How to add specific string if it is not exists in current file?

Question

I want to add this string "declare(strict_types=1);" after <?php when I save or open a file.

<?php
declare(strict_types=1);

If the file already contains declare(strict_types=1); don't do anything.

Maybe there is a plugin or something? Thank you.

Answer 1

Something like this should work:

function! AddPHPStrictTypes()
    " Save the cursor position
    let cursor_save = getpos('.')

    " Go to the begining of the file
    call cursor(1, 1)

    " Get the line containing "<?php"
    let phpLine = search('<?php')

    " If the declaration isn't in the buffer and there is one line containing "<?php"
    if search('<?php\ndeclare(strict_types=1);') == 0 && phpLine != 0
        " Add the declaration after the line
        call append(phpLine, "declare(strict_types=1);")
    endif

    " Restore cursor position
    call setpos('.', cursor_save)
endfunction


autocmd! BufReadPost *php call AddPHPStrictTypes()

We declare a function which searches for the declaration. If the declaration is not found it search for the line containing <?php and add the declaration after it.

Then we use an autocommand to execute the function each time you open a new php file.

To understand the function better you may want to read

• :h getpos()
• :h setpos()
• :h cursor()
• :h search()
• :h append()

And to change the autocommand:

• :h :autocmd
• :h autocmd-events