On May 3, 2011, at 9:27 AM, Kieran Kelleher wrote:
> There are a few different approaches. It seems everyone has to create one when they start programming WebObjects.
Unless you use ERD2W... then you get it for free (^_^)
...
> On May 3, 2011, at 9:40 AM, Peter Müller wrote:
>
>>
>> But what can I do, until the book reach me? How can I display the messages, Wonder generates for me?
Wonder generates localized validation messages. The pretty messages are stored in Project/Resources/Lang.lproj/ValidationTemplate.strings files in all projects and frameworks. For instance, if you look in ERExtensions/Resources/English.lproj/ValidationTemplate.strings you'll see
"NullPropertyException" = "Please provide a <b..displayNameForProperty@@</b>.";
Which will be templated into "Please provide a <b>username</b>." automatically for you by wonder. You'll notice wonder already has templates for 7 different languages. When you decide to add more languages to your app, you just add a Localizable.strings file to your app for each language and define your display name like
"PropertyKey.username" = "Login ID";
Or whatever in each language you support. I believe the message is already available and translated into your appropriate session.language() whenever it arrives in your WOComponent's validationFailedWithException(Throwable th, Object value, String key). So all you need to do to get the pretty message is return th.getMessage() somewhere.
If you have custom validation that you would like to implement for this object, then you need to first decide if this validation *should* be in your model. If it is display logic, then bind to a component variable and put the validation method in you component. If it is model logic (ex. username must be minimum of 8 characters) then you can bind to your object and implement a validation method on your model object. Either way, the method signature looks the same. Example:
public String validateUsername(String username) {
if(username.length() < 8) {
ERXValidationFactory factory = ERXValidationFactory.defaultFactory();
ERXValidationException ex = factory.createCustomException(this, "username", username, "MinimumLengthException");
throw ex;
}
return username;
}
Then in your ValidationTemplate.strings file add:
"MinimumLengthException" = "The value of <b..displayNameForProperty@@</b> is not long enough.";
and perhaps something a bit more specific for your user entity like:
"User.username.MinimumLengthException" = "<b..displayNameForProperty@@</b> must be at least <b>8</b> characters long!";
Wonder will automatically handle any validation it can based on your model. If an attribute is required and the value is null, it will throw a NullPropertyException through the factory before validateUsername() is ever called.
**DO NOT attempt to alter the state of the EO in validation methods. In the above example, you can coerce username and return it as any value you like, but do not attempt to set the value of any other attribute or relationship inside a validation method. That is bad. It will seem to work at first, but you are violating an EOF commandment and you will pay for it later when strange, unexplainable editing context errors start to occur. Set values in willUpdate, willInsert, init, or other methods intended to be used for that purpose. Validation methods are purely for validating the state of the object and coercing the argument passed in.
Ramsey
>>
>> How can I display the messages, if I want to use the wonder-generated Validation-Messages?
>>
>> Thanks
>> Peter M.
>>
>>
>> -------- Original-Nachricht --------
>>> Datum: Tue, 3 May 2011 08:51:53 -0400
>>> Von: Kieran Kelleher <kelleher..mail.com>
>>> An: woproject-de..bjectstyle.org, "Peter Müller" <peter.mueller193..mx.net>
>>> Betreff: Re: Validation on my own
>>
>>> You can implement custom validation by simply adding validation methods to
>>> any class that implements NSValidation interface.
>>>
>>> You can throw custom 'nice' message from your own Validation method.
>>>
>>> Also, if you use Wonder, the default messages will be 'nice' and Wonder
>>> allows for nice localization too.
>>>
>>> There is a bit for you to learn, but it will be worth it.
>>>
>>> So for your user EO, you can add custom validation methods.
>>>
>>> For example for your password logic below, this would normally be added in
>>> the EO class as sth like:
>>>
>>> public String validatePassword(Object aValue) throws
>>> NSValidation.ValidationException {
>>> if (aValue == null || aValue.toString().length() < 5) {
>>> throw new NSValidation.ValidationException("Password must be
>>> set and must contain at least 5 characters.");
>>> }
>>> return aValue.toString();
>>> }
>>>
>>> Your validate method gets called automatically in takeValuesFromRequest
>>> phase of request handling.
>>>
>>> Your current approach will not work because you are validating in the
>>> invokeAction phase which comes after the takeValues phase.
>>>
>>> There is a book written by a bourbon-loving fairly smart Canuck entitled
>>> "Practical WebObjects". Chapter 5 explains Validation in very easy to
>>> understand terms. If you read that, you will then know enough to be dangerous.
>>> ;-)
>>>
>>> Regards, Kieran
>>>
>>>
>>> On May 3, 2011, at 8:31 AM, Peter Müller wrote:
>>>
>>>> Hello WO-Community,
>>>> i've a coding-problem because WO does a job for me, I want to do on my
>>> own.
>>>>
>>>> I've a modelclass called "User" with a view fields:
>>>> id, firstname, lastname, email, ...
>>>>
>>>> id is primary key, firstname, lastname and a view others are "required"
>>> fields.
>>>>
>>>> On my component I have a Form to set this fields. The "save"-Button is
>>> linked to my method:
>>>>
>>>> public WOComponent save() {
>>>> alertMessage=null;
>>>> if(selectedUser.lastname()==null) {
>>>> alertMessage="Lastname of user must be set!";
>>>> return null;
>>>> }
>>>> if(selectedUser.firstname()==null) {
>>>> alertMessage="Firstname of user must be set!";
>>>> return null;
>>>> }
>>>> if(selectedUser.username()==null) {
>>>> alertMessage="Username of user must be set!";
>>>> return null;
>>>> }
>>>> if(selectedUser.password()==null ||
>>> selectedUser.password().length()<5) {
>>>> alertMessage="Password of user must be set and must contain at least
>>> 5 signs.";
>>>> return null;
>>>> }
>>>> session.defaultEditingContext().saveChanges();
>>>> selectedUser = null;
>>>> return null;
>>>> }
>>>>
>>>> As you can see, I want to do the validation for the fields on my own
>>> (because I want to make a "nice" message to the user, and later also
>>> multilingual).
>>>>
>>>> But now the problem: If I click "save" on my component, first the form
>>> will be set, and WO validates, if all required fields are set. If not, it
>>> will print a message in console and "reset" the fields. My validation will be
>>> ignored.
>>>>
>>>> Have I any chance to validate "required" fields on my own, and ignore
>>> WO's validation?
>>>>
>>>> Thank you very much,
>>>> All the best from germany
>>>> Peter M.
>>>> --
>>>> Empfehlen Sie GMX DSL Ihren Freunden und Bekannten und wir
>>>> belohnen Sie mit bis zu 50,- Euro! https://freundschaftswerbung.gmx.de
>>>
>>
>> --
>> NEU: FreePhone - kostenlos mobil telefonieren und surfen!
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>
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