CODEWITHSUNDEEP
javascriptnode-red
Денис Пархоменко
Денис Пархоменко

Reputation: 1

How to store array in node red context

I'm trying to store and get back array in Node Red context (or flow) object.

I do this to store, can see output message with array:

var acstate=[];
for(var i=0;i<15;i++){
     acstate[i]=1;
    }
context.set("acstate",acstate);
msg={'payload':acstate};
return msg;

This node to get array from context:

var acstate=[];
acstate = context.get('acstate');
for(var i=0;i<15;i++){
     node.warn(acstate[i]);
    }
msg={'payload':acstate};
return msg;

It shows 

"TypeError: Cannot read property '0' of undefined"

Can't find info about storing arrays, is it possible with context? If not, what can I use to keep data?

Thank you!

Upvotes: 0

Views: 11934

Answers (3)

Денис Пархоменко
Денис Пархоменко

Reputation: 1

Sorry I didn't mention that I'm trying to write to context and to read from context from different nodes. Looks like each node has it's own context, thats why data stored in context of one node is not available in context of another node. So now I tried to change "context" to "flow" and it works! 

var temp = flow.get('acstate');

Thank you for answers!

Upvotes: 0

SPlatten
SPlatten

Reputation: 5762

You don't need to create the array before assigning it to the return from another function:

    var acstate; /* =[] NOT REQUIRED; */
    acstate = context.get('acstate');

    if ( typeof acstate == "object" 
    && typeof acstate.length == "number"
    && acstate.length > 0 ) {
        for(var i=0;i<acstate.length; i++){
           node.warn(acstate[i]);
        }
    }
    msg={'payload':acstate};
    return msg;

Upvotes: 1

Sachin Dongre
Sachin Dongre

Reputation: 25

You can write like

var acstate=[];
var temp = context.get('acstate');

for(var x=0;x<temp.length;x++){
     acstate.push(temp[x]);
    }

for(var i=0;i<15;i++){
     node.warn(acstate[i]);
    }
msg={'payload':acstate};
return msg;

Upvotes: 1

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