[MonoDevelop] Ideas for enforcing an XML schema? (syntax highlighting)

[Michael Hutchinson]

On 10 April 2012 17:36, Joshua Granick <bulkmail at joshuagranick.com> wrote:
> Hi!
>
> I'm working on a custom syntax mode for an XML-based file format.
>
> It would be great to be able to highlight when you've used valid nodes and
> attributes. The normal XML syntax mode will highlight any node name or
> attribute, but I'd like to be more specific.
>
> In the original, it looks like this:
>
>        <Span color = "text.markup" rule = "InTag">
>                <Begin><</Begin>
>                <End>></End>
>        </Span>
>
>        <Rule name = "InTag">
>                <Span color = "string" rule="InLiteral">
>                        <Begin>"</Begin>
>                        <Exit><</Exit>
>                        <End>"</End>
>                </Span>
>
>                <Span color = "string" rule="InLiteral">
>                        <Begin>'</Begin>
>                        <Exit><</Exit>
>                        <End>'</End>
>                </Span>
>
>                <!-- attributes -->
>                <Match color =
> "keyword.type">[A-Za-z0-9_]+(:[A-Za-z0-9_]+)?[\s\n\r]*=</Match>
>        </Rule>
>
>
> I've sort of been able to make it work, but it feels like there must be a
> more elegant way to handle it?
>
>
>        <Span color="text.markup" rule="InMetaNode">
>                <Begin><meta</Begin>
>                <End>></End>
>        </Span>
>        <Rule name="InMetaNode">
>                <Span color = "string" rule="InLiteral">
>                        <Begin>"</Begin>
>                        <Exit><</Exit>
>                        <End>"</End>
>                </Span>
>                <Span color = "string" rule="InLiteral">
>                        <Begin>'</Begin>
>                        <Exit><</Exit>
>                        <End>'</End>
>                </Span>
>                <Keywords color="keyword.type">
>                        <Word>if</Word>
>                        <Word>unless</Word>
>                        <Word>title</Word>
>                        <Word>description</Word>
>                        <Word>package</Word>
>                        <Word>version</Word>
>                        <Word>company</Word>
>                </Keywords>
>        </Rule>
>
>
> The problem is that the string rules are duplicated across every single
> custom node I define. I'm also not able to use a nice "Oops! Wrong attribute
> or node name!" color (like black plain text) because invalid attributes and
> node names currently have the same color as (in this case) the "<meta" and
> "=" throughout the tag.
>
> Is it possible to stack rules, or using the standard "InTag" rule, is there
> any way to check for the first keyword, then to allow separate sets of
> keywords from that point on inside the node?

I'm not very familiar with this, but it might be better to have a
"semantic syntax mode" like C# does, which could perform more advanced
highlighting based on a schema.

Or alternatively, how about extending the existing XML background
parser - which generates underlines for syntax errors - to use the
code completion schema to underline invalid elements/attributes?

-- 
Michael Hutchinson
http://mjhutchinson.com