WebServicesTool¶
Web Services Tool
Web Services Tool queries XML-RPC enabled servers via the “standard” introspection methods and displays a summary of the API. It is implemented in Python using the PyObjC module.
To use the application, simply provide the connection window with an URL to the XML-RPC handler of a web server. If the server at least implements the listMethods() method, the app will display a list of available methods.
Source for both the pyobjc module and the Web Services Tool are available via the pyobjc sourceforge CVS repository.
The source of this application demonstrates
using Python’s network libraries inside a Cocoa app
how to use multi-threading
how to create an NSToolbar
how to use an NSTableView
b.bum bbum@codefab.com
This application has been modified for Twisted. It demonstrates:
using Twisted in a Cocoa app with the threadedselectreactor
how to write responsive single-threaded network applications
note that you will need Twisted 2.x, where x > 0. Currently, this is only available from svn, at revision 13576 or later.
To run the demo: python setup.py py2app open dist/WebServicesTool.app
Sources¶
Main.py¶
# import classes required to start application
import WSTApplicationDelegateClass # noqa: F401
import WSTConnectionWindowControllerClass # noqa: F401
from PyObjCTools import AppHelper
from twisted.internet import cfreactor
cfreactor.install()
# pass control to the AppKit
AppHelper.runEventLoop()
WSTApplicationDelegateClass.py¶
"""
WSTApplicationDelegateClass
An instance of this class is instantiated in the MainMenu.nib default NIB file.
"""
import Cocoa
from PyObjCTools import AppHelper
from twisted.internet import reactor
from WSTConnectionWindowControllerClass import WSTConnectionWindowController
class WSTApplicationDelegate(Cocoa.NSObject):
def newConnectionAction_(self, sender):
"""Action method fired when the user selects the 'new connection'
menu item. Note that the WSTConnectionWindowControllerClass is
defined the first time this method is invoked.
This kind of lazy evaluation is generally recommended; it speeds
app launch time and it ensures that cycles aren't wasted loading
functionality that will never be used.
(In this case, it is largely moot due to the implementation of
applicationDidFinishLaunching_().
"""
WSTConnectionWindowController.connectionWindowController().showWindow_(sender)
def applicationShouldTerminate_(self, sender):
if reactor.running:
reactor.stop()
return False
return True
def applicationDidFinishLaunching_(self, aNotification):
"""Create and display a new connection window"""
reactor.interleave(AppHelper.callAfter)
reactor.addSystemEventTrigger("after", "shutdown", AppHelper.stopEventLoop)
self.newConnectionAction_(None)
WSTConnectionWindowControllerClass.py¶
"""
Instances of WSTConnectionWindowController are the controlling object
for the document windows for the Web Services Tool application.
Implements a standard toolbar.
"""
import string
import types
import Cocoa
# Note about multi-threading.
# Although WST does its network stuff in a background thread, with Python 2.2
# there are still moments where the app appears to hang briefly. This should
# only be noticeable when your DNS is slow-ish. The hang is caused by the
# socket.getaddrinfo() function, which is used (indirectly) when connecting
# to a server, which is a frequent operation when using xmlrpclib (it makes
# a new connection for each request). Up to (and including) version 2.3b1,
# Python would not grant time to other threads while blocking inside
# getaddrinfo(). This has been fixed *after* 2.3b1 was released. (jvr)
import objc
from twisted.internet import defer
from twisted.web.xmlrpc import Proxy
kWSTReloadContentsToolbarItemIdentifier = "WST: Reload Contents Toolbar Identifier"
"""Identifier for 'reload contents' toolbar item."""
kWSTPreferencesToolbarItemIdentifier = "WST: Preferences Toolbar Identifier"
"""Identifier for 'preferences' toolbar item."""
kWSTUrlTextFieldToolbarItemIdentifier = "WST: URL Textfield Toolbar Identifier"
"""Idnetifier for URL text field toolbar item."""
def addToolbarItem(
aController,
anIdentifier,
aLabel,
aPaletteLabel,
aToolTip,
aTarget,
anAction,
anItemContent,
aMenu,
):
"""
Adds an freshly created item to the toolbar defined by
aController. Makes a number of assumptions about the
implementation of aController. It should be refactored into a
generically useful toolbar management utility.
"""
toolbarItem = Cocoa.NSToolbarItem.alloc().initWithItemIdentifier_(anIdentifier)
toolbarItem.setLabel_(aLabel)
toolbarItem.setPaletteLabel_(aPaletteLabel)
toolbarItem.setToolTip_(aToolTip)
toolbarItem.setTarget_(aTarget)
if anAction:
toolbarItem.setAction_(anAction)
if isinstance(anItemContent, Cocoa.NSImage):
toolbarItem.setImage_(anItemContent)
else:
toolbarItem.setView_(anItemContent)
bounds = anItemContent.bounds()
minSize = (100, bounds[1][1])
maxSize = (1000, bounds[1][1])
toolbarItem.setMinSize_(minSize)
toolbarItem.setMaxSize_(maxSize)
if aMenu:
menuItem = Cocoa.NSMenuItem.alloc().init()
menuItem.setSubmenu_(aMenu)
menuItem.setTitle_(aMenu.title())
toolbarItem.setMenuFormRepresentation_(menuItem)
aController._toolbarItems[anIdentifier] = toolbarItem
class WSTConnectionWindowController(Cocoa.NSWindowController):
"""
As per the definition in the NIB file,
WSTConnectionWindowController is a subclass of
NSWindowController. It acts as a NSTableView data source and
implements a standard toolbar.
"""
methodDescriptionTextView = objc.IBOutlet()
methodsTable = objc.IBOutlet()
progressIndicator = objc.IBOutlet()
statusTextField = objc.IBOutlet()
urlTextField = objc.IBOutlet()
__slots__ = (
"_toolbarItems",
"_toolbarDefaultItemIdentifiers",
"_toolbarAllowedItemIdentifiers",
"_methods",
"_methodSignatures",
"_methodDescriptions",
"_server",
"_methodPrefix",
)
@classmethod
def connectionWindowController(self):
"""
Create and return a default connection window instance.
"""
return WSTConnectionWindowController.alloc().init()
def init(self):
"""
Designated initializer.
Returns self (as per ObjC designated initializer definition,
unlike Python's __init__() method).
"""
self = self.initWithWindowNibName_("WSTConnection")
self._toolbarItems = {}
self._toolbarDefaultItemIdentifiers = []
self._toolbarAllowedItemIdentifiers = []
self._methods = []
return self
def awakeFromNib(self):
"""
Invoked when the NIB file is loaded. Initializes the various
UI widgets.
"""
self.retain() # balanced by autorelease() in windowWillClose_
self.statusTextField.setStringValue_("No host specified.")
self.progressIndicator.setStyle_(Cocoa.NSProgressIndicatorSpinningStyle)
self.progressIndicator.setDisplayedWhenStopped_(False)
self.createToolbar()
def windowWillClose_(self, aNotification):
"""
Clean up when the document window is closed.
"""
self.autorelease()
def createToolbar(self):
"""
Creates and configures the toolbar to be used by the window.
"""
toolbar = Cocoa.NSToolbar.alloc().initWithIdentifier_("WST Connection Window")
toolbar.setDelegate_(self)
toolbar.setAllowsUserCustomization_(True)
toolbar.setAutosavesConfiguration_(True)
self.createToolbarItems()
self.window().setToolbar_(toolbar)
lastURL = Cocoa.NSUserDefaults.standardUserDefaults().stringForKey_("LastURL")
if lastURL and len(lastURL):
self.urlTextField.setStringValue_(lastURL)
def createToolbarItems(self):
"""
Creates all of the toolbar items that can be made available in
the toolbar. The actual set of available toolbar items is
determined by other mechanisms (user defaults, for example).
"""
addToolbarItem(
self,
kWSTReloadContentsToolbarItemIdentifier,
"Reload",
"Reload",
"Reload Contents",
None,
"reloadVisibleData:",
Cocoa.NSImage.imageNamed_("Reload"),
None,
)
addToolbarItem(
self,
kWSTPreferencesToolbarItemIdentifier,
"Preferences",
"Preferences",
"Show Preferences",
None,
"orderFrontPreferences:",
Cocoa.NSImage.imageNamed_("Preferences"),
None,
)
addToolbarItem(
self,
kWSTUrlTextFieldToolbarItemIdentifier,
"URL",
"URL",
"Server URL",
None,
None,
self.urlTextField,
None,
)
self._toolbarDefaultItemIdentifiers = [
kWSTReloadContentsToolbarItemIdentifier,
kWSTUrlTextFieldToolbarItemIdentifier,
Cocoa.NSToolbarSeparatorItemIdentifier,
Cocoa.NSToolbarCustomizeToolbarItemIdentifier,
]
self._toolbarAllowedItemIdentifiers = [
kWSTReloadContentsToolbarItemIdentifier,
kWSTUrlTextFieldToolbarItemIdentifier,
Cocoa.NSToolbarSeparatorItemIdentifier,
Cocoa.NSToolbarSpaceItemIdentifier,
Cocoa.NSToolbarFlexibleSpaceItemIdentifier,
Cocoa.NSToolbarPrintItemIdentifier,
kWSTPreferencesToolbarItemIdentifier,
Cocoa.NSToolbarCustomizeToolbarItemIdentifier,
]
def toolbarDefaultItemIdentifiers_(self, anIdentifier):
"""
Return an array of toolbar item identifiers that identify the
set, in order, of items that should be displayed on the
default toolbar.
"""
return self._toolbarDefaultItemIdentifiers
def toolbarAllowedItemIdentifiers_(self, anIdentifier):
"""
Return an array of toolbar items that may be used in the toolbar.
"""
return self._toolbarAllowedItemIdentifiers
def toolbar_itemForItemIdentifier_willBeInsertedIntoToolbar_(
self, toolbar, itemIdentifier, flag
):
"""
Delegate method fired when the toolbar is about to insert an
item into the toolbar. Item is identified by itemIdentifier.
Effectively makes a copy of the cached reference instance of
the toolbar item identified by itemIdentifier.
"""
newItem = Cocoa.NSToolbarItem.alloc().initWithItemIdentifier_(itemIdentifier)
item = self._toolbarItems[itemIdentifier]
newItem.setLabel_(item.label())
newItem.setPaletteLabel_(item.paletteLabel())
if item.view():
newItem.setView_(item.view())
else:
newItem.setImage_(item.image())
newItem.setToolTip_(item.toolTip())
newItem.setTarget_(item.target())
newItem.setAction_(item.action())
newItem.setMenuFormRepresentation_(item.menuFormRepresentation())
if newItem.view():
newItem.setMinSize_(item.minSize())
newItem.setMaxSize_(item.maxSize())
return newItem
def setStatusTextFieldMessage_(self, aMessage):
"""
Sets the contents of the statusTextField to aMessage and
forces the fileld's contents to be redisplayed.
"""
if not aMessage:
aMessage = "Displaying information about %d methods." % len(self._methods)
# All UI calls should be directed to the main thread
self.statusTextField.setStringValue_(aMessage)
def reloadData(self):
"""Tell the main thread to update the table view."""
self.methodsTable.reloadData()
def startWorking(self):
"""Signal the UI there's work going on."""
self.progressIndicator.startAnimation_(self)
def stopWorking(self):
"""Signal the UI that the work is done."""
self.progressIndicator.stopAnimation_(self)
@objc.IBAction
def reloadVisibleData_(self, sender):
"""
Reloads the list of methods and their signatures from the
XML-RPC server specified in the urlTextField. Displays
appropriate error messages, if necessary.
"""
url = self.urlTextField.stringValue()
self._methods = []
self._methodSignatures = {}
self._methodDescriptions = {}
if not url:
self.window().setTitle_("Untitled.")
self.setStatusTextFieldMessage_("No URL specified.")
return
self.window().setTitle_(url)
Cocoa.NSUserDefaults.standardUserDefaults().setObject_forKey_(url, "LastURL")
self.setStatusTextFieldMessage_("Retrieving method list...")
self.getMethods(url)
@objc.python_method
def getMethods(self, url):
_server = self._server = Proxy(url.encode("utf8"))
self.startWorking()
return (
_server.callRemote("listMethods")
.addCallback(
# call self.receivedMethods(result, _server, "") on success
self.receivedMethods,
_server,
"",
)
.addErrback(
# on error, call this lambda
lambda e: _server.callRemote("system.listMethods").addCallback(
# call self.receievedMethods(result, _server, "system.")
self.receivedMethods,
_server,
"system.",
)
)
.addErrback(
# log the failure instance, with a method
self.receivedMethodsFailure,
"listMethods()",
)
.addBoth(
# stop working nomatter what trap all errors (returns None)
lambda n: self.stopWorking()
)
)
@objc.python_method
def receivedMethodsFailure(self, why, method):
self._server = None
self._methodPrefix = None
self.setStatusTextFieldMessage_(
("Server failed to respond to %s. " "See below for more information.")
% (method,)
)
# log.err(why)
self.methodDescriptionTextView.setString_(why.getTraceback())
@objc.python_method
def receivedMethods(self, _methods, _server, _methodPrefix):
self._server = _server
self._methods = _methods
self._methodPrefix = _methodPrefix
self._methods.sort()
self.reloadData()
self.setStatusTextFieldMessage_(
"Retrieving information about %d methods." % (len(self._methods),)
)
# we could make all the requests at once :)
# but the server might not like that so we will chain them
d = defer.succeed(None)
for index, aMethod in enumerate(self._methods):
d.addCallback(self.fetchMethodSignature, index, aMethod).addCallbacks(
callback=self.processSignatureForMethod,
callbackArgs=(index, aMethod),
errback=self.couldntProcessSignatureForMethod,
errbackArgs=(index, aMethod),
)
return d.addCallback(
lambda ig: self.setStatusTextFieldMessage_(None)
).addCallback(lambda ig: self.reloadData())
@objc.python_method
def fetchMethodSignature(self, ignore, index, aMethod):
if (index % 5) == 0:
self.reloadData()
self.setStatusTextFieldMessage_(
"Retrieving signature for method %s (%d of %d)."
% (aMethod, index, len(self._methods))
)
return self._server.callRemote(self._methodPrefix + "methodSignature", aMethod)
@objc.python_method
def processSignatureForMethod(self, methodSignature, index, aMethod):
signatures = None
if not len(methodSignature):
return
for aSignature in methodSignature:
if (type(aSignature) == types.ListType) and ( # noqa: E721
len(aSignature) > 0
):
signature = "{} {}({})".format(
aSignature[0],
aMethod,
string.join(aSignature[1:], ", "),
)
else:
signature = aSignature
if signatures:
signatures = signatures + ", " + signature
else:
signatures = signature
self._methodSignatures[aMethod] = signatures
@objc.python_method
def couldntProcessSignatureForMethod(self, why, index, aMethod):
# log.err(why)
self._methodSignatures[aMethod] = "<error> {} {}".format(
aMethod,
why.getBriefTraceback(),
)
def tableViewSelectionDidChange_(self, sender):
"""
When the user selects a remote method, this method displays
the documentation for that method as returned by the XML-RPC
server. If the method's documentation has been previously
queried, the documentation will be retrieved from a cache.
"""
selectedRow = self.methodsTable.selectedRow()
selectedMethod = self._methods[selectedRow]
def displayMethod(methodDescription):
self.setStatusTextFieldMessage_(None)
self.methodDescriptionTextView.setString_(methodDescription)
self.fetchMethodDescription(selectedMethod).addCallback(displayMethod)
@objc.python_method
def fetchMethodDescription(self, aMethod):
desc = self._methodDescriptions
if aMethod in desc:
return defer.succeed(desc[aMethod])
def cacheDesc(v):
v = v or "No description available."
desc[aMethod] = v
return v
def _stopWorking(v):
self.stopWorking()
return v
desc[aMethod] = "<description is being retrieved>"
self.setStatusTextFieldMessage_(f"Retrieving signature for method {aMethod}...")
self.startWorking()
return (
self._server.callRemote(self._methodPrefix + "methodHelp", aMethod)
.addCallback(_stopWorking)
.addCallback(cacheDesc)
)
def numberOfRowsInTableView_(self, aTableView):
"""
Returns the number of methods found on the server.
"""
return len(self._methods)
def tableView_objectValueForTableColumn_row_(
self, aTableView, aTableColumn, rowIndex
):
"""
Returns either the raw method name or the method signature,
depending on if a signature had been found on the server.
"""
aMethod = self._methods[rowIndex]
if aMethod in self._methodSignatures:
return self._methodSignatures[aMethod]
else:
return aMethod
def tableView_shouldEditTableColumn_row_(self, aTableView, aTableColumn, rowIndex):
# don't allow editing of any cells
return 0
setup.py¶
"""
Script for building the example.
Usage:
python3 setup.py py2app
"""
from setuptools import setup
setup(
app=["Main.py"],
data_files=["English.lproj", "Preferences.png", "Reload.png", "WST.png"],
options={
"py2app": {
"iconfile": "WST.icns",
"plist": {"CFBundleName": "Web Services Tool"},
}
},
setup_requires=["py2app", "pyobjc-framework-Cocoa"],
)