JSON.parse no longer available?

Setup, Configuration and Use Scripts & Rules
1

Hi,

I’m trying to parse a JSON and use it in a for each, therefore it needs to be an object and cant use transform("JSONPATH", ...).

When I use javascript JSON.parse(json) I get an error:

14:37:16.937 [ERROR] [.internal.handler.ScriptActionHandler] - Script execution of rule with UID 'rule-1' failed: The name 'JSON' cannot be resolved to an item or type; line 10, column 16, length 4 in rule

Cant javascript be used anymore? Do I need to import something?

Kind regards,
Bastiaan

2

Would you show us your whole rule? That looks like a DSL error report.

3

Sure, it’s nothing special.

when
    Item Helium_Explorer_Witnessed received update
then
    val json = (Helium_Explorer_Witnessed.state as StringType).toString
    val data = JSON.parse(json)
end
4

That is fragment of file-based DSL rule syntax, but not a complete rule (missing rule "myrule"). Where are you putting it, exactly? DSL does not include a JSON utility. This is not javascript.

5

Sorry, indeed I did not posted the rule "Helium - Activity. Yes this is currently a textual rules file. /rules/helium.rules

So within this rule I cant use javascript? Where can I use it?

6

No, that has never been possible.

You can call javascript JS transforms from a DSL rule, but can only get a single string in return

Many people create javascript rules using GUI in OH3. This is a whole new method of working for you to learn. Or javascript rules may used in their own files based version.
Note that OH3 currently supports two different versions of javascript rules
Background -

If you want to stick with DSL, you might be more explicit about what you are trying to achieve. JSONPATH transformation has limitations, some can be worked around. Example

1 Like
7

Ok digged a little deeper into your posts. I’m going to move all my DSL rules to UI JSScripting rules. Javascript is a much more understandable language for me.

I got it working in DSL do, for others:

val int numElements = Integer.parseInt(transform("JSONPATH", "$.data.length()", json))
logInfo("test", "There are {} elements in array", numElements)

var int i
for (i=0; i < numElements; i++) {
   val name = transform("JSONPATH", "$.data.[" + i + "].name", json)
   val time = transform("JSONPATH", "$.data.[" + i + "].time", json)

    logInfo("helium", "time={}:{}", name, time)
}

But it’s very cluncy.

With javascript:

var json = JSON.parse(item);
json.data.forEach(function(row) {
    console.log(row.name, row.time)
}

Thanks for the help @rossko57

1 Like