Validate a value used to produce entity/entities

brunobieth · **Joined:** Tue May 29, 2007 4:46 am **Posts:** 6

Hello,

I'm using a String to build entities. How can I validate this String ?

Here is an example :

Code:

@Entity
class Question {
        [...]

        @OneToMany( cascade=CascadeType.ALL)
        private List< Option > options;
   
        transient String optionsText;

        public void setOptions(List<Option> options) {
                this.options = options;
      
                // convert options in optionsText
                [...]
        }

        public void setOptionsText(String optionsText) {
               // convert optionsText in options
               String lines[] = optionsText.split( separator );
               [...]
        }

        [...]
}

Code:

class Option {
        [...]
        @Length(min=1, max=50)
   private String text;
}

So I would like to validate all the produced options. I quickly imagined something like :

Code:

class Question {
        [...]

        @TransformationConstraint( "optionMaker" )
        transient String optionsText;


        @Transformator( "optionMaker" )
        public static List< Option > makeOptions( String optionsText ) {
             [...]
        }

        public void setOptionsText( String txt ) {
             // use makeOptions
             [...]
        }
}

The @Transformator annotation register a transformator with id optionMaker. Then we can use it in @TransformationConstraint.

Ok this is just an idea, maybe something easier / cleaner is possible.
Thanks for your comments.

Bruno

emmanuel · **Posted:** Tue May 29, 2007 3:15 pm

I don't understand what you are trying to achieve, what @Transformator does?

brunobieth · **Joined:** Tue May 29, 2007 4:46 am **Posts:** 6

Well, I'm writing a questionnaire maker. So the user can make questions. The questions may have options. I found convenient to create the options from a textarea (=String) using line-break to split them.

The problem now is validating this string in order to have valid generated options.

My thought was to define a converter/transformator for String to option list (here is the @Transformator annotation) and then tell the validator to use it for validating a property (@TransformationConstraint).

From the validator point of view : get the transformator with id "optionMaker", invoke it with the property and validate the result (which is an entity or entities).

brunobieth · **Joined:** Tue May 29, 2007 4:46 am **Posts:** 6

Well, I'm writing a questionnaire maker. So the user can make questions. The questions may have options. I found convenient to create the options from a textarea (=String) using line-break to split them.

The problem now is validating this string in order to have valid generated options.

My thought was to define a converter/transformator for String to option list (here is the @Transformator annotation) and then tell the validator to use it for validating a property (@TransformationConstraint).

From the validator point of view : get the transformator with id "optionMaker", invoke it with the property and validate the result (which is an entity or entities).

emmanuel · **Posted:** Wed May 30, 2007 12:28 pm

So I guess you are looking for @Valid on the collection, it will validate each Option object recursively

brunobieth · **Joined:** Tue May 29, 2007 4:46 am **Posts:** 6

Ok that sounds good ! I'll try tomorrow. Thank you.

BTW I posted few messages on the french forum (about the validator again) but everything has been removed. I think because I replied to a SPAM ...
The old account was mustaghattack

emmanuel · **Posted:** Thu May 31, 2007 1:25 pm

Why on earth would you reply to a spam??