Re: [Zope3-Users] Custom Image Widget - Solution

[Adam Summers]

Hi Tom & all, First of all, thanks for the help. Its much appreciated :) I understand what you're suggesting, but I needed a way to do it without traversal. For what I'm trying to do, the interface and implementation of the zope objects need to be as simple as possible - anything fancy needs to be (if possible) outside the interface/implementation (like in a widget) I attached what I ended up doing for the widget and the form. Its nothing radical, and very crude, but it works. (The supdoc attribute in the form is defined as supDoc = List(title=_(u"Supporting Docs List"), value_type=Object(IImage, __name__='ImgItem', title=_(u"Image"))) > > anyway, hope this helps anyone who gets stuck on this sort of thing. Again, thanks. Adam Tom Dossis wrote: Adam Summers wrote: Hi Tom & Widget Afficionados. Thanks for the help so far. My problem is now this: From this code (which Tom supplied), how do I code the logic (in bold) def _toFieldValue(self, input): data = "" self)._toFieldValue(input) if data is not None: img = Image(data) notify(ObjectCreatedEvent(img)) return img *else: #data is None, ie. the File input field was left blank and we don't want to #replace the current value of the Image Widget with an empty value. currentImg = the Image object which the field is being rendered for return currentImg * I can't rely on field = self.context image = field.get(field.context) logic to find the data, because my schema can contain: class Iclaim(IContained): """Claim""" supDoc = List(title=_(u"Supporting Docs List"), value_type=Object(IImage, __name__='ImgItem', title=_(u"Image"))) img = Object(IImage, title=_(u"Single img"), required=False) And hence, the self.context.context points to the claim object, not the list inside when rendering supDoc Hi Adam, You can rely on: field = self.context image = field.get(field.context) because the widget is for an attribute object of type IImage. Your supDoc attribute object is a List Type - not an IImage. In this case you'd need another widget - for a list of IImage. I wouldn't been too keen to tackle the html work effort and would probably look at an alternative along the lines of... class IImageList(IContainer): contains(zope.app.image.interfaces.IImage) class IClaim(IContained): supDoc=Object(schema=IImageList) Make supDoc traversable, then you wouldn't need the custom widget here because you can store Images directly in supDoc view with the browser:containerView's.

from zope.app.form import CustomWidgetFactory
from zope.app.form.browser.widget import DisplayWidget, SimpleInputWidget, 
renderElement
from zope.app.form.browser.sequencewidget import ListSequenceWidget, 
SequenceDisplayWidget
from zope.app.file.image import Image
from zope.app.form.interfaces import ConversionError
from base64 import b64encode, b64decode



class MyImageDisplayWidget(DisplayWidget):
        
        def __call__(self):

                mycontent = u"(No Image)"

                if self._renderedValueSet() and self._data is not None:
                        mycontent = buildHTMLImg(self._data.data)
                return mycontent

MyImageListDisplayWidget = CustomWidgetFactory(SequenceDisplayWidget, subwidget 
= MyImageDisplayWidget)

class MyImageInputWidget(SimpleInputWidget):
    """File Widget"""
    type = 'file'
    
    def _toFieldValue(self, input):
        if (input is None or input == ''):
                try:
                        imgData =  b64decode(self.request.form[self.name + 
'.data'])
                        return Image(imgData)
                except AttributeError, e:
                        return self.context.missing_value
        else:   
                try:
                    seek = input.seek
                    read = input.read
                except AttributeError, e:
                    raise ConversionError(_('Form input is not a file object'), 
e)
                else:
                    seek(0)
                    data = read()
                    if data or getattr(input, 'filename', ''):
                        return Image(data)
                    else:
                        return self.context.missing_value

        
    def __call__(self):
        elem = renderElement(self.tag,
                                 type=self.type,
                                 name=self.name,
                                 id=self.name,
                                 extra=self.extra)
        input_widget = elem

        try: 
                img_widget = buildHTMLImg(self._data.data)
                elem = renderElement(self.tag,
                         type='hidden',
                         name=self.name+'.data',
                         id=self.name,
                         extra='value="' + b64encode(self._data.data) + '"') 
                input_widget = img_widget + input_widget +elem
                return input_widget
        except AttributeError:
                return input_widget     
        
MyImageInputListWidget = CustomWidgetFactory(ListSequenceWidget, subwidget = 
MyImageInputWidget)    


def buildHTMLImg(data):
        return "<img src=\"data:image/gif;base64, " + b64encode(data) + " \" />"

from zope.formlib import form
from as.claim.interfaces import Iclaim
from as.claim.claim import claim
from as.widget.browser.widgets import MyImageListDisplayWidget, 
MyImageInputListWidget

def _(arg): #yes this is a hack. to be modified
        return arg

class claimAddForm(form.AddForm):
        form_fields = form.Fields(Iclaim).omit('__name__', '__parent__')
        form_fields['supDoc'].custom_widget =  MyImageInputListWidget

        def create(self, data):
                return claim(**data)

class claimEditForm(form.EditForm):
        form_fields = form.Fields(Iclaim).omit('__name__', '__parent__')
        form_fields['supDoc'].custom_widget =  MyImageInputListWidget
        
        [EMAIL PROTECTED](_("Apply"), condition=form.haveInputWidgets)
        #def handle_edit_action(self, action, data):
        #       if self.context.modify(data):
        #               self.status = _(u"Object Updated")
        #       else:
        #               self.status = _(u"No Changes")

class claimDisplayForm(form.DisplayForm):
        form_fields = form.Fields(Iclaim).omit('__name__', '__parent__')

        #form_fields['img'].custom_widget = MyImageDisplayWidget
        form_fields['supDoc'].custom_widget = MyImageListDisplayWidget
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