[jboss-jira] [JBoss JIRA] Closed: (JBSEAM-368) STATELESS component injection rules are not intuitive/undocumented

STATELESS component injection rules are not intuitive/undocumented ------------------------------------------------------------------ Key: JBSEAM-368 URL: http://jira.jboss.com/jira/browse/JBSEAM-368 Project: JBoss Seam Issue Type: Bug Components: Core Reporter: Christian Bauer Assigned To: Gavin King Priority: Critical Fix For: 1.1 This is probably a non-issue, so feel free to ignore. It took me a while to figure out why this works: @In(create=true) MyStatelessComponent myComponent; but this doesn't: @In MyStatelessComponent myComponent; It was easy to figure out that it apparently is required, but from looking at the documentation this isn't clear. I also found it difficult to think about "creation of a component" when it is already there in the stateless EJB pool. I checked the code and there is some consistency in the internal logic, of course. Users however might read the docs and say: "@In searches all contexts hierarchically, so it should find myComponent in STATELESS, because Seam logged that binding on startup." Also, attempts to remove the create="true" with @In(value = "myComponent", scope = ScopeType.STATELESS) MyStatelessComponent myComponent; resulted in JNDI lookup("myComponent"), which makes not much sense and returns null. I suggest we add something to the documentation about lookup/injection of stateless components (I'm not sure if I'm 100% right about this, otherwise I would have added it). Side note, I found the following additional debug logging lines in Component.java very helpful during development: private Object getInstanceToInject(In in, String name, Object bean, boolean enforceRequired) { Object result; if ( name.startsWith("#") ) { log.debug("Searching for injection variable with value binding expression: " + name); FacesContext facesCtx = FacesContext.getCurrentInstance(); Application application = facesCtx.getApplication(); result = application.createValueBinding(name).getValue(facesCtx); } else if (in.scope()==ScopeType.UNSPECIFIED) { log.debug("Searching hierarchically for injection variable in all scopes: " + name); result = getInstance(name, in.create()); } else { if ( in.create() ) { throw new IllegalArgumentException( "cannot combine create=true with explicit scope on @In: " + getAttributeMessage(name) ); } log.debug("Searching for injection variable in scope: " + name + ", scope: " + in.scope()); result = in.scope().getContext().get(name); } if (result==null && enforceRequired && in.required()) { throw new RequiredException( "In attribute requires value for component: " + getAttributeMessage(name) ); } else { return result; } }