Animate CC HTML5 Canvas: Fire function on frame access?

[jeffery wright]

I have a function that resets the position of a MC, that does not do what I expect:

function reset_mark() {
this.mark.x = 1200;
this.mark.y = -15;
}

Which I call from various frames via:

reset_mark();

I have also tried:

this.reset_mark();

MovieClip(root).reset_mark();

this.MovieClip(root).reset_mark();

But none seem to work... am I missing something painfully obvious? I wouldn't be surprised.

Thanks.

[Joseph Labrecque]

Hi. It may have something to do with scope - but would need to see how the file is arranged to know for sure.

[Colin Holgate]

You can solve the problem like this:

this.reset_mark = reset_mark;

this.reset_mark();

function reset_mark() { 

this.mark.x = 1200; 

this.mark.y = -15; 

} 

[ClayUUID · Accepted solution]

Or you could skip the redirection and do this instead...

this.reset_mark = function() { 

     this.mark.x = 1200;

     this.mark.y = -15;

} 

this.reset_mark();

Scope refresher:

Global

bla = "foo";

window.bla = "foo"; // better, because it makes intended global scope explicit

Current TImeline

this.bla = "foo";

Current Frame

var bla;

var bla = "foo";

Declaring a function using the function statement applies the same scope as using var, so it's confined to the scope of the current frame. Using a function expression instead and assigning it as a property of this allows it to be accessible to an entire timeline.

javascript scope of function declarations - Stack Overflow

[markr17328370]

If you are trying to reach a global scope, which I think you are, meaning you want to place this function on one key frame and fire it from a different key frame or layer.  Re write your code like this:

--- write these things this way for local ---

var foo = bar;

var count = 0;

function foobar(){

// do stuff;

}

foobar();

count++;

--- write these things this way for global ---

foo = bar;

count = 0;

foobar = function(){

// do stuff;

}

foobar();

count++;

[ClayUUID]

None of that code has anything to do with what the original poster was trying to accomplish a year ago.

[markr17328370]

ClayUUID  wrote

None of that code has anything to do with what the original poster was trying to accomplish a year ago.

I have also tried:

this.reset_mark();

MovieClip(root).reset_mark();

this.MovieClip(root).reset_mark();

To me it appears that they were not able to access the function by not utilizing the proper scope given the posters attempts of change.  Now if they were modifying the x or y values to achieve proper placement then I would agree with you.  But that was not what the poster was attempting to change.

[markr17328370]

Alternatively, they may have just been having issue with the this. portions which may have been resolved by doing this:

1. var that = this;
3. function reset_mark() { 
4. that.mark.x = 1200; 
5. that.mark.y = -15; 
6. } 

[jeffery wright]

Thanks everyone... I am used to declaring a function this way:

function someFunction(){

};

So yes:

this.someFunction=function(){

}

and calling it:

this.someFunction();

did the trick... it seems backwards to code it that way, I wonder why variables are not coded similarly?

this.myVariable=var; for example.

Thanks again for all your help!

[ClayUUID]

https://forums.adobe.com/people/jeffery+wright  wrote

did the trick... it seems backwards to code it that way, I wonder why variables are not coded similarly?

Variables are coded similarly. Almost identically, in fact.

These declare a variable and a function as private to the local scope:

var myVar = "foo";

function myFunction() {

     alert("bar");

};

These assign a variable and a function as a public property and method, respectively, of an object:

myObj.myVar = "foo";

myObj.myFunction = function() {

     alert("bar");

};

The former uses a function declaration, while the latter uses a function expression.