-- This module provides easy processing of arguments passed to Scribunto from
-- #invoke. It is intended for use by other Lua modules, and should not be
-- called from #invoke directly.
local
libraryUtil
=
require
(
'libraryUtil'
)
local
checkType
=
libraryUtil
.
checkType
local
arguments
=
{}
-- Generate four different tidyVal functions, so that we don't have to check the
-- options every time we call it.
local
function
tidyValDefault
(
key
,
val
)
if
type
(
val
)
==
'string'
then
val
=
val
:
match
(
'^%s*(.-)%s*$'
)
if
val
==
''
then
return
nil
else
return
val
end
else
return
val
end
end
local
function
tidyValTrimOnly
(
key
,
val
)
if
type
(
val
)
==
'string'
then
return
val
:
match
(
'^%s*(.-)%s*$'
)
else
return
val
end
end
local
function
tidyValRemoveBlanksOnly
(
key
,
val
)
if
type
(
val
)
==
'string'
then
if
val
:
find
(
'%S'
)
then
return
val
else
return
nil
end
else
return
val
end
end
local
function
tidyValNoChange
(
key
,
val
)
return
val
end
local
function
matchesTitle
(
given
,
title
)
local
tp
=
type
(
given
)
return
(
tp
==
'string'
or
tp
==
'number'
)
and
mw
.
title
.
new
(
given
).
prefixedText
==
title
end
local
translate_mt
=
{
__index
=
function
(
t
,
k
)
return
k
end
}
function
arguments
.
getArgs
(
frame
,
options
)
checkType
(
'getArgs'
,
1
,
frame
,
'table'
,
true
)
checkType
(
'getArgs'
,
2
,
options
,
'table'
,
true
)
frame
=
frame
or
{}
options
=
options
or
{}
--[[
-- Set up argument translation.
--]]
options
.
translate
=
options
.
translate
or
{}
if
getmetatable
(
options
.
translate
)
==
nil
then
setmetatable
(
options
.
translate
,
translate_mt
)
end
if
options
.
backtranslate
==
nil
then
options
.
backtranslate
=
{}
for
k
,
v
in
pairs
(
options
.
translate
)
do
options
.
backtranslate
[
v
]
=
k
end
end
if
options
.
backtranslate
and
getmetatable
(
options
.
backtranslate
)
==
nil
then
setmetatable
(
options
.
backtranslate
,
{
__index
=
function
(
t
,
k
)
if
options
.
translate
[
k
]
~=
k
then
return
nil
else
return
k
end
end
})
end
--[[
-- Get the argument tables. If we were passed a valid frame object, get the
-- frame arguments (fargs) and the parent frame arguments (pargs), depending
-- on the options set and on the parent frame's availability. If we weren't
-- passed a valid frame object, we are being called from another Lua module
-- or from the debug console, so assume that we were passed a table of args
-- directly, and assign it to a new variable (luaArgs).
--]]
local
fargs
,
pargs
,
luaArgs
if
type
(
frame
.
args
)
==
'table'
and
type
(
frame
.
getParent
)
==
'function'
then
if
options
.
wrappers
then
--[[
-- The wrappers option makes Module:Arguments look up arguments in
-- either the frame argument table or the parent argument table, but
-- not both. This means that users can use either the #invoke syntax
-- or a wrapper template without the loss of performance associated
-- with looking arguments up in both the frame and the parent frame.
-- Module:Arguments will look up arguments in the parent frame
-- if it finds the parent frame's title in options.wrapper;
-- otherwise it will look up arguments in the frame object passed
-- to getArgs.
--]]
local
parent
=
frame
:
getParent
()
if
not
parent
then
fargs
=
frame
.
args
else
local
title
=
parent
:
getTitle
():
gsub
(
'/????$'
,
''
)
local
found
=
false
if
matchesTitle
(
options
.
wrappers
,
title
)
then
found
=
true
elseif
type
(
options
.
wrappers
)
==
'table'
then
for
_
,
v
in
pairs
(
options
.
wrappers
)
do
if
matchesTitle
(
v
,
title
)
then
found
=
true
break
end
end
end
-- We test for false specifically here so that nil (the default) acts like true.
if
found
or
options
.
frameOnly
==
false
then
pargs
=
parent
.
args
end
if
not
found
or
options
.
parentOnly
==
false
then
fargs
=
frame
.
args
end
end
else
-- options.wrapper isn't set, so check the other options.
if
not
options
.
parentOnly
then
fargs
=
frame
.
args
end
if
not
options
.
frameOnly
then
local
parent
=
frame
:
getParent
()
pargs
=
parent
and
parent
.
args
or
nil
end
end
if
options
.
parentFirst
then
fargs
,
pargs
=
pargs
,
fargs
end
else
luaArgs
=
frame
end
-- Set the order of precedence of the argument tables. If the variables are
-- nil, nothing will be added to the table, which is how we avoid clashes
-- between the frame/parent args and the Lua args.
local
argTables
=
{
fargs
}
argTables
[
#
argTables
+
1
]
=
pargs
argTables
[
#
argTables
+
1
]
=
luaArgs
--[[
-- Generate the tidyVal function. If it has been specified by the user, we
-- use that; if not, we choose one of four functions depending on the
-- options chosen. This is so that we don't have to call the options table
-- every time the function is called.
--]]
local
tidyVal
=
options
.
valueFunc
if
tidyVal
then
if
type
(
tidyVal
)
~=
'function'
then
error
(
"bad value assigned to option 'valueFunc'"
..
'(function expected, got '
..
type
(
tidyVal
)
..
')'
,
2
)
end
elseif
options
.
trim
~=
false
then
if
options
.
removeBlanks
~=
false
then
tidyVal
=
tidyValDefault
else
tidyVal
=
tidyValTrimOnly
end
else
if
options
.
removeBlanks
~=
false
then
tidyVal
=
tidyValRemoveBlanksOnly
else
tidyVal
=
tidyValNoChange
end
end
--[[
-- Set up the args, metaArgs and nilArgs tables. args will be the one
-- accessed from functions, and metaArgs will hold the actual arguments. Nil
-- arguments are memoized in nilArgs, and the metatable connects all of them
-- together.
--]]
local
args
,
metaArgs
,
nilArgs
,
metatable
=
{},
{},
{},
{}
setmetatable
(
args
,
metatable
)
local
function
mergeArgs
(
tables
)
--[[
-- Accepts multiple tables as input and merges their keys and values
-- into one table. If a value is already present it is not overwritten;
-- tables listed earlier have precedence. We are also memoizing nil
-- values, which can be overwritten if they are 's' (soft).
--]]
for
_
,
t
in
ipairs
(
tables
)
do
for
key
,
val
in
pairs
(
t
)
do
if
metaArgs
[
key
]
==
nil
and
nilArgs
[
key
]
~=
'h'
then
local
tidiedVal
=
tidyVal
(
key
,
val
)
if
tidiedVal
==
nil
then
nilArgs
[
key
]
=
's'
else
metaArgs
[
key
]
=
tidiedVal
end
end
end
end
end
--[[
-- Define metatable behaviour. Arguments are memoized in the metaArgs table,
-- and are only fetched from the argument tables once. Fetching arguments
-- from the argument tables is the most resource-intensive step in this
-- module, so we try and avoid it where possible. For this reason, nil
-- arguments are also memoized, in the nilArgs table. Also, we keep a record
-- in the metatable of when pairs and ipairs have been called, so we do not
-- run pairs and ipairs on the argument tables more than once. We also do
-- not run ipairs on fargs and pargs if pairs has already been run, as all
-- the arguments will already have been copied over.
--]]
metatable
.
__index
=
function
(
t
,
key
)
--[[
-- Fetches an argument when the args table is indexed. First we check
-- to see if the value is memoized, and if not we try and fetch it from
-- the argument tables. When we check memoization, we need to check
-- metaArgs before nilArgs, as both can be non-nil at the same time.
-- If the argument is not present in metaArgs, we also check whether
-- pairs has been run yet. If pairs has already been run, we return nil.
-- This is because all the arguments will have already been copied into
-- metaArgs by the mergeArgs function, meaning that any other arguments
-- must be nil.
--]]
if
type
(
key
)
==
'string'
then
key
=
options
.
translate
[
key
]
end
local
val
=
metaArgs
[
key
]
if
val
~=
nil
then
return
val
elseif
metatable
.
donePairs
or
nilArgs
[
key
]
then
return
nil
end
for
_
,
argTable
in
ipairs
(
argTables
)
do
local
argTableVal
=
tidyVal
(
key
,
argTable
[
key
])
if
argTableVal
~=
nil
then
metaArgs
[
key
]
=
argTableVal
return
argTableVal
end
end
nilArgs
[
key
]
=
'h'
return
nil
end
metatable
.
__newindex
=
function
(
t
,
key
,
val
)
-- This function is called when a module tries to add a new value to the
-- args table, or tries to change an existing value.
if
type
(
key
)
==
'string'
then
key
=
options
.
translate
[
key
]
end
if
options
.
readOnly
then
error
(
'could not write to argument table key "'
..
tostring
(
key
)
..
'"; the table is read-only'
,
2
)
elseif
options
.
noOverwrite
and
args
[
key
]
~=
nil
then
error
(
'could not write to argument table key "'
..
tostring
(
key
)
..
'"; overwriting existing arguments is not permitted'
,
2
)
elseif
val
==
nil
then
--[[
-- If the argument is to be overwritten with nil, we need to erase
-- the value in metaArgs, so that __index, __pairs and __ipairs do
-- not use a previous existing value, if present; and we also need
-- to memoize the nil in nilArgs, so that the value isn't looked
-- up in the argument tables if it is accessed again.
--]]
metaArgs
[
key
]
=
nil
nilArgs
[
key
]
=
'h'
else
metaArgs
[
key
]
=
val
end
end
local
function
translatenext
(
invariant
)
local
k
,
v
=
next
(
invariant
.
t
,
invariant
.
k
)
invariant
.
k
=
k
if
k
==
nil
then
return
nil
elseif
type
(
k
)
~=
'string'
or
not
options
.
backtranslate
then
return
k
,
v
else
local
backtranslate
=
options
.
backtranslate
[
k
]
if
backtranslate
==
nil
then
-- Skip this one. This is a tail call, so this won't cause stack overflow
return
translatenext
(
invariant
)
else
return
backtranslate
,
v
end
end
end
metatable
.
__pairs
=
function
()
-- Called when pairs is run on the args table.
if
not
metatable
.
donePairs
then
mergeArgs
(
argTables
)
metatable
.
donePairs
=
true
end
return
translatenext
,
{
t
=
metaArgs
}
end
local
function
inext
(
t
,
i
)
-- This uses our __index metamethod
local
v
=
t
[
i
+
1
]
if
v
~=
nil
then
return
i
+
1
,
v
end
end
metatable
.
__ipairs
=
function
(
t
)
-- Called when ipairs is run on the args table.
return
inext
,
t
,
0
end
return
args
end
return
arguments