Basic property selector. All subsequent operations will be based on this selector. If no selector present an error will be thrown

              
users.where('age').eq(30)
              
            

Nested properties can be selected using dot notation within a string

              
users.where('name.last').gte('B')
              
            

If you need to filter your data based on multiple properties you can chain them

              
users
    .where('age').gte(18)
    .where('isActive').isTruthy()
    .where('friends').range(2,20)
              
            

Unwraps DataField instance into an array. toArray() does the same job.

              users.toArray().map(user => user.age)
            

Selects entries where property exists. If no property value is passed then library tries to use the last selector

              
// this is okay:
users.where('email').exists()
// this is okay too:
users.exists('email')
// this will throw an error:
users.exists()
              
            

Selects entries where property exists and has truthy value.

              
users.has('email').where('age').gte(18).median()
// selects users who have their email added to the profile, 18 years or older and return the age median of such users
              
            

Returns Number entries from DataField object, starting from the first one. If value is not provided then returns one entry. If value is greater than amount of entries left - returns the rest of them

              
users.where('age').asc().take(10)
              
            

              
const users = new DataField(data)  // 12 entries in an array
firstFive = users.take(5) // indices 0 - 4
SecondFive = users.take(5) // indices 5 - 9
restOfUsers = users.take(5) // indices 9 - end of array
              
            

Returns Number random entries from DataField object. If value is not provided then returns one entry. Unlike take() method does not track its own history

              
users.takeRandom() // returns one random entry
              
            

Selects entries by condition. Currently supports Number, String, Date values

              
users
    .where('age').eq(42)
    .where('registered').gte(new Date("Jan 1 2017")).lte(new Date("Dec 31 2018"))
    .where('company').not('COMVOY')
              
            

Selects entries with truthy selector value (one that evaluates to true in Javascript)

              
users.where('isActive').isTruthy()
              
            

Selects entries with falsy selector value (one that evaluates to false in Javascript)

              
users.where('isActive').isFalsy()
              
            

Selects entries which array selectors include value Works similar to ES7 includes

              
users.where('tags').includes('nostrud')
              
            

Selects entries with selector's value within the given range.

Currently supports Number, String, Date, Array.length

              
const from = new Date("Feb 23 2014")
const to = new Date("May 12 2017")
users.where('registered').range(from, to)
              
            

Sorts entries based on config options

Config:

              
{
  by: 'property', // <-- selector. MANDATORY
  order: 'asc' / 'desc' // <-- sorting order. OPTIONAL
  type: 'num' / 'str' / 'date' // type of value. OPTIONAL
}
              
            

If type is not provided library will try to guess it. If you want to sort by date make sure to explicitly add that to the config, otherwise it will be treated as a string

              
users.where('age').gte(18).sort({by: "name.last", order: "desc"})
              
            

Sorts by selector in ascending / descending order

              
users.where('company').asc()
// or
users.where('age').desc()
              
            

Returns a result of mathematical operation on. Ignored, if selector is not of type Number. If strict parameter is set to false attempts to coerce types

              
users.where('isActive').isTruthy().sum('age') // 2083
users.where('isActive').isTruthy().sum('age', false) // 2107 – converted string to a number