Module:Adjacent stations/doc

This is a documentation subpage for Module:Adjacent stations.
It may contain usage information, categories and other content that is not part of the original module page.

This Lua module is used on approximately 77,000 pages and changes may be widely noticed. Test changes in the module's /sandbox or /testcases subpages, or in your own module sandbox. Consider discussing changes on the talk page before implementing them.

This module depends on the following other modules:

This module implements {{Adjacent stations}}, {{Rail icon}}, {{Rail color box}}, {{Line link}}, {{Station link}} and {{Rail color}}. Please see those templates' pages for documentation on how to use those templates. (Instructions for the convert function of this module are in the {{Adjacent stations}} documentation.)

The aforementioned templates rely on data stored in subpages for this module (list). For example, {{Rail icon|MTR}} generates using Module:Adjacent stations/MTR.

It is possible to create and edit data by following existing examples, but having some knowledge of Lua helps prevent mistakes. If you have programmed or used Lua before, you may like to skip the next subsection.

Terms

Lua has data types. The ones relevant here are boolean, string, number, and table.
- A boolean is either true or false.
- A string is text, stored as a list of characters. While Lua has several ways of indicating strings within code, in the Lua examples here, strings are indicated by enclosing text in double quotes (e.g. "This is a string").
- A number is a numerical value, like 0.5 or 42.
- A table is a structure that can contain other objects, including other tables.
  - An empty table looks like {} in the code.
  - Tables have keys and values, which are typically of the structure ["key"] = value; each key–value pair is separated by a comma. All keys used here are strings or numbers.
  - {"text", "more text"} is equivalent to {[1] = "text", [2] = "more text"}.
A variable can be defined using local variable_name = "value".
Whitespace is any tab, line break or other space. Whitespace doesn't matter in Lua, but all examples here except for those inline with text are neatly indented for readability, with separate table keys on separate lines.
A return statement (e.g. return variable_name) causes a function to exit and reports the value of variable_name. The "function" here is the code in the main module calling the subpage, and the variable_name should be the data table.

Basic structure

Two modules are demonstrated below:

Blank

local p = {
	["system title"] = "",
	["system icon"] = "",
	["station format"] = {
		"",
		[""] = "",
	},
	["lines"] = {
		[""] = {
			["title"] = "",
			["color"] = "",
			["left terminus"] = "",
			["right terminus"] = "",
		},
	},
}

return p

Example

local x = "%1 light rail station"

local p = {
	["system title"] = "[[Kaohsiung Metro]]",
	["system icon"] = "[[File:Kaohsiung Mass Rapid Transit Logo(Logo Only).svg|18px|link=Kaohsiung Rapid Transit]]",
	["rail box format"] = "title",
	["station format"] = {
		"%1 metro station",
		["Central Park"] = "Central Park metro station (Taiwan)",
		["Ciaotou"] = "Ciaotou station",
		["Gangshan"] ="Gangshan station",
		["Kaohsiung Main Station"] = "%1",
		["Zuoying"] = "%1 HSR station",
		["Hamasen"] = "%1 station",
		
		-- Circular light rail
		["Lizihnei"] = x,
		["Kaisyuan Rueitian"] = x,
		["Cianjhen Star"] = x,
		["Kaisyuan Jhonghua"] = x,
		["Dream Mall"] = x,
		["Commerce and Trade Park"] = x,
		["Software Technology Park"] = x,
		["Kaohsiung Exhibition Center"] = x,
		["Cruise Terminal"] = x,
		["Glory Pier"] = x,
		["Love Pier"] = x,
		["Dayi Pier-2"] = x,
		["Penglai Pier-2"] = x
	},
	["lines"] = {
		["_default"] = {
			["title"] = "[[%1 line (Kaohsiung Metro)|%1 line]]"
		},
		["Red"] = {
			["color"] = "e20b65",
			["icon"] = "[[File:Kaohsiung MRT Red Line.svg|20px|link=Red line (Kaohsiung Metro)]]",
			["left terminus"] = "Gangshan",
			["right terminus"] = "Siaogang"
		},
		["Orange"] = {
			["color"] = "faa73f",
			["icon"] = "[[File:Kaohsiung Metro Orange Line.svg|20px|link=Orange line (Kaohsiung Metro)]]",
			["left terminus"] = "Hamasen",
			["right terminus"] = "Daliao"
		},
		["Circular"] = {
			["title"] = "[[Circular light rail]]",
			["short name"] = "Circular line",
			["color"] = "7cbd52",
			["icon"] = "[[File:Kaohsiung LRT Circular Line.svg|20px|link=Circular light rail]]",
			["circular"] = 1,
			["left terminus"] = "outer loop / anticlockwise",
			["right terminus"] = "inner loop / clockwise"
		},
		-- Future lines
		["Yellow"] = {
			["color"] = "ffc100",
			["icon"] = "[[File:Kaohsiung Rapid Transit Yellow Line.svg|20px|link=Yellow line (Kaohsiung Metro)]]",
			["left terminus"] = {"Cruise Terminal", "Cianjhen Senior High School"},
			["right terminus"] = "Dipu"
		},
		-- Proposed
		["Yanchao"] = {
			["title"] = "[[Kaohsiung Metro#All projects|Yanchao line]]",
			["color"] = "c100ff"
		},
		["Youchang"] = {
			["title"] = "[[Kaohsiung Metro#All projects|Youchang line]]",
			["color"] = "008583"
		},
		["Fongshan"] = {
			["title"] = "[[Kaohsiung Metro#All projects|Fongshan line]]",
			["color"] = "007fff"
		},
		["Green"] = {
			["title"] = "[[Kaohsiung Metro#All projects|Green line]]",
			["color"] = "50cb00"
		},
		["Foguangshan"] = {
			["title"] = "[[Kaohsiung Metro#All projects|Foguangshan line]]",
			["color"] = "aa34c0"
		},
		["Cijin"] = {
		["title"] = "[[Kaohsiung Metro#All projects|Cijin line]]",
		["color"] = "e10a65"
		},
	},
	["aliases"] = {
		["circular"] = "Circular",
		["c"] = "Circular",
		["orange"] = "Orange",
		["o"] = "Orange",
		["red"] = "Red",
		["r"] = "Red",
		["yellow"] = "Yellow",
		["y"] = "Yellow"
	}
}

return p

The example module is Module:Adjacent stations/Kaohsiung Rapid Transit.

The two required table entries are "station format" and "lines". The former is a table with data to form links to station articles, and the latter is a table containing a table for each line.
"system title" is the text in the middle cell of the table header row.
"station format" defines the default name format for station articles and exceptions. The first variable ("%1 metro station") is the default. Exceptions are listed as key–value pairs (e.g. "Zuoying"–"Zuoying HSR station"), where the key is the input name. The module displays the input name and links to the article with the formatted name, replacing "%1" with the input. Alternatively, the full wikilink and be entered. This can be used to have the display be different from the input.
"lines" is where the lines are listed. The names here are used internally and not displayed, so choose a concise one.
"line title" is the text displayed in the middle of each row indicating the line; "left terminus" is the default station name for the left side terminus, and "right terminus" is the default station name for the right side terminus.
Each "color" entry is the colour of the line.

Below is Module:Adjacent stations/Taiwan High Speed Rail:

local x = "%1 station"

local p = {
	["system title"] = "[[Taiwan High Speed Rail]]",
	["system icon"] = "[[File:Taiwan High Speed Rail Logo(Log Only).svg|18px|link=Taiwan High Speed Rail|alt=Taiwan High Speed Rail]]",
	["system color"] =  "c35617",
	["name format"] = "color: #FFFFFF; background-color: #C35617;",
	["station format"] = {
		"%1 HSR station",
		["Taipei"] = "Taipei Main Station",
		["Nangang"] = x,
		["Banqiao"] = x
	},
	["lines"] = {
		["_default"] = {
			["title"] = "[[Taiwan High Speed Rail|THSR]]",
			["color"] = "c35617",
			["left terminus"] = "Nangang",
			["right terminus"] = "Zuoying"
		}
	}
}

return p

x (defined in the first line) is a string used for formatting the station name. The variable x is used inside the "station format" table for the three articles where the title ends in "station" instead of "HSR station". This practice is optional but helpful when many articles fit a second pattern.
The module recognises a virtual line named ["_default"]. The title and colour of this line is used for all lines unless overridden. Parameters are used in the absence of a specified line= in transclusion.

Hierarchy and list of parameters

The first layer of the table is data for the entire system, as well as output options.
Under the system table is the list of lines.
The third layer is data for a given line.
Each line can have 'types'. This can be either types of services or branches of the line.
The fifth layer is data for a given type.

If not specified, all keys and values are strings.

Main layer (1)


Parameter	Type	Used in {{Adjacent stations}}	Description
`["lang"]`	String	Yes	Values are `"en-US"` and `"en-GB"`. If not set, `"en-GB"` is assumed.
`["system title"]`	String	Yes	Text in the middle cell of the header.
`["system icon"]`	String	Yes	Image used in the middle cell of the {{Adjacent stations}} header and by {{Rail icon}}.
`["system icon format"]`	String	No	Icon type, used by {{Rail icon}}. If specified and not `"image"`, the value is passed to the function that implements {{Rail color box}}.
`["system color"]`	String	No	RGB hex triplet (three or six characters, like `"BE2D2C"` or `"039"`). Can be called by using only one parameter in {{Rail color}}.
`["header stop noun"]`	String	Yes	The noun after 'preceding' and 'following' in the left and right header cells. Default value is `"station"`.
`["name format"]`	String	No	CSS for the header of {{Infobox station}} and anything else using the `style` function with `\|1=header`. Values can be strings or nested tables, with the first level being for the line (whatever's in `\|style2=` of {{Infobox station}}). The second level is currently unused. The first entry in a nested table with no key (i.e. with key `1`) is the default.
`["header background color"]`	String	No	RGB hex triplet for {{Infobox station}} subheaders and anything else using the `style` function with `\|1=subheader`. By default, it is a light gray. Values can be strings or nested tables, like those for `"name format"`.
`["header text color"]`	String	No	RGB hex triplet for {{Infobox station}} subheaders and anything else using the `style` function with `\|1=subheader`. By default, it is calculated based on the header background color. Values can be strings or nested tables, like those for `["name format"]`.
`["station format"]`	Table or string	Yes	Table containing station format strings. The first entry without a specified key (i.e. with the key being the number `1`) is the default, and all other entries must have keys corresponding to the input. Format strings without wikilink brackets are converted to links, with the input (usually the station name) used as the displayed text. Tables can be nested within this table to indicate options based on the line and line type passed to this template. `%1`, `%2` and `%3` can be used in all strings regardless of the level of nesting to be replaced respectively by the station input, the line input (after alias replacement) and the type input (after alias replacement).
`["lines"]`	Table	Yes	Data table containing line tables.
`["aliases"]`	Table	Yes	Table containing aliases (as table keys) for lines (as values). All keys are lowercase, as the input is treated as case-insensitive by being lower-cased.

Station format table (2)


Parameter	Type	Used in {{Adjacent stations}}	Description
`[1]`	String	Yes	Default format.
`["non-default station name"]`	String or table	Yes	Format for a non-default station, or line-specific format table.

Line-specific format table (3)


Parameter	Type	Used in {{Adjacent stations}}	Description
`[1]`	String	Yes	Default format.
`["line name"]`	String or table	Yes	Format for a non-default station, or type-specific format table.

Type-specific format table (4)


Parameter	Type	Used in {{Adjacent stations}}	Description
`[1]`	String	Yes	Default format.
`["type name"]`	String	Yes	Format for a non-default station.

Line table (3)

A virtual line named ["_default"] can be added to set default values for all lines. Currently, this is available for three parameters.

Parameter	Type	Used in {{Adjacent stations}}	Description
`["title"]`	String	Yes	The text displayed in the middle cell, typically a link to the line's article. If not specified, then the data in `["_default"]` is used (`%1` in the default value is replaced by the input after alias replacement).
`["short name"]`	String	No	Abbreviated line name used by {{Rail color box}}.
`["icon"]`	String	No	Image used by {{Rail icon}}. If not specified, then the data in `["_default"]` is used (`%1` in the default value is replaced by the input after alias replacement).
`["icon format"]`	String	No	Icon type used by {{Rail icon}}. If specified and not `"image"`, the value is passed to the function that implements {{Rail color box}}.
`["color"]`	String	Yes	RGB hex triplet. Lines fall back to the `["_default"]` colour (if any) or the system's colour if they themselves do not have one; types fall back to the line's colour (if any), to the `["_default"]` colour (if any) or to the system's colour. This colour is used in the second and fourth columns of {{Adjacent stations}}, and by {{Rail color box}} and {{Rail icon}} as the emphasised colour. By default, if a type and its line both have a colour, then the line's colour will be treated as the background colour (see next section) for the line name in the middle cell. This can be turned off by setting the type's background colour to `""` or `"transparent"`.
`["background color"]`	String	Yes	RGB hex triplet (three or six characters). This colour is optional and is only displayed behind the line name in the middle cell. The module adds transparency so that all text displayed over the background is legible.
`["border color"]`	String	No	RGB hex triplet used by {{Rail color box}}.
`["text color"]`	String	No	RGB hex triplet used by {{Rail color box}}.
`["left terminus"]`	String	Yes	The station which is usually the left terminus of the line. If there are multiple stations by default, the value should be a table containing numbered values (e.g. `["left terminus"] = {"Chesham", "Amersham"}`). The key `["via"]` in that table can be used to append 'via' and the value's station link.
`["right terminus"]`	String	Yes	The station which is usually the right terminus of the line; behaves like `["left terminus"]`.
`["note-mid"]`	String	Yes	Default small text below line and type names. Overridden by `\|note-mid=` in transclusion.
`["circular"]`	Boolean	Yes	If the value is `true` then the termini will display without 'toward'/'towards'. May be overridden by type.
`["oneway-left"]`	Boolean	Yes	If the value is `true` then 'One-way operation' will display instead of the left terminus.
`["oneway-right"]`	Boolean	Yes	Right counterpart of oneway-left.
`["types"]`	Table	Yes	Table containing the line type tables.

Type table (5)

Parameter	Type	Used in {{Adjacent stations}}	Description
`["title"]`	String	Yes	The name of the line type. In {{Adjacent stations}}, this is displayed as normal-sized text below the line name in the middle cell; in {{Rail color box}}, for some options this is displayed after the line name, separated from it by a spaced en dash (this is also used for the nonstop text). To avoid displaying a type name, set this to `""`.
`["short name"]`	String	No	Abbreviated line name used by {{Rail color box}}.
`["icon"]`	String	No	Image used by {{Rail icon}}.
`["icon format"]`	String	No	Icon type used by {{Rail icon}}. If specified and not `"image"`, the value is passed to the function that implements {{Rail color box}}.
`["color"]`	String	Yes	RGB hex triplet. Lines fall back to the `["_default"]` colour (if any) or the system's colour if they themselves do not have one; types fall back to the line's colour (if any), to the `["_default"]` colour (if any) or to the system's colour. This colour is used in the second and fourth columns of {{Adjacent stations}}, and by {{Rail color box}} and {{Rail icon}} as the emphasised colour. By default, if a type and its line both have a colour, then the line's colour will be treated as the background colour (see next section) for the line name in the middle cell. This can be turned off by setting the type's background colour to `""` or `"transparent"`.
`["background color"]`	String	Yes	RGB hex triplet (three or six characters). This colour is optional and is only displayed behind the line name in the middle cell. The module adds transparency so that all text displayed over the background is legible.
`["border color"]`	String	No	RGB hex triplet used by {{Rail color box}}.
`["text color"]`	String	No	RGB hex triplet used by {{Rail color box}}.
`["left terminus"]`	String	Yes	The station which is usually the left terminus of the line. Overrides line terminus. If there are multiple stations by default, the value should be a table containing numbered values (e.g. `["left terminus"] = {"Chesham", "Amersham"}`). The key `["via"]` in that table can be used to append 'via' and the value's station link.
`["right terminus"]`	String	Yes	The station which is usually the right terminus of the line; behaves like `["left terminus"]`.
`["note-mid"]`	String	Yes	Default small text below line and type names. Overridden by `\|note-mid=` in transclusion.
`["circular"]`	Boolean	Yes	If the value is `true` then the termini will display without 'toward'/'towards'.

For editors

Disambiguating stations

Station links are generated using the station format part of the data module. Each data module defines a default case and then exceptions, if necessary. Station format is an array, similar to a switch with cases. Take Module:Adjacent stations/Incheon Subway, shown below:

local incheon = "%1 station (Incheon)"
local n = "font-size: 160%; font-family:sans-serif; font-weight: bolder; color: #FFFFFF; padding: 0.4em 4px; background-color: #"
local colors = {
	["1"] = "8cadcb",
	["2"] = "f06a00",
	["3"] = "777777",
}

local p = {
	["system title"] = "[[Incheon Subway]]",
	["system icon"] = "",
	["name format"] = {
	    ["1"] = n .. colors["1"],
	    ["2"] = n .. colors["2"],
	    ["3"] = n .. colors["3"],
	},
    ["header background color"] = colors,
    ["header text color"] = "ffffff",
	["station format"] = {
		"%1 station",
		["Arts Center"] = incheon,
		["Central Park"] = incheon,
		["Gyeongin National University of Education"] = "[[Gyeongin National University of Education station|Gyeongin Nat'l Univ. of Education]]",
		["Mansu"] = incheon,
		["Seongnam"] = incheon,
	},
	["lines"] = {
		["1"] = {
			["title"] = "[[Incheon Subway Line 1|Incheon Line 1]]",
			["color"] = colors["1"],
			["text color"] = "FFFFFF",
			["icon"] = "[[File:Incheon Metro Line 1.svg|16px|link=Incheon Subway Line 1]]",
			["left terminus"] = "Gyeyang",
			["right terminus"] = "Songdo Moonlight Festival Park",
		},
		["2"] = {
			["title"] = "[[Incheon Subway Line 2|Incheon Line 2]]",
			["color"] = colors["2"],
			["text color"] = "FFFFFF",
			["icon"] = "[[File:Incheon Metro Line 2.svg|16px|link=Incheon Subway Line 2]]",
			["left terminus"] = "Geomdan Oryu",
			["right terminus"] = "Unyeon",
		},
		["3"] = {
			["title"] = "[[Incheon Subway Line 3|Incheon Line 3]]",
			["color"] = colors["3"],
			["text color"] = "FFFFFF",
		}
	}
}

return p

The default case is "%1 station", listed first. The "%1" expands to whatever the passed name of the station is. "Bakchon" becomes Bakchon station. There are several exceptions. The two usual reasons for exceptions are disambiguation or presenting a name in a non-standard way. In this case, the Incheon Subway serves three stations whose names are disambiguated: Arts Center station (Incheon), Central Park station (Incheon), and Mansu station (Incheon). This is handled by specifying a key for each station and supplying a different format. Since all three are disambiguated the same way, you can define a local variable at the top of the module:

local incheon = "%1 station (Incheon)"

This can then be used with the exceptions:

["Arts Center"] = incheon,

Were it written out, it would look like this:

["Arts Center"] = "%1 station (Incheon)"

For developers

Suggestions are welcomed on the talk page.

To-do list

Convert more systems from {{S-line}}, {{rail line}}, {{J-rserv}} and {{J-route}}
Make an example module which contains all of the module's features, to avoid excessive examples in the documentation (maybe based on {{Rdt demo}})
Allow direct replacement of {{Rail line}}?
Before translation: figure out how to handle grammatical gender and inflection in various languages with the i18n table (e.g. these phrases)
Allow inline sources to be added
Figure out Wikidata integration (require sources on Wikidata end) :
should be doable with P197, P5051, P1192 and P81. Bouzinac (talk) 09:17, 3 December 2021 (UTC)
Add a short list of changes from {{S-line}}, for the convenience of the many editors who have used it in the last 11 years
- changes in function (new structure, data inside module, circular and branch functionality changed, replacement of manual cell merging…)
- parameter name changes (-left and -right, mostly – search {{S-line}} for {{{, maybe with the TemplateData generator, to make a list)