Programs & Examples On #Evaluate

Evaluating string "3*(4+2)" yield int 18

static double Evaluate(string expression) { 
  var loDataTable = new DataTable(); 
  var loDataColumn = new DataColumn("Eval", typeof (double), expression); 
  loDataTable.Columns.Add(loDataColumn); 
  loDataTable.Rows.Add(0); 
  return (double) (loDataTable.Rows[0]["Eval"]); 
} 

Explanation of how it works:

First, we make a table in the part var loDataTable = new DataTable();, just like in a Data Base Engine (MS SQL for example).

Then, a column, with some specific parameters (var loDataColumn = new DataColumn("Eval", typeof (double), expression);).

The "Eval" parameter is the name of the column (ColumnName attribute).

typeof (double) is the type of data to be stored in the column, which is equal to put System.Type.GetType("System.Double"); instead.

expression is the string that the Evaluate method receives, and is stored in the attribute Expression of the column. This attribute is for a really specific purpose (obvious), which is that every row that's put on the column will be fullfilled with the "Expression", and it accepts practically wathever can be put in a SQL Query. Refer to http://msdn.microsoft.com/en-us/library/system.data.datacolumn.expression(v=vs.100).aspx to know what can be put in the Expression attribute, and how it's evaluated.

Then, loDataTable.Columns.Add(loDataColumn); adds the column loDataColumn to the loDataTable table.

Then, a row is added to the table with a personalized column with a Expression attribute, done via loDataTable.Rows.Add(0);. When we add this row, the cell of the column "Eval" of the table loDataTable is fullfilled automatically with its "Expression" attribute, and, if it has operators and SQL Queries, etc, it's evaluated and then stored to the cell, so, here happens the "magic", the string with operators is evaluated and stored to a cell...

Finally, just return the value stored to the cell of the column "Eval" in row 0 (it's an index, starts counting from zero), and making a conversion to a double with return (double) (loDataTable.Rows[0]["Eval"]);.

And that's all... job done!

And here a code eaiser to understand, which does the same... It's not inside a method, and it's explained too.

DataTable MyTable = new DataTable();
DataColumn MyColumn = new DataColumn();
MyColumn.ColumnName = "MyColumn";
MyColumn.Expression = "5+5/5"
MyColumn.DataType = typeof(double);
MyTable.Columns.Add(MyColumn);
DataRow MyRow = MyTable.NewRow();
MyTable.Rows.Add(MyRow);
return (double)(MyTable.Rows[0]["MyColumn"]);

First, create the table with DataTable MyTable = new DataTable();

Then, a column with DataColumn MyColumn = new DataColumn();

Next, we put a name to the column. This so we can search into it's contents when it's stored to the table. Done via MyColumn.ColumnName = "MyColumn";

Then, the Expression, here we can put a variable of type string, in this case there's a predefined string "5+5/5", which result is 6.

The type of data to be stored to the column MyColumn.DataType = typeof(double);

Add the column to the table... MyTable.Columns.Add(MyColumn);

Make a row to be inserted to the table, which copies the table structure DataRow MyRow = MyTable.NewRow();

Add the row to the table with MyTable.Rows.Add(MyRow);

And return the value of the cell in row 0 of the column MyColumn of the table MyTable with return (double)(MyTable.Rows[0]["MyColumn"]);

Lesson done!!!

How to turn a string formula into a "real" formula

I prefer the VBA-solution for professional solutions.

With the replace-procedure part in the question search and replace WHOLE WORDS ONLY, I use the following VBA-procedure:

''
' Evaluate Formula-Text in Excel
'
Function wm_Eval(myFormula As String, ParamArray variablesAndValues() As Variant) As Variant
    Dim i As Long

    '
    ' replace strings by values
    '
    For i = LBound(variablesAndValues) To UBound(variablesAndValues) Step 2
        myFormula = RegExpReplaceWord(myFormula, variablesAndValues(i), variablesAndValues(i + 1))
    Next

    '
    ' internationalisation
    '
    myFormula = Replace(myFormula, Application.ThousandsSeparator, "")
    myFormula = Replace(myFormula, Application.DecimalSeparator, ".")
    myFormula = Replace(myFormula, Application.International(xlListSeparator), ",")

    '
    ' return value
    '
    wm_Eval = Application.Evaluate(myFormula)
End Function


''
' Replace Whole Word
'
' Purpose   : replace [strFind] with [strReplace] in [strSource]
' Comment   : [strFind] can be plain text or a regexp pattern;
'             all occurences of [strFind] are replaced
Public Function RegExpReplaceWord(ByVal strSource As String, _
ByVal strFind As String, _
ByVal strReplace As String) As String

    ' early binding requires reference to Microsoft VBScript
    ' Regular Expressions:
    ' with late binding, no reference needed:
    Dim re As Object
    Set re = CreateObject("VBScript.RegExp")

    re.Global = True
    're.IgnoreCase = True ' <-- case insensitve
    re.Pattern = "\b" & strFind & "\b"
    RegExpReplaceWord = re.Replace(strSource, strReplace)
    Set re = Nothing
End Function

Usage of the procedure in an excel sheet looks like:

usage in excel-sheet

Where value in column containing comma delimited values

Although the tricky solution @tbaxter120 advised is good but I use this function and work like a charm, pString is a delimited string and pDelimiter is a delimiter character:

SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO

ALTER FUNCTION [dbo].[DelimitedSplit]
--===== Define I/O parameters
        (@pString NVARCHAR(MAX), @pDelimiter CHAR(1))
RETURNS TABLE WITH SCHEMABINDING AS
 RETURN
--===== "Inline" CTE Driven "Tally Table" produces values from 0 up to 10,000...
     -- enough to cover VARCHAR(8000)
  WITH E1(N) AS (
                 SELECT 1 UNION ALL SELECT 1 UNION ALL SELECT 1 UNION ALL 
                 SELECT 1 UNION ALL SELECT 1 UNION ALL SELECT 1 UNION ALL 
                 SELECT 1 UNION ALL SELECT 1 UNION ALL SELECT 1 UNION ALL SELECT 1
                ),                          --10E+1 or 10 rows
       E2(N) AS (SELECT 1 FROM E1 a, E1 b), --10E+2 or 100 rows
       E4(N) AS (SELECT 1 FROM E2 a, E2 b), --10E+4 or 10,000 rows max
 cteTally(N) AS (--==== This provides the "base" CTE and limits the number of rows right up front
                     -- for both a performance gain and prevention of accidental "overruns"
                 SELECT TOP (ISNULL(DATALENGTH(@pString),0)) ROW_NUMBER() OVER (ORDER BY (SELECT NULL)) FROM E4
                ),
cteStart(N1) AS (--==== This returns N+1 (starting position of each "element" just once for each delimiter)
                 SELECT 1 UNION ALL -- does away with 0 base CTE, and the OR condition in one go!
                 SELECT t.N+1 FROM cteTally t WHERE SUBSTRING(@pString,t.N,1) = @pDelimiter
                ),
cteLen(N1,L1) AS(--==== Return start and length (for use in substring)
                 SELECT s.N1,
                        ---ISNULL(NULLIF(CHARINDEX(@pDelimiter,@pString,s.N1),0)-s.N1,8000)
                        ISNULL(NULLIF(CHARINDEX(@pDelimiter,@pString,s.N1),0)-s.N1,50000)
                   FROM cteStart s
                )
--===== Do the actual split. The ISNULL/NULLIF combo handles the length for the final element when no delimiter is found.
 SELECT ItemNumber = ROW_NUMBER() OVER(ORDER BY l.N1),
        Item       = SUBSTRING(@pString, l.N1, l.L1)
   FROM cteLen l

;

Then for example you can call it in where clause as below:

WHERE [fieldname] IN (SELECT LTRIM(RTRIM(Item)) FROM [dbo].[DelimitedSplit]('2,5,11', ','))

Hope this help.

Reading text files using read.table

From ?read.table: The number of data columns is determined by looking at the first five lines of input (or the whole file if it has less than five lines), or from the length of col.names if it is specified and is longer. This could conceivably be wrong if fill or blank.lines.skip are true, so specify col.names if necessary.

So, perhaps your data file isn't clean. Being more specific will help the data import:

d = read.table("foobar.txt", 
               sep="\t", 
               col.names=c("id", "name"), 
               fill=FALSE, 
               strip.white=TRUE)

will specify exact columns and fill=FALSE will force a two column data frame.

How to define a default value for "input type=text" without using attribute 'value'?

You can use Javascript.

For example, using jQuery:

$(':text').val('1000');

However, this won't be any different from using the value attribute.

Excel - match data from one range to another and get the value from the cell to the right of the matched data

Thanks a bundle, guys. You are great.

I used Chuff's answer and modified it a little to do what I wanted.

I have 2 worksheets in the same workbook.

On 1st worksheet I have a list of SMS in 3 columns: phone number, date & time, message

Then I inserted a new blank column next to the phone number

On worksheet 2 I have two columns: phone number, name of person

Used the formula to check the cell on the left, and match against the range in worksheet 2, pick the name corresponding to the number and input it into the blank cell in worksheet 1.

Then just copy the formula down the whole column until last sms It worked beautifully.

=VLOOKUP(A3,Sheet2!$A$1:$B$31,2,0)

Fatal error: Call to a member function query() on null

First, you declared $db outside the function. If you want to use it inside the function, you should put this at the begining of your function code:

global $db;

And I guess, when you wrote:

if($result->num_rows){
        return (mysqli_result($query, 0) == 1) ? true : false;

what you really wanted was:

if ($result->num_rows==1) { return true; } else { return false; }

Static array vs. dynamic array in C++

You could have a pseudo dynamic array where the size is set by the user at runtime, but then is fixed after that.

int size;
cin >> size;
int dynamicArray[size];

Add column in dataframe from list

First let's create the dataframe you had, I'll ignore columns B and C as they are not relevant.

df = pd.DataFrame({'A': [0, 4, 5, 6, 7, 7, 6,5]})

And the mapping that you desire:

mapping = dict(enumerate([2,5,6,8,12,16,26,32]))

df['D'] = df['A'].map(mapping)

Done!

print df

Output:

   A   D
0  0   2
1  4  12
2  5  16
3  6  26
4  7  32
5  7  32
6  6  26
7  5  16

How to execute a JavaScript function when I have its name as a string

Surprised to see no mention of setTimeout.

To run a function without arguments:

var functionWithoutArguments = function(){
    console.log("Executing functionWithoutArguments");
}
setTimeout("functionWithoutArguments()", 0);

To run function with arguments:

var functionWithArguments = function(arg1, arg2) {
    console.log("Executing functionWithArguments", arg1, arg2);
}
setTimeout("functionWithArguments(10, 20)");

To run deeply namespaced function:

var _very = {
    _deeply: {
        _defined: {
            _function: function(num1, num2) {
                console.log("Execution _very _deeply _defined _function : ", num1, num2);
            }
        }
    }
}
setTimeout("_very._deeply._defined._function(40,50)", 0);

Drop unused factor levels in a subsetted data frame

Since R version 2.12, there's a droplevels() function.

levels(droplevels(subdf$letters))

Convert a list to a dictionary in Python

May not be the most pythonic, but

>>> b = {}
>>> for i in range(0, len(a), 2):
        b[a[i]] = a[i+1]

Async await in linq select

I have the same problem as @KTCheek in that I need it to execute sequentially. However I figured I would try using IAsyncEnumerable (introduced in .NET Core 3) and await foreach (introduced in C# 8). Here's what I have come up with:

public static class IEnumerableExtensions {
    public static async IAsyncEnumerable<TResult> SelectAsync<TSource, TResult>(this IEnumerable<TSource> source, Func<TSource, Task<TResult>> selector) {
        foreach (var item in source) {
            yield return await selector(item);
        }
    }
}

public static class IAsyncEnumerableExtensions {
    public static async Task<List<TSource>> ToListAsync<TSource>(this IAsyncEnumerable<TSource> source) {
        var list = new List<TSource>();

        await foreach (var item in source) {
            list.Add(item);
        }

        return list;
    }
}

This can be consumed by saying:

var inputs = await events.SelectAsync(ev => ProcessEventAsync(ev)).ToListAsync();

Update: Alternatively you can add a reference to "System.Linq.Async" and then you can say:

var inputs = await events
    .ToAsyncEnumerable()
    .SelectAwait(async ev => await ProcessEventAsync(ev))
    .ToListAsync();

How do I perform query filtering in django templates

I run into this problem on a regular basis and often use the "add a method" solution. However, there are definitely cases where "add a method" or "compute it in the view" don't work (or don't work well). E.g. when you are caching template fragments and need some non-trivial DB computation to produce it. You don't want to do the DB work unless you need to, but you won't know if you need to until you are deep in the template logic.

Some other possible solutions:

  1. Use the {% expr <expression> as <var_name> %} template tag found at http://www.djangosnippets.org/snippets/9/ The expression is any legal Python expression with your template's Context as your local scope.

  2. Change your template processor. Jinja2 (http://jinja.pocoo.org/2/) has syntax that is almost identical to the Django template language, but with full Python power available. It's also faster. You can do this wholesale, or you might limit its use to templates that you are working on, but use Django's "safer" templates for designer-maintained pages.

Set the space between Elements in Row Flutter

Removing Space-:

new Row(
            mainAxisAlignment: MainAxisAlignment.center,
            children: <Widget>[
              GestureDetector(
                child: new Text('Don\'t have an account?',
                    style: new TextStyle(color: Color(0xFF2E3233))),
                onTap: () {},
              ),
              GestureDetector(
                onTap: (){},
                  child: new Text(
                'Register.',
                style: new TextStyle(
                    color: Color(0xFF84A2AF), fontWeight: FontWeight.bold),
              ))
            ],
          ),

OR

GestureDetector(
            onTap: (){},
            child: new Row(
              mainAxisAlignment: MainAxisAlignment.center,
              children: <Widget>[
                new Text('Don\'t have an account?',
                    style: new TextStyle(color: Color(0xFF2E3233))),
                new Text(
                  'Register.',
                  style: new TextStyle(
                  color: Color(0xFF84A2AF), fontWeight: FontWeight.bold),
                )
              ],
            ),
          ),

AngularJs: Reload page

You can use the reload method of the $route service. Inject $route in your controller and then create a method reloadRoute on your $scope.

$scope.reloadRoute = function() {
   $route.reload();
}

Then you can use it on the link like this:

<a ng-click="reloadRoute()" class="navbar-brand" title="home"  data-translate>PORTAL_NAME</a>

This method will cause the current route to reload. If you however want to perform a full refresh, you could inject $window and use that:

$scope.reloadRoute = function() {
   $window.location.reload();
}


Later edit (ui-router):

As mentioned by JamesEddyEdwards and Dunc in their answers, if you are using angular-ui/ui-router you can use the following method to reload the current state / route. Just inject $state instead of $route and then you have:

$scope.reloadRoute = function() {
    $state.reload();
};

'too many values to unpack', iterating over a dict. key=>string, value=>list

In Python3 iteritems() is no longer supported

Use .items

for field, possible_values in fields.items():
    print(field, possible_values)

How to display databases in Oracle 11g using SQL*Plus

I am not clearly about it but typically one server has one database (with many users), if you create many databases mean that you create many instances, listeners, ... as well. So you can check your LISTENER to identify it.

In my testing I created 2 databases (dbtest and dbtest_1) so when I check my LISTENER status it appeared like this:

lsnrctl status

....

STATUS of the LISTENER

.....

(DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=10.10.20.20)(PORT=1521)))

Services Summary...

Service "dbtest" has 1 instance(s).

Instance "dbtest", status READY, has 1 handler(s) for this service...

Service "dbtest1XDB" has 1 instance(s).

Instance "dbtest1", status READY, has 1 handler(s) for this service...

Service "dbtest_1" has 1 instance(s).

Instance "dbtest1", status READY, has 1 handler(s) for this service... The command completed successfully

Pytorch tensor to numpy array

This worked for me:

np_arr = torch_tensor.cpu().detach().numpy()

Math functions in AngularJS bindings

Angular Typescript example using a pipe.

math.pipe.ts

import { Pipe, PipeTransform } from '@angular/core';

@Pipe({
  name: 'math',
})

export class MathPipe implements PipeTransform {

  transform(value: number, args: any = null):any {
      if(value) {
        return Math[args](value);
      }
      return 0;
  }
}

Add to @NgModule declarations

@NgModule({
  declarations: [
    MathPipe,

then use in your template like so:

{{(100*count/total) | math:'round'}}

How do I suspend painting for a control and its children?

Or just use Control.SuspendLayout() and Control.ResumeLayout().

Want to make Font Awesome icons clickable

Please use Like below.
<a style="cursor: pointer" **(click)="yourFunctionComponent()"** >
<i class="fa fa-dribbble fa-4x"></i>
 </a>

The above can be used so that the fa icon will be shown and also on the click function you could write your logic.

Node.js: for each … in not working

There's no for each in in the version of ECMAScript supported by Node.js, only supported by firefox currently.

The important thing to note is that JavaScript versions are only relevant to Gecko (Firefox's engine) and Rhino (which is always a few versions behind). Node uses V8 which follows ECMAScript specifications

How to append something to an array?

There are a couple of ways to append an array in JavaScript:

1) The push() method adds one or more elements to the end of an array and returns the new length of the array.

var a = [1, 2, 3];
a.push(4, 5);
console.log(a);

Output:

[1, 2, 3, 4, 5]

2) The unshift() method adds one or more elements to the beginning of an array and returns the new length of the array:

var a = [1, 2, 3];
a.unshift(4, 5);
console.log(a); 

Output:

[4, 5, 1, 2, 3]

3) The concat() method is used to merge two or more arrays. This method does not change the existing arrays, but instead returns a new array.

var arr1 = ["a", "b", "c"];
var arr2 = ["d", "e", "f"];
var arr3 = arr1.concat(arr2);
console.log(arr3);

Output:

[ "a", "b", "c", "d", "e", "f" ]

4) You can use the array's .length property to add an element to the end of the array:

var ar = ['one', 'two', 'three'];
ar[ar.length] = 'four';
console.log( ar ); 

Output:

 ["one", "two", "three", "four"]

5) The splice() method changes the content of an array by removing existing elements and/or adding new elements:

var myFish = ["angel", "clown", "mandarin", "surgeon"];
myFish.splice(4, 0, "nemo");
//array.splice(start, deleteCount, item1, item2, ...)
console.log(myFish);

Output:

["angel", "clown", "mandarin", "surgeon","nemo"]

6) You can also add a new element to an array simply by specifying a new index and assigning a value:

var ar = ['one', 'two', 'three'];
ar[3] = 'four'; // add new element to ar
console.log(ar);

Output:

["one", "two","three","four"]

jQuery animated number counter from zero to value

You can do it with animate function in jQuery.

$({ countNum: $('.code').html() }).animate({ countNum: 4000 }, {
    duration: 8000,
    easing: 'linear',
    step: function () {
        $('.yourelement').html(Math.floor(this.countNum));
    },
    complete: function () {
        $('.code').html(this.countNum);
        //alert('finished');
   }
});

Demo

dyld: Library not loaded: /usr/local/lib/libpng16.16.dylib with anything php related

I also had this problem, and none of the solutions in this thread worked for me. As it turns out, the problem was that I had this line in ~/.bash_profile:

alias php="/usr/local/php/bin/php"

And, as it turns out, /usr/local/php was just a symlink to /usr/local/Cellar/php54/5.4.24/. So when I invoked php -i I was still invoking php54. I just deleted this line from my bash profile, and then php worked.

For some reason, even though php55 was now running, the php.ini file from php54 was still loaded, and I received this warning every time I invoked php:

PHP Warning:  PHP Startup: Unable to load dynamic library '/usr/local/Cellar/php54/5.4.38/lib/php/extensions/no-debug-non-zts-20100525/memcached.so' - dlopen(/usr/local/Cellar/php54/5.4.38/lib/php/extensions/no-debug-non-zts-20100525/memcached.so, 9): image not found in Unknown on line 0

To fix this, I just added the following line to my bash profile:

export PHPRC=/usr/local/etc/php/5.5/php.ini

And then everything worked as normal!

Setting a property by reflection with a string value

You're probably looking for the Convert.ChangeType method. For example:

Ship ship = new Ship();
string value = "5.5";
PropertyInfo propertyInfo = ship.GetType().GetProperty("Latitude");
propertyInfo.SetValue(ship, Convert.ChangeType(value, propertyInfo.PropertyType), null);

Using the passwd command from within a shell script

For those who need to 'run as root' remotely through a script logging into a user account in the sudoers file, I found an evil horrible hack, that is no doubt very insecure:

sshpass -p 'userpass' ssh -T -p port user@server << EOSSH
sudo -S su - << RROOT
userpass
echo ""
echo "*** Got Root ***"
echo ""
#[root commands go here]
useradd -m newuser
echo "newuser:newpass" | chpasswd
RROOT
EOSSH

Send POST data via raw json with postman

Just check JSON option from the drop down next to binary; when you click raw. This should do

skill synon pass json to postman

mysql: get record count between two date-time

select * from yourtable where created < now() and created > '2011-04-25 04:00:00'

Unique on a dataframe with only selected columns

Here are a couple dplyr options that keep non-duplicate rows based on columns id and id2:

library(dplyr)                                        
df %>% distinct(id, id2, .keep_all = TRUE)
df %>% group_by(id, id2) %>% filter(row_number() == 1)
df %>% group_by(id, id2) %>% slice(1)

What's the idiomatic syntax for prepending to a short python list?

If you can go the functional way, the following is pretty clear

new_list = [x] + your_list

Of course you haven't inserted x into your_list, rather you have created a new list with x preprended to it.

Regular Expressions: Search in list

You can create an iterator in Python 3.x or a list in Python 2.x by using:

filter(r.match, list)

To convert the Python 3.x iterator to a list, simply cast it; list(filter(..)).

Modifying a file inside a jar

Not sure if this help, but you can edit without extracting:

  1. Open the jar file from vi editor
  2. Select the file you want to edit from the list
  3. Press enter to open the file do the changers and save it pretty simple

Check the blog post for more details http://vinurip.blogspot.com/2015/04/how-to-edit-contents-of-jar-file-on-mac.html

'and' (boolean) vs '&' (bitwise) - Why difference in behavior with lists vs numpy arrays?

Operations with a Python list operate on the list. list1 and list2 will check if list1 is empty, and return list1 if it is, and list2 if it isn't. list1 + list2 will append list2 to list1, so you get a new list with len(list1) + len(list2) elements.

Operators that only make sense when applied element-wise, such as &, raise a TypeError, as element-wise operations aren't supported without looping through the elements.

Numpy arrays support element-wise operations. array1 & array2 will calculate the bitwise or for each corresponding element in array1 and array2. array1 + array2 will calculate the sum for each corresponding element in array1 and array2.

This does not work for and and or.

array1 and array2 is essentially a short-hand for the following code:

if bool(array1):
    return array2
else:
    return array1

For this you need a good definition of bool(array1). For global operations like used on Python lists, the definition is that bool(list) == True if list is not empty, and False if it is empty. For numpy's element-wise operations, there is some disambiguity whether to check if any element evaluates to True, or all elements evaluate to True. Because both are arguably correct, numpy doesn't guess and raises a ValueError when bool() is (indirectly) called on an array.

HashMap and int as key

If you code in Android, there is SparseArray, mapping integer to object.

How does Python manage int and long?

Python 2.7.9 auto promotes numbers. For a case where one is unsure to use int() or long().

>>> a = int("123")
>>> type(a)
<type 'int'>
>>> a = int("111111111111111111111111111111111111111111111111111")
>>> type(a)
<type 'long'>

Import CSV file into SQL Server

Because they do not use the SQL import wizard, the steps would be as follows:

enter image description here

  1. Right click on the database in the option tasks to import data,

  2. Once the wizard is open, we select the type of data to be implied. In this case it would be the

Flat file source

We select the CSV file, you can configure the data type of the tables in the CSV, but it is best to bring it from the CSV.

  1. Click Next and select in the last option that is

SQL client

Depending on our type of authentication we select it, once this is done, a very important option comes.

  1. We can define the id of the table in the CSV (it is recommended that the columns of the CSV should be called the same as the fields in the table). In the option Edit Mappings we can see the preview of each table with the column of the spreadsheet, if we want the wizard to insert the id by default we leave the option unchecked.

Enable id insert

(usually not starting from 1), instead if we have a column with the id in the CSV we select the enable id insert, the next step is to end the wizard, we can review the changes here.

On the other hand, in the following window may come alerts, or warnings the ideal is to ignore this, only if they leave error is necessary to pay attention.

This link has images.

Using IF ELSE statement based on Count to execute different Insert statements

Depending on your needs, here are a couple of ways:

IF EXISTS (SELECT * FROM TABLE WHERE COLUMN = 'SOME VALUE')
    --INSERT SOMETHING
ELSE
    --INSERT SOMETHING ELSE

Or a bit longer

DECLARE @retVal int

SELECT @retVal = COUNT(*) 
FROM TABLE
WHERE COLUMN = 'Some Value'

IF (@retVal > 0)
BEGIN
    --INSERT SOMETHING
END
ELSE
BEGIN
    --INSERT SOMETHING ELSE
END 

How to move text up using CSS when nothing is working

you can try

position: relative;
bottom: 20px;

but I don't see a problem on my browser (Google Chrome)

How do you Make A Repeat-Until Loop in C++?

For an example if you want to have a loop that stopped when it has counted all of the people in a group. We will consider the value X to be equal to the number of the people in the group, and the counter will be used to count all of the people in the group. To write the

while(!condition)

the code will be:

int x = people;

int counter = 0;

while(x != counter)

{

counter++;

}

return 0;

Use bash to find first folder name that contains a string

You can use the -quit option of find:

find <dir> -maxdepth 1 -type d -name '*foo*' -print -quit

How can I find last row that contains data in a specific column?

Public Function LastData(rCol As Range) As Range    
    Set LastData = rCol.Find("*", rCol.Cells(1), , , , xlPrevious)    
End Function

Usage: ?lastdata(activecell.EntireColumn).Address

How do I unbind "hover" in jQuery?

$(this).unbind('mouseenter').unbind('mouseleave')

or more succinctly (thanks @Chad Grant):

$(this).unbind('mouseenter mouseleave')

How do you enable auto-complete functionality in Visual Studio C++ express edition?

All the answers were missing Ctrl-J (which enables and disables autocomplete).

How to initialize all members of an array to the same value?

Here is another way:

static void
unhandled_interrupt(struct trap_frame *frame, int irq, void *arg)
{
    //this code intentionally left blank
}

static struct irqtbl_s vector_tbl[XCHAL_NUM_INTERRUPTS] = {
    [0 ... XCHAL_NUM_INTERRUPTS-1] {unhandled_interrupt, NULL},
};

See:

C-Extensions

Designated inits

Then ask the question: When can one use C extensions?

The code sample above is in an embedded system and will never see the light from another compiler.

What does -Xmn jvm option stands for

From GC Performance Tuning training documents of Oracle:

-Xmn[size]: Size of young generation heap space.

Applications with emphasis on performance tend to use -Xmn to size the young generation, because it combines the use of -XX:MaxNewSize and -XX:NewSize and almost always explicitly sets -XX:PermSize and -XX:MaxPermSize to the same value.

In short, it sets the NewSize and MaxNewSize values of New generation to the same value.

How to find rows in one table that have no corresponding row in another table

You have to check every ID in tableA against every ID in tableB. A fully featured RDBMS (such as Oracle) would be able to optimize that into an INDEX FULL FAST SCAN and not touch the table at all. I don't know whether H2's optimizer is as smart as that.

H2 does support the MINUS syntax so you should try this

select id from tableA
minus
select id from tableB
order by id desc

That may perform faster; it is certainly worth benchmarking.

retrieve data from db and display it in table in php .. see this code whats wrong with it?

Here is the solution total html with php and database connections

   <!doctype html>
    <html lang="en">
    <head>
      <meta charset="UTF-8">
      <title>database connections</title>
    </head>
    <body>
      <?php
      $username = "database-username";
      $password = "database-password";
      $host = "localhost";

      $connector = mysql_connect($host,$username,$password)
          or die("Unable to connect");
        echo "Connections are made successfully::";
      $selected = mysql_select_db("test_db", $connector)
        or die("Unable to connect");

      //execute the SQL query and return records
      $result = mysql_query("SELECT * FROM table_one ");
      ?>
      <table border="2" style= "background-color: #84ed86; color: #761a9b; margin: 0 auto;" >
      <thead>
        <tr>
          <th>Employee_id</th>
          <th>Employee_Name</th>
          <th>Employee_dob</th>
          <th>Employee_Adress</th>
          <th>Employee_dept</th>
          <td>Employee_salary</td>
        </tr>
      </thead>
      <tbody>
        <?php
          while( $row = mysql_fetch_assoc( $result ) ){
            echo
            "<tr>
              <td>{$row\['employee_id'\]}</td>
              <td>{$row\['employee_name'\]}</td>
              <td>{$row\['employee_dob'\]}</td>
              <td>{$row\['employee_addr'\]}</td>
              <td>{$row\['employee_dept'\]}</td>
              <td>{$row\['employee_sal'\]}</td> 
            </tr>\n";
          }
        ?>
      </tbody>
    </table>
     <?php mysql_close($connector); ?>
    </body>
    </html>

Print the stack trace of an exception

I have created a method that helps with getting the stackTrace:

private static String getStackTrace(Exception ex) {
    StringBuffer sb = new StringBuffer(500);
    StackTraceElement[] st = ex.getStackTrace();
    sb.append(ex.getClass().getName() + ": " + ex.getMessage() + "\n");
    for (int i = 0; i < st.length; i++) {
      sb.append("\t at " + st[i].toString() + "\n");
    }
    return sb.toString();
}

Android MediaPlayer Stop and Play

To stop the Media Player without the risk of an Illegal State Exception, you must do

  try {
        mp.reset();
        mp.prepare();
        mp.stop();
        mp.release();
        mp=null;
       }
  catch (Exception e)
         {
           e.printStackTrace();
         }

rather than just

try {
       mp.stop();
       mp.release();
       mp=null;
    } 
catch (Exception e) 
    {
      e.printStackTrace();
    }

Trigger standard HTML5 validation (form) without using submit button?

As stated in the other answers use event.preventDefault() to prevent form submitting.

To check the form before I wrote a little jQuery function you may use (note that the element needs an ID!)

(function( $ ){
    $.fn.isValid = function() {
        return document.getElementById(this[0].id).checkValidity();
    };
})( jQuery );

example usage

 $('#submitBtn').click( function(e){

        if ($('#registerForm').isValid()){
            // do the request
        } else {
            e.preventDefault();
        }
    });

What are valid values for the id attribute in HTML?

From the HTML 4 spec...

ID and NAME tokens must begin with a letter ([A-Za-z]) and may be followed by any number of letters, digits ([0-9]), hyphens ("-"), underscores ("_"), colons (":"), and periods (".").

EDIT: d'oh! Beaten to the button, again!

How to get row number in dataframe in Pandas?

 len(df[df["Lastname"]=="Smith"].values)

jQuery select element in parent window

why not both to be sure?

if(opener.document){
  $("#testdiv",opener.document).doStuff();
}else{
  $("#testdiv",window.opener).doStuff();
}

How to specify the actual x axis values to plot as x axis ticks in R

In case of plotting time series, the command ts.plot requires a different argument than xaxt="n"

require(graphics)
ts.plot(ldeaths, mdeaths, xlab="year", ylab="deaths", lty=c(1:2), gpars=list(xaxt="n"))
axis(1, at = seq(1974, 1980, by = 2))

What are carriage return, linefeed, and form feed?

On old paper-printer terminals, advancing to the next line involved two actions: moving the print head back to the beginning of the horizontal scan range (carriage return) and advancing the roll of paper being printed on (line feed).

Since we no longer use paper-printer terminals, those actions aren't really relevant anymore, but the characters used to signal them have stuck around in various incarnations.

Deadly CORS when http://localhost is the origin

I think my solution to this might be the simplest. On my development machine, I added a fake domain in my hosts file similar to http://myfakedomain.notarealtld and set it to 127.0.0.1. Then I changed my server's CORS configuration (in my case an S3 bucket) to allow that domain. That way I can use Chrome on localhost and it works great.

Make sure your CORS configuration takes into account the entire hostname with port, ie. http://myfakedomain.notarealtld:3000

You can modify your hosts file easily on Linux, Mac, and Windows.

ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/var/run/mysqld/mysqld.sock' (2)

Just copy your /opt/lampp/etc/my.cnf file to /etc/mysql/my.cnf.

And in the terminal type:

mysql -u root

You will be getting the mysql> prompt:

mysql> Update mysql.user set Password=PASSWORD('your_password') where user='root';

mysql> FLUSH PRIVILEGES;

How to reset or change the passphrase for a GitHub SSH key?

In short there's no way to recover the passphrase for a pair of SSH keys. Why? Because it was intended this way in the first place for security reasons. The answers the other people gave you are all correct ways to CHANGE the password of your keys, not to recover them. So if you've forgotten your passphrase, the best you can do is create a new pair of SSH keys. Here's how to generate SSH keys and add it to your GitHub account.

Trying to mock datetime.date.today(), but not working

Several solutions are discussed in http://blog.xelnor.net/python-mocking-datetime/. In summary:

Mock object - Simple and efficient but breaks isinstance() checks:

target = datetime.datetime(2009, 1, 1)
with mock.patch.object(datetime, 'datetime', mock.Mock(wraps=datetime.datetime)) as patched:
    patched.now.return_value = target
    print(datetime.datetime.now())

Mock class

import datetime
import mock

real_datetime_class = datetime.datetime

def mock_datetime_now(target, dt):
    class DatetimeSubclassMeta(type):
        @classmethod
        def __instancecheck__(mcs, obj):
            return isinstance(obj, real_datetime_class)

    class BaseMockedDatetime(real_datetime_class):
        @classmethod
        def now(cls, tz=None):
            return target.replace(tzinfo=tz)

        @classmethod
        def utcnow(cls):
            return target

    # Python2 & Python3 compatible metaclass
    MockedDatetime = DatetimeSubclassMeta('datetime', (BaseMockedDatetime,), {})

    return mock.patch.object(dt, 'datetime', MockedDatetime)

Use as:

with mock_datetime_now(target, datetime):
   ....

Remove all padding and margin table HTML and CSS

Try using tag body to remove all margin and padding like that you want.

<body style="margin: 0;padding: 0">
    <table border="1" width="100%" cellpadding="0" cellspacing="0" bgcolor=green>
        <tr>
            <td >&nbsp;</td>
            <td>&nbsp;</td>
        </tr>
        <tr>
            <td >&nbsp;</td>
            <td>&nbsp;</td>
        </tr>
        <tr>
            <td >&nbsp;</td>
            <td>&nbsp;</td>
        </tr>
    </table>
</body>

Select the values of one property on all objects of an array in PowerShell

To complement the preexisting, helpful answers with guidance of when to use which approach and a performance comparison.

  • Outside of a pipeline[1], use (PSv3+):

    $objects.Name
    as demonstrated in rageandqq's answer, which is both syntactically simpler and much faster.

    • Accessing a property at the collection level to get its members' values as an array is called member enumeration and is a PSv3+ feature.

    • Alternatively, in PSv2, use the foreach statement, whose output you can also assign directly to a variable:

      $results = foreach ($obj in $objects) { $obj.Name }

    • If collecting all output from a (pipeline) command in memory first is feasible, you can also combine pipelines with member enumeration; e.g.:

       (Get-ChildItem -File | Where-Object Length -lt 1gb).Name
      
    • Tradeoffs:

      • Both the input collection and output array must fit into memory as a whole.
      • If the input collection is itself the result of a command (pipeline) (e.g., (Get-ChildItem).Name), that command must first run to completion before the resulting array's elements can be accessed.
  • In a pipeline, in case you must pass the results to another command, notably if the original input doesn't fit into memory as a whole, use:

    $objects | Select-Object -ExpandProperty Name

    • The need for -ExpandProperty is explained in Scott Saad's answer (you need it to get only the property value).
    • You get the usual pipeline benefits of the pipeline's streaming behavior, i.e. one-by-one object processing, which typically produces output right away and keeps memory use constant (unless you ultimately collect the results in memory anyway).
    • Tradeoff:
      • Use of the pipeline is comparatively slow.

For small input collections (arrays), you probably won't notice the difference, and, especially on the command line, sometimes being able to type the command easily is more important.


Here is an easy-to-type alternative, which, however is the slowest approach; it uses simplified ForEach-Object syntax called an operation statement (again, PSv3+): ; e.g., the following PSv3+ solution is easy to append to an existing command:

$objects | % Name      # short for: $objects | ForEach-Object -Process { $_.Name }

The PSv4+ .ForEach() array method, more comprehensively discussed in this article, is yet another, well-performing alternative, but note that it requires collecting all input in memory first, just like member enumeration:

# By property name (string):
$objects.ForEach('Name')

# By script block (more flexibility; like ForEach-Object)
$objects.ForEach({ $_.Name })
  • This approach is similar to member enumeration, with the same tradeoffs, except that pipeline logic is not applied; it is marginally slower than member enumeration, though still noticeably faster than the pipeline.

  • For extracting a single property value by name (string argument), this solution is on par with member enumeration (though the latter is syntactically simpler).

  • The script-block variant ({ ... }) allows arbitrary transformations; it is a faster - all-in-memory-at-once - alternative to the pipeline-based ForEach-Object cmdlet (%).

Note: The .ForEach() array method, like its .Where() sibling (the in-memory equivalent of Where-Object), always returns a collection (an instance of [System.Collections.ObjectModel.Collection[psobject]]), even if only one output object is produced.
By contrast, member enumeration, Select-Object, ForEach-Object and Where-Object return a single output object as-is, without wrapping it in a collection (array).


Comparing the performance of the various approaches

Here are sample timings for the various approaches, based on an input collection of 10,000 objects, averaged across 10 runs; the absolute numbers aren't important and vary based on many factors, but it should give you a sense of relative performance (the timings come from a single-core Windows 10 VM:

Important

  • The relative performance varies based on whether the input objects are instances of regular .NET Types (e.g., as output by Get-ChildItem) or [pscustomobject] instances (e.g., as output by Convert-FromCsv).
    The reason is that [pscustomobject] properties are dynamically managed by PowerShell, and it can access them more quickly than the regular properties of a (statically defined) regular .NET type. Both scenarios are covered below.

  • The tests use already-in-memory-in-full collections as input, so as to focus on the pure property extraction performance. With a streaming cmdlet / function call as the input, performance differences will generally be much less pronounced, as the time spent inside that call may account for the majority of the time spent.

  • For brevity, alias % is used for the ForEach-Object cmdlet.

General conclusions, applicable to both regular .NET type and [pscustomobject] input:

  • The member-enumeration ($collection.Name) and foreach ($obj in $collection) solutions are by far the fastest, by a factor of 10 or more faster than the fastest pipeline-based solution.

  • Surprisingly, % Name performs much worse than % { $_.Name } - see this GitHub issue.

  • PowerShell Core consistently outperforms Windows Powershell here.

Timings with regular .NET types:

  • PowerShell Core v7.0.0-preview.3
Factor Command                                       Secs (10-run avg.)
------ -------                                       ------------------
1.00   $objects.Name                                 0.005
1.06   foreach($o in $objects) { $o.Name }           0.005
6.25   $objects.ForEach('Name')                      0.028
10.22  $objects.ForEach({ $_.Name })                 0.046
17.52  $objects | % { $_.Name }                      0.079
30.97  $objects | Select-Object -ExpandProperty Name 0.140
32.76  $objects | % Name                             0.148
  • Windows PowerShell v5.1.18362.145
Factor Command                                       Secs (10-run avg.)
------ -------                                       ------------------
1.00   $objects.Name                                 0.012
1.32   foreach($o in $objects) { $o.Name }           0.015
9.07   $objects.ForEach({ $_.Name })                 0.105
10.30  $objects.ForEach('Name')                      0.119
12.70  $objects | % { $_.Name }                      0.147
27.04  $objects | % Name                             0.312
29.70  $objects | Select-Object -ExpandProperty Name 0.343

Conclusions:

  • In PowerShell Core, .ForEach('Name') clearly outperforms .ForEach({ $_.Name }). In Windows PowerShell, curiously, the latter is faster, albeit only marginally so.

Timings with [pscustomobject] instances:

  • PowerShell Core v7.0.0-preview.3
Factor Command                                       Secs (10-run avg.)
------ -------                                       ------------------
1.00   $objects.Name                                 0.006
1.11   foreach($o in $objects) { $o.Name }           0.007
1.52   $objects.ForEach('Name')                      0.009
6.11   $objects.ForEach({ $_.Name })                 0.038
9.47   $objects | Select-Object -ExpandProperty Name 0.058
10.29  $objects | % { $_.Name }                      0.063
29.77  $objects | % Name                             0.184
  • Windows PowerShell v5.1.18362.145
Factor Command                                       Secs (10-run avg.)
------ -------                                       ------------------
1.00   $objects.Name                                 0.008
1.14   foreach($o in $objects) { $o.Name }           0.009
1.76   $objects.ForEach('Name')                      0.015
10.36  $objects | Select-Object -ExpandProperty Name 0.085
11.18  $objects.ForEach({ $_.Name })                 0.092
16.79  $objects | % { $_.Name }                      0.138
61.14  $objects | % Name                             0.503

Conclusions:

  • Note how with [pscustomobject] input .ForEach('Name') by far outperforms the script-block based variant, .ForEach({ $_.Name }).

  • Similarly, [pscustomobject] input makes the pipeline-based Select-Object -ExpandProperty Name faster, in Windows PowerShell virtually on par with .ForEach({ $_.Name }), but in PowerShell Core still about 50% slower.

  • In short: With the odd exception of % Name, with [pscustomobject] the string-based methods of referencing the properties outperform the scriptblock-based ones.


Source code for the tests:

Note:

  • Download function Time-Command from this Gist to run these tests.

    • Assuming you have looked at the linked code to ensure that it is safe (which I can personally assure you of, but you should always check), you can install it directly as follows:

      irm https://gist.github.com/mklement0/9e1f13978620b09ab2d15da5535d1b27/raw/Time-Command.ps1 | iex
      
  • Set $useCustomObjectInput to $true to measure with [pscustomobject] instances instead.

$count = 1e4 # max. input object count == 10,000
$runs  = 10  # number of runs to average 

# Note: Using [pscustomobject] instances rather than instances of 
#       regular .NET types changes the performance characteristics.
# Set this to $true to test with [pscustomobject] instances below.
$useCustomObjectInput = $false

# Create sample input objects.
if ($useCustomObjectInput) {
  # Use [pscustomobject] instances.
  $objects = 1..$count | % { [pscustomobject] @{ Name = "$foobar_$_"; Other1 = 1; Other2 = 2; Other3 = 3; Other4 = 4 } }
} else {
  # Use instances of a regular .NET type.
  # Note: The actual count of files and folders in your file-system
  #       may be less than $count
  $objects = Get-ChildItem / -Recurse -ErrorAction Ignore | Select-Object -First $count
}

Write-Host "Comparing property-value extraction methods with $($objects.Count) input objects, averaged over $runs runs..."

# An array of script blocks with the various approaches.
$approaches = { $objects | Select-Object -ExpandProperty Name },
              { $objects | % Name },
              { $objects | % { $_.Name } },
              { $objects.ForEach('Name') },
              { $objects.ForEach({ $_.Name }) },
              { $objects.Name },
              { foreach($o in $objects) { $o.Name } }

# Time the approaches and sort them by execution time (fastest first):
Time-Command $approaches -Count $runs | Select Factor, Command, Secs*

[1] Technically, even a command without |, the pipeline operator, uses a pipeline behind the scenes, but for the purpose of this discussion using the pipeline refers only to commands that do use | and therefore involve multiple commands connected by a pipeline.

How to equalize the scales of x-axis and y-axis in Python matplotlib?

Try something like:

import pylab as p
p.plot(x,y)
p.axis('equal')
p.show()

endsWith in JavaScript

Just another quick alternative that worked like a charm for me, using regex:

// Would be equivalent to:
// "Hello World!".endsWith("World!")
"Hello World!".match("World!$") != null

"com.jcraft.jsch.JSchException: Auth fail" with working passwords

If username/password contains any special characters then inside the camel configuration use RAW for Configuring the values like

  • RAW(se+re?t&23) where se+re?t&23 is actual password

  • RAW({abc.ftp.password}) where {abc.ftp.password} values comes from a spring property file.

By using RAW, solved my issue.

http://camel.apache.org/how-do-i-configure-endpoints.html

Send data from activity to fragment in Android

You can make a setter method in the fragment. Then in the Activity, when you reference to the fragment, you call the setter method and pass it the data from you Activity

SQL how to check that two tables has exactly the same data?

We can compare data from two tables of DB2 tables using the below simple query,

Step 1:- Select which all columns we need to compare from table (T1) of schema(S)

     SELECT T1.col1,T1.col3,T1.col5 from S.T1

Step 2:- Use 'Minus' keyword for comparing 2 tables.

Step 3:- Select which all columns we need to compare from table (T2) of schema(S)

     SELECT T2.col1,T2.col3,T2.col5 from S.T1

END result:

     SELECT T1.col1,T1.col3,T1.col5 from S.T1
     MINUS 
     SELECT T2.col1,T2.col3,T2.col5 from S.T1;

If the query returns no rows then the data is exactly the same.

How to set border's thickness in percentages?

Box Sizing
set the box sizing to border box box-sizing: border-box; and set the width to 100% and a fixed width for the border then add a min-width so for a small screen the border won't overtake the whole screen

Facebook api: (#4) Application request limit reached

now Application-Level Rate Limiting 200 calls per hour !

you can look this image.enter image description here

Converting between strings and ArrayBuffers

Recently I also need to do this for one of my project so did a well research and got a result from Google's Developer community which states this in a simple manner:

For ArrayBuffer to String

function ab2str(buf) {
  return String.fromCharCode.apply(null, new Uint16Array(buf));
}
// Here Uint16 can be different like Uinit8/Uint32 depending upon your buffer value type.

For String to ArrayBuffer

function str2ab(str) {
  var buf = new ArrayBuffer(str.length*2); // 2 bytes for each char
  var bufView = new Uint16Array(buf);
  for (var i=0, strLen=str.length; i < strLen; i++) {
    bufView[i] = str.charCodeAt(i);
  }
  return buf;
}
//Same here also for the Uint16Array.

For more in detail reference you can refer this blog by Google.

Increment counter with loop

Try the following:

<c:set var="count" value="0" scope="page" />

//in your loops
<c:set var="count" value="${count + 1}" scope="page"/>

Why Does OAuth v2 Have Both Access and Refresh Tokens?

Let's consider a system where each user is linked to one or more roles and each role is linked to one or more access privileges. This information can be cached for better API performance. But then, there may be changes in the user and role configurations (for e.g. new access may be granted or current access may be revoked) and these should be reflected in the cache.

We can use access and refresh tokens for such purpose. When an API is invoked with access token, the resource server checks the cache for access rights. IF there is any new access grants, it is not reflected immediately. Once the access token expires (say in 30 minutes) and the client uses the refresh token to generate a new access token, the cache can be updated with the updated user access right information from the DB.

In other words, we can move the expensive operations from every API call using access tokens to the event of access token generation using refresh token.

docker: Error response from daemon: Get https://registry-1.docker.io/v2/: Service Unavailable. IN DOCKER , MAC

Just to add, in case anyone else comes across this issue.

On a Mac I had to logout and log back in.

docker logout

docker login 

Then it prompts for username (NOTE: Not email) and password. (Need an account on https://hub.docker.com to pull images down)

Then it worked for me.

Why am I getting "Unable to find manifest signing certificate in the certificate store" in my Excel Addin?

Make sure you commit .pfx files to repository.

I just found *.pfx in my default .gitignore. Comment it (by #) and commit changes. Then pull repository and rebuild.

Docker: How to delete all local Docker images

Here is the command I used and put it in a batch file to remove everything:

echo "Removing containers :" && if [ -n "$(docker container ls -aq)" ]; then docker container stop $(docker container ls -aq); docker container rm $(docker container ls -aq); fi; echo "Removing images :" && if [ -n "$(docker images -aq)" ]; then docker rmi -f $(docker images -aq); fi; echo "Removing volumes :" && if [ -n "$(docker volume ls -q)" ]; then docker volume rm $(docker volume ls -q); fi; echo "Removing networks :" && if [ -n "$(docker network ls | awk '{print $1" "$2}' | grep -v 'ID|bridge|host|none' | awk '{print $1}')" ]; then docker network rm $(docker network ls | awk '{print $1" "$2}' | grep -v 'ID|bridge|host|none' | awk '{print $1}'); fi;

push_back vs emplace_back

A nice code for the push_back and emplace_back is shown here.

http://en.cppreference.com/w/cpp/container/vector/emplace_back

You can see the move operation on push_back and not on emplace_back.

Hibernate JPA Sequence (non-Id)

Although this is an old thread I want to share my solution and hopefully get some feedback on this. Be warned that I only tested this solution with my local database in some JUnit testcase. So this is not a productive feature so far.

I solved that issue for my by introducing a custom annotation called Sequence with no property. It's just a marker for fields that should be assigned a value from an incremented sequence.

@Retention(RetentionPolicy.RUNTIME)
@Target(ElementType.FIELD)
public @interface Sequence
{
}

Using this annotation i marked my entities.

public class Area extends BaseEntity implements ClientAware, IssuerAware
{
    @Column(name = "areaNumber", updatable = false)
    @Sequence
    private Integer areaNumber;
....
}

To keep things database independent I introduced an entity called SequenceNumber which holds the sequence current value and the increment size. I chose the className as unique key so each entity class wil get its own sequence.

@Entity
@Table(name = "SequenceNumber", uniqueConstraints = { @UniqueConstraint(columnNames = { "className" }) })
public class SequenceNumber
{
    @Id
    @Column(name = "className", updatable = false)
    private String className;

    @Column(name = "nextValue")
    private Integer nextValue = 1;

    @Column(name = "incrementValue")
    private Integer incrementValue = 10;

    ... some getters and setters ....
}

The last step and the most difficult is a PreInsertListener that handles the sequence number assignment. Note that I used spring as bean container.

@Component
public class SequenceListener implements PreInsertEventListener
{
    private static final long serialVersionUID = 7946581162328559098L;
    private final static Logger log = Logger.getLogger(SequenceListener.class);

    @Autowired
    private SessionFactoryImplementor sessionFactoryImpl;

    private final Map<String, CacheEntry> cache = new HashMap<>();

    @PostConstruct
    public void selfRegister()
    {
        // As you might expect, an EventListenerRegistry is the place with which event listeners are registered
        // It is a service so we look it up using the service registry
        final EventListenerRegistry eventListenerRegistry = sessionFactoryImpl.getServiceRegistry().getService(EventListenerRegistry.class);

        // add the listener to the end of the listener chain
        eventListenerRegistry.appendListeners(EventType.PRE_INSERT, this);
    }

    @Override
    public boolean onPreInsert(PreInsertEvent p_event)
    {
        updateSequenceValue(p_event.getEntity(), p_event.getState(), p_event.getPersister().getPropertyNames());

        return false;
    }

    private void updateSequenceValue(Object p_entity, Object[] p_state, String[] p_propertyNames)
    {
        try
        {
            List<Field> fields = ReflectUtil.getFields(p_entity.getClass(), null, Sequence.class);

            if (!fields.isEmpty())
            {
                if (log.isDebugEnabled())
                {
                    log.debug("Intercepted custom sequence entity.");
                }

                for (Field field : fields)
                {
                    Integer value = getSequenceNumber(p_entity.getClass().getName());

                    field.setAccessible(true);
                    field.set(p_entity, value);
                    setPropertyState(p_state, p_propertyNames, field.getName(), value);

                    if (log.isDebugEnabled())
                    {
                        LogMF.debug(log, "Set {0} property to {1}.", new Object[] { field, value });
                    }
                }
            }
        }
        catch (Exception e)
        {
            log.error("Failed to set sequence property.", e);
        }
    }

    private Integer getSequenceNumber(String p_className)
    {
        synchronized (cache)
        {
            CacheEntry current = cache.get(p_className);

            // not in cache yet => load from database
            if ((current == null) || current.isEmpty())
            {
                boolean insert = false;
                StatelessSession session = sessionFactoryImpl.openStatelessSession();
                session.beginTransaction();

                SequenceNumber sequenceNumber = (SequenceNumber) session.get(SequenceNumber.class, p_className);

                // not in database yet => create new sequence
                if (sequenceNumber == null)
                {
                    sequenceNumber = new SequenceNumber();
                    sequenceNumber.setClassName(p_className);
                    insert = true;
                }

                current = new CacheEntry(sequenceNumber.getNextValue() + sequenceNumber.getIncrementValue(), sequenceNumber.getNextValue());
                cache.put(p_className, current);
                sequenceNumber.setNextValue(sequenceNumber.getNextValue() + sequenceNumber.getIncrementValue());

                if (insert)
                {
                    session.insert(sequenceNumber);
                }
                else
                {
                    session.update(sequenceNumber);
                }
                session.getTransaction().commit();
                session.close();
            }

            return current.next();
        }
    }

    private void setPropertyState(Object[] propertyStates, String[] propertyNames, String propertyName, Object propertyState)
    {
        for (int i = 0; i < propertyNames.length; i++)
        {
            if (propertyName.equals(propertyNames[i]))
            {
                propertyStates[i] = propertyState;
                return;
            }
        }
    }

    private static class CacheEntry
    {
        private int current;
        private final int limit;

        public CacheEntry(final int p_limit, final int p_current)
        {
            current = p_current;
            limit = p_limit;
        }

        public Integer next()
        {
            return current++;
        }

        public boolean isEmpty()
        {
            return current >= limit;
        }
    }
}

As you can see from the above code the listener used one SequenceNumber instance per entity class and reserves a couple of sequence numbers defined by the incrementValue of the SequenceNumber entity. If it runs out of sequence numbers it loads the SequenceNumber entity for the target class and reserves incrementValue values for the next calls. This way I do not need to query the database each time a sequence value is needed. Note the StatelessSession that is being opened for reserving the next set of sequence numbers. You cannot use the same session the target entity is currently persisted since this would lead to a ConcurrentModificationException in the EntityPersister.

Hope this helps someone.

Submit form using <a> tag

Here is how I would do it using vanilla JS

<form id="myform" method="POST" action="xxx">
    <!-- your stuff here -->
    <a href="javascript:void()" onclick="document.getElementById('myform').submit();>Ponies await!</a>
</form>

You can play with the return falses and href="#" vs void and whatever you need to but this method worked for me in Chrome 18, IE 9 and Firefox 14 and the rest depends on your javascript mostly.

css display table cell requires percentage width

Note also that vertical-align:top; is often necessary for correct table cell appearance.

css table-cell, contents have unnecessary top margin

What is Options +FollowSymLinks?

You might try searching the internet for ".htaccess Options not allowed here".

A suggestion I found (using google) is:

Check to make sure that your httpd.conf file has AllowOverride All.

A .htaccess file that works for me on Mint Linux (placed in the Laravel /public folder):

# Apache configuration file
# http://httpd.apache.org/docs/2.2/mod/quickreference.html

# Turning on the rewrite engine is necessary for the following rules and
# features. "+FollowSymLinks" must be enabled for this to work symbolically.

<IfModule mod_rewrite.c>
    Options +FollowSymLinks
    RewriteEngine On
</IfModule>

# For all files not found in the file system, reroute the request to the
# "index.php" front controller, keeping the query string intact

<IfModule mod_rewrite.c>
    RewriteCond %{REQUEST_FILENAME} !-f
    RewriteCond %{REQUEST_FILENAME} !-d
    RewriteRule ^(.*)$ index.php/$1 [L]
</IfModule>

Hope this helps you. Otherwise you could ask a question on the Laravel forum (http://forums.laravel.com/), there are some really helpful people hanging around there.

Convert date to YYYYMM format

I know it is an old topic, but If your SQL server version is higher than 2012.

There is another simple option can choose, FORMAT function.

SELECT FORMAT(GetDate(),'yyyyMM')

sqlfiddle

Convert Pandas column containing NaNs to dtype `int`

If you want to use it when you chain methods, you can use assign:

df = (
     df.assign(col = lambda x: x['col'].astype('Int64'))
)

Oracle: what is the situation to use RAISE_APPLICATION_ERROR?

There are two uses for RAISE_APPLICATION_ERROR. The first is to replace generic Oracle exception messages with our own, more meaningful messages. The second is to create exception conditions of our own, when Oracle would not throw them.

The following procedure illustrates both usages. It enforces a business rule that new employees cannot be hired in the future. It also overrides two Oracle exceptions. One is DUP_VAL_ON_INDEX, which is thrown by a unique key on EMP(ENAME). The other is a a user-defined exception thrown when the foreign key between EMP(MGR) and EMP(EMPNO) is violated (because a manager must be an existing employee).

create or replace procedure new_emp
    ( p_name in emp.ename%type
      , p_sal in emp.sal%type
      , p_job in emp.job%type
      , p_dept in emp.deptno%type
      , p_mgr in emp.mgr%type 
      , p_hired in emp.hiredate%type := sysdate )
is
    invalid_manager exception;
    PRAGMA EXCEPTION_INIT(invalid_manager, -2291);
    dummy varchar2(1);
begin
    -- check hiredate is valid
    if trunc(p_hired) > trunc(sysdate) 
    then
        raise_application_error
            (-20000
             , 'NEW_EMP::hiredate cannot be in the future'); 
    end if;

    insert into emp
        ( ename
          , sal
          , job
          , deptno
          , mgr 
          , hiredate )
    values      
        ( p_name
          , p_sal
          , p_job
          , p_dept
          , p_mgr 
          , trunc(p_hired) );
exception
    when dup_val_on_index then
        raise_application_error
            (-20001
             , 'NEW_EMP::employee called '||p_name||' already exists'
             , true); 
    when invalid_manager then
        raise_application_error
            (-20002
             , 'NEW_EMP::'||p_mgr ||' is not a valid manager'); 

end;
/

How it looks:

SQL> exec new_emp ('DUGGAN', 2500, 'SALES', 10, 7782, sysdate+1)
BEGIN new_emp ('DUGGAN', 2500, 'SALES', 10, 7782, sysdate+1); END;

*
ERROR at line 1:
ORA-20000: NEW_EMP::hiredate cannot be in the future
ORA-06512: at "APC.NEW_EMP", line 16
ORA-06512: at line 1

SQL>
SQL> exec new_emp ('DUGGAN', 2500, 'SALES', 10, 8888, sysdate)
BEGIN new_emp ('DUGGAN', 2500, 'SALES', 10, 8888, sysdate); END;

*
ERROR at line 1:
ORA-20002: NEW_EMP::8888 is not a valid manager
ORA-06512: at "APC.NEW_EMP", line 42
ORA-06512: at line 1


SQL>
SQL> exec new_emp ('DUGGAN', 2500, 'SALES', 10, 7782, sysdate)

PL/SQL procedure successfully completed.

SQL>
SQL> exec new_emp ('DUGGAN', 2500, 'SALES', 10, 7782, sysdate)
BEGIN new_emp ('DUGGAN', 2500, 'SALES', 10, 7782, sysdate); END;

*
ERROR at line 1:
ORA-20001: NEW_EMP::employee called DUGGAN already exists
ORA-06512: at "APC.NEW_EMP", line 37
ORA-00001: unique constraint (APC.EMP_UK) violated
ORA-06512: at line 1

Note the different output from the two calls to RAISE_APPLICATION_ERROR in the EXCEPTIONS block. Setting the optional third argument to TRUE means RAISE_APPLICATION_ERROR includes the triggering exception in the stack, which can be useful for diagnosis.

There is more useful information in the PL/SQL User's Guide.

AVD Manager - No system image installed for this target

you should android sdk manager install 4.2 api 17 -> ARM EABI v7a System Image

if not installed ARM EABI v7a System Image, you should install all.

C++ preprocessor __VA_ARGS__ number of arguments

Boost Preprocessor actually has this as of Boost 1.49, as BOOST_PP_VARIADIC_SIZE(...). It works up to size 64.

Under the hood, it's basically the same as Kornel Kisielewicz's answer.

Converting NSString to NSDate (and back again)

The above examples aren't simply written for Swift 3.0+

Update - Swift 3.0+ - Convert Date To String

let date = Date() // insert your date data here
var dateFormatter = DateFormatter()
dateFormatter.dateFormat = "yyyy-MM-dd" // add custom format if you'd like 
var dateString = dateFormatter.string(from: date)

Adding click event for a button created dynamically using jQuery

Use

$(document).on("click", "#btn_a", function(){
  alert ('button clicked');
});

to add the listener for the dynamically created button.

alert($("#btn_a").val());

will give you the value of the button

Detecting touch screen devices with Javascript

For my first post/comment: We all know that 'touchstart' is triggered before click. We also know that when user open your page he or she will: 1) move the mouse 2) click 3) touch the screen (for scrolling, or ... :) )

Let's try something :

//--> Start: jQuery

var hasTouchCapabilities = 'ontouchstart' in window && (navigator.maxTouchPoints || navigator.msMaxTouchPoints);
var isTouchDevice = hasTouchCapabilities ? 'maybe':'nope';

//attach a once called event handler to window

$(window).one('touchstart mousemove click',function(e){

    if ( isTouchDevice === 'maybe' && e.type === 'touchstart' )
        isTouchDevice = 'yes';
});

//<-- End: jQuery

Have a nice day!

How to send objects through bundle

another simple way to pass object using a bundle:

  • in the class object, create a static list or another data structure with a key
  • when you create the object, put it in the list/data structure with the key (es. the long timestamp when the object is created)
  • create the method static getObject(long key) to get the object from the list
  • in the bundle pass the key, so you can get the object later from another point in the code

Manually type in a value in a "Select" / Drop-down HTML list?

ExtJS has a ComboBox control that can do this (and a whole host of other cool stuff!!)

EDIT: Browse all controls etc, here: http://www.sencha.com/products/js/

Android: how to create Switch case from this?

You can do this:

@Override
protected Dialog onCreateDialog(int id) {
    String messageDialog;
    String valueOK;
    String valueCancel;
    String titleDialog;
    switch (id) {

    case id:
        titleDialog = itemTitle;
        messageDialog = itemDescription
        valueOK = "OK";            
        return new AlertDialog.Builder(HomeView.this).setTitle(titleDialog).setPositiveButton(valueOK, new DialogInterface.OnClickListener() {
            public void onClick(DialogInterface dialog, int whichButton) {
                Log.d(this.getClass().getName(), "AlertItem");
            }
        }).setMessage(messageDialog).create(); 

and then call to

showDialog(numbreOfItem);

How to set Grid row and column positions programmatically

Try this:

                Grid grid = new Grid(); //Define the grid
                for (int i = 0; i < 36; i++) //Add 36 rows
                {
                    ColumnDefinition columna = new ColumnDefinition()
                    {
                        Name = "Col_" + i,
                        Width = new GridLength(32.5),
                    };
                    grid.ColumnDefinitions.Add(columna);
                }

                for (int i = 0; i < 36; i++) //Add 36 columns
                {
                    RowDefinition row = new RowDefinition();
                    row.Height = new GridLength(40, GridUnitType.Pixel);
                    grid.RowDefinitions.Add(row);
                }

                for (int i = 0; i < 36; i++)
                {
                    for (int j = 0; j < 36; j++)
                    {
                        Label t1 = new Label()
                        {
                            FontSize = 10,
                            FontFamily = new FontFamily("consolas"),
                            FontWeight = FontWeights.SemiBold,
                            BorderBrush = Brushes.LightGray,
                            BorderThickness = new Thickness(2),
                            HorizontalContentAlignment = HorizontalAlignment.Center,
                            VerticalContentAlignment = VerticalAlignment.Center,
                        };
                        Grid.SetRow(t1, i);
                        Grid.SetColumn(t1, j);
                        grid.Children.Add(t1); //Add the Label Control to the Grid created
                    }
                }

How to search for occurrences of more than one space between words in a line

Simple solution:

/\s{2,}/

This matches all occurrences of one or more whitespace characters. If you need to match the entire line, but only if it contains two or more consecutive whitespace characters:

/^.*\s{2,}.*$/

If the whitespaces don't need to be consecutive:

/^(.*\s.*){2,}$/

View's getWidth() and getHeight() returns 0

A Kotlin Extension to observe on the global layout and perform a given task when height is ready dynamically.

Usage:

view.height { Log.i("Info", "Here is your height:" + it) }

Implementation:

fun <T : View> T.height(function: (Int) -> Unit) {
    if (height == 0)
        viewTreeObserver.addOnGlobalLayoutListener(object : ViewTreeObserver.OnGlobalLayoutListener {
            override fun onGlobalLayout() {
                viewTreeObserver.removeOnGlobalLayoutListener(this)
                function(height)
            }
        })
    else function(height)
}

Powershell command to hide user from exchange address lists

I use this as a daily scheduled task to hide users disabled in AD from the Global Address List

$mailboxes = get-user | where {$_.UserAccountControl -like '*AccountDisabled*' -and $_.RecipientType -eq 'UserMailbox' } | get-mailbox  | where {$_.HiddenFromAddressListsEnabled -eq $false}

foreach ($mailbox in $mailboxes) { Set-Mailbox -HiddenFromAddressListsEnabled $true -Identity $mailbox }

String.Format like functionality in T-SQL?

One more idea.

Although this is not a universal solution - it is simple and works, at least for me :)

For one placeholder {0}:

create function dbo.Format1
(
    @String  nvarchar(4000),
    @Param0  sql_variant
)
returns nvarchar(4000)
as
begin
    declare @Null nvarchar(4) = N'NULL';

    return replace(@String, N'{0}', cast(isnull(@Param0, @Null) as nvarchar(4000)));    
end

For two placeholders {0} and {1}:

create function dbo.Format2
(
    @String  nvarchar(4000),
    @Param0  sql_variant,
    @Param1  sql_variant
)
returns nvarchar(4000)
as
begin
    declare @Null nvarchar(4) = N'NULL';

    set @String = replace(@String, N'{0}', cast(isnull(@Param0, @Null) as nvarchar(4000)));
       return     replace(@String, N'{1}', cast(isnull(@Param1, @Null) as nvarchar(4000))); 
end

For three placeholders {0}, {1} and {2}:

create function dbo.Format3
(
    @String  nvarchar(4000),
    @Param0  sql_variant,
    @Param1  sql_variant,
    @Param2  sql_variant
)
returns nvarchar(4000)
as
begin
    declare @Null nvarchar(4) = N'NULL';

    set @String = replace(@String, N'{0}', cast(isnull(@Param0, @Null) as nvarchar(4000)));
    set @String = replace(@String, N'{1}', cast(isnull(@Param1, @Null) as nvarchar(4000))); 
       return     replace(@String, N'{2}', cast(isnull(@Param2, @Null) as nvarchar(4000)));
end

and so on...

Such an approach allows us to use these functions in SELECT statement and with parameters of nvarchar, number, bit and datetime datatypes.

For example:

declare @Param0 nvarchar(10) = N'IPSUM' ,
        @Param1 int          = 1234567  ,
        @Param2 datetime2(0) = getdate();

select dbo.Format3(N'Lorem {0} dolor, {1} elit at {2}', @Param0, @Param1, @Param2);  

How to convert a DataFrame back to normal RDD in pyspark?

@dapangmao's answer works, but it doesn't give the regular spark RDD, it returns a Row object. If you want to have the regular RDD format.

Try this:

rdd = df.rdd.map(tuple)

or

rdd = df.rdd.map(list)

The imported project "C:\Microsoft.CSharp.targets" was not found

I used to have this following line in the csproj file:

<Import Project="$(MSBuildExtensionsPath32)\Microsoft\VisualStudio\v10.0\WebApplications\Microsoft.WebApplication.targets" />

After deleting this file, it works fine.

Removing object properties with Lodash

You can easily do this using _.pick:

_x000D_
_x000D_
var model = {
  fname: null,
  lname: null
};

var credentials = {
  fname: 'abc',
  lname: 'xyz',
  age: 2
};

var result = _.pick(credentials, _.keys(model));


console.log('result =', result);
_x000D_
<script src="https://cdn.jsdelivr.net/lodash/4.16.4/lodash.min.js"></script>
_x000D_
_x000D_
_x000D_

But you can simply use pure JavaScript (specially if you use ECMAScript 6), like this:

_x000D_
_x000D_
const model = {
  fname: null,
  lname: null
};

const credentials = {
  fname: 'abc',
  lname: 'xyz',
  age: 2
};

const newModel = {};

Object.keys(model).forEach(key => newModel[key] = credentials[key]);

console.log('newModel =', newModel);
_x000D_
_x000D_
_x000D_

How to create a unique index on a NULL column?

Pretty sure you can't do that, as it violates the purpose of uniques.

However, this person seems to have a decent work around: http://sqlservercodebook.blogspot.com/2008/04/multiple-null-values-in-unique-index-in.html

Form Submit Execute JavaScript Best Practice?

Attach an event handler to the submit event of the form. Make sure it cancels the default action.

Quirks Mode has a guide to event handlers, but you would probably be better off using a library to simplify the code and iron out the differences between browsers. All the major ones (such as YUI and jQuery) include event handling features, and there is a large collection of tiny event libraries.

Here is how you would do it in YUI 3:

<script src="http://yui.yahooapis.com/3.4.1/build/yui/yui-min.js"></script>
<script>
    YUI().use('event', function (Y) {
        Y.one('form').on('submit', function (e) {
            // Whatever else you want to do goes here
            e.preventDefault();
        });
    });
</script>

Make sure that the server will pick up the slack if the JavaScript fails for any reason.

How to draw border on just one side of a linear layout?

An other great example example

<?xml version="1.0" encoding="UTF-8" standalone="no"?> 
<inset xmlns:android="http://schemas.android.com/apk/res/android"
     android:insetRight="-2dp">

     <shape android:shape="rectangle">
         <corners
             android:bottomLeftRadius="4dp"
             android:bottomRightRadius="0dp"
             android:topLeftRadius="4dp"
             android:topRightRadius="0dp" />
         <stroke
             android:width="1dp"
             android:color="@color/nasty_green" />
         <solid android:color="@android:color/transparent" />
     </shape>

</inset>

Center Div inside another (100% width) div

.parent { text-align: center; }
.parent > .child { margin: 0 auto; width: 900px; }

Entry point for Java applications: main(), init(), or run()?

The main() method is the entry point for a Java application. run() is typically used for new threads or tasks.

Where have you been writing a run() method, what kind of application are you writing (e.g. Swing, AWT, console etc) and what's your development environment?

Return HTTP status code 201 in flask

you can also use flask_api for sending response

from flask_api import status

@app.route('/your-api/')
def empty_view(self):
    content = {'your content here'}
    return content, status.HTTP_201_CREATED

you can find reference here http://www.flaskapi.org/api-guide/status-codes/

How do I ignore files in Subversion?

When using propedit make sure not have any trailing spaces as that will cause the file to be excluded from the ignore list.

These are inserted automatically if you've use tab-autocomplete on linux to create the file to begin with:

svn propset svn:ignore 'file1
file2' .

How to install a package inside virtualenv?

To use the environment virtualenv has created, you first need to source env/bin/activate. After that, just install packages using pip install package-name.

LINQ Group By and select collection

you can achive it with group join

var result = (from c in Customers
          join oi in OrderItems on c.Id equals oi.Order.Customer.Id into g
          Select new { customer = c, orderItems = g});

c is Customer and g is the customers order items.

How to view DLL functions?

For .NET DLLs you can use ildasm

Submit form using a button outside the <form> tag

You can tell a form that an external component from outside the <form> tag belongs to it by adding the form="yourFormName" to the definition of the component.

In this case,

<form id="login-form">
... blah...
</form>

<button type="submit" form="login-form" name="login_user" class="login-form-btn">
        <B>Autentificate</B>
</button>

... would still submit the form happily because you assigned the form name to it. The form thinks the button is part of it, even if the button is outside the tag, and this requires NO javascript to submit the form (which can be buggy i.e. form may submit but bootstrap errors / validations my fail to show, I tested).

Find unique rows in numpy.array

Yet another possible solution

np.vstack({tuple(row) for row in a})

How can I change the remote/target repository URL on Windows?

Take a look in .git/config and make the changes you need.

Alternatively you could use

git remote rm [name of the url you sets on adding]

and

git remote add [name] [URL]

Or just

git remote set-url [URL]

Before you do anything wrong, double check with

git help remote

How to add Python to Windows registry

When installing Python 3.4 the "Add python.exe to Path" came up unselected. Re-installed with this selected and problem resolved.

Where do I put my php files to have Xampp parse them?

When in a window, go to GO ---> ENTER LOCATION... And then copy paste this: /opt/lampp/htdocs

Now you are at the htdocs folder. Then you can add your files there, or in a new folder inside this one (for example "myproyects" folder and inside it your files... and then from a navigator you access it by writting: localhost/myproyects/nameofthefile.php

What I did to find it easily everytime, was right click on "myproyects" folder and "Make link..."... then I moved this link I created to the Desktop and then I didn't have to go anymore to the htdocs, but just enter the folder I created in my Desktop.

Hope it helps!!

inline conditionals in angular.js

Angular 1.1.5 added support for ternary operators:

{{myVar === "two" ? "it's true" : "it's false"}}

How to delete a line from a text file in C#?

To remove an item from a text file, first move all the text to a list and remove whichever item you want. Then write the text stored in the list into a text file:

List<string> quotelist=File.ReadAllLines(filename).ToList();
string firstItem= quotelist[0];
quotelist.RemoveAt(0);
File.WriteAllLines(filename, quotelist.ToArray());
return firstItem;

What is a semaphore?

Semaphore can also be used as a ... semaphore. For example if you have multiple process enqueuing data to a queue, and only one task consuming data from the queue. If you don't want your consuming task to constantly poll the queue for available data, you can use semaphore.

Here the semaphore is not used as an exclusion mechanism, but as a signaling mechanism. The consuming task is waiting on the semaphore The producing task are posting on the semaphore.

This way the consuming task is running when and only when there is data to be dequeued

Groovy Shell warning "Could not open/create prefs root node ..."

I was able to resolve the problem by manually creating the following registry key:

HKEY_LOCAL_MACHINE\Software\JavaSoft\Prefs

C#: Converting byte array to string and printing out to console

 byte[] bytes = { 1,2,3,4 };

 string stringByte= BitConverter.ToString(bytes);

 Console.WriteLine(stringByte);

How to get distinct values for non-key column fields in Laravel?

// Get unique value for table 'add_new_videos' column name 'project_id'
$project_id = DB::table('add_new_videos')->distinct()->get(['project_id']);

how to fetch data from database in Hibernate

I know that it is very late to answer the question, but it may help someone like me who spent lots off time to fetch data using hql

So the thing is you just have to write a query

Query query = session.createQuery("from Employee");

it will give you all the data list but to fetch data from this you have to write this line.

List<Employee> fetchedData = query.list();

As simple as it looks.

forEach loop Java 8 for Map entry set

String ss = "Pawan kavita kiyansh Patidar Patidar";
    StringBuilder ress = new StringBuilder();
    
    Map<Character, Integer> fre = ss.chars().boxed()
            .collect(Collectors.toMap(k->Character.valueOf((char) k.intValue()),k->1,Integer::sum));
    
      //fre.forEach((k, v) -> System.out.println((k + ":" + v)));
    
    fre.entrySet().forEach(e ->{
            //System.out.println(e.getKey() + ":" + e.getValue());
            //ress.append(String.valueOf(e.getKey())+e.getValue());
        }); 

    fre.forEach((k,v)->{
        //System.out.println("Item : " + k + " Count : " + v);
        ress.append(String.valueOf(k)+String.valueOf(v));
    });
    
    System.out.println(ress.toString());

POST data to a URL in PHP

Your question is not particularly clear, but in case you want to send POST data to a url without using a form, you can use either fsockopen or curl.

Here's a pretty good walkthrough of both

How to dynamically add a class to manual class names?

If you need style names which should appear according to the state condition, I prefer to use this construction:

<div className={'wrapper searchDiv' + (this.state.something === "a" ? " anotherClass" : "")'}>

Java Generics With a Class & an Interface - Together

You can't do it with "anonymous" type parameters (ie, wildcards that use ?), but you can do it with "named" type parameters. Simply declare the type parameter at method or class level.

import java.util.List;
interface A{}
interface B{}
public class Test<E extends B & A, T extends List<E>> {
    T t;
}

How to handle AccessViolationException

Microsoft: "Corrupted process state exceptions are exceptions that indicate that the state of a process has been corrupted. We do not recommend executing your application in this state.....If you are absolutely sure that you want to maintain your handling of these exceptions, you must apply the HandleProcessCorruptedStateExceptionsAttribute attribute"

Microsoft: "Use application domains to isolate tasks that might bring down a process."

The program below will protect your main application/thread from unrecoverable failures without risks associated with use of HandleProcessCorruptedStateExceptions and <legacyCorruptedStateExceptionsPolicy>

public class BoundaryLessExecHelper : MarshalByRefObject
{
    public void DoSomething(MethodParams parms, Action action)
    {
        if (action != null)
            action();
        parms.BeenThere = true; // example of return value
    }
}

public struct MethodParams
{
    public bool BeenThere { get; set; }
}

class Program
{
    static void InvokeCse()
    {
        IntPtr ptr = new IntPtr(123);
        System.Runtime.InteropServices.Marshal.StructureToPtr(123, ptr, true);
    }

    private static void ExecInThisDomain()
    {
        try
        {
            var o = new BoundaryLessExecHelper();
            var p = new MethodParams() { BeenThere = false };
            Console.WriteLine("Before call");

            o.DoSomething(p, CausesAccessViolation);
            Console.WriteLine("After call. param been there? : " + p.BeenThere.ToString()); //never stops here
        }
        catch (Exception exc)
        {
            Console.WriteLine($"CSE: {exc.ToString()}");
        }
        Console.ReadLine();
    }


    private static void ExecInAnotherDomain()
    {
        AppDomain dom = null;

        try
        {
            dom = AppDomain.CreateDomain("newDomain");
            var p = new MethodParams() { BeenThere = false };
            var o = (BoundaryLessExecHelper)dom.CreateInstanceAndUnwrap(typeof(BoundaryLessExecHelper).Assembly.FullName, typeof(BoundaryLessExecHelper).FullName);         
            Console.WriteLine("Before call");

            o.DoSomething(p, CausesAccessViolation);
            Console.WriteLine("After call. param been there? : " + p.BeenThere.ToString()); // never gets to here
        }
        catch (Exception exc)
        {
            Console.WriteLine($"CSE: {exc.ToString()}");
        }
        finally
        {
            AppDomain.Unload(dom);
        }

        Console.ReadLine();
    }


    static void Main(string[] args)
    {
        ExecInAnotherDomain(); // this will not break app
        ExecInThisDomain();  // this will
    }
}

Disable Buttons in jQuery Mobile

For disabling a button add css class disabled to it . write

$("button").addClass('disabled')

Error in spring application context schema

This happen to me after upgrade eclipse version. What works for me was clean the eclipse cache. Go to Window > Preferences > Network Connection > Cache > Remove All.

I hope this works for anyone!

Can I add color to bootstrap icons only using CSS?

The Bootstrap Glyphicons are fonts. This means it can be changed like any other text through CSS styling.

CSS:

<style>
   .glyphicon-plus {
       color: #F00; 
   }
</style>

HTML:

<span class="glyphicon glyphicon-plus"></span>

Example:

<!doctype html>
<html>
<head>
<title>Glyphicon Colors</title>
<link href="css/bootstrap.min.css" rel="stylesheet">
<style>
   .glyphicon-plus {
        color: #F00;    
   }
</style>
</head>

<body>
    <span class="glyphicon glyphicon-plus"></span>
</body>
</html>


Watch the course Up and Running with Bootstrap 3 by Jen Kramer, or watch the individual lesson on Overriding core CSS with custom styles.

How to override the properties of a CSS class using another CSS class

Just use !important it will help to override

background:none !important;

Although it is said to be a bad practice, !important can be useful for utility classes, you just need to use it responsibly, check this: When Using important is the right choice

Where does Android app package gets installed on phone

An application when installed on a device or on an emulator will install at:

/data/data/APP_PACKAGE_NAME

The APK itself is placed in the /data/app/ folder.

These paths, however, are in the System Partition and to access them, you will need to have root. This is for a device. On the emulator, you can see it in your logcat (DDMS) in the File Explorer tab

By the way, it only shows the package name that is defined in your Manifest.XML under the package="APP_PACKAGE_NAME" attribute. Any other packages you may have created in your project in Eclipse do not show up here.

How can I use async/await at the top level?

I can't seem to wrap my head around why this does not work.

Because main returns a promise; all async functions do.

At the top level, you must either:

  1. Use a top-level async function that never rejects (unless you want "unhandled rejection" errors), or

  2. Use then and catch, or

  3. (Coming soon!) Use top-level await, a proposal that has reached Stage 3 in the process that allows top-level use of await in a module.

#1 - Top-level async function that never rejects

(async () => {
    try {
        var text = await main();
        console.log(text);
    } catch (e) {
        // Deal with the fact the chain failed
    }
})();

Notice the catch; you must handle promise rejections / async exceptions, since nothing else is going to; you have no caller to pass them on to. If you prefer, you could do that on the result of calling it via the catch function (rather than try/catch syntax):

(async () => {
    var text = await main();
    console.log(text);
})().catch(e => {
    // Deal with the fact the chain failed
});

...which is a bit more concise (I like it for that reason).

Or, of course, don't handle errors and just allow the "unhandled rejection" error.

#2 - then and catch

main()
    .then(text => {
        console.log(text);
    })
    .catch(err => {
        // Deal with the fact the chain failed
    });

The catch handler will be called if errors occur in the chain or in your then handler. (Be sure your catch handler doesn't throw errors, as nothing is registered to handle them.)

Or both arguments to then:

main().then(
    text => {
        console.log(text);
    },
    err => {
        // Deal with the fact the chain failed
    }
);

Again notice we're registering a rejection handler. But in this form, be sure that neither of your then callbacks doesn't throw any errors, nothing is registered to handle them.

#3 top-level await in a module

You can't use await at the top level of a non-module script, but the top-level await proposal (Stage 3) allows you to use it at the top level of a module. It's similar to using a top-level async function wrapper (#1 above) in that you don't want your top-level code to reject (throw an error) because that will result in an unhandled rejection error. So unless you want to have that unhandled rejection when things go wrong, as with #1, you'd want to wrap your code in an error handler:

// In a module, once the top-level `await` proposal lands
try {
    var text = await main();
    console.log(text);
} catch (e) {
    // Deal with the fact the chain failed
}

Note that if you do this, any module that imports from your module will wait until the promise you're awaiting settles; when a module using top-level await is evaluated, it basically returns a promise to the module loader (like an async function does), which waits until that promise is settled before evaluating the bodies of any modules that depend on it.

What does ==$0 (double equals dollar zero) mean in Chrome Developer Tools?

$0 returns the most recently selected element or JavaScript object, $1 returns the second most recently selected one, and so on.

Refer : Command Line API Reference

what is the difference between GROUP BY and ORDER BY in sql

It should be noted GROUP BY is not always necessary as (at least in PostgreSQL, and likely in other SQL variants) you can use ORDER BY with a list and you can still use ASC or DESC per column...

SELECT name_first, name_last, dob 
FROM those_guys 
ORDER BY name_last ASC, name_first ASC, dob DESC;

Razor View Without Layout

Procedure 1 : Control Layouts rendering by using _ViewStart file in the root directory of the Views folder

This method is the simplest way for beginners to control Layouts rendering in your ASP.NET MVC application. We can identify the controller and render the Layouts as par controller, to do this we can write our code in _ViewStart file in the root directory of the Views folder. Following is an example shows how it can be done.

 @{
 var controller = HttpContext.Current.Request.RequestContext.RouteData.Values["Controller"].ToString();
 string cLayout = "";
 if (controller == "Webmaster") {
 cLayout = "~/Views/Shared/_WebmasterLayout.cshtml";
 }
 else {
 cLayout = "~/Views/Shared/_Layout.cshtml";
 }
 Layout = cLayout;
 }

Procedure 2 : Set Layout by Returning from ActionResult

One the the great feature of ASP.NET MVC is that, we can override the default layout rendering by returning the layout from the ActionResult. So, this is also a way to render different Layout in your ASP.NET MVC application. Following code sample show how it can be done.

public ActionResult Index()
{
 SampleModel model = new SampleModel();
 //Any Logic
 return View("Index", "_WebmasterLayout", model);
}

Procedure 3 : View - wise Layout (By defining Layout within each view on the top)

ASP.NET MVC provides us such a great feature & faxibility to override the default layout rendering by defining the layout on the view. To implement this we can write our code in following manner in each View.

@{
   Layout = "~/Views/Shared/_WebmasterLayout.cshtml";
}

Procedure 4 : Placing _ViewStart file in each of the directories

This is a very useful way to set different Layouts for each Controller in your ASP.NET MVC application. If we want to set default Layout for each directories than we can do this by putting _ViewStart file in each of the directories with the required Layout information as shown below:

@{
  Layout = "~/Views/Shared/_WebmasterLayout.cshtml";
}

Removing rounded corners from a <select> element in Chrome/Webkit

If you want square borders and still want the little expander arrow, I recommend this:

select.squarecorners{
     border: 0;
     outline: 1px solid #CCC;
     background-color: white;
}

How to completely remove node.js from Windows

Scenario: Removing NodeJS when Windows has no Program Entry for your Node installation

I ran into a problem where my version of NodeJS (0.10.26) could NOT be uninstalled nor removed, because Programs & Features in Windows 7 (aka Add/Remove Programs) had no record of my having installed NodeJS... so there was no option to remove it short of manually deleting registry keys and files.

Command to verify your NodeJS version: node --version

I attempted to install the newest recommended version of NodeJS, but it failed at the end of the installation process and rolled back. Multiple versions of NodeJS also failed, and the installer likewise rolled them back as well. I could not upgrade NodeJS from the command line as I did not have SUDO installed.

SOLUTION: After spending several hours troubleshooting the problem, including upgrading NPM, I decided to reinstall the EXACT version of NodeJS on my system, over the top of the existing installation.

That solution worked, and it reinstalled NodeJS without any errors. Better yet, it also added an official entry in Add/Remove Programs dialogue.

Now that Windows was aware of the forgotten NodeJS installation, I was able to uninstall my existing version of NodeJS completely. I then successfully installed the newest recommended release of NodeJS for the Windows platform (version 4.4.5 as of this writing) without a roll-back initiating.

It took me a while to reach sucess, so I am posting this in case it helps anyone else with a similar issue.

How to add trendline in python matplotlib dot (scatter) graphs?

as explained here

With help from numpy one can calculate for example a linear fitting.

# plot the data itself
pylab.plot(x,y,'o')

# calc the trendline
z = numpy.polyfit(x, y, 1)
p = numpy.poly1d(z)
pylab.plot(x,p(x),"r--")
# the line equation:
print "y=%.6fx+(%.6f)"%(z[0],z[1])

How to filter WooCommerce products by custom attribute

A plugin is probably your best option. Look in the wordpress plugins directory or google to see if you can find one. I found the one below and that seemed to work perfect.

https://wordpress.org/plugins/woocommerce-products-filter/

This one seems to do exactly what you are after

Setting state on componentDidMount()

The only reason that the linter complains about using setState({..}) in componentDidMount and componentDidUpdate is that when the component render the setState immediately causes the component to re-render. But the most important thing to note: using it inside these component's lifecycles is not an anti-pattern in React.

Please take a look at this issue. you will understand more about this topic. Thanks for reading my answer.

How to prevent a dialog from closing when a button is clicked

public class ComentarDialog extends DialogFragment{
private EditText comentario;

@Override
public Dialog onCreateDialog(Bundle savedInstanceState) {

    AlertDialog.Builder builder = new AlertDialog.Builder(getActivity());

    LayoutInflater inflater = LayoutInflater.from(getActivity());
    View v = inflater.inflate(R.layout.dialog_comentar, null);
    comentario = (EditText)v.findViewById(R.id.etxt_comentar_dialog);

    builder.setTitle("Comentar")
           .setView(v)
           .setPositiveButton("OK", null)
           .setNegativeButton("CANCELAR", new DialogInterface.OnClickListener() {
               public void onClick(DialogInterface dialog, int id) {

               }
           });

    return builder.create();
}

@Override
public void onStart() {
    super.onStart();

    //Obtenemos el AlertDialog
    AlertDialog dialog = (AlertDialog)getDialog();

    dialog.setCanceledOnTouchOutside(false);
    dialog.setCancelable(false);//Al presionar atras no desaparece

    //Implementamos el listener del boton OK para mostrar el toast
    dialog.getButton(AlertDialog.BUTTON_POSITIVE).setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            if(TextUtils.isEmpty(comentario.getText())){
               Toast.makeText(getActivity(), "Ingrese un comentario", Toast.LENGTH_SHORT).show();
               return;
            }
            else{
                ((AlertDialog)getDialog()).dismiss();
            }
        }
    });

    //Personalizamos
    Resources res = getResources();

    //Buttons
    Button positive_button = dialog.getButton(DialogInterface.BUTTON_POSITIVE);
    positive_button.setBackground(res.getDrawable(R.drawable.btn_selector_dialog));

    Button negative_button =  dialog.getButton(DialogInterface.BUTTON_NEGATIVE);
    negative_button.setBackground(res.getDrawable(R.drawable.btn_selector_dialog));

    int color = Color.parseColor("#304f5a");

    //Title
    int titleId = res.getIdentifier("alertTitle", "id", "android");
    View title = dialog.findViewById(titleId);
    if (title != null) {
        ((TextView) title).setTextColor(color);
    }

    //Title divider
    int titleDividerId = res.getIdentifier("titleDivider", "id", "android");
    View titleDivider = dialog.findViewById(titleDividerId);
    if (titleDivider != null) {
        titleDivider.setBackgroundColor(res.getColor(R.color.list_menu_divider));
    }
}
}

Get multiple elements by Id

An "id" Specifies a unique id for an element & a class Specifies one or more classnames for an element . So its better to use "Class" instead of "id".

how does Request.QueryString work?

The HttpRequest class represents the request made to the server and has various properties associated with it, such as QueryString.

The ASP.NET run-time parses a request to the server and populates this information for you.

Read HttpRequest Properties for a list of all the potential properties that get populated on you behalf by ASP.NET.

Note: not all properties will be populated, for instance if your request has no query string, then the QueryString will be null/empty. So you should check to see if what you expect to be in the query string is actually there before using it like this:

if (!String.IsNullOrEmpty(Request.QueryString["pID"]))
{
    // Query string value is there so now use it
    int thePID = Convert.ToInt32(Request.QueryString["pID"]);
}

JavaScript Object Id

Actually, you don't need to modify the object prototype. The following should work to 'obtain' unique ids for any object, efficiently enough.

var __next_objid=1;
function objectId(obj) {
    if (obj==null) return null;
    if (obj.__obj_id==null) obj.__obj_id=__next_objid++;
    return obj.__obj_id;
}

How do I validate a date string format in python?

I think the full validate function should look like this:

from datetime import datetime

def validate(date_text):
    try:
        if date_text != datetime.strptime(date_text, "%Y-%m-%d").strftime('%Y-%m-%d'):
            raise ValueError
        return True
    except ValueError:
        return False

Executing just

datetime.strptime(date_text, "%Y-%m-%d") 

is not enough because strptime method doesn't check that month and day of the month are zero-padded decimal numbers. For example

datetime.strptime("2016-5-3", '%Y-%m-%d')

will be executed without errors.

Disable developer mode extensions pop up in Chrome

Ruby based watir-webdriver use something like this:

browser=Watir::Browser.new( :chrome, :switches => %w[ --disable-extensions ] )

Setting the height of a DIV dynamically

Simplest I could come up...

function resizeResizeableHeight() {
    $('.resizableHeight').each( function() {
        $(this).outerHeight( $(this).parent().height() - ( $(this).offset().top - ( $(this).parent().offset().top + parseInt( $(this).parent().css('padding-top') ) ) ) )
    });
}

Now all you have to do is add the resizableHeight class to everything you want to autosize (to it's parent).

PHP: Calling another class' method

You would need to have an instance of ClassA within ClassB or have ClassB inherit ClassA

class ClassA {
    public function getName() {
      echo $this->name;
    }
}

class ClassB extends ClassA {
    public function getName() {
      parent::getName();
    }
}

Without inheritance or an instance method, you'd need ClassA to have a static method

class ClassA {
  public static function getName() {
    echo "Rawkode";
  }
}

--- other file ---

echo ClassA::getName();

If you're just looking to call the method from an instance of the class:

class ClassA {
  public function getName() {
    echo "Rawkode";
  }
}

--- other file ---

$a = new ClassA();
echo $a->getName();

Regardless of the solution you choose, require 'ClassA.php is needed.

Fastest way to compute entropy in Python

Uniformly distributed data (high entropy):

s=range(0,256)

Shannon entropy calculation step by step:

import collections
import math

# calculate probability for each byte as number of occurrences / array length
probabilities = [n_x/len(s) for x,n_x in collections.Counter(s).items()]
# [0.00390625, 0.00390625, 0.00390625, ...]

# calculate per-character entropy fractions
e_x = [-p_x*math.log(p_x,2) for p_x in probabilities]
# [0.03125, 0.03125, 0.03125, ...]

# sum fractions to obtain Shannon entropy
entropy = sum(e_x)
>>> entropy 
8.0

One-liner (assuming import collections):

def H(s): return sum([-p_x*math.log(p_x,2) for p_x in [n_x/len(s) for x,n_x in collections.Counter(s).items()]])

A proper function:

import collections
import math

def H(s):
    probabilities = [n_x/len(s) for x,n_x in collections.Counter(s).items()]
    e_x = [-p_x*math.log(p_x,2) for p_x in probabilities]    
    return sum(e_x)

Test cases - English text taken from CyberChef entropy estimator:

>>> H(range(0,256))
8.0
>>> H(range(0,64))
6.0
>>> H(range(0,128))
7.0
>>> H([0,1])
1.0
>>> H('Standard English text usually falls somewhere between 3.5 and 5')
4.228788210509104

SQL query to get the deadlocks in SQL SERVER 2008

You can use a deadlock graph and gather the information you require from the log file.

The only other way I could suggest is digging through the information by using EXEC SP_LOCK (Soon to be deprecated), EXEC SP_WHO2 or the sys.dm_tran_locks table.

SELECT  L.request_session_id AS SPID, 
    DB_NAME(L.resource_database_id) AS DatabaseName,
    O.Name AS LockedObjectName, 
    P.object_id AS LockedObjectId, 
    L.resource_type AS LockedResource, 
    L.request_mode AS LockType,
    ST.text AS SqlStatementText,        
    ES.login_name AS LoginName,
    ES.host_name AS HostName,
    TST.is_user_transaction as IsUserTransaction,
    AT.name as TransactionName,
    CN.auth_scheme as AuthenticationMethod
FROM    sys.dm_tran_locks L
    JOIN sys.partitions P ON P.hobt_id = L.resource_associated_entity_id
    JOIN sys.objects O ON O.object_id = P.object_id
    JOIN sys.dm_exec_sessions ES ON ES.session_id = L.request_session_id
    JOIN sys.dm_tran_session_transactions TST ON ES.session_id = TST.session_id
    JOIN sys.dm_tran_active_transactions AT ON TST.transaction_id = AT.transaction_id
    JOIN sys.dm_exec_connections CN ON CN.session_id = ES.session_id
    CROSS APPLY sys.dm_exec_sql_text(CN.most_recent_sql_handle) AS ST
WHERE   resource_database_id = db_id()
ORDER BY L.request_session_id

http://www.sqlmag.com/article/sql-server-profiler/gathering-deadlock-information-with-deadlock-graph

http://weblogs.sqlteam.com/mladenp/archive/2008/04/29/SQL-Server-2005-Get-full-information-about-transaction-locks.aspx

Telegram Bot - how to get a group chat id?

create a bot, or if already created set as follows:

has access to messages

apparently, regardless of how old/new the Telegram group is:

  1. add a bot to the group

  2. remove bot from the group

  3. add bot again to the group

  4. create a script file and run getUpdates method example:

    var vApiTokenTelegram = "1234567890:???>yg5GeL5PuItAOEhvdcPPELAOCCy3jBo"; // @?????Bot API token
    var vUrlTelegram = "https://api.telegram.org/bot" + vApiTokenTelegram;

    function getUpdates() {
        var response = UrlFetchApp.fetch(vUrlTelegram + "/getUpdates");
        console.log(response.getContentText());
    }
  1. function shall log to the console the following:
[20-04-21 00:46:11:130 PDT] {"ok":true,"result":[{"update_id":81329501,
"message":{"message_id":975,"from":{"id":962548471,"is_bot":false,"first_name":"Trajano","last_name":"Roberto","username":"TrajanoRoberto","language_code":"en"},"chat":{"id":-1001202656383,"title":"R\u00e1dioRN - A voz da na\u00e7\u00e3o!","type":"supergroup"},"date":1587454914,"left_chat_participant":{"id":1215098445,"is_bot":true,"first_name":"MediaFlamengoRawBot","username":"MediaFlamengoRawBot"},"left_chat_member":{"id":1215098445,"is_bot":true,"first_name":"MediaFlamengoRawBot","username":"MediaFlamengoRawBot"}}},{"update_id":81329502,
"message":{"message_id":976,"from":{"id":962548471,"is_bot":false,"first_name":"Trajano","last_name":"Roberto","username":"TrajanoRoberto","language_code":"en"},"chat":{"id":-1001202656383,"title":"R\u00e1dioRN - A voz da na\u00e7\u00e3o!","type":"supergroup"},"date":1587454932,"new_chat_participant":{"id":1215098445,"is_bot":true,"first_name":"MediaFlamengoRawBot","username":"MediaFlamengoRawBot"},"new_chat_member":{"id":1215098445,"is_bot":true,"first_name":"MediaFlamengoRawBot","username":"MediaFlamengoRawBot"},"new_chat_members":[{"id":1215098445,"is_bot":true,"first_name":"MediaFlamengoRawBot","username":"MediaFlamengoRawBot"}]}}]}
  1. Telegram group chat_id can be extracted from above message "chat":{"id":-1001202656383,"title"

How to remove MySQL completely with config and library files?

With the command:

sudo apt-get remove --purge mysql\*

you can delete anything related to packages named mysql. Those commands are only valid on debian / debian-based linux distributions (Ubuntu for example).

You can list all installed mysql packages with the command:

sudo dpkg -l | grep -i mysql

For more cleanup of the package cache, you can use the command:

sudo apt-get clean

Also, remember to use the command:

sudo updatedb

Otherwise the "locate" command will display old data.

To install mysql again, use the following command:

sudo apt-get install libmysqlclient-dev mysql-client

This will install the mysql client, libmysql and its headers files.

To install the mysql server, use the command:

sudo apt-get install mysql-server

How to set background color of HTML element using css properties in JavaScript

KISS Answer:

document.getElementById('element').style.background = '#DD00DD';

AttributeError: 'module' object has no attribute 'urlopen'

Use six module to make you code compatible between python2 and python3

urllib.request.urlopen("<your-url>")```

What does this GCC error "... relocation truncated to fit..." mean?

Often, this error means your program is too large, and often it's too large because it contains one or more very large data objects. For example,

char large_array[1ul << 31];
int other_global;
int main(void) { return other_global; }

will produce a "relocation truncated to fit" error on x86-64/Linux, if compiled in the default mode and without optimization. (If you turn on optimization, it could, at least theoretically, figure out that large_array is unused and/or that other_global is never written, and thus generate code that doesn't trigger the problem.)

What's going on is that, by default, GCC uses its "small code model" on this architecture, in which all of the program's code and statically allocated data must fit into the lowest 2GB of the address space. (The precise upper limit is something like 2GB - 2MB, because the very lowest 2MB of any program's address space is permanently unusable. If you are compiling a shared library or position-independent executable, all of the code and data must still fit into two gigabytes, but they're not nailed to the bottom of the address space anymore.) large_array consumes all of that space by itself, so other_global is assigned an address above the limit, and the code generated for main cannot reach it. You get a cryptic error from the linker, rather than a helpful "large_array is too large" error from the compiler, because in more complex cases the compiler can't know that other_global will be out of reach, so it doesn't even try for the simple cases.

Most of the time, the correct response to getting this error is to refactor your program so that it doesn't need gigantic static arrays and/or gigabytes of machine code. However, if you really have to have them for some reason, you can use the "medium" or "large" code models to lift the limits, at the price of somewhat less efficient code generation. These code models are x86-64-specific; something similar exists for most other architectures, but the exact set of "models" and the associated limits will vary. (On a 32-bit architecture, for instance, you might have a "small" model in which the total amount of code and data was limited to something like 224 bytes.)

Running Git through Cygwin from Windows

call your (windows-)git with cygpath as parameter, in order to convert the "calling path". I m confused why that should be a problem.

Xcode 4 - build output directory

You can always find the build directory by looking in the build log viewer, and copying the path there into a terminal window.

I use this to analyze my iOS .app bundles before they get installed to make sure no stray files are being included.

Max retries exceeded with URL in requests

What happened here is that itunes server refuses your connection (you're sending too many requests from same ip address in short period of time)

Max retries exceeded with url: /in/app/adobe-reader/id469337564?mt=8

error trace is misleading it should be something like "No connection could be made because the target machine actively refused it".

There is an issue at about python.requests lib at Github, check it out here

To overcome this issue (not so much an issue as it is misleading debug trace) you should catch connection related exceptions like so:

try:
    page1 = requests.get(ap)
except requests.exceptions.ConnectionError:
    r.status_code = "Connection refused"

Another way to overcome this problem is if you use enough time gap to send requests to server this can be achieved by sleep(timeinsec) function in python (don't forget to import sleep)

from time import sleep

All in all requests is awesome python lib, hope that solves your problem.

how do I check in bash whether a file was created more than x time ago?

Although ctime isn't technically the time of creation, it quite often is.

Since ctime it isn't affected by changes to the contents of the file, it's usually only updated when the file is created. And yes - I can hear you all screaming - it's also updated if you change the access permissions or ownership... but generally that's something that's done once, usually at the same time you put the file there.

Personally I always use mtime for everything, and I imagine that is what you want. But anyway... here's a rehash of Guss's "unattractive" bash, in an easy to use function.

#!/bin/bash
function age() {
   local filename=$1
   local changed=`stat -c %Y "$filename"`
   local now=`date +%s`
   local elapsed

   let elapsed=now-changed
   echo $elapsed
}

file="/"
echo The age of $file is $(age "$file") seconds.

Using css transform property in jQuery

If you're using jquery, jquery.transit is very simple and powerful lib that allows you to make your transformation while handling cross-browser compability for you. It can be as simple as this : $("#element").transition({x:'90px'}).

Take it from this link : http://ricostacruz.com/jquery.transit/

Test if remote TCP port is open from a shell script

As pointed by B. Rhodes, nc (netcat) will do the job. A more compact way to use it:

nc -z <host> <port>

That way nc will only check if the port is open, exiting with 0 on success, 1 on failure.

For a quick interactive check (with a 5 seconds timeout):

nc -z -v -w5 <host> <port>

How to set up default schema name in JPA configuration?

For others who use spring-boot, java based configuration,

I set the schema value in application.properties

spring.jpa.properties.hibernate.dialect=...
spring.jpa.properties.hibernate.default_schema=...

Executing Batch File in C#

This should work. You could try to dump out the contents of the output and error streams in order to find out what's happening:

static void ExecuteCommand(string command)
{
    int exitCode;
    ProcessStartInfo processInfo;
    Process process;

    processInfo = new ProcessStartInfo("cmd.exe", "/c " + command);
    processInfo.CreateNoWindow = true;
    processInfo.UseShellExecute = false;
    // *** Redirect the output ***
    processInfo.RedirectStandardError = true;
    processInfo.RedirectStandardOutput = true;

    process = Process.Start(processInfo);
    process.WaitForExit();

    // *** Read the streams ***
    // Warning: This approach can lead to deadlocks, see Edit #2
    string output = process.StandardOutput.ReadToEnd();
    string error = process.StandardError.ReadToEnd();

    exitCode = process.ExitCode;

    Console.WriteLine("output>>" + (String.IsNullOrEmpty(output) ? "(none)" : output));
    Console.WriteLine("error>>" + (String.IsNullOrEmpty(error) ? "(none)" : error));
    Console.WriteLine("ExitCode: " + exitCode.ToString(), "ExecuteCommand");
    process.Close();
}

static void Main()
{
    ExecuteCommand("echo testing");
}   

* EDIT *

Given the extra information in your comment below, I was able to recreate the problem. There seems to be some security setting that results in this behaviour (haven't investigated that in detail).

This does work if the batch file is not located in C:\Windows\System32. Try moving it to some other location, e.g. the location of your executable. Note that keeping custom batch files or executables in the Windows directory is bad practice anyway.

* EDIT 2 * It turns out that if the streams are read synchronously, a deadlock can occur, either by reading synchronously before WaitForExit or by reading both stderr and stdout synchronously one after the other.

This should not happen if using the asynchronous read methods instead, as in the following example:

static void ExecuteCommand(string command)
{
    var processInfo = new ProcessStartInfo("cmd.exe", "/c " + command);
    processInfo.CreateNoWindow = true;
    processInfo.UseShellExecute = false;
    processInfo.RedirectStandardError = true;
    processInfo.RedirectStandardOutput = true;

    var process = Process.Start(processInfo);

    process.OutputDataReceived += (object sender, DataReceivedEventArgs e) =>
        Console.WriteLine("output>>" + e.Data);
    process.BeginOutputReadLine();

    process.ErrorDataReceived += (object sender, DataReceivedEventArgs e) =>
        Console.WriteLine("error>>" + e.Data);
    process.BeginErrorReadLine();

    process.WaitForExit();

    Console.WriteLine("ExitCode: {0}", process.ExitCode);
    process.Close();
}

How to upload files on server folder using jsp

You can only use absolute path http://grand-shopping.com/<"some folder"> is not an absolute path.

Either you can use a path inside the application which is vurneable or you can use server specific path like in

windows -> C:/Users/puneet verma/Downloads/
linux -> /opt/Downloads/

How to create an array containing 1...N

Improvising on the above:

var range = function (n) {
  return Array(n).join().split(',').map(function(e, i) { return i; });
}  

one can get the following options:

1) Array.init to value v

var arrayInitTo = function (n,v) {
  return Array(n).join().split(',').map(function() { return v; });
}; 

2) get a reversed range:

var rangeRev = function (n) {
  return Array(n).join().split(',').map(function() { return n--; });
};

Amazon Interview Question: Design an OO parking lot

Here is a quick start to get the gears turning...

ParkingLot is a class.

ParkingSpace is a class.

ParkingSpace has an Entrance.

Entrance has a location or more specifically, distance from Entrance.

ParkingLotSign is a class.

ParkingLot has a ParkingLotSign.

ParkingLot has a finite number of ParkingSpaces.

HandicappedParkingSpace is a subclass of ParkingSpace.

RegularParkingSpace is a subclass of ParkingSpace.

CompactParkingSpace is a subclass of ParkingSpace.

ParkingLot keeps array of ParkingSpaces, and a separate array of vacant ParkingSpaces in order of distance from its Entrance.

ParkingLotSign can be told to display "full", or "empty", or "blank/normal/partially occupied" by calling .Full(), .Empty() or .Normal()

Parker is a class.

Parker can Park().

Parker can Unpark().

Valet is a subclass of Parker that can call ParkingLot.FindVacantSpaceNearestEntrance(), which returns a ParkingSpace.

Parker has a ParkingSpace.

Parker can call ParkingSpace.Take() and ParkingSpace.Vacate().

Parker calls Entrance.Entering() and Entrance.Exiting() and ParkingSpace notifies ParkingLot when it is taken or vacated so that ParkingLot can determine if it is full or not. If it is newly full or newly empty or newly not full or empty, it should change the ParkingLotSign.Full() or ParkingLotSign.Empty() or ParkingLotSign.Normal().

HandicappedParker could be a subclass of Parker and CompactParker a subclass of Parker and RegularParker a subclass of Parker. (might be overkill, actually.)

In this solution, it is possible that Parker should be renamed to be Car.

Nodejs convert string into UTF-8

When you want to change the encoding you always go from one into another. So you might go from Mac Roman to UTF-8 or from ASCII to UTF-8.

It's as important to know the desired output encoding as the current source encoding. For example if you have Mac Roman and you decode it from UTF-16 to UTF-8 you'll just make it garbled.

If you want to know more about encoding this article goes into a lot of details:

What Every Programmer Absolutely, Positively Needs To Know About Encodings And Character Sets To Work With Text

The npm pacakge encoding which uses node-iconv or iconv-lite should allow you to easily specify which source and output encoding you want:

var resultBuffer = encoding.convert(nameString, 'ASCII', 'UTF-8');

How do I copy an entire directory of files into an existing directory using Python?

Here is my pass at the problem. I modified the source code for copytree to keep the original functionality, but now no error occurs when the directory already exists. I also changed it so it doesn't overwrite existing files but rather keeps both copies, one with a modified name, since this was important for my application.

import shutil
import os


def _copytree(src, dst, symlinks=False, ignore=None):
    """
    This is an improved version of shutil.copytree which allows writing to
    existing folders and does not overwrite existing files but instead appends
    a ~1 to the file name and adds it to the destination path.
    """

    names = os.listdir(src)
    if ignore is not None:
        ignored_names = ignore(src, names)
    else:
        ignored_names = set()

    if not os.path.exists(dst):
        os.makedirs(dst)
        shutil.copystat(src, dst)
    errors = []
    for name in names:
        if name in ignored_names:
            continue
        srcname = os.path.join(src, name)
        dstname = os.path.join(dst, name)
        i = 1
        while os.path.exists(dstname) and not os.path.isdir(dstname):
            parts = name.split('.')
            file_name = ''
            file_extension = parts[-1]
            # make a new file name inserting ~1 between name and extension
            for j in range(len(parts)-1):
                file_name += parts[j]
                if j < len(parts)-2:
                    file_name += '.'
            suffix = file_name + '~' + str(i) + '.' + file_extension
            dstname = os.path.join(dst, suffix)
            i+=1
        try:
            if symlinks and os.path.islink(srcname):
                linkto = os.readlink(srcname)
                os.symlink(linkto, dstname)
            elif os.path.isdir(srcname):
                _copytree(srcname, dstname, symlinks, ignore)
            else:
                shutil.copy2(srcname, dstname)
        except (IOError, os.error) as why:
            errors.append((srcname, dstname, str(why)))
        # catch the Error from the recursive copytree so that we can
        # continue with other files
        except BaseException as err:
            errors.extend(err.args[0])
    try:
        shutil.copystat(src, dst)
    except WindowsError:
        # can't copy file access times on Windows
        pass
    except OSError as why:
        errors.extend((src, dst, str(why)))
    if errors:
        raise BaseException(errors)

Java GUI frameworks. What to choose? Swing, SWT, AWT, SwingX, JGoodies, JavaFX, Apache Pivot?

I've been quite happy with Swing for the desktop applications I've been involved in. However, I do share your view on Swing not offering advanced components. What I've done in these cases is to go for JIDE. It's not free, but not that pricey either and it gives you a whole lot more tools under your belt. Specifically, they do offer a filterable TreeTable.

Failed to add the host to the list of know hosts

Shouldn't known_hosts be a flat file, not a directory?

If that's not the problem, then this page on Github might be of some help. Try using SSH with the -v or -vv flag to see verbose error messages. It might give you a better idea of what's failing.

Fully change package name including company domain

This might help you - 1) Open a file of your package. 2) Android Studio displays the breadcrumbs of the file, above the opened file. On the package you want renamed: Right click > Refactor > Rename.

enter image description here

How do I format a Microsoft JSON date?

For those using Newtonsoft Json.NET, read up on how to do it via Native JSON in IE8, Firefox 3.5 plus Json.NET.

Also the documentation on changing the format of dates written by Json.NET is useful: Serializing Dates with Json.NET

For those that are too lazy, here are the quick steps. As JSON has a loose DateTime implementation, you need to use the IsoDateTimeConverter(). Note that since Json.NET 4.5 the default date format is ISO so the code below isn't needed.

string jsonText = JsonConvert.SerializeObject(p, new IsoDateTimeConverter());

The JSON will come through as

"fieldName": "2009-04-12T20:44:55"

Finally, some JavaScript to convert the ISO date to a JavaScript date:

function isoDateReviver(value) {
  if (typeof value === 'string') {
    var a = /^(\d{4})-(\d{2})-(\d{2})T(\d{2}):(\d{2}):(\d{2}(?:\.\d*)?)(?:([\+-])(\d{2})\:(\d{2}))?Z?$/.exec(value);
      if (a) {
        var utcMilliseconds = Date.UTC(+a[1], +a[2] - 1, +a[3], +a[4], +a[5], +a[6]);
        return new Date(utcMilliseconds);
      }
  }
  return value;
}

I used it like this

$("<span />").text(isoDateReviver(item.fieldName).toLocaleString()).appendTo("#" + divName);

SQL select max(date) and corresponding value

There's no easy way to do this, but something like this will work:

SELECT ET.TrainingID, 
  ET.CompletedDate, 
  ET.Notes
FROM 
HR_EmployeeTrainings ET
inner join
(
  select TrainingID, Max(CompletedDate) as CompletedDate
  FROM HR_EmployeeTrainings
  WHERE (ET.AvantiRecID IS NULL OR ET.AvantiRecID = @avantiRecID)
  GROUP BY AvantiRecID, TrainingID  
) ET2 
  on ET.TrainingID = ET2.TrainingID
  and ET.CompletedDate = ET2.CompletedDate

Using variables inside a bash heredoc

In answer to your first question, there's no parameter substitution because you've put the delimiter in quotes - the bash manual says:

The format of here-documents is:

      <<[-]word
              here-document
      delimiter

No parameter expansion, command substitution, arithmetic expansion, or pathname expansion is performed on word. If any characters in word are quoted, the delimiter is the result of quote removal on word, and the lines in the here-document are not expanded. If word is unquoted, all lines of the here-document are subjected to parameter expansion, command substitution, and arithmetic expansion. [...]

If you change your first example to use <<EOF instead of << "EOF" you'll find that it works.

In your second example, the shell invokes sudo only with the parameter cat, and the redirection applies to the output of sudo cat as the original user. It'll work if you try:

sudo sh -c "cat > /path/to/outfile" <<EOT
my text...
EOT

Where do I configure log4j in a JUnit test class?

I use system properties in log4j.xml:

...
<param name="File" value="${catalina.home}/logs/root.log"/>
...

and start tests with:

<plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-surefire-plugin</artifactId>
    <version>2.16</version>
    <configuration>
        <systemProperties>
            <property>
                <name>catalina.home</name>
                <value>${project.build.directory}</value>
            </property>
        </systemProperties>
    </configuration>
</plugin>

How do you round a float to 2 decimal places in JRuby?

sprintf('%.2f', number) is a cryptic, but very powerful way of formatting numbers. The result is always a string, but since you're rounding I assume you're doing it for presentation purposes anyway. sprintf can format any number almost any way you like, and lots more.

Full sprintf documentation: http://www.ruby-doc.org/core-2.0.0/Kernel.html#method-i-sprintf

Code for a simple JavaScript countdown timer?

You can do as follows with pure JS. You just need to provide the function with the number of seconds and it will do the rest.

_x000D_
_x000D_
var insertZero = n => n < 10 ? "0"+n : ""+n,_x000D_
   displayTime = n => n ? time.textContent = insertZero(~~(n/3600)%3600) + ":" +_x000D_
                                             insertZero(~~(n/60)%60) + ":" +_x000D_
                                             insertZero(n%60)_x000D_
                        : time.textContent = "IGNITION..!",_x000D_
 countDownFrom = n => (displayTime(n), setTimeout(_ => n ? sid = countDownFrom(--n)_x000D_
                                                         : displayTime(n), 1000)),_x000D_
           sid;_x000D_
countDownFrom(3610);_x000D_
setTimeout(_ => clearTimeout(sid),20005);
_x000D_
<div id="time"></div>
_x000D_
_x000D_
_x000D_

How do you develop Java Servlets using Eclipse?

You need to install a plugin, There is a free one from the eclipse foundation called the Web Tools Platform. It has all the development functionality that you'll need.

You can get the Java EE Edition of eclipse with has it pre-installed.

To create and run your first servlet:

  1. New... Project... Dynamic Web Project.
  2. Right click the project... New Servlet.
  3. Write some code in the doGet() method.
  4. Find the servers view in the Java EE perspective, it's usually one of the tabs at the bottom.
  5. Right click in there and select new Server.
  6. Select Tomcat X.X and a wizard will point you to finding the installation.
  7. Right click the server you just created and select Add and Remove... and add your created web project.
  8. Right click your servlet and select Run > Run on Server...

That should do it for you. You can use ant to build here if that's what you'd like but eclipse will actually do the build and automatically deploy the changes to the server. With Tomcat you might have to restart it every now and again depending on the change.

Create empty file using python

Of course there IS a way to create files without opening. It's as easy as calling os.mknod("newfile.txt"). The only drawback is that this call requires root privileges on OSX.

How to go back (ctrl+z) in vi/vim

On a mac you can also use command Z and that will go undo. I'm not sure why, but sometimes it stops, and if your like me and vimtutor is on the bottom of that long list of things you need to learn, than u can just close the window and reopen it and should work fine.

Not showing placeholder for input type="date" field

Based on deadproxor and Alessio answers, I would try only using CSS:

input[type="date"]::before{
    color: #999;
    content: attr(placeholder) ": ";
}
input[type="date"]:focus::before {
    content: "" !important;
}

And if you need to make the placeholder invisible after writing something in the input, we could try using the :valid and :invalid selectors, if your input is a required one.

EDIT

Here the code if you are using required in your input:

_x000D_
_x000D_
input[type="date"]::before {_x000D_
 color: #999999;_x000D_
 content: attr(placeholder);_x000D_
}_x000D_
input[type="date"] {_x000D_
 color: #ffffff;_x000D_
}_x000D_
input[type="date"]:focus,_x000D_
input[type="date"]:valid {_x000D_
 color: #666666;_x000D_
}_x000D_
input[type="date"]:focus::before,_x000D_
input[type="date"]:valid::before {_x000D_
 content: "" !important;_x000D_
}
_x000D_
<input type="date" placeholder="Date" required>
_x000D_
_x000D_
_x000D_

Importing the private-key/public-certificate pair in the Java KeyStore

With your private key and public certificate, you need to create a PKCS12 keystore first, then convert it into a JKS.

# Create PKCS12 keystore from private key and public certificate.
openssl pkcs12 -export -name myservercert -in selfsigned.crt -inkey server.key -out keystore.p12

# Convert PKCS12 keystore into a JKS keystore
keytool -importkeystore -destkeystore mykeystore.jks -srckeystore keystore.p12 -srcstoretype pkcs12 -alias myservercert

To verify the contents of the JKS, you can use this command:

keytool -list -v -keystore mykeystore.jks

If this was not a self-signed certificate, you would probably want to follow this step with importing the certificate chain leading up to the trusted CA cert.

Determine the number of NA values in a column

A quick and easy Tidyverse solution to get a NA count for all columns is to use summarise_all() which I think makes a much easier to read solution than using purrr or sapply

library(tidyverse)
# Example data
df <- tibble(col1 = c(1, 2, 3, NA), 
             col2 = c(NA, NA, "a", "b"))

df %>% summarise_all(~ sum(is.na(.)))
#> # A tibble: 1 x 2
#>    col1  col2
#>   <int> <int>
#> 1     1     2

:before and background-image... should it work?

@michi; define height in your before pseudo class

CSS:

#videos-part:before{
    width: 16px;
    content: " ";
    background-image: url(/img/border-left3.png);
    position: absolute;
    left: -16px;
    top: -6px;
    height:20px;
}

How to rotate the background image in the container?

Update 2020, May:

Setting position: absolute and then transform: rotate(45deg) will provide a background:

_x000D_
_x000D_
div {_x000D_
  height: 200px;_x000D_
  width: 200px;_x000D_
  outline: 2px dashed slateBlue;_x000D_
  overflow: hidden;_x000D_
}_x000D_
div img {_x000D_
  position: absolute;_x000D_
  transform: rotate(45deg);_x000D_
  z-index: -1;_x000D_
  top: 40px;_x000D_
  left: 40px;_x000D_
}
_x000D_
<div>_x000D_
  <img src="https://placekitten.com/120/120" />_x000D_
  <h1>Hello World!</h1>_x000D_
</div>
_x000D_
_x000D_
_x000D_

Original Answer:

In my case, the image size is not so large that I cannot have a rotated copy of it. So, the image has been rotated with photoshop. An alternative to photoshop for rotating images is online tool too for rotating images. Once rotated, I'm working with the rotated-image in the background property.

div.with-background {
    background-image: url(/img/rotated-image.png);
    background-size:     contain;
    background-repeat:   no-repeat;
    background-position: top center;
}

Good Luck...

Print the contents of a DIV

i used Bill Paetzke answer to print a div contain images but it didn't work with google chrome

i just needed to add this line myWindow.onload=function(){ to make it work and here is the full code

<html>
<head>
    <script type="text/javascript" src="http://jqueryjs.googlecode.com/files/jquery-1.3.1.min.js"> </script>
    <script type="text/javascript">
        function PrintElem(elem) {
            Popup($(elem).html());
        }

        function Popup(data) {
            var myWindow = window.open('', 'my div', 'height=400,width=600');
            myWindow.document.write('<html><head><title>my div</title>');
            /*optional stylesheet*/ //myWindow.document.write('<link rel="stylesheet" href="main.css" type="text/css" />');
            myWindow.document.write('</head><body >');
            myWindow.document.write(data);
            myWindow.document.write('</body></html>');
            myWindow.document.close(); // necessary for IE >= 10

            myWindow.onload=function(){ // necessary if the div contain images

                myWindow.focus(); // necessary for IE >= 10
                myWindow.print();
                myWindow.close();
            };
        }
    </script>
</head>
<body>
    <div id="myDiv">
        This will be printed.
        <img src="image.jpg"/>
    </div>
    <div>
        This will not be printed.
    </div>
    <div id="anotherDiv">
        Nor will this.
    </div>
    <input type="button" value="Print Div" onclick="PrintElem('#myDiv')" />
</body>
</html>

also if someone just need to print a div with id he doesn't need to load jquery

here is pure javascript code to do this

<html>
<head>
    <script type="text/javascript">
        function PrintDiv(id) {
            var data=document.getElementById(id).innerHTML;
            var myWindow = window.open('', 'my div', 'height=400,width=600');
            myWindow.document.write('<html><head><title>my div</title>');
            /*optional stylesheet*/ //myWindow.document.write('<link rel="stylesheet" href="main.css" type="text/css" />');
            myWindow.document.write('</head><body >');
            myWindow.document.write(data);
            myWindow.document.write('</body></html>');
            myWindow.document.close(); // necessary for IE >= 10

            myWindow.onload=function(){ // necessary if the div contain images

                myWindow.focus(); // necessary for IE >= 10
                myWindow.print();
                myWindow.close();
            };
        }
    </script>
</head>
<body>
    <div id="myDiv">
        This will be printed.
        <img src="image.jpg"/>
    </div>
    <div>
        This will not be printed.
    </div>
    <div id="anotherDiv">
        Nor will this.
    </div>
    <input type="button" value="Print Div" onclick="PrintDiv('myDiv')" />
</body>
</html>

i hope this can help someone

Android Transparent TextView?

<TextView android:alpha="0.3" ..., for example.

How to add parameters to a HTTP GET request in Android?

If you have constant URL I recommend use simplified http-request built on apache http.

You can build your client as following:

private filan static HttpRequest<YourResponseType> httpRequest = 
                   HttpRequestBuilder.createGet(yourUri,YourResponseType)
                   .build();

public void send(){
    ResponseHendler<YourResponseType> rh = 
         httpRequest.execute(param1, value1, param2, value2);

    handler.ifSuccess(this::whenSuccess).otherwise(this::whenNotSuccess);
}

public void whenSuccess(ResponseHendler<YourResponseType> rh){
     rh.ifHasContent(content -> // your code);
}

public void whenSuccess(ResponseHendler<YourResponseType> rh){
   LOGGER.error("Status code: " + rh.getStatusCode() + ", Error msg: " + rh.getErrorText());
}

Note: There are many useful methods to manipulate your response.

Entity Framework Provider type could not be loaded?

I was working on the Contoso University tutorial offline and encountered the same issue when trying to create my first controller using EF. I had to use the Package Manager Console to load EF from the nuget cache and created a connection string to my local instance of SQL Server, my point here is my webConfig setting for EF may not be set as you all out there but I was able to resolve my issue by completely deleting the "providers" section within "entityFramework"

Robert

How do you find the sum of all the numbers in an array in Java?

It depends. How many numbers are you adding? Testing many of the above suggestions:

import java.text.NumberFormat;
import java.util.Arrays;
import java.util.Locale;

public class Main {

    public static final NumberFormat FORMAT = NumberFormat.getInstance(Locale.US);

    public static long sumParallel(int[] array) {
        final long start = System.nanoTime();
        int sum = Arrays.stream(array).parallel().reduce(0,(a,b)->  a + b);
        final long end = System.nanoTime();
        System.out.println(sum);
        return  end - start;
    }

    public static long sumStream(int[] array) {
        final long start = System.nanoTime();
        int sum = Arrays.stream(array).reduce(0,(a,b)->  a + b);
        final long end = System.nanoTime();
        System.out.println(sum);
        return  end - start;
    }

    public static long sumLoop(int[] array) {
        final long start = System.nanoTime();
        int sum = 0;
        for (int v: array) {
            sum += v;
        }
        final long end = System.nanoTime();
        System.out.println(sum);
        return  end - start;
    }

    public static long sumArray(int[] array) {
        final long start = System.nanoTime();
        int sum = Arrays.stream(array) .sum();
        final long end = System.nanoTime();
        System.out.println(sum);
        return  end - start;
    }

    public static long sumStat(int[] array) {
        final long start = System.nanoTime();
        int sum = 0;
        final long end = System.nanoTime();
        System.out.println(sum);
        return  end - start;
    }


    public static void test(int[] nums) {
        System.out.println("------");
        System.out.println(FORMAT.format(nums.length) + " numbers");
        long p = sumParallel(nums);
        System.out.println("parallel " + FORMAT.format(p));
        long s = sumStream(nums);
        System.out.println("stream " +  FORMAT.format(s));
        long ar = sumArray(nums);
        System.out.println("arrays " +  FORMAT.format(ar));
        long lp = sumLoop(nums);
        System.out.println("loop " +  FORMAT.format(lp));

    }

    public static void testNumbers(int howmany) {
        int[] nums = new int[howmany];
        for (int i =0; i < nums.length;i++) {
            nums[i] = (i + 1)%100;
        }
        test(nums);
    }

    public static void main(String[] args) {
        testNumbers(3);
        testNumbers(300);
        testNumbers(3000);
        testNumbers(30000);
        testNumbers(300000);
        testNumbers(3000000);
        testNumbers(30000000);
        testNumbers(300000000);
    }
}

I found, using an 8 core, 16 G Ubuntu18 machine, the loop was fastest for smaller values and the parallel for larger. But of course it would depend on the hardware you're running:

------
3 numbers
6
parallel 4,575,234
6
stream 209,849
6
arrays 251,173
6
loop 576
------
300 numbers
14850
parallel 671,428
14850
stream 73,469
14850
arrays 71,207
14850
loop 4,958
------
3,000 numbers
148500
parallel 393,112
148500
stream 306,240
148500
arrays 335,795
148500
loop 47,804
------
30,000 numbers
1485000
parallel 794,223
1485000
stream 1,046,927
1485000
arrays 366,400
1485000
loop 459,456
------
300,000 numbers
14850000
parallel 4,715,590
14850000
stream 1,369,509
14850000
arrays 1,296,287
14850000
loop 1,327,592
------
3,000,000 numbers
148500000
parallel 3,996,803
148500000
stream 13,426,933
148500000
arrays 13,228,364
148500000
loop 1,137,424
------
30,000,000 numbers
1485000000
parallel 32,894,414
1485000000
stream 131,924,691
1485000000
arrays 131,689,921
1485000000
loop 9,607,527
------
300,000,000 numbers
1965098112
parallel 338,552,816
1965098112
stream 1,318,649,742
1965098112
arrays 1,308,043,340
1965098112
loop 98,986,436

Java: Difference between the setPreferredSize() and setSize() methods in components

setSize() or setBounds() can be used when no layout manager is being used.

However, if you are using a layout manager you can provide hints to the layout manager using the setXXXSize() methods like setPreferredSize() and setMinimumSize() etc.

And be sure that the component's container uses a layout manager that respects the requested size. The FlowLayout, GridBagLayout, and SpringLayout managers use the component's preferred size (the latter two depending on the constraints you set), but BorderLayout and GridLayout usually don't.If you specify new size hints for a component that's already visible, you need to invoke the revalidate method on it to make sure that its containment hierarchy is laid out again. Then invoke the repaint method.

How to convert from int to string in objective c: example code

== shouldn't be used to compare objects in your if. For NSString use isEqualToString: to compare them.

How to fix 'Unchecked runtime.lastError: The message port closed before a response was received' chrome issue?

In my case it was a breakpoint set in my own page source. If I removed or disabled the breakpoint then the error would clear up.

The breakpoint was in a moderately complex chunk of rendering code. Other breakpoints in different parts of the page had no such effect. I was not able to work out a simple test case that always trigger this error.

How to force garbage collector to run?

Since I'm too low reputation to comment, I will post this as an answer since it saved me after hours of struggeling and it may help somebody else:

As most people state GC.Collect(); is NOT recommended to do this normally, except in edge cases. As an example of this running garbage collection was exactly the solution to my scenario.

My program runs a long running operation on a file in a thread and afterwards deletes the file from the main thread. However: when the file operation throws an exception .NET does NOT release the filelock until the garbage is actually collected, EVEN when the long running task is encapsulated in a using statement. Therefore the program has to force garbage collection before attempting to delete the file.

In code:

        var returnvalue = 0;
        using (var t = Task.Run(() => TheTask(args, returnvalue)))
        {
            //TheTask() opens a file and then throws an exception. The exception itself is handled within the task so it does return a result (the errorcode)
            returnvalue = t.Result;
        }
        //Even though at this point the Thread is closed the file is not released untill garbage is collected
        System.GC.Collect();
        DeleteLockedFile();

How to resize image (Bitmap) to a given size?

 Bitmap yourBitmap;
 Bitmap resized = Bitmap.createScaledBitmap(yourBitmap, newWidth, newHeight, true);

or:

 resized = Bitmap.createScaledBitmap(yourBitmap,(int)(yourBitmap.getWidth()*0.8), (int)(yourBitmap.getHeight()*0.8), true);