From 80cb497de53c16fe1fa2156c8d9a460dec9dfd0f Mon Sep 17 00:00:00 2001
From: Matthias Le Brun <bloodyowl@icloud.com>
Date: Sat, 3 May 2025 16:26:47 +0200
Subject: [PATCH] proposal: make FormData more usable to get values

this **kinda** goes against the zero-cost philosophy, but I don't see a
world where users would not have to reimplement those.
---
 src/ReactDOM.bs.js | 39 ++++++++++++++++++++++++++++++++++++++-
 src/ReactDOM.res   | 35 ++++++++++++++++++++++++++++++++---
 2 files changed, 70 insertions(+), 4 deletions(-)

diff --git a/src/ReactDOM.bs.js b/src/ReactDOM.bs.js
index 06f42ca..fa51640 100644
--- a/src/ReactDOM.bs.js
+++ b/src/ReactDOM.bs.js
@@ -1,6 +1,7 @@
 // Generated by ReScript, PLEASE EDIT WITH CARE
 'use strict';
 
+var Caml_option = require("rescript/lib/js/caml_option.js");
 
 var Root = {};
 
@@ -8,7 +9,43 @@ var Client = {
   Root: Root
 };
 
-var $$FormData = {};
+function getString(formData, name) {
+  var value = formData.get(name);
+  if (!(value == null) && typeof value === "string") {
+    return Caml_option.some(value);
+  }
+  
+}
+
+function getFile(formData, name) {
+  var value = formData.get(name);
+  if (!(value == null) && typeof value !== "string") {
+    return Caml_option.some(value);
+  }
+  
+}
+
+function getAll(t, string) {
+  return t.getAll(string).map(function (value) {
+              if (typeof value === "string") {
+                return {
+                        TAG: "String",
+                        _0: value
+                      };
+              } else {
+                return {
+                        TAG: "File",
+                        _0: value
+                      };
+              }
+            });
+}
+
+var $$FormData = {
+  getString: getString,
+  getFile: getFile,
+  getAll: getAll
+};
 
 var Ref = {};
 
diff --git a/src/ReactDOM.res b/src/ReactDOM.res
index 160bb55..fbd564b 100644
--- a/src/ReactDOM.res
+++ b/src/ReactDOM.res
@@ -28,14 +28,43 @@ module Client = {
 // Very rudimentary form data bindings
 module FormData = {
   type t
-  type value
+  type file
+
+  type formValue =
+    | String(string)
+    | File(file)
 
   @new external make: unit => t = "FormData"
 
   @send external append: (t, string, ~filename: string=?) => unit = "append"
   @send external delete: (t, string) => unit = "delete"
-  @send external get: (t, string) => option<value> = "get"
-  @send external getAll: (t, string) => array<value> = "getAll"
+  @return(nullable) @send external getUnsafe: (t, string) => option<'a> = "get"
+  @send external getAllUnsafe: (t, string) => array<'a> = "getAll"
+
+  let getString = (formData, name) => {
+    switch formData->getUnsafe(name) {
+    | Some(value) => Js.typeof(value) === "string" ? Some(value) : None
+    | _ => None
+    }
+  }
+
+  external _asFile: 'a => file = "%identity"
+
+  let getFile = (formData, name) => {
+    switch formData->getUnsafe(name) {
+    | Some(value) => Js.typeof(value) === "string" ? None : Some(value->_asFile)
+    | _ => None
+    }
+  }
+
+  let getAll = (t, string) => {
+    t
+    ->getAllUnsafe(string)
+    ->Js.Array2.map(value => {
+      Js.typeof(value) === "string" ? String(value) : File(value->_asFile)
+    })
+  }
+
   @send external set: (string, string) => unit = "set"
   @send external has: string => bool = "has"
   // @send external keys: t => Iterator.t<string> = "keys";