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## JsRender: best-of-breed templating

*Simple and intuitive, powerful and extensible, lightning fast*

*For templated content in the browser or on Node.js (with Express 4, Hapi and Browserify integration)*

**JsRender** is a light-weight but powerful templating engine, highly extensible, and optimized for high-performance rendering, without DOM dependency. It is designed for use in the browser or on Node.js, with or without jQuery.

**[JsRender](https://github.com/BorisMoore/jsrender)** and **[JsViews](https://github.com/BorisMoore/jsviews)** together provide the next-generation implementation of the official jQuery plugins *[JQuery Templates](https://github.com/BorisMoore/jquery-tmpl)*, and *[JQuery Data Link](https://github.com/BorisMoore/jquery-datalink)* -- and supersede those libraries.

### Documentation and downloads

**[Documentation](http://www.jsviews.com)**, **[downloads](http://www.jsviews.com/#download)**, **[samples](http://www.jsviews.com/#samples)** and **[API docs and tutorials](http://www.jsviews.com/#jsrapi)** are available on the **[www.jsviews.com website](http://www.jsviews.com/#jsrender)**.

The content of this ***ReadMe*** is available also as a *[JsRender Quickstart](http://www.jsviews.com/#jsr-quickstart)*.

### JsRender and JsViews

JsRender is used for data-driven rendering of templates to strings, ready for insertion in the DOM.

It is also used by the *[JsViews](http://www.jsviews.com/#jsviews)* platform, which adds data binding to JsRender templates, and provides a fully-fledged MVVM platform for easily creating interactive data-driven single page apps and websites.

## JsRender installation

*jsrender.js* is available from [downloads](http://www.jsviews.com/#download) on the jsviews.com site.

*CDN delivery* is available from the ***[cdnjs](https://cdnjs.com)*** CDN at [cdnjs.com/libraries/jsrender](https://cdnjs.com/libraries/jsrender).

Alternatively:

- It can be installed with **[Bower](http://bower.io/search/?q=jsrender)**, using `$ bower install jsrender`

- It can be loaded using an *AMD script loader*, such as RequireJS

- For installation using *Node.js* (*npm*) see *[JsRender Node.js Quickstart](http://www.jsviews.com/#jsr-node-quickstart)*

- (For browser loading using *Browserify* or *webpack* - see *[JsRender Node.js Quickstart](http://www.jsviews.com/#jsr-node-quickstart)*, *[JsRender as a Browserify module](http://www.jsviews.com/#node/browserify@jsrender)* and *[JsRender as a webpack module](http://www.jsviews.com/#node/webpack@jsrender)*)

#### Using JsRender with jQuery

When jQuery is present, JsRender loads as a jQuery plugin and adds `$.views`, `$.templates` and `$.render` to the jQuery namespace object, `$` (or `window.jQuery`).

*Example HTML page:* [JsRender with jQuery](http://www.jsviews.com/#download/pages-jsr-jq)

#### Using JsRender without jQuery

When jQuery is not present, JsRender provides its own `jsrender` namespace object, exposed as `window.jsrender`

The `jsrender` namespace provides the same methods/APIs as with jQuery, so if jQuery is not present you can still use all the API examples, by simply writing:

```js

var $ = window.jsrender;

// Now use code as in samples/examples, with $.views... $.templates... $.render...

```

*Example HTML page:* [JsRender without jQuery](http://www.jsviews.com/#download/pages-jsr)

#### JsRender on Node.js

JsRender can be used to render templates on the server (using Node.js) as well as in the browser. JsRender on Node.js has all the features and APIs of JsRender in the browser, plus some additional ones specific to Node.js.

It also provides built-in *Express*, *Hapi* and *Browserify* integration -- which makes it easy to register templates as simple `.html` files on the file system, and then load and render them either server-side, client-side or both.

**Learn more:** *[JsRender Node.js Quickstart](http://www.jsviews.com/#jsr-node-quickstart)* and *[JsRender APIs for Node.js](http://www.jsviews.com/#jsrnode)*.

**Code samples:** See *[JsRender Node Starter](https://github.com/BorisMoore/jsrender-node-starter)* for running code examples of Node.js scenarios, including with *Express*, *Hapi* and *Browserify*.

## JsRender usage

### _Define a template_

From a string:

```js

var tmpl = $.templates("Name: {{:name}}");

```

From a template declared as markup in a script block:

```html

<script id="myTemplate" type="text/x-jsrender">

Name: {{:name}}

</script>

```

then, somewhere in your script:

```js

var tmpl = $.templates("#myTemplate");

```

On Node.js, from an .html file containing the template markup:

```js

var $ = require('jsrender'); // returns the jsrender namespace object

var tmpl = $.templates("./templates/myTemplate.html");

```

[Learn more...](http://www.jsviews.com/#d.templates)

### _Render a template_

`tmpl.render(object)` (or shortcut form: `tmpl(object)`) renders the template with the object as data context.

```js

var tmpl = $.templates(" Name: {{:name}}<br/> ");

var person = {name: "Jim"};

// Render template for person object

var html = tmpl.render(person); // ready for insertion, e.g $("#result").html(html);

// result: "Name: Jim<br/> "

```

`tmpl.render(array)` (or `tmpl(array)`) renders the template once for each item in the array.

```js

var people = [{name: "Jim"}, {name: "Pedro"}];

// Render template for people array

var html = tmpl.render(people); // ready for insertion...

// result: "Name: Jim<br/> Name: Pedro<br/> "

```

[Learn more...](http://www.jsviews.com/#rendertmpl)

### _Register a named template - and render it_

```js

// Register named template - "myTmpl1

$.templates("myTmpl1", "Name: {{:name}}<br/> ");

var person = {name: "Jim"};

// Render named template

var html = $.templates.myTmpl1(person);

// Alternative syntax: var html = $.render.myTmpl1(person);

// result: "Name: Jim<br/> "

```

[Learn more...](http://www.jsviews.com/#rendertmpl)

### _Template tags_

#### Template tag syntax

- All tags other than `{{: ...}}` `{{> ...}}` `{{* ...}}` `{{!-- --}}` behave as *block tags*

- Block tags can have content, unless they use the self-closing syntax:

    - *Block tag - with content:* `{{someTag ...}} content {{/someTag}}`

    - *Self-closing tag - no content (empty):* `{{someTag .../}}`

- A particular case of self-closing syntax is when any block tag uses the named parameter `tmpl=...` to reference an external template, which then replaces what would have been the block content:

    - *Self-closing block tag referencing an external template:* `{{someTag ... tmpl=.../}}`

 (This lets you do [template composition](http://www.jsviews.com/#tagsyntax@composition). See [example](http://www.jsviews.com/#samples/jsr/composition/tmpl).)

- Tags can take both unnamed arguments and named parameters:

    - `{{someTag argument1 param1=...}} content {{/someTag}}`

    - an example of a named parameter is the `tmpl=...` parameter mentioned above

    - arguments and named parameters can be assigned values from simple data-paths such as `address.street` or from richer expressions such as `product.quantity * 3.1 / 4.5`, or `name.toUpperCase()`

[Learn more...](http://www.jsviews.com/#tagsyntax)

#### Built-in tags

#### _{{: ...}}_ (Evaluate)

`{{: pathOrExpr}}` inserts the value of the path or expression.

```js

var data = {address: {street: "Main Street"} };

var tmpl = $.templates("<b>Street:</b> {{:address.street}}");

var html = tmpl.render(data);

// result: "<b>Street:</b> Main Street"

```

[Learn more...](http://www.jsviews.com/#assigntag)

#### _{{> ...}}_ (HTML-encode)

`{{> pathOrExpr}}` inserts the *HTML-encoded* value of the path or expression.

```js

var data = {condition: "a < b"};

var tmpl = $.templates("<b>Formula:</b> {{>condition}}");

var html = tmpl.render(data);

// result: "<b>Formula:</b> a &lt; b"

```

[Learn more...](http://www.jsviews.com/#htmltag)

#### _{{include ...}}_ (Template composition - partials)

`{{include pathOrExpr}}...{{/include}}`evaluates the block content against a specified/modified data context.

`{{include ... tmpl=.../}}` evaluates the specified template against an (optionally modified) context, and inserts the result. (Template composition).

```js

var data = {name: "Jim", address: {street: "Main Street"} };

// Register two named templates

$.templates({

  streetTmpl: "<i>{{:street}}</i>",

  addressTmpl: "{{:name}}'s address is {{include address tmpl='streetTmpl'/}}."

});

// Render outer template

var html = $.templates.addressTmpl(data);

// result: "Jim's address is <i>Main Street</i>"

```

[Learn more...](http://www.jsviews.com/#includetag)

#### _{{for ...}}_ (Template composition, with iteration over arrays)

`{{for pathOrExpr}}...{{/for}}`evaluates the block content against a specified data context. If the new data context is an array, it iterates over the array, renders the block content with each data item as context, and concatenates the result.

`{{for pathOrExpr tmpl=.../}}` evaluates the specified template against a data context. If the new data context is an array, it iterates over the array, renders the template with each data item as context, and concatenates the result.

```html

<script id="peopleTmpl" type="text/x-jsrender">

  <ul>{{for people}}

    <li>Name: {{:name}}</li>

  {{/for}}</ul>

</script>

```

```js

var data = {people: [{name: "Jim"}, {name: "Pedro"}] };

var tmpl = $.templates("#peopleTmpl");

var html = tmpl.render(data);

// result: "<ul> <li>Name: Jim</li> <li>Name: Pedro</li> </ul>"

```

[Learn more...](http://www.jsviews.com/#fortag)

#### _{{props ...}}_ (Iteration over properties of an object)

`{{props pathOrExpr}}...{{/prop}}` or `{{props pathOrExpr tmpl=.../}}` iterates over the properties of the object returned by the path or expression, and renders the content/template once for each property - using as data context: `{key: propertyName, prop: propertyValue}`.

```html

<script id="personTmpl" type="text/x-jsrender">

  <ul>{{props person}}

    <li>{{:key}}: {{:prop}}</li>

  {{/props}}</ul>

</script>

```

```js

var data = {person: {first: "Jim", last: "Varsov"} };

var tmpl = $.templates("#personTmpl");

var html = tmpl.render(data);

// result: "<ul> <li>first: Jim</li> <li>last: Varsov</li> </ul>"

```

[Learn more...](http://www.jsviews.com/#propstag)

#### _{{if ...}}_ (Conditional inclusion)

`{{if pathOrExpr}}...{{/if}}` or `{{if pathOrExpr tmpl=.../}}` renders the content/template only if the evaluated path or expression is 'truthy'.

`{{if pathOrExpr}}...{{else pathOrExpr2}}...{{else}}...{{/if}}` behaves as '*if' - 'else if' - 'else'* and renders each block based on the conditions.

```html

<script id="personTmpl" type="text/x-jsrender">

  {{if nickname}}

    Nickname: {{:nickname}}

  {{else name}}

    Name: {{:name}}

  {{else}}

    No name provided

  {{/if}}

</script>

```

```js

var data = {nickname: "Jim", name: "James"};

var tmpl = $.templates("#personTmpl");

var html = tmpl.render(data);

// result: "Nickname: Jim"

```

[Learn more...](http://www.jsviews.com/#iftag)

#### Other built-in tags

For details on all the above built-in tags, as well as *[comment tags](http://www.jsviews.com/#commenttag)* _{{!-- ... --}}_ and *[allow code tags](http://www.jsviews.com/#allowcodetag)* _{{\* ... }} and {{\*: ...}}_, see the [tags documentation](http://www.jsviews.com/#jsrtags) on jsviews.com.

#### Custom tags

Creating your own custom tags is easy. You can provide an object, with render method, template, event handlers, etc. See samples [here](http://www.jsviews.com/#samples/jsr/tags) and [here](http://www.jsviews.com/#samples/tag-controls) on jsviews.com. But for simple tags, you may only need a simple render function, or a template string.

For example the two following definitions for a `{{fullName/}}` tag provide equivalent behavior:

As a render function:

```js

$.views.tags("fullName", function(val) {

  return val.first + " " + val.last;

});

```

Or as a template string:

```js

$.views.tags("fullName", "{{:first}} {{:last}}");

```

Either way, the result will be as follows:

```js

var tmpl = $.templates("{{fullName person/}}");

var data = {person: {first: "Jim", last: "Varsov"}};

var html = tmpl.render(data);

// result: "Jim Varsov"

```

### _Helpers_

For details on helpers, see the [Helpers](http://www.jsviews.com/#helpers) documentation topic on jsviews.com.

Here is a simple example. Two helpers - a function, and a string:

```js

var myHelpers = {

  upper: function(val) { return val.toUpperCase(); },

  title: "Sir"

};

```

Access the helpers using the `~myhelper` syntax:

```js

var tmpl = $.templates("{{:~title}} {{:first}} {{:~upper(last)}}");

```

We can pass the helpers in with the `render()` method

```js

var data = {first: "Jim", last: "Varsov"};

var html = tmpl.render(data, myHelpers);

// result: "Sir Jim VARSOV"

```

Or we can register helpers globally:

```js

$.views.helpers(myHelpers);

var data = {first: "Jim", last: "Varsov"};

var html = tmpl.render(data);

// result: "Sir Jim VARSOV"

```

[Learn more...](http://www.jsviews.com/#helpers)

### _Converters_

Converters are used with the `{{:...}}` tag, using the syntax `{{mycvtr: ...}}}`.

Example - an *upper* converter, to convert to upper case:

```js

$.views.converters("upper", function(val) { return val.toUpperCase(); });

var tmpl = $.templates("{{:first}} {{upper:last}}");

var data = {first: "Jim", last: "Varsov"};

var html = tmpl.render(data);

// result: "Jim VARSOV"

```

[Learn more...](http://www.jsviews.com/#converters)

### _Logic and expressions_

JsRender supports rich expressions and logic, but at the same time encapsulates templates to prevent random access to globals. If you want to provide access to global variables within a template, you have to pass them in as data or as helpers.

You can assign rich expressions to any template arguments or parameters, as in:

`{{:person.nickname ? "Nickname: " + person.nickname : "(has no nickname)"}}`

or

```html

{{if ~limits.maxVal > (product.price*100 - discount)/rate}}

  ...

{{else ~limits.minVal < product.price}}

  ...

{{else}}

  ...

{{/if}}

```

### _Documentation and APIs_

See the [www.jsviews.com](http://www.jsviews.com) site, including the *[JsRender Quickstart](http://www.jsviews.com/#jsr-quickstart)* and [JsRender APIs](http://www.jsviews.com/#jsrapi) topics.

### _Demos_

Demos and samples can be found at [www.jsviews.com/#samples](http://www.jsviews.com/#samples/jsr), and throughout the [API documentation](http://www.jsviews.com/#jsrapi).

(See also the [demos](https://github.com/BorisMoore/jsrender/tree/master/demos) folder of the GitHub repository - available [here](http://borismoore.github.io/jsrender/demos/index.html) as live samples).