Addresses issue #621 (#1181)

* issue#621: html highlighter

* docs for issue#621

* removing windows support for issue#621

Co-authored-by: Tinmarino <tinmarino@gmail.com>

autoload/vimwiki/html.vim

@@ -1879,6 +1879,32 @@ function! s:convert_file(path_html, wikifile) abort
       return ''
     endif
     call vimwiki#path#mkdir(path_html)
+
+    if g:vimwiki_global_vars['listing_hl'] > 0 && has("unix")
+      let i = 0
+      while i < len(html_lines)
+        if html_lines[i] =~ '^<pre .*type=.\+>'
+          let type = split(split(split(html_lines[i], 'type=')[1], '>')[0], '\s\+')[0]
+          let attr = split(split(html_lines[i], '<pre ')[0], '>')[0]
+          let start = i + 1
+          let cur = start
+
+          while html_lines[cur] !~ '^<\/pre>'
+            let cur += 1
+          endwhile
+
+          let tmp = ('tmp'. split(system('mktemp -p . --suffix=.' . type, 'silent'), 'tmp')[-1])[:-2]
+          call system('echo ' . shellescape(join(html_lines[start:cur - 1], '\n')) . ' > ' . tmp)
+          call system(g:vimwiki_global_vars['listing_hl_command'] . ' ' . tmp  . ' > ' . tmp . '.html')
+          let html_out = system('cat ' . tmp . '.html')
+          call system('rm ' . tmp . ' ' . tmp . '.html')
+          let i = cur
+          let html_lines = html_lines[0:start - 1] + split(html_out, '\n') + html_lines[cur:]
+        endif
+        let i += 1
+      endwhile
+    endif
+
     call writefile(html_lines, path_html.htmlfile)
     return path_html . htmlfile
   endif

autoload/vimwiki/vars.vim

@@ -167,6 +167,8 @@ function! s:get_default_global() abort
         \   }},
         \ 'links_header': {'type': type(''), 'default': 'Generated Links', 'min_length': 1},
         \ 'links_header_level': {'type': type(0), 'default': 1, 'min': 1, 'max': 6},
+        \ 'listing_hl': {'type': type(0), 'default': 0, 'min': 0, 'max': 1},
+        \ 'listing_hl_command': {'type': type(''), 'default': 'pygmentize -f html'},
         \ 'listsyms': {'type': type(''), 'default': ' .oOX', 'min_length': 2},
         \ 'listsym_rejected': {'type': type(''), 'default': '-', 'length': 1},
         \ 'map_prefix': {'type': type(''), 'default': '<Leader>w'},

doc/vimwiki.txt

@@ -3572,6 +3572,40 @@ The header level of generated links. Valid values are from 1 to 6.
 The default is 1.
 
 
+------------------------------------------------------------------------------
+*g:vimwiki_listing_hl*
+
+When set to 1, enables syntax highlighting in resulting HTML. Whenever a code
+block is encountered the *g:vimwiki_listing_hl_command* is invoked on the
+code block.
+
+
+Value           Description~
+0               Do not highlight code blocks in HTML.
+1               Highlight code blocks in HTML. see *g:vimwiki_listing_hl_command*
+
+Default: 0
+
+
+------------------------------------------------------------------------------
+*g:vimwiki_listing_hl_command*
+
+A string specifying the command for highlighting code blocks in html. The
+argument is going to be a file with an extension specified by a
+type=extension. For example, a python listing would be written like s: >
+  {{{type=py
+  print("hello world")
+  }}}
+The argument in this case is going to be a `foo.py`. The result of the
+highlighting command is going to be enclosed in pre tags with the `type`
+attribute. >
+  <pre type=py>
+  %output of highlight command&
+  </pre>
+
+The default is 'pygmentize -f html'.
+
+
 ------------------------------------------------------------------------------
 *g:vimwiki_tags_header*
 
@@ -3924,6 +3958,7 @@ Contributors and their Github usernames in roughly chronological order:
     - Vinny Furia (@vinnyfuria)
     - paperbenni (@paperbenni)
     - Lily Foster (@lilyinstarlight)
+    - Youssof Taha (@ysftaha)
     - Thomas Leyh (@leyhline)
 
 ==============================================================================
@@ -3936,6 +3971,7 @@ http://code.google.com/p/vimwiki/issues/list. They may be accessible from
 https://github.com/vimwiki-backup/vimwiki/issues.
 
 New:~
+    * Issue #621: Feature request: Highlight code listings in HTML
     * Issue #290: Calendar plugin, do not sign if no wiki
     * Issue #281: Permit `\|` in tables
     * PR #1128: VimwikiGoto: Support wiki pages with spaces