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<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8" />
<base href="../../../../" />
<script src="page.js"></script>
<link type="text/css" rel="stylesheet" href="page.css" />
</head>
<body>
<h1>[name]</h1>
<p class="desc">
Handles and keeps track of loaded and pending data. A default global instance of this class
is created and used by loaders if not supplied manually - see [page:DefaultLoadingManager].<br /><br />
In general that should be sufficient, however there are times when it can be useful to have separate loaders -
for example if you want to show separate loading bars for objects and textures.
</p>
<h2>Code Example</h2>
<p>
This example shows how to use LoadingManager to track the progress of
[page:OBJLoader].
</p>
<code>
const manager = new THREE.LoadingManager();
manager.onStart = function ( url, itemsLoaded, itemsTotal ) {
console.log( 'Started loading file: ' + url + '.\nLoaded ' + itemsLoaded + ' of ' + itemsTotal + ' files.' );
};
manager.onLoad = function ( ) {
console.log( 'Loading complete!');
};
manager.onProgress = function ( url, itemsLoaded, itemsTotal ) {
console.log( 'Loading file: ' + url + '.\nLoaded ' + itemsLoaded + ' of ' + itemsTotal + ' files.' );
};
manager.onError = function ( url ) {
console.log( 'There was an error loading ' + url );
};
const loader = new THREE.OBJLoader( manager );
loader.load( 'file.obj', function ( object ) {
//
} );
</code>
<p>
In addition to observing progress, a LoadingManager can be used to
override resource URLs during loading. This may be helpful for assets
coming from drag-and-drop events, WebSockets, WebRTC, or other APIs. An
example showing how to load an in-memory model using Blob URLs is below.
</p>
<code>
// Blob or File objects created when dragging files into the webpage.
const blobs = {'fish.gltf': blob1, 'diffuse.png': blob2, 'normal.png': blob3};
const manager = new THREE.LoadingManager();
// Initialize loading manager with URL callback.
const objectURLs = [];
manager.setURLModifier( ( url ) => {
url = URL.createObjectURL( blobs[ url ] );
objectURLs.push( url );
return url;
} );
// Load as usual, then revoke the blob URLs.
const loader = new THREE.GLTFLoader( manager );
loader.load( 'fish.gltf', (gltf) => {
scene.add( gltf.scene );
objectURLs.forEach( ( url ) => URL.revokeObjectURL( url ) );
});
</code>
<h2>Examples</h2>
<p>
[example:webgl_loader_obj WebGL / loader / obj]<br />
[example:webgl_materials_physical_reflectivity WebGL / materials / physical / reflectivity]<br />
[example:webgl_postprocessing_outline WebGL / postprocesing / outline]
</p>
<h2>Constructor</h2>
<h3>[name]( [param:Function onLoad], [param:Function onProgress], [param:Function onError] )</h3>
<p>
[page:Function onLoad] — (optional) this function will be called when all loaders are done.<br />
[page:Function onProgress] — (optional) this function will be called when an item is complete.<br />
[page:Function onError] — (optional) this function will be called a loader encounters errors. <br />
Creates a new [name].
</p>
<h2>Properties</h2>
<h3>[property:Function onStart]</h3>
<p>
This function will be called when loading starts.
The arguments are:<br />
[page:String url] — The url of the item just loaded.<br />
[page:Integer itemsLoaded] — the number of items already loaded so far.<br />
[page:Integer itemsTotal] — the total amount of items to be loaded.<br /><br />
By default this is undefined.
</p>
<h3>[property:Function onLoad]</h3>
<p>
This function will be called when all loading is completed. By default this is undefined,
unless passed in the constructor.
</p>
<h3>[property:Function onProgress]</h3>
<p>
This function will be called when an item is complete.
The arguments are:<br />
[page:String url] — The url of the item just loaded.<br />
[page:Integer itemsLoaded] — the number of items already loaded so far.<br />
[page:Integer itemsTotal] — the total amount of items to be loaded.<br /><br />
By default this is undefined, unless passed in the constructor.
</p>
<h3>[property:Function onError]</h3>
<p>
This function will be called when any item errors, with the argument:<br />
[page:String url] — The url of the item that errored.<br /><br />
By default this is undefined, unless passed in the constructor.
</p>
<h2>Methods</h2>
<h3>[method:this addHandler]( [param:Object regex], [param:Loader loader] )</h3>
<p>
[page:Object regex] — A regular expression.<br />
[page:Loader loader] — The loader.
<p>
Registers a loader with the given regular expression. Can be used to define what loader should be used in
order to load specific files. A typical use case is to overwrite the default loader for textures.
</p>
<code>
// add handler for TGA textures
manager.addHandler( /\.tga$/i, new TGALoader() );
</code>
<h3>[method:Loader getHandler]( [param:String file] )</h3>
<p>
[page:String file] — The file path.
<p>
Can be used to retrieve the registered loader for the given file path.
</p>
<h3>[method:this removeHandler]( [param:Object regex] )</h3>
<p>
[page:Object regex] — A regular expression.
<p>
Removes the loader for the given regular expression.
</p>
<h3>[method:String resolveURL]( [param:String url] )</h3>
<p>
[page:String url] — the url to load<br /><br />
Given a URL, uses the URL modifier callback (if any) and returns a resolved URL. If no
URL modifier is set, returns the original URL.
</p>
<h3>[method:this setURLModifier]( [param:Function callback] )</h3>
<p>
[page:Function callback] — URL modifier callback. Called with [page:String url] argument, and
must return [page:String resolvedURL].<br /><br />
If provided, the callback will be passed each resource URL before a request is sent. The
callback may return the original URL, or a new URL to override loading behavior. This
behavior can be used to load assets from .ZIP files, drag-and-drop APIs, and Data URIs.
</p>
<br />
<p>
<em>Note: The following methods are designed to be called internally by loaders. You shouldn't call
them directly.</em>
</p>
<h3>[method:undefined itemStart]( [param:String url] )</h3>
<p>
[page:String url] — the url to load<br /><br />
This should be called by any loader using the manager when the loader starts loading an url.
</p>
<h3>[method:undefined itemEnd]( [param:String url] )</h3>
<p>
[page:String url] — the loaded url<br /><br />
This should be called by any loader using the manager when the loader ended loading an url.
</p>
<h3>[method:undefined itemError]( [param:String url] )</h3>
<p>
[page:String url] — the loaded url<br /><br />
This should be called by any loader using the manager when the loader errors loading an url.
</p>
<h2>Source</h2>
<p>
[link:https://github.com/mrdoob/three.js/blob/master/src/loaders/LoadingManager.js src/loaders/LoadingManager.js]
</p>
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</html>