Vmeda.Online/src/core/singletons/array.ts

112 lines
3.3 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.
/**
* Singleton with helper functions for arrays.
*/
export class CoreArray {
/**
* Check whether an array contains an item.
*
* @param arr Array.
* @param item Item.
* @returns Whether item is within the array.
* @deprecated since 4.1. Use arr.includes() instead.
*/
static contains<T>(arr: T[], item: T): boolean {
// eslint-disable-next-line no-console
console.warn('CoreArray.contains is deprecated and will be removed soon. Please use array \'includes\' instead.');
return arr.indexOf(item) !== -1;
}
/**
* Flatten the first dimension of a multi-dimensional array.
*
* @see https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/flat#reduce_and_concat
*
* @param arr Original array.
* @returns Flattened array.
* @deprecated since 4.4 Use Array.prototype.flat() instead.
*/
static flatten<T>(arr: T[][]): T[] {
// eslint-disable-next-line no-console
console.warn('CoreArray.flatten is deprecated and will be removed soon. Please use array \'flat\' instead.');
return arr.flat();
}
/**
* Obtain a new array without the specified item.
*
* @param arr Array.
* @param item Item to remove.
* @returns Array without the specified item.
*/
static withoutItem<T>(arr: T[], item: T): T[] {
const newArray = [...arr];
const index = arr.indexOf(item);
if (index !== -1) {
newArray.splice(index, 1);
}
return newArray;
}
/**
* Return an array without duplicate values.
*
* @param array The array to treat.
* @param [key] Key of the property that must be unique. If not specified, the whole entry.
* @returns Array without duplicate values.
*/
static unique<T>(array: T[], key?: string): T[] {
const unique = {}; // Use an object to make it faster to check if it's duplicate.
return array.filter(entry => {
const value = key ? entry[key] : entry;
if (value in unique) {
return false;
}
unique[value] = true;
return true;
});
}
/**
* Given an array of strings, return only the ones that match a regular expression.
*
* @param array Array to filter.
* @param regex RegExp to apply to each string.
* @returns Filtered array.
*/
static filterByRegexp(array: string[], regex: RegExp): string[] {
if (!array || !array.length) {
return [];
}
return array.filter((entry) => {
const matches = entry.match(regex);
return matches && matches.length;
});
}
}