@progress/kendo-angular-grid
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Kendo UI Grid for Angular - high performance data grid with paging, filtering, virtualization, CRUD, and more.
82 lines (81 loc) • 2.75 kB
JavaScript
/**-----------------------------------------------------------------------------------------
* Copyright © 2025 Progress Software Corporation. All rights reserved.
* Licensed under commercial license. See LICENSE.md in the project root for more information
*-------------------------------------------------------------------------------------------*/
/**
* @hidden
*
* Quick look-up structure for combinations of keys.
* Similar to the native JS Set, however, working with a couple of keys instead of with a single key.
* Supports both primitive keys and object keys (compared by reference).
*/
export class PairSet {
/**
* Gets the total number of X/Y key pairs.
*/
get size() {
return this.totalKeysCount;
}
/**
* Holds a set of Y keys for each defined X key.
* Each X key creates a map which holds a set of Y keys.
*
* Map { 1 => Set { 1, 2, 3 } } // pairs: [1, 1], [1, 2], [1, 3]
*/
keysX = new Map();
/**
* Count the each added or deleted key manually to avoid iterating over all items when calling `this.size`.
*/
totalKeysCount = 0;
constructor(items, keyXField, keyYField) {
if (items && keyXField && keyYField) {
items.forEach(item => this.add(item[keyXField], item[keyYField]));
}
}
/**
* Adds a couple of items identified as a combination.
*/
add(keyX, keyY) {
if (!this.keysX.has(keyX)) {
this.keysX.set(keyX, new Set());
}
if (!this.has(keyX, keyY)) {
this.keysX.get(keyX).add(keyY);
this.totalKeysCount += 1;
}
}
/**
* Adds a combination of a couple of items identified together.
*/
delete(keyX, keyY) {
if (this.has(keyX, keyY)) {
this.keysX.get(keyX).delete(keyY);
this.totalKeysCount -= 1;
}
}
/**
* Checks whether the defined combination is stored.
*/
has(keyX, keyY) {
return this.keysX.has(keyX) && this.keysX.get(keyX).has(keyY);
}
/**
* Clears all key combinations.
*/
clear() {
this.keysX.clear();
this.totalKeysCount = 0;
}
/**
* Converts the persisted data structure to an array of objects,
* using the provided field names for the object props.
*/
toArray(keyXField, keyYField) {
return Array.from(this.keysX).reduce((pairs, pair) => {
// Array.from(mapInstance) returns an array of arrays [[itemKey1, columnKeysSet1], [itemKey2, columnKeysSet2]]
const [keyX, keysY] = pair;
Array.from(keysY).forEach(keyY => pairs.push({ [keyXField]: keyX, [keyYField]: keyY }));
return pairs;
}, []);
}
}