toJSON() serialization

[stevenvachon]

I think it'd be handy if all URL instances would serialize to the value of href.

[annevk]

toString() does that. For toJSON() I can imagine folks might want to see the individual components too, so I'm not really sure it makes sense to define a default there.

[stevenvachon]

The individual components don't show up with JSON.stringify() because they are properties of prototype.

[annevk]

I think you're referring to something Chrome used to do at some point, not the standard way it's supposed to work.

[Sebmaster]

@annevk Are you saying the spec shouldn't define a default and should just always return "{}", or are you saying that this should already work differently (i.e. list all getters)?

[stevenvachon]

Firefox v48 stringifies all properties/getters, but whatwg-url does not.

[domenic]

Then Firefox is not following the spec for JSON.stringify. I suspect something else is going on.

[stevenvachon]

Chrome v52 also results in {}.

@domenic that's not what @annevk has said.

[domenic]

Yes. I think @annevk is confused. The JSON.stringify spec is unambiguous.

[stevenvachon]

console.log( JSON.stringify(new Date()) )

produces:

"2016-08-08T23:29:58.183Z"

[annevk]

I didn't say that Firefox stringifies all properties/getters?

All I was saying that we could define something here, but it's not clear to me what the best option is.

[jasnell]

Having a URL.prototype.toJSON() that essentially just returned URL.prototype.href would likely be the best option given that it's likely what most would expect or need.

[annevk]

If .toJSON() returns .href you might as well write .href, no? Where would this come up as being useful?

[stevenvachon]

@annevk when serializing the URL indirectly, as part of another object:

JSON.stringify({ key: new URL("http://domain/") });

[annevk]

@tobie would we just define toJSON for this? I saw IDL might change around this.

[tobie]

@annevk right, that's being discussed in whatwg/webidl#188. Haven't looked into it myself yet.

[domenic]

Apparently it is currently disallowed to create an operation named toJSON:

The identifier of any of the abovementioned IDL constructs must not be “constructor”, “toString”, “toJSON”, or begin with a U+005F LOW LINE ("_") character. These are known as reserved identifiers.

So I guess the way to currently do this would be to just define serializer; and have prose say that it returns the same value as running the href algorithm. We could update it as Web IDL gets its serializer business together.

[bzbarsky]

In terms of the current IDL spec, you can write:

serializer = href;

to get the desired behavior, no? But as mentioned in whatwg/webidl#188 I think the current spec is way overdesigned.

[annevk]

I created a PR for this, #229. Please review! Will write a test too.

[styfle]

I agree with @stevenvachon. As an end user, I would expect a URL to serialize to the full href string the same way Date serializes to a full ISO string.

During deserialization, the user can pass the string into the URL() constructor the same way you pass the ISO string into the Date() constructor.

Here's an example:

var data = {
  theUrl: new URL("https://example.com/foo"),
  theDate: new Date("2017-02-02T17:06:41.229Z")
};

var str = JSON.stringify(data);
// "{"theUrl":"https://example.com/foo","theDate":"2017-02-02T17:06:41.229Z"}"

var clone = JSON.parse(str);

new Date(clone.theDate).valueOf() === data.theDate.valueOf(); // Current this is true
new URL(clone.theUrl).href === data.theUrl.href; // I would expect this to be true

Note that the Date does not stringify as {fullYear: 2017, month: 1, date: 2}. Neither should the URL.

[annevk]

Browser bugs (none for Edge as it doesn't implement the API yet):

• https://bugzilla.mozilla.org/show_bug.cgi?id=1337702
• https://bugs.webkit.org/show_bug.cgi?id=167979
• https://bugs.chromium.org/p/chromium/issues/detail?id=689891

[annevk]

It was pointed out to me Edge does implement the API! Oops. I filed https://developer.microsoft.com/en-us/microsoft-edge/platform/issues/10867624/ on Edge.

[styfle]

This just landed in node.js 7.7.0 today 🎉
That was quick! 🥇