README

Forked from mghoneimy/php-graphql-oqm with added Result Object functionality.

This package utilizes the introspection feature of GraphQL APIs to generate a set of classes that map to the structure of the API schema. The generated classes can then be used in a very simple and intuitive way to query the API server.

Interacting with GraphQL API's using PHP has never been easier!

New Features in This Fork

This fork adds Result Object functionality that allows you to:

Generate strongly-typed result objects from GraphQL schema
Hydrate these objects from API response arrays using fromArray() method
Hydrate objects from JSON strings using fromJson() method
Convert objects back to arrays using asArray() method
Automatic handling of date/time fields with Carbon
Recursive handling of nested objects

Installation

Run the following command to install the package using composer:

composer require fo3nix/php-graphql-oqm

Generating The Schema Objects

After installing the package, the first step is to generate the schema objects. This can be easily achieved by executing the following command:

php vendor/bin/generate_schema_objects

This script will retrieve the API schema types using the introspection feature in GraphQL, then generate the schema objects from the types, and save them in the schema_object directory in the root directory of the package. You can override the default write directory by providing the "Custom classes writing dir" value when running the command.

You can also specify all options via command line options:

php vendor/bin/generate_schema_objects \
    -u "https://graphql-pokemon.vercel.app/" \
    -h "Authorization" \
    -v "Bearer 123" \
    -d "customClassesWritingDirectory" \
    -n "Vendor\Custom\Namespace"

or if you prefer long arguments

php vendor/bin/generate_schema_objects \
    --url "https://graphql-pokemon.vercel.app/" \
    --authorization-header-name "Authorization" \
    --authorization-header-value "Bearer 123" \
    --directory "customClassesWritingDirectory" \
    --namespace "Vendor\Custom\Namespace"

Usage

Building and Running Queries

In all the examples below I'm going to use the super cool public Pokemon GraphQL API as an illustration.

Check out the API at: https://graphql-pokemon.now.sh/

And Github Repo: https://github.com/lucasbento/graphql-pokemon

After generating the schema objects for the public Pokemon API, we can easily query the API by using the RootQueryObject. Here's an example:

$rootObject = new RootQueryObject();
$rootObject
    ->selectPokemons((new RootPokemonsArgumentsObject())->setFirst(5))
        ->selectName()
        ->selectId()
        ->selectFleeRate()
        ->selectAttacks()
            ->selectFast()
                ->selectName();

What this query does is that it selects the first 5 pokemons returning their names, ids, flee rates, fast attacks with their names. Easy right!?

All what remains is that we actually run the query to obtain results:

$results = $client->runQuery($rootObject->getQuery());

For more on how to use the client class refer to:

Using Result Objects (New Feature)

The new Result Object functionality allows you to convert raw GraphQL query results into strongly-typed PHP objects:

// Step 1: Build the query (same as before)
$queryRoot = new RootQueryObject();
$pokemonQuery = $queryRoot
    ->selectPokemons((new RootPokemonsArgumentsObject())->setFirst(5))
    ->selectName()
    ->selectId()
    ->selectFleeRate();

// Step 2: Run the query and get results as array
$results = $client->runQuery($queryRoot->getQuery(), true); // true = get as array
$pokemonsData = $results->getData()['pokemons'];

// Step 3: Hydrate the raw array into Result Objects
$pokemons = array_map(function ($pokemonData) {
    return Pokemon::fromArray($pokemonData);
}, $pokemonsData);

// Step 4: Use the type-hinted objects!
foreach ($pokemons as $pokemon) {
    echo "Name: " . $pokemon->getName() . "\n";
    echo "ID: " . $pokemon->getId() . "\n";
    echo "Flee Rate: " . $pokemon->getFleeRate() . "\n";
    
    // Convert back to array if needed
    $pokemonArray = $pokemon->asArray();
}

// You can also hydrate from JSON
$pokemon = Pokemon::fromJson('{"name":"Pikachu","id":"025","fleeRate":0.1}');

Benefits of using Result Objects:

Full IDE autocompletion for all properties
Type safety with proper return type hints
Automatic handling of date/time fields with Carbon
Recursive handling of nested objects
Easy conversion between objects and arrays/JSON

Notes

A couple of notes about schema objects to make your life easier when using the generating classes:

Dealing With Object Selectors

Whilst scalar field setters return an instance of the current query object, object field selectors return objects of the nested query object. This means that setting the $rootObject reference to the result returned by an object selector means that the root query object reference is gone.

Don't:

$rootObject = (new RootQueryObject())->selectAttacks()->selectSpecial()->selectName();

This way you end up with reference to the PokemonAttackQueryObject, and the reference to the RootQueryObject is gone.

Do:

$rootObjet = new RootQueryObject();
$rootObject->selectAttacks()->selectSpecial()->selectName();

This way you can keep track of the RootQueryObject reference and develop your query safely.

Dealing With Multiple Object Selectors

Suppose we want to get the pokemon "Charmander", retrieve his evolutions, evolution requirements, and evolution requirements of his evolutions, how can we do that?

We can't do this:

$rootObject = new RootQueryObject();
$rootObject->selectPokemon(
    (new RootPokemonArgumentsObject())->setName('charmander')
)
    ->selectEvolutions()
        ->selectName()
        ->selectNumber()
        ->selectEvolutionRequirements()
            ->selectName()
            ->selectAmount()
    ->selectEvolutionRequirements()
        ->selectName()
        ->selectAmount();

This is because the reference is now pointing to the evolution requirements of the evolutions of charmander and not charmander himself.

The best way to do this is by structuring the query like this:

$rootObject = new RootQueryObject();
$charmander = $rootObject->selectPokemon(
    (new RootPokemonArgumentsObject())->setName('charmander')
);
$charmander->selectEvolutions()
    ->selectName()
    ->selectNumber()
    ->selectEvolutionRequirements()
        ->selectName()
        ->selectAmount();
$charmander->selectEvolutionRequirements()
    ->selectName()
    ->selectAmount();

This way we have kept the reference to charmander safe and constructed our query in an intuitive way.

Generally, whenever there's a branch off (just like in the case of getting evolutions and evolution requirements of the same object) the best way to do it is to structure the query like a tree, where the root of the tree becomes the reference to the object being branch off from. In this case, charmander is the root and evolutions and evolution requirements are 2 sub-trees branched off it.

Improving Query Objects Readability

A couple of hints on how to keep your query objects more readable:

Store nodes that will be used as roots in branch offs in meaningful variables, just like the case with charmander.
Write each selector on a separate line.
Every time you use an object selector, add an extra indentation to the next selectors.
Move construction of a new object in the middle of a query (such as an ArgumentsObject construction) to a new line.

Schema Objects Generation

After running the generation script, the SchemaInspector will run queries on the GraphQL server to retrieve the API schema. After that, the SchemaClassGenerator will traverse the schema from the root queryType recursively, creating a class for every object in the schema spec.

The SchemaClassGenerator will generate a different schema object depending on the type of object being scanned using the following mapping from GraphQL types to SchemaObject types:

OBJECT: QueryObject
INPUT_OBJECT: InputObject
ENUM: EnumObject

Additionally, an ArgumentsObject will be generated for the arguments on each field in every object. The arguments object naming convention is:

{CURRENT_OBJECT}{FIELD_NAME}ArgumentsObject

The QueryObject

The object generator will start traversing the schema from the root queryType, creating a class for each query object it encounters according to the following rules:

The RootQueryObject is generated for the type corresponding to the queryType in the schema declaration, this object is the start of all GraphQL queries.
For a query object of name {OBJECT_NAME}, a class with name {OBJECT_NAME}QueryObject will be created.
For each selection field in the selection set of the query object, a corresponding selector method will be created, according to the following rules:
- Scalar fields will have a simple selector created for them, which will add the field name to the selection set. The simple selector will return a reference to the query object being created (this).
- Object fields will have an object selector created for them, which will create a new query object internally and nest it inside the current query. The object selector will return instance of the new query object created.
For every list of arguments tied to an object field an ArgumentsObject will be created with a setter corresponding to every argument value according to the following rules:
- Scalar arguments: will have a simple setter created for them to set the scalar argument value.
- List arguments: will have a list setter created for them to set the argument value with an array
- Input object arguments: will have an input object setter created for them to set the argument value with an object of type InputObject

The InputObject

For every input object the object generator encounters while traversing the schema, it will create a corresponding class according to the following rules:

For an input object of name {OBJECT_NAME}, a class with name {OBJECT_NAME}InputObject will be created
For each field in the input object declaration, a setter will be created according to the following rules:
- Scalar fields: will have a simple setter created for them to set the scalar value.
- List fields: will have a list setter created for them to set the value with an array
- Input object arguments: will have an input object setter created for them to set the value with an object of type InputObject

The EnumObject

For every enum the object generator encounters while traversing the schema, it will create a corresponding ENUM class according to the following rules:

For an enum object of name {OBJECT_NAME}, a class with name {OBJECT_NAME}EnumObject will be created
For each EnumValue in the ENUM declaration, a const will be created to hold its value in the class

The ResultObject (New Feature)

For every object in the schema, a corresponding Result Object class will be generated with:

Properties for each field in the object
Getter methods for each property with proper type hints
fromArray() method to hydrate the object from an array
fromJson() method to hydrate the object from a JSON string
asArray() method to convert the object back to an array
Special handling for date/time fields using Carbon
Recursive handling of nested objects

License

MIT

fo3nix / php-graphql-oqm

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