Add tidy support for html

README.md

@@ -32,6 +32,7 @@ name. That seems to be the fairest way to arrange this table.
 | D | [dmd](https://dlang.org/dmd-linux.html)^ |
 | Fortran | [gcc](https://gcc.gnu.org/) |
 | Haskell | [ghc](https://www.haskell.org/ghc/)^ |
+| HTML | [tidy](http://www.html-tidy.org/) |
 | JavaScript | [eslint](http://eslint.org/), [jscs](http://jscs.info/), [jshint](http://jshint.com/) |
 | JSON | [jsonlint](http://zaa.ch/jsonlint/) |
 | PHP | [php -l](https://secure.php.net/) |

ale_linters/html/tidy.vim

@@ -0,0 +1,54 @@
+" Author: KabbAmine <amine.kabb@gmail.com>
+" Description: This file adds support for checking HTML code with tidy.
+
+if exists('g:loaded_ale_linters_html_tidy')
+    finish
+endif
+
+let g:loaded_ale_linters_html_tidy = 1
+
+function! ale_linters#html#tidy#Handle(buffer, lines)
+    " Matches patterns lines like the following:
+    " line 7 column 5 - Warning: missing </title> before </head>
+
+    let pattern = '^line \(\d\+\) column \(\d\+\) - \(Warning\|Error\): \(.\+\)$'
+    let output = []
+
+    for line in a:lines
+        let match = matchlist(line, pattern)
+
+        if len(match) == 0
+            continue
+        endif
+
+        let line = match[1] + 0
+        let col = match[2] + 0
+        let type = match[3] ==# 'Error' ? 'E' : 'W'
+        let text = printf('[%s]%s', match[3], match[4])
+
+        " vcol is Needed to indicate that the column is a character.
+        call add(output, {
+        \   'bufnr': a:buffer,
+        \   'lnum': line,
+        \   'vcol': 0,
+        \   'col': col,
+        \   'text': text,
+        \   'type': type,
+        \   'nr': -1,
+        \})
+    endfor
+
+    return output
+endfunction
+
+" User options
+let g:ale_html_tidy_executable = get(g:, 'ale_html_tidy_executable', 'tidy')
+let g:ale_html_tidy_args = get(g:, 'ale_html_tidy_args', '-q -e -language en')
+
+call ALEAddLinter('html', {
+\   'name': g:ale_html_tidy_executable,
+\   'executable': g:ale_html_tidy_executable,
+\   'command': printf('%s %s -', g:ale_html_tidy_executable, g:ale_html_tidy_args),
+\   'output_stream': 'stderr',
+\   'callback': 'ale_linters#html#tidy#Handle',
+\})