adde .onArgs(..) and .onNoArgs(..) pre-parsing events...

Signed-off-by: Alex A. Naanou <alex.nanou@gmail.com>

ADVANCED.md

@@ -47,6 +47,8 @@ For basics see [README.md](./README.md)
 		- [`THEN` / `STOP`](#then--stop)
 		- [`ParserError(..)`](#parsererror)
 		- [`Parser(..)`](#parser)
+			- [`<parser>.onArgs(..)`](#parseronargs)
+			- [`<parser>.onNoArgs(..)`](#parseronnoargs)
 			- [`<parser>.then(..)`](#parserthen)
 			- [`<parser>.stop(..)`](#parserstop)
 			- [`<parser>.error(..)`](#parsererror-1)
@@ -643,6 +645,38 @@ Parser(<spec>)
 See [`<parser>(..)`](#parser-1) for more info.
 
 
+#### `<parser>.onArgs(..)`
+
+Add callback triggered when one or more arguments are passed to the parser.
+```
+<parser>.onArgs(<callback>)
+	-> <parser>
+```
+
+```
+callback(<args>)
+	-> <obj>
+```
+
+Note that this is triggered _before_ parsing begins.
+
+
+#### `<parser>.onNoArgs(..)`
+
+Add callback triggered when no arguments are passed to the parser.
+```
+<parser>.onNoArgs(<callback>)
+	-> <parser>
+```
+
+```
+callback(<args>)
+	-> <obj>
+```
+
+Note that this is triggered _before_ parsing begins.
+
+
 #### `<parser>.then(..)`
 
 Add callback to `then` "event".

README.md

@@ -65,6 +65,7 @@ This code is an evolution of that parser.
 		- [Nested parsers](#nested-parsers)
 		- [Stopping](#stopping)
 		- [Error reporting](#error-reporting)
+		- [Before parsing begins](#before-parsing-begins)
 		- [Handling the result](#handling-the-result)
 		- [Calling the script](#calling-the-script)
 	- [Advanced docs](#advanced-docs)
@@ -479,6 +480,25 @@ And to close things off for the `<spec>` ;)
 })
 ```
 
+### Before parsing begins
+
+The `<parser>` can notify the user if any arguments were passed or not before the parsing starts:
+
+- [`<parser>.onArgs(..)`](./ADVANCED.md#parseronargs) triggered when one or 
+  more arguments were passed
+  ```javascript
+  .onArgs(function(args){
+	  console.log('### input arguments:', args) })
+  ```
+
+- [`<parser>.onNoArgs(..)`](./ADVANCED.md#parseronnoargs) triggered when no 
+  arguments were passed
+  ```javascript
+  .onNoArgs(function(args){
+	  console.log('### no arguments passed.') })
+  ```
+
+
 ### Handling the result
 
 The `<parser>` will call different sets of callbacks on different stop conditions:

argv.js

@@ -15,6 +15,9 @@
 * Repo and docs:
 * 	https://github.com/flynx/argv.js
 *
+* TODO:
+* 	.onNoArgs(..) / onArgs(..) callbacks...
+*
 *
 **********************************************************************/
 ((typeof define)[0]=='u'?function(f){module.exports=f(require)}:define)
@@ -95,8 +98,12 @@ module.extra = {}
 //		-> func
 //
 //
-//	func(..)
+//	Bind a callback...
+//	func(callback)
 //		-> this
+//
+//	Trigger callbacks...
+//	func(..)
 //		-> res 
 //
 //	pre_action(...args)
@@ -911,7 +918,17 @@ object.Constructor('Parser', {
 		return this },
 
 
-	// Post parsing callbacks...
+	// Pre-parsing callbacks...
+	//
+	//	.onArgs(callback(args))
+	//
+	//	.onNoArgs(callback())
+	//
+	onArgs: afterCallback('onArgs'),
+	onNoArgs: afterCallback('onNoArgs'),
+	
+
+	// Post-parsing callbacks...
 	//
 	// 	.then(callback(unhandled, root_value, rest))
 	//
@@ -954,6 +971,7 @@ object.Constructor('Parser', {
 		var that = this
 		var parsed = Object.create(this)
 		var opt_pattern = parsed.optionInputPattern
+		// prep argv...
 		var rest = parsed.rest = 
 			argv == null ?
 				(typeof(process) != 'unhandled' ?
@@ -973,7 +991,6 @@ object.Constructor('Parser', {
 		if(main != null && rest[0] == process.execPath){
 			rest.splice(0, 2)
 			rest.unshift(main) }
-
 		// script stuff...
 		var script = parsed.script = rest.shift()
 		var basename = script.split(/[\\\/]/).pop() 
@@ -981,6 +998,11 @@ object.Constructor('Parser', {
 		parsed.scriptPath = script.slice(0, 
 			script.length - parsed.scriptName.length)
 
+		// call the pre-parse handlers...
+		rest.length == 0 ?
+			this.onNoArgs(rest)
+			: this.onArgs(rest)
+
 		// helpers...
 		// XXX should this pass the error as-is to the API???
 		var handleError = function(reason, arg, rest){

examples/options.js

@@ -148,16 +148,17 @@ argv.Parser({
 		handler: function(){
 			throw 'something went really wrong.' } },
 })
+.onArgs(function(args){
+  console.log('### input arguments:', args) })
+.onNoArgs(function(args){
+  console.log('### no arguments passed.') })
 .then(function(unhandled, root_value, rest){
 	console.log('### finished normally.')
-	console.log(this)
-})
+	console.log(this) })
 .stop(function(arg, rest){
-	console.log(`### stopped at ${arg}.`)
-})
+	console.log(`### stopped at ${arg}.`) })
 .error(function(reason, arg, rest){
-	console.log(`### something went wrong when parsing ${arg}.`)
-})
+	console.log(`### something went wrong when parsing ${arg}.`) })
 
 
 // run the parser...

package.json

@@ -1,6 +1,6 @@
 {
   "name": "ig-argv",
-  "version": "2.13.2",
+  "version": "2.14.0",
   "description": "simple argv parser",
   "main": "argv.js",
   "scripts": {
@@ -28,5 +28,6 @@
   "devDependencies": {
     "colors": "^1.4.0",
     "ig-test": "^1.4.3"
-  }
+  },
+  "vim-cfg": " vim:set ts=2 sw=2 expandtab : "
 }