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Java use-class getting called twice

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Community Advisor

Dear members,

 

I'm using AEM 6.4.4 and using wcm-use along with it. The issue is that my use-class activate() method is getting called twice. Anyone has faced this issue before? I tried debugging it but no luck how it's happening. Any help would be really appreciated.

 

Thanks,

Bilal.

1 Accepted Solution

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Correct answer by
Level 10

Hi @bilal_ahmad,

My first input for this is probably not the answer you're looking for, but... you should think about switching from WCMUse to Sling Models. They allow for more features, are easier to use and are the current best practice for AEM component models. They are better documented and these days I think most people are more used to Sling Models so you're likely to get more and better answers if you ask a question  This would be a good candidate for an upgrade, you may find that it solves your problem!

However, sticking to WCMUse for now:

  1. If your activate() method is being called twice, the most likely reason is that there are two requests being made. How are you making the request to the model? For example, if you have a test page with a bunch of components on it and you are loading that page to test, is it possible that there are 2 components that use the CommonUtilUse model and therefore it is being called twice?
  2. Are you using CommonUtilUse.java anywhere in your Java code (even if you are not directly calling activate())? Becuase activate() is called automatically in some scenarios, so perhaps you are indirectly calling it via your SuperScriptUse.java class or something along those lines?

 

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18 Replies

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Community Advisor

Hi @bilal_ahmad 

 

There must be issue in your custom code as there is no such issue identified in AEM OOB.

You need to debug your code or share your code(HTL+Java) sample for better understanding.

 

Regards,

Arpit

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Community Advisor

Thank you Arpit, for your response. I tried debugging it but the only clue I got is that my activate() method got called twice

Here are my files for your reference:

 

<sly data-sly-use.commonutilobj="${'com.mysite.aem.core.use.CommonUtilUse'}"/>
<div id="${commonutilobj.componentId}" data-tracking-event-label="${commonutilobj.componentLabel}" class="jumbotron ${!properties.backgroundColor ? '': '{0}{1}' @format=[properties.backgroundColor,'-bg']} ${properties.paddingTop} ${properties.paddingBottom} ${properties.alwaysShowImg ? 'alwaysImg' : ''} ${!properties.fileReferencebckgroundimage ? '' : '{0}{1}{2}' @ format=['backgroundImg-',properties.horizontalAlign, properties.verticalAlign]} ${properties.alignment}" style="background-image: url('${properties.fileReferencebckgroundimage @ context='uri'}')"> 
    <div class="wrapper">
		<div class="row" data-sly-test="${properties.H3Title || properties.H5Eyebrow || properties.leadPara}">
			<div class="col-md-8 ${properties.alignment=='text-center'? 'mx-auto':''}">
				<h5 data-sly-test="${properties.H5Eyebrow}" class="alt ${properties.H5EyebrowColor}">${properties.H5Eyebrow ='unsafe'}</h5>
				<h3 data-sly-test="${properties.H3Title}" class="${properties.H3TitleColor}"
					data-sly-use.supuse="${'com.mysite.aem.core.components.use.SuperScriptUse' @ param=properties.H3Title}">${supuse.highlight ='unsafe'}</h3>
				<p data-sly-test="${properties.leadPara}" class="lead2 ${properties.leadParaColor}">${properties.leadPara ='unsafe'}</p>
			</div>
		</div>
	</div>
</div>

 

 

 

wcm-use-error.PNG

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Community Advisor

Hi @bilal_ahmad 

 

I don't see any reason why your activate method is calling twice.

You are using two wcmuse classes in HTL. Can you clarify which one's activate method is getting called twice? and also make sure that in your java code you're not calling activate method manually from another method.

 

Regards,

Arpit

 

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Community Advisor
CommonUtilUse is the WCMUse that I'm talking about. It gets called twice. I removed other pieces from the html file so that only my < sly data-sly-use.commonutilobj ="${'com.mysite.aem.core.use.CommonUtilUse'}" /> gets called. Still I see it getting called twice. However I' m not calling the activate method in this java class/any other java class

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Community Advisor

@bilal_ahmad As you already mentioned that it is only happening for CommonUtilUse class and not for the other one which confirms that there is an issue in your custom code, not an issue AEM known issue.

Whatever code you have shared there is no such code that confirms that it is getting called twice. You need to check and debug your whole code to identify the issue.

 

Regards,

Arpit

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Community Advisor

Thank you @ArpitVarshney, but CommonUtilUse is called only once from this component on this html. I have created a page where there's only one component, this one and then i'm seeing it getting called twice. I have, however other components which use the same java class but if I include them on my page, number of calls further increase in multiple of 2.

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Community Advisor

Can you give a sample of the code how you are invoking the class and just a skeleton of your class (remove any main business logic ) ?

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Community Advisor
Thank you so much Veena. for responding to my issue, also apologies for the delayed response.

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Community Advisor

Thank you so much Veena. for responding to my issue, also apologies for the delayed response. I'll attach the files here:

 

 

<sly data-sly-use.commonutilobj="${'com.mysite.aem.core.use.CommonUtilUse'}"/>
<div id="${commonutilobj.componentId}" data-tracking-event-label="${commonutilobj.componentLabel}" class="jumbotron ${!properties.backgroundColor ? '': '{0}{1}' @format=[properties.backgroundColor,'-bg']} ${properties.paddingTop} ${properties.paddingBottom} ${properties.alwaysShowImg ? 'alwaysImg' : ''} ${!properties.fileReferencebckgroundimage ? '' : '{0}{1}{2}' @ format=['backgroundImg-',properties.horizontalAlign, properties.verticalAlign]} ${properties.alignment}" style="background-image: url('${properties.fileReferencebckgroundimage @ context='uri'}')"> 
    <div class="wrapper">
		<div class="row" data-sly-test="${properties.H3Title || properties.H5Eyebrow || properties.leadPara}">
			<div class="col-md-8 ${properties.alignment=='text-center'? 'mx-auto':''}">
				<h5 data-sly-test="${properties.H5Eyebrow}" class="alt ${properties.H5EyebrowColor}">${properties.H5Eyebrow ='unsafe'}</h5>
				<h3 data-sly-test="${properties.H3Title}" class="${properties.H3TitleColor}"
					data-sly-use.supuse="${'com.mysite.aem.core.components.use.SuperScriptUse' @ param=properties.H3Title}">${supuse.highlight ='unsafe'}</h3>
				<p data-sly-test="${properties.leadPara}" class="lead2 ${properties.leadParaColor}">${properties.leadPara ='unsafe'}</p>
			</div>
		</div>
	</div>
</div>

 

wcm-use-error.PNG

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Community Advisor
I don't see an issue in your code. How did you figure out it is getting called twice ?

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Community Advisor

Thanks for the response, Veena_07
Here's how I found out - I have created a page with only one component(this one) on it.  I start my AEM instance in debug mode and placed a breakpoint at activate() method. when I refresh the page, the control comes to the activate method, it executes, then it gets called again and gets processed. Many Thanks, Bilal.

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Community Advisor

Check your sightly code .

You must be calling your model twice

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Community Advisor

You can try one thing change the name of your model.

And update the same in your sightly code and see.

 

In this way you will be able to confirm its getting called from somewhere else inbyour code.

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Community Advisor
I haven't tried this - going to try and update here. Thanks ton!

Avatar

Correct answer by
Level 10

Hi @bilal_ahmad,

My first input for this is probably not the answer you're looking for, but... you should think about switching from WCMUse to Sling Models. They allow for more features, are easier to use and are the current best practice for AEM component models. They are better documented and these days I think most people are more used to Sling Models so you're likely to get more and better answers if you ask a question  This would be a good candidate for an upgrade, you may find that it solves your problem!

However, sticking to WCMUse for now:

  1. If your activate() method is being called twice, the most likely reason is that there are two requests being made. How are you making the request to the model? For example, if you have a test page with a bunch of components on it and you are loading that page to test, is it possible that there are 2 components that use the CommonUtilUse model and therefore it is being called twice?
  2. Are you using CommonUtilUse.java anywhere in your Java code (even if you are not directly calling activate())? Becuase activate() is called automatically in some scenarios, so perhaps you are indirectly calling it via your SuperScriptUse.java class or something along those lines?

 

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Community Advisor

wow! @Theo_Pendle such a detailed answer :). thank you for your time and attention at this. Well, I agree to you that I(or rather we, the development team) should migrate our code and start using latest practices(sling model in this case) I'd say that we are already on that path, but migrating slowly from old practices to the new ones.
Now, for your raised points,

1. I'm having a page where only one component which uses this class is present, still two calls to activate method.

2. I'm not referring CommonUtilUse.java in another java class so that there might be a possibility that it's activate() is getting called anyway.

 

I appreciate your explanation, though. Thanks, Bilal.

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Community Advisor
Hello @Theo_Pendle, I was migrating all JAVA SCR annotaions to OSGi DS annotation, and to my surprise, after replacing the annotations the problem seems to have resolved by itself(I have no idea how!). I placed the debugger at WCMUse activate method and it got called only once! Strange but any clue what might've caused it? Many Thanks, Bilal.

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Level 10
That sounds like one of those programming mysteries that will never be solved... just don't let it keep you up at night