Dynamically build Aurelia Validation rules.

aureila-dynamic-validation-rules.js

//This is a rough attempt at dynamically building validation rules based on a JSON document.

let rules = [];
Forms[this.viewing].map(field => {
  if(field.required && !field.viewIf){
    rules.push(ValidationRules.ensure(field.propName).required().rules[0])
  }
         
  if (field.required && field.viewIf) {
    rules.push(ValidationRules.ensure(field.propName).required()
      .when(val => this.currentDoc[field.viewIf] === field.viewIfValue)
      .rules[0])
  }
});

forms.json

{
  "fieldDescription": "Dashboard Link",
  "fieldType": "link-field",
  "propName": "dashboardLink",
  "viewIf": "previousProperty",
  "viewIfValue": true,
  "required": true
}