Example "Creating custom field type" gets error: Uncaught ...

[sttn]

When I will create a custom field type like the documentation, I get following error:


The json-File: custom/Espo/Custom/Resources/metadata/fields/fieldcomb.json:

{
    "view": "custom:views/fields/fieldcomb"
}

The Javascript-File: client/custom/src/views/fields/fieldcomb.js

   define(['views/fields/base'], (BaseFieldView) => {

       return class extends BaseFieldView {
      
       // Templates for all view modes.
       // detailTemplateContent = ` ... `;
       // listTemplateContent = ` ... `;
       // editTemplateContent = ` ... `;
       // searchTemplateContent = ` ... `;

       setup() {}

       afterRender() {}

       }
   });​

At the first step, i will use the default templates. I also test it with own template, i get the same result.

I add the feid to a test entity with the name CTest over the Administration-Panel:


Layout: ./custom/Espo/Custom/Resources/layouts/CTest/detail.json

[
   {
       "rows": [
           [
               {
                   "name": "name"
               },
               {
                   "name": "fieldCombTest"
               }
           ]
       ],
       "style": "default",
       "label": "Overview"
   }
]

Entity: custom/Espo/Custom/Resources/metadata/entityDefs/CTest.json:

{
   "fields": {
    ...
       "fieldCombTest": {
           "type": "fieldcomb",
           "isCustom": true
       }
   ...
​

What's my mistake? Doas someone have an idea?