ViewModelLocator was not found in UWP / WinIot Core - unit-testing

App1
I have an UWP App which uses a ViewModelLocator class (No MVVMLight or Prism).
The ViewModelLocator is integrated as resource in the App.xml and used in the DataContext of the View.
Running this app in Release and Debug mode works fine.
UnitTestApp1
I have a UnitTest App which references the App1 from above.
When running the UnitTests with Release mode, then all tests run.
When I run the UnitTests in Debug mode, then I get the error:
Cannot deserialize XBF metadata type list as 'ViewModelLocator' was not found in namespace 'App1.UI'. [Line: 0 Position: 0]
This problem is available since Fall Creator as minimal target version.
I was reading the in UWP the ResourceDictionaries do not have any code behind and are not initialzed directly. Can this be related to that?

#Schaf,
The ViewModel needs to be able to access the actual model. You have all of them them being initialized before any data is available for them. That's not how they are intended to be used.
The Model-View-ViewModel construct is meant to allow an aggregation of different data points to present a specific set of information, AND be testable at the same time. In Debug mode, the Resources are not used, because that is essentially a set of static objects (images, lists that don't change, etc.) that are called on at actual runtime.
Additionally, in your scenario, it sounds like your data access is integrated into the ViewModel itself. Testing in Debug mode is supposed to be White-Box, to ensure that the flow, and transformation, of data is easily accessible from beginning to end. By default, this requires that the classes under test (the ViewModels in this case) must be accessible directly from the Test Harness, and thus must be able to be instantiated apart from the overall application context (where the application resources live), which isn't fully assembled in Debug mode.
So to answer your question, yes the inability to test your ViewModels in Debug mode is directly related to them being underneath the ResourceDictionary. If you pull your ViewModels out into their own folder in the solution, at the same level as your model, you should be able to reach them in Debug mode, and test not only the data access but that the information that is populating each ViewModel is the correct set of information, to satisfy the Business rules that you are trying to meet.

Related

Get the name of the unit test class in the ios host application

I am using the standard XCTestCase class to implement and trigger the unit tests together with the host ios application.
Is it possible to pass a piece of information from the unit test (XCTestCase subclass) to the host application, and read this information in host's main.m?
XCUIApplication().launchArguments does not work for me. Also putting a value in the build settings is not a solution.
I need to change the behaviour of the host application according to the XCTestCase's subclasses.
The class under the test (subclass of XCTestCase) is affected by the host's App Delegate class. I would like to instantiate a special AppDelegateFake class (in main.m) that will not affect the class under test.
It is possible to detect if the host app is running with a unit test set and instantiate a special fake test app delegate class:
https://marcosantadev.com/fake-appdelegate-unit-testing-swift/
BUT in that way I have to use this fake app delegate for ALL tests (XCTestCase's).
Something like this if that would be nice to have in the host app:
let isRunningTests = NSClassFromString("XCTestCaseSubclassXY") != nil
but unfortunately, this is not possible. I also tried to get somehow the instance of XCTestConfiguration, which contains the running XCTestCase name, but again it is not possible.
Thanks.
I normally include a TestingAppDelegate with my tests. When unit tests run, they are injected into the running app before launch. So the production code can check for the existence of TestingAppDelegate and decide which app delegate to use.
With my use case of having a single replacement app delegate, I do the following in main.swift:
let appDelegateClass: AnyClass =
NSClassFromString("TestingAppDelegate") ?? AppDelegate.self
This searches for a class with the given name, and uses it if present. Otherwise, it falls back to the regular production code AppDelegate. Then I use this to start the app:
UIApplicationMain(
CommandLine.argc,
CommandLine.unsafeArgv,
nil,
NSStringFromClass(appDelegateClass)
)
But this technique doesn't work for apps that use Scene Delegates to launch because scenes are cached between launches.
I can't imagine why you'd want more than one app delegate for tests. If it's to configure different settings at launch, I'd specify these settings at the Scheme level in the Test section, Arguments tab, "Arguments Passed at Launch". TestingAppDelegate can then read those arguments from UserDefaults.
In principle, it is not possible, what I have asked for. For the unit testing, there is a single instance of the running host app. On the other hand for the UI tests, there is every time a dedicated app instance loaded - and configurable with XCUIApplication().launchArguments

Persistence of data for MSI installation

The MSI installation would call my (native/C++) custom action functions. Since the DLL is freshly loaded, and the MSIEXEC.EXE process is launched separately for each function (the callable actions, as specified in MSI/WiX script), I cannot use any global data in C/C++ program.
How (or Where) can I store some information about the installation going on?
I cannot use named objects (like shared-memory) as the "process" that launches the DLL to call the "action" function would exit, and OS will not keep the named-object.
I may use an external file to store, but then how would I know (in the DLL's function):
When to delete the external file.
When to find that this function call is the first call (Action/function call Before="LaunchConditions" may help, not very sure).
If I cannot delete the file, I cannot know if "information" is current or stale (i.e. belonging to earlier failed/succeeded MSI run).
"Temporary MSI tables" I have heard of, but not sure how to utilize it.
Preserve Settings: I am a little confused what your custom actions do, to be honest. However, it sounds like they preserve settings from an older application and setup version and put them back in place if the MSI fails to install properly?
Migration Suggestion (please seriously consider this option): Could you install your new MSI package and delete all shortcuts and access to the old application whilst leaving it
installed instead? Your new application version installs to a new path
and a new registry hive, and then you migrate all settings on first
launch of the new application and then kick off the uninstall of the
old application - somehow - or just leave it installed if that is
acceptable? Are there COM servers in your old install? Other things that have global registration?
Custom Action Abstinence: The above is just a suggestion to avoid custom actions. There are many reasons to avoid custom actions (propaganda piece against custom actions). If you migrate settings on application launch you avoid all sequencing, conditioning, impersonation issues along with the technical issues you have already faced (there are many more) associated with custom action use. And crucially you are in a familiar debugging context (application launch code) as opposed to the unfamiliar world of setups and their poor debugability.
Preserving Settings & Data: With regards to saving data and settings in a running MSI instance, the built in mechanism is basically to set properties using Session.Property (COM / VBScript) or MsiSetProperty (Win32) calls. This allows you to preserve strings inside the MSI's Session object. Sort of global data.
Note that properties can only be set in immediate mode (custom actions that don't change the system), and sending the data to deferred mode custom actions (that can make system changes) is quite involved centering around the CustomActionData concept (more on deferred mode & CustomActionData).
Essentially you send a string to the deferred mode custom action by means of a SetProperty custom action in immediate mode. Typically a "home grown" delimited string that you construct in immediate mode and chew up into information pieces when receiving it in deferred mode. You could try to use JSON-strings and similar to make transfer easier and more reliable by serializing and de-serializing objects via JSON strings.
Alternatives?: This set property approach is involved. Some people write to and from the registry during installation, or to a temp file (in the temp folder) and then they clean up during the commit phase of MSI, but I don't like this approach for several reasons. For one thing commit custom actions might not run based on policies on target systems (when rollback is disabled, no commit script is created - see "Commit Execution" section), and it isn't best practice. Adding temporary rows is an interesting option that I have never spent much time on. I doubt you would be able to easily use this to achieve what you need, although I don't really know what you need in detail. I haven't used it properly. Quick sample. This RemoveFile example from WiX might be better.

How to register multiple Audio Units at runtime (similar to VST plugin shell)?

I just started coding VST plugins. But since I'm on a mac I would also like to build Audio Units. I managed to compile some sample code and these components showed up inside my Logic DAW.
In VST there's the possibility to create a plugin shell. This describes a single 'dll'/'vst' file which has multiple effects in it. During startup the host calls a function called getNextShellPlugin and the plugin dynamically registers its content at runtime. The effects then perfectly show up in a plugin list.
Is there a similar way I can achieve this with Audio Units?
I managed to get a plugin shell by adding another component description to the 'info.plist'. But I have to hardcode every effect in there and that's not what I want.
I also tried to use AudioComponentRegister but this didn't work properly for me. Since therefore the component has to be instanciated so I can call this function inside the constructor. But to list the components inside Logic they need to be found during the scan where the component will not get instanciated by default.
So the goal is to register multiple effects inside 1 component at runtime.
Does someone maybe have a tip or a solution? Thanks a lot!

Possible to make QML application "offline capable" using caches?

I'm trying to make one of my QML apps "offline capable" - that means I want users to be able to use the application when not connected to the internet.
The main problem I'm seeing is the fact that I'm pretty much pulling a QML file with the UI from one of my HTTP servers, allowing me to keep the bulk of the code within reach and easily updatable.
My "main QML file" obviously has external dependencies, such as fonts (using FontLoader), images (using Image) and other QML components (using Loader).
AFAIK all those resources are loaded through the Qt networking stack, so I'm wondering what I'll have to do to make all resources available when offline without having to download them all manually to the device.
Is it possible to do this by tweaking existing/implementing my own cache at Qt/C++ level or am I totally on the wrong track?
Thanks!
A simple solution is to invert the approach: include baseline files within your application's executable/bundle. Upon first startup, copy them to the application's data directory. Then, whenever you have access to your server, you can update the data directory.
All modifications of the data directory should be atomic - they must either completely succeed, or completely fail, without leaving the data directory in an unusable state.
Typically, you'd create a new, temporary data folder, and copy/hardlink the files there, and download what's needed, and only once everything checks out you'd swap the old data directory with the new one.
Letting your application access QML and similar resources directly online is pretty much impossible to get right, unless you insist on explicitly versioning all the resources and having the version numbers in the url.
Suppose your application was started, and has loaded some resources. There are no guarantees that the user has went to all the QML screens - thus only some resources will be loaded. QML also makes no guarantees as to how often and when will the resources be reloaded: it maintains its own caches, after all. Sometime then you update the contents on the server. The user proceeds to explore more of the application after you've done the changes, but now the application he experiences is a frankenstein of older and newer pieces, with no guarantees that these pieces are still meant to work together. It's a bad idea.

MFC add Typelib or ActiveX for OPOS

So at work I have been working for a few months on a OPOS driver for a few different things. I didn't create the project, but I have taken it over and am the only one developing it. So today I got curious about the way that it was done and I think that it may have started off on the wrong foot. I had to do a little bit of digging to find out that it uses the OPOS drivers from a company called MCS (Monroe Consulting Services) I downloaded 1.13 and installed the MSI version. I fired up VS created a new mfc dll. I then went to add a class. This is where I am confused.
It doesn't matter if i choose Typelib or ActiveX it usually gives me the same list of interfaces that I can add/extend from(with one exception that comes to mind with MSR it has an events interface that I can extend) And they both make the same header file (in the case with msr it is COPOSMSR.h) but one extends CCmdTarget, and the other extends CWnd. This is my first question. Which should I choose? what is a typelib/ what is a ActiveX component and how do they differ from one another.
The one i've been working on extends CCmdTarget. For the life of me I can not figure out how the driver knows to use one of the files (USNMSRRFID) but that is where all the development went into. (I broke it up a bit so it wasn't just one huge file) But that file doesn't extend COPOSMSR..it extends CCmdTarget as well. The only time i see anything mention the USN file is in MSRRFID.idl (which confuses me even more) Any one have clarity for this?
Part of me thinks this could make a very big impact when it comes time to deploy. A few of the test apps that have been written that make use of this driver require a somewhat confusing setup process that involves registering different drivers, copying files into a specific folder, setting up the registry and so forth. I think that if i can get a grip on what this all means and how to make a nice application that extends one of these OPOS devices properly that I could save my self further grief in the future.
Any tips or pointers??? Sorry if it is a newb question..but i am new to C++. I started with Java then moved to C# so some of this stuff is WAY over my head....
Well so I've done TONS of digging, and it is like searching for dinosaurs. Not easy, and hard to find. I will end up writing a nice little how to on this, but for now I will put up my findings. Although I still don't have this 100% i know I am close.
Turns out the typelib and activeX things are not a big concern but come into play after you've gotten started. ActiveX is for Control objects, and Typelib is for the Service Object. The most important thing is to get started correctly. I found a article on some Chinese website that offers some OK tips after figuring out the translation errors. To start with you will want to make a C++ project with Automation. It can be ATL or MFC. My preference is MFC. In the UPOS 1.13 pdf (or newer) in Appendix A section 8 it describes the responsibilities of the Service object. It has the main methods you need to implement. There are 16 methods you have to add, and at least 4 methods that get/set the properties for your OPOS device.
So to get started you will need to open up the add class wizard (for MFC classes) and click Add MFC class. You wil want your base class to be CCmdTarget. Come up with a classy Class name (I chose PinpadSOCPP) Then in the automation radio buttons select Creatable by type ID. It should fill in your type id as [Project Name].[Class name] so mine was PinpadSO.PinpadSOCPP. hit finish. This makes a nice interface file that you can use Class view to add methods and so forth to it.
As for adding the methods there are 2 things to note about this, and one of them I haven't figured out 100% yet. The first is that you have to implement all the methods in that section with the correct parameters and return values. Most of them return LONG (32bit signed number). and the 2 most common parameters are LONG and BSTR. (there is the occasional pointers for when you have "out" parameters) This is the part that I think that I am currently failing as I don't know if I have them all implemented correctly and that is why I am getting error 104/305 (which from the Chinese article says that I am missing something from my methods) I'm not sure if it is case sensitive, and I'm not sure of the 7 properties that look to need to have get/set which ones need to be implemented because the MSR SO that i am working on from work doesn't use them all and that SO is working. The other is that after you implement the base OPOS methods you have to also implement the extra methods from your specific OPOS device. Since I am doing PINPad there are 6 additional methods I have to implement.
Now this is a lot of time consuming work because you have to open up class view, navigate to the name of your project class. Expand it and go to the Interface portion. My Project name is PinpadSO, and the file that I am implementing this in is PinpadSOCPP (which means the interface name is IPinpadSOCPP) right click on IPinpadSOCPP and click add > add method. This brings you to a 2 step process. You fill in your return value, name of your function, add in all your parameters. Hit next and fill out some help string info (if you want) and hit finish. Now after you do that 20+ times it gets old and slow...and if you are like me you type Computer instead of Compute and flip flop letters, or forget to hit add on all your parameters. A person could make a nice little program to edit the 3 files that get changed each time you add a method and that would speed it up considerably. If you make a mistake you will need to open up [project name].idl, [class name].h, and [class name].cpp those are the 3 files that get the methods added to it directly. I recommend not making a mistake.
so now that all that hard work is out of the way. Compile your program. If you want to save your self an extra step you could turn on Auto Register in the linker project settings (NOTE: if you do that you'll need to run Visual Studio as admin if you program in vista or higher) this would save you of having to open a command window (admin) navigate to your DLL and use the command regsvr32 on that DLL. Nice thing is that you don't have to do that over and over again, just the once will do. I have no hard facts that it works like that every time but the MSR SO that I am working on, I'll make changes to it, compile it, then open up my OPOS tester program and the changes have taken affect.
After that you need to make your registry additions. navigate to HKLM\software\OLEforRetail\ServiceOPOS
(NOTE if you have a x64 machine you'll do this twice. One there, and again at HKLM\software\Wow6432Node\OLEforRetail\ServiceOPOS )
You'll need to add a Key for whatever OPOS device you are working with. I am making a pinpad SO so I made a Key called PINPad (check your UPOS document to see what name you should give it) Lastly choose a name for your device. I chose the model type of the from the vendor as my device name (C100) and made a sub key in PINPad. The default REG_SZ value needs to be your registered SO Device TypeID. in my case it is PinpadSO.PinpadSOCPP
if you don't have a OPOS test program (which I just made my own as a console program) then you can use the Microsoft OPOS test app (I couldn't get it to work on my x64 machine...but maybe you'll have better luck with it) If you do decide to make your own OPOS test app make sure you compile it for x86 machines (even if you have x64) OPOS does not like x64 for some reason (probably the pointers length I'd assume)..at any rate. Once you got it all setup run your test app (for my case I am just running OPOSPinpadClass pin = new OPOSPinpadClass(); Console.WriteLine(pin.Open("C100")); and hope for 0 :)
I am currently getting 104 (E_NOSERVICE)..and like i said before i think it is because I don't have all my methods correct. If that turns out to be the case I'll edit this response, or I'll report back and say what it really was.
Anywho, i hope this helps anyone else who decides they want to make their own SO. Good luck
UPDATE
OPOS checks a couple of properties when you call the Open command. One of the properties that is a must to implement is the in the GetPropertyNumber, and it is PIDX_ServiceObjectVersion. You will need to set this number to return (1000000 * majorVersion) + (1000 * minorVersion) + revision since I am making a OPOS 1.13 compatible SO my returned ServiceObjectVersion is 1013000. You will also want to implement 3 properties in GetPropertyString:
PIDX_DeviceDescription
PIDX_DeviceName
PIDX_ServiceObjectDescription
For all other values you can return a empty string or 0 until you start hooking all those things up.
As a side note if you don't want to make it in C++ you don't have to. You can make it in any language that you can write a ActiveX object in (such as a COM visible .NET class library)