Changes
Update to allow for unnamed parameters. This is necessary because some string function need to preserve leading / trailing whitespace in order to work properly.
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". Both strings have any leading or trailing whitespace removed before searching.
Important Note: If the "target" string is empty / missing, this function returns a
]====]
function str.str_find( frame )
local source_str new_args = str._getParameters( frame.args., {'source', 'target'} ); local source_str = new_args['source '] or ''; local target_str = frame.args.new_args['target '] or ''; if target_str == '' then
return 1;
end
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
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 also returns 0.
]====]
function str.find( frame )
local source_str new_args = str._getParameters( frame.args., {'source', 'target', 'start', 'plain' } ); local source_str = new_args['source '] or ''; local pattern = frame.args.new_args['target '] or ''; local start_pos = tonumber(frame.args.new_args['start']) or 1; local plain = frame.args.new_args['plain '] or true;
if source_str == '' or pattern == '' then
return start
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
