Alternatives to eval()

General
1

Hi Guys,

I have a need for a dynamic object defined by a msg.topic within an array and put together the following for testing. Both the solutions for using eval() and object definitions using square brackets work.

However, is there a better way to do this? Baring in mind a completely different solution may be better, but I'm still curious about replacements for eval().

Thanks,

var list = { "find": {"me": [ { "in": {"this": "section"} }, {"in": { "this": "room" } } ] } };
var listArray = list.find.me;
var location = "in.this";
var location2a = "in";
var location2b = "this";
var string = "section";

for (i = 0; i < listArray.length; i++) {
    if (listArray[i].in.this == "section") {
        node.warn("found validation");
        //execute something
    }
    
    if (eval("listArray[i]." + location) == string) {
        node.warn("found using msg strings");
        //execute something
    }
    
    if (listArray[i][location2a][location2b] == string) {
        node.warn("alternative found using msg strings");
        //execute something
    }
}

return msg;
2

Use RED.util.getObjectProperty to get sub properties of an object using a string

var list = { "find": { "me": [{ "in": { "this": "section" } }, { "in": { "this": "room" } }] } };
var listArray = list.find.me;
var location = "in.this";
var location2a = "in";
var location2b = "this";
var string = "section";

for (let i = 0; i < listArray.length; i++) {
    if (listArray[i].in.this == "section") {
        node.warn("found validation");
        //execute something
    }

    if (RED.util.getObjectProperty(listArray[i], location) == string) {
        node.warn("found using msg strings");
        //execute something
    }

    if (listArray[i][location2a][location2b] == string) {
        node.warn("alternative found using msg strings");
        //execute something
    }
}
1 Like
3

Dude you rock, thank you very much. I also wasn't aware of this util module so that's something to explore.

Generally speaking are there any other alternates to eval()?

4

If you are using Monaco editor, type RED.util. and you will see all util functions.

2 Likes
5

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