Implement helper arguments functionality; Close #21

For this purpose was introduced concept of the helpers list instead
of just one helper.

data/applications.xml

@@ -46,6 +46,19 @@
   -         <app name="app_name3" />
   -     </group>
   -
+  - Helpers:
+  -     Obviously you can specify the helper and set the command for restarting
+  -     the application. I.e. helper="myapp restart".
+  -     What is actually more interesting is that you can add various arguments.
+  -
+  -     <app name="app_name" helper="kill {PID}" />
+  -
+  - Helper arguments:
+  -     * {PNAME} - Name of the process
+  -     * {NAME}  - Name of the application
+  -     * {PID}   - Process ID
+  -     * {EXE}   - Process binary
+  -
   -->
 
 <applications>

tracer/resources/applications.py

@@ -25,6 +25,7 @@
 from tracer.resources.lang import _
 from tracer.resources.processes import Processes
 import os
+import re
 
 
 class Applications:
@@ -174,6 +175,7 @@ def update(self, values):
 			values = values._attributes
 		self._attributes.update(values)
 
+	# @TODO rename to helper_format
 	@property
 	def helper(self):
 		helper = self._attributes["helper"]
@@ -182,6 +184,36 @@ def helper(self):
 				helper = "sudo " + helper
 		return helper
 
+	@property
+	def helper_contains_formating(self):
+		return bool(re.search("\{.*\}", self.helper))
+
+	@property
+	def helper_contains_name(self):
+		return bool(re.search("\{NAME\}", self.helper))
+
+	@property
+	def helpers(self):
+		"""
+		Return the list of helpers which describes how to restart the application.
+		When no ``helper_format`` was described, empty list will be returned.
+		If ``helper_format`` contains process specific arguments such a {PID}, etc.
+		list will contain helper for every application instance.
+		In other cases, there will be just one helper in the list.
+		"""
+		helpers = []
+		if not self.helper_contains_formating:
+			helpers.append(self.helper)
+		else:
+			for process in self.instances:
+				helpers.append(self.helper.format(
+					NAME=self.name,
+					PNAME=process.name,
+					PID=process.pid,
+					EXE=process.exe,
+				))
+		return helpers
+
 	@property
 	def instances(self):
 		return Processes.all().filtered(lambda process: process.name == self.name)

tracer/views/default.py

@@ -1,6 +1,7 @@
 from . import View
 from tracer.resources.lang import _
 from tracer.views.note_for_hidden import NoteForHiddenView
+import re
 
 
 class DefaultView(View):
@@ -16,7 +17,10 @@ def render(self):
 		if len(with_helpers):
 			print "  " + _("restart_using_helpers")
 			for application in with_helpers.sorted("helper"):
-				print "      " + application.helper
+				helpers = "; ".join(application.helpers)
+				if application.helper_contains_formating and not application.helper_contains_name:
+					helpers += "  # {}".format(application.name)
+				print "      " + helpers
 
 			if without_helpers:
 				print ""

tracer/views/helper.py

@@ -44,7 +44,8 @@ def render(self):
 			if not self.args.affected_by:
 				print "        {app_name} does not need restarting".format(app_name=self.args.application.name)
 			else:
-				print "        {how_to_restart}".format(how_to_restart=self.args.application.helper)
+				for helper in self.args.application.helpers:
+					print "        {how_to_restart}".format(how_to_restart=helper)
 
 	def render_affected_by(self):