Medieval Programming

Published by Fabian on 20 Mar 2008 at 10:54 am

if cascade

        if (initialisePools()) {
            if (replicateServices()) {
                if (replicateLocations()) {
                    if (replicateLocationData()) {
                        if (replicateContacts()) {
                            if (replicatePackages()) {
                                if (replicateCustomers()) {
                                    if (replicateCompanies()) {
                                        if (replicateGroups()) {
                                            replicateUsers();
                                            ok=true;
                                        }
                                    }
                                }
                            }
                        }
                    }
                }
            }
        }

        ok = initialisePools() && replicateServices()
             && replicateLocations() && replicateLocationData()
             && replicateContacts() && replicatePackages()
             && replicateCustomers() && replicateCompanies()
             && replicateGroups() && replicateUsers();

8 Comments java,programming

8 Responses to “if cascade”

1. 

   NiKo on 20 Mar 2008 at 12:21 pm #

   Hey, this looks like a filterchain, or equivalent. Could be refactored as something like this (2mn coded, should be heavily enhanced):

   class Chain
   {
       index = 0;
       $first = new $this->services[$this->index];
       $first->execute($this);
     }
     public function next()
     {
       $this->index++;
       if (!array_key_exists($this->index, $this->services))
       {
         // Chain has been entirely executed
         echo "Done.\n";
         return;
       }
       $next = new $this->services[$this->index];
       $next->execute($this);
     }
   }
    
   class Replication_Services
   {
     public function execute(Chain $chain)
     {
       echo "Running ".__CLASS__."\n";
       if (true) // Do your stuff to check if chain should be continued here
       {
         $chain->next();
       }
     }
   }
    
   class Replication_Locations
   {
     public function execute(Chain $chain)
     {
       echo "Running ".__CLASS__."\n";
       if (true) // Do your stuff to check if chain should be continued here
       {
         $chain->next();
       }
     }
   }
    
   $chain = new Chain;
   $chain->run();

2. 

   NiKo on 20 Mar 2008 at 12:22 pm #

   Ok, here’s a link for the code above http://www.hashbin.com/1RE

3. 

   NiKo on 20 Mar 2008 at 12:28 pm #

   OOPS, it’s java here, I missed it :p

   But I guess the patter should apply anyway

4. 

   Guildenstern on 20 Mar 2008 at 1:54 pm #

   no proposal but an annotation:

   is the execution order of these functions relevant? If yes I wouldn’t like your proposal Fabian, because non-expert programmers might no know in which order the if statement is processed. Since I don’t JAVA I have no clue. My C++ compiler would resolve this from left to right but is that really specified?

5. 

   Fabian on 20 Mar 2008 at 2:16 pm #

   Its a standard left to right short circuit boolean operations. I am not aware of a language not doing so

6. 

   Fabian on 27 Mar 2008 at 11:55 am #

   in the same code i found:

           //some code here
           myPs.execute();
           if (myPs!= null)
               myPs.close();
           //some code here

   lovely

7. 

   Guildenstern on 08 Apr 2008 at 3:36 pm #

   I found today something like this:

   int retval;
   retval = foo1();
   if (retval == SUCCESS)
   {
      retval = foo2();
     if (retval == SUCCESS)
     {
        retval = foo3();
   (...)
    }
   }

   up to foo8()
   but at least with different else clauses

8. Apotomo Cookbook » Blog Archive » Using Cells View Inheritance to clean up your views on 12 Apr 2010 at 8:00 pm #

   [...] start getting really ugly when there are more conditions to respect and end up in a medieval if-cascade. It’s geting even worse when those deciders are copied and spread across multiple [...]

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