Could you help me in the process of creating Unit Test case for Scala in IntelliJ?
I tried creating it using intention action but it did not come for me. I checked the settings also for intention. All looks fine to me.
Do we have different process for Scala or am I missing something?
I think if you right click on a name (class, method, etc.) and select 'go to/test' (which i think is bound to Ctrl-Shift-T in the default keymap), it will offer to create a missing test.
Related
I have a routes file like this:
GET /getOf/:city/:fi/:state/:zipCode cont.Offer.getOf(city:String, fi:String, state:String, zipCode:String)
In my scala class, my code is like this:
def getOf(city:String, fi:String,state:String,zipCode:String) = Action(parse.anyContent) {request =>
val offer = Offer(city,fi,state,zipCode);
Ok(Json.toJson(offerService.getOffer(offer)));
}
But when I run I get this compilation error:
too many arguments for method apply: (name: String, constraint: String)play.core.DynamicPart in object DynamicPart
But same code works fine if I have only one argument. I even not understanding what's the problem. Yes, I have created Eclipse project with play clean-all and others. But still same problem persists.
Can anyone please guide me on this? As I am very new to Play framework and scala.
i got the same problem when i walk through from the below url http://scala-ide.org/docs/tutorials/play/index.html but the issue resolved by calling clean and then compile from play console solved the issue.
Note* i initially had the site at different folder.
I got this error only in eclipse IDE and if i make any changes to the views it compiled atonce whereas for controllers it check only when "RELOAD" works...till then you may see the error at eclipse ide but app works fine.
I have a use case where I need to create a class based on user input.
For example, the user input could be : "(Int,fieldname1) : (String,fieldname2) : .. etc"
Then a class has to be created as follows at runtime
Class Some
{
Int fieldname1
String fieldname2
..so..on..
}
Is this something that Scala supports? Any help is really appreciated.
Your scenario doesn't seem to make sense. It's not so much an issue of runtime instantiation (the JVM can certainly do this with reflection). Really, what you're asking is to dynamically generate a class, which is only useful if your code makes use of it later on. But how can your code make use of it later on if you don't know what it looks like? For example, how would your later code know which fields it could reference?
No, not really.
The idea of a class is to define a type that can be checked at compile time. You see, creating it at runtime would somewhat contradict that.
You might want to store the user input in a different way, e.g. a map.
What are you trying to achieve by creating a class at runtime?
I think this makes sense, as long as you are using your "data model" in a generic manner.
Will this approach work here? Depends.
If your data coming from a file that is read at runtime but available at compile time, then you're in luck and type-safety will be maintained. In fact, you will have two options.
Split your project into two:
In the first run, read the file and write the new source
programmatically (as Strings, or better, with Treehugger).
In the second run, compile your generated class with the rest of your project and use it normally.
If #1 is too "manual", then use Macro Annotations. The idea here is that the main sub-project's compile time follows the macro sub-project's runtime. Therefore, if we provide the main sub-project with an "empty" class, members can be added to it dynamically at compile time using data that the macro sees at runtime. - To get started, Modify the macro to read from a file in this example
Else, if you're data are truly only knowable at runtime, then #Rob Starling's suggestion may work for you as it did me. I'll share my attempt if you want to be a guinea pig. For debugging, I've got an App.scala in there that shows how to pass strings to a runtime class generator and access it at runtime with Java reflection, even define a Scala type alias with it. So the question is, will your new dynamic class serve as a type-parameter in Slick, or fail to, as it sometimes does with other libraries?
I am repeatedly run into a similar problem with Scala IDE. Thanks to tab completion Scala IDE proposes several methods. However, always when I choose a method it complains that it cannot resolve it. In the screenshot, I select the method findByEan from models.Product. After selecting the proposed method I get an error message:
Multiple markers at this line
- Line breakpoint:Products [line: 16] - show
- value findByEan is not a member of object models.Product
It complains that .findByEan() is not part of models.Product. As you can see from the listing above - the Product object has this method. Of course, it even proposed it to me several seconds ago!
package models
case class Product(ean:Long, name:String, description:String)
object Product{
var products = Set() // some products ...
def find_all = products.toList.sortBy(_.ean)
def findByEan(ean:Long) = products.find(_.ean == ean)
A similar issue happens when I add template views to the controllers.
Why Scala IDE cannot compile the proposed methods?
Scala IDE Version: 3.0.2-vfinal-20131028-1923-Typesafe
About not being able to find details. From its fully qualified name, it seems be a Play template.
The Play templates are compiled by Play itself, they are only typed checked inside the template editor. For them to be listed in completion, they have to be compiled (done by refreshing the app in the web browser), and visible by Scala IDE (done by refreshing the project in the IDE).
It is also possible to setup an environment in a way that the compile+refresh is done automatically. The steps are described in this tutorial.
I have an assignment to code several methods in Scala. The methods will be encapsulated in an object that has no main method. The professor gave us a JAR file that contains an interface (my object implements this interface) as well as a sort of pseudo test object that performs various assert statements against each of my functions. This object also does not contain a main method.
Now in Intellij I simply had to declare the dependency on the JAR in the classpath, and it runs fine. Eclipse is giving me trouble though because when I go to define a Scala application run configuration it specifically asks me to name the class that contains a main method, and there is no main method.
I am assuming that I might be choosing the wrong project type for this type of set up, but I am inexperienced with this and I would appreciate any advice you might have for running something like this in eclipse.
Thanks.
I would either:
just write an object with a main method which calls the test object, or
start a Scala interpreter in your project (from context menu, under Scala).
Preferring the first approach, because it's faster to repeat tests after a modification.
I searched the web for how to enforce srictfp in Scala but could not find any hint of it. There are some people complaining about it, but real solutions cannot be found. There is a bugtracker entry about it which is almost two years old. As it seems there is no elegant fix for it on the way I'm looking for workarounds.
My current idea is to set the appropiate method flag ACC_STRICT in the generated bytecode by myself somehow but I have no idea what would be the best solution to do so. A Scala Compiler Plugin comes to mind or just hacking flags in a hex editor. Maybe someone faced the same challenge and can tell me his or her solution?
You could add a post-processor in your build process that would add the strictfp modifier to the generated class (i.e. setting the ACC_STRICT flag as you say).
You can implement such a post-processor using Javassist for example. This could look like this:
CtClass clazz = ClassPool.getDefault().makeClass(
new FileInputStream("old/HelloWorld.class"));
CtMethod method = clazz.getDeclaredMethod("testMethod");
method.setModifiers(method.getModifiers() | Modifier.STRICT);
clazz.detach();
clazz.toBytecode(new DataOutputStream(new FileOutputStream(
"new/HelloWorld.class")));
You would then have to find a way to configure which classes/method need to be modified this way.
Scala has a strictfp annotation now:
#strictfp
def f() = …