fix(Forms): enhance transformIn and transformOut to support changed array and object instances

packages/dnb-design-system-portal/src/docs/uilib/extensions/forms/Value/SelectCountry/info.mdx

@@ -27,16 +27,21 @@ const MyComponent = () => {
 
 ### TransformIn and TransformOut
 
-You can use the `transformIn` and `transformOut` to transform the value before it gets displayed in the field and before it gets sent to the form. The second parameter is the country object. You may have a look at the demo below to see how it works.
+You can use the `transformIn` and `transformOut` to transform the value before it gets displayed in the field and before it gets sent to the form context. The second parameter is the country object. You may have a look at the demo below to see how it works.
 
 ```tsx
-const transformOut = (value, country) => {
-  if (value) {
-    return `${country.name} (${value})`
+import type { CountryType } from '@dnb/eufemia/extensions/forms/Field/SelectCountry'
+
+// From the Field (internal value) to the data context or event parameter
+const transformOut = (internal: string, country: CountryType) => {
+  if (internal) {
+    return `${country.name} (${internal})`
   }
 }
-const transformIn = (value) => {
-  return String(value).match(/\((.*)\)/)?.[1]
+
+// To the Field (from e.g. defaultValue)
+const transformIn = (external: unknown) => {
+  return String(external).match(/\((.*)\)/)?.[1] || 'NO'
 }
 ```
 

packages/dnb-design-system-portal/src/docs/uilib/extensions/forms/base-fields/String/Examples.tsx

@@ -466,10 +466,16 @@ export function TransformInAndOut() {
   return (
     <ComponentBox scope={{ Tools }}>
       {() => {
+        // From the Field (internal value) to the data context or event parameter
         const transformOut = (value) => {
           return { value, foo: 'bar' }
         }
+
+        // To the Field (from e.g. defaultValue)
         const transformIn = (data) => {
+          if (typeof data === 'string') {
+            return data
+          }
           return data?.value
         }
 

packages/dnb-design-system-portal/src/docs/uilib/extensions/forms/feature-fields/SelectCountry/Examples.tsx

@@ -101,11 +101,14 @@ export function TransformInAndOut() {
   return (
     <ComponentBox scope={{ Tools }}>
       {() => {
+        // From the Field (internal value) to the data context or event parameter
         const transformOut = (value, country) => {
           if (value) {
             return country
           }
         }
+
+        // To the Field (from e.g. defaultValue)
         const transformIn = (country) => {
           return country?.iso
         }

packages/dnb-design-system-portal/src/docs/uilib/extensions/forms/feature-fields/more-fields/Upload/info.mdx

@@ -92,3 +92,71 @@ async function virusCheck(newFiles) {
   return await Promise.all(promises)
 }
 ```
+
+### TransformIn and TransformOut
+
+You can use the `transformIn` and `transformOut` properties to transform the data from the internal format to the external format and vice versa.
+
+```tsx
+import { Form, Field, Tools } from '@dnb/eufemia/extensions/forms'
+import type {
+  UploadValue,
+  UploadFileNative,
+} from '@dnb/eufemia/extensions/forms/Field/Upload'
+
+// Our external format
+type DocumentMetadata = {
+  id: string
+  fileName: string
+}
+
+const defaultValue = [
+  {
+    id: '1234',
+    fileName: 'myFile.pdf',
+  },
+] satisfies DocumentMetadata[] as unknown as UploadValue
+
+const filesCache = new Map<string, File>()
+
+// To the Field (from e.g. defaultValue)
+const transformIn = (external?: DocumentMetadata[]) => {
+  return (
+    external?.map(({ id, fileName }) => {
+      const file: File =
+        filesCache.get(id) ||
+        new File([], fileName, { type: 'images/png' })
+
+      return { id, file }
+    }) || []
+  )
+}
+
+// From the Field (internal value) to the data context or event parameter
+const transformOut = (internal?: UploadValue) => {
+  return (
+    internal?.map(({ id, file }) => {
+      if (!filesCache.has(id)) {
+        filesCache.set(id, file)
+      }
+
+      return { id, fileName: file.name }
+    }) || []
+  )
+}
+
+function MyForm() {
+  return (
+    <Form.Handler>
+      <Field.Upload
+        path="/documents"
+        transformIn={transformIn}
+        transformOut={transformOut}
+        defaultValue={defaultValue}
+      />
+
+      <Tools.Log />
+    </Form.Handler>
+  )
+}
+```

packages/dnb-design-system-portal/src/docs/uilib/extensions/forms/getting-started.mdx

@@ -284,20 +284,20 @@ You may check out an [interactive example](/uilib/extensions/forms/Form/Handler/
 
 #### Transforming data
 
-Each [field](/uilib/extensions/forms/all-fields/) and [value](/uilib/extensions/forms/Value/) component supports transformer functions. These functions allow you to transform a value before it is processed into the form data object and vice versa:
+Each [Field.\*](/uilib/extensions/forms/all-fields/) and [Value.\*](/uilib/extensions/forms/Value/) component supports transformer functions.
+
+These functions allow you to manipulate the field value to a different format than it uses internally and vice versa.
 
 ```tsx
 <Field.String
   path="/myField"
-  transformIn={transformIn}
   transformOut={transformOut}
+  transformIn={transformIn}
 />
 ```
 
-This allows you to show a value in a different format than it is stored in the form data object.
-
-- `transformIn` (in to the field or value) transforms the internal value before it is displayed.
-- `transformOut` (out of the field) transforms the internal value before it gets forwarded to the data context or returned as e.g. the `onChange` value parameter.
+- `transformOut` (out of the `Field.*` component) transforms the internal value before it gets forwarded to the data context or returned as e.g. the `onChange` value parameter.
+- `transformIn` (in to the `Field.*` or `Value.*` component) transforms the external value before it is displayed and used internally.
 
 <Examples.Transformers />
 
@@ -311,14 +311,18 @@ You can achieve this by using the `transformIn` and `transformOut` functions:
 
 ```tsx
 import { Field } from '@dnb/eufemia/extensions/forms'
+import type { CountryType } from '@dnb/eufemia/extensions/forms/Field/SelectCountry'
 
-const transformOut = (value, country) => {
-  if (value) {
+// From the Field (internal value) to the data context or event parameter
+const transformOut = (internal, country) => {
+  if (internal) {
     return country
   }
 }
-const transformIn = (country) => {
-  return country?.iso
+
+// To the Field (from e.g. defaultValue)
+const transformIn = (external: CountryType) => {
+  return external?.iso || 'NO'
 }
 
 const MyForm = () => {

packages/dnb-eufemia/src/extensions/forms/Field/SelectCountry/SelectCountry.tsx

@@ -23,6 +23,7 @@ export type CountryFilterSet =
   | 'Nordic'
   | 'Europe'
   | 'Prioritized'
+export type { CountryType }
 
 export type Props = FieldPropsWithExtraValue<
   string,

packages/dnb-eufemia/src/extensions/forms/Field/SelectCountry/__tests__/SelectCountry.test.tsx

@@ -391,11 +391,11 @@ describe('Field.SelectCountry', () => {
         return `${country.name} (${value})`
       }
     })
-    const transformIn = jest.fn((value) => {
-      return String(value).match(/\((.*)\)/)?.[1]
+    const transformIn = jest.fn((external) => {
+      return String(external).match(/\((.*)\)/)?.[1] || external
     })
-    const valueTransformIn = jest.fn((value) => {
-      return String(value).match(/\((.*)\)/)?.[1]
+    const valueTransformIn = jest.fn((internal) => {
+      return String(internal).match(/\((.*)\)/)?.[1]
     })
 
     const onSubmit = jest.fn()
@@ -434,7 +434,7 @@ describe('Field.SelectCountry', () => {
     }
 
     expect(transformOut).toHaveBeenCalledTimes(1)
-    expect(transformIn).toHaveBeenCalledTimes(4)
+    expect(transformIn).toHaveBeenCalledTimes(3)
     expect(valueTransformIn).toHaveBeenCalledTimes(2)
 
     const firstItemElement = () =>
@@ -452,7 +452,7 @@ describe('Field.SelectCountry', () => {
     )
 
     expect(transformOut).toHaveBeenCalledTimes(1)
-    expect(transformIn).toHaveBeenCalledTimes(5)
+    expect(transformIn).toHaveBeenCalledTimes(4)
     expect(valueTransformIn).toHaveBeenCalledTimes(3)
 
     expect(input).toHaveValue('Norge')
@@ -468,7 +468,7 @@ describe('Field.SelectCountry', () => {
     expect(value).toHaveTextContent('Sveits')
 
     expect(transformOut).toHaveBeenCalledTimes(4)
-    expect(transformIn).toHaveBeenCalledTimes(8)
+    expect(transformIn).toHaveBeenCalledTimes(6)
     expect(valueTransformIn).toHaveBeenCalledTimes(4)
 
     fireEvent.submit(form)
@@ -479,23 +479,21 @@ describe('Field.SelectCountry', () => {
     )
 
     expect(transformOut).toHaveBeenCalledTimes(4)
-    expect(transformIn).toHaveBeenCalledTimes(9)
+    expect(transformIn).toHaveBeenCalledTimes(7)
     expect(valueTransformIn).toHaveBeenCalledTimes(5)
 
     expect(transformOut).toHaveBeenNthCalledWith(1, 'NO', NO)
     expect(transformOut).toHaveBeenNthCalledWith(2, 'NO', NO)
     expect(transformOut).toHaveBeenNthCalledWith(3, 'CH', CH)
     expect(transformOut).toHaveBeenNthCalledWith(4, 'CH', CH)
 
-    expect(transformIn).toHaveBeenNthCalledWith(1, undefined)
-    expect(transformIn).toHaveBeenNthCalledWith(2, undefined)
+    expect(transformIn).toHaveBeenNthCalledWith(1, 'NO')
+    expect(transformIn).toHaveBeenNthCalledWith(2, 'NO')
     expect(transformIn).toHaveBeenNthCalledWith(3, 'Norge (NO)')
     expect(transformIn).toHaveBeenNthCalledWith(4, 'Norge (NO)')
     expect(transformIn).toHaveBeenNthCalledWith(5, 'Norge (NO)')
-    expect(transformIn).toHaveBeenNthCalledWith(6, 'Norge (NO)')
+    expect(transformIn).toHaveBeenNthCalledWith(6, 'Sveits (CH)')
     expect(transformIn).toHaveBeenNthCalledWith(7, 'Sveits (CH)')
-    expect(transformIn).toHaveBeenNthCalledWith(8, 'Sveits (CH)')
-    expect(transformIn).toHaveBeenNthCalledWith(9, 'Sveits (CH)')
 
     expect(valueTransformIn).toHaveBeenNthCalledWith(1, undefined)
     expect(valueTransformIn).toHaveBeenNthCalledWith(2, 'Norge (NO)')
@@ -504,6 +502,121 @@ describe('Field.SelectCountry', () => {
     expect(valueTransformIn).toHaveBeenNthCalledWith(5, 'Sveits (CH)')
   })
 
+  it('should support "transformIn" and "transformOut" when value is given by the data context', async () => {
+    const transformOut = jest.fn((value, country) => {
+      if (value) {
+        return `${country.name} (${value})`
+      }
+    })
+    const transformIn = jest.fn((external) => {
+      return String(external).match(/\((.*)\)/)?.[1]
+    })
+    const valueTransformIn = jest.fn((internal) => {
+      return String(internal).match(/\((.*)\)/)?.[1]
+    })
+
+    const onSubmit = jest.fn()
+
+    render(
+      <Form.Handler
+        onSubmit={onSubmit}
+        defaultData={{ country: 'Norge (NO)' }}
+      >
+        <Field.SelectCountry
+          path="/country"
+          transformIn={transformIn}
+          transformOut={transformOut}
+        />
+
+        <Value.SelectCountry
+          path="/country"
+          transformIn={valueTransformIn}
+        />
+      </Form.Handler>
+    )
+
+    const NO = {
+      cdc: '47',
+      continent: 'Europe',
+      i18n: { en: 'Norway', nb: 'Norge' },
+      iso: 'NO',
+      name: 'Norge',
+      regions: ['Scandinavia', 'Nordic'],
+    }
+
+    const CH = {
+      cdc: '41',
+      continent: 'Europe',
+      i18n: { en: 'Switzerland', nb: 'Sveits' },
+      iso: 'CH',
+      name: 'Sveits',
+    }
+
+    expect(transformOut).toHaveBeenCalledTimes(0)
+    expect(transformIn).toHaveBeenCalledTimes(1)
+    expect(valueTransformIn).toHaveBeenCalledTimes(1)
+
+    const firstItemElement = () =>
+      document.querySelectorAll('li.dnb-drawer-list__option')[0]
+
+    const form = document.querySelector('form')
+    const input = document.querySelector('input')
+    const value = document.querySelector('.dnb-forms-value-block__content')
+
+    fireEvent.submit(form)
+    expect(onSubmit).toHaveBeenCalledTimes(1)
+    expect(onSubmit).toHaveBeenLastCalledWith(
+      { country: 'Norge (NO)' },
+      expect.anything()
+    )
+
+    expect(transformOut).toHaveBeenCalledTimes(0)
+    expect(transformIn).toHaveBeenCalledTimes(2)
+    expect(valueTransformIn).toHaveBeenCalledTimes(2)
+
+    expect(input).toHaveValue('Norge')
+    expect(value).toHaveTextContent('Norge')
+
+    await userEvent.type(input, '{Backspace>10}Sveits')
+    await waitFor(() => {
+      expect(firstItemElement()).toBeInTheDocument()
+    })
+    await userEvent.click(firstItemElement())
+
+    expect(input).toHaveValue('Sveits')
+    expect(value).toHaveTextContent('Sveits')
+
+    expect(transformOut).toHaveBeenCalledTimes(3)
+    expect(transformIn).toHaveBeenCalledTimes(4)
+    expect(valueTransformIn).toHaveBeenCalledTimes(3)
+
+    fireEvent.submit(form)
+    expect(onSubmit).toHaveBeenCalledTimes(2)
+    expect(onSubmit).toHaveBeenLastCalledWith(
+      { country: 'Sveits (CH)' },
+      expect.anything()
+    )
+
+    expect(transformOut).toHaveBeenCalledTimes(3)
+    expect(transformIn).toHaveBeenCalledTimes(5)
+    expect(valueTransformIn).toHaveBeenCalledTimes(4)
+
+    expect(transformOut).toHaveBeenNthCalledWith(1, 'NO', NO)
+    expect(transformOut).toHaveBeenNthCalledWith(2, 'CH', CH)
+    expect(transformOut).toHaveBeenNthCalledWith(3, 'CH', CH)
+
+    expect(transformIn).toHaveBeenNthCalledWith(1, 'Norge (NO)')
+    expect(transformIn).toHaveBeenNthCalledWith(2, 'Norge (NO)')
+    expect(transformIn).toHaveBeenNthCalledWith(3, 'Norge (NO)')
+    expect(transformIn).toHaveBeenNthCalledWith(4, 'Sveits (CH)')
+    expect(transformIn).toHaveBeenNthCalledWith(5, 'Sveits (CH)')
+
+    expect(valueTransformIn).toHaveBeenNthCalledWith(1, 'Norge (NO)')
+    expect(valueTransformIn).toHaveBeenNthCalledWith(2, 'Norge (NO)')
+    expect(valueTransformIn).toHaveBeenNthCalledWith(3, 'Sveits (CH)')
+    expect(valueTransformIn).toHaveBeenNthCalledWith(4, 'Sveits (CH)')
+  })
+
   it('should store "displayValue" in data context', async () => {
     let dataContext = null