Calling protected constructor from class extension

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Hi,
I created an extension class according to all rules, but I get a bunch of errors, saying that the parent class (HcmWorkerTransition) is not visible due to protection level (by default it is declared as just a class, so I suppose it is public). The same is said about the parent class methods, although they are declared as protected. What could possibly cause it? Thank you.

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Martin Dráb 236,019 Most Valuable Professional on at

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RE: Calling protected constructor from class extension

In that case, what you need can't be done by class extensions.

Not only you can use normal object-oriented concepts such as inheritance - it's what you should be using in the first place. And yes, using object-oriented programming is definitely a good practice.

You're not the only one who got distracted by this new feature and forgot about normal object-oriented design.

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RE: Calling protected constructor from class extension

The thing is that when I customize the class, the method I add is a copy of a method but a bit edited to receive one more variable. So the instance has to be created in this method (which is impossible if it doesn't inherit) and other methods from the HcmWorkerTransition class must be used, which is also impossible I suppose. What if I just created a class that inherits from HcmWorkerTransition and use all those methods? would it be something like extension, a good practice?

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Martin Dráb 236,019 Most Valuable Professional on at

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RE: Calling protected constructor from class extension

You're still missing the point that we're talking about class extensions, not extension methods. Please look at the last example (Common_Extension) in my blog post about class extensions; I explicitly use "this" there. I also explain there how class extensions work.

Note that I wasn't referring explicitly to ascNewCreateHcmWorker() - I wrote my answer before Dsatkus shared this method. If I'm right about what he's trying to achieve, the fact that the method is static is just another bug.

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Basheer17 2,720 on at

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RE: Calling protected constructor from class extension

If your new method is static you have to pass the first parameter as base class object. Since "this" keyword can't be used in static methods.

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Martin Dráb 236,019 Most Valuable Professional on at

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RE: Class extension

That's the correct behavior - you can't access protected constructors from classes outside the inheritance hierarchy. Extension classes are completely separate classes and therefore they can't access protected members.

Why would you create a new instance anyway? Don't you rather want to refer to the instance you're extending? If so, simply use the variable called this.

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RE: Class extension

not to get you confused but this is the real piece of code:

[ExtensionOf(classStr(HcmWorkerTransition))]

final class ASCHcmWorkerTransition_Extension

{

ASCWorkerCategoryEnum hcmWorkerCategory;

static HcmWorkerRecId ascNewCreateHcmWorker(

ASCWorkerCategoryEnum _hcmWorkerCategory,

DirPersonName _dirPersonName,

HcmPersonnelNumberId _personnelNumber,

CompanyInfoRecId _legalEntityRecId = CompanyInfo::find().RecId,

HcmEmploymentType _hcmEmploymentType = HcmEmploymentType::Employee,

validFromDateTime _validFrom = DateTimeUtil::minValue(),

validToDateTime _validTo = DateTimeUtil::maxValue()

, EmployeeId_RU _employeeId = ''

)

{

HcmWorkerTransition hcmWorkerTransition = new HcmWorkerTransition();

hcmWorkerTransition.parmLegalEntityRecId(_legalEntityRecId);

hcmWorkerTransition.parmHcmEmploymentType(_hcmEmploymentType);

HcmWorkerTransition.ascParmHcmWorkerCategory(_hcmWorkerCategory);

hcmWorkerTransition.parmValidFrom(_validFrom);

hcmWorkerTransition.parmValidTo(_validTo);

}

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Martin Dráb 236,019 Most Valuable Professional on at

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RE: Class extension

Basheeruddin, you seem to be talking about extension methods, not class extensions. Class extensions requires an additional attribute (ExtensionOf), but then you don't have to hande the object reference by yourself as the first parameter (and it has several extra features).

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RE: Class extension

sure :

[ExtensionOf(classStr(HcmWorkerTransition))]

final class ASCHcmWorkerTransition_Extension

{

HcmWorkerTransition hcmWorkerTransition = new HcmWorkerTransition(); // I cant access the class constructor

}

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Martin Dráb 236,019 Most Valuable Professional on at

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RE: Class extension

May I ask you again to show us your actual code? We can't just guess what you've written.

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Basheer17 2,720 on at

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RE: Class extension

You can write your new method in the _extension class. Keep first parameter as your base class, and whenever your new method is called pass the base class object. In this way you can access other methods of your base class in your extension method using object reference.

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