cuba-form-behavior.html

<script>

  /**
   * Exposes bean validation errors.
   *
   * @polymerBehavior CubaFormBehavior
   **/
  CubaFormBehavior = {

    properties: {
      /**
       * Map of errors returned by REST API (bean validation) {fieldPath: concatenatedErrorMessage, ...}.
       */
      serverErrors: {
        type: Object,
        notify: true,
        readonly: true,
        value: function() {
          return {};
        }
      },
      /**
       * Raw list of errors returned by REST API (bean validation).
       */
      rawServerErrors: {
        type: Array,
        notify: true,
        readonly: true,
        value: function() {
          return [];
        }
      }
    },

    _clearErrors: function() {
      this.set("serverErrors", {});
      this.set("rawServerErrors", []);
    },

    _handleError: function(result) {
      var resp = result.response;
      if (resp.status === 400) {
        resp.json().then(function(errors) {
          this.set("rawServerErrors", errors);
          var path;
          for (var i = 0; i < errors.length; i++) {
            path = errors[i].path || "$global";
            this._addError(path, errors[i].message)
          }
        }.bind(this));
      }
    },

    _addError: function(path, errorMessage) {
      this.serverErrors[path] ? this.serverErrors[path] += "; " + errorMessage : this.serverErrors[path] = errorMessage;
      this.notifyPath("serverErrors." + path);
    }
  }

</script>