Inserting a new text at given cursor position

Question

I am working on customizing the codemirror for my new language mode. As part of this new mode implementation, I am writing a new tool bar where user can select some text and

Answer 1

You want to use the replaceRange function. Even though the name says "replace", it also serves as "insert" depending on the arguments. From the documentation at the time I write this:

Replace the part of the document between from and to with the given string. from and to must be {line, ch} objects. to can be left off to simply insert the string at position from. When origin is given, it will be passed on to "change" events, and its first letter will be used to determine whether this change can be merged with previous history events, in the way described for selection origins.