refactor(validators): default validators

Author: kevinkosterr

src/mixins/abstractField.js

@@ -8,7 +8,7 @@ function getValidator (validator) {
     if (validators[validator] === undefined) throw new Error('Invalid validator: ' + validator)
     return validators[validator]
   }
-  return null
+  throw new Error('Couldn\'t get validator for: ' + validator)
 }
 
 export default {
@@ -53,7 +53,7 @@ export default {
       let results = []
 
       if (!this.isDisabled && this.field.validator && !this.isReadOnly) {
-        const fieldValidators = []
+        const fieldValidators = [ ...this.defaultValidators ]
 
         if (Array.isArray(this.field.validator)) {
           /** Retrieve actual validators for every given validator in Array */
@@ -64,11 +64,6 @@ export default {
           fieldValidators.push(getValidator(this.field.validator))
         }
 
-        /** Always include 'required' validator, whenever the field is required */
-        if (this.isRequired && !fieldValidators.includes(validators.required)) {
-          fieldValidators.push(validators.required)
-        }
-
         fieldValidators.forEach(validator => {
           const isValid = validator(this.currentModelValue, this.field, this.model, this)
           if (!isValid) results.push(getMessage(validator.name))
@@ -153,6 +148,28 @@ export default {
 
   computed: {
 
+    /**
+     * Compute all validators that should be present by default.
+     *
+     * @returns {*[]}
+     */
+    defaultValidators () {
+      const fieldValidators = []
+
+      if (this.isRequired && !fieldValidators.includes(validators.required)) {
+        fieldValidators.push(validators.required)
+      }
+
+      if (this.field.min) {
+        fieldValidators.push(validators.minLength)
+      }
+
+      if (this.field.max) {
+        fieldValidators.push(validators.maxLength)
+      }
+      return fieldValidators
+    },
+
     /**
      * Compute the current value of this field by accessing the form's model object.
      *

src/validators/index.js

@@ -15,6 +15,32 @@ export default {
     return !!(fieldComponent.isRequired && isNotEmpty(value))
   },
 
+  /**
+   * Check if field value is the minimum provided length
+   *
+   * @param {any} value - The current value of the field.
+   * @param {Object} field - The field as specified in the form's schema.
+   * @param {Object} _model - The form model.
+   * @param {Component} _fieldComponent - Field's Vue Component.
+   * @returns {boolean} - Returns 'true' if the field is required and the value is not empty, otherwise false.
+   */
+  minLength (value, field, _model, _fieldComponent) {
+    return field.min && value.length >= field.min
+  },
+
+  /**
+   * Check if field value is the maximum provided length
+   *
+   * @param {any} value - The current value of the field.
+   * @param {Object} field - The field as specified in the form's schema.
+   * @param {Object} _model - The form model.
+   * @param {Component} _fieldComponent - Field's Vue Component.
+   * @returns {boolean} - Returns 'true' if the field is required and the value is not empty, otherwise false.
+   */
+  maxLength (value, field, _model, _fieldComponent) {
+    return field.max && value.length <= field.max
+  },
+
   /**
    * Checks if the field's value is of type string.
    *