Updated readme

README.md

@@ -14,8 +14,12 @@ go get github.com/mikefarah/yaml
 - Deep read a yaml file with a given path
 - Update a yaml file given a path
 - Update a yaml file given a script file
+- Update creates any missing entries in the path on the fly
+- Create a yaml file given a deep path and value
+- Create a yaml file given a script file
 - Convert from json to yaml
 - Convert from yaml to json
+- Pipe data in by using '-'
 
 ## Read examples
 ```
@@ -111,6 +115,7 @@ will output:
 ```
 
 ## Update examples
+Existing yaml files can be updated via the write command
 
 ### Update to stdout
 Given a sample.yaml file of:
@@ -128,6 +133,31 @@ b:
   c: cat
 ```
 
+### Update from STDIN
+```bash
+cat sample.yaml | yaml w - b.c blah
+```
+
+### Adding new fields
+Any missing fields in the path will be created on the fly.
+
+Given a sample.yaml file of:
+```yaml
+b:
+  c: 2
+```
+then
+```bash
+yaml w sample.yaml b.d[0] "new thing"
+```
+will output:
+```yaml
+b:
+  c: cat
+  d:
+    - new thing
+```
+
 ### Updating yaml in-place
 Given a sample.yaml file of:
 ```yaml
@@ -167,6 +197,51 @@ b:
     - name: Howdy Partner
 ```
 
+And, of course, you can pipe the instructions in using '-':
+```bash
+cat update_instructions.yaml | yaml w -s - sample.yaml
+```
+
+## New Examples
+Yaml files can be created using the 'new' command. This works in the same way as the write command, but you don't pass in an existing Yaml file.
+
+### Creating a simple yaml file
+```bash
+yaml n b.c cat
+```
+will output:
+```yaml
+b:
+  c: cat
+```
+
+### Creating using a create script
+Create scripts follow the same format as the update scripts.
+
+Given a script create_instructions.yaml of:
+```yaml
+b.c: 3
+b.e[0].name: Howdy Partner
+```
+then
+
+```bash
+yaml n -s create_instructions.yaml
+```
+will output:
+```yaml
+b:
+  c: 3
+  e:
+    - name: Howdy Partner
+```
+
+You can also pipe the instructions in:
+
+```bash
+cat create_instructions.yaml | yaml n -s -
+```
+
 ## Converting to and from json
 
 ### Yaml2json

yaml.go

@@ -30,13 +30,14 @@ func main() {
 
 	var cmdRead = createReadCmd()
 	var cmdWrite = createWriteCmd()
+	var cmdNew = createNewCmd()
 
 	var rootCmd = &cobra.Command{Use: "yaml"}
 	rootCmd.PersistentFlags().BoolVarP(&trimOutput, "trim", "t", true, "trim yaml output")
 	rootCmd.PersistentFlags().BoolVarP(&outputToJSON, "tojson", "j", false, "output as json")
 	rootCmd.PersistentFlags().BoolVarP(&inputJSON, "fromjson", "J", false, "input as json")
 	rootCmd.PersistentFlags().BoolVarP(&verbose, "verbose", "v", false, "verbose mode")
-	rootCmd.AddCommand(cmdRead, cmdWrite)
+	rootCmd.AddCommand(cmdRead, cmdWrite, cmdNew)
 	rootCmd.Execute()
 }
 
@@ -87,6 +88,28 @@ a.b.e:
 	return cmdWrite
 }
 
+func createNewCmd() *cobra.Command {
+	var cmdNew = &cobra.Command{
+		Use:     "new [path] [value]",
+		Aliases: []string{"n"},
+		Short:   "yaml n [--script/-s script_file] a.b.c newValueForC",
+		Example: `
+yaml new a.b.c cat
+yaml n a.b.c cat
+yaml n --script create_script.yaml
+      `,
+		Long: `Creates a new yaml w.r.t the given path and value.
+Outputs to STDOUT
+
+Create Scripts:
+Note that you can give a create script to perform more sophisticated yaml. This follows the same format as the update script.
+`,
+		Run: newProperty,
+	}
+	cmdNew.PersistentFlags().StringVarP(&writeScript, "script", "s", "", "yaml script for updating yaml")
+	return cmdNew
+}
+
 func readProperty(cmd *cobra.Command, args []string) {
 	if verbose {
 		backend.SetLevel(logging.DEBUG, "")
@@ -108,6 +131,35 @@ func read(args []string) interface{} {
 	return readMap(parsedData, paths[0], paths[1:len(paths)])
 }
 
+func newProperty(cmd *cobra.Command, args []string) {
+	if verbose {
+		backend.SetLevel(logging.DEBUG, "")
+	}
+	updatedData := newYaml(args)
+	print(updatedData)
+}
+
+func newYaml(args []string) interface{} {
+	var writeCommands map[string]interface{}
+	if writeScript != "" {
+		readData(writeScript, &writeCommands, false)
+	} else if len(args) < 2 {
+		die("Must provide <path_to_update> <value>")
+	} else {
+		writeCommands = make(map[string]interface{})
+		writeCommands[args[0]] = parseValue(args[1])
+	}
+
+	parsedData := make(yaml.MapSlice, 0)
+
+	for path, value := range writeCommands {
+		var paths = parsePath(path)
+		parsedData = writeMap(parsedData, paths, value)
+	}
+
+	return parsedData
+}
+
 func writeProperty(cmd *cobra.Command, args []string) {
 	if verbose {
 		backend.SetLevel(logging.DEBUG, "")

yaml_test.go

@@ -36,6 +36,14 @@ application: MyApp`,
 		formattedResult)
 }
 
+func TestNewYaml(t *testing.T) {
+	result := newYaml([]string{"b.c", "3"})
+	formattedResult := fmt.Sprintf("%v", result)
+	assertResult(t,
+		"[{b [{c 3}]}]",
+		formattedResult)
+}
+
 func TestUpdateYaml(t *testing.T) {
 	result := updateYaml([]string{"sample.yaml", "b.c", "3"})
 	formattedResult := fmt.Sprintf("%v", result)
@@ -48,3 +56,12 @@ func TestUpdateYaml_WithScript(t *testing.T) {
 	writeScript = "instruction_sample.yaml"
 	updateYaml([]string{"sample.yaml"})
 }
+
+func TestNewYaml_WithScript(t *testing.T) {
+	writeScript = "instruction_sample.yaml"
+	result := newYaml([]string{""})
+	formattedResult := fmt.Sprintf("%v", result)
+	assertResult(t,
+		"[{b [{c cat} {e [[{name Mike Farah}]]}]}]",
+		formattedResult)
+}