plone.subrequest 1.6

Subrequests for Zope2

Overview

plone.subrequest provides a mechanism for issuing subrequests under Zope2.

Installation

Plone 4

An entry point is provided so no special installation is required past adding plone.subrequest to your instance’s eggs.

Zope 2.12 without Plone

Load this package’s ZCML in the usual manner.

Zope 2.10

You must install ZPublisherEventsBackport to use this package with Zope 2.10 and load both package’s ZCML. The tests require Zope 2.12 / Python 2.6 so will not run.

Usage

Basic usage

Call subrequest(url), it returns a response object.

>>> from plone.subrequest import subrequest
>>> response = subrequest('/folder1/@@url')
>>> response.getBody()
'http://nohost/folder1'

response.getBody() also works for code that calls response.write(data).

>>> response = subrequest('/@@response-write')
>>> response.getBody()
'Some data.\nSome more data.\n'

But in this case response.getBody() may only be called once.

>>> response.getBody()
Traceback (most recent call last):
    ...
ValueError: I/O operation on closed file

Accessing the response body as a file

Some code may call response.write(data).

>>> response = subrequest('/@@response-write')

In which case you may access response.stdout as file.

>>> response.stdout.seek(0, 0)
>>> list(response.stdout)
['Some data.\n', 'Some more data.\n']

You can test whether a file was returned using response._wrote.

>>> response._wrote
1

When you’re done, close the file:

>>> response.stdout.close()

Use response.outputBody() to ensure the body may be accessed as a file.

>>> from plone.subrequest import subrequest
>>> response = subrequest('/folder1/@@url')
>>> response._wrote
>>> response.outputBody()
>>> response._wrote
1
>>> response.stdout.seek(0, 0)
>>> list(response.stdout)
['http://nohost/folder1']

Relative paths

Relative paths are resolved relative to the parent request’s location:

>>> request = traverse('/folder1/@@test')
>>> response = subrequest('folder1A/@@url')
>>> response.getBody()
'http://nohost/folder1/folder1A'

This takes account of default view’s url.

>>> request = traverse('/folder1')
>>> request['URL']
'http://nohost/folder1/@@test'
>>> response = subrequest('folder1A/@@url')
>>> response.getBody()
'http://nohost/folder1/folder1A'

Virtual hosting

When virtual hosting is used, absolute paths are traversed from the virtual host root.

>>> request = traverse('/VirtualHostBase/http/example.org:80/folder1/VirtualHostRoot/')
>>> response = subrequest('/folder1A/@@url')
>>> response.getBody()
'http://example.org/folder1A'

Specifying the root

You may also set the root object explicitly

>>> app = layer['app']
>>> response = subrequest('/folder1A/@@url', root=app.folder1)
>>> response.getBody()
'http://nohost/folder1/folder1A'

Error responses

Subrequests may not be found.

>>> response = subrequest('/not-found')
>>> response.status
404

Or might raise an error.

>>> response = subrequest('/@@error')
>>> response.status
500

So check for the expected status.

>>> response = subrequest('/')
>>> response.status == 200
True

Handling subrequests

The parent request is set as PARENT_REQUEST onto subrequests.

Subrequests also provide the plone.subrequest.interfaces.ISubRequest marker interface.

Changelog

1.6 - 2011-06-06

• Ensure url is a string and not unicode. [elro]

1.6b2 - 2011-05-20

• Set PARENT_REQUEST and add ISubRequest interface to subrequests. [elro]

1.6b1 - 2011-02-11

• Handle IStreamIterator. [elro]

• Simplify API so response.getBody() always works. [elro]

1.5 - 2010-11-26

• Merge cookies from subrequest response into parent response. [awello]

1.4 - 2010-11-10

• First processInput, then traverse (fixes #11254) [awello]

1.3 - 2010-08-24

• Fixed bug with virtual hosting and quoted paths. [elro]

1.2 - 2010-08-16

• Restore zope.component site after subrequest. [elro]

1.1 - 2010-08-14

• Virtual hosting, relative url and error response support. [elro]

1.0 - 2010-07-28

• Initial release. [elro]