Ghetto fabulous templating system. More ghetto than fabulous.

ba-ghettotmpl.js

// Ghetto fabulous template system for replacing values in strings. If {{.foo}}
// or {{.bar[0].baz}} is encountered (leading . or ( or [ char), attempt to
// access properties of data object like `data.foo` or `data.bar[0].baz`.
// Alternately, if {{foo}} or {{bar("baz")}} is encountered (no leading dot),
// simply evaluate `foo` or `bar("baz")`. If an error occurs, return empty
// string. Oh yeah, you have to pass the result of ghettoTmpl to eval. :)

var ghettoTmpl = function(data, str) {
  if ( typeof data === "string" ) {
    str = data;
    data = {};
  }
  GHETTO_TMPL_DATA = data;
  GHETTO_TMPL_STR = str;
  return "["
    + "GHETTO_TMPL_STR.replace(/\\{\\{(([.[(])?.*?)\\}\\}/g, function(_, str, dot) {"
    + "return eval('try{' + (dot ? 'GHETTO_TMPL_DATA' : '') + str + '}catch(e){\"\"}');"
    + "})"
    + ",GHETTO_TMPL_DATA = GHETTO_TMPL_STR = null][0]";
}

usage.js

var scope = "global";

// scope: global 
console.log(eval(ghettoTmpl("scope: {{scope}} {{wont-error}} {{.wont-error}}")));

function test() {
  var scope = "local";
  var obj = {
    prop: 123,
    getter: function() { return this.prop; }
  };
  // scope: local prop: 123 123
  console.log(eval(ghettoTmpl("scope: {{scope}} prop: {{obj.prop}} {{obj.getter()}}")));
  // scope: local prop: 123 123
  console.log(eval(ghettoTmpl(obj, "scope: {{scope}} prop: {{.prop}} {{.getter()}}")));
}

test();

I'd reorder the args and have str come first. data is optional.

Ok, Mike, data is now optional... but it's still first.