Data view mapping in Power BI visuals

Question

Good day

I am creating custom visualization on d3js and pbiviz for powerbi

Here is the code in capabilities.js:

{
"dataRoles":[
    {
        "displayName": "HoleDepth",
        "name": "depth",
        "kind": "Grouping"
    },
    {
        "displayName": "Days",
        "name": "days",
        "kind": "Measure"
    },
    {
        "displayName": "Diametrs",
        "name": "diametrs",
        "kind": "Measure"
    },
    {
        "displayName": "Sensor1",
        "name": "sensor_1",
        "kind": "Measure"
    },
    {
        "displayName": "Sensor2",
        "name": "sensor_2",
        "kind": "Measure"
    },
    {
        "displayName": "Sensor3",
        "name": "sensor_3",
        "kind": "Measure"
    },
    {
        "displayName": "Sensor4",
        "name": "sensor_4",
        "kind": "Measure"
    }
],
"dataViewMappings": [
    {
        "categorical": {
            "categories": {
                "for": { "in": "depth" }
            },
            "values": {
                "select":[
                    { "bind": { "to": "days" } },
                    { "bind": { "to": "diametrs" } },
                    { "bind": { "to": "sensor_1" } },
                    { "bind": { "to": "sensor_2" } },
                    { "bind": { "to": "sensor_3" } },
                    { "bind": { "to": "sensor_4" } }
                ]
            }
        }
    }
]

}

But in visualization it is inconvenient to use categorical -> values array

Is it possible to categorical -> values was like an object with keys?

Answer 1

I do not think that this is possible directly through data mapping. What I usually do if I want to have data prepared in the specific format, convenient for visualization with d3.js, is the custom function that transforms the data from VisualUpdateOptions. Then I call this function inside public update(options: VisualUpdateOptions)

Answer 2

Bit of an old post, but I've just started on pbiviz and typescript and had to work this out, so hopefully this helps others who come by

You can reference objects from the dataview using find

For example:

let days = dataView.categorical.values.find(value => value.source.roles.days === true);
let diametrs = dataView.categorical.values.find(value => value.source.roles.diametrs === true);
let sensor_1 = dataView.categorical.values.find(value => value.source.roles.sensor_1 === true);

and then pull their values:

let days_value = days.values[0];
let diametrs_value = diametrs.values[0];
let sensor_1_value = sensor_1.values[0];

so you don't need to rely on the array index