Helpful SproutCore Binding Transforms

binding.js

SC.Binding.lt = function (max) {
  return this.transform(function (value, binding) {
    return SC.typeOf(value) === SC.T_NUMBER && value < max;
  });
};

SC.Binding.gt = function (min) {
  return this.transform(function (value, binding) {
    return SC.typeOf(value) === SC.T_NUMBER && value > min;
  });
};

SC.Binding._every = function (paths, compareFn) {
  var keys = [], gate, idx, len, key, binding, transform;

  gate = SC.Object.create();

  for (idx = 0, len = paths.length; idx < len; idx++) {
    key = 'value'+(idx+1);
    keys.push(key);
    binding = paths[idx];
    if (SC.typeOf(binding) === SC.T_STRING) {
      binding = SC.Binding.oneWay(binding);
    }
    binding.to(key, gate).connect();
  }

  transform = function () {
    var values = [], idx, len;
    for (idx = 0, len = keys.length; idx < len; idx++) {
      values.push(this.get(keys[idx]));
    }
    return values.every(compareFn);
  };

  gate.mixin({
    all: SC.Function.property(transform, keys).cacheable()
  });

  gate.registerDependentKey('all', keys);

  return SC.Binding.from('all', gate).oneWay();
};

SC.Binding.all = function () {
  return SC.Binding._every(arguments, function (v) { return !!v; });
};

SC.Binding.none = function () {
  return SC.Binding._every(arguments, function (v) { return !v; });
};