FXP Rewrite

[KaiVolland]

This replaces xml2js parser with fast-xml-parser.

Parsing of functions and expressions is not yet supported.

[rdewit]

@KaiVolland , since you are rewriting the SLD parser, would it make sense to extract the SLD version from the XML if a user has not provided the value explicitly?

The reason that I'm asking is because when we use the SLD parser in our code, we now 'manually' extract it with using the following (also using fast-xml-parser) just to get that version information:

const parserOptions = {
  attributeNamePrefix: '',
  ignoreAttributes: false,
  removeNSPrefix: true
}
const xmlParser = new XMLParser(parserOptions) // fast-xml-parser
const sldObject = xmlParser.parse(responseText) // the SLD coming from an XHR request
const sldVersion = sldObject?.StyledLayerDescriptor?.version

We then feed that version value as option in the constructor of the SLD parser. It seems that automatically extracting it from the SLD would be a logical next step.

If this added functionality does not fit within this PR, I'll happily wait for your work here to be completed and I can then propose that functionality in a separate PR.

[jansule]

since you are rewriting the SLD parser, would it make sense to extract the SLD version from the XML if a user has not provided the value explicitly?

+1 from my side. Personally, I would prefer to have it in a separate PR though.

[marcjansen]

Can you please change the commit message of 385ca38?

[KaiVolland]

Can you please change the commit message of 385ca38?

I'm going to squash this PR so the message will be gone.

[marcjansen]

Not a thorough review, some remarks. Take what you agree with. Thanks.

[dnlkoch]

Very nice @KaiVolland!

[jansule]

Way too much to properly review. Anyhow, made a few remarks.

Is there a reason that parsing Expressions is not included in this PR?

[KaiVolland]

Way too much to properly review. Anyhow, made a few remarks.

Is there a reason that parsing Expressions is not included in this PR?

I wanted to keep this PR only for the rewrite.

The Expression parsing will be completly diffrent then the one before as the geostyler-style v6 and v7 changed a lot there. But there is already an issue for this: #697

[jansule]

Thanks for addressing the remarks! Nice work @KaiVolland

Just a few minor points left

[jansule]

That's unfortunate. But doesn't above line work anyways? It's the same as writing any except that with this notation, we highlight that the output type equals the input type.