We don't have any need to support any IE at this point.

On Thursday, June 11, 2020 at 2:08:48 PM UTC-4, stockiNail wrote:
>
> Hi all,
>
> I was facing an annoying issue about the hashcode *$N* property, stored 
> inside the java script object.
>
> I'm using GWT 2.8.2 but no JSNI implementation, only JSInterop objects.
>
> I'm writing an object (JsType native) in order to configure a chart for 
> Chart.js. 
>
> @JsType(isNative = true, name = "Object", namespace = JsPackage.GLOBAL)
>
> Every property is the ID of another object.
>
> But unfortunately I got an error from Chart.js because it is scanning all 
> properties keys to get the objects but it does not recognize the value of 
> *$H*, being a number and not a object.
>
> scales: { 
>   $H: 135, 
>   x: {id: "x", _charbaId: 2, type: "category", axis: "x", display: true, …}, 
>   y: {id: "y", _charbaId: 3, type: "linear", axis: "y", display: true, …} 
> }
>
> It's clear that a hashcode must be stored therefore there is no way to remove 
> it.
>
> Searching for a solution, I have found the *javaemul.internal.ObjectHashing* 
> class which is managing the H$ property, I guess:
>
>  public static native int getHashCode(Object o) /*-{
>     return o.$H || (o.$H = @ObjectHashing::getNextHashId()());
>  }-*/;
>
> I think the definition of H$ property must be changed, in order to define the 
> property "not enumerable" (currently is writable, enumerable and 
> configurable) using *Object.defineProperty()*, as it is reported 
> https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/defineProperty.
>
> The *Object.defineProperty()* method is not supported into Internet Explorer 
> 8 therefore if going to manage the hascode in this way, GWT will drop the 
> support on IE8 as well.
>
> In the J2CL implementation, it looks like already aligned with my proposal:
>
>
> /** 
>   * Utility functions for setting and retrieving system level hashcodes. 
>   */
> class Hashing { 
>    /** 
>      * Gets a hash code on the passed-in object. 
>      * 
>      * @param {*} obj 
>      * @return {number} 
>      * @public 
>      */ 
>      static $getHashCode(obj) { 
>         let o = /** @type {Object} */ (obj); 
>         return o.$systemHashCode || (Object.defineProperties(o, { 
> $systemHashCode: {value: Hashing.$getNextHashId(), enumerable: false} }), 
> o.$systemHashCode); 
>      }
>
> Anyway, as workaround, I'm rewriting the hashcode property for this object, 
> maintaining the same value but setting the property as not enumerale and it 
> seems working.
>
>
>
>

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