Function GetGQLSchema

edgraph/server.go:114–160

GetGQLSchema queries for the GraphQL schema node, and returns the uid and the GraphQL schema. If multiple schema nodes were found, it returns an error.

(namespace uint64)

// GetGQLSchema queries for the GraphQL schema node, and returns the uid and the GraphQL schema.
// If multiple schema nodes were found, it returns an error.
func GetGQLSchema(namespace uint64) (uid, graphQLSchema string, err error) {
	ctx := context.WithValue(context.Background(), Authorize, false)
	ctx = x.AttachNamespace(ctx, namespace)
	resp, err := (&Server{}).QueryNoGrpc(ctx,
		&api.Request{
			Query: `
			query {
				ExistingGQLSchema(func: has(dgraph.graphql.schema)) {
					uid
					dgraph.graphql.schema
				  }
				}`})
	if err != nil {
		return "", "", err
	}

	var result existingGQLSchemaQryResp
	if err := json.Unmarshal(resp.GetJson(), &result); err != nil {
		return "", "", errors.Wrap(err, "Couldn't unmarshal response from Dgraph query")
	}
	res := result.ExistingGQLSchema
	if len(res) == 0 {
		// no schema has been stored yet in Dgraph
		return "", "", nil
	} else if len(res) == 1 {
		// we found an existing GraphQL schema
		gqlSchemaNode := res[0]
		return gqlSchemaNode.Uid, gqlSchemaNode.Schema, nil
	}

	// found multiple GraphQL schema nodes, this should never happen
	// returning the schema node which is added last
	for i := range res {
		iUid, err := dql.ParseUid(res[i].Uid)
		if err != nil {
			return "", "", err
		}
		res[i].UidInt = iUid
	}

	sort.Slice(res, func(i, j int) bool {
		return res[i].UidInt < res[j].UidInt
	})
	glog.Errorf("namespace: %d. Multiple schema nodes found, using the last one", namespace)
	resLast := res[len(res)-1]
	return resLast.Uid, resLast.Schema, nil
}

// UpdateGQLSchema updates the GraphQL and Dgraph schemas using the given inputs.
// It first validates and parses the dgraphSchema given in input. If that fails,