[Zope] Pass objects from template to template via HTML forms.

[Tino Wildenhain]

Am Dienstag, den 05.07.2005, 11:05 +0200 schrieb Negroup -:
> 2005/7/5, Tino Wildenhain <tino at wildenhain.de>:
> [cut]
> 
> > So best option I see is to not pass the object but rather
> > pass the reference to the object. You can resolve
> > it via restrictedTraverse('/path/from/form')
> 
> I think I can't apply your solution. restrictedTraverse asks for a
> path, and then it supposes that the object is stored inside ZODB. This
> is not my case. Let me provide a minimanl explaination about how my
> application is structured.
> 
> 1. A user can uploads a zipped file via HTML form in "upload_zip" ZPT.
> The action of the form points to check_zip, an External Method that
> checks for validity of each file inside the archive.
> 
> 2. check_zip returns to upload_zip a tuple containing two elements:
> True or False (based on the correctness of archive) and the object
> itself, via self parameter.
> 
> 3. after the external method has been called, upload_zip shows other 2
> forms that the user will use to abort operation or to continue the
> process. The form to continue will pass the object to another external
> method in order to compute the result. This is the step where I
> encounter the problem, I can't pass object.
> 
> This should explain why I haven't the object stored inside ZODB.
> 
> Probably the solution would be to store the uploaded object inside a
> temporary area of ZODB and then I'll be able to do all the tasks I
> need.
> 
> Any further consideration/hints?

Well yes, thats very easy. Just store your (compressed or not)
HTML data (since its a string after all and not such a complex
object) in a hidden form field (base64 encoded for example) ->

filedata=htmldata.encode("base64")

and the other parts of your form as you wish. Maybe you prepare
the data in a script and call the ZPT from it:

return context.yourZPT(filedata=filedata,somestatus=whatever)

and use: <input type="hidden" tal:attributes="value options/filedata"
type="text" /> in your ZPT.

When the request returns, use: htmldata=filedata.decode("base64")

alternatively you can just store the data in REQUEST.SESSION
to keep it on server (but watch the memory usage)

-- 
Tino Wildenhain <tino at wildenhain.de>