I inserted this line into my init() of my BootStrap class
Integer.metaClass.minutes = { 60000L * delegate }
I was then not able to use it from a Job class (Quartz plugin). Do I put this line of code somewhere else to make it a global modification?
I was also wondering the best way to make a function available inside all classes in Grails.
Like a global function. Would it be to extend the Object metaclass? or is there a better way?
Do I put this line of code somewhere else to make it a global modification?
Use the DelegatingMetaClass
I was also wondering the best way to make a function available inside all classes in Grails. Like a global function. Would it be to extend the Object metaclass? or is there a better way?
If you want the function to be an instance method of all classes, then you must add it to the metaClass of Object (see above). If not, simply add the function as a static method of a class, i.e. the same way you make functions globally accessible in Java.
Related
I'm writing test cases using XCTest framework provided by apple. I come up with situation where i want to mock local variables allocated inside the function like this below
-(void)myFunction{
A* a = [[A alloc] init];
}
from my testcase class i want to mock class A inside my function testMyFunction . Is there any way to do it without using OCMock.
If it's okay to create the instance first, then inject it using normal Dependency Injection techniques.
But if you need to ensure that the instance won't be created until it's needed, you have a few choices:
Inject a class, as #dasdom says. Then call its initializer when you need it.
Inject a block that acts as a Factory. Call it when you need it.
For more complex initialization: inject a Factory. I'd typically make this conform to a protocol, to make replacements clear.
You could inject the class to be used in the method into the system unter test. In the test you can use a different class.
Suppose I want my class to do things on attribute access. I can of course do that in setters and getters:
class Foo {
set bar (v) {
// do stuff
}
}
However, if I want to attach the same behavior to multiple attributes, I'd have to explicitly define the same setters and getters for every one of them. (The use case I have in mind is an observable, i.e. a class that knows when its attributes are being changed).
What I'd like to do is something like:
class Foo {
var bar = new AttributeWithAccessBehavior();
}
Python does this with descriptors - what is the closest thing in Dart?
AFAIK there isn't anything with getter/setter syntax that you can reuse.
You could assign a function to a field, that you can access using call notation (), but you have to be careful to call the function instead of overriding the field assignment.
A similar but more powerful alternative are classes that can emulate functions (see https://www.dartlang.org/articles/emulating-functions/)
A class that has a call method can be used like a method.
This is similar to assigned functions mentioned above but in addition you can store state information.
If you implement actual getter/setter you can of course delegate to whatever you want, but that is obviously not what you are looking for.
For the use case you mentioned, there is the observe package.
I have no idea how exactly it solves the problem, but it works quite well.
How do I replace methods of an existing java class (GrailsDataBinder in my case).
I read that method calls for java classes doesnt go through invokeMethod, and hence it doesn't work, but I think there would be some solution.
I just tried this
GrailsDataBinder.metaClass.static.createBinder = {Object target, String objectName ->
throw new RuntimeException()
}
And this
GrailsDataBinder.class.metaClass.static.createBinder = {Object target, String
objectName -> throw new RuntimeException()
}
But that did not seem to have replaced the method, as my closure isn't being invoked, but instead the original method executes.
update
I just found that the closure is being executed if I call the createBinder from the test class itself - so it works and method is replaced
void testDataBinder() {
GrailsDataBinder.createBinder(null, null)
}
However When it is invoked from DataBindingUtils, it always executes original method (DataBindingUtils is also a java class)
Following is the code inside DataBindingUtils that invokes the method.
binder = GrailsDataBinder.createBinder(object, object.getClass().getName());
Note : There are some similar questions asked earlier, but none of them have worked for me.
This is disappointing once you see the power of Groovy. However, as you already know, many of the cool metaclass etc. features available in Groovy simply don't work as you would like on Java classes.
If you are trying to override, stub or mock stuff on a Java class for unit testing etc., I advise looking into Spock, because it uses 'magic' that actually works on Java classes also.
If you are try to override methods for some other reason, you should try extending the Java class with a Groovy class or 'wrapping' the Java class with a Groovy class to gain the metaclass features you want when external classes call you classes methods. Unfortunately this still won't allow you to intercept calls that the Java class makes to itself.
I am attempting to add some string utility methods to the String class by utilizing Groovy's metaclass functionality. Right now I have something like this in my init closure in my BootStrap.groovy script:
String.metaClass.upper = {
delegate.toUpperCase()
}
The problem is that this upper method is only available within the scope of the BootStrap...trying to use it anywhere else in the Grails app does not work and I get method missing errors.
Is there any way to make those methods available everywhere?
Does this happen in both testing and running contexts? There is a bug where all metaClass changes get rolled back after each unit test: http://jira.grails.org/browse/GRAILS-8596
i want to overwrite a method of
symfony/lib/plugins/sfDoctrinePlugin/lib/form/sfFormDoctrine.class.php.
I think a good way could be writing again the method in the form class
where i need that method.
In that case if i need that method in other form class should i write
again the new method, so i would break the rule DRY...
So is there any better way?
Regards
Javi
You should be using BaseFormDoctrine if this is a Doctrine specific method or BaseForm if you want the method to apply to all forms. These form classes are provided specifically for this purpose.
Piggybacking on Colonel Sponz's answer, I've done this many times by extending the class I want to override. By extending the class, you don't have to duplicate anything. In the method(s) you want to customize, just add your customized code and then call parent::method_name() to execute the same method of the super class. You get all the benefits of both. Calls to methods that don't exist in the subclass will execute against the super class.
It should be noted that this strategy is basic OOP stuff and isn't limited to Symfony or even PHP.
You could create a new class that inherits from sfFormDoctrine that redeclares the methods you need and then use your new class in place of sfFormDoctrine wherever you need that method.