xml.vim

" Language: xml
" Maintainer:   Johannes Zellner <johannes@zellner.org>
" Last Change:  2017 Jun 13
" Notes:    1) does not indent pure non-xml code (e.g. embedded scripts)
"       2) will be confused by unbalanced tags in comments
"       or CDATA sections.
"       2009-05-26 patch by Nikolai Weibull
" TODO:     implement pre-like tags, see xml_indent_open / xml_indent_close

" Only load this indent file when no other was loaded.
if exists("b:did_indent")
    finish
endif
let b:did_indent = 1
let s:keepcpo= &cpo
set cpo&vim

" [-- local settings (must come before aborting the script) --]
setlocal indentexpr=XmlIndentGet(v:lnum,1)
setlocal indentkeys=o,O,*<Return>,<>>,<<>,/,{,}

if !exists('b:xml_indent_open')
    let b:xml_indent_open = '.\{-}<\a'
    " pre tag, e.g. <address>
    " let b:xml_indent_open = '.\{-}<[/]\@!\(address\)\@!'
endif

if !exists('b:xml_indent_close')
    let b:xml_indent_close = '.\{-}</'
    " end pre tag, e.g. </address>
    " let b:xml_indent_close = '.\{-}</\(address\)\@!'
endif

let &cpo = s:keepcpo
unlet s:keepcpo

" [-- finish, if the function already exists --]
if exists('*XmlIndentGet')
  finish
endif

let s:keepcpo= &cpo
set cpo&vim

fun! <SID>XmlIndentWithPattern(line, pat)
    let s = substitute('x'.a:line, a:pat, "\1", 'g')
    return strlen(substitute(s, "[^\1].*$", '', ''))
endfun

" [-- check if it's xml --]
fun! <SID>XmlIndentSynCheck(lnum)
    if '' != &syntax
    let syn1 = synIDattr(synID(a:lnum, 1, 1), 'name')
    let syn2 = synIDattr(synID(a:lnum, strlen(getline(a:lnum)) - 1, 1), 'name')
    if '' != syn1 && syn1 !~ 'xml' && '' != syn2 && syn2 !~ 'xml'
        " don't indent pure non-xml code
        return 0
    elseif syn1 =~ '^xmlComment' && syn2 =~ '^xmlComment'
        " indent comments specially
        return -1
    endif
    endif
    return 1
endfun

" [-- return the sum of indents of a:lnum --]
fun! <SID>XmlIndentSum(lnum, style, add)
    let line = getline(a:lnum)
    if a:style == match(line, '^\s*</')
    return (shiftwidth() *
    \  (<SID>XmlIndentWithPattern(line, b:xml_indent_open)
    \ - <SID>XmlIndentWithPattern(line, b:xml_indent_close)
    \ - <SID>XmlIndentWithPattern(line, '.\{-}/>'))) + a:add
    else
    return a:add
    endif
endfun

fun! XmlIndentGet(lnum, use_syntax_check)
    " Find a non-empty line above the current line.
    let lnum = prevnonblank(a:lnum - 1)

    " Hit the start of the file, use zero indent.
    if lnum == 0
    return 0
    endif

    if a:use_syntax_check
    let check_lnum = <SID>XmlIndentSynCheck(lnum)
    let check_alnum = <SID>XmlIndentSynCheck(a:lnum)
    if 0 == check_lnum || 0 == check_alnum
        return indent(a:lnum)
    elseif -1 == check_lnum || -1 == check_alnum
        return -1
    endif
    endif

    let ind = <SID>XmlIndentSum(lnum, -1, indent(lnum))
    let ind = <SID>XmlIndentSum(a:lnum, 0, ind)

    return ind
endfun

let &cpo = s:keepcpo
unlet s:keepcpo

" vim:ts=8