Modul:String

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Denne modulen brukes på over 230 000 sider.
Det anbefales at endringer testes i en sandkasse før de legges inn. Diskuter gjerne også endringer på diskusjonssiden først.

Denne modulen er tenkt å gi tilgang til grunnleggende string-funksjoner.

De fleste funksjonene gitt av denne modulen kan kalles med navngitte parametre, ubenevnte parametre, eller en blanding. Hvis navngitte parametre brukes, vil Mediawiki automatisk fjerne eventuelle mellomrom før eller etter parameteren. Avhengig av bruksområde, kan det være fordelaktig å enten bevare eller fjerne denne type mellomrom.

Modul:string • Modul:string/sandkasse • forskjellig (diff)

Globale valg

ignore_errors: Hvis satt til 'true' eller '1', vil en feilsituasjon returnere en tom tekststreng fremfor en feilmelding
error_category: Hvis en feil oppstår, angis navnet til en kategori som skal inkluderes med feilmeldingen. Standardkategorien er Kategori:Feilmeldinger fra String-modulen.
no_category: Hvis satt til 'true' eller '1', vil det ikke returneres noen kategori når en feil genereres.

Testside for denne modulen finnes på Modul:String/testtilfeller.

len

Denne funksjonen returnerer lengden for målstrengen.

Bruk:

{{#invoke:String|len|målstreng}}

eller

{{#invoke:String|len|s= målstreng }}

Parametre:

s: Strengen hvis lengde skal returneres

sub

Denne funksjonen returnerer en substreng av målstrengen ved gitte indekser.

Bruk:

{{#invoke:String|sub|målstreng|startindeks|sluttindes}}

eller

{{#invoke:String|sub|s= målstreng |i= startindeks |j= sluttindeks }}

Parametre:

s: Strengen som det skal returneres en del av
i: Første indeks av substrengen som skal returneres. Standard er satt til 1.
j: Siste indeks av substrengen som skal returneres. Standard er siste tegn.

Det første tegnet i strengen er gitt en indeks på 1. Hvis enten i eller j har negativ verdi, tilsvarer det å velge et tegn ved å telle fra slutten og mot starten av strengen. Det vil si at en verdi på -1 er det samme som å velge det siste tegnet i strengen.

Hvis de forespurte indeksene er utenfor rekkevidde for den gitte strengen, genereres det en feilmelding.

sublength

This function implements the features of {{Str sub old}} and is kept in order to maintain these older templates.

match

This function returns a substring from the source string that matches a specified pattern.

Usage:

{{#invoke:String|match|source_string|pattern_string|start_index|match_number|plain_flag|nomatch_output}}

OR

{{#invoke:String|match|s= source_string |pattern= pattern_string |start= start_index|match= match_number|plain= plain_flag |nomatch= nomatch_output }}

Parameters:

s: The string to search
pattern: The pattern or string to find within the string
start: The index within the source string to start the search. The first character of the string has index 1. Defaults to 1.
match: In some cases it may be possible to make multiple matches on a single string. This specifies which match to return, where the first match is match= 1. If a negative number is specified then a match is returned counting from the last match. Hence match = -1 is the same as requesting the last match. Defaults to 1.
plain: A flag indicating that the pattern should be understood as plain text. Defaults to false.
nomatch: If no match is found, output the "nomatch" value rather than an error.

If the match_number or start_index are out of range for the string being queried, then this function generates an error. An error is also generated if no match is found. If one adds the parameter ignore_errors=true, then the error will be suppressed and an empty string will be returned on any failure.

For information on constructing Lua patterns, a form of regular expression, see:

pos

This function returns a single character from the target string at position pos.

Usage:

{{#invoke:String|pos|target_string|index_value}}

OR

{{#invoke:String|pos|target= target_string |pos= index_value }}

Parameters:

target: The string to search
pos: The index for the character to return

The first character has an index value of 1.

If one requests a negative value, this function will select a character by counting backwards from the end of the string. In other words pos = -1 is the same as asking for the last character.

A requested value of zero, or a value greater than the length of the string returns an error.

str_find

This function duplicates the behavior of {{str_find}}, including all of its quirks. This is provided in order to support existing templates, but is NOT RECOMMENDED for new code and templates. New code is recommended to use the "find" function instead.

Returns the first index in "source" that is a match to "target". Indexing is 1-based, and the function returns -1 if the "target" string is not present in "source".

Important Note: If the "target" string is empty / missing, this function returns a value of "1", which is generally unexpected behavior, and must be accounted for separatetly.

find

This function allows one to search for a target string or pattern within another string.

Usage:

{{#invoke:String|find|source_str|target_string|start_index|plain_flag}}

OR

{{#invoke:String|find|source= source_str |target= target_str |start= start_index|plain= plain_flag }}

Parameters:

source: The string to search
target: The string or pattern to find within source
start: The index within the source string to start the search, defaults to 1
plain: Boolean flag indicating that target should be understood as plain text and not as a Lua-style regular expression, defaults to true

This function returns the first index >= "start" where "target" can be found within "source". Indices are 1-based. If "target" is not found, then this function returns 0. If either "source" or "target" are missing / empty, this function also returns 0.

This function should be safe for UTF-8 strings.

replace

This function allows one to replace a target string or pattern within another string.

Usage:

{{#invoke:String|replace|source_str|pattern_string|replace_string|replacement_count|plain_flag}}

OR

{{#invoke:String|replace|source= source_string |pattern= pattern_string|replace= replace_string |count= replacement_count |plain= plain_flag }}

Parameters:

source: The string to search
pattern: The string or pattern to find within source
replace: The replacement text
count: The number of occurrences to replace; defaults to all
plain: Boolean flag indicating that pattern should be understood as plain text and not as a Scribunto ustring pattern (a unicode-friendly Lua-style regular expression); defaults to true

rep

Repeats a string n times. A simple function to pipe string.rep to templates. Usage:

{{#invoke:String|rep|source|count}}

Parameters:

source: The string to repeat
count: The number of repetitions.

Example {{#invoke:String|rep|hello|3}} gives Skriptfeil: Funksjonen «rep» eksisterer ikke.

local str = {}

function str.len( frame )
    return mw.ustring.len( frame.args.s )
end

function str.sub( frame )
    return mw.ustring.sub( frame.args.s, tonumber( frame.args.i ), tonumber( frame.args.j ) )
end

function str.sublength( frame )
    local i = tonumber( frame.args.i ) or 0
    local len = tonumber( frame.args.len )
    return mw.ustring.sub( frame.args.s, i + 1, len and ( i + len ) )
end

function str.match( frame )
    return mw.ustring.match( frame.args.s, frame.args.pattern, tonumber( frame.args.i ) )
end

--[====[
pos

This function returns a single character from the target string at position pos.

Usage:
{{#invoke:String|pos|target_string|index_value}}
OR
{{#invoke:String|pos|target=target_string|pos=index_value}}

Parameters
    target: The string to search
    pos: The index for the character to return

If invoked using named parameters, Mediawiki will automatically remove any leading or
trailing whitespace from the target string.  In some circumstances this is desirable, in 
other cases one may want to preserve the whitespace.

The first character has an index value of 1.

If one requests a negative value, this function will select a character by counting backwards 
from the end of the string.  In other words pos = -1 is the same as asking for the last character.

A requested value of zero, or a value greater than the length of the string returns an error.
]====]
function str.pos( frame )
    local new_args = str._getParameters( frame.args, {'target', 'pos'} );
    local target_str = new_args['target'] or '';
    local pos = tonumber( new_args['pos'] ) or 0;

    if pos == 0 or math.abs(pos) > mw.ustring.len( target_str ) then
        return '<strong class="error">String index out of range</strong>';
    end    
    
    return mw.ustring.sub( target_str, pos, pos );
end

--[====[
str_find

This function duplicates the behavior of {{str_find}}, including all of its quirks.
This is provided in order to support existing templates, but is NOT RECOMMENDED for 
new code and templates.  New code is recommended to use the "find" function instead.

Returns the first index in "source" that is a match to "target".  Indexing is 1-based,
and the function returns -1 if the "target" string is not present in "source".

Important Note: If the "target" string is empty / missing, this function returns a
value of "1", which is generally unexpected behavior, and must be accounted for
separatetly.
]====]
function str.str_find( frame )
    local new_args = str._getParameters( frame.args, {'source', 'target'} );
    local source_str = new_args['source'] or '';
    local target_str = new_args['target'] or '';

    if target_str == '' then
        return 1;
    end    
    
    local start = mw.ustring.find( source_str, target_str, 1, true )
    if start == nil then
        start = -1
    end
    
    return start
end

--[====[
find

This function allows one to search for a target string or pattern within another
string.

Usage:
{{#invoke:String|find|source_str|target_string|start_index|plain_flag}}
OR
{{#invoke:String|find|source=source_str|target=target_str|start=start_index|plain=plain_flag}}

Parameters
    source: The string to search
    target: The string or pattern to find within source
    start: The index within the source string to start the search, defaults to 1
    plain: Boolean flag indicating that target should be understood as plain
        text and not as a Lua style regular expression, defaults to true

If invoked using named parameters, Mediawiki will automatically remove any leading or
trailing whitespace from the parameter.  In some circumstances this is desirable, in 
other cases one may want to preserve the whitespace.

This function returns the first index >= "start" where "target" can be found 
within "source".  Indices are 1-based.  If "target" is not found, then this 
function returns 0.  If either "source" or "target" are missing / empty, this
function also returns 0.

This function should be safe for UTF-8 strings.
]====]
function str.find( frame )
    local new_args = str._getParameters( frame.args, {'source', 'target', 'start', 'plain' } ); 
    local source_str = new_args['source'] or '';
    local pattern = new_args['target'] or '';
    local start_pos = tonumber(new_args['start']) or 1;
    local plain = new_args['plain'] or true;
        
    if source_str == '' or pattern == '' then
        return 0;
    end    
    
    if type( plain ) == 'string' then
        plain = plain:lower();
        if plain == 'false' or plain == 'no' or plain == '0' then
            plain = false;
        else
            plain = true;
        end    
    end

    local start = mw.ustring.find( source_str, pattern, start_pos, plain )
    if start == nil then
        start = 0
    end
    
    return start
end

--[====[
replace_plain

This function allows one to replace a target string or pattern within another
string.

Usage:
{{#invoke:String|replace_plain|source_str|pattern_string|replace_string|firstonlyflag}}
OR
{{#invoke:String|replace_plain|source=source_str|pattern=pattern_str|replace=replace_string|firstonly=firstonlyflag}}

Parameters
    source: The string to search
    patten: The string or pattern to find within source
    replace: The replacement text
    firstonly: Boolean flag indicating that only the first occurence found should be replaced
]====]
function str.replace_plain( frame )
    local new_args = str._getParameters( frame.args, {'source', 'pattern', 'replace', 'firstonly' } ); 
    local source_str = new_args['source'] or '';
    local pattern = new_args['pattern'] or '';
    local replace = new_args['replace'] or '';
    local firstonly = new_args['firstonly'] or '';
    firstonly = firstonly:lower();
        
    if source_str == '' or pattern == '' then
        return source_str;
    end    

    local pattern_plain = mw.ustring.gsub(pattern, '%%', '%%%%');
    local replace_plain = mw.ustring.gsub(replace, '%%', '%%%%');

    if firstonly == 'true' or firstonly == 'yes' or firstonly == '1' then
        local result = mw.ustring.gsub( source_str, pattern_plain, replace_plain, 1 );
    else
        local result = mw.ustring.gsub( source_str, pattern_plain, replace_plain, n );
    end

    return result;
end

--[====[
Helper function that populates the argument list given that user may need to use a mix of
named and unnamed parameters.  This is relevant because named parameters are not
identical to unnamed parameters due to string trimming, and when dealing with strings
we sometimes want to either preserve or remove that whitespace depending on the application.
]====]
function str._getParameters( frame_args, arg_list )
    local new_args = {};
    local index = 1;
    local value;
    
    for i,arg in ipairs( arg_list ) do
        value = frame_args[arg]
        if value == nil then
            value = frame_args[index];
            index = index + 1;
        end
        new_args[arg] = value;
    end
    
    return new_args;
end        

return str