Could you explain why im failed to get backlink values from the result of the matched regular expression and apply it to the modification before an effective replacement?
The expected result replaces, for example, the string ".coord('X','Y')" with "X * Y" . But if X > to some value, divide this value by 2, and then replace this new value.
Here is the im code that is currently being tested:
See /*>>1<<*/ and /*>>2<<*/ and /*>>3<<*/ , this is where I got stuck!
I would like to be able to apply a modification of backrefrences before replacement depending on the values of backlinks.
The difference between /*>>2<<*/ and /*>>3<<*/ is just an anonymous self call function
The method /*>>2<<*/ is the expected working solution, since i can understand it. But, strangely enough, the replacement does not work correctly, replacing the alias $1 * $2 , and not the value ...?
You can check jsfiddle
//string to test ".coord('125','255')" //array of regex pattern and replacement //just one for the example //for this example, pattern matching alphanumerics is not necessary (only decimal in coord) but keep it as it var regexes = [ //FORMAT is array of [PATTERN,REPLACEMENT] /*.coord("X","Y")*/ [/\.coord\(['"]([\w]+)['"],['"]?([\w:\.\\]+)['"]?\)/g, '$1 * $2'] ]; function testReg(inputText, $output) { //using regex for (var i = 0; i < regexes.length; i++) { /*==>**1**/ //this one works as usual but dont let me get backreferences values $output.val(inputText.replace(regexes[i][0], regexes[i][2])); /*==>**2**/ //this one should works as i understand it $output.val(inputText.replace(regexes[i][0], function(match, $1, $2, $3, $4) { $1 = checkReplace(match, $1, $2, $3, $4); //here want using $1 modified value in replacement return regexes[i][3]; })); /*==>**3**/ //this one is just a test by self call anonymous function $output.val(inputText.replace(regexes[i][0], function(match, $1, $2, $3, $4) { $1 = checkReplace(match, $1, $2, $3, $4); //here want using $1 modified value in replacement return regexes[i][4]; }())); inputText = $output.val(); } } function checkReplace(match, $1, $2, $3, $4) { console.log(match + ':::' + $1 + ':::' + $2 + ':::' + $3 + ':::' + $4); //HERE i should be able if lets say $1 > 200 divide it by 2 //then returning $1 value if($1 > 200) $1 = parseInt($1 / 2); return $1; }
Of course, I missed something, but I can not understand!
Thanks for your help, hello.
EDIT WORKING METHOD: Lastly, get it as directed by Eric:
The main thing is that the function returns literal text for substitute, and not a string that is parsed for backlinks.
JSFIDDLE
So, the full working code: (note that replacing the template will change for each matching template, and speed code optimization is not a problem here, I will save it like that)
$('#btn').click(function() { testReg($('#input').val(), $('#output')); }); //array of regex pattern and replacement //just one for the example var regexes = [ //FORMAT is array of [PATTERN,REPLACEMENT] /*.coord("X","Y")*/ [/\.coord\(['"]([\w]+)['"],['"]?([\w:\.\\]+)['"]?\)/g, '$1 * $2'] ]; function testReg(inputText, $output) { //using regex for (var i = 0; i < regexes.length; i++) { $output.val(inputText.replace(regexes[i][0], function(match, $1, $2, $3, $4) { var checkedValues = checkReplace(match, $1, $2, $3, $4); $1 = checkedValues[0]; $2 = checkedValues[1]; regexes[i][1] = regexes[i][1].replace('$1', $1).replace('$2', $2); return regexes[i][1]; })); inputText = $output.val(); } } function checkReplace(match, $1, $2, $3, $4) { console.log(match + ':::' + $1 + ':::' + $2 + ':::' + $3 + ':::' + $4); if ($1 > 200) $1 = parseInt($1 / 2); if ($2 > 200) $2 = parseInt($2 / 2); return [$1,$2]; }