It probably should ... but personally I still believe in equal rights of 404 pages with any other template.
David's solution is great and definitely works. But this thread made me realize that a higher/easier level of addressing this is helpful. >From user perspective saying something like ".. .if a template cannot be found, just use the template denominated by this path (i.e. "foo" :: "bar" :: "404" :: Nil) instead.". Lift then would process this template as the regular one with the difference that it will use 404 status code automatically. Currently I have a prototype implementation and an offline discussion with David about other more internal implications. We'll see where it goes. Br's, Marius On Jan 1, 12:12 am, Alex Black <[email protected]> wrote: > That sounds great. > > Just curious though, is there any chance runTemplate should just do > the head merge? > > On Dec 31, 3:12 pm, David Pollak <[email protected]> > wrote: > > > On Wed, Dec 30, 2009 at 7:43 PM, Alex Black <[email protected]> wrote: > > > Ok, I tried this, it gets closer. > > > > I noticed one issue: the head merge didn't get done, so I have two > > > <head> tags in the result. I'm attempting to set the title in the > > > 404.html template, maybe there is a way I can set the title without > > > using head merge? > > > I'm opening up the merge method, so once the code is in master, you'll be > > able to do: > > > def generate404(): LiftResponse = { > > import scala.xml.Node > > > val resp: Box[Node] = S.setVars("expandAll" -> "true") { > > for { > > session <- S.session > > req <- S.request > > rendered <- S.runTemplate("404" :: Nil) > > } yield session.performHeadMerge(rendered, req) > > } > > > XhtmlResponse(resp openOr <html><body>Got a 404</body></html>, > > Empty, List("Content-Type" -> "text/html; charset=utf-8"), > > > Nil, 404, S.ieMode) > > } > > > This will do the head merge and give you the ability to do anything Lift > > does. > > > > - Alex > > > > On Dec 30, 2:54 pm, David Pollak <[email protected]> > > > wrote: > > > > In Boot.scala (the boot method): > > > > > LiftRules.passNotFoundToChain = false > > > > > LiftRules.uriNotFound.prepend { > > > > case _ => generate404() > > > > } > > > > > In the Boot class: > > > > > def generate404(): LiftResponse = { > > > > import scala.xml.Node > > > > > val resp: Box[Node] = S.setVars("expandAll" -> "true") { > > > > for { > > > > rendered <- S.runTemplate("404" :: Nil) > > > > } yield rendered(0) > > > > } > > > > > XhtmlResponse(resp openOr <html><body>Got a 404</body></html>, > > > > Empty, List("Content-Type" -> "text/html; > > > charset=utf-8"), > > > > Nil, 404, S.ieMode) > > > > } > > > > > And a 404.html file (which can be localized): > > > > > <lift:surround with="default" at="content"> > > > > Couldn't find your page... sorry > > > > </lift:surround> > > > > > The uriNotFound code is executed within the S scope, so you've got all > > > the > > > > goodness of knowing who the current user is, etc. > > > > > The reason that the menu was not being rendered in your example is that > > > menu > > > > rendering is based on the location property in the Req(uest). If there > > > is > > > > no location (as defined in the SiteMap), then no menu can be rendered. > > > > There's an option for displaying the entire sitemap by setting the > > > > expandAll="true" attribute when invoking the Menu.builder snippet. But > > > you > > > > don't really want to show the entire menu on all pages, so the > > > > S.setVars("expandAll" -> "true") {...} method (which is a good candidate > > > for > > > > renaming for all you renamers out there) allows us to set the expandAll > > > > attribute for the duration of the code block. > > > > > Then we use S.runTemplate() to locate and run the 404.html template. > > > > > Finally, we create the XhtmlResponse with the 404 error code. > > > > > So, you can put whatever you want in the 404.html template (including > > > > snippets) and all will work as expected. > > > > > Thanks, > > > > > David > > > > > On Wed, Dec 30, 2009 at 10:45 AM, Alex Black <[email protected]> wrote: > > > > > > It's not rewriting. > > > > > > I didn't say it was. I just said it seemed most similar to re-writing. > > > > > > > Trying to mix the two will muddy the concept of rewriting and when > > > > > > it > > > > > > happens. > > > > > > Makes sense. > > > > > > > As far as I can tell, the two problems you are facing are: > > > > > > > 1. There's a non-trivial amount of your code that needs to run to > > > > > render > > > > > > the 404 error page. This would be corrected by the suggestion > > > that I > > > > > posted > > > > > > regarding a LiftRule that generates the default 404 template. > > > > > > 2. Putting navigation on the page. I'm still noodling how to > > > address > > > > > > this particular issue. > > > > > > > If there are issues other than 1 and 2, please enumerate them. > > > > > > Those do sound like the issues. Just to reflect it back to you from > > > > > my perspective (in case one of us is missing something), the issue as > > > > > I see it is that I've designed a nice 404 template using lift features > > > > > (like surround, sitemap, headmerge), and I'd like to display it to the > > > > > user when no handler can be found > > > > > > Whats preventing me from doing this is: the current notfound mechanism > > > > > takes a liftResponse, not a template to render, and as such forces me > > > > > to render the template itself, and although Russ proposed a way to do > > > > > that Marius indicated this could have side effects and feels like the > > > > > wrong approach. > > > > > > > > What about Either[RewriteResponse, LiftResponse]? E.g. same as > > > > > > > what > > > > > > > Marius suggested but use RewriteResponse instead of String. > > > > > > > > On Dec 30, 1:26 pm, Marius <[email protected]> wrote: > > > > > > > > I thought of that but that is problematic because: > > > > > > > > > 1. Having a TemplateResponse holding a path without the > > > > > > > > rendering > > > > > > > > logic, people could use that to send a response to the client, > > > which > > > > > > > > would be incorrect as having a LiftResponse holding /a/b/c > > > doesn;t > > > > > > > > mean anything to a client. And this would alter the semantics of > > > a > > > > > > > > LiftResponse. That's why I proposed an Either. > > > > > > > > > 2. On the other hand if we have a TemplateResponse holding the > > > logic > > > > > > > > of processing a template (similar to the one proposed on this > > > thread) > > > > > > > > would mean that we're doing the processing outside of the normal > > > > > > > > rendering pipeline which has the downsides discussed. > > > > > > > > > Br's, > > > > > > > > Marius > > > > > > > > > On Dec 30, 8:18 pm, Naftoli Gugenheim <[email protected]> > > > wrote: > > > > > > > > > > Would it not be possible to have a LiftResponse that runs > > > through > > > > > the > > > > > > > regular plumbing? This way instead of introducing Either you can > > > just > > > > > use a > > > > > > > TemplateResponse etc. > > > > > > > > > > ------------------------------------- > > > > > > > > > > Marius<[email protected]> wrote: > > > > > > > > > > Please open a defect herehttp://github.com/dpp/liftweb/issues. > > > .. > > > > > > > > > whether or not this solution will make it in master will be > > > subject > > > > > > > > > for reviewboard. The solution I proposed has a breaking change > > > by > > > > > the > > > > > > > > > introduction of Either[List[String], LiftResponse] instead of > > > > > > > > > LiftResponse but I don't think that many people are using > > > > > uriNotFound > > > > > > > > > and it's really quite a small change which regardless needs to > > > be > > > > > > > > > announced. > > > > > > > > > > Other opinions on this? > > > > > > > > > > Br's, > > > > > > > > > Marius > > > > > > > > > > On Dec 30, 6:20 pm, Alex Black <[email protected]> wrote: > > > > > > > > > > > > While I totally agree that a plain 404 + markup is much > > > more > > > > > > > > > > > straightforward, > > > > > > > > > > > "breaks internet" are too big words :) .. sending back a > > > > > > > > > > > 302 or 301 tells the UA "you asked me for a resource that > > > > > > > > > > > I > > > > > know I > > > > > > > > > > > don't have but I wont tell > > > > > > > > > > > you explicitely, instead I want you to go to this location > > > as > > > > > an > > > > > > > > > > > alternative resource". Somehow it's like scratching with > > > the > > > > > wrong > > > > > > > > > > > hand and purely from HTTP protocol perspective this is not > > > > > quite > > > > > > > > > > > straightforward as 404 + template, but I don't necessarily > > > see > > > > > it > > > > > > > as a > > > > > > > > > > > so bad thing. > > > > > > > > > > > Heh, I apologise, definitely "breaking the internet" is a > > > > > > > > > > bit > > > > > > > > > > dramatic. I do have a different view than you though, I > > > think > > > > > its > > > > > > > > > > incorrect to return a 301 or 302 in these scenarios, the > > > correct > > > > > > > > > > response is 404. Not only is it the correct response, but > > > given > > > > > most > > > > > > > > > > sites get 50%-90% of their traffic from Google, and Google > > > thinks > > > > > its > > > > > > > > > > also correct to return 404 ( > > > > >http://www.google.com/url?sa=D&q=http:// > > > > > > > > > > googlewebmastercentral.blogspot.com/2008/08/farewell-to- > > > > > > > > > > soft-404s.html, its in our best financial interest to play > > > nice > > > > > with > > > > > > > > > > Google. > > > > > > > > > > > > Specifically for 404 (when a template is not found we > > > > > > > > > > > could > > > do > > > > > > > > > > > something like: > > > > > > > > > > > > 1. In LiftRules instead of: > > > > > > > > > > > > type URINotFoundPF = PartialFunction[(Req, Box[Failure]), > > > > > > > > > > > LiftResponse] > > > > > > > > > > > > use > > > > > > > > > > > > type URINotFoundPF = PartialFunction[(Req, Box[Failure]), > > > > > > > Either[List > > > > > > > > > > > [String], LiftResponse]] > > > > > > > > > > > > so that function can return a template path instead of > > > > > response. > > > > > > > > > > > > 2. In LiftSession#processRequest instead of applying the > > > normal > > > > > > > > > > > request pipeline only if the addressed template is found, > > > we > > > > > can > > > > > > > use > > > > > > > > > > > the path obtained from LiftRules.uriNotFound if Lift fails > > > to > > > > > find > > > > > > > the > > > > > > > > > > > normal tempalte. Hence apply the normal rendering pipeline > > > to > > > > > the > > > > > > > > > > > template referenced by uriNotFound. > > > > > > > > > > > > This approach allows your 404 case to be handled by the > > > normal > > > > > > > > > > > rendering pipeline without other hacks. > > > > > > > > > > > > Unless someone thinks this is a bad solution, Alex you > > > could > > > > > open > > > > > > > an > > ... > > read more » -- You received this message because you are subscribed to the Google Groups "Lift" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/liftweb?hl=en.
