Ember View loses content - ember.js

I am working on a bit of code to show a D3 chart using Ember fixture data as the source for the data. The charts show up just fine on the first load of the page but if I move to a different route & then return to the first route (the one with the working chart) the chart simply disappears. So I guess my question is, how do I get the chart to appear every time the route is visited? Here is what my Route and View code looks like, will add more code if requested.
Updated with JS Bin: http://jsbin.com/ihapaz/2/edit

The route may not be getting any data when you return back to it. When using linkTo the model hooks are not fired. The setupController is called directly with the model that you pass to linkTo. However if the route depends on the model hook having fired to load it data then the view would be empty as it wouldn't have any data to render.
That's the only thing that comes to mind from the above code. Try posting a jsbin if this doesn't work.
Edit: Post jsbin
After looking at your jsbin I realized my earlier answer was incorrect. In general it is true that linkTo skips the model hook, but only if dynamic segments are present. Your route has no dynamic segments. Hence the model hook will always be called, so the view/chart is getting data correctly.
The error is in your implementation of render. The purpose of the render method is to push strings of html onto the DOM. This isn't the appropriate place for custom DOM insertion. For that you need to put things on the didInsertElement method.
I made these changes, renaming render to didInsertElement and the corresponding updateChart. Here's the updated jsbin.

Related

Rerender view after change route's dynamic segment

I have a Route with dynamic segment :id. When I change only the dynamic segement part manually in browser url input field, then goes a transition, and all model hooks are called as expected.
The problem is: none of the views are rerendered. I guess it is because only model changed - not the UI. But I have some UI logic in views' didInsertElement handler - reinitialize UI plugins and so on.
How to force ember to rerender view after dynamic segment change?
I agree with the josh's comment. if you are rerendering views with the change of dynamic segment means your code is not written properly. But still if you want to go like that i am gonna give is a part of code.
In your route:
model: function(params){
model.set('id', params.id);
}
In your view which needs to be rerendered:
_modelIdChange: function(){
this.rerender();
}.observes('controller.model.id')
But i don't suggest this. I would rather prefer proper bindings. But i did use rerendering in some cases which mostly when you end up using jquery plugins.

Integrating external JS libraries in Ember

I have a simple application that uses jqplot to graph data. This application has a single route attached to an ArrayController. I display the items to be graphed on the left side using the {{#each}} helper; I also display a 'graph' button up top. The user can select one or more entries from the list and hit the graph button. The button is attached to an action that calls jqplot to graph the selected data on the right side. Functionally, this works fine, but feels like a hack. Does anyone have an opinion on how this can be re-structured to perform similar function the 'Ember way'?
This app only has one model, so doesn't seem like I would need a second route. I do need to somehow handle re-graphing if the user resizes the window. If I weren't using Ember, I would handle window resizing like this:
$(window).resize(function(){
plot1.replot ({resetAxes: true});
});
where 'plot1' is the return value from the original call to jqplot.
How do I do this in Ember?
I'm using Ember 1.4 with EmberData beta 7.
You can put custom JS code in the didInsertElement() hook of your view, which will be executed after the view is rendered.
There's a corresponding willDestroyElement() hook for your teardown code.

Reloading a route's model with server json data and need ember-related opinion

I’m building a map with a search function. Basically, I’d like to store objects from the server within my ember app so that whenever I search for something that collection updates itself with the results from the server so the related view updates itself. It’s all on one page.
So far I have an Application Controller, and a Results ArrayController. Data is shown from the Results Controller. Now I’d need that when a search is requested, it gets JSON from the server and updates the results collection.
First question would be:
How would you build that?
I did a v1 with jQuery only and started a new one with Ember but I’m lost as of how structure-wise should I build it.
I built a small jsbin based on what I have here: http://emberjs.jsbin.com/IYuSIXE/1/
Second question:
How would I change a route's model content? Am I going in the wrong direction?
Thanks a lot
You can do both 1 and 2 with query params, check the documentation here https://github.com/alexspeller/website/blob/a96d9afe4506454b155cc64299e86e558ce3c9f1/source/guides/routing/query-params.md
When your route calls the model it will pass the query params, you can do your search against them
model:function( params, queryParams, transition ) { callToYourBackedEndWithQueryParams}
Second question: How would I change a route's model content? Am I
going in the wrong direction?
When the search is requested, in an action you can call this.transitionTo({queryParams: {sort: 'asc'}});, that will fire up again the model hook and you can do the query against your server again.
What I was looking for is a way to change the model on-the-fly.
So basically if I have this:
App.ResultsRoute = Ember.Route.extend({
model: function() {
// empty array that will contain results
return [];
}
});
I can do this to set the content of the model:
this.get('model').setObjects([{}, {}, {}]);
That way I can dynamically play with the models, load them with objects coming from almost anywhere.

Cannot read property 'container' of null when using linkTo helper in an Ember template

I am creating an Ember application as an add-on to some HTML returned from the server. I need this HTML so that the site can be indexed by search engines, and also to speed up the initial page rendering for the users.
So my application consists of several Ember Views, appended to different DOM elements of the HTML generated by the server. I don't use master templates for routes, so I set renderTemplate function of each route to do nothing.
My Ember App is bound to body element and I can successfully append a custom view to an element down the tree. It works:
In this JSFiddle three last elements of the list are appended by Ember
But when I try to use linkTo helper in my template, I hit an error:
Uncaught TypeError: Cannot read property 'container' of null ember-latest.js:32224
which is in this function:
router: Ember.computed(function() {
return get(this, 'controller').container.lookup('router:main');
}),
In this JS fiddle I just add linkTo to the template, and it breaks everything
In general, can Ember work this way - having many Views scattered
over the HTML rendered by the server?
How can the example code be
fixed?
I've fixed your fiddle here, Check it out.
Seems like you are starter to Ember,
So here are some tips for you,
You should have an application template, which will be the root template and on which all the templates will be rendered.
You shouldn't access views using this.container.lookup, that is for debugging only.
You shouldn't append views to the DOM, it's the job of the framework to do.
By default your application will be appended to the body of the html, if you want it to be appended elsewhere, give the rootElement property when creating the application. Refer here for configuring your application.
The rootElement can be either a DOM element or a jQuery-compatible selector string. Note that views appended to the DOM outside the root element will not receive events. If you specify a custom root element, make sure you only append views inside it!
Don't access any controllers globally like App.itemsController.set("content", model), if you want to access another controller inside a route, use this.controllerFor, and to access inside another controller, use needs.
You need not create any controller instance like App.itemsController=Ember.ArrayController.extend({}).create();
The framework will take care of all these.
I found that I need to additionally bind the view and the container together to make this fiddle work
App.itemsView.set("controller", App.itemsController);
App.itemsController.set("container", this.container);
So the resulting working code snippet is here:
http://jsfiddle.net/ddegtyarev/6cBRx/6/
Again, let me reiterate that I'm building an hybrid Ember application - i.e. I have some HTML returned right from the server, and some appended by multiple Ember views in multiple places. This is why I have to manually create the views and bind them with controllers etc.

Ember: Cannot read property 'enterStates' of undefined and textfield update

I have the following problem with ember.
I have a table with a set of datas. I have an event that returns me the current element of the table. Then it opens another view by transitioning into a new state and writes the selected table data in a textfield.
click: function(e) {
var element = $(e.target).closest("td");
App.tee = element.text().trim();
var router;
router = this.get('controller.target.router');
router.transitionTo('newRoute')
As you can see I have some other routes in my router as well.
The last two routes(home and profile) are part of a nav-tab. They work perfectly beside I click on the table. Then i get the following error when i click on a tab: Uncaught TypeError: Cannot read property 'enterStates' of undefined
Ok i give it another try to explain what i wanted to do.
What i want to do is to create a table with some data (for example persons).
When i click on a specific person in the table the corresponding table-data should be shown in the textfields that appear below. Whenever i click on another person the textfields below should change to the informations of the current clicked person in the table. When i click "New" Button a more detailed Tabview appears on the right side with some additional informations. I was playing around with ember and so far i just implemented some of the views and the routing. Im stucked as i have tried to implement the event that updates the textfield below the table. It updates once but after it has transitioned into the new state(newRoute) nothing happens. I know the code is very raw, but it is just a test to understand how this works in ember.
Ok the solution was easier than i thought. The problem was not the state changing. It was more a problem of how to access the data and how to effect the change of binded data. I realised too late that i needed to understand how the variable access works in Ember and what exactly the App.initialize() method does. So App.initialize() initializes all Controller classes in the router. If you want to access any variables within a controller you have to get the access over the router like
{{view Ember.TextField valueBinding="App.router.tableController.person"}}
Secondly i wasnt familiar with the usage of the set and get methods in Ember and the difference between extend and create. I wondered before where ember instantiates my object.
So my problem had nothing to do with states it was just a totally misunderstanding of the ember framework. Im a noob thats all.
Ok, this is the first shot of the answer.
I think the main issue is just a typo gotoHome instead of goToHome in the template.
By the way I get rid of some deprecation warnings by using <button {{action }}></button> instead of Ember.Button.
There is some other warnings when I click on the table, because you are referencing some properties which don't exist.
here is the corresponding fiddle: http://jsfiddle.net/Sly7/rKw9A/25/
Since I don't understand how it should work exactly, I'm not sure of the overall behavior. I let you explain me the flow (by editing the question please).
Any other comment is welcome :)