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+ | {{Infobox Lua templating}} |
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− | [[File:Lua-logo-nolabel.png|thumb|220x220px]] |
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− | This page covers some of the absolute basics for developing a simple [[ |
+ | This page covers some of the absolute basics for developing a simple [[Help:Lua|Lua]] template. |
== Basics == |
== Basics == |
||
+ | {{Main|Lua templating/Basics}} |
||
− | Before starting with lua templates, it is important to read up and get to know how to use regular [[Help:Templates|wikitext templates]], and preferably read/learn about lua in sites such as [[Wikibooks:Lua Programming|Wikibooks]] as well as reviewing [[Lua templating/Reference manual|Lua Reference manual]]. |
+ | Before starting with lua templates, it is important to read up and get to know how to use regular [[Help:Templates|wikitext templates]], and preferably read/learn about lua in sites such as [[Wikibooks:Lua Programming|Wikibooks]] as well as reviewing the [[Lua templating/Reference manual|Lua Reference manual]]. |
=== Workspace === |
=== Workspace === |
||
− | Lua templates are |
+ | Lua templates are stored in the [[Help:namespaces|Module namespace]], and all work must always be saved there. For example, a module named helloworld would be stored in Module:Helloworld. |
=== Creating a module === |
=== Creating a module === |
||
− | A module must always contain a [[Wikibooks:Lua Programming/Tables|table]] and a line containing a "return " for that table unless it is a meta-module(see below). |
+ | A module must always contain a [[Wikibooks:Lua Programming/Tables|table]] and a line containing a "return " for that table unless it is a meta-module (see below). |
− | < |
+ | <syntaxhighlight lang="lua"> |
--Table |
--Table |
||
local p = {} |
local p = {} |
||
-- code goes here |
-- code goes here |
||
return p |
return p |
||
− | </ |
+ | </syntaxhighlight>For a module to be invoked (or used in a page), it needs to have a function. However, this function must be part of the main table (e.g. invocable): |
− | < |
+ | <syntaxhighlight lang="lua"> |
--Table |
--Table |
||
local invocable = {} |
local invocable = {} |
||
Line 32: | Line 33: | ||
end |
end |
||
return invocable |
return invocable |
||
+ | </syntaxhighlight> |
||
− | </source> |
||
=== Execution time === |
=== Execution time === |
||
− | Lua |
+ | Lua modules used can only run for a maximum of 10 seconds. This means that modules within a page cannot take longer than 10 seconds to execute, or there will be an error. |
− | == |
+ | == Copying modules to another wiki == |
+ | Modules hosted here can be used in another wiki, but this may require steps: |
||
+ | # Copy the module to your wiki, e.g. [[Module:Links]] |
||
+ | # Copy all modules it depends on to your wiki. This is a bit complicated because Fandom uses an older scribunto version. But these steps should help: |
||
+ | ## Open the module page and find sections that contain text like "require("text"), e.g. in module links text =="Dev:Arguments". |
||
+ | ## Search for the module in dev.wikia or any other wiki, e.g. Module:Arguments |
||
+ | ## Copy this module:arguments to your wiki |
||
+ | ## Replace all mentions of require("Dev:") with require("module:"), e.g. require("Module:Arguments") |
||
+ | # Redo step two, for every time a require("") is found in copied module. |
||
+ | |||
+ | ==Using input (parameters)== |
||
Input (or [[Help:Template parameters|Template parameters]]) can be provided to a module during the invoke. |
Input (or [[Help:Template parameters|Template parameters]]) can be provided to a module during the invoke. |
||
Line 43: | Line 54: | ||
<pre>{{#invoke:modulename|functioname|input1|input2|input3|...}}</pre> |
<pre>{{#invoke:modulename|functioname|input1|input2|input3|...}}</pre> |
||
− | Once the above code is executed a table (called frame) is created containing all those inputs, and it is passed to a function, and stored in a |
+ | Once the above code is executed a table (called frame) is created containing all those inputs, and it is passed to a function, and stored in a sub-table called args (e.g. frame.args). For example, using the invoke below will make use of the module: |
<pre>{{#invoke:invocable|greet|john}}</pre> |
<pre>{{#invoke:invocable|greet|john}}</pre> |
||
<pre>{{#invoke:invocable|greet|name=john}}</pre> |
<pre>{{#invoke:invocable|greet|name=john}}</pre> |
||
− | < |
+ | <syntaxhighlight lang="lua"> |
--Module:Invocable |
--Module:Invocable |
||
--Table |
--Table |
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Line 58: | Line 69: | ||
return invocable |
return invocable |
||
+ | </syntaxhighlight> |
||
− | </source> |
||
<pre>Output : Live long and prosper john</pre> |
<pre>Output : Live long and prosper john</pre> |
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Line 65: | Line 76: | ||
=== Accessing template input === |
=== Accessing template input === |
||
− | The invoke above cannot be used through a template because the values from a page |
+ | The invoke above cannot be used through a template because the values from a page and a sub-page are kept separate. Those arguments can only be accessed from a template by first retrieving the parent frame or table containing the arguments (i.e. frame:getParent()), and then using the sub-table (frame:getParent().args): |
'''Template:Greet:''' |
'''Template:Greet:''' |
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Line 71: | Line 82: | ||
'''Module:Invocable:''' |
'''Module:Invocable:''' |
||
− | < |
+ | <syntaxhighlight lang="lua"> |
--Table |
--Table |
||
local invocable = {} |
local invocable = {} |
||
function invocable.greet(frame) |
function invocable.greet(frame) |
||
− | local parent = frame |
+ | local parent = frame:getParent() |
local name = parent.args[1] |
local name = parent.args[1] |
||
local name2 = parent.args[2] or "" |
local name2 = parent.args[2] or "" |
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Line 84: | Line 95: | ||
return invocable |
return invocable |
||
+ | </syntaxhighlight> |
||
− | </source> |
||
'''Usage:''' |
'''Usage:''' |
||
<pre>{{greet|Jack}} |
<pre>{{greet|Jack}} |
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Line 101: | Line 112: | ||
|1 |
|1 |
||
| {{{1}}} |
| {{{1}}} |
||
− | |frame |
+ | |frame:getParent().args[1] |
+ | |john |
||
− | |Live long and prosper john |
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|- |
|- |
||
|<nowiki>{{greet|name=Spock}}</nowiki> |
|<nowiki>{{greet|name=Spock}}</nowiki> |
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|name |
|name |
||
|{{{name}}} |
|{{{name}}} |
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− | |frame |
+ | |frame:getParent().args["name"] |
− | | |
+ | |Spock |
|- |
|- |
||
|<nowiki>{{#invoke:invocable|greet|john}}</nowiki> |
|<nowiki>{{#invoke:invocable|greet|john}}</nowiki> |
||
Line 125: | Line 136: | ||
|1,2 |
|1,2 |
||
| |
| |
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− | |frame.args[1], |
+ | |frame.args[1], frame.args[2] |
+ | |Jack , Jill |
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− | frame.args[2] |
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− | |Live long and prosper : Jack Jill |
||
|} |
|} |
||
== Script errors == |
== Script errors == |
||
− | Whenever a module doesn't work properly it triggers a script error in a page. A good explanation of script errors is maintained by Wikipedia<ref>Wikipedia: |
+ | Whenever a module doesn't work properly it triggers a script error in a page. A good explanation of script errors is maintained by Wikipedia<ref>[[Wikipedia:Wikipedia:Lua error messages]]</ref>. |
− | |||
⚫ | |||
⚫ | |||
== Advanced == |
== Advanced == |
||
− | + | An advantage of lua is that it enables one to use external modules and tables that have been created by others. This reduces the need to reinvent the wheel, and more time can actually be spent creating new solutions. |
|
=== Using other modules === |
=== Using other modules === |
||
To use libraries or modules one needs to import that library. This is done using the [[Lua templating/Reference manual/Standard libraries|require]] method: |
To use libraries or modules one needs to import that library. This is done using the [[Lua templating/Reference manual/Standard libraries|require]] method: |
||
− | < |
+ | <syntaxhighlight lang="lua"> |
--Module:Libraries |
--Module:Libraries |
||
local library = {} |
local library = {} |
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Line 153: | Line 160: | ||
return library |
return library |
||
+ | </syntaxhighlight> |
||
− | </source> |
||
<pre>{{#invoke:library|greet|Zeus}} |
<pre>{{#invoke:library|greet|Zeus}} |
||
Output:Live long and prosper Zeus |
Output:Live long and prosper Zeus |
||
Line 159: | Line 166: | ||
− | '''Note:''' The syntax is [[Wikipedia:case sensitivity|case sensitive]] so "Dev" |
+ | '''Note:''' The syntax is [[Wikipedia:case sensitivity|case sensitive]] so "Dev" != "dev". |
====Meta-Modules==== |
====Meta-Modules==== |
||
These are modules that are not meant to be used in a page (e.g. <nowiki>{{#invoke</nowiki>), and don't necessarily have any functions that can be used in a page. |
These are modules that are not meant to be used in a page (e.g. <nowiki>{{#invoke</nowiki>), and don't necessarily have any functions that can be used in a page. |
||
Line 166: | Line 173: | ||
A external table can be retrieved in the same way as an external module, except that there is an extra method ([[Lua templating/Reference manual/Scribunto libraries|mw.loadData]]) that loads it once per page, making it more efficient. |
A external table can be retrieved in the same way as an external module, except that there is an extra method ([[Lua templating/Reference manual/Scribunto libraries|mw.loadData]]) that loads it once per page, making it more efficient. |
||
− | < |
+ | <syntaxhighlight lang="lua"> |
--Module:Tables |
--Module:Tables |
||
local tables = {'food','garden','relic'} |
local tables = {'food','garden','relic'} |
||
return tables |
return tables |
||
+ | </syntaxhighlight> |
||
− | </source> |
||
==== Usage: ==== |
==== Usage: ==== |
||
− | < |
+ | <syntaxhighlight lang="lua"> |
--Module:showobjects |
--Module:showobjects |
||
local p = {} |
local p = {} |
||
Line 187: | Line 194: | ||
return p |
return p |
||
+ | </syntaxhighlight> |
||
− | </source> |
||
<pre>{{#invoke:showobjects|show}} |
<pre>{{#invoke:showobjects|show}} |
||
Output: "food & garden" |
Output: "food & garden" |
||
Line 193: | Line 200: | ||
=== Global modules === |
=== Global modules === |
||
− | Modules stored in |
+ | Modules stored in dev.fandom.com are called global modules. They work in a similar manner to modules stored in a wiki but can be accessed by any lua module from another wiki (e.g. food.fandom.com). The difference lies only in the syntax (it uses "Dev" instead of "Module") used to obtain the modules: |
− | < |
+ | <syntaxhighlight lang="lua"> |
local global_invocable = require("Dev:Invocable") |
local global_invocable = require("Dev:Invocable") |
||
local global_Tables = mw.loadData("Dev:Tables") |
local global_Tables = mw.loadData("Dev:Tables") |
||
+ | </syntaxhighlight> |
||
− | </source> |
||
+ | |||
+ | == Tools == |
||
+ | There are a bunch of useful tools that can help create modules: |
||
+ | |||
+ | === Code-editor === |
||
+ | The code-editor (or ace-editor) - this is the default editor that can be disabled as needed. |
||
+ | |||
+ | Ace editor in particular comes with a couple of hidden features such as keyboard shortcuts and macros<ref>https://github.com/ajaxorg/ace/wiki/Default-Keyboard-Shortcuts</ref>. |
||
+ | |||
+ | ==== Keyboard shortcuts ==== |
||
+ | A brief list of some useful shortcuts is shown below: |
||
+ | {| |
||
+ | !Windows/Linux |
||
+ | !Mac |
||
+ | !Action |
||
+ | |- |
||
+ | |Alt-Shift-Down |
||
+ | |Command-Option-Down |
||
+ | |Copy lines down |
||
+ | |- |
||
+ | |Alt-Shift-Up |
||
+ | |Command-Option-Up |
||
+ | |Copy lines up |
||
+ | |- |
||
+ | |Alt-Down |
||
+ | |Option-Down |
||
+ | |Move lines down |
||
+ | |- |
||
+ | |Alt-Up |
||
+ | |Option-Up |
||
+ | |Move lines up |
||
+ | |- |
||
+ | |Alt-Delete |
||
+ | |Ctrl-K |
||
+ | |Remove to line end |
||
+ | |- |
||
+ | |Alt-Backspace |
||
+ | |Command-Backspace |
||
+ | |Remove to linestart |
||
+ | |- |
||
+ | |Ctrl-Backspace |
||
+ | |Option-Backspace, Ctrl-Option-Backspace |
||
+ | |Remove word left |
||
+ | |- |
||
+ | |Ctrl-Delete |
||
+ | |Option-Delete |
||
+ | |Remove word right |
||
+ | |- |
||
+ | |<nowiki>---</nowiki> |
||
+ | |Ctrl-O |
||
+ | |Split line |
||
+ | |} |
||
+ | {| |
||
+ | !Windows/Linux |
||
+ | !Mac |
||
+ | !Action |
||
+ | |- |
||
+ | |Ctrl-Shift-E |
||
+ | |Command-Shift-E |
||
+ | |Macros replay |
||
+ | |- |
||
+ | |Ctrl-Alt-E |
||
+ | |<nowiki>---</nowiki> |
||
+ | |Macros recording |
||
+ | |} |
||
+ | |||
+ | === Syntax highlighting and syntax checking === |
||
+ | The interactive code editor always highlights syntax errors, and sometimes gives helpful information to fix them. |
||
+ | |||
⚫ | |||
⚫ | |||
+ | This is a console or terminal that makes it easy to test out code. |
||
== See also == |
== See also == |
||
− | * [[Lua |
+ | * [[Help:Lua]] |
* [[Lua templating/Debug console]] |
* [[Lua templating/Debug console]] |
||
+ | * [[Lua templating/Glossary]] |
||
⚫ | |||
+ | * [[Lua templating/Style guide]] |
||
+ | |||
+ | == References == |
||
+ | <references /> |
||
+ | |||
⚫ |
Revision as of 22:50, 1 August 2020
This page covers some of the absolute basics for developing a simple Lua template.
Basics
- Main article: Lua templating/Basics
Before starting with lua templates, it is important to read up and get to know how to use regular wikitext templates, and preferably read/learn about lua in sites such as Wikibooks as well as reviewing the Lua Reference manual.
Workspace
Lua templates are stored in the Module namespace, and all work must always be saved there. For example, a module named helloworld would be stored in Module:Helloworld.
Creating a module
A module must always contain a table and a line containing a "return " for that table unless it is a meta-module (see below).
--Table
local p = {}
-- code goes here
return p
For a module to be invoked (or used in a page), it needs to have a function. However, this function must be part of the main table (e.g. invocable):
--Table
local invocable = {}
--can be invoked
function invocable.greet(frame)
return "Live long and prosper"
end
-- can't be invoked
function askname(frame)
return "What's your name?"
end
return invocable
Execution time
Lua modules used can only run for a maximum of 10 seconds. This means that modules within a page cannot take longer than 10 seconds to execute, or there will be an error.
Copying modules to another wiki
Modules hosted here can be used in another wiki, but this may require steps:
- Copy the module to your wiki, e.g. Module:Links
- Copy all modules it depends on to your wiki. This is a bit complicated because Fandom uses an older scribunto version. But these steps should help:
- Open the module page and find sections that contain text like "require("text"), e.g. in module links text =="Dev:Arguments".
- Search for the module in dev.wikia or any other wiki, e.g. Module:Arguments
- Copy this module:arguments to your wiki
- Replace all mentions of require("Dev:") with require("module:"), e.g. require("Module:Arguments")
- Redo step two, for every time a require("") is found in copied module.
Using input (parameters)
Input (or Template parameters) can be provided to a module during the invoke.
Syntax
{{#invoke:modulename|functioname|input1|input2|input3|...}}
Once the above code is executed a table (called frame) is created containing all those inputs, and it is passed to a function, and stored in a sub-table called args (e.g. frame.args). For example, using the invoke below will make use of the module:
{{#invoke:invocable|greet|john}}
{{#invoke:invocable|greet|name=john}}
--Module:Invocable
--Table
local invocable = {}
function invocable.greet(frame)
local name = frame.args[1] or frame.args["name"]
return "Live long and prosper " ..name
end
return invocable
Output : Live long and prosper john
Explanation : Args is a list containing all parameters, args[1] refers to the first value, e.g. john, args["name"] accesses a named parameter "name".
Accessing template input
The invoke above cannot be used through a template because the values from a page and a sub-page are kept separate. Those arguments can only be accessed from a template by first retrieving the parent frame or table containing the arguments (i.e. frame:getParent()), and then using the sub-table (frame:getParent().args):
Template:Greet:
{{#invoke:invocable|greet}}
Module:Invocable:
--Table
local invocable = {}
function invocable.greet(frame)
local parent = frame:getParent()
local name = parent.args[1]
local name2 = parent.args[2] or ""
return "Live long and prosper :" ..name ..' '..name2
end
return invocable
Usage:
{{greet|Jack}} Output:Live long and prosper : Jack {{greet|Jack|Jill}} Output:Live long and prosper : Jack Jill
Example | Parameter | Template | Module | Output |
---|---|---|---|---|
{{greet|john}} | 1 | {{{1}}} | frame:getParent().args[1] | john |
{{greet|name=Spock}} | name | {{{name}}} | frame:getParent().args["name"] | Spock |
{{#invoke:invocable|greet|john}} | 1 | frame.args[1] | john | |
{{#invoke:invocable|greet|name=Worf}} | name | frame.args["name"] | Worf | |
{{#invoke:invocable|greet|jack|jill}} | 1,2 | frame.args[1], frame.args[2] | Jack , Jill |
Script errors
Whenever a module doesn't work properly it triggers a script error in a page. A good explanation of script errors is maintained by Wikipedia[1].
Advanced
An advantage of lua is that it enables one to use external modules and tables that have been created by others. This reduces the need to reinvent the wheel, and more time can actually be spent creating new solutions.
Using other modules
To use libraries or modules one needs to import that library. This is done using the require method:
--Module:Libraries
local library = {}
function library.greet(frame)
local invocable = require("Module:Invocable")
return invocable.greet(frame)
end
return library
{{#invoke:library|greet|Zeus}} Output:Live long and prosper Zeus
Note: The syntax is case sensitive so "Dev" != "dev".
Meta-Modules
These are modules that are not meant to be used in a page (e.g. {{#invoke), and don't necessarily have any functions that can be used in a page.
Using external tables
A external table can be retrieved in the same way as an external module, except that there is an extra method (mw.loadData) that loads it once per page, making it more efficient.
--Module:Tables
local tables = {'food','garden','relic'}
return tables
Usage:
--Module:showobjects
local p = {}
function p.show(frame)
local objects = require("Module:Tables")
--using loadData
local objects2 = mw.loadData("Module:Tables")
return objects[1] ..' & ' objects2[2]
end
return p
{{#invoke:showobjects|show}} Output: "food & garden"
Global modules
Modules stored in dev.fandom.com are called global modules. They work in a similar manner to modules stored in a wiki but can be accessed by any lua module from another wiki (e.g. food.fandom.com). The difference lies only in the syntax (it uses "Dev" instead of "Module") used to obtain the modules:
local global_invocable = require("Dev:Invocable")
local global_Tables = mw.loadData("Dev:Tables")
Tools
There are a bunch of useful tools that can help create modules:
Code-editor
The code-editor (or ace-editor) - this is the default editor that can be disabled as needed.
Ace editor in particular comes with a couple of hidden features such as keyboard shortcuts and macros[2].
Keyboard shortcuts
A brief list of some useful shortcuts is shown below:
Windows/Linux | Mac | Action |
---|---|---|
Alt-Shift-Down | Command-Option-Down | Copy lines down |
Alt-Shift-Up | Command-Option-Up | Copy lines up |
Alt-Down | Option-Down | Move lines down |
Alt-Up | Option-Up | Move lines up |
Alt-Delete | Ctrl-K | Remove to line end |
Alt-Backspace | Command-Backspace | Remove to linestart |
Ctrl-Backspace | Option-Backspace, Ctrl-Option-Backspace | Remove word left |
Ctrl-Delete | Option-Delete | Remove word right |
--- | Ctrl-O | Split line |
Windows/Linux | Mac | Action |
---|---|---|
Ctrl-Shift-E | Command-Shift-E | Macros replay |
Ctrl-Alt-E | --- | Macros recording |
Syntax highlighting and syntax checking
The interactive code editor always highlights syntax errors, and sometimes gives helpful information to fix them.
Debug console
- Main article: Lua templating/Debug console
This is a console or terminal that makes it easy to test out code.
See also
- Help:Lua
- Lua templating/Debug console
- Lua templating/Glossary
- Lua templating/Style guide