To send define a mutation in RTK Query that uses form data rather than a JSON payload, you need to use the undocumented formData attribute. This is useful for sending files to endpoints.
uploadSiteDocuments: build.mutation<{ file: string; uri: string }[], { files: File[] }>({
query: (body) => {
let formData = new FormData();
body.files.forEach((file) => {
formData.append(file.name, file);
});
return {
url: "site/documents",
method: "POST",
body: formData,
formData: true,
};
},
transformResponse: (response: any) => response.data,
}),
Do not change the encoding header as this is done automatically.