[data grid] getCellValue does not work with nested objects when columns use valueGetter

[artzlite]

The problem in depth

The provided solution in Issue #13281 suggests using row[field] in the getCellValue function to access values for custom aggregations. However, this approach does not work when columns use a valueGetter and assign values from nested objects.

1. Nested Objects with valueGetter :
   For example, if a column is defined like this:

{
   field: "value",
   headerName: "Value",
   valueGetter: (_, row) => row.orderDetail?.value,
}

Using row[field] doesn’t retrieve the value.
2. Calculated Fields:
For columns like this:

{
    field: "calculatedValue",
    headerName: "Calculated Value",
    valueGetter: (_, row) => row.value1 + row.value2,
}

To use this in custom aggregation, I have to duplicate the logic (row.value1 + row.value2) in my custom aggregation function. This feels messy and hard to maintain.

I thought of some workarounds, but none are great:

1. Moving all nested object fields to the root level of the row.
2. Pre-calculating every field and keeping the results directly in the row object.

The problem is that my row objects are already complex, and doing this would make them even harder to manage. For example, here’s the kind of data structure I’m working with:

[
    {
        "6rFNvcvLrWQLw": "8XwFA",
        "KCyAfh": "xlKOp",
        "PGdgB8bKON41g3Pl3SvCzvAk": {
            "u5BuaDsGo9bjuhVjpB": "91tnV",
            "Z3TaoCQ": "trBKx",
            "ztsKYO": "Gr1NZ",
            "OC8J": "jESNu",
            "6Yham1ydQctXM": 10000,
            "C7PS4MdTG": 200,
            "7mRFIlHAfY": false,
            "IjTAKL4k50V": true,
            "O7WdjAnU": true,
            "vfmRJw6Cz": false,
            "EPDR1ADPs": true,
            "1t7AoqiMXXFsP": 5000,
            "0sadKfrwgY50iB": 0.2,
            "vfYKaO7rlNC9bI8SPYp": 0.8,
            "VPVvP8lCg": 3,
            "C3HLOEeWE4w": 5,
            "RCLw6aQC": 205
        },
        "kJHH7VOVy6P5Obd1h": {
            "IhxpJkbbZ8": "cGnBj",
            "s2kb8Jqm9cYO1": "chWEv",
            "AMmF9WDDx9D2BeUXo": "fGY6A",
            "Evcadu": "Qpapl",
            "CWMJ": "MZy8L",
            "8H8fk2c": "vxWvv",
            "unVq3kCssvE": "hd0v1",
            "BIwtYhni2T7gl": "nQmzq",
            "JXlq4iS1gAP": "KwOnB",
            "Ga8SNMAz5": "KNXOL",
            "xnvzC": 200,
            "lG18OE3hvnIg": 0,
            "o19XYjzmBztH0": 10000,
            "IjzuZaRWo": 0,
            "RPKPC9OtyuM3dlV13O": 2000,
            "WxPjGMbRwVXj": 0,
            "6ajFjK6tSNrMzB": 10000,
            "MTmJ": "lqkvA",
            "VLzd14CofXkXeIF": "4qkqV",
            "bOJvRc7FQH0o55bhK": 12347
        },
        "O9lJph": [
            {
                "XPPqLHKNIifAXqV": "9jxTz",
                "vha4AadnIFl": "70iUi",
                "qQVtEteoHRAj": 0,
                "asmLQpnM7": 0,
                "5ylzD5WXlEyUB": 0,
                "2YLLTZb": 0,
                "qYxQj9QqO": 10000,
                "Cnh8": "CeVow"
            },
            {
                "BWvwAhFYOS0sKP1": "aqylD",
                "3ga91QR7BIt": "ymU0m",
                "r8rH4LQVDAzs": 0,
                "4e0BwknPw": 0,
                "I5JXak68GmN6b": 0,
                "MosKxpt": 0,
                "KePVvz2tH": 10000,
                "lOWG": "fq47A"
            }
        ],
        "ixmr": "ERb5N"
    }
]

Is there a better way to handle this?

Thankyou.

Your environment

`npx @mui/envinfo`

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  Output from `npx @mui/envinfo` goes here.

Search keywords: Custom aggregation with getCellValue

Order ID: 93539

[michelengelen]

To help us diagnose the issue efficiently, could you provide a stripped-down reproduction test case using the latest version? A live example would be fantastic! ✨

For your convenience, our documentation offers templates and guides on creating targeted examples: Support - Bug reproduction

Just a friendly reminder: clean, functional code with minimal dependencies is most helpful. Complex code can make it tougher to pinpoint the exact issue. Sometimes, simply going through the process of creating a minimal reproduction can even clarify the problem itself!

Thanks for your understanding! 🙇🏼