realize that the element I'm attaching a listener to ends up getting destroyed later when in transitionTo('messages') but I've commented out that bit and still no effect.
EDIT 2: I've added an alternate method of trying to catch the event using an EventManager as outlined in the Ember.View docs.
Alternate Method
It looks like it's using animation, not transition, webkitAnimationEnd is the appropriate hook.
http://emberjs.jsbin.com/awEWUfOd/4/edit
On the Ember MVC TodoApp there is an option "Clear all Completed".
I've been trying to do a simple "Clear All".
I've tried multiple things, none of them work as I expected (clearing the data, the local storage and refreshing the UI).
The ones that comes with the sample is this code below:
clearCompleted: function () {
this.filterProperty(
'completed', true
).forEach(this.removeObject, this);
},
My basic test, that I expected to work was this one:
clearAll: function () {
this.forEach(this.removeObject, this);
},
Though, it's leaving some items behind.
If I click the button that calls this function in the Entries controller a couple times the list ends up being empty. I have no clue what's going on! And don't want to do a 'workaround'.
The clearCompleted works perfectly by the way.
The answer depends on what you really want to know-- if you want to clear an ArrayProxy, as per the question title, you just call clear() on the ArrayProxy instance e.g.:
var stuff = ['apple', 'orange', 'banana'];
var ap = Ember.ArrayProxy.create({ content: Ember.A(stuff) });
ap.get('length'); // => 3
ap.clear();
ap.get('length'); // => 0
This way you're not touching the content property directly and any observers are notified (you'll notice on the TodoMVC example that the screen updates if you type Todos.router.entriesController.clear() in the console).
If you're specifically asking about the TodoMVC Ember example you're at the mercy of the quick and dirty "Store" implementation... if you did as above you'll see when you refresh the page the item's return since there is no binding or observing being done between the entry "controller" and the Store (kinda dumb since it's one of Ember's strengths but meh whatev)
Anywho... a "clearAll" method on the entriesController like you were looking for can be done like this:
clearAll: function() {
this.clear();
this.store.findAll().forEach(this.removeObject, this);
}
Well, this worked:
clearAll: function () {
for (var i = this.content.length - 1; i >= 0; i--) {
this.removeObject(this.content[i]);
}
},
If someone can confirm if it's the right way to do it that would be great!
I am trying to inject another component into an element that is rendered by the template of another Coomponent..but in the afterrender event, the template is yet to be rendered so the call to Ext.get(el-id) returns null: TypeError el is null.
tpl:
new Ext.XTemplate(
'<tpl for=".">',
'<ul>',
'<li class="lang" id="cultureSelector-li"></li>',
'</ul>',
'</tpl>'
),
listeners: {
afterrender: {
fn: function (cmp) {
console.log(Ext.get('cultureSelector-li')); // < null :[
Ext.create('CultureSelector', {
renderTo: 'cultureSelector-li'
});
}
}
},
So when can I add this component so that the element is targeting has been created in the DOM?
I think it depends on the component that you are working with. For example, the Data Grid View has a "viewready" event that would suite your needs, and depending what you are attempting, the "boxready" function could work for combo box (only the first render though). Other than that, you can either go up through the element's parent classes searching for the XTemplate render function being called (might be in the layout manager) and extend it to fire an event there, or risk a race condition and just do it in a setTimeout() call with a reasonable delay.
I ended up having to do the work myself. So, I now have the template as a property called theTpl, and then rendered it in beforerender, and then i was able to get a handle on the element in afterrender. This seems wholly counter-intuitive, does anyone have any insight?
beforeRender: {
fn: function (me) {
me.update(me.theTpl.apply({}));
}
},
edit in fact I just extended Component thus:
Ext.define('Ext.ux.TemplatedComponent', {
extend: 'Ext.Component',
alias: 'widget.templatedComponent',
template: undefined,
beforeRender: function () {
var me = this;
var template = new Ext.XTemplate(me.template || '');
me.update(template.apply(me.data || {}));
me.callParent();
}
})
...template accepts an array of html fragments
Turns out I was using the wrong things - apparently we should be using the render* configs for this type of thing (so what are thetpl & data configs for?)
Here's a working fiddle provided for me from the sencha forums:
http://jsfiddle.net/qUudA/10/
I have a model built from a JSON object.
// extend the json model to get all props
App.Model = Ember.Object.extend(window.jsonModel);
I want to automatically save the model when anything is updated. Is there any way I can add an observer to the whole model?
EDIT: // adding the solution I currently go
For now I do:
// XXX Can't be right
for (var prop in window.jsonModel) {
if (window.jsonModel.hasOwnProperty(prop)) {
App.model.addObserver(prop, scheduleSave);
}
}
This is a large form, which means I'm adding tons of observers – it seems so inefficient.
A firebug breakpoint at Ember.sendEvent() reveals that there are events called App.model.lastName:change being sent. I could hack in an intercept there, but was hoping for an official way.
You can bind to isDirty property of subclass of DS.Model. The isDirty changes from false to true when one of model properties changes. It will not serve well for all cases because it changes only once until reset or committed, but for your case -
I want to automatically save the model when anything is updated. Is there any way I can add an observer to the whole model?
it may work fine.
From the article:
autosave: function(){
this.save();
}.observes('attributes'),
save: function(){
var self = this,
url = this.get('isNew') ? '/todos.json' : '/todos/'+this.get('id')+'.json',
method = this.get('isNew') ? 'POST' : 'PUT';
$.ajax(url, {
type: 'POST',
// _method is used by Rails to spoof HTTP methods not supported by all browsers
data: { todo: this.get('attributes'), _method: method },
// Sometimes Rails returns an empty string that blows up as JSON
dataType: 'text',
success: function(data, response) {
data = $.trim(data);
if (data) { data = JSON.parse(data); }
if (self.get('isNew')) { self.set('id', data['todo']['id']); }
}
});
},
isNew: function(){
return !this.get('id');
}.property('id').cacheable(),
I had the same requirement, and not finding a suitable answer, I implemented one.
Try this: https://gist.github.com/4279559
Essentially, the object you want to observe all the properties of MUST be a mixed of Ember.Stalkable. You can observe the properties of that object as 'item.#properties' (or, if you bake observers directly on the Stalkable, '#properties' alone works. "#ownProperties", "#initProperties" and "#prototypeProperties" also work, and refer to (properties that are unique to an instance and not defined on any prototype), (properties that are defined as part of the create() invocation), and (properties that are defined as part of the class definition).
In your observers, if you want to know what properties changed and invoked the handler, the property "modifiedProperties", an array, will be available with the names of the changed properties.
I created a virtual property _anyProperty that can be used as a dependent key:
import Ember from 'ember';
Ember.Object.reopen({
// Virtual property for dependencies on any property changing
_anyPropertyName: '_anyProperty',
_anyProperty: null,
propertyWillChange(keyName) {
if (keyName !== this._anyPropertyName) {
this._super(this._anyPropertyName);
}
return this._super(keyName);
},
propertyDidChange(keyName) {
if (keyName !== this._anyPropertyName) {
this._super(this._anyPropertyName);
}
return this._super(keyName);
}
});