Programs & Examples On #Rowdetails

Adding a Button to a WPF DataGrid

Check this out:

XAML:

<DataGrid Name="DataGrid1">
    <DataGrid.Columns>
        <DataGridTemplateColumn>
            <DataGridTemplateColumn.CellTemplate>
                <DataTemplate>
                    <Button Click="ChangeText">Show/Hide</Button>
                </DataTemplate>
            </DataGridTemplateColumn.CellTemplate>
        </DataGridTemplateColumn>
    </DataGrid.Columns>
</DataGrid>

Method:

private void ChangeText(object sender, RoutedEventArgs e)
{
    DemoModel model = (sender as Button).DataContext as DemoModel;
    model.DynamicText = (new Random().Next(0, 100).ToString());
}

Class:

class DemoModel : INotifyPropertyChanged
{
    protected String _text;
    public String Text
    {
        get { return _text; }
        set { _text = value; RaisePropertyChanged("Text"); }
    }

    protected String _dynamicText;
    public String DynamicText
    {
        get { return _dynamicText; }
        set { _dynamicText = value; RaisePropertyChanged("DynamicText"); }
    }

    public event PropertyChangedEventHandler PropertyChanged;
    public void RaisePropertyChanged(String propertyName)
    {
        PropertyChangedEventHandler temp = PropertyChanged;
        if (temp != null)
        {
            temp(this, new PropertyChangedEventArgs(propertyName));
        }
    }
}

Initialization Code:

ObservableCollection<DemoModel> models = new ObservableCollection<DemoModel>();
models.Add(new DemoModel() { Text = "Some Text #1." });
models.Add(new DemoModel() { Text = "Some Text #2." });
models.Add(new DemoModel() { Text = "Some Text #3." });
models.Add(new DemoModel() { Text = "Some Text #4." });
models.Add(new DemoModel() { Text = "Some Text #5." });
DataGrid1.ItemsSource = models;

assign function return value to some variable using javascript

You could simply return a value from the function:

var response = 0;

function doSomething() {
    // some code
    return 10;
}
response = doSomething();

What is the largest Safe UDP Packet Size on the Internet

The theoretical limit (on Windows) for the maximum size of a UDP packet is 65507 bytes. This is documented here:

The correct maximum UDP message size is 65507, as determined by the following formula: 0xffff - (sizeof(IP Header) + sizeof(UDP Header)) = 65535-(20+8) = 65507

That being said, most protocols limit to a much smaller size - usually either 512 or occasionally 8192. You can often go higher than 548 safely if you are on a reliable network - but if you're broadcasting across the internet at large, the larger you go, the more likely you'll be to run into packet transmission problems and loss.

Getting coordinates of marker in Google Maps API

Also, you can display current position by "drag" listener and write it to visible or hidden field. You may also need to store zoom. Here's copy&paste from working tool:

            function map_init() {
            var lt=48.451778;
            var lg=31.646305;

            var myLatlng = new google.maps.LatLng(lt,lg);
            var mapOptions = {
                center: new google.maps.LatLng(lt,lg),
                zoom: 6,
                mapTypeId: google.maps.MapTypeId.ROADMAP
            };

            var map = new google.maps.Map(document.getElementById('map'),mapOptions);   
            var marker = new google.maps.Marker({
                position:myLatlng,
                map:map,
                draggable:true
            });

            google.maps.event.addListener(
                marker,
                'drag',
                function() {
                    document.getElementById('lat1').innerHTML = marker.position.lat().toFixed(6);
                    document.getElementById('lng1').innerHTML = marker.position.lng().toFixed(6);
                    document.getElementById('zoom').innerHTML = mapObject.getZoom();

                    // Dynamically show it somewhere if needed
                    $(".x").text(marker.position.lat().toFixed(6));
                    $(".y").text(marker.position.lng().toFixed(6));
                    $(".z").text(map.getZoom());

                }
            );                  
            }

Find row in datatable with specific id

Make a string criteria to search for, like this:

string searchExpression = "ID = 5"

Then use the .Select() method of the DataTable object, like this:

DataRow[] foundRows = YourDataTable.Select(searchExpression);

Now you can loop through the results, like this:

int numberOfCalls;
bool result;
foreach(DataRow dr in foundRows)
{
    // Get value of Calls here
    result = Int32.TryParse(dr["Calls"], out numberOfCalls);

    // Optionally, you can check the result of the attempted try parse here
    // and do something if you wish
    if(result)
    {
        // Try parse to 32-bit integer worked

    }
    else
    {
        // Try parse to 32-bit integer failed

    }
}

Docker: How to delete all local Docker images

Use this to delete everything:

docker system prune -a --volumes

Remove all unused containers, volumes, networks and images

WARNING! This will remove:
    - all stopped containers
    - all networks not used by at least one container
    - all volumes not used by at least one container
    - all images without at least one container associated to them
    - all build cache

https://docs.docker.com/engine/reference/commandline/system_prune/#extended-description

Hyper-V: Create shared folder between host and guest with internal network

Share Files, Folders or Drives Between Host and Hyper-V Virtual Machine

Prerequisites

  1. Ensure that Enhanced session mode settings are enabled on the Hyper-V host.

    Start Hyper-V Manager, and in the Actions section, select "Hyper-V Settings".

    hyper-v-settings

    Make sure that enhanced session mode is allowed in the Server section. Then, make sure that the enhanced session mode is available in the User section.

    use-enhanced-session-mode

  2. Enable Hyper-V Guest Services for your virtual machine

    Right-click on Virtual Machine > Settings. Select the Integration Services in the left-lower corner of the menu. Check Guest Service and click OK.

    enable-guest-services

Steps to share devices with Hyper-v virtual machine:

  1. Start a virtual machine and click Show Options in the pop-up windows.

    connect-to-vm

    Or click "Edit Session Settings..." in the Actions panel on the right

    edit-session-sessions

    It may only appear when you're (able to get) connected to it. If it doesn't appear try Starting and then Connecting to the VM while paying close attention to the panel in the Hyper-V Manager.

  2. View local resources. Then, select the "More..." menu.

    click-more

  3. From there, you can choose which devices to share. Removable drives are especially useful for file sharing.

    choose-the-devices-that-you-want-to-use

  4. Choose to "Save my settings for future connections to this virtual machine".

    save-my-settings-for-future-connections-to-this-vm

  5. Click Connect. Drive sharing is now complete, and you will see the shared drive in this PC > Network Locations section of Windows Explorer after using the enhanced session mode to sigh to the VM. You should now be able to copy files from a physical machine and paste them into a virtual machine, and vice versa.

    shared-drives-from-local-pc

Source (and for more info): Share Files, Folders or Drives Between Host and Hyper-V Virtual Machine

Laravel Eloquent Sum of relation's column

Auth::user()->products->sum('price');

The documentation is a little light for some of the Collection methods but all the query builder aggregates are seemingly available besides avg() that can be found at http://laravel.com/docs/queries#aggregates.

Maximum number of rows in an MS Access database engine table?

It's been some years since I last worked with Access but larger database files always used to have more problems and be more prone to corruption than smaller files.

Unless the database file is only being accessed by one person or stored on a robust network you may find this is a problem before the 2GB database size limit is reached.

How can I split a shell command over multiple lines when using an IF statement?

The line-continuation will fail if you have whitespace (spaces or tab characters[1]) after the backslash and before the newline. With no such whitespace, your example works fine for me:

$ cat test.sh
if ! fab --fabfile=.deploy/fabfile.py \
   --forward-agent \
   --disable-known-hosts deploy:$target; then
     echo failed
else
     echo succeeded
fi

$ alias fab=true; . ./test.sh
succeeded
$ alias fab=false; . ./test.sh
failed

Some detail promoted from the comments: the line-continuation backslash in the shell is not really a special case; it is simply an instance of the general rule that a backslash "quotes" the immediately-following character, preventing any special treatment it would normally be subject to. In this case, the next character is a newline, and the special treatment being prevented is terminating the command. Normally, a quoted character winds up included literally in the command; a backslashed newline is instead deleted entirely. But otherwise, the mechanism is the same. Most importantly, the backslash only quotes the immediately-following character; if that character is a space or tab, you just get a literal space or tab, and any subsequent newline remains unquoted.

[1] or carriage returns, for that matter, as Czechnology points out. Bash does not get along with Windows-formatted text files, not even in WSL. Or Cygwin, but at least their Bash port has added a set -o igncr option that you can set to make it carriage-return-tolerant.

Flask raises TemplateNotFound error even though template file exists

If you run your code from an installed package, make sure template files are present in directory <python root>/lib/site-packages/your-package/templates.


Some details:

In my case I was trying to run examples of project flask_simple_ui and jinja would always say

jinja2.exceptions.TemplateNotFound: form.html

The trick was that sample program would import installed package flask_simple_ui. And ninja being used from inside that package is using as root directory for lookup the package path, in my case ...python/lib/site-packages/flask_simple_ui, instead of os.getcwd() as one would expect.

To my bad luck, setup.py has a bug and doesn't copy any html files, including the missing form.html. Once I fixed setup.py, the problem with TemplateNotFound vanished.

I hope it helps someone.

When should you use constexpr capability in C++11?

From Stroustrup's speech at "Going Native 2012":

template<int M, int K, int S> struct Unit { // a unit in the MKS system
       enum { m=M, kg=K, s=S };
};

template<typename Unit> // a magnitude with a unit 
struct Value {
       double val;   // the magnitude 
       explicit Value(double d) : val(d) {} // construct a Value from a double 
};

using Speed = Value<Unit<1,0,-1>>;  // meters/second type
using Acceleration = Value<Unit<1,0,-2>>;  // meters/second/second type
using Second = Unit<0,0,1>;  // unit: sec
using Second2 = Unit<0,0,2>; // unit: second*second 

constexpr Value<Second> operator"" s(long double d)
   // a f-p literal suffixed by ‘s’
{
  return Value<Second> (d);  
}   

constexpr Value<Second2> operator"" s2(long double d)
  // a f-p literal  suffixed by ‘s2’ 
{
  return Value<Second2> (d); 
}

Speed sp1 = 100m/9.8s; // very fast for a human 
Speed sp2 = 100m/9.8s2; // error (m/s2 is acceleration)  
Speed sp3 = 100/9.8s; // error (speed is m/s and 100 has no unit) 
Acceleration acc = sp1/0.5s; // too fast for a human

Change jsp on button click

If you wanna do with a button click and not the other way. You can do it by adding location.href to your button. Here is how I'm using

<button class="btn btn-lg btn-primary" id="submit" onclick="location.href ='/dashboard'" >Go To Dashboard</button>

The button above uses bootstrap classes for styling. Without styling, the simplest code would be

<button onclick="location.href ='/dashboard'" >Go To Dashboard</button>

The /dashboard is my JSP page, If you are using extension too then used /dashboard.jsp

C++ Error 'nullptr was not declared in this scope' in Eclipse IDE

I add the ",-std=c++0x" after "-c -fmessage-length=0",under Project Properties -> C/C++ Build -> Settings -> GCC C++ Compiler -> Miscellaneous. Dont't forget to add the comma "," as the seperator.

java: How can I do dynamic casting of a variable from one type to another?

Just thought I would post something that I found quite useful and could be possible for someone who experiences similar needs.

The following method was a method I wrote for my JavaFX application to avoid having to cast and also avoid writing if object x instance of object b statements every time the controller was returned.

public <U> Optional<U> getController(Class<U> castKlazz){
    try {
        return Optional.of(fxmlLoader.<U>getController());
    }catch (Exception e){
        e.printStackTrace();
    }
    return Optional.empty();
}

The method declaration for obtaining the controller was

public <T> T getController()

By using type U passed into my method via the class object, it could be forwarded to the method get controller to tell it what type of object to return. An optional object is returned in case the wrong class is supplied and an exception occurs in which case an empty optional will be returned which we can check for.

This is what the final call to the method looked like (if present of the optional object returned takes a Consumer

getController(LoadController.class).ifPresent(controller->controller.onNotifyComplete());

How to write to files using utl_file in oracle

Here is a robust function for using UTL_File.putline that includes the necessary error handling. It also handles headers, footers and a few other exceptional cases.

PROCEDURE usp_OUTPUT_ToFileAscii(p_Path IN VARCHAR2, p_FileName IN VARCHAR2, p_Input IN refCursor, p_Header in VARCHAR2, p_Footer IN VARCHAR2, p_WriteMode VARCHAR2) IS

              vLine VARCHAR2(30000);
              vFile UTL_FILE.file_type; 
              vExists boolean;
              vLength number;
              vBlockSize number;
    BEGIN

        UTL_FILE.fgetattr(p_path, p_FileName, vExists, vLength, vBlockSize);

                 FETCH p_Input INTO vLine;
         IF p_input%ROWCOUNT > 0
         THEN
            IF vExists THEN
               vFile := UTL_FILE.FOPEN_NCHAR(p_Path, p_FileName, p_WriteMode);
            ELSE
               --even if the append flag is passed if the file doesn't exist open it with W.
                vFile := UTL_FILE.FOPEN(p_Path, p_FileName, 'W');
            END IF;
            --GET HANDLE TO FILE
            IF p_Header IS NOT NULL THEN 
              UTL_FILE.PUT_LINE(vFile, p_Header);
            END IF;
            UTL_FILE.PUT_LINE(vFile, vLine);
            DBMS_OUTPUT.PUT_LINE('Record count > 0');

             --LOOP THROUGH CURSOR VAR
             LOOP
                FETCH p_Input INTO vLine;

                EXIT WHEN p_Input%NOTFOUND;

                UTL_FILE.PUT_LINE(vFile, vLine);

             END LOOP;


             IF p_Footer IS NOT NULL THEN 
                UTL_FILE.PUT_LINE(vFile, p_Footer);
             END IF;

             CLOSE p_Input;
             UTL_FILE.FCLOSE(vFile);
        ELSE
          DBMS_OUTPUT.PUT_LINE('Record count = 0');

        END IF; 


    EXCEPTION
       WHEN UTL_FILE.INVALID_PATH THEN 
           DBMS_OUTPUT.PUT_LINE ('invalid_path'); 
           DBMS_OUTPUT.PUT_LINE(SQLERRM);
           RAISE;

       WHEN UTL_FILE.INVALID_MODE THEN 
           DBMS_OUTPUT.PUT_LINE ('invalid_mode'); 
           DBMS_OUTPUT.PUT_LINE(SQLERRM);
           RAISE;

       WHEN UTL_FILE.INVALID_FILEHANDLE THEN 
           DBMS_OUTPUT.PUT_LINE ('invalid_filehandle'); 
           DBMS_OUTPUT.PUT_LINE(SQLERRM);
           RAISE;

       WHEN UTL_FILE.INVALID_OPERATION THEN 
           DBMS_OUTPUT.PUT_LINE ('invalid_operation'); 
           DBMS_OUTPUT.PUT_LINE(SQLERRM);
           RAISE;

       WHEN UTL_FILE.READ_ERROR THEN  
           DBMS_OUTPUT.PUT_LINE ('read_error');
           DBMS_OUTPUT.PUT_LINE(SQLERRM);
           RAISE;

       WHEN UTL_FILE.WRITE_ERROR THEN 
          DBMS_OUTPUT.PUT_LINE ('write_error'); 
          DBMS_OUTPUT.PUT_LINE(SQLERRM);
           RAISE;

       WHEN UTL_FILE.INTERNAL_ERROR THEN 
          DBMS_OUTPUT.PUT_LINE ('internal_error'); 
          DBMS_OUTPUT.PUT_LINE(SQLERRM);
          RAISE;            
       WHEN OTHERS THEN
          DBMS_OUTPUT.PUT_LINE ('other write error'); 
          DBMS_OUTPUT.PUT_LINE(SQLERRM);
          RAISE;
    END;

Scope 'session' is not active for the current thread; IllegalStateException: No thread-bound request found

If anyone else stuck on same point, following solved my problem.

In web.xml

 <listener>
            <listener-class>
                    org.springframework.web.context.request.RequestContextListener 
            </listener-class>
  </listener>

In Session component

@Component
@Scope(value = "session",  proxyMode = ScopedProxyMode.TARGET_CLASS)

In pom.xml

    <dependency>
        <groupId>cglib</groupId>
        <artifactId>cglib</artifactId>
        <version>3.1</version>
    </dependency>

How to reshape data from long to wide format

Using your example dataframe, we could:

xtabs(value ~ name + numbers, data = dat1)

What's the difference between HTML 'hidden' and 'aria-hidden' attributes?

ARIA (Accessible Rich Internet Applications) defines a way to make Web content and Web applications more accessible to people with disabilities.

The hidden attribute is new in HTML5 and tells browsers not to display the element. The aria-hidden property tells screen-readers if they should ignore the element. Have a look at the w3 docs for more details:

https://www.w3.org/WAI/PF/aria/states_and_properties#aria-hidden

Using these standards can make it easier for disabled people to use the web.

How can I convert a Timestamp into either Date or DateTime object?

java.time

Modern answer: use java.time, the modern Java date and time API, for your date and time work. Back in 2011 it was right to use the Timestamp class, but since JDBC 4.2 it is no longer advised.

For your work we need a time zone and a couple of formatters. We may as well declare them static:

static ZoneId zone = ZoneId.of("America/Marigot");
static DateTimeFormatter dateFormatter = DateTimeFormatter.ofPattern("MM/dd/uuuu");
static DateTimeFormatter timeFormatter = DateTimeFormatter.ofPattern("HH:mm xx");

Now the code could be for example:

    while(resultSet.next()) {
        ZonedDateTime dtStart = resultSet.getObject("dtStart", OffsetDateTime.class)
                 .atZoneSameInstant(zone);

        // I would like to then have the date and time
        // converted into the formats mentioned...
        String dateFormatted = dtStart.format(dateFormatter);
        String timeFormatted = dtStart.format(timeFormatter);
        System.out.format("Date: %s; time: %s%n", dateFormatted, timeFormatted);
    }

Example output (using the time your question was asked):

Date: 09/20/2011; time: 18:13 -0400

In your database timestamp with time zone is recommended for timestamps. If this is what you’ve got, retrieve an OffsetDateTime as I am doing in the code. I am also converting the retrieved value to the user’s time zone before formatting date and time separately. As time zone I supplied America/Marigot as an example, please supply your own. You may also leave out the time zone conversion if you don’t want any, of course.

If the datatype in SQL is a mere timestamp without time zone, retrieve a LocalDateTime instead. For example:

        ZonedDateTime dtStart = resultSet.getObject("dtStart", LocalDateTime.class)
                 .atZone(zone);

No matter the details I trust you to do similarly for dtEnd.

I wasn’t sure what you meant by the xx in HH:MM xx. I just left it in the format pattern string, which yields the UTC offset in hours and minutes without colon.

Link: Oracle tutorial: Date Time explaining how to use java.time.

How to bind DataTable to Datagrid

I'd do it this way:

grid1.DataContext = dt.AsEnumerable().Where(x => x < 10).AsEnumerable().CopyToDataTable().AsDataView();

and do whatever query i want between the two AsEnumerable(). If you don't need space for query, you can just do directly this:

grid1.DataContext = dt.AsDataView();

Check if a given time lies between two times regardless of date

Modified @Surendra Jnawali' code. It fails

if current time is 23:40:00 i.e greater than start time and less than equals to 23:59:59.

All credit goes to the real owner

This is how it should be :This works perfect

public static boolean isTimeBetweenTwoTime(String argStartTime,
            String argEndTime, String argCurrentTime) throws ParseException {
        String reg = "^([0-1][0-9]|2[0-3]):([0-5][0-9]):([0-5][0-9])$";
        //
        if (argStartTime.matches(reg) && argEndTime.matches(reg)
                && argCurrentTime.matches(reg)) {
            boolean valid = false;
            // Start Time
            java.util.Date startTime = new SimpleDateFormat("HH:mm:ss")
                    .parse(argStartTime);
            Calendar startCalendar = Calendar.getInstance();
            startCalendar.setTime(startTime);

            // Current Time
            java.util.Date currentTime = new SimpleDateFormat("HH:mm:ss")
                    .parse(argCurrentTime);
            Calendar currentCalendar = Calendar.getInstance();
            currentCalendar.setTime(currentTime);

            // End Time
            java.util.Date endTime = new SimpleDateFormat("HH:mm:ss")
                    .parse(argEndTime);
            Calendar endCalendar = Calendar.getInstance();
            endCalendar.setTime(endTime);

            //
            if (currentTime.compareTo(endTime) < 0) {

                currentCalendar.add(Calendar.DATE, 1);
                currentTime = currentCalendar.getTime();

            }

            if (startTime.compareTo(endTime) < 0) {

                startCalendar.add(Calendar.DATE, 1);
                startTime = startCalendar.getTime();

            }
            //
            if (currentTime.before(startTime)) {

                System.out.println(" Time is Lesser ");

                valid = false;
            } else {

                if (currentTime.after(endTime)) {
                    endCalendar.add(Calendar.DATE, 1);
                    endTime = endCalendar.getTime();

                }

                System.out.println("Comparing , Start Time /n " + startTime);
                System.out.println("Comparing , End Time /n " + endTime);
                System.out
                        .println("Comparing , Current Time /n " + currentTime);

                if (currentTime.before(endTime)) {
                    System.out.println("RESULT, Time lies b/w");
                    valid = true;
                } else {
                    valid = false;
                    System.out.println("RESULT, Time does not lies b/w");
                }

            }
            return valid;

        } else {
            throw new IllegalArgumentException(
                    "Not a valid time, expecting HH:MM:SS format");
        }

    }

RESULT

Comparing , Start Time /n    Thu Jan 01 23:00:00 IST 1970
Comparing , End Time /n      Fri Jan 02 02:00:00 IST 1970
Comparing , Current Time /n  Fri Jan 02 01:50:00 IST 1970
RESULT, Time lies b/w

How to declare an ArrayList with values?

The Guava library contains convenience methods for creating lists and other collections which makes this much prettier than using the standard library classes.

Example:

ArrayList<String> list = newArrayList("a", "b", "c");

(This assumes import static com.google.common.collect.Lists.newArrayList;)

mysqldump exports only one table

Here I am going to export 3 tables from database named myDB in an sql file named table.sql

mysqldump -u root -p myDB table1 table2 table3 > table.sql

Get HTML code using JavaScript with a URL

First, you must know that you will never be able to get the source code of a page that is not on the same domain as your page in javascript. (See http://en.wikipedia.org/wiki/Same_origin_policy).

In PHP, this is how you do it:

file_get_contents($theUrl);

In javascript, there is three ways :

Firstly, by XMLHttpRequest : http://jsfiddle.net/635YY/1/

var url="../635YY",xmlhttp;//Remember, same domain
if("XMLHttpRequest" in window)xmlhttp=new XMLHttpRequest();
if("ActiveXObject" in window)xmlhttp=new ActiveXObject("Msxml2.XMLHTTP");
xmlhttp.open('GET',url,true);
xmlhttp.onreadystatechange=function()
{
    if(xmlhttp.readyState==4)alert(xmlhttp.responseText);
};
xmlhttp.send(null);

Secondly, by iFrames : http://jsfiddle.net/XYjuX/1/

var url="../XYjuX";//Remember, same domain
var iframe=document.createElement("iframe");
iframe.onload=function()
{
    alert(iframe.contentWindow.document.body.innerHTML);
}
iframe.src=url;
iframe.style.display="none";
document.body.appendChild(iframe);

Thirdly, by jQuery : [http://jsfiddle.net/edggD/2/

$.get('../edggD',function(data)//Remember, same domain
{
    alert(data);
});

]4

MaxLength Attribute not generating client-side validation attributes

I just used a snippet of jquery to solve this problem.

$("input[data-val-length-max]").each(function (index, element) {
   var length = parseInt($(this).attr("data-val-length-max"));
   $(this).prop("maxlength", length);
});

The selector finds all of the elements that have a data-val-length-max attribute set. This is the attribute that the StringLength validation attribute will set.

The each loop loops through these matches and will parse out the value for this attribute and assign it to the mxlength property that should have been set.

Just add this to you document ready function and you are good to go.

Calling a Function defined inside another function in Javascript

you can also just use return:

   function outer() { 
    function inner() {
        alert("hi");
    }
return inner();

}
outer();

"The underlying connection was closed: An unexpected error occurred on a send." With SSL Certificate

Go to your web.config/App.config to verify which .net runtime you are using

  <startup>
    <supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.6.1" />
  </startup>

Here is the solution:

  1. .NET 4.6 and above. You don’t need to do any additional work to support TLS 1.2, it’s supported by default.

  2. .NET 4.5. TLS 1.2 is supported, but it’s not a default protocol. You need to opt-in to use it. The following code will make TLS 1.2 default, make sure to execute it before making a connection to secured resource:

ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls12

  1. .NET 4.0. TLS 1.2 is not supported, but if you have .NET 4.5 (or above) installed on the system then you still can opt in for TLS 1.2 even if your application framework doesn’t support it. The only problem is that SecurityProtocolType in .NET 4.0 doesn’t have an entry for TLS1.2, so we’d have to use a numerical representation of this enum value:

ServicePointManager.SecurityProtocol = (SecurityProtocolType)3072;

  1. .NET 3.5 or below. TLS 1.2 is not supported (*) and there is no workaround. Upgrade your application to more recent version of the framework.

Select all child elements recursively in CSS

Use a white space to match all descendants of an element:

div.dropdown * {
    color: red;
}

x y matches every element y that is inside x, however deeply nested it may be - children, grandchildren and so on.

The asterisk * matches any element.

Official Specification: CSS 2.1: Chapter 5.5: Descendant Selectors

How to compare two date values with jQuery

Once you are able to parse those strings into a Date object comparing them is easy (Using the < operator). Parsing the dates will depend on the format. You may take a look at Datejs which might simplify this task.

How to Convert a Text File into a List in Python

This looks like a CSV file, so you could use the python csv module to read it. For example:

import csv

crimefile = open(fileName, 'r')
reader = csv.reader(crimefile)
allRows = [row for row in reader]

Using the csv module allows you to specify how things like quotes and newlines are handled. See the documentation I linked to above.

How to convert an array of strings to an array of floats in numpy?

If you have (or create) a single string, you can use np.fromstring:

import numpy as np
x = ["1.1", "2.2", "3.2"]
x = ','.join(x)
x = np.fromstring( x, dtype=np.float, sep=',' )

Note, x = ','.join(x) transforms the x array to string '1.1, 2.2, 3.2'. If you read a line from a txt file, each line will be already a string.

What is PECS (Producer Extends Consumer Super)?

In a nutshell, three easy rules to remember PECS:

  1. Use the <? extends T> wildcard if you need to retrieve object of type T from a collection.
  2. Use the <? super T> wildcard if you need to put objects of type T in a collection.
  3. If you need to satisfy both things, well, don’t use any wildcard. As simple as that.

Ruby - test for array

You probably want to use kind_of().

>> s = "something"
=> "something"
>> s.kind_of?(Array)
=> false
>> s = ["something", "else"]
=> ["something", "else"]
>> s.kind_of?(Array)
=> true

In Oracle SQL: How do you insert the current date + time into a table?

It only seems to because that is what it is printing out. But actually, you shouldn't write the logic this way. This is equivalent:

insert into errortable (dateupdated, table1id)
    values (sysdate, 1083);

It seems silly to convert the system date to a string just to convert it back to a date.

If you want to see the full date, then you can do:

select TO_CHAR(dateupdated, 'YYYY-MM-DD HH24:MI:SS'), table1id
from errortable;

Table 'mysql.user' doesn't exist:ERROR

You can run the following query to check for the existance of the user table.

SELECT * FROM information_schema.TABLES
WHERE TABLE_NAME LIKE '%user%'

See if you can find a row with the following values in

mysql   user    BASE TABLE  MyISAM  

If you cant find this table look at the following link to rebuild the database How to recover/recreate mysql's default 'mysql' database

Finding all the subsets of a set

Here is a solution in Scala:

def subsets[T](s : Set[T]) : Set[Set[T]] = 
  if (s.size == 0) Set(Set()) else { 
    val tailSubsets = subsets(s.tail); 
    tailSubsets ++ tailSubsets.map(_ + s.head) 
} 

How can I decrease the size of Ratingbar?

In RatingBar give attribute:

style="?android:attr/ratingBarStyleIndicator" 

Implementing INotifyPropertyChanged - does a better way exist?

As of .Net 4.5 there is finally an easy way to do this.

.Net 4.5 introduces a new Caller Information Attributes.

private void OnPropertyChanged<T>([CallerMemberName]string caller = null) {
     // make sure only to call this if the value actually changes

     var handler = PropertyChanged;
     if (handler != null) {
        handler(this, new PropertyChangedEventArgs(caller));
     }
}

It's probably a good idea to add a comparer to the function as well.

EqualityComparer<T>.Default.Equals

More examples here and here

Also see Caller Information (C# and Visual Basic)

How to update /etc/hosts file in Docker image during "docker build"

I'm using AWS Elasticbeanstalk + Docker + Supervisord.

Quick answer

Just add some code in Dockerfile.

CMD echo 123.123.123.123 this_is_my.host >> /etc/hosts; supervisord -n;

Preventing multiple clicks on button

I modified the solution by @Kalyani and so far it's been working beautifully!

$('selector').click(function(event) {
  if(!event.detail || event.detail == 1){ return true; }
  else { return false; }
});

I want to truncate a text or line with ellipsis using JavaScript

Something like:

var line = "foo bar lol";
line.substring(0, 5) + '...' // gives "foo b..."

Best practice for partial updates in a RESTful service

Check out http://www.odata.org/

It defines the MERGE method, so in your case it would be something like this:

MERGE /customer/123

<customer>
   <status>DISABLED</status>
</customer>

Only the status property is updated and the other values are preserved.

how to open Jupyter notebook in chrome on windows

I found an easier solution that may help beginners to coding.

go to

C:\Users\'-your user-'\AppData\Roaming\jupyter\runtime

and find a file named

nbserver-6176-open.html

then

Right-click > open with > Choose default program...

Here, what ever you choose would be saved on your Windows to open all HTML files; therefore when you run Jupyter notebook, it would open in the program you want.

What is the difference between persist() and merge() in JPA and Hibernate?

JPA specification contains a very precise description of semantics of these operations, better than in javadoc:

The semantics of the persist operation, applied to an entity X are as follows:

  • If X is a new entity, it becomes managed. The entity X will be entered into the database at or before transaction commit or as a result of the flush operation.

  • If X is a preexisting managed entity, it is ignored by the persist operation. However, the persist operation is cascaded to entities referenced by X, if the relationships from X to these other entities are annotated with the cascade=PERSIST or cascade=ALL annotation element value or specified with the equivalent XML descriptor element.

  • If X is a removed entity, it becomes managed.

  • If X is a detached object, the EntityExistsException may be thrown when the persist operation is invoked, or the EntityExistsException or another PersistenceException may be thrown at flush or commit time.

  • For all entities Y referenced by a relationship from X, if the relationship to Y has been annotated with the cascade element value cascade=PERSIST or cascade=ALL, the persist operation is applied to Y.


The semantics of the merge operation applied to an entity X are as follows:

  • If X is a detached entity, the state of X is copied onto a pre-existing managed entity instance X' of the same identity or a new managed copy X' of X is created.

  • If X is a new entity instance, a new managed entity instance X' is created and the state of X is copied into the new managed entity instance X'.

  • If X is a removed entity instance, an IllegalArgumentException will be thrown by the merge operation (or the transaction commit will fail).

  • If X is a managed entity, it is ignored by the merge operation, however, the merge operation is cascaded to entities referenced by relationships from X if these relationships have been annotated with the cascade element value cascade=MERGE or cascade=ALL annotation.

  • For all entities Y referenced by relationships from X having the cascade element value cascade=MERGE or cascade=ALL, Y is merged recursively as Y'. For all such Y referenced by X, X' is set to reference Y'. (Note that if X is managed then X is the same object as X'.)

  • If X is an entity merged to X', with a reference to another entity Y, where cascade=MERGE or cascade=ALL is not specified, then navigation of the same association from X' yields a reference to a managed object Y' with the same persistent identity as Y.

SQL injection that gets around mysql_real_escape_string()

TL;DR

mysql_real_escape_string() will provide no protection whatsoever (and could furthermore munge your data) if:

  • MySQL's NO_BACKSLASH_ESCAPES SQL mode is enabled (which it might be, unless you explicitly select another SQL mode every time you connect); and

  • your SQL string literals are quoted using double-quote " characters.

This was filed as bug #72458 and has been fixed in MySQL v5.7.6 (see the section headed "The Saving Grace", below).

This is another, (perhaps less?) obscure EDGE CASE!!!

In homage to @ircmaxell's excellent answer (really, this is supposed to be flattery and not plagiarism!), I will adopt his format:

The Attack

Starting off with a demonstration...

mysql_query('SET SQL_MODE="NO_BACKSLASH_ESCAPES"'); // could already be set
$var = mysql_real_escape_string('" OR 1=1 -- ');
mysql_query('SELECT * FROM test WHERE name = "'.$var.'" LIMIT 1');

This will return all records from the test table. A dissection:

  1. Selecting an SQL Mode

    mysql_query('SET SQL_MODE="NO_BACKSLASH_ESCAPES"');
    

    As documented under String Literals:

    There are several ways to include quote characters within a string:

    • A “'” inside a string quoted with “'” may be written as “''”.

    • A “"” inside a string quoted with “"” may be written as “""”.

    • Precede the quote character by an escape character (“\”).

    • A “'” inside a string quoted with “"” needs no special treatment and need not be doubled or escaped. In the same way, “"” inside a string quoted with “'” needs no special treatment.

    If the server's SQL mode includes NO_BACKSLASH_ESCAPES, then the third of these options—which is the usual approach adopted by mysql_real_escape_string()—is not available: one of the first two options must be used instead. Note that the effect of the fourth bullet is that one must necessarily know the character that will be used to quote the literal in order to avoid munging one's data.

  2. The Payload

    " OR 1=1 -- 
    

    The payload initiates this injection quite literally with the " character. No particular encoding. No special characters. No weird bytes.

  3. mysql_real_escape_string()

    $var = mysql_real_escape_string('" OR 1=1 -- ');
    

    Fortunately, mysql_real_escape_string() does check the SQL mode and adjust its behaviour accordingly. See libmysql.c:

    ulong STDCALL
    mysql_real_escape_string(MYSQL *mysql, char *to,const char *from,
                 ulong length)
    {
      if (mysql->server_status & SERVER_STATUS_NO_BACKSLASH_ESCAPES)
        return escape_quotes_for_mysql(mysql->charset, to, 0, from, length);
      return escape_string_for_mysql(mysql->charset, to, 0, from, length);
    }
    

    Thus a different underlying function, escape_quotes_for_mysql(), is invoked if the NO_BACKSLASH_ESCAPES SQL mode is in use. As mentioned above, such a function needs to know which character will be used to quote the literal in order to repeat it without causing the other quotation character from being repeated literally.

    However, this function arbitrarily assumes that the string will be quoted using the single-quote ' character. See charset.c:

    /*
      Escape apostrophes by doubling them up
    
    // [ deletia 839-845 ]
    
      DESCRIPTION
        This escapes the contents of a string by doubling up any apostrophes that
        it contains. This is used when the NO_BACKSLASH_ESCAPES SQL_MODE is in
        effect on the server.
    
    // [ deletia 852-858 ]
    */
    
    size_t escape_quotes_for_mysql(CHARSET_INFO *charset_info,
                                   char *to, size_t to_length,
                                   const char *from, size_t length)
    {
    // [ deletia 865-892 ]
    
        if (*from == '\'')
        {
          if (to + 2 > to_end)
          {
            overflow= TRUE;
            break;
          }
          *to++= '\'';
          *to++= '\'';
        }
    

    So, it leaves double-quote " characters untouched (and doubles all single-quote ' characters) irrespective of the actual character that is used to quote the literal! In our case $var remains exactly the same as the argument that was provided to mysql_real_escape_string()—it's as though no escaping has taken place at all.

  4. The Query

    mysql_query('SELECT * FROM test WHERE name = "'.$var.'" LIMIT 1');
    

    Something of a formality, the rendered query is:

    SELECT * FROM test WHERE name = "" OR 1=1 -- " LIMIT 1
    

As my learned friend put it: congratulations, you just successfully attacked a program using mysql_real_escape_string()...

The Bad

mysql_set_charset() cannot help, as this has nothing to do with character sets; nor can mysqli::real_escape_string(), since that's just a different wrapper around this same function.

The problem, if not already obvious, is that the call to mysql_real_escape_string() cannot know with which character the literal will be quoted, as that's left to the developer to decide at a later time. So, in NO_BACKSLASH_ESCAPES mode, there is literally no way that this function can safely escape every input for use with arbitrary quoting (at least, not without doubling characters that do not require doubling and thus munging your data).

The Ugly

It gets worse. NO_BACKSLASH_ESCAPES may not be all that uncommon in the wild owing to the necessity of its use for compatibility with standard SQL (e.g. see section 5.3 of the SQL-92 specification, namely the <quote symbol> ::= <quote><quote> grammar production and lack of any special meaning given to backslash). Furthermore, its use was explicitly recommended as a workaround to the (long since fixed) bug that ircmaxell's post describes. Who knows, some DBAs might even configure it to be on by default as means of discouraging use of incorrect escaping methods like addslashes().

Also, the SQL mode of a new connection is set by the server according to its configuration (which a SUPER user can change at any time); thus, to be certain of the server's behaviour, you must always explicitly specify your desired mode after connecting.

The Saving Grace

So long as you always explicitly set the SQL mode not to include NO_BACKSLASH_ESCAPES, or quote MySQL string literals using the single-quote character, this bug cannot rear its ugly head: respectively escape_quotes_for_mysql() will not be used, or its assumption about which quote characters require repeating will be correct.

For this reason, I recommend that anyone using NO_BACKSLASH_ESCAPES also enables ANSI_QUOTES mode, as it will force habitual use of single-quoted string literals. Note that this does not prevent SQL injection in the event that double-quoted literals happen to be used—it merely reduces the likelihood of that happening (because normal, non-malicious queries would fail).

In PDO, both its equivalent function PDO::quote() and its prepared statement emulator call upon mysql_handle_quoter()—which does exactly this: it ensures that the escaped literal is quoted in single-quotes, so you can be certain that PDO is always immune from this bug.

As of MySQL v5.7.6, this bug has been fixed. See change log:

Functionality Added or Changed

Safe Examples

Taken together with the bug explained by ircmaxell, the following examples are entirely safe (assuming that one is either using MySQL later than 4.1.20, 5.0.22, 5.1.11; or that one is not using a GBK/Big5 connection encoding):

mysql_set_charset($charset);
mysql_query("SET SQL_MODE=''");
$var = mysql_real_escape_string('" OR 1=1 /*');
mysql_query('SELECT * FROM test WHERE name = "'.$var.'" LIMIT 1');

...because we've explicitly selected an SQL mode that doesn't include NO_BACKSLASH_ESCAPES.

mysql_set_charset($charset);
$var = mysql_real_escape_string("' OR 1=1 /*");
mysql_query("SELECT * FROM test WHERE name = '$var' LIMIT 1");

...because we're quoting our string literal with single-quotes.

$stmt = $pdo->prepare('SELECT * FROM test WHERE name = ? LIMIT 1');
$stmt->execute(["' OR 1=1 /*"]);

...because PDO prepared statements are immune from this vulnerability (and ircmaxell's too, provided either that you're using PHP=5.3.6 and the character set has been correctly set in the DSN; or that prepared statement emulation has been disabled).

$var  = $pdo->quote("' OR 1=1 /*");
$stmt = $pdo->query("SELECT * FROM test WHERE name = $var LIMIT 1");

...because PDO's quote() function not only escapes the literal, but also quotes it (in single-quote ' characters); note that to avoid ircmaxell's bug in this case, you must be using PHP=5.3.6 and have correctly set the character set in the DSN.

$stmt = $mysqli->prepare('SELECT * FROM test WHERE name = ? LIMIT 1');
$param = "' OR 1=1 /*";
$stmt->bind_param('s', $param);
$stmt->execute();

...because MySQLi prepared statements are safe.

Wrapping Up

Thus, if you:

  • use native prepared statements

OR

  • use MySQL v5.7.6 or later

OR

  • in addition to employing one of the solutions in ircmaxell's summary, use at least one of:

    • PDO;
    • single-quoted string literals; or
    • an explicitly set SQL mode that does not include NO_BACKSLASH_ESCAPES

...then you should be completely safe (vulnerabilities outside the scope of string escaping aside).

How to do perspective fixing?

The simple solution is to just remap coordinates from the original to the final image, copying pixels from one coordinate space to the other, rounding off as necessary -- which may result in some pixels being copied several times adjacent to each other, and other pixels being skipped, depending on whether you're stretching or shrinking (or both) in either dimension. Make sure your copying iterates through the destination space, so all pixels are covered there even if they're painted more than once, rather than thru the source which may skip pixels in the output.

The better solution involves calculating the corresponding source coordinate without rounding, and then using its fractional position between pixels to compute an appropriate average of the (typically) four pixels surrounding that location. This is essentially a filtering operation, so you lose some resolution -- but the result looks a LOT better to the human eye; it does a much better job of retaining small details and avoids creating straight-line artifacts which humans find objectionable.

Note that the same basic approach can be used to remap flat images onto any other shape, including 3D surface mapping.

Java: Get first item from a collection

Guava provides an onlyElement Collector, but only use it if you expect the collection to have exactly one element.

Collection<String> stringCollection = ...;
String string = collection.stream().collect(MoreCollectors.onlyElement())

If you are unsure of how many elements there are, use findFirst.

Optional<String> optionalString = collection.stream().findFirst();

Set font-weight using Bootstrap classes

I found this on the Bootstrap website, but it really isn't a Bootstrap class, it's just HTML.

<strong>rendered as bold text</strong>

Sql Server equivalent of a COUNTIF aggregate function

You could use a SUM (not COUNT!) combined with a CASE statement, like this:

SELECT SUM(CASE WHEN myColumn=1 THEN 1 ELSE 0 END)
FROM AD_CurrentView

Note: in my own test NULLs were not an issue, though this can be environment dependent. You could handle nulls such as:

SELECT SUM(CASE WHEN ISNULL(myColumn,0)=1 THEN 1 ELSE 0 END)
FROM AD_CurrentView

.NET HttpClient. How to POST string value?

You could do something like this

HttpWebRequest req = (HttpWebRequest)WebRequest.Create("http://localhost:6740/api/Membership/exist");

req.Method = "POST";
req.ContentType = "application/x-www-form-urlencoded";         
req.ContentLength = 6;

StreamWriter streamOut = new StreamWriter(req.GetRequestStream(), System.Text.Encoding.ASCII);
streamOut.Write(strRequest);
streamOut.Close();
StreamReader streamIn = new StreamReader(req.GetResponse().GetResponseStream());
string strResponse = streamIn.ReadToEnd();
streamIn.Close();

And then strReponse should contain the values returned by your webservice

Why are static variables considered evil?

All the answers above show why statics are bad. The reason they are evil is because it gives the false impression that you are writing object oriented code, when in fact you are not. That is just plain evil.

Is it possible to create static classes in PHP (like in C#)?

I generally prefer to write regular non static classes and use a factory class to instantiate single ( sudo static ) instances of the object.

This way constructor and destructor work as per normal, and I can create additional non static instances if I wish ( for example a second DB connection )

I use this all the time and is especially useful for creating custom DB store session handlers, as when the page terminates the destructor will push the session to the database.

Another advantage is you can ignore the order you call things as everything will be setup on demand.

class Factory {
    static function &getDB ($construct_params = null)
    {
        static $instance;
        if( ! is_object($instance) )
        {
            include_once("clsDB.php");
            $instance = new clsDB($construct_params);   // constructor will be called
        }
        return $instance;
    }
}

The DB class...

class clsDB {

    $regular_public_variables = "whatever";

    function __construct($construct_params) {...}
    function __destruct() {...}

    function getvar() { return $this->regular_public_variables; }
}

Anywhere you want to use it just call...

$static_instance = &Factory::getDB($somekickoff);

Then just treat all methods as non static ( because they are )

echo $static_instance->getvar();

How to determine day of week by passing specific date?

private String getDay(Date date){

    SimpleDateFormat simpleDateFormat = new SimpleDateFormat("EEEE");
    //System.out.println("DAY "+simpleDateFormat.format(date).toUpperCase());                       
    return simpleDateFormat.format(date).toUpperCase();
}

private String getDay(String dateStr){
    //dateStr must be in DD-MM-YYYY Formate
    Date date = null;
    String day=null;

    try {
        date = new SimpleDateFormat("DD-MM-YYYY").parse(dateStr);

        SimpleDateFormat simpleDateFormat = new SimpleDateFormat("EEEE");
        //System.out.println("DAY "+simpleDateFormat.format(date).toUpperCase());
        day = simpleDateFormat.format(date).toUpperCase();


    } catch (ParseException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }


    return day;
}

Counting in a FOR loop using Windows Batch script

It's not working because the entire for loop (from the for to the final closing parenthesis, including the commands between those) is being evaluated when it's encountered, before it begins executing.

In other words, %count% is replaced with its value 1 before running the loop.

What you need is something like:

setlocal enableextensions enabledelayedexpansion
set /a count = 1
for /f "tokens=*" %%a in (config.properties) do (
  set /a count += 1
  echo !count!
)
endlocal

Delayed expansion using ! instead of % will give you the expected behaviour. See also here.


Also keep in mind that setlocal/endlocal actually limit scope of things changed inside so that they don't leak out. If you want to use count after the endlocal, you have to use a "trick" made possible by the very problem you're having:

endlocal && set count=%count%

Let's say count has become 7 within the inner scope. Because the entire command is interpreted before execution, it effectively becomes:

endlocal && set count=7

Then, when it's executed, the inner scope is closed off, returning count to it's original value. But, since the setting of count to seven happens in the outer scope, it's effectively leaking the information you need.

You can string together multiple sub-commands to leak as much information as you need:

endlocal && set count=%count% && set something_else=%something_else%

Why would a JavaScript variable start with a dollar sign?

${varname} is just a naming convention jQuery developers use to distinguish variables that are holding jQuery elements.

Plain {varname} is used to store general stuffs like texts and strings. ${varname} holds elements returned from jQuery.

You can use plain {varname} to store jQuery elements as well, but as I said in the beginning this distinguishes it from the plain variables and makes it much easier to understand (imagine confusing it for a plain variable and searching all over to understand what it holds).

For example :

var $blah = $(this).parents('.blahblah');

Here, blah is storing a returned jQuery element.

So, when someone else see the $blah in the code, they'll understand it's not just a string or a number, it's a jQuery element.

What do Push and Pop mean for Stacks?

The rifle clip analogy posted by Oren A is pretty good, but I'll try another one and try to anticipate what the instructor was trying to get across.

A stack, as it's name suggests is an arrangement of "things" that has:

  • A top
  • A bottom
  • An ordering in between the top and bottom (e.g. second from the top, 3rd from the bottom).

(think of it as a literal stack of books on your desk and you can only take something from the top)

Pushing something on the stack means "placing it on top". Popping something from the stack means "taking the top 'thing'" off the stack.

A simple usage is for reversing the order of words. Say I want to reverse the word: "popcorn". I push each letter from left to right (all 7 letters), and then pop 7 letters and they'll end up in reverse order. It looks like this was what he was doing with those expressions.

push(p) push(o) push(p) push(c) push(o) push(r) push(n)

after pushing the entire word, the stack looks like:

   |  n   |  <- top
   |  r   |
   |  o   |
   |  c   |
   |  p   |
   |  o   |
   |  p   |  <- bottom (first "thing" pushed on an empty stack)
    ======

when I pop() seven times, I get the letters in this order:

n,r,o,c,p,o,p

conversion of infix/postfix/prefix is a pathological example in computer science when teaching stacks:

Infix to Postfix conversion.

Post fix conversion to an infix expression is pretty straight forward:

(scan expression from left to right)

  1. For every number (operand) push it on the stack.
  2. Every time you encounter an operator (+,-,/,*) pop twice from the stack and place the operator between them. Push that on the stack:

So if we have 53+2* we can convert that to infix in the following steps:

  1. Push 5.
  2. Push 3.
  3. Encountered +: pop 3, pop 5, push 5+3 on stack (be consistent with ordering of 5 and 3)
  4. Push 2.
  5. Encountered *: pop 2, pop (5+3), push (2 * (5+3)).

*When you reach the end of the expression, if it was formed correctly you stack should only contain one item.

By introducing 'x' and 'o' he may have been using them as temporary holders for the left and right operands of an infix expression: x + o, x - o, etc. (or order of x,o reversed).

There's a nice write up on wikipedia as well. I've left my answer as a wiki incase I've botched up any ordering of expressions.

Create a dropdown component

This is the code to create dropdown in Angular 7, 8, 9

.html file code

<div>
<label>Summary: </label>
<select (change)="SelectItem($event.target.value)" class="select">
  <option value="0">--All--</option>
  <option *ngFor="let item of items" value="{{item.Id.Value}}">
    {{item.Name}}
  </option>
</select>
</div>

.ts file code

SelectItem(filterVal: any)
{
    var id=filterVal;
    //code
}

items is an array which should be initialized in .ts file.

What is the difference between VFAT and FAT32 file systems?

FAT32 along with FAT16 and FAT12 are File System Types, but vfat along with umsdos and msdos are drivers, used to mount the FAT file systems in Linux. The choosing of the driver determines how some of the features are applied to the file system, for example, systems mounted with msdos driver don't have long filenames (they are 8.3 format). vfat is the most common driver for mounting FAT32 file systems nowadays.

Source: this wikipedia article

Output of commands like df and lsblk indeed show vfat as the File System Type. But sudo file -sL /dev/<partition> shows FAT (32 bit) if a File System is FAT32.

You can confirm vfat is a module and not a File System Type by running modinfo vfat.

ORA-01950: no privileges on tablespace 'USERS'

You cannot insert data because you have a quota of 0 on the tablespace. To fix this, run

ALTER USER <user> quota unlimited on <tablespace name>;

or

ALTER USER <user> quota 100M on <tablespace name>;

as a DBA user (depending on how much space you need / want to grant).

Get button click inside UITableViewCell

If you want to pass parameter value from cell to UIViewController using closure then

//Your Cell Class
class TheCell: UITableViewCell {

    var callBackBlockWithParam: ((String) -> ()) = {_ in }

//Your Action on button
    @IBAction func didTap(_ sender: Any) {
        callBackBlockWithParam("Your Required Parameter like you can send button as sender or anything just change parameter type. Here I am passing string")
    }
}

//Your Controller
extension TheController: UITableViewDataSource {
    func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
            let cell = tableView.dequeueReusableCell(withIdentifier: TheCell.identifier, for: indexPath) as! TheCell {
            cell.callBackBlockWithParam = { (passedParamter) in 

             //you will get string value from cell class
                print(passedParamter)     
      }
            return cell
    }
}

How to check if element exists using a lambda expression?

While the accepted answer is correct, I'll add a more elegant version (in my opinion):

boolean idExists = tabPane.getTabs().stream()
    .map(Tab::getId)
    .anyMatch(idToCheck::equals);

Don't neglect using Stream#map() which allows to flatten the data structure before applying the Predicate.

Can't Load URL: The domain of this URL isn't included in the app's domains

Like the other answer says, in the left hand side select Products and add product. Then select Facbook Login.

I then added http://localhost:3000/ to the field 'Valid OAuth redirect URIs', and then everything worked.

Detect when an image fails to load in Javascript

Here's a function I wrote for another answer: Javascript Image Url Verify. I don't know if it's exactly what you need, but it uses the various techniques that you would use which include handlers for onload, onerror, onabort and a general timeout.

Because image loading is asynchronous, you call this function with your image and then it calls your callback sometime later with the result.

Run a command over SSH with JSch

using ssh from java should not be as hard as jsch makes it. you might be better off with sshj.

Sending email from Azure

A nice way to achieve this "if you have an office 365 account" is to use Office 365 outlook connector integrated with Azure Logic App,

Hope this helps someone!

How to install Flask on Windows?

On Windows, installation of easy_install is a little bit trickier, but still quite easy. The easiest way to do it is to download the distribute_setup.py file and run it. The easiest way to run the file is to open your downloads folder and double-click on the file.

Next, add the easy_install command and other Python scripts to the command search path, by adding your Python installation’s Scripts folder to the PATH environment variable. To do that, right-click on the “Computer” icon on the Desktop or in the Start menu, and choose “Properties”. Then click on “Advanced System settings” (in Windows XP, click on the “Advanced” tab instead). Then click on the “Environment variables” button. Finally, double-click on the “Path” variable in the “System variables” section, and add the path of your Python interpreter’s Scripts folder. Be sure to delimit it from existing values with a semicolon. Assuming you are using Python 2.7 on the default path, add the following value:

;C:\Python27\Scripts And you are done! To check that it worked, open the Command Prompt and execute easy_install. If you have User Account Control enabled on Windows Vista or Windows 7, it should prompt you for administrator privileges.

Now that you have easy_install, you can use it to install pip:

easy_install pip

using mailto to send email with an attachment

If you are using c# on the desktop, you can use SimpleMapi. That way it will be sent using the default mail client, and the user has the option of reviewing the message before sending, just like mailto:.

To use it you add the Simple-MAPI.NET package (it's 13Kb), and run:

var mapi = new SimpleMapi();
mapi.AddRecipient(null, address, false);
mapi.Attach(path);
//mapi.Logon(ParentForm.Handle);    //not really necessary
mapi.Send(subject, body, true);

Failing to run jar file from command line: “no main manifest attribute”

You need to include "Main class" attribute in Manisfest.mf file in Jar

For example: Main-Class: MyClassName

Second thing, To add Manifest file in Your jar, You can manually create file in your workspace folder, and refresh in Eclipse Project explorer.

While exporting, Eclipse will create a Jar which will include your manifest.

Cheers !!

How to get CRON to call in the correct PATHs

Make your variables work for you, this will allow access t

Define your PATH in /etc/profile.d/*.sh

System-wide environment variables

Files with the .sh extension in the /etc/profile.d directory get executed whenever a bash login shell is entered (e.g. when logging in from the console or over ssh), as well as by the DisplayManager when the desktop session loads.

You can for instance create the file /etc/profile.d/myenvvars.sh and set variables like this:

export JAVA_HOME=/usr/lib/jvm/jdk1.7.0
export PATH=$PATH:$JAVA_HOME/bin

Execute crontab with login option!

CRONTAB run script or command with Environment Variables

0 9 * * * cd /var/www/vhosts/foo/crons/; bash -l -c 'php -f ./download.php'
0 9 * * * cd /var/www/vhosts/foo/crons/; bash -l -c download.sh

How do I find the current directory of a batch file, and then use it for the path?

Try in yourbatch

set "batchisin=%~dp0"

which should set the variable to your batch's location.

Adding two numbers concatenates them instead of calculating the sum

Use parseFloat it will convert string to number including decimal values.

 function myFunction() {
      var y = document.getElementById("txt1").value;
      var z = document.getElementById("txt2").value;
      var x = parseFloat(y) + parseFloat(z);
      document.getElementById("demo").innerHTML = x;
    }


<p>
  Click the button to calculate x.
  <button onclick="myFunction()">Try it</button>
</p>
<p>
  Enter first number:
  <input type="text" id="txt1" name="text1" value="1">
  Enter second number:
  <input type="text" id="txt2" name="text2" value="2">
</p>
<p id="demo"></p>

Set background image in CSS using jquery

try this

 $(this).parent().css("backgroundImage", "url('../images/r-srchbg_white.png') no-repeat");

Hide/Show Action Bar Option Menu Item for different fragments

Try this...

You don't need to override onCreateOptionsMenu() in your Fragment class again. Menu items visibility can be changed by overriding onPrepareOptionsMenu() method available in Fragment class.

 @Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setHasOptionsMenu(true);
}
@Override
public void onPrepareOptionsMenu(Menu menu) {
    menu.findItem(R.id.action_search).setVisible(false);
    super.onPrepareOptionsMenu(menu);
}

The first day of the current month in php using date_modify as DateTime object

I use a crazy way to do this is using this command

$firstDay=date('Y-m-d',strtotime("first day of this month"));
$lastDay=date('Y-m-d',strtotime("last day of this month"));

Thats all

jQuery UI " $("#datepicker").datepicker is not a function"

In my case, it was solved by changing the import order of the following scripts: Before (Not work):

After (Working):

Use of 'const' for function parameters

Ah, a tough one. On one side, a declaration is a contract and it really does not make sense to pass a const argument by value. On the other hand, if you look at the function implementation, you give the compiler more chances to optimize if you declare an argument constant.

How do I concatenate strings with variables in PowerShell?

You could use the PowerShell equivalent of String.Format - it's usually the easiest way to build up a string. Place {0}, {1}, etc. where you want the variables in the string, put a -f immediately after the string and then the list of variables separated by commas.

Get-ChildItem c:\code|%{'{0}\{1}\{2}.dll' -f $_.fullname,$buildconfig,$_.name}

(I've also taken the dash out of the $buildconfig variable name as I have seen that causes issues before too.)

How to change UIPickerView height

As mentioned above UIPickerView is now resizable. I just want to add though that if you want to change the pickerView's height in a tableView Cell, I didn't have any success with setting the height anchor to a constant. However, using lessThanOrEqualToConstant seems to work.

 class PickerViewCell: UITableViewCell {

    let pickerView = UIPickerView()

    func setup() {

        // call this from however you initialize your cell

        self.contentView.addSubview(self.pickerView)
        self.pickerView.translatesAutoresizingMaskIntoConstraints = false

        let constraints: [NSLayoutConstraint] = [
            // pin the pickerView to the contentView's layoutMarginsGuide

            self.pickerView.leadingAnchor.constraint(equalTo: self.contentView.layoutMarginsGuide.leadingAnchor),
            self.pickerView.topAnchor.constraint(equalTo: self.contentView.layoutMarginsGuide.topAnchor),
            self.pickerView.trailingAnchor.constraint(equalTo: self.contentView.layoutMarginsGuide.trailingAnchor),
            self.pickerView.bottomAnchor.constraint(equalTo: self.contentView.layoutMarginsGuide.bottomAnchor),

            // set the height using lessThanOrEqualToConstant
            self.pickerView.heightAnchor.constraint(lessThanOrEqualToConstant: 100)
        ]

        NSLayoutConstraint.activate(constraints)
     }

 }

how to add key value pair in the JSON object already declared

Could you do the following:

obj = {
    "1":"aa",
    "2":"bb"
};


var newNum = "3";
var newVal = "cc";


obj[newNum] = newVal;



alert(obj["3"]); // this would alert 'cc'

How to show a confirm message before delete?

var txt;
var r = confirm("Press a button!");
if (r == true) {
   txt = "You pressed OK!";
} else {
   txt = "You pressed Cancel!";
}

_x000D_
_x000D_
var txt;_x000D_
var r = confirm("Press a button!");_x000D_
if (r == true) {_x000D_
    txt = "You pressed OK!";_x000D_
} else {_x000D_
    txt = "You pressed Cancel!";_x000D_
}
_x000D_
_x000D_
_x000D_

Python TypeError: not enough arguments for format string

I got the same error when using % as a percent character in my format string. The solution to this is to double up the %%.

Comparing boxed Long values 127 and 128

Java caches the primitive values from -128 to 127. When we compare two Long objects java internally type cast it to primitive value and compare it. But above 127 the Long object will not get type caste. Java caches the output by .valueOf() method.

This caching works for Byte, Short, Long from -128 to 127. For Integer caching works From -128 to java.lang.Integer.IntegerCache.high or 127, whichever is bigger.(We can set top level value upto which Integer values should get cached by using java.lang.Integer.IntegerCache.high).

 For example:
    If we set java.lang.Integer.IntegerCache.high=500;
    then values from -128 to 500 will get cached and 

    Integer a=498;
    Integer b=499;
    System.out.println(a==b)

    Output will be "true".

Float and Double objects never gets cached.

Character will get cache from 0 to 127

You are comparing two objects. so == operator will check equality of object references. There are following ways to do it.

1) type cast both objects into primitive values and compare

    (long)val3 == (long)val4

2) read value of object and compare

    val3.longValue() == val4.longValue()

3) Use equals() method on object comparison.

    val3.equals(val4);  

Regular Expressions- Match Anything

The 2018 specification provides the s flag (alias: dotAll), so that . will match any character, including linebreaks:

_x000D_
_x000D_
const regExAll = /.*/s; //notice the 's'

let str = `
Everything
    in  this
            string
                    will
                        be
    matched. Including whitespace (even Linebreaks).
`;

console.log(`Match:`, regExAll.test(str)); //true
console.log(`Index Location:`, str.search(regExAll));

let newStr = str.replace(regExAll,"");
console.log(`Replaced with:`,newStr); //Index: 0
_x000D_
_x000D_
_x000D_

Typescript: TS7006: Parameter 'xxx' implicitly has an 'any' type

if you get an error as Parameter 'element' implicitly has an 'any' type.Vetur(7006) in vueJs

with the error:

 exportColumns.forEach(element=> {
      if (element.command !== undefined) {
        let d = element.command.findIndex(x => x.name === "destroy");

you can fixed it by defining thoes variables as any as follow.

corrected code:

exportColumns.forEach((element: any) => {
      if (element.command !== undefined) {
        let d = element.command.findIndex((x: any) => x.name === "destroy");

Send a base64 image in HTML email

Support, unfortunately, is brutal at best. Here's a post on the topic:

https://www.campaignmonitor.com/blog/email-marketing/2013/02/embedded-images-in-html-email/

And the post content: enter image description here

How to use multiple LEFT JOINs in SQL?

Yes, but the syntax is different than what you have

SELECT
    <fields>
FROM
    <table1>
    LEFT JOIN <table2>
        ON <criteria for join>
        AND <other criteria for join>
    LEFT JOIN <table3> 
        ON <criteria for join>
        AND <other criteria for join>

LaTeX: remove blank page after a \part or \chapter

I believe that in the book class all \part and \chapter are set to start on a recto page.

from book.cls:

\newcommand\part{%
  \if@openright
    \cleardoublepage
  \else
    \clearpage
  \fi
  \thispagestyle{plain}%
  \if@twocolumn
    \onecolumn
    \@tempswatrue
  \else
    \@tempswafalse
  \fi
  \null\vfil
  \secdef\@part\@spart}

you should be able to renew that command, and something similar for the \chapter.

Passing data to a jQuery UI Dialog

Just give you some idea may help you, if you want fully control dialog, you can try to avoid use of default button options, and add buttons by yourself in your #dialog div. You also can put data into some dummy attribute of link, like Click. call attr("data") when you need it.

SQL ORDER BY multiple columns

The results are ordered by the first column, then the second, and so on for as many columns as the ORDER BY clause includes. If you want any results sorted in descending order, your ORDER BY clause must use the DESC keyword directly after the name or the number of the relevant column.

Check out this Example

SELECT first_name, last_name, hire_date, salary 
FROM employee 
ORDER BY hire_date DESC,last_name ASC;

It will order in succession. Order the Hire_Date first, then LAST_NAME it by Hire_Date .

How to find column names for all tables in all databases in SQL Server

Minor refinement on KM's solution for those like me who've got collation fun on their DB server....

DECLARE @SQL varchar(max)=''

SELECT @SQL=@SQL+'UNION
select 
'''+d.name +'.''+sh.name+''.''+o.name COLLATE SQL_Latin1_General_CP1_CI_AS,c.name COLLATE SQL_Latin1_General_CP1_CI_AS,c.column_id
from '+d.name +'.sys.columns            c
    inner join sys.objects  o on c.object_id=o.object_id
    INNER JOIN sys.schemas  sh on o.schema_id=sh.schema_id
'
FROM sys.databases d

SELECT @SQL=RIGHT(@SQL,LEN(@SQL)-5)+'order by 1,3'
--print @SQL

EXEC (@SQL)

(Still living in hope that we'll find a way to do this that can be wrapped into a view.)

Scheduled run of stored procedure on SQL server

If MS SQL Server Express Edition is being used then SQL Server Agent is not available. I found the following worked for all editions:

USE Master
GO

IF  EXISTS( SELECT *
            FROM sys.objects
            WHERE object_id = OBJECT_ID(N'[dbo].[MyBackgroundTask]')
            AND type in (N'P', N'PC'))
    DROP PROCEDURE [dbo].[MyBackgroundTask]
GO

CREATE PROCEDURE MyBackgroundTask
AS
BEGIN
    -- SET NOCOUNT ON added to prevent extra result sets from
    -- interfering with SELECT statements.
    SET NOCOUNT ON;

    -- The interval between cleanup attempts
    declare @timeToRun nvarchar(50)
    set @timeToRun = '03:33:33'

    while 1 = 1
    begin
        waitfor time @timeToRun
        begin
            execute [MyDatabaseName].[dbo].[MyDatabaseStoredProcedure];
        end
    end
END
GO

-- Run the procedure when the master database starts.
sp_procoption    @ProcName = 'MyBackgroundTask',
                @OptionName = 'startup',
                @OptionValue = 'on'
GO

Some notes:

Getting the application's directory from a WPF application

Here is another:

System.Reflection.Assembly.GetExecutingAssembly().Location

Div with margin-left and width:100% overflowing on the right side

Just remove the width from both divs.

A div is a block level element and will use all available space (unless you start floating or positioning them) so the outer div will automatically be 100% wide and the inner div will use all remaining space after setting the left margin.

I have added an example with a textarea on jsfiddle.

Updated example with an input.

How to create a temporary directory?

Here is a simple explanation about how to create a temp dir using templates.

  1. Creates a temporary file or directory, safely, and prints its name.
  2. TEMPLATE must contain at least 3 consecutive 'X's in last component.
  3. If TEMPLATE is not specified, it will use tmp.XXXXXXXXXX
  4. directories created are u+rwx, minus umask restrictions.

PARENT_DIR=./temp_dirs # (optional) specify a dir for your tempdirs
mkdir $PARENT_DIR

TEMPLATE_PREFIX='tmp' # prefix of your new tempdir template
TEMPLATE_RANDOM='XXXX' # Increase the Xs for more random characters
TEMPLATE=${PARENT_DIR}/${TEMPLATE_PREFIX}.${TEMPLATE_RANDOM}

# create the tempdir using your custom $TEMPLATE, which may include
# a path such as a parent dir, and assign the new path to a var
NEW_TEMP_DIR_PATH=$(mktemp -d $TEMPLATE)
echo $NEW_TEMP_DIR_PATH

# create the tempdir in parent dir, using default template
# 'tmp.XXXXXXXXXX' and assign the new path to a var
NEW_TEMP_DIR_PATH=$(mktemp -p $PARENT_DIR)
echo $NEW_TEMP_DIR_PATH

# create a tempdir in your systems default tmp path e.g. /tmp 
# using the default template 'tmp.XXXXXXXXXX' and assign path to var
NEW_TEMP_DIR_PATH=$(mktemp -d)
echo $NEW_TEMP_DIR_PATH

# Do whatever you want with your generated temp dir and var holding its path

Cross-browser custom styling for file upload button

I'm posting this because (to my surprise) there was no other place I could find that recommended this.

There's a really easy way to do this, without restricting you to browser-defined input dimensions. Just use the <label> tag around a hidden file upload button. This allows for even more freedom in styling than the styling allowed via webkit's built-in styling[1].

The label tag was made for the exact purpose of directing any click events on it to the child inputs[2], so using that, you won't require any JavaScript to direct the click event to the input button for you anymore. You'd to use something like the following:

_x000D_
_x000D_
label.myLabel input[type="file"] {_x000D_
    position:absolute;_x000D_
    top: -1000px;_x000D_
}_x000D_
_x000D_
/***** Example custom styling *****/_x000D_
.myLabel {_x000D_
    border: 2px solid #AAA;_x000D_
    border-radius: 4px;_x000D_
    padding: 2px 5px;_x000D_
    margin: 2px;_x000D_
    background: #DDD;_x000D_
    display: inline-block;_x000D_
}_x000D_
.myLabel:hover {_x000D_
    background: #CCC;_x000D_
}_x000D_
.myLabel:active {_x000D_
    background: #CCF;_x000D_
}_x000D_
.myLabel :invalid + span {_x000D_
    color: #A44;_x000D_
}_x000D_
.myLabel :valid + span {_x000D_
    color: #4A4;_x000D_
}
_x000D_
<label class="myLabel">_x000D_
    <input type="file" required/>_x000D_
    <span>My Label</span>_x000D_
</label>
_x000D_
_x000D_
_x000D_

I've used a fixed position to hide the input, to make it work even in ancient versions of Internet Explorer (emulated IE8- refused to work on a visibility:hidden or display:none file-input). I've tested in emulated IE7 and up, and it worked perfectly.


  1. You can't use <button>s inside <label> tags unfortunately, so you'll have to define the styles for the buttons yourself. To me, this is the only downside to this approach.
  2. If the for attribute is defined, its value is used to trigger the input with the same id as the for attribute on the <label>.

How to select records from last 24 hours using SQL?

In Oracle (For last 24 hours):

SELECT  *
FROM    my_table
WHERE   date_column >= SYSDATE - 24/24

In case, for any reason, you have rows with future dates, you can use between, like this:

SELECT  *
FROM    my_table
WHERE   date_column BETWEEN (SYSDATE - 24/24) AND SYSDATE

How to run ssh-add on windows?

One could install Git for Windows and subsequently run ssh-add:

Step 3: Add your key to the ssh-agent

To configure the ssh-agent program to use your SSH key:

If you have GitHub for Windows installed, you can use it to clone repositories and not deal with SSH keys. It also comes with the Git Bash tool, which is the preferred way of running git commands on Windows.

  1. Ensure ssh-agent is enabled:

    • If you are using Git Bash, turn on ssh-agent:

      # start the ssh-agent in the background
      ssh-agent -s
      # Agent pid 59566
      
    • If you are using another terminal prompt, such as msysgit, turn on ssh-agent:

      # start the ssh-agent in the background
      eval $(ssh-agent -s)
      # Agent pid 59566
      
  2. Add your SSH key to the ssh-agent:

    ssh-add ~/.ssh/id_rsa
    

Write objects into file with Node.js

Building on what deb2fast said I would also pass in a couple of extra parameters to JSON.stringify() to get it to pretty format:

fs.writeFileSync('./data.json', JSON.stringify(obj, null, 2) , 'utf-8');

The second param is an optional replacer function which you don't need in this case so null works.

The third param is the number of spaces to use for indentation. 2 and 4 seem to be popular choices.

Using custom fonts using CSS?

Today there are four font container formats in use on the web: EOT, TTF, WOFF,andWOFF2.

Unfortunately, despite the wide range of choices, there isn't a single universal format that works across all old and new browsers:

  • EOT is IE only,
  • TTF has partial IE support,
  • WOFF enjoys the widest support but is not available in some older browsers
  • WOFF 2.0 support is a work in progress for many browsers.

If you want your web app to have the same font across all browsers then you might want to provide all 4 font type in CSS

 @font-face {
      font-family: 'besom'; !important
      src: url('fonts/besom/besom.eot');
      src: url('fonts/besom/besom.eot?#iefix') format('embedded-opentype'),
           url('fonts/besom/besom.woff2') format('woff2'),
           url('fonts/besom/besom.woff') format('woff'),
           url('fonts/besom/besom.ttf') format('truetype'),
           url('fonts/besom/besom.svg#besom_2regular') format('svg');
      font-weight: normal;
      font-style: normal;
  }

ADB.exe is obsolete and has serious performance problems

In my case what removed this message was (After updating everything) deleting the emulator and creating a new one. Manually updating the adb didn't solved this for. Nor updating via the Android studio Gui. In my case it seems that since the emulator was created with "old" components it keep showing the message. I had three emulators, just deleted them all and created a new one. For my surprise when it started the message was no more.

Cannot tell if performance is better or not. The message just didn't came up. Also I have everything updated to the latest (emulators and sdk).

Gradle Sync failed could not find constraint-layout:1.0.0-alpha2

I updated my android gradle plugin to 2.2.0-alpha4 and constraint layout dependency to 1.0.0-alpha3 and it seems to be working now

how to get the current working directory's absolute path from irb

If you want to get the full path of the directory of the current rb file:

File.expand_path('../', __FILE__)

PHP: How to check if a date is today, yesterday or tomorrow

<?php 
 $current = strtotime(date("Y-m-d"));
 $date    = strtotime("2014-09-05");

 $datediff = $date - $current;
 $difference = floor($datediff/(60*60*24));
 if($difference==0)
 {
    echo 'today';
 }
 else if($difference > 1)
 {
    echo 'Future Date';
 }
 else if($difference > 0)
 {
    echo 'tomorrow';
 }
 else if($difference < -1)
 {
    echo 'Long Back';
 }
 else
 {
    echo 'yesterday';
 }  
?>

Can a CSS class inherit one or more other classes?

Don't forget:

div.something.else {

    // will only style a div with both, not just one or the other

}

Initializing a member array in constructor initializer

How about

...
  C() : arr{ {1,2,3} }
{}
...

?

Compiles fine on g++ 4.8

What does getActivity() mean?

I to had a similar doubt what I got to know was getActivity() returns the Activity to which the fragment is associated.

The getActivity() method is used generally in static fragment as the associated activity will not be static and non static member cannot be used in static member.

I used <code>getActivity()</code> here to get non-static activity to which the the placeholder fragment is associated.

jQuery form input select by id

If you have more than one element with the same ID, then you have invalid HTML.

But you can acheive the same result using classes instead. That's what they're designed for.

<input class='b' ... >

You can give it an ID as well if you need to, but it should be unique.

Once you've got the class in there, you can reference it with a dot instead of the hash, like so:

var value = $('#a .b').val();

or

var value = $('#a input.b').val();

which will limit it to 'b' class elements that are inputs within the form (which seems to be close to what you're asking for).

Replace multiple characters in a C# string

Performance-Wise this probably might not be the best solution but it works.

var str = "filename:with&bad$separators.txt";
char[] charArray = new char[] { '#', '%', '&', '{', '}', '\\', '<', '>', '*', '?', '/', ' ', '$', '!', '\'', '"', ':', '@' };
foreach (var singleChar in charArray)
{
   str = str.Replace(singleChar, '_');
}

Java Timer vs ExecutorService?

From Oracle documentation page on ScheduledThreadPoolExecutor

A ThreadPoolExecutor that can additionally schedule commands to run after a given delay, or to execute periodically. This class is preferable to Timer when multiple worker threads are needed, or when the additional flexibility or capabilities of ThreadPoolExecutor (which this class extends) are required.

ExecutorService/ThreadPoolExecutor or ScheduledThreadPoolExecutor is obvious choice when you have multiple worker threads.

Pros of ExecutorService over Timer

  1. Timer can't take advantage of available CPU cores unlike ExecutorService especially with multiple tasks using flavours of ExecutorService like ForkJoinPool
  2. ExecutorService provides collaborative API if you need coordination between multiple tasks. Assume that you have to submit N number of worker tasks and wait for completion of all of them. You can easily achieve it with invokeAll API. If you want to achieve the same with multiple Timer tasks, it would be not simple.
  3. ThreadPoolExecutor provides better API for management of Thread life cycle.

    Thread pools address two different problems: they usually provide improved performance when executing large numbers of asynchronous tasks, due to reduced per-task invocation overhead, and they provide a means of bounding and managing the resources, including threads, consumed when executing a collection of tasks. Each ThreadPoolExecutor also maintains some basic statistics, such as the number of completed tasks

    Few advantages:

    a. You can create/manage/control life cycle of Threads & optimize thread creation cost overheads

    b. You can control processing of tasks ( Work Stealing, ForkJoinPool, invokeAll) etc.

    c. You can monitor the progress and health of threads

    d. Provides better exception handling mechanism

How to get the path of current worksheet in VBA?

The quickest way

path = ThisWorkbook.Path & "\"

Is there a goto statement in Java?

The keyword exists, but it is not implemented.

The only good reason to use goto that I can think of is this:

for (int i = 0; i < MAX_I; i++) {
    for (int j = 0; j < MAX_J; j++) {
        // do stuff
        goto outsideloops; // to break out of both loops
    }
}
outsideloops:

In Java you can do this like this:

loops:
for (int i = 0; i < MAX_I; i++) {
    for (int j = 0; j < MAX_J; j++) {
        // do stuff
        break loops;
    }
}

What is the difference between __str__ and __repr__?

Q: What's the difference between __str__() and __repr__()?

TL;DR: Differences between str()/repr() and __str__()/__repr__()

LONG

This question has been around a long time, and there are a variety of answers of which most are correct (not to mention from several Python community legends[!]). However when it comes down to the nitty-gritty, this question is analogous to asking for the difference between the str() and repr() built-in functions. I'm going to describe the differences in my own words (which means I may be "borrowing" liberally from Core Python Programming so pls forgive me).

Both str() and repr() have the same basic job: their goal is to return a string representation of a Python object. What kind of string representation is what differentiates them.

  • str() & __str()__ return a printable string representation of an object... something human-readable/for human consumption
  • repr() & __repr()__ return a string representation of an object that is a valid Python object, something you can pass to eval() or type into the Python shell without getting an error.

For example, let's assign a string to x and an int to y:

>>> x, y = 'foo', 123
>>> str(x), str(y)
('foo', '123')

Can we take what's inside the quotes and enter them verbatim into the Python interpreter?

>>> 123
123
>>> foo
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
NameError: name 'foo' is not defined

Clearly you can for an int but not necessarily for a str. While I can pass '123' to eval(), that doesn't work for 'foo':

>>> eval('123')
123
>>> eval('foo')
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "<string>", line 1, in <module>
NameError: name 'foo' is not defined

Now let's try repr(); again, dump what's in the pair of quotes for each string:

>>> repr(x), repr(y)
("'foo'", '123')
>>> 123
123
>>> 'foo'
'foo'

Wow, they both work? That's because 'foo', while a printable string representation of that string, it's not evaluatable, but "'foo'" is. 123 is a valid Python int called by either str() or repr(). What happens when we call eval() with these?

>>> eval('123')
123
>>> eval("'foo'")
'foo'

It works because 123 and 'foo' are valid Python objects. Another key takeaway is that while sometimes both return the same thing (the same string representation), that's not always the case. (And yes, yes, I can go create a variable foo where the eval() works, but that's not the point.)

More factoids about both pairs

  1. Sometimes, str() and repr() are called implicitly, meaning they're called on behalf of users: when users execute print (Py1/Py2) or call print() (Py3+), even if users don't call str() explicitly, such a call is made on their behalf before the object is displayed.
  2. In the Python shell (interactive interpreter), if you enter a variable at the >>> prompt and press RETURN, the interpreter displays the results of repr() implicitly called on that object.
  3. To connect str() and repr() to __str__() and __repr__(), realize that calls to the built-in functions, i.e., str(x) or repr(y) result in calling their object's corresponding special methods: x.__str__() or y.__repr()__
  4. By implementing __str__() and __repr__() for your Python classes, you overload the built-in functions (str() and repr()), allowing instances of your classes to be passed in to str() and repr(). When such calls are made, they turn around and call the class' __str__() and __repr__() (per #3).

Angular2 Material Dialog css, dialog size

On smaller screen's like laptop the dialog will shrink. To auto-fix, try the following option

http://answersicouldntfindanywhereelse.blogspot.com/2018/05/angular-material-full-size-dialog-on.html

Additional Reading https://material.angular.io/cdk/layout/overview

Thanks to the solution in answersicouldntfindanywhereelse (2nd para). it worked for me.

Following is needed

import { Breakpoints, BreakpointObserver } from '@angular/cdk/layout'

Unknown lifecycle phase "mvn". You must specify a valid lifecycle phase or a goal in the format <plugin-prefix>:<goal> or <plugin-group-id>

I was getting the same error. I was using Intellij IDEA and I wanted to run Spring boot application. So, solution from my side is as follow.

Go to Run menu -> Run configuration -> Click on Add button from the left panel and select maven -> In parameters add this text -> spring-boot:run

Now press Ok and Run.

'setInterval' vs 'setTimeout'

setInterval()

setInterval is a time interval based code execution method that has the native ability to repeatedly run specified script when the interval is reached. It should not be nested into its callback function by the script author to make it loop, since it loops by default. It will keep firing at the interval unless you call clearInterval().

if you want to loop code for animations or clocks Then use setInterval.

function doStuff() {
alert("run your code here when time interval is reached");
}
var myTimer = setInterval(doStuff, 5000);

setTimeout()

setTimeout is a time based code execution method that will execute script only one time when the interval is reached, and not repeat again unless you gear it to loop the script by nesting the setTimeout object inside of the function it calls to run. If geared to loop, it will keep firing at the interval unless you call clearTimeout().

function doStuff() {
alert("run your code here when time interval is reached");
}
var myTimer = setTimeout(doStuff, 5000);

if you want something to happen one time after some seconds Then use setTimeout... because it only executes one time when the interval is reached.

loop through json array jquery

You have to parse the string as JSON (data[0] == "[" is an indication that data is actually a string, not an object):

data = $.parseJSON(data);
$.each(data, function(i, item) {
    alert(item);
});

Selecting/excluding sets of columns in pandas

Also have a look into the built-in DataFrame.filter function.

Minimalistic but greedy approach (sufficient for the given df):

df.filter(regex="[^BD]")

Conservative/lazy approach (exact matches only):

df.filter(regex="^(?!(B|D)$).*$")

Conservative and generic:

exclude_cols = ['B','C']
df.filter(regex="^(?!({0})$).*$".format('|'.join(exclude_cols)))

Replace a newline in TSQL

To @Cerebrus solution: for H2 for strings "+" is not supported. So:

REPLACE(string, CHAR(13) || CHAR(10), 'replacementString')

How to detect a docker daemon port

By default, the docker daemon will use the unix socket unix:///var/run/docker.sock (you can check this is the case for you by doing a sudo netstat -tunlp and note that there is no docker daemon process listening on any ports). It's recommended to keep this setting for security reasons but it sounds like Riak requires the daemon to be running on a TCP socket.

To start the docker daemon with a TCP socket that anybody can connect to, use the -H option:

sudo docker -H 0.0.0.0:2375 -d &

Warning: This means machines that can talk to the daemon through that TCP socket can get root access to your host machine.

Related docs:

http://basho.com/posts/technical/running-riak-in-docker/

https://docs.docker.com/install/linux/linux-postinstall/#configure-where-the-docker-daemon-listens-for-connections

Overlaying histograms with ggplot2 in R

Using @joran's sample data,

ggplot(dat, aes(x=xx, fill=yy)) + geom_histogram(alpha=0.2, position="identity")

note that the default position of geom_histogram is "stack."

see "position adjustment" of this page:

docs.ggplot2.org/current/geom_histogram.html

Is there a way to make text unselectable on an HTML page?

Images can be selected too.

There are limits to using JavaScript to deselect text, as it might happen even in places where you want to select. To ensure a rich and successful career, steer clear of all requirements that need ability to influence or manage the browser beyond the ordinary... unless, of course, they are paying you extremely well.

Can I restore a single table from a full mysql mysqldump file?

This can be done more easily? This is how I did it:

Create a temporary database (e.g. restore):

mysqladmin -u root -p create restore

Restore the full dump in the temp database:

mysql -u root -p restore < fulldump.sql

Dump the table you want to recover:

mysqldump restore mytable > mytable.sql

Import the table in another database:

mysql -u root -p database < mytable.sql

Python: maximum recursion depth exceeded while calling a Python object

Python don't have a great support for recursion because of it's lack of TRE (Tail Recursion Elimination).

This means that each call to your recursive function will create a function call stack and because there is a limit of stack depth (by default is 1000) that you can check out by sys.getrecursionlimit (of course you can change it using sys.setrecursionlimit but it's not recommended) your program will end up by crashing when it hits this limit.

As other answer has already give you a much nicer way for how to solve this in your case (which is to replace recursion by simple loop) there is another solution if you still want to use recursion which is to use one of the many recipes of implementing TRE in python like this one.

N.B: My answer is meant to give you more insight on why you get the error, and I'm not advising you to use the TRE as i already explained because in your case a loop will be much better and easy to read.

Leave out quotes when copying from cell

To keep line breaks when pasting in notepad, replace this line in the macro:

strTemp = ActiveCell.Value

by:

strTemp = Replace(ActiveCell.Value, Chr(10), vbCrLf)

dyld: Library not loaded: /usr/local/opt/openssl/lib/libssl.1.0.0.dylib

I had a similar issue and based on this and other comments here's what happened and worked:

? brew update && brew upgrade && brew install openssl
remote: Repository not found.
fatal: repository 'https://github.com/Homebrew/homebrew-dupes/' not found
Error: homebrew/homebrew-dupes does not exist! Run `brew untap homebrew/homebrew-dupes` to remove it.
...
? brew untap homebrew/homebrew-dupes
? brew update && brew upgrade && brew install openssl

This was after working on it for hours, but first time I saw the homebrew-dupes. Not sure how Homebrew knew what to install, but it seemed to install everything from scratch. macOS Catalina, zsh. I think the initial problem came because of Catalina

The error I was getting was:

dlopen(/Users/gscar/.gem/ruby/2.7.0/gems/pg-1.2.2/lib/pg_ext.bundle, 9): Library not loaded: /usr/local/opt/openssl/lib/libssl.1.0.0.dylib (LoadError)
  Referenced from: /usr/local/opt/postgresql/lib/libpq.5.dylib
  Reason: image not found - /Users/gscar/.gem/ruby/2.7.0/gems/pg-1.2.2/lib/pg_ext.bundle

Routing with multiple Get methods in ASP.NET Web API

After reading lots of answers finally I figured out.

First, I added 3 different routes into WebApiConfig.cs

public static void Register(HttpConfiguration config)
{
    // Web API configuration and services

    // Web API routes
    config.MapHttpAttributeRoutes();

    config.Routes.MapHttpRoute(
        name: "ApiById",
        routeTemplate: "api/{controller}/{id}",
        defaults: new { id = RouteParameter.Optional },
        constraints: new { id = @"^[0-9]+$" }
    );

    config.Routes.MapHttpRoute(
        name: "ApiByName",
        routeTemplate: "api/{controller}/{action}/{name}",
        defaults: null,
        constraints: new { name = @"^[a-z]+$" }
    );

    config.Routes.MapHttpRoute(
        name: "ApiByAction",
        routeTemplate: "api/{controller}/{action}",
        defaults: new { action = "Get" }
    );
}

Then, removed ActionName, Route, etc.. from the controller functions. So basically this is my controller;

// GET: api/Countries/5
[ResponseType(typeof(Countries))]
//[ActionName("CountryById")]
public async Task<IHttpActionResult> GetCountries(int id)
{
    Countries countries = await db.Countries.FindAsync(id);
    if (countries == null)
    {
        return NotFound();
    }

    return Ok(countries);
}

// GET: api/Countries/tur
//[ResponseType(typeof(Countries))]
////[Route("api/CountriesByName/{anyString}")]
////[ActionName("CountriesByName")]
//[HttpGet]
[ResponseType(typeof(Countries))]
//[ActionName("CountryByName")]
public async Task<IHttpActionResult> GetCountriesByName(string name)
{
    var countries = await db.Countries
            .Where(s=>s.Country.ToString().StartsWith(name))
            .ToListAsync();

    if (countries == null)
    {
        return NotFound();
    }

    return Ok(countries);
}

Now I am able to run with following url samples(with name and with id);

http://localhost:49787/api/Countries/GetCountriesByName/France

http://localhost:49787/api/Countries/1

How to use LINQ Distinct() with multiple fields

Employee emp1 = new Employee() { ID = 1, Name = "Narendra1", Salary = 11111, Experience = 3, Age = 30 };Employee emp2 = new Employee() { ID = 2, Name = "Narendra2", Salary = 21111, Experience = 10, Age = 38 };
Employee emp3 = new Employee() { ID = 3, Name = "Narendra3", Salary = 31111, Experience = 4, Age = 33 };
Employee emp4 = new Employee() { ID = 3, Name = "Narendra4", Salary = 41111, Experience = 7, Age = 33 };

List<Employee> lstEmployee = new List<Employee>();

lstEmployee.Add(emp1);
lstEmployee.Add(emp2);
lstEmployee.Add(emp3);
lstEmployee.Add(emp4);

var eemmppss=lstEmployee.Select(cc=>new {cc.ID,cc.Age}).Distinct();

How to use custom font in a project written in Android Studio

I think instead of downloading .ttf file we can use Google fonts. It's very easy to implements. only you have to follow these steps. step 1) Open layout.xml of your project and the select font family of text view in attributes (for reference screen shot is attached) enter image description here

step 2) The in font family select More fonts.. option if your font is not there. then you will see a new window will open, there you can type your required font & select the desired font from that list i.e) Regular, Bold, Italic etc.. as shown in below image. enter image description here

step 3) Then you will observe a font folder will be auto generated in /res folder having your selected fonts xml file.

enter image description here

Then you can directly use this font family in xml as

      android:fontFamily="@font/josefin_sans_bold"

or pro grammatically you can achieve this by using

  Typeface typeface = ResourcesCompat.getFont(this, R.font.app_font);
  fontText.setTypeface(typeface);

How to get the current time in YYYY-MM-DD HH:MI:Sec.Millisecond format in Java?

SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss.SSS");

test if event handler is bound to an element in jQuery

I wrote a very tiny plugin called "once" which do that:

$.fn.once = function(a, b) {
    return this.each(function() {
        $(this).off(a).on(a,b);
    });
};

And simply:

$(element).once('click', function(){
});

How do I jump to a closing bracket in Visual Studio Code?

Details that can benefit everyone (Linux/Win/Mac)

The command in the keyboard shortcuts menu/editor is editor.action.jumpToBracket there you can set it to whatever you like. There is also one called editor.action.selectToBracket which has no shortcut by default (at least on Mac).

Etc.

On the Mac editor.action.jumpToBracket starts out as Cmd+Shift+\ and I changed it to Ctrl+] because I didn't want a Shift in there and to be in line with what others here say works on Linux/Win. I did so in the hopes that I could use Ctrl+Shift+] to "Extend selection to matching bracket". That is what lead me to discover the details above. I set editor.action.selectToBracket to Ctrl+Shift+] and got exactly the behavior I wanted.

WAMP won't turn green. And the VCRUNTIME140.dll error

WAMP is not turning GREEN? Don`t panic

First of all check your windows update by searching "Windows Update"

or

Download updates from microsoft windows site (i had windows 7 x64 updated to service pack 1 full) windows 7 Service pack 1 download

Now there are some more downloads that support WAMP for installing time

From the readme.txt

BEFORE proceeding with the installation of Wampserver, you must ensure that certain elements are installed on your system, otherwise Wampserver will absolutely not run, and in addition, the installation will be faulty and you need to remove Wampserver BEFORE installing the elements that were missing.

Make sure you are "up to date" in the redistributable packages VC9, VC10, VC11, VC13 and VC14 Even if you think you are up to date, install each package as administrator and if message "Already installed", validate Repair.

The following packages (VC9, VC10, VC11) are imperatively required to Wampserver 2.4, 2.5 and 3.0, even if you use only Apache and PHP versions VC11 and VC14 is required for PHP 7 and Apache 2.4.17

VC9 Packages (Visual C++ 2008 SP1) https://www.microsoft.com/en-us/download/details.aspx?id=5582 https://www.microsoft.com/en-us/download/details.aspx?id=2092

VC10 Packages (Visual C++ 2010 SP1) https://www.microsoft.com/en-us/download/details.aspx?id=8328 https://www.microsoft.com/en-us/download/details.aspx?id=13523

VC11 Packages (Visual C++ 2012 Update 4) The two files VSU4\vcredist_x86.exe and VSU4\vcredist_x64.exe to be download are on the same page: http://www.microsoft.com/en-us/download/details.aspx?id=30679

VC13 Packages[/b] (Visual C++ 2013) The two files VSU4\vcredist_x86.exe and VSU4\vcredist_x64.exe

VC14 Packages (Visual C++ 2015) The two files vcredist_x86.exe and vcredist_x64.exe to be download are on the same page: https://www.microsoft.com/en-us/download/details.aspx?id=52685

VC Packages x64 (Visual C++ 2017)

https://support.microsoft.com/en-us/help/2977003/the-latest-supported-visual-c-downloads

What value could I insert into a bit type column?

Generally speaking, for boolean or bit data types, you would use 0 or 1 like so:

UPDATE tbl SET bitCol = 1 WHERE bitCol = 0

See also:

ModuleNotFoundError: No module named 'sklearn'

I've tried a lot of things but finally, including uninstall with the automated tools. So, I've uninstalled manually scikit-learn.

sudo rm -R /home/ubuntu/.local/lib/python3.6/site-packages/sklearn
sudo rm -R /home/ubuntu/.local/lib/python3.6/site-packages/scikit_learn-0.20.0-py3.6.egg-info

And re-install using pip

sudo pip3.6 install -U scikit-learn

Hope that can help someone else!

Push local Git repo to new remote including all branches and tags

I was in a process of switching from one version control service to another and needed to clone all repositories including all branches, tags and history.

To achieve above I did next:

  • manually checkout all branches to local repository (script to checkout all shown below),
  • git push origin '*:*'

.sh script used to checkout all branches to local repository:

for branch in `git branch -a | grep remotes | grep -v HEAD | grep -v master `; do
   git branch --track ${branch#remotes/origin/} $branch
done

jQuery changing font family and font size

Full working solution :

HTML:

<form id="myform">
    <button>erase</button>
    <select id="fs"> 
        <option value="Arial">Arial</option>
        <option value="Verdana ">Verdana </option>
        <option value="Impact ">Impact </option>
        <option value="Comic Sans MS">Comic Sans MS</option>
    </select>

    <select id="size">
        <option value="7">7</option>
        <option value="10">10</option>
        <option value="20">20</option>
        <option value="30">30</option>
    </select>
</form>

<br/>

<textarea class="changeMe">Text into textarea</textarea>
<div id="container" class="changeMe">
    <div id="float">
        <p>
            Text into container
        </p>
    </div>
</div>

jQuery:

$("#fs").change(function() {
    //alert($(this).val());
    $('.changeMe').css("font-family", $(this).val());

});

$("#size").change(function() {
    $('.changeMe').css("font-size", $(this).val() + "px");
});

Fiddle here: http://jsfiddle.net/AaT9b/

How to list physical disks?

GetLogicalDrives() enumerates all mounted disk partitions, not physical drives.

You can enumerate the drive letters with (or without) GetLogicalDrives, then call QueryDosDevice() to find out which physical drive the letter is mapped to.

Alternatively, you can decode the information in the registry at HKEY_LOCAL_MACHINE\SYSTEM\MountedDevices. The binary data encodings there are not obvious, however. If you have a copy of Russinovich and Solomon's book Microsoft Windows Internals, this registry hive is discussed in Chapter 10.

How to sort a file, based on its numerical values for a field?

Well, most other answers here refer to

sort -n

However, I'm not sure this works for negative numbers. Here are the results I get with sort version 6.10 on Fedora 9.

Input file:

-0.907928466796875
-0.61614990234375
1.135406494140625
0.48614501953125
-0.4140167236328125

Output:

-0.4140167236328125
0.48614501953125
-0.61614990234375
-0.907928466796875
1.135406494140625

Which is obviously not ordered by numeric value.

Then, I guess that a more precise answer would be to use sort -n but only if all the values are positive.

P.S.: Using sort -g returns just the same results for this example

Edit:

Looks like the locale settings affect how the minus sign affects the order (see here). In order to get proper results I just did:

LC_ALL=C sort -n filename.txt

NullPointerException: Attempt to invoke virtual method 'boolean java.lang.String.equalsIgnoreCase(java.lang.String)' on a null object reference

called_from must be null. Add a test against that condition like

if (called_from != null && called_from.equalsIgnoreCase("add")) {

or you could use Yoda conditions (per the Advantages in the linked Wikipedia article it can also solve some types of unsafe null behavior they can be described as placing the constant portion of the expression on the left side of the conditional statement)

if ("add".equalsIgnoreCase(called_from)) { // <-- safe if called_from is null

HTML table with fixed headers?

I was looking for a solution for this for a while and found most of the answers are not working or not suitable for my situation, so I wrote a simple solution with jQuery.

This is the solution outline:

  1. Clone the table that needs to have a fixed header, and place the cloned copy on top of the original.
  2. Remove the table body from top table.
  3. Remove the table header from bottom table.
  4. Adjust the column widths. (We keep track of the original column widths)

Below is the code in a runnable demo.

_x000D_
_x000D_
function scrolify(tblAsJQueryObject, height) {_x000D_
  var oTbl = tblAsJQueryObject;_x000D_
_x000D_
  // for very large tables you can remove the four lines below_x000D_
  // and wrap the table with <div> in the mark-up and assign_x000D_
  // height and overflow property  _x000D_
  var oTblDiv = $("<div/>");_x000D_
  oTblDiv.css('height', height);_x000D_
  oTblDiv.css('overflow', 'scroll');_x000D_
  oTbl.wrap(oTblDiv);_x000D_
_x000D_
  // save original width_x000D_
  oTbl.attr("data-item-original-width", oTbl.width());_x000D_
  oTbl.find('thead tr td').each(function() {_x000D_
    $(this).attr("data-item-original-width", $(this).width());_x000D_
  });_x000D_
  oTbl.find('tbody tr:eq(0) td').each(function() {_x000D_
    $(this).attr("data-item-original-width", $(this).width());_x000D_
  });_x000D_
_x000D_
_x000D_
  // clone the original table_x000D_
  var newTbl = oTbl.clone();_x000D_
_x000D_
  // remove table header from original table_x000D_
  oTbl.find('thead tr').remove();_x000D_
  // remove table body from new table_x000D_
  newTbl.find('tbody tr').remove();_x000D_
_x000D_
  oTbl.parent().parent().prepend(newTbl);_x000D_
  newTbl.wrap("<div/>");_x000D_
_x000D_
  // replace ORIGINAL COLUMN width    _x000D_
  newTbl.width(newTbl.attr('data-item-original-width'));_x000D_
  newTbl.find('thead tr td').each(function() {_x000D_
    $(this).width($(this).attr("data-item-original-width"));_x000D_
  });_x000D_
  oTbl.width(oTbl.attr('data-item-original-width'));_x000D_
  oTbl.find('tbody tr:eq(0) td').each(function() {_x000D_
    $(this).width($(this).attr("data-item-original-width"));_x000D_
  });_x000D_
}_x000D_
_x000D_
$(document).ready(function() {_x000D_
  scrolify($('#tblNeedsScrolling'), 160); // 160 is height_x000D_
});
_x000D_
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.6.4/jquery.min.js"></script>_x000D_
_x000D_
<div style="width:300px;border:6px green solid;">_x000D_
  <table border="1" width="100%" id="tblNeedsScrolling">_x000D_
    <thead>_x000D_
      <tr><th>Header 1</th><th>Header 2</th></tr>_x000D_
    </thead>_x000D_
    <tbody>_x000D_
      <tr><td>row 1, cell 1</td><td>row 1, cell 2</td></tr>_x000D_
      <tr><td>row 2, cell 1</td><td>row 2, cell 2</td></tr>_x000D_
      <tr><td>row 3, cell 1</td><td>row 3, cell 2</td></tr>_x000D_
      <tr><td>row 4, cell 1</td><td>row 4, cell 2</td></tr>   _x000D_
      <tr><td>row 5, cell 1</td><td>row 5, cell 2</td></tr>_x000D_
      <tr><td>row 6, cell 1</td><td>row 6, cell 2</td></tr>_x000D_
      <tr><td>row 7, cell 1</td><td>row 7, cell 2</td></tr>_x000D_
      <tr><td>row 8, cell 1</td><td>row 8, cell 2</td></tr>   _x000D_
    </tbody>_x000D_
  </table>_x000D_
</div>
_x000D_
_x000D_
_x000D_

This solution works in Chrome and IE. Since it is based on jQuery, this should work in other jQuery supported browsers as well.

What is Shelving in TFS?

Shelving has many uses. The main ones are:

  1. Context Switching: Saving the work on your current task so you can switch to another high priority task. Say you're working on a new feature, minding your own business, when your boss runs in and says "Ahhh! Bug Bug Bug!" and you have to drop your current changes on the feature and go fix the bug. You can shelve your work on the feature, fix the bug, then come back and unshelve to work on your changes later.
  2. Sharing Changesets: If you want to share a changeset of code without checking it in, you can make it easy for others to access by shelving it. This could be used when you are passing an incomplete task to someone else (poor soul) or if you have some sort of testing code you would never EVER check in that someone else needed to run. h/t to the other responses about using this for reviews, it is a very good idea.
  3. Saving your progress: While you're working on a complex feature, you may find yourself at a 'good point' where you would like to save your progress. This is an ideal time to shelve your code. Say you are hacking up some CSS / HTML to fix rendering bugs. Usually you bang on it, iterating every possible kludge you can think up until it looks right. However, once it looks right you may want to try and go back in to cleanup your markup so that someone else may be able to understand what you did before you check it in. In this case, you can shelve the code when everything renders right, then you are free to go and refactor your markup, knowing that if you accidentally break it again, you can always go back and get your changeset.

Any other uses?

How to enable TLS 1.2 support in an Android application (running on Android 4.1 JB)

I solved this issue following the indication provided in the article http://blog.dev-area.net/2015/08/13/android-4-1-enable-tls-1-1-and-tls-1-2/ with little changes.

SSLContext context = SSLContext.getInstance("TLS");
context.init(null, null, null);
SSLSocketFactory noSSLv3Factory = null;
if (Build.VERSION.SDK_INT <= Build.VERSION_CODES.KITKAT) {
    noSSLv3Factory = new TLSSocketFactory(sslContext.getSocketFactory());
} else {
    noSSLv3Factory = sslContext.getSocketFactory();
}
connection.setSSLSocketFactory(noSSLv3Factory);

This is the code of the custom TLSSocketFactory:

public static class TLSSocketFactory extends SSLSocketFactory {

    private SSLSocketFactory internalSSLSocketFactory;

    public TLSSocketFactory(SSLSocketFactory delegate) throws KeyManagementException, NoSuchAlgorithmException {
        internalSSLSocketFactory = delegate;
    }

    @Override
    public String[] getDefaultCipherSuites() {
        return internalSSLSocketFactory.getDefaultCipherSuites();
    }

    @Override
    public String[] getSupportedCipherSuites() {
        return internalSSLSocketFactory.getSupportedCipherSuites();
    }

    @Override
    public Socket createSocket(Socket s, String host, int port, boolean autoClose) throws IOException {
        return enableTLSOnSocket(internalSSLSocketFactory.createSocket(s, host, port, autoClose));
    }

    @Override
    public Socket createSocket(String host, int port) throws IOException, UnknownHostException {
        return enableTLSOnSocket(internalSSLSocketFactory.createSocket(host, port));
    }

    @Override
    public Socket createSocket(String host, int port, InetAddress localHost, int localPort) throws IOException, UnknownHostException {
        return enableTLSOnSocket(internalSSLSocketFactory.createSocket(host, port, localHost, localPort));
    }

    @Override
    public Socket createSocket(InetAddress host, int port) throws IOException {
        return enableTLSOnSocket(internalSSLSocketFactory.createSocket(host, port));
    }

    @Override
    public Socket createSocket(InetAddress address, int port, InetAddress localAddress, int localPort) throws IOException {
        return enableTLSOnSocket(internalSSLSocketFactory.createSocket(address, port, localAddress, localPort));
    }

    /*
     * Utility methods
     */

    private static Socket enableTLSOnSocket(Socket socket) {
        if (socket != null && (socket instanceof SSLSocket)
                && isTLSServerEnabled((SSLSocket) socket)) { // skip the fix if server doesn't provide there TLS version
            ((SSLSocket) socket).setEnabledProtocols(new String[]{TLS_v1_1, TLS_v1_2});
        }
        return socket;
    }

    private static boolean isTLSServerEnabled(SSLSocket sslSocket) {
        System.out.println("__prova__ :: " + sslSocket.getSupportedProtocols().toString());
        for (String protocol : sslSocket.getSupportedProtocols()) {
            if (protocol.equals(TLS_v1_1) || protocol.equals(TLS_v1_2)) {
                return true;
            }
        }
        return false;
    }
}

Edit: Thank's to ademar111190 for the kotlin implementation (link)

class TLSSocketFactory constructor(
        private val internalSSLSocketFactory: SSLSocketFactory
) : SSLSocketFactory() {

    private val protocols = arrayOf("TLSv1.2", "TLSv1.1")

    override fun getDefaultCipherSuites(): Array<String> = internalSSLSocketFactory.defaultCipherSuites

    override fun getSupportedCipherSuites(): Array<String> = internalSSLSocketFactory.supportedCipherSuites

    override fun createSocket(s: Socket, host: String, port: Int, autoClose: Boolean) =
            enableTLSOnSocket(internalSSLSocketFactory.createSocket(s, host, port, autoClose))

    override fun createSocket(host: String, port: Int) =
            enableTLSOnSocket(internalSSLSocketFactory.createSocket(host, port))

    override fun createSocket(host: String, port: Int, localHost: InetAddress, localPort: Int) =
            enableTLSOnSocket(internalSSLSocketFactory.createSocket(host, port, localHost, localPort))

    override fun createSocket(host: InetAddress, port: Int) =
            enableTLSOnSocket(internalSSLSocketFactory.createSocket(host, port))

    override fun createSocket(address: InetAddress, port: Int, localAddress: InetAddress, localPort: Int) =
            enableTLSOnSocket(internalSSLSocketFactory.createSocket(address, port, localAddress, localPort))

    private fun enableTLSOnSocket(socket: Socket?) = socket?.apply {
        if (this is SSLSocket && isTLSServerEnabled(this)) {
            enabledProtocols = protocols
        }
    }

    private fun isTLSServerEnabled(sslSocket: SSLSocket) = sslSocket.supportedProtocols.any { it in protocols }

}

OWIN Startup Class Missing

This could be faced in Visual Studio 2015 as well when you use the Azure AD with a MVC project. Here it create the startup file as Startup.Auth.cs in App_Start folder but it will be missing the

[assembly: OwinStartup(typeof(MyWebApp.Startup))]

So add it and you should be good to go. This goes before the namespace start.

How to change the session timeout in PHP?

Just a notice for a sharing hosting server or added on domains =

For your settings to work you must have a different save session dir for added domain by using php_value session.save_path folderA/sessionsA.

So create a folder to your root server, not into the public_html and not to be publicity accessed from outside. For my cpanel/server worked fine the folder permissions 0700. Give a try...

# Session timeout, 2628000 sec = 1 month, 604800 = 1 week, 57600 = 16 hours, 86400 = 1 day
ini_set('session.save_path', '/home/server/.folderA_sessionsA');
ini_set('session.gc_maxlifetime', 57600); 
ini_set('session.cookie_lifetime', 57600);
# session.cache_expire is in minutes unlike the other settings above         
ini_set('session.cache_expire', 960);
ini_set('session.name', 'MyDomainA');

before session_start();

or put this in your .htaccess file.

php_value session.save_path /home/server/.folderA_sessionsA
php_value session.gc_maxlifetime 57600
php_value session.cookie_lifetime 57600
php_value session.cache_expire 57600
php_value session.name MyDomainA

After many researching and testing this worked fine for shared cpanel/php7 server. Many thanks to: NoiS

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

Yes, they are different...

# is an id selector, used to target a single specific element with a unique id, but . is a class selector used to target multiple elements with a particular class. To put it another way:

  • #foo {} will style the single element declared with an attribute id="foo"
  • .foo {} will style all elements with an attribute class="foo" (you can have multiple classes assigned to an element too, just separate them with spaces, e.g. class="foo bar")

Typical uses

Generally speaking, you use # for styling something you know is only going to appear once, for example, things like high level layout divs such sidebars, banner areas etc.

Classes are used where the style is repeated, e.g. say you head a special form of header for error messages, you could create a style h1.error {} which would only apply to <h1 class="error">

Specificity

Another aspect where selectors differ is in their specificity - an id selector is deemed to be more specific than class selector. This means that where styles conflict on an element, the ones defined with the more specific selector will override less specific selectors. For example, given <div id="sidebar" class="box"> any rules for #sidebar with override conflicting rules for .box

Learn more about CSS selectors

See Selectutorial for more great primers on CSS selectors - they are incredibly powerful, and if your conception is simply that "# is used for DIVs" you'd do well to read up on exactly how to use CSS more effectively.

EDIT: Looks like Selectutorial might have gone to the big website in the sky, so try this archive link instead.

What is the difference between state and props in React?

  • props --- you can not change its value.
  • states --- you can change its value in your code, but it would be active when a render happens.

Angularjs if-then-else construction in expression

Angular expressions do not support the ternary operator before 1.1.5, but it can be emulated like this:

condition && (answer if true) || (answer if false)

So in example, something like this would work:

<div ng-repeater="item in items">
    <div>{{item.description}}</div>
    <div>{{isExists(item) && 'available' || 'oh no, you don't have it'}}</div>
</div>

UPDATE: Angular 1.1.5 added support for ternary operators:

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

Error: Could not create the Java Virtual Machine Mac OSX Mavericks

Try : java -version , then if you see java 11

try to delete with terminal : cd /Library/Java/JavaVirtualMachines rm -rf openjdk-11.0.1.jdk

if it doesn't try delete manually: 1) click on finder 2) go to folder 3) post /Library/Java/JavaVirtualMachines 4) delete java 11 .

then try java version and you will see : java version "1.8.0_191"

JTable won't show column headers

    public table2() {
    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    setBounds(100, 100, 485, 218);
    setTitle("jtable");
    getContentPane().setLayout(null);

    String data[][] = { { "Row1/1", "Row1/2", "Row1/3" },
            { "Row2/1", "Row2/2", "Row2/3" },
            { "Row3/1", "Row3/2", "Row3/3" },
            { "Row4/1", "Row4/2", "Row4/3" }, };

    String header[] = { "Column 1", "Column 2", "Column 3" };

    // Table
    JTable table = new JTable(data,header);


    // ScrollPane
    JScrollPane scrollPane = new JScrollPane(table);
    scrollPane.setBounds(36, 37, 407, 79);
    getContentPane().add(scrollPane);

   }

}

try this!!

C# nullable string error

System.String is a reference type and already "nullable".

Nullable<T> and the ? suffix are for value types such as Int32, Double, DateTime, etc.

Jquery: Find Text and replace

How to change multiple "dogsss" to "dollsss":

$('#id1 p').each(function() {
var text = $(this).text();
// Use global flag i.e. g in the regex to replace all occurrences
$(this).text(text.replace(/dog/g, 'doll'));
});

https://jsfiddle.net/ashjpb9w/

SQL Query to find missing rows between two related tables

SELECT A.ABC_ID, A.VAL FROM A WHERE NOT EXISTS 
   (SELECT * FROM B WHERE B.ABC_ID = A.ABC_ID AND B.VAL = A.VAL)

or

SELECT A.ABC_ID, A.VAL FROM A WHERE VAL NOT IN 
    (SELECT VAL FROM B WHERE B.ABC_ID = A.ABC_ID)

or

SELECT A.ABC_ID, A.VAL LEFT OUTER JOIN B 
    ON A.ABC_ID = B.ABC_ID AND A.VAL = B.VAL FROM A WHERE B.VAL IS NULL

Please note that these queries do not require that ABC_ID be in table B at all. I think that does what you want.

How can I get the current class of a div with jQuery?

var classname=$('#div1').attr('class')

Validating an XML against referenced XSD in C#

personally I favor validating without a callback:

public bool ValidateSchema(string xmlPath, string xsdPath)
{
    XmlDocument xml = new XmlDocument();
    xml.Load(xmlPath);

    xml.Schemas.Add(null, xsdPath);

    try
    {
        xml.Validate(null);
    }
    catch (XmlSchemaValidationException)
    {
        return false;
    }
    return true;
}

(see Timiz0r's post in Synchronous XML Schema Validation? .NET 3.5)

Use child_process.execSync but keep output in console

You can simply use .toString().

var result = require('child_process').execSync('rsync -avAXz --info=progress2 "/src" "/dest"').toString();
console.log(result);

This has been tested on Node v8.5.0, I'm not sure about previous versions. According to @etov, it doesn't work on v6.3.1 - I'm not sure about in-between.


Edit: Looking back on this, I've realised that it doesn't actually answer the specific question because it doesn't show the output to you 'live' — only once the command has finished running.

However, I'm leaving this answer here because I know quite a few people come across this question just looking for how to print the result of the command after execution.

Command copy exited with code 4 when building - Visual Studio restart solves it

I got this error because of the file was opened in another instance.

when i closed the file and again re-build the solution, it was successfully copied.

How to split a data frame?

You could also use

data2 <- data[data$sum_points == 2500, ]

This will make a dataframe with the values where sum_points = 2500

It gives :

airfoils sum_points field_points   init_t contour_t   field_t
...
491        5       2500         5625 0.000086  0.004272  6.321774
498        5       2500         5625 0.000087  0.004507  6.325083
504        5       2500         5625 0.000088  0.004370  6.336034
603        5        250        10000 0.000072  0.000525  1.111278
577        5        250        10000 0.000104  0.000559  1.111431
587        5        250        10000 0.000072  0.000528  1.111524
606        5        250        10000 0.000079  0.000538  1.111685
....
> data2 <- data[data$sum_points == 2500, ]
> data2
airfoils sum_points field_points   init_t contour_t   field_t
108        5       2500          625 0.000082  0.004329  0.733109
106        5       2500          625 0.000102  0.004564  0.733243
117        5       2500          625 0.000087  0.004321  0.733274
112        5       2500          625 0.000081  0.004428  0.733587

How to do an Integer.parseInt() for a decimal number?

Use,

String s="0.01";
int i= new Double(s).intValue();

dismissModalViewControllerAnimated deprecated

[self dismissModalViewControllerAnimated:NO]; has been deprecated.

Use [self dismissViewControllerAnimated:NO completion:nil]; instead.

Escape text for HTML

If you're using .NET 4 or above and you don't want to reference System.Web, you can use WebUtility.HtmlEncode from System

var encoded = WebUtility.HtmlEncode(unencoded);

This has the same effect as HttpUtility.HtmlEncode and should be preferred over System.Security.SecurityElement.Escape.

PowerShell and the -contains operator

The -Contains operator doesn't do substring comparisons and the match must be on a complete string and is used to search collections.

From the documentation you linked to:

-Contains Description: Containment operator. Tells whether a collection of reference values includes a single test value.

In the example you provided you're working with a collection containing just one string item.

If you read the documentation you linked to you'll see an example that demonstrates this behaviour:

Examples:

PS C:\> "abc", "def" -Contains "def"
True

PS C:\> "Windows", "PowerShell" -Contains "Shell"
False  #Not an exact match

I think what you want is the -Match operator:

"12-18" -Match "-"

Which returns True.

Important: As pointed out in the comments and in the linked documentation, it should be noted that the -Match operator uses regular expressions to perform text matching.

This Row already belongs to another table error when trying to add rows?

Why don't you just use CopyToDataTable

DataTable dt = (DataTable)Session["dtAllOrders"];
DataTable dtSpecificOrders = new DataTable();

DataTable orderRows = dt.Select("CustomerID = 2").CopyToDataTable();

How do you get the logical xor of two variables in Python?

If you're already normalizing the inputs to booleans, then != is xor.

bool(a) != bool(b)

Pandas: ValueError: cannot convert float NaN to integer

if you have null value then in doing mathematical operation you will get this error to resolve it use df[~df['x'].isnull()]df[['x']].astype(int) if you want your dataset to be unchangeable.

How do I convert a String to an int in Java?

Apart from the previous answers, I would like to add several functions. These are results while you use them:

public static void main(String[] args) {
  System.out.println(parseIntOrDefault("123", 0)); // 123
  System.out.println(parseIntOrDefault("aaa", 0)); // 0
  System.out.println(parseIntOrDefault("aaa456", 3, 0)); // 456
  System.out.println(parseIntOrDefault("aaa789bbb", 3, 6, 0)); // 789
}

Implementation:

public static int parseIntOrDefault(String value, int defaultValue) {
  int result = defaultValue;
  try {
    result = Integer.parseInt(value);
  }
  catch (Exception e) {
  }
  return result;
}

public static int parseIntOrDefault(String value, int beginIndex, int defaultValue) {
  int result = defaultValue;
  try {
    String stringValue = value.substring(beginIndex);
    result = Integer.parseInt(stringValue);
  }
  catch (Exception e) {
  }
  return result;
}

public static int parseIntOrDefault(String value, int beginIndex, int endIndex, int defaultValue) {
  int result = defaultValue;
  try {
    String stringValue = value.substring(beginIndex, endIndex);
    result = Integer.parseInt(stringValue);
  }
  catch (Exception e) {
  }
  return result;
}

The difference between the Runnable and Callable interfaces in Java

Callable interface declares call() method and you need to provide generics as type of Object call() should return -

public interface Callable<V> {
    /**
     * Computes a result, or throws an exception if unable to do so.
     *
     * @return computed result
     * @throws Exception if unable to compute a result
     */
    V call() throws Exception;
}

Runnable on the other hand is interface that declares run() method that is called when you create a Thread with the runnable and call start() on it. You can also directly call run() but that just executes the run() method is same thread.

public interface Runnable {
    /**
     * When an object implementing interface <code>Runnable</code> is used 
     * to create a thread, starting the thread causes the object's 
     * <code>run</code> method to be called in that separately executing 
     * thread. 
     * <p>
     * The general contract of the method <code>run</code> is that it may 
     * take any action whatsoever.
     *
     * @see     java.lang.Thread#run()
     */
    public abstract void run();
}

To summarize few notable Difference are

  1. A Runnable object does not return a result whereas a Callable object returns a result.
  2. A Runnable object cannot throw a checked exception wheras a Callable object can throw an exception.
  3. The Runnable interface has been around since Java 1.0 whereas Callable was only introduced in Java 1.5.

Few similarities include

  1. Instances of the classes that implement Runnable or Callable interfaces are potentially executed by another thread.
  2. Instance of both Callable and Runnable interfaces can be executed by ExecutorService via submit() method.
  3. Both are functional interfaces and can be used in Lambda expressions since Java8.

Methods in ExecutorService interface are

<T> Future<T> submit(Callable<T> task);
Future<?> submit(Runnable task);
<T> Future<T> submit(Runnable task, T result);

How to import JsonConvert in C# application?

After instaling the package you need to add the newtonsoft.json.dll into assemble path by runing the flowing command.

Before we can use our assembly, we have to add it to the global assembly cache (GAC). Open the Visual Studio 2008 Command Prompt again (for Vista/Windows7/etc. open it as Administrator). And execute the following command. gacutil /i d:\myMethodsForSSIS\myMethodsForSSIS\bin\Release\myMethodsForSSIS.dll

flow this link for more informATION http://microsoft-ssis.blogspot.com/2011/05/referencing-custom-assembly-inside.html

ReferenceError: fetch is not defined

You should add this import in your file:

import * as fetch from 'node-fetch';

And then, run this code to add the node-fetch:

yarn add node-fetch

Find the last time table was updated

If you want to see data updates you could use this technique with required permissions:

SELECT OBJECT_NAME(OBJECT_ID) AS DatabaseName, last_user_update,*
FROM sys.dm_db_index_usage_stats
WHERE database_id = DB_ID( 'DATABASE')
AND OBJECT_ID=OBJECT_ID('TABLE')

Show current assembly instruction in GDB

You can do

display/i $pc

and every time GDB stops, it will display the disassembly of the next instruction.

GDB-7.0 also supports set disassemble-next-line on, which will disassemble the entire next line, and give you more of the disassembly context.

How to make div fixed after you scroll to that div?

This is possible with CSS3. Just use position: sticky, as seen here.

position: -webkit-sticky; /* Safari & IE */
position: sticky;
top: 0;

Debug message "Resource interpreted as other but transferred with MIME type application/javascript"

An image with an empty "src" attribute generates this error under Windows-Chrome:

<img src="">

... whereas ...

<img>

... does not.

I arrived here because my ajax resultset was returning "src" data which was empty yet the img was still being inserted into the page.

Ternary operator in PowerShell

If you're just looking for a syntactically simple way to assign/return a string or numeric based on a boolean condition, you can use the multiplication operator like this:

"Condition is "+("true"*$condition)+("false"*!$condition)
(12.34*$condition)+(56.78*!$condition)

If you're only ever interested in the result when something is true, you can just omit the false part entirely (or vice versa), e.g. a simple scoring system:

$isTall = $true
$isDark = $false
$isHandsome = $true

$score = (2*$isTall)+(4*$isDark)+(10*$isHandsome)
"Score = $score"
# or
# "Score = $((2*$isTall)+(4*$isDark)+(10*$isHandsome))"

Note that the boolean value should not be the leading term in the multiplication, i.e. $condition*"true" etc. won't work.

Imported a csv-dataset to R but the values becomes factors

Both the data import function (here: read.csv()) as well as a global option offer you to say stringsAsFactors=FALSE which should fix this.

How to redirect to logon page when session State time out is completed in asp.net mvc

One way is that In case of Session Expire, in every action you have to check its session and if it is null then redirect to Login page.

But this is very hectic method To over come this you need to create your own ActionFilterAttribute which will do this, you just need to add this attribute in every action method.

Here is the Class which overrides ActionFilterAttribute.

public class SessionExpireFilterAttribute : ActionFilterAttribute
    {
        public override void OnActionExecuting(ActionExecutingContext filterContext)
        {
            HttpContext ctx = HttpContext.Current;

            // check if session is supported
            CurrentCustomer objCurrentCustomer = new CurrentCustomer();
            objCurrentCustomer = ((CurrentCustomer)SessionStore.GetSessionValue(SessionStore.Customer));
            if (objCurrentCustomer == null)
            {
                // check if a new session id was generated
                filterContext.Result = new RedirectResult("~/Users/Login");
                return;
            }

            base.OnActionExecuting(filterContext);
        }
    }

Then in action just add this attribute like so:

[SessionExpire]
public ActionResult Index()
{
     return Index();
}

This will do you work.

What is a JavaBean exactly?

Just a little background/update on the bean concept. Many other answers actually have the what but not so much why of them.

They were invented early on in Java as part of building GUIs. They followed patterns that were easy for tools to pull apart letting them create a properties panel so you could edit the attributes of the Bean. In general, the Bean properties represented a control on the screen (Think x,y,width,height,text,..)

You can also think of it as a strongly typed data structure.

Over time these became useful for lots of tools that used the same type of access (For example, Hibernate to persist data structures to the database)

As the tools evolved, they moved more towards annotations and away from pulling apart the setter/getter names. Now most systems don't require beans, they can take any plain old Java object with annotated properties to tell them how to manipulate them.

Now I see beans as annotated property balls--they are really only useful for the annotations they carry.

Beans themselves are not a healthy pattern. They destroy encapsulation by their nature since they expose all their properties to external manipulation and as they are used there is a tendency (by no means a requirement) to create code to manipulate the bean externally instead of creating code inside the bean (violates "don't ask an object for its values, ask an object to do something for you"). Using annotated POJOs with minimal getters and no setters is much more OO restoring encapsulation and with the possibility of immutability.

By the way, as all this stuff was happening someone extended the concept to something called Enterprise Java Beans. These are... different. and they are complicated enough that many people felt they didn't understand the entire Bean concept and stopped using the term. This is, I think, why you generally hear beans referred to as POJOs (since every Java object is a POJO this is technically OK, but when you hear someone say POJO they are most often thinking about something that follows the bean pattern)

The application has stopped unexpectedly: How to Debug?

Check whether your app has the needed permissions.I was also getting the same error and I checked the logcat debug log which showed this:

04-15 13:38:25.387: E/AndroidRuntime(694): java.lang.SecurityException: Permission Denial: starting Intent { act=android.intent.action.CALL dat=tel:555-555-5555 cmp=com.android.phone/.OutgoingCallBroadcaster } from ProcessRecord{44068640 694:rahulserver.test/10055} (pid=694, uid=10055) requires android.permission.CALL_PHONE

I then gave the needed permission in my android-manifest which worked for me.

Jmeter - Run .jmx file through command line and get the summary report in a excel

You can use this command,

jmeter -n -t /path to the script.jmx -l /path to save results with file name file.jtl

But if you really want to run a load test in a remote machine, you should be able to make it run eventhough you close the window. So we can use nohup to ignore the HUP (hangup) signal. So you can use this command as below.

nohup sh jmeter.sh -n -t /path to the script.jmx -l /path to save results with file name file.jtl &

Include headers when using SELECT INTO OUTFILE?

The easiest way is to hard code the columns yourself to better control the output file:

SELECT 'ColName1', 'ColName2', 'ColName3'
UNION ALL
SELECT ColName1, ColName2, ColName3
    FROM YourTable
    INTO OUTFILE '/path/outfile'

TSQL Pivot without aggregate function

SELECT
main.CustomerID,
f.Data AS FirstName,
m.Data AS MiddleName,
l.Data AS LastName,
d.Data AS Date
FROM table main
INNER JOIN table f on f.CustomerID = main.CustomerID
INNER JOIN table m on m.CustomerID = main.CustomerID
INNER JOIN table l on l.CustomerID = main.CustomerID
INNER JOIN table d on d.CustomerID = main.CustomerID
WHERE f.DBColumnName = 'FirstName' 
AND m.DBColumnName = 'MiddleName' 
AND l.DBColumnName = 'LastName' 
AND d.DBColumnName = 'Date' 

Edit: I have written this without an editor & have not run the SQL. I hope, you get the idea.

Calculate the execution time of a method

From personal experience, the System.Diagnostics.Stopwatch class can be used to measure the execution time of a method, however, BEWARE: It is not entirely accurate!

Consider the following example:

Stopwatch sw;

for(int index = 0; index < 10; index++)
{
    sw = Stopwatch.StartNew();
    DoSomething();
    Console.WriteLine(sw.ElapsedMilliseconds);
}

sw.Stop();

Example results

132ms
4ms
3ms
3ms
2ms
3ms
34ms
2ms
1ms
1ms

Now you're wondering; "well why did it take 132ms the first time, and significantly less the rest of the time?"

The answer is that Stopwatch does not compensate for "background noise" activity in .NET, such as JITing. Therefore the first time you run your method, .NET JIT's it first. The time it takes to do this is added to the time of the execution. Equally, other factors will also cause the execution time to vary.

What you should really be looking for absolute accuracy is Performance Profiling!

Take a look at the following:

RedGate ANTS Performance Profiler is a commercial product, but produces very accurate results. - Boost the performance of your applications with .NET profiling

Here is a StackOverflow article on profiling: - What Are Some Good .NET Profilers?

I have also written an article on Performance Profiling using Stopwatch that you may want to look at - Performance profiling in .NET

How to navigate to a section of a page

Use hypertext reference and the ID tag,

Target Text Title

Some paragraph text

Target Text

<h1><a href="#target">Target Text Title</a></h1>
<p id="target">Target Text</p>

Invalid attempt to read when no data is present

You have to call DataReader.Read to fetch the result:

SqlDataReader dr = cmd10.ExecuteReader();
if (dr.Read()) 
{
    // read data for first record here
}

DataReader.Read() returns a bool indicating if there are more blocks of data to read, so if you have more than 1 result, you can do:

while (dr.Read()) 
{
    // read data for each record here
}

How do I open an .exe from another C++ .exe?

Provide the full path of the file openfile.exe and remember not to put forward slash / in the path such as c:/users/username/etc.... instead of that use c:\\Users\\username\etc (for windows)

May be this will help you.

BLOB to String, SQL Server

It depends on how the data was initially put into the column. Try either of these as one should work:

SELECT CONVERT(NVarChar(40), BLOBTextToExtract)
FROM [NavisionSQL$Customer];

Or if it was just varchar...

SELECT CONVERT(VarChar(40), BLOBTextToExtract)
FROM [NavisionSQL$Customer];

I used this script to verify and test on SQL Server 2K8 R2:

DECLARE @blob VarBinary(MAX) = CONVERT(VarBinary(MAX), 'test');

-- show the binary representation
SELECT @blob;

-- this doesn't work
SELECT CONVERT(NVarChar(100), @blob);

-- but this does
SELECT CONVERT(VarChar(100), @blob);

Example JavaScript code to parse CSV data

Here's another solution. This uses:

  • a coarse global regular expression for splitting the CSV string (which includes surrounding quotes and trailing commas)
  • fine-grained regular expression for cleaning up the surrounding quotes and trailing commas
  • also, has type correction differentiating strings, numbers and boolean values

For the following input string:

"This is\, a value",Hello,4,-123,3.1415,'This is also\, possible',true

The code outputs:

[
  "This is, a value",
  "Hello",
  4,
  -123,
  3.1415,
  "This is also, possible",
  true
]

Here's my implementation of parseCSVLine() in a runnable code snippet:

_x000D_
_x000D_
function parseCSVLine(text) {
  return text.match( /\s*(\".*?\"|'.*?'|[^,]+)\s*(,|$)/g ).map( function (text) {
    let m;
    if (m = text.match(/^\s*\"(.*?)\"\s*,?$/)) return m[1]; // Double Quoted Text
    if (m = text.match(/^\s*'(.*?)'\s*,?$/)) return m[1]; // Single Quoted Text
    if (m = text.match(/^\s*(true|false)\s*,?$/)) return m[1] === "true"; // Boolean
    if (m = text.match(/^\s*((?:\+|\-)?\d+)\s*,?$/)) return parseInt(m[1]); // Integer Number
    if (m = text.match(/^\s*((?:\+|\-)?\d*\.\d*)\s*,?$/)) return parseFloat(m[1]); // Floating Number
    if (m = text.match(/^\s*(.*?)\s*,?$/)) return m[1]; // Unquoted Text
    return text;
  } );
}

let data = `"This is\, a value",Hello,4,-123,3.1415,'This is also\, possible',true`;
let obj = parseCSVLine(data);
console.log( JSON.stringify( obj, undefined, 2 ) );
_x000D_
_x000D_
_x000D_

Constants in Objective-C

If you want to call something like this NSString.newLine; from objective c, and you want it to be static constant, you can create something like this in swift:

public extension NSString {
    @objc public static let newLine = "\n"
}

And you have nice readable constant definition, and available from within a type of your choice while stile bounded to context of type.

Binding Combobox Using Dictionary as the Datasource

userListComboBox.DataSource = userCache.ToList();
userListComboBox.DisplayMember = "Key";

Change width of select tag in Twitter Bootstrap

You can use something like this

<div class="row">
     <div class="col-xs-2">
       <select id="info_type" class="form-control">
             <option>College</option>
             <option>Exam</option>
       </select>
     </div>
</div>

http://getbootstrap.com/css/#column-sizing

Convert double to BigDecimal and set BigDecimal Precision

BigDecimal b = new BigDecimal(c).setScale(2,BigDecimal.ROUND_HALF_UP);

Android Color Picker

We have just uploaded AmbilWarna color picker to Maven:

https://github.com/yukuku/ambilwarna

It can be used either as a dialog or as a Preference entry.

enter image description here

Java how to sort a Linked List?

Elegant solution since JAVA 8:

LinkedList<String>list = new LinkedList<String>();
list.add("abc");
list.add("Bcd");
list.add("aAb");

list.sort(String::compareToIgnoreCase);

Another option would be using lambda expressions:

list.sort((o1, o2) -> o1.compareToIgnoreCase(o2));

Breaking to a new line with inline-block?

Set the items into display: inline and use :after:

.text span { display: inline }
.break-after:after { content: '\A'; white-space:pre; }

and add the class into your html spans:

<span class="medium break-after">We</span>

How to remove backslash on json_encode() function?

Since PHP 5.4 there are constants which can be used by json_encode() to format the json reponse how you want.

To remove backslashes use: JSON_UNESCAPED_SLASHES. Like so:

json_encode($response, JSON_UNESCAPED_SLASHES);

View the PHP documentation for more constants and further information:

http://php.net/manual/en/function.json-encode.php

List of JSON constants:

http://php.net/manual/en/json.constants.php

Uncaught TypeError: Cannot read property 'split' of undefined

og_date = "2012-10-01";
console.log(og_date); // => "2012-10-01"

console.log(og_date.split('-')); // => [ '2012', '10', '01' ]

og_date.value would only work if the date were stored as a property on the og_date object. Such as: var og_date = {}; og_date.value="2012-10-01"; In that case, your original console.log would work.

Create a Cumulative Sum Column in MySQL

MySQL 8.0/MariaDB supports windowed SUM(col) OVER():

SELECT *, SUM(cnt) OVER(ORDER BY id) AS cumulative_sum
FROM tab;

Output:

+-----------------------------+
¦ id  ¦ cnt  ¦ cumulative_sum ¦
+-----+------+----------------¦
¦  1  ¦ 100  ¦            100 ¦
¦  2  ¦  50  ¦            150 ¦
¦  3  ¦  10  ¦            160 ¦
+-----------------------------+

db<>fiddle

Exception in thread "main" java.lang.UnsupportedClassVersionError: a (Unsupported major.minor version 51.0)

Assuming you are using Eclipse, on a MAC you can:

  1. Launch Eclipse.app
  2. Choose Eclipse -> Preferences
  3. Choose Java -> Installed JREs
  4. Click the Add... button
  5. Choose MacOS X VM as the JRE type. Press Next.
  6. In the "JRE Home:" field, type /Library/Java/JavaVirtualMachines/1.7.0.jdk/Contents/Home
  7. You should see the system libraries in the list titled "JRE system libraries:"
  8. Give the JRE a name. The recommended name is JDK 1.7. Click Finish.
  9. Check the checkbox next to the JRE entry you just created. This will cause Eclipse to use it as the default JRE for all new Java projects. Click OK.
  10. Now, create a new project. For this verification, from the menu, select File -> New -> Java Project.
  11. In the dialog that appears, enter a new name for your project. For this verification, type Test17Project
  12. In the JRE section of the dialog, select Use default JRE (currently JDK 1.7)
  13. Click Finish.

Hope this helps

Load an image from a url into a PictureBox

yourPictureBox.ImageLocation = "http://www.gravatar.com/avatar/6810d91caff032b202c50701dd3af745?d=identicon&r=PG"