If you want to specify a class method as a callback, you need to specify the object it belongs to: array_walk($fieldsArray, array($this, ‘test_print’)); From the manual: A method of an instantiated object is passed as an array containing an object at index 0 and the method name at index 1.
So if I want to pass a list to my callback function through WinApi I use GCHandle // object to IntPtr (before calling WinApi): List<string> list1 = new List<string>(); GCHandle handle1 = GCHandle.Alloc(list1); IntPtr parameter = (IntPtr) handle1; // call WinAPi and pass the parameter here // then free the handle when not needed: handle1.Free(); … Read more
The notion of “returning” values from callbacks doesn’t make sense in the context of an event driven program. Callbacks are called as the result of an event, so there’s nowhere to return a value to. As a general rule of thumb, your callbacks should always call a function, rather than using functools.partial or lambda. Those … Read more
A callback is a piece of code that you pass as an argument to some other code so that it executes it. Since Java doesn’t yet support function pointers, they are implemented as Command objects. Something like public class Test { public static void main(String[] args) throws Exception { new Test().doWork(new Callback() { // implementing … Read more
You should use the submit event on the form, not the click event of the button. Some browsers allow the form to be submitted without using the submit button by just pressing enter when some field in the form has focus. The preventDefault method will stop the submitting of the form, so that you can … Read more
The whitelist is present on both iOS and Android, but not other platforms yet. Under iOS, it goes under the name of “External Hosts,” which is explained here: http://wiki.phonegap.com/w/page/41631150/PhoneGap%20for%20iOS%20FAQ Q. Links to and imported files from external hosts don’t load? A. The latest code has the new white-list feature. If you are referencing external hosts, … Read more
I needed to define this callback: typedef void (*MIDIReadProc) ( const MIDIPacketList *pktlist, void *readProcRefCon, void *srcConnRefCon ); and I wanted to use Objective-C as least as possible. This was my approach: MIDIReadProcCallback.h #import <Foundation/Foundation.h> #import <AudioToolbox/AudioToolbox.h> typedef void (^OnCallback)(const MIDIPacketList *packetList); @interface MIDIReadProcCallback : NSObject + (void (*)(const MIDIPacketList *pktlist, void *readProcRefCon, void *srcConnRefCon))midiReadProc; … Read more
There’s no special syntax for callbacks, just pass the callback function and call it inside your function. function a(message, cb) { console.log(message); // log to the console of recent Browsers cb(); } a(“Hi.”, function() { console.log(“After hi…”); }); Output: Hi. After hi…
For your requirement, I suggest you refer to my following solution, hope it’s clear and helpful: First is the interface: public interface VolleyResponseListener { void onError(String message); void onResponse(Object response); } Then inside your helper class (I name it VolleyUtils class): public static void makeJsonObjectRequest(Context context, String url, final VolleyResponseListener listener) { JsonObjectRequest jsonObjectRequest = … Read more
What you need is a simple queue of onload functions. Also please avoid browser sniffing as it is unstable and not future proof. For full source code see the [Demo] var onload_queue = []; var dom_loaded = false; function loadScriptAsync(src, callback) { var script = document.createElement(‘script’); script.type = “text/javascript”; script.async = true; script.src = src; … Read more