My query is failing in relay and I don't know why? - reactjs

Question

I have this simple query which works fine in my Graphql but I cannot pass data using relay to components and I don't know why :(
{
todolist { // todolist returns array of objects of todo
id
text
done
}
}
this is my code in an attempt to pass data in components using relay:
class TodoList extends React.Component {
render() {
return <ul>
{this.props.todos.todolist.map((todo) => {
<Todo todo={todo} />
})}
</ul>;
}
}
export default Relay.createContainer(TodoList, {
fragments: {
todos: () => Relay.QL`
fragment on Query {
todolist {
id
text
done
}
}
`,
},
});
And lastly my schema
const Todo = new GraphQLObjectType({
name: 'Todo',
description: 'This contains list of todos which belong to its\' (Persons)users',
fields: () => {
return {
id: {
type: GraphQLInt,
resolve: (todo) => {
return todo.id;
}
},
text: {
type: GraphQLString,
resolve: (todo) => {
return todo.text;
}
},
done: {
type: GraphQLBoolean,
resolve: (todo) => {
return todo.done;
}
},
}
}
});
const Query = new GraphQLObjectType({
name: 'Query',
description: 'This is the root query',
fields: () => {
return {
todolist: {
type: new GraphQLList(Todo),
resolve: (root, args) => {
return Conn.models.todo.findAll({ where: args})
}
}
}
}
});
This code looks simple and I cannot see why this won't work and I have this error Uncaught TypeError: Cannot read property 'todolist' of undefined, but I configure todolist and I can query in my graphql, you can see the structure of the query is same, I don't know why this is not working?

Answer 1

todolist should be a connection type on Query. Also, your ids should be Relay global IDs. You will not have access to your objects' raw native id fields in Relay.
import {
connectionArgs,
connectionDefinitions,
globalIdField,
} from 'graphql-relay';
// I'm renaming Todo to TodoType
const TodoType = new GraphQLObjectType({
...,
fields: {
id: uidGlobalIdField('Todo'),
...
},
});
const {
connectionType: TodoConnection,
} = connectionDefinitions({ name: 'Todo', nodeType: TodoType });
// Also renaming Query to QueryType
const QueryType = new GraphQLObjectType({
...,
fields: {
id: globalIdField('Query', $queryId), // hard-code queryId if you only have one Query concept (Facebook thinks of this top level field as being a user, so the $queryId would be the user id in their world)
todos: { // Better than todoList; generally if it's plural in Relay it's assumed to be a connection or list
type: TodoConnection,
args: connectionArgs,
},
},
});
// Now, to be able to query off of QueryType
const viewerDefaultField = {
query: { // Normally this is called `viewer`, but `query` is ok (I think)
query: QueryType,
resolve: () => ({}),
description: 'The entry point into the graph',
}
};
export { viewerDefaultField };
The above is not fully complete (you'll likely also need to setup a node interface on one or more of your types, which will require node definitions), but it should answer your basic question and get you started.
It's a huge, huge pain to learn, but once you struggle through it it starts to make sense and you'll begin to love it over RESTful calls.