When should I use h outputLink instead of h commandLink

Question

When should I use an  lt h outputLink gt  instead of an  lt h commandLink gt    I understand that a commandLink generates an HTTP post  I m guessing that outputLink will generate HTTP gets  That said  most of the JSF tutorial material I ve read uses commandLink  almost   exclusively   Context  I am implementing a wee little demo project that shows a header link to a user page  much like Stack Overflow s          and I am not sure if commandLink  perhaps using  faces-redirect true for bookmarkability  or outputLink is the right choice

User · Accepted Answer

The  lt h outputLink gt  renders a fullworthy HTML  lt a gt  element with the proper URL in the href attribute which fires a bookmarkable GET request  It cannot directly invoke a managed bean action method   lt h outputLink value  quot destination xhtml quot  gt link text lt  h outputLink gt    The  lt h commandLink gt  renders a HTML  lt a gt  element with an onclick script which submits a  hidden  POST form and can invoke a managed bean action method  It s also required to be placed inside a  lt h form gt    lt h form gt       lt h commandLink value  quot link text quot  action  quot destination quot    gt   lt  h form gt   The  faces-redirect true parameter on the  lt h commandLink gt   which triggers a redirect after the POST  as per the Post-Redirect-Get pattern   only improves bookmarkability of the target page when the link is actually clicked  the URL won t be  quot one behind quot  anymore   but it doesn t change the href of the  lt a gt  element to be a fullworthy URL  It still remains     lt h form gt       lt h commandLink value  quot link text quot  action  quot destination faces-redirect true quot    gt   lt  h form gt    Since JSF 2 0  there s also the  lt h link gt  which can take a view ID  a navigation case outcome  instead of an URL  It will generate a HTML  lt a gt  element as well with the proper URL in href   lt h link value  quot link text quot  outcome  quot destination quot    gt    So  if it s for pure and bookmarkable page-to-page navigation like the SO username link  then use  lt h outputLink gt  or  lt h link gt   That s also better for SEO since bots usually doesn t cipher POST forms nor JS code  Also  UX will be improved as the pages are now bookmarkable and the URL is not  quot one behind quot  anymore  When necessary  you can do the preprocessing job in the constructor or  PostConstruct of a  RequestScoped or  ViewScoped  ManagedBean which is attached to the destination page in question  You can make use of  ManagedProperty or  lt f viewParam gt  to set GET parameters as bean properties  See also   ViewParam vs  ManagedProperty value    quot   param id  quot   What can  lt f metadata gt    lt f viewParam gt  and  lt f viewAction gt  be used for  Bookmarkability via View Parameters feature How to navigate in JSF  How to make URL reflect current page  and not previous one

User · Answer

I also see that the page loading  performance  takes a long time on using h commandLink than h link  h link is faster compared to h commandLink

[jsf] When should I use h:outputLink instead of h:commandLink?

The answer is

See also:

Examples related to jsf

Examples related to jsf-2

Tags