added plugin template content injection to primary model detail views

netbox/extras/plugins/__init__.py

@@ -0,0 +1,87 @@
+import collections
+import inspect
+
+from django.core.exceptions import ImproperlyConfigured
+from django.template.loader import get_template
+
+from extras.utils import registry
+from .signals import register_detail_page_content_classes
+
+
+class PluginTemplateContent:
+    """
+    This class is used to register plugin content to be injected into core NetBox templates.
+    It contains methods that are overriden by plugin authors to return template content.
+
+    The `model` attribute on the class defines the which model detail page this class renders
+    content for. It should be set as a string in the form '<app_label>.<model_name>'.
+    """
+    model = None
+
+    def __init__(self, obj):
+        self.obj = obj
+
+    def render(self, template, extra_context=None):
+        """
+        Convenience menthod for rendering the provided template name. The detail page object is automatically
+        passed into the template context as `obj` but an additional context dictionary may be passed as `extra_context`.
+        """
+        context = {'obj': self.obj}
+        if isinstance(extra_context, dict):
+            context.update(extra_context)
+
+        return get_template(template).render(context)
+
+    def left_page(self):
+        """
+        Content that will be rendered on the left of the detail page view. Content should be returned as an
+        HTML string. Note that content does not need to be marked as safe because this is automatically handled.
+        """
+        raise NotImplementedError
+
+    def right_page(self):
+        """
+        Content that will be rendered on the right of the detail page view. Content should be returned as an
+        HTML string. Note that content does not need to be marked as safe because this is automatically handled.
+        """
+        raise NotImplementedError
+
+    def full_width_page(self):
+        """
+        Content that will be rendered within the full width of the detail page view. Content should be returned as an
+        HTML string. Note that content does not need to be marked as safe because this is automatically handled.
+        """
+        raise NotImplementedError
+
+    def buttons(self):
+        """
+        Buttons that will be rendered and added to the existing list of buttons on the detail page view. Content
+        should be returned as an HTML string. Note that content does not need to be marked as safe because this is
+        automatically handled.
+        """
+        raise NotImplementedError
+
+
+def register_content_classes():
+    registry.plugin_template_content_classes = collections.defaultdict(list)
+
+    responses = register_detail_page_content_classes.send('registration_event')
+    for receiver, response in responses:
+        if not isinstance(response, list):
+            response = [response]
+        for template_class in response:
+            if not inspect.isclass(template_class):
+                raise TypeError('Plugin content class {} was passes as an instance!'.format(template_class))
+            if not issubclass(template_class, PluginTemplateContent):
+                raise TypeError('{} is not a subclass of extras.plugins.PluginTemplateContent!'.format(template_class))
+            if template_class.model is None:
+                raise TypeError('Plugin content class {} does not define a valid model!'.format(template_class))
+
+            registry.plugin_template_content_classes[template_class.model].append(template_class)
+
+
+def get_content_classes(model):
+    if not hasattr(registry, 'plugin_template_content_classes'):
+        register_content_classes()
+
+    return registry.plugin_template_content_classes.get(model, [])

netbox/extras/plugins/signals.py

@@ -27,8 +27,8 @@ class PluginSignal(django.dispatch.Signal):
 
 
 """
-This signal collects templates which render buttons for object detail pages
+This signal collects templates which render content for object detail pages
 """
-register_detail_page_buttons = PluginSignal(
+register_detail_page_content_classes = PluginSignal(
     providing_args=[]
 )

netbox/extras/templatetags/plugins.py

@@ -2,26 +2,59 @@ from django import template as template_
 from django.template.loader import get_template
 from django.utils.safestring import mark_safe
 
-from extras.plugins.signals import register_detail_page_buttons
+from extras.plugins import get_content_classes
 
 
 register = template_.Library()
 
 
+def _get_registered_content(obj, method):
+    """
+    Given an object and a PluginTemplateContent method name, return all the registered content for the
+    object's model.
+    """
+    html = ''
+
+    plugin_template_classes = get_content_classes(obj._meta.label_lower)
+    for plugin_template_class in plugin_template_classes:
+        plugin_template_renderer = plugin_template_class(obj)
+        try:
+            content = getattr(plugin_template_renderer, method)()
+        except NotImplementedError:
+            # This content renderer class does not define content for this method
+            continue
+        html += content
+
+    return mark_safe(html)
+
+
 @register.simple_tag()
 def plugin_buttons(obj):
     """
     Fire signal to collect all buttons registered by plugins
     """
-    html = ''
-    responses = register_detail_page_buttons.send(obj)
-    for receiver, response in responses:
-        if not isinstance(response, list):
-            response = [response]
-        for template in response:
-            if isinstance(template, str):
-                template_text = get_template(template).render({'obj': obj})
-                html += template_text
+    return _get_registered_content(obj, 'buttons')
 
-    return mark_safe(html)
 
+@register.simple_tag()
+def plugin_left_page(obj):
+    """
+    Fire signal to collect all left page content registered by plugins
+    """
+    return _get_registered_content(obj, 'left_page')
+
+
+@register.simple_tag()
+def plugin_right_page(obj):
+    """
+    Fire signal to collect all right page content registered by plugins
+    """
+    return _get_registered_content(obj, 'right_page')
+
+
+@register.simple_tag()
+def plugin_full_width_page(obj):
+    """
+    Fire signal to collect all full width page content registered by plugins
+    """
+    return _get_registered_content(obj, 'full_width_page')