I have created a system, within which I am instancing kinematic bodies (2D). These have scripts attached. When I call the functions within these, all is GENERALLY okay. However randomly, with wildly different wait times for it to happen (sometimes it never does), the system will crash, saying that the function, that has been working fine, is does not exist within Area2D. I have no clue why this can happen, can anyone give me any help with this.
The actual error code Invalid call. Nonexistent function 'move' in base 'Area2D'
Thanks
Add check for method existence before you call method.
Let's say you call move method for obj variable (replace it with your own).
Now call to the move method should look like this:
if obj.has_method("move"):
obj.move()
Docs
Related
I am thoroughly stumped by this problem. I have some standard functions that I saved in a compiled AppleScript file, let's call it functions.scpt. In another script, I use load script to load a script object to functions.scpt:
set funcs to load script "path/to/functions.scpt
I have one handler in functions.scpt called icon(). For whatever reason, if I try to call this function more than once in my other script, I get an error. Here's some quick example code:
--called once
funcs's icon()
--called twice
funcs' icon()
Whenever I do this, I get the following error: error "«script» doesn’t understand the “icon” message." number -1708 from «script» to «class icon».
Why can't I call the same function from a loaded script object twice? How can I fix this? I need to call it multiple times.
Thank you to #CRGreen and #jweaks. I actually just found the answer on this thread: https://stackoverflow.com/a/13256042/2884386
I had set a variable icon within the handler, which was overwriting the handler. So when the other script tried to access it the second time, it wasn't pointing to the handler, but to the variable. I rewrote the internal variables, and that fixed it.
So, this is (as an example) correct:
on icon()
set _icon to "path/to/icon.png"
return POSIX file _icon
end icon
Whereas this is incorrect:
on icon()
set icon to "path/to/icon.png
return POSIX file icon
end icon
I am a junior rails developer and was advised to use Class.find(id) to query the database instead of Class.find_by_id(id) which I previously had. The reason I was told is because the former would raise an exception while the latter would return nil. I realize this happens but I am wondering what the high level conceptual logic is for doing it this way. Why do I want the exception? Is this a rails standard where I would always prefer a method that returns an exception as opposed to nil?
You typically want the exception because you're typically doing Foo.find(id) based on data input coming from the user, such as clicking on a link.
For example, you show the user a list of items. There are links like this:
http://example.com/items/100
http://example.com/items/101
http://example.com/items/102
The user clicks the first link, and expects to see item 100.
Your code does this:
Item.find(100)
You expect to find the item, because app created the item link. You'd be surprised if the item didn't exist.
(Corner case surprises are possible: perhaps the item was deleted, or perhaps a hacker is sending in missing ids, etc. Using exceptions helps you handle this as an exceptional circumstance.)
Exceptions are preferred to nil for this, because you want the code to fail immediately so you don't accidentally send the nil on to some other method.
Ruby nil objects can be confusing because they evaluate to falsey and also because nil.id == 4 because of how Ruby uses C. Error messages show up like "Warning: Object#id will be deprecated" or "undefined method for 4:Fixnum".
Nils are problematic as a return type in Ruby in general. There's a great (paid) screencast by Gary Bernhardt that explains why you want to avoid returning nil from methods, but in a nutshell: when a method returns nil, and that nil gets passed up through a chain of method calls and something goes wrong somewhere, it can be extremely difficult to figure out where the actual problem occurred.
Say, for example, you have something like this:
foo_model = MyModel.find_by_name('foo')
# some more lines of code
do_something(foo_model)
and a method:
def do_something(model)
# some stuff stuff
some_other_method(model)
end
Now, if MyModel.find_by_name('foo') returns nil, that nil will be carried along without any errors until it actually has to do something. Say, in some_other_method, you actually try to call something on model, say model.save, you will get an error:
undefined method 'save' for nil:NilClass (NoMethodError)
The trace will carry you back up the method calls, but it will not mention the line that was actually problematic, where you assign MyModel.find_by_name('foo') (which evaluates to nil) to foo_model.
You can imagine that in a real application, the code can be much more complex, and returning nil can make it much more difficult to figure out the source of an error.
An exception, in contrast, tells you immediately where the problem is, and the trace will go back to the line where it occurred. That's one reason (there are others, I imagine) why in general, returning nil is not a good idea.
Hope that helps.
In QTP is there any way in the code to check to see if a specific object exists in the object repository. I have tried the following code:
If JavaWindow(className).JavaDialog(dialogName).Exist Then
doThisStuff
Else
doThisStuffInstead
End If
But from what I have gleamed from the Internets, this is similar to a isVisible method, only resulting in true if the specified object is currently visible. When I use the above code I receive a "JavaDialog object was not found in the Object Repository." Is there a method or any way to prevent this very error and check to see if the object does indeed exist?
Thank you for your time
I'm not sure what you're trying to accomplish here, one typically knows if an object exists in the object repository before using it. The doubt is usually whether there is a corresponding control in the AUT (Application Under Test).
If you really face the situation that sometimes the object is in the repository and sometimes it isn't (I can think of several ways for this to happen but none of them make much sense) then you can use VBScript's error handling mechanism.
On Error Resume Next ' Turn off error handling
' Just check if object is in repository, there's no need to do anything with it
Dim Exists: Exists=JavaWindow(className).JavaDialog(dialogName).Exist
If Err.Number <> 0 Then
doThisStuff 'Exists is still empty
Else
doThisStuffInstead ' Exists is properly set
End If
On Error Goto 0 ' Resume regular error handling
So, from the error you get, either the dialog that appears is different from the one you've stored in the repository or you don't have it there.
Have you checked it is really present in the Repository? You can try to just locate this element button.
Using the method of "if object not in the repository - skip the step" is not really a good idea. 1. Why would you want to skip the test/part of the test if the object was not saved in the repository?
2. If it's not there, so you need to make sure to store it.
I would assume that this "missing" object might have some values by which it's matched to the object from the repository different from test to test. You can tune the "matching" mechanism by manually setting the values by which you want QTP to locate it.
Each time I add in the correct code, it gives me the same error due to AboutMethods:0x00000101841a28 number changing each time. It's like its stuck and I don't know how to get out this loop. It worked once, then I went on to the next step, but then it triggered an error after that.
I must not be inputting the correct line of code given from the console?
def test_calling_private_methods_with_an_explicit_receiver
exception = assert_raise(NoMethodError) do
self.my_private_method
end
assert_match "private method `my_private_method' called for #<AboutMethods:0x000001008debf8>", exception.message
end
The AboutMethods:0x000001008debf8 changes each time, not sure how to approach this problem?
AboutMethods:0x... is the output of the inspect method, which usually (and in this case) includes the class name (AboutMethods) and the object id (0x...). The object id is related to the objects location in memory, so it will change every time.
In my experience, there is very little value to checking the string from an exception (it's brittle). However, if you feel the need, use a regex:
assert_match /private method `my_private_method' called for \#\<AboutMethods:.*/
I'm dealing with a SOAP webservice call from a server that is expecting to receive method calls with the paramaters in the format of:
<urn:offeringId> 354 </urn:offeringId>
But SOAP::RPC::Driver is generating messages in the form of:
<offeringId xsi:type = "xsd:int">354</offeringId>
The server keeps erroring when it gets these messages (especially since it's expecting offeringId to be a custom type internal to itself, not an int).
Is there anyway to configure the driver to format things the way the server is expecting it. Is the server even doing SOAP? I'm having trouble finding reference to that style of formating for SOAP (I know it DOES work though, because SOAPUI works just fine with that type of message).
-Jenny
Edit: I've got at least part of it solved. the RPC::Driver (obviously) uses the RPC standard, whereas apparently the server I'm trying to talk to is doing "document". Now, when I look at RPC::Driver's API, I'm seeing a method named "add_document_method". That SOUNDS to me like it might be what I want, but I can't figure out what paramaters to give it. The examples I've seen around the net don't make much sense to me, things like:
def GetNamePair(response)
response.account.each do |x|
class << x
attr :configuration, true
end
x.configuration = Hash[*x.a.map do |y|
[y.__xmlattr[XSD::QName.new(nil, 'n')], String.new(y)]
end.flatten]
end
end
mNS = 'urn:zimbraAdmin'
drv.add_document_method('GetAllAdminAccountsRequest', mNS, [XSD::QName.new(mNS, 'GetAllAdminAccountsRequest')],
[XSD::QName.new(mNS, 'GetAllAdminAccountsResponse')] )
puts YAML.dump(GetNamePair(drv.GetAllAdminAccountsRequest([]))
All I really know is that I have a method that takes in certain parameters.... I really don't get why, if this method does what I think it does, it has to be more complicated. Isn't this just a matter of taking the exact same data and formating it differently? I'm so confused....
Okay, what I ended up doing was using SOAP:RPC:Drivers add_document_method, which requires me to give it the wsdl, namespace, etc, and then give it the attributes later as a single input hash thingy (and gives me the output in a similar format). It worked, it just wasn't as clean as add_rpc_method (which is waht add_method defaults to)
-Jenny