add new example to the format_html page

mattmakai · mattmakai · commit 40b797404c42 · 2019-07-21T12:04:00.000-04:00
diff --git a/content/pages/examples/django/django-utils-html-format-html.markdown b/content/pages/examples/django/django-utils-html-format-html.markdown
@@ -158,3 +158,97 @@ def djng_locale_script(context, default_language='en'):
         language = default_language
 ~~    return format_html('angular-locale_{}.js', language.lower())
 ```
+
+
+## Example 2 from django-auditlog
+[Auditlog](https://github.com/jjkester/django-auditlog) 
+([project documentation](https://django-auditlog.readthedocs.io/en/latest/))
+is a [Django](/django.html) app that logs changes to Python objects,
+similar to the Django admin's logs but with more details and
+output formats.
+
+[**django-auditlog / src / auditlog / mixins.py**](https://github.com/jjkester/django-auditlog/blob/master/src/auditlog/mixins.py)
+
+```python
+import json
+
+from django.conf import settings
+try:
+    from django.core import urlresolvers
+except ImportError:
+    from django import urls as urlresolvers
+try:
+    from django.urls.exceptions import NoReverseMatch
+except ImportError:
+    from django.core.urlresolvers import NoReverseMatch
+~~from django.utils.html import format_html
+from django.utils.safestring import mark_safe
+
+MAX = 75
+
+
+class LogEntryAdminMixin(object):
+
+    def created(self, obj):
+        return obj.timestamp.strftime('%Y-%m-%d %H:%M:%S')
+    created.short_description = 'Created'
+
+    def user_url(self, obj):
+        if obj.actor:
+            app_label, model = settings.AUTH_USER_MODEL.split('.')
+            viewname = 'admin:%s_%s_change' % (app_label, 
+                                               model.lower())
+            try:
+                link = urlresolvers.reverse(viewname, 
+                                            args=[obj.actor.id])
+            except NoReverseMatch:
+                return u'%s' % (obj.actor)
+~~            return format_html(u'<a href="{}">{}</a>', 
+~~                               link, obj.actor)
+
+        return 'system'
+    user_url.short_description = 'User'
+
+    def resource_url(self, obj):
+        app_label, model = obj.content_type.app_label, 
+                           obj.content_type.model
+        viewname = 'admin:%s_%s_change' % (app_label, model)
+        try:
+            args = [obj.object_pk] if obj.object_id is \
+                   None else [obj.object_id]
+            link = urlresolvers.reverse(viewname, args=args)
+        except NoReverseMatch:
+            return obj.object_repr
+        else:
+~~            return format_html(u'<a href="{}">{}</a>', 
+~~                               link, obj.object_repr)
+    resource_url.short_description = 'Resource'
+
+    def msg_short(self, obj):
+        if obj.action == 2:
+            return ''  # delete
+        changes = json.loads(obj.changes)
+        s = '' if len(changes) == 1 else 's'
+        fields = ', '.join(changes.keys())
+        if len(fields) > MAX:
+            i = fields.rfind(' ', 0, MAX)
+            fields = fields[:i] + ' ..'
+        return '%d change%s: %s' % (len(changes), s, fields)
+    msg_short.short_description = 'Changes'
+
+    def msg(self, obj):
+        if obj.action == 2:
+            return ''  # delete
+        changes = json.loads(obj.changes)
+        msg = '<table><tr><th>#</th><th>Field</th>' + \
+              '<th>From</th><th>To</th></tr>'
+        for i, field in enumerate(sorted(changes), 1):
+            value = [i, field] + (['***', '***'] if field == \
+                    'password' else changes[field])
+~~            msg += format_html('<tr><td>{}</td><td>{}</td><td>' + \
+~~                               '{}</td><td>{}</td></tr>', *value)
+
+        msg += '</table>'
+        return mark_safe(msg)
+    msg.short_description = 'Changes'
+```
