How to create GWT JsArray?

You don't have much choices: creating a JsArrayString and adding to it, or using JSNI. 

JsArrayString arr = JavaScriptObject.createArray().cast();
arr.push(str1);
arr.push(str2);
arr.push(str3);

or

static native JsArrayString asJsArray(String str1, String str2, String str3) /*-{
  return [str1, str2, str3];
}-*/;

Obviously, the latter doesn't scale, while being faster.

It really depends what exactly you need to do.


Use JsArrayUtils like this:

JsArray<String> arr = JsArrayUtils.readOnlyJsArray(new String[] { string1, string2 });

Take a look at the javadoc:

com.google.gwt.core.client.JsArrayUtils

Utility class for manipulating JS arrays. These methods are not on other JavaScriptObject subclasses, such as JsArray, because adding new methods might break existing subtypes.


Using generics, could do it like this:

public <T extends JavaScriptObject> JsArray<T> createGenericArray(T... objects) {
    JsArray<T> array = JavaScriptObject.createArray().cast();

    for (T object : objects) {
        array.push(object);
    }

    return array;
}

Obviously, String doesn't extend JavaScriptObject. You'd need to have overloads to account for primitive types. (Or, less safely, you could remove the bounds of T to allow for arbitrary types. You'd need to be much more careful if you were to do so.)

Tags:

Gwt

Gwt2

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