[web-devel] Type-safe URL handling

[Jeremy Shaw]

The latest version of the code is now at:

http://src.seereason.com/web-routes/

- jeremy

On Fri, Mar 26, 2010 at 5:36 AM, Victor Nazarov
<asviraspossible at gmail.com>wrote:

> On Thu, Mar 25, 2010 at 11:31 PM, Jeremy Shaw <jeremy at n-heptane.com>
> wrote:
> > Hello Victor,
> > The current version of urlt already has template haskell code for
> > automatically generating the url from the data type. There is an example
> of
> > that in WaiExample.hs.
> > I find that the TH is great when developing the application, because it
> > 'just works'. But when the app gets closer to release, I sometimes want
> to
> > customize the way the urls look. (for seo, etc). The nice part is that I
> can
> > just write some custom instances of PathInfo instead of deriving them,
> and
> > all of the other code just works.
> > Is there something more that you wanted the TH code to do?
>
> It sounds just like what I want. Where is the latest code to check it out?
>
> >
> > On Thu, Mar 25, 2010 at 12:11 PM, Victor Nazarov <
> asviraspossible at gmail.com>
> > wrote:
> >>
> >> On Thu, Mar 25, 2010 at 6:48 AM, Michael Snoyman <michael at snoyman.com>
> >> wrote:
> >> >
> >> >
> >> > On Wed, Mar 24, 2010 at 3:36 PM, Jeremy Shaw <jeremy at n-heptane.com>
> >> > wrote:
> >> >>
> >> >> On Mon, Mar 22, 2010 at 9:41 PM, Michael Snoyman <
> michael at snoyman.com>
> >> >> wrote:
> >> >>>
> >> >>> If I'm not mistaken, I think that addresses all the issues on the
> >> >>> table;
> >> >>> is there anything left to decide? I look forward to seeing a sample
> >> >>> URLT :).
> >> >>
> >> >> There were other issues that came up, but nothing exciting enough to
> >> >> talk
> >> >> about.
> >> >> I have pushed a patch which I think brings the code up to date in
> terms
> >> >> of
> >> >> functionality. See WaiExample for a detail of everything that is
> >> >> currently
> >> >> supported (aside from the happstack / hsp stuff).
> >> >> The next steps are to:
> >> >>  1. change the names of any functions or types that we do not
> currently
> >> >> like
> >> >>  2. add the haddock documentation
> >> >>  3. split the package into separate packages so that you don't have
> to
> >> >> pull in extra dependencies that you aren't going to use
> >> >>  4. turn the WaiExample into a literate tutorial / blog post
> >> >>  5. add a (simple) happstack example as well
> >> >> So take a look and let me know what you think. Especially in regards
> to
> >> >> #1.
> >> >> Then we can also look into how to extend the yesod mkResources stuff
> to
> >> >> work with this new code.
> >> >> from a parsing point of view, we almost don't have to do anything, we
> >> >> could just do:
> >> >>  [mkResource|  "/foo/:int/:int" = \i j -> mySite (Foo i j) |]
> >> >> or whatever the syntax is. But that does not solve the issue of how
> to
> >> >> go
> >> >> from (Foo 1 2) back to /foo/1/2 and ensure that it is the inverse
> >> >> operation.
> >> >>
> >> > I don't have time right now to look at the code, but I will soon (I'm
> in
> >> > the
> >> > middle of traveling *again*). Regarding the mkResource issue, I think
> >> > it's
> >> > slightly more complicated, and what I was thinking of was a
> combination
> >> > of
> >> > TemplateHaskell and QuasiQuotes to address it:
> >> > * The quasi-quoted content will follow mostly the same syntax, though
> >> > allowing you to specify the name of the constructor you wish to assign
> >> > to
> >> > each resource pattern.
> >> > * Since we now will need to have multiple top-level definitions being
> >> > generated, quasi-quoting alone won't solve the issue. So I will have a
> >> > quasi-quote function to convert the YAML syntax to a StringObject, and
> >> > then
> >> > a TH function to convert the StringObject to:
> >> >   1) A datatype for the URL.
> >> >   2) A pair to to/from functions.
> >> >   3) A dispatch function.
> >> > This is the point at which having WebPlug/HandleT becomes useful.
> >> > If that was too vague, just let me know and I'll clarify ;).
> >>
> >> Hello, everybody.
> >>
> >> I haven't been following the entire thread. But I think that typed
> >> URLs are great. When I started thinking about typed URLs, I thought
> >> about using only data type definition and dropping quosi-quotation
> >> entirely in favour of template haskell. I wanted to write some
> >> template haskell function to work on data-type declaration, it would
> >> use data-constructors names and arguments and build path components
> >> from their names. So we will need no new notation to describe
> >> application resources, we will never be conserned with URL generator
> >> and parser, we will work with our own, carefully defined data-type as
> >> it IS a URL.
> >>
> >> --
> >> Victor Nazarov
> >
> >
>
>
>
> --
> Victor Nazarov
>
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