How to programmatically set a required attribute?

[shin0135]

Hi,

I have an injected property which has a required attribute false.

@In(required=false)
private MyDto dto;

I would like to convert above to like this:

private MyDto dto = (MyDto)Component.getInstance(MyDto.class);

How can I set a required attribute programatically?

Thank you for your help!

[amitev]

@In(create=true)

creates the component for you.

[shin0135]

Thanks Adrian for the answer.

I'm just curious to ask,

private MyDto dto = (MyDto)Component.getInstance(MyDto.class);

is the above equivalent to

@In(required=false)
private MyDto dto;

I'm trying to remove @In without losing any benefits of seam bijection provides.

When I used Component.getInstance, it didn't complain about non-null required of dto. Does this mean both methods are equal to use?

[amitev]

No, it's not equivalent.

private MyDto dto = (MyDto)Component.getInstance(MyDto.class);

creates a component if it doesn't exist in the scope

@In(required=false)
private MyDto dto;

this just performs a dependency injection

[kragoth]

James S. wrote on Mar 26, 2010 16:08:


Hi,

I have an injected property which has a required attribute false.

@In(required=false)
private MyDto dto;

I would like to convert above to like this:

private MyDto dto = (MyDto)Component.getInstance(MyDto.class);

How can I set a required attribute programatically?

Thank you for your help!

You can't actually set the required attribute programmatically. However, you should get the same behavior by doing this:

private MyDto dto = (MyDto)Component.getInstance(MyDto.class, false);

What this means is: Inject an instance of MyDto.class if and only if one exits in my current context(s). Doing this is basically the same as setting required=false. The boolean represents the decision to create an instance if one does not exist.

[shin0135]

Thanks for your clarification, Adrian and Tim.

Now I understand what I was wrong.

Again, thanks for your help!