Module:Sandbox/Wnt/FindAndReplace

 ---- NOTE: while I haven't looked through quite carefully enough, I think that [[Module:String]]
 ---- can do everything that this can do.  I may put it up for deletion soon.
 ---- Sorry, this doesn't work for many applications because all templates are destroyed.  It does work on plain text though.

---- This module is meant to be processed by putting 
 ---- "{{#invoke:FindAndReplace|main|(string to find)|(string to replace)}}"
 ---- into an existing page.  Add "|pattern=yes" to enjoy all the wild and wooly
 ---- features of Lua pattern strings.  This should deliver back all the text,
 ---- as modified, in wiki source form, for you to copy and paste back into the
 ---- page while editing.  Caveat: I don't presently know if things like comments
 ---- will be lost.  This is intended as a handy tool for editors who don't have
 ---- find and replace on their browser and don't want to open another program -
 ---- or to provide better Lua find and replace where their word processors come
 ---- up short.  NOTE that text MUST be saved to be processed with this unless
 ---- you use an additional parameter |input=(the text to find and replace from)

local p = {}

function p.main(frame)
   local args=frame.args
   local parent=frame.getParent(frame)
   local pargs={}
   if parent then pargs=parent.args end
   local find=args.find or pargs.find or args[1] or pargs[1]
   if not(find) then return "error you need to say what to find! (first unnamed parameter ''or'' find=(text)" end
   local replace=args.replace or pargs.replace or args[2] or pargs[2] or ""
   local pattern=args.pattern or pargs.pattern or "no"
   if pattern=="no" then pattern = nil end
   local input=args.input or pargs.input or args[3] or pargs[3] or ""
   if input == nil or input == "" then return "failed to get any text" end
   input=mw.ustring.gsub(input,"{{#invoke:FindAndReplace.-}}","") or input --we don't want shrapnel from this usage in the new page.
   if not(pattern) then find=string.gsub(find,"[%^%$%(%)%%%.%[%]%*%+%-%?%]]","%%1") end -- exterminate all delimiters
   input=mw.ustring.gsub(input,find,replace)
    ---- I have no idea why {{x gets returned as [[:Template:x but I don't like it.
   --input=mw.ustring.gsub(input,[=[%[%[:Template:]=].."(.-)"..[=[%]%]]=],"{{%1}}")
   -- no good - it still loses all the parameters out of all the templates!
   return frame.preprocess(frame, "<pre><nowiki>" .. input .. [[</nowiki></pre>]])
end

return p

-- I wonder if there's a way to put this directly back into an open edit window...