You can store them in tasks, then await them all:
var catTask = FeedCat();
var houseTask = SellHouse();
var carTask = BuyCar();
await Task.WhenAll(catTask, houseTask, carTask);
Cat cat = await catTask;
House house = await houseTask;
Car car = await carTask;
You may also do:
YourAsyncFunctionName = async (value) => {
/* Code goes here */
}
Use FromResult Method
public async Task<string> GetString()
{
System.Threading.Thread.Sleep(5000);
return await Task.FromResult("Hello");
}
I did try using a Monitor (code below) which appears to work but has a GOTCHA... when you have multiple threads it will give... System.Threading.SynchronizationLockException Object synchronization method was called from an unsynchronized block of code.
using System;
using System.Threading;
using System.Threading.Tasks;
namespace MyNamespace
{
public class ThreadsafeFooModifier :
{
private readonly object _lockObject;
public async Task<FooResponse> ModifyFooAsync()
{
FooResponse result;
Monitor.Enter(_lockObject);
try
{
result = await SomeFunctionToModifyFooAsync();
}
finally
{
Monitor.Exit(_lockObject);
}
return result;
}
}
}
Prior to this I was simply doing this, but it was in an ASP.NET controller so it resulted in a deadlock.
public async Task<FooResponse> ModifyFooAsync()
{
lock(lockObject)
{
return SomeFunctionToModifyFooAsync.Result;
}
}
This is a moment.js flavored module based on the dirty blocking approach suggested by @atlex2. Use this only for testing.
const moment = require('moment');
let sleep = (secondsToSleep = 1) => {
let sleepUntill = moment().add(secondsToSleep, 'seconds');
while(moment().isBefore(sleepUntill)) { /* block the process */ }
}
module.exports = sleep;
This is how I do it with an array Func<>:
var tasks = new Func<Task>[]
{
() => myAsyncWork1(),
() => myAsyncWork2(),
() => myAsyncWork3()
};
await Task.WhenAll(tasks.Select(task => task()).ToArray()); //Async
Task.WaitAll(tasks.Select(task => task()).ToArray()); //Or use WaitAll for Sync
I am not very sure whether it will make any difference in performance of my API.
Bear in mind that the primary benefit of asynchronous code on the server side is scalability. It won't magically make your requests run faster. I cover several "should I use async
" considerations in my article on async
ASP.NET.
I think your use case (calling other APIs) is well-suited for asynchronous code, just bear in mind that "asynchronous" does not mean "faster". The best approach is to first make your UI responsive and asynchronous; this will make your app feel faster even if it's slightly slower.
As far as the code goes, this is not asynchronous:
public Task<BackOfficeResponse<List<Country>>> ReturnAllCountries()
{
var response = _service.Process<List<Country>>(BackOfficeEndpoint.CountryEndpoint, "returnCountries");
return Task.FromResult(response);
}
You'd need a truly asynchronous implementation to get the scalability benefits of async
:
public async Task<BackOfficeResponse<List<Country>>> ReturnAllCountriesAsync()
{
return await _service.ProcessAsync<List<Country>>(BackOfficeEndpoint.CountryEndpoint, "returnCountries");
}
Or (if your logic in this method really is just a pass-through):
public Task<BackOfficeResponse<List<Country>>> ReturnAllCountriesAsync()
{
return _service.ProcessAsync<List<Country>>(BackOfficeEndpoint.CountryEndpoint, "returnCountries");
}
Note that it's easier to work from the "inside out" rather than the "outside in" like this. In other words, don't start with an asynchronous controller action and then force downstream methods to be asynchronous. Instead, identify the naturally asynchronous operations (calling external APIs, database queries, etc), and make those asynchronous at the lowest level first (Service.ProcessAsync
). Then let the async
trickle up, making your controller actions asynchronous as the last step.
And under no circumstances should you use Task.Run
in this scenario.
When you must return specified type:
Task.FromResult<MyClass>(null);
Is it good to use async action everywhere in ASP.NET MVC?
It's good to do so wherever you can use an async method especially when you have performance issues at the worker process level which happens for massive data and calculation operations. Otherwise, no need because unit testing will need casting.
Regarding awaitable methods: shall I use async/await keywords when I want to query a database (via EF/NHibernate/other ORM)?
Yes, it's better to use async for any DB operation as could as possible to avoid performance issues at the level of worker processes. Note that EF has created many async alternatives for most operations, such as:
.ToListAsync()
.FirstOrDefaultAsync()
.SaveChangesAsync()
.FindAsync()
How many times can I use await keywords to query the database asynchronously in one single action method?
The sky is the limit
I was just wondering why we can't call
await
from within a constructor directly.
I believe the short answer is simply: Because the .Net team has not programmed this feature.
I believe with the right syntax this could be implemented and shouldn't be too confusing or error prone. I think Stephen Cleary's blog post and several other answers here have implicitly pointed out that there is no fundamental reason against it, and more than that - solved that lack with workarounds. The existence of these relatively simple workarounds is probably one of the reasons why this feature has not (yet) been implemented.
If you didn't want to use async/await inside your method, but still "decorate" it so as to be able to use the await keyword from outside, TaskCompletionSource.cs:
public static Task<T> RunAsync<T>(Func<T> function)
{
if (function == null) throw new ArgumentNullException(“function”);
var tcs = new TaskCompletionSource<T>();
ThreadPool.QueueUserWorkItem(_ =>
{
try
{
T result = function();
tcs.SetResult(result);
}
catch(Exception exc) { tcs.SetException(exc); }
});
return tcs.Task;
}
To support such a paradigm with Tasks, we need a way to retain the Task façade and the ability to refer to an arbitrary asynchronous operation as a Task, but to control the lifetime of that Task according to the rules of the underlying infrastructure that’s providing the asynchrony, and to do so in a manner that doesn’t cost significantly. This is the purpose of TaskCompletionSource.
I saw it's also used in the .NET source, e.g. WebClient.cs:
[HostProtection(ExternalThreading = true)]
[ComVisible(false)]
public Task<string> UploadStringTaskAsync(Uri address, string method, string data)
{
// Create the task to be returned
var tcs = new TaskCompletionSource<string>(address);
// Setup the callback event handler
UploadStringCompletedEventHandler handler = null;
handler = (sender, e) => HandleCompletion(tcs, e, (args) => args.Result, handler, (webClient, completion) => webClient.UploadStringCompleted -= completion);
this.UploadStringCompleted += handler;
// Start the async operation.
try { this.UploadStringAsync(address, method, data, tcs); }
catch
{
this.UploadStringCompleted -= handler;
throw;
}
// Return the task that represents the async operation
return tcs.Task;
}
Finally, I also found the following useful:
I get asked this question all the time. The implication is that there must be some thread somewhere that’s blocking on the I/O call to the external resource. So, asynchronous code frees up the request thread, but only at the expense of another thread elsewhere in the system, right? No, not at all.
To understand why asynchronous requests scale, I’ll trace a (simplified) example of an asynchronous I/O call. Let’s say a request needs to write to a file. The request thread calls the asynchronous write method. WriteAsync is implemented by the Base Class Library (BCL), and uses completion ports for its asynchronous I/O. So, the WriteAsync call is passed down to the OS as an asynchronous file write. The OS then communicates with the driver stack, passing along the data to write in an I/O request packet (IRP).
This is where things get interesting: If a device driver can’t handle an IRP immediately, it must handle it asynchronously. So, the driver tells the disk to start writing and returns a “pending” response to the OS. The OS passes that “pending” response to the BCL, and the BCL returns an incomplete task to the request-handling code. The request-handling code awaits the task, which returns an incomplete task from that method and so on. Finally, the request-handling code ends up returning an incomplete task to ASP.NET, and the request thread is freed to return to the thread pool.
Introduction to Async/Await on ASP.NET
If the target is to improve scalability (rather than responsiveness), it all relies on the existence of an external I/O that provides the opportunity to do that.
One of the most important thing to remember when decorating a method with async is that at least there is one await operator inside the method. In your example, I would translate it as shown below using TaskCompletionSource.
private Task<int> DoWorkAsync()
{
//create a task completion source
//the type of the result value must be the same
//as the type in the returning Task
TaskCompletionSource<int> tcs = new TaskCompletionSource<int>();
Task.Run(() =>
{
int result = 1 + 2;
//set the result to TaskCompletionSource
tcs.SetResult(result);
});
//return the Task
return tcs.Task;
}
private async void DoWork()
{
int result = await DoWorkAsync();
}
Adding the async keyword is just syntactic sugar to simplify the creation of a state machine. In essence, the compiler takes your code;
public async Task MethodName()
{
return null;
}
And turns it into;
public Task MethodName()
{
return Task.FromResult<object>(null);
}
If your code has any await
keywords, the compiler must take your method and turn it into a class to represent the state machine required to execute it. At each await
keyword, the state of variables and the stack will be preserved in the fields of the class, the class will add itself as a completion hook to the task you are waiting on, then return.
When that task completes, your task will be executed again. So some extra code is added to the top of the method to restore the state of variables and jump into the next slab of your code.
See What does async & await generate? for a gory example.
This process has a lot in common with the way the compiler handles iterator methods with yield statements.
I had the same problem. The answers got me on the right track. So the problem is that functions marked with async don't return a task of the function itself as expected (but another continuation task of the function).
So its the "await"and "async" keywords that screws thing up. The simplest solution then is simply to remove them. Then it works as expected. As in:
static void Main(string[] args)
{
Console.WriteLine("Foo called");
var result = Foo(5);
while (result.Status != TaskStatus.RanToCompletion)
{
Console.WriteLine("Thread ID: {0}, Status: {1}", Thread.CurrentThread.ManagedThreadId, result.Status);
Task.Delay(100).Wait();
}
Console.WriteLine("Result: {0}", result.Result);
Console.WriteLine("Finished.");
Console.ReadKey(true);
}
private static Task<string> Foo(int seconds)
{
return Task.Run(() =>
{
for (int i = 0; i < seconds; i++)
{
Console.WriteLine("Thread ID: {0}, second {1}.", Thread.CurrentThread.ManagedThreadId, i);
Task.Delay(TimeSpan.FromSeconds(1)).Wait();
}
return "Foo Completed.";
});
}
Which outputs:
Foo called
Thread ID: 1, Status: WaitingToRun
Thread ID: 3, second 0.
Thread ID: 1, Status: Running
Thread ID: 1, Status: Running
Thread ID: 1, Status: Running
Thread ID: 1, Status: Running
Thread ID: 1, Status: Running
Thread ID: 1, Status: Running
Thread ID: 1, Status: Running
Thread ID: 1, Status: Running
Thread ID: 1, Status: Running
Thread ID: 3, second 1.
Thread ID: 1, Status: Running
Thread ID: 1, Status: Running
Thread ID: 1, Status: Running
Thread ID: 1, Status: Running
Thread ID: 1, Status: Running
Thread ID: 1, Status: Running
Thread ID: 1, Status: Running
Thread ID: 1, Status: Running
Thread ID: 1, Status: Running
Thread ID: 3, second 2.
Thread ID: 1, Status: Running
Thread ID: 1, Status: Running
Thread ID: 1, Status: Running
Thread ID: 1, Status: Running
Thread ID: 1, Status: Running
Thread ID: 1, Status: Running
Thread ID: 1, Status: Running
Thread ID: 1, Status: Running
Thread ID: 1, Status: Running
Thread ID: 3, second 3.
Thread ID: 1, Status: Running
Thread ID: 1, Status: Running
Thread ID: 1, Status: Running
Thread ID: 1, Status: Running
Thread ID: 1, Status: Running
Thread ID: 1, Status: Running
Thread ID: 1, Status: Running
Thread ID: 1, Status: Running
Thread ID: 1, Status: Running
Thread ID: 3, second 4.
Thread ID: 1, Status: Running
Thread ID: 1, Status: Running
Thread ID: 1, Status: Running
Thread ID: 1, Status: Running
Thread ID: 1, Status: Running
Thread ID: 1, Status: Running
Thread ID: 1, Status: Running
Thread ID: 1, Status: Running
Thread ID: 1, Status: Running
Thread ID: 1, Status: Running
Result: Foo Completed.
Finished.
is using them equal to spawning background threads to perform long duration logic?
This article MDSN:Asynchronous Programming with async and await (C#) explains it explicitly:
The async and await keywords don't cause additional threads to be created. Async methods don't require multithreading because an async method doesn't run on its own thread. The method runs on the current synchronization context and uses time on the thread only when the method is active.
You are calling DoDownloadAsync() but you don't wait it. So your program going to the next line. But there is another problem, Async methods should return Task
or Task<T>
, if you return nothing and you want your method will be run asyncronously you should define your method like this:
private static async Task DoDownloadAsync() { WebClient w = new WebClient(); string txt = await w.DownloadStringTaskAsync("http://www.google.com/"); Debug.WriteLine(txt); }
And in Main method you can't await for DoDownloadAsync
, because you can't use await keyword in non-async function, and you can't make Main
async. So consider this:
var result = DoDownloadAsync(); Debug.WriteLine("DoDownload done"); result.Wait();
You can use the simple and lightweight module https://github.com/nacholibre/nwc-l it supports both async and sync methods.
Note: this module was created by me.
Some important facts were not given in other answers:
"async await" is more complex at CIL level and thus costs memory and CPU time.
Any task can be canceled if the waiting time is unacceptable.
In the case "async await" we do not have a handler for such a task to cancel it or monitoring it.
Using Task is more flexible then "async await".
Any sync functionality can by wrapped by async.
public async Task<ActionResult> DoAsync(long id)
{
return await Task.Run(() => { return DoSync(id); } );
}
"async await" generate many problems. We do not now is await statement will be reached without runtime and context debugging. If first await not reached everything is blocked. Some times even await seems to be reached still everything is blocked:
https://github.com/dotnet/runtime/issues/36063
I do not see why I'm must live with the code duplication for sync and async method or using hacks.
Conclusion: Create Task manually and control them is much better. Handler to Task give more control. We can monitor Tasks and manage them:
https://github.com/lsmolinski/MonitoredQueueBackgroundWorkItem
Sorry for my english.
Maybe I'm too naive but, couldn't you create an event that is raised when GetStringData() is called and attach an EventHandler that calls and awaits the async method?
Something like:
public event EventHandler FireAsync;
public string GetStringData()
{
FireAsync?.Invoke(this, EventArgs.Empty);
return "hello world";
}
public async void HandleFireAsync(object sender, EventArgs e)
{
await MyAsyncMethod();
}
And somewhere in the code attach and detach from the event:
FireAsync += HandleFireAsync;
(...)
FireAsync -= HandleFireAsync;
Not sure if this might be anti-pattern somehow (if it is please let me know), but it catches the Exceptions and returns quickly from GetStringData().
Here is a workaround using a flag:
//outside your event or method, but inside your class
private bool IsExecuted = false;
private async Task MethodA()
{
//Do Stuff Here
IsExecuted = true;
}
.
.
.
//Inside your event or method
{
await MethodA();
while (!isExecuted) Thread.Sleep(200); // <-------
await MethodB();
}
Depending on what you're trying to do, you can either block with GetIdList().Result ( generally a bad idea, but it's hard to tell the context) or use a test framework that supports async test methods and have the test method do var results = await GetIdList();
Another option is to use Promise.all to wait for an array of promises to resolve and then act on those.
Code below shows how to wait for all the promises to resolve and then deal with the results once they are all ready (as that seemed to be the objective of the question); Also for illustrative purposes, it shows output during execution (end finishes before middle).
function append_output(suffix, value) {
$("#output_"+suffix).append(value)
}
function kickOff() {
let start = new Promise((resolve, reject) => {
append_output("now", "start")
resolve("start")
})
let middle = new Promise((resolve, reject) => {
setTimeout(() => {
append_output("now", " middle")
resolve(" middle")
}, 1000)
})
let end = new Promise((resolve, reject) => {
append_output("now", " end")
resolve(" end")
})
Promise.all([start, middle, end]).then(results => {
results.forEach(
result => append_output("later", result))
})
}
kickOff()
_x000D_
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
Updated during execution: <div id="output_now"></div>
Updated after all have completed: <div id="output_later"></div>
_x000D_
Better solution is to introduce another interface for async operations. New interface must inherit from original interface.
Example:
interface IIO
{
void DoOperation();
}
interface IIOAsync : IIO
{
Task DoOperationAsync();
}
class ClsAsync : IIOAsync
{
public void DoOperation()
{
DoOperationAsync().GetAwaiter().GetResult();
}
public async Task DoOperationAsync()
{
//just an async code demo
await Task.Delay(1000);
}
}
class Program
{
static void Main(string[] args)
{
IIOAsync asAsync = new ClsAsync();
IIO asSync = asAsync;
Console.WriteLine(DateTime.Now.Second);
asAsync.DoOperation();
Console.WriteLine("After call to sync func using Async iface: {0}",
DateTime.Now.Second);
asAsync.DoOperationAsync().GetAwaiter().GetResult();
Console.WriteLine("After call to async func using Async iface: {0}",
DateTime.Now.Second);
asSync.DoOperation();
Console.WriteLine("After call to sync func using Sync iface: {0}",
DateTime.Now.Second);
Console.ReadKey(true);
}
}
P.S. Redesign your async operations so they return Task instead of void, unless you really must return void.
If you have an async method called " RefreshList " then, you can call that async method from a non-async method like below.
Task.Run(async () => { await RefreshList(); });
You are misusing the API.
Here's the situation: in ASP.NET, only one thread can handle a request at a time. You can do some parallel processing if necessary (borrowing additional threads from the thread pool), but only one thread would have the request context (the additional threads do not have the request context).
This is managed by the ASP.NET SynchronizationContext
.
By default, when you await
a Task
, the method resumes on a captured SynchronizationContext
(or a captured TaskScheduler
, if there is no SynchronizationContext
). Normally, this is just what you want: an asynchronous controller action will await
something, and when it resumes, it resumes with the request context.
So, here's why test5
fails:
Test5Controller.Get
executes AsyncAwait_GetSomeDataAsync
(within the ASP.NET request context).AsyncAwait_GetSomeDataAsync
executes HttpClient.GetAsync
(within the ASP.NET request context).HttpClient.GetAsync
returns an uncompleted Task
.AsyncAwait_GetSomeDataAsync
awaits the Task
; since it is not complete, AsyncAwait_GetSomeDataAsync
returns an uncompleted Task
.Test5Controller.Get
blocks the current thread until that Task
completes.Task
returned by HttpClient.GetAsync
is completed.AsyncAwait_GetSomeDataAsync
attempts to resume within the ASP.NET request context. However, there is already a thread in that context: the thread blocked in Test5Controller.Get
.Here's why the other ones work:
test1
, test2
, and test3
): Continuations_GetSomeDataAsync
schedules the continuation to the thread pool, outside the ASP.NET request context. This allows the Task
returned by Continuations_GetSomeDataAsync
to complete without having to re-enter the request context.test4
and test6
): Since the Task
is awaited, the ASP.NET request thread is not blocked. This allows AsyncAwait_GetSomeDataAsync
to use the ASP.NET request context when it is ready to continue.And here's the best practices:
async
methods, use ConfigureAwait(false)
whenever possible. In your case, this would change AsyncAwait_GetSomeDataAsync
to be var result = await httpClient.GetAsync("http://stackoverflow.com", HttpCompletionOption.ResponseHeadersRead).ConfigureAwait(false);
Task
s; it's async
all the way down. In other words, use await
instead of GetResult
(Task.Result
and Task.Wait
should also be replaced with await
).That way, you get both benefits: the continuation (the remainder of the AsyncAwait_GetSomeDataAsync
method) is run on a basic thread pool thread that doesn't have to enter the ASP.NET request context; and the controller itself is async
(which doesn't block a request thread).
More information:
async
/await
intro post, which includes a brief description of how Task
awaiters use SynchronizationContext
.SynchronizationContext
restricts the request context to just one thread at a time.Update 2012-07-13: Incorporated this answer into a blog post.
You can create an async init() {... return this;}
method, then instead do new MyClass().init()
whenever you'd normally just say new MyClass()
.
This is not clean because it relies on everyone who uses your code, and yourself, to always instantiate the object like so. However if you're only using this object in a particular place or two in your code, it could maybe be fine.
A significant problem though occurs because ES has no type system, so if you forget to call it, you've just returned undefined
because the constructor returns nothing. Oops. Much better would be to do something like:
The best thing to do would be:
class AsyncOnlyObject {
constructor() {
}
async init() {
this.someField = await this.calculateStuff();
}
async calculateStuff() {
return 5;
}
}
async function newAsync_AsyncOnlyObject() {
return await new AsyncOnlyObject().init();
}
newAsync_AsyncOnlyObject().then(console.log);
// output: AsyncOnlyObject {someField: 5}
However then you might accidentally do new AsyncOnlyObject, you should probably just create factory function that uses Object.create(AsyncOnlyObject.prototype)
directly:
async function newAsync_AsyncOnlyObject() {
return await Object.create(AsyncOnlyObject.prototype).init();
}
newAsync_AsyncOnlyObject().then(console.log);
// output: AsyncOnlyObject {someField: 5}
However say you want to use this pattern on many objects... you could abstract this as a decorator or something you (verbosely, ugh) call after defining like postProcess_makeAsyncInit(AsyncOnlyObject)
, but here I'm going to use extends
because it sort of fits into subclass semantics (subclasses are parent class + extra, in that they should obey the design contract of the parent class, and may do additional things; an async subclass would be strange if the parent wasn't also async, because it could not be initialized the same way):
class AsyncObject {
constructor() {
throw new Error('classes descended from AsyncObject must be initialized as (await) TheClassName.anew(), rather than new TheClassName()');
}
static async anew(...args) {
var R = Object.create(this.prototype);
R.init(...args);
return R;
}
}
class MyObject extends AsyncObject {
async init(x, y=5) {
this.x = x;
this.y = y;
// bonus: we need not return 'this'
}
}
MyObject.anew('x').then(console.log);
// output: MyObject {x: "x", y: 5}
(do not use in production: I have not thought through complicated scenarios such as whether this is the proper way to write a wrapper for keyword arguments.)
Generally, using Promise.all()
runs requests "async" in parallel. Using await
can run in parallel OR be "sync" blocking.
test1 and test2 functions below show how await
can run async or sync.
test3 shows Promise.all()
that is async.
jsfiddle with timed results - open browser console to see test results
Sync behavior. Does NOT run in parallel, takes ~1800ms:
const test1 = async () => {
const delay1 = await Promise.delay(600); //runs 1st
const delay2 = await Promise.delay(600); //waits 600 for delay1 to run
const delay3 = await Promise.delay(600); //waits 600 more for delay2 to run
};
Async behavior. Runs in paralel, takes ~600ms:
const test2 = async () => {
const delay1 = Promise.delay(600);
const delay2 = Promise.delay(600);
const delay3 = Promise.delay(600);
const data1 = await delay1;
const data2 = await delay2;
const data3 = await delay3; //runs all delays simultaneously
}
Async behavior. Runs in parallel, takes ~600ms:
const test3 = async () => {
await Promise.all([
Promise.delay(600),
Promise.delay(600),
Promise.delay(600)]); //runs all delays simultaneously
};
TLDR; If you are using Promise.all()
it will also "fast-fail" - stop running at the time of the first failure of any of the included functions.
Here is the simplest way to do this
static void Main(string[] args)
{
Task t = MainAsync(args);
t.Wait();
}
static async Task MainAsync(string[] args)
{
await ...
}
To mark a lambda async, simply prepend async
before its argument list:
// Add a command to delete the current Group
contextMenu.Commands.Add(new UICommand("Delete this Group", async (contextMenuCmd) =>
{
SQLiteUtils slu = new SQLiteUtils();
await slu.DeleteGroupAsync(groupName);
}));
The biggest draw back I've found with using ConfigureAwait(false) is that the thread culture is reverted to the system default. If you've configured a culture e.g ...
<system.web>
<globalization culture="en-AU" uiCulture="en-AU" />
...
and you're hosting on a server whose culture is set to en-US, then you will find before ConfigureAwait(false) is called CultureInfo.CurrentCulture will return en-AU and after you will get en-US. i.e.
// CultureInfo.CurrentCulture ~ {en-AU}
await xxxx.ConfigureAwait(false);
// CultureInfo.CurrentCulture ~ {en-US}
If your application is doing anything which requires culture specific formatting of data, then you'll need to be mindful of this when using ConfigureAwait(false).
You can only use await
in an async
method, and Main
cannot be async
.
You'll have to use your own async
-compatible context, call Wait
on the returned Task
in the Main
method, or just ignore the returned Task
and just block on the call to Read
. Note that Wait
will wrap any exceptions in an AggregateException
.
If you want a good intro, see my async
/await
intro post.
Like @Bergi's response, but with one difference.
Promise.all
rejects all promises if one gets rejected.
So, use a recursion.
const readFilesQueue = async (files, index = 0) {
const contents = await fs.readFile(files[index], 'utf8')
console.log(contents)
return files.length <= index
? readFilesQueue(files, ++index)
: files
}
const printFiles async = () => {
const files = await getFilePaths();
const printContents = await readFilesQueue(files)
return printContents
}
printFiles()
PS
readFilesQueue
is outside of printFiles
cause the side effect* introduced by console.log
, it's better to mock, test, and or spy so, it's not cool to have a function that returns the content(sidenote).
Therefore, the code can simply be designed by that: three separated functions that are "pure"** and introduce no side effects, process the entire list and can easily be modified to handle failed cases.
const files = await getFilesPath()
const printFile = async (file) => {
const content = await fs.readFile(file, 'utf8')
console.log(content)
}
const readFiles = async = (files, index = 0) => {
await printFile(files[index])
return files.lengh <= index
? readFiles(files, ++index)
: files
}
readFiles(files)
Future edit/current state
Node supports top-level await (this doesn't have a plugin yet, won't have and can be enabled via harmony flags), it's cool but doesn't solve one problem (strategically I work only on LTS versions). How to get the files?
Using composition. Given the code, causes to me a sensation that this is inside a module, so, should have a function to do it. If not, you should use an IIFE to wrap the role code into an async function creating simple module that's do all for you, or you can go with the right way, there is, composition.
// more complex version with IIFE to a single module
(async (files) => readFiles(await files())(getFilesPath)
Note that the name of variable changes due to semantics. You pass a functor (a function that can be invoked by another function) and recieves a pointer on memory that contains the initial block of logic of the application.
But, if's not a module and you need to export the logic?
Wrap the functions in a async function.
export const readFilesQueue = async () => {
// ... to code goes here
}
Or change the names of variables, whatever...
*
by side effect menans any colacteral effect of application that can change the statate/behaviour or introuce bugs in the application, like IO.
**
by "pure", it's in apostrophe since the functions it's not pure and the code can be converged to a pure version, when there's no console output, only data manipulations.
Aside this, to be pure, you'll need to work with monads that handles the side effect, that are error prone, and treats that error separately of the application.
I can't seem to wrap my head around why this does not work.
Because main
returns a promise; all async
functions do.
At the top level, you must either:
Use a top-level async
function that never rejects (unless you want "unhandled rejection" errors), or
Use then
and catch
, or
(Coming soon!) Use top-level await
, a proposal that has reached Stage 3 in the process that allows top-level use of await
in a module.
async
function that never rejects(async () => {
try {
var text = await main();
console.log(text);
} catch (e) {
// Deal with the fact the chain failed
}
})();
Notice the catch
; you must handle promise rejections / async exceptions, since nothing else is going to; you have no caller to pass them on to. If you prefer, you could do that on the result of calling it via the catch
function (rather than try
/catch
syntax):
(async () => {
var text = await main();
console.log(text);
})().catch(e => {
// Deal with the fact the chain failed
});
...which is a bit more concise (I like it for that reason).
Or, of course, don't handle errors and just allow the "unhandled rejection" error.
then
and catch
main()
.then(text => {
console.log(text);
})
.catch(err => {
// Deal with the fact the chain failed
});
The catch
handler will be called if errors occur in the chain or in your then
handler. (Be sure your catch
handler doesn't throw errors, as nothing is registered to handle them.)
Or both arguments to then
:
main().then(
text => {
console.log(text);
},
err => {
// Deal with the fact the chain failed
}
);
Again notice we're registering a rejection handler. But in this form, be sure that neither of your then
callbacks doesn't throw any errors, nothing is registered to handle them.
await
in a moduleYou can't use await
at the top level of a non-module script, but the top-level await
proposal (Stage 3) allows you to use it at the top level of a module. It's similar to using a top-level async
function wrapper (#1 above) in that you don't want your top-level code to reject (throw an error) because that will result in an unhandled rejection error. So unless you want to have that unhandled rejection when things go wrong, as with #1, you'd want to wrap your code in an error handler:
// In a module, once the top-level `await` proposal lands
try {
var text = await main();
console.log(text);
} catch (e) {
// Deal with the fact the chain failed
}
Note that if you do this, any module that imports from your module will wait until the promise you're await
ing settles; when a module using top-level await
is evaluated, it basically returns a promise to the module loader (like an async
function does), which waits until that promise is settled before evaluating the bodies of any modules that depend on it.
A cleaner alternative would be the following:
Due to the fact that every async function is technically a promise
You can add catches to functions when calling them with await
async function a(){
let error;
// log the error on the parent
await b().catch((err)=>console.log('b.failed'))
// change an error variable
await c().catch((err)=>{error=true; console.log(err)})
// return whatever you want
return error ? d() : null;
}
a().catch(()=>console.log('main program failed'))
No need for try catch, as all promises errors are handled, and you have no code errors, you can omit that in the parent!!
Lets say you are working with mongodb, if there is an error you might prefer to handle it in the function calling it than making wrappers, or using try catches.
Here is what I did
private void myEvent_Handler(object sender, SomeEvent e)
{
// I dont know how many times this event will fire
Task t = new Task(() =>
{
if (something == true)
{
DoSomething(e);
}
});
t.RunSynchronously();
}
working great and not blocking UI thread
I would like to add that there is a Parallel class with ForEach function built in that can be used for this purpose.
Works for me:
List<Item> list = Task.Run(() => manager.GetList()).Result;
in this way it is not necessary to mark the method with async in the call.
Brian Lagunas has shown a solution that I really like. More info his youtube video
Solution:
Add a TaskExtensions method
public static class TaskExtensions
{
public static async void Await(this Task task, Action completedCallback = null ,Action<Exception> errorCallBack = null )
{
try
{
await task;
completedCallback?.Invoke();
}
catch (Exception e)
{
errorCallBack?.Invoke(e);
}
}
}
Usage:
public class MyClass
{
public MyClass()
{
DoSomething().Await();
// DoSomething().Await(Completed, HandleError);
}
async Task DoSomething()
{
await Task.Delay(3000);
//Some works here
//throw new Exception("Thrown in task");
}
private void Completed()
{
//some thing;
}
private void HandleError(Exception ex)
{
//handle error
}
}
Since the API you're calling is async, the Parallel.ForEach
version doesn't make much sense. You shouldnt use .Wait
in the WaitAll
version since that would lose the parallelism Another alternative if the caller is async is using Task.WhenAll
after doing Select
and ToArray
to generate the array of tasks. A second alternative is using Rx 2.0
I had a task on BE side to find all entities from a repo, and to add a new property url and to return to controller layer. This is how I achieved it (thanks to Ajedi32's response):
async findAll(): Promise<ImageResponse[]> {
const images = await this.imageRepository.find(); // This is an array of type Image (DB entity)
const host = this.request.get('host');
const mappedImages = await Promise.all(images.map(image => ({...image, url: `http://${host}/images/${image.id}`}))); // This is an array of type Object
return plainToClass(ImageResponse, mappedImages); // Result is an array of type ImageResponse
}
Note: Image (entity) doesn't have property url, but ImageResponse - has
Task.WaitAll
blocks the current thread until everything has completed.
Task.WhenAll
returns a task which represents the action of waiting until everything has completed.
That means that from an async method, you can use:
await Task.WhenAll(tasks);
... which means your method will continue when everything's completed, but you won't tie up a thread to just hang around until that time.
Made a util inspired from Dave's answer
Basically passed in a done
callback to call when the operation is finished.
// Function to timeout if a request is taking too long
const setAsyncTimeout = (cb, timeout = 0) => new Promise((resolve, reject) => {
cb(resolve);
setTimeout(() => reject('Request is taking too long to response'), timeout);
});
This is how I use it:
try {
await setAsyncTimeout(async done => {
const requestOne = await someService.post(configs);
const requestTwo = await someService.get(configs);
const requestThree = await someService.post(configs);
done();
}, 5000); // 5 seconds max for this set of operations
}
catch (err) {
console.error('[Timeout] Unable to complete the operation.', err);
}
Long story short,
IQueryable
is designed to postpone RUN process and firstly build the expression in conjunction with other IQueryable
expressions, and then interprets and runs the expression as a whole.
But ToList()
method (or a few sort of methods like that), are ment to run the expression instantly "as is".
Your first method (GetAllUrlsAsync
), will run imediately, because it is IQueryable
followed by ToListAsync()
method. hence it runs instantly (asynchronous), and returns a bunch of IEnumerable
s.
Meanwhile your second method (GetAllUrls
), won't get run. Instead, it returns an expression and CALLER of this method is responsible to run the expression.
I found this code at Microsoft.AspNet.Identity.Core component, and it works.
private static readonly TaskFactory _myTaskFactory = new
TaskFactory(CancellationToken.None, TaskCreationOptions.None,
TaskContinuationOptions.None, TaskScheduler.Default);
// Microsoft.AspNet.Identity.AsyncHelper
public static TResult RunSync<TResult>(Func<Task<TResult>> func)
{
CultureInfo cultureUi = CultureInfo.CurrentUICulture;
CultureInfo culture = CultureInfo.CurrentCulture;
return AsyncHelper._myTaskFactory.StartNew<Task<TResult>>(delegate
{
Thread.CurrentThread.CurrentCulture = culture;
Thread.CurrentThread.CurrentUICulture = cultureUi;
return func();
}).Unwrap<TResult>().GetAwaiter().GetResult();
}
If you are just experimenting you can use babel-node
command line tool to try out the new JavaScript features
Install babel-cli
into your project
$ npm install --save-dev babel-cli
Install the presets
$ npm install --save-dev babel-preset-es2015 babel-preset-es2017
Setup your babel presets
Create .babelrc
in the project root folder with the following contents:
{ "presets": ["es2015","es2017"] }
Run your script with babel-node
$ babel-node helloz.js
This is only for development and testing but that seems to be what you are doing. In the end you'll want to set up webpack (or something similar) to transpile all your code for production
If you want to run the code somewhere else, webpack can help and here is the simplest configuration I could work out:
As of Node.js 14.3.0 the top-level await is supported.
Required flag: --experimental-top-level-await
.
Further details: https://v8.dev/features/top-level-await
Its also important to note that you will lose the chronological stack trace of the exception if you you have a void return type on an async method. I would recommend returning Task as follows. Going to make debugging a whole lot easier.
public async Task DoFoo()
{
try
{
return await Foo();
}
catch (ProtocolException ex)
{
/* Exception with chronological stack trace */
}
}
If you just want simple parallelism, you can do this:
var bag = new ConcurrentBag<object>();
var tasks = myCollection.Select(async item =>
{
// some pre stuff
var response = await GetData(item);
bag.Add(response);
// some post stuff
});
await Task.WhenAll(tasks);
var count = bag.Count;
If you need something more complex, check out Stephen Toub's ForEachAsync
post.
After introducing a bunch of helper methods, you will be able run parallel queries with this simple syntax:
const int DegreeOfParallelism = 10;
IEnumerable<double> result = await Enumerable.Range(0, 1000000)
.Split(DegreeOfParallelism)
.SelectManyAsync(async i => await CalculateAsync(i).ConfigureAwait(false))
.ConfigureAwait(false);
What happens here is: we split source collection into 10 chunks (.Split(DegreeOfParallelism)
), then run 10 tasks each processing its items one by one (.SelectManyAsync(...)
) and merge those back into a single list.
Worth mentioning there is a simpler approach:
double[] result2 = await Enumerable.Range(0, 1000000)
.Select(async i => await CalculateAsync(i).ConfigureAwait(false))
.WhenAll()
.ConfigureAwait(false);
But it needs a precaution: if you have a source collection that is too big, it will schedule a Task
for every item right away, which may cause significant performance hits.
Extension methods used in examples above look as follows:
public static class CollectionExtensions
{
/// <summary>
/// Splits collection into number of collections of nearly equal size.
/// </summary>
public static IEnumerable<List<T>> Split<T>(this IEnumerable<T> src, int slicesCount)
{
if (slicesCount <= 0) throw new ArgumentOutOfRangeException(nameof(slicesCount));
List<T> source = src.ToList();
var sourceIndex = 0;
for (var targetIndex = 0; targetIndex < slicesCount; targetIndex++)
{
var list = new List<T>();
int itemsLeft = source.Count - targetIndex;
while (slicesCount * list.Count < itemsLeft)
{
list.Add(source[sourceIndex++]);
}
yield return list;
}
}
/// <summary>
/// Takes collection of collections, projects those in parallel and merges results.
/// </summary>
public static async Task<IEnumerable<TResult>> SelectManyAsync<T, TResult>(
this IEnumerable<IEnumerable<T>> source,
Func<T, Task<TResult>> func)
{
List<TResult>[] slices = await source
.Select(async slice => await slice.SelectListAsync(func).ConfigureAwait(false))
.WhenAll()
.ConfigureAwait(false);
return slices.SelectMany(s => s);
}
/// <summary>Runs selector and awaits results.</summary>
public static async Task<List<TResult>> SelectListAsync<TSource, TResult>(this IEnumerable<TSource> source, Func<TSource, Task<TResult>> selector)
{
List<TResult> result = new List<TResult>();
foreach (TSource source1 in source)
{
TResult result1 = await selector(source1).ConfigureAwait(false);
result.Add(result1);
}
return result;
}
/// <summary>Wraps tasks with Task.WhenAll.</summary>
public static Task<TResult[]> WhenAll<TResult>(this IEnumerable<Task<TResult>> source)
{
return Task.WhenAll<TResult>(source);
}
}
I had the same problem as I like using the Try-method-pattern which basically seems to be incompatible to the async-await-paradigm...
Important to me is that I can call the Try-method within a single if-clause and do not have to pre-define the out-variables before, but can do it in-line like in the following example:
if (TryReceive(out string msg))
{
// use msg
}
So I came up with the following solution:
Define a helper struct:
public struct AsyncOut<T, OUT>
{
private readonly T returnValue;
private readonly OUT result;
public AsyncOut(T returnValue, OUT result)
{
this.returnValue = returnValue;
this.result = result;
}
public T Out(out OUT result)
{
result = this.result;
return returnValue;
}
public T ReturnValue => returnValue;
public static implicit operator AsyncOut<T, OUT>((T returnValue ,OUT result) tuple) =>
new AsyncOut<T, OUT>(tuple.returnValue, tuple.result);
}
Define async Try-method like this:
public async Task<AsyncOut<bool, string>> TryReceiveAsync()
{
string message;
bool success;
// ...
return (success, message);
}
Call the async Try-method like this:
if ((await TryReceiveAsync()).Out(out string msg))
{
// use msg
}
For multiple out parameters you can define additional structs (e.g. AsyncOut<T,OUT1, OUT2>) or you can return a tuple.
I checked the source code of TaskOfResult.cs
(Source code of TaskOfResult.cs):
If Task
is not completed, Task.Result
will call Task.Wait()
method in getter
.
public TResult Result
{
get
{
// If the result has not been calculated yet, wait for it.
if (!IsCompleted)
{
// We call NOCTD for two reasons:
// 1. If the task runs on another thread, then we definitely need to notify that thread-slipping is required.
// 2. If the task runs inline but takes some time to complete, it will suffer ThreadAbort with possible state corruption.
// - it is best to prevent this unless the user explicitly asks to view the value with thread-slipping enabled.
//#if !PFX_LEGACY_3_5
// Debugger.NotifyOfCrossThreadDependency();
//#endif
Wait();
}
// Throw an exception if appropriate.
ThrowIfExceptional(!m_resultWasSet);
// We shouldn't be here if the result has not been set.
Contract.Assert(m_resultWasSet, "Task<T>.Result getter: Expected result to have been set.");
return m_result;
}
internal set
{
Contract.Assert(m_valueSelector == null, "Task<T>.Result_set: m_valueSelector != null");
if (!TrySetResult(value))
{
throw new InvalidOperationException(Strings.TaskT_TransitionToFinal_AlreadyCompleted);
}
}
}
If We call GetAwaiter
method of Task
, Task
will wrapped TaskAwaiter<TResult>
(Source code of GetAwaiter()), (Source code of TaskAwaiter) :
public TaskAwaiter GetAwaiter()
{
return new TaskAwaiter(this);
}
And If We call GetResult()
method of TaskAwaiter<TResult>
, it will call Task.Result
property, that Task.Result
will call Wait()
method of Task
( Source code of GetResult()):
public TResult GetResult()
{
TaskAwaiter.ValidateEnd(m_task);
return m_task.Result;
}
It is source code of ValidateEnd(Task task)
( Source code of ValidateEnd(Task task) ):
internal static void ValidateEnd(Task task)
{
if (task.Status != TaskStatus.RanToCompletion)
HandleNonSuccess(task);
}
private static void HandleNonSuccess(Task task)
{
if (!task.IsCompleted)
{
try { task.Wait(); }
catch { }
}
if (task.Status != TaskStatus.RanToCompletion)
{
ThrowForNonSuccess(task);
}
}
This is my conclusion:
As can be seen GetResult()
is calling TaskAwaiter.ValidateEnd(...)
, therefore Task.Result
is not same GetAwaiter.GetResult()
.
I think GetAwaiter().GetResult()
is a beter choice instead of .Result
because it don't wrap exceptions.
I read this at page 582 in C# 7 in a Nutshell (Joseph Albahari & Ben Albahari) book
If an antecedent task faults, the exception is re-thrown when the continuation code calls
awaiter.GetResult()
. Rather than callingGetResult
, we could simply access the Result property of the antecedent. The benefit of callingGetResult
is that if the antecedent faults, the exception is thrown directly without being wrapped inAggregateException
, allowing for simpler and cleaner catch blocks.
Source: C# 7 in a Nutshell's page 582
Note the guidelines for performing work on a UI thread, collected on my blog:
There are two techniques you should use:
1) Use ConfigureAwait(false)
when you can.
E.g., await MyAsync().ConfigureAwait(false);
instead of await MyAsync();
.
ConfigureAwait(false)
tells the await
that you do not need to resume on the current context (in this case, "on the current context" means "on the UI thread"). However, for the rest of that async
method (after the ConfigureAwait
), you cannot do anything that assumes you're in the current context (e.g., update UI elements).
For more information, see my MSDN article Best Practices in Asynchronous Programming.
2) Use Task.Run
to call CPU-bound methods.
You should use Task.Run
, but not within any code you want to be reusable (i.e., library code). So you use Task.Run
to call the method, not as part of the implementation of the method.
So purely CPU-bound work would look like this:
// Documentation: This method is CPU-bound.
void DoWork();
Which you would call using Task.Run
:
await Task.Run(() => DoWork());
Methods that are a mixture of CPU-bound and I/O-bound should have an Async
signature with documentation pointing out their CPU-bound nature:
// Documentation: This method is CPU-bound.
Task DoWorkAsync();
Which you would also call using Task.Run
(since it is partially CPU-bound):
await Task.Run(() => DoWorkAsync());
This worked for me. Go to Project->Propertied->Target Frawork->Change frame work like 3.5 to 4.0
jobs -l should give you the pid for the list of nohup processes. kill (-9) them gently. ;)
A search landed me at this page, but it wasn't quite what I was looking for. Posting here in case someone else looking for what I was lands at this page too.
There is two ways to do it if you only have a string value.
.NET way:
Same as @Canavar, but you can instantiate a new Uri Object
String URL = "http://localhost:1302/TESTERS/Default6.aspx";
System.Uri uri = new System.Uri(URL);
which means you can use the same methods, e.g.
string url = uri.AbsoluteUri;
// http://localhost:1302/TESTERS/Default6.aspx
string host = uri.host
// localhost
Regex way:
Swift 5: The Codable protocol can be used instead of NSKeyedArchiever.
struct User: Codable {
let id: String
let mail: String
let fullName: String
}
The Pref struct is custom wrapper around the UserDefaults standard object.
struct Pref {
static let keyUser = "Pref.User"
static var user: User? {
get {
if let data = UserDefaults.standard.object(forKey: keyUser) as? Data {
do {
return try JSONDecoder().decode(User.self, from: data)
} catch {
print("Error while decoding user data")
}
}
return nil
}
set {
if let newValue = newValue {
do {
let data = try JSONEncoder().encode(newValue)
UserDefaults.standard.set(data, forKey: keyUser)
} catch {
print("Error while encoding user data")
}
} else {
UserDefaults.standard.removeObject(forKey: keyUser)
}
}
}
}
So you can use it this way:
Pref.user?.name = "John"
if let user = Pref.user {...
Call System.Reflection.MethodBase.GetCurrentMethod().Name
from within the method.
The basic principle of centering a page is to have a body CSS and main_container CSS. It should look something like this:
body {
margin: 0;
padding: 0;
text-align: center;
}
#main_container {
margin: 0 auto;
text-align: left;
}
Sometimes you need to see the width/height changes while resizing the window and inner content.
For that I've written a little script that adds a log box that dynamicly monitors all the resizing and almost immediatly updates.
It adds a valid HTML with fixed position and high z-index, but is small enough, so you can:
Tested on: Chrome 40, IE11, but it is highly possible to work on other/older browsers too ... :)
function gebID(id){ return document.getElementById(id); }
function gebTN(tagName, parentEl){
if( typeof parentEl == "undefined" ) var parentEl = document;
return parentEl.getElementsByTagName(tagName);
}
function setStyleToTags(parentEl, tagName, styleString){
var tags = gebTN(tagName, parentEl);
for( var i = 0; i<tags.length; i++ ) tags[i].setAttribute('style', styleString);
}
function testSizes(){
gebID( 'screen.Width' ).innerHTML = screen.width;
gebID( 'screen.Height' ).innerHTML = screen.height;
gebID( 'window.Width' ).innerHTML = window.innerWidth;
gebID( 'window.Height' ).innerHTML = window.innerHeight;
gebID( 'documentElement.Width' ).innerHTML = document.documentElement.clientWidth;
gebID( 'documentElement.Height' ).innerHTML = document.documentElement.clientHeight;
gebID( 'body.Width' ).innerHTML = gebTN("body")[0].clientWidth;
gebID( 'body.Height' ).innerHTML = gebTN("body")[0].clientHeight;
}
var table = document.createElement('table');
table.innerHTML =
"<tr><th>SOURCE</th><th>WIDTH</th><th>x</th><th>HEIGHT</th></tr>"
+"<tr><td>screen</td><td id='screen.Width' /><td>x</td><td id='screen.Height' /></tr>"
+"<tr><td>window</td><td id='window.Width' /><td>x</td><td id='window.Height' /></tr>"
+"<tr><td>document<br>.documentElement</td><td id='documentElement.Width' /><td>x</td><td id='documentElement.Height' /></tr>"
+"<tr><td>document.body</td><td id='body.Width' /><td>x</td><td id='body.Height' /></tr>"
;
gebTN("body")[0].appendChild( table );
table.setAttribute(
'style',
"border: 2px solid black !important; position: fixed !important;"
+"left: 50% !important; top: 0px !important; padding:10px !important;"
+"width: 150px !important; font-size:18px; !important"
+"white-space: pre !important; font-family: monospace !important;"
+"z-index: 9999 !important;background: white !important;"
);
setStyleToTags(table, "td", "color: black !important; border: none !important; padding: 5px !important; text-align:center !important;");
setStyleToTags(table, "th", "color: black !important; border: none !important; padding: 5px !important; text-align:center !important;");
table.style.setProperty( 'margin-left', '-'+( table.clientWidth / 2 )+'px' );
setInterval( testSizes, 200 );
EDIT: Now styles are applied only to logger table element - not to all tables - also this is a jQuery-free solution :)
Deferred promises are a nice way to chain together function execution neatly and easily. Whether AJAX or normal functions, they offer greater flexibility than callbacks, and I've found easier to grasp.
function Typer()
{
var dfd = $.Deferred();
var srcText = 'EXAMPLE ';
var i = 0;
var result = srcText[i];
UPDATE :
////////////////////////////////
var timer= setInterval(function() {
if(i == srcText.length) {
// clearInterval(this);
clearInterval(timer);
////////////////////////////////
dfd.resolve();
};
i++;
result += srcText[i].replace("\n", "<br />");
$("#message").html( result);
},
100);
return dfd.promise();
}
I've modified the play function so it returns a promise when the audio finishes playing, which might be useful to some. The third function fires when sound finishes playing.
function playBGM()
{
var playsound = $.Deferred();
$('#bgm')[0].play();
$("#bgm").on("ended", function() {
playsound.resolve();
});
return playsound.promise();
}
function thirdFunction() {
alert('third function');
}
Now call the whole thing with the following: (be sure to use Jquery 1.9.1 or above as I found that 1.7.2 executes all the functions at once, rather than waiting for each to resolve.)
Typer().then(playBGM).then(thirdFunction);
Before today, I had no luck using deferred promises in this way, and finally have grasped it. Precisely timed, chained interface events occurring exactly when we want them to, including async events, has never been easy. For me at least, I now have it under control thanks largely to others asking questions here.
It seems that when this error appears it is an indication that the selenium-java plugin for maven is out-of-date.
Changing the version in the pom.xml should fix the problem
You didn't specify how the order is determined, but this will give you a rank value in MySQL:
SELECT t.*,
@rownum := @rownum +1 AS rank
FROM TBL_FOO t
JOIN (SELECT @rownum := 0) r
WHERE t.name = 'sarmen'
Then you can pick out what rows you want, based on the rank value.
Code example:
HashMap<Integer,String> h = new HashMap<Integer,String> ();
h.put(null,null);
h.put(null, "a");
System.out.println(h);
Output:
{null=a}
There are many ways to add an element to an array. You can use a temp List
to manage the element and then convert it back to Array
or you can use the java.util.Arrays.copyOf
and combine it with generics for better results.
This example will show you how:
public static <T> T[] append2Array(T[] elements, T element)
{
T[] newArray = Arrays.copyOf(elements, elements.length + 1);
newArray[elements.length] = element;
return newArray;
}
To use this method you just need to call it like this:
String[] numbers = new String[]{"one", "two", "three"};
System.out.println(Arrays.toString(numbers));
numbers = append2Array(numbers, "four");
System.out.println(Arrays.toString(numbers));
If you want to merge two array you can modify the previous method like this:
public static <T> T[] append2Array(T[] elements, T[] newElements)
{
T[] newArray = Arrays.copyOf(elements, elements.length + newElements.length);
System.arraycopy(newElements, 0, newArray, elements.length, newElements.length);
return newArray;
}
Now you can call the method like this:
String[] numbers = new String[]{"one", "two", "three"};
String[] moreNumbers = new String[]{"four", "five", "six"};
System.out.println(Arrays.toString(numbers));
numbers = append2Array(numbers, moreNumbers);
System.out.println(Arrays.toString(numbers));
As I mentioned, you also may use List
objects. However, it will require a little hack to cast it safe like this:
public static <T> T[] append2Array(Class<T[]> clazz, List<T> elements, T element)
{
elements.add(element);
return clazz.cast(elements.toArray());
}
Now you can call the method like this:
String[] numbers = new String[]{"one", "two", "three"};
System.out.println(Arrays.toString(numbers));
numbers = append2Array(String[].class, Arrays.asList(numbers), "four");
System.out.println(Arrays.toString(numbers));
I do it like this (to retrieve a specific get-parameter, here 'parameterName'):
var parameterValue = decodeURIComponent(window.location.search.match(/(\?|&)parameterName\=([^&]*)/)[2]);
I kind of run into the same issue. I wanted my message box to display the message and the vendorcontractexpiration. This is what I did:
Dim ab As String
Dim cd As String
ab = "THE CONTRACT FOR THIS VENDOR WILL EXPIRE ON "
cd = VendorContractExpiration
If InvoiceDate >= VendorContractExpiration - 120 And InvoiceDate < VendorContractExpiration Then
MsgBox [ab] & [cd], vbCritical, "WARNING"
End If
You need to know the gateway! My solution with local server was to expose it under 0.0.0.0:8000
, then run docker with subnet and run container like:
docker network create --subnet=172.35.0.0/16 --gateway 172.35.0.1 SUBNET35
docker run -d -p 4444:4444 --net SUBNET35 <container-you-want-run-place-here>
So, now you can access your loopback through http://172.35.0.1:8000
A very simple way if your code is in Python, where I didn't have to install a Python package, is the following:
\documentclass[11pt]{article}
\usepackage{pythonhighlight}
\begin{document}
The following is some Python code
\begin{python}
# A comment
x = [5, 7, 10]
y = 0
for num in x:
y += num
print(y)
\end{python}
\end{document}
Unfortunately, this only works for Python.
For general command-line automation, Expect is the classic tool. Or try pexpect if you're more comfortable with Python.
Here's a similar question that suggests using Expect: Use expect in bash script to provide password to SSH command
same for Terminator
Ctrl + Shift + V
Look at your terminal key-bindings if any if that doesn't work
Enclose your code with the html and body tags. Size attribute does not correspond to font-size and it looks like its domain does not go beyond value 7. Furthermore font tag is not supported in HTML5. Consider this code for your case
<!DOCTYPE html>
<html>
<body>
<font size="2" face="Courier New" >
<table width="100%">
<tr>
<td><b>Client</b></td>
<td><b>InstanceName</b></td>
<td><b>dbname</b></td>
<td><b>Filename</b></td>
<td><b>KeyName</b></td>
<td><b>Rotation</b></td>
<td><b>Path</b></td>
</tr>
<tr>
<td>NEWDEV6</td>
<td>EXPRESS2012</td>
<td>master</td><td>master.mdf</td>
<td>test_key_16</td><td>0</td>
<td>d:\Program Files\Microsoft SQL Server\MSSQL11.EXPRESS2012\MSSQL\DATA\master.mdf</td>
</tr>
</table>
</font>
<font size="5" face="Courier New" >
<table width="100%">
<tr>
<td><b>Client</b></td>
<td><b>InstanceName</b></td>
<td><b>dbname</b></td>
<td><b>Filename</b></td>
<td><b>KeyName</b></td>
<td><b>Rotation</b></td>
<td><b>Path</b></td></tr>
<tr>
<td>NEWDEV6</td>
<td>EXPRESS2012</td>
<td>master</td>
<td>master.mdf</td>
<td>test_key_16</td>
<td>0</td>
<td>d:\Program Files\Microsoft SQL Server\MSSQL11.EXPRESS2012\MSSQL\DATA\master.mdf</td></tr>
</table></font>
</body>
</html>
Use ClassLoader#getResource()
instead if its URI represents a valid local disk file system path.
URL resource = classLoader.getResource("resource.ext");
File file = new File(resource.toURI());
FileInputStream input = new FileInputStream(file);
// ...
If it doesn't (e.g. JAR), then your best bet is to copy it into a temporary file.
Path temp = Files.createTempFile("resource-", ".ext");
Files.copy(classLoader.getResourceAsStream("resource.ext"), temp, StandardCopyOption.REPLACE_EXISTING);
FileInputStream input = new FileInputStream(temp.toFile());
// ...
That said, I really don't see any benefit of doing so, or it must be required by a poor helper class/method which requires FileInputStream
instead of InputStream
. If you can, just fix the API to ask for an InputStream
instead. If it's a 3rd party one, by all means report it as a bug. I'd in this specific case also put question marks around the remainder of that API.
LayoutInflater.inflate() provides a means to convert a res/layout/*.xml file defining a view into an actual View object usable in your application source code.
basic two steps: get the inflater and then inflate the resource
How do you get the inflater?
LayoutInflater inflater = (LayoutInflater) context
.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
How do you get the view assuming the xml file is "list_item.xml"?
View view = inflater.inflate(R.layout.list_item, parent, false);
The BLOB datatype is best for storing files.
Currently the best documentation is the source. You can take a look at it here (attrs.xml).
You can define attributes in the top <resources>
element or inside of a <declare-styleable>
element. If I'm going to use an attr in more than one place I put it in the root element. Note, all attributes share the same global namespace. That means that even if you create a new attribute inside of a <declare-styleable>
element it can be used outside of it and you cannot create another attribute with the same name of a different type.
An <attr>
element has two xml attributes name
and format
. name
lets you call it something and this is how you end up referring to it in code, e.g., R.attr.my_attribute
. The format
attribute can have different values depending on the 'type' of attribute you want.
You can set the format to multiple types by using |
, e.g., format="reference|color"
.
enum
attributes can be defined as follows:
<attr name="my_enum_attr">
<enum name="value1" value="1" />
<enum name="value2" value="2" />
</attr>
flag
attributes are similar except the values need to be defined so they can be bit ored together:
<attr name="my_flag_attr">
<flag name="fuzzy" value="0x01" />
<flag name="cold" value="0x02" />
</attr>
In addition to attributes there is the <declare-styleable>
element. This allows you to define attributes a custom view can use. You do this by specifying an <attr>
element, if it was previously defined you do not specify the format
. If you wish to reuse an android attr, for example, android:gravity, then you can do that in the name
, as follows.
An example of a custom view <declare-styleable>
:
<declare-styleable name="MyCustomView">
<attr name="my_custom_attribute" />
<attr name="android:gravity" />
</declare-styleable>
When defining your custom attributes in XML on your custom view you need to do a few things. First you must declare a namespace to find your attributes. You do this on the root layout element. Normally there is only xmlns:android="http://schemas.android.com/apk/res/android"
. You must now also add xmlns:whatever="http://schemas.android.com/apk/res-auto"
.
Example:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:whatever="http://schemas.android.com/apk/res-auto"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent">
<org.example.mypackage.MyCustomView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:gravity="center"
whatever:my_custom_attribute="Hello, world!" />
</LinearLayout>
Finally, to access that custom attribute you normally do so in the constructor of your custom view as follows.
public MyCustomView(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.MyCustomView, defStyle, 0);
String str = a.getString(R.styleable.MyCustomView_my_custom_attribute);
//do something with str
a.recycle();
}
The end. :)
You can't style buttons as links reliably throughout browsers. I've tried it, but there's always some weird padding, margin or font issues in some browser. Either live with letting the button look like a button, or use onClick and preventDefault on a link.
Look at Compare-Object
Compare-Object $a1 $b1 | ForEach-Object { $_.InputObject }
Or if you would like to know where the object belongs to, then look at SideIndicator:
$a1=@(1,2,3,4,5,8)
$b1=@(1,2,3,4,5,6)
Compare-Object $a1 $b1
If you just put '/' in the href it will reload the current window.
<a href="/">
Reload the page
</a>
_x000D_
Are you applying a RowFilter to your DefaultView later in the code? This could change the results returned.
I would also avoid using the string as the display member if you have a direct reference the the data column I would use the object properties:
mnuActionLanguage.ComboBox.DataSource = lTable.DefaultView;
mnuActionLanguage.ComboBox.DisplayMember = lName.ColumnName;
I have tried this with a blank form and standard combo, and seems to work for me.
A bit more readable one, map
it to an array of single-element hashes and reduce
that with merge
the_hash.map{ |key,value| {key => "%#{value}%"} }.reduce(:merge)
Double click on the home button and then click and hold the icon like a normal phone and then click close I believe.
Exporting the DISPLAY
variable is definitely the solution but depending on your setup you may have to do this in a slightly different way.
In my case, I have two different processes: the first one starts Xvfb, the other one launches the tests. So my shell scripting knowledge is a bit rusty but I figured out that exporting the DISPLAY
variable from the first process didn't make it available in the second process.
Fortunately, Selenium WebDriver allows you to 'redefine' your environment. This is my function for creating a driver for Chrome in JS. Pretty sure the equivalent exists for your programming language:
const caps = require('selenium-webdriver/lib/capabilities');
const chrome = require('selenium-webdriver/chrome');
const chromedriver = require('chromedriver');
module.exports = function (cfg) {
let serviceBuilder = new chrome.ServiceBuilder(chromedriver.path);
let options = chrome.Options.fromCapabilities(caps.Capabilities.chrome());
let service;
let myENV = new Map();
// 're-export' the `DISPLAY` variable
myENV.set('DISPLAY', ':1');
serviceBuilder.setEnvironment(myENV);
service = serviceBuilder.build();
options.addArguments('disable-setuid-sandbox');
options.addArguments('no-sandbox');
options.addArguments('allow-insecure-localhost');
options.excludeSwitches('test-type');
return chrome.Driver.createSession(options, service);
};
You don't need a whole function for this; a simple cast will suffice:
int x;
static_cast<char*>(static_cast<void*>(&x));
Any object in C++ can be reinterpreted as an array of bytes. If you want to actually make a copy of the bytes into a separate array, you can use std::copy
:
int x;
char bytes[sizeof x];
std::copy(static_cast<const char*>(static_cast<const void*>(&x)),
static_cast<const char*>(static_cast<const void*>(&x)) + sizeof x,
bytes);
Neither of these methods takes byte ordering into account, but since you can reinterpret the int
as an array of bytes, it is trivial to perform any necessary modifications yourself.
maybe you forget to add parameter dataType:'json' in your $.ajax
$.ajax({
type: "POST",
dataType: "json",
url: url,
data: { get_member: id },
success: function( response )
{
//some action here
},
error: function( error )
{
alert( error );
}
});
You're misinformed about fcntl()
not always being reliable. It's untrue.
To mark a socket as non-blocking the code is as simple as:
// where socketfd is the socket you want to make non-blocking
int status = fcntl(socketfd, F_SETFL, fcntl(socketfd, F_GETFL, 0) | O_NONBLOCK);
if (status == -1){
perror("calling fcntl");
// handle the error. By the way, I've never seen fcntl fail in this way
}
Under Linux, on kernels > 2.6.27 you can also create sockets non-blocking from the outset using socket()
and accept4()
.
e.g.
// client side
int socketfd = socket(AF_INET, SOCK_STREAM | SOCK_NONBLOCK, 0);
// server side - see man page for accept4 under linux
int socketfd = accept4( ... , SOCK_NONBLOCK);
It saves a little bit of work, but is less portable so I tend to set it with fcntl()
.
putExtra() : This method sends the data to another activity and in parameter, we have to pass key-value pair.
Syntax: intent.putExtra("key", value);
Eg: intent.putExtra("full_name", "Vishnu Sivan");
Intent intent=getIntent()
: It gets the Intent from the previous activity.
fullname = intent.getStringExtra(“full_name”)
: This line gets the string form previous activity and in parameter, we have to pass the key which we have mentioned in previous activity.
Sample Code:
Intent intent = new Intent(getApplicationContext(), MainActivity.class);
intent.putExtra("firstName", "Vishnu");
intent.putExtra("lastName", "Sivan");
startActivity(intent);
MS' free SQL Server 2008 Express (with Advanced Services) looks to include reporting services.
http://www.microsoft.com/express/sql/download/
Here how reporting features differ from the full version: http://msdn.microsoft.com/en-us/library/ms365166.aspx
EDIT: I don't know if this works in winforms but it still looks useful.
const url = 'data:image/png;base6....';
fetch(url)
.then(res => res.blob())
.then(blob => {
const file = new File([blob], "File name",{ type: "image/png" })
})
Base64 String -> Blob -> File.
Why not just this in that case?
args = ['A', 'C']
sql = 'SELECT fooid FROM foo WHERE bar IN (%s)'
in_p =', '.join(list(map(lambda arg: "'%s'" % arg, args)))
sql = sql % in_p
cursor.execute(sql)
results in:
SELECT fooid FROM foo WHERE bar IN ('A', 'C')
I had permissions issue, after given the right permissions i was able to push the contents. I was pushing a existing project into a new git repo.
I found that there is height of div still showing, when it have text or not. So you can use this for best results.
<div style=" overflow:auto;max-height:300px; max-width:300px;"></div>
(From the mailing list. I didn't come up with this answer.)
class _FooState extends State<Foo> {
TextEditingController _controller;
@override
void initState() {
super.initState();
_controller = new TextEditingController(text: 'Initial value');
}
@override
Widget build(BuildContext context) {
return new Column(
children: <Widget>[
new TextField(
// The TextField is first built, the controller has some initial text,
// which the TextField shows. As the user edits, the text property of
// the controller is updated.
controller: _controller,
),
new RaisedButton(
onPressed: () {
// You can also use the controller to manipuate what is shown in the
// text field. For example, the clear() method removes all the text
// from the text field.
_controller.clear();
},
child: new Text('CLEAR'),
),
],
);
}
}
IIF
is the same as CASE WHEN <Condition> THEN <true part> ELSE <false part> END
. The query plan will be the same. It is, perhaps, "syntactical sugar" as initially implemented.
CASE is portable across all SQL platforms whereas IIF is SQL SERVER 2012+ specific.
The browser might not be able to detect that your form is a login form. According to some of the discussion in this previous question, a browser looks for form fields that look like <input type="password">
. Is your password form field implemented similar to that?
Edit: To answer your questions below, I think Firefox detects passwords by form.elements[n].type == "password"
(iterating through all form elements) and then detects the username field by searching backwards through form elements for the text field immediately before the password field (more info here). From what I can tell, your login form needs to be part of a <form>
or Firefox won't detect it.
*{font-family:Algerian;}
this html worked for me. Added to canvas settings in wordpress.
Looks cool - thanks !
Encoding.GetString Method (Byte[]) convert bytes to a string.
When overridden in a derived class, decodes all the bytes in the specified byte array into a string.
Namespace: System.Text
Assembly: mscorlib (in mscorlib.dll)
Syntax
public virtual string GetString(byte[] bytes)
Parameters
bytes
Type: System.Byte[]
The byte array containing the sequence of bytes to decode.
Return Value
Type: System.String
A String containing the results of decoding the specified sequence of bytes.
Exceptions
ArgumentException - The byte array contains invalid Unicode code points.
ArgumentNullException - bytes is null.
DecoderFallbackException - A fallback occurred (see Character Encoding in the .NET Framework for complete explanation) or DecoderFallback is set to DecoderExceptionFallback.
Remarks
If the data to be converted is available only in sequential blocks (such as data read from a stream) or if the amount of data is so large that it needs to be divided into smaller blocks, the application should use the Decoder or the Encoder provided by the GetDecoder method or the GetEncoder method, respectively, of a derived class.
See the Remarks under Encoding.GetChars for more discussion of decoding techniques and considerations.
I never tried using formArray, I have always worked with FormGroup, and you can remove all controls using:
Object.keys(this.formGroup.controls).forEach(key => {
this.formGroup.removeControl(key);
});
being formGroup an instance of FormGroup.
IMO, froadie's simple concatenation is fine for a simple case like you presented. If you want to put together several strings, the string join method seems to be preferred:
the_text = ''.join(['the ', 'quick ', 'brown ', 'fox ', 'jumped ', 'over ', 'the ', 'lazy ', 'dog.'])
Edit: Note that join wants an iterable (e.g. a list) as its single argument.
Although there are already excellent answers are provided by users such as encouraging use of GSON etc. I would like to suggest use of org.json. It includes most of GSON functionalities. It also allows you to pass json string as an argument to it's JSONObject and it will take care of rest e.g:
JSONObject json = new JSONObject("some random json string");
This functionality make it my personal favorite.
Set JAVA_HOME
in environment variable.
set JAVA_HOME
to only JDK1.6.0_23
or whatever jdk folder
you have. dont include bin
folder in path.
class Obj:
def __init__(self,a):
self.value = a
def sum(self, a):
self.value += a
a = Obj(1)
b = a
a.sum(1)
print(a.value, b.value)// 2 2
Set the value and trigger the change event immediately.
$('#selectteam').val([183,182]).trigger('change');
"Core Java" is Sun's term, used to refer to Java SE, the standard edition and a set of related technologies, like the Java VM, CORBA, et cetera. This is mostly to differentiate from, say, Java ME or Java EE.
Also note that they're talking about a set of libraries rather than the programming language. That is, the underlying way you write Java doesn't change, regardless of the libraries you're using.
You will need to define "special characters", but it's likely that for some string s
you mean:
import re
if re.match(r'^\w+$', s):
# s is good-to-go
You can do it like:
change_column :table_name, :column_name, 'integer USING CAST(column_name AS integer)'
or try this:
change_column :table_name, :column_name, :integer, using: 'column_name::integer'
If you are interested to find more about this topic read this article: https://kolosek.com/rails-change-database-column
Looking at the "effective POM" will probably help too. For instance, if you wanted to know what the path is for ${project.build.sourceDirectory}
you would find the related XML in the effective POM, such as:
<project>
<build>
<sourceDirectory>/my/path</sourceDirectory>
Also helpful - you can do a real time evaluation of properties via the command line execution of mvn help:evaluate
while in the same dir as the POM.
There are two ways to go about this. You can either use the IDE to generate a WSDL, or you can do it via the command line.
1. To create it via the IDE:
In the solution explorer pane, right click on the project that you would like to add the Service to:
Then, you can enter the path to your service WSDL and hit go:
2. To create it via the command line:
Open a VS 2010 Command Prompt (Programs -> Visual Studio 2010 -> Visual Studio Tools)
Then execute:
WSDL /verbose C:\path\to\wsdl
WSDL.exe will then output a .cs file for your consumption.
If you have other dependencies that you received with the file, such as xsd's, add those to the argument list:
WSDL /verbose C:\path\to\wsdl C:\path\to\some\xsd C:\path\to\some\xsd
If you need VB output, use /language:VB
in addition to the /verbose
.
To improve on @bgporter's answer, with Python-3 you will probably want to operate on bytes instead of needlessly converting things to utf-8:
>>> import shutil
>>> import sys
>>> with open("test.txt", "rb") as f:
... shutil.copyfileobj(f, sys.stdout.buffer)
While it seems the question was answered per the OP's request, none of the answers give a good way to get a datetime.date
object instead of a datetime.datetime
. So for those searching and finding this thread:
datetime.date
has no .strptime
method; use the one on datetime.datetime
instead and then call .date()
on it to receive the datetime.date
object.
Like so:
>>> from datetime import datetime
>>> datetime.strptime('2014-12-04', '%Y-%m-%d').date()
datetime.date(2014, 12, 4)
It seems pretty consistent to me; positive indices are also non-inclusive. I think you're doing it wrong. Remembering that range() is also non-inclusive, and that Python arrays are 0-indexed, here's a sample python session to illustrate:
>>> d = range(10)
>>> d
[0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
>>> d[9]
9
>>> d[-1]
9
>>> d[0:9]
[0, 1, 2, 3, 4, 5, 6, 7, 8]
>>> d[0:-1]
[0, 1, 2, 3, 4, 5, 6, 7, 8]
>>> len(d)
10
I wrote a post a few months back on how to set up user registration and login functionality with Angular, you can check it out at http://jasonwatmore.com/post/2015/03/10/AngularJS-User-Registration-and-Login-Example.aspx
I check if the user is logged in the $locationChangeStart
event, here is my main app.js showing this:
(function () {
'use strict';
angular
.module('app', ['ngRoute', 'ngCookies'])
.config(config)
.run(run);
config.$inject = ['$routeProvider', '$locationProvider'];
function config($routeProvider, $locationProvider) {
$routeProvider
.when('/', {
controller: 'HomeController',
templateUrl: 'home/home.view.html',
controllerAs: 'vm'
})
.when('/login', {
controller: 'LoginController',
templateUrl: 'login/login.view.html',
controllerAs: 'vm'
})
.when('/register', {
controller: 'RegisterController',
templateUrl: 'register/register.view.html',
controllerAs: 'vm'
})
.otherwise({ redirectTo: '/login' });
}
run.$inject = ['$rootScope', '$location', '$cookieStore', '$http'];
function run($rootScope, $location, $cookieStore, $http) {
// keep user logged in after page refresh
$rootScope.globals = $cookieStore.get('globals') || {};
if ($rootScope.globals.currentUser) {
$http.defaults.headers.common['Authorization'] = 'Basic ' + $rootScope.globals.currentUser.authdata; // jshint ignore:line
}
$rootScope.$on('$locationChangeStart', function (event, next, current) {
// redirect to login page if not logged in and trying to access a restricted page
var restrictedPage = $.inArray($location.path(), ['/login', '/register']) === -1;
var loggedIn = $rootScope.globals.currentUser;
if (restrictedPage && !loggedIn) {
$location.path('/login');
}
});
}
})();
Why not using LEFT(string, length) function instead of substring.
LEFT(col,char_length(col)-2)
you can visit here https://dev.mysql.com/doc/refman/5.7/en/string-functions.html#function_left to know more about Mysql String Functions.
Like @ said
https://services.gradle.org/distributions/
Download The Latest Gradle Distribution File and Extract It, Then Copy all Files and Paste it Under:
C:\Users\{USERNAME}\.gradle\wrapper\dists\
but you have to first make Android Studio try downloading the zip file and cancel it.
That way you can get the hash and copy the file and put it under the hash
Below code utilizes System.Drawing.Bitmap
to load the image.
using System.Drawing;
using System.Drawing.Imaging;
public IActionResult Get()
{
string filename = "Image/test.jpg";
var bitmap = new Bitmap(filename);
var ms = new System.IO.MemoryStream();
bitmap.Save(ms, ImageFormat.Jpeg);
ms.Position = 0;
return new FileStreamResult(ms, "image/jpeg");
}
LocalDateTime.parse( // Parse into an object representing a date with a time-of-day but without time zone and without offset-from-UTC.
"2014/10/29 18:10:45" // Convert input string to comply with standard ISO 8601 format.
.replace( " " , "T" ) // Replace SPACE in the middle with a `T`.
.replace( "/" , "-" ) // Replace SLASH in the middle with a `-`.
)
.atZone( // Apply a time zone to provide the context needed to determine an actual moment.
ZoneId.of( "Europe/Oslo" ) // Specify the time zone you are certain was intended for that input.
) // Returns a `ZonedDateTime` object.
.toInstant() // Adjust into UTC.
.toEpochMilli() // Get the number of milliseconds since first moment of 1970 in UTC, 1970-01-01T00:00Z.
1414602645000
The accepted answer is correct, except that it ignores the crucial issue of time zone. Is your input string 6:10 PM in Paris or Montréal? Or UTC?
Use a proper time zone name. Usually a continent plus city/region. For example, "Europe/Oslo"
. Avoid the 3 or 4 letter codes which are neither standardized nor unique.
The modern approach uses the java.time classes.
Alter your input to conform with the ISO 8601 standard. Replace the SPACE in the middle with a T
. And replace the slash characters with hyphens. The java.time classes use these standard formats by default when parsing/generating strings. So no need to specify a formatting pattern.
String input = "2014/10/29 18:10:45".replace( " " , "T" ).replace( "/" , "-" ) ;
LocalDateTime ldt = LocalDateTime.parse( input ) ;
A LocalDateTime
, like your input string, lacks any concept of time zone or offset-from-UTC. Without the context of a zone/offset, a LocalDateTime
has no real meaning. Is it 6:10 PM in India, Europe, or Canada? Each of those places experience 6:10 PM at different moments, at different points on the timeline. So you must specify which you have in mind if you want to determine a specific point on the timeline.
ZoneId z = ZoneId.of( "Europe/Oslo" ) ;
ZonedDateTime zdt = ldt.atZone( z ) ;
Now we have a specific moment, in that ZonedDateTime
. Convert to UTC by extracting a Instant
. The Instant
class represents a moment on the timeline in UTC with a resolution of nanoseconds (up to nine (9) digits of a decimal fraction).
Instant instant = zdt.toInstant() ;
Now we can get your desired count of milliseconds since the epoch reference of first moment of 1970 in UTC, 1970-01-01T00:00Z.
long millisSinceEpoch = instant.toEpochMilli() ;
Be aware of possible data loss. The Instant
object is capable of carrying microseconds or nanoseconds, finer than milliseconds. That finer fractional part of a second will be ignored when getting a count of milliseconds.
The java.time framework is built into Java 8 and later. These classes supplant the troublesome old legacy date-time classes such as java.util.Date
, Calendar
, & SimpleDateFormat
.
The Joda-Time project, now in maintenance mode, advises migration to the java.time classes.
To learn more, see the Oracle Tutorial. And search Stack Overflow for many examples and explanations. Specification is JSR 310.
You may exchange java.time objects directly with your database. Use a JDBC driver compliant with JDBC 4.2 or later. No need for strings, no need for java.sql.*
classes.
Where to obtain the java.time classes?
The ThreeTen-Extra project extends java.time with additional classes. This project is a proving ground for possible future additions to java.time. You may find some useful classes here such as Interval
, YearWeek
, YearQuarter
, and more.
Update: The Joda-Time project is now in maintenance mode, with the team advising migration to the java.time classes. I will leave this section intact for history.
Below is the same kind of code but using the Joda-Time 2.5 library and handling time zone.
The java.util.Date, .Calendar, and .SimpleDateFormat classes are notoriously troublesome, confusing, and flawed. Avoid them. Use either Joda-Time or the java.time package (inspired by Joda-Time) built into Java 8.
Your string is almost in ISO 8601 format. The slashes need to be hyphens and the SPACE in middle should be replaced with a T
. If we tweak that, then the resulting string can be fed directly into constructor without bothering to specify a formatter. Joda-Time uses ISO 8701 formats as it's defaults for parsing and generating strings.
String inputRaw = "2014/10/29 18:10:45";
String input = inputRaw.replace( "/", "-" ).replace( " ", "T" );
DateTimeZone zone = DateTimeZone.forID( "Europe/Oslo" ); // Or DateTimeZone.UTC
DateTime dateTime = new DateTime( input, zone );
long millisecondsSinceUnixEpoch = dateTime.getMillis();
just add /FORCE as linker flag and you're all set.
for instance, if you're working on CMakeLists.txt. Then add following line:
SET(CMAKE_EXE_LINKER_FLAGS "/FORCE")
I ran into the same error, and in my case it was a simple matter of going to Project Properties > Maven > Update project
and/or cleaning and rebuilding the project.
console.log('Hello, \n' +
'Text under your Header\n' +
'-------------------------\n' +
'More Text\n' +
'Moree Text\n' +
'Moooooer Text\n' );
This works great for me for text only, and easy on the eye.
This is due to a bug in Webkit.
You can work around the Webkit bug using createEvent('Event')
rather than createEvent('KeyboardEvent')
, and then assigning the keyCode
property. See this answer and this example.
Wow I am real late to this party but it has had activity 17 days ago It would seam we need to consider posting what version of Android we are using for an answer so as of now this answer works with Android 2.1 and above Go to RES/VALUES/STYLES and add the lines of code below and your cursor will be black
<style name="AppTheme" parent="Theme.AppCompat.NoActionBar">
<!--<style name="AppTheme" parent="Theme.AppCompat.Light.NoActionBar">-->
<!-- Customize your theme here. -->
<item name="colorControlActivated">@color/color_Black</item>
<!--Sets COLOR for the Cursor in EditText -->
</style>
You will need a this line of code in your RES/COLOR folder
<color name="color_Black">#000000</color>
Why post this late ? It might be nice to consider some form of categories for the many headed monster Android has become!
We can add for this:
@Transactional(readOnly = true)
public class Banking_CustomerService implements CustomerService {
public Customer getDetail(String customername) {
// do something
}
// these settings have precedence for this method
@Transactional(readOnly = false, propagation = Propagation.REQUIRES_NEW)
public void updateCustomer(Customer customer) {
// do something
}
}
If your project is Dll, then the case might be that linker wants to build a console program. Open the project properties. Select the General settings. Select configuration type Dynamic Library there(.dll).
You could subclass ArrayList, and call Collections.sort(this) after any element is added - you would need to override two versions of add, and two of addAll, to do this.
Performance would not be as good as a smarter implementation which inserted elements in the right place, but it would do the job. If addition to the list is rare, the cost amortised over all operations on the list should be low.
Under Chrome v51 on a Mac, I found the rendering settings by clicking in the upper right corner, choosing More tools > Rendering settings and checking the Emulate media button in the options offered at the bottom of the window.
Thank you to all the other posters that led me to this, and credit to those that provided the answer without the images.
I think you can try to load that csv into a RDD and then create a dataframe from that RDD, here is the document of creating dataframe from rdd:http://spark.apache.org/docs/latest/sql-programming-guide.html#interoperating-with-rdds
Here is my version, written for small microcontroller applications, MISRA-C compliant. The main aim with this code was to write readable code, instead of the one-line goo found in most compiler libs.
int8_t strcmp (const uint8_t* s1, const uint8_t* s2)
{
while ( (*s1 != '\0') && (*s1 == *s2) )
{
s1++;
s2++;
}
return (int8_t)( (int16_t)*s1 - (int16_t)*s2 );
}
Note: the code assumes 16 bit int
type.
If you have Pillow
installed with scipy
and it is still giving you error then check your scipy
version because it has been removed from scipy since 1.3.0rc1
.
rather install scipy 1.1.0
by :
pip install scipy==1.1.0
check https://github.com/scipy/scipy/issues/6212
The method imread
in scipy.misc
requires the forked package of PIL
named Pillow
. If you are having problem installing the right version of PIL try using imread
in other packages:
from matplotlib.pyplot import imread
im = imread(image.png)
To read jpg
images without PIL
use:
import cv2 as cv
im = cv.imread(image.jpg)
You can try
from scipy.misc.pilutil import imread
instead of from scipy.misc import imread
Please check the GitHub page : https://github.com/amueller/mglearn/issues/2 for more details.
Here is a base R one liner that overlaps a number of previous solutions, but returns a data.frame with the proper names.
out <- setNames(data.frame(before$attr,
do.call(rbind, strsplit(as.character(before$type),
split="_and_"))),
c("attr", paste0("type_", 1:2)))
out
attr type_1 type_2
1 1 foo bar
2 30 foo bar_2
3 4 foo bar
4 6 foo bar_2
It uses strsplit
to break up the variable, and data.frame
with do.call
/rbind
to put the data back into a data.frame. The additional incremental improvement is the use of setNames
to add variable names to the data.frame.
//img[@title='Modify'][i]
is short for
/descendant-or-self::node()/img[@title='Modify'][i]
hence is returning the i'th node under the same parent node.
You want
/descendant-or-self::img[@title='Modify'][i]
try by this
if(!Yii::$app->request->getIsPost())
{
Yii::$app->response->redirect(array('user/index','id'=>302));
exit(0);
}
With layout_weight
you can specify a size ratio between multiple views. E.g. you have a MapView
and a table
which should show some additional information to the map. The map should use 3/4 of the screen and table should use 1/4 of the screen. Then you will set the layout_weight
of the map
to 3 and the layout_weight
of the table
to 1.
To get it work you also have to set the height or width (depending on your orientation) to 0px.
Blockquote
Using concatenation in Oracle SQL is very easy and interesting. But don't know much about MS-SQL.
Blockquote
Here we go for Oracle :
Syntax:
SQL> select First_name||Last_Name as Employee
from employees;
EllenAbel SundarAnde MozheAtkinson
Here AS: keyword used as alias. We can concatenate with NULL values. e.g. : columnm1||Null
Suppose any of your columns contains a NULL value then the result will show only the value of that column which has value.
You can also use literal character string in concatenation.
e.g.
select column1||' is a '||column2
from tableName;
Result: column1 is a column2.
in between literal should be encolsed in single quotation. you cna exclude numbers.
NOTE: This is only for oracle server//SQL.
From Official documents about Re-using Layouts
Although Android offers a variety of widgets to provide small and re-usable interactive elements, you might also need to re-use larger components that require a special layout. To efficiently re-use complete layouts, you can use the tag to embed another layout inside the current layout.
Here is my header.xml file which i can reuse using include tag
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:background="#FFFFFF"
>
<TextView
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:layout_centerHorizontal="true"
android:layout_centerVertical="true"
android:gravity="center"
android:text="@string/app_name"
android:textColor="#000000" />
</RelativeLayout>
No I use the tag in XML to add another layout from another XML file.
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:background="#f0f0f0" >
<include
android:id="@+id/header_VIEW"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
layout="@layout/header" />
<LinearLayout
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_margin="5dp"
android:background="#ffffff"
android:orientation="vertical"
android:padding="5dp" >
</LinearLayout>
This is a 10 years old question, but anyway here's what worked for me. I'm using MySQL 8.0 with Hibernate 5 and SpringBoot 4.
I've tried the above accepted answer but didn't work for me, what worked for me is this:
db.url=jdbc:mysql://localhost:3306/testdb?useSSL=false&serverTimezone=Europe/Warsaw
If this helps you don't forget to upvote it :D
The problem that I had with the change
handler was that it triggered on every keypress that I scrolled up and down the <select>
.
I wanted to get the event for whenever an option was clicked or when enter
was pressed on the desired option. This is how I ended up doing it:
let blockChange = false;
$element.keydown(function (e) {
const keycode = (e.keyCode ? e.keyCode : e.which);
// prevents select opening when enter is pressed
if (keycode === 13) {
e.preventDefault();
}
// lets the change event know that these keypresses are to be ignored
if([38, 40].indexOf(keycode) > -1){
blockChange = true;
}
});
$element.keyup(function(e) {
const keycode = (e.keyCode ? e.keyCode : e.which);
// handle enter press
if(keycode === 13) {
doSomething();
}
});
$element.change(function(e) {
// this effective handles the click only as preventDefault was used on enter
if(!blockChange) {
doSomething();
}
blockChange = false;
});
Your flex items have
flex: 0 0 200px; /* <aside> */
flex: 1 0 auto; /* <article> */
That means:
The <aside>
will start at 200px
wide.
Then it won't grow nor shrink.
The <article>
will start at the width given by the content.
Then, if there is available space, it will grow to cover it.
Otherwise it won't shrink.
To prevent horizontal overflow, you can:
flex-basis: 0
and then let them grow with a positive flex-grow
.flex-shrink
to let them shrink if there isn't enough space.To prevent vertical overflow, you can
min-height
instead of height
to allow the flex items grow more if necessaryoverflow
different than visible on the flex itemsoverflow
different than visible on the flex containerFor example,
main, aside, article {
margin: 10px;
border: solid 1px #000;
border-bottom: 0;
min-height: 50px; /* min-height instead of height */
}
main {
display: flex;
}
aside {
flex: 0 1 200px; /* Positive flex-shrink */
}
article {
flex: 1 1 auto; /* Positive flex-shrink */
}
_x000D_
<main>
<aside>x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x </aside>
<article>don't let flex item overflow container.... y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y </article>
</main>
_x000D_
There's no difference between list implementations in both of your examples. There's however a difference in a way you can further use variable myList in your code.
When you define your list as:
List myList = new ArrayList();
you can only call methods and reference members that are defined in the List interface. If you define it as:
ArrayList myList = new ArrayList();
you'll be able to invoke ArrayList-specific methods and use ArrayList-specific members in addition to those whose definitions are inherited from List.
Nevertheless, when you call a method of a List interface in the first example, which was implemented in ArrayList, the method from ArrayList will be called (because the List interface doesn't implement any methods).
That's called polymorphism. You can read up on it.
Both Encrypt and Decrypt with AES and DES Algoritham ,This worked for me perfectly GithubLink: Java Code For Encryption and Decryption
package decrypt;
import java.security.Key;
import java.security.NoSuchAlgorithmException;
import javax.crypto.Cipher;
import javax.crypto.KeyGenerator;
import javax.crypto.NoSuchPaddingException;
import javax.crypto.SecretKey;
import javax.crypto.spec.SecretKeySpec;
/* Decrypt encrypted string into plain string with aes and Des algoritham*/
public class Decrypt {
public String decrypt(String str,String k) throws Exception {
// Decode base64 to get bytes
Cipher dcipher = Cipher.getInstance("AES");
Key aesKey = new SecretKeySpec(k.getBytes(), "AES");
dcipher.init(dcipher.DECRYPT_MODE, aesKey);
//System.out.println(aesKey);
byte[] dec = new sun.misc.BASE64Decoder().decodeBuffer(str);
byte[] utf8 = dcipher.doFinal(dec);
//System.out.println(utf8);
// Decode using utf-8
return new String(utf8, "UTF8");
}
public String encrypt(String str,String k) throws Exception {
Cipher ecipher = Cipher.getInstance("AES");
Key aeskey = new SecretKeySpec(k.getBytes(),"AES");
byte[] utf8 = str.getBytes("UTF8");
ecipher.init(ecipher.ENCRYPT_MODE, aeskey );
byte[] enc = ecipher.doFinal(utf8);
return new sun.misc.BASE64Encoder().encode(enc);
}
public String encrypt(String str,String k,String Algo) throws Exception {
Cipher ecipher = Cipher.getInstance(Algo);
Key aeskey = new SecretKeySpec(k.getBytes(),Algo);
byte[] utf8 = str.getBytes("UTF8");
ecipher.init(ecipher.ENCRYPT_MODE, aeskey );
byte[] enc = ecipher.doFinal(utf8);
return new sun.misc.BASE64Encoder().encode(enc);
}
public String decrypt(String str,String k,String Algo) throws Exception {
// Decode base64 to get bytes
Cipher dcipher = Cipher.getInstance(Algo);
Key aesKey = new SecretKeySpec(k.getBytes(), Algo);
dcipher.init(dcipher.DECRYPT_MODE, aesKey);
//System.out.println(aesKey);
byte[] dec = new sun.misc.BASE64Decoder().decodeBuffer(str);
byte[] utf8 = dcipher.doFinal(dec);
//System.out.println(utf8);
// Decode using utf-8
return new String(utf8, "UTF8");
}
public static void main(String args []) throws Exception
{
String original = "rakesh";
String data = "CfPcX0G+e7TLKKMyyvrvrQ==";
String k = "qertyuiopasdfghw"; //AES key length must be 16
String k1 = "qertyuio"; // DES key length must be 8
String data1 = "rakesh";
String data2 = "nAtvNq7uHKE=";
String Algo= "DES";
String Algo1= "AES";
Decrypt decrypter = new Decrypt();
System.out.println("Original String: " + original);
System.out.println("encrypted String in DES: " + decrypter.encrypt(data1,
k1,Algo));
System.out.println("Decrypted String in DES: " + decrypter.decrypt(data2,
k1,Algo));
System.out.println("encrypted String in AES: " + decrypter.encrypt(data1,
k,Algo1));
System.out.println("Decrypted String in AES: " + decrypter.decrypt(data,
k,Algo1));
}
}
Pointers to pointers also come in handy as "handles" to memory where you want to pass around a "handle" between functions to re-locatable memory. That basically means that the function can change the memory that is being pointed to by the pointer inside the handle variable, and every function or object that is using the handle will properly point to the newly relocated (or allocated) memory. Libraries like to-do this with "opaque" data-types, that is data-types were you don't have to worry about what they're doing with the memory being pointed do, you simply pass around the "handle" between the functions of the library to perform some operations on that memory ... the library functions can be allocating and de-allocating the memory under-the-hood without you having to explicitly worry about the process of memory management or where the handle is pointing.
For instance:
#include <stdlib.h>
typedef unsigned char** handle_type;
//some data_structure that the library functions would work with
typedef struct
{
int data_a;
int data_b;
int data_c;
} LIB_OBJECT;
handle_type lib_create_handle()
{
//initialize the handle with some memory that points to and array of 10 LIB_OBJECTs
handle_type handle = malloc(sizeof(handle_type));
*handle = malloc(sizeof(LIB_OBJECT) * 10);
return handle;
}
void lib_func_a(handle_type handle) { /*does something with array of LIB_OBJECTs*/ }
void lib_func_b(handle_type handle)
{
//does something that takes input LIB_OBJECTs and makes more of them, so has to
//reallocate memory for the new objects that will be created
//first re-allocate the memory somewhere else with more slots, but don't destroy the
//currently allocated slots
*handle = realloc(*handle, sizeof(LIB_OBJECT) * 20);
//...do some operation on the new memory and return
}
void lib_func_c(handle_type handle) { /*does something else to array of LIB_OBJECTs*/ }
void lib_free_handle(handle_type handle)
{
free(*handle);
free(handle);
}
int main()
{
//create a "handle" to some memory that the library functions can use
handle_type my_handle = lib_create_handle();
//do something with that memory
lib_func_a(my_handle);
//do something else with the handle that will make it point somewhere else
//but that's invisible to us from the standpoint of the calling the function and
//working with the handle
lib_func_b(my_handle);
//do something with new memory chunk, but you don't have to think about the fact
//that the memory has moved under the hood ... it's still pointed to by the "handle"
lib_func_c(my_handle);
//deallocate the handle
lib_free_handle(my_handle);
return 0;
}
Hope this helps,
Jason
event.stopPropagation() allows other handlers on the same element to be executed, while event.stopImmediatePropagation() prevents every event from running. For example, see below jQuery code block.
$("p").click(function(event)
{ event.stopImmediatePropagation();
});
$("p").click(function(event)
{ // This function won't be executed
$(this).css("color", "#fff7e3");
});
If event.stopPropagation was used in previous example, then the next click event on p element which changes the css will fire, but in case event.stopImmediatePropagation(), the next p click event will not fire.
Here is a more generic solution for any given weekday. Working demo on jsfiddle
var myIsoWeekDay = 2; // say our weeks start on tuesday, for monday you would type 1, etc.
var startOfPeriod = moment("2013-06-23T00:00:00"),
// how many days do we have to substract?
var daysToSubtract = moment(startOfPeriod).isoWeekday() >= myIsoWeekDay ?
moment(startOfPeriod).isoWeekday() - myIsoWeekDay :
7 + moment(startOfPeriod).isoWeekday() - myIsoWeekDay;
// subtract days from start of period
var begin = moment(startOfPeriod).subtract('d', daysToSubtract);
There can't be aggregate functions (Ex. COUNT, MAX, etc.) in A WHERE clause. Hence we use the HAVING clause instead. Therefore the whole query would be similar to this:
SELECT column_name, aggregate_function(column_name)
FROM table_name
WHERE column_name operator value
GROUP BY column_name
HAVING aggregate_function(column_name) operator value;
Just a heads up, if you supply a body in your DELETE request and are using a google cloud HTTPS load balancer, it will reject your request with a 400 error. I was banging my head against a wall and came to found out that Google, for whatever reason, thinks a DELETE request with a body is a malformed request.
I was looking for an example that had default kwargs using type annotation:
def test_var_kwarg(a: str, b: str='B', c: str='', **kwargs) -> str:
return ' '.join([a, b, c, str(kwargs)])
example:
>>> print(test_var_kwarg('A', c='okay'))
A B okay {}
>>> d = {'f': 'F', 'g': 'G'}
>>> print(test_var_kwarg('a', c='c', b='b', **d))
a b c {'f': 'F', 'g': 'G'}
>>> print(test_var_kwarg('a', 'b', 'c'))
a b c {}
Here is a small example how to add a matplotlib grid in Gtk3 with Python 2 (not working in Python 3):
#!/usr/bin/env python
#-*- coding: utf-8 -*-
import gi
gi.require_version('Gtk', '3.0')
from gi.repository import Gtk
from matplotlib.figure import Figure
from matplotlib.backends.backend_gtk3agg import FigureCanvasGTK3Agg as FigureCanvas
win = Gtk.Window()
win.connect("delete-event", Gtk.main_quit)
win.set_title("Embedding in GTK3")
f = Figure(figsize=(1, 1), dpi=100)
ax = f.add_subplot(111)
ax.grid()
canvas = FigureCanvas(f)
canvas.set_size_request(400, 400)
win.add(canvas)
win.show_all()
Gtk.main()
By design adb root
command works in development builds only (i.e. eng
and userdebug
which have ro.debuggable=1
by default). So to enable the adb root
command on your otherwise rooted device just add the ro.debuggable=1
line to one of the following files:
/system/build.prop
/system/default.prop
/data/local.prop
If you want adb shell
to start as root
by default - then add ro.secure=0
as well.
Alternatively you could use modified adbd
binary (which does not check for ro.debuggable
)
From https://android.googlesource.com/platform/system/core/+/master/adb/daemon/main.cpp
#if defined(ALLOW_ADBD_ROOT)
// The properties that affect `adb root` and `adb unroot` are ro.secure and
// ro.debuggable. In this context the names don't make the expected behavior
// particularly obvious.
//
// ro.debuggable:
// Allowed to become root, but not necessarily the default. Set to 1 on
// eng and userdebug builds.
//
// ro.secure:
// Drop privileges by default. Set to 1 on userdebug and user builds.
Are you asking how to control what is visible when the soft keyboard opens? You might want to play with the windowSoftInputMode. See developer docs for more discussion.
The answer depends on which "command-line script" language you are in.
In the old cmd.exe
command prompt or in a .bat
or .cmd
script, you can use the following:
%USERNAME%
- Gets just the username.
%USERDOMAIN%
- Gets the user's domain.
In the PowerShell command prompt or a .ps1
or .psm1
script, you can use the following:
[System.Security.Principal.WindowsIdentity]::GetCurrent().Name
- Gives you the fully qualified username (e.g. Domain\Username). This is also the most secure method because it cannot be overridden by the user like the other $Env
variables below.
$Env:Username
- Gets just the username.
$Env:UserDomain
- Gets the user's domain.
$Env:ComputerName
- Gets the name of the computer.
$result = $mysqli->query($query);
if($result){
perform action
}
this is how i do it, you could also throw an else there with a die...
Why not just use the following.
System.IO.Path.Combine(rootUrl, subPath).Replace(@"\", "/")
In my case, I was exporting a Class and an Enum from the same component file:
mComponent.component.ts
:
export class MyComponentClass{...}
export enum MyEnum{...}
Then, I was trying to use MyEnum
from a child of MyComponentClass
. That was causing the Can't resolve all parameters error.
By moving MyEnum
in a separate folder from MyComponentClass
, that solved my issue!
As Günter Zöchbauer mentioned, this is happening because of a service or component is circularly dependent.
A bit old and different, as I needed to change a certain line in all instances of a particular file name.
Also, Set-Content
was not returning consistent results, so I had to resort to Out-File
.
Code below:
$FileName =''
$OldLine = ''
$NewLine = ''
$Drives = Get-PSDrive -PSProvider FileSystem
foreach ($Drive in $Drives) {
Push-Location $Drive.Root
Get-ChildItem -Filter "$FileName" -Recurse | ForEach {
(Get-Content $_.FullName).Replace($OldLine, $NewLine) | Out-File $_.FullName
}
Pop-Location
}
This is what worked best for me on this PowerShell version:
Major.Minor.Build.Revision
5.1.16299.98
This solution is for Litespeed Server (Apache as well)
Add the following code in .htaccess
RewriteRule .* - [E=noabort:1]
RewriteRule .* - [E=noconntimeout:1]
Note that I am no java programmer, but in .NET and C#, this feature is called contravariance or covariance. I haven't delved into those things yet, since they are new in .NET 4.0, which I'm not using since it's only beta, so I don't know which of the two terms describe your problem, but let me describe the technical issue with this.
Let's assume you were allowed to cast. Note, I say cast, since that's what you said, but there are two operations that could be possible, casting and converting.
Converting would mean that you get a new list object, but you say casting, which means you want to temporarily treat one object as another type.
Here's the problem with that.
What would happen if the following was allowed (note, I'm assuming that before the cast, the list of objects actually only contain Customer objects, otherwise the cast wouldn't work even in this hypothetical version of java):
List<Object> list = getList();
List<Customer> customers = (List<Customer>)list;
list.Insert(0, new someOtherObjectNotACustomer());
Customer c = customers[0];
In this case, this would attempt to treat an object, that isn't a customer, as a customer, and you would get a runtime error at one point, either form inside the list, or from the assignment.
Generics, however, is supposed to give you type-safe data types, like collections, and since they like to throw the word 'guaranteed' around, this sort of cast, with the problems that follow, is not allowed.
In .NET 4.0 (I know, your question was about java), this will be allowed in some very specific cases, where the compiler can guarantee that the operations you do are safe, but in the general sense, this type of cast will not be allowed. The same holds for java, although I'm unsure about any plans to introduce co- and contravariance to the java language.
Hopefully, someone with better java knowledge than me can tell you the specifics for the java future or implementation.
Late at party, but a very simple solution is to use the jpsstat.sh script. It provides a simple live current memory, max memory and cpu use details.
Here is the sample output of script -
===== ====== ======= ======= =====
PID Name CurHeap MaxHeap %_CPU
===== ====== ======= ======= =====
2777 Test3 1.26 1.26 5.8
2582 Test1 2.52 2.52 8.3
2562 Test2 2.52 2.52 6.4
When you reference Range like that it's called an unqualified reference because you don't specifically say which sheet the range is on. Unqualified references are handled by the "_Global" object that determines which object you're referring to and that depends on where your code is.
If you're in a standard module, unqualified Range will refer to Activesheet. If you're in a sheet's class module, unqualified Range will refer to that sheet.
inputTemplateContent is a variable that contains a reference to a range, probably a named range. If you look at the RefersTo property of that named range, it likely points to a sheet other than the Activesheet at the time the code executes.
The best way to fix this is to avoid unqualified Range references by specifying the sheet. Like
With ThisWorkbook.Worksheets("Template")
.Range(inputTemplateHeader).Value = NO_ENTRY
.Range(inputTemplateContent).Value = NO_ENTRY
End With
Adjust the workbook and worksheet references to fit your particular situation.
I had to add both manager-gui and manager-script roles for it to work, in version 9.
After getting the access to MangerApp, while trying to upload .war file, I got the exception
org.apache.tomcat.util.http.fileupload.FileUploadBase$IOFileUploadException
which I was able to solve using the answer of this post
To get access for Host Manager, check this post
If you want your numbers in ascending order you can add them into a set and then sort the set into an ascending list.
s = set()
if number1 not in s:
s.add(number1)
if number2 not in s:
s.add(number2)
...
s = sorted(s) #Now a list in ascending order
Swift version of @onegray's answer
protocol RequestsNavigationPopVerification {
var confirmationTitle: String { get }
var confirmationMessage: String { get }
}
extension RequestsNavigationPopVerification where Self: UIViewController {
var confirmationTitle: String {
return "Go back?"
}
var confirmationMessage: String {
return "Are you sure?"
}
}
final class NavigationController: UINavigationController {
func navigationBar(navigationBar: UINavigationBar, shouldPopItem item: UINavigationItem) -> Bool {
guard let requestsPopConfirm = topViewController as? RequestsNavigationPopVerification else {
popViewControllerAnimated(true)
return true
}
let alertController = UIAlertController(title: requestsPopConfirm.confirmationTitle, message: requestsPopConfirm.confirmationMessage, preferredStyle: .Alert)
alertController.addAction(UIAlertAction(title: "Cancel", style: .Cancel) { _ in
dispatch_async(dispatch_get_main_queue(), {
let dimmed = navigationBar.subviews.flatMap { $0.alpha < 1 ? $0 : nil }
UIView.animateWithDuration(0.25) {
dimmed.forEach { $0.alpha = 1 }
}
})
return
})
alertController.addAction(UIAlertAction(title: "Go back", style: .Default) { _ in
dispatch_async(dispatch_get_main_queue(), {
self.popViewControllerAnimated(true)
})
})
presentViewController(alertController, animated: true, completion: nil)
return false
}
}
Now in any controller, just conform to RequestsNavigationPopVerification
and this behaviour is adopted by default.
Have a look at the limits.h
file in your system it will tell the system specific limits. Or check man limits.h
and go to the "Numerical Limits" section.
Here is a link to an excellent wiki that explains how to put greek symbols in ggplot2. In summary, here is what you do to obtain greek symbols
parse = T
inside geom_text
or annotate
.expression(alpha)
to get greek alpha.labeller = label_parsed
inside facet
.bquote(alpha == .(value))
in legend label.You can see detailed usage of these options in the link
EDIT. The objective of using greek symbols along the tick marks can be achieved as follows
require(ggplot2);
data(tips);
p0 = qplot(sex, data = tips, geom = 'bar');
p1 = p0 + scale_x_discrete(labels = c('Female' = expression(alpha),
'Male' = expression(beta)));
print(p1);
For complete documentation on the various symbols that are available when doing this and how to use them, see ?plotmath
.
They behave the same but toString
also provides a way to convert a number binary, octal, or hexadecimal strings:
Example:
var a = (50274).toString(16) // "c462"
var b = (76).toString(8) // "114"
var c = (7623).toString(36) // "5vr"
var d = (100).toString(2) // "1100100"
I solved this by removing android:replace
tag
GlobalStrings.AddRange(localStrings);
That works.
Documentation: List<T>.AddRange(IEnumerable<T>)
.
To get day number from date is in python
for example:19-12-2020(dd-mm-yyy)order_date we need 19 as output
order['day'] = order['Order_Date'].apply(lambda x: x.day)
There is no problem with displaying HTML code in blade templates.
For test, you can add to routes.php only one route:
Route::get('/', function () {
$data = new stdClass();
$data->page_desc
= '<strong>aaa</strong><em>bbb</em>
<p>New paragaph</p><script>alert("Hello");</script>';
return View::make('hello')->with('content', $data);
}
);
and in hello.blade.php
file:
<!doctype html>
<html lang="en">
<head>
<meta charset="UTF-8">
</head>
<body>
{{ $content->page_desc }}
</body>
</html>
For the following code you will get output as on image
So probably page_desc
in your case is not what you expect. But as you see it can be potential dangerous if someone uses for example '` tag so you should probably in your route before assigning to blade template filter some tags
EDIT
I've also tested it with putting the same code into database:
Route::get('/', function () {
$data = User::where('id','=',1)->first();
return View::make('hello')->with('content', $data);
}
);
Output is exactly the same in this case
Edit2
I also don't know if Pages
is your model or it's a vendor model. For example it can have accessor inside:
public function getPageDescAttribute($value)
{
return htmlspecialchars($value);
}
and then when you get page_desc
attribute you will get modified page_desc
with htmlspecialchars
. So if you are sure that data in database is with raw html (not escaped) you should look at this Pages
class
Solution in R (RSelenium): I had a popup dialog (which is dynamically generated) and hence undetectable in the original page source code Here are methods which worked for me:
Method 1: Simulating Pressing keys for Tabs and switching to that modal dialog My current key is focussed on a dropdown button behind the modal dialog boxremDr$sendKeysToActiveElement(list(key = "tab"))
Sys.sleep(5)
remDr$sendKeysToActiveElement(list(key = "enter"))
Sys.sleep(15)
Method 2: Bring focus to the frame(or iframe) if you can locate it
date_filter_frame <- remDr$findElement(using = "tag name", 'iframe')
date_filter_frame$highlightElement()
Sys.sleep(5)
remDr$switchToFrame(date_filter_frame)
Sys.sleep(2)
Now you can search for elements in the frame. Remember to put adequate Sys.sleep in between commands for elements to load properly (just in case)
date_filter_element <- remDr$findElement(using = "xpath", paste0("//*[contains(text(), 'Week to Date')]"))
date_filter_element$highlightElement()
I'm a bit late on the subject but I came across this post as I've just been bitten by that question and finally found a really easy way to get over it, simply use a navbar
with the navbar-fixed-bottom
class enabled. For example:
<div class="navbar navbar-default navbar-fixed-bottom">
<div class="container">
<span class="navbar-text">
Something useful
</span>
</div>
</div>
HTH
Just do:
echo substr($string, 0, -3);
You don't need to use a strlen
call, since, as noted in the substr docs:
If length is given and is negative, then that many characters will be omitted from the end of string
Use the native element.submit()
to circumvent the preventDefault in the jQuery handler, and note that your return statement only returns from the each loop, it does not return from the event handler
$('form').submit(function(e){
e.preventDefault();
var valid = true;
$('[name="atendeename[]"]', this).each(function(index, el){
if ( $(el).val() ) {
var entree = $(el).next('input');
if ( ! entree.val()) {
entree.focus();
valid = false;
}
}
});
if (valid) this.submit();
});
I found it is better to use the command Serial.readString()
to replace the Serial.read()
to obtain the continuous I/O for Arduino.
If you only need the names of the remote repositories (and not any of the other data), a simple git remote
is enough.
$ git remote
iqandreas
octopress
origin
When user clicks on the button, directly inside the XML like that:
<Button
android:id="@+id/button"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="TextButton"
android:onClick="buttonClickFunction"/>
Using the attribute android:onClick
we declare the method name that has to be present on the parent activity. So I have to create this method inside our activity like that:
public void buttonClickFunction(View v)
{
Intent intent = new Intent(getApplicationContext(), Your_Next_Activity.class);
startActivity(intent);
}
You could try turning off the main Activity's ability to save its state (thus making it forget what control had text and what had focus). You will need to have some other way of remembering what your EditText's have and repopulating them onResume(). Launch your sub-Activities with startActivityForResult() and create an onActivityResult() handler in your main Activity that will update the EditText's correctly. This way you can set the proper button you want focused onResume() at the same time you repopulate the EditText's by using a myButton.post(new Runnable(){ run() { myButton.requestFocus(); } });
The View.post() method is useful for setting focus initially because that runnable will be executed after the window is created and things settle down, allowing the focus mechanism to function properly by that time. Trying to set focus during onCreate/Start/Resume() usually has issues, I've found.
Please note this is pseudo-code and non-tested, but it's a possible direction you could try.
Look here.
Basically you have to do bind params:
$sql = "SELECT username FROM users WHERE locationid IN (SELECT locationid FROM locations WHERE countryid=?)";
$this->db->query($sql, '__COUNTRY_NAME__');
But, like Mr.E said, use joins:
$sql = "select username from users inner join locations on users.locationid = locations.locationid where countryid = ?";
$this->db->query($sql, '__COUNTRY_NAME__');
For the sha256 hash in base64, use:
echo -n foo | openssl dgst -binary -sha1 | openssl base64
echo -n foo | openssl dgst -binary -sha1 | openssl base64
C+7Hteo/D9vJXQ3UfzxbwnXaijM=
I find redo.el
extremly handy for doing "normal" undo/redo, and I usually bind it to C-S-z and undo to C-z, like this:
(when (require 'redo nil 'noerror)
(global-set-key (kbd "C-S-z") 'redo))
(global-set-key (kbd "C-z") 'undo)
Just download the file, put it in your lisp-path and paste the above in your .emacs
.
min-height: 100%;
position: relative;
If you are using the batch conversion, in the window click "options" in the "Batch conversion settings-output format" and tick the two boxes "save transparent color" (one under "PNG" and the other under "ICO").
If anybody decides to use replace
, you should try r'\n'
instead '\n'
mystring = mystring.replace(r'\n', ' ').replace(r'\r', '')
During an object's de-serialization, the class responsible for de-serializing an object creates an instance of the serialized class and then proceeds to populate the serialized fields and properties only after acquiring an instance to populate.
You can make your constructor private
or internal
if you want, just so long as it's parameterless.
I was facing the same issue, and it was, as i missed marking my DAO class with Entity annotations. I tried below and error got resolved.
/**
*`enter code here`
*/
@Entity <-- was missing earlier
public class Topic {
@Id
String id;
String name;
String desc;
.
.
.
}
It depends on what you are trying to print. You need a third party pdf printer application or if you are printing data of your own you can use report viewer in visual studio. It can output reports to excel and pdf -files.
I see a couple Swift3 answers so I'll add my own:
public static func daysBetween(start: Date, end: Date) -> Int {
Calendar.current.dateComponents([.day], from: start, to: end).day!
}
The naming feels more Swifty, it's one line, and using the latest dateComponents()
method.
More details on how to set the OnKeyListener, and have it listen for the Done button.
First add OnKeyListener to the implements section of your class. Then add the function defined in the OnKeyListener interface:
/*
* Respond to soft keyboard events, look for the DONE press on the password field.
*/
public boolean onKey(View v, int keyCode, KeyEvent event)
{
if ((event.getAction() == KeyEvent.ACTION_DOWN) &&
(keyCode == KeyEvent.KEYCODE_ENTER))
{
// Done pressed! Do something here.
}
// Returning false allows other listeners to react to the press.
return false;
}
Given an EditText object:
EditText textField = (EditText)findViewById(R.id.MyEditText);
textField.setOnKeyListener(this);
When it comes to the main script it's as simple as:
process.argv[1]
From the Node.js documentation:
process.argv
An array containing the command line arguments. The first element will be 'node', the second element will be the path to the JavaScript file. The next elements will be any additional command line arguments.
If you need to know the path of a module file then use __filename.
Using NAT (the default) this is not possible. Bridged Networking should allow it. If bridged does not work for you (this may be the case when your network adminstration does not allow multiple IP addresses on one physical interface), you could try 'Host-only networking' instead.
For configuration of Host-only here is a quote from the vbox manual(which is pretty good). http://www.virtualbox.org/manual/ch06.html:
For host-only networking, like with internal networking, you may find the DHCP server useful that is built into VirtualBox. This can be enabled to then manage the IP addresses in the host-only network since otherwise you would need to configure all IP addresses statically.
In the VirtualBox graphical user interface, you can configure all these items in the global settings via "File" -> "Settings" -> "Network", which lists all host-only networks which are presently in use. Click on the network name and then on the "Edit" button to the right, and you can modify the adapter and DHCP settings.
Using HTTP Request verb such as GET, POST, DELETE, PUT etc... enables you to build RESTful web applications. Read about it here: http://en.wikipedia.org/wiki/Representational_state_transfer
The easiest way to see benefits from this is to look at this example.
Every MVC framework has a Router/Dispatcher
that maps URL-s to actionControllers.
So URL like this: /blog/article/1
would invoke blogController::articleAction($id);
Now this Router is only aware of the URL or /blog/article/1/
But if that Router would be aware of whole HTTP Request object instead of just URL, he could have access HTTP Request verb (GET, POST, PUT, DELETE...), and many other useful stuff about current HTTP Request.
That would enable you to configure application so it can accept the same URL and map it to different actionControllers depending on the HTTP Request verb.
For example:
if you want to retrive article 1 you can do this:
GET /blog/article/1 HTTP/1.1
but if you want to delete article 1 you will do this:
DELETE /blog/article/1 HTTP/1.1
Notice that both HTTP Requests have the same URI, /blog/article/1, the only difference is the HTTP Request verb. And based on that verb your router can call different actionController. This enables you to build neat URL-s.
Read this two articles, they might help you:
These articles are about Symfony 2 framework, but they can help you to figure out how does HTTP Requests and Responses work.
Hope this helps!
As far as I can tell, at this point it is not possible to set click_action in the console.
While not a strict answer to how to get the click_action set in the console, you can use curl as an alternative:
curl --header "Authorization: key=<YOUR_KEY_GOES_HERE>" --header Content-Type:"application/json" https://fcm.googleapis.com/fcm/send -d "{\"to\":\"/topics/news\",\"notification\": {\"title\": \"Click Action Message\",\"text\": \"Sample message\",\"click_action\":\"OPEN_ACTIVITY_1\"}}"
This is an easy way to test click_action mapping. It requires an intent filter like the one specified in the FCM docs:
<intent-filter>_x000D_
<action android:name="OPEN_ACTIVITY_1" />_x000D_
<category android:name="android.intent.category.DEFAULT" />_x000D_
</intent-filter>
_x000D_
This also makes use of topics to set the audience. In order for this to work you will need to subscribe to a topic called "news".
FirebaseMessaging.getInstance().subscribeToTopic("news");
Even though it takes several hours to see a newly-created topic in the console, you may still send messages to it through the FCM apis.
Also, keep in mind, this will only work if the app is in the background. If it is in the foreground you will need to implement an extension of FirebaseMessagingService. In the onMessageReceived method, you will need to manually navigate to your click_action target:
@Override
public void onMessageReceived(RemoteMessage remoteMessage) {
//This will give you the topic string from curl request (/topics/news)
Log.d(TAG, "From: " + remoteMessage.getFrom());
//This will give you the Text property in the curl request(Sample Message):
Log.d(TAG, "Notification Message Body: " + remoteMessage.getNotification().getBody());
//This is where you get your click_action
Log.d(TAG, "Notification Click Action: " + remoteMessage.getNotification().getClickAction());
//put code here to navigate based on click_action
}
As I said, at this time I cannot find a way to access notification payload properties through the console, but I thought this work around might be helpful.
It could be something like:
var qry = from t in db.Lasttraces
group t by t.AccountId into g
orderby t.Date
select new { g.AccountId, Date = g.Max(e => e.Date) };
// example of goto in javascript:
var i, j;
loop_1:
for (i = 0; i < 3; i++) { //The first for statement is labeled "loop_1"
loop_2:
for (j = 0; j < 3; j++) { //The second for statement is labeled "loop_2"
if (i === 1 && j === 1) {
continue loop_1;
}
console.log('i = ' + i + ', j = ' + j);
}
}
How are you opening the rendered Markdown?
If you host it over HTTP, i.e. you access it via http://
or https://
, most modern browsers will refuse to open local links, e.g. with file://
. This is a security feature:
For security purposes, Mozilla applications block links to local files (and directories) from remote files. This includes linking to files on your hard drive, on mapped network drives, and accessible via Uniform Naming Convention (UNC) paths. This prevents a number of unpleasant possibilities, including:
- Allowing sites to detect your operating system by checking default installation paths
- Allowing sites to exploit system vulnerabilities (e.g.,
C:\con\con
in Windows 95/98)- Allowing sites to detect browser preferences or read sensitive data
There are some workarounds listed on that page, but my recommendation is to avoid doing this if you can.
I had a different issue that brought me to this question, which will probably be more common than the overrelease issue in the accepted answer.
Root cause was our completion block being called twice due to bad if/else fallthrough in the network handler, leading to two calls of dispatch_group_leave
for every one call to dispatch_group_enter
.
dispatch_group_enter(group);
[self badMethodThatCallsMULTIPLECompletions:^(NSString *completion) {
// this block is called multiple times
// one `enter` but multiple `leave`
dispatch_group_leave(group);
}];
count
Upon the EXC_BAD_INSTRUCTION
, you should still have access to your dispatch_group in the debugger. DispatchGroup: check how many "entered"
Print out the dispatch_group and you'll see:
<OS_dispatch_group: group[0x60800008bf40] = { xrefcnt = 0x2, refcnt = 0x1, port = 0x0, count = -1, waiters = 0 }>
When you see count = -1
it indicates that you've over-left the dispatch_group. Be sure to dispatch_enter
and dispatch_leave
the group in matched pairs.
There is another, a clear one (IMO) solution to this There is a parameter called "staleFile" that uses as a flag to not generate stuff again. Simply alter it in each execution.
These are the vendor-prefixed properties offered by the relevant rendering engines (-webkit
for Chrome, Safari; -moz
for Firefox, -o
for Opera, -ms
for Internet Explorer). Typically they're used to implement new, or proprietary CSS features, prior to final clarification/definition by the W3.
This allows properties to be set specific to each individual browser/rendering engine in order for inconsistencies between implementations to be safely accounted for. The prefixes will, over time, be removed (at least in theory) as the unprefixed, the final version, of the property is implemented in that browser.
To that end it's usually considered good practice to specify the vendor-prefixed version first and then the non-prefixed version, in order that the non-prefixed property will override the vendor-prefixed property-settings once it's implemented; for example:
.elementClass {
-moz-border-radius: 2em;
-ms-border-radius: 2em;
-o-border-radius: 2em;
-webkit-border-radius: 2em;
border-radius: 2em;
}
Specifically, to address the CSS in your question, the lines you quote:
-webkit-column-count: 3;
-webkit-column-gap: 10px;
-webkit-column-fill: auto;
-moz-column-count: 3;
-moz-column-gap: 10px;
-moz-column-fill: auto;
Specify the column-count
, column-gap
and column-fill
properties for Webkit browsers and Firefox.
References:
For the examples you stated I'd use the following:
activate_login
POST /users/1/activation
deactivate_login
DELETE /users/1/activation
change_password
PUT /passwords
(this assumes the user is authenticated)
add_credit
POST /credits
(this assumes the user is authenticated)
For errors you'd return the error in the body in the format that you got the request in, so if you receive:
DELETE /users/1.xml
You'd send the response back in XML, the same would be true for JSON etc...
For authentication you should use http authentication.
No 2 looks fine.
For a table with only 4 columns it shouldn't be a problem, even with a good few million rows. Of course this can depend on what database you are using. If its something like SQL Server then it would be no problem.
You'd probably want to create an index on the QuestionID field, on the tblAnswer table.
Of course, you need to specify what Database you are using as well as estimated volumes.
Also check this answer from here: Cannot manually edit applicationhost.config
The answer is simple, if not that obvious: win2008 is 64bit, notepad++ is 32bit. When you navigate to Windows\System32\inetsrv\config using explorer you are using a 64bit program to find the file. When you open the file using using notepad++ you are trying to open it using a 32bit program. The confusion occurs because, rather than telling you that this is what you are doing, windows allows you to open the file but when you save it the file's path is transparently mapped to Windows\SysWOW64\inetsrv\Config.
So in practice what happens is you open applicationhost.config using notepad++, make a change, save the file; but rather than overwriting the original you are saving a 32bit copy of it in Windows\SysWOW64\inetsrv\Config, therefore you are not making changes to the version that is actually used by IIS. If you navigate to the Windows\SysWOW64\inetsrv\Config you will find the file you just saved.
How to get around this? Simple - use a 64bit text editor, such as the normal notepad that ships with windows.
The following (evil) code runs more than TWICE as fast as the nmap method
for i in {1..254} ;do (ping 192.168.1.$i -c 1 -w 5 >/dev/null && echo "192.168.1.$i" &) ;done
takes around 10 seconds, where the standard nmap
nmap -sP 192.168.1.1-254
takes 25 seconds...
Do this
<% for(int i = 0; i < allFestivals.size(); i+=1) { %>
<tr>
<td><%=allFestivals.get(i).getFestivalName()%></td>
</tr>
<% } %>
Better way is to use c:foreach see link jstl for each
In your code you are querying for the payment
element in default namespace, but in the XML response it is declared as in http://apilistener.envoyservices.com
namespace.
So, you are missing a namespace declaration:
$xml->registerXPathNamespace('envoy', 'http://apilistener.envoyservices.com');
Now you can use the envoy
namespace prefix in your xpath query:
xpath('//envoy:payment')
The full code would be:
$xml = simplexml_load_string($soap_response);
$xml->registerXPathNamespace('envoy', 'http://apilistener.envoyservices.com');
foreach ($xml->xpath('//envoy:payment') as $item)
{
print_r($item);
}
Note: I removed the soap
namespace declaration as you do not seem to be using it (it is only useful if you would use the namespace prefix in you xpath queries).
You can use System.load()
to provide an absolute path which is what you want, rather than a file in the standard library folder for the respective OS.
If you want native applications that already exist, use System.loadLibrary(String filename)
. If you want to provide your own you're probably better with load().
You should also be able to use loadLibrary
with the java.library.path
set correctly. See ClassLoader.java
for implementation source showing both paths being checked (OpenJDK)
There's a I/O library available, but if it's available depends on your scripting host (assuming you've embedded lua somewhere). It's available, if you're using the command line version. The complete I/O model is most likely what you're looking for.
Also it may cause some warnigs in logs like a Cglib2AopProxy Unable to proxy method. And many other reasons for this are described here Why always have single implementaion interfaces in service and dao layers?
In Swift 3.0 (this is a little bit faster and safer than the accepted answer) :
extension String {
func firstCharacterUpperCase() -> String {
if let firstCharacter = characters.first {
return replacingCharacters(in: startIndex..<index(after: startIndex), with: String(firstCharacter).uppercased())
}
return ""
}
}
nameOfString.capitalized won't work, it will capitalize every words in the sentence
Here is a bare bones version:
Let's say that you have a date in Cell A1 in the format you described. For example: 19760210
.
Then this formula will give you the date you want:
=DATE(LEFT(A1,4),MID(A1,5,2),RIGHT(A1,2)).
On my system (Excel 2010) it works with strings or floats.
This may be off topic, but for those who are struggling on how to exactly change also the font of the button text (that was my case and Skatephone's answer helped me) here's how I did it (if you made buttons ind design mode):
First we need to have the button's string name "converted" (it's a foul way to explain, but straightforward) into java from the xml, and so we paste the aforementioned code into our MainActivity.java
IMPORTANT! place the code under the OnCreate method!
import android.widget.RemoteViews;
RemoteViews remoteViews = new RemoteViews(getPackageName(), R.layout.my_layout);
remoteViews.setTextViewText(R.id.Counter, "Set button text here");
Keep in mind:
my_layout
has to be substituted with the xml file where your buttons are
Counter
has to be substituted with the id name of your button ("@+id/ButtonName"
)
if you want to change the button text just insert the text in place of "Set button text here"
here comes the part where you change the font:
Now that you "converted" from xml to java, you can set a Typeface method for TextView. Paste the following code exactly under the previous one just described above
TextView txt = (TextView) findViewById(R.id.text_your_text_view_id);
Typeface font = Typeface.createFromAsset(getAssets(), "fonts/MyFontName.ttf");
txt.setTypeface(font);
where in place of text_your_text_view_id
you put your button's id name (like as previous code) and in place of MyFontName.ttf
you put your desired font
WARNING! This assumes you already put your desired font into the assets/font folder. e.g. assets/fonts/MyFontName.ttf
Python comes with numerous ways of formatting strings:
New style .format()
, which supports a rich formatting mini-language:
>>> temperature = 10
>>> print("the furnace is now {} degrees!".format(temperature))
the furnace is now 10 degrees!
Old style %
format specifier:
>>> print("the furnace is now %d degrees!" % temperature)
the furnace is now 10 degrees!
In Py 3.6 using the new f""
format strings:
>>> print(f"the furnace is now {temperature} degrees!")
the furnace is now 10 degrees!
Or using print()
s default sep
arator:
>>> print("the furnace is now", temperature, "degrees!")
the furnace is now 10 degrees!
And least effectively, construct a new string by casting it to a str()
and concatenating:
>>> print("the furnace is now " + str(temperature) + " degrees!")
the furnace is now 10 degrees!
Or join()
ing it:
>>> print(' '.join(["the furnace is now", str(temperature), "degrees!"]))
the furnace is now 10 degrees!
Use:
docker inspect -f "{{.Path}} {{.Args}} ({{.Id}})" $(docker ps -a -q)
That will display the command path and arguments, similar to docker ps
.
Best source of information for all of your DOM woes
http://www.w3.org/TR/dom/#nodes
"Objects implementing the Document, DocumentFragment, DocumentType, Element, Text, ProcessingInstruction, or Comment interface (simply called nodes) participate in a tree."
http://www.w3.org/TR/dom/#element
"Element nodes are simply known as elements."
As explained in "Deleting your master branch" by Matthew Brett, you need to change your GitHub repo default branch.
You need to go to the GitHub page for your forked repository, and click on the “Settings” button.
Click on the "Branches" tab on the left hand side. There’s a “Default branch” dropdown list near the top of the screen.
From there, select placeholder (where placeholder is the dummy name for your new default branch).
Confirm that you want to change your default branch.
Now you can do (from the command line):
git push origin :master
Or, since 2012, you can delete that same branch directly on GitHub:
That was announced in Sept. 2013, a year after I initially wrote that answer.
For small changes like documentation fixes, typos, or if you’re just a walking software compiler, you can get a lot done in your browser without needing to clone the entire repository to your computer.
Note: for BitBucket, Tum reports in the comments:
About the same for Bitbucket
Repo -> Settings -> Repository details -> Main branch
$("#your-table-id").empty();
That's as fast as you get.
@Josh Lindsey already answered perfectly fine. But I want to add some information since I often use ssh.
Therefore just change:
git remote add origin [email protected]:/path/to/my_project.git
to:
git remote add origin ssh://[email protected]/path/to/my_project
Note that the colon between domain and path isn't there anymore.
Use .children
instead:
from bs4 import NavigableString, Comment
print ''.join(unicode(child) for child in hit.children
if isinstance(child, NavigableString) and not isinstance(child, Comment))
Yes, this is a bit of a dance.
Output:
>>> for hit in soup.findAll(attrs={'class' : 'MYCLASS'}):
... print ''.join(unicode(child) for child in hit.children
... if isinstance(child, NavigableString) and not isinstance(child, Comment))
...
THIS IS MY TEXT
The scaling on your example figure is a bit strange but you can force it by plotting the index of each x-value and then setting the ticks to the data points:
import matplotlib.pyplot as plt
x = [0.00001,0.001,0.01,0.1,0.5,1,5]
# create an index for each tick position
xi = list(range(len(x)))
y = [0.945,0.885,0.893,0.9,0.996,1.25,1.19]
plt.ylim(0.8,1.4)
# plot the index for the x-values
plt.plot(xi, y, marker='o', linestyle='--', color='r', label='Square')
plt.xlabel('x')
plt.ylabel('y')
plt.xticks(xi, x)
plt.title('compare')
plt.legend()
plt.show()
My issue was updating the search parameters like so $location.search('param', key);
you can read more about it here
Vanilla JS:
var checkboxes = document.getElementsByClassName('activityCheckbox'); // puts all your checkboxes in a variable
function activitiesReset() {
var checkboxesChecked = function () { // if a checkbox is checked, function ends and returns true. If all checkboxes have been iterated through (which means they are all unchecked), returns false.
for (var i = 0; i < checkboxes.length; i++) {
if (checkboxes[i].checked) {
return true;
}
}
return false;
}
error[2].style.display = 'none'; // an array item specific to my project - it's a red label which says 'Please check a checkbox!'. Here its display is set to none, so the initial non-error label is visible instead.
if (submitCounter > 0 && checkboxesChecked() === false) { // if a form submit has been attempted, and if all checkboxes are unchecked
error[2].style.display = 'block'; // red error label is now visible.
}
}
for (var i=0; i<checkboxes.length; i++) { // whenever a checkbox is checked or unchecked, activitiesReset runs.
checkboxes[i].addEventListener('change', activitiesReset);
}
Explanation:
Once a form submit has been attempted, this will update your checkbox section's label to notify the user to check a checkbox if he/she hasn't yet. If no checkboxes are checked, a hidden 'error' label is revealed prompting the user to 'Please check a checkbox!'. If the user checks at least one checkbox, the red label is instantaneously hidden again, revealing the original label. If the user again un-checks all checkboxes, the red label returns in real-time. This is made possible by JavaScript's onchange
event (written as .addEventListener('change', function(){});
However, I might not be taking the best approach, but this is how I have created some Switch
like UIs in few of my apps.
Here is the code -
<RadioGroup
android:checkedButton="@+id/offer"
android:id="@+id/toggle"
android:layout_width="match_parent"
android:layout_height="30dp"
android:layout_marginBottom="@dimen/margin_medium"
android:layout_marginLeft="50dp"
android:layout_marginRight="50dp"
android:layout_marginTop="@dimen/margin_medium"
android:background="@drawable/pink_out_line"
android:orientation="horizontal">
<RadioButton
android:layout_marginTop="1dp"
android:layout_marginBottom="1dp"
android:layout_marginLeft="1dp"
android:id="@+id/search"
android:background="@drawable/toggle_widget_background"
android:layout_width="0dp"
android:layout_height="match_parent"
android:layout_weight="1"
android:button="@null"
android:gravity="center"
android:text="Search"
android:textColor="@color/white" />
<RadioButton
android:layout_marginRight="1dp"
android:layout_marginTop="1dp"
android:layout_marginBottom="1dp"
android:id="@+id/offer"
android:layout_width="0dp"
android:layout_height="match_parent"
android:layout_weight="1"
android:background="@drawable/toggle_widget_background"
android:button="@null"
android:gravity="center"
android:text="Offers"
android:textColor="@color/white" />
</RadioGroup>
pink_out_line.xml
<shape xmlns:android="http://schemas.android.com/apk/res/android"
android:shape="rectangle">
<corners android:radius="2dp" />
<solid android:color="#80000000" />
<stroke
android:width="1dp"
android:color="@color/pink" />
</shape>
toggle_widget_background.xml
<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
<item android:drawable="@color/pink" android:state_checked="true" />
<item android:drawable="@color/dark_pink" android:state_pressed="true" />
<item android:drawable="@color/transparent" />
</selector>
alter pluggable database orclpdb open;`
worked for me.
orclpdb
is the name of pluggable database which may be different based on the individual.
A SOAP request is an XML file consisting of the parameters you are sending to the server.
The SOAP response is equally an XML file, but now with everything the service wants to give you.
Basically the WSDL is a XML file that explains the structure of those two XML.
To implement simple SOAP clients in Java, you can use the SAAJ framework (it is shipped with JSE 1.6 and above):
SOAP with Attachments API for Java (SAAJ) is mainly used for dealing directly with SOAP Request/Response messages which happens behind the scenes in any Web Service API. It allows the developers to directly send and receive soap messages instead of using JAX-WS.
See below a working example (run it!) of a SOAP web service call using SAAJ. It calls this web service.
import javax.xml.soap.*;
public class SOAPClientSAAJ {
// SAAJ - SOAP Client Testing
public static void main(String args[]) {
/*
The example below requests from the Web Service at:
http://www.webservicex.net/uszip.asmx?op=GetInfoByCity
To call other WS, change the parameters below, which are:
- the SOAP Endpoint URL (that is, where the service is responding from)
- the SOAP Action
Also change the contents of the method createSoapEnvelope() in this class. It constructs
the inner part of the SOAP envelope that is actually sent.
*/
String soapEndpointUrl = "http://www.webservicex.net/uszip.asmx";
String soapAction = "http://www.webserviceX.NET/GetInfoByCity";
callSoapWebService(soapEndpointUrl, soapAction);
}
private static void createSoapEnvelope(SOAPMessage soapMessage) throws SOAPException {
SOAPPart soapPart = soapMessage.getSOAPPart();
String myNamespace = "myNamespace";
String myNamespaceURI = "http://www.webserviceX.NET";
// SOAP Envelope
SOAPEnvelope envelope = soapPart.getEnvelope();
envelope.addNamespaceDeclaration(myNamespace, myNamespaceURI);
/*
Constructed SOAP Request Message:
<SOAP-ENV:Envelope xmlns:SOAP-ENV="http://schemas.xmlsoap.org/soap/envelope/" xmlns:myNamespace="http://www.webserviceX.NET">
<SOAP-ENV:Header/>
<SOAP-ENV:Body>
<myNamespace:GetInfoByCity>
<myNamespace:USCity>New York</myNamespace:USCity>
</myNamespace:GetInfoByCity>
</SOAP-ENV:Body>
</SOAP-ENV:Envelope>
*/
// SOAP Body
SOAPBody soapBody = envelope.getBody();
SOAPElement soapBodyElem = soapBody.addChildElement("GetInfoByCity", myNamespace);
SOAPElement soapBodyElem1 = soapBodyElem.addChildElement("USCity", myNamespace);
soapBodyElem1.addTextNode("New York");
}
private static void callSoapWebService(String soapEndpointUrl, String soapAction) {
try {
// Create SOAP Connection
SOAPConnectionFactory soapConnectionFactory = SOAPConnectionFactory.newInstance();
SOAPConnection soapConnection = soapConnectionFactory.createConnection();
// Send SOAP Message to SOAP Server
SOAPMessage soapResponse = soapConnection.call(createSOAPRequest(soapAction), soapEndpointUrl);
// Print the SOAP Response
System.out.println("Response SOAP Message:");
soapResponse.writeTo(System.out);
System.out.println();
soapConnection.close();
} catch (Exception e) {
System.err.println("\nError occurred while sending SOAP Request to Server!\nMake sure you have the correct endpoint URL and SOAPAction!\n");
e.printStackTrace();
}
}
private static SOAPMessage createSOAPRequest(String soapAction) throws Exception {
MessageFactory messageFactory = MessageFactory.newInstance();
SOAPMessage soapMessage = messageFactory.createMessage();
createSoapEnvelope(soapMessage);
MimeHeaders headers = soapMessage.getMimeHeaders();
headers.addHeader("SOAPAction", soapAction);
soapMessage.saveChanges();
/* Print the request message, just for debugging purposes */
System.out.println("Request SOAP Message:");
soapMessage.writeTo(System.out);
System.out.println("\n");
return soapMessage;
}
}
Sounds like you're just trying to do a classic two-column lookup. http://www.dailydoseofexcel.com/archives/2009/04/21/vlookup-on-two-columns/
Tons of solutions for this, most simple is probably the following (which doesn't require an array formula):
=SUMPRODUCT((Lookup!A:A=Param!A1)*(Lookup!B:B=Param!B1)*(Lookup!C:C))
To translate your specific example, you would use:
=SUMPRODUCT((A1:A3=A2)*(B1:B3="B")*(C1:C3))
First check with dmesg | grep tty
if system recognize your adapter.
Then try to run minicom with sudo minicom -s
, go to "Serial port setup" and change the first line to /dev/ttyUSB0
.
Don't forget to save config as default with "Save setup as dfl". It works for me on Ubuntu 11.04 on VirtualBox.
html {
overflow-x: hidden;
margin-right: calc(-1 * (100vw - 100%));
}
Example. Click "change min-height" button.
With calc(100vw - 100%)
we can calculate the width of the scrollbar (and if it is not displayed, it will be 0). Idea: using negative margin-right, we can increase the width of <html>
to this width. You will see a horizontal scroll bar — it should be hidden using overflow-x: hidden
.
In vanilla JS:
function keydownFunc(event) {
var x = event.keyCode;
if (x == 13) {
try{
var nextInput = event.target.parentElement.nextElementSibling.childNodes[0];
nextInput.focus();
}catch (error){
console.log(error)
}
}
For python, you need to use
Class pg8000.types.Bytea (str) Bytea is a str-derived class that is mapped to a PostgreSQL byte array.
or
Pg8000.Binary (value) Construct an object holding binary data.
I"m not sure how Arve's solution would work in a custom Dialog with builder where the view is inflated via a LayoutInflator.
The solution should be to insert the the ContextThemeWrapper in the inflator through cloneInContext()
:
View sensorView = LayoutInflater.from(context).cloneInContext(
new ContextThemeWrapper(context, R.style.AppTheme_DialogLight)
).inflate(R.layout.dialog_fingerprint, null);
My "API Server" is an PHP Application so to solve this problem I found the below solution to work:
Place the lines in index.php
header('Access-Control-Allow-Origin: *');
header('Access-Control-Allow-Methods: GET, POST, PATCH, PUT, DELETE, OPTIONS');
header('Access-Control-Allow-Headers: Origin, Content-Type, X-Auth-Token');
Can't we do waitfor /T 180
?
waitfor /T 180 pause
will result in "ERROR: Timed out waiting for 'pause'."
waitfor /T 180 pause >nul
will sweep that "error" under the rug
The waitfor
command should be there in Windows OS after Win95
In the past I've downloaded a executable named sleep
that will work on the command line after you put it in your path.
For example: sleep shutdown -r -f /m \\yourmachine
although shutdown now has -t option built in
If you need to pass data from one controller to another you must pass data by route values.Because both are different request.if you send data from one page to another then you have to user query string(same as route values).
But you can do one trick :
In your calling action call the called action as a simple method :
public class ServerController : Controller
{
[HttpPost]
public ActionResult ApplicationPoolsUpdate(ServiceViewModel viewModel)
{
XDocument updatedResultsDocument = myService.UpdateApplicationPools();
ApplicationPoolController pool=new ApplicationPoolController(); //make an object of ApplicationPoolController class.
return pool.UpdateConfirmation(updatedResultsDocument); // call the ActionMethod you want as a simple method and pass the model as an argument.
// Redirect to ApplicationPool controller and pass
// updatedResultsDocument to be used in UpdateConfirmation action method
}
}
First of all you should know the difference between a virtual and abstract method.
You can try to set origins
option on the server side to allow cross-origin requests:
io.set('origins', 'http://yourdomain.com:80');
Here http://yourdomain.com:80
is the origin you want to allow requests from.
You can read more about origins
format here
In order to completely remove pip, I believe you have to delete its files from all Python versions on your computer. For me, they are here:
cd /Library/Frameworks/Python.framework/Versions/Current/bin/
cd /Library/Frameworks/Python.framework/Versions/3.3/bin/
You may need to remove the files or the directories located at these file-paths (and more, depending on the number of versions of Python you have installed).
Edit: to find all versions of pip on your machine, use:
find / -name pip 2>/dev/null
, which starts at its highest level (hence the /
) and hides all error messages (that's what 2>/dev/null
does). This is my output:
$ find / -name pip 2>/dev/null
/Library/Frameworks/Python.framework/Versions/2.7/bin/pip
/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/pip
/Library/Frameworks/Python.framework/Versions/3.3/bin/pip
/Library/Frameworks/Python.framework/Versions/3.3/lib/python3.3/site-packages/pip
/Library/Frameworks/Python.framework/Versions/3.4/lib/python3.4/site-packages/pip
/Library/Frameworks/Python.framework/Versions/7.1/bin/pip
/Library/Frameworks/Python.framework/Versions/7.1/lib/python2.7/site-packages/pip-1.4.1-py2.7.egg/pip
I tested both requests-futures and grequests. Grequests is faster but brings monkey patching and additional problems with dependencies. requests-futures is several times slower than grequests. I decided to write my own and simply wrapped requests into ThreadPoolExecutor and it was almost as fast as grequests, but without external dependencies.
import requests
import concurrent.futures
def get_urls():
return ["url1","url2"]
def load_url(url, timeout):
return requests.get(url, timeout = timeout)
with concurrent.futures.ThreadPoolExecutor(max_workers=20) as executor:
future_to_url = {executor.submit(load_url, url, 10): url for url in get_urls()}
for future in concurrent.futures.as_completed(future_to_url):
url = future_to_url[future]
try:
data = future.result()
except Exception as exc:
resp_err = resp_err + 1
else:
resp_ok = resp_ok + 1
You just have to read the laravel installation page:
composer global require "laravel/installer"
Inside your htdocs or www directory, use either:
laravel new appName
(this can lead to an error on windows computers while using latest Laravel (1.3.2)) or:
composer create-project --prefer-dist laravel/laravel appName
(this works also on windows) to create a project called "appName".
To use "php artisan xyz" you have to be inside your project root! as artisan is a file php is going to use... Simple as that ;)
It sounds like you want the object parameter to be optional, and also each of the properties in the object to be optional. In the example, as provided, overload syntax isn't needed. I wanted to point out some bad practices in some of the answers here. Granted, it's not the smallest possible expression of essentially writing box = { x: 0, y: 87, width: 4, height: 0 }
, but this provides all the code hinting niceties you could possibly want from the class as described. This example allows you to call a function with one, some, all, or none of the parameters and still get default values.
/** @class */
class Box {
public x?: number;
public y?: number;
public height?: number;
public width?: number;
constructor(params: Box = {} as Box) {
// Define the properties of the incoming `params` object here.
// Setting a default value with the `= 0` syntax is optional for each parameter
let {
x = 0,
y = 0,
height = 1,
width = 1
} = params;
// If needed, make the parameters publicly accessible
// on the class ex.: 'this.var = var'.
/** Use jsdoc comments here for inline ide auto-documentation */
this.x = x;
this.y = y;
this.height = height;
this.width = width;
}
}
Need to add methods? A verbose but more extendable alternative:
The Box
class above can work double-duty as the interface since they are identical. If you choose to modify the above class, you will need to define and reference a new interface for the incoming parameters object since the Box
class no longer would look exactly like the incoming parameters. Notice where the question marks (?:
) denoting optional properties move in this case. Since we're setting default values within the class, they are guaranteed to be present, yet they are optional within the incoming parameters object:
interface BoxParams {
x?: number;
// Add Parameters ...
}
class Box {
public x: number;
// Copy Parameters ...
constructor(params: BoxParams = {} as BoxParams) {
let { x = 0 } = params;
this.x = x;
}
doSomething = () => {
return this.x + this.x;
}
}
Whichever way you choose to define your class, this technique offers the guardrails of type safety, yet the flexibility write any of these:
const box1 = new Box();
const box2 = new Box({});
const box3 = new Box({x:0});
const box4 = new Box({x:0, height:10});
const box5 = new Box({x:0, y:87,width:4,height:0});
// Correctly reports error in TypeScript, and in js, box6.z is undefined
const box6 = new Box({z:0});
Compiled, you see how the default settings are only used if an optional value is undefined; it avoids the pitfalls of a widely used (but error-prone) fallback syntax of var = isOptional || default;
by checking against void 0
, which is shorthand for undefined
:
var Box = (function () {
function Box(params) {
if (params === void 0) { params = {}; }
var _a = params.x, x = _a === void 0 ? 0 : _a, _b = params.y, y = _b === void 0 ? 0 : _b, _c = params.height, height = _c === void 0 ? 1 : _c, _d = params.width, width = _d === void 0 ? 1 : _d;
this.x = x;
this.y = y;
this.height = height;
this.width = width;
}
return Box;
}());
||
(or) operatorConsider the danger of ||
/or operators when setting default fallback values as shown in some other answers. This code below illustrates the wrong way to set defaults. You can get unexpected results when evaluating against falsey values like 0, '', null, undefined, false, NaN:
var myDesiredValue = 0;
var result = myDesiredValue || 2;
// This test will correctly report a problem with this setup.
console.assert(myDesiredValue === result && result === 0, 'Result should equal myDesiredValue. ' + myDesiredValue + ' does not equal ' + result);
In my tests, using es6/typescript destructured object can be 15-90% faster than Object.assign. Using a destructured parameter only allows methods and properties you've assigned to the object. For example, consider this method:
class BoxTest {
public x?: number = 1;
constructor(params: BoxTest = {} as BoxTest) {
Object.assign(this, params);
}
}
If another user wasn't using TypeScript and attempted to place a parameter that didn't belong, say, they might try putting a z
property
var box = new BoxTest({x: 0, y: 87, width: 4, height: 0, z: 7});
// This test will correctly report an error with this setup. `z` was defined even though `z` is not an allowed property of params.
console.assert(typeof box.z === 'undefined')
I think what you may be thinking of is expressions
or "dynamic properties", which are only supported by IE and let you set a property to the result of a javascript expression. Example:
width:expression(document.body.clientWidth > 800? "800px": "auto" );
This code makes IE emulate the max-width
property it doesn't support.
All things considered, however, avoid using these. They are a bad, bad thing.
Use CDATA
tags:
<![CDATA[
This is some text with ampersands & other funny characters. >>
]]>
Another way (although it is a longer code) but it is faster than the above codes. Check it using %timeit function:
df[df.index.isin([1,3])]
PS: You figure out the reason
This works with Browser and Hash history.
this.props.history.goBack();
The attribute align=middle
sets vertical alignment. To set horizontal alignment using HTML, you can wrap the element inside a center
element and remove all the CSS you have now.
<center><img src=_x000D_
"http://icons.iconarchive.com/icons/rokey/popo-emotions/128/big-smile-icon.png"_x000D_
width="42" height="42"></center>
_x000D_
If you would rather do it in CSS, there are several ways. A simple one is to set text-align
on a container:
<div style="text-align: center"><img src=_x000D_
"http://icons.iconarchive.com/icons/rokey/popo-emotions/128/big-smile-icon.png"_x000D_
width="42" height="42"></div>
_x000D_
Starting with .Net 4.5 you can use Task.Run to simply start an action:
void Foo(string args){}
...
Task.Run(() => Foo("bar"));
Illegal offset type errors occur when you attempt to access an array index using an object or an array as the index key.
Example:
$x = new stdClass();
$arr = array();
echo $arr[$x];
//illegal offset type
Your $xml
array contains an object or array at $xml->entry[$i]->source
for some value of $i
, and when you try to use that as an index key for $s
, you get that warning. You'll have to make sure $xml
contains what you want it to and that you're accessing it correctly.
The function 'numerically' below serves the purpose of sorting array of numbers numerically in many cases when provided as a callback function:
function numerically(a, b){
return a-b;
}
array.sort(numerically);
But in some rare instances, where array contains very large and negative numbers, an overflow error can occur as the result of a-b gets smaller than the smallest number that JavaScript can cope with.
So a better way of writing numerically function is as follows:
function numerically(a, b){
if(a < b){
return -1;
} else if(a > b){
return 1;
} else {
return 0;
}
}
You can now use Modern ECMAScript syntax thanks to V8 Runtime.
You can use includes():
var grade = itemResponse.getResponse();
if(grade.includes("9th")){do something}
You should also try -ggdb instead of -g if you're compiling for Android!
for i in range(1,len(na_rm.columns)):
print ("column name:", na_rm.columns[i])
Output :
column name: seretide_price
column name: symbicort_mkt_shr
column name: symbicort_price
Gender :<br>
<input type="radio" name="g" value="male" <?php echo ($g=='Male')?'checked':'' ?>>male <br>
<input type="radio" name="g" value="female"<?php echo ($g=='female')?'checked':'' ?>>female
<?php echo $errors['g'];?>
Another simple way:
ActiveSheet.Rows(ActiveSheet.UsedRange.Rows.Count+1).Select
Selection.EntireRow.Delete
or simpler:
ActiveSheet.Rows(ActiveSheet.UsedRange.Rows.Count+1).EntireRow.Delete
I generally use the typeof
operator:
if (typeof obj.foo !== 'undefined') {
// your code here
}
It will return "undefined"
either if the property doesn't exist or its value is undefined
.
(See also: Difference between undefined
and not being defined.)
There are other ways to figure out if a property exists on an object, like the hasOwnProperty
method:
if (obj.hasOwnProperty('foo')) {
// your code here
}
And the in
operator:
if ('foo' in obj) {
// your code here
}
The difference between the last two is that the hasOwnProperty
method will check if the property exist physically on the object (the property is not inherited).
The in
operator will check on all the properties reachable up in the prototype chain, e.g.:
var obj = { foo: 'bar'};
obj.hasOwnProperty('foo'); // true
obj.hasOwnProperty('toString'); // false
'toString' in obj; // true
As you can see, hasOwnProperty
returns false
and the in
operator returns true
when checking the toString
method, this method is defined up in the prototype chain, because obj
inherits form Object.prototype
.
A missing intermediate certificate might be the problem.
You may want to check your https://hostname with curl, openssl or a website like https://www.digicert.com/help/.
No idea why Chrome (possibly) sometimes has problems validating these certs.