SyntaxFix

Programs & Examples On #Motorola

Motorola is an American multinational telecommunications company which designs and sells wireless network infrastructure equipment.

Android Push Notifications: Icon not displaying in notification, white square shown instead

Requirements to fix this issue:

  1. Image Format: 32-bit PNG (with alpha)

  2. Image should be Transparent

  3. Transparency Color Index: White (FFFFFF)

Source: http://gr1350.blogspot.com/2017/01/problem-with-setsmallicon.html

How to mount the android img file under linux?

See the answer at: http://omappedia.org/wiki/Android_eMMC_Booting#Modifying_.IMG_Files

First you need to "uncompress" userdata.img with simg2img, then you can mount it via the loop device.

ADB error: cannot connect to daemon

Delete you AVD and create another. Maybe isn't the perfect thing to do, but it's the fastest.

How do detect Android Tablets in general. Useragent?

Here is what I use:

public static boolean onTablet()
    {
    int intScreenSize = getResources().getConfiguration().screenLayout & Configuration.SCREENLAYOUT_SIZE_MASK;

    return (intScreenSize == Configuration.SCREENLAYOUT_SIZE_LARGE) // LARGE
    || (intScreenSize == Configuration.SCREENLAYOUT_SIZE_LARGE + 1); // Configuration.SCREENLAYOUT_SIZE_XLARGE
    }

Making the Android emulator run faster

I recently switched from a core 2 @ 2.5 with 3gb of ram to an i7 @ 1.73 with 8gb ram (both systems ran Ubuntu 10.10) and the emulator runs at least twice as fast now. Throwing more hardware at it certainly does help.

How can I connect to Android with ADB over TCP?

I do not know how to connect the device without any USB connection at all, but if you manage to connect it maybe at another computer you can switch the adbd to TCP mode by issuing 

adb tcpip <port>

from a terminal and connect to your device over wifi from any PC on the network by:

adb connect <ip>:<port>

Maybe it is also possible to switch to TCP mode from a terminal on the device.

HTML5 <video> element on Android

If you manually call video.play() it should work:

<!DOCTYPE html>
<html>
<head>
  <script>
    function init() {
      enableVideoClicks();
    }

    function enableVideoClicks() {
      var videos = document.getElementsByTagName('video') || [];
      for (var i = 0; i < videos.length; i++) {
        // TODO: use attachEvent in IE
        videos[i].addEventListener('click', function(videoNode) {
          return function() {
            videoNode.play();
          };
        }(videos[i]));
      }
    }
  </script>
</head>
<body onload="init()">

  <video src="sample.mp4" width="400" height="300" controls></video>

  ...

</body>
</html>

Python: "Indentation Error: unindent does not match any outer indentation level"

Sorry I can't add comments as my reputation is not high enough :-/, so this will have to be an answer.

As several have commented, the code you have posted contains several (5) syntax errors (twice = instead of == and three ':' missing).

Once the syntax errors corrected I do not have any issue, be it indentation or else; of course it's impossible to see if you have mixed tabs and spaces as somebody else has suggested, which is likely your problem.

But the real point I wanted to underline is that: tabnanny IS NOT REALIABLE: you might be getting an 'indentation' error when it's actually just a syntax error.

Eg. I got it when I had added one closed parenthesis more than necessary ;-)

i += [func(a, b, [c] if True else None))]

would provoke a warning from tabnanny for the next line.

Hope this helps!

How to "test" NoneType in python?

Not sure if this answers the question. But I know this took me a while to figure out. I was looping through a website and all of sudden the name of the authors weren't there anymore. So needed a check statement. 

if type(author) == type(None):
     my if body
else:
    my else body

Author can be any variable in this case, and None can be any type that you are checking for.

std::string to char*

To be strictly pedantic, you cannot "convert a std::string into a char* or char[] data type."

As the other answers have shown, you can copy the content of the std::string to a char array, or make a const char* to the content of the std::string so that you can access it in a "C style".

If you're trying to change the content of the std::string, the std::string type has all of the methods to do anything you could possibly need to do to it.

If you're trying to pass it to some function which takes a char*, there's std::string::c_str().

ADB not recognising Nexus 4 under Windows 7

It was a driver missing problem with me. I had enabled the USB debugging, tried changing the USB cable, tried reinstalling the Google USB drivers, but nothing came to my rescue.

Then ultimately I downloaded the device drivers as suggested here.

To make sure whether you have a device driver problem, go to:

  1. Computer->right click
  2. Manage
  3. Device Manager

And see if you have your Nexus shown as an "Android device" or as a device in "Others".

If it shows in "Others", your problem should be resolved by downloading & extracting this and then following these steps:

  1. Right click on your device after finding it in Device Manager as per the above mentioned three steps.
  2. Say Update driver software.
  3. Say Browse My computer for driver software
  4. Pinpoint it to the location where you had downloaded the drivers from the above link.

Finally, your device will show up as follows:

Computer Management Screenshot

As soon as you do this, a popup will show up on your device asking for permission to debug. Once you accept, you are ready!

Convert String to equivalent Enum value

Assuming you use Java 5 enums (which is not so certain since you mention old Enumeration class), you can use the valueOf method of java.lang.Enum subclass:

MyEnum e = MyEnum.valueOf("ONE_OF_CONSTANTS");

How to know which version of Symfony I have?

From inside your Symfony project, you can get the value in PHP this way:

$symfony_version = \Symfony\Component\HttpKernel\Kernel::VERSION;

Reading PDF content with itextsharp dll in VB.NET or C#

 
using iTextSharp.text.pdf;
using iTextSharp.text.pdf.parser;
using System.IO;

public string ReadPdfFile(string fileName)
{
    StringBuilder text = new StringBuilder();

    if (File.Exists(fileName))
    {
        PdfReader pdfReader = new PdfReader(fileName);

        for (int page = 1; page <= pdfReader.NumberOfPages; page++)
        {
            ITextExtractionStrategy strategy = new SimpleTextExtractionStrategy();
            string currentText = PdfTextExtractor.GetTextFromPage(pdfReader, page, strategy);

            currentText = Encoding.UTF8.GetString(ASCIIEncoding.Convert(Encoding.Default, Encoding.UTF8, Encoding.Default.GetBytes(currentText)));
            text.Append(currentText);
        }
        pdfReader.Close();
    }
    return text.ToString();
}

HTML Button Close Window

JavaScript can only close a window that was opened using JavaScript. Example below:

<script>
function myFunction() {
  var str = "Sample";
  var result = str.link("https://sample.com");
  document.getElementById("demo").innerHTML = result;
}
</script>

Iterate through a C++ Vector using a 'for' loop

 
 //different declaration type
    vector<int>v;  
    vector<int>v2(5,30); //size is 5 and fill up with 30
    vector<int>v3={10,20,30};
    
    //From C++11 and onwards
    for(auto itr:v2)
        cout<<"\n"<<itr;
     
     //(pre c++11)   
    for(auto itr=v3.begin(); itr !=v3.end(); itr++)
        cout<<"\n"<<*itr;

Populating a database in a Laravel migration file

This should do what you want.

public function up()
{
    DB::table('user')->insert(array('username'=>'dude', 'password'=>'z19pers!'));
}

What is the SQL command to return the field names of a table?

MySQL 3 and 4 (and 5):

desc tablename

which is an alias for

show fields from tablename

SQL Server (from 2000) and MySQL 5:

select COLUMN_NAME from INFORMATION_SCHEMA.COLUMNS 
where TABLE_NAME = 'tablename'

Completing the answer: like people below have said, in SQL Server you can also use the stored procedure sp_help

exec sp_help 'tablename'

How to check if all of the following items are in a list?

I like these two because they seem the most logical, the latter being shorter and probably fastest (shown here using set literal syntax which has been backported to Python 2.7):

all(x in {'a', 'b', 'c'} for x in ['a', 'b'])
#   or
{'a', 'b'}.issubset({'a', 'b', 'c'})

What is the easiest way to get the current day of the week in Android?

 
public String weekdays[] = new      DateFormatSymbols(Locale.ITALIAN).getWeekdays();
 Calendar c = Calendar.getInstance();
 Date date = new Date();
 c.setTime(date);
 int dayOfWeek = c.get(Calendar.DAY_OF_WEEK);
 System.out.println(dayOfWeek);
 System.out.println(weekdays[dayOfWeek]);

How to make all controls resize accordingly proportionally when window is maximized?

In WPF there are certain 'container' controls that automatically resize their contents and there are some that don't.

Here are some that do not resize their contents (I'm guessing that you are using one or more of these):

StackPanel
WrapPanel
Canvas
TabControl

Here are some that do resize their contents:

Grid
UniformGrid
DockPanel

Therefore, it is almost always preferable to use a Grid instead of a StackPanel unless you do not want automatic resizing to occur. Please note that it is still possible for a Grid to not size its inner controls... it all depends on your Grid.RowDefinition and Grid.ColumnDefinition settings:

<Grid>
    <Grid.RowDefinitions>
        <RowDefinition Height="100" /> <!--<<< Exact Height... won't resize -->
        <RowDefinition Height="Auto" /> <!--<<< Will resize to the size of contents -->
        <RowDefinition Height="*" /> <!--<<< Will resize taking all remaining space -->
    </Grid.RowDefinitions>
</Grid>

You can find out more about the Grid control from the Grid Class page on MSDN. You can also find out more about these container controls from the WPF Container Controls Overview page on MSDN.

Further resizing can be achieved using the FrameworkElement.HorizontalAlignment and FrameworkElement.VerticalAlignment properties. The default value of these properties is Stretch which will stretch elements to fit the size of their containing controls. However, when they are set to any other value, the elements will not stretch.

UPDATE >>>

In response to the questions in your comment:

Use the Grid.RowDefinition and Grid.ColumnDefinition settings to organise a basic structure first... it is common to add Grid controls into the cells of outer Grid controls if need be. You can also use the Grid.ColumnSpan and Grid.RowSpan properties to enable controls to span multiple columns and/or rows of a Grid.

It is most common to have at least one row/column with a Height/Width of "*" which will fill all remaining space, but you can have two or more with this setting, in which case the remaining space will be split between the two (or more) rows/columns. 'Auto' is a good setting to use for the rows/columns that are not set to '"*"', but it really depends on how you want the layout to be.

There is no Auto setting that you can use on the controls in the cells, but this is just as well, because we want the Grid to size the controls for us... therefore, we don't want to set the Height or Width of these controls at all.

The point that I made about the FrameworkElement.HorizontalAlignment and FrameworkElement.VerticalAlignment properties was just to let you know of their existence... as their default value is already Stretch, you don't generally need to set them explicitly.

The Margin property is generally just used to space your controls out evenly... if you drag and drop controls from the Visual Studio Toolbox, VS will set the Margin property to place your control exactly where you dropped it but generally, this is not what we want as it will mess with the auto sizing of controls. If you do this, then just delete or edit the Margin property to suit your needs.

Regex for Mobile Number Validation

Try this regex:

^(\+?\d{1,4}[\s-])?(?!0+\s+,?$)\d{10}\s*,?$

Explanation of the regex using Perl's YAPE is as below:

NODE                     EXPLANATION
----------------------------------------------------------------------
(?-imsx:                 group, but do not capture (case-sensitive)
                         (with ^ and $ matching normally) (with . not
                         matching \n) (matching whitespace and #
                         normally):
----------------------------------------------------------------------
  ^                        the beginning of the string
----------------------------------------------------------------------
  (                        group and capture to \1 (optional
                           (matching the most amount possible)):
----------------------------------------------------------------------
    \+?                      '+' (optional (matching the most amount
                             possible))
----------------------------------------------------------------------
    \d{1,4}                  digits (0-9) (between 1 and 4 times
                             (matching the most amount possible))
----------------------------------------------------------------------
    [\s-]                    any character of: whitespace (\n, \r,
                             \t, \f, and " "), '-'
----------------------------------------------------------------------
  )?                       end of \1 (NOTE: because you are using a
                           quantifier on this capture, only the LAST
                           repetition of the captured pattern will be
                           stored in \1)
----------------------------------------------------------------------
  (?!                      look ahead to see if there is not:
----------------------------------------------------------------------
    0+                       '0' (1 or more times (matching the most
                             amount possible))
----------------------------------------------------------------------
    \s+                      whitespace (\n, \r, \t, \f, and " ") (1
                             or more times (matching the most amount
                             possible))
----------------------------------------------------------------------
    ,?                       ',' (optional (matching the most amount
                             possible))
----------------------------------------------------------------------
    $                        before an optional \n, and the end of
                             the string
----------------------------------------------------------------------
  )                        end of look-ahead
----------------------------------------------------------------------
  \d{10}                   digits (0-9) (10 times)
----------------------------------------------------------------------
  \s*                      whitespace (\n, \r, \t, \f, and " ") (0 or
                           more times (matching the most amount
                           possible))
----------------------------------------------------------------------
  ,?                       ',' (optional (matching the most amount
                           possible))
----------------------------------------------------------------------
  $                        before an optional \n, and the end of the
                           string
----------------------------------------------------------------------
)                        end of grouping
----------------------------------------------------------------------

Choosing a jQuery datagrid plugin?

A good plugin that I have used before is DataTables.

Best way to store chat messages in a database?

You could create a database for x conversations which contains all messages of these conversations. This would allow you to add a new Database (or server) each time x exceeds. X is the number conversations your infrastructure supports (depending on your hardware,...).

The problem is still, that there may be big conversations (with a lot of messages) on the same database. e.g. you have database A and database B an each stores e.g. 1000 conversations. It my be possible that there are far more "big" conversations on server A than on server B (since this is user created content). You could add a "master" database that contains a lookup, on which database/server the single conversations can be found (or you have a schema to assign a database from hash/modulo or something).

Maybe you can find real world architectures that deal with the same problems (you may not be the first one), and that have already been solved.

Unable to connect with remote debugger

uninstall your application, then run react-native run-android. then click debugging end in chrome replace http://localhost:8081/debugger-ui/, end run react-native run-android. if you still haven't succeeded try again

Printing the value of a variable in SQL Developer

SQL Developer seems to only output the DBMS_OUTPUT text when you have explicitly turned on the DBMS_OUTPUT window pane.

Go to (Menu) VIEW -> Dbms_output to invoke the pane.

Click on the Green Plus sign to enable output for your connection and then run the code.

EDIT: Don't forget to set the buffer size according to the amount of output you are expecting.

What is 'PermSize' in Java?

This blog post gives a nice explanation and some background. Basically, the "permanent generation" (whose size is given by PermSize) is used to store things that the JVM has to allocate space for, but which will not (normally) be garbage-collected (hence "permanent") (+). That means for example loaded classes and static fields.

There is also a FAQ on garbage collection directly from Sun, which answers some questions about the permanent generation. Finally, here's a blog post with a lot of technical detail.

(+) Actually parts of the permanent generation will be GCed, e.g. class objects will be removed when a class is unloaded. But that was uncommon when the permanent generation was introduced into the JVM, hence the name.

Moving up one directory in Python

Use the os module:

import os
os.chdir('..')

should work

WPF global exception handler

A quick example of code for Application.Dispatcher.UnhandledException:

public App() {
    this.Dispatcher.UnhandledException += OnDispatcherUnhandledException;
}

void OnDispatcherUnhandledException(object sender, System.Windows.Threading.DispatcherUnhandledExceptionEventArgs e) {
    string errorMessage = string.Format("An unhandled exception occurred: {0}", e.Exception.Message);
    MessageBox.Show(errorMessage, "Error", MessageBoxButton.OK, MessageBoxImage.Error);
    // OR whatever you want like logging etc. MessageBox it's just example
    // for quick debugging etc.
    e.Handled = true;
}

I added this code in App.xaml.cs

pass post data with window.location.href

As it was said in other answers there is no way to make a POST request using window.location.href, to do it you can create a form and submit it immediately.

You can use this function:

function postForm(path, params, method) {
    method = method || 'post';

    var form = document.createElement('form');
    form.setAttribute('method', method);
    form.setAttribute('action', path);

    for (var key in params) {
        if (params.hasOwnProperty(key)) {
            var hiddenField = document.createElement('input');
            hiddenField.setAttribute('type', 'hidden');
            hiddenField.setAttribute('name', key);
            hiddenField.setAttribute('value', params[key]);

            form.appendChild(hiddenField);
        }
    }

    document.body.appendChild(form);
    form.submit();
}

postForm('mysite.com/form', {arg1: 'value1', arg2: 'value2'});

https://stackoverflow.com/a/133997/2965158

javascript change background color on click

You can use setTimeout():

_x000D_
_x000D_ 
var addBg = function(e) {_x000D_
  e = e || window.event;_x000D_
  e.preventDefault();_x000D_
  var el = e.target || e.srcElement;_x000D_
  el.className = 'bg';_x000D_
  setTimeout(function() {_x000D_
    removeBg(el);_x000D_
  }, 10 * 1000); //<-- (in miliseconds)_x000D_
};_x000D_
_x000D_
var removeBg = function(el) {_x000D_
  el.className = '';_x000D_
};
_x000D_ 
div {_x000D_
  border: 1px solid grey;_x000D_
  padding: 5px 7px;_x000D_
  display: inline-block;_x000D_
  margin: 5px;_x000D_
}_x000D_
.bg {_x000D_
  background: orange;_x000D_
}
_x000D_ 
<body onclick='addBg(event);'>This is body_x000D_
  <br/>_x000D_
  <div onclick='addBg(event);'>This is div_x000D_
  </div>_x000D_
</body>
_x000D_
_x000D_
_x000D_

Using jQuery:

_x000D_
_x000D_ 
var addBg = function(e) {_x000D_
  e.stopPropagation();_x000D_
  var el = $(this);_x000D_
  el.addClass('bg');_x000D_
  setTimeout(function() {_x000D_
    removeBg(el);_x000D_
  }, 10 * 1000); //<-- (in miliseconds)_x000D_
};_x000D_
_x000D_
var removeBg = function(el) {_x000D_
  $(el).removeClass('bg');_x000D_
};_x000D_
_x000D_
$(function() {_x000D_
  $('body, div').on('click', addBg);_x000D_
});
_x000D_ 
div {_x000D_
  border: 1px solid grey;_x000D_
  padding: 5px 7px;_x000D_
  display: inline-block;_x000D_
  margin: 5px;_x000D_
}_x000D_
.bg {_x000D_
  background: orange;_x000D_
}
_x000D_ 
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.9.1/jquery.min.js"></script>_x000D_
_x000D_
<body>This is body_x000D_
  <br/>_x000D_
  <div>This is div</div>_x000D_
</body>
_x000D_
_x000D_
_x000D_

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

This version need not math library and checked the return value of clock_gettime().

#include <time.h>
#include <stdlib.h>
#include <stdint.h>

/**
 * @return milliseconds
 */
uint64_t get_now_time() {
  struct timespec spec;
  if (clock_gettime(1, &spec) == -1) { /* 1 is CLOCK_MONOTONIC */
    abort();
  }

  return spec.tv_sec * 1000 + spec.tv_nsec / 1e6;
}

How to change border color of textarea on :focus

 
.input:focus {
    outline: none !important;
    border:1px solid red;
    box-shadow: 0 0 10px #719ECE;
}

Validation of file extension before uploading file

I came here because I was sure none of the answers here were quite...poetic:

_x000D_
_x000D_ 
function checkextension() {_x000D_
  var file = document.querySelector("#fUpload");_x000D_
  if ( /\.(jpe?g|png|gif)$/i.test(file.files[0].name) === false ) { alert("not an image!"); }_x000D_
}
_x000D_ 
<input type="file" id="fUpload" onchange="checkextension()"/>
_x000D_
_x000D_
_x000D_

Select query with date condition

The semicolon character is used to terminate the SQL statement.

You can either use # signs around a date value or use Access's (ACE, Jet, whatever) cast to DATETIME function CDATE(). As its name suggests, DATETIME always includes a time element so your literal values should reflect this fact. The ISO date format is understood perfectly by the SQL engine.

Best not to use BETWEEN for DATETIME in Access: it's modelled using a floating point type and anyhow time is a continuum ;)

DATE and TABLE are reserved words in the SQL Standards, ODBC and Jet 4.0 (and probably beyond) so are best avoided for a data element names:

Your predicates suggest open-open representation of periods (where neither its start date or the end date is included in the period), which is arguably the least popular choice. It makes me wonder if you meant to use closed-open representation (where neither its start date is included but the period ends immediately prior to the end date):

SELECT my_date
  FROM MyTable
 WHERE my_date >= #2008-09-01 00:00:00#
       AND my_date < #2010-09-01 00:00:00#;

Alternatively:

SELECT my_date
  FROM MyTable
 WHERE my_date >= CDate('2008-09-01 00:00:00')
       AND my_date < CDate('2010-09-01 00:00:00');

How to generate a random integer number from within a range

As said before modulo isn't sufficient because it skews the distribution. Heres my code which masks off bits and uses them to ensure the distribution isn't skewed.

static uint32_t randomInRange(uint32_t a,uint32_t b) {
    uint32_t v;
    uint32_t range;
    uint32_t upper;
    uint32_t lower;
    uint32_t mask;

    if(a == b) {
        return a;
    }

    if(a > b) {
        upper = a;
        lower = b;
    } else {
        upper = b;
        lower = a; 
    }

    range = upper - lower;

    mask = 0;
    //XXX calculate range with log and mask? nah, too lazy :).
    while(1) {
        if(mask >= range) {
            break;
        }
        mask = (mask << 1) | 1;
    }


    while(1) {
        v = rand() & mask;
        if(v <= range) {
            return lower + v;
        }
    }

}

The following simple code lets you look at the distribution:

int main() {

    unsigned long long int i;


    unsigned int n = 10;
    unsigned int numbers[n];


    for (i = 0; i < n; i++) {
        numbers[i] = 0;
    }

    for (i = 0 ; i < 10000000 ; i++){
        uint32_t rand = random_in_range(0,n - 1);
        if(rand >= n){
            printf("bug: rand out of range %u\n",(unsigned int)rand);
            return 1;
        }
        numbers[rand] += 1;
    }

    for(i = 0; i < n; i++) {
        printf("%u: %u\n",i,numbers[i]);
    }

}

Why am I getting "IndentationError: expected an indented block"?

in python intended block mean there is every thing must be written in manner in my case I written it this way

 def btnClick(numbers):
 global operator
 operator = operator + str(numbers)
 text_input.set(operator)

Note.its give me error,until I written it in this way such that "giving spaces " then its giving me a block as I am trying to show you in function below code

def btnClick(numbers):
___________________________
|global operator
|operator = operator + str(numbers)
|text_input.set(operator)

First letter capitalization for EditText

if you are writing styles in styles.xml then

remove android:inputType property and add below lines

<item name="android:capitalize">words</item>

How can I create objects while adding them into a vector?

Question 1:

   vectorOfGamers.push_back(Player)

This is problematic because you cannot directly push a class name into a vector. You can either push an object of class into the vector or push reference or pointer to class type into the vector. For example:

vectorOfGamers.push_back(Player(name, id)) 
  //^^assuming name and id are parameters to the vector, call Player constructor
  //^^In other words, push `instance`  of Player class into vector

Question 2:

These 3 classes derives from Gamer. Can I create vector to hold objects of Dealer, Bot and Player at the same time? How do I do that?

Yes you can. You can create a vector of pointers that points to the base class Gamer. A good choice is to use a vector of smart_pointer, therefore, you do not need to manage pointer memory by yourself. Since the other three classes are derived from Gamer, based on polymorphism, you can assign derived class objects to base class pointers. You may find more information from this post: std::vector of objects / pointers / smart pointers to pass objects (buss error: 10)?

Connecting PostgreSQL 9.2.1 with Hibernate

If the project is maven placed it in src/main/resources, in the package phase it will copy it in ../WEB-INF/classes/hibernate.cfg.xml

How do I get DOUBLE_MAX?

Using double to store large integers is dubious; the largest integer that can be stored reliably in double is much smaller than DBL_MAX. You should use long long, and if that's not enough, you need your own arbitrary-precision code or an existing library.

List of tuples to dictionary

Just call dict() on the list of tuples directly

>>> my_list = [('a', 1), ('b', 2)]
>>> dict(my_list)
{'a': 1, 'b': 2}

How do I configure HikariCP in my Spring Boot app in my application.properties files?

With the later spring-boot releases switching to Hikari can be done entirely in configuration. I'm using 1.5.6.RELEASE and this approach works.

build.gradle:

compile "com.zaxxer:HikariCP:2.7.3"

application YAML

spring:
  datasource:
    type: com.zaxxer.hikari.HikariDataSource
    hikari:
      idleTimeout: 60000
      minimumIdle: 2
      maximumPoolSize: 20
      connectionTimeout: 30000
      poolName: MyPoolName
      connectionTestQuery: SELECT 1

Change connectionTestQuery to suit your underlying DB. That's it, no code required.

Output first 100 characters in a string

Most of previous examples will raise an exception in case your string is not long enough.

Another approach is to use 'yourstring'.ljust(100)[:100].strip().

This will give you first 100 chars. You might get a shorter string in case your string last chars are spaces.

NSCameraUsageDescription in iOS 10.0 runtime crash?

You have to add this below key in info.plist.

NSCameraUsageDescription Or Privacy - Camera usage description

And add description of usage.

Detailed screenshots are available in this link

How to trigger SIGUSR1 and SIGUSR2?

They are user-defined signals, so they aren't triggered by any particular action. You can explicitly send them programmatically:

#include <signal.h>

kill(pid, SIGUSR1);

where pid is the process id of the receiving process. At the receiving end, you can register a signal handler for them:

#include <signal.h>

void my_handler(int signum)
{
    if (signum == SIGUSR1)
    {
        printf("Received SIGUSR1!\n");
    }
}

signal(SIGUSR1, my_handler);

Passing Arrays to Function in C++

The syntaxes

int[]

and

int[X] // Where X is a compile-time positive integer

are exactly the same as

int*

when in a function parameter list (I left out the optional names).

Additionally, an array name decays to a pointer to the first element when passed to a function (and not passed by reference) so both int firstarray[3] and int secondarray[5] decay to int*s.

It also happens that both an array dereference and a pointer dereference with subscript syntax (subscript syntax is x[y]) yield an lvalue to the same element when you use the same index.

These three rules combine to make the code legal and work how you expect; it just passes pointers to the function, along with the length of the arrays which you cannot know after the arrays decay to pointers.

Add image to layout in ruby on rails

In a Ruby on Rails project by default the root of the HTML source for the server is the public directory. So your link would be:

<img src="images/rss.jpg" alt="rss feed" />

But it is best practice in a Rails project to use the built in helper:

<%= image_tag("rss.jpg", :alt => "rss feed") %>

That will create the correct image link plus if you ever add assert servers, etc it will work with those.

Access And/Or exclusions

Seeing that it appears you are running using the SQL syntax, try with the correct wild card.

SELECT * FROM someTable WHERE (someTable.Field NOT LIKE '%RISK%') AND (someTable.Field NOT LIKE '%Blah%') AND someTable.SomeOtherField <> 4;

Flash CS4 refuses to let go

Also, to use your new namespaced class you can also do

var jenine:com.newnamespace.subspace.Jenine = com.newnamespace.subspace.Jenine()

Preloading CSS Images

how about loading that background image somewhere hidden. That way it will be loaded when the page is opened and wont take any time once the form is created using ajax:

body {
background: #ffffff url('img_tree.png') no-repeat -100px -100px;
}

Is the practice of returning a C++ reference variable evil?

You should return a reference to an existing object that isn't going away immediately, and where you don't intend any transfer of ownership.

Never return a reference to a local variable or some such, because it won't be there to be referenced.

You can return a reference to something independent of the function, which you don't expect the calling function to take the responsibility for deleting. This is the case for the typical operator[] function.

If you are creating something, you should return either a value or a pointer (regular or smart). You can return a value freely, since it's going into a variable or expression in the calling function. Never return a pointer to a local variable, since it will go away.

Change CSS properties on click

Try this:

$('#foo').css({backgroundColor:'red', color:'white',fontSize:'44px'});

How to make HTML element resizable using pure Javascript?

Is simple:

Example:https://jsfiddle.net/RainStudios/mw786v1w/

var element = document.getElementById('element');
//create box in bottom-left
var resizer = document.createElement('div');
resizer.style.width = '10px';
resizer.style.height = '10px';
resizer.style.background = 'red';
resizer.style.position = 'absolute';
resizer.style.right = 0;
resizer.style.bottom = 0;
resizer.style.cursor = 'se-resize';
//Append Child to Element
element.appendChild(resizer);
//box function onmousemove
resizer.addEventListener('mousedown', initResize, false);

//Window funtion mousemove & mouseup
function initResize(e) {
   window.addEventListener('mousemove', Resize, false);
   window.addEventListener('mouseup', stopResize, false);
}
//resize the element
function Resize(e) {
   element.style.width = (e.clientX - element.offsetLeft) + 'px';
   element.style.height = (e.clientY - element.offsetTop) + 'px';
}
//on mouseup remove windows functions mousemove & mouseup
function stopResize(e) {
    window.removeEventListener('mousemove', Resize, false);
    window.removeEventListener('mouseup', stopResize, false);
}

Random shuffling of an array

I'm weighing in on this very popular question because nobody has written a shuffle-copy version. Style is borrowed heavily from Arrays.java, because who isn't pillaging Java technology these days? Generic and int implementations included.

   /**
    * Shuffles elements from {@code original} into a newly created array.
    *
    * @param original the original array
    * @return the new, shuffled array
    * @throws NullPointerException if {@code original == null}
    */
   @SuppressWarnings("unchecked")
   public static <T> T[] shuffledCopy(T[] original) {
      int originalLength = original.length; // For exception priority compatibility.
      Random random = new Random();
      T[] result = (T[]) Array.newInstance(original.getClass().getComponentType(), originalLength);

      for (int i = 0; i < originalLength; i++) {
         int j = random.nextInt(i+1);
         result[i] = result[j];
         result[j] = original[i];
      }

      return result;
   }


   /**
    * Shuffles elements from {@code original} into a newly created array.
    *
    * @param original the original array
    * @return the new, shuffled array
    * @throws NullPointerException if {@code original == null}
    */
   public static int[] shuffledCopy(int[] original) {
      int originalLength = original.length;
      Random random = new Random();
      int[] result = new int[originalLength];

      for (int i = 0; i < originalLength; i++) {
         int j = random.nextInt(i+1);
         result[i] = result[j];
         result[j] = original[i];
      }

      return result;
   }

How to run a function in jquery

 
function doosomething ()
{
  //Doo something
}


$(function () {


  $("div.class").click(doosomething);

  $("div.secondclass").click(doosomething);

});

How to put individual tags for a scatter plot

Perhaps use plt.annotate:

import numpy as np
import matplotlib.pyplot as plt

N = 10
data = np.random.random((N, 4))
labels = ['point{0}'.format(i) for i in range(N)]

plt.subplots_adjust(bottom = 0.1)
plt.scatter(
    data[:, 0], data[:, 1], marker='o', c=data[:, 2], s=data[:, 3] * 1500,
    cmap=plt.get_cmap('Spectral'))

for label, x, y in zip(labels, data[:, 0], data[:, 1]):
    plt.annotate(
        label,
        xy=(x, y), xytext=(-20, 20),
        textcoords='offset points', ha='right', va='bottom',
        bbox=dict(boxstyle='round,pad=0.5', fc='yellow', alpha=0.5),
        arrowprops=dict(arrowstyle = '->', connectionstyle='arc3,rad=0'))

plt.show()

enter image description here

Get Absolute Position of element within the window in wpf

Since .NET 3.0, you can simply use *yourElement*.TranslatePoint(new Point(0, 0), *theContainerOfYourChoice*).

This will give you the point 0, 0 of your button, but towards the container. (You can also give an other point that 0, 0)

Check here for the doc.

Watermark / hint text / placeholder TextBox

Simple solution using style:

<TextBox>
    <TextBox.Style>
        <Style TargetType="TextBox" xmlns:sys="clr-namespace:System;assembly=mscorlib">
            <Style.Resources>
                <VisualBrush x:Key="CueBannerBrush" AlignmentX="Left" AlignmentY="Center" Stretch="None">
                    <VisualBrush.Visual>
                        <Label Content="MM:SS:HH AM/PM" Foreground="LightGray" />
                    </VisualBrush.Visual>
                </VisualBrush>
            </Style.Resources>
            <Style.Triggers>
                <Trigger Property="Text" Value="{x:Static sys:String.Empty}">
                    <Setter Property="Background" Value="{StaticResource CueBannerBrush}" />
                </Trigger>
                <Trigger Property="Text" Value="{x:Null}">
                    <Setter Property="Background" Value="{StaticResource CueBannerBrush}" />
                </Trigger>
                <Trigger Property="IsKeyboardFocused" Value="True">
                    <Setter Property="Background" Value="White" />
                </Trigger>
            </Style.Triggers>
        </Style>
    </TextBox.Style>
</TextBox>

Great solution:

https://code.msdn.microsoft.com/windowsdesktop/In-place-hit-messages-for-18db3a6c

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

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

How to use ternary operator in razor (specifically on HTML attributes)?

I have a field named IsActive in table rows that's True when an item has been deleted. This code applies a CSS class named strikethrough only to deleted items. You can see how it uses the C# Ternary Operator:

<tr class="@(@businesstypes.IsActive ? "" : "strikethrough")">

Autoreload of modules in IPython

If you add file ipython_config.py into the ~/.ipython/profile_default directory with lines like below, then the autoreload functionality will be loaded on IPython startup (tested on 2.0.0):

print "--------->>>>>>>> ENABLE AUTORELOAD <<<<<<<<<------------"

c = get_config()
c.InteractiveShellApp.exec_lines = []
c.InteractiveShellApp.exec_lines.append('%load_ext autoreload')
c.InteractiveShellApp.exec_lines.append('%autoreload 2')

HTML: Is it possible to have a FORM tag in each TABLE ROW in a XHTML valid way?

I had a similar question and this answer in question HTML: table of forms? solved it for me. (Not sure if it is XHTML, but it works in an HTML5 browser.)

You can use css to give table layout to other elements.

.table { display: table; } 
.table>* { display: table-row; }
.table>*>* { display: table-cell; }

Then you use the following valid html.

<div class="table"> 
    <form>
        <div>snake<input type="hidden" name="cartitem" value="55"></div>
        <div><input name="count" value="4" /></div>
    </form>
</div>

How do I install SciPy on 64 bit Windows?

Okey, here I am going to share what I have done to install SciPy on my Windows PC without the command line.

My PC configuration is Windows 7 64-bit and Python 2.7

  • First I download the required packages form http://www.lfd.uci.edu/~gohlke/pythonlibs/ (which version match your configuration EX: cp27==>python2.7 & cp35==>3.5)
  • Second I extract the file using 7-Zip (also can be used any zipper like WinRAR)
  • Third I copy the scipy folder which I extracted and paste it into C:\Python27\Lib\site-packages (or put it where the exact location is in your PC like ..\..\Lib\site-packages)

NOTE: You have to install NumPy first before installing SciPy in this same way.

Round double value to 2 decimal places

To remove the decimals from your double, take a look at this output

Obj C

double hellodouble = 10.025;
NSLog(@"Your value with 2 decimals: %.2f", hellodouble);
NSLog(@"Your value with no decimals: %.0f", hellodouble);

The output will be:

10.02 
10

Swift 2.1 and Xcode 7.2.1

let hellodouble:Double = 3.14159265358979
print(String(format:"Your value with 2 decimals: %.2f", hellodouble))
print(String(format:"Your value with no decimals: %.0f", hellodouble))

The output will be:

3.14 
3

Creating a PHP header/footer

You can use this for header: Important: Put the following on your PHP pages that you want to include the content.

<?php
//at top:
require('header.php'); 
 ?>
 <?php
// at bottom:
require('footer.php');
?>

You can also include a navbar globaly just use this instead:

 <?php
 // At top:
require('header.php'); 
 ?>
  <?php
// At bottom:
require('footer.php');
 ?>
 <?php
 //Wherever navbar goes:
require('navbar.php'); 
?>

In header.php:

 <!DOCTYPE html>
 <html lang="en">
 <head>
    <meta charset="utf-8">
 <meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no">
 </head>
 <body>

Do Not close Body or Html tags!
Include html here:

 <?php
 //Or more global php here:

 ?>

Footer.php:

Code here:

<?php
//code

?>

Navbar.php:

<p> Include html code here</p>
<?php
 //Include Navbar PHP code here
 
?>

Benifits:

  • Cleaner main php file (index.php) script.
  • Change the header or footer. etc to change it on all pages with the include— Good for alerts on all pages etc...
  • Time Saving!
  • Faster page loads!
  • you can have as many files to include as needed!
  • server sided!

Oracle - Insert New Row with Auto Incremental ID

the complete know how, i have included a example of the triggers and sequence

create table temasforo(
idtemasforo NUMBER(5) PRIMARY KEY,
autor       VARCHAR2(50) NOT NULL,
fecha       DATE DEFAULT (sysdate),
asunto      LONG  );

create sequence temasforo_seq
  start with 1
  increment by 1
  nomaxvalue;

create or replace
trigger temasforo_trigger
  before insert on temasforo
  referencing OLD as old NEW as new
  for each row
  begin
      :new.idtemasforo:=temasforo_seq.nextval;
    end;

reference: http://thenullpointerexceptionx.blogspot.mx/2013/06/llaves-primarias-auto-incrementales-en.html

Go to first line in a file in vim?

Go to first line

  • :1

  • or Ctrl + Home

Go to last line

  • :%

  • or Ctrl + End

Go to another line (f.i. 27)

  • :27

[Works On VIM 7.4 (2016) and 8.0 (2018)]

Make one div visible and another invisible

I don't think that you really want an iframe, do you?

Unless you're doing something weird, you should be getting your results back as JSON or (in the worst case) XML, right?

For your white box / extra space issue, try

style="display: none;"

instead of

style="visibility: hidden;"

Upgrade to python 3.8 using conda

Now that the new anaconda individual edition 2020 distribution is out, the procedure that follows is working:

Update conda in your base env:

conda update conda

Create a new environment for Python 3.8, specifying anaconda for the full distribution specification, not just the minimal environment:

conda create -n py38 python=3.8 anaconda

Activate the new environment:

conda activate py38

python --version
Python 3.8.1

Number of packages installed: 303

Or you can do:

conda create -n py38 anaconda=2020.02 python=3.8

--> UPDATE: Finally, Anaconda3-2020.07 is out with core Python 3.8.3

You can download Anaconda with Python 3.8 from https://www.anaconda.com/products/individual

PHP include relative path

You could always include it using __DIR__:

include(dirname(__DIR__).'/config.php');

__DIR__ is a 'magical constant' and returns the directory of the current file without the trailing slash. It's actually an absolute path, you just have to concatenate the file name to __DIR__. In this case, as we need to ascend a directory we use PHP's dirname which ascends the file tree, and from here we can access config.php.

You could set the root path in this method too:

define('ROOT_PATH', dirname(__DIR__) . '/');

in test.php would set your root to be at the /root/ level.

include(ROOT_PATH.'config.php');

Should then work to include the config file from where you want.

How do you configure tomcat to bind to a single ip address (localhost) instead of all addresses?

it's well documented here:

https://cwiki.apache.org/confluence/display/TOMCAT/Connectors#Connectors-Q6

How do I bind to a specific ip address? - "Each Connector element allows an address property. See the HTTP Connector docs or the AJP Connector docs". And HTTP Connectors docs:

http://tomcat.apache.org/tomcat-7.0-doc/config/http.html

Standard Implementation -> address

"For servers with more than one IP address, this attribute specifies which address will be used for listening on the specified port. By default, this port will be used on all IP addresses associated with the server."

How can I use a JavaScript variable as a PHP variable?

You can take all values like this:

$abc = "<script>document.getElementByID('yourid').value</script>";

How to update Xcode from command line

I was trying to use the React-Native Expo app with create-react-native-app but for some reason it would launch my simulator and just hang without loading the app. The above answer by ipinak above reset the Xcode CLI tools because attempting to update to most recent Xcode CLI was not working. the two commands are:

rm -rf /Library/Developer/CommandLineTools
xcode-select --install

This process take time because of the download. I am leaving this here for any other would be searches for this specific React-Native Expo fix.

Cannot Resolve Collation Conflict

The thing about collations is that although the database has its own collation, every table, and every column can have its own collation. If not specified it takes the default of its parent object, but can be different.

When you change collation of the database, it will be the new default for all new tables and columns, but it doesn't change the collation of existing objects inside the database. You have to go and change manually the collation of every table and column.

Luckily there are scripts available on the internet that can do the job. I am not going to recommend any as I haven't tried them but here are few links:

http://www.codeproject.com/Articles/302405/The-Easy-way-of-changing-Collation-of-all-Database

Update Collation of all fields in database on the fly

http://www.sqlservercentral.com/Forums/Topic820675-146-1.aspx

If you need to have different collation on two objects or can't change collations - you can still JOIN between them using COLLATE command, and choosing the collation you want for join.

SELECT * FROM A JOIN B ON A.Text = B.Text COLLATE Latin1_General_CI_AS

or using default database collation:

SELECT * FROM A JOIN B ON A.Text = B.Text COLLATE DATABASE_DEFAULT

How to use img src in vue.js?

Try this:

<img v-bind:src="'/media/avatars/' + joke.avatar" />

Don't forget single quote around your path string. also in your data check you have correctly defined image variable.

joke: {
  avatar: 'image.jpg'
}

A working demo here: http://jsbin.com/pivecunode/1/edit?html,js,output

Moment Js UTC to Local Time

Here is what I do using Intl api:

let currentTimeZone = new Intl.DateTimeFormat().resolvedOptions().timeZone; // For example: Australia/Sydney

this will return a time zone name. Pass this parameter to the following function to get the time

let dateTime = new Date(date).toLocaleDateString('en-US',{ timeZone: currentTimeZone, hour12: true});

let time = new Date(date).toLocaleTimeString('en-US',{ timeZone: currentTimeZone, hour12: true});

you can also format the time with moment like this:

moment(new Date(`${dateTime} ${time}`)).format('YYYY-MM-DD[T]HH:mm:ss');

Getting "NoSuchMethodError: org.hamcrest.Matcher.describeMismatch" when running test in IntelliJ 10.5

The problem was that the wrong hamcrest.Matcher, not hamcrest.MatcherAssert, class was being used. That was being pulled in from a junit-4.8 dependency one of my dependencies was specifying.

To see what dependencies (and versions) are included from what source while testing, run:

mvn dependency:tree -Dscope=test

How can I set the font-family & font-size inside of a div?

Append a semicolon to the following line to fix the issue. 

font-family:    Arial, Helvetica, sans-serif;

Why is setState in reactjs Async instead of Sync?

I know this question is old, but it has been causing a lot of confusion for many reactjs users for a long time, including me. Recently Dan Abramov (from the react team) just wrote up a great explanation as to why the nature of setState is async:

https://github.com/facebook/react/issues/11527#issuecomment-360199710

setState is meant to be asynchronous, and there are a few really good reasons for that in the linked explanation by Dan Abramov. This doesn't mean it will always be asynchronous - it mainly means that you just can't depend on it being synchronous. ReactJS takes into consideration many variables in the scenario that you're changing the state in, to decide when the state should actually be updated and your component rerendered.
A simple example to demonstrate this, is that if you call setState as a reaction to a user action, then the state will probably be updated immediately (although, again, you can't count on it), so the user won't feel any delay, but if you call setState in reaction to an ajax call response or some other event that isn't triggered by the user, then the state might be updated with a slight delay, since the user won't really feel this delay, and it will improve performance by waiting to batch multiple state updates together and rerender the DOM fewer times.

How to set margin with jquery?

try 

el.css('margin-left',mrg+'px');

Huge performance difference when using group by vs distinct

The two queries express the same question. Apparently the query optimizer chooses two different execution plans. My guess would be that the distinct approach is executed like:

  • Copy all business_key values to a temporary table
  • Sort the temporary table
  • Scan the temporary table, returning each item that is different from the one before it

The group by could be executed like:

  • Scan the full table, storing each value of business key in a hashtable
  • Return the keys of the hashtable

The first method optimizes for memory usage: it would still perform reasonably well when part of the temporary table has to be swapped out. The second method optimizes for speed, but potentially requires a large amount of memory if there are a lot of different keys.

Since you either have enough memory or few different keys, the second method outperforms the first. It's not unusual to see performance differences of 10x or even 100x between two execution plans.

MySQL Workbench: How to keep the connection alive

In 5.2.47 (at least on mac), go the location of the preferences is: MySQLWorkbench->Preferences->SQL Editor

Then you'll see both:

DBMS connection keep-alive interval (in seconds): DBMS connection read time out (in seconds):

The latter is where you'll want to up the limit from 600 to something a bit more.

How do I set up cron to run a file just once at a specific time?

You could put a crontab file in /etc/cron.d which would run a script that would run your command and then delete the crontab file in /etc/cron.d. Of course, that means your script would need to run as root.

Bash integer comparison

This script works!

#/bin/bash
if [[ ( "$#" < 1 ) || ( !( "$1" == 1 ) && !( "$1" == 0 ) ) ]] ; then
    echo this script requires a 1 or 0 as first parameter.
else
    echo "first parameter is $1"
    xinput set-prop 12 "Device Enabled" $0
fi

But this also works, and in addition keeps the logic of the OP, since the question is about calculations. Here it is with only arithmetic expressions:

#/bin/bash
if (( $# )) && (( $1 == 0 || $1 == 1 )); then
    echo "first parameter is $1"
    xinput set-prop 12 "Device Enabled" $0
else
    echo this script requires a 1 or 0 as first parameter.
fi

The output is the same1:

$ ./tmp.sh 
this script requires a 1 or 0 as first parameter.

$ ./tmp.sh 0
first parameter is 0

$ ./tmp.sh 1
first parameter is 1

$ ./tmp.sh 2
this script requires a 1 or 0 as first parameter.

[1] the second fails if the first argument is a string

In C#, how to check if a TCP port is available?

 
TcpClient c;

//I want to check here if port is free.
c = new TcpClient(ip, port);

...how can I first check if a certain port is free on my machine?

I mean that it is not in use by any other application. If an application is using a port others can't use it until it becomes free. – Ali

You have misunderstood what's happening here.

TcpClient(...) parameters are of server ip and server port you wish to connect to.

The TcpClient selects a transient local port from the available pool to communicate to the server. There's no need to check for the availability of the local port as it is automatically handled by the winsock layer.

In case you can't connect to the server using the above code fragment, the problem could be one or more of several. (i.e. server ip and/or port is wrong, remote server not available, etc..)

How to run bootRun with spring profile via gradle task

Spring Boot v2 Gradle plugin docs provide an answer:

6.1. Passing arguments to your application

Like all JavaExec tasks, arguments can be passed into bootRun from the command line using --args='<arguments>' when using Gradle 4.9 or later.

To run server with active profile set to dev:

$ ./gradlew bootRun --args='--spring.profiles.active=dev'

How to Migrate to WKWebView?

WkWebView is much faster and reliable than UIWebview according to the Apple docs. Here, I posted my WkWebViewController.

import UIKit
import WebKit

class WebPageViewController: UIViewController,UINavigationControllerDelegate,UINavigationBarDelegate,WKNavigationDelegate{

    var webView: WKWebView?
    var webUrl="http://www.nike.com"

    override func viewWillAppear(animated: Bool){
        super.viewWillAppear(true)
        navigationController!.navigationBar.hidden = false

    }
    override func viewDidLoad()
    {
        /* Create our preferences on how the web page should be loaded */
        let preferences = WKPreferences()
        preferences.javaScriptEnabled = false

        /* Create a configuration for our preferences */
        let configuration = WKWebViewConfiguration()
        configuration.preferences = preferences

        /* Now instantiate the web view */
        webView = WKWebView(frame: view.bounds, configuration: configuration)

        if let theWebView = webView{
            /* Load a web page into our web view */
            let url = NSURL(string: self.webUrl)
            let urlRequest = NSURLRequest(URL: url!)
            theWebView.loadRequest(urlRequest)
            theWebView.navigationDelegate = self
            view.addSubview(theWebView)

        }


    }
    /* Start the network activity indicator when the web view is loading */
    func webView(webView: WKWebView,didStartProvisionalNavigation navigation: WKNavigation){
            UIApplication.sharedApplication().networkActivityIndicatorVisible = true
    }

    /* Stop the network activity indicator when the loading finishes */
    func webView(webView: WKWebView,didFinishNavigation navigation: WKNavigation){
            UIApplication.sharedApplication().networkActivityIndicatorVisible = false
    }

    func webView(webView: WKWebView,
        decidePolicyForNavigationResponse navigationResponse: WKNavigationResponse,decisionHandler: ((WKNavigationResponsePolicy) -> Void)){
            //print(navigationResponse.response.MIMEType)
            decisionHandler(.Allow)

    }
    override func didReceiveMemoryWarning(){
        super.didReceiveMemoryWarning()
    }

}

Does a finally block always get executed in Java?

Because a finally block will always be called unless you call System.exit() (or the thread crashes).

Checking if a field contains a string

This should do the work

db.users.find({ username: { $in: [ /son/i ] } });

The i is just there to prevent restrictions of matching single cases of letters.

You can check the $regex documentation on MongoDB documentation. Here's a link: https://docs.mongodb.com/manual/reference/operator/query/regex/

Why do I get TypeError: can't multiply sequence by non-int of type 'float'?

The problem is that salesAmount is being set to a string. If you enter the variable in the python interpreter and hit enter, you'll see the value entered surrounded by quotes. For example, if you entered 56.95 you'd see:

>>> sales_amount = raw_input("[Insert sale amount]: ")
[Insert sale amount]: 56.95
>>> sales_amount
'56.95'

You'll want to convert the string into a float before multiplying it by sales tax. I'll leave that for you to figure out. Good luck!

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

make_unique is an upcoming C++14 feature and thus might not be available on your compiler, even if it is C++11 compliant.

You can however easily roll your own implementation:

template<typename T, typename... Args>
std::unique_ptr<T> make_unique(Args&&... args) {
    return std::unique_ptr<T>(new T(std::forward<Args>(args)...));
}

(FYI, here is the final version of make_unique that was voted into C++14. This includes additional functions to cover arrays, but the general idea is still the same.)

How can I get a list of all values in select box?

Change:

x.length

to:

x.options.length

Link to fiddle

And I agree with Abraham - you might want to use text instead of value

Update
The reason your fiddle didn't work was because you chose the option: "onLoad" instead of: "No wrap - in "

How to implement a FSM - Finite State Machine in Java

Consider the easy, lightweight Java library EasyFlow. From their docs:

With EasyFlow you can:

  • implement complex logic but keep your code simple and clean
  • handle asynchronous calls with ease and elegance
  • avoid concurrency by using event-driven programming approach
  • avoid StackOverflow error by avoiding recursion
  • simplify design, programming and testing of complex java applications

groovy: safely find a key in a map and return its value

The whole point of using Maps is direct access. If you know for sure that the value in a map will never be Groovy-false, then you can do this:

def mymap = [name:"Gromit", likes:"cheese", id:1234]
def key = "likes"

if(mymap[key]) {
    println mymap[key]
}

However, if the value could potentially be Groovy-false, you should use:

if(mymap.containsKey(key)) {
    println mymap[key]
}

The easiest solution, though, if you know the value isn't going to be Groovy-false (or you can ignore that), and want a default value, is like this:

def value = mymap[key] ?: "default"

All three of these solutions are significantly faster than your examples, because they don't scan the entire map for keys. They take advantage of the HashMap (or LinkedHashMap) design that makes direct key access nearly instantaneous.

Automatic prune with Git fetch or pull

Since git 1.8.5 (Q4 2013):

"git fetch" (hence "git pull" as well) learned to check "fetch.prune" and "remote.*.prune" configuration variables and to behave as if the "--prune" command line option was given.

That means that, if you set remote.origin.prune to true:

git config remote.origin.prune true

Any git fetch or git pull will automatically prune.

Note: Git 2.12 (Q1 2017) will fix a bug related to this configuration, which would make git remote rename misbehave.
See "How do I rename a git remote?".

See more at commit 737c5a9:

Without "git fetch --prune", remote-tracking branches for a branch the other side already has removed will stay forever.
Some people want to always run "git fetch --prune".

To accommodate users who want to either prune always or when fetching from a particular remote, add two new configuration variables "fetch.prune" and "remote.<name>.prune":

  • "fetch.prune" allows to enable prune for all fetch operations.
  • "remote.<name>.prune" allows to change the behaviour per remote.

The latter will naturally override the former, and the --[no-]prune option from the command line will override the configured default.

Since --prune is a potentially destructive operation (Git doesn't keep reflogs for deleted references yet), we don't want to prune without users consent, so this configuration will not be on by default.

How do I compare two strings in Perl?

The obvious subtext of this question is:

why can't you just use == to check if two strings are the same?

Perl doesn't have distinct data types for text vs. numbers. They are both represented by the type "scalar". Put another way, strings are numbers if you use them as such.

if ( 4 == "4" ) { print "true"; } else { print "false"; }
true

if ( "4" == "4.0" ) { print "true"; } else { print "false"; }
true

print "3"+4
7

Since text and numbers aren't differentiated by the language, we can't simply overload the == operator to do the right thing for both cases. Therefore, Perl provides eq to compare values as text:

if ( "4" eq "4.0" ) { print "true"; } else { print "false"; }
false

if ( "4.0" eq "4.0" ) { print "true"; } else { print "false"; }
true

In short:

  • Perl doesn't have a data-type exclusively for text strings
  • use == or !=, to compare two operands as numbers
  • use eq or ne, to compare two operands as text

There are many other functions and operators that can be used to compare scalar values, but knowing the distinction between these two forms is an important first step.

Pandas aggregate count distinct

How about either of:

>>> df
         date  duration user_id
0  2013-04-01        30    0001
1  2013-04-01        15    0001
2  2013-04-01        20    0002
3  2013-04-02        15    0002
4  2013-04-02        30    0002
>>> df.groupby("date").agg({"duration": np.sum, "user_id": pd.Series.nunique})
            duration  user_id
date                         
2013-04-01        65        2
2013-04-02        45        1
>>> df.groupby("date").agg({"duration": np.sum, "user_id": lambda x: x.nunique()})
            duration  user_id
date                         
2013-04-01        65        2
2013-04-02        45        1

python ValueError: invalid literal for float()

Watch out for possible unintended literals in your argument

for example you can have a space within your argument, rendering it to a string / literal:

float(' 0.33')

After making sure the unintended space did not make it into the argument, I was left with:

float(0.33)

Like this it works like a charm.

Take away is: Pay Attention for unintended literals (e.g. spaces that you didn't see) within your input.

Swift - Remove " character from string

Here is the swift 3 updated answer

var editedText = myLabel.text?.replacingOccurrences(of: "\"", with: "")

Null Character (\0)
Backslash (\\)
Horizontal Tab (\t)
Line Feed (\n)
Carriage Return (\r)
Double Quote (\")
Single Quote (\')
Unicode scalar (\u{n})

SQL Server : GROUP BY clause to get comma-separated values

 
SELECT  [ReportId], 
        SUBSTRING(d.EmailList,1, LEN(d.EmailList) - 1) EmailList
FROM
        (
            SELECT DISTINCT [ReportId]
            FROM Table1
        ) a
        CROSS APPLY
        (
            SELECT [Email] + ', ' 
            FROM Table1 AS B 
            WHERE A.[ReportId] = B.[ReportId]
            FOR XML PATH('')
        ) D (EmailList)

SQLFiddle Demo

Laravel 4: Redirect to a given url

You can also use redirect() method like this:-

return redirect('https://stackoverflow.com/');

Invoking a jQuery function after .each() has completed

Ok, this might be a little after the fact, but .promise() should also achieve what you're after.

Promise documentation

An example from a project i'm working on:

$( '.panel' )
    .fadeOut( 'slow')
    .promise()
    .done( function() {
        $( '#' + target_panel ).fadeIn( 'slow', function() {});
    });

:)

Error: Java: invalid target release: 11 - IntelliJ IDEA

In your pom.xml file inside that <java.version> write "8" instead write "11" ,and RECOMPILE your pom.xml file And tadaaaaaa it works !

What are the aspect ratios for all Android phone and tablet devices?

The Sony Tablet P is old, but it can switch between 32:15 and 32:30 for each app in landscape mode, and vice-versa in portrait mode, so that's a minimum range to aim for

Omitting the second expression when using the if-else shorthand

Technically, putting null or 0, or just some random value there works (since you are not using the return value). However, why are you using this construct instead of the if construct? It is less obvious what you are trying to do when you write code this way, as you may confuse people with the no-op (null in your case).

How to execute mongo commands through shell scripts?

In my setup I have to use: 

mongo --host="the.server.ip:port" databaseName theScript.js

How to add color to Github's README.md file

I'm inclined to agree with Qwertman that it's not currently possible to specify color for text in GitHub markdown, at least not through HTML.

GitHub does allow some HTML elements and attributes, but only certain ones (see their documentation about their HTML sanitization). They do allow p and div tags, as well as color attribute. However, when I tried using them in a markdown document on GitHub, it didn't work. I tried the following (among other variations), and they didn't work:

  • <p style='color:red'>This is some red text.</p>
  • <font color="red">This is some text!</font>
  • These are <b style='color:red'>red words</b>.

As Qwertman suggested, if you really must use color you could do it in a README.html and refer them to it.

AngularJS routing without the hash '#'

Using HTML5 mode requires URL rewriting on server side, basically you have to rewrite all your links to entry point of your application (e.g. index.html). Requiring a <base> tag is also important for this case, as it allows AngularJS to differentiate between the part of the url that is the application base and the path that should be handled by the application. For more information, see AngularJS Developer Guide - Using $location HTML5 mode Server Side.

Update

How to: Configure your server to work with html5Mode1

When you have html5Mode enabled, the # character will no longer be used in your urls. The # symbol is useful because it requires no server side configuration. Without #, the url looks much nicer, but it also requires server side rewrites. Here are some examples:

Apache Rewrites

<VirtualHost *:80>
    ServerName my-app

    DocumentRoot /path/to/app

    <Directory /path/to/app>
        RewriteEngine on

        # Don't rewrite files or directories
        RewriteCond %{REQUEST_FILENAME} -f [OR]
        RewriteCond %{REQUEST_FILENAME} -d
        RewriteRule ^ - [L]

        # Rewrite everything else to index.html to allow html5 state links
        RewriteRule ^ index.html [L]
    </Directory>
</VirtualHost>

Nginx Rewrites

server {
    server_name my-app;

    index index.html;

    root /path/to/app;

    location / {
        try_files $uri $uri/ /index.html;
    }
}

Azure IIS Rewrites

<system.webServer>
  <rewrite>
    <rules> 
      <rule name="Main Rule" stopProcessing="true">
        <match url=".*" />
        <conditions logicalGrouping="MatchAll">
          <add input="{REQUEST_FILENAME}" matchType="IsFile" negate="true" />
          <add input="{REQUEST_FILENAME}" matchType="IsDirectory" negate="true" />
        </conditions>
        <action type="Rewrite" url="/" />
      </rule>
    </rules>
  </rewrite>
</system.webServer>

Express Rewrites

var express = require('express');
var app = express();

app.use('/js', express.static(__dirname + '/js'));
app.use('/dist', express.static(__dirname + '/../dist'));
app.use('/css', express.static(__dirname + '/css'));
app.use('/partials', express.static(__dirname + '/partials'));

app.all('/*', function(req, res, next) {
    // Just send the index.html for other files to support HTML5Mode
    res.sendFile('index.html', { root: __dirname });
});

app.listen(3006); //the port you want to use

See also

How to read all files in a folder from Java?

 
package com;


import java.io.File;

/**
 *
 * @author ?Mukesh
 */
public class ListFiles {

     static File mainFolder = new File("D:\\Movies");

     public static void main(String[] args)
     {
         ListFiles lf = new ListFiles();
         lf.getFiles(lf.mainFolder);

         long fileSize = mainFolder.length();
             System.out.println("mainFolder size in bytes is: " + fileSize);
             System.out.println("File size in KB is : " + (double)fileSize/1024);
             System.out.println("File size in MB is :" + (double)fileSize/(1024*1024));
     }
     public void getFiles(File f){
         File files[];
         if(f.isFile())
             System.out.println(f.getAbsolutePath());
         else{
             files = f.listFiles();
             for (int i = 0; i < files.length; i++) {
                 getFiles(files[i]);
             }
         }
     }
}

Centering text in a table in Twitter Bootstrap

I had the same problem and a better way to solve it without using !important was defining the following in my CSS:

table th.text-center, table td.text-center { 
    text-align: center;
}

That way the specifity of the text-center class works correctly in tables.

How can I use threading in Python?

Here is the very simple example of CSV import using threading. (Library inclusion may differ for different purpose.)

Helper Functions:

from threading import Thread
from project import app
import csv


def import_handler(csv_file_name):
    thr = Thread(target=dump_async_csv_data, args=[csv_file_name])
    thr.start()

def dump_async_csv_data(csv_file_name):
    with app.app_context():
        with open(csv_file_name) as File:
            reader = csv.DictReader(File)
            for row in reader:
                # DB operation/query

Driver Function:

import_handler(csv_file_name)

Access Control Origin Header error using Axios in React Web throwing error in Chrome

In node js(backend), Use cors npm module

$ npm install cors

Then add these lines to support Access-Control-Allow-Origin,

const express = require('express')
const app = express()
app.use(cors())
app.get('/products/:id', cors(), function (req, res, next) {
            res.json({msg: 'This is CORS-enabled for a Single Route'});
});

You can achieve the same, without requiring any external module

app.use(function(req, res, next) {
            res.header("Access-Control-Allow-Origin", "*");
            res.header("Access-Control-Allow-Headers", "Origin, X-Requested-With, Content-Type, Accept");
            next();
});

Show history of a file?

git log -p will generate the a patch (the diff) for every commit selected. For a single file, use git log --follow -p $file.

If you're looking for a particular change, use git bisect to find the change in log(n) views by splitting the number of commits in half until you find where what you're looking for changed.

Also consider looking back in history using git blame to follow changes to the line in question if you know what that is. This command shows the most recent revision to affect a certain line. You may have to go back a few versions to find the first change where something was introduced if somebody has tweaked it over time, but that could give you a good start.

Finally, gitk as a GUI does show me the patch immediately for any commit I click on.

Example enter image description here:

How to use Greek symbols in ggplot2?

Simplest solution: Use Unicode Characters

No expression or other packages needed.
Not sure if this is a newer feature for ggplot, but it works. It also makes it easy to mix Greek and regular text (like adding '*' to the ticks)

Just use unicode characters within the text string. seems to work well for all options I can think of. Edit: previously it did not work in facet labels. This has apparently been fixed at some point.

library(ggplot2)
ggplot(mtcars, 
       aes(mpg, disp, color=factor(gear))) + 
  geom_point() + 
  labs(title="Title (\u03b1 \u03a9)", # works fine
       x= "\u03b1 \u03a9 x-axis title",    # works fine
       y= "\u03b1 \u03a9 y-axis title",    # works fine
       color="\u03b1 \u03a9 Groups:") +  # works fine
  scale_x_continuous(breaks = seq(10, 35, 5), 
                     labels = paste0(seq(10, 35, 5), "\u03a9*")) + # works fine; to label the ticks
  ggrepel::geom_text_repel(aes(label = paste(rownames(mtcars), "\u03a9*")), size =3) + # works fine 
  facet_grid(~paste0(gear, " Gears \u03a9"))

Created on 2019-08-28 by the reprex package (v0.3.0)

How to install Java SDK on CentOS?

On centos 7, I just do

sudo yum install java-sdk

I assume you have most common repo already. Centos just finds the correct SDK with the -devel sufix.

how to run the command mvn eclipse:eclipse

The m2e plugin uses it's own distribution of Maven, packaged with the plugin.

In order to use Maven from command line, you need to have it installed as a standalone application. Here is an instruction explaining how to do it in Windows

Once Maven is properly installed (i.e. be sure that MAVEN_HOME, JAVA_HOME and PATH variables are set correctly): you must run mvn eclipse:eclipse from the directory containing the pom.xml.

Why is @font-face throwing a 404 error on woff files?

The answer to this post was very helpful and a big time saver. However, I found that when using FontAwesome 4.50, I had to add an additional configuration for woff2 type of extension also as shown below else requests for woff2 type was giving a 404 error in Chrome's Developer Tools under Console> Errors.

According to the comment by S.Serp, the below configuration should be put within <system.webServer> tag.

<staticContent>
  <remove fileExtension=".woff" />
  <!-- In case IIS already has this mime type -->
  <mimeMap fileExtension=".woff" mimeType="application/x-font-woff" />
  <remove fileExtension=".woff2" />
  <!-- In case IIS already has this mime type -->
  <mimeMap fileExtension=".woff2" mimeType="application/x-font-woff2" />
</staticContent>

SQLDataReader Row Count

This will get you the row count, but will leave the data reader at the end.

dataReader.Cast<object>().Count();

Bootstrap 3 .col-xs-offset-* doesn't work?

instead of using col-md-offset-4 use instead offset-md-4, you no longer have to use col when you're offsetting. In your case use offset-xs-1 and this will work. make sure you've called the bootstrap.css folder into your html as follows .

Set cURL to use local virtual hosts

Does the server actually get the requests, and are you handling the host name (alias) properly?

after adding to my .hosts file

Check your webserver log, to see how the request came in...

curl has options to dump the request sent, and response received, it is called trace, which will will be saved to a file.

--trace

If you are missing host or header information - you can force those headers with the config option.

I would get the curl request working on the command line, and then try to implement in PHP.

the config option is

-K/--config

the options that are relevant in curl are here

--trace Enables a full trace dump of all incoming and outgoing data, including descriptive information, to the given output file. Use "-" as filename to have the output sent to stdout.

      This option overrides previous uses of -v/--verbose or --trace-ascii.

      If this option is used several times, the last one will be used.

-K/--config Specify which config file to read curl arguments from. The config file is a text file in which command line arguments can be written which then will be used as if they were written on the actual command line. Options and their parameters must be specified on the same config file line, separated by whitespace, colon, the equals sign or any combination thereof (however, the preferred separa- tor is the equals sign). If the parameter is to contain whitespace, the parameter must be enclosed within quotes. Within double quotes, the following escape sequences are available: \, \", \t, \n, \r and \v. A backslash preceding any other letter is ignored. If the first column of a config line is a '#' character, the rest of the line will be treated as a comment. Only write one option per physical line in the config file.

      Specify the filename to -K/--config as '-' to make curl read the file from stdin.

      Note that to be able to specify a URL in the config file, you need to specify it using the --url option, and not by simply writing the URL on its own line. So, it could look similar to this:

      url = "http://curl.haxx.se/docs/"

      Long option names can optionally be given in the config file without the initial double dashes.

      When curl is invoked, it always (unless -q is used) checks for a default config file and uses it if found. The default config file is checked for in the following places in this order:

      1) curl tries to find the "home dir": It first checks for the CURL_HOME and then the HOME environment variables. Failing that, it uses getpwuid() on UNIX-like systems (which  returns  the  home  dir
      given the current user in your system). On Windows, it then checks for the APPDATA variable, or as a last resort the '%USERPROFILE%\Application Data'.

      2)  On windows, if there is no _curlrc file in the home dir, it checks for one in the same dir the curl executable is placed. On UNIX-like systems, it will simply try to load .curlrc from the deter-
      mined home dir.

      # --- Example file ---
      # this is a comment
      url = "curl.haxx.se"
      output = "curlhere.html"
      user-agent = "superagent/1.0"

      # and fetch another URL too
      url = "curl.haxx.se/docs/manpage.html"
      -O
      referer = "http://nowhereatall.com/"
      # --- End of example file ---

      This option can be used multiple times to load multiple config files.

Python list directory, subdirectory, and files

Here is a one-liner:

import os

[val for sublist in [[os.path.join(i[0], j) for j in i[2]] for i in os.walk('./')] for val in sublist]
# Meta comment to ease selecting text

The outer most val for sublist in ... loop flattens the list to be one dimensional. The j loop collects a list of every file basename and joins it to the current path. Finally, the i loop iterates over all directories and sub directories.

This example uses the hard-coded path ./ in the os.walk(...) call, you can supplement any path string you like.

Note: os.path.expanduser and/or os.path.expandvars can be used for paths strings like ~/

Extending this example:

Its easy to add in file basename tests and directoryname tests.

For Example, testing for *.jpg files:

... for j in i[2] if j.endswith('.jpg')] ...

Additionally, excluding the .git directory:

... for i in os.walk('./') if '.git' not in i[0].split('/')]

How to 'insert if not exists' in MySQL?

Here is a PHP function that will insert a row only if all the specified columns values don't already exist in the table.

  • If one of the columns differ, the row will be added.

  • If the table is empty, the row will be added.

  • If a row exists where all the specified columns have the specified values, the row won't be added.

    function insert_unique($table, $vars)
{
  if (count($vars)) {
    $table = mysql_real_escape_string($table);
    $vars = array_map('mysql_real_escape_string', $vars);

    $req = "INSERT INTO `$table` (`". join('`, `', array_keys($vars)) ."`) ";
    $req .= "SELECT '". join("', '", $vars) ."' FROM DUAL ";
    $req .= "WHERE NOT EXISTS (SELECT 1 FROM `$table` WHERE ";

    foreach ($vars AS $col => $val)
      $req .= "`$col`='$val' AND ";

    $req = substr($req, 0, -5) . ") LIMIT 1";

    $res = mysql_query($req) OR die();
    return mysql_insert_id();
  }

  return False;
}

Example usage :

<?php
insert_unique('mytable', array(
  'mycolumn1' => 'myvalue1',
  'mycolumn2' => 'myvalue2',
  'mycolumn3' => 'myvalue3'
  )
);
?>

Vagrant error : Failed to mount folders in Linux guest

Try like it:

vagrant plugin install vagrant-vbguest

In Vagrantfile add:

config.vbguest.iso_path = "http://download.virtualbox.org/virtualbox/VERSION/VBoxGuestAdditions_VERSION.iso"
config.vbguest.auto_update = false
config.vbguest.installer_arguments = %w{--nox11 -- --force}

Run:

vagrant vbguest --do install -f -b

vagrant reload

How to delete the first row of a dataframe in R?

You can use negative indexing to remove rows, e.g.:

dat <- dat[-1, ]

Here is an example:

> dat <- data.frame(A = 1:3, B = 1:3)
> dat[-1, ]
  A B
2 2 2
3 3 3
> dat2 <- dat[-1, ]
> dat2
  A B
2 2 2
3 3 3

That said, you may have more problems than just removing the labels that ended up on row 1. It is more then likely that R has interpreted the data as text and thence converted to factors. Check what str(foo), where foo is your data object, says about the data types.

It sounds like you just need header = TRUE in your call to read in the data (assuming you read it in via read.table() or one of it's wrappers.)

How can I create a memory leak in Java?

As a lot of people have suggested, Resource Leaks are fairly easy to cause - like the JDBC examples. Actual Memory leaks are a bit harder - especially if you aren't relying on broken bits of the JVM to do it for you...

The ideas of creating objects that have a very large footprint and then not being able to access them aren't real memory leaks either. If nothing can access it then it will be garbage collected, and if something can access it then it's not a leak...

One way that used to work though - and I don't know if it still does - is to have a three-deep circular chain. As in Object A has a reference to Object B, Object B has a reference to Object C and Object C has a reference to Object A. The GC was clever enough to know that a two deep chain - as in A <--> B - can safely be collected if A and B aren't accessible by anything else, but couldn't handle the three-way chain...

HTML Image not displaying, while the src url works

my problem was not including the ../ before the image name

background-image: url("../image.png");

The ScriptManager must appear before any controls that need it

The ScriptManager is a web control that you register in the page using

<asp:ScriptManager ID="ScriptManger1" runat="Server" />

inside the Form tag

Simplest way to download and unzip files in Node.js cross-platform?

I was looking forward this for a long time, and found no simple working example, but based on these answers I created the downloadAndUnzip() function.

The usage is quite simple:

downloadAndUnzip('http://your-domain.com/archive.zip', 'yourfile.xml')
    .then(function (data) {
        console.log(data); // unzipped content of yourfile.xml in root of archive.zip
    })
    .catch(function (err) {
        console.error(err);
    });

And here is the declaration:

var AdmZip = require('adm-zip');
var request = require('request');

var downloadAndUnzip = function (url, fileName) {

    /**
     * Download a file
     * 
     * @param url
     */
    var download = function (url) {
        return new Promise(function (resolve, reject) {
            request({
                url: url,
                method: 'GET',
                encoding: null
            }, function (err, response, body) {
                if (err) {
                    return reject(err);
                }
                resolve(body);
            });
        });
    };

    /**
     * Unzip a Buffer
     * 
     * @param buffer
     * @returns {Promise}
     */
    var unzip = function (buffer) {
        return new Promise(function (resolve, reject) {

            var resolved = false;

            var zip = new AdmZip(buffer);
            var zipEntries = zip.getEntries(); // an array of ZipEntry records

            zipEntries.forEach(function (zipEntry) {
                if (zipEntry.entryName == fileName) {
                    resolved = true;
                    resolve(zipEntry.getData().toString('utf8'));
                }
            });

            if (!resolved) {
                reject(new Error('No file found in archive: ' + fileName));
            }
        });
    };


    return download(url)
        .then(unzip);
};

Any easy way to use icons from resources?

After adding the ICO file to your apps resources, you can use references it using My.Resources.YourIconNameWithoutExtension

For example if I had a file called Logo-square.ico added to my apps resources, I can set it to an icon with:

NotifyIcon1.Icon = My.Resources.Logo_square

How to hide elements without having them take space on the page?

display: none is solution, That's completely hides elements with its space.

Story about display:none and visibility: hidden

visibility:hidden means the tag is not visible, but space is allocated for it on the page.

display:none means completely hides elements with its space. (although you can still interact with it through the DOM)

How to retrieve a recursive directory and file list from PowerShell excluding some files and folders?

Commenting here as this seems to be the most popular answer on the subject for searching for files whilst excluding certain directories in powershell.

To avoid issues with post filtering of results (i.e. avoiding permission issues etc), I only needed to filter out top level directories and that is all this example is based on, so whilst this example doesn't filter child directory names, it could very easily be made recursive to support this, if you were so inclined.

Quick breakdown of how the snippet works

$folders << Uses Get-Childitem to query the file system and perform folder exclusion

$file << The pattern of the file I am looking for

foreach << Iterates the $folders variable performing a recursive search using the Get-Childitem command

$folders = Get-ChildItem -Path C:\ -Directory -Name -Exclude Folder1,"Folder 2"
$file = "*filenametosearchfor*.extension"

foreach ($folder in $folders) {
   Get-Childitem -Path "C:/$folder" -Recurse -Filter $file | ForEach-Object { Write-Output $_.FullName }
}

How to use XPath contains() here?

 
//ul[@class="featureList" and li//text()[contains(., "Model")]]

NVIDIA-SMI has failed because it couldn't communicate with the NVIDIA driver

My system version: ubuntu 20.04 LTS.

  • I solved this by generate a new MOK and enroll it into shim.

  • Without disable of Secure Boot, although it also really works for me.

  • Simply execute this command and follow what it suggests:

    sudo update-secureboot-policy --enroll-key

According to ubuntu's wiki: How can I do non-automated signing of drivers

How to upload a file in Django?

Phew, Django documentation really does not have good example about this. I spent over 2 hours to dig up all the pieces to understand how this works. With that knowledge I implemented a project that makes possible to upload files and show them as list. To download source for the project, visit https://github.com/axelpale/minimal-django-file-upload-example or clone it:

> git clone https://github.com/axelpale/minimal-django-file-upload-example.git

Update 2013-01-30: The source at GitHub has also implementation for Django 1.4 in addition to 1.3. Even though there is few changes the following tutorial is also useful for 1.4.

Update 2013-05-10: Implementation for Django 1.5 at GitHub. Minor changes in redirection in urls.py and usage of url template tag in list.html. Thanks to hubert3 for the effort.

Update 2013-12-07: Django 1.6 supported at GitHub. One import changed in myapp/urls.py. Thanks goes to Arthedian.

Update 2015-03-17: Django 1.7 supported at GitHub, thanks to aronysidoro.

Update 2015-09-04: Django 1.8 supported at GitHub, thanks to nerogit.

Update 2016-07-03: Django 1.9 supported at GitHub, thanks to daavve and nerogit

Project tree

A basic Django 1.3 project with single app and media/ directory for uploads. 

minimal-django-file-upload-example/
    src/
        myproject/
            database/
                sqlite.db
            media/
            myapp/
                templates/
                    myapp/
                        list.html
                forms.py
                models.py
                urls.py
                views.py
            __init__.py
            manage.py
            settings.py
            urls.py

1. Settings: myproject/settings.py

To upload and serve files, you need to specify where Django stores uploaded files and from what URL Django serves them. MEDIA_ROOT and MEDIA_URL are in settings.py by default but they are empty. See the first lines in Django Managing Files for details. Remember also set the database and add myapp to INSTALLED_APPS

...
import os

BASE_DIR = os.path.dirname(os.path.dirname(__file__))
...
DATABASES = {
    'default': {
        'ENGINE': 'django.db.backends.sqlite3',
        'NAME': os.path.join(BASE_DIR, 'database.sqlite3'),
        'USER': '',
        'PASSWORD': '',
        'HOST': '',
        'PORT': '',
    }
}
...
MEDIA_ROOT = os.path.join(BASE_DIR, 'media')
MEDIA_URL = '/media/'
...
INSTALLED_APPS = (
    ...
    'myapp',
)

2. Model: myproject/myapp/models.py

Next you need a model with a FileField. This particular field stores files e.g. to media/documents/2011/12/24/ based on current date and MEDIA_ROOT. See FileField reference.

# -*- coding: utf-8 -*-
from django.db import models

class Document(models.Model):
    docfile = models.FileField(upload_to='documents/%Y/%m/%d')

3. Form: myproject/myapp/forms.py

To handle upload nicely, you need a form. This form has only one field but that is enough. See Form FileField reference for details.

# -*- coding: utf-8 -*-
from django import forms

class DocumentForm(forms.Form):
    docfile = forms.FileField(
        label='Select a file',
        help_text='max. 42 megabytes'
    )

4. View: myproject/myapp/views.py

A view where all the magic happens. Pay attention how request.FILES are handled. For me, it was really hard to spot the fact that request.FILES['docfile'] can be saved to models.FileField just like that. The model's save() handles the storing of the file to the filesystem automatically.

# -*- coding: utf-8 -*-
from django.shortcuts import render_to_response
from django.template import RequestContext
from django.http import HttpResponseRedirect
from django.core.urlresolvers import reverse

from myproject.myapp.models import Document
from myproject.myapp.forms import DocumentForm

def list(request):
    # Handle file upload
    if request.method == 'POST':
        form = DocumentForm(request.POST, request.FILES)
        if form.is_valid():
            newdoc = Document(docfile = request.FILES['docfile'])
            newdoc.save()

            # Redirect to the document list after POST
            return HttpResponseRedirect(reverse('myapp.views.list'))
    else:
        form = DocumentForm() # A empty, unbound form

    # Load documents for the list page
    documents = Document.objects.all()

    # Render list page with the documents and the form
    return render_to_response(
        'myapp/list.html',
        {'documents': documents, 'form': form},
        context_instance=RequestContext(request)
    )

5. Project URLs: myproject/urls.py

Django does not serve MEDIA_ROOT by default. That would be dangerous in production environment. But in development stage, we could cut short. Pay attention to the last line. That line enables Django to serve files from MEDIA_URL. This works only in developement stage.

See django.conf.urls.static.static reference for details. See also this discussion about serving media files.

# -*- coding: utf-8 -*-
from django.conf.urls import patterns, include, url
from django.conf import settings
from django.conf.urls.static import static

urlpatterns = patterns('',
    (r'^', include('myapp.urls')),
) + static(settings.MEDIA_URL, document_root=settings.MEDIA_ROOT)

6. App URLs: myproject/myapp/urls.py

To make the view accessible, you must specify urls for it. Nothing special here.

# -*- coding: utf-8 -*-
from django.conf.urls import patterns, url

urlpatterns = patterns('myapp.views',
    url(r'^list/$', 'list', name='list'),
)

7. Template: myproject/myapp/templates/myapp/list.html

The last part: template for the list and the upload form below it. The form must have enctype-attribute set to "multipart/form-data" and method set to "post" to make upload to Django possible. See File Uploads documentation for details.

The FileField has many attributes that can be used in templates. E.g. {{ document.docfile.url }} and {{ document.docfile.name }} as in the template. See more about these in Using files in models article and The File object documentation.

<!DOCTYPE html>
<html>
    <head>
        <meta charset="utf-8">
        <title>Minimal Django File Upload Example</title>   
    </head>
    <body>
    <!-- List of uploaded documents -->
    {% if documents %}
        <ul>
        {% for document in documents %}
            <li><a href="{{ document.docfile.url }}">{{ document.docfile.name }}</a></li>
        {% endfor %}
        </ul>
    {% else %}
        <p>No documents.</p>
    {% endif %}

        <!-- Upload form. Note enctype attribute! -->
        <form action="{% url 'list' %}" method="post" enctype="multipart/form-data">
            {% csrf_token %}
            <p>{{ form.non_field_errors }}</p>
            <p>{{ form.docfile.label_tag }} {{ form.docfile.help_text }}</p>
            <p>
                {{ form.docfile.errors }}
                {{ form.docfile }}
            </p>
            <p><input type="submit" value="Upload" /></p>
        </form>
    </body>
</html>

8. Initialize

Just run syncdb and runserver.

> cd myproject
> python manage.py syncdb
> python manage.py runserver

Results

Finally, everything is ready. On default Django developement environment the list of uploaded documents can be seen at localhost:8000/list/. Today the files are uploaded to /path/to/myproject/media/documents/2011/12/17/ and can be opened from the list.

I hope this answer will help someone as much as it would have helped me.

Selenium WebDriver and DropDown Boxes

 
select = driver.FindElement(By.CssSelector("select[uniq id']"));
                selectElement = new SelectElement(select);
                var optionList =
                    driver.FindElements(By.CssSelector("select[uniq id']>option"));
                selectElement.SelectByText(optionList[GenerateRandomNumber(1, optionList.Count())].Text);

Favicon not showing up in Google Chrome

I read a bunch of different entries till I finally found a solution that worked for my scenario (ASP.NET MVC4 project).

Instead of using the filename favicon.ico for my icon, I renamed it to something else, ie myIcon.ico. Then I just used exactly what Domi posted:

<link rel="shortcut icon" href="myIcon.ico" type="image/x-icon" />

And this worked!

It's not a caching issue because I tested this with Fiddler - a request for favicon never occurred, even if I cleared my cache "From the beginning of time". I believe it's just some odd bug with chrome?

Plotting histograms from grouped data in a pandas DataFrame

I'm on a roll, just found an even simpler way to do it using the by keyword in the hist method:

df['N'].hist(by=df['Letter'])

That's a very handy little shortcut for quickly scanning your grouped data!

For future visitors, the product of this call is the following chart: enter image description here

Sublime Text 3, convert spaces to tabs

As you might already know, you can customize your indention settings in Preferences.sublime-settings, for example:

"detect_indentation": true,
"tab_size": 4,
"translate_tabs_to_spaces": false

This will set your editor to use tabs that are 4 spaces wide and will override the default behavior that causes Sublime to match the indention of whatever file you're editing. With these settings, re-indenting the file will cause any spaces to be replaced with tabs.

As far as automatically re-indenting when opening a file, that's not quite as easy (but probably isn't a great idea since whitespace changes wreak havoc on file diffs). What might be a better course of action: you can map a shortcut for re-indention and just trigger that when you open a new file that needs fixing.

How to see which flags -march=native will activate?

It should be (-### is similar to -v):

echo | gcc -### -E - -march=native

To show the "real" native flags for gcc.

You can make them appear more "clearly" with a command:

gcc -### -E - -march=native 2>&1 | sed -r '/cc1/!d;s/(")|(^.* - )//g'

and you can get rid of flags with -mno-* with:

gcc -### -E - -march=native 2>&1 | sed -r '/cc1/!d;s/(")|(^.* - )|( -mno-[^\ ]+)//g'

Java program to connect to Sql Server and running the sample query From Eclipse

Refer the below link.

There are two important changes that you should make

driver name as "com.microsoft.sqlserver.jdbc.SQLServerDriver"

& in URL "jdbc:sqlserver://localhost:1433"+";databaseName=AdventureWorks2008R2"

http://www.programcreek.com/2010/05/java-code-for-connecting-ms-sql-server-by-using-sql-server-authentication/

Sql Query to list all views in an SQL Server 2005 database

To finish the set off (with what has already been suggested):

SELECT * FROM sys.views

This gives extra properties on each view, not available from sys.objects (which contains properties common to all types of object) or INFORMATION_SCHEMA.VIEWS. Though INFORMATION_SCHEMA approach does provide the view definition out-of-the-box.

Loop through Map in Groovy?

Quite simple with a closure:

def map = [
           'iPhone':'iWebOS',
           'Android':'2.3.3',
           'Nokia':'Symbian',
           'Windows':'WM8'
           ]

map.each{ k, v -> println "${k}:${v}" }

How do I solve this error, "error while trying to deserialize parameter"

Make sure that the table you are returning has a schema. If not, then create a default schema (i.e. add a column in that table).

REST API error return good practices

Don't forget the 5xx errors as well for application errors.

In this case what about 409 (Conflict)? This assumes that the user can fix the problem by deleting stored resources.

Otherwise 507 (not entirely standard) may also work. I wouldn't use 200 unless you use 200 for errors in general.

How do I make an asynchronous GET request in PHP?

You don't. While PHP offers lots of ways to call a URL, it doesn't offer out of the box support for doing any kind of asynchronous/threaded processing per request/execution cycle. Any method of sending a request for a URL (or a SQL statement, or a etc.) is going to wait for some kind of response. You'll need some kind of secondary system running on the local machine to achieve this (google around for "php job queue")

How can I make the Android emulator show the soft keyboard?

To be more precise, with Lollipop these are the steps I followed to show soft keyboard:

  1. Settings > Language & Input;
  2. under "Keyboard & input methods" label, select "Current Keyboard";
  3. A Dialog named "Change Keyboard" appears, switch ON "Hardware", then select "Choose keyboards";
  4. another Dialog appears, switch ON the "Sample Soft Keyboard". Here you get an alert about the possibility that keyboard will store everything you write, also passwords. Give OK;
  5. Repeat above steps in order to show "Change Keyboard" Dialog again, here the new option "Sample Soft Keyboard" is available and you can select it.

NOTE: after that, you might experience problems in running you app (as I had). Simply restart the emulator.

How to remove a Gitlab project?

Click on Project settings which you want to delete-->General project settings-->Expand-->Advanced settings-->Remove project.

Java ByteBuffer to String

 
private String convertFrom(String lines, String from, String to) {
    ByteBuffer bb = ByteBuffer.wrap(lines.getBytes());
    CharBuffer cb = Charset.forName(to).decode(bb);
    return new String(Charset.forName(from).encode(cb).array());
};
public Doit(){
    String concatenatedLines = convertFrom(concatenatedLines, "CP1252", "UTF-8");
};

Maintain the aspect ratio of a div with CSS

lets say you have 2 divs the outher div is a container and the inner could be any element that you need to keep its ratio (img or an youtube iframe or whatever )

html looks like this :

<div class='container'>
  <div class='element'>
  </div><!-- end of element -->
<div><!-- end of container -->

lets say you need to keep the ratio of the "element" ratio => 4 to 1 or 2 to 1 ...

css looks like this

.container{
  position: relative;
  height: 0
  padding-bottom : 75% /* for 4 to 3 ratio */ 25% /* for 4 to 1 ratio ..*/
  
}

.element{
  width : 100%;
  height: 100%;
  position: absolute; 
  top : 0 ;
  bottom : 0 ;
  background : red; /* just for illustration */
}

padding when specified in % it is calculated based on width not height. .. so basically you it doesn't matter what your width it height will always be calculated based of that . which will keep the ratio .

How to get DateTime.Now() in YYYY-MM-DDThh:mm:ssTZD format using C#

use zzz instead of TZD

Example:

DateTime.Now.ToString("yyyy-MM-ddThh:mm:sszzz");

Response:

2011-08-09T11:50:00:02+02:00

UITableView with fixed section headers

The headers only remain fixed when the UITableViewStyle property of the table is set to UITableViewStylePlain. If you have it set to UITableViewStyleGrouped, the headers will scroll up with the cells.

Determine Whether Two Date Ranges Overlap

All the solutions that check a multitude of conditions based on where the ranges are in relation to one another can be greatly simplified by just ensuring that a specific range starts earlier! You ensure that the first range starts earlier (or at the same time) by swapping the ranges if necessary up front.

Then, you can detect overlap if the other range start is less than or equal to the first range end (if ranges are inclusive, containing both the start and end times) or less than (if ranges are inclusive of start and exclusive of end).

Assuming inclusive at both ends, there's only four possibilities of which one is a non-overlap:

|----------------------|        range 1
|--->                           range 2 overlap
 |--->                          range 2 overlap
                       |--->    range 2 overlap
                        |--->   range 2 no overlap

The endpoint of the range 2 doesn't enter into it. So, in pseudo-code:

def doesOverlap (r1, r2):
    if r1.s > r2.s:
        swap r1, r2
    if r2.s > r1.e:
        return false
    return true

This could be simplified even more into:

def doesOverlap (r1, r2):
    if r1.s > r2.s:
        swap r1, r2
    return r2.s <= r1.e

If the ranges are inclusive at the start and exclusive at the end, you just have to replace > with >= in the second if statement (for the first code segment: in the second code segment, you'd use < rather than <=):

|----------------------|        range 1
|--->                           range 2 overlap
 |--->                          range 2 overlap
                       |--->    range 2 no overlap
                        |--->   range 2 no overlap

You greatly limit the number of checks you have to make because you remove half of the problem space early by ensuring range 1 never starts after range 2.

How to read a file in reverse order?

Thanks for the answer @srohde. It has a small bug checking for newline character with 'is' operator, and I could not comment on the answer with 1 reputation. Also I'd like to manage file open outside because that enables me to embed my ramblings for luigi tasks.

What I needed to change has the form:

with open(filename) as fp:
    for line in fp:
        #print line,  # contains new line
        print '>{}<'.format(line)

I'd love to change to:

with open(filename) as fp:
    for line in reversed_fp_iter(fp, 4):
        #print line,  # contains new line
        print '>{}<'.format(line)

Here is a modified answer that wants a file handle and keeps newlines:

def reversed_fp_iter(fp, buf_size=8192):
    """a generator that returns the lines of a file in reverse order
    ref: https://stackoverflow.com/a/23646049/8776239
    """
    segment = None  # holds possible incomplete segment at the beginning of the buffer
    offset = 0
    fp.seek(0, os.SEEK_END)
    file_size = remaining_size = fp.tell()
    while remaining_size > 0:
        offset = min(file_size, offset + buf_size)
        fp.seek(file_size - offset)
        buffer = fp.read(min(remaining_size, buf_size))
        remaining_size -= buf_size
        lines = buffer.splitlines(True)
        # the first line of the buffer is probably not a complete line so
        # we'll save it and append it to the last line of the next buffer
        # we read
        if segment is not None:
            # if the previous chunk starts right from the beginning of line
            # do not concat the segment to the last line of new chunk
            # instead, yield the segment first
            if buffer[-1] == '\n':
                #print 'buffer ends with newline'
                yield segment
            else:
                lines[-1] += segment
                #print 'enlarged last line to >{}<, len {}'.format(lines[-1], len(lines))
        segment = lines[0]
        for index in range(len(lines) - 1, 0, -1):
            if len(lines[index]):
                yield lines[index]
    # Don't yield None if the file was empty
    if segment is not None:
        yield segment

A select query selecting a select statement

I was over-complicating myself. After taking a long break and coming back, the desired output could be accomplished by this simple query:

SELECT Sandwiches.[Sandwich Type], Sandwich.Bread, Count(Sandwiches.[SandwichID]) AS [Total Sandwiches]
FROM Sandwiches
GROUP BY Sandwiches.[Sandwiches Type], Sandwiches.Bread;

Thanks for answering, it helped my train of thought.

How do I set cell value to Date and apply default Excel date format?

This example is for working with .xlsx file types. This example comes from a .jsp page used to create a .xslx spreadsheet.

import org.apache.poi.xssf.usermodel.*; //import needed

XSSFWorkbook  wb = new XSSFWorkbook ();  // Create workbook
XSSFSheet sheet = wb.createSheet();      // Create spreadsheet in workbook
XSSFRow row = sheet.createRow(rowIndex); // Create the row in the spreadsheet


//1. Create the date cell style
XSSFCreationHelper createHelper = wb.getCreationHelper();
XSSFCellStyle cellStyle         = wb.createCellStyle();
cellStyle.setDataFormat(
createHelper.createDataFormat().getFormat("MMMM dd, yyyy")); 

//2. Apply the Date cell style to a cell

//This example sets the first cell in the row using the date cell style
cell = row.createCell(0);
cell.setCellValue(new Date());
cell.setCellStyle(cellStyle);

How to create a inner border for a box in html?

Please have a look 

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
    <html xmlns="http://www.w3.org/1999/xhtml">
    <head>
    <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
    <title>Untitled Document</title>
    <style>
    .box{ width:500px; height:200px; background:#000; border:2px solid #ccc;}
        .inner-border {
            border: 20px solid black;
            box-shadow: inset 0px 0px 0px 10px red;
            box-sizing: border-box; /* Include padding and border in element's width and height */
        }
        /* CSS3 solution only for rectangular shape */
        .inner-outline {
            outline: 10px solid red;
            outline-offset: -30px;
        }
    </style>
    </head>

    <body>
    <div class="box inner-border inner-outline"></div>
    </body>
    </html>

In Angular, how to add Validator to FormControl after control is created?

You simply pass the FormControl an array of validators.

Here's an example showing how you can add validators to an existing FormControl:

this.form.controls["firstName"].setValidators([Validators.minLength(1), Validators.maxLength(30)]);

Note, this will reset any existing validators you added when you created the FormControl.

Multiple simultaneous downloads using Wget?

As other posters have mentioned, I'd suggest you have a look at aria2. From the Ubuntu man page for version 1.16.1:

aria2 is a utility for downloading files. The supported protocols are HTTP(S), FTP, BitTorrent, and Metalink. aria2 can download a file from multiple sources/protocols and tries to utilize your maximum download bandwidth. It supports downloading a file from HTTP(S)/FTP and BitTorrent at the same time, while the data downloaded from HTTP(S)/FTP is uploaded to the BitTorrent swarm. Using Metalink's chunk checksums, aria2 automatically validates chunks of data while downloading a file like BitTorrent.

You can use the -x flag to specify the maximum number of connections per server (default: 1):

aria2c -x 16 [url]

If the same file is available from multiple locations, you can choose to download from all of them. Use the -j flag to specify the maximum number of parallel downloads for every static URI (default: 5).

aria2c -j 5 [url] [url2]

Have a look at http://aria2.sourceforge.net/ for more information. For usage information, the man page is really descriptive and has a section on the bottom with usage examples. An online version can be found at http://aria2.sourceforge.net/manual/en/html/README.html.

How to annotate MYSQL autoincrement field with JPA annotations

can you check whether you connected to the correct database. as i was faced same issue, but finally i found that i connected to different database.

identity supports identity columns in DB2, MySQL, MS SQL Server, Sybase and HypersonicSQL. The returned identifier is of type long, short or int.

More Info : http://docs.jboss.org/hibernate/orm/3.5/reference/en/html/mapping.html#mapping-declaration-id

How to fix 'Microsoft Excel cannot open or save any more documents'

Go to this key on Registry Editor (Run | Regedit) HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\User Shell Folders

change key Cache to something like C:\Windows\Temp

My similar problem was solved like this.

Regards,

Ripley

libaio.so.1: cannot open shared object file

Install the packages:

sudo apt-get install libaio1 libaio-dev

or

sudo yum install libaio

How to save to local storage using Flutter?

You can use Localstorage

1- Add dependency to pubspec.yaml (Change the version based on the last)

dependencies:
  ...
  localstorage: ^3.0.0

2- Then run the following command

flutter packages get

3- import the localstorage :

import 'package:localstorage/localstorage.dart';

4- create an instance

class MainApp extends StatelessWidget {
  final LocalStorage storage = new LocalStorage('localstorage_app');
  ...
}

Add item to lcoalstorage :

void addItemsToLocalStorage() {
  storage.setItem('name', 'Abolfazl');
  storage.setItem('family', 'Roshanzamir');

  final info = json.encode({'name': 'Darush', 'family': 'Roshanzami'});
  storage.setItem('info', info);
}

Get an item from lcoalstorage:

void getitemFromLocalStorage() {
  final name = storage.getItem('name'); // Abolfazl
  final family = storage.getItem('family'); // Roshanzamir
  
  Map<String, dynamic> info = json.decode(storage.getItem('info'));
  final info_name=info['name'];
  final info_family=info['family'];
}

Delete an item from localstorage :

void removeItemFromLocalStorage() {
  storage.deleteItem('name');
  storage.deleteItem('family');
  storage.deleteItem('info');
}

How to do a SOAP Web Service call from Java class?

I understand your problem boils down to how to call a SOAP (JAX-WS) web service from Java and get its returning object. In that case, you have two possible approaches:

  1. Generate the Java classes through wsimport and use them; or
  2. Create a SOAP client that:
    1. Serializes the service's parameters to XML;
    2. Calls the web method through HTTP manipulation; and
    3. Parse the returning XML response back into an object.


About the first approach (using wsimport):

I see you already have the services' (entities or other) business classes, and it's a fact that the wsimport generates a whole new set of classes (that are somehow duplicates of the classes you already have).

I'm afraid, though, in this scenario, you can only either:

  • Adapt (edit) the wsimport generated code to make it use your business classes (this is difficult and somehow not worth it - bear in mind everytime the WSDL changes, you'll have to regenerate and readapt the code); or
  • Give up and use the wsimport generated classes. (In this solution, you business code could "use" the generated classes as a service from another architectural layer.)

About the second approach (create your custom SOAP client):

In order to implement the second approach, you'll have to:

  1. Make the call:
    • Use the SAAJ (SOAP with Attachments API for Java) framework (see below, it's shipped with Java SE 1.6 or above) to make the calls; or
    • You can also do it through java.net.HttpUrlconnection (and some java.io handling).
  2. Turn the objects into and back from XML:
    • Use an OXM (Object to XML Mapping) framework such as JAXB to serialize/deserialize the XML from/into objects
    • Or, if you must, manually create/parse the XML (this can be the best solution if the received object is only a little bit differente from the sent one).

Creating a SOAP client using classic java.net.HttpUrlConnection is not that hard (but not that simple either), and you can find in this link a very good starting code.

I recommend you use the SAAJ framework:

SOAP with Attachments API for Java (SAAJ) is mainly used for dealing directly with SOAP Request/Response messages which happens behind the scenes in any Web Service API. It allows the developers to directly send and receive soap messages instead of using JAX-WS.

See below a working example (run it!) of a SOAP web service call using SAAJ. It calls this web service.

import javax.xml.soap.*;

public class SOAPClientSAAJ {

    // SAAJ - SOAP Client Testing
    public static void main(String args[]) {
        /*
            The example below requests from the Web Service at:
             https://www.w3schools.com/xml/tempconvert.asmx?op=CelsiusToFahrenheit


            To call other WS, change the parameters below, which are:
             - the SOAP Endpoint URL (that is, where the service is responding from)
             - the SOAP Action

            Also change the contents of the method createSoapEnvelope() in this class. It constructs
             the inner part of the SOAP envelope that is actually sent.
         */
        String soapEndpointUrl = "https://www.w3schools.com/xml/tempconvert.asmx";
        String soapAction = "https://www.w3schools.com/xml/CelsiusToFahrenheit";

        callSoapWebService(soapEndpointUrl, soapAction);
    }

    private static void createSoapEnvelope(SOAPMessage soapMessage) throws SOAPException {
        SOAPPart soapPart = soapMessage.getSOAPPart();

        String myNamespace = "myNamespace";
        String myNamespaceURI = "https://www.w3schools.com/xml/";

        // SOAP Envelope
        SOAPEnvelope envelope = soapPart.getEnvelope();
        envelope.addNamespaceDeclaration(myNamespace, myNamespaceURI);

            /*
            Constructed SOAP Request Message:
            <SOAP-ENV:Envelope xmlns:SOAP-ENV="http://schemas.xmlsoap.org/soap/envelope/" xmlns:myNamespace="https://www.w3schools.com/xml/">
                <SOAP-ENV:Header/>
                <SOAP-ENV:Body>
                    <myNamespace:CelsiusToFahrenheit>
                        <myNamespace:Celsius>100</myNamespace:Celsius>
                    </myNamespace:CelsiusToFahrenheit>
                </SOAP-ENV:Body>
            </SOAP-ENV:Envelope>
            */

        // SOAP Body
        SOAPBody soapBody = envelope.getBody();
        SOAPElement soapBodyElem = soapBody.addChildElement("CelsiusToFahrenheit", myNamespace);
        SOAPElement soapBodyElem1 = soapBodyElem.addChildElement("Celsius", myNamespace);
        soapBodyElem1.addTextNode("100");
    }

    private static void callSoapWebService(String soapEndpointUrl, String soapAction) {
        try {
            // Create SOAP Connection
            SOAPConnectionFactory soapConnectionFactory = SOAPConnectionFactory.newInstance();
            SOAPConnection soapConnection = soapConnectionFactory.createConnection();

            // Send SOAP Message to SOAP Server
            SOAPMessage soapResponse = soapConnection.call(createSOAPRequest(soapAction), soapEndpointUrl);

            // Print the SOAP Response
            System.out.println("Response SOAP Message:");
            soapResponse.writeTo(System.out);
            System.out.println();

            soapConnection.close();
        } catch (Exception e) {
            System.err.println("\nError occurred while sending SOAP Request to Server!\nMake sure you have the correct endpoint URL and SOAPAction!\n");
            e.printStackTrace();
        }
    }

    private static SOAPMessage createSOAPRequest(String soapAction) throws Exception {
        MessageFactory messageFactory = MessageFactory.newInstance();
        SOAPMessage soapMessage = messageFactory.createMessage();

        createSoapEnvelope(soapMessage);

        MimeHeaders headers = soapMessage.getMimeHeaders();
        headers.addHeader("SOAPAction", soapAction);

        soapMessage.saveChanges();

        /* Print the request message, just for debugging purposes */
        System.out.println("Request SOAP Message:");
        soapMessage.writeTo(System.out);
        System.out.println("\n");

        return soapMessage;
    }

}

About using JAXB for serializing/deserializing, it is very easy to find information about it. You can start here: http://www.mkyong.com/java/jaxb-hello-world-example/.

Open Facebook Page in Facebook App (if installed) on Android

Okay I modifed @AndroidMechanics Code, because on devices were facebook is disabled the app crashes!

here is the modifed getFacebookUrl:

public String getFacebookPageURL(Context context) {
        PackageManager packageManager = context.getPackageManager();
        try {
            int versionCode = packageManager.getPackageInfo("com.facebook.katana", 0).versionCode;

            boolean activated =  packageManager.getApplicationInfo("com.facebook.katana", 0).enabled;
            if(activated){
                if ((versionCode >= 3002850)) { 
                    return "fb://facewebmodal/f?href=" + FACEBOOK_URL;
                } else { 
                    return "fb://page/" + FACEBOOK_PAGE_ID;
                }
            }else{
                return FACEBOOK_URL;
            }
         } catch (PackageManager.NameNotFoundException e) {
            return FACEBOOK_URL; 
        }
    }

The only added thing is to look if the app is disabled or not if it is disabled the app will call the webbrowser!

Merging two CSV files using Python

When I'm working with csv files, I often use the pandas library. It makes things like this very easy. For example:

import pandas as pd

a = pd.read_csv("filea.csv")
b = pd.read_csv("fileb.csv")
b = b.dropna(axis=1)
merged = a.merge(b, on='title')
merged.to_csv("output.csv", index=False)

Some explanation follows. First, we read in the csv files:

>>> a = pd.read_csv("filea.csv")
>>> b = pd.read_csv("fileb.csv")
>>> a
   title  stage    jan    feb
0   darn  3.001  0.421  0.532
1     ok  2.829  1.036  0.751
2  three  1.115  1.146  2.921
>>> b
   title    mar    apr    may       jun  Unnamed: 5
0   darn  0.631  1.321  0.951    1.7510         NaN
1     ok  1.001  0.247  2.456    0.3216         NaN
2  three  0.285  1.283  0.924  956.0000         NaN

and we see there's an extra column of data (note that the first line of fileb.csv -- title,mar,apr,may,jun, -- has an extra comma at the end). We can get rid of that easily enough:

>>> b = b.dropna(axis=1)
>>> b
   title    mar    apr    may       jun
0   darn  0.631  1.321  0.951    1.7510
1     ok  1.001  0.247  2.456    0.3216
2  three  0.285  1.283  0.924  956.0000

Now we can merge a and b on the title column:

>>> merged = a.merge(b, on='title')
>>> merged
   title  stage    jan    feb    mar    apr    may       jun
0   darn  3.001  0.421  0.532  0.631  1.321  0.951    1.7510
1     ok  2.829  1.036  0.751  1.001  0.247  2.456    0.3216
2  three  1.115  1.146  2.921  0.285  1.283  0.924  956.0000

and finally write this out:

>>> merged.to_csv("output.csv", index=False)

producing:

title,stage,jan,feb,mar,apr,may,jun
darn,3.001,0.421,0.532,0.631,1.321,0.951,1.751
ok,2.829,1.036,0.751,1.001,0.247,2.456,0.3216
three,1.115,1.146,2.921,0.285,1.283,0.924,956.0

MySQL Query to select data from last week?

 
WHERE yourDateColumn > DATEADD(DAY, -7, GETDATE()) ;

Proper use of errors

Simple solution to emit and show message by Exception.

try {
  throw new TypeError("Error message");
}
catch (e){
  console.log((<Error>e).message);//conversion to Error type
}

Caution

Above is not a solution if we don't know what kind of error can be emitted from the block. In such cases type guards should be used and proper handling for proper error should be done - take a look on @Moriarty answer.

Update date + one year in mysql

You could use DATE_ADD : (or ADDDATE with INTERVAL)

UPDATE table SET date = DATE_ADD(date, INTERVAL 1 YEAR)

Check existence of directory and create if doesn't exist

I had an issue with R 2.15.3 whereby while trying to create a tree structure recursively on a shared network drive I would get a permission error.

To get around this oddity I manually create the structure;

mkdirs <- function(fp) {
    if(!file.exists(fp)) {
        mkdirs(dirname(fp))
        dir.create(fp)
    }
} 

mkdirs("H:/foo/bar")

excel VBA run macro automatically whenever a cell is changed

In an attempt to spot a change somewhere in a particular column (here in "W", i.e. "23"), I modified Peter Alberts' answer to:

Private Sub Worksheet_Change(ByVal Target As Range)
    If Not Target.Column = 23 Then Exit Sub
    Application.EnableEvents = False             'to prevent endless loop
    On Error GoTo Finalize                       'to re-enable the events
    MsgBox "You changed a cell in column W, row " & Target.Row
    MsgBox "You changed it to: " & Target.Value
Finalize:
    Application.EnableEvents = True
End Sub

ASP.NET Web API session or something?

in Global.asax add 

public override void Init()
{
    this.PostAuthenticateRequest += MvcApplication_PostAuthenticateRequest;
    base.Init();
}

void MvcApplication_PostAuthenticateRequest(object sender, EventArgs e)
{
    System.Web.HttpContext.Current.SetSessionStateBehavior(
        SessionStateBehavior.Required);
}

give it a shot ;)

selecting an entire row based on a variable excel vba

Saw this answer on another site and it works for me as well!

Posted by Shawn on October 14, 2001 1:24 PM

var1 = 1

var2 = 5

Rows(var1 & ":" & var2).Select

That worked for me, looks like you just have to keep the variables outside the quotes and add the and statement (&)

-Shawn

How to capture a backspace on the onkeydown event

not sure if it works outside of firefox:

callback (event){
  if (event.keyCode === event.DOM_VK_BACK_SPACE || event.keyCode === event.DOM_VK_DELETE)
    // do something
  }
}

if not, replace event.DOM_VK_BACK_SPACE with 8 and event.DOM_VK_DELETE with 46 or define them as constant (for better readability)

How to get the azure account tenant Id?

If you have installed Azure CLI 2.0 in your machine, you should be able to get the list of subscription that you belong to with the following command,

az login

if you want to see as a table output you could just use

az account get-access-token --query tenant --output tsv

or you could use the Rest API

https://docs.microsoft.com/en-us/rest/api/resources/tenants/list

400 vs 422 response to POST of data

Your case: HTTP 400 is the right status code for your case from REST perspective as its syntactically incorrect to send sales_tax instead of tax, though its a valid JSON. This is normally enforced by most of the server side frameworks when mapping the JSON to objects. However, there are some REST implementations that ignore new key in JSON object. In that case, a custom content-type specification to accept only valid fields can be enforced by server-side.

Ideal Scenario for 422:

In an ideal world, 422 is preferred and generally acceptable to send as response if the server understands the content type of the request entity and the syntax of the request entity is correct but was unable to process the data because its semantically erroneous.

Situations of 400 over 422:

Remember, the response code 422 is an extended HTTP (WebDAV) status code. There are still some HTTP clients / front-end libraries that aren't prepared to handle 422. For them, its as simple as "HTTP 422 is wrong, because it's not HTTP". From the service perspective, 400 isn't quite specific.

In enterprise architecture, the services are deployed mostly on service layers like SOA, IDM, etc. They typically serve multiple clients ranging from a very old native client to a latest HTTP clients. If one of the clients doesn't handle HTTP 422, the options are that asking the client to upgrade or change your response code to HTTP 400 for everyone. In my experience, this is very rare these days but still a possibility. So, a careful study of your architecture is always required before deciding on the HTTP response codes.

To handle situation like these, the service layers normally use versioning or setup configuration flag for strict HTTP conformance clients to send 400, and send 422 for the rest of them. That way they provide backwards compatibility support for existing consumers but at the same time provide the ability for the new clients to consume HTTP 422.

The latest update to RFC7321 says:

The 400 (Bad Request) status code indicates that the server cannot or
   will not process the request due to something that is perceived to be
   a client error (e.g., malformed request syntax, invalid request
   message framing, or deceptive request routing).

This confirms that servers can send HTTP 400 for invalid request. 400 doesn't refer only to syntax error anymore, however, 422 is still a genuine response provided the clients can handle it.

Capturing image from webcam in java?

JMyron is very simple for use. http://webcamxtra.sourceforge.net/

myron = new JMyron();
myron.start(imgw, imgh);
myron.update();
int[] img = myron.image();

Click a button with XPath containing partial id and title in Selenium IDE

Now that you have provided your HTML sample, we're able to see that your XPath is slightly wrong. While it's valid XPath, it's logically wrong.

You've got:

//*[contains(@id, 'ctl00_btnAircraftMapCell')]//*[contains(@title, 'Select Seat')]

Which translates into:

Get me all the elements that have an ID that contains ctl00_btnAircraftMapCell. Out of these elements, get any child elements that have a title that contains Select Seat.

What you actually want is:

//a[contains(@id, 'ctl00_btnAircraftMapCell') and contains(@title, 'Select Seat')]

Which translates into:

Get me all the anchor elements that have both: an id that contains ctl00_btnAircraftMapCell and a title that contains Select Seat.

JavaScript calculate the day of the year (1 - 366)

This works across Daylight Savings Time changes in all countries (the "noon" one above doesn't work in Australia):

Date.prototype.isLeapYear = function() {
    var year = this.getFullYear();
    if((year & 3) != 0) return false;
    return ((year % 100) != 0 || (year % 400) == 0);
};

// Get Day of Year
Date.prototype.getDOY = function() {
    var dayCount = [0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334];
    var mn = this.getMonth();
    var dn = this.getDate();
    var dayOfYear = dayCount[mn] + dn;
    if(mn > 1 && this.isLeapYear()) dayOfYear++;
    return dayOfYear;
};

Is it possible to hide/encode/encrypt php source code and let others have the system?

Yes, you can definitely hide/encode/encrypt the php source code and 'others' can install it on their machine. You could use the below tools to achieve the same.

But these 'others' can also decode/decrypt the source code using other tools and services found online. So you cannot 100% protect your code, what you can do is, make it tougher for someone to reverse engineer your code.

Most of these tools above support Encoding and Obfuscating.

  • Encoding will hide your code by encrypting it.
  • Obfuscating will make your code difficult to understand.

You can choose to use both (Encoding and Obfuscating) or either one, depending on your needs.

TABLOCK vs TABLOCKX

Quite an old article on mssqlcity attempts to explain the types of locks:

Shared locks are used for operations that do not change or update data, such as a SELECT statement.

Update locks are used when SQL Server intends to modify a page, and later promotes the update page lock to an exclusive page lock before actually making the changes.

Exclusive locks are used for the data modification operations, such as UPDATE, INSERT, or DELETE.

What it doesn't discuss are Intent (which basically is a modifier for these lock types). Intent (Shared/Exclusive) locks are locks held at a higher level than the real lock. So, for instance, if your transaction has an X lock on a row, it will also have an IX lock at the table level (which stops other transactions from attempting to obtain an incompatible lock at a higher level on the table (e.g. a schema modification lock) until your transaction completes or rolls back).

The concept of "sharing" a lock is quite straightforward - multiple transactions can have a Shared lock for the same resource, whereas only a single transaction may have an Exclusive lock, and an Exclusive lock precludes any transaction from obtaining or holding a Shared lock.

setup script exited with error: command 'x86_64-linux-gnu-gcc' failed with exit status 1

This was enough for me:

sudo apt-get install build-essential

nodejs - How to read and output jpg image?

Here is how you can read the entire file contents, and if done successfully, start a webserver which displays the JPG image in response to every request:

var http = require('http')
var fs = require('fs')

fs.readFile('image.jpg', function(err, data) {
  if (err) throw err // Fail if the file can't be read.
  http.createServer(function(req, res) {
    res.writeHead(200, {'Content-Type': 'image/jpeg'})
    res.end(data) // Send the file data to the browser.
  }).listen(8124)
  console.log('Server running at http://localhost:8124/')
})

Note that the server is launched by the "readFile" callback function and the response header has Content-Type: image/jpeg.

[Edit] You could even embed the image in an HTML page directly by using an <img> with a data URI source. For example:

  res.writeHead(200, {'Content-Type': 'text/html'});
  res.write('<html><body><img src="data:image/jpeg;base64,')
  res.write(Buffer.from(data).toString('base64'));
  res.end('"/></body></html>');

How do I get the current date in Cocoa

There is no difference in the location of the asterisk (at in C, which Obj-C is based on, it doesn't matter). It is purely preference (style).

How to import a csv file using python with headers intact, where first column is a non-numerical

Python's csv module handles data row-wise, which is the usual way of looking at such data. You seem to want a column-wise approach. Here's one way of doing it.

Assuming your file is named myclone.csv and contains

workers,constant,age
w0,7.334,-1.406
w1,5.235,-4.936
w2,3.2225,-1.478
w3,0,0

this code should give you an idea or two:

>>> import csv
>>> f = open('myclone.csv', 'rb')
>>> reader = csv.reader(f)
>>> headers = next(reader, None)
>>> headers
['workers', 'constant', 'age']
>>> column = {}
>>> for h in headers:
...    column[h] = []
...
>>> column
{'workers': [], 'constant': [], 'age': []}
>>> for row in reader:
...   for h, v in zip(headers, row):
...     column[h].append(v)
...
>>> column
{'workers': ['w0', 'w1', 'w2', 'w3'], 'constant': ['7.334', '5.235', '3.2225', '0'], 'age': ['-1.406', '-4.936', '-1.478', '0']}
>>> column['workers']
['w0', 'w1', 'w2', 'w3']
>>> column['constant']
['7.334', '5.235', '3.2225', '0']
>>> column['age']
['-1.406', '-4.936', '-1.478', '0']
>>>

To get your numeric values into floats, add this

converters = [str.strip] + [float] * (len(headers) - 1)

up front, and do this

for h, v, conv in zip(headers, row, converters):
  column[h].append(conv(v))

for each row instead of the similar two lines above.

How to split the filename from a full path in batch?

 
@echo off
Set filename="C:\Documents and Settings\All Users\Desktop\Dostips.cmd"
call :expand %filename%
:expand
set filename=%~nx1
echo The name of the file is %filename%
set folder=%~dp1
echo It's path is %folder%

Trim Whitespaces (New Line and Tab space) in a String in Oracle

Try the code below. It will work if you enter multiple lines in a single column.

create table  products (prod_id number , prod_desc varchar2(50));

insert into products values(1,'test first

test second

test third');

select replace(replace(prod_desc,chr(10),' '),chr(13),' ') from products  where prod_id=2;

Output :test first test second test third

String concatenation of two pandas columns

@DanielVelkov answer is the proper one BUT using string literals is faster:

# Daniel's
%timeit df.apply(lambda x:'%s is %s' % (x['bar'],x['foo']),axis=1)
## 963 µs ± 157 µs per loop (mean ± std. dev. of 7 runs, 1000 loops each)

# String literals - python 3
%timeit df.apply(lambda x: f"{x['bar']} is {x['foo']}", axis=1)
## 849 µs ± 4.28 µs per loop (mean ± std. dev. of 7 runs, 1000 loops each)

Select2 doesn't work when embedded in a bootstrap modal

I found a solution to this on github for select2

https://github.com/ivaynberg/select2/issues/1436

For bootstrap 3, the solution is:

$.fn.modal.Constructor.prototype.enforceFocus = function() {};

Bootstrap 4 renamed the enforceFocus method to _enforceFocus, so you'll need to patch that instead:

$.fn.modal.Constructor.prototype._enforceFocus = function() {};

Explanation copied from link above:

Bootstrap registers a listener to the focusin event which checks whether the focused element is either the overlay itself or a descendent of it - if not it just refocuses on the overlay. With the select2 dropdown being attached to the body this effectively prevents you from entering anything into the the textfield.

You can quickfix this by overwriting the enforceFocus function which registers the event on the modal

Cycles in an Undirected Graph

Here is a simple implementation in C++ of algorithm that checks if a graph has cycle(s) in O(n) time (n is number of vertexes in the Graph). I do not show here the Graph data structure implementation (to keep answer short). The algorithms expects the class Graph to have public methods, vector<int> getAdj(int v) that returns vertexes adjacent to the v and int getV() that returns total number of vertexes. Additionally, the algorithms assumes the vertexes of the Graph are numbered from 0 to n - 1.

class CheckCycleUndirectedGraph
{
private:
    bool cyclic;
    vector<bool> visited;

    void depthFirstSearch(const Graph& g, int v, int u) {
        visited[v] = true;
        for (auto w : g.getAdj(v)) {
            if (!visited[w]) {
                depthFirstSearch(g, w, v);
            }
            else if (w != u) {
                cyclic = true;
                return;
            }
        }
    }

public:
    CheckCycleUndirectedGraph(const Graph& g) : cyclic(false) {
        visited = vector<bool>(g.getV(), false);
        for (int v = 0; v < g.getV(); v++) {
            if (!visited[v]){
                depthFirstSearch(g, v, v);
                if(cyclic)
                  break;
            }
        }
    }

    bool containsCycle() const {
        return cyclic;
    }
};

Keep in mind that Graph may consist of several not connected components and there may be cycles inside of the components. The shown algorithms detects cycles in such graphs as well.

CSS to keep element at "fixed" position on screen

 
position: sticky;

The sticky element sticks on top of the page (top: 0) when you reach its scroll position.

See example: https://www.w3schools.com/css/tryit.asp?filename=trycss_position_sticky

Groovy executing shell commands

To add one more important information to above provided answers -

For a process

def proc = command.execute();

always try to use 

def outputStream = new StringBuffer();
proc.waitForProcessOutput(outputStream, System.err)
//proc.waitForProcessOutput(System.out, System.err)

rather than 

def output = proc.in.text;

to capture the outputs after executing commands in groovy as the latter is a blocking call (SO question for reason).

How to print last two columns using awk

 
awk '{print $NF-1, $NF}'  inputfile

Note: this works only if at least two columns exist. On records with one column you will get a spurious "-1 column1"

Launch an event when checking a checkbox in Angular2

Check Demo: https://stackblitz.com/edit/angular-6-checkbox?embed=1&file=src/app/app.component.html

  CheckBox: use change event to call the function and pass the event.

<label class="container">    
   <input type="checkbox" [(ngModel)]="theCheckbox"  data-md-icheck 
    (change)="toggleVisibility($event)"/>
      Checkbox is <span *ngIf="marked">checked</span><span 
     *ngIf="!marked">unchecked</span>
     <span class="checkmark"></span>
</label>
 <div>And <b>ngModel</b> also works, it's value is <b>{{theCheckbox}}</b></div>

Android button font size

Programmatically:

Button bt = new Button(this);
bt.setTextSize(12);

In xml:

<Button
    android:textSize="10sp"
/>

How to send only one UDP packet with netcat?

Netcat sends one packet per newline. So you're fine. If you do anything more complex then you might need something else.

I was fooling around with Wireshark when I realized this. Don't know if it helps.

Onclick CSS button effect

This is a press down button example I've made:

<div>
    <form id="forminput" action="action" method="POST">
       ...
    </form>
    <div style="right: 0px;bottom: 0px;position: fixed;" class="thumbnail">
        <div class="image">
            <a onclick="document.getElementById('forminput').submit();">
                <img src="images/button.png" alt="Some awesome text">
            </a>
        </div>
    </div>
</div>

the CSS file:

.thumbnail {
    width: 128px;
    height: 128px;
}

.image {
    width: 100%;
    height: 100%;    
}

.image img {
    -webkit-transition: all .25s ease; /* Safari and Chrome */
    -moz-transition: all .25s ease; /* Firefox */
    -ms-transition: all .25s ease; /* IE 9 */
    -o-transition: all .25s ease; /* Opera */
    transition: all .25s ease;
    max-width: 100%;
    max-height: 100%;
}

.image:hover img {
    -webkit-transform:scale(1.05); /* Safari and Chrome */
    -moz-transform:scale(1.05); /* Firefox */
    -ms-transform:scale(1.05); /* IE 9 */
    -o-transform:scale(1.05); /* Opera */
     transform:scale(1.05);
}

.image:active img {
    -webkit-transform:scale(.95); /* Safari and Chrome */
    -moz-transform:scale(.95); /* Firefox */
    -ms-transform:scale(.95); /* IE 9 */
    -o-transform:scale(.95); /* Opera */
     transform:scale(.95);
}

Enjoy it!

How do I clear the content of a div using JavaScript?

Just Javascript (as requested)

Add this function somewhere on your page (preferably in the <head>)

function clearBox(elementID)
{
    document.getElementById(elementID).innerHTML = "";
}

Then add the button on click event:

<button onclick="clearBox('cart_item')" />

In JQuery (for reference)

If you prefer JQuery you could do:

$("#cart_item").html("");

Error: No default engine was specified and no extension was provided

Error: No default engine was specified and no extension was provided

I got the same problem(for doing a mean stack project)..the problem is i didn't mentioned the formate to install npm i.e; pug or jade,ejs etc. so to solve this goto npm and enter express --view=pug foldername. This will load necessary pug files(index.pug,layout.pug etc..) in ur given folder .

Update multiple rows using select statement

None of above answers worked for me in MySQL, the following query worked though:

UPDATE
    Table1 t1
    JOIN
    Table2 t2 ON t1.ID=t2.ID 
SET
    t1.value =t2.value
WHERE
    ...

How to unzip files programmatically in Android?

This is my unzip method, which I use:

private boolean unpackZip(String path, String zipname)
{       
     InputStream is;
     ZipInputStream zis;
     try 
     {
         is = new FileInputStream(path + zipname);
         zis = new ZipInputStream(new BufferedInputStream(is));          
         ZipEntry ze;

         while((ze = zis.getNextEntry()) != null) 
         {
             ByteArrayOutputStream baos = new ByteArrayOutputStream();
             byte[] buffer = new byte[1024];
             int count;

             String filename = ze.getName();
             FileOutputStream fout = new FileOutputStream(path + filename);

             // reading and writing
             while((count = zis.read(buffer)) != -1) 
             {
                 baos.write(buffer, 0, count);
                 byte[] bytes = baos.toByteArray();
                 fout.write(bytes);             
                 baos.reset();
             }

             fout.close();               
             zis.closeEntry();
         }

         zis.close();
     } 
     catch(IOException e)
     {
         e.printStackTrace();
         return false;
     }

    return true;
}

Java ArrayList of Arrays?

 
ArrayList<String[]> action = new ArrayList<String[]>();

Don't need String[2];