Validating Dates

Angular Form Engine scope. This page documents date validation in @openmrs/ngx-formentry. Equivalent schema fields may behave differently in the React Form Engine. See About this documentation.

This type of validation enforces certain conditions for date inputs. You can use date validation to guarantee that a date input only allows:

• Past or present dates
• Past, present or future dates

Here's a question from the Reproductive History section of an HIV Adult Return visit form:

{
  "label": "LMP",
  "id": "lmpDate1",
  "questionOptions": {
    "concept": "a89ff758-1350-11df-a1f1-0026b9348838",
    "rendering": "date"
  },
  "type": "obs",
  "validators": [
    {
      "type": "date"
    }
  ]
}

This question seeks to establish when the client last menstruated (LMP is short for Last menstrual period). Note that the first value of the validators array is a validator of type date. To properly understand what this date validator is doing, it might help to look at this snippet from its source code:

// Question validator factory
if (question.validators) {
  _.forEach(question.validators, (validator: ValidationModel) => {
    switch (validator.type) {
      case 'date':
        list.push(this.dateValidator);
 
        const allowFutureDates: boolean = (<DateValidationModel>validator)
          .allowFutureDates;
 
        if (!allowFutureDates) {
          list.push(this.futureDateRestrictionValidator);
        }
        break;
      }
    }
  }
}

We see that the validator optionally has a property named allowFutureDates and that this property defaults to false. The date validator will, by default, not allow you to set a future date as the value of the field. If you do so, it will render a validation error:

You can override this behaviour and permit setting dates in the future by setting allowFutureDates to the string "true" in your validator definition. The engine ignores any other value, including the boolean true and misspellings such as allowFutureDate:

{
  "validators": [
    {
      "type": "date",
      "allowFutureDates": "true"
    }
  ]
}