sortable-object-hash

Based on an array path and a sort order for each property, generate a hash string for an object that will sort accordingly.

Example

var sortableHash = require('sortable-object-hash')
var order = {
  str: ['a','b','c'],
  num: ['1','2','3']
}

var sortable = sortableHash(['str','num'], order)

sortable.hash({str:'a', num:'1'})
// a042000000000000000070c3bf0042000000000000000000
sortable.hash({str:'c', num:'2'})
// a042400000000000000070c3bf00423ff000000000000000
sortable.hash({str:'z', num:'3'})
// a070c3be0070c3bf0042400000000000000000

sortable.hash({str:['a','b'], num:'3'})
// a0420000000000000000423ff000000000000070c3bf0042400000000000000000
sortable.hash({str:['a','c']})
// a042000000000000000042400000000000000070c3bf0070c3be0000

Usage

var sortable = sortableHash(path, order, interpolated={}, opts={})

Returns a new hash function that takes objects and returns a string that will sort in the order defined by path and order.

path

An array of keys each key can be a string or an array. Each key produces a section of the hash. Key strings will be interpolated with single {mustaches} from the object's properties.

order

An object mapping keys to arrays of keys in the desired sort order.

interpolate

An object mapping keys to arrays of keys in the desired sort order.

var order = {
  str: ['a','b','c'],
  num: ['1','2','3']
}
var interpolated = {
  first: ['x','y','z']
}
// interpolated key: {interpolated[object[thisValue]]}.objectProperty
var sortable = sortableHash(['{key}.val','str','num'], order, interpolated)

sortable.hash({key: 'first', val: 'z', str:'a', num:'1'})
// a042400000000000000070c3bf0042000000000000000070c3bf0042000000000000000000

opts

• opts.empty = '\xfe' the index to assign to properties not found in the sort order. set higher than the max data index to place empty items after. set to -1 to place empty properties before.
• opts.separator = '\xff' the index to assign separation of keys. must be larger than max data index and opts.empty
• opts.delimiter = '.' the delimiter to used for splitting interpolated keys.

sortable.hash(obj)

Return a sortable hash string.

sortable.array(obj)

Return the array of indexes that will be passed to bytewise to generate a hash.

License

MIT