Persistent global context used in template node

General
1

Hallo,

This code works perfect in a template node (html) to retrieve cvMode as a global variable... in memory.

Now I installed contrib-persistent-global-context, and with a function node... global.set('cvMode', "ON", "file").
Set & Get work fine.

settings.js contextStorage is set:
contextStorage: {
default: "memoryOnly",
memoryOnly: { module: 'memory' },
file: { module: 'localfilesystem' }
},

7 Dec 09:17:27 - [info] Node-RED version: v3.1.0
7 Dec 09:17:27 - [info] Node.js version: v18.18.2
7 Dec 09:17:27 - [info] Linux 6.1.0-rpi6-rpi-v8 arm64 LE

How to change value="{{global.cvMode}}" to get the variable from "file" ?

I also tried function getDocGVF which is called by windows.onload as part of :
function getDocGVF() {
document.getElementById('cvMode').value = global.get('cvMode', "file");
}

Neither worked.
:frowning:

Pls your advise.
Thanks.
T

2

oops... the copy lost the code:
input type="text" id="cvMode" name="cvMode" value="{{global.cvMode}}"

3

In order to make code readable and usable it is necessary to surround your code with three backticks (also known as a left quote or backquote ```)

``` 
   code goes here 
```

You can edit and correct your post by clicking the pencil :pencil2: icon.

See this post for more details - How to share code or flow json

4

From template node help text

t is possible to use a property from the flow context or global context. Just use {{flow.name}} or {{global.name}} , or for persistable store store use {{flow[store].name}} or {{global[store].name}} .

So {{global[file].cvMode}} should work

5

Thank You.

  1. I will comply the 3 backticks next time.
    2.Yes, the suggestion works perfect
  2. the template node help text... slipped my attention. Too much focussed on the syntax of set/get.
    Best Regards.
    T
6

All GlobalVariables work now fine in functions and can be used in html.
On RPi I can observe them landing in directory /home/rpi/.node-red/context/global/global.json.

But when I drag an Inject, the Persistent-Global-Context and a Debug node on a flow, then I get :
"Error: ENOENT: no such file or directory, open 'undefined/GlobalContext.json'"
and
"Cannot find json file inside [undefined/GlobalContext.json]!" from the Debug node

A Stop/Start of Node-Red does not show errors on the CommandLine of RPi.

What am I missing ?

Cheers,
T

7

I don't understand what you mean by that.

There is no need for that, persistent context is built into node-red core.

8

Thank You.
As there is no need... I removed it, and all works still fine.
As a NR novice I just tried to understand why

image
image721×234 44.5 KB

Cheers,

T

9

I tried it and get the same error. It appears to be a bug in the node. You could report an issue on the node's github page if you wanted to.