Ken Paulsen wrote:
>
> Thanks Anissa for this good detailed description. Here's some more
> info on the "why" it's this way...
Actually thanks for taking the time and explains to us the cause. I
can only say out the 'symptoms', and you analysis it in detail. You are
a terrific doctor :-)
thanks
Anissa.
>
> redirect() -- Causes the "browser" to submit a 2nd request to
> retrieve the next page.
>
> Since this is a separate request, request parameters may be added
> to the URL that you are requesting. It also means that it is not
> the first request -- i.e. your request attributes will be gone.
> The browser treats all urls as relative to the current page it
> knows about... so yes, it will be relative. Java applications
> have the concept of a "context root" which makes urls that start
> with "/" sometimes confusing. Since the context-root should not
> be hard-coded in the app (in most cases), it may be useful to add
> a handler to help generate a full path that includes the
> context-root -- a redirect will need this for absolute paths.
>
> navigate() -- The server renders the next page during the current request.
>
> The same request that processes the "navigate()" handler will be
> sending the response. So while processing the response, the
> request attributes are still available -- request attributes live
> until the request ends. The request *parameters* (i.e.
> QUERY_STRING parameters, or
> "?paramName=paramVal&another=something" types of parameters),
> cannot be added to a request. The Servlet API's do not allow
> this. So you may not add these types of parameters. You can
> work-a-round this by passing via request attributes, pageSession,
> session, or application as appropriate. The navigate handler
> takes a "viewId" which, as Anissa pointed out, is relative to the
> context-root.
>
> As for beforeCreate events, this event only gets fired during
> *creation* not during refresh. Use *initPage* if you need to fire
> the event every request (including refresh). Navigating to the
> same page may reuse the page and therefor not call
> beforeCreate(). If you are seeing that beforeCreate is not called
> ever when using navigate()... then this is a bug and should be
> filed! I don't think this is the case.
>
> Thanks Anissa... these are great points!
>
> Ken
>
>
> Anissa Lam wrote:
>> Hi,
>> I just want to share with you something that i observed with using
>> navigate() and redirect() handler. They behave quite differently and
>> you may want to decide which is the right one for you when you need
>> to go to another page.
>> Here is what i observed:
>>
>> - redirect() :
>> the attribute you set before calling this will *NOT* be available
>> at the new page
>> the request parameter will be available though
>> the page parameter that you specify has to be relative from the
>> page you are on. You can't use absolute path or assuming it starts
>> from context root.
>>
>> - navigate(): just the opposite of redirect,
>> - the request attribute will be available
>> - the request parameter will *NOT* be available.
>> - if you get to this page via a navigate, any attribute you set
>> during a <!beforeCreate> of the page will lost before it even get to
>> the <!beforeEncode>. To avoid this problem, try to set your
>> attributes in <!beforeEncode> unless you absolutely need that for
>> creating the components.
>> - the page parameter is from context root.
>>
>> I spent quite some time playing with these in order to be able to
>> show errors in admingui.
>> I have attached a testNavigate.jsf that shows you the above findings.
>>
>> thanks
>> Anissa.
>> ------------------------------------------------------------------------
>>
>>
>> <sun:page id="page1">
>> <!beforeCreate
>> setPageSessionAttribute(key="nextPage" value="testNavigate.jsf");
>> println(value="before Create : nextPage = '#{nextPage}', errorSummary = '#{errorSummary}'" );
>> />
>>
>> <!beforeEncode
>> println(value="before Encode : nextPage = '#{nextPage}', errorSummary = '#{errorSummary}'" );
>> />
>>
>> <sun:html id="html2">
>>
>> <sun:alert id="pageAlert" type="error" summary="#{errorSummary}" /> "<br /><br />
>>
>> <sun:staticText text="Request Parameter foo ='$requestParameter{foo}'" /> "<br /><br />
>> <sun:form id="propertyForm">
>> <sun:button text="Navigate, nextPage=#{nextPage} ,error attr persist but request param is lost" id="navigate" >
>> <!command
>> println(value="Using Navigate");
>> setAttribute(key="errorSummary" value="Since you come here using Navigate, Error is going to occur no matter which button you select. nextPage attribute is lost.");
>> navigate(page="#{nextPage}?foo=BAR");
>> />
>> </sun:button>
>>
>> "<br /><br />
>>
>> <sun:button text = "Redirect nextPage=#{nextPage}, error attr is lost, but request param is there" >
>> <!command
>> println( value="Using Redirect");
>> setAttribute(key="errorSummary" value="summary before Redirect, you will never see this !!! ");
>> redirect(page="#{nextPage}?foo=BAR");
>> />
>> </sun:button>
>>
>> </sun:form>
>> </sun:html>
>> </sun:page>
>>