Re: Freemarker help - unable to access http request in ftl

[Siegfried Goeschl <si...@gmail.com>]

Hi Harsha,

Any progress or update to your problem at hand?

Thanks in advance, 

Siegfried Goeschl



> On 26.02.2019, at 17:22, Woonsan Ko <wo...@apache.org> wrote:
> 
> Hi Harsha,
> 
> On Mon, Feb 25, 2019 at 6:17 PM Harsha Thota <harshathota@gmail.com <ma...@gmail.com>> wrote:
>> 
>> Hi,
>> 
>> We have a jersey based web application. We use Apache Freemarker for the
>> front end web pages. We integrate the Freemarker in our application using
>> the jersey-mvc-freemarker. In our web app we register the
>> FreeMarkerMvcFeature.class in the ResouceConfig on Startup. In our java
>> code, we return a Viewable which gets rendered in the FTL.
>> 
>> I have created a servlet Filter and added it in out web.xml. This filter
>> intercepts all the http requests. In the doFilter method of that Filter, I
>> am getting the HTTPSession from the HTTP request and setting an attribute
>> value. Say "myVal".
>> 
>> myVal should now be set on the HTTPSession in the HTTPServletRequest. I am
>> not able to access this myVal in the FTL page. I tried doing a lot of
>> research and also posted the question in stack overflow[
>> https://stackoverflow.com/questions/54835683/freemarker-httpsession-attribute-returning-null]
>> but I did not get any proper response.
> 
> How do you execute a Template? Do you invoke somewhere either
> freemarker.template.Template.process(Object model, Writer), or
> template.createProcessingEnvironment(Object model, Writer).process()?
> If so, you need to pass all the model objects you want to use through
> the model argument. Otherwise, the template cannot know what kind of
> variables are available. You can use a map for the model argument:
> 
> Map<String, Object> context = new HashMap<String, Object>();
> context.put("foo", new Foo());
> 
> Then you will be able to use ${foo.something}.
> 
>> 
>> I have tried to do the following:
>> 
>> I have updated Freemarker to the latest version: 2.3.28
>> 
>> I have also tried adding the servlet[
>> https://freemarker.apache.org/docs/pgui_misc_servlet.html] mentioned in the
>> Freemarker documentation to my web.xml and tried the following ways to
>> access the myVal:
>> 
>> ${Request.myVal}
>> 
>> ${myVal}
> 
> Are you sure if your filter is invoked before the FreemarkerServlet
> and if your filter sets "myVal" as a request attribute?
> If so, ${myVal} should work fine as FreemarkerServlet will resolve it
> from HttpServletRequest.getAttribute("myVal").
> 
> Regards,
> 
> Woonsan
> 
>> 
>> ${Request.Session.myVal}
>> 
>> ${Session.myVal}
>> 
>> All the above values are "null" and the below exception is thrown
>> 
>> FreeMarker template error (DEBUG mode; use RETHROW in production!): The
>> following has evaluated to null or missing: ==> Request [in template
>> "home.ftl" at line 18, column 3]
>> 
>> *---- Tip: If the failing expression is known to legally refer to something
>> that's sometimes null or missing, either specify a default value like
>> myOptionalVar!myDefault, or use <#if
>> myOptionalVar??>when-present<#else>when-missing. (These only cover the last
>> step of the expression; to cover the whole expression, use parenthesis:
>> (myOptionalVar.foo)!myDefault, (myOptionalVar.foo)?? ---- ---- FTL stack
>> trace ("~" means nesting-related): - Failed at:
>> ${Request.Session.user_privilages} [in template "home.ftl" at line 18,
>> column 1]*
>> 
>> Please suggest on how I can access the http request in the FTL page. It
>> would be a great help for my project.
>> 
>> Please help. Thank you.
>> Regards,
>> Harsha Thota
>> 1 (470)-535-2763 || harshathota@gmail.com
>> https://www.linkedin.com/in/thotaharsha