Hi, I am having trouble in Node Red converting a JavaScript object to an array or format where I can manipulate the data. Below is what the object looks like, basically a single object "array" with data, where the keys (left hand side) are timestamps that continually change. I am reading these fro…

[image] jstou: I am reading these from a JSON file and converting all the info from the file to JS objects Can you share the bit of the flow where you are doing this part? If you are only interested in the last value, then it would be far more efficient to do that as part of the flow reading …

Knolleary, what I have so far is the file input node reading in the JSON file contents, a JSON node converting all the data to JS objects, then I have individual function nodes to manipulate the different data in which I'm interested. In the function node, I tried to read in the last value of the t…

[image] jstou: When you say "better if you have the data in an array earlier in the flow", are you saying before converting the JSON file contents into JS objects? It depends. I asked if you could share the flow so we can see exactly what you are doing. Without knowing what format your data i…

Ok I have attached the image of the part of the flow where I am reading in the JSON file. Below is the snippet from the JSON showing the "table" that I trying to work with: { "Sites": [ { "PastPowerMeasurements":{"2019-10-04T10:36:34.4726616-04:00":16,"2019-10- 04T10:37:34.4726616-…

I am actually only interested in the last value in the table. In a function node you could use: m = msg.payload.Sites[0].PastPowerMeasurements last = Object.values(m)[Object.values(m).length - 1]; return {payload:last};

[image] bakman2: In a function node you could use: Technically you shouldn't. Object.values and Object.keys do not make any guarantee as to the order of their results. You should not assume the last entry in their results is the 'last' object property. This is why i said you'd have to use Obj…

Thanks for your inputs. Let me try this and get back to you.

I should read. Learn something every day.

Just for reference, if you need a key-value mapping with guaranteed insertion order, there is a Map implementation since ES6. I try to avoid using "plain old JS objects" for dictionary purposes. [image] Map The Map object holds key-value pairs and remembers the original insertion order of…

Trouble Converting JS Object

General

Andrei 15 October 2019 12:11 11

There is a discussion of a (somehow) similar use case in this topic. The final solution for that case was like Nick suggested you now: generate an array from the object, sort the array by timestamp and finally take the last element of the array.

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Trouble Converting JS Object

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