获取对象的所有方法和属性

Question

If I use (on a text frame):

b.selection().fit(FitOptions.frameToContent);

Then it works as expected, this means that the selected object has a fit method.

If I use:

for (var property in b.selection()) {
    b.println(property);
}

On the same selection then it doesn't print a fit method.

If I use this:

function getMethods(obj) {
  var result = [];
  for (var id in obj) {
    try {
      if (typeof(obj[id]) == "function") {
        result.push(id + ": " + obj[id].toString());
      }
    } catch (err) {
      result.push(id + ": inaccessible");
    }
  }
  return result;
}


b.println(getMethods(b.selection()));

Then I don't get the fit method either. And I would really like to know all methods and properties of the selected object. So how do i get them?

Answer 1

When method fit() exists and doesn't shine up in the for-in-loop it is a non-enumerable property.

There are different ways to access the properties of an object:

var obj = b.selection();
for (var p in obj) {
    console.log(p); // --> all enumerable properties of obj AND its prototype
}
Object.keys(obj).forEach(function(p) {
    console.log(p); // --> all enumerable OWN properties of obj, NOT of its prototype
});
Object.getOwnPropertyNames(obj).forEach(function(p) {
    console.log(p); // all enumerable AND non-enumerable OWN properties of obj, NOT of its prototype
});

If you don't find .fit() on one of this ways its not enumerable AND not OWN property of obj, but sits somewhere in the prototype of obj. Then you can do:

var prot = Object.getPrototypeOf(obj);
Object.getOwnPropertyNames(prot).forEach(function(pp) {
    console.log(pp); // --> all enumerable AND non-enumerable properties of obj's prototype
});

Often objects have a bit longer prototype-chain and the property sits somewhere deeper on it. Then you just repeat the last snippet as often as needed:

var prot2 = Object.getPrototypeOf(prot);
Object.getOwnPropertyNames(prot2).forEach( /*...*/ );

To make it complete: Let's say you have found .fit on the obj's prototype prot . Then you can inspect it:

console.log(Object.getOwnPropertyDescriptor(prot.fit));

That outputs an object which shows the value of prot.fit and whether it's enumerable, writable, and configurable or not. The Object.methods and some more FIND HERE .

Answer 2

Or just use b.inspect(obj) . Prints out all properties and values of an object in a recursive manner to the console. See http://basiljs.ch/reference/#inspect

Answer 3

尝试obj.reflect.methods获取所有方法