Dust

This is the LinkedIn fork of dust.js

Details in the blog post : http://engineering.linkedin.com/frontend/leaving-jsps-dust-moving-linkedin-dustjs-client-side-templates

We will gradually be extending this library with helper functions and bug fixes.

Current LinkedIn additions include:

• Fix to peg.js to print the line and column number for syntax errors in dust templates
• Fix to support > node0.4
• Addition of jasmine test suite, BDD with dust.js
• There are cases of rendering logic that are best done in templates. @if helper that relies entirely on the js eval for expression evaluation, The perf results are here: http://jsperf.com/dust-if. We intend to replace the slow js eval with a expression parser soon
• Section index for lists of maps stored in the dust context for ease of writing simple logic in templates
• Section size for lists of maps stored in the dust context for ease of writing simple logic in templates

Asynchronous templates for the browser and node.js

http://akdubya.github.com/dustjs

Why?

I like Mustache and variants but none of them offers quite what I need.

Use Dust if you want these things:

• async/streaming operation
• browser/node compatibility
• extended Mustache/ctemplate syntax
• clean, low-level API
• high performance
• composable templates

Composable templates?

{^xhr}
  {>base_template/}
{:else}
  {+main/}
{/xhr}
{<title}
  Child Title
{/title}
{<main}
  Child Content
{/main}

Installation

In Node:

$ npm install dust

To render compiled templates in the browser:

<script src="dust-core-0.3.0.min.js"></script>

Demo & Guide

ß Extensive docs and a full demo are available at http://akdubya.github.com/dustjs

Support logic helper @if

Example 1:

 {@if cond="('{x}'.length || '{y}'.length ) || (2 > 3) && {a}-{b} == 9"}
  render if
 {:else}
  render else
 {/if}

Section index for lists of maps stored in the dust context

Example 2: $idx is the Loop index in dust #loop

{#people}
<li class="card  
 {@if cond="({$idx} == {$len})"}last{/if}" data-member-id="{id}"  id="card-{id}">
 </li>
{/people}

Section size for lists of maps stored in the dust context

Example 3: $len, Loop size in dust #loop

{#people} 
<li class="card  {@if cond="({$len} + 1) % 2 == 0"} odd {:else} even {/if} " data-member-id="{id}"  id="card\-{id}"> </li> 
{/people}

Example 4: Inside lists of primitives,$idx and $len cannot be used, and {@idx} can be used instead

JSON : {"skills": ["jasmine", "qunit", "javascript"]}
{#skills}
 <li>
 <span class='{@idx}
  {@if cond="{.} == '{skills}'.split(',').length -1"}
    last
  {/if}
 {/idx}'>
 {.}</span> 
 </li>
{/skills}

Example 5: @if with else

{@if cond="'{names}'.split(',').length == 3 "}
 {@pre.i18n key="yes" text="Yes, there are 3 names"/} 
{:else}
 {@pre.i18n key="no" text="No, there are less than 3 names"/}
{/if}

Global Aliases in dust

Most often we tend to reuse the same data in the template again and again ... One way to avoid been repetitive is use aliases. So a common question was, how does dust support this ?

Well, in dust there is more than one way neat way to do this.

Use Inline Partials

Inline partials never output content themselves, and are always global to the template in which they are defined, so the order of their definition has no significance.

Key points to note : They are global to the template., there is no ordering and can be defined anywhere

Step 1 create global alias

 {<greeting}Hello, Hola{/greeting}   

Step 2

 {#names}
   {.} {+greeting/} 
 {/names}

 {#projects}
   {.} {+greeting/}
 {/projects}

Block Aliases in dust

Inline parameters appear within the section's opening tag. Parameters are separated by a single space.

 {#profile bar="baz" bing="bong"}
  {name}, {bar}, {bing}
 {/profile}

There are 3 flavors

{#test greeting="hello"} // constant hello
 {greeting}
{/test}

{#test greeting=hello} // looks for a json context hello in the JSON hierarchy
 {greeting}
{/test}


{#test greeting="{hello}"} // resolves hello when greeting is referenced in the block and it    resolves to the first one in the hierarchy
 {greeting}
{/test}