Programs & Examples On #Typedef

In C and C++, the typedef keyword allows you to create an alias for a known data type.

Typedef function pointer?

  1. typedef is used to alias types; in this case you're aliasing FunctionFunc to void(*)().

  2. Indeed the syntax does look odd, have a look at this:

    typedef   void      (*FunctionFunc)  ( );
    //         ^                ^         ^
    //     return type      type name  arguments
    
  3. No, this simply tells the compiler that the FunctionFunc type will be a function pointer, it doesn't define one, like this:

    FunctionFunc x;
    void doSomething() { printf("Hello there\n"); }
    x = &doSomething;
    
    x(); //prints "Hello there"
    

typedef fixed length array

To use the array type properly as a function argument or template parameter, make a struct instead of a typedef, then add an operator[] to the struct so you can keep the array like functionality like so:

typedef struct type24 {
  char& operator[](int i) { return byte[i]; }
  char byte[3];
} type24;

type24 x;
x[2] = 'r';
char c = x[2];

dereferencing pointer to incomplete type

Another possible reason is indirect reference. If a code references to a struct that not included in current c file, the compiler will complain.

a->b->c //error if b not included in current c file

uint8_t vs unsigned char

That is really important for example when you are writing a network analyzer. packet headers are defined by the protocol specification, not by the way a particular platform's C compiler works.

Overloading operators in typedef structs (c++)

The breakdown of your declaration and its members is somewhat littered:

Remove the typedef

The typedef is neither required, not desired for class/struct declarations in C++. Your members have no knowledge of the declaration of pos as-written, which is core to your current compilation failure.

Change this:

typedef struct {....} pos;

To this:

struct pos { ... };

Remove extraneous inlines

You're both declaring and defining your member operators within the class definition itself. The inline keyword is not needed so long as your implementations remain in their current location (the class definition)


Return references to *this where appropriate

This is related to an abundance of copy-constructions within your implementation that should not be done without a strong reason for doing so. It is related to the expression ideology of the following:

a = b = c;

This assigns c to b, and the resulting value b is then assigned to a. This is not equivalent to the following code, contrary to what you may think:

a = c;
b = c;

Therefore, your assignment operator should be implemented as such:

pos& operator =(const pos& a)
{
    x = a.x;
    y = a.y;
    return *this;
}

Even here, this is not needed. The default copy-assignment operator will do the above for you free of charge (and code! woot!)

Note: there are times where the above should be avoided in favor of the copy/swap idiom. Though not needed for this specific case, it may look like this:

pos& operator=(pos a) // by-value param invokes class copy-ctor
{
    this->swap(a);
    return *this;
}

Then a swap method is implemented:

void pos::swap(pos& obj)
{
    // TODO: swap object guts with obj
}

You do this to utilize the class copy-ctor to make a copy, then utilize exception-safe swapping to perform the exchange. The result is the incoming copy departs (and destroys) your object's old guts, while your object assumes ownership of there's. Read more the copy/swap idiom here, along with the pros and cons therein.


Pass objects by const reference when appropriate

All of your input parameters to all of your members are currently making copies of whatever is being passed at invoke. While it may be trivial for code like this, it can be very expensive for larger object types. An exampleis given here:

Change this:

bool operator==(pos a) const{
    if(a.x==x && a.y== y)return true;
    else return false;
}

To this: (also simplified)

bool operator==(const pos& a) const
{
    return (x == a.x && y == a.y);
}

No copies of anything are made, resulting in more efficient code.


Finally, in answering your question, what is the difference between a member function or operator declared as const and one that is not?

A const member declares that invoking that member will not modifying the underlying object (mutable declarations not withstanding). Only const member functions can be invoked against const objects, or const references and pointers. For example, your operator +() does not modify your local object and thus should be declared as const. Your operator =() clearly modifies the local object, and therefore the operator should not be const.


Summary

struct pos
{
    int x;
    int y;

    // default + parameterized constructor
    pos(int x=0, int y=0) 
        : x(x), y(y)
    {
    }

    // assignment operator modifies object, therefore non-const
    pos& operator=(const pos& a)
    {
        x=a.x;
        y=a.y;
        return *this;
    }

    // addop. doesn't modify object. therefore const.
    pos operator+(const pos& a) const
    {
        return pos(a.x+x, a.y+y);
    }

    // equality comparison. doesn't modify object. therefore const.
    bool operator==(const pos& a) const
    {
        return (x == a.x && y == a.y);
    }
};

EDIT OP wanted to see how an assignment operator chain works. The following demonstrates how this:

a = b = c;

Is equivalent to this:

b = c;
a = b;

And that this does not always equate to this:

a = c;
b = c;

Sample code:

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

struct obj
{
    std::string name;
    int value;

    obj(const std::string& name, int value)
        : name(name), value(value)
    {
    }

    obj& operator =(const obj& o)
    {
        cout << name << " = " << o.name << endl;
        value = (o.value+1); // note: our value is one more than the rhs.
        return *this;
    }    
};

int main(int argc, char *argv[])
{

    obj a("a", 1), b("b", 2), c("c", 3);

    a = b = c;
    cout << "a.value = " << a.value << endl;
    cout << "b.value = " << b.value << endl;
    cout << "c.value = " << c.value << endl;

    a = c;
    b = c;
    cout << "a.value = " << a.value << endl;
    cout << "b.value = " << b.value << endl;
    cout << "c.value = " << c.value << endl;

    return 0;
}

Output

b = c
a = b
a.value = 5
b.value = 4
c.value = 3
a = c
b = c
a.value = 4
b.value = 4
c.value = 3

Understanding typedefs for function pointers in C

A function pointer is like any other pointer, but it points to the address of a function instead of the address of data (on heap or stack). Like any pointer, it needs to be typed correctly. Functions are defined by their return value and the types of parameters they accept. So in order to fully describe a function, you must include its return value and the type of each parameter is accepts. When you typedef such a definition, you give it a 'friendly name' which makes it easier to create and reference pointers using that definition.

So for example assume you have a function:

float doMultiplication (float num1, float num2 ) {
    return num1 * num2; }

then the following typedef:

typedef float(*pt2Func)(float, float);

can be used to point to this doMulitplication function. It is simply defining a pointer to a function which returns a float and takes two parameters, each of type float. This definition has the friendly name pt2Func. Note that pt2Func can point to ANY function which returns a float and takes in 2 floats.

So you can create a pointer which points to the doMultiplication function as follows:

pt2Func *myFnPtr = &doMultiplication;

and you can invoke the function using this pointer as follows:

float result = (*myFnPtr)(2.0, 5.1);

This makes good reading: http://www.newty.de/fpt/index.html

Convert objective-c typedef to its string equivalent

Depending on your needs, you could alternatively use compiler directives to simulate the behaviour you are looking for.

 #define JSON @"JSON"
 #define XML @"XML"
 #define Atom @"Atom"
 #define RSS @"RSS"

Just remember the usual compiler shortcomings, (not type safe, direct copy-paste makes source file larger)

What is a typedef enum in Objective-C?

A typedef allows the programmer to define one Objective-C type as another. For example,

typedef int Counter; defines the type Counter to be equivalent to the int type. This drastically improves code readability.

self referential struct definition?

There is sort of a way around this:

struct Cell {
  bool isParent;
  struct Cell* child;
};

struct Cell;
typedef struct Cell Cell;

If you declare it like this, it properly tells the compiler that struct Cell and plain-ol'-cell are the same. So you can use Cell just like normal. Still have to use struct Cell inside of the initial declaration itself though.

Equivalent of typedef in C#

Both C++ and C# are missing easy ways to create a new type which is semantically identical to an exisiting type. I find such 'typedefs' totally essential for type-safe programming and its a real shame c# doesn't have them built-in. The difference between void f(string connectionID, string username) to void f(ConID connectionID, UserName username) is obvious ...

(You can achieve something similar in C++ with boost in BOOST_STRONG_TYPEDEF)

It may be tempting to use inheritance but that has some major limitations:

  • it will not work for primitive types
  • the derived type can still be casted to the original type, ie we can send it to a function receiving our original type, this defeats the whole purpose
  • we cannot derive from sealed classes (and ie many .NET classes are sealed)

The only way to achieve a similar thing in C# is by composing our type in a new class:

Class SomeType { 
  public void Method() { .. }
}

sealed Class SomeTypeTypeDef {
  public SomeTypeTypeDef(SomeType composed) { this.Composed = composed; }

  private SomeType Composed { get; }

  public override string ToString() => Composed.ToString();
  public override int GetHashCode() => HashCode.Combine(Composed);
  public override bool Equals(object obj) => obj is TDerived o && Composed.Equals(o.Composed); 
  public bool Equals(SomeTypeTypeDefo) => object.Equals(this, o);

  // proxy the methods we want
  public void Method() => Composed.Method();
}

While this will work it is very verbose for just a typedef. In addition we have a problem with serializing (ie to Json) as we want to serialize the class through its Composed property.

Below is a helper class that uses the "Curiously Recurring Template Pattern" to make this much simpler:

namespace Typedef {

  [JsonConverter(typeof(JsonCompositionConverter))]
  public abstract class Composer<TDerived, T> : IEquatable<TDerived> where TDerived : Composer<TDerived, T> {
    protected Composer(T composed) { this.Composed = composed; }
    protected Composer(TDerived d) { this.Composed = d.Composed; }

    protected T Composed { get; }

    public override string ToString() => Composed.ToString();
    public override int GetHashCode() => HashCode.Combine(Composed);
    public override bool Equals(object obj) => obj is Composer<TDerived, T> o && Composed.Equals(o.Composed); 
    public bool Equals(TDerived o) => object.Equals(this, o);
  }

  class JsonCompositionConverter : JsonConverter {
    static FieldInfo GetCompositorField(Type t) {
      var fields = t.BaseType.GetFields(BindingFlags.Instance | BindingFlags.NonPublic | BindingFlags.Public | BindingFlags.FlattenHierarchy);
      if (fields.Length!=1) throw new JsonSerializationException();
      return fields[0];
    }

    public override bool CanConvert(Type t) {
      var fields = t.GetFields(BindingFlags.Instance | BindingFlags.NonPublic | BindingFlags.Public | BindingFlags.FlattenHierarchy);
      return fields.Length == 1;
    }

    // assumes Compositor<T> has either a constructor accepting T or an empty constructor
    public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer) {
      while (reader.TokenType == JsonToken.Comment && reader.Read()) { };
      if (reader.TokenType == JsonToken.Null) return null; 
      var compositorField = GetCompositorField(objectType);
      var compositorType = compositorField.FieldType;
      var compositorValue = serializer.Deserialize(reader, compositorType);
      var ctorT = objectType.GetConstructor(new Type[] { compositorType });
      if (!(ctorT is null)) return Activator.CreateInstance(objectType, compositorValue);
      var ctorEmpty = objectType.GetConstructor(new Type[] { });
      if (ctorEmpty is null) throw new JsonSerializationException();
      var res = Activator.CreateInstance(objectType);
      compositorField.SetValue(res, compositorValue);
      return res;
    }

    public override void WriteJson(JsonWriter writer, object o, JsonSerializer serializer) {
      var compositorField = GetCompositorField(o.GetType());
      var value = compositorField.GetValue(o);
      serializer.Serialize(writer, value);
    }
  }

}

With Composer the above class becomes simply:

sealed Class SomeTypeTypeDef : Composer<SomeTypeTypeDef, SomeType> {
   public SomeTypeTypeDef(SomeType composed) : base(composed) {}

   // proxy the methods we want
   public void Method() => Composed.Method();
}

And in addition the SomeTypeTypeDef will serialize to Json in the same way that SomeType does.

Hope this helps !

Forward declaration of a typedef in C++

Because to declare a type, its size needs to be known. You can forward declare a pointer to the type, or typedef a pointer to the type.

If you really want to, you can use the pimpl idiom to keep the includes down. But if you want to use a type, rather than a pointer, the compiler has to know its size.

Edit: j_random_hacker adds an important qualification to this answer, basically that the size needs to be know to use the type, but a forward declaration can be made if we only need to know the type exists, in order to create pointers or references to the type. Since the OP didn't show code, but complained it wouldn't compile, I assumed (probably correctly) that the OP was trying to use the type, not just refer to it.

typedef struct vs struct definitions

You can't use forward declaration with the typedef struct.

The struct itself is an anonymous type, so you don't have an actual name to forward declare.

typedef struct{
    int one;
    int two;
} myStruct;

A forward declaration like this won't work:

struct myStruct; //forward declaration fails

void blah(myStruct* pStruct);

//error C2371: 'myStruct' : redefinition; different basic types

invalid use of incomplete type

You derive B from A<B>, so the first thing the compiler does, once it sees the definition of class B is to try to instantiate A<B>. To do this it needs to known B::mytype for the parameter of action. But since the compiler is just in the process of figuring out the actual definition of B, it doesn't know this type yet and you get an error.

One way around this is would be to declare the parameter type as another template parameter, instead of inside the derived class:

template<typename Subclass, typename Param>
class A {
    public:
        void action(Param var) {
                (static_cast<Subclass*>(this))->do_action(var);
        }
};

class B : public A<B, int> { ... };

Difference between 'struct' and 'typedef struct' in C++?

You can't use forward declaration with the typedef struct.

The struct itself is an anonymous type, so you don't have an actual name to forward declare.

typedef struct{
    int one;
    int two;
}myStruct;

A forward declaration like this wont work:

struct myStruct; //forward declaration fails

void blah(myStruct* pStruct);

//error C2371: 'myStruct' : redefinition; different basic types

Why should we typedef a struct so often in C?

From an old article by Dan Saks (http://www.ddj.com/cpp/184403396?pgno=3):


The C language rules for naming structs are a little eccentric, but they're pretty harmless. However, when extended to classes in C++, those same rules open little cracks for bugs to crawl through.

In C, the name s appearing in

struct s
    {
    ...
    };

is a tag. A tag name is not a type name. Given the definition above, declarations such as

s x;    /* error in C */
s *p;   /* error in C */

are errors in C. You must write them as

struct s x;     /* OK */
struct s *p;    /* OK */

The names of unions and enumerations are also tags rather than types.

In C, tags are distinct from all other names (for functions, types, variables, and enumeration constants). C compilers maintain tags in a symbol table that's conceptually if not physically separate from the table that holds all other names. Thus, it is possible for a C program to have both a tag and an another name with the same spelling in the same scope. For example,

struct s s;

is a valid declaration which declares variable s of type struct s. It may not be good practice, but C compilers must accept it. I have never seen a rationale for why C was designed this way. I have always thought it was a mistake, but there it is.

Many programmers (including yours truly) prefer to think of struct names as type names, so they define an alias for the tag using a typedef. For example, defining

struct s
    {
    ...
    };
typedef struct s S;

lets you use S in place of struct s, as in

S x;
S *p;

A program cannot use S as the name of both a type and a variable (or function or enumeration constant):

S S;    // error

This is good.

The tag name in a struct, union, or enum definition is optional. Many programmers fold the struct definition into the typedef and dispense with the tag altogether, as in:

typedef struct
    {
    ...
    } S;

The linked article also has a discussion about how the C++ behavior of not requireing a typedef can cause subtle name hiding problems. To prevent these problems, it's a good idea to typedef your classes and structs in C++, too, even though at first glance it appears to be unnecessary. In C++, with the typedef the name hiding become an error that the compiler tells you about rather than a hidden source of potential problems.

What is the difference between 'typedef' and 'using' in C++11?

The using syntax has an advantage when used within templates. If you need the type abstraction, but also need to keep template parameter to be possible to be specified in future. You should write something like this.

template <typename T> struct whatever {};

template <typename T> struct rebind
{
  typedef whatever<T> type; // to make it possible to substitue the whatever in future.
};

rebind<int>::type variable;

template <typename U> struct bar { typename rebind<U>::type _var_member; }

But using syntax simplifies this use case.

template <typename T> using my_type = whatever<T>;

my_type<int> variable;
template <typename U> struct baz { my_type<U> _var_member; }

C++ template typedef

C++11 added alias declarations, which are generalization of typedef, allowing templates:

template <size_t N>
using Vector = Matrix<N, 1>;

The type Vector<3> is equivalent to Matrix<3, 1>.


In C++03, the closest approximation was:

template <size_t N>
struct Vector
{
    typedef Matrix<N, 1> type;
};

Here, the type Vector<3>::type is equivalent to Matrix<3, 1>.

Is there a Java equivalent or methodology for the typedef keyword in C++?

You could use an Enum, although that's semantically a bit different than a typedef in that it only allows a restricted set of values. Another possible solution is a named wrapper class, e.g.

public class Apple {
      public Apple(Integer i){this.i=i; }
}

but that seems way more clunky, especially given that it's not clear from the code that the class has no other function than as an alias.

How do I use typedef and typedef enum in C?

typedef enum state {DEAD,ALIVE} State;
|     | |                     | |   |^ terminating semicolon, required! 
|     | |   type specifier    | |   |
|     | |                     | ^^^^^  declarator (simple name)
|     | |                     |    
|     | ^^^^^^^^^^^^^^^^^^^^^^^  
|     |
^^^^^^^-- storage class specifier (in this case typedef)

The typedef keyword is a pseudo-storage-class specifier. Syntactically, it is used in the same place where a storage class specifier like extern or static is used. It doesn't have anything to do with storage. It means that the declaration doesn't introduce the existence of named objects, but rather, it introduces names which are type aliases.

After the above declaration, the State identifier becomes an alias for the type enum state {DEAD,ALIVE}. The declaration also provides that type itself. However that isn't typedef doing it. Any declaration in which enum state {DEAD,ALIVE} appears as a type specifier introduces that type into the scope:

enum state {DEAD, ALIVE} stateVariable;

If enum state has previously been introduced the typedef has to be written like this:

typedef enum state State;

otherwise the enum is being redefined, which is an error.

Like other declarations (except function parameter declarations), the typedef declaration can have multiple declarators, separated by a comma. Moreover, they can be derived declarators, not only simple names:

typedef unsigned long ulong, *ulongptr;
|     | |           | |  1 | |   2   |
|     | |           | |    | ^^^^^^^^^--- "pointer to" declarator
|     | |           | ^^^^^^------------- simple declarator
|     | ^^^^^^^^^^^^^-------------------- specifier-qualifier list
^^^^^^^---------------------------------- storage class specifier

This typedef introduces two type names ulong and ulongptr, based on the unsigned long type given in the specifier-qualifier list. ulong is just a straight alias for that type. ulongptr is declared as a pointer to unsigned long, thanks to the * syntax, which in this role is a kind of type construction operator which deliberately mimics the unary * for pointer dereferencing used in expressions. In other words ulongptr is an alias for the "pointer to unsigned long" type.

Alias means that ulongptr is not a distinct type from unsigned long *. This is valid code, requiring no diagnostic:

unsigned long *p = 0;
ulongptr q = p;

The variables q and p have exactly the same type.

The aliasing of typedef isn't textual. For instance if user_id_t is a typedef name for the type int, we may not simply do this:

unsigned user_id_t uid;  // error! programmer hoped for "unsigned int uid". 

This is an invalid type specifier list, combining unsigned with a typedef name. The above can be done using the C preprocessor:

#define user_id_t int
unsigned user_id_t uid;

whereby user_id_t is macro-expanded to the token int prior to syntax analysis and translation. While this may seem like an advantage, it is a false one; avoid this in new programs.

Among the disadvantages that it doesn't work well for derived types:

 #define silly_macro int *

 silly_macro not, what, you, think;

This declaration doesn't declare what, you and think as being of type "pointer to int" because the macro-expansion is:

 int * not, what, you, think;

The type specifier is int, and the declarators are *not, what, you and think. So not has the expected pointer type, but the remaining identifiers do not.

And that's probably 99% of everything about typedef and type aliasing in C.

How to order results with findBy() in Doctrine

$cRepo = $em->getRepository('KaleLocationBundle:Country');

// Leave the first array blank
$countries = $cRepo->findBy(array(), array('name'=>'asc'));

How does the "view" method work in PyTorch?

Let's do some examples, from simpler to more difficult.

  1. The view method returns a tensor with the same data as the self tensor (which means that the returned tensor has the same number of elements), but with a different shape. For example:

    a = torch.arange(1, 17)  # a's shape is (16,)
    
    a.view(4, 4) # output below
      1   2   3   4
      5   6   7   8
      9  10  11  12
     13  14  15  16
    [torch.FloatTensor of size 4x4]
    
    a.view(2, 2, 4) # output below
    (0 ,.,.) = 
    1   2   3   4
    5   6   7   8
    
    (1 ,.,.) = 
     9  10  11  12
    13  14  15  16
    [torch.FloatTensor of size 2x2x4]
    
  2. Assuming that -1 is not one of the parameters, when you multiply them together, the result must be equal to the number of elements in the tensor. If you do: a.view(3, 3), it will raise a RuntimeError because shape (3 x 3) is invalid for input with 16 elements. In other words: 3 x 3 does not equal 16 but 9.

  3. You can use -1 as one of the parameters that you pass to the function, but only once. All that happens is that the method will do the math for you on how to fill that dimension. For example a.view(2, -1, 4) is equivalent to a.view(2, 2, 4). [16 / (2 x 4) = 2]

  4. Notice that the returned tensor shares the same data. If you make a change in the "view" you are changing the original tensor's data:

    b = a.view(4, 4)
    b[0, 2] = 2
    a[2] == 3.0
    False
    
  5. Now, for a more complex use case. The documentation says that each new view dimension must either be a subspace of an original dimension, or only span d, d + 1, ..., d + k that satisfy the following contiguity-like condition that for all i = 0, ..., k - 1, stride[i] = stride[i + 1] x size[i + 1]. Otherwise, contiguous() needs to be called before the tensor can be viewed. For example:

    a = torch.rand(5, 4, 3, 2) # size (5, 4, 3, 2)
    a_t = a.permute(0, 2, 3, 1) # size (5, 3, 2, 4)
    
    # The commented line below will raise a RuntimeError, because one dimension
    # spans across two contiguous subspaces
    # a_t.view(-1, 4)
    
    # instead do:
    a_t.contiguous().view(-1, 4)
    
    # To see why the first one does not work and the second does,
    # compare a.stride() and a_t.stride()
    a.stride() # (24, 6, 2, 1)
    a_t.stride() # (24, 2, 1, 6)
    

    Notice that for a_t, stride[0] != stride[1] x size[1] since 24 != 2 x 3

An error occurred while updating the entries. See the inner exception for details

Click "View Detail..." a window will open where you can expand the "Inner Exception" my guess is that when you try to delete the record there is a reference constraint violation. The inner exception will give you more information on that so you can modify your code to remove any references prior to deleting the record.

enter image description here

How can I get the current date and time in UTC or GMT in Java?

If you want a Date object with fields adjusted for UTC you can do it like this with Joda Time:

import org.joda.time.DateTimeZone;
import java.util.Date;

...

Date local = new Date();
System.out.println("Local: " + local);
DateTimeZone zone = DateTimeZone.getDefault();
long utc = zone.convertLocalToUTC(local.getTime(), false);
System.out.println("UTC: " + new Date(utc));

Android Button click go to another xml page

Change your FirstyActivity to:

@Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Button btn_go=(Button)findViewById(R.id.YOUR_BUTTON_ID);
            btn_go.setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub
                  Log.i("clicks","You Clicked B1");
              Intent i=new Intent(
                     MainActivity.this,
                     MainActivity2.class);
              startActivity(i);
            }
        }
    });

}

Hope it will help you.

What's the point of 'meta viewport user-scalable=no' in the Google Maps API

Disabling user-scalable (namely, the ability to double tap to zoom) allows the browser to reduce the click delay. In touch-enable browsers, when the user expects the double tap to zoom, the browser generally waits 300ms before firing the click event, waiting to see if the user will double tap. Disabling user-scalable allows for the Chrome browser to fire the click event immediately, allowing for a better user experience.

From Google IO 2013 session https://www.youtube.com/watch?feature=player_embedded&v=DujfpXOKUp8#t=1435s

Update: its not true anymore, <meta name="viewport" content="width=device-width"> is enough to remove 300ms delay

What is meant by immutable?

Actually String is not immutable if you use the wikipedia definition suggested above.

String's state does change post construction. Take a look at the hashcode() method. String caches the hashcode value in a local field but does not calculate it until the first call of hashcode(). This lazy evaluation of hashcode places String in an interesting position as an immutable object whose state changes, but it cannot be observed to have changed without using reflection.

So maybe the definition of immutable should be an object that cannot be observed to have changed.

If the state changes in an immutable object after it has been created but no-one can see it (without reflection) is the object still immutable?

cor shows only NA or 1 for correlations - Why?

NAs also appear if there are attributes with zero variance (with all elements equal); see for instance:

cor(cbind(a=runif(10),b=rep(1,10)))

which returns:

   a  b
a  1 NA
b NA  1
Warning message:
In cor(cbind(a = runif(10), b = rep(1, 10))) :
  the standard deviation is zero

Do I really need to encode '&' as '&amp;'?

Validation aside, the fact remains that encoding certain characters is important to an HTML document so that it can render properly and safely as a web page.

Encoding & as &amp; under all circumstances, for me, is an easier rule to live by, reducing the likelihood of errors and failures.

Compare the following: which is easier? which is easier to bugger up?

Methodology 1

  1. Write some content which includes ampersand characters.
  2. Encode them all.

Methodology 2

(with a grain of salt, please ;) )

  1. Write some content which includes a ampersand characters.
  2. On a case-by-case basis, look at each ampersand. Determine if:
    • It is isolated, and as such unambiguously an ampersand. eg. volt & amp
       > In that case don't bother encoding it.
    • It is not isolated, but you feel it is nonetheless unambiguous, as the resulting entity does not exist and will never exist since the entity list could never evolve. eg amp&volt
       > In that case don't bother encoding it.
    • It is not isolated, and ambiguous. eg. volt&amp
       > Encode it.

??

Linq on DataTable: select specific column into datatable, not whole table

Here I get only three specific columns from mainDataTable and use the filter

DataTable checkedParams = mainDataTable.Select("checked = true").CopyToDataTable()
.DefaultView.ToTable(false, "lagerID", "reservePeriod", "discount");

Python send POST with header

If we want to add custom HTTP headers to a POST request, we must pass them through a dictionary to the headers parameter.

Here is an example with a non-empty body and headers:

import requests
import json

url = 'https://somedomain.com'
body = {'name': 'Maryja'}
headers = {'content-type': 'application/json'}

r = requests.post(url, data=json.dumps(body), headers=headers)

Source

How to check if character is a letter in Javascript?

With respect to those special characters not being taken into account by simpler checks such as /[a-zA-Z]/.test(c), it can be beneficial to leverage ECMAScript case transformation (toUpperCase). It will take into account non-ASCII Unicode character classes of some foreign alphabets.

function isLetter(c) {
  return c.toLowerCase() != c.toUpperCase();
}

NOTE: this solution will work only for most Latin, Greek, Armenian and Cyrillic scripts. It will NOT work for Chinese, Japanese, Arabic, Hebrew and most other scripts.

Impact of Xcode build options "Enable bitcode" Yes/No

Bitcode is a new feature of iOS 9

Bitcode is an intermediate representation of a compiled program. Apps you upload to iTunes Connect that contain bitcode will be compiled and linked on the App Store. Including bitcode will allow Apple to re-optimize your app binary in the future without the need to submit a new version of your app to the store.

Note: For iOS apps, bitcode is the default, but optional. If you provide bitcode, all apps and frameworks in the app bundle need to include bitcode. For watchOS apps, bitcode is required

So you should disabled bitcode until all the frameworks of your app have bitcode enabled.

No 'Access-Control-Allow-Origin' header is present on the requested resource. Origin '...' is therefore not allowed access

Why the error is raised:

JavaScript code is limited by the same-origin policy, meaning, from a page at www.example.com, you can only make (AJAX) requests to services located at exactly the same domain, in that case, exactly www.example.com (not example.com - without the www - or whatever.example.com).

In your case, your Ajax code is trying to reach a service in http://wordicious.com from a page located at http://www.wordicious.com.

Although very similar, they are not the same domain. And when they are not on the same domain, the request will only be successful if the target's respose contains a Access-Control-Allow-Origin header in it.

As your page/service at http://wordicious.com was never configured to present such header, that error message is shown.

Solution:

As said, the origin (where the page with JavaScript is at) and the target (where the JavaScript is trying to reach) domains must be the exact same.

Your case seems like a typo. Looks like http://wordicious.com and http://www.wordicious.com are actually the same server/domain. So to fix, type the target and the origin equally: make you Ajax code request pages/services to http://www.wordicious.com not http://wordicious.com. (Maybe place the target URL relatively, like '/login.php', without the domain).



On a more general note:

If the problem is not a typo like the one of this question seems to be, the solution would be to add the Access-Control-Allow-Origin to the target domain. To add it, depends, of course, of the server/language behind that address. Sometimes a configuration variable in the tool will do the trick. Other times you'll have to add the headers through code yourself.

Email address validation using ASP.NET MVC data type attributes

Used the above code in MVC5 project and it works completely fine with the validation error. Just try this code:

   [Required]
   [Display(Name = "Email")]
   [EmailAddress]

   [RegularExpression(@"^([A-Za-z0-9][^'!&\\#*$%^?<>()+=:;`~\[\]{}|/,?€@ ][a-zA-z0- 
    9-._][^!&\\#*$%^?<>()+=:;`~\[\]{}|/,?€@ ]*\@[a-zA-Z0-9][^!&@\\#*$%^?<> 
        ()+=':;~`.\[\]{}|/,?€ ]*\.[a-zA-Z]{2,6})$", ErrorMessage = "Please enter a 
   valid Email")]


   public string ReceiverMail { get; set; }

Fit image to table cell [Pure HTML]

Inline content leaves space at the bottom for characters that descend (j, y, q):

https://developer.mozilla.org/en-US/docs/Images,_Tables,_and_Mysterious_Gaps

There are a couple fixes:

Use display: block;

<img style="display:block;" width="100%" height="100%" src="http://dummyimage.com/68x68/000/fff" />

or use vertical-align: bottom;

<img style="vertical-align: bottom;" width="100%" height="100%" src="http://dummyimage.com/68x68/000/fff" />

How to use JavaScript regex over multiple lines?

[\\w\\s]*

This one was beyond helpful for me, especially for matching multiple things that include new lines, every single other answer ended up just grouping all of the matches together.

Search all of Git history for a string?

Try the following commands to search the string inside all previous tracked files:

git log --patch  | less +/searching_string

or

git rev-list --all | GIT_PAGER=cat xargs git grep 'search_string'

which needs to be run from the parent directory where you'd like to do the searching.

How to make a UILabel clickable?

Swift 5

Similar to @liorco, but need to replace @objc with @IBAction.

class DetailViewController: UIViewController {

    @IBOutlet weak var tripDetails: UILabel!

    override func viewDidLoad() {
        super.viewDidLoad()
        ...

        let tap = UITapGestureRecognizer(target: self, action: #selector(DetailViewController.tapFunction))
        tripDetails.isUserInteractionEnabled = true
        tripDetails.addGestureRecognizer(tap)
    }

    @IBAction func tapFunction(sender: UITapGestureRecognizer) {
        print("tap working")
    }
}

This is working on Xcode 10.2.

How do you configure HttpOnly cookies in tomcat / java webapps?

For cookies that I am explicitly setting, I switched to use SimpleCookie provided by Apache Shiro. It does not inherit from javax.servlet.http.Cookie so it takes a bit more juggling to get everything to work correctly however it does provide a property set HttpOnly and it works with Servlet 2.5.

For setting a cookie on a response, rather than doing response.addCookie(cookie) you need to do cookie.saveTo(request, response).

Numpy `ValueError: operands could not be broadcast together with shape ...`

If X and beta do not have the same shape as the second term in the rhs of your last line (i.e. nsample), then you will get this type of error. To add an array to a tuple of arrays, they all must be the same shape.

I would recommend looking at the numpy broadcasting rules.

Random number generator only generating one random number

Mark's solution can be quite expensive since it needs to synchronize everytime.

We can get around the need for synchronization by using the thread-specific storage pattern:


public class RandomNumber : IRandomNumber
{
    private static readonly Random Global = new Random();
    [ThreadStatic] private static Random _local;

    public int Next(int max)
    {
        var localBuffer = _local;
        if (localBuffer == null) 
        {
            int seed;
            lock(Global) seed = Global.Next();
            localBuffer = new Random(seed);
            _local = localBuffer;
        }
        return localBuffer.Next(max);
    }
}

Measure the two implementations and you should see a significant difference.

Open Redis port for remote connections

A quick note that if you are using AWS ec2 instance then there is one more extra step that I believe is also mandatory. I missed the step-3 and it took me whole day to figure out to add an inbound rule to security group

Step 1(as previous): in your redis.conf change bind 127.0.0.1 to bind 0.0.0.0

Step2(as previous): in your redis.conf change protected-mode yes to protected-mode no

important for Amazon Ec2 Instance:

Step3: In your current ec2 machine go to the security group. add an inbound rule for custom TCP with 6379 port and select option "use from anywhere".

How to navigate back to the last cursor position in Visual Studio Code?

With VSCode 1.43 (Q1 2020), those Alt+? / Alt+?, or Ctrl+- / Ctrl+Shift+- will also... preserve selection.

See issue 89699:

Benjamin Pasero (bpasero) adds:

going back/forward restores selections as they were.

Note that in order to get a history entry there needs to be at least 10 lines between the positions to consider the entry as new entry.

Go back/Forward selection -- https://user-images.githubusercontent.com/900690/73729489-6ca7da80-4735-11ea-9345-1228f0302110.gif

How to create a XML object from String in Java?

If you can create a string xml you can easily transform it to the xml document object e.g. -

String xmlString = "<?xml version=\"1.0\" encoding=\"utf-8\"?><a><b></b><c></c></a>";  

DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();  
DocumentBuilder builder;  
try {  
    builder = factory.newDocumentBuilder();  
    Document document = builder.parse(new InputSource(new StringReader(xmlString)));  
} catch (Exception e) {  
    e.printStackTrace();  
} 

You can use the document object and xml parsing libraries or xpath to get back the ip address.

How to make Toolbar transparent?

I know am late for the party. I've created a simple class to manage the Toolbar transparency.

import android.annotation.SuppressLint;
import android.graphics.drawable.ColorDrawable;
import android.support.v7.widget.Toolbar;



public class TransparentToolbarManager {

    private Toolbar mToolbar;
    private ColorDrawable colorDrawable;
    public static final int MAX_ALPHA = 255, MIN_ALPHA = 0;

    public TransparentToolbarManager(Toolbar mToolbar) {
        this.mToolbar = mToolbar;
        this.colorDrawable = new ColorDrawable(mToolbar.getContext().getResources().getColor(R.color.colorPrimary));
    }

    public TransparentToolbarManager(Toolbar mToolbar, ColorDrawable colorDrawable) {
        this.mToolbar = mToolbar;
        this.colorDrawable = colorDrawable;
    }

    //Fading toolbar
    public void manageFadingToolbar(int scrollDistance) {
        if (mToolbar != null && colorDrawable != null) {
            //FadeinAndOut according to the horizontal scrollValue
            if (scrollDistance <= MAX_ALPHA && scrollDistance >= MIN_ALPHA) {
                setToolbarAlpha(scrollDistance);
            } else if (scrollDistance > MAX_ALPHA) {
                setToolbarAlpha(MAX_ALPHA);
            }
        }
    }


    @SuppressLint("NewApi")
    public void setToolbarAlpha(int i) {
        colorDrawable.setAlpha(i);
        if (CommonHelper.isSupport(16)) {
            mToolbar.setBackground(colorDrawable);
        } else {
            mToolbar.setBackgroundDrawable(colorDrawable);
        }
    }


}

and the CommonHelper.isSupport()

public static boolean isSupport(int apiLevel) {
        return Build.VERSION.SDK_INT >= apiLevel;
}

Bulk load data conversion error (type mismatch or invalid character for the specified codepage) for row 1, column 4 (Year)

We use the bulk insert as well. The file we upload is sent from an external party. After a while of troubleshooting, I realized that their file had columns with commas in it. Just another thing to look for...

Getting the source of a specific image element with jQuery

To select and element where you know only the attribute value you can use the below jQuery script

var src = $('.conversation_img[alt="example"]').attr('src');

Please refer the jQuery Documentation for attribute equals selectors

Please also refer to the example in Demo

Following is the code incase you are not able to access the demo..

HTML

<div>
    <img alt="example" src="\images\show.jpg" />
    <img  alt="exampleAll" src="\images\showAll.jpg" />  

</div>

SCRIPT JQUERY

var src = $('img[alt="example"]').attr('src');
alert("source of image with alternate text = example - " + src);


var srcAll = $('img[alt="exampleAll"]').attr('src');
alert("source of image with alternate text = exampleAll - " + srcAll );

Output will be

Two Alert messages each having values

  1. source of image with alternate text = example - \images\show.jpg
  2. source of image with alternate text = exampleAll - \images\showAll.jpg

Android: Flush DNS

Perform a hard reboot of your phone. The easiest way to do this is to remove the phone's battery. Wait for at least 30 seconds, then replace the battery. The phone will reboot, and upon completing its restart will have an empty DNS cache.

Read more: How to Flush the DNS on an Android Phone | eHow.com http://www.ehow.com/how_10021288_flush-dns-android-phone.html#ixzz1gRJnmiJb

Python recursive folder read

I think the problem is that you're not processing the output of os.walk correctly.

Firstly, change:

filePath = rootdir + '/' + file

to:

filePath = root + '/' + file

rootdir is your fixed starting directory; root is a directory returned by os.walk.

Secondly, you don't need to indent your file processing loop, as it makes no sense to run this for each subdirectory. You'll get root set to each subdirectory. You don't need to process the subdirectories by hand unless you want to do something with the directories themselves.

How do I fix maven error The JAVA_HOME environment variable is not defined correctly?

  1. create folder Maven inside this folder extract download file

  2. this file should C:\Program Files\YourFolderName must in C:\Program Files drive

  3. goto This PC -> right click -> properties -> advanced system -> environment variable

  4. user variable ----> new & ** note create two variable ** if not may be give error i) variable name = MAVEN variable value = C:\Program Files\MAVEN

    ii) variable name = MAVEN_HOME variable value = C:\Program Files\MAVEN\apache-maven-3.6.3\apache-maven-3.6.3

  5. system variable path ---> Edit---> new----give path of this folder i) C:\Program Files\MAVEN
    ii) C:\Program Files\MAVEN\apache-maven-3.6.3\bin

Hurrraaaaayyyyy

How do you unit test private methods?

I use PrivateObject class. But as mentioned previously better to avoid testing private methods.

Class target = new Class();
PrivateObject obj = new PrivateObject(target);
var retVal = obj.Invoke("PrivateMethod");
Assert.AreEqual(retVal);

Error:(23, 17) Failed to resolve: junit:junit:4.12

Go to Go to "File" -> "Project Structure" -> "App" In the tab "properties". In "Library Repository" field put 'http://repo1.maven.org/maven2' then press Ok. It was fixed like that for me. Now the project is compiling.

load jquery after the page is fully loaded

Include your scripts at the bottom of the page before closing body tag.

More info HERE.

Convert array of JSON object strings to array of JS objects

If you have a JS array of JSON objects:

var s=['{"Select":"11","PhotoCount":"12"}','{"Select":"21","PhotoCount":"22"}'];

and you want an array of objects:

// JavaScript array of JavaScript objects
var objs = s.map(JSON.parse);

// ...or for older browsers
var objs=[];
for (var i=s.length;i--;) objs[i]=JSON.parse(s[i]);

// ...or for maximum speed:
var objs = JSON.parse('['+s.join(',')+']');

See the speed tests for browser comparisons.


If you have a single JSON string representing an array of objects:

var s='[{"Select":"11","PhotoCount":"12"},{"Select":"21","PhotoCount":"22"}]';

and you want an array of objects:

// JavaScript array of JavaScript objects
var objs = JSON.parse(s);

If you have an array of objects:

// A JavaScript array of JavaScript objects
var s = [{"Select":"11", "PhotoCount":"12"},{"Select":"21", "PhotoCount":"22"}];

…and you want JSON representation for it, then:

// JSON string representing an array of objects
var json = JSON.stringify(s);

…or if you want a JavaScript array of JSON strings, then:

// JavaScript array of strings (that are each a JSON object)
var jsons = s.map(JSON.stringify);

// ...or for older browsers
var jsons=[];
for (var i=s.length;i--;) jsons[i]=JSON.stringify(s[i]);

comparing two strings in ruby

Here are some:

"Ali".eql? "Ali"
=> true

The spaceship (<=>) method can be used to compare two strings in relation to their alphabetical ranking. The <=> method returns 0 if the strings are identical, -1 if the left hand string is less than the right hand string, and 1 if it is greater:

"Apples" <=> "Apples"
=> 0

"Apples" <=> "Pears"
=> -1

"Pears" <=> "Apples"
=> 1

A case insensitive comparison may be performed using the casecmp method which returns the same values as the <=> method described above:

"Apples".casecmp "apples"
=> 0

How to change the remote repository for a git submodule?

git config --file=.gitmodules -e opens the default editor in which you can update the path

Save Dataframe to csv directly to s3 Python

since you are using boto3.client(), try:

import boto3
from io import StringIO #python3 
s3 = boto3.client('s3', aws_access_key_id='key', aws_secret_access_key='secret_key')
def copy_to_s3(client, df, bucket, filepath):
    csv_buf = StringIO()
    df.to_csv(csv_buf, header=True, index=False)
    csv_buf.seek(0)
    client.put_object(Bucket=bucket, Body=csv_buf.getvalue(), Key=filepath)
    print(f'Copy {df.shape[0]} rows to S3 Bucket {bucket} at {filepath}, Done!')

copy_to_s3(client=s3, df=df_to_upload, bucket='abc', filepath='def/test.csv')

How to load local html file into UIWebView

I guess you need to allocate and init your webview first::

- (void)viewDidLoad
{
    NSString *htmlFile = [[NSBundle mainBundle] pathForResource:@"sample" ofType:@"html" inDirectory:@"html_files"];
    NSData *htmlData = [NSData dataWithContentsOfFile:htmlFile];
    webView = [[UIWebView alloc] init];
    [webView loadData:htmlData MIMEType:@"text/html" textEncodingName:@"UTF-8" baseURL:[NSURL URLWithString:@""]];

    [super viewDidLoad];
}

Check if an element is present in an array

Since ECMAScript6, one can use Set :

var myArray = ['A', 'B', 'C'];
var mySet = new Set(myArray);
var hasB = mySet.has('B'); // true
var hasZ = mySet.has('Z'); // false

Measuring the distance between two coordinates in PHP

Quite old question, but for those interested in a PHP code that returns the same results as Google Maps, the following does the job:

/**
 * Computes the distance between two coordinates.
 *
 * Implementation based on reverse engineering of
 * <code>google.maps.geometry.spherical.computeDistanceBetween()</code>.
 *
 * @param float $lat1 Latitude from the first point.
 * @param float $lng1 Longitude from the first point.
 * @param float $lat2 Latitude from the second point.
 * @param float $lng2 Longitude from the second point.
 * @param float $radius (optional) Radius in meters.
 *
 * @return float Distance in meters.
 */
function computeDistance($lat1, $lng1, $lat2, $lng2, $radius = 6378137)
{
    static $x = M_PI / 180;
    $lat1 *= $x; $lng1 *= $x;
    $lat2 *= $x; $lng2 *= $x;
    $distance = 2 * asin(sqrt(pow(sin(($lat1 - $lat2) / 2), 2) + cos($lat1) * cos($lat2) * pow(sin(($lng1 - $lng2) / 2), 2)));

    return $distance * $radius;
}

I've tested with various coordinates and it works perfectly.

I think it should be faster then some alternatives too. But didn't test that.

Hint: Google Maps uses 6378137 as Earth radius. So using it with other algorithms might work as well.

jQuery UI dialog box not positioned center screen

I was upgrading a legacy instance of jQuery UI and found that there was an extension to the dialog widget and it was simply using "center" instead of the position object. Implementing the position object or removing the parameter entirely worked for me (because center is the default).

How to insert DECIMAL into MySQL database

Yes, 4,2 means "4 digits total, 2 of which are after the decimal place". That translates to a number in the format of 00.00. Beyond that, you'll have to show us your SQL query. PHP won't translate 3.80 into 99.99 without good reason. Perhaps you've misaligned your fields/values in the query and are trying to insert a larger number that belongs in another field.

Using % for host when creating a MySQL user

If you want connect to user@'%' from localhost use mysql -h192.168.0.1 -uuser -p.

ASP.Net MVC: How to display a byte array image from model

I recommend something along these lines, even if the image lives inside of your model.

I realize you are asking for a direct way to access it right from the view and many others have answered that and told you what is wrong with that approach so this is just another way that will load the image in an async fashion for you and I think is a better approach.

Sample Model:

[Bind(Exclude = "ID")]
public class Item
{
    [Key]
    [ScaffoldColumn(false)]
    public int ID { get; set; }

    public String Name { get; set; }

    public byte[] InternalImage { get; set; } //Stored as byte array in the database.
}

Sample Method in the Controller:

public async Task<ActionResult> RenderImage(int id)
{
    Item item = await db.Items.FindAsync(id);

    byte[] photoBack = item.InternalImage;

    return File(photoBack, "image/png");
}

View

@model YourNameSpace.Models.Item

@{
    ViewBag.Title = "Details";
}

<h2>Details</h2>

<div>
<h4>Item</h4>
<hr />
<dl class="dl-horizontal">
    <img src="@Url.Action("RenderImage", new { id = Model.ID})" />
</dl>
<dl class="dl-horizontal">
    <dt>
        @Html.DisplayNameFor(model => model.Name)
    </dt>

    <dd>
        @Html.DisplayFor(model => model.Name)
    </dd>
</dl>
</div>

What's the best way to determine the location of the current PowerShell script?

I found that the older solutions posted here didn't work for me on PowerShell V5. I came up with this:

try {
    $scriptPath = $PSScriptRoot
    if (!$scriptPath)
    {
        if ($psISE)
        {
            $scriptPath = Split-Path -Parent -Path $psISE.CurrentFile.FullPath
        }
        else {
            Write-Host -ForegroundColor Red "Cannot resolve script file's path"
            exit 1
        }
    }
}
catch {
    Write-Host -ForegroundColor Red "Caught Exception: $($Error[0].Exception.Message)"
    exit 2
}

Write-Host "Path: $scriptPath"

What is the closest thing Windows has to fork()?

Prior to Microsoft introducing their new "Linux subsystem for Windows" option, CreateProcess() was the closest thing Windows has to fork(), but Windows requires you to specify an executable to run in that process.

The UNIX process creation is quite different to Windows. Its fork() call basically duplicates the current process almost in total, each in their own address space, and continues running them separately. While the processes themselves are different, they are still running the same program. See here for a good overview of the fork/exec model.

Going back the other way, the equivalent of the Windows CreateProcess() is the fork()/exec() pair of functions in UNIX.

If you were porting software to Windows and you don't mind a translation layer, Cygwin provided the capability that you want but it was rather kludgey.

Of course, with the new Linux subsystem, the closest thing Windows has to fork() is actually fork() :-)

ReactJS - How to use comments?

On the other hand, the following is a valid comment, pulled directly from a working application:

render () {
    return <DeleteResourceButton
            //confirm
            onDelete={this.onDelete.bind(this)}
            message="This file will be deleted from the server."
           />
}

Apparantly, when inside the angle brackets of a JSX element, the // syntax is valid, but the {/**/} is invalid. The following breaks:

render () {
    return <DeleteResourceButton
            {/*confirm*/}
            onDelete={this.onDelete.bind(this)}
            message="This file will be deleted from the server."
           />
}

How to convert string to integer in C#

If you are sure that you have "real" number in your string, or you are comfortable of any exception that might arise, use this.

string s="4";
int a=int.Parse(s);

For some more control over the process, use

string s="maybe 4";
int a;
if (int.TryParse(s, out a)) {
    // it's int;
}
else {
    // it's no int, and there's no exception;
}

How can I INSERT data into two tables simultaneously in SQL Server?

I was also struggling with this problem, and find that the best way is to use a CURSOR.

I have tried Denis solution with OUTPUT, but as he mentiond, it's impossible to output external columns in an insert statement, and the MERGE can't work when insert multiple rows by select.

So, i've used a CURSOR, for each row in the outer table, i've done a INSERT, then use the @@IDENTITY for another INSERT.

DECLARE @OuterID int

DECLARE MY_CURSOR CURSOR 
  LOCAL STATIC READ_ONLY FORWARD_ONLY
FOR 
SELECT  ID FROM   [external_Table]

OPEN MY_CURSOR
FETCH NEXT FROM MY_CURSOR INTO @OuterID

WHILE @@FETCH_STATUS = 0
BEGIN 
INSERT INTO [Table]   (data)
    SELECT data
    FROM     [external_Table] where ID = @OuterID 

    INSERT INTO [second_table] (FK,OuterID)
    VALUES(@OuterID,@@identity)

    FETCH NEXT FROM MY_CURSOR INTO @OuterID
END
CLOSE MY_CURSOR
DEALLOCATE MY_CURSOR

How to refresh a Page using react-route Link

Try like this.

You must give a function as value to onClick()

You button:

<button type="button" onClick={ refreshPage }> <span>Reload</span> </button> 

refreshPage function:

function refreshPage(){ 
    window.location.reload(); 
}

How can I find out what FOREIGN KEY constraint references a table in SQL Server?

Another way is to check the results of

sp_help 'TableName'

(or just highlight the quoted TableName and pres ALT+F1)

With time passing, I just decided to refine my answer. Below is a screenshot of the results that sp_help provides. A have used the AdventureWorksDW2012 DB for this example. There is numerous good information there, and what we are looking for is at the very end - highlighted in green:

enter image description here

Iterating through struct fieldnames in MATLAB

Since fields or fns are cell arrays, you have to index with curly brackets {} in order to access the contents of the cell, i.e. the string.

Note that instead of looping over a number, you can also loop over fields directly, making use of a neat Matlab features that lets you loop through any array. The iteration variable takes on the value of each column of the array.

teststruct = struct('a',3,'b',5,'c',9)

fields = fieldnames(teststruct)

for fn=fields'
  fn
  %# since fn is a 1-by-1 cell array, you still need to index into it, unfortunately
  teststruct.(fn{1})
end

SSL_connect: SSL_ERROR_SYSCALL in connection to github.com:443

I would suggest updating git. If you downloaded the .pkg then be sure to uninstall it first.

Grep characters before and after match?

3 characters before and 4 characters after

$> echo "some123_string_and_another" | grep -o -P '.{0,3}string.{0,4}'
23_string_and

Find closing HTML tag in Sublime Text

Under the "Goto" menu, Control + M is Jump to Matching Bracket. Works for parentheses as well.

Insert picture into Excel cell

Now we can add a picture to Excel directly and easely. Just follow these instructions:

  1. Go to the Insert tab.
  2. Click on the Pictures option (it’s in the illustrations group). image1
  3. In the ‘Insert Picture’ dialog box, locate the pictures that you want to insert into a cell in Excel. image2
  4. Click on the Insert button. image3
  5. Re-size the picture/image so that it can fit perfectly within the cell. image4
  6. Place the picture in the cell. A cool way to do this is to first press the ALT key and then move the picture with the mouse. It will snap and arrange itself with the border of the cell as soon it comes close to it.

If you have multiple images, you can select and insert all the images at once (as shown in step 4).

You can also resize images by selecting it and dragging the edges. In the case of logos or product images, you may want to keep the aspect ratio of the image intact. To keep the aspect ratio intact, use the corners of an image to resize it.


When you place an image within a cell using the steps above, it will not stick with the cell in case you resize, filter, or hide the cells. If you want the image to stick to the cell, you need to lock the image to the cell it’s placed n.

To do this, you need to follow the additional steps as shown below.

  1. Right-click on the picture and select Format Picture. image5
  2. In the Format Picture pane, select Size & Properties and with the options in Properties, select ‘Move and size with cells’. image6

Now you can move cells, filter it, or hide it, and the picture will also move/filter/hide.


NOTE:

This answer was taken from this link: Insert Picture into a Cell in Excel.

Correct way to use StringBuilder in SQL

When you already have all the "pieces" you wish to append, there is no point in using StringBuilder at all. Using StringBuilder and string concatenation in the same call as per your sample code is even worse.

This would be better:

return "select id1, " + " id2 " + " from " + " table";

In this case, the string concatenation is actually happening at compile-time anyway, so it's equivalent to the even-simpler:

return "select id1, id2 from table";

Using new StringBuilder().append("select id1, ").append(" id2 ")....toString() will actually hinder performance in this case, because it forces the concatenation to be performed at execution time, instead of at compile time. Oops.

If the real code is building a SQL query by including values in the query, then that's another separate issue, which is that you should be using parameterized queries, specifying the values in the parameters rather than in the SQL.

I have an article on String / StringBuffer which I wrote a while ago - before StringBuilder came along. The principles apply to StringBuilder in the same way though.

Initializing data.frames()

> df <- data.frame(matrix(ncol = 300, nrow = 100))
> dim(df)
[1] 100 300

Deciding between HttpClient and WebClient

HttpClient is the newer of the APIs and it has the benefits of

  • has a good async programming model
  • being worked on by Henrik F Nielson who is basically one of the inventors of HTTP, and he designed the API so it is easy for you to follow the HTTP standard, e.g. generating standards-compliant headers
  • is in the .Net framework 4.5, so it has some guaranteed level of support for the forseeable future
  • also has the xcopyable/portable-framework version of the library if you want to use it on other platforms - .Net 4.0, Windows Phone etc.

If you are writing a web service which is making REST calls to other web services, you should want to be using an async programming model for all your REST calls, so that you don't hit thread starvation. You probably also want to use the newest C# compiler which has async/await support.

Note: It isn't more performant AFAIK. It's probably somewhat similarly performant if you create a fair test.

How can I generate an apk that can run without server with react-native?

You should just use android studio for this process. It is just simpler. But first run this command in your react native app directory:

For Newer version of react-native(e.g. react native 0.49.0 & so on...)

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

For Older Version of react-native (0.49.0 & below)

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

Then Use android studio to open the 'android' folder in you react native app directory, it will ask to upgrade gradle and some other stuff. go to build-> Generate signed APK and follow the instructions from there. It's really straight forward.

C#: calling a button event handler method without actually clicking the button

All above methods are not good because you might change event function name. The easiest is:

btnTest.PerfromClick();

Error:Cause: unable to find valid certification path to requested target

Switching to the smartphone network & disabling the web security tool installed on my computer solved the problem.

Modifying the "Path to executable" of a windows service

It involves editing the registry, but service information can be found in HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services. Find the service you want to redirect, locate the ImagePath subkey and change that value.

Regex for parsing directory and filename

Try this:

^(.+)\/([^\/]+)$

EDIT: escaped the forward slash to prevent problems when copy/pasting the Regex

Linux Process States

When a process needs to fetch data from a disk, it effectively stops running on the CPU to let other processes run because the operation might take a long time to complete – at least 5ms seek time for a disk is common, and 5ms is 10 million CPU cycles, an eternity from the point of view of the program!

From the programmer point of view (also said "in userspace"), this is called a blocking system call. If you call write(2) (which is a thin libc wrapper around the system call of the same name), your process does not exactly stop at that boundary; it continues, in the kernel, running the system call code. Most of the time it goes all the way up to a specific disk controller driver (filename ? filesystem/VFS ? block device ? device driver), where a command to fetch a block on disk is submitted to the proper hardware, which is a very fast operation most of the time.

THEN the process is put in sleep state (in kernel space, blocking is called sleeping – nothing is ever 'blocked' from the kernel point of view). It will be awakened once the hardware has finally fetched the proper data, then the process will be marked as runnable and will be scheduled. Eventually, the scheduler will run the process.

Finally, in userspace, the blocking system call returns with proper status and data, and the program flow goes on.

It is possible to invoke most I/O system calls in non-blocking mode (see O_NONBLOCK in open(2) and fcntl(2)). In this case, the system calls return immediately and only report submitting the disk operation. The programmer will have to explicitly check at a later time whether the operation completed, successfully or not, and fetch its result (e.g., with select(2)). This is called asynchronous or event-based programming.

Most answers here mentioning the D state (which is called TASK_UNINTERRUPTIBLE in the Linux state names) are incorrect. The D state is a special sleep mode which is only triggered in a kernel space code path, when that code path can't be interrupted (because it would be too complex to program), with the expectation that it would block only for a very short time. I believe that most "D states" are actually invisible; they are very short lived and can't be observed by sampling tools such as 'top'.

You can encounter unkillable processes in the D state in a few situations. NFS is famous for that, and I've encountered it many times. I think there's a semantic clash between some VFS code paths, which assume to always reach local disks and fast error detection (on SATA, an error timeout would be around a few 100 ms), and NFS, which actually fetches data from the network which is more resilient and has slow recovery (a TCP timeout of 300 seconds is common). Read this article for the cool solution introduced in Linux 2.6.25 with the TASK_KILLABLE state. Before this era there was a hack where you could actually send signals to NFS process clients by sending a SIGKILL to the kernel thread rpciod, but forget about that ugly trick.…

toBe(true) vs toBeTruthy() vs toBeTrue()

As you read through the examples below, just keep in mind this difference

true === true // true
"string" === true // false
1 === true // false
{} === true // false

But

Boolean("string") === true // true
Boolean(1) === true // true
Boolean({}) === true // true

1. expect(statement).toBe(true)

Assertion passes when the statement passed to expect() evaluates to true

expect(true).toBe(true) // pass
expect("123" === "123").toBe(true) // pass

In all other cases cases it would fail

expect("string").toBe(true) // fail
expect(1).toBe(true); // fail
expect({}).toBe(true) // fail

Even though all of these statements would evaluate to true when doing Boolean():

So you can think of it as 'strict' comparison

2. expect(statement).toBeTrue()

This one does exactly the same type of comparison as .toBe(true), but was introduced in Jasmine recently in version 3.5.0 on Sep 20, 2019

3. expect(statement).toBeTruthy()

toBeTruthy on the other hand, evaluates the output of the statement into boolean first and then does comparison

expect(false).toBeTruthy() // fail
expect(null).toBeTruthy() // fail
expect(undefined).toBeTruthy() // fail
expect(NaN).toBeTruthy() // fail
expect("").toBeTruthy() // fail
expect(0).toBeTruthy() // fail

And IN ALL OTHER CASES it would pass, for example

expect("string").toBeTruthy() // pass
expect(1).toBeTruthy() // pass
expect({}).toBeTruthy() // pass

Applying a single font to an entire website with CSS

* { font-family: Algerian; }

The universal selector * refers to any element.

Calling Python in PHP

You can run a python script via php, and outputs on browser.

Basically you have to call the python script this way:

$command = "python /path/to/python_script.py 2>&1";
$pid = popen( $command,"r");
while( !feof( $pid ) )
{
 echo fread($pid, 256);
 flush();
 ob_flush();
 usleep(100000);
}
pclose($pid);

Note: if you run any time.sleep() in you python code, it will not outputs the results on browser.

For full codes working, visit How to execute python script from php and show output on browser

Can you call Directory.GetFiles() with multiple filters?

Just found an another way to do it. Still not one operation, but throwing it out to see what other people think about it.

private void getFiles(string path)
{
    foreach (string s in Array.FindAll(Directory.GetFiles(path, "*", SearchOption.AllDirectories), predicate_FileMatch))
    {
        Debug.Print(s);
    }
}

private bool predicate_FileMatch(string fileName)
{
    if (fileName.EndsWith(".mp3"))
        return true;
    if (fileName.EndsWith(".jpg"))
        return true;
    return false;
}

What is the size of ActionBar in pixels?

If you are using ActionBarSherlock, you can get the height with

@dimen/abs__action_bar_default_height

How to delete Project from Google Developers Console

As of this writing, it was necessary to:

  1. Select 'Manage all projects' from the dropdown list at the top of the Console page
  2. Click the delete button (trashcan icon) for the specific project on the project listing page

How to create multiple output paths in Webpack config

u can do lik

var config = {
    // TODO: Add common Configuration
    module: {},
};

var x= Object.assign({}, config, {
    name: "x",
    entry: "./public/x/js/x.js",
    output: {
       path: __dirname+"/public/x/jsbuild",
       filename: "xbundle.js"
    },
});
var y= Object.assign({}, config, {
    name: "y",
    entry: "./public/y/js/FBRscript.js",
    output: {
       path: __dirname+"/public/fbr/jsbuild",
       filename: "ybundle.js"
    },
});

let list=[x,y];

for(item of list){
    module.exports =item;
}

How to get cookie's expire time

Putting an encoded json inside the cookie is my favorite method, to get properly formated data out of a cookie. Try that:

$expiry = time() + 12345;
$data = (object) array( "value1" => "just for fun", "value2" => "i'll save whatever I want here" );
$cookieData = (object) array( "data" => $data, "expiry" => $expiry );
setcookie( "cookiename", json_encode( $cookieData ), $expiry );

then when you get your cookie next time:

$cookie = json_decode( $_COOKIE[ "cookiename" ] );

you can simply extract the expiry time, which was inserted as data inside the cookie itself..

$expiry = $cookie->expiry;

and additionally the data which will come out as a usable object :)

$data = $cookie->data;
$value1 = $cookie->data->value1;

etc. I find that to be a much neater way to use cookies, because you can nest as many small objects within other objects as you wish!

Is there a way to change the spacing between legend items in ggplot2?

A simple fix that I use to add space in horizontal legends, simply add spaces in the labels (see extract below):

  scale_fill_manual(values=c("red","blue","white"),
                    labels=c("Label of category 1          ",
                             "Label of category 2          ",
                             "Label of category 3"))

How to sum digits of an integer in java?

Java 8 Recursive Solution, If you dont want to use any streams.

UnaryOperator<Long> sumDigit = num -> num <= 0 ? 0 : num % 10 + this.sumDigit.apply(num/10);

How to use

Long sum = sumDigit.apply(123L);

Above solution will work for all positive number. If you want the sum of digits irrespective of positive or negative also then use the below solution.

UnaryOperator<Long> sumDigit = num -> num <= 0 ? 
         (num == 0 ? 0 : this.sumDigit.apply(-1 * num)) 
         : num % 10 + this.sumDigit.apply(num/10);

Execution failed for task :':app:mergeDebugResources'. Android Studio

In My case, I've written below code in build.gradle

android {
// ...
aaptOptions.cruncherEnabled = false
aaptOptions.useNewCruncher = false
// ...
}

It's work for me!...

Scroll / Jump to id without jQuery

below code might help you

var objControl=document.getElementById("divid");
objControl.scrollTop = objControl.offsetTop;

Searching multiple files for multiple words

If you are using Notepad++ editor (like the tag of the question suggests), you can use the great "Find in Files" functionality.

Go to Search > Find in Files (Ctrl+Shift+F for the keyboard addicted) and enter:

  • Find What = (test1|test2)
  • Filters = *.txt
  • Directory = enter the path of the directory you want to search in. You can check Follow current doc. to have the path of the current file to be filled.
  • Search mode = Regular Expression

writing a batch file that opens a chrome URL

@ECHO OFF
"c:\Program Files (x86)\Google\Chrome\Application\chrome.exe" --app="https://tweetdeck.twitter.com/"

@ECHO OFF
"c:\Program Files (x86)\Google\Chrome\Application\chrome.exe" --app="https://web.whatsapp.com/"

Convert JsonNode into POJO

This should do the trick:

mapper.readValue(fileReader, MyClass.class);

I say should because I'm using that with a String, not a BufferedReader but it should still work.

Here's my code:

String inputString = // I grab my string here
MySessionClass sessionObject;
try {
    ObjectMapper objectMapper = new ObjectMapper();
    sessionObject = objectMapper.readValue(inputString, MySessionClass.class);

Here's the official documentation for that call: http://jackson.codehaus.org/1.7.9/javadoc/org/codehaus/jackson/map/ObjectMapper.html#readValue(java.lang.String, java.lang.Class)

You can also define a custom deserializer when you instantiate the ObjectMapper: http://wiki.fasterxml.com/JacksonHowToCustomDeserializers

Edit: I just remembered something else. If your object coming in has more properties than the POJO has and you just want to ignore the extras you'll want to set this:

    objectMapper.configure(DeserializationConfig.Feature.FAIL_ON_UNKNOWN_PROPERTIES, false);

Or you'll get an error that it can't find the property to set into.

Avoid Adding duplicate elements to a List C#

You can use Enumerable.Except to get distinct items from lines3 which is not in lines2:

lines2.AddRange(lines3.Except(lines2));

If lines2 contains all items from lines3 then nothing will be added. BTW internally Except uses Set<string> to get distinct items from second sequence and to verify those items present in first sequence. So, it's pretty fast.

How to Display blob (.pdf) in an AngularJS app

First of all you need to set the responseType to arraybuffer. This is required if you want to create a blob of your data. See Sending_and_Receiving_Binary_Data. So your code will look like this:

$http.post('/postUrlHere',{myParams}, {responseType:'arraybuffer'})
  .success(function (response) {
       var file = new Blob([response], {type: 'application/pdf'});
       var fileURL = URL.createObjectURL(file);
});

The next part is, you need to use the $sce service to make angular trust your url. This can be done in this way:

$scope.content = $sce.trustAsResourceUrl(fileURL);

Do not forget to inject the $sce service.

If this is all done you can now embed your pdf:

<embed ng-src="{{content}}" style="width:200px;height:200px;"></embed>

Difference between .dll and .exe?

Two things: the extension and the header flag stored in the file.

Both files are PE files. Both contain the exact same layout. A DLL is a library and therefore can not be executed. If you try to run it you'll get an error about a missing entry point. An EXE is a program that can be executed. It has an entry point. A flag inside the PE header indicates which file type it is (irrelevant of file extension). The PE header has a field where the entry point for the program resides. In DLLs it isn't used (or at least not as an entry point).

One minor difference is that in most cases DLLs have an export section where symbols are exported. EXEs should never have an export section since they aren't libraries but nothing prevents that from happening. The Win32 loader doesn't care either way.

Other than that they are identical. So, in summary, EXEs are executable programs while DLLs are libraries loaded into a process and contain some sort of useful functionality like security, database access or something.

Close a MessageBox after several seconds

DMitryG's code "get the return value of the underlying MessageBox" has a bug so the timerResult is never actually correctly returned (MessageBox.Show call returns AFTER OnTimerElapsed completes). My fix is below:

public class TimedMessageBox {
    System.Threading.Timer _timeoutTimer;
    string _caption;
    DialogResult _result;
    DialogResult _timerResult;
    bool timedOut = false;

    TimedMessageBox(string text, string caption, int timeout, MessageBoxButtons buttons = MessageBoxButtons.OK, DialogResult timerResult = DialogResult.None)
    {
        _caption = caption;
        _timeoutTimer = new System.Threading.Timer(OnTimerElapsed,
            null, timeout, System.Threading.Timeout.Infinite);
        _timerResult = timerResult;
        using(_timeoutTimer)
            _result = MessageBox.Show(text, caption, buttons);
        if (timedOut) _result = _timerResult;
    }

    public static DialogResult Show(string text, string caption, int timeout, MessageBoxButtons buttons = MessageBoxButtons.OK, DialogResult timerResult = DialogResult.None) {
        return new TimedMessageBox(text, caption, timeout, buttons, timerResult)._result;
    }

    void OnTimerElapsed(object state) {
        IntPtr mbWnd = FindWindow("#32770", _caption); // lpClassName is #32770 for MessageBox
        if(mbWnd != IntPtr.Zero)
            SendMessage(mbWnd, WM_CLOSE, IntPtr.Zero, IntPtr.Zero);
        _timeoutTimer.Dispose();
        timedOut = true;
    }

    const int WM_CLOSE = 0x0010;
    [System.Runtime.InteropServices.DllImport("user32.dll", SetLastError = true, CharSet = System.Runtime.InteropServices.CharSet.Auto)]
    static extern IntPtr FindWindow(string lpClassName, string lpWindowName);
    [System.Runtime.InteropServices.DllImport("user32.dll", CharSet = System.Runtime.InteropServices.CharSet.Auto)]
    static extern IntPtr SendMessage(IntPtr hWnd, UInt32 Msg, IntPtr wParam, IntPtr lParam);
}

How to create a oracle sql script spool file

To spool from a BEGIN END block is pretty simple. For example if you need to spool result from two tables into a file, then just use the for loop. Sample code is given below.

BEGIN

FOR x IN 
(
    SELECT COLUMN1,COLUMN2 FROM TABLE1
    UNION ALL
    SELECT COLUMN1,COLUMN2 FROM TABLEB
)    
LOOP
    dbms_output.put_line(x.COLUMN1 || '|' || x.COLUMN2);
END LOOP;

END;
/

How can I copy a file on Unix using C?

Copying files byte-by-byte does work, but is slow and wasteful on modern UNIXes. Modern UNIXes have “copy-on-write” support built-in to the filesystem: a system call makes a new directory entry pointing at the existing bytes on disk, and no file content bytes on disk are touched until one of the copies is modified, at which point only the changed blocks are written to disk. This allows near-instant file copies that use no additional file blocks, regardless of file size. For example, here are some details about how this works in xfs.

On linux, use the FICLONE ioctl as coreutils cp now does by default.

 #ifdef FICLONE
   return ioctl (dest_fd, FICLONE, src_fd);
 #else
   errno = ENOTSUP;
   return -1;
 #endif

On macOS, use clonefile(2) for instant copies on APFS volumes. This is what Apple’s cp -c uses. The docs are not completely clear but it is likely that copyfile(3) with COPYFILE_CLONE also uses this. Leave a comment if you’d like me to test that.

In case these copy-on-write operations are not supported—whether the OS is too old, the underlying file system does not support it, or because you are copying files between different filesystems—you do need to fall back to trying sendfile, or as a last resort, copying byte-by-byte. But to save everyone a lot of time and disk space, please give FICLONE and clonefile(2) a try first.

Convert Int to String in Swift

exampleLabel.text = String(yourInt)

How to get first N number of elements from an array

With lodash, take function, you can achieve this by following:

_.take([1, 2, 3]);
// => [1]
 
_.take([1, 2, 3], 2);
// => [1, 2]
 
_.take([1, 2, 3], 5);
// => [1, 2, 3]
 
_.take([1, 2, 3], 0);
// => []

jquery: get id from class selector

As of jQuery 1.6, you could (and some would say should) use .prop instead of .attr

$('.test').click(function(){
    alert($(this).prop('id'));
});

It is discussed further in this post: .prop() vs .attr()

SQL Server: Null VS Empty String

Be careful with nulls and checking for inequality in sql server.

For example

select * from foo where bla <> 'something' 

will NOT return records where bla is null. Even though logically it should.

So the right way to check would be

select * from foo where isnull(bla,'') <> 'something' 

Which of course people often forget and then get weird bugs.

Including a groovy script in another groovy

evaluate(new File("../tools/Tools.groovy"))

Put that at the top of your script. That will bring in the contents of a groovy file (just replace the file name between the double quotes with your groovy script).

I do this with a class surprisingly called "Tools.groovy".

Angular expression if array contains

You can accomplish this with a slightly different syntax:

ng-class="{'approved': selectedForApproval.indexOf(jobSet) === -1}"

Plnkr

Delete specific line number(s) from a text file using sed?

If you want to delete lines 5 through 10 and 12:

sed -e '5,10d;12d' file

This will print the results to the screen. If you want to save the results to the same file:

sed -i.bak -e '5,10d;12d' file

This will back the file up to file.bak, and delete the given lines.

Note: Line numbers start at 1. The first line of the file is 1, not 0.

What do hjust and vjust do when making a plot using ggplot?

The value of hjust and vjust are only defined between 0 and 1:

  • 0 means left-justified
  • 1 means right-justified

Source: ggplot2, Hadley Wickham, page 196

(Yes, I know that in most cases you can use it beyond this range, but don't expect it to behave in any specific way. This is outside spec.)

hjust controls horizontal justification and vjust controls vertical justification.

An example should make this clear:

td <- expand.grid(
    hjust=c(0, 0.5, 1),
    vjust=c(0, 0.5, 1),
    angle=c(0, 45, 90),
    text="text"
)

ggplot(td, aes(x=hjust, y=vjust)) + 
    geom_point() +
    geom_text(aes(label=text, angle=angle, hjust=hjust, vjust=vjust)) + 
    facet_grid(~angle) +
    scale_x_continuous(breaks=c(0, 0.5, 1), expand=c(0, 0.2)) +
    scale_y_continuous(breaks=c(0, 0.5, 1), expand=c(0, 0.2))

enter image description here


To understand what happens when you change the hjust in axis text, you need to understand that the horizontal alignment for axis text is defined in relation not to the x-axis, but to the entire plot (where this includes the y-axis text). (This is, in my view, unfortunate. It would be much more useful to have the alignment relative to the axis.)

DF <- data.frame(x=LETTERS[1:3],y=1:3)
p <- ggplot(DF, aes(x,y)) + geom_point() + 
    ylab("Very long label for y") +
    theme(axis.title.y=element_text(angle=0))


p1 <- p + theme(axis.title.x=element_text(hjust=0)) + xlab("X-axis at hjust=0")
p2 <- p + theme(axis.title.x=element_text(hjust=0.5)) + xlab("X-axis at hjust=0.5")
p3 <- p + theme(axis.title.x=element_text(hjust=1)) + xlab("X-axis at hjust=1")

library(ggExtra)
align.plots(p1, p2, p3)

enter image description here


To explore what happens with vjust aligment of axis labels:

DF <- data.frame(x=c("a\na","b","cdefghijk","l"),y=1:4)
p <- ggplot(DF, aes(x,y)) + geom_point()

p1 <- p + theme(axis.text.x=element_text(vjust=0, colour="red")) + 
        xlab("X-axis labels aligned with vjust=0")
p2 <- p + theme(axis.text.x=element_text(vjust=0.5, colour="red")) + 
        xlab("X-axis labels aligned with vjust=0.5")
p3 <- p + theme(axis.text.x=element_text(vjust=1, colour="red")) + 
        xlab("X-axis labels aligned with vjust=1")


library(ggExtra)
align.plots(p1, p2, p3)

enter image description here

Why use def main()?

Without the main sentinel, the code would be executed even if the script were imported as a module.

How (and why) to use display: table-cell (CSS)

How (and why) to use display: table-cell (CSS)

I just wanted to mention, since I don't think any of the other answers did directly, that the answer to "why" is: there is no good reason, and you should probably never do this.

In my over a decade of experience in web development, I can't think of a single time I would have been better served to have a bunch of <div>s with display styles than to just have table elements.

The only hypothetical I could come up with is if you have tabular data stored in some sort of non-HTML-table format (eg. a CSV file). In a very specific version of this case it might be easier to just add <div> tags around everything and then add descendent-based styles, instead of adding actual table tags.

But that's an extremely contrived example, and in all real cases I know of simply using table tags would be better.

Why has it failed to load main-class manifest attribute from a JAR file?

  1. set the classpath and compile

    javac -classpath "C:\Program Files\Java\jdk1.6.0_updateVersion\tools.jar" yourApp.java

  2. create manifest.txt

    Main-Class: yourApp newline

  3. create yourApp.jar

    jar cvf0m yourApp.jar manifest.txt yourApp.class

  4. run yourApp.jar

    java -jar yourApp.jar

Date / Timestamp to record when a record was added to the table?

You can make a default constraint on this column that will put a default getdate() as a value.

Example:

alter table dbo.TABLE 
add constraint df_TABLE_DATE default getdate() for DATE_COLUMN

Better way to sum a property value in an array

I always avoid changing prototype method and adding library so this is my solution:

Using reduce Array prototype method is sufficient

// + operator for casting to Number
items.reduce((a, b) => +a + +b.price, 0);

Add a column to a table, if it does not already exist

Another alternative. I prefer this approach because it is less writing but the two accomplish the same thing.

IF COLUMNPROPERTY(OBJECT_ID('dbo.Person'), 'ColumnName', 'ColumnId') IS NULL
BEGIN
    ALTER TABLE Person 
    ADD ColumnName VARCHAR(MAX) NOT NULL
END

I also noticed yours is looking for where table does exist that is obviously just this

 if COLUMNPROPERTY( OBJECT_ID('dbo.Person'),'ColumnName','ColumnId') is not null

How to play only the audio of a Youtube video using HTML 5?

I agree with Tom van der Woerdt. You could use CSS to hide the video (visibility:hidden or overflow:hidden in a div wrapper constrained by height), but that may violate Youtube's policies. Additionally, how could you control the audio (pause, stop, volume, etc.)?

You could instead turn to resources such as http://www.houndbite.com/ to manage audio.

jQuery: Test if checkbox is NOT checked

I know this has already been answered, but still, this is a good way to do it:

if ($("#checkbox").is(":checked")==false) {
    //Do stuff here like: $(".span").html("<span>Lorem</span>");
}

How to rearrange Pandas column sequence?

I would suggest you just write a function to do what you're saying probably using drop (to delete columns) and insert to insert columns at a position. There isn't an existing API function to do what you're describing.

Artificially create a connection timeout error

If you want to use an active connection you can also use http://httpbin.org/delay/#, where # is the time you want their server to wait before sending a response. As long as your timeout is shorter than the delay ... should simulate the effect. I've successfully used it with the python requests package.

You may want to modify your request if you're sending anything sensitive - no idea what happens to the data sent to them.

Set cellpadding and cellspacing in CSS?

Setting margins on table cells doesn't really have any effect as far as I know. The true CSS equivalent for cellspacing is border-spacing - but it doesn't work in Internet Explorer.

You can use border-collapse: collapse to reliably set cell spacing to 0 as mentioned, but for any other value I think the only cross-browser way is to keep using the cellspacing attribute.

Transform hexadecimal information to binary using a Linux command

As @user786653 suggested, use the xxd(1) program:

xxd -r -p input.txt output.bin

How do I use Wget to download all images into a single folder, from a URL?

wget utility retrieves files from World Wide Web (WWW) using widely used protocols like HTTP, HTTPS and FTP. Wget utility is freely available package and license is under GNU GPL License. This utility can be install any Unix-like Operating system including Windows and MAC OS. It’s a non-interactive command line tool. Main feature of Wget is it’s robustness. It’s designed in such way so that it works in slow or unstable network connections. Wget automatically start download where it was left off in case of network problem. Also downloads file recursively. It’ll keep trying until file has be retrieved completely.

Install wget in linux machine sudo apt-get install wget

Create a folder where you want to download files . sudo mkdir myimages cd myimages

Right click on the webpage and for example if you want image location right click on image and copy image location. If there are multiple images then follow the below:

If there are 20 images to download from web all at once, range starts from 0 to 19.

wget http://joindiaspora.com/img{0..19}.jpg

How can I give access to a private GitHub repository?

Two steps:
1. Login and click "Invite someone" in the right column under "People". Enter and select persons github id.
2. It will then give you the option to "Invite Username to some teams" at which point you simply check off which teams you want to add them to then click "Send Invitation"

Alternatively:
1. Get the persons github id (not their email)
2. Navigate to the repository you would like to add the user to
3. Click "Settings" in the right column (not the gearbox settings along the top)
4. Click Collaborators long the left column
5. Select the repository name
6. Where it reads "Invite or add users to team" add the persons github id
7. An invitation will then be e-mailed.

Please let me know how this worked for you!

ASP.NET: HTTP Error 500.19 – Internal Server Error 0x8007000d

Problem solved. Here are the steps that I tried:

  • Enable the 32-bit application in IIS -> Application pool -> Advanced settings
  • Copy System.EnterpriseServices.dll and System.EnterpriseServices.Wrapper.dll from C:\Windows\Microsoft.NET\Framework\v2.0.50727 to the application bin folder
  • Do comments/uncomments to sections on the web.config and found that problem related to the referenced DLL.

The config that I commented the previous one that I added:

<section name="handlers" overrideModeDefault="Allow" /> 
<section name="modules" allowDefinition="MachineToApplication" overrideModeDefault="Allow"/>
  • Add the required FasterFlect.DLL used by Combres.DLL v2.1.0.0 to the application bin folder (shall download the full zip from Combres codeplex, because the required fasterflect DLL V2.0.3732.24338 cannot be found in fasterflect codeplex) and other DLLs. For convinience, use the full Combres.DLL (1,3MB)
  • Check that the DLL versions and public key tokens are configured correctly in web.config using tool, e.g. .NET Reflector

TSQL select into Temp table from dynamic sql

DECLARE @count_ser_temp int;
DECLARE @TableName AS VARCHAR(100)
SELECT @TableName = 'TableTemporal'

EXECUTE ('CREATE VIEW vTemp AS
    SELECT *
    FROM ' + @TableTemporal)
SELECT TOP 1 * INTO #servicios_temp  FROM vTemp

DROP VIEW vTemp

-- Contar la cantidad de registros de la tabla temporal
SELECT @count_ser_temp = COUNT(*) FROM #servicios_temp;

-- Recorro los registros de la tabla temporal 
WHILE @count_ser_temp > 0
 BEGIN
 END
END

How merge two objects array in angularjs?

You can use angular.extend(dest, src1, src2,...);

In your case it would be :

angular.extend($scope.actions.data, data);

See documentation here :

https://docs.angularjs.org/api/ng/function/angular.extend

Otherwise, if you only get new values from the server, you can do the following

for (var i=0; i<data.length; i++){
    $scope.actions.data.push(data[i]);
}

Aggregate function in SQL WHERE-Clause

UPDATED query:

select id from t where id < (select max(id) from t);

It'll select all but the last row from the table t.

How to create Android Facebook Key Hash?

Here is what you need to do -

Download openSSl from Code Extract it. create a folder- OpenSSL in C:/ and copy the extracted code here.

detect debug.keystore file path. If u didn't find, then do a search in C:/ and use the Path in the command in next step.

detect your keytool.exe path and go to that dir/ in command prompt and run this command in 1 line-

$ keytool -exportcert -alias androiddebugkey -keystore "C:\Documents and Settings\Administrator.android\debug.keystore" | "C:\OpenSSL\bin\openssl" sha1 -binary |"C:\OpenSSL\bin\openssl" base64

it will ask for password, put android that's all. u will get a key-hash

How do I test if a recordSet is empty? isNull?

If Not temp_rst1 Is Nothing Then ...

How to create a stacked bar chart for my DataFrame using seaborn?

You could use pandas plot as @Bharath suggest:

import seaborn as sns
sns.set()
df.set_index('App').T.plot(kind='bar', stacked=True)

Output:

enter image description here

Updated:

from matplotlib.colors import ListedColormap df.set_index('App')\ .reindex_axis(df.set_index('App').sum().sort_values().index, axis=1)\ .T.plot(kind='bar', stacked=True, colormap=ListedColormap(sns.color_palette("GnBu", 10)), figsize=(12,6))

Updated Pandas 0.21.0+ reindex_axis is deprecated, use reindex

from matplotlib.colors import ListedColormap

df.set_index('App')\
  .reindex(df.set_index('App').sum().sort_values().index, axis=1)\
  .T.plot(kind='bar', stacked=True,
          colormap=ListedColormap(sns.color_palette("GnBu", 10)), 
          figsize=(12,6))

Output:

enter image description here

How to format date in angularjs

{{convertToDate  | date :  dateformat}}                                             
$rootScope.dateFormat = 'MM/dd/yyyy';

What is boilerplate code?

Boilerplate code means a piece of code which can be used over and over again. On the other hand, anyone can say that it's a piece of reusable code.

The term actually came from the steel industries.

For a little bit of history, according to Wikipedia:

In the 1890s, boilerplate was actually cast or stamped in metal ready for the printing press and distributed to newspapers around the United States. Until the 1950s, thousands of newspapers received and used this kind of boilerplate from the nation's largest supplier, the Western Newspaper Union. Some companies also sent out press releases as boilerplate so that they had to be printed as written.

Now according to Wikipedia:

In object-oriented programs, classes are often provided with methods for getting and setting instance variables. The definitions of these methods can frequently be regarded as boilerplate. Although the code will vary from one class to another, it is sufficiently stereotypical in structure that it would be better generated automatically than written by hand. For example, in the following Java class representing a pet, almost all the code is boilerplate except for the declarations of Pet, name and owner:

public class Pet {
    private PetName name;
    private Person owner;

    public Pet(PetName name, Person owner) {
        this.name = name;
        this.owner = owner;
    }

    public PetName getName() {
        return name;
    }

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

    public Person getOwner() {
        return owner;
    }

    public void setOwner(Person owner) {
        this.owner = owner;
    }
}

JQuery .on() method with multiple event handlers to one selector

Also, if you had multiple event handlers attached to the same selector executing the same function, you could use

$('table.planning_grid').on('mouseenter mouseleave', function() {
    //JS Code
});

Timestamp conversion in Oracle for YYYY-MM-DD HH:MM:SS format

Use TO_TIMESTAMP function

TO_TIMESTAMP(date_string,'YYYY-MM-DD HH24:MI:SS')

saving a file (from stream) to disk using c#

I have to quote Jon (the master of c#) Skeet:

Well, the easiest way would be to open a file stream and then use:

byte[] data = memoryStream.ToArray(); fileStream.Write(data, 0, data.Length);

That's relatively inefficient though, as it involves copying the buffer. It's fine for small streams, but for huge amounts of data you should consider using:

fileStream.Write(memoryStream.GetBuffer(), 0, memoryStream.Position);

What are these ^M's that keep showing up in my files in emacs?

In git-config, set core.autocrlf to true to make git automatically convert line endings correctly for your platform, e.g. run this command for a global setting:

git config --global core.autocrlf true

Easy way to password-protect php page

A simple way to protect a file with no requirement for a separate login page - just add this to the top of the page:

Change secretuser and secretpassword to your user/password.

$user = $_POST['user'];
$pass = $_POST['pass'];

if(!($user == "secretuser" && $pass == "secretpassword"))
{
    echo '<html><body><form method="POST" action="'.$_SERVER['REQUEST_URI'].'">
            Username: <input type="text" name="user"></input><br/>
            Password: <input type="password" name="pass"></input><br/>
            <input type="submit" name="submit" value="Login"></input>
            </form></body></html>';
    exit();
}

Way to get all alphabetic chars in an array in PHP?

<?php 

$array = Array();
for( $i = 65; $i < 91; $i++){
        $array[] = chr($i);
}

foreach( $array as $k => $v){
        echo "$k $v \n";
}

?>

$ php loop.php 
0 A 
1 B 
2 C 
3 D 
4 E 
5 F 
6 G 
7 H
...

ENOENT, no such file or directory

Another possibility is that you are missing an .npmrc file if you are pulling any packages that are not publicly available.

You will need to add an .npmrc file at the root directory and add the private/internal registry inside of the .npmrc file like this:

registry=http://private.package.source/secret/npm-packages/

How to change color of Android ListView separator line?

Use android:divider="#FF0000" and android:dividerHeight="2px" for ListView.

<ListView 
android:id="@android:id/list"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:divider="#0099FF"
android:dividerHeight="2px"/>

How can I create a dropdown menu from a List in Tkinter?

To create a "drop down menu" you can use OptionMenu in tkinter

Example of a basic OptionMenu:

from Tkinter import *

master = Tk()

variable = StringVar(master)
variable.set("one") # default value

w = OptionMenu(master, variable, "one", "two", "three")
w.pack()

mainloop()

More information (including the script above) can be found here.


Creating an OptionMenu of the months from a list would be as simple as:

from tkinter import *

OPTIONS = [
"Jan",
"Feb",
"Mar"
] #etc

master = Tk()

variable = StringVar(master)
variable.set(OPTIONS[0]) # default value

w = OptionMenu(master, variable, *OPTIONS)
w.pack()

mainloop()

In order to retrieve the value the user has selected you can simply use a .get() on the variable that we assigned to the widget, in the below case this is variable:

from tkinter import *

OPTIONS = [
"Jan",
"Feb",
"Mar"
] #etc

master = Tk()

variable = StringVar(master)
variable.set(OPTIONS[0]) # default value

w = OptionMenu(master, variable, *OPTIONS)
w.pack()

def ok():
    print ("value is:" + variable.get())

button = Button(master, text="OK", command=ok)
button.pack()

mainloop()

I would highly recommend reading through this site for further basic tkinter information as the above examples are modified from that site.

How do you simulate Mouse Click in C#?

I have tried the code that Marcos posted and it didn't worked for me. Whatever i was given to the Y coordinate the cursor didn't moved on Y axis. The code below will work if you want the position of the cursor relative to the left-up corner of your desktop, not relative to your application.

    [DllImport("user32.dll", CharSet = CharSet.Auto, CallingConvention = CallingConvention.StdCall)]
    public static extern void mouse_event(long dwFlags, long dx, long dy, long cButtons, long dwExtraInfo);
    private const int MOUSEEVENTF_LEFTDOWN = 0x02;
    private const int MOUSEEVENTF_LEFTUP = 0x04;
    private const int MOUSEEVENTF_MOVE = 0x0001;

    public void DoMouseClick()
    {
        X = Cursor.Position.X;
        Y = Cursor.Position.Y;

        //move to coordinates
        pt = (Point)pc.ConvertFromString(X + "," + Y);
        Cursor.Position = pt;       

        //perform click            
        mouse_event(MOUSEEVENTF_LEFTDOWN, 0, 0, 0, 0);
        mouse_event(MOUSEEVENTF_LEFTUP, 0, 0, 0, 0);
    }

I only use mouse_event function to actually perform the click. You can give X and Y what coordinates you want, i used values from textbox:

            X = Convert.ToInt32(tbX.Text);
            Y = Convert.ToInt32(tbY.Text);

Facebook login "given URL not allowed by application configuration"

Also check to see if you are missing the www in the url which was on my case

i was testing on http://www.mywebsite.com and in the facebook app i had set http://mywebsite.com

How to make an ImageView with rounded corners?

Kotlin Version:

@GlideExtension
object GamersGeekGlideExtension {

    @NonNull
    @JvmStatic
    @GlideOption
    fun roundedCorners(options: BaseRequestOptions<*>, context: Context, cornerRadius: Int): BaseRequestOptions<*> {
        val px =
            (cornerRadius * (context.resources.displayMetrics.xdpi / DisplayMetrics.DENSITY_DEFAULT)).roundToInt()
        return options.transforms(RoundedCorners(px))
    }
}

Note: Glide Extensions now requires BaseRequestOptions instead of RequestOptions. Also, its the same function as @Sir Codesalot answer just converted in kotlin. Happy Coding.

How to split comma separated string using JavaScript?

Use

YourCommaSeparatedString.split(',');

How do I convert csv file to rdd

Here is another example using Spark/Scala to convert a CSV to RDD. For a more detailed description see this post.

def main(args: Array[String]): Unit = {
  val csv = sc.textFile("/path/to/your/file.csv")

  // split / clean data
  val headerAndRows = csv.map(line => line.split(",").map(_.trim))
  // get header
  val header = headerAndRows.first
  // filter out header (eh. just check if the first val matches the first header name)
  val data = headerAndRows.filter(_(0) != header(0))
  // splits to map (header/value pairs)
  val maps = data.map(splits => header.zip(splits).toMap)
  // filter out the user "me"
  val result = maps.filter(map => map("user") != "me")
  // print result
  result.foreach(println)
}

A process crashed in windows .. Crash dump location

a core dump is usually only made when the Windows kernel crashes (aka blue screen). A servicecrash will most of the times only leave some logging behind (in the event viewer probably).

If it is the bluescreen crash dump you are looking for, look in C:\Windows\Minidump or C:\windows\MEMORY.DMP

What is "runtime"?

Runtime is a general term that refers to any library, framework, or platform that your code runs on.

The C and C++ runtimes are collections of functions.

The .NET runtime contains an intermediate language interpreter, a garbage collector, and more.

Git merge errors

git commit -m "Merged master fixed conflict."

Run an Ansible task only when the variable contains a specific string

None of the above answers worked for me in ansible 2.3.0.0, but the following does:

when: variable1 | search("value")

In ansible 2.9 this is deprecated in favor of using ~ concatenation for variable replacement:

when: "variable1.find('v=' ~ value) == -1"

http://jinja.pocoo.org/docs/dev/templates/#other-operators

Other options:

when: "inventory_hostname in groups[sync_source]"

How to clear Flutter's Build cache?

Or you can delete the /build folder under your /app-project folder manually if you cannot run flutter command.

Normalization in DOM parsing with java - how does it work?

The rest of the sentence is:

where only structure (e.g., elements, comments, processing instructions, CDATA sections, and entity references) separates Text nodes, i.e., there are neither adjacent Text nodes nor empty Text nodes.

This basically means that the following XML element

<foo>hello 
wor
ld</foo>

could be represented like this in a denormalized node:

Element foo
    Text node: ""
    Text node: "Hello "
    Text node: "wor"
    Text node: "ld"

When normalized, the node will look like this

Element foo
    Text node: "Hello world"

And the same goes for attributes: <foo bar="Hello world"/>, comments, etc.

jQuery - how to write 'if not equal to' (opposite of ==)

!=

For example,

if ("apple" != "orange")
  // true, the string "apple" is not equal to the string "orange"

Means not. See also the logical operators list. Also, when you see triple characters, it's a type sensitive comparison. (e.g. if (1 === '1') [not equal])

How to select first child with jQuery?

Try with: $('.onediv').eq(0)

demo jsBin

From the demo: Other examples of selectors and methods targeting the first LI unside an UL:

.eq() Method: $('li').eq(0)
:eq() selector: $('li:eq(0)')
.first() Method $('li').first()
:first selector: $('li:first')
:first-child selector: $('li:first-child')
:lt() selector:$('li:lt(1)')
:nth-child() selector:$('li:nth-child(1)')

jQ + JS:

Array.slice() Method: $('li').slice(0,1)

you can also use [i] to get the JS HTMLelement index out of the jQuery el. (array) collection like eg:

$('li')[0]

now that you have the JS element representation you have to use JS native methods eg:

$('li')[0].className = 'active'; // Adds class "active" to the first LI in the DOM

or you can (don't - it's bad design) wrap it back into a jQuery object

$( $('li')[0] ).addClass('active'); // Don't. Use .eq() instead

How can I change the Y-axis figures into percentages in a barplot?

In principle, you can pass any reformatting function to the labels parameter:

+ scale_y_continuous(labels = function(x) paste0(x*100, "%")) # Multiply by 100 & add %  

Or

+ scale_y_continuous(labels = function(x) paste0(x, "%")) # Add percent sign 

Reproducible example:

library(ggplot2)
df = data.frame(x=seq(0,1,0.1), y=seq(0,1,0.1))

ggplot(df, aes(x,y)) + 
  geom_point() +
  scale_y_continuous(labels = function(x) paste0(x*100, "%"))

HowTo Generate List of SQL Server Jobs and their owners

If you don't have access to sysjobs table (someone elses server etc) you might be have or be allowed access to sysjobs_view

SELECT *
 from  msdb..sysjobs_view s 
 left join master.sys.syslogins l on s.owner_sid = l.sid

or

SELECT *, SUSER_SNAME(s.owner_sid) AS owner
 from  msdb..sysjobs_view s 

Limiting the number of characters per line with CSS

If you use CSS to select a monospace font, the problem of varying character length is easily solved.

C++ compile time error: expected identifier before numeric constant

You cannot do this:

vector<string> name(5); //error in these 2 lines
vector<int> val(5,0);

in a class outside of a method.

You can initialize the data members at the point of declaration, but not with () brackets:

class Foo {
    vector<string> name = vector<string>(5);
    vector<int> val{vector<int>(5,0)};
};

Before C++11, you need to declare them first, then initialize them e.g in a contructor

class Foo {
    vector<string> name;
    vector<int> val;
 public:
  Foo() : name(5), val(5,0) {}
};

Docker: adding a file from a parent directory

If you are using skaffold, use 'context:' to specify context location for each image dockerfile - context: ../../../

            apiVersion: skaffold/v2beta4
            kind: Config
            metadata:
                name: frontend
            build:
                artifacts:
                    - image: nginx-angular-ui
                      context: ../../../
                      sync:
                          # A local build will update dist and sync it to the container
                          manual:
                              - src: './dist/apps'
                                dest: '/usr/share/nginx/html'
                      docker:
                          dockerfile: ./tools/pipelines/dockerfile/nginx.dev.dockerfile
                    - image: webapi/image
                      context: ../../../../api/
                      docker:
                          dockerfile: ./dockerfile
            deploy:
                kubectl:
                    manifests:
                        - ./.k8s/*.yml

skaffold run -f ./skaffold.yaml

Create a HTML table where each TR is a FORM

You may have issues with column width, but you can set those explicitly.

<table>
  <tr>
    <td>
       <form>
         <table>
           <tr>
             <td></td> 
             <td></td> 
             <td></td> 
             <td></td> 
             <td></td> 
             <td></td> 
           </tr>
         </table>
       </form>
     </td>
    </tr>
  <tr>
    <td>
       <form>
         <table>
           <tr>
             <td></td> 
             <td></td> 
             <td></td> 
             <td></td> 
             <td></td> 
             <td></td> 
           </tr>
         </table>
       </form>
     </td>
    </tr>
  </table>

You may want to also consider making it a single form, and then using jQuery to select the form elements from the row you want, serialize them, and submit them as the form.

See: http://api.jquery.com/serialize/

Also, there are a number of very nice grid plugins: http://www.google.com/search?q=jquery+grid&ie=utf-8&oe=utf-8&aq=t&rls=org.mozilla:en-US:official&client=firefox-a

Select multiple columns using Entity Framework

Why don't you create a new object right in the .Select:

.Select(x => new PInfo{ 
    ServerName = x.ServerName, 
    ProcessID = x.ProcessID, 
    UserName = x.Username }).ToList();

in_array multiple values

IMHO Mark Elliot's solution's best one for this problem. If you need to make more complex comparison operations between array elements AND you're on PHP 5.3, you might also think about something like the following:

<?php

// First Array To Compare
$a1 = array('foo','bar','c');

// Target Array
$b1 = array('foo','bar');


// Evaluation Function - we pass guard and target array
$b=true;
$test = function($x) use (&$b, $b1) {
        if (!in_array($x,$b1)) {
                $b=false;
        }
};


// Actual Test on array (can be repeated with others, but guard 
// needs to be initialized again, due to by reference assignment above)
array_walk($a1, $test);
var_dump($b);

This relies on a closure; comparison function can become much more powerful. Good luck!

How to get to Model or Viewbag Variables in a Script Tag

try this method

<script type="text/javascript">

    function set(value) {
        return value;
    }

    alert(set(@Html.Raw(Json.Encode(Model.Message)))); // Message set from controller
    alert(set(@Html.Raw(Json.Encode(ViewBag.UrMessage))));

</script>

Thanks

Can I convert long to int?

A possible way is to use the modulo operator to only let the values stay in the int32 range, and then cast it to int.

var intValue= (int)(longValue % Int32.MaxValue);

Can I add a custom attribute to an HTML tag?

I can think of a handy use for the custom tag "init". Include a JavaScript expression that gets evaluated at document.onLoad() time and provides a value for the tag, e.g.

<p>&lt;p&gt;The UTC date is &lt;span init="new Date().toUTCString()"&gt;?&lt;/span&gt;.&lt;p&gt;</p>

Some boilerplate JavaScript code would scan all the tags in the DOM at document.onload() time looking for the init attributes, evaluating the expressions that they contain, and assigning them to the containing tag's innerHTML. This would give HTML some of the power of JSP, PHP etc. Currently we have to split the HTML markup and the JavaScript code that illuminates it. Bugs love split code.

How to increase icons size on Android Home Screen?

If you want to change settings in the launcher, change icon size, or grid size just hold down on an empty part of your home screen. Tap the three Dots and there you go.

From https://forums.oneplus.net/threads/how-to-change-icon-and-grid-size-trebuchet-settings.84820/

When configuring the phone for first time I saw something about a grid somewhere, but couldn't find it again. Luckily I found the answer on the link above.

How to add elements of a Java8 stream into an existing List

targetList = sourceList.stream().flatmap(List::stream).collect(Collectors.toList());

Difference between final and effectively final

final is a variable declare with key word final , example:

final double pi = 3.14 ;

it remains final through out the program.

effectively final : any local variable or parameter that is assigned a value only once right now(or updated only once). It may not remain effectively final through out the program. so this means that effectively final variable might loose its effectively final property after immediately the time it gets assigned/updated at least one more assignment. example:

class EffectivelyFinal {

    public static void main(String[] args) {
        calculate(124,53);
    }

    public static void calculate( int operand1, int operand2){   
     int rem = 0;  //   operand1, operand2 and rem are effectively final here
     rem = operand1%2  // rem lost its effectively final property here because it gets its second assignment 
                       // operand1, operand2 are still effectively final here 
        class operators{

            void setNum(){
                operand1 =   operand2%2;  // operand1 lost its effectively final property here because it gets its second assignment
            }

            int add(){
                return rem + operand2;  // does not compile because rem is not effectively final
            }
            int multiply(){
                return rem * operand1;  // does not compile because both rem and operand1 are not effectively final
            }
        }   
   }    
}

How to cast Object to its actual type?

Implement an interface to call your function in your method
interface IMyInterface
{
 void MyinterfaceMethod();
}

IMyInterface MyObj = obj as IMyInterface;
if ( MyObj != null)
{
MyMethod(IMyInterface MyObj );
}

Expansion of variables inside single quotes in a command in Bash

Inside single quotes everything is preserved literally, without exception.

That means you have to close the quotes, insert something, and then re-enter again.

'before'"$variable"'after'
'before'"'"'after'
'before'\''after'

Word concatenation is simply done by juxtaposition. As you can verify, each of the above lines is a single word to the shell. Quotes (single or double quotes, depending on the situation) don't isolate words. They are only used to disable interpretation of various special characters, like whitespace, $, ;... For a good tutorial on quoting see Mark Reed's answer. Also relevant: Which characters need to be escaped in bash?

Do not concatenate strings interpreted by a shell

You should absolutely avoid building shell commands by concatenating variables. This is a bad idea similar to concatenation of SQL fragments (SQL injection!).

Usually it is possible to have placeholders in the command, and to supply the command together with variables so that the callee can receive them from the invocation arguments list.

For example, the following is very unsafe. DON'T DO THIS

script="echo \"Argument 1 is: $myvar\""
/bin/sh -c "$script"

If the contents of $myvar is untrusted, here is an exploit:

myvar='foo"; echo "you were hacked'

Instead of the above invocation, use positional arguments. The following invocation is better -- it's not exploitable:

script='echo "arg 1 is: $1"'
/bin/sh -c "$script" -- "$myvar"

Note the use of single ticks in the assignment to script, which means that it's taken literally, without variable expansion or any other form of interpretation.

Can the :not() pseudo-class have multiple arguments?

Starting from CSS Selectors 4 using multiple arguments in the :not selector becomes possible (see here).

In CSS3, the :not selector only allows 1 selector as an argument. In level 4 selectors, it can take a selector list as an argument.

Example:

/* In this example, all p elements will be red, except for 
   the first child and the ones with the class special. */

p:not(:first-child, .special) {
  color: red;
}

Unfortunately, browser support is limited. For now, it only works in Safari.

What is the best free SQL GUI for Linux for various DBMS systems

I use SQLite Database Browser for SQLite3 currently and it's pretty useful. Works across Windows/OS X/Linux and is lightweight and fast. Slightly unstable with executing SQL on the DB if it's incorrectly formatted.

Edit: I have recently discovered SQLite Manager, a plugin for Firefox. Obviously you need to run Firefox, but you can close all windows and just run it "standalone". It's very feature complete, amazingly stable and it remembers your databases! It has tonnes of features so I've moved away from SQLite Database Browser as the instability and lack of features is too much to bear.

Determine if string is in list in JavaScript

RegExp is universal, but I understand that you're working with arrays. So, check out this approach. I use to use it, and it's very effective and blazing fast!

var str = 'some string with a';
var list = ['a', 'b', 'c'];
var rx = new RegExp(list.join('|'));

rx.test(str);

You can also apply some modifications, i.e.:

One-liner

new RegExp(list.join('|')).test(str);

Case insensitive

var rx = new RegExp(list.join('|').concat('/i'));


And many others!

How to get the current branch name in Git?

Sorry this is another command-line answer, but that's what I was looking for when I found this question and many of these answers were helpful. My solution is the following bash shell function:

get_branch () {
    git rev-parse --abbrev-ref HEAD | grep -v HEAD || \
    git describe --exact-match HEAD 2> /dev/null || \
    git rev-parse HEAD
}

This should always give me something both human-readable and directly usable as an argument to git checkout.

  • on a local branch: feature/HS-0001
  • on a tagged commit (detached): v3.29.5
  • on a remote branch (detached, not tagged): SHA1
  • on any other detached commit: SHA1

Where can I set environment variables that crontab will use?

If you start the scripts you are executing through cron with:

#!/bin/bash -l

They should pick up your ~/.bash_profile environment variables

Easiest way to split a string on newlines in .NET?

Try to avoid using string.Split for a general solution, because you'll use more memory everywhere you use the function -- the original string, and the split copy, both in memory. Trust me that this can be one hell of a problem when you start to scale -- run a 32-bit batch-processing app processing 100MB documents, and you'll crap out at eight concurrent threads. Not that I've been there before...

Instead, use an iterator like this;

    public static IEnumerable<string> SplitToLines(this string input)
    {
        if (input == null)
        {
            yield break;
        }

        using (System.IO.StringReader reader = new System.IO.StringReader(input))
        {
            string line;
            while( (line = reader.ReadLine()) != null)
            {
                yield return line;
            }
        }
    }

This will allow you to do a more memory efficient loop around your data;

foreach(var line in document.SplitToLines()) 
{
    // one line at a time...
}

Of course, if you want it all in memory, you can do this;

var allTheLines = document.SplitToLines.ToArray();

How can I show data using a modal when clicking a table row (using bootstrap)?

The solution from PSL will not work in Firefox. FF accepts event only as a formal parameter. So you have to find another way to identify the selected row. My solution is something like this:

...
$('#mySelector')
  .on('show.bs.modal', function(e) {
  var mid;


  if (navigator.userAgent.toLowerCase().indexOf('firefox') > -1) 
    mid = $(e.relatedTarget).data('id');
  else
    mid = $(event.target).closest('tr').data('id');

...

What is Express.js?

Express is a module framework for Node that you can use for applications that are based on server/s that will "listen" for any input/connection requests from clients. When you use it in Node, it is just saying that you are requesting the use of the built-in Express file from your Node modules.

Express is the "backbone" of a lot of Web Apps that have their back end in NodeJS. From what I know, its primary asset being the providence of a routing system that handles the services of "interaction" between 2 hosts. There are plenty of alternatives for it, such as Sails.

SSL Connection / Connection Reset with IISExpress

If you need to use a port outside of the 44300-44399 range, here's a workaround:

  • Create a new site in IIS (not Express)
  • Bind HTTPS to the port you need
  • For SSL Certificate, choose IIS Express Development Certificate
  • Once the site is created, stop it, since it doesn't actually need to be running

This registers the IIS Express Development certificate with that port and is the easiest way I've found to get around the 44300-44399 range requirement.

SVN "Already Locked Error"

I had the same problem, It was solved when I checked the below checkbox

Should I use @EJB or @Inject

Injection already existed in Java EE 5 with the @Resource, @PersistentUnit or @EJB annotations, for example. But it was limited to certain resources (datasource, EJB . . .) and into certain components (Servlets, EJBs, JSF backing bean . . .). With CDI you can inject nearly anything anywhere thanks to the @Inject annotation.

What does {0} mean when found in a string in C#?

You are printing a formatted string. The {0} means to insert the first parameter following the format string; in this case the value associated with the key "rtf".

For String.Format, which is similar, if you had something like

//            Format string                    {0}           {1}
String.Format("This {0}.  The value is {1}.",  "is a test",  42 ) 

you'd create a string "This is a test. The value is 42".

You can also use expressions, and print values out multiple times:

//            Format string              {0} {1}  {2}
String.Format("Fib: {0}, {0}, {1}, {2}", 1,  1+1, 1+2) 

yielding "Fib: 1, 1, 2, 3"

See more at http://msdn.microsoft.com/en-us/library/txafckwd.aspx, which talks about composite formatting.

How can I force component to re-render with hooks in React?

You should preferably only have your component depend on state and props and it will work as expected, but if you really need a function to force the component to re-render, you could use the useState hook and call the function when needed.

Example

_x000D_
_x000D_
const { useState, useEffect } = React;_x000D_
_x000D_
function Foo() {_x000D_
  const [, forceUpdate] = useState();_x000D_
_x000D_
  useEffect(() => {_x000D_
    setTimeout(forceUpdate, 2000);_x000D_
  }, []);_x000D_
_x000D_
  return <div>{Date.now()}</div>;_x000D_
}_x000D_
_x000D_
ReactDOM.render(<Foo />, document.getElementById("root"));
_x000D_
<script src="https://unpkg.com/[email protected]/umd/react.production.min.js"></script>_x000D_
<script src="https://unpkg.com/[email protected]/umd/react-dom.production.min.js"></script>_x000D_
_x000D_
<div id="root"></div>
_x000D_
_x000D_
_x000D_

Closing WebSocket correctly (HTML5, Javascript)

Very simple, you close it :)

var myWebSocket = new WebSocket("ws://example.org"); 
myWebSocket.send("Hello Web Sockets!"); 
myWebSocket.close();

Did you check also the following site And check the introduction article of Opera

How to center a window on the screen in Tkinter?

I have found a solution for the same question on this site

from tkinter import Tk
from tkinter.ttk import Label
root = Tk()
Label(root, text="Hello world").pack()

# Apparently a common hack to get the window size. Temporarily hide the
# window to avoid update_idletasks() drawing the window in the wrong
# position.
root.withdraw()
root.update_idletasks()  # Update "requested size" from geometry manager

x = (root.winfo_screenwidth() - root.winfo_reqwidth()) / 2
y = (root.winfo_screenheight() - root.winfo_reqheight()) / 2
root.geometry("+%d+%d" % (x, y))

# This seems to draw the window frame immediately, so only call deiconify()
# after setting correct window position
root.deiconify()
root.mainloop()

sure, I changed it correspondingly to my purposes, it works.

How can I edit a view using phpMyAdmin 3.2.4?

Just export you view and you will have all SQL need to make some change on it.

Just need to add your change in SQL query for the view and change :

CREATE for CREATE OR REPLACE

When to use .First and when to use .FirstOrDefault with LINQ?

Ok let me give my two cents. First / Firstordefault are for when you use the second constructor. I won't explain what it is, but it's when you would potentially always use one because you don't want to cause an exception.

person = tmp.FirstOrDefault(new Func<Person, bool>((p) =>
{
    return string.IsNullOrEmpty(p.Relationship);
}));

MySQL trigger if condition exists

Try to do...

 DELIMITER $$
        CREATE TRIGGER aumentarsalario 
        BEFORE INSERT 
        ON empregados
        FOR EACH ROW
        BEGIN
          if (NEW.SALARIO < 900) THEN 
             set NEW.SALARIO = NEW.SALARIO + (NEW.SALARIO * 0.1);
          END IF;
        END $$
  DELIMITER ;

Printing integer variable and string on same line in SQL

declare @x INT = 1 /* Declares an integer variable named "x" with the value of 1 */
    
PRINT 'There are ' + CAST(@x AS VARCHAR) + ' alias combinations did not match a record' /* Prints a string concatenated with x casted as a varchar */

How can I pad an integer with zeros on the left?

int x = 1;
System.out.format("%05d",x);

if you want to print the formatted text directly onto the screen.

How can I break up this long line in Python?

For anyone who is also trying to call .format() on a long string, and is unable to use some of the most popular string wrapping techniques without breaking the subsequent .format( call, you can do str.format("", 1, 2) instead of "".format(1, 2). This lets you break the string with whatever technique you like. For example:

logger.info("Skipping {0} because its thumbnail was already in our system as {1}.".format(line[indexes['url']], video.title))

can be

logger.info(str.format(("Skipping {0} because its thumbnail was already"
+ "in our system as {1}"), line[indexes['url']], video.title))

Otherwise, the only possibility is using line ending continuations, which I personally am not a fan of.

How to See the Contents of Windows library (*.lib)

DUMPBIN /EXPORTS Will get most of that information and hitting MSDN will get the rest.

Get one of the Visual Studio packages; C++

ReCaptcha API v2 Styling

In case someone struggling with the recaptcha of contact form 7 (wordpress) here is a solution working for me

.wpcf7-recaptcha{
clear: both;
float: left;
}
.wpcf7-recaptcha{
margin-right: 6px;
width: 206px;
height: 65px;
overflow: hidden;
border-right: 1px solid #D3D3D3;
}
.wpcf7-recaptcha iframe{
padding-bottom: 15px;
border-bottom: 1px solid #D3D3D3;
background: #F9F9F9;
border-left: 1px solid #d3d3d3;
}

enter image description here

Background Image for Select (dropdown) does not work in Chrome

you can use the below css styles for all browsers except Firefox 30

select {
  background: url(dropdown_arw.png) no-repeat right center;
  appearance: none;
  -moz-appearance: none;
  -webkit-appearance: none;
  width: 90px;
  text-indent: 0.01px;
  text-overflow: "";
}

demo page - http://kvijayanand.in/jquery-plugin/test.html

Updated

here is solution for Firefox 30. little trick for custom select elements in firefox :-moz-any() css pseudo class.

http://blog.kvijayanand.in/customize-select-arrow-css/

What does 'index 0 is out of bounds for axis 0 with size 0' mean?

In numpy, index and dimension numbering starts with 0. So axis 0 means the 1st dimension. Also in numpy a dimension can have length (size) 0. The simplest case is:

In [435]: x = np.zeros((0,), int)
In [436]: x
Out[436]: array([], dtype=int32)
In [437]: x[0]
...
IndexError: index 0 is out of bounds for axis 0 with size 0

I also get it if x = np.zeros((0,5), int), a 2d array with 0 rows, and 5 columns.

So someplace in your code you are creating an array with a size 0 first axis.

When asking about errors, it is expected that you tell us where the error occurs.

Also when debugging problems like this, the first thing you should do is print the shape (and maybe the dtype) of the suspected variables.

Applied to pandas

Resolving the error:

  1. Use a try-except block
  2. Verify the size of the array is not 0
    • if x.size != 0:

How to fix "Referenced assembly does not have a strong name" error?

For me, the problem was a NuGet package without a strong name. The solution was to install StrongNamer from NuGet, which automatically adds a strong name to all referenced assemblies. Just simply having it referenced in the project fixed my issue.

Download file from web in Python 3

If you want to obtain the contents of a web page into a variable, just read the response of urllib.request.urlopen:

import urllib.request
...
url = 'http://example.com/'
response = urllib.request.urlopen(url)
data = response.read()      # a `bytes` object
text = data.decode('utf-8') # a `str`; this step can't be used if data is binary

The easiest way to download and save a file is to use the urllib.request.urlretrieve function:

import urllib.request
...
# Download the file from `url` and save it locally under `file_name`:
urllib.request.urlretrieve(url, file_name)
import urllib.request
...
# Download the file from `url`, save it in a temporary directory and get the
# path to it (e.g. '/tmp/tmpb48zma.txt') in the `file_name` variable:
file_name, headers = urllib.request.urlretrieve(url)

But keep in mind that urlretrieve is considered legacy and might become deprecated (not sure why, though).

So the most correct way to do this would be to use the urllib.request.urlopen function to return a file-like object that represents an HTTP response and copy it to a real file using shutil.copyfileobj.

import urllib.request
import shutil
...
# Download the file from `url` and save it locally under `file_name`:
with urllib.request.urlopen(url) as response, open(file_name, 'wb') as out_file:
    shutil.copyfileobj(response, out_file)

If this seems too complicated, you may want to go simpler and store the whole download in a bytes object and then write it to a file. But this works well only for small files.

import urllib.request
...
# Download the file from `url` and save it locally under `file_name`:
with urllib.request.urlopen(url) as response, open(file_name, 'wb') as out_file:
    data = response.read() # a `bytes` object
    out_file.write(data)

It is possible to extract .gz (and maybe other formats) compressed data on the fly, but such an operation probably requires the HTTP server to support random access to the file.

import urllib.request
import gzip
...
# Read the first 64 bytes of the file inside the .gz archive located at `url`
url = 'http://example.com/something.gz'
with urllib.request.urlopen(url) as response:
    with gzip.GzipFile(fileobj=response) as uncompressed:
        file_header = uncompressed.read(64) # a `bytes` object
        # Or do anything shown above using `uncompressed` instead of `response`.

How to split a file into equal parts, without breaking individual lines?

If you mean an equal number of lines, split has an option for this:

split --lines=75

If you need to know what that 75 should really be for N equal parts, its:

lines_per_part = int(total_lines + N - 1) / N

where total lines can be obtained with wc -l.

See the following script for an example:

#!/usr/bin/bash

# Configuration stuff

fspec=qq.c
num_files=6

# Work out lines per file.

total_lines=$(wc -l <${fspec})
((lines_per_file = (total_lines + num_files - 1) / num_files))

# Split the actual file, maintaining lines.

split --lines=${lines_per_file} ${fspec} xyzzy.

# Debug information

echo "Total lines     = ${total_lines}"
echo "Lines  per file = ${lines_per_file}"    
wc -l xyzzy.*

This outputs:

Total lines     = 70
Lines  per file = 12
  12 xyzzy.aa
  12 xyzzy.ab
  12 xyzzy.ac
  12 xyzzy.ad
  12 xyzzy.ae
  10 xyzzy.af
  70 total

More recent versions of split allow you to specify a number of CHUNKS with the -n/--number option. You can therefore use something like:

split --number=l/6 ${fspec} xyzzy.

(that's ell-slash-six, meaning lines, not one-slash-six).

That will give you roughly equal files in terms of size, with no mid-line splits.

I mention that last point because it doesn't give you roughly the same number of lines in each file, more the same number of characters.

So, if you have one 20-character line and 19 1-character lines (twenty lines in total) and split to five files, you most likely won't get four lines in every file.

What is the function __construct used for?

The constructor is a method which is automatically called on class instantiation. Which means the contents of a constructor are processed without separate method calls. The contents of a the class keyword parenthesis are passed to the constructor method.

Apply formula to the entire column

To be clear when you us the drag indicator it will only copy the cell values down the column whilst there is a value in the adjacent cell in a given row. As soon as the drag operation sees an adjacent cell that is blank it will stop copying the formula down.

.e.g

1,a,b
2,a
3,
4,a

If the above is a spreadsheet then using the double click drag indicator on the 'b' cell will fill row 2 but not row three or four.

Convert dd-mm-yyyy string to date

Using moment.js example:

var from = '11-04-2017' // OR $("#datepicker").val();
var milliseconds = moment(from, "DD-MM-YYYY").format('x');
var f = new Date(milliseconds)

cordova Android requirements failed: "Could not find an installed version of Gradle"

SOLUTION FOR Mac

Sample problem but I found my solution with brew.
1. Make sure you have the latest Android Studio installed.
2. Confirm from SDK manager that you have the required SDKs installed.
3. (optional)you could have an AVD installed as well.
4. install Homebrew.

/usr/bin/ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)"

5. Then run brew update to make sure Homebrew is up to date.

brew update

6. Run brew doctor to make sure everything is safe

brew doctor

7. Add Homebrew's location to your $PATH in your .bash_profile or .zshrc file.

export PATH="/usr/local/bin:$PATH"

8. If you don't have Node already installed, add:

brew install node

9. (Optional) To test out your Node and npm install, try installing Grunt (you might be asked to run with sudo)

npm install -g grunt-cli

10. Install Gradle

brew install gradle

Run: cordova run android --device with you device connected on a Mac and you have gradle working this time.

How do I make bootstrap table rows clickable?

That code transforms any bootstrap table row that has data-href attribute set into a clickable element

Note: data-href attribute is a valid tr attribute (HTML5), href attributes on tr element are not.

$(function(){
    $('.table tr[data-href]').each(function(){
        $(this).css('cursor','pointer').hover(
            function(){ 
                $(this).addClass('active'); 
            },  
            function(){ 
                $(this).removeClass('active'); 
            }).click( function(){ 
                document.location = $(this).attr('data-href'); 
            }
        );
    });
});

set dropdown value by text using jquery

This is a method that works based on the text of the option, not the index. Just tested.

var theText = "GOOGLE";
$("#HowYouKnow option:contains(" + theText + ")").attr('selected', 'selected');

Or, if there are similar values (thanks shanabus):

$("#HowYouKnow option").each(function() {
  if($(this).text() == theText) {
    $(this).attr('selected', 'selected');            
  }                        
});

What is the Python 3 equivalent of "python -m SimpleHTTPServer"

The equivalent is:

python3 -m http.server

How do I kill all the processes in Mysql "show processlist"?

Query 1 select concat('KILL ',id,';') from information_schema.processlist where user='username' into outfile '/tmp/a.txt';

Query 2 source a.txt

This will enable you to kill all the queries in show processlist by specific user.

MongoDB: How to find out if an array field contains an element?

It seems like the $in operator would serve your purposes just fine.

You could do something like this (pseudo-query):

if (db.courses.find({"students" : {"$in" : [studentId]}, "course" : courseId }).count() > 0) {
  // student is enrolled in class
}

Alternatively, you could remove the "course" : courseId clause and get back a set of all classes the student is enrolled in.

Differences between Html.TextboxFor and Html.EditorFor in MVC and Razor

This is one of the basic differences not mentioned in previous comments:
Readonly property will work with textbox for and it will not work with EditorFor.

@Html.TextBoxFor(model => model.DateSoldOn, new { @readonly = "readonly" })

Above code works, where as with following you can't make control to readonly.

@Html.EditorFor(model => model.DateSoldOn, new { @readonly = "readonly" })

Set initially selected item in Select list in Angular2

If you use

<select [ngModel]="object">
    <option *ngFor="let object of objects" [ngValue]="object">{{object.name}}</option>
</select>

You need to set the property object in you components class to the item from objects that you want to have pre-selected.

class MyComponent {
  object;
  objects = [{name: 'a'}, {name: 'b'}, {name: 'c'}];
  constructor() {
    this.object = this.objects[1];
  }
}

AngularJS. How to call controller function from outside of controller component

I would rather include the factory as dependencies on the controllers than inject them with their own line of code: http://jsfiddle.net/XqDxG/550/

myModule.factory('mySharedService', function($rootScope) {
    return sharedService = {thing:"value"};
});

function ControllerZero($scope, mySharedService) {
    $scope.thing = mySharedService.thing;

ControllerZero.$inject = ['$scope', 'mySharedService'];

org.xml.sax.SAXParseException: Premature end of file for *VALID* XML

Are you sure that the XML file is in the correct character encoding? FileReader always uses the platform default encoding, so if the "working" server had a default encoding of (say) ISO-8859-1 and the "problem" server uses UTF-8 you would see this error if the XML contains any non-ASCII characters.

Does it work if you create the InputSource from a FileInputStream instead of a FileReader?