Programs & Examples On #Eqatec

EQATEC is a software company headquartered in Copenhagen, Denmark. Its products - EQATEC Application Analytics and EQATEC Profiler - enable software development teams to improve decision-making based on real-time usage and application health data. Acquired by Telerik in March 2013.

INNER JOIN vs INNER JOIN (SELECT . FROM)

Seems to be identical just in case that SQL server will not try to read data which is not required for the query, the optimizer is clever enough

It can have sense when join on complex query (i.e which have joings, groupings etc itself) then, yes, it is better to specify required fields.

But there is one more point. If the query is simple there is no difference but EVERY extra action even which is supposed to improve performance makes optimizer works harder and optimizer can fail to get the best plan in time and will run not optimal query. So extras select can be a such action which can even decrease performance

What is the regex for "Any positive integer, excluding 0"

My pattern is complicated, but it covers exactly "Any positive integer, excluding 0" (1 - 2147483647, not long). It's for decimal numbers and doesn't allow leading zeros.

^((1?[1-9][0-9]{0,8})|20[0-9]{8}|(21[0-3][0-9]{7})|(214[0-6][0-9]{6})
|(2147[0-3][0-9]{5})|(21474[0-7][0-9]{4})|(214748[0-2][0-9]{3})
|(2147483[0-5][0-9]{2})|(21474836[0-3][0-9])|(214748364[0-7]))$

Should each and every table have a primary key?

In short, no. However, you need to keep in mind that certain client access CRUD operations require it. For future proofing, I tend to always utilize primary keys.

Figure out size of UILabel based on String in Swift

For multiline text this answer is not working correctly. You can build a different String extension by using UILabel

extension String {
func height(constraintedWidth width: CGFloat, font: UIFont) -> CGFloat {
    let label =  UILabel(frame: CGRect(x: 0, y: 0, width: width, height: .greatestFiniteMagnitude))
    label.numberOfLines = 0
    label.text = self
    label.font = font
    label.sizeToFit()

    return label.frame.height
 }
}

The UILabel gets a fixed width and the .numberOfLines is set to 0. By adding the text and calling .sizeToFit() it automatically adjusts to the correct height.

Code is written in Swift 3

HTML5 image icon to input placeholder

Adding to Tim's answer:

  #search:placeholder-shown {
     // show background image, I like svg 
     // when using svg, do not use HEX for colour; you can use rbg/a instead
     // also notice the single quotes
     background-image url('data:image/svg+xml; utf8, <svg>... <g fill="grey"...</svg>')
     // other background props
   }

   #search:not(:placeholder-shown) { background-image: none;}

How do I add items to an array in jQuery?

Hope this will help you..

var list = [];
    $(document).ready(function () {
        $('#test').click(function () {
            var oRows = $('#MainContent_Table1 tr').length;
            $('#MainContent_Table1 tr').each(function (index) {
                list.push(this.cells[0].innerHTML);
            });
        });
    });

Selecting the first "n" items with jQuery

You probably want to read up on slice. Your code will look something like this:

$("a").slice(0,20)

Apache won't follow symlinks (403 Forbidden)

I was having a similar problem that I could not resolve for a long time on my new server. In addition to palacsint's answer, a good question to ask is: are you using Apache 2.4? In Apache 2.4 there is a different mechanism for setting the permissions that do not work when done using the above configuration, so I used the solution explained in this blog post.

Basically, what I needed to do was convert my config file from:

Alias /demo /usr/demo/html

<Directory "/usr/demo/html">
    Options FollowSymLinks
    AllowOverride None
    Order allow,deny
    allow from all

</Directory>

to:

Alias /demo /usr/demo/html

<Directory "/usr/demo/html">
    Options FollowSymLinks
    AllowOverride None
    Require all granted
</Directory>

Note how the Order and allow lines have been replaced by Require all granted

Java Package Does Not Exist Error

You should add the following lines in your gradle build file (build.gradle)

dependencies { 
     compile files('/usr/share/stuff')
     ..
}

Why aren't python nested functions called closures?

def nested1(num1): 
    print "nested1 has",num1
    def nested2(num2):
        print "nested2 has",num2,"and it can reach to",num1
        return num1+num2    #num1 referenced for reading here
    return nested2

Gives:

In [17]: my_func=nested1(8)
nested1 has 8

In [21]: my_func(5)
nested2 has 5 and it can reach to 8
Out[21]: 13

This is an example of what a closure is and how it can be used.

How to change the font size on a matplotlib plot

Use plt.tick_params(labelsize=14)

python to arduino serial read & write

First you have to install a module call Serial. To do that go to the folder call Scripts which is located in python installed folder. If you are using Python 3 version it's normally located in location below,

C:\Python34\Scripts  

Once you open that folder right click on that folder with shift key. Then click on 'open command window here'. After that cmd will pop up. Write the below code in that cmd window,

pip install PySerial

and press enter.after that PySerial module will be installed. Remember to install the module u must have an INTERNET connection.


after successfully installed the module open python IDLE and write down the bellow code and run it.

import serial
# "COM11" is the port that your Arduino board is connected.set it to port that your are using        
ser = serial.Serial("COM11", 9600)
while True:
    cc=str(ser.readline())
    print(cc[2:][:-5])   

ajax jquery simple get request

You can make AJAX requests to applications loaded from the SAME domain and SAME port.

Besides that, you should add dataType JSON if you want the result to be deserialized automatically.

$.ajax({
        url: "https://app.asana.com/-/api/0.1/workspaces/",
        type: 'GET',
        dataType: 'json', // added data type
        success: function(res) {
            console.log(res);
            alert(res);
        }
    });

http://api.jquery.com/jQuery.ajax/

How to auto generate migrations with Sequelize CLI from Sequelize models?

You cannot create migration scripts for existing models.

Resources:

If going the classic way, you'll have to recreate the models via the CLI:

sequelize model:create --name MyUser --attributes first_name:string,last_name:string,bio:text

It will generate these files:

models/myuser.js:

_x000D_
_x000D_
"use strict";_x000D_
module.exports = function(sequelize, DataTypes) {_x000D_
  var MyUser = sequelize.define("MyUser", {_x000D_
    first_name: DataTypes.STRING,_x000D_
    last_name: DataTypes.STRING,_x000D_
    bio: DataTypes.TEXT_x000D_
  }, {_x000D_
    classMethods: {_x000D_
      associate: function(models) {_x000D_
        // associations can be defined here_x000D_
      }_x000D_
    }_x000D_
  });_x000D_
  return MyUser;_x000D_
};
_x000D_
_x000D_
_x000D_

migrations/20150210104840-create-my-user.js:

_x000D_
_x000D_
"use strict";_x000D_
module.exports = {_x000D_
  up: function(migration, DataTypes, done) {_x000D_
    migration.createTable("MyUsers", {_x000D_
      id: {_x000D_
        allowNull: false,_x000D_
        autoIncrement: true,_x000D_
        primaryKey: true,_x000D_
        type: DataTypes.INTEGER_x000D_
      },_x000D_
      first_name: {_x000D_
        type: DataTypes.STRING_x000D_
      },_x000D_
      last_name: {_x000D_
        type: DataTypes.STRING_x000D_
      },_x000D_
      bio: {_x000D_
        type: DataTypes.TEXT_x000D_
      },_x000D_
      createdAt: {_x000D_
        allowNull: false,_x000D_
        type: DataTypes.DATE_x000D_
      },_x000D_
      updatedAt: {_x000D_
        allowNull: false,_x000D_
        type: DataTypes.DATE_x000D_
      }_x000D_
    }).done(done);_x000D_
  },_x000D_
  down: function(migration, DataTypes, done) {_x000D_
    migration.dropTable("MyUsers").done(done);_x000D_
  }_x000D_
};
_x000D_
_x000D_
_x000D_

Regular expression "^[a-zA-Z]" or "[^a-zA-Z]"

Yes, the first means "match all strings that start with a letter", the second means "match all strings that contain a non-letter". The caret ("^") is used in two different ways, one to signal the start of the text, one to negate a character match inside square brackets.

How to append to a file in Node?

Your code using createWriteStream creates a file descriptor for every write. log.end is better because it asks node to close immediately after the write.

var fs = require('fs');
var logStream = fs.createWriteStream('log.txt', {flags: 'a'});
// use {flags: 'a'} to append and {flags: 'w'} to erase and write a new file
logStream.write('Initial line...');
logStream.end('this is the end line');

How can I access getSupportFragmentManager() in a fragment?

You can use getActivity().getSupportFragmentManager() anytime you want to getSupportFragmentManager.

hierarchy is Activity -> fragment. fragment is not capable of directly calling getSupportFragmentManger but Activity can . Thus, you can use getActivity to call the current activity which the fragment is in and get getSupportFragmentManager()

Typescript - multidimensional array initialization

If you want to do it typed:

class Something {

  areas: Area[][];

  constructor() {
    this.areas = new Array<Array<Area>>();
    for (let y = 0; y <= 100; y++) {
      let row:Area[]  = new Array<Area>();      
      for (let x = 0; x <=100; x++){
        row.push(new Area(x, y));
      }
      this.areas.push(row);
    }
  }
}

How does one target IE7 and IE8 with valid CSS?

I would recommend looking into conditional comments and making a separate sheet for the IEs you are having problems with.

 <!--[if IE 7]>
   <link rel="stylesheet" type="text/css" href="ie7.css" />
 <![endif]-->

Passing HTML to template using Flask/Jinja2

You can also declare it HTML safe from the code:

from flask import Markup
value = Markup('<strong>The HTML String</strong>')

Then pass that value to the templates and they don't have to |safe it.

Oracle comparing timestamp with date

You can truncate the date part:

select * from table1 where trunc(field1) = to_date('2012-01-01', 'YYYY-MM-DD')

The trouble with this approach is that any index on field1 wouldn't be used due to the function call.

Alternatively (and more index friendly)

select * from table1 
 where field1 >= to_timestamp('2012-01-01', 'YYYY-MM-DD') 
   and field1 < to_timestamp('2012-01-02', 'YYYY-MM-DD')

Android: Create a toggle button with image and no text

ToggleButton inherits from TextView so you can set drawables to be displayed at the 4 borders of the text. You can use that to display the icon you want on top of the text and hide the actual text

<ToggleButton
    android:id="@+id/toggleButton1"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:drawableTop="@android:drawable/ic_menu_info_details"
    android:gravity="center"
    android:textOff=""
    android:textOn=""
    android:textSize="0dp" />

The result compared to regular ToggleButton looks like

enter image description here

The seconds option is to use an ImageSpan to actually replace the text with an image. Looks slightly better since the icon is at the correct position but can't be done with layout xml directly.

You create a plain ToggleButton

<ToggleButton
    android:id="@+id/toggleButton3"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:checked="false" />

Then set the "text" programmatially

ToggleButton button = (ToggleButton) findViewById(R.id.toggleButton3);
ImageSpan imageSpan = new ImageSpan(this, android.R.drawable.ic_menu_info_details);
SpannableString content = new SpannableString("X");
content.setSpan(imageSpan, 0, 1, Spanned.SPAN_EXCLUSIVE_EXCLUSIVE);
button.setText(content);
button.setTextOn(content);
button.setTextOff(content);

The result here in the middle - icon is placed slightly lower since it takes the place of the text.

enter image description here

ASP.NET MVC DropDownListFor with model of type List<string>

To make a dropdown list you need two properties:

  1. a property to which you will bind to (usually a scalar property of type integer or string)
  2. a list of items containing two properties (one for the values and one for the text)

In your case you only have a list of string which cannot be exploited to create a usable drop down list.

While for number 2. you could have the value and the text be the same you need a property to bind to. You could use a weakly typed version of the helper:

@model List<string>
@Html.DropDownList(
    "Foo", 
    new SelectList(
        Model.Select(x => new { Value = x, Text = x }),
        "Value",
        "Text"
    )
)

where Foo will be the name of the ddl and used by the default model binder. So the generated markup might look something like this:

<select name="Foo" id="Foo">
    <option value="item 1">item 1</option>
    <option value="item 2">item 2</option>
    <option value="item 3">item 3</option>
    ...
</select>

This being said a far better view model for a drop down list is the following:

public class MyListModel
{
    public string SelectedItemId { get; set; }
    public IEnumerable<SelectListItem> Items { get; set; }
}

and then:

@model MyListModel
@Html.DropDownListFor(
    x => x.SelectedItemId,
    new SelectList(Model.Items, "Value", "Text")
)

and if you wanted to preselect some option in this list all you need to do is to set the SelectedItemId property of this view model to the corresponding Value of some element in the Items collection.

registerForRemoteNotificationTypes: is not supported in iOS 8.0 and later

After Xcode 6.1 Beta the code below works, slight edit on Tom S code that stopped working with the 6.1 beta (worked with previous beta):

   if UIApplication.sharedApplication().respondsToSelector("registerUserNotificationSettings:") {
        // It's iOS 8
        var types = UIUserNotificationType.Badge | UIUserNotificationType.Sound | UIUserNotificationType.Alert
       var settings = UIUserNotificationSettings(forTypes: types, categories: nil)
       UIApplication.sharedApplication().registerUserNotificationSettings(settings)
    } else {
        // It's older
        var types = UIRemoteNotificationType.Badge | UIRemoteNotificationType.Sound | UIRemoteNotificationType.Alert
        UIApplication.sharedApplication().registerForRemoteNotificationTypes(types)
    }

How to get MAC address of client using PHP?

The MAC address (the low-level local network interface address) does not survive hops through IP routers. You can't find the client MAC address from a remote server.

In a local subnet, the MAC addresses are mapped to IP addresses through the ARP system. Interfaces on the local net know how to map IP addresses to MAC addresses. However, when your packets have been routed on the local subnet to (and through) the gateway out to the "real" Internet, the originating MAC address is lost. Simplistically, each subnet-to-subnet hop of your packets involve the same sort of IP-to-MAC mapping for local routing in each subnet.

How to get the size of a file in MB (Megabytes)?

You can retrieve the length of the file with File#length(), which will return a value in bytes, so you need to divide this by 1024*1024 to get its value in mb.

Where is the WPF Numeric UpDown control?

Use VerticalScrollBar with the TextBlock control in WPF. In your code behind, add the following code:

In the constructor, define an event handler for the scrollbar:

scrollBar1.ValueChanged += new RoutedPropertyChangedEventHandler<double>(scrollBar1_ValueChanged);
scrollBar1.Minimum = 0;
scrollBar1.Maximum = 1;
scrollBar1.SmallChange = 0.1;

Then in the event handler, add:

void scrollBar1_ValueChanged(object sender, RoutedPropertyChangedEventArgs<double> e)
{
    FteHolderText.Text = scrollBar1.Value.ToString();
}

Here is the original snippet from my code... make necessary changes.. :)

public NewProjectPlan()
{
    InitializeComponent();

    this.Loaded += new RoutedEventHandler(NewProjectPlan_Loaded);

    scrollBar1.ValueChanged += new RoutedPropertyChangedEventHandler<double>(scrollBar1_ValueChanged);
    scrollBar1.Minimum = 0;
    scrollBar1.Maximum = 1;
    scrollBar1.SmallChange = 0.1;

    // etc...
}

void scrollBar1_ValueChanged(object sender, RoutedPropertyChangedEventArgs<double> e)
{
    FteHolderText.Text = scrollBar1.Value.ToString();
}

How do I PHP-unserialize a jQuery-serialized form?

Why don't use associative array, so you can use it easily

function unserializeForm($str) {
    $returndata = array();
    $strArray = explode("&", $str);
    $i = 0;
    foreach ($strArray as $item) {
        $array = explode("=", $item);
        $returndata[$array[0]] = $array[1];
    }

    return $returndata;
}

Regards

Return datetime object of previous month

For most use cases, what about

from datetime import date

current_date =date.today()
current_month = current_date.month
last_month = current_month - 1 if current_month != 1 else 12  
today_a_month_ago = date(current_date.year, last_month, current_date.day)

That seems the simplest to me.

Note: I've added the second to last line so that it would work if the current month is January as per @Nick's comment

Note 2: In most cases, if the current date is the 31st of a given month the result will be an invalid date as the previous month would not have 31 days (Except for July & August), as noted by @OneCricketeer

How do the PHP equality (== double equals) and identity (=== triple equals) comparison operators differ?

You would use === to test whether a function or variable is false rather than just equating to false (zero or an empty string).

$needle = 'a';
$haystack = 'abc';
$pos = strpos($haystack, $needle);
if ($pos === false) {
    echo $needle . ' was not found in ' . $haystack;
} else {
    echo $needle . ' was found in ' . $haystack . ' at location ' . $pos;
}

In this case strpos would return 0 which would equate to false in the test

if ($pos == false)

or

if (!$pos)

which is not what you want here.

Oracle Convert Seconds to Hours:Minutes:Seconds

Assuming your time is called st.etime below and stored in seconds, here is what I use. This handles times where the seconds are greater than 86399 seconds (which is 11:59:59 pm)

case when st.etime > 86399 then to_char(to_date(st.etime - 86400,'sssss'),'HH24:MI:SS') else to_char(to_date(st.etime,'sssss'),'HH24:MI:SS') end readable_time

How to change the default background color white to something else in twitter bootstrap

The colors changed due to the order of CSS files.

Place the custom CSS under the bootstrap CSS.

Add CSS or JavaScript files to layout head from views or partial views

I had a similar problem, and ended up applying Kalman's excellent answer with the code below (not quite as neat, but arguably more expansible):

namespace MvcHtmlHelpers
{
    //http://stackoverflow.com/questions/5110028/add-css-or-js-files-to-layout-head-from-views-or-partial-views#5148224
    public static partial class HtmlExtensions
    {
        public static AssetsHelper Assets(this HtmlHelper htmlHelper)
        {
            return AssetsHelper.GetInstance(htmlHelper);
        }
    }
    public enum BrowserType { Ie6=1,Ie7=2,Ie8=4,IeLegacy=7,W3cCompliant=8,All=15}
    public class AssetsHelper
    {
        public static AssetsHelper GetInstance(HtmlHelper htmlHelper)
        {
            var instanceKey = "AssetsHelperInstance";
            var context = htmlHelper.ViewContext.HttpContext;
            if (context == null) {return null;}
            var assetsHelper = (AssetsHelper)context.Items[instanceKey];
            if (assetsHelper == null){context.Items.Add(instanceKey, assetsHelper = new AssetsHelper(htmlHelper));}
            return assetsHelper;
        }
        private readonly List<string> _styleRefs = new List<string>();
        public AssetsHelper AddStyle(string stylesheet)
        {
            _styleRefs.Add(stylesheet);
            return this;
        }
        private readonly List<string> _scriptRefs = new List<string>();
        public AssetsHelper AddScript(string scriptfile)
        {
            _scriptRefs.Add(scriptfile);
            return this;
        }
        public IHtmlString RenderStyles()
        {
            ItemRegistrar styles = new ItemRegistrar(ItemRegistrarFormatters.StyleFormat,_urlHelper);
            styles.Add(Libraries.UsedStyles());
            styles.Add(_styleRefs);
            return styles.Render();
        }
        public IHtmlString RenderScripts()
        {
            ItemRegistrar scripts = new ItemRegistrar(ItemRegistrarFormatters.ScriptFormat, _urlHelper);
            scripts.Add(Libraries.UsedScripts());
            scripts.Add(_scriptRefs);
            return scripts.Render();
        }
        public LibraryRegistrar Libraries { get; private set; }
        private UrlHelper _urlHelper;
        public AssetsHelper(HtmlHelper htmlHelper)
        {
            _urlHelper = new UrlHelper(htmlHelper.ViewContext.RequestContext);
            Libraries = new LibraryRegistrar();
        }
    }
    public class LibraryRegistrar
    {
        public class Component
        {
            internal class HtmlReference
            {
                internal string Url { get; set; }
                internal BrowserType ServeTo { get; set; }
            }
            internal List<HtmlReference> Styles { get; private set; }
            internal List<HtmlReference> Scripts { get; private set; }
            internal List<string> RequiredLibraries { get; private set; }

            public Component()
            {
                Styles = new List<HtmlReference>();
                Scripts = new List<HtmlReference>();
                RequiredLibraries = new List<string>();
            }
            public Component Requires(params string[] libraryNames)
            {
                foreach (var lib in libraryNames)
                {
                    if (!RequiredLibraries.Contains(lib))
                        { RequiredLibraries.Add(lib); }
                }
                return this;
            }
            public Component AddStyle(string url, BrowserType serveTo = BrowserType.All)
            {
                Styles.Add(new HtmlReference { Url = url, ServeTo=serveTo });
                return this;
            }
            public Component AddScript(string url, BrowserType serveTo = BrowserType.All)
            {
                Scripts.Add(new HtmlReference { Url = url, ServeTo = serveTo });
                return this;
            }
        }
        private readonly Dictionary<string, Component> _allLibraries = new Dictionary<string, Component>();
        private List<string> _usedLibraries = new List<string>();
        internal IEnumerable<string> UsedScripts()
        {
            SetOrder();
            var returnVal = new List<string>();
            foreach (var key in _usedLibraries)
            {
                returnVal.AddRange(from s in _allLibraries[key].Scripts
                                   where IncludesCurrentBrowser(s.ServeTo)
                                   select s.Url);
            }
            return returnVal;
        }
        internal IEnumerable<string> UsedStyles()
        {
            SetOrder();
            var returnVal = new List<string>();
            foreach (var key in _usedLibraries)
            {
                returnVal.AddRange(from s in _allLibraries[key].Styles
                                   where IncludesCurrentBrowser(s.ServeTo)
                                   select s.Url);
            }
            return returnVal;
        }
        public void Uses(params string[] libraryNames)
        {
            foreach (var name in libraryNames)
            {
                if (!_usedLibraries.Contains(name)){_usedLibraries.Add(name);}
            }
        }
        public bool IsUsing(string libraryName)
        {
            SetOrder();
            return _usedLibraries.Contains(libraryName);
        }
        private List<string> WalkLibraryTree(List<string> libraryNames)
        {
            var returnList = new List<string>(libraryNames);
            int counter = 0;
            foreach (string libraryName in libraryNames)
            {
                WalkLibraryTree(libraryName, ref returnList, ref counter);
            }
            return returnList;
        }
        private void WalkLibraryTree(string libraryName, ref List<string> libBuild, ref int counter)
        {
            if (counter++ > 1000) { throw new System.Exception("Dependancy library appears to be in infinate loop - please check for circular reference"); }
            Component library;
            if (!_allLibraries.TryGetValue(libraryName, out library))
                { throw new KeyNotFoundException("Cannot find a definition for the required style/script library named: " + libraryName); }
            foreach (var childLibraryName in library.RequiredLibraries)
            {
                int childIndex = libBuild.IndexOf(childLibraryName);
                if (childIndex!=-1)
                {
                    //child already exists, so move parent to position before child if it isn't before already
                    int parentIndex = libBuild.LastIndexOf(libraryName);
                    if (parentIndex>childIndex)
                    {
                        libBuild.RemoveAt(parentIndex);
                        libBuild.Insert(childIndex, libraryName);
                    }
                }
                else
                {
                    libBuild.Add(childLibraryName);
                    WalkLibraryTree(childLibraryName, ref libBuild, ref counter);
                }
            }
            return;
        }
        private bool _dependenciesExpanded;
        private void SetOrder()
        {
            if (_dependenciesExpanded){return;}
            _usedLibraries = WalkLibraryTree(_usedLibraries);
            _usedLibraries.Reverse();
            _dependenciesExpanded = true;
        }
        public Component this[string index]
        {
            get
            {
                if (_allLibraries.ContainsKey(index))
                    { return _allLibraries[index]; }
                var newComponent = new Component();
                _allLibraries.Add(index, newComponent);
                return newComponent;
            }
        }
        private BrowserType _requestingBrowser;
        private BrowserType RequestingBrowser
        {
            get
            {
                if (_requestingBrowser == 0)
                {
                    var browser = HttpContext.Current.Request.Browser.Type;
                    if (browser.Length > 2 && browser.Substring(0, 2) == "IE")
                    {
                        switch (browser[2])
                        {
                            case '6':
                                _requestingBrowser = BrowserType.Ie6;
                                break;
                            case '7':
                                _requestingBrowser = BrowserType.Ie7;
                                break;
                            case '8':
                                _requestingBrowser = BrowserType.Ie8;
                                break;
                            default:
                                _requestingBrowser = BrowserType.W3cCompliant;
                                break;
                        }
                    }
                    else
                    {
                        _requestingBrowser = BrowserType.W3cCompliant;
                    }
                }
                return _requestingBrowser;
            }
        }
        private bool IncludesCurrentBrowser(BrowserType browserType)
        {
            if (browserType == BrowserType.All) { return true; }
            return (browserType & RequestingBrowser) != 0;
        }
    }
    public class ItemRegistrar
    {
        private readonly string _format;
        private readonly List<string> _items;
        private readonly UrlHelper _urlHelper;

        public ItemRegistrar(string format, UrlHelper urlHelper)
        {
            _format = format;
            _items = new List<string>();
            _urlHelper = urlHelper;
        }
        internal void Add(IEnumerable<string> urls)
        {
            foreach (string url in urls)
            {
                Add(url);
            }
        }
        public ItemRegistrar Add(string url)
        {
            url = _urlHelper.Content(url);
            if (!_items.Contains(url))
                { _items.Add( url); }
            return this;
        }
        public IHtmlString Render()
        {
            var sb = new StringBuilder();
            foreach (var item in _items)
            {
                var fmt = string.Format(_format, item);
                sb.AppendLine(fmt);
            }
            return new HtmlString(sb.ToString());
        }
    }
    public class ItemRegistrarFormatters
    {
        public const string StyleFormat = "<link href=\"{0}\" rel=\"stylesheet\" type=\"text/css\" />";
        public const string ScriptFormat = "<script src=\"{0}\" type=\"text/javascript\"></script>";
    }
}

The project contains a static AssignAllResources method:

assets.Libraries["jQuery"]
        .AddScript("~/Scripts/jquery-1.10.0.min.js", BrowserType.IeLegacy)
        .AddScript("~/Scripts//jquery-2.0.1.min.js",BrowserType.W3cCompliant);
        /* NOT HOSTED YET - CHECK SOON 
        .AddScript("//ajax.googleapis.com/ajax/libs/jquery/2.0.1/jquery.min.js",BrowserType.W3cCompliant);
        */
    assets.Libraries["jQueryUI"].Requires("jQuery")
        .AddScript("//ajax.googleapis.com/ajax/libs/jqueryui/1.9.2/jquery-ui.min.js",BrowserType.Ie6)
        .AddStyle("//ajax.aspnetcdn.com/ajax/jquery.ui/1.9.2/themes/eggplant/jquery-ui.css",BrowserType.Ie6)
        .AddScript("//ajax.googleapis.com/ajax/libs/jqueryui/1.10.3/jquery-ui.min.js", ~BrowserType.Ie6)
        .AddStyle("//ajax.aspnetcdn.com/ajax/jquery.ui/1.10.3/themes/eggplant/jquery-ui.css", ~BrowserType.Ie6);
    assets.Libraries["TimePicker"].Requires("jQueryUI")
        .AddScript("~/Scripts/jquery-ui-sliderAccess.min.js")
        .AddScript("~/Scripts/jquery-ui-timepicker-addon-1.3.min.js")
        .AddStyle("~/Content/jQueryUI/jquery-ui-timepicker-addon.css");
    assets.Libraries["Validation"].Requires("jQuery")
        .AddScript("//ajax.aspnetcdn.com/ajax/jquery.validate/1.11.1/jquery.validate.min.js")
        .AddScript("~/Scripts/jquery.validate.unobtrusive.min.js")
        .AddScript("~/Scripts/mvcfoolproof.unobtrusive.min.js")
        .AddScript("~/Scripts/CustomClientValidation-1.0.0.min.js");
    assets.Libraries["MyUtilityScripts"].Requires("jQuery")
        .AddScript("~/Scripts/GeneralOnLoad-1.0.0.min.js");
    assets.Libraries["FormTools"].Requires("Validation", "MyUtilityScripts");
    assets.Libraries["AjaxFormTools"].Requires("FormTools", "jQueryUI")
        .AddScript("~/Scripts/jquery.unobtrusive-ajax.min.js");
    assets.Libraries["DataTables"].Requires("MyUtilityScripts")
        .AddScript("//ajax.aspnetcdn.com/ajax/jquery.dataTables/1.9.4/jquery.dataTables.min.js")
        .AddStyle("//ajax.aspnetcdn.com/ajax/jquery.dataTables/1.9.4/css/jquery.dataTables.css")
        .AddStyle("//ajax.aspnetcdn.com/ajax/jquery.dataTables/1.9.4/css/jquery.dataTables_themeroller.css");
    assets.Libraries["MvcDataTables"].Requires("DataTables", "jQueryUI")
        .AddScript("~/Scripts/jquery.dataTables.columnFilter.min.js");
    assets.Libraries["DummyData"].Requires("MyUtilityScripts")
        .AddScript("~/Scripts/DummyData.js")
        .AddStyle("~/Content/DummyData.css");     

in the _layout page

@{
    var assets = Html.Assets();
    CurrentResources.AssignAllResources(assets);
    Html.Assets().RenderStyles()
}
</head>
...
    @Html.Assets().RenderScripts()
</body>

and in the partial(s) and views

Html.Assets().Libraries.Uses("DataTables");
Html.Assets().AddScript("~/Scripts/emailGridUtilities.js");

What does -1 mean in numpy reshape?

import numpy as np
x = np.array([[2,3,4], [5,6,7]]) 

# Convert any shape to 1D shape
x = np.reshape(x, (-1)) # Making it 1 row -> (6,)

# When you don't care about rows and just want to fix number of columns
x = np.reshape(x, (-1, 1)) # Making it 1 column -> (6, 1)
x = np.reshape(x, (-1, 2)) # Making it 2 column -> (3, 2)
x = np.reshape(x, (-1, 3)) # Making it 3 column -> (2, 3)

# When you don't care about columns and just want to fix number of rows
x = np.reshape(x, (1, -1)) # Making it 1 row -> (1, 6)
x = np.reshape(x, (2, -1)) # Making it 2 row -> (2, 3)
x = np.reshape(x, (3, -1)) # Making it 3 row -> (3, 2)

AngularJS : The correct way of binding to a service properties

Consider some pros and cons of the second approach:

  • 0 {{lastUpdated}} instead of {{timerData.lastUpdated}}, which could just as easily be {{timer.lastUpdated}}, which I might argue is more readable (but let's not argue... I'm giving this point a neutral rating so you decide for yourself)

  • +1 It may be convenient that the controller acts as a sort of API for the markup such that if somehow the structure of the data model changes you can (in theory) update the controller's API mappings without touching the html partial.

  • -1 However, theory isn't always practice and I usually find myself having to modify markup and controller logic when changes are called for, anyway. So the extra effort of writing the API negates it's advantage.

  • -1 Furthermore, this approach isn't very DRY.

  • -1 If you want to bind the data to ng-model your code become even less DRY as you have to re-package the $scope.scalar_values in the controller to make a new REST call.

  • -0.1 There's a tiny performance hit creating extra watcher(s). Also, if data properties are attached to the model that don't need to be watched in a particular controller they will create additional overhead for the deep watchers.

  • -1 What if multiple controllers need the same data models? That means that you have multiple API's to update with every model change.

$scope.timerData = Timer.data; is starting to sound mighty tempting right about now... Let's dive a little deeper into that last point... What kind of model changes were we talking about? A model on the back-end (server)? Or a model which is created and lives only in the front-end? In either case, what is essentially the data mapping API belongs in the front-end service layer, (an angular factory or service). (Note that your first example--my preference-- doesn't have such an API in the service layer, which is fine because it's simple enough it doesn't need it.)

In conclusion, everything does not have to be decoupled. And as far as decoupling the markup entirely from the data model, the drawbacks outweigh the advantages.


Controllers, in general shouldn't be littered with $scope = injectable.data.scalar's. Rather, they should be sprinkled with $scope = injectable.data's, promise.then(..)'s, and $scope.complexClickAction = function() {..}'s

As an alternative approach to achieve data-decoupling and thus view-encapsulation, the only place that it really makes sense to decouple the view from the model is with a directive. But even there, don't $watch scalar values in the controller or link functions. That won't save time or make the code any more maintainable nor readable. It won't even make testing easier since robust tests in angular usually test the resulting DOM anyway. Rather, in a directive demand your data API in object form, and favor using just the $watchers created by ng-bind.


Example http://plnkr.co/edit/MVeU1GKRTN4bqA3h9Yio

<body ng-app="ServiceNotification">
    <div style="border-style:dotted" ng-controller="TimerCtrl1">
        TimerCtrl1<br/>
        Bad:<br/>
        Last Updated: {{lastUpdated}}<br/>
        Last Updated: {{calls}}<br/>
        Good:<br/>
        Last Updated: {{data.lastUpdated}}<br/>
        Last Updated: {{data.calls}}<br/>
    </div>

    <script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.0.5/angular.js"></script>
    <script type="text/javascript">
        var app = angular.module("ServiceNotification", []);

        function TimerCtrl1($scope, Timer) {
            $scope.data = Timer.data;
            $scope.lastUpdated = Timer.data.lastUpdated;
            $scope.calls = Timer.data.calls;
        };

        app.factory("Timer", function ($timeout) {
            var data = { lastUpdated: new Date(), calls: 0 };

            var updateTimer = function () {
                data.lastUpdated = new Date();
                data.calls += 1;
                console.log("updateTimer: " + data.lastUpdated);

                $timeout(updateTimer, 500);
            };
            updateTimer();

            return {
                data: data
            };
        });
    </script>
</body>

UPDATE: I've finally come back to this question to add that I don't think that either approach is "wrong". Originally I had written that Josh David Miller's answer was incorrect, but in retrospect his points are completely valid, especially his point about separation of concerns.

Separation of concerns aside (but tangentially related), there's another reason for defensive copying that I failed to consider. This question mostly deals with reading data directly from a service. But what if a developer on your team decides that the controller needs to transform the data in some trivial way before the view displays it? (Whether controllers should transform data at all is another discussion.) If she doesn't make a copy of the object first she might unwittingly cause regressions in another view component which consumes the same data.

What this question really highlights are architectural shortcomings of the typical angular application (and really any JavaScript application): tight coupling of concerns, and object mutability. I have recently become enamored with architecting application with React and immutable data structures. Doing so solves the following two problems wonderfully:

  1. Separation of concerns: A component consumes all of it's data via props and has little-to-no reliance on global singletons (such as Angular services), and knows nothing about what happened above it in the view hierarchy.

  2. Mutability: All props are immutable which eliminates the risk of unwitting data mutation.

Angular 2.0 is now on track to borrow heavily from React to achieve the two points above.

Proxy setting for R

Inspired by all the responses related on the internet, finally I've found the solution to correctly configure the Proxy for R and Rstudio.

There are several steps to follow, perhaps some of the steps are useless, but the combination works!

  1. Add environment variables http_proxy and https_proxy with proxy details.

    variable name: http_proxy
    variable value: https://user_id:password@your_proxy:your_port/
    
    variable name: https_proxy
    variable value: https:// user_id:password@your_proxy:your_port
    
  2. If you start R from a desktop icon, you can add the --internet flag to the target line (right click -> Properties)

    e.g."C:\Program Files\R\R-2.8.1\bin\Rgui.exe" --internet2

  3. For RStudio just you have to do this:

    Firstly, open RStudio like always, select from the top menu:

    Tools-Global Options-Packages

    Uncheck the option: Use Internet Explorer library/proxy for HTTP

  4. Find the file (.Renviron) in your computer, most probably you would find it here: C:\Users\your user name\Documents.

    Note that: if it does not exist you can create it just by writing this command in R:

    file.edit('~/.Renviron')
    

    Then add these six lines to the initials of the file:

    options(internet.info = 0)
    
    http_proxy = https:// user_id:password@your_proxy:your_port
    
    http_proxy_user = user_id:password
    
    https_proxy = https:// user_id:password0@your_proxy:your_port
    
    https_proxy_user = user_id:password
    
    ftp_proxy = user_id:password@your_proxy:your_port
    
  5. Restart R. Type the following commands in R to assure that the configuration above works well:

    Sys.getenv("http_proxy")
    
    Sys.getenv("http_proxy_user")
    
    Sys.getenv("https_proxy")
    
    Sys.getenv("https_proxy_user")
    
    Sys.getenv("ftp_proxy")
    
  6. Now you can install the packages as you want by using the command like:

    install.packages("mlr",method="libcurl")
    

    It's important to add method="libcurl", otherwise it won't work.

How to git commit a single file/directory

Specify path after entered commit message, like:

git commit -m "commit message" path/to/file.extention

How to find prime numbers between 0 - 100?

You can try this method also, this one is basic but easy to understand:

 var tw = 2, th = 3, fv = 5, se = 7; 

 document.write(tw + "," + th + ","+ fv + "," + se + ",");


for(var n = 0; n <= 100; n++)
{

  if((n % tw !== 0) && (n % th !==0) && (n % fv !==0 ) && (n % se !==0))

  {
      if (n == 1)
      {
          continue;
      }

    document.write(n +",");
  }
}

CSS hide scroll bar if not needed

Set overflow-y property to auto, or remove the property altogether if it is not inherited.

Multiple line comment in Python

#Single line

'''
multi-line
comment
'''

"""
also, 
multi-line comment
"""

What does SQL clause "GROUP BY 1" mean?

SELECT account_id, open_emp_id
         ^^^^        ^^^^
          1           2

FROM account
GROUP BY 1;

In above query GROUP BY 1 refers to the first column in select statement which is account_id.

You also can specify in ORDER BY.

Note : The number in ORDER BY and GROUP BY always start with 1 not with 0.

How to click an element in Selenium WebDriver using JavaScript

Cross browser testing java scripts

public class MultipleBrowser {

    public WebDriver driver= null;
    String browser="mozilla";
    String url="https://www.omnicard.com";

    @BeforeMethod
    public void LaunchBrowser() {

        if(browser.equalsIgnoreCase("mozilla"))
            driver= new FirefoxDriver();
        else if(browser.equalsIgnoreCase("safari"))
            driver= new SafariDriver();
        else if(browser.equalsIgnoreCase("chrome"))
            //System.setProperty("webdriver.chrome.driver","/Users/mhossain/Desktop/chromedriver");
            driver= new ChromeDriver(); 
        driver.manage().timeouts().implicitlyWait(4, TimeUnit.SECONDS);
        driver.navigate().to(url);
    }

}

but when you want to run firefox you need to chrome path disable, otherwise browser will launch but application may not.(try both way) .

How to solve privileges issues when restore PostgreSQL Database

To solve the issue you must assign the proper ownership permissions. Try the below which should resolve all permission related issues for specific users but as stated in the comments this should not be used in production:

root@server:/var/log/postgresql# sudo -u postgres psql
psql (8.4.4)
Type "help" for help.

postgres=# \du
               List of roles
    Role name    | Attributes  | Member of
-----------------+-------------+-----------
 <user-name>    | Superuser   | {}
                 : Create DB
 postgres       | Superuser   | {}
                 : Create role
                 : Create DB

postgres=# alter role <user-name> superuser;
ALTER ROLE
postgres=#

So connect to the database under a Superuser account sudo -u postgres psql and execute a ALTER ROLE <user-name> Superuser; statement.

Keep in mind this is not the best solution on multi-site hosting server so take a look at assigning individual roles instead: https://www.postgresql.org/docs/current/static/sql-set-role.html and https://www.postgresql.org/docs/current/static/sql-alterrole.html.

How can I bind to the change event of a textarea in jQuery?

Use an input event.

var button = $("#buttonId");
$("#textareaID").on('input',function(e){
  if(e.target.value === ''){
    // Textarea has no value
    button.hide();
  } else {
    // Textarea has a value
    button.show();
  }
});

Hide a EditText & make it visible by clicking a menu

Try phoneNumber.setVisibility(View.GONE);

Is there any way of configuring Eclipse IDE proxy settings via an autoproxy configuration script?

Download proxy script and check last line for return statement Proxy IP and Port.
Add this IP and Port using these step.

   1.  Windows -->Preferences-->General -->Network Connection
   2. Select Active Provider : Manual
   3.  Proxy entries select HTTP--> Click on Edit button
   4.  Then add Host as a proxy IP and port left Required Authentication blank.
   5.  Restart eclipse
   6.  Now Eclipse Marketplace... working.

No module named 'pymysql'

sudo apt-get install python3-pymysql

This command also works for me to install the package required for Flask app to tun on ubuntu 16x with WISG module on APACHE2 server.

BY default on WSGI uses python 3 installation of UBUNTU.

Anaconda custom installation won't work.

How can I populate a select dropdown list from a JSON feed with AngularJS?

The proper way to do it is using the ng-options directive. The HTML would look like this.

<select ng-model="selectedTestAccount" 
        ng-options="item.Id as item.Name for item in testAccounts">
    <option value="">Select Account</option>
</select>

JavaScript:

angular.module('test', []).controller('DemoCtrl', function ($scope, $http) {
    $scope.selectedTestAccount = null;
    $scope.testAccounts = [];

    $http({
            method: 'GET',
            url: '/Admin/GetTestAccounts',
            data: { applicationId: 3 }
        }).success(function (result) {
        $scope.testAccounts = result;
    });
});

You'll also need to ensure angular is run on your html and that your module is loaded.

<html ng-app="test">
    <body ng-controller="DemoCtrl">
    ....
    </body>
</html>

Anonymous method in Invoke call

I never understood why this makes a difference for the compiler, but this is sufficient.

public static class ControlExtensions
{
    public static void Invoke(this Control control, Action action)
    {
        control.Invoke(action);
    }
}

Bonus: add some error handling, because it is likely that, if you are using Control.Invoke from a background thread you are updating the text / progress / enabled state of a control and don't care if the control is already disposed.

public static class ControlExtensions
{
    public static void Invoke(this Control control, Action action)
    {
        try
        {
            if (!control.IsDisposed) control.Invoke(action);
        }
        catch (ObjectDisposedException) { }
    }
}

Tesseract running error

You can grab eng.traineddata Github:

wget https://github.com/tesseract-ocr/tessdata/raw/master/eng.traineddata

Check https://github.com/tesseract-ocr/tessdata for a full list of trained language data.

When you grab the file(s), move them to the /usr/local/share/tessdata folder. Warning: some Linux distributions (such as openSUSE and Ubuntu) may be expecting it in /usr/share/tessdata instead.

# If you got the data from Google, unzip it first!
gunzip eng.traineddata.gz 
# Move the data
sudo mv -v eng.traineddata /usr/local/share/tessdata/

How to include layout inside layout?

Note that if you include android:id... into the <include /> tag, it will override whatever id was defined inside the included layout. For example:

<include
   android:layout_width="fill_parent"
   android:layout_height="wrap_content"
   android:id="@+id/some_id_if_needed"
   layout="@layout/yourlayout" />

yourlayout.xml:

<LinearLayout
   android:layout_width="fill_parent"
   android:layout_height="wrap_content"
   android:id="@+id/some_other_id">
   <Button
       android:layout_width="fill_parent"
       android:layout_height="wrap_content"
       android:id="@+id/button1" />
 </LinearLayout>

Then you would reference this included layout in code as follows:

View includedLayout = findViewById(R.id.some_id_if_needed);
Button insideTheIncludedLayout = (Button)includedLayout.findViewById(R.id.button1);

MySQL export into outfile : CSV escaping chars

I think your statement should look like:

SELECT id, 
   client,
   project,
   task,
   description, 
   time,
   date  
  INTO OUTFILE '/path/to/file.csv'
  FIELDS TERMINATED BY ',' OPTIONALLY ENCLOSED BY '"'
  LINES TERMINATED BY '\n'
  FROM ts

Mainly without the FIELDS ESCAPED BY '""' option, OPTIONALLY ENCLOSED BY '"' will do the trick for description fields etc and your numbers will be treated as numbers in Excel (not strings comprising of numerics)

Also try calling:

SET NAMES utf8;

before your outfile select, that might help getting the character encodings inline (all UTF8)

Let us know how you get on.

How do a send an HTTPS request through a proxy in Java?

Try the Apache Commons HttpClient library instead of trying to roll your own: http://hc.apache.org/httpclient-3.x/index.html

From their sample code:

  HttpClient httpclient = new HttpClient();
  httpclient.getHostConfiguration().setProxy("myproxyhost", 8080);

  /* Optional if authentication is required.
  httpclient.getState().setProxyCredentials("my-proxy-realm", " myproxyhost",
   new UsernamePasswordCredentials("my-proxy-username", "my-proxy-password"));
  */

  PostMethod post = new PostMethod("https://someurl");
  NameValuePair[] data = {
     new NameValuePair("user", "joe"),
     new NameValuePair("password", "bloggs")
  };
  post.setRequestBody(data);
  // execute method and handle any error responses.
  // ...
  InputStream in = post.getResponseBodyAsStream();
  // handle response.


  /* Example for a GET reqeust
  GetMethod httpget = new GetMethod("https://someurl");
  try { 
    httpclient.executeMethod(httpget);
    System.out.println(httpget.getStatusLine());
  } finally {
    httpget.releaseConnection();
  }
  */

How to add parameters to an external data query in Excel which can't be displayed graphically?

YES - solution is to save workbook in to XML file (eg. 'XML Spreadsheet 2003') and edit this file as text in notepad! use "SEARCH" function of notepad to find query text and change your data to "?".

save and open in excel, try refresh data and excel will be monit about parameters.

LEFT JOIN vs. LEFT OUTER JOIN in SQL Server

What is the difference between left join and left outer join?

Nothing. LEFT JOIN and LEFT OUTER JOIN are equivalent.

Serializing an object as UTF-8 XML in .NET

I found this blog post which explains the problem very well, and defines a few different solutions:

(dead link removed)

I've settled for the idea that the best way to do it is to completely omit the XML declaration when in memory. It actually is UTF-16 at that point anyway, but the XML declaration doesn't seem meaningful until it has been written to a file with a particular encoding; and even then the declaration is not required. It doesn't seem to break deserialization, at least.

As @Jon Hanna mentions, this can be done with an XmlWriter created like this:

XmlWriter writer = XmlWriter.Create (output, new XmlWriterSettings() { OmitXmlDeclaration = true });

Callback functions in Java

public class HelloWorldAnonymousClasses {

    //this is an interface with only one method
    interface HelloWorld {
        public void printSomething(String something);
    }

    //this is a simple function called from main()
    public void sayHello() {

    //this is an object with interface reference followed by the definition of the interface itself

        new HelloWorld() {
            public void printSomething(String something) {
                System.out.println("Hello " + something);
            }
        }.printSomething("Abhi");

     //imagine this as an object which is calling the function'printSomething()"
    }

    public static void main(String... args) {
        HelloWorldAnonymousClasses myApp =
                new HelloWorldAnonymousClasses();
        myApp.sayHello();
    }
}
//Output is "Hello Abhi"

Basically if you want to make the object of an interface it is not possible, because interface cannot have objects.

The option is to let some class implement the interface and then call that function using the object of that class. But this approach is really verbose.

Alternatively, write new HelloWorld() (*oberserve this is an interface not a class) and then follow it up with the defination of the interface methods itself. (*This defination is in reality the anonymous class). Then you get the object reference through which you can call the method itself.

Regex not operator

Not quite, although generally you can usually use some workaround on one of the forms

  • [^abc], which is character by character not a or b or c,
  • or negative lookahead: a(?!b), which is a not followed by b
  • or negative lookbehind: (?<!a)b, which is b not preceeded by a

Favicon dimensions?

Short answer

The favicon is supposed to be a set of 16x16, 32x32 and 48x48 pictures in ICO format. ICO format is different than PNG. Non-square pictures are not supported.

To generate the favicon, for many reasons explained below, I advise you to use this favicon generator. Full disclosure: I'm the author of this site.

Long, comprehensive answer

Favicon must be square. Desktop browsers and Apple iOS do not support non-square icons.

The favicon is supported by several files:

  • A favicon.ico icon.
  • Some other PNG icons.

In order to get the best results across desktop browsers (Windows/IE, MacOS/Safari, etc.), you need to combine both types of icons.

favicon.ico

Although all desktop browsers can deal with this icon, it is primarily for older version of IE.

The ICO format is different of the PNG format. This point is tricky because some browsers are smart enough to process a PNG picture correctly, even when it was wrongly renamed with an ICO extension.

An ICO file can contain several pictures and Microsoft recommends to put 16x16, 32x32 and 48x48 versions of the icon in favicon.ico. For example, IE will use the 16x16 version for the address bar, and the 32x32 for a task bar shortcut.

Declare the favicon with:

<link rel="icon" href="/path/to/icons/favicon.ico">

However, it is recommended to place favicon.ico in the root directory of the web site and to not declare it at all and let the modern browsers pick the PNG icons.

PNG icons

Modern desktop browsers (IE11, recent versions of Chrome, Firefox...) prefer to use PNG icons. The usual expected sizes are 16x16, 32x32 and "as big as possible". For example, MacOS/Safari uses the 196x196 icon if it is the biggest it can find.

What are the recommended sizes? Pick your favorite platforms:

The PNG icons are declared with:

<link rel="icon" type="image/png" href="/path/to/icons/favicon-16x16.png" sizes="16x16">
<link rel="icon" type="image/png" href="/path/to/icons/favicon-32x32.png" sizes="32x32">
...

Beware: Firefox does not support the sizes attribute and uses the last PNG icon it finds. Make sure to declare the 32x32 picture last: it is good enough for Firefox, and that will prevent it from downloading a big picture it does not need. edit: fixed in 2016.

Also note that Chrome does not support the sizes attribute and tends to load all declared icons. Better not declare too many icons. edit: fixed in 2018.

Mobile platforms

This question is about desktop favicon so there is no need to delve too much in this topic.

Apple defines touch icon for the iOS platform. iOS does not support non-square icon. It simply rescales non-square pictures to make them square (look for the Kioskea example).

Android Chrome relies on the Apple touch icon and also defines a 192x192 PNG icon.

Microsoft defines the tile picture and the browserconfig.xml file.

Conclusion

Generating a favicon that works everywhere is quite complex. I advise you to use this favicon generator. Full disclosure: I'm the author of this site.

Difference between onLoad and ng-init in angular

ng-init is a directive that can be placed inside div's, span's, whatever, whereas onload is an attribute specific to the ng-include directive that functions as an ng-init. To see what I mean try something like:

<span onload="a = 1">{{ a }}</span>
<span ng-init="b = 2">{{ b }}</span>

You'll see that only the second one shows up.

An isolated scope is a scope which does not prototypically inherit from its parent scope. In laymen's terms if you have a widget that doesn't need to read and write to the parent scope arbitrarily then you use an isolate scope on the widget so that the widget and widget container can freely use their scopes without overriding each other's properties.

How to plot a 2D FFT in Matlab?

Assuming that I is your input image and F is its Fourier Transform (i.e. F = fft2(I))

You can use this code:

F = fftshift(F); % Center FFT

F = abs(F); % Get the magnitude
F = log(F+1); % Use log, for perceptual scaling, and +1 since log(0) is undefined
F = mat2gray(F); % Use mat2gray to scale the image between 0 and 1

imshow(F,[]); % Display the result

I cannot access tomcat admin console?

This is all I did and restarted the server.

<tomcat-users>

  <role rolename="tomcat"/>
  <user username="tomcat" password="tomcat" roles="manager-gui"/>

</tomcat-users>

How to execute INSERT statement using JdbcTemplate class from Spring Framework

If you use spring-boot, you don't need to create a DataSource class, just specify the data url/username/password/driver in application.properties, then you can simply @Autowired it.

@Repository
public class JdbcRepository {

    private final JdbcTemplate jdbcTemplate;

    @Autowired
    public DynamicRepository(JdbcTemplate jdbcTemplate) {
        this.jdbcTemplate = jdbcTemplate;
    }

    public void insert() {
        jdbcTemplate.update("INSERT INTO BOOK (name, description) VALUES ('book name', 'book description')");
    }
}

Example of application.properties:

#Basic Spring Boot Config for Oracle
spring.datasource.url=jdbc:oracle:thin:@(DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=YourHostIP)(PORT=YourPort))(CONNECT_DATA=(SERVER=dedicated)(SERVICE_NAME=YourServiceName)))
spring.datasource.username=username
spring.datasource.password=password
spring.datasource.driver-class-name=oracle.jdbc.OracleDriver

#hibernate config
spring.jpa.database-platform=org.hibernate.dialect.Oracle10gDialect

Then add the driver and connection pool dependencies in pom.xml

<dependency>
    <groupId>com.oracle</groupId>
    <artifactId>ojdbc7</artifactId>
    <version>12.1.0.1</version>
</dependency>

<!-- HikariCP connection pool -->
<dependency>
    <groupId>com.zaxxer</groupId>
    <artifactId>HikariCP</artifactId>
    <version>2.6.0</version>
</dependency>

See the official doc for more details.

Change the "From:" address in Unix "mail"

mail -s "$(echo -e "This is the subject\nFrom: Paula <[email protected]>\n
Reply-to: [email protected]\nContent-Type: text/html\n")" 
[email protected] < htmlFileMessage.txt

the above is my solution....any extra headers can be added just after the from and before the reply to...just make sure you know your headers syntax before adding them....this worked perfectly for me.

Connect multiple devices to one device via Bluetooth

This is the class where the connection is established and messages are recieved. Make sure to pair the devices before you run the application. If you want to have a slave/master connection, where each slave can only send messages to the master , and the master can broadcast messages to all slaves. You should only pair the master with each slave , but you shouldn't pair the slaves together.

    package com.example.gaby.coordinatorv1;
    import java.io.DataInputStream;
    import java.io.IOException;
    import java.io.InputStream;
    import java.io.OutputStream;
    import java.util.ArrayList;
    import java.util.HashMap;
    import java.util.Set;
    import java.util.UUID;
    import android.bluetooth.BluetoothAdapter;
    import android.bluetooth.BluetoothDevice;
    import android.bluetooth.BluetoothServerSocket;
    import android.bluetooth.BluetoothSocket;
    import android.content.Context;
    import android.os.Bundle;
    import android.os.Handler;
    import android.os.Message;
    import android.util.Log;
    import android.widget.Toast;

    public class Piconet {


        private final static String TAG = Piconet.class.getSimpleName();

        // Name for the SDP record when creating server socket
        private static final String PICONET = "ANDROID_PICONET_BLUETOOTH";

        private final BluetoothAdapter mBluetoothAdapter;

        // String: device address
        // BluetoothSocket: socket that represent a bluetooth connection
        private HashMap<String, BluetoothSocket> mBtSockets;

        // String: device address
        // Thread: thread for connection
        private HashMap<String, Thread> mBtConnectionThreads;

        private ArrayList<UUID> mUuidList;

        private ArrayList<String> mBtDeviceAddresses;

        private Context context;


        private Handler handler = new Handler() {
            public void handleMessage(Message msg) {
                switch (msg.what) {
                    case 1:
                        Toast.makeText(context, msg.getData().getString("msg"), Toast.LENGTH_SHORT).show();
                        break;
                    default:
                        break;
                }
            };
        };

        public Piconet(Context context) {
            this.context = context;

            mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();

            mBtSockets = new HashMap<String, BluetoothSocket>();
            mBtConnectionThreads = new HashMap<String, Thread>();
            mUuidList = new ArrayList<UUID>();
            mBtDeviceAddresses = new ArrayList<String>();

            // Allow up to 7 devices to connect to the server
            mUuidList.add(UUID.fromString("a60f35f0-b93a-11de-8a39-08002009c666"));
            mUuidList.add(UUID.fromString("54d1cc90-1169-11e2-892e-0800200c9a66"));
            mUuidList.add(UUID.fromString("6acffcb0-1169-11e2-892e-0800200c9a66"));
            mUuidList.add(UUID.fromString("7b977d20-1169-11e2-892e-0800200c9a66"));
            mUuidList.add(UUID.fromString("815473d0-1169-11e2-892e-0800200c9a66"));
            mUuidList.add(UUID.fromString("503c7434-bc23-11de-8a39-0800200c9a66"));
            mUuidList.add(UUID.fromString("503c7435-bc23-11de-8a39-0800200c9a66"));

            Thread connectionProvider = new Thread(new ConnectionProvider());
            connectionProvider.start();

        }



        public void startPiconet() {
            Log.d(TAG, " -- Looking devices -- ");
            // The devices must be already paired
            Set<BluetoothDevice> pairedDevices = mBluetoothAdapter
                    .getBondedDevices();
            if (pairedDevices.size() > 0) {
                for (BluetoothDevice device : pairedDevices) {
                    // X , Y and Z are the Bluetooth name (ID) for each device you want to connect to
                    if (device != null && (device.getName().equalsIgnoreCase("X") || device.getName().equalsIgnoreCase("Y")
                            || device.getName().equalsIgnoreCase("Z") || device.getName().equalsIgnoreCase("M"))) {
                        Log.d(TAG, " -- Device " + device.getName() + " found --");
                        BluetoothDevice remoteDevice = mBluetoothAdapter
                                .getRemoteDevice(device.getAddress());
                        connect(remoteDevice);
                    }
                }
            } else {
                Toast.makeText(context, "No paired devices", Toast.LENGTH_SHORT).show();
            }
        }

        private class ConnectionProvider implements Runnable {
            @Override
            public void run() {
                try {
                    for (int i=0; i<mUuidList.size(); i++) {
                        BluetoothServerSocket myServerSocket = mBluetoothAdapter
                                .listenUsingRfcommWithServiceRecord(PICONET, mUuidList.get(i));
                        Log.d(TAG, " ** Opened connection for uuid " + i + " ** ");

                        // This is a blocking call and will only return on a
                        // successful connection or an exception
                        Log.d(TAG, " ** Waiting connection for socket " + i + " ** ");
                        BluetoothSocket myBTsocket = myServerSocket.accept();
                        Log.d(TAG, " ** Socket accept for uuid " + i + " ** ");
                        try {
                            // Close the socket now that the
                            // connection has been made.
                            myServerSocket.close();
                        } catch (IOException e) {
                            Log.e(TAG, " ** IOException when trying to close serverSocket ** ");
                        }

                        if (myBTsocket != null) {
                            String address = myBTsocket.getRemoteDevice().getAddress();

                            mBtSockets.put(address, myBTsocket);
                            mBtDeviceAddresses.add(address);

                            Thread mBtConnectionThread = new Thread(new BluetoohConnection(myBTsocket));
                            mBtConnectionThread.start();

                            Log.i(TAG," ** Adding " + address + " in mBtDeviceAddresses ** ");
                            mBtConnectionThreads.put(address, mBtConnectionThread);
                        } else {
                            Log.e(TAG, " ** Can't establish connection ** ");
                        }
                    }
                } catch (IOException e) {
                    Log.e(TAG, " ** IOException in ConnectionService:ConnectionProvider ** ", e);
                }
            }
        }

        private class BluetoohConnection implements Runnable {
            private String address;

            private final InputStream mmInStream;

            public BluetoohConnection(BluetoothSocket btSocket) {

                InputStream tmpIn = null;

                try {
                    tmpIn = new DataInputStream(btSocket.getInputStream());
                } catch (IOException e) {
                    Log.e(TAG, " ** IOException on create InputStream object ** ", e);
                }
                mmInStream = tmpIn;
            }
            @Override
            public void run() {
                byte[] buffer = new byte[1];
                String message = "";
                while (true) {

                    try {
                        int readByte = mmInStream.read();
                        if (readByte == -1) {
                            Log.e(TAG, "Discarting message: " + message);
                            message = "";
                            continue;
                        }
                        buffer[0] = (byte) readByte;

                        if (readByte == 0) { // see terminateFlag on write method
                            onReceive(message);
                            message = "";
                        } else { // a message has been recieved
                            message += new String(buffer, 0, 1);
                        }
                    } catch (IOException e) {
                        Log.e(TAG, " ** disconnected ** ", e);
                    }

                    mBtDeviceAddresses.remove(address);
                    mBtSockets.remove(address);
                    mBtConnectionThreads.remove(address);
                }
            }
        }

        /**
         * @param receiveMessage
         */
        private void onReceive(String receiveMessage) {
            if (receiveMessage != null && receiveMessage.length() > 0) {
                Log.i(TAG, " $$$$ " + receiveMessage + " $$$$ ");
                Bundle bundle = new Bundle();
                bundle.putString("msg", receiveMessage);
                Message message = new Message();
                message.what = 1;
                message.setData(bundle);
                handler.sendMessage(message);
            }
        }

        /**
         * @param device
         * @param uuidToTry
         * @return
         */
        private BluetoothSocket getConnectedSocket(BluetoothDevice device, UUID uuidToTry) {
            BluetoothSocket myBtSocket;
            try {
                myBtSocket = device.createRfcommSocketToServiceRecord(uuidToTry);
                myBtSocket.connect();
                return myBtSocket;
            } catch (IOException e) {
                Log.e(TAG, "IOException in getConnectedSocket", e);
            }
            return null;
        }

        private void connect(BluetoothDevice device) {
            BluetoothSocket myBtSocket = null;
            String address = device.getAddress();
            BluetoothDevice remoteDevice = mBluetoothAdapter.getRemoteDevice(address);
            // Try to get connection through all uuids available
            for (int i = 0; i < mUuidList.size() && myBtSocket == null; i++) {
                // Try to get the socket 2 times for each uuid of the list
                for (int j = 0; j < 2 && myBtSocket == null; j++) {
                    Log.d(TAG, " ** Trying connection..." + j + " with " + device.getName() + ", uuid " + i + "...** ");
                    myBtSocket = getConnectedSocket(remoteDevice, mUuidList.get(i));
                    if (myBtSocket == null) {
                        try {
                            Thread.sleep(200);
                        } catch (InterruptedException e) {
                            Log.e(TAG, "InterruptedException in connect", e);
                        }
                    }
                }
            }
            if (myBtSocket == null) {
                Log.e(TAG, " ** Could not connect ** ");
                return;
            }
            Log.d(TAG, " ** Connection established with " + device.getName() +"! ** ");
            mBtSockets.put(address, myBtSocket);
            mBtDeviceAddresses.add(address);
            Thread mBluetoohConnectionThread = new Thread(new BluetoohConnection(myBtSocket));
            mBluetoohConnectionThread.start();
            mBtConnectionThreads.put(address, mBluetoohConnectionThread);

        }

        public void bluetoothBroadcastMessage(String message) {
            //send message to all except Id
            for (int i = 0; i < mBtDeviceAddresses.size(); i++) {
                sendMessage(mBtDeviceAddresses.get(i), message);
            }
        }

        private void sendMessage(String destination, String message) {
            BluetoothSocket myBsock = mBtSockets.get(destination);
            if (myBsock != null) {
                try {
                    OutputStream outStream = myBsock.getOutputStream();
                    final int pieceSize = 16;
                    for (int i = 0; i < message.length(); i += pieceSize) {
                        byte[] send = message.substring(i,
                                Math.min(message.length(), i + pieceSize)).getBytes();
                        outStream.write(send);
                    }
                    // we put at the end of message a character to sinalize that message
                    // was finished
                    byte[] terminateFlag = new byte[1];
                    terminateFlag[0] = 0; // ascii table value NULL (code 0)
                    outStream.write(new byte[1]);
                } catch (IOException e) {
                    Log.d(TAG, "line 278", e);
                }
            }
        }

    }

Your main activity should be as follow :

package com.example.gaby.coordinatorv1;

import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;

public class MainActivity extends Activity {

    private Button discoveryButton;
    private Button messageButton;

    private Piconet piconet;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        piconet = new Piconet(getApplicationContext());

        messageButton = (Button) findViewById(R.id.messageButton);
        messageButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                piconet.bluetoothBroadcastMessage("Hello World---*Gaby Bou Tayeh*");
            }
        });

        discoveryButton = (Button) findViewById(R.id.discoveryButton);
        discoveryButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                piconet.startPiconet();
            }
        });

    }

}

And here's the XML Layout :

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity" >

<Button
    android:id="@+id/discoveryButton"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="Discover"
    />

<Button
    android:id="@+id/messageButton"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="Send message"
    />

Do not forget to add the following permissions to your Manifest File :

    <uses-permission android:name="android.permission.BLUETOOTH" />
<uses-permission android:name="android.permission.BLUETOOTH_ADMIN" />

R: Break for loop

your break statement should break out of the for (in in 1:n).

Personally I am always wary with break statements and double check it by printing to the console to double check that I am in fact breaking out of the right loop. So before you test add the following statement, which will let you know if you break before it reaches the end. However, I have no idea how you are handling the variable n so I don't know if it would be helpful to you. Make a n some test value where you know before hand if it is supposed to break out or not before reaching n.

for (in in 1:n)
{
    if (in == n)         #add this statement
    {
        "sorry but the loop did not break"
    }

    id_novo <- new_table_df$ID[in]
    if(id_velho==id_novo)
    {
        break
    }
    else if(in == n)
    {
        sold_df <- rbind(sold_df,old_table_df[out,])
    }
}

Multiline text in JLabel

You can do it by putting HTML in the code, so:

JFrame frame = new JFrame();
frame.setLayout(new GridLayout());
JLabel label = new JLabel("<html>First line<br>Second line</html>");
frame.add(label);
frame.pack();
frame.setVisible(true);

Loading all images using imread from a given folder

you can use glob function to do this. see the example

import cv2
import glob
for img in glob.glob("path/to/folder/*.png"):
    cv_img = cv2.imread(img)

How to create a scrollable Div Tag Vertically?

Well, your code worked for me (running Chrome 5.0.307.9 and Firefox 3.5.8 on Ubuntu 9.10), though I switched

overflow-y: scroll;

to

overflow-y: auto;

Demo page over at: http://davidrhysthomas.co.uk/so/tableDiv.html.

xhtml below:

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">

<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">

<head>
    <META http-equiv="Content-Type" content="text/html; charset=UTF-8">

    <title>Div in table</title>
    <link rel="stylesheet" type="text/css" href="css/stylesheet.css" />

        <style type="text/css" media="all">

        th      {border-bottom: 2px solid #ccc; }

        th,td       {padding: 0.5em 1em; 
                margin: 0;
                border-collapse: collapse;
                }

        tr td:first-child
                {border-right: 2px solid #ccc; } 

        td > div    {width: 249px;
                height: 299px;
                background-color:Gray;
                overflow-y: auto;
                max-width:230px;
                max-height:100px;
                }
        </style>

    <script type="text/javascript" src="js/jquery.js"></script>

    <script type="text/javascript">

    </script>

</head>

<body>

<div>

    <table>

        <thead>
            <tr><th>This is column one</th><th>This is column two</th><th>This is column three</th>
        </thead>



        <tbody>
            <tr><td>This is row one</td><td>data point 2.1</td><td>data point 3.1</td>
            <tr><td>This is row two</td><td>data point 2.2</td><td>data point 3.2</td>
            <tr><td>This is row three</td><td>data point 2.3</td><td>data point 3.3</td>
            <tr><td>This is row four</td><td><div><p>Lorem ipsum dolor sit amet, consectetur adipiscing elit. Vestibulum ultricies mattis dolor. Class aptent taciti sociosqu ad litora torquent per conubia nostra, per inceptos himenaeos. Vestibulum a accumsan purus. Vivamus semper tempus nisi et convallis. Aliquam pretium rutrum lacus sed auctor. Phasellus viverra elit vel neque lacinia ut dictum mauris aliquet. Etiam elementum iaculis lectus, laoreet tempor ligula aliquet non. Mauris ornare adipiscing feugiat. Vivamus condimentum luctus tortor venenatis fermentum. Maecenas eu risus nec leo vehicula mattis. In nisi nibh, fermentum vitae tincidunt non, mattis eu metus. Cum sociis natoque penatibus et magnis dis parturient montes, nascetur ridiculus mus. Nunc vel est purus. Ut accumsan, elit non lacinia porta, nibh magna pretium ligula, sed iaculis metus tortor aliquam urna. Duis commodo tincidunt aliquam. Maecenas in augue ut ligula sodales elementum quis vitae risus. Vivamus mollis blandit magna, eu fringilla velit auctor sed.</p></div></td><td>data point 3.4</td>
            <tr><td>This is row five</td><td>data point 2.5</td><td>data point 3.5</td>
            <tr><td>This is row six</td><td>data point 2.6</td><td>data point 3.6</td>
            <tr><td>This is row seven</td><td>data point 2.7</td><td>data point 3.7</td>
        </body>



    </table>

</div>

</body>

</html>

C++ cast to derived class

First of all - prerequisite for downcast is that object you are casting is of the type you are casting to. Casting with dynamic_cast will check this condition in runtime (provided that casted object has some virtual functions) and throw bad_cast or return NULL pointer on failure. Compile-time casts will not check anything and will just lead tu undefined behaviour if this prerequisite does not hold.
Now analyzing your code:

DerivedType m_derivedType = m_baseType;

Here there is no casting. You are creating a new object of type DerivedType and try to initialize it with value of m_baseType variable.

Next line is not much better:

DerivedType m_derivedType = (DerivedType)m_baseType;

Here you are creating a temporary of DerivedType type initialized with m_baseType value.

The last line

DerivedType * m_derivedType = (DerivedType*) & m_baseType;

should compile provided that BaseType is a direct or indirect public base class of DerivedType. It has two flaws anyway:

  1. You use deprecated C-style cast. The proper way for such casts is
    static_cast<DerivedType *>(&m_baseType)
  2. The actual type of casted object is not of DerivedType (as it was defined as BaseType m_baseType; so any use of m_derivedType pointer will result in undefined behaviour.

How to locate and insert a value in a text box (input) using Python Selenium?

Assuming your page is available under "http://example.com"

from selenium import webdriver
from selenium.webdriver.common.keys import Keys

driver = webdriver.Firefox()
driver.get("http://example.com")

Select element by id:

inputElement = driver.find_element_by_id("a1")
inputElement.send_keys('1')

Now you can simulate hitting ENTER:

inputElement.send_keys(Keys.ENTER)

or if it is a form you can submit:

inputElement.submit() 

Android ListView headers

You probably are looking for an ExpandableListView which has headers (groups) to separate items (childs).

Nice tutorial on the subject: here.

Nested Recycler view height doesn't wrap its content

@user2302510 solution works not as good as you may expected. Full workaround for both orientations and dynamically data changes is:

public class MyLinearLayoutManager extends LinearLayoutManager {

    public MyLinearLayoutManager(Context context, int orientation, boolean reverseLayout)    {
        super(context, orientation, reverseLayout);
    }

    private int[] mMeasuredDimension = new int[2];

    @Override
    public void onMeasure(RecyclerView.Recycler recycler, RecyclerView.State state,
                          int widthSpec, int heightSpec) {
        final int widthMode = View.MeasureSpec.getMode(widthSpec);
        final int heightMode = View.MeasureSpec.getMode(heightSpec);
        final int widthSize = View.MeasureSpec.getSize(widthSpec);
        final int heightSize = View.MeasureSpec.getSize(heightSpec);
        int width = 0;
        int height = 0;
        for (int i = 0; i < getItemCount(); i++) {
            measureScrapChild(recycler, i,
                    View.MeasureSpec.makeMeasureSpec(i, View.MeasureSpec.UNSPECIFIED),
                    View.MeasureSpec.makeMeasureSpec(i, View.MeasureSpec.UNSPECIFIED),
                    mMeasuredDimension);

            if (getOrientation() == HORIZONTAL) {
                width = width + mMeasuredDimension[0];
                if (i == 0) {
                    height = mMeasuredDimension[1];
                }
            } else {
                height = height + mMeasuredDimension[1];
                if (i == 0) {
                    width = mMeasuredDimension[0];
                }
            }
        }
        switch (widthMode) {
            case View.MeasureSpec.EXACTLY:
                width = widthSize;
            case View.MeasureSpec.AT_MOST:
            case View.MeasureSpec.UNSPECIFIED:
        }

        switch (heightMode) {
            case View.MeasureSpec.EXACTLY:
                height = heightSize;
            case View.MeasureSpec.AT_MOST:
            case View.MeasureSpec.UNSPECIFIED:
        }

        setMeasuredDimension(width, height);
    }

    private void measureScrapChild(RecyclerView.Recycler recycler, int position, int widthSpec,
                                   int heightSpec, int[] measuredDimension) {
        View view = recycler.getViewForPosition(position);
        if (view != null) {
            RecyclerView.LayoutParams p = (RecyclerView.LayoutParams) view.getLayoutParams();
            int childWidthSpec = ViewGroup.getChildMeasureSpec(widthSpec,
                    getPaddingLeft() + getPaddingRight(), p.width);
            int childHeightSpec = ViewGroup.getChildMeasureSpec(heightSpec,
                    getPaddingTop() + getPaddingBottom(), p.height);
            view.measure(childWidthSpec, childHeightSpec);
            measuredDimension[0] = view.getMeasuredWidth() + p.leftMargin + p.rightMargin;
            measuredDimension[1] = view.getMeasuredHeight() + p.bottomMargin + p.topMargin;
            recycler.recycleView(view);
        }
    }
}

ASP.NET MVC Dropdown List From SelectList

Just try this in razor

@{
    var selectList = new SelectList(
        new List<SelectListItem>
        {
            new SelectListItem {Text = "Google", Value = "Google"},
            new SelectListItem {Text = "Other", Value = "Other"},
        }, "Value", "Text");
}

and then

@Html.DropDownListFor(m => m.YourFieldName, selectList, "Default label", new { @class = "css-class" })

or

@Html.DropDownList("ddlDropDownList", selectList, "Default label", new { @class = "css-class" })

Spring Boot and multiple external configuration files

Spring boot 1.X and Spring Boot 2.X don't provide the same options and behavior about the Externalized Configuration.

The very good answer of M. Deinum refers to Spring Boot 1 specifities.
I will update for Spring Boot 2 here.

Environment properties sources and order

Spring Boot 2 uses a very particular PropertySource order that is designed to allow sensible overriding of values. Properties are considered in the following order:

  • Devtools global settings properties on your home directory (~/.spring-boot-devtools.properties when devtools is active).

  • @TestPropertySource annotations on your tests.

  • @SpringBootTest#properties annotation attribute on your tests. Command line arguments.

  • Properties from SPRING_APPLICATION_JSON (inline JSON embedded in an environment variable or system property).

  • ServletConfig init parameters.

  • ServletContext init parameters.

  • JNDI attributes from java:comp/env.

  • Java System properties (System.getProperties()).

  • OS environment variables.

  • A RandomValuePropertySource that has properties only in random.*.

  • Profile-specific application properties outside of your packaged jar (application-{profile}.properties and YAML variants).

  • Profile-specific application properties packaged inside your jar (application-{profile}.properties and YAML variants).

  • Application properties outside of your packaged jar (application.properties and YAML variants).

  • Application properties packaged inside your jar (application.properties and YAML variants).

  • @PropertySource annotations on your @Configuration classes. Default properties (specified by setting SpringApplication.setDefaultProperties).

To specify external properties files these options should interest you :

  • Profile-specific application properties outside of your packaged jar (application-{profile}.properties and YAML variants).

  • Application properties outside of your packaged jar (application.properties and YAML variants).

  • @PropertySource annotations on your @Configuration classes. Default properties (specified by setting SpringApplication.setDefaultProperties).

You can use only one of these 3 options or combine them according to your requirements.
For example for very simple cases using only profile-specific properties is enough but in other cases you may want to use both profile-specific properties, default properties and @PropertySource.

Default locations for application.properties files

About application.properties files (and variant), by default Spring loads them and add their properties in the environment from these in the following order :

  • A /config subdirectory of the current directory

  • The current directory

  • A classpath /config package

  • The classpath root

The higher priorities are so literally :
classpath:/,classpath:/config/,file:./,file:./config/.

How to use properties files with specific names ?

The default locations are not always enough : the default locations like the default filename (application.properties) may not suit. Besides, as in the OP question you may need to specify multiple configuration files other than application.properties (and variant).
So spring.config.name will not be enough.

In this case you should provide an explicit location by using the spring.config.location environment property (which is a comma-separated list of directory locations or file paths).
To be free about the filenames pattern favor the list of file paths over the list of directories.
For example do like that :

java -jar myproject.jar --spring.config.location=classpath:/default.properties,classpath:/override.properties

That way is the most verbose that just specifying the folder but it is also the way to specify very finely our configuration files and to document clearly the properties effectively used.

spring.config.location now replaces default locations instead of adding to them

With Spring Boot 1, the spring.config.location argument adds specified locations in the Spring environment.
But from Spring Boot 2, spring.config.location replaces the default locations used by Spring by the specified locations in the Spring environment as stated in the documentation.

When custom config locations are configured by using spring.config.location, they replace the default locations. For example, if spring.config.location is configured with the value classpath:/custom-config/,file:./custom-config/, the search order becomes the following:

  1. file:./custom-config/

  2. classpath:custom-config/

spring.config.location is now a way to make sure that any application.properties file has to be explicitly specified.
For uber JARs that are not supposed to package application.properties files, that is rather nice.

To keep the old behavior of spring.config.location while using Spring Boot 2 you can use the new spring.config.additional-location property instead of spring.config.location that still adds the locations as stated by the documentation :

Alternatively, when custom config locations are configured by using spring.config.additional-location, they are used in addition to the default locations.


In practice

So supposing that as in the OP question, you have 2 external properties file to specify and 1 properties file included in the uber jar.

To use only configuration files you specified :

-Dspring.config.location=classpath:/job1.properties,classpath:/job2.properties,classpath:/applications.properties   

To add configuration files to these in the default locations :

-Dspring.config.additional-location=classpath:/job1.properties,classpath:/job2.properties

classpath:/applications.properties is in the last example not required as the default locations have that and that default locations are here not overwritten but extended.

setting y-axis limit in matplotlib

You can instantiate an object from matplotlib.pyplot.axes and call the set_ylim() on it. It would be something like this:

import matplotlib.pyplot as plt
axes = plt.axes()
axes.set_ylim([0, 1])

CSS selector based on element text?

Not with CSS directly, you could set CSS properties via JavaScript based on the internal contents but in the end you would still need to be operating in the definitions of CSS.

SQL select join: is it possible to prefix all columns as 'prefix.*'?

There are two ways I can think of to make this happen in a reusable way. One is to rename all of your columns with a prefix for the table they have come from. I have seen this many times, but I really don't like it. I find that it's redundant, causes a lot of typing, and you can always use aliases when you need to cover the case of a column name having an unclear origin.

The other way, which I would recommend you do in your situation if you are committed to seeing this through, is to create views for each table that alias the table names. Then you join against those views, rather than the tables. That way, you are free to use * if you wish, free to use the original tables with original column names if you wish, and it also makes writing any subsequent queries easier because you have already done the renaming work in the views.

Finally, I am not clear why you need to know which table each of the columns came from. Does this matter? Ultimately what matters is the data they contain. Whether UserID came from the User table or the UserQuestion table doesn't really matter. It matters, of course, when you need to update it, but at that point you should already know your schema well enough to determine that.

What exactly does Perl's "bless" do?

In general, bless associates an object with a class.

package MyClass;
my $object = { };
bless $object, "MyClass";

Now when you invoke a method on $object, Perl know which package to search for the method.

If the second argument is omitted, as in your example, the current package/class is used.

For the sake of clarity, your example might be written as follows:

sub new { 
  my $class = shift; 
  my $self = { }; 
  bless $self, $class; 
} 

EDIT: See kixx's good answer for a little more detail.

Change One Cell's Data in mysql

UPDATE TABLE <tablename> SET <COLUMN=VALUE> WHERE <CONDITION>

Example:

UPDATE TABLE teacher SET teacher_name='NSP' WHERE teacher_id='1'

How to add items to array in nodejs

Check out Javascript's Array API for details on the exact syntax for Array methods. Modifying your code to use the correct syntax would be:

var array = [];
calendars.forEach(function(item) {
    array.push(item.id);
});

console.log(array);

You can also use the map() method to generate an Array filled with the results of calling the specified function on each element. Something like:

var array = calendars.map(function(item) {
    return item.id;
});

console.log(array);

And, since ECMAScript 2015 has been released, you may start seeing examples using let or const instead of var and the => syntax for creating functions. The following is equivalent to the previous example (except it may not be supported in older node versions):

let array = calendars.map(item => item.id);
console.log(array);

Ajax using https on an http page

Try JSONP.

most JS libraries make it just as easy as other AJAX calls, but internally use an iframe to do the query.

if you're not using JSON for your payload, then you'll have to roll your own mechanism around the iframe.

personally, i'd just redirect form the http:// page to the https:// one

How to get Django and ReactJS to work together?

The accepted answer lead me to believe that decoupling Django backend and React Frontend is the right way to go no matter what. In fact there are approaches in which React and Django are coupled, which may be better suited in particular situations.

This tutorial well explains this. In particular:

I see the following patterns (which are common to almost every web framework):

-React in its own “frontend” Django app: load a single HTML template and let React manage the frontend (difficulty: medium)

-Django REST as a standalone API + React as a standalone SPA (difficulty: hard, it involves JWT for authentication)

-Mix and match: mini React apps inside Django templates (difficulty: simple)

What can be the reasons of connection refused errors?

There could be many reasons, but the most common are:

  1. The port is not open on the destination machine.

  2. The port is open on the destination machine, but its backlog of pending connections is full.

  3. A firewall between the client and server is blocking access (also check local firewalls).

After checking for firewalls and that the port is open, use telnet to connect to the ip/port to test connectivity. This removes any potential issues from your application.

How to update and delete a cookie?

http://www.quirksmode.org/js/cookies.html

function createCookie(name,value,days) {
    if (days) {
        var date = new Date();
        date.setTime(date.getTime()+(days*24*60*60*1000));
        var expires = "; expires="+date.toGMTString();
    }
    else var expires = "";
    document.cookie = name+"="+value+expires+"; path=/";
}

function readCookie(name) {
    var nameEQ = name + "=";
    var ca = document.cookie.split(';');
    for(var i=0;i < ca.length;i++) {
        var c = ca[i];
        while (c.charAt(0)==' ') c = c.substring(1,c.length);
        if (c.indexOf(nameEQ) == 0) return c.substring(nameEQ.length,c.length);
    }
    return null;
}

function eraseCookie(name) {
    createCookie(name,"",-1);
}

How do I use popover from Twitter Bootstrap to display an image?

Very simple :)

<a href="#" id="blob" class="btn large primary" rel="popover">hover for popover</a>

var img = '<img src="https://si0.twimg.com/a/1339639284/images/three_circles/twitter-bird-white-on-blue.png" />';

$("#blob").popover({ title: 'Look! A bird!', content: img, html:true });

http://jsfiddle.net/weuWk/

Why does the arrow (->) operator in C exist?

I'll interpret your question as two questions: 1) why -> even exists, and 2) why . does not automatically dereference the pointer. Answers to both questions have historical roots.

Why does -> even exist?

In one of the very first versions of C language (which I will refer as CRM for "C Reference Manual", which came with 6th Edition Unix in May 1975), operator -> had very exclusive meaning, not synonymous with * and . combination

The C language described by CRM was very different from the modern C in many respects. In CRM struct members implemented the global concept of byte offset, which could be added to any address value with no type restrictions. I.e. all names of all struct members had independent global meaning (and, therefore, had to be unique). For example you could declare

struct S {
  int a;
  int b;
};

and name a would stand for offset 0, while name b would stand for offset 2 (assuming int type of size 2 and no padding). The language required all members of all structs in the translation unit either have unique names or stand for the same offset value. E.g. in the same translation unit you could additionally declare

struct X {
  int a;
  int x;
};

and that would be OK, since the name a would consistently stand for offset 0. But this additional declaration

struct Y {
  int b;
  int a;
};

would be formally invalid, since it attempted to "redefine" a as offset 2 and b as offset 0.

And this is where the -> operator comes in. Since every struct member name had its own self-sufficient global meaning, the language supported expressions like these

int i = 5;
i->b = 42;  /* Write 42 into `int` at address 7 */
100->a = 0; /* Write 0 into `int` at address 100 */

The first assignment was interpreted by the compiler as "take address 5, add offset 2 to it and assign 42 to the int value at the resultant address". I.e. the above would assign 42 to int value at address 7. Note that this use of -> did not care about the type of the expression on the left-hand side. The left hand side was interpreted as an rvalue numerical address (be it a pointer or an integer).

This sort of trickery was not possible with * and . combination. You could not do

(*i).b = 42;

since *i is already an invalid expression. The * operator, since it is separate from ., imposes more strict type requirements on its operand. To provide a capability to work around this limitation CRM introduced the -> operator, which is independent from the type of the left-hand operand.

As Keith noted in the comments, this difference between -> and *+. combination is what CRM is referring to as "relaxation of the requirement" in 7.1.8: Except for the relaxation of the requirement that E1 be of pointer type, the expression E1->MOS is exactly equivalent to (*E1).MOS

Later, in K&R C many features originally described in CRM were significantly reworked. The idea of "struct member as global offset identifier" was completely removed. And the functionality of -> operator became fully identical to the functionality of * and . combination.

Why can't . dereference the pointer automatically?

Again, in CRM version of the language the left operand of the . operator was required to be an lvalue. That was the only requirement imposed on that operand (and that's what made it different from ->, as explained above). Note that CRM did not require the left operand of . to have a struct type. It just required it to be an lvalue, any lvalue. This means that in CRM version of C you could write code like this

struct S { int a, b; };
struct T { float x, y, z; };

struct T c;
c.b = 55;

In this case the compiler would write 55 into an int value positioned at byte-offset 2 in the continuous memory block known as c, even though type struct T had no field named b. The compiler would not care about the actual type of c at all. All it cared about is that c was an lvalue: some sort of writable memory block.

Now note that if you did this

S *s;
...
s.b = 42;

the code would be considered valid (since s is also an lvalue) and the compiler would simply attempt to write data into the pointer s itself, at byte-offset 2. Needless to say, things like this could easily result in memory overrun, but the language did not concern itself with such matters.

I.e. in that version of the language your proposed idea about overloading operator . for pointer types would not work: operator . already had very specific meaning when used with pointers (with lvalue pointers or with any lvalues at all). It was very weird functionality, no doubt. But it was there at the time.

Of course, this weird functionality is not a very strong reason against introducing overloaded . operator for pointers (as you suggested) in the reworked version of C - K&R C. But it hasn't been done. Maybe at that time there was some legacy code written in CRM version of C that had to be supported.

(The URL for the 1975 C Reference Manual may not be stable. Another copy, possibly with some subtle differences, is here.)

Best practices for styling HTML emails

I find that image mapping works pretty well. If you have any headers or footers that are images make sure that you apply a bgcolor="fill in the blank" because outlook in most cases wont load the image and you will be left with a transparent header. If you at least designate a color that works with the over all feel of the email it will be less of a shock for the user. Never try and use any styling sheets. Or CSS at all! Just avoid it.

Depending if you're copying content from a word or shared google Doc be sure to (command+F) Find all the (') and (") and replace them within your editing software (especially dreemweaver) because they will show up as code and it's just not good.

ALT is your best friend. use the ALT tag to add in text to all your images. Because odds are they are not going to load right. And that ALT text is what gets people to click the (see images) button. Also define your images Width, Height and make the boarder 0 so you dont get weird lines around your image.

Consider editing all images within Photoshop with a 15px boarder on each side (make background transparent and save as a PNG 24) of image. Sometimes the email clients do not read any padding styles that you apply to the images so it avoids any weird formatting!

Also i found the line under links particularly annoying so if you apply < style="text-decoration:none; color:#whatever color you want here!" > it will remove the line and give you the desired look.

There is alot that can really mess with the over all look and feel.

javascript node.js next()

This appears to be a variable naming convention in Node.js control-flow code, where a reference to the next function to execute is given to a callback for it to kick-off when it's done.

See, for example, the code samples here:

Let's look at the example you posted:

function loadUser(req, res, next) {
  if (req.session.user_id) {
    User.findById(req.session.user_id, function(user) {
      if (user) {
        req.currentUser = user;
        return next();
      } else {
        res.redirect('/sessions/new');
      }
    });
  } else {
    res.redirect('/sessions/new');
  }
}

app.get('/documents.:format?', loadUser, function(req, res) {
  // ...
});

The loadUser function expects a function in its third argument, which is bound to the name next. This is a normal function parameter. It holds a reference to the next action to perform and is called once loadUser is done (unless a user could not be found).

There's nothing special about the name next in this example; we could have named it anything.

How to center a <p> element inside a <div> container?

on the p element, add 3 styling rules.

.myCenteredPElement{
    margin-left:  auto;
    margin-right: auto;
    text-align: center;
}

Regular Expression to match only alphabetic characters

[a-zA-Z] should do that just fine.

You can reference the cheat sheet.

Creating files and directories via Python

import os

path = chap_name

if not os.path.exists(path):
    os.makedirs(path)

filename = img_alt + '.jpg'
with open(os.path.join(path, filename), 'wb') as temp_file:
    temp_file.write(buff)

Key point is to use os.makedirs in place of os.mkdir. It is recursive, i.e. it generates all intermediate directories. See http://docs.python.org/library/os.html

Open the file in binary mode as you are storing binary (jpeg) data.

In response to Edit 2, if img_alt sometimes has '/' in it:

img_alt = os.path.basename(img_alt)

Calling virtual functions inside constructors

The vtables are created by the compiler. A class object has a pointer to its vtable. When it starts life, that vtable pointer points to the vtable of the base class. At the end of the constructor code, the compiler generates code to re-point the vtable pointer to the actual vtable for the class. This ensures that constructor code that calls virtual functions calls the base class implementations of those functions, not the override in the class.

How to change the Text color of Menu item in Android?

Thanks to max.musterman, this is the solution I got to work in level 22:

public boolean onCreateOptionsMenu(Menu menu) {
    getMenuInflater().inflate(R.menu.menu_main, menu);
    SearchManager searchManager = (SearchManager) getSystemService(Context.SEARCH_SERVICE);
    MenuItem searchMenuItem = menu.findItem(R.id.search);
    SearchView searchView = (SearchView) searchMenuItem.getActionView();
    searchView.setSearchableInfo(searchManager.getSearchableInfo(getComponentName()));
    searchView.setSubmitButtonEnabled(true);
    searchView.setOnQueryTextListener(this);
    setMenuTextColor(menu, R.id.displaySummary, R.string.show_summary);
    setMenuTextColor(menu, R.id.about, R.string.text_about);
    setMenuTextColor(menu, R.id.importExport, R.string.import_export);
    setMenuTextColor(menu, R.id.preferences, R.string.settings);
    return true;
}

private void setMenuTextColor(Menu menu, int menuResource, int menuTextResource) {
    MenuItem item = menu.findItem(menuResource);
    SpannableString s = new SpannableString(getString(menuTextResource));
    s.setSpan(new ForegroundColorSpan(Color.BLACK), 0, s.length(), 0);
    item.setTitle(s);
}

The hardcoded Color.BLACK could become an additional parameter to the setMenuTextColor method. Also, I only used this for menu items which were android:showAsAction="never".

Android Studio doesn't see device

I am using Android Studio 4.0, Android Studio said "Device was detected by ADB but not Android Studio". I tried re-enable "developer option" and "usb debug", re-plugin the usb, but no luck. I restart the Android Studio and it works.

Please try restart the Android Studio.

Hope it could save you some time.

Fix height of a table row in HTML Table

my css

TR.gray-t {background:#949494;}
h3{
    padding-top:3px;
    font:bold 12px/2px Arial;
}

my html

<TR class='gray-t'>
<TD colspan='3'><h3>KAJANG</h3>

I decrease the 2nd size in font.

padding-top is used to fix the size in IE7.

How to upload a file using Java HttpClient library working with PHP

A newer version example is here.

Below is a copy of the original code:

/*
 * ====================================================================
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Software Foundation.  For more
 * information on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
 *
 */
package org.apache.http.examples.entity.mime;

import java.io.File;

import org.apache.http.HttpEntity;
import org.apache.http.client.methods.CloseableHttpResponse;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.entity.ContentType;
import org.apache.http.entity.mime.MultipartEntityBuilder;
import org.apache.http.entity.mime.content.FileBody;
import org.apache.http.entity.mime.content.StringBody;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClients;
import org.apache.http.util.EntityUtils;

/**
 * Example how to use multipart/form encoded POST request.
 */
public class ClientMultipartFormPost {

    public static void main(String[] args) throws Exception {
        if (args.length != 1)  {
            System.out.println("File path not given");
            System.exit(1);
        }
        CloseableHttpClient httpclient = HttpClients.createDefault();
        try {
            HttpPost httppost = new HttpPost("http://localhost:8080" +
                    "/servlets-examples/servlet/RequestInfoExample");

            FileBody bin = new FileBody(new File(args[0]));
            StringBody comment = new StringBody("A binary file of some kind", ContentType.TEXT_PLAIN);

            HttpEntity reqEntity = MultipartEntityBuilder.create()
                    .addPart("bin", bin)
                    .addPart("comment", comment)
                    .build();


            httppost.setEntity(reqEntity);

            System.out.println("executing request " + httppost.getRequestLine());
            CloseableHttpResponse response = httpclient.execute(httppost);
            try {
                System.out.println("----------------------------------------");
                System.out.println(response.getStatusLine());
                HttpEntity resEntity = response.getEntity();
                if (resEntity != null) {
                    System.out.println("Response content length: " + resEntity.getContentLength());
                }
                EntityUtils.consume(resEntity);
            } finally {
                response.close();
            }
        } finally {
            httpclient.close();
        }
    }

}

websocket.send() parameter

As I understand it, you want the server be able to send messages through from client 1 to client 2. You cannot directly connect two clients because one of the two ends of a WebSocket connection needs to be a server.

This is some pseudocodish JavaScript:

Client:

var websocket = new WebSocket("server address");

websocket.onmessage = function(str) {
  console.log("Someone sent: ", str);
};

// Tell the server this is client 1 (swap for client 2 of course)
websocket.send(JSON.stringify({
  id: "client1"
}));

// Tell the server we want to send something to the other client
websocket.send(JSON.stringify({
  to: "client2",
  data: "foo"
}));

Server:

var clients = {};

server.on("data", function(client, str) {
  var obj = JSON.parse(str);

  if("id" in obj) {
    // New client, add it to the id/client object
    clients[obj.id] = client;
  } else {
    // Send data to the client requested
    clients[obj.to].send(obj.data);
  }
});

SMTPAuthenticationError when sending mail using gmail and python

Your code looks correct. Try logging in through your browser and if you are able to access your account come back and try your code again. Just make sure that you have typed your username and password correct

EDIT: Google blocks sign-in attempts from apps which do not use modern security standards (mentioned on their support page). You can however, turn on/off this safety feature by going to the link below:

Go to this link and select Turn On
https://www.google.com/settings/security/lesssecureapps

The total number of locks exceeds the lock table size

This answer below does not directly answer the OP's question. However, I'm adding this answer here because this page is the first result when you Google "The total number of locks exceeds the lock table size".


If the query you are running is parsing an entire table that spans millions of rows, you can try a while loop instead of changing limits in the configuration.

The while look will break it into pieces. Below is an example looping over an indexed column that is DATETIME.

# Drop
DROP TABLE IF EXISTS
new_table;

# Create (we will add keys later)
CREATE TABLE
new_table
(
    num INT(11),
    row_id VARCHAR(255),
    row_value VARCHAR(255),
    row_date DATETIME
);

# Change the delimimter
DELIMITER //

# Create procedure
CREATE PROCEDURE do_repeat(IN current_loop_date DATETIME)
BEGIN

    # Loops WEEK by WEEK until NOW(). Change WEEK to something shorter like DAY if you still get the lock errors like.
    WHILE current_loop_date <= NOW() DO

        # Do something
        INSERT INTO
            user_behavior_search_tagged_keyword_statistics_with_type
            (
                num,
                row_id,
                row_value,
                row_date
            )
        SELECT
            # Do something interesting here
            num,
            row_id,
            row_value,
            row_date
        FROM
            old_table
        WHERE
            row_date >= current_loop_date AND
            row_date < current_loop_date + INTERVAL 1 WEEK;

        # Increment
        SET current_loop_date = current_loop_date + INTERVAL 1 WEEK;

    END WHILE;

END//

# Run
CALL do_repeat('2017-01-01');

# Cleanup
DROP PROCEDURE IF EXISTS do_repeat//

# Change the delimimter back
DELIMITER ;

# Add keys
ALTER TABLE
    new_table
MODIFY COLUMN
    num int(11) NOT NULL,
ADD PRIMARY KEY
    (num),
ADD KEY
    row_id (row_id) USING BTREE,
ADD KEY
    row_date (row_date) USING BTREE;

You can also adapt it to loop over the "num" column if your table doesn't use a date.

Hope this helps someone!

How can I properly handle 404 in ASP.NET MVC?

Here is another method using MVC tools which you can handle requests to bad controller names, bad route names, and any other criteria you see fit inside of an Action method. Personally, I prefer to avoid as many web.config settings as possible, because they do the 302 / 200 redirect and do not support ResponseRewrite (Server.Transfer) using Razor views. I'd prefer to return a 404 with a custom error page for SEO reasons.

Some of this is new take on cottsak's technique above.

This solution also uses minimal web.config settings favoring the MVC 3 Error Filters instead.

Usage

Just throw a HttpException from an action or custom ActionFilterAttribute.

Throw New HttpException(HttpStatusCode.NotFound, "[Custom Exception Message Here]")

Step 1

Add the following setting to your web.config. This is required to use MVC's HandleErrorAttribute.

<customErrors mode="On" redirectMode="ResponseRedirect" />

Step 2

Add a custom HandleHttpErrorAttribute similar to the MVC framework's HandleErrorAttribute, except for HTTP errors:

<AttributeUsage(AttributeTargets.All, AllowMultiple:=True)>
Public Class HandleHttpErrorAttribute
    Inherits FilterAttribute
    Implements IExceptionFilter

    Private Const m_DefaultViewFormat As String = "ErrorHttp{0}"

    Private m_HttpCode As HttpStatusCode
    Private m_Master As String
    Private m_View As String

    Public Property HttpCode As HttpStatusCode
        Get
            If m_HttpCode = 0 Then
                Return HttpStatusCode.NotFound
            End If
            Return m_HttpCode
        End Get
        Set(value As HttpStatusCode)
            m_HttpCode = value
        End Set
    End Property

    Public Property Master As String
        Get
            Return If(m_Master, String.Empty)
        End Get
        Set(value As String)
            m_Master = value
        End Set
    End Property

    Public Property View As String
        Get
            If String.IsNullOrEmpty(m_View) Then
                Return String.Format(m_DefaultViewFormat, Me.HttpCode)
            End If
            Return m_View
        End Get
        Set(value As String)
            m_View = value
        End Set
    End Property

    Public Sub OnException(filterContext As System.Web.Mvc.ExceptionContext) Implements System.Web.Mvc.IExceptionFilter.OnException
        If filterContext Is Nothing Then Throw New ArgumentException("filterContext")

        If filterContext.IsChildAction Then
            Return
        End If

        If filterContext.ExceptionHandled OrElse Not filterContext.HttpContext.IsCustomErrorEnabled Then
            Return
        End If

        Dim ex As HttpException = TryCast(filterContext.Exception, HttpException)
        If ex Is Nothing OrElse ex.GetHttpCode = HttpStatusCode.InternalServerError Then
            Return
        End If

        If ex.GetHttpCode <> Me.HttpCode Then
            Return
        End If

        Dim controllerName As String = filterContext.RouteData.Values("controller")
        Dim actionName As String = filterContext.RouteData.Values("action")
        Dim model As New HandleErrorInfo(filterContext.Exception, controllerName, actionName)

        filterContext.Result = New ViewResult With {
            .ViewName = Me.View,
            .MasterName = Me.Master,
            .ViewData = New ViewDataDictionary(Of HandleErrorInfo)(model),
            .TempData = filterContext.Controller.TempData
        }
        filterContext.ExceptionHandled = True
        filterContext.HttpContext.Response.Clear()
        filterContext.HttpContext.Response.StatusCode = Me.HttpCode
        filterContext.HttpContext.Response.TrySkipIisCustomErrors = True
    End Sub
End Class

Step 3

Add Filters to the GlobalFilterCollection (GlobalFilters.Filters) in Global.asax. This example will route all InternalServerError (500) errors to the Error shared view (Views/Shared/Error.vbhtml). NotFound (404) errors will be sent to ErrorHttp404.vbhtml in the shared views as well. I've added a 401 error here to show you how this can be extended for additional HTTP error codes. Note that these must be shared views, and they all use the System.Web.Mvc.HandleErrorInfo object as a the model.

filters.Add(New HandleHttpErrorAttribute With {.View = "ErrorHttp401", .HttpCode = HttpStatusCode.Unauthorized})
filters.Add(New HandleHttpErrorAttribute With {.View = "ErrorHttp404", .HttpCode = HttpStatusCode.NotFound})
filters.Add(New HandleErrorAttribute With {.View = "Error"})

Step 4

Create a base controller class and inherit from it in your controllers. This step allows us to handle unknown action names and raise the HTTP 404 error to our HandleHttpErrorAttribute.

Public Class BaseController
    Inherits System.Web.Mvc.Controller

    Protected Overrides Sub HandleUnknownAction(actionName As String)
        Me.ActionInvoker.InvokeAction(Me.ControllerContext, "Unknown")
    End Sub

    Public Function Unknown() As ActionResult
        Throw New HttpException(HttpStatusCode.NotFound, "The specified controller or action does not exist.")
        Return New EmptyResult
    End Function
End Class

Step 5

Create a ControllerFactory override, and override it in your Global.asax file in Application_Start. This step allows us to raise the HTTP 404 exception when an invalid controller name has been specified.

Public Class MyControllerFactory
    Inherits DefaultControllerFactory

    Protected Overrides Function GetControllerInstance(requestContext As System.Web.Routing.RequestContext, controllerType As System.Type) As System.Web.Mvc.IController
        Try
            Return MyBase.GetControllerInstance(requestContext, controllerType)
        Catch ex As HttpException
            Return DependencyResolver.Current.GetService(Of BaseController)()
        End Try
    End Function
End Class

'In Global.asax.vb Application_Start:

controllerBuilder.Current.SetControllerFactory(New MyControllerFactory)

Step 6

Include a special route in your RoutTable.Routes for the BaseController Unknown action. This will help us raise a 404 in the case where a user accesses an unknown controller, or unknown action.

'BaseController
routes.MapRoute( _
    "Unknown", "BaseController/{action}/{id}", _
    New With {.controller = "BaseController", .action = "Unknown", .id = UrlParameter.Optional} _
)

Summary

This example demonstrated how one can use the MVC framework to return 404 Http Error Codes to the browser without a redirect using filter attributes and shared error views. It also demonstrates showing the same custom error page when invalid controller names and action names are specified.

I'll add a screenshot of an invalid controller name, action name, and a custom 404 raised from the Home/TriggerNotFound action if I get enough votes to post one =). Fiddler returns a 404 message when I access the following URLs using this solution:

/InvalidController
/Home/InvalidRoute
/InvalidController/InvalidRoute
/Home/TriggerNotFound

cottsak's post above and these articles were good references.

Reading an image file into bitmap from sdcard, why am I getting a NullPointerException?

It works:

Bitmap bitmap = BitmapFactory.decodeFile(filePath);

How to create a popup windows in javafx

You can either create a new Stage, add your controls into it or if you require the POPUP as Dialog box, then you may consider using DialogsFX or ControlsFX(Requires JavaFX8)

For creating a new Stage, you can use the following snippet

@Override
public void start(final Stage primaryStage) {
    Button btn = new Button();
    btn.setText("Open Dialog");
    btn.setOnAction(
        new EventHandler<ActionEvent>() {
            @Override
            public void handle(ActionEvent event) {
                final Stage dialog = new Stage();
                dialog.initModality(Modality.APPLICATION_MODAL);
                dialog.initOwner(primaryStage);
                VBox dialogVbox = new VBox(20);
                dialogVbox.getChildren().add(new Text("This is a Dialog"));
                Scene dialogScene = new Scene(dialogVbox, 300, 200);
                dialog.setScene(dialogScene);
                dialog.show();
            }
         });
    }

If you don't want it to be modal (block other windows), use:

dialog.initModality(Modality.NONE);

Error HRESULT E_FAIL has been returned from a call to a COM component VS2012 when debugging

I got this error when trying to install a nuget package that I had previously downloaded and installed in another project.

Clicking Clear all NuGet Cache(s) under Tools > Options > NuGet Package Manager solved this for me

best way to get the key of a key/value javascript object

A one liner for you:

const OBJECT = {
    'key1': 'value1',
    'key2': 'value2',
    'key3': 'value3',
    'key4': 'value4'
};

const value = 'value2';

const key = Object.keys(OBJECT)[Object.values(OBJECT).indexOf(value)];

window.console.log(key); // = key2

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

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

In short:

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

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

Above may emit lines such as

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

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

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

Remove Blank option from Select Option with AngularJS

For me the answer to this question was using <option value="" selected hidden /> as it was proposed by @RedSparkle plus adding ng-if="false" to work in IE.

So my full option is (has differences with what I wrote before, but this does not matter because of ng-if):

<option value="" ng-if="false" disabled hidden></option>

importing jar libraries into android-studio

Running Android Studio 0.4.0 Solved the problem of importing jar by

Project Structure > Modules > Dependencies > Add Files
Browse to the location of jar file and select it

For those like manual editing Open app/build.gradle

dependencies {
    compile files('src/main/libs/xxx.jar')
}

php error: Class 'Imagick' not found

Debian 9

I just did the following and everything else needed got automatically installed as well.

sudo apt-get -y -f install php-imagick
sudo /etc/init.d/apache2 restart

Unable to establish SSL connection, how do I fix my SSL cert?

In my case I had not enabled the site 'default-ssl'. Only '000-default' was listed in the /etc/apache2/sites-enabled folder.

Enable SSL site on Ubuntu 14 LTS, Apache 2.4.7:

a2ensite default-ssl
service apache2 reload

Tools to generate database tables diagram with Postgresql?

PostgreSQL Autodoc has worked well for me. It is a simple command line tool. From the web page:

This is a utility which will run through PostgreSQL system tables and returns HTML, Dot, Dia and DocBook XML which describes the database.

How to convert/parse from String to char in java?

If the string is 1 character long, just take that character. If the string is not 1 character long, it cannot be parsed into a character.

file_get_contents(): SSL operation failed with code 1, Failed to enable crypto

I fixed this by making sure that that OpenSSL was installed on my machine and then adding this to my php.ini:

openssl.cafile=/usr/local/etc/openssl/cert.pem

Alter user defined type in SQL Server

I ran into this issue with custom types in stored procedures, and solved it with the script below. I didn't fully understand the scripts above, and I follow the rule of "if you don't know what it does, don't do it".

In a nutshell, I rename the old type, and create a new one with the original type name. Then, I tell SQL Server to refresh its details about each stored procedure using the custom type. You have to do this, as everything is still "compiled" with reference to the old type, even with the rename. In this case, the type I needed to change was "PrizeType". I hope this helps. I'm looking for feedback, too, so I learn :)

Note that you may need to go to Programmability > Types > [Appropriate User Type] and delete the object. I found that DROP TYPE doesn't appear to always drop the type even after using the statement.

/* Rename the UDDT you want to replace to another name */ 
exec sp_rename 'PrizeType', 'PrizeTypeOld', 'USERDATATYPE';

/* Add the updated UDDT with the new definition */ 
CREATE TYPE [dbo].[PrizeType] AS TABLE(
    [Type] [nvarchar](50) NOT NULL,
    [Description] [nvarchar](max) NOT NULL,
    [ImageUrl] [varchar](max) NULL
);

/* We need to force stored procedures to refresh with the new type... let's take care of that. */
/* Get a cursor over a list of all the stored procedures that may use this and refresh them */
declare sprocs cursor
  local static read_only forward_only
for
    select specific_name from information_schema.routines where routine_type = 'PROCEDURE'

declare @sprocName varchar(max)

open sprocs
fetch next from sprocs into @sprocName
while @@fetch_status = 0
begin
    print 'Updating ' + @sprocName;
    exec sp_refreshsqlmodule @sprocName
    fetch next from sprocs into @sprocName
end
close sprocs
deallocate sprocs

/* Drop the old type, now that everything's been re-assigned; must do this last */
drop type PrizeTypeOld;

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)

Using NSLog for debugging

Use NSLog() like this:

NSLog(@"The code runs through here!");

Or like this - with placeholders:

float aFloat = 5.34245;
NSLog(@"This is my float: %f \n\nAnd here again: %.2f", aFloat, aFloat);

In NSLog() you can use it like + (id)stringWithFormat:(NSString *)format, ...

float aFloat = 5.34245;
NSString *aString = [NSString stringWithFormat:@"This is my float: %f \n\nAnd here again: %.2f", aFloat, aFloat];

You can add other placeholders, too:

float aFloat = 5.34245;
int aInteger = 3;
NSString *aString = @"A string";
NSLog(@"This is my float: %f \n\nAnd here is my integer: %i \n\nAnd finally my string: %@", aFloat, aInteger, aString);

Insert auto increment primary key to existing table

How to write PHP to ALTER the already existing field (name, in this example) to make it a primary key? W/o, of course, adding any additional 'id' fields to the table..

This a table currently created - Number of Records found: 4 name VARCHAR(20) YES breed VARCHAR(30) YES color VARCHAR(20) YES weight SMALLINT(7) YES

This an end result sought (TABLE DESCRIPTION) -

Number of records found: 4 name VARCHAR(20) NO PRI breed VARCHAR(30) YES color VARCHAR(20) YES weight SMALLINT(7) YES

Instead of getting this -

Number of Records found: 5 id int(11) NO PRI name VARCHAR(20) YES breed VARCHAR(30) YES color VARCHAR(20) YES weight SMALLINT(7) YES

after trying..

$query = "ALTER TABLE racehorses ADD id INT NOT NULL AUTO_INCREMENT FIRST, ADD PRIMARY KEY (id)";

how to get this? -

Number of records found: 4 name VARCHAR(20) NO PRI breed VARCHAR(30) YES color VARCHAR(20) YES weight SMALLINT(7) YES

i.e. INSERT/ADD.. etc. the primary key INTO the first field record (w/o adding an additional 'id' field, as stated earlier.

xls to csv converter

As much as I hate to rely on Windows Excel proprietary software, which is not cross-platform, my testing of csvkit for .xls, which uses xlrd under the hood, failed to correctly parse dates (even when using the commandline parameters to specify strptime format).

For example, this xls file, when parsed with csvkit, will convert cell G1 of 12/31/2002 to 37621, whereas when converted to csv via excel -> save_as (using below) cell G1 will be "December 31, 2002".

import re
import os
from win32com.client import Dispatch
xlCSVMSDOS = 24

class CsvConverter(object):
    def __init__(self, *, input_dir, output_dir):
        self._excel = None
        self.input_dir = input_dir
        self.output_dir = output_dir

        if not os.path.isdir(self.output_dir):
            os.makedirs(self.output_dir)

    def isSheetEmpty(self, sheet):
        # https://archive.is/RuxR7
        # WorksheetFunction.CountA(ActiveSheet.UsedRange) = 0 And ActiveSheet.Shapes.Count = 0

        return \
            (not self._excel.WorksheetFunction.CountA(sheet.UsedRange)) \
            and \
            (not sheet.Shapes.Count)

    def getNonEmptySheets(self, wb, as_name=False):
        return [ \
            (sheet.Name if as_name else sheet) \
            for sheet in wb.Sheets \
            if not self.isSheetEmpty(sheet) \
        ]

    def saveWorkbookAsCsv(self, wb, csv_path):
        non_empty_sheet_names = self.getNonEmptySheets(wb, as_name=True)

        assert (len(non_empty_sheet_names) == 1), \
            "Expected exactly 1 sheet but found %i non-empty sheets: '%s'" \
            %(
                len(non_empty_sheet_names),
                "', '".join(name.replace("'", r"\'") for name in non_empty_sheet_names)
            )

        wb.Worksheets(non_empty_sheet_names[0]).SaveAs(csv_path, xlCSVMSDOS)
        wb.Saved = 1

    def isXlsFilename(self, filename):
        return bool(re.search(r'(?i)\.xls$', filename))

    def batchConvertXlsToCsv(self):
        xls_names = tuple( filename for filename in next(os.walk(self.input_dir))[2] if self.isXlsFilename(filename) )

        self._excel = Dispatch('Excel.Application')
        try:
            for xls_name in xls_names:
                csv_path = os.path.join(self.output_dir, '%s.csv' %os.path.splitext(xls_name)[0])
                if not os.path.isfile(csv_path):
                    workbook = self._excel.Workbooks.Open(os.path.join(self.input_dir, xls_name))
                    try:
                        self.saveWorkbookAsCsv(workbook, csv_path)
                    finally:
                        workbook.Close()
        finally:
            if not len(self._excel.Workbooks):
                self._excel.Quit()

            self._excel = None

if __name__ == '__main__':
    self = CsvConverter(
        input_dir='C:\\data\\xls\\',
        output_dir='C:\\data\\csv\\'
    )

    self.batchConvertXlsToCsv()

The above will take an input_dir containing .xls and output them to output_dir as .csv -- it will assert that there is exactly 1 non-empty sheet in the .xls; if you need to handle multiple sheets into multiple csv then you'll need to edit saveWorkbookAsCsv.

What is the best way to modify a list in a 'foreach' loop?

I have written one easy step, but because of this performance will be degraded

Here is my code snippet:-

for (int tempReg = 0; tempReg < reg.Matches(lines).Count; tempReg++)
                            {
                                foreach (Match match in reg.Matches(lines))
                                {
                                    var aStringBuilder = new StringBuilder(lines);
                                    aStringBuilder.Insert(startIndex, match.ToString().Replace(",", " ");
                                    lines[k] = aStringBuilder.ToString();
                                    tempReg = 0;
                                    break;
                                }
                            }

Namespace not recognized (even though it is there)

I resolved this issue by right clicking on the folder containing the files and choosing Exclude From Project and then right clicking again and selecting Include In Project (you first have to enable Show All Files to make the excluded folder visible)

PHP if not statements

No matter what $action is, it will always either not be "add" OR not be "delete", which is why the if condition always passes. What you want is to use && instead of ||:

(!isset($action)) || ($action !="add" && $action !="delete"))

SOAP or REST for Web Services?

I built one of the first SOAP servers, including code generation and WSDL generation, from the original spec as it was being developed, when I was working at Hewlett-Packard. I do NOT recommend using SOAP for anything.

The acronym "SOAP" is a lie. It is not Simple, it is not Object-oriented, it defines no Access rules. It is, arguably, a Protocol. It is Don Box's worst spec ever, and that's quite a feat, as he's the man who perpetrated "COM".

There is nothing useful in SOAP that can't be done with REST for transport, and JSON, XML, or even plain text for data representation. For transport security, you can use https. For authentication, basic auth. For sessions, there's cookies. The REST version will be simpler, clearer, run faster, and use less bandwidth.

XML-RPC clearly defines the request, response, and error protocols, and there are good libraries for most languages. However, XML is heavier than you need for many tasks.

Visual Studio 6 Windows Common Controls 6.0 (sp6) Windows 7, 64 bit

My solution was replacing the MSCOMCTL.OCX on windows 10 box with one from a Windows 7 box that also had MS Access installed. For some reason, there are different MSCOMCTL.OCX 2.0 controls with the same name.

I know this sounds crazy, and might not help anyone else, but we have saved this MSCOMCTL.OCX with a readme file and it has fixed our new install errors every time.

we unregister the current MSCOMCTL.OCX that came with Windows 10 box, delete it, and register the old one we have saved.

What do <o:p> elements do anyway?

Couldn't find any official documentation (no surprise there) but according to this interesting article, those elements are injected in order to enable Word to convert the HTML back to fully compatible Word document, with everything preserved.

The relevant paragraph:

Microsoft added the special tags to Word's HTML with an eye toward backward compatibility. Microsoft wanted you to be able to save files in HTML complete with all of the tracking, comments, formatting, and other special Word features found in traditional DOC files. If you save a file in HTML and then reload it in Word, theoretically you don't loose anything at all.

This makes lots of sense.

For your specific question.. the o in the <o:p> means "Office namespace" so anything following the o: in a tag means "I'm part of Office namespace" - in case of <o:p> it just means paragraph, the equivalent of the ordinary <p> tag.

I assume that every HTML tag has its Office "equivalent" and they have more.

How to Parse a JSON Object In Android

In your JSON format, it do not have starting JSON object

Like :

{
    "info" :       <!-- this is starting JSON object -->
        {
        "caller":"getPoiById",
        "results":
        {
            "indexForPhone":0,
            "indexForEmail":"NULL",
            .
            .
         }
    }
}

Above Json starts with info as JSON object. So while executing :

JSONObject json = new JSONObject(result);    // create JSON obj from string
JSONObject json2 = json.getJSONObject("info");    // this will return correct

Now, we can access result field :

JSONObject jsonResult = json2.getJSONObject("results");
test = json2.getString("name"); // returns "Marina Rasche Werft GmbH & Co. KG"

I think this was missing and so the problem was solved while we use JSONTokener like answer of yours.

Your answer is very fine. Just i think i add this information so i answered

Thank you

Find an element by class name, from a known parent element

var element = $("#parentDiv .myClassNameOfInterest")

How can I check a C# variable is an empty string "" or null?

Since .NET 2.0 you can use:

// Indicates whether the specified string is null or an Empty string.
string.IsNullOrEmpty(string value);

Additionally, since .NET 4.0 there's a new method that goes a bit farther:

// Indicates whether a specified string is null, empty, or consists only of white-space characters.
string.IsNullOrWhiteSpace(string value);

How can I make a Python script standalone executable to run without ANY dependency?

You may like py2exe. You'll also find information in there for doing it on Linux.

How can I dynamically set the position of view in Android?

One thing to keep in mind with positioning is that each view has an index relative to its parent view. So if you have a linear layout with three subviews, the subviews will each have an index: 0, 1, 2 in the above case.

This allows you to add a view to the last position (or the end) in a parent view by doing something like this:

int childCount = parent.getChildCount();
parentView.addView(newView, childCount);

Alternatively you could replace a view using something like the following:

int childIndex = parentView.indexOfChild(childView);
childView.setVisibility(View.GONE);

parentView.addView(newView, childIndex);

Checking network connection

I added a few to Joel's code.

    import socket,time
    mem1 = 0
    while True:
        try:
                host = socket.gethostbyname("www.google.com") #Change to personal choice of site
                s = socket.create_connection((host, 80), 2)
                s.close()
                mem2 = 1
                if (mem2 == mem1):
                    pass #Add commands to be executed on every check
                else:
                    mem1 = mem2
                    print ("Internet is working") #Will be executed on state change

        except Exception as e:
                mem2 = 0
                if (mem2 == mem1):
                    pass
                else:
                    mem1 = mem2
                    print ("Internet is down")
        time.sleep(10) #timeInterval for checking

Twitter API - Display all tweets with a certain hashtag?

UPDATE for v1.1:

Rather than giving q="search_string" give it q="hashtag" in URL encoded form to return results with HASHTAG ONLY. So your query would become:

    GET https://api.twitter.com/1.1/search/tweets.json?q=%23freebandnames

%23 is URL encoded form of #. Try the link out in your browser and it should work.

You can optimize the query by adding since_id and max_id parameters detailed here. Hope this helps !

Note: Search API is now a OAUTH authenticated call, so please include your access_tokens to the above call

Updated

Twitter Search doc link: https://developer.twitter.com/en/docs/tweets/search/api-reference/get-search-tweets.html

show more/Less text with just HTML and JavaScript

My answer is similar but different, there are a few ways to achieve toggling effect. I guess it depends on your circumstance. This may not be the best way for you in the end.

The missing piece you've been looking for is to create an if statement. This allows for you to toggle your text.

More on if statements here.

JSFiddle: http://jsfiddle.net/8u2jF/

Javascript:

var status = "less";

function toggleText()
{
    var text="Here is some text that I want added to the HTML file";

    if (status == "less") {
        document.getElementById("textArea").innerHTML=text;
        document.getElementById("toggleButton").innerText = "See Less";
        status = "more";
    } else if (status == "more") {
        document.getElementById("textArea").innerHTML = "";
        document.getElementById("toggleButton").innerText = "See More";
        status = "less"
    }
}

How can I send an xml body using requests library?

Pass in the straight XML instead of a dictionary.

How do I center text horizontally and vertically in a TextView?

Here is my answer that I had used in my app. It shows text in center of the screen.

<TextView
    android:id="@+id/txtSubject"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:text="@string/subject"
    android:layout_margin="10dp"
    android:gravity="center"
    android:textAppearance="?android:attr/textAppearanceLarge" />

Combine two columns and add into one new column

Generally, I agree with @kgrittn's advice. Go for it.

But to address your basic question about concat(): The new function concat() is useful if you need to deal with null values - and null has neither been ruled out in your question nor in the one you refer to.

If you can rule out null values, the good old (SQL standard) concatenation operator || is still the best choice, and @luis' answer is just fine:

SELECT col_a || col_b;

If either of your columns can be null, the result would be null in that case. You could defend with COALESCE:

SELECT COALESCE(col_a, '') || COALESCE(col_b, '');

But that get tedious quickly with more arguments. That's where concat() comes in, which never returns null, not even if all arguments are null. Per documentation:

NULL arguments are ignored.

SELECT concat(col_a, col_b);

The remaining corner case for both alternatives is where all input columns are null in which case we still get an empty string '', but one might want null instead (at least I would). One possible way:

SELECT CASE
          WHEN col_a IS NULL THEN col_b
          WHEN col_b IS NULL THEN col_a
          ELSE col_a || col_b
       END;

This gets more complex with more columns quickly. Again, use concat() but add a check for the special condition:

SELECT CASE WHEN (col_a, col_b) IS NULL THEN NULL
            ELSE concat(col_a, col_b) END;

How does this work?
(col_a, col_b) is shorthand notation for a row type expression ROW (col_a, col_b). And a row type is only null if all columns are null. Detailed explanation:

Also, use concat_ws() to add separators between elements (ws for "with separator").


An expression like the one in Kevin's answer:

SELECT $1.zipcode || ' - ' || $1.city || ', ' || $1.state;

is tedious to prepare for null values in PostgreSQL 8.3 (without concat()). One way (of many):

SELECT COALESCE(
         CASE
            WHEN $1.zipcode IS NULL THEN $1.city
            WHEN $1.city    IS NULL THEN $1.zipcode
            ELSE $1.zipcode || ' - ' || $1.city
         END, '')
       || COALESCE(', ' || $1.state, '');

Function volatility is only STABLE

concat() and concat_ws() are STABLE functions, not IMMUTABLE because they can invoke datatype output functions (like timestamptz_out) that depend on locale settings.
Explanation by Tom Lane.

This prohibits their direct use in index expressions. If you know that the result is actually immutable in your case, you can work around this with an IMMUTABLE function wrapper. Example here:

How to remove unwanted space between rows and columns in table?

For standards compliant HTML5 add all this css to remove all space between images in tables:

table { 
    border-spacing: 0;
    border-collapse: collapse;
}
td {
    padding:0px;
}
td img {
    display:block;
}

Making the main scrollbar always visible

I do this:

html {
    margin-left: calc(100vw - 100%);
    margin-right: 0;
}

Then I don't have to look at the ugly greyed out scrollbar when it's not needed.

Python pandas insert list into a cell

As mentionned in this post pandas: how to store a list in a dataframe?; the dtypes in the dataframe may influence the results, as well as calling a dataframe or not to be assigned to.

How to read data from a zip file without having to unzip the entire file

DotNetZip is your friend here.

As easy as:

using (ZipFile zip = ZipFile.Read(ExistingZipFile))
{
  ZipEntry e = zip["MyReport.doc"];
  e.Extract(OutputStream);
}

(you can also extract to a file or other destinations).

Reading the zip file's table of contents is as easy as:

using (ZipFile zip = ZipFile.Read(ExistingZipFile))
{
  foreach (ZipEntry e in zip)
  {
    if (header)
    {
      System.Console.WriteLine("Zipfile: {0}", zip.Name);
      if ((zip.Comment != null) && (zip.Comment != "")) 
        System.Console.WriteLine("Comment: {0}", zip.Comment);
      System.Console.WriteLine("\n{1,-22} {2,8}  {3,5}   {4,8}  {5,3} {0}",
                               "Filename", "Modified", "Size", "Ratio", "Packed", "pw?");
      System.Console.WriteLine(new System.String('-', 72));
      header = false;
    }
    System.Console.WriteLine("{1,-22} {2,8} {3,5:F0}%   {4,8}  {5,3} {0}",
                             e.FileName,
                             e.LastModified.ToString("yyyy-MM-dd HH:mm:ss"),
                             e.UncompressedSize,
                             e.CompressionRatio,
                             e.CompressedSize,
                             (e.UsesEncryption) ? "Y" : "N");

  }
}

Edited To Note: DotNetZip used to live at Codeplex. Codeplex has been shut down. The old archive is still available at Codeplex. It looks like the code has migrated to Github:


Difference between partition key, composite key and clustering key in Cassandra?

There is a lot of confusion around this, I will try to make it as simple as possible.

The primary key is a general concept to indicate one or more columns used to retrieve data from a Table.

The primary key may be SIMPLE and even declared inline:

 create table stackoverflow_simple (
      key text PRIMARY KEY,
      data text      
  );

That means that it is made by a single column.

But the primary key can also be COMPOSITE (aka COMPOUND), generated from more columns.

 create table stackoverflow_composite (
      key_part_one text,
      key_part_two int,
      data text,
      PRIMARY KEY(key_part_one, key_part_two)      
  );

In a situation of COMPOSITE primary key, the "first part" of the key is called PARTITION KEY (in this example key_part_one is the partition key) and the second part of the key is the CLUSTERING KEY (in this example key_part_two)

Please note that the both partition and clustering key can be made by more columns, here's how:

 create table stackoverflow_multiple (
      k_part_one text,
      k_part_two int,
      k_clust_one text,
      k_clust_two int,
      k_clust_three uuid,
      data text,
      PRIMARY KEY((k_part_one, k_part_two), k_clust_one, k_clust_two, k_clust_three)      
  );

Behind these names ...

  • The Partition Key is responsible for data distribution across your nodes.
  • The Clustering Key is responsible for data sorting within the partition.
  • The Primary Key is equivalent to the Partition Key in a single-field-key table (i.e. Simple).
  • The Composite/Compound Key is just any multiple-column key

Further usage information: DATASTAX DOCUMENTATION


Small usage and content examples
SIMPLE KEY:

insert into stackoverflow_simple (key, data) VALUES ('han', 'solo');
select * from stackoverflow_simple where key='han';

table content

key | data
----+------
han | solo

COMPOSITE/COMPOUND KEY can retrieve "wide rows" (i.e. you can query by just the partition key, even if you have clustering keys defined)

insert into stackoverflow_composite (key_part_one, key_part_two, data) VALUES ('ronaldo', 9, 'football player');
insert into stackoverflow_composite (key_part_one, key_part_two, data) VALUES ('ronaldo', 10, 'ex-football player');
select * from stackoverflow_composite where key_part_one = 'ronaldo';

table content

 key_part_one | key_part_two | data
--------------+--------------+--------------------
      ronaldo |            9 |    football player
      ronaldo |           10 | ex-football player

But you can query with all key (both partition and clustering) ...

select * from stackoverflow_composite 
   where key_part_one = 'ronaldo' and key_part_two  = 10;

query output

 key_part_one | key_part_two | data
--------------+--------------+--------------------
      ronaldo |           10 | ex-football player

Important note: the partition key is the minimum-specifier needed to perform a query using a where clause. If you have a composite partition key, like the following

eg: PRIMARY KEY((col1, col2), col10, col4))

You can perform query only by passing at least both col1 and col2, these are the 2 columns that define the partition key. The "general" rule to make query is you have to pass at least all partition key columns, then you can add optionally each clustering key in the order they're set.

so the valid queries are (excluding secondary indexes)

  • col1 and col2
  • col1 and col2 and col10
  • col1 and col2 and col10 and col 4

Invalid:

  • col1 and col2 and col4
  • anything that does not contain both col1 and col2

Hope this helps.

How to change color of Toolbar back button in Android?

You can use your own icon by using app:navigationIcon and for the title color app:titleTextColor

Example:

<android.support.v7.widget.Toolbar
        android:id="@+id/toolbar"
        android:layout_width="match_parent"
        android:layout_height="?actionBarSize"
        android:background="@color/colorPrimary"
        app:navigationIcon="@drawable/ic_arrow_back_white_24dp"
        app:titleTextColor="@color/white" />

Required maven dependencies for Apache POI to work

ooxml for dealing the .xlsx files and the ooxml refers to the xml, hence we will be needed to refer the below three dependedncies in the pom.xml for the

<dependency>
   <groupId>org.apache.poi</groupId>
   <artifactId>poi</artifactId>
   <version>3.9</version>
</dependency>
<dependency>
   <groupId>xml-apis</groupId>
   <artifactId>xml-apis</artifactId>
   <version>1.4.01</version>
</dependency>
<dependency>
   <groupId>org.apache.poi</groupId>
   <artifactId>poi-ooxml</artifactId>
   <version>3.9</version>
   <exclusions>
     <exclusion>
       <artifactId>xml-apis</artifactId>
       <groupId>xml-apis</groupId>
     </exclusion>       
   </exclusions>
</dependency>

How to convert from Hex to ASCII in JavaScript?

I've found that the above solution will not work if you have to deal with control characters like 02 (STX) or 03 (ETX), anything under 10 will be read as a single digit and throw off everything after. I ran into this problem trying to parse through serial communications. So, I first took the hex string received and put it in a buffer object then converted the hex string into an array of the strings like so:

buf = Buffer.from(data, 'hex');
l = Buffer.byteLength(buf,'hex');
for (i=0; i<l; i++){

    char = buf.toString('hex', i, i+1);
    msgArray.push(char);

}

Then .join it

message = msgArray.join('');

then I created a hexToAscii function just like in @Delan Azabani's answer above...

function hexToAscii(str){
    hexString = str;
    strOut = '';
        for (x = 0; x < hexString.length; x += 2) {
            strOut += String.fromCharCode(parseInt(hexString.substr(x, 2), 16));
        }
    return strOut;    
}

then called the hexToAscii function on 'message'

message = hexToAscii(message);

This approach also allowed me to iterate through the array and slice into the different parts of the transmission using the control characters so I could then deal with only the part of the data I wanted. Hope this helps someone else!

How to remove stop words using nltk or python

from nltk.corpus import stopwords 

from nltk.tokenize import word_tokenize 

example_sent = "This is a sample sentence, showing off the stop words filtration."

  
stop_words = set(stopwords.words('english')) 
  
word_tokens = word_tokenize(example_sent) 
  
filtered_sentence = [w for w in word_tokens if not w in stop_words] 
  
filtered_sentence = [] 
  
for w in word_tokens: 
    if w not in stop_words: 
        filtered_sentence.append(w) 
  
print(word_tokens) 
print(filtered_sentence) 

How to temporarily exit Vim and go back

If you don't mind using your mouse a little bit:

  • Start your terminal,
  • select a file,
  • select Open Tab.

This creates a new tab on the terminal which you can run Vim on. Now use your mouse to shift to/from the terminal. I prefer this instead of always having to type (:shell and exit).

What are the differences between a program and an application?

A "program" can be as simple as a "set of instructions" to implement a logic.

It can be part of an "application", "component", "service" or another "program".

Application is a possibly a collection of coordinating program instances to solve a user's purpose.

int to hex string

Try C# string interpolation introduced in C# 6:

var id = 100;
var hexid = $"0x{id:X}";

hexid value:

"0x64"

What is a NullPointerException, and how do I fix it?

In Java all the variables you declare are actually "references" to the objects (or primitives) and not the objects themselves.

When you attempt to execute one object method, the reference asks the living object to execute that method. But if the reference is referencing NULL (nothing, zero, void, nada) then there is no way the method gets executed. Then the runtime let you know this by throwing a NullPointerException.

Your reference is "pointing" to null, thus "Null -> Pointer".

The object lives in the VM memory space and the only way to access it is using this references. Take this example:

public class Some {
    private int id;
    public int getId(){
        return this.id;
    }
    public setId( int newId ) {
        this.id = newId;
    }
}

And on another place in your code:

Some reference = new Some();    // Point to a new object of type Some()
Some otherReference = null;     // Initiallly this points to NULL

reference.setId( 1 );           // Execute setId method, now private var id is 1

System.out.println( reference.getId() ); // Prints 1 to the console

otherReference = reference      // Now they both point to the only object.

reference = null;               // "reference" now point to null.

// But "otherReference" still point to the "real" object so this print 1 too...
System.out.println( otherReference.getId() );

// Guess what will happen
System.out.println( reference.getId() ); // :S Throws NullPointerException because "reference" is pointing to NULL remember...

This an important thing to know - when there are no more references to an object (in the example above when reference and otherReference both point to null) then the object is "unreachable". There is no way we can work with it, so this object is ready to be garbage collected, and at some point, the VM will free the memory used by this object and will allocate another.

How do I add a submodule to a sub-directory?

Note that starting git1.8.4 (July 2013), you wouldn't have to go back to the root directory anymore.

 cd ~/.janus/snipmate-snippets
 git submodule add <git@github ...> snippets

(Bouke Versteegh comments that you don't have to use /., as in snippets/.: snippets is enough)

See commit 091a6eb0feed820a43663ca63dc2bc0bb247bbae:

submodule: drop the top-level requirement

Use the new rev-parse --prefix option to process all paths given to the submodule command, dropping the requirement that it be run from the top-level of the repository.

Since the interpretation of a relative submodule URL depends on whether or not "remote.origin.url" is configured, explicitly block relative URLs in "git submodule add" when not at the top level of the working tree.

Signed-off-by: John Keeping

Depends on commit 12b9d32790b40bf3ea49134095619700191abf1f

This makes 'git rev-parse' behave as if it were invoked from the specified subdirectory of a repository, with the difference that any file paths which it prints are prefixed with the full path from the top of the working tree.

This is useful for shell scripts where we may want to cd to the top of the working tree but need to handle relative paths given by the user on the command line.

Composer require runs out of memory. PHP Fatal error: Allowed memory size of 1610612736 bytes exhausted

what about windows?

i use windows 10 and this command worked for me,

php -d memory_limit=-1 "C:\ProgramData\ComposerSetup\bin\composer.phar" update

PHP random string generator

Here is a simple one-liner that generates a true random string without any script level looping or use of OpenSSL libraries.

echo substr(str_shuffle(str_repeat('0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ', mt_rand(1,10))), 1, 10);

To break it down so the parameters are clear

// Character List to Pick from
$chrList = '0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ';

// Minimum/Maximum times to repeat character List to seed from
$chrRepeatMin = 1; // Minimum times to repeat the seed string
$chrRepeatMax = 10; // Maximum times to repeat the seed string

// Length of Random String returned
$chrRandomLength = 10;

// The ONE LINE random command with the above variables.
echo substr(str_shuffle(str_repeat($chrList, mt_rand($chrRepeatMin,$chrRepeatMax))), 1, $chrRandomLength);

This method works by randomly repeating the character list, then shuffles the combined string, and returns the number of characters specified.

You can further randomize this, by randomizing the length of the returned string, replacing $chrRandomLength with mt_rand(8, 15) (for a random string between 8 and 15 characters).

How to truncate the time on a DateTime object in Python?

There is a module datetime_truncate which handlers this for you. It just calls datetime.replace.

How to delete all the rows in a table using Eloquent?

In my case laravel 4.2 delete all rows ,but not truncate table

DB::table('your_table')->delete();

Cannot invoke an expression whose type lacks a call signature

Perhaps create a shared Fruit interface that provides isDecayed. fruits is now of type Fruit[] so the type can be explicit. Like this:

interface Fruit {
    isDecayed: boolean;
}

interface Apple extends Fruit {
    color: string;
}

interface Pear extends Fruit {
    weight: number;
}

interface FruitBasket {
    apples: Apple[];
    pears: Pear[];
}


const fruitBasket: FruitBasket = { apples: [], pears: [] };
const key: keyof FruitBasket = Math.random() > 0.5 ? 'apples': 'pears'; 
const fruits: Fruit[] = fruitBasket[key];

const freshFruits = fruits.filter((fruit) => !fruit.isDecayed);

How to identify numpy types in python?

Note that the type(numpy.ndarray) is a type itself and watch out for boolean and scalar types. Don't be too discouraged if it's not intuitive or easy, it's a pain at first.

See also: - https://docs.scipy.org/doc/numpy-1.15.1/reference/arrays.dtypes.html - https://github.com/machinalis/mypy-data/tree/master/numpy-mypy

>>> import numpy as np
>>> np.ndarray
<class 'numpy.ndarray'>
>>> type(np.ndarray)
<class 'type'>
>>> a = np.linspace(1,25)
>>> type(a)
<class 'numpy.ndarray'>
>>> type(a) == type(np.ndarray)
False
>>> type(a) == np.ndarray
True
>>> isinstance(a, np.ndarray)
True

Fun with booleans:

>>> b = a.astype('int32') == 11
>>> b[0]
False
>>> isinstance(b[0], bool)
False
>>> isinstance(b[0], np.bool)
False
>>> isinstance(b[0], np.bool_)
True
>>> isinstance(b[0], np.bool8)
True
>>> b[0].dtype == np.bool
True
>>> b[0].dtype == bool  # python equivalent
True

More fun with scalar types, see: - https://docs.scipy.org/doc/numpy-1.15.1/reference/arrays.scalars.html#arrays-scalars-built-in

>>> x = np.array([1,], dtype=np.uint64)
>>> x[0].dtype
dtype('uint64')
>>> isinstance(x[0], np.uint64)
True
>>> isinstance(x[0], np.integer)
True  # generic integer
>>> isinstance(x[0], int)
False  # but not a python int in this case

# Try matching the `kind` strings, e.g.
>>> np.dtype('bool').kind                                                                                           
'b'
>>> np.dtype('int64').kind                                                                                          
'i'
>>> np.dtype('float').kind                                                                                          
'f'
>>> np.dtype('half').kind                                                                                           
'f'

# But be weary of matching dtypes
>>> np.integer
<class 'numpy.integer'>
>>> np.dtype(np.integer)
dtype('int64')
>>> x[0].dtype == np.dtype(np.integer)
False

# Down these paths there be dragons:

# the .dtype attribute returns a kind of dtype, not a specific dtype
>>> isinstance(x[0].dtype, np.dtype)
True
>>> isinstance(x[0].dtype, np.uint64)
False  
>>> isinstance(x[0].dtype, np.dtype(np.uint64))
Traceback (most recent call last):
  File "<console>", line 1, in <module>
TypeError: isinstance() arg 2 must be a type or tuple of types
# yea, don't go there
>>> isinstance(x[0].dtype, np.int_)
False  # again, confusing the .dtype with a specific dtype


# Inequalities can be tricky, although they might
# work sometimes, try to avoid these idioms:

>>> x[0].dtype <= np.dtype(np.uint64)
True
>>> x[0].dtype <= np.dtype(np.float)
True
>>> x[0].dtype <= np.dtype(np.half)
False  # just when things were going well
>>> x[0].dtype <= np.dtype(np.float16)
False  # oh boy
>>> x[0].dtype == np.int
False  # ya, no luck here either
>>> x[0].dtype == np.int_
False  # or here
>>> x[0].dtype == np.uint64
True  # have to end on a good note!

How to execute a .sql script from bash

If you want to run a script to a database:

mysql -u user -p data_base_name_here < db.sql

ValueError: Wrong number of items passed - Meaning and suggestions?

In general, the error ValueError: Wrong number of items passed 3, placement implies 1 suggests that you are attempting to put too many pigeons in too few pigeonholes. In this case, the value on the right of the equation

results['predictedY'] = predictedY

is trying to put 3 "things" into a container that allows only one. Because the left side is a dataframe column, and can accept multiple items on that (column) dimension, you should see that there are too many items on another dimension.

Here, it appears you are using sklearn for modeling, which is where gaussian_process.GaussianProcess() is coming from (I'm guessing, but correct me and revise the question if this is wrong).

Now, you generate predicted values for y here:

predictedY, MSE = gp.predict(testX, eval_MSE = True)

However, as we can see from the documentation for GaussianProcess, predict() returns two items. The first is y, which is array-like (emphasis mine). That means that it can have more than one dimension, or, to be concrete for thick headed people like me, it can have more than one column -- see that it can return (n_samples, n_targets) which, depending on testX, could be (1000, 3) (just to pick numbers). Thus, your predictedY might have 3 columns.

If so, when you try to put something with three "columns" into a single dataframe column, you are passing 3 items where only 1 would fit.

How to get parameter on Angular2 route in Angular way?

As of Angular 6+, this is handled slightly differently than in previous versions. As @BeetleJuice mentions in the answer above, paramMap is new interface for getting route params, but the execution is a bit different in more recent versions of Angular. Assuming this is in a component:

private _entityId: number;

constructor(private _route: ActivatedRoute) {
    // ...
}

ngOnInit() {
    // For a static snapshot of the route...
    this._entityId = this._route.snapshot.paramMap.get('id');

    // For subscribing to the observable paramMap...
    this._route.paramMap.pipe(
        switchMap((params: ParamMap) => this._entityId = params.get('id'))
    );

    // Or as an alternative, with slightly different execution...
    this._route.paramMap.subscribe((params: ParamMap) =>  {
        this._entityId = params.get('id');
    });
}

I prefer to use both because then on direct page load I can get the ID param, and also if navigating between related entities the subscription will update properly.

Source in Angular Docs

Convert string to BigDecimal in java

Spring Framework provides an excellent utils class for achieving this.

Util class : NumberUtils

String to BigDecimal conversion -

NumberUtils.parseNumber("135.00", BigDecimal.class);

Sorting multiple keys with Unix sort

Here is one to sort various columns in a csv file by numeric and dictionary order, columns 5 and after as dictionary order

~/test>sort -t, -k1,1n -k2,2n -k3,3d -k4,4n -k5d  sort.csv
1,10,b,22,Ga
2,2,b,20,F
2,2,b,22,Ga
2,2,c,19,Ga
2,2,c,19,Gb,hi
2,2,c,19,Gb,hj
2,3,a,9,C

~/test>cat sort.csv
2,3,a,9,C
2,2,b,20,F
2,2,c,19,Gb,hj
2,2,c,19,Gb,hi
2,2,c,19,Ga
2,2,b,22,Ga
1,10,b,22,Ga

Note the -k1,1n means numeric starting at column 1 and ending at column 1. If I had done below, it would have concatenated column 1 and 2 making 1,10 sorted as 110

~/test>sort -t, -k1,2n -k3,3 -k4,4n -k5d  sort.csv
2,2,b,20,F
2,2,b,22,Ga
2,2,c,19,Ga
2,2,c,19,Gb,hi
2,2,c,19,Gb,hj
2,3,a,9,C
1,10,b,22,Ga

What is best tool to compare two SQL Server databases (schema and data)?

I've used Red Gate's tools and they are superb. However, if you can't spend any money you could try Open DBDiff to compare schemas.

Can't use System.Windows.Forms

may be necesssary, unreference system.windows.forms and reference again.

Sort Java Collection

You can use java Custom Class for the purpose of sorting.

Could not load file or assembly or one of its dependencies. Access is denied. The issue is random, but after it happens once, it continues

To anyone else who tried most of the solutions and still having problems.

My solution is different from the others, which is located at the bottom of this post, but before you try it make sure you have exhausted the following lists. To be sure, I have tried all of them but to no avail.

  1. Recompile and redeploy from scratch, don't update the existing app. SO Answer

  2. Grant IIS_IUSRS full access to the directory "C:\Windows\Microsoft.NET\Framework\v4.0.30319\Temporary ASP.NET Files"

    Keep in mind the framework version you are using. If your app is using impersonation, use that identity instead of IIS_IUSRS

  3. Delete all contents of the directory "C:\Windows\Microsoft.NET\Framework\v4.0.30319\Temporary ASP.NET Files".

    Keep in mind the framework version you are using

  4. Change the identity of the AppPool that your app is using, from ApplicatonPoolIdentity to NetworkService.

    IIS > Application Pools > Select current app pool > Advance Settings > Identity.

    SO Answer (please restore to default if it doesn't work)

  5. Verify IIS Version and AppPool .NET version compatibility with your app. Highly applicable to first time deployments. SO Answer

  6. Verify impersonation configuration if applicable. SO Answer

My Solution:

I found out that certain anti-virus softwares are actively blocking compilations of DLLs within the directory "Temporary ASP.NET Files", mine was McAfee, the IT people failed to notify me of the installation.

As per advice by both McAfee experts and Microsoft, you need to exclude the directory "Temporary ASP.NET Files" in the real time scanning.

Sources:

Don't disable the Anti-Virus because it is only doing its job. Don't manually copy missing DLL files in the directory \Temporary ASP.NET Files{project name} because thats duct taping.

How can I check for an empty/undefined/null string in JavaScript?

var x ="  ";
var patt = /^\s*$/g;
isBlank = patt.test(x);
alert(isBlank); // Is it blank or not??
x = x.replace(/\s*/g, ""); // Another way of replacing blanks with ""
if (x===""){
    alert("ya it is blank")
}

HTML table with fixed headers and a fixed column?

If what you want is to have the headers stay put while the data in the table scrolls vertically, you should implement a <tbody> styled with "overflow-y: auto" like this:

<table>
  <thead>
    <tr>
      <th>Header1</th>
       . . . 
    </tr>
   </thead>
   <tbody style="height: 300px; overflow-y: auto"> 
     <tr>
       . . .
     </tr>
     . . .
   </tbody>
 </table>

If the <tbody> content grows taller than the desired height, it will start scrolling. However, the headers will stay fixed at the top regardless of the scroll position.

How to read a single char from the console in Java (as the user types it)?

You need to knock your console into raw mode. There is no built-in platform-independent way of getting there. jCurses might be interesting, though.

On a Unix system, this might work:

String[] cmd = {"/bin/sh", "-c", "stty raw </dev/tty"};
Runtime.getRuntime().exec(cmd).waitFor();

For example, if you want to take into account the time between keystrokes, here's sample code to get there.

Parcelable encountered IOException writing serializable object getactivity()

In my case I had to implement MainActivity as Serializable too. Cause I needed to start a service from my MainActivity :

public class MainActivity extends AppCompatActivity implements Serializable {
    ...
    musicCover = new MusicCover(); // A Serializable Object
    ...
    sIntent = new Intent(MainActivity.this, MusicPlayerService.class);
    sIntent.setAction(MusicPlayerService.ACTION_INITIALIZE_COVER);
    sIntent.putExtra(MusicPlayerService.EXTRA_COVER, musicCover);
    startService(sIntent);
}

Keras model.summary() result - Understanding the # of Parameters

For Dense Layers:

output_size * (input_size + 1) == number_parameters 

For Conv Layers:

output_channels * (input_channels * window_size + 1) == number_parameters

Consider following example,

model = Sequential([
Conv2D(32, (3, 3), activation='relu', input_shape=input_shape),
Conv2D(64, (3, 3), activation='relu'),
Conv2D(128, (3, 3), activation='relu'),
Dense(num_classes, activation='softmax')
])

model.summary()
_________________________________________________________________
Layer (type)                 Output Shape              Param #   
=================================================================
conv2d_1 (Conv2D)            (None, 222, 222, 32)      896       
_________________________________________________________________
conv2d_2 (Conv2D)            (None, 220, 220, 64)      18496     
_________________________________________________________________
conv2d_3 (Conv2D)            (None, 218, 218, 128)     73856     
_________________________________________________________________
dense_9 (Dense)              (None, 218, 218, 10)      1290      
=================================================================

Calculating params,

assert 32 * (3 * (3*3) + 1) == 896
assert 64 * (32 * (3*3) + 1) == 18496
assert 128 * (64 * (3*3) + 1) == 73856
assert num_classes * (128 + 1) == 1290

In an array of objects, fastest way to find the index of an object whose attributes match a search

Using the ES6 map function:

let idToFind = 3;
let index = someArray.map(obj => obj.id).indexOf(idToFind);

pandas: filter rows of DataFrame with operator chaining

Filters can be chained using a Pandas query:

df = pd.DataFrame(np.random.randn(30, 3), columns=['a','b','c'])
df_filtered = df.query('a > 0').query('0 < b < 2')

Filters can also be combined in a single query:

df_filtered = df.query('a > 0 and 0 < b < 2')

Where is GACUTIL for .net Framework 4.0 in windows 7?

There is no Gacutil included in the .net 4.0 standard installation. They have moved the GAC too, from %Windir%\assembly to %Windir%\Microsoft.NET\Assembly.

They havent' even bothered adding a "special view" for the folder in Windows explorer, as they have for the .net 1.0/2.0 GAC.

Gacutil is part of the Windows SDK, so if you want to use it on your developement machine, just install the Windows SDK for your current platform. Then you will find it somewhere like this (depending on your SDK version):

C:\Program Files\Microsoft SDKs\Windows\v7.0A\bin\NETFX 4.0 Tools

There is a discussion on the new GAC here: .NET 4.0 has a new GAC, why?

If you want to install something in GAC on a production machine, you need to do it the "proper" way (gacutil was never meant as a tool for installing stuff on production servers, only as a development tool), with a Windows Installer, or with other tools. You can e.g. do it with PowerShell and the System.EnterpriseServices dll.

On a general note, and coming from several years of experience, I would personally strongly recommend against using GAC at all. Your application will always work if you deploy the DLL with each application in its bin folder as well. Yes, you will get multiple copies of the DLL on your server if you have e.g. multiple web apps on one server, but it's definitely worth the flexibility of being able to upgrade one application without breaking the others (by introducing an incompatible version of the shared DLL in the GAC).

Rails 4: List of available datatypes

It is important to know not only the types but the mapping of these types to the database types, too:

enter image description here

enter image description here


Source added - Agile Web Development with Rails 4

How to make a simple collection view with Swift

Delegates and Datasources of UICollectionView

//MARK: UICollectionViewDataSource

override func numberOfSectionsInCollectionView(collectionView: UICollectionView) -> Int {
    return 1     //return number of sections in collection view
}

override func collectionView(collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
    return 10    //return number of rows in section
}

override func collectionView(collectionView: UICollectionView, cellForItemAtIndexPath indexPath: NSIndexPath) -> UICollectionViewCell {
    let cell = collectionView.dequeueReusableCellWithReuseIdentifier("collectionCell", forIndexPath: indexPath)
    configureCell(cell, forItemAtIndexPath: indexPath)
    return cell      //return your cell
}

func configureCell(cell: UICollectionViewCell, forItemAtIndexPath: NSIndexPath) {
    cell.backgroundColor = UIColor.blackColor()


    //Customise your cell

}

override func collectionView(collectionView: UICollectionView, viewForSupplementaryElementOfKind kind: String, atIndexPath indexPath: NSIndexPath) -> UICollectionReusableView {
    let view =  collectionView.dequeueReusableSupplementaryViewOfKind(UICollectionElementKindSectionHeader, withReuseIdentifier: "collectionCell", forIndexPath: indexPath) as UICollectionReusableView
    return view
}

//MARK: UICollectionViewDelegate
override func collectionView(collectionView: UICollectionView, didSelectItemAtIndexPath indexPath: NSIndexPath) {
      // When user selects the cell
}

override func collectionView(collectionView: UICollectionView, didDeselectItemAtIndexPath indexPath: NSIndexPath) {
     // When user deselects the cell
}

LINQ .Any VS .Exists - What's the difference?

TLDR; Performance-wise Any seems to be slower (if I have set this up properly to evaluate both values at almost same time)

        var list1 = Generate(1000000);
        var forceListEval = list1.SingleOrDefault(o => o == "0123456789012");
        if (forceListEval != "sdsdf")
        {
            var s = string.Empty;
            var start2 = DateTime.Now;
            if (!list1.Exists(o => o == "0123456789012"))
            {
                var end2 = DateTime.Now;
                s += " Exists: " + end2.Subtract(start2);
            }

            var start1 = DateTime.Now;
            if (!list1.Any(o => o == "0123456789012"))
            {
                var end1 = DateTime.Now;
                s +=" Any: " +end1.Subtract(start1);
            }

            if (!s.Contains("sdfsd"))
            {

            }

testing list generator:

private List<string> Generate(int count)
    {
        var list = new List<string>();
        for (int i = 0; i < count; i++)
        {
            list.Add( new string(
            Enumerable.Repeat("ABCDEFGHIJKLMNOPQRSTUVWXYZ", 13)
                .Select(s =>
                {
                    var cryptoResult = new byte[4];
                    new RNGCryptoServiceProvider().GetBytes(cryptoResult);
                    return s[new Random(BitConverter.ToInt32(cryptoResult, 0)).Next(s.Length)];
                })
                .ToArray())); 
        }

        return list;
    }

With 10M records

" Any: 00:00:00.3770377 Exists: 00:00:00.2490249"

With 5M records

" Any: 00:00:00.0940094 Exists: 00:00:00.1420142"

With 1M records

" Any: 00:00:00.0180018 Exists: 00:00:00.0090009"

With 500k, (I also flipped around order in which they get evaluated to see if there is no additional operation associated with whichever runs first.)

" Exists: 00:00:00.0050005 Any: 00:00:00.0100010"

With 100k records

" Exists: 00:00:00.0010001 Any: 00:00:00.0020002"

It would seem Any to be slower by magnitude of 2.

Edit: For 5 and 10M records I changed the way it generates the list and Exists suddenly became slower than Any which implies there's something wrong in the way I am testing.

New testing mechanism:

private static IEnumerable<string> Generate(int count)
    {
        var cripto = new RNGCryptoServiceProvider();
        Func<string> getString = () => new string(
            Enumerable.Repeat("ABCDEFGHIJKLMNOPQRSTUVWXYZ", 13)
                .Select(s =>
                {
                    var cryptoResult = new byte[4];
                    cripto.GetBytes(cryptoResult);
                    return s[new Random(BitConverter.ToInt32(cryptoResult, 0)).Next(s.Length)];
                })
                .ToArray());

        var list = new ConcurrentBag<string>();
        var x = Parallel.For(0, count, o => list.Add(getString()));
        return list;
    }

    private static void Test()
    {
        var list = Generate(10000000);
        var list1 = list.ToList();
        var forceListEval = list1.SingleOrDefault(o => o == "0123456789012");
        if (forceListEval != "sdsdf")
        {
            var s = string.Empty;

            var start1 = DateTime.Now;
            if (!list1.Any(o => o == "0123456789012"))
            {
                var end1 = DateTime.Now;
                s += " Any: " + end1.Subtract(start1);
            }

            var start2 = DateTime.Now;
            if (!list1.Exists(o => o == "0123456789012"))
            {
                var end2 = DateTime.Now;
                s += " Exists: " + end2.Subtract(start2);
            }

            if (!s.Contains("sdfsd"))
            {

            }
        }

Edit2: Ok so to eliminate any influence from generating test data I wrote it all to file and now read it from there.

 private static void Test()
    {
        var list1 = File.ReadAllLines("test.txt").Take(500000).ToList();
        var forceListEval = list1.SingleOrDefault(o => o == "0123456789012");
        if (forceListEval != "sdsdf")
        {
            var s = string.Empty;
            var start1 = DateTime.Now;
            if (!list1.Any(o => o == "0123456789012"))
            {
                var end1 = DateTime.Now;
                s += " Any: " + end1.Subtract(start1);
            }

            var start2 = DateTime.Now;
            if (!list1.Exists(o => o == "0123456789012"))
            {
                var end2 = DateTime.Now;
                s += " Exists: " + end2.Subtract(start2);
            }

            if (!s.Contains("sdfsd"))
            {
            }
        }
    }

10M

" Any: 00:00:00.1640164 Exists: 00:00:00.0750075"

5M

" Any: 00:00:00.0810081 Exists: 00:00:00.0360036"

1M

" Any: 00:00:00.0190019 Exists: 00:00:00.0070007"

500k

" Any: 00:00:00.0120012 Exists: 00:00:00.0040004"

enter image description here

Difference Between Cohesion and Coupling

Theory Difference

Cohesion

  • Cohesion is an indication of relative functional strength of module.
  • A cohesive module performs a single task, requiring little interaction with other components in other parts of program.
  • A module having high cohesion and low coupling is said to be functionally independent of other module.

Classification of Cohesion

1.Coincidental 2.Logical 3.Temporal 4.Procedural 5.Communication 6.Sequential 7.Functional

Coupling

  • Coupling is indication of relative interdependence among modules.
  • Degree of coupling between two modules depends on their interface complexity.

How to get Android crash logs?

If your app is being downloaded by other people and crashing on remote devices, you may want to look into an Android error reporting library (referenced in this SO post). If it's just on your own local device, you can use LogCat. Even if the device wasn't connected to a host machine when the crash occurred, connecting the device and issuing an adb logcat command will download the entire logcat history (at least to the extent that it is buffered which is usually a loooot of log data, it's just not infinite). Do either of those options answer your question? If not can you attempt to clarify what you're looking for a bit more?

Setting SMTP details for php mail () function

Under Windows only: You may try to use ini_set() functionDocs for the SMTPDocs and smtp_portDocs settings:

ini_set('SMTP', 'mysmtphost'); 
ini_set('smtp_port', 25); 

How can I remove time from date with Moment.js?

Try this:

moment.format().split("T")[0]

Combining C++ and C - how does #ifdef __cplusplus work?

extern "C" doesn't really change the way that the compiler reads the code. If your code is in a .c file, it will be compiled as C, if it is in a .cpp file, it will be compiled as C++ (unless you do something strange to your configuration).

What extern "C" does is affect linkage. C++ functions, when compiled, have their names mangled -- this is what makes overloading possible. The function name gets modified based on the types and number of parameters, so that two functions with the same name will have different symbol names.

Code inside an extern "C" is still C++ code. There are limitations on what you can do in an extern "C" block, but they're all about linkage. You can't define any new symbols that can't be built with C linkage. That means no classes or templates, for example.

extern "C" blocks nest nicely. There's also extern "C++" if you find yourself hopelessly trapped inside of extern "C" regions, but it isn't such a good idea from a cleanliness perspective.

Now, specifically regarding your numbered questions:

Regarding #1: __cplusplus will stay defined inside of extern "C" blocks. This doesn't matter, though, since the blocks should nest neatly.

Regarding #2: __cplusplus will be defined for any compilation unit that is being run through the C++ compiler. Generally, that means .cpp files and any files being included by that .cpp file. The same .h (or .hh or .hpp or what-have-you) could be interpreted as C or C++ at different times, if different compilation units include them. If you want the prototypes in the .h file to refer to C symbol names, then they must have extern "C" when being interpreted as C++, and they should not have extern "C" when being interpreted as C -- hence the #ifdef __cplusplus checking.

To answer your question #3: functions without prototypes will have C++ linkage if they are in .cpp files and not inside of an extern "C" block. This is fine, though, because if it has no prototype, it can only be called by other functions in the same file, and then you don't generally care what the linkage looks like, because you aren't planning on having that function be called by anything outside the same compilation unit anyway.

For #4, you've got it exactly. If you are including a header for code that has C linkage (such as code that was compiled by a C compiler), then you must extern "C" the header -- that way you will be able to link with the library. (Otherwise, your linker would be looking for functions with names like _Z1hic when you were looking for void h(int, char)

5: This sort of mixing is a common reason to use extern "C", and I don't see anything wrong with doing it this way -- just make sure you understand what you are doing.

UICollectionView spacing margins

In swift 4 and autoLayout, you can use sectionInset like this:

let layout = UICollectionViewFlowLayout()
        layout.scrollDirection = .vertical
        layout.itemSize = CGSize(width: (view.frame.width-40)/2, height: (view.frame.width40)/2) // item size
        layout.sectionInset = UIEdgeInsetsMake(10, 10, 10, 10) // here you can add space to 4 side of item
        collectionView = UICollectionView(frame: self.view.bounds, collectionViewLayout: layout) // set layout to item
        collectionView?.register(ProductCategoryCell.self, forCellWithReuseIdentifier: cellIdentifier) // registerCell
        collectionView?.backgroundColor = .white // background color of UICollectionView
        view.addSubview(collectionView!) // add UICollectionView to view

How to create a folder with name as current date in batch (.bat) files

This works for me, try:

ECHO %DATE:~7,2%_%DATE:~4,2%_%DATE:~12,2%

How to split a line into words separated by one or more spaces in bash?

More simple,

echo $line | sed 's/\s/\n/g'

\s --> whitespace character (space, tab, NL, FF, VT, CR). In many systems also valid [:space:]

\n --> new line

How to set Spring profile from system variable?

My solution is to set the environment variable as spring.profiles.active=development. So that all applications running in that machine will refer the variable and start the application. The order in which spring loads a properties as follows

application.properties
system properties
environment variable

In Android EditText, how to force writing uppercase?

Use input filter

editText = (EditText) findViewById(R.id.enteredText);
editText.setFilters(new InputFilter[]{new InputFilter.AllCaps()});

Assign keyboard shortcut to run procedure

Here is how to assign a keyboard shortcut to a custom macro in Word 2013. The scenario is you created a macro named "fred" and you want to execute the macro by typing Ctrl+f.

  1. Click on File, Options.
  2. Click on Customize Ribbon (from my perspective this is the non-intuitive step).
  3. Click "Keyboard shortcuts: Customize" button.
  4. In the Categories listbox scroll down to the buttom and select Macros.
  5. The Macros list box should now show the list of custom macros. Select "fred".
  6. Click the "Press new shortcut key" textbox to make it active.
  7. Type Ctrl+f. This should appear in the textbox.
  8. Look at the "Current keys" listbox. In this case it shows "Currently assigned to NavPaneSearch".
  9. If you don't mind overriding that default, click the "Assign" button on the lower-left to assign "Ctrl+f: to run your "fred" macro.

By default the assignment is saved in the Normal.dotm document template. If this keyboard assignment is unique to this document then you may wish to change the "Save changes in" dropdown to your document name.

How to change the minSdkVersion of a project?

Set the min SDK version in your project's AndroidManifest.xml file and in the toolbar search for "Sync Projects with Gradle Files" icon. It works for me.

Also look for your project's build.gradle file and update the min sdk version.

Automatically resize images with browser size using CSS

The following works on all browsers for my 200 figures, for any width percentage -- despite being illegal. Jukka said 'Use it anyway.' (The class just floats the image left or right and sets margins.) I can't imagine why this isn't the standard approach!

<img class="fl" width="66%"
src="A-Images/0.5_Saltation.jpg"
alt="Schematic models of chromosomes ..." />

Change the window width and the image scales obligingly.

jQuery find file extension (from string)

var fileName = 'file.txt';

// Getting Extension

var ext = fileName.split('.')[1];

// OR

var ext = fileName.split('.').pop();

Consider defining a bean of type 'service' in your configuration [Spring boot]

In case you were wondering where to add @Service annotation, then make sure you have added @Service annotation to the class that implements the interface. That would solve this problem.

Why is there no SortedList in Java?

Think of it like this: the List interface has methods like add(int index, E element), set(int index, E element). The contract is that once you added an element at position X you will find it there unless you add or remove elements before it.

If any list implementation would store elements in some order other than based on the index, the above list methods would make no sense.