Question

I’m using TinyMCE to let users edit and format text, output is html code.
The html is then sent to the server and is pushed to other clients that can follow the edit progress on a webpage, the html is inserted into a div so users can see the format but they are not able to edit.

Now I want the cursor position and any selection the user makes in the editor to show up on the readonly page using highlight(background color) if selected or inserting an empty span with a black border between characters to imitate the cursor position.

I made an attempt using
editor.tinymce().selection.getRng()
which gives me the start and end position of what the user sees(formatting characters are not counted)
Then I traversed the DOM and counted the characters in every text element wrapping the ones selected with a highlight span. This resulted in messy code but worked pretty well until I hit a non ascii or encoded character in the textblock.

Example html

<p>abc&nbsp;<b>de</b>fg</p>

looks like this to the user

abc defg

Say user selected character c to d (selection covers c, a blank, first half of the bold tag and d),
tinymce will return range start:2 end:5
but the actual characters behind would be start:5 end:16.
Just wrapping the text from char 5 to 16 in a highlight span will result in bad html.
Checking for words starting with & and ending with ; and adding number of positions will turn into a mess. There has to be a simpler way

How do I calculate how many “visible” characters a set of html character will turn into?

Or maybe you would attack the problem in another way

Thanks

PS 1
I’ve looked into the various jquery highlight plugins but they seem to highlight based on a search string. Those does not work in the case user selects one character and that character exists several times, they will then highlight all occurences.

Answer 1

I’ve tackled this problem in my Rangy library: the TextRange module concerns itself with the text the user sees. It sounds like you need the selectCharacters() and toCharacterRange() methods of Rangy’s Range objects.