Knockout Mustached Syntax

This library provides a tool which compiles mustached interpolation syntax into knockout binding declarations.

Installation

Using npm: npm install ko-mustached

Or

Just clone repository and assemble all the files with grunt:

git clone git@github.com:stalniy/ko-mustached.git
cd ko-mustached
npm install
grunt # or grunt test if you want just test the package

What is the goal?

The goal is to simplify knockout templates.

What it does

It is just a compiler and works only with strings, it knows nothing about your view models and another js code, but it can:

• compiles string with mustached expressions into knockout virtual bindings
• compiles DOM node attributes into bindings if such exists
• compiles all DOM node attributes which start with ko- into bindings
• compiles attributes which contains mustached expressions into knockout attr binding
• allows to apply text filters
• allows to define custom syntax for bindings
• allows to create aliases for bindings which may have their own syntax
• automatically close specified virtual bindings (by default "partial" and "template" bindings)
• provides "partial" alias of "template" binding but with more freandly syntax ({{ partial: templateName, param: 1, param2: 2 }})
• provides custom syntax for "foreach" binding ({{ foreach: template in templates }} {{ template.name }} {{ /end }})

Example

<div if="hasTemplates()">
  {{ foreach: template in templates }}
    <a href="#" data-id="id-{{ id | dasherize }}" id="test" title="{{ title | upper }}">{{ name | upper }}</a>
    <input value="title, valueUpdate: 'afterkeydown'" css="active: isActive, disabled: isLocked" />
  {{ /end }}
</div>

This example is compiled to:

<div data-bind="'if':hasTemplates()">
  <!--ko foreach:{data:templates ,as:'template'}-->
    <a href="#" id="test" data-bind="attr:{'data-id':'id-'+dasherize(u(id)),'title':upper(u(title))}">
      <!--ko text:upper(name)--><!--/ko-->
    </a>
    <input type="text" data-bind="'css':{active: isActive, disabled: isLocked}, 'value':title, valueUpdate: 'afterkeydown'" />
  <!--/ko-->
</div>

Note: "u" filter is ko.unwrap.

Configuration options

Mustached interpolator has few configuration options:

• document - document object
• bindings - object map of available bindings
• compileFilter - function which receives text filter name and returns new name which is used in compiled html

For example:

mustached.interpolator.configure({
  document: window.document,
  bindings: ko.bindingHandlers,
  compileFilter: function (name) {
    return "ko.filters['" + name + "']";
  }
})

So, then {{ title | upper }} will be compiled to <!--ko text:ko.filters['upper'](title)--><!--/ko-->

How to use with AMD

Create a very SIMPLE plugin:

define(['knockout', 'ko-mustached'], function (ko, mustached) {
  mustached.interpolator.configure({
    document: window.document,
    bindings: ko.bindingHandlers
  });

  return {
    load: function (template, require, onload, config) {
      require(['text!' + template], function (html) {
        html = mustached.interpolator.compile(html);
        onload(html);
      });
    }
  };
});

require.config({
  paths: {
    kom: 'path to amd plugin'
  }
});

And then load your templates:

require(['knockout', 'path/to/view/model', 'kom!path/to/template.html'], function (ko, viewModel, html) {
  document.body.innerHTML = html;
  ko.applyBindings(viewModel);
});

What about production?

You can precompile your mustached templates using grunt task. If you use non-prefixed attributes for bindings (which names don't start with "ko-") you need to specify all available bindings, otherwise they wll be skipped or compiled as part of attr binding. The easiest way to get the bindings list is to open your application and run in js console Object.keys(ko.bindingHandlers).

Example of grunt task:

grunt.initConfig({
  'ko-mustached': {
    options: {
      bindings: [
        "attr",
        "checked",
        "checkedValue",
        "css",
        "enable",
        "disable",
        "event",
        "foreach",
        "hasfocus",
        "hasFocus",
        "html",
        "if",
        "ifnot",
        "with",
        "options",
        "selectedOptions",
        "style",
        "submit",
        "text",
        "uniqueName",
        "value",
        "visible",
        "click",
        "template"
      ]
    },

    templates: {
      src: [ 'src/templates/mustached.html', 'src/templates/another-mustached.html' ],
      dest: 'build/templates'
    }
  }
});

In case if you want to override source files you can specify override: true. It's useful if you copy mustached templates into temporary folder.

License

Released under the MIT License