com.expediagroup.graphql.server.execution.GraphQLServer.kt Maven / Gradle / Ivy

Go to download

Show more of this group Show more artifacts with this name
Show all versions of graphql-kotlin-server Show documentation

Common code for running a GraphQL server in any HTTP server framework

There is a newer version: 8.2.1

Show newest version

/*
 * Copyright 2022 Expedia, Inc
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     https://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.expediagroup.graphql.server.execution

import com.expediagroup.graphql.generator.extensions.get
import com.expediagroup.graphql.generator.extensions.plus
import com.expediagroup.graphql.server.types.GraphQLResponse
import com.expediagroup.graphql.server.types.GraphQLServerResponse
import kotlinx.coroutines.CoroutineScope
import kotlinx.coroutines.SupervisorJob
import kotlinx.coroutines.coroutineScope
import kotlin.coroutines.CoroutineContext
import kotlin.coroutines.EmptyCoroutineContext

/**
 * A basic server implementation that parses the incoming request and returns a [GraphQLResponse].
 * Subscriptions require more server-specific details and should be implemented separately.
 */
open class GraphQLServer(
    private val requestParser: GraphQLRequestParser,
    private val contextFactory: GraphQLContextFactory,
    private val requestHandler: GraphQLRequestHandler
) {
    /**
     * Default execution logic for handling a [Request] and returning a [GraphQLServerResponse].
     *
     * If null is returned, that indicates a problem parsing the request or context.
     * If the request is valid, a [GraphQLServerResponse] should always be returned.
     * In the case of errors or exceptions, return a response with GraphQLErrors populated.
     * If you need custom logic inside this method you can override this class or choose not to use it.
     */
    open suspend fun execute(
        request: Request
    ): GraphQLServerResponse? =
        coroutineScope {
            requestParser.parseRequest(request)?.let { graphQLRequest ->
                val graphQLContext = contextFactory.generateContext(request)

                val customCoroutineContext = (graphQLContext.get() ?: EmptyCoroutineContext)
                val graphQLExecutionScope = CoroutineScope(
                    coroutineContext + customCoroutineContext + SupervisorJob()
                )

                val graphQLContextWithCoroutineScope = graphQLContext + mapOf(
                    CoroutineScope::class to graphQLExecutionScope
                )

                requestHandler.executeRequest(graphQLRequest, graphQLContextWithCoroutineScope)
            }
        }
}