value-store

value-store

Get/set values on hierarchy of objects.

For example, a hierarchy of configuration files could be turned into a 'value-store'. Then it can be queried for the closest key with a value, or, for all values for a key.

Note, I'm using this in nuc.

Install

npm install --save value-store

Usage

// require the package
var buildStore = require('value-store')

// we can provide an array of objects as the initial hierarchy
var initialValues = [
  { first: true, name:'first' },
  { second: true, name:'second' },
  { third: true, name:'third' }
]

// build the instance, provide the array of initial values
var values = buildStore(initialValues)

// Or:
var values = buildStore({ array: initialValues ] })

// outputs:  
values.count()       // 3
values.get('first')  // true
values.get('second') // true
values.get('third')  // true
values.has('third')  // true
values.get('name')   // first
values.all('name')   // [ 'first', 'second', 'third' ]
values.in('third')   // 2

values.get('first', 2) // false
values.info('second')  // { value:true, in:1, overridden:false }
values.info('name')    // { value:'first', in:0, overridden:false }
values.info('name', 1) // { value:'second', in:1, overridden:true }

values.source(0) // constructor
values.source(5) // undefined


// let's change it by setting other values in there

// this puts enabled:true into the first object.
values.set('enabled', true);

// this overrides the current value in the first object
values.set('name', 'primary');

// this overrides the current value in the third object
values.set('name', 'tertiary', 2);

// add an entirely new object as the last object
values.append({ name:'last', something: 'new'});

// add an entirely new object as the first object.
// this essentially overrides all the others.
values.prepend({ name:'overrider' });

// add values from a file (specify path)
values.append('./some/file.json');


// rerun the above series and the new output will be:

values.count()       // 6, was 3

values.get('name')   // 'overrider', was 'first'

// now: [ 'overrider', 'primary', 'second', 'tertiary', 'last' ]
// was: [ 'first', 'second', 'third' ]
values.all('name')

values.in('third')   // 3, was 2

// now: { value:true, in:2, overridden:false }
// was: { value:true, in:1, overridden:false }
values.info('second')

// now: { value:'overrider', in:0, overridden:false }
// was: { value:'first', in:0, overridden:false }
values.info('name')

// now: { value:'primary', in:1, overridden:true }
// was: { value:'second', in:1, overridden:true }
values.info('name', 1)

values.source(0) // prepend
values.source(5) // { file: './some/file.json' }


// others: shift() is like array.shift(). removes the first array element
var result = values.shift();
// is: {
//   removed: [
//      { /* the object with name='overrider' */ }
//   ]
// }
//

// others: pop() is like array.shift(). removes the last array element
result = values.pop();
// is: {
//   removed: [
//     { /* the object with name='overrider' */ }
//   ]
// }

// the result is an array because you can shift/pop more than one by
// specifying how many:
// this removes the first two
values.shift(2);

// this removes the last two
values.pop(2);
// so, now there are the 2 middle ones left.

// when a file is added via its path the path is recorded as its 'source'
values.append('./some/file.json');

// then, that object can be written back to its source.
// let's say the above append put that file as source 3 (4th in array).
// then this would write it back out
values.write(3);

// it will be written as json because the extension is .json
// to alter where it's written to and the format you may pass options:
values.write(3, { file: './some/other/file.ini' });

// the above will be written as an INI file because the extension is '.ini'.
// you may also specify the format:
values.write(3, { file: './other.conf', format:'ini' });
// JSON is the default format. INI is the alternate format.

(MIT License)(LICENSE)