35 lines
1.6 KiB
JavaScript
35 lines
1.6 KiB
JavaScript
/**
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* @license
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* Copyright 2021 Google LLC
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* SPDX-License-Identifier: BSD-3-Clause
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*/
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/**
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* An event fired by a context requester to signal it desires a specified context with the given key.
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*
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* A provider should inspect the `context` property of the event to determine if it has a value that can
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* satisfy the request, calling the `callback` with the requested value if so.
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*
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* If the requested context event contains a truthy `subscribe` value, then a provider can call the callback
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* multiple times if the value is changed, if this is the case the provider should pass an `unsubscribe`
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* method to the callback which consumers can invoke to indicate they no longer wish to receive these updates.
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*
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* If no `subscribe` value is present in the event, then the provider can assume that this is a 'one time'
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* request for the context and can therefore not track the consumer.
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*/
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export class ContextRequestEvent extends Event {
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/**
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*
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* @param context the context key to request
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* @param contextTarget the original context target of the requester
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* @param callback the callback that should be invoked when the context with the specified key is available
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* @param subscribe when, true indicates we want to subscribe to future updates
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*/
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constructor(context, contextTarget, callback, subscribe) {
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super('context-request', { bubbles: true, composed: true });
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this.context = context;
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this.contextTarget = contextTarget;
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this.callback = callback;
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this.subscribe = subscribe ?? false;
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}
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}
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//# sourceMappingURL=context-request-event.js.map
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