Add SVG export capability

README.md

@@ -61,17 +61,17 @@ Check the integrity of the workflow, e.g.:
 
 #### Export capabilities
 
-Workflow graphs can be exported to [DOT][2], an open graph description language. Various programs can process DOT files. E.g. `dot` (GraphViz) can be used to render the graph in a graphical form. The following example renders the workflow as SVG:
+Workflow graphs can be exported to SVG or [DOT][2] (an open graph description language). Various programs can process DOT files. E.g. `dot` (GraphViz) can be used to render the graph in a graphical form. The following example uses X11 to open an interactive graph viewer based on Xlib canvas:
 
-    amflow export --format=dot | dot -v -Tsvg 2>/dev/null > ~/graph.svg
+    amflow export --format=dot --latest | dot -v -Tx11
 
-This is another example that uses X11 to open an interactive graph viewer based on Xlib canvas:
+By default, amflow hides certain graph nodes to speed up rendering. It is possible to render the full graph using the optional argument `--full`, e.g.:
 
-    amflow export --format=dot | dot -v -Tx11
+    amflow export --full --format=dot --latest | dot -v -Tx11
 
-By default, amflow hides certain graph nodes to speed up rendering. It is possible to render the full graph using the optional argument `--full`, e.g.:
+Producing a SVG document can be done similarly:
 
-    amflow export --full --format=dot | dot -v -Tx11
+    amflow export --format=svg --file=workflow.json > /tmp/workflow.svg
 
 ## Limitations
 

cmd/export.go

@@ -12,6 +12,7 @@ var (
 	exportFile   string
 	exportFormat string
 	exportFull   bool
+	exportLatest bool
 )
 
 func newCmdExport(out io.Writer) *cobra.Command {
@@ -31,23 +32,34 @@ Usage example:
 	}
 	cmd.Flags().StringVarP(&exportFile, "file", "f", "", "Path of JSON-encoded workflow document")
 	cmd.Flags().StringVarP(&exportFormat, "format", "", "dot", "Format of the export")
+	cmd.Flags().BoolVarP(&exportLatest, "latest", "", false, "Download the latest workflow available in QA")
 	cmd.Flags().BoolVarP(&exportFull, "full", "", false, "Include the full graph (slower)")
 	return cmd
 }
 
 func export(out io.Writer) error {
+	if exportLatest {
+		exportFile = latestWorkflow
+	}
 	w, err := load(exportFile)
 	if err != nil {
 		return err
 	}
 
 	checkDot()
 
-	// Print it out.
-	blob, err := w.DOT(&graph.VizOpts{Full: exportFull})
+	var blob []byte
+	switch exportFormat {
+	case "dot":
+		blob, err = w.DOT(&graph.VizOpts{Full: exportFull})
+	case "svg":
+		blob, err = w.SVG(&graph.VizOpts{Full: exportFull})
+	}
 	if err != nil {
 		return err
 	}
+
 	_, err = fmt.Fprint(out, string(blob))
+
 	return err
 }