# DataFunctionCall

Location: [gRPC API](https://developer.m-files.com/APIs/gRPC-API/index.md) > [Reference](https://developer.m-files.com/APIs/gRPC-API/Reference/index.md) > [Messages](https://developer.m-files.com/APIs/gRPC-API/Reference/Messages/index.md)

HTML version: https://developer.m-files.com/APIs/gRPC-API/Reference/Messages/MFiles.DataFunctionCall/

Expression that can be evaluated for any document.

- **Full name:** `MFiles.DataFunctionCall`
- **Proto file:** [`mfiles/structs.proto`](https://developer.m-files.com/APIs/gRPC-API/downloads/proto/mfiles/structs.proto)

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## Fields

| Field | Type | Number | Description |
|---|---|---|---|
| <a id="f-data_function"></a>`data_function` | [`DataFunction`](https://developer.m-files.com/APIs/gRPC-API/Reference/Enums/MFiles.DataFunction/index.md) | 1 | The data function. Values: `DATA_FUNCTION_NO_OP` (0), `DATA_FUNCTION_YEAR` (1), `DATA_FUNCTION_MONTH` (2), `DATA_FUNCTION_YEAR_AND_MONTH` (3), `DATA_FUNCTION_DATE` (4), `DATA_FUNCTION_DAYS_FROM` (5), `DATA_FUNCTION_DAYS_TO` (6), `DATA_FUNCTION_INTEGER_SEGMENT` (7), `DATA_FUNCTION_LEFT_CHARACTERS` (8), `DATA_FUNCTION_INITIAL_CHARACTER_GROUP` (9). |
| <a id="f-data"></a>`data` | [`DataFunctionUnion`](https://developer.m-files.com/APIs/gRPC-API/Reference/Messages/MFiles.DataFunctionUnion/index.md) | 2 | The data. |

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## Used in fields

- [`ExpressionUnion.PropertyValueData.data_function`](https://developer.m-files.com/APIs/gRPC-API/Reference/Messages/MFiles.ExpressionUnion/index.md#t-PropertyValueData-data_function): Optional function applied to the value before the comparison, for example `DATA_FUNCTION_DAYS_FROM` to compare the age of a date in days. Unset compares the value as is.
- [`ExpressionUnion.StatusValueData.data_function`](https://developer.m-files.com/APIs/gRPC-API/Reference/Messages/MFiles.ExpressionUnion/index.md#t-StatusValueData-data_function): Function that modifies the status value.
- [`ExpressionUnion.TypedValueData.data_function`](https://developer.m-files.com/APIs/gRPC-API/Reference/Messages/MFiles.ExpressionUnion/index.md#t-TypedValueData-data_function): Function that modifies the typed value.