From e1c3f36cc413dc826673a61c619421428914073c Mon Sep 17 00:00:00 2001 From: Jack Jansen Date: Mon, 9 Sep 1996 01:48:40 +0000 Subject: Documented preliminary CGI applet. --- Mac/Demo/cgi.html | 86 +++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 86 insertions(+) create mode 100644 Mac/Demo/cgi.html diff --git a/Mac/Demo/cgi.html b/Mac/Demo/cgi.html new file mode 100644 index 0000000..3932b28 --- /dev/null +++ b/Mac/Demo/cgi.html @@ -0,0 +1,86 @@ +Using python to create CGI scripts + +

Using python to create CGI scripts

+ +In this document we will (eventually) explain how to create Python CGI scripts +for use with NetPresenz and probably other Mac-based HTTP servers too. +Since CGI scripts are AppleEvent servers on the mac we will also learn +a little about general AppleEvent server programming and about applet +debugging.

+ +

Note that the current setup is very preliminary, and hence +itis probably not wise to base your strategic products on the information +in this document:-) In stead, play with the code here and join the +pythonmac-sig, where +we I would like to have a discussion on a real design for a Mac CGI framework +(preferrably something that will make CGI scripts portable to unix and other +platforms). +

+ +

AppleEvent servers

+ +Since AppleEvent clients are easier to write and understand than servers +you should probably read the section on Open Scripting +clients in Python first.

+ +Next, let us have a look at the AE Server framework, +MiniAEFrame.py. +This file contains two classes, MiniApplication and AEServer. +MiniApplication is a tiny replacement for FrameWork.Application, +suitable if your application does not need windows and such. + +

Actually, Framework.Application has a problem for AE Servers, +due to the way it expects to be quit through an exception, and raising an exception +while inside an Apple Event handler is a very bad idea. This will be fixed. +

+ +AEServer is a bit of glue that does part of the appleevent decoding for you. You +call installaehandler passing it the class and id (4-char strings) +of the event you have a handler for and the handler callback routine. When the +appleevent occurs your callback is called with the right arguments. For now, +your argument names are the 4-char values used internally by Open Scripting, +eventually there will be a translation similar to what the generated OSA client +suites provide.

+ +You can test AEServer by double-clicking it. It will react to the standard +run/open/print/quit OSA commands. If it is running as a normal python script and you +drag a file onto the interpreter the script will tell you what event is got.

+ +

A Minimal CGI script

+ +To try a CGI script you will first need a http server. I have used the +shareware +NetPresenz +by Peter Lewis +(don't forget to pay if you give it more than a test run!). Install your +http server, and make sure that it can serve textual documents.

+ +Next, let us have a look at our example CGI scripts. CGI scripts have to be +applications, so we will have to make an applet as explained in +example 2. Our applet code, +cgitest.cgi.py is a rather minimal execfile +statement. The reason for this is debugging: the real code is in +realcgitest.py, and this way you do not have +to run mkapplet again every time you change the code. Rename realcgitest.py +to cgitest.cgi.py once you are satisfied that it works.

+ +The resource file is not very special, with one exception: since we want to do +our own appleevent handling we don't want the Python initialization code to +create argc and argv for use, since this might gobble up any appleevents we are +interested in. For this reason we have included a 'Popt' resource that disables +the argv initialization. An easy way to create this resource is to drop +the .rsrc file (or the finished applet, if you like) onto +EditPythonPrefs and set the "no argv processing" option.

+ +The code itself is actually not too complicated either. We install handlers +for "open application" and "quit" (stolen from the test code in MiniAEFrame) +and the "WWW\275"/"sdoc" event, the event sent on CGI execution. +The cgi handler pretty-prints the CGI arguments in HTML and returns the whole +string that is to be passed to the client. The actual parameters passed +are explained in +http://www.biap.com/datapig/mrwheat/cgi_params.html.

+ +To test the script drop cgitest.cgi.py onto mkapplet, +move the resulting cgitest.cgi to somewhere where it is reachable +by NetPresenz, and point your web browser towards it. -- cgit v0.12