using special characters in XML ID for font design

[risacher]

While trying to design a new font, I can't change the XML ID to ":" because Inkscape 1.2 considers this an Invalid ID. (Oddly, If I edit an existing font, it seems to have no problem.).

How is this supposed to work? This seems to be true for other special characters as well.

[risacher]

So... I was editing the XML ID with the Object Properties dialog, which disallows special characters, but the XML editor allows them.

[risacher]

I'm closing this since I found the "workaround" to my problem.

[Shriinivas]

Sorry for the delayed reply.
I tried creating a font with : as one of the characters. I was able to assign : as xml ID and also successfully generate font data with Inkscape 1.2. Could you let me know your OS? Which other special characters had problem? Also, great to know you found a workaround, what exactly did you do to make it work? This information will help others facing similar issue.

[risacher]

I'm using MacOS 12.5.1. (Although I might have been using Ubuntu when I first reported the issue.)

If I create a path in my font template, right-click on it and select "object properties", I get a dialog in which if I assign a character that is invalid in an XML id (such as ":") it will change the label of the ID input box to "Id invalid!" and it will not change the ID attribute, and I therefore cannot seem to make a glyph in my font for such a character.

However, if I open the XML Editor (from the Edit menu) and select the path for my glyph, I can edit the 'id' attribute of the svg:path object in the XML Editor pane and set it to be whatever, including ':' or '"'. Afterwards, if I then open the "object properties" dialog for the same path, it will show the ID attribute as the same character that it forbid me to set earlier.

I have not tested extensively what characters cause a problem, but at the minimum it includes ':', '\'' and '"'

[risacher]

I think this is confusing to explain in text, so I made a quick video to show what I meant: https://youtu.be/TXolpG_CChw

[Shriinivas]

Sorry for not getting back to you earlier. Are you still facing the issue?

[risacher]

I just tested this in Inkscape 1.3, and yeah, it still happens, but the workaround I proposed still works okay too.

Fundamentally, I think there's a bit of a conceptual issue in that the inkscape stroke font extension assumes that the id of the path for the glyph will be the character that it represents, and certain characters are generally not allowed in XML ids. But they sorta work anyway, although Inkscape isn't consistent in how it handles them. Specifically, ':' is okay in the XML editor, but not in the object property editor. I suggest that you document the issue and the workaround in the video tutorials, and move on with your life. I made a comment on Tutorial 1 trying to explain the issue and linking to my own video.