Docs: Add payload examples for Bar Chart

[joepavitt]

Description

Adds documented examples of payloads to send to a bar chart

Closes #355

[colin-grierson]

Joe, many thanks for your quick response.
Alas, maybe I don't yet have the background knowledge, or am too old school but I can't get it to work.
I want to output the graph in one message (I can make it work with multiple messages)
My payload is structured as in your example (I think):
msg : Object
object
payload: array[10]
0: object
category: "SASMAR"
value: 94351308
1: object
category: "SASOWNER"
value: 54322300
2: object
3: object
4: object
5: object
6: object
7: object
8: object
9: object
category: "SASLJ"
value: 1197152
_msgid: "7631345d0d5c80a5"
In the chart node I have type: Bar. What should I set the Properties Series and Y to?
I have tried quite a number... my best result is with Series: msg. = key:category and Y: key: = value
This results in two bars. The first blank, the second for SASLJ and 1197152 - my last data element.
How do I make this work?

In the documentation you talk about setting the property 'Series', and give example data, but do not say how 'Y' is set. I think it would be much easier to follow if we had: Series, Y, data, Result for the various representative cases.

Thanks again, Colin

[joepavitt]

Series: msg. = key:category and Y: key: = value

I would have expected this to work. I will investigate.

[joepavitt]

Can I check which version of Dashboard you're using? Just tried this with the following dataset:

[
    {
        "category": "SASMAR",
        "value": 94351308
    },
    {
        "category": "SASOWNER",
        "value": 54322300
    },
    {
        "category": "SASLJ",
        "value": 1197152
    }
]

and with the following chart config:

and it rendered:

[joepavitt]

I have also just updated the documentation further to be more explicit about the options available.

[colin-grierson]

Node-RED version: v3.1.0
Node.js version: v18.17.1
flowfuse/node-red-dashboard 0.7.2
Found it - imagine a shameface icon..
Series msg.key:category

Series key:category

Sigh, thanks again for your help

[colin-grierson]

Comment/nice to have...
When we are adding a set of data points to a chart, as in my Top 10 Users example, we most likely want to replace the existing chart than add to it. Of course this can be done by sending a separate message containing a null array, but this is a minor hassle - and easy to miss if most of the time the series are the same and only the values change.
It would be nice to have an option on the chart - maybe 'Clear existing data?' Y/N

[joepavitt]

It would be nice to have an option on the chart - maybe 'Clear existing data?' Y/N

You're not alone in your request: #358

[joepavitt]

Found it - imagine a shameface icon..

Maybe I can include more screenshots of configurations in the docs to make this clearer?