On Tue, Apr 9, 2013 at 9:57 AM, Barry Books <[email protected]<javascript:_e({}, 'cvml', '[email protected]');> > wrote:
> When I tried to integrate the Amazon CDN with Tapestry the version in the > URL was a constant problem. The other issue is the zipped vs unzipped > assets. Tapestry uses the same URL for both but you can't do that with > Amazons CDN. You need two files. Interesting. That's something that could be addressed, it just never occurred to me that it was a problem. It's a pain though ... it means that anytime we write an Asset URL that *could* be compressed (JavaScript, CSS ... but not images) then we have to decide whether to write the URL for the compressed version or the uncompressed version. In the current implementation, we make that decision based on the request that asks for the asset, and send back the normal or compressed content at that point. > This will also be a problem with caching by ETag since compressed and > uncompressed assets will have different ETags. I think processing the CSS > is likely to also cause CDN problems. > Currently, we use the same ETag for both the compressed and the uncompressed version. I can see that this may be an issue with regards to caching and CDN ... a client may request the uncompressed version and get a GZIP stream unexpectedly. GWT uses the hash in asset urls and it seems to work fine. It also used > nocache in the URL to specify the URL is not cached. This can be useful > under some circumstances. > I can see that as well. > > On Apr 9, 2013, at 11:37 AM, Howard Lewis Ship > <[email protected]<javascript:_e({}, 'cvml', '[email protected]');>> > wrote: > > > In 5.4-alpha-3, Tapestry parsers CSS and converts url() references into > > absolute paths that include the asset checksum. > > > > There may also be the option to inline small assets directly into the > > stylesheet. > > > > > > On Tue, Apr 9, 2013 at 6:26 AM, Barry Books > > <[email protected]<javascript:_e({}, 'cvml', '[email protected]');>> > wrote: > > > >> After being bitten by APPLICATION_VERSION I switched to this > >> > >> configuration.override(SymbolConstants.APPLICATION_VERSION, > >> *new*Date().getTime()); > >> > >> > >> This way on my development machine I get a new version every restart > and on > >> my production machine on every deploy. > >> > >> > >> That said I think the hash of the object in the URL and a never expires > >> header is the way to handle this. The only problem I can think of is > assets > >> in style sheets. I would say the solution to that problem lookup the > asset > >> with the hashed url and return the object with a never expires header. > If > >> there is no hash just return the object without the header. This makes > it > >> easy to use assets in stylesheets. If you want to solve the caching > problem > >> just override (or declare) the style in the Layout component and use the > >> asset like this: > >> > >> > >> <style> > >> > >> .navbar-fixed-top { > >> > >> xheight: 64px; > >> > >> background-position: 0px 40px; > >> > >> xbackground-image: url('${context:/images/top-background.jpg}'); > >> > >> xbackground-repeat: repeat-x; > >> > >> } > >> > >> </style> > > > > > > > > -- > > Howard M. Lewis Ship > > > > Creator of Apache Tapestry > > > > The source for Tapestry training, mentoring and support. Contact me to > > learn how I can get you up and productive in Tapestry fast! > > > > (971) 678-5210 > > http://howardlewisship.com > > --------------------------------------------------------------------- > To unsubscribe, e-mail: [email protected]<javascript:_e({}, > 'cvml', '[email protected]');> > For additional commands, e-mail: > [email protected]<javascript:_e({}, 'cvml', > '[email protected]');> > > -- Howard M. Lewis Ship Creator of Apache Tapestry The source for Tapestry training, mentoring and support. Contact me to learn how I can get you up and productive in Tapestry fast! (971) 678-5210 http://howardlewisship.com -- Howard M. Lewis Ship Creator of Apache Tapestry The source for Tapestry training, mentoring and support. Contact me to learn how I can get you up and productive in Tapestry fast! (971) 678-5210 http://howardlewisship.com
