Hi. When i am trying to get a global variable with function TotkWh = global.get("power.VK.gang.kWh.Total")||0; i get this error: function : (error) "TypeError: Cannot read property 'VK' of undefined" If i write it without . like this it works: TotkWh = global.get("powerVKgangkWhTotal")||0; i …

A context variable name must be a valid JavaScript identifier. That means it cannot have dots in its name, nor can it have [ ] - and I'm sure some other punctuation. When you do context.get('parts.foo') we will look up the context variable called parts and return its foo property. If parts doesn'…

I can confirm that one cannot have . in a context variable name, and I can imagine why. Whether that is a documented feature, an undocumented feature or a bug I don't know. There are probably a number of other characters that are not legal also.

It works fine as long as it is defined first. Se this flow: ▶ Flow If you read it gets error. If you save it saves. And now you can read. So it is only the ||0 that is not working as expected. Thanks

I don't think it is the || 0 that is failing, it is the context.get("a.b.c") where it has not previously been set with context.set

Your get would work if your "power" variable is an object with a nested property structure. Your undefined result is saying that the function is looking for a property that doesn't exist, leading me to suspect you're not storing as an object.

Power isn't a variable when used like this (or at least it shouldn't be, I don't think), it is a string that happens to have dots in it. Having said that I haven't examined the docs for context.set/get. Not at pc at the moment.

Ok. [image] Colin: I don't think it is the || 0 that is failing, it is the context.get("a.b.c") where it has not previously been set with context.set Is there another way i can easy check if it exist or have been set and if not set it to 0? [image] JayDickson: Your get would work if you…

I' m using an object called state and store it to a global variable. But I first get/set the whole object: global.set('state', state); var state = global.get('state'); ... var value = state.value;

Thanks knolleary for the detailed responce. Here is what i am running and can confirm that it works as expected if i run it as a flow variable istead of a global. [function] Will just use the flow variable and move everything to same flow for now until 0.20.0 as i dont know how to wrap it in a tr…

[image] Lost: as i dont know how to wrap it in a try/catch block. No problem - glad you got it working. Just so you know, the try/catch block method would look like: var TotkWh; try { TotkWh = global.get("power.VK.gang.kWh.Total") } catch(err) { // an error has been thrown - ignore it …

though in general it's usually best to try to keep the scope of variables as small as possible (i.e. prefer local (inside a function) - then flow - then global) to help avoid name clashes etc when you copy things around.

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Error or bug with global get when undefined

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zenofmud 8 February 2019 00:16 15

You can also read A guide to understanding 'Persistent Context'

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Error or bug with global get when undefined

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