Add HTTP API to main menu (#9998)

2 files changed, 192 insertions, 88 deletions

diff --git a/doc/fst_api.txt b/doc/fst_api.txt
index c8bcb1e91..6f9aa14b3 100644
--- a/doc/fst_api.txt
+++ b/doc/fst_api.txt
@@ -101,6 +101,9 @@ dialog_create(name, cbf_formspec, cbf_button_handler, cbf_events)
 ^ cbf_events: function to handle events
 	function(dialog, event)
 
+messagebox(name, message)
+^ creates a message dialog
+
 Class reference dialog:
 
 methods:
@@ -113,13 +116,13 @@ methods:
   ^ hide dialog
 - delete()
   ^ delete dialog from ui
-  
+
 members:
 - data
   ^ variable data attached to this dialog
 - parent
   ^ parent component to return to on exit
-  
+
 File: fst/buttonbar.lua
 -----------------------
 
diff --git a/doc/menu_lua_api.txt b/doc/menu_lua_api.txt
index 485c50110..4eccf5d10 100644
--- a/doc/menu_lua_api.txt
+++ b/doc/menu_lua_api.txt
@@ -3,34 +3,53 @@ Minetest Lua Mainmenu API Reference 5.3.0
 
 Introduction
 -------------
+
 The main menu is defined as a formspec by Lua in builtin/mainmenu/
 Description of formspec language to show your menu is in lua_api.txt
 
+
 Callbacks
 ---------
+
 core.buttonhandler(fields): called when a button is pressed.
 ^ fields = {name1 = value1, name2 = value2, ...}
 core.event_handler(event)
 ^ event: "MenuQuit", "KeyEnter", "ExitButton" or "EditBoxEnter"
 
+
 Gamedata
 --------
+
 The "gamedata" table is read when calling core.start(). It should contain:
 {
-	playername     = <name>,
-	password       = <password>,
-	address        = <IP/adress>,
-	port           = <port>,
-	selected_world = <index>, -- 0 for client mode
-	singleplayer   = <true/false>,
+    playername     = <name>,
+    password       = <password>,
+    address        = <IP/adress>,
+    port           = <port>,
+    selected_world = <index>, -- 0 for client mode
+    singleplayer   = <true/false>,
 }
 
+
 Functions
 ---------
+
 core.start()
 core.close()
+core.get_min_supp_proto()
+^ returns the minimum supported network protocol version
+core.get_max_supp_proto()
+^ returns the maximum supported network protocol version
+core.open_url(url)
+^ opens the URL in a web browser, returns false on failure.
+^ Must begin with http:// or https://
+core.get_version() (possible in async calls)
+^ returns current core version
+
+
+Filesystem
+----------
 
-Filesystem:
 core.get_builtin_path()
 ^ returns path to builtin root
 core.create_dir(absolute_path) (possible in async calls)
@@ -48,12 +67,6 @@ core.extract_zip(zipfile,destination) [unzip within path required]
 ^ zipfile to extract
 ^ destination folder to extract to
 ^ returns true/false
-core.download_file(url,target) (possible in async calls)
-^ url to download
-^ target to store to
-^ returns true/false
-core.get_version() (possible in async calls)
-^ returns current core version
 core.sound_play(spec, looped) -> handle
 ^ spec = SimpleSoundSpec (see lua-api.txt)
 ^ looped = bool
@@ -67,7 +80,82 @@ core.get_mapgen_names([include_hidden=false]) -> table of map generator algorith
     registered in the core (possible in async calls)
 core.get_cache_path() -> path of cache
 
-Formspec:
+
+HTTP Requests
+-------------
+
+* core.download_file(url, target) (possible in async calls)
+    * url to download, and target to store to
+    * returns true/false
+* `minetest.get_http_api()` (possible in async calls)
+    * returns `HTTPApiTable` containing http functions.
+    * The returned table contains the functions `fetch_sync`, `fetch_async` and
+      `fetch_async_get` described below.
+    * Function only exists if minetest server was built with cURL support.
+* `HTTPApiTable.fetch_sync(HTTPRequest req)`: returns HTTPRequestResult
+    * Performs given request synchronously
+* `HTTPApiTable.fetch_async(HTTPRequest req)`: returns handle
+    * Performs given request asynchronously and returns handle for
+      `HTTPApiTable.fetch_async_get`
+* `HTTPApiTable.fetch_async_get(handle)`: returns HTTPRequestResult
+    * Return response data for given asynchronous HTTP request
+
+### `HTTPRequest` definition
+
+Used by `HTTPApiTable.fetch` and `HTTPApiTable.fetch_async`.
+
+    {
+        url = "http://example.org",
+
+        timeout = 10,
+        -- Timeout for connection in seconds. Default is 3 seconds.
+
+        post_data = "Raw POST request data string" OR {field1 = "data1", field2 = "data2"},
+        -- Optional, if specified a POST request with post_data is performed.
+        -- Accepts both a string and a table. If a table is specified, encodes
+        -- table as x-www-form-urlencoded key-value pairs.
+        -- If post_data is not specified, a GET request is performed instead.
+
+        user_agent = "ExampleUserAgent",
+        -- Optional, if specified replaces the default minetest user agent with
+        -- given string
+
+        extra_headers = { "Accept-Language: en-us", "Accept-Charset: utf-8" },
+        -- Optional, if specified adds additional headers to the HTTP request.
+        -- You must make sure that the header strings follow HTTP specification
+        -- ("Key: Value").
+
+        multipart = boolean
+        -- Optional, if true performs a multipart HTTP request.
+        -- Default is false.
+    }
+
+### `HTTPRequestResult` definition
+
+Passed to `HTTPApiTable.fetch` callback. Returned by
+`HTTPApiTable.fetch_async_get`.
+
+    {
+        completed = true,
+        -- If true, the request has finished (either succeeded, failed or timed
+        -- out)
+
+        succeeded = true,
+        -- If true, the request was successful
+
+        timeout = false,
+        -- If true, the request timed out
+
+        code = 200,
+        -- HTTP status code
+
+        data = "response"
+    }
+
+
+Formspec
+--------
+
 core.update_formspec(formspec)
 core.get_table_index(tablename) -> index
 ^ can also handle textlists
@@ -82,7 +170,10 @@ core.explode_textlist_event(string) -> table
 core.set_formspec_prepend(formspec)
 ^ string to be added to every mainmenu formspec, to be used for theming.
 
-GUI:
+
+GUI
+---
+
 core.set_background(type, texturepath,[tile],[minsize])
 ^ type: "background", "overlay", "header" or "footer"
 ^ tile: tile the image instead of scaling (background only)
@@ -102,86 +193,96 @@ core.show_path_select_dialog(formname, caption, is_file_select)
 ^ returns nil or selected file/folder
 core.get_screen_info()
 ^ returns {
-	density         = <screen density 0.75,1.0,2.0,3.0 ... (dpi)>,
-	display_width   = <width of display>,
-	display_height  = <height of display>,
-	window_width    = <current window width>,
-	window_height   = <current window height>
-	}
+    density         = <screen density 0.75,1.0,2.0,3.0 ... (dpi)>,
+    display_width   = <width of display>,
+    display_height  = <height of display>,
+    window_width    = <current window width>,
+    window_height   = <current window height>
+    }
 
-### Content and Packages
+
+Content and Packages
+--------------------
 
 Content - an installed mod, modpack, game, or texture pack (txt)
 Package - content which is downloadable from the content db, may or may not be installed.
 
 * core.get_modpath() (possible in async calls)
-	* returns path to global modpath
+    * returns path to global modpath
 * core.get_clientmodpath() (possible in async calls)
-	* returns path to global client-side modpath
+    * returns path to global client-side modpath
 * core.get_gamepath() (possible in async calls)
-	* returns path to global gamepath
+    * returns path to global gamepath
 * core.get_texturepath() (possible in async calls)
-	* returns path to default textures
+    * returns path to default textures
 * core.get_game(index)
-	* returns:
-
-		{
-			id               = <id>,
-			path             = <full path to game>,
-			gamemods_path    = <path>,
-			name             = <name of game>,
-			menuicon_path    = <full path to menuicon>,
-			author           = "author",
-			DEPRECATED:
-			addon_mods_paths = {[1] = <path>,},
-		}
+    * returns:
+
+        {
+            id               = <id>,
+            path             = <full path to game>,
+            gamemods_path    = <path>,
+            name             = <name of game>,
+            menuicon_path    = <full path to menuicon>,
+            author           = "author",
+            DEPRECATED:
+            addon_mods_paths = {[1] = <path>,},
+        }
 
 * core.get_games() -> table of all games in upper format (possible in async calls)
 * core.get_content_info(path)
-	* returns
+    * returns
 
-		{
-			name             = "name of content",
-			type             = "mod" or "modpack" or "game" or "txp",
-			description      = "description",
-			author           = "author",
-			path             = "path/to/content",
-			depends          = {"mod", "names"}, -- mods only
-			optional_depends = {"mod", "names"}, -- mods only
-		}
+        {
+            name             = "name of content",
+            type             = "mod" or "modpack" or "game" or "txp",
+            description      = "description",
+            author           = "author",
+            path             = "path/to/content",
+            depends          = {"mod", "names"}, -- mods only
+            optional_depends = {"mod", "names"}, -- mods only
+        }
 
 
-Favorites:
+Favorites
+---------
+
 core.get_favorites(location) -> list of favorites (possible in async calls)
 ^ location: "local" or "online"
 ^ returns {
-	[1] = {
-		clients       = <number of clients/nil>,
-		clients_max   = <maximum number of clients/nil>,
-		version       = <server version/nil>,
-		password      = <true/nil>,
-		creative      = <true/nil>,
-		damage        = <true/nil>,
-		pvp           = <true/nil>,
-		description   = <server description/nil>,
-		name          = <server name/nil>,
-		address       = <address of server/nil>,
-		port          = <port>
-		clients_list  = <array of clients/nil>
-		mods          = <array of mods/nil>
-	},
-	...
+    [1] = {
+        clients       = <number of clients/nil>,
+        clients_max   = <maximum number of clients/nil>,
+        version       = <server version/nil>,
+        password      = <true/nil>,
+        creative      = <true/nil>,
+        damage        = <true/nil>,
+        pvp           = <true/nil>,
+        description   = <server description/nil>,
+        name          = <server name/nil>,
+        address       = <address of server/nil>,
+        port          = <port>
+        clients_list  = <array of clients/nil>
+        mods          = <array of mods/nil>
+    },
+    ...
 }
 core.delete_favorite(id, location) -> success
 
-Logging:
+
+Logging
+-------
+
 core.debug(line) (possible in async calls)
 ^ Always printed to stderr and logfile (print() is redirected here)
 core.log(line) (possible in async calls)
 core.log(loglevel, line) (possible in async calls)
 ^ loglevel one of "error", "action", "info", "verbose"
 
-Settings:
+
+Settings
+--------
+
 core.settings:set(name, value)
 core.settings:get(name) -> string or nil (possible in async calls)
 core.settings:set_bool(name, value)
@@ -191,19 +292,25 @@ core.settings:save() -> nil, save all settings to config file
 For a complete list of methods of the Settings object see
 [lua_api.txt](https://github.com/minetest/minetest/blob/master/doc/lua_api.txt)
 
-Worlds:
+
+Worlds
+------
+
 core.get_worlds() -> list of worlds (possible in async calls)
 ^ returns {
-	[1] = {
-	path   = <full path to world>,
-	name   = <name of world>,
-	gameid = <gameid of world>,
-	},
+    [1] = {
+    path   = <full path to world>,
+    name   = <name of world>,
+    gameid = <gameid of world>,
+    },
 }
 core.create_world(worldname, gameid)
 core.delete_world(index)
 
-Helpers:
+
+Helpers
+-------
+
 core.get_us_time()
 ^ returns time with microsecond precision
 core.gettext(string) -> string
@@ -228,18 +335,10 @@ minetest.encode_base64(string) (possible in async calls)
 minetest.decode_base64(string) (possible in async calls)
 ^ Decodes a string encoded in base64.
 
-Version compat:
-core.get_min_supp_proto()
-^ returns the minimum supported network protocol version
-core.get_max_supp_proto()
-^ returns the maximum supported network protocol version
 
-Other:
-core.open_url(url)
-^ opens the URL in a web browser, returns false on failure.
-^ Must begin with http:// or https://
+Async
+-----
 
-Async:
 core.handle_async(async_job,parameters,finished)
 ^ execute a function asynchronously
 ^ async_job is a function receiving one parameter and returning one parameter
@@ -250,11 +349,13 @@ core.handle_async(async_job,parameters,finished)
 Limitations of Async operations
  -No access to global lua variables, don't even try
  -Limited set of available functions
-	e.g. No access to functions modifying menu like core.start,core.close,
-	core.show_path_select_dialog
+    e.g. No access to functions modifying menu like core.start,core.close,
+    core.show_path_select_dialog
+
 
 Background music
 ----------------
+
 The main menu supports background music.
 It looks for a `main_menu` sound in `$USER_PATH/sounds`. The same naming
 conventions as for normal sounds apply.