Unmarshalling geo point

Users
1

Hey

I was trying to Unmarshal a geo property into a struct in golang, but I haven’t found any examples on how to do that. How do I go about doing that?

2

Hey @felipellrocha

This is how you do it in v0.8.3.

conn, err := grpc.Dial("127.0.0.1:9080", grpc.WithInsecure())
x.Checkf(err, "While trying to dial gRPC")
defer conn.Close()

clientDir, err := ioutil.TempDir("", "client_")
x.Check(err)
defer os.RemoveAll(clientDir)

dgraphClient := client.NewDgraphClient(
    []*grpc.ClientConn{conn}, client.DefaultOptions, clientDir)

req := client.Req{}

alice, err := dgraphClient.NodeBlank("alice")
if err != nil {
    log.Fatal(err)
}
e := alice.Edge("name")
e.SetValueString("Alice")
err = req.Set(e)
x.Check(err)

e = alice.Edge("loc")
err = e.SetValueGeoJson(`{"Type":"Point", "Coordinates":[1.1,2.0]}`)
x.Check(err)
err = req.Set(e)
x.Check(err)

e = alice.Edge("city")
err = e.SetValueGeoJson(`{
        "Type":"Polygon",
        "Coordinates":[[[0.0,0.0], [2.0,0.0], [2.0, 2.0], [0.0, 2.0], [0.0, 0.0]]]
    }`)
x.Check(err)
err = req.Set(e)
x.Check(err)

req.SetQuery(`mutation {
    schema {
        name: string @index(exact) .
    }
}
{
    q(func: eq(name, "Alice")) {
        name
        loc
        city
    }
}`)

resp, err := dgraphClient.Run(context.Background(), &req)
if err != nil {
    log.Fatalf("Error in getting response from server, %s", err)
}

type Alice struct {
    Name string `json:"name"`
    Loc  []byte `json:"loc"`
    City []byte `json:"city"`
}

type Res struct {
    Root Alice `json:"q"`
}

var r Res
err = client.Unmarshal(resp.N, &r)
x.Check(err)
fmt.Printf("Alice: %+v\n\n", r.Root)
loc, err := wkb.Unmarshal(r.Root.Loc)
x.Check(err)
city, err := wkb.Unmarshal(r.Root.City)
x.Check(err)

fmt.Printf("Loc: %+v\n\n", loc)
fmt.Printf("City: %+v\n\n", city)
err = dgraphClient.Close()
x.Check(err)

The geo fields are unmarshalled into a byte slice, which is later unmarshalled using wkb.Unmarshal.

This is how you would do it from the next version (which should be out in a week) https://godoc.org/github.com/dgraph-io/dgraph/client#example-package--SetObject. See the Location field.

3

We should also add this in the Clients page in our documentation.

4

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