我是GraphQL的新手,想要使用graphql-php进行编程,以便构建一个简单的API来开始 . 我正在阅读文档并试用这些例子,但我在开始时就陷入了困境 .
我希望我的架构存储在 schema.graphql
文件中,而不是手动构建它,所以我按照文档说明了如何做到这一点,它确实有效:
<?php
// graph-ql is installed via composer
require('../vendor/autoload.php');
use GraphQL\Language\Parser;
use GraphQL\Utils\BuildSchema;
use GraphQL\Utils\AST;
use GraphQL\GraphQL;
try {
$cacheFilename = 'cached_schema.php';
// caching, as recommended in the docs, is disabled for testing
// if (!file_exists($cacheFilename)) {
$document = Parser::parse(file_get_contents('./schema.graphql'));
file_put_contents($cacheFilename, "<?php\nreturn " . var_export(AST::toArray($document), true) . ';');
/*} else {
$document = AST::fromArray(require $cacheFilename); // fromArray() is a lazy operation as well
}*/
$typeConfigDecorator = function($typeConfig, $typeDefinitionNode) {
// In the docs, this function is just empty, but I needed to return the $typeConfig, otherwise I got an error
return $typeConfig;
};
$schema = BuildSchema::build($document, $typeConfigDecorator);
$context = (object)array();
// this has been taken from one of the examples provided in the repo
$rawInput = file_get_contents('php://input');
$input = json_decode($rawInput, true);
$query = $input['query'];
$variableValues = isset($input['variables']) ? $input['variables'] : null;
$rootValue = ['prefix' => 'You said: '];
$result = GraphQL::executeQuery($schema, $query, $rootValue, $context, $variableValues);
$output = $result->toArray();
} catch (\Exception $e) {
$output = [
'error' => [
'message' => $e->getMessage()
]
];
}
header('Content-Type: application/json; charset=UTF-8');
echo json_encode($output);
这就是我的 schema.graphql
文件的样子:
schema {
query: Query
}
type Query {
products: [Product!]!
}
type Product {
id: ID!,
type: ProductType
}
enum ProductType {
HDRI,
SEMISPHERICAL_HDRI,
SOUND
}
我可以用例如查询它
query {
__schema {types{name}}
}
这将按预期返回元数据 . 但是,当然现在我想查询实际的产品数据并从数据库中获取,为此我需要定义一个解析器函数 .
http://webonyx.github.io/graphql-php/type-system/type-language/状态的文档:"By default, such schema is created without any resolvers. We have to rely on default field resolver and root value in order to execute a query against this schema." - 但没有这样做的例子 .
如何为每个类型/字段添加解析器功能?
2 回答
这就是我最终做的......
然后在配置中
对我来说感觉相当黑客,我应该将解析器外包到单独的文件中,但是它有效...仍然感到困惑的是,这个任务没有简单的例子,可能比我的解决方案更好...
此方法无需实例化服务器即可运行 . 在我的情况下,我已经有一个服务器,可以读取HTTP数据,我只需要读取GraphQL模式并运行查询 . 首先,我从文件中读取架构:
然后我执行传递自定义字段解析器的查询:
字段解析器看起来像这样: