QtScript Questions

[Scorp2us]

I am embarking on some QtScript stuff and have some questions:

1) Can I include files? I seem to be able to use eval() however if I provide a function include(filename) {..} in the script I run into the problem that the functions will only be accessible from within the function and not added to the root context.

2) I am trying to use animations, and spefically QPropertyAnimation(item, property, parent) however my custom properties do not seem to work. I am using a JS-defined class, with properties as this.opacity, and passing "opacity" in the constructor. What does it take to have QPropertyAnimation be able to use JS-defined properties?

Thanks.

[wysota]

I am embarking on some QtScript stuff and have some questions:

1) Can I include files? I seem to be able to use eval() however if I provide a function include(filename) {..} in the script I run into the problem that the functions will only be accessible from within the function and not added to the root context.

Can we see the exact code?

[Scorp2us]

qs> eval("function f(i){return i*3;}");
qs> b=f(5);
15

qs> eval("function f(i){return i*3;}");
qs> b=f(5);
15

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qs> function a(i) { eval("function F(i) {return i*3;}"); }
qs> a
function a(i) {
    eval("function F(i) {return i*3;}");
}
qs> a();
qs> F(6);
ReferenceError: F is not defined

qs> function a(i) { eval("function F(i) {return i*3;}"); }
qs> a
function a(i) {
    eval("function F(i) {return i*3;}");
}
qs> a();
qs> F(6);
ReferenceError: F is not defined

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qs> function b() { eval("function F(i) {return i*3;}"); return F(4); }
qs> b()
12

qs> function b() { eval("function F(i) {return i*3;}"); return F(4); }
qs> b()
12

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[wysota]

Your eval() (in the a() function) creates its own scope, whatever you assign there will not go to the global scope.

[Scorp2us]

Your eval() (in the a() function) creates its own scope, whatever you assign there will not go to the global scope.

Exactly! (I knew this). But is there a way around that? Like a special context that I can specify (like a Python Module __main__) ?

[wysota]

I think you have to look on JavaScript forums for that but the question is why are you trying to define a global function from eval(). You can do that from C++ code if you want... Also you can name the global object somehow in the C++ code and then you can access it from JavaScript code and assign the function to it - it should then be globally available. You can also return the function from the eval code and assign it to the global namespace in the parent (also JavaScript) code.

[Scorp2us]

I was hoping to do all this in JS, but it looks like I can't.

Thanks.

[wysota]

If you return a function object from the eval() call then you can do everything in JavaScript.

F = eval("return function(){ return 7; }");
x = F();

F = eval("return function(){ return 7; }");
x = F();

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[Scorp2us]

Yeah, but that eval is in the global context.

I still can't have a function defining a global function.

[wysota]

Your a() function can return the result of eval().

function a(){ return eval("return function(){ return 7 }") }
F = a()

function a(){ return eval("return function(){ return 7 }") }
F = a()

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But I would try something like this:

globalObj = this // global context
function a() { eval("globalObj.F = function(){ return 7; }") }
a()
F()

globalObj = this // global context
function a() { eval("globalObj.F = function(){ return 7; }") }
a()
F()

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