2-basic-group-data.md

2. Fetching basic data about Meetup.com Groups

As you may have noticed, the API is almost useless at this point. In this chapter you are going to move from a useless API to a meaningful one. You will end returning basic Meetup.com Groups data instead of those ugly error messages.

1. Take a look to the models provided by the github.com/smoya/graphql-go-workshop/pkg/meetup package

Navigate to https://github.com/smoya/graphql-go-workshop/blob/master/pkg/meetup/model.go. You will find Structs describing the basic models for our API. Let's be focused on the Group one.

type Group struct {
	ID                int     `json:"id"`
	Name              string  `json:"name"`
	Created           int64   `json:"created"`
	JoinMode          string  `json:"join_mode"`
	Lat               float64 `json:"lat"`
	Lon               float64 `json:"lon"`
	Urlname           string  `json:"urlname"`
	Who               string  `json:"who"`
	LocalizedLocation string  `json:"localized_location"`
	State             string  `json:"state"`
	Country           string  `json:"country"`
	Region            string  `json:"region"`
	Timezone          string  `json:"timezone"`
}

2. Tell gqlgen to reuse the model

In order to avoid maintaining two versions of our models, you can tell gqlgen to skip code generation for some of your models and use your own instead.

1. Edit the gqlgen.yml file adding the following content:

models:
  Group:
    model: github.com/smoya/graphql-go-workshop/pkg/meetup.Group

2. Remove the resolver.go file. This will let the gqlgen to regenerate it again.
3. Run gqlgen in order to regenerate the code.

3. Fetch Group data from Meetup.com API

At this point we are ready to start using the methods found in [https://github.com/smoya/graphql-go-workshop/blob/master/pkg/meetup/meetup.go][https://github.com/smoya/graphql-go-workshop/blob/master/pkg/meetup/meetup.go] and start fetching data directly from Meetup.com API.

1. Grab your API Key from Meetup.com.
2. Generate a Client for calling the Meetup.com API. You can quickly do this by calling the NewClient method on the meetup library:

// We could configure our http client with any desired option.
httpc := http.Client{
    Timeout: s.Timeout,
}
c := meetup.NewClient(&httpc, MEETUP_APIKEY_HERE)

3. Pass this client to the Resolver struct.

// resolver.go
type Resolver struct{
	c *meetup.Client
}

// server.go
Resolver{C: c}

4. Let the QueryResolver.Group resolver method use that client for fetching a Meetup.com Group.

func (r *queryResolver) Group(ctx context.Context, name string) (*meetup.Group, error) {
	return r.C.Group(name)
}

4. Play

Run go run server/server.go. Open your browser and navigate to http://localhost:8080.

Execute any available query. Example:

{
  group(name: "Golang-Barcelona") {
    name
  }
}

Congratulations! You have just created very first GraphQL Resolver.