Hi Matthias, Catagay, please describe your approach with DI, especially interested in Master-Detail scenario - how would you do that with DI
for example: SearchBeanA returns the list of BeanA - and showing them in h:dataTable () now user chooses an item in table and a detail page must be shown - properties of BeanA are linked to the detail page. How would you load through the DI the BeanA from SearchBeanA? Thanks, Anton 2009/4/27 Matthias Wessendorf <[email protected]> > On Mon, Apr 27, 2009 at 12:09 PM, Georg Füchsle <[email protected]> > wrote: > > Thanks Matthias, > > > > I do not use EL API, and I don't understand what you mean by > DI-container. > > in fact, you are using the API: > > javax.faces.el.ValueBinding vb =app.... > > cleaner solution is using some DI container > (e.g. spring) > > > > > > > But I can show you the following example: > > > > I have an application scoped bean and a session scoped bean > (MbSessionBean) > > In my application scoped bean I found code like that: > > > > public String getImageUrl() > > { > > int layout = > (MbSessionBean)getManagedBean("mbsessionbean").getLayout(); > > > > if(layout == 1) > > return "/pages/imageone.jpg"; > > else > > return "/pages/imagetwo.jpg"; > > } > > > > > > > > protected static final Object getManagedBean(String beanName) > > { > > > > Object ob; > > FacesContext facesContext = > FacesContext.getCurrentInstance(); > > Application app = facesContext.getApplication(); > > javax.faces.el.ValueBinding vb > =app.createValueBinding("#{"+beanName+"}"); > > ob = vb.getValue(facesContext); > > return ob; > > } > > > > > > > > Of course this is not nice code, because I ask user dependent data > > from a method of an application scoped bean. > > But I wonder how it can work. > > > > How does the application bean know which session scoped bean it should > ask? > > it uses the one from the current user. Using the API like you do is a > giant hack. > I'd not do it, even it works... This code will cause errors and "fun" > in the future > of the application. > > > > > Obviously it works. But does it only work by chance, ( for example > > because there has never been 2 or more session beans with different > > data at the same time...) or does it really work? > > > > If it works (even the code is ugly) I could let it this way now and > > clean it another time.... > > > > > > Cheers Georg > > > > > > 2009/4/27 Matthias Wessendorf <[email protected]>: > >> I'd not do that... > >> > >> generally fetching beans by using the EL API is not that good. > >> Use a real DI container for that > >> > >> -M > >> > >> On Mon, Apr 27, 2009 at 11:22 AM, Georg Füchsle < > [email protected]> wrote: > >>> Hallo, > >>> > >>> I found such things in my code: > >>> > >>> In an static method of an application scoped bean I fetch a session > >>> scoped bean and read some data from it. > >>> It seems to work. But is it really allowed? > >>> > >>> Georg > >>> > >> > >> > >> > >> -- > >> Matthias Wessendorf > >> > >> blog: http://matthiaswessendorf.wordpress.com/ > >> sessions: http://www.slideshare.net/mwessendorf > >> twitter: http://twitter.com/mwessendorf > >> > > > > > > -- > Matthias Wessendorf > > blog: http://matthiaswessendorf.wordpress.com/ > sessions: http://www.slideshare.net/mwessendorf > twitter: http://twitter.com/mwessendorf >
