Programs & Examples On #Ulong

Creating a List of Lists in C#

A quick example:

List<List<string>> myList = new List<List<string>>();
myList.Add(new List<string> { "a", "b" });
myList.Add(new List<string> { "c", "d", "e" });
myList.Add(new List<string> { "qwerty", "asdf", "zxcv" });
myList.Add(new List<string> { "a", "b" });

// To iterate over it.
foreach (List<string> subList in myList)
{
    foreach (string item in subList)
    {
        Console.WriteLine(item);
    }
}

Is that what you were looking for? Or are you trying to create a new class that extends List<T> that has a member that is a `List'?

Converting a JToken (or string) to a given Type

There is a ToObject method now.

var obj = jsonObject["date_joined"];
var result = obj.ToObject<DateTime>();

It also works with any complex type, and obey to JsonPropertyAttribute rules

var result = obj.ToObject<MyClass>();

public class MyClass 
{ 
    [JsonProperty("date_field")]
    public DateTime MyDate {get;set;}
}

In PowerShell, how can I test if a variable holds a numeric value?

-is and -as operators requires a type you can compare against. If you're not sure what the type might be, try to evaluate the content (partial type list):

(Invoke-Expression '1.5').GetType().Name -match 'byte|short|int32|long|sbyte|ushort|uint32|ulong|float|double|decimal'

Good or bad, it can work against hex values as well (Invoke-Expression '0xA' ...)

What is the difference between “int” and “uint” / “long” and “ulong”?

The difference is that the uint and ulong are unsigned data types, meaning the range is different: They do not accept negative values:

int range: -2,147,483,648 to 2,147,483,647
uint range: 0 to 4,294,967,295

long range: –9,223,372,036,854,775,808 to 9,223,372,036,854,775,807
ulong range: 0 to 18,446,744,073,709,551,615

Determining 32 vs 64 bit in C++

Try this:
#ifdef _WIN64
// 64 bit code
#elif _WIN32
// 32 bit code
#else
   if(sizeof(void*)==4)

       // 32 bit code
   else 

       // 64 bit code   
#endif

Default value to a parameter while passing by reference in C++

You can do it for a const reference, but not for a non-const one. This is because C++ does not allow a temporary (the default value in this case) to be bound to non-const reference.

One way round this would be to use an actual instance as the default:

static int AVAL = 1;

void f( int & x = AVAL ) {
   // stuff
} 

int main() {
     f();       // equivalent to f(AVAL);
}

but this is of very limited practical use.

How to check if a number is a power of 2

In C, I tested the i && !(i & (i - 1) trick and compared it with __builtin_popcount(i), using gcc on Linux, with the -mpopcnt flag to be sure to use the CPU's POPCNT instruction. My test program counted the # of integers between 0 and 2^31 that were a power of two.

At first I thought that i && !(i & (i - 1) was 10% faster, even though I verified that POPCNT was used in the disassembly where I used__builtin_popcount.

However, I realized that I had included an if statement, and branch prediction was probably doing better on the bit twiddling version. I removed the if and POPCNT ended up faster, as expected.

Results:

Intel(R) Core(TM) i7-4771 CPU max 3.90GHz

Timing (i & !(i & (i - 1))) trick
30

real    0m13.804s
user    0m13.799s
sys     0m0.000s

Timing POPCNT
30

real    0m11.916s
user    0m11.916s
sys     0m0.000s

AMD Ryzen Threadripper 2950X 16-Core Processor max 3.50GHz

Timing (i && !(i & (i - 1))) trick
30

real    0m13.675s
user    0m13.673s
sys 0m0.000s

Timing POPCNT
30

real    0m13.156s
user    0m13.153s
sys 0m0.000s

Note that here the Intel CPU seems slightly slower than AMD with the bit twiddling, but has a much faster POPCNT; the AMD POPCNT doesn't provide as much of a boost.

popcnt_test.c:

#include "stdio.h"

// Count # of integers that are powers of 2 up to 2^31;
int main() {
  int n;
  for (int z = 0; z < 20; z++){
      n = 0;
      for (unsigned long i = 0; i < 1<<30; i++) {
       #ifdef USE_POPCNT
        n += (__builtin_popcount(i)==1); // Was: if (__builtin_popcount(i) == 1) n++;
       #else
        n += (i && !(i & (i - 1)));  // Was: if (i && !(i & (i - 1))) n++;
       #endif
      }
  }

  printf("%d\n", n);
  return 0;
}

Run tests:

gcc popcnt_test.c -O3 -o test.exe
gcc popcnt_test.c -O3 -DUSE_POPCNT -mpopcnt -o test-popcnt.exe

echo "Timing (i && !(i & (i - 1))) trick"
time ./test.exe

echo
echo "Timing POPCNT"
time ./test-opt.exe

PHP header(Location: ...): Force URL change in address bar

Are you sure the page you are redirecting too doesn't have a redirection within that if no session data is found? That could be your problem

Also yes always add whitespace like @Peter O suggested.

What are the time complexities of various data structures?

Arrays

  • Set, Check element at a particular index: O(1)
  • Searching: O(n) if array is unsorted and O(log n) if array is sorted and something like a binary search is used,
  • As pointed out by Aivean, there is no Delete operation available on Arrays. We can symbolically delete an element by setting it to some specific value, e.g. -1, 0, etc. depending on our requirements
  • Similarly, Insert for arrays is basically Set as mentioned in the beginning

ArrayList:

  • Add: Amortized O(1)
  • Remove: O(n)
  • Contains: O(n)
  • Size: O(1)

Linked List:

  • Inserting: O(1), if done at the head, O(n) if anywhere else since we have to reach that position by traveseing the linkedlist linearly.
  • Deleting: O(1), if done at the head, O(n) if anywhere else since we have to reach that position by traveseing the linkedlist linearly.
  • Searching: O(n)

Doubly-Linked List:

  • Inserting: O(1), if done at the head or tail, O(n) if anywhere else since we have to reach that position by traveseing the linkedlist linearly.
  • Deleting: O(1), if done at the head or tail, O(n) if anywhere else since we have to reach that position by traveseing the linkedlist linearly.
  • Searching: O(n)

Stack:

  • Push: O(1)
  • Pop: O(1)
  • Top: O(1)
  • Search (Something like lookup, as a special operation): O(n) (I guess so)

Queue/Deque/Circular Queue:

  • Insert: O(1)
  • Remove: O(1)
  • Size: O(1)

Binary Search Tree:

  • Insert, delete and search: Average case: O(log n), Worst Case: O(n)

Red-Black Tree:

  • Insert, delete and search: Average case: O(log n), Worst Case: O(log n)

Heap/PriorityQueue (min/max):

  • Find Min/Find Max: O(1)
  • Insert: O(log n)
  • Delete Min/Delete Max: O(log n)
  • Extract Min/Extract Max: O(log n)
  • Lookup, Delete (if at all provided): O(n), we will have to scan all the elements as they are not ordered like BST

HashMap/Hashtable/HashSet:

  • Insert/Delete: O(1) amortized
  • Re-size/hash: O(n)
  • Contains: O(1)

Method with a bool return

     public bool roomSelected()
    {
        int a = 0;
        foreach (RadioButton rb in GroupBox1.Controls)
        {
            if (rb.Checked == true)
            {
                a = 1;
            }
        }
        if (a == 1)
        {
            return true;
        }
        else
        {
            return false;
        }
    }

this how I solved my problem

What evaluates to True/False in R?

This is documented on ?logical. The pertinent section of which is:

Details:

     ‘TRUE’ and ‘FALSE’ are reserved words denoting logical constants
     in the R language, whereas ‘T’ and ‘F’ are global variables whose
     initial values set to these.  All four are ‘logical(1)’ vectors.

     Logical vectors are coerced to integer vectors in contexts where a
     numerical value is required, with ‘TRUE’ being mapped to ‘1L’,
     ‘FALSE’ to ‘0L’ and ‘NA’ to ‘NA_integer_’.

The second paragraph there explains the behaviour you are seeing, namely 5 == 1L and 5 == 0L respectively, which should both return FALSE, where as 1 == 1L and 0 == 0L should be TRUE for 1 == TRUE and 0 == FALSE respectively. I believe these are not testing what you want them to test; the comparison is on the basis of the numerical representation of TRUE and FALSE in R, i.e. what numeric values they take when coerced to numeric.

However, only TRUE is guaranteed to the be TRUE:

> isTRUE(TRUE)
[1] TRUE
> isTRUE(1)
[1] FALSE
> isTRUE(T)
[1] TRUE
> T <- 2
> isTRUE(T)
[1] FALSE

isTRUE is a wrapper for identical(x, TRUE), and from ?isTRUE we note:

Details:
....

     ‘isTRUE(x)’ is an abbreviation of ‘identical(TRUE, x)’, and so is
     true if and only if ‘x’ is a length-one logical vector whose only
     element is ‘TRUE’ and which has no attributes (not even names).

So by the same virtue, only FALSE is guaranteed to be exactly equal to FALSE.

> identical(F, FALSE)
[1] TRUE
> identical(0, FALSE)
[1] FALSE
> F <- "hello"
> identical(F, FALSE)
[1] FALSE

If this concerns you, always use isTRUE() or identical(x, FALSE) to check for equivalence with TRUE and FALSE respectively. == is not doing what you think it is.

java.lang.IllegalStateException: The specified child already has a parent

It also happens when the view returned by onCreateView() isn't the view that was inflated.

Example:

View rootView = inflater.inflate(R.layout.my_fragment, container, false);

TextView textView = (TextView) rootView.findViewById(R.id.text_view);
textView.setText("Some text.");

return textView;

Fix:

return rootView;

Instead of:

return textView; // or whatever you returned

IF EXISTS in T-SQL

There's no need for "else" in this case:

IF EXISTS(SELECT *  FROM  table1  WHERE Name='John' ) return 1
return 0

CSS Change List Item Background Color with Class

Scenario: I have a navigation menu like this. Note: Link <a> is child of list item <li>. I wanted to change the background of the selected list item and remove the background color of unselected list item.

<nav>
        <ul>
            <li><a href="#">Intro</a></li>
            <li><a href="#">Size</a></li>
            <li><a href="#">Play</a></li>
            <li><a href="#">Food</a></li>
        </ul>
        <div class="clear"></div>

       </nav>

I tried to add a class .active into the list item using jQuery but it was not working

.active
{
    background-color: #480048;
}

$("nav li a").click(function () {
        $(this).parent().addClass("active");
        $(this).parent().siblings().removeClass("active");
    });

Solution: Basically, using .active class changing the background-color of list item does not work. So I changed the css class name from .active to "nav li.active a" so using the same javascript it will add the .active class into the selected list item. Now if the list item <li> has .active class then css will change the background color of the child of that list item <a>.

nav li.active a
{
    background-color: #480048;
}

Using multiple .cpp files in c++ program?

You can simply place a forward declaration of your second() function in your main.cpp above main(). If your second.cpp has more than one function and you want all of it in main(), put all the forward declarations of your functions in second.cpp into a header file and #include it in main.cpp.

Like this-

Second.h:

void second();
int third();
double fourth();

main.cpp:

#include <iostream>
#include "second.h"
int main()
{
    //.....
    return 0;
}

second.cpp:

void second()
{
    //...
}

int third()
{ 
    //...
    return foo;
}

double fourth()
{ 
    //...
    return f;
}

Note that: it is not necessary to #include "second.h" in second.cpp. All your compiler need is forward declarations and your linker will do the job of searching the definitions of those declarations in the other files.

html5 localStorage error with Safari: "QUOTA_EXCEEDED_ERR: DOM Exception 22: An attempt was made to add something to storage that exceeded the quota."

Here's a solution for AngularJS using an IIFE and leveraging the fact that services are singletons.

This results in isLocalStorageAvailable being set immediately when the service is first injected and avoids needlessly running the check every time local storage needs to be accessed.

angular.module('app.auth.services', []).service('Session', ['$log', '$window',
  function Session($log, $window) {
    var isLocalStorageAvailable = (function() {
      try {
        $window.localStorage.world = 'hello';
        delete $window.localStorage.world;
        return true;
      } catch (ex) {
        return false;
      }
    })();

    this.store = function(key, value) {
      if (isLocalStorageAvailable) {
        $window.localStorage[key] = value;
      } else {
        $log.warn('Local Storage is not available');
      }
    };
  }
]);

Convert txt to csv python script

You need to split the line first.

import csv

with open('log.txt', 'r') as in_file:
    stripped = (line.strip() for line in in_file)
    lines = (line.split(",") for line in stripped if line)
    with open('log.csv', 'w') as out_file:
        writer = csv.writer(out_file)
        writer.writerow(('title', 'intro'))
        writer.writerows(lines)

How to convert an entire MySQL database characterset and collation to UTF-8?

To change the character set encoding to UTF-8 follow simple steps in PHPMyAdmin

  1. Select your Database SS

  2. Go To Operations SS

  3. In operations tab, on the bottom collation drop down menu, select you desire encoding i.e(utf8_general_ci), and also check the checkbox (1)change all table collations, (2) Change all tables columns collations. and hit Go.

SS

How to open Atom editor from command line in OS X?

With conemu on windows 10 I couldn't call atom from console even after I added %USERPROFILE%\AppData\Local\atom\bin to PATH in environment variables. I just added

alias atom="C:/Users/me/AppData/local/atom/app-1.12.7/atom"

to my .bashrc file.

Non-resolvable parent POM for Could not find artifact and 'parent.relativePath' points at wrong local POM

I encountered an issue like this using the Maven Release Plugin. Resolving using relative paths (i.e. for the parent pom in the child module ../parent/pom.xml) did not seem to work in this scenario, it keeps looking for the released parent pom in the Nexus repository. Moving the parent pom to the parent folder of the module resolved this.

How to implement zoom effect for image view in android?

Very simple way (Tested) :-

PhotoViewAttacher pAttacher;
pAttacher = new PhotoViewAttacher(Your_Image_View);
pAttacher.update();

Add bellow line in build.gradle :-

compile 'com.commit451:PhotoView:1.2.4'

Why does npm install say I have unmet dependencies?

I fixed the issue by using these command lines

  • $ rm -rf node_modules/
  • $ sudo npm update -g npm
  • $ npm install

It's done!

How to disable Paste (Ctrl+V) with jQuery?

_x000D_
_x000D_
$(document).ready(function(){_x000D_
   $('input').on("cut copy paste",function(e) {_x000D_
      e.preventDefault();_x000D_
   });_x000D_
});
_x000D_
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>_x000D_
<input type="text" />
_x000D_
_x000D_
_x000D_

Nesting CSS classes

Not possible with vanilla CSS. However you can use something like:

Sass makes CSS fun again. Sass is an extension of CSS3, adding nested rules, variables, mixins, selector inheritance, and more. It’s translated to well-formatted, standard CSS using the command line tool or a web-framework plugin.

Or

Rather than constructing long selector names to specify inheritance, in Less you can simply nest selectors inside other selectors. This makes inheritance clear and style sheets shorter.

Example:

#header {
  color: red;
  a {
    font-weight: bold;
    text-decoration: none;
  }
}

How do I convert certain columns of a data frame to become factors?

Given the following sample

myData <- data.frame(A=rep(1:2, 3), B=rep(1:3, 2), Pulse=20:25)  

then

myData$A <-as.factor(myData$A)
myData$B <-as.factor(myData$B)

or you could select your columns altogether and wrap it up nicely:

# select columns
cols <- c("A", "B")
myData[,cols] <- data.frame(apply(myData[cols], 2, as.factor))

levels(myData$A) <- c("long", "short")
levels(myData$B) <- c("1kg", "2kg", "3kg")

To obtain

> myData
      A   B Pulse
1  long 1kg    20
2 short 2kg    21
3  long 3kg    22
4 short 1kg    23
5  long 2kg    24
6 short 3kg    25

Cannot use mkdir in home directory: permission denied (Linux Lubuntu)

you can try writing the command using 'sudo':

sudo mkdir DirName

Linear regression with matplotlib / numpy

This code:

from scipy.stats import linregress

linregress(x,y) #x and y are arrays or lists.

gives out a list with the following:

slope : float
slope of the regression line
intercept : float
intercept of the regression line
r-value : float
correlation coefficient
p-value : float
two-sided p-value for a hypothesis test whose null hypothesis is that the slope is zero
stderr : float
Standard error of the estimate

Source

Converting string to number in javascript/jQuery

You can use parseInt(string, radix) to convert string value to integer like this code below

var votevalue = parseInt($('button').data('votevalue'));
?

DEMO

How do I disable the resizable property of a textarea?

In CSS ...

textarea {
    resize: none;
}

MySQL error 1449: The user specified as a definer does not exist

Solution is just a single line query as below :

grant all on *.* to 'ROOT'@'%' identified by 'PASSWORD' with grant option;

Replace ROOT with your mysql user name. Replace PASSWORD with your mysql password.

Excel VBA Automation Error: The object invoked has disconnected from its clients

I had this same problem in a large Excel 2000 spreadsheet with hundreds of lines of code. My solution was to make the Worksheet active at the beginning of the Class. I.E. ThisWorkbook.Worksheets("WorkSheetName").Activate This was finally discovered when I noticed that if "WorkSheetName" was active when starting the operation (the code) the error didn't occur. Drove me crazy for quite awhile.

How to change an Android app's name?

follow the steps:(let I assuming you have chosen Android view) app>res>values>strings

<string name="app_name">Put your App's new name here</string>

Azure SQL Database "DTU percentage" metric

To check the accurate usage for your services be it is free (as per always free or 12 months free) or Pay-As-You-Go, it is important to monitor the usage so that you know upfront on the cost incurred or when to upgrade your service tier.

To check your free service usage and its limits, Go to search in Portal, search with "Subscription" and click on it. you will see the details of each service that you have used.

In case of free azure from Microsoft, you get to see the cost incurred for each one.

Visit Check usage of free services included with your Azure free account enter image description here

Hope this helps someone!

How do I preserve line breaks when getting text from a textarea?

Here is an idea as you may have multiple newline in a textbox:

 var text=document.getElementById('post-text').value.split('\n');
 var html = text.join('<br />');

This HTML value will preserve newline. Hope this helps.

What is the best way to extract the first word from a string in Java?

You should be doing this

String input = "hello world, this is a line of text";

int i = input.indexOf(' ');
String word = input.substring(0, i);
String rest = input.substring(i);

The above is the fastest way of doing this task.

Auto-center map with multiple markers in Google Maps API v3

To find the exact center of the map you'll need to translate the lat/lon coordinates into pixel coordinates and then find the pixel center and convert that back into lat/lon coordinates.

You might not notice or mind the drift depending how far north or south of the equator you are. You can see the drift by doing map.setCenter(map.getBounds().getCenter()) inside of a setInterval, the drift will slowly disappear as it approaches the equator.

You can use the following to translate between lat/lon and pixel coordinates. The pixel coordinates are based on a plane of the entire world fully zoomed in, but you can then find the center of that and switch it back into lat/lon.

   var HALF_WORLD_CIRCUMFERENCE = 268435456; // in pixels at zoom level 21
   var WORLD_RADIUS = HALF_WORLD_CIRCUMFERENCE / Math.PI;

   function _latToY ( lat ) {
      var sinLat = Math.sin( _toRadians( lat ) );
      return HALF_WORLD_CIRCUMFERENCE - WORLD_RADIUS * Math.log( ( 1 + sinLat ) / ( 1 - sinLat ) ) / 2;
   }

   function _lonToX ( lon ) {
      return HALF_WORLD_CIRCUMFERENCE + WORLD_RADIUS * _toRadians( lon );
   }

   function _xToLon ( x ) {
      return _toDegrees( ( x - HALF_WORLD_CIRCUMFERENCE ) / WORLD_RADIUS );
   }

   function _yToLat ( y ) {
      return _toDegrees( Math.PI / 2 - 2 * Math.atan( Math.exp( ( y - HALF_WORLD_CIRCUMFERENCE ) / WORLD_RADIUS ) ) );
   }

   function _toRadians ( degrees ) {
      return degrees * Math.PI / 180;
   }

   function _toDegrees ( radians ) {
      return radians * 180 / Math.PI;
   }

extra qualification error in C++

Are you putting this line inside the class declaration? In that case you should remove the JSONDeserializer::.

TSQL Pivot without aggregate function

Here is a great way to build dynamic fields for a pivot query:

--summarize values to a tmp table

declare @STR varchar(1000)
SELECT  @STr =  COALESCE(@STr +', ', '') 
+ QUOTENAME(DateRange) 
from (select distinct DateRange, ID from ##pivot)d order by ID

---see the fields generated

print @STr

exec('  .... pivot code ...
pivot (avg(SalesAmt) for DateRange IN (' + @Str +')) AS P
order by Decile')

How to rename JSON key

By using map function you can do that. Please refer below code.

var userDetails = [{
  "_id":"5078c3a803ff4197dc81fbfb",
  "email":"[email protected]",
  "image":"some_image_url",
  "name":"Name 1"
},{
  "_id":"5078c3a803ff4197dc81fbfc",
  "email":"[email protected]",
  "image":"some_image_url",
  "name":"Name 2"
}];

var formattedUserDetails = userDetails.map(({ _id:id, email, image, name }) => ({
  id,
  email,
  image,
  name
}));
console.log(formattedUserDetails);

How to make borders collapse (on a div)?

Use simple negative margin rather than using display table.

Updated in fiddle JS Fiddle

.container { 
    border-style: solid;
    border-color: red;
    border-width: 1px 0 0 1px;
    display: inline-block;
}
.column { 
    float: left; overflow: hidden; 
}
.cell { 
    border: 1px solid red; width: 120px; height: 20px; 
    margin:-1px 0 0 -1px;
}
.clearfix {
    clear:both;
}

How to calculate the number of occurrence of a given character in each row of a column of strings?

I'm sure someone can do better, but this works:

sapply(as.character(q.data$string), function(x, letter = "a"){
  sum(unlist(strsplit(x, split = "")) == letter)
})
greatgreat      magic        not 
     2          1          0 

or in a function:

countLetter <- function(charvec, letter){
  sapply(charvec, function(x, letter){
    sum(unlist(strsplit(x, split = "")) == letter)
  }, letter = letter)
}
countLetter(as.character(q.data$string),"a")

MySQL INSERT INTO ... VALUES and SELECT

just use a subquery right there like:

INSERT INTO table1 VALUES ("A string", 5, (SELECT ...)).

Check date between two other dates spring data jpa

You should take a look the reference documentation. It's well explained.

In your case, I think you cannot use between because you need to pass two parameters

Between - findByStartDateBetween … where x.startDate between ?1 and ?2

In your case take a look to use a combination of LessThan or LessThanEqual with GreaterThan or GreaterThanEqual

  • LessThan/LessThanEqual

LessThan - findByEndLessThan … where x.start< ?1

LessThanEqual findByEndLessThanEqual … where x.start <= ?1

  • GreaterThan/GreaterThanEqual

GreaterThan - findByStartGreaterThan … where x.end> ?1

GreaterThanEqual - findByStartGreaterThanEqual … where x.end>= ?1

You can use the operator And and Or to combine both.

Permutations in JavaScript?

Similar in spirit to the Haskell-style solution by @crl, but working with reduce:

function permutations( base ) {
  if (base.length == 0) return [[]]
  return permutations( base.slice(1) ).reduce( function(acc,perm) {
    return acc.concat( base.map( function(e,pos) {
      var new_perm = perm.slice()
      new_perm.splice(pos,0,base[0])
      return new_perm
    }))
  },[])    
}

For vs. while in C programming?

I noticed some time ago that a For loop typically generates several more machine instructions than a while loop. However, if you look closely at the examples, which mirror my observations, the difference is two or three machine instructions, hardly worth much consideration.

Note, too, that the initializer for a WHILE loop can be eliminated by baking it into the code, e. g.:

static int intStartWith = 100;

The static modifier bakes the initial value into the code, saving (drum roll) one MOV instruction. Of greater significance, marking a variable as static moves it outside the stack frame. Variable alignment permitting, it may also produce slightly smaller code, too, since the MOV instruction and its operands take more room than, for example an integer, Boolean, or character value (either ANSI or Unicode).

However, if variables are aligned on 8 byte boundaries, a common default setting, an int, bool, or TCHAR baked into code costs the same number of bytes as a MOV instruction.

How can I add C++11 support to Code::Blocks compiler?

Use g++ -std=c++11 -o <output_file_name> <file_to_be_compiled>

How to use count and group by at the same select statement

Try the following code:

select ccode, count(empno) 
from company_details 
group by ccode;

UICollectionView - dynamic cell height?

Swift 4.*

I have created a Xib for UICollectionViewCell which seems to be the good approach.

extension ViewController: UICollectionViewDelegateFlowLayout {

    func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
        return size(indexPath: indexPath)
    }

    private func size(for indexPath: IndexPath) -> CGSize {
        // load cell from Xib
        let cell = Bundle.main.loadNibNamed("ACollectionViewCell", owner: self, options: nil)?.first as! ACollectionViewCell

        // configure cell with data in it
        let data = self.data[indexPath.item]
        cell.configure(withData: data)

        cell.setNeedsLayout()
        cell.layoutIfNeeded()

        // width that you want
        let width = collectionView.frame.width
        let height: CGFloat = 0

        let targetSize = CGSize(width: width, height: height)

        // get size with width that you want and automatic height
        let size = cell.contentView.systemLayoutSizeFitting(targetSize, withHorizontalFittingPriority: .defaultHigh, verticalFittingPriority: .fittingSizeLevel)
        // if you want height and width both to be dynamic use below
        // let size = cell.contentView.systemLayoutSizeFitting(UILayoutFittingCompressedSize)

        return size
    }
}

#note: I don't recommend setting image when configuring data in this size determining case. It gave me the distorted/unwanted result. Configuring texts only gave me below result.

enter image description here

PHP 5 disable strict standards error

I didn't see an answer that's clean and suitable for production-ready software, so here it goes:

/*
 * Get current error_reporting value,
 * so that we don't lose preferences set in php.ini and .htaccess
 * and accidently reenable message types disabled in those.
 *
 * If you want to disable e.g. E_STRICT on a global level,
 * use php.ini (or .htaccess for folder-level)
 */
$old_error_reporting = error_reporting();

/*
 * Disable E_STRICT on top of current error_reporting.
 *
 * Note: do NOT use ^ for disabling error message types,
 * as ^ will re-ENABLE the message type if it happens to be disabled already!
 */
error_reporting($old_error_reporting & ~E_STRICT);


// code that should not emit E_STRICT messages goes here


/*
 * Optional, depending on if/what code comes after.
 * Restore old settings.
 */
error_reporting($old_error_reporting);

JAVA - using FOR, WHILE and DO WHILE loops to sum 1 through 100

Your for loop looks good.

A possible while loop to accomplish the same thing:

int sum = 0;
int i = 1;
while (i <= 100) {
    sum += i;
    i++;
}
System.out.println("The sum is " + sum);

A possible do while loop to accomplish the same thing:

int sum = 0;
int i = 1;
do {
    sum += i;
    i++;
} while (i <= 100);
System.out.println("The sum is " + sum);

The difference between the while and the do while is that, with the do while, at least one iteration is sure to occur.

warning: incompatible implicit declaration of built-in function ‘xyz’

Here is some C code that produces the above mentioned error:

int main(int argc, char **argv) {
  exit(1);
}

Compiled like this on Fedora 17 Linux 64 bit with gcc:

el@defiant ~/foo2 $ gcc -o n n2.c                                                               
n2.c: In function ‘main’:
n2.c:2:3: warning: incompatible implicit declaration of built-in 
function ‘exit’ [enabled by default]
el@defiant ~/foo2 $ ./n 
el@defiant ~/foo2 $ 

To make the warning go away, add this declaration to the top of the file:

#include <stdlib.h>

How to trim leading and trailing white spaces of a string?

For trimming your string, Go's "strings" package have TrimSpace(), Trim() function that trims leading and trailing spaces.

Check the documentation for more information.

Node.js spawn child process and get terminal output live

I found myself requiring this functionality often enough that I packaged it into a library called std-pour. It should let you execute a command and view the output in real time. To install simply:

npm install std-pour

Then it's simple enough to execute a command and see the output in realtime:

const { pour } = require('std-pour');
pour('ping', ['8.8.8.8', '-c', '4']).then(code => console.log(`Error Code: ${code}`));

It's promised based so you can chain multiple commands. It's even function signature-compatible with child_process.spawn so it should be a drop in replacement anywhere you're using it.

ASP.NET Core - Swashbuckle not creating swagger.json file

I was running into a similar, but not exactly the same issue with swagger. Hopefully this helps someone else.

I was using a custom document title and was not changing the folder path in the SwaggerEndPoint to match the document title. If you leave the endpoint pointing to swagger/v1/swagger.json it won't find the json file in the swagger UI.

Example:

services.AddSwaggerGen(swagger =>
{
    swagger.SwaggerDoc("AppAdministration", new Info { Title = "App Administration API", Version = "v1.0" });
            
});


app.UseSwaggerUI(c =>
{
    c.SwaggerEndpoint("/swagger/AppAdministration/swagger.json", "App Administration");
});

django no such table:

One way to sync your database to your django models is to delete your database file and run makemigrations and migrate commands again. This will reflect your django models structure to your database from scratch. Although, make sure to backup your database file before deleting in case you need your records.

This solution worked for me since I wasn't much bothered about the data and just wanted my db and models structure to sync up.

Eclipse not recognizing JVM 1.8

Echoing the answer, above, a full install of the JDK (8u121 at this writing) from here - http://www.oracle.com/technetwork/java/javase/downloads/jdk8-downloads-2133151.html - did the trick. Updating via the Mac OS Control Panel did not update the profile variable. Installing via the full installer, did. Then Eclipse was happy.

Convert a date format in PHP

Also another obscure possibility:

$oldDate = '2010-03-20'
$arr = explode('-', $oldDate);
$newDate = $arr[2].'-'.$arr[1].'-'.$arr[0];

I don't know if I would use it but still :)

How to subtract days from a plain Date?

I have created a function for date manipulation. you can add or subtract any number of days, hours, minutes.

function dateManipulation(date, days, hrs, mins, operator) {
   date = new Date(date);
   if (operator == "-") {
      var durationInMs = (((24 * days) * 60) + (hrs * 60) + mins) * 60000;
      var newDate = new Date(date.getTime() - durationInMs);
   } else {
      var durationInMs = (((24 * days) * 60) + (hrs * 60) + mins) * 60000;
      var newDate = new Date(date.getTime() + durationInMs);
   }
   return newDate;
 }

Now, call this function by passing parameters. For example, here is a function call for getting date before 3 days from today.

var today = new Date();
var newDate = dateManipulation(today, 3, 0, 0, "-");

How to remove duplicate values from a multi-dimensional array in PHP

The user comments on the array_unique() documentation have many solutions to this. Here is one of them:

kenrbnsn at rbnsn dot com
27-Sep-2005 12:09

Yet another Array_Unique for multi-demensioned arrays. I've only tested this on two-demensioned arrays, but it could probably be generalized for more, or made to use recursion.

This function uses the serialize, array_unique, and unserialize functions to do the work.


function multi_unique($array) {
    foreach ($array as $k=>$na)
        $new[$k] = serialize($na);
    $uniq = array_unique($new);
    foreach($uniq as $k=>$ser)
        $new1[$k] = unserialize($ser);
    return ($new1);
}

This is from http://ca3.php.net/manual/en/function.array-unique.php#57202.

java.lang.NoSuchMethodError: org.apache.commons.codec.binary.Base64.encodeBase64String() in Java EE application

I faced the same problem with JBoss 4.2.3 GA when deploying my web application. I solved the issue by copying my commons-codec 1.6 jar into C:\jboss-4.2.3.GA\server\default\lib

How to get the caret column (not pixels) position in a textarea, in characters, from the start?

If you don't have to support IE, you can use selectionStart and selectionEnd attributes of textarea.

To get caret position just use selectionStart:

function getCaretPosition(textarea) {
  return textarea.selectionStart
}

To get the strings surrounding the selection, use following code:

function getSurroundingSelection(textarea) {
  return [textarea.value.substring(0, textarea.selectionStart)
         ,textarea.value.substring(textarea.selectionStart, textarea.selectionEnd)
         ,textarea.value.substring(textarea.selectionEnd, textarea.value.length)]
}

Demo on JSFiddle.

See also HTMLTextAreaElement docs.

How to list files in an android directory?

String[] listOfFiles = getActivity().getFilesDir().list();

or

String[] listOfFiles = Environment.getExternalStoragePublicDirectory (Environment.DIRECTORY_DOWNLOADS).list();

Change PictureBox's image to image from my resources?

Ken has the right solution, but you don't want to add the picturebox.Image.Load() member method.

If you do it with a Load and the ImageLocation is not set, it will fail with a "Image Location must be set" exception. If you use the picturebox.Refresh() member method, it works without the exception.

Completed code below:

public void showAnimatedPictureBox(PictureBox thePicture)
{
            thePicture.Image = Properties.Resources.hamster;
            thePicture.Refresh();
            thePicture.Visible = true;
}

It is invoked as: showAnimatedPictureBox( myPictureBox );

My XAML looks like:

    <Window
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:wfi="clr-namespace:System.Windows.Forms.Integration;assembly=WindowsFormsIntegration"
        xmlns:winForms="clr-namespace:System.Windows.Forms;assembly=System.Windows.Forms"
        xmlns:d="http://schemas.microsoft.com/expression/blend/2008" xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" mc:Ignorable="d" x:Class="myApp.MainWindow"
        Title="myApp" Height="679.079" Width="986">

        <StackPanel Width="136" Height="Auto" Background="WhiteSmoke" x:Name="statusPanel">
            <wfi:WindowsFormsHost>
                <winForms:PictureBox x:Name="myPictureBox">
                </winForms:PictureBox>
            </wfi:WindowsFormsHost>
            <Label x:Name="myLabel" Content="myLabel" Margin="10,3,10,5" FontSize="20" FontWeight="Bold" Visibility="Hidden"/>
        </StackPanel>
</Window>

I realize this is an old post, but loading the image directly from a resource is was extremely unclear on Microsoft's site, and this was the (partial) solution I came to. Hope it helps someone!

How to load a model from an HDF5 file in Keras?

load_weights only sets the weights of your network. You still need to define its architecture before calling load_weights:

def create_model():
   model = Sequential()
   model.add(Dense(64, input_dim=14, init='uniform'))
   model.add(LeakyReLU(alpha=0.3))
   model.add(BatchNormalization(epsilon=1e-06, mode=0, momentum=0.9, weights=None))
   model.add(Dropout(0.5)) 
   model.add(Dense(64, init='uniform'))
   model.add(LeakyReLU(alpha=0.3))
   model.add(BatchNormalization(epsilon=1e-06, mode=0, momentum=0.9, weights=None))
   model.add(Dropout(0.5))
   model.add(Dense(2, init='uniform'))
   model.add(Activation('softmax'))
   return model

def train():
   model = create_model()
   sgd = SGD(lr=0.1, decay=1e-6, momentum=0.9, nesterov=True)
   model.compile(loss='binary_crossentropy', optimizer=sgd)

   checkpointer = ModelCheckpoint(filepath="/tmp/weights.hdf5", verbose=1, save_best_only=True)
   model.fit(X_train, y_train, nb_epoch=20, batch_size=16, show_accuracy=True, validation_split=0.2, verbose=2, callbacks=[checkpointer])

def load_trained_model(weights_path):
   model = create_model()
   model.load_weights(weights_path)

What is meant by the term "hook" in programming?

Essentially it's a place in code that allows you to tap in to a module to either provide different behavior or to react when something happens.

deleting folder from java

I wrote a method for this sometime back. It deletes the specified directory and returns true if the directory deletion was successful.

/**
 * Delets a dir recursively deleting anything inside it.
 * @param dir The dir to delete
 * @return true if the dir was successfully deleted
 */
public static boolean deleteDirectory(File dir) {
    if(! dir.exists() || !dir.isDirectory())    {
        return false;
    }

    String[] files = dir.list();
    for(int i = 0, len = files.length; i < len; i++)    {
        File f = new File(dir, files[i]);
        if(f.isDirectory()) {
            deleteDirectory(f);
        }else   {
            f.delete();
        }
    }
    return dir.delete();
}

@AspectJ pointcut for all methods of a class with specific annotation

You should combine a type pointcut with a method pointcut.

These pointcuts will do the work to find all public methods inside a class marked with an @Monitor annotation:

@Pointcut("within(@org.rejeev.Monitor *)")
public void beanAnnotatedWithMonitor() {}

@Pointcut("execution(public * *(..))")
public void publicMethod() {}

@Pointcut("publicMethod() && beanAnnotatedWithMonitor()")
public void publicMethodInsideAClassMarkedWithAtMonitor() {}

Advice the last pointcut that combines the first two and you're done!

If you're interested, I have written a cheat sheet with @AspectJ style here with a corresponding example document here.

Enum String Name from Value

Just need:

string stringName = EnumDisplayStatus.Visible.ToString("f");
// stringName == "Visible"

How to add an item to a drop down list in ASP.NET?

Try this, it will insert the list item at index 0;

DropDownList1.Items.Insert(0, new ListItem("Add New", ""));

Integer division: How do you produce a double?

use something like:

double step = 1d / 5;

(1d is a cast to double)

Set Focus on EditText

    mEditText.setFocusableInTouchMode(true);
    mEditText.requestFocus();

    if(mEditText.requestFocus()) {
        getWindow().setSoftInputMode(WindowManager.LayoutParams.SOFT_INPUT_STATE_ALWAYS_VISIBLE);
    }

how to insert date and time in oracle?

Try this:

...(to_date('2011/04/22 08:30:00', 'yyyy/mm/dd hh24:mi:ss'));

How to get current PHP page name

In your case you can use __FILE__ variable !
It should help.
It is one of predefined.
Read more about predefined constants in PHP http://php.net/manual/en/language.constants.predefined.php

How to group an array of objects by key

In plain Javascript, you could use Array#reduce with an object

_x000D_
_x000D_
var cars = [{ make: 'audi', model: 'r8', year: '2012' }, { make: 'audi', model: 'rs5', year: '2013' }, { make: 'ford', model: 'mustang', year: '2012' }, { make: 'ford', model: 'fusion', year: '2015' }, { make: 'kia', model: 'optima', year: '2012' }],_x000D_
    result = cars.reduce(function (r, a) {_x000D_
        r[a.make] = r[a.make] || [];_x000D_
        r[a.make].push(a);_x000D_
        return r;_x000D_
    }, Object.create(null));_x000D_
_x000D_
console.log(result);
_x000D_
.as-console-wrapper { max-height: 100% !important; top: 0; }
_x000D_
_x000D_
_x000D_

Extracting columns from text file with different delimiters in Linux

You can use cut with a delimiter like this:

with space delim:

cut -d " " -f1-100,1000-1005 infile.csv > outfile.csv

with tab delim:

cut -d$'\t' -f1-100,1000-1005 infile.csv > outfile.csv

I gave you the version of cut in which you can extract a list of intervals...

Hope it helps!

psql: could not connect to server: No such file or directory (Mac OS X)

Hello world :)
The best but strange way for me was to do next things.

1) Download postgres93.app or other version. Add this app into /Applications/ folder.

2) Add a row (command) into the file .bash_profile (which is in my home directory):

export PATH=/Applications/Postgres93.app/Contents/MacOS/bin/:$PATH
It's a PATH to psql from Postgres93.app. The row (command) runs every time console is started.

3) Launch Postgres93.app from /Applications/ folder. It starts a local server (port is "5432" and host is "localhost").

4) After all of this manipulations I was glad to run $ createuser -SRDP user_name and other commands and to see that it worked! Postgres93.app can be made to run every time your system starts.

5) Also if you wanna see your databases graphically you should install PG Commander.app. It's good way to see your postgres DB as pretty data-tables

Of, course, it's helpful only for local server. I will be glad if this instructions help others who has faced with this problem.

Find first element in a sequence that matches a predicate

To find first element in a sequence seq that matches a predicate:

next(x for x in seq if predicate(x))

Or (itertools.ifilter on Python 2):

next(filter(predicate, seq))

It raises StopIteration if there is none.


To return None if there is no such element:

next((x for x in seq if predicate(x)), None)

Or:

next(filter(predicate, seq), None)

Count number of files within a directory in Linux?

this is one:

ls -l . | egrep -c '^-'

Note:

ls -1 | wc -l

Which means: ls: list files in dir

-1: (that's a ONE) only one entry per line. Change it to -1a if you want hidden files too

|: pipe output onto...

wc: "wordcount"

-l: count lines.

Passing parameters to a JDBC PreparedStatement

You should use the setString() method to set the userID. This both ensures that the statement is formatted properly, and prevents SQL injection:

statement =con.prepareStatement("SELECT * from employee WHERE  userID = ?");
statement.setString(1, userID);

There is a nice tutorial on how to use PreparedStatements properly in the Java Tutorials.

How can I delete multiple lines in vi?

If you want to delete a range AFTER a specific line trigger you can use something like this

:g/^TMPDIR/ :.,+11d

That deletes 11 lines (inclusive) after every encounter of ^TMPDIR.

Can I access a form in the controller?

This answer is a little late, but I stumbled upon a solution that makes everything a LOT easier.

You can actually assign the form name directly to your controller if you're using the controllerAs syntax and then reference it from your "this" variable. Here's how I did it in my code:

I configured the controller via ui-router (but you can do it however you want, even in the HTML directly with something like <div ng-controller="someController as myCtrl">) This is what it might look like in a ui-router configuration:

views: {
            "": {
                templateUrl: "someTemplate.html",
                controller: "someController",
                controllerAs: "myCtrl"
            }
       }

and then in the HTML, you just set the form name as the "controllerAs"."name" like so:

<ng-form name="myCtrl.someForm">
    <!-- example form code here -->
    <input name="firstName" ng-model="myCtrl.user.firstName" required>
</ng-form>

now inside your controller you can very simply do this:

angular
.module("something")
.controller("someController",
    [
       "$scope",
        function ($scope) {
            var vm = this;
            if(vm.someForm.$valid){
              // do something
            }
    }]);

How to Troubleshoot Intermittent SQL Timeout Errors

The issue is because of a bad query the time to executing query is taking more than 60 seconds or a Lock on the Table

The issue looks like a deadlock is occurring; we have queries which are blocking the queries to complete in time. The default timeout for a query is 60 secs and beyond that we will have the SQLException for timeout.

Please check the SQL Server logs for deadlocks. The other way to solve the issue to to increase the Timeout on the Command Object (Temp Solution).

Is it possible to forward-declare a function in Python?

You can't forward-declare a function in Python. If you have logic executing before you've defined functions, you've probably got a problem anyways. Put your action in an if __name__ == '__main__' at the end of your script (by executing a function you name "main" if it's non-trivial) and your code will be more modular and you'll be able to use it as a module if you ever need to.

Also, replace that list comprehension with a generator express (i.e., print "\n".join(str(bla) for bla in sorted(mylist, cmp=cmp_configs)))

Also, don't use cmp, which is deprecated. Use key and provide a less-than function.

WCF vs ASP.NET Web API

The new ASP.NET Web API is a continuation of the previous WCF Web API project (although some of the concepts have changed).

WCF was originally created to enable SOAP-based services. For simpler RESTful or RPCish services (think clients like jQuery) ASP.NET Web API should be good choice.


For us, WCF is used for SOAP and Web API for REST. I wish Web API supported SOAP too. We are not using advanced features of WCF. Here is comparison from MSDN:

enter image description here


ASP.net Web API is all about HTTP and REST based GET,POST,PUT,DELETE with well know ASP.net MVC style of programming and JSON returnable; web API is for all the light weight process and pure HTTP based components. For one to go ahead with WCF even for simple or simplest single web service it will bring all the extra baggage. For light weight simple service for ajax or dynamic calls always WebApi just solves the need. This neatly complements or helps in parallel to the ASP.net MVC.

Check out the podcast : Hanselminutes Podcast 264 - This is not your father's WCF - All about the WebAPI with Glenn Block by Scott Hanselman for more information.


In the scenarios listed below you should go for WCF:

  1. If you need to send data on protocols like TCP, MSMQ or MIME
  2. If the consuming client just knows how to consume SOAP messages

WEB API is a framework for developing RESTful/HTTP services.

There are so many clients that do not understand SOAP like Browsers, HTML5, in those cases WEB APIs are a good choice.

HTTP services header specifies how to secure service, how to cache the information, type of the message body and HTTP body can specify any type of content like HTML not just XML as SOAP services.

Getting the parent of a directory in Bash

if for whatever reason you are interested in navigating up a specific number of directories you could also do: nth_path=$(cd "$( dirname "${BASH_SOURCE[0]}" )" >/dev/null 2>&1 && cd ../../../ && pwd). This would give 3 parents directories up

Edit a commit message in SourceTree Windows (already pushed to remote)

If the comment message includes non-English characters, using method provided by user456814, those characters will be replaced by question marks. (tested under sourcetree Ver2.5.5.0)

So I have to use the following method.

CAUTION: if the commit has been pulled by other members, changes below might cause chaos for them.

Step1: In the sourcetree main window, locate your repo tab, and click the "terminal" button to open the git command console.

Step2:

[Situation A]: target commit is the latest one.

1) In the git command console, input

git commit --amend -m "new comment message"

2) If the target commit has been pushed to remote, you have to push again by force. In the git command console, input

git push --force

[Situation B]: target commit is not the latest one.

1) In the git command console, input

git rebase -i HEAD~n

It is to squash the latest n commits. e.g. if you want to edit the message before the last one, n is 2. This command will open a vi window, the first word of each line is "pick", and you change the "pick" to "reword" for the line you want to edit. Then, input :wq to save&quit that vi window. Now, a new vi window will be open, in this window you input your new message. Also use :wq to save&quit.

2) If the target commit has been pushed to remote, you have to push again by force. In the git command console, input

git push --force


Finally: In the sourcetree main window, Press F5 to refresh.

Finding height in Binary Search Tree

int height(Node* root) {
        if(root==NULL) return -1;
        return max(height(root->left),height(root->right))+1;
}

Take of maximum height from left and right subtree and add 1 to it.This also handles the base case(height of Tree with 1 node is 0).

How to trim whitespace from a Bash variable?

var="  a b  "
echo "$(set -f; echo $var)"

>a b

Check if a string is not NULL or EMPTY

if (!$variablename) { Write-Host "variable is null" }

I hope this simple answer will is resolve the question. Source

Side-by-side list items as icons within a div (css)

This can be a pure CSS solution. Given:

<ul class="tileMe">
    <li>item 1<li>
    <li>item 2<li>
    <li>item 3<li>
</ul>

The CSS would be:

.tileMe li {
    display: inline;
    float: left;
}

Now, since you've changed the display mode from 'block' (implied) to 'inline', any padding, margin, width, or height styles you applied to li elements will not work. You need to nest a block-level element inside the li:

<li><a class="tile" href="home">item 1</a></li>

and add the following CSS:

.tile a {
    display: block;
    padding: 10px;
    border: 1px solid red;
    margin-right: 5px;
}

The key concept behind this solution is that you are changing the display style of the li to 'inline', and nesting a block-level element inside to achieve the consistent tiling effect.

What is the difference between partitioning and bucketing a table in Hive ?

There are great responses here. I would like to keep it short to memorize the difference between partition & buckets.

You generally partition on a less unique column. And bucketing on most unique column.

Example if you consider World population with country, person name and their bio-metric id as an example. As you can guess, country field would be the less unique column and bio-metric id would be the most unique column. So ideally you would need to partition the table by country and bucket it by bio-metric id.

How to set custom favicon in Express?

No need for custom middleware?! In express:

 //you probably have something like this already    
app.use("/public", express.static('public')); 

Then put your favicon in public and add the following line in your html's head:

<link rel="icon" href="/public/favicon.ico">

How to find third or n?? maximum salary from salary table?

another way to find last highest data based on date

SELECT A.JID,A.EntryDate,RefundDate,Comments,Refund, ActionBy FROM (
(select JID, Max(EntryDate) AS EntryDate from refundrequested GROUP BY JID) A 
Inner JOIN (SELECT JID,ENTRYDATE,refundDate,Comments,refund,ActionBy from refundrequested) B 
ON A.JID=B.JID AND A.EntryDate = B.EntryDate) 

Insert auto increment primary key to existing table

yes, something like this would do it, might not be the best though, you might wanna make a backup

$get_query = mysql_query("SELECT `any_field` FROM `your_table`");

$auto_increment_id = 1;

while($row = mysql_fetch_assoc($get_query))
{
  $update_query = mysql_query("UPDATE `your_table` SET `auto_increment_id`=$auto_increment_id WHERE `any_field` = '".$row['any_field']."'");
  $auto_increment_id++;
}

notice that the the any_field you select must be the same when updating.

XML Schema Validation : Cannot find the declaration of element

The targetNamespace of your XML Schema does not match the namespace of the Root element (dot in Test.Namespace vs. comma in Test,Namespace)

Once you make the above agree, you have to consider that your element2 has an attribute order that is not in your XSD.

How to trim a string in SQL Server before 2017?

SELECT LTRIM(RTRIM(Names)) AS Names FROM Customer

Oracle: If Table Exists

BEGIN
   EXECUTE IMMEDIATE 'DROP TABLE "IMS"."MAX" ';
EXCEPTION
   WHEN OTHERS THEN
      IF SQLCODE != -942 THEN
         RAISE;
          END IF;
         EXECUTE IMMEDIATE ' 
  CREATE TABLE "IMS"."MAX" 
   (    "ID" NUMBER NOT NULL ENABLE, 
    "NAME" VARCHAR2(20 BYTE), 
     CONSTRAINT "MAX_PK" PRIMARY KEY ("ID")
  USING INDEX PCTFREE 10 INITRANS 2 MAXTRANS 255 
  STORAGE(INITIAL 65536 NEXT 1048576 MINEXTENTS 1 MAXEXTENTS 2147483645
  PCTINCREASE 0 FREELISTS 1 FREELIST GROUPS 1 BUFFER_POOL DEFAULT FLASH_CACHE DEFAULT CELL_FLASH_CACHE DEFAULT)
  TABLESPACE "SYSAUX"  ENABLE
   ) SEGMENT CREATION IMMEDIATE 
  PCTFREE 10 PCTUSED 40 INITRANS 1 MAXTRANS 255 NOCOMPRESS LOGGING
  STORAGE(INITIAL 65536 NEXT 1048576 MINEXTENTS 1 MAXEXTENTS 2147483645
  PCTINCREASE 0 FREELISTS 1 FREELIST GROUPS 1 BUFFER_POOL DEFAULT FLASH_CACHE DEFAULT CELL_FLASH_CACHE DEFAULT)
  TABLESPACE "SYSAUX"  ';


END;

// Doing this code, checks if the table exists and later it creates the table max. this simply works in single compilation

Java Security: Illegal key size or default parameters?

I experienced the same error while using Windows 7 x64, Eclipse, and JDK 1.6.0_30. In the JDK installation folder there is a jre folder. This threw me off at first as I was adding the aforementioned jars to the JDK's lib/security folder with no luck. Full path:

C:\Program Files\Java\jdk1.6.0_30\jre\lib\security

Download and extract the files contained in the jce folder of this archive into that folder.

Is there any "font smoothing" in Google Chrome?

Ok you can use this simply

-webkit-text-stroke-width: .7px;
-webkit-text-stroke-color: #34343b;
-webkit-font-smoothing:antialiased;

Make sure your text color and upper text-stroke-width must me same and that's it.

How to clamp an integer to some range?

See numpy.clip:

index = numpy.clip(index, 0, len(my_list) - 1)

Why is a ConcurrentModificationException thrown and how to debug it

This is not a synchronization problem. This will occur if the underlying collection that is being iterated over is modified by anything other than the Iterator itself.

Iterator it = map.entrySet().iterator();
while (it.hasNext())
{
   Entry item = it.next();
   map.remove(item.getKey());
}

This will throw a ConcurrentModificationException when the it.hasNext() is called the second time.

The correct approach would be

   Iterator it = map.entrySet().iterator();
   while (it.hasNext())
   {
      Entry item = it.next();
      it.remove();
   }

Assuming this iterator supports the remove() operation.

Unix's 'ls' sort by name

The beauty of *nix tools is you can combine them:

ls -l | sort -k9,9

The output of ls -l will look like this

-rw-rw-r-- 1 luckydonald luckydonald  532 Feb 21  2017 Makefile
-rwxrwxrwx 1 luckydonald luckydonald 4096 Nov 17 23:47 file.txt

So with 9,9 you sort column 9 up to the column 9, being the file names. You have to provide where to stop, which is the same column in this case. The columns start with 1.

Also, if you want to ignore upper/lower case, add --ignore-case to the sort command.

How to restart a windows service using Task Scheduler

Instead of using a bat file, you can simply create a Scheduled Task. Most of the time you define just one action. In this case, create two actions with the NET command. The first one to stop the service, the second one to start the service. Give them a STOP and START argument, followed by the service name.

In this example we restart the Printer Spooler service.

NET STOP "Print Spooler" 
NET START "Print Spooler"

enter image description here

enter image description here

Note: unfortunately NET RESTART <service name> does not exist.

MySql Error: 1364 Field 'display_name' doesn't have default value

I also had this issue using Lumen, but fixed by setting DB_STRICT_MODE=false in .env file.

How can I get a list of all functions stored in the database of a particular schema in PostgreSQL?

Example:

perfdb-# \df information_schema.*;

List of functions
        Schema      |        Name        | Result data type | Argument data types |  Type  
 information_schema | _pg_char_max_length   | integer | typid oid, typmod integer | normal
 information_schema | _pg_char_octet_length | integer | typid oid, typmod integer | normal
 information_schema | _pg_datetime_precision| integer | typid oid, typmod integer | normal
 .....
 information_schema | _pg_numeric_scale     | integer | typid oid, typmod integer | normal
 information_schema | _pg_truetypid         | oid     | pg_attribute, pg_type     | normal
 information_schema | _pg_truetypmod        | integer | pg_attribute, pg_type     | normal
(11 rows)

Java Thread Example?

There is no guarantee that your threads are executing simultaneously regardless of any trivial example anyone else posts. If your OS only gives the java process one processor to work on, your java threads will still be scheduled for each time slice in a round robin fashion. Meaning, no two will ever be executing simultaneously, but the work they do will be interleaved. You can use monitoring tools like Java's Visual VM (standard in the JDK) to observe the threads executing in a Java process.

How can I display the current branch and folder path in terminal?

Keep it fast, keep it simple

put this in your ~/.bashrc file.

git_stuff() {
  git_branch=$(git branch --show-current 2> /dev/null)
  if [[ $git_branch == "" ]];then
    echo -e ""
  elif [[ $git_branch == *"Nocommit"* ]];then
    echo -e "No commits"
  else
    echo -e "$git_branch"
  fi
}
prompt() {
  PS1="\e[2m$(date +%H:%M:%S.%3N) \e[4m$(git_stuff)\033[0m\n\w$ "
}
PROMPT_COMMAND=prompt

Then source ~/.bashrc

enter image description here

Checking during array iteration, if the current element is the last element

If the items are numerically ordered, use the key() function to determine the index of the current item and compare it to the length. You'd have to use next() or prev() to cycle through items in a while loop instead of a for loop:

$length = sizeOf($arr);
while (key(current($arr)) != $length-1) {
    $v = current($arr); doSomething($v); //do something if not the last item
    next($myArray); //set pointer to next item
}

Can I change the fill color of an svg path with CSS?

Yes, you can apply CSS to SVG, but you need to match the element, just as when styling HTML. If you just want to apply it to all SVG paths, you could use, for example:

?path {
    fill: blue;
}?

External CSS appears to override the path's fill attribute, at least in WebKit and Gecko-based browsers I tested. Of course, if you write, say, <path style="fill: green"> then that will override external CSS as well.

Determine if map contains a value for a key?

I just noticed that with C++20, we will have

bool std::map::contains( const Key& key ) const;

That will return true if map holds an element with key key.

MySQL ON DUPLICATE KEY UPDATE for multiple rows insert in single query

Beginning with MySQL 8.0.19 you can use an alias for that row (see reference).

INSERT INTO beautiful (name, age)
    VALUES
    ('Helen', 24),
    ('Katrina', 21),
    ('Samia', 22),
    ('Hui Ling', 25),
    ('Yumie', 29)
    AS new
ON DUPLICATE KEY UPDATE
    age = new.age
    ...

For earlier versions use the keyword VALUES (see reference, deprecated with MySQL 8.0.20).

INSERT INTO beautiful (name, age)
    VALUES
    ('Helen', 24),
    ('Katrina', 21),
    ('Samia', 22),
    ('Hui Ling', 25),
    ('Yumie', 29)
ON DUPLICATE KEY UPDATE
    age = VALUES(age),
     ...

Get names of all keys in the collection

I have 1 simpler work around...

What you can do is while inserting data/document into your main collection "things" you must insert the attributes in 1 separate collection lets say "things_attributes".

so every time you insert in "things", you do get from "things_attributes" compare values of that document with your new document keys if any new key present append it in that document and again re-insert it.

So things_attributes will have only 1 document of unique keys which you can easily get when ever you require by using findOne()

How to tune Tomcat 5.5 JVM Memory settings without using the configuration program

Just to add to the previous comment, the documentation for the command line tool for updating the Tomcat service settings (if Tomcat is running as a service on Windows) is here. This tool updates the registry with the proper settings. So if you wanted to update the max memory setting for the Tomcat service you could run this (from the tomcat/bin directory), assuming the default service name of Tomcat5:

tomcat5 //US//Tomcat5 --JvmMx=512

"End of script output before headers" error in Apache

Probably this is an SELinux block. Try this:

# setsebool -P httpd_enable_cgi 1
# chcon -R -t httpd_sys_script_exec_t cgi-bin/your_script.cgi

How do I make a relative reference to another workbook in Excel?

easier & shorter via indirect: INDIRECT("'..\..\..\..\Supply\SU\SU.ods'#$Data.$A$2:$AC$200")

however indirect() has performance drawbacks if lot of links in workbook

I miss construct like: ['../Data.ods']#Sheet1.A1 in LibreOffice. The intention is here: if I create a bunch of master workbooks and depending report workbooks in limited subtree of directories in source file system, I can zip whole directory subtree with complete package of workbooks and send it to other cooperating person per Email or so. It will be saved in some other absolute pazth on target system, but linkage works again in new absolute path because it was coded relatively to subtree root.

How to detect IE11?

var ua = navigator.userAgent.toString().toLowerCase();
var match = /(trident)(?:.*rv:([\w.]+))?/.exec(ua) ||/(msie) ([\w.]+)/.exec(ua)||['',null,-1];
var rv = match[2];
return rv;

Can't open config file: /usr/local/ssl/openssl.cnf on Windows

Not sure what is the difference between .cfg & .cnf In my server I couldn't find .cfg or .cnf I had created a new file for the same and placed it in the following folder /usr/local/ssl/bin

executed the

.\openssl genrsa -des3 -out <key name>.key 2048 

went great..

count (non-blank) lines-of-code in bash

cat 'filename' | grep '[^ ]' | wc -l

should do the trick just fine

How to access shared folder without giving username and password

I found one way to access the shared folder without giving the username and password.

We need to change the share folder protect settings in the machine where the folder has been shared.

Go to Control Panel > Network and sharing center > Change advanced sharing settings > Enable Turn Off password protect sharing option.

By doing the above settings we can access the shared folder without any username/password.

Why don’t my SVG images scale using the CSS "width" property?

The transform CSS property lets you rotate, scale, skew, or translate an element.

So you can easily use the transform: scale(2.5); option to scale 2.5 times for example.

Access restriction: The type 'Application' is not API (restriction on required library rt.jar)

If you're having this same issue using Spring Tool Suite:

The Spring Tool Suite's underlying IDE is, in fact, Eclipse. I've gotten this error just now trying to use some com.sun.net classes. To remove these errors and prevent them from popping up in the Eclipse Luna SR1 (4.4.2) platform of STS:

  • Navigate to Project > Properties
  • Expand the Java Compiler heading
  • Click on Errors/Warnings
  • Expand deprecated and restricted API
  • Next to "Forbidden reference (access rules)" select "ignore"
  • Next to "Discouraged reference (access rules)" select "ignore"

You're good to go.

How to prevent line-break in a column of a table cell (not a single cell)?

Put non-breaking spaces in your text instead of normal spaces. On Ubuntu I do this with (Compose Key)-space-space.

What is the format specifier for unsigned short int?

For scanf, you need to use %hu since you're passing a pointer to an unsigned short. For printf, it's impossible to pass an unsigned short due to default promotions (it will be promoted to int or unsigned int depending on whether int has at least as many value bits as unsigned short or not) so %d or %u is fine. You're free to use %hu if you prefer, though.

Is it possible to embed animated GIFs in PDFs?

Another possibility is LaTeX + animate package. You will need to provide the individual frames making the animation. The resulting pdf does NOT require any plugin, the animation is shown in Adobe reader

functional way to iterate over range (ES6/7)

ES7 Proposal

Warning: Unfortunately I believe most popular platforms have dropped support for comprehensions. See below for the well-supported ES6 method

You can always use something like:

[for (i of Array(7).keys()) i*i];

Running this code on Firefox:

[ 0, 1, 4, 9, 16, 25, 36 ]

This works on Firefox (it was a proposed ES7 feature), but it has been dropped from the spec. IIRC, Babel 5 with "experimental" enabled supports this.

This is your best bet as array-comprehension are used for just this purpose. You can even write a range function to go along with this:

var range = (u, l = 0) => [ for( i of Array(u - l).keys() ) i + l ]

Then you can do:

[for (i of range(5)) i*i] // 0, 1, 4, 9, 16, 25
[for (i of range(5,3)) i*i] // 9, 16, 25

ES6

A nice way to do this any of:

[...Array(7).keys()].map(i => i * i);
Array(7).fill().map((_,i) => i*i);
[...Array(7)].map((_,i) => i*i);

This will output:

[ 0, 1, 4, 9, 16, 25, 36 ]

Junit test case for database insert method with DAO and web service

@Test
public void testSearchManagementStaff() throws SQLException
{
    boolean res=true;
    ManagementDaoImp mdi=new ManagementDaoImp();
    boolean b=mdi.searchManagementStaff("[email protected]"," 123456");
    assertEquals(res,b);
}

Find Locked Table in SQL Server

You can use sp_lock (and sp_lock2), but in SQL Server 2005 onwards this is being deprecated in favour of querying sys.dm_tran_locks:

select  
    object_name(p.object_id) as TableName, 
    resource_type, resource_description
from
    sys.dm_tran_locks l
    join sys.partitions p on l.resource_associated_entity_id = p.hobt_id

sweet-alert display HTML code in text

Sweet alerts also has an 'html' option, set it to true.

var hh = "<b>test</b>";
swal({
    title: "" + txt + "", 
    html: true,
    text: "Testno  sporocilo za objekt " + hh + "",  
    confirmButtonText: "V redu", 
    allowOutsideClick: "true" 
});

Assembly code vs Machine code vs Object code?

Assembly code is discussed here.

"An assembly language is a low-level language for programming computers. It implements a symbolic representation of the numeric machine codes and other constants needed to program a particular CPU architecture."

Machine code is discussed here.

"Machine code or machine language is a system of instructions and data executed directly by a computer's central processing unit."

Basically, assembler code is the language and it is translated to object code (the native code that the CPU runs) by an assembler (analogous to a compiler).

How do I use CREATE OR REPLACE?

One of the nice things about the syntax is that you can be sure that a CREATE OR REPLACE will never cause you to lose data (the most you will lose is code, which hopefully you'll have stored in source control somewhere).

The equivalent syntax for tables is ALTER, which means you have to explicitly enumerate the exact changes that are required.

EDIT: By the way, if you need to do a DROP + CREATE in a script, and you don't care for the spurious "object does not exist" errors (when the DROP doesn't find the table), you can do this:

BEGIN
  EXECUTE IMMEDIATE 'DROP TABLE owner.mytable';
EXCEPTION
  WHEN OTHERS THEN
    IF sqlcode != -0942 THEN RAISE; END IF;
END;
/

Serializing and submitting a form with jQuery and PHP

Have you checked in console if data from form is properly serialized? Is ajax request successful? Also you didn't close placeholder quote in, which can cause some problems:

 <textarea name="comentarii" cols="36" rows="5" placeholder="Message>  

Credit card payment gateway in PHP?

Stripe has a PHP library to accept credit cards without needing a merchant account: https://github.com/stripe/stripe-php

Check out the documentation and FAQ, and feel free to drop by our chatroom if you have more questions.

A long bigger than Long.MAX_VALUE

That method can't return true. That's the point of Long.MAX_VALUE. It would be really confusing if its name were... false. Then it should be just called Long.SOME_FAIRLY_LARGE_VALUE and have literally zero reasonable uses. Just use Android's isUserAGoat, or you may roll your own function that always returns false.

Note that a long in memory takes a fixed number of bytes. From Oracle:

long: The long data type is a 64-bit signed two's complement integer. It has a minimum value of -9,223,372,036,854,775,808 and a maximum value of 9,223,372,036,854,775,807 (inclusive). Use this data type when you need a range of values wider than those provided by int.

As you may know from basic computer science or discrete math, there are 2^64 possible values for a long, since it is 64 bits. And as you know from discrete math or number theory or common sense, if there's only finitely many possibilities, one of them has to be the largest. That would be Long.MAX_VALUE. So you are asking something similar to "is there an integer that's >0 and < 1?" Mathematically nonsensical.

If you actually need this for something for real then use BigInteger class.

How to make jQuery UI nav menu horizontal?

You can do this:

/* Clearfix for the menu */
.ui-menu:after {
    content: ".";
    display: block;
    clear: both;
    visibility: hidden;
    line-height: 0;
    height: 0;
}

and also set:

.ui-menu .ui-menu-item {
    display: inline-block;
    float: left;
    margin: 0;
    padding: 0;
    width: auto;
}

What's better at freeing memory with PHP: unset() or $var = null

<?php
$start = microtime(true);
for ($i = 0; $i < 10000000; $i++) {
    $a = 'a';
    $a = NULL;
}
$elapsed = microtime(true) - $start;

echo "took $elapsed seconds\r\n";



$start = microtime(true);
for ($i = 0; $i < 10000000; $i++) {
    $a = 'a';
    unset($a);
}
$elapsed = microtime(true) - $start;

echo "took $elapsed seconds\r\n";
?>

Per that it seems like "= null" is faster.

PHP 5.4 results:

  • took 0.88389301300049 seconds
  • took 2.1757180690765 seconds

PHP 5.3 results:

  • took 1.7235369682312 seconds
  • took 2.9490959644318 seconds

PHP 5.2 results:

  • took 3.0069220066071 seconds
  • took 4.7002630233765 seconds

PHP 5.1 results:

  • took 2.6272349357605 seconds
  • took 5.0403649806976 seconds

Things start to look different with PHP 5.0 and 4.4.

5.0:

  • took 10.038941144943 seconds
  • took 7.0874409675598 seconds

4.4:

  • took 7.5352551937103 seconds
  • took 6.6245851516724 seconds

Keep in mind microtime(true) doesn't work in PHP 4.4 so I had to use the microtime_float example given in php.net/microtime / Example #1.

How to Test Facebook Connect Locally

Looks like FB just changed the app dev page again and added a feature called "Server IP Whitelist".

  1. Go to your app and Select Settings -> Advanced Tab
  2. Get your public IP (google will tell you if you google "Whats My IP")
  3. Add your public IP to the Server IP Whitelist and click Save Changes at the bottom

How do I download NLTK data?

Try download the zip files from http://www.nltk.org/nltk_data/ and then unzip, save in your Python folder, such as C:\ProgramData\Anaconda3\nltk_data

How to upload a project to Github

I think the easiest thing for you to do would be to install the git plugin for eclipse, works more or less the same as eclipse CVS and SVN plugins:

http://www.eclipse.org/egit/

GL!

Turn a single number into single digits Python

If you want to change your number into a list of those numbers, I would first cast it to a string, then casting it to a list will naturally break on each character:

[int(x) for x in str(n)]

Int to Char in C#

Although not exactly answering the question as formulated, but if you need or can take the end result as string you can also use

string s = Char.ConvertFromUtf32(56);

which will give you surrogate UTF-16 pairs if needed, protecting you if you are out side of the BMP.

Should I make HTML Anchors with 'name' or 'id'?

You shouldn’t use <h1><a name="foo"/>Foo Title</h1> in any flavor of HTML served as text/html, because the XML empty element syntax isn’t supported in text/html. However, <h1><a name="foo">Foo Title</a></h1> is OK in HTML4. It is not valid in HTML5 as currently drafted.

<h1 id="foo">Foo Title</h1> is OK in both HTML4 and HTML5. This won’t work in Netscape 4, but you’ll probably use a dozen other features that don’t work in Netscape 4.

Sending Multipart File as POST parameters with RestTemplate requests

I also ran into the same issue the other day. Google search got me here and several other places, but none gave the solution to this issue. I ended up saving the uploaded file (MultiPartFile) as a tmp file, then use FileSystemResource to upload it via RestTemplate. Here's the code I use,

String tempFileName = "/tmp/" + multiFile.getOriginalFileName();
FileOutputStream fo = new FileOutputStream(tempFileName);

fo.write(asset.getBytes());    
fo.close();   

parts.add("file", new FileSystemResource(tempFileName));    
String response = restTemplate.postForObject(uploadUrl, parts, String.class, authToken, path);   


//clean-up    
File f = new File(tempFileName);    
f.delete();

I am still looking for a more elegant solution to this problem.

How to send an email using PHP?

Try this:

<?php
$to = "[email protected]";
$subject = "My subject";
$txt = "Hello world!";
$headers = "From: [email protected]" . "\r\n" .
"CC: [email protected]";

mail($to,$subject,$txt,$headers);
?>

Singleton in Android

You are copying singleton's customVar into a singletonVar variable and changing that variable does not affect the original value in singleton.

// This does not update singleton variable
// It just assigns value of your local variable
Log.d("Test",singletonVar);
singletonVar="World";
Log.d("Test",singletonVar);

// This actually assigns value of variable in singleton
Singleton.customVar = singletonVar;

How to fix org.hibernate.LazyInitializationException - could not initialize proxy - no Session

There are several good answers here that handle this error in a broad scope. I ran into a specific situation with Spring Security which had a quick, although probably not optimal, fix.

During user authorization (immediately after logging in and passing authentication) I was testing a user entity for a specific authority in a custom class that extends SimpleUrlAuthenticationSuccessHandler.

My user entity implements UserDetails and has a Set of lazy loaded Roles which threw the "org.hibernate.LazyInitializationException - could not initialize proxy - no Session" exception. Changing that Set from "fetch=FetchType.LAZY" to "fetch=FetchType.EAGER" fixed this for me.

Spring: How to inject a value to static field?

This is my sample code for load static variable

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Component;

@Component
public class OnelinkConfig {
    public static int MODULE_CODE;
    public static int DEFAULT_PAGE;
    public static int DEFAULT_SIZE;

    @Autowired
    public void loadOnelinkConfig(@Value("${onelink.config.exception.module.code}") int code,
            @Value("${onelink.config.default.page}") int page, @Value("${onelink.config.default.size}") int size) {
        MODULE_CODE = code;
        DEFAULT_PAGE = page;
        DEFAULT_SIZE = size;
    }
}

What is the difference between putting a property on application.yml or bootstrap.yml in spring boot?

bootstrap.yml or bootstrap.properties

It's only used/needed if you're using Spring Cloud and your application's configuration is stored on a remote configuration server (e.g. Spring Cloud Config Server).

From the documentation:

A Spring Cloud application operates by creating a "bootstrap" context, which is a parent context for the main application. Out of the box it is responsible for loading configuration properties from the external sources, and also decrypting properties in the local external configuration files.

Note that the bootstrap.yml or bootstrap.properties can contain additional configuration (e.g. defaults) but generally you only need to put bootstrap config here.

Typically it contains two properties:

  • location of the configuration server (spring.cloud.config.uri)
  • name of the application (spring.application.name)

Upon startup, Spring Cloud makes an HTTP call to the config server with the name of the application and retrieves back that application's configuration.

application.yml or application.properties

Contains standard application configuration - typically default configuration since any configuration retrieved during the bootstrap process will override configuration defined here.

Function overloading in Python: Missing

As unwind noted, keyword arguments with default values can go a long way.

I'll also state that in my opinion, it goes against the spirit of Python to worry a lot about what types are passed into methods. In Python, I think it's more accepted to use duck typing -- asking what an object can do, rather than what it is.

Thus, if your method may accept a string or a tuple, you might do something like this:

def print_names(names):
    """Takes a space-delimited string or an iterable"""
    try:
        for name in names.split(): # string case
            print name
    except AttributeError:
        for name in names:
            print name

Then you could do either of these:

print_names("Ryan Billy")
print_names(("Ryan", "Billy"))

Although an API like that sometimes indicates a design problem.

Why doesn't java.io.File have a close method?

A BufferedReader can be opened and closed but a File is never opened, it just represents a path in the filesystem.

How to loop through each and every row, column and cells in a GridView and get its value

foreach (DataGridViewRow row in dataGridView1.Rows)
        {
            for (int i = 0; i < dataGridView1.Columns.Count; i++)
            {
                String header = dataGridView1.Columns[i].HeaderText;
                //String cellText = row.Cells[i].Text;
                DataGridViewColumn column = dataGridView1.Columns[i]; // column[1] selects the required column 
                column.AutoSizeMode = DataGridViewAutoSizeColumnMode.AllCells; // sets the AutoSizeMode of column defined in previous line
                int colWidth = column.Width; // store columns width after auto resize           
                colWidth += 50; // add 30 pixels to what 'colWidth' already is
                this.dataGridView1.Columns[i].Width = colWidth; // set the columns width to the value stored in 'colWidth'
            }
        }

Add shadow to custom shape on Android

if you need a straight line shadow (like in bottom of toolbar) you can also use gradient xml:

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android">
    <gradient
        android:type="linear"
        android:angle="-90"
        android:startColor="#19000000" <!-- black transparent -->
        android:endColor="#00000000" /> <!-- full transparent -->
</shape>

hope this help some one

error::make_unique is not a member of ‘std’

If you are stuck with c++11, you can get make_unique from abseil-cpp, an open source collection of C++ libraries drawn from Google’s internal codebase.

How to ignore a particular directory or file for tslint?

linterOptions is currently only handled by the CLI. If you're not using CLI then depending on the code base you're using you'll need to set the ignore somewhere else. webpack, tsconfig, etc

Change Twitter Bootstrap Tooltip content on click

you can use this code to hide the tool tip change its title and show the tooltip again, when the ajax request returns successfully.

$(element).tooltip('hide');
$(element).attr('title','this is new title');
$(element).tooltip('fixTitle');
setTimeout(function() {  $(element).tooltip('show');}, 500);

What's the proper value for a checked attribute of an HTML checkbox?

Strictly speaking, you should put something that makes sense - according to the spec here, the most correct version is:

<input name=name id=id type=checkbox checked=checked>

For HTML, you can also use the empty attribute syntax, checked="", or even simply checked (for stricter XHTML, this is not supported).

Effectively, however, most browsers will support just about any value between the quotes. All of the following will be checked:

<input name=name id=id type=checkbox checked>
<input name=name id=id type=checkbox checked="">
<input name=name id=id type=checkbox checked="yes">
<input name=name id=id type=checkbox checked="blue">
<input name=name id=id type=checkbox checked="false">

And only the following will be unchecked:

<input name=name id=id type=checkbox>

See also this similar question on disabled="disabled".

How to grep, excluding some patterns?

Just use awk, it's much simpler than grep in letting you clearly express compound conditions.

If you want to skip lines that contains both loom and gloom:

awk '/loom/ && !/gloom/{ print FILENAME, FNR, $0 }' ~/projects/**/trunk/src/**/*.@(h|cpp)

or if you want to print them:

awk '/(^|[^g])loom/{ print FILENAME, FNR, $0 }' ~/projects/**/trunk/src/**/*.@(h|cpp)

and if the reality is you just want lines where loom appears as a word by itself:

awk '/\<loom\>/{ print FILENAME, FNR, $0 }' ~/projects/**/trunk/src/**/*.@(h|cpp)

sqlalchemy: how to join several tables by one query?

This function will produce required table as list of tuples.

def get_documents_by_user_email(email):
    query = session.query(
       User.email, 
       User.name, 
       Document.name, 
       DocumentsPermissions.readAllowed, 
       DocumentsPermissions.writeAllowed,
    )
    join_query = query.join(Document).join(DocumentsPermissions)

    return join_query.filter(User.email == email).all()

user_docs = get_documents_by_user_email(email)

CSS div 100% height

CSS Flexbox was designed to simplify creating these types of layouts.

_x000D_
_x000D_
html {
  height: 100%;
}

body {
  height: 100%;
  display: flex;
}

.Content {
  flex-grow: 1;
}

.Sidebar {
  width: 290px;
  flex-shrink: 0;
}
_x000D_
<div class="Content" style="background:#bed">Content</div>
<div class="Sidebar" style="background:#8cc">Sidebar</div>
_x000D_
_x000D_
_x000D_

SQL Server: SELECT only the rows with MAX(DATE)

Try to avoid IN use JOIN

SELECT SQL_CALC_FOUND_ROWS *  FROM (SELECT  msisdn, callid, Change_color, play_file_name, date_played FROM insert_log
   WHERE play_file_name NOT IN('Prompt1','Conclusion_Prompt_1','silent')
 ORDER BY callid ASC) t1 JOIN (SELECT MAX(date_played) AS date_played FROM insert_log GROUP BY callid) t2 ON t1.date_played=t2.date_played

Jquery Change Height based on Browser Size/Resize

If you are using jQuery 1.2 or newer, you can simply use these:

$(window).width();
$(document).width();
$(window).height();
$(document).height();

From there it is a simple matter to decide the height of your element.

How to get values from IGrouping

From definition of IGrouping :

IGrouping<out TKey, out TElement> : IEnumerable<TElement>, IEnumerable

you can just iterate through elements like this:

IEnumerable<IGrouping<int, smth>> groups = list.GroupBy(x => x.ID)
foreach(IEnumerable<smth> element in groups)
{
//do something
}

Git: can't undo local changes (error: path ... is unmerged)

git checkout origin/[branch] .
git status

// Note dot (.) at the end. And all will be good

Print execution time of a shell command

Adding to @mob's answer:

Appending %N to date +%s gives us nanosecond accuracy:

start=`date +%s%N`;<command>;end=`date +%s%N`;echo `expr $end - $start`

Java logical operator short-circuiting

Logical OR :- returns true if at least one of the operands evaluate to true. Both operands are evaluated before apply the OR operator.

Short Circuit OR :- if left hand side operand returns true, it returns true without evaluating the right hand side operand.

Reference an Element in a List of Tuples

So you have "a list of tuples", let me assume that you are manipulating some 2-dimension matrix, and, in this case, one convenient interface to accomplish what you need is the one numpy provides.

Say you have an array arr = numpy.array([[1, 2], [3, 4], [5, 6]]), you can use arr[:, 0] to get a new array of all the first elements in each "tuple".

ng-model for `<input type="file"/>` (with directive DEMO)

function filesModelDirective(){
  return {
    controller: function($parse, $element, $attrs, $scope){
      var exp = $parse($attrs.filesModel);
      $element.on('change', function(){
        exp.assign($scope, this.files[0]);
        $scope.$apply();
      });
    }
  };
}
app.directive('filesModel', filesModelDirective);

How to support UTF-8 encoding in Eclipse

Just right click the Project -- Properties and select Resource on the left side menu.

You can now change the Text-file encoding to whatever you wish.

jquery data selector

I've created a new data selector that should enable you to do nested querying and AND conditions. Usage:

$('a:data(category==music,artist.name==Madonna)');

The pattern is:

:data( {namespace} [{operator} {check}]  )

"operator" and "check" are optional. So, if you only have :data(a.b.c) it will simply check for the truthiness of a.b.c.

You can see the available operators in the code below. Amongst them is ~= which allows regex testing:

$('a:data(category~=^mus..$,artist.name~=^M.+a$)');

I've tested it with a few variations and it seems to work quite well. I'll probably add this as a Github repo soon (with a full test suite), so keep a look out!

The code:

(function(){

    var matcher = /\s*(?:((?:(?:\\\.|[^.,])+\.?)+)\s*([!~><=]=|[><])\s*("|')?((?:\\\3|.)*?)\3|(.+?))\s*(?:,|$)/g;

    function resolve(element, data) {

        data = data.match(/(?:\\\.|[^.])+(?=\.|$)/g);

        var cur = jQuery.data(element)[data.shift()];

        while (cur && data[0]) {
            cur = cur[data.shift()];
        }

        return cur || undefined;

    }

    jQuery.expr[':'].data = function(el, i, match) {

        matcher.lastIndex = 0;

        var expr = match[3],
            m,
            check, val,
            allMatch = null,
            foundMatch = false;

        while (m = matcher.exec(expr)) {

            check = m[4];
            val = resolve(el, m[1] || m[5]);

            switch (m[2]) {
                case '==': foundMatch = val == check; break;
                case '!=': foundMatch = val != check; break;
                case '<=': foundMatch = val <= check; break;
                case '>=': foundMatch = val >= check; break;
                case '~=': foundMatch = RegExp(check).test(val); break;
                case '>': foundMatch = val > check; break;
                case '<': foundMatch = val < check; break;
                default: if (m[5]) foundMatch = !!val;
            }

            allMatch = allMatch === null ? foundMatch : allMatch && foundMatch;

        }

        return allMatch;

    };

}());

How to modify a global variable within a function in bash?

A solution to this problem, without having to introduce complex functions and heavily modify the original one, is to store the value in a temporary file and read / write it when needed.

This approach helped me greatly when I had to mock a bash function called multiple times in a bats test case.

For example, you could have:

# Usage read_value path_to_tmp_file
function read_value {
  cat "${1}"
}

# Usage: set_value path_to_tmp_file the_value
function set_value {
  echo "${2}" > "${1}"
}
#----

# Original code:

function test1() {
  e=4
  set_value "${tmp_file}" "${e}"
  echo "hello"
}


# Create the temp file
# Note that tmp_file is available in test1 as well
tmp_file=$(mktemp)

# Your logic
e=2
# Store the value
set_value "${tmp_file}" "${e}"

# Run test1
test1

# Read the value modified by test1
e=$(read_value "${tmp_file}")
echo "$e"

The drawback is that you might need multiple temp files for different variables. And also you might need to issue a sync command to persist the contents on the disk between one write and read operations.

Select from one table where not in another

Expanding on Sjoerd's anti-join, you can also use the easy to understand SELECT WHERE X NOT IN (SELECT) pattern.

SELECT pm.id FROM r2r.partmaster pm
WHERE pm.id NOT IN (SELECT pd.part_num FROM wpsapi4.product_details pd)

Note that you only need to use ` backticks on reserved words, names with spaces and such, not with normal column names.

On MySQL 5+ this kind of query runs pretty fast.
On MySQL 3/4 it's slow.

Make sure you have indexes on the fields in question
You need to have an index on pm.id, pd.part_num.

jQuery - Sticky header that shrinks when scrolling down

This should be what you are looking for using jQuery.

$(function(){
  $('#header_nav').data('size','big');
});

$(window).scroll(function(){
  if($(document).scrollTop() > 0)
{
    if($('#header_nav').data('size') == 'big')
    {
        $('#header_nav').data('size','small');
        $('#header_nav').stop().animate({
            height:'40px'
        },600);
    }
}
else
  {
    if($('#header_nav').data('size') == 'small')
      {
        $('#header_nav').data('size','big');
        $('#header_nav').stop().animate({
            height:'100px'
        },600);
      }  
  }
});

Demonstration: http://jsfiddle.net/jezzipin/JJ8Jc/

Change one value based on another value in pandas

I found it much easier to debut by printing out where each row meets the condition:

for n in df.columns:
    if(np.where(df[n] == 103)):
        print(n)
        print(df[df[n] == 103].index)

How to get df linux command output always in GB

You can use the -B option.

Man page of df:

-B, --block-size=SIZE use SIZE-byte blocks

All together,

df -BG

Action Image MVC3 Razor

Building on Lucas's answer above, this is an overload that takes a controller name as parameter, similar to ActionLink. Use this overload when your image links to an Action in a different controller.

// Extension method
public static MvcHtmlString ActionImage(this HtmlHelper html, string action, string controllerName, object routeValues, string imagePath, string alt)
{
    var url = new UrlHelper(html.ViewContext.RequestContext);

    // build the <img> tag
    var imgBuilder = new TagBuilder("img");
    imgBuilder.MergeAttribute("src", url.Content(imagePath));
    imgBuilder.MergeAttribute("alt", alt);
    string imgHtml = imgBuilder.ToString(TagRenderMode.SelfClosing);

    // build the <a> tag
    var anchorBuilder = new TagBuilder("a");

    anchorBuilder.MergeAttribute("href", url.Action(action, controllerName, routeValues));
    anchorBuilder.InnerHtml = imgHtml; // include the <img> tag inside
    string anchorHtml = anchorBuilder.ToString(TagRenderMode.Normal);

    return MvcHtmlString.Create(anchorHtml);
}

How can I enable CORS on Django REST Framework

pip install django-cors-headers

and then add it to your installed apps:

INSTALLED_APPS = (
    ...
    'corsheaders',
    ...
)

You will also need to add a middleware class to listen in on responses:

MIDDLEWARE_CLASSES = (
    ...
    'corsheaders.middleware.CorsMiddleware',  
    'django.middleware.common.CommonMiddleware',  
    ...
)

CORS_ORIGIN_ALLOW_ALL = True # If this is used then `CORS_ORIGIN_WHITELIST` will not have any effect
CORS_ALLOW_CREDENTIALS = True
CORS_ORIGIN_WHITELIST = [
    'http://localhost:3030',
] # If this is used, then not need to use `CORS_ORIGIN_ALLOW_ALL = True`
CORS_ORIGIN_REGEX_WHITELIST = [
    'http://localhost:3030',
]

more details: https://github.com/ottoyiu/django-cors-headers/#configuration

read the official documentation can resolve almost all problem

Is there a way to list open transactions on SQL Server 2000 database?

You can get all the information of active transaction by the help of below query

SELECT
trans.session_id AS [SESSION ID],
ESes.host_name AS [HOST NAME],login_name AS [Login NAME],
trans.transaction_id AS [TRANSACTION ID],
tas.name AS [TRANSACTION NAME],tas.transaction_begin_time AS [TRANSACTION 
BEGIN TIME],
tds.database_id AS [DATABASE ID],DBs.name AS [DATABASE NAME]
FROM sys.dm_tran_active_transactions tas
JOIN sys.dm_tran_session_transactions trans
ON (trans.transaction_id=tas.transaction_id)
LEFT OUTER JOIN sys.dm_tran_database_transactions tds
ON (tas.transaction_id = tds.transaction_id )
LEFT OUTER JOIN sys.databases AS DBs
ON tds.database_id = DBs.database_id
LEFT OUTER JOIN sys.dm_exec_sessions AS ESes
ON trans.session_id = ESes.session_id
WHERE ESes.session_id IS NOT NULL

and it will give below similar result enter image description here

and you close that transaction by the help below KILL query by refering session id

KILL 77

How to add action listener that listens to multiple buttons

First, exend JFrame properly with a super() and a constructor then add actionlisteners to the frame and add the buttons.

import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JFrame;


public class Calc extends JFrame implements ActionListener {
    JButton button1 = new JButton("1");
    JButton button2 = new JButton("2");

    public Calc()
    {
         setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
         setSize(100, 100);
         button1.addActionListener(this);
         button2.addActionListener(this);
         calcFrame.add(button1);
         calcFrame.add(button2);
    }
    public void actionPerformed(ActionEvent e)
    {
        Object source = e.getSource();
        if(source == button1)
        {
            \\button1 code here
        } else if(source == button2)
        {
            \\button2 code here
        }
    } 
    public static void main(String[] args)
    {

        JFrame calcFrame = new JFrame();
        calcFrame.setVisible(true);
    }
}

Change the color of glyphicons to blue in some- but not at all places using Bootstrap 2

Simply apply Twitter Bootstrap text-success class on Glyphicon:

<span class="glyphicon glyphicon-play text-success">????? ??????</span>

enter image description here

Full list of available colors: Bootstrap Documentation: Helper classes
(Blue is present also)

Javascript + Regex = Nothing to repeat error?

for example I faced this in express node.js when trying to create route for paths not starting with /internal

app.get(`\/(?!internal).*`, (req, res)=>{

and after long trying it just worked when passing it as a RegExp Object using new RegExp()

app.get(new RegExp("\/(?!internal).*"), (req, res)=>{

this may help if you are getting this common issue in routing

Using two values for one switch case statement

With the integration of JEP 325: Switch Expressions (Preview) in JDK-12 early access builds, one can now make use of the new form of the switch label as :-

case text1, text4 -> {
     //blah
} 

or to rephrase the demo from one of the answers, something like :-

public class RephraseDemo {

    public static void main(String[] args) {
        int month = 9;
        int year = 2018;
        int numDays = 0;

        switch (month) {
            case 1, 3, 5, 7, 8, 10, 12 ->{
                numDays = 31;
            }
            case 4, 6, 9, 11 ->{
                numDays = 30;
            }
            case 2 ->{
                if (((year % 4 == 0) &&
                        !(year % 100 == 0))
                        || (year % 400 == 0))
                    numDays = 29;
                else
                    numDays = 28;
            }
            default ->{
                System.out.println("Invalid month.");

            }
        }
        System.out.println("Number of Days = " + numDays);
    }
}

Here is how you can give it a try - Compile a JDK12 preview feature with Maven

How to pass a value from one Activity to another in Android?

Its simple If you are passing String X from A to B.
A--> B

In Activity A
1) Create Intent
2) Put data in intent using putExtra method of intent
3) Start activity

Intent i = new Intent(A.this, B.class);
i.putExtra("MY_kEY",X);

In Activity B
inside onCreate method
1) Get intent object
2) Get stored value using key(MY_KEY)

Intent intent = getIntent();
String result = intent.getStringExtra("MY_KEY");

This is the standard way to send data from A to B. you can send any data type, it could be int, boolean, ArrayList, String[]. Based on the datatype you stored in Activity as key, value pair retrieving method might differ like if you are passing int value then you will call

intent.getIntExtra("KEY");

You can even send Class objects too but for that, you have to make your class object implement the Serializable or Parceable interface.

TransactionTooLargeException

How much data you can send across size. If data exceeds a certain amount in size then you might get TransactionTooLargeException. Suppose you are trying to send bitmap across the activity and if the size exceeds certain data size then you might see this exception.

Sending private messages to user

This is pretty simple here is an example

Add your command code here like:

if (cmd === `!dm`) {
 let dUser =
  message.guild.member(message.mentions.users.first()) ||
  message.guild.members.get(args[0]);
 if (!dUser) return message.channel.send("Can't find user!");
 if (!message.member.hasPermission('ADMINISTRATOR'))
  return message.reply("You can't you that command!");
 let dMessage = args.join(' ').slice(22);
 if (dMessage.length < 1) return message.reply('You must supply a message!');

 dUser.send(`${dUser} A moderator from WP Coding Club sent you: ${dMessage}`);

 message.author.send(
  `${message.author} You have sent your message to ${dUser}`
 );
}

How to find out whether a file is at its `eof`?

Reading a file in batches of BATCH_SIZE lines (the last batch can be shorter):

BATCH_SIZE = 1000  # lines

with open('/path/to/a/file') as fin:
    eof = False
    while eof is False:
        # We use an iterator to check later if it was fully realized. This
        # is a way to know if we reached the EOF.
        # NOTE: file.tell() can't be used with iterators.
        batch_range = iter(range(BATCH_SIZE))
        acc = [line for (_, line) in zip(batch_range, fin)]

        # DO SOMETHING WITH "acc"

        # If we still have something to iterate, we have read the whole
        # file.
        if any(batch_range):
            eof = True

How to fade changing background image

This is probably what you wanted:

$('#elem').fadeTo('slow', 0.3, function()
{
    $(this).css('background-image', 'url(' + $img + ')');
}).fadeTo('slow', 1);

With a 1 second delay:

$('#elem').fadeTo('slow', 0.3, function()
{
    $(this).css('background-image', 'url(' + $img + ')');
}).delay(1000).fadeTo('slow', 1);

Swift: Display HTML data in a label or textView

Add this extension to convert your html code to a regular string:

    extension String {

        var html2AttributedString: NSAttributedString? {
            guard
                let data = dataUsingEncoding(NSUTF8StringEncoding)
            else { return nil }
            do {
                return try NSAttributedString(data: data, options: [NSDocumentTypeDocumentAttribute:NSHTMLTextDocumentType,NSCharacterEncodingDocumentAttribute:NSUTF8StringEncoding], documentAttributes: nil)
            } catch let error as NSError {
                print(error.localizedDescription)
                return  nil
            }
        }
        var html2String: String {
            return html2AttributedString?.string ?? ""
        }
}

And then you show your String inside an UITextView Or UILabel

textView.text = yourString.html2String or

label.text = yourString.html2String

Set value of textbox using JQuery

You are logging sup directly which is a string

console.log('sup')

Also you are using the wrong id

The template says #main_search but you are using #searchBar

I suppose you are trying this out

$(function() {
   var sup = $('#main_search').val('hi')
   console.log(sup);  // sup is a variable here
});

How can a Javascript object refer to values in itself?

You can also reference the obj once you are inside the function instead of this.

var obj = {
    key1: "it",
    key2: function(){return obj.key1 + " works!"}
};
alert(obj.key2());

PHP - Copy image to my server direct from URL

This SO thread will solve your problem. Solution in short:

$url = 'http://www.google.co.in/intl/en_com/images/srpr/logo1w.png';
$img = '/my/folder/my_image.gif';
file_put_contents($img, file_get_contents($url));

How can I select rows with most recent timestamp for each key value?

This can de done in a relatively elegant way using SELECT DISTINCT, as follows:

SELECT DISTINCT ON (sensorID)
sensorID, timestamp, sensorField1, sensorField2 
FROM sensorTable
ORDER BY sensorID, timestamp DESC;

The above works for PostgreSQL (some more info here) but I think also other engines. In case it's not obvious, what this does is sort the table by sensor ID and timestamp (newest to oldest), and then returns the first row (i.e. latest timestamp) for each unique sensor ID.

In my use case I have ~10M readings from ~1K sensors, so trying to join the table with itself on a timestamp-based filter is very resource-intensive; the above takes a couple of seconds.

Refused to execute script, strict MIME type checking is enabled?

In my case I had a symlink for the 404'd file and my Tomcat was not configured to allow symlinks.

I know that it is not likely to be the cause for most people, but if you are desperate, check this possibility just in case.

How to completely uninstall Visual Studio 2010?

Best way I have used is to mount the VS 2010 Image or insert the Installation disc and run the uninstall option, really works well

"A referral was returned from the server" exception when accessing AD from C#

Probably the path you supplied was not correct. Check that.

I would recomment the article Howto: (Almost) Everything In Active Directory via C# which really helped me in the past in dealing with AD.

Change auto increment starting number?

You can also do it using phpmyadmin. Just select the table than go to actions. And change the Auto increment below table options. Don't forget to click on start Auto increment in phpmyadmin

How to extend / inherit components?

Now that TypeScript 2.2 supports Mixins through Class expressions we have a much better way to express Mixins on Components. Mind you that you can also use Component inheritance since angular 2.3 (discussion) or a custom decorator as discussed in other answers here. However, I think Mixins have some properties that make them preferable for reusing behavior across components:

  • Mixins compose more flexibly, i.e. you can mix and match Mixins on existing components or combine Mixins to form new Components
  • Mixin composition remains easy to understand thanks to its obvious linearization to a class inheritance hierarchy
  • You can more easily avoid issues with decorators and annotations that plague component inheritance (discussion)

I strongly suggest you read the TypeScript 2.2 announcement above to understand how Mixins work. The linked discussions in angular GitHub issues provide additional detail.

You'll need these types:

export type Constructor<T> = new (...args: any[]) => T;

export class MixinRoot {
}

And then you can declare a Mixin like this Destroyable mixin that helps components keep track of subscriptions that need to be disposed in ngOnDestroy:

export function Destroyable<T extends Constructor<{}>>(Base: T) {
  return class Mixin extends Base implements OnDestroy {
    private readonly subscriptions: Subscription[] = [];

    protected registerSubscription(sub: Subscription) {
      this.subscriptions.push(sub);
    }

    public ngOnDestroy() {
      this.subscriptions.forEach(x => x.unsubscribe());
      this.subscriptions.length = 0; // release memory
    }
  };
}

To mixin Destroyable into a Component, you declare your component like this:

export class DashboardComponent extends Destroyable(MixinRoot) 
    implements OnInit, OnDestroy { ... }

Note that MixinRoot is only necessary when you want to extend a Mixin composition. You can easily extend multiple mixins e.g. A extends B(C(D)). This is the obvious linearization of mixins I was talking about above, e.g. you're effectively composing an inheritnace hierarchy A -> B -> C -> D.

In other cases, e.g. when you want to compose Mixins on an existing class, you can apply the Mixin like so:

const MyClassWithMixin = MyMixin(MyClass);

However, I found the first way works best for Components and Directives, as these also need to be decorated with @Component or @Directive anyway.

How to stop/cancel 'git log' command in terminal?

You can hit the key q (for quit) and it should take you to the prompt.

Please see this link.

How to make a <div> or <a href="#"> to align center

You can use the code below:

a {
display: block;
width: 113px;
margin: auto; 
}

By setting, in my case, the link to display:block, it is easier to position the link.
This works the same when you use a <div> tag/class.
You can pick any width you want.

Adding additional data to select options using jQuery

I made two examples from what I think your question might be:

http://jsfiddle.net/grdn4/

Check this out for storing additional values. It uses data attributes to store the other value:

http://jsfiddle.net/27qJP/1/

Delete rows with foreign key in PostgreSQL

It means that in table kontakty you have a row referencing the row in osoby you want to delete. You have do delete that row first or set a cascade delete on the relation between tables.

Powodzenia!

Visual Studio: How to break on handled exceptions?

From Visual Studio 2015 and onward, you need to go to the "Exception Settings" dialog (Ctrl+Alt+E) and check off the "Common Language Runtime Exceptions" (or a specific one you want i.e. ArgumentNullException) to make it break on handled exceptions.

Step 1 Step 1 Step 2 Step 2

What is the HTML tabindex attribute?

The HTML tabindex atribute is responsible for indicating if an element is reachable by keyboard navigation. When the user presses the Tab key the focus is shifted from one element to another. By using the tabindex atribute, the tab order flow is shifted.

Why should I use IHttpActionResult instead of HttpResponseMessage?

The Web API basically return 4 type of object: void, HttpResponseMessage, IHttpActionResult, and other strong types. The first version of the Web API returns HttpResponseMessage which is pretty straight forward HTTP response message.

The IHttpActionResult was introduced by WebAPI 2 which is a kind of wrap of HttpResponseMessage. It contains the ExecuteAsync() method to create an HttpResponseMessage. It simplifies unit testing of your controller.

Other return type are kind of strong typed classes serialized by the Web API using a media formatter into the response body. The drawback was you cannot directly return an error code such as a 404. All you can do is throwing an HttpResponseException error.

nuget 'packages' element is not declared warning

You will see it only when the file is open. When you'll close the file in Visual Studio the warnings goes away

http://nuget.codeplex.com/discussions/261638

What is the use of ByteBuffer in Java?

Here is a great article explaining ByteBuffer benefits. Following are the key points in the article:

  • First advantage of a ByteBuffer irrespective of whether it is direct or indirect is efficient random access of structured binary data (e.g., low-level IO as stated in one of the answers). Prior to Java 1.4, to read such data one could use a DataInputStream, but without random access.

Following are benefits specifically for direct ByteBuffer/MappedByteBuffer. Note that direct buffers are created outside of heap:

  1. Unaffected by gc cycles: Direct buffers won't be moved during garbage collection cycles as they reside outside of heap. TerraCota's BigMemory caching technology seems to rely heavily on this advantage. If they were on heap, it would slow down gc pause times.

  2. Performance boost: In stream IO, read calls would entail system calls, which require a context-switch between user to kernel mode and vice versa, which would be costly especially if file is being accessed constantly. However, with memory-mapping this context-switching is reduced as data is more likely to be found in memory (MappedByteBuffer). If data is available in memory, it is accessed directly without invoking OS, i.e., no context-switching.

Note that MappedByteBuffers are very useful especially if the files are big and few groups of blocks are accessed more frequently.

  1. Page sharing: Memory mapped files can be shared between processes as they are allocated in process's virtual memory space and can be shared across processes.

Get controller and action name from within controller?

Use given lines in OnActionExecuting for Action and Controller name.

string actionName = this.ControllerContext.RouteData.Values["action"].ToString();

string controllerName = this.ControllerContext.RouteData.Values["controller"].ToString();