custom source: get_keyword_pattern vs get_trigger_characters

[vicecaycedo]

I'm working on creating a custom source and I'm confused as to what get_keyword_pattern and get_trigger_characters do.

For context, I'm working on a cmp source that only suggests items when "b/" is typed. Setting the keyword_pattern to ‘b’ and the trigger character to ‘/’ seems to work, but the source:complete function gets called every time ‘b’ is typed. Ideally, this function would only be called when ‘b/’ is typed.

I appreciate the help! Thanks!

[vicecaycedo]

The solution is to have the keyword pattern be 'b/' and omitting the trigger characters. The other important part is that the response item labels have to begin with the keyword pattern, e.g. 'b/' in this case.

[hrsh7th]

You are right.

The trigger character is needed to support the thing like object.| situation.

Typically, the completion engine does not invoke completion with less than 1 keyword characters.
But in the situation of object.|, we might hope to suggest all of the object's methods.

In this case, you should add . as trigger characters.

[nyngwang]

Oh @vicecaycedo really thank you for asking this, I'm building a source too!

[nyngwang]

@hrsh7th:

• What if I want to trigger it on every keystroke, so those items will always appear in the menu?
• What if I don't want to trigger it until I press some keymap like <C-g>?
• I just saw some source has both get_keyword_pattern, get_trigger_characters missing, and it use callback({ isIncomplete = true }) instead. What is that?