2021-12-02 13:27:13 +01:00

193 lines
5.4 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 { ActivatedRoute, ActivatedRouteSnapshot, Params } from '@angular/router';
import { CoreNavigationOptions, CoreNavigator } from '@services/navigator';
import { CoreItemsManagerSource } from './items-manager-source';
import { CoreItemsManagerSourcesTracker } from './items-manager-sources-tracker';
/**
* Helper to manage a collection of items in a page.
*/
export abstract class CoreItemsManager<Item = unknown, Source extends CoreItemsManagerSource<Item> = CoreItemsManagerSource<Item>> {
protected source?: { instance: Source; unsubscribe: () => void };
protected itemsMap: Record<string, Item> | null = null;
protected selectedItem: Item | null = null;
constructor(source: Source) {
this.setSource(source);
}
/**
* Get source.
*
* @returns Source.
*/
getSource(): Source {
if (!this.source) {
throw new Error('Source is missing from items manager');
}
return this.source.instance;
}
/**
* Set source.
*
* @param newSource New source.
*/
setSource(newSource: Source | null): void {
if (this.source) {
CoreItemsManagerSourcesTracker.removeReference(this.source.instance, this);
this.source.unsubscribe();
delete this.source;
this.onSourceReset();
}
if (newSource) {
CoreItemsManagerSourcesTracker.addReference(newSource, this);
this.source = {
instance: newSource,
unsubscribe: newSource.addListener({
onItemsUpdated: items => this.onSourceItemsUpdated(items),
onReset: () => this.onSourceReset(),
}),
};
const items = newSource.getItems();
if (items) {
this.onSourceItemsUpdated(items);
}
}
}
/**
* Process page destroyed operations.
*/
destroy(): void {
this.setSource(null);
}
/**
* Get page route.
*
* @returns Current page route, if any.
*/
protected abstract getCurrentPageRoute(): ActivatedRoute | null;
/**
* Get the path to use when navigating to an item page.
*
* @param item Item.
* @return Path to use when navigating to the item page.
*/
protected abstract getItemPath(item: Item): string;
/**
* Get the path of the selected item.
*
* @param route Page route, if any.
* @return Path of the selected item.
*/
protected abstract getSelectedItemPath(route?: ActivatedRouteSnapshot | null): string | null;
/**
* Get the query parameters to use when navigating to an item page.
*
* @param item Item.
* @return Query parameters to use when navigating to the item page.
*/
// eslint-disable-next-line @typescript-eslint/no-unused-vars
protected getItemQueryParams(item: Item): Params {
return {};
}
/**
* Update the selected item given the current route.
*
* @param route Current route.
*/
protected updateSelectedItem(route: ActivatedRouteSnapshot | null = null): void {
route = route ?? this.getCurrentPageRoute()?.snapshot ?? null;
const selectedItemPath = this.getSelectedItemPath(route);
this.selectedItem = selectedItemPath
? this.itemsMap?.[selectedItemPath] ?? null
: null;
}
/**
* Navigate to an item in the collection.
*
* @param item Item.
* @param options Navigation options.
*/
protected async navigateToItem(
item: Item,
options: Pick<CoreNavigationOptions, 'reset' | 'replace' | 'animationDirection'> = {},
): Promise<void> {
// Get current route in the page.
const route = this.getCurrentPageRoute();
if (route === null) {
return;
}
// If this item is already selected, do nothing.
const itemPath = this.getItemPath(item);
const selectedItemPath = this.getSelectedItemPath(route.snapshot);
if (selectedItemPath === itemPath) {
return;
}
// Navigate to item.
const params = this.getItemQueryParams(item);
const pathPrefix = selectedItemPath ? selectedItemPath.split('/').fill('../').join('') : '';
await CoreNavigator.navigate(pathPrefix + itemPath, { params, ...options });
}
/**
* Called when source items have been updated.
*
* @param items New items.
*/
protected onSourceItemsUpdated(items: Item[]): void {
this.itemsMap = items.reduce((map, item) => {
map[this.getItemPath(item)] = item;
return map;
}, {});
this.updateSelectedItem();
}
/**
* Called when source has been updated.
*/
protected onSourceReset(): void {
this.itemsMap = null;
this.selectedItem = null;
}
}