Trying to get my head around this one.. Incoming data looks like:

[
    {
        "value": {
            "label": "MZ Algal bloom",
            "type": "case",
            "incident": { 
                "name": "Algal bloom"
            },
            "personName": "Lionel Carter"
        }
    },
    {
        "value": {
            "label": "BW Algal bloom",
            "type": "case",
            "incident": { 
                "name": "Algal bloom"
            },
            "personName": "Jerome Yost"
        }
    },
    {
        "value": {
            "label": "Detergent",
            "type": "case",
            "incident": null,
            "personName": "Jerald Legros"
        }
    }
]

I would like to transform this into

[
    {
        "label": "Algal bloom",
        "children": [ 
            { "label": "Lionel Carter", "type": "case"},
            { "label": "Jerome Yost", "type": "case" }]
    },
    { "label": "Detergent", "type": "case" }
]

Basically, the rule is that if incident is not NULL then the incident name becomes the parent and the children hold the personName - otherwise we simply pass through the label and type. I can walk the array and switch out the label with the incident name, but I'm not sure how to group up the incidents..

CodePudding user response：

It's basic grouping with an exception for elements without incident. You can group the elements without incident in a separate group:

const data = [{"value": {"label": "MZ Algal bloom","type": "case","incident": {"name": "Algal bloom"},"personName": "Lionel Carter"}},{"value": {"label": "BW Algal bloom","type": "case","incident": {"name": "Algal bloom"},"personName": "Jerome Yost"}},{"value": {"label": "Detergent","type": "case","incident": null,"personName": "Jerald Legros"}}];

function group(data) {
  const result = data.reduce((acc, { value }) => {
    if (!value.incident) {
      acc.ungrouped.push({ label: value.label, type: value.type });
    } else {
      if (!acc.groups[value.incident.name]) acc.groups[value.incident.name] = { label: value.incident.name, children: [] };
      acc.groups[value.incident.name].children.push({ label: value.personName, type: value.type });
    }
    return acc;
  }, { groups: {}, ungrouped: [] });

  return [...Object.values(result.groups), ...result.ungrouped];
}
console.log(group(data));