I'm writing an ABAP program using OO objects. In SE38, under the class folder of my program, some of my local classes do not show up. Some do.
All my classes are stored in an 'include'. As far as I know there's no Class-Builder capability for local classes.
When I rename a class, sometimes it gets renamed in the folder listing mentioned above, sometimes it doesn't.
When I add new classes, sometimes they show up, sometimes they don't.
What am I missing? Is there a particular way to add local classes to an include with other classes and have it show up in the Classes folder? Is there a way to refresh the listings?
Syntax is is being checked, the program finds the classes, so SAP is reading everything and recognizing it just fine. It just doesn't display under the classes folder.
As much as I enjoy OO, I'm starting to get the feeling that although it's the path forward, it's also semi-masochistic. I'm trying to be the leader of our group to encourage OO over classic ABAP. Things like this though, I have to iron out and understand before I could ever convince others. :)
The list of local objects in SE80/SE38 (classes as well as data types, forms and other stuff) isn't refreshed as frequently as one would like. It's not like the Outline view that you might know from Eclipse or similar tools from other IDEs. When in doubt, you might want to right-click the program in the tree view and rebuild the object list. Or you might want to switch to global classes altogether, which gives you a much better tool support.
Related
I have seen Use a single source file for many QtDesigner forms, which is the gist of my question also, - but it simply recommends:
My advice is to use it as Qt way. Use seperate classes and seperate files for each form. This approach is better.
However, I would like to specifically know - is it possible at all to define multiple forms (say, a "Main Window" and a "Dialog with Buttons Bottom") in a single .ui file, and work with them in QtDesigner?
Basically, for an application of mine, I use QtDesigner .ui file to design the MainWindow, and load that from Python (PyQt5) - and it works great. Now, I'd just like to add a window dialog raised on a click of a button, and I'd also like to use QtDesigner for it, but I wouldn't want to maintain two .ui files. I'd imagine, once such an .ui file (with multiple form definitions) would be loaded in Python, the Python code would just set all forms other than QMainWindow to hidden, and then manage when they are shown appropriately.
(I use QtDesigner on and off, so I do not know it very well - however I recall there was some stuff that QtDesigner couldn't do from the UI, but one could do manually in the .ui file, and after such changes, QtDesigner could still deal with them. So, if there is a way to do this - even if it is not fully supported in the QtDesigner UI - I'd love to know about it, or have a definitive answer that it is not doable).
tl;dr
No, you cannot.
Why not?
UI files are intended for individual widgets (it doesn't matter whether they are intended as top level windows or not) and their possible children.
While I can understand your request, it seems more related to a "project" concept than an UI one. That's not the intent of Designer, which cannot imagine the possible extent of your project; and even if that was the case, it wouldn't be very practical: what if your project could potentially have hundreds of windows? Suppose that you have a main window, open your program, but then you decide to close it: your program would be loading hundreds of windows, but use none of them, causing an unnecessary overhead in the program loading.
The concept is similar to the modularization of OOP: not only you just "load" what you actually need, but you also should "split" the project in different files (modules, not unlike python modules) for better maintenance , reusability and overview. What if you want to have two separate "main" UI files for some reason, and, coincidentally, they use a similar dialog? You should copy that dialog every time, and if at some point you forget that step, you might even cause your program to crash as it's trying to access objects that don't exist or have been just slightly renamed.
Furthermore, some interfaces can be really complex, and automatically loading them at startup would be pointless: if you're using the uic module, you're requiring unnecessary parsing of the whole xml tree of the UI, and that would be for every time a new instance for a window from that file is required.
Maybe, someday, developers at Qt will decide to allow "projects" in Designer (which is probably what Qt Creator does, but I've never used it), but ui files will still be individual, as they should.
So, don't worry too much, it's more a question of habit and a slightly annoying aspect: if your project is well conceived, and you also properly name your files, it won't be a major problem and it will have its benefits anyway (even if you don't consider them as you could).
PS: yes, UI files are XML files and can be edited; you could even create/edit an UI file and do things Designer couldn't. But that's just an "unexpected feature" (or smart hack), for which you can never be always sure about the outcome. In future (or just different) versions the parser could be[come] more strict, with the result that your UI becomes completely unusable. That's not unlike editing pyuic files: the programs that use them expect a known behavior (the XML output of Designer), and common, accepted usage. As the recent pyuic file headers (which, I'd like to mark, was added after a personal suggestion of mine) report: "Do not edit this file unless you know what you are doing" ;-)
Here is what I'm looking for:
I'd like to separate pieces of functionality into modules or components of some sort to limit visibility of other classes to prevent that each class has access to every other class which over time results in spaghetti code.
In Java & Eclipse, for example, I would use packages and put each package into a separate project with a clearly defined dependency structure.
Things I have considered:
Using separate folders for source files and using Groups in Xcode:
Pros: simple to do, almost no Xcode configuration needed
Cons: no compile-time separation of functionality, i.e. access to everything is only one #import statement away
Using Frameworks:
Pros: Framework code cannot access access classes outside of framework. This enforces encapsulation and keeps things separate
Cons: Code management is cumbersome if you work on multiple Frameworks at the same time. Each Framework is a separate Xcode project with a separate window
Using Plugins:
Pros: Similar to Frameworks, Plugin code can't access code of other plugins. Clean separation at compile-time. Plugin source can be part of the same Xcode project.
Cons: Not sure. This may be the way to go...
Based on your experience, what would you choose to keep things separate while being able to edit all sources in the same project?
Edit:
I'm targeting Mac OS X
I'm really looking for a solution to enforce separation at compile time
By plugins I mean Cocoa bundles (http://developer.apple.com/library/mac/#documentation/Cocoa/Conceptual/LoadingCode/Concepts/Plugins.html)
I have worked on some good-sized Mac projects (>2M SLOC in my last one in 90 xcodeproj files) and here are my thoughts on managing them:
Avoid dynamic loads like Frameworks, Bundles, or dylibs unless you are actually sharing the binaries between groups. These tend to create more complexity than they solve in my experience. Plus they don't port easily to iOS, which means maintaining multiple approaches. Worst, having lots of dynamic libraries increases the likelihood of including the same symbols twice, leading to all kinds of crazy bugs. This happens when you directly include some "helper" class directly in more than one library. If it includes a global variable, the bugs are awesome as different threads use different instances of the global.
Static libraries are the best choice in many if not most cases. They resolve everything at build time, allowing code stripping in your C/C++ and other optimizations not possible in dynamic libraries. They get rid of "hey, it loads on my system but not the customer's" (when you use the wrong value for the framework path). No need to deal with slides when computing line numbers from crash stacks. They catch duplicate symbols at build time, saving many hours of debugging pain.
Separate major components into separate xcodeproj. Really think about what "major" means here, though. My 90-project product was way too many. Just doing dependency checking can become a very non-trivial exercise. (Xcode 4 can improve this, but I left the project before we ever were able to get Xcode 4 to reliably build it, so I don't know how well it did in the end.)
Separate public from private headers. You can do this with static libs just as well as you can with Frameworks. Put the public headers in a different directory. I recommend each component have its own public include directory for this purpose.
Do not copy headers. Include them directly from the public include directory for the component. Copying headers into a shared tree seems like a great idea until you do it. Then you find that you're editing the copy rather than the real one, or you're editing the real one, but not actually copying it. In any case, it makes development a headache.
Use xcconfig files, not the build pane. The build pane will drive you crazy in these kinds of big projects. Mine tend to have lines like this:
common="../../common"
foo="$(common)/foo"
HEADER_SEARCH_PATHS = $(inherited) $(foo)/include
Within your public header path, include your own bundle name. In the example above, the path to the main header would be common/foo/include/foo/foo.h. The extra level seems a pain, but it's a real win when you import. You then always import like this: #import <foo/foo.h>. Keeps everything very clean. Don't use double-quotes to import public headers. Only use double-quotes to import private headers in your own component.
I haven't decided the best way for Xcode 4, but in Xcode 3, you should always link your own static libraries by adding the project as a subproject and dragging the ".a" target into your link step. Doing it this way ensures that you'll link the one built for the current platform and configuration. My really huge projects haven't been able to convert to Xcode 4 yet, so I don't have a strong opinion yet on the best way there.
Avoid searching for custom libraries (the -L and -l flags at the link step). If you build the library as part of the project, then use the advice above. If you pre-build it, then add the full path in LD_FLAGS. Searching for libraries includes some surprising algorithms and makes the whole thing hard to understand. Never drop a pre-built library into your link step. If you drop a pre-built libssl.a into your link step, it actually adds a -L parameter for the path and then adds -lssl. Under default search rules, even though you show libssl.a in your build pane, you'll actually link to the system libssl.so. Deleting the library will remove the -l but not the -L so you can wind up with bizarre search paths. (I hate the build pane.) Do it this way instead in xcconfig:
LD_FLAGS = "$(openssl)/lib/libssl.a"
If you have stable code that is shared between several projects, and while developing those projects you're never going to mess with this code (and don't want the source code available), then a Framework can be a reasonable approach. If you need plugins to avoid loading large amounts of unnecessary code (and you really won't load that code in most cases), then bundles may be reasonable. But in the majority of cases for application developers, one large executable linked together from static libraries is the best approach IMO. Shared libraries and frameworks only make sense if they're actually shared at runtime.
My suggestion would be:
Use Frameworks. They're the most easily reusable build artifact of the options you list, and the way you describe the structure of what you are trying to achieve sounds very much like creating a set of Frameworks.
Use a separate project for each Framework. You'll never be able to get the compiler to enforce the kind of access restrictions you want if everything is dumped into a single project. And if you can't get the compiler to enforce it, then good luck getting your developers to do so.
Upgrade to XCode4 (if you haven't already). This will allow you to work on multiple projects in a single window (pretty much like how Eclipse does it), without intermingling the projects. This pretty much eliminates the cons you listed under the Frameworks option.
And if you are targeting iOS, I very strongly recommend that you build real frameworks as opposed to the fake ones that you get by using the bundle-hack method, if you aren't building real frameworks already.
I've managed to keep my sanity working on my project which has grown over the past months to fairly large (number of classes) by forcing myself to practice Model-View-Control (MVC) diligently, plus a healthy amount of comments, and the indispensable source control (subversion, then git).
In general, I observe the following:
"Model" Classes that serialize data (doesn't matter from where, and including app's 'state') in an Objective-C 1 class subclassed from NSObject or custom "model" classes that inherits from NSObject. I chose Objective-C 1.0 more for compatibility as it's the lowest common denominator and I didn't want to be stuck in the future writing "model" classes from scratch because of dependency of Objective-C 2.0 features.
View Classes are in XIB with the XIB version set to support the oldest toolchain I need to support (so I can use a previous version Xode 3 in addition to Xcode 4). I tend to start with Apple provided Cocoa Touch API and frameworks to benefit from any optimization/enhancement Apple may introduce as these APIs evolve.
Controller Classes contain usual code that manages display/animation of views (programmatically as well as from XIBs) and data serialization of data from "model" classes.
If I find myself reusing a class a few times, I'd explore refactoring the code and optimizing (measured using Instruments) into what I call "utility" classes, or as protocols.
Hope this helps, and good luck.
This depends largely on your situation and your own specific preferences.
If you're coding "proper" object-oriented classes then you will have a class structure with methods and variables hidden from other classes where necessary. Unless your project is huge and built of hundreds of different distinguishable modules then its probably sufficient to just group classes and resources into folders/groups in XCode and work with it that way.
If you've really got a huuge project with easily distinguishable modules then by all means create a framework. I would suggest though that this would only really be necessary where you are using the same code in different applications, in which case creating a framework/extra project would be a good way to effectively copy code between projects. In practically all other cases it would probably just be overkill and much more complicated than needed.
Your last idea seems to be a mix of the first two. Plugins (as I understand you are describing - tell me if I'm wrong) are just separated classes in the same project? This is probably the best way, and should be done (to an extent) in any case. If you are creating functionality to draw graphs (for example) you should section off a new folder/group and start your classes and functionality within that, only including those classes into your main application where necessary.
Let me put it this way. There's no reason to go over the top... but, even if just for your own sanity - or the maintainability of your code - you should always endeavour to group everything up into descriptive groups/folders.
I'm investigating how to implement use case extension points in DOORS requirements. To this end, I wanted to know if a DOORS object in one module can reference or link to a DOORS object in a second module. If so, I figure I can have my use cases with the extension points in a high level module, then I can have extension variations in a separate DOORS module, with each one referencing the DOORS object with the extension point it is instantiating. Any thoughts on that?
You can definitely link an object in one DOORS module to another. That's one of the main features of DOORS so that you can track your requirements between modules. For example systems level statement of work type documents may be your initial source of requirements, kept in a high level module, and then that can be linked bidirectionally with finer grained software requirements, and then can be further linked to software components or lines of code or test cases.
If you right click a requirement you should see the "Link" option I believe it's called. I think you need to have both modules open, or it at least makes it easier.
You can only link from one object to another. The objects can be in different modules.
Sometimes we wanted to link to a whole module. We created a first "title" object in the module we wanted to link to, and we linked to that.
DOORS is really dismal. Glad we ditched it.
As suggested by the Eclipse documentation, I have an org.eclipse.core.resources.IncrementalProjectBuilder that compiles each source file and separately I also have a org.eclipse.ui.editors.text.TextEditor that can edit each source file. Each source file is compiled into its own compilation unit, but it can reference types from other (already compiled) source files.
Two tasks for which this is important are:
Compiling (to make sure the types we're using actually exist)
Autocomplete (to look up the type so we can see what properties/methods are present on it)
To accomplish this, I want to store a representation of all the compiled types in memory (referred to below as my "type store").
My question is two fold:
Task one above is performed by the builder and task two by the editor. So that they both have access to this type store, should I create a static store somewhere that they both can have access to, or does Eclipse provide a neater way to deal with this problem? Note that it is eclipse, not me, that instantiates the builders and editors when they are needed.
When opening eclipse, I don't want to have to rebuild the whole project just so I can re-populate my type store. My best solution so far is to persist this data somewhere and then repopulate my store from that (perhaps upon project open). Is this how other incremental compilers typically do this? I believe Java's approach is to use a special parser that efficiently extracts this data from the class files.
Any insights would be really appreciated. This is my first DSL.
This is an interesting question and one that doesn't have a simple solution. I'll try to describe a potential solution and also describe in a little bit more detail how JDT accomplishes incremental compilation.
First, a bit about JDT:
Yes, JDT does read class files for some of its information, but only for libraries that don't have source code. And this information is really only used for editing assistance (content assist, navigation, etc).
JDT computes incremental compilation by keeping track of dependencies between compilation units as they are compiled. This state information is stored on disk and retrieved and updated after each compile.
As a more complete example, let's say that after a full build, JDT determines that A.java depends on B.java, which depends on C.java.
If there is a structural change in C.java (a structural change is a change that can affect outside files (e.g., adding/removing a non-private field or method)), then B.java will be recompiled. A.java will not be recompiled since there was no structural change in B.java.
After this bit of clarification on how JDT works, here are some possible answers to your questions:
Yes. This must be done through statically accessible global objects. JDT does this through the JavaCore and JavaModelManager objects. If you don't want to use global singletons, then you can access to your type store available through your plugin's Bundle activator instance. The e4 project does allow dependency injection, which is probably even better (but is not really a part of the core Eclipse APIs).
I think persisting the information on the file system is your best bet. The only real way to determine incremental compile dependencies is to do a full build, so you need to persist the information somewhere. Again, this is how JDT does it. The information is stored in your workspaces' .metadata directory somewhere in the org.eclipse.core.resources plugin. You can have a look at the org.eclipse.jdt.internal.core.builder.State class to see the implementation.
So, this may not be the answer you are looking for, but I think this is the most promising way to approach your problem.
Suppose I am working on exposing some of my server-side classes to a GWT application, but certain parts could be done much better using GWT-specific components (like JSNI, for instance).
What are some techniques for doing so without being too hacky?
For instance, I am aware of using a subpackage and using the <super-source/> tag, but this requires the package names to be different, which causes eclipse to complain. The general solution in the community is to then tell eclipse to use that as a source folder, but then eclipse complains about there being two classes with the same name.
Ideally, there would just be a way to keep everything in a single source tree, and actually have different classes which apply the alternate implementations. This would feel like a more OO approach.
I would like to add a suffix to a class like _gwt which accomplishes this automatically, and I know I could write a script to do this kind of transformation, but that is a kludge for sure.
I've been considering using Google's GIN/GUICE libraries for my projects in general, and I think there might be some kind of a solution there, but I am not sure as I have not thoroughly investigated it.
What are some solutions you have tried in the past on GWT projects?
The easiest way to have split implementations is to use super-source code, but only enough to instantiate a uniquely-named instance or dispatch to a different method. Ideally, the super-source implementation is just a few lines long, and not so bad that you can't roll it by hand.
To work around the Eclipse / javac double-mapping and package name issues, the GWT source uses two top-level roots for user code: user/src and user/super. For example, the AutoBeans package has a split-implementation of JSON quoting and evaluation, one for the JVM and one for the browser.
There's really no non-kludgy way to implement super-source, as this is a feature way outside what you can specify in the language. There's nothing that lets you say "use this implementation in this environment" without the use of some external tool.