Simplify templating with node.js, jsdom 0.2.0 and weld

http://blog.nodejitsu.com/micro-templates-are-dead

by indexzero • 15 years ago

47 18 15 years ago

blog.nodejitsu.com

meikeric• 15 years ago

Good stuff!

gcv• 15 years ago

The Enlive system (for Clojure, see https://github.com/cgrand/enlive) does something very similar.

draegtun• 15 years ago

Yes its nothing new. You can find lots of modules/libraries that have been around for quite that do same/similar things.

Here is a list which was put together & called "Push style template systems" which covers some of these modules/libraries (in different languages): http://www.perlmonks.org/?node_id=674225

gregwebs• 15 years ago

There is also PURE for javascript already. http://beebole.com/pure/

simonw2• 15 years ago

DOM-based templating is a horrible idea, at least for the majority of projects I've ever worked on.

The whole point of using templates is to separate your presentation logic from the rest of your application - ideally, you can hand the templates over to a client-side developer/designer and they can re-jiggle everything on their own.

If your templating code works by performing manipulations against a DOM, even minor changes to your page structure require to to completely rewrite both the templates and the code that manipulates them. I'd much rather leave my "view" code alone and just alter the template.

boucher• 15 years ago

I'd argue that this isn't really that dissimilar from most simple template engines. It's basically substituting class names for placeholder syntax, though with a bit less flexibility for things like repetitions or conditionals. Though I'd agree that I'd rather just use something like Mustache than this.

tmpvar• 15 years ago

How do you rationalize including logic in the markup?

simonw2• 15 years ago

Presentation logic requires logic. If a designer decides to display a bunch of items as three columns rather than two columns, or to switch the display for a single item vs a number of different items, that's presentation logic. Ideally it should go in the template, if that's where you've chosen to keep it.

With Django, I often find myself writing view logic to support specific presentation tasks (regrouping items in a manner more complicated than Django's {% regroup %} template tag allows, for example). This used to bother me, but then I decided that pragmatism beats purity if you actually want to ship anything.

webXL• 15 years ago

I think he just wants to separate the presentation from the logic, which might be good when you don't trust designers re-jiggling things, and you want clean code. Plus, if you're working with a lot of AJAX, it's nice to be able to reproduce the presentation on the server the same way you do it on the client. I suppose keeping the two in sync can be difficult, which is why you probably would only want to render on the server on the initial page request.

reddittor• 15 years ago

I'd have to agree with you, for most traditional web applications.

When you start to build single page applications with lots and lots of states ( that are bound to a DOM ), this approach actually can become favorable since your "presentation logic" is browser-side JavaScript.

To my understanding, the server-side rendering aspect of this approach is really just an after-thought. You have your single page application, but you can still render a server-side snapshot of various UI states without requiring a browser.

While I wouldn't necessarily dive straight into DOM-based templating, I think there is a lot of room for interesting improvements in this area. I'm glad to see JSDOM maturing.

piranha• 15 years ago

Also it's probably worth to mention that manipulation of DOM is not that fast. Every performance optimization article starts with "don't manipulate DOM directly, make a batch of your changes and then inject them in one step".

prodigal_erik• 15 years ago

I don't see any reason for JSDOM in the server to be slow, the object tree being manipulated isn't all that complicated. They aren't suggesting the typical mess of putting useless markup on the wire and then conducting massive repairs to it in the browser's DOM, all while a rendering engine tries to repaint each change.

hij1nx2• 15 years ago

that's subjective (unless you can post tests). for example, one of the primary deficiencies of the dom is live node lists, which is an optimization option in jsdom. (also, we do create a fragment and then attach, as perf opts state)

soljin2000• 15 years ago

http://www.yuiblog.com/blog/2010/09/29/video-glass-node/ This video from David Glass shows why this can be very powerful when code on the front end and the backend. It's pretty straight forward. Check for content. If not generate content. Attach behavior (skipped on the server). render out put (the branch between the server and the front end).

There is an example using express and all kinds of cool business.

jlsync• 15 years ago

My attempt at the same idea using jquery: https://github.com/jlsync/jlt/blob/master/jlt.js

Anyone have any pointers to other/better similar solutions?

georgecalm• 15 years ago

The fact that it's all std-based, and back/front-end rendered is beautiful, but what seriously bothers me is how much weld.js is tied to jQuery.

The README states "Use with whatever library you want, jQuery for example". Let's analyze that for a second.

Weld.js uses the following jQuery methods: - Sizzle selector ($) - first() - is() - val() - attr() - text() - map() - extend() - clone() - data() - remove()

These methods are used throughout the 249 lines of code.

This makes weld.js completely dependent on jQuery. Thus, you can't just use whatever library you want. And that would be allright, if the README would say that; but it didn't, and so it isn't.

hij1nx2• 15 years ago

meh, we might remove jQuery next version.

Simplify templating with node.js, jsdom 0.2.0 and weld

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