Serialising back to XML

[jaystey]

Hi there,

I'm wondering if you would consider adding functionality such that XmlDocument (and perhaps XmlNode) objects could be serialised back to strings of XML.

Thanks for a great library!

[rgrove]

Thanks! I'm glad you like the library.

I think it would be interesting to write a serializer, but it's probably not something I'm going to have time to tackle soon. If I did, though, I would implement it as a separate library (such as @rgrove/serialize-xml). Thanks for letting me know you'd find that useful.

[jahow]

For anyone interested, serializing an XmlDocument back to a string is actually pretty straightforward. Here is a serializing function which contains a few deliberate formatting choices and ignores some nodes (comments, CDATA...):

export function xmlToString( el: XmlElement | XmlText | XmlComment | XmlDocument, indentationLevel = 0 ) { if (el.constructor.name === 'XmlDocument') return `<?xml version="1.0" encoding="UTF-8"?>${xmlToString(  (el as XmlDocument).children[0]  )}` if (el.constructor.name === 'XmlText') { const text = (el as XmlText).text const isEmpty = text.replace(/^\s+|\s+$/g, '') === '' if (isEmpty) return '' return text } if (el.constructor.name !== 'XmlElement' || !(el instanceof XmlElement)) return `<!-- unknown -->` const padding = ' '.repeat(indentationLevel) const children = Array.isArray(el.children) ? el.children .map((el) => xmlToString(el, indentationLevel + 1)) .filter((el) => el !== '') .map((elString, index, array) => index < array.length - 1 ? elString.replace(/\n\s*$/g, '') : elString ) .join('') : '' const attrs = Object.keys(el.attributes).reduce( (prev, curr) => prev + ` ${curr}="${el.attributes[curr]}"`, '' ) const parentPadding = ' '.repeat(Math.max(0, indentationLevel - 1)) if (children === '') { return ` ${padding}<${el.name}${attrs}/> ${parentPadding}` } return ` ${padding}<${el.name}${attrs}>${children}</${el.name}> ${parentPadding}` }

The function is recursive so you just have to call it on the root XmlDocument to have everything printed out.

[josephjunker]

Hi @jahow , thank you for providing this sample. This is extremely useful. Would you mind specifying whether you are releasing this code under a license (hopefully MIT or CC0)? I'd like to use it inside of a closed-source project but am not comfortable copying this amount of unlicensed code.

[jahow]

hey! since this snippet was shared in the parse-xml repository which is in ISD (same as MIT) I guess it would make sense to consider it identically licensed.

Also thanks a lot for having that respectful approach! 🙏

[josephjunker]

Great, thanks a ton!