3 :class:`Page`\ s are the most frequently used :class:`.View` subclass. They define a basic HTML page and its associated content. Each :class:`Page` renders itself according to a :class:`Template`. The :class:`Template` may contain :ttag:`container` tags, which define related :class:`Contentlet`\ s and :class:`ContentReference`\ s for any page using that :class:`Template`.
7 from django.conf import settings
8 from django.contrib.contenttypes.models import ContentType
9 from django.contrib.contenttypes import generic
10 from django.core.exceptions import ValidationError
11 from django.db import models
12 from django.http import HttpResponse
13 from django.template import Context, RequestContext, Template as DjangoTemplate
15 from philo.models.base import SlugTreeEntity, register_value_model
16 from philo.models.fields import TemplateField
17 from philo.models.nodes import View
18 from philo.signals import page_about_to_render_to_string, page_finished_rendering_to_string
19 from philo.utils import templates
22 __all__ = ('Template', 'Page', 'Contentlet', 'ContentReference')
25 class Template(SlugTreeEntity):
26 """Represents a database-driven django template."""
27 #: The name of the template. Used for organization and debugging.
28 name = models.CharField(max_length=255)
29 #: Can be used to let users know what the template is meant to be used for.
30 documentation = models.TextField(null=True, blank=True)
31 #: Defines the mimetype of the template. This is not validated. Default: ``text/html``.
32 mimetype = models.CharField(max_length=255, default=getattr(settings, 'DEFAULT_CONTENT_TYPE', 'text/html'))
33 #: An insecure :class:`~philo.models.fields.TemplateField` containing the django template code for this template.
34 code = TemplateField(secure=False, verbose_name='django template code')
36 def get_containers(self):
38 Returns a tuple where the first item is a list of names of contentlets referenced by containers, and the second item is a list of tuples of names and contenttypes of contentreferences referenced by containers. This will break if there is a recursive extends or includes in the template code. Due to the use of an empty Context, any extends or include tags with dynamic arguments probably won't work.
41 template = DjangoTemplate(self.code)
42 return templates.get_containers(template)
43 containers = property(get_containers)
45 def __unicode__(self):
46 """Returns the value of the :attr:`name` field."""
49 class Meta(SlugTreeEntity.Meta):
55 Represents a page - something which is rendered according to a :class:`Template`. The page will have a number of related :class:`Contentlet`\ s and :class:`ContentReference`\ s depending on the template selected - but these will appear only after the page has been saved with that template.
58 #: A :class:`ForeignKey` to the :class:`Template` used to render this :class:`Page`.
59 template = models.ForeignKey(Template, related_name='pages')
60 #: The name of this page. Chances are this will be used for organization - i.e. finding the page in a list of pages - rather than for display.
61 title = models.CharField(max_length=255)
63 def get_containers(self):
65 Returns the results :attr:`~Template.containers` for the related template. This is a tuple containing the specs of all :ttag:`container`\ s in the :class:`Template`'s code. The value will be cached on the instance so that multiple accesses will be less expensive.
68 if not hasattr(self, '_containers'):
69 self._containers = self.template.containers
70 return self._containers
71 containers = property(get_containers)
73 def render_to_string(self, request=None, extra_context=None):
75 In addition to rendering as an :class:`HttpResponse`, a :class:`Page` can also render as a string. This means, for example, that :class:`Page`\ s can be used to render emails or other non-HTML content with the same :ttag:`container`-based functionality as is used for HTML.
77 The :class:`Page` will add itself to the context as ``page`` and its :attr:`~.Entity.attributes` as ``attributes``. If a request is provided, then :class:`request.node <.Node>` will also be added to the context as ``node`` and ``attributes`` will be set to the result of calling :meth:`~.View.attributes_with_node` with that :class:`.Node`.
81 context.update(extra_context or {})
82 context.update({'page': self, 'attributes': self.attributes})
83 template = DjangoTemplate(self.template.code)
85 context.update({'node': request.node, 'attributes': self.attributes_with_node(request.node)})
86 page_about_to_render_to_string.send(sender=self, request=request, extra_context=context)
87 string = template.render(RequestContext(request, context))
89 page_about_to_render_to_string.send(sender=self, request=request, extra_context=context)
90 string = template.render(Context(context))
91 page_finished_rendering_to_string.send(sender=self, string=string)
94 def actually_render_to_response(self, request, extra_context=None):
95 """Returns an :class:`HttpResponse` with the content of the :meth:`render_to_string` method and the mimetype set to the :attr:`~Template.mimetype` of the related :class:`Template`."""
96 return HttpResponse(self.render_to_string(request, extra_context), mimetype=self.template.mimetype)
98 def __unicode__(self):
99 """Returns the value of :attr:`title`"""
102 def clean_fields(self, exclude=None):
104 This is an override of the default model clean_fields method. Essentially, in addition to validating the fields, this method validates the :class:`Template` instance that is used to render this :class:`Page`. This is useful for catching template errors before they show up as 500 errors on a live site.
111 super(Page, self).clean_fields(exclude)
112 except ValidationError, e:
113 errors = e.message_dict
117 if 'template' not in errors and 'template' not in exclude:
119 self.template.clean_fields()
120 self.template.clean()
121 except ValidationError, e:
122 errors['template'] = e.messages
125 raise ValidationError(errors)
131 class Contentlet(models.Model):
132 """Represents a piece of content on a page. This content is treated as a secure :class:`~philo.models.fields.TemplateField`."""
133 #: The page which this :class:`Contentlet` is related to.
134 page = models.ForeignKey(Page, related_name='contentlets')
135 #: This represents the name of the container as defined by a :ttag:`container` tag.
136 name = models.CharField(max_length=255, db_index=True)
137 #: A secure :class:`~philo.models.fields.TemplateField` holding the content for this :class:`Contentlet`. Note that actually using this field as a template requires use of the :ttag:`include_string` template tag.
138 content = TemplateField()
140 def __unicode__(self):
141 """Returns the value of the :attr:`name` field."""
148 class ContentReference(models.Model):
149 """Represents a model instance related to a page."""
150 #: The page which this :class:`ContentReference` is related to.
151 page = models.ForeignKey(Page, related_name='contentreferences')
152 #: This represents the name of the container as defined by a :ttag:`container` tag.
153 name = models.CharField(max_length=255, db_index=True)
154 content_type = models.ForeignKey(ContentType, verbose_name='Content type')
155 content_id = models.PositiveIntegerField(verbose_name='Content ID', blank=True, null=True)
156 #: A :class:`GenericForeignKey` to a model instance. The content type of this instance is defined by the :ttag:`container` tag which defines this :class:`ContentReference`.
157 content = generic.GenericForeignKey('content_type', 'content_id')
159 def __unicode__(self):
160 """Returns the value of the :attr:`name` field."""
167 register_value_model(Template)
168 register_value_model(Page)