Sling Model instantiation AEM 6.3

[sukumard]

Hi,

As per my observation on AEM 6.3, when we drag and drop our components, the sling model associated with component instantiates immediately.

my Sling Model  is like this :- @Model(adaptables = SlingHttpServletRequest.class) with injectors like below

@Inject @Via("resource")

    @Optional

    private String message;

Is this observation is correct ? if yes, is there any way to stop this instantiation and just show the placeholder and upon authoring in dialog, create the instance of the model ?

Thanks in advance.

[edubey · Accepted solution]

AFAIK,  it's the correct observation.

You would probably have to add check in your @PostConstruct method Apache Sling :: Sling Models or HTL  (formerly known as Sightly)

[sukumard]

hi,

@PostConstruct will be called after all injections , while i want to stop instantiation of sling model during drag and drop.

[edubey]

I don't think so you can do it.

Best case, you can try to add a check on the sightly element where you add this class.

Thanks

[atyaf66]

If you wrap your data-sly-use inside a data-sly-test that evaluates to false it will not be evaluated.

for example, let's say you have a simple text component with one simple authored property "simpleText"
You want to NOT instantiate the model if  "simpleText" is NOT authored

you can do the following

```

<!-- NOTE the use of data-sly-test on the same element as the  data-sly-use -->

<sly data-sly-test="${properties.simpleText}" data-sly-use.TextModel="package.path.to.model.Text"/>

<div>

    <h1>placeholder</h1>

    <h1>text is: ${properties.simpleText}</h1>

</div>

```
The model will only instanciate if simpleText is authored and will not otherwise.

you can always make a simple component and test.