Template and Place holders algorithm

Question

First a quick definition :)

• Template - A string which may contain placeholders (example:"hello [name]")
• Placeholder - A substring whitin square brackets (example: "name" in "hello [name]:).
• Properties map - A valid object with strings as values

I need to write a code that replace placeholders (along with brackets) with the matching values in the properties map.

example: for the following properties map:

{
    "name":"world",
    "my":"beautiful",
    "a":"[b]",
    "b":"c",
    "c":"my"
}

Expected results:

• "hello name" -> "hello name"

• "hello [name]" -> "hello world"

• "[b]" -> "c"

• "[a]" -> "c" (because [a]->[b]->[c])

• "[[b]]" -> "my" (because [[b]]->[c]->my)

• "hello [my] [name]" -> "hello beautiful world"

Answer 1

var map = {
    "name":"world",
    "my":"beautiful",
    "a":"[b]",
    "b":"c",
    "c":"my"
};

var str = "hello [my] [name] [[b]]";

do {
    var strBeforeReplace = str;
    for (var k in map) {
        if (!map.hasOwnProperty(k)) continue;
        var needle = "[" + k + "]";
        str = str.replace(needle, map[k]);
    }
    var strChanged = str !== strBeforeReplace;
} while (strChanged);

document.write(str); //hello beautiful world my