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• The Data Access Layer needs to be able to bypass the validation and construct Fields that violate the current Validation Rule. Despite the Administrator changing the Validation Rule for a Field, we still need to be able to construct Field objects based on the old data e.g. when rendering a Form that was filled years ago. This could potentially be resolved by storing the current Validation Rule whenever we store the Field.

• In this design, the Field model has an indirect link to the Data Access Layer/Repository via the IValidator. The injection of Services/Repositories to Domain Models seems to be generally frowned upon.

• The Data Access Layer needs to be able to bypass the validation and construct Fields that violate the current Validation Rule. Despite the Administrator changing the Validation Rule for a Field, we still need to be able to construct Field objects based on the old data e.g. when rendering a Form that was filled years ago. This could potentially be resolved by storing the current Validation Rule whenever we store the Field.

• In this design, the Field model has an indirect link to the Data Access Layer/Repository via the IValidator. The injection of Services/Repositories to Domain Models seems to be generally frowned upon.

I've decided to proceed with Option #1 for now, attempting to take care not to assign too many responsibilities to the Domain Model. Those facing a similar situation may also want to check out the related questions Validation and authorization in layered architecture and Data input validation - Where? How much?.

I've decided to proceed with Option #1 for now, attempting to take care not to assign too many responsibilities to the Domain Model. Those facing a similar situation may also want to check out the related questions Validation and authorization in layered architecture and Data input validation - Where? How much?.

Edit (Complexity of validations)

The validation cases that have come up for now are relatively simple; the Field value must be e.g. numeric, a date, a date with a time or be an existing value in a database column. However, I suspect complexity to gradually increase over time. For example, the validation solution needs to be built with internationalization in mind - things such as Dates may be input in a locale-specific syntax.

I've decided to proceed with Option #1 for now, attempting to take care not to assign too many responsibilities to the Domain Model. Those facing a similar situation may also want to check out the related questions Validation and authorization in layered architecture and Data input validation - Where? How much?.