Constraints
System level validation rules
Field-Level Constraints
Field-level constraints allow you to indicate additional validations that will be applied to fields of a Sheet. These constraints are in addition to the implicit constraints based on types of data. (eg: String, Number)
For example, a value is required for every record (RequiredConstraint), or every record must contain a unique value for the field (UniqueConstraint).
Required Constraint
Required Constraints indicate that the given field must be provided with a non-null value.
null
value in this case constitutes an empty cell.Unique Constraint
Unique Constraints indicate that the given field value must only appear once in all the values for that field.
null
values will appear many times because they are not considered unique as
there is no value to compare.
Computed Constraint
The computed constraint hides the given field from the mapping process, so your users will not be able to map incoming columns to this field.
Sheet-Level
Composite Uniqueness
Composite Uniqueness is a feature where a combination of two or more fields must be unique across an entire Sheet.
To implement composite uniqueness, add the following parameters to the constraints
property:
-
name
defines the name of the constraint -
fields
array of field keys to consider -
type
defines the type of the constraint -
strategy
defines how to determine uniquenessCan either be:
concat
concatenates values from each field defined inside thefields
arrayor
hash
creates a sha1 hash using of the values of each field