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    array-keys

    2.3.1 • Public • Published

    array-keys

    Build Status Code Climate license downloads release

    Very simple library to manage array elements using a key instead of array index position. When dealing with very large sets of data all organized in an object reference, if the object structure is changing a lot you can end up with memory leaks and slow performance. In these cases it's better to keep an array of objects instead of and object of objects. The cost of iterating through the array is cheaper than the lack of garbage collection which can occur in large, changing, object hashes.

    environments

    Should run in both node.js and browser environments.

    basic usage example

    var ak = new ArrayKeys({
      identifier: 'key' // defaults to `id`
    });
     
    ak.getRecord('myInvalidKey'}); // returns undefined
     
    ak.addRecord({
      key: 'myKey1',
      value: 'hello world!'
    }); // returns true
     
    ak.getRecord('myKey1'); // returns { key: 'myKey1', value: 'hello world!' }
     
    ak.addRecord({
      key: 'myKey2',
      value: 'hello space!'
    }); // returns true
     
     
    ak.forEachRecord(function (record) {
      // this function is called once for each record
    }).finally(function (count) {
      // function called after the above callback is called for each record
      // count is the total number of records processed
    });
     
    ak.getIdentifiers(); // returns ['myKey1', 'myKey2']

    events

    ArrayKeys also optionally supports emitting events. This functionality must be explicity enabled during object instantiation.

    supported events

    • add
    • remove
    • update

    example

    var ak = new ArrayKeys({
      emitEvents: true
    });
     
    ak.events.on('add', function (record) {
      console.log(record.id); // 'foobar'
    });
     
    ak.addRecord({
        id: 'foobar',
        here: [ 'is', 'some' ],
        data: true
    });
     

    API

    constructor

    var ak = new ArrayKeys({
      identifier: 'id',
      emitEvents: true
    });

    addRecord

    Add a new record.

    ak.addRecord({
      id: 'helloworld123',
      foo: 'bar'
    });
    ak.addRecord({
      id: 'pizza777',
      blah: [ 1, 2, 3 ]
    });

    getRecord

    Get a record by it's identifier.

    var record = ak.getRecord('helloworld123');

    getIdentifiers

    Get an array of the values of the record identifiers.

    var ids = ak.getIdentifiers(); // 'helloworld123', 'pizza777'

    exists

    Indicates whether a record exists by returning true or false.

    if (ak.exists('blahblahblah')) {
      console.log('yes!');
    } else {
      console.log('no');
    }
    // returns false, 'no'

    getIndex

    Returns the number of the position of the record, specified by identifier.

    var position = ak.getIndex('pizza777'); // returns 1

    forEachRecord

    Calls a callback handler function for each record in the list, asyncronously.

    ak.forEachRecord(function (record, index) {
      // ... do something with record
    }).finally(function (count) {
      // ... do something at the end of the operation. First param is the number
      // of items processed.
    })

    mapRecords

    Calls a callback transform function for each record in the list.
    Your original list is not mutated. Returns an array.

    ak.mapRecords(function(record, index) {
      return record.id + '-' + index;
    });

    removeRecord

    Removes the record specified by identifier.

    ak.removeRecord('helloworld123');

    removeAll

    Removes all records.

    ak.removeAll();

    events

    update

    ak.events.on('update', function (record){
      ...
    });

    add

    ak.events.on('add', function (record){
      ...
    });

    remove

    ak.events.on('remove', function (record){
      ...
    });

    credits

    Project developed and maintained by Nick Jennings

    Install

    npm i array-keys

    DownloadsWeekly Downloads

    33

    Version

    2.3.1

    License

    MIT

    Last publish

    Collaborators

    • silverbucket