Immutable context

[lukaszlenart]

This PR uses the latest OGNL version which drops access to #context via a magical key and makes OgnlContext a bit immutable.

OGNL 3.2 version notes

Implements WW-4927

[cnenning]

Sounds like a very good idea! A short check showed that my apps are not affected 😆

[yasserzamani]

Below is my new design which may be helpful as an example for whom is affected. Those are about access to %{#context['com.opensymphony.xwork2.dispatcher.HttpServletRequest'].requestURI}.

I wrote following Filter which operates after struts-prepare but before struts-execute. It supplies an utility into request scope:

package utils;

import java.io.IOException;

import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;

import org.apache.struts2.StrutsStatics;
import com.opensymphony.xwork2.ActionContext;
import com.opensymphony.xwork2.util.ValueStack;

/**
 * @author zamani
 *
 */
public class MYStrutsPrepareFilter implements Filter {

	private MYUtils MYUtils;

	@Override
	public void init(FilterConfig filterConfig) throws ServletException {
		MYUtils = new MYUtils();
	}

	@Override
	public void doFilter(ServletRequest req, ServletResponse res, FilterChain chain)
			throws IOException, ServletException {

		ValueStack stack = ActionContext.getContext().getValueStack();
		stack.setValue("#request['MYUtils']", MYUtils);
		
		chain.doFilter(req, res);
	}

	@Override
	public void destroy() {
		MYUtils = null;
	}

	
	public class MYUtils {
		public String getRequestURI() {
			HttpServletRequest httpsr = ((HttpServletRequest) ActionContext.getContext()
					.get(StrutsStatics.HTTP_REQUEST));
			return httpsr.getRequestURI();
		}
	}
}

Then "#request['MYUtils'].requestURI" can be used in jsp, instead.

[aleksandr-m]

Spotted same #context['com.opensymphony.xwork2.dispatcher.HttpServletRequest'] expression here. @yasserzamani What do you use it for?

[yasserzamani]

@aleksandr-m , not me but my workmate has used it as an ID for each jsp. I do not know his work details but in general, he then uses this ID to decide where he should place the result after an AJAX call. For example a parent jsp that have div1, div2 and div3 calls an AJAX then if result was from '/APP/jsp/customer/error.jsp' then it puts the result in div3, if result was from '/APP/jsp/customer/payment.jsp' then it puts the result in div1, if result was from '/APP/jsp/customer/free.jsp' then it puts the result in div2.

[asfgit]

Can one of the admins verify this patch?

[coveralls]

Coverage decreased (-0.0007%) to 46.168% when pulling a37eafa on lukaszlenart:immutable-context into 845ab41 on apache:master.

[coveralls]

Coverage increased (+0.05%) to 46.214% when pulling 058409e on lukaszlenart:immutable-context into 845ab41 on apache:master.

[lukaszlenart]

@apache/struts-committers this is ready for another look.

[aleksandr-m]

What is the deal with the type converter?

[lukaszlenart]

Good question, probably it's a workaround :/ Need to re-think this.

[lukaszlenart]

Whooops... it can be thrown away, goot catch 👍

[yasserzamani]

Will result be used in restore method as state parameter? if so I think it should be Boolean.FALSE.

[lukaszlenart]

Hm... this was copy/pasted from existing code but I think you are right.

[lukaszlenart]

done :)

[yasserzamani]

LGTM 👍 Thanks!