super

I'm writing the constructor of a LoginRequest class which extends a class called JsobObjectRequest (from the Volley framework in Android, but that's completely irrelevant to the question) With this code : public LoginRequest(String username, String password, Response.Listener<JSONObject> responseListener, Response.ErrorListener errorListener) { Boolean hasCredentials=(username!=null && password!=null); int method=hasCredentials? Method.POST:Request.Method.GET; super(method, API_URL_LOGIN, null, responseListener, errorListener); this.username=username; this.password=password; } I get the error:

public abstract class AbstractTool<AT extends AbstractThing> { protected ArrayList<AT> ledger; public AbstractTool() { ledger = new ArrayList<AT>(); } public AT getToolAt(int i) { return ledger.get(i); } // More code Which operates on Ledger ... } public class Tool<AT extends AbstractThing> extends AbstractTool { public Tool() { super(); } } How do I correctly call super to pass the AT generic of Tool to the AbstractTool constructor? It seems no matter what I pick AT to be when I declare Tool (Say, Tool<Thing> ), that I always get back an AbstractThing instead of Thing . This seems to defeat

the idea is to to have multiple widgets on a page and include all js and css files needed form this 'widgets' (it's easy to manage files this way). Duplicated files is not a problem. Every widget's template is included into a page by {%include%} From inside widget's template I'm trying to add content to parent's block: PARENT: {%block js%} {%endblock%} WIDGET {%block js%} {{block.super}} ///my widget spectyfic JS {%end block%} this is giving an error with {{block.super}}: Caught AttributeError while rendering: 'BlockNode' object has no attribute 'context' I'm not sure how else can I extend

This question is derived from super keyword unexpected here The accepted answer says: Because super is only valid inside methods. But in MDN , it seems these two are both methods: let person = { greeting() { return "Hello"; } }; let friend = { // shorter syntax for method? greeting() { return super.greeting() + ", hi!"; } // method? // greeting: function() { // return super.greeting() + ", hi!"; // Throw error: Uncaught SyntaxError: 'super' keyword unexpected here // } }; Object.setPrototypeOf(friend, person); console.log(friend.greeting()); In understanding es6 , Nacholas says: Attempting to

Currently (Android API 17), the only mention of super in the Android Reference on Fragment is casually via some code examples (unlike the Android Reference on Activity , which carefully notes where super is required). SO suggests searching the web as needed, or waiting for a crash, to identify where a call to super is required. I'm asking SO users to share their knowledge on which of the Fragment lifecycle methods require a call to super . Fragment lifecycle methods - require call to super onAttach() onCreate() - presumably yes, as Activity version requires it onCreateView() - seems ok with or

I want that when a child class overrides a method in a parent class, the super.method() is called in that child method. Is there any way to check this at compile time? If not, how would I go about throwing a runtime exception when this happens? There's no way to require this directly. What you can do, however, is something like: public class MySuperclass { public final void myExposedInterface() { //do the things you always want to have happen here overridableInterface(); } protected void overridableInterface() { //superclass implemention does nothing } } public class MySubclass extends