Hi, I checked the code last night and I believe this use case should be covered by https://github.com/l0rdn1kk0n/wicket-bootstrap/blob/a64af20bcd65f365dbd487c7480db441fd6b6489/bootstrap-less/src/main/java/de/agilecoders/wicket/less/LessCacheManager.java#L156 It uses Less4j's APIs to get all imported resources recursively and extracts the latest modification time.
Martin Grigorov Wicket Training and Consulting https://twitter.com/mtgrigorov On Wed, May 18, 2016 at 3:17 PM, Lars Törner <lars.tor...@gmail.com> wrote: > Thanks, we'll try this! > > Cheers > Lasse > > 2016-05-18 13:21 GMT+02:00 Bas Gooren <b...@iswd.nl>: > > > Hi all, > > > > We’ve encountered this issue, too; Simple fix is to touch the less file, > > even when a secondary file was the only change. > > > > The root cause is simple: wicket is not aware of any includes in the less > > file, and as such only looks at the “parent” less file to see if it was > > changed. A potential way to fix this is to make it more intelligent, > > assuming the less compiler can expose such details (referenced files, > > last-modified time of those files). > > > > Met vriendelijke groet, > > Kind regards, > > > > Bas Gooren > > > > Op 18 mei 2016 bij 13:06:59, Martin Grigorov (mgrigo...@apache.org) > > schreef: > > > > Hi Lasse, > > > > I'll take a look in the coming days! > > > > Martin Grigorov > > Wicket Training and Consulting > > https://twitter.com/mtgrigorov > > > > On Wed, May 18, 2016 at 11:43 AM, Lars Törner <lars.tor...@gmail.com> > > wrote: > > > > > Hi Martin! > > > > > > We have now implemented this solution and we're using bootstrap-less - > > > thanks for that! > > > > > > But we have a little problem... > > > The browser does not recognize when the css has changed, the cause > seems > > to > > > be that the newly generated css is placed in a file with the same name > as > > > before. The name has a hashsum in the name that is generated from the > > > less-file and the less file has not changed. > > > > > > What happens is: > > > A less-variable (put in a separate file) gets a new value. > > > This triggers the less compiler to re-generate css > > > The name of the file with generated css has the same name as before so > > the > > > browser decides to use its cached version instead. > > > > > > (I'm not the developer of this issue, but hopefully I got it right...) > > > > > > Any suggestions? > > > > > > Cheers > > > Lasse > > > > > > > > > > > > 2016-03-01 13:02 GMT+01:00 Lars Törner <lars.tor...@gmail.com>: > > > > > > > Thanks for your quick answer Martin! We will look into your > suggestions > > > > and get back to you if we have more questions! > > > > > > > > 2016-03-01 11:49 GMT+01:00 Martin Grigorov <mgrigo...@apache.org>: > > > > > > > >> Hi Lasse, > > > >> > > > >> I think the easiest would be to save the generated CSS in memory, > e.g. > > > in > > > >> YourApplication. > > > >> Once you receive an update from the other system you should just > > delete > > > >> the > > > >> cache (entry). I guess you will have to use read lock when serving > the > > > >> response and write lock when updating it. > > > >> Wicket uses AbstractResource#dataNeedsToBeWritten() > > > >> < > > > >> > > > > > > https://github.com/apache/wicket/blob/ffa34c6bfbd2ccd8340e23ff1601edd3e0e941d6/wicket-core/src/main/java/org/apache/wicket/request/resource/AbstractResource.java#L433 > > > >> > > > > >> method to decide whether the client/browser has the latest version. > > I.e. > > > >> when the browser makes a request for the CSS you should first check > > > >> whether > > > >> there is a cached entry for this CSS file. If there is no such then > > > >> generate it, save it in the cache and serve it back. If there is > such > > > >> cache > > > >> entry then let Wicket check its last modification time against the > > > request > > > >> header value for 'If-Modified-Since'. > > > >> > > > >> Additionally you may want to pre-build the CSS resources at > > application > > > >> start time, or even preserve the current build-time solution, so it > is > > > >> faster for the first users of the application before any changes in > > the > > > >> variables. > > > >> I've had an issue with similar setup in the past - we were using CDN > > > >> (Akamai) and their request timed out while waiting for the Less > > > >> compilation. For requests from normal browsers this shouldn't be a > > > problem > > > >> though. > > > >> > > > >> You may also check Wicket Bootstrap Less > > > >> < > > > >> > > > > > > https://github.com/l0rdn1kk0n/wicket-bootstrap/tree/master/bootstrap-less > > > >> >. > > > >> It is a module of Wicket-Bootstrap project but could be used without > > the > > > >> other modules. > > > >> It provides most of the features you need. You just need to see how > to > > > >> plug > > > >> the update of the variables. > > > >> > > > >> Martin Grigorov > > > >> Wicket Training and Consulting > > > >> https://twitter.com/mtgrigorov > > > >> > > > >> On Tue, Mar 1, 2016 at 10:45 AM, Lars Törner <lars.tor...@gmail.com > > > > > >> wrote: > > > >> > > > >> > Hi! > > > >> > > > > >> > We would like to be able to set new colors in our gui at runtime, > > i.e. > > > >> > change the theme. > > > >> > We use less on component basis. To day we compile the less files > to > > > css > > > >> at > > > >> > buildtime and these becom packacke resources. > > > >> > > > > >> > Now we would like to change the colors by altering the appropriate > > > >> > less-variables. We want to set the colors (just values as - > > > themeColor = > > > >> > #000000) in our legacy application. Our web app lives in another > > > >> > servletcontainer than the legacy applicaton, so one apporach is to > > > fetch > > > >> > the new colors by REST (for example check for new colors once a > > > minute) > > > >> and > > > >> > get them as json in our wicket-web-app. > > > >> > > > > >> > Now we're thinking of using dynamic resources. i.e. do not compile > > the > > > >> > less-files at build-time, instead generate css-files fom the less > > > files > > > >> > (hooking in a less-preprocessor) per component at runtime when > > > >> requested. > > > >> > > > > >> > We don't want to generate the css-resource and send it to the > client > > > if > > > >> > it's already cached in browser and not updated on server. > > > >> > We don't want to generate the css if it has already been done for > > the > > > >> > component and new colors hasn't been set, i.e once a dynamic > > resource > > > is > > > >> > generated, a cached version should be given as response for all > > > clients > > > >> > that request the component. > > > >> > > > > >> > Now the question is if the right way to do this is by > implementing a > > > >> > dynamic resource by extending AbstractResource and to cache the > css > > > >> (output > > > >> > a css-file on disk?, cache in application?) when once generated? > > > >> > > > > >> > Any drawbacks? Performance issues? Is there a better way to do it? > > > >> > > > > >> > Cheers > > > >> > Lasse > > > >> > > > > >> > > > > > > > > > > > > > >
