Where do you store your "global" (app-wide) variables?

Help & Support
1

There are some functions in my apps that will need to know how old the current instance of the app is. I didn’t find anything on the documentation reference, so I am planning to capture the postinitialize event and then record the current time on an app-wide variable.

  1. Where do you keep your app-wide vars?
  2. Did I miss the property of the PlayCanvas engine, in the documentation, that keeps record of when it started, or for how long it has been running?
2
  1. The project settings have a script loading order. Whichever script has a global var declaration should be loaded before the others, then others will have access to them.
  2. There is no public API for such thing. It sounds like a simple thing one of you scripts could track by recording the app start time.
3

Thank you for the answer.

But is there any script that is loaded in the PlayCanvas editor that does that (a global var declaration)? At first, I thought I should just store it in the pc variable, after checking if the variable already exists, and I implement that on every script asset that needs it, like so:

if (pc.myVar === undefined) {
    pc.myVar = new Date.now();
}

I know a lot goes under the hoods, and was wondering if there is a best practice for that. If you had to store a number in a variable that should be accessible from any other asset in your project, where would you put it? How would you implement it?

4

As mentioned, create a script that contains a global variable

var MyApp = {};
MyApp.starttime = new Date().now()

In settings, make sure this script is loaded first.

Another option is to just use window.starttime = new Date().now()

5

Okay thank you, I’ve created a global variable to store it.

Anyway, in the tutorial page, there is a flow that shows the high level flow of a PlayCanvas application: https://developer.playcanvas.com/img/user-manual/scripting/application-lifecycle.png

According to this, as soon as the application finishes initializing everything, it fires an event called postinitialize. I am trying to listen to it to get the exact time the application starts running, but I am having troube, since the pc object does not have the EventHandler methods. Where should I invoke this? I’ve tried this so far, to no avail:

Global.js:

let myHandler = new pc.EventHandler();
myHandler.on('postinitialize', (e) => {
    console.log('Captured "postinitialize".')
}); // this does not capture the event but I don't know why

Movement.js:

/* some code */

// initialize code called once per entity
Movement.prototype.initialize = function() {
    /* code code code */

    this.on('postinitialize', (e) => {
        console.log('"postinitialize" captured successfully!');
    });

    // some more code
};

/* lots of other code */

Do you think that I should just initializationTime = new Date.now() inside the pototype.initialize() of the object?

6

According to the engine source code, its postInitialize

or implement

Movement.prototype.postInitialize = function() {
}
7

Thank you. You are correct, I failed to notice it is ´postInitialize´ with a capital ´I´; however, fixing that didn’t make it work.

The prototype.postInitialize worked.

8

Should be this.app.systems.on("postInitialize"). It is preferred to use the script method, though.

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