Can someone help explain / provide an example on how to use the LayoutManager within the Backbone Bolierplate?
Within app.js I can see a useLayout function that extends the main app object. Within here it appears to be setting a base layout element:
// Helper for using layouts.
useLayout: function(name, options) {
// Enable variable arity by allowing the first argument to be the options
// object and omitting the name argument.
if (_.isObject(name)) {
options = name;
}
// Ensure options is an object.
options = options || {};
// If a name property was specified use that as the template.
if (_.isString(name)) {
options.template = name;
}
// Create a new Layout with options.
var layout = new Backbone.Layout(_.extend({
el: "#main"
}, options));
// Cache the refererence.
return this.layout = layout;
}
Is that correct? If so, do I somehow the use the 'UseLayout' function with the applications Router? ...to add different UI elements/nested views to the main view?
Thanks.
I will usually have an "app" object that stores all my settings needed throughout the application. This object then extends some useful functions like the one you listed above. For example:
var app = {
// The root path to run the application.
root: "/",
anotherGlobalValue: "something",
apiUrl: "http://some.url"
};
// Mix Backbone.Events, modules, and layout management into the app object.
return _.extend(app, {
// Create a custom object with a nested Views object.
module: function(additionalProps) {
return _.extend({ Views: {} }, additionalProps);
},
// Helper for using layouts.
useLayout: function(options) {
// Create a new Layout with options.
var layout = new Backbone.Layout(_.extend({
el: "#main"
}, options));
return this.layout = layout;
},
// Helper for using form layouts.
anotherUsefulFunction: function(options) {
// Something useful
}
}, Backbone.Events);
});
Now in my router I would do something like:
app.useLayout({ template: "layout/home" })
.setViews({
".promotional-items": new Promotions.Views.PromotionNavigation(),
".featured-container": new Media.Views.FeaturedSlider({
vehicles: app.vehicles,
collection: featuredCollection
})
}).render().then(function() {
//Do something once the layout has rendered.
});
I have just taken a sample from one of my applications, but I am sure you can get the idea. My main layout is basically just a layout template file which holds the elements so the views can be injected into their respective holders.
You would use it as if you're using a regular Backbone View. Instead of building the View directly, you can use this to create a new instance. The code you posted is a wrapper object on top of the Backbone Layout Manager extension with el: #main set as the default View element which is overridable.
var layout = new useLayout({ template: "#viewElement", ... });
Related
So this is my first Backbone project and I'm wondering if I'm doing things in the best way. My app basically has two states, one of them displays a search box and the other displays a search box with a table under it. My router has routes for searching and for the initial landing page with just the search view. When the user types in the query the router navigates to the search route and the table view is added to the page. This is my router:
app.Router = Backbone.Router.extend({
routes: {
'': 'index',
'search/coords=:address&age=:age&rad=:rad': 'search'
},
search: function(address, age, rad){
app.statusView || (app.statusView = new app.StatusView());
app.searchView || (app.searchView = new app.SearchView());
app.trigger('status:loading');
app.Practices.fetch({
reset: false,
success: function() {
app.searchView.setElement($('#search-box')).render();
var searchQuery = new app.SearchQueryModel({age: age, coords: address.split(","), radius: rad});
if (!app.tableView){
app.tableView = new app.TableView({model: searchQuery});
} else {
app.tableView.model = searchQuery;
app.tableView.refresh();
};
}
});
app.trigger('status:clear');
},
index: function() {
app.statusView = new app.StatusView();
app.searchView = new app.SearchView();
app.footerView = new app.FooterView();
app.searchView.setElement($('#search-box')).render();
}
});
As you can see my views are instantiated in the index route and then the same views are used when you search, unless the user is going directly to the search page in which case the views are instantiated there. I'd be surprised if this wasn't very sub-optimal because it seems clumsy to be checking if the view already exists in the search route. Is there a better way of doing things?
Lets say its not bad, but there is one better approach.
As for now you router is in charge of hook-up URL with app astatus and also for view and model control. The second may be detached from Router, so you will need Controller abstraction, but Backbone does not provide Controller "from the box".
But this is not the problem, you can use plugin or take a look at Controller realization in Marionette.js
The main idea here is to split responsibilities between app part correctly:
1) Router - keeps routes and hook up URL with controller action
2) Controller - manage views and models (create, delete, fetch and so on)
3) View - listen to model and DOM events and render data
4) Model - provide actual data and work with data.
First of all welcome to Backbone. It is a lovely framework which can allow you to make things as beautiful or ugly as you'ld like. Your question is about where view instantiation should be, in terms of good practices. Of course it seems sort of wrong to do it there as it violates the Law of Demeter by handling both url routing and view instantiation.
But the views have to be run from somewhere right? If not the router then where?
So I have two responses:
If your app is simple and you just want to play with backbone then you're probably going to be fine. A lot of people let single page app frameworks complicate otherwise simple apps. I'm not trying to be lazy, but where you have it now is the natural beginner's choice in Backbone. If this is your case then stop here.
If you want to use the full power of backbone to custom make a framework then read on.
So my setup is designed to be able to start a new project using some boilerplate functions and create only a few classes which are specific to the new app. Route handling and all of that kind of thing seems low-level enough to me that it should be just part of some configuration that I don't want to look at often. The upshot is that my router looks like this:
define([
'autorouter'
], function(AutoRouter){
var AppRouter = AutoRouter.extend({
autoRoutes: {
":page" : "routeDirect",
":page/:object" : "routeDirect",
":page/:object/:action" : "routeDirect",
"": "routeDirect"
}
});
return AppRouter;
});
Then for each new project I have a file where I keep the non-default routes, for instance:
define(function(require){
return {
"schedule" : require('screens/schedule')
, "logout" : require('screens/logout')
, "login" : require('screens/login')
, "create" : require('screens/create')
, "upload" : require('screens/upload')
, "select" : require('screens/selection')
, "inventory" : require('screens/inventory')
, "describe" : require('screens/description')
}
});
I put each screen into it's own file (using requirejs for the multi-file dependency management). The extra variables get passed through to the screen.
Each screen is the brain for a particular user experience and is responsible for loading views and maybe handling some events while that screen is active.
If that seems like an interesting setup then here is how I did it:
For the router itself I use a boilerplate class which I borrowed from Derick Bailey with some slight modifications:
define([
'jquery', 'underscore', 'backbone'],
function($, _, Backbone) {
var AutoRouter = Backbone.Router.extend({
constructor: function(options){
Backbone.Router.prototype.constructor.call(this, options);
var that = this;
that.app = options.app;
if (this.autoRoutes){
that.processAutoRoutes(options.app, that.autoRoutes);
}
},
processAutoRoutes: function(app, autoRoutes){
var method, methodName;
var route, routesLength;
var routes = [];
var router = this;
for(route in autoRoutes){
routes.unshift([route, autoRoutes[route]]);
}
routesLength = routes.length;
for (var i = 0; i < routesLength; i++){
route = routes[i][0];
methodName = routes[i][1];
method = app[methodName];
router.route(route, methodName, method);
}
}
});
return AutoRouter;
});
I never have to look at it, but I do need to pass it an app instance. For example:
this.appRouter = new AppRouter({app : this});
Finally my route direction function:
define(function(require){
var pathParser = function(path){
return Array.prototype.slice.call(path);
}
var pathApply = function(path, routes, context){
var pathArray = pathParser(path);
var primary = pathArray[0];
if (routes.hasOwnProperty(primary)){
routes[primary].apply(context, pathArray.slice(1));
} else {
routes["default"].apply(context, pathArray.slice(1));
}
}
return function(path){
//NOTE PLEASE that this references AutoRouter
//Which has an app property
var oApp = this.app;
var pathRoutes = _.extend(require('urls'), {
"default" : require('screens/default')
});
pathApply(arguments, pathRoutes, oApp);
};
});
So, did I make things better? Well if you're doing something very simple with just a screen or two, then you certainly don't want to build this sort of setup from scratch. But if you're like me, and you want to be able to quickly produce new projects then having some boilerplate like the two classes above allows for one JSON object to tell the app which routes I should send to which screens. Then I can have all of the logic in the appropriate places, allowing separation of concerns. Which is why I think Backbone is so pleasant.
My understanding of your problem is that you are triggering a route each time you are hitting search.
If this is how you are doing it, then use view events hash (used to capture and handle events that happen in a view) for search.Don't use routes. Define an events hash in the view and have a callback to handle the search.
var myAppEventBus = _.extend({},Backbone.Events);
var myAppController = {
function : search(options) {
// create an instance of the collection and do a fetch call passing the
// search parameters to it.
var searchResultsCollection = new SearchResultsCollection();
// pass search criteria, the success and error callbacks to the fetch
// method.
var that = this;
searchResultsCollection.fetch(
{
data:that.options,
success : function() {
// Pass the fetched collection object in the trigger call so that
// it can be
// received at the event handler call back
var options = {
"searchResultsCollection" : that.searchResultsCollection;
};
myAppEventBus.trigger("search_event_triggered",options);
},
error : function() {
// do the error handling here.
}
}
);
}
};
// Application Router.
var MyAppRouter = Backbone.Router.extend({
routes : {
'search/coords=:address&age=:age&rad=:rad': 'search'
},
search : function(searchParams) {
// Fetch the query parameters and pass it to the view.
var routeSearchExists = false;
var searchOptions = {};
var options = {};
if(searchParams) {
routeSearchExists = true;
// If search params exist split and set them accordingly in
// the searchOptions object.
options.searchOptions = searchOptions;
}
// Create and render the search view. Pass the searchOptions
var searchView = new SearchView(options);
searchView.render();
// Create and render an instance of the search results view.
var searchResultsView = new SearchResultsView();
searchResultsView.render();
// If there are search parameters from the route, then do a search.
if(routeSearchExists) {
searchView.search();
}
}
});
// The main view that contains the search component and a container(eg: div)
// for the search results.
var SearchView = Backbone.View.extend({
el : "#root_container",
searchOptions : null,
initialize : function(options) {
// Intialize data required for rendering the view here.
// When the user searches for data thru routes, it comes down in the
// options hash which can then be passed on to the controller.
if(options.searchOptions) {
this.searchOptions = options.searchOptions;
}
},
events : {
"search #search_lnk":"initSearch"
},
initSearch : function(event) {
event.preventDefault();
var searchOptions = {};
// Fetch the search fields from the form and build the search options.
myAppController.search(searchOptions);
},
search : function() {
if(this.searchOptions) {
myAppController.search(searchOptions);
}
}
});
// The view to display the search results.
var SearchResultsView = Backbone.View.extend({
searchResultsCollection : null;
initialize : function(options) {
// Handling the triggered search event.
myAppEventBus.on("search_event_triggered",this.render,this);
},
render : function(options) {
//search results collection is passed as a property in options object.
if(options.searchResultsCollection)
//Render your view.
else
// Do it the default way of rendering.
}
});
SearchView is the root view that contains the search component and a container like div to hold the search results.
SearchResultsView displays the result of a search.
When search option is clicked, the event callback (initSearch) gets the entered search data.
The search method on myAppController object is invoked and the search query is passed.
An instance of the search collection is created and fetch is invoked passing it the search query and also the success and error callback.
On success, a custom backbone event is triggered along with the fetched collection.
The callback(render method in SearchResultsView) for this event is invoked.
The callback renders the results of the search.
When loading in the router an instance for both the views can be created(the results view will be empty) and attached to the dom.
If you wish to search by multiple query strings at the url then I would suggest you to use the following route.
search?*queryString.
In the route callback make a call to a utility function the splits the querystring and returns you a search object and pass on the search string to the view.
I am using same el for more than 1 view like below. I'm not facing any problem till now. Is this good approach or should i do any changes?
<div id="app">
<div id="app-header"></div>
<div id="app-container"></div>
<div id="app-footer">
</div>
App View:
{
el: "#app",
v1: new View1(),
v2: new View2(),
render: function () {
if (cond1) {
this.v1.render();
} else if (cond2) {
this.v2.render();
}}
}
View 1:
{
el: "#app-container",
render: function (){
this.$el.html(template);
}
}
View 2:
{
el: "#app-container",
render: function (){
this.$el.html(template);
}
}
By reading your question, I do not really see what advantages you could possibly have using this approach rather than having the different div elements being the root el for your views 1, 2, 3 and using
this.$el.html(template)
in the render method.
Your approach could work for a small application, but I think it will become really hard to maintain as the application grows.
EDIT
I still do not really get your point, you could only initialize everything only once in both cases.
Here is a working Fiddle.
By the way I am changing the content by listening to the click event but this is to simplify the example. It should be done by the router.
I do use a mixin to handle such situation, I call it stated view. For a view with all other options I will send a parameter called 'state', render will in-turn call renderState first time and there after every time I set a 'state' renderState will update the view state. Here is my mixin code looks like.
var setupStateEvents = function (context) {
var stateConfigs = context.getOption('states');
if (!stateConfigs) {
return;
}
var state;
var statedView;
var cleanUpState = function () {
if (statedView) {
statedView.remove();
}
};
var renderState = function (StateView) {
statedView = util.createView({
View: StateView,
model: context.model,
parentEl: context.$('.state-view'),
parentView:context
});
};
context.setState = function (toState) {
if (typeof toState === 'string') {
if (state === toState) {
return;
}
state = toState;
var StateView = stateConfigs[toState];
if (StateView) {
cleanUpState();
renderState(StateView);
} else {
throw new Error('Invalid State');
}
} else {
throw new Error('state should be a string');
}
};
context.getState = function () {
return state;
};
context.removeReferences(function(){
stateConfigs = null;
state=null;
statedView=null;
context=null;
})
};
full code can be seen here
https://github.com/ravihamsa/baseapp/blob/master/js/base/view.js
hope this helps
Backbone Rule:
When you create an instance of a view, it'll bind all events to el if
it was assigned, else view creates and assigns an empty div as el for that view and bind
all events to that view.
In my case, if i assign #app-container to view 1 and view 2 as el and when i initialize both views like below in App View, all events bind to the same container (i.e #app-container)
this.v1 = new App.View1();
this.v2 = new App.View2();
Will it lead to any memory leaks / Zombies?
No way. No way. Because ultimately you are having only one instance for each view. So this won't cause any memory leaks.
Where does it become problematic?
When your app grows, it is very common to use same id for a tag in both views. For example, you may have button with an id btn-save in both view's template. So when you bind btn-save in both views and when you click button in any one the view, it will trigger both views save method.
See this jsFiddle. This'll explain this case.
Can i use same el for both view?
It is up to you. If you avoid binding events based on same id or class name in both views, you won't have any problem. But you can avoid using same id but it's so complex to avoid same class names in both views.
So for me, it looks #Daniel Perez answer is more promising. So i'm going to use his approach.
I am trying to either override or extend an existing component - the Rally.ui.PercentDone component. I want to provide it with a portfolio item with all the data necessary to render it using the same color coding Rally native apps use (the Rally Health Color Calculator).
I really just need the function to pass the correct record. Here is my idea so far:
Ext.define('Custom.PercentDone', {
requires: ['Rally.ui.renderer.template.progressbar.PortfolioItemPercentDoneTemplate', 'Rally.util.HealthColorCalculator'],
extend : 'Rally.ui.PercentDone',
alias : 'widget.cpercentdone',
config: {
record: null
},
constructor: function(config) {
config = this.config;
this.renderTpl = Ext.create('Custom.renderer.template.progressbar.PercentDoneTemplate', {
calculateColorFn: Ext.bind(function(recordData) {
console.log('called my custom coloring fn');
var colorObject = Rally.util.HealthColorCalculator.calculateHealthColorForPortfolioItemData(config.record, config.percentDoneName);
return colorObject.hex;
}, this)
});
this.renderData = config;
this.mergeConfig(config);
this.callParent([this.config]);
}
});
var custom = Ext.create('Custom.PercentDone', {
record: item,
percentDoneName: 'PercentDoneByStoryPlanEstimate',
});
but my calculate color function is not being called instead of the default.
I got it to work by overriding:
var percentDoneByStoryCountEl = Ext.create("Rally.ui.PercentDone", {
record: item,
percentDoneName: "PercentDoneByStoryCount",
percentDone: item.PercentDoneByStoryCount
});
tpl = percentDoneByStoryCountEl.renderTpl;
tpl.calculateColorFn = function (recordData) {
var colorObject = Rally.util.HealthColorCalculator.calculateHealthColorForPortfolioItemData(item, "PercentDoneByStoryCount");
return colorObject.hex;
};
Ext.override(percentDoneByStoryCountEl, {
renderTpl: tpl
});
but I would like to figure out how to do it via extending the component instead.
Thanks for your help.
In my Application, I have the following JSON data format:
{
Item: {
property1: '',
...
}
}
Following the solution of this stackoverflow.com answer, I modeled my Backbond.js models the following way:
App.Models.Item = Backbone.Model.extend({
});
App.Models.ItemData = Backbone.Model.extend({
defaults: {
'Item': new App.Models.Item
}
});
I now want to bootstap the data to my App from the Backend system on the page load the following way:
var item = App.Models.ItemData({
{Item:
{property1: 'data'}
}
});
The problem I have now is that item.get('Item') returns a plain JavaScrip object and not a Backbone.Model object, because the defaults are overwritten. How can I create the Backbone.js object while ensuring that item.get('Item') is an App.Models.Item object?
I also have read that if you nest Backbone.Models, you should wirite custom getter methods, so the rest of your app dose not have to know about the internal data structure. If so, what is the right way to implement those setters and getters?
You can override the parse method on your ItemData model. No defaults required. The parse method will initialize an empty model, if one is not passed:
App.Models.ItemData = Backbone.Model.extend({
parse: function(attrs) {
attrs = attrs || {};
if(!(attrs.Item instanceof App.Models.Item))
attrs.Item = new App.Models.Item(attrs.Item);
return attrs;
}
});
And then initialize your ItemData model with the option parse:true:
var item = new App.Models.ItemData({Item:{property1: 'data'}}, {parse:true});
I am working in a single page app that has the following layout:
I am using a Backbone.js router to manage the elements that load on the screen:
var AppRouter = Backbone.Router.extend({
routes: {
"" : "list",
"content1" : "content1",
"content1/cont3": "cont3"
},
list: function() {
var list = new List().render().$el; //view
$("#List").html(list);
},
content1: function(){
var cont1 = new Content1().render().$el; //view
$("#Content1").html(cont1);
},
content3: function(){
var cont3 = new Content3().render().$el; //view
$("#Cont3").html(cont3);
}
});
Everytime I click on a list item in #List, #Content1 gets generated, and when I do it on the blocks on #Content1, #Cont3 appears.
The problem I am facing is that if, for some reason, I refresh the page when the adress is localhost/content1, for example; the elements in #List disappear.
I want the content in #List to be always present when loaded, independent on what the url may be, as well as the content in #Content1. Is there a way to achieve this using backbone routers?
Thanks
You don't need to match 1 route <-> 1 View.
I would change the routes to something like this:
"list": "displayContent",
"list/:c1": "displayContent",
"list/:c1/:c3": "displayContent",
So it's only one callback the one who organize what Views are rendered or what not.
displayContent: function(c1,c3) {
Store the content1 variable, and check if has been rendered already or not, etc.
Have a look to this question: How to handle initializing and rendering subviews in Backbone.js?
Or for more complex apps, maybe a layout framework in top of Backbone could help, although I would recommend do your own stuff until you understand how Backbone works.
https://github.com/tbranyen/backbone.layoutmanager
https://github.com/derickbailey/backbone.marionette
I think you can try this:
.....
list: function() {
var list = new List().render().$el; //view
$("#List").html(list);
},
content1: function(){
var cont1 = new Content1().render().$el; //view
$("#Content1").html(cont1);
//Pseudo code
if (listisempty){
list();//If the list is empty, then the initialization list.
};
},
.....