Extension:Scribunto/cs

Rozšíření Scribunto (Latin: "budou psát/nechají je psát (v budoucnu)") umožňuje vkládání skriptovací jazyky na MediaWiki.

V současnosti je jediným podporovaným skriptovacím jazykem Lua. Skripty Scriunto Lua se nacházejí ve jmenném prostoru zvaném Modul.

Licence
Toto rozšíření obsahuje kód licencovaný GNU General Public License v2.0 nebo novější (GPL-2.0+) a také kód licencovaný MIT License (MIT).

Požadavky


Kompatibilita PCRE verze
Doporučuje se PCRE 8.33+. PCRE 8.33 byla vydána v květnu 2013. Verzi PCRE používanou PHP můžete vidět na phpinfo webové stránce nebo z příkazového řádku pomocí následujícího příkazu:


 * Scriunto nebude fungovat s verzemi PCRE nižšími než 8.10.
 * PCRE 8.31 obsahuje chyby se vzorem JIT, který zkoumá, že rozbíjí různé vzory při použití s HHVM.
 * PCRE 8.32 obsahuje chybu, která způsobí odmítnutí určitých neznakových kódových bodů, což způsobí chyby v modulu mw.html.

CentOS 6 a RHEL 6 uvízly na PCRE 7 a je třeba je aktualizovat.

Aktualizace na 8.33 na serveru se starší verzí může být poměrně komplikovaná. Podrobnosti viz.

PHP pcntl (LTS)
Verze Scribunto pro MediaWiki 1.25 až 1.28 vyžadovaly PHP rozšíření pcntl, které je dostupné pouze na platformách Unix/Linux, pokud chcete používat "LuaStandalone" (tj. běžící v samostatném podřízeném procesu). Tento požadavek byl odstraněn v Scribunto pro MediaWiki 1.29.

Zda je podpora pcntl povolena, můžete zkontrolovat zobrazením webové stránky phpinfo nebo z příkazového řádku pomocí následujícího příkazu:



Rozšíření PHP mbstring
PHP potřebuje mít povolené rozšíření mbstring.

Zda je podpora mbstring povolena, můžete zkontrolovat zobrazením webové stránky phpinfo nebo z příkazového řádku pomocí následujícího příkazu:



Binární Lua


Balené binární soubory
Scribunto je dodáváno s binárními distribucemi Lua pro Linux (x86 a x86-64), Mac OS X Lion a Windows (32- a 64-bit).

Scribunto by vám mělo fungovat hned po vybalení, pokud:

P.S. Zkontrolujte svou verzi rozšíření a zjistěte, zda je název složky engine velkými nebo malými písmeny.
 * 1) Váš webový server běží na jedné z výše uvedených platforem.
 * 2) Funkce   PHP není omezena.
 * 3) Váš webový server je nakonfigurován tak, aby umožňoval spouštění binárních souborů ve stromu MediaWiki.
 * Možná bude nutné nastavit oprávnění ke spouštění; například v Linuxu použijte:
 * Pokud na svém serveru používáte SELinux v režimu "Enforcing", možná budete muset nastavit správný kontext pro binární soubory. Příklad pro RHEL/CentOS 7:



Další binární soubory
Další binární distribuce Lua, které mohou být potřeba pro váš webový server, pokud jeho operační systém není ve výše uvedeném seznamu, lze získat od http://luabinaries.sourceforge.net/ nebo z vaší distribuce Linuxu.

Podporovány jsou pouze binární soubory pro Lua 5.1.x.

Jakmile na svůj webový server nainstalujete příslušný binární soubor, nakonfigurujte umístění souboru pomocí:

Note that you should not add the above line unless you've confirmed that Scribunto's built-in binaries don't work for you.

LuaJIT, although theoretically compatible, is not supported.

The support was removed due to Spectre and bitrot concerns (T184156).

Integrating extensions
For a more pleasant user interface, with syntax highlighting and a code editor with autoindent, install the following extensions:

Then in your  after all the extension registrations, add:

LuaSandbox
We have developed a PHP extension written in C called LuaSandbox. It can be used as an alternative to the standalone binary, and will provide improved performance. See for details and installation instructions.

If you initially installed the extension to use the Lua standalone binary, be sure to update  with the following configuration setting:

Configuration
The following configuration variables are available:
 * $wgScribuntoDefaultEngine
 * Select the engine. Valid values are the keys in, which by default are  or.


 * $wgScribuntoUseGeSHi
 * When is installed, set this true to use it when displaying Module pages. (MediaWiki 1.30 or earlier.)


 * $wgScribuntoUseCodeEditor
 * When is installed, set this   to use it when editing Module pages. (MediaWiki 1.30 or earlier.)


 * $wgScribuntoEngineConf
 * An associative array for engine configuration. Keys are the valid values for, and values are associative arrays of configuration data. Each configuration array must contain a  key naming the   subclass to use.

LuaStandalone
The following keys are used in for. Generally you'd set these as something like


 * luaPath
 * Specify the path to a Lua interpreter.


 * errorFile
 * Specify the path to a file, writable by the web server user, where the error and debugging output from the standalone interpreter will be logged.
 * Error output produced by the standalone interpreter are not logged by default. Configure logging with:


 * memoryLimit
 * Specify the memory limit in bytes for the standalone interpreter on Linux (enforced using ulimit).


 * cpuLimit
 * Specify the CPU time limit in seconds for the standalone interpreter on Linux (enforced using ulimit).


 * allowEnvFuncs
 * Set true to allow use of setfenv and getfenv in modules.

LuaSandbox
The following keys are used in for. Generally you'd set these as something like


 * memoryLimit
 * Specify the memory limit in bytes.


 * cpuLimit
 * Specify the CPU time limit in seconds.


 * profilerPeriod
 * Specify the time between polls in sections for the Lua profiler.


 * allowEnvFuncs
 * Set true to allow use of setfenv and getfenv in modules.

Usage
Scripts go in a new namespace called Module. Each module has a collection of functions, which can be called using wikitext syntax such as:

Learning Lua
Lua is a simple programming language intended to be accessible to beginners. For a quick crash-course on Lua, try Learn Lua in 15 Minutes.

The best comprehensive introduction to Lua is the book Programming in Lua. The first edition (for Lua 5.0) is available online and is mostly relevant to Lua 5.1, the version used by Scribunto:


 * Programming in Lua (scroll down past the book ads to find the text)

The reference manual is also useful:

Lua environment
In Lua, the set of all global variables and functions is called an environment.

Each  call runs in a separate environment. Variables defined in one  will not be available from another. This restriction was necessary to maintain flexibility in the wikitext parser implementation.

Debug console



 *  See also: 

When editing a Lua module a so-called "debug console" can be found underneath the edit form. In this debug console Lua code can be executed without having to save or even create the Lua module in question.

Troubleshooting


Note that red messages are clickable and will provide more detailed information.

When using the LuaStandalone engine (this is the default), errors along the lines of "" may be generated if the standalone Lua interpreter cannot be executed or runs into various runtime errors. To obtain more information, assign a file path to. The interpreter's error output will be logged to the specified file, which should prove more helpful in tracking down the issue. The information in the debug log includes debugging information, which is why there is so much of it. You should be able to ignore any line beginning with "TX" or "RX".

If you're setting up Scribunto and are using IIS/Windows, this appears to be solved by commenting out a particular line.

When using the LuaStandalone engine (this is the default), status 2 suggests memory allocation errors, probably caused by settings that allocate inadequate memory space for PHP or Lua, or both. Assigning a file path to  and examining that output can be valuable in diagnosing memory allocation errors.

Increase PHP allocation in your PHP configuration; add the line. This allocation of 200MB is often sufficient (as of MediaWiki 1.24) but can be increased as required. Set Scribunto's memory allocation in  as a line: Finally, depending on the server configuration, some installations may be helped by adding another  line

Note that all 3 memory limits are given in different units.

Lua error: Internal error: 2. on ARM architecture
If you're using an ARM architecture processor like on a RaspberryPi you'll face the error  due to wrong delivered binary format of the Lua interpreter.

Check your Lua interpreter in: /path/to/webdir/Scribunto/includes/Engines/LuaStandalone/binaries/lua5_1_5_linux_32_generic

Check the interpreter by using: file lua The result should look like : lua: ELF 32-bit LSB executable, ARM, EABI5 version 1 (SYSV), dynamically linked, interpreter /lib/ld-linux-armhf.so.3, for GNU/Linux 3.2.0 The installed default Lua interpreter shows: lua: ELF 32-bit LSB pie executable, Intel 80386, version 1 (SYSV), dynamically linked, interpreter /lib/ld-linux.so.2, for GNU/Linux 2.6.9, look at the "Intel 80386" part what definitely is not correct.

Check in  what version of Lua is installed on your system. If you have lua5.1 installed, you can either copy the interpreter to your  directory or set in your LocalSettings.php:

At present don't set  to /usr/bin/lua5.3, it'll lead to the "Internal error 1".

When using the LuaStandalone engine (this is the default), status 24 suggests CPU time limit errors, although those should be generating a "The time allocated for running scripts has expired" message instead. It would be useful to file a task in and participate in determining why the XCPU signal isn't being caught.

When using the LuaStandalone engine (this is the default), errors along the lines of "" may be generated if the standalone Lua interpreter cannot be executed. This generally arises from either of two causes:

Set permissions as described under #Installation. This often occurs with shared hosted servers. Remedies include adjusting  to point to a Lua 5.1 binary installed in an executable location, or adjusting or convincing the shared host to adjust the setting preventing execution.
 * The lua executable file's permissions do not include Execute.
 * The server does not allow execution of files from the place where the executable is installed, e.g. the filesystem is mounted with the  flag.

Error condition such as: Fatal exception of type MWException
Check the MediaWiki, PHP, or webserver logs for more details on the exception, or temporarily set to.

version 'GLIBC_2.11' not found
If the above gives you errors such as "version 'GLIBC_2.11' not found", it means the version of the standard C library on your system is too old for the binaries provided with Scribunto. You should upgrade your C library, or use a version of Lua 5.1 compiled for the C library you do have installed. To upgrade your C library, your best option is usually to follow your distribution's instructions for upgrading packages (or for upgrading to a new release of the distribution, if applicable).

If you copy the lua binaries from Scribunto master (or from 77905), that should suffice, if you can't or don't want to upgrade your C library. The distributed binaries were recently recompiled against an older version of glibc, so the minimum is now 2.3 rather than 2.11.

Lua errors in Scribunto files
Errors here include:
 *  attempt to index field 'text' (a nil value) 
 *  Lua error in mw.html.lua at line 253: Invalid class given: 

If you are getting errors such these when attempting to use modules imported from WMF wikis, most likely your version of Scribunto is out of date.

Upgrade if possible; for advanced users, you might also try to identify the needed newer commits and cherry-pick them into your local installation.

preg_replace_callback: Compilation failed: unknown property name after \P or \p at offset 7

 * this usually indicates an incompatible version of PCRE; you'll need to update to >= 8.10
 * @todo: link to instructions on how to upgrade

Lua error
If you copy templates from Wikipedia and then get big red "Lua error: x" messages where the Scribunto invocation (e.g. the template that uses ) should be, that probably means that you didn't import everything you needed. Make sure that you tick the "Include templates" box at w:Special:Export when you export.

When importing pages from another wiki, it is also possible for templates or modules in the imported data to overwrite existing templates or modules with the same title, which may break existing pages, templates, and modules that depend on the overwritten versions.

Blank screen
Make sure your extension version is applicable to your MediaWiki version.

Design documents

 * Linux.conf.au 2014 - Scribunto presentation.webm's presentation at linux.conf.au 2014 discussing the motivations, implementation challenges and results of deploying Scribunto and Lua. ]]

Other pages

 * - Wikimedia activity page describing deployment plan to Wikimedia sites.
 * - The reference about the Lua language, as well as its standard libraries and common Scribunto modules supported on Wikimedia sites.
 * - A list of known changes in Lua 5.2 that may cause code written in 5.1 to function unexpectedly.
 * - Code for example extensions extending the Scribunto library.
 * - A list of known changes in Lua 5.2 that may cause code written in 5.1 to function unexpectedly.
 * - Code for example extensions extending the Scribunto library.
 * - Code for example extensions extending the Scribunto library.