Programs & Examples On #Squashfs

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

Abstract classes are not required to implement the methods. So even though it implements an interface, the abstract methods of the interface can remain abstract. If you try to implement an interface in a concrete class (i.e. not abstract) and you do not implement the abstract methods the compiler will tell you: Either implement the abstract methods or declare the class as abstract.

What is the best way to get the first letter from a string in Java, returned as a string of length 1?

import org.openjdk.jmh.annotations.Benchmark;
import org.openjdk.jmh.annotations.BenchmarkMode;
import org.openjdk.jmh.annotations.Fork;
import org.openjdk.jmh.annotations.Measurement;
import org.openjdk.jmh.annotations.Mode;
import org.openjdk.jmh.annotations.OutputTimeUnit;
import org.openjdk.jmh.annotations.Scope;
import org.openjdk.jmh.annotations.Setup;
import org.openjdk.jmh.annotations.State;
import org.openjdk.jmh.annotations.Warmup;

import java.util.concurrent.TimeUnit;

@State(Scope.Thread)
@BenchmarkMode(Mode.AverageTime)
@OutputTimeUnit(TimeUnit.NANOSECONDS)
@Warmup(iterations = 5, time = 1)
@Fork(value = 1)
@Measurement(iterations = 5, time = 1)
public class StringFirstCharBenchmark {

    private String source;

    @Setup
    public void init() {
        source = "MALE";
    }

    @Benchmark
    public String substring() {
        return source.substring(0, 1);
    }

    @Benchmark
    public String indexOf() {
        return String.valueOf(source.indexOf(0));
    }
}

Results:

+----------------------------------------------------------------------+
| Benchmark                           Mode  Cnt   Score   Error  Units |
+----------------------------------------------------------------------+
| StringFirstCharBenchmark.indexOf    avgt    5  23.777 ? 5.788  ns/op |
| StringFirstCharBenchmark.substring  avgt    5  11.305 ? 1.411  ns/op |
+----------------------------------------------------------------------+

Call jQuery Ajax Request Each X Minutes

A bit late but I used jQuery ajax method. But I did not want to send a request every second if I haven't got the response back from the last request, so I did this.

function request(){
            if(response == true){
                // This makes it unable to send a new request 
                // unless you get response from last request
                response = false;
                var req = $.ajax({
                    type:"post",
                    url:"request-handler.php",
                    data:{data:"Hello World"}
                });

                req.done(function(){
                    console.log("Request successful!");

                    // This makes it able to send new request on the next interval
                    response = true;
                });
            }

            setTimeout(request(),1000);
        }

        request();

Transparent color of Bootstrap-3 Navbar

  1. Go to http://px64.net/
  2. mess around with opacity, add your image or choose color.
  3. copy either html or css(css is easier) the site spits out.
  4. Select your element aka the navbar.

  5. .navbar{ background-image:url(link that the site provides); background-repeat:repeat;

  6. Enjoy.

What is Python used for?

Python is a dynamic, strongly typed, object oriented, multipurpose programming language, designed to be quick (to learn, to use, and to understand), and to enforce a clean and uniform syntax.

  1. Python is dynamically typed: it means that you don't declare a type (e.g. 'integer') for a variable name, and then assign something of that type (and only that type). Instead, you have variable names, and you bind them to entities whose type stays with the entity itself. a = 5 makes the variable name a to refer to the integer 5. Later, a = "hello" makes the variable name a to refer to a string containing "hello". Static typed languages would have you declare int a and then a = 5, but assigning a = "hello" would have been a compile time error. On one hand, this makes everything more unpredictable (you don't know what a refers to). On the other hand, it makes very easy to achieve some results a static typed languages makes very difficult.
  2. Python is strongly typed. It means that if a = "5" (the string whose value is '5') will remain a string, and never coerced to a number if the context requires so. Every type conversion in python must be done explicitly. This is different from, for example, Perl or Javascript, where you have weak typing, and can write things like "hello" + 5 to get "hello5".
  3. Python is object oriented, with class-based inheritance. Everything is an object (including classes, functions, modules, etc), in the sense that they can be passed around as arguments, have methods and attributes, and so on.
  4. Python is multipurpose: it is not specialised to a specific target of users (like R for statistics, or PHP for web programming). It is extended through modules and libraries, that hook very easily into the C programming language.
  5. Python enforces correct indentation of the code by making the indentation part of the syntax. There are no control braces in Python. Blocks of code are identified by the level of indentation. Although a big turn off for many programmers not used to this, it is precious as it gives a very uniform style and results in code that is visually pleasant to read.
  6. The code is compiled into byte code and then executed in a virtual machine. This means that precompiled code is portable between platforms.

Python can be used for any programming task, from GUI programming to web programming with everything else in between. It's quite efficient, as much of its activity is done at the C level. Python is just a layer on top of C. There are libraries for everything you can think of: game programming and openGL, GUI interfaces, web frameworks, semantic web, scientific computing...

How to send Basic Auth with axios

Hi you can do this in the following way

var username = '';
var password = ''

const token = `${username}:${password}`;
const encodedToken = Buffer.from(token).toString('base64');
const session_url = 'http://api_address/api/session_endpoint';

var config = {
  method: 'get',
  url: session_url,
  headers: { 'Authorization': 'Basic '+ encodedToken }
};

axios(config)
.then(function (response) {
  console.log(JSON.stringify(response.data));
})
.catch(function (error) {
  console.log(error);
});

How to get the size of a varchar[n] field in one SQL statement?

For SQL Server (2008 and above):

SELECT COLUMNPROPERTY(OBJECT_ID('mytable'), 'Remarks', 'PRECISION');

COLUMNPROPERTY returns information for a column or parameter (id, column/parameter, property). The PRECISION property returns the length of the data type of the column or parameter.

COLUMNPROPERTY documentation

Find html label associated with a given input

If you are using jQuery you can do something like this

$('label[for="foo"]').hide ();

If you aren't using jQuery you'll have to search for the label. Here is a function that takes the element as an argument and returns the associated label

function findLableForControl(el) {
   var idVal = el.id;
   labels = document.getElementsByTagName('label');
   for( var i = 0; i < labels.length; i++ ) {
      if (labels[i].htmlFor == idVal)
           return labels[i];
   }
}

When to use cla(), clf() or close() for clearing a plot in matplotlib?

plt.cla() means clear current axis

plt.clf() means clear current figure

also, there's plt.gca() (get current axis) and plt.gcf() (get current figure)

Read more here: Matplotlib, Pyplot, Pylab etc: What's the difference between these and when to use each?

How do I create a foreign key in SQL Server?

Like you, I don't usually create foreign keys by hand, but if for some reason I need the script to do so I usually create it using ms sql server management studio and before saving then changes, I select Table Designer | Generate Change Script

How to read an external local JSON file in JavaScript?

  1. First, create a json file. In this example my file is words.json

_x000D_
_x000D_
[{"name":"ay","id":"533"},_x000D_
{"name":"kiy","id":"33"},_x000D_
{"name":"iy","id":"33"},_x000D_
{"name":"iy","id":"3"},_x000D_
{"name":"kiy","id":"35"},_x000D_
{"name":"kiy","id":"34"}]
_x000D_
_x000D_
_x000D_

  1. And here is my code i.e,node.js. Note the 'utf8' argument to readFileSync: this makes it return not a Buffer (although JSON.parse can handle it), but a string. I am creating a server to see the result...

_x000D_
_x000D_
var fs=require('fs');_x000D_
var data=fs.readFileSync('words.json', 'utf8');_x000D_
var words=JSON.parse(data);_x000D_
var bodyparser=require('body-parser');_x000D_
console.log(words);_x000D_
var express=require('express');_x000D_
_x000D_
var app=express();_x000D_
_x000D_
var server=app.listen(3030,listening);_x000D_
_x000D_
function listening(){_x000D_
console.log("listening..");_x000D_
}_x000D_
app.use(express.static('website'));_x000D_
app.use(bodyparser.urlencoded({extended:false}));_x000D_
app.use(bodyparser.json());
_x000D_
_x000D_
_x000D_

  1. When you want to read particular id details you can mention the code as..

_x000D_
_x000D_
 app.get('/get/:id',function(req,res){_x000D_
 _x000D_
var i;_x000D_
   _x000D_
 for(i=0;i<words.length;++i)_x000D_
 {_x000D_
 if(words[i].id==req.params.id){_x000D_
 res.send(words[i]);_x000D_
 }_x000D_
}_x000D_
console.log("success");_x000D_
   _x000D_
});
_x000D_
_x000D_
_x000D_

  1. When you entered in url as localhost:3030/get/33 it will give the details related to that id....and you read by name also. My json file has simillar names with this code you can get one name details....and it didn't print all the simillar names

_x000D_
_x000D_
 app.get('/get/:name',function(req,res){_x000D_
 _x000D_
var i;_x000D_
   _x000D_
 for(i=0;i<words.length;++i)_x000D_
 {_x000D_
 if(words[i].id==req.params.name){_x000D_
 res.send(words[i]);_x000D_
 }_x000D_
}_x000D_
console.log("success");_x000D_
   _x000D_
});
_x000D_
_x000D_
_x000D_

  1. And if you want to read simillar name details, you can use this code.

_x000D_
_x000D_
app.get('/get/name/:name',function(req,res){_x000D_
word = words.filter(function(val){_x000D_
  return val.name === req.params.name;_x000D_
});_x000D_
res.send(word);_x000D_
    _x000D_
 console.log("success");_x000D_
   _x000D_
});
_x000D_
_x000D_
_x000D_

  1. If you want to read all the information in the file then use this code below.

_x000D_
_x000D_
app.get('/all',sendAll);_x000D_
 _x000D_
 function sendAll(request,response){_x000D_
 response.send(words);_x000D_
_x000D_
 }_x000D_
 
_x000D_
_x000D_
_x000D_

SHA512 vs. Blowfish and Bcrypt

It should suffice to say whether bcrypt or SHA-512 (in the context of an appropriate algorithm like PBKDF2) is good enough. And the answer is yes, either algorithm is secure enough that a breach will occur through an implementation flaw, not cryptanalysis.

If you insist on knowing which is "better", SHA-512 has had in-depth reviews by NIST and others. It's good, but flaws have been recognized that, while not exploitable now, have led to the the SHA-3 competition for new hash algorithms. Also, keep in mind that the study of hash algorithms is "newer" than that of ciphers, and cryptographers are still learning about them.

Even though bcrypt as a whole hasn't had as much scrutiny as Blowfish itself, I believe that being based on a cipher with a well-understood structure gives it some inherent security that hash-based authentication lacks. Also, it is easier to use common GPUs as a tool for attacking SHA-2–based hashes; because of its memory requirements, optimizing bcrypt requires more specialized hardware like FPGA with some on-board RAM.


Note: bcrypt is an algorithm that uses Blowfish internally. It is not an encryption algorithm itself. It is used to irreversibly obscure passwords, just as hash functions are used to do a "one-way hash".

Cryptographic hash algorithms are designed to be impossible to reverse. In other words, given only the output of a hash function, it should take "forever" to find a message that will produce the same hash output. In fact, it should be computationally infeasible to find any two messages that produce the same hash value. Unlike a cipher, hash functions aren't parameterized with a key; the same input will always produce the same output.

If someone provides a password that hashes to the value stored in the password table, they are authenticated. In particular, because of the irreversibility of the hash function, it's assumed that the user isn't an attacker that got hold of the hash and reversed it to find a working password.

Now consider bcrypt. It uses Blowfish to encrypt a magic string, using a key "derived" from the password. Later, when a user enters a password, the key is derived again, and if the ciphertext produced by encrypting with that key matches the stored ciphertext, the user is authenticated. The ciphertext is stored in the "password" table, but the derived key is never stored.

In order to break the cryptography here, an attacker would have to recover the key from the ciphertext. This is called a "known-plaintext" attack, since the attack knows the magic string that has been encrypted, but not the key used. Blowfish has been studied extensively, and no attacks are yet known that would allow an attacker to find the key with a single known plaintext.

So, just like irreversible algorithms based cryptographic digests, bcrypt produces an irreversible output, from a password, salt, and cost factor. Its strength lies in Blowfish's resistance to known plaintext attacks, which is analogous to a "first pre-image attack" on a digest algorithm. Since it can be used in place of a hash algorithm to protect passwords, bcrypt is confusingly referred to as a "hash" algorithm itself.

Assuming that rainbow tables have been thwarted by proper use of salt, any truly irreversible function reduces the attacker to trial-and-error. And the rate that the attacker can make trials is determined by the speed of that irreversible "hash" algorithm. If a single iteration of a hash function is used, an attacker can make millions of trials per second using equipment that costs on the order of $1000, testing all passwords up to 8 characters long in a few months.

If however, the digest output is "fed back" thousands of times, it will take hundreds of years to test the same set of passwords on that hardware. Bcrypt achieves the same "key strengthening" effect by iterating inside its key derivation routine, and a proper hash-based method like PBKDF2 does the same thing; in this respect, the two methods are similar.

So, my recommendation of bcrypt stems from the assumptions 1) that a Blowfish has had a similar level of scrutiny as the SHA-2 family of hash functions, and 2) that cryptanalytic methods for ciphers are better developed than those for hash functions.

Execute Shell Script after post build in Jenkins

You'd have to set up the post-build shell script as a separate Jenkins job and trigger it as a post-build step. It looks like you will need to use the Parameterized Trigger Plugin as the standard "Build other projects" option only works if your triggering build is successful.

Reload parent window from child window

parent.location.reload();

This should work.

What is "Advanced" SQL?

I think it's best highlighted with an example. If you feel you could write the following SQL statement quickly with little/no reference material, then I'd guess that you probably meet their Advanced SQL requirement:

DECLARE @date DATETIME
SELECT @date = '10/31/09'

SELECT
      t1.EmpName,
      t1.Region,
      t1.TourStartDate,
      t1.TourEndDate,
      t1.FOrdDate,
      FOrdType  = MAX(CASE WHEN o.OrderDate = t1.FOrdDate THEN o.OrderType  ELSE NULL END),
      FOrdTotal = MAX(CASE WHEN o.OrderDate = t1.FOrdDate THEN o.OrderTotal ELSE NULL END),
      t1.LOrdDate,
      LOrdType  = MAX(CASE WHEN o.OrderDate = t1.LOrdDate THEN o.OrderType  ELSE NULL END),
      LOrdTotal = MAX(CASE WHEN o.OrderDate = t1.LOrdDate THEN o.OrderTotal ELSE NULL END)
  FROM 
      (--Derived table t1 returns the tourdates, and the order dates
      SELECT
            e.EmpId,
            e.EmpName,
            et.Region,
            et.TourStartDate,
            et.TourEndDate,
            FOrdDate = MIN(o.OrderDate),
            LOrdDate = MAX(o.OrderDate)
        FROM #Employees e INNER JOIN #EmpTours et
          ON e.EmpId = et.EmpId INNER JOIN #Orders o
          ON e.EmpId = o.EmpId
       WHERE et.TourStartDate <= @date
         AND (et.TourEndDate > = @date OR et.TourEndDate IS NULL)
         AND o.OrderDate BETWEEN et.TourStartDate AND @date
       GROUP BY e.EmpId,e.EmpName,et.Region,et.TourStartDate,et.TourEndDate
      ) t1 INNER JOIN #Orders o
    ON t1.EmpId = o.EmpId
   AND (t1.FOrdDate = o.OrderDate OR t1.LOrdDate = o.OrderDate)
 GROUP BY t1.EmpName,t1.Region,t1.TourStartDate,t1.TourEndDate,t1.FOrdDate,t1.LOrdDate

(source of query)

And to be honest, that's a relatively simple query - just some inner joins and a subquery, along with a few common keywords (max, min, case).

What does template <unsigned int N> mean?

It's perfectly possible to template a class on an integer rather than a type. We can assign the templated value to a variable, or otherwise manipulate it in a way we might with any other integer literal:

unsigned int x = N;

In fact, we can create algorithms which evaluate at compile time (from Wikipedia):

template <int N>
struct Factorial 
{
     enum { value = N * Factorial<N - 1>::value };
};

template <>
struct Factorial<0> 
{
    enum { value = 1 };
};

// Factorial<4>::value == 24
// Factorial<0>::value == 1
void foo()
{
    int x = Factorial<4>::value; // == 24
    int y = Factorial<0>::value; // == 1
}

How do I use a regular expression to match any string, but at least 3 characters?

Try this .{3,} this will match any characher except new line (\n)

Insert null/empty value in sql datetime column by default

  1. define it like your_field DATETIME NULL DEFAULT NULL
  2. dont insert a blank string, insert a NULL INSERT INTO x(your_field)VALUES(NULL)

How do I disable form fields using CSS?

I am always using:

input.disabled {
    pointer-events:none;
    color:#AAA;
    background:#F5F5F5;
}

and then applying the css class to the input field:

<input class="disabled" type="text" value="90" name="myinput" id="myinput" />

Executing a command stored in a variable from PowerShell

Try invoking your command with Invoke-Expression:

Invoke-Expression $cmd1

Here is a working example on my machine:

$cmd = "& 'C:\Program Files\7-zip\7z.exe' a -tzip c:\temp\test.zip c:\temp\test.txt"
Invoke-Expression $cmd

iex is an alias for Invoke-Expression so you could do:

iex $cmd1

For a full list : Visit https://ss64.com/ps/ for more Powershell stuff.

Good Luck...

Android Material and appcompat Manifest merger failed

Its all about the library versions compatibility

I was facing this strange bug couple of 2 hours. I resolved this error by doing these steps

hange your build.gradle dependencies into

  implementation 'com.google.android.gms:play-services-maps:17.0.0'

to

  implementation 'com.google.android.gms:play-services-maps:15.0.0'

How do I disable a Button in Flutter?

For a specific and limited number of widgets, wrapping them in a widget IgnorePointer does exactly this: when its ignoring property is set to true, the sub-widget (actually, the entire subtree) is not clickable.

IgnorePointer(
    ignoring: true, // or false
    child: RaisedButton(
        onPressed: _logInWithFacebook,
        child: Text("Facebook sign-in"),
        ),
),

Otherwise, if you intend to disable an entire subtree, look into AbsorbPointer().

Convert seconds to hh:mm:ss in Python

If you use divmod, you are immune to different flavors of integer division:

# show time strings for 3800 seconds

# easy way to get mm:ss
print "%02d:%02d" % divmod(3800, 60)

# easy way to get hh:mm:ss
print "%02d:%02d:%02d" % \
    reduce(lambda ll,b : divmod(ll[0],b) + ll[1:],
        [(3800,),60,60])


# function to convert floating point number of seconds to
# hh:mm:ss.sss
def secondsToStr(t):
    return "%02d:%02d:%02d.%03d" % \
        reduce(lambda ll,b : divmod(ll[0],b) + ll[1:],
            [(round(t*1000),),1000,60,60])

print secondsToStr(3800.123)

Prints:

63:20
01:03:20
01:03:20.123

Breaking up long strings on multiple lines in Ruby without stripping newlines

I had this problem when I try to write a very long url, the following works.

image_url = %w(
    http://minio.127.0.0.1.xip.io:9000/
    bucket29/docs/b7cfab0e-0119-452c-b262-1b78e3fccf38/
    28ed3774-b234-4de2-9a11-7d657707f79c?
    X-Amz-Algorithm=AWS4-HMAC-SHA256&
    X-Amz-Credential=ABABABABABABABABA
    %2Fus-east-1%2Fs3%2Faws4_request&
    X-Amz-Date=20170702T000940Z&
    X-Amz-Expires=3600&X-Amz-SignedHeaders=host&
    X-Amz-Signature=ABABABABABABABABABABAB
    ABABABABABABABABABABABABABABABABABABA
).join

Note, there must not be any newlines, white spaces when the url string is formed. If you want newlines, then use HEREDOC.

Here you have indentation for readability, ease of modification, without the fiddly quotes and backslashes on every line. The cost of joining the strings should be negligible.

How to fix "Only one expression can be specified in the select list when the subquery is not introduced with EXISTS" error?

Try this one -

"SELECT 
       ID, Salt, password, BannedEndDate
     , (
          SELECT COUNT(1)
          FROM dbo.LoginFails l
          WHERE l.UserName = u.UserName
               AND IP = '" + Request.ServerVariables["REMOTE_ADDR"] + "'
      ) AS cnt
FROM dbo.Users u
WHERE u.UserName = '" + LoginModel.Username + "'"

How do I make an auto increment integer field in Django?

You can use default primary key (id) which auto increaments.

Note: When you use first design i.e. use default field (id) as a primary key, initialize object by mentioning column names. e.g.

class User(models.Model):
    user_name = models.CharField(max_length = 100)

then initialize,

user = User(user_name="XYZ")

if you initialize in following way,

user = User("XYZ")

then python will try to set id = "XYZ" which will give you error on data type.

How to change the Content of a <textarea> with JavaScript

If it's jQuery...

$("#myText").val('');

or

document.getElementById('myText').value = '';

Reference: Text Area Object

C++ error 'Undefined reference to Class::Function()'

What are you using to compile this? If there's an undefined reference error, usually it's because the .o file (which gets created from the .cpp file) doesn't exist and your compiler/build system is not able to link it.

Also, in your card.cpp, the function should be Card::Card() instead of void Card. The Card:: is scoping; it means that your Card() function is a member of the Card class (which it obviously is, since it's the constructor for that class). Without this, void Card is just a free function. Similarly,

void Card(Card::Rank rank, Card::Suit suit)

should be

Card::Card(Card::Rank rank, Card::Suit suit)

Also, in deck.cpp, you are saying #include "Deck.h" even though you referred to it as deck.h. The includes are case sensitive.

Accessing localhost of PC from USB connected Android mobile device

I did this on a windows computer and it worked perfectly!

Turn on USB Tethering in your mobile. Type ipconfig in the command prompt in your computer and find the ipv4 for "ethernet adapter local area connection x" (mostly the first one) Now go to your mobile browser, type that ipv4 with the port number of your web application. eg:- 192.168.40.142:1342

It worked with those simple steps!

How to create empty folder in java?

Looks file you use the .mkdirs() method on a File object: http://www.roseindia.net/java/beginners/java-create-directory.shtml

// Create a directory; all non-existent ancestor directories are
// automatically created
success = (new File("../potentially/long/pathname/without/all/dirs")).mkdirs();
if (!success) {
    // Directory creation failed
}

Ternary operator (?:) in Bash

[ $b == 5 ] && { a=$c; true; } || a=$d

This will avoid executing the part after || by accident when the code between && and || fails.

How to use a global array in C#?

Your class shoud look something like this:

class Something {     int[] array; //global array, replace type of course     void function1() {        array = new int[10]; //let say you declare it here that will be 10 integers in size     }     void function2() {        array[0] = 12; //assing value at index 0 to 12.     } } 

That way you array will be accessible in both functions. However, you must be careful with global stuff, as you can quickly overwrite something.

How to change the background color of the options menu?

If you want to set an arbitrary color, this seem to work rather well for androidx. Tested on KitKat and Pie. Put this into your AppCompatActivity:

@Override public View onCreateView(View parent, String name, Context context, AttributeSet attrs) {
    if (name.equals("androidx.appcompat.view.menu.ListMenuItemView") &&
            parent.getParent() instanceof FrameLayout) {
            ((View) parent.getParent()).setBackgroundColor(yourFancyColor);
    }
    return super.onCreateView(parent, name, context, attrs);
}

This sets the color of android.widget.PopupWindow$PopupBackgroundView, which, as you might have guessed, draws the background color. There's no overdraw and you can use semi-transparent colors as well.

Removing rounded corners from a <select> element in Chrome/Webkit

Just my solution with dropdown image (inline svg)

select.form-control {
    -webkit-appearance: none;
    -webkit-border-radius: 0px;
    background-image: url("data:image/svg+xml;utf8,<svg version='1.1' xmlns='http://www.w3.org/2000/svg' xmlns:xlink='http://www.w3.org/1999/xlink' width='24' height='24' viewBox='0 0 24 24'><path fill='%23444' d='M7.406 7.828l4.594 4.594 4.594-4.594 1.406 1.406-6 6-6-6z'></path></svg>");
    background-position: 100% 50%;
    background-repeat: no-repeat;
}

I'm using bootstrap that's why I used select.form-control
You can use select{ or select.your-custom-class{ instead.

Converting a char to ASCII?

Uhm, what's wrong with this:

#include <iostream>

using namespace std;

int main(int, char **)
{
    char c = 'A';

    int x = c; // Look ma! No cast!

    cout << "The character '" << c << "' has an ASCII code of " << x << endl;

    return 0;
}

Revert to Eclipse default settings

Just remove .metadata from your eclipse workspace You can find it C:\Users\username\workspace

XML Schema (XSD) validation tool?

http://www.xmlvalidation.com/

(Be sure to check the " Validate against external XML schema" Box)

What does "#pragma comment" mean?

I've always called them "compiler directives." They direct the compiler to do things, branching, including libs like shown above, disabling specific errors etc., during the compilation phase.

Compiler companies usually create their own extensions to facilitate their features. For example, (I believe) Microsoft started the "#pragma once" deal and it was only in MS products, now I'm not so sure.

Pragma Directives It includes "#pragma comment" in the table you'll see.

HTH

I suspect GCC, for example, has their own set of #pragma's.

Read a javascript cookie by name

Here is an API which was written to smooth over the nasty browser cookie "API"

http://code.google.com/p/cookies/

foreach loop in angularjs

you have to use nested angular.forEach loops for JSON as shown below:

 var values = [
        {
            "name":"Thomas",
            "password":"thomas"
        },
        { 
            "name":"linda",
            "password":"linda"
        }];

    angular.forEach(values,function(value,key){
        angular.forEach(value,function(v1,k1){//this is nested angular.forEach loop
            console.log(k1+":"+v1);
        });
    });

SaveFileDialog setting default path and file type?

The SaveFileDialog control won't do any saving at all. All it does is providing you a convenient interface to actually display Windows' default file save dialog.

  1. Set the property InitialDirectory to the drive you'd like it to show some other default. Just think of other computers that might have a different layout. By default windows will save the directory used the last time and present it again.

  2. That is handled outside the control. You'll have to check the dialog's results and then do the saving yourself (e.g. write a text or binary file).

Just as a quick example (there are alternative ways to do it). savefile is a control of type SaveFileDialog

SaveFileDialog savefile = new SaveFileDialog(); 
// set a default file name
savefile.FileName = "unknown.txt";
// set filters - this can be done in properties as well
savefile.Filter = "Text files (*.txt)|*.txt|All files (*.*)|*.*";

if (savefile.ShowDialog() == DialogResult.OK)
{
    using (StreamWriter sw = new StreamWriter(savefile.FileName))
        sw.WriteLine ("Hello World!");
}

Creating a zero-filled pandas data frame

Similar to @Shravan, but without the use of numpy:

  height = 10
  width = 20
  df_0 = pd.DataFrame(0, index=range(height), columns=range(width))

Then you can do whatever you want with it:

post_instantiation_fcn = lambda x: str(x)
df_ready_for_whatever = df_0.applymap(post_instantiation_fcn)

Iterate through object properties

The for...in loop represents each property in an object because it is just like a for loop. You defined propt in the for...in loop by doing:

    for(var propt in obj){
alert(propt + ': ' + obj[propt]);
}

A for...in loop iterates through the enumerable properties of an object. Whichever variable you define, or put in the for...in loop, changes each time it goes to the next property it iterates. The variable in the for...in loop iterates through the keys, but the value of it is the key's value. For example:

    for(var propt in obj) {
      console.log(propt);//logs name
      console.log(obj[propt]);//logs "Simon"
    }

You can see how the variable differs from the variable's value. In contrast, a for...of loop does the opposite.

I hope this helps.

Reshape an array in NumPy

numpy has a great tool for this task ("numpy.reshape") link to reshape documentation

a = [[ 0  1]
 [ 2  3]
 [ 4  5]
 [ 6  7]
 [ 8  9]
 [10 11]
 [12 13]
 [14 15]
 [16 17]]

`numpy.reshape(a,(3,3))`

you can also use the "-1" trick

`a = a.reshape(-1,3)`

the "-1" is a wild card that will let the numpy algorithm decide on the number to input when the second dimension is 3

so yes.. this would also work: a = a.reshape(3,-1)

and this: a = a.reshape(-1,2) would do nothing

and this: a = a.reshape(-1,9) would change the shape to (2,9)

comma separated string of selected values in mysql

Check this

SELECT GROUP_CONCAT(id)  FROM table_level where parent_id=4 group by parent_id;

Which version of Python do I have installed?

Mostly usage commands:

python -version

Or

python -V

'POCO' definition

In Java land typically "PO" means "plain old". The rest can be tricky, so I'm guessing that your example (in the context of Java) is "plain old class object".

some other examples

  • POJO (plain old java object)
  • POJI (plain old java interface)

Can't build create-react-app project with custom PUBLIC_URL

This problem becomes apparent when you try to host a react app in github pages.

How I fixed this,

In in my main application file, called app.tsx, where I include the router. I set the basename, eg, <BrowserRouter basename="/Seans-TypeScript-ReactJS-Redux-Boilerplate/">

Note that it is a relative url, this completely simplifies the ability to run locally and hosted. The basename value, matches the repository title on GitHub. This is the path that GitHub pages will auto create.

That is all I needed to do.

See working example hosted on GitHub pages at

https://sean-bradley.github.io/Seans-TypeScript-ReactJS-Redux-Boilerplate/

Change the borderColor of the TextBox

With PictureBox1
    .Visible = False
    .Width = TextBox1.Width + 4
    .Height = TextBox1.Height + 4
    .Left = TextBox1.Left - 2
    .Top = TextBox1.Top - 2
    .SendToBack()
    .Visible = True
End With

PHP, pass array through POST

You could put it in the session:

session_start();
$_SESSION['array_name'] = $array_name;

Or if you want to send it via a form you can serialize it:

<input type='hidden' name='input_name' value="<?php echo htmlentities(serialize($array_name)); ?>" />

$passed_array = unserialize($_POST['input_name']);

Note that to work with serialized arrays, you need to use POST as the form's transmission method, as GET has a size limit somewhere around 1024 characters.

I'd use sessions wherever possible.

Cast object to interface in TypeScript

Here's another way to force a type-cast even between incompatible types and interfaces where TS compiler normally complains:

export function forceCast<T>(input: any): T {

  // ... do runtime checks here

  // @ts-ignore <-- forces TS compiler to compile this as-is
  return input;
}

Then you can use it to force cast objects to a certain type:

import { forceCast } from './forceCast';

const randomObject: any = {};
const typedObject = forceCast<IToDoDto>(randomObject);

Note that I left out the part you are supposed to do runtime checks before casting for the sake of reducing complexity. What I do in my project is compiling all my .d.ts interface files into JSON schemas and using ajv to validate in runtime.

How do I find the mime-type of a file with php?

According to the php manual, the finfo-file function is best way to do this. However, you will need to install the FileInfo PECL extension.

If the extension is not an option, you can use the outdated mime_content_type function.

How to use shared memory with Linux in C

try this code sample, I tested it, source: http://www.makelinux.net/alp/035

#include <stdio.h> 
#include <sys/shm.h> 
#include <sys/stat.h> 

int main () 
{
  int segment_id; 
  char* shared_memory; 
  struct shmid_ds shmbuffer; 
  int segment_size; 
  const int shared_segment_size = 0x6400; 

  /* Allocate a shared memory segment.  */ 
  segment_id = shmget (IPC_PRIVATE, shared_segment_size, 
                 IPC_CREAT | IPC_EXCL | S_IRUSR | S_IWUSR); 
  /* Attach the shared memory segment.  */ 
  shared_memory = (char*) shmat (segment_id, 0, 0); 
  printf ("shared memory attached at address %p\n", shared_memory); 
  /* Determine the segment's size. */ 
  shmctl (segment_id, IPC_STAT, &shmbuffer); 
  segment_size  =               shmbuffer.shm_segsz; 
  printf ("segment size: %d\n", segment_size); 
  /* Write a string to the shared memory segment.  */ 
  sprintf (shared_memory, "Hello, world."); 
  /* Detach the shared memory segment.  */ 
  shmdt (shared_memory); 

  /* Reattach the shared memory segment, at a different address.  */ 
  shared_memory = (char*) shmat (segment_id, (void*) 0x5000000, 0); 
  printf ("shared memory reattached at address %p\n", shared_memory); 
  /* Print out the string from shared memory.  */ 
  printf ("%s\n", shared_memory); 
  /* Detach the shared memory segment.  */ 
  shmdt (shared_memory); 

  /* Deallocate the shared memory segment.  */ 
  shmctl (segment_id, IPC_RMID, 0); 

  return 0; 
} 

Scroll part of content in fixed position container

Actually this is better way to do that. If height: 100% is used, the content goes off the border, but when it is 95% everything is in order:

div#scrollable {
    overflow-y: scroll;
    height: 95%;
}

Why use @Scripts.Render("~/bundles/jquery")

You can also use:

@Scripts.RenderFormat("<script type=\"text/javascript\" src=\"{0}\"></script>", "~/bundles/mybundle")

To specify the format of your output in a scenario where you need to use Charset, Type, etc.

Android App Not Install. An existing package by the same name with a conflicting signature is already installed

I had an issue where both debug and release build won't install on devices I used for debugging. The same msg would appear when trying to install the new version. The only workaround was to uninstall the current version and install the new one.

It looks like Android studio marks the apk it installs so that installation using the package managers would distinguish between version installed for debugging and versions downloaded from Google play or other external sources (this never happened to me when using eclipse).

How can I use NSError in my iPhone App?

Well it's a little bit out of question scope but in case you don't have an option for NSError you can always display the Low level error:

 NSLog(@"Error = %@ ",[NSString stringWithUTF8String:strerror(errno)]);

Using wget to recursively fetch a directory with arbitrary files in it

The following option seems to be the perfect combination when dealing with recursive download:

wget -nd -np -P /dest/dir --recursive http://url/dir1/dir2

Relevant snippets from man pages for convenience:

   -nd
   --no-directories
       Do not create a hierarchy of directories when retrieving recursively.  With this option turned on, all files will get saved to the current directory, without clobbering (if a name shows up more than once, the
       filenames will get extensions .n).


   -np
   --no-parent
       Do not ever ascend to the parent directory when retrieving recursively.  This is a useful option, since it guarantees that only the files below a certain hierarchy will be downloaded.

How to update specific key's value in an associative array in PHP?

foreach($data as $value)
{
    $value["transaction_date"] = date('d/m/Y',$value["transaction_date"]);
}
return $data;

What properties does @Column columnDefinition make redundant?

columnDefinition will override the sql DDL generated by hibernate for this particular column, it is non portable and depends on what database you are using. You can use it to specify nullable, length, precision, scale... ect.

Java Try and Catch IOException Problem

Your countLines(String filename) method throws IOException.

You can't use it in a member declaration. You'll need to perform the operation in a main(String[] args) method.

Your main(String[] args) method will get the IOException thrown to it by countLines and it will need to handle or declare it.

Try this to just throw the IOException from main

public class MyClass {
  private int lineCount;
  public static void main(String[] args) throws IOException {
    lineCount = LineCounter.countLines(sFileName);
  }
}

or this to handle it and wrap it in an unchecked IllegalArgumentException:

public class MyClass {
  private int lineCount;
  private String sFileName  = "myfile";
  public static void main(String[] args) throws IOException {
    try {
      lineCount = LineCounter.countLines(sFileName);
     } catch (IOException e) {
       throw new IllegalArgumentException("Unable to load " + sFileName, e);
     }
  }
}

Clear form after submission with jQuery

You can reset your form with:

$("#myform")[0].reset();

Laravel - display a PDF file in storage without forcing download?

Ben Swinburne answer was so helpful.

The code below is for those who have their PDF file in database like me.

$pdf = DB::table('exportfiles')->select('pdf')->where('user_id', $user_id)->first();

return Response::make(base64_decode( $pdf->pdf), 200, [
    'Content-Type' => 'application/pdf',
    'Content-Disposition' => 'inline; filename="'.$filename.'"',
]);

Where $pdf->pdf is the file column in database.

PHP - Merging two arrays into one array (also Remove Duplicates)

Merging two array will not remove the duplicate you can try the below example to get unique from two array

$a1=array("a"=>"red","b"=>"green","c"=>"blue","d"=>"yellow");
$a2=array("e"=>"red","f"=>"green","g"=>"blue");

$result=array_diff($a1,$a2);
print_r($result);

What is the difference between ng-if and ng-show/ng-hide

ng-show and ng-hide work in opposite way. But the difference between ng-hide or ng-show with ng-if is,if we use ng-if then element will created in the dom but with ng-hide/ng-show element will be hidden completely.

ng-show=true/ng-hide=false:
Element will be displayed

ng-show=false/ng-hide=true:
element will be hidden

ng-if =true
element will be created

ng-if= false
element will be created in the dom. 

PHP XML how to output nice format

Tried all the answers but none worked. Maybe it's because I'm appending and removing childs before saving the XML. After a lot of googling found this comment in the php documentation. I only had to reload the resulting XML to make it work.

$outXML = $xml->saveXML(); 
$xml = new DOMDocument(); 
$xml->preserveWhiteSpace = false; 
$xml->formatOutput = true; 
$xml->loadXML($outXML); 
$outXML = $xml->saveXML(); 

How to insert text at beginning of a multi-line selection in vi/Vim

Another way that might be easier for newcomers:

 some¦
 code
 here

Place the cursor on the first line, e.g. by

gg

and type the following to get into insert mode and add your text:

I / / Space

 // ¦some
 code
 here

Press Esc to get back to command mode and use the digraph:

j . j .

 // some
 // code
 //¦here

j is a motion command to go down one line and . repeats the last editing command you made.

How to POST URL in data of a curl request

I don't think it's necessary to use semi-quotes around the variables, try:

curl -XPOST 'http://localhost/Service' -d "path=%2fxyz%2fpqr%2ftest%2f&fileName=1.doc"

%2f is the escape code for a /.

http://www.december.com/html/spec/esccodes.html

Also, do you need to specify a port? ( just checking :) )

How can I merge two MySQL tables?

If you need to do it manually, one time:

First, merge in a temporary table, with something like:

create table MERGED as select * from table 1 UNION select * from table 2

Then, identify the primary key constraints with something like

SELECT COUNT(*), PK from MERGED GROUP BY PK HAVING COUNT(*) > 1

Where PK is the primary key field...

Solve the duplicates.

Rename the table.

[edited - removed brackets in the UNION query, which was causing the error in the comment below]

How can I convert a Timestamp into either Date or DateTime object?

java.time

Modern answer: use java.time, the modern Java date and time API, for your date and time work. Back in 2011 it was right to use the Timestamp class, but since JDBC 4.2 it is no longer advised.

For your work we need a time zone and a couple of formatters. We may as well declare them static:

static ZoneId zone = ZoneId.of("America/Marigot");
static DateTimeFormatter dateFormatter = DateTimeFormatter.ofPattern("MM/dd/uuuu");
static DateTimeFormatter timeFormatter = DateTimeFormatter.ofPattern("HH:mm xx");

Now the code could be for example:

    while(resultSet.next()) {
        ZonedDateTime dtStart = resultSet.getObject("dtStart", OffsetDateTime.class)
                 .atZoneSameInstant(zone);

        // I would like to then have the date and time
        // converted into the formats mentioned...
        String dateFormatted = dtStart.format(dateFormatter);
        String timeFormatted = dtStart.format(timeFormatter);
        System.out.format("Date: %s; time: %s%n", dateFormatted, timeFormatted);
    }

Example output (using the time your question was asked):

Date: 09/20/2011; time: 18:13 -0400

In your database timestamp with time zone is recommended for timestamps. If this is what you’ve got, retrieve an OffsetDateTime as I am doing in the code. I am also converting the retrieved value to the user’s time zone before formatting date and time separately. As time zone I supplied America/Marigot as an example, please supply your own. You may also leave out the time zone conversion if you don’t want any, of course.

If the datatype in SQL is a mere timestamp without time zone, retrieve a LocalDateTime instead. For example:

        ZonedDateTime dtStart = resultSet.getObject("dtStart", LocalDateTime.class)
                 .atZone(zone);

No matter the details I trust you to do similarly for dtEnd.

I wasn’t sure what you meant by the xx in HH:MM xx. I just left it in the format pattern string, which yields the UTC offset in hours and minutes without colon.

Link: Oracle tutorial: Date Time explaining how to use java.time.

For each row return the column name of the largest value

If you're interested in a data.table solution, here's one. It's a bit tricky since you prefer to get the id for the first maximum. It's much easier if you'd rather want the last maximum. Nevertheless, it's not that complicated and it's fast!

Here I've generated data of your dimensions (26746 * 18).

Data

set.seed(45)
DF <- data.frame(matrix(sample(10, 26746*18, TRUE), ncol=18))

data.table answer:

require(data.table)
DT <- data.table(value=unlist(DF, use.names=FALSE), 
            colid = 1:nrow(DF), rowid = rep(names(DF), each=nrow(DF)))
setkey(DT, colid, value)
t1 <- DT[J(unique(colid), DT[J(unique(colid)), value, mult="last"]), rowid, mult="first"]

Benchmarking:

# data.table solution
system.time({
DT <- data.table(value=unlist(DF, use.names=FALSE), 
            colid = 1:nrow(DF), rowid = rep(names(DF), each=nrow(DF)))
setkey(DT, colid, value)
t1 <- DT[J(unique(colid), DT[J(unique(colid)), value, mult="last"]), rowid, mult="first"]
})
#   user  system elapsed 
#  0.174   0.029   0.227 

# apply solution from @thelatemail
system.time(t2 <- colnames(DF)[apply(DF,1,which.max)])
#   user  system elapsed 
#  2.322   0.036   2.602 

identical(t1, t2)
# [1] TRUE

It's about 11 times faster on data of these dimensions, and data.table scales pretty well too.


Edit: if any of the max ids is okay, then:

DT <- data.table(value=unlist(DF, use.names=FALSE), 
            colid = 1:nrow(DF), rowid = rep(names(DF), each=nrow(DF)))
setkey(DT, colid, value)
t1 <- DT[J(unique(colid)), rowid, mult="last"]

Python - How do you run a .py file?

Since you seem to be on windows you can do this so python <filename.py>. Check that python's bin folder is in your PATH, or you can do c:\python23\bin\python <filename.py>. Python is an interpretive language and so you need the interpretor to run your file, much like you need java runtime to run a jar file.

Why this line xmlns:android="http://schemas.android.com/apk/res/android" must be the first in the layout xml file?

To understand why xmlns:android=“http://schemas.android.com/apk/res/android” must be the first in the layout xml file We shall understand the components using an example

Sample::

<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:id="@+id/container" >    
</FrameLayout>

Uniform Resource Indicator(URI):

  • In computing, a uniform resource identifier (URI) is a string of characters used to identify a name of a resource.
  • Such identification enables interaction with representations of the resource over a network, typically the World Wide Web, using specific protocols.

Ex:http://schemas.android.com/apk/res/android:id is the URI here


XML Namespace:

  • XML namespaces are used for providing uniquely named elements and attributes in an XML document. xmlns:android describes the android namespace.
  • Its used like this because this is a design choice by google to handle the errors at compile time.
  • Also suppose we write our own textview widget with different features compared to android textview, android namespace helps to distinguish between our custom textview widget and android textview widget

How to determine the first and last iteration in a foreach loop?

foreach ($arquivos as $key => $item) {
   reset($arquivos);
   // FIRST AHEAD
   if ($key === key($arquivos) || $key !== end(array_keys($arquivos)))
       $pdf->cat(null, null, $key);

   // LAST
   if ($key === end(array_keys($arquivos))) {
       $pdf->cat(null, null, $key)
           ->execute();
   }
}

Get all dates between two dates in SQL Server

You can use SQL Server recursive CTE

DECLARE 
    @MinDate DATE = '2020-01-01',
    @MaxDate DATE = '2020-02-01';

WITH Dates(day) AS 
(
    SELECT CAST(@MinDate as Date) as day
    UNION ALL
    SELECT CAST(DATEADD(day, 1, day) as Date) as day
    FROM Dates
    WHERE CAST(DATEADD(day, 1, day) as Date) < @MaxDate
)
SELECT* FROM dates;

JavaScript: How to find out if the user browser is Chrome?

all answers are wrong. "Opera" and "Chrome" are same in all cases.

(edited part)

here is the right answer

if (window.chrome && window.chrome.webstore) {
    // this is Chrome
}

How do I restrict a float value to only two places after the decimal point in C?

I made this macro for rounding float numbers. Add it in your header / being of file

#define ROUNDF(f, c) (((float)((int)((f) * (c))) / (c)))

Here is an example:

float x = ROUNDF(3.141592, 100)

x equals 3.14 :)

How to increase the distance between table columns in HTML?

A better solution than selected answer would be to use border-size rather than border-spacing. The main problem with using border-spacing is that even the first column would have a spacing in the front.

For example,

_x000D_
_x000D_
table {_x000D_
  border-collapse: separate;_x000D_
  border-spacing: 80px 0;_x000D_
}_x000D_
_x000D_
td {_x000D_
  padding: 10px 0;_x000D_
}
_x000D_
<table>_x000D_
  <tr>_x000D_
    <td>First Column</td>_x000D_
    <td>Second Column</td>_x000D_
    <td>Third Column</td>_x000D_
  </tr>_x000D_
  <tr>_x000D_
    <td>1</td>_x000D_
    <td>2</td>_x000D_
    <td>3</td>_x000D_
  </tr>_x000D_
</table>
_x000D_
_x000D_
_x000D_

To avoid this use: border-left: 100px solid #FFF; and set border:0px for the first column.

For example,

_x000D_
_x000D_
td,th{_x000D_
  border-left: 100px solid #FFF;_x000D_
}_x000D_
_x000D_
 tr>td:first-child {_x000D_
   border:0px;_x000D_
 }
_x000D_
<table id="t">_x000D_
  <tr>_x000D_
    <td>Column1</td>_x000D_
    <td>Column2</td>_x000D_
    <td>Column3</td>_x000D_
  </tr>_x000D_
  <tr>_x000D_
    <td>1000</td>_x000D_
    <td>2000</td>_x000D_
    <td>3000</td>_x000D_
  </tr>_x000D_
</table>
_x000D_
_x000D_
_x000D_

Count number of rows by group using dplyr

another approach is to use the double colons:

mtcars %>% 
  dplyr::group_by(cyl, gear) %>%
  dplyr::summarise(length(gear))

Best way to define error codes/strings in Java?

Well there's certainly a better implementation of the enum solution (which is generally quite nice):

public enum Error {
  DATABASE(0, "A database error has occurred."),
  DUPLICATE_USER(1, "This user already exists.");

  private final int code;
  private final String description;

  private Error(int code, String description) {
    this.code = code;
    this.description = description;
  }

  public String getDescription() {
     return description;
  }

  public int getCode() {
     return code;
  }

  @Override
  public String toString() {
    return code + ": " + description;
  }
}

You may want to override toString() to just return the description instead - not sure. Anyway, the main point is that you don't need to override separately for each error code. Also note that I've explicitly specified the code instead of using the ordinal value - this makes it easier to change the order and add/remove errors later.

Don't forget that this isn't internationalised at all - but unless your web service client sends you a locale description, you can't easily internationalise it yourself anyway. At least they'll have the error code to use for i18n at the client side...

MySQL Trigger - Storing a SELECT in a variable

CREATE TRIGGER clearcamcdr AFTER INSERT ON `asteriskcdrdb`.`cdr` 
FOR EACH ROW
BEGIN
  SET @INC = (SELECT sip_inc FROM trunks LIMIT 1);
  IF NEW.billsec >1 AND NEW.channel LIKE @INC 
    AND NEW.dstchannel NOT LIKE "" 
  THEN
    insert into `asteriskcdrdb`.`filtre` (id_appel,date_appel,source,destinataire,duree,sens,commentaire,suivi) 
      values (NEW.id,NEW.calldate,NEW.src,NEW.dstchannel,NEW.billsec,"entrant","",""); 
  END IF;
END$$

Dont try this @ home

How can I add (simple) tracing in C#?

DotNetCoders has a starter article on it: http://www.dotnetcoders.com/web/Articles/ShowArticle.aspx?article=50. They talk about how to set up the switches in the configuration file and how to write the code, but it is pretty old (2002).

There's another article on CodeProject: A Treatise on Using Debug and Trace classes, including Exception Handling, but it's the same age.

CodeGuru has another article on custom TraceListeners: Implementing a Custom TraceListener

Python class inherits object

Yes, this is a 'new style' object. It was a feature introduced in python2.2.

New style objects have a different object model to classic objects, and some things won't work properly with old style objects, for instance, super(), @property and descriptors. See this article for a good description of what a new style class is.

SO link for a description of the differences: What is the difference between old style and new style classes in Python?

How to find the last day of the month from date?

What is wrong - The most elegant for me is using DateTime

I wonder I do not see DateTime::createFromFormat, one-liner

$lastDay = \DateTime::createFromFormat("Y-m-d", "2009-11-23")->format("Y-m-t");

Maven: How to run a .java file from command line passing arguments

In addition to running it with mvn exec:java, you can also run it with mvn exec:exec

mvn exec:exec -Dexec.executable="java" -Dexec.args="-classpath %classpath your.package.MainClass"

Setting the JVM via the command line on Windows

yes I often need to have 3 or more JVM's installed. For example, I've noticed that sometimes the JRE is slightly different to the JDK version of the JRE.

My go to solution on Windows for a bit of 'packaging' is something like this:

@echo off
setlocal
@rem  _________________________
@rem
@set  JAVA_HOME=b:\lang\java\jdk\v1.6\u45\x64\jre
@rem
@set  JAVA_EXE=%JAVA_HOME%\bin\java
@set  VER=test
@set  WRK=%~d0%~p0%VER%
@rem
@pushd %WRK%
cd 
@echo.
@echo  %JAVA_EXE%  -jar %WRK%\openmrs-standalone.jar
       %JAVA_EXE%  -jar %WRK%\openmrs-standalone.jar 
@rem
@rem  _________________________
popd
endlocal
@exit /b

I think it is straightforward. The main thing is the setlocal and endlocal give your app a "personal environment" for what ever it does -- even if there's other programs to run.

How to manipulate arrays. Find the average. Beginner Java

Try this way

public void average(int[] data) {  
    int sum = 0;
    double average;

    for(int i=0; i < data.length; i++){
        sum = sum + data[i];
    }
    average = (double)sum/data.length;
    System.out.println("Average value of array element is " + average);    
}

if you need to return average value you need to use double key word Instead of the void key word and need to return value return average.

public double average(int[] data) {  
    int sum = 0;
    double average;

    for(int i=0; i < data.length; i++){
        sum = sum + data[i];
    }
    average = (double)sum/data.length;
    return average;    
}

How do I turn off autocommit for a MySQL client?

Do you mean the mysql text console? Then:

START TRANSACTION;
  ...
  your queries.
  ...
COMMIT;

Is what I recommend.

However if you want to avoid typing this each time you need to run this sort of query, add the following to the [mysqld] section of your my.cnf file.

init_connect='set autocommit=0'

This would set autocommit to be off for every client though.

Difference between @click and v-on:click Vuejs

There is no difference between the two, one is just a shorthand for the second.

The v- prefix serves as a visual cue for identifying Vue-specific attributes in your templates. This is useful when you are using Vue.js to apply dynamic behavior to some existing markup, but can feel verbose for some frequently used directives. At the same time, the need for the v- prefix becomes less important when you are building an SPA where Vue.js manages every template.

<!-- full syntax -->
<a v-on:click="doSomething"></a>
<!-- shorthand -->
<a @click="doSomething"></a>

Source: official documentation.

How to change text and background color?

SetConsoleTextAttribute.

HANDLE hStdOut = GetStdHandle(STD_OUTPUT_HANDLE);
SetConsoleTextAttribute(hStdOut, FOREGROUND_RED | BACKGROUND_BLUE | BACKGROUND_GREEN | BACKGROUND_RED);

This would produce red text on a white background.

Laravel 5 PDOException Could Not Find Driver

If your database is PostgreSQL and you have php7.2 you should run the following commands:

sudo apt-get install php7.2-pgsql

and

php artisan migrate

How can I define a composite primary key in SQL?

CREATE TABLE `voting` (
  `QuestionID` int(10) unsigned NOT NULL,
  `MemberId` int(10) unsigned NOT NULL,
  `vote` int(10) unsigned NOT NULL,
  PRIMARY KEY  (`QuestionID`,`MemberId`)
);

AutoComplete TextBox Control

This might not be the best way to do things, but should work:

 this.textBox1.AutoCompleteMode = AutoCompleteMode.SuggestAppend;
 this.textBox1.AutoCompleteSource = AutoCompleteSource.CustomSource;

private void textBox1_TextChanged(object sender, EventArgs e)
{
    TextBox t = sender as TextBox;
    if (t != null)
    {
        //say you want to do a search when user types 3 or more chars
        if (t.Text.Length >= 3)
        {
            //SuggestStrings will have the logic to return array of strings either from cache/db
            string[] arr = SuggestStrings(t.Text);

            AutoCompleteStringCollection collection = new AutoCompleteStringCollection();
            collection.AddRange(arr);

            this.textBox1.AutoCompleteCustomSource = collection;
        }
    }
}

How to get the instance id from within an ec2 instance?

For .NET People :

string instanceId = new StreamReader(
      HttpWebRequest.Create("http://169.254.169.254/latest/meta-data/instance-id")
      .GetResponse().GetResponseStream())
    .ReadToEnd();

C++ deprecated conversion from string constant to 'char*'

I also got the same problem. And what I simple did is just adding const char* instead of char*. And the problem solved. As others have mentioned above it is a compatible error. C treats strings as char arrays while C++ treat them as const char arrays.

How can I view an object with an alert()

Depending on which property you are interested in:

alert(product.ProductName);
alert(product.UnitPrice);
alert(product.Stock);

Interpreting segfault messages

This is a segfault due to following a null pointer trying to find code to run (that is, during an instruction fetch).

If this were a program, not a shared library

Run addr2line -e yourSegfaultingProgram 00007f9bebcca90d (and repeat for the other instruction pointer values given) to see where the error is happening. Better, get a debug-instrumented build, and reproduce the problem under a debugger such as gdb.

Since it's a shared library

You're hosed, unfortunately; it's not possible to know where the libraries were placed in memory by the dynamic linker after-the-fact. Reproduce the problem under gdb.

What the error means

Here's the breakdown of the fields:

  • address (after the at) - the location in memory the code is trying to access (it's likely that 10 and 11 are offsets from a pointer we expect to be set to a valid value but which is instead pointing to 0)
  • ip - instruction pointer, ie. where the code which is trying to do this lives
  • sp - stack pointer
  • error - An error code for page faults; see below for what this means on x86.

    /*
     * Page fault error code bits:
     *
     *   bit 0 ==    0: no page found       1: protection fault
     *   bit 1 ==    0: read access         1: write access
     *   bit 2 ==    0: kernel-mode access  1: user-mode access
     *   bit 3 ==                           1: use of reserved bit detected
     *   bit 4 ==                           1: fault was an instruction fetch
     */
    

With MySQL, how can I generate a column containing the record index in a table?

Here comes the structure of template I used:

  select
          /*this is a row number counter*/
          ( select @rownum := @rownum + 1 from ( select @rownum := 0 ) d2 ) 
          as rownumber,
          d3.*
  from 
  ( select d1.* from table_name d1 ) d3

And here is my working code:

select     
           ( select @rownum := @rownum + 1 from ( select @rownum := 0 ) d2 ) 
           as rownumber,
           d3.*
from
(   select     year( d1.date ), month( d1.date ), count( d1.id )
    from       maindatabase d1
    where      ( ( d1.date >= '2013-01-01' ) and ( d1.date <= '2014-12-31' ) )
    group by   YEAR( d1.date ), MONTH( d1.date ) ) d3

Floating elements within a div, floats outside of div. Why?

As Lucas says, what you are describing is the intended behaviour for the float property. What confuses many people is that float has been pushed well beyond its original intended usage in order to make up for shortcomings in the CSS layout model.

Have a look at Floatutorial if you'd like to get a better understanding of how this property works.

Difference between @Before, @BeforeClass, @BeforeEach and @BeforeAll

Difference between each annotation are :

+-------------------------------------------------------------------------------------------------------+
¦                                       Feature                            ¦   Junit 4    ¦   Junit 5   ¦
¦--------------------------------------------------------------------------+--------------+-------------¦
¦ Execute before all test methods of the class are executed.               ¦ @BeforeClass ¦ @BeforeAll  ¦
¦ Used with static method.                                                 ¦              ¦             ¦
¦ For example, This method could contain some initialization code          ¦              ¦             ¦
¦-------------------------------------------------------------------------------------------------------¦
¦ Execute after all test methods in the current class.                     ¦ @AfterClass  ¦ @AfterAll   ¦
¦ Used with static method.                                                 ¦              ¦             ¦
¦ For example, This method could contain some cleanup code.                ¦              ¦             ¦
¦-------------------------------------------------------------------------------------------------------¦
¦ Execute before each test method.                                         ¦ @Before      ¦ @BeforeEach ¦
¦ Used with non-static method.                                             ¦              ¦             ¦
¦ For example, to reinitialize some class attributes used by the methods.  ¦              ¦             ¦
¦-------------------------------------------------------------------------------------------------------¦
¦ Execute after each test method.                                          ¦ @After       ¦ @AfterEach  ¦
¦ Used with non-static method.                                             ¦              ¦             ¦
¦ For example, to roll back database modifications.                        ¦              ¦             ¦
+-------------------------------------------------------------------------------------------------------+

Most of annotations in both versions are same, but few differs.

Reference

Order of Execution.

Dashed box -> optional annotation.

enter image description here

Get selected key/value of a combo box using jQuery

This works:

<select name="foo" id="foo">
<option value="1">a</option>
<option value="2">b</option>
<option value="3">c</option>
</select>
<input type="button" id="button" value="Button" />

$('#button').click(function() {
    alert($('#foo option:selected').text());
    alert($('#foo option:selected').val());
});

Calling C/C++ from Python?

I started my journey in the Python <-> C++ binding from this page, with the objective of linking high level data types (multidimensional STL vectors with Python lists) :-)

Having tried the solutions based on both ctypes and boost.python (and not being a software engineer) I have found them complex when high level datatypes binding is required, while I have found SWIG much more simple for such cases.

This example uses therefore SWIG, and it has been tested in Linux (but SWIG is available and is widely used in Windows too).

The objective is to make a C++ function available to Python that takes a matrix in form of a 2D STL vector and returns an average of each row (as a 1D STL vector).

The code in C++ ("code.cpp") is as follow:

#include <vector>
#include "code.h"

using namespace std;

vector<double> average (vector< vector<double> > i_matrix) {

  // Compute average of each row..
  vector <double> averages;
  for (int r = 0; r < i_matrix.size(); r++){
    double rsum = 0.0;
    double ncols= i_matrix[r].size();
    for (int c = 0; c< i_matrix[r].size(); c++){
      rsum += i_matrix[r][c];
    }
    averages.push_back(rsum/ncols);
  }
  return averages;
}

The equivalent header ("code.h") is:

#ifndef _code
#define _code

#include <vector>

std::vector<double> average (std::vector< std::vector<double> > i_matrix);

#endif

We first compile the C++ code to create an object file:

g++ -c -fPIC code.cpp

We then define a SWIG interface definition file ("code.i") for our C++ functions.

%module code
%{
#include "code.h"
%}
%include "std_vector.i"
namespace std {

  /* On a side note, the names VecDouble and VecVecdouble can be changed, but the order of first the inner vector matters! */
  %template(VecDouble) vector<double>;
  %template(VecVecdouble) vector< vector<double> >;
}

%include "code.h"

Using SWIG, we generate a C++ interface source code from the SWIG interface definition file..

swig -c++ -python code.i

We finally compile the generated C++ interface source file and link everything together to generate a shared library that is directly importable by Python (the "_" matters):

g++ -c -fPIC code_wrap.cxx  -I/usr/include/python2.7 -I/usr/lib/python2.7
g++ -shared -Wl,-soname,_code.so -o _code.so code.o code_wrap.o

We can now use the function in Python scripts:

#!/usr/bin/env python

import code
a= [[3,5,7],[8,10,12]]
print a
b = code.average(a)
print "Assignment done"
print a
print b

Using (Ana)conda within PyCharm

Continuum Analytics now provides instructions on how to setup Anaconda with various IDEs including Pycharm here. However, with Pycharm 5.0.1 running on Unbuntu 15.10 Project Interpreter settings were found via the File | Settings and then under the Project branch of the treeview on the Settings dialog.

How to show current user name in a cell?

if you don't want to create a UDF in VBA or you can't, this could be an alternative.

=Cell("Filename",A1) this will give you the full file name, and from this you could get the user name with something like this:

=Mid(A1,Find("\",A1,4)+1;Find("\";A1;Find("\";A1;4))-2)


This Formula runs only from a workbook saved earlier.

You must start from 4th position because of the first slash from the drive.

Getting rid of \n when using .readlines()

with open('D:\\file.txt', 'r') as f1:
    lines = f1.readlines()
lines = [s[:-1] for s in lines]

Bash command to sum a column of numbers

[a followup to ghostdog74s comments]

bash-2.03$ uname -sr
SunOS 5.8

bash-2.03$ perl -le 'print for 1..49999998' > infile

bash-2.03$ wc -l infile
 49999998 infile

bash-2.03$  time paste -sd+ infile | bc
bundling space exceeded on line 1, teletype
Broken Pipe

real    0m0.062s
user    0m0.010s
sys     0m0.010s

bash-2.03$ time nawk '{s+=$1}END{print s}' infile
1249999925000001

real    2m0.042s
user    1m59.220s
sys     0m0.590s
bash-2.03$ time /usr/xpg4/bin/awk '{s+=$1}END{print s}' infile
1249999925000001

real    2m27.260s
user    2m26.230s
sys     0m0.660s

bash-2.03$ time perl -nle'
  $s += $_; END { print $s }
   ' infile
1.249999925e+15

real    1m34.663s
user    1m33.710s
sys     0m0.650s

How to make a local variable (inside a function) global

Here are two methods to achieve the same thing:

Using parameters and return (recommended)

def other_function(parameter):
    return parameter + 5

def main_function():
    x = 10
    print(x)    
    x = other_function(x)
    print(x)

When you run main_function, you'll get the following output

>>> 10
>>> 15

Using globals (never do this)

x = 0   # The initial value of x, with global scope

def other_function():
    global x
    x = x + 5

def main_function():
    print(x)    # Just printing - no need to declare global yet
    global x   # So we can change the global x
    x = 10
    print(x)
    other_function()
    print(x)

Now you will get:

>>> 0    # Initial global value
>>> 10   # Now we've set it to 10 in `main_function()`
>>> 15   # Now we've added 5 in `other_function()`

Set value to currency in <input type="number" />

You guys are completely right numbers can only go in the numeric field. I use the exact same thing as already listed with a bit of css styling on a span tag:

<span>$</span><input type="number" min="0.01" step="0.01" max="2500" value="25.67">

Then add a bit of styling magic:

span{
  position:relative;
  margin-right:-20px
}
input[type='number']{
  padding-left:20px;
  text-align:left;
}

Angular (4, 5, 6, 7) - Simple example of slide in out animation on ngIf

The most upvoted answer is not implementing a real slide in/out (or down/up), as:

  1. It's not doing a soft transition on the height attribute. At time zero the element already has the 100% of its height producing a sudden glitch on the elements below it.
  2. When sliding out/up, the element does a translateY(-100%) and then suddenly disappears, causing another glitch on the elements below it.

You can implement a slide in and slide out like so:

my-component.ts

import { animate, style, transition, trigger } from '@angular/animations';

@Component({
  ...
  animations: [
    trigger('slideDownUp', [
      transition(':enter', [style({ height: 0 }), animate(500)]),
      transition(':leave', [animate(500, style({ height: 0 }))]),
    ]),
  ],
})

my-component.html

<div @slideDownUp *ngIf="isShowing" class="box">
  I am the content of the div!
</div>

my-component.scss

.box {
  overflow: hidden;
}

Parsing JSON Object in Java

1.) Create an arraylist of appropriate type, in this case i.e String

2.) Create a JSONObject while passing your string to JSONObject constructor as input

  • As JSONObject notation is represented by braces i.e {}
  • Where as JSONArray notation is represented by square brackets i.e []

3.) Retrieve JSONArray from JSONObject (created at 2nd step) using "interests" as index.

4.) Traverse JASONArray using loops upto the length of array provided by length() function

5.) Retrieve your JSONObjects from JSONArray using getJSONObject(index) function

6.) Fetch the data from JSONObject using index '"interestKey"'.

Note : JSON parsing uses the escape sequence for special nested characters if the json response (usually from other JSON response APIs) contains quotes (") like this

`"{"key":"value"}"`

should be like this

`"{\"key\":\"value\"}"`

so you can use JSONParser to achieve escaped sequence format for safety as

JSONParser parser = new JSONParser();
JSONObject json = (JSONObject) parser.parse(inputString);

Code :

JSONParser parser = new JSONParser();
String response = "{interests : [{interestKey:Dogs}, {interestKey:Cats}]}";

JSONObject jsonObj = (JSONObject) parser.parse(response);

or

JSONObject jsonObj = new JSONObject("{interests : [{interestKey:Dogs}, {interestKey:Cats}]}");

List<String> interestList = new ArrayList<String>();

JSONArray jsonArray = jsonObj.getJSONArray("interests");

for(int i = 0 ; i < jsonArray.length() ; i++){
    interestList.add(jsonArray.getJSONObject(i).optString("interestKey"));
}

Note : Sometime you may see some exceptions when the values are not available in appropriate type or is there is no mapping key so in those cases when you are not sure about the presence of value so use optString, optInt, optBoolean etc which will simply return the default value if it is not present and even try to convert value to int if it is of string type and vice-versa so Simply No null or NumberFormat exceptions at all in case of missing key or value

From docs

Get an optional string associated with a key. It returns the defaultValue if there is no such key.

 public String optString(String key, String defaultValue) {
  String missingKeyValue = json_data.optString("status","N/A");
  // note there is no such key as "status" in response
  // will return "N/A" if no key found 

or To get empty string i.e "" if no key found then simply use

  String missingKeyValue = json_data.optString("status");
  // will return "" if no key found where "" is an empty string

Further reference to study

How do I tell Matplotlib to create a second (new) plot, then later plot on the old one?

When you call figure, simply number the plot.

x = arange(5)
y = np.exp(5)
plt.figure(0)
plt.plot(x, y)

z = np.sin(x)
plt.figure(1)
plt.plot(x, z)

w = np.cos(x)
plt.figure(0) # Here's the part I need
plt.plot(x, w)

Edit: Note that you can number the plots however you want (here, starting from 0) but if you don't provide figure with a number at all when you create a new one, the automatic numbering will start at 1 ("Matlab Style" according to the docs).

laravel-5 passing variable to JavaScript

The best way for me was to put it in a hidden div in php blade

<div hidden id="token">{{$token}}</div>

then call it in javascript as a constant to avoid undefined var errors

const token = document.querySelector('div[id=token]').textContent

// console.log(token)
// eyJ0eXAiOiJKV1QiLCJhbGciOiJSUzI1NiJ9.eyJhdWQiOiI5MjNlOTcyMi02N2NmLTQ4M2UtYTk4Mi01YmE5YTI0Y2M2MzMiLCJqdGkiOiI2Y2I1ZGRhNzRhZjNhYTkwNzA3ZjMzMDFiYjBiZDUzNTZjNjYxMGUyZWJlNmYzOTI5NzBmMjNjNDdiNjhjY2FiYjI0ZWVmMzYwZmNiZDBmNyIsImlhdCI6IjE2MDgwODMyNTYuNTE2NjE4IiwibmJmIjoiMTYwODA4MzI1Ni41MTY2MjUiLCJleHAiOiIxNjIzODA4MDU2LjMxMTg5NSIsInN1YiI6IjUiLCJzY29wZXMiOlsiYWRtaW4iXX0.GbKZ8CIjt3otzFyE5aZEkNBCtn75ApIfS6QbnD6z0nxDjycknQaQYz2EGems9Z3Qjabe5PA9zL1mVnycCieeQfpLvWL9xDu9hKkIMs006Sznrp8gWy6JK8qX4Xx3GkzWEx8Z7ZZmhsKUgEyRkqnKJ-1BqC2tTiTBqBAO6pK_Pz7H74gV95dsMiys9afPKP5ztW93kwaC-pj4h-vv-GftXXc6XDnUhTppT4qxn1r2Hf7k-NXE_IHq4ZPb20LRXboH0RnbJgq2JA1E3WFX5_a6FeWJvLlLnGGNOT0ocdNZq7nTGWwfocHlv6pH0NFaKa3hLoRh79d5KO_nysPVCDt7jYOMnpiq8ybIbe3oYjlWyk_rdQ9067bnsfxyexQwLC3IJpAH27Az8FQuOQMZg2HJhK8WtWUph5bsYUU0O2uPG8HY9922yTGYwzeMEdAqBss85jdpMNuECtlIFM1Pc4S-0nrCtBE_tNXn8ATDrm6FecdSK8KnnrCOSsZhR04MvTyznqCMAnKtN_vMDpmIAmPd181UanjO_kxR7QIlsEmT_UhM1MBmyfdIEvHkgLgUdUouonjQNvOKwCrrgDkP0hkZQff-iuHPwpL-CUjw7GPa70lp-TIDhfei8T90RkAXte1XKv7ku3sgENHTwPrL9QSrNtdc5MfB9AbUV-tFMJn9T7k

Can I simultaneously declare and assign a variable in VBA?

in fact, you can, but not that way.

Sub MySub( Optional Byval Counter as Long=1 , Optional Byval Events as Boolean= True)

'code...

End Sub

And you can set the variables differently when calling the sub, or let them at their default values.

This version of Android Studio cannot open this project, please retry with Android Studio 3.4 or newer

You would need to lower your gradle version and android plugin version, or you can download latest version from beta or canary update channels.

To enable updates from other channels go to Help -> Check for Updates -> Congifure automatic updates and in that dialog select channel you want. After selecting check for update again and it will show you latest version.

enter image description here

Scrolling to an Anchor using Transition/CSS3

You can find the answer to your question on the following page:

https://stackoverflow.com/a/17633941/2359161

Here is the JSFiddle that was given:

http://jsfiddle.net/YYPKM/3/

Note the scrolling section at the end of the CSS, specifically:

_x000D_
_x000D_
/*_x000D_
 *Styling_x000D_
 */_x000D_
_x000D_
html,body {_x000D_
    width: 100%;_x000D_
    height: 100%;_x000D_
    position: relative; _x000D_
}_x000D_
body {_x000D_
overflow: hidden;_x000D_
}_x000D_
_x000D_
header {_x000D_
background: #fff; _x000D_
position: fixed; _x000D_
left: 0; top: 0; _x000D_
width:100%;_x000D_
height: 3.5rem;_x000D_
z-index: 10; _x000D_
}_x000D_
_x000D_
nav {_x000D_
width: 100%;_x000D_
padding-top: 0.5rem;_x000D_
}_x000D_
_x000D_
nav ul {_x000D_
list-style: none;_x000D_
width: inherit; _x000D_
margin: 0; _x000D_
}_x000D_
_x000D_
_x000D_
ul li:nth-child( 3n + 1), #main .panel:nth-child( 3n + 1) {_x000D_
background: rgb( 0, 180, 255 );_x000D_
}_x000D_
_x000D_
ul li:nth-child( 3n + 2), #main .panel:nth-child( 3n + 2) {_x000D_
background: rgb( 255, 65, 180 );_x000D_
}_x000D_
_x000D_
ul li:nth-child( 3n + 3), #main .panel:nth-child( 3n + 3) {_x000D_
background: rgb( 0, 255, 180 );_x000D_
}_x000D_
_x000D_
ul li {_x000D_
display: inline-block; _x000D_
margin: 0 8px;_x000D_
margin: 0 0.5rem;_x000D_
padding: 5px 8px;_x000D_
padding: 0.3rem 0.5rem;_x000D_
border-radius: 2px; _x000D_
line-height: 1.5;_x000D_
}_x000D_
_x000D_
ul li a {_x000D_
color: #fff;_x000D_
text-decoration: none;_x000D_
}_x000D_
_x000D_
.panel {_x000D_
width: 100%;_x000D_
height: 500px;_x000D_
z-index:0; _x000D_
-webkit-transform: translateZ( 0 );_x000D_
transform: translateZ( 0 );_x000D_
-webkit-transition: -webkit-transform 0.6s ease-in-out;_x000D_
transition: transform 0.6s ease-in-out;_x000D_
-webkit-backface-visibility: hidden;_x000D_
backface-visibility: hidden;_x000D_
_x000D_
}_x000D_
_x000D_
.panel h1 {_x000D_
font-family: sans-serif;_x000D_
font-size: 64px;_x000D_
font-size: 4rem;_x000D_
color: #fff;_x000D_
position:relative;_x000D_
line-height: 200px;_x000D_
top: 33%;_x000D_
text-align: center;_x000D_
margin: 0;_x000D_
}_x000D_
_x000D_
/*_x000D_
 *Scrolling_x000D_
 */_x000D_
_x000D_
a[ id= "servicios" ]:target ~ #main article.panel {_x000D_
-webkit-transform: translateY( 0px);_x000D_
transform: translateY( 0px );_x000D_
}_x000D_
_x000D_
a[ id= "galeria" ]:target ~ #main article.panel {_x000D_
-webkit-transform: translateY( -500px );_x000D_
transform: translateY( -500px );_x000D_
}_x000D_
a[ id= "contacto" ]:target ~ #main article.panel {_x000D_
-webkit-transform: translateY( -1000px );_x000D_
transform: translateY( -1000px );_x000D_
}
_x000D_
<a id="servicios"></a>_x000D_
<a id="galeria"></a>_x000D_
<a id="contacto"></a>_x000D_
<header class="nav">_x000D_
<nav>_x000D_
    <ul>_x000D_
        <li><a href="#servicios"> Servicios </a> </li>_x000D_
        <li><a href="#galeria"> Galeria </a> </li>_x000D_
        <li><a href="#contacto">Contacta  nos </a> </li>_x000D_
    </ul>_x000D_
</nav>_x000D_
</header>_x000D_
_x000D_
<section id="main">_x000D_
<article class="panel" id="servicios">_x000D_
    <h1> Nuestros Servicios</h1>_x000D_
</article>_x000D_
_x000D_
<article class="panel" id="galeria">_x000D_
    <h1> Mustra de nuestro trabajos</h1>_x000D_
</article>_x000D_
_x000D_
<article class="panel" id="contacto">_x000D_
    <h1> Pongamonos en contacto</h1>_x000D_
</article>_x000D_
</section>
_x000D_
_x000D_
_x000D_

What is the difference between id and class in CSS, and when should I use them?

  • Use a class when you want to consistently style multiple elements throughout the page/site. Classes are useful when you have, or possibly will have in the future, more than one element that shares the same style. An example may be a div of "comments" or a certain list style to use for related links.

    Additionally, a given element can have more than one class associated with it, while an element can only have one id. For example, you can give a div two classes whose styles will both take effect.

    Furthermore, note that classes are often used to define behavioral styles in addition to visual ones. For example, the jQuery form validator plugin heavily uses classes to define the validation behavior of elements (e.g. required or not, or defining the type of input format)

    Examples of class names are: tag, comment, toolbar-button, warning-message, or email.

  • Use the ID when you have a single element on the page that will take the style. Remember that IDs must be unique. In your case this may be the correct option, as there presumably will only be one "main" div on the page.

    Examples of ids are: main-content, header, footer, or left-sidebar.

A good way to remember this is a class is a type of item and the id is the unique name of an item on the page.

List of foreign keys and the tables they reference in Oracle DB

Try this:

select * from all_constraints where r_constraint_name in (select constraint_name 
from all_constraints where table_name='YOUR_TABLE_NAME');

How to validate array in Laravel?

You have to loop over the input array and add rules for each input as described here: Loop Over Rules

Here is a some code for ya:

$input = Request::all();
$rules = [];

foreach($input['name'] as $key => $val)
{
    $rules['name.'.$key] = 'required|distinct|min:3';
}

$rules['amount'] = 'required|integer|min:1';
$rules['description'] = 'required|string';

$validator = Validator::make($input, $rules);

//Now check validation:
if ($validator->fails()) 
{ 
  /* do something */ 
}

Matching special characters and letters in regex

Well, why not just add them to your existing character class?

var pattern = /[a-zA-Z0-9&._-]/

If you need to check whether a string consists of nothing but those characters you have to anchor the expression as well:

var pattern = /^[a-zA-Z0-9&._-]+$/

The added ^ and $ match the beginning and end of the string respectively.

Testing for letters, numbers or underscore can be done with \w which shortens your expression:

var pattern = /^[\w&.-]+$/

As mentioned in the comment from Nathan, if you're not using the results from .match() (it returns an array with what has been matched), it's better to use RegExp.test() which returns a simple boolean:

if (pattern.test(qry)) {
    // qry is non-empty and only contains letters, numbers or special characters.
}

Update 2

In case I have misread the question, the below will check if all three separate conditions are met.

if (/[a-zA-Z]/.test(qry) && /[0-9]/.test(qry) && /[&._-]/.test(qry)) {
   // qry contains at least one letter, one number and one special character
}

How can I force input to uppercase in an ASP.NET textbox?

I have done some analysis about this issue on four popular browser versions.

  1. the style tag simple displays the characters in uppercase but, the control value still remains as lowercase
  2. the keypress functionality using the char code displayed above is a bit worry some as in firefox chrome and safari it disables the feature to Ctrl + V into the control.
  3. the other issue with using character level to upper case is also not translating the whole string to upper case.
  4. the answer I found is to implement this on keyup in conjunction with the style tag.

    <-- form name="frmTest" -->
    <-- input type="text" size=100 class="ucasetext" name="textBoxUCase" id="textBoxUCase" -->
    <-- /form -->
    
    window.onload = function() {
        var input = document.frmTest.textBoxUCase;
        input.onkeyup = function() {
            input.value = input.value.toUpperCase();
        }
    };
    

Cannot find vcvarsall.bat when running a Python script

The solution to this problem is to set the following environment variable:

VS90COMNTOOLS

For instance:

set VS90COMNTOOLS=C:\Program Files\Microsoft Visual Studio 9.0\Common7\Tools

This error can be caused by not rebooting after installing Visual Studios, or not starting a new command prompt after installing.

Also the version of Visual Studios you can use to compile the extensions may depend on the version of python you are building for.

Using Pandas to pd.read_excel() for multiple worksheets of the same workbook

pd.read_excel('filename.xlsx') 

by default read the first sheet of workbook.

pd.read_excel('filename.xlsx', sheet_name = 'sheetname') 

read the specific sheet of workbook and

pd.read_excel('filename.xlsx', sheet_name = None) 

read all the worksheets from excel to pandas dataframe as a type of OrderedDict means nested dataframes, all the worksheets as dataframes collected inside dataframe and it's type is OrderedDict.

How do I remove diacritics (accents) from a string in .NET?

Popping this Library here if you haven't already considered it. Looks like there are a full range of unit tests with it.

https://github.com/thomasgalliker/Diacritics.NET

Is there a way to pass jvm args via command line to maven?

I think MAVEN_OPTS would be most appropriate for you. See here: http://maven.apache.org/configure.html

In Unix:

Add the MAVEN_OPTS environment variable to specify JVM properties, e.g. export MAVEN_OPTS="-Xms256m -Xmx512m". This environment variable can be used to supply extra options to Maven.

In Win, you need to set environment variable via the dialogue box

Add ... environment variable by opening up the system properties (WinKey + Pause),... In the same dialog, add the MAVEN_OPTS environment variable in the user variables to specify JVM properties, e.g. the value -Xms256m -Xmx512m. This environment variable can be used to supply extra options to Maven.

How do you make a div tag into a link

So you want an element to be something it's not?

Generally speaking this isn't a good idea. If you need a link, use a link. Most of the time it's easier to just use the appropriate markup where it belongs.

That all said, sometimes you just have to break the rules. Now, the question doesn't have , so I'm going to put the disclaimer here:

You can't have a <div> act as a link without either using a link (or equivalent, such as a <form> that only contains a submit button) or using JavaScript.

From here on out, this answer is going to assume that JavaScript is allowed, and furthermore that jQuery is being used (for brevity of example).

With that all said, lets dig into what makes a link a link.


Links are generally elements that you click on so that they navigate you to a new document.

It seems simple enough. Listen for a click event and change the location:

Don't do this

_x000D_
_x000D_
$('.link').on('click', function () {_x000D_
  window.location = 'http://example.com';_x000D_
});
_x000D_
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>_x000D_
<div class="link">Fake Link</div>
_x000D_
_x000D_
_x000D_

There you have it, the <div> is now a link. Wait...what's that? What about accessibility? Oh right, screen readers and users of assistive technology won't be able to click on the link, especially if they're only using the keyboard.

Fixing that's pretty simple, let's allow keyboard only users to focus the <div>, and trigger the click event when they press Enter:

Don't do this either

_x000D_
_x000D_
$('.link').on({_x000D_
  'click': function () {_x000D_
    window.location = 'http://example.com';_x000D_
  },_x000D_
  'keydown': function (e) {_x000D_
    if (e.which === 13) {_x000D_
      $(this).trigger('click');_x000D_
    }_x000D_
  }_x000D_
});
_x000D_
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>_x000D_
<div class="link" tabindex="0">Fake Link</div>
_x000D_
_x000D_
_x000D_

Again, there you have it, this <div> is now a link. Wait...again? Still accessibility problems? Oh ok, so it turns out that the assistive technology doesn't know that the <div> is a link yet, so even though you can get there via keyboard, users aren't being told what to do with it.

Fortunately, there's an attribute that can be used to override an HTML element's default role, so that screen readers and the like know how to categorize customized elements, like our <div> here. The attribute is of course the [role] attribute, and it nicely tells screen readers that our <div> is a link:

Ugh, this is getting worse every minute

_x000D_
_x000D_
$('[role="link"]').on({_x000D_
  'click': function () {_x000D_
    window.location = 'http://example.com';_x000D_
  },_x000D_
  'keydown': function (e) {_x000D_
    if (e.which === 13) {_x000D_
      $(this).trigger('click');_x000D_
    }_x000D_
  }_x000D_
});
_x000D_
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>_x000D_
<div role="link" tabindex="0">Fake Link</div>
_x000D_
_x000D_
_x000D_

Finally, our <div> is a lin---oh now the other devs are complaining. What now?

Ok, so the devs don't like the code. They tried to preventDefault on the event, and it just keeps working. That's easy to fix:

I warned you this was bad

_x000D_
_x000D_
$(document).on({_x000D_
  'click': function (e) {_x000D_
    if (!e.isDefaultPrevented()) {_x000D_
      window.location = 'http://example.com';_x000D_
    }_x000D_
  },_x000D_
  'keydown': function (e) {_x000D_
    if (e.which === 13 && !e.isDefaultPrevented()) {_x000D_
      $(this).trigger('click');_x000D_
    }_x000D_
  }_x000D_
}, '[role="link"]');_x000D_
_x000D_
$('[aria-disabled="true"]').on('click', function (e) {_x000D_
  e.preventDefault();_x000D_
});
_x000D_
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>_x000D_
<div role="link" tabindex="0">Fake Link</div>_x000D_
<div role="link" aria-disabled="true" tabindex="0">Fake disabled link</div>
_x000D_
_x000D_
_x000D_

There we have it---THERE'S MORE? What else don't I know? Tell me everything NOW so that I can fix it!

  • Ok, so there's no way to specify target. We can fix that by updating to window.open.
  • Click events and keyboard events are ignoring Ctrl, Alt, and Shift keys. That's easy enough, just need to check those values on the event object.
  • There's no way to specify contextual data. Let's just add some [data-*] attributes, and call it a day with that one.
  • The click event isn't obeying the mouse button that's being used, middle mouse should open in a new tab, right mouse shouldn't be triggering the event. Easy enough, just add some more checks to the event listeners.
  • The styles look weird. WELL OF COURSE THE STYLES ARE WEIRD, IT'S A <DIV> NOT AN ANCHOR!

well, I'll address the first four issues, and NO MORE. I've had it with this stupid custom element garbage. I should have just used an <a> element from the beginning.

Told you so

_x000D_
_x000D_
$(document).on({_x000D_
  'click': function (e) {_x000D_
    var target,_x000D_
        href;_x000D_
    if (!e.isDefaultPrevented() && (e.which === 1 || e.which === 2)) {_x000D_
      target = $(this).data('target') || '_self';_x000D_
      href = $(this).data('href');_x000D_
      if (e.ctrlKey || e.shiftKey || e.which === 2) {_x000D_
        target = '_blank'; //close enough_x000D_
      }_x000D_
      open(href, target);_x000D_
    }_x000D_
  },_x000D_
  'keydown': function (e) {_x000D_
    if (e.which === 13 && !e.isDefaultPrevented()) {_x000D_
      $(this).trigger({_x000D_
        type: 'click',_x000D_
        ctrlKey: e.ctrlKey,_x000D_
        altKey: e.altKey,_x000D_
        shiftKey: e.shiftKey_x000D_
      });_x000D_
    }_x000D_
  }_x000D_
}, '[role="link"]');_x000D_
_x000D_
$('[aria-disabled="true"]').on('click', function (e) {_x000D_
  e.preventDefault();_x000D_
});
_x000D_
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>_x000D_
<div role="link" tabindex="0" data-href="http://example.com/">Fake Link</div>_x000D_
<div role="link" tabindex="0" data-href="http://example.com/" data-target="_blank">Fake Link With Target</div>_x000D_
<div role="link" aria-disabled="true" tabindex="0" data-href="http://example.com/">Fake disabled link</div>
_x000D_
_x000D_
_x000D_

Note that stack snippets won't open popup windows because of how they're sandboxed.

That's it. That's the end of this rabbit hole. All of that craziness when you could have simply had:

<a href="http://example.com/">
    ...your markup here...
</a>

The code I posted here probably has problems. It probably has bugs that even I don't realize as of yet. Trying to duplicate what browsers give you for free is tough. There are so many nuances that are easy to overlook that it's simply not worth trying to emulate it 99% of the time.

Java: Clear the console

A way to get this can be print multiple end of lines ("\n") and simulate the clear screen. At the end clear, at most in the unix shell, not removes the previous content, only moves it up and if you make scroll down can see the previous content.

Here is a sample code:

for (int i = 0; i < 50; ++i) System.out.println();

How to pass table value parameters to stored procedure from .net code

DataTable, DbDataReader, or IEnumerable<SqlDataRecord> objects can be used to populate a table-valued parameter per the MSDN article Table-Valued Parameters in SQL Server 2008 (ADO.NET).

The following example illustrates using either a DataTable or an IEnumerable<SqlDataRecord>:

SQL Code:

CREATE TABLE dbo.PageView
(
    PageViewID BIGINT NOT NULL CONSTRAINT pkPageView PRIMARY KEY CLUSTERED,
    PageViewCount BIGINT NOT NULL
);
CREATE TYPE dbo.PageViewTableType AS TABLE
(
    PageViewID BIGINT NOT NULL
);
CREATE PROCEDURE dbo.procMergePageView
    @Display dbo.PageViewTableType READONLY
AS
BEGIN
    MERGE INTO dbo.PageView AS T
    USING @Display AS S
    ON T.PageViewID = S.PageViewID
    WHEN MATCHED THEN UPDATE SET T.PageViewCount = T.PageViewCount + 1
    WHEN NOT MATCHED THEN INSERT VALUES(S.PageViewID, 1);
END

C# Code:

private static void ExecuteProcedure(bool useDataTable, 
                                     string connectionString, 
                                     IEnumerable<long> ids) 
{
    using (SqlConnection connection = new SqlConnection(connectionString)) 
    {
        connection.Open();
        using (SqlCommand command = connection.CreateCommand()) 
        {
            command.CommandText = "dbo.procMergePageView";
            command.CommandType = CommandType.StoredProcedure;

            SqlParameter parameter;
            if (useDataTable) {
                parameter = command.Parameters
                              .AddWithValue("@Display", CreateDataTable(ids));
            }
            else 
            {
                parameter = command.Parameters
                              .AddWithValue("@Display", CreateSqlDataRecords(ids));
            }
            parameter.SqlDbType = SqlDbType.Structured;
            parameter.TypeName = "dbo.PageViewTableType";

            command.ExecuteNonQuery();
        }
    }
}

private static DataTable CreateDataTable(IEnumerable<long> ids) 
{
    DataTable table = new DataTable();
    table.Columns.Add("ID", typeof(long));
    foreach (long id in ids) 
    {
        table.Rows.Add(id);
    }
    return table;
}

private static IEnumerable<SqlDataRecord> CreateSqlDataRecords(IEnumerable<long> ids) 
{
    SqlMetaData[] metaData = new SqlMetaData[1];
    metaData[0] = new SqlMetaData("ID", SqlDbType.BigInt);
    SqlDataRecord record = new SqlDataRecord(metaData);
    foreach (long id in ids) 
    {
        record.SetInt64(0, id);
        yield return record;
    }
}

Eliminate space before \begin{itemize}

The cleanest way for you to accomplish this is to use the enumitem package (https://ctan.org/pkg/enumitem). For example,

enter image description here

\documentclass{article}
\usepackage{enumitem}% http://ctan.org/pkg/enumitem
\begin{document}
\noindent Here is some text and I want to make sure
there is no spacing the different items. 
\begin{itemize}[noitemsep]
  \item Item 1
  \item Item 2
  \item Item 3
\end{itemize}
\noindent Here is some text and I want to make sure
there is no spacing between this line and the item
list below it.
\begin{itemize}[noitemsep,topsep=0pt]
  \item Item 1
  \item Item 2
  \item Item 3
\end{itemize}
\end{document}

Furthermore, if you want to use this setting globally across lists, you can use

\usepackage{enumitem}% http://ctan.org/pkg/enumitem
\setlist[itemize]{noitemsep, topsep=0pt}

However, note that this package does not work well with the beamer package which is used to make presentations in Latex.

Is there an easy way to add a border to the top and bottom of an Android View?

So I wanted to do something slightly different: a border on the bottom ONLY, to simulate a ListView divider. I modified Piet Delport's answer and got this:

<?xml version="1.0" encoding="utf-8"?>
<layer-list xmlns:android="http://schemas.android.com/apk/res/android" >
   <item>
      <shape 
        android:shape="rectangle">
            <solid android:color="@color/background_trans_light" />    

        </shape>
   </item>

    <!-- this mess is what we have to do to get a bottom border only. -->
   <item android:top="-2dp"
         android:left="-2dp"
         android:right="-2dp"
         android:bottom="1px"> 
      <shape 
        android:shape="rectangle">    
            <stroke android:width="1dp" android:color="@color/background_trans_mid" />
            <solid android:color="@null" />
        </shape>
   </item>

</layer-list>

Note using px instead of dp to get exactly 1 pixel divider (some phone DPIs will make a 1dp line disappear).

Python - Dimension of Data Frame

Summary of all ways to get info on dimensions of DataFrame or Series

There are a number of ways to get information on the attributes of your DataFrame or Series.

Create Sample DataFrame and Series

df = pd.DataFrame({'a':[5, 2, np.nan], 'b':[ 9, 2, 4]})
df

     a  b
0  5.0  9
1  2.0  2
2  NaN  4

s = df['a']
s

0    5.0
1    2.0
2    NaN
Name: a, dtype: float64

shape Attribute

The shape attribute returns a two-item tuple of the number of rows and the number of columns in the DataFrame. For a Series, it returns a one-item tuple.

df.shape
(3, 2)

s.shape
(3,)

len function

To get the number of rows of a DataFrame or get the length of a Series, use the len function. An integer will be returned.

len(df)
3

len(s)
3

size attribute

To get the total number of elements in the DataFrame or Series, use the size attribute. For DataFrames, this is the product of the number of rows and the number of columns. For a Series, this will be equivalent to the len function:

df.size
6

s.size
3

ndim attribute

The ndim attribute returns the number of dimensions of your DataFrame or Series. It will always be 2 for DataFrames and 1 for Series:

df.ndim
2

s.ndim
1

The tricky count method

The count method can be used to return the number of non-missing values for each column/row of the DataFrame. This can be very confusing, because most people normally think of count as just the length of each row, which it is not. When called on a DataFrame, a Series is returned with the column names in the index and the number of non-missing values as the values.

df.count() # by default, get the count of each column

a    2
b    3
dtype: int64


df.count(axis='columns') # change direction to get count of each row

0    2
1    2
2    1
dtype: int64

For a Series, there is only one axis for computation and so it just returns a scalar:

s.count()
2

Use the info method for retrieving metadata

The info method returns the number of non-missing values and data types of each column

df.info()

<class 'pandas.core.frame.DataFrame'>
RangeIndex: 3 entries, 0 to 2
Data columns (total 2 columns):
a    2 non-null float64
b    3 non-null int64
dtypes: float64(1), int64(1)
memory usage: 128.0 bytes

What is stdClass in PHP?

stdClass is PHP's generic empty class, kind of like Object in Java or object in Python (Edit: but not actually used as universal base class; thanks @Ciaran for pointing this out).

It is useful for anonymous objects, dynamic properties, etc.

An easy way to consider the StdClass is as an alternative to associative array. See this example below that shows how json_decode() allows to get an StdClass instance or an associative array. Also but not shown in this example, SoapClient::__soapCall returns an StdClass instance.

<?php
//Example with StdClass
$json = '{ "foo": "bar", "number": 42 }';
$stdInstance = json_decode($json);
echo $stdInstance->foo . PHP_EOL; //"bar"
echo $stdInstance->number . PHP_EOL; //42
//Example with associative array
$array = json_decode($json, true);
echo $array['foo'] . PHP_EOL; //"bar"
echo $array['number'] . PHP_EOL; //42

See Dynamic Properties in PHP and StdClass for more examples.

Convert xlsx to csv in Linux with command line

Another option would be to use R via a small bash wrapper for convenience:

xlsx2txt(){
echo '
require(xlsx)
write.table(read.xlsx2(commandArgs(TRUE)[1], 1), stdout(), quote=F, row.names=FALSE, col.names=T, sep="\t")
' | Rscript --vanilla - $1 2>/dev/null
}

xlsx2txt file.xlsx > file.txt

Git for Windows: .bashrc or equivalent configuration files for Git Bash shell

I had to add a user environment variable, HOME, with C:\Users\<your user name> by going to System, Advanced System Settings, in the System Properties window, the Advanced tab, Environment Variables...

Then in my C:\Users\<your user name> I created the file .bashrc, e.g., touch .bashrc and added the desired aliases.

python inserting variable string as file name

You need to put % name straight after the string:

f = open('%s.csv' % name, 'wb')

The reason your code doesn't work is because you are trying to % a file, which isn't string formatting, and is also invalid.

Build and Install unsigned apk on device without the development server?

You need to manually create the bundle for a debug build.

Bundle debug build:

#React-Native 0.59
react-native bundle --dev false --platform android --entry-file index.js --bundle-output ./android/app/src/main/assets/index.android.bundle --assets-dest ./android/app/src/main/res

#React-Native 0.49.0+
react-native bundle --dev false --platform android --entry-file index.js --bundle-output ./android/app/build/intermediates/assets/debug/index.android.bundle --assets-dest ./android/app/build/intermediates/res/merged/debug

#React-Native 0-0.49.0
react-native bundle --dev false --platform android --entry-file index.android.js --bundle-output ./android/app/build/intermediates/assets/debug/index.android.bundle --assets-dest ./android/app/build/intermediates/res/merged/debug

Then to build the APK's after bundling:

$ cd android
#Create debug build:
$ ./gradlew assembleDebug
#Create release build:
$ ./gradlew assembleRelease #Generated `apk` will be located at `android/app/build/outputs/apk`

P.S. Another approach might be to modify gradle scripts.

I want to calculate the distance between two points in Java

Unlike maths-on-paper notation, most programming languages (Java included) need a * sign to do multiplication. Your distance calculation should therefore read:

distance = Math.sqrt((x1-x2)*(x1-x2) + (y1-y2)*(y1-y2));

Or alternatively:

distance = Math.sqrt(Math.pow((x1-x2), 2) + Math.pow((y1-y2), 2));

Programmatically get the version number of a DLL

Here's a nice way using a bit of reflection to get a version of a DLL containing a particular class:

var ver = System.Reflection.Assembly.GetAssembly(typeof(!Class!)).GetName().Version;

Just replace !Class! with the name of a class which is defined in the DLL you wish to get the version of.

This is my preferred method because if I move the DLLs around for different deploys I don't have to change the filepath.

Angular - Set headers for every request

After some investigation, I found the final and the most easy way is to extend BaseRequestOptions which I prefer.
The following are the ways I tried and give up for some reason:
1. extend BaseRequestOptions, and add dynamic headers in constructor(). It can not work if I login. It will be created once. So it is not dynamic.
2. extend Http. Same reason as above, I can not add dynamic headers in constructor(). And if I rewrite request(..) method, and set headers, like this:

request(url: string|Request, options?: RequestOptionsArgs): Observable<Response> {
 let token = localStorage.getItem(AppConstants.tokenName);
 if (typeof url === 'string') { // meaning we have to add the token to the options, not in url
  if (!options) {
    options = new RequestOptions({});
  }
  options.headers.set('Authorization', 'token_value');
 } else {
  url.headers.set('Authorization', 'token_value');
 }
 return super.request(url, options).catch(this.catchAuthError(this));
}

You just need to overwrite this method, but not every get/post/put methods.

3.And my preferred solution is extend BaseRequestOptions and overwrite merge() :

@Injectable()
export class AuthRequestOptions extends BaseRequestOptions {

 merge(options?: RequestOptionsArgs): RequestOptions {
  var newOptions = super.merge(options);
  let token = localStorage.getItem(AppConstants.tokenName);
  newOptions.headers.set(AppConstants.authHeaderName, token);
  return newOptions;
 }
}

this merge() function will be called for every request.

Laravel requires the Mcrypt PHP extension

Expanding on @JetLaggy:

After trying again and again to modify .bash_profile with the MAMP directory, I changed the file permissions for the MAMP php directory and was able to get 'which php' to show the proper directory. Trouble was that other functions didn't work, such as 'php -v'.

So I updated MAMP. http://documentation.mamp.info/en/mamp/installation/updating-mamp

This did the trick for my particular setup. I had to adjust my PATH to reflect the updated version of PHP, but once I did, everything worked!

Sending intent to BroadcastReceiver from adb

I had the same problem and found out that you have to escape spaces in the extra:

adb shell am broadcast -a com.whereismywifeserver.intent.TEST --es sms_body "test\ from\ adb"

So instead of "test from adb" it should be "test\ from\ adb"

How to regex in a MySQL query

In my case (Oracle), it's WHERE REGEXP_LIKE(column, 'regex.*'). See here:

SQL Function

Description


REGEXP_LIKE

This function searches a character column for a pattern. Use this function in the WHERE clause of a query to return rows matching the regular expression you specify.

...

REGEXP_REPLACE

This function searches for a pattern in a character column and replaces each occurrence of that pattern with the pattern you specify.

...

REGEXP_INSTR

This function searches a string for a given occurrence of a regular expression pattern. You specify which occurrence you want to find and the start position to search from. This function returns an integer indicating the position in the string where the match is found.

...

REGEXP_SUBSTR

This function returns the actual substring matching the regular expression pattern you specify.

(Of course, REGEXP_LIKE only matches queries containing the search string, so if you want a complete match, you'll have to use '^$' for a beginning (^) and end ($) match, e.g.: '^regex.*$'.)

How can I remove an element from a list, with lodash?

There are four ways to do this as I know

const array = [{id:1,name:'Jim'},{id:2,name:'Parker'}];
const toDelete = 1;

The first:

_.reject(array, {id:toDelete})

The second one is :

_.remove(array, {id:toDelete})

In this way the array will be mutated.

The third one is :

_.differenceBy(array,[{id:toDelete}],'id')
// If you can get remove item 
// _.differenceWith(array,[removeItem])

The last one is:

_.filter(array,({id})=>id!==toDelete)

I am learning lodash

Answer to make a record, so that I can find it later.

How to filter empty or NULL names in a QuerySet?

To avoid common mistakes when using exclude, remember:

You can not add multiple conditions into an exclude() block like filter. To exclude multiple conditions, you must use multiple exclude()

Example

Incorrect:

User.objects.filter(email='[email protected]').exclude(profile__nick_name='', profile__avt='')

Correct:

User.objects.filter(email='[email protected]').exclude(profile__nick_name='').exclude(profile__avt='')

Why does Git tell me "No such remote 'origin'" when I try to push to origin?

I faced this issue when I was tring to link a locally created repo with a blank repo on github. Initially I was trying git remote set-url but I had to do git remote add instead.

git remote add origin https://github.com/VijayNew/NewExample.git

Process to convert simple Python script into Windows executable

i would recommend going to http://sourceforge.net/projects/py2exe/files/latest/download?source=files to download py2exe. Then make a python file named setup.py. Inside it, type

from distutils.core import setup
import py2exe
setup(console=['nameoffile.py'])

Save in your user folder Also save the file you want converted in that same folder

Run window's command prompt type in setup.py install py2exe

It should print many lines of code...

Next, open the dist folder.

Run the exe file.

If there are needed files for the program to work, move them to the folder

Copy/Send the dist folder to person.

Optional: Change the name of the dist folder

Hope it works!:)

how to convert binary string to decimal?

ES6 supports binary numeric literals for integers, so if the binary string is immutable, as in the example code in the question, one could just type it in as it is with the prefix 0b or 0B:

var binary = 0b1101000; // code for 104
console.log(binary); // prints 104

How to make bootstrap column height to 100% row height?

@Alan's answer will do what you're looking for, but this solution fails when you use the responsive capabilities of Bootstrap. In your case, you're using the xs sizes so you won't notice, but if you used anything else (e.g. col-sm, col-md, etc), you'd understand.

Another approach is to play with margins and padding. See the updated fiddle: http://jsfiddle.net/jz8j247x/1/

.left-side {
  background-color: blue;
  padding-bottom: 1000px;
  margin-bottom: -1000px;
  height: 100%;
}
.something {
  height: 100%;
  background-color: red;
  padding-bottom: 1000px;
  margin-bottom: -1000px;
  height: 100%;
}
.row {
  background-color: green;
  overflow: hidden;
}

SQL Server: Difference between PARTITION BY and GROUP BY

It provides rolled-up data without rolling up

i.e. Suppose I want to return the relative position of sales region

Using PARTITION BY, I can return the sales amount for a given region and the MAX amount across all sales regions in the same row.

This does mean you will have repeating data, but it may suit the end consumer in the sense that data has been aggregated but no data has been lost - as would be the case with GROUP BY.

MySql server startup error 'The server quit without updating PID file '

Try this..

  1. Navigate to the problem's parent directory cd YOURPATH/usr/local/mysql
  2. rm -rf *.local.err (deletes file)
  3. touch YOURUSERNAME.local.pid (generates new *.local.pid file the error thrown was complaining about)
  4. cd back into your project and restart mysql using mysql.server start

How can I open a Shell inside a Vim Window?

Well it depends on your OS - actually I did not test it on MS Windows - but Conque is one of the best plugins out there.

Actually, it can be better, but works.

How to open warning/information/error dialog in Swing?

See How to Make Dialogs.

You can use:

JOptionPane.showMessageDialog(frame, "Eggs are not supposed to be green.");

And you can also change the symbol to an error message or an warning. E.g see JOptionPane Features.

How to find controls in a repeater header or footer

The best and clean way to do this is within the Item_Created Event :

 protected void rptSummary_ItemCreated(Object sender, RepeaterItemEventArgs e)
        {
            switch (e.Item.ItemType)
            {
                case ListItemType.AlternatingItem:
                    break;
                case ListItemType.EditItem:
                    break;
                case ListItemType.Footer:
                    e.Item.FindControl(ctrl);
                    break;
                case ListItemType.Header:
                    break;
                case ListItemType.Item:
                    break;
                case ListItemType.Pager:
                    break;
                case ListItemType.SelectedItem:
                    break;
                case ListItemType.Separator:
                    break;
                default:
                    break;
            }
    }

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

Error loading the SDK when Eclipse starts

Check the

  • Android wear ARM EABI
  • Android wear Intel x86

Than delete them and restart Eclipse IDE. This should fix the problem.

How to check if an alert exists using WebDriver?

I found catching exception of driver.switchTo().alert(); is so slow in Firefox (FF V20 & selenium-java-2.32.0).`

So I choose another way:

    private static boolean isDialogPresent(WebDriver driver) {
        try {
            driver.getTitle();
            return false;
        } catch (UnhandledAlertException e) {
            // Modal dialog showed
            return true;
        }
    }

And it's a better way when most of your test cases is NO dialog present (throwing exception is expensive).

Are the PUT, DELETE, HEAD, etc methods available in most web browsers?

No. The HTML 5 spec mentions:

The method and formmethod content attributes are enumerated attributes with the following keywords and states:

The keyword get, mapping to the state GET, indicating the HTTP GET method. The GET method should only request and retrieve data and should have no other effect.

The keyword post, mapping to the state POST, indicating the HTTP POST method. The POST method requests that the server accept the submitted form's data to be processed, which may result in an item being added to a database, the creation of a new web page resource, the updating of the existing page, or all of the mentioned outcomes.

The keyword dialog, mapping to the state dialog, indicating that submitting the form is intended to close the dialog box in which the form finds itself, if any, and otherwise not submit.

The invalid value default for these attributes is the GET state

I.e. HTML forms only support GET and POST as HTTP request methods. A workaround for this is to tunnel other methods through POST by using a hidden form field which is read by the server and the request dispatched accordingly.

However, GET, POST, PUT and DELETE are supported by the implementations of XMLHttpRequest (i.e. AJAX calls) in all the major web browsers (IE, Firefox, Safari, Chrome, Opera).

Java String to JSON conversion

Instead of JSONObject , you can use ObjectMapper to convert java object to json string

ObjectMapper mapper = new ObjectMapper();
String requestBean = mapper.writeValueAsString(yourObject);

Customize the Authorization HTTP header

You can create your own custom auth schemas that use the Authorization: header - for example, this is how OAuth works.

As a general rule, if servers or proxies don't understand the values of standard headers, they will leave them alone and ignore them. It is creating your own header keys that can often produce unexpected results - many proxies will strip headers with names they don't recognise.

Having said that, it is possibly a better idea to use cookies to transmit the token, rather than the Authorization: header, for the simple reason that cookies were explicitly designed to carry custom values, whereas the specification for HTTP's built in auth methods does not really say either way - if you want to see exactly what it does say, have a look here.

The other point about this is that many HTTP client libraries have built-in support for Digest and Basic auth but may make life more difficult when trying to set a raw value in the header field, whereas they will all provide easy support for cookies and will allow more or less any value within them.

How to troubleshoot an "AttributeError: __exit__" in multiproccesing in Python?

The reason behind this error is : Flask app is already running, hasn't shut down and in middle of that we try to start another instance by: with app.app_context(): #Code Before we use this with statement we need to make sure that scope of the previous running app is closed.

Taking inputs with BufferedReader in Java

BufferedReader#read reads single character[0 to 65535 (0x00-0xffff)] from the stream, so it is not possible to read single integer from stream.

            String s= inp.readLine();
            int[] m= new int[2];
            String[] s1 = inp.readLine().split(" ");
            m[0]=Integer.parseInt(s1[0]);
            m[1]=Integer.parseInt(s1[1]);

            // Checking whether I am taking the inputs correctly
            System.out.println(s);
            System.out.println(m[0]);
            System.out.println(m[1]);

You can check also Scanner vs. BufferedReader.

Disabling of EditText in Android

Set this in your XML code, It works.

android:focusableInTouchMode="false"

Cookies vs. sessions

when you save the #ID as the cookie to recognize logged in users, you actually are showing data to users that is not related to them. In addition, if a third party tries to set random IDs as cookie data in their browser, they will be able to convince the server that they are a user while they actually are not. That's a lack of security.

You have used cookies, and as you said you have already completed most of the project. besides cookie has the privilege of remaining for a long time, while sessions end more quickly. So sessions are not suitable in this case. In reality many famous and popular websites and services use cookie and you can stay logged-in for a long time. But how can you use their method to create a safer log-in process?

here's the idea: you can help the way you use cookies: If you use random keys instead of IDs to recognize logged-in users, first, you don't leak your primary data to random users, and second, If you consider the Random key large enough, It will be harder for anyone to guess a key or create a random one. for example you can save a 40 length key like this in User's browser: "KUYTYRFU7987gJHFJ543JHBJHCF5645UYTUYJH54657jguthfn" and it will be less likely for anyone to create the exact key and pretend to be someone else.

Java: Difference between the setPreferredSize() and setSize() methods in components

IIRC ...

setSize sets the size of the component.

setPreferredSize sets the preferred size. The Layoutmanager will try to arrange that much space for your component.

It depends on whether you're using a layout manager or not ...

Best way to check function arguments?

def someFunc(a, b, c):
    params = locals()
    for _item in params:
        print type(params[_item]), _item, params[_item]

Demo:

>> someFunc(1, 'asd', 1.0)
>> <type 'int'> a 1
>> <type 'float'> c 1.0
>> <type 'str'> b asd

more about locals()

Difference between Activity Context and Application Context

The reason I think is that ProgressDialog is attached to the activity that props up the ProgressDialog as the dialog cannot remain after the activity gets destroyed so it needs to be passed this(ActivityContext) that also gets destroyed with the activity whereas the ApplicationContext remains even after the activity gets destroyed.

How to clear input buffer in C?

Try this:

stdin->_IO_read_ptr = stdin->_IO_read_end;

Split Spark Dataframe string column into multiple columns

Here's a solution to the general case that doesn't involve needing to know the length of the array ahead of time, using collect, or using udfs. Unfortunately this only works for spark version 2.1 and above, because it requires the posexplode function.

Suppose you had the following DataFrame:

df = spark.createDataFrame(
    [
        [1, 'A, B, C, D'], 
        [2, 'E, F, G'], 
        [3, 'H, I'], 
        [4, 'J']
    ]
    , ["num", "letters"]
)
df.show()
#+---+----------+
#|num|   letters|
#+---+----------+
#|  1|A, B, C, D|
#|  2|   E, F, G|
#|  3|      H, I|
#|  4|         J|
#+---+----------+

Split the letters column and then use posexplode to explode the resultant array along with the position in the array. Next use pyspark.sql.functions.expr to grab the element at index pos in this array.

import pyspark.sql.functions as f

df.select(
        "num",
        f.split("letters", ", ").alias("letters"),
        f.posexplode(f.split("letters", ", ")).alias("pos", "val")
    )\
    .show()
#+---+------------+---+---+
#|num|     letters|pos|val|
#+---+------------+---+---+
#|  1|[A, B, C, D]|  0|  A|
#|  1|[A, B, C, D]|  1|  B|
#|  1|[A, B, C, D]|  2|  C|
#|  1|[A, B, C, D]|  3|  D|
#|  2|   [E, F, G]|  0|  E|
#|  2|   [E, F, G]|  1|  F|
#|  2|   [E, F, G]|  2|  G|
#|  3|      [H, I]|  0|  H|
#|  3|      [H, I]|  1|  I|
#|  4|         [J]|  0|  J|
#+---+------------+---+---+

Now we create two new columns from this result. First one is the name of our new column, which will be a concatenation of letter and the index in the array. The second column will be the value at the corresponding index in the array. We get the latter by exploiting the functionality of pyspark.sql.functions.expr which allows us use column values as parameters.

df.select(
        "num",
        f.split("letters", ", ").alias("letters"),
        f.posexplode(f.split("letters", ", ")).alias("pos", "val")
    )\
    .drop("val")\
    .select(
        "num",
        f.concat(f.lit("letter"),f.col("pos").cast("string")).alias("name"),
        f.expr("letters[pos]").alias("val")
    )\
    .show()
#+---+-------+---+
#|num|   name|val|
#+---+-------+---+
#|  1|letter0|  A|
#|  1|letter1|  B|
#|  1|letter2|  C|
#|  1|letter3|  D|
#|  2|letter0|  E|
#|  2|letter1|  F|
#|  2|letter2|  G|
#|  3|letter0|  H|
#|  3|letter1|  I|
#|  4|letter0|  J|
#+---+-------+---+

Now we can just groupBy the num and pivot the DataFrame. Putting that all together, we get:

df.select(
        "num",
        f.split("letters", ", ").alias("letters"),
        f.posexplode(f.split("letters", ", ")).alias("pos", "val")
    )\
    .drop("val")\
    .select(
        "num",
        f.concat(f.lit("letter"),f.col("pos").cast("string")).alias("name"),
        f.expr("letters[pos]").alias("val")
    )\
    .groupBy("num").pivot("name").agg(f.first("val"))\
    .show()
#+---+-------+-------+-------+-------+
#|num|letter0|letter1|letter2|letter3|
#+---+-------+-------+-------+-------+
#|  1|      A|      B|      C|      D|
#|  3|      H|      I|   null|   null|
#|  2|      E|      F|      G|   null|
#|  4|      J|   null|   null|   null|
#+---+-------+-------+-------+-------+

The server committed a protocol violation. Section=ResponseStatusLine ERROR

One way to debug this (and to make sure it is the protocol violation that is causing the problem), is to use Fiddler (Http Web Proxy) and see if the same error occurs. If it doesn't (i.e. Fiddler handled the issue for you) then you should be able to fix it using the UseUnsafeHeaderParsing flag.

If you are looking for a way to set this value programatically see the examples here: http://o2platform.wordpress.com/2010/10/20/dealing-with-the-server-committed-a-protocol-violation-sectionresponsestatusline/

how to convert string to numerical values in mongodb

Using MongoDB 4.0 and newer

You have two options i.e. $toInt or $convert. Using $toInt, follow the example below:

filterDateStage = {
    '$match': {
        'Date': {
            '$gt': '2015-04-01', 
            '$lt': '2015-04-05'
        }
    }
};

groupStage = {
    '$group': {
        '_id': '$PartnerID',
        'total': { '$sum': { '$toInt': '$moop' } }
    }
};

db.getCollection('my_collection').aggregate([
   filterDateStage,
   groupStage
])

If the conversion operation encounters an error, the aggregation operation stops and throws an error. To override this behavior, use $convert instead.

Using $convert

groupStage = {
    '$group': {
        '_id': '$PartnerID',
        'total': { 
            '$sum': { 
                '$convert': { 'input': '$moop', 'to': 'int' }
            } 
        }
    }
};

Using Map/Reduce

With map/reduce you can use javascript functions like parseInt() to do the conversion. As an example, you could define the map function to process each input document: In the function, this refers to the document that the map-reduce operation is processing. The function maps the converted moop string value to the PartnerID for each document and emits the PartnerID and converted moop pair. This is where the javascript native function parseInt() can be applied:

var mapper = function () {
    var x = parseInt(this.moop);
    emit(this.PartnerID, x);
};

Next, define the corresponding reduce function with two arguments keyCustId and valuesMoop. valuesMoop is an array whose elements are the integer moop values emitted by the map function and grouped by keyPartnerID. The function reduces the valuesMoop array to the sum of its elements.

var reducer = function(keyPartnerID, valuesMoop) {
                  return Array.sum(valuesMoop);
              };

db.collection.mapReduce(
    mapper,
    reducer,
    {
        out : "example_results",
        query: { 
            Date: {
                $gt: "2015-04-01", 
                $lt: "2015-04-05"
            }
        }       
    }
 );

 db.example_results.find(function (err, docs) {
    if(err) console.log(err);
    console.log(JSON.stringify(docs));
 });

For example, with the following sample collection of documents:

/* 0 */
{
    "_id" : ObjectId("550c00f81bcc15211016699b"),
    "Date" : "2015-04-04",
    "PartnerID" : "123456",
    "moop" : "1234"
}

/* 1 */
{
    "_id" : ObjectId("550c00f81bcc15211016699c"),
    "Date" : "2015-04-03",
    "PartnerID" : "123456",
    "moop" : "24"
}

/* 2 */
{
    "_id" : ObjectId("550c00f81bcc15211016699d"),
    "Date" : "2015-04-02",
    "PartnerID" : "123457",
    "moop" : "21"
}

/* 3 */
{
    "_id" : ObjectId("550c00f81bcc15211016699e"),
    "Date" : "2015-04-02",
    "PartnerID" : "123457",
    "moop" : "8"
}

The above Map/Reduce operation will save the results to the example_results collection and the shell command db.example_results.find() will give:

/* 0 */
{
    "_id" : "123456",
    "value" : 1258
}

/* 1 */
{
    "_id" : "123457",
    "value" : 29
}

Failed to find target with hash string 'android-25'

I have got same error for Android-28. In SDK manager - SDK Platform it shows me that Android API 28 is partially installed and no further updates available. so that I updated ANDROID-SDK-BUILD-TOOLS from SDK Tools and after restarting project. It will work. This might be helpful for other who faces same issue as I faced.

Dilemma: when to use Fragments vs Activities:

In my opinion it's not really relevant. The key factor to consider is

  1. how often are you gonna reuse parts of the UI (menus for example),
  2. is the app also for tablets?

The main use of fragments is to build multipane activities, which makes it perfect for Tablet/Phone responsive apps.

Transposing a 2D-array in JavaScript

A library-free implementation in TypeScript that works for any matrix shape that won't truncate your arrays:

const rotate2dArray = <T>(array2d: T[][]) => {
    const rotated2d: T[][] = []

    return array2d.reduce((acc, array1d, index2d) => {
        array1d.forEach((value, index1d) => {
            if (!acc[index1d]) acc[index1d] = []

            acc[index1d][index2d] = value
        })

        return acc
    }, rotated2d)
}

Check table exist or not before create it in Oracle

Please try:

SET SERVEROUTPUT ON
DECLARE
v_emp int:=0;
BEGIN
  SELECT count(*) into v_emp FROM dba_tables where table_name = 'EMPLOYEE'; 

  if v_emp<=0 then
     EXECUTE IMMEDIATE 'create table EMPLOYEE ( ID NUMBER(3), NAME VARCHAR2(30) NOT NULL)';
  end if;
END;

What is the OR operator in an IF statement

The OR operator is a double pipe:

||

So it looks like:

if (this || that) 
{
  //do the other thing
}

EDIT: The reason that your updated attempt isn't working is because the logical operators must separate valid C# expressions. Expressions have operands and operators and operators have an order of precedence.

In your case, the == operator is evaluated first. This means your expression is being evaluated as (title == "User greeting") || "User name". The || gets evaluated next. Since || requires each operand to be a boolean expression, it fails, because your operands are strings.

Using two separate boolean expressions will ensure that your || operator will work properly.

title == "User greeting" || title == "User name"

Difference between Dictionary and Hashtable

ILookup Interface is used in .net 3.5 with linq.

The HashTable is the base class that is weakly type; the DictionaryBase abstract class is stronly typed and uses internally a HashTable.

I found a a strange thing about Dictionary, when we add the multiple entries in Dictionary, the order in which the entries are added is maintained. Thus if I apply a foreach on the Dictionary, I will get the records in the same order I have inserted them.

Whereas, this is not true with normal HashTable, as when I add same records in Hashtable the order is not maintained. As far as my knowledge goes, Dictionary is based on Hashtable, if this is true, why my Dictionary maintains the order but HashTable does not?

As to why they behave differently, it's because Generic Dictionary implements a hashtable, but is not based on System.Collections.Hashtable. The Generic Dictionary implementation is based on allocating key-value-pairs from a list. These are then indexed with the hashtable buckets for random access, but when it returns an enumerator, it just walks the list in sequential order - which will be the order of insertion as long as entries are not re-used.

shiv govind Birlasoft.:)

How to SELECT the last 10 rows of an SQL table which has no ID field?

executing a count(*) query on big data is expensive. i think using "SELECT * FROM table ORDER BY id DESC LIMIT n" where n is your number of rows per page is better and lighter

Send HTML in email via PHP

Sending an html email is not much different from sending normal emails using php. What is necessary to add is the content type along the header parameter of the php mail() function. Here is an example.

<?php
    $to = "[email protected]";
    $subject = "HTML email";
    $message = "
    <html>
    <head>
    <title>HTML email</title>
    </head>
    <body>
    <p>A table as email</p>
    <table>
    <tr>
    <th>Firstname</th>
    <th>Lastname</th>
    </tr>
    <tr>
    <td>Fname</td>
    <td>Sname</td>
    </tr>
    </table>
    </body>
    </html>
    ";
    // Always set content-type when sending HTML email
    $headers = "MIME-Version: 1.0" . "\r\n";
    $headers .= "Content-type:text/html;charset=UTF-8" . "\r\b";
    $headers .= 'From: name' . "\r\n";
    mail($to,$subject,$message,$headers);
?>

You can also check here for more detailed explanations by w3schools

Fixed width buttons with Bootstrap

btn-group-justified and btn-group only work for static content but not on dynamically created buttons, and fixed with of button in css is not practical as it stay on the same width even all content are short.

My solution: put the same class to group of buttons then loop to all of them, get the width of the longest button and apply it to all

var bwidth=0
$("button.btnGroup").each(function(i,v){
    if($(v).width()>bwidth) bwidth=$(v).width();
});
$("button.btnGroup").width(bwidth);

Sample output here

What jsf component can render a div tag?

I think we can you use verbatim tag, as in this tag we use any of the HTML tags

Input button target="_blank" isn't causing the link to load in a new window/tab

In a similar use case, this worked for me...

<button onclick="window.open('https://www.w3.org/', '_blank');">  My Button </button>

How to bind RadioButtons to an enum?

I would use the RadioButtons in a ListBox, and then bind to the SelectedValue.

This is an older thread about this topic, but the base idea should be the same: http://social.msdn.microsoft.com/Forums/en-US/wpf/thread/323d067a-efef-4c9f-8d99-fecf45522395/

jump to line X in nano editor

According to section 2.2 of the manual, you can use the Escape key pressed twice in place of the CTRL key. This allowed me to use Nano's key combination for GO TO LINE when running Nano on a Jupyter/ JupyterHub and accessing through my browser. The normal key combination was getting 'swallowed' as the manual warns about can more often happen with the ALT key on some systems, and which can be replaced by one press of the ESCAPE key.
So for jump to line it was ESCAPE pressed twice, followed by shift key + dash key.

How to do what head, tail, more, less, sed do in Powershell?

I got some better solutions:

gc log.txt -ReadCount 5 | %{$_;throw "pipeline end!"} # head
gc log.txt | %{$num=0;}{$num++;"$num $_"}             # cat -n
gc log.txt | %{$num=0;}{$num++; if($num -gt 2 -and $num -lt 7){"$num $_"}} # sed

How can I clear the terminal in Visual Studio Code?

F1 key opens the shortcuts for me using windows 10. Then type Terminal and you see the clear option.

IIS URL Rewrite and Web.config

Just tried this rule, and it worked with GoDaddy hosting since they've already have the Microsoft URL Rewriting module installed for every IIS 7 account.

<rewrite>
  <rules>
    <rule name="enquiry" stopProcessing="true">
      <match url="^enquiry$" />
      <action type="Rewrite" url="/Enquiry.aspx" />
    </rule>
  </rules>
</rewrite>

Internet Explorer cache location

The location of the Temporary Internet Files folder depends on your version of Windows and whether or not you are using user profiles.

  • If you have Windows Vista, then temporary Internet files are in these locations (note that on your PC they can be on some drive other than C):

    C:\Users[username]\AppData\Local\Microsoft\Windows\Temporary Internet Files\ C:\Users[username]\AppData\Local\Microsoft\Windows\Temporary Internet Files\Low\

    Note that you will have to change the settings of Windows Explorer to show all kinds of files (including the protected system files) in order to access these folders.

  • If you have Windows XP or Windows 2000, then temporary Internet files are in this location (note that on your PC they can be on some drive other than C):

    C:\Documents and Settings[username]\Local Settings\Temporary Internet Files\

    If you have only one user account, then replace [username] with Administrator to get the path of the Temporary Internet Files folder.

  • If you have Windows Me, Windows 98, Windows NT or Windows 95, then index.dat files are in these locations:

    C:\Windows\Temporary Internet Files\
    C:\Windows\Profiles[username]\Temporary Internet Files\

    Note that on your computer, the Windows directory may not be C:\Windows but some other directory. If you don't have a Profiles directory in your Windows directory, don't worry — this just means that you are not using user profiles.

How to add a button programmatically in VBA next to some sheet cell data?

Suppose your function enters data in columns A and B and you want to a custom Userform to appear if the user selects a cell in column C. One way to do this is to use the SelectionChange event:

Private Sub Worksheet_SelectionChange(ByVal Target As Range)
    Dim clickRng As Range
    Dim lastRow As Long

    lastRow = Range("A1").End(xlDown).Row
    Set clickRng = Range("C1:C" & lastRow) //Dynamically set cells that can be clicked based on data in column A

    If Not Intersect(Target, clickRng) Is Nothing Then
        MyUserForm.Show //Launch custom userform
    End If

End Sub

Note that the userform will appear when a user selects any cell in Column C and you might want to populate each cell in Column C with something like "select cell to launch form" to make it obvious that the user needs to perform an action (having a button naturally suggests that it should be clicked)

WCF error - There was no endpoint listening at

I was getting the same error with a service access. It was working in browser, but wasnt working when I try to access it in my asp.net/c# application. I changed application pool from appPoolIdentity to NetworkService, and it start working. Seems like a permission issue to me.

jQuery get mouse position within an element

This solution supports all major browsers including IE. It also takes care of scrolling. First, it retrieves the position of the element relative to the page efficiently, and without using a recursive function. Then it gets the x and y of the mouse click relative to the page and does the subtraction to get the answer which is the position relative to the element (the element can be an image or div for example):

function getXY(evt) {
    var element = document.getElementById('elementId');  //replace elementId with your element's Id.
    var rect = element.getBoundingClientRect();
    var scrollTop = document.documentElement.scrollTop?
                    document.documentElement.scrollTop:document.body.scrollTop;
    var scrollLeft = document.documentElement.scrollLeft?                   
                    document.documentElement.scrollLeft:document.body.scrollLeft;
    var elementLeft = rect.left+scrollLeft;  
    var elementTop = rect.top+scrollTop;

        if (document.all){ //detects using IE   
            x = event.clientX+scrollLeft-elementLeft; //event not evt because of IE
            y = event.clientY+scrollTop-elementTop;
        }
        else{
            x = evt.pageX-elementLeft;
            y = evt.pageY-elementTop;
    }

back button callback in navigationController in iOS

If you can't use "viewWillDisappear" or similar method, try to subclass UINavigationController. This is the header class:

#import <Foundation/Foundation.h>
@class MyViewController;

@interface CCNavigationController : UINavigationController

@property (nonatomic, strong) MyViewController *viewController;

@end

Implementation class:

#import "CCNavigationController.h"
#import "MyViewController.h"

@implementation CCNavigationController {

}
- (UIViewController *)popViewControllerAnimated:(BOOL)animated {
    @"This is the moment for you to do whatever you want"
    [self.viewController doCustomMethod];
    return [super popViewControllerAnimated:animated];
}

@end

In the other hand, you need to link this viewController to your custom NavigationController, so, in your viewDidLoad method for your regular viewController do this:

@implementation MyViewController {
    - (void)viewDidLoad
    {
        [super viewDidLoad];
        ((CCNavigationController*)self.navigationController).viewController = self;
    }
}

Finding all positions of substring in a larger string in C#

using LINQ

public static IEnumerable<int> IndexOfAll(this string sourceString, string subString)
{
    return Regex.Matches(sourceString, subString).Cast<Match>().Select(m => m.Index);
}

Parse XLSX with Node and create json

here's angular 5 method version of this with unminified syntax for those who struggling with that y, z, tt in accepted answer. usage: parseXlsx().subscribe((data)=> {...})

parseXlsx() {
    let self = this;
    return Observable.create(observer => {
        this.http.get('./assets/input.xlsx', { responseType: 'arraybuffer' }).subscribe((data: ArrayBuffer) => {
            const XLSX = require('xlsx');
            let file = new Uint8Array(data);
            let workbook = XLSX.read(file, { type: 'array' });
            let sheetNamesList = workbook.SheetNames;

            let allLists = {};
            sheetNamesList.forEach(function (sheetName) {
                let worksheet = workbook.Sheets[sheetName];
                let currentWorksheetHeaders: object = {};
                let data: Array<any> = [];
                for (let cellName in worksheet) {//cellNames example: !ref,!margins,A1,B1,C1

                    //skipping serviceCells !margins,!ref
                    if (cellName[0] === '!') {
                        continue
                    };

                    //parse colName, rowNumber, and getting cellValue
                    let numberPosition = self.getCellNumberPosition(cellName);
                    let colName = cellName.substring(0, numberPosition);
                    let rowNumber = parseInt(cellName.substring(numberPosition));
                    let cellValue = worksheet[cellName].w;// .w is XLSX property of parsed worksheet

                    //treating '-' cells as empty on Spot Indices worksheet
                    if (cellValue.trim() == "-") {
                        continue;
                    }

                    //storing header column names
                    if (rowNumber == 1 && cellValue) {
                        currentWorksheetHeaders[colName] = typeof (cellValue) == "string" ? cellValue.toCamelCase() : cellValue;
                        continue;
                    }

                    //creating empty object placeholder to store current row
                    if (!data[rowNumber]) {
                        data[rowNumber] = {}
                    };

                    //if header is date - for spot indices headers are dates
                    data[rowNumber][currentWorksheetHeaders[colName]] = cellValue;

                }

                //dropping first two empty rows
                data.shift();
                data.shift();
                allLists[sheetName.toCamelCase()] = data;
            });

            this.parsed = allLists;

            observer.next(allLists);
            observer.complete();
        })
    });
}

What does it mean when MySQL is in the state "Sending data"?

In this state:

The thread is reading and processing rows for a SELECT statement, and sending data to the client.

Because operations occurring during this this state tend to perform large amounts of disk access (reads).

That's why it takes more time to complete and so is the longest-running state over the lifetime of a given query.

A general tree implementation?

anytree

I recommend https://pypi.python.org/pypi/anytree

Example

from anytree import Node, RenderTree

udo = Node("Udo")
marc = Node("Marc", parent=udo)
lian = Node("Lian", parent=marc)
dan = Node("Dan", parent=udo)
jet = Node("Jet", parent=dan)
jan = Node("Jan", parent=dan)
joe = Node("Joe", parent=dan)

print(udo)
Node('/Udo')
print(joe)
Node('/Udo/Dan/Joe')

for pre, fill, node in RenderTree(udo):
    print("%s%s" % (pre, node.name))
Udo
+-- Marc
¦   +-- Lian
+-- Dan
    +-- Jet
    +-- Jan
    +-- Joe

print(dan.children)
(Node('/Udo/Dan/Jet'), Node('/Udo/Dan/Jan'), Node('/Udo/Dan/Joe'))

Features

anytree has also a powerful API with:

  • simple tree creation
  • simple tree modification
  • pre-order tree iteration
  • post-order tree iteration
  • resolve relative and absolute node paths
  • walking from one node to an other.
  • tree rendering (see example above)
  • node attach/detach hookups