Changing in model not affected on a view ember - javascript

I try to add data to model manually like this
beforeModel: function() {
var scope =this;
Ember.$.getJSON('/restURL').then(function(response){
scope.store.pushPayload('consultation',response);
},
and data successfully loaded, I can see it in ember debugger, but I have a problem - data is not render on a view.
template in application.hbs:
{{#each item in model}}
{{#link-to 'consultation' item}}{{item.remoteUser.name}}{{/link-to}}
{{/each}}
NOTE: when I load data using this.store.find('consultation'); it's work fine, but I have custom URL and can't use this construction.

As I understand it, you want to load consultations using a direct ajax call. The way you are doing it now, the consultations are retrieved in beforeModel, then, since you are not returning the promise, Ember immediately proceeds to execute the model hook before the ajax calls completes. The this.store.find you have in the model hook is likely to make another, possibly invalid request to the server. The easiest way is simply
model: function() {
var store = this.store;
return Ember.$.getJSON('/restURL')
.then(function(response) {
store.pushPayload('consultation', response);
return store.all('consultation');
});
}
Note the use of store.all, which is a dynamic collection of all objects of that type already in the store.
You could also consider breaking the logic into beforeModel and model as in:
beforeModel: function() {
return Ember.$.getJSON('/restURL')
// this binding style is a matter of personal preference :-)
.then(this.store.pushPayload.bind(this.store, 'consultation'))
},
model: function() {
return this.store.all('consultation');
}

You should use afterModel hook instead of beforeModel, because beforeModel is not use for data aggregation. beforeModel occurs before the model try to get resolved, it can not access the resolved model, so you can't rely on it to add extra data to model.
On the other hand, afterModel hook will pass the resolved model in as the first argument, so you can further decorate the model as your needs, and you can return a promise just like the model hook.
Take look this simple example: http://emberjs.jsbin.com/nukebe/1

Related

Accessing asynchronously loaded object based on relations in Ember

I have a trouble with asynchronously loaded models in Ember. I thought I have already understood the whole "background Ember magic", but I haven't.
I have two models, let's say foo and boo with these properties:
foo: category: DS.belongsTo("boo", { async: true })
boo color: DS.attr("string")
In my route, I load all foos:
model: function(params) {
return this.store.findAll("task", "");
},
than in my template I render a component: {{my-component model=model}}. In the component's code I need to transform the model into another form, so I have:
final_data: function() {
this.get("model").forEach(function(node) {
console.log(node.get("category"));
});
return {};
}.property("model"),
When I try to access the "category" in the model, my code crashes:
EmberError#http://localhost:4200/assets/vendor.js:25705:15
ember$data$lib$adapters$errors$$AdapterError#http://localhost:4200/assets/vendor.js:69218:7
ember$data$lib$adapters$rest$adapter$$RestAdapter<.handleResponse#http://localhost:4200/assets/vendor.js:70383:16
ember$data$lib$adapters$rest$adapter$$RestAdapter<.ajax/</hash.error#http://localhost:4200/assets/vendor.js:70473:25
jQuery.Callbacks/fire#http://localhost:4200/assets/vendor.js:3350:10
jQuery.Callbacks/self.fireWith#http://localhost:4200/assets/vendor.js:3462:7
done#http://localhost:4200/assets/vendor.js:9518:1
.send/callback#http://localhost:4200/assets/vendor.js:9920:8
It seems to me, like the Ember didn't load the boos. How should I access them right to make Ember load them?
It's trying to load category, but the adapter is encountering some error. Can't tell what from your example.
Check your network tab.
When you access an async association from a template, Ember knows what to do. From code, such as your component's logic, Ember has no idea it needs to retrieve the association until you try to get it. The get will trigger the load, but will return a promise. You can do this:
get_final_data: function() {
Ember.RSVP.Promise.all(this.get("model") . map(node => node.get('category'))
.then(vals => this.set('final_data', vals));
}
As I'm sure you can see, this creates an array of promises for each node's category, calls Promise.all to wait for them all to complete, then stores the result into the final_data property.
Note, this is not a computed property; it's a function/method which must be called at some point, perhaps in afterModel.

ember.js, filtering PromiseManyArray in the controller

I am trying to define a computed property that consists of a filtered hasMany relationship. When I loop over the items of the PromiseManyArray, I get undefined when trying to access the attribute I want to filter on. On later calls to this computed property, everything works fine.
This is a simplified version of my controller code:
export default Ember.Controller.extend({
availableModules: function () {
let thisModule = this.get('model')
console.log(thisModule.get('library.modules')) // This logs <DS.PromiseManyArray:ember604>
// loop over siblings
return thisModule.get('library.modules').filter(mod => {
// mod.classification is undefined
return mod.get('classification') !== 'basis'
})
}.property('model')
})
For the Module model we can assume that it has a classification attribute, and it belongs to a Library object, and the Library model hasMany modules.
I have tried something like this, and it logs properly the attribute classification, but I don't know how to return anything so that the template can render it.
availableModules: function () {
let thisModule = this.get('model')
thisModule.get('library.modules').then(mods => {
mods.forEach(mod => {
console.log(mod.get('classification'))
})
})
}.property('model')
So the problem seems to be that inside of the PromiseManyArray.filter method, the attributes of the found objects are not yet resolved... How can I create a promise that will return all filtered objects once those have been resolved? I don't know how to get my head around this. Thanks.
Inspired by Bloomfield's comment, and with help of this thread in the ember forum, I have found an acceptable solution. Basically it consists of resolving all the relationships in the route, so that when the controller is called, you don't have to deal with promises.
Solution:
In the model hook of the route, return a hash of promises of all the needed information
Define a custom setupController, and inside of it, store the model and the extra data in the controller
The route code looks like this:
export default Ember.Route.extend({
model(params) {
let module = this.store.findRecord('module', params.mod_id)
return Ember.RSVP.hash({
module: module,
siblingModules: module.then(mod => mod.get('library.modules')), // promise based on previous promise
})
},
setupController(controller, hash) {
controller.set('model', hash.module)
controller.set('siblingModules', hash.siblingModules)
},
})
Note: for the route to still work properly, the {{#link-to 'route' model}} have to explicitly use an attribute, like the id: {{#link-to 'route' model.id}}
Extra info
Bloomfield's approach consisted of using the afterModel hook to load the extra data in an attribute of the Route object, and then in the setupController, set the extra data in the Controller. Something like this:
export default Ember.Route.extend({
model(params) {
return this.store.findRecord('module', params.mod_id)
},
afterModel(model) {
return model.get('library.modules').then(modules => {
this.set('siblingModules', modules)
})
},
siblingModules: null, // provisional store
setupController(controller, model) {
controller.set('model', model)
controller.set('siblingModules', this.get('siblingModules'))
},
})
But this feels like a hack. You have to return a promise in afterModel, but you can't access the result. Instead the result has to be accessed via .thenand then stored in theRoute` object... which is not a nice flow of information. This has however the advantage that you don't have to specify any attribute for the links in the template.
There are more options like using PromiseProxyArray, but that's too complicated for a newcomer like me.
For anyone running into PromiseManyArray issues in modern times, make sure you have async: false explicitly set on any hasMany relationships directly serialized by the API. Modern versions of Ember will behave unexpectedly if you don't, such as computed properties not working when you use pushObject.

Ember route or controller expose data model as json

I am trying to work with Ember.js
Can I expose my data model as JSON through a route or controller?
I have an object like this saved in the store:
this.store.createRecord('Person', {
id: 1,
name: this.get('name'),
email: this.get('email')
});
I want to expose this data from a route or controller as JSON object. I don't want to use any view.
Is it possible to do this?
Thanks for help!
EDIT
My route is:
App.ResultRoute = Ember.Route.extend({
model: function() {
return this.store.find('person', 1);
}
});
There is '1' because I want only this record.
In this way It works and I see in the view the {{name}} and the {{email} of the Person object.
I want to see only the JSON, I tried to do how you suggest me :
App.ResultRoute = Ember.Route.extend({
afterModel: function (model) {
model.get('content').forEach(function (item) {
console.log(item.get('content'));
});
}
});
But I receive this error:
Uncaught Error: Assertion Failed: Error: More context objects were passed than there are dynamic segments for the route: error
What is my error?
The way I would do this would be, I would have an api in my model which would return a plain json object to whoever asked it. So the Person model would have a getPersonDetails method which will hide all the internal details, including the attributes and associations and whatever else, and return the state of the person object it is invoked upon.
So, for example, if you wanted to display a table of persons or something, you would do a createRecord, and just ask the newly created person object for it's details.
Start from the beginning of this guide. http://emberjs.com/guides/routing/specifying-a-routes-model/ It will show you how to specify a model for a route.
Then, read this entire guide on controllers: http://emberjs.com/guides/controllers/
In general, you would access that data from the route's model hook with:
this.store.find('person') // All records
If you wanted to access that first object as JSON, you could do:
var person_JSON = this.store.find('person').then(function (persons) {
//The persons records are now available so you can do whatever you want with them
console.log(persons.objectAt(0).get('content'));
});
You could also iterate over all records and strip out the content to produce raw json without the Ember wrapping... Just depends on what you need to really do.
Really the best place to put this would be the route's afterModel hook, though. You wouldn't be working with a promise, as Ember would have dealt with that for you:
afterModel: function (model) {
model.get('content').forEach(function (item) {
console.log(item.get('content'));
});
}
Hope that helps.
Edit: Since you have one record try this:
afterModel: function (model) {
console.log(model.get('content'));
}

backbone.stickit and html-form: How to save (patch) only changed attributes?

tl;dr
How to use backbone.stickit with a html form to change an existing model fetched from the server and only PATCH the changed attributes (changed by user input within the html form) to the server?
/tl;dr
I'm using backbone.stickit in a backbone.js application to bind a model to a HTML-form which is part of a backbone view. This works fine so far, but it becomes a little bit complicated if I'm going to save the bound model. This is because I want to use the PATCH-method and only send the changed attributes to the server. I try to illustrate what I've done so far:
Fetching the model from Server
user = new User(); //instatiate a new user-model
user.fetch(); //fetching the model from the server
console.log(user.changedAttributes()); // Returns ALL attributes, because model was empty
The last line indicates my problem, because I thought I can used the changedAtrributes() method later to get the attributes which need a patch on the server. So I tried this workaround which I found here
user.fetch({
success: function (model, response, options) {
model.set({});
}
});
user.changedAtrributes(); //Returns now "false"
Do stickit-bindings
Now I render my view and call the stickit() method on the view, to do the bindings:
//Bindings specified in the view:
[...]
bindings: {
"#username" : "username"
"#age" : "age"
}
[...]
//within the render method of the view
this.stickit();
The bindings work fine and my user model gets updated, but changedAttributes() remain empty all the time.
Save the model to the server
If the user has made all required changes, the model should be saved to the server. I want to use the PATCH method and only send the changed attributes to the server.
user.save(null, {patch:true}); //PATCH method is used but ALL attributes are sent to the server
OR
user.save(user.changedAttributes(),{patch : true});
With the second approach there are different outcomes:
if I didn't use the user.set({}) woraround, all attributes get PATCHED to the server
if I use the user.set({}) woraround the return value of changedAttributes() is "false" and all attributes are PUT to the server
if I call a user.set("age","123") before calling save(), then only the age attribute is PATCHED to the server
So outcome 3 is my desired behaviour, but there are 2 problems with this: First stickit doesn't seem to use the set() method on the model to update the attributes if they are changed within the html-form. And second, if you call set() with one attribute and afterwards with another, only the second attributes is returned by changedAttributes().
Maybe I just overseen something in the backbone or backbone.stickit docs, so I didn't get the desired behaviour working. Any ideas about that?
NOTE: As found out the problem wasn't directly related to backbone.stickit, more to backbone itself.
Solved this problem on my own, maybe this helps someone who may stumble upon this question:
Backbone only keep track of unchanged attributes, but not of unsaved attributes. So with
model.changedAttributes();
you will only get the attributes of the model, which was changed since the last
model.set("some_attribute","some_value")
Finally I stumbled upon backbone.trackit which is a backbone.js plugin maintained by the creator of backbone.stickit. With this plugin you can track unsaved attributes (all attributes which have changed since the last model.save()) and then use them in the save-method of a model. Example (my usecase):
Backbone.View.extend({
bindings: {
"#name" : "name",
"#age" : "age"
},
initialize: function () {
this.model = new User();
this.model.fetch({
success: function (model, response, options) {
//this tells backbone.stickit to track unsaved attributes
model.startTracking();
}
});
},
render: function () {
this.$el.html(tmpl);
this.stickit();
return this;
},
onSaveUserToServer: function () {
//first argument: only unsaved attributes, second argument: tell backbone to PATCH
this.model.save(this.model.unsavedAttributes(), { patch: true });
});
});

setupController not being called when using {{linkTo}} or transtionTo("path", model);

Is there any reason why setupController would not get called when using {{linkTo}}? I have two instances in my app where linkTo is being used, and in the second case. It doesn't work. The only difference that I can see is that in the first case linkTo is being used in a loop, and in the second it's not. Below is relevant code for the non-working one:
App.Router.map(function() {
this.resource("search", { path: "/search/:args" });
});
App.SearchCriteria = Ember.Object.extend({ });
App.SearchRoute = Ember.Route.extend({
serialize: function(model, params) {
// .. some code that converts model to a string called args
return {'args': args}
},
model: function(params) {
// convert args, which is query string-formatted, to an object
// and then make a App.SearchCriteria object out of it.
return App.SearchCriteria.create($.deparam(params.args));
},
setupController: function(controller, model) {
controller.set("searchCriteria", model);
}
});
In the search template:
{{view Ember.Checkbox checkedBinding="searchCriteria.music"}} Music
{{#linkTo search searchCriteria}}Search{{/linkTo}}
The last thing I see in the logs is:
Transitioned into 'search'
Normally, I'd see the setupController being called at some point, but it's not happening or some reason. I even tried using the {{action}} method to call a handler and then use transtionTo, but that had the same results.
UPDATE 1: Adding more details
The only difference between the working and non-working cases is that in the working case, the {{linkTo}} is being called from the same template as that of the controller and router (i.e., the linkTo is in the search template and it's invoking the SearchRoute). In the working case, the linkTo is being called on the SearchRoute but from a different template belonging to a different router).
After some Chrome debugging of Ember code, I found out that the router isn't being called is because partitioned.entered is empty. In the working case, it is non-empty.
var aborted = false;
eachHandler(partition.entered, function(handler, context) {
if (aborted) { return; }
if (handler.enter) { handler.enter(); }
setContext(handler, context);
if (handler.setup) {
if (false === handler.setup(context)) {
aborted = true;
}
}
});
UPDATE 2: Root issue found - bug?
I think I understand the root cause of why the handler isn't being triggered, and I think it's because the partitionHandlers(oldHandlers, newHandlers) method doesn't think that the model has changed, thus doesn't fire the handler.
To be specific, this is the relevant part of the view:
{{view Ember.Checkbox checkedBinding="searchCriteria.music"}} Music
{{#linkTo search searchCriteria}}Search{{/linkTo}}
Although the user checks off the checkbox (thus changing the state of searchCriteria), Ember doesn't think that searchCriteria is any different, thus doesn't do anything.
Is this a bug?
I'm not sure what your problem is, but this may help.
setupController is called every time the route is entered. But model hook may not be called every time.
See Ember guide: http://emberjs.com/guides/routing/specifying-a-routes-model/
Note: A route with a dynamic segment will only have its model hook called when it is entered via the URL. If the route is entered through a transition (e.g. when using the link-to Handlebars helper), then a model context is already provided and the hook is not executed. Routes without dynamic segments will always execute the model hook.
Genrally speaking, if you click the link generated by link-to to enter the route, Ember will not call model hook for that route. Instead it passes the model (link-to parameter) to that route.
The philosophy here is since the client already has the model context, Ember think there is no need to get it again from server (that's model hook's job).

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