Remodel formDataEntryValue

Author: nojaf

src/FetchAPI.res

@@ -218,7 +218,8 @@ type formData = {}
 
 type requestInfo = any
 
-type formDataEntryValue = any
+@editor.completeFrom(FormDataEntryValue)
+type formDataEntryValue
 
 type requestInit = {
   /**

src/FetchAPI/FormData.res

@@ -31,13 +31,7 @@ external delete: (formData, string) => unit = "delete"
 [Read more on MDN](https://developer.mozilla.org/docs/Web/API/FormData/get)
 */
 @send
-external get: (formData, string) => null<string> = "get"
-
-/**
-[Read more on MDN](https://developer.mozilla.org/docs/Web/API/FormData/get)
-*/
-@send
-external getFile: (formData, string) => null<file> = "get"
+external get: (formData, string) => null<formDataEntryValue> = "get"
 
 /**
 [Read more on MDN](https://developer.mozilla.org/docs/Web/API/FormData/getAll)

src/FetchAPI/FormDataEntryValue.js

@@ -0,0 +1,22 @@
+open Prelude
+open FetchAPI
+open FileAPI
+
+external fromString: string => formDataEntryValue = "%identity"
+external fromFile: file => formDataEntryValue = "%identity"
+
+/**
+Represents a decoded version of the abstract `formDataEntryValue` type.
+A FormData entry value is either a string or a File.
+*/
+type decoded =
+  | String(string)
+  | File(file)
+
+let decode = (t: formDataEntryValue): decoded => {
+  if File.isInstanceOf(t) {
+    File(unsafeConversation(t))
+  } else {
+    String(unsafeConversation(t))
+  }
+}

src/FetchAPI/FormDataEntryValue.res

@@ -11,3 +11,5 @@ external make: (
   ~fileName: string,
   ~options: filePropertyBag=?,
 ) => file = "File"
+
+let isInstanceOf = (_: 't): bool => %raw(`param instanceof File`)

src/FileAPI/File.js

@@ -3,5 +3,31 @@
 external myForm: DOMAPI.htmlFormElement = "myForm"
 
 let formData = FormData.make(~form=myForm)
-let phone: null<string> = formData->FormData.get("phone")
-let image: null<FileAPI.file> = formData->FormData.getFile("image")
+
+// Get a form field - returns formDataEntryValue which could be string or File
+let phoneEntry: null<FetchAPI.formDataEntryValue> = formData->FormData.get("phone")
+
+// Decode the entry to handle both string and File cases
+let _ = switch phoneEntry->Null.toOption {
+| None => Console.log("No phone field")
+| Some(entry) =>
+  switch entry->FormDataEntryValue.decode {
+  | FormDataEntryValue.String(value) => Console.log(`Phone: ${value}`)
+  | FormDataEntryValue.File(file) => Console.log(`Unexpected file: ${file.name}`)
+  }
+}
+
+// Get all values for a field (useful for multi-select or multiple file inputs)
+let allImages: array<FetchAPI.formDataEntryValue> = formData->FormData.getAll("images")
+
+// Process all entries
+let _ = allImages->Array.forEach(entry => {
+  switch entry->FormDataEntryValue.decode {
+  | FormDataEntryValue.String(value) => Console.log(`String value: ${value}`)
+  | FormDataEntryValue.File(file) => Console.log(`File: ${file.name}`)
+  }
+})
+
+// Create formDataEntryValue from string or file
+let stringEntry = FormDataEntryValue.fromString("test value")
+let fileEntry = FormDataEntryValue.fromFile(File.make(~fileBits=[], ~fileName="test.txt"))