Lua Beginners FAQ - Revision history

Picassoct: /* Complex Lifecycles */

2021-12-12T09:36:00Z

Complex Lifecycles

← Older revision		Revision as of 10:36, 12 December 2021
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	Due to the complexity of the simulation, spring scripts are burdened with the curse of complex lifecyles very similar to https://en.wikipedia.org/wiki/Object_lifetime in programing.		Due to the complexity of the simulation, spring scripts are burdened with the curse of complex lifecyles very similar to https://en.wikipedia.org/wiki/Object_lifetime in programing.

	This means, you can not rely on any ~~stored data~~ being valid after as little as 1 frame has passed. Units may have been captured, destroyed or created in this time.		This means, you can not rely on any information about the simulation being valid after as little as 1 frame has passed. Units may have been captured, destroyed or created in this time. Terrain may have been altered.

	People usually combat this by creating large amounts of protective boiler plate, checking if a unit still exists, is still on the same team, etc. every time a unitscript, gadget or widget wakes up.		People usually combat this by creating large amounts of protective boiler plate, checking if a unit still exists, is still on the same team, etc. every time a unitscript, gadget or widget wakes up.

	==Where can I find/edit examples?==		==Where can I find/edit examples?==

Picassoct at 09:33, 12 December 2021

2021-12-12T09:33:55Z

← Older revision		Revision as of 10:33, 12 December 2021
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	*add custom parameters to CEG definitions.		*add custom parameters to CEG definitions.

			==Complex Lifecycles==

			Due to the complexity of the simulation, spring scripts are burdened with the curse of complex lifecyles very similar to https://en.wikipedia.org/wiki/Object_lifetime in programing.

			This means, you can not rely on any stored data being valid after as little as 1 frame has passed. Units may have been captured, destroyed or created in this time.

			People usually combat this by creating large amounts of protective boiler plate, checking if a unit still exists, is still on the same team, etc. every time a unitscript, gadget or widget wakes up.

	==Where can I find/edit examples?==		==Where can I find/edit examples?==

Flozi: /* What is the difference between LuaUI, LuaRules, widgets and gadgets? */ update links

2017-12-26T12:18:15Z

What is the difference between LuaUI, LuaRules, widgets and gadgets?: update links

← Older revision		Revision as of 13:18, 26 December 2017
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	==What is the difference between LuaUI, LuaRules, widgets and gadgets?==		==What is the difference between LuaUI, LuaRules, widgets and gadgets?==

	Spring allows various [[:~~Category:Lua~~\|Lua ~~States~~]], each with differing functionality. Inside each Lua ~~state~~, developers can write addons, which are self-contained pieces of code. There is:		Spring allows various [[Lua:Environments\|Lua Environments]], each with differing functionality. Inside each Lua environment, developers can write addons, which are self-contained pieces of code. There are:
	* <b>LuaUI</b>: Used for unsynced GUI related code. Addons in here are often called widgets. Clients can (if the game permits it) control which widgets are running. Widgets contain only unsynced code. They can be bundled inside the game, or loaded from the users "Spring/LuaUI/Wigets" directory.		* <b>LuaUI</b>: Used for unsynced GUI related code. Addons in here are often called widgets. Clients can (if the game permits it) control which widgets are running. Widgets contain only unsynced code. They can be bundled inside the game, or loaded from the users "Spring/LuaUI/Wigets" directory.
	* <b>LuaRules</b>: Addons in here are often called gadgets. Clients cannot choose which gadgets run. Gadgets can include both synced and unsynced code, and must be bundled inside the game.		* <b>LuaRules</b>: Addons in here are often called gadgets. Clients cannot choose which gadgets run. Gadgets can include both synced and unsynced code, and must be bundled inside the game.

	Intended for mappers, there is also LuaGaia, which behaves like LuaRules but is ~~seperated~~ from it. To see which of the lua ~~states~~ has access to which data/functionality, see [[:~~Category:Lua\|Lua States~~]] and [[Lua:Callins]].		Intended for mappers, there is also LuaGaia, which behaves like LuaRules but is separated from it. To see which of the lua environoments has access to which data/functionality, see [[Lua:Environments#Interfaces]] and [[Lua:Callins]].


	==What can't Lua do in the current version of Spring?==		==What can't Lua do in the current version of Spring?==

Paulomorfeo: Case problem in the paths, ruining Linux paths

2016-01-18T22:51:16Z

Case problem in the paths, ruining Linux paths

← Older revision		Revision as of 23:51, 18 January 2016
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	After that, you could look at the example widget [[Lua:Tutorial_GettingStarted\|here]], and try to add some functionality of your own!		After that, you could look at the example widget [[Lua:Tutorial_GettingStarted\|here]], and try to add some functionality of your own!

	Once you're a pro, have a look at the game repos [https://springrts.com/wiki/Gamedev:PublicRepos here], especially their /luaui/~~widgets~~ and /luarules/gadgets dirs.		Once you're a pro, have a look at the game repos [https://springrts.com/wiki/Gamedev:PublicRepos here], especially their /luaui/Widgets and /luarules/gadgets dirs.

	==Where can I find help?==		==Where can I find help?==
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	==Where can I find/edit examples?==		==Where can I find/edit examples?==

	You can find some easy example widgets [[Lua:Tutorial_GettingStarted\|here]]. The best source of more complicated examples is inside games themselves, in the LuaUI/~~widgets~~ and Luarules/gadgets directories. See [[Gamedev:PublicRepos]] for a list of repositories.		You can find some easy example widgets [[Lua:Tutorial_GettingStarted\|here]]. The best source of more complicated examples is inside games themselves, in the LuaUI/Widgets and Luarules/gadgets directories. See [[Gamedev:PublicRepos]] for a list of repositories.

	To make your own widgets, simply place individual .lua files into your Spring/LuaUI/~~widgets~~ dir (create the dir if it is not present). Game repositories can be checked out into a folder named "SomeAwesomeGame.sdd", placed in your "/Spring/games" dir; this shoudl give a local copy of the game, recognized by Spring, where you can edit files. Make sure to check the licenses before doing this!		To make your own widgets, simply place individual .lua files into your Spring/LuaUI/Widgets dir (create the dir if it is not present. Case-sensitive!!!). Game repositories can be checked out into a folder named "SomeAwesomeGame.sdd", placed in your "/Spring/games" dir; this shoudl give a local copy of the game, recognized by Spring, where you can edit files. Make sure to check the licenses before doing this!

Abma: /* How do I open ".lua" files? */

2015-09-28T20:08:27Z

How do I open ".lua" files?

← Older revision		Revision as of 21:08, 28 September 2015
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	==How do I open ".lua" files?==		==How do I open ".lua" files?==

	Any text editor is enough. [http://notepad-plus.sourceforge.net/uk/site.htm Notepad++] ~~is free, multi-platform and highly recommended~~. There are also IDEs able to work with Lua, such as Eclipse, if you look for them.		Any text editor is enough. On Windows i.e. use [http://notepad-plus.sourceforge.net/uk/site.htm Notepad++]. There are also IDEs able to work with Lua, such as Eclipse, if you look for them.


	==What is a call-in? And a call-out?==		==What is a call-in? And a call-out?==

Silentwings: /* Where should I start? */

2015-08-23T00:17:58Z

Where should I start?

← Older revision		Revision as of 01:17, 23 August 2015
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	After that, you could look at the example widget [[Lua:Tutorial_GettingStarted\|here]], and try to add some functionality of your own!		After that, you could look at the example widget [[Lua:Tutorial_GettingStarted\|here]], and try to add some functionality of your own!

			Once you're a pro, have a look at the game repos [https://springrts.com/wiki/Gamedev:PublicRepos here], especially their /luaui/widgets and /luarules/gadgets dirs.

	==Where can I find help?==		==Where can I find help?==

Silentwings: /* Can I reload a script without restarting Spring? */

2015-08-16T11:27:36Z

Can I reload a script without restarting Spring?

← Older revision		Revision as of 12:27, 16 August 2015
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	==Can I reload a script without restarting Spring?==		==Can I reload a script without restarting Spring?==

	Yes, you can type "/luaui reload" to reload widgets, and if you have "cheats" enabled you can also "/luarules reload".		Yes, you can type "/luaui reload" to reload widgets, and if you have "cheats" enabled you can also "/luarules reload" to reload gadgets.


	==Why does the print function seem to do nothing?==		==Why does the print function seem to do nothing?==

Silentwings at 11:24, 16 August 2015

2015-08-16T11:24:58Z

← Older revision		Revision as of 12:24, 16 August 2015
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	This page only tries to answer general questions, for more specific Questions please ask in the forum.		This page is an introduction to using Lua in Spring - it only tries to answer general questions, for more specific Questions please ask in the forum.


			==Where should I start?==
	==~~I'm interested in learning to use Lua with Spring.~~ Where should I start?==

	You can start by reading general Lua tutorials [http://lua-users.org/wiki/LuaTutorial here].		You can start by reading general Lua tutorials [http://lua-users.org/wiki/LuaTutorial here].
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	==Where can I find help?==		==Where can I find help?==

	You can find documentation on the [[Lua_Scripting\|Lua_Scripting]] page. Discussion of lua coding takes place on the [https://springrts.com/wiki/Read_Me_First lobby] in #moddev and #lua, and there is also a [https://springrts.com/phpbb/viewforum.php?f=23 Lua sub-forum].		You can find documentation of Springs Lua API on the [[Lua_Scripting\|Lua_Scripting]] page. Discussion of lua coding takes place on the [https://springrts.com/wiki/Read_Me_First lobby] in #moddev and #lua, and there is also a [https://springrts.com/phpbb/viewforum.php?f=23 Lua sub-forum].

Silentwings: paragraphing

2015-08-14T05:27:04Z

paragraphing

Silentwings: /* What is the difference between a unsynced and synced lua code? */

2015-08-14T05:25:53Z

What is the difference between a unsynced and synced lua code?

← Older revision		Revision as of 06:25, 14 August 2015
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	Call-outs are functions defined in Spring you can run at whichever moment you desire. For example, when you call Spring.GetUnitTeam(unitID), the engine returns the teamID of the unit identified by "unitID".		Call-outs are functions defined in Spring you can run at whichever moment you desire. For example, when you call Spring.GetUnitTeam(unitID), the engine returns the teamID of the unit identified by "unitID".

	==What is the difference between a unsynced and synced lua code?==		==What is the difference between unsynced and synced lua code?==

	Synced code is code that runs, identically and at the same time, on every connected client. In practice, this means code which controls the game state. Unsynced code is code that will run differently (or maybe not at all) on each connected client. Typically, this means the user interface.		Synced code is code that runs, identically and at the same time, on every connected client. In practice, this means code which controls the game state. Unsynced code is code that will run differently (or maybe not at all) on each connected client. Typically, this means the user interface.

← Older revision		Revision as of 06:27, 14 August 2015
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	You can find documentation on the [[Lua_Scripting\|Lua_Scripting]] page. Discussion of lua coding takes place on the [https://springrts.com/wiki/Read_Me_First lobby] in #moddev and #lua, and there is also a [https://springrts.com/phpbb/viewforum.php?f=23 Lua sub-forum].		You can find documentation on the [[Lua_Scripting\|Lua_Scripting]] page. Discussion of lua coding takes place on the [https://springrts.com/wiki/Read_Me_First lobby] in #moddev and #lua, and there is also a [https://springrts.com/phpbb/viewforum.php?f=23 Lua sub-forum].


	==How do I open ".lua" files?==		==How do I open ".lua" files?==
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	Call-ins are functions defined in your script that Spring calls when a determined event takes place. For example, the widget:Initialize() call-in is run by Spring when the widget is loaded.		Call-ins are functions defined in your script that Spring calls when a determined event takes place. For example, the widget:Initialize() call-in is run by Spring when the widget is loaded.
	Call-outs are functions defined in Spring you can run at whichever moment you desire. For example, when you call Spring.GetUnitTeam(unitID), the engine returns the teamID of the unit identified by "unitID".		Call-outs are functions defined in Spring you can run at whichever moment you desire. For example, when you call Spring.GetUnitTeam(unitID), the engine returns the teamID of the unit identified by "unitID".


	==What is the difference between unsynced and synced lua code?==		==What is the difference between unsynced and synced lua code?==
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	For example, lua code to make units explode if they fell down a cliff would need to be synced. But, code that warned a player when one of their own units was getting near a cliff edge, would need to be unsynced.		For example, lua code to make units explode if they fell down a cliff would need to be synced. But, code that warned a player when one of their own units was getting near a cliff edge, would need to be unsynced.


	==What is the difference between LuaUI, LuaRules, widgets and gadgets?==		==What is the difference between LuaUI, LuaRules, widgets and gadgets?==
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	Intended for mappers, there is also LuaGaia, which behaves like LuaRules but is seperated from it. To see which of the lua states has access to which data/functionality, see [[:Category:Lua\|Lua States]] and [[Lua:Callins]].		Intended for mappers, there is also LuaGaia, which behaves like LuaRules but is seperated from it. To see which of the lua states has access to which data/functionality, see [[:Category:Lua\|Lua States]] and [[Lua:Callins]].


	==What can't Lua do in the current version of Spring?==		==What can't Lua do in the current version of Spring?==
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	To make your own widgets, simply place individual .lua files into your Spring/LuaUI/widgets dir (create the dir if it is not present). Game repositories can be checked out into a folder named "SomeAwesomeGame.sdd", placed in your "/Spring/games" dir; this shoudl give a local copy of the game, recognized by Spring, where you can edit files. Make sure to check the licenses before doing this!		To make your own widgets, simply place individual .lua files into your Spring/LuaUI/widgets dir (create the dir if it is not present). Game repositories can be checked out into a folder named "SomeAwesomeGame.sdd", placed in your "/Spring/games" dir; this shoudl give a local copy of the game, recognized by Spring, where you can edit files. Make sure to check the licenses before doing this!


	==Can I reload a script without restarting Spring?==		==Can I reload a script without restarting Spring?==