Zope 3 wiki → Developer Info → Proposals →
last edited 3 years ago by rogerineichen
created: 2005-01-20

IFile refactoring

IFile? refactoring

Status

IsDraft

Author

Roger Ineichen

Problem/Proposal

Constraints of field data in IFile? does'nt fit. The interface field Bytes ignores the possible FileChunk? as value we get on bigger files.

We allready added a branch called for the refactoring. The branch is called jhauser-filefieldwidget.

Goals

  • Fix constraints in data schema field (Bytes), we could have FileChunk? objects as values.
  • Handle fileupload via session. The widget should read the file upload information from the session.
  • Make Refresh method in edit form working. Now the value of the file upload field (input type=file) get lost on refresh.

Proposed Solution

Refactoring, extend and/or add different parts

IFile? interface: 

      class IFile(Interface):

          contents = Mime(
              title = _(u'The mime data'),
              description = _(u'The mime data, which can be read as a file.'),
              default='',
              missing_value='',
              required=False,
              )

          data = ... for backward compatibility

IMime? interface: 

      class IMime(Interface):

          contentType = MimeType(
              title = _(u'Content Type'),
              description=_(u'The content type identifies the type of data.'),
              default='',
              required=False,
              missing_value=''
              )

          encoding = MimeDataEncoding(
              title = _(u'Encoding type'),
              description=_(u'The encoding of the data if it is text.'),
              default='',
              required=False,
              missing_value=''
              )

          data = MimeData(
              title=_(u'Data'),
              description=_(u'The actual content of the object.'),
              default='',
              missing_value='',
              required=False,
              )

IFile?/contents/Mime field - MimeWidget?:

The input widget is like a object widget which renders it's information from the schema IMime?. The widget is used for the field contents in the interface IFile?. It's more a view the a widget like to object widget implementation.

This widget directly handles:
  • extract information about the fileupload to the session

The subwidgets of the schema IMime? are not simply widgets like TextLine? etc, they have to support session reading:

IMime?/contentType/MimeType? - MimeTypeWidget?:

  • set the contentType (mime-type) via session formation

IMime?/encoding/MimeDataEncoding? - MimeDataEncodingWidget?:

  • set the encoding if given and type is a text format

IMime?/data/MimeData? - MimeDataWidget? (IInputWidget?):

The widget is used in the IMime? schema on the data field The interface field is called MimeData?

  • render input field of type=file
  • stores FileChunk? or str to the value (field data)
  • don't override data value if upload is empty

IMime?/data/MimeData? - MimeDataDisplayWidget? (IDisplayWidget?):

We need different widgets for displaying files. The different usecases are:

  • render a href links
  • render img images tags
  • render text content

Risks

Backward compatiblility


comments:

Make Refresh method in edit form working. --rogerineichen, 2005/01/27 17:42 EST reply
Set the file upload path/filename back on the file input field on refreshing the form isn't possible. The HTML standard says it's possible, but all browser restrict the file input field for security reason.



( 97 subscribers )