Convert the TextAreaDiv widget to use template-based rendering as per Django's release notes: https://docs.djangoproject.com/en/2.0/releases/1.11/#template-based-widget-rendering

Signed-off-by: Michael Price <loneviking72@gmail.com>

mayan/apps/appearance/templates/appearance/forms/widgets/textareadiv.html

@@ -0,0 +1,3 @@
+<pre name="{{ widget.name }}"{% include "django/forms/widgets/attrs.html" %}>
+{% if widget.value %}{{ widget.value }}{% endif %}</pre>
+

mayan/apps/common/widgets.py

@@ -109,6 +109,7 @@ class TextAreaDiv(forms.widgets.Widget):
     Class to define a form widget that simulates the behavior of a
     Textarea widget but using a div tag instead
     """
+    template_name = 'appearance/forms/widgets/textareadiv.html'
 
     def __init__(self, attrs=None):
         # The 'rows' and 'cols' attributes are required for HTML correctness.
@@ -117,15 +118,6 @@ class TextAreaDiv(forms.widgets.Widget):
             default_attrs.update(attrs)
         super(TextAreaDiv, self).__init__(default_attrs)
 
-    def render(self, name, value, attrs=None):
-        if value is None:
-            value = ''
-
-        flat_attrs = flatatt(self.build_attrs(attrs, name=name))
-        content = conditional_escape(force_text(value))
-        result = '<pre%s>%s</pre>' % (flat_attrs, content)
-        return mark_safe(result)
-
 
 def two_state_template(state, ok_icon='fa fa-check', fail_icon='fa fa-times'):
     if state: