UltiSnips: Can I add text outside snippet boundaries? (e.g. Near a search result)

Question

Is there any way that UltiSnips can be made to seek for a text in document and execute some snippet at the position of text?

Explanation of Intent :-

Say I have the following text file

abcde
klsdfl

| %cursor

unique_text

Now, what I want is that if I write trigger and press the expand key (Tab in my case) then the snippet would write some_text and then look for unique_text (which is always unique and located at the bottom of my document), insert two blank lines above it and write anything there and just after some_text position as well?

Bare structure of MWE :-

snippet trigger "you_dont_need_this" wmA
some_text ${1:anything}
#code for seeking unique_text
$1
endsnippet

Expected DryRun :-

abcde
klsdfl

trigger %pressing Tab now

unique_text

Snippet executes.

abcde
klsdfl

some_text anything
          %blank line already existing
anything
          %blank line no 1
          %blank line no 2
unique_text

Edit 1 : Actual usage - I am using snippets for LaTeX documents and wanted to write the bibliography while giving citations immediately. The snippet should go down towards the very end of the document and find \end{thebibliography} and create a \bibitem{cite_key} directly as soon as I expand my snippet for \cite{cite_key} and then I would write the reference (which are often my own thoughts and questions) and then I could use Ctrl-O key-binding from my text editor Vim to jump to the previous location. This would save me a lot of time, specially with large documents.

Answer 1

global !p
def insert_before_unique(name):
    vim.command('/unique_text')
    snip.expand_anon(name + '\n\n\n')
endglobal

post_jump "if snip.tabstop == 0: insert_before_unique(snip.tabstops[1].current_text)"
snippet trigger "tricky stuff"
$1
endsnippet

This seems to do the trick. Or close to it.

If you type trigger and hit tab you'll be prompted to enter text at the one tabstop. Hit tab again and it will also insert whatever you just entered two lines above the line containing unique_text.

Rather than try to get this exactly right for your (just updated) problem description it'll probably be best for you to do the fine tuning (or request in a comment a specific change you need and I can do it).

You can modify the static text in the snippet part however you want. You can also tweak or add vim.commands if needed. You can put any command-line/ex command in those.