plone.app.imaging 1.0b11

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

Introduction

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.

Installation

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:

[buildout]
extends = buildout.cfg

[instance]
eggs += plone.app.imaging
zcml += plone.app.imaging

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

plone.app.imaging 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:condition="thumbnail"
        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" />

Changelog

1.0b11 - 2010-07-01

• Fix issue with creating scales based on Image objects that are storing their data as chained Pdata objects. [davisagli]

• Avoid using the deprecated five:implements directive. [hannosch]

1.0b10 - 2010-05-01

• Use plone i18n domain instead of plone.app.imaging domain for the MessageFactory. This closes http://dev.plone.org/plone/ticket/10478 [vincentfretin]

• Fix dependency on plone.scale to get requirements for the scale storage. [witsch]

• Fix logic bug in url traversal code for image scales. This fixes http://plone.org/products/plone.app.imaging/issues/1 [ramonski, witsch]

• Add support for custom scales for “News Item” content. This refs http://dev.plone.org/plone/ticket/10250 [pelle, witsch]

• Removed dependency declaration for the unused uuid distribution. [hannosch]

• Fix control panel definition so that its icon shows up again. [witsch]

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 http://dev.plone.org/plone/ticket/10159 [huub_bouma, witsch]

1.0b8 - 2010-03-06

• Convert test setup to use collective.testcaselayer. [witsch]

• Add monkey-patch for createScales in order to fix recreation of scales. This refs http://dev.plone.org/plone/ticket/10186 [witsch]

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

• Allow white space within image scale definitions. This fixes http://dev.plone.org/plone/ticket/9207 [amleczko]

1.0b4 - 2009-10-29

• Refactor default scale handler to make it more reusable for the blob-enabled version in plone.app.blob [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 http://plone.org/products/plone.app.blob/issues/19 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]