Programs & Examples On #Xattribute

How to select a specific node with LINQ-to-XML

I'd use something like:

dim customer = (from c in xmldoc...<Customer> 
                where c.<ID>.Value=22 
                select c).SingleOrDefault 

Edit:

missed the c# tag, sorry......the example is in VB.NET

Hash string in c#

using System.Security.Cryptography;

public static byte[] GetHash(string inputString)
{
    using (HashAlgorithm algorithm = SHA256.Create())
        return algorithm.ComputeHash(Encoding.UTF8.GetBytes(inputString));
}

public static string GetHashString(string inputString)
{
    StringBuilder sb = new StringBuilder();
    foreach (byte b in GetHash(inputString))
        sb.Append(b.ToString("X2"));

    return sb.ToString();
}

Additional Notes

  • Since MD5 and SHA1 are obsolete and insecure algorithms, this solution uses SHA256. Alternatively, you can use BCrypt or Scrypt as pointed out in comments.
  • Also, consider "salting" your hashes and use proven cryptographic algorithms, as pointed out in comments.

Change a Rails application to production

How to setup and run a Rails 4 app in Production mode (step-by-step) using Apache and Phusion Passenger:

Normally you would be able to enter your Rails project, rails s, and get a development version of your app at http://something.com:3000. Production mode is a little trickier to configure.

I've been messing around with this for a while, so I figured I'd write this up for the newbies (such as myself). There are a few little tweaks which are spread throughout the internet and figured this might be easier.

  1. Refer to this guide for core setup of the server (CentOS 6, but it should apply to nearly all Linux flavors): https://www.digitalocean.com/community/tutorials/how-to-setup-a-rails-4-app-with-apache-and-passenger-on-centos-6

  2. Make absolute certain that after Passenger is set up you've edited the /etc/httpd/conf/httpd.conf file to reflect your directory structure. You want to point DocumentRoot to your Rails project /public folder Anywhere in the httpd.conf file that has this sort of dir: /var/www/html/your_application/public needs to be updated or everything will get very frustrating. I cannot stress this enough.

  3. Reboot the server (or Apache at the very least - service httpd restart )

  4. Enter your Rails project folder /var/www/html/your_application and start the migration with rake db:migrate. Make certain that a database table exists, even if you plan on adding tables later (this is also part of step 1).

  5. RAILS_ENV=production rake secret - this will create a secret_key that you can add to config/secrets.yml . You can copy/paste this into config/secrets.yml for the sake of getting things running, although I'd recommend you don't do this. Personally, I do this step to make sure everything else is working, then change it back and source it later.

  6. RAILS_ENV=production rake db:migrate

  7. RAILS_ENV=production rake assets:precompile if you are serving static assets. This will push js, css, image files into the /public folder.

  8. RAILS_ENV=production rails s

At this point your app should be available at http://something.com/whatever instead of :3000. If not, passenger-memory-stats and see if there an entry like 908 469.7 MB 90.9 MB Passenger RackApp: /var/www/html/projectname

I've probably missed something heinous, but this has worked for me in the past.

Creating and throwing new exception

To call a specific exception such as FileNotFoundException use this format

if (-not (Test-Path $file)) 
{
    throw [System.IO.FileNotFoundException] "$file not found."
}

To throw a general exception use the throw command followed by a string.

throw "Error trying to do a task"

When used inside a catch, you can provide additional information about what triggered the error

Build error: You must add a reference to System.Runtime

Install the .NET Runtime as well as the targeting pack for the .NET version you're targeting.

The developer pack is just these two things bundled together but as of today doesn't seem to have a 4.6 version so you'll have to install the two items separately.

Downloads can be found here: http://blogs.msdn.com/b/dotnet/p/dotnet_sdks.aspx#

Can there exist two main methods in a Java program?

That would be compilable code, as long as StringSecond was a class. However, if by "main method" you mean a second entry point into the program, then the answer to your question is still no. Only the first option (public static void main(String[] args)) can be the entry point into your program.

Note, however, that if you were to place a second main(String[]) method in a different class (but in the same project) you could have multiple possible entry points into the project which you could then choose from. But this cannot conflict with the principles of overriding or overloading.

Also note that one source of confusion in this area, especially for introductory programmers, is that public static void main(String[] args) and public static void main(String ... args) are both used as entry points and are treated as having the same method signature.

What is the use of "assert"?

Watch out for the parentheses. As has been pointed out above, in Python 3, assert is still a statement, so by analogy with print(..), one may extrapolate the same to assert(..) or raise(..) but you shouldn't.

This is important because:

assert(2 + 2 == 5, "Houston we've got a problem")

won't work, unlike

assert 2 + 2 == 5, "Houston we've got a problem"

The reason the first one will not work is that bool( (False, "Houston we've got a problem") ) evaluates to True.

In the statement assert(False), these are just redundant parentheses around False, which evaluate to their contents. But with assert(False,) the parentheses are now a tuple, and a non-empty tuple evaluates to True in a boolean context.

Get filename in batch for loop

If you want to remain both filename (only) and extension, you may use %~nxF:

FOR /R C:\Directory %F in (*.*) do echo %~nxF

Filter Pyspark dataframe column with None value

You can use Column.isNull / Column.isNotNull:

df.where(col("dt_mvmt").isNull())

df.where(col("dt_mvmt").isNotNull())

If you want to simply drop NULL values you can use na.drop with subset argument:

df.na.drop(subset=["dt_mvmt"])

Equality based comparisons with NULL won't work because in SQL NULL is undefined so any attempt to compare it with another value returns NULL:

sqlContext.sql("SELECT NULL = NULL").show()
## +-------------+
## |(NULL = NULL)|
## +-------------+
## |         null|
## +-------------+


sqlContext.sql("SELECT NULL != NULL").show()
## +-------------------+
## |(NOT (NULL = NULL))|
## +-------------------+
## |               null|
## +-------------------+

The only valid method to compare value with NULL is IS / IS NOT which are equivalent to the isNull / isNotNull method calls.

PHP Redirect to another page after form submit

Once had this issue, thought it reasonable to share how I resolved it;

I think the way to do that in php is to use the header function as:

header ("Location: exampleFile.php");

You could just enclose that header file in an if statement so that it redirects only when a certain condition is met, as in:

if (isset($_POST['submit'])){   header("Location: exampleFile.php")   }

Hope that helps.

Javascript wait() function

Javascript isn't threaded, so a "wait" would freeze the entire page (and probably cause the browser to stop running the script entirely).

To specifically address your problem, you should remove the brackets after donothing in your setTimeout call, and make waitsecs a number not a string:

console.log('before');
setTimeout(donothing,500); // run donothing after 0.5 seconds
console.log('after');

But that won't stop execution; "after" will be logged before your function runs.

To wait properly, you can use anonymous functions:

console.log('before');
setTimeout(function(){
    console.log('after');
},500);

All your variables will still be there in the "after" section. You shouldn't chain these - if you find yourself needing to, you need to look at how you're structuring the program. Also you may want to use setInterval / clearInterval if it needs to loop.

How to disable back swipe gesture in UINavigationController on iOS 7

It worked for me for most of the viewcontrollers.

self.navigationController?.interactivePopGestureRecognizer?.isEnabled = false

It wasn't not working for some viewcontrollers like UIPageViewController. On UIPageViewController's pagecontentviewcontroller below code worked for me.

override func viewDidLoad() {
   self.navigationController?.interactivePopGestureRecognizer?.isEnabled = false
   self.navigationController?.interactivePopGestureRecognizer?.delegate = self
}
override func viewWillDisappear(_ animated: Bool) {
   self.navigationController?.interactivePopGestureRecognizer?.isEnabled = false
   self.navigationController?.interactivePopGestureRecognizer?.delegate = nil
}

On UIGestureRecognizerDelegate,

func gestureRecognizerShouldBegin(_ gestureRecognizer: UIGestureRecognizer) -> Bool {
   if gestureRecognizer == self.navigationController?.interactivePopGestureRecognizer {
      return false
}
      return true
}

random number generator between 0 - 1000 in c#

Use this:

static int RandomNumber(int min, int max)
{
    Random random = new Random(); return random.Next(min, max);

}

This is example for you to modify and use in your application.

What is the simplest way to SSH using Python?

Your definition of "simplest" is important here - simple code means using a module (though "large external library" is an exaggeration).

I believe the most up-to-date (actively developed) module is paramiko. It comes with demo scripts in the download, and has detailed online API documentation. You could also try PxSSH, which is contained in pexpect. There's a short sample along with the documentation at the first link.

Again with respect to simplicity, note that good error-detection is always going to make your code look more complex, but you should be able to reuse a lot of code from the sample scripts then forget about it.

javax.xml.bind.UnmarshalException: unexpected element. Expected elements are (none)

Alternatively if you want to persist in using the DocumentType class. Then you could just add the following annotation on top of your DocumentType class.

    @XmlRootElement(name="document")

Note: the String value "document" refers to the name of the root tag of the xml message.

How do I generate sourcemaps when using babel and webpack?

On Webpack 2 I tried all 12 devtool options. The following options link to the original file in the console and preserve line numbers. See the note below re: lines only.

https://webpack.js.org/configuration/devtool

devtool best dev options

                                build   rebuild      quality                       look
eval-source-map                 slow    pretty fast  original source               worst
inline-source-map               slow    slow         original source               medium
cheap-module-eval-source-map    medium  fast         original source (lines only)  worst
inline-cheap-module-source-map  medium  pretty slow  original source (lines only)  best

lines only

Source Maps are simplified to a single mapping per line. This usually means a single mapping per statement (assuming you author is this way). This prevents you from debugging execution on statement level and from settings breakpoints on columns of a line. Combining with minimizing is not possible as minimizers usually only emit a single line.

REVISITING THIS

On a large project I find ... eval-source-map rebuild time is ~3.5s ... inline-source-map rebuild time is ~7s

How do you check that a number is NaN in JavaScript?

It seems that isNaN() is not supported in Node.js out of the box.
I worked around with

var value = 1;
if (parseFloat(stringValue)+"" !== "NaN") value = parseFloat(stringValue);

Can anyone recommend a simple Java web-app framework?

Haven't tried it myself, but I think

http://www.playframework.org/

has a lot of potential...

coming from php and classic asp, it's the first java web framework that sounds promising to me....

Edit by original question asker - 2011-06-09

Just wanted to provide an update.

I went with Play and it was exactly what I asked for. It requires very little configuration, and just works out of the box. It is unusual in that it eschews some common Java best-practices in favor of keeping things as simple as possible.

In particular, it makes heavy use of static methods, and even does some introspection on the names of variables passed to methods, something not supported by the Java reflection API.

Play's attitude is that its first goal is being a useful web framework, and sticking to common Java best-practices and idioms is secondary to that. This approach makes sense to me, but Java purists may not like it, and would be better-off with Apache Wicket.

In summary, if you want to build a web-app with convenience and simplicity comparable to a framework like Ruby on Rails, but in Java and with the benefit of Java's tooling (eg. Eclipse), then Play Framework is a great choice.

how to use substr() function in jquery?

Extract characters from a string:

var str = "Hello world!";
var res = str.substring(1,4);

The result of res will be:

ell

http://www.w3schools.com/jsref/jsref_substring.asp

$('.dep_buttons').mouseover(function(){
    $(this).text().substring(0,25);
    if($(this).text().length > 30) {
        $(this).stop().animate({height:"150px"},150);
    }
    $(".dep_buttons").mouseout(function(){
        $(this).stop().animate({height:"40px"},150);
    });
});

Difference between maven scope compile and provided for JAR packaging

From the Maven Doc:

  • compile

    This is the default scope, used if none is specified. Compile dependencies are available in all classpaths of a project. Furthermore, those dependencies are propagated to dependent projects.

  • provided

    This is much like compile, but indicates you expect the JDK or a container to provide the dependency at runtime. For example, when building a web application for the Java Enterprise Edition, you would set the dependency on the Servlet API and related Java EE APIs to scope provided because the web container provides those classes. This scope is only available on the compilation and test classpath, and is not transitive.

Recap:

  • dependencies are not transitive (as you mentioned)
  • provided scope is only available on the compilation and test classpath, whereas compile scope is available in all classpaths.
  • provided dependencies are not packaged

Proper usage of Java -D command-line parameters

That should be:

java -Dtest="true" -jar myApplication.jar

Then the following will return the value:

System.getProperty("test");

The value could be null, though, so guard against an exception using a Boolean:

boolean b = Boolean.parseBoolean( System.getProperty( "test" ) );

Note that the getBoolean method delegates the system property value, simplifying the code to:

if( Boolean.getBoolean( "test" ) ) {
   // ...
}

How can I find which tables reference a given table in Oracle SQL Developer?

SQL Developer 4.1, released in May of 2015, added a Model tab which shows table foreign keys which refer to your table in an Entity Relationship Diagram format.

How do I get the full path to a Perl script that is executing?

None of the "top" answers were right for me. The problem with using FindBin '$Bin' or Cwd is that they return absolute path with all symbolic links resolved. In my case I needed the exact path with symbolic links present - the same as returns Unix command "pwd" and not "pwd -P". The following function provides the solution:

sub get_script_full_path {
    use File::Basename;
    use File::Spec;
    use Cwd qw(chdir cwd);
    my $curr_dir = cwd();
    chdir(dirname($0));
    my $dir = $ENV{PWD};
    chdir( $curr_dir);
    return File::Spec->catfile($dir, basename($0));
}

What is the string length of a GUID?

The correct thing to do here is to store it as uniqueidentifier - this is then fully indexable, etc. at the database. The next-best option would be a binary(16) column: standard GUIDs are exactly 16 bytes in length.

If you must store it as a string, the length really comes down to how you choose to encode it. As hex (AKA base-16 encoding) without hyphens it would be 32 characters (two hex digits per byte), so char(32).

However, you might want to store the hyphens. If you are short on space, but your database doesn't support blobs / guids natively, you could use Base64 encoding and remove the == padding suffix; that gives you 22 characters, so char(22). There is no need to use Unicode, and no need for variable-length - so nvarchar(max) would be a bad choice, for example.

unbound method f() must be called with fibo_ instance as first argument (got classobj instance instead)

import swineflu

x = swineflu.fibo()   # create an object `x` of class `fibo`, an instance of the class
x.f()                 # call the method `f()`, bound to `x`. 

Here is a good tutorial to get started with classes in Python.

How to search for a file in the CentOS command line

CentOS is Linux, so as in just about all other Unix/Linux systems, you have the find command. To search for files within the current directory:

find -name "filename"

You can also have wildcards inside the quotes, and not just a strict filename. You can also explicitly specify a directory to start searching from as the first argument to find:

find / -name "filename"

will look for "filename" or all the files that match the regex expression in between the quotes, starting from the root directory. You can also use single quotes instead of double quotes, but in most cases you don't need either one, so the above commands will work without any quotes as well. Also, for example, if you're searching for java files and you know they are somewhere in your /home/username, do:

find /home/username -name *.java

There are many more options to the find command and you should do a:

man find

to learn more about it.

One more thing: if you start searching from / and are not root or are not sudo running the command, you might get warnings that you don't have permission to read certain directories. To ignore/remove those, do:

find / -name 'filename' 2>/dev/null

That just redirects the stderr to /dev/null.

What's the easiest way to escape HTML in Python?

cgi.escape should be good to escape HTML in the limited sense of escaping the HTML tags and character entities.

But you might have to also consider encoding issues: if the HTML you want to quote has non-ASCII characters in a particular encoding, then you would also have to take care that you represent those sensibly when quoting. Perhaps you could convert them to entities. Otherwise you should ensure that the correct encoding translations are done between the "source" HTML and the page it's embedded in, to avoid corrupting the non-ASCII characters.

Catching an exception while using a Python 'with' statement

The best "Pythonic" way to do this, exploiting the with statement, is listed as Example #6 in PEP 343, which gives the background of the statement.

@contextmanager
def opened_w_error(filename, mode="r"):
    try:
        f = open(filename, mode)
    except IOError, err:
        yield None, err
    else:
        try:
            yield f, None
        finally:
            f.close()

Used as follows:

with opened_w_error("/etc/passwd", "a") as (f, err):
    if err:
        print "IOError:", err
    else:
        f.write("guido::0:0::/:/bin/sh\n")

Best way to list files in Java, sorted by Date Modified?

What's about similar approach, but without boxing to the Long objects:

File[] files = directory.listFiles();

Arrays.sort(files, new Comparator<File>() {
    public int compare(File f1, File f2) {
        return Long.compare(f1.lastModified(), f2.lastModified());
    }
});

Android Lint contentDescription warning

Since it is only a warning you can suppress it. Go to your XML's Graphical Layout and do this:

  1. Click on the right top corner red button

    enter image description here

  2. Select "Disable Issue Type" (for example)

    enter image description here

How to quickly edit values in table in SQL Server Management Studio?

Brendan is correct. You can edit the Select command to edit a filtered list of records. For instance "WHERE dept_no = 200".

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

<link rel="apple-touch-icon" sizes="114x114" href="${resource(dir: 'images', file: 
'apple-touch-icon-retina.png')}">

or you can use this one

<link rel="shortcut icon" sizes="114x114" href="${resource(dir: 'images', file: 'favicon.ico')}"
type="image/x-icon">

Combine two data frames by rows (rbind) when they have different sets of columns

I wrote a function to do this because I like my code to tell me if something is wrong. This function will explicitly tell you which column names don't match and if you have a type mismatch. Then it will do its best to combine the data.frames anyway. The limitation is that you can only combine two data.frames at a time.

### combines data frames (like rbind) but by matching column names
# columns without matches in the other data frame are still combined
# but with NA in the rows corresponding to the data frame without
# the variable
# A warning is issued if there is a type mismatch between columns of
# the same name and an attempt is made to combine the columns
combineByName <- function(A,B) {
    a.names <- names(A)
    b.names <- names(B)
    all.names <- union(a.names,b.names)
    print(paste("Number of columns:",length(all.names)))
    a.type <- NULL
    for (i in 1:ncol(A)) {
        a.type[i] <- typeof(A[,i])
    }
    b.type <- NULL
    for (i in 1:ncol(B)) {
        b.type[i] <- typeof(B[,i])
    }
    a_b.names <- names(A)[!names(A)%in%names(B)]
    b_a.names <- names(B)[!names(B)%in%names(A)]
    if (length(a_b.names)>0 | length(b_a.names)>0){
        print("Columns in data frame A but not in data frame B:")
        print(a_b.names)
        print("Columns in data frame B but not in data frame A:")
        print(b_a.names)
    } else if(a.names==b.names & a.type==b.type){
        C <- rbind(A,B)
        return(C)
    }
    C <- list()
    for(i in 1:length(all.names)) {
        l.a <- all.names[i]%in%a.names
        pos.a <- match(all.names[i],a.names)
        typ.a <- a.type[pos.a]
        l.b <- all.names[i]%in%b.names
        pos.b <- match(all.names[i],b.names)
        typ.b <- b.type[pos.b]
        if(l.a & l.b) {
            if(typ.a==typ.b) {
                vec <- c(A[,pos.a],B[,pos.b])
            } else {
                warning(c("Type mismatch in variable named: ",all.names[i],"\n"))
                vec <- try(c(A[,pos.a],B[,pos.b]))
            }
        } else if (l.a) {
            vec <- c(A[,pos.a],rep(NA,nrow(B)))
        } else {
            vec <- c(rep(NA,nrow(A)),B[,pos.b])
        }
        C[[i]] <- vec
    }
    names(C) <- all.names
    C <- as.data.frame(C)
    return(C)
}

adding and removing classes in angularJs using ng-click

for Reactive forms -

HTML file

_x000D_
_x000D_
<div class="col-sm-2">_x000D_
  <button type="button"  [class]= "btn_class"  id="b1" (click)="changeMe()">{{ btn_label }}</button>_x000D_
</div>
_x000D_
_x000D_
_x000D_

TS file

_x000D_
_x000D_
changeMe() {_x000D_
  switch (this.btn_label) {_x000D_
    case 'Yes ': this.btn_label = 'Custom' ;_x000D_
    this.btn_class = 'btn btn-danger btn-lg btn-block';_x000D_
    break;_x000D_
    case 'Custom': this.btn_label = ' No ' ;_x000D_
    this.btn_class = 'btn btn-success btn-lg btn-block';_x000D_
    break;_x000D_
    case ' No ': this.btn_label = 'Yes ';_x000D_
      this.btn_class = 'btn btn-primary btn-lg btn-block';_x000D_
      break;_x000D_
  }
_x000D_
_x000D_
_x000D_

How to read a text file?

It depends on what you are trying to do.

file, err := os.Open("file.txt")
fmt.print(file)

The reason it outputs &{0xc082016240}, is because you are printing the pointer value of a file-descriptor (*os.File), not file-content. To obtain file-content, you may READ from a file-descriptor.


To read all file content(in bytes) to memory, ioutil.ReadAll

package main

import (
    "fmt"
    "io/ioutil"
    "os"
    "log"
)

func main() {
    file, err := os.Open("file.txt")
    if err != nil {
        log.Fatal(err)
    }
    defer func() {
        if err = f.Close(); err != nil {
            log.Fatal(err)
        }
    }()


  b, err := ioutil.ReadAll(file)
  fmt.Print(b)
}

But sometimes, if the file size is big, it might be more memory-efficient to just read in chunks: buffer-size, hence you could use the implementation of io.Reader.Read from *os.File

func main() {
    file, err := os.Open("file.txt")
    if err != nil {
        log.Fatal(err)
    }
    defer func() {
        if err = f.Close(); err != nil {
            log.Fatal(err)
        }
    }()


    buf := make([]byte, 32*1024) // define your buffer size here.

    for {
        n, err := file.Read(buf)

        if n > 0 {
            fmt.Print(buf[:n]) // your read buffer.
        }

        if err == io.EOF {
            break
        }
        if err != nil {
            log.Printf("read %d bytes: %v", n, err)
            break
        }
    }

}

Otherwise, you could also use the standard util package: bufio, try Scanner. A Scanner reads your file in tokens: separator.

By default, scanner advances the token by newline (of course you can customise how scanner should tokenise your file, learn from here the bufio test).

package main

import (
    "fmt"
    "os"
    "log"
    "bufio"
)

func main() {
    file, err := os.Open("file.txt")
    if err != nil {
        log.Fatal(err)
    }
    defer func() {
        if err = f.Close(); err != nil {
            log.Fatal(err)
        }
    }()

    scanner := bufio.NewScanner(file)

    for scanner.Scan() {             // internally, it advances token based on sperator
        fmt.Println(scanner.Text())  // token in unicode-char
        fmt.Println(scanner.Bytes()) // token in bytes

    }
}

Lastly, I would also like to reference you to this awesome site: go-lang file cheatsheet. It encompassed pretty much everything related to working with files in go-lang, hope you'll find it useful.

How do you reinstall an app's dependencies using npm?

The easiest way that I can see is delete node_modules folder and execute npm install.

How to close Browser Tab After Submitting a Form?

If you have to use the same page as the action, you cannot use onSubmit="window.close();" as it will close the window before the response is received. You have to dinamycally output a JS snippet that closes the window after the SQL data is processed. It would however be far more elegant to use another page as the form action.

Installing a specific version of angular with angular cli

If you still have problems and are using nvm make sure to set the nvm node environment.

To select the latest version installed. To see versions use nvm list.

nvm use node
sudo npm remove -g @angular/cli
sudo npm install -g @angular/cli

Or to install a specific version use:

sudo npm install -g @angular/[email protected]

If you dir permission errors use:

sudo npm install -g @angular/[email protected] --unsafe-perm

How to do a join in linq to sql with method syntax?

Justin has correctly shown the expansion in the case where the join is just followed by a select. If you've got something else, it becomes more tricky due to transparent identifiers - the mechanism the C# compiler uses to propagate the scope of both halves of the join.

So to change Justin's example slightly:

var result = from sc in enumerableOfSomeClass
             join soc in enumerableOfSomeOtherClass
             on sc.Property1 equals soc.Property2
             where sc.X + sc.Y == 10
             select new { SomeClass = sc, SomeOtherClass = soc }

would be converted into something like this:

var result = enumerableOfSomeClass
    .Join(enumerableOfSomeOtherClass,
          sc => sc.Property1,
          soc => soc.Property2,
          (sc, soc) => new { sc, soc })
    .Where(z => z.sc.X + z.sc.Y == 10)
    .Select(z => new { SomeClass = z.sc, SomeOtherClass = z.soc });

The z here is the transparent identifier - but because it's transparent, you can't see it in the original query :)

Create line after text with css

This is the most easy way I found to achieve the result: Just use hr tag before the text, and set the margin top for text. Very short and easy to understand! jsfiddle

_x000D_
_x000D_
h2 {_x000D_
  background-color: #ffffff;_x000D_
  margin-top: -22px;_x000D_
  width: 25%;_x000D_
}_x000D_
_x000D_
hr {_x000D_
  border: 1px solid #e9a216;_x000D_
}
_x000D_
<br>_x000D_
_x000D_
<hr>_x000D_
<h2>ABOUT US</h2>
_x000D_
_x000D_
_x000D_

Difference between frontend, backend, and middleware in web development

There are in fact 3 questions in your question :

  • Define frontend, middle and back end
  • How and when do they overlap ?
  • Their associated usual bottlenecks.

What JB King has described is correct, but it is a particular, simple version, where in fact he mapped front, middle and bacn to an MVC layer. He mapped M to the back, V to the front, and C to the middle.

For many people, it is just fine, since they come from the ugly world where even MVC was not applied, and you could have direct DB calls in a view.

However in real, complex web applications, you indeed have two or three different layers, called front, middle and back. Each of them may have an associated database and a controller.

The front-end will be visible by the end-user. It should not be confused with the front-office, which is the UI for parameters and administration of the front. The front-end will usually be some kind of CMS or e-commerce Platform (Magento, etc.)

The middle-end is not compulsory and is where the business logics is. It will be based on a PIM, a MDM tool, or some kind of custom database where you enrich your produts or your articles (for CMS). It'll also be the place where you code business functions that need to be shared between differents frontends (for instance between the PC frontend and the API-based mobile application). Sometimes, an ESB or tool like ActiveMQ will be your middle-end

The back-end will be a 3rd layer, surrouding your source database or your ERP. It may be jsut the API wrting to and reading from your ERP. It may be your supplier DB, if you are doing e-commerce. In fact, it really depends on web projects, but it is always a central repository. It'll be accessed either through a DB call, through an API, or an Hibernate layer, or a full-featured back-end application

This description means that answering the other 2 questions is not possible in this thread, as bottlenecks really depend on what your 3 ends contain : what JB King wrote remains true for simple MVC architectures

at the time the question was asked (5 years ago), maybe the MVC pattern was not yet so widely adopted. Now, there is absolutely no reason why the MVC pattern would not be followed and a view would be tied to DB calls. If you read the question "Are there cases where they MUST overlap, and frontend/backend cannot be separated?" in a broader sense, with 3 different components, then there times when the 3 layers architecture is useless of course. Think of a simple personal blog, you'll not need to pull external data or poll RabbitMQ queues.

Android fastboot waiting for devices

Just use sudo, fast boot needs Root Permission

Lazy Loading vs Eager Loading

// Using LINQ and just referencing p.Employer will lazy load
// I am not at a computer but I know I have lazy loaded in one
// query with a single query call like below.
List<Person> persons = new List<Person>();
using(MyDbContext dbContext = new MyDbContext())
{
    persons = (
        from p in dbcontext.Persons
        select new Person{
            Name = p.Name,
            Email = p.Email,
            Employer = p.Employer
        }).ToList();
}

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

This post shows an example of a directive that delays the model changes to an input until the blur event fires.

Here is a fiddle that shows the ng-change working with the new ng-model-on-blur directive. Note this is a slight tweak to the original fiddle.

If you add the directive to your code you would change your binding to this:

<input type="text" ng-model="name" ng-model-onblur ng-change="update()" />

Here is the directive:

// override the default input to update on blur
angular.module('app', []).directive('ngModelOnblur', function() {
    return {
        restrict: 'A',
        require: 'ngModel',
        priority: 1, // needed for angular 1.2.x
        link: function(scope, elm, attr, ngModelCtrl) {
            if (attr.type === 'radio' || attr.type === 'checkbox') return;

            elm.unbind('input').unbind('keydown').unbind('change');
            elm.bind('blur', function() {
                scope.$apply(function() {
                    ngModelCtrl.$setViewValue(elm.val());
                });         
            });
        }
    };
});

Note: as @wjin mentions in the comments below this feature is supported directly in Angular 1.3 (currently in beta) via ngModelOptions. See the docs for more info.

How do I resolve "Run-time error '429': ActiveX component can't create object"?

I got the same error but I solved by using regsvr32.exe in C:\Windows\SysWOW64. Because we use x64 system. So if your machine is also x64, the ocx/dll must registered also with regsvr32 x64 version

How to use Oracle ORDER BY and ROWNUM correctly?

An alternate I would suggest in this use case is to use the MAX(t_stamp) to get the latest row ... e.g.

select t.* from raceway_input_labo t
where t.t_stamp = (select max(t_stamp) from raceway_input_labo) 
limit 1

My coding pattern preference (perhaps) - reliable, generally performs at or better than trying to select the 1st row from a sorted list - also the intent is more explicitly readable.
Hope this helps ...

SQLer

How to return history of validation loss in Keras

Actually, you can also do it with the iteration method. Because sometimes we might need to use the iteration method instead of the built-in epochs method to visualize the training results after each iteration.

history = [] #Creating a empty list for holding the loss later
for iteration in range(1, 3):
    print()
    print('-' * 50)
    print('Iteration', iteration)
    result = model.fit(X, y, batch_size=128, nb_epoch=1) #Obtaining the loss after each training
    history.append(result.history['loss']) #Now append the loss after the training to the list.
    start_index = random.randint(0, len(text) - maxlen - 1)
print(history)

This way allows you to get the loss you want while maintaining your iteration method.

Executing Javascript code "on the spot" in Chrome?

I'm not sure how far it will get you, but you can execute JavaScript one line at a time from the Developer Tool Console.

Inserting data to table (mysqli insert)

Okay, of course the question has been answered, but no-one seems to notice the third line of your code. It continuosly bugged me.

    <?php
    mysqli_connect("localhost","root","","web_table");
    mysql_select_db("web_table") or die(mysql_error());

for some reason, you made a mysqli connection to server, but you are trying to make a mysql connection to database.To get going, rather use

       $link = mysqli_connect("localhost","root","","web_table");
       mysqli_select_db ($link , "web_table" ) or die.....

or for where i began

     <?php $connection = mysqli_connect("localhost","root","","web_table");       
      global $connection; // global connection to databases - kill it once you're done

or just query with a $connection parameter as the other argument like above. Get rid of that third line.

Is there a way to cache GitHub credentials for pushing commits?

It wasn't immediately obvious to me that I needed to download the helper first! I found the credential.helper download at Atlassian's Permanently authenticating with Git repositories.

Quote:

Follow these steps if you want to use Git with credential caching on OS X:

Download the binary git-credential-osxkeychain.

Run the command below to ensure the binary is executable:

chmod a+x git-credential-osxkeychain

Put it in the directory /usr/local/bin.

Run the command below:

git config --global credential.helper osxkeychain

Using AngularJS date filter with UTC date

If you do use moment.js you would use the moment().utc() function to convert a moment object to UTC. You can also handle a nice format inside the controller instead of the view by using the moment().format() function. For example:

moment(myDate).utc().format('MM/DD/YYYY')

Kill all processes for a given user

On Debian LINUX, I use: ps -o pid= -u username | xargs sudo kill -9.

With -o pid= the ps header is supressed, and the output is only the pid list. As far as I know, Debian shell is POSIX compliant.

How to define relative paths in Visual Studio Project?

I have used a syntax like this before:

$(ProjectDir)..\headers

or

..\headers

As other have pointed out, the starting directory is the one your project file is in(vcproj or vcxproj), not where your main code is located.

What is the difference between a token and a lexeme?

Token: Token is a sequence of characters that can be treated as a single logical entity. Typical tokens are,
1) Identifiers
2) keywords
3) operators
4) special symbols
5)constants

Pattern: A set of strings in the input for which the same token is produced as output. This set of strings is described by a rule called a pattern associated with the token.
Lexeme: A lexeme is a sequence of characters in the source program that is matched by the pattern for a token.

Remove last characters from a string in C#. An elegant way?

Use:

public static class StringExtensions
{
    /// <summary>
    /// Cut End. "12".SubstringFromEnd(1) -> "1"
    /// </summary>
    public static string SubstringFromEnd(this string value, int startindex)
    {
        if (string.IsNullOrEmpty(value)) return value;
        return value.Substring(0, value.Length - startindex);
    }
}

I prefer an extension method here for two reasons:

  1. I can chain it with Substring. Example: f1.Substring(directorypathLength).SubstringFromEnd(1)
  2. Speed.

ps1 cannot be loaded because running scripts is disabled on this system

If you are using visual studio code:

  1. Open terminal
  2. Run the command: Set-ExecutionPolicy -Scope CurrentUser -ExecutionPolicy Unrestricted
  3. Then run the command protractor conf.js

This is related to protractor test script execution related and I faced the same issue and it was resolved like this.

When should I create a destructor?

When you have unmanaged resources and you need to make sure they will be cleaned up when your object goes away. Good example would be COM objects or File Handlers.

how to get the attribute value of an xml node using java

try something like this :

    DocumentBuilder builder = DocumentBuilderFactory.newInstance().newDocumentBuilder();
    Document dDoc = builder.parse("d://utf8test.xml");

    XPath xPath = XPathFactory.newInstance().newXPath();
    NodeList nodes = (NodeList) xPath.evaluate("//xml/ep/source/@type", dDoc, XPathConstants.NODESET);
    for (int i = 0; i < nodes.getLength(); i++) {
        Node node = nodes.item(i);
        System.out.println(node.getTextContent());
    }

please note the changes :

  • we ask for a nodeset (XPathConstants.NODESET) and not only for a single node.
  • the xpath is now //xml/ep/source/@type and not //xml/source/@type/text()

PS: can you add the tag java to your question ? thanks.

How to assign the output of a Bash command to a variable?

Try:

pwd=`pwd`

or

pwd=$(pwd)

Notice no spaces after the equals sign.

Also as Mr. Weiss points out; you don't assign to $pwd, you assign to pwd.

How to do a newline in output

Actually you don't even need the block:

  Dir.chdir 'C:/Users/name/Music'
  music = Dir['C:/Users/name/Music/*.{mp3, MP3}']
  puts 'what would you like to call the playlist?'
  playlist_name = gets.chomp + '.m3u'

  File.open(playlist_name, 'w').puts(music)

Accidentally committed .idea directory files into git

You should add a .gitignore file to your project and add /.idea to it. You should add each directory / file in one line.

If you have an existing .gitignore file then you should simply add a new line to the file and put /.idea to the new line.

After that run git rm -r --cached .idea command.

If you faced an error you can run git rm -r -f --cached .idea command. After all run git add . and then git commit -m "Removed .idea directory and added a .gitignore file" and finally push the changes by running git push command.

mysqli::query(): Couldn't fetch mysqli

I had the same problem. I changed the localhost parameter in the mysqli object to '127.0.0.1' instead of writing 'localhost'. It worked; I’m not sure how or why.

$db_connection = new mysqli("127.0.0.1","root","","db_name");

Hope it helps.

Pandas: create two new columns in a dataframe with values calculated from a pre-existing column

I'd just use zip:

In [1]: from pandas import *

In [2]: def calculate(x):
   ...:     return x*2, x*3
   ...: 

In [3]: df = DataFrame({'a': [1,2,3], 'b': [2,3,4]})

In [4]: df
Out[4]: 
   a  b
0  1  2
1  2  3
2  3  4

In [5]: df["A1"], df["A2"] = zip(*df["a"].map(calculate))

In [6]: df
Out[6]: 
   a  b  A1  A2
0  1  2   2   3
1  2  3   4   6
2  3  4   6   9

how to send multiple data with $.ajax() jquery

  var value1=$("id1").val();
  var value2=$("id2").val();
    data:"{'data1':'"+value1+"','data2':'"+value2+"'}"

You can use this way to pass data

Android add placeholder text to EditText

In your Activity

<EditText
                android:layout_width="fill_parent"
                android:layout_height="wrap_content"
                android:layout_marginBottom="10dp"
                android:background="@null"
                android:hint="Text Example"
                android:padding="5dp"
                android:singleLine="true"
                android:id="@+id/name"
                android:textColor="@color/magenta"/>

enter image description here

Meaning of numbers in "col-md-4"," col-xs-1", "col-lg-2" in Bootstrap

Here you go

col-lg-2 : if the screen is large (lg) then this component will take space of 2 elements considering entire row can fit 12 elements ( so you will see that on large screen this component takes 16% space of a row)

col-lg-6 : if the screen is large (lg) then this component will take space of 6 elements considering entire row can fit 12 elements -- when applied you will see that the component has taken half the available space in the row.

Above rule is only applied when the screen is large. when the screen is small this rule is discarded and only one component per row is shown.

Below image shows various screen size widths :

screen size definitions

How do you get a query string on Flask?

Every form of the query string retrievable from flask request object as described in O'Reilly Flask Web Devleopment:

From O'Reilly Flask Web Development, and as stated by Manan Gouhari earlier, first you need to import request:

from flask import request

request is an object exposed by Flask as a context variable named (you guessed it) request. As its name suggests, it contains all the information that the client included in the HTTP request. This object has many attributes and methods that you can retrieve and call, respectively.

You have quite a few request attributes which contain the query string from which to choose. Here I will list every attribute that contains in any way the query string, as well as a description from the O'Reilly book of that attribute.

First there is args which is "a dictionary with all the arguments passed in the query string of the URL." So if you want the query string parsed into a dictionary, you'd do something like this:

from flask import request

@app.route('/'):
    queryStringDict = request.args

(As others have pointed out, you can also use .get('<arg_name>') to get a specific value from the dictionary)

Then, there is the form attribute, which does not contain the query string, but which is included in part of another attribute that does include the query string which I will list momentarily. First, though, form is "A dictionary with all the form fields submitted with the request." I say that to say this: there is another dictionary attribute available in the flask request object called values. values is "A dictionary that combines the values in form and args." Retrieving that would look something like this:

from flask import request

@app.route('/'):
    formFieldsAndQueryStringDict = request.values

(Again, use .get('<arg_name>') to get a specific item out of the dictionary)

Another option is query_string which is "The query string portion of the URL, as a raw binary value." Example of that:

from flask import request

@app.route('/'):
    queryStringRaw = request.query_string

Then as an added bonus there is full_path which is "The path and query string portions of the URL." Por ejemplo:

from flask import request

@app.route('/'):
    pathWithQueryString = request.full_path

And finally, url, "The complete URL requested by the client" (which includes the query string):

from flask import request

@app.route('/'):
    pathWithQueryString = request.url

Happy hacking :)

Difference between Spring MVC and Spring Boot

  • Spring MVC is a complete HTTP oriented MVC framework managed by the Spring Framework and based in Servlets. It would be equivalent to JSF in the JavaEE stack. The most popular elements in it are classes annotated with @Controller, where you implement methods you can access using different HTTP requests. It has an equivalent @RestController to implement REST-based APIs.
  • Spring boot is a utility for setting up applications quickly, offering an out of the box configuration in order to build Spring-powered applications. As you may know, Spring integrates a wide range of different modules under its umbrella, as spring-core, spring-data, spring-web (which includes Spring MVC, by the way) and so on. With this tool you can tell Spring how many of them to use and you'll get a fast setup for them (you are allowed to change it by yourself later on).

So, Spring MVC is a framework to be used in web applications and Spring Boot is a Spring based production-ready project initializer. You might find useful visiting the Spring MVC tag wiki as well as the Spring Boot tag wiki in SO.

Simple regular expression for a decimal with a precision of 2

Main answer is WRONG because it valids 5. or 5, inputs

this code handle it (but in my example negative numbers are forbidden):

/^[0-9]+([.,][0-9]{1,2})?$/;

results are bellow:

true => "0" / true => "0.00" / true => "0.0" / true => "0,00" / true => "0,0" / true => "1,2" true => "1.1"/ true => "1" / true => "100" true => "100.00"/ true => "100.0" / true => "1.11" / true => "1,11"/ false => "-5" / false => "-0.00" / true => "101" / false => "0.00.0" / true => "0.000" / true => "000.25" / false => ".25" / true => "100.01" / true => "100.2" / true => "00" / false => "5." / false => "6," / true => "82" / true => "81,3" / true => "7" / true => "7.654"

How to redirect the output of print to a TXT file

A slightly hackier way (that is different than the answers above, which are all valid) would be to just direct the output into a file via console.

So imagine you had main.py

if True:
    print "hello world"
else:
    print "goodbye world"

You can do

python main.py >> text.log

and then text.log will get all of the output.

This is handy if you already have a bunch of print statements and don't want to individually change them to print to a specific file. Just do it at the upper level and direct all prints to a file (only drawback is that you can only print to a single destination).

List directory in Go

Starting with Go 1.16, you can use the os.ReadDir function.

func ReadDir(name string) ([]DirEntry, error)

It reads a given directory and returns a DirEntry slice that contains the directory entries sorted by filename.

It's an optimistic function, so that, when an error occurs while reading the directory entries, it tries to return you a slice with the filenames up to the point before the error.

package main

import (
    "fmt"
    "log"
    "os"
)

func main() {
    files, err := os.ReadDir(".")
    if err != nil {
        log.Fatal(err)
    }

    for _, file := range files {
        fmt.Println(file.Name())
    }
}

Background

Go 1.16 (Q1 2021) will propose, with CL 243908 and CL 243914 , the ReadDir function, based on the FS interface:

// An FS provides access to a hierarchical file system.
//
// The FS interface is the minimum implementation required of the file system.
// A file system may implement additional interfaces,
// such as fsutil.ReadFileFS, to provide additional or optimized functionality.
// See io/fsutil for details.
type FS interface {
    // Open opens the named file.
    //
    // When Open returns an error, it should be of type *PathError
    // with the Op field set to "open", the Path field set to name,
    // and the Err field describing the problem.
    //
    // Open should reject attempts to open names that do not satisfy
    // ValidPath(name), returning a *PathError with Err set to
    // ErrInvalid or ErrNotExist.
    Open(name string) (File, error)
}

That allows for "os: add ReadDir method for lightweight directory reading":
See commit a4ede9f:

// ReadDir reads the contents of the directory associated with the file f
// and returns a slice of DirEntry values in directory order.
// Subsequent calls on the same file will yield later DirEntry records in the directory.
//
// If n > 0, ReadDir returns at most n DirEntry records.
// In this case, if ReadDir returns an empty slice, it will return an error explaining why.
// At the end of a directory, the error is io.EOF.
//
// If n <= 0, ReadDir returns all the DirEntry records remaining in the directory.
// When it succeeds, it returns a nil error (not io.EOF).
func (f *File) ReadDir(n int) ([]DirEntry, error) 

// A DirEntry is an entry read from a directory (using the ReadDir method).
type DirEntry interface {
    // Name returns the name of the file (or subdirectory) described by the entry.
    // This name is only the final element of the path, not the entire path.
    // For example, Name would return "hello.go" not "/home/gopher/hello.go".
    Name() string
    
    // IsDir reports whether the entry describes a subdirectory.
    IsDir() bool
    
    // Type returns the type bits for the entry.
    // The type bits are a subset of the usual FileMode bits, those returned by the FileMode.Type method.
    Type() os.FileMode
    
    // Info returns the FileInfo for the file or subdirectory described by the entry.
    // The returned FileInfo may be from the time of the original directory read
    // or from the time of the call to Info. If the file has been removed or renamed
    // since the directory read, Info may return an error satisfying errors.Is(err, ErrNotExist).
    // If the entry denotes a symbolic link, Info reports the information about the link itself,
    // not the link's target.
    Info() (FileInfo, error)
}

src/os/os_test.go#testReadDir() illustrates its usage:

    file, err := Open(dir)
    if err != nil {
        t.Fatalf("open %q failed: %v", dir, err)
    }
    defer file.Close()
    s, err2 := file.ReadDir(-1)
    if err2 != nil {
        t.Fatalf("ReadDir %q failed: %v", dir, err2)
    }

Ben Hoyt points out in the comments to Go 1.16 os.ReadDir:

os.ReadDir(path string) ([]os.DirEntry, error), which you'll be able to call directly without the Open dance.
So you can probably shorten this to just os.ReadDir, as that's the concrete function most people will call.

See commit 3d913a9 (Dec. 2020):

os: add ReadFile, WriteFile, CreateTemp (was TempFile), MkdirTemp (was TempDir) from io/ioutil

io/ioutil was a poorly defined collection of helpers.

Proposal #40025 moved out the generic I/O helpers to io. This CL for proposal #42026 moves the OS-specific helpers to os, making the entire io/ioutil package deprecated.

os.ReadDir returns []DirEntry, in contrast to ioutil.ReadDir's []FileInfo.
(Providing a helper that returns []DirEntry is one of the primary motivations for this change.)

ERROR Could not load file or assembly 'AjaxControlToolkit' or one of its dependencies

If you are working with Source safe then make a new directory and take the latest there, this solved my issue...thanks

SQL search multiple values in same field

Yes, you can use SQL IN operator to search multiple absolute values:

SELECT name FROM products WHERE name IN ( 'Value1', 'Value2', ... );

If you want to use LIKE you will need to use OR instead:

SELECT name FROM products WHERE name LIKE '%Value1' OR name LIKE '%Value2';

Using AND (as you tried) requires ALL conditions to be true, using OR requires at least one to be true.

How to clear a notification in Android

    // Get a notification builder that's compatible with platform versions
    // >= 4
    NotificationCompat.Builder builder = new NotificationCompat.Builder(
            this);
    builder.setSound(soundUri);
    builder.setAutoCancel(true);

this works if you are using a notification builder...

How to assign a heredoc value to a variable in Bash?

Thanks to dimo414's answer, this shows how his great solution works, and shows that you can have quotes and variables in the text easily as well:

example output

$ ./test.sh

The text from the example function is:
  Welcome dev: Would you "like" to know how many 'files' there are in /tmp?

  There are "      38" files in /tmp, according to the "wc" command

test.sh

#!/bin/bash

function text1()
{
  COUNT=$(\ls /tmp | wc -l)
cat <<EOF

  $1 Would you "like" to know how many 'files' there are in /tmp?

  There are "$COUNT" files in /tmp, according to the "wc" command

EOF
}

function main()
{
  OUT=$(text1 "Welcome dev:")
  echo "The text from the example function is: $OUT"
}

main

Missing Maven dependencies in Eclipse project

In Eclipse STS if "Maven Dependencies" disappears it, you have to check and fix your pom.xml. I did this (twice) and I resolved it. It was not a dependencies issue but a String generated and moved in a position random in my pom.xml.

WPF ListView turn off selection

Use the code below:

<ListView.ItemContainerStyle>
    <Style TargetType="{x:Type ListViewItem}">
        <Setter Property="Background" Value="Transparent" />
        <Setter Property="Template">
            <Setter.Value>
                <ControlTemplate TargetType="{x:Type ListViewItem}">
                    <ContentPresenter />
                </ControlTemplate>
            </Setter.Value>
        </Setter>
    </Style>
</ListView.ItemContainerStyle>

What is the (function() { } )() construct in JavaScript?

One more use case is memoization where a cache object is not global:

var calculate = (function() {
  var cache = {};
  return function(a) {

    if (cache[a]) {
      return cache[a];
    } else {
      // Calculate heavy operation
      cache[a] = heavyOperation(a);
      return cache[a];
    }
  }
})();

The R %in% operator

You can use all

> all(1:6 %in% 0:36)
[1] TRUE
> all(1:60 %in% 0:36)
[1] FALSE

On a similar note, if you want to check whether any of the elements is TRUE you can use any

> any(1:6 %in% 0:36)
[1] TRUE
> any(1:60 %in% 0:36)
[1] TRUE
> any(50:60 %in% 0:36)
[1] FALSE

Importing PNG files into Numpy?

I like the build-in pathlib libary because of quick options like directory= Path.cwd() Together with opencv it's quite easy to read pngs to numpy arrays. In this example you can even check the prefix of the image.

from pathlib import Path
import cv2
prefix = "p00"
suffix = ".png"
directory= Path.cwd()
file_names= [subp.name for subp in directory.rglob('*') if  (prefix in subp.name) & (suffix == subp.suffix)]
file_names.sort()
print(file_names)

all_frames= []
for file_name in file_names:
    file_path = str(directory / file_name)
    frame=cv2.imread(file_path)
    all_frames.append(frame)
print(type(all_frames[0]))
print(all_frames[0] [1][1])

Output:

['p000.png', 'p001.png', 'p002.png', 'p003.png', 'p004.png', 'p005.png', 'p006.png', 'p007.png', 'p008.png', 'p009.png']
<class 'numpy.ndarray'>
[255 255 255]

Deleting a file in VBA

The following can be used to test for the existence of a file, and then to delete it.

Dim aFile As String
aFile = "c:\file_to_delete.txt"
If Len(Dir$(aFile)) > 0 Then
     Kill aFile
End If 

Primary key or Unique index?

As long as you do not allow NULL for a value, they should be handled the same, but the value NULL is handled differently on databases(AFAIK MS-SQL do not allow more than one(1) NULL value, mySQL and Oracle allow this, if a column is UNIQUE) So you must define this column NOT NULL UNIQUE INDEX

Parse date string and change format

convert string to datetime object

from datetime import datetime
s = "2016-03-26T09:25:55.000Z"
f = "%Y-%m-%dT%H:%M:%S.%fZ"
out = datetime.strptime(s, f)
print(out)
output:
2016-03-26 09:25:55

exit application when click button - iOS

You can use exit method to quit an ios app :

exit(0);

You should say same alert message and ask him to quit

Another way is by using [[NSThread mainThread] exit]

However you should not do this way

According to Apple, your app should not terminate on its own. Since the user did not hit the Home button, any return to the Home screen gives the user the impression that your app crashed. This is confusing, non-standard behavior and should be avoided.

how to read a text file using scanner in Java?

If you give a Scanner object a String, it will read it in as data. That is, "a.txt" does not open up a file called "a.txt". It literally reads in the characters 'a', '.', 't' and so forth.

This is according to Core Java Volume I, section 3.7.3.

If I find a solution to reading the actual paths, I will return and update this answer. The solution this text offers is to use

Scanner in = new Scanner(Paths.get("myfile.txt"));

But I can't get this to work because Path isn't recognized as a variable by the compiler. Perhaps I'm missing an import statement.

How to add CORS request in header in Angular 5

A POST with httpClient in Angular 6 was also doing an OPTIONS request:

Headers General:

Request URL:https://hp-probook/perl-bin/muziek.pl/=/postData
Request Method:OPTIONS
Status Code:200 OK
Remote Address:127.0.0.1:443
Referrer Policy:no-referrer-when-downgrade

My Perl REST server implements the OPTIONS request with return code 200.

The next POST request Header:

Accept:*/*
Accept-Encoding:gzip, deflate, br
Accept-Language:nl-NL,nl;q=0.8,en-US;q=0.6,en;q=0.4
Access-Control-Request-Headers:content-type
Access-Control-Request-Method:POST
Connection:keep-alive
Host:hp-probook
Origin:http://localhost:4200
Referer:http://localhost:4200/
User-Agent:Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/59.0.3071.109 Safari/537.36

Notice Access-Control-Request-Headers:content-type.

So, my backend perl script uses the following headers:


 -"Access-Control-Allow-Origin" => '*',
 -"Access-Control-Allow-Methods" => 'GET,POST,PATCH,DELETE,PUT,OPTIONS',
 -"Access-Control-Allow-Headers" => 'Origin, Content-Type, X-Auth-Token, content-type',

With this setup the GET and POST worked for me!

Appending to list in Python dictionary

dates_dict[key] = dates_dict.get(key, []).append(date) sets dates_dict[key] to None as list.append returns None.

In [5]: l = [1,2,3]

In [6]: var = l.append(3)

In [7]: print var
None

You should use collections.defaultdict

import collections
dates_dict = collections.defaultdict(list)

Jquery, set value of td in a table?

You can try below code:

$("Your button id or class").live("click", function(){

    $('#detailInfo').html('set your value as you want');

});

Good Luck...

Uninstall mongoDB from ubuntu

sudo service mongod stop
sudo apt-get purge mongodb-org*
sudo rm -r /var/log/mongodb
sudo rm -r /var/lib/mongodb

this worked for me

Flutter: Setting the height of the AppBar

At the time of writing this, I was not aware of PreferredSize. Cinn's answer is better to achieve this.

You can create your own custom widget with a custom height:

import "package:flutter/material.dart";

class Page extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return new Column(children : <Widget>[new CustomAppBar("Custom App Bar"), new Container()],);
  }
}


class CustomAppBar extends StatelessWidget {

  final String title;
  final double barHeight = 50.0; // change this for different heights 

  CustomAppBar(this.title);

  @override
  Widget build(BuildContext context) {
    final double statusbarHeight = MediaQuery
        .of(context)
        .padding
        .top;

    return new Container(
      padding: new EdgeInsets.only(top: statusbarHeight),
      height: statusbarHeight + barHeight,
      child: new Center(
        child: new Text(
          title,
          style: new TextStyle(fontSize: 20.0, fontWeight: FontWeight.bold),
        ),
      ),
    );
  }
}

Check if a string contains a substring in SQL Server 2005, using a stored procedure

CHARINDEX() searches for a substring within a larger string, and returns the position of the match, or 0 if no match is found

if CHARINDEX('ME',@mainString) > 0
begin
    --do something
end

Edit or from daniels answer, if you're wanting to find a word (and not subcomponents of words), your CHARINDEX call would look like:

CHARINDEX(' ME ',' ' + REPLACE(REPLACE(@mainString,',',' '),'.',' ') + ' ')

(Add more recursive REPLACE() calls for any other punctuation that may occur)

How to list the files inside a JAR file?

Here's a method I wrote for a "run all JUnits under a package". You should be able to adapt it to your needs.

private static void findClassesInJar(List<String> classFiles, String path) throws IOException {
    final String[] parts = path.split("\\Q.jar\\\\E");
    if (parts.length == 2) {
        String jarFilename = parts[0] + ".jar";
        String relativePath = parts[1].replace(File.separatorChar, '/');
        JarFile jarFile = new JarFile(jarFilename);
        final Enumeration<JarEntry> entries = jarFile.entries();
        while (entries.hasMoreElements()) {
            final JarEntry entry = entries.nextElement();
            final String entryName = entry.getName();
            if (entryName.startsWith(relativePath)) {
                classFiles.add(entryName.replace('/', File.separatorChar));
            }
        }
    }
}

Edit: Ah, in that case, you might want this snippet as well (same use case :) )

private static File findClassesDir(Class<?> clazz) {
    try {
        String path = clazz.getProtectionDomain().getCodeSource().getLocation().getFile();
        final String codeSourcePath = URLDecoder.decode(path, "UTF-8");
        final String thisClassPath = new File(codeSourcePath, clazz.getPackage().getName().repalce('.', File.separatorChar));
    } catch (UnsupportedEncodingException e) {
        throw new AssertionError("impossible", e);
    }
}

How to extract the hostname portion of a URL in JavaScript

Check this:

alert(window.location.hostname);

this will return host name as www.domain.com

and:

window.location.host

will return domain name with port like www.example.com:80

For complete reference check Mozilla developer site.

How to sum a variable by group

Several years later, just to add another simple base R solution that isn't present here for some reason- xtabs

xtabs(Frequency ~ Category, df)
# Category
# First Second  Third 
#    30      5     34 

Or if you want a data.frame back

as.data.frame(xtabs(Frequency ~ Category, df))
#   Category Freq
# 1    First   30
# 2   Second    5
# 3    Third   34

How to calculate time difference in java?

String start = "12:00:00";
String end = "02:05:00";

SimpleDateFormat format = new SimpleDateFormat("HH:mm:ss"); 

Date date1 = format.parse(start);

Date date2 = format.parse(end);

long difference = date2.getTime() - date1.getTime(); 

int minutes = (int) TimeUnit.MILLISECONDS.toMinutes(difference);

if(minutes<0)minutes += 1440; 

Now minutes will be the correct duration between two time (in minute).

How to get first and last day of week in Oracle?

SQL> var P_YEARWEEK varchar2(6)
SQL> exec :P_YEARWEEK := '201118'

PL/SQL procedure successfully completed.

SQL> with t as
  2  ( select substr(:P_YEARWEEK,1,4) year
  3         , substr(:P_YEARWEEK,5,2) week
  4      from dual
  5  )
  6  select year
  7       , week
  8       , trunc(to_date(year,'yyyy'),'yyyy')                              january_1
  9       , trunc(trunc(to_date(year,'yyyy'),'yyyy'),'iw')                  monday_week_1
 10       , trunc(trunc(to_date(year,'yyyy'),'yyyy'),'iw') + (week - 1) * 7 start_of_the_week
 11       , trunc(trunc(to_date(year,'yyyy'),'yyyy'),'iw') + week  * 7 - 1  end_of_the_week
 12    from t
 13  /

YEAR WE JANUARY_1           MONDAY_WEEK_1       START_OF_THE_WEEK   END_OF_THE_WEEK
---- -- ------------------- ------------------- ------------------- -------------------
2011 18 01-01-2011 00:00:00 27-12-2010 00:00:00 25-04-2011 00:00:00 01-05-2011 00:00:00

1 row selected.

Regards,
Rob.

Why am I getting ImportError: No module named pip ' right after installing pip?

What solved the issue on my case was go to:

cd C:\Program Files\Python37\Scripts

And run below command:

easy_install.exe pip

Creating a new DOM element from an HTML string using built-in DOM methods or Prototype

No need for any tweak, you got a native API:

const toNodes = html =>
    new DOMParser().parseFromString(html, 'text/html').body.childNodes[0]

What is stability in sorting algorithms and why is it important?

I know there are many answers for this, but to me, this answer, by Robert Harvey, summarized it much more clearly:

A stable sort is one which preserves the original order of the input set, where the [unstable] algorithm does not distinguish between two or more items.

Source

PHP array printing using a loop

Foreach before foreach: :)

reset($array); 
while(list($key,$value) = each($array))
{
  // we used this back in php3 :)
}

What is the difference between fastcgi and fpm?

FPM is a process manager to manage the FastCGI SAPI (Server API) in PHP.

Basically, it replaces the need for something like SpawnFCGI. It spawns the FastCGI children adaptively (meaning launching more if the current load requires it).

Otherwise, there's not much operating difference between it and FastCGI (The request pipeline from start of request to end is the same). It's just there to make implementing it easier.

ImportError: No module named 'google'

got this from cloud service documentation

pip install --upgrade google-cloud-translate

Worked for me !

How to generate different random numbers in a loop in C++?

Don't know men. I found the best way for me after testing different ways like 10 minutes. ( Change the numbers in code to get big or small random number.)

    int x;
srand ( time(NULL) );
x = rand() % 1000 * rand() % 10000 ;
cout<<x;

How can I change an element's class with JavaScript?

No offense, but it's unclever to change class on-the-fly as it forces the CSS interpreter to recalculate the visual presentation of the entire web page.

The reason is that it is nearly impossible for the CSS interpreter to know if any inheritance or cascading could be changed, so the short answer is:

Never ever change className on-the-fly !-)

But usually you'll only need to change a property or two, and that is easily implemented:

function highlight(elm){
    elm.style.backgroundColor ="#345";
    elm.style.color = "#fff";
}

jQuery Set Selected Option Using Next

$('your_select option:selected').next('option').prop('selected', true)

Append a tuple to a list - what's the difference between two ways?

It has nothing to do with append. tuple(3, 4) all by itself raises that error.

The reason is that, as the error message says, tuple expects an iterable argument. You can make a tuple of the contents of a single object by passing that single object to tuple. You can't make a tuple of two things by passing them as separate arguments.

Just do (3, 4) to make a tuple, as in your first example. There's no reason not to use that simple syntax for writing a tuple.

Python Write bytes to file

If you want to write bytes then you should open the file in binary mode.

f = open('/tmp/output', 'wb')

Excel Macro : How can I get the timestamp in "yyyy-MM-dd hh:mm:ss" format?

Timestamp in saving workbook path, the ":" needs to be changed. I used ":" -> "." which implies that I need to add the extension back "xlsx".

wb(x).SaveAs ThisWorkbook.Path & "\" & unique(x) & " - " & Format(Now(), "mm-dd-yy, hh.mm.ss") & ".xlsx"

CSS border less than 1px

A pixel is the smallest unit value to render something with, but you can trick thickness with optical illusions by modifying colors (the eye can only see up to a certain resolution too).

Here is a test to prove this point:

_x000D_
_x000D_
div { border-color: blue; border-style: solid; margin: 2px; }

div.b1 { border-width: 1px; }
div.b2 { border-width: 0.1em; }
div.b3 { border-width: 0.01em; }
div.b4 { border-width: 1px; border-color: rgb(160,160,255); }
_x000D_
<div class="b1">Some text</div>
<div class="b2">Some text</div>
<div class="b3">Some text</div>
<div class="b4">Some text</div>
_x000D_
_x000D_
_x000D_

Output

enter image description here

Which gives the illusion that the last DIV has a smaller border width, because the blue border blends more with the white background.


Edit: Alternate solution

Alpha values may also be used to simulate the same effect, without the need to calculate and manipulate RGB values.

_x000D_
_x000D_
.container {
  border-style: solid;
  border-width: 1px;
  
  margin-bottom: 10px;
}

.border-100 { border-color: rgba(0,0,255,1); }
.border-75 { border-color: rgba(0,0,255,0.75); }
.border-50 { border-color: rgba(0,0,255,0.5); }
.border-25 { border-color: rgba(0,0,255,0.25); }
_x000D_
<div class="container border-100">Container 1 (alpha = 1)</div>
<div class="container border-75">Container 2 (alpha = 0.75)</div>
<div class="container border-50">Container 3 (alpha = 0.5)</div>
<div class="container border-25">Container 4 (alpha = 0.25)</div>
_x000D_
_x000D_
_x000D_

How do you comment out code in PowerShell?

Use a hashtag followed by a white-space(!) for this:

 # comment here

Do not forget the whitespace here! Otherwise it can interfere with internal commands.

E.g. this is NOT a comment:

#requires -runasadmin

Relative div height

The div take the height of its parent, but since it has no content (expecpt for your divs) it will only be as height as its content.

You need to set the height of the body and html:

HTML:

<div class="block12">
    <div class="block1">1</div>
    <div class="block2">2</div>
</div>
<div class="block3">3</div>

CSS:

body, html {
    width: 100%;
    height: 100%;
    margin: 0;
    padding: 0;
}
.block12 {
    width: 100%;
    height: 50%;
    background: yellow;
    overflow: auto;
}
.block1, .block2 {
    width: 50%;
    height: 100%;
    display: inline-block;
    margin-right: -4px;
    background: lightgreen;
}
.block2 { background: lightgray }
.block3 {
    width: 100%;
    height: 50%;
    background: lightblue;
}

And a JSFiddle

Convert char to int in C and C++

Presumably you want this conversion for using functions from the C standard library.

In that case, do (C++ syntax)

typedef unsigned char UChar;

char myCppFunc( char c )
{
    return char( someCFunc( UChar( c ) ) );
}

The expression UChar( c ) converts to unsigned char in order to get rid of negative values, which, except for EOF, are not supported by the C functions.

Then the result of that expression is used as actual argument for an int formal argument. Where you get automatic promotion to int. You can alternatively write that last step explicitly, like int( UChar( c ) ), but personally I find that too verbose.

Cheers & hth.,

Facebook login "given URL not allowed by application configuration"

I was getting this problem while using a tunnel because I:

  1. had the tunnel url:port set in the FB app settings
  2. but was accessing the local server by pointing my browser to "http://localhost:3000"

once i started punching the tunnel url:port into the browser, i was good to go.

i'm using Rails and Facebooker, but might help others just the same.

Create auto-numbering on images/figures in MS Word

Office 2007

Right click the figure, select Insert Caption, Select Numbering, check box next to 'Include chapter number', select OK, Select OK again, then you figure identifier should be updated.

Setting environment variables in Linux using Bash

VAR=value sets VAR to value.

After that export VAR will give it to child processes too.

export VAR=value is a shorthand doing both.

Binding ng-model inside ng-repeat loop in AngularJS

For each iteration of the ng-repeat loop, line is a reference to an object in your array. Therefore, to preview the value, use {{line.text}}.

Similarly, to databind to the text, databind to the same: ng-model="line.text". You don't need to use value when using ng-model (actually you shouldn't).

Fiddle.

For a more in-depth look at scopes and ng-repeat, see What are the nuances of scope prototypal / prototypical inheritance in AngularJS?, section ng-repeat.

Date minus 1 year?

On my website, to check if registering people is 18 years old, I simply used the following :

$legalAge = date('Y-m-d', strtotime('-18 year'));

After, only compare the the two dates.

Hope it could help someone.

What's the difference between all the Selection Segues?

The document has moved here it seems: https://help.apple.com/xcode/mac/8.0/#/dev564169bb1

Can't copy the icons here, but here are the descriptions:

  • Show: Present the content in the detail or master area depending on the content of the screen.

    If the app is displaying a master and detail view, the content is pushed onto the detail area. If the app is only displaying the master or the detail, the content is pushed on top of the current view controller stack.

  • Show Detail: Present the content in the detail area.

    If the app is displaying a master and detail view, the new content replaces the current detail. If the app is only displaying the master or the detail, the content replaces the top of the current view controller stack.

  • Present Modally: Present the content modally.

  • Present as Popover: Present the content as a popover anchored to an existing view.

  • Custom: Create your own behaviors by using a custom segue.

How to increase MaximumErrorCount in SQL Server 2008 Jobs or Packages?

If I have open a package in BIDS ("Business Intelligence Development Studio", the tool you use to design the packages), and do not select any item in it, I have a "Properties" pane in the bottom right containing - among others, the MaximumErrorCount property. If you do not see it, maybe it is minimized and you have to open it (have a look at tabs in the right).

If you cannot find it this way, try the menu: View/Properties Window.

Or try the F4 key.

When creating a service with sc.exe how to pass in context parameters?

I couldn't handle the issue with your proposals, at the end with the x86 folder it only worked in power shell (windows server 2012) using environment variables:

{sc.exe create svnserve binpath= "${env:programfiles(x86)}/subversion/bin/svnserve.exe --service -r C:/svnrepositories/"   displayname= "Subversion Server" depend= Tcpip start= auto}

How to center cards in bootstrap 4?

Update 2018

There is no need for extra CSS, and there are multiple centering methods in Bootstrap 4:

  • text-center for center display:inline elements
  • mx-auto for centering display:block elements inside display:flex (d-flex)
  • offset-* or mx-auto can be used to center grid columns
  • or justify-content-center on row to center grid columns

mx-auto (auto x-axis margins) will center inside display:flex elements that have a defined width, (%, vw, px, etc..). Flexbox is used by default on grid columns, so there are also various centering methods.

In your case, you can simply mx-auto to the cards.

Maven artifact and groupId naming

Consider this to get a fully unique jar file:

  • GroupID - com.companyname.project
  • ArtifactId - com-companyname-project
  • Package - com.companyname.project

How to fix git error: RPC failed; curl 56 GnuTLS

To solve this issue:

Rebuilding git with openssl instead of gnutls fixed my problem.

I followed these instructions

Set CFLAGS and CXXFLAGS options using CMake

On Unix systems, for several projects, I added these lines into the CMakeLists.txt and it was compiling successfully because base (/usr/include) and local includes (/usr/local/include) go into separated directories:

set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -I/usr/local/include -L/usr/local/lib")
set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -I/usr/local/include")
set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} -L/usr/local/lib")

It appends the correct directory, including paths for the C and C++ compiler flags and the correct directory path for the linker flags.

Note: C++ compiler (c++) doesn't support -L, so we have to use CMAKE_EXE_LINKER_FLAGS

C++: How to round a double to an int?

#include <iostream>
#include <cmath>
using namespace std;

int main()
{
    double x=54.999999999999943157;
    int y=ceil(x);//The ceil() function returns the smallest integer no less than x
    return 0;
}

Why am I getting an error "Object literal may only specify known properties"?

As of TypeScript 1.6, properties in object literals that do not have a corresponding property in the type they're being assigned to are flagged as errors.

Usually this error means you have a bug (typically a typo) in your code, or in the definition file. The right fix in this case would be to fix the typo. In the question, the property callbackOnLoactionHash is incorrect and should have been callbackOnLocationHash (note the mis-spelling of "Location").

This change also required some updates in definition files, so you should get the latest version of the .d.ts for any libraries you're using.

Example:

interface TextOptions {
    alignment?: string;
    color?: string;
    padding?: number;
}
function drawText(opts: TextOptions) { ... }
drawText({ align: 'center' }); // Error, no property 'align' in 'TextOptions'

But I meant to do that

There are a few cases where you may have intended to have extra properties in your object. Depending on what you're doing, there are several appropriate fixes

Type-checking only some properties

Sometimes you want to make sure a few things are present and of the correct type, but intend to have extra properties for whatever reason. Type assertions (<T>v or v as T) do not check for extra properties, so you can use them in place of a type annotation:

interface Options {
    x?: string;
    y?: number;
}

// Error, no property 'z' in 'Options'
let q1: Options = { x: 'foo', y: 32, z: 100 };
// OK
let q2 = { x: 'foo', y: 32, z: 100 } as Options;
// Still an error (good):
let q3 = { x: 100, y: 32, z: 100 } as Options;

These properties and maybe more

Some APIs take an object and dynamically iterate over its keys, but have 'special' keys that need to be of a certain type. Adding a string indexer to the type will disable extra property checking

Before

interface Model {
  name: string;
}
function createModel(x: Model) { ... }

// Error
createModel({name: 'hello', length: 100});

After

interface Model {
  name: string;
  [others: string]: any;
}
function createModel(x: Model) { ... }

// OK
createModel({name: 'hello', length: 100});

This is a dog or a cat or a horse, not sure yet

interface Animal { move; }
interface Dog extends Animal { woof; }
interface Cat extends Animal { meow; }
interface Horse extends Animal { neigh; }

let x: Animal;
if(...) {
  x = { move: 'doggy paddle', woof: 'bark' };
} else if(...) {
  x = { move: 'catwalk', meow: 'mrar' };
} else {
  x = { move: 'gallop', neigh: 'wilbur' };
}

Two good solutions come to mind here

Specify a closed set for x

// Removes all errors
let x: Dog|Cat|Horse;

or Type assert each thing

// For each initialization
  x = { move: 'doggy paddle', woof: 'bark' } as Dog;

This type is sometimes open and sometimes not

A clean solution to the "data model" problem using intersection types:

interface DataModelOptions {
  name?: string;
  id?: number;
}
interface UserProperties {
  [key: string]: any;
}
function createDataModel(model: DataModelOptions & UserProperties) {
 /* ... */
}
// findDataModel can only look up by name or id
function findDataModel(model: DataModelOptions) {
 /* ... */
}
// OK
createDataModel({name: 'my model', favoriteAnimal: 'cat' });
// Error, 'ID' is not correct (should be 'id')
findDataModel({ ID: 32 });

See also https://github.com/Microsoft/TypeScript/issues/3755

vue.js 'document.getElementById' shorthand

you can find your answer in the combination of these two pages in the API:

ref is used to register a reference to an element or a child component. The reference will be registered under the parent component’s $refs object. If used on a plain DOM element, the reference will be that element

An object that holds child components that have ref registered.

Algorithm to generate all possible permutations of a list?

I know this a very very old and even off-topic in today's stackoverflow but I still wanted to contribute a friendly javascript answer for the simple reason that it runs in your browser.

I've also added the debugger directive breakpoint so you can step through the code (chrome required) to see how this algorithm works. Open up your dev console in chrome (F12 in windows or CMD + OPTION + I on mac) and then click "Run code snippet". This implements the same exact algorithm that @WhirlWind presented in his answer.

Your browser should pause execution at the debugger directive. Use F8 to continue code execution.

Step through the code and see how it works!

_x000D_
_x000D_
function permute(rest, prefix = []) {_x000D_
  if (rest.length === 0) {_x000D_
    return [prefix];_x000D_
  }_x000D_
  return (rest_x000D_
    .map((x, index) => {_x000D_
      const oldRest = rest;_x000D_
      const oldPrefix = prefix;_x000D_
      // the `...` destructures the array into single values flattening it_x000D_
      const newRest = [...rest.slice(0, index), ...rest.slice(index + 1)];_x000D_
      const newPrefix = [...prefix, x];_x000D_
      debugger;_x000D_
_x000D_
      const result = permute(newRest, newPrefix);_x000D_
      return result;_x000D_
    })_x000D_
    // this step flattens the array of arrays returned by calling permute_x000D_
    .reduce((flattened, arr) => [...flattened, ...arr], [])_x000D_
  );_x000D_
}_x000D_
console.log(permute([1, 2, 3]));
_x000D_
_x000D_
_x000D_

Class method decorator with self arguments?

Another option would be to abandon the syntactic sugar and decorate in the __init__ of the class.

def countdown(number):
    def countdown_decorator(func):
        def func_wrapper():
            for index in reversed(range(1, number+1)):
                print(index)
            func()
        return func_wrapper
    return countdown_decorator

class MySuperClass():
    def __init__(self, number):
        self.number = number
        self.do_thing = countdown(number)(self.do_thing)
    
    def do_thing(self):
        print('im doing stuff!')


myclass = MySuperClass(3)

myclass.do_thing()

which would print

3
2
1
im doing stuff!

Pandas conditional creation of a series/dataframe column

You can simply use the powerful .loc method and use one condition or several depending on your need (tested with pandas=1.0.5).

Code Summary:

df=pd.DataFrame(dict(Type='A B B C'.split(), Set='Z Z X Y'.split()))
df['Color'] = "red"
df.loc[(df['Set']=="Z"), 'Color'] = "green"

#practice!
df.loc[(df['Set']=="Z")&(df['Type']=="B")|(df['Type']=="C"), 'Color'] = "purple"

Explanation:

df=pd.DataFrame(dict(Type='A B B C'.split(), Set='Z Z X Y'.split()))

# df so far: 
  Type Set  
0    A   Z 
1    B   Z 
2    B   X 
3    C   Y

add a 'color' column and set all values to "red"

df['Color'] = "red"

Apply your single condition:

df.loc[(df['Set']=="Z"), 'Color'] = "green"


# df: 
  Type Set  Color
0    A   Z  green
1    B   Z  green
2    B   X    red
3    C   Y    red

or multiple conditions if you want:

df.loc[(df['Set']=="Z")&(df['Type']=="B")|(df['Type']=="C"), 'Color'] = "purple"

You can read on Pandas logical operators and conditional selection here: Logical operators for boolean indexing in Pandas

Error: unable to verify the first certificate in nodejs

unable to verify the first certificate

The certificate chain is incomplete.

It means that the webserver you are connecting to is misconfigured and did not include the intermediate certificate in the certificate chain it sent to you.

Certificate chain

It most likely looks as follows:

  1. Server certificate - stores a certificate signed by intermediate.
  2. Intermediate certificate - stores a certificate signed by root.
  3. Root certificate - stores a self-signed certificate.

Intermediate certificate should be installed on the server, along with the server certificate.
Root certificates are embedded into the software applications, browsers and operating systems.

The application serving the certificate has to send the complete chain, this means the server certificate itself and all the intermediates. The root certificate is supposed to be known by the client.

Recreate the problem

Go to https://incomplete-chain.badssl.com using your browser.

It doesn't show any error (padlock in the address bar is green).
It's because browsers tend to complete the chain if it’s not sent from the server.

Now, connect to https://incomplete-chain.badssl.com using Node:

// index.js
const axios = require('axios');

axios.get('https://incomplete-chain.badssl.com')
  .then(function (response) {
    console.log(response);
  })
  .catch(function (error) {
    console.log(error);
  });

Logs: "Error: unable to verify the first certificate".

Solution

You need to complete the certificate chain yourself.

To do that:

1: You need to get the missing intermediate certificate in .pem format, then

2a: extend Node’s built-in certificate store using NODE_EXTRA_CA_CERTS,

2b: or pass your own certificate bundle (intermediates and root) using ca option.

1. How do I get intermediate certificate?

Using openssl (comes with Git for Windows).

Save the remote server's certificate details:

openssl s_client -connect incomplete-chain.badssl.com:443 -servername incomplete-chain.badssl.com | tee logcertfile

We're looking for the issuer (the intermediate certificate is the issuer / signer of the server certificate):

openssl x509 -in logcertfile -noout -text | grep -i "issuer"

It should give you URI of the signing certificate. Download it:

curl --output intermediate.crt http://cacerts.digicert.com/DigiCertSHA2SecureServerCA.crt

Finally, convert it to .pem:

openssl x509 -inform DER -in intermediate.crt -out intermediate.pem -text

2a. NODE_EXTRA_CERTS

I'm using cross-env to set environment variables in package.json file:

"start": "cross-env NODE_EXTRA_CA_CERTS=\"C:\\Users\\USERNAME\\Desktop\\ssl-connect\\intermediate.pem\" node index.js"

2b. ca option

This option is going to overwrite the Node's built-in root CAs.

That's why we need to create our own root CA. Use ssl-root-cas.

Then, create a custom https agent configured with our certificate bundle (root and intermediate). Pass this agent to axios when making request.

// index.js
const axios = require('axios');
const path = require('path');
const https = require('https');
const rootCas = require('ssl-root-cas').create();

rootCas.addFile(path.resolve(__dirname, 'intermediate.pem'));
const httpsAgent = new https.Agent({ca: rootCas});

axios.get('https://incomplete-chain.badssl.com', { httpsAgent })
  .then(function (response) {
    console.log(response);
  })
  .catch(function (error) {
    console.log(error);
  });

Instead of creating a custom https agent and passing it to axios, you can place the certifcates on the https global agent:

// Applies to ALL requests (whether using https directly or the request module)
https.globalAgent.options.ca = rootCas;

Resources:

  1. https://levelup.gitconnected.com/how-to-resolve-certificate-errors-in-nodejs-app-involving-ssl-calls-781ce48daded
  2. https://www.npmjs.com/package/ssl-root-cas
  3. https://github.com/nodejs/node/issues/16336
  4. https://www.namecheap.com/support/knowledgebase/article.aspx/9605/69/how-to-check-ca-chain-installation
  5. https://superuser.com/questions/97201/how-to-save-a-remote-server-ssl-certificate-locally-as-a-file/
  6. How to convert .crt to .pem

Difference between return and exit in Bash functions

The OP's question: What is the difference between the return and exit statement in BASH functions with respect to exit codes?

Firstly, some clarification is required:

  • A (return|exit) statement is not required to terminate execution of a (function|shell). A (function|shell) will terminate when it reaches the end of its code list, even with no (return|exit) statement.

  • A (return|exit) statement is not required to pass a value back from a terminated (function|shell). Every process has a built-in variable $? which always has a numeric value. It is a special variable that cannot be set like "?=1", but it is set only in special ways (see below *).

    The value of $? after the last command to be executed in the (called function | sub shell) is the value that is passed back to the (function caller | parent shell). That is true whether the last command executed is ("return [n]"| "exit [n]") or plain ("return" or something else which happens to be the last command in the called function's code.

In the above bullet list, choose from "(x|y)" either always the first item or always the second item to get statements about functions and return, or shells and exit, respectively.

What is clear is that they both share common usage of the special variable $? to pass values upwards after they terminate.

* Now for the special ways that $? can be set:

  • When a called function terminates and returns to its caller then $? in the caller will be equal to the final value of $? in the terminated function.
  • When a parent shell implicitly or explicitly waits on a single sub shell and is released by termination of that sub shell, then $? in the parent shell will be equal to the final value of $? in the terminated sub shell.
  • Some built-in functions can modify $? depending upon their result. But some don't.
  • Built-in functions "return" and "exit", when followed by a numerical argument both $? with argument, and terminate execution.

It is worth noting that $? can be assigned a value by calling exit in a sub shell, like this:

# (exit 259)
# echo $?
3

Dynamically load JS inside JS

You can use jQuery's $.getScript() method to do it but if you want a more full feature one, yepnope.js is your choice. It supports conditional loading of scripts and stylesheets and it's easy to use.

In PHP, how do you change the key of an array element?

Easy stuff:

this function will accept the target $hash and $replacements is also a hash containing newkey=>oldkey associations.

This function will preserve original order, but could be problematic for very large (like above 10k records) arrays regarding performance & memory.

function keyRename(array $hash, array $replacements) {
    $new=array();
    foreach($hash as $k=>$v)
    {
        if($ok=array_search($k,$replacements))
            $k=$ok;
        $new[$k]=$v;
    }
    return $new;    
}

this alternative function would do the same, with far better performance & memory usage, at the cost of loosing original order (which should not be a problem since it is hashtable!)

function keyRename(array $hash, array $replacements) {

    foreach($hash as $k=>$v)
        if($ok=array_search($k,$replacements))
        {
          $hash[$ok]=$v;
          unset($hash[$k]);
        }

    return $hash;       
}

Merge two Excel tables Based on matching data in Columns

Put the table in the second image on Sheet2, columns D to F.

In Sheet1, cell D2 use the formula

=iferror(vlookup($A2,Sheet2!$D$1:$F$100,column(A1),false),"")

copy across and down.

Edit: here is a picture. The data is in two sheets. On Sheet1, enter the formula into cell D2. Then copy the formula across to F2 and then down as many rows as you need.

enter image description here

Python Pandas - Missing required dependencies ['numpy'] 1

I also faced the same issue. It happened to me after I upgraded my numpy library. It was resolved in my case by upgrading my pandas library as well after upgrading my numpy library using the below command:

pip install --upgrade pandas

Python: Continuing to next iteration in outer loop

for ii in range(200):
    for jj in range(200, 400):
        ...block0...
        if something:
            break
    else:
        ...block1...

Break will break the inner loop, and block1 won't be executed (it will run only if the inner loop is exited normally).

How do you install Boost on MacOS?

Fink appears to have a full set of Boost packages...

With fink installed and running just do

fink install boost1.35.nopython

at the terminal and accept the dependencies it insists on. Or use

fink list boost

to get a list of different packages that are availible.

What is the exact location of MySQL database tables in XAMPP folder?

If you are like me, and manually installed your webserver without using Xampp or some other installer,

Your data is probably stored at C:\ProgramData\MySQL\MySQL Server 5.6\data

Joining two table entities in Spring Data JPA

For a typical example of employees owning one or more phones, see this wikibook section.

For your specific example, if you want to do a one-to-one relationship, you should change the next code in ReleaseDateType model:

@Column(nullable = true) 
private Integer media_Id;

for:

@OneToOne(fetch = FetchType.LAZY)
@JoinColumn(name="CACHE_MEDIA_ID", nullable=true)
private CacheMedia cacheMedia ;

and in CacheMedia model you need to add:

@OneToOne(cascade=ALL, mappedBy="ReleaseDateType")
private ReleaseDateType releaseDateType;

then in your repository you should replace:

@Query("Select * from A a  left join B b on a.id=b.id")
public List<ReleaseDateType> FindAllWithDescriptionQuery();

by:

//In this case a query annotation is not need since spring constructs the query from the method name
public List<ReleaseDateType> findByCacheMedia_Id(Integer id); 

or by:

@Query("FROM ReleaseDateType AS rdt WHERE cm.rdt.cacheMedia.id = ?1")    //This is using a named query method
public List<ReleaseDateType> FindAllWithDescriptionQuery(Integer id);

Or if you prefer to do a @OneToMany and @ManyToOne relation, you should change the next code in ReleaseDateType model:

@Column(nullable = true) 
private Integer media_Id;

for:

@OneToMany(cascade=ALL, mappedBy="ReleaseDateType")
private List<CacheMedia> cacheMedias ;

and in CacheMedia model you need to add:

@ManyToOne(fetch = FetchType.LAZY)
@JoinColumn(name="RELEASE_DATE_TYPE_ID", nullable=true)
private ReleaseDateType releaseDateType;

then in your repository you should replace:

@Query("Select * from A a  left join B b on a.id=b.id")
public List<ReleaseDateType> FindAllWithDescriptionQuery();

by:

//In this case a query annotation is not need since spring constructs the query from the method name
public List<ReleaseDateType> findByCacheMedias_Id(Integer id); 

or by:

@Query("FROM ReleaseDateType AS rdt LEFT JOIN rdt.cacheMedias AS cm WHERE cm.id = ?1")    //This is using a named query method
public List<ReleaseDateType> FindAllWithDescriptionQuery(Integer id);

Format date in a specific timezone

.zone() has been deprecated, and you should use utcOffset instead:

// for a timezone that is +7 UTC hours
moment(1369266934311).utcOffset(420).format('YYYY-MM-DD HH:mm')

Differences between Emacs and Vim

  1. Vim was always faster to start up than Emacs. I'm saying that on any machine, out-of-the-box installs of Vim will start up faster than out-of-the-box installs of Emacs. And I tend to think that after a moderate amount of customisation of either one, Vim will still start up faster than Emacs.

  2. After that, the other practical difference was Emacs' modes. They make your life tremendously easier when editing XML, C/C++/Java/whatever, LaTeX, and most popular languages you can think of. They make you want to keep the editor open for long sessions and work.

All in all, I'll say that Vim pulls you to it for short, fast editing tasks; while Emacs encourages you to dive in for long sessions.

How to reposition Chrome Developer Tools

Chrome 46 or newer

Click the vertical ellipsis button ( ? ) then choose the desired docking option.

Chrome 45 or older

Long-hold the dock icon in the top right. It pops up an option to change the docking

To change the split between the HTML and CSS panels, go in DevTools to Settings (F1) > General > Appearance > Panel Layout.

How to deal with http status codes other than 200 in Angular 2

Yes you can handle with the catch operator like this and show alert as you want but firstly you have to import Rxjs for the same like this way

import {Observable} from 'rxjs/Rx';

return this.http.request(new Request(this.requestoptions))
            .map((res: Response) => {
                if (res) {
                    if (res.status === 201) {
                        return [{ status: res.status, json: res }]
                    }
                    else if (res.status === 200) {
                        return [{ status: res.status, json: res }]
                    }
                }
            }).catch((error: any) => {
                if (error.status === 500) {
                    return Observable.throw(new Error(error.status));
                }
                else if (error.status === 400) {
                    return Observable.throw(new Error(error.status));
                }
                else if (error.status === 409) {
                    return Observable.throw(new Error(error.status));
                }
                else if (error.status === 406) {
                    return Observable.throw(new Error(error.status));
                }
            });
    }

also you can handel error (with err block) that is throw by catch block while .map function,

like this -

...
.subscribe(res=>{....}
           err => {//handel here});

Update

as required for any status without checking particluar one you can try this: -

return this.http.request(new Request(this.requestoptions))
            .map((res: Response) => {
                if (res) {
                    if (res.status === 201) {
                        return [{ status: res.status, json: res }]
                    }
                    else if (res.status === 200) {
                        return [{ status: res.status, json: res }]
                    }
                }
            }).catch((error: any) => {
                if (error.status < 400 ||  error.status ===500) {
                    return Observable.throw(new Error(error.status));
                }
            })
            .subscribe(res => {...},
                       err => {console.log(err)} );

How do I put text on ProgressBar?

I wold create a control named for example InfoProgresBar, that provide this functionality with a label or two (Main Job, Current Job) and ProgressBar and use it instead of that ProgressBar.

How do I request and process JSON with python?

For anything with requests to URLs you might want to check out requests. For JSON in particular:

>>> import requests
>>> r = requests.get('https://github.com/timeline.json')
>>> r.json()
[{u'repository': {u'open_issues': 0, u'url': 'https://github.com/...

How do I compute derivative using Numpy?

You can use scipy, which is pretty straight forward:

scipy.misc.derivative(func, x0, dx=1.0, n=1, args=(), order=3)

Find the nth derivative of a function at a point.

In your case:

from scipy.misc import derivative

def f(x):
    return x**2 + 1

derivative(f, 5, dx=1e-6)
# 10.00000000139778

Apache HttpClient Android (Gradle)

I don't know why but (for now) httpclient can be compiled only as a jar into the libs directory in your project. HttpCore works fine when it is included from mvn like that:

dependencies {
      compile 'org.apache.httpcomponents:httpcore:4.4.3'
}

Restore the mysql database from .frm files

After much trial and error I was able to get this working based on user359187 answer and this blog post.

To get my old .frm and .ibd transferred to a new MySQL database after copying the files over and assigning MySQL ownership, the key for me was to then log into MySQL and connect to the new database then let MySQL do the work by importing the tablespace.

mysql> connect test;
mysql> ALTER TABLE t1 IMPORT TABLESPACE;

This will import the data using the copied .frm and .ibd files.

I had to run the Alter command for each table separately but this worked and I was able to recover the tables and data.

Why does my JavaScript code receive a "No 'Access-Control-Allow-Origin' header is present on the requested resource" error, while Postman does not?

The error you get is due to the CORS standard, which sets some restrictions on how JavaScript can perform ajax requests.

The CORS standard is a client-side standard, implemented in the browser. So it is the browser which prevent the call from completing and generates the error message - not the server.

Postman does not implement the CORS restrictions, which is why you don't see the same error when making the same call from Postman.

How do I activate C++ 11 in CMake?

CMake 3.1 introduced the CMAKE_CXX_STANDARD variable that you can use. If you know that you will always have CMake 3.1 or later available, you can just write this in your top-level CMakeLists.txt file, or put it right before any new target is defined:

set (CMAKE_CXX_STANDARD 11)

If you need to support older versions of CMake, here is a macro I came up with that you can use:

macro(use_cxx11)
  if (CMAKE_VERSION VERSION_LESS "3.1")
    if (CMAKE_CXX_COMPILER_ID STREQUAL "GNU")
      set (CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=gnu++11")
    endif ()
  else ()
    set (CMAKE_CXX_STANDARD 11)
  endif ()
endmacro(use_cxx11)

The macro only supports GCC right now, but it should be straight-forward to expand it to other compilers.

Then you could write use_cxx11() at the top of any CMakeLists.txt file that defines a target that uses C++11.

CMake issue #15943 for clang users targeting macOS

If you are using CMake and clang to target macOS there is a bug that can cause the CMAKE_CXX_STANDARD feature to simply not work (not add any compiler flags). Make sure that you do one of the following things:

  • Use cmake_minimum_required to require CMake 3.0 or later, or

  • Set policy CMP0025 to NEW with the following code at the top of your CMakeLists.txt file before the project command:

      # Fix behavior of CMAKE_CXX_STANDARD when targeting macOS.
      if (POLICY CMP0025)
        cmake_policy(SET CMP0025 NEW)
      endif ()
    

React JSX: selecting "selected" on selected <select> option

***Html:***
<div id="divContainer"></div>

var colors = [{ Name: 'Red' }, { Name: 'Green' }, { Name: 'Blue' }];
var selectedColor = 'Green';

ReactDOM.render(<Container></Container>, document.getElementById("divContainer"));

var Container = React.createClass({
    render: function () {
        return (
        <div>            
            <DropDown data={colors} Selected={selectedColor}></DropDown>
        </div>);
    }
});

***Option 1:***
var DropDown = React.createClass(
{
    render: function () {
        var items = this.props.data;
        return (
        <select value={this.props.Selected}>
            {
                items.map(function (item) {
                    return <option value={item.Name }>{item.Name}</option>;
                })
            }
        </select>);
    }
});

***Option 2:***
var DropDown = React.createClass(
{
    render: function () {
        var items = this.props.data;
        return (
        <select>
            {
                items.map(function (item) {
                    return <option value={item.Name} selected={selectedItem == item.Name}>{item.Name}</option>;
                })
            }
        </select>);
    }
});

***Option 3:***
var DropDown = React.createClass(
    {
        render: function () {
            var items = this.props.data;
            return (
            <select>
                {
                    items.map(function (item) {

                                            if (selectedItem == item.Name)
                    return <option value={item.Name } selected>{item.Name}</option>;
                else
                    return <option value={item.Name }>{item.Name}</option>;
                    })
                }
            </select>);
        }
    });

How do I create a foreign key in SQL Server?

Necromancing.
Actually, doing this correctly is a little bit trickier.

You first need to check if the primary-key exists for the column you want to set your foreign key to reference to.

In this example, a foreign key on table T_ZO_SYS_Language_Forms is created, referencing dbo.T_SYS_Language_Forms.LANG_UID

-- First, chech if the table exists...
IF 0 < (
    SELECT COUNT(*) FROM INFORMATION_SCHEMA.TABLES 
    WHERE TABLE_TYPE = 'BASE TABLE'
    AND TABLE_SCHEMA = 'dbo'
    AND TABLE_NAME = 'T_SYS_Language_Forms'
)
BEGIN
    -- Check for NULL values in the primary-key column
    IF 0 = (SELECT COUNT(*) FROM T_SYS_Language_Forms WHERE LANG_UID IS NULL)
    BEGIN
        ALTER TABLE T_SYS_Language_Forms ALTER COLUMN LANG_UID uniqueidentifier NOT NULL 

        -- No, don't drop, FK references might already exist...
        -- Drop PK if exists 
        -- ALTER TABLE T_SYS_Language_Forms DROP CONSTRAINT pk_constraint_name 
        --DECLARE @pkDropCommand nvarchar(1000) 
        --SET @pkDropCommand = N'ALTER TABLE T_SYS_Language_Forms DROP CONSTRAINT ' + QUOTENAME((SELECT CONSTRAINT_NAME FROM INFORMATION_SCHEMA.TABLE_CONSTRAINTS 
        --WHERE CONSTRAINT_TYPE = 'PRIMARY KEY' 
        --AND TABLE_SCHEMA = 'dbo' 
        --AND TABLE_NAME = 'T_SYS_Language_Forms' 
        ----AND CONSTRAINT_NAME = 'PK_T_SYS_Language_Forms' 
        --))
        ---- PRINT @pkDropCommand 
        --EXECUTE(@pkDropCommand) 

        -- Instead do
        -- EXEC sp_rename 'dbo.T_SYS_Language_Forms.PK_T_SYS_Language_Forms1234565', 'PK_T_SYS_Language_Forms';


        -- Check if they keys are unique (it is very possible they might not be) 
        IF 1 >= (SELECT TOP 1 COUNT(*) AS cnt FROM T_SYS_Language_Forms GROUP BY LANG_UID ORDER BY cnt DESC)
        BEGIN

            -- If no Primary key for this table
            IF 0 =  
            (
                SELECT COUNT(*) FROM INFORMATION_SCHEMA.TABLE_CONSTRAINTS 
                WHERE CONSTRAINT_TYPE = 'PRIMARY KEY' 
                AND TABLE_SCHEMA = 'dbo' 
                AND TABLE_NAME = 'T_SYS_Language_Forms' 
                -- AND CONSTRAINT_NAME = 'PK_T_SYS_Language_Forms' 
            )
                ALTER TABLE T_SYS_Language_Forms ADD CONSTRAINT PK_T_SYS_Language_Forms PRIMARY KEY CLUSTERED (LANG_UID ASC)
            ;

            -- Adding foreign key
            IF 0 = (SELECT COUNT(*) FROM INFORMATION_SCHEMA.REFERENTIAL_CONSTRAINTS WHERE CONSTRAINT_NAME = 'FK_T_ZO_SYS_Language_Forms_T_SYS_Language_Forms') 
                ALTER TABLE T_ZO_SYS_Language_Forms WITH NOCHECK ADD CONSTRAINT FK_T_ZO_SYS_Language_Forms_T_SYS_Language_Forms FOREIGN KEY(ZOLANG_LANG_UID) REFERENCES T_SYS_Language_Forms(LANG_UID); 
        END -- End uniqueness check
        ELSE
            PRINT 'FSCK, this column has duplicate keys, and can thus not be changed to primary key...' 
    END -- End NULL check
    ELSE
        PRINT 'FSCK, need to figure out how to update NULL value(s)...' 
END 

Detecting scroll direction

Simple way to catch all scroll events (touch and wheel)

window.onscroll = function(e) {
  // print "false" if direction is down and "true" if up
  console.log(this.oldScroll > this.scrollY);
  this.oldScroll = this.scrollY;
}

How to trap the backspace key using jQuery?

Working on the same idea as above , but generalizing a bit . Since the backspace should work fine on the input elements , but should not work if the focus is a paragraph or something , since it is there where the page tends to go back to the previous page in history .

$('html').on('keydown' , function(event) {

        if(! $(event.target).is('input')) {
            console.log(event.which);
           //event.preventDefault();
           if(event.which == 8) {
            //  alert('backspace pressed');
            return false;
         }
        }
});

returning false => both event.preventDefault and event.stopPropagation are in effect .

Return multiple values from a function, sub or type?

Ideas :

  1. Use pass by reference (ByRef)
  2. Build a User Defined Type to hold the stuff you want to return, and return that.
  3. Similar to 2 - build a class to represent the information returned, and return objects of that class...

Using margin / padding to space <span> from the rest of the <p>

Use div instead of span, or add display: block; to your css style for the span tag.

Auto-indent spaces with C in vim?

A lot of vim's features (like autoindent and cindent) are turned off by default. To really see what vim can do for you, you need a decent ~/.vimrc.

A good starter one is in $VIMRUNTIME/vimrc_example.vim. If you want to try it out, use

:source $VIMRUNTIME/vimrc_example.vim

when in vim.

I'd actually suggest just copying the contents to your ~/.vimrc as it's well commented, and a good place to start learning how to use vim. You can do this by

:e $VIMRUNTIME/vimrc_example.vim
:w! ~/.vimrc

This will overwrite your current ~/.vimrc, but if all you have in there is the indent settings Davr suggested, I wouldn't sweat it, as the example vimrc will take care of that for you as well. For a complete walkthrough of the example, and what it does for you, see :help vimrc-intro.

How to create a custom navigation drawer in android

Android Navigation Drawer using Activity I just followed the example :http://antonioleiva.com/navigation-view/

You just need few Customization:

public class MainActivity extends AppCompatActivity  {

public static final String AVATAR_URL = "http://lorempixel.com/200/200/people/1/";


private DrawerLayout drawerLayout;
private View content;
private Toolbar toolbar;
private NavigationView navigationView;
private ActionBarDrawerToggle drawerToggle;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_dashboard);
    toolbar = (Toolbar) findViewById(R.id.toolbar);
    drawerLayout = (DrawerLayout) findViewById(R.id.drawer_layout);
    initToolbar();
    setupDrawerLayout();

    content = findViewById(R.id.content);
    drawerToggle = setupDrawerToggle();
    final ImageView avatar = (ImageView) navigationView.getHeaderView(0).findViewById(R.id.avatar);
    Picasso.with(this).load(AVATAR_URL).transform(new CircleTransform()).into(avatar);


}


private void initToolbar() {
    final Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
    setSupportActionBar(toolbar);
    final ActionBar actionBar = getSupportActionBar();

    if (actionBar != null) {
        actionBar.setHomeAsUpIndicator(R.drawable.ic_menu_black_24dp);
        actionBar.setDisplayHomeAsUpEnabled(true);
    }
}
private ActionBarDrawerToggle setupDrawerToggle() {
    return new ActionBarDrawerToggle(this, drawerLayout, toolbar, R.string.drawer_open,  R.string.drawer_close);
}

   @Override
protected void onPostCreate(Bundle savedInstanceState) {
    super.onPostCreate(savedInstanceState);
    // Sync the toggle state after onRestoreInstanceState has occurred.
    drawerToggle.syncState();
}

@Override
public void onConfigurationChanged(Configuration newConfig) {
    super.onConfigurationChanged(newConfig);
    // Pass any configuration change to the drawer toggles
    drawerToggle.onConfigurationChanged(newConfig);
}
 private void setupDrawerLayout() {

    drawerLayout = (DrawerLayout) findViewById(R.id.drawer_layout);
    navigationView = (NavigationView) findViewById(R.id.navigation_view);

    navigationView.setNavigationItemSelectedListener(new NavigationView.OnNavigationItemSelectedListener() {

        @Override
        public boolean onNavigationItemSelected(MenuItem menuItem) {

            int id = menuItem.getItemId();

          switch (id) {
                case R.id.drawer_home:
                    Intent i = new Intent(getApplicationContext(), MainActivity.class);
                    startActivity(i);
                    finish();
                    break;
                case R.id.drawer_favorite:
                    Intent j = new Intent(getApplicationContext(), SecondActivity.class);
                    startActivity(j);
                    finish();
                    break;

            }


        return true;
    }
});

} Here is the xml Layout

<android.support.v4.widget.DrawerLayout
android:id="@+id/drawer_layout"
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:fitsSystemWindows="true"
tools:context=".MainActivity">

<FrameLayout
    android:id="@+id/content"
    android:layout_width="match_parent"
    android:layout_height="match_parent">



    <android.support.design.widget.AppBarLayout
        android:id="@+id/appBarLayout"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar">

        <android.support.v7.widget.Toolbar
            android:id="@+id/toolbar"
            android:layout_width="match_parent"
            android:layout_height="?attr/actionBarSize"
            android:background="?attr/colorPrimary"
            app:popupTheme="@style/ThemeOverlay.AppCompat.Light"
            app:layout_scrollFlags="scroll|enterAlways|snap" />

    </android.support.design.widget.AppBarLayout>



</FrameLayout>

<android.support.design.widget.NavigationView
    android:id="@+id/navigation_view"
    android:layout_width="wrap_content"
    android:layout_height="match_parent"
    android:layout_gravity="start"
    app:headerLayout="@layout/drawer_header"
    app:menu="@menu/drawer"/>

Add drawer.xml in menu

<menu xmlns:android="http://schemas.android.com/apk/res/android">

<group
    android:checkableBehavior="single">

    <item
        android:id="@+id/drawer_home"
        android:checked="true"
        android:icon="@drawable/ic_home_black_24dp"
        android:title="@string/home"/>

    <item
        android:id="@+id/drawer_favourite"
        android:icon="@drawable/ic_favorite_black_24dp"
        android:title="@string/favourite"/>
    ...

    <item
        android:id="@+id/drawer_settings"
        android:icon="@drawable/ic_settings_black_24dp"
        android:title="@string/settings"/>

</group>

To open and close drawer add this values in string.xml

<string name="drawer_open">Open</string>
<string name="drawer_close">Close</string>

drawer.xml

enter code here

<ImageView
    android:id="@+id/avatar"
    android:layout_width="64dp"
    android:layout_height="64dp"
    android:layout_margin="@dimen/spacing_large"
    android:elevation="4dp"
    tools:src="@drawable/ic_launcher"/>

<TextView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_above="@+id/email"
    android:layout_marginLeft="@dimen/spacing_large"
    android:layout_marginStart="@dimen/spacing_large"
    android:text="Username"
    android:textAppearance="@style/TextAppearance.AppCompat.Body2"/>
<TextView
    android:id="@+id/email"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignParentBottom="true"
    android:layout_marginLeft="@dimen/spacing_large"
    android:layout_marginStart="@dimen/spacing_large"
    android:layout_marginBottom="@dimen/spacing_large"
    android:text="[email protected]"
    android:textAppearance="@style/TextAppearance.AppCompat.Body1"/>

When do you use POST and when do you use GET?

Use POST for destructive actions such as creation (I'm aware of the irony), editing, and deletion, because you can't hit a POST action in the address bar of your browser. Use GET when it's safe to allow a person to call an action. So a URL like:

http://myblog.org/admin/posts/delete/357

Should bring you to a confirmation page, rather than simply deleting the item. It's far easier to avoid accidents this way.

POST is also more secure than GET, because you aren't sticking information into a URL. And so using GET as the method for an HTML form that collects a password or other sensitive information is not the best idea.

One final note: POST can transmit a larger amount of information than GET. 'POST' has no size restrictions for transmitted data, whilst 'GET' is limited to 2048 characters.

Rename multiple files in a folder, add a prefix (Windows)

Option 1: Using Windows PowerShell

Open the windows menu. Type: "PowerShell" and open the 'Windows PowerShell' command window.

Goto folder with desired files: e.g. cd "C:\house chores" Notice: address must incorporate quotes "" if there are spaces involved.

You can use 'dir' to see all the files in the folder. Using '|' will pipeline the output of 'dir' for the command that follows.

Notes: 'dir' is an alias of 'Get-ChildItem'. See: wiki: cmdlets. One can provide further functionality. e.g. 'dir -recurse' outputs all the files, folders and sub-folders.

What if I only want a range of files?

Instead of 'dir |' I can use:

dir | where-object -filterscript {($_.Name -ge 'DSC_20') -and ($_.Name -le 'DSC_31')} |

For batch-renaming with the directory name as a prefix:

dir | Rename-Item -NewName {$_.Directory.Name + " - " + $_.Name}

Option 2: Using Command Prompt

In the folder press shift+right-click : select 'open command-window here'

for %a in (*.*) do ren "%a" "prefix - %a"

If there are a lot of files, it might be good to add an '@echo off' command before this and an 'echo on' command at the end.

Show a number to two decimal places

  • Choose the number of decimals
  • Format commas(,)
  • An option to trim trailing zeros

Once and for all!

function format_number($number,$dec=0,$trim=false){
  if($trim){
    $parts = explode(".",(round($number,$dec) * 1));
    $dec = isset($parts[1]) ? strlen($parts[1]) : 0;
  }
  $formatted = number_format($number,$dec); 
  return $formatted;
}

Examples

echo format_number(1234.5,2,true); //returns 1,234.5
echo format_number(1234.5,2);      //returns 1,234.50
echo format_number(1234.5);        //returns 1,235

Fix columns in horizontal scrolling

SOLVED

http://jsfiddle.net/DJqPf/7/

.table-wrapper { 
    overflow-x:scroll;
    overflow-y:visible;
    width:250px;
    margin-left: 120px;
}
td, th {
    padding: 5px 20px;
    width: 100px;
}
th:first-child {
    position: fixed;
    left: 5px
}

UPDATE

_x000D_
_x000D_
$(function () {  _x000D_
  $('.table-wrapper tr').each(function () {_x000D_
    var tr = $(this),_x000D_
        h = 0;_x000D_
    tr.children().each(function () {_x000D_
      var td = $(this),_x000D_
          tdh = td.height();_x000D_
      if (tdh > h) h = tdh;_x000D_
    });_x000D_
    tr.css({height: h + 'px'});_x000D_
  });_x000D_
});
_x000D_
body {_x000D_
    position: relative;_x000D_
}_x000D_
.table-wrapper { _x000D_
    overflow-x:scroll;_x000D_
    overflow-y:visible;_x000D_
    width:200px;_x000D_
    margin-left: 120px;_x000D_
}_x000D_
_x000D_
_x000D_
td, th {_x000D_
    padding: 5px 20px;_x000D_
    width: 100px;_x000D_
}_x000D_
tbody tr {_x000D_
  _x000D_
}_x000D_
th:first-child {_x000D_
    position: absolute;_x000D_
    left: 5px_x000D_
}
_x000D_
<!DOCTYPE html>_x000D_
<html>_x000D_
<head>_x000D_
<script src="https://code.jquery.com/jquery-2.2.3.min.js"></script>_x000D_
  <meta charset="utf-8">_x000D_
  <title>JS Bin</title>_x000D_
</head>_x000D_
<body>_x000D_
<div>_x000D_
    <h1>SOME RANDOM TEXT</h1>_x000D_
</div>_x000D_
<div class="table-wrapper">_x000D_
    <table id="consumption-data" class="data">_x000D_
        <thead class="header">_x000D_
            <tr>_x000D_
                <th>Month</th>_x000D_
                <th>Item 1</th>_x000D_
                <th>Item 2</th>_x000D_
                <th>Item 3</th>_x000D_
                <th>Item 4</th>_x000D_
            </tr>_x000D_
        </thead>_x000D_
        <tbody class="results">_x000D_
            <tr>_x000D_
                <th>Jan is an awesome month</th>_x000D_
                <td>3163</td>_x000D_
                <td>3163</td>_x000D_
                <td>3163</td>_x000D_
                <td>3163</td>_x000D_
            </tr>_x000D_
            <tr>_x000D_
                <th>Feb</th>_x000D_
                <td>3163</td>_x000D_
                <td>3163</td>_x000D_
                <td>3163</td>_x000D_
                <td>3163</td>_x000D_
            </tr>_x000D_
            <tr>_x000D_
                <th>Mar</th>_x000D_
                <td>3163</td>_x000D_
                <td>3163</td>_x000D_
                <td>3163</td>_x000D_
                <td>3163</td>_x000D_
            </tr>_x000D_
            <tr>_x000D_
                <th>Apr</th>_x000D_
                <td>3163</td>_x000D_
                <td>3163</td>_x000D_
                <td>3163</td>_x000D_
                <td>3163</td>  _x000D_
            </tr>_x000D_
            <tr>    _x000D_
                <th>May</th>_x000D_
                <td>3163</td>_x000D_
                <td>3163</td>_x000D_
                <td>3163</td>_x000D_
                <td>3163</td>_x000D_
            </tr>_x000D_
            <tr>_x000D_
                <th>Jun</th>_x000D_
                <td>3163</td>_x000D_
                <td>3163</td>_x000D_
                <td>3163</td>_x000D_
                <td>3163</td>_x000D_
            </tr>_x000D_
_x000D_
            <tr>_x000D_
                <th>...</th>_x000D_
                <td>...</td>_x000D_
                <td>...</td>_x000D_
                <td>...</td>_x000D_
                <td>...</td>_x000D_
            </tr>_x000D_
        </tbody>_x000D_
    </table>_x000D_
</div>_x000D_
_x000D_
<div>_x000D_
</div>_x000D_
</body>_x000D_
</html>
_x000D_
_x000D_
_x000D_

How do I use a file grep comparison inside a bash if/else statement?

From grep --help, but also see man grep:

Exit status is 0 if any line was selected, 1 otherwise; if any error occurs and -q was not given, the exit status is 2.

if grep --quiet MYSQL_ROLE=master /etc/aws/hosts.conf; then
  echo exists
else
  echo not found
fi

You may want to use a more specific regex, such as ^MYSQL_ROLE=master$, to avoid that string in comments, names that merely start with "master", etc.

This works because the if takes a command and runs it, and uses the return value of that command to decide how to proceed, with zero meaning true and non-zero meaning false—the same as how other return codes are interpreted by the shell, and the opposite of a language like C.

How to set MouseOver event/trigger for border in XAML?

Yes, this is confusing...

According to this blog post, it looks like this is an omission from WPF.

To make it work you need to use a style:

    <Border Name="ClearButtonBorder" Grid.Column="1" CornerRadius="0,3,3,0">
        <Border.Style>
            <Style>
                <Setter Property="Border.Background" Value="Blue"/>
                <Style.Triggers>
                    <Trigger Property="Border.IsMouseOver" Value="True">
                        <Setter Property="Border.Background" Value="Green" />
                    </Trigger>
                </Style.Triggers>
            </Style>
        </Border.Style>
        <TextBlock HorizontalAlignment="Center" VerticalAlignment="Center" Text="X" />
    </Border>

I guess this problem isn't that common as most people tend to factor out this sort of thing into a style, so it can be used on multiple controls.

Convert JSON String to JSON Object c#

if you don't want or need a typed object try:

using Newtonsoft.Json;
// ...   
dynamic json  = JsonConvert.DeserializeObject(str);

or try for a typed object try:

Foo json  = JsonConvert.DeserializeObject<Foo>(str)

jquery .live('click') vs .click()

In addition to T.J. Crowders answer, I have added some more handlers - including the newer .on(...) handler to the snippet so you can see which events are being hidden and which ones not.

What I also found is that .live() is not only deprecated, but was deleted since jQuery 1.9.x. But the other ones, i.e.
.click, .delegate/.undelegate and .on/.off
are still there.

Also note there is more discussion about this topic here on Stackoverflow.

If you need to fix legacy code that is relying on .live, but you require to use a new version of jQuery (> 1.8.3), you can fix it with this snippet:

// fix if legacy code uses .live, but you want to user newer jQuery library
if (!$.fn.live) {
    // in this case .live does not exist, emulate .live by calling .on
    $.fn.live = function(events, handler) {
      $(this).on(events, null, {}, handler);
    };
}

The intention of the snippet below, which is an extension of T.J.'s script, is that you can try out by yourself instantly what happens if you bind multiple handlers - so please run the snippet and click on the texts below:

_x000D_
_x000D_
jQuery(function($) {_x000D_
_x000D_
  // .live connects function with all spans_x000D_
  $('span').live('click', function() {_x000D_
    display("<tt>live</tt> caught a click!");_x000D_
  });_x000D_
_x000D_
  // --- catcher1 events ---_x000D_
_x000D_
  // .click connects function with id='catcher1'_x000D_
  $('#catcher1').click(function() {_x000D_
    display("Click Catcher1 caught a click and prevented <tt>live</tt> from seeing it.");_x000D_
    return false;_x000D_
  });_x000D_
_x000D_
  // --- catcher2 events ---_x000D_
_x000D_
  // .click connects function with id='catcher2'_x000D_
  $('#catcher2').click(function() {_x000D_
    display("Click Catcher2 caught a click and prevented <tt>live</tt>, <tt>delegate</tt> and <tt>on</tt> from seeing it.");_x000D_
    return false;_x000D_
  });_x000D_
_x000D_
  // .delegate connects function with id='catcher2'_x000D_
  $(document).delegate('#catcher2', 'click', function() {_x000D_
    display("Delegate Catcher2 caught a click and prevented <tt>live</tt> from seeing it.");_x000D_
    return false;_x000D_
  });_x000D_
_x000D_
  // .on connects function with id='catcher2'_x000D_
  $(document).on('click', '#catcher2', {}, function() {_x000D_
    display("On Catcher2 caught a click and prevented <tt>live</tt> from seeing it.");_x000D_
    return false;_x000D_
  });_x000D_
_x000D_
  // --- catcher3 events ---_x000D_
_x000D_
  // .delegate connects function with id='catcher3'_x000D_
  $(document).delegate('#catcher3', 'click', function() {_x000D_
    display("Delegate Catcher3 caught a click and <tt>live</tt> and <tt>on</tt> can see it.");_x000D_
    return false;_x000D_
  });_x000D_
_x000D_
  // .on connects function with id='catcher3'_x000D_
  $(document).on('click', '#catcher3', {}, function() {_x000D_
    display("On Catcher3 caught a click and and <tt>live</tt> and <tt>delegate</tt> can see it.");_x000D_
    return false;_x000D_
  });_x000D_
_x000D_
  function display(msg) {_x000D_
    $("<p>").html(msg).appendTo(document.body);_x000D_
  }_x000D_
_x000D_
});
_x000D_
<!-- with JQuery 1.8.3 it still works, but .live was removed since 1.9.0 -->_x000D_
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.8.3/jquery.min.js">_x000D_
</script>_x000D_
_x000D_
<style>_x000D_
span.frame {_x000D_
    line-height: 170%; border-style: groove;_x000D_
}_x000D_
</style>_x000D_
_x000D_
<div>_x000D_
  <span class="frame">Click me</span>_x000D_
  <span class="frame">or me</span>_x000D_
  <span class="frame">or me</span>_x000D_
  <div>_x000D_
    <span class="frame">I'm two levels in</span>_x000D_
    <span class="frame">so am I</span>_x000D_
  </div>_x000D_
  <div id='catcher1'>_x000D_
    <span class="frame">#1 - I'm two levels in AND my parent interferes with <tt>live</tt></span>_x000D_
    <span class="frame">me too</span>_x000D_
  </div>_x000D_
  <div id='catcher2'>_x000D_
    <span class="frame">#2 - I'm two levels in AND my parent interferes with <tt>live</tt></span>_x000D_
    <span class="frame">me too</span>_x000D_
  </div>_x000D_
  <div id='catcher3'>_x000D_
    <span class="frame">#3 - I'm two levels in AND my parent interferes with <tt>live</tt></span>_x000D_
    <span class="frame">me too</span>_x000D_
  </div>_x000D_
</div>
_x000D_
_x000D_
_x000D_

Convert Numeric value to Varchar

i think it should be

select convert(varchar(10),StandardCost) +'S' from DimProduct where ProductKey = 212

or

select cast(StandardCost as varchar(10)) + 'S' from DimProduct where ProductKey = 212

Should I use SVN or Git?

I would set up a Subversion repository. By doing it this way, individual developers can choose whether to use Subversion clients or Git clients (with git-svn). Using git-svn doesn't give you all the benefits of a full Git solution, but it does give individual developers a great deal of control over their own workflow.

I believe it will be a relatively short time before Git works just as well on Windows as it does on Unix and Mac OS X (since you asked).

Subversion has excellent tools for Windows, such as TortoiseSVN for Explorer integration and AnkhSVN for Visual Studio integration.

What do these three dots in React do?

It is common practice to pass props around in a React application. In doing this we able to apply state changes to the child component regardless of whether it is Pure or Impure (stateless or stateful). There are times when the best approach, when passing in props, is to pass in singular properties or an entire object of properties. With the support for arrays in ES6 we were given the "..." notation and with this we are now able to achieve passing an entire object to a child.

The typical process of passing props to a child is noted with this syntax:

var component = <Component foo={x} bar={y} />;

This is fine to use when the number of props is minimal but becomes unmanageable when the prop numbers get too much higher. A problem with this method occurs when you do not know the properties needed within a child component and the typical JavaScript method is to simple set those properties and bind to the object later. This causes issues with propType checking and cryptic stack trace errors that are not helpful and cause delays in debugging. The following is an example of this practice, and what not to do:

var component = <Component />;
component.props.foo = x; // bad
component.props.bar = y;

This same result can be achieved but with more appropriate success by doing this:

var props = {};
props.foo = x;
props.bar = y;
var component = Component(props); // Where did my JSX go?

But does not use JSX spread or JSX so to loop this back into the equation we can now do something like this:

var props = {};
props.foo = x;
props.bar = y;
var component = <Component {...props} />;

The properties included in "...props" are foo: x, bar: y. This can be combined with other attributes to override the properties of "...props" using this syntax:

var props = { foo: 'default' };
var component = <Component {...props} foo={'override'} />;
console.log(component.props.foo); // 'override'

In addition we can copy other property objects onto each other or combine them in this manner:

var oldObj = { foo: 'hello', bar: 'world' };
var newObj = { ...oldObj, foo: 'hi' };
console.log(newObj.foo); // 'hi';
console.log(newObj.bar); // 'world';

Or merge two different objects like this (this is not yet available in all react versions):

var ab = { ...a, ...b }; // merge(a, b)

Another way of explaining this, according to Facebook's react/docs site is:

If you already have "props" as an object, and you want to pass it in JSX, you can use "..." as a SPREAD operator to pass the whole props object. The following two examples are equivalent:

function App1() {
  return <Greeting firstName="Ben" lastName="Hector" />;
}



function App2() {
  const props = {firstName: 'Ben', lastName: 'Hector'};
  return <Greeting {...props} />;
}

Spread attributes can be useful when you are building generic containers. However, they can also make your code messy by making it easy to pass a lot of irrelevant props to components that don't care about them. This syntax should be used sparingly.

Remove an element from a Bash array

The following works as you would like in bash and zsh:

$ array=(pluto pippo)
$ delete=pluto
$ echo ${array[@]/$delete}
pippo
$ array=( "${array[@]/$delete}" ) #Quotes when working with strings

If need to delete more than one element:

...
$ delete=(pluto pippo)
for del in ${delete[@]}
do
   array=("${array[@]/$del}") #Quotes when working with strings
done

Caveat

This technique actually removes prefixes matching $delete from the elements, not necessarily whole elements.

Update

To really remove an exact item, you need to walk through the array, comparing the target to each element, and using unset to delete an exact match.

array=(pluto pippo bob)
delete=(pippo)
for target in "${delete[@]}"; do
  for i in "${!array[@]}"; do
    if [[ ${array[i]} = $target ]]; then
      unset 'array[i]'
    fi
  done
done

Note that if you do this, and one or more elements is removed, the indices will no longer be a continuous sequence of integers.

$ declare -p array
declare -a array=([0]="pluto" [2]="bob")

The simple fact is, arrays were not designed for use as mutable data structures. They are primarily used for storing lists of items in a single variable without needing to waste a character as a delimiter (e.g., to store a list of strings which can contain whitespace).

If gaps are a problem, then you need to rebuild the array to fill the gaps:

for i in "${!array[@]}"; do
    new_array+=( "${array[i]}" )
done
array=("${new_array[@]}")
unset new_array

How to limit file upload type file size in PHP?

Hope this helps :-)

if(isset($_POST['submit'])){
    ini_set("post_max_size", "30M");
    ini_set("upload_max_filesize", "30M");
    ini_set("memory_limit", "20000M"); 
    $fileName='product_demo.png';

    if($_FILES['imgproduct']['size'] > 0 && 
            (($_FILES["imgproduct"]["type"] == "image/gif") || 
                ($_FILES["imgproduct"]["type"] == "image/jpeg")|| 
                ($_FILES["imgproduct"]["type"] == "image/pjpeg") || 
                ($_FILES["imgproduct"]["type"] == "image/png") &&
                ($_FILES["imgproduct"]["size"] < 2097152))){

        if ($_FILES["imgproduct"]["error"] > 0){
            echo "Return Code: " . $_FILES["imgproduct"]["error"] . "<br />";
        } else {    
            $rnd=rand(100,999);
            $rnd=$rnd."_";
            $fileName = $rnd.trim($_FILES['imgproduct']['name']);
            $tmpName  = $_FILES['imgproduct']['tmp_name'];
            $fileSize = $_FILES['imgproduct']['size'];
            $fileType = $_FILES['imgproduct']['type'];  
            $target = "upload/";
            echo $target = $target .$rnd. basename( $_FILES['imgproduct']['name']) ; 
            move_uploaded_file($_FILES['imgproduct']['tmp_name'], $target);
        }
    } else {
        echo "Sorry, there was a problem uploading your file.";
    }
}

Detect backspace and del on "input" event?

$('div[contenteditable]').keydown(function(e) {
// trap the return key being pressed
if (e.keyCode === 13 || e.keyCode === 8)
{
    return false;
}
});

Passing an Object from an Activity to a Fragment

In your activity class:

public class BasicActivity extends Activity {

private ComplexObject co;

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

    co=new ComplexObject();
    getIntent().putExtra("complexObject", co);

    FragmentManager fragmentManager = getFragmentManager();
    Fragment1 f1 = new Fragment1();
    fragmentManager.beginTransaction()
            .replace(R.id.frameLayout, f1).commit();

}

Note: Your object should implement Serializable interface

Then in your fragment :

public class Fragment1 extends Fragment {

ComplexObject co;

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
        Bundle savedInstanceState) {
    Intent i = getActivity().getIntent();

    co = (ComplexObject) i.getSerializableExtra("complexObject");

    View view = inflater.inflate(R.layout.test_page, container, false);
    TextView textView = (TextView) view.findViewById(R.id.DENEME);
    textView.setText(co.getName());

    return view;
}
}

Forking / Multi-Threaded Processes | Bash

Here's my thread control function:

#!/bin/bash
# This function just checks jobs in background, don't do more things.
# if jobs number is lower than MAX, then return to get more jobs;
# if jobs number is greater or equal to MAX, then wait, until someone finished.

# Usage:
#   thread_max 8
#   thread_max 0    # wait, until all jobs completed

thread_max() {
    local CHECK_INTERVAL="3s"
    local CUR_THREADS=
    local MAX=
    [[ $1 ]] && MAX=$1 || return 127

    # reset MAX value, 0 is easy to remember
    [ $MAX -eq 0 ] && {
        MAX=1
        DEBUG "waiting for all tasks finish"
    }

    while true; do
        CUR_THREADS=`jobs -p | wc -w`

        # workaround about jobs bug. If don't execute it explicitily,
        # CUR_THREADS will stick at 1, even no jobs running anymore.
        jobs &>/dev/null

        DEBUG "current thread amount: $CUR_THREADS"
        if [ $CUR_THREADS -ge $MAX ]; then
            sleep $CHECK_INTERVAL
        else
            return 0
        fi
    done
}

How to use ImageBackground to set background image for screen in react-native

Two options:

  1. Try setting width and height to width and height of the device screen
  2. Good old position absolute

Code for #2:

 render(){
    return(
        <View style={{ flex: 1 }}>
           <Image style={{ width: screenWidth, height: screenHeight, position: 'absolute', top: 0, left: 0 }}/>
           <Text>Hey look, image background</Text>
        </View>
    )
}

Edit: For option #2 you can experiment with resizeMode="stretch|cover"

Edit 2: Keep in mind that option #2 renders the image and then everything after that in this order, which means that some pixels are rendered twice, this might have a very small performance impact (usually unnoticeable) but just for your information

What's the best way to test SQL Server connection programmatically?

Here is my version based on the @peterincumbria answer:

using var scope = _serviceProvider.CreateScope();
var dbContext = scope.ServiceProvider.GetRequiredService<AppDbContext>();
return await dbContext.Database.CanConnectAsync(cToken);

I'm using Observable for polling health checking by interval and handling return value of the function. try-catch is not needed here because: enter image description here

How do I use Node.js Crypto to create a HMAC-SHA1 hash?

A few years ago it was said that update() and digest() were legacy methods and the new streaming API approach was introduced. Now the docs say that either method can be used. For example:

var crypto    = require('crypto');
var text      = 'I love cupcakes';
var secret    = 'abcdeg'; //make this your secret!!
var algorithm = 'sha1';   //consider using sha256
var hash, hmac;

// Method 1 - Writing to a stream
hmac = crypto.createHmac(algorithm, secret);    
hmac.write(text); // write in to the stream
hmac.end();       // can't read from the stream until you call end()
hash = hmac.read().toString('hex');    // read out hmac digest
console.log("Method 1: ", hash);

// Method 2 - Using update and digest:
hmac = crypto.createHmac(algorithm, secret);
hmac.update(text);
hash = hmac.digest('hex');
console.log("Method 2: ", hash);

Tested on node v6.2.2 and v7.7.2

See https://nodejs.org/api/crypto.html#crypto_class_hmac. Gives more examples for using the streaming approach.

Read url to string in few lines of java code

Additional example using Guava:

URL xmlData = ...
String data = Resources.toString(xmlData, Charsets.UTF_8);

How to work on UAC when installing XAMPP

This is a specific issue for Windows Vista, 7, 8 (and presumably newer).

User Account Control (UAC) is a feature in Windows that can help you stay in control of your computer by informing you when a program makes a change that requires administrator-level permission. UAC works by adjusting the permission level of your user account.

This is applied mostly to C:\Program Files. You may have noticed sometimes, that some applications can see files in C:\Program Files that does not exist there. You know why? Windows now tend to have "C:\Program Files" folder customized for every user. For example, old applications store config files (like .ini) in the same folder where the executable files are stored. In the good old days all users had the same configurations for such apps. In nowadays Windows stores configs in the special folder tied to the user account. Thus, now different users may have different configs while application still think that config files are in the same folder with the executables.

XAMPP does not like to have different config for different users. In fact it is not a config file for XAMPP, it is folders where you keep your projects and databases. The idea of XAMPP is to make projects same for all users. This is a source of a conflict with Windows.

All you need is to avoid installing XAMPP into C:\Program Files. Thus XAMPP will always use the original files for all users and there would be no confusion.

I recommend to install XAMPP into the special folder in root directory like in C:\XAMPP. But before you choose the folder you need to click on this warning message.

How to code a BAT file to always run as admin mode?

  1. My experimenting indicates that the runas command must include the admin user's domain (at least it does in my organization's environmental setup):

    runas /user:AdminDomain\AdminUserName ExampleScript.bat
    

    If you don’t already know the admin user's domain, run an instance of Command Prompt as the admin user, and enter the following command:

    echo %userdomain%
    
  2. The answers provided by both Kerrek SB and Ed Greaves will execute the target file under the admin user but, if the file is a Command script (.bat file) or VB script (.vbs file) which attempts to operate on the normal-login user’s environment (such as changing registry entries), you may not get the desired results because the environment under which the script actually runs will be that of the admin user, not the normal-login user! For example, if the file is a script that operates on the registry’s HKEY_CURRENT_USER hive, the affected “current-user” will be the admin user, not the normal-login user.

How to get JSON from URL in JavaScript?

You can use jQuery .getJSON() function:

$.getJSON('http://query.yahooapis.com/v1/public/yql?q=select%20%2a%20from%20yahoo.finance.quotes%20WHERE%20symbol%3D%27WRC%27&format=json&diagnostics=true&env=store://datatables.org/alltableswithkeys&callback', function(data) {
    // JSON result in `data` variable
});

If you don't want to use jQuery you should look at this answer for pure JS solution: https://stackoverflow.com/a/2499647/1361042

1030 Got error 28 from storage engine

A simple: $sth->finish(); Would probably save you from worrying about this. Mysql uses the system's tmp space instead of it's own space.

Setting state on componentDidMount()

The only reason that the linter complains about using setState({..}) in componentDidMount and componentDidUpdate is that when the component render the setState immediately causes the component to re-render. But the most important thing to note: using it inside these component's lifecycles is not an anti-pattern in React.

Please take a look at this issue. you will understand more about this topic. Thanks for reading my answer.

SQL Server 2008: How to query all databases sizes?

please find more deatils or download the script from below link https://gallery.technet.microsoft.com/SIZE-OF-ALL-DATABASES-IN-0337f6d5#content

 DECLARE @spacetable table
 (
 database_name varchar(50) ,
 total_size_data int,
 space_util_data int,
 space_data_left int,
 percent_fill_data float,
 total_size_data_log int,
 space_util_log int,
 space_log_left int,
 percent_fill_log char(50),
 [total db size] int,
 [total size used] int,
 [total size left] int
 )
 insert into  @spacetable
 EXECUTE master.sys.sp_MSforeachdb 'USE [?];
 select x.[DATABASE NAME],x.[total size data],x.[space util],x.[total size data]-x.[space util] [space left data],
 x.[percent fill],y.[total size log],y.[space util],
 y.[total size log]-y.[space util] [space left log],y.[percent fill],
 y.[total size log]+x.[total size data] ''total db size''
 ,x.[space util]+y.[space util] ''total size used'',
 (y.[total size log]+x.[total size data])-(y.[space util]+x.[space util]) ''total size left''
  from (select DB_NAME() ''DATABASE NAME'',
 sum(size*8/1024) ''total size data'',sum(FILEPROPERTY(name,''SpaceUsed'')*8/1024) ''space util''
 ,case when sum(size*8/1024)=0 then ''less than 1% used'' else
 substring(cast((sum(FILEPROPERTY(name,''SpaceUsed''))*1.0*100/sum(size)) as CHAR(50)),1,6) end ''percent fill''
 from sys.master_files where database_id=DB_ID(DB_NAME())  and  type=0
 group by type_desc  ) as x ,
 (select 
 sum(size*8/1024) ''total size log'',sum(FILEPROPERTY(name,''SpaceUsed'')*8/1024) ''space util''
 ,case when sum(size*8/1024)=0 then ''less than 1% used'' else
 substring(cast((sum(FILEPROPERTY(name,''SpaceUsed''))*1.0*100/sum(size)) as CHAR(50)),1,6) end ''percent fill''
 from sys.master_files where database_id=DB_ID(DB_NAME())  and  type=1
 group by type_desc  )y'
 select * from @spacetable
 order by database_name

How to select all instances of a variable and edit variable name in Sublime

It's mentioned by @watsonic that in Sublime Text 3 on Mac OS, starting with an empty selection, simply ^?G (AltF3 on Windows) does the trick, instead of ?D + ^?G in Sublime Text 2.

How to keep Docker container running after starting services?

Make sure that you add daemon off; to you nginx.conf or run it with CMD ["nginx", "-g", "daemon off;"] as per the official nginx image

Then use the following to run both supervisor as service and nginx as foreground process that will prevent the container from exiting

service supervisor start && nginx

In some cases you will need to have more than one process in your container, so forcing the container to have exactly one process won't work and can create more problems in deployment.

So you need to understand the trade-offs and make your decision accordingly.

Check whether a cell contains a substring

Check out the FIND() function in Excel.

Syntax:

FIND( substring, string, [start_position])

Returns #VALUE! if it doesn't find the substring.

Merging dictionaries in C#

The party's pretty much dead now, but here's an "improved" version of user166390 that made its way into my extension library. Apart from some details, I added a delegate to calculate the merged value.

/// <summary>
/// Merges a dictionary against an array of other dictionaries.
/// </summary>
/// <typeparam name="TResult">The type of the resulting dictionary.</typeparam>
/// <typeparam name="TKey">The type of the key in the resulting dictionary.</typeparam>
/// <typeparam name="TValue">The type of the value in the resulting dictionary.</typeparam>
/// <param name="source">The source dictionary.</param>
/// <param name="mergeBehavior">A delegate returning the merged value. (Parameters in order: The current key, The current value, The previous value)</param>
/// <param name="mergers">Dictionaries to merge against.</param>
/// <returns>The merged dictionary.</returns>
public static TResult MergeLeft<TResult, TKey, TValue>(
    this TResult source,
    Func<TKey, TValue, TValue, TValue> mergeBehavior,
    params IDictionary<TKey, TValue>[] mergers)
    where TResult : IDictionary<TKey, TValue>, new()
{
    var result = new TResult();
    var sources = new List<IDictionary<TKey, TValue>> { source }
        .Concat(mergers);

    foreach (var kv in sources.SelectMany(src => src))
    {
        TValue previousValue;
        result.TryGetValue(kv.Key, out previousValue);
        result[kv.Key] = mergeBehavior(kv.Key, kv.Value, previousValue);
    }

    return result;
}

Java: Date from unix timestamp

tl;dr

Instant.ofEpochSecond( 1_280_512_800L )

2010-07-30T18:00:00Z

java.time

The new java.time framework built into Java 8 and later is the successor to Joda-Time.

These new classes include a handy factory method to convert a count of whole seconds from epoch. You get an Instant, a moment on the timeline in UTC with up to nanoseconds resolution.

Instant instant = Instant.ofEpochSecond( 1_280_512_800L );

instant.toString(): 2010-07-30T18:00:00Z

See that code run live at IdeOne.com.

Table of date-time types in Java, both modern and legacy

Asia/Kabul or Asia/Tehran time zones ?

You reported getting a time-of-day value of 22:30 instead of the 18:00 seen here. I suspect your PHP utility is implicitly applying a default time zone to adjust from UTC. My value here is UTC, signified by the Z (short for Zulu, means UTC). Any chance your machine OS or PHP is set to Asia/Kabul or Asia/Tehran time zones? I suppose so as you report IRST in your output which apparently means Iran time. Currently in 2017 those are the only zones operating with a summer time that is four and a half hours ahead of UTC.

Specify a proper time zone name in the format of continent/region, such as America/Montreal, Africa/Casablanca, or Pacific/Auckland. Never use the 3-4 letter abbreviation such as EST or IST or IRST as they are not true time zones, not standardized, and not even unique(!).

If you want to see your moment through the lens of a particular region's time zone, apply a ZoneId to get a ZonedDateTime. Still the same simultaneous moment, but seen as a different wall-clock time.

ZoneId z = ZoneId.of( "Asia/Tehran" ) ;
ZonedDateTime zdt = instant.atZone( z );  // Same moment, same point on timeline, but seen as different wall-clock time.

2010-07-30T22:30+04:30[Asia/Tehran]

Converting from java.time to legacy classes

You should stick with the new java.time classes. But you can convert to old if required.

java.util.Date date = java.util.Date.from( instant );

Joda-Time

UPDATE: The Joda-Time project is now in maintenance mode, with the team advising migration to the java.time classes.

FYI, the constructor for a Joda-Time DateTime is similar: Multiply by a thousand to produce a long (not an int!).

DateTime dateTime = new DateTime( ( 1_280_512_800L * 1000_L ), DateTimeZone.forID( "Europe/Paris" ) );

Best to avoid the notoriously troublesome java.util.Date and .Calendar classes. But if you must use a Date, you can convert from Joda-Time.

java.util.Date date = dateTime.toDate();

About java.time

The java.time framework is built into Java 8 and later. These classes supplant the troublesome old legacy date-time classes such as java.util.Date, Calendar, & SimpleDateFormat.

The Joda-Time project, now in maintenance mode, advises migration to the java.time classes.

To learn more, see the Oracle Tutorial. And search Stack Overflow for many examples and explanations. Specification is JSR 310.

You may exchange java.time objects directly with your database. Use a JDBC driver compliant with JDBC 4.2 or later. No need for strings, no need for java.sql.* classes.

Where to obtain the java.time classes?

The ThreeTen-Extra project extends java.time with additional classes. This project is a proving ground for possible future additions to java.time. You may find some useful classes here such as Interval, YearWeek, YearQuarter, and more.

How can I change the value of the elements in a vector?

Well, you could always run a transform over the vector:

std::transform(v.begin(), v.end(), v.begin(), [mean](int i) -> int { return i - mean; });

You could always also devise an iterator adapter that returns the result of an operation applied to the dereference of its component iterator when it's dereferenced. Then you could just copy the vector to the output stream:

std::copy(adapter(v.begin(), [mean](int i) -> { return i - mean; }), v.end(), std::ostream_iterator<int>(cout, "\n"));

Or, you could use a for loop...but that's kind of boring.

JavaScript post request like a form submit

This is based on beauSD's code using jQuery. It is improved so it works recursively on objects.

function post(url, params, urlEncoded, newWindow) {
    var form = $('<form />').hide();
    form.attr('action', url)
        .attr('method', 'POST')
        .attr('enctype', urlEncoded ? 'application/x-www-form-urlencoded' : 'multipart/form-data');
    if(newWindow) form.attr('target', '_blank');

    function addParam(name, value, parent) {
        var fullname = (parent.length > 0 ? (parent + '[' + name + ']') : name);
        if(value instanceof Object) {
            for(var i in value) {
                addParam(i, value[i], fullname);
            }
        }
        else $('<input type="hidden" />').attr({name: fullname, value: value}).appendTo(form);
    };

    addParam('', params, '');

    $('body').append(form);
    form.submit();
}

Get the first item from an iterable that matches a condition

Oneliner:

thefirst = [i for i in range(10) if i > 3][0]

If youre not sure that any element will be valid according to the criteria, you should enclose this with try/except since that [0] can raise an IndexError.

how to create virtual host on XAMPP

I fixed it using following configuration.

 Listen 85
 <VirtualHost *:85>
           DocumentRoot "C:/xampp/htdocs/LaraBlog/public"
           <Directory "C:/xampp/htdocs/CommunicationApp/public">
           DirectoryIndex index.php
           AllowOverride All
           Order allow,deny
           Allow from all
           </Directory>
 </VirtualHost>

Add a new line to the end of a JtextArea

When you want to create a new line or wrap in your TextArea you have to add \n (newline) after the text.

TextArea t = new TextArea();
t.setText("insert text when you want a new line add \nThen more text....);
setBounds();
setFont();
add(t);

This is the only way I was able to do it, maybe there is a simpler way but I havent discovered that yet.

bootstrap datepicker change date event doesnt fire up when manually editing dates or clearing date

In version 2.1.5

changeDate has been renamed to change.dp so changedate was not working for me

$("#datetimepicker").datetimepicker().on('change.dp', function (e) {
            FillDate(new Date());
    });

also needed to change css class from datepicker to datepicker-input

<div id='datetimepicker' class='datepicker-input input-group controls'>
   <input id='txtStartDate' class='form-control' placeholder='Select datepicker' data-rule-required='true' data-format='MM-DD-YYYY' type='text' />
   <span class='input-group-addon'>
       <span class='icon-calendar' data-time-icon='icon-time' data-date-icon='icon-calendar'></span>
   </span>
</div>

Date formate also works in capitals like this data-format='MM-DD-YYYY'

it might be helpful for someone it gave me really hard time :)

Git - remote: Repository not found

I was also facing the same issue

remote: Repository not found
fatal: repository 'https://github.com/MyRepo/project.git/' not found

I uninstalled the git credentials manager and reinstalled it and then I could easily pull and push to the repository. Here are the commands

$ git credential-manager uninstall

$ git credential-manager install

How to use sudo inside a docker container?

There is no answer on how to do this on CentOS. On Centos, you can add following to Dockerfile

RUN echo "user ALL=(root) NOPASSWD:ALL" > /etc/sudoers.d/user && \
    chmod 0440 /etc/sudoers.d/user