[Grok-dev] What's the best practise to store images / files in blob storage

[Jan-Wijbrand Kolman]

Somewhat late to this aprty :)

On 2/27/12 16:53 , lzdych wrote:
> Finally I sort it out wapp a great help on IRC from trollfot and goschtl (thx
> a lot guys!).
> 
> In my almost vanila environment created by grokproject (grok 1.4) I just had
> to:
> 
> 1. pin these versions (IMPORTANT):
> megrok.chameleon = 0.5.2
> Chameleon = 1.2.13
> 
> 2. add the following deps into setup.py (install_requires):
> 'zeam.form.base',
> zeam.form.ztk
> dolmen.blob
> dolmen.widget.file
> dolmen.widget.image
> 
> 3. rewrite my form from grokcore.formlib based into zeam.form.ztk based
> as you can see in the following example:

We are using blobfile wapp grokcore.formlib. Something like so:

interfaces.py:

class ILogo(dolmen.blob.IBlobFile):
    pass

class ILayoutSettings(ISettings):
    logo = zope.schema.Object(
        schema=ILogo, title=u'Logo', required=False,
        description=_(u'Image file'))

settings.py:

class Logo(dolmen.blob.BlobFile):
    grok.implements(app.interfaces.ILogo)

    def __init__(self, data, filename):
        super(Logo, self).__init__(data, filename=filename)
	
class LayoutSettings(Settings):
    grok.implements(app.interfaces.ILayoutSettings)
    grok.name('layout')
    grok.provides(app.interfaces.ILayoutSettings)
    grok.title(_(u'Layout'))
    grok.traversable('logo')
    grok.order(30)

    # the located property ensures the __parent__/__name__
    # contract for the logo.
    logo = app.interfaces.LocatedProperty('logo')

browser.py:

class LogoInputWidget(zope.formlib.widgets.FileWidget):
    def _toFieldValue(self, input):
        if not isinstance(input, zope.publisher.browser.FileUpload):
            return self.context.missing_value
        return app.configuration.Logo(
            input.read(), filename=input.filename)
	
class EditLayoutSettings(Edit):
    grok.context(app.interfaces.ILayoutSettings)

    def update(self):
        self.form_fields = grok.Fields(app.interfaces.ILayoutSettings)
        self.form_fields['logo'].custom_widget = LogoInputWidget

HTH,
regards, jw