Add linter HTMLHint for html files

ale_linters/html/htmlhint.vim

@@ -0,0 +1,48 @@
+" Author: KabbAmine <amine.kabb@gmail.com>
+" Description: HTMLHint for checking html files
+
+if exists('g:loaded_ale_linters_html_htmlhint')
+    finish
+endif
+
+let g:loaded_ale_linters_html_htmlhint = 1
+
+function! ale_linters#html#htmlhint#Handle(buffer, lines) abort
+    " Matches patterns lines like the following:
+    "stdin:7:10: <title></title> must not be empty. [error/title-require]
+
+    let pattern = '^stdin:\(\d\+\):\(\d\+\): \(.\+\)$'
+    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 text = match[3]
+
+        " 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': 'E',
+        \   'nr': -1,
+        \})
+    endfor
+
+    return output
+endfunction
+
+call ALEAddLinter('html', {
+\   'name': 'htmlhint',
+\   'executable': 'htmlhint',
+\   'command': 'htmlhint --format=unix stdin',
+\   'callback': 'ale_linters#html#htmlhint#Handle',
+\})