JST with Backbone and Underscore - backbone.js

I am using Backbone and Underscore to create a small test site.
I am compiling all my html template files into one JST javascript file as suggested here and here.
It isn't however very obvious how to use this with template files. I have tried this:
App.HeaderView = Backbone.View.extend({
el: '#headerContent',
template: JST['header.html'](),
//template: window["JST"]["header.html"],
//template: _.template("<h1>Some text</h1>"),
initialize: function () {
this.render();
},
render: function() {
//var html = this.template();
//// Append the result to the view's element.
//$(this.el).append(html);
this.$el.html(this.template());
return this; // enable chained calls
}
});
The error I get is JST.header.html is not a function.
(The final commented out bit works by the way template: _.template("<h1>Some text</h1>") so I know the problem isn't with anything else).
It might be because I am using browserify (so have tried 'requiring' the file), but I have tried several different ways of 'including' the template file, including adding it directly:
<script src="templates/_templates.js"></script>
<script src="js/functions.js"></script>
</body>
</html>
Any ideas what needs to be done to get this to work?

On line 3 you don't want to invoke the template, rather just use:
template: JST['header.html'].
Currently you're setting template to equal the return value of the function and then trying to invoke that return value instead of the actual function, so it is raising a "is not a function" error.

Related

Uncaught Error: Cannot read property 'replace' of undefined - Backbone.js [duplicate]

I 'm trying to develop a simple RSS app using backbone.js. I 'm using this backbone.js tutorial. I 'm getting the following error, on line 2(template), when defining the template.
Can someone also tell me why is tagName: "li" defined in the tutorial?
uncaught TypeError: Cannot call method 'replace' of undefined
backbone.js
Javscript
window.SourceListView = Backbone.View.extend({
tagName:"li",
template: _.template($('#tmpl_sourcelist').html()),
initialize:function () {
this.model.bind("change", this.render, this);
this.model.bind("destroy", this.close, this);
},
render:function (eventName) {
$(this.$el).html(this.template(this.model.toJSON()));
return this;
},
close:function () {
$(this.el).unbind();
$(this.el).remove();
}
});
HTML
<script type="text/template" id="tmpl_sourcelist">
<div id="source">
<a href='#Source/<%=id%>'<%=name%></a>
</div>
</script>
thanks
You're getting your error right here:
template: _.template($('#tmpl_sourcelist').html()),
Part of _.template's internals involves calling String#replace on the uncompiled template text on the way to producing the compiled template function. That particular error usually means that you're effectively saying this:
_.template(undefined)
That can happen if there is no #tmpl_sourcelist in the DOM when you say $('#tmpl_sourcelist').html().
There are a few simple solutions:
Adjust your <script> order so that your #tmpl_sourcelist comes before you try to load your view.
Create the compiled template function in your view's initialize instead of in the view's "class" definition:
window.SourceListView = Backbone.View.extend({
tagName:"li",
initialize:function () {
this.template = _.template($('#tmpl_sourcelist').html());
//...
As far as tagName goes, the fine manual has this to say:
el view.el
[...] this.el is created from the view's tagName, className, id and attributes properties, if specified. If not, el is an empty div.
So having this in your view:
tagName: 'li'
means that Backbone will automatically create a new <li> element as your view's el.

Backbonejs with mustache template.

I want to do a simple application using backbonejs with mustache template. Can you give me a sample program??
New node file:
var Person = Backbone.Model.extend({
defaults: {
name: 'Guest Worker',
}
});
var PersonView = Backbone.View.extend({
tagName: 'li',
initialize: function(){
_.templateSettings = {
interpolate: /\{\{(.+?)\}\}/g
};
this.render();
},
render: function(){
var template1 = _.template("Hello {{ name }}!");
this.$el.html( this.template1(this.model.toJSON()));
}
});
This is my js code.
Mustache template engine doesn't work this way. Here's a small example from the documentation :
var view = {
title: "Joe",
calc: function () {
return 2 + 4;
}
};
// output will then contain processed html
var output = Mustache.render("{{title}} spends {{calc}}", view);
Anyway, i would recommend you using Handlebars (http://handlebarsjs.com/) instead of Mustache. It's almost the same syntax (and it has partials as Mustache does), but far more powerful thanks to its helpers.
Finally, you should use something to precompile your templates. You can either use handlebars's one (http://handlebarsjs.com/precompilation.html) or another one like Brunch, or Grunt.
[Edit] OK, let's try to elaborate a bit... I won't give you any complete example (i don't have one right now, and it wouldn't teach you anything), but the one i posted above should be sufficient to understand Mustache basics.
Now you have to find a way to precompile your templates, here's an answer with some clues : How to load templates with Hogan.JS from an external file?
While an underscore template is set like this in Backbone.js:
template: _.template(...)
A mustache template is set like this:
template: Mustache.render.bind(null,<template>)
//Mustache.render(template,view,[partials])
//a partial function is created because this.template should be a function
//<function>.bind() creates the partial function
don't do these:
template: Mustache.to_html(<template>) // deprecated
// or
template: Mustache.to_html.bind(null,<template>) // deprecated
// Use Mustache.render() and not Mustache.to_html()

Backbone Underscore Template

So I'm checking out the changes related to the latest backbone/underscore version. Prior I have a project running with BB 0.5.2 and underscore 1.1.7. I'm noticing something strange with regards to defining a template property within a view in the new version, which gives me reservations in going forward with upgrading.
In my current version I would define a view as such:
var MyView = Backbone.View.extend({
template: _.template($('#exampleTemplate').html()),
initialize: function() {...},
render: function() { $(this.el).html(this.template(someObjectParam)); },
});
However, if I attempt to work in the same manner, using a simplified todo clone attempt as an example, I setup an html with an inline script template as such:
<script>
$(document).ready(function() {
app.init();
});
</script>
<script type="text/template" id="itemViewTemplate">
<div class="item">
<input type="checkbox" name="isComplete" value="<%= item.value %>"/>
<span class="description"><%= item.description %></span>
</div>
</script>
In my included JS file I have:
var ItemView = Backbone.View.extend({
el: 'body',
// Below causes error in underscore template, as the jquery object .html() call
// returns null. Commenting will allow script to work as expected.
templateProp: _.template($('#itemViewTemplate').html()),
initialize: function() {
// Same call to retrieve template html, returns expected template content.
console.log($('#itemViewTemplate').html());
// Defining view template property inside here and calling it,
// properly renders.
this.template = _.template($('#itemViewTemplate').html());
this.$el.html(this.template({item: {value: 1, description: 'Something'}}));
},
});
var app = {
init: function() {
console.log('Fire up the app');
var itemView = new ItemView();
}
}
So I'm left confused as to why defining the template property directly causes the call to retrieve the template html to return a null value, thus breaking the attempt to define an underscore template object (mouthful). However, if the definition is done within the initialize function, the call to retrieve the template html properly finds the template so its contents can be passed to the underscore template. Anyone see what I'm potentially missing?
Thanks in advance!
If this:
var ItemView = Backbone.View.extend({
//...
templateProp: _.template($('#itemViewTemplate').html()),
//...
});
is failing because $('#itemViewTemplate').html() is null, then you have a simple timing problem: you're trying to read the content of #itemViewTemplate before it exists. Your old version should suffer from exactly the same problem.
Either make sure everything is loaded in the right order (i.e. your views after your template <script>s) or compile the template in your view's initialize. You can check for the templateProp in your view's prototype and only compile it on first use if you want:
initialize: function() {
if(!this.constructor.prototype.template)
this.constructor.prototype.template = _.template($('#itemViewTemplate').html());
//...
}
Demo: http://jsfiddle.net/ambiguous/HmP8U/

underscore template is removed from the DOM so can't be re-used

I'm trying to use a simple inline underscore.js template with backbone, and pulling the template from a <script> tag via jQuery's html() method.
The page is supposed to render multiple Recipe callouts for each returned by the Recipe Model. It works on the first thumbnail, but on the second, it seems the <script> tag has been removed from the DOM, so underscore fails to render it and bails with str is null on line 913
For the template, I have
<script type="text/html" id="user-recipe-rated-template">
<div class="user-recipe-rated">
<a class="thumb" href="<%= href %>"></a>
<p><%= title %></p>
</div>
</script>
And the backbone view looks like:
var UserRecipeView = Backbone.View.extend({
initialize : function() {
this.template = _.template($("#user-recipe-rated-template").html());
},
render : function()
{
this.el = this.template({
title: this.model.get("Title"),
href: '#'+this.model.get('UserContentId'),
image_src: this.model.get('ThumbnailSrc')
});
return this;
}
});
So, what I am seeing is that $("#user-recipe-rated-template") exists on the first thumbnail and all is well. On the second, it returns an empty array and underscore can't proceed.
I've trying memoizing the string of html and such, and that might work, but it seems there should be a cleaner way of doing this. What am I doing wrong?
(I'd like to use templates inlined as opposed to external JST for now to keep things simple - it seems nicer to have the template embedded in the page near where it will be loaded when the data comes in)

Using Handlebars with Backbone

I am learning Backbone/Handlebars/Require. I have looked all over online and on SO - are there any tutorials or websites that you can direct me to that would provide helpful information for using using handlebars instead of underscore?
Using handlebars.js instead of underscore templating is pretty straightforward. Check out this example:
https://cdnjs.com/libraries/backbone.js/tutorials/what-is-a-view
(scroll to the "Loading a Template" section)
SearchView = Backbone.View.extend({
initialize: function(){
this.render();
},
render: function(){
// Compile the template using underscore
var template = _.template( $("#search_template").html(), {} );
// Load the compiled HTML into the Backbone "el"
this.el.html( template );
}
});
Basically, the convention in backbone is to build your html in a render function. The use of templating engine is left completely up to you (which I like about Backbone). So you'd just change it to:
SearchView = Backbone.View.extend({
initialize: function(){
this.render();
},
render: function(){
// Compile the template using Handlebars
var template = Handlebars.compile( $("#search_template").html() );
// Load the compiled HTML into the Backbone "el"
this.el.html( template );
}
});
Since you're using require.js, you can make Handlebars a dependency at the top of your module. I'm pretty new to this, but it sounds like the learning to focus on would be Backbone.js patterns and require.js usage.
I would prefer to compile the template once (during initialize), that way you avoid to recompile the template with every render. Also, you need to pass the model to the compilated template in order to generate the HTML:
SearchView = Backbone.View.extend({
initialize: function(){
// Compile the template just once
this.template = Handlebars.compile($("#search_template").html());
this.render();
},
render: function(){
// Render the HTML from the template
this.$el.html(this.template(this.model.toJSON()));
return this;
}
});
If you are using require.js you wont be able to use the current Handlebars file. I used the following Handlebars Plugin and it seems to be kept up to date with the current version. Just replace your Handlebars file with the plugin above if Handlebars is returning null in your module.
define(["app", "handlebars",
"text!apps/templates/menu.tpl"
], function (app, Handlebars, template) {
return {
index: Marionette.ItemView.extend({
template: Handlebars.compile(template),
events: {
'click .admin-menu-ref': 'goToMenuItem'
},
goToMenuItem: function (e) {
//......
}
})
}
});
new view.index({model: models});

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