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Pointless .Net Feature of the Day

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  • Sander RosselS Sander Rossel

    It was heavily used in Entity Framework DB First. I've used them a lot to extend generated classes with my own code. I've never used it for my own classes or outside of generated code.

    Best, Sander sanderrossel.com Continuous Integration, Delivery, and Deployment arrgh.js - Bringing LINQ to JavaScript Object-Oriented Programming in C# Succinctly

    realJSOPR Offline
    realJSOPR Offline
    realJSOP
    wrote on last edited by
    #25

    Sander Rossel wrote:

    It was heavily used in Entity Framework DB First.

    Well, there's your problem - you're using Entity Framework...

    Sander Rossel wrote:

    I've used them a lot to extend generated classes with my own code.

    I prefer to generate my own code.

    ".45 ACP - because shooting twice is just silly" - JSOP, 2010
    -----
    You can never have too much ammo - unless you're swimming, or on fire. - JSOP, 2010
    -----
    When you pry the gun from my cold dead hands, be careful - the barrel will be very hot. - JSOP, 2013

    1 Reply Last reply
    0
    • M Mladen Jankovic

      Judging by the restrictions imposed on partial methods: they cannot have return value (only void) or out parameters, they are intended to have side effects. Whether or not it is disastrous to skip side effect is another question. In original example (logging) it is not.

      C Offline
      C Offline
      CPallini
      wrote on last edited by
      #26

      Yes, indeed. The original example showed a safe usage.

      1 Reply Last reply
      0
      • M Marc Clifton

        The cool thing in the code below is that if you don't define LOGGING, not only does the partial method go away, but any calls to the method are also removed.

        #define LOGGING

        using System;

        namespace PartialMethodTest
        {
        partial class Foo
        {
        partial void Log(string msg);

            public void DoSomething()
            {
                Log("Fizbin");
            }
        }
        

        #if LOGGING
        partial class Foo
        {
        partial void Log(string msg)
        {
        Console.WriteLine(msg);
        }
        }
        #endif

        class Program
        {
            static void Main(string\[\] args)
            {
                new Foo().DoSomething();
            }
        }
        

        }

        Latest Article - A Concise Overview of Threads Learning to code with python is like learning to swim with those little arm floaties. It gives you undeserved confidence and will eventually drown you. - DangerBunny Artificial intelligence is the only remedy for natural stupidity. - CDP1802

        Richard DeemingR Offline
        Richard DeemingR Offline
        Richard Deeming
        wrote on last edited by
        #27

        Of course, you could always simplify that to:

        using System;
        using System.Diagnostics;

        namespace ConditionalMethodTest
        {
        class Foo
        {
        [Conditional("LOGGING")]
        private void Log(string msg)
        {
        Console.WriteLine(msg);
        }

            public void DoSomething()
            {
                Log("Fizbin");
            }
        }
        
        static class Program
        {
            static void Main()
            {
                new Foo().DoSomething();
            }
        }
        

        }

        for exactly the same effect. :) ConditionalAttribute Class (System.Diagnostics) | Microsoft Docs[^]


        "These people looked deep within my soul and assigned me a number based on the order in which I joined." - Homer

        "These people looked deep within my soul and assigned me a number based on the order in which I joined" - Homer

        M 1 Reply Last reply
        0
        • realJSOPR realJSOP

          That's not cool - it's obfuscatory.

          ".45 ACP - because shooting twice is just silly" - JSOP, 2010
          -----
          You can never have too much ammo - unless you're swimming, or on fire. - JSOP, 2010
          -----
          When you pry the gun from my cold dead hands, be careful - the barrel will be very hot. - JSOP, 2013

          R Offline
          R Offline
          Rick York
          wrote on last edited by
          #28

          Exactly what I was going to write.

          "They have a consciousness, they have a life, they have a soul! Damn you! Let the rabbits wear glasses! Save our brothers! Can I get an amen?"

          1 Reply Last reply
          0
          • C CPallini

            Quote:

            but any calls to the method are also removed.

            Wouldn't that be disastrous if the method is intended to produce side-effects?

            M Offline
            M Offline
            Marc Clifton
            wrote on last edited by
            #29

            CPallini wrote:

            Wouldn't that be disastrous if the method is intended to produce side-effects?

            Where I used to work, that was an every day occurrence, both in the code and in the meetings with the managers.

            Latest Article - A Concise Overview of Threads Learning to code with python is like learning to swim with those little arm floaties. It gives you undeserved confidence and will eventually drown you. - DangerBunny Artificial intelligence is the only remedy for natural stupidity. - CDP1802

            C 1 Reply Last reply
            0
            • Sander RosselS Sander Rossel

              It was heavily used in Entity Framework DB First. I've used them a lot to extend generated classes with my own code. I've never used it for my own classes or outside of generated code.

              Best, Sander sanderrossel.com Continuous Integration, Delivery, and Deployment arrgh.js - Bringing LINQ to JavaScript Object-Oriented Programming in C# Succinctly

              M Offline
              M Offline
              Marc Clifton
              wrote on last edited by
              #30

              Sander Rossel wrote:

              It was heavily used in Entity Framework DB First.

              Ah. That explains it. They made a language enhancement to support a bad design to begin with! ;)

              Latest Article - A Concise Overview of Threads Learning to code with python is like learning to swim with those little arm floaties. It gives you undeserved confidence and will eventually drown you. - DangerBunny Artificial intelligence is the only remedy for natural stupidity. - CDP1802

              realJSOPR 1 Reply Last reply
              0
              • M Marc Clifton

                CPallini wrote:

                Wouldn't that be disastrous if the method is intended to produce side-effects?

                Where I used to work, that was an every day occurrence, both in the code and in the meetings with the managers.

                Latest Article - A Concise Overview of Threads Learning to code with python is like learning to swim with those little arm floaties. It gives you undeserved confidence and will eventually drown you. - DangerBunny Artificial intelligence is the only remedy for natural stupidity. - CDP1802

                C Offline
                C Offline
                CPallini
                wrote on last edited by
                #31

                :-D :thumbsup:

                1 Reply Last reply
                0
                • Richard DeemingR Richard Deeming

                  Of course, you could always simplify that to:

                  using System;
                  using System.Diagnostics;

                  namespace ConditionalMethodTest
                  {
                  class Foo
                  {
                  [Conditional("LOGGING")]
                  private void Log(string msg)
                  {
                  Console.WriteLine(msg);
                  }

                      public void DoSomething()
                      {
                          Log("Fizbin");
                      }
                  }
                  
                  static class Program
                  {
                      static void Main()
                      {
                          new Foo().DoSomething();
                      }
                  }
                  

                  }

                  for exactly the same effect. :) ConditionalAttribute Class (System.Diagnostics) | Microsoft Docs[^]


                  "These people looked deep within my soul and assigned me a number based on the order in which I joined." - Homer

                  M Offline
                  M Offline
                  Marc Clifton
                  wrote on last edited by
                  #32

                  Richard Deeming wrote:

                  for exactly the same effect.

                  Yes, but that's not nearly as confusing!

                  Latest Article - A Concise Overview of Threads Learning to code with python is like learning to swim with those little arm floaties. It gives you undeserved confidence and will eventually drown you. - DangerBunny Artificial intelligence is the only remedy for natural stupidity. - CDP1802

                  1 Reply Last reply
                  0
                  • realJSOPR realJSOP

                    Partial methods. I'll let you do your own research, but I cannot identify a single case where the use of a partial method would be beneficial, desired, or warranted.

                    ".45 ACP - because shooting twice is just silly" - JSOP, 2010
                    -----
                    You can never have too much ammo - unless you're swimming, or on fire. - JSOP, 2010
                    -----
                    When you pry the gun from my cold dead hands, be careful - the barrel will be very hot. - JSOP, 2013

                    S Offline
                    S Offline
                    Super Lloyd
                    wrote on last edited by
                    #33

                    Remove partial method, you just broke all WPF user controls! :((

                    A new .NET Serializer All in one Menu-Ribbon Bar Taking over the world since 1371!

                    1 Reply Last reply
                    0
                    • realJSOPR realJSOP

                      Partial methods. I'll let you do your own research, but I cannot identify a single case where the use of a partial method would be beneficial, desired, or warranted.

                      ".45 ACP - because shooting twice is just silly" - JSOP, 2010
                      -----
                      You can never have too much ammo - unless you're swimming, or on fire. - JSOP, 2010
                      -----
                      When you pry the gun from my cold dead hands, be careful - the barrel will be very hot. - JSOP, 2013

                      D Offline
                      D Offline
                      Dominic Burford
                      wrote on last edited by
                      #34

                      I thought this too. What the hell use are partial methods. The only reasonable use I have found for them is when using Xamarin to build an app. You may have a class defined in both the iOS and Android projects and defining a partial class makes sense.

                      "There are two ways of constructing a software design: One way is to make it so simple that there are obviously no deficiencies, and the other way is to make it so complicated that there are no obvious deficiencies. The first method is far more difficult." - C.A.R. Hoare Home | LinkedIn | Google+ | Twitter

                      realJSOPR 1 Reply Last reply
                      0
                      • realJSOPR realJSOP

                        Partial methods. I'll let you do your own research, but I cannot identify a single case where the use of a partial method would be beneficial, desired, or warranted.

                        ".45 ACP - because shooting twice is just silly" - JSOP, 2010
                        -----
                        You can never have too much ammo - unless you're swimming, or on fire. - JSOP, 2010
                        -----
                        When you pry the gun from my cold dead hands, be careful - the barrel will be very hot. - JSOP, 2013

                        K Offline
                        K Offline
                        kalberts
                        wrote on last edited by
                        #35

                        When I learned about partial functions, I immediately embraced it. My project at that time was a protocol stack, with data transport, control and management planes. Each plane is a set of functions completely separated from the other two, but operating on the same protocol layer entity. Partial fuctions allowed me to keep the implementation of the planes completely independent of each other. Obviously, very plane specific functions didn't make use of partial functions, but for e.g. initialization and cleanup it was great. Once you get going with partial functions, you add e.g. logging functions without cluttering up the plain code. When you write test functions, you write a partial function to verify entry and/or exit conditions. In the development phase, you add extensive parameter validation that would be too expensive to run in production code, or you add code for performance measurenment and statitics to detect bottlenecks and excessive resource reuqirements, so they can be fixed before the product is released. Yes, you can put it all into one huge, messy code file with a lot of #ifdef to disable parts of the code. The programmer responsisible for one of the planes will have to wade through lots of code that is ireelevant to his tasks. An update in any of the planes, the log functions, the performance measurement functions, the test and validation functions,... invalidates the source file of every other programmer on the project. Obviously it can be done that way. But I love the partial functions, considering that to be a much better way to do it.

                        1 Reply Last reply
                        0
                        • D Dominic Burford

                          I thought this too. What the hell use are partial methods. The only reasonable use I have found for them is when using Xamarin to build an app. You may have a class defined in both the iOS and Android projects and defining a partial class makes sense.

                          "There are two ways of constructing a software design: One way is to make it so simple that there are obviously no deficiencies, and the other way is to make it so complicated that there are no obvious deficiencies. The first method is far more difficult." - C.A.R. Hoare Home | LinkedIn | Google+ | Twitter

                          realJSOPR Offline
                          realJSOPR Offline
                          realJSOP
                          wrote on last edited by
                          #36

                          I'm not saying partial classes aren't reasonable (hell, I use partial classes), I'm saying partial METHODS aren't.

                          ".45 ACP - because shooting twice is just silly" - JSOP, 2010
                          -----
                          You can never have too much ammo - unless you're swimming, or on fire. - JSOP, 2010
                          -----
                          When you pry the gun from my cold dead hands, be careful - the barrel will be very hot. - JSOP, 2013

                          D 1 Reply Last reply
                          0
                          • realJSOPR realJSOP

                            I'm not saying partial classes aren't reasonable (hell, I use partial classes), I'm saying partial METHODS aren't.

                            ".45 ACP - because shooting twice is just silly" - JSOP, 2010
                            -----
                            You can never have too much ammo - unless you're swimming, or on fire. - JSOP, 2010
                            -----
                            When you pry the gun from my cold dead hands, be careful - the barrel will be very hot. - JSOP, 2013

                            D Offline
                            D Offline
                            Dominic Burford
                            wrote on last edited by
                            #37

                            I can't think of a single use for a partial method either.

                            "There are two ways of constructing a software design: One way is to make it so simple that there are obviously no deficiencies, and the other way is to make it so complicated that there are no obvious deficiencies. The first method is far more difficult." - C.A.R. Hoare Home | LinkedIn | Google+ | Twitter

                            1 Reply Last reply
                            0
                            • realJSOPR realJSOP

                              Partial methods. I'll let you do your own research, but I cannot identify a single case where the use of a partial method would be beneficial, desired, or warranted.

                              ".45 ACP - because shooting twice is just silly" - JSOP, 2010
                              -----
                              You can never have too much ammo - unless you're swimming, or on fire. - JSOP, 2010
                              -----
                              When you pry the gun from my cold dead hands, be careful - the barrel will be very hot. - JSOP, 2013

                              O Offline
                              O Offline
                              Olfello
                              wrote on last edited by
                              #38

                              I do not agree. We have a number of WCF/SOAP projects where we generate code from wsdl and same thing with XML generating code from XSD. I both cases it is beneficial to have additional methods or properties in a separate file. When XSD or WSDL is updated you code is not overwritten during regeneration.

                              realJSOPR 1 Reply Last reply
                              0
                              • M Marc Clifton

                                Sander Rossel wrote:

                                It was heavily used in Entity Framework DB First.

                                Ah. That explains it. They made a language enhancement to support a bad design to begin with! ;)

                                Latest Article - A Concise Overview of Threads Learning to code with python is like learning to swim with those little arm floaties. It gives you undeserved confidence and will eventually drown you. - DangerBunny Artificial intelligence is the only remedy for natural stupidity. - CDP1802

                                realJSOPR Offline
                                realJSOPR Offline
                                realJSOP
                                wrote on last edited by
                                #39

                                Marc Clifton wrote:

                                They made a language enhancement to support a bad design to begin with!

                                That's truth in advertising right there... :)

                                ".45 ACP - because shooting twice is just silly" - JSOP, 2010
                                -----
                                You can never have too much ammo - unless you're swimming, or on fire. - JSOP, 2010
                                -----
                                When you pry the gun from my cold dead hands, be careful - the barrel will be very hot. - JSOP, 2013

                                1 Reply Last reply
                                0
                                • O Olfello

                                  I do not agree. We have a number of WCF/SOAP projects where we generate code from wsdl and same thing with XML generating code from XSD. I both cases it is beneficial to have additional methods or properties in a separate file. When XSD or WSDL is updated you code is not overwritten during regeneration.

                                  realJSOPR Offline
                                  realJSOPR Offline
                                  realJSOP
                                  wrote on last edited by
                                  #40

                                  Once again, this discussion isn't about partial classes - it's about partial METHODS.

                                  ".45 ACP - because shooting twice is just silly" - JSOP, 2010
                                  -----
                                  You can never have too much ammo - unless you're swimming, or on fire. - JSOP, 2010
                                  -----
                                  When you pry the gun from my cold dead hands, be careful - the barrel will be very hot. - JSOP, 2013

                                  1 Reply Last reply
                                  0
                                  • realJSOPR realJSOP

                                    Partial methods. I'll let you do your own research, but I cannot identify a single case where the use of a partial method would be beneficial, desired, or warranted.

                                    ".45 ACP - because shooting twice is just silly" - JSOP, 2010
                                    -----
                                    You can never have too much ammo - unless you're swimming, or on fire. - JSOP, 2010
                                    -----
                                    When you pry the gun from my cold dead hands, be careful - the barrel will be very hot. - JSOP, 2013

                                    J Offline
                                    J Offline
                                    johannesnestler
                                    wrote on last edited by
                                    #41

                                    No Research needed. It's for extending generated Code that may will be re-generated later (so you can not change it because your changes would be overriden). E.g. I use it to extend EF generated Contexts. It's a very nice feature and .NET has many not everyone will use, so don't. But if you do Frameworks or template-code or big systems (or WindowsForms UI) it's very handy…

                                    O 1 Reply Last reply
                                    0
                                    • G GKP1992

                                      Where is YAGNI when you need it. Google trends[^] results sort of agree with your feelings, as do I.

                                      M Offline
                                      M Offline
                                      M chael Luna
                                      wrote on last edited by
                                      #42

                                      Definitely YAGNI. Will definitely be asked about it in a job interview.

                                      1 Reply Last reply
                                      0
                                      • M Marc Clifton

                                        The cool thing in the code below is that if you don't define LOGGING, not only does the partial method go away, but any calls to the method are also removed.

                                        #define LOGGING

                                        using System;

                                        namespace PartialMethodTest
                                        {
                                        partial class Foo
                                        {
                                        partial void Log(string msg);

                                            public void DoSomething()
                                            {
                                                Log("Fizbin");
                                            }
                                        }
                                        

                                        #if LOGGING
                                        partial class Foo
                                        {
                                        partial void Log(string msg)
                                        {
                                        Console.WriteLine(msg);
                                        }
                                        }
                                        #endif

                                        class Program
                                        {
                                            static void Main(string\[\] args)
                                            {
                                                new Foo().DoSomething();
                                            }
                                        }
                                        

                                        }

                                        Latest Article - A Concise Overview of Threads Learning to code with python is like learning to swim with those little arm floaties. It gives you undeserved confidence and will eventually drown you. - DangerBunny Artificial intelligence is the only remedy for natural stupidity. - CDP1802

                                        A Offline
                                        A Offline
                                        agolddog
                                        wrote on last edited by
                                        #43

                                        C'mon Marc, that's not a valid example. Everybody of our age range knows fizzbin has two z's. ;)

                                        1 Reply Last reply
                                        0
                                        • J johannesnestler

                                          No Research needed. It's for extending generated Code that may will be re-generated later (so you can not change it because your changes would be overriden). E.g. I use it to extend EF generated Contexts. It's a very nice feature and .NET has many not everyone will use, so don't. But if you do Frameworks or template-code or big systems (or WindowsForms UI) it's very handy…

                                          O Offline
                                          O Offline
                                          obermd
                                          wrote on last edited by
                                          #44

                                          Finally, a good answer to what Partial Methods are good for.

                                          1 Reply Last reply
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