vimrc - How does vim map keys based on the file extension?

Question

For example, when editing the .cpp file, you want to map <F5> to :call CompileCpp()<CR>.
When compiling the .html file, I want to map <F5> to :call RunHtml()<CR><Spcae>.
Can this be done?

Answer 1

Probably use this

autocmd FileType vim  call RunHtml()

But it is recommended to set makeprg when using autocmd FileType, and then just make directly when using F5. This will display the error message to quickfix
This is the other language I set

augroup make_autocmd
    autocmd Filetype javascript setlocal makeprg=jsl\ -nologo\ -nofilelisting\ -nosummary\ -nocontext\ -conf\ /etc/jsl.conf\ -process\ %
    autocmd FileType json setlocal makeprg=
    autocmd FileType php
                \ setlocal makeprg=php\ -l\ -n\ -d\ html_errors=off\ % |
                \ setlocal errorformat=%m\ in\ %f\ on\ line\ %l
    autocmd BufWritePost * call Make()
    " auto close quickfix if it is the last window
    autocmd WinEnter * if winnr('$') == 1 && getbufvar(winbufnr(winnr()), "&buftype") == "quickfix" | quit | endif
augroup END

function! Make()
    if &modified | silent write | endif
    if &makeprg == 'make' | return | endif
    let regname = '"~'
    let old_pos = getpos('.')
    silent make
    execute 'cw'
    if !has('gui_running') | redraw! | end
    call setpos('.', old_pos)
endfunction