Example

We are going to develop here a small example, to demonstrate the use of dolmen.widget.image. First, we instanciate our test model and add an image field to the object:

>>> class Mammoth(object):
...     pass

>>> import dolmen.file
>>> import grokcore.component as grok
>>> from zope.interface import Interface, alsoProvides
>>> from zope.schema.fieldproperty import FieldProperty

>>> class IMammothId(Interface):
...   """Even mammoths need an ID card"""
...   picture = dolmen.file.ImageField(title=u'Luggages')

>>> manfred = Mammoth()
>>> manfred.picture = None
>>> alsoProvides(manfred, IMammothId)

The picture is now set on our Mammoth. We create a form to try and edit the picture field:

>>> from zeam.form.ztk import Form, Fields

>>> class EditMammoth(Form):
...    grok.name('edit')
...    grok.context(IMammothId)
...    ignoreContent = False
...    fields = Fields(IMammothId)

>>> grok.testing.grok_component('edit', EditMammoth)
True

We persist our Mammoth to get a located mammoth with an URL:

>>> from zope.component.hooks import getSite
>>> root = getSite()
>>> root['manfred'] = manfred
>>> manfred = root['manfred']

We can call the edit form on our persisted object:

>>> from zope.component import getMultiAdapter
>>> from zope.publisher.browser import TestRequest

>>> request = TestRequest()

>>> form = getMultiAdapter((manfred, request), name='edit')
>>> form.updateWidgets()
>>> print form.fieldWidgets.get('form.field.picture').render()
<div id="form-field-picture">
    <input type="file" id="form-field-picture-input"
             name="form.field.picture" />
</div>

Now, let's try with a fake value:

>>> manfred.picture = "some fake image"
>>> form = getMultiAdapter((manfred, request), name='edit')
>>> form.updateWidgets()

>>> print form.fieldWidgets.get('form.field.picture').render()
<div id="form-field-picture">
  <div>
    <div class="widget-image-preview">
      <img src="http://127.0.0.1/manfred/++thumbnail++picture.preview"
           title="Download" />
    </div>
    <p class="file-info">
      <a class="filename"
         href="http://127.0.0.1/manfred/++download++picture">Download</a>
    </p>
  </div>
  <div>
    <input type="radio" value="keep" checked="checked"
           class="noborder" name="form.field.picture.action"
           onclick="document.getElementById('form-field-picture-input').disabled=true"
           id="form-field-picture-action" />
    <label for="form-field-picture-action">Keep existing file</label>
    <br />
    <input type="radio" value="delete" class="noborder"
           name="form.field.picture.action"
           onclick="document.getElementById('form-field-picture-input').disabled=true"
           id="form-field-picture-delete" />
    <label for="form-field-picture-delete">Delete existing file</label>
    <br />
    <input type="radio" value="replace" class="noborder"
           name="form.field.picture.action"
           onclick="document.getElementById('form-field-picture-input').disabled=false"
           id="form-field-picture-replace" />
        <label for="form-field-picture-replace">Replace with new file</label>
  </div>
  <div>
    <input type="file" id="form-field-picture-input"
           name="form.field.picture" />
    <script type="text/javascript">document.getElementById('form-field-picture-input').disabled=true;</script>
  </div>
</div>

With non persistent objects (which don't resolve to an URL), no preview is displayed. If we can't resolve to an URL, we can't serve the thumbnail or download the data:

>>> judith = Mammoth()
>>> judith.picture = "Fake image data"
>>> alsoProvides(judith, IMammothId)

>>> form = getMultiAdapter((judith, request), name='edit')
>>> form.updateWidgets()
>>> print form.fieldWidgets.get('form.field.picture').render()
<div id="form-field-picture">
  <div>
    <input type="radio" value="keep" checked="checked"
           class="noborder" name="form.field.picture.action"
           onclick="document.getElementById('form-field-picture-input').disabled=true"
           id="form-field-picture-action" />
    <label for="form-field-picture-action">Keep existing file</label>
    <br />
    <input type="radio" value="delete" class="noborder"
           name="form.field.picture.action"
           onclick="document.getElementById('form-field-picture-input').disabled=true"
           id="form-field-picture-delete" />
    <label for="form-field-picture-delete">Delete existing file</label>
    <br />
    <input type="radio" value="replace" class="noborder"
           name="form.field.picture.action"
           onclick="document.getElementById('form-field-picture-input').disabled=false"
           id="form-field-picture-replace" />
        <label for="form-field-picture-replace">Replace with new file</label>
  </div>
  <div>
    <input type="file" id="form-field-picture-input"
           name="form.field.picture" />
    <script type="text/javascript">document.getElementById('form-field-picture-input').disabled=true;</script>
  </div>
</div>

Changelog