genql: quick hack at variables

example/caller.go

@@ -34,6 +34,12 @@ func Main() {
 		return
 	}
 
+	if len(os.Args) != 2 {
+		err = fmt.Errorf("usage: %v <username>", os.Args[0])
+		return
+	}
+	username := os.Args[1]
+
 	httpClient := http.Client{
 		Transport: &authedTransport{
 			key:     key,
@@ -41,10 +47,16 @@ func Main() {
 		},
 	}
 	graphqlClient := graphql.NewClient("https://api.github.com/graphql", &httpClient)
-	resp, err := getViewer(context.Background(), graphqlClient)
+
+	viewerResp, err := getViewer(context.Background(), graphqlClient)
 	if err != nil {
 		return
 	}
+	fmt.Println("you are", *viewerResp.Viewer.Name)
 
-	fmt.Println("you are:", *resp.Viewer.Name)
+	userResp, err := getUser(context.Background(), graphqlClient, username)
+	if err != nil {
+		return
+	}
+	fmt.Println(username, "is", *userResp.User.Name)
 }

example/generated.go

@@ -14,6 +14,7 @@ type getViewerResponse = struct {
 
 // TODO
 func getViewer(ctx context.Context, client *graphql.Client) (*getViewerResponse, error) {
+
 	var retval getViewerResponse
 	err := client.MakeRequest(ctx, `
 query getViewer {
@@ -21,6 +22,31 @@ query getViewer {
 		Name: name
 	}
 }
-`, &retval)
+`, &retval, nil)
+	return &retval, err
+}
+
+type getUserResponse = struct {
+	User *struct {
+		Name *string
+	}
+}
+
+// TODO
+func getUser(ctx context.Context, client *graphql.Client, login string) (*getUserResponse, error) {
+
+	variables := map[string]interface{}{
+
+		"login": login,
+	}
+
+	var retval getUserResponse
+	err := client.MakeRequest(ctx, `
+query getUser ($login: String!) {
+	User: user(login: $login) {
+		Name: name
+	}
+}
+`, &retval, variables)
 	return &retval, err
 }

example/queries.graphql

@@ -4,3 +4,10 @@ query getViewer {
     Name: name
   }
 }
+
+# getUser gets the given user's name.
+query getUser($login: String!) {
+  User: user(login: $login) {
+    Name: name
+  }
+}

generate/generate.go

@@ -26,22 +26,31 @@ type TemplateParams struct {
 	// The name of the package into which to generate the operation-helpers.
 	PackageName string
 	// The list of operations for which to generate code.
-	Operations []OperationParams
+	Operations []Operation
 }
 
-type OperationParams struct {
+type Operation struct {
+	// The type of the operation (query, mutation, or subscription).
+	Type ast.Operation
+	// The name of the operation, from GraphQL.
+	Name string
+	// The documentation for the operation, from GraphQL.
+	Doc string
+	// The body of the operation to send.
+	Body string
+	// The arguments to the operation.
+	Args []Argument
+
 	// The type-name for the operation's response type.
 	ResponseName string
 	// The body of the operation's response type (e.g. struct { ... }).
 	ResponseType string
-	// The type of the operation (query, mutation, or subscription).
-	OperationType ast.Operation
-	// The name of the operation, from GraphQL.
-	OperationName string
-	// The documentation for the operation, from GraphQL.
-	OperationDoc string
-	// The body of the operation to send.
-	Operation string
+}
+
+type Argument struct {
+	GoName      string
+	GoType      string
+	GraphQLName string
 }
 
 func Generate(specFilename, schemaFilename, generatedFilename string) error {
@@ -98,7 +107,7 @@ func Generate(specFilename, schemaFilename, generatedFilename string) error {
 	packageName := "example"
 
 	// TODO: this should probably get factored out
-	operations := make([]OperationParams, len(document.Operations))
+	operations := make([]Operation, len(document.Operations))
 	for i, operation := range document.Operations {
 		// TODO: we may have to actually get the precise query text, in case we
 		// want to be hashing it or something like that.  Although maybe
@@ -110,20 +119,30 @@ func Generate(specFilename, schemaFilename, generatedFilename string) error {
 			Operations: ast.OperationList{operation},
 			// TODO: handle fragments
 		})
-		operations[i] = OperationParams{
-			OperationType: operation.Operation,
-			OperationName: operation.Name,
+
+		args := make([]Argument, len(operation.VariableDefinitions))
+		for i, arg := range operation.VariableDefinitions {
+			args[i] = Argument{
+				GraphQLName: arg.Variable,
+				GoName:      arg.Variable, // TODO: normalize this to go-style
+				GoType:      typeForInputType(arg.Type, schema),
+				// TODO: figure out what to do about defaults
+			}
+		}
+		operations[i] = Operation{
+			Type: operation.Operation,
+			Name: operation.Name,
 			// TODO: this is actually awkward, because GraphQL doesn't allow
 			// for docstrings on queries (only schemas).  So we have to extract
 			// the comment, or omit doc-comments for now.
-			OperationDoc: "TODO",
+			Doc: "TODO",
+			// The newline just makes it format a little nicer
+			Body: "\n" + builder.String(),
+			Args: args,
 
 			// TODO: configure ResponseName format
 			ResponseName: operation.Name + "Response",
-			ResponseType: typeFor(operation, schema),
-
-			// The newline just makes it format a little nicer
-			Operation: "\n" + builder.String(),
+			ResponseType: typeForOperation(operation, schema),
 		}
 	}
 

generate/operation.go.tmpl

@@ -9,10 +9,17 @@ import (
 {{range .Operations}}
 type {{.ResponseName}} = {{.ResponseType}}
 
-// {{.OperationDoc}}
-func {{.OperationName}}(ctx context.Context, client *graphql.Client) (*{{.ResponseName}}, error) {
+// {{.Doc}}
+func {{.Name}}(ctx context.Context, client *graphql.Client{{range .Args}}, {{.GoName}} {{.GoType}}{{end}}) (*{{.ResponseName}}, error) {
+    {{if .Args}}
+    variables := map[string]interface{}{
+        {{range .Args}}
+        "{{.GraphQLName}}": {{.GoName}},
+        {{end}}
+    }
+    {{end}}
 	var retval {{.ResponseName}}
-    err := client.MakeRequest(ctx, `{{.Operation}}`, &retval)
+    err := client.MakeRequest(ctx, `{{.Body}}`, &retval, {{if .Args}}variables{{else}}nil{{end}})
     return &retval, err
 }
 {{end}}

generate/types.go

@@ -7,7 +7,7 @@ import (
 	"github.com/vektah/gqlparser/ast"
 )
 
-func typeFor(operation *ast.OperationDefinition, schema *ast.Schema) string {
+func typeForOperation(operation *ast.OperationDefinition, schema *ast.Schema) string {
 	var builder strings.Builder
 
 	writeSelectionSetStruct(&builder, operation.SelectionSet, schema)
@@ -15,6 +15,16 @@ func typeFor(operation *ast.OperationDefinition, schema *ast.Schema) string {
 	return builder.String()
 }
 
+func typeForInputType(typ *ast.Type, schema *ast.Schema) string {
+	var builder strings.Builder
+
+	// TODO: handle non-scalar types (by passing ...something... as the
+	// SelectionSet?)
+	writeType(&builder, typ, nil, schema)
+
+	return builder.String()
+}
+
 func writeSelectionSetStruct(builder *strings.Builder, selectionSet ast.SelectionSet, schema *ast.Schema) {
 	builder.WriteString("struct {\n")
 	for _, selection := range selectionSet {

graphql/client.go

@@ -25,14 +25,14 @@ func NewClient(endpoint string, httpClient *http.Client) *Client {
 }
 
 type payload struct {
-	Query     string            `json:"query"`
-	Variables map[string]string `json:"variables"`
+	Query     string                 `json:"query"`
+	Variables map[string]interface{} `json:"variables"`
 }
 
-func (client *Client) MakeRequest(ctx context.Context, query string, retval interface{}) error {
+func (client *Client) MakeRequest(ctx context.Context, query string, retval interface{}, variables map[string]interface{}) error {
 	body, err := json.Marshal(payload{
 		Query:     query,
-		Variables: nil, // TODO
+		Variables: variables,
 	})
 	if err != nil {
 		return err