Skip to content

supermetrics-public/pecl-jsonpath

Repository files navigation

JsonPath-PHP - extension for PHP 8.0+

Build status Code coverage

JSONPath is a language for querying and extracting data from JSON, similar to XPath for XML.

This PHP extension for JSONPath is inspired by Stefan Goessner's original implementation and is intended to be a fast(er) replacement for JSONPath libraries written in PHP.

Intended audience

This extension is ideal for projects that depend heavily on JSONPath and could benefit from a native C implementation. Other JSONPath implementations often rely on eval() and regular expressions, while JsonPath-PHP is a more efficient lexer/parser. Extracting the data in C rather than in PHP results in great performance. In fact, JsonPath-PHP is often faster than manually traversing the array in PHP and picking the matching element(s).

The tradeoff for increased performance is the overhead of adding this extension to your PHP installation. If you're running your PHP application in a shared environment where you can't install PHP extensions, we recommend checking out more convenient PHP implementations like this, this, and this. Or switching to an environment that you have more control over. 😉

Installation

Linux and macOS

Option 1: Build using PECL

$ pecl install jsonpath

For more instructions on how to use PECL, see the PECL documentation.

Option 2: Build manually

Clone this repository to the directory of your choice, then run:

$ phpize
$ ./configure --enable-jsonpath
$ make
$ TEST_PHP_ARGS="-q" make test
$ sudo make install

Enable the extension

$ sudo touch /etc/php.d/jsonpath.ini
$ echo "extension=jsonpath.so" | sudo tee /etc/php.d/jsonpath.ini
$ php -m | grep jsonpath

If you're running PHP with the PHP-FPM service, restart it for the changes to take effect:

$ sudo service php-fpm restart

Windows

For pre-built Windows DLLs, see the PHP Extensions Repository.

Remember to add extension=jsonpath to your php.ini in order to enable the extension.

For more instructions on installing PHP extensions, see the PECL documentation.

Usage

<?php

use JsonPath\JsonPath;
use JsonPath\JsonPathException;

$jsonPath = new JsonPath();

try {
    // Query a data array using a JSONPath expression string.
    // Returns an array of matching elements, or false if nothing was found.
    $result = $jsonPath->find($data, $selector);
} catch (JsonPathException $exception) {
    echo $exception->getMessage(); // Usually a syntax error in the selector
}

Examples

<?php

$json = <<<JSON
{ "store": {
    "book": [ 
      { "category": "reference",
        "author": "Nigel Rees",
        "title": "Sayings of the Century",
        "price": 8.95
      },
      { "category": "fiction",
        "author": "Evelyn Waugh",
        "title": "Sword of Honour",
        "price": 12.99
      },
      { "category": "fiction",
        "author": "Herman Melville",
        "title": "Moby Dick",
        "isbn": "0-553-21311-3",
        "price": 8.99
      },
      { "category": "fiction",
        "author": "J. R. R. Tolkien",
        "title": "The Lord of the Rings",
        "isbn": "0-395-19395-8",
        "price": 22.99
      }
    ],
    "bicycle": {
      "color": "red",
      "price": 19.95
    }
  }
}
JSON;

$data = json_decode($json, true);

$jsonPath = new \JsonPath\JsonPath();

echo "Example 1: - The authors of all books in the store: \n";
echo json_encode($jsonPath->find($data, "$.store.book[*].author"), JSON_PRETTY_PRINT);
echo "\n\n";
/*
[
    "Nigel Rees",
    "Evelyn Waugh",
    "Herman Melville",
    "J. R. R. Tolkien"
]
*/

echo "Example 2 - All authors:\n";
echo json_encode($jsonPath->find($data, "$..author"), JSON_PRETTY_PRINT);
echo "\n\n";
/*
[
    "Nigel Rees",
    "Evelyn Waugh",
    "Herman Melville",
    "J. R. R. Tolkien"
]
*/

echo "Example 3 - All things in the store:\n";
echo json_encode($jsonPath->find($data, "$.store.*"), JSON_PRETTY_PRINT);
echo "\n\n";
/*
[
    [
        {
            "category": "reference",
            "author": "Nigel Rees",
            "title": "Sayings of the Century",
            "price": 8.95
        },
        {
            "category": "fiction",
            "author": "Evelyn Waugh",
            "title": "Sword of Honour",
            "price": 12.99
        },
        {
            "category": "fiction",
            "author": "Herman Melville",
            "title": "Moby Dick",
            "isbn": "0-553-21311-3",
            "price": 8.99
        },
        {
            "category": "fiction",
            "author": "J. R. R. Tolkien",
            "title": "The Lord of the Rings",
            "isbn": "0-395-19395-8",
            "price": 22.99
        }
    ],
    {
        "color": "red",
        "price": 19.95
    }
]
*/

echo "Example 4 - The price of everything in the store:\n";
echo json_encode($jsonPath->find($data, "$.store..price"), JSON_PRETTY_PRINT);
echo "\n\n";
/*
[
    8.95,
    12.99,
    8.99,
    22.99,
    19.95
]
*/

echo "Example 5 - The third book:\n";
echo json_encode($jsonPath->find($data, "$..book[2]"), JSON_PRETTY_PRINT);
echo "\n\n";
/*
[
    {
        "category": "fiction",
        "author": "Herman Melville",
        "title": "Moby Dick",
        "isbn": "0-553-21311-3",
        "price": 8.99
    }
]
*/

echo "Example 6 - The title of the last book:\n";
echo json_encode($jsonPath->find($data, "$..book[-1].title"), JSON_PRETTY_PRINT);
echo "\n\n";
/*
[
    "The Lord of the Rings"
]
*/

echo "Example 7 - Lookup by ISBN:\n";
echo json_encode($jsonPath->find($data, "$.store.book[?(@.isbn == '0-395-19395-8')]"), JSON_PRETTY_PRINT);
echo "\n\n";
/*
[
    {
        "category": "fiction",
        "author": "J. R. R. Tolkien",
        "title": "The Lord of the Rings",
        "isbn": "0-395-19395-8",
        "price": 22.99
    }
]
*/

echo "Example 8 - Lookup by category and price:\n";
echo json_encode($jsonPath->find($data, "$.store.book[?(@.category == 'fiction' && @.price <= 15.00)]"), JSON_PRETTY_PRINT);
echo "\n\n";
/*
[
    {
        "category": "fiction",
        "author": "Evelyn Waugh",
        "title": "Sword of Honour",
        "price": 12.99
    },
    {
        "category": "fiction",
        "author": "Herman Melville",
        "title": "Moby Dick",
        "isbn": "0-553-21311-3",
        "price": 8.99
    }
]
*/

echo "Example 9 - Lookup by author using regular expression:\n";
echo json_encode($jsonPath->find($data, "$.store.book[?(@.author =~ /Tolkien$/)]"), JSON_PRETTY_PRINT);
echo "\n\n";
/*
[
    {
        "category": "fiction",
        "author": "J. R. R. Tolkien",
        "title": "The Lord of the Rings",
        "isbn": "0-395-19395-8",
        "price": 22.99
    }
]
*/

echo "Example 10 - The titles of books without an ISBN:\n";
echo json_encode($jsonPath->find($data, "$.store.book[?(!@.isbn)].title"), JSON_PRETTY_PRINT);
echo "\n\n";
/*
[
    "Sayings of the Century",
    "Sword of Honour"
]
*/

JSONPath expression syntax

Notation Description
$ References the root element.
@ References the current element. Often used in filter expressions.
.property Picks the child element with the given property name, using dot notation.
["property"] Picks the child element with the given property name, using bracket notation. Use this when the property name contains special characters.
[n] Picks the array element at index n. Use a negative index to count from the end of the array.
[start:end:step] Picks every step array elements from index start to index end, end exclusive. Use negative indexes to count from the end of the array, -1 denoting the last item. Examples:
  • $.list[0:3] - Takes the first three elements
  • $.list[1:] - Leaves out the first element
  • $.list[1:-1] - Leaves out the first and last elements
  • $.list[::2] - Takes every second element
["property1", "property2"] Picks the given properties from an array.
* Picks all elements in an array.
..property Recursively picks all elements with the given property name.
[?(expression)] Picks all elements in an array that match the given filter. Use @ to reference the current element. Supported filter operators:
  • ==: Equals
  • !=: Does not equal
  • =~ /REGEX/: Matches the given regular expression REGEX
  • >: Is greater than
  • >=: Is greater than or equal to
  • <: Is less than
  • <=: Is less than or equal to
  • !: Negation
  • &&: AND
  • ||: OR

Also see the examples.

Performance benchmarks

Chart showing a performance comparison between JsonPath-PHP, native PHP (JsonPath-PHP sometimes faster, sometimes slower), and the fastest tested PHP library (JsonPath-PHP always faster)

The numbers in the chart were obtained when running the benchmark suite in PHP 8.1 with OPcache and JIT enabled.

If you want to run benchmarks yourself, have a look at the jsonpath-benchmark repo.

License

JsonPath-PHP is open-sourced software licensed under the PHP License 3.01.

Tests

The unit tests utilize PHP's core and extension testing framework. The recommended way to run the tests is:

$ TEST_PHP_ARGS="-q" make test

JsonPath-PHP implements the JSONPath Comparison test suite. These tests reside in the tests/comparison_* directories.

To generate a code coverage report, install lcov and build the extension with the special --enable-code-coverage flag, before running the tests and processing the code coverage output:

$ ./configure --enable-jsonpath --enable-code-coverage
$ make clean
$ TEST_PHP_ARGS="-q" make test
$ make lcov

You can then find a coverage report in the lcov_html/ directory.

Code Quality Tooling

Please run the code formatter and linter (and fix any issues reported by the linter) before filing a pull request.

You may check the code format and linter automatically before committing by setting up a pre-commit hook:

make setup-pre-commit

Formatting

Code formatting requires clang-format.

make format-code

Linting

Linting requires cppcheck.

make lint-code

Contributors

JsonPath-PHP is created by Mike Kaminski and maintained by Supermetrics and Mike Kaminski.

Found a bug, or missing some feature? Raise an issue or submit a pull request.