JSObjectPropertiesMap - proper usage

[ghost]

It looks like this is an inner wrapper class to assist with maps. If I set a map in context as follows:

    Map<String, Object> pageContext =  new HashMap<String, Object>();
    JSObject oPageContext = new JSObject(this.jsContext, pageContext);
    jsContext.property("pageContext", oPageContext);

Is this the proper way to then reference that map in the context (after running evaluate script and associated call function):

    JSValue _pageContext = jsContext.property("pageContext");
    Map<String, Object> map = (Map<String, Object> _pageContext.toObject();

thx, appreciate the assist.

[ericwlange]

It seems that I have mistakenly made JSObjectPropertiesMap package local. It should be public. I will fix that for the next release. Unfortunately, it will be difficult to use without reflections unless it is public.

The intent was to enable a convenient method of setting JSObject properties using the Map interface. So the correct way to use it should be:

JSValue _pageContext = jsContext.property("pageContext");
Map<String, JSValue> map = new JSObjectPropertiesMap<>(_pageContext.toObject(), JSValue.class);

I recommend using JSValue as a generic type rather than Object because not all objects can be translated into Javascript values. Or, if your object uses only one type, you can specify that type, as in: Map<String, Integer> map = new JSObjectPropertiessMap<>(_pageContext, Integer.class);

But because the class is not public, this won't work. If you really want to use it, there are two choices: (1) add public in front of the class in JSObjectPropertiesMap.java and build the library yourself, or (2) use reflections:

Class<?> cl = Class.forName("org.liquidplayer.javascript.JSObjectPropertiesMap");
Constructor<?> cons = cl.getConstructor(JSObject.class, Class.class);
Object inst = cons.newInstance(_pageContext.toObject(), JSValue.class);
Map<String, JSValue> map = (Map<String, JSValue>) inst;

You'll also need to wrap this in a try/catch block because there are several exceptions that can theoretically occur, although if your parameters are right, it should work fine.

As an aside, I had intended to just allow JSObject to always implement the Map inteface, however, in Java, I learned, an object cannot implement both Map and List!! This is because they share a single method, remove, which has different return types in each implementation! I wanted JSArray (which is also a JSObject) be able to be used as a generic List. And so I couldn't do both. So to still make this possible, JSObjectPropertiesMap is just a shadow object for some JSObject. Just a little trivia for you.

I will mark this as a bug and fix. Thanks for reporting.

[ericwlange]

Fixed in 8cbe527e66dd7c57acc23f02c44be3d7f9bbdaab.

[ghost]

Sounds good, for now I will mark class public and run a build. Appreciate it.

…

Sent from my iPhone

On Mar 15, 2017, at 4:24 AM, Eric Lange ***@***.***> wrote: It seems that I have mistakenly made JSObjectPropertiesMap package local. It should be public. I will fix that for the next release. Unfortunately, it will be difficult to use without reflections unless it is public. The intent was to enable a convenient method of setting JSObject properties using the Map interface. So the correct way to use it should be: JSValue _pageContext = jsContext.property("pageContext"); Map<String, JSValue> map = new JSObjectPropertiesMap<>(_pageContext.toObject(), JSValue.class); I recommend using JSValue as a generic type rather than Object because not all objects can be translated into Javascript values. Or, if your object uses only one type, you can specify that type, as in: Map<String, Integer> map = new JSObjectPropertiessMap<>(_pageContext, Integer.class); But because the class is not public, this won't work. If you really want to use it, there are two choices: (1) add public in front of the class in JSObjectPropertiesMap.java and build the library yourself, or (2) use reflections: Class<?> cl = Class.forName("org.liquidplayer.javascript.JSObjectPropertiesMap"); Constructor<?> cons = cl.getConstructor(JSObject.class, Class.class); Object inst = cons.newInstance(_pageContext.toObject(), JSValue.class); Map<String, JSValue> map = (Map<String, JSValue>) inst; You'll also need to wrap this in a try/catch block because there are several exceptions that can theoretically occur, although if your parameters are right, it should work fine. As an aside, I had intended to just allow JSObject to always implement the Map inteface, however, in Java, I learned, an object cannot implement both Map and List!! This is because they share a single method, remove, which has different return types in each implementation! I wanted JSArray (which is also a JSObject) be able to be used as a generic List. And so I couldn't do both. So to still make this possible, JSObjectPropertiesMap is just a shadow object for some JSObject. Just a little trivia for you. I will mark this as a bug and fix. Thanks for reporting. — You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub, or mute the thread.

[ericwlange]

This is fixed in v0.2.1.