Open selection in different major mode.

Question

Is it possible to select some parts of a text and open it in a different buffer with a different mode?

Fore example, if I often work in ESS mode (syntax highlighting for R),

astring <- '<form>
<input type="checkbox" id="foo", value="bar">
</form>'

if the text within the single quotes is selected, I would like to edit it in a new buffer HTML mode (similar to org-src-lang-modes in orgmode).

Answer 1

What you're describing is called an 'indirect buffer'. You create one by calling M-x clone-indirect-buffer. This creates a second copy of the buffer you're editing. Any changes made in one buffer are mirrored in the other. However, both buffers can have different major modes active, so one can be in ESS mode, and the other in HTML (or whatever you like).

See the manual for details.