Programs & Examples On #Geohashing

Paging with LINQ for objects

There are two main options:

.NET >= 4.0 Dynamic LINQ:

  1. Add using System.Linq.Dynamic; at the top.
  2. Use: var people = people.AsQueryable().OrderBy("Make ASC, Year DESC").ToList();

You can also get it by NuGet.

.NET < 4.0 Extension Methods:

private static readonly Hashtable accessors = new Hashtable();

private static readonly Hashtable callSites = new Hashtable();

private static CallSite<Func<CallSite, object, object>> GetCallSiteLocked(string name) {
    var callSite = (CallSite<Func<CallSite, object, object>>)callSites[name];
    if(callSite == null)
    {
        callSites[name] = callSite = CallSite<Func<CallSite, object, object>>.Create(
                    Binder.GetMember(CSharpBinderFlags.None, name, typeof(AccessorCache),
                new CSharpArgumentInfo[] { CSharpArgumentInfo.Create(CSharpArgumentInfoFlags.None, null) }));
    }
    return callSite;
}

internal static Func<dynamic,object> GetAccessor(string name)
{
    Func<dynamic, object> accessor = (Func<dynamic, object>)accessors[name];
    if (accessor == null)
    {
        lock (accessors )
        {
            accessor = (Func<dynamic, object>)accessors[name];
            if (accessor == null)
            {
                if(name.IndexOf('.') >= 0) {
                    string[] props = name.Split('.');
                    CallSite<Func<CallSite, object, object>>[] arr = Array.ConvertAll(props, GetCallSiteLocked);
                    accessor = target =>
                    {
                        object val = (object)target;
                        for (int i = 0; i < arr.Length; i++)
                        {
                            var cs = arr[i];
                            val = cs.Target(cs, val);
                        }
                        return val;
                    };
                } else {
                    var callSite = GetCallSiteLocked(name);
                    accessor = target =>
                    {
                        return callSite.Target(callSite, (object)target);
                    };
                }
                accessors[name] = accessor;
            }
        }
    }
    return accessor;
}
public static IOrderedEnumerable<dynamic> OrderBy(this IEnumerable<dynamic> source, string property)
{
    return Enumerable.OrderBy<dynamic, object>(source, AccessorCache.GetAccessor(property), Comparer<object>.Default);
}
public static IOrderedEnumerable<dynamic> OrderByDescending(this IEnumerable<dynamic> source, string property)
{
    return Enumerable.OrderByDescending<dynamic, object>(source, AccessorCache.GetAccessor(property), Comparer<object>.Default);
}
public static IOrderedEnumerable<dynamic> ThenBy(this IOrderedEnumerable<dynamic> source, string property)
{
    return Enumerable.ThenBy<dynamic, object>(source, AccessorCache.GetAccessor(property), Comparer<object>.Default);
}
public static IOrderedEnumerable<dynamic> ThenByDescending(this IOrderedEnumerable<dynamic> source, string property)
{
    return Enumerable.ThenByDescending<dynamic, object>(source, AccessorCache.GetAccessor(property), Comparer<object>.Default);
}

SQL Server Insert Example

To insert a single row of data:

INSERT INTO USERS
VALUES (1, 'Mike', 'Jones');

To do an insert on specific columns (as opposed to all of them) you must specify the columns you want to update.

INSERT INTO USERS (FIRST_NAME, LAST_NAME)
VALUES ('Stephen', 'Jiang');

To insert multiple rows of data in SQL Server 2008 or later:

INSERT INTO USERS VALUES
(2, 'Michael', 'Blythe'),
(3, 'Linda', 'Mitchell'),
(4, 'Jillian', 'Carson'),
(5, 'Garrett', 'Vargas');

To insert multiple rows of data in earlier versions of SQL Server, use "UNION ALL" like so:

INSERT INTO USERS (FIRST_NAME, LAST_NAME)
SELECT 'James', 'Bond' UNION ALL
SELECT 'Miss', 'Moneypenny' UNION ALL
SELECT 'Raoul', 'Silva'

Note, the "INTO" keyword is optional in INSERT queries. Source and more advanced querying can be found here.

Unfortunately MyApp has stopped. How can I solve this?

Just check the error in log cat.

You get the log cat option from in eclipse:

window->show view->others->Android->Logcat

Log cat contains error.

Other wise you can also check the error by executing an application in debug mode. Firstly set breakpoint after that by doing:

right click on project->debug as->Android application

appending list but error 'NoneType' object has no attribute 'append'

list is mutable

Change

last_list=last_list.append(p.last_name)

to

last_list.append(p.last_name)

will work

Does hosts file exist on the iPhone? How to change it?

Another option here is to have your iPhone connect via a proxy. Here's an example of how to do it with Fiddler (it's very easy):

http://conceptdev.blogspot.com/2009/01/monitoring-iphone-web-traffic-with.html

In that case any dns lookups your iPhone does will use the hosts file of the machine Fiddler is running on. Note, though, that you must use a name that will be resolved via DNS. example.local, for instance, will not work. example.xyz or example.dev will.

How are booleans formatted in Strings in Python?

You may also use the Formatter class of string

print "{0} {1}".format(True, False);
print "{0:} {1:}".format(True, False);
print "{0:d} {1:d}".format(True, False);
print "{0:f} {1:f}".format(True, False);
print "{0:e} {1:e}".format(True, False);

These are the results

True False
True False
1 0
1.000000 0.000000
1.000000e+00 0.000000e+00

Some of the %-format type specifiers (%r, %i) are not available. For details see the Format Specification Mini-Language

Access denied for user 'root'@'localhost' with PHPMyAdmin

Here are few steps that must be followed carefully

  1. First of all make sure that the WAMP server is running if it is not running, start the server.
  2. Enter the URL http://localhost/phpmyadmin/setup in address bar of your browser.
  3. Create a folder named config inside C:\wamp\apps\phpmyadmin, the folder inside apps may have different name like phpmyadmin3.2.0.1

  4. Return to your browser in phpmyadmin setup tab, and click New server.New server

  5. Change the authentication type to ‘cookie’ and leave the username and password field empty but if you change the authentication type to ‘config’ enter the password for username root.

  6. Click save save

  7. Again click save in configuration file option.
  8. Now navigate to the config folder. Inside the folder there will be a file named config.inc.php. Copy the file and paste it out of the folder (if the file with same name is already there then override it) and finally delete the folder.
  9. Now you are done. Try to connect the mysql server again and this time you won’t get any error. --credits Bibek Subedi

typedef struct vs struct definitions

The common idiom is using both:

typedef struct S { 
    int x; 
} S;

They are different definitions. To make the discussion clearer I will split the sentence:

struct S { 
    int x; 
};

typedef struct S S;

In the first line you are defining the identifier S within the struct name space (not in the C++ sense). You can use it and define variables or function arguments of the newly defined type by defining the type of the argument as struct S:

void f( struct S argument ); // struct is required here

The second line adds a type alias S in the global name space and thus allows you to just write:

void f( S argument ); // struct keyword no longer needed

Note that since both identifier name spaces are different, defining S both in the structs and global spaces is not an error, as it is not redefining the same identifier, but rather creating a different identifier in a different place.

To make the difference clearer:

typedef struct S { 
    int x; 
} T;

void S() { } // correct

//void T() {} // error: symbol T already defined as an alias to 'struct S'

You can define a function with the same name of the struct as the identifiers are kept in different spaces, but you cannot define a function with the same name as a typedef as those identifiers collide.

In C++, it is slightly different as the rules to locate a symbol have changed subtly. C++ still keeps the two different identifier spaces, but unlike in C, when you only define the symbol within the class identifier space, you are not required to provide the struct/class keyword:

 // C++
struct S { 
    int x; 
}; // S defined as a class

void f( S a ); // correct: struct is optional

What changes are the search rules, not where the identifiers are defined. The compiler will search the global identifier table and after S has not been found it will search for S within the class identifiers.

The code presented before behaves in the same way:

typedef struct S { 
    int x; 
} T;

void S() {} // correct [*]

//void T() {} // error: symbol T already defined as an alias to 'struct S'

After the definition of the S function in the second line, the struct S cannot be resolved automatically by the compiler, and to create an object or define an argument of that type you must fall back to including the struct keyword:

// previous code here...
int main() {
    S(); 
    struct S s;
}

What is the difference between explicit and implicit cursors in Oracle?

As stated in other answers, implicit cursors are easier to use and less error-prone.

And Implicit vs. Explicit Cursors in Oracle PL/SQL shows that implicit cursors are up to two times faster than explicit ones too.

It's strange that no one had yet mentioned Implicit FOR LOOP Cursor:

begin
  for cur in (
    select t.id from parent_trx pt inner join trx t on pt.nested_id = t.id
    where t.started_at > sysdate - 31 and t.finished_at is null and t.extended_code is null
  )
  loop
    update trx set finished_at=sysdate, extended_code = -1 where id = cur.id;
    update parent_trx set result_code = -1 where nested_id = cur.id;
  end loop cur;
end;

Another example on SO: PL/SQL FOR LOOP IMPLICIT CURSOR.

It's way more shorter than explicit form.

This also provides a nice workaround for updating multiple tables from CTE.

Limit number of characters allowed in form input text field

<input type="number" id="xxx" name="xxx" oninput="maxLengthCheck(this)" maxlength="10">

function maxLengthCheck(object) {
  if (object.value.length > object.maxLength)
  object.value = object.value.slice(0, object.maxLength)
}

NVIDIA NVML Driver/library version mismatch

The top-2 answers can't solve my problem. I found a solution at the Nvidia official forum solved my problem. The below error info may cause by installing two different versions of the driver by different approaches. For example, install Nvidia driver by the apt and the official installer.

Failed to initialize NVML: Driver/library version mismatch

To solve this problem, only need to execute one of the following two commands.

sudo apt-get --purge remove "*nvidia*"
sudo /usr/bin/nvidia-uninstall

WPF Add a Border to a TextBlock

No, you need to wrap your TextBlock in a Border. Example:

<Border BorderThickness="1" BorderBrush="Black">
    <TextBlock ... />
</Border>

Of course, you can set these properties (BorderThickness, BorderBrush) through styles as well:

<Style x:Key="notCalledBorder" TargetType="{x:Type Border}">
    <Setter Property="BorderThickness" Value="1" />
    <Setter Property="BorderBrush" Value="Black" />
</Style>

<Border Style="{StaticResource notCalledBorder}">
    <TextBlock ... />
</Border>

How to convert comma-separated String to List?

There is no built-in method for this but you can simply use split() method in this.

String commaSeparated = "item1 , item2 , item3";
ArrayList<String> items = 
new  ArrayList<String>(Arrays.asList(commaSeparated.split(",")));

Checking something isEmpty in Javascript?

What about doing like this.

JSON.stringify({}) === "{}"

How does JavaScript .prototype work?

another scheme showing __proto__, prototype and constructor relations: enter image description here

Order a List (C#) by many fields?

Use ThenBy:

var orderedCustomers = Customer.OrderBy(c => c.LastName).ThenBy(c => c.FirstName)

See MSDN: http://msdn.microsoft.com/en-us/library/bb549422.aspx

How to convert between bytes and strings in Python 3?

In python3, there is a bytes() method that is in the same format as encode().

str1 = b'hello world'
str2 = bytes("hello world", encoding="UTF-8")
print(str1 == str2) # Returns True

I didn't read anything about this in the docs, but perhaps I wasn't looking in the right place. This way you can explicitly turn strings into byte streams and have it more readable than using encode and decode, and without having to prefex b in front of quotes.

Representing EOF in C code?

The value of EOF can't be confused with any real character.

If a= getchar(), then we must declare a big enough to hold any value that getchar() returns. We can't use char since a must be big enough to hold EOF in addition to characters.

How to get resources directory path programmatically

Just use com.google.common.io.Resources class. Example:

 URL url = Resources.getResource("file name")

After that you have methods like: .getContent(), .getFile(), .getPath() etc

JavaScript/jQuery to download file via POST with JSON data

Not entirely an answer to the original post, but a quick and dirty solution for posting a json-object to the server and dynamically generating a download.

Client side jQuery:

var download = function(resource, payload) {
     $("#downloadFormPoster").remove();
     $("<div id='downloadFormPoster' style='display: none;'><iframe name='downloadFormPosterIframe'></iframe></div>").appendTo('body');
     $("<form action='" + resource + "' target='downloadFormPosterIframe' method='post'>" +
      "<input type='hidden' name='jsonstring' value='" + JSON.stringify(payload) + "'/>" +
      "</form>")
      .appendTo("#downloadFormPoster")
      .submit();
}

..and then decoding the json-string at the serverside and setting headers for download (PHP example):

$request = json_decode($_POST['jsonstring']), true);
header('Content-Type: application/csv');
header('Content-Disposition: attachment; filename=export.csv');
header('Pragma: no-cache');

How to format column to number format in Excel sheet?

Sorry to bump an old question but the answer is to count the character length of the cell and not its value.

CellCount = Cells(Row, 10).Value
If Len(CellCount) <= "13" Then
'do something
End If

hope that helps. Cheers

What is the best (and safest) way to merge a Git branch into master?

As the title says "Best way", I think it's a good idea to consider the patience merge strategy.

From: https://git-scm.com/docs/merge-strategies

With this option, 'merge-recursive' spends a little extra time to avoid mismerges that sometimes occur due to unimportant matching lines (e.g., braces from distinct functions). Use this when the branches to be merged have diverged wildly. See also git-diff[1] --patience.

Usage:

git fetch
git merge -s recursive -X patience origin/master

Git Alias

I use always an alias for this, e.g. run once:

 git config --global alias.pmerge 'merge -s recursive -X patience'

Now you could do:

git fetch
git pmerge origin/master

add an onclick event to a div

Everythings works well. You can't use divtag.onclick, becease "onclick" attribute doesn't exist. You need first create this attribute by using .setAttribute(). Look on this http://reference.sitepoint.com/javascript/Element/setAttribute . You should read documentations first before you start giving "-".

How to install pip in CentOS 7?

curl https://bootstrap.pypa.io/get-pip.py | python3.4

Or if you don't have curl for some reason:

wget https://bootstrap.pypa.io/get-pip.py
python3.4 get-pip.py

After this you should be able to run

$ pip3

"No resource identifier found for attribute 'showAsAction' in package 'android'"

all above fix may not work in android studio .if you are using ANDROID STUDIO...... use this fix

add

xmlns:compat="http://schemas.android.com/tools"

in menu tag instead of

xmlns:compat="http://schemas.android.com/apk/res-auto"

in menu tag.

How Do I Uninstall Yarn

In case you installed yarn globally like this

$ sudo npm install -g yarn

Just run this in terminal

$ sudo npm uninstall -g yarn

Tested now on my local machine running Ubuntu. Works perfect!

Default value in Go's method

NO,but there are some other options to implement default value. There are some good blog posts on the subject, but here are some specific examples.


**Option 1:** The caller chooses to use default values
// Both parameters are optional, use empty string for default value
func Concat1(a string, b int) string {
  if a == "" {
    a = "default-a"
  }
  if b == 0 {
    b = 5
  }

  return fmt.Sprintf("%s%d", a, b)
}

**Option 2:** A single optional parameter at the end
// a is required, b is optional.
// Only the first value in b_optional will be used.
func Concat2(a string, b_optional ...int) string {
  b := 5
  if len(b_optional) > 0 {
    b = b_optional[0]
  }

  return fmt.Sprintf("%s%d", a, b)
}

**Option 3:** A config struct
// A declarative default value syntax
// Empty values will be replaced with defaults
type Parameters struct {
  A string `default:"default-a"` // this only works with strings
  B string // default is 5
}

func Concat3(prm Parameters) string {
  typ := reflect.TypeOf(prm)

  if prm.A == "" {
    f, _ := typ.FieldByName("A")
    prm.A = f.Tag.Get("default")
  }

  if prm.B == 0 {
    prm.B = 5
  }

  return fmt.Sprintf("%s%d", prm.A, prm.B)
}

**Option 4:** Full variadic argument parsing (javascript style)
func Concat4(args ...interface{}) string {
  a := "default-a"
  b := 5

  for _, arg := range args {
    switch t := arg.(type) {
      case string:
        a = t
      case int:
        b = t
      default:
        panic("Unknown argument")
    }
  }

  return fmt.Sprintf("%s%d", a, b)
}

JavaScript: Passing parameters to a callback function

Wrap the 'child' function(s) being passed as/with arguments within function wrappers to prevent them being evaluated when the 'parent' function is called.

function outcome(){
    return false;
}

function process(callbackSuccess, callbackFailure){
    if ( outcome() )
        callbackSuccess();
    else
        callbackFailure();
}

process(function(){alert("OKAY");},function(){alert("OOPS");})

Parsing XML in Python using ElementTree example

So I have ElementTree 1.2.6 on my box now, and ran the following code against the XML chunk you posted:

import elementtree.ElementTree as ET

tree = ET.parse("test.xml")
doc = tree.getroot()
thingy = doc.find('timeSeries')

print thingy.attrib

and got the following back:

{'name': 'NWIS Time Series Instantaneous Values'}

It appears to have found the timeSeries element without needing to use numerical indices.

What would be useful now is knowing what you mean when you say "it doesn't work." Since it works for me given the same input, it is unlikely that ElementTree is broken in some obvious way. Update your question with any error messages, backtraces, or anything you can provide to help us help you.

Call php function from JavaScript

I recently published a jQuery plugin which allows you to make PHP function calls in various ways: https://github.com/Xaxis/jquery.php

Simple example usage:

// Both .end() and .data() return data to variables
var strLenA = P.strlen('some string').end();
var strLenB = P.strlen('another string').end();
var totalStrLen = strLenA + strLenB;
console.log( totalStrLen ); // 25

// .data Returns data in an array
var data1 = P.crypt("Some Crypt String").data();
console.log( data1 ); // ["$1$Tk1b01rk$shTKSqDslatUSRV3WdlnI/"]

Implement an input with a mask

You can achieve this also by using JavaScripts's native method. Its pretty simple and doesn't require any extra library to import.

<input type="text" name="date" placeholder="yyyy-mm-dd" onkeyup="
  var date = this.value;
  if (date.match(/^\d{4}$/) !== null) {
     this.value = date + '-';
  } else if (date.match(/^\d{4}\-\d{2}$/) !== null) {
     this.value = date + '-';
  }" maxlength="10">

window.onunload is not working properly in Chrome browser. Can any one help me?

The onunload event won't fire if the onload event did not fire. Unfortunately the onload event waits for all binary content (e.g. images) to load, and inline scripts run before the onload event fires. DOMContentLoaded fires when the page is visible, before onload does. And it is now standard in HTML 5, and you can test for browser support but note this requires the <!DOCTYPE html> (at least in Chrome). However, I can not find a corresponding event for unloading the DOM. And such a hypothetical event might not work because some browsers may keep the DOM around to perform the "restore tab" feature.

The only potential solution I found so far is the Page Visibility API, which appears to require the <!DOCTYPE html>.

How to configure logging to syslog in Python?

Here's the yaml dictConfig way recommended for 3.2 & later.

In log cfg.yml:

version: 1
disable_existing_loggers: true

formatters:
    default:
        format: "[%(process)d] %(name)s(%(funcName)s:%(lineno)s) - %(levelname)s: %(message)s"

handlers:
    syslog:
        class: logging.handlers.SysLogHandler
        level: DEBUG
        formatter: default
        address: /dev/log
        facility: local0

    rotating_file:
        class: logging.handlers.RotatingFileHandler
        level: DEBUG
        formatter: default
        filename: rotating.log
        maxBytes: 10485760 # 10MB
        backupCount: 20
        encoding: utf8

root:
    level: DEBUG
    handlers: [syslog, rotating_file]
    propogate: yes

loggers:
    main:
        level: DEBUG
        handlers: [syslog, rotating_file]
        propogate: yes

Load the config using:

log_config = yaml.safe_load(open('cfg.yml'))
logging.config.dictConfig(log_config)

Configured both syslog & a direct file. Note that the /dev/log is OS specific.

Is there a unique Android device ID?

Google Instance ID

Released at I/O 2015; on Android requires play services 7.5.

https://developers.google.com/instance-id/
https://developers.google.com/instance-id/guides/android-implementation

InstanceID iid = InstanceID.getInstance( context );   // Google docs are wrong - this requires context
String id = iid.getId();  // blocking call

It seems that Google intends for this ID to be used to identify installations across Android, Chrome, and iOS.

It identifies an installation rather then a device, but then again, ANDROID_ID (which is the accepted answer) now no longer identifies devices either. With the ARC runtime a new ANDROID_ID is generated for every installation (details here), just like this new instance ID. Also, I think that identifying installations (not devices) is what most of us are actually looking for.

The advantages of instance ID

It appears to me that Google intends for it to be used for this purpose (identifying your installations), it is cross-platform, and can be used for a number of other purposes (see the links above).

If you use GCM, then you will eventually need to use this instance ID because you need it in order to get the GCM token (which replaces the old GCM registration ID).

The disadvantages/issues

In the current implementation (GPS 7.5) the instance ID is retrieved from a server when your app requests it. This means that the call above is a blocking call - in my unscientific testing it takes 1-3 seconds if the device is online, and 0.5 - 1.0 seconds if off-line (presumably this is how long it waits before giving up and generating a random ID). This was tested in North America on Nexus 5 with Android 5.1.1 and GPS 7.5.

If you use the ID for the purposes they intend - eg. app authentication, app identification, GCM - I think this 1-3 seconds could be a nuisance (depending on your app, of course).

Python: For each list element apply a function across the list

If I'm correct in thinking that you want to find the minimum value of a function for all possible pairs of 2 elements from a list...

l = [1,2,3,4,5]

def f(i,j):
   return i+j 

# Prints min value of f(i,j) along with i and j
print min( (f(i,j),i,j) for i in l for j in l)

How do I get the current username in Windows PowerShell?

I thought it would be valuable to summarize and compare the given answers.

If you want to access the environment variable:

(easier/shorter/memorable option)

  • [Environment]::UserName -- @ThomasBratt
  • $env:username -- @Eoin
  • whoami -- @galaktor

If you want to access the Windows access token:

(more dependable option)

  • [System.Security.Principal.WindowsIdentity]::GetCurrent().Name -- @MarkSeemann

If you want the name of the logged in user

(rather than the name of the user running the PowerShell instance)

  • $(Get-WMIObject -class Win32_ComputerSystem | select username).username -- @TwonOfAn on this other forum

Comparison

@Kevin Panko's comment on @Mark Seemann's answer deals with choosing one of the categories over the other:

[The Windows access token approach] is the most secure answer, because $env:USERNAME can be altered by the user, but this will not be fooled by doing that.

In short, the environment variable option is more succinct, and the Windows access token option is more dependable.

I've had to use @Mark Seemann's Windows access token approach in a PowerShell script that I was running from a C# application with impersonation.

The C# application is run with my user account, and it runs the PowerShell script as a service account. Because of a limitation of the way I'm running the PowerShell script from C#, the PowerShell instance uses my user account's environment variables, even though it is run as the service account user.

In this setup, the environment variable options return my account name, and the Windows access token option returns the service account name (which is what I wanted), and the logged in user option returns my account name.


Testing

Also, if you want to compare the options yourself, here is a script you can use to run a script as another user. You need to use the Get-Credential cmdlet to get a credential object, and then run this script with the script to run as another user as argument 1, and the credential object as argument 2.

Usage:

$cred = Get-Credential UserTo.RunAs
Run-AsUser.ps1 "whoami; pause" $cred
Run-AsUser.ps1 "[System.Security.Principal.WindowsIdentity]::GetCurrent().Name; pause" $cred

Contents of Run-AsUser.ps1 script:

param(
  [Parameter(Mandatory=$true)]
  [string]$script,
  [Parameter(Mandatory=$true)]
  [System.Management.Automation.PsCredential]$cred
)

Start-Process -Credential $cred -FilePath 'powershell.exe' -ArgumentList 'noprofile','-Command',"$script"

How to output to the console and file?

Here's a small improvement that to @UltraInstinct's Tee class, modified to be a context manager and also captures any exceptions.

import traceback
import sys

# Context manager that copies stdout and any exceptions to a log file
class Tee(object):
    def __init__(self, filename):
        self.file = open(filename, 'w')
        self.stdout = sys.stdout

    def __enter__(self):
        sys.stdout = self

    def __exit__(self, exc_type, exc_value, tb):
        sys.stdout = self.stdout
        if exc_type is not None:
            self.file.write(traceback.format_exc())
        self.file.close()

    def write(self, data):
        self.file.write(data)
        self.stdout.write(data)

    def flush(self):
        self.file.flush()
        self.stdout.flush()

To use the context manager:

print("Print")
with Tee('test.txt'):
    print("Print+Write")
    raise Exception("Test")
print("Print")

passing JSON data to a Spring MVC controller

  1. Html

    $('#save').click(function(event) {        
        var jenis = $('#jenis').val();
        var model = $('#model').val();
        var harga = $('#harga').val();
        var json = { "jenis" : jenis, "model" : model, "harga": harga};
        $.ajax({
            url: 'phone/save',
            data: JSON.stringify(json),
            type: "POST",           
            beforeSend: function(xhr) {
                xhr.setRequestHeader("Accept", "application/json");
                xhr.setRequestHeader("Content-Type", "application/json");
            },
            success: function(data){ 
                alert(data);
            }
        });
    
        event.preventDefault();
    });
    
    1. Controller

      @Controller
      @RequestMapping(value="/phone")
      public class phoneController {
      
          phoneDao pd=new phoneDao();
      
          @RequestMapping(value="/save",method=RequestMethod.POST)
          public @ResponseBody
          int save(@RequestBody Smartphones phone)
          {
              return pd.save(phone);
          }
      
    2. Dao

      public Integer save(Smartphones i) {
          int id = 0;
          Session session=HibernateUtil.getSessionFactory().openSession();
          Transaction trans=session.beginTransaction();
          try {
              session.save(i);   
              id=i.getId();
              trans.commit();
          }
          catch(HibernateException he){}
          return id;
      }
      

SQL Server: Invalid Column Name

Whenever this happens to me, I press Ctrl+Shift+R which refreshes intellisense, close the query window (save if necessary), then start a new session which usually works quite well.

Length of string in bash

Using your example provided

#KISS (Keep it simple stupid)
size=${#myvar}
echo $size

How to compare two strings are equal in value, what is the best method?

string1.equals(string2) is the way.

It returns true if string1 is equals to string2 in value. Else, it will return false.

equals reference

Is there a math nCr function in python?

The following program calculates nCr in an efficient manner (compared to calculating factorials etc.)

import operator as op
from functools import reduce

def ncr(n, r):
    r = min(r, n-r)
    numer = reduce(op.mul, range(n, n-r, -1), 1)
    denom = reduce(op.mul, range(1, r+1), 1)
    return numer // denom  # or / in Python 2

As of Python 3.8, binomial coefficients are available in the standard library as math.comb:

>>> from math import comb
>>> comb(10,3)
120

How do I delete from multiple tables using INNER JOIN in SQL server

As Aaron has already pointed out, you can set delete behaviour to CASCADE and that will delete children records when a parent record is deleted. Unless you want some sort of other magic to happen (in which case points 2, 3 of Aaron's reply would be useful), I don't see why would you need to delete with inner joins.

What is a lambda expression in C++11?

Answers

Q: What is a lambda expression in C++11?

A: Under the hood, it is the object of an autogenerated class with overloading operator() const. Such object is called closure and created by compiler. This 'closure' concept is near with the bind concept from C++11. But lambdas typically generate better code. And calls through closures allow full inlining.

Q: When would I use one?

A: To define "simple and small logic" and ask compiler perform generation from previous question. You give a compiler some expressions which you want to be inside operator(). All other stuff compiler will generate to you.

Q: What class of problem do they solve that wasn't possible prior to their introduction?

A: It is some kind of syntax sugar like operators overloading instead of functions for custom add, subrtact operations...But it save more lines of unneeded code to wrap 1-3 lines of real logic to some classes, and etc.! Some engineers think that if the number of lines is smaller then there is a less chance to make errors in it (I'm also think so)

Example of usage

auto x = [=](int arg1){printf("%i", arg1); };
void(*f)(int) = x;
f(1);
x(1);

Extras about lambdas, not covered by question. Ignore this section if you're not interest

1. Captured values. What you can to capture

1.1. You can reference to a variable with static storage duration in lambdas. They all are captured.

1.2. You can use lambda for capture values "by value". In such case captured vars will be copied to the function object (closure).

[captureVar1,captureVar2](int arg1){}

1.3. You can capture be reference. & -- in this context mean reference, not pointers.

   [&captureVar1,&captureVar2](int arg1){}

1.4. It exists notation to capture all non-static vars by value, or by reference

  [=](int arg1){} // capture all not-static vars by value

  [&](int arg1){} // capture all not-static vars by reference

1.5. It exists notation to capture all non-static vars by value, or by reference and specify smth. more. Examples: Capture all not-static vars by value, but by reference capture Param2

[=,&Param2](int arg1){} 

Capture all not-static vars by reference, but by value capture Param2

[&,Param2](int arg1){} 

2. Return type deduction

2.1. Lambda return type can be deduced if lambda is one expression. Or you can explicitly specify it.

[=](int arg1)->trailing_return_type{return trailing_return_type();}

If lambda has more then one expression, then return type must be specified via trailing return type. Also, similar syntax can be applied to auto functions and member-functions

3. Captured values. What you can not capture

3.1. You can capture only local vars, not member variable of the object.

4. ?onversions

4.1 !! Lambda is not a function pointer and it is not an anonymous function, but capture-less lambdas can be implicitly converted to a function pointer.

p.s.

  1. More about lambda grammar information can be found in Working draft for Programming Language C++ #337, 2012-01-16, 5.1.2. Lambda Expressions, p.88

  2. In C++14 the extra feature which has named as "init capture" have been added. It allow to perform arbitarily declaration of closure data members:

    auto toFloat = [](int value) { return float(value);};
    auto interpolate = [min = toFloat(0), max = toFloat(255)](int value)->float { return (value - min) / (max - min);};
    

How can I set a dynamic model name in AngularJS?

You can use something like this scopeValue[field], but if your field is in another object you will need another solution.

To solve all kind of situations, you can use this directive:

this.app.directive('dynamicModel', ['$compile', '$parse', function ($compile, $parse) {
    return {
        restrict: 'A',
        terminal: true,
        priority: 100000,
        link: function (scope, elem) {
            var name = $parse(elem.attr('dynamic-model'))(scope);
            elem.removeAttr('dynamic-model');
            elem.attr('ng-model', name);
            $compile(elem)(scope);
        }
    };
}]);

Html example:

<input dynamic-model="'scopeValue.' + field" type="text">

Auto insert date and time in form input field?

Im not do not know all of the technical language but I could not find the answer anywhere so I came up with this and it worked... Good Luck!

$time = date("Y/m/d h:i:s");

$sql = "INSERT INTO *yourtablenamehere* ('dt')  VALUES ('$time')";

How to check if a specified key exists in a given S3 bucket using Java

Use ListObjectsRequest setting Prefix as your key.

.NET code:

 public bool Exists(string key)
    {

        using (Amazon.S3.AmazonS3Client client = (Amazon.S3.AmazonS3Client)Amazon.AWSClientFactory.CreateAmazonS3Client(m_accessKey, m_accessSecret))
        {
            ListObjectsRequest request = new ListObjectsRequest();
            request.BucketName = m_bucketName;
            request.Prefix = key;
            using (ListObjectsResponse response = client.ListObjects(request))
            {

                foreach (S3Object o in response.S3Objects)
                {
                    if( o.Key == key )
                        return true;
                }
                return false;
            }
        }
    }.

Global javascript variable inside document.ready

You can define the variable inside the document ready function without var to make it a global variable. In javascript any variable declared without var automatically becomes a global variable

$(document).ready(function() {
    intro =  "something";
});

although you cant use the variable immediately, but it would be accessible to other functions

Hiding table data using <div style="display:none">

Unfortuantely, as div elements can't be direct descendants of table elements, the way I know to do this is to apply the CSS rules you want to each tr element that you want to apply it to.

<table>
<tr><th>Test Table</th><tr>
<tr><td>123456789</td><tr>
<tr style="display: none; other-property: value;"><td>123456789</td><tr>
<tr style="display: none; other-property: value;"><td>123456789</td><tr>
<tr><td>123456789</td><tr>
<tr><td>123456789</td><tr>
</table>

If you have more than one CSS rule to apply to the rows in question, give the applicable rows a class instead and offload the rules to external CSS.

<table>
<tr><th>Test Table</th><tr>
<tr><td>123456789</td><tr>
<tr class="something"><td>123456789</td><tr>
<tr class="something"><td>123456789</td><tr>
<tr><td>123456789</td><tr>
<tr><td>123456789</td><tr>
</table>

How can I avoid getting this MySQL error Incorrect column specifier for column COLUMN NAME?

The auto_increment property only works for numeric columns (integer and floating point), not char columns:

CREATE TABLE discussion_topics (
    topic_id INT NOT NULL AUTO_INCREMENT,
    project_id char(36) NOT NULL,
    topic_subject VARCHAR(255) NOT NULL,
    topic_content TEXT default NULL,
    date_created DATETIME NOT NULL,
    date_last_post DATETIME NOT NULL,
    created_by_user_id char(36) NOT NULL,
    last_post_user_id char(36) NOT NULL,
    posts_count char(36) default NULL,
    PRIMARY KEY (topic_id)
) ENGINE=InnoDB DEFAULT CHARSET=utf8 AUTO_INCREMENT=1;

how to generate a unique token which expires after 24 hours?

you need to store the token while creating for 1st registration. When you retrieve data from login table you need to differentiate entered date with current date if it is more than 1 day (24 hours) you need to display message like your token is expired.

To generate key refer here

How can I get last characters of a string

I actually have the following problem and this how i solved it by the help of above answer but different approach in extracting id form a an input element.

I have attached input filed with an

id="rating_element-<?php echo $id?>"

And , when that button clicked i want to extract the id(which is the number) or the php ID ($id) only.

So here what i do .

 $('.rating').on('rating.change', function() {
            alert($(this).val());
           // console.log(this.id);
           var static_id_text=("rating_element-").length;       
           var product_id =  this.id.slice(static_id_text);       //get the length in order to deduct from the whole string    
          console.log(product_id );//outputs the last id appended
        });

Change visibility of ASP.NET label with JavaScript

If you wait until the page is loaded, and then set the button's display to none, that should work. Then you can make it visible at a later point.

Data-frame Object has no Attribute

Check your DataFrame with data.columns

It should print something like this

Index([u'regiment', u'company',  u'name',u'postTestScore'], dtype='object')

Check for hidden white spaces..Then you can rename with

data = data.rename(columns={'Number ': 'Number'})

Postgres manually alter sequence

The parentheses are misplaced:

SELECT setval('payments_id_seq', 21, true);  # next value will be 22

Otherwise you're calling setval with a single argument, while it requires two or three.

Spark : how to run spark file from spark shell

Just to give more perspective to the answers

Spark-shell is a scala repl

You can type :help to see the list of operation that are possible inside the scala shell

scala> :help
All commands can be abbreviated, e.g., :he instead of :help.
:edit <id>|<line>        edit history
:help [command]          print this summary or command-specific help
:history [num]           show the history (optional num is commands to show)
:h? <string>             search the history
:imports [name name ...] show import history, identifying sources of names
:implicits [-v]          show the implicits in scope
:javap <path|class>      disassemble a file or class name
:line <id>|<line>        place line(s) at the end of history
:load <path>             interpret lines in a file
:paste [-raw] [path]     enter paste mode or paste a file
:power                   enable power user mode
:quit                    exit the interpreter
:replay [options]        reset the repl and replay all previous commands
:require <path>          add a jar to the classpath
:reset [options]         reset the repl to its initial state, forgetting all session entries
:save <path>             save replayable session to a file
:sh <command line>       run a shell command (result is implicitly => List[String])
:settings <options>      update compiler options, if possible; see reset
:silent                  disable/enable automatic printing of results
:type [-v] <expr>        display the type of an expression without evaluating it
:kind [-v] <expr>        display the kind of expression's type
:warnings                show the suppressed warnings from the most recent line which had any

:load interpret lines in a file

Calling a stored procedure in Oracle with IN and OUT parameters

Go to Menu Tool -> SQL Output, Run the PL/SQL statement, the output will show on SQL Output panel.

ruby LoadError: cannot load such file

I just came across a similar problem. Try

require './st.rb'

This should do the trick.

applying css to specific li class

I believe it's because #ID styles trump .class styles when computing the final style of an element. Try changing your li from class to id, or you can try adding !important to your class, like this:

li.sub-navigation-home-news
{
    color: #C1C1C1; !important

Select element by exact match of its content

So Amandu's answer mostly works. Using it in the wild, however, I ran into some issues, where things that I would have expected to get found were not getting found. This was because sometimes there is random white space surrounding the element's text. It is my belief that if you're searching for "Hello World", you would still want it to match " Hello World ", or even "Hello World \n". Thus, I just added the "trim()" method to the function, which removes surrounding whitespace, and it started to work better.

Specifically...

$.expr[':'].textEquals = function(el, i, m) {
    var searchText = m[3];
    var match = $(el).text().trim().match("^" + searchText + "$")
    return match && match.length > 0;
}

Also, note, this answer is extremely similar to Select link by text (exact match)

And secondary note... trim only removes whitespace before and after the searched text. It does not remove whitespace in the middle of the words. I believe this is desirable behavior, but you could change that if you wanted.

Multiple WHERE clause in Linq

@Theo

The LINQ translator is smart enough to execute:

.Where(r => r.UserName !="XXXX" && r.UsernName !="YYYY")

I've test this in LinqPad ==> YES, Linq translator is smart enough :))

Auto margins don't center image in page

img{display: flex; max-width: 80%; margin: auto;}

This is working for me. You can also use display: table in this case. Moreover, if you don't want to stick to this approach you can use the following:

img{position: relative; left: 50%;}

Convert number to varchar in SQL with formatting

Had the same problem with a zipcode field. Some folks sent me an excel file with zips, but they were formatted as #'s. Had to convert them to strings as well as prepend leading 0's to them if they were < 5 len ...

declare @int tinyint
set     @int = 25
declare @len tinyint
set     @len = 3

select right(replicate('0', @len) + cast(@int as varchar(255)), @len)

You just alter the @len to get what you want. As formatted, you'll get...

001
002
...
010
011
...
255

Ideally you'd "varchar(@len)", too, but that blows up the SQL compile. Have to toss an actual # into it instead of a var.

Cannot attach the file *.mdf as database

Recreate your database. Do not delete it and your app should continue to work.

Is there possibility of sum of ArrayList without looping

You can use GNU Trove library:

TIntList tt = new TIntArrayList();
tt.add(1);
tt.add(2);
tt.add(3);
int sum = tt.sum();

How to do a for loop in windows command line?

The commandline interpreter does indeed have a FOR construct that you can use from the command prompt or from within a batch file.

For your purpose, you probably want something like:

FOR %i IN (*.ext) DO my-function %i

Which will result in the name of each file with extension *.ext in the current directory being passed to my-function (which could, for example, be another .bat file).

The (*.ext) part is the "filespec", and is pretty flexible with how you specify sets of files. For example, you could do:

FOR %i IN (C:\Some\Other\Dir\*.ext) DO my-function %i

To perform an operation in a different directory.

There are scores of options for the filespec and FOR in general. See

HELP FOR

from the command prompt for more information.

How to check for the type of a template parameter?

Use is_same:

#include <type_traits>

template <typename T>
void foo()
{
    if (std::is_same<T, animal>::value) { /* ... */ }  // optimizable...
}

Usually, that's a totally unworkable design, though, and you really want to specialize:

template <typename T> void foo() { /* generic implementation  */ }

template <> void foo<animal>()   { /* specific for T = animal */ }

Note also that it's unusual to have function templates with explicit (non-deduced) arguments. It's not unheard of, but often there are better approaches.

SQL Server: How to check if CLR is enabled?

Check the config_value in the results of sp_configure

You can enable CLR by running the following:

sp_configure 'show advanced options', 1;
GO
RECONFIGURE;
GO
sp_configure 'clr enabled', 1;
GO
RECONFIGURE;
GO

MSDN Article on enabling CLR

MSDN Article on sp_configure

How do I get IntelliJ to recognize common Python modules?

My problem was similar to @Toddarooski 's, except that the module I had, under the "Dependencies" tab, had no SDK listed. I right clicked on 'SDK', picked edit from the drop down menu, and selected my Python SDK. That did the trick.

HtmlEncode from Class Library

Just reference the System.Web assembly and then call: HttpServerUtility.HtmlEncode

http://msdn.microsoft.com/en-us/library/system.web.httpserverutility.htmlencode.aspx

Cannot execute script: Insufficient memory to continue the execution of the program

For Windows Authentication use this sql cmd

SQLCMD -S TestSQLServer\SQLEXPRESS  -d AdventureWorks2018 -i "d:\document\sql document\script.sql"

Note: If there is any space in the sql file path then use " (Quotation marks) "

For SQL Server Authentication use this sql cmd

SQLCMD -S TestSQLServer\SQLEXPRESS -U sa -P sasa  -d AdventureWorks2018 -i "d:\document\sql document\script.sql"

-S TestSQLServer\SQLEXPRESS: Here specify SQL Server Name

-U sa: Username (in case of SQL Server Authentication)

-P sasa: Password (in case of SQL Server Authentication)

-d AdventureWorks2018: Database Name come here

-i "d:\document\sql document\script.sql": File Path of SQLFile

Excel 2010 VBA Referencing Specific Cells in other worksheets

Sub Results2()

    Dim rCell As Range
    Dim shSource As Worksheet
    Dim shDest As Worksheet
    Dim lCnt As Long

    Set shSource = ThisWorkbook.Sheets("Sheet1")
    Set shDest = ThisWorkbook.Sheets("Sheet2")

    For Each rCell In shSource.Range("A1", shSource.Cells(shSource.Rows.Count, 1).End(xlUp)).Cells
        lCnt = lCnt + 1
        shDest.Range("A4").Offset(0, lCnt * 4).Formula = "=" & rCell.Address(False, False, , True) & "+" & rCell.Offset(0, 1).Address(False, False, , True)
    Next rCell

End Sub

This loops through column A of sheet1 and creates a formula in sheet2 for every cell. To find the last cell in Sheet1, I start at the bottom (shSource.Rows.Count) and .End(xlUp) to get the last cell in the column that's not blank.

To create the elements of the formula, I use the Address property of the cell on Sheet. I'm using three of the arguments to Address. The first two are RowAbsolute and ColumnAbsolute, both set to false. I don't care about the third argument, but I set the fourth argument (External) to True so that it includes the sheet name.

I prefer to go from Source to Destination rather than the other way. But that's just a personal preference. If you want to work from the destination,

Sub Results3()

    Dim i As Long, lCnt As Long
    Dim sh As Worksheet

    lCnt = Application.WorksheetFunction.CountA(ThisWorkbook.Sheets("Sheet1").Columns(1))
    Set sh = ThisWorkbook.Sheets("Sheet2")

    Const sSOURCE As String = "Sheet1!"

    For i = 1 To lCnt
        sh.Range("A1").Offset(0, 4 * (i - 1)).Formula = "=" & sSOURCE & "A" & i & " + " & sSOURCE & "B" & i
    Next i

End Sub

Official reasons for "Software caused connection abort: socket write error"

The java.net.SocketException is thrown when there is an error creating or accessing a socket (such as TCP). This usually can be caused when the server has terminated the connection (without properly closing it), so before getting the full response. In most cases this can be caused either by the timeout issue (e.g. the response takes too much time or server is overloaded with the requests), or the client sent the SYN, but it didn't receive ACK (acknowledgment of the connection termination). For timeout issues, you can consider increasing the timeout value.

The Socket Exception usually comes with the specified detail message about the issue.

Example of detailed messages:

  • Software caused connection abort: recv failed.

    The error indicates an attempt to send the message and the connection has been aborted by your server. If this happened while connecting to the database, this can be related to using not compatible Connector/J JDBC driver.

    Possible solution: Make sure you've proper libraries/drivers in your CLASSPATH.

  • Software caused connection abort: connect.

    This can happen when there is a problem to connect to the remote. For example due to virus-checker rejecting the remote mail requests.

    Possible solution: Check Virus scan service whether it's blocking the port for the outgoing requests for connections.

  • Software caused connection abort: socket write error.

    Possible solution: Make sure you're writing the correct length of bytes to the stream. So double check what you're sending. See this thread.

  • Connection reset by peer: socket write error / Connection aborted by peer: socket write error

    The application did not check whether keep-alive connection had been timed out on the server side.

    Possible solution: Ensure that the HttpClient is non-null before reading from the connection.E13222_01

  • Connection reset by peer.

    The connection has been terminated by the peer (server).

  • Connection reset.

    The connection has been either terminated by the client or closed by the server end of the connection due to request with the request.

    See: What's causing my java.net.SocketException: Connection reset?

How do I get AWS_ACCESS_KEY_ID for Amazon?

  1. Open the AWS Console
  2. Click on your username near the top right and select My Security Credentials
  3. Click on Users in the sidebar
  4. Click on your username
  5. Click on the Security Credentials tab
  6. Click Create Access Key
  7. Click Show User Security Credentials

How to Add Date Picker To VBA UserForm

Just throw some light in to some issues related to this control.

Date picker is not a standard control that comes with office package. So developers encountered issues like missing date picker controls when application deployed in some other machiens/versions of office. In order to use it you have to activate the reference to the .dll, .ocx file that contains it.

In the event of a missing date picker, you have to replace MSCOMCT2.OCX file in System or System32 directory and register it properly. Try this link to do the proper replacement of the file.

In the VBA editor menu bar-> select tools-> references and then find the date picker reference and check it.

If you need the file, download MSCOMCT2.OCX from here.

ios simulator: how to close an app

For closing (not quit) the running application in Simulator the keyboard shortcut is "shift+command+h".

Download a div in a HTML page as pdf using javascript

You can do it using jsPDF

HTML:

<div id="content">
     <h3>Hello, this is a H3 tag</h3>

    <p>A paragraph</p>
</div>
<div id="editor"></div>
<button id="cmd">generate PDF</button>

JavaScript:

var doc = new jsPDF();
var specialElementHandlers = {
    '#editor': function (element, renderer) {
        return true;
    }
};

$('#cmd').click(function () {
    doc.fromHTML($('#content').html(), 15, 15, {
        'width': 170,
            'elementHandlers': specialElementHandlers
    });
    doc.save('sample-file.pdf');
});

Complex CSS selector for parent of active child

Future answer with CSS4 selectors

New CSS Specs contain an experimental :has pseudo selector that might be able to do this thing.

li:has(a:active) {
  /* ... */
}

The browser support on this is basically non-existent at this time, but it is in consideration on the official specs.


Answer in 2012 that was wrong in 2012 and is even more wrong in 2018

While it is true that CSS cannot ASCEND, it is incorrect that you cannot grab the parent element of another element. Let me reiterate:

Using your HTML example code, you are able to grab the li without specifying li

ul * a {
    property:value;
}

In this example, the ul is the parent of some element and that element is the parent of anchor. The downside of using this method is that if there is a ul with any child element that contains an anchor, it inherits the styles specified.

You may also use the child selector as well since you'll have to specify the parent element anyway.

ul>li a {
    property:value;
}

In this example, the anchor must be a descendant of an li that MUST be a child of ul, meaning it must be within the tree following the ul declaration. This is going to be a bit more specific and will only grab a list item that contains an anchor AND is a child of ul.

SO, to answer your question by code.

ul.menu > li a.active {
    property:value;
}

This should grab the ul with the class of menu, and the child list item that contains only an anchor with the class of active.

Printing an int list in a single line python3

Maybe this code will help you.

>>> def sort(lists):
...     lists.sort()
...     return lists
...
>>> datalist = [6,3,4,1,3,2,9]
>>> print(*sort(datalist), end=" ")
1 2 3 3 4 6 9

you can use an empty list variable to collect the user input, with method append(). and if you want to print list in one line you can use print(*list)

Getting the last element of a list

Another method:

some_list.reverse() 
some_list[0]

Java: How to Indent XML Generated by Transformer

The following code is working for me with Java 7. I set the indent (yes) and indent-amount (2) on the transformer (not the transformer factory) to get it working.

TransformerFactory tf = TransformerFactory.newInstance();
Transformer t = tf.newTransformer();
t.setOutputProperty("{http://xml.apache.org/xslt}indent-amount", "2");
t.setOutputProperty(OutputKeys.INDENT, "yes");
t.transform(source, result);

@mabac's solution to set the attribute didn't work for me, but @lapo's comment proved helpful.

Difference between <span> and <div> with text-align:center;?

A span tag is only as wide as its contents, so there is no 'center' of a span tag. There is no extra space on either side of the content.

A div tag, however, is as wide as its containing element, so the content of that div can be centered using any extra space that the content doesn't take up.

So if your div is 100px width and your content only takes 50px, the browser will divide the remaining 50px by 2 and pad 25px on each side of your content to center it.

Check if value exists in the array (AngularJS)

You could use indexOf function.

if(list.indexOf(createItem.artNr) !== -1) {
  $scope.message = 'artNr already exists!';
}

More about indexOf:

Putting a password to a user in PhpMyAdmin in Wamp

There is a file called config.inc.php in the phpmyadmin folder.

The file path is C:\wamp\apps\phpmyadmin4.0.4

Edit The auth_type 'cookie' to 'config' or 'http'

$cfg['Servers'][$i]['auth_type'] = 'cookie';

$cfg['Servers'][$i]['auth_type'] = 'config';

or

$cfg['Servers'][$i]['auth_type'] = 'http';

When you go to the phpmyadmin site then you will be asked for the username and password. This also secure external people from accessing your phpmyadmin application if you happen to have your web server exposed to outside connections.

URL encoding in Android

For android, I would use String android.net.Uri.encode(String s)

Encodes characters in the given string as '%'-escaped octets using the UTF-8 scheme. Leaves letters ("A-Z", "a-z"), numbers ("0-9"), and unreserved characters ("_-!.~'()*") intact. Encodes all other characters.

Ex/

String urlEncoded = "http://stackoverflow.com/search?q=" + Uri.encode(query);

The program can't start because cygwin1.dll is missing... in Eclipse CDT

This error message means that Windows isn't able to find "cygwin1.dll". The Programs that the Cygwin gcc create depend on this DLL. The file is part of cygwin , so most likely it's located in C:\cygwin\bin. To fix the problem all you have to do is add C:\cygwin\bin (or the location where cygwin1.dll can be found) to your system path. Alternatively you can copy cygwin1.dll into your Windows directory.

There is a nice tool called DependencyWalker that you can download from http://www.dependencywalker.com . You can use it to check dependencies of executables, so if you inspect your generated program it tells you which dependencies are missing and which are resolved.

Why doesn't Git ignore my specified file?

There are instances e.g. Application Configuration files, which I want tracked in git (so .gitignore will not work), but that I need to change for local settings. I do not want git to manage these files or show them as modified. To do this I use skip-worktree:

git update-index --skip-worktree path/to/file

You can confirm files are skipped by listing files and checking for lines starting with S for skipped

git ls-files -v | grep ^S

If in the future you want to have git manage the file locally again simply run:

 git update-index --no-skip-worktree path/to/file

Mescalito above had a great answer, that led me down the right track but

git update-index --assume-unchanged file/to/ignore.php

Has a contract with git that in which : the user promises not to change the file and allows Git to assume that the working tree file matches what is recorded in the index.

However, I change the content of the files, so in my case --skip-worktree is the better option.

Toshiharu Nishina's website provided an excellent explanation of skip-worktree vs assume-unchanged: Ignore files already managed with Git locally

Why doesn't importing java.util.* include Arrays and Lists?

I have just compile it and it compiles fine without the implicit import, probably you're seeing a stale cache or something of your IDE.

Have you tried compiling from the command line?

I have the exact same version:

here it is

Probably you're thinking the warning is an error.

UPDATE

It looks like you have a Arrays.class file in the directory where you're trying to compile ( probably created before ). That's why the explicit import solves the problem. Try copying your source code to a clean new directory and try again. You'll see there is no error this time. Or, clean up your working directory and remove the Arrays.class

Call PHP function from jQuery?

This is exactly what ajax is for. See here:

http://api.jquery.com/load/

Basically, you ajax/test.php and put the returned HTML code to the element which has the result id.

$('#result').load('ajax/test.php');

Of course, you will need to put the functionality which takes time to a new php file (or call the old one with a GET parameter which will activate that functionality only).

Check if something is (not) in a list in Python

The bug is probably somewhere else in your code, because it should work fine:

>>> 3 not in [2, 3, 4]
False
>>> 3 not in [4, 5, 6]
True

Or with tuples:

>>> (2, 3) not in [(2, 3), (5, 6), (9, 1)]
False
>>> (2, 3) not in [(2, 7), (7, 3), "hi"]
True

"Invalid JSON primitive" in Ajax processing

On the Server, to Serialize/Deserialize json to custom objects:

public static string Serialize<T>(T obj)
{
    DataContractJsonSerializer serializer = new DataContractJsonSerializer(obj.GetType());
    MemoryStream ms = new MemoryStream();
    serializer.WriteObject(ms, obj);
    string retVal = Encoding.UTF8.GetString(ms.ToArray());
    return retVal;
}

public static T Deserialize<T>(string json)
{
    T obj = Activator.CreateInstance<T>();
    MemoryStream ms = new MemoryStream(Encoding.Unicode.GetBytes(json));
    DataContractJsonSerializer serializer = new DataContractJsonSerializer(obj.GetType());
    obj = (T)serializer.ReadObject(ms);
    ms.Close();
    return obj;
}

Pass by pointer & Pass by reference

Use references all the time and pointers only when you have to refer to NULL which reference cannot refer.

See this FAQ : http://www.parashift.com/c++-faq-lite/references.html#faq-8.6

What is the path that Django uses for locating and loading templates?

basically BASE_DIR is your django project directory, same dir where manage.py is.

    TEMPLATES = [
        {
            'BACKEND': 'django.template.backends.django.DjangoTemplates',
            'DIRS': [os.path.join(BASE_DIR, 'templates')],
            'APP_DIRS': True,
            'OPTIONS': {
                'context_processors': [
                    'django.template.context_processors.debug',
                    'django.template.context_processors.request',
                    'django.contrib.auth.context_processors.auth',
                    'django.contrib.messages.context_processors.messages',
                ],
            },
        },
    ]

How do I get the list of keys in a Dictionary?

I often used this to get the key and value inside a dictionary: (VB.Net)

 For Each kv As KeyValuePair(Of String, Integer) In layerList

 Next

(layerList is of type Dictionary(Of String, Integer))

How to unescape a Java string literal in Java?

If you are reading unicode escaped chars from a file, then you will have a tough time doing that because the string will be read literally along with an escape for the back slash:

my_file.txt

Blah blah...
Column delimiter=;
Word delimiter=\u0020 #This is just unicode for whitespace

.. more stuff

Here, when you read line 3 from the file the string/line will have:

"Word delimiter=\u0020 #This is just unicode for whitespace"

and the char[] in the string will show:

{...., '=', '\\', 'u', '0', '0', '2', '0', ' ', '#', 't', 'h', ...}

Commons StringUnescape will not unescape this for you (I tried unescapeXml()). You'll have to do it manually as described here.

So, the sub-string "\u0020" should become 1 single char '\u0020'

But if you are using this "\u0020" to do String.split("... ..... ..", columnDelimiterReadFromFile) which is really using regex internally, it will work directly because the string read from file was escaped and is perfect to use in the regex pattern!! (Confused?)

How to set Internet options for Android emulator?

On a slightly different note, I had to make a virtual device without GSM Modem Support so that the internet on my emulator would work.

How to assert two list contain the same elements in Python?

Slightly faster version of the implementation (If you know that most couples lists will have different lengths):

def checkEqual(L1, L2):
    return len(L1) == len(L2) and sorted(L1) == sorted(L2)

Comparing:

>>> timeit(lambda: sorting([1,2,3], [3,2,1]))
2.42745304107666
>>> timeit(lambda: lensorting([1,2,3], [3,2,1]))
2.5644469261169434 # speed down not much (for large lists the difference tends to 0)

>>> timeit(lambda: sorting([1,2,3], [3,2,1,0]))
2.4570400714874268
>>> timeit(lambda: lensorting([1,2,3], [3,2,1,0]))
0.9596951007843018 # speed up

Concatenating strings in Razor

String.Format also works in Razor:

String.Format("{0} - {1}", Model.address, Model.city)

PivotTable to show values, not sum of values

I fear this might turn out to BE the long way round but could depend on how big your data set is – presumably more than four months for example.

Assuming your data is in ColumnA:C and has column labels in Row 1, also that Month is formatted mmm(this last for ease of sorting):

  1. Sort the data by Name then Month
  2. Enter in D2 =IF(AND(A2=A1,C2=C1),D1+1,1) (One way to deal with what is the tricky issue of multiple entries for the same person for the same month).
  3. Create a pivot table from A1:D(last occupied row no.)
  4. Say insert in F1.
  5. Layout as in screenshot.

SO12803305 example

I’m hoping this would be adequate for your needs because pivot table should automatically update (provided range is appropriate) in response to additional data with refresh. If not (you hard taskmaster), continue but beware that the following steps would need to be repeated each time the source data changes.

  1. Copy pivot table and Paste Special/Values to, say, L1.
  2. Delete top row of copied range with shift cells up.
  3. Insert new cell at L1 and shift down.
  4. Key 'Name' into L1.
  5. Filter copied range and for ColumnL, select Row Labels and numeric values.
  6. Delete contents of L2:L(last selected cell)
  7. Delete blank rows in copied range with shift cells up (may best via adding a column that counts all 12 months). Hopefully result should be as highlighted in yellow.

Happy to explain further/try again (I've not really tested this) if does not suit.

EDIT (To avoid second block of steps above and facilitate updating for source data changes)

.0. Before first step 2. add a blank row at the very top and move A2:D2 up.
.2. Adjust cell references accordingly (in D3 =IF(AND(A3=A2,C3=C2),D2+1,1).
.3. Create pivot table from A:D

.6. Overwrite Row Labels with Name.
.7. PivotTable Tools, Design, Report Layout, Show in Tabular Form and sort rows and columns A>Z.
.8. Hide Row1, ColumnG and rows and columns that show (blank).

additional example

Steps .0. and .2. in the edit are not required if the pivot table is in a different sheet from the source data (recommended).

Step .3. in the edit is a change to simplify the consequences of expanding the source data set. However introduces (blank) into pivot table that if to be hidden may need adjustment on refresh. So may be better to adjust source data range each time that changes instead: PivotTable Tools, Options, Change Data Source, Change Data Source, Select a table or range). In which case copy rather than move in .0.

Row was updated or deleted by another transaction (or unsaved-value mapping was incorrect)

I know this is an old question, but some of us are still hitting it and look at the sky wondering how. Here is one kind of issue that I faced.

We have a queue manager that polls data and gives it to handlers for processing. To avoid picking up the same events again, the queue manager locks the record in the database with a LOCKED state.

    void poll() {
        record = dao.getLockedEntity();
        queue(record);
    }

this method wasn't transactional but dao.getLockedEntity() was transactional with REQUIRED.

All good and on the road, after few months in production, it failed with an optimistic locking exception.

After lots of debugging and checking in details we could find out that some one has changed the code like this:

    @Transactional(propagation=Propagation.REQUIRED, readOnly=false)
    void poll() {
        record = dao.getLockedEntity();
        queue(record);              
    }

So the record was queued even before the transaction in dao.getLockedEntity() gets committed (it uses the same transaction of poll method) and the object was changed underneath by the handlers (different threads) by the time the poll() method transaction gets committed.

We fixed the issue and it looks good now.

I thought of sharing it because optimistic lock exceptions can be confusing and are difficult to debug. Someone might get benefited from my experience.

Regards, Lyju

How do I make a checkbox required on an ASP.NET form?

I typically perform the validation on the client side:

<asp:checkbox id="chkTerms" text=" I agree to the terms" ValidationGroup="vg" runat="Server"  />
<asp:CustomValidator id="vTerms"
                ClientValidationFunction="validateTerms" 
                ErrorMessage="<br/>Terms and Conditions are required." 
                ForeColor="Red"
                Display="Static"
                EnableClientScript="true"
                ValidationGroup="vg"
                runat="server"/>

<asp:Button ID="btnSubmit" OnClick="btnSubmit_Click" CausesValidation="true" Text="Submit" ValidationGroup="vg" runat="server" />

<script>
    function validateTerms(source, arguments) {
        var $c = $('#<%= chkTerms.ClientID %>');
        if($c.prop("checked")){
            arguments.IsValid = true;
        } else {
            arguments.IsValid = false;
        }
    }
</script>       

Get all Attributes from a HTML element with Javascript/jQuery

Try something like this

    <div id=foo [href]="url" class (click)="alert('hello')" data-hello=world></div>

and then get all attributes

    const foo = document.getElementById('foo');
    // or if you have a jQuery object
    // const foo = $('#foo')[0];

    function getAttributes(el) {
        const attrObj = {};
        if(!el.hasAttributes()) return attrObj;
        for (const attr of el.attributes)
            attrObj[attr.name] = attr.value;
        return attrObj
    }

    // {"id":"foo","[href]":"url","class":"","(click)":"alert('hello')","data-hello":"world"}
    console.log(getAttributes(foo));

for array of attributes use

    // ["id","[href]","class","(click)","data-hello"]
    Object.keys(getAttributes(foo))

Remove 'b' character do in front of a string literal in Python 3

This should do the trick:

pw_bytes.decode("utf-8")

The project type is not supported by this installation

I was having this problem trying to add a WPF project in a WCF solution in Visual Studio Express 2012 for Web. Deleting the content between the "ProjectTypeGuids" tags and leaving only the tags solved the problem. To know how to edit the .csproj file, read MindStalker comment.

SQL Server database backup restore on lower version

Will not necessarily work

Will work

  • Script generation - Tasks -> Generate Scripts. Make sure you set the desired target SQL Server version on the Set Scripting Options -> Advanced page. You can also choose there whether to copy schema, data, or both. Note that in the generated script, you may need to change the DATA folder for the mdf/ldf files if moving from non-express to express or vice versa.

  • Microsoft SQL Server Database Publishing Services - comes with SQL Server 2005 and above, I think. Download the latest version from here. Prerequisites: sqlncli.msi/sqlncli_x64.msi/sqlncli_ia64.msi, SQLServer2005_XMO.msi/SQLServer2005_XMO_x64.msi/SQLServer2005_XMO_ia64.msi (download here).

Could not load file or assembly 'Microsoft.ReportViewer.WebForms'

I ran into the same error. My web app was pointed towards report viewer version 10.0 however if 11.0 is installed it adds a redirect in the 10.0 .dll to 11.0. This became an issue when 11.0 was uninstalled as this does not correct the redirect in the 10.0 .dll. The fix in my case was to simply uninstall and reinstall 10.0.

jquery $(window).height() is returning the document height

Here's a question and answer for this: Difference between screen.availHeight and window.height()

Has pics too, so you can actually see the differences. Hope this helps.

Basically, $(window).height() give you the maximum height inside of the browser window (viewport), and$(document).height() gives you the height of the document inside of the browser. Most of the time, they will be exactly the same, even with scrollbars.

Node/Express file upload

const http          = require('http');
const fs            = require('fs');

// https://www.npmjs.com/package/formidable
const formidable    = require('formidable');

// https://stackoverflow.com/questions/31317007/get-full-file-path-in-node-js
const path          = require('path');

router.post('/upload', (req, res) => {
    console.log(req.files);

    let oldpath = req.files.fileUploaded.path;

    // https://stackoverflow.com/questions/31317007/get-full-file-path-in-node-js       
    let newpath = path.resolve( `./${req.files.fileUploaded.name}` );

    // copy
    // https://stackoverflow.com/questions/43206198/what-does-the-exdev-cross-device-link-not-permitted-error-mean
    fs.copyFile( oldpath, newpath, (err) => {

        if (err) throw err;

        // delete
        fs.unlink( oldpath, (err) => {

            if (err) throw err;

            console.log('Success uploaded")
        } );                

    } );

});

Converting year and month ("yyyy-mm" format) to a date?

Indeed, as has been mentioned above (and elsewhere on SO), in order to convert the string to a date, you need a specific date of the month. From the as.Date() manual page:

If the date string does not specify the date completely, the returned answer may be system-specific. The most common behaviour is to assume that a missing year, month or day is the current one. If it specifies a date incorrectly, reliable implementations will give an error and the date is reported as NA. Unfortunately some common implementations (such as glibc) are unreliable and guess at the intended meaning.

A simple solution would be to paste the date "01" to each date and use strptime() to indicate it as the first day of that month.


For those seeking a little more background on processing dates and times in R:

In R, times use POSIXct and POSIXlt classes and dates use the Date class.

Dates are stored as the number of days since January 1st, 1970 and times are stored as the number of seconds since January 1st, 1970.

So, for example:

d <- as.Date("1971-01-01")
unclass(d)  # one year after 1970-01-01
# [1] 365

pct <- Sys.time()  # in POSIXct
unclass(pct)  # number of seconds since 1970-01-01
# [1] 1450276559
plt <- as.POSIXlt(pct)
up <- unclass(plt)  # up is now a list containing the components of time
names(up)
# [1] "sec"    "min"    "hour"   "mday"   "mon"    "year"   "wday"   "yday"   "isdst"  "zone"  
# [11] "gmtoff"
up$hour
# [1] 9

To perform operations on dates and times:

plt - as.POSIXlt(d)
# Time difference of 16420.61 days

And to process dates, you can use strptime() (borrowing these examples from the manual page):

strptime("20/2/06 11:16:16.683", "%d/%m/%y %H:%M:%OS")
# [1] "2006-02-20 11:16:16 EST"

# And in vectorized form:
dates <- c("1jan1960", "2jan1960", "31mar1960", "30jul1960")
strptime(dates, "%d%b%Y")
# [1] "1960-01-01 EST" "1960-01-02 EST" "1960-03-31 EST" "1960-07-30 EDT"

Spring Boot: Is it possible to use external application.properties files in arbitrary directories with a fat jar?

If you have not changed the defaults of Spring Boot (meaning you are using @EnableAutoConfiguration or @SpringBootApplication and have not changed any Property Source handling), then it will look for properties with the following order (highest overrides lowest):

  1. A /config subdir of the current directory
  2. The current directory
  3. A classpath /config package
  4. The classpath root

The list above is mentioned in this part of the documentation

What that means is that if a property is found for example application.properties under src/resources is will be overridden by a property with the same name found in application.properties in the /config directory that is "next" to the packaged jar.

This default order used by Spring Boot allows for very easy configuration externalization which in turn makes applications easy to configure in multiple environments (dev, staging, production, cloud etc)

To see the whole set of features provided by Spring Boot for property reading (hint: there is a lot more available than reading from application.properties) check out this part of the documentation.

As one can see from my short description above or from the full documentation, Spring Boot apps are very DevOps friendly!

Cannot access mongodb through browser - It looks like you are trying to access MongoDB over HTTP on the native driver port

MongoDB has a simple web based administrative port at 28017 by default.

There is no HTTP access at the default port of 27017 (which is what the error message is trying to suggest). The default port is used for native driver access, not HTTP traffic.

To access MongoDB, you'll need to use a driver like the MongoDB native driver for NodeJS. You won't "POST" to MongoDB directly (but you might create a RESTful API using express which uses the native drivers). Instead, you'll use a wrapper library that makes accessing MongoDB convenient. You might also consider using Mongoose (which uses the native driver) which adds an ORM-like model for MongoDB in NodeJS.

If you can't get to the web interface, it may be disabled. Normally, I wouldn't expect that you'd need it for doing development unless you're checking logs and such.

How do I remove version tracking from a project cloned from git?

In a Windows environment you can remove Git tracking from a project's directory by simply typing the below.

rd .git /S/Q

Embedding JavaScript engine into .NET

You can try ironJS, looks promising although it is in heavy development. https://github.com/fholm/IronJS

SQL Transaction Error: The current transaction cannot be committed and cannot support operations that write to the log file

There are a few misunderstandings in the discussion above.

First, you can always ROLLBACK a transaction... no matter what the state of the transaction. So you only have to check the XACT_STATE before a COMMIT, not before a rollback.

As far as the error in the code, you will want to put the transaction inside the TRY. Then in your CATCH, the first thing you should do is the following:

 IF @@TRANCOUNT > 0
      ROLLBACK TRANSACTION @transaction

Then, after the statement above, then you can send an email or whatever is needed. (FYI: If you send the email BEFORE the rollback, then you will definitely get the "cannot... write to log file" error.)

This issue was from last year, so I hope you have resolved this by now :-) Remus pointed you in the right direction.

As a rule of thumb... the TRY will immediately jump to the CATCH when there is an error. Then, when you're in the CATCH, you can use the XACT_STATE to decide whether you can commit. But if you always want to ROLLBACK in the catch, then you don't need to check the state at all.

SVN change username

You can change the user with

  • Subversion 1.6 and earlier:

    svn switch --relocate protocol://currentUser@server/path protocol://newUser@server/path
    
  • Subversion 1.7 and later:

    svn relocate protocol://currentUser@server/path protocol://newUser@server/path
    

To find out what protocol://currentUser@server/path is, run

svn info

in your working copy.

How to horizontally center an unordered list of unknown width?

Use the below css to solve your issue

#footer{ text-align:center; height:58px;}
#footer ul {  font-size:11px;}
#footer ul li {display:inline-block;}

Note: Don't use float:left in li. it will make your li to align left.

Simple two column html layout without using tables

a few small changes to make it responsive

<style type="text/css">
#wrap {
    width: 100%;
    margin: 0 auto;
    display: table;
}
#left_col {
   float:left;
   width:50%;
}
#right_col {
   float:right;
   width:50%;
}
@media only screen and (max-width: 480px){
    #left_col {
       width:100%;
    }
    #right_col {
       width:100%;
    }
}
</style>

<div id="wrap">
    <div id="left_col">
        ...
    </div>
    <div id="right_col">
        ...
    </div>
</div>

The difference between Classes, Objects, and Instances

If you have a program that models cars you have a class to represent cars, so in Code you could say:

Car someCar = new Car();

someCar is now an instance of the class Car. If the program is used at a repairshop and the someCar represents your car in their system, then your car is the object.

So Car is a class that can represent any real world car someCar is an instance of the Car class and someCare represents one real life object (your car)

however instance and object is very often used interchangably when it comes to discussing coding

Bootstrap carousel multiple frames at once

This is what worked for me. Very simple jQuery and CSS to make responsive carousel works independently of carousels on the same page. Highly customizable but basically a div with white-space nowrap containing a bunch of inline-block elements and put the last one at the beginning to move back or the first one to the end to move forward. Thank you insertAfter!

_x000D_
_x000D_
$('.carosel-control-right').click(function() {_x000D_
  $(this).blur();_x000D_
  $(this).parent().find('.carosel-item').first().insertAfter($(this).parent().find('.carosel-item').last());_x000D_
});_x000D_
$('.carosel-control-left').click(function() {_x000D_
  $(this).blur();_x000D_
  $(this).parent().find('.carosel-item').last().insertBefore($(this).parent().find('.carosel-item').first());_x000D_
});
_x000D_
@media (max-width: 300px) {_x000D_
  .carosel-item {_x000D_
    width: 100%;_x000D_
  }_x000D_
}_x000D_
@media (min-width: 300px) {_x000D_
  .carosel-item {_x000D_
    width: 50%;_x000D_
  }_x000D_
}_x000D_
@media (min-width: 500px) {_x000D_
  .carosel-item {_x000D_
    width: 33.333%;_x000D_
  }_x000D_
}_x000D_
@media (min-width: 768px) {_x000D_
  .carosel-item {_x000D_
    width: 25%;_x000D_
  }_x000D_
}_x000D_
.carosel {_x000D_
  position: relative;_x000D_
  background-color: #000;_x000D_
}_x000D_
.carosel-inner {_x000D_
  white-space: nowrap;_x000D_
  overflow: hidden;_x000D_
  font-size: 0;_x000D_
}_x000D_
.carosel-item {_x000D_
  display: inline-block;_x000D_
}_x000D_
.carosel-control {_x000D_
  position: absolute;_x000D_
  top: 50%;_x000D_
  padding: 15px;_x000D_
  box-shadow: 0 0 10px 0px rgba(0, 0, 0, 0.5);_x000D_
  transform: translateY(-50%);_x000D_
  border-radius: 50%;_x000D_
  color: rgba(0, 0, 0, 0.5);_x000D_
  font-size: 30px;_x000D_
  display: inline-block;_x000D_
}_x000D_
.carosel-control-left {_x000D_
  left: 15px;_x000D_
}_x000D_
.carosel-control-right {_x000D_
  right: 15px;_x000D_
}_x000D_
.carosel-control:active,_x000D_
.carosel-control:hover {_x000D_
  text-decoration: none;_x000D_
  color: rgba(0, 0, 0, 0.8);_x000D_
}
_x000D_
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>_x000D_
<div class="carosel" id="carosel1">_x000D_
  <a class="carosel-control carosel-control-left glyphicon glyphicon-chevron-left" href="#"></a>_x000D_
  <div class="carosel-inner">_x000D_
    <img class="carosel-item" src="http://placehold.it/500/bbbbbb/fff&amp;text=1" />_x000D_
    <img class="carosel-item" src="http://placehold.it/500/CCCCCC&amp;text=2" />_x000D_
    <img class="carosel-item" src="http://placehold.it/500/eeeeee&amp;text=3" />_x000D_
    <img class="carosel-item" src="http://placehold.it/500/f4f4f4&amp;text=4" />_x000D_
    <img class="carosel-item" src="http://placehold.it/500/fcfcfc/333&amp;text=5" />_x000D_
    <img class="carosel-item" src="http://placehold.it/500/f477f4/fff&amp;text=6" />_x000D_
  </div>_x000D_
  <a class="carosel-control carosel-control-right glyphicon glyphicon-chevron-right" href="#"></a>_x000D_
</div>_x000D_
<div class="carosel" id="carosel2">_x000D_
  <a class="carosel-control carosel-control-left glyphicon glyphicon-chevron-left" href="#"></a>_x000D_
  <div class="carosel-inner">_x000D_
    <img class="carosel-item" src="http://placehold.it/500/bbbbbb/fff&amp;text=1" />_x000D_
    <img class="carosel-item" src="http://placehold.it/500/CCCCCC&amp;text=2" />_x000D_
    <img class="carosel-item" src="http://placehold.it/500/eeeeee&amp;text=3" />_x000D_
    <img class="carosel-item" src="http://placehold.it/500/f4f4f4&amp;text=4" />_x000D_
    <img class="carosel-item" src="http://placehold.it/500/fcfcfc/333&amp;text=5" />_x000D_
    <img class="carosel-item" src="http://placehold.it/500/f477f4/fff&amp;text=6" />_x000D_
  </div>_x000D_
  <a class="carosel-control carosel-control-right glyphicon glyphicon-chevron-right" href="#"></a>_x000D_
</div>
_x000D_
_x000D_
_x000D_

The term 'ng' is not recognized as the name of a cmdlet

In the "Environment Variables"

In the "System variables" section

In the "Path" variable and before "C:\Program Files (x86)\nodejs\" add => "%AppData%\npm"

Service will not start: error 1067: the process terminated unexpectedly

I had this error, I looked into a log file C:\...\mysql\data\VM-IIS-Server.err and found this

2016-06-07 17:56:07 160c  InnoDB: Error: unable to create temporary file; errno: 2
2016-06-07 17:56:07 3392 [ERROR] Plugin 'InnoDB' init function returned error.
2016-06-07 17:56:07 3392 [ERROR] Plugin 'InnoDB' registration as a STORAGE ENGINE failed.
2016-06-07 17:56:07 3392 [ERROR] Unknown/unsupported storage engine: InnoDB
2016-06-07 17:56:07 3392 [ERROR] Aborting

The first line says "unable to create temporary file", it sounds like "insufficient privileges", first I tried to give access to mysql folder for my current user - no effect, then after some wandering around I came up to control panel->Administration->Services->Right Clicked MysqlService->Properties->Log On, switched to "This account", entered my username/password, clicked OK, and it woked!

How does Go update third-party packages?

go get will install the package in the first directory listed at GOPATH (an environment variable which might contain a colon separated list of directories). You can use go get -u to update existing packages.

You can also use go get -u all to update all packages in your GOPATH

For larger projects, it might be reasonable to create different GOPATHs for each project, so that updating a library in project A wont cause issues in project B.

Type go help gopath to find out more about the GOPATH environment variable.

Postgres Error: More than one row returned by a subquery used as an expression

USE LIMIT 1 - so It will return only 1 row. Example

customerId- (select id from enumeration where enumerations.name = 'Ready To Invoice' limit 1)

error_reporting(E_ALL) does not produce error

That error is a parse error. The parser is throwing it while going through the code, trying to understand it. No code is being executed yet in the parsing stage. Because of that it hasn't yet executed the error_reporting line, therefore the error reporting settings aren't changed yet.

You cannot change error reporting settings (or really, do anything) in a file with syntax errors.

In R, how to find the standard error of the mean?

more generally, for standard errors on any other parameter, you can use the boot package for bootstrap simulations (or write them on your own)

React won't load local images

src={"/images/resto.png"}

Using of src attribute in this way means, your image will be loaded from the absolute path "/images/resto.png" for your site. Images directory should be located at the root of your site. Example: http://www.example.com/images/resto.png

MAC addresses in JavaScript

If this is for an intranet application and all of the clients use DHCP, you can query the DHCP server for the MAC address for a given IP address.

What in the world are Spring beans?

A Bean is a POJO(Plain Old Java Object), which is managed by the spring container.

Spring containers create only one instance of the bean by default. ?This bean it is cached in memory so all requests for the bean will return a shared reference to the same bean.

The @Bean annotation returns an object that spring registers as a bean in application context.?The logic inside the method is responsible for creating the instance.

When do we use @Bean annotation?

When automatic configuration is not an option. For example when we want to wire components from a third party library, because the source code is not available so we cannot annotate the classes with @Component.

A Real time scenario could be that someone wants to connect to Amazon S3 bucket. Because the source is not available he would have to create a @bean.

@Bean
public AmazonS3 awsS3Client() {
    BasicAWSCredentials awsCreds = new BasicAWSCredentials(awsKeyId, accessKey);
    return AmazonS3ClientBuilder.standard().withRegion(Regions.fromName(region))
            .withCredentials(new AWSStaticCredentialsProvider(awsCreds)).build();
}

Source for the code above -> https://www.devglan.com/spring-mvc/aws-s3-java

Because I mentioned @Component Annotation above.

@Component Indicates that an annotated class is a "component". Such classes are considered as candidates for auto-detection when using annotation-based configuration and class path scanning.

Component annotation registers the class as a single bean.

How to open a txt file and read numbers in Java

Read file, parse each line into an integer and store into a list:

List<Integer> list = new ArrayList<Integer>();
File file = new File("file.txt");
BufferedReader reader = null;

try {
    reader = new BufferedReader(new FileReader(file));
    String text = null;

    while ((text = reader.readLine()) != null) {
        list.add(Integer.parseInt(text));
    }
} catch (FileNotFoundException e) {
    e.printStackTrace();
} catch (IOException e) {
    e.printStackTrace();
} finally {
    try {
        if (reader != null) {
            reader.close();
        }
    } catch (IOException e) {
    }
}

//print out the list
System.out.println(list);

Regular Expression to match valid dates

Regex was not meant to validate number ranges(this number must be from 1 to 5 when the number preceding it happens to be a 2 and the number preceding that happens to be below 6). Just look for the pattern of placement of numbers in regex. If you need to validate is qualities of a date, put it in a date object js/c#/vb, and interogate the numbers there.

Bootstrap tab activation with JQuery

Add an id attribute to a html tag

<ul class="nav nav-tabs">
    <li><a href="#aaa" data-toggle="tab" id="tab_aaa">AAA</a></li>
    <li><a href="#bbb" data-toggle="tab" id="tab_bbb">BBB</a></li>
    <li><a href="#ccc" data-toggle="tab" id="tab_ccc">CCC</a></li>
</ul>
<div class="tab-content" id="tabs">
    <div class="tab-pane" id="aaa">...Content...</div>
    <div class="tab-pane" id="bbb">...Content...</div>
    <div class="tab-pane" id="ccc">...Content...</div>
</div>

Then using JQuery

$("#tab_aaa").tab('show');

What does a question mark represent in SQL queries?

The ? is to allow Parameterized Query. These parameterized query is to allow type-specific value when replacing the ? with their respective value.

That's all to it.

Here's a reason of why it's better to use Parameterized Query. Basically, it's easier to read and debug.

Linq: GroupBy, Sum and Count

sometimes you need to select some fields by FirstOrDefault() or singleOrDefault() you can use the below query:

List<ResultLine> result = Lines
    .GroupBy(l => l.ProductCode)
    .Select(cl => new Models.ResultLine
            {
                ProductName = cl.select(x=>x.Name).FirstOrDefault(),
                Quantity = cl.Count().ToString(),
                Price = cl.Sum(c => c.Price).ToString(),
            }).ToList();

Apply formula to the entire column

Found another solution:

  • Apply the formula to the first 3 or 4 cells of the column
  • Ctrl + C the formula in one of the last rows (if you copy the first line it won't work)
  • Click on the column header to select the whole column
  • Press Ctrl + V to paste it in all cells bellow

How to set Angular 4 background image?

This works for me:

put this in your markup:

<div class="panel panel-default" [ngStyle]="{'background-image': getUrl()}">

then in component:

getUrl()
{
  return "url('http://estringsoftware.com/wp-content/uploads/2017/07/estring-header-lowsat.jpg')";
}

Choosing a jQuery datagrid plugin?

You should look here: https://stackoverflow.com/questions/159025/jquery-grid-recommendations

Update

The link above takes to a question that was closed and then deleted. Here are the original suggestions that were on the most voted answer:

How to convert Set<String> to String[]?

Set<String> stringSet= new HashSet<>();
String[] s = (String[])stringSet.toArray();

How to check for an empty object in an AngularJS view

This will do the object empty checking:

<div ng-if="isEmpty(card)">Object Empty!</div>


$scope.isEmpty = function(obj){
  return Object.keys(obj).length == 0;
}

Error: Could not find or load main class in intelliJ IDE

I have tried all the hacks suggested here - to no avail. At the end I have simply created a new Maven application and manually copied into it - one by one - the pom.xml and the java files and resources. It all works now. I am new to IntelliJ and totally unimpressed but how easy it is to get it into an unstable state.

Java default constructor

General terminology is that if you don't provide any constructor in your object a no argument constructor is automatically placed which is called default constructor.

If you do define a constructor same as the one which would be placed if you don't provide any it is generally termed as no arguments constructor.Just a convention though as some programmer prefer to call this explicitly defined no arguments constructor as default constructor. But if we go by naming if we are explicitly defining one than it does not make it default.

As per the docs

If a class contains no constructor declarations, then a default constructor with no formal parameters and no throws clause is implicitly declared.

Example

public class Dog
{
}

will automatically be modified(by adding default constructor) as follows

public class Dog{
    public Dog() {

    }
} 

and when you create it's object

 Dog myDog = new Dog();

this default constructor is invoked.

How can I create an array/list of dictionaries in python?

Dictionary:

dict = {'a':'a','b':'b','c':'c'}

array of dictionary

arr = (dict,dict,dict)
arr
({'a': 'a', 'c': 'c', 'b': 'b'}, {'a': 'a', 'c': 'c', 'b': 'b'}, {'a': 'a', 'c': 'c', 'b': 'b'})

How to push a new folder (containing other folders and files) to an existing git repo?

You need to git add my_project to stage your new folder. Then git add my_project/* to stage its contents. Then commit what you've staged using git commit and finally push your changes back to the source using git push origin master (I'm assuming you wish to push to the master branch).

How to query for today's date and 7 days before data?

Try this way:

select * from tab
where DateCol between DateAdd(DD,-7,GETDATE() ) and GETDATE() 

Unable to capture screenshot. Prevented by security policy. Galaxy S6. Android 6.0

Go to Phone Settings --> Developer Options --> Simulate Secondary Displays and turn it to None. If you don't see Developer Options in the settings menu (it should be at the bottom, go Settings ==> About phone and tap on the Build number a lot of times)

Confusing error in R: Error in scan(file, what, nmax, sep, dec, quote, skip, nlines, na.strings, : line 1 did not have 42 elements)

To read characters try

scan("/PathTo/file.csv", "")

If you're reading numeric values, then just use

scan("/PathTo/file.csv")

scan by default will use white space as separator. The type of the second arg defines 'what' to read (defaults to double()).

How to run a single RSpec test?

Not sure how long this has bee available but there is an Rspec configuration for run filtering - so now you can add this to your spec_helper.rb:

RSpec.configure do |config|
  config.filter_run_when_matching :focus
end

And then add a focus tag to the it, context or describe to run only that block:

it 'runs a test', :focus do
  ...test code
end

RSpec documentation:

https://www.rubydoc.info/github/rspec/rspec-core/RSpec/Core/Configuration#filter_run_when_matching-instance_method

How to set the max value and min value of <input> in html5 by javascript or jquery?

Try this

 $(function(){
   $("input[type='number']").prop('min',1);
   $("input[type='number']").prop('max',10);
});

Demo

Hide the browse button on a input type=file

You may just without making the element hidden, simply make it transparent by making its opacity to 0.

Making the input file hidden will make it STOP working. So DON'T DO THAT..

Here you can find an example for a transparent Browse operation;

Spring,Request method 'POST' not supported

Try this

@RequestMapping(value = "proffessional", method = RequestMethod.POST)
    public @ResponseBody
    String forgotPassword(@ModelAttribute("PROFESSIONAL") UserProfessionalForm professionalForm,
            BindingResult result, Model model) {

        UserProfileVO userProfileVO = new UserProfileVO();
        userProfileVO.setUser(sessionData.getUser());
        userService.saveUserProfile(userProfileVO);
        model.addAttribute("professional", professionalForm);
        return "Your Professional Details Updated";
    }

How to fix height of TR?

Setting the td height to less than the natural height of its content

Since table cells want to be at least big enough to encase their content, if the content has no apparent height, the cells can be arbitrarily resized.

By resizing the cells, we can control the row height.

One way to do this, is to set the content with an absolute position within the relative cell, and set the height of the cell, and the left and top of the content.

_x000D_
_x000D_
table {_x000D_
  width: 100%;_x000D_
}_x000D_
td {_x000D_
  border: 1px solid #999;_x000D_
}_x000D_
.set-height td {_x000D_
  position: relative;_x000D_
  overflow: hidden;_x000D_
  height: 3em;_x000D_
}_x000D_
.set-height p {_x000D_
  position: absolute;_x000D_
  margin: 0;_x000D_
  top: 0;_x000D_
}_x000D_
/* table layout fixed */_x000D_
.layout-fixed {_x000D_
  table-layout: fixed;_x000D_
}_x000D_
/* td width */_x000D_
.td-width td:first-child {_x000D_
  width: 33%;_x000D_
}
_x000D_
<table><tbody>_x000D_
  <tr class="set-height">_x000D_
    <td><p>Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.</p></td>_x000D_
    <td>Foo</td></tr><tr><td>Bar</td><td>Baz</td></tr><tr><td>Qux</td>_x000D_
    <td>Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.</td>_x000D_
  </tr>_x000D_
</tbody></table>_x000D_
<h3>With <code>table-layout: fixed</code> applied:</h3>_x000D_
<table class="layout-fixed"><tbody>_x000D_
  <tr class="set-height">_x000D_
    <td><p>Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.</p></td>_x000D_
    <td>Foo</td></tr><tr><td>Bar</td><td>Baz</td></tr><tr><td>Qux</td>_x000D_
    <td>Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.</td>_x000D_
  </tr>_x000D_
</tbody></table>_x000D_
<h3>With <code>&lt;td&gt; width</code> applied:</h3>_x000D_
<table class="td-width"><tbody>_x000D_
  <tr class="set-height">_x000D_
    <td><p>Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.</p></td>_x000D_
    <td>Foo</td></tr><tr><td>Bar</td><td>Baz</td></tr><tr><td>Qux</td>_x000D_
    <td>Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.</td>_x000D_
  </tr>_x000D_
</tbody></table>
_x000D_
_x000D_
_x000D_

The table-layout property

The second table in the snippet above has table-layout: fixed applied, which causes cells to be given equal width, regardless of their content, within the parent.

According to caniuse.com, there are no significant compatibility issues regarding the use of table-layout as of Sept 12, 2019.

Or simply apply width to specific cells as in the third table.

These methods allow the cell containing the effectively sizeless content created by applying position: absolute to be given some arbitrary girth.

Much more simply...

I really should have thought of this from the start; we can manipulate block level table cell content in all the usual ways, and without completely destroying the content's natural size with position: absolute, we can leave the table to figure out what the width should be.

_x000D_
_x000D_
table {_x000D_
  width: 100%;_x000D_
}_x000D_
td {_x000D_
  border: 1px solid #999;_x000D_
}_x000D_
table p {_x000D_
  margin: 0;_x000D_
}_x000D_
.cap-height p {_x000D_
  max-height: 3em;_x000D_
  overflow: hidden;_x000D_
}
_x000D_
<table><tbody>_x000D_
  <tr class="cap-height">_x000D_
    <td><p>Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.</p></td>_x000D_
    <td>Foo</td>_x000D_
  </tr>_x000D_
  <tr class="cap-height">_x000D_
    <td><p>Bar</p></td>_x000D_
    <td>Baz</td>_x000D_
  </tr>_x000D_
  <tr>_x000D_
    <td>Qux</td>_x000D_
    <td><p>Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.</p></td>_x000D_
  </tr>_x000D_
</tbody></table>
_x000D_
_x000D_
_x000D_

Is it possible to make desktop GUI application in .NET Core?

tl;dr - I'm not sure that it would be possible for the .NET Core developers to supply a cross-platform GUI framework.

I feel like expecting a cross-platform GUI framework to be bundled into the official tooling (especially an old version of the tooling - you mention that you're running Visual Studio 2015 update 3) for an early version of .NET Core is a little premature.

GUI frameworks are really quite heavy, and dependent on the hardware abstractions already present on the host machine. On Windows, there is generally a single window manager (WM) and desktop environment (DE) used by most users, but on the many different distributions of Linux which are supported, there are any number of possible WMs and DEs - granted most users will either be using X-Server or Wayland in combination with KDE, GNOME or Xfce. But no Linux installation ever is the same.

The fact that the open source community can't really settle on a "standard" setup for a VM and DE means that it would be pretty difficult for the .NET Core developers to create a GUI framework which would work across all platforms and combinations of DEs and WMs.

A lot of folks here have some great suggestions (from use ASP.NET Core to builds a Web application and use a browser to listing a bunch of cross-platform frameworks). If you take a look at some of the mentioned cross platform GUI frameworks listed, you'll see how heavy they are.

However, there is light at the end of the tunnel as Miguel de Icaza showed off Xamarin running naively on Linux and macOS at .NET Conf this year (2017, if you're reading this in the future), so it might be worth trying that when it's ready.

(But you'll need to upgrade from Visual Studio 2015 to Visual Studio 2017 to access the .NET Core 2.0 features.)

Positioning background image, adding padding

In case anyone else needs to add padding to something with background-image and background-size: contain or cover, I used the following which is a nice way of doing it. You can replace the border-width with 10% or 2vw or whatever you like.

.bg-image {
    background: url("/image/logo.png") no-repeat center #ffffff / contain;
    border: inset 10px transparent;
    box-sizing: border-box;
}

This means you don't have to define a width.

AngularJS format JSON string output

If you are looking to render JSON as HTML and it can be collapsed/opened, you can use this directive that I just made to render it nicely:

https://github.com/mohsen1/json-formatter/

enter image description here

Decompile Python 2.7 .pyc

In case anyone is still struggling with this, as I was all morning today, I have found a solution that works for me:

Uncompyle

Installation instructions:

git clone https://github.com/gstarnberger/uncompyle.git
cd uncompyle/
sudo ./setup.py install

Once the program is installed (note: it will be installed to your system-wide-accessible Python packages, so it should be in your $PATH), you can recover your Python files like so:

uncompyler.py thank_goodness_this_still_exists.pyc > recovered_file.py

The decompiler adds some noise mostly in the form of comments, however I've found it to be surprisingly clean and faithful to my original code. You will have to remove a little line of text beginning with +++ near the end of the recovered file to be able to run your code.

Tomcat 7 is not running on browser(http://localhost:8080/ )

You can run below commands.

 ./catalina.sh run

Note: Make sure the port 8080 is open. If not, kill the process that is using 8080 port using sudo kill -9 $(sudo lsof -t -i:8080)

How to use a variable from a cursor in the select statement of another cursor in pl/sql

Use alter session set current_schema = <username>, in your case as an execute immediate.

See Oracle's documentation for further information.

In your case, that would probably boil down to (untested)

DECLARE

   CURSOR client_cur IS
     SELECT  distinct username 
       from all_users 
      where length(username) = 3;

   -- client cursor 
   CURSOR emails_cur IS
   SELECT id, name 
     FROM org;

BEGIN

   FOR client IN client_cur LOOP

   -- ****
      execute immediate 
     'alter session set current_schema = ' || client.username;
   -- ****

      FOR email_rec in client_cur LOOP

         dbms_output.put_line(
             'Org id is ' || email_rec.id || 
             ' org nam '  || email_rec.name);

      END LOOP;

  END LOOP;
END;
/

How to access data/data folder in Android device?

you can copy this db file to somewhere in eclipse explorer (eg:sdcard or PC),and you can use sqlite to access and update this db file .

Conditional Replace Pandas

Try this:

df.my_channel = df.my_channel.where(df.my_channel <= 20000, other= 0)

or

df.my_channel = df.my_channel.mask(df.my_channel > 20000, other= 0)

C#: how to get first char of a string?

I think you are looking for this MyString.ToCharArray()[0]

:)

But you can use MyString[0] too.

How to get the Full file path from URI

I had a hard time trying to figure this out on Xamarin. From the suggestions above I came up with this solution.

private string getRealPathFromURI(Android.Net.Uri contentUri)
{
    string filename = "";
    string thepath = "";
    Android.Net.Uri filePathUri;
    ICursor cursor = this.ContentResolver.Query(contentUri, null, null, null, null);

    if (cursor.MoveToFirst())
    {
        int column_index = cursor.GetColumnIndex(MediaStore.Images.Media.InterfaceConsts.Data);//Instead of "MediaStore.Images.Media.DATA" can be used "_data"
        filePathUri = Android.Net.Uri.Parse(cursor.GetString(column_index));
        filename = filePathUri.LastPathSegment;
        thepath = filePathUri.Path;
    }

    return thepath;
}

jquery ui Dialog: cannot call methods on dialog prior to initialization

In my case the problem was that I had called $("#divDialog").removeData(); as part of resetting my forms data within the dialog.

This resulted in me wiping out a data structure named uiDialog which meant that the dialog had to reinitialize.

I replaced .removeData() with more specific deletes and everything started working again.

REST API 404: Bad URI, or Missing Resource?

404 Not Found technically means that uri does not currently map to a resource. In your example, I interpret a request to http://mywebsite/api/user/13 that returns a 404 to imply that this url was never mapped to a resource. To the client, that should be the end of conversation.

To address concerns with ambiguity, you can enhance your API by providing other response codes. For example, suppose you want to allow clients to issue GET requests the url http://mywebsite/api/user/13, you want to communicate that clients should use the canonical url http://mywebsite/restapi/user/13. In that case, you may want to consider issuing a permanent redirect by returning a 301 Moved Permanently and supply the canonical url in the Location header of the response. This tells the client that for future requests they should use the canonical url.

How to send parameters with jquery $.get()

I got this working : -

$.get('api.php', 'client=mikescafe', function(data) {
...
});

It sends via get the string ?client=mikescafe then collect this variable in api.php, and use it in your mysql statement.

C/C++ check if one bit is set in, i.e. int variable

Why not use something as simple as this?

uint8_t status = 255;
cout << "binary: ";

for (int i=((sizeof(status)*8)-1); i>-1; i--)
{
  if ((status & (1 << i)))
  {
    cout << "1";
  } 
  else
  {
    cout << "0";
  }
}

OUTPUT: binary: 11111111

How to read a text file from server using JavaScript?

It looks like XMLHttpRequest has been replaced by the Fetch API. Google published a good introduction that includes this example doing what you want:

fetch('./api/some.json')
  .then(
    function(response) {
      if (response.status !== 200) {
        console.log('Looks like there was a problem. Status Code: ' +
          response.status);
        return;
      }

      // Examine the text in the response
      response.json().then(function(data) {
        console.log(data);
      });
    }
  )
  .catch(function(err) {
    console.log('Fetch Error :-S', err);
  });

However, you probably want to call response.text() instead of response.json().

Unresolved reference issue in PyCharm

I was also using a virtual environment like Dan above, however I was able to add an interpreter in the existing environment, therefore not needing to inherit global site packages and therefore undo what a virtual environment is trying to achieve.

SQL Server 2008 R2 Express permissions -- cannot create database or modify users

Coming late to the party, but I found this fantastic step-by-step guide on getting control of your SQLExpress instance if you don't have your sa password. I used this process to not only reset my sa password, but I also added my domain account to all the available server roles. I can now create databases, alter logins, do bulk operations, backups/restores, etc using my normal login.

To summarize, you use SQL Server Configuration Manager to put your instance into single-user mode. This elevates you to sysadmin when you connect, allowing you the ability to set everything up.

Edit: I've copied the steps below - kudos to the original author of the link above.

  1. Log on to the computer as an Administrator (or Any user with administrator privileges)
  2. Open "SQL Server Configuration Manager"
  3. Click "SQL Server Services" on the left pane
  4. Stop "SQL Server" and "SQL Server Agent" instance on the right pane if it is running
  5. Run the SQL Express in single-user mode by right clicking on "SQL Server" instance -> Properties (on the right pane of SQL Server Configuration Manager).
  6. Click Advanced Tab, and look for "Startup Parameters". Change the "Startup Parameters" so that the new value will be -m; (without the <>) example: from: -dc:\Program Files\Microsoft SQL.............(til end of string) to: -m;-dc:\Program Files\Microsoft SQL.............(til end of string)
  7. Start the SQL Server
  8. Open your MS SQL Server Management Studio and log on to the SQL server with "Windows Authentication" as the authentication mode. Since we have the SQL Server running on single user mode, and you are logged on to the computer with Administrator privileges, you will have a "sysadmin" access to the database.
  9. Expand the "Security" node on MS SQL Server Management Studio on the left pane
  10. Expand the "Logins" node
  11. Double-click the 'sa' login
  12. Change the password by entering a complex password if "Enforce password policy" is ticked, otherwise, just enter any password.
  13. Make sure that "sa" Account is "enabled" by clicking on Status on the left pane. Set the radio box under "Login" to "Enabled"
  14. Click "OK"
  15. Back on the main window of MS SQL Server Management Studio, verify if SQL Server Authentication is used by right clicking on the top most node in the left pane (usually ".\SQLEXPRESS (SQL Server )") and choosing properties.
  16. Click "Security" in the left pane and ensure that "SQL Server and Windows Authentication mode" is the one selected under "Server authentication"
  17. Click "OK"
  18. Disconnect from MS SQL Server Management Studio
  19. Open "Sql Server Configuration Manager" again and stop the SQL Server instance.
  20. Right-click on SQL Server instance and click on "Advanced" tab. Again look for "Startup Parameters" and remove the "-m;" that you added earlier.
  21. Click "OK" and start the SQL Server Instance again
  22. You should now be able to log on as "sa" using the new password that you have set in step 12.

How to define static property in TypeScript interface

I implemented a solution like Kamil Szot's, and it has an undesired effect. I have not enough reputation to post this as a comment, so I post it here in case someone is trying that solution and reads this.

The solution is:

interface MyInterface {
    Name: string;
}

const MyClass = class {
    static Name: string;
};

However, using a class expression doesn't allow me to use MyClass as a type. If I write something like:

const myInstance: MyClass;

myInstance turns out to be of type any, and my editor shows the following error:

'MyClass' refers to a value, but is being used as a type here. Did you mean 'typeof MyClass'?ts(2749)

I end up losing a more important typing than the one I wanted to achieve with the interface for the static part of the class.

Val's solution using a decorator avoids this pitfall.

Is the server running on host "localhost" (::1) and accepting TCP/IP connections on port 5432?

I encountered a similar problem when I was trying to connect my Django application to PostgreSQL database.

I wrote my Dockerfile with instructions to setup the Django project followed by instructions to install PostgreSQL and run Django server in my docker-compose.yml.

I defined two services in my docker-compose-yml.

services:
  postgres:
    image: "postgres:latest"
    environment:
      - POSTGRES_DB=abc
      - POSTGRES_USER=abc
      - POSTGRES_PASSWORD=abc
    volumes:
      - pg_data:/var/lib/postgresql/data/
  django:
    build: .
    command: python /code/manage.py runserver 0.0.0.0:8004
    volumes:
      - .:/app
    ports:
      - 8004:8004
    depends_on:
      - postgres 

Unfortunately whenever I used to run docker-compose up then same err. used to pop up.

And this is how my database was defined in Django settings.py.

DATABASES = {
    'default': {
        'ENGINE': 'django.db.backends.postgresql',
        'NAME': 'abc',
        'USER': 'abc',
        'PASSWORD': 'abc',
        'HOST': '127.0.0.1',
        'PORT': '5432',
        'OPTIONS': {
            'client_encoding': 'UTF8',
        },
    }
} 

So, In the end I made use of docker-compose networking which means if I change the host of my database to postgres which is defined as a service in docker-compose.yml will do the wonders.

So, Replacing 'HOST': '127.0.0.1' => 'HOST': 'postgres' did wonders for me.

After replacement this is how your Database config in settings.py will look like.

DATABASES = {
        'default': {
            'ENGINE': 'django.db.backends.postgresql',
            'NAME': 'abc',
            'USER': 'abc',
            'PASSWORD': 'abc',
            'HOST': 'postgres',
            'PORT': '5432',
            'OPTIONS': {
                'client_encoding': 'UTF8',
            },
        }
    } 

Remove lines that contain certain string

Regex is a little quicker than the accepted answer (for my 23 MB test file) that I used. But there isn't a lot in it.

import re

bad_words = ['bad', 'naughty']

regex = f"^.*(:{'|'.join(bad_words)}).*\n"
subst = ""

with open('oldfile.txt') as oldfile:
    lines = oldfile.read()

result = re.sub(regex, subst, lines, re.MULTILINE) 

with open('newfile.txt', 'w') as newfile:
    newfile.write(result)

enter image description here

How to get a value from the last inserted row?

With PostgreSQL you can do it via the RETURNING keyword:

PostgresSQL - RETURNING

INSERT INTO mytable( field_1, field_2,... )
VALUES ( value_1, value_2 ) RETURNING anyfield

It will return the value of "anyfield". "anyfield" may be a sequence or not.

To use it with JDBC, do:

ResultSet rs = statement.executeQuery("INSERT ... RETURNING ID");
rs.next();
rs.getInt(1);

What is the purpose of Node.js module.exports and how do you use it?

the refer link is like this:

exports = module.exports = function(){
    //....
}

the properties of exports or module.exports ,such as functions or variables , will be exposed outside

there is something you must pay more attention : don't override exports .

why ?

because exports just the reference of module.exports , you can add the properties onto the exports ,but if you override the exports , the reference link will be broken .

good example :

exports.name = 'william';

exports.getName = function(){
   console.log(this.name);
}

bad example :

exports = 'william';

exports = function(){
     //...
}

If you just want to exposed only one function or variable , like this:

// test.js
var name = 'william';

module.exports = function(){
    console.log(name);
}   

// index.js
var test = require('./test');
test();

this module only exposed one function and the property of name is private for the outside .

click() event is calling twice in jquery

I solved this problem by change the element type. instead of button I place input, and this problem don't occur more.

instesd of:

<button onclick="doSomthing()">click me</button>

replace with:

<input onclick="doSomthing()" value="click me">

How do I use the lines of a file as arguments of a command?

Here's how I pass contents of a file as an argument to a command:

./foo --bar "$(cat ./bar.txt)"

How to use "raise" keyword in Python

raise without any arguments is a special use of python syntax. It means get the exception and re-raise it. If this usage it could have been called reraise.

    raise

From The Python Language Reference:

If no expressions are present, raise re-raises the last exception that was active in the current scope.

If raise is used alone without any argument is strictly used for reraise-ing. If done in the situation that is not at a reraise of another exception, the following error is shown: RuntimeError: No active exception to reraise

How to change text color of cmd with windows batch script every 1 second

@echo off
set NUM=0 1 2 3 4 5 6 7 8 9 A B C D E F 31 32 33 34 35 36 37 41 42 43 44 45 46 90 91 92 93 94 95 96 97 100 101 102 103 104 105 106 107 
for %%x in (%NUM%) do ( 
    for %%y in (%NUM%) do (
        color %%x%%y
cls
echo Himel Sarkar
        timeout 1 >nul
    )
)

pause

SQL Error: ORA-00936: missing expression

Your statement is calling SELECT and WHERE but does not specify which TABLE or record set you would like to SELECT FROM.

SELECT DISTINCT Description, Date as treatmentDate
FROM (TABLE_NAME or SUBQUERY)<br> --This is missing from your query.
WHERE doothey.Patient P, doothey.Account A, doothey.AccountLine AL, doothey.Item.I
AND P.PatientID = A.PatientID
AND A.AccountNo = AL.AccountNo
AND AL.ItemNo = I.ItemNo
AND (p.FamilyName = 'Stange' AND p.GivenName = 'Jessie');

window.history.pushState refreshing the browser

As others have suggested, you are not clearly explaining your problem, what you are trying to do, or what your expectations are as to what this function is actually supposed to do.

If I have understood correctly, then you are expecting this function to refresh the page for you (you actually use the term "reloads the browser").

But this function is not intended to reload the browser.

All the function does, is to add (push) a new "state" onto the browser history, so that in future, the user will be able to return to this state that the web-page is now in.

Normally, this is used in conjunction with AJAX calls (which refresh only a part of the page).

For example, if a user does a search "CATS" in one of your search boxes, and the results of the search (presumably cute pictures of cats) are loaded back via AJAX, into the lower-right of your page -- then your page state will not be changed. In other words, in the near future, when the user decides that he wants to go back to his search for "CATS", he won't be able to, because the state doesn't exist in his history. He will only be able to click back to your blank search box.

Hence the need for the function

history.pushState({},"Results for `Cats`",'url.html?s=cats');

It is intended as a way to allow the programmer to specifically define his search into the user's history trail. That's all it is intended to do.

When the function is working properly, the only thing you should expect to see, is the address in your browser's address-bar change to whatever you specify in your URL.

If you already understand this, then sorry for this long preamble. But it sounds from the way you pose the question, that you have not.

As an aside, I have also found some contradictions between the way that the function is described in the documentation, and the way it works in reality. I find that it is not a good idea to use blank or empty values as parameters.

See my answer to this SO question. So I would recommend putting a description in your second parameter. From memory, this is the description that the user sees in the drop-down, when he clicks-and-holds his mouse over "back" button.

Calculating sum of repeated elements in AngularJS ng-repeat

In Template

<td>Total: {{ getTotal() }}</td>

In Controller

$scope.getTotal = function(){
    var total = 0;
    for(var i = 0; i < $scope.cart.products.length; i++){
        var product = $scope.cart.products[i];
        total += (product.price * product.quantity);
    }
    return total;
}

Jquery, Clear / Empty all contents of tbody element?

you can use the remove() function of the example below and build table again with table head, and table body

$("#table_id  thead").remove();
$("#table_id  tbody").remove();

How to reduce a huge excel file

If your file is just text, the best solution is to save each worksheet as .csv and then reimport it into excel - it takes a bit more work, but I reduced a 20MB file to 43KB.

How Does Modulus Divison Work

27 % 16 = 11

You can interpret it this way:

16 goes 1 time into 27 before passing it.

16 * 2 = 32.

So you could say that 16 goes one time in 27 with a remainder of 11.

In fact,

16 + 11 = 27

An other exemple:

20 % 3 = 2

Well 3 goes 6 times into 20 before passing it.

3 * 6 = 18

To add-up to 20 we need 2 so the remainder of the modulus expression is 2.

Convert UNIX epoch to Date object

With library(lubridate), numeric representations of date and time saved as the number of seconds since 1970-01-01 00:00:00 UTC, can be coerced into dates with as_datetime():

lubridate::as_datetime(1352068320)

[1] "2012-11-04 22:32:00 UTC"

Use xml.etree.ElementTree to print nicely formatted xml files

You can use the function toprettyxml() from xml.dom.minidom in order to do that:

def prettify(elem):
    """Return a pretty-printed XML string for the Element.
    """
    rough_string = ElementTree.tostring(elem, 'utf-8')
    reparsed = minidom.parseString(rough_string)
    return reparsed.toprettyxml(indent="\t")

The idea is to print your Element in a string, parse it using minidom and convert it again in XML using the toprettyxml function.

Source: http://pymotw.com/2/xml/etree/ElementTree/create.html

Difference between DataFrame, Dataset, and RDD in Spark

Spark RDD (resilient distributed dataset) :

RDD is the core data abstraction API and is available since very first release of Spark (Spark 1.0). It is a lower-level API for manipulating distributed collection of data. The RDD APIs exposes some extremely useful methods which can be used to get very tight control over underlying physical data structure. It is an immutable (read only) collection of partitioned data distributed on different machines. RDD enables in-memory computation on large clusters to speed up big data processing in a fault tolerant manner. To enable fault tolerance, RDD uses DAG (Directed Acyclic Graph) which consists of a set of vertices and edges. The vertices and edges in DAG represent the RDD and the operation to be applied on that RDD respectively. The transformations defined on RDD are lazy and executes only when an action is called

Spark DataFrame :

Spark 1.3 introduced two new data abstraction APIs – DataFrame and DataSet. The DataFrame APIs organizes the data into named columns like a table in relational database. It enables programmers to define schema on a distributed collection of data. Each row in a DataFrame is of object type row. Like an SQL table, each column must have same number of rows in a DataFrame. In short, DataFrame is lazily evaluated plan which specifies the operations needs to be performed on the distributed collection of the data. DataFrame is also an immutable collection.

Spark DataSet :

As an extension to the DataFrame APIs, Spark 1.3 also introduced DataSet APIs which provides strictly typed and object-oriented programming interface in Spark. It is immutable, type-safe collection of distributed data. Like DataFrame, DataSet APIs also uses Catalyst engine in order to enable execution optimization. DataSet is an extension to the DataFrame APIs.

Other Differences -

enter image description here

Changing the CommandTimeout in SQL Management studio

If you are getting a timeout while on the table designer, change the "Transaction time-out after" value under Tools --> Options --> Designers --> Table and Database Designers

This will get rid of this message: "Timeout expired. The timeout period elapsed prior to completion of the operation or the server is not responding."

enter image description here

Colouring plot by factor in R

The col argument in the plot function assign colors automatically to a vector of integers. If you convert iris$Species to numeric, notice you have a vector of 1,2 and 3s So you can apply this as:

plot(iris$Sepal.Length, iris$Sepal.Width, col=as.numeric(iris$Species))

Suppose you want red, blue and green instead of the default colors, then you can simply adjust it:

plot(iris$Sepal.Length, iris$Sepal.Width, col=c('red', 'blue', 'green')[as.numeric(iris$Species)])

You can probably see how to further modify the code above to get any unique combination of colors.

Bootstrap $('#myModal').modal('show') is not working

Most common reason for such problems are

1.If you have defined the jquery library more than once.

<script type="text/javascript" src="//code.jquery.com/jquery-1.11.3.min.js"></script>
<script src="http://maxcdn.bootstrapcdn.com/bootstrap/3.3.6/js/bootstrap.min.js"></script>

    <div class="modal fade" id="myModal" aria-hidden="true">
    ...
    ...
    </div>

<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.12.0/jquery.min.js"></script>

The bootstrap library gets applied to the first jquery library but when you reload the jquery library, the original bootstrap load is lost(Modal function is in bootstrap).

2.Please wrap your JavaScript code inside

$(document).ready(function(){});

3.Please check if the id of the modal is same

as the one you have defined for the component(Also check for duplication's of same id ).

JavaScript: replace last occurrence of text in a string

Old fashioned and big code but efficient as possible:

function replaceLast(origin,text){
    textLenght = text.length;
    originLen = origin.length
    if(textLenght == 0)
        return origin;

    start = originLen-textLenght;
    if(start < 0){
        return origin;
    }
    if(start == 0){
        return "";
    }
    for(i = start; i >= 0; i--){
        k = 0;
        while(origin[i+k] == text[k]){
            k++
            if(k == textLenght)
                break;
        }
        if(k == textLenght)
            break;
    }
    //not founded
    if(k != textLenght)
        return origin;

    //founded and i starts on correct and i+k is the first char after
    end = origin.substring(i+k,originLen);
    if(i == 0)
        return end;
    else{
        start = origin.substring(0,i) 
        return (start + end);
    }
}

SSH to Elastic Beanstalk instance

On mac you can install the cli using brew:

brew install awsebcli

With the command line tool you can then ssh with:

eb ssh environment-name

and also do other operations. This assumes you have added a security group that allows ssh from your ip.

JFrame background image

This is a simple example for adding the background image in a JFrame:

import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
class BackgroundImageJFrame extends JFrame
{
    JButton b1;
    JLabel l1;

    public BackgroundImageJFrame()
    {
        setTitle("Background Color for JFrame");
        setSize(400,400);
        setLocationRelativeTo(null);
        setDefaultCloseOperation(EXIT_ON_CLOSE);
        setVisible(true);

        /*
        One way
        -----------------
        setLayout(new BorderLayout());
        JLabel background=new JLabel(new ImageIcon("C:\\Users\\Computer\\Downloads\\colorful design.png"));
        add(background);
        background.setLayout(new FlowLayout());
        l1=new JLabel("Here is a button");
        b1=new JButton("I am a button");
        background.add(l1);
        background.add(b1);
        */

        // Another way
        setLayout(new BorderLayout());
        setContentPane(new JLabel(new ImageIcon("C:\\Users\\Computer\\Downloads\\colorful design.png")));
        setLayout(new FlowLayout());
        l1=new JLabel("Here is a button");
        b1=new JButton("I am a button");
        add(l1);
        add(b1);
        // Just for refresh :) Not optional!
        setSize(399,399);
        setSize(400,400);
    }

    public static void main(String args[])
    {
        new BackgroundImageJFrame();
    }
} 
  • Click here for more info

What is the size of a pointer?

The size of a pointer is the size required by your system to hold a unique memory address (since a pointer just holds the address it points to)

Is Spring annotation @Controller same as @Service?

No, @Controller is not the same as @Service, although they both are specializations of @Component, making them both candidates for discovery by classpath scanning. The @Service annotation is used in your service layer, and @Controller is for Spring MVC controllers in your presentation layer. A @Controller typically would have a URL mapping and be triggered by a web request.

Copy files on Windows Command Line with Progress

Some interesting timings regarding all these methods. If you have Gigabit connections, you should not use the /z flag or it will kill your connection speed. Robocopy or dism are the only tools that go full speed and show a progress bar. wdscase is for multicasting off a WDS server and might be faster if you are imaging 5+ computers. To get the 1:17 timing, I was maxing out the Gigabit connection at 920Mbps so you won't get that on two connections at once. Also take note that exporting the small wim index out of the larger wim file too longer than just copying the whole thing.

Model  Exe       OS       switches     index    size    time   link speed 
8760w  dism      Win8     /export-wim  index 1  6.27GB  2:21   link 1Gbps
8760w  dism      Win8     /export-wim  index 2  7.92GB  1:29   link 1Gbps
6305   wdsmcast  winpe32  /trans-file  res.RWM  7.92GB  6:54   link 1Gbps
6305   dism      Winpe32  /export-wim  index 1  6.27GB  2:20   link 1Gbps
6305   dism      Winpe32  /export-wim  index 2  7.92GB  1:34   link 1Gbps
6305   copy      Winpe32  /z           Whole    7.92GB  25:48  link 1Gbps
6305   copy      Winpe32  none         Wim      7.92GB  1:17   link 1Gbps
6305   xcopy     Winpe32  /z /j        Wim      7.92GB  23:54  link 1Gbps
6305   xcopy     Winpe32  /j           Wim      7.92GB  1:38   link 1Gbps
6305   VBS.copy  Winpe32               Wim      7.92    1:21   link 1Gbps
6305   robocopy  Winpe32               Wim      7.92    1:17   link 1Gbps

If you don't have robocopy.exe available, why not run it from the network share you are copying your files from? In my case, I prefer to do that so I don't have to rebuild my WinPE boot.wim file every time I want to make a change and then update dozens of flash drives.

Reading column names alone in a csv file

The csv.DictReader object exposes an attribute called fieldnames, and that is what you'd use. Here's example code, followed by input and corresponding output:

import csv
file = "/path/to/file.csv"
with open(file, mode='r', encoding='utf-8') as f:
    reader = csv.DictReader(f, delimiter=',')
    for row in reader:
        print([col + '=' + row[col] for col in reader.fieldnames])

Input file contents:

col0,col1,col2,col3,col4,col5,col6,col7,col8,col9
00,01,02,03,04,05,06,07,08,09
10,11,12,13,14,15,16,17,18,19
20,21,22,23,24,25,26,27,28,29
30,31,32,33,34,35,36,37,38,39
40,41,42,43,44,45,46,47,48,49
50,51,52,53,54,55,56,57,58,59
60,61,62,63,64,65,66,67,68,69
70,71,72,73,74,75,76,77,78,79
80,81,82,83,84,85,86,87,88,89
90,91,92,93,94,95,96,97,98,99

Output of print statements:

['col0=00', 'col1=01', 'col2=02', 'col3=03', 'col4=04', 'col5=05', 'col6=06', 'col7=07', 'col8=08', 'col9=09']
['col0=10', 'col1=11', 'col2=12', 'col3=13', 'col4=14', 'col5=15', 'col6=16', 'col7=17', 'col8=18', 'col9=19']
['col0=20', 'col1=21', 'col2=22', 'col3=23', 'col4=24', 'col5=25', 'col6=26', 'col7=27', 'col8=28', 'col9=29']
['col0=30', 'col1=31', 'col2=32', 'col3=33', 'col4=34', 'col5=35', 'col6=36', 'col7=37', 'col8=38', 'col9=39']
['col0=40', 'col1=41', 'col2=42', 'col3=43', 'col4=44', 'col5=45', 'col6=46', 'col7=47', 'col8=48', 'col9=49']
['col0=50', 'col1=51', 'col2=52', 'col3=53', 'col4=54', 'col5=55', 'col6=56', 'col7=57', 'col8=58', 'col9=59']
['col0=60', 'col1=61', 'col2=62', 'col3=63', 'col4=64', 'col5=65', 'col6=66', 'col7=67', 'col8=68', 'col9=69']
['col0=70', 'col1=71', 'col2=72', 'col3=73', 'col4=74', 'col5=75', 'col6=76', 'col7=77', 'col8=78', 'col9=79']
['col0=80', 'col1=81', 'col2=82', 'col3=83', 'col4=84', 'col5=85', 'col6=86', 'col7=87', 'col8=88', 'col9=89']
['col0=90', 'col1=91', 'col2=92', 'col3=93', 'col4=94', 'col5=95', 'col6=96', 'col7=97', 'col8=98', 'col9=99']

Angular and debounce

DebounceTime in Angular 7 with RxJS v6

Source Link

Demo Link

enter image description here

In HTML Template

<input type="text" #movieSearchInput class="form-control"
            placeholder="Type any movie name" [(ngModel)]="searchTermModel" />

In component

    ....
    ....
    export class AppComponent implements OnInit {

    @ViewChild('movieSearchInput') movieSearchInput: ElementRef;
    apiResponse:any;
    isSearching:boolean;

        constructor(
        private httpClient: HttpClient
        ) {
        this.isSearching = false;
        this.apiResponse = [];
        }

    ngOnInit() {
        fromEvent(this.movieSearchInput.nativeElement, 'keyup').pipe(
        // get value
        map((event: any) => {
            return event.target.value;
        })
        // if character length greater then 2
        ,filter(res => res.length > 2)
        // Time in milliseconds between key events
        ,debounceTime(1000)        
        // If previous query is diffent from current   
        ,distinctUntilChanged()
        // subscription for response
        ).subscribe((text: string) => {
            this.isSearching = true;
            this.searchGetCall(text).subscribe((res)=>{
            console.log('res',res);
            this.isSearching = false;
            this.apiResponse = res;
            },(err)=>{
            this.isSearching = false;
            console.log('error',err);
            });
        });
    }

    searchGetCall(term: string) {
        if (term === '') {
        return of([]);
        }
        return this.httpClient.get('http://www.omdbapi.com/?s=' + term + '&apikey=' + APIKEY,{params: PARAMS.set('search', term)});
    }

    }