How to properly map pinyin to Chinese text in a sentence?

Question

I am working on displaying Chinese texts like CText does, but I wanted to have a version of each text which displays the pinyin next to it.

My question is, how do you properly represent Chinese "words" in pinyin? For example, Google translate's "internet" to 互联网 and the pinyin as hùliánwǎng (multiple syllables hù lián wǎng which is each character in isolation). Should you have these "multi-syllable" words in pinyin like hùliánwǎng, or should it be written as hù lián wǎng? Does it make any difference?

If you need the multi-syllable words to make it read right, that is going to be hard to do for my project (kind of a tangent note). I will get the Chinese characters (like for the Tao Te Ching) as a single string of characters, and the question is how to automatically splice the string of characters into individual multi-character words. The site Yabla seems to split the "sentences" into the multi-word parts, but (a) I don't know how accurate that automatic conversion is, and (b) it is not free / open source (I would like the ability to do this for free). This second bit is kind of a tangent to the main question about how to represent words in pinyin, but if you know how I can convert sentences into pinyin automatically, please leave a comment.

This is what I'm currently doing (no multi-syllable words):

Answer 1

If your pinyin has tone symbols like yours: hùliánwǎng, putting them together(hùliánwǎng) or separately (hù lián wǎng) has no difference. Because every tone symbol represents a character. However, if you put symbols without tone symbols, such as hulianwang vs hu lian wang, only the separated version is better, because putting them together may be ambiguous. for example: xian can be 仙 or 西安。