phaser
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A fast, free and fun HTML5 Game Framework for Desktop and Mobile web browsers from the team at Phaser Studio Inc.
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JavaScript
/**
* @author Richard Davey <rich@phaser.io>
* @copyright 2013-2025 Phaser Studio Inc.
* @license {@link https://opensource.org/licenses/MIT|MIT License}
*/
var Class = require('../../utils/Class');
var CONST = require('../const');
var File = require('../File');
var FileTypesManager = require('../FileTypesManager');
var GetFastValue = require('../../utils/object/GetFastValue');
var GetValue = require('../../utils/object/GetValue');
var IsPlainObject = require('../../utils/object/IsPlainObject');
/**
* @classdesc
* A single JSON File suitable for loading by the Loader.
*
* These are created when you use the Phaser.Loader.LoaderPlugin#json method and are not typically created directly.
*
* For documentation about what all the arguments and configuration options mean please see Phaser.Loader.LoaderPlugin#json.
*
* @class JSONFile
* @extends Phaser.Loader.File
* @memberof Phaser.Loader.FileTypes
* @constructor
* @since 3.0.0
*
* @param {Phaser.Loader.LoaderPlugin} loader - A reference to the Loader that is responsible for this file.
* @param {(string|Phaser.Types.Loader.FileTypes.JSONFileConfig)} key - The key to use for this file, or a file configuration object.
* @param {(object|string)} [url] - The absolute or relative URL to load this file from. If undefined or `null` it will be set to `<key>.json`, i.e. if `key` was "alien" then the URL will be "alien.json". Or, can be a fully formed JSON Object.
* @param {Phaser.Types.Loader.XHRSettingsObject} [xhrSettings] - Extra XHR Settings specifically for this file.
* @param {string} [dataKey] - When the JSON file loads only this property will be stored in the Cache.
*/
var JSONFile = new Class({
Extends: File,
initialize:
// url can either be a string, in which case it is treated like a proper url, or an object, in which case it is treated as a ready-made JS Object
// dataKey allows you to pluck a specific object out of the JSON and put just that into the cache, rather than the whole thing
function JSONFile (loader, key, url, xhrSettings, dataKey)
{
var extension = 'json';
if (IsPlainObject(key))
{
var config = key;
key = GetFastValue(config, 'key');
url = GetFastValue(config, 'url');
xhrSettings = GetFastValue(config, 'xhrSettings');
extension = GetFastValue(config, 'extension', extension);
dataKey = GetFastValue(config, 'dataKey', dataKey);
}
var fileConfig = {
type: 'json',
cache: loader.cacheManager.json,
extension: extension,
responseType: 'text',
key: key,
url: url,
xhrSettings: xhrSettings,
config: dataKey
};
File.call(this, loader, fileConfig);
// A JSON object has been provided (instead of a URL), so we'll use it directly as the File.data. No need to load it.
if (IsPlainObject(url))
{
if (dataKey)
{
this.data = GetValue(url, dataKey);
}
else
{
this.data = url;
}
this.state = CONST.FILE_POPULATED;
}
},
/**
* Called automatically by Loader.nextFile.
* This method controls what extra work this File does with its loaded data.
*
* @method Phaser.Loader.FileTypes.JSONFile#onProcess
* @since 3.7.0
*/
onProcess: function ()
{
if (this.state !== CONST.FILE_POPULATED)
{
this.state = CONST.FILE_PROCESSING;
try
{
var json = JSON.parse(this.xhrLoader.responseText);
}
catch (e)
{
this.onProcessError();
throw e;
}
var key = this.config;
if (typeof key === 'string')
{
this.data = GetValue(json, key, json);
}
else
{
this.data = json;
}
}
this.onProcessComplete();
}
});
/**
* Adds a JSON file, or array of JSON files, to the current load queue.
*
* You can call this method from within your Scene's `preload`, along with any other files you wish to load:
*
* ```javascript
* function preload ()
* {
* this.load.json('wavedata', 'files/AlienWaveData.json');
* }
* ```
*
* The file is **not** loaded right away. It is added to a queue ready to be loaded either when the loader starts,
* or if it's already running, when the next free load slot becomes available. This happens automatically if you
* are calling this from within the Scene's `preload` method, or a related callback. Because the file is queued
* it means you cannot use the file immediately after calling this method, but must wait for the file to complete.
* The typical flow for a Phaser Scene is that you load assets in the Scene's `preload` method and then when the
* Scene's `create` method is called you are guaranteed that all of those assets are ready for use and have been
* loaded.
*
* The key must be a unique String. It is used to add the file to the global JSON Cache upon a successful load.
* The key should be unique both in terms of files being loaded and files already present in the JSON Cache.
* Loading a file using a key that is already taken will result in a warning. If you wish to replace an existing file
* then remove it from the JSON Cache first, before loading a new one.
*
* Instead of passing arguments you can pass a configuration object, such as:
*
* ```javascript
* this.load.json({
* key: 'wavedata',
* url: 'files/AlienWaveData.json'
* });
* ```
*
* See the documentation for `Phaser.Types.Loader.FileTypes.JSONFileConfig` for more details.
*
* Once the file has finished loading you can access it from its Cache using its key:
*
* ```javascript
* this.load.json('wavedata', 'files/AlienWaveData.json');
* // and later in your game ...
* var data = this.cache.json.get('wavedata');
* ```
*
* If you have specified a prefix in the loader, via `Loader.setPrefix` then this value will be prepended to this files
* key. For example, if the prefix was `LEVEL1.` and the key was `Waves` the final key will be `LEVEL1.Waves` and
* this is what you would use to retrieve the text from the JSON Cache.
*
* The URL can be relative or absolute. If the URL is relative the `Loader.baseURL` and `Loader.path` values will be prepended to it.
*
* If the URL isn't specified the Loader will take the key and create a filename from that. For example if the key is "data"
* and no URL is given then the Loader will set the URL to be "data.json". It will always add `.json` as the extension, although
* this can be overridden if using an object instead of method arguments. If you do not desire this action then provide a URL.
*
* You can also optionally provide a `dataKey` to use. This allows you to extract only a part of the JSON and store it in the Cache,
* rather than the whole file. For example, if your JSON data had a structure like this:
*
* ```json
* {
* "level1": {
* "baddies": {
* "aliens": {},
* "boss": {}
* }
* },
* "level2": {},
* "level3": {}
* }
* ```
*
* And you only wanted to store the `boss` data in the Cache, then you could pass `level1.baddies.boss`as the `dataKey`.
*
* Note: The ability to load this type of file will only be available if the JSON File type has been built into Phaser.
* It is available in the default build but can be excluded from custom builds.
*
* @method Phaser.Loader.LoaderPlugin#json
* @fires Phaser.Loader.Events#ADD
* @since 3.0.0
*
* @param {(string|Phaser.Types.Loader.FileTypes.JSONFileConfig|Phaser.Types.Loader.FileTypes.JSONFileConfig[])} key - The key to use for this file, or a file configuration object, or array of them.
* @param {(object|string)} [url] - The absolute or relative URL to load this file from. If undefined or `null` it will be set to `<key>.json`, i.e. if `key` was "alien" then the URL will be "alien.json". Or, can be a fully formed JSON Object.
* @param {string} [dataKey] - When the JSON file loads only this property will be stored in the Cache.
* @param {Phaser.Types.Loader.XHRSettingsObject} [xhrSettings] - An XHR Settings configuration object. Used in replacement of the Loaders default XHR Settings.
*
* @return {this} The Loader instance.
*/
FileTypesManager.register('json', function (key, url, dataKey, xhrSettings)
{
if (Array.isArray(key))
{
for (var i = 0; i < key.length; i++)
{
// If it's an array it has to be an array of Objects, so we get everything out of the 'key' object
this.addFile(new JSONFile(this, key[i]));
}
}
else
{
this.addFile(new JSONFile(this, key, url, xhrSettings, dataKey));
}
return this;
});
module.exports = JSONFile;