JSONPath for PHP 7.1+

This is a JSONPath implementation for PHP based on Stefan Goessner's JSONPath script.

JSONPath is an XPath-like expression language for filtering, flattening and extracting data.

This project aims to be a clean and simple implementation with the following goals:

• Object-oriented code (should be easier to manage or extend in future)
• Expressions are parsed into tokens using code inspired by the Doctrine Lexer. The tokens are cached internally to avoid re-parsing the expressions.
• There is no eval() in use
• Any combination of objects/arrays/ArrayAccess-objects can be used as the data input which is great if you're de-serializing JSON in to objects or if you want to process your own data structures.

Installation

composer require softcreatr/jsonpath:"^0.5 || ^0.7"

JSONPath Examples

JSONPath	Result
$.store.books[*].author	the authors of all books in the store
$..author	all authors
$.store..price	the price of everything in the store.
$..books[2]	the third book
$..books[(@.length-1)]	the last book in order.
$..books[-1:]	the last book in order.
$..books[0,1]	the first two books
$..books[:2]	the first two books
$..books[::2]	every second book starting from first one
$..books[1:6:3]	every third book starting from 1 till 6
$..books[?(@.isbn)]	filter all books with isbn number
$..books[?(@.price<10)]	filter all books cheaper than 10
$..*	all elements in the data (recursively extracted)

Expression syntax

Symbol	Description
$	The root object/element (not strictly necessary)
@	The current object/element
. or []	Child operator
..	Recursive descent
*	Wildcard. All child elements regardless their index.
[,]	Array indices as a set
[start:end:step]	Array slice operator borrowed from ES4/Python.
?()	Filters a result set by a script expression
()	Uses the result of a script expression as the index

PHP Usage

Using arrays

use Flow\JSONPath\JSONPath;

$data = ['people' => [
    ['name' => 'Sascha'],
    ['name' => 'Bianca'],
    ['name' => 'Alexander'],
    ['name' => 'Maximilian'],
]];

print_r((new JSONPath($data))->find('$.people.*.name')->getData());

/*
Array
(
    [0] => Sascha
    [1] => Bianca
    [2] => Alexander
    [3] => Maximilian
)
*/

Using objects

use Flow\JSONPath\JSONPath;

$data = json_decode('{"name":"Sascha Greuel","birthdate":"1987-12-16","city":"Gladbeck","country":"Germany"}', false);

print_r((new JSONPath($data))->find('$')->getData()[0]);

/*
stdClass Object
(
    [name] => Sascha Greuel
    [birthdate] => 1987-12-16
    [city] => Gladbeck
    [country] => Germany
)
*/

More examples can be found in the Wiki

Magic method access

The options flag JSONPath::ALLOW_MAGIC will instruct JSONPath when retrieving a value to first check if an object has a magic __get() method and will call this method if available. This feature is iffy and not very predictable as:

• wildcard and recursive features will only look at public properties and can't smell which properties are magically accessible
• there is no property_exists check for magic methods so an object with a magic __get() will always return true when checking if the property exists
• any errors thrown or unpredictable behaviour caused by fetching via __get() is your own problem to deal with

use Flow\JSONPath\JSONPath;

$myObject = (new Foo())->get('bar');
$jsonPath = new JSONPath($myObject, JSONPath::ALLOW_MAGIC);

For more examples, check the JSONPathTest.php tests file.

Script expressions

Script expressions are not supported as the original author intended because:

• This would only be achievable through eval (boo).
• Using the script engine from different languages defeats the purpose of having a single expression evaluate the same way in different languages which seems like a bit of a flaw if you're creating an abstract expression syntax.

So here are the types of query expressions that are supported:

[?(@._KEY_ _OPERATOR_ _VALUE_)] // <, >, <=, >=, !=, ==, =~, in and nin
e.g.
[?(@.title == "A string")] //
[?(@.title = "A string")]
// A single equals is not an assignment but the SQL-style of '=='
[?(@.title =~ /^a(nother)? string$/i)]
[?(@.title in ["A string", "Another string"])]
[?(@.title nin ["A string", "Another string"])]

Known issues

• This project has not implemented multiple string indexes e.g. $[name,year] or $["name","year"]. I have no ETA on that feature, and it would require some re-writing of the parser that uses a very basic regex implementation.

Similar projects

FlowCommunications/JSONPath is the predecessor of this library by Stephen Frank

Other / Similar implementations can be found in the Wiki.

Changelog

A list of changes can be found in the CHANGELOG.md file.

License

MIT

Contributors ✨

Sascha Greuel

Sergey

Oleg Andreyev