ObjExp

Matches objects using object expressions.

Installation

npm install object-expression

Usage

The example bellow shows how to filter an array of objects using ObjExp.

var ObjExp = require('../');

var people = [
    {
        'name': 'Malcolm Reynolds', 'birth_year': 2468, 'aim': 'misbehave',
        'accessories': [{'name': 'floral bonnet', 'description': 'pretty'}],
    },
    {
        'name': 'Zoë Alleyne Washburne', 'birth_year': 2484,
        'occupation': 'smuggler'
    },
    {
        'name': 'Inara Serra',
        'occupation': 'companion'
    },
    {
        'name': 'Kaywinnet Lee Frye',
        'occupation': 'mechanic'
    },
    {
        'name': 'Hoban Washburne',
        'accessories': [{'name': 'allosaurus', 'description': 'evil laugh'}],
        'occupation': 'pilot'
    },
    {
        'name': 'Jayne Cobb',
        'accessories': [{'name': 'earflap hat', 'description': 'cunning'}, {'name': 'vera', 'description': 'very favorite gun'}],
        'occupation': 'public relations'
    },
    {
        'name': 'Derrial Book',
        'accessories': [{'name': 'book', 'description': 'broken'}],
        'occupation': 'Shepherd'
    },
    {
        'name': 'River Tam'
    },
    {
        'name': 'Simon Tam',
        'occupation': 'surgeon'
    }
];

var pattern = new ObjExp({ 'name': { '$regex': /mal.*/i }, 'birth_year': { '$gt': 2450, '$lt': 2475 } });
pattern.and({ 'aim': 'misbehave' });
pattern.or({ 'accessories': { '$any': { '$or': [{ 'name': 'floral bonnet' }, { 'name': 'earflap hat' }] } } });
pattern.or({ 'occupation': { '$in': ['companion', 'mechanic'] } });
pattern.and(ObjExp.not({ 'occupation': { '$in': ['reavers', 'public relations'] } }));

var matches = people.filter(pattern.test);
console.log(matches);

/*
output:

[ { name: 'Malcolm Reynolds',
    birth_year: 2468,
    aim: 'misbehave',
    accessories: [ [Object] ] },
  { name: 'Inara Serra', occupation: 'companion' },
  { name: 'Kaywinnet Lee Frye', occupation: 'mechanic' } ]

 */

API

new ObjExp([expression])

This creates and retuns a new ObjExp.

Static Methods

ObjExp.and(expressions)

Returns an expression that would be true if and only if all passed expressions are true.

ObjExp.or(expressions)

Returns an expression that would be true if at least one of the passed expressions is true.

ObjExp.not(expression)

Returns an expression that would be true if the passed expression is false.

ObjExp.test(value, operator, expression)

Tests if the value matches the expression using the operator.

Operators

$and(value, expressions)

Returns true if the value matches all expressions.

$or(value, expressions)

Returns true if the value matches at least one expression.

$not(value, expression)

Returns true if the value does not match the expression.

$eq(value, expression)

Returns true if the value is equal to the expression.

$gt(value, expression)

Returns true if the value is greater than the expression.

$gte(value, expression)

Returns true if the value is greater than or equal to the expression.

$lt(value, expression)

Returns true if the value is lesser than the expression.

$lte(value, expression)

Returns true if the value is lesser than or equal to the expression.

$in(value, array)

Returns true if the value is in the array.

$exists(value, expression)

Returns true if the value existance is reflected by the expression.

$regex(value, regex)

Returns true if the value matches the regular expression.

$all(value, expression)

Returns true if the value is an array with all elements matching the expression.

$any(value, expression)

Returns true if the value is an array with at least one element matching the expression.

$size(value, expression)

Returns true if the value is an array with length matching the expression.

Prototype Methods

ObjExp#and(expressions)

Modifies the ObjExp, matching if the current expression and all passed expressions is true.

ObjExp#or(expressions)

Modifies the ObjExp, matching if the current expression or at least one of the passed expressions is true.

ObjExp#test(value)

Tests if the value matches the expression using the operator.

TODO

• Tests
• Optimizations