Do you remember the times when C++ was the mainstream programming language in enterprise level projects ?
\nA popular approach was to simplify the code by defining a lot of macros.
\nEven Microsoft did that very extensively in their MFC implementation for instance in their ubiquitous messagemaps.
\nThe benefit was an easy progamming model – just add a few macros and be happy.
\nOn the other hand it was very difficult to understand what really happened in the background.
\nThis was especially true for user defined macros which could only be used in the context of a certain project.<\/p>\n
Later languages like Java and C# took over and macros became history (C# has a preprocessor but no macros). The nightmare was over.
\nTodays software systems aren’t easier than in the past. Therefore the language engineers considered it to be a good idea to support some metainformation facility in form of attributed programming.<\/p>\n
In .NET you have attributes.<\/p>\n
Java introduces the Language metadata facility (JSR175) which is currently a community draft. This approach is based on javadoc comments. <\/p>\n Looks somehow similar, right ?<\/p>\n But it’s not.<\/p>\n In .NET the attributes are stored in the assemblies metadata and therefore can be accessed at runtime. \t[Cool()] \t[AttributeUsage(AttributeTargets.All)] In Java they merely serve to generate code at compile time. What’s the conclusion ?<\/p>\n On one hand both approaches are very useful to simplify the programming model for the developer.<\/p>\n On the other hand they are like C++ macros. A developer can define his\/her own attributes which nobody outside a project might know. Do you remember the times when C++ was the mainstream programming language in enterprise level projects ? A popular approach was to simplify the code by defining a lot of macros. Even Microsoft did that very extensively in their MFC implementation for instance in their ubiquitous messagemaps. The benefit was an easy progamming model – … Continue reading Attributes – The New Macros ?<\/span><\/a><\/p>\n","protected":false},"author":3,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-12","post","type-post","status-publish","format-standard","hentry","category-uncategorized"],"_links":{"self":[{"href":"https:\/\/www.pleus.net\/blog\/index.php?rest_route=\/wp\/v2\/posts\/12","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.pleus.net\/blog\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.pleus.net\/blog\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.pleus.net\/blog\/index.php?rest_route=\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/www.pleus.net\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=12"}],"version-history":[{"count":1,"href":"https:\/\/www.pleus.net\/blog\/index.php?rest_route=\/wp\/v2\/posts\/12\/revisions"}],"predecessor-version":[{"id":375,"href":"https:\/\/www.pleus.net\/blog\/index.php?rest_route=\/wp\/v2\/posts\/12\/revisions\/375"}],"wp:attachment":[{"href":"https:\/\/www.pleus.net\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=12"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.pleus.net\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=12"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.pleus.net\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=12"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}
\n[WebMethod]
\npublic string HelloWorld()
\n{
\n return “Hello, .World!”;
\n}
\n<\/font><\/p>\n
\n\/**
\n * @common:operation
\n *\/
\npublic String HelloWorld()
\n{
\n return “Hello, World!”;
\n}
\n<\/font><\/p>\n
\nThey can be determined by reflection as shown in the following example:<\/p>\n
\nclass Test
\n{
\n\tstatic void Main(string[] args)
\n\t{
\n Type t = typeof (Test);
\n MemberInfo[] members = t.GetMember(“DoIt”);
\n object[] attrs = members[0].GetCustomAttributes(false);
\n Console.WriteLine(attrs[0].ToString());
\n \t}<\/p>\n
\n public static void DoIt()
\n {
\n\t}<\/p>\n
\n public class CoolAttribute : Attribute
\n {
\n }
\n}
\n<\/font><\/p>\n
\nJava supports reflection as well. But due to the fact that the attributes are not stored in the metadata they can’t be determined by reflection at runtime. <\/p>\n
\nThis leads to applications which are hard to maintain.
\nIn order to create maintainable software systems I think developers should define their own attributes\/annotations as little as possible.
\nThis will ease the job especially for new team members which join a project at a later time.<\/p>\n","protected":false},"excerpt":{"rendered":"