I'm coming across some strange MEF behaviour in Prism, which I can't really explain. I've found a way around it that I'm not too happy with, so I'd really like to understand what's causing it.
I've declared my shell window class with a PartCreationPolicy of NonShared. And I'm trying to use the CompositionContainer.GetExportedValue<>() function from my MefBootstrapper to create a new instance of the Shell.
The strange thing is, if I call Container.GetExportedValue<>() before the shell has been created, I get a new object of type Shell, each time I call it. However, once the shell has been initialized, repeated calls to Container.GetExportedValue<>() return the same instance of the Shell.
It's as if the shell initialization somehow re-registers my Shell export as a Shared.
However, I don't see any calls in the bootstrapper code that explicitly try to achieve this.
Can anyone explain:
what action has this side effect
How (if possible) to restore the NonShared behaviour, so I can create multiple shells using MEF/ServiceLocator.
Cheers,
Mark
I'm not sure how Prism uses MEF, but here's a theory: How is the shell being created in normal startup? My guess is that it is not by calling GetExportedValue from the MEF container, but rather by calling the constructor for the Shell and then adding it to the container via ComposeParts() or using a CompositionBatch. A part added directly to the container in that way would override what was available in the catalog, and the CreationPolicy wouldn't apply either (because MEF isn't creating that part).
here is a answer for your multiple shell question. you have to check if the NonShared behavior is answered there.
Related
I've been trying a solution for this, but. I cannot find it.
What I'm trying to do, is work with the "bind by reference" ability, but working with ILE RPG written with embedded sql.
I can use the BNDDIR ctl opt in my source. And everything works correctly.
But that means a "bind by copy" method. Checked deleting the SRVPGM and even the BINDDIR. And the caller program still works.
So, is there any way to use "bind by reference" in an ILERPGSQL program?
After my question, an example:
Program SNILOG is a module, that conains several procedures. Part of them, exported.
In QSRVSRC I set the exported procedures, with a source with the same name: SNILOG. Something like this:
STRPGMEXP PGMLVL(*CURRENT)
/************************************************** ******************/
/* *MODULE SNILOG INIGREDI 04/10/21 15:25:30 */
/************************************************** ******************/
EXPORT SYMBOL("GETDIAG_TOSTRING")
EXPORT SYMBOL("GETDIAGNOSTICS")
EXPORT SYMBOL("GRABAR_LOG")
EXPORT SYMBOL("SNILOG")
ENDPGMEXP
As part of the procedures are programmed with embedded sql, the compilation must be done with CRTSQLRPGI, using the parameter OBJTYPE(*SRVPGM).
So, I finally get a SRVPGM called SNILOG, with those 4 procedures exported.
Once I've got the SRVPGM, I add it to a BNDDIR called SNI_BNDDIR.
Ok, let's go to the caller program: SNI600V.
Defined with
dftactgrp(*no)
, of course!.
And compiled with CRTSQLRPGI and parameter OBJTYPE(*PGM).
Here, if I use the control spec
bnddir('SNI_BNDDIR')
, it works fine.
But not fine enough, as this is a "bind by copy" method (I can delete the SRVPGM or the BNDDIR, and it is still working fine).
When I'm not working with SQL, I can use the CRTPGM command, and I can set the BNDSRVPGM parameter, to set the SRVPGM the program is going to be called. Well, just their procedures...
But I cannot find any similar option in CRTSQLRPGI command.
Nor in opt codes in ctl-opt sentence (We have BNDDIR, but not BNDSRVPGM option).
Any idea?
I'm running V7R3M0 with TR level: 6
Thanks in advance!
the use of
bnddir('SNI_BNDDIR')
Is the way to bind by reference OR bind by copy.
The key is what does your BNDDIR look like?
If you want to bind by reference, then it should include *SRVPGM objects.
If you want to bind by copy, then it should include *MODULE objects.
Generally, you want a *BNDDIR for every *SRVPGM that includes the modules (and maybe a utility *SRVPGM or two) needed for building a specific *SRVPGM.
Then one or more *BNDDIR that includes just *SRVPGM objects that are used to build the programs that use those *SRVPGMs.
I'm interested in using the qlot library from inside of a Lisp image to manage multiple local instances of quicklisp.
There doesn't seem to be any documentation on how to use it, except through a non-Lisp CLI interface, and the obvious
(qlot:with-local-quicklisp (#P"/a/path/here/") (qlot:install :skippy))
or
(qlot:with-local-quicklisp (#P"/a/path/here/") (qlot:quickload :skippy))
give me
Component "skippy" not found
[Condition of type ASDF/FIND-SYSTEM:MISSING-COMPONENT]
What I'm looking for is a way to install a particular library by name. Basically, exactly how one would use ql:quickload, but targeting a specific, local directory instead of ~/quicklisp. What am I doing wrong?
It looks like the intent is to modify dynamically scoped variables in a way that makes using ql:quickload directly possible.
So
(qlot:with-local-quicklisp (#P"/a/path/to/some/quicklisp/")
(qlot/util:with-package-functions :ql (quickload)
(quickload :skippy)))
will result in skippy being installed in the quicklisp instance at #P"/a/path/to/some/quicklisp/" instead of the default location.
This leaves me a bit perplexed as to what qlot:quickload is for; its describe output doesn't shed additional light.
I have a bunch of fixture stuff that I want to do once for the test class but I also don't want the associated tests messing with it.
I don't really get the py.test fixture system yet so I'm not seeing how this is supposed to be done.
In vanilla Django this stuff is achieved with setUpTestData which lets you create some fixtures in the DB once for the test class. Then at the start of each test case it drops a transaction savepoint and at the end of each test it resets to that save point. (This is in addition to it transactioning around the entire class so as to leave a clean db at the end.)
I could get this functionality by inheriting off Django's TransactionTestCase but pytest-django seems to want to run without that and I've achieved everything else I need without doing so.
I've looked around for this quite a lot, and the best I could find is this pytest plugin, which I have not tested myself:
https://github.com/tipsi/pytest-tipsi-django
Per the pytest-django issue list, it looks like this has been raised before, but there is no movement towards a fix:
https://github.com/pytest-dev/pytest-django/issues/514
I have a Command bound to my MainWindow via CommandBinding to the Delete key.
I want that, depending on the context (which element is active), the same command would be translated to different delete commands that semantically delete things.
In few words, I want that pressing the Delete key will delete things depending on where the focus is at that moment.
I have heard about CompositeCommands (PRISM), but I don't know whether that is useful an easily applicable here.
Thanks a lot!
CompositeCommand in Prism helps you register several commands in one, so that all can be called at the same time.
Since you use MVVM, you should have a ViewModel for each kind of object at least. If you have something like a ViewModelBase or an IViewModel, you could simply add a command to it, and initialize it differently in each ViewModel.
I have a modular Sinatra app without a DB and in order to test memcache, I have some test files that need to be created and deleted on the file system. I would like to generate these files in an AfterConfiguration hook using some helper methods (which are in a module shared with rspec, which also needs to create/delete these files for testing). I only want to create them once at the start of Cucumber.
I do not seem to be able to access the helpers from within AfterConfiguration, which lives in "support/hooks.rb." The helpers are accessible from Cucumber's steps, so I know they have been loaded properly.
This previous post seems to have an answer: Want to load seed data before running cucumber
The second example in this answer seems to say my modules should be accessible to my AfterConfiguration block, but I get "undefined method `foo' for nil:NilClass" when attempting to call helper method "foo".
I can pull everything out into a rakefile and run it that way, but I'd like to know what I'm missing here.
After digging around in the code, it appears that AfterConfiguration not only runs before any features are loaded, but before World is instantiated. Running self.class inside of the AfterConfig block returns NilClass. Running self.class inside of any other hook, such as a Before, will return MyWorldName. In retrospect, this makes sense as every feature is run in a separate instance of World.
This is why helpers defined as instance methods (ie def method_name) are unknown. Changing my methods to module methods (ie def ModuleName.method_name) allows them to function, since they really are module methods anyway.