I'm trying to stop postback from happening if a certain condition is met in the XMLHttpRequest's callback function. I've used return false from within the function, but the postback happens anyway. Is there a way to stop it in such a case?
When the callback function is called the postback has already happened so it will be to late to try to stop it.
The callback is called by the XMLHttpRequest once it receives the result back from the server.
Related
I am making a call using Twilio using the following code
$call = $client->account->calls->create ($twilioPhoneNumber,
$customerPhoneNumber, // The number of the phone receiving call
$url,
$options); // The URL Twilio will request when the call is answered
In the options, I have the following parameters:
$options = array('StatusCallback'=>'twilioStatusCallback.php',
'IfMachine'=>'Hangup', 'FallbackUrl'=>'fallBack.php','Timeout'=>'15');
If the call is answered, and the Twilio menu goes through correctly, there is no problem.
But if the call is not answered or busy, Twilio still returns the call status as 'completed' to twilioStatusCallback.php
How can I get a correct busy or no-answer status instead?
Thanks.
Megan from Twilio here.
When you're making calls, the completed event is fired when the call is completed, regardless of the status.
You can create custom actions while tracking call status based upon the transitions between call state.
I am trying to setup some ServiceListeners, in particular two:
zeroConf.addServiceListener("100.1.168.192.in-addr.arpa.", myListener);
zeroConf.addServiceListener("_workstation._tcp.local.", myListener);
Whenever I do this, I get callbacks for myListener on serviceResolved() and serviceAdded() for all services that match "_workstation._tcp.local." However, I get no callbacks for "100.1.168.192.in-addr.arpa." ... despite the fact that jmDns sends out the queries, and a response comes back! I've attached a tcpdump of the request packets that jmdns sends out, and the response that comes back for it. However, the callbacks are not called so I never see the response in my application.
Does anyone know why this might be happening?
http://users.ece.cmu.edu/~gnychis/jmdns_nocallback.pcap
After some debugging of the actual event type that comes in, the event type resolves to "_tcp.in-addr.arpa." Adding this to my service listeners triggers the call back.
My code is for sending Emails to multiple users.User will click on send button,and rpc will be called. Now if user clicks on Cancel button .Ongoing rpc should be cancelled. . Can anyone help ?
I googled a lot, they have introduced the concept of Request Builder. But I am not getting any perfect idea.
Make your async method return a Request instead of void so you can call cancel() on it.
For the same reason, asynchronous methods do not have return types; they generally return void. Should you wish to have more control over the state of a pending request, return Request instead.
— Source: https://developers.google.com/web-toolkit/doc/latest/DevGuideServerCommunication#DevGuideCreatingServices
FYI, you can also use RequestBuilder as the return type, you'll then have to call the send() method by yourself (after possibly customizing the request, e.g. adding headers) to actually make the request to the server.
And of course, if you need to tell the server to abort the processing, you'll have to make another RPC call.
The request is asynch, so the client side can do anything it wants.
All you need to do is add a flag to indicate that the request should be cancelled, and then change the onSuccess method to check the flag and do nothing if it is set.
You should clear the requestCancelled flag each time you make a request - or else after the first request is cancelled, you won't be able to make another one...
e.g.
boolean requestCancelled = false;
void onSuccess(...)
{
if (!requestCancelled) {
// actual response handing code
}
}
If you really want to cancel the request on the server side, it is a lot more complicated. You could do this by sending a second request - one where the fuinctionality is to cancel a request.
To make this work, the "cancel request" has to set a field somewhere the "email request" can read. The "email request" needs to check if the "cancel field" has been set.
// server side Impl
void cancelRequest()
{
// You need to implement this class and ensure it really is a singleton
// and thread safe.
RequestStatusSingleton.setCancelled(true);
}
void serverSideEmailFunc()
{
while(modeEmailAddrs && ! RequestStatusSingleton.getCancelled()) {
// get next address and send email
}
}
Obviously this is a lot of work. Have you considered:
Not having a cancel button on your GUI?
Getting the server to process emails a few at a time (i.e. client sends multiple requests until server tells the client all emails are done).
I totally understand your user. No one wants to wait for 15 seconds.
There is no standard way to "kill" the request, because there is no way to know where your server/datastore is in implementing it. Unless you deal with a process that can be put in a single transaction that can be rolled back, you will have to implement your own logic. For example, if you asked the server to save an entity, you will have to tell the server to save this entity again, but this time without the changes.
Also, think again about your use case. Why a user wants to kill the request? May be he simply wants to go to another place in the app. Then there is no need to kill the request: when the response arrives, check if the user is still in the same place patiently waiting. If not, do not execute onSuccess().
I have a problem getting facebook to call my credits callback script. I've setup a company and the callback url. I used the example script for it. But nonetheless I always get this error when I try to access the payment window using the JS sdk.
var obj = {
method: 'pay',
order_info: order_info,
purchase_type: 'item'
// dev_purchase_params: {'oscif': true}
};
FB.ui(obj, getCashCB);
Error:
There Was a Problem Processing Your Payment
Sorry, but we're having trouble processing your payment. You have not been charged for this transaction. Please try again.
error code from console: 1383046
meaning:
1383046 AppInvalidDecodedResponse The application return value was invalid after json_decoding the return value.
No matter if I'm in sandbox mode, set the callback url to something completely different.
The callback script is never called.
I've searched far and long for anybody else with this problem, but found nothing meaningful. There was something about the server accepting curl requests from facebook but I don't know what that means or how to test for it.
Solved! Whilst looking for the cause I noticed that this error can pop up from a lot of things. But this case is rather specific:
Because the facebook app is still in development, we hid it behind a .htaccess file. So when you visit the site, you login, and the app loads etc. BUT this doesn't work for the credits callback file. Since the request then comes from facebook, it would have to login with user:pass. I tried putting that in the callback URL, but that doesn't seem to work.
So I only need to put the callback file somewhere where you can reach it without .htaccess and Tadaaa it works!
Basically this happens when Facebook doesn't understand the response it gets from calling your payment callback URL. Thew most likely reasons are:
The callback URL is wrong
Facebook gets an error response because the server or some app-level firewall won't let it access the URL (Jon's problem)
Facebook gets an error response because the callback script runs into an exception.
The callback script's response is malformed.
Is there a comprehensive explanation of how the Zend Redirector Action Helper works? I've read the reference guide, but am still not 100% clear. For example:
Apparently the goToSimple() is more like a forward(), than a redirect. Does this mean that it won't send a redirect message back to the browser?
If I want to send a redirect message back to the browser, which Redirector method should I be using?
Is there a way to get the forward() type of behaviour, without re-executing the init() method of Action Helpers?
This problem cropped up when I was implementing an ACL. I have an ACL Action Helper and its init() method adds the role 'current'. When I use the redirector's goToSimple() I get an error saying that the role is already registered. I can use if (!$acl->hasRole('current')) however I think it would be preferable not to be re-executing the helper's init() in the first place.
Not too comprehensive just a few quick notes about the redirector.
The redirector does a little bit more than a regular PHP redirect which you would use with header('Location: www.domain.com/new/location') in your script--following by an exit().
If you look at Zend_Controller_Action_Helper_Redirector it ultimately does exactly the same; if $_exit==true (default) everything leads to redirectAndExit() which calls header() and ends with an exit() call. However it terminates the framework properly, mainly the session if any.
The redirector does not forward internally it sends a default 302 code back unless you have set another code with setCode().
Methods gotoRoute() and gotoSimple() assemble the destination URL for you and call redirectAndExit() but only if $_exit==true. Or you can use their brethren gotoRouteAndExit() and gotoSimpleAndExit() which will exit immediately. The gotoSimple methods pass on to setGotoSimple which uses some methods to assemble the URL for you.
In your case I can only assume that the setGotoSimple method and one of the methods in it call the destination controller and fire up the init() method; however, only for checking but not forwarding.