CsvFieldMappingBuilder Class

Definition

Namespace: DataStandardizer.File.CSV

The concrete fluent field-mapping builder. It implements the ICsvFieldMapping*Builder step interfaces that shape the order in which a single field mapping is configured.

Syntax

public sealed class CsvFieldMappingBuilder<TModel, T>
    : ICsvFieldMappingInitialBuilder<TModel, T>,
      ICsvFieldMappingIdentityNextBuilder<TModel, T>,
      ICsvFieldMappingTransformationNextBuilder<TModel>,
      ICsvFieldMappingValidationNextBuilder
    where TModel : class

Remarks

You rarely name this type directly. A pipeline begins at CsvFileMappingBuilder<TModel>.Property<T>, which returns ICsvFieldMappingInitialBuilder<TModel, T>; from there you chain the step methods below. Every step method is implemented as an explicit interface implementation on CsvFieldMappingBuilder<TModel, T>, so each is callable only through the step interface the previous call returned. This is what enforces the allowed call order — for example, once you have set an identity you can no longer set another, and validation follows transformation.

The step interfaces (folded)

The fluent pipeline is defined by a set of small step interfaces, documented here rather than on separate pages:

Step interface	Purpose
`ICsvFieldMappingInitialBuilder<TModel, in T>`	The pipeline entry point; aggregates identity, constant, variable, transformation, and optional steps.
`ICsvFieldMappingIdentityBuilder<TModel, in T>`	Sets the field identity (`HasFieldName` / `HasFieldIndex`).
`ICsvFieldMappingIdentityNextBuilder<TModel, in T>`	Continuation after an identity is set: constant, transformation, variable, or optional.
`ICsvFieldMappingConstantBuilder<in T>`	Sets a constant field value (`HasConstantValue`).
`ICsvFieldMappingVariableBuilder<in T>`	Sets a generated field value (`HasVariableValue`).
`ICsvFieldMappingTransformationBuilder<TModel, in T>`	Attaches a converter (`ConvertUsing`).
`ICsvFieldMappingTransformationNextBuilder<TModel>`	Continuation after a converter: validation or optional.
`ICsvFieldMappingValidationBuilder<TModel>`	Attaches a validator (`ValidateUsing`).
`ICsvFieldMappingValidationNextBuilder`	Continuation after validation: optional.
`ICsvFieldMappingOptionalBuilder`	Marks the field optional (`IsOptional`).

The step methods (explicit on `CsvFieldMappingBuilder<TModel, T>`)

Step method	Returns	Notes
`ConvertUsing(CsvFieldConvertFromString<TModel, T> converter)`	`ICsvFieldMappingTransformationNextBuilder<TModel>`	Sets the deserialization converter (reading).
`ConvertUsing(CsvFieldConvertToString<TModel> converter)`	`ICsvFieldMappingTransformationNextBuilder<TModel>`	Sets the serialization converter (writing).
`ConvertUsing(Type typeConverterType)`	`ICsvFieldMappingTransformationNextBuilder<TModel>`	Sets a `TypeConverter` type. Throws `ArgumentException` if it is not a `TypeConverter`.
`ConvertUsing<TConverter>() where TConverter : TypeConverter`	`ICsvFieldMappingTransformationNextBuilder<TModel>`	Sets a `TypeConverter` type by type argument.
`HasConstantValue(T value)`	`void`	Sets a constant field value.
`HasFieldIndex(int fieldIndex)`	`ICsvFieldMappingIdentityNextBuilder<TModel, T>`	Maps to a field by index. Throws `ArgumentOutOfRangeException` if negative.
`HasFieldName(string fieldName)`	`ICsvFieldMappingIdentityNextBuilder<TModel, T>`	Maps to a field by name. Throws `ArgumentNullException` if `null` or `ArgumentException` if all-whitespace.
`HasVariableValue(CsvFieldGenerate<T> valueGenerator)`	`void`	Sets a generated field value.
`IsOptional()`	`void`	Marks the field optional.
`ValidateUsing(CsvFieldValidate<TModel> validator)`	`ICsvFieldMappingValidationNextBuilder`	Sets a validation delegate.

Constructors

Constructor	Notes
`CsvFieldMappingBuilder(CsvFieldMapping fieldMapping)`	Wraps the mapping the step methods populate. Normally created internally by the pipeline.

Methods

Explicit implementation

CsvFieldMappingBuilder<TModel, T> implements the ICsvFieldMapping*Builder step interfaces explicitly; each method is callable only through the step interface that the previous call returned (see The step methods above). (All targets.)

Member	Returns
`ICsvFieldMappingTransformationBuilder<TModel, T>.ConvertUsing(CsvFieldConvertFromString<TModel, T> converter)`	`ICsvFieldMappingTransformationNextBuilder<TModel>`
`ICsvFieldMappingTransformationBuilder<TModel, T>.ConvertUsing(CsvFieldConvertToString<TModel> converter)`	`ICsvFieldMappingTransformationNextBuilder<TModel>`
`ICsvFieldMappingTransformationBuilder<TModel, T>.ConvertUsing(Type typeConverterType)`	`ICsvFieldMappingTransformationNextBuilder<TModel>`
`ICsvFieldMappingTransformationBuilder<TModel, T>.ConvertUsing<TConverter>()`	`ICsvFieldMappingTransformationNextBuilder<TModel>`
`ICsvFieldMappingConstantBuilder<T>.HasConstantValue(T value)`	`void`
`ICsvFieldMappingIdentityBuilder<TModel, T>.HasFieldIndex(int fieldIndex)`	`ICsvFieldMappingIdentityNextBuilder<TModel, T>`
`ICsvFieldMappingIdentityBuilder<TModel, T>.HasFieldName(string fieldName)`	`ICsvFieldMappingIdentityNextBuilder<TModel, T>`
`ICsvFieldMappingVariableBuilder<T>.HasVariableValue(CsvFieldGenerate<T> valueGenerator)`	`void`
`ICsvFieldMappingOptionalBuilder.IsOptional()`	`void`
`ICsvFieldMappingValidationBuilder<TModel>.ValidateUsing(CsvFieldValidate<TModel> validator)`	`ICsvFieldMappingValidationNextBuilder`

Applies to

Targets netstandard1.3, netstandard2.0, net8.0, and net10.0.