callback

问题 I want to work with promises but I have a callback API in a format like: 1. DOM load or other one time event: window.onload; // set to callback ... window.onload = function() { }; 2. Plain callback: function request(onChangeHandler) { ... } request(function() { // change happened ... }); 3. Node style callback ("nodeback"): function getStuff(dat, callback) { ... } getStuff("dataParam", function(err, data) { ... }) 4. A whole library with node style callbacks: API; API.one(function(err, data)

问题 I am trying to use the csvtojson node module to read content from a csv file so that I can display it in my html view. Below I follow the example provided on the csvtojson page. I am successfully reading and logging the contents of the csv file, but I cannot figure out how to pass the contents to my controller at the right time so that I can display them in my view. Currently, the code under // public api is returned before the csv is finished being parsed. Consequently, result is passed with

问题 Loopback datasource API offers automigrate function with an optional callback. I see in some examples that the callback gets one parameter (err), but no definition of that. What form does the callback parameter have? Are there other possible parameters? How is this with the other functions? 回答1: Callbacks are nothing but the function which you passing as a parameter to the other function Look at this example function printResult(err,result) { if(err) { console.log('something went wrong');

问题 I was playing around with call backs and deferred functions in jQuery and was wondering if anyone could tell me why this works http://jsfiddle.net/austinbv/QVujr/ get_each_total = function(callback) { var requests; requests = []; var url; url = "http://otter.topsy.com/search.js?callback=?&apikey=38A260E9D12A4908B1AF9184B691131&q=justin+bieber&window=d"; return requests.push($.getJSON(url, function(data) { })); return $.when.apply($, requests).then(function() { callback(); }, function() {

问题 I'm trying to read some raw telemetry data via serial. Each message terminates with \r\n and there are 4 kinds of messages. I setup the port like this: if exist('s') fclose(s); delete(s); clear s; end s = serial('/dev/ttyS99'); s.BaudRate = 57600; s.BytesAvailableFcnMode = 'terminator'; s.Terminator = 'CR/LF'; s.DataBits = 8; s.Parity = 'none'; s.StopBits = 1; s.BytesAvailableFcn = @serial_callback; s.OutputEmptyFcn = @serial_callback; fopen(s); For the calback, i wrote a simple function

问题 I am trying to get a document from SAP DMS using SAP.Net Connector 3.0. I need to get the document and display in ASP.Net. I am using "BAPI_DOCUMENT_CHECKOUTVIEW2" for calling the function. But when the invoke method is called, "RFC callback server not available" error is thrown. The code i have used is below. ... sap.RfcRepository repo = prd.Repository; sap.IRfcFunction testBapi = repo.CreateFunction("BAPI_DOCUMENT_CHECKOUTVIEW2"); testBapi.SetValue("DOCUMENTNUMBER", docNumber); testBapi

问题 I am working on a Gtk project in C. From the main.c I call a function1 with an int address as a parameter. In that function1 , I can access that first value, but then at the end (inside) of that function1 , I call another function2 (which is a callback function to a click event) and pass it the address I got from the function1 parameter. But in function2 , the address have changed, definitely can't figure out why ... My project looks like this : [main.c] int main(...) { int a = 50; function1(

问题 I'm taking a picture using my own camera and trying to save the result to the file system (/data/data/package.name/file/captured_photo1.jpeg). When i try it on the emulator (Android 2.2) it seems to work - creates a file with size 8733 bytes and displays it (emulator's default photo). The problem is that when i try it on my GalaxyS (Android 2.2.1) the image on the file system is 0 bytes i found out (from the log) that one of the callbacks i pass to my takePicture method isn't called. and it's

问题 I have the following code, which has been simplified for this question. Basically i have a loop, that, on each iteration, calls the jquery getJSON function, calling out to a API end point to grab some weather data. The problem is that i need to access the index from the loop, when the getJSON request was fired, and am having some troubles with it. I need to know what index the request was for, so i can match it with some data from a database. The code: function buildCities() { for (var i = 0;

问题 I have been searching an answer for this question and I came across the functions timerfd_create and epoll in Linux. In a tutorial it was said that epoll_ctl() has an epoll_data_t union member of the epoll_event structure which can be used to execute a callback function on a timerfd event firing. But I am not sure on how to do it. Can anyone please help. 回答1: You can't put a callback function pointer into epoll_event because it can't fit in any of these slots: typedef union epoll_data { void