Improve accessibility and add an high contrast css
Matt Barkau commented
See the upcoming accessibility tune-up:
With regard to accessibility reviewers:
1. I know a few persons who are interested in contributing but they don't know where to start. Can you tell me where they need to sign up (anything else in addition to regular Plone registration?) and what to do next?
With regard to the list of Plone accessibility issues:
2. Yes, most of these issues are still relevant to WCAG 2.0, even though DTD/Schema validation is no longer a requirement, and (AFAIK) "hreflang" and "type" on links are not known to be supported by assistive technologies.
3. There is actually no automatic validator for WCAG 1.0, either. Tools like HERA can only *validate* a small part of WCAG 1.0 (less than 30% last time I checked), but they can help knowledgeable users when *evaluating* web content. Can you explain why the availability of evaluation tools is so important in the context of Plone accessibility? I think I've seen this connection elsewhere but I can't remember the rationale.
This list is based on WCAG 1.0, as AFAIK currently is no automatic validator for WCAG 2.0 (e.g. HERA only supports WCAG 1.0). However, this is not a WCAG summary, but a top 12 errors. WCAG 2.0 redistributes the order and clarify points. Also, some points are added but in think that most of the document tips are still valid for WCAG 2.0.
I agree with point 3 (didn't know) and 4 (I was going to fix it in the doc).
With point 2, I partially disagree, but I think that here is not the place to discuss it.
If you want, tell me your plone username (there are many "Christophe") and I will add you edit permissions to edit the document.
I think that we should elaborate a list of "accessibility reviewers" and a accessibility leader. Every release "accessibility reviewers" commit accessibility bugs. When fixed we could schedule an "accessibility day" where blind users can review the release and add their comments (this would be the real-world sessions proposed by Limi).
I had a look at your list of accessibility errors (I can't access the translation with a normal Plone registration) and I have a few comments and questions:
1. It is based on WCAG 1.0 (1999) but WCAG 2.0 was published in December last year. Do you have plans to update your list?
2. The title attribute on links and images is not useful for keyboard users without a screen reader (e.g. persons with motor impairments), so information that is only available in a title attribute is not available to everyone.
3. The summary attribute for tables is not intended for summaries of the content but for a description of the structure of the table. It is not always needed but is useful for complex tables because screen reader users cannot visually associate data cells with headers.
4. With regard to colour contrast, you can refer to WCAG 2.0, which has a luminosity contrast algorithm. (WCAG 1.0 did not have a contrast algorithm.)
We can also add high contrast images with PIL. This will duplicate the number of PIL cached images but would be quite impressive to generate high contrast images on the fly. Another possibility is to generate inverse-colour images for image links highlighting.
However, I think that the main problem with high contrast CSS and images is caching.
I passed on the message to an accessibility mailing list.
Can you also give an estimate of how much time this requires per week or per month?
AdminAlexander Limi (Admin, Plone) commented
Owning it means:
- Testing for accessibility problems in (preferrably before it is released :) for every release
- Filing bugs when you find a particular accessibility problem, preferrably with code examples on how to change the markup, so even people that don't know much about accessibility can fix it
- Organize real-world sessions where Plone is tested with screen readers, so people can point out the issues when they find them. (This is aspirational, but would be very effective, I think)
You don't really need to be a programmer, but basic knowledge on HTML and CSS is of course useful to write good bug reports.
What does "own[ing] the accessibility parts of Plone" mean exactly? What type of person are you looking for? I know many accessibility experts but no Python programmers. Can we find a way to make these two worlds meet?
I wrote a tutorial with the top 12 common accessibility errors in plone. It is in spanish here:
And we are translating it into plone.org:
Ask me if you want to contribute with the translation. When finished it could be a good starting point for plone accessibility documentation.
AdminAlexander Limi (Admin, Plone) commented
So, I see a lot of excitement and demands here, any volunteers to own the accessibility parts of Plone? I used to do this, but can't anymore, because of time constraints. Let us know. :)
Émilie Burelle commented
WCAG 2.0 compliance would benefit the whole Web!
Plone should comply W3C WCAG2.0 and ATAG1.0 (2.0 coming soon)
With the world population getting dramatically older it is imperative that new technology be introduced with accessibility as a key element.
Denis Boudreau commented
Work ok overall adaptation of WCAG recommendations in Plone to those of WCAG 2.0
See also Plone ticket #9298 which requests support for WAI-ARIA landmarks: https://dev.plone.org/plone/ticket/9298 (login required).