Programs & Examples On #Gwtquery

GwtQuery a.k.a. gQuery is a jQuery-like API written in GWT. It offers the possibility to use the jquery api in gwt projects.

GitHub - failed to connect to github 443 windows/ Failed to connect to gitHub - No Error

(Not an answer, but a very similar problem) I have Git Gui installed on a Windows system behind a proxy. Issuing 'git clone' from a Linux virtual machine running on the Windows system works, but Git Gui yields the 443 error mentioned in the heading.

To fix this, one must edit %USERPROFILE%\.gitconfig to add an [http] section:

[http]
    postBuffer = 1000000000
    proxy = the.proxy.address:the.proxy.port
    sslcainfo = C:/Users/username/Documents/the.certificate.name.cer

Note that the path to the security certificate file has had its backslashes ('\') replaced by slashes ('/').

How do I rotate a picture in WinForms

Here's a method you can use to rotate an image in C#:

/// <summary>
/// method to rotate an image either clockwise or counter-clockwise
/// </summary>
/// <param name="img">the image to be rotated</param>
/// <param name="rotationAngle">the angle (in degrees).
/// NOTE: 
/// Positive values will rotate clockwise
/// negative values will rotate counter-clockwise
/// </param>
/// <returns></returns>
public static Image RotateImage(Image img, float rotationAngle)
{
    //create an empty Bitmap image
    Bitmap bmp = new Bitmap(img.Width, img.Height);

    //turn the Bitmap into a Graphics object
    Graphics gfx = Graphics.FromImage(bmp);

    //now we set the rotation point to the center of our image
    gfx.TranslateTransform((float)bmp.Width / 2, (float)bmp.Height / 2);

    //now rotate the image
    gfx.RotateTransform(rotationAngle);

    gfx.TranslateTransform(-(float)bmp.Width / 2, -(float)bmp.Height / 2);

    //set the InterpolationMode to HighQualityBicubic so to ensure a high
    //quality image once it is transformed to the specified size
    gfx.InterpolationMode = InterpolationMode.HighQualityBicubic;

    //now draw our new image onto the graphics object
    gfx.DrawImage(img, new Point(0, 0));

    //dispose of our Graphics object
    gfx.Dispose();

    //return the image
    return bmp;
}

Boxplot in R showing the mean

I also think chart.Boxplot is the best option, it gives you the position of the mean but if you have a matrix with returns all you need is one line of code to get all the boxplots in one graph.

Here is a small ETF portfolio example.

library(zoo)
library(PerformanceAnalytics)
library(tseries)
library(xts)

VTI.prices = get.hist.quote(instrument = "VTI", start= "2007-03-01", end="2013-03-01",
                        quote = c("AdjClose"),provider = "yahoo",origin ="1970-01-01", 
                        compression = "m", retclass = c("zoo"))

VEU.prices = get.hist.quote(instrument = "VEU", start= "2007-03-01", end="2013-03-01",
                        quote = c("AdjClose"),provider = "yahoo",origin ="1970-01-01", 
                        compression = "m", retclass = c("zoo"))

VWO.prices = get.hist.quote(instrument = "VWO", start= "2007-03-01", end="2013-03-01",
                        quote = c("AdjClose"),provider = "yahoo",origin ="1970-01-01", 
                        compression = "m", retclass = c("zoo"))


VNQ.prices = get.hist.quote(instrument = "VNQ", start= "2007-03-01", end="2013-03-01",
                       quote = c("AdjClose"),provider = "yahoo",origin ="1970-01-01", 
                       compression = "m", retclass = c("zoo"))

TLT.prices = get.hist.quote(instrument = "TLT", start= "2007-03-01", end="2013-03-01",
                        quote = c("AdjClose"),provider = "yahoo",origin ="1970-01-01", 
                        compression = "m", retclass = c("zoo"))

TIP.prices = get.hist.quote(instrument = "TIP", start= "2007-03-01", end="2013-03-01",
                         quote = c("AdjClose"),provider = "yahoo",origin ="1970-01-01", 
                         compression = "m", retclass = c("zoo"))

index(VTI.prices) = as.yearmon(index(VTI.prices))
index(VEU.prices) = as.yearmon(index(VEU.prices))
index(VWO.prices) = as.yearmon(index(VWO.prices))

index(VNQ.prices) = as.yearmon(index(VNQ.prices))
index(TLT.prices) = as.yearmon(index(TLT.prices))
index(TIP.prices) = as.yearmon(index(TIP.prices))

Prices.z=merge(VTI.prices, VEU.prices, VWO.prices, VNQ.prices, 
           TLT.prices, TIP.prices)

colnames(Prices.z) = c("VTI", "VEU", "VWO" , "VNQ", "TLT", "TIP")

returnscc.z = diff(log(Prices.z))

start(returnscc.z)
end(returnscc.z)
colnames(returnscc.z) 
head(returnscc.z)

Return Matrix

ret.mat = coredata(returnscc.z)
class(ret.mat)
colnames(ret.mat)
head(ret.mat)

Box Plot of Return Matrix

chart.Boxplot(returnscc.z, names=T, horizontal=TRUE, colorset="darkgreen", as.Tufte =F,
          mean.symbol = 20, median.symbol="|", main="Return Distributions Comparison",
          element.color = "darkgray", outlier.symbol = 20, 
          xlab="Continuously Compounded Returns", sort.ascending=F)

You can try changing the mean.symbol, and remove or change the median.symbol. Hope it helped. :)

Using JQuery to open a popup window and print

Got it! I found an idea here

http://www.mail-archive.com/[email protected]/msg18410.html

In this example, they loaded a blank popup window into an object, cloned the contents of the element to be displayed, and appended it to the body of the object. Since I already knew what the contents of view-details (or any page I load in the lightbox), I just had to clone that content instead and load it into an object. Then, I just needed to print that object. The final outcome looks like this:

$('.printBtn').bind('click',function() {
    var thePopup = window.open( '', "Customer Listing", "menubar=0,location=0,height=700,width=700" );
    $('#popup-content').clone().appendTo( thePopup.document.body );
    thePopup.print();
});

I had one small drawback in that the style sheet I was using in view-details.php was using a relative link. I had to change it to an absolute link. The reason being that the window didn't have a URL associated with it, so it had no relative position to draw on.

Works in Firefox. I need to test it in some other major browsers too.

I don't know how well this solution works when you're dealing with images, videos, or other process intensive solutions. Although, it works pretty well in my case, since I'm just loading tables and text values.

Thanks for the input! You gave me some ideas of how to get around this.

How to list all files in a directory and its subdirectories in hadoop hdfs

You'll need to use the FileSystem object and perform some logic on the resultant FileStatus objects to manually recurse into the subdirectories.

You can also apply a PathFilter to only return the xml files using the listStatus(Path, PathFilter) method

The hadoop FsShell class has examples of this for the hadoop fs -lsr command, which is a recursive ls - see the source, around line 590 (the recursive step is triggered on line 635)

bootstrap 3 - how do I place the brand in the center of the navbar?

To fix the overlap, you only need modify the .navbar-toggle in your own css styles

something like this, it works for me:

.navbar-toggle{
z-index: 10;
}

How to create nested directories using Mkdir in Golang?

An utility method like the following can be used to solve this.

import (
  "os"
  "path/filepath"
  "log"
)

func ensureDir(fileName string) {
  dirName := filepath.Dir(fileName)
  if _, serr := os.Stat(dirName); serr != nil {
    merr := os.MkdirAll(dirName, os.ModePerm)
    if merr != nil {
        panic(merr)
    }
  }
}



func main() {
  _, cerr := os.Create("a/b/c/d.txt")
  if cerr != nil {
    log.Fatal("error creating a/b/c", cerr)
  }
  log.Println("created file in a sub-directory.")
}

How to export a Vagrant virtual machine to transfer it

The easiest way would be to package the Vagrant box and then copy (e.g. scp or rsync) it over to the other PC, add it and vagrant up ;-)

For detailed steps, check this out => Is there any way to clone a vagrant box that is already installed

Cross compile Go on OSX?

The process of creating executables for many platforms can be a little tedious, so I suggest to use a script:

#!/usr/bin/env bash

package=$1
if [[ -z "$package" ]]; then
  echo "usage: $0 <package-name>"
  exit 1
fi
package_name=$package

#the full list of the platforms: https://golang.org/doc/install/source#environment
platforms=(
"darwin/386"
"dragonfly/amd64"
"freebsd/386"
"freebsd/amd64"
"freebsd/arm"
"linux/386"
"linux/amd64"
"linux/arm"
"linux/arm64"
"netbsd/386"
"netbsd/amd64"
"netbsd/arm"
"openbsd/386"
"openbsd/amd64"
"openbsd/arm"
"plan9/386"
"plan9/amd64"
"solaris/amd64"
"windows/amd64"
"windows/386" )

for platform in "${platforms[@]}"
do
    platform_split=(${platform//\// })
    GOOS=${platform_split[0]}
    GOARCH=${platform_split[1]}
    output_name=$package_name'-'$GOOS'-'$GOARCH
    if [ $GOOS = "windows" ]; then
        output_name+='.exe'
    fi

    env GOOS=$GOOS GOARCH=$GOARCH go build -o $output_name $package
    if [ $? -ne 0 ]; then
        echo 'An error has occurred! Aborting the script execution...'
        exit 1
    fi
done

I checked this script on OSX only

gist - go-executable-build.sh

How do I select an element with its name attribute in jQuery?

You can use:

jQuery('[name="' + nameAttributeValue + '"]');

this will be an inefficient way to select elements though, so it would be best to also use the tag name or restrict the search to a specific element:

jQuery('div[name="' + nameAttributeValue + '"]'); // with tag name
jQuery('div[name="' + nameAttributeValue + '"]',
     document.getElementById('searcharea'));      // with a search base

Remove spaces from a string in VB.NET

What about Regex.Replace solution?

myStr = Regex.Replace(myStr, "\s", "")

How to switch back to 'master' with git?

According to the Git Cheatsheet you have to create the branch first

git branch [branchName]

and then

git checkout [branchName]

Get element inside element by class and ID - JavaScript

Well, first you need to select the elements with a function like getElementById.

var targetDiv = document.getElementById("foo").getElementsByClassName("bar")[0];

getElementById only returns one node, but getElementsByClassName returns a node list. Since there is only one element with that class name (as far as I can tell), you can just get the first one (that's what the [0] is for—it's just like an array).

Then, you can change the html with .textContent.

targetDiv.textContent = "Goodbye world!";

_x000D_
_x000D_
var targetDiv = document.getElementById("foo").getElementsByClassName("bar")[0];_x000D_
targetDiv.textContent = "Goodbye world!";
_x000D_
<div id="foo">_x000D_
    <div class="bar">_x000D_
        Hello world!_x000D_
    </div>_x000D_
</div>
_x000D_
_x000D_
_x000D_

Setting default checkbox value in Objective-C?

Documentation on UISwitch says:

[mySwitch setOn:NO]; 

In Interface Builder, select your switch and in the Attributes inspector you'll find State which can be set to on or off.

MySQL table is marked as crashed and last (automatic?) repair failed

This was my experience resolving this issue. I'm using XAMPP. I was getting the error below

 Fatal error: Can't open and lock privilege tables: Table '.\mysql\db' is marked as crashed and last (automatic?) repair failed  

This is what I did to resolve it, step by step:

  1. went to location C:\xampp\mysql, For you, location may be different, make sure you are in right file location.
  2. created backup of the data folder as data-old.
  3. copied folder "mysql" from C:\xampp\mysql\backup
  4. pasted it inside C:\xampp\mysql\data\ replacing the old mysql folder.

And it worked. Keep in mind, I have already tried around 10 solutions and they didnt work for me. This solutions may or may not work for you but regardless, make backup of your data folder before you do anything.

Note: I would always opt to resolve this with repair command but in my case, i wasnt able to get mysql started at all and i wasnt able to get myisamchk command to work.

Regardless of what you do, create a periodic backup of your database.

How can I concatenate a string within a loop in JSTL/JSP?

define a String variable using the JSP tags

<%!
String test = new String();
%>

then refer to that variable in your loop as

<c:forEach items="${myParams.items}" var="currentItem" varStatus="stat">
test+= whaterver_value
</c:forEach>

Node.js: printing to console without a trailing newline?

I got the following error when using strict mode:

Node error: "Octal literals are not allowed in strict mode."

The following solution works (source):

process.stdout.write("received: " + bytesReceived + "\x1B[0G");

A top-like utility for monitoring CUDA activity on a GPU

Just use watch nvidia-smi, it will output the message by 2s interval in default.

For example, as the below image:

enter image description here

You can also use watch -n 5 nvidia-smi (-n 5 by 5s interval).

Converting std::__cxx11::string to std::string

I got this, the only way I found to fix this was to update all of mingw-64 (I did this using pacman on msys2 for your information).

Detecting input change in jQuery?

With HTML5 and without using jQuery, you can using the input event:

var input = document.querySelector('input');

input.addEventListener('input', function()
{
    console.log('input changed to: ', input.value);
});

This will fire each time the input's text changes.

Supported in IE9+ and other browsers.

Try it live in a jsFiddle here.

How to call a button click event from another method

You can perform different approaches to work around this. The best approach is, if your both buttons are suppose to do the same job, you can define a third function to do the job. for example :

private void SubGraphButton_Click(object sender, RoutedEventArgs args)
{
    myJob()  
}

private void ChildNode_Click(object sender, RoutedEventArgs args)
{
    myJob()
}

private void myJob()
{
    // Your code here
}

but if you are still persisting on doing it in your way, the best action is :

private void SubGraphButton_Click(object sender, RoutedEventArgs args)
{
}

private void ChildNode_Click(object sender, RoutedEventArgs args)
{
   SubGraphButton_Click.PerformClick();
}

Where to install Android SDK on Mac OS X?

brew install android-sdk --cask 

Django - "no module named django.core.management"

Are you using a Virtual Environment with Virtual Wrapper? Are you on a Mac?

If so try this:

Enter the following into your command line to start up the virtual environment and then work on it

1.)

source virtualenvwrapper.sh

or

source /usr/local/bin/virtualenvwrapper.sh

2.)

workon [environment name]

Note (from a newbie) - do not put brackets around your environment name

ORA-30926: unable to get a stable set of rows in the source tables

Had the error today on a 12c and none of the existing answers fit (no duplicates, no non-deterministic expressions in the WHERE clause). My case was related to that other possible cause of the error, according to Oracle's message text (emphasis below):

ORA-30926: unable to get a stable set of rows in the source tables
Cause: A stable set of rows could not be got because of large dml activity or a non-deterministic where clause.

The merge was part of a larger batch, and was executed on a live database with many concurrent users. There was no need to change the statement. I just committed the transaction before the merge, then ran the merge separately, and committed again. So the solution was found in the suggested action of the message:

Action: Remove any non-deterministic where clauses and reissue the dml.

Storyboard - refer to ViewController in AppDelegate

Generally, the system should be handling view controller instantiation with a storyboard. What you want is to traverse the viewController hierarchy by grabbing a reference to the self.window.rootViewController as opposed to initializing view controllers, which should already be initialized correctly if you've setup your storyboard properly.

So, let's say your rootViewController is a UINavigationController and then you want to send something to its top view controller, you would do it like this in your AppDelegate's didFinishLaunchingWithOptions:

UINavigationController *nav = (UINavigationController *) self.window.rootViewController;
MyViewController *myVC = (MyViewController *)nav.topViewController;
myVC.data = self.data;

In Swift if would be very similar:

let nav = self.window.rootViewController as! UINavigationController;
let myVC = nav.topViewController as! MyViewController
myVc.data = self.data

You really shouldn't be initializing view controllers using storyboard id's from the app delegate unless you want to bypass the normal way storyboard is loaded and load the whole storyboard yourself. If you're having to initialize scenes from the AppDelegate you're most likely doing something wrong. I mean imagine you, for some reason, want to send data to a view controller way down the stack, the AppDelegate shouldn't be reaching way into the view controller stack to set data. That's not its business. It's business is the rootViewController. Let the rootViewController handle its own children! So, if I were bypassing the normal storyboard loading process by the system by removing references to it in the info.plist file, I would at most instantiate the rootViewController using instantiateViewControllerWithIdentifier:, and possibly its root if it is a container, like a UINavigationController. What you want to avoid is instantiating view controllers that have already been instantiated by the storyboard. This is a problem I see a lot. In short, I disagree with the accepted answer. It is incorrect unless the posters means to remove loading of the storyboard from the info.plist since you will have loaded 2 storyboards otherwise, which makes no sense. It's probably not a memory leak because the system initialized the root scene and assigned it to the window, but then you came along and instantiated it again and assigned it again. Your app is off to a pretty bad start!

How can I convert an Integer to localized month name in Java?

Here's how I would do it. I'll leave range checking on the int month up to you.

import java.text.DateFormatSymbols;

public String formatMonth(int month, Locale locale) {
    DateFormatSymbols symbols = new DateFormatSymbols(locale);
    String[] monthNames = symbols.getMonths();
    return monthNames[month - 1];
}

Convert a character digit to the corresponding integer in C

If, by some crazy coincidence, you want to convert a string of characters to an integer, you can do that too!

char *num = "1024";
int val = atoi(num); // atoi = ASCII TO Int

val is now 1024. Apparently atoi() is fine, and what I said about it earlier only applies to me (on OS X (maybe (insert Lisp joke here))). I have heard it is a macro that maps roughly to the next example, which uses strtol(), a more general-purpose function, to do the conversion instead:

char *num = "1024";
int val = (int)strtol(num, (char **)NULL, 10); // strtol = STRing TO Long

strtol() works like this:

long strtol(const char *str, char **endptr, int base);

It converts *str to a long, treating it as if it were a base base number. If **endptr isn't null, it holds the first non-digit character strtol() found (but who cares about that).

What does "Use of unassigned local variable" mean?

Because if none of the if statements evaluate to true then the local variable will be unassigned. Throw an else statement in there and assign some values to those variables in case the if statements don't evaluate to true. Post back here if that doesn't make the error go away.

Your other option is to initialize the variables to some default value when you declare them at the beginning of your code.

How can I match multiple occurrences with a regex in JavaScript similar to PHP's preg_match_all()?

If someone (like me) needs Tomalak's method with array support (ie. multiple select), here it is:

function getUrlParams(url) {
  var re = /(?:\?|&(?:amp;)?)([^=&#]+)(?:=?([^&#]*))/g,
      match, params = {},
      decode = function (s) {return decodeURIComponent(s.replace(/\+/g, " "));};

  if (typeof url == "undefined") url = document.location.href;

  while (match = re.exec(url)) {
    if( params[decode(match[1])] ) {
        if( typeof params[decode(match[1])] != 'object' ) {
            params[decode(match[1])] = new Array( params[decode(match[1])], decode(match[2]) );
        } else {
            params[decode(match[1])].push(decode(match[2]));
        }
    }
    else
        params[decode(match[1])] = decode(match[2]);
  }
  return params;
}
var urlParams = getUrlParams(location.search);

input ?my=1&my=2&my=things

result 1,2,things (earlier returned only: things)

How to style a checkbox using CSS

It seems you can change the colour of the checkbox in grayscale by using CSS only.

The following converts the checkboxes from black to gray (which was about what I wanted):

input[type="checkbox"] {
    opacity: .5;
}

post ajax data to PHP and return data

 $.ajax({
            type: "POST",
            data: {data:the_id},
            url: "http://localhost/test/index.php/data/count_votes",
            success: function(data){
               //data will contain the vote count echoed by the controller i.e.  
                 "yourVoteCount"
              //then append the result where ever you want like
              $("span#votes_number").html(data); //data will be containing the vote count which you have echoed from the controller

                }
            });

in the controller

$data = $_POST['data'];  //$data will contain the_id
//do some processing
echo "yourVoteCount";

Clarification

i think you are confusing

{data:the_id}

with

success:function(data){

both the data are different for your own clarity sake you can modify it as

success:function(vote_count){
$(span#someId).html(vote_count);

Maven: Command to update repository after adding dependency to POM

Pay attention to your dependency scope I was having the issue where when I invoke clean compile via Intellij, the pom would get downloaded, but the jar would not. There was a xxx.jar.lastUpdated file created. Then realized that the dependency scope was test, but I was triggering the compile. I deleted the repos, and triggered the mvn test, and issue was resolved.

How to actually search all files in Visual Studio

One can access the "Find in Files" window via the drop-down menu selection and search all files in the Entire Solution: Edit > Find and Replace > Find in Files

enter image description here

Other, alternative is to open the "Find in Files" window via the "Standard Toolbars" button as highlighted in the below screen-short:

enter image description here

URL encode sees “&” (ampersand) as “&amp;” HTML entity

If you did literally this:

encodeURIComponent('&')

Then the result is %26, you can test it here. Make sure the string you are encoding is just & and not &amp; to begin with...otherwise it is encoding correctly, which is likely the case. If you need a different result for some reason, you can do a .replace(/&amp;/g,'&') before the encoding.

Return HTML content as a string, given URL. Javascript Function

after you get the response just do call this function to append data to your body element

function createDiv(responsetext)
{
    var _body = document.getElementsByTagName('body')[0];
    var _div = document.createElement('div');
    _div.innerHTML = responsetext;
    _body.appendChild(_div);
}

@satya code modified as below

function httpGet(theUrl)
{
    if (window.XMLHttpRequest)
    {// code for IE7+, Firefox, Chrome, Opera, Safari
        xmlhttp=new XMLHttpRequest();
    }
    else
    {// code for IE6, IE5
        xmlhttp=new ActiveXObject("Microsoft.XMLHTTP");
    }
    xmlhttp.onreadystatechange=function()
    {
        if (xmlhttp.readyState==4 && xmlhttp.status==200)
        {
            createDiv(xmlhttp.responseText);
        }
    }
    xmlhttp.open("GET", theUrl, false);
    xmlhttp.send();    
}

The declared package does not match the expected package ""

Make sure that You have created a correct package.You might get a chance to create folder instead of package

Comparing arrays for equality in C++

if (iar1 == iar2)

Here iar1 and iar2 are decaying to pointers to the first elements of the respective arrays. Since they are two distinct arrays, the pointer values are, of course, different and your comparison tests not equal.

To do an element-wise comparison, you must either write a loop; or use std::array instead

std::array<int, 5> iar1 {1,2,3,4,5};
std::array<int, 5> iar2 {1,2,3,4,5};

if( iar1 == iar2 ) {
  // arrays contents are the same

} else {
  // not the same

}

How to prevent vim from creating (and leaving) temporary files?

I have this setup in my Ubuntu .vimrc. I don't see any swap files in my project files.

set undofile
set undolevels=1000         " How many undos
set undoreload=10000        " number of lines to save for undo

set backup                        " enable backups
set swapfile                      " enable swaps
set undodir=$HOME/.vim/tmp/undo     " undo files
set backupdir=$HOME/.vim/tmp/backup " backups
set directory=$HOME/.vim/tmp/swap   " swap files

" Make those folders automatically if they don't already exist.
if !isdirectory(expand(&undodir))
    call mkdir(expand(&undodir), "p")
endif
if !isdirectory(expand(&backupdir))
    call mkdir(expand(&backupdir), "p")
endif
if !isdirectory(expand(&directory))
    call mkdir(expand(&directory), "p")
endif

Save multiple sheets to .pdf

In Excel 2013 simply select multiple sheets and do a "Save As" and select PDF as the file type. The multiple pages will open in PDF when you click save.

How can you find the height of text on an HTML canvas?

setting the font size might not be practical though, since setting

ctx.font = ''

will use the one defined by CSS as well as any embedded font tags. If you use the CSS font you have no idea what the height is from a programmatic way, using the measureText method, which is very short sighted. On another note though, IE8 DOES return the width and height.

How can I get customer details from an order in WooCommerce?

$customer_id = get_current_user_id();
print get_user_meta( $customer_id, 'billing_first_name', true );

Good Hash Function for Strings

Its a good idea to work with odd number when trying to develop a good hast function for string. this function takes a string and return a index value, so far its work pretty good. and has less collision. the index ranges from 0 - 300 maybe even more than that, but i haven't gotten any higher so far even with long words like "electromechanical engineering"

int keyHash(string key)
{
    unsigned int k = (int)key.length();
    unsigned int u = 0,n = 0;

    for (Uint i=0; i<k; i++)
    {
        n = (int)key[i];
        u += 7*n%31;
    }
    return u%139;
}

another thing you can do is multiplying each character int parse by the index as it increase like the word "bear" (0*b) + (1*e) + (2*a) + (3*r) which will give you an int value to play with. the first hash function above collide at "here" and "hear" but still great at give some good unique values. the one below doesn't collide with "here" and "hear" because i multiply each character with the index as it increases.

int keyHash(string key)
{
    unsigned int k = (int)key.length();
    unsigned int u = 0,n = 0;

    for (Uint i=0; i<k; i++)
    {
        n = (int)key[i];
        u += i*n%31;
    }
    return u%139;
}

Execute Python script via crontab

Just use crontab -e and follow the tutorial here.

Look at point 3 for a guide on how to specify the frequency.

Based on your requirement, it should effectively be:

*/10 * * * * /usr/bin/python script.py

Convert a number to 2 decimal places in Java

Try

DecimalFormat df = new DecimalFormat("#,##0.00");

how to use substr() function in jquery?

If you want to extract from a tag then

$('.dep_buttons').text().substr(0,25)

With the mouseover event,

$(this).text($(this).text().substr(0, 25));

The above will extract the text of a tag, then extract again assign it back.

JavaScript and getElementById for multiple elements with the same ID

As others have stated, you shouldn't have the same ID more than once in your HTML, however... elements with an ID are attached to the document object and to window on Internet Explorer. Refer to:

Do DOM tree elements with ids become global variables?

If more than one element with the same ID exists in your HTML, this property is attached as an array. I'm sorry, but I don't know where to look if this is the standard behavior or at least you get the same behavior between browsers, which I doubt.

Adding link a href to an element using css

You cannot simply add a link using CSS. CSS is used for styling.

You can style your using CSS.

If you want to give a link dynamically to then I will advice you to use jQuery or Javascript.

You can accomplish that very easily using jQuery.

I have done a sample for you. You can refer that.

URL : http://jsfiddle.net/zyk9w/

$('#link').attr('href','http://www.google.com');

This single line will do the trick.

Code for Greatest Common Divisor in Python

def _grateest_common_devisor_euclid(p, q):
    if q==0 :
        return p
    else:
        reminder = p%q
        return _grateest_common_devisor_euclid(q, reminder)

print(_grateest_common_devisor_euclid(8,3))

How to move or copy files listed by 'find' command in unix?

This is the best way for me:

cat filename.tsv  |
    while read FILENAME
    do
    sudo find /PATH_FROM/  -name "$FILENAME" -maxdepth 4 -exec cp '{}' /PATH_TO/ \; ;
    done

Force browser to download image files on click

In 2020 I use Blob to make local copy of image, which browser will download as a file. You can test it on this site.

enter image description here

(function(global) {
  const next = () => document.querySelector('.search-pagination__button-text').click();
  const uuid = () => Math.random().toString(36).substring(7);
  const toBlob = (src) => new Promise((res) => {
    const img = document.createElement('img');
    const c = document.createElement("canvas");
    const ctx = c.getContext("2d");
    img.onload = ({target}) => {
      c.width = target.naturalWidth;
      c.height = target.naturalHeight;
      ctx.drawImage(target, 0, 0);
      c.toBlob((b) => res(b), "image/jpeg", 0.75);
    };
    img.crossOrigin = "";
    img.src = src;
  });
  const save = (blob, name = 'image.png') => {
    const a = document.createElement("a");
    a.href = URL.createObjectURL(blob);
    a.target = '_blank';
    a.download = name;
    a.click();
  };
  global.download = () => document.querySelectorAll('.search-content__gallery-results figure > img[src]').forEach(async ({src}) => save(await toBlob(src), `${uuid()}.png`));
  global.next = () => next();
})(window);

the easiest way to convert matrix to one row vector

You can use the function RESHAPE:

B = reshape(A.',1,[]);

How can I display a pdf document into a Webview?

Opening a pdf using google docs is a bad idea in terms of user experience. It is really slow and unresponsive.

Solution after API 21

Since api 21, we have PdfRenderer which helps converting a pdf to Bitmap. I've never used it but is seems easy enough.

Solution for any api level

Other solution is to download the PDF and pass it via Intent to a dedicated PDF app which will do a banger job displaying it. Fast and nice user experience, especially if this feature is not central in your app.

Use this code to download and open the PDF

public class PdfOpenHelper {

public static void openPdfFromUrl(final String pdfUrl, final Activity activity){
    Observable.fromCallable(new Callable<File>() {
        @Override
        public File call() throws Exception {
            try{
                URL url = new URL(pdfUrl);
                URLConnection connection = url.openConnection();
                connection.connect();

                // download the file
                InputStream input = new BufferedInputStream(connection.getInputStream());
                File dir = new File(activity.getFilesDir(), "/shared_pdf");
                dir.mkdir();
                File file = new File(dir, "temp.pdf");
                OutputStream output = new FileOutputStream(file);

                byte data[] = new byte[1024];
                long total = 0;
                int count;
                while ((count = input.read(data)) != -1) {
                    total += count;
                    output.write(data, 0, count);
                }

                output.flush();
                output.close();
                input.close();
                return file;
            } catch (IOException e) {
                e.printStackTrace();
            }
            return null;
        }
    })
            .subscribeOn(Schedulers.io())
            .observeOn(AndroidSchedulers.mainThread())
            .subscribe(new Subscriber<File>() {
                @Override
                public void onCompleted() {

                }

                @Override
                public void onError(Throwable e) {

                }

                @Override
                public void onNext(File file) {
                    String authority = activity.getApplicationContext().getPackageName() + ".fileprovider";
                    Uri uriToFile = FileProvider.getUriForFile(activity, authority, file);

                    Intent shareIntent = new Intent(Intent.ACTION_VIEW);
                    shareIntent.setDataAndType(uriToFile, "application/pdf");
                    shareIntent.addFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION);
                    if (shareIntent.resolveActivity(activity.getPackageManager()) != null) {
                        activity.startActivity(shareIntent);
                    }
                }
            });
}

}

For the Intent to work, you need to create a FileProvider to grant permission to the receiving app to open the file.

Here is how you implement it: In your Manifest:

    <provider
        android:name="android.support.v4.content.FileProvider"
        android:authorities="${applicationId}.fileprovider"
        android:exported="false"
        android:grantUriPermissions="true">

        <meta-data
            android:name="android.support.FILE_PROVIDER_PATHS"
            android:resource="@xml/file_paths" />

    </provider>

Finally create a file_paths.xml file in the resources foler

<?xml version="1.0" encoding="utf-8"?>
<paths>
    <files-path name="shared_pdf" path="shared_pdf"/>
</paths>

Hope this helps =)

How to get the ASCII value in JavaScript for the characters

Here is the example:

_x000D_
_x000D_
var charCode = "a".charCodeAt(0);_x000D_
console.log(charCode);
_x000D_
_x000D_
_x000D_

Or if you have longer strings:

_x000D_
_x000D_
var string = "Some string";_x000D_
_x000D_
for (var i = 0; i < string.length; i++) {_x000D_
  console.log(string.charCodeAt(i));_x000D_
}
_x000D_
_x000D_
_x000D_

String.charCodeAt(x) method will return ASCII character code at a given position.

iPhone is not available. Please reconnect the device

Xcode 11.4 does not support the new iOS 13.5. Updating to Xcode 11.5 fixed the issue for me

https://developer.apple.com/documentation/xcode_release_notes/xcode_11_4_release_notes

Known Issues Xcode 11.4 doesn’t work with devices running iOS 13.4 beta 1 and beta 2. (60055806)

How do change the color of the text of an <option> within a <select>?

_x000D_
_x000D_
<select id="select">_x000D_
    <optgroup label="select one option">_x000D_
        <option>one</option>  _x000D_
        <option>two</option>  _x000D_
        <option>three</option>  _x000D_
        <option>four</option>  _x000D_
        <option>five</option>_x000D_
    </optgroup>_x000D_
</select>
_x000D_
_x000D_
_x000D_

It all sounded like a lot of hard work to me, when optgroup gives you what you need - at least I think it does.

Numpy AttributeError: 'float' object has no attribute 'exp'

Probably there's something wrong with the input values for X and/or T. The function from the question works ok:

import numpy as np
from math import e

def sigmoid(X, T):
  return 1.0 / (1.0 + np.exp(-1.0 * np.dot(X, T)))

X = np.array([[1, 2, 3], [5, 0, 0]])
T = np.array([[1, 2], [1, 1], [4, 4]])

print(X.dot(T))
# Just to see if values are ok
print([1. / (1. + e ** el) for el in [-5, -10, -15, -16]])
print()
print(sigmoid(X, T))

Result:

[[15 16]
 [ 5 10]]

[0.9933071490757153, 0.9999546021312976, 0.999999694097773, 0.9999998874648379]

[[ 0.99999969  0.99999989]
 [ 0.99330715  0.9999546 ]]

Probably it's the dtype of your input arrays. Changing X to:

X = np.array([[1, 2, 3], [5, 0, 0]], dtype=object)

Gives:

Traceback (most recent call last):
  File "/[...]/stackoverflow_sigmoid.py", line 24, in <module>
    print sigmoid(X, T)
  File "/[...]/stackoverflow_sigmoid.py", line 14, in sigmoid
    return 1.0 / (1.0 + np.exp(-1.0 * np.dot(X, T)))
AttributeError: exp

@RequestParam vs @PathVariable

If the URL http://localhost:8080/MyApp/user/1234/invoices?date=12-05-2013 gets the invoices for user 1234 on December 5th, 2013, the controller method would look like:

@RequestMapping(value="/user/{userId}/invoices", method = RequestMethod.GET)
public List<Invoice> listUsersInvoices(
            @PathVariable("userId") int user,
            @RequestParam(value = "date", required = false) Date dateOrNull) {
  ...
}

Also, request parameters can be optional, and as of Spring 4.3.3 path variables can be optional as well. Beware though, this might change the URL path hierarchy and introduce request mapping conflicts. For example, would /user/invoices provide the invoices for user null or details about a user with ID "invoices"?

How do I find which process is leaking memory?

if the program leaks over a long time, top might not be practical. I would write a simple shell scripts that appends the result of "ps aux" to a file every X seconds, depending on how long it takes to leak significant amounts of memory. Something like:

while true
do
echo "---------------------------------" >> /tmp/mem_usage
date >> /tmp/mem_usage
ps aux >> /tmp/mem_usage
sleep 60
done

How to upgrade R in ubuntu?

Since R is already installed, you should be able to upgrade it with this method. First of all, you may want to have the packages you installed in the previous version in the new one,so it is convenient to check this post. Then, follow the instructions from here

  1. Open the sources.list file:

     sudo nano /etc/apt/sources.list    
    
  2. Add a line with the source from where the packages will be retrieved. For example:

     deb https://cloud.r-project.org/bin/linux/ubuntu/ version/
    

    Replace https://cloud.r-project.org with whatever mirror you would like to use, and replace version/ with whatever version of Ubuntu you are using (eg, trusty/, xenial/, and so on). If you're getting a "Malformed line error", check to see if you have a space between /ubuntu/ and version/.

  3. Fetch the secure APT key:

     gpg --keyserver keyserver.ubuntu.com --recv-key E298A3A825C0D65DFD57CBB651716619E084DAB9
    

or

    gpg --hkp://keyserver keyserver.ubuntu.com:80 --recv-key E298A3A825C0D65DFD57CBB651716619E084DAB9
  1. Add it to keyring:

     gpg -a --export E084DAB9 | sudo apt-key add -
    
  2. Update your sources and upgrade your installation:

     sudo apt-get update && sudo apt-get upgrade
    
  3. Install the new version

     sudo apt-get install r-base-dev
    
  4. Recover your old packages following the solution that best suits to you (see this). For instance, to recover all the packages (not only those from CRAN) the idea is:

-- copy the packages from R-oldversion/library to R-newversion/library, (do not overwrite a package if it already exists in the new version!).

-- Run the R command update.packages(checkBuilt=TRUE, ask=FALSE).

How to use BigInteger?

BigInteger is an immutable class. So whenever you do any arithmetic, you have to reassign the output to a variable.

Does the target directory for a git clone have to match the repo name?

Yes, it is possible:

git clone https://github.com/pitosalas/st3_packages Packages 

You can specify the local root directory when using git clone.

<directory> 

The name of a new directory to clone into.
The "humanish" part of the source repository is used if no directory is explicitly given (repo for /path/to/repo.git and foo for host.xz:foo/.git).
Cloning into an existing directory is only allowed if the directory is empty.


As Chris comments, you can then rename that top directory.
Git only cares about the .git within said top folder, which you can get with various commands:

git rev-parse --show-toplevel git rev-parse --git-dir 

Multi-character constant warnings

This warning is useful for programmers that would mistakenly write 'test' where they should have written "test".

This happen much more often than programmers that do actually want multi-char int constants.

Inserting the same value multiple times when formatting a string

You can use advanced string formatting, available in Python 2.6 and Python 3.x:

incoming = 'arbit'
result = '{0} hello world {0} hello world {0}'.format(incoming)

What's the correct way to convert bytes to a hex string in Python 3?

Use the binascii module:

>>> import binascii
>>> binascii.hexlify('foo'.encode('utf8'))
b'666f6f'
>>> binascii.unhexlify(_).decode('utf8')
'foo'

See this answer: Python 3.1.1 string to hex

How to replace all occurrences of a string in Javascript?

You can simply use below method

/**
 * Replace all the occerencess of $find by $replace in $originalString
 * @param  {originalString} input - Raw string.
 * @param  {find} input - Target key word or regex that need to be replaced.
 * @param  {replace} input - Replacement key word
 * @return {String}       Output string
 */
function replaceAll(originalString, find, replace) {
  return originalString.replace(new RegExp(find, 'g'), replace);
};

How to change date format using jQuery?

You can use date.js to achieve this:

var date = new Date('2014-01-06');
var newDate = date.toString('dd-MM-yy');

Alternatively, you can do it natively like this:

_x000D_
_x000D_
var dateAr = '2014-01-06'.split('-');_x000D_
var newDate = dateAr[1] + '-' + dateAr[2] + '-' + dateAr[0].slice(-2);_x000D_
_x000D_
console.log(newDate);
_x000D_
_x000D_
_x000D_

ThreeJS: Remove object from scene

THIS WORKS GREAT - I tested it so, please SET NAME for every object

give the name to the object upon creation

    mesh.name = 'nameMeshObject';

and use this if you have to delete an object

    delete3DOBJ('nameMeshObject');



    function delete3DOBJ(objName){
        var selectedObject = scene.getObjectByName(objName);
        scene.remove( selectedObject );
        animate();
    }

open a new scene , add object open new scene , add object

delete an object and create new delete object and create new

How to find all tables that have foreign keys that reference particular table.column and have values for those foreign keys?

Easiest:
1. Open phpMyAdmin
2. On the left click database name
3. On the top right corner find "Designer" tab

All constraints will be shown there.

Difference between two dates in years, months, days in JavaScript

I've stumbled upon this while having the same problem. Here is my code. It totally relies on the JS date function, so leap years are handled, and does not compare days based on hours, so it avoids daylight saving issues.

function dateDiff(start, end) {
    let years = 0, months = 0, days = 0;
    // Day diffence. Trick is to use setDate(0) to get the amount of days
    // from the previous month if the end day less than the start day.
    if (end.getDate() < start.getDate()) {
        months = -1;
        let datePtr = new Date(end);
        datePtr.setDate(0);
        days = end.getDate() + (datePtr.getDate() - start.getDate());
    } else {
        days = end.getDate() - start.getDate();
    }

    if (end.getMonth() < start.getMonth() ||
       (end.getMonth() === start.getMonth() && end.getDate() < start.getDate())) {
        years = -1;
        months += end.getMonth() + (12 - start.getMonth());
    } else {
        months += end.getMonth() - start.getMonth();
    }

    years += end.getFullYear() - start.getFullYear();
    console.log(`${years}y ${months}m ${days}d`);
    return [years, months, days];
}

Reading Properties file in Java

I see that the question is an old one. If anyone stumbles upon this in the future, I think this is one simple way of doing it. Keep the properties file in your project folder.

        FileReader reader = new FileReader("Config.properties");

        Properties prop = new Properties();
        prop.load(reader);

Cannot run the macro... the macro may not be available in this workbook

In my case the error happened when I placed my macro (public sub) into a ThisWorkbook section of the file expecting it will make it visible for Application.Run function. This was not the case and I got that error you mentioned.

I moved my macro into a separate Module and it resolved the problem.

How do I include a file over 2 directories back?

. = current directory
.. = parent directory

So ../ gets you one directory back not two.

Chain ../ as many times as necessary to go up 2 or more levels.

How to Navigate from one View Controller to another using Swift

Swift 5

Use Segue to perform navigation from one View Controller to another View Controller:

performSegue(withIdentifier: "idView", sender: self)

This works on Xcode 10.2.

jQuery hasClass() - check for more than one class

use default js match() function:

if( element.attr('class') !== undefined && element.attr('class').match(/class1|class2|class3|class4|class5/) ) {
  console.log("match");
}

to use variables in regexp, use this:

var reg = new RegExp(variable, 'g');
$(this).match(reg);

by the way, this is the fastest way: http://jsperf.com/hasclass-vs-is-stackoverflow/22

Running ASP.Net on a Linux based server

You can use Mono to run ASP.NET applications on Apache/Linux, however it has a limited subset of what you can do under Windows. As for "they" saying Windows is more vulnerable to attack - it's not true. IIS has had less security problems over the last couple of years that Apache, but in either case it's all down to the administration of the boxes - both OSes can be easily secured. These days the attack points are not the OS or web server software, but the applications themselves.

curl_exec() always returns false

This happened to me yesterday and in my case was because I was following a PDF manual to develop some module to communicate with an API and while copying the link directly from the manual, for some odd reason, the hyphen from the copied link was in a different encoding and hence the curl_exec() was always returning false because it was unable to communicate with the server.

It took me a couple hours to finally understand the diference in the characters bellow:

https://www.e-example.com/api
https://www.e-example.com/api

Every time I tried to access the link directly from a browser it converted to something likehttps://www.xn--eexample-0m3d.com/api.

It may seem to you that they are equal but if you check the encoding of the hyphens here you'll see that the first hyphen is a unicode characters U+2010 and the other is a U+002D.

Hope this helps someone.

Is there a way to get LaTeX to place figures in the same page as a reference to that figure?

You can always add the "!" into your float-options. This way, latex tries really hard to place the figure where you want it (I mostly use [h!tb]), stretching the normal rules of type-setting.

I have found another solution:
Use the float-package. This way you can place the figures where you want them to be.

Shrinking navigation bar when scrolling down (bootstrap3)

For those not willing to use jQuery here is a Vanilla Javascript way of doing the same using classList:

function runOnScroll() {
    var element = document.getElementsByTagName('nav')  ;
    if(document.body.scrollTop >= 50) {
        element[0].classList.add('shrink')
    } else {
        element[0].classList.remove('shrink')
    }
    console.log(topMenu[0].classList)

};

There might be a nicer way of doing it using toggle, but the above works fine in Chrome

Efficient Algorithm for Bit Reversal (from MSB->LSB to LSB->MSB) in C

Bit reversal in pseudo code

source -> byte to be reversed b00101100 destination -> reversed, also needs to be of unsigned type so sign bit is not propogated down

copy into temp so original is unaffected, also needs to be of unsigned type so that sign bit is not shifted in automaticaly

bytecopy = b0010110

LOOP8: //do this 8 times test if bytecopy is < 0 (negative)

    set bit8 (msb) of reversed = reversed | b10000000 

else do not set bit8

shift bytecopy left 1 place
bytecopy = bytecopy << 1 = b0101100 result

shift result right 1 place
reversed = reversed >> 1 = b00000000
8 times no then up^ LOOP8
8 times yes then done.

How do I format axis number format to thousands with a comma in matplotlib?

You can use matplotlib.ticker.funcformatter

import numpy as np
import matplotlib.pyplot as plt
import matplotlib.ticker as tkr


def func(x, pos):  # formatter function takes tick label and tick position
    s = '%d' % x
    groups = []
    while s and s[-1].isdigit():
        groups.append(s[-3:])
        s = s[:-3]
    return s + ','.join(reversed(groups))

y_format = tkr.FuncFormatter(func)  # make formatter

x = np.linspace(0,10,501)
y = 1000000*np.sin(x)
ax = plt.subplot(111)
ax.plot(x,y)
ax.yaxis.set_major_formatter(y_format)  # set formatter to needed axis

plt.show()

enter image description here

How do you add an SDK to Android Studio?

You have to put your SDK's in a given directory or .app directory. You have to do it in finder while you are out of the application i'm assuming, but personally I'd use terminal in Mac instead of doing it in the App itself or finder. According to Google:

On Windows and Mac, the individual tools and other SDK packages are saved within the Android Studio application directory. To access the tools directly, use a terminal to navigate into the application and locate the sdk/ directory. For example:

 Windows: \Users\<user>\AppData\Local\Android\android-studio\sdk\
 Mac: /Applications/Android\ Studio.app/sdk/

$on and $broadcast in angular

First, a short description of $on(), $broadcast() and $emit():

  • .$on(name, listener) - Listens for a specific event by a given name
  • .$broadcast(name, args) - Broadcast an event down through the $scope of all children
  • .$emit(name, args) - Emit an event up the $scope hierarchy to all parents, including the $rootScope

Based on the following HTML (see full example here):

<div ng-controller="Controller1">
    <button ng-click="broadcast()">Broadcast 1</button>
    <button ng-click="emit()">Emit 1</button>
</div>

<div ng-controller="Controller2">
    <button ng-click="broadcast()">Broadcast 2</button>
    <button ng-click="emit()">Emit 2</button>
    <div ng-controller="Controller3">
        <button ng-click="broadcast()">Broadcast 3</button>
        <button ng-click="emit()">Emit 3</button>
        <br>
        <button ng-click="broadcastRoot()">Broadcast Root</button>
        <button ng-click="emitRoot()">Emit Root</button>
    </div>
</div>

The fired events will traverse the $scopes as follows:

  • Broadcast 1 - Will only be seen by Controller 1 $scope
  • Emit 1 - Will be seen by Controller 1 $scope then $rootScope
  • Broadcast 2 - Will be seen by Controller 2 $scope then Controller 3 $scope
  • Emit 2 - Will be seen by Controller 2 $scope then $rootScope
  • Broadcast 3 - Will only be seen by Controller 3 $scope
  • Emit 3 - Will be seen by Controller 3 $scope, Controller 2 $scope then $rootScope
  • Broadcast Root - Will be seen by $rootScope and $scope of all the Controllers (1, 2 then 3)
  • Emit Root - Will only be seen by $rootScope

JavaScript to trigger events (again, you can see a working example here):

app.controller('Controller1', ['$scope', '$rootScope', function($scope, $rootScope){
    $scope.broadcastAndEmit = function(){
        // This will be seen by Controller 1 $scope and all children $scopes 
        $scope.$broadcast('eventX', {data: '$scope.broadcast'});

        // Because this event is fired as an emit (goes up) on the $rootScope,
        // only the $rootScope will see it
        $rootScope.$emit('eventX', {data: '$rootScope.emit'});
    };
    $scope.emit = function(){
        // Controller 1 $scope, and all parent $scopes (including $rootScope) 
        // will see this event
        $scope.$emit('eventX', {data: '$scope.emit'});
    };

    $scope.$on('eventX', function(ev, args){
        console.log('eventX found on Controller1 $scope');
    });
    $rootScope.$on('eventX', function(ev, args){
        console.log('eventX found on $rootScope');
    });
}]);

What Ruby IDE do you prefer?

While TextMate is not an IDE in the classical sense, try the following in terminal to be 'wowed'

cd 'your-shiny-ruby-project'
mate .

It'll spawn up TextMate and the project drawer will list the contents of your project. Pretty awesome if you ask me.

How do I check the difference, in seconds, between two dates?

Here's the one that is working for me.

from datetime import datetime

date_format = "%H:%M:%S"

# You could also pass datetime.time object in this part and convert it to string.
time_start = str('09:00:00') 
time_end = str('18:00:00')

# Then get the difference here.    
diff = datetime.strptime(time_end, date_format) - datetime.strptime(time_start, date_format)

# Get the time in hours i.e. 9.60, 8.5
result = diff.seconds / 3600;

Hope this helps!

Setting width as a percentage using jQuery

Hemnath

If your variable is the percentage:

var myWidth = 70;
$('div#somediv').width(myWidth + '%');

If your variable is in pixels, and you want the percentage it take up of the parent:

var myWidth = 140;
var myPercentage = (myWidth / $('div#somediv').parent().width()) * 100;
$('div#somediv').width(myPercentage + '%');

UILabel - Wordwrap text

UILabel has a property lineBreakMode that you can set as per your requirement.

Python Binomial Coefficient

What about this one? :) It uses correct formula, avoids math.factorial and takes less multiplication operations:

import math
import operator
product = lambda m,n: reduce(operator.mul, xrange(m, n+1), 1)
x = max(0, int(input("Enter a value for x: ")))
y = max(0, int(input("Enter a value for y: ")))
print product(y+1, x) / product(1, x-y)

Also, in order to avoid big-integer arithmetics you may use floating point numbers, convert product(a[i])/product(b[i]) to product(a[i]/b[i]) and rewrite the above program as:

import math
import operator
product = lambda iterable: reduce(operator.mul, iterable, 1)
x = max(0, int(input("Enter a value for x: ")))
y = max(0, int(input("Enter a value for y: ")))
print product(map(operator.truediv, xrange(y+1, x+1), xrange(1, x-y+1)))

C# Java HashMap equivalent

Check out the documentation on MSDN for the Hashtable class.

Represents a collection of key-and-value pairs that are organized based on the hash code of the key.

Also, keep in mind that this is not thread-safe.

Detect if the app was launched/opened from a push notification

IN SWIFT:

I'm running Push Notifications (with background fetching). When my app is in the background and I receive a push notification, I found that didReceiveRemoteNotification in appDelegate would be called twice; once for when notification is received and another when user clicks on the notification alert.

To detect if notification alert was clicked, just check if applicationState raw value == 1 inside didReceiveRemoteNotification in appDelegate.

func application(application: UIApplication, didReceiveRemoteNotification userInfo: [NSObject: AnyObject]) {
    // If not from alert click applicationState(1)
    if (application.applicationState.rawValue != 1) {
        // Run your code here
    }
}

I hope this helps.

Insert null/empty value in sql datetime column by default

if there is no value inserted, the default value should be null,empty

In the table definition, make this datetime column allows null, be not defining NOT NULL:

...
DateTimeColumn DateTime,
...

I HAVE ALLOWED NULL VARIABLES THOUGH.

Then , just insert NULL in this column:

INSERT INTO Table(name, datetimeColumn, ...)
VALUES('foo bar', NULL, ..);

Or, you can make use of the DEFAULT constaints:

...
DateTimeColumn DateTime DEFAULT NULL,
...

Then you can ignore it completely in the INSERT statement and it will be inserted withe the NULL value:

INSERT INTO Table(name, ...)
VALUES('foo bar', ..);

Django. Override save for model

Some thoughts:

class Model(model.Model):
    _image=models.ImageField(upload_to='folder')
    thumb=models.ImageField(upload_to='folder')
    description=models.CharField()

    def set_image(self, val):
        self._image = val
        self._image_changed = True

        # Or put whole logic in here
        small = rescale_image(self.image,width=100,height=100)
        self.image_small=SimpleUploadedFile(name,small_pic)

    def get_image(self):
        return self._image

    image = property(get_image, set_image)

    # this is not needed if small_image is created at set_image
    def save(self, *args, **kwargs):
        if getattr(self, '_image_changed', True):
            small=rescale_image(self.image,width=100,height=100)
            self.image_small=SimpleUploadedFile(name,small_pic)
        super(Model, self).save(*args, **kwargs)

Not sure if it would play nice with all pseudo-auto django tools (Example: ModelForm, contrib.admin etc).

How do I get the scroll position of a document?

Try this:

var scrollHeight = $(scrollable)[0] == document ? document.body.scrollHeight : $(scrollable)[0].scrollHeight;

Parsing a comma-delimited std::string

The C++ String Toolkit Library (Strtk) has the following solution to your problem:

#include <string>
#include <deque>
#include <vector>
#include "strtk.hpp"
int main()
{ 
   std::string int_string = "1,2,3,4,5,6,7,8,9,10,11,12,13,14,15";
   std::vector<int> int_list;
   strtk::parse(int_string,",",int_list);

   std::string double_string = "123.456|789.012|345.678|901.234|567.890";
   std::deque<double> double_list;
   strtk::parse(double_string,"|",double_list);

   return 0;
}

More examples can be found Here

How do you wait for input on the same Console.WriteLine() line?

Use Console.Write instead, so there's no newline written:

Console.Write("What is your name? ");
var name = Console.ReadLine();

Installed Ruby 1.9.3 with RVM but command line doesn't show ruby -v

  • Open Terminal.
  • Go to Edit -> Profile Preferences.
  • Select the Title & command Tab in the window opened.
  • Mark the checkbox Run command as login shell.
  • close the window and restart the Terminal.

Check this Official Linkenter image description here

How to enable Logger.debug() in Log4j

I like to use a rolling file appender to write the logging info to a file. My log4j properties file typically looks something like this. I prefer this way since I like to make package specific logging in case I need varying degrees of logging for different packages. Only one package is mentioned in the example.

log4j.appender.RCS=org.apache.log4j.DailyRollingFileAppender
log4j.appender.RCS.File.DateFormat='.'yyyy-ww
#define output location
log4j.appender.RCS.File=C:temp/logs/MyService.log
#define the file layout
log4j.appender.RCS.layout=org.apache.log4j.PatternLayout
log4j.appender.RCS.layout.ConversionPattern=%d{yyyy-MM-dd hh:mm a} %5 %c{1}: Line#%L - %m%n
log4j.rootLogger=warn
#Define package specific logging
log4j.logger.MyService=debug, RCS

Adding a y-axis label to secondary y-axis in matplotlib

The best way is to interact with the axes object directly

import numpy as np
import matplotlib.pyplot as plt
x = np.arange(0, 10, 0.1)
y1 = 0.05 * x**2
y2 = -1 *y1

fig, ax1 = plt.subplots()

ax2 = ax1.twinx()
ax1.plot(x, y1, 'g-')
ax2.plot(x, y2, 'b-')

ax1.set_xlabel('X data')
ax1.set_ylabel('Y1 data', color='g')
ax2.set_ylabel('Y2 data', color='b')

plt.show()

example graph

How to insert a line break <br> in markdown

I know this post is about adding a single line break but I thought I would mention that you can create multiple line breaks with the backslash (\) character:

Hello
\
\
\
World!

This would result in 3 new lines after "Hello". To clarify, that would mean 2 empty lines between "Hello" and "World!". It would display like this:


Hello



World!



Personally I find this cleaner for a large number of line breaks compared to using <br>.

Note that backslashes are not recommended for compatibility reasons. So this may not be supported by your Markdown parser but it's handy when it is.

Write to custom log file from a Bash script

There's good amount of detail on logging for shell scripts via global varaibles of shell. We can emulate the similar kind of logging in shell script: http://www.cubicrace.com/2016/03/efficient-logging-mechnism-in-shell.html The post has details on introdducing log levels like INFO , DEBUG, ERROR. Tracing details like script entry, script exit, function entry, function exit.

Sample Log: enter image description here

How to find encoding of a file via script on Linux?

I know you're interested in a more general answer, but what's good in ASCII is usually good in other encodings. Here is a Python one-liner to determine if standard input is ASCII. (I'm pretty sure this works in Python 2, but I've only tested it on Python 3.)

python -c 'from sys import exit,stdin;exit()if 128>max(c for l in open(stdin.fileno(),"b") for c in l) else exit("Not ASCII")' < myfile.txt

'AND' vs '&&' as operator

For safety, I always parenthesise my comparisons and space them out. That way, I don't have to rely on operator precedence:

if( 
    ((i==0) && (b==2)) 
    || 
    ((c==3) && !(f==5)) 
  )

Use multiple custom fonts using @font-face?

I use this method in my css file

@font-face {
  font-family: FontName1;
  src: url("fontname1.eot"); /* IE */
  src: local('FontName1'), url('fontname1.ttf') format('truetype'); /* others */
}
@font-face {
  font-family: FontName2;
  src: url("fontname1.eot"); /* IE */
  src: local('FontName2'), url('fontname2.ttf') format('truetype'); /* others */
}
@font-face {
  font-family: FontName3;
  src: url("fontname1.eot"); /* IE */
  src: local('FontName3'), url('fontname3.ttf') format('truetype'); /* others */
}

How to get an Android WakeLock to work?

You just have to write this:

 private PowerManager.WakeLock wl;

    protected void onCreate(Bundle savedInstanceState) {
               super.onCreate(savedInstanceState);
            setContentView(R.layout.main);

            PowerManager pm = (PowerManager) getSystemService(Context.POWER_SERVICE);
            wl = pm.newWakeLock(PowerManager.FULL_WAKE_LOCK, "DoNjfdhotDimScreen");
    }//End of onCreate

            @Override
        protected void onPause() {
            super.onPause();
            wl.release();
        }//End of onPause

        @Override
        protected void onResume() {
            super.onResume();
            wl.acquire();
        }//End of onResume

and then add permission in the manifest file

 <uses-permission android:name="android.permission.WAKE_LOCK" />

Now your activity will always be awake. You can do other things like w1.release() as per your requirement.

What's the difference between window.location= and window.location.replace()?

TLDR;

use location.href or better use window.location.href;

However if you read this you will gain undeniable proof.

The truth is it's fine to use but why do things that are questionable. You should take the higher road and just do it the way that it probably should be done.

location = "#/mypath/otherside"
var sections = location.split('/')

This code is perfectly correct syntax-wise, logic wise, type-wise you know the only thing wrong with it?

it has location instead of location.href

what about this

var mystring = location = "#/some/spa/route"

what is the value of mystring? does anyone really know without doing some test. No one knows what exactly will happen here. Hell I just wrote this and I don't even know what it does. location is an object but I am assigning a string will it pass the string or pass the location object. Lets say there is some answer to how this should be implemented. Can you guarantee all browsers will do the same thing?

This i can pretty much guess all browsers will handle the same.

var mystring = location.href = "#/some/spa/route"

What about if you place this into typescript will it break because the type compiler will say this is suppose to be an object?

This conversation is so much deeper than just the location object however. What this conversion is about what kind of programmer you want to be?

If you take this short-cut, yea it might be okay today, ye it might be okay tomorrow, hell it might be okay forever, but you sir are now a bad programmer. It won't be okay for you and it will fail you.

There will be more objects. There will be new syntax.

You might define a getter that takes only a string but returns an object and the worst part is you will think you are doing something correct, you might think you are brilliant for this clever method because people here have shamefully led you astray.

var Person.name = {first:"John":last:"Doe"}
console.log(Person.name) // "John Doe"

With getters and setters this code would actually work, but just because it can be done doesn't mean it's 'WISE' to do so.

Most people who are programming love to program and love to get better. Over the last few years I have gotten quite good and learn a lot. The most important thing I know now especially when you write Libraries is consistency and predictability.

Do the things that you can consistently do.

+"2" <-- this right here parses the string to a number. should you use it? or should you use parseInt("2")?

what about var num =+"2"?

From what you have learn, from the minds of stackoverflow i am not too hopefully.

If you start following these 2 words consistent and predictable. You will know the right answer to a ton of questions on stackoverflow.

Let me show you how this pays off. Normally I place ; on every line of javascript i write. I know it's more expressive. I know it's more clear. I have followed my rules. One day i decided not to. Why? Because so many people are telling me that it is not needed anymore and JavaScript can do without it. So what i decided to do this. Now because I have become sure of my self as a programmer (as you should enjoy the fruit of mastering a language) i wrote something very simple and i didn't check it. I erased one comma and I didn't think I needed to re-test for such a simple thing as removing one comma.

I wrote something similar to this in es6 and babel

var a = "hello world"
(async function(){
  //do work
})()

This code fail and took forever to figure out. For some reason what it saw was

var a = "hello world"(async function(){})()

hidden deep within the source code it was telling me "hello world" is not a function.

For more fun node doesn't show the source maps of transpiled code.

Wasted so much stupid time. I was presenting to someone as well about how ES6 is brilliant and then I had to start debugging and demonstrate how headache free and better ES6 is. Not convincing is it.

I hope this answered your question. This being an old question it's more for the future generation, people who are still learning.

Question when people say it doesn't matter either way works. Chances are a wiser more experienced person will tell you other wise.

what if someone overwrite the location object. They will do a shim for older browsers. It will get some new feature that needs to be shimmed and your 3 year old code will fail.

My last note to ponder upon.

Writing clean, clear purposeful code does something for your code that can't be answer with right or wrong. What it does is it make your code an enabler.

You can use more things plugins, Libraries with out fear of interruption between the codes.

for the record. use

window.location.href

Stop absolutely positioned div from overlapping text

_x000D_
_x000D_
<div style="position: relative; width:600px;">_x000D_
        <p>Content of unknown length</p>_x000D_
        <div>Content of unknown height</div>_x000D_
        <div id="spacer" style="width: 200px; height: 100px; float:left; display:inline-block"></div>_x000D_
        <div class="btn" style="position: absolute; right: 0; bottom: 0; width: 200px; height: 100px;"></div>_x000D_
    </div>
_x000D_
_x000D_
_x000D_

This should be a comment but I don't have enough reputation yet. The solution works, but visual studio code told me the following putting it into a css sheet:

inline-block is ignored due to the float. If 'float' has a value other than 'none', the box is floated and 'display' is treated as 'block'

So I did it like this

.spacer {
    float: left;
    height: 20px;
    width: 200px;
}

And it works just as well.

CSS width of a <span> tag

Like in other answers, start your span attributes with this:

display:inline-block;  

Now you can use padding more than width:

padding-left:6%;
padding-right:6%;

When you use padding, your color expands to both side (right and left), not just right (like in widht).

In CSS what is the difference between "." and "#" when declaring a set of styles?

The # means that it matches the id of an element. The . signifies the class name:

<div id="myRedText">This will be red.</div>
<div class="blueText">this will be blue.</div>


#myRedText {
    color: red;
}
.blueText {
    color: blue;
}

Note that in a HTML document, the id attribute must be unique, so if you have more than one element needing a specific style, you should use a class name.

Generic List - moving an item within the list

I would expect either:

// Makes sure item is at newIndex after the operation
T item = list[oldIndex];
list.RemoveAt(oldIndex);
list.Insert(newIndex, item);

... or:

// Makes sure relative ordering of newIndex is preserved after the operation, 
// meaning that the item may actually be inserted at newIndex - 1 
T item = list[oldIndex];
list.RemoveAt(oldIndex);
newIndex = (newIndex > oldIndex ? newIndex - 1, newIndex)
list.Insert(newIndex, item);

... would do the trick, but I don't have VS on this machine to check.

How to convert Nonetype to int or string?

In one of the comments, you say:

Somehow I got an Nonetype value, it supposed to be an int, but it's now a Nonetype object

If it's your code, figure out how you're getting None when you expect a number and stop that from happening.

If it's someone else's code, find out the conditions under which it gives None and determine a sensible value to use for that, with the usual conditional code:

result = could_return_none(x)

if result is None:
    result = DEFAULT_VALUE

...or even...

if x == THING_THAT_RESULTS_IN_NONE:
    result = DEFAULT_VALUE
else:
    result = could_return_none(x) # But it won't return None, because we've restricted the domain.

There's no reason to automatically use 0 here — solutions that depend on the "false"-ness of None assume you will want this. The DEFAULT_VALUE (if it even exists) completely depends on your code's purpose.

How to show matplotlib plots in python

Save the plot as png

plt.savefig("temp.png")

How to prevent XSS with HTML/PHP?

In order of preference:

  1. If you are using a templating engine (e.g. Twig, Smarty, Blade), check that it offers context-sensitive escaping. I know from experience that Twig does. {{ var|e('html_attr') }}
  2. If you want to allow HTML, use HTML Purifier. Even if you think you only accept Markdown or ReStructuredText, you still want to purify the HTML these markup languages output.
  3. Otherwise, use htmlentities($var, ENT_QUOTES | ENT_HTML5, $charset) and make sure the rest of your document uses the same character set as $charset. In most cases, 'UTF-8' is the desired character set.

Also, make sure you escape on output, not on input.

CORS Access-Control-Allow-Headers wildcard being ignored?

I found that Access-Control-Allow-Headers: * should be set ONLY for OPTIONS request. If you return it for POST request then browser cancel the request (at least for chrome)

The following PHP code works for me

// Allow CORS
if (isset($_SERVER['HTTP_ORIGIN'])) {
    header("Access-Control-Allow-Origin: {$_SERVER['HTTP_ORIGIN']}");
    header('Access-Control-Allow-Credentials: true');    
    header("Access-Control-Allow-Methods: GET, POST, OPTIONS"); 
}   
// Access-Control headers are received during OPTIONS requests
if ($_SERVER['REQUEST_METHOD'] == 'OPTIONS') {
    header("Access-Control-Allow-Headers: *");
}

I found similar questions with some misleading response:

  • Server thread says that this is 2 years bug of chrome: Access-Control-Allow-Headers does not match with localhost. It's wrong: I can use CORS to my local server with Post normally
  • Access-Control-Allow-Headers does accept wildcards. It's also wrong, wildcard works for me (I tested only with Chrome)

This take me half day to figure out the issue.

Happy coding

autocomplete ='off' is not working when the input type is password and make the input field above it to enable autocomplete

I've found that if the input has no name (e.g. the name attribute is not set), the browser can't autocomplete the field. I know this is not a solution for everyone, but if you submit your form through AJAX, you may try this.

Convert String to SecureString

I'll throw this out there. Why?

You can't just change all your strings to secure strings and suddenly your application is "secure". Secure string is designed to keep the string encrypted for as long as possible, and only decrypted for a very short period of time, wiping the memory after an operation has been performed upon it.

I would hazard saying that you may have some design level issues to deal with before worrying about securing your application strings. Give us some more information on what your trying to do and we may be able to help better.

maxFileSize and acceptFileTypes in blueimp file upload plugin do not work. Why?

If you've got all the plugin JS's imported and in the correct order, but you're still having issues, it seems that specifying your own "add" handler nerfs the one from the *-validate.js plugin, which normally would fire off all the validation by calling data.process(). So to fix it just do something like this in your "add" event handler:

$('#whatever').fileupload({
...
add: function(e, data) {
   var $this = $(this);
   data.process(function() {
      return $this.fileupload('process', data);
   }).done(function(){
      //do success stuff
      data.submit(); <-- fire off the upload to the server
   }).fail(function() {
      alert(data.files[0].error);
   });
}
...
});

Import MySQL database into a MS SQL Server

I had a very similar issue today - I needed to copy a big table(5 millions rows) from MySql into MS SQL.

Here are the steps I've done(under Ubuntu Linux):

  1. Created a table in MS SQL which structure matches the source table in MySql.

  2. Installed MS SQL command line: https://docs.microsoft.com/en-us/sql/linux/sql-server-linux-setup-tools#ubuntu

  3. Dumped table from MySql to a file:

mysqldump \
    --compact \
    --complete-insert \
    --no-create-info \
    --compatible=mssql \
    --extended-insert=FALSE \
    --host "$MYSQL_HOST" \
    --user "$MYSQL_USER" \
    -p"$MYSQL_PASS" \
    "$MYSQL_DB" \
    "$TABLE" > "$FILENAME"
  1. In my case the dump file was quite large, so I decided to split it into a number of small pieces(1000 lines each) - split --lines=1000 "$FILENAME" part-

  2. Finally I iterated over these small files, did some text replacements, and executed the pieces one by one against MS SQL server:

export SQLCMD=/opt/mssql-tools/bin/sqlcmd

x=0

for file in part-*
do
  echo "Exporting file [$file] into MS SQL. $x thousand(s) processed"

  # replaces \' with ''
  sed -i "s/\\\'/''/g" "$file"

  # removes all "
  sed -i 's/"//g' "$file"

  # allows to insert records with specified PK(id)
  sed -i "1s/^/SET IDENTITY_INSERT $TABLE ON;\n/" "$file"

  "$SQLCMD" -S "$AZURE_SERVER" -d "$AZURE_DB" -U "$AZURE_USER" -P "$AZURE_PASS" -i "$file"
  echo ""
  echo ""

  x=$((x+1))
done

echo "Done"

Of course you'll need to replace my variables like $AZURE_SERVER, $TABLE , e.t.c. with yours.

Hope that helps.

ENOENT, no such file or directory

  1. First try npm install ,if the issue is not yet fixed try the following one after the other.
  2. npm cache clean ,then
  3. npm install -g npm,then npm install,Finally
  4. ng serve --o to run the project. Hope this will help....

How can I go back/route-back on vue-router?

Use router.back() directly to go back/route-back programmatic on vue-router.

How to edit the legend entry of a chart in Excel?

There are 3 ways to do this:

1. Define the Series names directly

Right-click on the Chart and click Select Data then edit the series names directly as shown below.

enter image description here

You can either specify the values directly e.g. Series 1 or specify a range e.g. =A2

enter image description here

2. Create a chart defining upfront the series and axis labels

Simply select your data range (in similar format as I specified) and create a simple bar chart. The labels should be defined automatically. enter image description here

3. Define the legend (series names) using VBA

Similarly you can define the series names dynamically using VBA. A simple example below:

ActiveChart.ChartArea.Select
ActiveChart.FullSeriesCollection(1).Name = "=""Hello"""

This will redefine the first series name. Just change the index from (1) to e.g. (2) and so on to change the following series names. What does the VBA above do? It sets the series name to Hello as "=""Hello""" translates to ="Hello" (" have to be escaped by a preceding ").

target input by type and name (selector)

input[type='checkbox', name='ProductCode']

That's the CSS way and I'm almost sure it will work in jQuery.

pandas create new column based on values from other columns / apply a function of multiple columns, row-wise

Since this is the first Google result for 'pandas new column from others', here's a simple example:

import pandas as pd

# make a simple dataframe
df = pd.DataFrame({'a':[1,2], 'b':[3,4]})
df
#    a  b
# 0  1  3
# 1  2  4

# create an unattached column with an index
df.apply(lambda row: row.a + row.b, axis=1)
# 0    4
# 1    6

# do same but attach it to the dataframe
df['c'] = df.apply(lambda row: row.a + row.b, axis=1)
df
#    a  b  c
# 0  1  3  4
# 1  2  4  6

If you get the SettingWithCopyWarning you can do it this way also:

fn = lambda row: row.a + row.b # define a function for the new column
col = df.apply(fn, axis=1) # get column data with an index
df = df.assign(c=col.values) # assign values to column 'c'

Source: https://stackoverflow.com/a/12555510/243392

And if your column name includes spaces you can use syntax like this:

df = df.assign(**{'some column name': col.values})

And here's the documentation for apply, and assign.

SQL join: selecting the last records in a one-to-many relationship

You haven't specified the database. If it is one that allows analytical functions it may be faster to use this approach than the GROUP BY one(definitely faster in Oracle, most likely faster in the late SQL Server editions, don't know about others).

Syntax in SQL Server would be:

SELECT c.*, p.*
FROM customer c INNER JOIN 
     (SELECT RANK() OVER (PARTITION BY customer_id ORDER BY date DESC) r, *
             FROM purchase) p
ON (c.id = p.customer_id)
WHERE p.r = 1

What does the "map" method do in Ruby?

Using ruby 2.4 you can do the same thing using transform_values, this feature extracted from rails to ruby.

h = {a: 1, b: 2, c: 3}

h.transform_values { |v| v * 10 }
 #=> {a: 10, b: 20, c: 30}

How to access property of anonymous type in C#?

The accepted answer correctly describes how the list should be declared and is highly recommended for most scenarios.

But I came across a different scenario, which also covers the question asked. What if you have to use an existing object list, like ViewData["htmlAttributes"] in MVC? How can you access its properties (they are usually created via new { @style="width: 100px", ... })?

For this slightly different scenario I want to share with you what I found out. In the solutions below, I am assuming the following declaration for nodes:

List<object> nodes = new List<object>();

nodes.Add(
new
{
    Checked = false,
    depth = 1,
    id = "div_1" 
});

1. Solution with dynamic

In C# 4.0 and higher versions, you can simply cast to dynamic and write:

if (nodes.Any(n => ((dynamic)n).Checked == false))
    Console.WriteLine("found a  not checked  element!");

Note: This is using late binding, which means it will recognize only at runtime if the object doesn't have a Checked property and throws a RuntimeBinderException in this case - so if you try to use a non-existing Checked2 property you would get the following message at runtime: "'<>f__AnonymousType0<bool,int,string>' does not contain a definition for 'Checked2'".

2. Solution with reflection

The solution with reflection works both with old and new C# compiler versions. For old C# versions please regard the hint at the end of this answer.

Background

As a starting point, I found a good answer here. The idea is to convert the anonymous data type into a dictionary by using reflection. The dictionary makes it easy to access the properties, since their names are stored as keys (you can access them like myDict["myProperty"]).

Inspired by the code in the link above, I created an extension class providing GetProp, UnanonymizeProperties and UnanonymizeListItems as extension methods, which simplify access to anonymous properties. With this class you can simply do the query as follows:

if (nodes.UnanonymizeListItems().Any(n => (bool)n["Checked"] == false))
{
    Console.WriteLine("found a  not checked  element!");
}

or you can use the expression nodes.UnanonymizeListItems(x => (bool)x["Checked"] == false).Any() as if condition, which filters implicitly and then checks if there are any elements returned.

To get the first object containing "Checked" property and return its property "depth", you can use:

var depth = nodes.UnanonymizeListItems()
             ?.FirstOrDefault(n => n.Contains("Checked")).GetProp("depth");

or shorter: nodes.UnanonymizeListItems()?.FirstOrDefault(n => n.Contains("Checked"))?["depth"];

Note: If you have a list of objects which don't necessarily contain all properties (for example, some do not contain the "Checked" property), and you still want to build up a query based on "Checked" values, you can do this:

if (nodes.UnanonymizeListItems(x => { var y = ((bool?)x.GetProp("Checked", true)); 
                                      return y.HasValue && y.Value == false;}).Any())
{
    Console.WriteLine("found a  not checked   element!");
}

This prevents, that a KeyNotFoundException occurs if the "Checked" property does not exist.


The class below contains the following extension methods:

  • UnanonymizeProperties: Is used to de-anonymize the properties contained in an object. This method uses reflection. It converts the object into a dictionary containing the properties and its values.
  • UnanonymizeListItems: Is used to convert a list of objects into a list of dictionaries containing the properties. It may optionally contain a lambda expression to filter beforehand.
  • GetProp: Is used to return a single value matching the given property name. Allows to treat not-existing properties as null values (true) rather than as KeyNotFoundException (false)

For the examples above, all that is required is that you add the extension class below:

public static class AnonymousTypeExtensions
{
    // makes properties of object accessible 
    public static IDictionary UnanonymizeProperties(this object obj)
    {
        Type type = obj?.GetType();
        var properties = type?.GetProperties()
               ?.Select(n => n.Name)
               ?.ToDictionary(k => k, k => type.GetProperty(k).GetValue(obj, null));
        return properties;
    }
    
    // converts object list into list of properties that meet the filterCriteria
    public static List<IDictionary> UnanonymizeListItems(this List<object> objectList, 
                    Func<IDictionary<string, object>, bool> filterCriteria=default)
    {
        var accessibleList = new List<IDictionary>();
        foreach (object obj in objectList)
        {
            var props = obj.UnanonymizeProperties();
            if (filterCriteria == default
               || filterCriteria((IDictionary<string, object>)props) == true)
            { accessibleList.Add(props); }
        }
        return accessibleList;
    }

    // returns specific property, i.e. obj.GetProp(propertyName)
    // requires prior usage of AccessListItems and selection of one element, because
    // object needs to be a IDictionary<string, object>
    public static object GetProp(this object obj, string propertyName, 
                                 bool treatNotFoundAsNull = false)
    {
        try 
        {
            return ((System.Collections.Generic.IDictionary<string, object>)obj)
                   ?[propertyName];
        }
        catch (KeyNotFoundException)
        {
            if (treatNotFoundAsNull) return default(object); else throw;
        }
    }
}

Hint: The code above is using the null-conditional operators, available since C# version 6.0 - if you're working with older C# compilers (e.g. C# 3.0), simply replace ?. by . and ?[ by [ everywhere (and do the null-handling traditionally by using if statements or catch NullReferenceExceptions), e.g.

var depth = nodes.UnanonymizeListItems()
            .FirstOrDefault(n => n.Contains("Checked"))["depth"];

As you can see, the null-handling without the null-conditional operators would be cumbersome here, because everywhere you removed them you have to add a null check - or use catch statements where it is not so easy to find the root cause of the exception resulting in much more - and hard to read - code.

If you're not forced to use an older C# compiler, keep it as is, because using null-conditionals makes null handling much easier.

Note: Like the other solution with dynamic, this solution is also using late binding, but in this case you're not getting an exception - it will simply not find the element if you're referring to a non-existing property, as long as you keep the null-conditional operators.

What might be useful for some applications is that the property is referred to via a string in solution 2, hence it can be parameterized.

Vue - Deep watching an array of objects and calculating the change?

Your comparison function between old value and new value is having some issue. It is better not to complicate things so much, as it will increase your debugging effort later. You should keep it simple.

The best way is to create a person-component and watch every person separately inside its own component, as shown below:

<person-component :person="person" v-for="person in people"></person-component>

Please find below a working example for watching inside person component. If you want to handle it on parent side, you may use $emit to send an event upwards, containing the id of modified person.

_x000D_
_x000D_
Vue.component('person-component', {_x000D_
    props: ["person"],_x000D_
    template: `_x000D_
        <div class="person">_x000D_
            {{person.name}}_x000D_
            <input type='text' v-model='person.age'/>_x000D_
        </div>`,_x000D_
    watch: {_x000D_
        person: {_x000D_
            handler: function(newValue) {_x000D_
                console.log("Person with ID:" + newValue.id + " modified")_x000D_
                console.log("New age: " + newValue.age)_x000D_
            },_x000D_
            deep: true_x000D_
        }_x000D_
    }_x000D_
});_x000D_
_x000D_
new Vue({_x000D_
    el: '#app',_x000D_
    data: {_x000D_
        people: [_x000D_
          {id: 0, name: 'Bob', age: 27},_x000D_
          {id: 1, name: 'Frank', age: 32},_x000D_
          {id: 2, name: 'Joe', age: 38}_x000D_
        ]_x000D_
    }_x000D_
});
_x000D_
<script src="https://unpkg.com/[email protected]/dist/vue.js"></script>_x000D_
<body>_x000D_
    <div id="app">_x000D_
        <p>List of people:</p>_x000D_
        <person-component :person="person" v-for="person in people"></person-component>_x000D_
    </div>_x000D_
</body>
_x000D_
_x000D_
_x000D_

String.replaceAll single backslashes with double backslashes

The String#replaceAll() interprets the argument as a regular expression. The \ is an escape character in both String and regex. You need to double-escape it for regex:

string.replaceAll("\\\\", "\\\\\\\\");

But you don't necessarily need regex for this, simply because you want an exact character-by-character replacement and you don't need patterns here. So String#replace() should suffice:

string.replace("\\", "\\\\");

Update: as per the comments, you appear to want to use the string in JavaScript context. You'd perhaps better use StringEscapeUtils#escapeEcmaScript() instead to cover more characters.

iOS for VirtualBox

You could try qemu, which is what the Android emulator uses. I believe it actually emulates the ARM hardware.

Clicking the back button twice to exit an activity

private static final int TIME_INTERVAL = 2000;
private long mBackPressed;
    @Override
        public void onBackPressed() {

            if (mBackPressed + TIME_INTERVAL > System.currentTimeMillis()) {
                super.onBackPressed();
                Intent intent = new Intent(FirstpageActivity.this,
                        HomepageActivity.class);
                startActivity(intent);
                finish();

                return;
            } else {

                Toast.makeText(getBaseContext(),
                        "Tap back button twice  to go Home.", Toast.LENGTH_SHORT)
                        .show();

                mBackPressed = System.currentTimeMillis();

            }

        }

Angularjs simple file download causes router to redirect

in template

<md-button class="md-fab md-mini md-warn md-ink-ripple" ng-click="export()" aria-label="Export">
<md-icon class="material-icons" alt="Export" title="Export" aria-label="Export">
    system_update_alt
</md-icon></md-button>

in controller

     $scope.export = function(){ $window.location.href = $scope.export; };

Javascript loading CSV file into an array

You can't use AJAX to fetch files from the user machine. This is absolutely the wrong way to go about it.

Use the FileReader API:

<input type="file" id="file input">

js:

console.log(document.getElementById("file input").files); // list of File objects

var file = document.getElementById("file input").files[0];
var reader = new FileReader();
content = reader.readAsText(file);
console.log(content);

Then parse content as CSV. Keep in mind that your parser currently does not deal with escaped values in CSV like: value1,value2,"value 3","value ""4"""

What's the best way to do a backwards loop in C/C#/C++?

In C# using Linq:

foreach(var item in myArray.Reverse())
{
    // do something
}

Tool for comparing 2 binary files in Windows

In Cygwin:

$cmp -bl <file1> <file2>

diffs binary offsets and values are in decimal and octal respectively.. Vladi.

How can I set a custom date time format in Oracle SQL Developer?

With Oracle SQL Developer 3.2.20.09, i managed to set the custom format for the type DATE this way :

In : Tools > Preferences > Database > NLS

Or : Outils > Préférences > Base de donées > NLS

YYYY-MM-DD HH24:MI:SS

Settings Menu screenshot

Note that the following format does not worked for me :

DD-MON-RR HH24:MI:SS

As a result, it keeps the default format, without any error.

java.lang.NoClassDefFoundError:failed resolution of :Lorg/apache/http/ProtocolVersion

In react native, I had the error not show maps and close app, run adb logcat and show error within console:

java.lang.NoClassDefFoundError:failed resolution of :Lorg/apache/http/ProtocolVersion

fix it by adding within androidManifest.xml

<uses-library
  android:name="org.apache.http.legacy"
  android:required="false" />

Best GUI designer for eclipse?

Here is a quite good but old comparison http://wiki.computerwoche.de/doku.php/programmierung/gui-builder_fuer_eclipse Window Builder Pro is now free at Google Web Toolkit

Getting the IP address of the current machine using Java

firstly import the class

import java.net.InetAddress;

in class

  InetAddress iAddress = InetAddress.getLocalHost();
  String currentIp = iAddress.getHostAddress();
  System.out.println("Current IP address : " +currentIp); //gives only host address

Strip / trim all strings of a dataframe

If you really want to use regex, then

>>> df.replace('(^\s+|\s+$)', '', regex=True, inplace=True)
>>> df
   0   1
0  a  10
1  c   5

But it should be faster to do it like this:

>>> df[0] = df[0].str.strip()

How to use comparison and ' if not' in python?

There are two ways. In case of doubt, you can always just try it. If it does not work, you can add extra braces to make sure, like that:

if not ((u0 <= u) and (u < u0+step)):

ignoring any 'bin' directory on a git project

[Bb]in will solve the problem, but... Here a more extensive list of things you should ignore (sample list by GitExtension):

#ignore thumbnails created by windows
Thumbs.db
#Ignore files build by Visual Studio
*.user
*.aps
*.pch
*.vspscc
*_i.c
*_p.c
*.ncb
*.suo
*.bak
*.cache
*.ilk
*.log
[Bb]in
[Dd]ebug*/
*.sbr
obj/
[Rr]elease*/
_ReSharper*/

Sending HTTP Post request with SOAP action using org.apache.http

This is a full working example :

import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpPost; 
import org.apache.http.entity.StringEntity;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.util.EntityUtils;

public void callWebService(String soapAction, String soapEnvBody)  throws IOException {
    // Create a StringEntity for the SOAP XML.
    String body ="<?xml version=\"1.0\" encoding=\"UTF-8\"?><SOAP-ENV:Envelope xmlns:SOAP-ENV=\"http://schemas.xmlsoap.org/soap/envelope/\" xmlns:ns1=\"http://example.com/v1.0/Records\" xmlns:xsd=\"http://www.w3.org/2001/XMLSchema\" xmlns:xsi=\"http://www.w3.org/2001/XMLSchema-instance\" xmlns:SOAP-ENC=\"http://schemas.xmlsoap.org/soap/encoding/\" SOAP-ENV:encodingStyle=\"http://schemas.xmlsoap.org/soap/encoding/\"><SOAP-ENV:Body>"+soapEnvBody+"</SOAP-ENV:Body></SOAP-ENV:Envelope>";
    StringEntity stringEntity = new StringEntity(body, "UTF-8");
    stringEntity.setChunked(true);

    // Request parameters and other properties.
    HttpPost httpPost = new HttpPost("http://example.com?soapservice");
    httpPost.setEntity(stringEntity);
    httpPost.addHeader("Accept", "text/xml");
    httpPost.addHeader("SOAPAction", soapAction);

    // Execute and get the response.
    HttpClient httpClient = new DefaultHttpClient();
    HttpResponse response = httpClient.execute(httpPost);
    HttpEntity entity = response.getEntity();

    String strResponse = null;
    if (entity != null) {
        strResponse = EntityUtils.toString(entity);
    }
}

Remove characters from NSString?

You can try this

- (NSString *)stripRemoveSpaceFrom:(NSString *)str {
    while ([str rangeOfString:@"  "].location != NSNotFound) {
        str = [str stringByReplacingOccurrencesOfString:@" " withString:@""];
    }
    return str;
}

Hope this will help you out.

CSS background image to fit width, height should auto-scale in proportion

body{
    background-image: url(../url/imageName.jpg);
    background-attachment: fixed;
    background-size: auto 100%;
    background-position: center;
}

Java converting int to hex and back again

Java's parseInt method is actally a bunch of code eating "false" hex : if you want to translate -32768, you should convert the absolute value into hex, then prepend the string with '-'.

There is a sample of Integer.java file :

public static int parseInt(String s, int radix)

The description is quite explicit :

* Parses the string argument as a signed integer in the radix 
* specified by the second argument. The characters in the string 
...
...
* parseInt("0", 10) returns 0
* parseInt("473", 10) returns 473
* parseInt("-0", 10) returns 0
* parseInt("-FF", 16) returns -255

Where is Ubuntu storing installed programs?

to find the program you want you can run this command at terminal:

find / usr-name "your_program"

How to list all properties of a PowerShell object

Try this:

Get-WmiObject -Class "Win32_computersystem" | Format-List *
Get-WmiObject -Class "Win32_computersystem" | Format-List -Property *

For certain objects, PowerShell provides a set of formatting instructions that can affect either the table or list formats. These are usually meant to limit the display of reams of properties down to just the essential properties. However there are times when you really want to see everything. In those cases Format-List * will show all the properties. Note that in the case where you're trying to view a PowerShell error record, you need to use "Format-List * -Force" to truly see all the error information, for example,

$error[0] | Format-List * -force

Note that the wildcard can be used like a traditional wilcard this:

Get-WmiObject -Class "Win32_computersystem" | Format-List M*

How to hide first section header in UITableView (grouped style)

Update[9/19/17]: Old answer doesn't work for me anymore in iOS 11. Thanks Apple. The following did:

self.tableView.sectionHeaderHeight = UITableViewAutomaticDimension;
self.tableView.estimatedSectionHeaderHeight = 20.0f;
self.tableView.contentInset = UIEdgeInsetsMake(-18.0, 0.0f, 0.0f, 0.0);

Previous Answer:

As posted in the comments by Chris Ostomo the following worked for me:

- (CGFloat)tableView:(UITableView *)tableView heightForHeaderInSection:(NSInteger)section
{
    return CGFLOAT_MIN; // to get rid of empty section header
}

What is the newline character in the C language: \r or \n?

'\r' = carriage return and '\n' = line feed.

In fact, there are some different behaviors when you use them in different OSes. On Unix it is '\n', but it is '\r''\n' on Windows.

Removing spaces from string

When I am reading numbers from contact book, then it doesn't worked I used

number=number.replaceAll("\\s+", "");

It worked and for url you may use

url=url.replaceAll(" ", "%20");

Playing .mp3 and .wav in Java?

Use this library: import sun.audio.*;

public void Sound(String Path){
    try{
        InputStream in = new FileInputStream(new File(Path));
        AudioStream audios = new AudioStream(in);
        AudioPlayer.player.start(audios);
    }
    catch(Exception e){}
}

Insert results of a stored procedure into a temporary table

EXEC sp_serveroption 'YOURSERVERNAME', 'DATA ACCESS', TRUE

SELECT  *
INTO    #tmpTable
FROM    OPENQUERY(YOURSERVERNAME, 'EXEC db.schema.sproc 1')

Append an array to another array in JavaScript

If you want to modify the original array instead of returning a new array, use .push()...

array1.push.apply(array1, array2);
array1.push.apply(array1, array3);

I used .apply to push the individual members of arrays 2 and 3 at once.

or...

array1.push.apply(array1, array2.concat(array3));

To deal with large arrays, you can do this in batches.

for (var n = 0, to_add = array2.concat(array3); n < to_add.length; n+=300) {
    array1.push.apply(array1, to_add.slice(n, n+300));
}

If you do this a lot, create a method or function to handle it.

var push_apply = Function.apply.bind([].push);
var slice_call = Function.call.bind([].slice);

Object.defineProperty(Array.prototype, "pushArrayMembers", {
    value: function() {
        for (var i = 0; i < arguments.length; i++) {
            var to_add = arguments[i];
            for (var n = 0; n < to_add.length; n+=300) {
                push_apply(this, slice_call(to_add, n, n+300));
            }
        }
    }
});

and use it like this:

array1.pushArrayMembers(array2, array3);

_x000D_
_x000D_
var push_apply = Function.apply.bind([].push);_x000D_
var slice_call = Function.call.bind([].slice);_x000D_
_x000D_
Object.defineProperty(Array.prototype, "pushArrayMembers", {_x000D_
    value: function() {_x000D_
        for (var i = 0; i < arguments.length; i++) {_x000D_
            var to_add = arguments[i];_x000D_
            for (var n = 0; n < to_add.length; n+=300) {_x000D_
                push_apply(this, slice_call(to_add, n, n+300));_x000D_
            }_x000D_
        }_x000D_
    }_x000D_
});_x000D_
_x000D_
var array1 = ['a','b','c'];_x000D_
var array2 = ['d','e','f'];_x000D_
var array3 = ['g','h','i'];_x000D_
_x000D_
array1.pushArrayMembers(array2, array3);_x000D_
_x000D_
document.body.textContent = JSON.stringify(array1, null, 4);
_x000D_
_x000D_
_x000D_

How to use NULL or empty string in SQL

my best solution :

 WHERE  
 COALESCE(char_length(fieldValue), 0) = 0

COALESCE returns the first non-null expr in the expression list().

if the fieldValue is null or empty string then: we will return the second element then 0.

so 0 is equal to 0 then this fieldValue is a null or empty string.

in python for exemple:

def coalesce(fieldValue):
    if fieldValue in (null,''):
        return 0

good luck

Alter MySQL table to add comments on columns

You can use MODIFY COLUMN to do this. Just do...

ALTER TABLE YourTable
MODIFY COLUMN your_column
your_previous_column_definition COMMENT "Your new comment"

substituting:

  • YourTable with the name of your table
  • your_column with the name of your comment
  • your_previous_column_definition with the column's column_definition, which I recommend getting via a SHOW CREATE TABLE YourTable command and copying verbatim to avoid any traps.*
  • Your new comment with the column comment you want.

For example...

mysql> CREATE TABLE `Example` (
    ->   `id` int(10) unsigned NOT NULL AUTO_INCREMENT,
    ->   `some_col` varchar(255) DEFAULT NULL,
    ->   PRIMARY KEY (`id`)
    -> );
Query OK, 0 rows affected (0.18 sec)

mysql> ALTER TABLE Example
    -> MODIFY COLUMN `id`
    -> int(10) unsigned NOT NULL AUTO_INCREMENT COMMENT 'Look, I''m a comment!';
Query OK, 0 rows affected (0.07 sec)
Records: 0  Duplicates: 0  Warnings: 0

mysql> SHOW CREATE TABLE Example;
+---------+---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| Table   | Create Table                                                                                                                                                                                                  |
+---------+---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| Example | CREATE TABLE `Example` (
  `id` int(10) unsigned NOT NULL AUTO_INCREMENT COMMENT 'Look, I''m a comment!',
  `some_col` varchar(255) DEFAULT NULL,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=latin1 |
+---------+---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
1 row in set (0.00 sec)

* Whenever you use MODIFY or CHANGE clauses in an ALTER TABLE statement, I suggest you copy the column definition from the output of a SHOW CREATE TABLE statement. This protects you from accidentally losing an important part of your column definition by not realising that you need to include it in your MODIFY or CHANGE clause. For example, if you MODIFY an AUTO_INCREMENT column, you need to explicitly specify the AUTO_INCREMENT modifier again in the MODIFY clause, or the column will cease to be an AUTO_INCREMENT column. Similarly, if the column is defined as NOT NULL or has a DEFAULT value, these details need to be included when doing a MODIFY or CHANGE on the column or they will be lost.

Java: How to check if object is null?

I use this approach:

if (null == drawable) {
  //do stuff
} else {
  //other things
}

This way I find improves the readability of the line - as I read quickly through a source file I can see it's a null check.

With regards to why you can't call .equals() on an object which may be null; if the object reference you have (namely 'drawable') is in fact null, it doesn't point to an object on the heap. This means there's no object on the heap on which the call to equals() can succeed.

Best of luck!

How can I capture the result of var_dump to a string?

Use output buffering:

<?php
ob_start();
var_dump($someVar);
$result = ob_get_clean();
?>

Why am I getting "(304) Not Modified" error on some links when using HttpWebRequest?

First, this is not an error. The 3xx denotes a redirection. The real errors are 4xx (client error) and 5xx (server error).

If a client gets a 304 Not Modified, then it's the client's responsibility to display the resouce in question from its own cache. In general, the proxy shouldn't worry about this. It's just the messenger.

How to implement drop down list in flutter?

you have to take this into account (from DropdownButton docs):

"The items must have distinct values and if value isn't null it must be among them."

So basically you have this list of strings

List<String> _locations = ['A', 'B', 'C', 'D'];

And your value in Dropdown value property is initialised like this:

String _selectedLocation = 'Please choose a location';

Just try with this list:

List<String> _locations = ['Please choose a location', 'A', 'B', 'C', 'D'];

That should work :)

Also check out the "hint" property if you don't want to add a String like that (out of the list context), you could go with something like this:

DropdownButton<int>(
          items: locations.map((String val) {
                   return new DropdownMenuItem<String>(
                        value: val,
                        child: new Text(val),
                         );
                    }).toList(),
          hint: Text("Please choose a location"),
          onChanged: (newVal) {
                  _selectedLocation = newVal;
                  this.setState(() {});
                  });

Comparing two integer arrays in Java

Even though there is something easy like .equals, I'd like to point out TWO mistakes you made in your code. The first: when you go through the arrays, you say b is true or false. Then you start again to check, because of the for-loop. But each time you are giving b a value. So, no matter what happens, the value b gets set to is always the value of the LAST for-loop. Next time, set boolean b = true, if equal = true, do nothing, if equal = false, b=false.

Secondly, you are now checking each value in array1 with each value in array2. If I understand correctly, you only need to check the values at the same location in the array, meaning you should have deleted the second for-loop and check like this: if (array2[i] == array1[i]). Then your code should function as well.

Your code would work like this:

public static void compareArrays(int[] array1, int[] array2) {
    boolean b = true;
    for (int i = 0; i < array2.length; i++) {
        if (array2[i] == array1[i]) {
            System.out.println("true");
        } else {
            b = false;
            System.out.println("False");
        }
    } 
    return b;

}

But as said by other, easier would be: Arrays.equals(ary1,ary2);

scroll up and down a div on button click using jquery

For the go up, you just need to use scrollTop instead of scrollBottom:

$("#upClick").on("click", function () {
    scrolled = scrolled - 300;
    $(".cover").stop().animate({
        scrollTop: scrolled
    });
});

Also, use the .stop() method to stop the currently-running animation on the cover div. When .stop() is called on an element, the currently-running animation (if any) is immediately stopped.

FIDDLE DEMO

MySQL: @variable vs. variable. What's the difference?

@variable is very useful if calling stored procedures from an application written in Java , Python etc. There are ocassions where variable values are created in the first call and needed in functions of subsequent calls.

Side-note on PL/SQL (Oracle)

The advantage can be seen in Oracle PL/SQL where these variables have 3 different scopes:

  • Function variable for which the scope ends when function exits.
  • Package body variables defined at the top of package and outside all functions whose scope is the session and visibility is package.
  • Package variable whose variable is session and visibility is global.

My Experience in PL/SQL

I have developed an architecture in which the complete code is written in PL/SQL. These are called from a middle-ware written in Java. There are two types of middle-ware. One to cater calls from a client which is also written in Java. The other other one to cater for calls from a browser. The client facility is implemented 100 percent in JavaScript. A command set is used instead of HTML and JavaScript for writing application in PL/SQL.

I have been looking for the same facility to port the codes written in PL/SQL to another database. The nearest one I have found is Postgres. But all the variables have function scope.

Opinion towards @ in MySQL

I am happy to see that at least this @ facility is there in MySQL. I don't think Oracle will build same facility available in PL/SQL to MySQL stored procedures since it may affect the sales of Oracle database.

How can I call the 'base implementation' of an overridden virtual method?

You can't, and you shouldn't. That's what polymorphism is for, so that each object has its own way of doing some "base" things.

Changing file extension in Python

An elegant way using pathlib.Path:

from pathlib import Path
p = Path('mysequence.fasta')
p.rename(p.with_suffix('.aln'))

Call another rest api from my server in Spring-Boot

Create Bean for Rest Template to auto wiring the Rest Template object.

@SpringBootApplication
public class ChatAppApplication {

    @Bean
    public RestTemplate getRestTemplate(){
        return new RestTemplate();
    }

    public static void main(String[] args) {
        SpringApplication.run(ChatAppApplication.class, args);
    }

}

Consume the GET/POST API by using RestTemplate - exchange() method. Below is for the post api which is defined in the controller.

@RequestMapping(value = "/postdata",method = RequestMethod.POST)
    public String PostData(){

       return "{\n" +
               "   \"value\":\"4\",\n" +
               "   \"name\":\"David\"\n" +
               "}";
    }

    @RequestMapping(value = "/post")
    public String getPostResponse(){
        HttpHeaders headers=new HttpHeaders();
        headers.setAccept(Arrays.asList(MediaType.APPLICATION_JSON));
        HttpEntity<String> entity=new HttpEntity<String>(headers);
        return restTemplate.exchange("http://localhost:8080/postdata",HttpMethod.POST,entity,String.class).getBody();
    }

Refer this tutorial[1]

[1] https://www.tutorialspoint.com/spring_boot/spring_boot_rest_template.htm

add an element to int [] array in java

The length of an array is immutable in java. This means you can't change the size of an array once you have created it. If you initialised it with 2 elements, its length is 2. You can however use a different collection.

List<Integer> myList = new ArrayList<Integer>();
myList.add(5);
myList.add(7);

And with a wrapper method

public void addMember(Integer x) {
    myList.add(x);
};

Creating Duplicate Table From Existing Table

Use this query to create the new table with the values from existing table

CREATE TABLE New_Table_name AS SELECT * FROM Existing_table_Name; 

Now you can get all the values from existing table into newly created table.

I am getting Failed to load resource: net::ERR_BLOCKED_BY_CLIENT with Google chrome

As other people have mentioned, this issue is common when using adblock or similar extensions.

The source of my issues was my Privacy Badger extension.

Why use def main()?

Without the main sentinel, the code would be executed even if the script were imported as a module.

Change the name of a key in dictionary

This will lowercase all your dict keys. Even if you have nested dict or lists. You can do something similar to apply other transformations.

def lowercase_keys(obj):
  if isinstance(obj, dict):
    obj = {key.lower(): value for key, value in obj.items()}
    for key, value in obj.items():         
      if isinstance(value, list):
        for idx, item in enumerate(value):
          value[idx] = lowercase_keys(item)
      obj[key] = lowercase_keys(value)
  return obj 
json_str = {"FOO": "BAR", "BAR": 123, "EMB_LIST": [{"FOO": "bar", "Bar": 123}, {"FOO": "bar", "Bar": 123}], "EMB_DICT": {"FOO": "BAR", "BAR": 123, "EMB_LIST": [{"FOO": "bar", "Bar": 123}, {"FOO": "bar", "Bar": 123}]}}

lowercase_keys(json_str)


Out[0]: {'foo': 'BAR',
 'bar': 123,
 'emb_list': [{'foo': 'bar', 'bar': 123}, {'foo': 'bar', 'bar': 123}],
 'emb_dict': {'foo': 'BAR',
  'bar': 123,
  'emb_list': [{'foo': 'bar', 'bar': 123}, {'foo': 'bar', 'bar': 123}]}}

How do I install Keras and Theano in Anaconda Python on Windows?

It is my solution for the same problem

  • Install TDM GCC x64.
  • Install Anaconda x64.
  • Open the Anaconda prompt
  • Run conda update conda
  • Run conda update --all
  • Run conda install mingw libpython
  • Install the latest version of Theano, pip install git+git://github.com/Theano/Theano.git
  • Run pip install git+git://github.com/fchollet/keras.git

How to dump only specific tables from MySQL?

If you're in local machine then use this command

/usr/local/mysql/bin/mysqldump -h127.0.0.1 --port = 3306 -u [username] -p [password] --databases [db_name] --tables [tablename] > /to/path/tablename.sql;

For remote machine, use below one

/usr/local/mysql/bin/mysqldump -h [remoteip] --port = 3306 -u [username] -p [password] --databases [db_name] --tables [tablename] > /to/path/tablename.sql;

Difference between an API and SDK

API is like the building blocks of some puzzling game that a child plays with to join blocks in different shapes and build something they can think of.

SDK, on the other hand, is a proper workshop where all of the development tools are available, rather than pre-shaped building blocks. In a workshop you have the actual tools and you are not limited to blocks, and can therefore make your own blocks, or can create something without any blocks to begin with.

coding without an SDK or API is like making everything from scratch without a workshop - you have to even make your own tools

What exactly is the function of Application.CutCopyMode property in Excel

There is a good explanation at https://stackoverflow.com/a/33833319/903783

The values expected seem to be xlCopy and xlCut according to xlCutCopyMode enumeration (https://msdn.microsoft.com/en-us/VBA/Excel-VBA/articles/xlcutcopymode-enumeration-excel), but the 0 value (this is what False equals to in VBA) seems to be useful to clear Excel data put on the Clipboard.

How do I write a batch script that copies one directory to another, replaces old files?

In your batch file do this

set source=C:\Users\Habib\test
set destination=C:\Users\Habib\testdest\
xcopy %source% %destination% /y

If you want to copy the sub directories including empty directories then do:

xcopy %source% %destination% /E /y

If you only want to copy sub directories and not empty directories then use /s like:

xcopy %source% %destination% /s /y

What is the recommended way to delete a large number of items from DynamoDB?

According to the DynamoDB documentation you could just delete the full table.

See below:

"Deleting an entire table is significantly more efficient than removing items one-by-one, which essentially doubles the write throughput as you do as many delete operations as put operations"

If you wish to delete only a subset of your data, then you could make separate tables for each month, year or similar. This way you could remove "last month" and keep the rest of your data intact.

This is how you delete a table in Java using the AWS SDK:

DeleteTableRequest deleteTableRequest = new DeleteTableRequest()
  .withTableName(tableName);
DeleteTableResult result = client.deleteTable(deleteTableRequest);

Why this line xmlns:android="http://schemas.android.com/apk/res/android" must be the first in the layout xml file?

xmlns:android

Defines the Android namespace. This attribute should always be set to "http://schemas.android.com/apk/res/android".

refer https://developer.android.com/guide/topics/manifest/manifest-element#nspace

Find the index of a char in string?

Contanis occur if using the method of the present letter, and store the corresponding number using the IndexOf method, see example below.

    Private Sub Button1_Click(sender As System.Object, e As System.EventArgs) Handles Button1.Click
    Dim myString As String = "abcdef"
    Dim numberString As String = String.Empty

    If myString.Contains("d") Then
        numberString = myString.IndexOf("d")
    End If
End Sub

Another sample with TextBox

  Private Sub Button1_Click(sender As System.Object, e As System.EventArgs) Handles Button1.Click
    Dim myString As String = "abcdef"
    Dim numberString As String = String.Empty

    If myString.Contains(me.TextBox1.Text) Then
        numberString = myString.IndexOf(Me.TextBox1.Text)
    End If
End Sub

Regards

Order by in Inner Join

You have to sort it if you want the data to come back a certain way. When you say you are expecting "Mohit" to be the first row, I am assuming you say that because "Mohit" is the first row in the [One] table. However, when SQL Server joins tables, it doesn't necessarily join in the order you think.

If you want the first row from [One] to be returned, then try sorting by [One].[ID]. Alternatively, you can order by any other column.

jQuery or CSS selector to select all IDs that start with some string

You can use meta characters like * (http://api.jquery.com/category/selectors/). So I think you just can use $('#player_*').

In your case you could also try the "Attribute starts with" selector: http://api.jquery.com/attribute-starts-with-selector/: $('div[id^="player_"]')

Alternative for frames in html5 using iframes

HTML 5 does support iframes. There were a few interesting attributes added like "sandbox" and "srcdoc".

http://www.w3schools.com/html5/tag_iframe.asp

or you can use

<object data="framed.html" type="text/html"><p>This is the fallback code!</p></object>

How to display UTF-8 characters in phpMyAdmin?

phpmyadmin doesn't follow the MySQL connection because it defines its proper collation in phpmyadmin config file.

So if we don't want or if we can't access server parameters, we should just force it to send results in a different format (encoding) compatible with client i.e. phpmyadmin

for example if both the MySQL connection collation and the MySQL charset are utf8 but phpmyadmin is ISO, we should just add this one before any select query sent to the MYSQL via phpmyadmin :

SET SESSION CHARACTER_SET_RESULTS =latin1;

How to create EditText with cross(x) button at end of it?

Use

android:drawableRight="@android:drawable/ic_input_delete"

SQL Server AS statement aliased column within WHERE statement

I am not sure why you cannot use "lat" but, if you must you can rename the columns in a derived table.

select latitude from (SELECT lat AS latitude FROM poi_table) p where latitude < 500

Remove duplicates from a List<T> in C#

Simply initialize a HashSet with a List of the same type:

var noDupes = new HashSet<T>(withDupes);

Or, if you want a List returned:

var noDupsList = new HashSet<T>(withDupes).ToList();

How much overhead does SSL impose?

Order of magnitude: zero.

In other words, you won't see your throughput cut in half, or anything like it, when you add TLS. Answers to the "duplicate" question focus heavily on application performance, and how that compares to SSL overhead. This question specifically excludes application processing, and seeks to compare non-SSL to SSL only. While it makes sense to take a global view of performance when optimizing, that is not what this question is asking.

The main overhead of SSL is the handshake. That's where the expensive asymmetric cryptography happens. After negotiation, relatively efficient symmetric ciphers are used. That's why it can be very helpful to enable SSL sessions for your HTTPS service, where many connections are made. For a long-lived connection, this "end-effect" isn't as significant, and sessions aren't as useful.


Here's an interesting anecdote. When Google switched Gmail to use HTTPS, no additional resources were required; no network hardware, no new hosts. It only increased CPU load by about 1%.

How to stop tracking and ignore changes to a file in Git?

If you do git update-index --assume-unchanged file.csproj, git won't check file.csproj for changes automatically: that will stop them coming up in git status whenever you change them. So you can mark all your .csproj files this way- although you'll have to manually mark any new ones that the upstream repo sends you. (If you have them in your .gitignore or .git/info/exclude, then ones you create will be ignored)

I'm not entirely sure what .csproj files are... if they're something along the lines of IDE configurations (similar to Eclipse's .eclipse and .classpath files) then I'd suggest they should simply never be source-controlled at all. On the other hand, if they're part of the build system (like Makefiles) then clearly they should--- and a way to pick up optional local changes (e.g. from a local.csproj a la config.mk) would be useful: divide the build up into global parts and local overrides.

Stop node.js program from command line

To end the program, you should be using Ctrl + C. If you do that, it sends SIGINT, which allows the program to end gracefully, unbinding from any ports it is listening on.

See also: https://superuser.com/a/262948/48624

Is there a way to get element by XPath using JavaScript in Selenium WebDriver?

For something like $x from chrome command line api (to select multiple elements) try:

var xpath = function(xpathToExecute){
  var result = [];
  var nodesSnapshot = document.evaluate(xpathToExecute, document, null, XPathResult.ORDERED_NODE_SNAPSHOT_TYPE, null );
  for ( var i=0 ; i < nodesSnapshot.snapshotLength; i++ ){
    result.push( nodesSnapshot.snapshotItem(i) );
  }
  return result;
}

This MDN overview helped: https://developer.mozilla.org/en-US/docs/Introduction_to_using_XPath_in_JavaScript

php variable in html no other way than: <?php echo $var; ?>

There are plenty of templating systems that offer more compact syntax for your views. Smarty is venerable and popular. This article lists 10 others.

What do we mean by Byte array?

I assume you know what a byte is. A byte array is simply an area of memory containing a group of contiguous (side by side) bytes, such that it makes sense to talk about them in order: the first byte, the second byte etc..

Just as bytes can encode different types and ranges of data (numbers from 0 to 255, numbers from -128 to 127, single characters using ASCII e.g. 'a' or '%', CPU op-codes), each byte in a byte array may be any of these things, or contribute to some multi-byte values such as numbers with larger range (e.g. 16-bit unsigned int from 0..65535), international character sets, textual strings ("hello"), or part/all of a compiled computer programs.

The crucial thing about a byte array is that it gives indexed (fast), precise, raw access to each 8-bit value being stored in that part of memory, and you can operate on those bytes to control every single bit. The bad thing is the computer just treats every entry as an independent 8-bit number - which may be what your program is dealing with, or you may prefer some powerful data-type such as a string that keeps track of its own length and grows as necessary, or a floating point number that lets you store say 3.14 without thinking about the bit-wise representation. As a data type, it is inefficient to insert or remove data near the start of a long array, as all the subsequent elements need to be shuffled to make or fill the gap created/required.

Wait for shell command to complete

This is what I use to have VB wait for process to complete before continuing. I did not write this and do not take credit.

It was offered in some other open forum and works very well for me:

The following declarations are needed for the RunShell subroutine:

Option Explicit

Private Declare Function OpenProcess Lib "kernel32" (ByVal dwDesiredAccess As Long, ByVal bInheritHandle As Long, ByVal dwProcessId As Long) As Long

Private Declare Function GetExitCodeProcess Lib "kernel32" (ByVal hProcess As Long, lpExitCode As Long) As Long

Private Declare Function CloseHandle Lib "kernel32" (ByVal hObject As Long) As Long

Private Const PROCESS_QUERY_INFORMATION = &H400

Private Const STATUS_PENDING = &H103&

'then in your subroutine where you need to shell:

RunShell (path and filename or command, as quoted text)

Class JavaLaunchHelper is implemented in two places

You can find all the details here:

  • IDEA-170117 "objc: Class JavaLaunchHelper is implemented in both ..." warning in Run consoles

It's the old bug in Java on Mac that got triggered by the Java Agent being used by the IDE when starting the app. This message is harmless and is safe to ignore. Oracle developer's comment:

The message is benign, there is no negative impact from this problem since both copies of that class are identical (compiled from the exact same source). It is purely a cosmetic issue.

The problem is fixed in Java 9 and in Java 8 update 152.

If it annoys you or affects your apps in any way (it shouldn't), the workaround for IntelliJ IDEA is to disable idea_rt launcher agent by adding idea.no.launcher=true into idea.properties (Help | Edit Custom Properties...). The workaround will take effect on the next restart of the IDE.

I don't recommend disabling IntelliJ IDEA launcher agent, though. It's used for such features as graceful shutdown (Exit button), thread dumps, workarounds a problem with too long command line exceeding OS limits, etc. Losing these features just for the sake of hiding the harmless message is probably not worth it, but it's up to you.

Is it possible to apply CSS to half of a character?

Another CSS-only solution (though data-attribute is needed if you don't want to write letter-specific CSS). This one works more across the board (Tested IE 9/10, Chrome latest & FF latest)

_x000D_
_x000D_
span {_x000D_
  position: relative;_x000D_
  color: rgba(50,50,200,0.5);_x000D_
}_x000D_
_x000D_
span:before {_x000D_
  content: attr(data-char);_x000D_
  position: absolute;_x000D_
  width: 50%;_x000D_
  overflow: hidden;_x000D_
  color: rgb(50,50,200);_x000D_
}
_x000D_
<span data-char="X">X</span>
_x000D_
_x000D_
_x000D_

When to use %r instead of %s in Python?

%r shows with quotes:

It will be like:

I said: 'There are 10 types of people.'.

If you had used %s it would have been:

I said: There are 10 types of people..