Programs & Examples On #Filestream

In .NET framework filestream exposes a Stream around a file, supporting both synchronous and asynchronous read and write operations. ActionScript 3 for AIR 2 and above also uses FileStream, which supports both synchronous and asynchronous read and write operations.

How to append text to a text file in C++?

You need to specify the append open mode like

#include <fstream>

int main() {  
  std::ofstream outfile;

  outfile.open("test.txt", std::ios_base::app); // append instead of overwrite
  outfile << "Data"; 
  return 0;
}

Edit a specific Line of a Text File in C#

I guess the below should work (instead of the writer part from your example). I'm unfortunately with no build environment so It's from memory but I hope it helps

using (var fs = File.Open(filePath, FileMode.Open, FileAccess.ReadWrite)))
        {
            var destinationReader = StreamReader(fs);
            var writer = StreamWriter(fs);
            while ((line = reader.ReadLine()) != null)
            {
              if (line_number == line_to_edit)
                {
                    writer.WriteLine(lineToWrite);
                }
                else
                {
                    destinationReader .ReadLine();
                }
                line_number++;
            }
        }

Encode a FileStream to base64 with c#

You can also encode bytes to Base64. How to get this from a stream see here: How to convert an Stream into a byte[] in C#?

Or I think it should be also possible to use the .ToString() method and encode this.

How to both read and write a file in C#

Don't forget the easy route:

    static void Main(string[] args)
    {
        var text = File.ReadAllText(@"C:\words.txt");
        File.WriteAllText(@"C:\words.txt", text + "DERP");
    }

Returning a stream from File.OpenRead()

Options:

  • Use data.Seek as suggested by ken2k
  • Use the somewhat simpler Position property:

    data.Position = 0;
    
  • Use the ToArray call in MemoryStream to make your life simpler to start with:

    byte[] buf = data.ToArray();
    

The third option would be my preferred approach.

Note that you should have a using statement to close the file stream automatically (and optionally for the MemoryStream), and I'd add a using directive for System.IO to make your code cleaner:

byte[] buf;
using (MemoryStream data = new MemoryStream())
{
    using (Stream file = TestStream())
    {
        file.CopyTo(data);
        buf = data.ToArray();
    }
}

// Use buf

You might also want to create an extension method on Stream to do this for you in one place, e.g.

public static byte[] CopyToArray(this Stream input)
{
    using (MemoryStream memoryStream = new MemoryStream())
    {
        input.CopyTo(memoryStream);
        return memoryStream.ToArray();
    }
}

Note that this doesn't close the input stream.

Access to the path denied error in C#

tl;dr version: Make sure you are not trying to open a file marked in the file system as Read-Only in Read/Write mode.

I have come across this error in my travels trying to read in an XML file. I have found that in some circumstances (detailed below) this error would be generated for a file even though the path and file name are correct.

File details:

  • The path and file name are valid, the file exists
  • Both the service account and the logged in user have Full Control permissions to the file and the full path
  • The file is marked as Read-Only
  • It is running on Windows Server 2008 R2
  • The path to the file was using local drive letters, not UNC path

When trying to read the file programmatically, the following behavior was observed while running the exact same code:

  • When running as the logged in user, the file is read with no error
  • When running as the service account, trying to read the file generates the Access Is Denied error with no details

In order to fix this, I had to change the method call from the default (Opening as RW) to opening the file as RO. Once I made that one change, it stopped throwing an error.

is it possible to evenly distribute buttons across the width of an android linearlayout

The above answers using layout_didn't work for me, but the following did.

<LinearLayout
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:orientation="horizontal"
    android:layout_weight="0.1"
    android:layout_gravity="center_horizontal"
    >

    <android.support.design.widget.FloatingActionButton
        android:layout_width="50dp"
        android:layout_height="50dp"
        android:layout_gravity="center"
       />

    <android.support.design.widget.FloatingActionButton
        android:layout_width="50dp"
        android:layout_height="50dp"
        android:layout_gravity="center"
        android:layout_marginLeft="40dp"
        android:layout_marginStart="40dp"/>

    <android.support.design.widget.FloatingActionButton
        android:layout_width="50dp"
        android:layout_height="50dp"
        android:layout_gravity="center"
        android:layout_marginLeft="40dp"
        android:layout_marginStart="40dp"
        />

    <android.support.design.widget.FloatingActionButton
        android:layout_width="50dp"
        android:layout_height="50dp"
        android:layout_gravity="center"
        android:layout_marginLeft="40dp"
        android:layout_marginStart="40dp"/>

</LinearLayout>

This is how it looks on screen,

enter image description here

How to convert Blob to File in JavaScript

Use saveAs on FileSaver.js github project.

FileSaver.js implements the saveAs() FileSaver interface in browsers that do not natively support it.

Updating version numbers of modules in a multi-module Maven project

The best way is, since you intend to bundle your modules together, you can specify <dependencyManagement> tag in outer most pom.xml (parent module) direct under <project> tag. It controls the version and group name. In your individual module, you just need to specify the <artifactId> tag in your pom.xml. It will take the version from parent file.

How to skip a iteration/loop in while-loop

While you could use a continue, why not just inverse the logic in your if?

while(rs.next())
{
    if(!f.exists() || f.isDirectory()){
    //proceed
    }
}

You don't even need an else {continue;} as it will continue anyway if the if conditions are not satisfied.

How can I use async/await at the top level?

Since main() runs asynchronously it returns a promise. You have to get the result in then() method. And because then() returns promise too, you have to call process.exit() to end the program.

main()
   .then(
      (text) => { console.log('outside: ' + text) },
      (err)  => { console.log(err) }
   )
   .then(() => { process.exit() } )

How to download the latest artifact from Artifactory repository?

You can use the wget --user=USER --password=PASSWORD .. command, but before you can do that, you must allow artifactory to force authentication, which can be done by unchecking the "Hide Existence of Unauthorized Resources" box at Security/General tab in artifactory admin panel. Otherwise artifactory sends a 404 page and wget can not authenticate to artifactory.

Python str vs unicode types

unicode is meant to handle text. Text is a sequence of code points which may be bigger than a single byte. Text can be encoded in a specific encoding to represent the text as raw bytes(e.g. utf-8, latin-1...).

Note that unicode is not encoded! The internal representation used by python is an implementation detail, and you shouldn't care about it as long as it is able to represent the code points you want.

On the contrary str in Python 2 is a plain sequence of bytes. It does not represent text!

You can think of unicode as a general representation of some text, which can be encoded in many different ways into a sequence of binary data represented via str.

Note: In Python 3, unicode was renamed to str and there is a new bytes type for a plain sequence of bytes.

Some differences that you can see:

>>> len(u'à')  # a single code point
1
>>> len('à')   # by default utf-8 -> takes two bytes
2
>>> len(u'à'.encode('utf-8'))
2
>>> len(u'à'.encode('latin1'))  # in latin1 it takes one byte
1
>>> print u'à'.encode('utf-8')  # terminal encoding is utf-8
à
>>> print u'à'.encode('latin1') # it cannot understand the latin1 byte
?

Note that using str you have a lower-level control on the single bytes of a specific encoding representation, while using unicode you can only control at the code-point level. For example you can do:

>>> 'àèìòù'
'\xc3\xa0\xc3\xa8\xc3\xac\xc3\xb2\xc3\xb9'
>>> print 'àèìòù'.replace('\xa8', '')
à?ìòù

What before was valid UTF-8, isn't anymore. Using a unicode string you cannot operate in such a way that the resulting string isn't valid unicode text. You can remove a code point, replace a code point with a different code point etc. but you cannot mess with the internal representation.

How to enable CORS in apache tomcat

CORS support in Tomcat is provided via a filter. You need to add this filter to your web.xml file and configure it to match your requirements. Full details on the configuration options available can be found in the Tomcat Documentation.

Is true == 1 and false == 0 in JavaScript?

Actually every object in javascript resolves to true if it has "a real value" as W3Cschools puts it. That means everything except "", NaN, undefined, null or 0.

Testing a number against a boolean with the == operator indeed is a tad weird, since the boolean gets converted into numerical 1 before comparing, which defies a little bit the logic behind the definition. This gets even more confusing when you do something like this:

_x000D_
_x000D_
    var fred = !!3; // will set fred to true _x000D_
    var joe = !!0; // will set joe to false_x000D_
    alert("fred = "+ fred + ", joe = "+ joe);
_x000D_
_x000D_
_x000D_

not everything in javascript makes a lot of sense ;)

What is an undefined reference/unresolved external symbol error and how do I fix it?

Class members:

A pure virtual destructor needs an implementation.

Declaring a destructor pure still requires you to define it (unlike a regular function):

struct X
{
    virtual ~X() = 0;
};
struct Y : X
{
    ~Y() {}
};
int main()
{
    Y y;
}
//X::~X(){} //uncomment this line for successful definition

This happens because base class destructors are called when the object is destroyed implicitly, so a definition is required.

virtual methods must either be implemented or defined as pure.

This is similar to non-virtual methods with no definition, with the added reasoning that the pure declaration generates a dummy vtable and you might get the linker error without using the function:

struct X
{
    virtual void foo();
};
struct Y : X
{
   void foo() {}
};
int main()
{
   Y y; //linker error although there was no call to X::foo
}

For this to work, declare X::foo() as pure:

struct X
{
    virtual void foo() = 0;
};

Non-virtual class members

Some members need to be defined even if not used explicitly:

struct A
{ 
    ~A();
};

The following would yield the error:

A a;      //destructor undefined

The implementation can be inline, in the class definition itself:

struct A
{ 
    ~A() {}
};

or outside:

A::~A() {}

If the implementation is outside the class definition, but in a header, the methods have to be marked as inline to prevent a multiple definition.

All used member methods need to be defined if used.

A common mistake is forgetting to qualify the name:

struct A
{
   void foo();
};

void foo() {}

int main()
{
   A a;
   a.foo();
}

The definition should be

void A::foo() {}

static data members must be defined outside the class in a single translation unit:

struct X
{
    static int x;
};
int main()
{
    int x = X::x;
}
//int X::x; //uncomment this line to define X::x

An initializer can be provided for a static const data member of integral or enumeration type within the class definition; however, odr-use of this member will still require a namespace scope definition as described above. C++11 allows initialization inside the class for all static const data members.

How to list active connections on PostgreSQL?

Following will give you active connections/ queries in postgres DB-

SELECT 
    pid
    ,datname
    ,usename
    ,application_name
    ,client_hostname
    ,client_port
    ,backend_start
    ,query_start
    ,query
    ,state
FROM pg_stat_activity
WHERE state = 'active';

You may use 'idle' instead of active to get already executed connections/queries.

How to compile C program on command line using MinGW?

Where is your gcc?

My gcc is in "C:\Program Files\CodeBlocks\MinGW\bin\".

"C:\Program Files\CodeBlocks\MinGW\bin\gcc" -c "foo.c"
"C:\Program Files\CodeBlocks\MinGW\bin\gcc" "foo.o" -o "foo 01.exe"

Convert number to month name in PHP

this is trivially easy, why are so many people making such bad suggestions? @Bora was the closest, but this is the most robust

/***
 * returns the month in words for a given month number
 */
date("F", strtotime(date("Y")."-".$month."-01"));

this is the way to do it

'if' in prolog?

The best thing to do is to use the so-called cuts, which has the symbol !.

if_then_else(Condition, Action1, Action2) :- Condition, !, Action1.  
if_then_else(Condition, Action1, Action2) :- Action2.

The above is the basic structure of a condition function.

To exemplify, here's the max function:

max(X,Y,X):-X>Y,!.  
max(X,Y,Y):-Y=<X.

I suggest reading more documentation on cuts, but in general they are like breakpoints. Ex.: In case the first max function returns a true value, the second function is not verified.

PS: I'm fairly new to Prolog, but this is what I've found out.

For loop in Oracle SQL

You are pretty confused my friend. There are no LOOPS in SQL, only in PL/SQL. Here's a few examples based on existing Oracle table - copy/paste to see results:

-- Numeric FOR loop --
set serveroutput on -->> do not use in TOAD --
DECLARE
  k NUMBER:= 0;
BEGIN
  FOR i IN 1..10 LOOP
    k:= k+1;
    dbms_output.put_line(i||' '||k);
 END LOOP;
END;
/

-- Cursor FOR loop --
set serveroutput on
DECLARE
   CURSOR c1 IS SELECT * FROM scott.emp;
   i NUMBER:= 0;
BEGIN
  FOR e_rec IN c1 LOOP
  i:= i+1;
    dbms_output.put_line(i||chr(9)||e_rec.empno||chr(9)||e_rec.ename);
  END LOOP;
END;
/

-- SQL example to generate 10 rows --
SELECT 1 + LEVEL-1 idx
  FROM dual
CONNECT BY LEVEL <= 10
/

Datatables: Cannot read property 'mData' of undefined

One more reason why this happens is because of the columns parameter in the DataTable initialization.

The number of columns has to match with headers

"columns" : [ {
                "width" : "30%"
            }, {
                "width" : "15%"
            }, {
                "width" : "15%"
            }, {
                "width" : "30%"
            } ]

I had 7 columns

<th>Full Name</th>
<th>Phone Number</th>
<th>Vehicle</th>
<th>Home Location</th>
<th>Tags</th>
<th>Current Location</th>
<th>Serving Route</th>

Where is debug.keystore in Android Studio

  • For Windows User: C:\Users\USERNAME\.android\debug.keystore (Replace USERNAME with your actual PC user name)

  • For Linux or Mac OS User: ~/.android/debug.keystore

After you will get SHA1 by below Code using Command Prompt:

  keytool -list -v -keystore "C:\Users\USERNAME\.android\debug.keystore" -alias androiddebugkey -storepass android -keypass android

SSIS Excel Connection Manager failed to Connect to the Source

Here's the solution that works fine for me.

I just Saved the Excel file as an Excel 97-2003 Version. enter image description here

Dictionary text file

There's also WordNet. Its data files format are well-documented.
I used it for building an embeddable dictionary library for iOS developers (www.lexicontext.com) and also in one of my apps.

Pass data to layout that are common to all pages

I do not think any of these answers are flexible enough for a large enterprise level application. I'm not a fan of overusing the ViewBag, but in this case, for flexibility, I'd make an exception. Here's what I'd do...

You should have a base controller on all of your controllers. Add your Layout data OnActionExecuting in your base controller (or OnActionExecuted if you want to defer that)...

public class BaseController : Controller
{
    protected override void OnActionExecuting(ActionExecutingContext     
        filterContext)
    {
        ViewBag.LayoutViewModel = MyLayoutViewModel;
    }
}

public class HomeController : BaseController
{
    public ActionResult Index()
    {
        return View(homeModel);
    }
}

Then in your _Layout.cshtml pull your ViewModel from the ViewBag...

@{
  LayoutViewModel model = (LayoutViewModel)ViewBag.LayoutViewModel;
}

<h1>@model.Title</h1>

Or...

<h1>@ViewBag.LayoutViewModel.Title</h1>

Doing this doesn't interfere with the coding for your page's controllers or view models.

Python - 'ascii' codec can't decode byte

In case you're dealing with Unicode, sometimes instead of encode('utf-8'), you can also try to ignore the special characters, e.g.

"??".encode('ascii','ignore')

or as something.decode('unicode_escape').encode('ascii','ignore') as suggested here.

Not particularly useful in this example, but can work better in other scenarios when it's not possible to convert some special characters.

Alternatively you can consider replacing particular character using replace().

Read input numbers separated by spaces

int main() {
int sum = 0;
cout << "enter number" << endl;
int i = 0;
while (true) {
    cin >> i;
    sum += i;
    //cout << i << endl;
    if (cin.peek() == '\n') {
        break;
    }
    
}

cout << "result: " << sum << endl;
return 0;
}

I think this code works, you may enter any int numbers and spaces, it will calculate the sum of input ints

Rails: call another controller action from a controller

Separate these functions from controllers and put them into model file. Then include the model file in your controller.

How to smooth a curve in the right way?

Another option is to use KernelReg in statsmodels:

from statsmodels.nonparametric.kernel_regression import KernelReg
import numpy as np
import matplotlib.pyplot as plt

x = np.linspace(0,2*np.pi,100)
y = np.sin(x) + np.random.random(100) * 0.2

# The third parameter specifies the type of the variable x;
# 'c' stands for continuous
kr = KernelReg(y,x,'c')
plt.plot(x, y, '+')
y_pred, y_std = kr.fit(x)

plt.plot(x, y_pred)
plt.show()

Int to Char in C#

Although not exactly answering the question as formulated, but if you need or can take the end result as string you can also use

string s = Char.ConvertFromUtf32(56);

which will give you surrogate UTF-16 pairs if needed, protecting you if you are out side of the BMP.

Check if object value exists within a Javascript array of objects and if not add a new object to array

xorWith in Lodash can be used to achieve this

let objects = [ { id: 1, username: 'fred' }, { id: 2, username: 'bill' }, { id: 2, username: 'ted' } ]
let existingObject = { id: 1, username: 'fred' };
let newObject = { id: 1729, username: 'Ramanujan' }

_.xorWith(objects, [existingObject], _.isEqual)
// returns [ { id: 2, username: 'bill' }, { id: 2, username: 'ted' } ]

_.xorWith(objects, [newObject], _.isEqual)
// returns [ { id: 1, username: 'fred' }, { id: 2, username: 'bill' }, { id: 2, username: 'ted' } ,{ id: 1729, username: 'Ramanujan' } ]

iOS 7's blurred overlay effect using CSS?

[Edit] In the future (mobile) Safari 9 there will be -webkit-backdrop-filter for exactly this. See this pen I made to showcase it.

I thought about this for the last 4 weeks and came up with this solution.

Live Demo

[Edit] I wrote a more indepth post on CSS-Tricks

This technique is using CSS Regions so the browser support is not the best at this moment. (http://caniuse.com/#feat=css-regions)

The key part of this technique is to split apart content from layout by using CSS Region. First define a .content element with flow-into:content and then use the appropriate structure to blur the header.

The layout structure:

<div class="phone">
 <div class="phone__display">
  <div class="header">
    <div class="header__text">Header</div>
    <div class="header__background"></div>
  </div>
  <div class="phone__content">
  </div>
 </div>
</div>

The two important parts of this layout are .header__background and .phone__content - these are the containers where the content should flow though.

Using CSS Regions it is simple as flow-from:content (.content is flowing into the named region content)

Now comes the tricky part. We want to always flow the content through the .header__background because that is the section where the content will be blured. (using webkit-filter:blur(10px);)

This is done by transfrom:translateY(-$HeightOfTheHeader) the .content to ensure that the content will always flow though the .header__background. This transform while always hide some content beneath the header. Fixing this is ease adding

.header__background:before{
  display:inline-block;
  content:'';
  height:$HeightOfTheHEader
}

to accommodate for the transform.

This is currently working in:

  • Chrome 29+ (enable 'experimental-webkit-features'/'enable-experimental-web-platform-features')
  • Safari 6.1 Seed 6
  • iOS7 (slow and no scrolling)

mysql -> insert into tbl (select from another table) and some default values

INSERT INTO def (field_1, field_2, field3) 
VALUES 
('$field_1', (SELECT id_user from user_table where name = 'jhon'), '$field3')

failed to open stream: HTTP wrapper does not support writeable connections

Instead of doing file_put_contents(***WebSiteURL***...) you need to use the server path to /cache/lang/file.php (e.g. /home/content/site/folders/filename.php).

You cannot open a file over HTTP and expect it to be written. Instead you need to open it using the local path.

Batch Files - Error Handling

Other than ERRORLEVEL, batch files have no error handling. You'd want to look at a more powerful scripting language. I've been moving code to PowerShell.

The ability to easily use .Net assemblies and methods was one of the major reasons I started with PowerShell. The improved error handling was another. The fact that Microsoft is now requiring all of its server programs (Exchange, SQL Server etc) to be PowerShell drivable was pure icing on the cake.

Right now, it looks like any time invested in learning and using PowerShell will be time well spent.

How do I find the difference between two values without knowing which is larger?

If you plan to use the signed distance calculation snippet posted by phi (like I did) and your b might have value 0, you probably want to fix the code as described below:

import math

def distance(a, b):
    if (a == b):
        return 0
    elif (a < 0) and (b < 0) or (a > 0) and (b >= 0): # fix: b >= 0 to cover case b == 0
        if (a < b):
            return (abs(abs(a) - abs(b)))
        else:
            return -(abs(abs(a) - abs(b)))
    else:
        return math.copysign((abs(a) + abs(b)),b)

The original snippet does not work correctly regarding sign when a > 0 and b == 0.

SQL Error: ORA-00942 table or view does not exist

Here is an answer: http://www.dba-oracle.com/concepts/synonyms.htm

An Oracle synonym basically allows you to create a pointer to an object that exists somewhere else. You need Oracle synonyms because when you are logged into Oracle, it looks for all objects you are querying in your schema (account). If they are not there, it will give you an error telling you that they do not exist.

How to add reference to a method parameter in javadoc?

I guess you could write your own doclet or taglet to support this behaviour.

Taglet Overview

Doclet Overview

How to get raw text from pdf file using java

Hi we can extract the pdf files using Apache Tika

The Example is :

import java.io.IOException;
import java.io.InputStream;
import java.util.HashMap;
import java.util.Map;
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.tika.metadata.Metadata;
import org.apache.tika.metadata.TikaCoreProperties;
import org.apache.tika.parser.AutoDetectParser;
import org.apache.tika.parser.ParseContext;
import org.apache.tika.sax.BodyContentHandler;

public class WebPagePdfExtractor {

    public Map<String, Object> processRecord(String url) {
        DefaultHttpClient httpclient = new DefaultHttpClient();
        Map<String, Object> map = new HashMap<String, Object>();
        try {
            HttpGet httpGet = new HttpGet(url);
            HttpResponse response = httpclient.execute(httpGet);
            HttpEntity entity = response.getEntity();
            InputStream input = null;
            if (entity != null) {
                try {
                    input = entity.getContent();
                    BodyContentHandler handler = new BodyContentHandler();
                    Metadata metadata = new Metadata();
                    AutoDetectParser parser = new AutoDetectParser();
                    ParseContext parseContext = new ParseContext();
                    parser.parse(input, handler, metadata, parseContext);
                    map.put("text", handler.toString().replaceAll("\n|\r|\t", " "));
                    map.put("title", metadata.get(TikaCoreProperties.TITLE));
                    map.put("pageCount", metadata.get("xmpTPg:NPages"));
                    map.put("status_code", response.getStatusLine().getStatusCode() + "");
                } catch (Exception e) {
                    e.printStackTrace();
                } finally {
                    if (input != null) {
                        try {
                            input.close();
                        } catch (IOException e) {
                            e.printStackTrace();
                        }
                    }
                }
            }
        } catch (Exception exception) {
            exception.printStackTrace();
        }
        return map;
    }

    public static void main(String arg[]) {
        WebPagePdfExtractor webPagePdfExtractor = new WebPagePdfExtractor();
        Map<String, Object> extractedMap = webPagePdfExtractor.processRecord("http://math.about.com/library/q20.pdf");
        System.out.println(extractedMap.get("text"));
    }

}

How to put spacing between floating divs?

You can do the following:

Assuming your container div has a class "yellow".

.yellow div {
    // Apply margin to every child in this container
    margin: 10px;
}

.yellow div:first-child, .yellow div:nth-child(3n+1) {
    // Remove the margin on the left side on the very first and then every fourth element (for example)
    margin-left: 0;
}

.yellow div:last-child {
    // Remove the right side margin on the last element
    margin-right: 0;
}

The number 3n+1 equals every fourth element outputted and will clearly only work if you know how many will be displayed in a row, but it should illustrate the example. More details regarding nth-child here.

Note: For :first-child to work in IE8 and earlier, a <!DOCTYPE> must be declared.

Note2: The :nth-child() selector is supported in all major browsers, except IE8 and earlier.

What are access specifiers? Should I inherit with private, protected or public?

what are Access Specifiers?

There are 3 access specifiers for a class/struct/Union in C++. These access specifiers define how the members of the class can be accessed. Of course, any member of a class is accessible within that class(Inside any member function of that same class). Moving ahead to type of access specifiers, they are:

Public - The members declared as Public are accessible from outside the Class through an object of the class.

Protected - The members declared as Protected are accessible from outside the class BUT only in a class derived from it.

Private - These members are only accessible from within the class. No outside Access is allowed.

An Source Code Example:

class MyClass
{
    public:
        int a;
    protected:
        int b;
    private:
        int c;
};

int main()
{
    MyClass obj;
    obj.a = 10;     //Allowed
    obj.b = 20;     //Not Allowed, gives compiler error
    obj.c = 30;     //Not Allowed, gives compiler error
}

Inheritance and Access Specifiers

Inheritance in C++ can be one of the following types:

  • Private Inheritance
  • Public Inheritance
  • Protected inheritance

Here are the member access rules with respect to each of these:

First and most important rule Private members of a class are never accessible from anywhere except the members of the same class.

Public Inheritance:

All Public members of the Base Class become Public Members of the derived class &
All Protected members of the Base Class become Protected Members of the Derived Class.

i.e. No change in the Access of the members. The access rules we discussed before are further then applied to these members.

Code Example:

Class Base
{
    public:
        int a;
    protected:
        int b;
    private:
        int c;
};

class Derived:public Base
{
    void doSomething()
    {
        a = 10;  //Allowed 
        b = 20;  //Allowed
        c = 30;  //Not Allowed, Compiler Error
    }
};

int main()
{
    Derived obj;
    obj.a = 10;  //Allowed
    obj.b = 20;  //Not Allowed, Compiler Error
    obj.c = 30;  //Not Allowed, Compiler Error

}

Private Inheritance:

All Public members of the Base Class become Private Members of the Derived class &
All Protected members of the Base Class become Private Members of the Derived Class.

An code Example:

Class Base
{
    public:
      int a;
    protected:
      int b;
    private:
      int c;
};

class Derived:private Base   //Not mentioning private is OK because for classes it  defaults to private 
{
    void doSomething()
    {
        a = 10;  //Allowed 
        b = 20;  //Allowed
        c = 30;  //Not Allowed, Compiler Error
    }
};

class Derived2:public Derived
{
    void doSomethingMore()
    {
        a = 10;  //Not Allowed, Compiler Error, a is private member of Derived now
        b = 20;  //Not Allowed, Compiler Error, b is private member of Derived now
        c = 30;  //Not Allowed, Compiler Error
    }
};

int main()
{
    Derived obj;
    obj.a = 10;  //Not Allowed, Compiler Error
    obj.b = 20;  //Not Allowed, Compiler Error
    obj.c = 30;  //Not Allowed, Compiler Error

}

Protected Inheritance:

All Public members of the Base Class become Protected Members of the derived class &
All Protected members of the Base Class become Protected Members of the Derived Class.

A Code Example:

Class Base
{
    public:
        int a;
    protected:
        int b;
    private:
        int c;
};

class Derived:protected Base  
{
    void doSomething()
    {
        a = 10;  //Allowed 
        b = 20;  //Allowed
        c = 30;  //Not Allowed, Compiler Error
    }
};

class Derived2:public Derived
{
    void doSomethingMore()
    {
        a = 10;  //Allowed, a is protected member inside Derived & Derived2 is public derivation from Derived, a is now protected member of Derived2
        b = 20;  //Allowed, b is protected member inside Derived & Derived2 is public derivation from Derived, b is now protected member of Derived2
        c = 30;  //Not Allowed, Compiler Error
    }
};

int main()
{
    Derived obj;
    obj.a = 10;  //Not Allowed, Compiler Error
    obj.b = 20;  //Not Allowed, Compiler Error
    obj.c = 30;  //Not Allowed, Compiler Error
}

Remember the same access rules apply to the classes and members down the inheritance hierarchy.


Important points to note:

- Access Specification is per-Class not per-Object

Note that the access specification C++ work on per-Class basis and not per-object basis.
A good example of this is that in a copy constructor or Copy Assignment operator function, all the members of the object being passed can be accessed.

- A Derived class can only access members of its own Base class

Consider the following code example:

class Myclass
{ 
    protected: 
       int x; 
}; 

class derived : public Myclass
{
    public: 
        void f( Myclass& obj ) 
        { 
            obj.x = 5; 
        } 
};

int main()
{
    return 0;
}

It gives an compilation error:

prog.cpp:4: error: ‘int Myclass::x’ is protected

Because the derived class can only access members of its own Base Class. Note that the object obj being passed here is no way related to the derived class function in which it is being accessed, it is an altogether different object and hence derived member function cannot access its members.


What is a friend? How does friend affect access specification rules?

You can declare a function or class as friend of another class. When you do so the access specification rules do not apply to the friended class/function. The class or function can access all the members of that particular class.

So do friends break Encapsulation?

No they don't, On the contrary they enhance Encapsulation!

friendship is used to indicate a intentional strong coupling between two entities.
If there exists a special relationship between two entities such that one needs access to others private or protected members but You do not want everyone to have access by using the public access specifier then you should use friendship.

How to fill DataTable with SQL Table

You need to modify the method GetData() and add your "experimental" code there, and return t1.

phpMyAdmin - Error > Incorrect format parameter?

I was able to resolve this by following the steps posted here: xampp phpmyadmin, Incorrect format parameter

Because I'm not using XAMPP, I also needed to update my php.ini.default to php.ini which finally did the trick.

Getting char from string at specified index

char = split_string_to_char(text)(index)

------

Function split_string_to_char(text) As String()

   Dim chars() As String
   For char_count = 1 To Len(text)
      ReDim Preserve chars(char_count - 1)
      chars(char_count - 1) = Mid(text, char_count, 1)
   Next
   split_string_to_char = chars
End Function

Access to the path is denied

The following tip isn't an answer to this thread's original question, but might help some other users who end up on this webpage, after making the same stupid mistake I just did...

I was attempting to get an ASP.Net FileUpload control to upload it's file to a network address which contained a "hidden share", namely:

\MyNetworkServer\c$\SomeDirectoryOrOther

I didn't understand it. If I ran the webpage in Debug mode in Visual Studio, it'd work fine. But when the project was deployed, and was running via an Application Pool user, it refused to find this network directory.

I had checked which user my IIS site was running under, gave this user full permissions to this directory on the "MyNetworkServer" server, etc etc, but nothing worked.

The reason (of course!) is that only Administrators are able to "see" these hidden drive shares.

My solution was simply to create a "normal" share to

\MyNetworkServer\SomeDirectoryOrOther

and this got rid of the "Access to the path... is denied" error. The FileUpload was able to successfully run the command

fileUpload.SaveAs(networkFilename);

Hope this helps some other users who make the same mistake I did !

Note also that if you're uploading large files (over 4Mb), then IIS7 requires that you modify the web.config file in two places. Click on this link to read what you need to do: Uploading large files in ASP.Net

Retrieving Android API version programmatically

As described in the Android documentation, the SDK level (integer) the phone is running is available in:

android.os.Build.VERSION.SDK_INT

The class corresponding to this int is in the android.os.Build.VERSION_CODES class.

Code example:

if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.LOLLIPOP){
    // Do something for lollipop and above versions
} else{
    // do something for phones running an SDK before lollipop
}

Edit: This SDK_INT is available since Donut (android 1.6 / API4) so make sure your application is not retro-compatible with Cupcake (android 1.5 / API3) when you use it or your application will crash (thanks to Programmer Bruce for the precision).

Corresponding android documentation is here and here

C# Java HashMap equivalent

the answer is

Dictionary

take look at my function, its simple add uses most important member functions inside Dictionary

this function return false if the list contain Duplicates items

 public static bool HasDuplicates<T>(IList<T> items)
    {
        Dictionary<T, bool> mp = new Dictionary<T, bool>();
        for (int i = 0; i < items.Count; i++)
        {
            if (mp.ContainsKey(items[i]))
            {
                return true; // has duplicates
            }
            mp.Add(items[i], true);
        }
        return false; // no duplicates
    }

Most efficient way to reverse a numpy array

As mentioned above, a[::-1] really only creates a view, so it's a constant-time operation (and as such doesn't take longer as the array grows). If you need the array to be contiguous (for example because you're performing many vector operations with it), ascontiguousarray is about as fast as flipud/fliplr:

enter image description here


Code to generate the plot:

import numpy
import perfplot


perfplot.show(
    setup=lambda n: numpy.random.randint(0, 1000, n),
    kernels=[
        lambda a: a[::-1],
        lambda a: numpy.ascontiguousarray(a[::-1]),
        lambda a: numpy.fliplr([a])[0],
    ],
    labels=["a[::-1]", "ascontiguousarray(a[::-1])", "fliplr"],
    n_range=[2 ** k for k in range(25)],
    xlabel="len(a)",
)

Download Excel file via AJAX MVC

I used the solution posted by CSL but I would recommend you dont store the file data in Session during the whole session. By using TempData the file data is automatically removed after the next request (which is the GET request for the file). You could also manage removal of the file data in Session in download action.

Session could consume much memory/space depending on SessionState storage and how many files are exported during the session and if you have many users.

I've updated the serer side code from CSL to use TempData instead.

public ActionResult PostReportPartial(ReportVM model){

   // Validate the Model is correct and contains valid data
   // Generate your report output based on the model parameters
   // This can be an Excel, PDF, Word file - whatever you need.

   // As an example lets assume we've generated an EPPlus ExcelPackage

   ExcelPackage workbook = new ExcelPackage();
   // Do something to populate your workbook

   // Generate a new unique identifier against which the file can be stored
   string handle = Guid.NewGuid().ToString()

   using(MemoryStream memoryStream = new MemoryStream()){
        workbook.SaveAs(memoryStream);
        memoryStream.Position = 0;
        TempData[handle] = memoryStream.ToArray();
   }      

   // Note we are returning a filename as well as the handle
   return new JsonResult() { 
         Data = new { FileGuid = handle, FileName = "TestReportOutput.xlsx" }
   };

}

[HttpGet]
public virtual ActionResult Download(string fileGuid, string fileName)
{   
   if(TempData[fileGuid] != null){
        byte[] data = TempData[fileGuid] as byte[];
        return File(data, "application/vnd.ms-excel", fileName);
   }   
   else{
        // Problem - Log the error, generate a blank file,
        //           redirect to another controller action - whatever fits with your application
        return new EmptyResult();
   }
}

How can I find the latitude and longitude from address?

Ud_an's solution with updated API's

Note: LatLng class is part of Google Play Services.

Mandatory:

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

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

Update: If you have target SDK 23 and above, make sure you take care of runtime permission for location.

public LatLng getLocationFromAddress(Context context,String strAddress) {

    Geocoder coder = new Geocoder(context);
    List<Address> address;
    LatLng p1 = null;

    try {
        // May throw an IOException
        address = coder.getFromLocationName(strAddress, 5);
        if (address == null) {
            return null;
        }

        Address location = address.get(0);
        p1 = new LatLng(location.getLatitude(), location.getLongitude() );

    } catch (IOException ex) {

        ex.printStackTrace();
    }

    return p1;
}

How to import RecyclerView for Android L-preview

I used this one is working for me. One thing needs to be consider that what appcompat version you are using. I am using appcompat-v7:26.+ so this is working for me.

implementation 'com.android.support:recyclerview-v7:26.+'

Java random numbers using a seed

If you'd want to generate multiple numbers using one seed you can do something like this:

public double[] GenerateNumbers(long seed, int amount) {
    double[] randomList = new double[amount];
    for (int i=0;i<amount;i++) {
        Random generator = new Random(seed);
        randomList[i] = Math.abs((double) (generator.nextLong() % 0.001) * 10000);
        seed--;
    }
    return randomList;
}

It will display the same list if you use the same seed.

Convert a list of objects to an array of one of the object's properties

For everyone who is stuck with .NET 2.0, like me, try the following way (applicable to the example in the OP):

ConfigItemList.ConvertAll<string>(delegate (ConfigItemType ci) 
{ 
   return ci.Name; 
}).ToArray();

where ConfigItemList is your list variable.

Adding a newline character within a cell (CSV)

I was concatenating the variable and adding multiple items in same row. so below code work for me. "\n" new line code is mandatory to add first and last of each line if you will add it on last only it will append last 1-2 character to new lines.

  $itemCode =  '';
foreach($returnData['repairdetail'] as $checkkey=>$repairDetailData){

    if($checkkey >0){
        $itemCode   .= "\n".trim(@$repairDetailData['ItemMaster']->Item_Code)."\n";
    }else{
        $itemCode   .= "\n".trim(@$repairDetailData['ItemMaster']->Item_Code)."\n";             
    }
    $repairDetaile[]= array(
        $itemCode,
    )
}
// pass all array to here 
foreach ($repairDetaile as $csvData) { 
    fputcsv($csv_file,$csvData,',','"');
}
fclose($csv_file);  

Passing html values into javascript functions

Give the textbox an id of "txtValue" and change the input button declaration to the following:

<input type="button" value="submit" onclick="verifyorder(document.getElementById('txtValue').value)" />

How to sort a list of lists by a specific index of the inner list?

I think lambda function can solve your problem.

old_list = [[0,1,'f'], [4,2,'t'],[9,4,'afsd']]

#let's assume we want to sort lists by last value ( old_list[2] )
new_list = sorted(old_list, key=lambda x: x[2])

#Resulst of new_list will be:

[[9, 4, 'afsd'], [0, 1, 'f'], [4, 2, 't']]

Are the decimal places in a CSS width respected?

The width will be rounded to an integer number of pixels.

I don't know if every browser will round it the same way though. They all seem to have a different strategy when rounding sub-pixel percentages. If you're interested in the details of sub-pixel rounding in different browsers, there's an excellent article on ElastiCSS.

edit: I tested @Skilldrick's demo in some browsers for the sake of curiosity. When using fractional pixel values (not percentages, they work as suggested in the article I linked) IE9p7 and FF4b7 seem to round to the nearest pixel, while Opera 11b, Chrome 9.0.587.0 and Safari 5.0.3 truncate the decimal places. Not that I hoped that they had something in common after all...

Easy way to write contents of a Java InputStream to an OutputStream

PipedInputStream and PipedOutputStream should only be used when you have multiple threads, as noted by the Javadoc.

Also, note that input streams and output streams do not wrap any thread interruptions with IOExceptions... So, you should consider incorporating an interruption policy to your code:

byte[] buffer = new byte[1024];
int len = in.read(buffer);
while (len != -1) {
    out.write(buffer, 0, len);
    len = in.read(buffer);
    if (Thread.interrupted()) {
        throw new InterruptedException();
    }
}

This would be an useful addition if you expect to use this API for copying large volumes of data, or data from streams that get stuck for an intolerably long time.

cannot import name patterns

Seems you are using outdated version of django.. Simply update django and try again.. Following command will update your django version..

pip install --upgrade django

Find index of last occurrence of a sub-string using T-SQL

This code works even if the substring contains more than 1 character.

DECLARE @FilePath VARCHAR(100) = 'My_sub_Super_sub_Long_sub_String_sub_With_sub_Long_sub_Words'
DECLARE @FindSubstring VARCHAR(5) = '_sub_'

-- Shows text before last substing
SELECT LEFT(@FilePath, LEN(@FilePath) - CHARINDEX(REVERSE(@FindSubstring), REVERSE(@FilePath)) - LEN(@FindSubstring) + 1) AS Before
-- Shows text after last substing
SELECT RIGHT(@FilePath, CHARINDEX(REVERSE(@FindSubstring), REVERSE(@FilePath)) -1) AS After
-- Shows the position of the last substing
SELECT LEN(@FilePath) - CHARINDEX(REVERSE(@FindSubstring), REVERSE(@FilePath)) AS LastOccuredAt

How to add header data in XMLHttpRequest when using formdata?

Use: xmlhttp.setRequestHeader(key, value);

Vertically aligning a checkbox

<div>
    <input type="checkbox">
    <img src="/image.png" />
</div>
input[type="checkbox"]
{
    margin-top: -50%;
    vertical-align: middle;
}

Change UITableView height dynamically

There isn't a system feature to change the height of the table based upon the contents of the tableview. Having said that, it is possible to programmatically change the height of the tableview based upon the contents, specifically based upon the contentSize of the tableview (which is easier than manually calculating the height yourself). A few of the particulars vary depending upon whether you're using the new autolayout that's part of iOS 6, or not.

But assuming you're configuring your table view's underlying model in viewDidLoad, if you want to then adjust the height of the tableview, you can do this in viewDidAppear:

- (void)viewDidAppear:(BOOL)animated
{
    [super viewDidAppear:animated];

    [self adjustHeightOfTableview];
}

Likewise, if you ever perform a reloadData (or otherwise add or remove rows) for a tableview, you'd want to make sure that you also manually call adjustHeightOfTableView there, too, e.g.:

- (IBAction)onPressButton:(id)sender
{
    [self buildModel];
    [self.tableView reloadData];

    [self adjustHeightOfTableview];
}

So the question is what should our adjustHeightOfTableview do. Unfortunately, this is a function of whether you use the iOS 6 autolayout or not. You can determine if you have autolayout turned on by opening your storyboard or NIB and go to the "File Inspector" (e.g. press option+command+1 or click on that first tab on the panel on the right):

enter image description here

Let's assume for a second that autolayout was off. In that case, it's quite simple and adjustHeightOfTableview would just adjust the frame of the tableview:

- (void)adjustHeightOfTableview
{
    CGFloat height = self.tableView.contentSize.height;
    CGFloat maxHeight = self.tableView.superview.frame.size.height - self.tableView.frame.origin.y;

    // if the height of the content is greater than the maxHeight of
    // total space on the screen, limit the height to the size of the
    // superview.

    if (height > maxHeight)
        height = maxHeight;

    // now set the frame accordingly

    [UIView animateWithDuration:0.25 animations:^{
        CGRect frame = self.tableView.frame;
        frame.size.height = height;
        self.tableView.frame = frame;

        // if you have other controls that should be resized/moved to accommodate
        // the resized tableview, do that here, too
    }];
}

If your autolayout was on, though, adjustHeightOfTableview would adjust a height constraint for your tableview:

- (void)adjustHeightOfTableview
{
    CGFloat height = self.tableView.contentSize.height;
    CGFloat maxHeight = self.tableView.superview.frame.size.height - self.tableView.frame.origin.y;

    // if the height of the content is greater than the maxHeight of
    // total space on the screen, limit the height to the size of the
    // superview.

    if (height > maxHeight)
        height = maxHeight;

    // now set the height constraint accordingly

    [UIView animateWithDuration:0.25 animations:^{
        self.tableViewHeightConstraint.constant = height;
        [self.view setNeedsUpdateConstraints];
    }];
}

For this latter constraint-based solution to work with autolayout, we must take care of a few things first:

  1. Make sure your tableview has a height constraint by clicking on the center button in the group of buttons here and then choose to add the height constraint:

    add height constraint

  2. Then add an IBOutlet for that constraint:

    add IBOutlet

  3. Make sure you adjust other constraints so they don't conflict if you adjust the size tableview programmatically. In my example, the tableview had a trailing space constraint that locked it to the bottom of the screen, so I had to adjust that constraint so that rather than being locked at a particular size, it could be greater or equal to a value, and with a lower priority, so that the height and top of the tableview would rule the day:

    adjust other constraints

    What you do here with other constraints will depend entirely upon what other controls you have on your screen below the tableview. As always, dealing with constraints is a little awkward, but it definitely works, though the specifics in your situation depend entirely upon what else you have on the scene. But hopefully you get the idea. Bottom line, with autolayout, make sure to adjust your other constraints (if any) to be flexible to account for the changing tableview height.

As you can see, it's much easier to programmatically adjust the height of a tableview if you're not using autolayout, but in case you are, I present both alternatives.

Why not inherit from List<T>?

My dirty secret: I don't care what people say, and I do it. .NET Framework is spread with "XxxxCollection" (UIElementCollection for top of my head example).

So what stops me saying:

team.Players.ByName("Nicolas")

When I find it better than

team.ByName("Nicolas")

Moreover, my PlayerCollection might be used by other class, like "Club" without any code duplication.

club.Players.ByName("Nicolas")

Best practices of yesterday, might not be the one of tomorrow. There is no reason behind most best practices, most are only wide agreement among the community. Instead of asking the community if it will blame you when you do that ask yourself, what is more readable and maintainable?

team.Players.ByName("Nicolas") 

or

team.ByName("Nicolas")

Really. Do you have any doubt? Now maybe you need to play with other technical constraints that prevent you to use List<T> in your real use case. But don't add a constraint that should not exist. If Microsoft did not document the why, then it is surely a "best practice" coming from nowhere.

If Browser is Internet Explorer: run an alternative script instead

This article is quite explanatory: http://msdn.microsoft.com/en-us/library/ms537509%28v=vs.85%29.aspx.

If your JS is unobtrusive, you can just use:

<![if !IE]>
   <script src...
<![endif]>

Do on-demand Mac OS X cloud services exist, comparable to Amazon's EC2 on-demand instances?

Here are some methods that may help others, though they aren't really services as much as they may be described as "methods that may, after some torture of effort or logic, lead to a claim of on-demand access to Mac OS X" (no doubt I should patent that phrase).

Fundamentally, I am inclined to believe that on-demand (per-hour) hosting does not exist, and @Erik has given information for the shortest feasible services, i.e. monthly hosting.


It seems that one may use EC2 itself, but install OS X on the instance through a lot of elbow grease.

  • This article on Lifehacker.com gives instructions for setting up OSX under Virtual Box and depends on hardware virtualization. It seems that the Cluster Compute instances (and Cluster GPU, but ignore these) are the only ones supporting hardware virtualization.
  • This article gives instructions for transferring a VirtualBox image to EC2.

Where this gets tricky is I'm not sure if this will work for a cluster compute instance. In fact, I think this is likely to be a royal pain. A similar approach may work for Rackspace or other cloud services.

I found only this site claiming on-demand Mac hosting, with a Mac Mini. It doesn't look particularly accurate: it offers free on-demand access to a Mini if one pays for a month of bandwidth. That's like free bandwidth if one rents a Mini for a month. That's not really how "on-demand" works.


Update 1: In the end, it seems that nobody offers a comparable service. An outfit called Media Temple claims they will offer the first virtual servers using Parallels, OS X Leopard, and some other stuff (in other words, I wonder if there is some caveat that makes them unique, but, without that caveat, someone else may have a usable offering).

After this search, I think that a counterpart to EC2 does not exist for the OS X operating system. It is extraordinarily unlikely that one would exist, offer a scalable solution, and yet be very difficult to find. One could set it up internally, but there's no reseller/vendor offering on-demand, hourly virtual servers. This may be disappointing, but not surprising - apparently iCloud is running on Amazon and Microsoft systems.

mvn command not found in OSX Mavrerick

I followed brain storm's instructions and still wasn't getting different results - any new terminal windows would not recognize the mvn command. I don't know why, but breaking out the declarations in smaller chunks .bash_profile worked. As far as I can tell, I'm essentially doing the same thing he did. Here's what looks different in my .bash_profile:

JAVA_HOME=/Library/Java/JavaVirtualMachines/jdk1.8.0_221.jdk/Contents/Home
export PATH JAVA_HOME
J2=$JAVA_HOME/bin
export PATH J2
M2_HOME=/usr/local/apache-maven/apache-maven-2.2.1
export PATH M2_HOME
M2=$M2_HOME/bin
export PATH M2

How do I delete all messages from a single queue using the CLI?

I have successfully used ampq-purge from amqp-utils to do this:

git clone https://github.com/dougbarth/amqp-utils.git
cd amqp-utils
# extracted from Rakefile
echo "source 'https://rubygems.org'
gem 'amqp', '~> 0.7.1'
gem 'trollop', '~> 1.16.2'
gem 'facets', '~> 2.9'
gem 'clio', '~> 0.3.0'
gem 'json', '~> 1.5'
gem 'heredoc_unindent', '~> 1.1.2'
gem 'msgpack', '~> 0.4.5'" > Gemfile
bundle install --path=$PWD/gems
export RUBYLIB=.
export GEM_HOME=$PWD/gems/ruby/1.9.1

ruby bin/amqp-purge -v -V /vhost -u user -p queue
# paste password at prompt

Error: "an object reference is required for the non-static field, method or property..."

Change your signatures to private static bool siprimo(long a) and private static long volteado(long a) and see where that gets you.

Why do I get access denied to data folder when using adb?

Starting from API level 8 (Android 2.2), for the debuggable application (the one built by Android Studio all the times unless the release build was requested), you can use the shell run-as command to run a command or executable as a specific user/application or just switch to the UID of your application so you can access its data directory.

List directory content of yourapp:

run-as com.yourapp ls -l /data/data/com.yourapp

Switch to UID of com.yourapp and run all further commands using that uid (until you call exit):

run-as com.yourapp
cd /data/data/com.yourapp
ls -l
exit

 
Note 1: there is a known issue with some HTC Desire phones. Because of a non-standard owner/permissions of the /data/data directory, run-as command fails to run on those phones.

Note 2: As pointed in the comments by @Avio: run-as has issues also with Samsung Galaxy S phones running Cyanogenmod at any version (from 7 to 10.1) because on this platform /data/data is a symlink to /datadata. One way to solve the issue is to replace the symlink with the actual directory (unfortunately this usually requires root access).

AngularJS event on window innerWidth size change

We could do it with jQuery:

$(window).resize(function(){
    alert(window.innerWidth);

    $scope.$apply(function(){
       //do something to update current scope based on the new innerWidth and let angular update the view.
    });
});

Be aware that when you bind an event handler inside scopes that could be recreated (like ng-repeat scopes, directive scopes,..), you should unbind your event handler when the scope is destroyed. If you don't do this, everytime when the scope is recreated (the controller is rerun), there will be 1 more handler added causing unexpected behavior and leaking.

In this case, you may need to identify your attached handler:

  $(window).on("resize.doResize", function (){
      alert(window.innerWidth);

      $scope.$apply(function(){
          //do something to update current scope based on the new innerWidth and let angular update the view.
      });
  });

  $scope.$on("$destroy",function (){
      $(window).off("resize.doResize"); //remove the handler added earlier
  });

In this example, I'm using event namespace from jQuery. You could do it differently according to your requirements.

Improvement: If your event handler takes a bit long time to process, to avoid the problem that the user may keep resizing the window, causing the event handlers to be run many times, we could consider throttling the function. If you use underscore, you can try:

$(window).on("resize.doResize", _.throttle(function (){
    alert(window.innerWidth);

    $scope.$apply(function(){
        //do something to update current scope based on the new innerWidth and let angular update the view.
    });
},100));

or debouncing the function:

$(window).on("resize.doResize", _.debounce(function (){
     alert(window.innerWidth);

     $scope.$apply(function(){
         //do something to update current scope based on the new innerWidth and let angular update the view.
     });
},100));

Difference Between throttling and debouncing a function

MySQL SELECT AS combine two columns into one

You do not need to select the columns separately in order to use them in your CONCAT. Simply remove them, and your query will become:

SELECT FirstName AS First_Name
     , LastName AS Last_Name
     , CONCAT(ContactPhoneAreaCode1, ContactPhoneNumber1) AS Contact_Phone 
  FROM TABLE1

R: `which` statement with multiple conditions

The && function is not vectorized. You need the & function:

EUR <- PCs[which(PCs$V13 < 9 & PCs$V13 > 3), ]

Remove last character of a StringBuilder?

I am doing something like below:

    StringBuilder stringBuilder = new StringBuilder();
    for (int i = 0; i < value.length; i++) {
        stringBuilder.append(values[i]);
        if (value.length-1) {
            stringBuilder.append(", ");
        }
    }

MongoDB: Combine data from multiple collections into one..how?

Mongorestore has this feature of appending on top of whatever is already in the database, so this behavior could be used for combining two collections:

  1. mongodump collection1
  2. collection2.rename(collection1)
  3. mongorestore

Didn't try it yet, but it might perform faster than the map/reduce approach.

Pandas How to filter a Series

If you like a chained operation, you can also use compress function:

test = pd.Series({
383:    3.000000,
663:    1.000000,
726:    1.000000,
737:    9.000000,
833:    8.166667
})

test.compress(lambda x: x != 1)

# 383    3.000000
# 737    9.000000
# 833    8.166667
# dtype: float64

Ordering by specific field value first

do this:

SELECT * FROM table ORDER BY column `name`+0 ASC

Appending the +0 will mean that:

0, 10, 11, 2, 3, 4

becomes :

0, 2, 3, 4, 10, 11

C# constructors overloading

public Point2D(Point2D point) : this(point.X, point.Y) { }

Stopping an Android app from console

you can use the following from the device console: pm disable com.my.app.package which will kill it. Then use pm enable com.my.app.package so that you can launch it again.

Checking if type == list in python

You should try using isinstance()

if isinstance(object, list):
       ## DO what you want

In your case

if isinstance(tmpDict[key], list):
      ## DO SOMETHING

To elaborate:

x = [1,2,3]
if type(x) == list():
    print "This wont work"
if type(x) == list:                  ## one of the way to see if it's list
    print "this will work"           
if type(x) == type(list()):
    print "lets see if this works"
if isinstance(x, list):              ## most preferred way to check if it's list
    print "This should work just fine"

The difference between isinstance() and type() though both seems to do the same job is that isinstance() checks for subclasses in addition, while type() doesn’t.

IIS Config Error - This configuration section cannot be used at this path

I came across this thread and solve the issue by below steps, My problem may be different. Hope this can help some one .

In Turn windows feature on and off navigate to server roles and select the least below mentioned items .

enter image description here

Cheers !

How to disable Django's CSRF validation?

If you want disable it in Global, you can write a custom middleware, like this

from django.utils.deprecation import MiddlewareMixin

class DisableCsrfCheck(MiddlewareMixin):

    def process_request(self, req):
        attr = '_dont_enforce_csrf_checks'
        if not getattr(req, attr, False):
            setattr(req, attr, True)

then add this class youappname.middlewarefilename.DisableCsrfCheck to MIDDLEWARE_CLASSES lists, before django.middleware.csrf.CsrfViewMiddleware

How to set the thumbnail image on HTML5 video?

<?php
$thumbs_dir = 'E:/xampp/htdocs/uploads/thumbs/';
$videos = array();
if (isset($_POST["name"])) {
 if (!preg_match('/data:([^;]*);base64,(.*)/', $_POST['data'], $matches)) {
  die("error");
 }
 $data = $matches[2];
 $data = str_replace(' ', '+', $data);
 $data = base64_decode($data);
 $file = 'text.jpg';
 $dataname = file_put_contents($thumbs_dir . $file, $data);
}
?>
//jscode
<script type="text/javascript">
 var videos = <?= json_encode($videos); ?>;
 var video = document.getElementById('video');
 video.addEventListener('canplay', function () {
     this.currentTime = this.duration / 2;
 }, false);
 var seek = true;
 video.addEventListener('seeked', function () {
    if (seek) {
         getThumb();
    }
 }, false);

 function getThumb() {
     seek = false;
     var filename = video.src;
     var w = video.videoWidth;//video.videoWidth * scaleFactor;
     var h = video.videoHeight;//video.videoHeight * scaleFactor;
     var canvas = document.createElement('canvas');
     canvas.width = w;
     canvas.height = h;
     var ctx = canvas.getContext('2d');
     ctx.drawImage(video, 0, 0, w, h);
     var data = canvas.toDataURL("image/jpg");
     var xmlhttp = new XMLHttpRequest;
     xmlhttp.onreadystatechange = function () {
         if (xmlhttp.readyState == 4 && xmlhttp.status == 200) {
         }
     }
     xmlhttp.open("POST", location.href, true);
     xmlhttp.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
     xmlhttp.send('name=' + encodeURIComponent(filename) + '&data=' + data);
 }
  function failed(e) {
     // video playback failed - show a message saying why
     switch (e.target.error.code) {
         case e.target.error.MEDIA_ERR_ABORTED:
             console.log('You aborted the video playback.');
             break;
         case e.target.error.MEDIA_ERR_NETWORK:
             console.log('A network error caused the video download to fail part-way.');
             break;
         case e.target.error.MEDIA_ERR_DECODE:
             console.log('The video playback was aborted due to a corruption problem or because the video used features your browser did not support.');
              break;
          case e.target.error.MEDIA_ERR_SRC_NOT_SUPPORTED:
              console.log('The video could not be loaded, either because the server or network failed or because the format is not supported.');
              break;
          default:
              console.log('An unknown error occurred.');
              break;
      }


  }
</script>
//Html
<div>
    <video   id="video" src="1499752288.mp4" autoplay="true"  onerror="failed(event)" controls="controls" preload="none"></video>
</div>

How to stop PHP code execution?

or try

trigger_error('Die', E_ERROR);

OS X Terminal Colors

MartinVonMartinsgrün and 4Levels methods confirmed work great on Mac OS X Mountain Lion.

The file I needed to update was ~/.profile.

However, I couldn't leave this question without recommending my favorite application, iTerm 2.

iTerm 2 lets you load global color schemes from a file. Really easy to experiment and try a bunch of color schemes.

Here's a screenshot of the iTerm 2 window and the color preferences. iTerm2 Color Preferences Screenshot Mac

Once I added the following to my ~/.profile file iTerm 2 was able to override the colors.

export CLICOLOR=1
export LSCOLORS=GxFxCxDxBxegedabagaced
export PS1='\[\033[01;32m\]\u@\h\[\033[00m\]:\[\033[01;34m\]\w\[\033[00m\]\$ '

Here is a great repository with some nice presets:

iTerm2 Color Schemes on Github by mbadolato

Bonus: Choose "Show/hide iTerm2 with a system-wide hotkey" and bind the key with BetterTouchTool for an instant hide/show the terminal with a mouse gesture.

Get DOS path instead of Windows path

similar to this answer but uses a sub-routine

@echo off
CLS

:: my code goes here
set "my_variable=C:\Program Files (x86)\Microsoft Office"

echo %my_variable%

call :_sub_Short_Path "%my_variable%"
set "my_variable=%_s_Short_Path%"

echo %my_variable%

:: rest of my code goes here
goto EOF

:_sub_Short_Path
set _s_Short_Path=%~s1
EXIT /b

:EOF

MySQL Great Circle Distance (Haversine formula)

If you add helper fields to the coordinates table, you can improve response time of the query.

Like this:

CREATE TABLE `Coordinates` (
`id` INT(10) UNSIGNED NOT NULL COMMENT 'id for the object',
`type` TINYINT(4) UNSIGNED NOT NULL DEFAULT '0' COMMENT 'type',
`sin_lat` FLOAT NOT NULL COMMENT 'sin(lat) in radians',
`cos_cos` FLOAT NOT NULL COMMENT 'cos(lat)*cos(lon) in radians',
`cos_sin` FLOAT NOT NULL COMMENT 'cos(lat)*sin(lon) in radians',
`lat` FLOAT NOT NULL COMMENT 'latitude in degrees',
`lon` FLOAT NOT NULL COMMENT 'longitude in degrees',
INDEX `lat_lon_idx` (`lat`, `lon`)
)    

If you're using TokuDB, you'll get even better performance if you add clustering indexes on either of the predicates, for example, like this:

alter table Coordinates add clustering index c_lat(lat);
alter table Coordinates add clustering index c_lon(lon);

You'll need the basic lat and lon in degrees as well as sin(lat) in radians, cos(lat)*cos(lon) in radians and cos(lat)*sin(lon) in radians for each point. Then you create a mysql function, smth like this:

CREATE FUNCTION `geodistance`(`sin_lat1` FLOAT,
                              `cos_cos1` FLOAT, `cos_sin1` FLOAT,
                              `sin_lat2` FLOAT,
                              `cos_cos2` FLOAT, `cos_sin2` FLOAT)
    RETURNS float
    LANGUAGE SQL
    DETERMINISTIC
    CONTAINS SQL
    SQL SECURITY INVOKER
   BEGIN
   RETURN acos(sin_lat1*sin_lat2 + cos_cos1*cos_cos2 + cos_sin1*cos_sin2);
   END

This gives you the distance.

Don't forget to add an index on lat/lon so the bounding boxing can help the search instead of slowing it down (the index is already added in the CREATE TABLE query above).

INDEX `lat_lon_idx` (`lat`, `lon`)

Given an old table with only lat/lon coordinates, you can set up a script to update it like this: (php using meekrodb)

$users = DB::query('SELECT id,lat,lon FROM Old_Coordinates');

foreach ($users as $user)
{
  $lat_rad = deg2rad($user['lat']);
  $lon_rad = deg2rad($user['lon']);

  DB::replace('Coordinates', array(
    'object_id' => $user['id'],
    'object_type' => 0,
    'sin_lat' => sin($lat_rad),
    'cos_cos' => cos($lat_rad)*cos($lon_rad),
    'cos_sin' => cos($lat_rad)*sin($lon_rad),
    'lat' => $user['lat'],
    'lon' => $user['lon']
  ));
}

Then you optimize the actual query to only do the distance calculation when really needed, for example by bounding the circle (well, oval) from inside and outside. For that, you'll need to precalculate several metrics for the query itself:

// assuming the search center coordinates are $lat and $lon in degrees
// and radius in km is given in $distance
$lat_rad = deg2rad($lat);
$lon_rad = deg2rad($lon);
$R = 6371; // earth's radius, km
$distance_rad = $distance/$R;
$distance_rad_plus = $distance_rad * 1.06; // ovality error for outer bounding box
$dist_deg_lat = rad2deg($distance_rad_plus); //outer bounding box
$dist_deg_lon = rad2deg($distance_rad_plus/cos(deg2rad($lat)));
$dist_deg_lat_small = rad2deg($distance_rad/sqrt(2)); //inner bounding box
$dist_deg_lon_small = rad2deg($distance_rad/cos(deg2rad($lat))/sqrt(2));

Given those preparations, the query goes something like this (php):

$neighbors = DB::query("SELECT id, type, lat, lon,
       geodistance(sin_lat,cos_cos,cos_sin,%d,%d,%d) as distance
       FROM Coordinates WHERE
       lat BETWEEN %d AND %d AND lon BETWEEN %d AND %d
       HAVING (lat BETWEEN %d AND %d AND lon BETWEEN %d AND %d) OR distance <= %d",
  // center radian values: sin_lat, cos_cos, cos_sin
       sin($lat_rad),cos($lat_rad)*cos($lon_rad),cos($lat_rad)*sin($lon_rad),
  // min_lat, max_lat, min_lon, max_lon for the outside box
       $lat-$dist_deg_lat,$lat+$dist_deg_lat,
       $lon-$dist_deg_lon,$lon+$dist_deg_lon,
  // min_lat, max_lat, min_lon, max_lon for the inside box
       $lat-$dist_deg_lat_small,$lat+$dist_deg_lat_small,
       $lon-$dist_deg_lon_small,$lon+$dist_deg_lon_small,
  // distance in radians
       $distance_rad);

EXPLAIN on the above query might say that it's not using index unless there's enough results to trigger such. The index will be used when there's enough data in the coordinates table. You can add FORCE INDEX (lat_lon_idx) to the SELECT to make it use the index with no regards to the table size, so you can verify with EXPLAIN that it is working correctly.

With the above code samples you should have a working and scalable implementation of object search by distance with minimal error.

updating Google play services in Emulator

I know it's late answer but I had same problem for last two days, and none of the above solutions worked for me. My app supports min sdk 16, Jelly Bean 4.1.x, so I wanted to test my app on emulator with 16 android api version and I needed Google Play Services.

In short, solution that worked for me is:

  • make new emulator Nexus 5X (with Play Store support) - Jelly Bean 4.1.x, 16 API level (WITHOUT Google APIs)
  • manually download apks of Google Play Store and Google Play Services (it is necessary that both apks have similar version, they need to start with same number, for example 17.x)
  • drag and drop those apks into new emulator
  • congratulations you have updated Google Play Services on your 4.1.x emulator

Here are the steps and errors I have encountered during the problem.

So I have made new emulator in my AVD. I picked Nexus 5X (with Play Store support). After that I picked Jelly Bean 16 api level (with Google APIs). When I opened my app dialog pop up with message You need to update your Google play services. When I clicked on Update button, nothing happened. I did update everything necessary in SDK manager, but nothing worked. I didn't have installed Google Play Store on my emulator, even tho I picked Nexus 5X which comes with preinstalled Play Store. So I couldn't find Google Play Store tab in Extended Controls (tree dots next to my emulator).

Because nothings worked, I decided to try to install Google Play Services manually, by downloading APK and dragging it into emulator. When I tried this, I encountered problem The APK failed to install. Error: INSTALL_PARSE_FAILED_INCONSISTENT_CERTIFICATES. I figured that this was the problem because I picked Jelly Bean 16 api level (with Google APIs). So I made new emulator

Nexus 5X (with Play Store support) - Jelly Bean 16 api level (WITHOUT Google APIs)

This allowed me to install my Google Play Service manually. But when I run my app, it still didn't want to open it. Problem was that my emulator was missing Google Play Store. So I installed it manually like Google Play Service. But when it was successfully installed, dialog started popping out every second with message Unfortunately Google Play Services has stopped. Problem was that version of my Google Play Store was 17.x and Google Play Service was 19.x. So at the end I installed Google Play Service with version 17.x, and everything worked.

Bold words in a string of strings.xml in Android

strings.xml

<string name="sentence">This price is <b>%1$s</b> USD</string>

page.java

String successMessage = getText(R.string.message,"5.21");

This price 5.21 USD

What is copy-on-write?

I was going to write up my own explanation but this Wikipedia article pretty much sums it up.

Here is the basic concept:

Copy-on-write (sometimes referred to as "COW") is an optimization strategy used in computer programming. The fundamental idea is that if multiple callers ask for resources which are initially indistinguishable, you can give them pointers to the same resource. This function can be maintained until a caller tries to modify its "copy" of the resource, at which point a true private copy is created to prevent the changes becoming visible to everyone else. All of this happens transparently to the callers. The primary advantage is that if a caller never makes any modifications, no private copy need ever be created.

Also here is an application of a common use of COW:

The COW concept is also used in maintenance of instant snapshot on database servers like Microsoft SQL Server 2005. Instant snapshots preserve a static view of a database by storing a pre-modification copy of data when underlaying data are updated. Instant snapshots are used for testing uses or moment-dependent reports and should not be used to replace backups.

How can I show line numbers in Eclipse?

this will be the appropriate solution for asked question:

String lineNumbers = AbstractDecoratedTextEditorPreferenceConstants.EDITOR_LINE_NUMBER_RULER; EditorsUI.getPreferenceStore().setValue(lineNumbers, true);

Angular - res.json() is not a function

HttpClient.get() applies res.json() automatically and returns Observable<HttpResponse<string>>. You no longer need to call this function yourself.

See Difference between HTTP and HTTPClient in angular 4?

Custom CSS Scrollbar for Firefox

Since Firefox 64, is possible to use new specs for a simple Scrollbar styling (not as complete as in Chrome with vendor prefixes).

In this example is possible to see a solution that combine different rules to address both Firefox and Chrome with a similar (not equal) final result (example use your original Chrome rules):

The key rules are:

For Firefox

.scroller {
  overflow-y: scroll;
  scrollbar-color: #0A4C95 #C2D2E4;
}

For Chrome

.scroller::-webkit-scrollbar {
    width: 15px;
    height: 15px;
}

.scroller::-webkit-scrollbar-track-piece  {
    background-color: #C2D2E4;
}

.scroller::-webkit-scrollbar-thumb:vertical {
    height: 30px;
    background-color: #0A4C95;
}

Please note that respect to your solution, is possible to use also simpler Chrome rules as the following:

.scroller::-webkit-scrollbar-track  {
    background-color: #C2D2E4;
}

.scroller::-webkit-scrollbar-thumb {
    height: 30px;
    background-color: #0A4C95;
}

Finally, in order to hide arrows in scrollbars also in Firefox, currently is necessary to set it as "thin" with the following rule scrollbar-width: thin;

Float sum with javascript

(parseFloat('2.3') + parseFloat('2.4')).toFixed(1);

its going to give you solution i suppose

JavaScript for...in vs for

If you really want to speed up your code, what about that?

for( var i=0,j=null; j=array[i++]; foo(j) );

it's kinda of having the while logic within the for statement and it's less redundant. Also firefox has Array.forEach and Array.filter

CSS no text wrap

Just use:

overflow: hidden;
white-space: nowrap;

In your item's divs

How to convert a std::string to const char* or char*?

If you just want to pass a std::string to a function that needs const char* you can use

std::string str;
const char * c = str.c_str();

If you want to get a writable copy, like char *, you can do that with this:

std::string str;
char * writable = new char[str.size() + 1];
std::copy(str.begin(), str.end(), writable);
writable[str.size()] = '\0'; // don't forget the terminating 0

// don't forget to free the string after finished using it
delete[] writable;

Edit: Notice that the above is not exception safe. If anything between the new call and the delete call throws, you will leak memory, as nothing will call delete for you automatically. There are two immediate ways to solve this.

boost::scoped_array

boost::scoped_array will delete the memory for you upon going out of scope:

std::string str;
boost::scoped_array<char> writable(new char[str.size() + 1]);
std::copy(str.begin(), str.end(), writable.get());
writable[str.size()] = '\0'; // don't forget the terminating 0

// get the char* using writable.get()

// memory is automatically freed if the smart pointer goes 
// out of scope

std::vector

This is the standard way (does not require any external library). You use std::vector, which completely manages the memory for you.

std::string str;
std::vector<char> writable(str.begin(), str.end());
writable.push_back('\0');

// get the char* using &writable[0] or &*writable.begin()

How to remove a TFS Workspace Mapping?

Follow these steps to remove mapping from TFS:

  1. Open team explorer
  2. Click Source Control
  3. Right click on you project
  4. Click on Remove Mapping

PHP Unset Session Variable

// set
$_SESSION['test'] = 1;

// destroy
unset($_SESSION['test']);

What is the difference between Dim, Global, Public, and Private as Modular Field Access Modifiers?

Dim and Private work the same, though the common convention is to use Private at the module level, and Dim at the Sub/Function level. Public and Global are nearly identical in their function, however Global can only be used in standard modules, whereas Public can be used in all contexts (modules, classes, controls, forms etc.) Global comes from older versions of VB and was likely kept for backwards compatibility, but has been wholly superseded by Public.

Get the current first responder without using a private API

The solution from romeo https://stackoverflow.com/a/2799675/661022 is cool, but I noticed that the code needs one more loop. I was working with tableViewController. I edited the script and then I checked. Everything worked perfect.

I recommed to try this:

- (void)findFirstResponder
{
    NSArray *subviews = [self.tableView subviews];
    for (id subv in subviews )
    {
        for (id cell in [subv subviews] ) {
            if ([cell isKindOfClass:[UITableViewCell class]])
            {
                UITableViewCell *aCell = cell;
                NSArray *cellContentViews = [[aCell contentView] subviews];
                for (id textField in cellContentViews)
                {
                    if ([textField isKindOfClass:[UITextField class]])
                    {
                        UITextField *theTextField = textField;
                        if ([theTextField isFirstResponder]) {
                            NSLog(@"current textField: %@", theTextField);
                            NSLog(@"current textFields's superview: %@", [theTextField superview]);
                        }
                    }
                }
            }
        }
    }
}

Changing an AIX password via script?

Just this

passwd <<EOF
oldpassword
newpassword
newpassword
EOF

Actual output from ubuntu machine (sorry no AIX available to me):

user@host:~$ passwd <<EOF
oldpassword
newpassword
newpassword
EOF

Changing password for user.
(current) UNIX password: Enter new UNIX password: Retype new UNIX password: 
passwd: password updated successfully
user@host:~$

How do you force a makefile to rebuild a target

If you don't need to preserve any of the outputs you already successfully compiled

nmake /A 

rebuilds all

PostgreSQL Autoincrement

Sorry, to rehash an old question, but this was the first Stack Overflow question/answer that popped up on Google.

This post (which came up first on Google) talks about using the more updated syntax for PostgreSQL 10: https://blog.2ndquadrant.com/postgresql-10-identity-columns/

which happens to be:

CREATE TABLE test_new (
    id int GENERATED BY DEFAULT AS IDENTITY PRIMARY KEY,
);

Hope that helps :)

Java unsupported major minor version 52.0

You have to compile with Java 1.7. But if you have *.jsp files, you should also completely remove Java 1.8 from the system. If you use Mac, here is how you can do it.

How can I easily convert DataReader to List<T>?

I would suggest writing an extension method for this:

public static IEnumerable<T> Select<T>(this IDataReader reader,
                                       Func<IDataReader, T> projection)
{
    while (reader.Read())
    {
        yield return projection(reader);
    }
}

You can then use LINQ's ToList() method to convert that into a List<T> if you want, like this:

using (IDataReader reader = ...)
{
    List<Customer> customers = reader.Select(r => new Customer {
        CustomerId = r["id"] is DBNull ? null : r["id"].ToString(),
        CustomerName = r["name"] is DBNull ? null : r["name"].ToString() 
    }).ToList();
}

I would actually suggest putting a FromDataReader method in Customer (or somewhere else):

public static Customer FromDataReader(IDataReader reader) { ... }

That would leave:

using (IDataReader reader = ...)
{
    List<Customer> customers = reader.Select<Customer>(Customer.FromDataReader)
                                     .ToList();
}

(I don't think type inference would work in this case, but I could be wrong...)

How to make a Java Generic method static?

public static <E> E[] appendToArray(E[] array, E item) { ...

Note the <E>.

Static generic methods need their own generic declaration (public static <E>) separate from the class's generic declaration (public class ArrayUtils<E>).

If the compiler complains about a type ambiguity in invoking a static generic method (again not likely in your case, but, generally speaking, just in case), here's how to explicitly invoke a static generic method using a specific type (_class_.<_generictypeparams_>_methodname_):

String[] newStrings = ArrayUtils.<String>appendToArray(strings, "another string");

This would only happen if the compiler can't determine the generic type because, e.g. the generic type isn't related to the method arguments.

How do I include a JavaScript script file in Angular and call a function from that script?

Refer the scripts inside the angular-cli.json (angular.json when using angular 6+) file.

"scripts": [
    "../path" 
 ];

then add in typings.d.ts (create this file in src if it does not already exist)

declare var variableName:any;

Import it in your file as

import * as variable from 'variableName';

What is Model in ModelAndView from Spring MVC?

new ModelAndView("welcomePage", "WelcomeMessage", message);

is shorthand for

ModelAndView mav = new ModelAndView();
mav.setViewName("welcomePage");
mav.addObject("WelcomeMessage", message);

Looking at the code above, you can see the view name is "welcomePage". Your ViewResolver (usually setup in .../WEB-INF/spring-servlet.xml) will translate this into a View. The last line of the code sets an attribute in your model (addObject("WelcomeMessage", message)). That's where the model comes into play.

How to generate .NET 4.0 classes from xsd?

xsd.exe as mentioned by Marc Gravell. The fastest way to get up and running IMO.

Or if you need more flexibility/options :

xsd2code VS add-in (Codeplex)

How to solve : SQL Error: ORA-00604: error occurred at recursive SQL level 1

I noticed following line from error.

exact fetch returns more than requested number of rows

That means Oracle was expecting one row but It was getting multiple rows. And, only dual table has that characteristic, which returns only one row.

Later I recall, I have done few changes in dual table and when I executed dual table. Then found multiple rows.

So, I truncated dual table and inserted only row which X value. And, everything working fine.

Looping through all rows in a table column, Excel-VBA

Assuming your table is called "Table1" and your column is called "Column1" then:

For i = 1 To ListObjects("Table1").ListRows.Count
    ListObjects("Table1").ListColumns("Column1").DataBodyRange(i) = "PHEV"
Next i

Change the Blank Cells to "NA"

My function takes into account factor, character vector and potential attributes, if you use haven or foreign package to read external files. Also it allows matching different self-defined na.strings. To transform all columns, simply use lappy: df[] = lapply(df, blank2na, na.strings=c('','NA','na','N/A','n/a','NaN','nan'))

See more the comments:

#' Replaces blank-ish elements of a factor or character vector to NA
#' @description Replaces blank-ish elements of a factor or character vector to NA
#' @param x a vector of factor or character or any type
#' @param na.strings case sensitive strings that will be coverted to NA. The function will do a trimws(x,'both') before conversion. If NULL, do only trimws, no conversion to NA.
#' @return Returns a vector trimws (always for factor, character) and NA converted (if matching na.strings). Attributes will also be kept ('label','labels', 'value.labels').
#' @seealso \code{\link{ez.nan2na}}
#' @export
blank2na = function(x,na.strings=c('','.','NA','na','N/A','n/a','NaN','nan')) {
    if (is.factor(x)) {
        lab = attr(x, 'label', exact = T)
        labs1 <- attr(x, 'labels', exact = T)
        labs2 <- attr(x, 'value.labels', exact = T)

        # trimws will convert factor to character
        x = trimws(x,'both')
        if (! is.null(lab)) lab = trimws(lab,'both')
        if (! is.null(labs1)) labs1 = trimws(labs1,'both')
        if (! is.null(labs2)) labs2 = trimws(labs2,'both')

        if (!is.null(na.strings)) {
            # convert to NA
            x[x %in% na.strings] = NA
            # also remember to remove na.strings from value labels 
            labs1 = labs1[! labs1 %in% na.strings]
            labs2 = labs2[! labs2 %in% na.strings]
        }

        # the levels will be reset here
        x = factor(x)

        if (! is.null(lab)) attr(x, 'label') <- lab
        if (! is.null(labs1)) attr(x, 'labels') <- labs1
        if (! is.null(labs2)) attr(x, 'value.labels') <- labs2
    } else if (is.character(x)) {
        lab = attr(x, 'label', exact = T)
        labs1 <- attr(x, 'labels', exact = T)
        labs2 <- attr(x, 'value.labels', exact = T)

        # trimws will convert factor to character
        x = trimws(x,'both')
        if (! is.null(lab)) lab = trimws(lab,'both')
        if (! is.null(labs1)) labs1 = trimws(labs1,'both')
        if (! is.null(labs2)) labs2 = trimws(labs2,'both')

        if (!is.null(na.strings)) {
            # convert to NA
            x[x %in% na.strings] = NA
            # also remember to remove na.strings from value labels 
            labs1 = labs1[! labs1 %in% na.strings]
            labs2 = labs2[! labs2 %in% na.strings]
        }

        if (! is.null(lab)) attr(x, 'label') <- lab
        if (! is.null(labs1)) attr(x, 'labels') <- labs1
        if (! is.null(labs2)) attr(x, 'value.labels') <- labs2
    } else {
        x = x
    }
    return(x)
}

How to check if function exists in JavaScript?

If you're using eval to convert a string to function, and you want to check if this eval'd method exists, you'll want to use typeof and your function string inside an eval:

var functionString = "nonexsitantFunction"
eval("typeof " + functionString) // returns "undefined" or "function"

Don't reverse this and try a typeof on eval. If you do a ReferenceError will be thrown:

var functionString = "nonexsitantFunction"
typeof(eval(functionString)) // returns ReferenceError: [function] is not defined

PHP - Modify current object in foreach loop

There are 2 ways of doing this

foreach($questions as $key => $question){
    $questions[$key]['answers'] = $answers_model->get_answers_by_question_id($question['question_id']);
}

This way you save the key, so you can update it again in the main $questions variable

or

foreach($questions as &$question){

Adding the & will keep the $questions updated. But I would say the first one is recommended even though this is shorter (see comment by Paystey)

Per the PHP foreach documentation:

In order to be able to directly modify array elements within the loop precede $value with &. In that case the value will be assigned by reference.

Show popup after page load

try something like this

<script type="text/javascript">
function PopUp(hideOrshow) {
    if (hideOrshow == 'hide') document.getElementById('ac-wrapper').style.display = "none";
    else document.getElementById('ac-wrapper').removeAttribute('style');
}
window.onload = function () {
    setTimeout(function () {
        PopUp('show');
    }, 5000);
}
</script>

and your html

<div id="ac-wrapper" style='display:none'>
    <div id="popup">
        <center>
             <h2>Popup Content Here</h2>    
            <input type="submit" name="submit" value="Submit" onClick="PopUp('hide')" />
        </center>
    </div>
</div>

Demo JsFiddle

C# Test if user has write access to a folder

I couldn't get GetAccessControl() to throw an exception on Windows 7 as recommended in the accepted answer.

I ended up using a variation of sdds's answer:

        try
        {
            bool writeable = false;
            WindowsPrincipal principal = new WindowsPrincipal(WindowsIdentity.GetCurrent());
            DirectorySecurity security = Directory.GetAccessControl(pstrPath);
            AuthorizationRuleCollection authRules = security.GetAccessRules(true, true, typeof(SecurityIdentifier));

            foreach (FileSystemAccessRule accessRule in authRules)
            {

                if (principal.IsInRole(accessRule.IdentityReference as SecurityIdentifier))
                {
                    if ((FileSystemRights.WriteData & accessRule.FileSystemRights) == FileSystemRights.WriteData)
                    {
                        if (accessRule.AccessControlType == AccessControlType.Allow)
                        {
                            writeable = true;
                        }
                        else if (accessRule.AccessControlType == AccessControlType.Deny)
                        {
                            //Deny usually overrides any Allow
                            return false;
                        }

                    } 
                }
            }
            return writeable;
        }
        catch (UnauthorizedAccessException)
        {
            return false;
        }

Hope this helps.

How to move Jenkins from one PC to another

In case your JENKINS_HOME directory is too large to copy, and all you need is to set up same jobs, Jenkins Plugins and Jenkins configurations (and don't need old Job artifacts and reports), then you can use the ThinBackup Plugin:

  1. Install ThinBackup on both the source and the target Jenkins servers

  2. Configure the backup directory on both (in Manage Jenkins ? ThinBackup ? Settings)

  3. On the source Jenkins, go to ThinBackup ? Backup Now

  4. Copy from Jenkins source backup directory to the Jenkins target backup directory

  5. On the target Jenkins, go to ThinBackup ? Restore, and then restart the Jenkins service.

  6. If some plugins or jobs are missing, copy the backup content directly to the target JENKINS_HOME.

  7. If you had user authentication on the source Jenkins, and now locked out on the target Jenkins, then edit Jenkins config.xml, set <useSecurity> to false, and restart Jenkins.

Omitting all xsi and xsd namespaces when serializing an object in .NET?

This is the 2nd of two answers.

If you want to just strip all namespaces arbitrarily from a document during serialization, you can do this by implementing your own XmlWriter.

The easiest way is to derive from XmlTextWriter and override the StartElement method that emits namespaces. The StartElement method is invoked by the XmlSerializer when emitting any elements, including the root. By overriding the namespace for each element, and replacing it with the empty string, you've stripped the namespaces from the output.

public class NoNamespaceXmlWriter : XmlTextWriter
{
    //Provide as many contructors as you need
    public NoNamespaceXmlWriter(System.IO.TextWriter output)
        : base(output) { Formatting= System.Xml.Formatting.Indented;}

    public override void WriteStartDocument () { }

    public override void WriteStartElement(string prefix, string localName, string ns)
    {
        base.WriteStartElement("", localName, "");
    }
}

Suppose this is the type:

// explicitly specify a namespace for this type,
// to be used during XML serialization.
[XmlRoot(Namespace="urn:Abracadabra")]
public class MyTypeWithNamespaces
{
    // private fields backing the properties
    private int _Epoch;
    private string _Label;

    // explicitly define a distinct namespace for this element
    [XmlElement(Namespace="urn:Whoohoo")]
    public string Label
    {
        set {  _Label= value; } 
        get { return _Label; } 
    }

    // this property will be implicitly serialized to XML using the
    // member name for the element name, and inheriting the namespace from
    // the type.
    public int Epoch
    {
        set {  _Epoch= value; } 
        get { return _Epoch; } 
    }
}

Here's how you would use such a thing during serialization:

        var o2= new MyTypeWithNamespaces { ..intializers.. };
        var builder = new System.Text.StringBuilder();
        using ( XmlWriter writer = new NoNamespaceXmlWriter(new System.IO.StringWriter(builder)))
        {
            s2.Serialize(writer, o2, ns2);
        }            
        Console.WriteLine("{0}",builder.ToString());

The XmlTextWriter is sort of broken, though. According to the reference doc, when it writes it does not check for the following:

  • Invalid characters in attribute and element names.

  • Unicode characters that do not fit the specified encoding. If the Unicode characters do not fit the specified encoding, the XmlTextWriter does not escape the Unicode characters into character entities.

  • Duplicate attributes.

  • Characters in the DOCTYPE public identifier or system identifier.

These problems with XmlTextWriter have been around since v1.1 of the .NET Framework, and they will remain, for backward compatibility. If you have no concerns about those problems, then by all means use the XmlTextWriter. But most people would like a bit more reliability.

To get that, while still suppressing namespaces during serialization, instead of deriving from XmlTextWriter, define a concrete implementation of the abstract XmlWriter and its 24 methods.

An example is here:

public class XmlWriterWrapper : XmlWriter
{
    protected XmlWriter writer;

    public XmlWriterWrapper(XmlWriter baseWriter)
    {
        this.Writer = baseWriter;
    }

    public override void Close()
    {
        this.writer.Close();
    }

    protected override void Dispose(bool disposing)
    {
        ((IDisposable) this.writer).Dispose();
    }

    public override void Flush()
    {
        this.writer.Flush();
    }

    public override string LookupPrefix(string ns)
    {
        return this.writer.LookupPrefix(ns);
    }

    public override void WriteBase64(byte[] buffer, int index, int count)
    {
        this.writer.WriteBase64(buffer, index, count);
    }

    public override void WriteCData(string text)
    {
        this.writer.WriteCData(text);
    }

    public override void WriteCharEntity(char ch)
    {
        this.writer.WriteCharEntity(ch);
    }

    public override void WriteChars(char[] buffer, int index, int count)
    {
        this.writer.WriteChars(buffer, index, count);
    }

    public override void WriteComment(string text)
    {
        this.writer.WriteComment(text);
    }

    public override void WriteDocType(string name, string pubid, string sysid, string subset)
    {
        this.writer.WriteDocType(name, pubid, sysid, subset);
    }

    public override void WriteEndAttribute()
    {
        this.writer.WriteEndAttribute();
    }

    public override void WriteEndDocument()
    {
        this.writer.WriteEndDocument();
    }

    public override void WriteEndElement()
    {
        this.writer.WriteEndElement();
    }

    public override void WriteEntityRef(string name)
    {
        this.writer.WriteEntityRef(name);
    }

    public override void WriteFullEndElement()
    {
        this.writer.WriteFullEndElement();
    }

    public override void WriteProcessingInstruction(string name, string text)
    {
        this.writer.WriteProcessingInstruction(name, text);
    }

    public override void WriteRaw(string data)
    {
        this.writer.WriteRaw(data);
    }

    public override void WriteRaw(char[] buffer, int index, int count)
    {
        this.writer.WriteRaw(buffer, index, count);
    }

    public override void WriteStartAttribute(string prefix, string localName, string ns)
    {
        this.writer.WriteStartAttribute(prefix, localName, ns);
    }

    public override void WriteStartDocument()
    {
        this.writer.WriteStartDocument();
    }

    public override void WriteStartDocument(bool standalone)
    {
        this.writer.WriteStartDocument(standalone);
    }

    public override void WriteStartElement(string prefix, string localName, string ns)
    {
        this.writer.WriteStartElement(prefix, localName, ns);
    }

    public override void WriteString(string text)
    {
        this.writer.WriteString(text);
    }

    public override void WriteSurrogateCharEntity(char lowChar, char highChar)
    {
        this.writer.WriteSurrogateCharEntity(lowChar, highChar);
    }

    public override void WriteValue(bool value)
    {
        this.writer.WriteValue(value);
    }

    public override void WriteValue(DateTime value)
    {
        this.writer.WriteValue(value);
    }

    public override void WriteValue(decimal value)
    {
        this.writer.WriteValue(value);
    }

    public override void WriteValue(double value)
    {
        this.writer.WriteValue(value);
    }

    public override void WriteValue(int value)
    {
        this.writer.WriteValue(value);
    }

    public override void WriteValue(long value)
    {
        this.writer.WriteValue(value);
    }

    public override void WriteValue(object value)
    {
        this.writer.WriteValue(value);
    }

    public override void WriteValue(float value)
    {
        this.writer.WriteValue(value);
    }

    public override void WriteValue(string value)
    {
        this.writer.WriteValue(value);
    }

    public override void WriteWhitespace(string ws)
    {
        this.writer.WriteWhitespace(ws);
    }


    public override XmlWriterSettings Settings
    {
        get
        {
            return this.writer.Settings;
        }
    }

    protected XmlWriter Writer
    {
        get
        {
            return this.writer;
        }
        set
        {
            this.writer = value;
        }
    }

    public override System.Xml.WriteState WriteState
    {
        get
        {
            return this.writer.WriteState;
        }
    }

    public override string XmlLang
    {
        get
        {
            return this.writer.XmlLang;
        }
    }

    public override System.Xml.XmlSpace XmlSpace
    {
        get
        {
            return this.writer.XmlSpace;
        }
    }        
}

Then, provide a derived class that overrides the StartElement method, as before:

public class NamespaceSupressingXmlWriter : XmlWriterWrapper
{
    //Provide as many contructors as you need
    public NamespaceSupressingXmlWriter(System.IO.TextWriter output)
        : base(XmlWriter.Create(output)) { }

    public NamespaceSupressingXmlWriter(XmlWriter output)
        : base(XmlWriter.Create(output)) { }

    public override void WriteStartElement(string prefix, string localName, string ns)
    {
        base.WriteStartElement("", localName, "");
    }
}

And then use this writer like so:

        var o2= new MyTypeWithNamespaces { ..intializers.. };
        var builder = new System.Text.StringBuilder();
        var settings = new XmlWriterSettings { OmitXmlDeclaration = true, Indent= true };
        using ( XmlWriter innerWriter = XmlWriter.Create(builder, settings))
            using ( XmlWriter writer = new NamespaceSupressingXmlWriter(innerWriter))
            {
                s2.Serialize(writer, o2, ns2);
            }            
        Console.WriteLine("{0}",builder.ToString());

Credit for this to Oleg Tkachenko.

A cycle was detected in the build path of project xxx - Build Path Problem

I have this problem,too.I just disable Workspace resolution,and then all was right.enter image description here

fatal: 'origin' does not appear to be a git repository

It is possible the other branch you try to pull from is out of synch; so before adding and removing remote try to (if you are trying to pull from master)

git pull origin master

for me that simple call solved those error messages:

  • fatal: 'master' does not appear to be a git repository
  • fatal: Could not read from remote repository.

DateTime.TryParse issue with dates of yyyy-dd-MM format

DateTime dt = DateTime.ParseExact("11-22-2012 12:00 am", "MM-dd-yyyy hh:mm tt", System.Globalization.CultureInfo.InvariantCulture);

Private Variables and Methods in Python

The double underscore. It mangles the name in such a way that it can't be accessed simply through __fieldName from outside the class, which is what you want to begin with if they're to be private. (Though it's still not very hard to access the field.)

class Foo:
    def __init__(self):
        self.__privateField = 4;
        print self.__privateField # yields 4 no problem

foo = Foo()
foo.__privateField
# AttributeError: Foo instance has no attribute '__privateField'

It will be accessible through _Foo__privateField instead. But it screams "I'M PRIVATE DON'T TOUCH ME", which is better than nothing.

Google maps API V3 - multiple markers on exact same spot

This is more of a stopgap 'quick and dirty' solution similar to the one Matthew Fox suggests, this time using JavaScript.

In JavaScript you can just offset the lat and long of all of your locations by adding a small random offset to both e.g.

myLocation[i].Latitude+ = (Math.random() / 25000)

(I found that dividing by 25000 gives enough separation but doesn't move the marker significantly from the exact location e.g. a specific address)

This makes a reasonably good job of offsetting them from one another, but only after you've zoomed in closely. When zoomed out, it still won't be clear that there are multiple options for the location.

mysql_connect(): The mysql extension is deprecated and will be removed in the future: use mysqli or PDO instead

Simply put, you need to rewrite all of your database connections and queries.

You are using mysql_* functions which are now deprecated and will be removed from PHP in the future. So you need to start using MySQLi or PDO instead, just as the error notice warned you.

A basic example of using PDO (without error handling):

<?php
$db = new PDO('mysql:host=localhost;dbname=testdb;charset=utf8', 'username', 'password');
$result = $db->exec("INSERT INTO table(firstname, lastname) VAULES('John', 'Doe')");
$insertId = $db->lastInsertId();
?>

A basic example of using MySQLi (without error handling):

$db = new mysqli($DBServer, $DBUser, $DBPass, $DBName);
$result = $db->query("INSERT INTO table(firstname, lastname) VAULES('John', 'Doe')");

Here's a handy little PDO tutorial to get you started. There are plenty of others, and ones about the PDO alternative, MySQLi.

Simple proof that GUID is not unique

for(begin; begin<end; begin)
    Console.WriteLine(System.Guid.NewGuid().ToString());

You aren't incrementing begin so the condition begin < end is always true.

Developing for Android in Eclipse: R.java not regenerating

If your OS is Ubuntu, I can provide some suggestion:

  1. Install or upgrade ia32-lib:

    sudo apt-get upgrade ia32-libs
    
  2. Check if you have the right permission on the aapt folder:

    cd ANDROID/adt-bundle-linux-x86_64-20130522/sdk/build-tools/android-4.2.2
    chmod 777 aapt
    
  3. Start Eclipse:

    sudo eclipse
    
  4. Run Project -> Clean in Eclipse

Sorting hashmap based on keys

TreeMap will automatically sort in ascending order. If you want to sort in descending order, use the following code:

Copy the below code within your class and outside of the main execute method:

static class DescOrder implements Comparator<String> {
    @Override
    public int compare(String o1, String o2) {      
        return o2.compareTo(o1);
    }
    }

Then in your logic:

TreeMap<String, String> map = new TreeMap<String, String>(new DescOrder());
map.put("A", "test1");
map.put("C", "test3");
map.put("E", "test5");
map.put("B", "test2");
map.put("D", "test4");

list all files in the folder and also sub folders

You can return a List instead of an array and things gets much simpler.

    public static List<File> listf(String directoryName) {
        File directory = new File(directoryName);

        List<File> resultList = new ArrayList<File>();

        // get all the files from a directory
        File[] fList = directory.listFiles();
        resultList.addAll(Arrays.asList(fList));
        for (File file : fList) {
            if (file.isFile()) {
                System.out.println(file.getAbsolutePath());
            } else if (file.isDirectory()) {
                resultList.addAll(listf(file.getAbsolutePath()));
            }
        }
        //System.out.println(fList);
        return resultList;
    } 

ImportError: No module named sklearn.cross_validation

sklearn.cross_validation

has changed to

sklearn.model_selection

Checkout the documentation here: https://scikit-learn.org/stable/modules/cross_validation.html

Save byte array to file

You can use:

File.WriteAllBytes("Foo.txt", arrBytes); // Requires System.IO

If you have an enumerable and not an array, you can use:

File.WriteAllBytes("Foo.txt", arrBytes.ToArray()); // Requires System.Linq

How to get the date and time values in a C program?

#include<stdio.h>
using namespace std;

int main()
{
printf("%s",__DATE__);
printf("%s",__TIME__);

return 0;
}

Python: Select subset from list based on index set

Matlab and Scilab languages offer a simpler and more elegant syntax than Python for the question you're asking, so I think the best you can do is to mimic Matlab/Scilab by using the Numpy package in Python. By doing this the solution to your problem is very concise and elegant:

from numpy import *
property_a = array([545., 656., 5.4, 33.])
property_b = array([ 1.2,  1.3, 2.3, 0.3])
good_objects = [True, False, False, True]
good_indices = [0, 3]
property_asel = property_a[good_objects]
property_bsel = property_b[good_indices]

Numpy tries to mimic Matlab/Scilab but it comes at a cost: you need to declare every list with the keyword "array", something which will overload your script (this problem doesn't exist with Matlab/Scilab). Note that this solution is restricted to arrays of number, which is the case in your example.

Get element of JS object with an index

JS objects have no defined order, they are (by definition) an unsorted set of key-value pairs.

If by "first" you mean "first in lexicographical order", you can however use:

var sortedKeys = Object.keys(myobj).sort();

and then use:

var first = myobj[sortedKeys[0]];

Error to run Android Studio

On my Linux Mint 17.3 install, I found these instructions incredibly helpful.

The problem seems to boil down to the system's default Java being OpenJDK and Android Studio preferring Oracle's JDK. I actually did not perform the OpenJDK removal steps given in the tutorial, but only downloaded the Oracle JDK and set it as my system's default. Android Studio worked right away.

In case the linked page ever goes away, the steps I took were

Download Oracle JDK. Mine was version 1.7.0_79.

tar -zxvf jdk-7u79-linux-x64.tar.gz
sudo mkdir -p /opt/java
sudo mv jdk1.7.0_79 /opt/java
sudo update-alternatives --install "/usr/bin/java" "java" "/opt/java/jdk1.7.0_79/bin/java" 1
sudo update-alternatives --set java /opt/java/jdk1.7.0_25/bin/java

and

java -version

confirms the system is using Oracle's JDK, giving output like

java version "1.7.0_79"
Java(TM) SE Runtime Environment (build 1.7.0_79-b15)
Java HotSpot(TM) 64-Bit Server VM (build 24.79-b02, mixed mode)

Disable HTTP OPTIONS, TRACE, HEAD, COPY and UNLOCK methods in IIS

This worked for me but only after forcing the specific verbs to be handled by the default handler.

<system.web>
...
  <httpHandlers>
  ... 
    <add path="*" verb="OPTIONS" type="System.Web.DefaultHttpHandler" validate="true"/>
    <add path="*" verb="TRACE" type="System.Web.DefaultHttpHandler" validate="true"/>
    <add path="*" verb="HEAD" type="System.Web.DefaultHttpHandler" validate="true"/>

You still use the same configuration as you have above, but also force the verbs to be handled with the default handler and validated. Source: http://forums.asp.net/t/1311323.aspx

An easy way to test is just to deny GET and see if your site loads.

How to compare only date components from DateTime in EF?

You can also use this:

DbFunctions.DiffDays(date1, date2) == 0

php static function

Entire difference is, you don't get $this supplied inside the static function. If you try to use $this, you'll get a Fatal error: Using $this when not in object context.

Well, okay, one other difference: an E_STRICT warning is generated by your first example.

Calling a php function by onclick event

onclick event to call a function

  <strike> <input type="button" value="NEXT"  onclick="document.write('<?php //call a function here ex- 'fun();' ?>');" />    </strike>

it will surely help you

it take a little more time than normal but wait it will work

C++ error : terminate called after throwing an instance of 'std::bad_alloc'

Something throws an exception of type std::bad_alloc, indicating that you ran out of memory. This exception is propagated through until main, where it "falls off" your program and causes the error message you see.

Since nobody here knows what "RectInvoice", "rectInvoiceVector", "vect", "im" and so on are, we cannot tell you what exactly causes the out-of-memory condition. You didn't even post your real code, because w h looks like a syntax error.

How do I write outputs to the Log in Android?

The Tag is just used to easily find your output, because the Output of LogCat can be sometimes very long. You can define somewhere in your class:

private static final String TAG = "myApp";

and use it when debugging

Log.v(TAG, "did something");

enter image description here

You can apply as well a Filter to only search for the tag.

Find an object in array?

Use Dollar which is Lo-Dash or Underscore.js for Swift:

import Dollar

let found = $.find(array) { $0.name == "Foo" }

CSS media queries: max-width OR max-height

CSS Media Queries & Logical Operators: A Brief Overview ;)

The quick answer.

Separate rules with commas: @media handheld, (min-width: 650px), (orientation: landscape) { ... }

The long answer.

There's a lot here, but I've tried to make it information dense, not just fluffy writing. It's been a good chance to learn myself! Take the time to systematically read though and I hope it will be helpful.


Media Queries

Media queries essentially are used in web design to create device- or situation-specific browsing experiences; this is done using the @media declaration within a page's CSS. This can be used to display a webpage differently under a large number of circumstances: whether you are on a tablet or TV with different aspect ratios, whether your device has a color or black-and-white screen, or, perhaps most frequently, when a user changes the size of their browser or switches between browsing devices with varying screen sizes (very generally speaking, designing like this is referred to as Responsive Web Design)

Logical Operators

In designing for these situations, there appear to be four Logical Operators that can be used to require more complex combinations of requirements when targeting a variety of devices or viewport sizes.

(Note: If you don't understand the the differences between media rules, media queries, and feature queries, browse the bottom section of this answer first to get a bit better acquainted with the terminology associated with media query syntax

1. AND (and keyword)

Requires that all conditions specified must be met before the styling rules will take effect.

@media screen and (min-width: 700px) and (orientation: landscape) { ... }

The specified styling rules won't go into place unless all of the following evaluate as true:

  • The media type is 'screen' and
  • The viewport is at least 700px wide and
  • Screen orientation is currently landscape.

Note: I believe that used together, these three feature queries make up a single media query.

2. OR (Comma-separated lists)

Rather than an or keyword, comma-separated lists are used in chaining multiple media queries together to form a more complex media rule

@media handheld, (min-width: 650px), (orientation: landscape) { ... }

The specified styling rules will go into effect once any one media query evaluates as true:

  1. The media type is 'handheld' or
  2. The viewport is at least 650px wide or
  3. Screen orientation is currently landscape.

3. NOT (not keyword)

The not keyword can be used to negate a single media query (and NOT a full media rule--meaning that it only negates entries between a set of commas and not the full media rule following the @media declaration).

Similarly, note that the not keyword negates media queries, it cannot be used to negate an individual feature query within a media query.*

@media not screen and (min-resolution: 300dpi), (min-width: 800px) { ... }

The styling specified here will go into effect if

  1. The media type AND min-resolution don't both meet their requirements ('screen' and '300dpi' respectively) or
  2. The viewport is at least 800 pixels wide.

In other words, if the media type is 'screen' and the min-resolution is 300 dpi, the rule will not go into effect unless the min-width of the viewport is at least 800 pixels.

(The not keyword can be a little funky to state. Let me know if I can do better. ;)

4. ONLY (only keyword)

As I understand it, the only keyword is used to prevent older browsers from misinterpreting newer media queries as the earlier-used, narrower media type. When used correctly, older/non-compliant browsers should just ignore the styling altogether.

<link rel="stylesheet" media="only screen and (color)" href="example.css" />

An older / non-compliant browser would just ignore this line of code altogether, I believe as it would read the only keyword and consider it an incorrect media type. (See here and here for more info from smarter people)

FOR MORE INFO

For more info (including more features that can be queried), see: https://developer.mozilla.org/en-US/docs/Web/Guide/CSS/Media_queries#Logical_operators


Understanding Media Query Terminology

Note: I needed to learn the following terminology for everything here to make sense, particularly concerning the not keyword. Here it is as I understand it:

A media rule (MDN also seems to call these media statements) includes the term @media with all of its ensuing media queries

@media all and (min-width: 800px)

@media only screen and (max-resolution:800dpi), not print

@media screen and (min-width: 700px), (orientation: landscape)

@media handheld, (min-width: 650px), (min-aspect-ratio: 1/1)

A media query is a set of feature queries. They can be as simple as one feature query or they can use the and keyword to form a more complex query. Media queries can be comma-separated to form more complex media rules (see the or keyword above).

screen (Note: Only one feature query in use here.)

only screen

only screen and (max-resolution:800dpi)

only tv and (device-aspect-ratio: 16/9) and (color)

NOT handheld, (min-width: 650px). (Note the comma: there are two media queries here.)

A feature query is the most basic portion of a media rule and simply concerns a given feature and its status in a given browsing situation.

screen

(min-width: 650px)

(orientation: landscape)

(device-aspect-ratio: 16/9)


Code snippets and information derived from:

CSS media queries by Mozilla Contributors (licensed under CC-BY-SA 2.5). Some code samples were used with minor alterations to (hopefully) increase clarity of explanation.

ImportError: numpy.core.multiarray failed to import

The same error came for me. The problem is that you might have created a file called numpy.py. This file might coincide with numpy library. So, delete that numpy.py file and the problem gets solved.

What does it mean by select 1 from table?

it does what it says - it will always return the integer 1. It's used to check whether a record matching your where clause exists.

pandas: find percentile stats of a given column

You can use the pandas.DataFrame.quantile() function, as shown below.

import pandas as pd
import random

A = [ random.randint(0,100) for i in range(10) ]
B = [ random.randint(0,100) for i in range(10) ]

df = pd.DataFrame({ 'field_A': A, 'field_B': B })
df
#    field_A  field_B
# 0       90       72
# 1       63       84
# 2       11       74
# 3       61       66
# 4       78       80
# 5       67       75
# 6       89       47
# 7       12       22
# 8       43        5
# 9       30       64

df.field_A.mean()   # Same as df['field_A'].mean()
# 54.399999999999999

df.field_A.median() 
# 62.0

# You can call `quantile(i)` to get the i'th quantile,
# where `i` should be a fractional number.

df.field_A.quantile(0.1) # 10th percentile
# 11.9

df.field_A.quantile(0.5) # same as median
# 62.0

df.field_A.quantile(0.9) # 90th percentile
# 89.10000000000001

What's the regular expression that matches a square bracket?

If you want to remove the [ or the ], use the expression: "\\[|\\]".

The two backslashes escape the square bracket and the pipe is an "or".

"break;" out of "if" statement?

As already mentioned that, break-statement works only with switches and loops. Here is another way to achieve what is being asked. I am reproducing https://stackoverflow.com/a/257421/1188057 as nobody else mentioned it. It's just a trick involving the do-while loop.

do {
  // do something
  if (error) {
    break;
  }
  // do something else
  if (error) {
    break;
  }
  // etc..
} while (0);

Though I would prefer the use of goto-statement.

Composer - the requested PHP extension mbstring is missing from your system

sudo apt-get install php-mbstring

# if your are using php 7.1
sudo apt-get install php7.1-mbstring

# if your are using php 7.2
sudo apt-get install php7.2-mbstring

If strings starts with in PowerShell

$Group is an object, but you will actually need to check if $Group.samaccountname.StartsWith("string").

Change $Group.StartsWith("S_G_") to $Group.samaccountname.StartsWith("S_G_").

android image button

You can use the button :

1 - make the text empty

2 - set the background for it

+3 - you can use the selector to more useful and nice button


About the imagebutton you can set the image source and the background the same picture and it must be (*.png) when you do it you can make any design for the button

and for more beauty button use the selector //just Google it ;)

How to get body of a POST in php?

function getPost()
{
    if(!empty($_POST))
    {
        // when using application/x-www-form-urlencoded or multipart/form-data as the HTTP Content-Type in the request
        // NOTE: if this is the case and $_POST is empty, check the variables_order in php.ini! - it must contain the letter P
        return $_POST;
    }

    // when using application/json as the HTTP Content-Type in the request 
    $post = json_decode(file_get_contents('php://input'), true);
    if(json_last_error() == JSON_ERROR_NONE)
    {
        return $post;
    }

    return [];
}

print_r(getPost());

T-SQL loop over query results

DECLARE @id INT
DECLARE @name NVARCHAR(100)
DECLARE @getid CURSOR

SET @getid = CURSOR FOR
SELECT table.id,
       table.name
FROM   table

WHILE 1=1
BEGIN

    FETCH NEXT
    FROM @getid INTO @id, @name
    IF @@FETCH_STATUS < 0 BREAK

    EXEC stored_proc @varName=@id, @otherVarName='test', @varForName=@name

END

CLOSE @getid
DEALLOCATE @getid

Why "net use * /delete" does not work but waits for confirmation in my PowerShell script?

Try this:

net use * /delete /y

The /y key makes it select Yes in prompt silently

Can you use if/else conditions in CSS?

You can add container div for all your condition scope.

Add the condition value as a class to the container div. (you can set it by server side programming - php/asp...)

<!--container div-->
<div class="true-value">
   <!-- your content -->
   <p>my content</p>
   <p>my content</p>
   <p>my content</p>
</div>

Now you can use the container class as a global variable for all elements in the div using a nested selector, without adding the class to each element.

.true-value p{
   background-color:green;
}
.false-value p{
   background-color:red;
}

Parse JSON file using GSON

One thing that to be remembered while solving such problems is that in JSON file, a { indicates a JSONObject and a [ indicates JSONArray. If one could manage them properly, it would be very easy to accomplish the task of parsing the JSON file. The above code was really very helpful for me and I hope this content adds some meaning to the above code.

The Gson JsonReader documentation explains how to handle parsing of JsonObjects and JsonArrays:

  • Within array handling methods, first call beginArray() to consume the array's opening bracket. Then create a while loop that accumulates values, terminating when hasNext() is false. Finally, read the array's closing bracket by calling endArray().
  • Within object handling methods, first call beginObject() to consume the object's opening brace. Then create a while loop that assigns values to local variables based on their name. This loop should terminate when hasNext() is false. Finally, read the object's closing brace by calling endObject().

IllegalStateException: Can not perform this action after onSaveInstanceState with ViewPager

I had the exact same problem. It happened because of the destruction of previous activity. when i backed the previous activity it was destroyed. I put it base activity (WRONG)

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    SpinnerCustom2.setFragmentManager(getSupportFragmentManager());
    onCreateDrawerActivity(savedInstanceState);
}

I put it into onStart it was RIGHT

@Override
protected void onStart() {
    super.onStart();
    SpinnerCustom2.setFragmentManager(getSupportFragmentManager());

}

How to lay out Views in RelativeLayout programmatically?

Cut the long story short: With relative layout you position elements inside the layout.

  1. create a new RelativeLayout.LayoutParams

    RelativeLayout.LayoutParams lp = new RelativeLayout.LayoutParams(...)
    

    (whatever... fill parent or wrap content, absolute numbers if you must, or reference to an XML resource)

  2. Add rules: Rules refer to the parent or to other "brothers" in the hierarchy.

    lp.addRule(RelativeLayout.BELOW, someOtherView.getId())
    lp.addRule(RelativeLayout.ALIGN_PARENT_LEFT)
    
  3. Just apply the layout params: The most 'healthy' way to do that is:

    parentLayout.addView(myView, lp)
    

Watch out: Don't change layout from the layout callbacks. It is tempting to do so because this is when views get their actual sizes. However, in that case, unexpected results are expected.

Is it possible to define more than one function per file in MATLAB, and access them from outside that file?

I really like SCFrench's answer - I would like to point out that it can easily be modified to import the functions directly to the workspace using the assignin function. (Doing it like this reminds me a lot of Python's "import x from y" way of doing things)

function message = makefuns
  assignin('base','fun1',@fun1);
  assignin('base','fun2',@fun2);
  message='Done importing functions to workspace';
end

function y=fun1(x)
  y=x;
end

function z=fun2
  z=1;
end

And then used thusly:

>> makefuns
ans =
Done importing functions to workspace

>> fun1(123)
ans =
   123

>> fun2()
ans =
     1

How to throw a C++ exception

Just add throw where needed, and try block to the caller that handles the error. By convention you should only throw things that derive from std::exception, so include <stdexcept> first.

int compare(int a, int b) {
    if (a < 0 || b < 0) {
        throw std::invalid_argument("a or b negative");
    }
}

void foo() {
    try {
        compare(-1, 0);
    } catch (const std::invalid_argument& e) {
        // ...
    }
}

Also, look into Boost.Exception.

Passing a string array as a parameter to a function java

All the answers above are correct. But just note that you'll be passing the reference to the string array when you pass like this. If you make any modifications to the array in your called function, it will be reflected in the calling function also.

There is another concept called variable arguments in Java which you can look into. It basically works like this. Eg:-

 String concat (String ... strings)
   {
      StringBuilder sb = new StringBuilder ();
      for (int i = 0; i &lt; strings.length; i++)
           sb.append (strings [i]);
      return sb.toString ();
   }

Here we can call the function like concat(a,b,c,d) or any number of params you want.

More Info: http://today.java.net/pub/a/today/2004/04/19/varargs.html

height: 100% for <div> inside <div> with display: table-cell

Define your .table and .cell height:100%;

    .table {
        display: table;
        height:100%;
    }

    .cell {
        border: 1px solid black;
        display: table-cell;
        vertical-align:top;
height: 100%;

    }

    .container {
        height: 100%;
        border: 10px solid green;

    }

Demo

Class has no objects member

Just adding on to what @Mallory-Erik said: You can place objects = models.Manager() it in the modals:

class Question(models.Model):
    # ...
    def was_published_recently(self):
        return self.pub_date >= timezone.now() - datetime.timedelta(days=1)
    # ...
    def __str__(self):
        return self.question_text
    question_text = models.CharField(max_length = 200)
    pub_date = models.DateTimeField('date published')
    objects = models.Manager()

Google Maps Android API v2 - Interactive InfoWindow (like in original android google maps)

Just a speculation, I have not enough experience to try it... )-:

Since GoogleMap is a fragment, it should be possible to catch marker onClick event and show custom fragment view. A map fragment will be still visible on the background. Does anybody tried it? Any reason why it could not work?

The disadvantage is that map fragment would be freezed on backgroud, until a custom info fragment return control to it.

Clear and refresh jQuery Chosen dropdown list

In my case, I need to update selected value at each change because when I submit form, it always gets wrong values and I used multiple chosen drop downs. Rather than updating single entries, change selector to update all drop downs. This might help someone

 $(".chosen-select").chosen().change(function () {
    var item = $(this).val();
    $('.chosen-select').trigger('chosen:updated');
});

GitHub: invalid username or password

https://[email protected]/eurydyce/MDANSE.git is not an ssh url, it is an https one (which would require your GitHub account name, instead of 'git').

Try to use ssh://[email protected]:eurydyce/MDANSE.git or just [email protected]:eurydyce/MDANSE.git

git remote set-url origin [email protected]:eurydyce/MDANSE.git

The OP Pellegrini Eric adds:

That's what I did in my ~/.gitconfig file that contains currently the following entries [remote "origin"] [email protected]:eurydyce/MDANSE.git

This should not be in your global config (the one in ~/).
You could check git config -l in your repo: that url should be declared in the local config: <yourrepo>/.git/config.

So make sure you are in the repo path when doing the git remote set-url command.


As noted in Oliver's answer, an HTTPS URL would not use username/password if two-factor authentication (2FA) is activated.

In that case, the password should be a PAT (personal access token) as seen in "Using a token on the command line".

That applies only for HTTPS URLS, SSH is not affected by this limitation.

Git adding files to repo

After adding files to the stage, you need to commit them with git commit -m "comment" after git add .. Finally, to push them to a remote repository, you need to git push <remote_repo> <local_branch>.

Using Python's os.path, how do I go up one directory?

You want exactly this:

BASE_DIR = os.path.join( os.path.dirname( __file__ ), '..' )

Why is Python running my module when I import it, and how do I stop it?

There was a Python enhancement proposal PEP 299 which aimed to replace if __name__ == '__main__': idiom with def __main__:, but it was rejected. It's still a good read to know what to keep in mind when using if __name__ = '__main__':.

jQuery - Click event on <tr> elements with in a table and getting <td> element values

<script>
jQuery(document).ready(function() {
    jQuery("tr").click(function(){
       alert("Click! "+ jQuery(this).find('td').html());
    });
});
</script>

How do I create documentation with Pydoc?

Another thing that people may find useful...make sure to leave off ".py" from your module name. For example, if you are trying to generate documentation for 'original' in 'original.py':

yourcode_dir$ pydoc -w original.py
no Python documentation found for 'original.py'

yourcode_dir$ pydoc -w original
wrote original.html

What is the GAC in .NET?

GAC (Global Assembly Cache) is where all shared .NET assembly reside.

Python Pandas: Get index of rows which column matches certain value

First you may check query when the target column is type bool (PS: about how to use it please check link )

df.query('BoolCol')
Out[123]: 
    BoolCol
10     True
40     True
50     True

After we filter the original df by the Boolean column we can pick the index .

df=df.query('BoolCol')
df.index
Out[125]: Int64Index([10, 40, 50], dtype='int64')

Also pandas have nonzero, we just select the position of True row and using it slice the DataFrame or index

df.index[df.BoolCol.nonzero()[0]]
Out[128]: Int64Index([10, 40, 50], dtype='int64')

minimize app to system tray

This is the method I use in my applications, it's fairly simple and self explanatory but I'm happy to give more details in answer to your comments.

    public Form1()
    {
        InitializeComponent();

        // When window state changed, trigger state update.
        this.Resize += SetMinimizeState;

        // When tray icon clicked, trigger window state change.       
        systemTrayIcon.Click += ToggleMinimizeState;
    }      

    // Toggle state between Normal and Minimized.
    private void ToggleMinimizeState(object sender, EventArgs e)
    {    
        bool isMinimized = this.WindowState == FormWindowState.Minimized;
        this.WindowState = (isMinimized) ? FormWindowState.Normal : FormWindowState.Minimized;
    }

    // Show/Hide window and tray icon to match window state.
    private void SetMinimizeState(object sender, EventArgs e)
    {    
        bool isMinimized = this.WindowState == FormWindowState.Minimized;

        this.ShowInTaskbar = !isMinimized;           
        systemTrayIcon.Visible = isMinimized;
        if (isMinimized) systemTrayIcon.ShowBalloonTip(500, "Application", "Application minimized to tray.", ToolTipIcon.Info);
    }

How to start Spyder IDE on Windows

method 1:

spyder3

method 2:

python -c "from spyder.app import start; start.main()"

method 3:

python -m spyder.app.start

How can I make my custom objects Parcelable?

How? With annotations.

You simply annotate a POJO with a special annotation and library does the rest.

Warning!

I'm not sure that Hrisey, Lombok, and other code generation libraries are compatible with Android's new build system. They may or may not play nicely with hot swapping code (i.e. jRebel, Instant Run).

Pros:

  • Code generation libraries save you from the boilerplate source code.
  • Annotations make your class beautiful.

Cons:

  • It works well for simple classes. Making a complex class parcelable may be tricky.
  • Lombok and AspectJ don't play well together. [details]
  • See my warnings.

Hrisey

Warning!

Hrisey has a known issue with Java 8 and therefore cannot be used for Android development nowadays. See #1 Cannot find symbol errors (JDK 8).

Hrisey is based on Lombok. Parcelable class using Hrisey:

@hrisey.Parcelable
public final class POJOClass implements android.os.Parcelable {
    /* Fields, accessors, default constructor */
}

Now you don't need to implement any methods of Parcelable interface. Hrisey will generate all required code during preprocessing phase.

Hrisey in Gradle dependencies:

provided "pl.mg6.hrisey:hrisey:${hrisey.version}"

See here for supported types. The ArrayList is among them.

Install a plugin - Hrisey xor Lombok* - for your IDE and start using its amazing features!

enter image description here
* Don't enable Hrisey and Lombok plugins together or you'll get an error during IDE launch.


Parceler

Parcelable class using Parceler:

@java.org.parceler.Parcel
public class POJOClass {
    /* Fields, accessors, default constructor */
}

To use the generated code, you may reference the generated class directly, or via the Parcels utility class using

public static <T> Parcelable wrap(T input);

To dereference the @Parcel, just call the following method of Parcels class

public static <T> T unwrap(Parcelable input);

Parceler in Gradle dependencies:

compile "org.parceler:parceler-api:${parceler.version}"
provided "org.parceler:parceler:${parceler.version}"

Look in README for supported attribute types.


AutoParcel

AutoParcel is an AutoValue extension that enables Parcelable values generation.

Just add implements Parcelable to your @AutoValue annotated models:

@AutoValue
abstract class POJOClass implements Parcelable {
    /* Note that the class is abstract */
    /* Abstract fields, abstract accessors */

    static POJOClass create(/*abstract fields*/) {
        return new AutoValue_POJOClass(/*abstract fields*/);
    }
}

AutoParcel in Gradle build file:

apply plugin: 'com.android.application'
apply plugin: 'com.neenbedankt.android-apt'

repositories {
    /*...*/
    maven {url "https://clojars.org/repo/"}
}

dependencies {
    apt "frankiesardo:auto-parcel:${autoparcel.version}"
}

PaperParcel

PaperParcel is an annotation processor that automatically generates type-safe Parcelable boilerplate code for Kotlin and Java. PaperParcel supports Kotlin Data Classes, Google's AutoValue via an AutoValue Extension, or just regular Java bean objects.

Usage example from docs.
Annotate your data class with @PaperParcel, implement PaperParcelable, and add a JVM static instance of PaperParcelable.Creator e.g.:

@PaperParcel
public final class Example extends PaperParcelable {
    public static final PaperParcelable.Creator<Example> CREATOR = new PaperParcelable.Creator<>(Example.class);

    private final int test;

    public Example(int test) {
        this.test = test;
    }

    public int getTest() {
        return test;
    }
}

For Kotlin users, see Kotlin Usage; For AutoValue users, see AutoValue Usage.


ParcelableGenerator

ParcelableGenerator (README is written in Chinese and I don't understand it. Contributions to this answer from english-chinese speaking developers are welcome)

Usage example from README.

import com.baoyz.pg.Parcelable;

@Parcelable
public class User {

    private String name;
    private int age;

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public int getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }

}

The android-apt plugin assists in working with annotation processors in combination with Android Studio.

MySQL SELECT WHERE datetime matches day (and not necessarily time)

You can use %:

SELECT * FROM datetable WHERE datecol LIKE '2012-12-25%'

Dynamically add event listener

I aso find this extremely confusing. as @EricMartinez points out Renderer2 listen() returns the function to remove the listener:

ƒ () { return element.removeEventListener(eventName, /** @type {?} */ (handler), false); }

If i´m adding a listener

this.listenToClick = this.renderer.listen('document', 'click', (evt) => {
    alert('Clicking the document');
})

I´d expect my function to execute what i intended, not the total opposite which is remove the listener.

// I´d expect an alert('Clicking the document'); 
this.listenToClick();
// what you actually get is removing the listener, so nothing...

In the given scenario, It´d actually make to more sense to name it like:

// Add listeners
let unlistenGlobal = this.renderer.listen('document', 'click', (evt) => {
    console.log('Clicking the document', evt);
})

let removeSimple = this.renderer.listen(this.myButton.nativeElement, 'click', (evt) => {
    console.log('Clicking the button', evt);
});

There must be a good reason for this but in my opinion it´s very misleading and not intuitive.

Could not install packages due to an EnvironmentError: [WinError 5] Access is denied:

TYPE CMD in search and when the command prompt appears in the BEST MATCH search result right-click on it and select 'Run as Administrator' when the user control window appears select 'Yes'. The command prompt window will appear and you should see "C:/WINDOWS/system32>"

at this point just type what you want, should work!

How to get the file ID so I can perform a download of a file from Google Drive API on Android?

In my opinion the easiest and fastest way to get a Google Drive file ID is from Google Drive on the web. Right-click the file name and select Get shareable link. The last part of the link is the file ID. Then you can cancel the sharing.

SQL Server GROUP BY datetime ignore hour minute and a select with a date and sum value

As he didn't specify which version of SQL server he uses (date type isn't available in 2005), one could also use

SELECT CONVERT(VARCHAR(10),date_column,112),SUM(num_col) AS summed
FROM table_name
GROUP BY CONVERT(VARCHAR(10),date_column,112)

LaTeX table too wide. How to make it fit?

Use p{width} column specifier: e.g. \begin{tabular}{ l p{10cm} } will put column's content into 10cm-wide parbox, and the text will be properly broken to several lines, like in normal paragraph.

You can also use tabular* environment to specify width for the entire table.

Generate Row Serial Numbers in SQL Query

I found one solution for MYSQL its easy to add new column for SrNo or kind of tepropery auto increment column by following this query:

SELECT @ab:=@ab+1 as SrNo, tablename.* FROM tablename, (SELECT @ab:= 0)
AS ab

How to include CSS file in Symfony 2 and Twig?

You are doing everything right, except passing your bundle path to asset() function.

According to documentation - in your example this should look like below:

{{ asset('bundles/webshome/css/main.css') }}

Tip: you also can call assets:install with --symlink key, so it will create symlinks in web folder. This is extremely useful when you often apply js or css changes (in this way your changes, applied to src/YouBundle/Resources/public will be immediately reflected in web folder without need to call assets:install again):

app/console assets:install web --symlink

Also, if you wish to add some assets in your child template, you could call parent() method for the Twig block. In your case it would be like this:

{% block stylesheets %}
    {{ parent() }}

    <link href="{{ asset('bundles/webshome/css/main.css') }}" rel="stylesheet">
{% endblock %}

How to Fill an array from user input C#?

C# does not have a message box that will gather input, but you can use the Visual Basic input box instead.

If you add a reference to "Microsoft Visual Basic .NET Runtime" and then insert:

using Microsoft.VisualBasic;

You can do the following:

List<string> responses = new List<string>();
string response = "";

while(!(response = Interaction.InputBox("Please enter your information",
                                        "Window Title",
                                        "Default Text",
                                        xPosition,
                                        yPosition)).equals(""))
{
   responses.Add(response);
}

responses.ToArray();

PHP Try and Catch for SQL Insert

You can implement throwing exceptions on mysql query fail on your own. What you need is to write a wrapper for mysql_query function, e.g.:

// user defined. corresponding MySQL errno for duplicate key entry
const MYSQL_DUPLICATE_KEY_ENTRY = 1022;

// user defined MySQL exceptions
class MySQLException extends Exception {}
class MySQLDuplicateKeyException extends MySQLException {}

function my_mysql_query($query, $conn=false) {
    $res = mysql_query($query, $conn);
    if (!$res) {
        $errno = mysql_errno($conn);
        $error = mysql_error($conn);
        switch ($errno) {
        case MYSQL_DUPLICATE_KEY_ENTRY:
            throw new MySQLDuplicateKeyException($error, $errno);
            break;
        default:
            throw MySQLException($error, $errno);
            break;
        }
    }
    // ...
    // doing something
    // ...
    if ($something_is_wrong) {
        throw new Exception("Logic exception while performing query result processing");
    }

}

try {
    mysql_query("INSERT INTO redirects SET ua_string = '$ua_string'")
}
catch (MySQLDuplicateKeyException $e) {
    // duplicate entry exception
    $e->getMessage();
}
catch (MySQLException $e) {
    // other mysql exception (not duplicate key entry)
    $e->getMessage();
}
catch (Exception $e) {
    // not a MySQL exception
    $e->getMessage();
}

Google Maps: how to get country, state/province/region, city given a lat/long value?

I used this question as a starting point for my own solution. Thought it was appropriate to contribute my code back since its smaller than tabacitu's

Dependencies:

Code:

if(geoPosition.init()){  

    var foundLocation = function(city, state, country, lat, lon){
        //do stuff with your location! any of the first 3 args may be null
        console.log(arguments);
    }

    var geocoder = new google.maps.Geocoder(); 
    geoPosition.getCurrentPosition(function(r){
        var findResult = function(results, name){
            var result =  _.find(results, function(obj){
                return obj.types[0] == name && obj.types[1] == "political";
            });
            return result ? result.short_name : null;
        };
        geocoder.geocode({'latLng': new google.maps.LatLng(r.coords.latitude, r.coords.longitude)}, function(results, status) {
            if (status == google.maps.GeocoderStatus.OK && results.length) {
                results = results[0].address_components;
                var city = findResult(results, "locality");
                var state = findResult(results, "administrative_area_level_1");
                var country = findResult(results, "country");
                foundLocation(city, state, country, r.coords.latitude, r.coords.longitude);
            } else {
                foundLocation(null, null, null, r.coords.latitude, r.coords.longitude);
            }
        });
    }, { enableHighAccuracy:false, maximumAge: 1000 * 60 * 1 });
}

remove space between paragraph and unordered list

You can use CSS selectors in a way similar to the following:

p + ul {
    margin-top: -10px;
}

This could be helpful because p + ul means select any <ul> element after a <p> element.

You'll have to adapt this to how much padding or margin you have on your <p> tags generally.

Original answer to original question:

p, ul {
    padding: 0;
    margin: 0;
}

That will take any EXTRA white space away.

p, ul {
    display: inline;
}

That will make all the elements inline instead of blocks. (So, for instance, the <p> won't cause a line break before and after it.)

How to get all Errors from ASP.Net MVC modelState?

var x = new Dictionary<string,string>();
for (var b = 0; b < ViewData.ModelState.Values.Count(); b++)
{
    if (ViewData.ModelState.Values.ElementAt(b).Errors.Count() > 0)
        x.Add(ViewData.ModelState.Keys.ElementAt(b), String.Join(",", ViewData
            .ModelState.Values.ElementAt(b).Errors.Select(c => c.ErrorMessage)));
}

Console errors. Failed to load resource: net::ERR_INSECURE_RESPONSE

If you use chrome, you can make a shortcut,right click and edit the shortcut's target, append this after target's string:

--ignore-certificate-errors

The complete string looks like this:

"C:\Program Files (x86)\Google\Chrome\Application\chrome.exe" --ignore-certificate-errors

How do I specify "close existing connections" in sql script

You can disconnect everyone and roll back their transactions with:

alter database [MyDatbase] set single_user with rollback immediate

After that, you can safely drop the database :)

Javascript to convert UTC to local time

/*
 * convert server time to local time
 *  simbu
*/
function convertTime(serverdate) {
    var date = new Date(serverdate);
    // convert to utc time
    var toutc = date.toUTCString();
    //convert to local time
    var locdat = new Date(toutc + " UTC");
    return locdat;
}

Remove item from list based on condition

Using linq:

prods.Remove( prods.Single( s => s.ID == 1 ) );

Maybe you even want to use SingleOrDefault() and check if the element exists at all ...

EDIT:
Since stuff is a struct, SingleOrDefault() will not return null. But it will return default( stuff ), which will have an ID of 0. When you don't have an ID of 0 for your normal stuff-objects you can query for this ID:

var stuffToRemove = prods.SingleOrDefault( s => s.ID == 1 )
if( stuffToRemove.ID != 0 )
{
    prods.Remove( stuffToRemove );
}

Error: invalid operands of types ‘const char [35]’ and ‘const char [2]’ to binary ‘operator+’

Consider this:

std::string str = "Hello " + "world"; // bad!

Both the rhs and the lhs for operator + are char*s. There is no definition of operator + that takes two char*s (in fact, the language doesn't permit you to write one). As a result, on my compiler this produces a "cannot add two pointers" error (yours apparently phrases things in terms of arrays, but it's the same problem).

Now consider this:

std::string str = "Hello " + std::string("world"); // ok

There is a definition of operator + that takes a const char* as the lhs and a std::string as the rhs, so now everyone is happy.

You can extend this to as long a concatenation chain as you like. It can get messy, though. For example:

std::string str = "Hello " + "there " + std::string("world"); // no good!

This doesn't work because you are trying to + two char*s before the lhs has been converted to std::string. But this is fine:

std::string str = std::string("Hello ") + "there " + "world"; // ok

Because once you've converted to std::string, you can + as many additional char*s as you want.

If that's still confusing, it may help to add some brackets to highlight the associativity rules and then replace the variable names with their types:

((std::string("Hello ") + "there ") + "world");
((string + char*) + char*)

The first step is to call string operator+(string, char*), which is defined in the standard library. Replacing those two operands with their result gives:

((string) + char*)

Which is exactly what we just did, and which is still legal. But try the same thing with:

((char* + char*) + string)

And you're stuck, because the first operation tries to add two char*s.

Moral of the story: If you want to be sure a concatenation chain will work, just make sure one of the first two arguments is explicitly of type std::string.

Select All Rows Using Entity Framework

You can use this code to select all rows :

C# :

var allStudents = [modelname].[tablename].Select(x => x).ToList();

How do I display a wordpress page content?

@Sydney Try putting wp_reset_query() before you call the loop. This will display the content of your page.

<?php
    wp_reset_query(); // necessary to reset query
    while ( have_posts() ) : the_post();
        the_content();
    endwhile; // End of the loop.
?>

EDIT: Try this if you have some other loops that you previously ran. Place wp_reset_query(); where you find it most suitable, but before you call this loop.

'cannot find or open the pdb file' Visual Studio C++ 2013

No problem. You're running your code under the debugger, and the debugger is telling you that it doesn't have debugging information for the system libraries.

If you really need that (usually for stack traces), you can download it from Microsoft's symbol servers, but for now you don't need to worry.

MyISAM versus InnoDB

Slightly off-topic, but for documentation purposes and completeness, I would like to add the following.

In general using InnoDB will result in a much LESS complex application, probably also more bug-free. Because you can put all referential integrity (Foreign Key-constraints) into the datamodel, you don't need anywhere near as much application code as you will need with MyISAM.

Every time you insert, delete or replace a record, you will HAVE to check and maintain the relationships. E.g. if you delete a parent, all children should be deleted too. For instance, even in a simple blogging system, if you delete a blogposting record, you will have to delete the comment records, the likes, etc. In InnoDB this is done automatically by the database engine (if you specified the contraints in the model) and requires no application code. In MyISAM this will have to be coded into the application, which is very difficult in web-servers. Web-servers are by nature very concurrent / parallel and because these actions should be atomical and MyISAM supports no real transactions, using MyISAM for web-servers is risky / error-prone.

Also in most general cases, InnoDB will perform much better, for a multiple of reasons, one them being able to use record level locking as opposed to table-level locking. Not only in a situation where writes are more frequent than reads, also in situations with complex joins on large datasets. We noticed a 3 fold performance increase just by using InnoDB tables over MyISAM tables for very large joins (taking several minutes).

I would say that in general InnoDB (using a 3NF datamodel complete with referential integrity) should be the default choice when using MySQL. MyISAM should only be used in very specific cases. It will most likely perform less, result in a bigger and more buggy application.

Having said this. Datamodelling is an art seldom found among webdesigners / -programmers. No offence, but it does explain MyISAM being used so much.

Set database from SINGLE USER mode to MULTI USER

I had the same issue and it fixed by the following steps - reference: http://giladka8.blogspot.com.au/2011/11/database-is-in-single-user-mode-and.html

use master
GO

select 
    d.name, 
    d.dbid, 
    spid, 
    login_time, 
    nt_domain, 
    nt_username, 
    loginame
from sysprocesses p 
    inner join sysdatabases d 
        on p.dbid = d.dbid
where d.name = 'dbname'
GO

kill 56 --=> kill the number in spid field
GO

exec sp_dboption 'dbname', 'single user', 'FALSE'
GO

Chrome/jQuery Uncaught RangeError: Maximum call stack size exceeded

You can also get this error when you have an infinite loop. Make sure that you don't have any unending, recursive self references.

Spring Boot - How to log all requests and responses with exceptions in single place?

I had defined logging level in application.properties to print requests/responses, method url in the log file

logging.level.org.springframework.web=DEBUG
logging.level.org.hibernate.SQL=INFO
logging.file=D:/log/myapp.log

I had used Spring Boot.