[Doc] Add gotcha about <Input disabled> usage and isDirty form state

docs/Features.md

@@ -426,6 +426,7 @@ React-admin offers a **rich set of input components and form layouts** to build
 
 For instance, here is how to build a tabbed form for editing a blog post:
 
+{% raw %}
 ```jsx
 import {
     TabbedForm,
@@ -445,7 +446,7 @@ export const PostEdit = () => (
     <Edit>
         <TabbedForm>
             <TabbedForm.Tab label="summary">
-                <TextInput disabled label="Id" source="id" />
+                <TextInput label="Id" source="id" InputProps={{ disabled: true }} />
                 <TextInput source="title" validate={required()} />
                 <TextInput multiline source="teaser" validate={required()} />
             </TabbedForm.Tab>
@@ -457,7 +458,7 @@ export const PostEdit = () => (
                 <DateInput label="Publication date" source="published_at" />
                 <NumberInput source="average_note" validate={[ number(), minValue(0) ]} />
                 <BooleanInput label="Allow comments?" source="commentable" defaultValue />
-                <TextInput disabled label="Nb views" source="views" />
+                <TextInput label="Nb views" source="views" InputProps={{ disabled: true }} />
             </TabbedForm.Tab>
             <TabbedForm.Tab label="comments">
                 <ReferenceManyField reference="comments" target="post_id" label={false}>
@@ -472,6 +473,7 @@ export const PostEdit = () => (
     </Edit>
 );
 ```
+{% endraw %}
 
 <video controls autoplay playsinline muted loop>
   <source src="./img/tabbed-form.webm" type="video/webm"/>

docs/Inputs.md

@@ -158,6 +158,14 @@ If `true`, the input is disabled and the user can't change the value.
 <TextInput source="title" disabled />
 ```
 
+**Tip**: The form framework used by react-admin, react-hook-form, [considers](https://github.com/react-hook-form/react-hook-form/pull/10805) that a `disabled` input shouldn't submit any value. So react-hook-form sets the value of all `disabled` inputs to `undefined`. As a consequence, a form with a `disabled` input is always considered `dirty` (i.e. react-hook-form considers that the form values and the initial record values are different), and it triggers [the `warnWhenUnsavedChanges` feature](./EditTutorial.md#warning-about-unsaved-changes) when leaving the form, even though the user changed nothing. The workaround is to set the `disabled` prop on the underlying input component, as follows:
+
+{% raw %}
+```jsx
+<TextInput source="title" InputProps={{ disabled: true }} />
+```
+{% endraw %}
+
 ## `format`
 
 The `format` prop accepts a callback taking the value from the form state, and returning the input value (which should be a string).

docs/Readme.md

@@ -82,13 +82,13 @@ const PostTitle = () => {
 export const PostEdit = () => (
     <Edit title={<PostTitle />}>
         <SimpleForm>
-            <TextInput disabled source="id" />
+            <TextInput source="id" InputProps={{ disabled: true }} />
             <TextInput source="title" />
             <TextInput source="teaser" options={{ multiline: true }} />
             <TextInput multiline source="body" />
             <DateInput label="Publication date" source="published_at" />
             <TextInput source="average_note" />
-            <TextInput disabled label="Nb views" source="views" />
+            <TextInput label="Nb views" source="views" InputProps={{ disabled: true }}/>
         </SimpleForm>
     </Edit>
 );

docs/Tutorial.md

@@ -703,12 +703,13 @@ export const App = () => (
 
 You can now adjust the `<PostEdit>` component to disable the edition of the primary key (`id`), place it first, and use a textarea for the `body` field, as follows:
 
+{% raw %}
 ```diff
 // in src/posts.tsx
 export const PostEdit = () => (
   <Edit>
     <SimpleForm>
-+     <TextInput source="id" disabled />
++     <TextInput source="id" InputProps={{ disabled: true }} />
       <ReferenceInput source="userId" reference="users" link="show" />
 -     <TextInput source="id" />
       <TextInput source="title" />
@@ -718,6 +719,7 @@ export const PostEdit = () => (
   </Edit>
 );
 ```
+{% endraw %}
 
 If you've understood the `<List>` component, the `<Edit>` component will be no surprise. It's responsible for fetching the record, and displaying the page title. It passes the record down to the `<SimpleForm>` component, which is responsible for the form layout, default values, and validation. Just like `<Datagrid>`, `<SimpleForm>` uses its children to determine the form inputs to display. It expects *input components* as children. `<TextInput>` and `<ReferenceInput>` are such inputs.
 

examples/simple/src/comments/CommentEdit.tsx

@@ -129,7 +129,11 @@ const CommentEdit = props => {
                             onSubmit={save}
                             warnWhenUnsavedChanges
                         >
-                            <TextInput disabled source="id" fullWidth />
+                            <TextInput
+                                source="id"
+                                fullWidth
+                                InputProps={{ disabled: true }}
+                            />
                             <ReferenceInput
                                 source="post_id"
                                 reference="posts"

examples/simple/src/posts/PostEdit.tsx

@@ -116,7 +116,10 @@ const PostEdit = () => {
                         justifyContent="space-between"
                         fullWidth
                     >
-                        <TextInput disabled source="id" />
+                        <TextInput
+                            InputProps={{ disabled: true }}
+                            source="id"
+                        />
                         <TextInput
                             source="title"
                             validate={required()}
@@ -224,7 +227,7 @@ const PostEdit = () => {
                         validate={[required(), number(), minValue(0)]}
                     />
                     <BooleanInput source="commentable" defaultValue />
-                    <TextInput disabled source="views" />
+                    <TextInput InputProps={{ disabled: true }} source="views" />
                     <ArrayInput source="pictures">
                         <SimpleFormIterator>
                             <TextInput source="url" defaultValue="" />

examples/simple/src/users/UserEdit.tsx

@@ -66,7 +66,9 @@ const UserEditForm = () => {
             onSubmit={newSave}
         >
             <TabbedForm.Tab label="user.form.summary" path="">
-                {permissions === 'admin' && <TextInput disabled source="id" />}
+                {permissions === 'admin' && (
+                    <TextInput source="id" InputProps={{ disabled: true }} />
+                )}
                 <TextInput
                     source="name"
                     defaultValue="slim shady"