Convert remaining XHTML documents in platform.doc.isv to HTML

[ptziegler]

Unlike plain HTML, XHTML also follows the XML rules and is therefore more restrictive. By mixing both HTML and XHTML documents, this can very easily lead to a situation where syntax is used that is valid in one, but not the other document.

With this change, all documents within org.eclipse.platform.doc.isv that are still using XHTML are converted to HTML.

[ptziegler]

Follow-up to #3236.

Most of the conversion was done automatically via JSoup. I also validated the changed files using JTidy, which didn't produce any warnings outside the following ones in the ua_cheatsheet_composite.htm.

line 88 column 9 - Warning: <td> attribute "width" has invalid value "10%"
line 92 column 9 - Warning: <td> attribute "width" has invalid value "29%"
line 97 column 9 - Warning: <td> attribute "width" has invalid value "10%"
line 100 column 9 - Warning: <td> attribute "width" has invalid value "29%"
line 109 column 9 - Warning: <td> attribute "width" has invalid value "10%"
line 112 column 9 - Warning: <td> attribute "width" has invalid value "29%"
line 121 column 9 - Warning: <td> attribute "width" has invalid value "10%"
line 124 column 9 - Warning: <td> attribute "width" has invalid value "29%"

I don't think those have anything to do with the XHTML -> HTML conversion, but is simply a warning because tables are used as a layout, which is an anti-pattern.

[merks]

I thought the goal/intent for these really was to be well-formed XHTML. (And I though previously there were checks in place for that.) Maybe some historical knowledge is lost here Also we have a bunch of doc plugins that ought to be consistent so maybe 5 days before the release is not the best time for this...

[ptziegler]

Also we have a bunch of doc plugins that ought to be consistent so maybe 5 days before the release is not the best time for this...

With the latest changes, the documents are displayed correctly again.

I noticed the issue and started cleaning up the files before I forget about this topic. But I didn't intend on merging anything more for the current release.

I thought the goal/intent for these really was to be well-formed XHTML.

My understanding is that XHTML has effectively been superseded by HTML5. Even to a point where it's not guaranteed that they are supported by all browsers. Getting rid of them seems like the cleanest solution.

[akurtakov]

My understanding is that XHTML has effectively been superseded by HTML5. Even to a point where it's not guaranteed that they are supported by all browsers. Getting rid of them seems like the cleanest solution.

That is my current understanding too!

[merks]

My knowledge on this topic is sketchy so I happily defer to those with more of it! 😁

[akurtakov]

As per https://www.w3schools.com/tags/tag_doctype.ASP "DOCTYPE html" is enough so if/when we do changes I would rather see us go that path instead of declaring "transitional"

[ptziegler]

As per https://www.w3schools.com/tags/tag_doctype.ASP "DOCTYPE html" is enough so if/when we do changes I would rather see us go that path instead of declaring "transitional"

That's true. There is no point in not directly migrating to HTML5. In that case I'll also try to get rid of all the remaining warnings reported by the validator.

[ptziegler]

It feels weird only updating some of the documents when all of them should be updated to HTML5, regardless of whether they use XHTML. I'll probably split this PR up into smaller parts, each focusing on a single component. But only after the release.

[akurtakov]

I am closing this one as there are already enough conflicts and some/many of the issues have been taken care in other PRs.