A GraphQL client written in PHP which provides very simple, yet powerful, query generator classes that make the process of interacting with a GraphQL server a very simple one.
There are 3 primary ways to use this package to generate your GraphQL queries:
- Query Class: Simple class that maps to GraphQL queries. It's designed to manipulate queries with ease and speed.
- QueryBuilder Class: Builder class that can be used to generate
Queryobjects dynamically. It's design to be used in cases where a query is being build in a dynamic fashion. - PHP GraphQL-OQM: An extension to this package. It Eliminates the need to write any GraphQL queries or refer to the API documentation or syntax. It generates query objects from the API schema, declaration exposed through GraphQL's introspection, which can then be simply interacted with.
Run the following command to install the package using composer:
$ composer require gmostafa/php-graphql-client
To avoid the hassle of having to write any queries and just interact with PHP objects generated from your API schema visit PHP GraphQL OQM repository
$gql = (new Query('companies'))
->setSelectionSet(
[
'name',
'serialNumber'
]
);
This simple query will retrieve all companies displaying their names and serial numbers.
$gql = (new Query('companies'))
->setSelectionSet(
[
'name',
'serialNumber',
(new Query('branches'))
->setSelectionSet(
[
'address',
(new Query('contracts'))
->setSelectionSet(['date'])
]
)
]
);
This query is a more complex one, retrieving not just scalar fields, but object fields as well. This query returns all companies, displaying their names, serial numbers, and for each company, all its branches, displaying the branch address, and for each address, it retrieves all contracts bound to this address, displaying their dates.
$gql = (new Query('companies'))
->setArguments(['name' => 'Tech Co.', 'first' => 3])
->setSelectionSet(
[
'name',
'serialNumber'
]
);
This query does not retrieve all companies by adding arguments. This query will retrieve the first 3 companies with the name "Tech Co.", displaying their names and serial numbers.
$gql = (new Query('companies'))
->setArguments(['serialNumbers' => [159, 260, 371]])
->setSelectionSet(
[
'name',
'serialNumber'
]
);
This query is a special case of the arguments query. In this example, the query will retrieve only the companies with serial number in one of 159, 260, and 371, displaying the name and serial number.
$gql = (new Query('companies'))
->setArguments(['filter' => new RawObject('{name_starts_with: "Face"}')])
->setSelectionSet(
[
'name',
'serialNumber'
]
);
This query is another special case of the arguments query. In this example, we're setting a custom input object "filter" with some values to limit the companies being returned. We're setting the filter "name_starts_with" with value "Face". This query will retrieve only the companies whose names start with the phrase "Face".
The RawObject class being constructed is used for injecting the string into the query as it is. Whatever string is input into the RawObject constructor will be put in the query as it is without any custom formatting normally done by the query class.
$gql = (new Query('companies'))
->setVariables(
[
new Variable('name', 'String', true),
new Variable('limit', 'Int', false, 5)
]
)
->setArguments(['name' => '$name', 'first' => '$limit'])
->setSelectionSet(
[
'name',
'serialNumber'
]
);
This query shows how variables can be used in this package to allow for dynamic requests enabled by GraphQL standards.
The Variable class is an immutable class that represents a variable in GraphQL standards. Its constructor receives 4 arguments:
- name: Represents the variable name
- type: Represents the variable type according to the GraphQL server schema
- isRequired (Optional): Represents if the variable is required or not, it's false by default
- defaultValue (Optional): Represents the default value to be assigned to the variable. The default value will only be considered if the isRequired argument is set to false.
The QueryBuilder class can be used to construct Query objects dynamically, which can be useful in some cases. It works very similarly to the Query class, but the Query building is divided into steps.
That's how the "Query With Input Object Argument" example can be created using the QueryBuilder:
$builder = (new QueryBuilder('companies'))
->setVariable('namePrefix', 'String', true)
->setArgument('filter', new RawObject('{name_starts_with: $namePrefix}'))
->selectField('name')
->selectField('serialNumber');
$gql = $builder->getQuery();
A Client object can easily be instantiated by providing the GraphQL endpoint URL. The Client constructor also receives an optional "authorizationHeaders" array, which can be used to add authorization headers to all requests being sent to the GraphQL server.
Example:
$client = new Client(
'http://api.graphql.com',
['Authorization' => 'Basic xyz']
);
Running query with the GraphQL client and getting the results in object structure:
$results = $client->runQuery($gql);
$results->getData()->Company[0]->branches;
Or getting results in array structure:
$results = $client->runQuery($gql, true);
$results->getData()['Company'][1]['branches']['address']
Running queries containing variables requires passing an associative array which
maps variable names (keys) to variable values (values) to the runQuery method.
Here's an example:
$gql = (new Query('companies'))
->setVariables(
[
new Variable('name', 'String', true),
new Variable('limit', 'Int', false, 5)
]
)
->setArguments(['name' => '$name', 'first' => '$limit'])
->setSelectionSet(
[
'name',
'serialNumber'
]
);
$variablesArray = ['name' => 'Tech Co.', 'first' => 5];
$results = $client->runQuery($gql, true, $variablesArray);
Mutations follow the same rules of queries in GraphQL, they select fields on returned objects, receive arguments, and can have sub-fields.
Here's a sample example on how to construct and run mutations:
$mutation = (new Mutation('createCompany'))
->setArguments(['companyObject' => new RawObject('{name: "Trial Company", employees: 200}')])
->setSelectionSet(
[
'_id',
'name',
'serialNumber',
]
);
$results = $client->runQuery($mutation);
Mutations can be run by the client the same way queries are run.
Mutations can utilize the variables in the same way Queries can. Here's an example on how to use the variables to pass input objects to the GraphQL server dynamically:
$mutation = (new Mutation('createCompany'))
->setVariables([new Variable('company', 'CompanyInputObject', true)])
->setArguments(['companyObject' => '$company']);
$variables = ['company' => ['name' => 'Tech Company', 'type' => 'Testing', 'size' => 'Medium']];
$client->runQuery(
$mutation, true, $variables
);
These are the resulting mutation and the variables passed with it:
mutation($company: CompanyInputObject!) {
createCompany(companyObject: $company)
}
{"company":{"name":"Tech Company","type":"Testing","size":"Medium"}}
GraphQL Pokemon is a very cool public GraphQL API available to retrieve Pokemon data. The API is available publicly on the web, we'll use it to demo the capabilities of this client.
Github Repo link: https://github.com/lucasbento/graphql-pokemon
API link: https://graphql-pokemon.now.sh/
This query retrieves any pokemon's evolutions and their attacks:
query($name: String!) {
pokemon(name: $name) {
id
number
name
evolutions {
id
number
name
weight {
minimum
maximum
}
attacks {
fast {
name
type
damage
}
}
}
}
}
That's how this query can be written using the query class and run using the client:
$client = new Client(
'https://graphql-pokemon.now.sh/'
);
$gql = (new Query('pokemon'))
->setVariables([new Variable('name', 'String', true)])
->setArguments(['name' => '$name'])
->setSelectionSet(
[
'id',
'number',
'name',
(new Query('evolutions'))
->setSelectionSet(
[
'id',
'number',
'name',
(new Query('attacks'))
->setSelectionSet(
[
(new Query('fast'))
->setSelectionSet(
[
'name',
'type',
'damage',
]
)
]
)
]
)
]
);
try {
$name = readline('Enter pokemon name: ');
$results = $client->runQuery($gql, true, ['name' => $name]);
}
catch (QueryError $exception) {
print_r($exception->getErrorDetails());
exit;
}
print_r($results->getData()['pokemon']);
Or alternatively, That's how this query can be generated using the QueryBuilder class:
$client = new Client(
'https://graphql-pokemon.now.sh/'
);
$builder = (new QueryBuilder('pokemon'))
->setVariable('name', 'String', true)
->setArgument('name', '$name')
->selectField('id')
->selectField('number')
->selectField('name')
->selectField(
(new QueryBuilder('evolutions'))
->selectField('id')
->selectField('name')
->selectField('number')
->selectField(
(new QueryBuilder('attacks'))
->selectField(
(new QueryBuilder('fast'))
->selectField('name')
->selectField('type')
->selectField('damage')
)
)
);
try {
$name = readline('Enter pokemon name: ');
$results = $client->runQuery($builder, true, ['name' => $name]);
}
catch (QueryError $exception) {
print_r($exception->getErrorDetails());
exit;
}
print_r($results->getData()['pokemon']);
Although not the primary goal of this package, but it supports running raw
string queries, just like any other client using the runRawQuery method in the
Client class. Here's an example on how to use it:
$gql = <<<QUERY
query {
pokemon(name: "Pikachu") {
id
number
name
attacks {
special {
name
type
damage
}
}
}
}
QUERY;
$results = $client->runQuery($gql);