I'm using underscore template engine for an backbone application. As of now I have over 15 templates in the <head>. Its getting hard to maintain. So far, most of the solutions I seen to manage templates ended up needing them to be js files. That's also a headache, I prefer them to be html files for editing purposes.
I took a look at requirejs and not sure if I need that since it kinda revolves around a more modular approach that I can't say I'm using at the moment (although I will soon).
What will be the best way to manage templates and load/cache them as needed?
Personally we needed a robust solution at my company, so we went with:
Require.js - for module loading
Handlebars - for more powerful templating than Underscore can offer
HBS - an excellent require plug-in from Alex Sexton that handles bringing compiled templates in via Require
With this setup I can keep all of my templates in their own file, and then to use them I have files like this:
define(['template!path/to/someTemplate'], function(someTemplate) {
var MyNewView = BaseView.extend({template: someTemplate});
$('body').append(new MyNewView().render().el);
}
(and as you might guess we have a base Backbone view called BaseView which uses the view's template property to render the view).
Now, all that being said, if you don't need such a robust setup then Require may not be for you. In that case I would do the following:
Put all of your templates in to one or more HTML files; wrap them in script tags, like so:
<script id="dummyTemplate" type='text/template'>
<span>I'm a template!</span>
</script>
Write some code on your server-side to include those HTML files in the main HTML file you send to the client
Write a function which takes a template ID, gets the text of that element, compiles it in to a template, and returns that template (maybe cache the compiled templates if you want ... of course, with Underscore templates I don't think you even need compiling, so you can skip all that).
Use your function to access your templates: $("#something").html(templateFunc('dummyTemplate').template())
This will allow you to store your templates in html files (for syntax coloring), but still access them conveniently in JS. You can also divide your templates between as many files as you want, as long as you can write include logic to bring them in.
If you do opt for Require though, definitely check out the HBS plugin. And if you haven't looked at Handlebars templates yet, you might want to; they're far more powerful than Underscore ones (but like any good templating system, don't allow for too much logic).
Not sure what you mean by it being unmaintainable. Is it just a long list?
You don't need to keep your templates in the head. They can be at the bottom of your body as well. They just need to be defined before you try to use them.
One thing you might look into, depending on the server technology you are using would be to separate your templates into a different HTML file and include it at runtime.
Related
I'm starting in javascript development, and did a simple project with node.js as a rest API and a client using backbone, everything look perfectly till I want to get my templates out of my js.
I found different approaches, some of them with some time (like one year old) but I can't understand which one could be better:
A .js file with a var with the html code
pros -> easy to load, easy to pass to underscore to compile it.
cons -> scape every single line.
app.templates.view = " \
<h3>something code</h3> \
";
load template:
template: _.template(app.templates.view)
External template in Underscore
Use require.js to load with text plug-in.
pros -> load different templates as needed.
cons -> I don't like the approach to put everything inside a "loader" function...
define(["TemplateEngine", "text!templates/template.html"], function(...
RequireJS: Loading modules including templates and CSS
A function that loads the templates with an AJAX petition.
pros -> You can load the template that you need and adds local storage posibilities.
cons -> Seems that I have to merge all my templates into one file for production environments.
function() {
var templateLoader = {... $.get calls ...}
Best way to asynchronously load underscore templates
And a Jquery plug-in for template loading that I really liked but it seems that it didn't go to release?
http://api.jquery.com/jQuery.template/
It seems that require is the best approach, but maybe I'm missing something, I do wan't to make things as clean as possible since I'm in the learning/having fun phase :D
Any good article or github project with a good structure or any light on this will be appreciated.
Thanks.
Excuse any major spelling mistake, not an English speaker :)
--EDIT--
found some interesting videos to understand how to start and wrap things with require.js
http://www.youtube.com/watch?v=VGlDR1QiV3A
http://www.youtube.com/watch?v=M-wjQjsryMY
I would recommend using require.js with text plugin. Mixing html templates as strings in javascript variable is bad idea, as well as using something like <script type="text/template"></script>.
Here is one very good series on backbone.js which covers template loading and project build as well: http://dailyjs.com/2012/11/29/backbone-tutorial-1/. Github project is also provided there.
Require is a good option from the ones you listed.
Is there a reason you haven't considered simply:
Storing templates in the pages that use them as <script type='text/template'> nodes?
Storing templates as text (non-JS) files and loading them via XHR on pages that use them?
I'm using require.js and text.js to load a template file that has a bunch of <script> templates in it:
e.g. /scripts/templates/comments.html
<script type="text/template" id="js-comment-reply-tmpl">
// html in here
</script>
<script type="text/template" id="js-comment-edit-tmpl">
// html in here
</script>
And because using underscore's template system (or any similar js micro-templating system), this file itself gets loaded as a string. Is there a smart way to just grab each template from within that file? e.g. $(template).html() wrap it in jQuery and then do a find() or something on it? I'd essentially have to place it into the DOM first though, so that would probably be slow as hell and I might as well just not even load it with text.js and just pluck it out of the DOM initially.
My other thought is to split them each into their own files, but then that would slow down on request time (although I'd probably just end up using r.js with node to minify this all in the end anyway so it wouldn't matter).
e.g. /scripts/templates/comment_reply.html
<script type="text/template" id="js-comment-reply-tmpl">
// html in here
</script>
e.g. /scripts/templates/comment_edit.html
// html in here
What's the best/most efficient way to do this?
I would advise moving each template into it's own file and loading them all separately. Some of the advantages of doing so are:
Easier maintainance - Searching for a template in a project is easier if they all have their own names and it also reduces hassle with source control conflicts if developers aren't all editing the same file.
Portability - If you end up using a templating system that can be used on the server (like Mustache) then the templates are already easy to share between front and back-end.
The main disadvantage that you already highlighted are the extra requests, but you should definitely not be going to production without building your scripts with r.js so this shouldn't be a problem
I was trying to convince a fellow co-worker into using Mustache/Hogan in the front-end of a project and I proposed the following:
Having a templates.js file, which could roughly look like this:
var tpl_alert = '<div class="alert">{{msg}}</div>';
var tpl_welcome = '<p class="user-{{type}}">Welcome, {{name}}</p>';
...
Then, we would include templates.js and use the corresponding tpl in the Mustache/Hogan.js rendering.
My proposal was turned down, since we're hardcoding html templates into js variables.
Is this really that bad? Which are other alternatives to this?
To answer your question, putting your templates in javascript variables inside a static JavaScript file makes it difficult to maintain your templates. You need to worry about string escaping whenever you want to make a simple change. And 1 syntax error will crash your app.
However, putting all your templates in a single JavaScript file is the fastest way to load your templates.
Your alternatives are:
Storing your templates in seperate files and generating the static template.js file as a prebuild step.
Loading your html template files async through AJAX into javascript variables.
Using a library like Require.js that will load your templates asynchronously as needed into variables.
My preferred way of doing this is to create a separate template file that can be loaded dynamically in development and baked into pure js for production.
Specifically I use eco templates (I wouldn't recommend them unless you're familiar with coffee script) and Stitch for node.js. Stitch supports custom engines tied to file extensions, so when it finds an eco file in my project directory it compiles it into a Javascript function. I can now include that function in any other part of my application using the stitch provided require function using the original path of the eco file. So if the template resided in src/views/listItem.eco I would run var listItemView = require('views/listItem'); to fetch it and use it like this
var html = listItemView({item: items[i]});
$someElement.html(html);
You could use require.js instead of stitch if course, or any other similar framework.
Update: after another day of digging
into this issue, I have found that the
current jQuery template lib provides
no way to do this. this article
describes a good approach.
I would still like to hear of any
additional thoughts on doing this. The
article linked above requires that the
returned string of templates be
inserted into the DOM. Seems as though
leaving the DOM out of this would be
ideal, and less overhead on the
browser. Imagine a large page, with
multiple composite templates that may
not get used. Although, maybe because
the templates are wrapped in a script
tag, there is only a single DOM item per template? Come on, let's
hear some thoughts...
Using jQuery template libs, what's the best way to combine multiple, related, relatively small templates together? Do you need a single <script> tag for each individual template? What about in the case of dynamically pulling these templates via AJAX? Can I combine these templates somehow?
Consider the following:
<script id="movieTemplate" type="text/x-jquery-tmpl">
{{tmpl "#titleTemplate"}}
<tr class="detail"><td>Director: ${Director}</td></tr>
</script>
<script id="titleTemplate" type="text/x-jquery-tmpl">
<tr class="title"><td>${Name}</td></tr>
</script>
Now because these two templates are very closely related (and one depends on the other) it would make sense to consolidate these into a single AJAX call, and get them both at once. I have a few ideas, but I'd like to know if there is common/best way to do this? Currently I pull in a chunk of HTML, and then do a .find() to get the specific peice of HTML for a template... e.g.:
var templatePackage = fancyAjaxCalltoGetTemplates();
"templatePackage" might then look like this:
<div id="templatePkg">
<div id="movieTemplate">
{{tmpl "#titleTemplate"}}
<tr class="detail"><td>Director: ${Director}</td></tr>
</div>
<div id="titleTemplate">
<tr class="title"><td>${Name}</td></tr>
</div>
</div>
I could then do:
var titleTemplate = jQuery.template('titleTemplate', $(templatePackage).find('#titleTemplate') );
and
var movieTemplate = jQuery.template('movieTemplate', $(templatePackage).find('#movieTemplate') );
...let me know what you think... what would you do?
I like the referenced article in your update, except the assumption that you can't cache templates unless you insert them into the DOM. From the jQuery.tmpl documentation,
"To cache the template when using markup that is obtained from a string (rather than from inline markup in the page), use $.template( name, markup ) to create a named template for reuse. See jQuery.template()."
Using this, we can build a javascript template management system that allows us to load as many templates at a time as we need while keeping the DOM clean. On the client, keep a hash of template objects by name. You can use your favorite object based javascript pattern here, but I would think the structure could be like this:
templates[templateName] = {
templateMarkup: markupFromServer,
loadedAt: Date.now(),
compiledTemplateFunction: jQuery.template( templateName, markupFromServer )
}
Then use the templates to generate HTML like this:
templates['unique-name'].compiledTemplateFunction(inputData)
Then, build an unload mechanism to free up memory:
function unload(templateName) {
delete templates[templateName];
delete jquery.template[templateName];
}
Most importantly, you now have a method of storing multiple templates so you can make requests like: $.get('/TemplateManagement/Render', arrayOfTemplateNamesToLoad, loadManyTemplatesSuccess) to load multiple templates at a time. The only thing we need is a controller TemplateManagement that will take an array of template names as an input and return JSON that pairs a template name with its markup. There are a few ways to do this but it seems to me the most convenient is to define partial views for each template. In ASP.NET MVC 3, you can use this technique and RenderPartial to emit each template's markup into a JSON response. You can either name the partial views the same as the templates or map the names in some custom way.
OK, I read the article you reference in this post. As I see it, his way is probably one of the best ways to load up the template page(s). The only thing I don't like is the asynchronous problems that could crop up, esp. if you need to immediately do some templating before the async get returns... plus any binding issues that could happen before it returns something. In several projects I have done I use his "ancient" SSI (server side includes), but I just use something even easier like:
<% Response.WriteFile("this_page_template_file.html"); %>
You could put it anywhere where you'd place a tag. Like he says, just put in only the templates you need, or maybe include two templates: one is a "base" template with commonly-used items and the second one would have the page-specific ones with template references {{tmpl}}.
Is this even close to an answer? ;-)
[First off, great question. I love this topic]
I have no experience with the plugin "jquery-template-libs", but there is a particular lightweight javascript template plugins that are becoming almost a standard and plays very nicely with jQuery, which is probably better suited for the task than JTL, Mustache:
https://github.com/janl/mustache.js
It's got something that's called a "partial" which is essentially a way to include smaller templates within another one. Which sounds like it will help you out a lot.
On top of that there is a library called ICanHaz.js:
http://icanhazjs.com/
ICanHaz essentially extends Mustache to include built in functionality for templates and works incredibly well.
Mustache/ICanHaz allow you to add templates by variable, by a json call or by using tags. The choice is yours.
I know this is an old question but you might want to take a look at Closure-Templates. They provide the kind of functionality you're after with the added advantage of being compiled into JavaScript at compile-time instead of at run-time in each user's browser.
If you do decide to look into using them then I'd suggest using plovr for building them.
I'd like to split my views in Grails into 2 files a .gsp file and a .js file so that I get a cleaner Javascript separation from my views. So here's an example:
views/index.gsp
views/index.js
views/home/index.jsp
views/home/index.js
But when I simply add the index.js script reference like this:
<script src="index.js" type="text/javascript"></script>
all I get is a 404.
Does anyone knows how to deal with this?
A great benefit would be to have the ability to use view data inside the index.js file to produce the desired content.
Matthias.
Actually, it should be perfectly possible to serve a JS file (or any other file type) as a GSP from your grails-app/views/ directory. The only thing you have to do, is define a suitable URL mapping for those GSPs, e.g.:
"/javascript/home/index"(view:'/home/index.js')
With this URL mapping, you can put your JS code into grails-app/views/home/index.js.gsp (note the trailing .gsp) and you can use any grails tags in your JS source. To ensure that your JS is delivered with the correct content type, you may want to place
<%# page contentType="text/javascript"%>
at the beginning of your GSP.
Unfortunately, the createLink tag doesn't support link rewriting to views, but it should be easy to write your own tag to create those links.
Anyways, keep in mind that this won't have a very positive impact on your app's performance. It's usually better to have static JS files (and also serve them as static resources) while passing dynamic stuff as parameters to JS functions for example. This will also keep you from some headaches wrt. caching etc.
The idea is good, but Grails has this directory structure for a reason. The view folder is intended for a certain artifact type (views)..
You could clone your view folder structure under web-inf, but that gives you more work as I guess the idea behind this is to keep related files close together for convenience reasons.
Even though I'm not to excited about storing Javascript together with the view I loved Robert's idea of hooking into the build process by using build events to copy javascript sources into the right directory! If you decide to go down that road you might as well compress the sources while you're at it. ShrinkSafe is popular library.
I don't think you are allowed to access js inside views/
if you need to do that ... here is the trick
create your js and rename it with myjs.gsp (use "")
iniside _myjs.gsp type you js
... write down you js in here ...
inside you gsp (for example: index.gsp, view.gsp, etc)
type this tag to upload you js
Update 2:
Grails offer the possibility of hooking into the build lifecycle using custom events.
An event handler can be written which synchronises all JavaScript files under grails-app/views with the target folder of web-app/js.
Place the custom code in $PROJECT/scripts/Events.groovy. The PackagingEnd is a good target for the invocation, since it happens right after web.xml is generated.
eventPackagingEnd = { ->
// for each js file under grails-app/views move to web-app/js
}
Update
If you'd like the JavaScript files simply 'meshed' together, you can do that using symlinks, e.g.:
grails-app/views/view1/index.js -> webapp/js/view1/index.js
As far as I know, there is no way of forcing grails to directly serve content which is outside of web-app.
Alternatively, you can inline your JavaScript, but that can have performance implications.
JavaScript files belong under web-app/js.
Then you can reference them using <g:javascript src="index.js" />.