import defaultValue from "../Core/defaultValue.js";
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import defined from "../Core/defined.js";
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import DeveloperError from "../Core/DeveloperError.js";
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import when from "../ThirdParty/when.js";
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import MetadataSchema from "./MetadataSchema.js";
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import ResourceLoader from "./ResourceLoader.js";
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import ResourceLoaderState from "./ResourceLoaderState.js";
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/**
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* A {@link MetadataSchema} loader.
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* <p>
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* Implements the {@link ResourceLoader} interface.
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* </p>
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*
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* @alias MetadataSchemaLoader
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* @constructor
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* @augments ResourceLoader
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*
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* @param {Object} options Object with the following properties:
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* @param {Object} [options.schema] An object that explicitly defines a schema JSON. Mutually exclusive with options.resource.
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* @param {Resource} [options.resource] The {@link Resource} pointing to the schema JSON. Mutually exclusive with options.schema.
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* @param {String} [options.cacheKey] The cache key of the resource.
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*
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* @exception {DeveloperError} One of options.schema and options.resource must be defined.
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*
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* @private
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* @experimental This feature is using part of the 3D Tiles spec that is not final and is subject to change without Cesium's standard deprecation policy.
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*/
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export default function MetadataSchemaLoader(options) {
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options = defaultValue(options, defaultValue.EMPTY_OBJECT);
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var schema = options.schema;
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var resource = options.resource;
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var cacheKey = options.cacheKey;
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//>>includeStart('debug', pragmas.debug);
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if (defined(schema) === defined(resource)) {
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throw new DeveloperError(
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"One of options.schema and options.resource must be defined."
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);
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}
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//>>includeEnd('debug');
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this._schema = defined(schema) ? new MetadataSchema(schema) : undefined;
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this._resource = resource;
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this._cacheKey = cacheKey;
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this._state = ResourceLoaderState.UNLOADED;
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this._promise = when.defer();
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}
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if (defined(Object.create)) {
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MetadataSchemaLoader.prototype = Object.create(ResourceLoader.prototype);
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MetadataSchemaLoader.prototype.constructor = MetadataSchemaLoader;
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}
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Object.defineProperties(MetadataSchemaLoader.prototype, {
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/**
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* A promise that resolves to the resource when the resource is ready.
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*
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* @memberof MetadataSchemaLoader.prototype
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*
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* @type {Promise.<MetadataSchemaLoader>}
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* @readonly
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* @private
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*/
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promise: {
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get: function () {
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return this._promise.promise;
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},
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},
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/**
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* The cache key of the resource.
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*
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* @memberof MetadataSchemaLoader.prototype
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*
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* @type {String}
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* @readonly
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* @private
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*/
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cacheKey: {
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get: function () {
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return this._cacheKey;
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},
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},
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/**
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* The metadata schema object.
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*
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* @memberof MetadataSchemaLoader.prototype
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*
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* @type {MetadataSchema}
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* @readonly
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* @private
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*/
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schema: {
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get: function () {
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return this._schema;
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},
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},
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});
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/**
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* Loads the resource.
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* @private
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*/
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MetadataSchemaLoader.prototype.load = function () {
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if (defined(this._schema)) {
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this._promise.resolve(this);
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return;
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}
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loadExternalSchema(this);
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};
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function loadExternalSchema(schemaLoader) {
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var resource = schemaLoader._resource;
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schemaLoader._state = ResourceLoaderState.LOADING;
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resource
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.fetchJson()
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.then(function (json) {
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if (schemaLoader.isDestroyed()) {
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return;
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}
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schemaLoader._schema = new MetadataSchema(json);
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schemaLoader._state = ResourceLoaderState.READY;
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schemaLoader._promise.resolve(schemaLoader);
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})
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.otherwise(function (error) {
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if (schemaLoader.isDestroyed()) {
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return;
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}
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schemaLoader._state = ResourceLoaderState.FAILED;
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var errorMessage = "Failed to load schema: " + resource.url;
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schemaLoader._promise.reject(schemaLoader.getError(errorMessage, error));
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});
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}
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/**
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* Unloads the resource.
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* @private
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*/
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MetadataSchemaLoader.prototype.unload = function () {
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this._schema = undefined;
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};
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