message: Fix: onLoadChoicesFromServer event is fired ad-infinitum
diff: @@ -590,15 +590,19 @@ export class QuestionSelectBase extends Question {
  this.runChoicesByUrl();
  }
  }
  + private isRunningChoices: boolean = false;
  private runChoicesByUrl() {
  - if (!this.choicesByUrl || this.isLoadingFromJson) return;
  + if (!this.choicesByUrl || this.isLoadingFromJson || this.isRunningChoices)
  + return;
  var processor = this.surveyImpl
  ? this.surveyImpl.getTextProcessor()
  : this.textProcessor;
  if (!processor) processor = this.survey;
  if (!processor) return;
  this.isReadyValue = this.isChoicesLoaded || this.choicesByUrl.isEmpty;
  + this.isRunningChoices = true;
  this.choicesByUrl.run(processor);
  + this.isRunningChoices = false;
  }
  private isFirstLoadChoicesFromUrl = true;
  protected onBeforeSendRequest() {
  