Web UI handling of em and strong

[KariRudjord]

I would like an option that leave out strong i a production and an option that leave out em in production. E.g. under Tekstelementer. Nice to use in cooking books who always have a lot of em and strong that is only related to layout.

[josteinaj]

So two separate options? One to leave out <em> and one to leave out <strong>?

For books that don't have <em>, only <strong>, we currently treat the <strong> tags as if they were <em>. If we use the options to say that we want to leave out <em> but keep <strong>, what should happen for such books? Should we remove the <strong> tags in that case? If not, should they be treated as if they were <em> tags, even though the option to leave out <em> tags are enabled?

[bertfrees]

If we reconsider implementing emphasis in Liblouis instead of XSLT (nlbdev/pipeline-mod-nlb#20), the toggling could be easily implemented in CSS. It's also easily implemented in XSLT of course, but the less XSLT code the better I think.

[josteinaj]

We'd be fine with using liblouis. Controlling it with CSS would be great. I think the issue was the ordering of the open- and close "tags" in braille. <em><strong>…</strong></em> vs <strong><em>…</em></strong> vs <em><strong>…</em></strong> vs <strong><em>…</strong></em>, which could not be controlled in liblouis.

[bertfrees]

Ah yes, indeed, this can not be controlled at the moment.

[KariRudjord]

Two separate options, yes. And if we leave out em in a production, still treat strong as em.

I don't know how much we will use the option, but then we can controle every situation without editing the source file (which can be quite a job).

[bertfrees]

I need a name/description of the options (Norwegian).

[bertfrees]

I have made the text formatting fully configurable in CSS. For now there is no option yet but it's very easy to add. The CSS now looks like this:

/* -------------------------------------------------------------------------- */
/*                Text formatting                                             */
/* -------------------------------------------------------------------------- */

@text-transform strong {
    system: -nlb-indicators;
    open: "⠠⠄";
    close: "⠠⠄";
}

@text-transform em {
    system: -nlb-indicators;
    open: "⠆";
    close: "⠰";
}

@text-transform u {
    system: -nlb-indicators;
    open: "⠸";
    close: "⠸";
}

@text-transform strike {
    system: -nlb-indicators;
    open: "⠐⠂";
    close: "⠐⠂";
}

strong, b {
    text-transform: strong;
    :root:not(:has(em, i)) & {
        text-transform: em;
    }
}

em, i {
    text-transform: em;
}

u {
    text-transform: u;
}

strike, s {
    text-transform: strike;
}

sub {
    text-transform: -louis-emph-4;
}

sup {
    text-transform: -louis-emph-5;
}

As you can see there are now the text-transform values strong, em, u and strike, and they are declared with @text-transform rules. The @text-transform rule is something I was already using for SBS.

The @text-transform rules are interpreted in the block-translate.xsl file.

When we are ready to handle emphasis in Liblouis, we only need a very small modification in the CSS, namely text-transform: strong needs to become text-transform: -louis-emph-1, etc.