I have an Ember.js app that includes a template with a carousel that contains a scrollable list of 'activities.' I'm using a computed property to filter and return a collection of activities, which I then use to bind to my template, which populates the carousel. The computed property that provides the collection looks like this:
// simplified for clarity
activities: function () {
var model = this.get('model.content');
model.sort(function (a, b) {
return (a.get('type') > b.get('type') ? 1 : -1;
}.bind(this);
return model;
}.property('model', 'controllers.browse.filter')
Every time the controllers.browse.filter property changes, the activities computed property is re-calculated, and the new filter criteria is applied to the model, which is working without a problem.
However, I need to 'rebind' my carousel after the newly filtered model is returned. Right now, I'm trying to do that with an observer like so:
reloadCarousel: function () {
// pseudo code, not important to problem
carousel.reload();
}.observes('activities')
The problem is that reloadCarousel is being run as soon as the activities property starts changing, meaning the activities property has not had time to complete and return the new model collection before the reloadCarousel observer is fired. This doesn't work, because my carousel isn't able to bind to the newly filtered model.
I searched the Ember.js docs, but can't find anything that allows me to wait until a computed property has completely finished and returned all relevant data to my template.
Any suggestions or ideas are greatly appreciated!
The get method returns a promise, which you could wait to fulfill and then set the activities:
this.get('model.content').then(function(model) {
var activities = model.sort(function (a, b) {
return (a.get('type') > b.get('type') ? 1 : -1;
});
// set activities
});
Related
I expected a second argument to be passed to my computed property method, but it's not. I need this so I can call a setter to save my model with new data. Instead of that behavior, it appears that my computed property is called again right before I save the model, and clobbering the new values - the setter is never called at all because I only get one argument. Computed property:
changeBananas: function(k, v) {
var bananas = this.get('bananas'), bananaList = [];
console.log('args: ');
console.log(arguments);
bananaList = bananas.map(function(b) {
return { color: b.get('color') };
});
if (arguments.length > 1) {
console.log('I never get called!');
return bananaList;
}
return bananaList;
}.property('bananas.#each')
Full JSBin:
http://jsbin.com/razimaxu/2/edit
I tried propertyWillChange() and friends to try to stop observers, but it did not do anything. Is there another way to do this? My computed property is there to do some formatting of the items before displaying them in editable fields. I expected to be able to change said fields and save just like any other fields that are connected to regular model properties.
The only time it will receive both arguments is if you attempt to set the computed property, such as this.set('changeBananas', []).
It doesn't get called with both arguments if it has noticed a dependent property has changed.
Using Ember-Data 0.13-59 & Ember 1.0.0 RC 6 (from starter kit)
Problem: upon save() to a new record made from App.Userstat.createRecord({ ... }) the server gets the POST and successfully returns an id but the new record is not available in the Userstat model.
To better understand example: this is a quiz app(for multiple choice questions). Each question has several choices and when a user selects a choice, their choice to the corresponding question is stored in a Model, App.Userstat.
At each question, the app needs to know whether the user has already answered this question or if it's new.
I use a computed property as a setter and getter. The setter is called when a user selects a choice (the choice's value is passed to computed property). First it checks if a record exists for the user's current question. If it doesn't exist it will create a new record. If it does exist, it should only issue a PUT request with updated content.
Code Updated(July 8, 11AM)
App.UserstatsController = Ember.ArrayController.extend();
App.QuestionController = Ember.ObjectController.extend({
needs: "userstats",
chosen = function(key, value) {
// getter
if(value === undefined) {
// something goes here
// setter
} else {
// the question.id is used to compare for an existing record in Userstat mdoel
var questionId = this.get('id');
var questionModel = this.get('model');
// does any Userstat record belong to the current question??
var stats = this.get('controllers.Userstats');
var stat = stats.get('model').findProperty('question.id', questionId);
// if no record exists for stat, means user has not answered this question yet...
if(!stat) {
newStat = App.Userstat.createRecord({
"question" : questionModel,
"choice" : value // value passed to the computed property
)}
newStat.save(); // I've tried this
// newStat.get('store').commit(); // and this
return value;
// if there is a record(stat) then we will just update the user's choice
} else {
stat.set('choice', value);
stat.get('store').commit();
return value;
}
}.property('controllers.Userstats')
No matter how many times I set chosen it always sends a POST (as opposed to an update only sending a PUT request) because it never adds the record to the model the first time.
To demonstrate further, in the setter part of the computed property, when I put this code:
var stats = this.get('controllers.Userstats')
console.log stats
the Userstats controller shows all previously existing records, but not newly submitted records!
How come the new record isn't available after I save() or commit() it???
Thanks :)
EDIT
maybe it has something to do with me adding a record to the singular model App.Userstat and then when I look for it, I'm searching using the UserstatsController which is an Array controller???
I don't know if it's a typo, but the computed property is defined the wrong way and should be like this:
App.QuestionController = Ember.ObjectController.extend({
needs: 'userstats',
choice: 'controllers.userstats.choice',
chosen: function(key, value) {
...
}.property('choice')
...
});
Inside the property() you should also define properties that trigger the computed property if they change. This way if choice changes the chosen cp will be triggered.
Please let me know if it helps.
I'm looping through a content of an ArrayController whose content is set to a RecordArray. Each record is DS.Model, say Client
{{# each item in controller}}
{{item.balance}}
{{/each}}
balance is a property of the Client model and a call to item.balance will fetch the property from the model directly. I want to apply some formatting to balance to display in a money format. The easy way to do this is to add a computed property, balanceMoney, to the Client object and do the formatting there:
App.Client = DS.Model({
balance: DS.attr('balance'),
balanceMoney: function() {
// format the balance property
return Money.format(this.get('balance');
}.property('balance')
});
This serves well the purpose, the right place for balanceMoney computed property though, is the client controller rather than the client model. I was under the impression that Ember lookup properties in the controller first and then tries to retrieve them in the model if nothing has been found. None of this happen here though, a call to item.balanceMoney will just be ignored and will never reach the controller.
Is it possible to configure somehow a controller to act always as a proxy to the model in all circumstances.
UPDATE - Using the latest version from emberjs master repository you can configure the array controller to resolve records' methods through a controller proxy by overriding the lookupItemController method in the ArrayController. The method should return the name of the controller without the 'controller' suffix i.e. client instead of clientController. Merely setting the itemControllerClass property in the array controller doesn't seem to work for the moment.
lookupItemController: function( object ) {
return 'client';
},
This was recently added to master: https://github.com/emberjs/ember.js/commit/2a75cacc30c8d02acc83094b47ae8a6900c0975b
As of this writing it is not in any released versions. It will mostly likely be part of 1.0.0.pre.3.
If you're only after formatting, another possibility is to make a handlebars helper. You could implement your own {{formatMoney item.balance}} helper, for instance.
For something more general, I made this one to wrap an sprintf implementation (pick one of several out there):
Ember.Handlebars.registerHelper('sprintf', function (/*arbitrary number of arguments*/) {
var options = arguments[arguments.length - 1],
fmtStr = arguments[0],
params = Array.prototype.slice.call(arguments, 1, -1);
for (var i = 0; i < params.length; i++) {
params[i] = this.get(params[i]);
}
return vsprintf(fmtStr, params);
});
And then you can do {{sprintf "$%.2f" item.balance}}.
However, the solution #luke-melia gave will be far more flexible--for example letting you calculate a balance in the controller, as opposed to simply formatting a single value.
EDIT:
A caveat I should have mentioned because it's not obvious: the above solution does not create a bound handlebars helper, so changes to the underlying model value won't be reflected. There's supposed to be a registerBoundHelper already committed to Ember.js which would fix this, but that too is not released yet.
I have a fiddle http://jsfiddle.net/kristaps_petersons/9wteJ/2/ it loads 3 objects and shows them in a view. Data is shown alright, but i can not filter it before i show it.
This
nodes: function(){
this.get('controller.content').filter(function(item, idx, en){
console.log('should log this atleast 3x')
})
return this.get('controller.content')
}.property('controller.content')
method is called when template iterates over array of values, but it never goes in to the loop and print console.log('should log this atleast 3x') why is that?
You are trying to replace controller.content while also binding to it. You need to define another property, such as filteredContent and bind it to controller.content. Take a look at how Ember.SortableMixin computes the variable arrangedContent for controllers with a sortProperties variable defined. Using that method as a template I would implement it like this:
filteredContent: Ember.computed('content', function() {
var content = this.get('content');
return this.filter(function(item, idx, en) {
console.log('should log this atleast 3x');
});
}).cacheable()
This should be implemented in the controller, not the view. The controller is the place for data manipulation, computed properties, and bindings.
Then bind the view layout to filteredContent instead of content to show the filtered data. Then both the original content and the filtered content are available.
Ok i got it working, but it feels a bit strange. First i moved method to Controller class and changed it to look like this:
nodes: function(){
console.log('BEFORE should log this atleast 3x', this.get('content.length'))
this.get('content').forEach(function(item, idx, en){
console.log('should log this atleast 3x')
})
console.log('AFTER should log this atleast 3x', this.get('content.length'))
return this.get('content')
}.property('content').cacheable()
as it should be same as buuda's recomedation, because as i understand from docs .poperty() is the same as Ember.computed. As it was still not working, i changed .property('content') to .property('content.#each') and it was working. Fiddle: http://jsfiddle.net/kristaps_petersons/9wteJ/21/ . I guess, that tempate first creates a binding to controller.content and as content itself does not change does not notify this method again, instead template pulls data as it becomes available.
I have a DS.Store which uses the DS.RESTAdapter and a ChatMessage object defined as such:
App.ChatMessage = DS.Model.extend({
contents: DS.attr('string'),
roomId: DS.attr('string')
});
Note that a chat message exists in a room (not shown for simplicity), so in my chat messages controller (which extends Ember.ArrayController) I only want to load messages for the room the user is currently in:
loadMessages: function(){
var room_id = App.getPath("current_room.id");
this.set("content", App.store.find(App.ChatMessage, {room_id: room_id});
}
This sets the content to a DS.AdapterPopulatedModelArray and my view happily displays all the returned chat messages in an {{#each}} block.
Now it comes to adding a new message, I have the following in the same controller:
postMessage: function(contents) {
var room_id = App.getPath("current_room.id");
App.store.createRecord(App.ChatMessage, {
contents: contents,
room_id: room_id
});
App.store.commit();
}
This initiates an ajax request to save the message on the server, all good so far, but it doesn't update the view. This pretty much makes sense as it's a filtered result and if I remove the room_id filter on App.store.find then it updates as expected.
Trying this.pushObject(message) with the message record returned from App.store.createRecord raises an error.
How do I manually add the item to the results? There doesn't seem to be a way as far as I can tell as both DS.AdapterPopulatedModelArray and DS.FilteredModelArray are immutable.
so couple of thoughts:
(reference: https://github.com/emberjs/data/issues/190)
how to listen for new records in the datastore
a normal Model.find()/findQuery() will return you an AdapterPopulatedModelArray, but that array will stand on its own... it wont know that anything new has been loaded into the database
a Model.find() with no params (or store.findAll()) will return you ALL records a FilteredModelArray, and ember-data will "register" it into a list, and any new records loaded into the database will be added to this array.
calling Model.filter(func) will give you back a FilteredModelArray, which is also registered with the store... and any new records in the store will cause ember-data to "updateModelArrays", meaning it will call your filter function with the new record, and if you return true, then it will stick it into your existing array.
SO WHAT I ENDED UP DOING: was immediately after creating the store, I call store.findAll(), which gives me back an array of all models for a type... and I attach that to the store... then anywhere else in the code, I can addArrayObservers to those lists.. something like:
App.MyModel = DS.Model.extend()
App.store = DS.Store.create()
App.store.allMyModels = App.store.findAll(App.MyModel)
//some other place in the app... a list controller perhaps
App.store.allMyModels.addArrayObserver({
arrayWillChange: function(arr, start, removeCount, addCount) {}
arrayDidChange: function(arr, start, removeCount, addCount) {}
})
how to push a model into one of those "immutable" arrays:
First to note: all Ember-Data Model instances (records) have a clientId property... which is a unique integer that identifies the model in the datastore cache whether or not it has a real server-id yet (example: right after doing a Model.createRecord).
so the AdapterPopulatedModelArray itself has a "content" property... which is an array of these clientId's... and when you iterate over the AdapterPopulatedModelArray, the iterator loops over these clientId's and hands you back the full model instances (records) that map to each clientId.
SO WHAT I HAVE DONE
(this doesn't mean it's "right"!) is to watch those findAll arrays, and push new clientId's into the content property of the AdapterPopulatedModelArray... SOMETHING LIKE:
arrayDidChange:function(arr, start, removeCount, addCount){
if (addCount == 0) {return;} //only care about adds right now... not removes...
arr.slice(start, start+addCount).forEach(function(item) {
//push clientId of this item into AdapterPopulatedModelArray content list
self.getPath('list.content').pushObject(item.get('clientId'));
});
}
what I can say is: "its working for me" :) will it break on the next ember-data update? totally possible
For those still struggling with this, you can get yourself a dynamic DS.FilteredArray instead of a static DS.AdapterPopulatedRecordArray by using the store.filter method. It takes 3 parameters: type, query and finally a filter callback.
loadMessages: function() {
var self = this,
room_id = App.getPath('current_room.id');
this.store.filter(App.ChatMessage, {room_id: room_id}, function (msg) {
return msg.get('roomId') === room_id;
})
// set content only after promise has resolved
.then(function (messages) {
self.set('content', messages);
});
}
You could also do this in the model hook without the extra clutter, because the model hook will accept a promise directly:
model: function() {
var self = this,
room_id = App.getPath("current_room.id");
return this.store.filter(App.ChatMessage, {room_id: room_id}, function (msg) {
return msg.get('roomId') === room_id;
});
}
My reading of the source (DS.Store.find) shows that what you'd actually be receiving in this instance is an AdapterPopulatedModelArray. A FilteredModelArray would auto-update as you create records. There are passing tests for this behaviour.
As of ember.data 1.13 store.filter was marked for removal, see the following ember blog post.
The feature was made available as a mixin. The GitHub page contains the following note
We recommend that you refactor away from using this addon. Below is a short guide for the three filter use scenarios and how to best refactor each.
Why? Simply put, it's far more performant (and not a memory leak) for you to manage filtering yourself via a specialized computed property tailored specifically for your needs