Thank you to both for your replies.
After reading and rereading the documentation, I'm getting a much better
understanding of how (and how not) to use Tapestry.
I'm trying to integrate with Cayenne without using the outdated integration
module, and so far it's going well and I figured out my way around the
coercion. Since my background is in WebObjects, I had to get used to this
completely different paradigm.
Jonathan
On Thu, Jan 27, 2022, 16:26 Thiago H. de Paula Figueiredo <
thiag...@gmail.com> wrote:
> On Fri, Jan 21, 2022 at 12:56 AM Jonathan Meijer <jonny.mei...@gmail.com>
> wrote:
>
> > Hi,
> >
>
> Hi!
>
>
> > New Tapestry user here, started with a bootstrapped 5.7.3 and
> > experimenting.
> >
>
> Welcome to Tapestry! We just released 5.8.0, by the way.
>
>
> > <t:actionlink t:id="delete" context="test">Delete</t:actionlink>
> >
>
> I suggest using EventLink instead of ActionLink. Very similar, but easier
> and more elegant to use.
>
> <t:eventlink event="delete" context="test">Delete</t:eventlink>
>
> Object onDelete(...) { ... }
>
>
> > What am I doing wrong? There is really no room for error, the Blah
> class
> > is defined right there in the same class and the current row object has
> > absolutely no reason to be converted to String.
> >
>
> You passed an instance of Blah as the context of an ActionLink. This
> component needs to know how to convert Blah to a string to be put in the
> link's URL and how to do the conversion back so Tapestry can provide the
> Blah instance to be passed to the event handler method when you click the
> link. This is done by implementing the ValueEncoder instance for your class
> then contributing it to the ValueEncoderSource service. Internally, when a
> ValueEncoder isn't found for a given type, Tapestry tries to fallback on
> using a coercion from String to type and type to String from the
> TypeCoercer service. That's why I'm suggesting ValueEncoder and Voker is
> suggesting a coercion and both solutions are valid. :) I just prefer the
> ValueEncoder route in this case because it's specific for URLs (including
> page activation context, event handler parameters, etc) and TypeCoercer is
> more general-purpose conversions, specially for component and page
> parameters (for example, Grid's source parameter receives a GridDataSource
> but you can pass a List to it).
>
> Example of ValueEncoder usage:
>
> public class BlahValueEncoder implements ValueEncoder<Blah> {
> public String toClient(Blah value) {
> (...)
> }
>
> public Blah toValue(String clientValue)
> {
> (...)
> }
> }
>
> In AppModule:
>
> public static void
> contributeValueEncoderSource(MappedConfiguration<Class, Object>
> configuration) {
> configuration.add(Blah.class, new BlahValueEncoder()); // or, with
> dependency injection: configuration.addInstance(Object.class,
> BlahValueEncoder.class);
> }
>
>
>
> >
> > Kindly help,
> >
> > Jonathan
> >
>
>
> --
> Thiago
>
