User-configurable, blob-aware image scaling for Plone.

Project Description


This package tries to factor out and re-use the image scaling code from Archetypes into a separate package in order to make it user-configurable and add support for storing the image data into ZODB blobs.


The easiest way to use this package is when working with installations based on zc.buildout. Here you can simply add the package to your "eggs" and "zcml" options, run buildout and restart your Plone instance.

Alternatively you can use the following configuration file to extend an existing buildout:

extends = buildout.cfg

eggs +=
zcml +=

After that you should be able to "quick-install" the package via the "Add-on products" section of Plone's configuration panel ("Site setup").

New-style image scales introduces new ways of using image scales in your templates. There are several variants you can pick from depending on how much flexibility/convenience you need:

  1. for full control you may do the tag generation explicitly:

    <img tal:define="scales context/@@images;
                     thumbnail python: scales.scale('image', width=64, height=64);"
         tal:attributes="src thumbnail/url;
                         width thumbnail/width;
                         height thumbnail/height" />

    This would create an up to 64 by 64 pixel scaled down version of the image stored in the "image" field. It also allows for passing in addition parameters support by plone.scale's scaleImage function, e.g. direction or quality.

  2. for automatic tag generation with extra parameters you would use:

    <img tal:define="scale context/@@images"
         tal:replace="structure python: scale.scale('image',
                      width=1200, height=800, direction='down').tag()" />
  3. for tag generation using predefined scale names this would look like:

    <img tal:define="scale context/@@images"
         tal:replace="structure python: scale.scale('image',
                      scale='mini').tag()" />

    This would use the predefined scale size "mini" to determine the desired image dimensions, but still allow to pass in extra parameters.

  4. a convenience short-cut for option 3 can be used:

    <img tal:replace="structure context/@@images/image/mini" />
  5. and lastly, the short-cut can also be used to render the unscaled image:

    <img tal:replace="structure context/@@images/image" />


1.0b9 - 2010-04-10

  • Add new syntax options for generating image scales based on ideas borrowed from plone.scale, also improving caching and invalidation. [witsch]
  • Provide sizes for plone.namedfile if it's installed. [davisagli]
  • Restore possibility to define per-field image scale sizes. This refs [huub_bouma, witsch]

1.0b8 - 2010-03-06

1.0b7 - 2009-12-03

  • Swallow resizing exceptions if that flag is set on the image field. [matthewwilkes]
  • Add test to make sure traversal to scales in path expressions still works. [davisagli, witsch]

1.0b6 - 2009-11-18

  • Corrected ill-formed msgid that contained a double quote. [hannosch]

1.0b5 - 2009-11-15

1.0b4 - 2009-10-29

  • Refactor default scale handler to make it more reusable for the blob-enabled version in [witsch]

1.0b3 - 2009-08-26

  • Fix compatibility issue with Plone 4.0. [witsch]
  • Revert deferral of monkey-patching and traversal adapter registration to package installation time. [witsch]

1.0b2 - 2009-07-08

  • Register traversal handler locally to avoid problems without the corresponding monkey patch in place. Please see the second issue in for more info. [witsch]
  • Replaced a getUtility with a queryUtility call in getAllowedSizes. [hannosch]

1.0b1 - 2009-05-14

  • Add fallback for determining available image sizes to avoid breaking sites which haven't installed the package yet. [witsch]

1.0a2 - 2008-09-22

  • Fix getAvailableSizes to not depend on sizes field-attribute. [witsch]

1.0a1 - 2008-08-12

  • Initial version [witsch]
  • Initial package structure. [zopeskel]

Current Release

No stable release available yet.

All Releases

Version Released Description Compatibility Licenses Status
1.0b9 More about this release… GPL beta
1.0b8 More about this release… GPL beta
1.0b7 More about this release… GPL beta
1.0b6 More about this release… GPL beta
1.0b5 More about this release… GPL beta
1.0b4 More about this release… GPL beta
1.0 Fix regarding installation issues and support for Plone 4.0. More about this release…
Plone 3
GPL beta