Programs & Examples On #Boost iterators

Writing standard-conforming iterators is tricky, but the need comes up often. In order to ease the implementation of new iterators, the Boost.Iterator library provides the iterator_facade class template, which implements many useful defaults and compile-time checks designed to help the iterator author ensure that his iterator is correct.

How to write log base(2) in c/c++

Improved version of what Ustaman Sangat did

static inline uint64_t
log2(uint64_t n)
{
    uint64_t val;
    for (val = 0; n > 1; val++, n >>= 1);

    return val;
}

sudo in php exec()

It sounds like you need to set up passwordless sudo. Try:

%admin ALL=(ALL) NOPASSWD: osascript myscript.scpt

Also comment out the following line (in /etc/sudoers via visudo), if it is there:

Defaults    requiretty

Apache won't start in wamp

Use apaches startup debug tool from command:

httpd.exe -e warn

  1. press Win+R
  2. type cmd and press enter
  3. goto directory which contains your apache httpd.exe file. for example if your wamp is installed in e:\wamp type cd /d e:\wamp\bin\apache\ApacheX.X.X\bin in cmd and press enter.
  4. type httpd.exe -e warn (or httpd.exe -e debug for more details) to see error message about problem which is prohibiting apache to start.

JSON Structure for List of Objects

As others mentioned, Justin's answer was close, but not quite right. I tested this using Visual Studio's "Paste JSON as C# Classes"

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

What is the difference between '/' and '//' when used for division?

/ --> Floating point division

// --> Floor division

Lets see some examples in both python 2.7 and in Python 3.5.

Python 2.7.10 vs. Python 3.5

print (2/3)  ----> 0                   Python 2.7
print (2/3)  ----> 0.6666666666666666  Python 3.5

Python 2.7.10 vs. Python 3.5

  print (4/2)  ----> 2         Python 2.7
  print (4/2)  ----> 2.0       Python 3.5

Now if you want to have (in python 2.7) same output as in python 3.5, you can do the following:

Python 2.7.10

from __future__ import division
print (2/3)  ----> 0.6666666666666666   #Python 2.7
print (4/2)  ----> 2.0                  #Python 2.7

Where as there is no differece between Floor division in both python 2.7 and in Python 3.5

138.93//3 ---> 46.0        #Python 2.7
138.93//3 ---> 46.0        #Python 3.5
4//3      ---> 1           #Python 2.7
4//3      ---> 1           #Python 3.5

Grouping switch statement cases together?

You can use like this:

case 4: case 2:
 {
   //code ...
 }

For use 4 or 2 switch case.

XDocument or XmlDocument

Also, note that XDocument is supported in Xbox 360 and Windows Phone OS 7.0. If you target them, develop for XDocument or migrate from XmlDocument.

Android Log.v(), Log.d(), Log.i(), Log.w(), Log.e() - When to use each one?

The different methods are indications of priority. As you've listed them, they're going from least to most important. I think how you specifically map them to debug logs in your code depends on the component or app you're working on, as well as how Android treats them on different build flavors (eng, userdebug, and user). I have done a fair amount of work in the native daemons in Android, and this is how I do it. It may not apply directly to your app, but there may be some common ground. If my explanation sounds vague, it's because some of this is more of an art than a science. My basic rule is to be as efficient as possible, ensure you can reasonably debug your component without killing the performance of the system, and always check for errors and log them.

V - Printouts of state at different intervals, or upon any events occurring which my component processes. Also possibly very detailed printouts of the payloads of messages/events that my component receives or sends.

D - Details of minor events that occur within my component, as well as payloads of messages/events that my component receives or sends.

I - The header of any messages/events that my component receives or sends, as well as any important pieces of the payload which are critical to my component's operation.

W - Anything that happens that is unusual or suspicious, but not necessarily an error.

E - Errors, meaning things that aren't supposed to happen when things are working as they should.

The biggest mistake I see people make is that they overuse things like V, D, and I, but never use W or E. If an error is, by definition, not supposed to happen, or should only happen very rarely, then it's extremely cheap for you to log a message when it occurs. On the other hand, if every time somebody presses a key you do a Log.i(), you're abusing the shared logging resource. Of course, use common sense and be careful with error logs for things outside of your control (like network errors), or those contained in tight loops.

Maybe Bad

Log.i("I am here");

Good

Log.e("I shouldn't be here");

With all this in mind, the closer your code gets to "production ready", the more you can restrict the base logging level for your code (you need V in alpha, D in beta, I in production, or possibly even W in production). You should run through some simple use cases and view the logs to ensure that you can still mostly understand what's happening as you apply more restrictive filtering. If you run with the filter below, you should still be able to tell what your app is doing, but maybe not get all the details.

logcat -v threadtime MyApp:I *:S

How can I pass POST parameters in a URL?

This could work if the PHP script generates a form for each entry with hidden fields and the href uses JavaScript to post the form.

Make WPF Application Fullscreen (Cover startmenu)

window.WindowStyle = WindowStyle.None;
window.ResizeMode = ResizeMode.NoResize;
window.Left = 0;
window.Top = 0;
window.Width = SystemParameters.VirtualScreenWidth;
window.Height = SystemParameters.VirtualScreenHeight;
window.Topmost = true;

Works with multiple screens

Good MapReduce examples

One set of familiar operations that you can do in MapReduce is the set of normal SQL operations: SELECT, SELECT WHERE, GROUP BY, ect.

Another good example is matrix multiply, where you pass one row of M and the entire vector x and compute one element of M * x.

mySQL :: insert into table, data from another table?

This query is for add data from one table to another table using foreign key

let qry = "INSERT INTO `tb_customer_master` (`My_Referral_Code`, `City_Id`, `Cust_Name`, `Reg_Date_Time`, `Mobile_Number`, `Email_Id`, `Gender`, `Cust_Age`, `Profile_Image`, `Token`, `App_Type`, `Refer_By_Referral_Code`, `Status`) values ('" + randomstring.generate(7) + "', '" + req.body.City_Id + "', '" + req.body.Cust_Name + "', '" + req.body.Reg_Date_Time + "','" + req.body.Mobile_Number + "','" + req.body.Email_Id + "','" + req.body.Gender + "','" + req.body.Cust_Age + "','" + req.body.Profile_Image + "','" + req.body.Token + "','" + req.body.App_Type + "','" + req.body.Refer_By_Referral_Code + "','" + req.body.Status + "')";
                        connection.query(qry, (err, rows) => {
                            if (err) { res.send(err) } else {
                                let insert = "INSERT INTO `tb_customer_and_transaction_master` (`Cust_Id`)values ('" + rows.insertId + "')";
                                connection.query(insert, (err) => {
                                    if (err) {
                                        res.json(err)
                                    } else {
                                        res.json("Customer added")
                                    }
                                })
                            }
    
    
                        })
                    }
                }
    
            }
        })
    })

Compare two files and write it to "match" and "nomatch" files

In Eztrieve it's really easy, below is an example how you could code it:

//STEP01   EXEC PGM=EZTPA00                                        
//FILEA    DD DSN=FILEA,DISP=SHR   
//FILEB    DD DSN=FILEB,DISP=SHR
//FILEC    DD DSN=FILEC.DIF,    
//            DISP=(NEW,CATLG,DELETE),                             
//            SPACE=(CYL,(100,50),RLSE),                           
//            UNIT=PRMDA,                                          
//            DCB=(RECFM=FB,LRECL=5200,BLKSIZE=0)                  
//SYSOUT   DD SYSOUT=*                                             
//SRTMSG   DD SYSOUT=*                                             
//SYSPRINT DD SYSOUT=*                                             
//SYSIN    DD *                                                    
 FILE FILEA                                                        
   FA-KEY       1   7 A                                         
   FA-REC1      8  10 A
   FA-REC2     18   5 A

 FILE FILEB                                                        
   FB-KEY       1   7 A                                         
   FB-REC1      8  10 A                                         
   FB-REC2     18   5 A                                         

 FILE FILEC                                                        

 FILE FILED                                                        
   FD-KEY       1   7 A                                         
   FD-REC1      8  10 A                                         
   FD-REC2     18   5 A                                         


 JOB INPUT (FILEA KEY FA-KEY FILEB KEY FB-KEY)                     
   IF MATCHED            
      FD-KEY   =  FB-KEY                                      
      FD-REC1  =  FA-REC1
      FD-REC2  =  FB-REC2
      PUT FILED
   ELSE
      IF FILEA
         PUT FILEC FROM FILEA                                         
      ELSE
         PUT FILEC FROM FILEB
      END-IF                                         
   END-IF                                                          
/*                       

How can you get the active users connected to a postgreSQL database via SQL?

(question) Don't you get that info in

select * from pg_user;

or using the view pg_stat_activity:

select * from pg_stat_activity;

Added:

the view says:

One row per server process, showing database OID, database name, process ID, user OID, user name, current query, query's waiting status, time at which the current query began execution, time at which the process was started, and client's address and port number. The columns that report data on the current query are available unless the parameter stats_command_string has been turned off. Furthermore, these columns are only visible if the user examining the view is a superuser or the same as the user owning the process being reported on.

can't you filter and get that information? that will be the current users on the Database, you can use began execution time to get all queries from last 5 minutes for example...

something like that.

How to make grep only match if the entire line matches?

similarly with awk

 awk '/^ABB\.log$/' file

How to Select Top 100 rows in Oracle?

First 10 customers inserted into db (table customers):

select * from customers where customer_id <=
(select  min(customer_id)+10 from customers)

Last 10 customers inserted into db (table customers):

select * from customers where customer_id >=
(select  max(customer_id)-10 from customers)

Hope this helps....

When to use "new" and when not to, in C++?

New is always used to allocate dynamic memory, which then has to be freed.

By doing the first option, that memory will be automagically freed when scope is lost.

Point p1 = Point(0,0); //This is if you want to be safe and don't want to keep the memory outside this function.

Point* p2 = new Point(0, 0); //This must be freed manually. with...
delete p2;

How to fix: "UnicodeDecodeError: 'ascii' codec can't decode byte"

tl;dr / quick fix

  • Don't decode/encode willy nilly
  • Don't assume your strings are UTF-8 encoded
  • Try to convert strings to Unicode strings as soon as possible in your code
  • Fix your locale: How to solve UnicodeDecodeError in Python 3.6?
  • Don't be tempted to use quick reload hacks

Unicode Zen in Python 2.x - The Long Version

Without seeing the source it's difficult to know the root cause, so I'll have to speak generally.

UnicodeDecodeError: 'ascii' codec can't decode byte generally happens when you try to convert a Python 2.x str that contains non-ASCII to a Unicode string without specifying the encoding of the original string.

In brief, Unicode strings are an entirely separate type of Python string that does not contain any encoding. They only hold Unicode point codes and therefore can hold any Unicode point from across the entire spectrum. Strings contain encoded text, beit UTF-8, UTF-16, ISO-8895-1, GBK, Big5 etc. Strings are decoded to Unicode and Unicodes are encoded to strings. Files and text data are always transferred in encoded strings.

The Markdown module authors probably use unicode() (where the exception is thrown) as a quality gate to the rest of the code - it will convert ASCII or re-wrap existing Unicodes strings to a new Unicode string. The Markdown authors can't know the encoding of the incoming string so will rely on you to decode strings to Unicode strings before passing to Markdown.

Unicode strings can be declared in your code using the u prefix to strings. E.g.

>>> my_u = u'my ünicôdé string'
>>> type(my_u)
<type 'unicode'>

Unicode strings may also come from file, databases and network modules. When this happens, you don't need to worry about the encoding.

Gotchas

Conversion from str to Unicode can happen even when you don't explicitly call unicode().

The following scenarios cause UnicodeDecodeError exceptions:

# Explicit conversion without encoding
unicode('€')

# New style format string into Unicode string
# Python will try to convert value string to Unicode first
u"The currency is: {}".format('€')

# Old style format string into Unicode string
# Python will try to convert value string to Unicode first
u'The currency is: %s' % '€'

# Append string to Unicode
# Python will try to convert string to Unicode first
u'The currency is: ' + '€'         

Examples

In the following diagram, you can see how the word café has been encoded in either "UTF-8" or "Cp1252" encoding depending on the terminal type. In both examples, caf is just regular ascii. In UTF-8, é is encoded using two bytes. In "Cp1252", é is 0xE9 (which is also happens to be the Unicode point value (it's no coincidence)). The correct decode() is invoked and conversion to a Python Unicode is successfull: Diagram of a string being converted to a Python Unicode string

In this diagram, decode() is called with ascii (which is the same as calling unicode() without an encoding given). As ASCII can't contain bytes greater than 0x7F, this will throw a UnicodeDecodeError exception:

Diagram of a string being converted to a Python Unicode string with the wrong encoding

The Unicode Sandwich

It's good practice to form a Unicode sandwich in your code, where you decode all incoming data to Unicode strings, work with Unicodes, then encode to strs on the way out. This saves you from worrying about the encoding of strings in the middle of your code.

Input / Decode

Source code

If you need to bake non-ASCII into your source code, just create Unicode strings by prefixing the string with a u. E.g.

u'Zürich'

To allow Python to decode your source code, you will need to add an encoding header to match the actual encoding of your file. For example, if your file was encoded as 'UTF-8', you would use:

# encoding: utf-8

This is only necessary when you have non-ASCII in your source code.

Files

Usually non-ASCII data is received from a file. The io module provides a TextWrapper that decodes your file on the fly, using a given encoding. You must use the correct encoding for the file - it can't be easily guessed. For example, for a UTF-8 file:

import io
with io.open("my_utf8_file.txt", "r", encoding="utf-8") as my_file:
     my_unicode_string = my_file.read() 

my_unicode_string would then be suitable for passing to Markdown. If a UnicodeDecodeError from the read() line, then you've probably used the wrong encoding value.

CSV Files

The Python 2.7 CSV module does not support non-ASCII characters . Help is at hand, however, with https://pypi.python.org/pypi/backports.csv.

Use it like above but pass the opened file to it:

from backports import csv
import io
with io.open("my_utf8_file.txt", "r", encoding="utf-8") as my_file:
    for row in csv.reader(my_file):
        yield row

Databases

Most Python database drivers can return data in Unicode, but usually require a little configuration. Always use Unicode strings for SQL queries.

MySQL

In the connection string add:

charset='utf8',
use_unicode=True

E.g.

>>> db = MySQLdb.connect(host="localhost", user='root', passwd='passwd', db='sandbox', use_unicode=True, charset="utf8")
PostgreSQL

Add:

psycopg2.extensions.register_type(psycopg2.extensions.UNICODE)
psycopg2.extensions.register_type(psycopg2.extensions.UNICODEARRAY)

HTTP

Web pages can be encoded in just about any encoding. The Content-type header should contain a charset field to hint at the encoding. The content can then be decoded manually against this value. Alternatively, Python-Requests returns Unicodes in response.text.

Manually

If you must decode strings manually, you can simply do my_string.decode(encoding), where encoding is the appropriate encoding. Python 2.x supported codecs are given here: Standard Encodings. Again, if you get UnicodeDecodeError then you've probably got the wrong encoding.

The meat of the sandwich

Work with Unicodes as you would normal strs.

Output

stdout / printing

print writes through the stdout stream. Python tries to configure an encoder on stdout so that Unicodes are encoded to the console's encoding. For example, if a Linux shell's locale is en_GB.UTF-8, the output will be encoded to UTF-8. On Windows, you will be limited to an 8bit code page.

An incorrectly configured console, such as corrupt locale, can lead to unexpected print errors. PYTHONIOENCODING environment variable can force the encoding for stdout.

Files

Just like input, io.open can be used to transparently convert Unicodes to encoded byte strings.

Database

The same configuration for reading will allow Unicodes to be written directly.

Python 3

Python 3 is no more Unicode capable than Python 2.x is, however it is slightly less confused on the topic. E.g the regular str is now a Unicode string and the old str is now bytes.

The default encoding is UTF-8, so if you .decode() a byte string without giving an encoding, Python 3 uses UTF-8 encoding. This probably fixes 50% of people's Unicode problems.

Further, open() operates in text mode by default, so returns decoded str (Unicode ones). The encoding is derived from your locale, which tends to be UTF-8 on Un*x systems or an 8-bit code page, such as windows-1251, on Windows boxes.

Why you shouldn't use sys.setdefaultencoding('utf8')

It's a nasty hack (there's a reason you have to use reload) that will only mask problems and hinder your migration to Python 3.x. Understand the problem, fix the root cause and enjoy Unicode zen. See Why should we NOT use sys.setdefaultencoding("utf-8") in a py script? for further details

Qt jpg image display

If the only thing you want to do is drop in an image onto a widget withouth the complexity of the graphics API, you can also just create a new QWidget and set the background with StyleSheets. Something like this:

MainWindow::MainWindow(QWidget *parent) : QMainWindow(parent)
{
    ...
    QWidget *pic = new QWidget(this);
    pic->setStyleSheet("background-image: url(test.png)");
    pic->setGeometry(QRect(50,50,128,128));
    ...
}

What is App.config in C#.NET? How to use it?

App.Config is an XML file that is used as a configuration file for your application. In other words, you store inside it any setting that you may want to change without having to change code (and recompiling). It is often used to store connection strings.

See this MSDN article on how to do that.

How to fix 'android.os.NetworkOnMainThreadException'?

RxAndroid is another better alternative to this problem and it saves us from hassles of creating threads and then posting results on Android UI thread. We just need to specify threads on which tasks need to be executed and everything is handled internally.

Observable<List<String>> musicShowsObservable = Observable.fromCallable(new Callable<List<String>>() { 

  @Override 
  public List<String> call() { 
    return mRestClient.getFavoriteMusicShows(); 
  }
});

mMusicShowSubscription = musicShowsObservable
.subscribeOn(Schedulers.io())
.observeOn(AndroidSchedulers.mainThread())
.subscribe(new Observer<List<String>>() {

    @Override 
    public void onCompleted() { }

    @Override 
    public void onError(Throwable e) { }

    @Override 
    public void onNext(List<String> musicShows){
        listMusicShows(musicShows);
    }
});
  1. By specifiying (Schedulers.io()),RxAndroid will run getFavoriteMusicShows() on a different thread.

  2. By using AndroidSchedulers.mainThread() we want to observe this Observable on the UI thread, i.e. we want our onNext() callback to be called on the UI thread

how to use Spring Boot profiles

The @Profile annotation allows you to indicate that a component is eligible for registration when one or more specified profiles are active. Using our example above, we can rewrite the dataSource configuration as follows:

@Configuration
@Profile("dev")
public class StandaloneDataConfig {

    @Bean
    public DataSource dataSource() {
        return new EmbeddedDatabaseBuilder()
            .setType(EmbeddedDatabaseType.HSQL)
            .addScript("classpath:com/bank/config/sql/schema.sql")
            .addScript("classpath:com/bank/config/sql/test-data.sql")
            .build();
    }
}

And other one:

@Configuration
@Profile("production")
public class JndiDataConfig {

    @Bean(destroyMethod="")
    public DataSource dataSource() throws Exception {
        Context ctx = new InitialContext();
        return (DataSource) ctx.lookup("java:comp/env/jdbc/datasource");
    }
}

How can you print multiple variables inside a string using printf?

Change the line where you print the output to:

printf("\nmaximum of %d and %d is = %d",a,b,c);

See the docs here

Passing an array as parameter in JavaScript

JavaScript is a dynamically typed language. This means that you never need to declare the type of a function argument (or any other variable). So, your code will work as long as arrayP is an array and contains elements with a value property.

CFNetwork SSLHandshake failed iOS 9

The device I tested at had wrong time set. So when I tried accessing a page with a certificate that would run out soon it would deny access because the device though the certificate had expired. To fix, set proper time on the device!

Why does 'git commit' not save my changes?

You didn't add the changes. Either specifically add them via

git add filename1 filename2

or add all changes (from root path of the project)

git add .

or use the shorthand -a while commiting:

git commit -a -m "message".

Docker-Compose with multiple services

The thing is that you are using the option -t when running your container.

Could you check if enabling the tty option (see reference) in your docker-compose.yml file the container keeps running?

version: '2'
services:
  ubuntu:
        build: .
        container_name: ubuntu
        volumes:
            - ~/sph/laravel52:/www/laravel
        ports:
          - "80:80"
        tty: true

Android: how to parse URL String with spaces to URI object?

I wrote this function:

public static String encode(@NonNull String uriString) {
    if (TextUtils.isEmpty(uriString)) {
        Assert.fail("Uri string cannot be empty!");
        return uriString;
    }
    // getQueryParameterNames is not exist then cannot iterate on queries
    if (Build.VERSION.SDK_INT < 11) {
        return uriString;
    }

    // Check if uri has valid characters
    // See https://tools.ietf.org/html/rfc3986
    Pattern allowedUrlCharacters = Pattern.compile("([A-Za-z0-9_.~:/?\\#\\[\\]@!$&'()*+,;" +
            "=-]|%[0-9a-fA-F]{2})+");
    Matcher matcher = allowedUrlCharacters.matcher(uriString);
    String validUri = null;
    if (matcher.find()) {
        validUri = matcher.group();
    }
    if (TextUtils.isEmpty(validUri) || uriString.length() == validUri.length()) {
        return uriString;
    }

    // The uriString is not encoded. Then recreate the uri and encode it this time
    Uri uri = Uri.parse(uriString);
    Uri.Builder uriBuilder = new Uri.Builder()
            .scheme(uri.getScheme())
            .authority(uri.getAuthority());
    for (String path : uri.getPathSegments()) {
        uriBuilder.appendPath(path);
    }
    for (String key : uri.getQueryParameterNames()) {
        uriBuilder.appendQueryParameter(key, uri.getQueryParameter(key));
    }
    String correctUrl = uriBuilder.build().toString();
    return correctUrl;
}

ExecuteReader requires an open and available Connection. The connection's current state is Connecting

Sorry for only commenting in the first place, but i'm posting almost every day a similar comment since many people think that it would be smart to encapsulate ADO.NET functionality into a DB-Class(me too 10 years ago). Mostly they decide to use static/shared objects since it seems to be faster than to create a new object for any action.

That is neither a good idea in terms of peformance nor in terms of fail-safety.

Don't poach on the Connection-Pool's territory

There's a good reason why ADO.NET internally manages the underlying Connections to the DBMS in the ADO-NET Connection-Pool:

In practice, most applications use only one or a few different configurations for connections. This means that during application execution, many identical connections will be repeatedly opened and closed. To minimize the cost of opening connections, ADO.NET uses an optimization technique called connection pooling.

Connection pooling reduces the number of times that new connections must be opened. The pooler maintains ownership of the physical connection. It manages connections by keeping alive a set of active connections for each given connection configuration. Whenever a user calls Open on a connection, the pooler looks for an available connection in the pool. If a pooled connection is available, it returns it to the caller instead of opening a new connection. When the application calls Close on the connection, the pooler returns it to the pooled set of active connections instead of closing it. Once the connection is returned to the pool, it is ready to be reused on the next Open call.

So obviously there's no reason to avoid creating,opening or closing connections since actually they aren't created,opened and closed at all. This is "only" a flag for the connection pool to know when a connection can be reused or not. But it's a very important flag, because if a connection is "in use"(the connection pool assumes), a new physical connection must be openend to the DBMS what is very expensive.

So you're gaining no performance improvement but the opposite. If the maximum pool size specified (100 is the default) is reached, you would even get exceptions(too many open connections ...). So this will not only impact the performance tremendously but also be a source for nasty errors and (without using Transactions) a data-dumping-area.

If you're even using static connections you're creating a lock for every thread trying to access this object. ASP.NET is a multithreading environment by nature. So theres a great chance for these locks which causes performance issues at best. Actually sooner or later you'll get many different exceptions(like your ExecuteReader requires an open and available Connection).

Conclusion:

  • Don't reuse connections or any ADO.NET objects at all.
  • Don't make them static/shared(in VB.NET)
  • Always create, open(in case of Connections), use, close and dispose them where you need them(f.e. in a method)
  • use the using-statement to dispose and close(in case of Connections) implicitely

That's true not only for Connections(although most noticable). Every object implementing IDisposable should be disposed(simplest by using-statement), all the more in the System.Data.SqlClient namespace.

All the above speaks against a custom DB-Class which encapsulates and reuse all objects. That's the reason why i commented to trash it. That's only a problem source.


Edit: Here's a possible implementation of your retrievePromotion-method:

public Promotion retrievePromotion(int promotionID)
{
    Promotion promo = null;
    var connectionString = System.Configuration.ConfigurationManager.ConnectionStrings["MainConnStr"].ConnectionString;
    using (SqlConnection connection = new SqlConnection(connectionString))
    {
        var queryString = "SELECT PromotionID, PromotionTitle, PromotionURL FROM Promotion WHERE PromotionID=@PromotionID";
        using (var da = new SqlDataAdapter(queryString, connection))
        {
            // you could also use a SqlDataReader instead
            // note that a DataTable does not need to be disposed since it does not implement IDisposable
            var tblPromotion = new DataTable();
            // avoid SQL-Injection
            da.SelectCommand.Parameters.Add("@PromotionID", SqlDbType.Int);
            da.SelectCommand.Parameters["@PromotionID"].Value = promotionID;
            try
            {
                connection.Open(); // not necessarily needed in this case because DataAdapter.Fill does it otherwise 
                da.Fill(tblPromotion);
                if (tblPromotion.Rows.Count != 0)
                {
                    var promoRow = tblPromotion.Rows[0];
                    promo = new Promotion()
                    {
                        promotionID    = promotionID,
                        promotionTitle = promoRow.Field<String>("PromotionTitle"),
                        promotionUrl   = promoRow.Field<String>("PromotionURL")
                    };
                }
            }
            catch (Exception ex)
            {
                // log this exception or throw it up the StackTrace
                // we do not need a finally-block to close the connection since it will be closed implicitely in an using-statement
                throw;
            }
        }
    }
    return promo;
}

Get JSONArray without array name?

JSONArray has a constructor which takes a String source (presumed to be an array).

So something like this

JSONArray array = new JSONArray(yourJSONArrayAsString);

Is Python interpreted, or compiled, or both?

Its a big confusion for the people who started working on python and the answers here are a little difficult to comprehend so i'll make it easier.

When we instruct Python to run our script, there are a few steps that Python carries out before our code actually starts crunching away:

  • It is compiled to bytecode.
  • Then it is routed to virtual machine.

When we execute a source code, Python compiles it into a byte code. Compilation is a translation step, and the byte code is a low-level platform-independent representation of source code. Note that the Python byte code is not binary machine code (e.g., instructions for an Intel chip).

Actually, Python translate each statement of the source code into byte code instructions by decomposing them into individual steps. The byte code translation is performed to speed execution. Byte code can be run much more quickly than the original source code statements. It has.pyc extension and it will be written if it can write to our machine.

So, next time we run the same program, Python will load the .pyc file and skip the compilation step unless it's been changed. Python automatically checks the timestamps of source and byte code files to know when it must recompile. If we resave the source code, byte code is automatically created again the next time the program is run.

If Python cannot write the byte code files to our machine, our program still works. The byte code is generated in memory and simply discarded on program exit. But because .pyc files speed startup time, we may want to make sure it has been written for larger programs.

Let's summarize what happens behind the scenes. When a Python executes a program, Python reads the .py into memory, and parses it in order to get a bytecode, then goes on to execute. For each module that is imported by the program, Python first checks to see whether there is a precompiled bytecode version, in a .pyo or .pyc, that has a timestamp which corresponds to its .py file. Python uses the bytecode version if any. Otherwise, it parses the module's .py file, saves it into a .pyc file, and uses the bytecode it just created.

Byte code files are also one way of shipping Python codes. Python will still run a program if all it can find are.pyc files, even if the original .py source files are not there.

Python Virtual Machine (PVM)

Once our program has been compiled into byte code, it is shipped off for execution to Python Virtual Machine (PVM). The PVM is not a separate program. It need not be installed by itself. Actually, the PVM is just a big loop that iterates through our byte code instruction, one by one, to carry out their operations. The PVM is the runtime engine of Python. It's always present as part of the Python system. It's the component that truly runs our scripts. Technically it's just the last step of what is called the Python interpreter.

Find out which remote branch a local branch is tracking

$ git remote --verbose 

(or)

$ git remote --v 

(or)

$ git remote -vv

(or) To Know about the remote branch in details and Head branch

$ git remote show origin

To Know about the specific, remote branch and Head branch

$ git remote show origin | grep master
Username for 'https://github.com': Pra.....@9
  HEAD branch: master
    master tracked
    master merges with remote master
    master pushes to master (up to date)

Deploy a project using Git push

Update: I'm now using Lloyd Moore solution with the key agent ssh -A .... Pushing to a main repo and then pulling from it in parallel from all your machines is a bit faster and requires less setup on those machines.


Not seeing this solution here. just push via ssh if git is installed on the server.

You'll need the following entry in your local .git/config

[remote "amazon"]
    url = amazon:/path/to/project.git
    fetch = +refs/heads/*:refs/remotes/amazon/*

But hey, whats that with amazon:? In your local ~/.ssh/config you'll need to add the following entry:

Host amazon
    Hostname <YOUR_IP>
    User <USER>
    IdentityFile ~/.ssh/amazon-private-key

now you can call

git push amazon master
ssh <USER>@<YOUR_IP> 'cd /path/to/project && git pull'

(BTW: /path/to/project.git is different to the actual working directory /path/to/project)

How to center canvas in html5

Give the canvas the following css style properties:

canvas {
    padding-left: 0;
    padding-right: 0;
    margin-left: auto;
    margin-right: auto;
    display: block;
    width: 800px;
}

Edit

Since this answer is quite popular, let me add a little bit more details.

The above properties will horizontally center the canvas, div or whatever other node you have relative to it's parent. There is no need to change the top or bottom margins and paddings. You specify a width and let the browser fill the remaining space with the auto margins.

However, if you want to type less, you could use whatever css shorthand properties you wish, such as

canvas {
    padding: 0;
    margin: auto;
    display: block;
    width: 800px;
}

Centering the canvas vertically requires a different approach however. You need to use absolute positioning, and specify both the width and the height. Then set the left, right, top and bottom properties to 0 and let the browser fill the remaining space with the auto margins.

canvas {
    padding: 0;
    margin: auto;
    display: block;
    width: 800px;
    height: 600px;
    position: absolute;
    top: 0;
    bottom: 0;
    left: 0;
    right: 0;
}

The canvas will center itself based on the first parent element that has position set to relative or absolute, or the body if none is found.

Another approach would be to use display: flex, that is available in IE11

Also, make sure you use a recent doctype such as xhtml or html 5.

MySQL's now() +1 day

Try doing: INSERT INTO table(data, date) VALUES ('$data', now() + interval 1 day)

Why am I getting this error: No mapping specified for the following EntitySet/AssociationSet - Entity1?

I ran into the same error, but I was not using model-first. It turned out that somehow my EDMX file contained a reference to a table even though it did not show up in the designer. Interestingly, when I did a text search for the table name in Visual Studio (2013) the table was not found.

To solve the issue, I used an external editor (Notepad++) to find the reference to the offending table in the EDMX file, and then (carefully) removed all references to the table. I am sorry to say that I do not know how the EDMX file got into this state in the first place.

how do I check in bash whether a file was created more than x time ago?

Using the stat to figure out the last modification date of the file, date to figure out the current time and a liberal use of bashisms, one can do the test that you want based on the file's last modification time1.

if [ "$(( $(date +"%s") - $(stat -c "%Y" $somefile) ))" -gt "7200" ]; then
   echo "$somefile is older then 2 hours"
fi

While the code is a bit less readable then the find approach, I think its a better approach then running find to look at a file you already "found". Also, date manipulation is fun ;-)


  1. As Phil correctly noted creation time is not recorded, but use %Z instead of %Y below to get "change time" which may be what you want.

[Update]

For mac users, use stat -f "%m" $somefile instead of the Linux specific syntax above

Meaning of Open hashing and Closed hashing

The name open addressing refers to the fact that the location ("address") of the element is not determined by its hash value. (This method is also called closed hashing).

In separate chaining, each bucket is independent, and has some sort of ADT (list, binary search trees, etc) of entries with the same index. In a good hash table, each bucket has zero or one entries, because we need operations of order O(1) for insert, search, etc.

This is a example of separate chaining using C++ with a simple hash function using mod operator (clearly, a bad hash function)

LD_LIBRARY_PATH vs LIBRARY_PATH

LD_LIBRARY_PATH is searched when the program starts, LIBRARY_PATH is searched at link time.

caveat from comments:

How to know if an object has an attribute in Python

This is super simple, just use dir(object)
This will return a list of every available function and attribute of the object.

Why can I ping a server but not connect via SSH?

ping (ICMP protocol) and ssh are two different protocols.

  1. It could be that ssh service is not running or not installed

  2. firewall restriction (local to server like iptables or even sshd config lock down ) or (external firewall that protects incomming traffic to network hosting 111.111.111.111)

First check is to see if ssh port is up

nc -v -w 1 111.111.111.111 -z 22

if it succeeds then ssh should communicate if not then it will never work until restriction is lifted or ssh is started

How to hide code from cells in ipython notebook visualized with nbviewer?

jupyter nbconvert yourNotebook.ipynb --no-input --no-prompt

jupyter nbconvert yourNotebook.ipynb This part of the code will take the latex file format of the jupyter notebook and converts it to a html

--no-input This is like a parameter we are saying during conversion that dont add any inputs : here the input to a cell is the code.. so we hide it

--no-prompt Here also we are saying, During conversion dont show any prompts form the code like errors or warnings in the final HTML file ) so that that html will have only the Text and the code output in the form of a report !!..

Hope it helps :)

What good are SQL Server schemas?

Schemas logically group tables, procedures, views together. All employee-related objects in the employee schema, etc.

You can also give permissions to just one schema, so that users can only see the schema they have access to and nothing else.

Construct pandas DataFrame from items in nested dictionary

A pandas MultiIndex consists of a list of tuples. So the most natural approach would be to reshape your input dict so that its keys are tuples corresponding to the multi-index values you require. Then you can just construct your dataframe using pd.DataFrame.from_dict, using the option orient='index':

user_dict = {12: {'Category 1': {'att_1': 1, 'att_2': 'whatever'},
                  'Category 2': {'att_1': 23, 'att_2': 'another'}},
             15: {'Category 1': {'att_1': 10, 'att_2': 'foo'},
                  'Category 2': {'att_1': 30, 'att_2': 'bar'}}}

pd.DataFrame.from_dict({(i,j): user_dict[i][j] 
                           for i in user_dict.keys() 
                           for j in user_dict[i].keys()},
                       orient='index')


               att_1     att_2
12 Category 1      1  whatever
   Category 2     23   another
15 Category 1     10       foo
   Category 2     30       bar

An alternative approach would be to build your dataframe up by concatenating the component dataframes:

user_ids = []
frames = []

for user_id, d in user_dict.iteritems():
    user_ids.append(user_id)
    frames.append(pd.DataFrame.from_dict(d, orient='index'))

pd.concat(frames, keys=user_ids)

               att_1     att_2
12 Category 1      1  whatever
   Category 2     23   another
15 Category 1     10       foo
   Category 2     30       bar

How to cancel/abort jQuery AJAX request?

When you make a request to a server, have it check to see if a progress is not null (or fetching that data) first. If it is fetching data, abort the previous request and initiate the new one.

var progress = null

function fn () {    
    if (progress) {
        progress.abort();
    }
    progress = $.ajax('ajax/progress.ftl', {
        success: function(data) {
            //do something
            progress = null;
        }
    });
}

Python class returning value

If what you want is a way to turn your class into kind of a list without subclassing list, then just make a method that returns a list:

def MyClass():
    def __init__(self):
        self.value1 = 1
        self.value2 = 2

    def get_list(self):
        return [self.value1, self.value2...]


>>>print MyClass().get_list()
[1, 2...]

If you meant that print MyClass() will print a list, just override __repr__:

class MyClass():        
    def __init__(self):
        self.value1 = 1
        self.value2 = 2

    def __repr__(self):
        return repr([self.value1, self.value2])

EDIT: I see you meant how to make objects compare. For that, you override the __cmp__ method.

class MyClass():
    def __cmp__(self, other):
        return cmp(self.get_list(), other.get_list())

SQL Server 2008- Get table constraints

Here's a script to get foreign keys:

    SELECT TOP(150)
       t.[name] AS [Table],
       cols.[name] AS [Column],
       t2.[name] AS [Referenced Table],
       c2.[name] AS [Referenced Column],
       constr.[name] AS [Constraint]
  FROM sys.tables t
 INNER JOIN sys.foreign_keys constr ON constr.parent_object_id = t.object_id
 INNER JOIN sys.tables t2 ON t2.object_id = constr.referenced_object_id
 INNER JOIN sys.foreign_key_columns fkc ON fkc.constraint_object_id = constr.object_id
 INNER JOIN sys.columns cols ON cols.object_id = fkc.parent_object_id AND cols.column_id = fkc.parent_column_id
 INNER JOIN sys.columns c2 ON c2.object_id = fkc.referenced_object_id AND c2.column_id = fkc.referenced_column_id
 --WHERE t.[name] IN ('?', '?', ...)
 ORDER BY t.[Name], cols.[name]

jQuery Call to WebService returns "No Transport" error

i solve it by using dataType='jsonp' at the place of dataType='json'

Is it safe to use Project Lombok?

When I showed the project to my team the enthusiasm was high, so I think you should not be afraid of team response.

  • As far as ROI, it is a snap to integrate, and requires no code change in its basic form. (just adding a single annotation to your class)

  • And last, if you change your mind, you can run the unlombok, or let your IDE create these setters, getters, and ctors, (which I think no one will ask for once they see how clear your pojo becomes)

Parameterize an SQL IN clause

You can pass the parameter as a string

So you have the string

DECLARE @tags

SET @tags = ‘ruby|rails|scruffy|rubyonrails’

select * from Tags 
where Name in (SELECT item from fnSplit(@tags, ‘|’))
order by Count desc

Then all you have to do is pass the string as 1 parameter.

Here is the split function I use.

CREATE FUNCTION [dbo].[fnSplit](
    @sInputList VARCHAR(8000) -- List of delimited items
  , @sDelimiter VARCHAR(8000) = ',' -- delimiter that separates items
) RETURNS @List TABLE (item VARCHAR(8000))

BEGIN
DECLARE @sItem VARCHAR(8000)
WHILE CHARINDEX(@sDelimiter,@sInputList,0) <> 0
 BEGIN
 SELECT
  @sItem=RTRIM(LTRIM(SUBSTRING(@sInputList,1,CHARINDEX(@sDelimiter,@sInputList,0)-1))),
  @sInputList=RTRIM(LTRIM(SUBSTRING(@sInputList,CHARINDEX(@sDelimiter,@sInputList,0)+LEN(@sDelimiter),LEN(@sInputList))))

 IF LEN(@sItem) > 0
  INSERT INTO @List SELECT @sItem
 END

IF LEN(@sInputList) > 0
 INSERT INTO @List SELECT @sInputList -- Put the last item in
RETURN
END

How do you share code between projects/solutions in Visual Studio?

Now you can use the Shared Project

Shared Project is a great way of sharing common code across multiple application We already have experienced with the Shared Project type in Visual Studio 2013 as part of Windows 8.1 Universal App Development, But with Visual Studio 2015, it is a Standalone New Project Template; and we can use it with other types of app like Console, Desktop, Phone, Store App etc.. This types of project is extremely helpful when we want to share a common code, logic as well as components across multiple applications with in single platform. This also allows accessing the platform-specific API ’s, assets etc.

enter image description here

for more info check this

How to import component into another root component in Angular 2

above answers In simple words, you have to register under @NgModule's

declarations: [
    AppComponent, YourNewComponentHere
  ] 

of app.module.ts

do not forget to import that component.

How to get a cross-origin resource sharing (CORS) post request working

Took me some time to find the solution.

In case your server response correctly and the request is the problem, you should add withCredentials: true to the xhrFields in the request:

$.ajax({
    url: url,
    type: method,
    // This is the important part
    xhrFields: {
        withCredentials: true
    },
    // This is the important part
    data: data,
    success: function (response) {
        // handle the response
    },
    error: function (xhr, status) {
        // handle errors
    }
});

Note: jQuery >= 1.5.1 is required

Equal height rows in a flex container

for same height you should chage your css "display" Properties. For more detail see given example.

_x000D_
_x000D_
.list{_x000D_
  display: table;_x000D_
  flex-wrap: wrap;_x000D_
  max-width: 500px;_x000D_
}_x000D_
_x000D_
.list-item{_x000D_
  background-color: #ccc;_x000D_
  display: table-cell;_x000D_
  padding: 0.5em;_x000D_
  width: 25%;_x000D_
  margin-right: 1%;_x000D_
  margin-bottom: 20px;_x000D_
}_x000D_
.list-content{_x000D_
  width: 100%;_x000D_
}
_x000D_
<ul class="list">_x000D_
  <li class="list-item">_x000D_
    <div class="list-content">_x000D_
    <h2>box 1</h2>_x000D_
    <p>Lorem ipsum dolor sit amet, consectetur adipisicing elit. </p>_x000D_
    </div>_x000D_
  </li>_x000D_
  <li class="list-item">_x000D_
    <div class="list-content">_x000D_
    <h3>box 2</h3>_x000D_
    <p>Lorem ipsum dolor sit amet, consectetur adipisicing elit.</p>_x000D_
    </div>_x000D_
  </li>_x000D_
  _x000D_
    <li class="list-item">_x000D_
    <div class="list-content">_x000D_
    <h3>box 2</h3>_x000D_
    <p>Lorem ipsum dolor</p>_x000D_
    </div>_x000D_
  </li>_x000D_
  _x000D_
    <li class="list-item">_x000D_
    <div class="list-content">_x000D_
    <h3>box 2</h3>_x000D_
    <p>Lorem ipsum dolor</p>_x000D_
    </div>_x000D_
  </li>_x000D_
  <li class="list-item">_x000D_
    <div class="list-content">_x000D_
      <h1>h1</h1>_x000D_
    </div>_x000D_
  </li>
_x000D_
_x000D_
_x000D_

How to build a 2 Column (Fixed - Fluid) Layout with Twitter Bootstrap?

Update 2018

Bootstrap 4

Now that BS4 is flexbox, the fixed-fluid is simple. Just set the width of the fixed column, and use the .col class on the fluid column.

.sidebar {
    width: 180px;
    min-height: 100vh;
}

<div class="row">
    <div class="sidebar p-2">Fixed width</div>
    <div class="col bg-dark text-white pt-2">
        Content
    </div>
</div>

http://www.codeply.com/go/7LzXiPxo6a

Bootstrap 3..

One approach to a fixed-fluid layout is using media queries that align with Bootstrap's breakpoints so that you only use the fixed width columns are larger screens and then let the layout stack responsively on smaller screens...

@media (min-width:768px) {
  #sidebar {
      min-width: 300px;
      max-width: 300px;
  }
  #main {
      width:calc(100% - 300px);
  }
}

Working Bootstrap 3 Fixed-Fluid Demo

Related Q&A:
Fixed width column with a container-fluid in bootstrap
How to left column fixed and right scrollable in Bootstrap 4, responsive?

Max length for client ip address

Take it from someone who has tried it all three ways... just use a varchar(39)

The slightly less efficient storage far outweighs any benefit of having to convert it on insert/update and format it when showing it anywhere.

Difference between List, List<?>, List<T>, List<E>, and List<Object>

1) Correct

2) You can think of that one as "read only" list, where you don't care about the type of the items.Could e.g. be used by a method that is returning the length of the list.

3) T, E and U are the same, but people tend to use e.g. T for type, E for Element, V for value and K for key. The method that compiles says that it took an array of a certain type, and returns an array of the same type.

4) You can't mix oranges and apples. You would be able to add an Object to your String list if you could pass a string list to a method that expects object lists. (And not all objects are strings)

How do I fix a "Expected Primary-expression before ')' token" error?

showInventory(player);     // I get the error here.

void showInventory(player& obj) {   // By Johnny :D

this means that player is an datatype and showInventory expect an referance to an variable of type player.

so the correct code will be

  void showInventory(player& obj) {   // By Johnny :D
    for(int i = 0; i < 20; i++) {
        std::cout << "\nINVENTORY:\n" + obj.getItem(i);
        i++;
        std::cout << "\t\t\t" + obj.getItem(i) + "\n";
        i++;
    }
    }

players myPlayers[10];

    std::string toDo() //BY KEATON
    {
    std::string commands[5] =   // This is the valid list of commands.
        {"help", "inv"};

    std::string ans;
    std::cout << "\nWhat do you wish to do?\n>> ";
    std::cin >> ans;

    if(ans == commands[0]) {
        helpMenu();
        return NULL;
    }
    else if(ans == commands[1]) {
        showInventory(myPlayers[0]);     // or any other index,also is not necessary to have an array
        return NULL;
    }

}

Search all tables, all columns for a specific value SQL Server

You could query the sys.tables database view to get out the names of the tables, and then use this query to build yourself another query to do the update on the back of that. For instance:

select 'select * from '+name from sys.tables

will give you a script that will run a select * against all the tables in the system catalog, you could alter the string in the select clause to do your update, as long as you know the column name is the same on all the tables you wish to update, so your script would look something like:

select 'update '+name+' set comments = ''(*)''+comments where comments like ''%comment to be updated%'' ' from sys.tables

You could also then predicate on the tables query to only include tables that have a name in a certain format, or are in a subset you want to create the update script for.

C# how to change data in DataTable?

You should probably set the property dt.Columns["columnName"].ReadOnly = false; before.

Breaking out of a nested loop

Use a suitable guard in the outer loop. Set the guard in the inner loop before you break.

bool exitedInner = false;

for (int i = 0; i < N && !exitedInner; ++i) {

    .... some outer loop stuff

    for (int j = 0; j < M; ++j) {

        if (sometest) {
            exitedInner = true;
            break;
        }
    }
    if (!exitedInner) {
       ... more outer loop stuff
    }
}

Or better yet, abstract the inner loop into a method and exit the outer loop when it returns false.

for (int i = 0; i < N; ++i) {

    .... some outer loop stuff

    if (!doInner(i, N, M)) {
       break;
    }

    ... more outer loop stuff
}

java.lang.RuntimeException: Unable to start activity ComponentInfo

I had the same issue, I cleaned and rebuilt the project and it worked.

How to square all the values in a vector in R?

Try this (faster and simpler):

newData <- data^2

Spring mvc @PathVariable

Annotation which indicates that a method parameter should be bound to a URI template variable. Supported for RequestMapping annotated handler methods.

@RequestMapping(value = "/download/{documentId}", method = RequestMethod.GET)
public ModelAndView download(@PathVariable int documentId) {
    ModelAndView mav = new ModelAndView();
    Document document =  documentService.fileDownload(documentId);

    mav.addObject("downloadDocument", document);
    mav.setViewName("download");

    return mav;
}

Using if(isset($_POST['submit'])) to not display echo when script is open is not working

The $_post function need the name value like:

<input type="submit" value"Submit" name="example">

Call

$var = strip_tags($_POST['example']);
if (isset($var)){
    // your code here
}

Apache shutdown unexpectedly

I shut down the computer and restarted after installing the software and that fixed my problem.

NPM global install "cannot find module"

For some (like me) that nothing else worked, try this:

brew cleanup
brew link node
brew uninstall node
brew install node

Hope it helps someone :)

Adding and removing style attribute from div with jquery

If you are using jQuery, use css to add CSS

$("#voltaic_holder").css({'position': 'absolute',
    'top': '-75px'});

To remove CSS attributes

$("#voltaic_holder").css({'position': '',
    'top': ''});

Most efficient T-SQL way to pad a varchar on the left to a certain length?

Here's my solution, which avoids truncated strings and uses plain ol' SQL. Thanks to @AlexCuse, @Kevin and @Sklivvz, whose solutions are the foundation of this code.

 --[@charToPadStringWith] is the character you want to pad the string with.
declare @charToPadStringWith char(1) = 'X';

-- Generate a table of values to test with.
declare @stringValues table (RowId int IDENTITY(1,1) NOT NULL PRIMARY KEY, StringValue varchar(max) NULL);
insert into @stringValues (StringValue) values (null), (''), ('_'), ('A'), ('ABCDE'), ('1234567890');

-- Generate a table to store testing results in.
declare @testingResults table (RowId int IDENTITY(1,1) NOT NULL PRIMARY KEY, StringValue varchar(max) NULL, PaddedStringValue varchar(max) NULL);

-- Get the length of the longest string, then pad all strings based on that length.
declare @maxLengthOfPaddedString int = (select MAX(LEN(StringValue)) from @stringValues);
declare @longestStringValue varchar(max) = (select top(1) StringValue from @stringValues where LEN(StringValue) = @maxLengthOfPaddedString);
select [@longestStringValue]=@longestStringValue, [@maxLengthOfPaddedString]=@maxLengthOfPaddedString;

-- Loop through each of the test string values, apply padding to it, and store the results in [@testingResults].
while (1=1)
begin
    declare
        @stringValueRowId int,
        @stringValue varchar(max);

    -- Get the next row in the [@stringLengths] table.
    select top(1) @stringValueRowId = RowId, @stringValue = StringValue
    from @stringValues 
    where RowId > isnull(@stringValueRowId, 0) 
    order by RowId;

    if (@@ROWCOUNT = 0) 
        break;

    -- Here is where the padding magic happens.
    declare @paddedStringValue varchar(max) = RIGHT(REPLICATE(@charToPadStringWith, @maxLengthOfPaddedString) + @stringValue, @maxLengthOfPaddedString);

    -- Added to the list of results.
    insert into @testingResults (StringValue, PaddedStringValue) values (@stringValue, @paddedStringValue);
end

-- Get all of the testing results.
select * from @testingResults;

How to get all checked checkboxes

Get all the checked checkbox value in an array - one liner

_x000D_
_x000D_
const data = [...document.querySelectorAll('.inp:checked')].map(e => e.value);_x000D_
console.log(data);
_x000D_
<div class="row">_x000D_
    <input class="custom-control-input inp"type="checkbox" id="inlineCheckbox1" Checked value="option1"> _x000D_
    <label class="custom-control-label" for="inlineCheckbox1">Option1</label>_x000D_
    <input class="custom-control-input inp"  type="checkbox" id="inlineCheckbox1" value="option2"> _x000D_
    <label class="custom-control-label" for="inlineCheckbox1">Option2</label>_x000D_
    <input class="custom-control-input inp" Checked  type="checkbox" id="inlineCheckbox1" value="option3"> _x000D_
    <label class="custom-control-label" for="inlineCheckbox1">Option3</label>_x000D_
</div>
_x000D_
_x000D_
_x000D_

Deserialize a JSON array in C#

This code is working fine for me,

var a = serializer.Deserialize<List<Entity>>(json);

How do I use SELECT GROUP BY in DataTable.Select(Expression)?

DataTable's Select method only supports simple filtering expressions like {field} = {value}. It does not support complex expressions, let alone SQL/Linq statements.

You can, however, use Linq extension methods to extract a collection of DataRows then create a new DataTable.

dt = dt.AsEnumerable()
       .GroupBy(r => new {Col1 = r["Col1"], Col2 = r["Col2"]})
       .Select(g => g.OrderBy(r => r["PK"]).First())
       .CopyToDataTable();

How to compare two colors for similarity/difference

I expect you want to analyze a whole image at the end, don't you? So you could check for the smallest/highest difference to the identity color matrix.

Most math operations for processing graphics use matrices, because the possible algorithms using them are often faster than classical point by point distance and comparism calculations. (e.g. for operations using DirectX, OpenGL, ...)

So I think you should start here:

http://en.wikipedia.org/wiki/Identity_matrix

http://en.wikipedia.org/wiki/Matrix_difference_equation

... and as Beska already commented above:

This may not give the best "visible" difference...

Which means also that your algorithm depends onto your definiton of "similar to" if you are processing images.

How do I grant myself admin access to a local SQL Server instance?

Its actually enough to add -m to startup parameters on Sql Server Configuration Manager, restart service, go to ssms an add checkbox sysadmin on your account, then remove -m restart again and use as usual.

Database Engine Service Startup Options

-m Starts an instance of SQL Server in single-user mode.

Java time-based map/cache with expiring keys

Yes. Google Collections, or Guava as it is named now has something called MapMaker which can do exactly that.

ConcurrentMap<Key, Graph> graphs = new MapMaker()
   .concurrencyLevel(4)
   .softKeys()
   .weakValues()
   .maximumSize(10000)
   .expiration(10, TimeUnit.MINUTES)
   .makeComputingMap(
       new Function<Key, Graph>() {
         public Graph apply(Key key) {
           return createExpensiveGraph(key);
         }
       });

Update:

As of guava 10.0 (released September 28, 2011) many of these MapMaker methods have been deprecated in favour of the new CacheBuilder:

LoadingCache<Key, Graph> graphs = CacheBuilder.newBuilder()
    .maximumSize(10000)
    .expireAfterWrite(10, TimeUnit.MINUTES)
    .build(
        new CacheLoader<Key, Graph>() {
          public Graph load(Key key) throws AnyException {
            return createExpensiveGraph(key);
          }
        });

/usr/lib/libstdc++.so.6: version `GLIBCXX_3.4.15' not found

Sometimes you don't control the target machine (e.g. your library needs to run on a locked-down enterprise system). In such a case you will need to recompile your code using the version of GCC that corresponds to their GLIBCXX version. In that case, you can do the following:

  1. Look up the latest version of GLIBCXX supported by the target machine: strings /usr/lib/libstdc++.so.6 | grep GLIBC ... Say the version is 3.4.19.
  2. Use https://gcc.gnu.org/onlinedocs/libstdc++/manual/abi.html to find the corresponding GCC version. In our case, this is [4.8.3, 4.9.0).

Change the icon of the exe file generated from Visual Studio 2010

To specify an application icon

  1. In Solution Explorer, choose a project node (not the Solution node).
  2. On the menu bar, choose Project, Properties.
  3. When the Project Designer appears, choose the Application tab.
  4. In the Icon list, choose an icon (.ico) file.

To specify an application icon and add it to your project

  1. In Solution Explorer, choose a project node (not the Solution node).
  2. On the menu bar, choose Project, Properties.
  3. When the Project Designer appears, choose the Application tab.
  4. Near the Icon list, choose the button, and then browse to the location of the icon file that you want.

The icon file is added to your project as a content file.

reference : for details see here

How to convert between bytes and strings in Python 3?

This is a Python 101 type question,

It's a simple question but one where the answer is not so simple.


In python3, a "bytes" object represents a sequence of bytes, a "string" object represents a sequence of unicode code points.

To convert between from "bytes" to "string" and from "string" back to "bytes" you use the bytes.decode and string.encode functions. These functions take two parameters, an encoding and an error handling policy.

Sadly there are an awful lot of cases where sequences of bytes are used to represent text, but it is not necessarily well-defined what encoding is being used. Take for example filenames on unix-like systems, as far as the kernel is concerned they are a sequence of bytes with a handful of special values, on most modern distros most filenames will be UTF-8 but there is no gaurantee that all filenames will be.

If you want to write robust software then you need to think carefully about those parameters. You need to think carefully about what encoding the bytes are supposed to be in and how you will handle the case where they turn out not to be a valid sequence of bytes for the encoding you thought they should be in. Python defaults to UTF-8 and erroring out on any byte sequence that is not valid UTF-8.

print(bytesThing)

Python uses "repr" as a fallback conversion to string. repr attempts to produce python code that will recreate the object. In the case of a bytes object this means among other things escaping bytes outside the printable ascii range.

Regex for allowing alphanumeric,-,_ and space

Character sets will help out a ton here. You want to create a matching set for the characters that you want to validate:

  • You can match alphanumeric with a \w, which is the same as [A-Za-z0-9_] in JavaScript (other languages can differ).
  • That leaves - and spaces, which can be combined into a matching set such as [\w\- ]. However, you may want to consider using \s instead of just the space character (\s also matches tabs, and other forms of whitespace)
    • Note that I'm escaping - as \- so that the regex engine doesn't confuse it with a character range like A-Z
  • Last up, you probably want to ensure that the entire string matches by anchoring the start and end via ^ and $

The full regex you're probably looking for is:

/^[\w\-\s]+$/

(Note that the + indicates that there must be at least one character for it to match; use a * instead, if a zero-length string is also ok)

Finally, http://www.regular-expressions.info/ is an awesome reference


Bonus Points: This regex does not match non-ASCII alphas. Unfortunately, the regex engine in most browsers does not support named character sets, but there are some libraries to help with that.

For languages/platforms that do support named character sets, you can use /^[\p{Letter}\d\_\-\s]+$/

Body of Http.DELETE request in Angular2

Below is an example for Angular 6

deleteAccount(email) {
            const header: HttpHeaders = new HttpHeaders()
                .append('Content-Type', 'application/json; charset=UTF-8')
                .append('Authorization', 'Bearer ' + sessionStorage.getItem('accessToken'));
            const httpOptions = {
                headers: header,
                body: { Email: email }
            };
            return this.http.delete<any>(AppSettings.API_ENDPOINT + '/api/Account/DeleteAccount', httpOptions);
        }

Automatically create requirements.txt

Firstly, your project file must be a py file which is direct python file. If your file is in ipynb format, you can convert it to py type by using the line of code below:

jupyter nbconvert --to=python

Then, you need to install pipreqs library from cmd (terminal for mac).

pip install pipreqs

Now we can create txt file by using the code below. If you are in the same path with your file, you can just write ./ . Otherwise you need to give path of your file.

pipreqs ./

or

pipreqs /home/project/location

That will create a requirements.txt file for your project.

Can I animate absolute positioned element with CSS transition?

You forgot to define the default value for left so it doesn't know how to animate.

.test {
    left: 0;
    transition:left 1s linear;
}

See here: http://jsfiddle.net/shomz/yFy5n/5/

jQuery: print_r() display equivalent?

Look at this: http://phpjs.org/functions/index and find for print_r or use console.log() with firebug.

How to filter an array/object by checking multiple values

You can use .filter() method of the Array object:

var filtered = workItems.filter(function(element) {
   // Create an array using `.split()` method
   var cats = element.category.split(' ');

   // Filter the returned array based on specified filters
   // If the length of the returned filtered array is equal to
   // length of the filters array the element should be returned  
   return cats.filter(function(cat) {
       return filtersArray.indexOf(cat) > -1;
   }).length === filtersArray.length;
});

http://jsfiddle.net/6RBnB/

Some old browsers like IE8 doesn't support .filter() method of the Array object, if you are using jQuery you can use .filter() method of jQuery object.

jQuery version:

var filtered = $(workItems).filter(function(i, element) {
   var cats = element.category.split(' ');

    return $(cats).filter(function(_, cat) {
       return $.inArray(cat, filtersArray) > -1;
    }).length === filtersArray.length;
});

File Not Found when running PHP with Nginx

in case it helps someone, my issue seems to be just because I was using a subfolder under my home directory, even though permissions seem correct and I don't have SELinux or anything like that. changing it to be under /var/www/something/something made it work.

(if I ever found the real cause, and remember this answer, I'll update it)

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

The reason you get a Null Pointer Exception is because there is no key likesZZZ in your second example. Try:

def mymap = [name:"Gromit", likes:"cheese", id:1234]
def x = mymap.find{ it.key == "likes" }.value
if(x)
    println "x value: ${x}"

What is the difference between for and foreach?

I prefer the FOR loop in terms of performance. FOREACH is a little slow when you go with more number of items.

If you perform more business logic with the instance then FOREACH performs faster.

Demonstration: I created a list of 10000000 instances and looping with FOR and FOREACH.

Time took to loop:

  • FOREACH -> 53.852ms
  • FOR -> 28.9232ms

Below is the sample code.

class Program
{

    static void Main(string[] args)
    {
        List<TestClass> lst = new List<TestClass>();
        for (int i = 1; i <= 10000000; i++)
        {
            TestClass obj = new TestClass() {
                ID = i,
                Name = "Name" + i.ToString()
            };
            lst.Add(obj);
        }

        DateTime start = DateTime.Now;
        foreach (var obj in lst)
        {
            //obj.ID = obj.ID + 1;
            //obj.Name = obj.Name + "1";
        }
        DateTime end = DateTime.Now;
        var first = end.Subtract(start).TotalMilliseconds;

        start = DateTime.Now;
        for (int j = 0; j<lst.Count;j++)
        {
            //lst[j].ID = lst[j].ID + 1;
            //lst[j].Name = lst[j].Name + "1";
        }
        end = DateTime.Now;
        var second = end.Subtract(start).TotalMilliseconds;
    }
}

public class TestClass
{
    public long ID { get; set; }
    public string Name { get; set; }
}

If I uncomment the code inside the loop: Then, time took to loop:

  • FOREACH -> 2564.1405ms
  • FOR -> 2753.0017ms

Conclusion
If you do more business logic with the instance, then FOREACH is recommended. If you are not doing much logic with the instance, then FOR is recommended.

IE8 issue with Twitter Bootstrap 3

I faced the same problem, tried the first answer but something was missing.

If you guys are using Webpack, your css will be loaded as a style tag which is not supported by respond.js, it needs a file, so make sure bootstrap is loaded as a css file

Personally I used extract-text-webpack-plugin

const webpack = require("webpack")
const ExtractTextPlugin = require("extract-text-webpack-plugin")
const path = require("path")

module.exports = {
    context: __dirname+"/src",
    entry: "./index.js",
    output: {
        filename: "./dist/bundle.js",
        path: __dirname
    },
    plugins: [
        ...,
        new ExtractTextPlugin("./dist/bootstrap.css", {
            allChunks: true
        })
    ],
    module: {
        loaders: [
            ...,
            // your css loader excluding bootstrap
            {
                test: /\.css$/,
                loader: "style!css",
                exclude: [
                    path.resolve(__dirname, "node_modules/bootstrap/dist/css/bootstrap.css")
                ]
            },

            {
                // loads bootstrap as a file, change path accordingly if needs be, path needs to be absolute
                include: [
                    path.resolve(__dirname, "node_modules/bootstrap/dist/css/bootstrap.css")
                ],
                loader: ExtractTextPlugin.extract("style-loader", "css-loader?minimize")
            }
        ]
    }
}

Hope it will help you

Changing user agent on urllib2.urlopen

I answered a similar question a couple weeks ago.

There is example code in that question, but basically you can do something like this: (Note the capitalization of User-Agent as of RFC 2616, section 14.43.)

opener = urllib2.build_opener()
opener.addheaders = [('User-Agent', 'Mozilla/5.0')]
response = opener.open('http://www.stackoverflow.com')

Row count where data exists

lastrow = Sheet1.Range("A#").End(xlDown).Row

This is more easy to determine the row count.
Make sure you declare the right variable when it comes to larger rows.
By the way the '#' sign must be a number where you want to start the row count.

How do I convert the date from one format to another date object in another format without using any deprecated classes?

import java.text.DateFormat;
import java.text.SimpleDateFormat;
import java.util.Date;

             String fromDateFormat = "dd/MM/yyyy";
             String fromdate = 15/03/2018; //Take any date

             String CheckFormat = "dd MMM yyyy";//take another format like dd/MMM/yyyy
             String dateStringFrom;

             Date DF = new Date();


              try
              {
                 //DateFormatdf = DateFormat.getDateInstance(DateFormat.SHORT);
                 DateFormat FromDF = new SimpleDateFormat(fromDateFormat);
                 FromDF.setLenient(false);  // this is important!
                 Date FromDate = FromDF.parse(fromdate);
                 dateStringFrom = new 
                 SimpleDateFormat(CheckFormat).format(FromDate);
                 DateFormat FromDF1 = new SimpleDateFormat(CheckFormat);
                 DF=FromDF1.parse(dateStringFrom);
                 System.out.println(dateStringFrom);
              }
              catch(Exception ex)
              {

                  System.out.println("Date error");

              }

output:- 15/03/2018
         15 Mar 2018

location.host vs location.hostname and cross-browser compatibility?

If you are insisting to use the window.location.origin You can put this in top of your code before reading the origin

if (!window.location.origin) {
  window.location.origin = window.location.protocol + "//" + window.location.hostname + (window.location.port ? ':' + window.location.port: '');
}

Solution

PS: For the record, it was actually the original question. It was already edited :)

Convert array to JSON

because my array was like below: and I used .push function to create it dynamically

my_array = ["234", "23423"];

The only way I converted my array into json is

json = Object.assign({}, my_array);

String comparison - Android

if(gender.equals(g1)); <---
if(gender == "Female"); <---

You have semicolon after if.REMOVE IT.

CSV in Python adding an extra carriage return, on Windows

Note that if you use DictWriter, you will have a new line from the open function and a new line from the writerow function. You can use newline='' within the open function to remove the extra newline.

SQL Server 2012 column identity increment jumping from 6 to 1000+ on 7th entry

While trace flag 272 may work for many, it definitely won't work for hosted Sql Server Express installations. So, I created an identity table, and use this through an INSTEAD OF trigger. I'm hoping this helps someone else, and/or gives others an opportunity to improve my solution. The last line allows returning the last identity column added. Since I typically use this to add a single row, this works to return the identity of a single inserted row.

The identity table:

CREATE TABLE [dbo].[tblsysIdentities](
[intTableId] [int] NOT NULL,
[intIdentityLast] [int] NOT NULL,
[strTable] [varchar](100) NOT NULL,
[tsConcurrency] [timestamp] NULL,
CONSTRAINT [PK_tblsysIdentities] PRIMARY KEY CLUSTERED 
(
    [intTableId] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF,  ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
) ON [PRIMARY]

and the insert trigger:

-- INSERT --
IF OBJECT_ID ('dbo.trgtblsysTrackerMessagesIdentity', 'TR') IS NOT NULL
   DROP TRIGGER dbo.trgtblsysTrackerMessagesIdentity;
GO
CREATE TRIGGER trgtblsysTrackerMessagesIdentity
ON dbo.tblsysTrackerMessages
INSTEAD OF INSERT AS 
BEGIN
    DECLARE @intTrackerMessageId INT
    DECLARE @intRowCount INT

    SET @intRowCount = (SELECT COUNT(*) FROM INSERTED)

    SET @intTrackerMessageId = (SELECT intIdentityLast FROM tblsysIdentities WHERE intTableId=1)
    UPDATE tblsysIdentities SET intIdentityLast = @intTrackerMessageId + @intRowCount WHERE intTableId=1

    INSERT INTO tblsysTrackerMessages( 
    [intTrackerMessageId],
    [intTrackerId],
    [strMessage],
    [intTrackerMessageTypeId],
    [datCreated],
    [strCreatedBy])
    SELECT @intTrackerMessageId + ROW_NUMBER() OVER (ORDER BY [datCreated]) AS [intTrackerMessageId], 
    [intTrackerId],
   [strMessage],
   [intTrackerMessageTypeId],
   [datCreated],
   [strCreatedBy] FROM INSERTED;

   SELECT TOP 1 @intTrackerMessageId + @intRowCount FROM INSERTED;
END

How can I make content appear beneath a fixed DIV element?

Having just struggled with this and disliking some of the "hackier" solutions, I found this to be useful and clean:

#floatingMenu{
  position: sticky;
  top: 0;
}

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

For IBM DB2 (will double check this on Monday to be sure.)

SELECT TABNAME,COLNAME from SYSCAT.COLUMNS where TABNAME='MYTABLE'

Determining if an Object is of primitive type

As several people have already said, this is due to autoboxing.

You could create a utility method to check whether the object's class is Integer, Double, etc. But there is no way to know whether an object was created by autoboxing a primitive; once it's boxed, it looks just like an object created explicitly.

So unless you know for sure that your array will never contain a wrapper class without autoboxing, there is no real solution.

What's your most controversial programming opinion?

My controversial opinion: OO Programming is vastly overrated [and treated like a silver bullet], when it is really just another tool in the toolbox, nothing more!

I can not find my.cnf on my windows computer

Here is my answer:

  1. Win+R (shortcut for 'run'), type services.msc, Enter
  2. You should find an entry like 'MySQL56', right click on it, select properties
  3. You should see something like "D:/Program Files/MySQL/MySQL Server 5.6/bin\mysqld" --defaults-file="D:\ProgramData\MySQL\MySQL Server 5.6\my.ini" MySQL56

Full answer here: https://stackoverflow.com/a/20136523/1316649

Fill drop down list on selection of another drop down list

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Model:

namespace MvcApplicationrazor.Models
{
    public class CountryModel
    {
        public List<State> StateModel { get; set; }
        public SelectList FilteredCity { get; set; }
    }
    public class State
    {
        public int Id { get; set; }
        public string StateName { get; set; }
    }
    public class City
    {
        public int Id { get; set; }
        public int StateId { get; set; }
        public string CityName { get; set; }
    }
}   

Controller:

public ActionResult Index()
        {
            CountryModel objcountrymodel = new CountryModel();
            objcountrymodel.StateModel = new List<State>();
            objcountrymodel.StateModel = GetAllState();
            return View(objcountrymodel);
        }


        //Action result for ajax call
        [HttpPost]
        public ActionResult GetCityByStateId(int stateid)
        {
            List<City> objcity = new List<City>();
            objcity = GetAllCity().Where(m => m.StateId == stateid).ToList();
            SelectList obgcity = new SelectList(objcity, "Id", "CityName", 0);
            return Json(obgcity);
        }
        // Collection for state
        public List<State> GetAllState()
        {
            List<State> objstate = new List<State>();
            objstate.Add(new State { Id = 0, StateName = "Select State" });
            objstate.Add(new State { Id = 1, StateName = "State 1" });
            objstate.Add(new State { Id = 2, StateName = "State 2" });
            objstate.Add(new State { Id = 3, StateName = "State 3" });
            objstate.Add(new State { Id = 4, StateName = "State 4" });
            return objstate;
        }
        //collection for city
        public List<City> GetAllCity()
        {
            List<City> objcity = new List<City>();
            objcity.Add(new City { Id = 1, StateId = 1, CityName = "City1-1" });
            objcity.Add(new City { Id = 2, StateId = 2, CityName = "City2-1" });
            objcity.Add(new City { Id = 3, StateId = 4, CityName = "City4-1" });
            objcity.Add(new City { Id = 4, StateId = 1, CityName = "City1-2" });
            objcity.Add(new City { Id = 5, StateId = 1, CityName = "City1-3" });
            objcity.Add(new City { Id = 6, StateId = 4, CityName = "City4-2" });
            return objcity;
        }

View:

@model MvcApplicationrazor.Models.CountryModel
@{
    ViewBag.Title = "Index";
    Layout = "~/Views/Shared/_Layout.cshtml";
}

<script src="http://ajax.googleapis.com/ajax/libs/jqueryui/1.8/jquery-ui.min.js"></script>
<script language="javascript" type="text/javascript">
    function GetCity(_stateId) {
        var procemessage = "<option value='0'> Please wait...</option>";
        $("#ddlcity").html(procemessage).show();
        var url = "/Test/GetCityByStateId/";

        $.ajax({
            url: url,
            data: { stateid: _stateId },
            cache: false,
            type: "POST",
            success: function (data) {
                var markup = "<option value='0'>Select City</option>";
                for (var x = 0; x < data.length; x++) {
                    markup += "<option value=" + data[x].Value + ">" + data[x].Text + "</option>";
                }
                $("#ddlcity").html(markup).show();
            },
            error: function (reponse) {
                alert("error : " + reponse);
            }
        });

    }
</script>
<h4>
 MVC Cascading Dropdown List Using Jquery</h4>
@using (Html.BeginForm())
{
    @Html.DropDownListFor(m => m.StateModel, new SelectList(Model.StateModel, "Id", "StateName"), new { @id = "ddlstate", @style = "width:200px;", @onchange = "javascript:GetCity(this.value);" })
    <br />
    <br />
    <select id="ddlcity" name="ddlcity" style="width: 200px">

    </select>

    <br /><br />
  }

How can I align YouTube embedded video in the center in bootstrap

<div>
    <iframe id="myFrame" src="https://player.vimeo.com/video/12345678?autoplay=1" width="640" height="360" frameborder="0" allowfullscreen> . 
    </iframe>
</div>

<script>
    function myFunction() {
        var wscreen = window.innerWidth;
        var hscreen = window.innerHeight;

        document.getElementById("myFrame").width = wscreen ;
        document.getElementById("myFrame").height = hscreen ;
    }

    myFunction();

    window.addEventListener('resize', function(){ myFunction(); });
</script>

this works on Vimeo adding an id myFrame to the iframe

java comparator, how to sort by integer?

One simple way is

Comparator<Dog> ageAscendingComp = ...;
Comparator<Dog> ageDescendingComp = Collections.reverseOrder(ageAscendingComp);
// then call the sort method

On a side note, Dog should really not implement Comparator. It means you have to do strange things like

Collections.sort(myList, new Dog("Rex", 4));
// ^-- why is a new dog being made? What are we even sorting by?!
Collections.sort(myList, myList.get(0));
// ^-- or perhaps more confusingly

Rather you should make Compartors as separate classes.

eg.

public class DogAgeComparator implments Comparator<Dog> {
    public int compareTo(Dog d1, Dog d2) {
        return d1.getAge() - d2.getAge();
    }
}

This has the added benefit that you can use the name of the class to say how the Comparator will sort the list. eg.

Collections.sort(someDogs, new DogNameComparator());
// now in name ascending order

Collections.sort(someDogs, Collections.reverseOrder(new DogAgeComparator()));
// now in age descending order

You should also not not have Dog implement Comparable. The Comparable interface is used to denote that there is some inherent and natural way to order these objects (such as for numbers and strings). Now this is not the case for Dog objects as sometimes you may wish to sort by age and sometimes you may wish to sort by name.

No line-break after a hyphen

You could also wrap the relevant text with

<span style="white-space: nowrap;"></span>

How to urlencode a querystring in Python?

For use in scripts/programs which need to support both python 2 and 3, the six module provides quote and urlencode functions:

>>> from six.moves.urllib.parse import urlencode, quote
>>> data = {'some': 'query', 'for': 'encoding'}
>>> urlencode(data)
'some=query&for=encoding'
>>> url = '/some/url/with spaces and %;!<>&'
>>> quote(url)
'/some/url/with%20spaces%20and%20%25%3B%21%3C%3E%26'

How to send email by using javascript or jquery

You can do it server-side with nodejs.

Check out the popular Nodemailer package. There are plenty of transports and plugins for integrating with services like AWS SES and SendGrid!

The following example uses SES transport (Amazon SES):

let nodemailer = require("nodemailer");
let aws = require("aws-sdk");
let transporter = nodemailer.createTransport({
  SES: new aws.SES({ apiVersion: "2010-12-01" })
});

How to encode a string in JavaScript for displaying in HTML?

If you want to use a library rather than doing it yourself:

The most commonly used way is using jQuery for this purpose:

var safestring = $('<div>').text(unsafestring).html();

If you want to to encode all the HTML entities you will have to use a library or write it yourself.

You can use a more compact library than jQuery, like HTML Encoder and Decode

How do I remove blank elements from an array?

In my project I use delete:

cities.delete("")

'LIKE ('%this%' OR '%that%') and something=else' not working

Break out the LIKE clauses into 2 separate statements, i.e.:

(fieldname1 LIKE '%this%' or fieldname1 LIKE '%that%' ) and something=else

Styling a input type=number

UPDATE 17/03/2017

Original solution won't work anymore. The spinners are part of shadow dom. For now just to hide in chrome use:

_x000D_
_x000D_
input[type=number]::-webkit-inner-spin-button {_x000D_
  -webkit-appearance: none;_x000D_
}
_x000D_
<input type="number" />
_x000D_
_x000D_
_x000D_

or to always show:

_x000D_
_x000D_
input[type=number]::-webkit-inner-spin-button {_x000D_
  opacity: 1;_x000D_
}
_x000D_
<input type="number" />
_x000D_
_x000D_
_x000D_

You can try the following but keep in mind that works only for Chrome:

_x000D_
_x000D_
input[type=number]::-webkit-inner-spin-button { _x000D_
    -webkit-appearance: none;_x000D_
    cursor:pointer;_x000D_
    display:block;_x000D_
    width:8px;_x000D_
    color: #333;_x000D_
    text-align:center;_x000D_
    position:relative;_x000D_
}_x000D_
_x000D_
input[type=number]::-webkit-inner-spin-button:before,_x000D_
input[type=number]::-webkit-inner-spin-button:after {_x000D_
    content: "^";_x000D_
    position:absolute;_x000D_
    right: 0;_x000D_
}_x000D_
_x000D_
input[type=number]::-webkit-inner-spin-button:before {_x000D_
    top:0px;_x000D_
}_x000D_
_x000D_
input[type=number]::-webkit-inner-spin-button:after {_x000D_
    bottom:0px;_x000D_
    -webkit-transform: rotate(180deg);_x000D_
}
_x000D_
<input type="number" />
_x000D_
_x000D_
_x000D_

@viewChild not working - cannot read property nativeElement of undefined

What happens is when these elements are called before the DOM is loaded these kind of errors come up. Always use:

 window.onload = function(){
     this.keywordsInput.nativeElement.focus();
 }

Working with time DURATION, not time of day

Highlight the cell(s)/column which you want as Duration, right click on the mouse to "Format Cells". Go to "Custom" and look for "h:mm" if you want to input duration in hour and minutes format. If you want to include seconds as well, click on "h:mm:ss". You can even add up the total duration after that.

Hope this helps.

How to use OpenFileDialog to select a folder?

Here is another solution, that has all the source available in a single, simple ZIP file.

It presents the OpenFileDialog with additional windows flags that makes it work like the Windows 7+ Folder Selection dialog.

Per the website, it is public domain: "There’s no license as such as you are free to take and do with the code what you will."

Archive.org links:

What is the difference between Multiple R-squared and Adjusted R-squared in a single-variate least squares regression?

The R-squared is not dependent on the number of variables in the model. The adjusted R-squared is.

The adjusted R-squared adds a penalty for adding variables to the model that are uncorrelated with the variable your trying to explain. You can use it to test if a variable is relevant to the thing your trying to explain.

Adjusted R-squared is R-squared with some divisions added to make it dependent on the number of variables in the model.

How to split a string by spaces in a Windows batch file?

The following code will split a string with an arbitrary number of substrings:

@echo off
setlocal ENABLEDELAYEDEXPANSION

REM Set a string with an arbitrary number of substrings separated by semi colons
set teststring=The;rain;in;spain

REM Do something with each substring
:stringLOOP
    REM Stop when the string is empty
    if "!teststring!" EQU "" goto END

    for /f "delims=;" %%a in ("!teststring!") do set substring=%%a

        REM Do something with the substring - 
        REM we just echo it for the purposes of demo
        echo !substring!

REM Now strip off the leading substring
:striploop
    set stripchar=!teststring:~0,1!
    set teststring=!teststring:~1!

    if "!teststring!" EQU "" goto stringloop

    if "!stripchar!" NEQ ";" goto striploop

    goto stringloop
)

:END
endlocal

Trying to make bootstrap modal wider

If you need this solution for only few types of modals just use style="width:90%" attribute.

example:

div class="modal-dialog modal-lg" style="width:90%"

note: this will change only this particular modal

How can I find the version of php that is running on a distinct domain name?

Sometimes, PHP will emit a X-Powered-By: response header which you can look at e.g. using Firebug.

If this setting (controlled by the ini setting expose_php) is turned off (it often is), there is no way to tell the PHP version used - and rightly so. What PHP version is running is none of the outside world's business, and it's good to obscure this from a security perspective.

Increasing Google Chrome's max-connections-per-server limit to more than 6

IE is even worse with 2 connection per domain limit. But I wouldn't rely on fixing client browsers. Even if you have control over them, browsers like chrome will auto update and a future release might behave differently than you expect. I'd focus on solving the problem within your system design.

Your choices are to:

  1. Load the images in sequence so that only 1 or 2 XHR calls are active at a time (use the success event from the previous image to check if there are more images to download and start the next request).

  2. Use sub-domains like serverA.myphotoserver.com and serverB.myphotoserver.com. Each sub domain will have its own pool for connection limits. This means you could have 2 requests going to 5 different sub-domains if you wanted to. The downfall is that the photos will be cached according to these sub-domains. BTW, these don't need to be "mirror" domains, you can just make additional DNS pointers to the exact same website/server. This means you don't have the headache of administrating many servers, just one server with many DNS records.

LINQ - Full Outer Join

Full outer join for two or more tables: First extract the column that you want to join on.

var DatesA = from A in db.T1 select A.Date; 
var DatesB = from B in db.T2 select B.Date; 
var DatesC = from C in db.T3 select C.Date;            

var Dates = DatesA.Union(DatesB).Union(DatesC); 

Then use left outer join between the extracted column and main tables.

var Full_Outer_Join =

(from A in Dates
join B in db.T1
on A equals B.Date into AB 

from ab in AB.DefaultIfEmpty()
join C in db.T2
on A equals C.Date into ABC 

from abc in ABC.DefaultIfEmpty()
join D in db.T3
on A equals D.Date into ABCD

from abcd in ABCD.DefaultIfEmpty() 
select new { A, ab, abc, abcd })
.AsEnumerable();

PHP - warning - Undefined property: stdClass - fix?

isset() is fine for top level, but empty() is much more useful to find whether nested values are set. Eg:

if(isset($json['foo'] && isset($json['foo']['bar'])) {
    $value = $json['foo']['bar']
}

Or:

if (!empty($json['foo']['bar']) {
    $value = $json['foo']['bar']
}

What is the best way to iterate over a dictionary?

var dictionary = new Dictionary<string, int>
{
    { "Key", 12 }
};

var aggregateObjectCollection = dictionary.Select(
    entry => new AggregateObject(entry.Key, entry.Value));

How to fill color in a cell in VBA?

  1. Use conditional formatting instead of VBA to highlight errors.

  2. Using a VBA loop like the one you posted will take a long time to process

  3. the statement If cell.Value = "#N/A" Then will never work. If you insist on using VBA to highlight errors, try this instead.

    Sub ColorCells()

    Dim Data As Range
    Dim cell As Range
    Set currentsheet = ActiveWorkbook.Sheets("Comparison")
    Set Data = currentsheet.Range("A2:AW1048576")
    
    For Each cell In Data
    
    If IsError(cell.Value) Then
       cell.Interior.ColorIndex = 3
    End If
    Next
    
    End Sub
    
  4. Be prepared for a long wait, since the procedure loops through 51 million cells

  5. There are more efficient ways to achieve what you want to do. Update your question if you have a change of mind.

How to extract request http headers from a request using NodeJS connect

var host = req.headers['host']; 

The headers are stored in a JavaScript object, with the header strings as object keys.

Likewise, the user-agent header could be obtained with

var userAgent = req.headers['user-agent']; 

Sleep function in ORACLE

If executed within "sqlplus", you can execute a host operating system command "sleep" :

!sleep 1

or

host sleep 1

Get webpage contents with Python?

Also you can use faster_than_requests package. That's very fast and simple:

import faster_than_requests as r
content = r.get2str("http://test.com/")

Look at this comparison:

enter image description here

Importing data from a JSON file into R

import httr package

library(httr)

Get the url

url <- "http://www.omdbapi.com/?apikey=72bc447a&t=Annie+Hall&y=&plot=short&r=json"
resp <- GET(url)

Print content of resp as text

content(resp, as = "text")

Print content of resp

content(resp)

Use content() to get the content of resp, but this time do not specify a second argument. R figures out automatically that you're dealing with a JSON, and converts the JSON to a named R list.

How to import a class from default package

Create a new package And then move the classes of default package in new package and use those classes

How do I make entire div a link?

You need to assign display: block; property to the wrapping anchor. Otherwise it won't wrap correctly.

<a style="display:block" href="http://justinbieber.com">
  <div class="xyz">My div contents</div>
</a>

Getting Google+ profile picture url with user_id

UPDATE: The method below DOES NOT WORK since 2015

It is possible to get the profile picture, and you can even set the size of it:

https://plus.google.com/s2/photos/profile/<user_id>?sz=<your_desired_size>

Example: My profile picture, with size set to 100 pixels:

https://plus.google.com/s2/photos/profile/116018066779980863044?sz=100

Usage with an image tag:

<img src="https://plus.google.com/s2/photos/profile/116018066779980863044?sz=100" width="100" height="100">

Hope you get it working!

How do I include a Perl module that's in a different directory?

EDIT: Putting the right solution first, originally from this question. It's the only one that searches relative to the module directory:

use FindBin;                 # locate this script
use lib "$FindBin::Bin/..";  # use the parent directory
use yourlib;

There's many other ways that search for libraries relative to the current directory. You can invoke perl with the -I argument, passing the directory of the other module:

perl -I.. yourscript.pl

You can include a line near the top of your perl script:

use lib '..';

You can modify the environment variable PERL5LIB before you run the script:

export PERL5LIB=$PERL5LIB:..

The push(@INC) strategy can also work, but it has to be wrapped in BEGIN{} to make sure that the push is run before the module search:

BEGIN {push @INC, '..'}
use yourlib;

Create a new file in git bash

Yes, it is. Just create files in the windows explorer and git automatically detects these files as currently untracked. Then add it with the command you already mentioned.

git add does not create any files. See also http://gitref.org/basic/#add

Github probably creates the file with touch and adds the file for tracking automatically. You can do this on the bash as well.

How to convert a Django QuerySet to a list

You can directly convert using the list keyword. For example:

obj=emp.objects.all()
list1=list(obj)

Using the above code you can directly convert a query set result into a list.

Here list is keyword and obj is result of query set and list1 is variable in that variable we are storing the converted result which in list.

How can I use Timer (formerly NSTimer) in Swift?

NSTimer has been renamed to Timer in Swift 4.2. this syntax will work in 4.2:

let timer = Timer.scheduledTimer(timeInterval: 1.0, target: self, selector: #selector(UIMenuController.update), userInfo: nil, repeats: true)

XmlSerializer: remove unnecessary xsi and xsd namespaces

There is an alternative - you can provide a member of type XmlSerializerNamespaces in the type to be serialized. Decorate it with the XmlNamespaceDeclarations attribute. Add the namespace prefixes and URIs to that member. Then, any serialization that does not explicitly provide an XmlSerializerNamespaces will use the namespace prefix+URI pairs you have put into your type.

Example code, suppose this is your type:

[XmlRoot(Namespace = "urn:mycompany.2009")]
public class Person {
  [XmlAttribute] 
  public bool Known;
  [XmlElement]
  public string Name;
  [XmlNamespaceDeclarations]
  public XmlSerializerNamespaces xmlns;
}

You can do this:

var p = new Person
  { 
      Name = "Charley",
      Known = false, 
      xmlns = new XmlSerializerNamespaces()
  }
p.xmlns.Add("",""); // default namespace is emoty
p.xmlns.Add("c", "urn:mycompany.2009");

And that will mean that any serialization of that instance that does not specify its own set of prefix+URI pairs will use the "p" prefix for the "urn:mycompany.2009" namespace. It will also omit the xsi and xsd namespaces.

The difference here is that you are adding the XmlSerializerNamespaces to the type itself, rather than employing it explicitly on a call to XmlSerializer.Serialize(). This means that if an instance of your type is serialized by code you do not own (for example in a webservices stack), and that code does not explicitly provide a XmlSerializerNamespaces, that serializer will use the namespaces provided in the instance.

Pie chart with jQuery

jqPlot looks pretty good and it is open source.

Here's a link to the most impressive and up-to-date jqPlot examples.

did you specify the right host or port? error on Kubernetes

I was also getting same below error:

Unable to connect to the server: dial tcp [::1]:8080: connectex: No connection could be made because the target machine actively refused it.

Then I just execute below command and found everything working fine.

PS C:> .\minikube.exe start

Starting local Kubernetes v1.10.0 cluster... Starting VM... Downloading Minikube ISO 150.53 MB / 150.53 MB [============================================] 100.00% 0s Getting VM IP address... Moving files into cluster... Downloading kubeadm v1.10.0 Downloading kubelet v1.10.0 Finished Downloading kubelet v1.10.0 Finished Downloading kubeadm v1.10.0 Setting up certs... Connecting to cluster... Setting up kubeconfig... Starting cluster components... Kubectl is now configured to use the cluster. Loading cached images from config file. PS C:> .\minikube.exe start Starting local Kubernetes v1.10.0 cluster... Starting VM... Getting VM IP address... Moving files into cluster... Setting up certs... Connecting to cluster... Setting up kubeconfig... Starting cluster components... Kubectl is now configured to use the cluster.

How to get visitor's location (i.e. country) using geolocation?

For developers looking for a full-featured geolocation utility, you can have a look at geolocator.js (I'm the author).

Example below will first try HTML5 Geolocation API to obtain the exact coordinates. If fails or rejected, it will fallback to Geo-IP look-up. Once it gets the coordinates, it will reverse-geocode the coordinates into an address.

var options = {
    enableHighAccuracy: true,
    timeout: 6000,
    maximumAge: 0,
    desiredAccuracy: 30,
    fallbackToIP: true, // if HTML5 geolocation fails or rejected
    addressLookup: true, // get detailed address information
    timezone: true, 
    map: "my-map" // this will even create a map for you
};

geolocator.locate(options, function (err, location) {
    console.log(err || location);
});

It supports geo-location (via HTML5 or IP lookups), geocoding, address look-ups (reverse geocoding), distance & durations, timezone information and more...

Access elements in json object like an array

I found a straight forward way of solving this, with the use of JSON.parse.

Let's assume the json below is inside the variable jsontext.

[
  ["Blankaholm", "Gamleby"],
  ["2012-10-23", "2012-10-22"],
  ["Blankaholm. Under natten har det varit inbrott", "E22 i med Gamleby. Singelolycka. En bilist har.],
  ["57.586174","16.521841"], ["57.893162","16.406090"]
]

The solution is this:

var parsedData = JSON.parse(jsontext);

Now I can access the elements the following way:

var cities = parsedData[0];

GET URL parameter in PHP

Please post your code,

<?php
    echo $_GET['link'];
?>

or

<?php
    echo $_REQUEST['link'];
?>

do work...

T-SQL CASE Clause: How to specify WHEN NULL

The WHEN part is compared with ==, but you can't really compare with NULL. Try

CASE WHEN last_name is NULL  THEN ... ELSE .. END

instead or COALESCE:

COALESCE(' '+last_name,'')

(' '+last_name is NULL when last_name is NULL, so it should return '' in that case)

jQuery Validate Plugin - Trigger validation of single field

When you set up your validation, you should be saving the validator object. you can use this to validate individual fields.

<script type="text/javascript">
var _validator;
$(function () {    
     _validator = $("#form").validate();   
});

function doSomething() {    
     _validator.element($('#someElement'));
}
</script> 

-- cross posted with this similar question

Vue.js get selected option on @change

Use v-model to bind the value of selected option's value. Here is an example.

<select name="LeaveType" @change="onChange($event)" class="form-control" v-model="key">
   <option value="1">Annual Leave/ Off-Day</option>
   <option value="2">On Demand Leave</option>
</select>
<script>
var vm = new Vue({
    data: {
        key: ""
    },
    methods: {
        onChange(event) {
            console.log(event.target.value)
        }
    }
}
</script>

More reference can been seen from here.

Generate random numbers using C++11 random library

You've got two common situations. The first is that you want random numbers and aren't too fussed about the quality or execution speed. In that case, use the following macro

#define uniform() (rand()/(RAND_MAX + 1.0))

that gives you p in the range 0 to 1 - epsilon (unless RAND_MAX is bigger than the precision of a double, but worry about that when you come to it).

int x = (int) (uniform() * N);

Now gives a random integer on 0 to N -1.

If you need other distributions, you have to transform p. Or sometimes it's easier to call uniform() several times.

If you want repeatable behaviour, seed with a constant, otherwise seed with a call to time().

Now if you are bothered about quality or run time performance, rewrite uniform(). But otherwise don't touch the code. Always keep uniform() on 0 to 1 minus epsilon. Now you can wrap the C++ random number library to create a better uniform(), but that's a sort of medium-level option. If you are bothered about the characteristics of the RNG, then it's also worth investing a bit of time to understand how the underlying methods work, then provide one. So you've got complete control of the code, and you can guarantee that with the same seed, the sequence will always be exactly the same, regardless of platform or which version of C++ you are linking to.

Allow Google Chrome to use XMLHttpRequest to load a URL from a local file

Using --disable-web-security switch is quite dangerous! Why disable security at all while you can just allow XMLHttpRequest to access files from other files using --allow-file-access-from-files switch?

Before using these commands be sure to end all running instances of Chrome.

On Windows:

chrome.exe --allow-file-access-from-files

On Mac:

open /Applications/Google\ Chrome.app/ --args --allow-file-access-from-files

Discussions of this "feature" of Chrome:

Disable clipboard prompt in Excel VBA on workbook close

If you don't want to save any changes and don't want that Save prompt while saving an Excel file using Macro then this piece of code may helpful for you

Sub Auto_Close()

     ThisWorkbook.Saved = True

End Sub

Because the Saved property is set to True, Excel responds as though the workbook has already been saved and no changes have occurred since that last save, so no Save prompt.

How do I install a plugin for vim?

Those two commands will create a ~/.vim/vim-haml/ directory with the ftplugin, syntax, etc directories in it. Those directories need to be immediately in the ~/.vim directory proper or ~/.vim/vim-haml needs to be added to the list of paths that vim searches for plugins.

Edit:

I recently decided to tweak my vim config and in the process wound up writing the following rakefile. It only works on Mac/Linux, but the advantage over cp versions is that it's completely safe (symlinks don't overwrite existing files, uninstall only deletes symlinks) and easy to keep things updated.

# Easily install vim plugins from a source control checkout (e.g. Github)
#
# alias vim-install=rake -f ~/.vim/rakefile-vim-install
# vim-install
# vim-install uninstall

require 'ftools'
require 'fileutils'

task :default => :install
desc "Install a vim plugin the lazy way"
task :install do
  vim_dir      = File.expand_path("~/.vim")
  plugin_dir   = Dir.pwd

  if not (FileTest.exists? File.join(plugin_dir,".git") or
          FileTest.exists? File.join(plugin_dir,".svn") or
          FileTest.exists? File.join(plugin_dir,".hg"))
      puts "#{plugin_dir} isn't a source controlled directory. Aborting."
      exit 1
  end

  Dir['**/'].each do |d|
    FileUtils.mkdir_p File.join(vim_dir, d)
  end

  Dir["**/*.{txt,snippet,snippets,vim,js,wsf}"].each do |f|
    ln File.join(plugin_dir, f), File.join(vim_dir,f)
  end

  boldred = "\033[1;31m"
  clear = "\033[0m"
  puts "\nDone. Remember to #{boldred}:helptags ~/.vim/doc#{clear}"
end

task :uninstall do
  vim_dir      = File.expand_path("~/.vim")
  plugin_dir   = Dir.pwd
  Dir["**/*.{txt,snippet,snippets,vim}"].each do |f|
    safe_rm File.join(vim_dir, f)
  end
end

def nicename(path)
    boldgreen = "\033[1;32m"
    clear = "\033[0m"
    return "#{boldgreen}#{File.join(path.split('/')[-2..-1])}#{clear}\t"
end

def ln(src, dst)
    begin
        FileUtils.ln_s src, dst
        puts "    Symlink #{nicename src}\t => #{nicename dst}"
    rescue Errno::EEXIST
        puts "  #{nicename dst} exists! Skipping."
    end
end

def cp(src, dst)
  puts "    Copying #{nicename src}\t=> #{nicename dst}"
  FileUtils.cp src, dst
end

def safe_rm(target)
    if FileTest.exists? target and FileTest.symlink? target
        puts "    #{nicename target} removed."
        File.delete target
    else
        puts "  #{nicename target} is not a symlink. Skipping"
    end
end

How to change the current URL in javascript?

What you're doing is appending a "1" (the string) to your URL. If you want page 1.html link to page 2.html you need to take the 1 out of the string, add one to it, then reassemble the string.

Why not do something like this:

var url = 'http://mywebsite.com/1.html';
var pageNum = parseInt( url.split("/").pop(),10 );
var nextPage = 'http://mywebsite.com/'+(pageNum+1)+'.html';

nextPage will contain the url http://mywebsite.com/2.html in this case. Should be easy to put in a function if needed.

What is the difference between an interface and abstract class?

Key Points:

  • Abstract class can have property, Data fields ,Methods (complete / incomplete) both.
  • If method or Properties define in abstract keyword that must override in derived class.(its work as a tightly coupled functionality)
  • If define abstract keyword for method or properties in abstract class you can not define body of method and get/set value for properties and that must override in derived class.
  • Abstract class does not support multiple inheritance.
  • Abstract class contains Constructors.
  • An abstract class can contain access modifiers for the subs, functions, properties.
  • Only Complete Member of abstract class can be Static.
  • An interface can inherit from another interface only and cannot inherit from an abstract class, where as an abstract class can inherit from another abstract class or another interface.

Advantage:

  • It is a kind of contract that forces all the subclasses to carry on the same hierarchies or standards.
  • If various implementations are of the same kind and use common behavior or status then abstract class is better to use.
  • If we add a new method to an abstract class then we have the option of providing default implementation and therefore all the existing code might work properly.
  • Its allow fast execution than interface.(interface Requires more time to find the actual method in the corresponding classes.)
  • It can use for tight and loosely coupling.

find details here... http://pradeepatkari.wordpress.com/2014/11/20/interface-and-abstract-class-in-c-oops/

.gitignore and "The following untracked working tree files would be overwritten by checkout"

In order to save the modified files and to use the modified content later. I found this error while i try checking out a branch and when trying to rebase. Try Git stash

git stash

How to add column if not exists on PostgreSQL?

For those who use Postgre 9.5+(I believe most of you do), there is a quite simple and clean solution

ALTER TABLE if exists <tablename> add if not exists <columnname> <columntype>

Get JSF managed bean by name in any Servlet related class

I had same requirement.

I have used the below way to get it.

I had session scoped bean.

@ManagedBean(name="mb")
@SessionScopedpublic 
class ManagedBean {
     --------
}

I have used the below code in my servlet doPost() method.

ManagedBean mb = (ManagedBean) request.getSession().getAttribute("mb");

it solved my problem.

Padding characters in printf

If you are ending the pad characters at some fixed column number, then you can overpad and cut to length:

# Previously defined:
# PROC_NAME
# PROC_STATUS

PAD="--------------------------------------------------"
LINE=$(printf "%s %s" "$PROC_NAME" "$PAD" | cut -c 1-${#PAD})
printf "%s %s\n" "$LINE" "$PROC_STATUS"

Get the current user, within an ApiController action, without passing the userID as a parameter

Hint lies in Webapi2 auto generated account controller

Have this property with getter defined as

public string UserIdentity
        {
            get
            {
                var user = UserManager.FindByName(User.Identity.Name);
                return user;//user.Email
            }
        }

and in order to get UserManager - In WebApi2 -do as Romans (read as AccountController) do

public ApplicationUserManager UserManager
        {
            get { return HttpContext.Current.GetOwinContext().GetUserManager<ApplicationUserManager>(); }
        }

This should be compatible in IIS and self host mode

Set width of dropdown element in HTML select dropdown options

Small And Better One

var i = 0;
$("#container > option").each(function(){ 
    if($(this).val().length > i) {
        i = $(this).val().length;

        console.log(i);
        console.log($(this).val());
    }
});

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

Sometimes, due to the heavy size of the script and data, we encounter this type of error. Server needs sufficient memory to execute and give the result. We can simply increase the memory size, per query.

You just need to go to the sql server properties > Memory tab (left side)> Now set the maximum memory limit you want to add.

Also, there is an option at the top, "Results to text", which consume less memory as compare to option "Results to grid", we can also go for Result to Text for less memory execution.

How to delete columns that contain ONLY NAs?

Another option with Filter

Filter(function(x) !all(is.na(x)), df)

NOTE: Data from @Simon O'Hanlon's post.

Copy all values in a column to a new column in a pandas dataframe

The problem is in the line before the one that throws the warning. When you create df_2 that's where you're creating a copy of a slice of a dataframe. Instead, when you create df_2, use .copy() and you won't get that warning later on.

df_2 = df[df['B'] == 'b.2'].copy()

How to check if a string is null in python

Try this:

if cookie and not cookie.isspace():
    # the string is non-empty
else:
    # the string is empty

The above takes in consideration the cases where the string is None or a sequence of white spaces.

How do I properly clean up Excel interop objects?

"Never use two dots with COM objects" is a great rule of thumb to avoid leakage of COM references, but Excel PIA can lead to leakage in more ways than apparent at first sight.

One of these ways is subscribing to any event exposed by any of the Excel object model's COM objects.

For example, subscribing to the Application class's WorkbookOpen event.

Some theory on COM events

COM classes expose a group of events through call-back interfaces. In order to subscribe to events, the client code can simply register an object implementing the call-back interface and the COM class will invoke its methods in response to specific events. Since the call-back interface is a COM interface, it is the duty of the implementing object to decrement the reference count of any COM object it receives (as a parameter) for any of the event handlers.

How Excel PIA expose COM Events

Excel PIA exposes COM events of Excel Application class as conventional .NET events. Whenever the client code subscribes to a .NET event (emphasis on 'a'), PIA creates an instance of a class implementing the call-back interface and registers it with Excel.

Hence, a number of call-back objects get registered with Excel in response to different subscription requests from the .NET code. One call-back object per event subscription.

A call-back interface for event handling means that, PIA has to subscribe to all interface events for every .NET event subscription request. It cannot pick and choose. On receiving an event call-back, the call-back object checks if the associated .NET event handler is interested in the current event or not and then either invokes the handler or silently ignores the call-back.

Effect on COM instance reference counts

All these call-back objects do not decrement the reference count of any of the COM objects they receive (as parameters) for any of the call-back methods (even for the ones that are silently ignored). They rely solely on the CLR garbage collector to free up the COM objects.

Since GC run is non-deterministic, this can lead to the holding off of Excel process for a longer duration than desired and create an impression of a 'memory leak'.

Solution

The only solution as of now is to avoid the PIA’s event provider for the COM class and write your own event provider which deterministically releases COM objects.

For the Application class, this can be done by implementing the AppEvents interface and then registering the implementation with Excel by using IConnectionPointContainer interface. The Application class (and for that matter all COM objects exposing events using callback mechanism) implements the IConnectionPointContainer interface.

Multiple conditions in a C 'for' loop

There is an operator in C called the comma operator. It executes each expression in order and returns the value of the last statement. It's also a sequence point, meaning each expression is guaranteed to execute in completely and in order before the next expression in the series executes, similar to && or ||.

How to get named excel sheets while exporting from SSRS

Necromancing, just in case all the links go dark:

  1. Add a group to your report
    Also, be advised to set the sort order of the group expression here, so the tabs will be alphabetically sorted (or however you want it sorted).

    1. Add a group to your report

    • 'Zeilengruppe' means 'Target group'
    • 'Gruppeneigenschaften' means 'Group properties'
  2. Set the page break in the group properties 2. Set the page break in the group properties

    • 'Seitenumbruche' means 'Page break'
    • 'Zwischen den einzelnen Instanzen einer Gruppe' means 'Between the individual instances of a group'
  3. Now you need to set the PageName of the Tablix Member (group), NOT the PageName of the Tablix itselfs.
    If you got the right object, if will say "Tablix Member" (Tablix-Element in German) in the title box of the properties grid. If it's the wrong object, it will say only "table/tablix" (without member) in the property grid's title box.

  4. Note: If you get the tablix instead of the tablix member, it will put the same tab name in every tab, followed by a (tabNum)! If that happens, you now know what the problem is. Tablix Member

MultiTabExcelFile

Android check internet connection

I had issues with the IsInternetAvailable answer not testing for cellular networks, rather only if wifi was connected. This answer works for both wifi and mobile data:

How to check network connection enable or disable in WIFI and 3G(data plan) in mobile?

What's the difference between [ and [[ in Bash?

In bash, contrary to [, [[ prevents word splitting of variable values.

proper way to logout from a session in PHP

Session_unset(); only destroys the session variables. To end the session there is another function called session_destroy(); which also destroys the session .

update :

In order to kill the session altogether, like to log the user out, the session id must also be unset. If a cookie is used to propagate the session id (default behavior), then the session cookie must be deleted. setcookie() may be used for that

How to get the last element of a slice?

For just reading the last element of a slice:

sl[len(sl)-1]

For removing it:

sl = sl[:len(sl)-1]

See this page about slice tricks

Python Pandas replicate rows in dataframe

Appending and concatenating is usually slow in Pandas so I recommend just making a new list of the rows and turning that into a dataframe (unless appending a single row or concatenating a few dataframes).

import pandas as pd

df = pd.DataFrame([
[1,1,'2010-02-05',24924.5,False],
[1,1,'2010-02-12',46039.49,True],
[1,1,'2010-02-19',41595.55,False],
[1,1,'2010-02-26',19403.54,False],
[1,1,'2010-03-05',21827.9,False],
[1,1,'2010-03-12',21043.39,False],
[1,1,'2010-03-19',22136.64,False],
[1,1,'2010-03-26',26229.21,False],
[1,1,'2010-04-02',57258.43,False]
], columns=['Store','Dept','Date','Weekly_Sales','IsHoliday'])

temp_df = []
for row in df.itertuples(index=False):
    if row.IsHoliday:
        temp_df.extend([list(row)]*5)
    else:
        temp_df.append(list(row))

df = pd.DataFrame(temp_df, columns=df.columns)

Failed to resolve: com.google.firebase:firebase-core:16.0.1

If you use Firebase in a library module, you need to apply the google play services gradle plugin to it in addition to the app(s) module(s), but also, you need to beware of version 4.2.0 (and 4.1.0) which are broken, and use version 4.0.2 instead.

Here's the issue: https://github.com/google/play-services-plugins/issues/22

Select second last element with css

In CSS3 you have:

:nth-last-child(2)

See: https://developer.mozilla.org/en-US/docs/Web/CSS/:nth-last-child

nth-last-child Browser Support:

  • Chrome 2
  • Firefox 3.5
  • Opera 9.5, 10
  • Safari 3.1, 4
  • Internet Explorer 9

Under what circumstances can I call findViewById with an Options Menu / Action Bar item?

I am trying to obtain a handle on one of the views in the Action Bar

I will assume that you mean something established via android:actionLayout in your <item> element of your <menu> resource.

I have tried calling findViewById(R.id.menu_item)

To retrieve the View associated with your android:actionLayout, call findItem() on the Menu to retrieve the MenuItem, then call getActionView() on the MenuItem. This can be done any time after you have inflated the menu resource.

Table columns, setting both min and max width with css

Tables work differently; sometimes counter-intuitively.

The solution is to use width on the table cells instead of max-width.

Although it may sound like in that case the cells won't shrink below the given width, they will actually.
with no restrictions on c, if you give the table a width of 70px, the widths of a, b and c will come out as 16, 42 and 12 pixels, respectively.
With a table width of 400 pixels, they behave like you say you expect in your grid above.
Only when you try to give the table too small a size (smaller than a.min+b.min+the content of C) will it fail: then the table itself will be wider than specified.

I made a snippet based on your fiddle, in which I removed all the borders and paddings and border-spacing, so you can measure the widths more accurately.

_x000D_
_x000D_
table {_x000D_
  width: 70px;_x000D_
}_x000D_
_x000D_
table, tbody, tr, td {_x000D_
  margin: 0;_x000D_
  padding: 0;_x000D_
  border: 0;_x000D_
  border-spacing: 0;_x000D_
}_x000D_
_x000D_
.a, .c {_x000D_
  background-color: red;_x000D_
}_x000D_
_x000D_
.b {_x000D_
  background-color: #F77;_x000D_
}_x000D_
_x000D_
.a {_x000D_
  min-width: 10px;_x000D_
  width: 20px;_x000D_
  max-width: 20px;_x000D_
}_x000D_
_x000D_
.b {_x000D_
  min-width: 40px;_x000D_
  width: 45px;_x000D_
  max-width: 45px;_x000D_
}_x000D_
_x000D_
.c {}
_x000D_
<table>_x000D_
  <tr>_x000D_
    <td class="a">A</td>_x000D_
    <td class="b">B</td>_x000D_
    <td class="c">C</td>_x000D_
  </tr>_x000D_
</table>
_x000D_
_x000D_
_x000D_

How to use a typescript enum value in an Angular2 ngSwitch statement

You can create a custom decorator to add to your component to make it aware of enums.

myenum.enum.ts:

export enum MyEnum {
    FirstValue,
    SecondValue
}

myenumaware.decorator.ts

import { MyEnum } from './myenum.enum';

export function MyEnumAware(constructor: Function) {
    constructor.prototype.MyEnum = MyEnum;
}

enum-aware.component.ts

import { Component } from '@angular2/core';
import { MyEnum } from './myenum.enum';
import { MyEnumAware } from './myenumaware.decorator';

@Component({
  selector: 'enum-aware',
  template: `
    <div [ngSwitch]="myEnumValue">
      <div *ngSwitchCase="MyEnum.FirstValue">
        First Value
      </div>
      <div *ngSwitchCase="MyEnum.SecondValue">
        Second Value
      </div>
    </div>
    <button (click)="toggleValue()">Toggle Value</button>
  `,
})
@MyEnumAware // <---------------!!!
export default class EnumAwareComponent {
  myEnumValue: MyEnum = MyEnum.FirstValue;

  toggleValue() {
    this.myEnumValue = this.myEnumValue === MyEnum.FirstValue
        ? MyEnum.SecondValue : MyEnum.FirstValue;
  }
}

Is it possible to create a remote repo on GitHub from the CLI without opening browser?

Both the accepted answer and the most-voted answer so far are now outdated. Password authentication is deprecated and it will be removed on November 13, 2020 at 16:00 UTC.

The way to use GitHub API now is via personal access tokens.

You need to (replace ALL CAPS keywords):

  1. Create a personal access token via the website. Yes, you have to use the browser, but it is only once for all future accesses. Store the token securely.
  2. Create the repo via
curl -H 'Authorization: token MY_ACCESS_TOKEN' https://api.github.com/user/repos  -d '{"name":"REPO"}'

or, to make it private from the start:

curl -H 'Authorization: token MY_ACCESS_TOKEN' https://api.github.com/user/repos -d '{"name":"REPO", "private":"true"}'
  1. Add the new origin and push to it:
git remote add origin [email protected]:USER/REPO.git
git push origin master

This has the disadvantage that you have to type the token each time, and that it appears in your bash history.

To avoid this, you can

  1. Store the header in a file (let's call it, say, HEADER_FILE)
Authorization: token MY_ACCESS_TOKEN
  1. Have curl read from the file
curl -H @HEADER_FILE https://api.github.com/user/repos -d '{"name":"REPO"}' # public repo
curl -H @HEADER_FILE https://api.github.com/user/repos -d '{"name":"REPO", "private":"true"}' # private repo
  1. To make things more secure, you could set access permissions to 400 and the user to root
chmod 400 HEADER_FILE
sudo chown root:root HEADER_FILE
  1. Now sudo will be needed to access the header file
sudo curl -H @HEADER_FILE https://api.github.com/user/repos -d '{"name":"REPO"}' # public repo
sudo curl -H @HEADER_FILE https://api.github.com/user/repos -d '{"name":"REPO", "private":"true"}' # private repo

Is there a better alternative than this to 'switch on type'?

I would create an interface with whatever name and method name that would make sense for your switch, let's call them respectively: IDoable that tells to implement void Do().

public interface IDoable
{
    void Do();
}

public class A : IDoable
{
    public void Hop() 
    {
        // ...
    }

    public void Do()
    {
        Hop();
    }
}

public class B : IDoable
{
    public void Skip() 
    {
        // ...
    }

    public void Do()
    {
        Skip();
    }
}

and change the method as follows:

void Foo<T>(T obj)
    where T : IDoable
{
    // ...
    obj.Do();
    // ...
}

At least with that you are safe at the compilation-time and I suspect that performance-wise it's better than checking type at runtime.

How to get a path to the desktop for current user in C#?

string path = Environment.GetFolderPath(Environment.SpecialFolder.Desktop);

Handler "ExtensionlessUrlHandler-Integrated-4.0" has a bad module "ManagedPipelineHandler" in its module list

The problem

You are using SimpleWorkerRequest in a scenario that it wasn't designed for. You are using it inside of IIS. If you look at the prior MSDN link (emphasis is mine):

Provides a simple implementation of the HttpWorkerRequest abstract class that can be used to host ASP.NET applications outside an Internet Information Services (IIS) application. You can employ SimpleWorkerRequest directly or extend it.

Also, if you look at the MSDN documentation for the System.Web.Hosting namespace (SimpleWorkerRequest is in this namespace), you will also see something similar to the above (again, emphasis is mine):

The System.Web.Hosting namespace provides the functionality for hosting ASP.NET applications from managed applications outside Microsoft Internet Information Services (IIS).

The solution

I would recommend removing the call to SimpleWorkerRequest. Instead, you can use a Microsoft solution to make sure your web site automatically starts up after it recycles. What you need is the Microsoft Application Initialization Module for IIS 7.5. It is not complicated to configure, but you need to understand the exact options. This is why I would also recommend the Application Initialization UI for IIS 7.5. The UI is written by an MSDN blogger.

So what exactly does the Microsoft solution do? It does what you are trying to do - IIS sends a "get" request to your website after the application pool is started.

How to properly use the "choices" field option in Django

The cleanest solution is to use the django-model-utils library:

from model_utils import Choices

class Article(models.Model):
    STATUS = Choices('draft', 'published')
    status = models.CharField(choices=STATUS, default=STATUS.draft, max_length=20)

https://django-model-utils.readthedocs.io/en/latest/utilities.html#choices

Date query with ISODate in mongodb doesn't seem to work

Try this:

{ "dt" : { "$gte" : ISODate("2013-10-01") } }

Loading PictureBox Image from resource file with path (Part 3)

Setting "Copy to Output Directory" to "Copy always" or "Copy if newer" may help for you.

Your PicPath is a relative path that is converted into an absolute path at some time while loading the image. Most probably you will see that there are no images on the specified location if you use Path.GetFullPath(PicPath) in Debug.

How to import a Python class that is in a directory above?

@gimel's answer is correct if you can guarantee the package hierarchy he mentions. If you can't -- if your real need is as you expressed it, exclusively tied to directories and without any necessary relationship to packaging -- then you need to work on __file__ to find out the parent directory (a couple of os.path.dirname calls will do;-), then (if that directory is not already on sys.path) prepend temporarily insert said dir at the very start of sys.path, __import__, remove said dir again -- messy work indeed, but, "when you must, you must" (and Pyhon strives to never stop the programmer from doing what must be done -- just like the ISO C standard says in the "Spirit of C" section in its preface!-).

Here is an example that may work for you:

import sys
import os.path
sys.path.append(
    os.path.abspath(os.path.join(os.path.dirname(__file__), os.path.pardir)))

import module_in_parent_dir

How to construct a REST API that takes an array of id's for the resources

 api.com/users?id=id1,id2,id3,id4,id5
 api.com/users?ids[]=id1&ids[]=id2&ids[]=id3&ids[]=id4&ids[]=id5

IMO, above calls does not looks RESTful, however these are quick and efficient workaround (y). But length of the URL is limited by webserver, eg tomcat.

RESTful attempt:

POST http://example.com/api/batchtask

   [
    {
      method : "GET",
      headers : [..],
      url : "/users/id1"
    },
    {
      method : "GET",
      headers : [..],
      url : "/users/id2"
    }
   ]

Server will reply URI of newly created batchtask resource.

201 Created
Location: "http://example.com/api/batchtask/1254"

Now client can fetch batch response or task progress by polling

GET http://example.com/api/batchtask/1254


This is how others attempted to solve this issue:

Permissions error when connecting to EC2 via SSH on Mac OSx

Two possibilities I can think of, although they are both mentioned in the link you referenced:

  1. You're not specifying the correct SSH keypair file or user name in the ssh command you're using to log into the server:

    ssh -i [full path to keypair file] root@[EC2 instance hostname or IP address]

  2. You don't have the correct permissions on the keypair file; you should use

    chmod 600 [keypair file]

to ensure that only you can read or write the file.

Try using the -v option with ssh to get more info on where exactly it's failing, and post back here if you''d like more help.

[Update]: OK, so this is what you should have seen if everything was set up properly:

debug1: Authentications that can continue: publickey,gssapi-with-mic
debug1: Next authentication method: publickey
debug1: Trying private key: ec2-keypair
debug1: read PEM private key done: type RSA
debug1: Authentication succeeded (publickey).

Are you running the ssh command from the directory containing the ec2-keypair file ? If so, try specifying -i ./ec2-keypair just to eliminate path problems. Also check "ls -l [full path to ec2-keypair]" file and make sure the permissions are 600 (displayed as rw-------). If none of that works, I'd suspect the contents of the keypair file, so try recreating it using the steps in your link.

POST: sending a post request in a url itself

In Java you can use GET which shows requested data on URL.But POST method cannot , because POST has body but GET donot have body.

Get first element of Series without knowing the index

Use iloc to access by position (rather than label):

In [11]: df = pd.DataFrame([[1, 2], [3, 4]], ['a', 'b'], ['A', 'B'])

In [12]: df
Out[12]: 
   A  B
a  1  2
b  3  4

In [13]: df.iloc[0]  # first row in a DataFrame
Out[13]: 
A    1
B    2
Name: a, dtype: int64

In [14]: df['A'].iloc[0]  # first item in a Series (Column)
Out[14]: 1

How to publish a Web Service from Visual Studio into IIS?

If using Visual Studio 2010 you can right-click on the project for the service, and select properties. Then select the Web tab. Under the Servers section you can configure the URL. There is also a button to create the virtual directory.

Carriage return in C?

From 5.2.2/2 (character display semantics) :

\b (backspace) Moves the active position to the previous position on the current line. If the active position is at the initial position of a line, the behavior of the display device is unspecified.

\n (new line) Moves the active position to the initial position of the next line.

\r (carriage return) Moves the active position to the initial position of the current line.

Here, your code produces :

  • <new_line>ab
  • \b : back one character
  • write si : overrides the b with s (producing asi on the second line)
  • \r : back at the beginning of the current line
  • write ha : overrides the first two characters (producing hai on the second line)

In the end, the output is :

\nhai

Taking pictures with camera on Android programmatically

For those who came here looking for a way to take pictures/photos programmatically using both Android's Camera and Camera2 API, take a look at the open source sample provided by Google itself here.

How to connect to remote Redis server?

There are two ways to connect remote redis server using redis-cli:

1. Using host & port individually as options in command

redis-cli -h host -p port

If your instance is password protected

redis-cli -h host -p port -a password

e.g. if my-web.cache.amazonaws.com is the host url and 6379 is the port

Then this will be the command:

redis-cli -h my-web.cache.amazonaws.com -p 6379

if 92.101.91.8 is the host IP address and 6379 is the port:

redis-cli -h 92.101.91.8 -p 6379

command if the instance is protected with password pass123:

redis-cli -h my-web.cache.amazonaws.com -p 6379 -a pass123

2. Using single uri option in command

redis-cli -u redis://password@host:port

command in a single uri form with username & password

redis-cli -u redis://username:password@host:port

e.g. for the same above host - port configuration command would be

redis-cli -u redis://[email protected]:6379

command if username is also provided user123

redis-cli -u redis://user123:[email protected]:6379

This detailed answer was for those who wants to check all options. For more information check documentation: Redis command line usage

Counting unique values in a column in pandas dataframe like in Qlik?

Count distinct values, use nunique:

df['hID'].nunique()
5

Count only non-null values, use count:

df['hID'].count()
8

Count total values including null values, use the size attribute:

df['hID'].size
8

Edit to add condition

Use boolean indexing:

df.loc[df['mID']=='A','hID'].agg(['nunique','count','size'])

OR using query:

df.query('mID == "A"')['hID'].agg(['nunique','count','size'])

Output:

nunique    5
count      5
size       5
Name: hID, dtype: int64

The service cannot be started, either because it is disabled or because it has no enabled devices associated with it

Try to open Services Window, by writing services.msc into Start->Run and hit Enter.

When window appears, then find SQL Browser service, right click and choose Properties, and then in dropdown list choose Automatic, or Manual, whatever you want, and click OK. Eventually, if not started immediately, you can again press right click on this service and click Start.

Progress during large file copy (Copy-Item & Write-Progress?)

I haven't heard about progress with Copy-Item. If you don't want to use any external tool, you can experiment with streams. The size of buffer varies, you may try different values (from 2kb to 64kb).

function Copy-File {
    param( [string]$from, [string]$to)
    $ffile = [io.file]::OpenRead($from)
    $tofile = [io.file]::OpenWrite($to)
    Write-Progress -Activity "Copying file" -status "$from -> $to" -PercentComplete 0
    try {
        [byte[]]$buff = new-object byte[] 4096
        [long]$total = [int]$count = 0
        do {
            $count = $ffile.Read($buff, 0, $buff.Length)
            $tofile.Write($buff, 0, $count)
            $total += $count
            if ($total % 1mb -eq 0) {
                Write-Progress -Activity "Copying file" -status "$from -> $to" `
                   -PercentComplete ([long]($total * 100 / $ffile.Length))
            }
        } while ($count -gt 0)
    }
    finally {
        $ffile.Dispose()
        $tofile.Dispose()
        Write-Progress -Activity "Copying file" -Status "Ready" -Completed
    }
}

<hr> tag in Twitter Bootstrap not functioning correctly?

By default, the hr element in Twitter Bootstrap CSS file has a top and bottom margin of 18px. That's what creates a gap. If you want the gap to be smaller you'll need to adjust margin property of the hr element.

In your example, do something like this:

.container hr {
margin: 2px 0;
}

Can you delete multiple branches in one command with Git?

You can use git branch --list to list the eligible branches, and use git branch -D/-d to remove the eligible branches.

One liner example:

git branch -d `git branch --list '3.2.*'`

How to add an image to a JPanel?

  1. There shouldn't be any problem (other than any general problems you might have with very large images).
  2. If you're talking about adding multiple images to a single panel, I would use ImageIcons. For a single image, I would think about making a custom subclass of JPanel and overriding its paintComponent method to draw the image.
  3. (see 2)

How to loop through files matching wildcard in batch file

There is a tool usually used in MS Servers (as far as I can remember) called forfiles:

The link above contains help as well as a link to the microsoft download page.

Convert stdClass object to array in PHP

I have a function myOrderId($_GET['ID']); which returns multidimensional OBJ. as a String.

None of other 1 liner wokred for me.

This both worked:

$array = (array)json_decode(myOrderId($_GET['ID']), True);

$array = json_decode(json_decode(json_encode(myOrderId($_GET['ID']))), True);

Align image in center and middle within div

You can do this easily by using display:flex css property

#over {
  height: 100%;
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: center;
}