Independent "Submit" button for tabbed form in Create - admin-on-rest

Question

I already made 2 types of create page:
Create single record.
Import multiple records from xlsx file.
Now I want to implement 2 independent buttons:
Save
Import
meaning that when I click on button 1, only button 1 works.
Here is my code:
<Create {...this.props}>
<TabbedForm toolbar="">
<FormTab label="Single record">
<ReferenceInput label="Centre" source="centre" reference="centre" sort={{ field: 'name', order: 'ASC' }} allowEmpty>
<SelectInput optionText="name" />
</ReferenceInput>
<TextInput source="fullname" />
<TextInput source="serial " />
<TextInput source="birthday" />
<TextInput source="join_date" />
<TextInput source="remark" />
<SaveButton label="Save" redirect="show" submitOnEnter={true} />
</FormTab>
<FormTab label="Import from xlsx">
<ReferenceInput label="Centre" source="centre_import" reference="centre" sort={{ field: 'name', order: 'ASC' }} allowEmpty>
<SelectInput optionText="name" />
</ReferenceInput>
<label id="customLabel">
<input id="upload" ref={(input) => { this.textInput = input; }} type="file" hidden
onClick={(event)=> {
event.target.value = null;
}}
onChange={
(event) => {
this.fileName.textContent = event.target.files[0].name;
}
}
/>
<FlatButton primary label="Select file" icon={<ActionFile />} onClick={() => {
this.textInput.click();
}}/>
<span id="fileName" ref={(span) => { this.fileName = span; }}></span>
</label>
<SaveButton label="Import" redirect={false} submitOnEnter={true} />
</FormTab>
</TabbedForm>
</Create>

Answer 1

The easiest way would be to keep a single button here. You may add a text inside the importation tab explaining that clicking on save will import the file.
However, you still have to deal with the redirection. To do so, you'll have to implement a custom SaveButton:
Copy the code of the default SaveButton into a SaveOrImportButton file.
Update its mapStateToProps function and use redux-form getFormValues selector to inspect the form values and determine whether its an importation.
Use this knowledge to customize the button:
You may update the label to Import if the user selected a file. The label will update immediately after the file field gets dirty.
You can change the redirect value at L22.
Use this button inside a Toolbar component and pass this component to the toolbar prop of the Create component.