1blankz7/php-object-query

Quering object graphs in PHP

Object Querying Library

This library allows you to query your object graph in a consistent way. You can use it to support object mapping and to generate data representation based on the requirements of external systems., _(*1)

Usage

Query and the QueryResolver are the two key components of the system. A resolver needs one or more queries and resolves these queries by processing them on a given object graph., _(*2)

<?php

use Lemonade\ObjectQuery\Query\Query;
use Lemonade\ObjectQuery\QueryResolver;
use Lemonade\ObjectQuery\Definition\Path;

$resolver = new QueryResolver(
    new Query('shipName', (new Path())->get('name'))
);

$resolver->resolve($someShip);
// ['shipName' => 'Millenium Falcon']

A query consists of a name which ends up being the key in the result and a definition., _(*3)

There are three main definitions in the system you can use. Path, Value and Composition., _(*4)

Value

The Value definition is a plain container which will return the given value., _(*5)

<?php

use Lemonade\ObjectQuery\Query\Query;
use Lemonade\ObjectQuery\QueryResolver;
use Lemonade\ObjectQuery\Definition\Value;

$resolver = new QueryResolver(
    new Query('two', new Value(2))
);

$resolver->resolve($someObject);
// ['two' => 2]

Composition

The Composition definition is a more flexible alternative to Value. It gives access to the current source., _(*6)

<?php

use Lemonade\ObjectQuery\Query\Query;
use Lemonade\ObjectQuery\QueryResolver;
use Lemonade\ObjectQuery\Definition\Composition;
use Lemonade\ObjectQuery\Source\ObjectSource;

$composition = new Composition(function(ObjectSource $source) {
    return $source->get('id');
});
$resolver = new QueryResolver(
    new Query('someKey', $composition)
);

$resolver->resolve($someObject);
// ['someKey' => 3000]

Path

Path is the most complex definition. You can deep walk into the graph, filter collections and transform leaves. Have a look into the tests to get an impression of the possibilities., _(*7)

<?php

use ObjectQuery\Query\Query;
use ObjectQuery\QueryResolver;
use ObjectQuery\Definition\Path;

$path = (new Path())->get('appearsIn')
    ->filter(new EpisodeFilter(Episode::EMPIRE))
    ->get('episode');
$resolver = new QueryResolver(new Query('episodes', $path));

$resolver->resolveArray($someObject);
// ['episode' => [1, 2]]