Using generic std::function objects with member functions in one class
Either you need
std::function<void(Foo*)> f = &Foo::doSomething;
so that you can call it on any instance, or you need to bind a specific instance, for example this
std::function<void(void)> f = std::bind(&Foo::doSomething, this);
Limit text length to n lines using CSS
What you can do is the following:
.max-lines {_x000D_
display: block;/* or inline-block */_x000D_
text-overflow: ellipsis;_x000D_
word-wrap: break-word;_x000D_
overflow: hidden;_x000D_
max-height: 3.6em;_x000D_
line-height: 1.8em;_x000D_
}<p class="max-lines">Lorem ipsum dolor sit amet, consectetur adipiscing elit. Nunc vitae leo dapibus, accumsan lorem eleifend, pharetra quam. Quisque vestibulum commodo justo, eleifend mollis enim blandit eu. Aenean hendrerit nisl et elit maximus finibus. Suspendisse scelerisque consectetur nisl mollis scelerisque.</p>where max-height: = line-height: × <number-of-lines> in em.
iOS 8 removed "minimal-ui" viewport property, are there other "soft fullscreen" solutions?
Since there is no programmatic way to mimic minimal-ui, we have come up with a different workaround, using calc() and known iOS address bar height to our advantage:
The following demo page (also available on gist, more technical details there) will prompt user to scroll, which then triggers a soft-fullscreen (hide address bar/menu), where header and content fills the new viewport.
<!doctype html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Scroll Test</title>
<style>
html, body {
height: 100%;
}
html {
background-color: red;
}
body {
background-color: blue;
margin: 0;
}
div.header {
width: 100%;
height: 40px;
background-color: green;
overflow: hidden;
}
div.content {
height: 100%;
height: calc(100% - 40px);
width: 100%;
background-color: purple;
overflow: hidden;
}
div.cover {
position: absolute;
top: 0;
left: 0;
z-index: 100;
width: 100%;
height: 100%;
overflow: hidden;
background-color: rgba(0, 0, 0, 0.5);
color: #fff;
display: none;
}
@media screen and (width: 320px) {
html {
height: calc(100% + 72px);
}
div.cover {
display: block;
}
}
</style>
<script>
var timeout;
window.addEventListener('scroll', function(ev) {
if (timeout) {
clearTimeout(timeout);
}
timeout = setTimeout(function() {
if (window.scrollY > 0) {
var cover = document.querySelector('div.cover');
cover.style.display = 'none';
}
}, 200);
});
</script>
</head>
<body>
<div class="header">
<p>header</p>
</div>
<div class="content">
<p>content</p>
</div>
<div class="cover">
<p>scroll to soft fullscreen</p>
</div>
</body>
</html>
Could not load file or assembly Microsoft.SqlServer.management.sdk.sfc version 11.0.0.0
Just want to share my experience on this.
I, too, encountered this error. I'm using MS Visual Studio 2013 and I have an MS SQL Server 2008, though I have had MS SQL Server 2012 Installed before.
I was banging my head on this error for a day. I tried installing SharedManagementObject, SQLSysClrTypes and Native Client, but it didn't work. Why? Well I finally figured that I was installing 2008 or 2012 version of the said files, while I'm using Visual Studio 2013!! My idea is since it is a database issue, the version of the files should be the same with the MS SQL Server installed on the laptop, but apparently, I should have installed the 2013 version because the error is from the Visual Studio and not from the SQL Server.
Can you have a <span> within a <span>?
HTML4 specification states that:
Inline elements may contain only data and other inline elements
Span is an inline element, therefore having span inside span is valid. There's a related question: Can <span> tags have any type of tags inside them? which makes it completely clear.
HTML5 specification (including the most current draft of HTML 5.3 dated November 16, 2017) changes terminology, but it's still perfectly valid to place span inside another span.
How to pass argument to Makefile from command line?
You probably shouldn't do this; you're breaking the basic pattern of how Make works. But here it is:
action:
@echo action $(filter-out $@,$(MAKECMDGOALS))
%: # thanks to chakrit
@: # thanks to William Pursell
EDIT:
To explain the first command,
$(MAKECMDGOALS) is the list of "targets" spelled out on the command line, e.g. "action value1 value2".
$@ is an automatic variable for the name of the target of the rule, in this case "action".
filter-out is a function that removes some elements from a list. So $(filter-out bar, foo bar baz) returns foo baz (it can be more subtle, but we don't need subtlety here).
Put these together and $(filter-out $@,$(MAKECMDGOALS)) returns the list of targets specified on the command line other than "action", which might be "value1 value2".
SQL Query to fetch data from the last 30 days?
The easiest way would be to specify
SELECT productid FROM product where purchase_date > sysdate-30;
Remember this sysdate above has the time component, so it will be purchase orders newer than 03-06-2011 8:54 AM based on the time now.
If you want to remove the time conponent when comparing..
SELECT productid FROM product where purchase_date > trunc(sysdate-30);
And (based on your comments), if you want to specify a particular date, make sure you use to_date and not rely on the default session parameters.
SELECT productid FROM product where purchase_date > to_date('03/06/2011','mm/dd/yyyy')
And regardng the between (sysdate-30) - (sysdate) comment, for orders you should be ok with usin just the sysdate condition unless you can have orders with order_dates in the future.
LINQ where clause with lambda expression having OR clauses and null values returning incomplete results
You are checking Parent properties for null in your delegate. The same should work with lambda expressions too.
List<AnalysisObject> analysisObjects = analysisObjectRepository
.FindAll()
.Where(x =>
(x.ID == packageId) ||
(x.Parent != null &&
(x.Parent.ID == packageId ||
(x.Parent.Parent != null && x.Parent.Parent.ID == packageId)))
.ToList();
mongodb how to get max value from collections
You can also achieve this through aggregate pipeline.
db.collection.aggregate([{$sort:{age:-1}}, {$limit:1}])
Java 8 forEach with index
There are workarounds but no clean/short/sweet way to do it with streams and to be honest, you would probably be better off with:
int idx = 0;
for (Param p : params) query.bind(idx++, p);
Or the older style:
for (int idx = 0; idx < params.size(); idx++) query.bind(idx, params.get(idx));
How to change sender name (not email address) when using the linux mail command for autosending mail?
You just need to add a From: header. By default there is none.
echo "Test" | mail -a "From: Someone <[email protected]>" [email protected]
You can add any custom headers using -a:
echo "Test" | mail -a "From: Someone <[email protected]>" \
-a "Subject: This is a test" \
-a "X-Custom-Header: yes" [email protected]
deny directory listing with htaccess
Try adding this to the .htaccess file in that directory.
Options -Indexes
This has more information.
How to initialize private static members in C++?
I follow the idea from Karl. I like it and now I use it as well. I've changed a little bit the notation and add some functionality
#include <stdio.h>
class Foo
{
public:
int GetMyStaticValue () const { return MyStatic(); }
int & GetMyStaticVar () { return MyStatic(); }
static bool isMyStatic (int & num) { return & num == & MyStatic(); }
private:
static int & MyStatic ()
{
static int mStatic = 7;
return mStatic;
}
};
int main (int, char **)
{
Foo obj;
printf ("mystatic value %d\n", obj.GetMyStaticValue());
obj.GetMyStaticVar () = 3;
printf ("mystatic value %d\n", obj.GetMyStaticValue());
int valMyS = obj.GetMyStaticVar ();
int & iPtr1 = obj.GetMyStaticVar ();
int & iPtr2 = valMyS;
printf ("is my static %d %d\n", Foo::isMyStatic(iPtr1), Foo::isMyStatic(iPtr2));
}
this outputs
mystatic value 7
mystatic value 3
is my static 1 0
Adding local .aar files to Gradle build using "flatDirs" is not working
For anyone who has this problem as of Android Studio 1.4, I got it to work by creating a module within the project that contains 2 things.
build.gradle with the following contents:
configurations.create("default")artifacts.add("default", file('facebook-android-sdk-4.7.0.aar'))the aar file (in this example 'facebook-android-sdk-4.7.0.aar')
Then include the new library as a module dependency. Now you can use a built aar without including the sources within the project.
Credit to Facebook for this hack. I found the solution while integrating the Android SDK into a project.
How to set data attributes in HTML elements
Vanilla Javascript solution
HTML
<div id="mydiv" data-myval="10"></div>
JavaScript:
Using DOM's
getAttribute()propertyvar brand = mydiv.getAttribute("data-myval")//returns "10" mydiv.setAttribute("data-myval", "20") //changes "data-myval" to "20" mydiv.removeAttribute("data-myval") //removes "data-myval" attribute entirelyUsing JavaScript's
datasetpropertyvar myval = mydiv.dataset.myval //returns "10" mydiv.dataset.myval = '20' //changes "data-myval" to "20" mydiv.dataset.myval = null //removes "data-myval" attribute
How to fluently build JSON in Java?
You can use one of Java template engines. I love this method because you are separating your logic from the view.
Java 8+:
<dependency>
<groupId>com.github.spullara.mustache.java</groupId>
<artifactId>compiler</artifactId>
<version>0.9.6</version>
</dependency>
Java 6/7:
<dependency>
<groupId>com.github.spullara.mustache.java</groupId>
<artifactId>compiler</artifactId>
<version>0.8.18</version>
</dependency>
Example template file:
{{#items}}
Name: {{name}}
Price: {{price}}
{{#features}}
Feature: {{description}}
{{/features}}
{{/items}}
Might be powered by some backing code:
public class Context {
List<Item> items() {
return Arrays.asList(
new Item("Item 1", "$19.99", Arrays.asList(new Feature("New!"), new Feature("Awesome!"))),
new Item("Item 2", "$29.99", Arrays.asList(new Feature("Old."), new Feature("Ugly.")))
);
}
static class Item {
Item(String name, String price, List<Feature> features) {
this.name = name;
this.price = price;
this.features = features;
}
String name, price;
List<Feature> features;
}
static class Feature {
Feature(String description) {
this.description = description;
}
String description;
}
}
And would result in:
Name: Item 1
Price: $19.99
Feature: New!
Feature: Awesome!
Name: Item 2
Price: $29.99
Feature: Old.
Feature: Ugly.
- mustache: https://github.com/spullara/mustache.java
- But there is also Jinja: https://github.com/HubSpot/jinjava
- And carrot: https://github.com/codeka/carrot
Creating a segue programmatically
I thought I would add another possibility. One of the things you can do is you can connect two scenes in a storyboard using a segue that is not attached to an action, and then programmatically trigger the segue inside your view controller. The way you do this, is that you have to drag from the file's owner icon at the bottom of the storyboard scene that is the segueing scene, and right drag to the destination scene. I'll throw in an image to help explain.
A popup will show for "Manual Segue". I picked Push as the type. Tap on the little square and make sure you're in the attributes inspector. Give it an identifier which you will use to refer to it in code.
Ok, next I'm going to segue using a programmatic bar button item. In viewDidLoad or somewhere else I'll create a button item on the navigation bar with this code:
UIBarButtonItem *buttonizeButton = [[UIBarButtonItem alloc] initWithTitle:@"Buttonize"
style:UIBarButtonItemStyleDone
target:self
action:@selector(buttonizeButtonTap:)];
self.navigationItem.rightBarButtonItems = @[buttonizeButton];
Ok, notice that the selector is buttonizeButtonTap:. So write a void method for that button and within that method you will call the segue like this:
-(void)buttonizeButtonTap:(id)sender{
[self performSegueWithIdentifier:@"Associate" sender:sender];
}
The sender parameter is required to identify the button when prepareForSegue is called. prepareForSegue is the framework method where you will instantiate your scene and pass it whatever values it will need to do its work. Here's what my method looks like:
- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{
if ([[segue identifier] isEqualToString:@"Associate"])
{
TranslationQuizAssociateVC *translationQuizAssociateVC = [segue destinationViewController];
translationQuizAssociateVC.nodeID = self.nodeID; //--pass nodeID from ViewNodeViewController
translationQuizAssociateVC.contentID = self.contentID;
translationQuizAssociateVC.index = self.index;
translationQuizAssociateVC.content = self.content;
}
}
Ok, just tested it and it works. Hope it helps you.
Style the first <td> column of a table differently
The :nth-child() and :nth-of-type() pseudo-classes allows you to select elements with a formula.
The syntax is :nth-child(an+b), where you replace a and b by numbers of your choice.
For instance, :nth-child(3n+1) selects the 1st, 4th, 7th etc. child.
td:nth-child(3n+1) {
/* your stuff here */
}
:nth-of-type() works the same, except that it only considers element of the given type ( in the example).
pandas read_csv and filter columns with usecols
import csv first and use csv.DictReader its easy to process...
Understanding the order() function
(I thought it might be helpful to lay out the ideas very simply here to summarize the good material posted by @doug, & linked by @duffymo; +1 to each,btw.)
?order tells you which element of the original vector needs to be put first, second, etc., so as to sort the original vector, whereas ?rank tell you which element has the lowest, second lowest, etc., value. For example:
> a <- c(45, 50, 10, 96)
> order(a)
[1] 3 1 2 4
> rank(a)
[1] 2 3 1 4
So order(a) is saying, 'put the third element first when you sort... ', whereas rank(a) is saying, 'the first element is the second lowest... '. (Note that they both agree on which element is lowest, etc.; they just present the information differently.) Thus we see that we can use order() to sort, but we can't use rank() that way:
> a[order(a)]
[1] 10 45 50 96
> sort(a)
[1] 10 45 50 96
> a[rank(a)]
[1] 50 10 45 96
In general, order() will not equal rank() unless the vector has been sorted already:
> b <- sort(a)
> order(b)==rank(b)
[1] TRUE TRUE TRUE TRUE
Also, since order() is (essentially) operating over ranks of the data, you could compose them without affecting the information, but the other way around produces gibberish:
> order(rank(a))==order(a)
[1] TRUE TRUE TRUE TRUE
> rank(order(a))==rank(a)
[1] FALSE FALSE FALSE TRUE
SyntaxError of Non-ASCII character
You should define source code encoding, add this to the top of your script:
# -*- coding: utf-8 -*-
The reason why it works differently in console and in the IDE is, likely, because of different default encodings set. You can check it by running:
import sys
print sys.getdefaultencoding()
Also see:
ActiveModel::ForbiddenAttributesError when creating new user
Alternatively you can use the Protected Attributes gem, however this defeats the purpose of requiring strong params. However if you're upgrading an older app, Protected Attributes does provide an easy pathway to upgrade until such time that you can refactor the attr_accessible to strong params.
bootstrap multiselect get selected values
$('#multiselect1').on('change', function(){
var selected = $(this).find("option:selected");
var arrSelected = [];
// selected.each(function(){
// arrSelected.push($(this).val());
// });
// The problem with the above selected.each statement is that
// there is no iteration value.
// $(this).val() is all selected items, not an iterative item value.
// With each iteration the selected items will be appended to
// arrSelected like so
//
// arrSelected [0]['item0','item1','item2']
// arrSelected [1]['item0','item1','item2']
// You need to get the iteration value.
//
selected.each((idx, val) => {
arrSelected.push(val.value);
});
// arrSelected [0]['item0']
// arrSelected [1]['item1']
// arrSelected [2]['item2']
});
How to revert uncommitted changes including files and folders?
I think you can use the following command: git reset --hard
How can I create a UIColor from a hex string?
Swift 2.0 - Xcode 7.2
Adding an extension to UIColor.
File -New - Swift File - Name it . Add the following.
extension UIColor {
convenience init(hexString:String) {
let hexString:NSString = hexString.stringByTrimmingCharactersInSet(NSCharacterSet.whitespaceAndNewlineCharacterSet())
let scanner = NSScanner(string: hexString as String)
if (hexString.hasPrefix("#")) {
scanner.scanLocation = 1
}
var color:UInt32 = 0
scanner.scanHexInt(&color)
let mask = 0x000000FF
let r = Int(color >> 16) & mask
let g = Int(color >> 8) & mask
let b = Int(color) & mask
let red = CGFloat(r) / 255.0
let green = CGFloat(g) / 255.0
let blue = CGFloat(b) / 255.0
self.init(red:red, green:green, blue:blue, alpha:1)
}
func toHexString() -> String {
var r:CGFloat = 0
var g:CGFloat = 0
var b:CGFloat = 0
var a:CGFloat = 0
getRed(&r, green: &g, blue: &b, alpha: &a)
let rgb:Int = (Int)(r*255)<<16 | (Int)(g*255)<<8 | (Int)(b*255)<<0
return NSString(format:"#%06x", rgb) as String
}
}
Usage:
Ex. Setting Button's color from hexCode.
override func viewWillAppear(animated: Bool) {
loginButton.tintColor = UIColor(hexString: " hex code here ")
}
Ex. Converting Button's current color to hex Code.
override func viewWillAppear(animated: Bool) {
let hexString = loginButton.tintColor.toHexString()
print("HEX STRING: \(hexString)")
}
Auto logout with Angularjs based on idle user
ng-Idle looks like the way to go, but I could not figure out Brian F's modifications and wanted to timeout for a sleeping session too, also I had a pretty simple use case in mind. I pared it down to the code below. It hooks events to reset a timeout flag (lazily placed in $rootScope). It only detects the timeout has happened when the user returns (and triggers an event) but that's good enough for me. I could not get angular's $location to work here but again, using document.location.href gets the job done.
I stuck this in my app.js after the .config has run.
app.run(function($rootScope,$document)
{
var d = new Date();
var n = d.getTime(); //n in ms
$rootScope.idleEndTime = n+(20*60*1000); //set end time to 20 min from now
$document.find('body').on('mousemove keydown DOMMouseScroll mousewheel mousedown touchstart', checkAndResetIdle); //monitor events
function checkAndResetIdle() //user did something
{
var d = new Date();
var n = d.getTime(); //n in ms
if (n>$rootScope.idleEndTime)
{
$document.find('body').off('mousemove keydown DOMMouseScroll mousewheel mousedown touchstart'); //un-monitor events
//$location.search('IntendedURL',$location.absUrl()).path('/login'); //terminate by sending to login page
document.location.href = 'https://whatever.com/myapp/#/login';
alert('Session ended due to inactivity');
}
else
{
$rootScope.idleEndTime = n+(20*60*1000); //reset end time
}
}
});
How to get an input text value in JavaScript
How to get an input text value in JavaScript
var textbox;_x000D_
function onload() { _x000D_
//Get value._x000D_
textbox = document.getElementById('textbox');_x000D_
}_x000D_
_x000D_
function showMessage() { _x000D_
//Show message in alert()_x000D_
alert("The message is: " + textbox.value);_x000D_
}<body onload="onload();">_x000D_
<div>_x000D_
<input type="text" name="enter" class="enter" placeholder="Write something here!" value="It´s a wonderful day!" id="textbox"/>_x000D_
<input type="button" value="Show this message!" onClick="showMessage()" />_x000D_
</div>Missing artifact com.sun:tools:jar
I had the same problem on a Windows 7 and Eclipse 3.7 I managed to fix it by starting
eclipse.exe -vm "D:\JDK6\bin"
You can start a cmd and launch eclipse like that, or you can edit your shortcut and add -vm "D:\JDK6\bin" as an argument in the "target section".
As a sidenote, I also tried to add -vm "D:\JDK6\bin" to eclipse.ini but did not work. And adding JRE6 will not work since it does NOT contain tools.jar in it's "lib" directory. Only JDK does.
how to find 2d array size in c++
The other answers above have answered your first question. As for your second question, how to detect an error of getting a value that is not set, I am not sure which of the following situation you mean:
Accessing an array element using an invalid index:
If you use std::vector, you can use vector::at function instead of [] operator to get the value, if the index is invalid, an out_of_range exception will be thrown.Accessing a valid index, but the element has not been set yet: As far as I know, there is no direct way of it. However, the following common practices can probably solve you problem: (1) Initializes all elements to a value that you are certain that is impossible to have. For example, if you are dealing with positive integers, set all elements to -1, so you know the value is not set yet when you find it being -1. (2). Simply use a bool array of the same size to indicate whether the element of the same index is set or not, this applies when all values are "possible".
Matplotlib scatter plot with different text at each data point
As a one liner using list comprehension and numpy:
[ax.annotate(x[0], (x[1], x[2])) for x in np.array([n,z,y]).T]
setup is ditto to Rutger's answer.
scrollTop animation without jquery
HTML:
<button onclick="scrollToTop(1000);"></button>
1# JavaScript (linear):
function scrollToTop (duration) {
// cancel if already on top
if (document.scrollingElement.scrollTop === 0) return;
const totalScrollDistance = document.scrollingElement.scrollTop;
let scrollY = totalScrollDistance, oldTimestamp = null;
function step (newTimestamp) {
if (oldTimestamp !== null) {
// if duration is 0 scrollY will be -Infinity
scrollY -= totalScrollDistance * (newTimestamp - oldTimestamp) / duration;
if (scrollY <= 0) return document.scrollingElement.scrollTop = 0;
document.scrollingElement.scrollTop = scrollY;
}
oldTimestamp = newTimestamp;
window.requestAnimationFrame(step);
}
window.requestAnimationFrame(step);
}
2# JavaScript (ease in and out):
function scrollToTop (duration) {
// cancel if already on top
if (document.scrollingElement.scrollTop === 0) return;
const cosParameter = document.scrollingElement.scrollTop / 2;
let scrollCount = 0, oldTimestamp = null;
function step (newTimestamp) {
if (oldTimestamp !== null) {
// if duration is 0 scrollCount will be Infinity
scrollCount += Math.PI * (newTimestamp - oldTimestamp) / duration;
if (scrollCount >= Math.PI) return document.scrollingElement.scrollTop = 0;
document.scrollingElement.scrollTop = cosParameter + cosParameter * Math.cos(scrollCount);
}
oldTimestamp = newTimestamp;
window.requestAnimationFrame(step);
}
window.requestAnimationFrame(step);
}
/*
Explanation:
- pi is the length/end point of the cosinus intervall (see below)
- newTimestamp indicates the current time when callbacks queued by requestAnimationFrame begin to fire.
(for more information see https://developer.mozilla.org/en-US/docs/Web/API/window/requestAnimationFrame)
- newTimestamp - oldTimestamp equals the delta time
a * cos (bx + c) + d | c translates along the x axis = 0
= a * cos (bx) + d | d translates along the y axis = 1 -> only positive y values
= a * cos (bx) + 1 | a stretches along the y axis = cosParameter = window.scrollY / 2
= cosParameter + cosParameter * (cos bx) | b stretches along the x axis = scrollCount = Math.PI / (scrollDuration / (newTimestamp - oldTimestamp))
= cosParameter + cosParameter * (cos scrollCount * x)
*/
Note:
- Duration in milliseconds (1000ms = 1s)
- Second script uses the cos function. Example curve:
3# Simple scrolling library on Github
Can we update primary key values of a table?
Short answer: yes you can. Of course you'll have to make sure that the new value doesn't match any existing value and other constraints are satisfied (duh).
What exactly are you trying to do?
How to listen for a WebView finishing loading a URL?
Just to show progress bar, "onPageStarted" and "onPageFinished" methods are enough; but if you want to have an "is_loading" flag (along with page redirects, ...), this methods may executed with non-sequencing, like "onPageStarted > onPageStarted > onPageFinished > onPageFinished" queue.
But with my short test (test it yourself.), "onProgressChanged" method values queue is "0-100 > 0-100 > 0-100 > ..."
private boolean is_loading = false;
webView.setWebChromeClient(new MyWebChromeClient(context));
private final class MyWebChromeClient extends WebChromeClient{
@Override
public void onProgressChanged(WebView view, int newProgress) {
if (newProgress == 0){
is_loading = true;
} else if (newProgress == 100){
is_loading = false;
}
super.onProgressChanged(view, newProgress);
}
}
Also set "is_loading = false" on activity close, if it is a static variable because activity can be finished before page finish.
How can I escape white space in a bash loop list?
To add to what Jonathan said: use the -print0 option for find in conjunction with xargs as follows:
find test/* -type d -print0 | xargs -0 command
That will execute the command command with the proper arguments; directories with spaces in them will be properly quoted (i.e. they'll be passed in as one argument).
C# binary literals
C# 7.0 supports binary literals (and optional digit separators via underscore characters).
An example:
int myValue = 0b0010_0110_0000_0011;
You can also find more information on the Roslyn GitHub page.
Exposing a port on a live Docker container
I wrote a blog post that explains how to access an unpublished port of a container In different ways depending on the needs:
- by committing a new image and running a new container,
- by using socat to avoid restarting the container.
The post also goes through a brief introduction of both how port mapping works, the difference between exposing and publishing a port, and what is socat.
Here’s the link: https://lmcaraig.com/accessing-an-unpublished-port-of-a-running-docker-container
Android Studio Error: Error:CreateProcess error=216, This version of %1 is not compatible with the version of Windows you're running
Don't worry... Its much easy to solve your problem. Just SET you SDK-LOCATION and JDK-LOCATION.
- Click on Configure ( As Soon Android studio open )
- Click Project Default
- Click Project Structure
Clik Android Sdk Location
Select & Browse your Android SDK Location (Like: C:\Android\sdk)
Uncheck USE EMBEDDED JDK LOCATION
- Set & Browse JDK Location, Like C:\Program Files\Java\jdk1.8.0_121
Correct way to initialize empty slice
The two alternative you gave are semantically identical, but using make([]int, 0) will result in an internal call to runtime.makeslice (Go 1.14).
You also have the option to leave it with a nil value:
var myslice []int
As written in the Golang.org blog:
a nil slice is functionally equivalent to a zero-length slice, even though it points to nothing. It has length zero and can be appended to, with allocation.
A nil slice will however json.Marshal() into "null" whereas an empty slice will marshal into "[]", as pointed out by @farwayer.
None of the above options will cause any allocation, as pointed out by @ArmanOrdookhani.
using c# .net libraries to check for IMAP messages from gmail servers
The URL listed here might be of interest to you
http://www.codeplex.com/InterIMAP
which was extension to
Jdbctemplate query for string: EmptyResultDataAccessException: Incorrect result size: expected 1, actual 0
In Postgres, you can make almost any single value query return a value or null by wrapping it:
SELECT (SELECT <query>) AS value
and hence avoid complexity in the caller.
Correct way of getting Client's IP Addresses from http.Request
Looking at http.Request you can find the following member variables:
// HTTP defines that header names are case-insensitive.
// The request parser implements this by canonicalizing the
// name, making the first character and any characters
// following a hyphen uppercase and the rest lowercase.
//
// For client requests certain headers are automatically
// added and may override values in Header.
//
// See the documentation for the Request.Write method.
Header Header
// RemoteAddr allows HTTP servers and other software to record
// the network address that sent the request, usually for
// logging. This field is not filled in by ReadRequest and
// has no defined format. The HTTP server in this package
// sets RemoteAddr to an "IP:port" address before invoking a
// handler.
// This field is ignored by the HTTP client.
RemoteAddr string
You can use RemoteAddr to get the remote client's IP address and port (the format is "IP:port"), which is the address of the original requestor or the last proxy (for example a load balancer which lives in front of your server).
This is all you have for sure.
Then you can investigate the headers, which are case-insensitive (per documentation above), meaning all of your examples will work and yield the same result:
req.Header.Get("X-Forwarded-For") // capitalisation
req.Header.Get("x-forwarded-for") // doesn't
req.Header.Get("X-FORWARDED-FOR") // matter
This is because internally http.Header.Get will normalise the key for you. (If you want to access header map directly, and not through Get, you would need to use http.CanonicalHeaderKey first.)
Finally, "X-Forwarded-For" is probably the field you want to take a look at in order to grab more information about client's IP. This greatly depends on the HTTP software used on the remote side though, as client can put anything in there if it wishes to. Also, note the expected format of this field is the comma+space separated list of IP addresses. You will need to parse it a little bit to get a single IP of your choice (probably the first one in the list), for example:
// Assuming format is as expected
ips := strings.Split("10.0.0.1, 10.0.0.2, 10.0.0.3", ", ")
for _, ip := range ips {
fmt.Println(ip)
}
will produce:
10.0.0.1
10.0.0.2
10.0.0.3
Using Get-childitem to get a list of files modified in the last 3 days
I wanted to just add this as a comment to the previous answer, but I can't. I tried Dave Sexton's answer but had problems if the count was 1. This forces an array even if one object is returned.
([System.Object[]](gci c:\pstback\ -Filter *.pst |
? { $_.LastWriteTime -gt (Get-Date).AddDays(-3)})).Count
It still doesn't return zero if empty, but testing '-lt 1' works.
How to ignore certain files in Git
If you have already committed the file and you are trying to ignore it by adding to the .gitignore file, Git will not ignore it. For that, you first have to do the below things:
git rm --cached FILENAME
If you are starting the project freshly and you want to add some files to Git ignore, follow the below steps to create a Git ignore file:
- Navigate to your Git repository.
- Enter "touch .gitignore" which will create a
.gitignorefile.
When is JavaScript synchronous?
JavaScript is single-threaded, and all the time you work on a normal synchronous code-flow execution.
Good examples of the asynchronous behavior that JavaScript can have are events (user interaction, Ajax request results, etc) and timers, basically actions that might happen at any time.
I would recommend you to give a look to the following article:
That article will help you to understand the single-threaded nature of JavaScript and how timers work internally and how asynchronous JavaScript execution works.
File path to resource in our war/WEB-INF folder?
There's a couple ways of doing this. As long as the WAR file is expanded (a set of files instead of one .war file), you can use this API:
ServletContext context = getContext();
String fullPath = context.getRealPath("/WEB-INF/test/foo.txt");
That will get you the full system path to the resource you are looking for. However, that won't work if the Servlet Container never expands the WAR file (like Tomcat). What will work is using the ServletContext's getResource methods.
ServletContext context = getContext();
URL resourceUrl = context.getResource("/WEB-INF/test/foo.txt");
or alternatively if you just want the input stream:
InputStream resourceContent = context.getResourceAsStream("/WEB-INF/test/foo.txt");
The latter approach will work no matter what Servlet Container you use and where the application is installed. The former approach will only work if the WAR file is unzipped before deployment.
EDIT:
The getContext() method is obviously something you would have to implement. JSP pages make it available as the context field. In a servlet you get it from your ServletConfig which is passed into the servlet's init() method. If you store it at that time, you can get your ServletContext any time you want after that.
How can I create a blank/hardcoded column in a sql query?
The answers above are correct, and what I'd consider the "best" answers. But just to be as complete as possible, you can also do this directly in CF using queryAddColumn.
See http://www.cfquickdocs.com/cf9/#queryaddcolumn
Again, it's more efficient to do it at the database level... but it's good to be aware of as many alternatives as possible (IMO, of course) :)
Android - SPAN_EXCLUSIVE_EXCLUSIVE spans cannot have a zero length
To try to debug this error, first go to your android terminal / console and execute this command:
ps | grep THE_ERROR_PID_YOU_GET_(IT_IS_A_NUMBER)
then if the output comes out as your app... it is your app causing the error. Try to look for empty Strings that you pass into the layout.
I had this exact same problem and it was my fault as I was passing an empty String into my layout. After changing the "" to " " this error went away.
If you don't get your app from the console output, then it is something else causing it (probably, as others said, the android keyboard)
how to check if string contains '+' character
Why not just:
int plusIndex = s.indexOf("+");
if (plusIndex != -1) {
String before = s.substring(0, plusIndex);
// Use before
}
It's not really clear why your original version didn't work, but then you didn't say what actually happened. If you want to split not using regular expressions, I'd personally use Guava:
Iterable<String> bits = Splitter.on('+').split(s);
String firstPart = Iterables.getFirst(bits, "");
If you're going to use split (either the built-in version or Guava) you don't need to check whether it contains + first - if it doesn't there'll only be one result anyway. Obviously there's a question of efficiency, but it's simpler code:
// Calling split unconditionally
String[] parts = s.split("\\+");
s = parts[0];
Note that writing String[] parts is preferred over String parts[] - it's much more idiomatic Java code.
Is it possible to use the instanceof operator in a switch statement?
Just in case if someone will read it:
The BEST solution in java is :
public enum Action {
a{
void doAction(...){
// some code
}
},
b{
void doAction(...){
// some code
}
},
c{
void doAction(...){
// some code
}
};
abstract void doAction (...);
}
The GREAT benefits of such pattern are:
You just do it like (NO switches at all):
void someFunction ( Action action ) { action.doAction(...); }In case if you add new Action called "d" you MUST imlement doAction(...) method
NOTE: This pattern is described in Joshua's Bloch "Effective Java (2nd Edition)"
Dart/Flutter : Converting timestamp
If you are here to just convert Timestamp into DateTime,
Timestamp timestamp = widget.firebaseDocument[timeStampfield];
DateTime date = Timestamp.fromMillisecondsSinceEpoch(
timestamp.millisecondsSinceEpoch).toDate();
How to delete files/subfolders in a specific directory at the command prompt in Windows
This will remove the folders and files and leave the folder behind.
pushd "%pathtofolder%" && (rd /s /q "%pathtofolder%" 2>nul & popd)
Eclipse: Error ".. overlaps the location of another project.." when trying to create new project
simply "CUT" project folder and move it out of workspace directory and do the following
file=>import=>(select new directory)=> mark (copy to my workspace) checkbox
and you done !
Normalizing a list of numbers in Python
If working with data, many times pandas is the simple key
This particular code will put the raw into one column, then normalize by column per row. (But we can put it into a row and do it by row per column, too! Just have to change the axis values where 0 is for row and 1 is for column.)
import pandas as pd
raw = [0.07, 0.14, 0.07]
raw_df = pd.DataFrame(raw)
normed_df = raw_df.div(raw_df.sum(axis=0), axis=1)
normed_df
where normed_df will display like:
0
0 0.25
1 0.50
2 0.25
and then can keep playing with the data, too!
Turning error reporting off php
Read up on the configuration settings (e.g., display_errors, display_startup_errors, log_errors) and update your php.ini or .htaccess or .user.ini file, whichever is appropriate.
It works.
How to synchronize or lock upon variables in Java?
From Java 1.5 it's always a good Idea to consider java.util.concurrent package. They are the state of the art locking mechanism in java right now. The synchronize mechanism is more heavyweight that the java.util.concurrent classes.
The example would look something like this:
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReentrantLock;
public class Sample {
private final Lock lock = new ReentrantLock();
private String message = null;
public void newmsg(String msg) {
lock.lock();
try {
message = msg;
} finally {
lock.unlock();
}
}
public String getmsg() {
lock.lock();
try {
String temp = message;
message = null;
return temp;
} finally {
lock.unlock();
}
}
}
C# Validating input for textbox on winforms
Description
There are many ways to validate your TextBox. You can do this on every keystroke, at a later time, or on the Validating event.
The Validating event gets fired if your TextBox looses focus. When the user clicks on a other Control, for example. If your set e.Cancel = true the TextBox doesn't lose the focus.
MSDN - Control.Validating Event When you change the focus by using the keyboard (TAB, SHIFT+TAB, and so on), by calling the Select or SelectNextControl methods, or by setting the ContainerControl.ActiveControl property to the current form, focus events occur in the following order
Enter
GotFocus
Leave
Validating
Validated
LostFocus
When you change the focus by using the mouse or by calling the Focus method, focus events occur in the following order:
Enter
GotFocus
LostFocus
Leave
Validating
Validated
Sample Validating Event
private void textBox1_Validating(object sender, CancelEventArgs e)
{
if (textBox1.Text != "something")
e.Cancel = true;
}
Update
You can use the ErrorProvider to visualize that your TextBox is not valid.
Check out Using Error Provider Control in Windows Forms and C#
More Information
Is there an onSelect event or equivalent for HTML <select>?
Actually, the onclick events will NOT fire when the user uses the keyboard to change the selection in the select control. You might have to use a combination of onChange and onClick to get the behavior you're looking for.
href="file://" doesn't work
Share your folder for "everyone" or some specific group and try this:
<a href="file://YOURSERVERNAME/AmberCRO%20SOP/2011-07-05/SOP-SOP-3.0.pdf"> Download PDF </a> Difference between /res and /assets directories
Both are pretty similar. The real main difference between the two is that in the res directory each file is given a pre-compiled ID which can be accessed easily through R.id.[res id]. This is useful to quickly and easily access images, sounds, icons...
The assets directory is more like a filesystem and provides more freedom to put any file you would like in there. You then can access each of the files in that system as you would when accessing any file in any file system through Java. This directory is good for things such as game details, dictionaries,...etc. Hope that helps.
get index of DataTable column with name
You can use DataColumn.Ordinal to get the index of the column in the DataTable. So if you need the next column as mentioned use Column.Ordinal + 1:
row[row.Table.Columns["ColumnName"].Ordinal + 1] = someOtherValue;
J2ME/Android/BlackBerry - driving directions, route between two locations
J2ME Map Route Provider
maps.google.com has a navigation service which can provide you route information in KML format.
To get kml file we need to form url with start and destination locations:
public static String getUrl(double fromLat, double fromLon,
double toLat, double toLon) {// connect to map web service
StringBuffer urlString = new StringBuffer();
urlString.append("http://maps.google.com/maps?f=d&hl=en");
urlString.append("&saddr=");// from
urlString.append(Double.toString(fromLat));
urlString.append(",");
urlString.append(Double.toString(fromLon));
urlString.append("&daddr=");// to
urlString.append(Double.toString(toLat));
urlString.append(",");
urlString.append(Double.toString(toLon));
urlString.append("&ie=UTF8&0&om=0&output=kml");
return urlString.toString();
}
Next you will need to parse xml (implemented with SAXParser) and fill data structures:
public class Point {
String mName;
String mDescription;
String mIconUrl;
double mLatitude;
double mLongitude;
}
public class Road {
public String mName;
public String mDescription;
public int mColor;
public int mWidth;
public double[][] mRoute = new double[][] {};
public Point[] mPoints = new Point[] {};
}
Network connection is implemented in different ways on Android and Blackberry, so you will have to first form url:
public static String getUrl(double fromLat, double fromLon,
double toLat, double toLon)
then create connection with this url and get InputStream.
Then pass this InputStream and get parsed data structure:
public static Road getRoute(InputStream is)
Full source code RoadProvider.java
BlackBerry
class MapPathScreen extends MainScreen {
MapControl map;
Road mRoad = new Road();
public MapPathScreen() {
double fromLat = 49.85, fromLon = 24.016667;
double toLat = 50.45, toLon = 30.523333;
String url = RoadProvider.getUrl(fromLat, fromLon, toLat, toLon);
InputStream is = getConnection(url);
mRoad = RoadProvider.getRoute(is);
map = new MapControl();
add(new LabelField(mRoad.mName));
add(new LabelField(mRoad.mDescription));
add(map);
}
protected void onUiEngineAttached(boolean attached) {
super.onUiEngineAttached(attached);
if (attached) {
map.drawPath(mRoad);
}
}
private InputStream getConnection(String url) {
HttpConnection urlConnection = null;
InputStream is = null;
try {
urlConnection = (HttpConnection) Connector.open(url);
urlConnection.setRequestMethod("GET");
is = urlConnection.openInputStream();
} catch (IOException e) {
e.printStackTrace();
}
return is;
}
}
See full code on J2MEMapRouteBlackBerryEx on Google Code
Android
public class MapRouteActivity extends MapActivity {
LinearLayout linearLayout;
MapView mapView;
private Road mRoad;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
mapView = (MapView) findViewById(R.id.mapview);
mapView.setBuiltInZoomControls(true);
new Thread() {
@Override
public void run() {
double fromLat = 49.85, fromLon = 24.016667;
double toLat = 50.45, toLon = 30.523333;
String url = RoadProvider
.getUrl(fromLat, fromLon, toLat, toLon);
InputStream is = getConnection(url);
mRoad = RoadProvider.getRoute(is);
mHandler.sendEmptyMessage(0);
}
}.start();
}
Handler mHandler = new Handler() {
public void handleMessage(android.os.Message msg) {
TextView textView = (TextView) findViewById(R.id.description);
textView.setText(mRoad.mName + " " + mRoad.mDescription);
MapOverlay mapOverlay = new MapOverlay(mRoad, mapView);
List<Overlay> listOfOverlays = mapView.getOverlays();
listOfOverlays.clear();
listOfOverlays.add(mapOverlay);
mapView.invalidate();
};
};
private InputStream getConnection(String url) {
InputStream is = null;
try {
URLConnection conn = new URL(url).openConnection();
is = conn.getInputStream();
} catch (MalformedURLException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
return is;
}
@Override
protected boolean isRouteDisplayed() {
return false;
}
}
See full code on J2MEMapRouteAndroidEx on Google Code
How to pull remote branch from somebody else's repo
If the forked repo is protected so you can't push directly into it, and your goal is to make changes to their foo, then you need to get their branch foo into your repo like so:
git remote add protected_repo https://github.com/theirusername/their_repo.git
git fetch protected_repo
git checkout --no-track protected_repo/foo
Now you have a local copy of foo with no upstream associated to it. You can commit changes to it (or not) and then push your foo to your own remote repo.
git push --set-upstream origin foo
Now foo is in your repo on GitHub and your local foo is tracking it. If they continue to make changes to foo you can fetch theirs and merge into your foo.
git checkout foo
git fetch protected_repo
git merge protected_repo/foo
Web link to specific whatsapp contact
I tried all combination for swiss numbers on my webpage. Below my results:
Doesn't work for Android and iOS
https://wa.me/0790000000/?text=myText
Works for iOS but doesn't work for Android
https://wa.me/0041790000000/?text=myText
https://wa.me/+41790000000/?text=myText
Works for Android and iOS:
https://wa.me/41790000000/?text=myText
https://wa.me/041790000000/?text=myText
Hope this information helps somebody!
Better way to generate array of all letters in the alphabet
Check this once I'm sure you will get a to z alphabets:
for (char c = 'a'; c <= 'z'; c++) {
al.add(c);
}
System.out.println(al);'
How to get Current Directory?
I would recommend reading a book on C++ before you go any further, as it would be helpful to get a firmer footing. Accelerated C++ by Koenig and Moo is excellent.
To get the executable path use GetModuleFileName:
TCHAR buffer[MAX_PATH] = { 0 };
GetModuleFileName( NULL, buffer, MAX_PATH );
Here's a C++ function that gets the directory without the file name:
#include <windows.h>
#include <string>
#include <iostream>
wstring ExePath() {
TCHAR buffer[MAX_PATH] = { 0 };
GetModuleFileName( NULL, buffer, MAX_PATH );
std::wstring::size_type pos = std::wstring(buffer).find_last_of(L"\\/");
return std::wstring(buffer).substr(0, pos);
}
int main() {
std::cout << "my directory is " << ExePath() << "\n";
}
How to convert datatype:object to float64 in python?
You can convert most of the columns by just calling convert_objects:
In [36]:
df = df.convert_objects(convert_numeric=True)
df.dtypes
Out[36]:
Date object
WD int64
Manpower float64
2nd object
CTR object
2ndU float64
T1 int64
T2 int64
T3 int64
T4 float64
dtype: object
For column '2nd' and 'CTR' we can call the vectorised str methods to replace the thousands separator and remove the '%' sign and then astype to convert:
In [39]:
df['2nd'] = df['2nd'].str.replace(',','').astype(int)
df['CTR'] = df['CTR'].str.replace('%','').astype(np.float64)
df.dtypes
Out[39]:
Date object
WD int64
Manpower float64
2nd int32
CTR float64
2ndU float64
T1 int64
T2 int64
T3 int64
T4 object
dtype: object
In [40]:
df.head()
Out[40]:
Date WD Manpower 2nd CTR 2ndU T1 T2 T3 T4
0 2013/4/6 6 NaN 2645 5.27 0.29 407 533 454 368
1 2013/4/7 7 NaN 2118 5.89 0.31 257 659 583 369
2 2013/4/13 6 NaN 2470 5.38 0.29 354 531 473 383
3 2013/4/14 7 NaN 2033 6.77 0.37 396 748 681 458
4 2013/4/20 6 NaN 2690 5.38 0.29 361 528 541 381
Or you can do the string handling operations above without the call to astype and then call convert_objects to convert everything in one go.
UPDATE
Since version 0.17.0 convert_objects is deprecated and there isn't a top-level function to do this so you need to do:
df.apply(lambda col:pd.to_numeric(col, errors='coerce'))
See the docs and this related question: pandas: to_numeric for multiple columns
Open directory using C
Here is a simple way to implement ls command using c. To run use for example ./xls /tmp
#include<stdio.h>
#include <dirent.h>
void main(int argc,char *argv[])
{
DIR *dir;
struct dirent *dent;
dir = opendir(argv[1]);
if(dir!=NULL)
{
while((dent=readdir(dir))!=NULL)
{
if((strcmp(dent->d_name,".")==0 || strcmp(dent->d_name,"..")==0 || (*dent->d_name) == '.' ))
{
}
else
{
printf(dent->d_name);
printf("\n");
}
}
}
close(dir);
}
java.text.ParseException: Unparseable date
- Your formatting pattern fails to match the input string, as noted by other Answers.
- Your input format is terrible.
- You are using troublesome old date-time classes that were supplanted years ago by the java.time classes.
ISO 8601
Instead a format such as yours, use ISO 8601 standard formats for exchanging date-time values as text.
The java.time classes use the standard ISO 8601 formats by default when parsing/generating strings.
Proper time zone name
Specify a proper time zone name in the format of continent/region, such as America/Montreal, Africa/Casablanca, or Pacific/Auckland. Never use the 3-4 letter abbreviation such as EST or IST as they are not true time zones, not standardized, and not even unique(!).
Your IST could mean Iceland Standard Time, India Standard Time, Ireland Standard Time, or others. The java.time classes are left to merely guessing, as there is no logical solution to this ambiguity.
java.time
The modern approach uses the java.time classes.
Define a formatting pattern to match your input strings.
String input = "Sat Jun 01 12:53:10 IST 2013";
DateTimeFormatter f = DateTimeFormatter.ofPattern( "EEE MMM dd HH:mm:ss z uuuu" , Locale.US );
ZonedDateTime zdt = ZonedDateTime.parse( input , f );
zdt.toString(): 2013-06-01T12:53:10Z[Atlantic/Reykjavik]
If your input was not intended for Iceland, you should pre-parse the string to adjust to a proper time zone name. For example, if you are certain the input was intended for India, change IST to Asia/Kolkata.
String input = "Sat Jun 01 12:53:10 IST 2013".replace( "IST" , "Asia/Kolkata" );
DateTimeFormatter f = DateTimeFormatter.ofPattern( "EEE MMM dd HH:mm:ss z uuuu" , Locale.US );
ZonedDateTime zdt = ZonedDateTime.parse( input , f );
zdt.toString(): 2013-06-01T12:53:10+05:30[Asia/Kolkata]
About java.time
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?
- Java SE 8, Java SE 9, Java SE 10, and later
- Built-in.
- Part of the standard Java API with a bundled implementation.
- Java 9 adds some minor features and fixes.
- Java SE 6 and Java SE 7
- Much of the java.time functionality is back-ported to Java 6 & 7 in ThreeTen-Backport.
- Android
- Later versions of Android bundle implementations of the java.time classes.
- For earlier Android (<26), the ThreeTenABP project adapts ThreeTen-Backport (mentioned above). See How to use ThreeTenABP….
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.
Fixed point vs Floating point number
The term ‘fixed point’ refers to the corresponding manner in which numbers are represented, with a fixed number of digits after, and sometimes before, the decimal point. With floating-point representation, the placement of the decimal point can ‘float’ relative to the significant digits of the number. For example, a fixed-point representation with a uniform decimal point placement convention can represent the numbers 123.45, 1234.56, 12345.67, etc, whereas a floating-point representation could in addition represent 1.234567, 123456.7, 0.00001234567, 1234567000000000, etc.
How do I use T-SQL's Case/When?
declare @n int = 7,
@m int = 3;
select
case
when @n = 1 then
'SOMETEXT'
else
case
when @m = 1 then
'SOMEOTHERTEXT'
when @m = 2 then
'SOMEOTHERTEXTGOESHERE'
end
end as col1
-- n=1 => returns SOMETEXT regardless of @m
-- n=2 and m=1 => returns SOMEOTHERTEXT
-- n=2 and m=2 => returns SOMEOTHERTEXTGOESHERE
-- n=2 and m>2 => returns null (no else defined for inner case)
How to create JNDI context in Spring Boot with Embedded Tomcat Container
I recently had the requirement to use JNDI with an embedded Tomcat in Spring Boot.
Actual answers give some interesting hints to solve my task but it was not enough as probably not updated for Spring Boot 2.
Here is my contribution tested with Spring Boot 2.0.3.RELEASE.
Specifying a datasource available in the classpath at runtime
You have multiple choices :
- using the DBCP 2 datasource (you don't want to use DBCP 1 that is outdated and less efficient).
- using the Tomcat JDBC datasource.
- using any other datasource : for example HikariCP.
If you don't specify anyone of them, with the default configuration the instantiation of the datasource will throw an exception :
Caused by: javax.naming.NamingException: Could not create resource factory instance
at org.apache.naming.factory.ResourceFactory.getDefaultFactory(ResourceFactory.java:50)
at org.apache.naming.factory.FactoryBase.getObjectInstance(FactoryBase.java:90)
at javax.naming.spi.NamingManager.getObjectInstance(NamingManager.java:321)
at org.apache.naming.NamingContext.lookup(NamingContext.java:839)
at org.apache.naming.NamingContext.lookup(NamingContext.java:159)
at org.apache.naming.NamingContext.lookup(NamingContext.java:827)
at org.apache.naming.NamingContext.lookup(NamingContext.java:159)
at org.apache.naming.NamingContext.lookup(NamingContext.java:827)
at org.apache.naming.NamingContext.lookup(NamingContext.java:159)
at org.apache.naming.NamingContext.lookup(NamingContext.java:827)
at org.apache.naming.NamingContext.lookup(NamingContext.java:173)
at org.apache.naming.SelectorContext.lookup(SelectorContext.java:163)
at javax.naming.InitialContext.lookup(InitialContext.java:417)
at org.springframework.jndi.JndiTemplate.lambda$lookup$0(JndiTemplate.java:156)
at org.springframework.jndi.JndiTemplate.execute(JndiTemplate.java:91)
at org.springframework.jndi.JndiTemplate.lookup(JndiTemplate.java:156)
at org.springframework.jndi.JndiTemplate.lookup(JndiTemplate.java:178)
at org.springframework.jndi.JndiLocatorSupport.lookup(JndiLocatorSupport.java:96)
at org.springframework.jndi.JndiObjectLocator.lookup(JndiObjectLocator.java:114)
at org.springframework.jndi.JndiObjectTargetSource.getTarget(JndiObjectTargetSource.java:140)
... 39 common frames omitted
Caused by: java.lang.ClassNotFoundException: org.apache.tomcat.dbcp.dbcp2.BasicDataSourceFactory
at java.net.URLClassLoader.findClass(URLClassLoader.java:381)
at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:331)
at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:264)
at org.apache.naming.factory.ResourceFactory.getDefaultFactory(ResourceFactory.java:47)
... 58 common frames omitted
To use Apache JDBC datasource, you don't need to add any dependency but you have to change the default factory class to
org.apache.tomcat.jdbc.pool.DataSourceFactory.
You can do it in the resource declaration :resource.setProperty("factory", "org.apache.tomcat.jdbc.pool.DataSourceFactory");I will explain below where add this line.To use DBCP 2 datasource a dependency is required:
<dependency> <groupId>org.apache.tomcat</groupId> <artifactId>tomcat-dbcp</artifactId> <version>8.5.4</version> </dependency>
Of course, adapt the artifact version according to your Spring Boot Tomcat embedded version.
To use HikariCP, add the required dependency if not already present in your configuration (it may be if you rely on persistence starters of Spring Boot) such as :
<dependency> <groupId>com.zaxxer</groupId> <artifactId>HikariCP</artifactId> <version>3.1.0</version> </dependency>
and specify the factory that goes with in the resource declaration:
resource.setProperty("factory", "com.zaxxer.hikari.HikariJNDIFactory");
Datasource configuration/declaration
You have to customize the bean that creates the TomcatServletWebServerFactory instance.
Two things to do :
enabling the JNDI naming which is disabled by default
creating and add the JNDI resource(s) in the server context
For example with PostgreSQL and a DBCP 2 datasource, do that :
@Bean
public TomcatServletWebServerFactory tomcatFactory() {
return new TomcatServletWebServerFactory() {
@Override
protected TomcatWebServer getTomcatWebServer(org.apache.catalina.startup.Tomcat tomcat) {
tomcat.enableNaming();
return super.getTomcatWebServer(tomcat);
}
@Override
protected void postProcessContext(Context context) {
// context
ContextResource resource = new ContextResource();
resource.setName("jdbc/myJndiResource");
resource.setType(DataSource.class.getName());
resource.setProperty("driverClassName", "org.postgresql.Driver");
resource.setProperty("url", "jdbc:postgresql://hostname:port/dbname");
resource.setProperty("username", "username");
resource.setProperty("password", "password");
context.getNamingResources()
.addResource(resource);
}
};
}
Here the variants for Tomcat JDBC and HikariCP datasource.
In postProcessContext() set the factory property as explained early for Tomcat JDBC ds :
@Override
protected void postProcessContext(Context context) {
ContextResource resource = new ContextResource();
//...
resource.setProperty("factory", "org.apache.tomcat.jdbc.pool.DataSourceFactory");
//...
context.getNamingResources()
.addResource(resource);
}
};
and for HikariCP :
@Override
protected void postProcessContext(Context context) {
ContextResource resource = new ContextResource();
//...
resource.setProperty("factory", "com.zaxxer.hikari.HikariDataSource");
//...
context.getNamingResources()
.addResource(resource);
}
};
Using/Injecting the datasource
You should now be able to lookup the JNDI ressource anywhere by using a standard InitialContext instance :
InitialContext initialContext = new InitialContext();
DataSource datasource = (DataSource) initialContext.lookup("java:comp/env/jdbc/myJndiResource");
You can also use JndiObjectFactoryBean of Spring to lookup up the resource :
JndiObjectFactoryBean bean = new JndiObjectFactoryBean();
bean.setJndiName("java:comp/env/jdbc/myJndiResource");
bean.afterPropertiesSet();
DataSource object = (DataSource) bean.getObject();
To take advantage of the DI container you can also make the DataSource a Spring bean :
@Bean(destroyMethod = "")
public DataSource jndiDataSource() throws IllegalArgumentException, NamingException {
JndiObjectFactoryBean bean = new JndiObjectFactoryBean();
bean.setJndiName("java:comp/env/jdbc/myJndiResource");
bean.afterPropertiesSet();
return (DataSource) bean.getObject();
}
And so you can now inject the DataSource in any Spring beans such as :
@Autowired
private DataSource jndiDataSource;
Note that many examples on the internet seem to disable the lookup of the JNDI resource on startup :
bean.setJndiName("java:comp/env/jdbc/myJndiResource");
bean.setProxyInterface(DataSource.class);
bean.setLookupOnStartup(false);
bean.afterPropertiesSet();
But I think that it is helpless as it invokes just after afterPropertiesSet() that does the lookup !
Including all the jars in a directory within the Java classpath
Correct:
java -classpath "lib/*:." my.package.Program
Incorrect:
java -classpath "lib/a*.jar:." my.package.Program
java -classpath "lib/a*:." my.package.Program
java -classpath "lib/*.jar:." my.package.Program
java -classpath lib/*:. my.package.Program
How to read the value of a private field from a different class in Java?
You can use jOOR for that.
class Foo {
private final String value = "ABC";
}
class Bar {
private final Foo foo = new Foo();
public String value() {
return org.joor.Reflect
.on(this.foo)
.field("value")
.get();
}
}
class BarTest {
@Test
void accessPrivateField() {
Assertions.assertEquals(new Bar().value(), "ABC");
}
}
Runtime error: Could not load file or assembly 'System.Web.WebPages.Razor, Version=3.0.0.0
You can find it in Nuget Package Microsoft ASP.NET Web Pages Version 3.2.0
If you have a reference to an earlier version than 3.0.0.0, Delete the reference, add the reference to the correct .dll in your packages folder and make sure "Copy Local" is set to "True" in the properties of the .dll.
Then in your web.config (as mentioned by @MichaelEvanchik)
<runtime>
<assemblyBinding xmlns="urn:schemas-microsoft-com:asm.v1">
<dependentAssembly>
<assemblyIdentity name="System.Web.WebPages.Razor" PublicKeyToken="31bf3856ad364e35"/>
<bindingRedirect oldVersion="1.0.0.0-3.0.0.0" newVersion="3.0.0.0"/>
</dependentAssembly>
</assemblyBinding>
Insert an item into sorted list in Python
Use the insort function of the bisect module:
import bisect
a = [1, 2, 4, 5]
bisect.insort(a, 3)
print(a)
Output
[1, 2, 3, 4, 5]
How to automatically generate getters and setters in Android Studio
You can use AndroidAccessors Plugin of Android Studio to generate getter and setter without m as prefix to methods
Ex: mId;
Will generate getId() and setId() instead of getmId() and setmId()
Best way to get all selected checkboxes VALUES in jQuery
You want the :checkbox:checked selector and map to create an array of the values:
var checkedValues = $('input:checkbox:checked').map(function() {
return this.value;
}).get();
If your checkboxes have a shared class it would be faster to use that instead, eg. $('.mycheckboxes:checked'), or for a common name $('input[name="Foo"]:checked')
- Update -
If you don't need IE support then you can now make the map() call more succinct by using an arrow function:
var checkedValues = $('input:checkbox:checked').map((i, el) => el.value).get();
How to simulate POST request?
It would be helpful if you provided more information - e.g. what OS your using, what you want to accomplish, etc. But, generally speaking cURL is a very powerful command-line tool I frequently use (in linux) for imitating HTML requests:
For example:
curl --data "post1=value1&post2=value2&etc=valetc" http://host/resource
OR, for a RESTful API:
curl -X POST -d @file http://host/resource
You can check out more information here-> http://curl.haxx.se/
EDITs:
OK. So basically you're looking to stress test your REST server? Then cURL really isn't helpful unless you want to write your own load-testing program, even then sockets would be the way to go. I would suggest you check out Gatling. The Gatling documentation explains how to set up the tool, and from there your can run all kinds of GET, POST, PUT and DELETE requests.
Unfortunately, short of writing your own program - i.e. spawning a whole bunch of threads and inundating your REST server with different types of requests - you really have to rely on a stress/load-testing toolkit. Just using a REST client to send requests isn't going to put much stress on your server.
More EDITs
So in order to simulate a post request on a socket, you basically have to build the initial socket connection with the server. I am not a C# guy, so I can't tell you exactly how to do that; I'm sure there are 1001 C# socket tutorials on the web. With most RESTful APIs you usually need to provide a URI to tell the server what to do. For example, let's say your API manages a library, and you are using a POST request to tell the server to update information about a book with an id of '34'. Your URI might be
http://localhost/library/book/34
Therefore, you should open a connection to localhost on port 80 (or 8080, or whatever port your server is on), and pass along an HTML request header. Going with the library example above, your request header might look as follows:
POST library/book/34 HTTP/1.0\r\n
X-Requested-With: XMLHttpRequest\r\n
Content-Type: text/html\r\n
Referer: localhost\r\n
Content-length: 36\r\n\r\n
title=Learning+REST&author=Some+Name
From here, the server should shoot back a response header, followed by whatever the API is programed to tell the client - usually something to say the POST succeeded or failed. To stress test your API, you should essentially do this over and over again by creating a threaded process.
Also, if you are posting JSON data, you will have to alter your header and content accordingly. Frankly, if you are looking to do this quick and clean, I would suggest using python (or perl) which has several libraries for creating POST, PUT, GET and DELETE request, as well as POSTing and PUTing JSON data. Otherwise, you might end up doing more programming than stress testing. Hope this helps!
Android Percentage Layout Height
You could add another empty layout below that one and set them both to have the same layout weight. They should get 50% of the space each.
How to generate a git patch for a specific commit?
With my mercurial background I was going to use:
git log --patch -1 $ID > $file
But I am considering using git format-patch -1 $ID now.
How to revert the last migration?
The answer by Alasdair covers the basics
- Identify the migrations you want by
./manage.py showmigrations migrateusing the app name and the migration name
But it should be pointed out that not all migrations can be reversed. This happens if Django doesn't have a rule to do the reversal. For most changes that you automatically made migrations by ./manage.py makemigrations, the reversal will be possible. However, custom scripts will need to have both a forward and reverse written, as described in the example here:
https://docs.djangoproject.com/en/1.9/ref/migration-operations/
How to do a no-op reversal
If you had a RunPython operation, then maybe you just want to back out the migration without writing a logically rigorous reversal script. The following quick hack to the example from the docs (above link) allows this, leaving the database in the same state that it was after the migration was applied, even after reversing it.
# -*- coding: utf-8 -*-
from __future__ import unicode_literals
from django.db import migrations, models
def forwards_func(apps, schema_editor):
# We get the model from the versioned app registry;
# if we directly import it, it'll be the wrong version
Country = apps.get_model("myapp", "Country")
db_alias = schema_editor.connection.alias
Country.objects.using(db_alias).bulk_create([
Country(name="USA", code="us"),
Country(name="France", code="fr"),
])
class Migration(migrations.Migration):
dependencies = []
operations = [
migrations.RunPython(forwards_func, lambda apps, schema_editor: None),
]
This works for Django 1.8, 1.9
Update: A better way of writing this would be to replace lambda apps, schema_editor: None with migrations.RunPython.noop in the snippet above. These are both functionally the same thing. (credit to the comments)
How can I verify if a Windows Service is running
Here you get all available services and their status in your local machine.
ServiceController[] services = ServiceController.GetServices();
foreach(ServiceController service in services)
{
Console.WriteLine(service.ServiceName+"=="+ service.Status);
}
You can Compare your service with service.name property inside loop and you get status of your service. For details go with the http://msdn.microsoft.com/en-us/library/system.serviceprocess.servicecontroller.aspx also http://msdn.microsoft.com/en-us/library/microsoft.windows.design.servicemanager(v=vs.90).aspx
Reading a UTF8 CSV file with Python
Using codecs.open as Alex Martelli suggested proved to be useful to me.
import codecs
delimiter = ';'
reader = codecs.open("your_filename.csv", 'r', encoding='utf-8')
for line in reader:
row = line.split(delimiter)
# do something with your row ...
imagecreatefromjpeg and similar functions are not working in PHP
sudo apt-get install phpx.x-gd
sudo service apache2 restart
x.x is the versión php.
Converting String to Double in Android
I would do it this way:
try {
txtProt = (EditText) findViewById(R.id.Protein); // Same
p = txtProt.getText().toString(); // Same
protein = Double.parseDouble(p); // Make use of autoboxing. It's also easier to read.
} catch (NumberFormatException e) {
// p did not contain a valid double
}
EDIT: "the program force closes immediately without leaving any info in the logcat"
I don't know bout not leaving information in the logcat output, but a force-close generally means there's an uncaught exception - like a NumberFormatException.
What is the best way to dump entire objects to a log in C#?
You could base something on the ObjectDumper code that ships with the Linq samples.
Have also a look at the answer of this related question to get a sample.
Vim 80 column layout concerns
this one is out of left field but its a nice little map for resizing your current split to 80 characters if you've got the line numbers on:
" make window 80 + some for numbers wide
noremap <Leader>w :let @w=float2nr(log10(line("$")))+82\|:vertical resize <c-r>w<cr>
Twitter API returns error 215, Bad Authentication Data
The url with /1.1/ in it is correct, it is the new Twitter API Version 1.1.
But you need an application and authorize your application (and the user) using oAuth.
Read more about this on the Twitter Developers documentation site :)
In jQuery how can I set "top,left" properties of an element with position values relative to the parent and not the document?
Code offset dynamic for dynamic page
var pos=$('#send').offset().top;
$('#loading').offset({ top : pos-220});
How can I show the table structure in SQL Server query?
For SQL Server, if using a newer version, you can use
select *
from INFORMATION_SCHEMA.COLUMNS
where TABLE_NAME='tableName'
There are different ways to get the schema. Using ADO.NET, you can use the schema methods. Use the DbConnection's GetSchema method or the DataReader'sGetSchemaTable method.
Provided that you have a reader for the for the query, you can do something like this:
using(DbCommand cmd = ...)
using(var reader = cmd.ExecuteReader())
{
var schema = reader.GetSchemaTable();
foreach(DataRow row in schema.Rows)
{
Debug.WriteLine(row["ColumnName"] + " - " + row["DataTypeName"])
}
}
See this article for further details.
Javascript variable access in HTML
It is also possible to use span tag instead of a tag:
<html>
<script>
var simpleText = "hello_world";
var finalSplitText = simpleText.split("_");
var splitText = finalSplitText[0];
document.getElementById('someId').InnerHTML = splitText;
</script>
<body>
<span id="someId"></span>
</body>
</html>
It worked well for me
Xampp MySQL not starting - "Attempting to start MySQL service..."
If you have other testing applications like SQL web batch etc, uninstall them because they are running in port 3306.
How to delete columns in pyspark dataframe
You could either explicitly name the columns you want to keep, like so:
keep = [a.id, a.julian_date, a.user_id, b.quan_created_money, b.quan_created_cnt]
Or in a more general approach you'd include all columns except for a specific one via a list comprehension. For example like this (excluding the id column from b):
keep = [a[c] for c in a.columns] + [b[c] for c in b.columns if c != 'id']
Finally you make a selection on your join result:
d = a.join(b, a.id==b.id, 'outer').select(*keep)
Why should I use a container div in HTML?
This is one of the biggest bad habits perpetrated by front end coders.
All the answers above me are wrong. The body does take a width, margins, borders, etc and should act as your initial container. The html element should act as your background "canvas" as it was intended. In dozens of sites I've done I've only had to use a container div once.
I'd be willing to be that these same coders using container divs are also littering their markup with divs inside of divs--everywhere else.
Dont' do it. Use divs sparingly and aim for lean markup.
-=-=- UPDATE - Not sure what's wrong with SO because I can edit this answer from 5 years ago but I can't reply to the comments as it says I need 50 Rep before I can do so. Accordingly, I'll add my answer to the replies it received here. -=-=-
I just found this, years after my answer, and see that there are some follow up replies. And, surely you jest?
The installed placeholder site you found for my domain, which I never claimed was my markup or styling, or even mentioned in my post, was very clearly a basic CMS install with not one word of content (it said as much on the homepage). That was not my markup and styling. That was the Silverstripe default template. And I take no credit for it. It is, though, perhaps one of only two examples I can think of that would necessitate a container div.
Example 1: A generic template designed to accommodate unknowns. In this case you were seeing a default CMS template that had divs inside of divs inside of divs.
The horror.
Example 2: A three column layout to get the footer to clear properly (I think this was probably the scenario I had that needed a container div, hard to remember because that was years ago.)
I did just build (not even finished yet) a theme for my domain and started loading content. For this easily achieved example of semantic markup, click the link.
Frankly, I'm baffled that people think you actually need a container div and start with one before ever even trying just a body. The body, as I heard it explained once by one of the original authors of the CSS spec, was intended as the "initial container".
Markup should be added as needed, not because thats just the way you've seen it done.
Best way to get value from Collection by index
It would be just as convenient to simply convert your collection into a list whenever it updates. But if you are initializing, this will suffice:
for(String i : collectionlist){
arraylist.add(i);
whateverIntID = arraylist.indexOf(i);
}
Be open-minded.
Reading string by char till end of line C/C++
The answer to your original question
How to read a string one char at the time, and stop when you reach end of line?
is, in C++, very simply, namely: use getline. The link shows a simple example:
#include <iostream>
#include <string>
int main () {
std::string name;
std::cout << "Please, enter your full name: ";
std::getline (std::cin,name);
std::cout << "Hello, " << name << "!\n";
return 0;
}
Do you really want to do this in C? I wouldn't! The thing is, in C, you have to allocate the memory in which to place the characters you read in? How many characters? You don't know ahead of time. If you allocate too few characters, you will have to allocate a new buffer every time to realize you reading more characters than you made room for. If you over-allocate, you are wasting space.
C is a language for low-level programming. If you are new to programming and writing simple applications for reading files line-by-line, just use C++. It does all that memory allocation for you.
Your later questions regarding "\0" and end-of-lines in general were answered by others and do apply to C as well as C++. But if you are using C, please remember that it's not just the end-of-line that matters, but memory allocation as well. And you will have to be careful not to overrun your buffer.
Why the switch statement cannot be applied on strings?
C++
constexpr hash function:
constexpr unsigned int hash(const char *s, int off = 0) {
return !s[off] ? 5381 : (hash(s, off+1)*33) ^ s[off];
}
switch( hash(str) ){
case hash("one") : // do something
case hash("two") : // do something
}
cordova run with ios error .. Error code 65 for command: xcodebuild with args:
1) Open code in Xcode
2) Continue with : ionic cordova build ios
Java synchronized method lock on object, or method?
If you declare the method as synchronized (as you're doing by typing public synchronized void addA()) you synchronize on the whole object, so two thread accessing a different variable from this same object would block each other anyway.
If you want to synchronize only on one variable at a time, so two threads won't block each other while accessing different variables, you have synchronize on them separately in synchronized () blocks. If a and b were object references you would use:
public void addA() {
synchronized( a ) {
a++;
}
}
public void addB() {
synchronized( b ) {
b++;
}
}
But since they're primitives you can't do this.
I would suggest you to use AtomicInteger instead:
import java.util.concurrent.atomic.AtomicInteger;
class X {
AtomicInteger a;
AtomicInteger b;
public void addA(){
a.incrementAndGet();
}
public void addB(){
b.incrementAndGet();
}
}
Remove stubborn underline from link
Here is an example for the asp.net webforms LinkButton control:
<asp:LinkButton ID="lbmmr1" runat="server" ForeColor="Blue" />
Code behind:
lbmmr1.Attributes.Add("style", "text-decoration: none;")
Adding whitespace in Java
I think you are talking about padding strings with spaces.
One way to do this is with string format codes.
For example, if you want to pad a string to a certain length with spaces, use something like this:
String padded = String.format("%-20s", str);
In a formatter, % introduces a format sequence. The - means that the string will be left-justified (spaces will be added on the right of the string). The 20 means the resulting string will be 20 characters long. The s is the character string format code, and ends the format sequence.
Convert time in HH:MM:SS format to seconds only?
<?php
$time = '21:32:32';
$seconds = 0;
$parts = explode(':', $time);
if (count($parts) > 2) {
$seconds += $parts[0] * 3600;
}
$seconds += $parts[1] * 60;
$seconds += $parts[2];
Hide axis values but keep axis tick labels in matplotlib
to remove tickmarks entirely use:
ax.set_yticks([])
ax.set_xticks([])
otherwise ax.set_yticklabels([]) and ax.set_xticklabels([]) will keep tickmarks.
How to obtain Signing certificate fingerprint (SHA1) for OAuth 2.0 on Android?
For those using OpenSSL you can retrieve the SHA1 fingerprint this way:
OpenSSL> dgst -sha1 my-release-key.keystore
Which would result in the following output:
ES6 Class Multiple inheritance
Well Object.assign gives you the possibility to do something close albeit a bit more like composition with ES6 classes.
class Animal {
constructor(){
Object.assign(this, new Shark())
Object.assign(this, new Clock())
}
}
class Shark {
// only what's in constructor will be on the object, ence the weird this.bite = this.bite.
constructor(){ this.color = "black"; this.bite = this.bite }
bite(){ console.log("bite") }
eat(){ console.log('eat') }
}
class Clock{
constructor(){ this.tick = this.tick; }
tick(){ console.log("tick"); }
}
let animal = new Animal();
animal.bite();
console.log(animal.color);
animal.tick();
I've not seen this used anywhere but it's actually quite useful. You can use function shark(){} instead of class but there are advantages of using class instead.
I believe the only thing different with inheritance with extend keyword is that the function don't live only on the prototype but also the object itself.
Thus now when you do new Shark() the shark created has a bite method, while only its prototype has a eat method
How to send parameters with jquery $.get()
If you say that it works with accessing directly manageproducts.do?option=1 in the browser then it should work with:
$.get('manageproducts.do', { option: '1' }, function(data) {
...
});
as it would send the same GET request.
Save the console.log in Chrome to a file
This may or may not be helpful but on Windows you can read the console log using Event Tracing for Windows
http://msdn.microsoft.com/en-us/library/ms751538.aspx
Our integration tests are run in .NET so I use this method to add the console log to our test output. I've made a sample console project to demonstrate here: https://github.com/jkells/chrome-trace
--enable-logging --v=1 doesn't seem to work on the latest version of Chrome.
PHP check file extension
$file = $_FILES["file"] ["tmp_name"];
$check_ext = strtolower(pathinfo($file,PATHINFO_EXTENSION));
if ($check_ext == "fileext") {
//code
}
else {
//code
}
Does an HTTP Status code of 0 have any meaning?
Short Answer
It's not a HTTP response code, but it is documented by WhatWG as a valid value for the status attribute of an XMLHttpRequest or a Fetch response.
Broadly speaking, it is a default value used when there is no real HTTP status code to report and/or an error occurred sending the request or receiving the response. Possible scenarios where this is the case include, but are not limited to:
- The request hasn't yet been sent, or was aborted.
- The browser is still waiting to receive the response status and headers.
- The connection dropped during the request.
- The request timed out.
- The request encountered an infinite redirect loop.
- The browser knows the response status, but you're not allowed to access it due to security restrictions related to the Same-origin Policy.
Long Answer
First, to reiterate: 0 is not a HTTP status code. There's a complete list of them in RFC 7231 Section 6.1, that doesn't include 0, and the intro to section 6 states clearly that
The status-code element is a three-digit integer code
which 0 is not.
However, 0 as a value of the .status attribute of an XMLHttpRequest object is documented, although it's a little tricky to track down all the relevant details. We begin at https://xhr.spec.whatwg.org/#the-status-attribute, documenting the .status attribute, which simply states:
That may sound vacuous and tautological, but in reality there is information here! Remember that this documentation is talking here about the .response attribute of an XMLHttpRequest, not a response, so this tells us that the definition of the status on an XHR object is deferred to the definition of a response's status in the Fetch spec.
But what response object? What if we haven't actually received a response yet? The inline link on the word "response" takes us to https://xhr.spec.whatwg.org/#response, which explains:
An
XMLHttpRequesthas an associated response. Unless stated otherwise it is a network error.
So the response whose status we're getting is by default a network error. And by searching for everywhere the phrase "set response to" is used in the XHR spec, we can see that it's set in five places:
To a network error, when:
- the
open()method is called, or - the response's body's stream is errored (see the algorithm described in the docs for the
send()method) - the timed out flag is set, causing the request error steps to run
- the
abort()method is called, causing the request error steps to run
- the
To the response produced by sending the request using Fetch, by way of either the Fetch process response task (if the XHR request is asychronous) or the Fetch process response end-of-body task (if the XHR request is synchronous).
Looking in the Fetch standard, we can see that:
A network error is a response whose status is always
0
so we can immediately tell that we'll see a status of 0 on an XHR object in any of the cases where the XHR spec says the response should be set to a network error. (Interestingly, this includes the case where the body's stream gets "errored", which the Fetch spec tells us can happen during parsing the body after having received the status - so in theory I suppose it is possible for an XHR object to have its status set to 200, then encounter an out-of-memory error or something while receiving the body and so change its status back to 0.)
We also note in the Fetch standard that a couple of other response types exist whose status is defined to be 0, whose existence relates to cross-origin requests and the same-origin policy:
An opaque filtered response is a filtered response whose ... status is
0...An opaque-redirect filtered response is a filtered response whose ... status is
0...
(various other details about these two response types omitted).
But beyond these, there are also many cases where the Fetch algorithm (rather than the XHR spec, which we've already looked at) calls for the browser to return a network error! Indeed, the phrase "return a network error" appears 40 times in the Fetch standard. I will not try to list all 40 here, but I note that they include:
- The case where the request's scheme is unrecognised (e.g. trying to send a request to madeupscheme://foobar.com)
- The wonderfully vague instruction "When in doubt, return a network error." in the algorithms for handling ftp:// and file:// URLs
- Infinite redirects: "If request’s redirect count is twenty, return a network error."
- A bunch of CORS-related issues, such as "If httpRequest’s response tainting is not "cors" and the cross-origin resource policy check with request and response returns blocked, then return a network error."
- Connection failures: "If connection is failure, return a network error."
In other words: whenever something goes wrong other than getting a real HTTP error status code like a 500 or 400 from the server, you end up with a status attribute of 0 on your XHR object or Fetch response object in the browser. The number of possible specific causes enumerated in spec is vast.
Finally: if you're interested in the history of the spec for some reason, note that this answer was completely rewritten in 2020, and that you may be interested in the previous revision of this answer, which parsed essentially the same conclusions out of the older (and much simpler) W3 spec for XHR, before these were replaced by the more modern and more complicated WhatWG specs this answers refers to.
Printing without newline (print 'a',) prints a space, how to remove?
Either what Ant says, or accumulate into a string, then print once:
s = '';
for i in xrange(20):
s += 'a'
print s
How can I create an observable with a delay
import * as Rx from 'rxjs/Rx';
We should add the above import to make the blow code to work
Let obs = Rx.Observable
.interval(1000).take(3);
obs.subscribe(value => console.log('Subscriber: ' + value));
Auto increment in MongoDB to store sequence of Unique User ID
You can, but you should not https://web.archive.org/web/20151009224806/http://docs.mongodb.org/manual/tutorial/create-an-auto-incrementing-field/
Each object in mongo already has an id, and they are sortable in insertion order. What is wrong with getting collection of user objects, iterating over it and use this as incremented ID? Er go for kind of map-reduce job entirely
Precision String Format Specifier In Swift
@Christian Dietrich:
instead of:
var k = 1.0
for i in 1...right+1 {
k = 10.0 * k
}
let n = Double(Int(left*k)) / Double(k)
return "\(n)"
it could also be:
let k = pow(10.0, Double(right))
let n = Double(Int(left*k)) / k
return "\(n)"
[correction:] Sorry for confusion* - Of course this works with Doubles. I think, most practical (if you want digits to be rounded, not cut off) it would be something like that:
infix operator ~> {}
func ~> (left: Double, right: Int) -> Double {
if right <= 0 {
return round(left)
}
let k = pow(10.0, Double(right))
return round(left*k) / k
}
For Float only, simply replace Double with Float, pow with powf and round with roundf.
Update: I found that it is most practical to use return type Double instead of String. It works the same for String output, i.e.:
println("Pi is roughly \(3.1415926 ~> 3)")
prints: Pi is roughly 3.142
So you can use it the same way for Strings (you can even still write: println(d ~> 2)), but additionally you can also use it to round values directly, i.e.:
d = Double(slider.value) ~> 2
or whatever you need …
percentage of two int?
float percent = (n / (v * 1.0f)) *100
Installing a pip package from within a Jupyter Notebook not working
%pip install fedex #fedex = package name
in 2019.
In older versions of conda:
import sys
!{sys.executable} -m pip install fedex #fedex = package name
*note - you do need to import sys
Return list using select new in LINQ
You can do it as following:
class ProjectInfo
{
public string Name {get; set; }
public long Id {get; set; }
ProjectInfo(string n, long id)
{
name = n; Id = id;
}
}
public List<ProjectInfo> GetProjectForCombo()
{
using (MyDataContext db = new MyDataContext (DBHelper.GetConnectionString()))
{
var query = from pro in db.Projects
select new ProjectInfo(pro.ProjectName,pro.ProjectId);
return query.ToList<ProjectInfo>();
}
}
Using momentjs to convert date to epoch then back to date
http://momentjs.com/docs/#/displaying/unix-timestamp/
You get the number of unix seconds, not milliseconds!
You you need to multiply it with 1000 or using valueOf() and don't forget to use a formatter, since you are using a non ISO 8601 format. And if you forget to pass the formatter, the date will be parsed in the UTC timezone or as an invalid date.
moment("10/15/2014 9:00", "MM/DD/YYYY HH:mm").valueOf()
.NET - Get protocol, host, and port
Very similar to Holger's answer. If you need to grab the URL can do something like:
Uri uri = Context.Request.Url;
var scheme = uri.Scheme // returns http, https
var scheme2 = uri.Scheme + Uri.SchemeDelimiter; // returns http://, https://
var host = uri.Host; // return www.mywebsite.com
var port = uri.Port; // returns port number
The Uri class provides a whole range of methods, many which I have not listed.
In my instance, I needed to grab LocalHost along with the Port Number, so this is what I did:
var Uri uri = Context.Request.Url;
var host = uri.Scheme + Uri.SchemeDelimiter + uri.Host + ":" + uri.Port;
Which successfully grabbed: http://localhost:12345
How to get class object's name as a string in Javascript?
You can do it converting by the constructor to a string using .toString() :
function getObjectClass(obj){
if (typeof obj != "object" || obj === null) return false;
else return /(\w+)\(/.exec(obj.constructor.toString())[1];}
How to delete files older than X hours
-mmin is for minutes.
Try looking at the man page.
man find
for more types.
Android getText from EditText field
Sample code for How to get text from EditText.
Android Java Syntax
EditText text = (EditText)findViewById(R.id.vnosEmaila);
String value = text.getText().toString();
Kotlin Syntax
val text = findViewById<View>(R.id.vnosEmaila) as EditText
val value = text.text.toString()
Send cookies with curl
if you have Firebug installed on Firefox, just open the url. In the network panel, right-click and select Copy as cURL. You can see all curl parameters for this web call.
ASP.NET document.getElementById('<%=Control.ClientID%>'); returns null
Gotcha!
You have to use RegisterStartupScript instead of RegisterClientScriptBlock
Here My Example.
MasterPage:
<%@ Master Language="C#" AutoEventWireup="true" CodeBehind="MasterPage.master.cs"
Inherits="prueba.MasterPage" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title></title>
<script type="text/javascript">
function confirmCallBack() {
var a = document.getElementById('<%= Page.Master.FindControl("ContentPlaceHolder1").FindControl("Button1").ClientID %>');
alert(a.value);
}
</script>
<asp:ContentPlaceHolder ID="head" runat="server">
</asp:ContentPlaceHolder>
</head>
<body>
<form id="form1" runat="server">
<div>
<asp:ContentPlaceHolder ID="ContentPlaceHolder1" runat="server">
</asp:ContentPlaceHolder>
</div>
</form>
</body>
</html>
WebForm1.aspx
<%@ Page Title="" Language="C#" MasterPageFile="~/MasterPage.Master" AutoEventWireup="true"
CodeBehind="WebForm1.aspx.cs" Inherits="prueba.WebForm1" %>
<asp:Content ID="Content1" ContentPlaceHolderID="head" runat="server">
</asp:Content>
<asp:Content ID="Content2" ContentPlaceHolderID="ContentPlaceHolder1" runat="server">
<asp:Button ID="Button1" runat="server" Text="Button" />
</asp:Content>
WebForm1.aspx.cs
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
namespace prueba
{
public partial class WebForm1 : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
ClientScript.RegisterStartupScript(this.GetType(), "js", "confirmCallBack();", true);
}
}
}
Test for non-zero length string in Bash: [ -n "$var" ] or [ "$var" ]
An alternative and perhaps more transparent way of evaluating an empty environment variable is to use...
if [ "x$ENV_VARIABLE" != "x" ] ; then
echo 'ENV_VARIABLE contains something'
fi
How to use npm with ASP.NET Core
What is the right approach for doing this?
There are a lot of "right" approaches, you just have decide which one best suites your needs. It appears as though you're misunderstanding how to use node_modules...
If you're familiar with NuGet you should think of npm as its client-side counterpart. Where the node_modules directory is like the bin directory for NuGet. The idea is that this directory is just a common location for storing packages, in my opinion it is better to take a dependency on the packages you need as you have done in the package.json. Then use a task runner like Gulp for example to copy the files you need into your desired wwwroot location.
I wrote a blog post about this back in January that details npm, Gulp and a whole bunch of other details that are still relevant today. Additionally, someone called attention to my SO question I asked and ultimately answered myself here, which is probably helpful.
I created a Gist that shows the gulpfile.js as an example.
In your Startup.cs it is still important to use static files:
app.UseStaticFiles();
This will ensure that your application can access what it needs.
how to set width for PdfPCell in ItextSharp
aca definis los anchos
float[] anchoDeColumnas= new float[] {10f, 20f, 30f, 10f};
aca se los insertas a la tabla que tiene las columnas
table.setWidths(anchoDeColumnas);
Get URL query string parameters
Programming Language: PHP
// Inintialize URL to the variable
$url = 'https://www.youtube.com/watch?v=qnMxsGeDz90';
// Use parse_url() function to parse the URL
// and return an associative array which
// contains its various components
$url_components = parse_url($url);
// Use parse_str() function to parse the
// string passed via URL
parse_str($url_components['query'], $params);
// Display result
echo 'v parameter value is '.$params['v'];
This worked for me. I hope, it will also help you :)
How to fix Invalid byte 1 of 1-byte UTF-8 sequence
I had the same problem in my JSF application which was having a comment line containing some special characters in the XMHTL page. When I compared the previous version in my eclipse it had a comment,
//Some ? ? special characters found
Removed those characters and the page loaded fine. Mostly it is related to XML files, so please compare it with the working version.
Determine Whether Two Date Ranges Overlap
If the overlap itself should be calculated as well, you can use the following formula:
overlap = max(0, min(EndDate1, EndDate2) - max(StartDate1, StartDate2))
if (overlap > 0) {
...
}
C# Macro definitions in Preprocessor
There is no direct equivalent to C-style macros in C#, but inlined static methods - with or without #if/#elseif/#else pragmas - is the closest you can get:
/// <summary>
/// Prints a message when in debug mode
/// </summary>
[MethodImpl(MethodImplOptions.AggressiveInlining)]
public static unsafe void Log(object message) {
#if DEBUG
Console.WriteLine(message);
#endif
}
/// <summary>
/// Prints a formatted message when in debug mode
/// </summary>
/// <param name="format">A composite format string</param>
/// <param name="args">An array of objects to write using format</param>
[MethodImpl(MethodImplOptions.AggressiveInlining)]
public static unsafe void Log(string format, params object[] args) {
#if DEBUG
Console.WriteLine(format, args);
#endif
}
/// <summary>
/// Computes the square of a number
/// </summary>
/// <param name="x">The value</param>
/// <returns>x * x</returns>
[MethodImpl(MethodImplOptions.AggressiveInlining)]
public static double Square(double x) {
return x * x;
}
/// <summary>
/// Wipes a region of memory
/// </summary>
/// <param name="buffer">The buffer</param>
[MethodImpl(MethodImplOptions.AggressiveInlining)]
public static unsafe void ClearBuffer(ref byte[] buffer) {
ClearBuffer(ref buffer, 0, buffer.Length);
}
/// <summary>
/// Wipes a region of memory
/// </summary>
/// <param name="buffer">The buffer</param>
/// <param name="offset">Start index</param>
/// <param name="length">Number of bytes to clear</param>
[MethodImpl(MethodImplOptions.AggressiveInlining)]
public static unsafe void ClearBuffer(ref byte[] buffer, int offset, int length) {
fixed(byte* ptrBuffer = &buffer[offset]) {
for(int i = 0; i < length; ++i) {
*(ptrBuffer + i) = 0;
}
}
}
This works perfectly as a macro, but comes with a little drawback: Methods marked as inlined will be copied to the reflection part of your assembly like any other "normal" method.
Does Java support structs?
Java definitively has no structs :) But what you describe here looks like a JavaBean kind of class.
java - iterating a linked list
As the definition of Linkedlist says, it is a sequence and you are guaranteed to get the elements in order.
eg:
import java.util.LinkedList;
public class ForEachDemonstrater {
public static void main(String args[]) {
LinkedList<Character> pl = new LinkedList<Character>();
pl.add('j');
pl.add('a');
pl.add('v');
pl.add('a');
for (char s : pl)
System.out.print(s+"->");
}
}
IOCTL Linux device driver
An ioctl, which means "input-output control" is a kind of device-specific system call. There are only a few system calls in Linux (300-400), which are not enough to express all the unique functions devices may have. So a driver can define an ioctl which allows a userspace application to send it orders. However, ioctls are not very flexible and tend to get a bit cluttered (dozens of "magic numbers" which just work... or not), and can also be insecure, as you pass a buffer into the kernel - bad handling can break things easily.
An alternative is the sysfs interface, where you set up a file under /sys/ and read/write that to get information from and to the driver. An example of how to set this up:
static ssize_t mydrvr_version_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
return sprintf(buf, "%s\n", DRIVER_RELEASE);
}
static DEVICE_ATTR(version, S_IRUGO, mydrvr_version_show, NULL);
And during driver setup:
device_create_file(dev, &dev_attr_version);
You would then have a file for your device in /sys/, for example, /sys/block/myblk/version for a block driver.
Another method for heavier use is netlink, which is an IPC (inter-process communication) method to talk to your driver over a BSD socket interface. This is used, for example, by the WiFi drivers. You then communicate with it from userspace using the libnl or libnl3 libraries.
how to filter out a null value from spark dataframe
df.where(df.col("friend_id").isNull)
SQL where datetime column equals today's date?
To get all the records where record created date is today's date Use the code after WHERE clause
WHERE CAST(Submission_date AS DATE) = CAST( curdate() AS DATE)
Check if Python Package is installed
if pip list | grep -q \^'PACKAGENAME\s'
# installed ...
else
# not installed ...
fi
Collision resolution in Java HashMap
It could have formed a linked list, indeed. It's just that Map contract requires it to replace the entry:
V put(K key, V value)Associates the specified value with the specified key in this map (optional operation). If the map previously contained a mapping for the key, the old value is replaced by the specified value. (A map m is said to contain a mapping for a key k if and only if m.containsKey(k) would return true.)
http://docs.oracle.com/javase/6/docs/api/java/util/Map.html
For a map to store lists of values, it'd need to be a Multimap. Here's Google's: http://google-collections.googlecode.com/svn/trunk/javadoc/com/google/common/collect/Multimap.html
A collection similar to a Map, but which may associate multiple values with a single key. If you call put(K, V) twice, with the same key but different values, the multimap contains mappings from the key to both values.
Edit: Collision resolution
That's a bit different. A collision happens when two different keys happen to have the same hash code, or two keys with different hash codes happen to map into the same bucket in the underlying array.
Consider HashMap's source (bits and pieces removed):
public V put(K key, V value) {
int hash = hash(key.hashCode());
int i = indexFor(hash, table.length);
// i is the index where we want to insert the new element
addEntry(hash, key, value, i);
return null;
}
void addEntry(int hash, K key, V value, int bucketIndex) {
// take the entry that's already in that bucket
Entry<K,V> e = table[bucketIndex];
// and create a new one that points to the old one = linked list
table[bucketIndex] = new Entry<>(hash, key, value, e);
}
For those who are curious how the Entry class in HashMap comes to behave like a list, it turns out that HashMap defines its own static Entry class which implements Map.Entry. You can see for yourself by viewing the source code:
Why AVD Manager options are not showing in Android Studio
Should be something to do with your Platform Settings. Try the below steps
- Go to Project Structure -> Platform Settings -> SDKs
- Select available SDK's as shown in screenshots
- Re-start the Android Studio
- Android will detect the framework in the right corner. Click on it
- Then click ok as shown in second screenshot
How to link to part of the same document in Markdown?
Some more spins on the <a name=""> trick:
<a id="a-link"></a> Title
------
#### <a id="a-link"></a> Title (when you wanna control the h{N} with #'s)
How to prevent user from typing in text field without disabling the field?
If you want to prevent the user from adding anything, but provide them with the ability to erase characters:
<input value="CAN'T ADD TO THIS" maxlength="0" />Setting the maxlength attribute of an input to "0" makes it so that the user is unable to add content, but still erase content as they wish.
But If you want it to be truly constant and unchangeable:
<input value="THIS IS READONLY" onkeydown="return false" />Setting the onkeydown attribute to return false makes the input ignore user keypresses on it, thus preventing them from changing or affecting the value.
Error:Execution failed for task ':app:processDebugResources'. > java.io.IOException: Could not delete folder "" in android studio
React Native
These steps solved my problem:
- Renaming of ReactNativeApp/android/build directory to old.build
- Closing Android Studio
- Inside ReactNativeApp/android executed this command. gradlew clean
- Making sure my RAM is 1500mb free
- Then finally executing the command react-native run-android
** It's quite interesting to close Android Studio. But beleive me these steps solved my problem **
How to split a comma separated string and process in a loop using JavaScript
Try the following snippet:
var mystring = 'this,is,an,example';
var splits = mystring.split(",");
alert(splits[0]); // output: this
iOS: Modal ViewController with transparent background
This code works fine on iPhone under iOS6 and iOS7:
presentedVC.view.backgroundColor = YOUR_COLOR; // can be with 'alpha'
presentingVC.modalPresentationStyle = UIModalPresentationCurrentContext;
[presentingVC presentViewController:presentedVC animated:YES completion:NULL];
In this case you miss slide-on animation. To retain animation you still can use the following "non-elegant" extension:
[presentingVC presentViewController:presentedVC animated:YES completion:^{
[presentedVC dismissViewControllerAnimated:NO completion:^{
presentingVC.modalPresentationStyle = UIModalPresentationCurrentContext;
[presentingVC presentViewController:presentedVC animated:NO completion:NULL];
}];
}];
If our presentingV is located inside of UINavigationController or UITabbarController you need to operate with that controllers as presentingVC.
Further, in iOS7 you can implement custom transition animation applying UIViewControllerTransitioningDelegate protocol. Of course, in this case you can get transparent background
@interface ModalViewController : UIViewController <UIViewControllerTransitioningDelegate>
First, before presenting you have to set modalPresentationStyle
modalViewController.modalPresentationStyle = UIModalPresentationCustom;
Then you have to implement two protocol methods
- (id<UIViewControllerAnimatedTransitioning>)animationControllerForPresentedController:(UIViewController *)presented presentingController:(UIViewController *)presenting sourceController:(UIViewController *)source
{
CustomAnimatedTransitioning *transitioning = [CustomAnimatedTransitioning new];
transitioning.presenting = YES;
return transitioning;
}
- (id<UIViewControllerAnimatedTransitioning>)animationControllerForDismissedController:(UIViewController *)dismissed
{
CustomAnimatedTransitioning * transitioning = [CustomAnimatedTransitioning new];
transitioning.presenting = NO;
return transitioning;
}
The last thing is to define your custom transition in CustomAnimatedTransitioning class
@interface CustomAnimatedTransitioning : NSObject <UIViewControllerAnimatedTransitioning>
@property (nonatomic) BOOL presenting;
@end
@implementation CurrentContextTransitionAnimator
- (NSTimeInterval)transitionDuration:(id <UIViewControllerContextTransitioning>)transitionContext
{
return 0.25;
}
- (void)animateTransition:(id <UIViewControllerContextTransitioning>)transitionContext
{
UIViewController *fromViewController = [transitionContext viewControllerForKey:UITransitionContextFromViewControllerKey];
UIViewController *toViewController = [transitionContext viewControllerForKey:UITransitionContextToViewControllerKey];
if (self.presenting) {
// custom presenting animation
}
else {
// custom dismissing animation
}
}
How to Update/Drop a Hive Partition?
in addition, you can drop multiple partitions from one statement (Dropping multiple partitions in Impala/Hive).
Extract from above link:
hive> alter table t drop if exists partition (p=1),partition (p=2),partition(p=3);
Dropped the partition p=1
Dropped the partition p=2
Dropped the partition p=3
OK
EDIT 1:
Also, you can drop bulk using a condition sign (>,<,<>), for example:
Alter table t
drop partition (PART_COL>1);
Invalid use side-effecting operator Insert within a function
You can't use a function to insert data into a base table. Functions return data. This is listed as the very first limitation in the documentation:
User-defined functions cannot be used to perform actions that modify the database state.
"Modify the database state" includes changing any data in the database (though a table variable is an obvious exception the OP wouldn't have cared about 3 years ago - this table variable only lives for the duration of the function call and does not affect the underlying tables in any way).
You should be using a stored procedure, not a function.
ElasticSearch - Return Unique Values
I am looking for this kind of solution for my self as well. I found reference in terms aggregation.
So, according to that following is the proper solution.
{
"aggs" : {
"langs" : {
"terms" : { "field" : "language",
"size" : 500 }
}
}}
But if you ran into following error:
"error": {
"root_cause": [
{
"type": "illegal_argument_exception",
"reason": "Fielddata is disabled on text fields by default. Set fielddata=true on [fastest_method] in order to load fielddata in memory by uninverting the inverted index. Note that this can however use significant memory. Alternatively use a keyword field instead."
}
]}
In that case, you have to add "KEYWORD" in the request, like following:
{
"aggs" : {
"langs" : {
"terms" : { "field" : "language.keyword",
"size" : 500 }
}
}}
Clearing the terminal screen?
/*
As close as I can get to Clear Screen
*/
void setup() {
// put your setup code here, to run once:
Serial.begin(115200);
}
void loop() {
Serial.println("This is Line ZERO ");
// put your main code here, to run repeatedly:
for (int i = 1; i < 37; i++)
{
// Check and print Line
if (i == 15)
{
Serial.println("Line 15");
}
else
Serial.println(i); //Prints line numbers Delete i for blank line
}
delay(5000);
}
How to remove the default arrow icon from a dropdown list (select element)?
You cannot do this with a fully functional cross browser support.
Try taking a div of 50 pixels suppose and float a desired drop-down icon of your choice at the right of this
Now within that div, add the select tag with a width of 55 pixels maybe (something more than the container's width)
I think you'll get what you want.
In case you do not want any drop icon at the right, just do all the steps except for floating the image at the right. Set outline:0 on focus for the select tag. that's it
PySpark 2.0 The size or shape of a DataFrame
Add this to the your code:
import pyspark
def spark_shape(self):
return (self.count(), len(self.columns))
pyspark.sql.dataframe.DataFrame.shape = spark_shape
Then you can do
>>> df.shape()
(10000, 10)
But just remind you that .count() can be very slow for very large table that has not been persisted.
What's a decent SFTP command-line client for windows?
This little application does the job for me. I could not find another CLI based client that would access my IIS based TLS/SSL secured ftp site: http://netwinsite.com/surgeftp/sslftp.htm
Xcode 9 error: "iPhone has denied the launch request"
I got this issue recently and I found the solution for this crazy issue. This are the Scheme Issue to fix this issue follow following steps.
- Click Edit Scheme top Navigator Tab.
- Click Info on Run menu.
- On Executable dropdown select "Ask on Launch" option -> Then Close and run the build once.
This solved my problem when I got this issue.
Completely removing phpMyAdmin
I was having a similar problem. PHP was working on my sites configured by virtualmin but not for phpmyadmin. PHPMyAdmin would not execute and the file was being downloaded by the browser. Everything I was reading was saying that libapache2-mod-php5 was not installed but I knew it was... so the thing to do was to purge it and reinstall.
sudo apt-get purge libapache2-mod-php5
sudo apt-get install libapache2-mod-php5
sudo apt-get purge phpmyadmin
sudo apt-get install phpmyadmin
sudo /etc/init.d/apache2 restart
Setting property 'source' to 'org.eclipse.jst.jee.server:JSFTut' did not find a matching property
Remove the project from the server from the Server View. Then run the project under the same server.
The problem is as @BalusC told corrupt of server.xml of tomcat which is configured in the eclipse. So when you do the above process server.xml will be recreated .
Asp.net - <customErrors mode="Off"/> error when trying to access working webpage
You should only have one <system.web> in your Web.Config Configuration File.
<?xml version="1.0"?>
<configuration>
<system.web>
<customErrors mode="Off"/>
<compilation debug="true"/>
<authentication mode="None"/>
</system.web>
</configuration>
How to use img src in vue.js?
Try this:
<img v-bind:src="'/media/avatars/' + joke.avatar" />
Don't forget single quote around your path string. also in your data check you have correctly defined image variable.
joke: {
avatar: 'image.jpg'
}
A working demo here: http://jsbin.com/pivecunode/1/edit?html,js,output
Changing the current working directory in Java?
I have tried to invoke
String oldDir = System.setProperty("user.dir", currdir.getAbsolutePath());
It seems to work. But
File myFile = new File("localpath.ext");
InputStream openit = new FileInputStream(myFile);
throws a FileNotFoundException though
myFile.getAbsolutePath()
shows the correct path. I have read this. I think the problem is:
- Java knows the current directory with the new setting.
- But the file handling is done by the operation system. It does not know the new set current directory, unfortunately.
The solution may be:
File myFile = new File(System.getPropety("user.dir"), "localpath.ext");
It creates a file Object as absolute one with the current directory which is known by the JVM. But that code should be existing in a used class, it needs changing of reused codes.
~~~~JcHartmut
ASP.NET MVC: What is the purpose of @section?
@section is for defining a content are override from a shared view. Basically, it is a way for you to adjust your shared view (similar to a Master Page in Web Forms).
You might find Scott Gu's write up on this very interesting.
Edit: Based on additional question clarification
The @RenderSection syntax goes into the Shared View, such as:
<div id="sidebar">
@RenderSection("Sidebar", required: false)
</div>
This would then be placed in your view with @Section syntax:
@section Sidebar{
<!-- Content Here -->
}
In MVC3+ you can either define the Layout file to be used for the view directly or you can have a default view for all views.
Common view settings can be set in _ViewStart.cshtml which defines the default layout view similar to this:
@{
Layout = "~/Views/Shared/_Layout.cshtml";
}
You can also set the Shared View to use directly in the file, such as index.cshtml directly as shown in this snippet.
@{
ViewBag.Title = "Corporate Homepage";
ViewBag.BodyID = "page-home";
Layout = "~/Views/Shared/_Layout2.cshtml";
}
There are a variety of ways you can adjust this setting with a few more mentioned in this SO answer.
how to get last insert id after insert query in codeigniter active record
**Inside Model**
function add_info($data){
$this->db->insert('tbl_user_info',$data);
$last_id = $this->db->insert_id();
return $last_id;
}
**Inside Controller**
public function save_user_record() {
$insertId = $this->welcome_model->save_user_info($data);
echo $insertId->id;
}
ReDim Preserve to a Multi-Dimensional Array in Visual Basic 6
I stumbled across this question while hitting this road block myself. I ended up writing a piece of code real quick to handle this ReDim Preserve on a new sized array (first or last dimension). Maybe it will help others who face the same issue.
So for the usage, lets say you have your array originally set as MyArray(3,5), and you want to make the dimensions (first too!) larger, lets just say to MyArray(10,20). You would be used to doing something like this right?
ReDim Preserve MyArray(10,20) '<-- Returns Error
But unfortunately that returns an error because you tried to change the size of the first dimension. So with my function, you would just do something like this instead:
MyArray = ReDimPreserve(MyArray,10,20)
Now the array is larger, and the data is preserved. Your ReDim Preserve for a Multi-Dimension array is complete. :)
And last but not least, the miraculous function: ReDimPreserve()
'redim preserve both dimensions for a multidimension array *ONLY
Public Function ReDimPreserve(aArrayToPreserve,nNewFirstUBound,nNewLastUBound)
ReDimPreserve = False
'check if its in array first
If IsArray(aArrayToPreserve) Then
'create new array
ReDim aPreservedArray(nNewFirstUBound,nNewLastUBound)
'get old lBound/uBound
nOldFirstUBound = uBound(aArrayToPreserve,1)
nOldLastUBound = uBound(aArrayToPreserve,2)
'loop through first
For nFirst = lBound(aArrayToPreserve,1) to nNewFirstUBound
For nLast = lBound(aArrayToPreserve,2) to nNewLastUBound
'if its in range, then append to new array the same way
If nOldFirstUBound >= nFirst And nOldLastUBound >= nLast Then
aPreservedArray(nFirst,nLast) = aArrayToPreserve(nFirst,nLast)
End If
Next
Next
'return the array redimmed
If IsArray(aPreservedArray) Then ReDimPreserve = aPreservedArray
End If
End Function
I wrote this in like 20 minutes, so there's no guarantees. But if you would like to use or extend it, feel free. I would've thought that someone would've had some code like this up here already, well apparently not. So here ya go fellow gearheads.
Is there a date format to display the day of the week in java?
tl;dr
LocalDate.of( 2018 , Month.JANUARY , 23 )
.format( DateTimeFormatter.ofPattern( “uuuu-MM-EEE” , Locale.US ) )
java.time
The modern approach uses the java.time classes.
LocalDate ld = LocalDate.of( 2018 , Month.JANUARY , 23 ) ;
Note how we specify a Locale such as Locale.CANADA_FRENCH to determine the human language used to translate the name of the day.
DateTimeFormatter f = DateTimeFormatter.ofPattern( “uuuu-MM-EEE” , Locale.US ) ;
String output = ld.format( f ) ;
ISO 8601
By the way, you may be interested in the standard ISO 8601 week numbering scheme: yyyy-Www-d.
2018-W01-2
Week # 1 has the first Thursday of the calendar-year. Week starts on a Monday. A year has either 52 or 53 weeks. The last/first few days of a calendar-year may land in the next/previous week-based-year.
The single digit on the end is day-of-week, 1-7 for Monday-Sunday.
Add the ThreeTen-Extra library class to your project for the YearWeek class.
About java.time
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.
Where to obtain the java.time classes?
- Java SE 8, Java SE 9, and later
- Built-in.
- Part of the standard Java API with a bundled implementation.
- Java 9 adds some minor features and fixes.
- Java SE 6 and Java SE 7
- Much of the java.time functionality is back-ported to Java 6 & 7 in ThreeTen-Backport.
- Android
- Later versions of Android bundle implementations of the java.time classes.
- For earlier Android, the ThreeTenABP project adapts ThreeTen-Backport (mentioned above). See How to use ThreeTenABP….
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.
How can I access iframe elements with Javascript?
If you have the HTML
<form name="formname" .... id="form-first">
<iframe id="one" src="iframe2.html">
</iframe>
</form>
and JavaScript
function iframeRef( frameRef ) {
return frameRef.contentWindow
? frameRef.contentWindow.document
: frameRef.contentDocument
}
var inside = iframeRef( document.getElementById('one') )
inside is now a reference to the document, so you can do getElementsByTagName('textarea') and whatever you like, depending on what's inside the iframe src.
public static const in TypeScript
Meanwhile this can be solved through a decorator in combination with Object.freeze or Object.defineProperty, I'm using this, it's a little bit prettier than using tons of getters. You can copy/paste this directly TS Playground to see it in action. - There are two options
Make individual fields "final"
The following decorator converts both, annotated static and non-static fields to "getter-only-properties".
Note: If an instance-variable with no initial value is annotated @final, then the first assigned value (no matter when) will be the final one.
// example
class MyClass {
@final
public finalProp: string = "You shall not change me!";
@final
public static FINAL_FIELD: number = 75;
public static NON_FINAL: string = "I am not final."
}
var myInstance: MyClass = new MyClass();
myInstance.finalProp = "Was I changed?";
MyClass.FINAL_FIELD = 123;
MyClass.NON_FINAL = "I was changed.";
console.log(myInstance.finalProp); // => You shall not change me!
console.log(MyClass.FINAL_FIELD); // => 75
console.log(MyClass.NON_FINAL); // => I was changed.
The Decorator: Make sure you include this in your code!
/**
* Turns static and non-static fields into getter-only, and therefor renders them "final".
* To use simply annotate the static or non-static field with: @final
*/
function final(target: any, propertyKey: string) {
const value: any = target[propertyKey];
// if it currently has no value, then wait for the first setter-call
// usually the case with non-static fields
if (!value) {
Object.defineProperty(target, propertyKey, {
set: function (value: any) {
Object.defineProperty(this, propertyKey, {
get: function () {
return value;
},
enumerable: true,
configurable: false
});
},
enumerable: true,
configurable: true
});
} else { // else, set it immediatly
Object.defineProperty(target, propertyKey, {
get: function () {
return value;
},
enumerable: true
});
}
}
As an alternative to the decorator above, there would also be a strict version of this, which would even throw an Error when someone tried to assign some value to the field with "use strict"; being set. (This is only the static part though)
/**
* Turns static fields into getter-only, and therefor renders them "final".
* Also throws an error in strict mode if the value is tried to be touched.
* To use simply annotate the static field with: @strictFinal
*/
function strictFinal(target: any, propertyKey: string) {
Object.defineProperty(target, propertyKey, {
value: target[propertyKey],
writable: false,
enumerable: true
});
}
Make every static field "final"
Possible Downside: This will only work for ALL statics of that class or for none, but cannot be applied to specific statics.
/**
* Freezes the annotated class, making every static 'final'.
* Usage:
* @StaticsFinal
* class MyClass {
* public static SOME_STATIC: string = "SOME_STATIC";
* //...
* }
*/
function StaticsFinal(target: any) {
Object.freeze(target);
}
// Usage here
@StaticsFinal
class FreezeMe {
public static FROZEN_STATIC: string = "I am frozen";
}
class EditMyStuff {
public static NON_FROZEN_STATIC: string = "I am frozen";
}
// Test here
FreezeMe.FROZEN_STATIC = "I am not frozen.";
EditMyStuff.NON_FROZEN_STATIC = "I am not frozen.";
console.log(FreezeMe.FROZEN_STATIC); // => "I am frozen."
console.log(EditMyStuff.NON_FROZEN_STATIC); // => "I am not frozen."
rmagick gem install "Can't find Magick-config"
imagemagick@6 works for me!
brew unlink imagemagick
brew install imagemagick@6 && brew link imagemagick@6 --force
See this thread
Getting "Skipping JaCoCo execution due to missing execution data file" upon executing JaCoCo
I faced a bit of a different issue that returned the same error.
Skipping JaCoCo execution due to missing execution data /target/jacoco.exec
The truth is, this error is returned for many, many reasons. We experimented with the different solutions on Stack Overflow, but found this resource to be best. It tears down the many different potential reasons why Jacoco could be returning the same error.
For us, the solution was to add a prepare-agent to the configuration.
<execution>
<id>default-prepare-agent</id>
<goals>
<goal>prepare-agent</goal>
</goals>
</execution>
I would imagine most users will be experiencing it for different reasons, so take a look at the aforementioned resource!
JPA Native Query select and cast object
When your native query is based on joins, in that case you can get the result as list of objects and process it.
one simple example.
@Autowired
EntityManager em;
String nativeQuery = "select name,age from users where id=?";
Query query = em.createNativeQuery(nativeQuery);
query.setParameter(1,id);
List<Object[]> list = query.getResultList();
for(Object[] q1 : list){
String name = q1[0].toString();
//..
//do something more on
}
SQL Server default character encoding
If you need to know the default collation for a newly created database use:
SELECT SERVERPROPERTY('Collation')
This is the server collation for the SQL Server instance that you are running.
error C2220: warning treated as error - no 'object' file generated
The error says that a warning was treated as an error, therefore your problem is a warning message! The object file is then not created because there was an error. So you need to check your warnings and fix them.
In case you don't know how to find them: Open the Error List (View > Error List) and click on Warning.
Why do I get AttributeError: 'NoneType' object has no attribute 'something'?
Others have explained what NoneType is and a common way of ending up with it (i.e., failure to return a value from a function).
Another common reason you have None where you don't expect it is assignment of an in-place operation on a mutable object. For example:
mylist = mylist.sort()
The sort() method of a list sorts the list in-place, that is, mylist is modified. But the actual return value of the method is None and not the list sorted. So you've just assigned None to mylist. If you next try to do, say, mylist.append(1) Python will give you this error.
Remove the last three characters from a string
Easy. text = text.remove(text.length - 3). I subtracted 3 because the Remove function removes all items from that index to the end of the string which is text.length. So if I subtract 3 then I get the string with 3 characters removed from it.
You can generalize this to removing a characters from the end of the string, like this:
text = text.remove(text.length - a)
So what I did was the same logic. The remove function removes all items from its inside to the end of the string which is the length of the text. So if I subtract a from the length of the string that will give me the string with a characters removed.
So it doesn't just work for 3, it works for all positive integers, except if the length of the string is less than or equal to a, in that case it will return a negative number or 0.
ERROR 1044 (42000): Access denied for 'root' With All Privileges
The reason i could not delete some of the users via 'drop' statement was that there is a bug in Mysql http://bugs.mysql.com/bug.php?id=62255 with hostname containing upper case letters. The solution was running following query:
DELETE FROM mysql.user where host='Some_Host_With_UpperCase_Letters';
I am still trying to figure the other issue where the root user with all permissions are unable to grant privileges to new user for particular database
How to generate random number in Bash?
I wrote several articles on this.
- https://linuxconfig.org/generating-random-numbers-in-bash-with-examples
- https://linuxconfig.org/random-entropy-in-bash
- https://www.cloudsavvyit.com/7572/how-to-generate-better-random-numbers-at-the-bash-command-line/
$ RANDOM=$(date +%s%N | cut -b10-19)
$ echo $(( $RANDOM % 113 + 13 ))
The above will give a number between 13 and 113, with reasonable random entropy.
Get all column names of a DataTable into string array using (LINQ/Predicate)
Use
var arrayNames = (from DataColumn x in dt.Columns
select x.ColumnName).ToArray();
How do I exit a while loop in Java?
You can use "break" to break the loop, which will not allow the loop to process more conditions
How do I update Anaconda?
Here's the best practice (in my humble experience). Selecting these four packages will also update all other dependencies to the appropriate versions that will help you keep your environment consistent. The latter is a common problem others have expressed in earlier responses. This solution doesn't need the terminal.
Python: download a file from an FTP server
Use urllib2. For more specifics, check out this example from doc.python.org:
Here's a snippet from the tutorial that may help
import urllib2
req = urllib2.Request('ftp://example.com')
response = urllib2.urlopen(req)
the_page = response.read()
How to detect incoming calls, in an Android device?
@Gabe Sechan, thanks for your code. It works fine except the onOutgoingCallEnded(). It is never executed. Testing phones are Samsung S5 & Trendy. There are 2 bugs I think.
1: a pair of brackets is missing.
case TelephonyManager.CALL_STATE_IDLE:
// Went to idle- this is the end of a call. What type depends on previous state(s)
if (lastState == TelephonyManager.CALL_STATE_RINGING) {
// Ring but no pickup- a miss
onMissedCall(context, savedNumber, callStartTime);
} else {
// this one is missing
if(isIncoming){
onIncomingCallEnded(context, savedNumber, callStartTime, new Date());
} else {
onOutgoingCallEnded(context, savedNumber, callStartTime, new Date());
}
}
// this one is missing
break;
2: lastState is not updated by the state if it is at the end of the function. It should be replaced to the first line of this function by
public void onCallStateChanged(Context context, int state, String number) {
int lastStateTemp = lastState;
lastState = state;
// todo replace all the "lastState" by lastStateTemp from here.
if (lastStateTemp == state) {
//No change, debounce extras
return;
}
//....
}
Additional I've put lastState and savedNumber into shared preference as you suggested.
Just tested it with above changes. Bug fixed at least on my phones.
Using sed, Insert a line above or below the pattern?
Insert a new verse after the given verse in your stanza:
sed -i '/^lorem ipsum dolor sit amet$/ s:$:\nconsectetur adipiscing elit:' FILE
how to convert java string to Date object
"mm" means the "minutes" fragment of a date. For the "months" part, use "MM".
So, try to change the code to:
DateFormat df = new SimpleDateFormat("MM/dd/yyyy");
Date startDate = df.parse(startDateString);
Edit: A DateFormat object contains a date formatting definition, not a Date object, which contains only the date without concerning about formatting. When talking about formatting, we are talking about create a String representation of a Date in a specific format. See this example:
import java.text.DateFormat;
import java.text.SimpleDateFormat;
import java.util.Date;
public class DateTest {
public static void main(String[] args) throws Exception {
String startDateString = "06/27/2007";
// This object can interpret strings representing dates in the format MM/dd/yyyy
DateFormat df = new SimpleDateFormat("MM/dd/yyyy");
// Convert from String to Date
Date startDate = df.parse(startDateString);
// Print the date, with the default formatting.
// Here, the important thing to note is that the parts of the date
// were correctly interpreted, such as day, month, year etc.
System.out.println("Date, with the default formatting: " + startDate);
// Once converted to a Date object, you can convert
// back to a String using any desired format.
String startDateString1 = df.format(startDate);
System.out.println("Date in format MM/dd/yyyy: " + startDateString1);
// Converting to String again, using an alternative format
DateFormat df2 = new SimpleDateFormat("dd/MM/yyyy");
String startDateString2 = df2.format(startDate);
System.out.println("Date in format dd/MM/yyyy: " + startDateString2);
}
}
Output:
Date, with the default formatting: Wed Jun 27 00:00:00 BRT 2007
Date in format MM/dd/yyyy: 06/27/2007
Date in format dd/MM/yyyy: 27/06/2007
Convert Iterator to ArrayList
use google guava !
Iterable<String> fieldsIterable = ...
List<String> fields = Lists.newArrayList(fieldsIterable);
++
Put text at bottom of div
If you only have one line of text and your div has a fixed height, you can do this:
div {
line-height: (2*height - font-size);
text-align: right;
}
See fiddle.
How to turn IDENTITY_INSERT on and off using SQL Server 2008?
I had a problem where it did not allow me to insert it even after setting the IDENTITY_INSERT ON.
The problem was that i did not specify the column names and for some reason it did not like it.
INSERT INTO tbl Values(vals)
So basically do the full INSERT INTO tbl(cols) Values(vals)
Highcharts - how to have a chart with dynamic height?
When using percentage, the height it relative to the width and will dynamically change along with it:
chart: {
height: (9 / 16 * 100) + '%' // 16:9 ratio
},
String to object in JS
I implemented a solution in a few lines of code which works quite reliably.
Having an HTML element like this where I want to pass custom options:
<div class="my-element"
data-options="background-color: #dadada; custom-key: custom-value;">
</div>
a function parses the custom options and return an object to use that somewhere:
function readCustomOptions($elem){
var i, len, option, options, optionsObject = {};
options = $elem.data('options');
options = (options || '').replace(/\s/g,'').split(';');
for (i = 0, len = options.length - 1; i < len; i++){
option = options[i].split(':');
optionsObject[option[0]] = option[1];
}
return optionsObject;
}
console.log(readCustomOptions($('.my-element')));
Fastest way to duplicate an array in JavaScript - slice vs. 'for' loop
ECMAScript 2015 way with the Spread operator:
Basic examples:
var copyOfOldArray = [...oldArray]
var twoArraysBecomeOne = [...firstArray, ..seccondArray]
Try in the browser console:
var oldArray = [1, 2, 3]
var copyOfOldArray = [...oldArray]
console.log(oldArray)
console.log(copyOfOldArray)
var firstArray = [5, 6, 7]
var seccondArray = ["a", "b", "c"]
var twoArraysBecomOne = [...firstArray, ...seccondArray]
console.log(twoArraysBecomOne);
References
I need to know how to get my program to output the word i typed in and also the new rearranged word using a 2D array
- What exactly doesn't work?
- Why are you using a 2d array?
If you must use a 2d array:
int numOfPairs = 10; String[][] array = new String[numOfPairs][2]; for(int i = 0; i < array.length; i++){ for(int j = 0; j < array[i].length; j++){ array[i] = new String[2]; array[i][0] = "original word"; array[i][1] = "rearranged word"; } }
Does this give you a hint?
IOS: verify if a point is inside a rect
UIView's pointInside:withEvent: could be a good solution. Will return a boolean value indicating wether or not the given CGPoint is in the UIView instance you are using. Example:
UIView *aView = [UIView alloc]initWithFrame:CGRectMake(0,0,100,100);
CGPoint aPoint = CGPointMake(5,5);
BOOL isPointInsideView = [aView pointInside:aPoint withEvent:nil];
Why doesn't the Scanner class have a nextChar method?
The Scanner class is bases on logic implemented in String next(Pattern) method. The additional API method like nextDouble() or nextFloat(). Provide the pattern inside.
Then class description says:
A simple text scanner which can parse primitive types and strings using regular expressions.
A Scanner breaks its input into tokens using a delimiter pattern, which by default matches whitespace. The resulting tokens may then be converted into values of different types using the various next methods.
From the description it can be sad that someone has forgot about char as it is a primitive type for sure.
But the concept of class is to find patterns, a char has no pattern is just next character. And this logic IMHO caused that nextChar has not been implemented.
If you need to read a filed char by char you can used more efficient class.
How to create friendly URL in php?
It's actually not PHP, it's apache using mod_rewrite. What happens is the person requests the link, www.example.com/profile/12345 and then apache chops it up using a rewrite rule making it look like this, www.example.com/profile.php?u=12345, to the server. You can find more here: Rewrite Guide
Only one expression can be specified in the select list when the subquery is not introduced with EXISTS
It's complaining about
COUNT(DISTINCT dNum) AS ud
inside the subquery. Only one column can be returned from the subquery unless you are performing an exists query. I'm not sure why you want to do a count on the same column twice, superficially it looks redundant to what you are doing. The subquery here is only a filter it is not the same as a join. i.e. you use it to restrict data, not to specify what columns to get back.
Disable hover effects on mobile browsers
My solution is to add hover-active css class to the HTML tag, and use it on the beginning of all the CSS selectors with :hover and remove that class on the first touchstart event.
http://codepen.io/Bnaya/pen/EoJlb
JS:
(function () {
'use strict';
if (!('addEventListener' in window)) {
return;
}
var htmlElement = document.querySelector('html');
function touchStart () {
document.querySelector('html').classList.remove('hover-active');
htmlElement.removeEventListener('touchstart', touchStart);
}
htmlElement.addEventListener('touchstart', touchStart);
}());
HTML:
<html class="hover-active">
CSS:
.hover-active .mybutton:hover {
box-shadow: 1px 1px 1px #000;
}
Error message 'Unable to load one or more of the requested types. Retrieve the LoaderExceptions property for more information.'
Verify that each of your projects is setup correctly in the Configuration Manager.
Similar to William Edmondson's reason for this issue, I switched my Configuration Manager setting from "Debug" "Any CPU" to "Debug" ".NET". The problem was that the ".NET" version was NOT configured to build ALL of the projects, so some of my DLLs were out of date (while others were current). This caused numerous problems with starting the application.
The temporary fix was to do Kenny Eliasson's suggestion to clean out the \bin and \obj directories. However, as soon as I made more changes to the non-compiling projects, everything would fail again.
How do I use 3DES encryption/decryption in Java?
Here's a very simply static encrypt/decrypt class biased on the Bouncy Castle no padding example by Jose Luis Montes de Oca. This one is using "DESede/ECB/PKCS7Padding" so I don't have to bother manually padding.
package com.zenimax.encryption;
import java.security.InvalidKeyException;
import java.security.NoSuchAlgorithmException;
import java.security.NoSuchProviderException;
import java.security.Security;
import javax.crypto.BadPaddingException;
import javax.crypto.Cipher;
import javax.crypto.IllegalBlockSizeException;
import javax.crypto.NoSuchPaddingException;
import javax.crypto.SecretKey;
import javax.crypto.spec.SecretKeySpec;
import org.bouncycastle.jce.provider.BouncyCastleProvider;
/**
*
* @author Matthew H. Wagner
*/
public class TripleDesBouncyCastle {
private static String TRIPLE_DES_TRANSFORMATION = "DESede/ECB/PKCS7Padding";
private static String ALGORITHM = "DESede";
private static String BOUNCY_CASTLE_PROVIDER = "BC";
private static void init()
{
Security.addProvider(new BouncyCastleProvider());
}
public static byte[] encode(byte[] input, byte[] key)
throws IllegalBlockSizeException, BadPaddingException,
NoSuchAlgorithmException, NoSuchProviderException,
NoSuchPaddingException, InvalidKeyException {
init();
SecretKey keySpec = new SecretKeySpec(key, ALGORITHM);
Cipher encrypter = Cipher.getInstance(TRIPLE_DES_TRANSFORMATION,
BOUNCY_CASTLE_PROVIDER);
encrypter.init(Cipher.ENCRYPT_MODE, keySpec);
return encrypter.doFinal(input);
}
public static byte[] decode(byte[] input, byte[] key)
throws IllegalBlockSizeException, BadPaddingException,
NoSuchAlgorithmException, NoSuchProviderException,
NoSuchPaddingException, InvalidKeyException {
init();
SecretKey keySpec = new SecretKeySpec(key, ALGORITHM);
Cipher decrypter = Cipher.getInstance(TRIPLE_DES_TRANSFORMATION,
BOUNCY_CASTLE_PROVIDER);
decrypter.init(Cipher.DECRYPT_MODE, keySpec);
return decrypter.doFinal(input);
}
}
Elasticsearch query to return all records
http://localhost:9200/foo/_search/?size=1000&pretty=1
you will need to specify size query parameter as the default is 10
Check if a string is null or empty in XSLT
If there is a possibility that the element does not exist in the XML I would test both that the element is present and that the string-length is greater than zero:
<xsl:choose>
<xsl:when test="categoryName and string-length(categoryName) > 0">
<xsl:value-of select="categoryName " />
</xsl:when>
<xsl:otherwise>
<xsl:value-of select="other" />
</xsl:otherwise>
</xsl:choose>
ios simulator: how to close an app
For iOS 7 & above:
- shift+command+H twice to simulate the double tap of home button
- swipe your app's screenshot upward to close it
You'll see screenshots representing the apps suspended on your device - those screenshots respond to touch events. Swiping is the gesture you'll make to "fling" the screenshot off of the screen. Note that on machines where your mouse is intended to represent your finger, you'll click and swipe as if it is your finger tapping and making the gesture.
GET URL parameter in PHP
To make sure you're always on the safe side, without getting all kinds of unwanted code insertion use FILTERS:
echo filter_input(INPUT_GET,"link",FILTER_SANITIZE_STRING);
More reading on php.net function filter_input, or check out the description of the different filters
Visual Studio 2017 errors on standard headers
If anyone's still stuck on this, the easiest solution I found was to "Retarget Solution". In my case, the project was built of SDK 8.1, upgrading to VS2017 brought with it SDK 10.0.xxx.
To retarget solution: Project->Retarget Solution->"Select whichever SDK you have installed"->OK
From there on you can simply build/debug your solution. Hope it helps
How can I calculate the number of lines changed between two commits in Git?
Though all above answers are correct, below one is handy to use if you need count of last many commits
below one is to get count of last 5 commits
git diff $(git log -5 --pretty=format:"%h" | tail -1) --shortstat
to get count of last 10 commits
git diff $(git log -10 --pretty=format:"%h" | tail -1) --shortstat
generic - change N with count of last many commits you need
git diff $(git log -N --pretty=format:"%h" | tail -1) --shortstat
to get count of all commits since start
git diff $(git log --pretty=format:"%h" | tail -1) --shortstat