I have written a few razor helpers and these helpers use functions that include the extension methods generated by T4MVC.
I now want to move these to a control library so that they can be used across multiple mvc applications.
The initial idea that I have used is that I can put a copy of the template into the control library, and this works, the downside is that the template used in the application then regenerates the same extension methods in the same namespace.
Because I am using some of the extension that require the interface for the ActionResult I do need that the namespace remains the same.
What I am wondering is, is there a known way to use the extensions in a control library as well as an application that references the library, or is a change to the template required such that the static extension methods can be either generated or not via a flag in the settings file?
I am also wondering if the static extensions could be included in a separate cs file that lives along side the template. So that we have 2 classes T4Extensions and DynamicT4Extensions?
This might force the use of the interface IT4MVCActionResult though,
This is similar but not quite the same as http://forums.asp.net/p/1510753/3603100.aspx.
I wonder if the solution might be to add a new switch in the settings file that would turn off the generation of those static methods. So if you know you're already getting them from some referenced assembly, you'd turn them off in the app.
Though that might still blow up if you have multiple unrelated libraries that each need to use the methods, as the app would then get an ambiguous reference.
Note that we can't make the methods internal, since some of them need to be called from views, which live in different assemblies.
And ideally, I'd prefer to avoid having those in yet a separate file, as some users may start complaining that T4MVC brings in too many files.
Sorry, not really a clear answer, but more thinking through possibilities. :)
Related
I have a couple third-party libraries (not using cocoapods) in my iOS project, and when I dug into the files of each, I discovered that 4 of these libraries had their own versions of the UIImage+ImageEffects category. So I was about to merge them into one single file, but that got kind of messy:
For instance, one of the libraries, SCLAlertView, has a custom method inside its version of UIImage+ImageEffects which refers back to one of SCLAlertView's classes to access a variable. So if I import that class into the merged file, It would make the new UIImage+ImageEffects dependent on SCLAlertView. I dont feel comfortable about that, and its not pretty. So I need your guys thoughts on this :
What is the best approach to go about this? Should I just go ahead and merge them or keep them as separate files in their respective libraries?
Does having multiple, slightly different, versions of the same category in a project really matter? does it give rise to any issues/conflicts?
i often see this :
Class _NSZombie_OS_dispatch_group is implemented in both ?? and ?? ...
in my console. is this by any chance caused by the above thing?
Thanks in advance.
Note: I didnt give the question a generalized name like "multiple versions of same category in one project" because UIImage+ImageEffects is used by lots of libraries for blur effects and has the most chance of ending up as multiple slightly different versions in your project
Answering 2 will drive the answer to 1 (and 3 sounds like a bug in the system, you should file it :) ):
Does having multiple, slightly different, versions of the same category in a project really matter? does it give rise to any issues/conflicts?
As long as all method names are unique, there isn't a problem outside of the issue that categories on system classes are awful for the long term maintainability of a codebase.
If, however, the categories all have methods of the same name -- which they likely do -- then only one of them will be used and which one is indeterminate.
Thus, yes, you'll need to merge them. Or, better yet, eliminate them entirely by refactoring them into a helper class or something (then file a bug against the original codebase and have 'em pull the changes).
If you build and integrate your 3rd party libs as static libraries, every lib is isolated and uses its own version of the category, and things should work fine. In this case, you should keep the categories internal to the libs and avoid exposing them by means of #include in public headers. EDIT: As pointed out by bbum, category methods are not isolated inside their containing static lib; wrapping the libraries as static libs would not solve the OP's problem.
If you just have one build target and integrate the libs by source, things will work OK as long as the duplicate method implementations don't differ (even though this might result in lots of linker warnings).
Issue will arise if the category implementations differ, because the resulting behavior (i.e. which category method is used at runtime) is undefined (see this post). In this case, I don't know a good solution for the problem; a not good (but working) solution would be to rename (prefix) the methods in each lib's category and use the renamed method in the respective lib. E.g. in lib A, you would rename imageByApplyingLightEffectToImage: to a_imageByApplyingLightEffectToImage: and change all calls to that method inside A accordingly. As I said, I would use this approach as a last resort only.
Im currently working on a iOS project where we now want to add some feature for the Apple Watch. Since the extension for Apple Watch is a different target I naturally can't access the code written for the App. I have searched here on stackoverflow and have found two different ways to solve this problem.
Create a dynamic frameworks. This would definitely be the best approach but unfortunately the app must support down to iOS 6, and what I have found this solution will only work on iOS 8+.
Link the files in either Build Phases -> Compile Sources or through Target Membership in File Inspector. The main problem here is that the two classes we want to use have many dependencies to many other classes, which also have other dependencies and so on. From what I understand I need to include all these other files as well if I want to make use of the classes I intend to use in the extension.
So my question is if there is any other better way for me to accomplish this. If I choose #2, first of all I need to include all files, and after that, from a maintenance point of view, if I make changes to there files, for example importing an other class, I need to include that one as well in Compile Sources / Target Membership. Would really appreciate any ideas or advice regarding this! Thank you!
I don't know how "deep" is your coupling regarding point 2. However if you can use interfaces(protocols) instead of direct class referencing you can separate just the classes you need.
Moreover you could re-think whether specific class really need some other class to operate(probably not) or just some methods from it. Those methods could be moved to protocol and your dependant class to implement it(now this class do not need to be part of AppWatch target).
This will be heavy work though if your project is really big and your classes are tightly coupled. I would advice you to read this article about Dependency Injection and especially 'Dependency is bigger than Testing part' :)
In a brainstorming meeting, someone recommended that we use a static library in a future project. I have researched this topic all day.
I have found some helpful answers about what a static library is and how to create one.
Library? Static? Dynamic? Or Framework? Project inside another project
I've also found answers on how to use resources with a library:
iOS Library With Resources
My Question Is:
Do I really need to create a static library, or should I just create a class for internal-use-only code?
Conditions:
I have three projects that require a special encode and decode engine.
The engine's functions involve cryptography, IP packet transport, and hardware binary coding.
There are fewer than 20 functions.
We will never release this engine to a third party developer or open source it.
Another way to ask:
In what circumstances should I create a static library?
Even if you don't want to share your code with other developers, you can still gain tremendous benefits from creating a static library.
As Srikar Appal mentions, benefits gained from creating a static library are 1) Code Distribution, 2) Code Reuse, and I'd also like to add, 3) Versioning, 4) Testability (kudos to BergQuester's comments below) and 5) Documentation.
Let's look at these more closely:
1) Code Distribution
Static libraries are great because they make it easy to distribute your code- all you have to do is compile and share the resulting .a file.
Even if you never plan to share your code with other developers, you can still make use of this across your own projects.
Alternatively, you might instead include the static library's project as a subproject to your various main projects, making this a dependency of the main project... see https://github.com/jverkoey/iOS-Framework for how this can be setup.
2) Code Reuse
Even in very different apps, you'll often find that you're doing the same task that you'd previously written code for. If you're an efficient developer, you wouldn't want to write the same code again... instead, you'd want to just include your previously written, polished code.
You might say, But I can just include the classes directly.
What if your code isn't necessarily polished, however? Or as tends to happen, the frameworks it uses change over time?
As you make changes and bug fixes to the code set, it'd be nice to be able to easily include the latest version in your projects (or be able to easily update your projects later on). A static library makes this easier to do because all the related code is included within a single package.
There's also no worrying about what other project-specific hacks other developers have been imposed on it - the main project can't (or in the case of a static library included as a subproject, shouldn't) change the static library's code set.
This has the added benefit that if someone does need to change the static library's code set, he must make the change such that all projects relying on it will still be able to use it (no project-specific shortcut hacks).
3) Versioning
If you have a set of classes that are moved around and included project to project, it's hard to keep up with versioning. Most likely, the only versioning you do have is that of the main project.
What if one project fixes some bugs and another project fixes other bugs within this class set? You might not know to merge these changes (what if two teams are working separately even on these)? Or, each project might be fixing the same bugs!
By creating a static library, you can keep track of versioning (the static library's project has its own version number), and by making changes on the static library, you'll have less merge issues and eliminate the risk of fixing the same bugs over and over.
4) Testability
As iOS continues to mature as a platform, unit testing your code is becoming more and more prevalent. Apple even continues to build and expand on testing frameworks (XCTest) to make it easier and faster for iOS developers to write unit tests.
While you could (and, IMHO, should) write unit tests for your code at the application level, creating and encapsulating code withIN static libraries typically makes these tests better and easier to maintain.
The tests are better because well-designed static libraries encapsulate purposeful functionality (i.e. a well-designed library performs a specific task, such as networking tasks for example), which makes it easier to "unit" test the code.
That is, a well-designed static library sets out to accomplish a predefined "purpose", so essentially, it creates test boundaries naturally (i.e. networking and presenting the fetched data would likely be at least two separate libraries).
The tests are easier to maintain because they would be within the same repository (e.g. Git repo) as the static library code (and thereby, versioned and updated alongside this code). Just like you don't really want to copy and paste code from project to project, you similarly don't want to copy and paste tests, either.
5) Documentation
Like unit testing, in-line documentation continues to become more important in iOS.
While you can (and again, IMHO, should) document code at the application level, it's again better and easier to maintain if it's at the static library level (for the same reasoning as unit testing above).
So to answer your question,
Do I really need to create a static library, or should I just create a class for internal-use-only code?
You might ask yourself the following:
Will this code be used across multiple apps?
Will this code ever have more than one class?
Will multiple developers be working on or using this code concurrently (possibly in different apps)?
Will this code be unit tested?
Will this code be documented?
If you answer YES to most of the above, you should probably create a static library for this code. It will likely save you trouble in the long run.
If you answer NO to most of the above, you might not gain much benefit from creating a static library (as the code set would have to be very specific to a project in such an instance).
In my opinion creating a static library has the following benefits -
Code distribution - This is the biggest reason (perhaps the only reason) developers create a static library. It obfuscates the actual code and exposes the API methods. But since you have explicitly mentioned that this "library package" would never be distributed to 3rd party developers this reason might not apply.
Code Reuse - This is the other reason I can think of. But then, one can achieve code reuse by simply using classes in (.m files), having the method definitions in header file & importing the header file (.h files). So this is not much of a reason to create a static library.
I am not aware of any performance benefits due to statically linked code. Also creating static library has its own maintenance overhead. It would not be as simple as creating one build. You would have to keep in mind linking the static library, maintaining compatibility etc.
So in your case creating a static library might not make much sense.
I would like to use a common class file for all the modules. I like to keep all the common variables and arrays in that file.
I had created a folder 'Common' as like as 'Zend' library folder.
And created a class Common.php in that folder.
Afterwards, I initialized use Common/Common in controller;
Created an Object
$common = new Common();
It shown an error.
'Class not found Common\Common'.
How can I do this in ZF2?
It is really suggested you step out of monolithic thoughts with Zend Framework 2. Make modules independent and self-contained. This also means you shouldn't let big all-of-a-kind classes floating around in your application.
If you want to have for example a shared logger instance, make a log module your other modules depend on. Same holds for caching, database connections etc. With me will several others really trying to convince people not to use these kind of strategies.
When you give more insights in why you need a "common" class, perhaps more detailed answers can help you with the architectural decision. Personally I would suggest you to look first at your modular architecture instead of trying to solve this specific problem.
PS. Real answer: probably you have an autoloading issue...
I'm adding some non-trivial functionality in my rails application and it needs to be in a module and not one of the auto generated models. I'd like a few suggestions on where the file containing the module should go (currently I've added a 'code' directory on the same level as 'models' and 'views' - but I don't know that that's a strong choice).
Most people add this type of code in lib
If it's related to the controller/view layer, consider putting the functionality in a helper. If not, lib is a good general storage directory for util classes and the like. If at all possible, think about making extra code like this a plugin, as it helps keep the codebase clean and reusable functionality available to other projects.