utils-deep-set

1.0.1 • Public • Published

Deep Set

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Deep set a nested property.

Installation

$ npm install utils-deep-set

For use in the browser, use browserify.

Usage

var deepSet = require( 'utils-deep-set' );

deepSet( obj, path, value[, options] )

Deep set a nested property.

var obj = { 'a': { 'b': { 'c': 'd' } } };
 
var bool = deepSet( obj, 'a.b.c', 'beep' );
/*
    { 'a': { 'b': { 'c': 'beep' } } }
*/

If the function is able to deep set a nested property, the function returns true; otherwise, the function returns false.

var bool = deepSet( obj, 'a.b.c', 'woot' );
// returns true
 
bool = deepSet( obj, 'a.beep.c', 'boop' );
// returns false
 
bool = deepSet( null, 'a.beep.c', 'boop' );
// returns false
 
bool = deepSet( 'bap', 'a.beep.c', 'boop' );
// returns false

For paths including arrays, specify the numeric index.

var arr = [
    { 'a': [ {'x': 5} ] },
    { 'a': [ {'x': 10} ] }
];
 
var bool = deepSet( arr, '1.a.0.x', 25 );
/*
    [
        { 'a': [ {'x': 5} ] },
        { 'a': [ {'x': 25} ] }
    ]
*/

The key path may be specified as either a delimited string or a key array.

var obj = { 'a': { 'b': { 'c': 'd' } } };
 
var bool = deepSet( obj, ['a','b','c'], 'beep' );
/*
    { 'a': { 'b': { 'c': 'beep' } } }
*/

If value is a function, the argument is treated as a callback and should return a value to set.

function set( val ) {
    var ch = val;
    for ( var i = 0; i < 4; i++ ) {
        val += ch;
    }
    return val;
}
var obj = { 'a': { 'b': { 'c': 'd' } } };
 
var bool = deepSet( obj, 'a.b.c', set );
/*
    { 'a': { 'b': { 'c': 'ddddd' } } }
*/

The function accepts the following options:

  • sep: key path separator. Default: '.'.
  • create: boolean indicating whether to create a path if the key path does not already exist. Default: false.

By default, the function assumes dot separated key values. To specify an alternative separator, set the sep option.

var obj = { 'a': { 'b': { 'c': 'd' } } };
 
var bool = deepSet( obj, 'a/b/c', 'beep', {
    'sep': '/'
});
/*
    { 'a': { 'b': { 'c': 'beep' } } }
*/

To create a key path which does not already exist, set the create option to true.

var bool = deepSet( obj, 'a.e.c', 'boop', {
    'create': true
});
/*
    { 
        'a': { 
            'b': {
                'c': 'beep'
            }, 
            'e': {
                'c': 'boop'
            } 
        }
    }
*/

deepSet.factory( path[, options] )

Creates a reusable deep set factory. The factory method ensures a deepSet function is configured identically by using the same set of provided options.

var dset = deepSet.factory( 'a/b/c', {
    'create': true,
    'sep': '/'
});

dset( obj, value )

Deep sets a nested property.

var obj = { 'a': { 'b': { 'c': 'd' } } };
 
var bool = dset( obj, 'beep' );
/*
    { 'a': { 'b': { 'c': 'beep' } } }
*/

Examples

var deepSet = require( 'utils-deep-set' );
 
var data,
    bool,
    keys,
    i;
 
function set( val ) {
    return val * 10;
}
 
data = new Array( 100 );
for ( i = 0; i < data.length; i++ ) {
    data[ i ] = {
        'x': Date.now(),
        'y': [ Math.random(), Math.random(), i ]
    };
}
 
keys = [ 0, 'y', 2 ];
for ( i = 0; i < data.length; i++ ) {
    keys[ 0 ] = i;
    bool = deepSet( data, keys, set );
    if ( !bool ) {
        console.error( 'Unable to deep set value.' );
    }
}
console.log( data );

To run the example code from the top-level application directory,

$ node ./examples/index.js

Tests

Unit

Unit tests use the Mocha test framework with Chai assertions. To run the tests, execute the following command in the top-level application directory:

$ make test

All new feature development should have corresponding unit tests to validate correct functionality.

Test Coverage

This repository uses Istanbul as its code coverage tool. To generate a test coverage report, execute the following command in the top-level application directory:

$ make test-cov

Istanbul creates a ./reports/coverage directory. To access an HTML version of the report,

$ make view-cov

License

MIT license.

Copyright

Copyright © 2015. Athan Reines.

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Version

1.0.1

License

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