In the simplest case, T5 thinks that the options in the drop down list are
all strings.
In your case, they are Brands. The Select component doesn't know how to
create a client-side representation of a Brand (it doesn't magically know to
use the id).
You must provide a ValueEncoder that can convert between Brands and
client-side string values. This is the encoder parameter of the Select
component.
On 5/4/07, Joel Wiegman <[EMAIL PROTECTED]> wrote:
Not to be harsh, but I don't think I've ever written a select box with
constant values (Enum). Seems like even Male/Female drop downs need to
be data-driven now-a-days. :->
I've started to stub out a very simple "real world example" of a select
component in T5, but it doesn't appear to be as simple as I thought it
would be.
A shiny nickel to anyone that can spot the flaw, because I sure can't...
I'm new to Tapestry in general so I could be missing something really
mundane here, but seems like it should work in my mind.
Here are the players:
<< THE ERROR >>
[ERROR] DefaultRequestExceptionHandler Processing of request failed with
uncaught exception: com.foo.data.Brand cannot be cast to
java.lang.String
java.lang.ClassCastException: com.foo.data.Brand cannot be cast to
java.lang.String
at
org.apache.tapestry.corelib.components.Select$1.toClient(Select.java:62)
at
org.apache.tapestry.corelib.components.Select.writeOptions(Select.java:1
94)
at
org.apache.tapestry.corelib.components.Select.options(Select.java:169)
at
org.apache.tapestry.corelib.components.Select.beforeRenderTemplate(Selec
t.java)
<< Main.html (abridged) >>
<t:form>
<select t:type="select" t:id="brand" value="brand"
model="brandSelectModel"/>
</t:form>
<< Main.java (abridged) >>
package com.foo.pages;
import com.foo.data.Brand;
public class Main {
private Brand brand;
public Brand getBrand() {
return brand;
}
public void setBrand(Brand brand) {
this.brand = brand;
}
public BrandSelectModel getBrandSelectModel() {
return new BrandSelectModel(getBrands());
}
public List<Brand> getBrands() {
List<Brand> brands = new ArrayList<Brand>();
brands.add(new Brand("1", "Brand 1"));
brands.add(new Brand("2", "Brand 2"));
brands.add(new Brand("3", "Brand 3"));
return brands;
}
}
<< Brand.java (abridged) >>
package com.foo.data;
public class Brand {
private String id;
private String description;
public Brand() {}
public Brand(String id, String description) {
this.id = id;
this.description = description;
}
public String getId() {
return id;
}
public String getDescription() {
return description;
}
}
<< BrandSelectModel.java >>
package com.foo.uisupport;
import com.foo.data.Brand;
public class BrandSelectModel implements SelectModel {
private List<Brand> brands;
public BrandSelectModel(List<Brand> brands) {
this.brands = brands;
}
public List<OptionGroupModel> getOptionGroups() {
return null;
}
public List<OptionModel> getOptions() {
List<OptionModel> optionModelList = new
ArrayList<OptionModel>();
for(Brand brand: brands) {
optionModelList.add(new
OptionModelImpl(brand.getDescription(), false, brand, new String[0]));
}
return optionModelList;
}
}
---------------------------------------------------------------------
To unsubscribe, e-mail: [EMAIL PROTECTED]
For additional commands, e-mail: [EMAIL PROTECTED]
--
Howard M. Lewis Ship
TWD Consulting, Inc.
Independent J2EE / Open-Source Java Consultant
Creator and PMC Chair, Apache Tapestry
Creator, Apache HiveMind
Professional Tapestry training, mentoring, support
and project work. http://howardlewisship.com
