feat: add vimtex#cite#get_entry api function

refer: #2946

autoload/vimtex/cite.vim

@@ -4,6 +4,26 @@
 " Email:      karl.yngve@gmail.com
 "
 
+function! vimtex#cite#get_entry(...) abort " {{{1
+  let l:key = a:0 > 0 ? a:1 : vimtex#cite#get_key()
+  if empty(l:key) | return {} | endif
+
+  " Ensure we're at the root directory when locating bib files
+  call vimtex#paths#pushd(b:vimtex.root)
+  let l:entries = []
+  for l:file in vimtex#bib#files()
+    let l:entries += vimtex#parser#bib(
+          \ l:file,
+          \ {'backend': has('nvim') ? 'lua' : 'vim'}
+          \)
+  endfor
+  call vimtex#paths#popd()
+
+  " Return entry with the given key
+  return l:entries->filter({_, x -> x.key ==# l:key})->get(0, {})
+endfunction
+
+" }}}1
 function! vimtex#cite#get_key(...) abort " {{{1
   let l:cmd = a:0 > 0 ? a:1 : vimtex#cmd#get_current()
   if empty(l:cmd)

autoload/vimtex/context/cite.vim

@@ -20,19 +20,7 @@ endfunction
 
 " }}}1
 function! s:handler.get_actions() abort dict " {{{1
-  " Ensure we're at the root directory when locating bib files
-  call vimtex#paths#pushd(b:vimtex.root)
-  let l:entries = []
-  for l:file in vimtex#bib#files()
-    let l:entries += vimtex#parser#bib(
-          \ l:file,
-          \ {'backend': has('nvim') ? 'lua' : 'vim'}
-          \)
-  endfor
-  call vimtex#paths#popd()
-
-  let l:entry = get(
-        \ filter(copy(l:entries), {_, x -> x.key ==# self.selected}), 0, {})
+  let l:entry = vimtex#cite#get_entry(self.selected)
 
   if empty(l:entry)
     call vimtex#log#warning('Cite key not found: ' .. self.selected)

doc/vimtex.txt

@@ -6236,6 +6236,12 @@ users for customization.
 
 Note: This reference is currently a work in progress!
 
+*vimtex#cite#get_entry*
+  Returns a citation entry. It takes an option `key` argument. If a `key` is
+  supplied, then the corresponding bib entry for that key is returned (a
+  |Dict|). Else it returns the entry for the key under the cursor. If no key
+  is found, an empty |Dict| is returned.
+
 *vimtex#cite#get_key*
   Returns the citation key under the cursor. Can be useful e.g. to create
   a function to open a citation in another progrem such as BibDesk or Zotero.