Sorry, figured it out. I needed a namespace:
@JsType(isNative = true, namespace = JsPackage.GLOBAL)
public class RTCPeerConnection {
public RTCPeerConnection(JavaScriptObject iceServersJsoArray) {
super();
}
public native void close();
}
Now working great! 🙂
On Wednesday 10 April 2024 at 7:27:42 pm UTC+10 Craig Mitchell wrote:
> You weren't kidding. I checked the compiled JS, and there it is (with
> some smarts to minimise the JS it looks like):
> this.a = new U2b(d,c,(n = {
> iceServers: m
> },
> new RTCPeerConnection(n)));
>
> Thanks for letting me know about JsonUtils.safeEval(...) That is a better
> option.
>
> I never had much luck with JsInterop. I just tried it again, trying to
> map the RTCPeerConnection
> <https://developer.mozilla.org/en-US/docs/Web/API/RTCPeerConnection/RTCPeerConnection>,
>
> but it doesn't work giving me "TypeError: Cannot read properties of
> undefined" when I try to instanciate it. I also can't debug it, as I can't
> step into the constructor to see what's going wrong.
>
> This was my failed attempt:
>
> @JsType(isNative = true)
> public class RTCPeerConnection {
> @JsConstructor
> public RTCPeerConnection(JavaScriptObject iceServersJsoArray) {
> super();
> }
> public native void close();
> }
>
>
> On Sunday 7 April 2024 at 4:20:48 am UTC+10 Thomas Broyer wrote:
>
>> There's no escaping. You have a string value, it stays a string value. If
>> its content is JSON representing an array and you want that array, then
>> indeed you have to parse the JSON.
>>
>> It looks like there's a major misunderstanding about what GWT does with
>> your code, and/or possibly where/when the code runs or something.
>> GWT "only" translates the Java syntax to JS (and also optimizes
>> everything), and therefore comes with a library of classes that emulates
>> the Java runtime core classes so they can also be translated the same way
>> as your code. JSNI is an escape hatch to be able to "put JS syntax inside
>> your Java syntax", but that's all.
>> In other words, if you have a string "[ 42, true, null ]" in a variable
>> (that you retrieved from your server), if you call that method, it's
>> exactly equivalent to this JS:
>> var iceServersJson = "[ 42, true, null ]";
>> var peerConnectionConfig = {
>> iceServers: iceServersJson
>> };
>> i.e. the peerConnectionConfig object has an iceServers property whose
>> value is just the iceServersJson string value.
>> GWT won't "magically" generate JS code at runtime replacing the value
>> as-is to form some new JS each time, i.e. it *won't* become:
>> var peerConnectionConfig = {
>> iceServers: [ 42, true, null ]
>> };
>> No, really, that Java/JSNI function is transformed to this JS function:
>> function createPeerConnection(iceServersJson) {
>> var peerConnectionConfig = {
>> iceServers: iceServersJson
>> };
>> return new RTCPeerConnection(peerConnectionConfig);
>> }
>> and then at one point you call it. It's your job to give it either a
>> string value or parse the string value as JSON and passe the result.
>>
>> Kudos to resurrecting a 15 years old post though! 🤣
>>
>> BTW, you may want to prefer JsonUtils.safeEval(iceServersJson) here:
>> https://www.gwtproject.org/javadoc/latest/com/google/gwt/core/client/JsonUtils.html
>>
>> (and actually you may want to move to using JsInterop rather than JSNI, and
>> maybe Elemental 2)
>>
>> On Saturday, April 6, 2024 at 8:01:13 AM UTC+2 [email protected]
>> wrote:
>>
>>> I ran into this. GWT is too smart sometimes. :)
>>>
>>> For my example, I was querying an API for WebRTC ICE servers, which
>>> returned a string which was a JSON array.
>>>
>>> When I had:
>>>
>>> private static native JavaScriptObject createPeerConnection(String
>>> iceServersJson) /*-{
>>> var peerConnectionConfig = {
>>> iceServers: iceServersJson
>>> };
>>> return new RTCPeerConnection(peerConnectionConfig);
>>> }-*/;
>>>
>>> GWT excaped the quotes, so iceServers switched from an array, to just a
>>> string, exactly like I asked it to.
>>>
>>> So, really, I needed what Thomas suggested:
>>>
>>> JavaScriptObject iceServersObj = ((JSONArray)JSONParser.parseStrict(
>>> iceServersJson)).getJavaScriptObject();
>>>
>>> private static native JavaScriptObject
>>> createPeerConnection(JavaScriptObject
>>> iceServersJson) /*-{
>>> var peerConnectionConfig = {
>>> iceServers: iceServersJson
>>> };
>>> return new RTCPeerConnection(peerConnectionConfig);
>>> }-*/;
>>>
>>> Now I'm telling GWT it's a JSO, and GWT knows not to escape it.
>>>
>>> On Monday 9 November 2009 at 10:25:24 pm UTC+11 Thomas Broyer wrote:
>>>
>>>>
>>>>
>>>> On Nov 9, 11:47 am, peterk <[email protected]> wrote:
>>>> > I'm having some trouble dealing with escaping and unescaping of Java
>>>> > strings for encoding in JSON.
>>>> >
>>>> > I use JSONString to encode a Java string and that seems to work ok.
>>>> > For example, newlines turn into \n, tabs turn into \t and so on.
>>>> >
>>>> > However, given this escaped sequence back, how to I turn this back
>>>> > into an unescaped javastring wheren \n is turned into a newline and
>>>> so
>>>> > on?
>>>> >
>>>> > If I use stringvalue() on the JSONString it just gives back the same
>>>> > json encoded string with the \n and \t encoding etc.
>>>> >
>>>> > Anyone have any ideas? :)
>>>>
>>>> JSONParser.parse? ;-)
>>>
>>>
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