# jsTree v.1.0 - json_data plugin

## Description

The `json_data` plugin enables jsTree to convert JSON objects to interactive trees. The data (JSON) can be set up in the config or retrieved from a server (also ondemand). Version 1.0 also introduces the experimental progressive render feature, which is suitable for large heavy trees, when the DOM would be too heavy to manipulate.

The basic structure you need to follow when supplying data in the JSON format is:

    {
    	data : "node_title",
    	// omit `attr` if not needed; the `attr` object gets passed to the jQuery `attr` function
    	attr : { id : "node_identificator", some-other-attribute : "attribute_value" },
    	// `state` and `children` are only used for NON-leaf nodes
    	state: "closed", // or "open", defaults to "closed"
    	children: [ /* an array of child nodes objects */ ]
    }

The attr object will appear as attributes on the resulting `li` node.

You may need to pass some attributes to the `a` node, or set some metadata, or use language versions (for the languages plugin):

    {
    	// `data` can also be an object
    	data : {
    		title : "The node title",
    		// omit when not needed
    		attr : {},
    		// if `icon` contains a slash / it is treated as a file, used for background
    		// otherwise - it is added as a class to the <ins> node
    		icon : "folder"
    	},

    	// the `metadata` property will be saved using the jQuery `data` function on the `li` node
    	metadata : "a string, array, object, etc",

    	// if you use the language plugin - just set this property
    	// also make sure that `data` is an array of objects
    	language : "en" // any code you are using
    }

As seen in the first example below - you can also use a simple string to define a node (Child 1 & Child 2).

## Configuration

### data

A JSON object (or `false` if not used). Default is `false`.

Specifies the content to load into the container and convert to a tree.

### ajax

An object (or `false` if not used). Default is `false`.

The ajax config object is pretty much the same as the jQuery ajax settings object.

The only difference is that you can set the `data` option to a function, that will be executed in the current tree's scope (`this` will be the tree instance) and gets the node about to be open as a paramater (or `-1` for initial load). Whatever you return in the function will be sent to the server as data (so for example you can send the node's ID).

The `error` and `success` functions (if present) also fire in the context of the tree, and if you return a value in the `success` function it will be used to populate the tree - this can be useful if you want to somehow change what the server returned on the client side before it is displayed in the tree.

### correct_state

A Boolean. Default is `false`.

If this option is set to `true` if an AJAX request fails (or returns an empty result), the node that was about to be opened will be converted to a leaf node (the open icon will no longer be displayed).

### progressive_render

A Boolean. Default is `false`.

If this option is set to `true` only the visible (open nodes) parts of the returned JSON are converted to DOM nodes, any hidden parts are saved away and parsed ondemand (when a node becomes visible). This is useful when you have a large nested tree which would result in a heavy DOM.

NOTE:
If both `data` and `ajax` are set the initial tree is rendered from the `data` string. When opening a closed node (that has no loaded children) an AJAX request is made.

## Demos

### Using the data config option

### Using the ajax config option

### Using the progressive render config option

### Using both the data & ajax config options

## API

Both dummy functions - `_is_loaded` and `load_node` are overwritten.

### .load_node_json ( node , success_callback , error_callback )

This function is called instead of `load_node`.

- `mixed` node

  This can be a DOM node, jQuery node or selector pointing to an element you want loaded. Use `-1` for root nodes.

- `function` success_callback

  A function to be executed once the node is loaded successfully - used internally. You should wait for the `load_node` event.

- `function` error_callback

  A function to be executed if the node is not loaded due to an error - used internally. You should wait for the `load_node` event.

### .parse_json ( data , is_callback )

This function converts JSON nodes to the DOM structure required by jstree. Returns a jQuery object.

- `mixed` node

  This can be a tree node in the JSON format described above, or an array of such JSON nodes, may also be a string.

- `bool` is_callback

  Specifies if the function is called recursively - used ONLY internally.

### .get_json ( node , li_attr , a_attr )

This function returns an array of tree nodes converted back to JSON.

- `mixed` node

  This can be a DOM node, jQuery node or selector pointing to an element you want returned. Use `-1` or omit to get the whole tree.

- `array` li_attr

  The attributes to collect from the `LI` node. Defaults to `[ "id" , "class" ]`

- `array` a_attr

  The attributes to collect from the `A` node. Defaults to `[ ]`