130 lines
4.6 KiB
TypeScript

// (C) Copyright 2015 Moodle Pty Ltd.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
import { Component, Input, OnInit, OnChanges, SimpleChange, ViewChild, ElementRef, AfterViewInit } from '@angular/core';
import { CoreEventLoadingChangedData, CoreEvents } from '@singletons/events';
import { CoreUtils } from '@services/utils/utils';
import { CoreAnimations } from '@components/animations';
import { Translate } from '@singletons';
import { CoreComponentsRegistry } from '@singletons/components-registry';
import { CorePromisedValue } from '@classes/promised-value';
import { AsyncComponent } from '@classes/async-component';
/**
* Component to show a loading spinner and message while data is being loaded.
*
* It will show a spinner with a message and hide all the content until 'hideUntil' variable is set to a truthy value (!!hideUntil).
* If 'message' isn't set, default message "Loading" is shown.
* 'message' attribute accepts hardcoded strings, variables, filters, etc. E.g. [message]="'core.loading' | translate".
*
* Usage:
* <core-loading [message]="loadingMessage" [hideUntil]="dataLoaded">
* <!-- CONTENT TO HIDE UNTIL LOADED -->
* </core-loading>
*
* IMPORTANT: Due to how ng-content works in Angular, the content of core-loading will be executed as soon as your view
* is loaded, even if the content hidden. So if you have the following code:
* <core-loading [hideUntil]="dataLoaded"><my-component></my-component></core-loading>
*
* The component "my-component" will be initialized immediately, even if dataLoaded is false, but it will be hidden. If you want
* your component to be initialized only if dataLoaded is true, then you should use ngIf:
* <core-loading [hideUntil]="dataLoaded"><my-component *ngIf="dataLoaded"></my-component></core-loading>
*/
@Component({
selector: 'core-loading',
templateUrl: 'core-loading.html',
styleUrls: ['loading.scss'],
animations: [CoreAnimations.SHOW_HIDE],
})
export class CoreLoadingComponent implements OnInit, OnChanges, AfterViewInit, AsyncComponent {
@Input() hideUntil: unknown; // Determine when should the contents be shown.
@Input() message?: string; // Message to show while loading.
@Input() fullscreen = true; // Use the whole screen.
@ViewChild('content') content?: ElementRef;
uniqueId: string;
protected element: HTMLElement; // Current element.
loaded = false; // Only comes true once.
protected onReadyPromise = new CorePromisedValue<void>();
constructor(element: ElementRef) {
this.element = element.nativeElement;
CoreComponentsRegistry.register(this.element, this);
// Calculate the unique ID.
this.uniqueId = 'core-loading-content-' + CoreUtils.getUniqueId('CoreLoadingComponent');
}
/**
* @inheritdoc
*/
ngOnInit(): void {
if (!this.message) {
// Default loading message.
this.message = Translate.instant('core.loading');
}
this.element.classList.toggle('core-loading-inline', !this.fullscreen);
}
/**
* @inheritdoc
*/
ngAfterViewInit(): void {
this.changeState(!!this.hideUntil);
}
/**
* @inheritdoc
*/
ngOnChanges(changes: { [name: string]: SimpleChange }): void {
if (changes.hideUntil) {
this.changeState(!!this.hideUntil);
}
}
/**
* Change loaded state.
*
* @param loaded True to load, false otherwise.
* @return Promise resolved when done.
*/
async changeState(loaded: boolean): Promise<void> {
this.element.classList.toggle('core-loading-loaded', loaded);
this.content?.nativeElement.classList.toggle('core-loading-content', loaded);
if (!this.loaded && loaded) {
this.loaded = true; // Only comes true once.
this.onReadyPromise.resolve();
}
// Event has been deprecated since app 4.0.
CoreEvents.trigger(CoreEvents.CORE_LOADING_CHANGED, <CoreEventLoadingChangedData> {
loaded: true,
uniqueId: this.uniqueId,
});
}
/**
* @inheritdoc
*/
async ready(): Promise<void> {
return await this.onReadyPromise;
}
}