3.10.19. Web Server Classes

Most of the source in master/buildbot/www is self-explanatory. However, a few classes and methods deserve some special mention.

3.10.19.1. Resources

class buildbot.www.resource.Redirect(url): This is a subclass of Twisted Web’s Error. If this is raised within asyncRenderHelper, the user will be redirected to the given URL.

class buildbot.www.resource.Resource

This class specializes the usual Twisted Web Resource class.

It adds support for resources getting notified when the master is reconfigured.

needsReconfig: If True, reconfigResource will be called on reconfig.

reconfigResource(new_config)

Parameters:: new_config – new MasterConfig instance
Returns:: Deferred if desired

Reconfigure this resource.

It’s surprisingly difficult to render a Twisted Web resource asynchronously. This next method makes it quite a bit easier.

asyncRenderHelper(request, callable, writeError=None)

Parameters:

request – the request instance
callable – the render function
writeError – optional callable for rendering errors

This method will call callable, which can return a Deferred, with the given request. The value returned from this callable will be converted to an HTTP response. Exceptions, including Error subclasses, are handled properly. If the callable raises Redirect, the response will be a suitable HTTP 302 redirect.

Use this method as follows:

def render_GET(self, request):
    return self.asyncRenderHelper(request, self.renderThing)