[ http://issues.apache.org/jira/browse/MODPYTHON-97?page=all ] Graham Dumpleton closed MODPYTHON-97: -------------------------------------
> mod_python.publisher iterables and content_type broken > ------------------------------------------------------ > > Key: MODPYTHON-97 > URL: http://issues.apache.org/jira/browse/MODPYTHON-97 > Project: mod_python > Type: Bug > Components: publisher > Versions: 3.2.7 > Reporter: Graham Dumpleton > Assignee: Nicolas Lehuen > Fix For: 3.2.7 > > In 3.2, mod_python.publisher was modified so that if it encountered an > interable it would recursively iterate over the items and publish each with > the result being concatenated. > FWIW, I personally didn't like this as I saw it potentially changing the > behaviour of existing code, although perhaps in contrived cases or for test > code only. I saw that this sort of behaviour should have been managed by the > user by explicit use of a wrapper class instead, rather than it being magic. > End of ramble. :-) > Regardless of my concerns, the behaviour that was added is broken. > Specifically, mod_python.publisher is setting the content type based on the > content of the first item returned from the iterable. For example, consider > the following: > index = [ > '<html><body><p>', > 1000 * "X", > '</p></body></html>', > ] > When published, this is resulting in the content type being set to > 'text/plain' and not 'text/html'. In part this is perhaps caused by the fact > that the content type check is now performed by looking for a trailing > '</html>' in the content whereas previously it would look for a leading > '<html>'. This was changed because all the HTML prologue that can appear > before '<html>' would often throw out this check with the HTML not being > automatically being detected. Thus at the time it was thought that looking > for the trailing '</html>' would be more reliable. It ain't going to help to > go back to using a leading '<html>' check though as the first item may only > contain the prologue and not '<html>'. > These checks are only going to work for iterables if the results of > publishing of each item were added to the end of a list of strings, rather > than being written back immediately using req.write(). Once all that has been > returned by the iterable is obtained, this can all be joined back together > and then the HTML check done. > Joining all the separate items returned from the iterable back together > defeats the purpose of what this feature was about in the first place and may > result in huge in memory objects needing to be created to hold the combined > result just so the HTML check can be done. > The only way to avoid the problem is for the content type to be set > explicitly by the user before the iterable is processed. This is a bit tricky > as it is mod_python.publisher which is automagically doing this. The best you > can do is something like: > class SetContentType: > def __init__(self,content_type): > self.__content_type = content_type > def __call__(self,req): > req.content_type = self.__content_type > return "" > index = [ > SetContentType('text/html'), > '<html><body><p>', > 1000 * "X", > '</p></body></html>', > ] > Once you start doing this, the user may as well have provided their own > published function in the first place that set the content type and manually > iterated over items and wrote them to req.write(). This could also be managed > by a user specified wrapper class which is how I saw this as preferably being > done in the first place. Ie., > class PublishIterable: > def __init__(self,value,content_type): > self.__value = value > self.__content_type = content_type > def __call__(self,req): > req.content_type = self.__content_type > for item in self.__value: > req.write(item) > _values = [ > '<html><body><p>', > 1000 * "X", > '</p></body></html>', > ] > index = PublishIterable(_values,'text/html') > Personally I believe this automagic publishing of iterables should be removed > from mod_python.publisher. You might still provide a special function/wrapper > that works like PublisherIterable but handles recursive structures and > callable objects in the process, but I feel it should be up to the user to > make a conscious effort to use it and mod_python.publisher shouldn't assume > that it should process any iterable in this way automatically. -- This message is automatically generated by JIRA. - If you think it was sent incorrectly contact one of the administrators: http://issues.apache.org/jira/secure/Administrators.jspa - For more information on JIRA, see: http://www.atlassian.com/software/jira
