Revision: 7652
Author: rj...@google.com
Date: Wed Mar 3 15:11:02 2010
Log: Edited wiki page through web user interface.
http://code.google.com/p/google-web-toolkit/source/detail?r=7652
Modified:
/wiki/RequestFactoryPlusPaths.wiki
=======================================
--- /wiki/RequestFactoryPlusPaths.wiki Wed Mar 3 15:01:26 2010
+++ /wiki/RequestFactoryPlusPaths.wiki Wed Mar 3 15:11:02 2010
@@ -35,131 +35,128 @@
In this example, {{{ employees().findEmployee(e.getId()) }}} is creating
an instance of a request object. That's important: findEmployee() isn't an
rpc call, it's a factory call to create an instance of something like
FindEmployeeRequest. Later on that will go over the wire to be interpreted
by the server, probably as part of a batch at the end of the current
eventloop.
-{{{ Employee }}} is another product of our tool, and embodies the id and
properties of a server side entity class, e.g. Employee.DISPLAY_NAME. See
a full fledged example of it in the blip below.
-
-requests.values.subscribe() is a call to ValueStore#subscribe(Path), which
does the following:
-
-It establishes a subscription keyed from the last entity + property of the
path to an appropriate HasValue. In this case, myName is subscribed to
Employee e's DISPLAY_NAME.
-It fires off the request that anchors the path (findEmployee()) to ensure
the necessary property value is available, perhaps short circuiting if such
a call is already cached.
-Once we have the DISPLAY_NAME value, it is pushed to myName.setValue().
-Whenever e's DISPLAY_NAME is updated it is pushed again, until the
subscription is dropped.
+{{{ Employee }}} is another product of our tool, and embodies the id and
properties of a server side entity class, e.g. {{{ Employee.DISPLAY_NAME
}}}. See a full fledged example of it in the blip below.
+
+{{{ requests.values.subscribe() }}} is a call to {{{
ValueStore#subscribe(Path) }}}, which does the following:
+
+ * It establishes a subscription keyed from the last entity + property
of the path to an appropriate HasValue. In this case, myName is subscribed
to Employee e's DISPLAY_NAME.
+ * It fires off the request that anchors the path (findEmployee()) to
ensure the necessary property value is available, perhaps short circuiting
if such a call is already cached.
+ * Once we have the DISPLAY_NAME value, it is pushed to
myName.setValue().
+ * Whenever e's DISPLAY_NAME is updated it is pushed again, until the
subscription is dropped.
If we can assume that every entity class has an appropriate findFoo()
method, this can be simpler:
+{{{
requests.values.subscribe(e
-.newPathThrough(Employee.DISPLAY_NAME)
-.to(myName));
+ .newPathThrough(Employee.DISPLAY_NAME)
+ .to(myName));
+}}}
It's not hard to imagine an annotation that would cause the above to be
generated. (Pretend GWT.create() has actually been made useful and now
accepts helper arguments.)
+{{{
+
class EmployeeDisplay extends Composite implements HasValue<Employee> {
-private static final UiBinder UI_BINDER =
-GWT.create(UiBinder.class, EmployeeDisplay.class);
-private static final HasValueSupport DATA_BINDER =
-GWT.create(HasValueSupport.class, EmployeeDisplay.class);
-
-// works w/data binder b/c field name matches property
-// If it didn't match, could add @Path("displayName")
-...@uifield HasValue<String>displayName;
-
-private ValueStore values;
-
-public void setValueStore(ValueStore values) { this.values = values; }
-public void setValue(Employee value) {
-DATA_BINDER.setValue(this, values, value);
-}
+ private static final UiBinder UI_BINDER =
+ GWT.create(UiBinder.class, EmployeeDisplay.class);
+ private static final HasValueSupport DATA_BINDER =
+ GWT.create(HasValueSupport.class, EmployeeDisplay.class);
+
+ // works w/data binder b/c field name matches property
+ // If it didn't match, could add @Path("displayName")
+ @UiField HasValue<String>displayName;
+
+ private ValueStore values;
+
+ public void setValueStore(ValueStore values) { this.values = values; }
+ public void setValue(Employee value) {
+ DATA_BINDER.setValue(this, values, value);
+ }
}
-Here's a more interesting path:
+}}}
+
+Here's a more interesting path, to show someone's boss's name. Note that
the subscription will keyed directly to the boss entity, not to the
e.MANAGER.DISPLAY_NAME path.
+
+{{{
HasValue<String> bossName = new TextField();
requests.values.subscribe(e
-.newPathThrough(Employee.MANAGER)
-.through(Employee.DISPLAY_NAME)
-.to(bossName));
+ .newPathThrough(Employee.MANAGER)
+ .through(Employee.DISPLAY_NAME)
+ .to(bossName));
+
+}}}
For list values, we assume a HasValueList interface, which looks a lot
like John L's ListHandler. (I'm cheating a bit, would really need both
display name and id in the ListBox for this to be useful, but just to get
the idea across):
+{{{
+
HasValueList<String> employeeList = new ListBox();
requests.values.subscribe(
-requests.employees().findAllEmployees()
-.forProperty(Employee.DISPLAY_NAME)
-.newPathTo(employeeList));
-
-
-Employee.java
-
+ requests.employees().findAllEmployees()
+ .forProperty(Employee.DISPLAY_NAME)
+ .newPathTo(employeeList));
+
+}}}
+
+= Employee.java =
+
+{{{
@ServerType(com.google.gwt.sample.valuebox.domain.Employee.class)
-
public class Employee implements Entity {
-
-private final String id;
-
-private final Integer version;
-
-
-Employee(String id, Integer version) {
-
-this.id = id;
-
-this.version = version;
-
+ private final String id;
+ private final Integer version;
+
+ Employee(String id, Integer version) {
+ this.id = id;
+ this.version = version;
+ }
+
+ @javax.validation.constraints.Size(min = 2, max = 30)
+ public static final Property<Employee, String> USER_NAME =
+ new Property<Employee, String>(Employee.class, String.class);
+
+ @javax.validation.constraints.Size(min = 2, max = 30)
+ public static final Property<Employee, String> DISPLAY_NAME =
+ new Property<Employee, String>(Employee.class, String.class);
+
+ @javax.validation.constraints.NotNull
+ public static final Property<Employee, Employee> SUPERVISOR =
+ new Property<Employee, Employee>(Employee.class, Employee.class);
+
+ public String getId() {
+ return id;
+ }
+
+ public Integer getVersion() {
+ return version;
+ }
}
-...@javax.validation.constraints.size(min = 2, max = 30)
-
-public static final Property<Employee, String> USER_NAME = new
Property<Employee, String>(
-
-Employee.class, String.class);
-
-public static final Property<Employee, String> DISPLAY_NAME = new
Property<Employee, String>(
-
-Employee.class, String.class);
-
-public static final Property<Employee, Employee> SUPERVISOR = new
Property<Employee, Employee>(
-
-Employee.class, Employee.class);
-
-
-public String getId() {
-
-return id;
-
-}
-
-public Integer getVersion() {
-
-return version;
-
-}
-
-}
-
-Entity.java
-
+}}}
+
+= Entity.java =
+
+{{{
public interface Entity {
-
-Object getId();
-
-Comparable<?> getVersion();
-
-}
-
-HasValueList.java
-
+ Object getId();
+ Comparable<?> getVersion();
+}
+}}}
+
+= HasValueList.java =
+
+{{{
public interface HasValueList<V> {
-
-void editValueList(boolean replace, int index, List<V> newValues);
-
-void setValueList(List<V> newValues);
-
-void setValueListSize(int size, boolean exact); // @jlabanca: What does
exact
-
-// mean?
-
-}
-
-
+ void editValueList(boolean replace, int index, List<V> newValues);
+ void setValueList(List<V> newValues);
+
+ // @jlabanca: What does exact mean?
+ void setValueListSize(int size, boolean exact);
+}
+}}}
+
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