Programs & Examples On #Overload resolution

Overload resolution is a language mechanism to select among several viable function overloads. Its rules are intricate and often surprising, even for experienced users.

Installing SciPy and NumPy using pip

in my case, upgrading pip did the trick. Also, I've installed scipy with -U parameter (upgrade all packages to the last available version)

Implement a simple factory pattern with Spring 3 annotations

The following worked for me:

The interface consist of you logic methods plus additional identity method:

public interface MyService {
    String getType();
    void checkStatus();
}

Some implementations:

@Component
public class MyServiceOne implements MyService {
    @Override
    public String getType() {
        return "one";
    }

    @Override
    public void checkStatus() {
      // Your code
    }
}

@Component
public class MyServiceTwo implements MyService {
    @Override
    public String getType() {
        return "two";
    }

    @Override
    public void checkStatus() {
      // Your code
    }
}

@Component
public class MyServiceThree implements MyService {
    @Override
    public String getType() {
        return "three";
    }

    @Override
    public void checkStatus() {
      // Your code
    }
}

And the factory itself as following:

@Service
public class MyServiceFactory {

    @Autowired
    private List<MyService> services;

    private static final Map<String, MyService> myServiceCache = new HashMap<>();

    @PostConstruct
    public void initMyServiceCache() {
        for(MyService service : services) {
            myServiceCache.put(service.getType(), service);
        }
    }

    public static MyService getService(String type) {
        MyService service = myServiceCache.get(type);
        if(service == null) throw new RuntimeException("Unknown service type: " + type);
        return service;
    }
}

I've found such implementation easier, cleaner and much more extensible. Adding new MyService is as easy as creating another spring bean implementing same interface without making any changes in other places.

Generate a UUID on iOS from Swift

You could also just use the NSUUID API:

let uuid = NSUUID()

If you want to get the string value back out, you can use uuid.UUIDString.

Note that NSUUID is available from iOS 6 and up.

How can I preview a merge in git?

Most answers here either require a clean working directory and multiple interactive steps (bad for scripting), or don't work for all cases, e.g. past merges which already bring some of the outstanding changes into your target branch, or cherry-picks doing the same.

To truly see what would change in the master branch if you merged develop into it, right now:

git merge-tree $(git merge-base master develop) master develop

As it's a plumbing command, it does not guess what you mean, you have to be explicit. It also doesn't colorize the output or use your pager, so the full command would be:

git merge-tree $(git merge-base master develop) master develop | colordiff | less -R

https://git.seveas.net/previewing-a-merge-result.html

(thanks to David Normington for the link)

P.S.:

If you would get merge conflicts, they will show up with the usual conflict markers in the output, e.g.:

$ git merge-tree $(git merge-base a b ) a b 
added in both
  our    100644 78981922613b2afb6025042ff6bd878ac1994e85 a
  their  100644 61780798228d17af2d34fce4cfbdf35556832472 a
@@ -1 +1,5 @@
+<<<<<<< .our
 a
+=======
+b
+>>>>>>> .their

User @dreftymac makes a good point: this makes it unsuitable for scripting, because you can't easily catch that from the status code. The conflict markers can be quite different depending on circumstance (deleted vs modified, etc), which makes it hard to grep, too. Beware.

Set IDENTITY_INSERT ON is not working

In VB code, when trying to submit an INSERT query, you must submit a double query in the same 'executenonquery' like this:

sqlQuery = "SET IDENTITY_INSERT dbo.TheTable ON; INSERT INTO dbo.TheTable (Col1, COl2) VALUES (Val1, Val2); SET IDENTITY_INSERT dbo.TheTable OFF;"

I used a ; separator instead of a GO.

Works for me. Late but efficient!

SUM OVER PARTITION BY

I think the query you want is this:

SELECT BrandId, SUM(ICount),
       SUM(sum(ICount)) over () as TotalCount,
       100.0 * SUM(ICount) / SUM(sum(Icount)) over () as Percentage
FROM Table 
WHERE DateId  = 20130618
group by BrandId;

This does the group by for brand. And it calculates the "Percentage". This version should produce a number between 0 and 100.

SQL Statement using Where clause with multiple values

Select t1.SongName
From tablename t1
left join tablename t2
 on t1.SongName = t2.SongName
    and t1.PersonName <> t2.PersonName
    and t1.Status = 'Complete' -- my assumption that this is necessary
    and t2.Status = 'Complete' -- my assumption that this is necessary
    and t1.PersonName IN ('Holly', 'Ryan')
    and t2.PersonName IN ('Holly', 'Ryan')

SQL Server find and replace specific word in all rows of specific column

UPDATE tblKit
SET number = REPLACE(number, 'KIT', 'CH')
WHERE number like 'KIT%'

or simply this if you are sure that you have no values like this CKIT002

UPDATE tblKit
SET number = REPLACE(number, 'KIT', 'CH')

Allow scroll but hide scrollbar

It's better, if you use two div containers in HTML .

As Shown Below:

HTML:

<div id="container1">
    <div id="container2">
        // Content here
    </div>
</div>

CSS:

 #container1{
    height: 100%;
    width: 100%;
    overflow: hidden;
}

 #container2{
    height: 100%;
    width: 100%;
    overflow: auto;
    padding-right: 20px;
}

Best way to define error codes/strings in Java?

As far as I am concerned, I prefer to externalize the error messages in a properties files. This will be really helpful in case of internationalization of your application (one properties file per language). It is also easier to modify an error message, and it won't need any re-compilation of the Java sources.

On my projects, generally I have an interface that contains errors codes (String or integer, it doesn't care much), which contains the key in the properties files for this error:

public interface ErrorCodes {
    String DATABASE_ERROR = "DATABASE_ERROR";
    String DUPLICATE_USER = "DUPLICATE_USER";
    ...
}

in the properties file:

DATABASE_ERROR=An error occurred in the database.
DUPLICATE_USER=The user already exists.
...

Another problem with your solution is the maintenability: you have only 2 errors, and already 12 lines of code. So imagine your Enumeration file when you will have hundreds of errors to manage!

How to Retrieve value from JTextField in Java Swing?

testField.getText()

See the java doc for JTextField

Sample code can be:

button.addActionListener(new ActionListener(){
   public void actionPerformed(ActionEvent ae){
      String textFieldValue = testField.getText();
      // .... do some operation on value ...
   }
})

What is difference between sjlj vs dwarf vs seh?

SJLJ (setjmp/longjmp): – available for 32 bit and 64 bit – not “zero-cost”: even if an exception isn’t thrown, it incurs a minor performance penalty (~15% in exception heavy code) – allows exceptions to traverse through e.g. windows callbacks

DWARF (DW2, dwarf-2) – available for 32 bit only – no permanent runtime overhead – needs whole call stack to be dwarf-enabled, which means exceptions cannot be thrown over e.g. Windows system DLLs.

SEH (zero overhead exception) – will be available for 64-bit GCC 4.8.

source: https://wiki.qt.io/MinGW-64-bit

How can I take a screenshot/image of a website using Python?

You can use Google Page Speed API to achieve your task easily. In my current project, I have used Google Page Speed API`s query written in Python to capture screenshots of any Web URL provided and save it to a location. Have a look.

import urllib2
import json
import base64
import sys
import requests
import os
import errno

#   The website's URL as an Input
site = sys.argv[1]
imagePath = sys.argv[2]

#   The Google API.  Remove "&strategy=mobile" for a desktop screenshot
api = "https://www.googleapis.com/pagespeedonline/v1/runPagespeed?screenshot=true&strategy=mobile&url=" + urllib2.quote(site)

#   Get the results from Google
try:
    site_data = json.load(urllib2.urlopen(api))
except urllib2.URLError:
    print "Unable to retreive data"
    sys.exit()

try:
    screenshot_encoded =  site_data['screenshot']['data']
except ValueError:
    print "Invalid JSON encountered."
    sys.exit()

#   Google has a weird way of encoding the Base64 data
screenshot_encoded = screenshot_encoded.replace("_", "/")
screenshot_encoded = screenshot_encoded.replace("-", "+")

#   Decode the Base64 data
screenshot_decoded = base64.b64decode(screenshot_encoded)

if not os.path.exists(os.path.dirname(impagepath)):
    try:
        os.makedirs(os.path.dirname(impagepath))
        except  OSError as exc:
            if exc.errno  != errno.EEXIST:
                raise

#   Save the file
with open(imagePath, 'w') as file_:
    file_.write(screenshot_decoded)

Unfortunately, following are the drawbacks. If these do not matter, you can proceed with Google Page Speed API. It works well.

  • The maximum width is 320px
  • According to Google API Quota, there is a limit of 25,000 requests per day

What does "make oldconfig" do exactly in the Linux kernel makefile?

Summary

As mentioned by Ignacio, it updates your .config for you after you update the kernel source, e.g. with git pull.

It tries to keep your existing options.

Having a script for that is helpful because:

  • new options may have been added, or old ones removed

  • the kernel's Kconfig configuration format has options that:

    • imply one another via select
    • depend on another via depends

    Those option relationships make manual config resolution even harder.

Let's modify .config manually to understand how it resolves configurations

First generate a default configuration with:

make defconfig

Now edit the generated .config file manually to emulate a kernel update and run:

make oldconfig

to see what happens. Some conclusions:

  1. Lines of type:

    # CONFIG_XXX is not set
    

    are not mere comments, but actually indicate that the parameter is not set.

    For example, if we remove the line:

    # CONFIG_DEBUG_INFO is not set
    

    and run make oldconfig, it will ask us:

    Compile the kernel with debug info (DEBUG_INFO) [N/y/?] (NEW)
    

    When it is over, the .config file will be updated.

    If you change any character of the line, e.g. to # CONFIG_DEBUG_INFO, it does not count.

  2. Lines of type:

    # CONFIG_XXX is not set
    

    are always used for the negation of a property, although:

    CONFIG_XXX=n
    

    is also understood as the negation.

    For example, if you remove # CONFIG_DEBUG_INFO is not set and answer:

    Compile the kernel with debug info (DEBUG_INFO) [N/y/?] (NEW)
    

    with N, then the output file contains:

    # CONFIG_DEBUG_INFO is not set
    

    and not:

    CONFIG_DEBUG_INFO=n
    

    Also, if we manually modify the line to:

    CONFIG_DEBUG_INFO=n
    

    and run make oldconfig, then the line gets modified to:

    # CONFIG_DEBUG_INFO is not set
    

    without oldconfig asking us.

  3. Configs whose dependencies are not met, do not appear on the .config. All others do.

    For example, set:

    CONFIG_DEBUG_INFO=y
    

    and run make oldconfig. It will now ask us for: DEBUG_INFO_REDUCED, DEBUG_INFO_SPLIT, etc. configs.

    Those properties did not appear on the defconfig before.

    If we look under lib/Kconfig.debug where they are defined, we see that they depend on DEBUG_INFO:

    config DEBUG_INFO_REDUCED
        bool "Reduce debugging information"
        depends on DEBUG_INFO
    

    So when DEBUG_INFO was off, they did not show up at all.

  4. Configs which are selected by turned on configs are automatically set without asking the user.

    For example, if CONFIG_X86=y and we remove the line:

    CONFIG_ARCH_MIGHT_HAVE_PC_PARPORT=y
    

    and run make oldconfig, the line gets recreated without asking us, unlike DEBUG_INFO.

    This happens because arch/x86/Kconfig contains:

    config X86
        def_bool y
        [...]
        select ARCH_MIGHT_HAVE_PC_PARPORT
    

    and select forces that option to be true. See also: https://unix.stackexchange.com/questions/117521/select-vs-depends-in-kernel-kconfig

  5. Configs whose constraints are not met are asked for.

    For example, defconfig had set:

    CONFIG_64BIT=y
    CONFIG_RCU_FANOUT=64
    

    If we edit:

    CONFIG_64BIT=n
    

    and run make oldconfig, it will ask us:

    Tree-based hierarchical RCU fanout value (RCU_FANOUT) [32] (NEW)
    

    This is because RCU_FANOUT is defined at init/Kconfig as:

    config RCU_FANOUT
        int "Tree-based hierarchical RCU fanout value"
        range 2 64 if 64BIT
        range 2 32 if !64BIT
    

    Therefore, without 64BIT, the maximum value is 32, but we had 64 set on the .config, which would make it inconsistent.

Bonuses

make olddefconfig sets every option to their default value without asking interactively. It gets run automatically on make to ensure that the .config is consistent in case you've modified it manually like we did. See also: https://serverfault.com/questions/116299/automatically-answer-defaults-when-doing-make-oldconfig-on-a-kernel-tree

make alldefconfig is like make olddefconfig, but it also accepts a config fragment to merge. This target is used by the merge_config.sh script: https://stackoverflow.com/a/39440863/895245

And if you want to automate the .config modification, that is not too simple: How do you non-interactively turn on features in a Linux kernel .config file?

How to deserialize a list using GSON or another JSON library in Java?

Another way is to use an array as a type, e.g.:

Video[] videoArray = gson.fromJson(json, Video[].class);

This way you avoid all the hassle with the Type object, and if you really need a list you can always convert the array to a list, e.g.:

List<Video> videoList = Arrays.asList(videoArray);

IMHO this is much more readable.


In Kotlin this looks like this:

Gson().fromJson(jsonString, Array<Video>::class.java)

To convert this array into List, just use .toList() method

How to extract base URL from a string in JavaScript?

WebKit-based browsers, Firefox as of version 21 and current versions of Internet Explorer (IE 10 and 11) implement location.origin.

location.origin includes the protocol, the domain and optionally the port of the URL.

For example, location.origin of the URL http://www.sitename.com/article/2009/09/14/this-is-an-article/ is http://www.sitename.com.

To target browsers without support for location.origin use the following concise polyfill:

if (typeof location.origin === 'undefined')
    location.origin = location.protocol + '//' + location.host;

Cannot run the macro... the macro may not be available in this workbook

This error also occurs if you create a sub or function in a 'Microsoft Excel Object' (like Sheet1, Sheet2, ...) instead to create it in a Module.

For example: you create with VBA a button and set .OnAction = 'btn_action' . And Sub btn_action you placed into the Sheet object instead into a Module.

How to stop C# console applications from closing automatically?

Console.ReadLine() to wait for the user to Enter or Console.ReadKey to wait for any key.

Sending HTML Code Through JSON

All these answers didn't work for me.

But this one did:

json_encode($array, JSON_HEX_QUOT | JSON_HEX_TAG);

Thanks to this answer.

How do I POST a x-www-form-urlencoded request using Fetch?

Just Use

import  qs from "qs";
 let data = {
        'profileId': this.props.screenProps[0],
        'accountId': this.props.screenProps[1],
        'accessToken': this.props.screenProps[2],
        'itemId': this.itemId
    };
    return axios.post(METHOD_WALL_GET, qs.stringify(data))

What is an efficient way to implement a singleton pattern in Java?

public class Singleton {

    private static final Singleton INSTANCE = new Singleton();

    private Singleton() {
        if (INSTANCE != null)
            throw new IllegalStateException(“Already instantiated...”);
        }


    public synchronized static Singleton getInstance() {
        return INSTANCE;
    }

}

As we have added the Synchronized keyword before getInstance, we have avoided the race condition in the case when two threads call the getInstance at the same time.

Setting up Vim for Python

In general, vim is a very powerful regular language editor (macros extend this but we'll ignore that for now). This is because vim's a thin layer on top of ed, and ed isn't much more than a line editor that speaks regex. Emacs has the advantage of being built on top of ELisp; lending it the ability to easily parse complex grammars and perform indentation tricks like the one you shared above.

To be honest, I've never been able to dive into the depths of emacs because it is simply delightful meditating within my vim cave. With that said, let's jump in.

Getting Started

Janus

For beginners, I highly recommend installing the readymade Janus plugin (fwiw, the name hails from a Star Trek episode featuring Janus Vim). If you want a quick shortcut to a vim IDE it's your best bang for your buck.

I've never used it much, but I've seen others use it happily and my current setup is borrowed heavily from an old Janus build.

Vim Pathogen

Otherwise, do some exploring on your own! I'd highly recommend installing vim pathogen if you want to see the universe of vim plugins.

It's a package manager of sorts. Once you install it, you can git clone packages to your ~/.vim/bundle directory and they're auto-installed. No more plugin installation, maintenance, or uninstall headaches!

You can run the following script from the GitHub page to install pathogen:

mkdir -p ~/.vim/autoload ~/.vim/bundle; \
curl -so ~/.vim/autoload/pathogen.vim \
    https://raw.github.com/tpope/vim-pathogen/HEAD/autoload/pathogen.vim

Helpful Links

Here are some links on extending vim I've found and enjoyed:

SQL Server Group By Month

DECLARE @start [datetime] = 2010/4/1;

Should be...

DECLARE @start [datetime] = '2010-04-01';

The one you have is dividing 2010 by 4, then by 1, then converting to a date. Which is the 57.5th day from 1900-01-01.

Try SELECT @start after your initialisation to check if this is correct.

Pick images of root folder from sub-folder

Your index.html can just do src="images/logo.png" and from sub.html you would do src="../images/logo.png"

How to get browser width using JavaScript code?

From W3schools and its cross browser back to the dark ages of IE!

<!DOCTYPE html>
<html>
<body>

<p id="demo"></p>

<script>
var w = window.innerWidth
|| document.documentElement.clientWidth
|| document.body.clientWidth;

var h = window.innerHeight
|| document.documentElement.clientHeight
|| document.body.clientHeight;

var x = document.getElementById("demo");
x.innerHTML = "Browser inner window width: " + w + ", height: " + h + ".";

alert("Browser inner window width: " + w + ", height: " + h + ".");

</script>

</body>
</html>

Decimal to Hexadecimal Converter in Java

Code to convert DECIMAL -to-> BINARY, OCTAL, HEXADECIMAL

public class ConvertBase10ToBaseX {
    enum Base {
        /**
         * Integer is represented in 32 bit in 32/64 bit machine.
         * There we can split this integer no of bits into multiples of 1,2,4,8,16 bits
         */
        BASE2(1,1,32), BASE4(3,2,16), BASE8(7,3,11)/* OCTAL*/, /*BASE10(3,2),*/ 
        BASE16(15, 4, 8){       
            public String getFormattedValue(int val){
                switch(val) {
                case 10:
                    return "A";
                case 11:
                    return "B";
                case 12:
                    return "C";
                case 13:
                    return "D";
                case 14:
                    return "E";
                case 15:
                    return "F";
                default:
                    return "" + val;
                }

            }
        }, /*BASE32(31,5,1),*/ BASE256(255, 8, 4), /*BASE512(511,9),*/ Base65536(65535, 16, 2);

        private int LEVEL_0_MASK;
        private int LEVEL_1_ROTATION;
        private int MAX_ROTATION;

        Base(int levelZeroMask, int levelOneRotation, int maxPossibleRotation) {
            this.LEVEL_0_MASK = levelZeroMask;
            this.LEVEL_1_ROTATION = levelOneRotation;
            this.MAX_ROTATION = maxPossibleRotation;
        }

        int getLevelZeroMask(){
            return LEVEL_0_MASK;
        }
        int getLevelOneRotation(){
            return LEVEL_1_ROTATION;
        }
        int getMaxRotation(){
            return MAX_ROTATION;
        }
        String getFormattedValue(int val){
            return "" + val;
        }
    }

    public void getBaseXValueOn(Base base, int on) {
        forwardPrint(base, on);
    }

    private void forwardPrint(Base base, int on) {

        int rotation = base.getLevelOneRotation();
        int mask = base.getLevelZeroMask();
        int maxRotation = base.getMaxRotation();
        boolean valueFound = false;

        for(int level = maxRotation; level >= 2; level--) {
            int rotation1 = (level-1) * rotation;
            int mask1 = mask << rotation1 ;
            if((on & mask1) > 0 ) {
                valueFound = true;
            }
            if(valueFound)
            System.out.print(base.getFormattedValue((on & mask1) >>> rotation1));
        }
        System.out.println(base.getFormattedValue((on & mask)));
    }

    public int getBaseXValueOnAtLevel(Base base, int on, int level) {
        if(level > base.getMaxRotation() || level < 1) {
            return 0; //INVALID Input
        }
        int rotation = base.getLevelOneRotation();
        int mask = base.getLevelZeroMask();

        if(level > 1) {
            rotation = (level-1) * rotation;
            mask = mask << rotation;
        } else {
            rotation = 0;
        }


        return (on & mask) >>> rotation;
    }

    public static void main(String[] args) {
        ConvertBase10ToBaseX obj = new ConvertBase10ToBaseX();

        obj.getBaseXValueOn(Base.BASE16,12456); 
//      obj.getBaseXValueOn(Base.BASE16,300); 
//      obj.getBaseXValueOn(Base.BASE16,7); 
//      obj.getBaseXValueOn(Base.BASE16,7);

        obj.getBaseXValueOn(Base.BASE2,12456);
        obj.getBaseXValueOn(Base.BASE8,12456);
        obj.getBaseXValueOn(Base.BASE2,8);
        obj.getBaseXValueOn(Base.BASE2,9);
        obj.getBaseXValueOn(Base.BASE2,10);
        obj.getBaseXValueOn(Base.BASE2,11);
        obj.getBaseXValueOn(Base.BASE2,12);
        obj.getBaseXValueOn(Base.BASE2,13);
        obj.getBaseXValueOn(Base.BASE2,14);
        obj.getBaseXValueOn(Base.BASE2,15);
        obj.getBaseXValueOn(Base.BASE2,16);
        obj.getBaseXValueOn(Base.BASE2,17);


        System.out.println(obj.getBaseXValueOnAtLevel(Base.BASE2, 4, 1)); 
        System.out.println(obj.getBaseXValueOnAtLevel(Base.BASE2, 4, 2)); 
        System.out.println(obj.getBaseXValueOnAtLevel(Base.BASE2, 4, 3)); 
        System.out.println(obj.getBaseXValueOnAtLevel(Base.BASE2, 4, 4)); 

        System.out.println(obj.getBaseXValueOnAtLevel(Base.BASE16,15, 1)); 
        System.out.println(obj.getBaseXValueOnAtLevel(Base.BASE16,30, 2)); 
        System.out.println(obj.getBaseXValueOnAtLevel(Base.BASE16,7, 1)); 
        System.out.println(obj.getBaseXValueOnAtLevel(Base.BASE16,7, 2)); 

        System.out.println(obj.getBaseXValueOnAtLevel(Base.BASE256, 511, 1)); 
        System.out.println(obj.getBaseXValueOnAtLevel(Base.BASE256, 511, 2)); 
        System.out.println(obj.getBaseXValueOnAtLevel(Base.BASE256, 512, 1));
        System.out.println(obj.getBaseXValueOnAtLevel(Base.BASE256, 512, 2)); 
        System.out.println(obj.getBaseXValueOnAtLevel(Base.BASE256, 513, 2)); 


    }
}

Eclipse executable launcher error: Unable to locate companion shared library

if you are having two eclipse then sometime this happens

you only have to remove

-startup
plugins\org.eclipse.equinox.launcher_1.0.100.v20080509-1800.jar 

from eclipse.ini file beside eclipse.exe(Launcher)

Why an abstract class implementing an interface can miss the declaration/implementation of one of the interface's methods?

That's fine. To understand the above, you have to understand the nature of abstract classes first. They are similar to interfaces in that respect. This is what Oracle say about this here.

Abstract classes are similar to interfaces. You cannot instantiate them, and they may contain a mix of methods declared with or without an implementation.

So you have to think about what happens when an interface extends another interface. For example ...

//Filename: Sports.java
public interface Sports
{
   public void setHomeTeam(String name);
   public void setVisitingTeam(String name);
}

//Filename: Football.java
public interface Football extends Sports
{
   public void homeTeamScored(int points);
   public void visitingTeamScored(int points);
   public void endOfQuarter(int quarter);
}

... as you can see, this also compiles perfectly fine. Simply because, just like an abstract class, an interface can NOT be instantiated. So, it is not required to explicitly mention the methods from its "parent". However, ALL the parent method signatures DO implicitly become a part of the extending interface or implementing abstract class. So, once a proper class (one that can be instantiated) extends the above, it WILL be required to ensure that every single abstract method is implemented.

Hope that helps... and Allahu 'alam !

PHP - Extracting a property from an array of objects

Warning create_function() has been DEPRECATED as of PHP 7.2.0. Relying on this function is highly discouraged.

You can use the array_map() function.
This should do it:

$catIds = array_map(create_function('$o', 'return $o->id;'), $objects);

As @Relequestual writes below, the function is now integrated directly in the array_map. The new version of the solution looks like this:

$catIds = array_map(function($o) { return $o->id;}, $objects);

how to make password textbox value visible when hover an icon

   <script>
       function seetext(x){
           x.type = "text";
       }
       function seeasterisk(x){
          x.type = "password";
       }
   </script>
  <body>
    <img onmouseover="seetext(a)" onmouseout="seeasterisk(a)" border="0" src="smiley.gif"   alt="Smiley" width="32" height="32">
   <input id = "a" type = "password"/>
 </body>

Try this see if it works

How do I handle Database Connections with Dapper in .NET?

I do it like this:

internal class Repository : IRepository {

    private readonly Func<IDbConnection> _connectionFactory;

    public Repository(Func<IDbConnection> connectionFactory) 
    {
        _connectionFactory = connectionFactory;
    }

    public IWidget Get(string key) {
        using(var conn = _connectionFactory()) 
        {
            return conn.Query<Widget>(
               "select * from widgets with(nolock) where widgetkey=@WidgetKey", new { WidgetKey=key });
        }
    }
}

Then, wherever I wire-up my dependencies (ex: Global.asax.cs or Startup.cs), I do something like:

var connectionFactory = new Func<IDbConnection>(() => {
    var conn = new SqlConnection(
        ConfigurationManager.ConnectionStrings["connectionString-name"];
    conn.Open();
    return conn;
});

How to check python anaconda version installed on Windows 10 PC?

On the anaconda prompt, do a

  • conda -V or conda --version to get the conda version.
  • python -V or python --version to get the python version.
  • conda list anaconda$ to get the Anaconda version.
  • conda list to get the Name, Version, Build & Channel details of all the packages installed (in the current environment).
  • conda info to get all the current environment details.
  • conda info --envs To see a list of all your environments

Detailed description here, download cheat sheet from here

Automatic date update in a cell when another cell's value changes (as calculated by a formula)

You could fill the dependend cell (D2) by a User Defined Function (VBA Macro Function) that takes the value of the C2-Cell as input parameter, returning the current date as ouput.

Having C2 as input parameter for the UDF in D2 tells Excel that it needs to reevaluate D2 everytime C2 changes (that is if auto-calculation of formulas is turned on for the workbook).

EDIT:

Here is some code:

For the UDF:

    Public Function UDF_Date(ByVal data) As Date

        UDF_Date = Now()

    End Function

As Formula in D2:

=UDF_Date(C2)

You will have to give the D2-Cell a Date-Time Format, or it will show a numeric representation of the date-value.

And you can expand the formula over the desired range by draging it if you keep the C2 reference in the D2-formula relative.

Note: This still might not be the ideal solution because every time Excel recalculates the workbook the date in D2 will be reset to the current value. To make D2 only reflect the last time C2 was changed there would have to be some kind of tracking of the past value(s) of C2. This could for example be implemented in the UDF by providing also the address alonside the value of the input parameter, storing the input parameters in a hidden sheet, and comparing them with the previous values everytime the UDF gets called.

Addendum:

Here is a sample implementation of an UDF that tracks the changes of the cell values and returns the date-time when the last changes was detected. When using it, please be aware that:

  • The usage of the UDF is the same as described above.

  • The UDF works only for single cell input ranges.

  • The cell values are tracked by storing the last value of cell and the date-time when the change was detected in the document properties of the workbook. If the formula is used over large datasets the size of the file might increase considerably as for every cell that is tracked by the formula the storage requirements increase (last value of cell + date of last change.) Also, maybe Excel is not capable of handling very large amounts of document properties and the code might brake at a certain point.

  • If the name of a worksheet is changed all the tracking information of the therein contained cells is lost.

  • The code might brake for cell-values for which conversion to string is non-deterministic.

  • The code below is not tested and should be regarded only as proof of concept. Use it at your own risk.

    Public Function UDF_Date(ByVal inData As Range) As Date
    
        Dim wb As Workbook
        Dim dProps As DocumentProperties
        Dim pValue As DocumentProperty
        Dim pDate As DocumentProperty
        Dim sName As String
        Dim sNameDate As String
    
        Dim bDate As Boolean
        Dim bValue As Boolean
        Dim bChanged As Boolean
    
        bDate = True
        bValue = True
    
        bChanged = False
    
    
        Dim sVal As String
        Dim dDate As Date
    
        sName = inData.Address & "_" & inData.Worksheet.Name
        sNameDate = sName & "_dat"
    
        sVal = CStr(inData.Value)
        dDate = Now()
    
        Set wb = inData.Worksheet.Parent
    
        Set dProps = wb.CustomDocumentProperties
    
    On Error Resume Next
    
        Set pValue = dProps.Item(sName)
    
        If Err.Number <> 0 Then
            bValue = False
            Err.Clear
        End If
    
    On Error GoTo 0
    
        If Not bValue Then
            bChanged = True
            Set pValue = dProps.Add(sName, False, msoPropertyTypeString, sVal)
        Else
            bChanged = pValue.Value <> sVal
            If bChanged Then
                pValue.Value = sVal
            End If
        End If
    
    On Error Resume Next
    
        Set pDate = dProps.Item(sNameDate)
    
        If Err.Number <> 0 Then
            bDate = False
            Err.Clear
        End If
    
    On Error GoTo 0
    
        If Not bDate Then
            Set pDate = dProps.Add(sNameDate, False, msoPropertyTypeDate, dDate)
        End If
    
        If bChanged Then
            pDate.Value = dDate
        Else
            dDate = pDate.Value
        End If
    
    
        UDF_Date = dDate
     End Function
    

Make the insertion of the date conditional upon the range.

This has an advantage of not changing the dates unless the content of the cell is changed, and it is in the range C2:C2, even if the sheet is closed and saved, it doesn't recalculate unless the adjacent cell changes.

Adapted from this tip and @Paul S answer

Private Sub Worksheet_Change(ByVal Target As Range)
 Dim R1 As Range
 Dim R2 As Range
 Dim InRange As Boolean
    Set R1 = Range(Target.Address)
    Set R2 = Range("C2:C20")
    Set InterSectRange = Application.Intersect(R1, R2)

  InRange = Not InterSectRange Is Nothing
     Set InterSectRange = Nothing
   If InRange = True Then
     R1.Offset(0, 1).Value = Now()
   End If
     Set R1 = Nothing
     Set R2 = Nothing
 End Sub

How to remove new line characters from a string?

I know this is an old post, however I thought I'd share the method I use to remove new line characters.

s.Replace(Environment.NewLine, "");

References:

MSDN String.Replace Method and MSDN Environment.NewLine Property

Meaning of "n:m" and "1:n" in database design

Many to Many (n:m) One to Many (1:n)

Using ConfigurationManager to load config from an arbitrary location

Ishmaeel's answer generally does work, however I found one issue, which is that using OpenMappedMachineConfiguration seems to lose your inherited section groups from machine.config. This means that you can access your own custom sections (which is all the OP wanted), but not the normal system sections. For example, this code will not work:

ConfigurationFileMap fileMap = new ConfigurationFileMap(strConfigPath);
Configuration configuration = ConfigurationManager.OpenMappedMachineConfiguration(fileMap);
MailSettingsSectionGroup thisMail = configuration.GetSectionGroup("system.net/mailSettings") as MailSettingsSectionGroup;  // returns null

Basically, if you put a watch on the configuration.SectionGroups, you'll see that system.net is not registered as a SectionGroup, so it's pretty much inaccessible via the normal channels.

There are two ways I found to work around this. The first, which I don't like, is to re-implement the system section groups by copying them from machine.config into your own web.config e.g.

<sectionGroup name="system.net" type="System.Net.Configuration.NetSectionGroup, System, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089">
  <sectionGroup name="mailSettings" type="System.Net.Configuration.MailSettingsSectionGroup, System, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089">
    <section name="smtp" type="System.Net.Configuration.SmtpSection, System, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" />
  </sectionGroup>
</sectionGroup>

I'm not sure the web application itself will run correctly after that, but you can access the sectionGroups correctly.

The second solution it is instead to open your web.config as an EXE configuration, which is probably closer to its intended function anyway:

ExeConfigurationFileMap fileMap = new ExeConfigurationFileMap() { ExeConfigFilename = strConfigPath };
Configuration configuration = ConfigurationManager.OpenMappedExeConfiguration(fileMap, ConfigurationUserLevel.None);
MailSettingsSectionGroup thisMail = configuration.GetSectionGroup("system.net/mailSettings") as MailSettingsSectionGroup;  // returns valid object!

I daresay none of the answers provided here, neither mine or Ishmaeel's, are quite using these functions how the .NET designers intended. But, this seems to work for me.

cannot download, $GOPATH not set

This one worked

Setting up Go development environment on Ubuntu, and how to fix $GOPATH / $GOROOT

Steps

mkdir ~/go

Set $GOPATH in .bashrc,

export GOPATH=~/go
export PATH=$PATH:$GOPATH/bin

Passing dynamic javascript values using Url.action()

The @Url.Action() method is proccess on the server-side, so you cannot pass a client-side value to this function as a parameter. You can concat the client-side variables with the server-side url generated by this method, which is a string on the output. Try something like this:

var firstname = "abc";
var username = "abcd";
location.href = '@Url.Action("Display", "Customer")?uname=' + firstname + '&name=' + username;

The @Url.Action("Display", "Customer") is processed on the server-side and the rest of the string is processed on the client-side, concatenating the result of the server-side method with the client-side.

How do I put my website's logo to be the icon image in browser tabs?

Add a icon file named "favicon.ico" to the root of your website.

How to insert an item into an array at a specific index (JavaScript)?

I tried this and it is working fine!

var initialArr = ["India","China","Japan","USA"];
initialArr.splice(index, 0, item);

Index is the position where you want to insert or delete the element. 0 i.e. the second parameters defines the number of element from the index to be removed item are the new entries which you want to make in array. It can be one or more than one.

initialArr.splice(2, 0, "Nigeria");
initialArr.splice(2, 0, "Australia","UK");

QLabel: set color of text and background

The best way to set any feature regarding the colors of any widget is to use QPalette.

And the easiest way to find what you are looking for is to open Qt Designer and set the palette of a QLabel and check the generated code.

How to dismiss a Twitter Bootstrap popover by clicking outside?

This is late to the party... but I thought I'd share it. I love the popover but it has so little built-in functionality. I wrote a bootstrap extension .bubble() that is everything I'd like popover to be. Four ways to dismiss. Click outside, toggle on the link, click the X, and hit escape.

It positions automatically so it never goes off the page.

https://github.com/Itumac/bootstrap-bubble

This is not a gratuitous self promo...I've grabbed other people's code so many times in my life, I wanted to offer my own efforts. Give it a whirl and see if it works for you.

unresolved external symbol __imp__fprintf and __imp____iob_func, SDL2

I resolve this problem with following function. I use Visual Studio 2019.

FILE* __cdecl __iob_func(void)
{
    FILE _iob[] = { *stdin, *stdout, *stderr };
    return _iob;
}

because stdin Macro defined function call, "*stdin" expression is cannot used global array initializer. But local array initialier is possible. sorry, I am poor at english.

How do you create an asynchronous method in C#?

One very simple way to make a method asynchronous is to use Task.Yield() method. As MSDN states:

You can use await Task.Yield(); in an asynchronous method to force the method to complete asynchronously.

Insert it at beginning of your method and it will then return immediately to the caller and complete the rest of the method on another thread.

private async Task<DateTime> CountToAsync(int num = 1000)
{
    await Task.Yield();
    for (int i = 0; i < num; i++)
    {
        Console.WriteLine("#{0}", i);
    }
    return DateTime.Now;
}

How to change value of process.env.PORT in node.js?

use the below command to set the port number in node process while running node JS programme:

set PORT =3000 && node file_name.js

The set port can be accessed in the code as

process.env.PORT 

Cannot declare instance members in a static class in C#

Have you tried using the 'static' storage class similar to?:

public static class employee
{
    static NameValueCollection appSetting = ConfigurationManager.AppSettings;    
}

How do I make a transparent border with CSS?

Yep, you can use border: 1px solid transparent

Another solution is to use outline on hover (and set the border to 0) which doesn't affect the document flow:

li{
    display:inline-block;
    padding:5px;
    border:0;
}
li:hover{
    outline:1px solid #FC0;
}

NB. You can only set the outline as a sharthand property, not for individual sides. It's only meant to be used for debugging but it works nicely.

Multiple file extensions in OpenFileDialog

This is from MSDN sample:

(*.bmp, *.jpg)|*.bmp;*.jpg

So for your case

openFileDialog1.Filter = "JPG (*.jpg,*.jpeg)|*.jpg;*.jpeg|TIFF (*.tif,*.tiff)|*.tif;*.tiff"

UIButton: set image for selected-highlighted state

If you need the highlighted tint which the OS provides by default when you tap and hold on a custom button for the selected state as well, use this UIButton subclass. Written in Swift 5:

import Foundation
import UIKit
class HighlightOnSelectCustomButton: UIButton {
    override var isHighlighted: Bool {
        didSet {
            if (self.isSelected != isHighlighted) {
                self.isHighlighted = self.isSelected
            }
        }
    }
}

How to serialize Joda DateTime with Jackson JSON processor?

It seems that for Jackson 1.9.12 there is no such possibility by default, because of:

public final static class DateTimeSerializer
    extends JodaSerializer<DateTime>
{
    public DateTimeSerializer() { super(DateTime.class); }

    @Override
    public void serialize(DateTime value, JsonGenerator jgen, SerializerProvider provider)
        throws IOException, JsonGenerationException
    {
        if (provider.isEnabled(SerializationConfig.Feature.WRITE_DATES_AS_TIMESTAMPS)) {
            jgen.writeNumber(value.getMillis());
        } else {
            jgen.writeString(value.toString());
        }
    }

    @Override
    public JsonNode getSchema(SerializerProvider provider, java.lang.reflect.Type typeHint)
    {
        return createSchemaNode(provider.isEnabled(SerializationConfig.Feature.WRITE_DATES_AS_TIMESTAMPS)
                ? "number" : "string", true);
    }
}

This class serializes data using toString() method of Joda DateTime.

Approach proposed by Rusty Kuntz works perfect for my case.

\n or \n in php echo not print

Escape sequences (and variables too) work inside double quoted and heredoc strings. So change your code to:

echo '<p>' . $unit1 . "</p>\n";

PS: One clarification, single quotes strings do accept two escape sequences:

  • \' when you want to use single quote inside single quoted strings
  • \\ when you want to use backslash literally

Spring expected at least 1 bean which qualifies as autowire candidate for this dependency

If there is an interface anywhere in the ThreadProvider hierarchy try putting the name of the Interface as the type of your service provider, eg. if you have say this structure:

public class ThreadProvider implements CustomInterface{
...
}

Then in your controller try this:

@Controller
public class ChiusuraController {

    @Autowired
    private CustomInterface chiusuraProvider;
}

The reason why this is happening is, in your first case when you DID NOT have ChiusuraProvider extend ThreadProvider Spring probably was underlying creating a CGLIB based proxy for you(to handle the @Transaction).

When you DID extend from ThreadProvider assuming that ThreadProvider extends some interface, Spring in that case creates a Java Dynamic Proxy based Proxy, which would appear to be an implementation of that interface instead of being of ChisuraProvider type.

If you absolutely need to use ChisuraProvider you can try AspectJ as an alternative or force CGLIB based proxy in the case with ThreadProvider also this way:

<aop:aspectj-autoproxy proxy-target-class="true"/>

Here is some more reference on this from the Spring Reference site: http://static.springsource.org/spring/docs/3.1.x/spring-framework-reference/html/classic-aop-spring.html#classic-aop-pfb

Found a swap file by the name

Looks like you have an open git commit or git merge going on, and an editor is still open editing the commit message.

Two choices:

  1. Find the session and finish it (preferable).
  2. Delete the .swp file (if you're sure the other git session has gone away).

Clarification from comments:

  • The session is the editing session.
  • You can see what .swp is being used by entering the command :sw within the editing session, but generally it's a hidden file in the same directory as the file you are using, with a .swp file suffix (i.e. ~/myfile.txt would be ~/.myfile.txt.swp).

Best algorithm for detecting cycles in a directed graph

If you can't add a "visited" property to the nodes, use a set (or map) and just add all visited nodes to the set unless they are already in the set. Use a unique key or the address of the objects as the "key".

This also gives you the information about the "root" node of the cyclic dependency which will come in handy when a user has to fix the problem.

Another solution is to try to find the next dependency to execute. For this, you must have some stack where you can remember where you are now and what you need to do next. Check if a dependency is already on this stack before you execute it. If it is, you've found a cycle.

While this might seem to have a complexity of O(N*M) you must remember that the stack has a very limited depth (so N is small) and that M becomes smaller with each dependency that you can check off as "executed" plus you can stop the search when you found a leaf (so you never have to check every node -> M will be small, too).

In MetaMake, I created the graph as a list of lists and then deleted every node as I executed them which naturally cut down the search volume. I never actually had to run an independent check, it all happened automatically during normal execution.

If you need a "test only" mode, just add a "dry-run" flag which disables the execution of the actual jobs.

Merge (Concat) Multiple JSONObjects in Java

Today, I was also struggling to merge JSON objects and came with following solution (uses Gson library).

private JsonObject mergeJsons(List<JsonObject> jsonObjs) {
    JsonObject mergedJson = new JsonObject();
    jsonObjs.forEach((JsonObject jsonObj) -> {
        Set<Map.Entry<String, JsonElement>> entrySet = jsonObj.entrySet();
        entrySet.forEach((next) -> {
            mergedJson.add(next.getKey(), next.getValue());
        });
    });
    return mergedJson;
}

Android - set TextView TextStyle programmatically?

This question is asked in a lot of places in a lot of different ways. I originally answered it here but I feel it's relevant in this thread as well (since i ended up here when I was searching for an answer).

There is no one line solution to this problem, but this worked for my use case. The problem is, the 'View(context, attrs, defStyle)' constructor does not refer to an actual style, it wants an attribute. So, we will:

  1. Define an attribute
  2. Create a style that you want to use
  3. Apply a style for that attribute on our theme
  4. Create new instances of our view with that attribute

In 'res/values/attrs.xml', define a new attribute:

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <attr name="customTextViewStyle" format="reference"/>
    ...
</resources>    

In res/values/styles.xml' I'm going to create the style I want to use on my custom TextView

<style name="CustomTextView">
    <item name="android:textSize">18sp</item>
    <item name="android:textColor">@color/white</item>
    <item name="android:paddingLeft">14dp</item>
</style>

In 'res/values/themes.xml' or 'res/values/styles.xml', modify the theme for your application / activity and add the following style:

<resources>
    <style name="AppBaseTheme" parent="android:Theme.Light">
        <item name="@attr/customTextViewStyle">@style/CustomTextView</item>
    </style>
    ... 
</resources>

Finally, in your custom TextView, you can now use the constructor with the attribute and it will receive your style

public class CustomTextView extends TextView {

    public CustomTextView(Context context) {
       super(context, null, R.attr.customTextView);
    }
}

It's worth noting that I repeatedly used customTextView in different variants and different places, but it is in no way required that the name of the view match the style or the attribute or anything. Also, this technique should work with any custom view, not just TextViews.

round up to 2 decimal places in java?

I know this is 2 year old question but as every body faces a problem to round off the values at some point of time.I would like to share a different way which can give us rounded values to any scale by using BigDecimal class .Here we can avoid extra steps which are required to get the final value if we use DecimalFormat("0.00") or using Math.round(a * 100) / 100 .

import java.math.BigDecimal;

public class RoundingNumbers {
    public static void main(String args[]){
        double number = 123.13698;
        int decimalsToConsider = 2;
        BigDecimal bigDecimal = new BigDecimal(number);
        BigDecimal roundedWithScale = bigDecimal.setScale(2, BigDecimal.ROUND_HALF_UP);
        System.out.println("Rounded value with setting scale = "+roundedWithScale);

        bigDecimal = new BigDecimal(number);
        BigDecimal roundedValueWithDivideLogic = bigDecimal.divide(BigDecimal.ONE,decimalsToConsider,BigDecimal.ROUND_HALF_UP);
        System.out.println("Rounded value with Dividing by one = "+roundedValueWithDivideLogic);

    }
}

This program would give us below output

Rounded value with setting scale = 123.14
Rounded value with Dividing by one = 123.14

Search for an item in a Lua list

You're seeing firsthand one of the cons of Lua having only one data structure---you have to roll your own. If you stick with Lua you will gradually accumulate a library of functions that manipulate tables in the way you like to do things. My library includes a list-to-set conversion and a higher-order list-searching function:

function table.set(t) -- set of list
  local u = { }
  for _, v in ipairs(t) do u[v] = true end
  return u
end

function table.find(f, l) -- find element v of l satisfying f(v)
  for _, v in ipairs(l) do
    if f(v) then
      return v
    end
  end
  return nil
end

How do I resolve "HTTP Error 500.19 - Internal Server Error" on IIS7.0

Got this working alright but not based on suggestions above. My case is that am getting the 500 error running iis7 on a windows 2008 server in a domain. Just added a new user in the domain and basically allow read/execute access to the virtual directory or folder. Ensure that the virtual folder>basic settings> Connect As > Path credentials is set to a user with read/xecute access. You can test settings and both authentication and authorization should work. Cheers!

Use of var keyword in C#

var is a placeholder introduced for the anonymous types in C# 3.0 and LINQ.

As such, it allows writing LINQ queries for a fewer amount of columns within, let's say, a collection. No need to duplicate the information in memory, only load what's necessary to accomplish what you need to be done.

The use of var is not bad at all, as it is actually not a type, but as mentioned elsewhere, a placeholder for the type which is and has to be defined on the right-hand side of the equation. Then, the compiler will replace the keyword with the type itself.

It is particularly useful when, even with IntelliSense, the name of a type is long to type. Just write var, and instantiate it. The other programmers who will read your code afterward will easily understand what you're doing.

It's like using

public object SomeObject { get; set; }

instead of:

public object SomeObject {
    get {
        return _someObject;
    } 
    set {
        _someObject = value;
    }
}
private object _someObject;

Everyone knows what's the property's doing, as everyone knows what the var keyword is doing, and either examples tend to ease readability by making it lighter, and make it more pleasant for the programmer to write effective code.

How to fix broken paste clipboard in VNC on Windows

I use Remote login with vnc-ltsp-config with GNOME Desktop Environment on CentOS 5.9. From experimenting today, I managed to get cut and paste working for the session and the login prompt (because I'm lazy and would rather copy and paste difficult passwords).

  1. I created a file vncconfig.desktop in the /etc/xdg/autostart directory which enabled cut and paste during the session after login. The vncconfig process is run as the logged in user.

    [Desktop Entry]
    Name=No name
    Encoding=UTF-8
    Version=1.0
    Exec=vncconfig -nowin
    X-GNOME-Autostart-enabled=true

  2. Added vncconfig -nowin & to the bottom of the file /etc/gdm/Init/Desktop which enabled cut and paste in the session during login but terminates after login. The vncconfig process is run as root.

  3. Adding vncconfig -nowin & to the bottom of the file /etc/gdm/PostLogin/Desktop also enabled cut and paste during the session after login. The vncconfig process is run as root however.

HTML-encoding lost when attribute read from input field

As far as I know there isn't any straight forward HTML Encode/Decode method in javascript.

However, what you can do, is to use JS to create an arbitrary element, set its inner text, then read it using innerHTML.

Let's say, with jQuery, this should work:

var helper = $('chalk & cheese').hide().appendTo('body');
var htmled = helper.html();
helper.remove();

Or something along these lines.

Using PowerShell to write a file in UTF-8 without the BOM

This script will convert, to UTF-8 without BOM, all .txt files in DIRECTORY1 and output them to DIRECTORY2

foreach ($i in ls -name DIRECTORY1\*.txt)
{
    $file_content = Get-Content "DIRECTORY1\$i";
    [System.IO.File]::WriteAllLines("DIRECTORY2\$i", $file_content);
}

Dark color scheme for Eclipse

For Linux users, assuming you run a compositing window manager (Compiz), you can just turn the window negative. I use Eclipse like this all the time, the normal (whitie) looks is blowing my eyes off.

AWS - Disconnected : No supported authentication methods available (server sent :publickey)

During ssh session my connection broke, since then I cannot ssh my SRV, I had started a new instance, and I'm able to ssh the new instance (with the same key).

I mounted the old volume to the new machine, and check the .ssh/authorized_key and couldn't find any problem with permission or content.

Error "Metadata file '...\Release\project.dll' could not be found in Visual Studio"

Did you check the Configuration manager settings? In the project settings dialog top right corner.

Sometimes it happens that between all the release entries a debug entry comes in. If so, the auto dependency created by the dependency graph of the solution gets all confused.

Mailx send html message

I had successfully used the following on Arch Linux (where the -a flag is used for attachments) for several years:

mailx -s "The Subject $( echo -e "\nContent-Type: text/html" [email protected] < email.html

This appended the Content-Type header to the subject header, which worked great until a recent update. Now the new line is filtered out of the -s subject. Presumably, this was done to improve security.

Instead of relying on hacking the subject line, I now use a bash subshell:

(
    echo -e "Content-Type: text/html\n"
    cat mail.html
 ) | mail -s "The Subject" -t [email protected]

And since we are really only using mailx's subject flag, it seems there is no reason not to switch to sendmail as suggested by @dogbane:

(
    echo "To: [email protected]"
    echo "Subject: The Subject"
    echo "Content-Type: text/html"
    echo
    cat mail.html
) | sendmail -t

The use of bash subshells avoids having to create a temporary file.

How do I display images from Google Drive on a website?

1 - Create a folder in your google drive;

2 - Make this folder public (on share property)

3 - use something like this as your image src: https://drive.google.com/thumbnail?id=${imageId}&sz=w${width || 200}-h${height || 200}

When do Java generics require <? extends T> instead of <T> and is there any downside of switching?

First - I have to direct you to http://www.angelikalanger.com/GenericsFAQ/JavaGenericsFAQ.html -- she does an amazing job.

The basic idea is that you use

<T extends SomeClass>

when the actual parameter can be SomeClass or any subtype of it.

In your example,

Map<String, Class<? extends Serializable>> expected = null;
Map<String, Class<java.util.Date>> result = null;
assertThat(result, is(expected));

You're saying that expected can contain Class objects that represent any class that implements Serializable. Your result map says it can only hold Date class objects.

When you pass in result, you're setting T to exactly Map of String to Date class objects, which doesn't match Map of String to anything that's Serializable.

One thing to check -- are you sure you want Class<Date> and not Date? A map of String to Class<Date> doesn't sound terribly useful in general (all it can hold is Date.class as values rather than instances of Date)

As for genericizing assertThat, the idea is that the method can ensure that a Matcher that fits the result type is passed in.

What's the difference between text/xml vs application/xml for webservice response

From the RFC (3023), under section 3, XML Media Types:

If an XML document -- that is, the unprocessed, source XML document -- is readable by casual users, text/xml is preferable to application/xml. MIME user agents (and web user agents) that do not have explicit support for text/xml will treat it as text/plain, for example, by displaying the XML MIME entity as plain text. Application/xml is preferable when the XML MIME entity is unreadable by casual users.

(emphasis mine)

How to add data via $.ajax ( serialize() + extra data ) like this

You can do it like this:

postData[postData.length] = { name: "variable_name", value: variable_value };

What's the difference between ng-model and ng-bind

ngModel usually use for input tags for bind a variable that we can change variable from controller and html page but ngBind use for display a variable in html page and we can change variable just from controller and html just show variable.

Maximum on http header values?

HTTP does not place a predefined limit on the length of each header field or on the length of the header section as a whole, as described in Section 2.5. Various ad hoc limitations on individual header field length are found in practice, often depending on the specific field semantics.

HTTP Header values are restricted by server implementations. Http specification doesn't restrict header size.

A server that receives a request header field, or set of fields, larger than it wishes to process MUST respond with an appropriate 4xx (Client Error) status code. Ignoring such header fields would increase the server's vulnerability to request smuggling attacks (Section 9.5).

Most servers will return 413 Entity Too Large or appropriate 4xx error when this happens.

A client MAY discard or truncate received header fields that are larger than the client wishes to process if the field semantics are such that the dropped value(s) can be safely ignored without changing the message framing or response semantics.

Uncapped HTTP header size keeps the server exposed to attacks and can bring down its capacity to serve organic traffic.

Source

Inserting data into a temporary table

My way of Insert in SQL Server. Also I usually check if a temporary table exists.

IF OBJECT_ID('tempdb..#MyTable') IS NOT NULL DROP Table #MyTable

SELECT b.Val as 'bVals'
  INTO #MyTable
FROM OtherTable as b

No tests found with test runner 'JUnit 4'

Check if the folder your tests are in is a source folder. If not - right click and use as source folder.

fs: how do I locate a parent folder?

Use path.join http://nodejs.org/docs/v0.4.10/api/path.html#path.join

var path = require("path"),
    fs = require("fs");

fs.readFile(path.join(__dirname, '..', '..', 'foo.bar'));

path.join() will handle leading/trailing slashes for you and just do the right thing and you don't have to try to remember when trailing slashes exist and when they dont.

Elegant way to check for missing packages and install them?

Almost all the answers here rely on either (1) require() or (2) installed.packages() to check if a given package is already installed or not.

I'm adding an answer because these are unsatisfactory for a lightweight approach to answering this question.

  • require has the side effect of loading the package's namespace, which may not always be desirable
  • installed.packages is a bazooka to light a candle -- it will check the universe of installed packages first, then we check if our one (or few) package(s) are "in stock" at this library. No need to build a haystack just to find a needle.

This answer was also inspired by @ArtemKlevtsov's great answer in a similar spirit on a duplicated version of this question. He noted that system.file(package=x) can have the desired affect of returning '' if the package isn't installed, and something with nchar > 1 otherwise.

If we look under the hood of how system.file accomplishes this, we can see it uses a different base function, find.package, which we could use directly:

# a package that exists
find.package('data.table', quiet=TRUE)
# [1] "/Library/Frameworks/R.framework/Versions/4.0/Resources/library/data.table"

# a package that does not
find.package('InstantaneousWorldPeace', quiet=TRUE)
# character(0)

We can also look under the hood at find.package to see how it works, but this is mainly an instructive exercise -- the only ways to slim down the function that I see would be to skip some robustness checks. But the basic idea is: look in .libPaths() -- any installed package pkg will have a DESCRIPTION file at file.path(.libPaths(), pkg), so a quick-and-dirty check is file.exists(file.path(.libPaths(), pkg, 'DESCRIPTION').

Change column type in pandas

this below code will change datatype of column.

df[['col.name1', 'col.name2'...]] = df[['col.name1', 'col.name2'..]].astype('data_type')

in place of data type you can give your datatype .what do you want like str,float,int etc.

'mat-form-field' is not a known element - Angular 5 & Material2

I had this problem too. It turned out I forgot to include one of the components in app.module.ts

When to use virtual destructors?

Virtual destructors are useful when you might potentially delete an instance of a derived class through a pointer to base class:

class Base 
{
    // some virtual methods
};

class Derived : public Base
{
    ~Derived()
    {
        // Do some important cleanup
    }
};

Here, you'll notice that I didn't declare Base's destructor to be virtual. Now, let's have a look at the following snippet:

Base *b = new Derived();
// use b
delete b; // Here's the problem!

Since Base's destructor is not virtual and b is a Base* pointing to a Derived object, delete b has undefined behaviour:

[In delete b], if the static type of the object to be deleted is different from its dynamic type, the static type shall be a base class of the dynamic type of the object to be deleted and the static type shall have a virtual destructor or the behavior is undefined.

In most implementations, the call to the destructor will be resolved like any non-virtual code, meaning that the destructor of the base class will be called but not the one of the derived class, resulting in a resources leak.

To sum up, always make base classes' destructors virtual when they're meant to be manipulated polymorphically.

If you want to prevent the deletion of an instance through a base class pointer, you can make the base class destructor protected and nonvirtual; by doing so, the compiler won't let you call delete on a base class pointer.

You can learn more about virtuality and virtual base class destructor in this article from Herb Sutter.

Convert from enum ordinal to enum type

I agree with most people that using ordinal is probably a bad idea. I usually solve this problem by giving the enum a private constructor that can take for example a DB value then create a static fromDbValue function similar to the one in Jan's answer.

public enum ReportTypeEnum {
    R1(1),
    R2(2),
    R3(3),
    R4(4),
    R5(5),
    R6(6),
    R7(7),
    R8(8);

    private static Logger log = LoggerFactory.getLogger(ReportEnumType.class);  
    private static Map<Integer, ReportTypeEnum> lookup;
    private Integer dbValue;

    private ReportTypeEnum(Integer dbValue) {
        this.dbValue = dbValue;
    }


    static {
        try {
            ReportTypeEnum[] vals = ReportTypeEnum.values();
            lookup = new HashMap<Integer, ReportTypeEnum>(vals.length);

            for (ReportTypeEnum  rpt: vals)
                lookup.put(rpt.getDbValue(), rpt);
         }
         catch (Exception e) {
             // Careful, if any exception is thrown out of a static block, the class
             // won't be initialized
             log.error("Unexpected exception initializing " + ReportTypeEnum.class, e);
         }
    }

    public static ReportTypeEnum fromDbValue(Integer dbValue) {
        return lookup.get(dbValue);
    }

    public Integer getDbValue() {
        return this.dbValue;
    }

}

Now you can change the order without changing the lookup and vice versa.

How do I copy a folder from remote to local using scp?

I don't know why but I was had to use local folder before source server directive . to make it work

scp -r . [email protected]:/usr/share/nginx/www/example.org/

How can building a heap be O(n) time complexity?

Lets suppose you have N elements in a heap. Then its height would be Log(N)

Now you want to insert another element, then the complexity would be : Log(N), we have to compare all the way UP to the root.

Now you are having N+1 elements & height = Log(N+1)

Using induction technique it can be proved that the complexity of insertion would be ?logi.

Now using

log a + log b = log ab

This simplifies to : ?logi=log(n!)

which is actually O(NlogN)

But

we are doing something wrong here, as in all the case we do not reach at the top. Hence while executing most of the times we may find that, we are not going even half way up the tree. Whence, this bound can be optimized to have another tighter bound by using mathematics given in answers above.

This realization came to me after a detail though & experimentation on Heaps.

How do I convert a datetime to date?

import time
import datetime

# use mktime to step by one day
# end - the last day, numdays - count of days to step back
def gen_dates_list(end, numdays):
  start = end - datetime.timedelta(days=numdays+1)
  end   = int(time.mktime(end.timetuple()))
  start = int(time.mktime(start.timetuple()))
  # 86400 s = 1 day
  return xrange(start, end, 86400)

# if you need reverse the list of dates
for dt in reversed(gen_dates_list(datetime.datetime.today(), 100)):
    print datetime.datetime.fromtimestamp(dt).date()

How to set only time part of a DateTime variable in C#

date = new DateTime(date.year, date.month, date.day, HH, MM, SS);

One line if in VB .NET

Just add Then:

If A = 1 Then A = 2

or:

If A = 1 Then _
    A = 2

phpmailer error "Could not instantiate mail function"

Check if sendmail is enabled, mostly if your server is provided by another company.

Tomcat request timeout

With Tomcat 7, you can add the StuckThreadDetectionValve which will enable you to identify threads that are "stuck". You can set-up the valve in the Context element of the applications where you want to do detecting:

<Context ...>
  ...
  <Valve 
    className="org.apache.catalina.valves.StuckThreadDetectionValve"
    threshold="60" />
  ...
</Context>

This would write a WARN entry into the tomcat log for any thread that takes longer than 60 seconds, which would enable you to identify the applications and ban them because they are faulty.

Based on the source code you may be able to write your own valve that attempts to stop the thread, however this would have knock on effects on the thread pool and there is no reliable way of stopping a thread in Java without the cooperation of that thread...

What is the inclusive range of float and double in Java?

Java's Double class has members containing the Min and Max value for the type.

2^-1074 <= x <= (2-2^-52)·2^1023 // where x is the double.

Check out the Min_VALUE and MAX_VALUE static final members of Double.

(some)People will suggest against using floating point types for things where accuracy and precision are critical because rounding errors can throw off calculations by measurable (small) amounts.

disable editing default value of text input

You can either use the readonly or the disabled attribute. Note that when disabled, the input's value will not be submitted when submitting the form.

<input id="price_to" value="price to" readonly="readonly">
<input id="price_to" value="price to" disabled="disabled">

NLS_NUMERIC_CHARACTERS setting for decimal

To know SESSION decimal separator, you can use following SQL command:

ALTER SESSION SET NLS_NUMERIC_CHARACTERS = ', ';

select SUBSTR(value,1,1) as "SEPARATOR"
      ,'using NLS-PARAMETER' as "Explanation"
  from nls_session_parameters
  where parameter = 'NLS_NUMERIC_CHARACTERS'

UNION ALL

select SUBSTR(0.5,1,1) as "SEPARATOR" 
      ,'using NUMBER IMPLICIT CASTING' as "Explanation"
  from DUAL;

The first SELECT command find NLS Parameter defined in NLS_SESSION_PARAMETERS table. The decimal separator is the first character of the returned value.

The second SELECT command convert IMPLICITELY the 0.5 rational number into a String using (by default) NLS_NUMERIC_CHARACTERS defined at session level.

The both command return same value.

I have already tested the same SQL command in PL/SQL script and this is always the same value COMMA or POINT that is displayed. Decimal Separator displayed in PL/SQL script is equal to what is displayed in SQL.

To test what I say, I have used following SQL commands:

ALTER SESSION SET NLS_NUMERIC_CHARACTERS = ', ';

select 'DECIMAL-SEPARATOR on CLIENT: (' || TO_CHAR(.5,) || ')' from dual;

DECLARE
    S VARCHAR2(10) := '?';
BEGIN

    select .5 INTO S from dual;

    DBMS_OUTPUT.PUT_LINE('DECIMAL-SEPARATOR in PL/SQL: (' || S || ')');
END;
/

The shorter command to know decimal separator is:

SELECT .5 FROM DUAL;

That return 0,5 if decimal separator is a COMMA and 0.5 if decimal separator is a POINT.

PHP: HTML: send HTML select option attribute in POST

You can use jquery function.

<form name='add'>
   <input type='text' name='stud_name' id="stud_name" value=""/>
   Age: <select name='age' id="age">
   <option value='1' stud_name='sre'>23</option>
   <option value='2' stud_name='sam'>24</option>
   <option value='5' stud_name='john'>25</option>
   </select>
   <input type='submit' name='submit'/>
</form>

jquery code :

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

<script>
    $(function() {
          $("#age").change(function(){
          var option = $('option:selected', this).attr('stud_name');
          $('#stud_name').val(option);
       });
    });
</script>

angular 2 sort and filter

A pipe takes in data as input and transforms it to a desired output. Add this pipe file:orderby.ts inside your /app folder .

orderby.ts

//The pipe class implements the PipeTransform interface's transform method that accepts an input value and an optional array of parameters and returns the transformed value.

import { Pipe,PipeTransform } from "angular2/core";

//We tell Angular that this is a pipe by applying the @Pipe decorator which we import from the core Angular library.

@Pipe({

  //The @Pipe decorator takes an object with a name property whose value is the pipe name that we'll use within a template expression. It must be a valid JavaScript identifier. Our pipe's name is orderby.

  name: "orderby"
})

export class OrderByPipe implements PipeTransform {
  transform(array:Array<any>, args?) {

    // Check if array exists, in this case array contains articles and args is an array that has 1 element : !id

    if(array) {

      // get the first element

      let orderByValue = args[0]
      let byVal = 1

      // check if exclamation point 

      if(orderByValue.charAt(0) == "!") {

        // reverse the array

        byVal = -1
        orderByValue = orderByValue.substring(1)
      }
      console.log("byVal",byVal);
      console.log("orderByValue",orderByValue);

      array.sort((a: any, b: any) => {
        if(a[orderByValue] < b[orderByValue]) {
          return -1*byVal;
        } else if (a[orderByValue] > b[orderByValue]) {
          return 1*byVal;
        } else {
          return 0;
        }
      });
      return array;
    }
    //
  }
}

In your component file (app.component.ts) import the pipe that you just added using: import {OrderByPipe} from './orderby';

Then, add *ngFor="#article of articles | orderby:'id'" inside your template if you want to sort your articles by id in ascending order or orderby:'!id'" in descending order.

We add parameters to a pipe by following the pipe name with a colon ( : ) and then the parameter value

We must list our pipe in the pipes array of the @Component decorator. pipes: [ OrderByPipe ] .

app.component.ts

import {Component, OnInit} from 'angular2/core';
import {OrderByPipe} from './orderby';

@Component({
    selector: 'my-app',
    template: `
      <h2>orderby-pipe by N2B</h2>
      <p *ngFor="#article of articles | orderby:'id'">
        Article title : {{article.title}}
      </p>
    `,
    pipes: [ OrderByPipe ]

})
export class AppComponent{
    articles:Array<any>
    ngOnInit(){
        this.articles = [
        {
            id: 1,
            title: "title1"
        },{
            id: 2,
            title: "title2",
        }]  
    }

}

More info here on my github and this post on my website

How to call external JavaScript function in HTML

If a <script> has a src then the text content of the element will be not be executed as JS (although it will appear in the DOM).

You need to use multiple script elements.

  1. a <script> to load the external script
  2. a <script> to hold your inline code (with the call to the function in the external script)

    scroll_messages();

How do you pull first 100 characters of a string in PHP

You could use substr, I guess:

$string2 = substr($string1, 0, 100);

or mb_substr for multi-byte strings:

$string2 = mb_substr($string1, 0, 100);

You could create a function wich uses this function and appends for instance '...' to indicate that it was shortened. (I guess there's allready a hundred similar replies when this is posted...)

Select value from list of tuples where condition

One solution to this would be a list comprehension, with pattern matching inside your tuple:

>>> mylist = [(25,7),(26,9),(55,10)]
>>> [age for (age,person_id) in mylist if person_id == 10]
[55]

Another way would be using map and filter:

>>> map( lambda (age,_): age, filter( lambda (_,person_id): person_id == 10, mylist) )
[55]

Query-string encoding of a Javascript Object

In ES7 you can write this in one line:

const serialize = (obj) => (Object.entries(obj).map(i => [i[0], encodeURIComponent(i[1])].join('=')).join('&'))

What is the difference between a database and a data warehouse?

A Data Warehousing (DW) is process for collecting and managing data from varied sources to provide meaningful business insights. A Data warehouse is typically used to connect and analyze business data from heterogeneous sources. The data warehouse is the core of the BI system which is built for data analysis and reporting.

Maven version with a property

Using a property for the version generates the following warning:

[WARNING]
[WARNING] Some problems were encountered while building the effective model for xxx.yyy.sandbox:Sandbox:war:0.1.0-SNAPSHOT
[WARNING] 'version' contains an expression but should be a constant. @ xxx.yyy.sandbox:Sandbox:${my.version}, C:\Users\xxx\development\gwtsandbox\pom.xml, line 8, column 14
[WARNING]
[WARNING] It is highly recommended to fix these problems because they threaten the stability of your build.
[WARNING]
[WARNING] For this reason, future Maven versions might no longer support building such malformed projects.
[WARNING]

If your problem is that you have to change the version in multiple places because you are switching versions, then the correct thing to do is to use the Maven Release Plugin that will do this for you automatically.

Using setTimeout to delay timing of jQuery actions

Try this:

function explode(){
  alert("Boom!");
}
setTimeout(explode, 2000);

How to check the value given is a positive or negative integer?

simply write:

if(values > 0){
//positive
}
else{
//negative
}

Find all elements with a certain attribute value in jquery

It's not called a tag; what you're looking for is called an html attribute.

$('div[imageId="imageN"]').each(function(i,el){
  $(el).html('changes');
  //do what ever you wish to this object :) 
});

Scheduling recurring task in Android

I realize this is an old question and has been answered but this could help someone. In your activity

private ScheduledExecutorService scheduleTaskExecutor;

In onCreate

  scheduleTaskExecutor = Executors.newScheduledThreadPool(5);

    //Schedule a task to run every 5 seconds (or however long you want)
    scheduleTaskExecutor.scheduleAtFixedRate(new Runnable() {
        @Override
        public void run() {
            // Do stuff here!

            runOnUiThread(new Runnable() {
                @Override
                public void run() {
                    // Do stuff to update UI here!
                    Toast.makeText(MainActivity.this, "Its been 5 seconds", Toast.LENGTH_SHORT).show();
                }
            });

        }
    }, 0, 5, TimeUnit.SECONDS); // or .MINUTES, .HOURS etc.

Selenium -- How to wait until page is completely loaded

3 answers, which you can combine:

  1. Set implicit wait immediately after creating the web driver instance:

    _ = driver.Manage().Timeouts().ImplicitWait;

    This will try to wait until the page is fully loaded on every page navigation or page reload.

  2. After page navigation, call JavaScript return document.readyState until "complete" is returned. The web driver instance can serve as JavaScript executor. Sample code:

    C#

    new WebDriverWait(driver, MyDefaultTimeout).Until(
    d => ((IJavaScriptExecutor) d).ExecuteScript("return document.readyState").Equals("complete"));
    

    Java

    new WebDriverWait(firefoxDriver, pageLoadTimeout).until(
          webDriver -> ((JavascriptExecutor) webDriver).executeScript("return document.readyState").equals("complete"));
    
  3. Check if the URL matches the pattern you expect.

How can I convert ArrayList<Object> to ArrayList<String>?

Using Java 8 lambda:

ArrayList<Object> obj = new ArrayList<>();
obj.add(1);
obj.add("Java");
obj.add(3.14);

ArrayList<String> list = new ArrayList<>();
obj.forEach((xx) -> list.add(String.valueOf(xx)));

Change mysql user password using command line

This works for me. Got solution from MYSQL webpage

In MySQL run below queries:

FLUSH PRIVILEGES;
ALTER USER 'root'@'localhost' IDENTIFIED BY 'New_Password';

CSS Progress Circle

What about that?

HTML

<div class="chart" id="graph" data-percent="88"></div>

Javascript

var el = document.getElementById('graph'); // get canvas

var options = {
    percent:  el.getAttribute('data-percent') || 25,
    size: el.getAttribute('data-size') || 220,
    lineWidth: el.getAttribute('data-line') || 15,
    rotate: el.getAttribute('data-rotate') || 0
}

var canvas = document.createElement('canvas');
var span = document.createElement('span');
span.textContent = options.percent + '%';

if (typeof(G_vmlCanvasManager) !== 'undefined') {
    G_vmlCanvasManager.initElement(canvas);
}

var ctx = canvas.getContext('2d');
canvas.width = canvas.height = options.size;

el.appendChild(span);
el.appendChild(canvas);

ctx.translate(options.size / 2, options.size / 2); // change center
ctx.rotate((-1 / 2 + options.rotate / 180) * Math.PI); // rotate -90 deg

//imd = ctx.getImageData(0, 0, 240, 240);
var radius = (options.size - options.lineWidth) / 2;

var drawCircle = function(color, lineWidth, percent) {
        percent = Math.min(Math.max(0, percent || 1), 1);
        ctx.beginPath();
        ctx.arc(0, 0, radius, 0, Math.PI * 2 * percent, false);
        ctx.strokeStyle = color;
        ctx.lineCap = 'round'; // butt, round or square
        ctx.lineWidth = lineWidth
        ctx.stroke();
};

drawCircle('#efefef', options.lineWidth, 100 / 100);
drawCircle('#555555', options.lineWidth, options.percent / 100);

and CSS

div {
    position:relative;
    margin:80px;
    width:220px; height:220px;
}
canvas {
    display: block;
    position:absolute;
    top:0;
    left:0;
}
span {
    color:#555;
    display:block;
    line-height:220px;
    text-align:center;
    width:220px;
    font-family:sans-serif;
    font-size:40px;
    font-weight:100;
    margin-left:5px;
}

http://jsfiddle.net/Aapn8/3410/

Basic code was taken from Simple PIE Chart http://rendro.github.io/easy-pie-chart/

Install numpy on python3.3 - Install pip for python3

The normal way to install Python libraries is with pip. Your way of installing it for Python 3.2 works because it's the system Python, and that's the way to install things for system-provided Pythons on Debian-based systems.

If your Python 3.3 is system-provided, you should probably use a similar command. Otherwise you should probably use pip.

I took my Python 3.3 installation, created a virtualenv and run pip install in it, and that seems to have worked as expected:

$ virtualenv-3.3 testenv
$ cd testenv
$ bin/pip install numpy
blablabl

$ bin/python3
Python 3.3.2 (default, Jun 17 2013, 17:49:21) 
[GCC 4.6.3] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import numpy
>>> 

Fragment onCreateView and onActivityCreated called twice

It looks to me like it's because you are instantiating your TabListener every time... so the system is recreating your fragment from the savedInstanceState and then you are doing it again in your onCreate.

You should wrap that in a if(savedInstanceState == null) so it only fires if there is no savedInstanceState.

Deserialize JSON with C#

Newtonsoft.JSON is a good solution for these kind of situations. Also Newtonsof.JSON is faster than others, such as JavaScriptSerializer, DataContractJsonSerializer.

In this sample, you can the following:

var jsonData = JObject.Parse("your JSON data here");

Then you can cast jsonData to JArray, and you can use a for loop to get data at each iteration.

Also, I want to add something:

for (int i = 0; (JArray)jsonData["data"].Count; i++)
{
    var data = jsonData[i - 1];
}

Working with dynamic object and using Newtonsoft serialize is a good choice.

Using setattr() in python

To add to the other answers, a common use case I have found for setattr() is when using configs. It is common to parse configs from a file (.ini file or whatever) into a dictionary. So you end up with something like:

configs = {'memory': 2.5, 'colour': 'red', 'charge': 0, ... }

If you want to then assign these configs to a class to be stored and passed around, you could do simple assignment:

MyClass.memory = configs['memory']
MyClass.colour = configs['colour']
MyClass.charge = configs['charge']
...

However, it is much easier and less verbose to loop over the configs, and setattr() like so:

for name, val in configs.items():
    setattr(MyClass, name, val)

As long as your dictionary keys have the proper names, this works very well and is nice and tidy.

*Note, the dict keys need to be strings as they will be the class object names.

Share link on Google+

No, you cannot. Google Plus has been discontinued. Clicking any link for any answer here brings me to this text:

Google+ is no longer available for consumer (personal) and brand accounts

From all of us on the Google+ team,

thank you for making Google+ such a special place.

There is one section that reads that the product is continued for "G Suite," but as of Feb., 2020, the chat and social service listed for G Suite is Hangouts, not Google+.

The format https://plus.google.com/share?url=YOUR_URL_HERE was documented at https://developers.google.com/+/web/share/, but this documentation has since been removed, probably because no part of Google+ continues in development. If you are feeling nostalgic, you can see what the API used to say with an Archive.org link.

Converting BigDecimal to Integer

You would call myBigDecimal.intValueExact() (or just intValue()) and it will even throw an exception if you would lose information. That returns an int but autoboxing takes care of that.

Getter and Setter?

In addition to the already great and respected answers in here, I would like to expand on PHP having no setters/getters.

PHP does not have getter and setter syntax. It provides subclassed or magic methods to allow "hooking" and overriding the property lookup process, as pointed out by Dave.

Magic allows us lazy programmers to do more with less code at a time at which we are actively engaged in a project and know it intimately, but usually at the expense of readability.

Performance Every unnecessary function, that results from forcing a getter/setter-like code-architecture in PHP, involves its own memory stack-frame upon invocation and is wasting CPU cycles.

Readability: The codebase incurs bloating code-lines, which impacts code-navigation as more LOC mean more scrolling,.

Preference: Personally, as my rule of thumb, I take the failure of static code analysis as a sign to avoid going down the magical road as long as obvious long-term benefits elude me at that time.

Fallacies:

A common argument is readability. For instance that $someobject->width is easier to read than $someobject->width(). However unlike a planet's circumference or width, which can be assumed to be static, an object's instance such as $someobject, which requires a width function, likely takes a measurement of the object's instance width.
Therefore readability increases mainly because of assertive naming-schemes and not by hiding the function away that outputs a given property-value.

__get / __set uses:

  • pre-validation and pre-sanitation of property values

  • strings e.g.

    "
    some {mathsobj1->generatelatex} multi
    line text {mathsobj1->latexoutput}
    with lots of variables for {mathsobj1->generatelatex}
     some reason
    "
    

    In this case generatelatex would adhere to a naming scheme of actionname + methodname

  • special, obvious cases

    $dnastringobj->homeobox($one_rememberable_parameter)->gattaca->findrelated()
    $dnastringobj->homeobox($one_rememberable_parameter)->gttccaatttga->findrelated()
    

Note: PHP chose not to implement getter/setter syntax. I am not claiming that getters/setter are generally bad.

Using `window.location.hash.includes` throws “Object doesn't support property or method 'includes'” in IE11

This question and its answers led me to my own solution (with help from SO), though some say you shouldn't tamper with native prototypes:

  // IE does not support .includes() so I'm making my own:
  String.prototype.doesInclude=function(needle){
    return this.substring(needle) != -1;
  }

Then I just replaced all .includes() with .doesInclude() and my problem was solved.

What is a regular expression for a MAC Address?

for PHP developer

filter_var($value, FILTER_VALIDATE_MAC)

Putting a simple if-then-else statement on one line

<execute-test-successful-condition> if <test> else <execute-test-fail-condition>

with your code-snippet it would become,

count = 0 if count == N else N + 1

Renaming a directory in C#

There is no difference between moving and renaming; you should simply call Directory.Move.

In general, if you're only doing a single operation, you should use the static methods in the File and Directory classes instead of creating FileInfo and DirectoryInfo objects.

For more advice when working with files and directories, see here.

Open source face recognition for Android

Here are some links that I found on face recognition libraries.

Image Identification links:

The type or namespace cannot be found (are you missing a using directive or an assembly reference?)

You need to add the following line:

using FootballLeagueSystem;

into your all your classes (MainMenu.cs, programme.cs, etc.) that use Login.

At the moment the compiler can't find the Login class.

Remote Linux server to remote linux server dir copy. How?

I would modify a previously suggested reply:

rsync -avlzp /path/to/sfolder [email protected]:/path/to/remote/dfolder

as follows:

-a (for archive) implies -rlptgoD so the l and p above are superfluous. I also like to include -H, which copies hard links. It is not part of -a by default because it's expensive. So now we have this:

rsync -aHvz /path/to/sfolder [email protected]:/path/to/remote/dfolder

You also have to be careful about trailing slashes. You probably want

rsync -aHvz /path/to/sfolder/ [email protected]:/path/to/remote/dfolder

if the desire is for the contents of the source "sfolder" to appear in the destination "dfolder". Without the trailing slash, an "sfolder" subdirectory would be created in the destination "dfolder".

How do you calculate log base 2 in Java for integers?

you can use the identity

            log[a]x
 log[b]x = ---------
            log[a]b

so this would be applicable for log2.

            log[10]x
 log[2]x = ----------
            log[10]2

just plug this into the java Math log10 method....

http://mathforum.org/library/drmath/view/55565.html

Django MEDIA_URL and MEDIA_ROOT

If you'r using python 3.0+ then configure your project as below

Setting

STATIC_DIR = BASE_DIR / 'static'
MEDIA_DIR = BASE_DIR / 'media'
MEDIA_ROOT = MEDIA_DIR
MEDIA_URL = '/media/'

Main Urls

from django.conf import settings
from django.conf.urls.static import static

urlspatterns=[
........
]+ static(settings.MEDIA_URL, document_root=settings.MEDIA_ROOT)

Rethrowing exceptions in Java without losing the stack trace

something like this

try 
{
  ...
}
catch (FooException e) 
{
  throw e;
}
catch (Exception e)
{
  ...
}

Python: Tuples/dictionaries as keys, select, sort

This type of data is efficiently pulled from a Trie-like data structure. It also allows for fast sorting. The memory efficiency might not be that great though.

A traditional trie stores each letter of a word as a node in the tree. But in your case your "alphabet" is different. You are storing strings instead of characters.

it might look something like this:

root:                Root
                     /|\
                    / | \
                   /  |  \     
fruit:       Banana Apple Strawberry
              / |      |     \
             /  |      |      \
color:     Blue Yellow Green  Blue
            /   |       |       \
           /    |       |        \
end:      24   100      12        0

see this link: trie in python

NoSuchMethodError in javax.persistence.Table.indexes()[Ljavax/persistence/Index

There are multiple JPA providers in your classpath. Or atleast in your Application server lib folder.

If you are using Maven Check for dependencies using command mentioned here https://stackoverflow.com/a/47474708/3333878

Then fix by removing/excluding unwanted dependency.

If you just have one dependecy in your classpath, then the application server's class loader might be the issue.

As JavaEE application servers like Websphere, Wildfly, Tomee etc., have their own implementations of JPA and other EE Standards, The Class loader might load it's own implementation instead of picking from your classpath in WAR/EAR file.

To avoid this, you can try below steps.

  1. Removing the offending jar in Application Servers library path. Proceed with Caution, as it might break other hosted applications.

In Tomee 1.7.5 Plume/ Web it will have bundled eclipselink-2.4.2 in the lib folder using JPA 2.0, but I had to use JPA 2.1 from org.hibernate:hibernate-core:5.1.17, so removed the eclipselink jar and added all related/ transitive dependencies from hibernate core.

  1. Add a shared library. and manually add jars to the app server's path. Websphere has this option.

  2. In Websphere, execution of class loader can be changed. so making it the application server's classpath to load last i.e, parent last and having your path load first. Can solve this.

Check if your appserver has above features, before proceeding with first point.

Ibm websphere References :

https://www.ibm.com/support/knowledgecenter/SSEQTP_9.0.5/com.ibm.websphere.base.doc/ae/trun_classload_server.html

https://www.ibm.com/support/pages/how-create-shared-library-and-associate-it-application-server-or-enterprise-application-websphere-application-server

Oracle "(+)" Operator

The (+) operator indicates an outer join. This means that Oracle will still return records from the other side of the join even when there is no match. For example if a and b are emp and dept and you can have employees unassigned to a department then the following statement will return details of all employees whether or not they've been assigned to a department.

select * from emp, dept where emp.dept_id=dept.dept_id(+)

So in short, removing the (+) may make a significance difference but you might not notice for a while depending on your data!

Bootstrap Carousel Full Screen

Simply Add 'carousel-item' class in place of item class.

Ruby - ignore "exit" in code

One hackish way to define an exit method in context:

class Bar; def exit; end; end 

This works because exit in the initializer will be resolved as self.exit1. In addition, this approach allows using the object after it has been created, as in: b = B.new.

But really, one shouldn't be doing this: don't have exit (or even puts) there to begin with.

(And why is there an "infinite" loop and/or user input in an intiailizer? This entire problem is primarily the result of poorly structured code.)


1 Remember Kernel#exit is only a method. Since Kernel is included in every Object, then it's merely the case that exit normally resolves to Object#exit. However, this can be changed by introducing an overridden method as shown - nothing fancy.

How can I get my Android device country code without using GPS?

You can simply use this code,

TelephonyManager tm = (TelephonyManager)this.getSystemService(Context.TELEPHONY_SERVICE);
String countryCodeValue = tm.getNetworkCountryIso();

This will return 'US' if your current connected network is in the United States. This works without a SIM card even.

How to define static property in TypeScript interface

You can define interface normally:

interface MyInterface {
    Name:string;
}

but you can't just do

class MyClass implements MyInterface {
    static Name:string; // typescript won't care about this field
    Name:string;         // and demand this one instead
}

To express that a class should follow this interface for its static properties you need a bit of trickery:

var MyClass: MyInterface;
MyClass = class {
    static Name:string; // if the class doesn't have that field it won't compile
}

You can even keep the name of the class, TypeScript (2.0) won't mind:

var MyClass: MyInterface;
MyClass = class MyClass {
    static Name:string; // if the class doesn't have that field it won't compile
}

If you want to inherit from many interfaces statically you'll have to merge them first into a new one:

interface NameInterface {
    Name:string;
}
interface AddressInterface {
    Address:string;
}
interface NameAndAddressInterface extends NameInterface, AddressInterface { }
var MyClass: NameAndAddressInterface;
MyClass = class MyClass {
    static Name:string; // if the class doesn't have that static field code won't compile
    static Address:string; // if the class doesn't have that static field code won't compile
}

Or if you don't want to name merged interface you can do:

interface NameInterface {
    Name:string;
}
interface AddressInterface {
    Address:string;
}
var MyClass: NameInterface & AddressInterface;
MyClass = class MyClass {
    static Name:string; // if the class doesn't have that static field code won't compile
    static Address:string; // if the class doesn't have that static field code won't compile
}

Working example

How to flip background image using CSS?

I found I way to flip only the background not whole element after seeing a clue to flip in Alex's answer. Thanks alex for your answer

HTML

<div class="prev"><a href="">Previous</a></div>
<div class="next"><a href="">Next</a></div>

CSS

.next a, .prev a {
    width:200px;
    background:#fff
}
 .next {
    float:left
}
 .prev {
    float:right
}
 .prev a:before, .next a:before {
    content:"";
    width:16px;
    height:16px;
    margin:0 5px 0 0;
    background:url(http://i.stack.imgur.com/ah0iN.png) no-repeat 0 0;
    display:inline-block 
}
 .next a:before {
    margin:0 0 0 5px;
    transform:scaleX(-1);
}

See example here http://jsfiddle.net/qngrf/807/

Read pdf files with php

You might want to also try this application http://pdfbox.apache.org/. A working example can be found at https://www.jinises.com

How to extract 1 screenshot for a video with ffmpeg at a given time?

Use the -ss option:

ffmpeg -ss 01:23:45 -i input -vframes 1 -q:v 2 output.jpg
  • For JPEG output use -q:v to control output quality. Full range is a linear scale of 1-31 where a lower value results in a higher quality. 2-5 is a good range to try.

  • The select filter provides an alternative method for more complex needs such as selecting only certain frame types, or 1 per 100, etc.

  • Placing -ss before the input will be faster. See FFmpeg Wiki: Seeking and this excerpt from the ffmpeg cli tool documentation:

-ss position (input/output)

When used as an input option (before -i), seeks in this input file to position. Note the in most formats it is not possible to seek exactly, so ffmpeg will seek to the closest seek point before position. When transcoding and -accurate_seek is enabled (the default), this extra segment between the seek point and position will be decoded and discarded. When doing stream copy or when -noaccurate_seek is used, it will be preserved.

When used as an output option (before an output filename), decodes but discards input until the timestamps reach position.

position may be either in seconds or in hh:mm:ss[.xxx] form.

Comparing two strings in C?

The name of the array indicates the starting address. Starting address of both namet2 and nameIt2 are different. So the equal to (==) operator checks whether the addresses are the same or not. For comparing two strings, a better way is to use strcmp(), or we can compare character by character using a loop.

Comparison between Corona, Phonegap, Titanium

For anybody interested in Titanium i must say that they don't have a very good documentation some classes, properties, methods are missing. But a lot is "documented" in their sample app the KitchenSink so it is not THAT bad.

How to execute a MySQL command from a shell script?

The core of the question has been answered several times already, I just thought I'd add that backticks (`s) have beaning in both shell scripting and SQL. If you need to use them in SQL for specifying a table or database name you'll need to escape them in the shell script like so:

mysql -p=password -u "root" -Bse "CREATE DATABASE \`${1}_database\`;
CREATE USER '$1'@'%' IDENTIFIED BY '$2';
GRANT ALL PRIVILEGES ON `${1}_database`.* TO '$1'@'%' WITH GRANT OPTION;"

Of course, generating SQL through concatenated user input (passed arguments) shouldn't be done unless you trust the user input.It'd be a lot more secure to put it in another scripting language with support for parameters / correctly escaping strings for insertion into MySQL.

Merge, update, and pull Git branches without using checkouts

You can clone the repo and do the merge in the new repo. On the same filesystem, this will hardlink rather than copy most of the data. Finish by pulling the results into the original repo.

Batch script to find and replace a string in text file without creating an extra output file for storing the modified file

@echo off 
    setlocal enableextensions disabledelayedexpansion

    set "search=%1"
    set "replace=%2"

    set "textFile=Input.txt"

    for /f "delims=" %%i in ('type "%textFile%" ^& break ^> "%textFile%" ') do (
        set "line=%%i"
        setlocal enabledelayedexpansion
        >>"%textFile%" echo(!line:%search%=%replace%!
        endlocal
    )

for /f will read all the data (generated by the type comamnd) before starting to process it. In the subprocess started to execute the type, we include a redirection overwritting the file (so it is emptied). Once the do clause starts to execute (the content of the file is in memory to be processed) the output is appended to the file.

Replace first occurrence of pattern in a string

public string ReplaceFirst(string text, string search, string replace)
{
  int pos = text.IndexOf(search);
  if (pos < 0)
  {
    return text;
  }
  return text.Substring(0, pos) + replace + text.Substring(pos + search.Length);
}

here is an Extension Method that could also work as well per VoidKing request

public static class StringExtensionMethods
{
    public static string ReplaceFirst(this string text, string search, string replace)
    {
      int pos = text.IndexOf(search);
      if (pos < 0)
      {
        return text;
      }
      return text.Substring(0, pos) + replace + text.Substring(pos + search.Length);
    }
}

Java8: sum values from specific field of the objects in a list

You can also collect with an appropriate summing collector like Collectors#summingInt(ToIntFunction)

Returns a Collector that produces the sum of a integer-valued function applied to the input elements. If no elements are present, the result is 0.

For example

Stream<Obj> filtered = list.stream().filter(o -> o.field > 10);
int sum = filtered.collect(Collectors.summingInt(o -> o.field));

How do I create a datetime in Python from milliseconds?

Bit heavy because of using pandas but works:

import pandas as pd
pd.to_datetime(msec_from_java, unit='ms').to_pydatetime()

How do Python functions handle the types of the parameters that you pass in?

You don't specify a type. The method will only fail (at runtime) if it tries to access attributes that are not defined on the parameters that are passed in.

So this simple function:

def no_op(param1, param2):
    pass

... will not fail no matter what two args are passed in.

However, this function:

def call_quack(param1, param2):
    param1.quack()
    param2.quack()

... will fail at runtime if param1 and param2 do not both have callable attributes named quack.

'Use of Unresolved Identifier' in Swift

I got this error for Mantle Framework in my Objective-Swift Project. What i tried is ,

  1. Check if import is there in Bridging-Header.h file
  2. Change the Target Membership for Framework in Mantle.h file as shown in below screenshot.

Toggle between Private Membership first build the project , end up with errors. Then build the project with Public Membership for all the frameworks appeared for Mantle.h file, you must get success.

It is just a bug of building with multiple framework in Objective-C Swift project.

enter image description here

How to make a promise from setTimeout

Update (2017)

Here in 2017, Promises are built into JavaScript, they were added by the ES2015 spec (polyfills are available for outdated environments like IE8-IE11). The syntax they went with uses a callback you pass into the Promise constructor (the Promise executor) which receives the functions for resolving/rejecting the promise as arguments.

First, since async now has a meaning in JavaScript (even though it's only a keyword in certain contexts), I'm going to use later as the name of the function to avoid confusion.

Basic Delay

Using native promises (or a faithful polyfill) it would look like this:

function later(delay) {
    return new Promise(function(resolve) {
        setTimeout(resolve, delay);
    });
}

Note that that assumes a version of setTimeout that's compliant with the definition for browsers where setTimeout doesn't pass any arguments to the callback unless you give them after the interval (this may not be true in non-browser environments, and didn't used to be true on Firefox, but is now; it's true on Chrome and even back on IE8).

Basic Delay with Value

If you want your function to optionally pass a resolution value, on any vaguely-modern browser that allows you to give extra arguments to setTimeout after the delay and then passes those to the callback when called, you can do this (current Firefox and Chrome; IE11+, presumably Edge; not IE8 or IE9, no idea about IE10):

function later(delay, value) {
    return new Promise(function(resolve) {
        setTimeout(resolve, delay, value); // Note the order, `delay` before `value`
        /* Or for outdated browsers that don't support doing that:
        setTimeout(function() {
            resolve(value);
        }, delay);
        Or alternately:
        setTimeout(resolve.bind(null, value), delay);
        */
    });
}

If you're using ES2015+ arrow functions, that can be more concise:

function later(delay, value) {
    return new Promise(resolve => setTimeout(resolve, delay, value));
}

or even

const later = (delay, value) =>
    new Promise(resolve => setTimeout(resolve, delay, value));

Cancellable Delay with Value

If you want to make it possible to cancel the timeout, you can't just return a promise from later, because promises can't be cancelled.

But we can easily return an object with a cancel method and an accessor for the promise, and reject the promise on cancel:

const later = (delay, value) => {
    let timer = 0;
    let reject = null;
    const promise = new Promise((resolve, _reject) => {
        reject = _reject;
        timer = setTimeout(resolve, delay, value);
    });
    return {
        get promise() { return promise; },
        cancel() {
            if (timer) {
                clearTimeout(timer);
                timer = 0;
                reject();
                reject = null;
            }
        }
    };
};

Live Example:

_x000D_
_x000D_
const later = (delay, value) => {_x000D_
    let timer = 0;_x000D_
    let reject = null;_x000D_
    const promise = new Promise((resolve, _reject) => {_x000D_
        reject = _reject;_x000D_
        timer = setTimeout(resolve, delay, value);_x000D_
    });_x000D_
    return {_x000D_
        get promise() { return promise; },_x000D_
        cancel() {_x000D_
            if (timer) {_x000D_
                clearTimeout(timer);_x000D_
                timer = 0;_x000D_
                reject();_x000D_
                reject = null;_x000D_
            }_x000D_
        }_x000D_
    };_x000D_
};_x000D_
_x000D_
const l1 = later(100, "l1");_x000D_
l1.promise_x000D_
  .then(msg => { console.log(msg); })_x000D_
  .catch(() => { console.log("l1 cancelled"); });_x000D_
_x000D_
const l2 = later(200, "l2");_x000D_
l2.promise_x000D_
  .then(msg => { console.log(msg); })_x000D_
  .catch(() => { console.log("l2 cancelled"); });_x000D_
setTimeout(() => {_x000D_
  l2.cancel();_x000D_
}, 150);
_x000D_
_x000D_
_x000D_


Original Answer from 2014

Usually you'll have a promise library (one you write yourself, or one of the several out there). That library will usually have an object that you can create and later "resolve," and that object will have a "promise" you can get from it.

Then later would tend to look something like this:

function later() {
    var p = new PromiseThingy();
    setTimeout(function() {
        p.resolve();
    }, 2000);

    return p.promise(); // Note we're not returning `p` directly
}

In a comment on the question, I asked:

Are you trying to create your own promise library?

and you said

I wasn't but I guess now that's actually what I was trying to understand. That how a library would do it

To aid that understanding, here's a very very basic example, which isn't remotely Promises-A compliant: Live Copy

<!DOCTYPE html>
<html>
<head>
<meta charset=utf-8 />
<title>Very basic promises</title>
</head>
<body>
  <script>
    (function() {

      // ==== Very basic promise implementation, not remotely Promises-A compliant, just a very basic example
      var PromiseThingy = (function() {

        // Internal - trigger a callback
        function triggerCallback(callback, promise) {
          try {
            callback(promise.resolvedValue);
          }
          catch (e) {
          }
        }

        // The internal promise constructor, we don't share this
        function Promise() {
          this.callbacks = [];
        }

        // Register a 'then' callback
        Promise.prototype.then = function(callback) {
          var thispromise = this;

          if (!this.resolved) {
            // Not resolved yet, remember the callback
            this.callbacks.push(callback);
          }
          else {
            // Resolved; trigger callback right away, but always async
            setTimeout(function() {
              triggerCallback(callback, thispromise);
            }, 0);
          }
          return this;
        };

        // Our public constructor for PromiseThingys
        function PromiseThingy() {
          this.p = new Promise();
        }

        // Resolve our underlying promise
        PromiseThingy.prototype.resolve = function(value) {
          var n;

          if (!this.p.resolved) {
            this.p.resolved = true;
            this.p.resolvedValue = value;
            for (n = 0; n < this.p.callbacks.length; ++n) {
              triggerCallback(this.p.callbacks[n], this.p);
            }
          }
        };

        // Get our underlying promise
        PromiseThingy.prototype.promise = function() {
          return this.p;
        };

        // Export public
        return PromiseThingy;
      })();

      // ==== Using it

      function later() {
        var p = new PromiseThingy();
        setTimeout(function() {
          p.resolve();
        }, 2000);

        return p.promise(); // Note we're not returning `p` directly
      }

      display("Start " + Date.now());
      later().then(function() {
        display("Done1 " + Date.now());
      }).then(function() {
        display("Done2 " + Date.now());
      });

      function display(msg) {
        var p = document.createElement('p');
        p.innerHTML = String(msg);
        document.body.appendChild(p);
      }
    })();
  </script>
</body>
</html>

How to limit the number of selected checkboxes?

Working DEMO

Try this

var theCheckboxes = $(".pricing-levels-3 input[type='checkbox']");
theCheckboxes.click(function()
{
    if (theCheckboxes.filter(":checked").length > 3)
        $(this).removeAttr("checked");
});

using mailto to send email with an attachment

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

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

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

Check if TextBox is empty and return MessageBox?

Try this condition instead:

if (string.IsNullOrWhiteSpace(MaterialTextBox.Text)) {
    // Message box
}

This will take care of some strings that only contain whitespace characters and you won't have to deal with string equality which can sometimes be tricky

Jquery - How to get the style display attribute "none / block"

My answer

/**
 * Display form to reply comment
 */
function displayReplyForm(commentId) {
    var replyForm = $('#reply-form-' + commentId);
    if (replyForm.css('display') == 'block') { // Current display
        replyForm.css('display', 'none');
    } else { // Hide reply form
        replyForm.css('display', 'block');
    }
}

JavaScript: IIF like statement

'<option value="' + col + '"'+ (col === "screwdriver" ? " selected " : "") +'>Very roomy</option>';

Fatal error: Allowed memory size of 134217728 bytes exhausted (tried to allocate 32 bytes)

Well try ini_set('memory_limit', '256M');

134217728 bytes = 128 MB

Or rewrite the code to consume less memory.

jquery .on() method with load event

As the other have mentioned, the load event does not bubble. Instead you can manually trigger a load-like event with a custom event:

$('#item').on('namespace/onload', handleOnload).trigger('namespace/onload')

If your element is already listening to a change event:

$('#item').on('change', handleChange).trigger('change')

I find this works well. Though, I stick to custom events to be more explicit and avoid side effects.

How to make RatingBar to show five stars

If you are wrapping the RatingBar inside a ConstraintLayout with match_constraint for its width, the editor preview is going to show a number of stars proportional to its actual width, no matter what if you set android:numStars property. Use wrap_content to get the correct preview:

<RatingBar android:id="@+id/myRatingBar"
           android:layout_width="wrap_content"
           android:layout_height="wrap_content"
           android:layout_marginStart="48dp"
           android:layout_marginEnd="48dp"
           android:numStars="5"
           app:layout_constraintEnd_toEndOf="parent"
           app:layout_constraintStart_toStartOf="parent"
           app:layout_constraintTop_toBottomOf="parent" />

Logo image and H1 heading on the same line

Check this.

 .header{width:100%;
    }

    .header img{ width: 20%; //or whatever width you like to have

    }

    .header h1{

    display:inline; //It will take rest of space which left by logo.
}

How can I copy a file on Unix using C?

There is no need to either call non-portable APIs like sendfile, or shell out to external utilities. The same method that worked back in the 70s still works now:

#include <fcntl.h>
#include <unistd.h>
#include <errno.h>

int cp(const char *to, const char *from)
{
    int fd_to, fd_from;
    char buf[4096];
    ssize_t nread;
    int saved_errno;

    fd_from = open(from, O_RDONLY);
    if (fd_from < 0)
        return -1;

    fd_to = open(to, O_WRONLY | O_CREAT | O_EXCL, 0666);
    if (fd_to < 0)
        goto out_error;

    while (nread = read(fd_from, buf, sizeof buf), nread > 0)
    {
        char *out_ptr = buf;
        ssize_t nwritten;

        do {
            nwritten = write(fd_to, out_ptr, nread);

            if (nwritten >= 0)
            {
                nread -= nwritten;
                out_ptr += nwritten;
            }
            else if (errno != EINTR)
            {
                goto out_error;
            }
        } while (nread > 0);
    }

    if (nread == 0)
    {
        if (close(fd_to) < 0)
        {
            fd_to = -1;
            goto out_error;
        }
        close(fd_from);

        /* Success! */
        return 0;
    }

  out_error:
    saved_errno = errno;

    close(fd_from);
    if (fd_to >= 0)
        close(fd_to);

    errno = saved_errno;
    return -1;
}

Is it possible to append Series to rows of DataFrame without making a list first?

Maybe an easier way would be to add the pandas.Series into the pandas.DataFrame with ignore_index=True argument to DataFrame.append(). Example -

DF = DataFrame()
for sample,data in D_sample_data.items():
    SR_row = pd.Series(data.D_key_value)
    DF = DF.append(SR_row,ignore_index=True)

Demo -

In [1]: import pandas as pd

In [2]: df = pd.DataFrame([[1,2],[3,4]],columns=['A','B'])

In [3]: df
Out[3]:
   A  B
0  1  2
1  3  4

In [5]: s = pd.Series([5,6],index=['A','B'])

In [6]: s
Out[6]:
A    5
B    6
dtype: int64

In [36]: df.append(s,ignore_index=True)
Out[36]:
   A  B
0  1  2
1  3  4
2  5  6

Another issue in your code is that DataFrame.append() is not in-place, it returns the appended dataframe, you would need to assign it back to your original dataframe for it to work. Example -

DF = DF.append(SR_row,ignore_index=True)

To preserve the labels, you can use your solution to include name for the series along with assigning the appended DataFrame back to DF. Example -

DF = DataFrame()
for sample,data in D_sample_data.items():
    SR_row = pd.Series(data.D_key_value,name=sample)
    DF = DF.append(SR_row)
DF.head()

How do I delete multiple rows with different IDs?

Delete from BA_CITY_MASTER where CITY_NAME in (select CITY_NAME from BA_CITY_MASTER group by CITY_NAME having count(CITY_NAME)>1);

How does JPA orphanRemoval=true differ from the ON DELETE CASCADE DML clause

@GaryK answer is absolutely great, I've spent an hour looking for an explanation orphanRemoval = true vs CascadeType.REMOVE and it helped me understand.

Summing up: orphanRemoval = true works identical as CascadeType.REMOVE ONLY IF we deleting object (entityManager.delete(object)) and we want the childs objects to be removed as well.

In completely different sitiuation, when we fetching some data like List<Child> childs = object.getChilds() and then remove a child (entityManager.remove(childs.get(0)) using orphanRemoval=true will cause that entity corresponding to childs.get(0) will be deleted from database.

What is PEP8's E128: continuation line under-indented for visual indent?

This goes also for statements like this (auto-formatted by PyCharm):

    return combine_sample_generators(sample_generators['train']), \
           combine_sample_generators(sample_generators['dev']), \
           combine_sample_generators(sample_generators['test'])

Which will give the same style-warning. In order to get rid of it I had to rewrite it to:

    return \
        combine_sample_generators(sample_generators['train']), \
        combine_sample_generators(sample_generators['dev']), \
        combine_sample_generators(sample_generators['test'])

How do I get the HTML code of a web page in PHP?

include_once('simple_html_dom.php');
$url="http://stackoverflow.com/questions/ask";
$html = file_get_html($url);

You can get the whole HTML code as an array (parsed form) using this code Download the 'simple_html_dom.php' file here http://sourceforge.net/projects/simplehtmldom/files/simple_html_dom.php/download

get number of columns of a particular row in given excel using Java

/** Count max number of nonempty cells in sheet rows */
private int getColumnsCount(XSSFSheet xssfSheet) {
    int result = 0;
    Iterator<Row> rowIterator = xssfSheet.iterator();
    while (rowIterator.hasNext()) {
        Row row = rowIterator.next();
        List<Cell> cells = new ArrayList<>();
        Iterator<Cell> cellIterator = row.cellIterator();
        while (cellIterator.hasNext()) {
            cells.add(cellIterator.next());
        }
        for (int i = cells.size(); i >= 0; i--) {
            Cell cell = cells.get(i-1);
            if (cell.toString().trim().isEmpty()) {
                cells.remove(i-1);
            } else {
                result = cells.size() > result ? cells.size() : result;
                break;
            }
        }
    }
    return result;
}

is there any IE8 only css hack?

Use media queries to separate each browser:

/* IE6/7 uses media, */
@media, { 
        .dude { color: green; } 
        .gal { color: red; }
} 

/* IE8 uses \0 */
@media all\0 { 
        .dude { color: brown; } 
        .gal { color: orange; }
} 

/* IE9 uses \9 */
@media all and (monochrome:0) { 
          .dude { color: yellow\9; } 
          .gal { color: blue\9; }
} 

/* IE10 and IE11 both use -ms-high-contrast */
@media all and (-ms-high-contrast:none)
 {
 .foo { color: green } /* IE10 */
 *::-ms-backdrop, .foo { color: red } /* IE11 */
 }

References

Warp \ bend effect on a UIView?

What you show looks like a mesh warp. That would be straightforward using OpenGL, but "straightforward OpenGL" is like straightforward rocket science.

I wrote an iOS app for my company called Face Dancerthat's able to do 60 fps mesh warp animations of video from the built-in camera using OpenGL, but it was a lot of work. (It does funhouse mirror type changes to faces - think "fat booth" live, plus lots of other effects.)

SQL Server: how to create a stored procedure

In T-SQL stored procedures for input parameters explicit 'in' keyword is not required and for output parameters an explicit 'Output' keyword is required. The query in question can be written as:

CREATE PROCEDURE dept_count 
    (
    -- Add input and output parameters for the stored procedure here
    @dept_name varchar(20), --Input parameter 
    @d_count int OUTPUT     -- Output parameter declared with the help of OUTPUT/OUT keyword
    ) 
AS
BEGIN
    -- SET NOCOUNT ON added to prevent extra result sets from
    -- interfering with SELECT statements.
    SET NOCOUNT ON;

     -- Statements for procedure here
    SELECT @d_count = count(*)
    from instructor
      where instructor.dept_name=@dept_name

END
GO

and to execute above procedure we can write as:

Declare @dept_name varchar(20), -- Declaring the variable to collect the dept_name
        @d_count int            -- Declaring the variable to collect the d_count 
SET @dept_name = 'Test'

Execute  dept_count @dept_name,@d_count output
SELECT   @d_count               -- "Select" Statement is used to show the output 

Is there a way to automatically build the package.json file for Node.js projects

npm init

to create the package.json file and then you use

ls node_modules/ | xargs npm install --save

to fill in the modules you have in the node_modules folder.

Edit: @paldepind pointed out that the second command is redundant because npm init now automatically adds what you have in your node_modules/ folder. I don't know if this has always been the case, but now at least, it works without the second command.

getting the error: expected identifier or ‘(’ before ‘{’ token

{
int main(void);

should be

int main(void)
{

Then I let you fix the next compilation errors of your program...

What is PostgreSQL equivalent of SYSDATE from Oracle?

The following functions are available to obtain the current date and/or time in PostgreSQL:

CURRENT_TIME

CURRENT_DATE

CURRENT_TIMESTAMP

Example

SELECT CURRENT_TIME;
08:05:18.864750+05:30

SELECT CURRENT_DATE;
2020-05-14

SELECT CURRENT_TIMESTAMP;
2020-05-14 08:04:51.290498+05:30

postgresql docs

PHP - Redirect and send data via POST

Yes, you can do this in PHP e.g. in

Silex or Symfony3

using subrequest

$postParams = array(
    'email' => $request->get('email'),
    'agree_terms' => $request->get('agree_terms'),
);

$subRequest = Request::create('/register', 'POST', $postParams);
return $app->handle($subRequest, HttpKernelInterface::SUB_REQUEST, false);

Swift Bridging Header import issue

Set Precompile Bridging Header to No fix the problem for me.

How to set the UITableView Section title programmatically (iPhone/iPad)?

Nothing wrong with the other answers but this one offers a non-programmatic solution that may be useful in situations where one has a small static table. The benefit is that one can organize the localizations using the storyboard. One may continue to export localizations from Xcode via XLIFF files. Xcode 9 also has several new tools to make localizations easier.

(original)

I had a similar requirement. I had a static table with static cells in my Main.storyboard(Base). To localize section titles using .string files e.g. Main.strings(German) just select the section in storyboard and note the Object ID

Object ID

Afterwards go to your string file, in my case Main.strings(German) and insert the translation like:

"MLo-jM-tSN.headerTitle" = "Localized section title";

Additional Resources:

EditText, clear focus on touch outside

You've probably found the answer to this problem already but I've been looking on how to solve this and still can't really find exactly what I was looking for so I figured I'd post it here.

What I did was the following (this is very generalized, purpose is to give you an idea of how to proceed, copying and pasting all the code will not work O:D ):

First have the EditText and any other views you want in your program wrapped by a single view. In my case I used a LinearLayout to wrap everything.

<LinearLayout 
  xmlns:android="http://schemas.android.com/apk/res/android"
  android:id="@+id/mainLinearLayout">
 <EditText
  android:id="@+id/editText"/>
 <ImageView
  android:id="@+id/imageView"/>
 <TextView
  android:id="@+id/textView"/>
 </LinearLayout>

Then in your code you have to set a Touch Listener to your main LinearLayout.

final EditText searchEditText = (EditText) findViewById(R.id.editText);
mainLinearLayout.setOnTouchListener(new View.OnTouchListener() {

        @Override
        public boolean onTouch(View v, MotionEvent event) {
            // TODO Auto-generated method stub
            if(searchEditText.isFocused()){
                if(event.getY() >= 72){
                    //Will only enter this if the EditText already has focus
                    //And if a touch event happens outside of the EditText
                    //Which in my case is at the top of my layout
                    //and 72 pixels long
                    searchEditText.clearFocus();
                    InputMethodManager imm = (InputMethodManager) v.getContext().getSystemService(Context.INPUT_METHOD_SERVICE);
                    imm.hideSoftInputFromWindow(v.getWindowToken(), 0);
                }
            }
            Toast.makeText(getBaseContext(), "Clicked", Toast.LENGTH_SHORT).show();
            return false;
        }
    });

I hope this helps some people. Or at least helps them start solving their problem.

How do you find all subclasses of a given class in Java?

Don't forget that the generated Javadoc for a class will include a list of known subclasses (and for interfaces, known implementing classes).

Rename specific column(s) in pandas

A much faster implementation would be to use list-comprehension if you need to rename a single column.

df.columns = ['log(gdp)' if x=='gdp' else x for x in df.columns]

If the need arises to rename multiple columns, either use conditional expressions like:

df.columns = ['log(gdp)' if x=='gdp' else 'cap_mod' if x=='cap' else x for x in df.columns]

Or, construct a mapping using a dictionary and perform the list-comprehension with it's get operation by setting default value as the old name:

col_dict = {'gdp': 'log(gdp)', 'cap': 'cap_mod'}   ## key?old name, value?new name

df.columns = [col_dict.get(x, x) for x in df.columns]

Timings:

%%timeit
df.rename(columns={'gdp':'log(gdp)'}, inplace=True)
10000 loops, best of 3: 168 µs per loop

%%timeit
df.columns = ['log(gdp)' if x=='gdp' else x for x in df.columns]
10000 loops, best of 3: 58.5 µs per loop

Pytesseract : "TesseractNotFound Error: tesseract is not installed or it's not in your path", how do I fix this?

For Windows Only

1 - You need to have Tesseract OCR installed on your computer.

get it from here. https://github.com/UB-Mannheim/tesseract/wiki

Download the suitable version.

2 - Add Tesseract path to your System Environment. i.e. Edit system variables.

3 - Run pip install pytesseract and pip install tesseract

4 - Add this line to your python script every time

pytesseract.pytesseract.tesseract_cmd = 'C:/OCR/Tesseract-OCR/tesseract.exe'  # your path may be different

5 - Run the code.

Javascript, viewing [object HTMLInputElement]

When you get a value from client make and that a value for example.

var current_text = document.getElementById('user_text').value;
        var http = new XMLHttpRequest();
        http.onreadystatechange = function () {

            if (http.readyState == 4 &&  http.status == 200 ){
                var response = http.responseText;
              document.getElementById('server_response').value = response;
                console.log(response.value);


            }

How to turn on line numbers in IDLE?

As @StahlRat already answered. I would like to add another method for it. There is extension pack for Python Default idle editor Python Extensions Package.

how to make a cell of table hyperlink

Try this:

HTML:

<table width="200" border="1" class="table">
    <tr>
        <td><a href="#">&nbsp;</a></td>
        <td>&nbsp;</td>
        <td>&nbsp;</td>
    </tr>
</table>

CSS:

.table a
{
    display:block;
    text-decoration:none;
}

I hope it will work fine.

Load content with ajax in bootstrap modal

Here is how I solved the issue, might be useful to some:

Ajax modal doesn't seem to be available with boostrap 2.1.1

So I ended up coding it myself:

$('[data-toggle="modal"]').click(function(e) {
  e.preventDefault();
  var url = $(this).attr('href');
  //var modal_id = $(this).attr('data-target');
  $.get(url, function(data) {
      $(data).modal();
  });
});

Example of a link that calls a modal:

<a href="{{ path('ajax_get_messages', { 'superCategoryID': 6, 'sex': sex }) }}" data-toggle="modal">
    <img src="{{ asset('bundles/yopyourownpoet/images/messageCategories/BirthdaysAnniversaries.png') }}" alt="Birthdays" height="120" width="109"/>
</a>

I now send the whole modal markup through ajax.

Credits to drewjoh

SQL Plus change current directory

With Oracle's new SQLcl there is a cd command now and accompanying pwd. SQLcl can be downloaded here: http://www.oracle.com/technetwork/developer-tools/sqlcl/overview/index.html

Here's a quick example:

SQL>pwd
/Users/klrice/
NOT_SAFE>!ls *.sql
db_awr.sql  emp.sql     img.sql     jeff.sql    orclcode.sql    test.sql
db_info.sql fn.sql      iot.sql     login.sql   rmoug.sql

SQL>cd sql
SQL>!ls *.sql
003.sql             demo_worksheet_name.sql     poll_so_stats.sql
1.sql               dual.sql            print_updates.sql

SQL>

Where can I find the error logs of nginx, using FastCGI and Django?

Type this command in the terminal:

sudo cat /var/log/nginx/error.log

Group array items using object

First, in JavaScript it's generally not a good idea to iterate over arrays using for ... in. See Why is using "for...in" with array iteration a bad idea? for details.

So you might try something like this:

var groups = {};
for (var i = 0; i < myArray.length; i++) {
  var groupName = myArray[i].group;
  if (!groups[groupName]) {
    groups[groupName] = [];
  }
  groups[groupName].push(myArray[i].color);
}
myArray = [];
for (var groupName in groups) {
  myArray.push({group: groupName, color: groups[groupName]});
}

Using the intermediary groups object here helps speed things up because it allows you to avoid nesting loops to search through the arrays. Also, because groups is an object (rather than an array) iterating over it using for ... in is appropriate.

Addendum

FWIW, if you want to avoid duplicate color entries in the resulting arrays you could add an if statement above the line groups[groupName].push(myArray[i].color); to guard against duplicates. Using jQuery it would look like this;

if (!$.inArray(myArray[i].color, groups[groupName])) {
  groups[groupName].push(myArray[i].color);
}

Without jQuery you may want to add a function that does the same thing as jQuery's inArray:

Array.prototype.contains = function(value) {
  for (var i = 0; i < this.length; i++) {
    if (this[i] === value)
      return true;
  }
  return false;
}

and then use it like this:

if (!groups[groupName].contains(myArray[i].color)) {
  groups[groupName].push(myArray[i].color);
}

Note that in either case you are going to slow things down a bit due to all the extra iteration, so if you don't need to avoid duplicate color entries in the result arrays I would recommend avoiding this extra code. There

Do sessions really violate RESTfulness?

First of all, REST is not a religion and should not be approached as such. While there are advantages to RESTful services, you should only follow the tenets of REST as far as they make sense for your application.

That said, authentication and client side state do not violate REST principles. While REST requires that state transitions be stateless, this is referring to the server itself. At the heart, all of REST is about documents. The idea behind statelessness is that the SERVER is stateless, not the clients. Any client issuing an identical request (same headers, cookies, URI, etc) should be taken to the same place in the application. If the website stored the current location of the user and managed navigation by updating this server side navigation variable, then REST would be violated. Another client with identical request information would be taken to a different location depending on the server-side state.

Google's web services are a fantastic example of a RESTful system. They require an authentication header with the user's authentication key to be passed upon every request. This does violate REST principles slightly, because the server is tracking the state of the authentication key. The state of this key must be maintained and it has some sort of expiration date/time after which it no longer grants access. However, as I mentioned at the top of my post, sacrifices must be made to allow an application to actually work. That said, authentication tokens must be stored in a way that allows all possible clients to continue granting access during their valid times. If one server is managing the state of the authentication key to the point that another load balanced server cannot take over fulfilling requests based on that key, you have started to really violate the principles of REST. Google's services ensure that, at any time, you can take an authentication token you were using on your phone against load balance server A and hit load balance server B from your desktop and still have access to the system and be directed to the same resources if the requests were identical.

What it all boils down to is that you need to make sure your authentication tokens are validated against a backing store of some sort (database, cache, whatever) to ensure that you preserve as many of the REST properties as possible.

I hope all of that made sense. You should also check out the Constraints section of the wikipedia article on Representational State Transfer if you haven't already. It is particularly enlightening with regard to what the tenets of REST are actually arguing for and why.

Force git stash to overwrite added files

TL;DR:

git checkout HEAD path/to/file
git stash apply

Long version:

You get this error because of the uncommited changes that you want to overwrite. Undo these changes with git checkout HEAD. You can undo changes to a specific file with git checkout HEAD path/to/file. After removing the cause of the conflict, you can apply as usual.

Wait until page is loaded with Selenium WebDriver for Python

The webdriver will wait for a page to load by default via .get() method.

As you may be looking for some specific element as @user227215 said, you should use WebDriverWait to wait for an element located in your page:

from selenium import webdriver
from selenium.webdriver.support.ui import WebDriverWait
from selenium.webdriver.support import expected_conditions as EC
from selenium.webdriver.common.by import By
from selenium.common.exceptions import TimeoutException

browser = webdriver.Firefox()
browser.get("url")
delay = 3 # seconds
try:
    myElem = WebDriverWait(browser, delay).until(EC.presence_of_element_located((By.ID, 'IdOfMyElement')))
    print "Page is ready!"
except TimeoutException:
    print "Loading took too much time!"

I have used it for checking alerts. You can use any other type methods to find the locator.

EDIT 1:

I should mention that the webdriver will wait for a page to load by default. It does not wait for loading inside frames or for ajax requests. It means when you use .get('url'), your browser will wait until the page is completely loaded and then go to the next command in the code. But when you are posting an ajax request, webdriver does not wait and it's your responsibility to wait an appropriate amount of time for the page or a part of page to load; so there is a module named expected_conditions.

Find non-ASCII characters in varchar columns using SQL Server

To find which field has invalid characters:

SELECT * FROM Staging.APARMRE1 FOR XML AUTO, TYPE

You can test it with this query:

SELECT top 1 'char 31: '+char(31)+' (hex 0x1F)' field
from sysobjects
FOR XML AUTO, TYPE

The result will be:

Msg 6841, Level 16, State 1, Line 3 FOR XML could not serialize the data for node 'field' because it contains a character (0x001F) which is not allowed in XML. To retrieve this data using FOR XML, convert it to binary, varbinary or image data type and use the BINARY BASE64 directive.

It is very useful when you write xml files and get error of invalid characters when validate it.

How to access POST form fields

Given some form:

<form action='/somepath' method='post'>
   <input type='text' name='name'></input>
</form>

Using express

app.post('/somepath', function(req, res) {

    console.log(JSON.stringify(req.body));

    console.log('req.body.name', req.body['name']);
});

Output:

{"name":"x","description":"x"}
req.param.name x

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

Careful as target might not work with all browsers, it works well with Chrome, but I reckon Firefox (or IE/Edge, can't remember) is a bit different and uses srcElement. I usually do something like

var t = ev.srcElement || ev.target;

thus leading to

$(document).ready(function() {
    $("a").click(function(ev) {
        // get target depending on what API's in use
        var t = ev.srcElement || ev.target;

        alert(t.id+" and "+$(t).attr('class'));
    });
});

Thx for the nice answers!

JQuery Calculate Day Difference in 2 date textboxes

Number of days calculation between two dates.

    $(document).ready(function () {
        $('.submit').on('click', function () {
            var startDate = $('.start-date').val();
            var endDate = $('.end-date').val();

            var start = new Date(startDate);
            var end = new Date(endDate);

            var diffDate = (end - start) / (1000 * 60 * 60 * 24);
            var days = Math.round(diffDate);
        });
    });

Critical t values in R

Extending @Ryogi answer above, you can take advantage of the lower.tail parameter like so:

qt(0.25/2, 40, lower.tail = FALSE) # 75% confidence

qt(0.01/2, 40, lower.tail = FALSE) # 99% confidence

How to add border around linear layout except at the bottom?

Save this xml and add as a background for the linear layout....

<shape xmlns:android="http://schemas.android.com/apk/res/android"> 
    <stroke android:width="4dp" android:color="#FF00FF00" /> 
    <solid android:color="#ffffff" /> 
    <padding android:left="7dp" android:top="7dp" 
            android:right="7dp" android:bottom="0dp" /> 
    <corners android:radius="4dp" /> 
</shape>

Hope this helps! :)

How do JavaScript closures work?

Closures are hard to explain because they are used to make some behaviour work that everybody intuitively expects to work anyway. I find the best way to explain them (and the way that I learned what they do) is to imagine the situation without them:

_x000D_
_x000D_
const makePlus = function(x) {
    return function(y) { return x + y; };
}

const plus5 = makePlus(5);
console.log(plus5(3));
_x000D_
_x000D_
_x000D_

What would happen here if JavaScript didn't know closures? Just replace the call in the last line by its method body (which is basically what function calls do) and you get:

console.log(x + 3);

Now, where's the definition of x? We didn't define it in the current scope. The only solution is to let plus5 carry its scope (or rather, its parent's scope) around. This way, x is well-defined and it is bound to the value 5.

What does %~d0 mean in a Windows batch file?

The magic variables %n contains the arguments used to invoke the file: %0 is the path to the bat-file itself, %1 is the first argument after, %2 is the second and so on.

Since the arguments are often file paths, there is some additional syntax to extract parts of the path. ~d is drive, ~p is the path (without drive), ~n is the file name. They can be combined so ~dp is drive+path.

%~dp0 is therefore pretty useful in a bat: it is the folder in which the executing bat file resides.

You can also get other kinds of meta info about the file: ~t is the timestamp, ~z is the size.

Look here for a reference for all command line commands. The tilde-magic codes are described under for.

Could not load file or assembly 'System.Data.SQLite'

This is an old post, but it may help some people searching on this error to try setting "Enable 32-Bit Applications" to True for the app pool. That is what resolved the error for me. I came upon this solution by reading some the comments to @beckelmw's answer.

How to keep footer at bottom of screen

use this style

min-height:250px;
height:auto;

How to pass parameters to a Script tag?

If you are using jquery you might want to consider their data method.

I have used something similar to what you are trying in your response but like this:

<script src="http://path.to/widget.js" param_a = "2" param_b = "5" param_c = "4">
</script>

You could also create a function that lets you grab the GET params directly (this is what I frequently use):

function $_GET(q,s) {
    s = s || window.location.search;
    var re = new RegExp('&'+q+'=([^&]*)','i');
    return (s=s.replace(/^\?/,'&').match(re)) ? s=s[1] : s='';
}

// Grab the GET param
var param_a = $_GET('param_a');

What's the fastest way to loop through an array in JavaScript?

It's just 2018 so an update could be nice...

And I really have to disagree with the accepted answer. It defers on different browsers. some do forEach faster, some for-loop, and some while here is a benchmark on all method http://jsben.ch/mW36e

arr.forEach( a => {
  // ...
}

and since you can see alot of for-loop like for(a = 0; ... ) then worth to mention that without 'var' variables will be define globally and this can dramatically affects on speed so it'll get slow.

Duff's device run faster on opera but not in firefox

_x000D_
_x000D_
var arr = arr = new Array(11111111).fill(255);_x000D_
var benches =     _x000D_
[ [ "empty", () => {_x000D_
  for(var a = 0, l = arr.length; a < l; a++);_x000D_
}]_x000D_
, ["for-loop", () => {_x000D_
  for(var a = 0, l = arr.length; a < l; ++a)_x000D_
    var b = arr[a] + 1;_x000D_
}]_x000D_
, ["for-loop++", () => {_x000D_
  for(var a = 0, l = arr.length; a < l; a++)_x000D_
    var b = arr[a] + 1;_x000D_
}]_x000D_
, ["for-loop - arr.length", () => {_x000D_
  for(var a = 0; a < arr.length; ++a )_x000D_
    var b = arr[a] + 1;_x000D_
}]_x000D_
, ["reverse for-loop", () => {_x000D_
  for(var a = arr.length - 1; a >= 0; --a )_x000D_
    var b = arr[a] + 1;_x000D_
}]_x000D_
,["while-loop", () => {_x000D_
  var a = 0, l = arr.length;_x000D_
  while( a < l ) {_x000D_
    var b = arr[a] + 1;_x000D_
    ++a;_x000D_
  }_x000D_
}]_x000D_
, ["reverse-do-while-loop", () => {_x000D_
  var a = arr.length - 1; // CAREFUL_x000D_
  do {_x000D_
    var b = arr[a] + 1;_x000D_
  } while(a--);   _x000D_
}]_x000D_
, ["forEach", () => {_x000D_
  arr.forEach( a => {_x000D_
    var b = a + 1;_x000D_
  });_x000D_
}]_x000D_
, ["for const..in (only 3.3%)", () => {_x000D_
  var ar = arr.slice(0,arr.length/33);_x000D_
  for( const a in ar ) {_x000D_
    var b = a + 1;_x000D_
  }_x000D_
}]_x000D_
, ["for let..in (only 3.3%)", () => {_x000D_
  var ar = arr.slice(0,arr.length/33);_x000D_
  for( let a in ar ) {_x000D_
    var b = a + 1;_x000D_
  }_x000D_
}]_x000D_
, ["for var..in (only 3.3%)", () => {_x000D_
  var ar = arr.slice(0,arr.length/33);_x000D_
  for( var a in ar ) {_x000D_
    var b = a + 1;_x000D_
  }_x000D_
}]_x000D_
, ["Duff's device", () => {_x000D_
  var len = arr.length;_x000D_
  var i, n = len % 8 - 1;_x000D_
_x000D_
  if (n > 0) {_x000D_
    do {_x000D_
      var b = arr[len-n] + 1;_x000D_
    } while (--n); // n must be greater than 0 here_x000D_
  }_x000D_
  n = (len * 0.125) ^ 0;_x000D_
  if (n > 0) { _x000D_
    do {_x000D_
      i = --n <<3;_x000D_
      var b = arr[i] + 1;_x000D_
      var c = arr[i+1] + 1;_x000D_
      var d = arr[i+2] + 1;_x000D_
      var e = arr[i+3] + 1;_x000D_
      var f = arr[i+4] + 1;_x000D_
      var g = arr[i+5] + 1;_x000D_
      var h = arr[i+6] + 1;_x000D_
      var k = arr[i+7] + 1;_x000D_
    }_x000D_
    while (n); // n must be greater than 0 here also_x000D_
  }_x000D_
}]];_x000D_
function bench(title, f) {_x000D_
  var t0 = performance.now();_x000D_
  var res = f();_x000D_
  return performance.now() - t0; // console.log(`${title} took ${t1-t0} msec`);_x000D_
}_x000D_
var globalVarTime = bench( "for-loop without 'var'", () => {_x000D_
  // Here if you forget to put 'var' so variables'll be global_x000D_
  for(a = 0, l = arr.length; a < l; ++a)_x000D_
     var b = arr[a] + 1;_x000D_
});_x000D_
var times = benches.map( function(a) {_x000D_
                      arr = new Array(11111111).fill(255);_x000D_
                      return [a[0], bench(...a)]_x000D_
                     }).sort( (a,b) => a[1]-b[1] );_x000D_
var max = times[times.length-1][1];_x000D_
times = times.map( a => {a[2] = (a[1]/max)*100; return a; } );_x000D_
var template = (title, time, n) =>_x000D_
  `<div>` +_x000D_
    `<span>${title} &nbsp;</span>` +_x000D_
    `<span style="width:${3+n/2}%">&nbsp;${Number(time.toFixed(3))}msec</span>` +_x000D_
  `</div>`;_x000D_
_x000D_
var strRes = times.map( t => template(...t) ).join("\n") + _x000D_
            `<br><br>for-loop without 'var' ${globalVarTime} msec.`;_x000D_
var $container = document.getElementById("container");_x000D_
$container.innerHTML = strRes;
_x000D_
body { color:#fff; background:#333; font-family:helvetica; }_x000D_
body > div > div {  clear:both   }_x000D_
body > div > div > span {_x000D_
  float:left;_x000D_
  width:43%;_x000D_
  margin:3px 0;_x000D_
  text-align:right;_x000D_
}_x000D_
body > div > div > span:nth-child(2) {_x000D_
  text-align:left;_x000D_
  background:darkorange;_x000D_
  animation:showup .37s .111s;_x000D_
  -webkit-animation:showup .37s .111s;_x000D_
}_x000D_
@keyframes showup { from { width:0; } }_x000D_
@-webkit-keyframes showup { from { width:0; } }
_x000D_
<div id="container"> </div>
_x000D_
_x000D_
_x000D_

Running Command Line in Java

what about

public class CmdExec {

public static Scanner s = null;


public static void main(String[] args) throws InterruptedException, IOException {
    s = new Scanner(System.in);
    System.out.print("$ ");
    String cmd = s.nextLine();
    final Process p = Runtime.getRuntime().exec(cmd);

    new Thread(new Runnable() {
        public void run() {
            BufferedReader input = new BufferedReader(new InputStreamReader(p.getInputStream()));
            String line = null; 

            try {
                while ((line = input.readLine()) != null) {
                    System.out.println(line);
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }).start();

    p.waitFor();
     }

 }

How to implement the Java comparable interface?

Implement Comparable<Animal> interface in your class and provide implementation of int compareTo(Animal other) method in your class.See This Post

C# Public Enums in Classes

Currently, your enum is nested inside of your Card class. All you have to do is move the definition of the enum out of the class:

// A better name which follows conventions instead of card_suits is
public enum CardSuit
{
    Clubs,
    Hearts,
    Spades,
    Diamonds
}

public class Card
{
}

To Specify:

The name change from card_suits to CardSuit was suggested because Microsoft guidelines suggest Pascal Case for Enumerations and the singular form is more descriptive in this case (as a plural would suggest that you're storing multiple enumeration values by ORing them together).