• Language: en

Source code for django.template.response

from django.http import HttpResponse

from .loader import get_template, select_template


class ContentNotRenderedError(Exception):
    pass


[docs]class SimpleTemplateResponse(HttpResponse): rendering_attrs = ['template_name', 'context_data', '_post_render_callbacks']
[docs] def __init__(self, template, context=None, content_type=None, status=None, charset=None, using=None): # It would seem obvious to call these next two members 'template' and # 'context', but those names are reserved as part of the test Client # API. To avoid the name collision, we use different names. self.template_name = template self.context_data = context self.using = using self._post_render_callbacks = [] # _request stores the current request object in subclasses that know # about requests, like TemplateResponse. It's defined in the base class # to minimize code duplication. # It's called self._request because self.request gets overwritten by # django.test.client.Client. Unlike template_name and context_data, # _request should not be considered part of the public API. self._request = None # content argument doesn't make sense here because it will be replaced # with rendered template so we always pass empty string in order to # prevent errors and provide shorter signature. super().__init__('', content_type, status, charset=charset) # _is_rendered tracks whether the template and context has been baked # into a final response. # Super __init__ doesn't know any better than to set self.content to # the empty string we just gave it, which wrongly sets _is_rendered # True, so we initialize it to False after the call to super __init__. self._is_rendered = False
def __getstate__(self): """ Raise an exception if trying to pickle an unrendered response. Pickle only rendered data, not the data used to construct the response. """ obj_dict = self.__dict__.copy() if not self._is_rendered: raise ContentNotRenderedError('The response content must be ' 'rendered before it can be pickled.') for attr in self.rendering_attrs: if attr in obj_dict: del obj_dict[attr] return obj_dict
[docs] def resolve_template(self, template): """Accept a template object, path-to-template, or list of paths.""" if isinstance(template, (list, tuple)): return select_template(template, using=self.using) elif isinstance(template, str): return get_template(template, using=self.using) else: return template
[docs] def resolve_context(self, context): return context
@property def rendered_content(self): """Return the freshly rendered content for the template and context described by the TemplateResponse. This *does not* set the final content of the response. To set the response content, you must either call render(), or set the content explicitly using the value of this property. """ template = self.resolve_template(self.template_name) context = self.resolve_context(self.context_data) content = template.render(context, self._request) return content
[docs] def add_post_render_callback(self, callback): """Add a new post-rendering callback. If the response has already been rendered, invoke the callback immediately. """ if self._is_rendered: callback(self) else: self._post_render_callbacks.append(callback)
[docs] def render(self): """Render (thereby finalizing) the content of the response. If the content has already been rendered, this is a no-op. Return the baked response instance. """ retval = self if not self._is_rendered: self.content = self.rendered_content for post_callback in self._post_render_callbacks: newretval = post_callback(retval) if newretval is not None: retval = newretval return retval
@property def is_rendered(self): return self._is_rendered def __iter__(self): if not self._is_rendered: raise ContentNotRenderedError( 'The response content must be rendered before it can be iterated over.' ) return super().__iter__() @property def content(self): if not self._is_rendered: raise ContentNotRenderedError( 'The response content must be rendered before it can be accessed.' ) return super().content @content.setter def content(self, value): """Set the content for the response.""" HttpResponse.content.fset(self, value) self._is_rendered = True
[docs]class TemplateResponse(SimpleTemplateResponse): rendering_attrs = SimpleTemplateResponse.rendering_attrs + ['_request']
[docs] def __init__(self, request, template, context=None, content_type=None, status=None, charset=None, using=None): super().__init__(template, context, content_type, status, charset, using) self._request = request
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