compiledSchema is regular executable schema compatible with graphql-js library.
To use it with express, you'd have to simply:
import*asexpressfrom'express';import*asgraphqlHTTPfrom'express-graphql';constapp=express();app.use('/graphql',graphqlHTTP({schema: compiledSchema,graphiql: true,}),);app.listen(3000,()=>console.log('Graphql API ready on http://localhost:3000/graphql'));
Adding nested types
For now, our query field returned scalar (string). Let's return something more complex. Schema will look like:
Until now, typegql was able to guess type of every field from typescript type definitions.
There are, however, some cases where we'd have to define them explicitly.
We want to strictly tell if field is nullable or not
We want to be explicit about if some number type is Float or Int (GraphQLFloat or GraphQLInt) etc
Function we use returns type of Promise<SomeType> while field itself is typed as SomeType
List (Array) type is used. (For now, typescript Reflect api is not able to guess type of single array item. This might change in the future)
Let's modify our Product so it has additional categories field that will return array of strings. For sake of readibility, I'll ommit all fields we've defined previously.
@ObjectType()classProduct{
@Field({type: [String]})// note we can use any native type like GraphQLString!categories(): string[]{return['Tables','Furniture'];}}
We've added { type: [String] } as @Field options. Type can be anything that is resolvable to GraphQL type
Native JS scalars: String, Number, Boolean.
Any type that is already compiled to graphql eg. GraphQLFloat or any type from external graphql library etc
Every class decorated with @ObjectType
One element array of any of above for list types eg. [String] or [GraphQLFloat]
Writing Asynchronously
Every field function we write can be async and return Promise. Let's say, instead of hard-coding our categories, we want to fetch it from some external API:
@ObjectType()classProduct{
@Field({type: [String]})// note we can use any native type like GraphQLString!asynccategories(): Promise<string[]>{constcategories=awaitapi.fetchCategories();returncategories.map(cat=>cat.name);}}
Before 1.0.0
Before version 1.0.0 consider APIs of typegql to be subject to change. We encourage you to try this library out and provide us feedback so we can polish it to be as usable and efficent as possible.
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