update skills and code based on official documentation

react/common/src/ElixFormsComponentAbstract.tsx

@@ -136,6 +136,8 @@ export default abstract class ElixFormsComponentAbstract extends Component<IElix
     } = this.props;
 
     const queryParams = new URLSearchParams(window.location.search);
+    const missingMandatoryParams = this.mandatoryFormFieldNames.filter(paramName => !queryParams.has(paramName));
+    const hasAuthenticationError = missingMandatoryParams.length > 0;
 
     return (
       <div className="container_12" id="pageBody">
@@ -180,16 +182,24 @@ export default abstract class ElixFormsComponentAbstract extends Component<IElix
                     {environmentMessage && <div>{environmentMessage}</div>}
                     {description && <div>{description}</div>}
 
-                    {this.renderExtraContentPre()}
+                    {hasAuthenticationError ? (
+                      <FluentUI.MessageBar messageBarType={FluentUI.MessageBarType.error} isMultiline={false}>
+                        Accesso non autorizzato. Parametri obbligatori mancanti ({missingMandatoryParams.join(', ')}).
+                      </FluentUI.MessageBar>
+                    ) : (
+                      <>
+                        {this.renderExtraContentPre()}
 
-                    <form action="https://procedure.unipr.it/rwe2/ComeBackToElixAndSave" method="post" acceptCharset="ISO-8859-1">
-                      {this.createMandatoryFormFields(queryParams)}
-                      {this.createAdditionalFormFields()}
-                      {this.renderCustomFormFields()}
-                      <input type="submit" value="Submit" />
-                    </form>
+                        <form action="https://procedure.unipr.it/rwe2/ComeBackToElixAndSave" method="post" acceptCharset="ISO-8859-1">
+                          {this.createMandatoryFormFields(queryParams)}
+                          {this.createAdditionalFormFields()}
+                          {this.renderCustomFormFields()}
+                          <input type="submit" value="Submit" />
+                        </form>
 
-                    {this.renderExtraContentPost()}
+                        {this.renderExtraContentPost()}
+                      </>
+                    )}
                   </div>
                 </div>
               </div>
@@ -365,7 +375,7 @@ export default abstract class ElixFormsComponentAbstract extends Component<IElix
 
   private createHiddenInput(paramName: string): JSX.Element {
     const textValue = QueryParamHelper.getDecodedTextFromQuery(paramName) ?? "";
-    return <><input type='text' id={paramName} name={paramName} defaultValue={textValue} /><br /></>;
+    return <input type="hidden" id={`${paramName}_hidden`} name={paramName} defaultValue={textValue} />;
   }
 
   private createNumberInput(paramName: string, label: string, required: boolean = false): JSX.Element {