First of, here is a little bit of a background story. I am using the Game Engine Stencyl (the interface can be compared to Scratch) to teach basic gamedevelopment with. Unfortunately, since this is a rather small team, I am still missing a couple of useful build in functions, thus I decided to create my own extensions for it. I know my way around C#, Java and UnityScript, but these extensions will have to be written in Haxe. I've already tried a couple of days of finding my answers on their API page, but that is way beyond my level of experience.
The first issue is that I am simply trying to use a couple of map functions, but the methods are all static. Everytime I try to use a function like mapCount() in line 16, it will throw me an error saying: Cannot access controls in static function. So far I have managed to figure out that this is because I am not able to call non-static functions from a static method, but I have no idea how to tackle this (and probably more issues like this in the future).
The second issue is that when I un-comment line 14, and comment out line 16, the game will compile just fine, but will crash with an stackoverflow error. The arguments for this function are: createRecycledActor(actorType, x, y, layerPosition)
Here is the current state of my script, not doing a lot right now, but I'm taking babysteps to learn my way around this new language. If you require any more info, just let me know!
Ps, the trace function in line 15 works fine btw.
import com.stencyl.behavior.Script;
import com.stencyl.behavior.Script.*;
import com.stencyl.utils.Utils;
import com.stencyl.models.Actor;
import com.stencyl.models.actor.ActorType;
class MobileGameKit
{
public var controls:Map<String,Actor> = new Map();
public static function CreateThumbstick(mActorType:ActorType, mLocation:Int, mDirectionLock:Int)
{
//createRecycledActor(mActorType, 0, 0, Script.FRONT);
trace("created thumbstick at position: "+mLocation+" with directionlock: "+mDirectionLock);
trace("items in control map: " + Utils.mapCount(controls));
}
}
Because controls is a member variable. i.e. each class instance has its own controls.
While a static function is a function at class level. i.e. each class (among all instances) has only one copy of the function.
So in a static function, you cannot access member variables because it won't be able to know from which instance to look for that member.
To solve your problem, either make controls a static var, or pass the member controls as a parameter to your static function.
btw, the language has been officially named as Haxe (instead haXe) for years already.
Related
I started working with CodedUI few months before to automate a desktop Application(WPF).
Just checking out for the best ways to create a framework for my Application.
As, I have seen in other automation tools, I feel the heart of an automation framework using any tool(UI Based) is the way it's object Repository is created i.e. how well the UI objects are defined. A Cleaner and well defined Object Repository always proves to be very helpful when it comes to updating your tests.
I am trying to discover the best way to store my UIObjects so that in case of any UI changes in my Application, I have to put minimum effort to update my automation test.
Also, If an Object changes in application, updating it only at one place should solve the problem.
This can be any kind of change like :
->change in just a property(This I feel would be very easy to update in automation Test. The best and Easiet way I feel is to simply update the .uitest file(the xml file) if possible.)
->change in hierarchy and position
->entirely new object added
For the 2nd and 3rd changes, updating scripts become a difficult job, esp if the UIObject is being referred at may places, in many TestMethods, or Modules.
Also, I have generally seen that in Test Methods, Variable Declarations are done to create a reference to the UIMap objects and those variables are further used in the TestMethod Code.
So, in this case If the UI of my application changes, I will have to update the variable decalaration in each of the Test Methods. I want to reduce this effort to changing the variable decalaration only at one place. OfCourse, I cannot have all the code inside only one Test Method. One way that came to my mind is as:
Can't I have simply one common place for all these Variable decalarations. We can give a unique and understandable name to each UIObject e.g.: The decalratoions will look like:
UITabPage UITabPage = this.UIMap.UISimWindow.UISelectEquipmentTabList.UITabPage;
WpfRow UIRow = this.UIMap.UISimWindow.UISelectEquipmentTabList.UITabPage.UIEquipmentDetailsTable.UIRow;
WpfText UIEquipmentTagText = this.UIMap.UISimWindow.UISelectEquipmentTabList.UITabPage.UIEquipmentDetailsTable.UIRow.UITagCell.UIEquipmentTagText;
WpfCheckBox UIEquipmentCheckBox = this.UIMap.UISimWindow.UISelectEquipmentTabList.UITabPage.UIEquipmentDetailsTable.UIRow.UICheckBoxCell.UICheckBox;
....
....
and use these variables wherever required. Hence, In case of any chnages also, there will be only one place where you will need to update thse objects.
But for this, These varaibles must be made STATIC. What can be problem with making these Object Variables static?
Please provide your suggestion on this topic. May be what I am thinking is not possible or practical. I just want to choose the best way to start with before I go too far with the automation scripts and realize later that my approach wasn't a good one.
Thanks in Advance,
Shruti
Look into using descriptive programming instead of using the UIMaps.
Make a static class with generic functions to assist. Going to give you some examples of how to set it up.
For example:
public WinWindow parentwin(string ParentControlName)
{
var parentwin = new WinWindow();
parentwin.SearchProperties.Add("Control Name", ParentControlName);
return parentwin;
}
public WinWindow childwin(string ChildWinControlName, string ParentControlName)
{
var childwin = new WinWindow(parentwin(ParentControlName));
childwin.SearchProperties.Add("Control Name", ChildWinControlName);
return childwin;
}
public WinButton button(string ButtonName,string ChildWinControlName, string ParentControlName)
{
var childwin = childwin(ChildWinControlName,ParentControlName);
var button = new WinButton(childwin);
button.SearchProperties.Add("Name", ButtonName);
}
public void ClickButton(string ButtonName,string ChildWinControlName, string ParentControlName)
{
var button = button(ButtonName,ChildWinControlName,ParentControlName);
Mouse.Click(button);
}
public void ChangeFocus(WinWindow NewFocus)
{
var NewFocus = new NewFocus();
NewFocus.SetFocus();
}
public void ChangeFocus(WinWindow NewFocusChild, string c)
{
var a = new NewFocus();
a.SetFocus();
}
ChangeFocus(childwin("WelcomeForm", "MainForm");
ClickButton("&OK", "WelcomeForm", "MainForm");
I decided to start a new project to get into hacklang, and after fixing some if the problems I initially ran into transitioning from php habits, I ran into the following errors:
Unbound name: str_replace
Unbound name: empty
Doing some research I found that this is due to using 'legacy' php which isn't typechecked, and will error with //strict.
That's fine and all, empty() was easy enough to replace, however str_replace() is a bit more difficult.
Is there an equivalent function that will work with //strict? Or at least something similar.
I'm aware that I could use //decl but I feel like that defeats the purpose in my case.
Is there at least any way to tell which functions are implemented in hack and which are not in the documentation as I couldn't find one?
For reference (though it isn't too relevant to the question itself), here is the code:
<?hh //strict
class HackMarkdown {
public function parse(string $content) : string {
if($content===null){
throw new RuntimeException('Empty Content');
}
$prepared = $this->prepare($content);
}
private function prepare(string $contentpre) : Vector<string>{
$contentpre = str_replace(array("\r\n","\r"),"\n",$contentpre);
//probably need more in here
$prepared = Vector::fromArray(explode($contentpre,"\n"));
//and here
return $prepared;
}
}
You don't need to change your code at all. You just need to tell the Hack tools about all the inbuilt PHP functions.
The easiest way to do this is to download this folder and put it somewhere in your project. I put it in a hhi folder in the base of my project. The files in there tell Hack about all the inbuilt PHP functions.
Most of them don't have type hints, which can lead to Hack thinking the return type of everything is mixed instead of the actual return, that is actually correct in most cases as, for example, str_replace can return either a string or a bool. However, it does stop the "unbound name" errors, which is the main reason for adding them.
I am wondering if there is a way to ignore certain TypeScript errors upon compilation?
I basically have the same issues most people with large projects have around using the this keyword, and I don't want to put all my classes methods into the constructor.
So I have got an example like so:
TypeScript Example
Which seems to create perfectly valid JS and allows me to get around the this keyword issue, however as you can see in the example the typescript compiler tells me that I cannot compile that code as the keyword this is not valid within that scope. However I don't see why it is an error as it produces okay code.
So is there a way to tell it to ignore certain errors? I am sure given time there will be a nice way to manage the this keyword, but currently I find it pretty dire.
== Edit ==
(Do not read unless you care about context of this question and partial rant)
Just to add some context to all this to show that I'm not just some nut-job (I am sure a lot of you will still think I am) and that I have some good reasons why I want to be able to allow these errors to go through.
Here are some previous questions I have made which highlight some major problems (imo) with TypeScript current this implementation.
Using lawnchair with Typescript
Issue with child scoping of this in Typescript
https://typescript.codeplex.com/discussions/429350 (And some comments I make down the bottom)
The underlying problem I have is that I need to guarantee that all logic is within a consistent scope, I need to be able to access things within knockout, jQuery etc and the local instance of a class. I used to do this with the var self = this; within the class declaration in JavaScript and worked great. As mentioned in some of these previous questions I cannot do that now, so the only way I can guarantee the scope is to use lambda methods, and the only way I can define one of these as a method within a class is within the constructor, and this part is HEAVILY down to personal preference, but I find it horrific that people seem to think that using that syntax is classed as a recommended pattern and not just a work around.
I know TypeScript is in alpha phase and a lot will change, and I HOPE so much that we get some nicer way to deal with this but currently I either make everything a huge mess just to get typescript working (and this is within Hundreds of files which I'm migrating over to TypeScript ) or I just make the call that I know better than the compiler in this case (VERY DANGEROUS I KNOW) so I can keep my code nice and hopefully when a better pattern comes out for handling this I can migrate it then.
Also just on a side note I know a lot of people are loving the fact that TypeScript is embracing and trying to stay as close to the new JavaScript features and known syntax as possible which is great, but typescript is NOT the next version of JavaScript so I don't see a problem with adding some syntactic sugar to the language as people who want to use the latest and greatest official JavaScript implementation can still do so.
The author's specific issue with this seems to be solved but the question is posed about ignoring errors, and for those who end up here looking how to ignore errors:
If properly fixing the error or using more decent workarounds like already suggested here are not an option, as of TypeScript 2.6 (released on Oct 31, 2017), now there is a way to ignore all errors from a specific line using // #ts-ignore comments before the target line.
The mendtioned documentation is succinct enough, but to recap:
// #ts-ignore
const s : string = false
disables error reporting for this line.
However, this should only be used as a last resort when fixing the error or using hacks like (x as any) is much more trouble than losing all type checking for a line.
As for specifying certain errors, the current (mid-2018) state is discussed here, in Design Meeting Notes (2/16/2018) and further comments, which is basically
"no conclusion yet"
and strong opposition to introducing this fine tuning.
I think your question as posed is an XY problem. What you're going for is how can I ensure that some of my class methods are guaranteed to have a correct this context?
For that problem, I would propose this solution:
class LambdaMethods {
constructor(private message: string) {
this.DoSomething = this.DoSomething.bind(this);
}
public DoSomething() {
alert(this.message);
}
}
This has several benefits.
First, you're being explicit about what's going on. Most programmers are probably not going to understand the subtle semantics about what the difference between the member and method syntax are in terms of codegen.
Second, it makes it very clear, from looking at the constructor, which methods are going to have a guaranteed this context. Critically, from a performance, perspective, you don't want to write all your methods this way, just the ones that absolutely need it.
Finally, it preserves the OOP semantics of the class. You'll actually be able to use super.DoSomething from a derived class implementation of DoSomething.
I'm sure you're aware of the standard form of defining a function without the arrow notation. There's another TypeScript expression that generates the exact same code but without the compile error:
class LambdaMethods {
private message: string;
public DoSomething: () => void;
constructor(message: string) {
this.message = message;
this.DoSomething = () => { alert(this.message); };
}
}
So why is this legal and the other one isn't? Well according to the spec: an arrow function expression preserves the this of its enclosing context. So it preserves the meaning of this from the scope it was declared. But declaring a function at the class level this doesn't actually have a meaning.
Here's an example that's wrong for the exact same reason that might be more clear:
class LambdaMethods {
private message: string;
constructor(message: string) {
this.message = message;
}
var a = this.message; // can't do this
}
The way that initializer works by being combined with the constructor is an implementation detail that can't be relied upon. It could change.
I am sure given time there will be a nice way to manage the this keyword, but currently I find it pretty dire.
One of the high-level goals (that I love) in TypeScript is to extend the JavaScript language and work with it, not fight it. How this operates is tricky but worth learning.
I have a question that keeps bothering me. Currently, I have started using Kohana 3.2 Framework. I've written a helper to handle some functionality - I have a number of methods, which are (as it should be) declared STATIC. But, all of these methods are somehow working with the database, so I need to load a model. Currently, every method has a non-static variable like this:
$comment = new Model_Comments;
$comment->addComment("abc");
OK, it seems to be working, but then I wanted to get rid of this redundancy by using class attribute to hold the instance of the model (with is class as well).
Something like this:
private static $comment; // Declaring attribute
self::$comment = new Model_Comment; // This is done within helper __constuct method
self::$comment->addComment("abc"); // And call it within the method.
But, I got failed with: Call to a member function addComment() on a non-object
Question is: is it possible to do it ? Maybe there are some other approaches ?
Sorry for a long story and, thanks in advice! :P
A static method cannot call a non-static method without operating on an instance of the class. So, what you're proposing won't work. There may be a way do accomplish something similar, but what about trying the following:
You could implement the singleton or factory pattern for your "helper" class. Then, you could create the model (as an attribute) as you instantiate/return the instance. With an actual instance of your "helper" class, you won't have to worry about the static scope issues.
In other words, you can create a helper-like class as a "normal" class in your application that, upon creation, always has the necessary model available.
I'd be happy to help further if this approach makes sense.
David
When I enabled code contracts on my WPF control project I ran into a problem with an auto generated file which was created at compile time (XamlNamespace.GeneratedInternalTypeHelper). Note, the generated file is called GeneratedInternalTypeHelper.g.cs and is not the same as the GeneratedInternalTypeHelper.g.i.cs which there are several obsolete blog posts about.
I'm not exactly sure what its purpose is, but I am assuming it is important for some internal reflection to resolve XAML. The problem is that it does not have code contracts, nor is the code contract system smart enough to recognize it as an auto generated file. This leads to a bunch of errors from the static checker.
I tried searching for a solution to this problem, but it seems like nobody is developing WPF controls and using code contracts. I did come across an interesting attribute, ContractVerificationAttribute, which takes a boolean value to set whether the assembly or class is to be verified. This allows you to decorate a class as not verified. Sadly the GeneratedInternalTypeHelper is regenerated with every compile, so it is not possible to exclude just this one class. The inverse scenario is possible though, decorate the assembly as not verified and then opt in for every class.
To mitigate the obvious hack I wanted to create a test that would at least verify that the exposed classes have code contract verification with a test like the following to ensure that own classes were at least being verified:
[Fact]
public void AllAssemblyTypesAreDecoratedWithContractVerificationTrue()
{
var assembly = typeof(someType).Assembly;
var exposedTypes = assembly.GetTypes().Where(t=>!string.IsNullOrWhiteSpace(t.Namespace) && t.Namespace.StartsWith("MyNamespace") && !t.Name.StartsWith("<>"));
var areAnyNotContractVerified = exposedTypes.Any(t =>
{
var verificationAttribute = t.GetCustomAttributes(typeof(ContractVerificationAttribute), true).OfType<ContractVerificationAttribute>();
return verificationAttribute.Any() && verificationAttribute.First().Value;
});
Assert.False(areAnyNotContractVerified);
}
As you can see it takes all classes in the controls assembly and finds the one from the company namespace which are not also auto generated anonymous types (<>WeirdClassName).
(I also need to exclude Resources and settings, but I hope you get the idea).
I'm not loving the solution since there are ways of avoiding contract verification, but currently it's the best I can come up with. If anyone has a better solution, please let me know.
So you can treat this class exactly like you would treat any other "3rd party" class or library. I'm sure certain assumptions would hold with the interaction with this generated class so at the interaction points, decorate your own code with Contract.Assume(result != null) or similar.
var result = new GennedClass().GetSomeValue();
Contract.Assume(result != null);
What this does is translate into an assertion that is checked at run time, but it allows the static analyzer to reason about the rest of the code that you do control.