A simple graphql middleware for oak deno framework.
! Make sure your playground endpoint indicates same as your URL http://localhost:8080/graphql
import { Application, Router, RouterContext } from "https://deno.land/x/[email protected]/mod.ts";
import { applyGraphQL, gql, GQLError } from "https://deno.land/x/oak_graphql/mod.ts";
const app = new Application();
app.use(async (ctx, next) => {
await next();
const rt = ctx.response.headers.get("X-Response-Time");
console.log(`${ctx.request.method} ${ctx.request.url} - ${rt}`);
});
app.use(async (ctx, next) => {
const start = Date.now();
await next();
const ms = Date.now() - start;
ctx.response.headers.set("X-Response-Time", `${ms}ms`);
});
const types = gql`
type User {
firstName: String
lastName: String
}
input UserInput {
firstName: String
lastName: String
}
type ResolveType {
done: Boolean
}
type Query {
getUser(id: String): User
}
type Mutation {
setUser(input: UserInput!): ResolveType!
}
`;
const resolvers = {
Query: {
getUser: (parent: any, { id }: any, context: any, info: any) => {
console.log("id", id, context);
if(context.user === "Aaron") {
throw new GQLError({ type: "auth error in context" })
}
return {
firstName: "wooseok",
lastName: "lee",
};
},
},
Mutation: {
setUser: (parent: any, { input: { firstName, lastName } }: any, context: any, info: any) => {
console.log("input:", firstName, lastName);
return {
done: true,
};
},
},
};
const GraphQLService = await applyGraphQL<Router>({
Router,
typeDefs: types,
resolvers: resolvers,
context: (ctx: RouterContext) => {
return { user: "Aaron" };
}
})
app.use(GraphQLService.routes(), GraphQLService.allowedMethods());
console.log("Server start at http://localhost:8080");
await app.listen({ port: 8080 });
- Add cache
- Enable the upload
- Enable the JSON scalar
GraphQL-tag Parsing GraphQL queries
gql
A JavaScript template literal tag that parses GraphQL query strings into the standard GraphQL AST.
An error handler
Example
throw new GQLError("string");
or
throw new GQLError({type: "General error", detail: "somthing critical!"});
A Generator which based Attain Router class creates some middlewares for supporting the GraphQL.
Options
- Router: oak Router module
Due to the version incompatible issue mentioned by (avalero)[https://github.com/avalero], I've decoupled the Router. Thanks :) - path?: string
A target path that handles the GraphQL post request (*optional: default as/graphql
) - typeDefs: any
generated type tags by thegql
- resolvers: any
An object that handles the queries and mutations
const resolvers = {
Query: {
getUser: (parent: any, {id}: any, context: any, info: any) => {
// ...query handling function here
},
},
Mutation: {
addUser: (parent: any, {firstName, lastName}: any, context: any, info: any) => {
// ...add user codes here
},
}
}
The resolvers will be received these four parameters
- parent: The return value of the resolver for this field's parent
- args: An object that contains all GraphQL arguments provided for this field.
- context: An object shared across all resolvers that are executing for a particular operation.
- info: Contains information about the operation's execution state, including the field name, the path to the field from the root, and more.
- context?: (ctx) => any
Send any objects to each resolver (*optional) - usePlayground?: boolean;
enable the playground at get method (*optional: default astrue
)