I'm currently trying Backbone.js along with a rails app. My problem is, that I don't know how to implement the Backbone controllers and views with my rails app. I've read a lot of tutorials, but they are always using just one controller in backbone.js.
For example, I have two controllers in rails.
Activities Controller
Includes two views, a google map and a search field. The google map is inserted with a backbone view, the searchfield is in HTML and gets its functionality through a backbone view.
The search field should fetch data from my rails model and display markers inside the map.
And the other one is
Users Controller
Here the users profile is viewed, and I want to add some ajax functionality like updating values and other things
In my application.js I start the app using
var App = {
Views: {},
Controllers: {},
Collections: {},
init: function() {
new App.Controllers.Activities();
new App.Controllers.Users();
Backbone.history.start();
}
};
$(function() {
App.init();
});
The problem is, that I don't need the Activities controller in my User Profile and the Users controller in the Rails Activities controller. How could I solve this? Should I try reading the current URL within javascript and then decide which controller is used?
Or should I put the JavaScript file into the application.html.erb and then decide here which controller should be used?
Or is this the wrong way to use backbone.js controllers?
Am I getting sth wrong with the structure of backbone.js? Or am I using the Controllers in a wrong way?
Another question is, how to add little JavaScript, in particular jQuery, functionality through Backbone.js? For example, I want to remove the label inside a field, when the user clicks into the field. Or I want to do some tab-functionality and just toggle the visibility of some elements.
Should I create for each element that is using javascript a Backbone view? Or is this overload?
Hope I made myself clear and anybody can help,
thx!
Why not make use of the routes feature Backbone provides to decide which method to call? The activities controller would contain only routes use for activities, the user controller only for the user handling, and so forth.
Like this you can instantiate the controller just as you do and the routing will decide what happens based on the current location's hash.
If you can't use links with hashes (or there are no such links on your page), I'd simply name my view containers specific enough to attach events only for the current view when needed.
jQuery plugins etc. belong into views IMO. Same goes for your tabs and input hint toggle.
Update
On a general level (and I would not necessarily recommend doing it this way): If you have two methods:
// should be only called for the 'Foo' controller
function foo() {
alert("FOO");
};
// should be only called for the 'Bar' controller
function bar() {
alert("BAR");
};
and want to call only one of them depending on the current Rails controller, create a small helper:
e.g. in you *helpers/application_helper.rb*
def body_class
controller.controller_name
end
then call this method in your layout file (or header partial):
<body class="<%= body_class %>">
…
and use e.g. jQuery to "split" your JS execution:
if ($('body').hasClass('foo')) {
foo();
} else if ($('body').hasClass('bar')) {
bar();
}
I personally use jammit (from the same author of backbone). You can group stylesheets and javascripts files by module and use them on your different pages. So you create a module for your activities view and another for your user view each requiring the necessary JavaScript file. Two nice things about this:
you have only code used on the page loaded on the page
jammit comprsses everything for you
This is the way to go when not creating a single page web app where you relies on # routes to navigate from one controller to another. In your case you have multiple single page apps inside a main rails app.
Im a Backbone.js newb, so please someone correct me if Im wrong, but I think youre confusing what Backbone controllers are used for.
Backbone.js controllers basically consists of hashbang routes(similar to Rails routes) and actions that these routes call. For instance if you have a rails route that will render a view at http://mysite.com/backbone_test and you have a following backbone route:
var MyController = Backbone.Controller.extend({
routes: {
"foo/:bar": "myFirstFunction"
},
myFirstFunction: function(bar){
console.log(bar);
});
then if you go to http://mysite.com/backbone_test#foo/THIS-IS-AMAZING then MyController.MyFirstFunction gets executed and "THIS-IS-AMAZING" gets logged in JS console.
Unless you have a direct need for this sort of hashbang-related functionality, such as saving a state of your JavaScript application via an url (for example: http://my.app.com/#key=value&key=value&ad-infinitum=true ) Id advise against using Backbone controllers. You can get all of the functionality u described via Models Collections and Views.
Nice thing about Controllers and Backbone in general is that its modular and different parts can be used independently.
I guess the summary of this answer is that if you dont have a single page javascript application, do not use Backbone Controllers, rely on your rails controllers instead.
Related
Being relatively new to MVC I have been struggling for the past several weeks getting my layout to work.
I have managed to get myself really twisted into knots. So instead of trying to explain and unravel my mess perhaps instead someone could explain how I would accomplish the following at a high level.
_Layout this would have all the css js etc. It would also have basic structure.
Of course HTML tags not allowed in code block....each render is in a div.
#RenderPartial(Header)</div>
#RenderBody()</div>
#RenderPartial(Footer)</div>
RenderBody is Index.cshtml and it would be broken into three pieces
#
#Html.Partial(NavMenu, model)</div>
#Html.Partial(SubNavMenu, model)</div>
#Html.Partial(MainContent, model)</div>
I have this basic layout and it looks fine until you click one of the menu items.
The menu items render as:
<a class="k-link" href="/stuffroute">Stuff</a>
That route goes to a controller that returns a view and that navigates away from the above arrangement in Index.cshtml. So I end up with the header, footer, and subdash nav....
So the question is...
How do I route / orchestrate my layout to not lose the differing pieces?
Partials don't do anything for you here. You're essentially asking about how to create SPA (single page application), although in this case your application will have other pages, it's just that the index view will act like a SPA.
That requires JavaScript, specifically AJAX, to make requests to endpoints that will return HTML fragments you can use to replace portions of the DOM with. For example, clicking "Stuff 1" causes an AJAX request to be made to the URL that routes to FooController.GetSubNav([stuff identifier]). That action then would use what was passed to it to retrieve the correct sub-nav and return a partial view that renders that sub-nav. Your AJAX callback will then take this response, select a portion of the DOM (specifically the parent of the sub-nav) and insert the new HTML as its innerHTML.
If you're going to be doing a lot of this, you'll want to make use of some client-side MVC-style JavaScript library, like Angular for example. These make it trivial to wire everything up.
Let's say that I have a blog where each post can have several sections and comments and I'd like to use a hard-links to navigate and operate on this. There are several samples using some pseudo-code, of course they doesn't work, just demonstring my intends :)
Of course /blog.html#/posts/1 uses PostRoute, PostController etc and uses :post_id for finding object - that's obvoius.
How can I pass (and then access) additional params which doesn't change the controller but I can use them to navigation. ie /blog.html#/posts/1?section=123 should use the same route, controller and view as it was just Post, but I'd like to read the section and just navigate to section with #123
/blog.html#/posts/1/?comments=456 - actually should behave like section from point 1, but navigates to comment and optionally add some class to the container.
Other case: I'd like to go to section 123 AND additionally edit it with link like: /blog.html#/posts/1?section=123&action=edit. Now I'm using a button with an action like {{action editSection section}} and {{#if isEdit}} but I'd like to be able to reflect this in URL and also go to this state from URL (de facto my post can have several different modes not only preview/edit, therefore it should be accesible by the link).
I hope that cases makes sense, TBH I have no idea in which direction should I go. Tried with nested routes, but I'd like to avoid changing the controller. Also have no concept how to reflect the action in the URL...
I'm using Ember 1.1.2
You can use the model method of the route to handle such parameters, separate them from the model parameter and set the appropriate controller state.
Another approach would be to use nested routes that will render un-nested views(and controllers) - as explained towards the bottom here.
I think I'm trying to use Backbone in an unintended way, and I couldn't really find much on it. Basically I have a Rails app that is serving up the views. I want to keep the regular navigation (as in page reloading), but let backbone see the route and setup certain parts of the templates on that page, handle the models, and all of that good stuff. So basically I'm using Backbone to handle all of my complicated javascript without making it a "single page app". Would enabling PushState break my absolute paths in older browsers? eg: "http://localhost:3000/projects" matching the route "projects".
PushState will not work in old browsers like IE6, but you could use different technique, for example you could use jQuery selectors and check whether you're on the particular page:
if ($('#login-page').length > 0) {
// we're on the login page
// ..initialize login page related backbone collections and views
}
..or you could store action/controller name somewhere in the html using data attribute: <body data-action="edit" data-controller="post"> and check it in javascript va4 $body = $('body'); if ($body.data('action') == 'edit' && $body.data('controller') == 'posts') {} etc.
..or you could have separate js file for each action/controller pair and include it on demand.
I suppose it should do justice to state what I think I know so far as well as what I've done:
1) I created the app and did my first db migration; I now have my dev, test and production databases. The dev db has a table called 'wines'.
2) I made a scaffold which created the necessary files.
3) The basic index/update/destroy methods are set up and I can browse the pages.
4) From what I gather, the ActiveRecord class "Wine" automatically inherits properties from the database? Each column is a property and each row in the table 'wines' is a potentially instantiated object which is called from the wine_controller script.
The problem I'm having now is that I want to create a common layout that all controllers use. The only things that will change will be the page title, potentially some <link> tags in the header, the <body> attributes (javascript onload events most likely) and whatever lies inside the <body> tag.
I find myself looking up functions that will do what I want (like "favicon_link_tag", "stylesheet_link_tag" and "auto_discovery_link_tag"...) but I can't find the right place to PUT them! I know this has something to do with my lack of understanding of how things are executed/inherited. For example if I were to declare #pageTitle in application_controller.rb and use #pageTitle in ApplicationHelper it won't work. Or even using "stylesheet_link_tag" in application_controller.rb throws an error. I'm just not getting something.
How does each thing relate to another in terms of chronological execution, scope, etc.?
In your "app/views" directory there is a folder called "layouts." By default there should be an "application.html.erb" file in there, but if there isn't you can create it.
Your "application" layout file is the default layout file used by any view. However, if you want a particular controller to use a different view, you can override this. See this railscast, and this one is helpful too.
The main thing to understand is the content from any particular view will show up wherever the yield method appears in your application layout. The main 'yield' block gets the view file specified by your controller action, but you can mark anything inside any view to be passed to another yield block instead. For instance, the "title" example you gave could be passed to the head of your application layout. See this railscast for a detailed example of that.
For more, you should read the Rails Guide, and you might want to consider picking up a Rails starter book.
I got my feet wet with "Beginning Rails 3," which was a phenomenal introduction to the framework. A couple days with that book and it was all making sense to me, and I was developing faster than I ever had before. Rails rocks once you get to know it, but it's definitely worth going through a book.
Please continue to ask questions, I'll help if I can :)
-EDIT- To answer your question about control flow, it basically works like this:
Your browser sends a GET request for a particular URL.
The router takes that request, matches it to a controller action, triggers that controller action, and provides the controller any parameters associated with the request. For instance: if you requested example.com/posts/123?color=red this would trigger the SHOW action of your posts_controller, and would pass {:color => 'red'} to the params hash. You would access that using params[:color]
The controller action does its thing, and when it's done it renders output. By default it renders whatever view is located in app/<controller_name>/<action_name>, and will whichever file matches the extension appropriate to the request (ie an AJAX request would trigger <action_name>.js.erb and a GET request would trigger <action_name>.html.erb.
You can override this using the render method, for example by passing render 'foo/bar' to render using the view for FooController, Bar action instead of your current action.
Note that no matter what you render, the data available to the view is whatever is in the specific controller action the router triggered, not the controller action that would 'normally' render that view.
The view file is parsed using the data from the controller that called it. If you have any content_for methods then the view code that is inside the content_for block will go where you tell it, otherwise everything else will go to the main YIELD block in your application layout (or whatever layout your controller specified instead).
The application layout is parsed, and the content from the view is inserted into the appropriate areas.
The page is served to the user.
That's a simplification in some ways, but I think it answers your question. Again, feel free to keep asking :)
In a view I am generating an HTML canvas of figures based on model data in an app. In the view I am preloading JSON model data in the page like this (to avoid an initial request back):
<script type="text/javascript" charset="utf-8">
<% ActiveRecord::Base.include_root_in_json = false -%>
var objects = <%= #objects.to_json(:include => :other_objects) %>;
...
Based on mouse (or touch) interaction I want to redirect to other parts of my app that are controller specific (such as view, edit, delete, etc.).
Rather than hard code the URLs in my JavaScript I want to generate them from Rails (which means it always adapts the latest routes).
It seems like I have one of three options:
Add an empty attr to the model that the controller fills in with the appropriate URL (we don't want to use routes in the model) before the JSON is generated
Generate custom JSON where I add the different URLs manually
Generate the URL as a template from Rails and replace the IDs in JavaScript as appropriate
I am starting to lean towards #1 for ease of implementation and maintainability.
Are there any other options that I am missing? Is #1 not the best?
Thanks!
Chris
I wrote a bit about this on my blog: Rails Dilemma: HATEOAS in XML/JSON Responses.
I came to similar conclusions. There's no incredibly clean way to do it as far as I know, because by default the model is responsible for creating a JSON representation of itself, but generating URLs is strictly a controller/view responsibility.
Feel free to look over my thoughts/conclusions and add comments here or there.