jp (blog/preview): open and preview commands can be changed in sat.conf with "blog_preview_open_cmd" and "blog_preview_update_cmd" in [jp] section + don't convert syntax when content is empty

frontends/src/jp/cmd_blog.py

@@ -101,6 +101,21 @@ class BlogCommon(object):
         # if not found, we use current syntax
         return self.host.bridge.getParamA("Syntax", "Composition", "value", self.profile)
 
+    def parse_args(self, cmd_line, **format_kw):
+        """Parse command arguments
+
+        @param cmd_line(unicode): command line as found in sat.conf
+        @param format_kw: keywords used for formmating
+        @return (list(unicode)): list of arguments to pass to subprocess function
+        """
+        try:
+            # we split the arguments and add the known fields
+            # we split arguments first to avoid escaping issues in file names
+            return [a.format(**format_kw) for a in shlex.split(cmd_line)]
+        except ValueError as e:
+            self.disp(u"Couldn't parse editor cmd [{cmd}]: {reason}".format(cmd=cmd_line, reason=e))
+            return []
+
 
 class Edit(base.CommandBase, BlogCommon):
 
@@ -205,13 +220,7 @@ class Edit(base.CommandBase, BlogCommon):
         except (NoOptionError, NoSectionError):
             # no, we check if we know the editor and have special arguments
             editor_args = EDITOR_ARGS_MAGIC.get(os.path.basename(editor), '')
-        try:
-            # we split the arguments and add the known fields
-            # we split arguments first to avoid escaping issues in file names
-            args = [a.format(content_file=content_file_path, metadata_file=meta_file_path) for a in shlex.split(editor_args)]
-        except ValueError as e:
-            self.disp(u"Couldn't parse editor cmd [{cmd}]: {reason}".format(cmd=editor_args, reason=e))
-            args = []
+        args = self.parse_args(editor_args, content_file=content_file_path, metadata_file=meta_file_path)
         if not args:
             args = [content_file_path]
         editor_exit = subprocess.call([editor] + args)
@@ -303,7 +312,7 @@ class Edit(base.CommandBase, BlogCommon):
                 self.host.quit(1)
 
             content = mb_data['content_xhtml']
-            if current_syntax != 'XHTML':
+            if content and current_syntax != 'XHTML':
                 content = self.host.bridge.syntaxConvert(content, 'XHTML', current_syntax, False, self.profile)
             content_file_obj.write(content.encode('utf-8'))
             content_file_obj.seek(0)
@@ -326,18 +335,32 @@ class Preview(base.CommandBase, BlogCommon):
         url = 'file:{}'.format(self.urllib.quote(self.preview_file_path))
         self.webbrowser.open_new_tab(url)
 
+    def _launchPreviewExt(self, cmd_line, opt_name):
+        url = 'file:{}'.format(self.urllib.quote(self.preview_file_path))
+        args = self.parse_args(cmd_line, url=url, preview_file=self.preview_file_path)
+        if not args:
+            self.disp(u"Couln't find command in \"{name}\", abording".format(name=opt_name), error=True)
+            self.host.quit(1)
+        subprocess.Popen(args)
+
+    def openPreviewExt(self):
+        self._launchPreviewExt(self.open_cb_cmd, "blog_preview_open_cmd")
+
+    def updatePreviewExt(self):
+        self._launchPreviewExt(self.update_cb_cmd, "blog_preview_update_cmd")
+
     def updateContent(self):
-        with open(self.current_file_path, 'rb') as f:
-            content_xhtml = f.read().decode('utf-8')
-            if self.syntax != 'XHTML':
+        with open(self.content_file_path, 'rb') as f:
+            content = f.read().decode('utf-8')
+            if content and self.syntax != 'XHTML':
                 # we use safe=True because we want to have a preview as close as possible to what the
                 # people will see
-                content_xhtml = self.host.bridge.syntaxConvert(content_xhtml, self.syntax, 'XHTML', True, self.profile)
+                content = self.host.bridge.syntaxConvert(content, self.syntax, 'XHTML', True, self.profile)
 
         xhtml = (u'<html xmlns="http://www.w3.org/1999/xhtml">' +
                  u'<head><meta http-equiv="Content-Type" content="text/html;charset=utf-8" /></head>'+
                  '<body>{}</body>' +
-                 u'</html>').format(content_xhtml)
+                 u'</html>').format(content)
 
         with open(self.preview_file_path, 'wb') as f:
             f.write(xhtml.encode('utf-8'))
@@ -370,16 +393,27 @@ class Preview(base.CommandBase, BlogCommon):
         sat_conf = config.parseMainConf()
         SYNTAX_EXT.update(config.getConfig(sat_conf, 'jp', CONF_SYNTAX_EXT, {}))
 
-        open_cb = self.showPreview
-        update_cb = self.showPreview
+        try:
+            self.open_cb_cmd = config.getConfig(sat_conf, 'jp', "blog_preview_open_cmd", Exception)
+        except (NoOptionError, NoSectionError):
+            self.open_cb_cmd = None
+            open_cb = self.showPreview
+        else:
+            open_cb = self.openPreviewExt
+
+        self.update_cb_cmd = config.getConfig(sat_conf, 'jp', "blog_preview_update_cmd", self.open_cb_cmd)
+        if self.update_cb_cmd is None:
+            update_cb = self.showPreview
+        else:
+            update_cb = self.updatePreviewExt
 
         # which file do we need to edit?
         if self.args.file == 'current':
-            self.current_file_path = self.getCurrentFile(sat_conf)
+            self.content_file_path = self.getCurrentFile(sat_conf)
         else:
-            self.current_file_path = os.path.abspath(self.args.file)
+            self.content_file_path = os.path.abspath(self.args.file)
 
-        self.syntax = self.guessSyntaxFromPath(sat_conf, self.current_file_path)
+        self.syntax = self.guessSyntaxFromPath(sat_conf, self.content_file_path)
 
 
         # at this point the syntax is converted, we can display the preview