[solved] Class data dissapears

Squirrel Code
1

I have some data that seems to disappear from a class on a wakeup call. There is an article about making this mistake by holding the class refernce in a local variable & succumbing to the garbage collector. In my code below, you can see it is stored in a permanent global variable.

Console:
2016-07-01 16:22:48 UTC-5 [Status] Device connected 2016-07-01 16:22:48 UTC-5 [Device] magic data <-- First call from runOnStartup 2016-07-01 16:22:49 UTC-5 [Device] ERROR: the index 'data' does not exist <-- Second call 2016-07-01 16:22:49 UTC-5 [Device] ERROR: at getData:9

Code:
`class example1 {
data = “”

constructor(_data) {
    data = _data
}

function getData() {
    server.log(data)
    imp.wakeup(1,this.getData)
}

}

inst1 <- example1(“magic data”)

function runOnStartup() {
inst1.getData()
}
runOnStartup();`

Note: This also fails:
`
…
inst1 <- example1(“magic data”)

inst1.getData()
`

2

Here is an even more basic example that fails equally:
`
class example1 {
data = “magic data”

constructor() {
}

function getData() {
    server.log(data)
    imp.wakeup(1,this.getData)
}

}

inst1 <- example1()
inst1.getData()

`

3

When using a callback, bind your current context to it with bindenv()

ie instead of imp.wakeup(1,this.getData), try imp.wakeup(1,getData.bindenv(this))

Otherwise, getData will be called with a global context and “data” will not be visible.

Another way around it, if you are not referring to anything particular to the class instance, would be this:

`function getData() {
  server.log(example1.data)
  imp.wakeup(1,example1.getData)
}
`

This could be called in any context

4

Success!
I thought for sure that bindenv wouldn’t work. After you mentioned it I thought it was a weak reference. It did work & I just found in the docs:

Note In standard Squirrel, bindenv keeps a weak reference to the object, but in Electric Imp Squirrel, it is a strong reference.
(source)

Thank you.