Filters

Filter

Filters provide filtering tasks either on the request or the response or both. Filters can be chained, multiple Input/Output filters can be applied to an incoming request or be used to transform the output response. The Handle Filter is simply a full blown Controller and can take complete control of the request/response exactly like a Controller.

1. In Filter

   Responsible for filtering the incoming request entity. It can be implemented with the following method signature,

   void doInputFilter(HttpRequest *req)

   Marker Based

   (Header)

   #ifndef DEFAULTIOFILTER_H_
   #define DEFAULTIOFILTER_H_
   
   #include "Filter.h"
   #include <iostream>
   
   #pragma @Filter type="in" path="*"
   class DefaultIOFilter {
   public:
   	void doInputFilter(HttpRequest *req);
   };
   
   #endif

   (Source)

   #include "DefaultIOFilter.h"
   
   void DefaultIOFilter::doInputFilter(HttpRequest *req)
   {
   	//Process the input request here...
   	cout << "Processed input request" << endl;
   }

   XML Based

   (Header)

   #ifndef DEFAULTIOFILTER_H_
   #define DEFAULTIOFILTER_H_
   
   #include "Filter.h"
   #include <iostream>
   
   class DefaultIOFilter: public Filter {
   public:
   	void doInputFilter(HttpRequest *req);
   };
   
   #endif

   (Source)

   #include "DefaultIOFilter.h"
   
   void DefaultIOFilter::doInputFilter(HttpRequest *req)
   {
   	//Process the input request here...
   	cout << "Processed input request" << endl;
   }

   (Configuration)

   <app>
   	<filters>
   		<!-- All requests will be processed by 'DefaultIOFilter' filter -->
   		<filter class="DefaultIOFilter" type="in" />
   	</filters>
   </app>

2. Out Filter

   Responsible for filtering the outgoing response entity. It can be implemented with the following method signature,

   void doOutputFilter(HttpResponse *req)

   Marker Based

   (Header)

   #ifndef DEFAULTIOFILTER_H_
   #define DEFAULTIOFILTER_H_
   
   #include "Filter.h"
   #include <iostream>
   
   #pragma @Filter type="out" path="*"
   class DefaultIOFilter {
   public:
   	void doOutputFilter(HttpResponse *req);
   };
   
   #endif

   (Source)

   #include "DefaultIOFilter.h"
   
   void DefaultIOFilter::doOutputFilter(HttpResponse *req)
   {
   	//Process the output response here...
   	cout << "Processed output response" << endl;
   }

   XML Based

   (Header)

   #ifndef DEFAULTIOFILTER_H_
   #define DEFAULTIOFILTER_H_
   
   #include "Filter.h"
   #include <iostream>
   
   class DefaultIOFilter: public Filter {
   public:
   	void doOutputFilter(HttpResponse *req);
   };
   
   #endif

   (Source)

   #include "DefaultIOFilter.h"
   
   void DefaultIOFilter::doOutputFilter(HttpResponse *req)
   {
   	//Process the output response here...
   	cout << "Processed output response" << endl;
   }

   (Configuration)

   <app>
   	<filters>
   		<!-- All responses will be processed by 'DefaultIOFilter' filter -->
   		<filter class="DefaultIOFilter" type="out" />
   	</filters>
   </app>

3. Handle Filter

   Responsible for filtering both the incoming request as well as the response entity. It can be implemented with the following method signature,

   bool doHandle(HttpRequest *req, HttpResponse* res)

   The following examples combine all the filter type examples below.

   Marker Based

   (Header)

   #ifndef DEFAULTIOFILTER_H_
   #define DEFAULTIOFILTER_H_
   
   #include "Filter.h"
   #include <iostream>
   
   #pragma @Filter type="in" path="*"
   #pragma @Filter type="out" path="*"
   #pragma @Filter type="handle" path="*.filter"
   class DefaultIOFilter {
   public:
   	void doInputFilter(HttpRequest *req);
   	void doOutputFilter(HttpResponse *res);
   	bool doHandle(HttpRequest *req, HttpResponse* res);
   };
   
   #endif

   (Source)

   #include "DefaultIOFilter.h"
   
   void DefaultIOFilter::doInputFilter(HttpRequest *req)
   {
   	//Process the input request here...
   	cout << "Processed input request" << endl;
   }
   
   void DefaultIOFilter::doOutputFilter(HttpResponse *res)
   {
   	//Process the output response here...
   	cout << "Processed output response" << endl;
   }
   
   bool DefaultIOFilter::doHandle(HttpRequest *req, HttpResponse* res)
   {
   	bool continue_proc_request = false;
   	res->setContent("Filter handled your request as you visited a *.filter location");
   	res->setHTTPResponseStatus(HTTPResponseStatus::Ok);
   	return continue_proc_request;
   }

   XML Based

   (Header)

   #ifndef DEFAULTIOFILTER_H_
   #define DEFAULTIOFILTER_H_
   
   #include "Filter.h"
   #include <iostream>
   
   class DefaultIOFilter: public Filter {
   public:
   	void doInputFilter(HttpRequest *req);
   	void doOutputFilter(HttpResponse *res);
   	bool doHandle(HttpRequest *req, HttpResponse* res);
   };
   
   #endif

   (Source)

   #include "DefaultIOFilter.h"
   
   void DefaultIOFilter::doInputFilter(HttpRequest *req)
   {
   	//Process the input request here...
   	cout << "Processed input request" << endl;
   }
   
   void DefaultIOFilter::doOutputFilter(HttpResponse *res)
   {
   	//Process the output response here...
   	cout << "Processed output response" << endl;
   }
   
   bool DefaultIOFilter::doHandle(HttpRequest *req, HttpResponse* res)
   {
   	bool continue_proc_request = false;
   	res->setContent("Filter handled your request as you visited a *.filter location");
   	res->setHTTPResponseStatus(HTTPResponseStatus::Ok);
   	return continue_proc_request;
   }

   (Configuration)

   <app>
   	<filters>
   		<!-- All requests with the URL pattern matching *.filter will be processed by 'DefaultIOFilter' filter -->
   		<filter class="DefaultIOFilter" type="handle" path="*.filter" />
   		<!-- All requests will be processed by 'DefaultIOFilter' filter -->
   		<filter class="DefaultIOFilter" type="in" />
   		<!-- All responses will be processed by 'DefaultIOFilter' filter -->					
   		<filter class="DefaultIOFilter" type="out" />
   	</filters>
   </app>