Question

I’m writing a code for live replacement of specific words in a text field as the user types.

I’m using regex and javascript:
The first array has the regular expressions to be found, and the second array has the words that should replace any them.

source = new Array(/\srsrs\s/,/\sñ\s/,/\snaum\s/,/\svc\s/,/\scd\s/,/\sOq\s/,/\soke\s/,/\so\sq\s/,
                /\soque\s/,/\soqe\s/,/\spq\s/,/\sq\s/,/\sp\/\s/g,/\spra\s/,/\sp\s/,/\stbm\s/,
                /\stb\s/,/\std\s/,/\sblz\s/,/\saki\s/,/\svlw\s/,/\smara\s/,/\sqlq\s/,/\sqq\s/,
                /\srpz\s/,/\smsm\s/,/\smto\s/,/\smtu\s/,/\sqro\s/,/\sqdo\s/,/\sqd\s/,/\sqnd\s/,
                /\sqto\s/,/\sqm\s/,/\sjah\s/, /\sc\/\s/,/\scmg\s/,/\s\+\sou\s\-\s/,/\sflw\s/,
                /\sxau\s/,/\sto\s/,/\sta\s/);
after = new Array("risos","não","não","você","cadê","o que","o que","o que","o que","o que","porque",
            "que","para","para","para","também","também","tudo","beleza","aqui","valeu","maravilhoso",
            "qualquer","qualquer","rapaz","mesmo","muito","muito","quero","quando","quando","quando",
            "quanto","quem","Já","com","comego","mais ou menos","falow","tchau","estou","está");

This is the function that does the replacement:

function replacement(){
for(i=0; i<source.length; i++){
    newtext = " "+document.getElementById("translation").value+" ";
    console.log(newtext);
    if(myregex = newtext.match(source[i])){
    newafter = after[i];
    rafael = myregex+" ";
    document.getElementById("translation").value = document.getElementById("translation").value.replace(rafael, newafter);
    }
}
}

My problem is every time the function is called to replace an expression with only one letter, the replacement is being made on the first occurrence of that letter, even within a word. I thought looking for that letter with \s before and after would solve it, but it didn’t.

Answer 1

If by “live replacement” you mean calling function replacement at each keystroke then \b at the end will not help you, you should indeed use \s. However in your replacement function your are adding a space to the text field value so your single character words are triggering the replacement.

Here is my refactoring of your code :

(function () { // wrap in immediate function to hide local variables
  source = [ [/\brsrs\s$/, "risos"], // place reg exp and replacement next to each other
             [/\b(ñ|naum)\s$/, "não"], // note combined regexps
             [/\bvc\s$/, "você"]
             // ...
           ]; // not also use of array literals in place of new Array

  document.getElementById ("translation"​​​​​​​).addEventListener ('keyup', function (ev) {
    var t =  this.value  // fetch text area value
      , m
      , i = source.length;

    while (i--) // for each possible match
      if ((m = t.match(source[i][0]))) { // does this one match ?
        // replace match : first remove the match string (m[0]) from the end of 
        // the text string, then add the replacement word followed by a space
        this.value = t.slice (0, -m[0].length) + source[i][1] + ' '; 
        return; // done
      }
  }, false);  
}) ();​

And the fiddle is : http://jsfiddle.net/jFYuV