Example<\/strong><\/h3>\nAs this is a blog for the beginners or fresher let\u2019s do a simple example.<\/p>\n
Let’s create a type system that will be to process following simple query:<\/p>\n
query {\r\n echo(message: "Hi Knowband, this is my first GraphQL program")\r\n}\r\n<\/pre>\nNote:<\/strong> We need an object type with field echo to do so.<\/p>\n<?php\r\nuse GraphQL\\Type\\Definition\\ObjectType;\r\nuse GraphQL\\Type\\Definition\\Type;\r\n$queryType = new ObjectType([\r\n 'name' => 'Query',\r\n 'fields' => [\r\n 'echo' => [\r\n 'type' => Type::string(),\r\n 'args' => [\r\n 'message' => Type::nonNull(Type::string()),\r\n ],\r\n 'resolve' => function ($root, $args) {\r\n return $root['prefix'] . $args['message'];\r\n }\r\n ],\r\n ],\r\n]);<\/pre>\nThe\u00a0resolve\u00a0option\u00a0is\u00a0very\u00a0important\u00a0option\u00a0of\u00a0field\u00a0definition.\u00a0It\u00a0is\u00a0one\u00a0which\u00a0is\u00a0responsible\u00a0to\u00a0for\u00a0returning\u00a0the\u00a0value\u00a0of\u00a0our\u00a0field.\u00a0Values\u00a0of\u00a0the\u00a0scalar\u00a0fields\u00a0will\u00a0be\u00a0directly\u00a0get\u00a0included\u00a0in\u00a0response\u00a0while\u00a0the\u00a0values\u00a0of\u00a0the\u00a0composite\u00a0fields\u00a0will\u00a0be\u00a0passed\u00a0down\u00a0to\u00a0the\u00a0nested\u00a0field\u00a0resolvers.\u00a0Composite\u00a0fields\u00a0are\u00a0interfaces,\u00a0unions,\u00a0objects\u00a0etc.<\/p>\n
Now\u00a0after\u00a0our\u00a0type\u00a0become\u00a0ready,\u00a0let\u2019s\u00a0write\u00a0the\u00a0GraphQL\u00a0endpoint\u00a0file\u00a0for\u00a0it\u00a0graphql_program_1.php.<\/p>\n
<?php\r\nuse GraphQL\\GraphQL;\r\nuse GraphQL\\Type\\Schema;\r\ntry {\r\n $schema_obj = new Schema([\r\n 'query' => $queryType\r\n ]);\r\n $Input = file_get_contents('php:\/\/input');\r\n $input_data = json_decode($Input, true);\r\n $query_data = $input_data['query'];\r\n $variable_values = isset($input_data['variables']) ? $input_data['variables'] : null;\r\n $value = ['prefix' => 'Output: '];\r\n $resultant = GraphQL::executeQuery($schema_obj, $query_data, $value, null, $variable_values);\r\n $output_value = $resultant->toArray();\r\n} catch (\\Exception $e) {\r\n $output_value = [\r\n 'errors' => [\r\n [\r\n 'message' => $e->getMessage()\r\n ]\r\n ]\r\n ];\r\n}\r\nheader('Content-Type: application\/json');\r\necho json_encode($output_value);\r\n?><\/pre>\nHow can we run the code?<\/strong><\/h3>\nWe can run the code by:<\/p>\n
php -S localhost:8080 graphql_program_1.php\r\ncurl https:\/\/localhost:8080 -d '{"query": "query { echo(message: \\" Hi Knowband, this is my first GraphQL program \\") }" }'<\/pre>\nFor any queries, please feel free to reach us at support@knowband.com. Knowband is providing the best in class modules for Prestashop, Opencart, Magento and Magento 2.<\/p>\n
Take a look at one of our most popular for Prestashop called One page supercheckout:
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![\"How](\"https:\/\/www.knowband.com\/blog\/wp-content\/uploads\/2018\/10\/Main-Banner-graphql-php-2.png\")
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