Home » Eclipse Projects » Eclipse Platform » [Databinding] Trigger validation via my code
| [Databinding] Trigger validation via my code [message #330941] |
Mon, 18 August 2008 15:53  |
Eclipse User |
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Hi,
can I trigger the validation for the UI fields via code?
I have a "copy" function which creates a copy of an existing object and
opens an editor which uses databinding for the model -> UI connectivity.
I have my own validator which checks the "name" field so that it does
not contain a name which is already in use.
But the check is only performed if the user enters something in the
field (SWT.Modify). As far as I know SWT.FocusOut or SWT.None would also
not help.
So how can I trigger the validation via my code without something
ridiculous like this:
// Trigger the validation
// Remember the old value
String text = nameText.getText();
// Put in nonsense
nameText.setText("Hello");
// And back to the old value
nameText.setText(text);
Best regards, Lars
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| Re: [Databinding] Trigger validation via my code [message #331040 is a reply to message #331001] |
Thu, 21 August 2008 16:08  |
| Eclipse User |
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Hi Matthew,
ok, I'll extract an example and post it as soon as possible.
Best regards, Lars
Matthew Hall wrote:
> Lars,
>
> Could you provide a standalone snippet demonstrating the problem? It's
> hard to guess the source of your problem without seeing more code.
>
> Matthew
>
> Lars Vogel wrote:
>> Matthew Hall wrote:
>>> Lars,
>>>
>>> What are you using to display the validation status?
>>>
>>
>> Hi Matthew,
>>
>> AggregateValidationStatus, e.g.:
>>
>>
>> final IObservableValue validationStatus = new AggregateValidationStatus(
>> bindingContext.getBindings(),
>> AggregateValidationStatus.MAX_SEVERITY);
>> validationStatus.addChangeListener(new IChangeListener() {
>> public void handleChange(ChangeEvent event) {
>> IStatus status = (IStatus) validationStatus.getValue();
>> if (status.isOK()) {
>> form.setMessage("", IMessageProvider.NONE);
>> } else {
>>
>> form
>> .setMessage(status.getMessage(),
>> IMessageProvider.ERROR);
>> }
>> }
>> });
>>
>> Best regards, Lars
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| Re: [Databinding] Trigger validation via my code [message #331104 is a reply to message #331001] |
Mon, 25 August 2008 08:56 |
| Eclipse User |
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Hi Matthew,
attached a small example which is a small modification of:
http://dev.eclipse.org/viewcvs/index.cgi/org.eclipse.jface.e xamples.databinding/src/org/eclipse/jface/examples/databindi ng/snippets/Snippet004DataBindingContextErrorLabel.java?view =markup
Best regards, Lars
----------------
package org.eclipse.jface.examples.databinding.snippets;
import org.eclipse.core.databinding.AggregateValidationStatus;
import org.eclipse.core.databinding.Binding;
import org.eclipse.core.databinding.DataBindingContext;
import org.eclipse.core.databinding.UpdateValueStrategy;
import org.eclipse.core.databinding.beans.PojoObservables;
import org.eclipse.core.databinding.observable.ChangeEvent;
import org.eclipse.core.databinding.observable.IChangeListener;
import org.eclipse.core.databinding.observable.Realm;
import org.eclipse.core.databinding.observable.list.IObservableList ;
import org.eclipse.core.databinding.observable.value.IObservableVal ue;
import org.eclipse.core.databinding.validation.IValidator;
import org.eclipse.core.databinding.validation.ValidationStatus;
import org.eclipse.core.runtime.IStatus;
import org.eclipse.core.runtime.Status;
import org.eclipse.jface.databinding.swt.SWTObservables;
import org.eclipse.jface.dialogs.MessageDialog;
import org.eclipse.swt.SWT;
import org.eclipse.swt.layout.GridLayout;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.Label;
import org.eclipse.swt.widgets.Shell;
import org.eclipse.swt.widgets.Text;
/**
* Snippet that displays how to bind the validation error of the
* {@link DataBindingContext} to a label. http://www.eclipse.org
*
* @since 3.2
*/
public class Snippet004ModifiedDataBindingContext {
public static void main(String[] args) {
final Display display = new Display();
Realm.runWithDefault(SWTObservables.getRealm(display), new Runnable() {
public void run() {
MyClass test = new MyClass();
test.setFirstName("Jim");
Shell shell = new Shell(display);
shell.setText("Data Binding Snippet 004 - Modified");
shell.setLayout(new GridLayout(2, false));
new Label(shell, SWT.NONE).setText("Enter 'Joe' to be valid:");
Text text = new Text(shell, SWT.BORDER);
new Label(shell, SWT.NONE).setText("Error:");
DataBindingContext dbc = new DataBindingContext();
// Bind the text to the value.
dbc.bindValue(SWTObservables.observeText(text, SWT.Modify),
PojoObservables.observeValue(test, "firstName"),
new UpdateValueStrategy()
.setAfterGetValidator(new FiveValidator()),
null);
final IObservableValue validationStatus = new AggregateValidationStatus(
dbc.getBindings(),
AggregateValidationStatus.MAX_SEVERITY);
validationStatus.addChangeListener(new IChangeListener() {
public void handleChange(ChangeEvent event) {
IStatus status = (IStatus) validationStatus.getValue();
if (!status.isOK()) {
MessageDialog.openError(new Shell(display),
"Error", status.getMessage());
}
}
});
IObservableList bindings = dbc.getBindings();
for (Object object : bindings) {
if (object instanceof Binding) {
((Binding) object).validateTargetToModel();
}
}
shell.pack();
shell.open();
while (!shell.isDisposed()) {
if (!display.readAndDispatch())
display.sleep();
}
}
});
display.dispose();
}
/**
* Validator that returns validation errors for any value other than 5.
*
* @since 3.2
*/
private static class FiveValidator implements IValidator {
public IStatus validate(Object value) {
return ("Joe".equals(value)) ? Status.OK_STATUS : ValidationStatus
.error("the value was '" + value + "', not 'Joe'");
}
}
public static class MyClass {
private String firstName = "";
public void setFirstName(String firstName) {
this.firstName = firstName;
}
public String getFirstName() {
return firstName;
}
}
}
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| Re: [Databinding] Trigger validation via my code [message #331115 is a reply to message #331113] |
Mon, 25 August 2008 19:00 |
| Eclipse User |
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Lars,
Try this:
IObservableValue statusObservable = new WritableValue();
statusObservable.addChangeListener(new IChangeListener() {
// your change listener code
});
dbc.bindValue(statusObservable, new AggregateValidationStatus(
dbc.getBindings(), AggregateValidationStatus.MAX_SEVERITY),
null, null);
Matthew
Lars Vogel wrote:
> Hi Matthew,
>
> I'm using Eclipse forms and I'm using the message manager. Binding the
> validation a label would be a step back. Also the early binding doesn't
> work for me as in my real example I'm providing the data to the
> composite after creating the UI.
>
> So there is really no other way to trigger the validation then this:
>
>
>
>
> Matthew Hall wrote:
>> Lars,
>>
>> The change listener doesn't work because AggregateValidationStatus
>> computes the initial status (which is an error in this case) when it
>> is constructed. So there is no change event being fired (and thus no
>> error message being displayed) until the *next* change in the text
>> field. A few possible ways to fix this:
>>
>> 1) Construct the AggregateValidationStatus before creating any
>> bindings, and add the listener at that time. This works for this
>> small example but may be brittle in production use.
>> 2) (Recommended) Use a value binding to bind the validation status to
>> a label. See the attached revised snippet to see what I mean.
>>
>> Hope this helps,
>>
>> Matthew
>>
>> Lars Vogel wrote:
>>> Hi Matthew,
>>>
>>> attached a small example which is a small modification of:
>>> http://dev.eclipse.org/viewcvs/index.cgi/org.eclipse.jface.e xamples.databinding/src/org/eclipse/jface/examples/databindi ng/snippets/Snippet004DataBindingContextErrorLabel.java?view =markup
>>>
>>>
>>> Best regards, Lars
>>
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| Re: [Databinding] Trigger validation via my code [message #331116 is a reply to message #331115] |
Mon, 25 August 2008 18:33 |
| Eclipse User |
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Hi Matthew,
cool, this works.
Thank you very much.
Best regards, Lars
Matthew Hall wrote:
> Lars,
>
> Try this:
>
> IObservableValue statusObservable = new WritableValue();
> statusObservable.addChangeListener(new IChangeListener() {
> // your change listener code
> });
>
> dbc.bindValue(statusObservable, new AggregateValidationStatus(
> dbc.getBindings(), AggregateValidationStatus.MAX_SEVERITY),
> null, null);
>
> Matthew
>
> Lars Vogel wrote:
>> Hi Matthew,
>>
>> I'm using Eclipse forms and I'm using the message manager. Binding the
>> validation a label would be a step back. Also the early binding
>> doesn't work for me as in my real example I'm providing the data to
>> the composite after creating the UI.
>>
>> So there is really no other way to trigger the validation then this:
>>
>>
>>
>>
>> Matthew Hall wrote:
>>> Lars,
>>>
>>> The change listener doesn't work because AggregateValidationStatus
>>> computes the initial status (which is an error in this case) when it
>>> is constructed. So there is no change event being fired (and thus no
>>> error message being displayed) until the *next* change in the text
>>> field. A few possible ways to fix this:
>>>
>>> 1) Construct the AggregateValidationStatus before creating any
>>> bindings, and add the listener at that time. This works for this
>>> small example but may be brittle in production use.
>>> 2) (Recommended) Use a value binding to bind the validation status to
>>> a label. See the attached revised snippet to see what I mean.
>>>
>>> Hope this helps,
>>>
>>> Matthew
>>>
>>> Lars Vogel wrote:
>>>> Hi Matthew,
>>>>
>>>> attached a small example which is a small modification of:
>>>> http://dev.eclipse.org/viewcvs/index.cgi/org.eclipse.jface.e xamples.databinding/src/org/eclipse/jface/examples/databindi ng/snippets/Snippet004DataBindingContextErrorLabel.java?view =markup
>>>>
>>>>
>>>> Best regards, Lars
>>>
--
Lars Vogel
http://www.vogella.de/eclipse.html - Tutorials about Eclipse
http://www.vogella.de/articles/RichClientPlatform/article.ht ml - Eclipse
RCP Tutorial
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