Programs & Examples On #Data importer

DataGridView - Focus a specific cell

I had a similar problem. I've hidden some columns and afterwards I tried to select the first row. This didn't really work:

datagridview1.Rows[0].Selected = true;

So I tried selecting cell[0,0], but it also didn't work, because this cell was not displayed. Now my final solution is working very well:

datagridview1.SelectionMode = DataGridViewSelectionMode.FullRowSelect;    
datagridview1.CurrentCell = datagridview1.FirstDisplayedCell;

So this selects the complete first row.

How to delete rows from a pandas DataFrame based on a conditional expression

To directly answer this question's original title "How to delete rows from a pandas DataFrame based on a conditional expression" (which I understand is not necessarily the OP's problem but could help other users coming across this question) one way to do this is to use the drop method:

df = df.drop(some labels)
df = df.drop(df[<some boolean condition>].index)

Example

To remove all rows where column 'score' is < 50:

df = df.drop(df[df.score < 50].index)

In place version (as pointed out in comments)

df.drop(df[df.score < 50].index, inplace=True)

Multiple conditions

(see Boolean Indexing)

The operators are: | for or, & for and, and ~ for not. These must be grouped by using parentheses.

To remove all rows where column 'score' is < 50 and > 20

df = df.drop(df[(df.score < 50) & (df.score > 20)].index)

Should I set max pool size in database connection string? What happens if I don't?

"currently yes but i think it might cause problems at peak moments" I can confirm, that I had a problem where I got timeouts because of peak requests. After I set the max pool size, the application ran without any problems. IIS 7.5 / ASP.Net

Where is debug.keystore in Android Studio

From the Android Developers documentation about Signing your app :

Expiry of the debug certificate

[...] The file is stored in the following locations:

  • ~/.android/ on OS X and Linux
  • C:\Documents and Settings\<user>\.android\ on Windows XP
  • C:\Users\<user>\.android\ on Windows Vista and Windows 7, 8, and 10

How to change btn color in Bootstrap

I had run into the similar problem recently, and managed to fix it with adding classes

  body .btn-primary {
    background-color: #7bc143;
    border-color: #7bc143;
    color: #FFF; }
    body .btn-primary:hover, body .btn-primary:focus {
      border-color: #6fb03a;
      background-color: #6fb03a;
      color: #FFF; }
    body .btn-primary:active, body .btn-primary:visited, body .btn-primary:active:focus, body .btn-primary:active:hover {
      border-color: #639d34;
      background-color: #639d34;
      color: #FFF; }

Also pay attention to [disabled] and [disabled]:hover, if this class is used on input[type=submit]. Like this:

body .btn-primary[disabled], body .btn-primary[disabled]:hover {
  background-color: #7bc143;
  border-color: #7bc143; }

How to increase Heap size of JVM

-XmxSIZE

For example: -Xmx1024M

What is the recommended project structure for spring boot rest projects?

Though this question has an accepted answer, still I would like to share my project structure for RESTful services.

src/main/java
    +- com
        +- example
            +- Application.java
            +- ApplicationConstants.java
                +- configuration
                |   +- ApplicationConfiguration.java
                +- controller
                |   +- ApplicationController.java
                +- dao
                |   +- impl
                |   |   +- ApplicationDaoImpl.java
                |   +- ApplicationDao.java
                +- dto
                |   +- ApplicationDto.java
                +- service
                |   +- impl
                |   |   +- ApplicationServiceImpl.java
                |   +- ApplicationService.java
                +- util
                |   +- ApplicationUtils.java
                +- validation
                |   +- impl
                |   |   +- ApplicationValidationImpl.java
                |   +- ApplicationValidation.java

DAO = Data Access Object.
DTO = Data Transfer Object.

URL.Action() including route values

You also can use in this form:

<a href="@Url.Action("Information", "Admin", null)"> Admin</a>

Export specific rows from a PostgreSQL table as INSERT SQL script

For a data-only export use COPY.
You get a file with one table row per line as plain text (not INSERT commands), it's smaller and faster:

COPY (SELECT * FROM nyummy.cimory WHERE city = 'tokio') TO '/path/to/file.csv';

Import the same to another table of the same structure anywhere with:

COPY other_tbl FROM '/path/to/file.csv';

COPY writes and read files local to the server, unlike client programs like pg_dump or psql which read and write files local to the client. If both run on the same machine, it doesn't matter much, but it does for remote connections.

There is also the \copy command of psql that:

Performs a frontend (client) copy. This is an operation that runs an SQL COPY command, but instead of the server reading or writing the specified file, psql reads or writes the file and routes the data between the server and the local file system. This means that file accessibility and privileges are those of the local user, not the server, and no SQL superuser privileges are required.

How to set time to a date object in java

Calendar cal = Calendar.getInstance();
cal.set(Calendar.HOUR_OF_DAY,17);
cal.set(Calendar.MINUTE,30);
cal.set(Calendar.SECOND,0);
cal.set(Calendar.MILLISECOND,0);

Date d = cal.getTime();

Also See

How to not wrap contents of a div?

A combination of both float: left; white-space: nowrap; worked for me.

Each of them independently didn't accomplish the desired result.

How can I delete all cookies with JavaScript?

There is no 100% solution to delete browser cookies.

The problem is that cookies are uniquely identified by not just by their key "name" but also their "domain" and "path".

Without knowing the "domain" and "path" of a cookie, you cannot reliably delete it. This information is not available through JavaScript's document.cookie. It's not available through the HTTP Cookie header either!

However, if you know the name, path and domain of a cookie, then you can clear it by setting an empty cookie with an expiry date in the past, for example:

function clearCookie(name, domain, path){
    var domain = domain || document.domain;
    var path = path || "/";
    document.cookie = name + "=; expires=" + +new Date + "; domain=" + domain + "; path=" + path;
};

Java: how do I get a class literal from a generic type?

The Java Generics FAQ and therefore also cletus' answer sound like there is no point in having Class<List<T>>, however the real problem is that this is extremely dangerous:

@SuppressWarnings("unchecked")
Class<List<String>> stringListClass = (Class<List<String>>) (Class<?>) List.class;

List<Integer> intList = new ArrayList<>();
intList.add(1);
List<String> stringList = stringListClass.cast(intList);
// Surprise!
String firstElement = stringList.get(0);

The cast() makes it look as if it is safe, but in reality it is not safe at all.


Though I don't get where there can't be List<?>.class = Class<List<?>> since this would be pretty helpful when you have a method which determines the type based on the generic type of a Class argument.

For getClass() there is JDK-6184881 requesting to switch to using wildcards, however it does not look like this change will be performed (very soon) since it is not compatible with previous code (see this comment).

Convert any object to a byte[]

Using Encoding.UTF8.GetBytes is faster than using MemoryStream. Here, I am using NewtonsoftJson to convert input object to JSON string and then getting bytes from JSON string.

byte[] SerializeObject(object value) =>Encoding.UTF8.GetBytes(JsonConvert.SerializeObject(value));

Benchmark for @Daniel DiPaolo's version with this version

Method                    |     Mean |     Error |    StdDev |   Median |  Gen 0 | Allocated |
--------------------------|----------|-----------|-----------|----------|--------|-----------| 
ObjectToByteArray         | 4.983 us | 0.1183 us | 0.2622 us | 4.887 us | 0.9460 |    3.9 KB |
ObjectToByteArrayWithJson | 1.548 us | 0.0309 us | 0.0690 us | 1.528 us | 0.3090 |   1.27 KB |

How do I remove a key from a JavaScript object?

If you are using Underscore.js or Lodash, there is a function 'omit' that will do it.
http://underscorejs.org/#omit

var thisIsObject= {
    'Cow' : 'Moo',
    'Cat' : 'Meow',
    'Dog' : 'Bark'
};
_.omit(thisIsObject,'Cow'); //It will return a new object

=> {'Cat' : 'Meow', 'Dog' : 'Bark'}  //result

If you want to modify the current object, assign the returning object to the current object.

thisIsObject = _.omit(thisIsObject,'Cow');

With pure JavaScript, use:

delete thisIsObject['Cow'];

Another option with pure JavaScript.

thisIsObject.cow = undefined;

thisIsObject = JSON.parse(JSON.stringify(thisIsObject ));

Rename column SQL Server 2008

You should also specify the schema of the table or you might get this error:

Msg 15248, Level 11, State 1, Procedure sp_rename, Line 238 Either the parameter @objname is ambiguous or the claimed @objtype (COLUMN) is wrong.

If it is a deployment script I would also recommend adding some additional security to it.

IF EXISTS (
        SELECT 1
        FROM sys.columns
        WHERE
            name = 'OldColumnName' AND
            object_name(object_id) = 'TableName'
    ) AND
    NOT EXISTS (
        SELECT 1
        FROM sys.columns
        WHERE
            name = 'NewColumnName' AND
            object_name(object_id) = 'TableName'
    )
    EXEC sp_RENAME 'SchemaName.TableName.OldColumnName', 'NewColumnName', 'COLUMN';

What is the role of "Flatten" in Keras?

It is rule of thumb that the first layer in your network should be the same shape as your data. For example our data is 28x28 images, and 28 layers of 28 neurons would be infeasible, so it makes more sense to 'flatten' that 28,28 into a 784x1. Instead of wriitng all the code to handle that ourselves, we add the Flatten() layer at the begining, and when the arrays are loaded into the model later, they'll automatically be flattened for us.

Mysql: Select all data between two dates

its very easy to handle this situation

You can use BETWEEN CLAUSE in combination with date_sub( now( ) , INTERVAL 30 DAY ) AND NOW( )

SELECT
    sc_cust_design.design_id as id,
    sc_cust_design.main_image,
    FROM
    sc_cust_design
WHERE
    sc_cust_design.publish = 1 
    AND **`datein`BETWEEN date_sub( now( ) , INTERVAL 30 DAY ) AND NOW( )**

Happy Coding :)

How to append the output to a file?

Use >> to append:

command >> file

C# Passing Function as Argument

public static T Runner<T>(Func<T> funcToRun)
{
    //Do stuff before running function as normal
    return funcToRun();
}

Usage:

var ReturnValue = Runner(() => GetUser(99));

Running Bash commands in Python

Also you can use 'os.popen'. Example:

import os

command = os.popen('ls -al')
print(command.read())
print(command.close())

Output:

total 16
drwxr-xr-x 2 root root 4096 ago 13 21:53 .
drwxr-xr-x 4 root root 4096 ago 13 01:50 ..
-rw-r--r-- 1 root root 1278 ago 13 21:12 bot.py
-rw-r--r-- 1 root root   77 ago 13 21:53 test.py

None

This certificate has an invalid issuer Apple Push Services

Follow the below steps:

  1. Download and install from here. Double click and install it.
  2. Select "View" -> "Show Expired Certificates" in Keychain app.
  3. Remove Apple Worldwide Developer Relations Certificate Authority certificates from "login" tab and "System" tab in Keychain app.

If you don't find your WWDR certificate in Login or System tab, then select category "All items" on the left side. Most probably you will get to see an expired WWDR certificate here, and you can remove it. An expired certificate is always shown with a red asterisk.

Error when trying vagrant up

edit the vagrant file created by vagrant init in the same directory and enter the box name in the line config.vm.box = "ubuntu/trusty64" where ubuntu/trusty64 is your base box. Now vagrant up will download and set ubuntu/trusty64 as base box for you.

How to get the current time in milliseconds from C in Linux?

This can be achieved using the POSIX clock_gettime function.

In the current version of POSIX, gettimeofday is marked obsolete. This means it may be removed from a future version of the specification. Application writers are encouraged to use the clock_gettime function instead of gettimeofday.

Here is an example of how to use clock_gettime:

#define _POSIX_C_SOURCE 200809L

#include <inttypes.h>
#include <math.h>
#include <stdio.h>
#include <time.h>

void print_current_time_with_ms (void)
{
    long            ms; // Milliseconds
    time_t          s;  // Seconds
    struct timespec spec;

    clock_gettime(CLOCK_REALTIME, &spec);

    s  = spec.tv_sec;
    ms = round(spec.tv_nsec / 1.0e6); // Convert nanoseconds to milliseconds
    if (ms > 999) {
        s++;
        ms = 0;
    }

    printf("Current time: %"PRIdMAX".%03ld seconds since the Epoch\n",
           (intmax_t)s, ms);
}

If your goal is to measure elapsed time, and your system supports the "monotonic clock" option, then you should consider using CLOCK_MONOTONIC instead of CLOCK_REALTIME.

Use the auto keyword in C++ STL

If you want a code that is readable by all programmers (c++, java, and others) use the original old form instead of cryptographic new features

atp::ta::DataDrawArrayInfo* ddai;
for(size_t i = 0; i < m_dataDraw->m_dataDrawArrayInfoList.size(); i++) {
    ddai = m_dataDraw->m_dataDrawArrayInfoList[i];
    //...
}

How can I sanitize user input with PHP?

You never sanitize input.

You always sanitize output.

The transforms you apply to data to make it safe for inclusion in an SQL statement are completely different from those you apply for inclusion in HTML are completely different from those you apply for inclusion in Javascript are completely different from those you apply for inclusion in LDIF are completely different from those you apply to inclusion in CSS are completely different from those you apply to inclusion in an Email....

By all means validate input - decide whether you should accept it for further processing or tell the user it is unacceptable. But don't apply any change to representation of the data until it is about to leave PHP land.

A long time ago someone tried to invent a one-size fits all mechanism for escaping data and we ended up with "magic_quotes" which didn't properly escape data for all output targets and resulted in different installation requiring different code to work.

How to update (append to) an href in jquery?

var _href = $("a.directions-link").attr("href");
$("a.directions-link").attr("href", _href + '&saddr=50.1234567,-50.03452');

To loop with each()

$("a.directions-link").each(function() {
   var $this = $(this);       
   var _href = $this.attr("href"); 
   $this.attr("href", _href + '&saddr=50.1234567,-50.03452');
});

Split string based on regex

You could use a lookahead:

re.split(r'[ ](?=[A-Z]+\b)', input)

This will split at every space that is followed by a string of upper-case letters which end in a word-boundary.

Note that the square brackets are only for readability and could as well be omitted.

If it is enough that the first letter of a word is upper case (so if you would want to split in front of Hello as well) it gets even easier:

re.split(r'[ ](?=[A-Z])', input)

Now this splits at every space followed by any upper-case letter.

Mobile Redirect using htaccess

Tim Stone's solution is on the right track, but his initial rewriterule and and his cookie name in the final condition are different, and you can not write and read a cookie in the same request.

Here is the finalized working code:

RewriteEngine on
RewriteBase /
# Check if this is the noredirect query string
RewriteCond %{QUERY_STRING} (^|&)m=0(&|$)
# Set a cookie, and skip the next rule
RewriteRule ^ - [CO=mredir:0:www.website.com]

# Check if this looks like a mobile device
# (You could add another [OR] to the second one and add in what you
#  had to check, but I believe most mobile devices should send at
#  least one of these headers)
RewriteCond %{HTTP:x-wap-profile} !^$ [OR]
RewriteCond %{HTTP:Profile}       !^$ [OR]
RewriteCond %{HTTP_USER_AGENT} "acs|alav|alca|amoi|audi|aste|avan|benq|bird|blac|blaz|brew|cell|cldc|cmd-" [NC,OR]
RewriteCond %{HTTP_USER_AGENT} "dang|doco|eric|hipt|inno|ipaq|java|jigs|kddi|keji|leno|lg-c|lg-d|lg-g|lge-" [NC,OR]
RewriteCond %{HTTP_USER_AGENT}  "maui|maxo|midp|mits|mmef|mobi|mot-|moto|mwbp|nec-|newt|noki|opwv" [NC,OR]
RewriteCond %{HTTP_USER_AGENT} "palm|pana|pant|pdxg|phil|play|pluc|port|prox|qtek|qwap|sage|sams|sany" [NC,OR]
RewriteCond %{HTTP_USER_AGENT} "sch-|sec-|send|seri|sgh-|shar|sie-|siem|smal|smar|sony|sph-|symb|t-mo" [NC,OR]
RewriteCond %{HTTP_USER_AGENT} "teli|tim-|tosh|tsm-|upg1|upsi|vk-v|voda|w3cs|wap-|wapa|wapi" [NC,OR]
RewriteCond %{HTTP_USER_AGENT} "wapp|wapr|webc|winw|winw|xda|xda-" [NC,OR]
RewriteCond %{HTTP_USER_AGENT} "up.browser|up.link|windowssce|iemobile|mini|mmp" [NC,OR]
RewriteCond %{HTTP_USER_AGENT} "symbian|midp|wap|phone|pocket|mobile|pda|psp" [NC]
RewriteCond %{HTTP_USER_AGENT} !macintosh [NC]

# Check if we're not already on the mobile site
RewriteCond %{HTTP_HOST}          !^m\.
# Can not read and write cookie in same request, must duplicate condition
RewriteCond %{QUERY_STRING} !(^|&)m=0(&|$) 

# Check to make sure we haven't set the cookie before
RewriteCond %{HTTP_COOKIE}        !^.*mredir=0.*$ [NC]

# Now redirect to the mobile site
RewriteRule ^ http://m.website.com [R,L]

Query an XDocument for elements by name at any depth

I am using XPathSelectElements extension method which works in the same way to XmlDocument.SelectNodes method:

using System;
using System.Xml.Linq;
using System.Xml.XPath; // for XPathSelectElements

namespace testconsoleApp
{
    class Program
    {
        static void Main(string[] args)
        {
            XDocument xdoc = XDocument.Parse(
                @"<root>
                    <child>
                        <name>john</name>
                    </child>
                    <child>
                        <name>fred</name>
                    </child>
                    <child>
                        <name>mark</name>
                    </child>
                 </root>");

            foreach (var childElem in xdoc.XPathSelectElements("//child"))
            {
                string childName = childElem.Element("name").Value;
                Console.WriteLine(childName);
            }
        }
    }
}

Resource from src/main/resources not found after building with maven

Once after we build the jar will have the resource files under BOOT-INF/classes or target/classes folder, which is in classpath, use the below method and pass the file under the src/main/resources as method call getAbsolutePath("certs/uat_staging_private.ppk"), even we can place this method in Utility class and the calling Thread instance will be taken to load the ClassLoader to get the resource from class path.

 public String getAbsolutePath(String fileName) throws IOException {
      return Thread.currentThread().getContextClassLoader().getResource(fileName).getFile();
  }

enter image description here enter image description here

we can add the below tag to tag in pom.xml to include these resource files to build target/classes folder

<resources>
        <resource>
            <directory>src/main/resources</directory>
            <includes>
                <include>**/*.properties</include>
                <include>**/*.ppk</include>
            </includes>
        </resource>
</resources>

Javascript - Append HTML to container element without innerHTML

How to fish and while using strict code. There are two prerequisite functions needed at the bottom of this post.

xml_add('before', id_('element_after'), '<span xmlns="http://www.w3.org/1999/xhtml">Some text.</span>');

xml_add('after', id_('element_before'), '<input type="text" xmlns="http://www.w3.org/1999/xhtml" />');

xml_add('inside', id_('element_parent'), '<input type="text" xmlns="http://www.w3.org/1999/xhtml" />');

Add multiple elements (namespace only needs to be on the parent element):

xml_add('inside', id_('element_parent'), '<div xmlns="http://www.w3.org/1999/xhtml"><input type="text" /><input type="button" /></div>');

Dynamic reusable code:

function id_(id) {return (document.getElementById(id)) ? document.getElementById(id) : false;}

function xml_add(pos, e, xml)
{
 e = (typeof e == 'string' && id_(e)) ? id_(e) : e;

 if (e.nodeName)
 {
  if (pos=='after') {e.parentNode.insertBefore(document.importNode(new DOMParser().parseFromString(xml,'application/xml').childNodes[0],true),e.nextSibling);}
  else if (pos=='before') {e.parentNode.insertBefore(document.importNode(new DOMParser().parseFromString(xml,'application/xml').childNodes[0],true),e);}
  else if (pos=='inside') {e.appendChild(document.importNode(new DOMParser().parseFromString(xml,'application/xml').childNodes[0],true));}
  else if (pos=='replace') {e.parentNode.replaceChild(document.importNode(new DOMParser().parseFromString(xml,'application/xml').childNodes[0],true),e);}
  //Add fragment and have it returned.
 }
}

-XX:MaxPermSize with or without -XX:PermSize

If you're doing some performance tuning it's often recommended to set both -XX:PermSize and -XX:MaxPermSize to the same value to increase JVM efficiency.

Here is some information:

  1. Support for large page heap on x86 and amd64 platforms
  2. Java Support for Large Memory Pages
  3. Setting the Permanent Generation Size

You can also specify -XX:+CMSClassUnloadingEnabled to enable class unloading option if you are using CMS GC. It may help to decrease the probability of Java.lang.OutOfMemoryError: PermGen space

How to insert a character in a string at a certain position?

Using ApacheCommons3 StringUtils, you could also do

int j = 123456;
String s = Integer.toString(j);
int pos = s.length()-2;

s = StringUtils.overlay(s,".", pos, pos);

it's basically substring concatenation but shorter if you don't mind using libraries, or already depending on StringUtils

How to calculate number of days between two dates

MVC i have two input text 1: number of day 2: datetime picker

 @Html.TextBox("HeaderINVID", null, new { @id = "HeaderINVID", @type = "number", @class = "form-control", autocomplete = "off", placeholder = "Day Count " })

  @Html.TextBox("HeaderINVDT", null, new { id = "HeaderINVDT", @class = "form-control format-picker", autocomplete = "off", placeholder = " Date" })

javascipt

to calculate number from date use

    $("#HeaderINVID").bind("keyup", function (e) {
        var INVID = $("#HeaderINVID").val();
        var date = moment()
            .add(INVID, 'd')
            .toDate(); 
        $("#HeaderINVDT").val(moment(date).format('YYYY-MM-DD')) ;
    })

to calculate number of days between two dates use

  $("#HeaderINVDT").bind('change', function (e) {
        var StDT = moment($("#HeaderINVDT").val()).startOf('day');
        var NODT = moment().startOf('day');
        $("#HeaderINVID").val(StDT.diff(NODT, 'days'));
    })

do not forget to add http://momentjs.com/

Python pip install module is not found. How to link python to pip location?

As a quick workaround, and assuming that you are on a bash-like terminal (Linux/OSX), you can try to export the PYTHONPATH environment variable:

export PYTHONPATH="${PYTHONPATH}:/usr/local/lib/python2.7/site-packages:/usr/lib/python2.7/site-packages"

For Python 2.7

Extracting first n columns of a numpy matrix

I know this is quite an old question -

A = [[1, 2, 3],
     [4, 5, 6],
     [7, 8, 9]]

Let's say, you want to extract the first 2 rows and first 3 columns

A_NEW = A[0:2, 0:3]
A_NEW = [[1, 2, 3],
         [4, 5, 6]]

Understanding the syntax

A_NEW = A[start_index_row : stop_index_row, 
          start_index_column : stop_index_column)]

If one wants row 2 and column 2 and 3

A_NEW = A[1:2, 1:3]

Reference the numpy indexing and slicing article - Indexing & Slicing

Best design for a changelog / auditing database table?

According to the principle of separation:

  1. Auditing data tables need to be separate from the main database. Because audit databases can have a lot of historical data, it makes sense from a memory utilization standpoint to keep them separate.

  2. Do not use triggers to audit the whole database, because you will end up with a mess of different databases to support. You will have to write one for DB2, SQLServer, Mysql, etc.

Reshape an array in NumPy

There are two possible result rearrangements (following example by @eumiro). Einops package provides a powerful notation to describe such operations non-ambigously

>> a = np.arange(18).reshape(9,2)

# this version corresponds to eumiro's answer
>> einops.rearrange(a, '(x y) z -> z y x', x=3)

array([[[ 0,  6, 12],
        [ 2,  8, 14],
        [ 4, 10, 16]],

       [[ 1,  7, 13],
        [ 3,  9, 15],
        [ 5, 11, 17]]])

# this has the same shape, but order of elements is different (note that each paer was trasnposed)
>> einops.rearrange(a, '(x y) z -> z x y', x=3)

array([[[ 0,  2,  4],
        [ 6,  8, 10],
        [12, 14, 16]],

       [[ 1,  3,  5],
        [ 7,  9, 11],
        [13, 15, 17]]])

Difference Between Schema / Database in MySQL

As defined in the MySQL Glossary:

In MySQL, physically, a schema is synonymous with a database. You can substitute the keyword SCHEMA instead of DATABASE in MySQL SQL syntax, for example using CREATE SCHEMA instead of CREATE DATABASE.

Some other database products draw a distinction. For example, in the Oracle Database product, a schema represents only a part of a database: the tables and other objects owned by a single user.

How to use Simple Ajax Beginform in Asp.net MVC 4?

All This Work :)

Model

  public partial class ClientMessage
    {
        public int IdCon { get; set; } 
        public string Name { get; set; }
        public string Email { get; set; }  
    }

Controller

   public class TestAjaxBeginFormController : Controller{  

 projectNameEntities db = new projectNameEntities();

        public ActionResult Index(){  
            return View();
        }

        [HttpPost] 
        public ActionResult GetClientMessages(ClientMessage Vm) {
            var model = db.ClientMessages.Where(x => x.Name.Contains(Vm.Name));
            return PartialView("_PartialView", model);
        } 
}

View index.cshtml

@model  projectName.Models.ClientMessage 
@{ 
    Layout = null;
}

<script src="~/Scripts/jquery-1.9.1.js"></script>
<script src="~/Scripts/jquery.unobtrusive-ajax.js"></script>
<script>
    //\\\\\\\ JS  retrun message SucccessPost or FailPost
    function SuccessMessage() {
        alert("Succcess Post");
    }
    function FailMessage() {
        alert("Fail Post");
    } 
</script>

<h1>Page Index</h1> 

@using (Ajax.BeginForm("GetClientMessages", "TestAjaxBeginForm", null , new AjaxOptions
{
    HttpMethod = "POST",
    OnSuccess = "SuccessMessage",
    OnFailure = "FailMessage" ,
    UpdateTargetId = "resultTarget"  
}, new { id = "MyNewNameId" })) // set new Id name for  Form
{
    @Html.AntiForgeryToken()

    @Html.EditorFor(x => x.Name) 
     <input type="submit" value="Search" /> 

}


<div id="resultTarget">  </div>

View _PartialView.cshtml

@model  IEnumerable<projectName.Models.ClientMessage >
<table> 

@foreach (var item in Model) { 

    <tr> 
        <td>@Html.DisplayFor(modelItem => item.IdCon)</td>
        <td>@Html.DisplayFor(modelItem => item.Name)</td>
        <td>@Html.DisplayFor(modelItem => item.Email)</td>
    </tr>

}

</table>

If strings starts with in PowerShell

$Group is an object, but you will actually need to check if $Group.samaccountname.StartsWith("string").

Change $Group.StartsWith("S_G_") to $Group.samaccountname.StartsWith("S_G_").

ASP.NET MVC5/IIS Express unable to debug - Code Not Running

Delete File C:\Users\congt\Documents\IISExpress

Placeholder in IE9

A bit late to the party but I use my tried and trusted JS that takes advantage of Modernizr. Can be copy/pasted and applied to any project. Works every time:

// Placeholder fallback
if(!Modernizr.input.placeholder){

    $('[placeholder]').focus(function() {
      var input = $(this);
      if (input.val() == input.attr('placeholder')) {
        input.val('');
        input.removeClass('placeholder');
      }
    }).blur(function() {
      var input = $(this);
      if (input.val() == '' || input.val() == input.attr('placeholder')) {
        input.addClass('placeholder');
        input.val(input.attr('placeholder'));
      }
    }).blur();
    $('[placeholder]').parents('form').submit(function() {
      $(this).find('[placeholder]').each(function() {
        var input = $(this);
        if (input.val() == input.attr('placeholder')) {
          input.val('');
        }
      })
    });

}

Fastest way to ping a network range and return responsive hosts?

The following (evil) code runs more than TWICE as fast as the nmap method

for i in {1..254} ;do (ping 192.168.1.$i -c 1 -w 5  >/dev/null && echo "192.168.1.$i" &) ;done

takes around 10 seconds, where the standard nmap

nmap -sP 192.168.1.1-254

takes 25 seconds...

Handling null values in Freemarker

Use ?? operator at the end of your <#if> statement.

This example demonstrates how to handle null values for two lists in a Freemaker template.

List of cars:
<#if cars??>
    <#list cars as car>${car.owner};</#list>
</#if>
List of motocycles:
<#if motocycles??>
    <#list motocycles as motocycle>${motocycle.owner};</#list>
</#if>

Check if a given key already exists in a dictionary

The ways in which you can get the results are:

Which is better is dependent on 3 things:

  1. Does the dictionary 'normally has the key' or 'normally does not have the key'.
  2. Do you intend to use conditions like if...else...elseif...else?
  3. How big is dictionary?

Read More: http://paltman.com/try-except-performance-in-python-a-simple-test/

Use of try/block instead of 'in' or 'if':

try:
    my_dict_of_items[key_i_want_to_check]
except KeyError:
    # Do the operation you wanted to do for "key not present in dict".
else:
    # Do the operation you wanted to do with "key present in dict."

Twitter Bootstrap alert message close and open again

I ran into this problem as well and the the problem with simply hacking the close-button is that I still need access to the standard bootstrap alert-close events.

My solution was to write a small, customisable, jquery plugin that injects a properly formed Bootstrap 3 alert (with or without close button as you need it) with a minimum of fuss and allows you to easily regenerate it after the box is closed.

See https://github.com/davesag/jquery-bs3Alert for usage, tests, and examples.

Accessing a resource via codebehind in WPF

I got the resources on C# (Desktop WPF W/ .NET Framework 4.8) using the code below

{DefaultNamespace}.Properties.Resources.{ResourceName}

How to format font style and color in echo

You should also use the style 'color' and not 'font-color'

<?php

foreach($months as $key => $month){
  if(strpos($filename,$month)!==false){
        echo "<style = 'color: #ff0000;'> Movie List for {$key} 2013 </style>";
    }
}

?>

In general, the comments on double and single quotes are correct in other suggestions. $Variables only execute in double quotes.

php - add + 7 days to date format mm dd, YYYY

onClose: function(selectedDate) {

    $("#dpTodate").datepicker("option", "minDate", selectedDate);
    var maxDate = new Date(selectedDate);

     maxDate.setDate(maxDate.getDate() + 6); //6 days extra in from date

     $("#dpTodate").datepicker("option", "maxDate", maxDate);
}

android on Text Change Listener

A bit late of a answer, but here is a reusable solution:

/**
 * An extension of TextWatcher which stops further callbacks being called as 
 * a result of a change happening within the callbacks themselves.
 */
public abstract class EditableTextWatcher implements TextWatcher {

    private boolean editing;

    @Override
    public final void beforeTextChanged(CharSequence s, int start, 
                                                    int count, int after) {
        if (editing)
            return;

        editing = true;
        try {
            beforeTextChange(s, start, count, after);
        } finally {
            editing = false;
        }
    }

    protected abstract void beforeTextChange(CharSequence s, int start, 
                                                     int count, int after);

    @Override
    public final void onTextChanged(CharSequence s, int start, 
                                                int before, int count) {
        if (editing)
            return;

        editing = true;
        try {
            onTextChange(s, start, before, count);
        } finally {
            editing = false;
        }
    }

    protected abstract void onTextChange(CharSequence s, int start, 
                                            int before, int count);

    @Override
    public final void afterTextChanged(Editable s) {
        if (editing)
            return;

        editing = true;
        try {
            afterTextChange(s);
        } finally {
            editing = false;
        }
    }

    public boolean isEditing() {
        return editing;
    }

    protected abstract void afterTextChange(Editable s);
}

So when the above is used, any setText() calls happening within the TextWatcher will not result in the TextWatcher being called again:

/**
 * A setText() call in any of the callbacks below will not result in TextWatcher being 
 * called again.
 */
public class MyTextWatcher extends EditableTextWatcher {

    @Override
    protected void beforeTextChange(CharSequence s, int start, int count, int after) {
    }

    @Override
    protected void onTextChange(CharSequence s, int start, int before, int count) {
    }

    @Override
    protected void afterTextChange(Editable s) {
    }
}

How to set background color in jquery

You can add your attribute on callback function ({key} , speed.callback, like is

$('.usercontent').animate( {
    backgroundColor:'#ddd',
},1000,function () {
    $(this).css("backgroundColor","red")
});

Executing Javascript from Python

Using PyV8, I can do this. However, I have to replace document.write with return because there's no DOM and therefore no document.

import PyV8
ctx = PyV8.JSContext()
ctx.enter()

js = """
function escramble_758(){
var a,b,c
a='+1 '
b='84-'
a+='425-'
b+='7450'
c='9'
document.write(a+c+b)
}
escramble_758()
"""

print ctx.eval(js.replace("document.write", "return "))

Or you could create a mock document object

class MockDocument(object):

    def __init__(self):
        self.value = ''

    def write(self, *args):
        self.value += ''.join(str(i) for i in args)


class Global(PyV8.JSClass):
    def __init__(self):
        self.document = MockDocument()

scope = Global()
ctx = PyV8.JSContext(scope)
ctx.enter()
ctx.eval(js)
print scope.document.value

Creating a blurring overlay view

Simple answer is Add a subview and change it's alpha.

UIView *mainView = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 200, 200)];
UIView *subView = [[UIView alloc] initWithFrame:popupView.frame];
UIColor * backImgColor = [UIColor colorWithPatternImage:[UIImage imageNamed:@"blue_Img.png"]];
subView.backgroundColor = backImgColor;
subView.alpha = 0.5;
[mainView addSubview:subView];

Datagridview full row selection but get single cell value

If you want to get the contents of selected cell; you need the index of row and cell.

int rowindex = dataGridView1.CurrentCell.RowIndex;
int columnindex = dataGridView1.CurrentCell.ColumnIndex; 

dataGridView1.Rows[rowindex].Cells[columnindex].Value.ToString();

Interface or an Abstract Class: which one to use?

The main difference is an abstract class can contain default implementation whereas an interface cannot.

An interface is a contract of behaviour without any implementation.

List directory in Go

Even simpler, use path/filepath:

package main    

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

func main() {
    files, err := filepath.Glob("*")
    if err != nil {
        log.Fatal(err)
    }
    fmt.Println(files) // contains a list of all files in the current directory
}

How do I get DOUBLE_MAX?

You are looking for the float.h header.

DELETE ... FROM ... WHERE ... IN

You can achieve this using exists:

DELETE
  FROM table1
 WHERE exists(
           SELECT 1
             FROM table2
            WHERE table2.stn = table1.stn
              and table2.jaar = year(table1.datum)
       )

Using setImageDrawable dynamically to set image in an ImageView

You can also use something like:

imageView.setImageDrawable(ActivityCompat.getDrawable(getContext(), R.drawable.generatedID));

or using Picasso:

Picasso.with(getContext()).load(R.drawable.generatedId).into(imageView);

The specified child already has a parent. You must call removeView() on the child's parent first (Android)

I came here on searching the error with my recyclerview but the solution didn't work (obviously). I have written the cause and the solution for it in case of recyclerview. Hope it helps someone.

The error is caused if in the onCreateViewHolder() the following method is followed:

layoutInflater = LayoutInflater.from(context);
return new VH(layoutInflater.inflate(R.layout.single_row, parent));

Instead it should be

return new VH(layoutInflater.inflate(R.layout.single_row, null));

redistributable offline .NET Framework 3.5 installer for Windows 8

After several month without real solution for this problem, I suppose that the best solution is to upgrade the application to .NET framework 4.0, which is supported by Windows 8, Windows 10 and Windows 2012 Server by default and it is still available as offline installation for Windows XP.

How to reverse apply a stash?

This is long over due, but if i interpret the problem correctly i have found a simple solution, note, this is an explanation in my own terminology:

git stash [save] will save away current changes and set your current branch to the "clean state"

git stash list gives something like: stash@{0}: On develop: saved testing-stuff

git apply stash@{0} will set current branch as before stash [save]

git checkout . Will set current branch as after stash [save]

The code that is saved in the stash is not lost, it can be found by git apply stash@{0} again.

Anywhay, this worked for me!

How to programmatically set the SSLContext of a JAX-WS client?

For those trying and still not getting it to work, this did it for me with Wildfly 8, using the dynamic Dispatcher:

bindingProvider.getRequestContext().put("com.sun.xml.ws.transport.https.client.SSLSocketFactory", yourSslSocketFactory);

Note that the internal part from the Property key is gone here.

Remove header and footer from window.print()

@media print {
    .footer,
    #non-printable {
        display: none !important;
    }
    #printable {
        display: block;
    }
}

How can I filter a date of a DateTimeField in Django?

Here are the results I got with ipython's timeit function:

from datetime import date
today = date.today()

timeit[Model.objects.filter(date_created__year=today.year, date_created__month=today.month, date_created__day=today.day)]
1000 loops, best of 3: 652 us per loop

timeit[Model.objects.filter(date_created__gte=today)]
1000 loops, best of 3: 631 us per loop

timeit[Model.objects.filter(date_created__startswith=today)]
1000 loops, best of 3: 541 us per loop

timeit[Model.objects.filter(date_created__contains=today)]
1000 loops, best of 3: 536 us per loop

contains seems to be faster.

Find first element by predicate

Already answered by @AjaxLeung, but in comments and hard to find.
For check only

lst.stream()
    .filter(x -> x > 5)
    .findFirst()
    .isPresent()

is simplified to

lst.stream()
    .anyMatch(x -> x > 5)

Excel VBA code to copy a specific string to clipboard

If the place you're gonna paste have no problem with pasting a table formating (like the browser URL bar), I think the easiest way is this:

Sheets(1).Range("A1000").Value = string
Sheets(1).Range("A1000").Copy
MsgBox "Paste before closing this dialog."
Sheets(1).Range("A1000").Value = ""

How to find and turn on USB debugging mode on Nexus 4

Solution

To see the option for USB debugging mode in Nexus 4 or Android 4.2 or higher OS, do the following:

  • Open up your device’s “Settings”. This can be done by pressing the Menu button while on your home screen and tapping “System settings”
  • Now scroll to the bottom and tap “About phone” or “About tablet”.
  • At the “About” screen, scroll to the bottom and tap on “Build number” seven times.
    • Make sure you tap seven times. If you see a “Not need, you are already a developer!” message pop up, then you know you have done it correctly.

Done! By tapping on “Build number” seven times, you have unlocked USB debugging mode on Android 4.2 and higher. You can now enable/disable it whenever you desire by going to “Settings” -> “Developer Options” -> “Debugging” ->” USB debugging”.

CONCLUSION

That was easy. The best part is you only have to do the tap-build-number-seven-times once. After you do it once, USB debugging has been unlocked and you can enable or disable at your leisure. Please restart after done these steps.

Additional information

Setting up a Device for Development native documentation of Google Android developer site

Update: Google Pixel 3

If you need to facilitate a connection between your device and a computer with the Android SDK (software development kit), view this info.

  1. From a Home screen, swipe up to display all apps.
  2. Navigate: Settings > System > Advanced.
  3. Developer options .
    If Developer options isn't available, navigate: SettingsAbout phone then tap Build number 7 times. Tap the Back icon  to Settings then select System > Advanced > Developer options.
  4. Ensure that the Developer options switch (upper-right) is turned on .
  5. Tap USB debugging to turn on or off .
  6. If prompted with 'Allow USB debugging?', tap OK to confirm.

Doc by Verizon: Original source

How to paste yanked text into the Vim command line

For pasting something from the system clipboard into the Vim command line ("command mode"), use Ctrl+R followed by +. For me, at least on Ubuntu, Shift+Ins is not working.

PS: I am not sure why Ctrl+R followed by *, which is theoretically the same as Ctrl+R followed by + doesn't seem to work always. I searched and discovered the + version and it seems to work always, at least on my box.

Getting Google+ profile picture url with user_id

Simple answer: No

You will have to query the person API and the take the profile image.url data to get the photo. AFAIK there is no default format for that url that contains the userID.

Can't push to the heroku

Make sure you have package.json inside root of your project. Happy coding :)

Python Flask, how to set content type

Use the make_response method to get a response with your data. Then set the mimetype attribute. Finally return this response:

@app.route('/ajax_ddl')
def ajax_ddl():
    xml = 'foo'
    resp = app.make_response(xml)
    resp.mimetype = "text/xml"
    return resp

If you use Response directly, you lose the chance to customize the responses by setting app.response_class. The make_response method uses the app.responses_class to make the response object. In this you can create your own class, add make your application uses it globally:

class MyResponse(app.response_class):
    def __init__(self, *args, **kwargs):
        super(MyResponse, self).__init__(*args, **kwargs)
        self.set_cookie("last-visit", time.ctime())

app.response_class = MyResponse  

git: fatal: I don't handle protocol '??http'

Please Check URL you have pasted and It takes additional h after clone.

So either you have paste full git clone http://<URL>.git or just remove additional letter before git repository URL.

How to run code after some delay in Flutter?

Just adding more description over the above answers

The Timer functionality works with below duration time also:

const Duration(
      {int days = 0,
      int hours = 0,
      int minutes = 0,
      int seconds = 0,
      int milliseconds = 0,
      int microseconds = 0})

Example:

  Timer(Duration(seconds: 3), () {
    print("print after every 3 seconds");
  });

How does `scp` differ from `rsync`?

One major feature of rsync over scp (beside the delta algorithm and encryption if used w/ ssh) is that it automatically verifies if the transferred file has been transferred correctly. Scp will not do that, which occasionally might result in corruption when transferring larger files. So in general rsync is a copy with guarantee.

Centos manpages mention this the end of the --checksum option description:

Note that rsync always verifies that each transferred file was correctly reconstructed on the receiving side by checking a whole-file checksum that is generated as the file is transferred, but that automatic after-the-transfer verification has nothing to do with this option’s before-the-transfer “Does this file need to be updated?” check.

How do you read CSS rule values with JavaScript?

I made a similar helper function which shows the unneeded styles for this page. appends a <div> to the body listing all styles that where not used.

(to be used with the firebug console)

(function getStyles(){var CSSrules,allRules,CSSSheets, unNeeded, currentRule;
CSSSheets=document.styleSheets;

for(j=0;j<CSSSheets.length;j++){
for(i=0;i<CSSSheets[j].cssRules.length;i++){
    currentRule = CSSSheets[j].cssRules[i].selectorText;

    if(!document.querySelectorAll(currentRule).length){ 
       unNeeded+=CSSSheets[j].cssRules[i].cssText+"<br>"; 
  }       
 }
}

docBody=document.getElementsByTagName("body")[0];
allRulesContainer=document.createElement("div");
docBody.appendChild(allRulesContainer);
allRulesContainer.innerHTML=unNeeded+isHover;
return false
})()

Not able to pip install pickle in python 3.6

import pickle

intArray = [i for i in range(1,100)]
output = open('data.pkl', 'wb')
pickle.dump(intArray, output)
output.close()

Test your pickle quickly. pickle is a part of standard python library and available by default.

Removing "bullets" from unordered list <ul>

In your css file add following.

ul{
 list-style-type: none;
}

Convert a matrix to a 1 dimensional array

It might be so late, anyway here is my way in converting Matrix to vector:

library(gdata)
vector_data<- unmatrix(yourdata,byrow=T))

hope that will help

Python Loop: List Index Out of Range

When you call for i in a:, you are getting the actual elements, not the indexes. When we reach the last element, that is 3, b.append(a[i+1]-a[i]) looks for a[4], doesn't find one and then fails. Instead, try iterating over the indexes while stopping just short of the last one, like

for i in range(0, len(a)-1): Do something

Your current code won't work yet for the do something part though ;)

Using ChildActionOnly in MVC

FYI, [ChildActionOnly] is not available in ASP.NET MVC Core. see some info here

.Net picking wrong referenced assembly version

If you are experiencing this problem when testing and/or debugging the application from the Visual Studio environment (ASP.NET Development Server), it is necessary to delete all temporary files on the development website folder. To know where that folder is, look for the ASP.NET Development Server icon on the Windows tray icon (it should have a title like this: ASP.NET Development Server - Port ####), right click the icon and select Show Details; thn, the field Physical path will tell you what the temporary folder is, all items there should be deleted to solve the problem. Build and run again the website and the problem should be solved (again, solved for the Development Environment).

Convert array of integers to comma-separated string

var result = string.Join(",", arr);

This uses the following overload of string.Join:

public static string Join<T>(string separator, IEnumerable<T> values);

Replace preg_replace() e modifier with preg_replace_callback

preg_replace shim with eval support

This is very inadvisable. But if you're not a programmer, or really prefer terrible code, you could use a substitute preg_replace function to keep your /e flag working temporarily.

/**
 * Can be used as a stopgap shim for preg_replace() calls with /e flag.
 * Is likely to fail for more complex string munging expressions. And
 * very obviously won't help with local-scope variable expressions.
 *
 * @license: CC-BY-*.*-comment-must-be-retained
 * @security: Provides `eval` support for replacement patterns. Which
 *   poses troubles for user-supplied input when paired with overly
 *   generic placeholders. This variant is only slightly stricter than
 *   the C implementation, but still susceptible to varexpression, quote
 *   breakouts and mundane exploits from unquoted capture placeholders.
 * @url: https://stackoverflow.com/q/15454220
 */
function preg_replace_eval($pattern, $replacement, $subject, $limit=-1) {
    # strip /e flag
    $pattern = preg_replace('/(\W[a-df-z]*)e([a-df-z]*)$/i', '$1$2', $pattern);
    # warn about most blatant misuses at least
    if (preg_match('/\(\.[+*]/', $pattern)) {
        trigger_error("preg_replace_eval(): regex contains (.*) or (.+) placeholders, which easily causes security issues for unconstrained/user input in the replacement expression. Transform your code to use preg_replace_callback() with a sane replacement callback!");
    }
    # run preg_replace with eval-callback
    return preg_replace_callback(
        $pattern,
        function ($matches) use ($replacement) {
            # substitute $1/$2/… with literals from $matches[]
            $repl = preg_replace_callback(
                '/(?<!\\\\)(?:[$]|\\\\)(\d+)/',
                function ($m) use ($matches) {
                    if (!isset($matches[$m[1]])) { trigger_error("No capture group for '$m[0]' eval placeholder"); }
                    return addcslashes($matches[$m[1]], '\"\'\`\$\\\0'); # additionally escapes '$' and backticks
                },
                $replacement
            );
            # run the replacement expression
            return eval("return $repl;");
        },
        $subject,
        $limit
    );
}

In essence, you just include that function in your codebase, and edit preg_replace to preg_replace_eval wherever the /e flag was used.

Pros and cons:

  • Really just tested with a few samples from Stack Overflow.
  • Does only support the easy cases (function calls, not variable lookups).
  • Contains a few more restrictions and advisory notices.
  • Will yield dislocated and less comprehensible errors for expression failures.
  • However is still a usable temporary solution and doesn't complicate a proper transition to preg_replace_callback.
  • And the license comment is just meant to deter people from overusing or spreading this too far.

Replacement code generator

Now this is somewhat redundant. But might help those users who are still overwhelmed with manually restructuring their code to preg_replace_callback. While this is effectively more time consuming, a code generator has less trouble to expand the /e replacement string into an expression. It's a very unremarkable conversion, but likely suffices for the most prevalent examples.

To use this function, edit any broken preg_replace call into preg_replace_eval_replacement and run it once. This will print out the according preg_replace_callback block to be used in its place.

/**
 * Use once to generate a crude preg_replace_callback() substitution. Might often
 * require additional changes in the `return …;` expression. You'll also have to
 * refit the variable names for input/output obviously.
 *
 * >>>  preg_replace_eval_replacement("/\w+/", 'strtopupper("$1")', $ignored);
 */
function preg_replace_eval_replacement($pattern, $replacement, $subjectvar="IGNORED") {
    $pattern = preg_replace('/(\W[a-df-z]*)e([a-df-z]*)$/i', '$1$2', $pattern);
    $replacement = preg_replace_callback('/[\'\"]?(?<!\\\\)(?:[$]|\\\\)(\d+)[\'\"]?/', function ($m) { return "\$m[{$m[1]}]"; }, $replacement);
    $ve = "var_export";
    $bt = debug_backtrace(0, 1)[0];
    print "<pre><code>
    #----------------------------------------------------
    # replace preg_*() call in '$bt[file]' line $bt[line] with:
    #----------------------------------------------------
    \$OUTPUT_VAR = preg_replace_callback(
        {$ve($pattern, TRUE)},
        function (\$m) {
            return {$replacement};
        },
        \$YOUR_INPUT_VARIABLE_GOES_HERE
    )
    #----------------------------------------------------
    </code></pre>\n";
}

Take in mind that mere copy&pasting is not programming. You'll have to adapt the generated code back to your actual input/output variable names, or usage context.

  • Specificially the $OUTPUT = assignment would have to go if the previous preg_replace call was used in an if.
  • It's best to keep temporary variables or the multiline code block structure though.

And the replacement expression may demand more readability improvements or rework.

  • For instance stripslashes() often becomes redundant in literal expressions.
  • Variable-scope lookups require a use or global reference for/within the callback.
  • Unevenly quote-enclosed "-$1-$2" capture references will end up syntactically broken by the plain transformation into "-$m[1]-$m[2].

The code output is merely a starting point. And yes, this would have been more useful as an online tool. This code rewriting approach (edit, run, edit, edit) is somewhat impractical. Yet could be more approachable to those who are accustomed to task-centric coding (more steps, more uncoveries). So this alternative might curb a few more duplicate questions.

Python equivalent to 'hold on' in Matlab

Just call plt.show() at the end:

import numpy as np
import matplotlib.pyplot as plt

plt.axis([0,50,60,80])
for i in np.arange(1,5):
    z = 68 + 4 * np.random.randn(50)
    zm = np.cumsum(z) / range(1,len(z)+1)
    plt.plot(zm)    

n = np.arange(1,51)
su = 68 + 4 / np.sqrt(n)
sl = 68 - 4 / np.sqrt(n)

plt.plot(n,su,n,sl)

plt.show()

How to read a PEM RSA private key from .NET

Check http://msdn.microsoft.com/en-us/library/dd203099.aspx

under Cryptography Application Block.

Don't know if you will get your answer, but it's worth a try.

Edit after Comment.

Ok then check this code.

using System.Security.Cryptography;


public static string DecryptEncryptedData(stringBase64EncryptedData, stringPathToPrivateKeyFile) { 
    X509Certificate2 myCertificate; 
    try{ 
        myCertificate = new X509Certificate2(PathToPrivateKeyFile); 
    } catch{ 
        throw new CryptographicException("Unable to open key file."); 
    } 

    RSACryptoServiceProvider rsaObj; 
    if(myCertificate.HasPrivateKey) { 
         rsaObj = (RSACryptoServiceProvider)myCertificate.PrivateKey; 
    } else 
        throw new CryptographicException("Private key not contained within certificate."); 

    if(rsaObj == null) 
        return String.Empty; 

    byte[] decryptedBytes; 
    try{ 
        decryptedBytes = rsaObj.Decrypt(Convert.FromBase64String(Base64EncryptedData), false); 
    } catch { 
        throw new CryptographicException("Unable to decrypt data."); 
    } 

    //    Check to make sure we decrpyted the string 
   if(decryptedBytes.Length == 0) 
        return String.Empty; 
    else 
        return System.Text.Encoding.UTF8.GetString(decryptedBytes); 
} 

Implement Validation for WPF TextBoxes

When it comes to Muhammad Mehdi's answer, it is better to do:

private void salary_texbox_PreviewTextInput(object sender, TextCompositionEventArgs e)
{
     Regex regex = new Regex ( "[^0-9]+" );
     if(regex.IsMatch(e.Text))
     {
         MessageBox.Show("Error");
     }
}

Because when comparing with the TextCompositionEventArgs it gets also the last character, while with the textbox.Text it does not. With textbox, the error will show after next inserted character.

SQLAlchemy default DateTime

You likely want to use onupdate=datetime.now so that UPDATEs also change the last_updated field.

SQLAlchemy has two defaults for python executed functions.

  • default sets the value on INSERT, only once
  • onupdate sets the value to the callable result on UPDATE as well.

What causes a java.lang.StackOverflowError

What actually causes a java.lang.StackOverflowError is typically unintentional recursion. For me it's often when I intended to call a super method for the overidden method. Such as in this case:

public class Vehicle {
    public void accelerate(float acceleration, float maxVelocity) {
        // set the acceleration
    }
}

public class SpaceShip extends Vehicle {
    @Override
    public void accelerate(float acceleration, float maxVelocity) {
        // update the flux capacitor and call super.accelerate
        // oops meant to call super.accelerate(acceleration, maxVelocity);
        // but accidentally wrote this instead. A StackOverflow is in our future.
        this.accelerate(acceleration, maxVelocity); 
    }
}

First, it's useful to know what happens behind the scenes when we call a function. The arguments and the address of where the method was called is pushed on the stack (see http://en.wikipedia.org/wiki/Stack_(abstract_data_type)#Runtime_memory_management) so that the called method can access the arguments and so that when the called method is completed, execution can continue after the call. But since we are calling this.accelerate(acceleration, maxVelocity) recursively (recursion is loosely when a method calls itself. For more info see http://en.wikipedia.org/wiki/Recursion_(computer_science)) we are in a situation known as infinite recursion and we keep piling the arguments and return address on the call stack. Since the call stack is finite in size, we eventually run out of space. The running out of space on the call stack is known as overflow. This is because we are trying to use more stack space than we have and the data literally overflows the stack. In the Java programming language, this results in the runtime exception java.lang.StackOverflow and will immediately halt the program.

The above example is somewhat simplified (although it happens to me more than I'd like to admit.) The same thing can happen in a more round about way making it a bit harder to track down. However, in general, the StackOverflow is usually pretty easy to resolve, once it occurs.

In theory, it is also possible to have a stack overflow without recursion, but in practice, it would appear to be a fairly rare event.

Sorting objects by property values

Example.

This runs on cscript.exe, on windows.

// define the Car class
(function() {
    // makeClass - By John Resig (MIT Licensed)
    // Allows either new User() or User() to be employed for construction.
    function makeClass(){
        return function(args){
            if ( this instanceof arguments.callee ) {
                if ( typeof this.init == "function" )
                    this.init.apply( this, (args && args.callee) ? args : arguments );
            } else
                return new arguments.callee( arguments );
        };
    }

    Car = makeClass();

    Car.prototype.init = function(make, model, price, topSpeed, weight) {
        this.make = make;
        this.model = model;
        this.price = price;
        this.weight = weight;
        this.topSpeed = topSpeed;
    };
})();


// create a list of cars
var autos = [
    new Car("Chevy", "Corvair", 1800, 88, 2900),
    new Car("Buick", "LeSabre", 31000, 138, 3700),
    new Car("Toyota", "Prius", 24000, 103, 3200),
    new Car("Porsche", "911", 92000, 155, 3100),
    new Car("Mercedes", "E500", 67000, 145, 3800),
    new Car("VW", "Passat", 31000, 135, 3700)
];

// a list of sorting functions
var sorters = {
    byWeight : function(a,b) {
        return (a.weight - b.weight);
    },
    bySpeed : function(a,b) {
        return (a.topSpeed - b.topSpeed);
    },
    byPrice : function(a,b) {
        return (a.price - b.price);
    },
    byModelName : function(a,b) {
        return ((a.model < b.model) ? -1 : ((a.model > b.model) ? 1 : 0));
    },
    byMake : function(a,b) {
        return ((a.make < b.make) ? -1 : ((a.make > b.make) ? 1 : 0));
    }
};

function say(s) {WScript.Echo(s);}

function show(title)
{
    say ("sorted by: "+title);
    for (var i=0; i < autos.length; i++) {
        say("  " + autos[i].model);
    }
    say(" ");
}

autos.sort(sorters.byWeight);
show("Weight");

autos.sort(sorters.byModelName);
show("Name");

autos.sort(sorters.byPrice);
show("Price");

You can also make a general sorter.

var byProperty = function(prop) {
    return function(a,b) {
        if (typeof a[prop] == "number") {
            return (a[prop] - b[prop]);
        } else {
            return ((a[prop] < b[prop]) ? -1 : ((a[prop] > b[prop]) ? 1 : 0));
        }
    };
};

autos.sort(byProperty("topSpeed"));
show("Top Speed");

Singleton with Arguments in Java

I think you need something like a factory to have objects with various parameters instantiated and reused. It could be implemented by using a synchronized HashMap or ConcurrentHashMap map a parameter (an Integer for an example) to your 'singleton' parameterizable class.

Although you might get to the point where you should use regular, non-singleton classes instead (for example needing 10.000 differently parametrized singleton).

Here is an example for such store:

public final class UsefulObjFactory {

    private static Map<Integer, UsefulObj> store =
        new HashMap<Integer, UsefulObj>();

    public static final class UsefulObj {
        private UsefulObj(int parameter) {
            // init
        }
        public void someUsefulMethod() {
            // some useful operation
        }
    }

    public static UsefulObj get(int parameter) {
        synchronized (store) {
            UsefulObj result = store.get(parameter);
            if (result == null) {
                result = new UsefulObj(parameter);
                store.put(parameter, result);
            }
            return result;
        }
    }
}

To push it even further, the Java enums can be also considered (or used as) parametrized singletons, although allowing only a fixed number static variants.

However, if you need a distributed1 solution, consider some lateral caching solution. For example: EHCache, Terracotta, etc.

1 in the sense of spanning multiple VMs on probably multiple computers.

Return a "NULL" object if search result not found

There are several possible answers here. You want to return something that might exist. Here are some options, ranging from my least preferred to most preferred:

  • Return by reference, and signal can-not-find by exception.

    Attr& getAttribute(const string& attribute_name) const 
    {
       //search collection
       //if found at i
            return attributes[i];
       //if not found
            throw no_such_attribute_error;
    }

It's likely that not finding attributes is a normal part of execution, and hence not very exceptional. The handling for this would be noisy. A null value cannot be returned because it's undefined behaviour to have null references.

  • Return by pointer

    Attr* getAttribute(const string& attribute_name) const 
    {
       //search collection
       //if found at i
            return &attributes[i];
       //if not found
            return nullptr;
    }

It's easy to forget to check whether a result from getAttribute would be a non-NULL pointer, and is an easy source of bugs.

  • Use Boost.Optional

    boost::optional<Attr&> getAttribute(const string& attribute_name) const 
    {
       //search collection
       //if found at i
            return attributes[i];
       //if not found
            return boost::optional<Attr&>();
    }

A boost::optional signifies exactly what is going on here, and has easy methods for inspecting whether such an attribute was found.


Side note: std::optional was recently voted into C++17, so this will be a "standard" thing in the near future.

How do I put variables inside javascript strings?

Do that:

s = 'hello ' + my_name + ', how are you doing'

Update

With ES6, you could also do this:

s = `hello ${my_name}, how are you doing`

ALTER TABLE, set null in not null column, PostgreSQL 9.1

Execute the command in this format

ALTER TABLE tablename ALTER COLUMN columnname SET NOT NULL;

for setting the column to not null.

How to fetch data from local JSON file on react native?

For ES6/ES2015 you can import directly like:

// example.json
{
    "name": "testing"
}


// ES6/ES2015
// app.js
import * as data from './example.json';
const word = data.name;
console.log(word); // output 'testing'

If you use typescript, you may declare json module like:

// tying.d.ts
declare module "*.json" {
    const value: any;
    export default value;
}

Node.js ES6 classes with require

Yes, your example would work fine.

As for exposing your classes, you can export a class just like anything else:

class Animal {...}
module.exports = Animal;

Or the shorter:

module.exports = class Animal {

};

Once imported into another module, then you can treat it as if it were defined in that file:

var Animal = require('./Animal');

class Cat extends Animal {
    ...
}

Regular expression to match balanced parentheses

This is the definitive regex:

\(
(?<arguments> 
(  
  ([^\(\)']*) |  
  (\([^\(\)']*\)) |
  '(.*?)'

)*
)
\)

Example:

input: ( arg1, arg2, arg3, (arg4), '(pip' )

output: arg1, arg2, arg3, (arg4), '(pip'

note that the '(pip' is correctly managed as string. (tried in regulator: http://sourceforge.net/projects/regulator/)

Scanner is skipping nextLine() after using next() or nextFoo()?

Why not use a new Scanner for every reading? Like below. With this approach you will not confront your problem.

int i = new Scanner(System.in).nextInt();

JSON Structure for List of Objects

The second is almost correct:

{
    "foos" : [{
        "prop1":"value1",
        "prop2":"value2"
    }, {
        "prop1":"value3", 
        "prop2":"value4"
    }]
}

How to split elements of a list?

Try iterating through each element of the list, then splitting it at the tab character and adding it to a new list.

for i in list:
    newList.append(i.split('\t')[0])

How can I read and parse CSV files in C++?

If you don't want to deal with including boost in your project (it is considerably large if all you are going to use it for is CSV parsing...)

I have had luck with the CSV parsing here:

http://www.zedwood.com/article/112/cpp-csv-parser

It handles quoted fields - but does not handle inline \n characters (which is probably fine for most uses).

Warning message: In `...` : invalid factor level, NA generated

I have got similar issue which data retrieved from .xlsx file. Unfortunately, I could not find the proper answer here. I handled it on my own with dplyr as below which might help others:

#install.packages("xlsx")
library(xlsx)
extracted_df <- read.xlsx("test.xlsx", sheetName='Sheet1', stringsAsFactors=FALSE)
# Replace all NAs in a data frame with "G" character
extracted_df[is.na(extracted_df)] <- "G"

However, I could not handle it with the readxl package which does not have similar parameter to the stringsAsFactors. For the reason, I have moved to the xlsx package.

Execute Stored Procedure from a Function

Here is another possible workaround:

if exists (select * from master..sysservers where srvname = 'loopback')
    exec sp_dropserver 'loopback'
go
exec sp_addlinkedserver @server = N'loopback', @srvproduct = N'', @provider = N'SQLOLEDB', @datasrc = @@servername
go

create function testit()
    returns int
as
begin
    declare @res int;
    select @res=count(*) from openquery(loopback, 'exec sp_who');
    return @res
end
go

select dbo.testit()

It's not so scary as xp_cmdshell but also has too many implications for practical use.

svn : how to create a branch from certain revision of trunk

$ svn copy http://svn.example.com/repos/calc/trunk@192 \
   http://svn.example.com/repos/calc/branches/my-calc-branch \
   -m "Creating a private branch of /calc/trunk."

Where 192 is the revision you specify

You can find this information from the SVN Book, specifically here on the page about svn copy

Add JsonArray to JsonObject

Your list:

List<MyCustomObject> myCustomObjectList;

Your JSONArray:

// Don't need to loop through it. JSONArray constructor do it for you.
new JSONArray(myCustomObjectList)

Your response:

return new JSONObject().put("yourCustomKey", new JSONArray(myCustomObjectList));

Your post/put http body request would be like this:

    {
        "yourCustomKey: [
           {
               "myCustomObjectProperty": 1
           },
           {
               "myCustomObjectProperty": 2
           }
        ]
    }

How to create an integer-for-loop in Ruby?

x.times do |i|
    something(i+1)
end

How to execute Python code from within Visual Studio Code

If you are using the latest version of Visual Studio Code (version 1.21.1). The task.json format has changed, see here. So the answer by Fenton and by python_starter may no longer be valid.

Before starting configuration

Before you start configuring Visual Studio Code for running your Python file.

  • Make sure that you have installed Python and added its executable to your system PATH.
  • You must set the folder where your python source file resides as your working folder (go to File -> Open Folder to set your working folder).

Configuration steps

Now you can configure the task. The following steps will help you run your python file correctly:

  1. use Ctrl+Shift+P and input task, you will see a list of options, select Tasks: Configure Task.

Enter image description here

  1. You will then be prompted create task.json from template, choose this option, and you will be prompted to choose from a list of options. Choose Others.

Enter image description here

  1. Then in the opened task.json file, use the following settings:

     {
     "version": "2.0.0",
     "tasks": [
         {
             "label": "run this script",
             "type": "shell",
             "command": "python",
             "args": [
                 "${file}"
             ],
             "problemMatcher": []
         }
     ]
     }
    

In the above settings, you can give a meaningful label to this task. For example, run python.

  1. Go to the Tasks menu and click Run Task. You will be prompted to choose the task. Just choose the newly created run this script task. You will see the result in the TERMINAL tab.

Enter image description here

Enter image description here

For a more complete tutorial about task configuration, go to the Visual Studio Code official documentation.

NULL values inside NOT IN clause

Whenever you use NULL you are really dealing with a Three-Valued logic.

Your first query returns results as the WHERE clause evaluates to:

    3 = 1 or 3 = 2 or 3 = 3 or 3 = null
which is:
    FALSE or FALSE or TRUE or UNKNOWN
which evaluates to 
    TRUE

The second one:

    3 <> 1 and 3 <> 2 and 3 <> null
which evaluates to:
    TRUE and TRUE and UNKNOWN
which evaluates to:
    UNKNOWN

The UNKNOWN is not the same as FALSE you can easily test it by calling:

select 'true' where 3 <> null
select 'true' where not (3 <> null)

Both queries will give you no results

If the UNKNOWN was the same as FALSE then assuming that the first query would give you FALSE the second would have to evaluate to TRUE as it would have been the same as NOT(FALSE).
That is not the case.

There is a very good article on this subject on SqlServerCentral.

The whole issue of NULLs and Three-Valued Logic can be a bit confusing at first but it is essential to understand in order to write correct queries in TSQL

Another article I would recommend is SQL Aggregate Functions and NULL.

How can I make an EXE file from a Python program?

Also known as Frozen Binaries but not the same as as the output of a true compiler- they run byte code through a virtual machine (PVM). Run the same as a compiled program just larger because the program is being compiled along with the PVM. Py2exe can freeze standalone programs that use the tkinter, PMW, wxPython, and PyGTK GUI libraties; programs that use the pygame game programming toolkit; win32com client programs; and more. The Stackless Python system is a standard CPython implementation variant that does not save state on the C language call stack. This makes Python more easy to port to small stack architectures, provides efficient multiprocessing options, and fosters novel programming structures such as coroutines. Other systems of study that are working on future development: Pyrex is working on the Cython system, the Parrot project, the PyPy is working on replacing the PVM altogether, and of course the founder of Python is working with Google to get Python to run 5 times faster than C with the Unladen Swallow project. In short, py2exe is the easiest and Cython is more efficient for now until these projects improve the Python Virtual Machine (PVM) for standalone files.

how to get the cookies from a php curl into a variable

someone here may find it useful. hhb_curl_exec2 works pretty much like curl_exec, but arg3 is an array which will be populated with the returned http headers (numeric index), and arg4 is an array which will be populated with the returned cookies ($cookies["expires"]=>"Fri, 06-May-2016 05:58:51 GMT"), and arg5 will be populated with... info about the raw request made by curl.

the downside is that it requires CURLOPT_RETURNTRANSFER to be on, else it error out, and that it will overwrite CURLOPT_STDERR and CURLOPT_VERBOSE, if you were already using them for something else.. (i might fix this later)

example of how to use it:

<?php
header("content-type: text/plain;charset=utf8");
$ch=curl_init();
$headers=array();
$cookies=array();
$debuginfo="";
$body="";
curl_setopt($ch,CURLOPT_SSL_VERIFYPEER,false);
curl_setopt($ch,CURLOPT_RETURNTRANSFER,true);
$body=hhb_curl_exec2($ch,'https://www.youtube.com/',$headers,$cookies,$debuginfo);
var_dump('$cookies:',$cookies,'$headers:',$headers,'$debuginfo:',$debuginfo,'$body:',$body);

and the function itself..

function hhb_curl_exec2($ch, $url, &$returnHeaders = array(), &$returnCookies = array(), &$verboseDebugInfo = "")
{
    $returnHeaders    = array();
    $returnCookies    = array();
    $verboseDebugInfo = "";
    if (!is_resource($ch) || get_resource_type($ch) !== 'curl') {
        throw new InvalidArgumentException('$ch must be a curl handle!');
    }
    if (!is_string($url)) {
        throw new InvalidArgumentException('$url must be a string!');
    }
    $verbosefileh = tmpfile();
    $verbosefile  = stream_get_meta_data($verbosefileh);
    $verbosefile  = $verbosefile['uri'];
    curl_setopt($ch, CURLOPT_VERBOSE, 1);
    curl_setopt($ch, CURLOPT_STDERR, $verbosefileh);
    curl_setopt($ch, CURLOPT_HEADER, 1);
    $html             = hhb_curl_exec($ch, $url);
    $verboseDebugInfo = file_get_contents($verbosefile);
    curl_setopt($ch, CURLOPT_STDERR, NULL);
    fclose($verbosefileh);
    unset($verbosefile, $verbosefileh);
    $headers       = array();
    $crlf          = "\x0d\x0a";
    $thepos        = strpos($html, $crlf . $crlf, 0);
    $headersString = substr($html, 0, $thepos);
    $headerArr     = explode($crlf, $headersString);
    $returnHeaders = $headerArr;
    unset($headersString, $headerArr);
    $htmlBody = substr($html, $thepos + 4); //should work on utf8/ascii headers... utf32? not so sure..
    unset($html);
    //I REALLY HOPE THERE EXIST A BETTER WAY TO GET COOKIES.. good grief this looks ugly..
    //at least it's tested and seems to work perfectly...
    $grabCookieName = function($str)
    {
        $ret = "";
        $i   = 0;
        for ($i = 0; $i < strlen($str); ++$i) {
            if ($str[$i] === ' ') {
                continue;
            }
            if ($str[$i] === '=') {
                break;
            }
            $ret .= $str[$i];
        }
        return urldecode($ret);
    };
    foreach ($returnHeaders as $header) {
        //Set-Cookie: crlfcoookielol=crlf+is%0D%0A+and+newline+is+%0D%0A+and+semicolon+is%3B+and+not+sure+what+else
        /*Set-Cookie:ci_spill=a%3A4%3A%7Bs%3A10%3A%22session_id%22%3Bs%3A32%3A%22305d3d67b8016ca9661c3b032d4319df%22%3Bs%3A10%3A%22ip_address%22%3Bs%3A14%3A%2285.164.158.128%22%3Bs%3A10%3A%22user_agent%22%3Bs%3A109%3A%22Mozilla%2F5.0+%28Windows+NT+6.1%3B+WOW64%29+AppleWebKit%2F537.36+%28KHTML%2C+like+Gecko%29+Chrome%2F43.0.2357.132+Safari%2F537.36%22%3Bs%3A13%3A%22last_activity%22%3Bi%3A1436874639%3B%7Dcab1dd09f4eca466660e8a767856d013; expires=Tue, 14-Jul-2015 13:50:39 GMT; path=/
        Set-Cookie: sessionToken=abc123; Expires=Wed, 09 Jun 2021 10:18:14 GMT;
        //Cookie names cannot contain any of the following '=,; \t\r\n\013\014'
        //
        */
        if (stripos($header, "Set-Cookie:") !== 0) {
            continue;
            /**/
        }
        $header = trim(substr($header, strlen("Set-Cookie:")));
        while (strlen($header) > 0) {
            $cookiename                 = $grabCookieName($header);
            $returnCookies[$cookiename] = '';
            $header                     = substr($header, strlen($cookiename) + 1); //also remove the = 
            if (strlen($header) < 1) {
                break;
            }
            ;
            $thepos = strpos($header, ';');
            if ($thepos === false) { //last cookie in this Set-Cookie.
                $returnCookies[$cookiename] = urldecode($header);
                break;
            }
            $returnCookies[$cookiename] = urldecode(substr($header, 0, $thepos));
            $header                     = trim(substr($header, $thepos + 1)); //also remove the ;
        }
    }
    unset($header, $cookiename, $thepos);
    return $htmlBody;
}

function hhb_curl_exec($ch, $url)
{
    static $hhb_curl_domainCache = "";
    //$hhb_curl_domainCache=&$this->hhb_curl_domainCache;
    //$ch=&$this->curlh;
    if (!is_resource($ch) || get_resource_type($ch) !== 'curl') {
        throw new InvalidArgumentException('$ch must be a curl handle!');
    }
    if (!is_string($url)) {
        throw new InvalidArgumentException('$url must be a string!');
    }

    $tmpvar = "";
    if (parse_url($url, PHP_URL_HOST) === null) {
        if (substr($url, 0, 1) !== '/') {
            $url = $hhb_curl_domainCache . '/' . $url;
        } else {
            $url = $hhb_curl_domainCache . $url;
        }
    }
    ;

    curl_setopt($ch, CURLOPT_URL, $url);
    $html = curl_exec($ch);
    if (curl_errno($ch)) {
        throw new Exception('Curl error (curl_errno=' . curl_errno($ch) . ') on url ' . var_export($url, true) . ': ' . curl_error($ch));
        // echo 'Curl error: ' . curl_error($ch);
    }
    if ($html === '' && 203 != ($tmpvar = curl_getinfo($ch, CURLINFO_HTTP_CODE)) /*203 is "success, but no output"..*/ ) {
        throw new Exception('Curl returned nothing for ' . var_export($url, true) . ' but HTTP_RESPONSE_CODE was ' . var_export($tmpvar, true));
    }
    ;
    //remember that curl (usually) auto-follows the "Location: " http redirects..
    $hhb_curl_domainCache = parse_url(curl_getinfo($ch, CURLINFO_EFFECTIVE_URL), PHP_URL_HOST);
    return $html;
}

How to map a composite key with JPA and Hibernate?

Assuming you have the following database tables:

Database tables

First, you need to create the @Embeddable holding the composite identifier:

@Embeddable
public class EmployeeId implements Serializable {
 
    @Column(name = "company_id")
    private Long companyId;
 
    @Column(name = "employee_number")
    private Long employeeNumber;
 
    public EmployeeId() {
    }
 
    public EmployeeId(Long companyId, Long employeeId) {
        this.companyId = companyId;
        this.employeeNumber = employeeId;
    }
 
    public Long getCompanyId() {
        return companyId;
    }
 
    public Long getEmployeeNumber() {
        return employeeNumber;
    }
 
    @Override
    public boolean equals(Object o) {
        if (this == o) return true;
        if (!(o instanceof EmployeeId)) return false;
        EmployeeId that = (EmployeeId) o;
        return Objects.equals(getCompanyId(), that.getCompanyId()) &&
                Objects.equals(getEmployeeNumber(), that.getEmployeeNumber());
    }
 
    @Override
    public int hashCode() {
        return Objects.hash(getCompanyId(), getEmployeeNumber());
    }
}

With this in place, we can map the Employee entity which uses the composite identifier by annotating it with @EmbeddedId:

@Entity(name = "Employee")
@Table(name = "employee")
public class Employee {
 
    @EmbeddedId
    private EmployeeId id;
 
    private String name;
 
    public EmployeeId getId() {
        return id;
    }
 
    public void setId(EmployeeId id) {
        this.id = id;
    }
 
    public String getName() {
        return name;
    }
 
    public void setName(String name) {
        this.name = name;
    }
}

The Phone entity which has a @ManyToOne association to Employee, needs to reference the composite identifier from the parent class via two @JoinColumnmappings:

@Entity(name = "Phone")
@Table(name = "phone")
public class Phone {
 
    @Id
    @Column(name = "`number`")
    private String number;
 
    @ManyToOne
    @JoinColumns({
        @JoinColumn(
            name = "company_id",
            referencedColumnName = "company_id"),
        @JoinColumn(
            name = "employee_number",
            referencedColumnName = "employee_number")
    })
    private Employee employee;
 
    public Employee getEmployee() {
        return employee;
    }
 
    public void setEmployee(Employee employee) {
        this.employee = employee;
    }
 
    public String getNumber() {
        return number;
    }
 
    public void setNumber(String number) {
        this.number = number;
    }
}

Getting the class of the element that fired an event using JQuery

Try:

$(document).ready(function() {
    $("a").click(function(event) {
       alert(event.target.id+" and "+$(event.target).attr('class'));
    });
});

What's the difference between display:inline-flex and display:flex?

Using two-value display syntax instead, for clarity

The display CSS property in fact sets two things at once: the outer display type, and the inner display type. The outer display type affects how the element (which acts as a container) is displayed in its context. The inner display type affects how the children of the element (or the children of the container) are laid out.

If you use the two-value display syntax, which is only supported in some browsers like Firefox, the difference between the two is much more obvious:

  • display: block is equivalent to display: block flow
  • display: inline is equivalent to display: inline flow
  • display: flex is equivalent to display: block flex
  • display: inline-flex is equivalent to display: inline flex
  • display: grid is equivalent to display: block grid
  • display: inline-grid is equivalent to display: inline grid

Outer display type: block or inline:

An element with the outer display type of block will take up the whole width available to it, like <div> does. An element with the outer display type of inline will only take up the width that it needs, with wrapping, like <span> does.

Inner display type: flow, flex or grid:

The inner display type flow is the default inner display type when flex or grid is not specified. It is the way of laying out children elements that we are used to in a <p> for instance. flex and grid are new ways of laying out children that each deserve their own post.

Conclusion:

The difference between display: flex and display: inline-flex is the outer display type, the first's outer display type is block, and the second's outer display type is inline. Both of them have the inner display type of flex.

References:

How to generate unique id in MySQL?

You could use Twitter's snowflake.

In short, it generates a unique id based on time, server id and a sequence. It generates a 64-bit value so it is pretty small and it fits in an INT64. It also allows for sorting values correctly.

https://developer.twitter.com/en/docs/basics/twitter-ids

In sum, it allows multiple servers, highly concurrency, sorting value and all of them in 64 bits.

Here it is the implementation for MySQL

https://github.com/EFTEC/snowflake-mysql

It consists of a function and a table.

SQLAlchemy: print the actual query

So building on @zzzeek's comments on @bukzor's code I came up with this to easily get a "pretty-printable" query:

def prettyprintable(statement, dialect=None, reindent=True):
    """Generate an SQL expression string with bound parameters rendered inline
    for the given SQLAlchemy statement. The function can also receive a
    `sqlalchemy.orm.Query` object instead of statement.
    can 

    WARNING: Should only be used for debugging. Inlining parameters is not
             safe when handling user created data.
    """
    import sqlparse
    import sqlalchemy.orm
    if isinstance(statement, sqlalchemy.orm.Query):
        if dialect is None:
            dialect = statement.session.get_bind().dialect
        statement = statement.statement
    compiled = statement.compile(dialect=dialect,
                                 compile_kwargs={'literal_binds': True})
    return sqlparse.format(str(compiled), reindent=reindent)

I personally have a hard time reading code which is not indented so I've used sqlparse to reindent the SQL. It can be installed with pip install sqlparse.

How to actually search all files in Visual Studio

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

enter image description here

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

enter image description here

Check box size change with CSS

Try this

<input type="checkbox" style="zoom:1.5;" />
/* The value 1.5 i.e., the size of checkbox will be increased by 0.5% */

How to Implement Custom Table View Section Headers and Footers with Storyboard

The solution I came up with is basically the same solution used before the introduction of storyboards.

Create a new, empty interface class file. Drag a UIView on to the canvas, layout as desired.

Load the nib manually, assign to the appropriate header/footer section in viewForHeaderInSection or viewForFooterInSection delegate methods.

I had hope that Apple simplified this scenario with storyboards and kept looking for a better or simpler solution. For example custom table headers and footers are straight forward to add.

How to get current domain name in ASP.NET

HttpContext.Current.Request.Url.Host is returning the correct values. If you run it on www.somedomainname.com it will give you www.somedomainname.com. If you want to get the 5858 as well you need to use

HttpContext.Current.Request.Url.Port 

PHP Pass variable to next page

There are three method to pass value in php.

  • By post
  • By get
  • By making session variable

These three method are used for different purpose.For example if we want to receive our value on next page then we can use 'post' ($_POST) method as:-

$a=$_POST['field-name'];

If we require the value of variable on more than one page than we can use session variable as:-

$a=$_SESSION['field-name];

Before using this Syntax for creating SESSION variable we first have to add this tag at the very beginning of our php page

session_start(); 

GET method are generally used to print data on same page which used to take input from user. Its syntax is as:

$a=$_GET['field-name'];

POST method are generally consume more secure than GET because when we use Get method than it can display the data in URL bar.If the data is more sensitive data like password then it can be inggeris.

Singleton design pattern vs Singleton beans in Spring container

"singleton" in spring is using bean factory get instance, then cache it; which singleton design pattern is strictly, the instance can only be retrieved from static get method, and the object can never be publicly instantiated.

Android button with icon and text

For anyone looking to do this dynamically then setCompoundDrawables(Drawable left, Drawable top, Drawable right, Drawable bottom) on the buttons object will assist.

Sample

Button search = (Button) findViewById(R.id.yoursearchbutton);
search.setCompoundDrawables('your_drawable',null,null,null);

Convert a number into a Roman Numeral in javaScript

This solution runs only one loop and has the minimun object to map numerals to roman letters

function RomantoNumeral(r){
  let result = 0,
      keys = {M:1000, D:500, C:100, L:50, C:100, L:50, X:10, V:5, I:1},
      order = Object.keys(keys),
      rom = Array.from(r) 

  rom.forEach((e, i)=>{
    if( i  < rom.length -1 && order.indexOf(e) > order.indexOf(rom[i+1])){
      result -= keys[e]
    } else {
      result +=keys[e]
    }
  })  
  return result
}

RomantoNumeral('MMDCCCXXXVII') #2837

How do I delete NuGet packages that are not referenced by any project in my solution?

If you want to delete/uninstall Nuget package which is applied to multiple projects in your solutions then go to:

  1. Tools-> Nuget Package Manager -> Manage Nuget Packages for Solution

  2. In the left column where is 'Installed packages' select 'All', so you'll see a list of installed packages and Manage button across them.

  3. Select Manage button and you'll get a pop out, deselect the checkbox across project name and Ok it

The rest of the work Package Manager will do it for you.

jQuery Data vs Attr?

You can use data-* attribute to embed custom data. The data-* attributes gives us the ability to embed custom data attributes on all HTML elements.

jQuery .data() method allows you to get/set data of any type to DOM elements in a way that is safe from circular references and therefore from memory leaks.

jQuery .attr() method get/set attribute value for only the first element in the matched set.

Example:

<span id="test" title="foo" data-kind="primary">foo</span>

$("#test").attr("title");
$("#test").attr("data-kind");
$("#test").data("kind");
$("#test").data("value", "bar");

get UTC timestamp in python with datetime

If input datetime object is in UTC:

>>> dt = datetime(2008, 1, 1, 0, 0, 0, 0)
>>> timestamp = (dt - datetime(1970, 1, 1)).total_seconds()
1199145600.0

Note: it returns float i.e., microseconds are represented as fractions of a second.

If input date object is in UTC:

>>> from datetime import date
>>> utc_date = date(2008, 1, 1)
>>> timestamp = (utc_date.toordinal() - date(1970, 1, 1).toordinal()) * 24*60*60
1199145600

See more details at Converting datetime.date to UTC timestamp in Python.

How to create a showdown.js markdown extension

In your last block you have a comma after 'lang', followed immediately with a function. This is not valid json.

EDIT

It appears that the readme was incorrect. I had to to pass an array with the string 'twitter'.

var converter = new Showdown.converter({extensions: ['twitter']}); converter.makeHtml('whatever @meandave2020'); // output "<p>whatever <a href="http://twitter.com/meandave2020">@meandave2020</a></p>" 

I submitted a pull request to update this.

Search for string within text column in MySQL

you mean:

SELECT * FROM items WHERE items.xml LIKE '%123456%'

Can Mockito stub a method without regard to the argument?

when(
  fooDao.getBar(
    any(Bazoo.class)
  )
).thenReturn(myFoo);

or (to avoid nulls):

when(
  fooDao.getBar(
    (Bazoo)notNull()
  )
).thenReturn(myFoo);

Don't forget to import matchers (many others are available):

For Mockito 2.1.0 and newer:

import static org.mockito.ArgumentMatchers.*;

For older versions:

import static org.mockito.Matchers.*;

How to remove whitespace from a string in typescript?

Trim just removes the trailing and leading whitespace. Use .replace(/ /g, "") if there are just spaces to be replaced.

this.maintabinfo = this.inner_view_data.replace(/ /g, "").toLowerCase();

How to resolve git's "not something we can merge" error

This error suggest that the branch from where you want to merge changes (i.e. in you case branch-name) is not present in you local, so you should checkout the branch and fetch the local changes. Checkout to your master branch and fetch, then follow the below steps:

git checkout branch-name
git pull
git checkout new-branch-name
git merge branch-name

How to find out which processes are using swap space in Linux?

Since the year 2015 kernel patch that adds SwapPss (https://lore.kernel.org/patchwork/patch/570506/) one can finally get proportional swap count meaning that if a process has swapped a lot and then it forks, both forked processes will be reported to swap 50% each. And if either then forks, each process is counted 33% of the swapped pages so if you count all those swap usages together, you get real swap usage instead of value multiplied by process count.

In short:

(cd /proc; for pid in [0-9]*; do printf "%5s %6s %s\n" "$pid" "$(awk 'BEGIN{sum=0} /SwapPss:/{sum+=$2} END{print sum}' $pid/smaps)" "$(cat $pid/comm)"; done | sort -k2n,2 -k1n,1)

First column is pid, second column is swap usage in KiB and rest of the line is command being executed. Identical swap counts are sorted by pid.

Above may emit lines such as

awk: cmd. line:1: fatal: cannot open file `15407/smaps' for reading (No such file or directory)

which simply means that process with pid 15407 ended between seeing it in the list for /proc/ and reading the process smaps file. If that matters to you, simply add 2>/dev/null to the end. Note that you'll potentially lose any other possible diagnostics as well.

In real world example case, this changes other tools reporting ~40 MB swap usage for each apache child running on one server to actual usage of between 7-3630 KB really used per child.

Vertical alignment of text and icon in button

There is one rule that is set by font-awesome.css, which you need to override.

You should set overrides in your CSS files rather than inline, but essentially, the icon-ok class is being set to vertical-align: baseline; by default and which I've corrected here:

<button id="whatever" class="btn btn-large btn-primary" name="Continue" type="submit">
    <span>Continue</span>
    <i class="icon-ok" style="font-size:30px; vertical-align: middle;"></i>
</button>

Example here: http://jsfiddle.net/fPXFY/4/ and the output of which is:

enter image description here

I've downsized the font-size of the icon above in this instance to 30px, as it feels too big at 40px for the size of the button, but this is purely a personal viewpoint. You could increase the padding on the button to compensate if required:

<button id="whaever" class="btn btn-large btn-primary" style="padding: 20px;" name="Continue" type="submit">
    <span>Continue</span>
    <i class="icon-ok" style="font-size:30px; vertical-align: middle;"></i>
</button>

Producing: http://jsfiddle.net/fPXFY/5/ the output of which is:

enter image description here

What is the difference between user and kernel modes in operating systems?

A processor in a computer running Windows has two different modes: user mode and kernel mode. The processor switches between the two modes depending on what type of code is running on the processor. Applications run in user mode, and core operating system components run in kernel mode. While many drivers run in kernel mode, some drivers may run in user mode.

When you start a user-mode application, Windows creates a process for the application. The process provides the application with a private virtual address space and a private handle table. Because an application's virtual address space is private, one application cannot alter data that belongs to another application. Each application runs in isolation, and if an application crashes, the crash is limited to that one application. Other applications and the operating system are not affected by the crash.

In addition to being private, the virtual address space of a user-mode application is limited. A processor running in user mode cannot access virtual addresses that are reserved for the operating system. Limiting the virtual address space of a user-mode application prevents the application from altering, and possibly damaging, critical operating system data.

All code that runs in kernel mode shares a single virtual address space. This means that a kernel-mode driver is not isolated from other drivers and the operating system itself. If a kernel-mode driver accidentally writes to the wrong virtual address, data that belongs to the operating system or another driver could be compromised. If a kernel-mode driver crashes, the entire operating system crashes.

If you are a Windows user once go through this link you will get more.

Communication between user mode and kernel mode

window.close and self.close do not close the window in Chrome

I found a new way that works for me perfetly

var win = window.open("about:blank", "_self");
win.close();

Remove padding or margins from Google Charts

It's missing in the docs (I'm using version 43), but you can actually use the right and bottom property of the chart area:

var options = {
  chartArea:{
    left:10,
    right:10, // !!! works !!!
    bottom:20,  // !!! works !!!
    top:20,
    width:"100%",
    height:"100%"
  }
};

So it's possible to use full responsive width & height and prevent any axis labels or legends from being cropped.

Could not load file or assembly 'System.Net.Http.Formatting' or one of its dependencies. The system cannot find the path specified

VS2019: Tools -> Nuget Package Manager -> Package Manager Setting -> in Package Restore section, check 2 options. After that, go to project packages folder and delete all child folders inside (for no longer any error) Then Rebuild solution, Nuget will redownload all packages and project should run without any reference.

Is there a goto statement in Java?

The Java keyword list specifies the goto keyword, but it is marked as "not used".

It was in the original JVM (see answer by @VitaliiFedorenko), but then removed. It was probably kept as a reserved keyword in case it were to be added to a later version of Java.

If goto was not on the list, and it gets added to the language later on, existing code that used the word goto as an identifier (variable name, method name, etc...) would break. But because goto is a keyword, such code will not even compile in the present, and it remains possible to make it actually do something later on, without breaking existing code.

jQuery count child elements

You can use JavaScript (don't need jQuery)

document.querySelectorAll('#selected li').length;

PHP and MySQL Select a Single Value

  1. Don't use quotation in a field name or table name inside the query.

  2. After fetching an object you need to access object attributes/properties (in your case id) by attributes/properties name.

One note: please use mysqli_* or PDO since mysql_* deprecated. Here it is using mysqli:

session_start();
mysqli_report(MYSQLI_REPORT_ERROR | MYSQLI_REPORT_STRICT);
$link = new mysqli('localhost', 'username', 'password', 'db_name');
$link->set_charset('utf8mb4'); // always set the charset
$name = $_GET["username"];
$stmt = $link->prepare("SELECT id FROM Users WHERE username=? limit 1");
$stmt->bind_param('s', $name);
$stmt->execute();
$result = $stmt->get_result();
$value = $result->fetch_object();
$_SESSION['myid'] = $value->id;

Bonus tips: Use limit 1 for this type of scenario, it will save execution time :)

Properties order in Margin

There are three unique situations:

  • 4 numbers, e.g. Margin="a,b,c,d".
  • 2 numbers, e.g. Margin="a,b".
  • 1 number, e.g. Margin="a".

4 Numbers

If there are 4 numbers, then its left, top, right, bottom (a clockwise circle starting from the middle left margin). First number is always the "West" like "WPF":

<object Margin="left,top,right,bottom"/>

Example: if we use Margin="10,20,30,40" it generates:

enter image description here

2 Numbers

If there are 2 numbers, then the first is left & right margin thickness, the second is top & bottom margin thickness. First number is always the "West" like "WPF":

<object Margin="a,b"/> // Equivalent to Margin="a,b,a,b".

Example: if we use Margin="10,30", the left & right margin are both 10, and the top & bottom are both 30.

enter image description here

1 Number

If there is 1 number, then the number is repeated (its essentially a border thickness).

<object Margin="a"/> // Equivalent to Margin="a,a,a,a".

Example: if we use Margin="20" it generates:

enter image description here

Update 2020-05-27

Have been working on a large-scale WPF application for the past 5 years with over 100 screens. Part of a team of 5 WPF/C#/Java devs. We eventually settled on either using 1 number (for border thickness) or 4 numbers. We never use 2. It is consistent, and seems to be a good way to reduce cognitive load when developing.


The rule:

All width numbers start on the left (the "West" like "WPF") and go clockwise (if two numbers, only go clockwise twice, then mirror the rest).

Convert String to Uri

Java's parser in java.net.URI is going to fail if the URI isn't fully encoded to its standards. For example, try to parse: http://www.google.com/search?q=cat|dog. An exception will be thrown for the vertical bar.

urllib makes it easy to convert a string to a java.net.URI. It will pre-process and escape the URL.

assertEquals("http://www.google.com/search?q=cat%7Cdog",
    Urls.createURI("http://www.google.com/search?q=cat|dog").toString());

Reload nginx configuration

If your system has systemctl

sudo systemctl reload nginx

If your system supports service (using debian/ubuntu) try this

sudo service nginx reload

If not (using centos/fedora/etc) you can try the init script

sudo /etc/init.d/nginx reload

C# Break out of foreach loop after X number of items

int count = 0;
foreach (ListViewItem lvi in listView.Items)
{
    if(++count > 50) break;
}

What's the proper way to install pip, virtualenv, and distribute for Python?

There is no problem to do sudo python setup.py install, if you're sure it's what you want to do.

The difference is that it will use the site-packages directory of your OS as a destination for .py files to be copied.

so, if you want pip to be accessible os wide, that's probably the way to go. I do not say that others way are bad, but this is probably fair enough.

Breaking out of nested loops

In this particular case, you can merge the loops with a modern python (3.0 and probably 2.6, too) by using itertools.product.

I for myself took this as a rule of thumb, if you nest too many loops (as in, more than 2), you are usually able to extract one of the loops into a different method or merge the loops into one, as in this case.

How to change the length of a column in a SQL Server table via T-SQL

So, let's say you have this table:

CREATE TABLE YourTable(Col1 VARCHAR(10))

And you want to change Col1 to VARCHAR(20). What you need to do is this:

ALTER TABLE YourTable
ALTER COLUMN Col1 VARCHAR(20)

That'll work without problems since the length of the column got bigger. If you wanted to change it to VARCHAR(5), then you'll first gonna need to make sure that there are not values with more chars on your column, otherwise that ALTER TABLE will fail.

how to delete default values in text field using selenium?

For page object model -

 @FindBy(xpath="//foo")
   public WebElement textBox;

now in your function

 public void clearExistingText(String newText){
    textBox.clear();
    textBox.sendKeys(newText);
  }

for general selenium architecture -

driver.findElement(By.xpath("//yourxpath")).clear();
driver.findElement(By.xpath("//yourxpath")).sendKeys("newText");

Truststore and Keystore Definitions

  1. A keystore contains private keys. You only need this if you are a server, or if the server requires client authentication.

  2. A truststore contains CA certificates to trust. If your server’s certificate is signed by a recognized CA, the default truststore that ships with the JRE will already trust it (because it already trusts trustworthy CAs), so you don’t need to build your own, or to add anything to the one from the JRE.

Source

How can I record a Video in my Android App.?

The above example will work if you are using rear camera. If you are using front camera, you will have to adjust some things:

First off, you will need to add new permission in the manifest.

<uses-feature android:name="android.hardware.camera.front" android:required="false" />

In your initRecorder method, instead of

CamcorderProfile cpHigh = CamcorderProfile
                .get(CamcorderProfile.QUALITY_HIGH);
recorder.setProfile(cpHigh);

You need to use:

CamcorderProfile profile = CamcorderProfile.get(Camera.CameraInfo.CAMERA_FACING_FRONT, CamcorderProfile.QUALITY_LOW);
recorder.setProfile(profile);

because CamcorderProfile.QUALITY_HIGH is reserved for the rear camera.

You will also have to set the video size for mediarecorder as it is in your surface view.

Here is the full example of recording video from front camera with a small preview display:

Android.manifest

<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.RECORD_AUDIO" />
<uses-permission android:name="android.permission.CAMERA" />
<uses-feature android:name="android.hardware.camera" android:required="false" />
<uses-feature android:name="android.hardware.camera.front" android:required="false" />

activity_camera.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="CameraActivity">

    <SurfaceView
        android:layout_width="200dp"
        android:layout_height="wrap_content"
        android:id="@+id/surfaceView"/>

    <Button
        android:layout_width="100dp"
        android:layout_height="100dp"
        android:text="REC"
        android:id="@+id/btnRecord"
        android:layout_alignParentBottom="true"
        android:layout_marginBottom="25dp" />
</RelativeLayout>

CameraActivity.java

public class SongVideoActivity extends BaseActivity implements SurfaceHolder.Callback {

    private int mCameraContainerWidth = 0;
    private SurfaceView mSurfaceView = null;
    private SurfaceHolder mSurfaceHolder = null;

    private Camera mCamera = null;
    private boolean mIsRecording = false;

    private int mPreviewHeight;
    private int mPreviewWidth;

    MediaRecorder mRecorder;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_song_video);

        Thread.setDefaultUncaughtExceptionHandler(new Thread.UncaughtExceptionHandler() {
            @Override
            public void uncaughtException(Thread thread, Throwable ex) {
                releaseMediaRecorder();
                releaseCamera();
            }
        });

        mCamera = getCamera();

        //camera preview
        mSurfaceView = (SurfaceView) findViewById(R.id.surfaceView);
        mSurfaceHolder = mSurfaceView.getHolder();
        mSurfaceHolder.addCallback(this);
        // deprecated setting, but required on Android versions prior to 3.0
        mSurfaceHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);

        mCameraContainerWidth = mSurfaceView.getLayoutParams().width;

        findViewById(R.id.btnRecord).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                if (mIsRecording) {
                    stopRecording();
                } else {
                    // initialize video camera
                    if (prepareVideoRecorder()) {

                        // Camera is available and unlocked, MediaRecorder is prepared,
                        // now you can start recording
                        mRecorder.start();

                        // inform the user that recording has started
                        Toast.makeText(getApplicationContext(), "Started recording", Toast.LENGTH_SHORT).show();
                        mIsRecording = true;
                    } else {
                        // prepare didn't work, release the camera
                        releaseMediaRecorder();
                        // inform user
                    }
                }
            }
        });
    }

    private void stopRecording() {
        mRecorder.stop();  // stop the recording
        releaseMediaRecorder(); // release the MediaRecorder object
        mCamera.lock();         // take camera access back from MediaRecorder

        // inform the user that recording has stopped
        Toast.makeText(this, "Recording complete", Toast.LENGTH_SHORT).show();
        mIsRecording = false;
    }

    @Override
    protected void onDestroy() {
        super.onDestroy();
        releaseMediaRecorder();       // if you are using MediaRecorder, release it first
        releaseCamera();              // release the camera immediately on pause event
    }

    private Camera getCamera() {

        Camera.CameraInfo cameraInfo = new Camera.CameraInfo();
        for (int camIdx = 0; camIdx < Camera.getNumberOfCameras(); camIdx++) {
            Camera.getCameraInfo(camIdx, cameraInfo);
            if (cameraInfo.facing == Camera.CameraInfo.CAMERA_FACING_FRONT) {
                try {
                    return mCamera = Camera.open(camIdx);
                } catch (RuntimeException e) {
                    Log.e("cameras", "Camera failed to open: " + e.getLocalizedMessage());
                }
            }
        }
        return null;
    }

    @Override
    protected void onPause() {
        super.onPause();
        releaseMediaRecorder();       // if you are using MediaRecorder, release it first
        releaseCamera();              // release the camera immediately on pause event
    }

    private Camera.Size getBestPreviewSize(Camera.Parameters parameters) {
        Camera.Size result=null;

        for (Camera.Size size : parameters.getSupportedPreviewSizes()) {
            if(size.width < size.height) continue; //we are only interested in landscape variants

            if (result == null) {
                result = size;
            }
            else {
                int resultArea = result.width*result.height;
                int newArea = size.width*size.height;

                if (newArea > resultArea) {
                    result = size;
                }
            }
        }

        return(result);
    }

    private boolean prepareVideoRecorder(){
        mRecorder = new MediaRecorder();

        // Step 1: Unlock and set camera to MediaRecorder
        mCamera.unlock();
        mRecorder.setCamera(mCamera);

        // Step 2: Set sources
        mRecorder.setAudioSource(MediaRecorder.AudioSource.DEFAULT);
        mRecorder.setVideoSource(MediaRecorder.VideoSource.DEFAULT);
        //recorder.setOutputFormat(MediaRecorder.OutputFormat.THREE_GPP);

        // Step 3: Set a CamcorderProfile (requires API Level 8 or higher)
        // Customise your profile based on a pre-existing profile
        CamcorderProfile profile = CamcorderProfile.get(Camera.CameraInfo.CAMERA_FACING_FRONT, CamcorderProfile.QUALITY_LOW);
        mRecorder.setProfile(profile);

        // Step 4: Set output file
        mRecorder.setOutputFile(new File(getFilesDir(), "movie-" + UUID.randomUUID().toString()).getAbsolutePath());
        //recorder.setMaxDuration(50000); // 50 seconds
        //recorder.setMaxFileSize(500000000); // Approximately 500 megabytes

        mRecorder.setVideoSize(mPreviewWidth, mPreviewHeight);

        // Step 5: Set the preview output
        mRecorder.setPreviewDisplay(mSurfaceHolder.getSurface());

        // Step 6: Prepare configured MediaRecorder
        try {
            mRecorder.prepare();
        } catch (IllegalStateException e) {
            Toast.makeText(getApplicationContext(), "exception: " + e.getMessage(), Toast.LENGTH_LONG).show();
            releaseMediaRecorder();
            return false;
        } catch (IOException e) {
            Toast.makeText(getApplicationContext(), "exception: " + e.getMessage(), Toast.LENGTH_LONG).show();
            releaseMediaRecorder();
            return false;
        }
        return true;
    }

    private void releaseMediaRecorder(){
        if (mRecorder != null) {
            mRecorder.reset();   // clear recorder configuration
            mRecorder.release(); // release the recorder object
            mRecorder = null;
            mCamera.lock();           // lock camera for later use
        }
    }

    private void releaseCamera(){
        if (mCamera != null){
            mCamera.release();        // release the camera for other applications
            mCamera = null;
        }
    }

    @Override
    public void surfaceCreated(SurfaceHolder holder) {
        // The Surface has been created, now tell the camera where to draw the preview.
            Camera.Parameters parameters = mCamera.getParameters();
            parameters.setRecordingHint(true);
            Camera.Size size = getBestPreviewSize(parameters);
        mCamera.setParameters(parameters);

            //resize the view to the specified surface view width in layout
            int newHeight = size.height / (size.width / mCameraContainerWidth);
            mSurfaceView.getLayoutParams().height = newHeight;
    }

    @Override
    public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {
        mPreviewHeight = mCamera.getParameters().getPreviewSize().height;
        mPreviewWidth = mCamera.getParameters().getPreviewSize().width;

        mCamera.stopPreview();
        try {
            mCamera.setPreviewDisplay(mSurfaceHolder);
        } catch (IOException e) {
            e.printStackTrace();
        }
        mCamera.startPreview();
    }

    @Override
    public void surfaceDestroyed(SurfaceHolder holder) {
        if (mIsRecording) {
            stopRecording();
        }

        releaseMediaRecorder();
        releaseCamera();
    }
}

Convert Xml to Table SQL Server

The sp_xml_preparedocument stored procedure will parse the XML and the OPENXML rowset provider will show you a relational view of the XML data.

For details and more examples check the OPENXML documentation.

As for your question,

DECLARE @XML XML
SET @XML = '<rows><row>
    <IdInvernadero>8</IdInvernadero>
    <IdProducto>3</IdProducto>
    <IdCaracteristica1>8</IdCaracteristica1>
    <IdCaracteristica2>8</IdCaracteristica2>
    <Cantidad>25</Cantidad>
    <Folio>4568457</Folio>
</row>
<row>
    <IdInvernadero>3</IdInvernadero>
    <IdProducto>3</IdProducto>
    <IdCaracteristica1>1</IdCaracteristica1>
    <IdCaracteristica2>2</IdCaracteristica2>
    <Cantidad>72</Cantidad>
    <Folio>4568457</Folio>
</row></rows>'

DECLARE @handle INT  
DECLARE @PrepareXmlStatus INT  

EXEC @PrepareXmlStatus= sp_xml_preparedocument @handle OUTPUT, @XML  

SELECT  *
FROM    OPENXML(@handle, '/rows/row', 2)  
    WITH (
    IdInvernadero INT,
    IdProducto INT,
    IdCaracteristica1 INT,
    IdCaracteristica2 INT,
    Cantidad INT,
    Folio INT
    )  


EXEC sp_xml_removedocument @handle 

sort csv by column

The reader acts like a generator. On a file with some fake data:

>>> import sys, csv
>>> data = csv.reader(open('data.csv'),delimiter=';')
>>> data
<_csv.reader object at 0x1004a11a0>
>>> data.next()
['a', ' b', ' c']
>>> data.next()
['x', ' y', ' z']
>>> data.next()
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
StopIteration

Using operator.itemgetter as Ignacio suggests:

>>> data = csv.reader(open('data.csv'),delimiter=';')
>>> import operator
>>> sortedlist = sorted(data, key=operator.itemgetter(2), reverse=True)
>>> sortedlist
[['x', ' y', ' z'], ['a', ' b', ' c']]

How do I convert a number to a numeric, comma-separated formatted string?

For SQL Server 2012, or later, an easier solution is to use FORMAT ()Documentation.
EG:

SELECT Format(1234567.8, '##,##0') 

Results in: 1,234,568

How to hide the keyboard when I press return key in a UITextField?

Swift 4

Set delegate of UITextField in view controller, field.delegate = self, and then:

extension ViewController: UITextFieldDelegate {
    func textFieldShouldReturn(_ textField: UITextField) -> Bool {
        // don't force `endEditing` if you want to be asked for resigning
        // also return real flow value, not strict, like: true / false
        return textField.endEditing(false)
    }
}

How to restart remote MySQL server running on Ubuntu linux?

sudo service mysql stop;
sudo service mysql start;

If the above process will not work let's check one the given code above you can stop Mysql server and again start server

ValueError: invalid literal for int () with base 10

Just for the record:

>>> int('55063.000000')
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
ValueError: invalid literal for int() with base 10: '55063.000000'

Got me here...

>>> int(float('55063.000000'))
55063.0

Has to be used!

Call a VBA Function into a Sub Procedure

Procedures in a Module start being useful and generic when you pass in arguments.

For example:

Public Function DoSomethingElse(strMessage As String)  
    MsgBox strMessage
End Function

Can now display any message that is passed in with the string variable called strMessage.

How to obtain the chat_id of a private Telegram channel?

You Can Too Do This:

Step 1)Convert Your Private Channel To Public Channel

Step 2)Set The ChannelName For This Channel

Step 3)then you Can change this Channel to Private

Step 4)Now Sending Your Message Using @ChannelName That you Set In Step 3

note:For Step 1 You Can Change One of Your Public Channel To Private For a short time.

Crystal Reports 13 And Asp.Net 3.5

I had faced the same issue because of some dll files were missing from References of VS13. I went to the location http://scn.sap.com/docs/DOC-7824 and installed the newest pack. It resolved the issue.

Can I hide the HTML5 number input’s spin box?

This CSS effectively hides the spin-button for webkit browsers (have tested it in Chrome 7.0.517.44 and Safari Version 5.0.2 (6533.18.5)):

_x000D_
_x000D_
input::-webkit-outer-spin-button,_x000D_
input::-webkit-inner-spin-button {_x000D_
    /* display: none; <- Crashes Chrome on hover */_x000D_
    -webkit-appearance: none;_x000D_
    margin: 0; /* <-- Apparently some margin are still there even though it's hidden */_x000D_
}_x000D_
_x000D_
input[type=number] {_x000D_
    -moz-appearance:textfield; /* Firefox */_x000D_
}
_x000D_
<input type="number" step="0.01" />
_x000D_
_x000D_
_x000D_

You can always use the inspector (webkit, possibly Firebug for Firefox) to look for matched CSS properties for the elements you are interested in, look for Pseudo elements. This image shows results for an input element type="number":

Inspector for input type=number (Chrome)

Difference between two lists

List<ObjectC> _list_DF_BW_ANB = new List<ObjectC>();    
List<ObjectA> _listA = new List<ObjectA>();
List<ObjectB> _listB = new List<ObjectB>();

foreach (var itemB in _listB )
{     
    var flat = 0;
    foreach(var itemA in _listA )
    {
        if(itemA.ProductId==itemB.ProductId)
        {
            flat = 1;
            break;
        }
    }
    if (flat == 0)
    {
        _list_DF_BW_ANB.Add(itemB);
    }
}

Java SecurityException: signer information does not match

In my case, I had duplicated JAR version of BouncyCastle in my library path :S

Sort Dictionary by keys

Swift 5

Input your dictionary that you want to sort alphabetically by keys.

// Sort inputted dictionary with keys alphabetically.
func sortWithKeys(_ dict: [String: Any]) -> [String: Any] {
    let sorted = dict.sorted(by: { $0.key < $1.key })
    var newDict: [String: Any] = [:]
    for sortedDict in sorted {
        newDict[sortedDict.key] = sortedDict.value
    }
    return newDict
}

dict.sorted(by: { $0.key < $1.key }) by it self returns a tuple (value, value) instead of a dictionary [value: value]. Thus, the for loop parses the tuple to return as a dictionary. That way, you put in a dictionary & get a dictionary back.

What is the difference between single and double quotes in SQL?

In ANSI SQL, double quotes quote object names (e.g. tables) which allows them to contain characters not otherwise permitted, or be the same as reserved words (Avoid this, really).

Single quotes are for strings.

However, MySQL is oblivious to the standard (unless its SQL_MODE is changed) and allows them to be used interchangably for strings.

Moreover, Sybase and Microsoft also use square brackets for identifier quoting.

So it's a bit vendor specific.

Other databases such as Postgres and IBM actually adhere to the ansi standard :)

Angularjs: input[text] ngChange fires while the value is changing

I had exactly the same problem and this worked for me. Add ng-model-update and ng-keyup and you're good to go! Here is the docs

 <input type="text" name="userName"
         ng-model="user.name"
         ng-change="update()"
         ng-model-options="{ updateOn: 'blur' }"
         ng-keyup="cancel($event)" />

What is the Simplest Way to Reverse an ArrayList?

A little more readable :)

public static <T> ArrayList<T> reverse(ArrayList<T> list) {
    int length = list.size();
    ArrayList<T> result = new ArrayList<T>(length);

    for (int i = length - 1; i >= 0; i--) {
        result.add(list.get(i));
    }

    return result;
}

Copy file(s) from one project to another using post build event...VS2010

xcopy "$(TargetDir)*$(TargetExt)" "$(SolutionDir)\Scripts\MigrationScripts\Library\" /F /R /Y /I

/F – Displays full source & target file names

/R – This will overwrite read-only files

/Y – Suppresses prompting to overwrite an existing file(s)

/I – Assumes that destination is directory (but must ends with )

A little trick – in target you must end with character \ to tell xcopy that target is directory and not file!

Use jQuery to change a second select list based on the first select list option

_x000D_
_x000D_
$("#select1").change(function() {_x000D_
  if ($(this).data('options') === undefined) {_x000D_
    /*Taking an array of all options-2 and kind of embedding it on the select1*/_x000D_
    $(this).data('options', $('#select2 option').clone());_x000D_
  }_x000D_
  var id = $(this).val();_x000D_
  var options = $(this).data('options').filter('[value=' + id + ']');_x000D_
  $('#select2').html(options);_x000D_
});
_x000D_
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.0.0/jquery.min.js"></script>_x000D_
<select name="select1" id="select1">_x000D_
  <option value="1">Fruit</option>_x000D_
  <option value="2">Animal</option>_x000D_
  <option value="3">Bird</option>_x000D_
  <option value="4">Car</option>_x000D_
</select>_x000D_
_x000D_
_x000D_
<select name="select2" id="select2">_x000D_
  <option value="1">Banana</option>_x000D_
  <option value="1">Apple</option>_x000D_
  <option value="1">Orange</option>_x000D_
  <option value="2">Wolf</option>_x000D_
  <option value="2">Fox</option>_x000D_
  <option value="2">Bear</option>_x000D_
  <option value="3">Eagle</option>_x000D_
  <option value="3">Hawk</option>_x000D_
  <option value="4">BWM<option>_x000D_
</select>
_x000D_
_x000D_
_x000D_

Using jQuery data() to store data

I guess hiding elements doesn't work cross-browser(2012), I have'nt tested it myself.

How to run multiple DOS commands in parallel?

if you have multiple parameters use the syntax as below. I have a bat file with script as below:

start "dummyTitle" [/options] D:\path\ProgramName.exe Param1 Param2 Param3 
start "dummyTitle" [/options] D:\path\ProgramName.exe Param4 Param5 Param6 

This will open multiple consoles.

Why do people say that Ruby is slow?

Writing code is slow. Reading code is slow. Finding and fixing bugs is slow. Adding features and enhancements is slow. Anything that improves on the previous is a win. Very rarely is execution performance an issue.

jQuery on window resize

Give your anonymous function a name, then:

$(window).on("resize", doResize);

http://api.jquery.com/category/events/

Pad a string with leading zeros so it's 3 characters long in SQL Server 2008

For integers you can use implicit conversion from int to varchar:

SELECT RIGHT(1000 + field, 3)

Using Pipes within ngModel on INPUT Elements in Angular

My Solution is given below here searchDetail is an object..

<p-calendar  [ngModel]="searchDetail.queryDate | date:'MM/dd/yyyy'"  (ngModelChange)="searchDetail.queryDate=$event" [showIcon]="true" required name="queryDate" placeholder="Enter the Query Date"></p-calendar>

<input id="float-input" type="text" size="30" pInputText [ngModel]="searchDetail.systems | json"  (ngModelChange)="searchDetail.systems=$event" required='true' name="systems"
            placeholder="Enter the Systems">

JQUERY ajax passing value from MVC View to Controller

Here's an alternative way to do the same call. And your type should always be in CAPS, eg. type:"GET" / type:"POST".

$.ajax({
      url:/ControllerName/ActionName,
      data: "id=" + Id + "&param2=" + param2,
      type: "GET",
      success: function(data){
            // code here
      },
      error: function(passParams){
           // code here
      }
});

Another alternative will be to use the data-ajax on a link.

<a href="/ControllerName/ActionName/" data-ajax="true" data-ajax-method="GET" data-ajax-mode="replace" data-ajax-update="#_content">Click Me!</a>

Assuming u had a div with the I'd _content, this will call the action and replace the content inside that div with the data returned from that action.

<div id="_content"></div>

Not really a direct answer to ur question but its some info u should be aware of ;).

Print the contents of a DIV

The best way to do it would be to submit the contents of the div to the server and open a new window where the server could put those contents into the new window.

If that's not an option you can try to use a client-side language like javascript to hide everything on the page except that div and then print the page...

How do I find a default constraint using INFORMATION_SCHEMA?

Probably because on some of the other SQL DBMSs the "default constraint" is not really a constraint, you'll not find its name in "INFORMATION_SCHEMA.TABLE_CONSTRAINTS", so your best bet is "INFORMATION_SCHEMA.COLUMNS" as others have mentioned already.

(SQLServer-ignoramus here)

The only a reason I can think of when you have to know the "default constraint"'s name is if SQLServer doesn't support "ALTER TABLE xxx ALTER COLUMN yyy SET DEFAULT..." command. But then you are already in a non-standard zone and you have to use the product-specific ways to get what you need.

How to resume Fragment from BackStack if exists

getFragmentManager().addOnBackStackChangedListener(new FragmentManager.OnBackStackChangedListener() {

    @Override
    public void onBackStackChanged() {

        if(getFragmentManager().getBackStackEntryCount()==0) {
            onResume();
        }    
    }
});

How do I use the Simple HTTP client in Android?

You can use like this:

public static String executeHttpPost1(String url,
            HashMap<String, String> postParameters) throws UnsupportedEncodingException {
        // TODO Auto-generated method stub

        HttpClient client = getNewHttpClient();

        try{
        request = new HttpPost(url);

        }
        catch(Exception e){
            e.printStackTrace();
        }


        if(postParameters!=null && postParameters.isEmpty()==false){

            List<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>(postParameters.size());
            String k, v;
            Iterator<String> itKeys = postParameters.keySet().iterator();
            while (itKeys.hasNext()) 
            {
                k = itKeys.next();
                v = postParameters.get(k);
                nameValuePairs.add(new BasicNameValuePair(k, v));
            }     

            UrlEncodedFormEntity urlEntity  = new  UrlEncodedFormEntity(nameValuePairs);
            request.setEntity(urlEntity);

        }
        try {


            Response = client.execute(request,localContext);
            HttpEntity entity = Response.getEntity();
            int statusCode = Response.getStatusLine().getStatusCode();
            Log.i(TAG, ""+statusCode);


            Log.i(TAG, "------------------------------------------------");





                try{
                    InputStream in = (InputStream) entity.getContent(); 
                    //Header contentEncoding = Response.getFirstHeader("Content-Encoding");
                    /*if (contentEncoding != null && contentEncoding.getValue().equalsIgnoreCase("gzip")) {
                        in = new GZIPInputStream(in);
                    }*/
                    BufferedReader reader = new BufferedReader(new InputStreamReader(in));
                    StringBuilder str = new StringBuilder();
                    String line = null;
                    while((line = reader.readLine()) != null){
                        str.append(line + "\n");
                    }
                    in.close();
                    response = str.toString();
                    Log.i(TAG, "response"+response);
                }
                catch(IllegalStateException exc){

                    exc.printStackTrace();
                }


        } catch(Exception e){

            Log.e("log_tag", "Error in http connection "+response);         

        }
        finally {

        }

        return response;
    }

How to set up java logging using a properties file? (java.util.logging)

I have tried your code in above code don't use [preferences.load(configFile);] statement and it will work.here is running sample code

public static void main(String[]s)
{

    Logger log = Logger.getLogger("MyClass");
    try {
    FileInputStream fis =  new FileInputStream("p.properties");
    LogManager.getLogManager().readConfiguration(fis);
    log.setLevel(Level.FINE);
    log.addHandler(new java.util.logging.ConsoleHandler());
    log.setUseParentHandlers(false);

    log.info("starting myApp");
    fis.close();

    } 
    catch(IOException e) {
    e.printStackTrace();
    }
}

When should the xlsm or xlsb formats be used?

.xlsx loads 4 times longer than .xlsb and saves 2 times longer and has 1.5 times a bigger file. I tested this on a generated worksheet with 10'000 rows * 1'000 columns = 10'000'000 (10^7) cells of simple chained =…+1 formulas:

?--------------------------------?
¦              ¦ .xlsx  ¦ .xlsb  ¦
¦--------------+--------+--------¦
¦ loading time ¦ 165s   ¦  43s   ¦
+--------------+--------+--------¦
¦ saving time  ¦ 115s   ¦  61s   ¦
+--------------+--------+--------¦
¦ file size    ¦  91 MB ¦  65 MB ¦
?--------------------------------?

(Hardware: Core2Duo 2.3 GHz, 4 GB RAM, 5.400 rpm SATA II HD; Windows 7, under somewhat heavy load from other processes.)

Beside this, there should be no differences. More precisely,

both formats support exactly the same feature set

cites this blog post from 2006-08-29. So maybe the info that .xlsb does not support Ribbon code is newer than the upper citation, but I figure that forum source of yours is just wrong. When cracking open the binary file, it seems to condensedly mimic the OOXML file structure 1-to-1: Blog article from 2006-08-07

How to print all session variables currently set?

Not a simple way, no.

Let's say that by "active" you mean "hasn't passed the maximum lifetime" and hasn't been explicitly destroyed and that you're using the default session handler.

  • First, the maximum lifetime is defined as a php.ini config and is defined in terms of the last activity on the session. So the "expiry" mechanism would have to read the content of the sessions to determine the application-defined expiry.
  • Second, you'd have to manually read the sessions directory and read the files, whose format I don't even know they're in.

If you really need this, you must implement some sort of custom session handler. See session_set_save_handler.

Take also in consideration that you'll have no feedback if the user just closes the browser or moves away from your site without explciitly logging out. Depending on much inactivity you consider the threshold to deem a session "inactive", the number of false positives you'll get may be very high.

How do I move to end of line in Vim?

In many cases, when we are inside a string we are enclosed by a double quote, or while writing a statement we don't want to press escape and go to end of that line with arrow key and press the semicolon(;) just to end the line. Write the following line inside your vimrc file:

imap <C-l> <Esc>$a

What does the line say? It maps Ctrl+l to a series of commands. It is equivalent to you pressing Esc (command mode), $ (end of line), a (append) at once.

How do I include a file over 2 directories back?

I recomend to use __DIR__ to specify current php file directory. Check here for the reason.

__DIR__ . /../../index.php

How to correctly implement custom iterators and const_iterators?

  • Choose type of iterator which fits your container: input, output, forward etc.
  • Use base iterator classes from standard library. For example, std::iterator with random_access_iterator_tag.These base classes define all type definitions required by STL and do other work.
  • To avoid code duplication iterator class should be a template class and be parametrized by "value type", "pointer type", "reference type" or all of them (depends on implementation). For example:

    // iterator class is parametrized by pointer type
    template <typename PointerType> class MyIterator {
        // iterator class definition goes here
    };
    
    typedef MyIterator<int*> iterator_type;
    typedef MyIterator<const int*> const_iterator_type;
    

    Notice iterator_type and const_iterator_type type definitions: they are types for your non-const and const iterators.

See Also: standard library reference

EDIT: std::iterator is deprecated since C++17. See a relating discussion here.

Remove trailing newline from the elements of a string list

This can be done using list comprehensions as defined in PEP 202

[w.strip() for w in  ['this\n', 'is\n', 'a\n', 'list\n', 'of\n', 'words\n']]

What's the fastest way to do a bulk insert into Postgres?

There is an alternative to using COPY, which is the multirow values syntax that Postgres supports. From the documentation:

INSERT INTO films (code, title, did, date_prod, kind) VALUES
    ('B6717', 'Tampopo', 110, '1985-02-10', 'Comedy'),
    ('HG120', 'The Dinner Game', 140, DEFAULT, 'Comedy');

The above code inserts two rows, but you can extend it arbitrarily, until you hit the maximum number of prepared statement tokens (it might be $999, but I'm not 100% sure about that). Sometimes one cannot use COPY, and this is a worthy replacement for those situations.

How do I access ViewBag from JS

<script type="text/javascript">
      $(document).ready(function() {
                showWarning('@ViewBag.Message');
      });

</script>

You can use ViewBag.PropertyName in javascript like this.

Checking for empty or null List<string>

You can use Count property of List in c#

please find below code which checks list empty and null both in a single condition

if(myList == null || myList.Count == 0)
{
    //Do Something 
}

How can I debug a .BAT script?

Or.... Call your main .bat file from another .bat file and output the result to a result file i.e.

runner.bat > mainresults.txt

Where runner.bat calls the main .bat file

You should see all the actions performed in the main .bat file now

Check if a property exists in a class

Your method looks like this:

public static bool HasProperty(this object obj, string propertyName)
{
    return obj.GetType().GetProperty(propertyName) != null;
}

This adds an extension onto object - the base class of everything. When you call this extension you're passing it a Type:

var res = typeof(MyClass).HasProperty("Label");

Your method expects an instance of a class, not a Type. Otherwise you're essentially doing

typeof(MyClass) - this gives an instanceof `System.Type`. 

Then

type.GetType() - this gives `System.Type`
Getproperty('xxx') - whatever you provide as xxx is unlikely to be on `System.Type`

As @PeterRitchie correctly points out, at this point your code is looking for property Label on System.Type. That property does not exist.

The solution is either

a) Provide an instance of MyClass to the extension:

var myInstance = new MyClass()
myInstance.HasProperty("Label")

b) Put the extension on System.Type

public static bool HasProperty(this Type obj, string propertyName)
{
    return obj.GetProperty(propertyName) != null;
}

and

typeof(MyClass).HasProperty("Label");

Changing tab bar item image and text color iOS

For Swift 4.0, it's now changed as:

tabBarItem.setTitleTextAttributes([NSAttributedStringKey.foregroundColor: UIColor.gray], for: .normal)
tabBarItem.setTitleTextAttributes([NSAttributedStringKey.foregroundColor: UIColor.blue], for: .selected)

You don't have to subclass the UITabBarItem if your requirement is only to change the text color. Just put the above code inside your view controller's viewDidLoad function.

For global settings change tabBarItem to UITabBarItem.appearance().

how to set value of a input hidden field through javascript?

Your code for setting value for hidden input is correct. Here is the example. Maybe you have some conditions in your if statements that are not allowing your scripts to execute.

'negative' pattern matching in python

Use a negative match. (Also note that whitespace is significant, by default, inside a regex so don't space things out. Alternatively, use re.VERBOSE.)

for item in output:
    matchObj = re.search("^(OK|\\.)", item)
    if not matchObj:
        print "got item " + item

How to Sort Date in descending order From Arraylist Date in android?

Date's compareTo() you're using will work for ascending order.

To do descending, just reverse the value of compareTo() coming out. You can use a single Comparator class that takes in a flag/enum in the constructor that identifies the sort order

public int compare(MyObject lhs, MyObject rhs) {

    if(SortDirection.Ascending == m_sortDirection) {
        return lhs.MyDateTime.compareTo(rhs.MyDateTime);
    }

    return rhs.MyDateTime.compareTo(lhs.MyDateTime);
}

You need to call Collections.sort() to actually sort the list.

As a side note, I'm not sure why you're defining your map inside your for loop. I'm not exactly sure what your code is trying to do, but I assume you want to populate the indexed values from your for loop in to the map.