docs: suggestOnCreate

Author: ivictbor

adminforth/documentation/docs/tutorial/03-Customization/13-standardPagesTuning.md

@@ -225,6 +225,14 @@ export default {
         {
           name: 'created_at',
           type: AdminForthDataTypes.DATETIME,
+//diff-add
+          showIn: {
+//diff-add
+            all: true,
+//diff-add
+            create: false,  // don't show field in create form
+//diff-add
+          }
 //diff-add
           fillOnCreate: ({ initialRecord, adminUser }) => (new Date()).toISOString(),
         },
@@ -245,6 +253,14 @@ export default {
         {
           name: 'created_by',
           type: AdminForthDataTypes.STRING,
+//diff-add
+          showIn: {
+//diff-add
+            all: true,
+//diff-add
+            create: false,  // don't show field in create form
+//diff-add
+          }
 //diff-add
           fillOnCreate: ({ initialRecord, adminUser }) => adminUser.dbUser.id,
         },
@@ -256,6 +272,32 @@ export default {
 
 > Same effect can be achieved by using [hooks](/docs/tutorial/Customization/hooks/#example-modify-the-created-object-before-it-is-saved-to-the-database). But `fillOnCreate` might be shorter and more readable.
 
+### Suggest default value in create form
+
+You can suggest a default value for a field in the create form which user can instantly change even before creating record.
+This might be used to give user some example value or to suggest some default value.
+
+```typescript title="./resources/apartments.ts"
+export default {
+      name: 'apartments',
+      fields: [
+        ...
+        {
+          name: 'description',
+//diff-add
+          suggestOnCreate: 'Great apartment in the heart of the city',
+        },
+      ],
+    },
+    ...
+```
+
+A difference between `fillOnCreate` and `suggestOnCreate`:
+
+* `fillOnCreate` is called on the backend when the record is saved to a database. Value returned by `fillOnCreate` will be saved to the database. 
+* `suggestOnCreate` is just a single value that will be substituted in create form. User can change it before saving the record.
+* `fillOnCreate` should be used when `showIn.create` is a `false` value because if it is `true`, the input will be shown in the create form but then(during actual save to db) it will be overwritten by the value returned by `fillOnCreate`.
+* `suggestOnCreate` should be used with `showIn.create` set to true because if it is not set, the input will not be shown in the create form and default suggestion will not make sense.
 
 ### Link to create form with preset values