[3.x] [HTML5] Add easy to use download API.

doc/classes/JavaScript.xml

@@ -31,6 +31,22 @@
 				Creates a new JavaScript object using the [code]new[/code] constructor. The [code]object[/code] must a valid property of the JavaScript [code]window[/code]. See [JavaScriptObject] for usage.
 			</description>
 		</method>
+		<method name="download_buffer">
+			<return type="void">
+			</return>
+			<argument index="0" name="buffer" type="PoolByteArray">
+			</argument>
+			<argument index="1" name="name" type="String">
+			</argument>
+			<argument index="2" name="mime" type="String" default="&quot;application/octet-stream&quot;">
+			</argument>
+			<description>
+				Prompts the user to download a file containing the specified [code]buffer[/code]. The file will have the given [code]name[/code] and [code]mime[/code] type.
+				[b]Note:[/b] The browser may override the [url=https://en.wikipedia.org/wiki/Media_type]MIME type[/url] provided based on the file [code]name[/code]'s extension.
+				[b]Note:[/b] Browsers might block the download if [method download_buffer] is not being called from a user interaction (e.g. button click).
+				[b]Note:[/b] Browsers might ask the user for permission or block the download if multiple download requests are made in a quick succession.
+			</description>
+		</method>
 		<method name="eval">
 			<return type="Variant">
 			</return>

platform/javascript/SCsub

@@ -22,8 +22,6 @@ sys_env.AddJSLibraries(
     ]
 )
 
-if env["tools"]:
-    sys_env.AddJSLibraries(["js/libs/library_godot_editor_tools.js"])
 if env["javascript_eval"]:
     sys_env.AddJSLibraries(["js/libs/library_godot_javascript_singleton.js"])
 

platform/javascript/api/api.cpp

@@ -70,6 +70,7 @@ void JavaScript::_bind_methods() {
 		mi.arguments.push_back(PropertyInfo(Variant::STRING, "object"));
 		ClassDB::bind_vararg_method(METHOD_FLAGS_DEFAULT, "create_object", &JavaScript::_create_object_bind, mi);
 	}
+	ClassDB::bind_method(D_METHOD("download_buffer", "buffer", "name", "mime"), &JavaScript::download_buffer, DEFVAL("application/octet-stream"));
 }
 
 #if !defined(JAVASCRIPT_ENABLED) || !defined(JAVASCRIPT_EVAL_ENABLED)
@@ -100,3 +101,7 @@ Variant JavaScript::_create_object_bind(const Variant **p_args, int p_argcount,
 	return Ref<JavaScriptObject>();
 }
 #endif
+#if !defined(JAVASCRIPT_ENABLED)
+void JavaScript::download_buffer(Vector<uint8_t> p_arr, const String &p_name, const String &p_mime) {
+}
+#endif

platform/javascript/api/javascript_singleton.h

@@ -58,6 +58,7 @@ class JavaScript : public Object {
 	Ref<JavaScriptObject> get_interface(const String &p_interface);
 	Ref<JavaScriptObject> create_callback(Object *p_ref, const StringName &p_method);
 	Variant _create_object_bind(const Variant **p_args, int p_argcount, Variant::CallError &r_error);
+	void download_buffer(Vector<uint8_t> p_arr, const String &p_name, const String &p_mime = "application/octet-stream");
 
 	static JavaScript *get_singleton();
 	JavaScript();

platform/javascript/api/javascript_tools_editor_plugin.cpp

@@ -41,7 +41,7 @@
 
 // JavaScript functions defined in library_godot_editor_tools.js
 extern "C" {
-extern void godot_js_editor_download_file(const char *p_path, const char *p_name, const char *p_mime);
+extern int godot_js_os_download_buffer(const uint8_t *p_buf, int p_buf_size, const char *p_name, const char *p_mime);
 }
 
 static void _javascript_editor_init_callback() {
@@ -70,7 +70,12 @@ void JavaScriptToolsEditorPlugin::_download_zip(Variant p_v) {
 	String base_path = resource_path.substr(0, resource_path.rfind("/")) + "/";
 	_zip_recursive(resource_path, base_path, zip);
 	zipClose(zip, NULL);
-	godot_js_editor_download_file("/tmp/project.zip", "project.zip", "application/zip");
+	FileAccess *f = FileAccess::open("/tmp/project.zip", FileAccess::READ);
+	ERR_FAIL_COND_MSG(!f, "Unable to create zip file");
+	Vector<uint8_t> buf;
+	buf.resize(f->get_len());
+	f->get_buffer(buf.ptrw(), buf.size());
+	godot_js_os_download_buffer(buf.ptr(), buf.size(), "project.zip", "application/zip");
 }
 
 void JavaScriptToolsEditorPlugin::_bind_methods() {

platform/javascript/javascript_singleton.cpp

@@ -302,6 +302,7 @@ union js_eval_ret {
 };
 
 extern int godot_js_eval(const char *p_js, int p_use_global_ctx, union js_eval_ret *p_union_ptr, void *p_byte_arr, void *p_byte_arr_write, void *(*p_callback)(void *p_ptr, void *p_ptr2, int p_len));
+extern int godot_js_os_download_buffer(const uint8_t *p_buf, int p_buf_size, const char *p_name, const char *p_mime);
 }
 
 void *resize_poolbytearray_and_open_write(void *p_arr, void *r_write, int p_len) {
@@ -338,3 +339,7 @@ Variant JavaScript::eval(const String &p_code, bool p_use_global_exec_context) {
 }
 
 #endif // JAVASCRIPT_EVAL_ENABLED
+
+void JavaScript::download_buffer(Vector<uint8_t> p_arr, const String &p_name, const String &p_mime) {
+	godot_js_os_download_buffer(p_arr.ptr(), p_arr.size(), p_name.utf8().get_data(), p_mime.utf8().get_data());
+}

platform/javascript/js/libs/library_godot_os.js

@@ -304,6 +304,23 @@ const GodotOS = {
 	godot_js_os_hw_concurrency_get: function () {
 		return navigator.hardwareConcurrency || 1;
 	},
+
+	godot_js_os_download_buffer__sig: 'viiii',
+	godot_js_os_download_buffer: function (p_ptr, p_size, p_name, p_mime) {
+		const buf = GodotRuntime.heapSlice(HEAP8, p_ptr, p_size);
+		const name = GodotRuntime.parseString(p_name);
+		const mime = GodotRuntime.parseString(p_mime);
+		const blob = new Blob([buf], { type: mime });
+		const url = window.URL.createObjectURL(blob);
+		const a = document.createElement('a');
+		a.href = url;
+		a.download = name;
+		a.style.display = 'none';
+		document.body.appendChild(a);
+		a.click();
+		a.remove();
+		window.URL.revokeObjectURL(url);
+	},
 };
 
 autoAddDeps(GodotOS, '$GodotOS');