Merge pull request #16 from joelrebel/edge-labels

Support adding labels on edges.

dot/basic.go

@@ -39,7 +39,7 @@ func NewBasicGraph(
 
 	edges := make([]Renderable, 0, len(graph.Edges))
 	for _, e := range graph.Edges {
-		edges = append(edges, BasicEdge{from: e.From(), to: e.To()})
+		edges = append(edges, BasicEdge{from: e.From(), to: e.To(), label: e.Label()})
 	}
 
 	return BasicGraph{
@@ -67,10 +67,18 @@ func (r BasicGraph) Render() string {
 }
 
 type BasicEdge struct {
-	from string
-	to   string
+	from  string
+	to    string
+	label string
 }
 
 func (r BasicEdge) Render() string {
-	return fmt.Sprintf(`"%s" -> "%s"`, r.from, r.to)
+	e := fmt.Sprintf(`"%s" -> "%s"`, r.from, r.to)
+
+	// include edge label when declared
+	if r.label != "" {
+		e += fmt.Sprintf(" [label=%s]", r.label)
+	}
+
+	return e
 }

graph/json.go

@@ -29,7 +29,7 @@ func (n NodeData) ID() string {
 	return v
 }
 
-// EdgeData can have any fields, only `from` and `to` is reserved.
+// EdgeData can have any fields, only `from`, `to`, `label` is reserved.
 // This is JSON representation of edge.
 type EdgeData map[string]interface{}
 
@@ -50,6 +50,11 @@ func (e EdgeData) To() string {
 	return v
 }
 
+func (e EdgeData) Label() string {
+	v, _ := e["label"].(string)
+	return v
+}
+
 // union type, can be either
 type orNodeDataEdgeData map[string]interface{}
 

graph/json_test.go

@@ -70,7 +70,7 @@ func TestEdgeData(t *testing.T) {
 		},
 		{
 			name:     "valid with string id",
-			EdgeData: EdgeData(map[string]interface{}{"from": "asdf", "to": "12a3"}),
+			EdgeData: EdgeData(map[string]interface{}{"from": "asdf", "to": "12a3", "label": "foo"}),
 			valid:    true,
 		},
 		{
@@ -126,7 +126,7 @@ func TestOr(t *testing.T) {
 		},
 		{
 			name: "EdgeData",
-			or:   orNodeDataEdgeData(map[string]interface{}{"from": "123", "to": "456"}),
+			or:   orNodeDataEdgeData(map[string]interface{}{"from": "123", "to": "456", "label": "foo"}),
 			e:    &e,
 		},
 		{
@@ -180,6 +180,7 @@ func TestParser(t *testing.T) {
 		input := `
 		{"id": "123"}
 		{"from": "123", "to": "321"}
+		{"from": "456", "to": "789", "label": "foo"}
 		`
 		g, err := NewGraphFromJSONL(strings.NewReader(input))
 		if err != nil {
@@ -200,5 +201,20 @@ func TestParser(t *testing.T) {
 		if edge["from"] != "123" || edge["to"] != "321" {
 			t.Errorf("bad EdgeData %#v", edge)
 		}
+
+		from = g.IDStorage.Get("456")
+		if v, ok := g.Nodes[from]; !ok || v["id"] != "456" {
+			t.Errorf("bad NodeData %#v", g.Nodes)
+		}
+
+		to = g.IDStorage.Get("789")
+		if v, ok := g.Nodes[to]; !ok || v["id"] != "789" {
+			t.Errorf("bad NodeData %#v", g.Nodes)
+		}
+
+		edge = g.Edges[[2]uint64{from, to}]
+		if edge["from"] != "456" || edge["to"] != "789" || edge["label"] != "foo" {
+			t.Errorf("bad EdgeData %#v", edge)
+		}
 	})
 }