Programs & Examples On #Vertex

A vertex is a single point in a 3D object, used for simple model creation or advanced animation systems.

Visual Studio 2017 errors on standard headers

I got the errors to go away by installing the Windows Universal CRT SDK component, which adds support for legacy Windows SDKs. You can install this using the Visual Studio Installer:

enter image description here

If the problem still persists, you should change the Target SDK in the Visual Studio Project : check whether the Windows SDK version is 10.0.15063.0.

In : Project -> Properties -> General -> Windows SDK Version -> select 10.0.15063.0.

Then errno.h and other standard files will be found and it will compile.

Error LNK2019 unresolved external symbol _main referenced in function "int __cdecl invoke_main(void)" (?invoke_main@@YAHXZ)

If it is a windows system, then it may be because you are using 32 bit winpcap library in a 64 bit pc or vie versa. If it is a 64 bit pc then copy the winpcap library and header packet.lib and wpcap.lib from winpcap/lib/x64 to the winpcap/lib directory and overwrite the existing

Python Key Error=0 - Can't find Dict error in code

Try this:

class Flonetwork(Object):
    def __init__(self,adj = {},flow={}):
        self.adj = adj
        self.flow = flow

Drawing Circle with OpenGL

glBegin(GL_POLYGON);                        // Middle circle
double radius = 0.2;
double ori_x = 0.0;                         // the origin or center of circle
double ori_y = 0.0;
for (int i = 0; i <= 300; i++) {
    double angle = 2 * PI * i / 300;
    double x = cos(angle) * radius;
    double y = sin(angle) * radius;
    glVertex2d(ori_x + x, ori_y + y);
}
glEnd();

Python, TypeError: unhashable type: 'list'

The problem is that you can't use a list as the key in a dict, since dict keys need to be immutable. Use a tuple instead.

This is a list:

[x, y]

This is a tuple:

(x, y)

Note that in most cases, the ( and ) are optional, since , is what actually defines a tuple (as long as it's not surrounded by [] or {}, or used as a function argument).

You might find the section on tuples in the Python tutorial useful:

Though tuples may seem similar to lists, they are often used in different situations and for different purposes. Tuples are immutable, and usually contain an heterogeneous sequence of elements that are accessed via unpacking (see later in this section) or indexing (or even by attribute in the case of namedtuples). Lists are mutable, and their elements are usually homogeneous and are accessed by iterating over the list.

And in the section on dictionaries:

Unlike sequences, which are indexed by a range of numbers, dictionaries are indexed by keys, which can be any immutable type; strings and numbers can always be keys. Tuples can be used as keys if they contain only strings, numbers, or tuples; if a tuple contains any mutable object either directly or indirectly, it cannot be used as a key. You can’t use lists as keys, since lists can be modified in place using index assignments, slice assignments, or methods like append() and extend().


In case you're wondering what the error message means, it's complaining because there's no built-in hash function for lists (by design), and dictionaries are implemented as hash tables.

How to create a shared library with cmake?

Always specify the minimum required version of cmake

cmake_minimum_required(VERSION 3.9)

You should declare a project. cmake says it is mandatory and it will define convenient variables PROJECT_NAME, PROJECT_VERSION and PROJECT_DESCRIPTION (this latter variable necessitate cmake 3.9):

project(mylib VERSION 1.0.1 DESCRIPTION "mylib description")

Declare a new library target. Please avoid the use of file(GLOB ...). This feature does not provide attended mastery of the compilation process. If you are lazy, copy-paste output of ls -1 sources/*.cpp :

add_library(mylib SHARED
    sources/animation.cpp
    sources/buffers.cpp
    [...]
)

Set VERSION property (optional but it is a good practice):

set_target_properties(mylib PROPERTIES VERSION ${PROJECT_VERSION})

You can also set SOVERSION to a major number of VERSION. So libmylib.so.1 will be a symlink to libmylib.so.1.0.0.

set_target_properties(mylib PROPERTIES SOVERSION 1)

Declare public API of your library. This API will be installed for the third-party application. It is a good practice to isolate it in your project tree (like placing it include/ directory). Notice that, private headers should not be installed and I strongly suggest to place them with the source files.

set_target_properties(mylib PROPERTIES PUBLIC_HEADER include/mylib.h)

If you work with subdirectories, it is not very convenient to include relative paths like "../include/mylib.h". So, pass a top directory in included directories:

target_include_directories(mylib PRIVATE .)

or

target_include_directories(mylib PRIVATE include)
target_include_directories(mylib PRIVATE src)

Create an install rule for your library. I suggest to use variables CMAKE_INSTALL_*DIR defined in GNUInstallDirs:

include(GNUInstallDirs)

And declare files to install:

install(TARGETS mylib
    LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR}
    PUBLIC_HEADER DESTINATION ${CMAKE_INSTALL_INCLUDEDIR})

You may also export a pkg-config file. This file allows a third-party application to easily import your library:

Create a template file named mylib.pc.in (see pc(5) manpage for more information):

prefix=@CMAKE_INSTALL_PREFIX@
exec_prefix=@CMAKE_INSTALL_PREFIX@
libdir=${exec_prefix}/@CMAKE_INSTALL_LIBDIR@
includedir=${prefix}/@CMAKE_INSTALL_INCLUDEDIR@

Name: @PROJECT_NAME@
Description: @PROJECT_DESCRIPTION@
Version: @PROJECT_VERSION@

Requires:
Libs: -L${libdir} -lmylib
Cflags: -I${includedir}

In your CMakeLists.txt, add a rule to expand @ macros (@ONLY ask to cmake to not expand variables of the form ${VAR}):

configure_file(mylib.pc.in mylib.pc @ONLY)

And finally, install generated file:

install(FILES ${CMAKE_BINARY_DIR}/mylib.pc DESTINATION ${CMAKE_INSTALL_DATAROOTDIR}/pkgconfig)

You may also use cmake EXPORT feature. However, this feature is only compatible with cmake and I find it difficult to use.

Finally the entire CMakeLists.txt should looks like:

cmake_minimum_required(VERSION 3.9)
project(mylib VERSION 1.0.1 DESCRIPTION "mylib description")
include(GNUInstallDirs)
add_library(mylib SHARED src/mylib.c)
set_target_properties(mylib PROPERTIES
    VERSION ${PROJECT_VERSION}
    SOVERSION 1
    PUBLIC_HEADER api/mylib.h)
configure_file(mylib.pc.in mylib.pc @ONLY)
target_include_directories(mylib PRIVATE .)
install(TARGETS mylib
    LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR}
    PUBLIC_HEADER DESTINATION ${CMAKE_INSTALL_INCLUDEDIR})
install(FILES ${CMAKE_BINARY_DIR}/mylib.pc
    DESTINATION ${CMAKE_INSTALL_DATAROOTDIR}/pkgconfig)

C++ "Access violation reading location" Error

You haven't posted the findvertex method, but Access Reading Violation with an offset like 0x00000048 means that the Vertex* f; in your getCost function is receiving null, and when trying to access the member adj in the null Vertex pointer (that is, in f), it is offsetting to adj (in this case, 72 bytes ( 0x48 bytes in decimal )), it's reading near the 0 or null memory address.

Doing a read like this violates Operating-System protected memory, and more importantly means whatever you're pointing at isn't a valid pointer. Make sure findvertex isn't returning null, or do a comparisong for null on f before using it to keep yourself sane (or use an assert):

assert( f != null ); // A good sanity check

EDIT:

If you have a map for doing something like a find, you can just use the map's find method to make sure the vertex exists:

Vertex* Graph::findvertex(string s)
{
    vmap::iterator itr = map1.find( s );
    if ( itr == map1.end() )
    {
        return NULL;
    }
    return itr->second;
}

Just make sure you're still careful to handle the error case where it does return NULL. Otherwise, you'll keep getting this access violation.

Subscript out of bounds - general definition and solution?

Only an addition to the above responses: A possibility in such cases is that you are calling an object, that for some reason is not available to your query. For example you may subset by row names or column names, and you will receive this error message when your requested row or column is not part of the data matrix or data frame anymore. Solution: As a short version of the responses above: you need to find the last working row name or column name, and the next called object should be the one that could not be found. If you run parallel codes like "foreach", then you need to convert your code to a for loop to be able to troubleshoot it.

What is the HTML unicode character for a "tall" right chevron?

I use ? (0x25B8) for the right arrow, often to show a collapsed list; and I pair it with ? (0x25BE) to show the list opened up. Both are unobtrusive.

Why is the time complexity of both DFS and BFS O( V + E )

An intuitive explanation to this is by simply analysing a single loop:

  1. visit a vertex -> O(1)
  2. a for loop on all the incident edges -> O(e) where e is a number of edges incident on a given vertex v.

So the total time for a single loop is O(1)+O(e). Now sum it for each vertex as each vertex is visited once. This gives

For every V
=> 

    O(1)
    +

    O(e)

=> O(V) + O(E)

How can I add a hint or tooltip to a label in C# Winforms?

Just to share my idea...

I created a custom class to inherit the Label class. I added a private variable assigned as a Tooltip class and a public property, TooltipText. Then, gave it a MouseEnter delegate method. This is an easy way to work with multiple Label controls and not have to worry about assigning your Tooltip control for each Label control.

    public partial class ucLabel : Label
    {
        private ToolTip _tt = new ToolTip();

        public string TooltipText { get; set; }

        public ucLabel() : base() {
            _tt.AutoPopDelay = 1500;
            _tt.InitialDelay = 400;
//            _tt.IsBalloon = true;
            _tt.UseAnimation = true;
            _tt.UseFading = true;
            _tt.Active = true;
            this.MouseEnter += new EventHandler(this.ucLabel_MouseEnter);
        }

        private void ucLabel_MouseEnter(object sender, EventArgs ea)
        {
            if (!string.IsNullOrEmpty(this.TooltipText))
            {
                _tt.SetToolTip(this, this.TooltipText);
                _tt.Show(this.TooltipText, this.Parent);
            }
        }
    }

In the form or user control's InitializeComponent method (the Designer code), reassign your Label control to the custom class:

this.lblMyLabel = new ucLabel();

Also, change the private variable reference in the Designer code:

private ucLabel lblMyLabel;

Negative weights using Dijkstra's Algorithm

"2) Can we use Dijksra’s algorithm for shortest paths for graphs with negative weights – one idea can be, calculate the minimum weight value, add a positive value (equal to absolute value of minimum weight value) to all weights and run the Dijksra’s algorithm for the modified graph. Will this algorithm work?"

This absolutely doesn't work unless all shortest paths have same length. For example given a shortest path of length two edges, and after adding absolute value to each edge, then the total path cost is increased by 2 * |max negative weight|. On the other hand another path of length three edges, so the path cost is increased by 3 * |max negative weight|. Hence, all distinct paths are increased by different amounts.

Java: how to represent graphs?

class Graph<E> {
    private List<Vertex<E>> vertices;

    private static class Vertex<E> {
        E elem;
        List<Vertex<E>> neighbors;
    }
}

gcc makefile error: "No rule to make target ..."

In my case the path is not set in VPATH, after added the error gone.

How to convert a 3D point into 2D perspective projection?

I see this question is a bit old, but I decided to give an answer anyway for those who find this question by searching.
The standard way to represent 2D/3D transformations nowadays is by using homogeneous coordinates. [x,y,w] for 2D, and [x,y,z,w] for 3D. Since you have three axes in 3D as well as translation, that information fits perfectly in a 4x4 transformation matrix. I will use column-major matrix notation in this explanation. All matrices are 4x4 unless noted otherwise.
The stages from 3D points and to a rasterized point, line or polygon looks like this:

  1. Transform your 3D points with the inverse camera matrix, followed with whatever transformations they need. If you have surface normals, transform them as well but with w set to zero, as you don't want to translate normals. The matrix you transform normals with must be isotropic; scaling and shearing makes the normals malformed.
  2. Transform the point with a clip space matrix. This matrix scales x and y with the field-of-view and aspect ratio, scales z by the near and far clipping planes, and plugs the 'old' z into w. After the transformation, you should divide x, y and z by w. This is called the perspective divide.
  3. Now your vertices are in clip space, and you want to perform clipping so you don't render any pixels outside the viewport bounds. Sutherland-Hodgeman clipping is the most widespread clipping algorithm in use.
  4. Transform x and y with respect to w and the half-width and half-height. Your x and y coordinates are now in viewport coordinates. w is discarded, but 1/w and z is usually saved because 1/w is required to do perspective-correct interpolation across the polygon surface, and z is stored in the z-buffer and used for depth testing.

This stage is the actual projection, because z isn't used as a component in the position any more.

The algorithms:

Calculation of field-of-view

This calculates the field-of view. Whether tan takes radians or degrees is irrelevant, but angle must match. Notice that the result reaches infinity as angle nears 180 degrees. This is a singularity, as it is impossible to have a focal point that wide. If you want numerical stability, keep angle less or equal to 179 degrees.

fov = 1.0 / tan(angle/2.0)

Also notice that 1.0 / tan(45) = 1. Someone else here suggested to just divide by z. The result here is clear. You would get a 90 degree FOV and an aspect ratio of 1:1. Using homogeneous coordinates like this has several other advantages as well; we can for example perform clipping against the near and far planes without treating it as a special case.

Calculation of the clip matrix

This is the layout of the clip matrix. aspectRatio is Width/Height. So the FOV for the x component is scaled based on FOV for y. Far and near are coefficients which are the distances for the near and far clipping planes.

[fov * aspectRatio][        0        ][        0              ][        0       ]
[        0        ][       fov       ][        0              ][        0       ]
[        0        ][        0        ][(far+near)/(far-near)  ][        1       ]
[        0        ][        0        ][(2*near*far)/(near-far)][        0       ]

Screen Projection

After clipping, this is the final transformation to get our screen coordinates.

new_x = (x * Width ) / (2.0 * w) + halfWidth;
new_y = (y * Height) / (2.0 * w) + halfHeight;

Trivial example implementation in C++

#include <vector>
#include <cmath>
#include <stdexcept>
#include <algorithm>

struct Vector
{
    Vector() : x(0),y(0),z(0),w(1){}
    Vector(float a, float b, float c) : x(a),y(b),z(c),w(1){}

    /* Assume proper operator overloads here, with vectors and scalars */
    float Length() const
    {
        return std::sqrt(x*x + y*y + z*z);
    }
    
    Vector Unit() const
    {
        const float epsilon = 1e-6;
        float mag = Length();
        if(mag < epsilon){
            std::out_of_range e("");
            throw e;
        }
        return *this / mag;
    }
};

inline float Dot(const Vector& v1, const Vector& v2)
{
    return v1.x*v2.x + v1.y*v2.y + v1.z*v2.z;
}

class Matrix
{
    public:
    Matrix() : data(16)
    {
        Identity();
    }
    void Identity()
    {
        std::fill(data.begin(), data.end(), float(0));
        data[0] = data[5] = data[10] = data[15] = 1.0f;
    }
    float& operator[](size_t index)
    {
        if(index >= 16){
            std::out_of_range e("");
            throw e;
        }
        return data[index];
    }
    Matrix operator*(const Matrix& m) const
    {
        Matrix dst;
        int col;
        for(int y=0; y<4; ++y){
            col = y*4;
            for(int x=0; x<4; ++x){
                for(int i=0; i<4; ++i){
                    dst[x+col] += m[i+col]*data[x+i*4];
                }
            }
        }
        return dst;
    }
    Matrix& operator*=(const Matrix& m)
    {
        *this = (*this) * m;
        return *this;
    }

    /* The interesting stuff */
    void SetupClipMatrix(float fov, float aspectRatio, float near, float far)
    {
        Identity();
        float f = 1.0f / std::tan(fov * 0.5f);
        data[0] = f*aspectRatio;
        data[5] = f;
        data[10] = (far+near) / (far-near);
        data[11] = 1.0f; /* this 'plugs' the old z into w */
        data[14] = (2.0f*near*far) / (near-far);
        data[15] = 0.0f;
    }

    std::vector<float> data;
};

inline Vector operator*(const Vector& v, const Matrix& m)
{
    Vector dst;
    dst.x = v.x*m[0] + v.y*m[4] + v.z*m[8 ] + v.w*m[12];
    dst.y = v.x*m[1] + v.y*m[5] + v.z*m[9 ] + v.w*m[13];
    dst.z = v.x*m[2] + v.y*m[6] + v.z*m[10] + v.w*m[14];
    dst.w = v.x*m[3] + v.y*m[7] + v.z*m[11] + v.w*m[15];
    return dst;
}

typedef std::vector<Vector> VecArr;
VecArr ProjectAndClip(int width, int height, float near, float far, const VecArr& vertex)
{
    float halfWidth = (float)width * 0.5f;
    float halfHeight = (float)height * 0.5f;
    float aspect = (float)width / (float)height;
    Vector v;
    Matrix clipMatrix;
    VecArr dst;
    clipMatrix.SetupClipMatrix(60.0f * (M_PI / 180.0f), aspect, near, far);
    /*  Here, after the perspective divide, you perform Sutherland-Hodgeman clipping 
        by checking if the x, y and z components are inside the range of [-w, w].
        One checks each vector component seperately against each plane. Per-vertex
        data like colours, normals and texture coordinates need to be linearly
        interpolated for clipped edges to reflect the change. If the edge (v0,v1)
        is tested against the positive x plane, and v1 is outside, the interpolant
        becomes: (v1.x - w) / (v1.x - v0.x)
        I skip this stage all together to be brief.
    */
    for(VecArr::iterator i=vertex.begin(); i!=vertex.end(); ++i){
        v = (*i) * clipMatrix;
        v /= v.w; /* Don't get confused here. I assume the divide leaves v.w alone.*/
        dst.push_back(v);
    }

    /* TODO: Clipping here */

    for(VecArr::iterator i=dst.begin(); i!=dst.end(); ++i){
        i->x = (i->x * (float)width) / (2.0f * i->w) + halfWidth;
        i->y = (i->y * (float)height) / (2.0f * i->w) + halfHeight;
    }
    return dst;
}

If you still ponder about this, the OpenGL specification is a really nice reference for the maths involved. The DevMaster forums at http://www.devmaster.net/ have a lot of nice articles related to software rasterizers as well.

Interfaces with static fields in java for sharing 'constants'

According to JVM specification, fields and methods in a Interface can have only Public, Static, Final and Abstract. Ref from Inside Java VM

By default, all the methods in interface is abstract even tough you didn't mention it explicitly.

Interfaces are meant to give only specification. It can not contain any implementations. So To avoid implementing classes to change the specification, it is made final. Since Interface cannot be instantiated, they are made static to access the field using interface name.

Tomcat - maxThreads vs maxConnections

From Tomcat documentation, For blocking I/O (BIO), the default value of maxConnections is the value of maxThreads unless Executor (thread pool) is used in which case, the value of 'maxThreads' from Executor will be used instead. For Non-blocking IO, it doesn't seem to be dependent on maxThreads.

What is the difference between UTF-8 and Unicode?

If I may summarise what I gathered from this thread:

Unicode 'translates' characters to ordinal numbers (in decimal form).

à -> 224

UTF-8 is an encoding that 'translates' these ordinal numbers (in decimal form) to binary representations.

224 -> 11000011 10100000

Note that we're talking about the binary representation of 224, not its binary form, which is 0b11100000.

Running PHP script from the command line

I was looking for a resolution to this issue in Windows, and it seems to be that if you don't have the environments vars ok, you need to put the complete directory. For eg. with a file in the same directory than PHP:

F:\myfolder\php\php.exe -f F:\myfolder\php\script.php

What is the best method to merge two PHP objects?

You could create another object that dispatches calls to magic methods to the underlying objects. Here's how you'd handle __get, but to get it working fully you'd have to override all the relevant magic methods. You'll probably find syntax errors since I just entered it off the top of my head.

class Compositor {
  private $obj_a;
  private $obj_b;

  public function __construct($obj_a, $obj_b) {
    $this->obj_a = $obj_a;
    $this->obj_b = $obj_b;
  }

  public function __get($attrib_name) {
    if ($this->obj_a->$attrib_name) {
       return $this->obj_a->$attrib_name;
    } else {
       return $this->obj_b->$attrib_name;
    }
  }
}

Good luck.

Overlapping Views in Android

Yes, that is possible. The challenge, however, is to do their layout properly. The easiest way to do it would be to have an AbsoluteLayout and then put the two images where you want them to be. You don't need to do anything special for the transparent png except having it added later to the layout.

What is private bytes, virtual bytes, working set?

The short answer to this question is that none of these values are a reliable indicator of how much memory an executable is actually using, and none of them are really appropriate for debugging a memory leak.

Private Bytes refer to the amount of memory that the process executable has asked for - not necessarily the amount it is actually using. They are "private" because they (usually) exclude memory-mapped files (i.e. shared DLLs). But - here's the catch - they don't necessarily exclude memory allocated by those files. There is no way to tell whether a change in private bytes was due to the executable itself, or due to a linked library. Private bytes are also not exclusively physical memory; they can be paged to disk or in the standby page list (i.e. no longer in use, but not paged yet either).

Working Set refers to the total physical memory (RAM) used by the process. However, unlike private bytes, this also includes memory-mapped files and various other resources, so it's an even less accurate measurement than the private bytes. This is the same value that gets reported in Task Manager's "Mem Usage" and has been the source of endless amounts of confusion in recent years. Memory in the Working Set is "physical" in the sense that it can be addressed without a page fault; however, the standby page list is also still physically in memory but not reported in the Working Set, and this is why you might see the "Mem Usage" suddenly drop when you minimize an application.

Virtual Bytes are the total virtual address space occupied by the entire process. This is like the working set, in the sense that it includes memory-mapped files (shared DLLs), but it also includes data in the standby list and data that has already been paged out and is sitting in a pagefile on disk somewhere. The total virtual bytes used by every process on a system under heavy load will add up to significantly more memory than the machine actually has.

So the relationships are:

  • Private Bytes are what your app has actually allocated, but include pagefile usage;
  • Working Set is the non-paged Private Bytes plus memory-mapped files;
  • Virtual Bytes are the Working Set plus paged Private Bytes and standby list.

There's another problem here; just as shared libraries can allocate memory inside your application module, leading to potential false positives reported in your app's Private Bytes, your application may also end up allocating memory inside the shared modules, leading to false negatives. That means it's actually possible for your application to have a memory leak that never manifests itself in the Private Bytes at all. Unlikely, but possible.

Private Bytes are a reasonable approximation of the amount of memory your executable is using and can be used to help narrow down a list of potential candidates for a memory leak; if you see the number growing and growing constantly and endlessly, you would want to check that process for a leak. This cannot, however, prove that there is or is not a leak.

One of the most effective tools for detecting/correcting memory leaks in Windows is actually Visual Studio (link goes to page on using VS for memory leaks, not the product page). Rational Purify is another possibility. Microsoft also has a more general best practices document on this subject. There are more tools listed in this previous question.

I hope this clears a few things up! Tracking down memory leaks is one of the most difficult things to do in debugging. Good luck.

How to set environment variables from within package.json?

For a larger set of environment variables or when you want to reuse them you can use env-cmd.

./.env file:

# This is a comment
ENV1=THANKS
ENV2=FOR ALL
ENV3=THE FISH

./package.json:

{
  "scripts": {
    "test": "env-cmd mocha -R spec"
  }
}

What's the difference between tilde(~) and caret(^) in package.json?

carat ^ include everything greater than a particular version in the same major range.

tilde ~ include everything greater than a particular version in the same minor range.

For example, to specify acceptable version ranges up to 1.0.4, use the following syntax:

  • Patch releases: 1.0 or 1.0.x or ~1.0.4
  • Minor releases: 1 or 1.x or ^1.0.4
  • Major releases: * or x

For more information on semantic versioning syntax, see the npm semver calculator.

npm semantic versions in published packages§

More from npm documentation About semantic versioning

How to get the row number from a datatable?

If you need the index of the item you're working with then using a foreach loop is the wrong method of iterating over the collection. Change the way you're looping so you have the index:

for(int i = 0; i < dt.Rows.Count; i++)
{
    // your index is in i
    var row = dt.Rows[i];
}

Python: convert string from UTF-8 to Latin-1

Can you provide more details about what you are trying to do? In general, if you have a unicode string, you can use encode to convert it into string with appropriate encoding. Eg:

>>> a = u"\u00E1"
>>> type(a)
<type 'unicode'>
>>> a.encode('utf-8')
'\xc3\xa1'
>>> a.encode('latin-1')
'\xe1'

Why would you use Expression<Func<T>> rather than Func<T>?

When you want to treat lambda expressions as expression trees and look inside them instead of executing them. For example, LINQ to SQL gets the expression and converts it to the equivalent SQL statement and submits it to server (rather than executing the lambda).

Conceptually, Expression<Func<T>> is completely different from Func<T>. Func<T> denotes a delegate which is pretty much a pointer to a method and Expression<Func<T>> denotes a tree data structure for a lambda expression. This tree structure describes what a lambda expression does rather than doing the actual thing. It basically holds data about the composition of expressions, variables, method calls, ... (for example it holds information such as this lambda is some constant + some parameter). You can use this description to convert it to an actual method (with Expression.Compile) or do other stuff (like the LINQ to SQL example) with it. The act of treating lambdas as anonymous methods and expression trees is purely a compile time thing.

Func<int> myFunc = () => 10; // similar to: int myAnonMethod() { return 10; }

will effectively compile to an IL method that gets nothing and returns 10.

Expression<Func<int>> myExpression = () => 10;

will be converted to a data structure that describes an expression that gets no parameters and returns the value 10:

Expression vs Func larger image

While they both look the same at compile time, what the compiler generates is totally different.

Selecting Multiple Values from a Dropdown List in Google Spreadsheet

I have found solution at https://www.youtube.com/watch?v=dm4z9l26O0I

You would need to use Tools > Script Editor. Create .gs and .html files there. See example at http://goo.gl/LxGXfU (link can be also found under Youtube video). Just copy

Once you have .gs and .html files in place save them and reload your spreadsheet. You will see "Custom menu" as the last item of your top menu. Select cell you would like to manage and click on this menu item.

During the first time it will ask you to authorize application - go ahead and do this.

Note (1): make sure that your cell has "Data validation" defined before you click on "Custom menu".

Note (2): it appeared that solution works with "List from a range" criteria for Data validation (it does not work with "List of items")

Printing to the console in Google Apps Script?

Just to build on vinnief's hacky solution above, I use MsgBox like this:

Browser.msgBox('BorderoToMatriz', Browser.Buttons.OK_CANCEL);

and it acts kinda like a break point, stops the script and outputs whatever string you need to a pop-up box. I find especially in Sheets, where I have trouble with Logger.log, this provides an adequate workaround most times.

Git - remote: Repository not found

Please find below the working solution for Windows:

  1. Open Control Panel from the Start menu.
  2. Select User Accounts.
  3. Select the "Credential Manager".
  4. Click on "Manage Windows Credentials".
  5. Delete any credentials related to Git or GitHub.
  6. Once you deleted all then try to clone again.

enter image description here

Best way to format if statement with multiple conditions

Other answers explain why the first option is normally the best. But if you have multiple conditions, consider creating a separate function (or property) doing the condition checks in option 1. This makes the code much easier to read, at least when you use good method names.

if(MyChecksAreOk()) { Code to execute }

...

private bool MyChecksAreOk()
{ 
    return ConditionOne && ConditionTwo && ConditionThree;
}

It the conditions only rely on local scope variables, you could make the new function static and pass in everything you need. If there is a mix, pass in the local stuff.

Send POST data on redirect with JavaScript/jQuery?

If you are using jQuery, there is a redirect plugin that works with the POST or GET method. It creates a form with hidden inputs and submits it for you. An example of how to get it working:

$.redirect('demo.php', {'arg1': 'value1', 'arg2': 'value2'});

Note: You can pass the method types GET or POST as an optional third parameter; POST is the default.

how to add key value pair in the JSON object already declared

Hi I add key and value to each object

_x000D_
_x000D_
let persons = [_x000D_
  {_x000D_
    name : "John Doe Sr",_x000D_
    age: 30_x000D_
  },{_x000D_
    name: "John Doe Jr",_x000D_
    age : 5_x000D_
  }_x000D_
]_x000D_
_x000D_
function addKeyValue(obj, key, data){_x000D_
  obj[key] = data;_x000D_
}_x000D_
 _x000D_
_x000D_
let newinfo = persons.map(function(person) {_x000D_
  return addKeyValue(person, 'newKey', 'newValue');_x000D_
});_x000D_
_x000D_
console.log(persons);
_x000D_
_x000D_
_x000D_

How can I obtain the element-wise logical NOT of a pandas Series?

To invert a boolean Series, use ~s:

In [7]: s = pd.Series([True, True, False, True])

In [8]: ~s
Out[8]: 
0    False
1    False
2     True
3    False
dtype: bool

Using Python2.7, NumPy 1.8.0, Pandas 0.13.1:

In [119]: s = pd.Series([True, True, False, True]*10000)

In [10]:  %timeit np.invert(s)
10000 loops, best of 3: 91.8 µs per loop

In [11]: %timeit ~s
10000 loops, best of 3: 73.5 µs per loop

In [12]: %timeit (-s)
10000 loops, best of 3: 73.5 µs per loop

As of Pandas 0.13.0, Series are no longer subclasses of numpy.ndarray; they are now subclasses of pd.NDFrame. This might have something to do with why np.invert(s) is no longer as fast as ~s or -s.

Caveat: timeit results may vary depending on many factors including hardware, compiler, OS, Python, NumPy and Pandas versions.

Check if a string is null or empty in XSLT

By my experience the best way is:

<xsl:when test="not(string(categoryName))">
    <xsl:value-of select="other" />
</xsl:when>
<otherwise>
    <xsl:value-of select="categoryName" />
</otherwise>

"Operation must use an updateable query" error in MS Access

set permission on application directory solve this issue with me

To set this permission, right click on the App_Data folder (or whichever other folder you have put the file in) and select Properties. Look for the Security tab. If you can't see it, you need to go to My Computer, then click Tools and choose Folder Options.... then click the View tab. Scroll to the bottom and uncheck "Use simple file sharing (recommended)". Back to the Security tab, you need to add the relevant account to the Group or User Names box. Click Add.... then click Advanced, then Find Now. The appropriate account should be listed. Double click it to add it to the Group or User Names box, then check the Modify option in the permissions. That's it. You are done.

"Adaptive Server is unavailable or does not exist" error connecting to SQL Server from PHP

After countless hours of frustration I managed to get all working:

odbcinst.ini:

[FreeTDS]
Description = FreeTDS Driver v0.91
Driver = /usr/lib/x86_64-linux-gnu/odbc/libtdsodbc.so
Setup = /usr/lib/x86_64-linux-gnu/odbc/libtdsS.so
fileusage=1
dontdlclose=1
UsageCount=1

odbc.ini:

[test]
Driver = FreeTDS
Description = My Test Server
Trace = No
#TraceFile = /tmp/sql.log
ServerName = mssql
#Port = 1433
instance = SQLEXPRESS
Database = usedbname
TDS_Version = 4.2

FreeTDS.conf:

[mssql]
host = hostnameOrIP
instance = SQLEXPRESS
#Port = 1433
tds version = 4.2

First test connection (mssql is a section name from freetds.conf):

tsql -S mssql -U username -P password

You must see some settings but no errors and only a 1> prompt. Use quit to exit.

Then let's test DSN/FreeTDS (test is a section name from odbc.ini; -v means verbose):

isql -v test username password -v

You must see message Connected!

How do I go about adding an image into a java project with eclipse?

You can resave the image and literally find the src file of your project and add it to that when you save. For me I had to go to netbeans and found my project and when that comes up it had 3 files src was the last. Don't click on any of them just save your pic there. That should work. Now resizing it may be a different issue and one I'm working on now lol

Selecting fields from JSON output

Assuming you are dealing with a JSON-string in the input, you can parse it using the json package, see the documentation.

In the specific example you posted you would need

x = json.loads("""{
 "accountWide": true,
 "criteria": [
     {
         "description": "some description",
         "id": 7553,
         "max": 1,
         "orderIndex": 0
     }
  ]
 }""")
description = x['criteria'][0]['description']
id = x['criteria'][0]['id']
max = x['criteria'][0]['max']

How to use sed to replace only the first occurrence in a file?

POSIXly (also valid in sed), Only one regex used, need memory only for one line (as usual):

sed '/\(#include\).*/!b;//{h;s//\1 "newfile.h"/;G};:1;n;b1'

Explained:

sed '
/\(#include\).*/!b          # Only one regex used. On lines not matching
                            # the text  `#include` **yet**,
                            # branch to end, cause the default print. Re-start.
//{                         # On first line matching previous regex.
    h                       # hold the line.
    s//\1 "newfile.h"/      # append ` "newfile.h"` to the `#include` matched.
    G                       # append a newline.
  }                         # end of replacement.
:1                          # Once **one** replacement got done (the first match)
n                           # Loop continually reading a line each time
b1                          # and printing it by default.
'                           # end of sed script.

Entity Framework Query for inner join

In case anyone's interested in the Method syntax, if you have a navigation property, it's way easy:

db.Services.Where(s=>s.ServiceAssignment.LocationId == 1);

If you don't, unless there's some Join() override I'm unaware of, I think it looks pretty gnarly (and I'm a Method syntax purist):

db.Services.Join(db.ServiceAssignments, 
     s => s.Id,
     sa => sa.ServiceId, 
     (s, sa) => new {service = s, asgnmt = sa})
.Where(ssa => ssa.asgnmt.LocationId == 1)
.Select(ssa => ssa.service);

How to create a file in Linux from terminal window?

Depending on what you want the file to contain:

  • touch /path/to/file for an empty file
  • somecommand > /path/to/file for a file containing the output of some command.

      eg: grep --help > randomtext.txt
          echo "This is some text" > randomtext.txt
    
  • nano /path/to/file or vi /path/to/file (or any other editor emacs,gedit etc)
    It either opens the existing one for editing or creates & opens the empty file to enter, if it doesn't exist


Create the file using cat

$ cat > myfile.txt

Now, just type whatever you want in the file:

Hello World!

CTRL-D to save and exit


There are several possible solutions:

Create an empty file

touch file

>file

echo -n > file

printf '' > file

The echo version will work only if your version of echo supports the -n switch to suppress newlines. This is a non-standard addition. The other examples will all work in a POSIX shell.

Create a file containing a newline and nothing else

echo '' > file

printf '\n' > file

This is a valid "text file" because it ends in a newline.

Write text into a file

"$EDITOR" file

echo 'text' > file

cat > file <<END \
text
END

printf 'text\n' > file

These are equivalent. The $EDITOR command assumes that you have an interactive text editor defined in the EDITOR environment variable and that you interactively enter equivalent text. The cat version presumes a literal newline after the \ and after each other line. Other than that these will all work in a POSIX shell.

Of course there are many other methods of writing and creating files, too.

The simplest way to resize an UIImage?

I've discovered that it's difficult to find an answer that you can use out-of-the box in your Swift 3 project. The main problem of other answers that they don't honor the alpha-channel of the image. Here is the technique that I'm using in my projects.

extension UIImage {

    func scaledToFit(toSize newSize: CGSize) -> UIImage {
        if (size.width < newSize.width && size.height < newSize.height) {
            return copy() as! UIImage
        }

        let widthScale = newSize.width / size.width
        let heightScale = newSize.height / size.height

        let scaleFactor = widthScale < heightScale ? widthScale : heightScale
        let scaledSize = CGSize(width: size.width * scaleFactor, height: size.height * scaleFactor)

        return self.scaled(toSize: scaledSize, in: CGRect(x: 0.0, y: 0.0, width: scaledSize.width, height: scaledSize.height))
    }

    func scaled(toSize newSize: CGSize, in rect: CGRect) -> UIImage {
        if UIScreen.main.scale == 2.0 {
            UIGraphicsBeginImageContextWithOptions(newSize, !hasAlphaChannel, 2.0)
        }
        else {
            UIGraphicsBeginImageContext(newSize)
        }

        draw(in: rect)
        let newImage = UIGraphicsGetImageFromCurrentImageContext()
        UIGraphicsEndImageContext()

        return newImage ?? UIImage()
    }

    var hasAlphaChannel: Bool {
        guard let alpha = cgImage?.alphaInfo else {
            return false
        }
        return alpha == CGImageAlphaInfo.first ||
            alpha == CGImageAlphaInfo.last ||
            alpha == CGImageAlphaInfo.premultipliedFirst ||
            alpha == CGImageAlphaInfo.premultipliedLast
    }
}

Example of usage:

override func viewDidLoad() {
    super.viewDidLoad()

    let size = CGSize(width: 14.0, height: 14.0)
    if let image = UIImage(named: "barbell")?.scaledToFit(toSize: size) {
        let imageView = UIImageView(image: image)
        imageView.center = CGPoint(x: 100, y: 100)
        view.addSubview(imageView)
    }
}

This code is a rewrite of Apple's extension with added support for images with and without alpha channel.

As a further reading I recommend checking this article for different image resizing techniques. Current approach offers decent performance, it operates high-level APIs and easy to understand. I recommend sticking to it unless you find that image resizing is a bottleneck in your performance.

ImportError: No module named apiclient.discovery

If none of the above solutions work for you, consider if you might have installed python through Anaconda. If this is the case then installing the google API library with conda might fix it.

Run:

python --version

If you get something like

Python 3.6.4 :: Anaconda, Inc.

Then try:

conda install google-api-python-client

As bgoodr has pointed out in a comment you might need to specify the channel (think repository) to get the google API library. At the time of writing this means running the command:

conda install -c conda-forge google-api-python-client

See more at https://anaconda.org/conda-forge/google-api-python-client

vagrant login as root by default

Note: Only use this method for local development, it's not secure. You can setup password and ssh config while provisioning the box. For example with debian/stretch64 box this is my provision script:

config.vm.provision "shell", inline: <<-SHELL
    echo -e "vagrant\nvagrant" | passwd root
    echo "PermitRootLogin yes" >> /etc/ssh/sshd_config
    sed -in 's/PasswordAuthentication no/PasswordAuthentication yes/g' /etc/ssh/sshd_config
    service ssh restart
SHELL

This will set root password to vagrant and permit root login with password. If you are using private_network say with ip address 192.168.10.37 then you can ssh with ssh [email protected]

You may need to change that echo and sed commands depending on the default sshd_config file.

how to convert milliseconds to date format in android?

public static String toDateStr(long milliseconds, String format)
{
    Date date = new Date(milliseconds);
    SimpleDateFormat formatter = new SimpleDateFormat(format, Locale.US);
    return formatter.format(date);
}

LINQ: "contains" and a Lambda query

I'm not sure precisely what you're looking for, but this program:

    public class Building
    {
        public enum StatusType
        {
            open,
            closed,
            weird,
        };

        public string Name { get; set; }
        public StatusType Status { get; set; }
    }

    public static List <Building> buildingList = new List<Building> ()
    {
        new Building () { Name = "one", Status = Building.StatusType.open },
        new Building () { Name = "two", Status = Building.StatusType.closed },
        new Building () { Name = "three", Status = Building.StatusType.weird },

        new Building () { Name = "four", Status = Building.StatusType.open },
        new Building () { Name = "five", Status = Building.StatusType.closed },
        new Building () { Name = "six", Status = Building.StatusType.weird },
    };

    static void Main (string [] args)
    {
        var statusList = new List<Building.StatusType> () { Building.StatusType.open, Building.StatusType.closed };

        var q = from building in buildingList
                where statusList.Contains (building.Status)
                select building;

        foreach ( var b in q )
            Console.WriteLine ("{0}: {1}", b.Name, b.Status);
    }

produces the expected output:

one: open
two: closed
four: open
five: closed

This program compares a string representation of the enum and produces the same output:

    public class Building
    {
        public enum StatusType
        {
            open,
            closed,
            weird,
        };

        public string Name { get; set; }
        public string Status { get; set; }
    }

    public static List <Building> buildingList = new List<Building> ()
    {
        new Building () { Name = "one", Status = "open" },
        new Building () { Name = "two", Status = "closed" },
        new Building () { Name = "three", Status = "weird" },

        new Building () { Name = "four", Status = "open" },
        new Building () { Name = "five", Status = "closed" },
        new Building () { Name = "six", Status = "weird" },
    };

    static void Main (string [] args)
    {
        var statusList = new List<Building.StatusType> () { Building.StatusType.open, Building.StatusType.closed };
        var statusStringList = statusList.ConvertAll <string> (st => st.ToString ());

        var q = from building in buildingList
                where statusStringList.Contains (building.Status)
                select building;

        foreach ( var b in q )
            Console.WriteLine ("{0}: {1}", b.Name, b.Status);

        Console.ReadKey ();
    }

I created this extension method to convert one IEnumerable to another, but I'm not sure how efficient it is; it may just create a list behind the scenes.

public static IEnumerable <TResult> ConvertEach (IEnumerable <TSource> sources, Func <TSource,TResult> convert)
{
    foreach ( TSource source in sources )
        yield return convert (source);
}

Then you can change the where clause to:

where statusList.ConvertEach <string> (status => status.GetCharValue()).
    Contains (v.Status)

and skip creating the List<string> with ConvertAll () at the beginning.

How do I check two or more conditions in one <c:if>?

This look like a duplicate of JSTL conditional check.

The error is having the && outside the expression. Instead use

<c:if test="${ISAJAX == 0 && ISDATE == 0}">

pandas: merge (join) two data frames on multiple columns

Another way of doing this: new_df = A_df.merge(B_df, left_on=['A_c1','c2'], right_on = ['B_c1','c2'], how='left')

How to execute .sql script file using JDBC

Just read it and then use the preparedstatement with the full sql-file in it.

(If I remember good)

ADD: You can also read and split on ";" and than execute them all in a loop. Do not forget the comments and add again the ";"

How to count items in JSON data

import json

json_data = json.dumps({
  "result":[
    {
      "run":[
        {
          "action":"stop"
        },
        {
          "action":"start"
        },
        {
          "action":"start"
        }
      ],
      "find": "true"
    }
  ]
})

item_dict = json.loads(json_data)
print len(item_dict['result'][0]['run'])

Convert it in dict.

php: Get html source code with cURL

$curl = curl_init($url);
curl_setopt($curl, CURLOPT_RETURNTRANSFER, 1);
$result = curl_exec($curl);
curl_close($curl);

Source: http://www.christianschenk.org/blog/php-curl-allow-url-fopen/

JavaScript: Is there a way to get Chrome to break on all errors?

Edit: The original link I answered with is now invalid.The newer URL would be https://developers.google.com/web/tools/chrome-devtools/javascript/add-breakpoints#exceptions as of 2016-11-11.

I realize this question has an answer, but it's no longer accurate. Use the link above ^


(link replaced by edited above) - you can now set it to break on all exceptions or just unhandled ones. (Note that you need to be in the Sources tab to see the button.)

Chrome's also added some other really useful breakpoint capabilities now, such as breaking on DOM changes or network events.

Normally I wouldn't re-answer a question, but I had the same question myself, and I found this now-wrong answer, so I figured I'd put this information in here for people who came along later in searching. :)

How to get a user's time zone?

You can use below code for getting current time zone

 func getCurrentTimeZone() -> String{

         return TimeZone.current.identifier

  }

  let currentTimeZone = getCurrentTimeZone()
   print(currentTimeZone)

How to change Rails 3 server default port in develoment?

I like to append the following to config/boot.rb:

require 'rails/commands/server'

module Rails
  class Server
    alias :default_options_alias :default_options
    def default_options
      default_options_alias.merge!(:Port => 3333)
    end    
  end
end

Sorting std::map using value

You can't sort a std::map this way, because a the entries in the map are sorted by the key. If you want to sort by value, you need to create a new std::map with swapped key and value.

map<long, double> testMap;
map<double, long> testMap2;

// Insert values from testMap to testMap2
// The values in testMap2 are sorted by the double value

Remember that the double keys need to be unique in testMap2 or use std::multimap.

When to use Hadoop, HBase, Hive and Pig?

Hadoop is a a framework that allows for the distributed processing of large data sets across clusters of computers using simple programming models.

There are four main modules in Hadoop.

  1. Hadoop Common: The common utilities that support the other Hadoop modules.

  2. Hadoop Distributed File System (HDFS™): A distributed file system that provides high-throughput access to application data.

  3. Hadoop YARN: A framework for job scheduling and cluster resource management.

  4. Hadoop MapReduce: A YARN-based system for parallel processing of large data sets.

Before going further, Let's note that we have three different types of data.

  • Structured: Structured data has strong schema and schema will be checked during write & read operation. e.g. Data in RDBMS systems like Oracle, MySQL Server etc.

  • Unstructured: Data does not have any structure and it can be any form - Web server logs, E-Mail, Images etc.

  • Semi-structured: Data is not strictly structured but have some structure. e.g. XML files.

Depending on type of data to be processed, we have to choose right technology.

Some more projects, which are part of Hadoop:

  • HBase™: A scalable, distributed database that supports structured data storage for large tables.

  • Hive™: A data warehouse infrastructure that provides data summarization and ad-hoc querying.

  • Pig™: A high-level data-flow language and execution framework for parallel computation.

Hive Vs PIG comparison can be found at this article and my other post at this SE question.

HBASE won't replace Map Reduce. HBase is scalable distributed database & Map Reduce is programming model for distributed processing of data. Map Reduce may act on data in HBASE in processing.

You can use HIVE/HBASE for structured/semi-structured data and process it with Hadoop Map Reduce

You can use SQOOP to import structured data from traditional RDBMS database Oracle, SQL Server etc and process it with Hadoop Map Reduce

You can use FLUME for processing Un-structured data and process with Hadoop Map Reduce

Have a look at: Hadoop Use Cases.

Hive should be used for analytical querying of data collected over a period of time. e.g Calculate trends, summarize website logs but it can't be used for real time queries.

HBase fits for real-time querying of Big Data. Facebook use it for messaging and real-time analytics.

PIG can be used to construct dataflows, run a scheduled jobs, crunch big volumes of data, aggregate/summarize it and store into relation database systems. Good for ad-hoc analysis.

Hive can be used for ad-hoc data analysis but it can't support all un-structured data formats unlike PIG.

SQLPLUS error:ORA-12504: TNS:listener was not given the SERVICE_NAME in CONNECT_DATA

You're missing service name:

 SQL> connect username/password@hostname:port/SERVICENAME

EDIT

If you can connect to the database from other computer try running there:

select sys_context('USERENV','SERVICE_NAME') from dual

and

select sys_context('USERENV','SID') from dual

Reliable and fast FFT in Java

Late to the party - here as a pure java solution for those when JNI is not an option.JTransforms

Install NuGet via PowerShell script

Here's a short PowerShell script to do what you probably expect:

$sourceNugetExe = "https://dist.nuget.org/win-x86-commandline/latest/nuget.exe"
$targetNugetExe = "$rootPath\nuget.exe"
Invoke-WebRequest $sourceNugetExe -OutFile $targetNugetExe
Set-Alias nuget $targetNugetExe -Scope Global -Verbose

Note that Invoke-WebRequest cmdlet arrived with PowerShell v3.0. This article gives the idea.

Write to .txt file?

Well, you need to first get a good book on C and understand the language.

FILE *fp;
fp = fopen("c:\\test.txt", "wb");
if(fp == null)
   return;
char x[10]="ABCDEFGHIJ";
fwrite(x, sizeof(x[0]), sizeof(x)/sizeof(x[0]), fp);
fclose(fp);

Checkout old commit and make it a new commit

The other answers so far create new commits that undo what is in older commits. It is possible to go back and "change history" as it were, but this can be a bit dangerous. You should only do this if the commit you're changing has not been pushed to other repositories.

The command you're looking for is git rebase --interactive

If you want to change HEAD~3, the command you want to issue is git rebase --interactive HEAD~4. This will open a text editor and allow you to specify which commits you want to change.

Practice on a different repository before you try this with something important. The man pages should give you all the rest of the information you need.

python ValueError: invalid literal for float()

I would all but guarantee that the issue is some sort of non-printing character that's present in the value you pulled off your socket. It looks like you're using Python 2.x, in which case you can check for them with this:

print repr(temp)

You'll likely see something in there that's escaped in the form \x00. These non-printing characters don't show up when you print directly to the console, but their presence is enough to negatively impact the parsing of a string value into a float.

-- Edited for question changes --

It turns this is partly accurate for your issue - the root cause however appears to be that you're reading more information than you expect from your socket or otherwise receiving multiple values. You could do something like

map(float, temp.strip().split('\r\n'))

In order to convert each of the values, but if your function is supposed to return a single float value this is likely to cause confusion. Anyway, the issue certainly revolves around the presence of characters you did not expect to see in the value you retrieved from your socket.

How to get element by class name?

Another option is to use querySelector('.foo') or querySelectorAll('.foo') which have broader browser support than getElementsByClassName.

http://caniuse.com/#feat=queryselector

http://caniuse.com/#feat=getelementsbyclassname

Output to the same line overwriting previous output?

I found that for a simple print statement in python 2.7, just put a comma at the end after your '\r'.

print os.path.getsize(file_name)/1024, 'KB / ', size, 'KB downloaded!\r',

This is shorter than other non-python 3 solutions, but also more difficult to maintain.

How to set a Default Route (To an Area) in MVC

even it was answered already - this is the short syntax (ASP.net 3, 4, 5):

routes.MapRoute("redirect all other requests", "{*url}",
    new {
        controller = "UnderConstruction",
        action = "Index"
        }).DataTokens = new RouteValueDictionary(new { area = "Shop" });

How to send emails from my Android application?

Other solution can be

Intent emailIntent = new Intent(android.content.Intent.ACTION_SEND);
emailIntent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
emailIntent.setType("plain/text");
emailIntent.setClassName("com.google.android.gm", "com.google.android.gm.ComposeActivityGmail");
emailIntent.putExtra(android.content.Intent.EXTRA_EMAIL, new String[]{"[email protected]"});
emailIntent.putExtra(android.content.Intent.EXTRA_SUBJECT, "Yo");
emailIntent.putExtra(android.content.Intent.EXTRA_TEXT, "Hi");
startActivity(emailIntent);

Assuming most of the android device has GMail app already installed.

Angularjs autocomplete from $http

I made an autocomplete directive and uploaded it to GitHub. It should also be able to handle data from an HTTP-Request.

Here's the demo: http://justgoscha.github.io/allmighty-autocomplete/ And here the documentation and repository: https://github.com/JustGoscha/allmighty-autocomplete

So basically you have to return a promise when you want to get data from an HTTP request, that gets resolved when the data is loaded. Therefore you have to inject the $qservice/directive/controller where you issue your HTTP Request.

Example:

function getMyHttpData(){
  var deferred = $q.defer();
  $http.jsonp(request).success(function(data){
    // the promise gets resolved with the data from HTTP
    deferred.resolve(data);
  });
  // return the promise
  return deferred.promise;
}

I hope this helps.

Eclipse error: R cannot be resolved to a variable

I'm not posting this as an answer but a confirmation to Paresh's accepted answer. I recently updated SDK tools to Revision 22 and I noticed my code changes was not being affective on the device i'm testing at all. Such as the url I was using, I was getting errors for connection time out regarding the url I was "previously" using. Therefore I cleaned the project and built again only to find out that autogenerated R.java file is missing.

After reading Paresh's answer and checking what's going on with my sdk manager this is what I saw: enter image description here

SDK Build-tools 17 was not installed and there was already a new update to SDK tools even though it does not mention any change related to this problem in the changelog, this update brought back my R.java file and the related problems were gone after an eclipse restart and final clean/rebuild on the project.

window.open with target "_blank" in Chrome

As Dennis says, you can't control how the browser chooses to handle target=_blank.

If you're wondering about the inconsistent behavior, probably it's pop-up blocking. Many browsers will forbid new windows from being opened apropos of nothing, but will allow new windows to be spawned as the eventual result of a mouse-click event.

Unable to set variables in bash script

Five problems:

  1. Don't put a space before or after the equal sign.
  2. Use "$(...)" to get the output of a command as text.
  3. [ is a command. Put a space between it and the arguments.
  4. Commands are case-sensitive. You want echo.
  5. Use double quotes around variables. rm "$folderToBeMoved"

How can I style the border and title bar of a window in WPF?

Those are "non-client" areas and are controlled by Windows. Here is the MSDN docs on the subject (the pertinent info is at the top).

Basically, you set your Window's WindowStyle="None", then build your own window interface. (similar question on SO)

Android: why is there no maxHeight for a View?

As mentioned above, ConstraintLayout offers maximum height for its children via:

app:layout_constraintHeight_max="300dp"
app:layout_constrainedHeight="true"

Besides, if maximum height for one ConstraintLayout's child is uncertain until App running, there still has a way to make this child automatically adapt a mutable height no matter where it was placed in the vertical chain.

For example, we need to show a bottom dialog with a mutable header TextView, a mutable ScrollView and a mutable footer TextView. The dialog's max height is 320dp,when total height not reach 320dp ScrollView act as wrap_content, when total height exceed ScrollView act as "maxHeight=320dp - header height - footer height".

We can achieve this just through xml layout file:

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="320dp">

    <TextView
        android:id="@+id/tv_header"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:background="@color/black_10"
        android:gravity="center"
        android:padding="10dp"
        app:layout_constraintBottom_toTopOf="@id/scroll_view"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintVertical_bias="1"
        app:layout_constraintVertical_chainStyle="packed"
        tools:text="header" />

    <ScrollView
        android:id="@+id/scroll_view"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:background="@color/black_30"
        app:layout_constrainedHeight="true"
        app:layout_constraintBottom_toTopOf="@id/tv_footer"
        app:layout_constraintHeight_max="300dp"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@id/tv_header">

        <LinearLayout
            android:id="@+id/ll_container"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:orientation="vertical">

            <TextView
                android:id="@+id/tv_sub1"
                android:layout_width="match_parent"
                android:layout_height="160dp"
                android:gravity="center"
                android:textColor="@color/orange_light"
                tools:text="sub1" />

            <TextView
                android:id="@+id/tv_sub2"
                android:layout_width="match_parent"
                android:layout_height="160dp"
                android:gravity="center"
                android:textColor="@color/orange_light"
                tools:text="sub2" />

        </LinearLayout>
    </ScrollView>

    <TextView
        android:id="@+id/tv_footer"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:background="@color/black_50"
        android:gravity="center"
        android:padding="10dp"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@id/scroll_view"
        tools:text="footer" />
</android.support.constraint.ConstraintLayout>

Most import code is short:

app:layout_constraintVertical_bias="1"
app:layout_constraintVertical_chainStyle="packed"

app:layout_constrainedHeight="true"

Horizontal maxWidth usage is quite the same.

Adding click event listener to elements with the same class

You should use querySelectorAll. It returns NodeList, however querySelector returns only the first found element:

var deleteLink = document.querySelectorAll('.delete');

Then you would loop:

for (var i = 0; i < deleteLink.length; i++) {
    deleteLink[i].addEventListener('click', function(event) {
        if (!confirm("sure u want to delete " + this.title)) {
            event.preventDefault();
        }
    });
}

Also you should preventDefault only if confirm === false.

It's also worth noting that return false/true is only useful for event handlers bound with onclick = function() {...}. For addEventListening you should use event.preventDefault().

Demo: http://jsfiddle.net/Rc7jL/3/


ES6 version

You can make it a little cleaner (and safer closure-in-loop wise) by using Array.prototype.forEach iteration instead of for-loop:

var deleteLinks = document.querySelectorAll('.delete');

Array.from(deleteLinks).forEach(link => {
    link.addEventListener('click', function(event) {
        if (!confirm(`sure u want to delete ${this.title}`)) {
            event.preventDefault();
        }
    });
});

Example above uses Array.from and template strings from ES2015 standard.

Create Windows service from executable

Extending (Kevin Tong) answer.

Step 1: Download & Unzip nssm-2.24.zip

Step 2: From command line type:

C:\> nssm.exe install [servicename]

it will open GUI as below (the example is UT2003 server), then simply browse it to: yourapplication.exe

enter image description here

More information on: https://nssm.cc/usage

javascript, is there an isObject function like isArray?

You can use typeof operator.

if( (typeof A === "object" || typeof A === 'function') && (A !== null) )
{
    alert("A is object");
}

Note that because typeof new Number(1) === 'object' while typeof Number(1) === 'number'; the first syntax should be avoided.

vertical-align: middle doesn't work

Vertical align doesn't quite work the way you want it to. See: http://phrogz.net/css/vertical-align/index.html

This isn't pretty, but it WILL do what you want: Vertical align behaves as expected only when used in a table cell.

http://jsfiddle.net/e8ESb/6/

There are other alternatives: You can declare things as tables or table cells within CSS to make them behave as desired, for example. Margins and positioning can sometimes be played with to get the same effect. None of the solutions are terrible pretty, though.

How to add bootstrap to an angular-cli project

For Adding Bootstrap and Jquery both

npm install bootstrap@3 jquery --save

after running this command, please go ahead and check your node_modules folder you should be able to see bootstrap and jquery added into it.

Creating an iframe with given HTML dynamically

Thanks for your great question, this has caught me out a few times. When using dataURI HTML source, I find that I have to define a complete HTML document.

See below a modified example.

var html = '<html><head></head><body>Foo</body></html>';
var iframe = document.createElement('iframe');
iframe.src = 'data:text/html;charset=utf-8,' + encodeURI(html);

take note of the html content wrapped with <html> tags and the iframe.src string.

The iframe element needs to be added to the DOM tree to be parsed.

document.body.appendChild(iframe);

You will not be able to inspect the iframe.contentDocument unless you disable-web-security on your browser. You'll get a message

DOMException: Failed to read the 'contentDocument' property from 'HTMLIFrameElement': Blocked a frame with origin "http://localhost:7357" from accessing a cross-origin frame.

js window.open then print()

function printCrossword(printContainer) {
    var DocumentContainer = getElement(printContainer);
    var WindowObject = window.open('', "PrintWindow", "width=5,height=5,top=200,left=200,toolbars=no,scrollbars=no,status=no,resizable=no");
    WindowObject.document.writeln(DocumentContainer.innerHTML);
    WindowObject.document.close();
    WindowObject.focus();
    WindowObject.print();
    WindowObject.close();
}

How to convert std::string to LPCSTR?

The MultiByteToWideChar answer that Charles Bailey gave is the correct one. Because LPCWSTR is just a typedef for const WCHAR*, widestr in the example code there can be used wherever a LPWSTR is expected or where a LPCWSTR is expected.

One minor tweak would be to use std::vector<WCHAR> instead of a manually managed array:

// using vector, buffer is deallocated when function ends
std::vector<WCHAR> widestr(bufferlen + 1);

::MultiByteToWideChar(CP_ACP, 0, instr.c_str(), instr.size(), &widestr[0], bufferlen);

// Ensure wide string is null terminated
widestr[bufferlen] = 0;

// no need to delete; handled by vector

Also, if you need to work with wide strings to start with, you can use std::wstring instead of std::string. If you want to work with the Windows TCHAR type, you can use std::basic_string<TCHAR>. Converting from std::wstring to LPCWSTR or from std::basic_string<TCHAR> to LPCTSTR is just a matter of calling c_str. It's when you're changing between ANSI and UTF-16 characters that MultiByteToWideChar (and its inverse WideCharToMultiByte) comes into the picture.

Creating a list of pairs in java

Sounds like you need to create your own pair class (see discussion here). Then make a List of that pair class you created

No resource found that matches the given name '@style/ Theme.Holo.Light.DarkActionBar'

If you use android studio, this might be useful for you.

I had a similar problem and i solved it by changing the skd path from the default C:\Program Files (x86)\Android\android-studio\sdk to C:\Program Files (x86)\Android\android-sdk .

It seems the problem came from the compiler version (gradle sets it automatically to the highest one available in the sdk folder) which doesn't support this theme, and since android studio had only the api 7 in its sdk folder, it gave me this error.

For more information on how to change Android sdk path in Android Studio: Android Studio - How to Change Android SDK Path

Access to build environment variables from a groovy script in a Jenkins build step (Windows)

The Scriptler Groovy script doesn't seem to get all the environment variables of the build. But what you can do is force them in as parameters to the script:

  1. When you add the Scriptler build step into your job, select the option "Define script parameters"

  2. Add a parameter for each environment variable you want to pass in. For example "Name: JOB_NAME", "Value: $JOB_NAME". The value will get expanded from the Jenkins build environment using '$envName' type variables, most fields in the job configuration settings support this sort of expansion from my experience.

  3. In your script, you should have a variable with the same name as the parameter, so you can access the parameters with something like:

    println "JOB_NAME = $JOB_NAME"

I haven't used Sciptler myself apart from some experimentation, but your question posed an interesting problem. I hope this helps!

How to stop execution after a certain time in Java?

long start = System.currentTimeMillis();
long end = start + 60*1000; // 60 seconds * 1000 ms/sec
while (System.currentTimeMillis() < end)
{
    // run
}

Palindrome check in Javascript

I thought I'd share my own solution:

_x000D_
_x000D_
function palindrome(string){_x000D_
    var reverseString = '';_x000D_
    for(var k in string){_x000D_
       reverseString += string[(string.length - k) - 1];_x000D_
    }_x000D_
  if(string === reverseString){_x000D_
    console.log('Hey there palindrome');_x000D_
  }else{_x000D_
    console.log('You are not a palindrome');_x000D_
  }_x000D_
}_x000D_
palindrome('ana');
_x000D_
_x000D_
_x000D_

Hope will help someone.

Autocompletion of @author in Intellij

You can work around that via a Live Template. Go to Settings -> Live Template, click the "Add"-Button (green plus on the right).

In the "Abbreviation" field, enter the string that should activate the template (e.g. @a), and in the "Template Text" area enter the string to complete (e.g. @author - My Name). Set the "Applicable context" to Java (Comments only maybe) and set a key to complete (on the right).

I tested it and it works fine, however IntelliJ seems to prefer the inbuild templates, so "@a + Tab" only completes "author". Setting the completion key to Space worked however.

To change the user name that is automatically inserted via the File Templates (when creating a class for example), can be changed by adding

-Duser.name=Your name

to the idea.exe.vmoptions or idea64.exe.vmoptions (depending on your version) in the IntelliJ/bin directory.

enter image description here

Restart IntelliJ

Node / Express: EADDRINUSE, Address already in use - Kill server

Reasons for this issues are:

  1. Any one application may be running on this port like Skype.
  2. Node may have crashed and port may not have been freed.
  3. You may have tried to start server more than one. To solve this problem, one can maintain a boolean to check whether server have been started or not. It should be started only if boolean return false or undefined;

Start an activity from a fragment

If you are using getActivity() then you have to make sure that the calling activity is added already. If activity has not been added in such case so you may get null when you call getActivity()

in such cases getContext() is safe

then the code for starting the activity will be slightly changed like,

Intent intent = new Intent(getContext(), mFragmentFavorite.class);
startActivity(intent);

Activity, Service and Application extends ContextWrapper class so you can use this or getContext() or getApplicationContext() in the place of first argument.

Visually managing MongoDB documents and collections

Here are some popular MongoDB GUI administration tools:

Open source

  • dbKoda - cross-platform, tabbed editor with auto-complete, syntax highlighting and code formatting (plus auto-save, something Studio 3T doesn't support), visual tools (explain plan, real-time performance dashboard, query and aggregation pipeline builder), profiling manager, storage analyzer, index advisor, convert MongoDB commands to Node.js syntax etc. Lacks in-place document editing and the ability to switch themes.

    dbKoda screenshot

  • Nosqlclient - multiple shell output tabs, autocomplete, schema analyzer, index management, user/role management, live monitoring, and other features. Electron/Meteor.js-based, actively developed on GitHub.

  • adminMongo - web-based or Electron app. Supports server monitoring and document editing.

Closed source

  • NoSQLBoosterfull-featured shell-centric cross-platform GUI tool for MongoDB v2.2-4. Free, Personal, and Commercial editions (feature comparison matrix).
  • MongoDB Compass – provides a graphical user interface that allows you to visualize your schema and perform ad-hoc find queries against the database – all with zero knowledge of MongoDB's query language. Developed by MongoDB, Inc. No update queries or access to the shell.
  • Studio 3T, formerly MongoChef – a multi-platform in-place data browser and editor desktop GUI for MongoDB (Core version is free for personal and non-commercial use). Last commit: 2017-Jul-24
  • Robo 3T – acquired by Studio 3T. A shell-centric cross-platform open source MongoDB management tool. Shell-related features only, e.g. multiple shells and results, autocomplete. No export/ import or other features are mentioned. Last commit: 2017-Jul-04

  • HumongouS.io – web-based interface with CRUD features, a chart builder and some collaboration capabilities. 14-day trial.

  • Database Master – a Windows based MongoDB Management Studio, supports also RDBMS. (not free)
  • SlamData - an open source web-based user-interface that allows you to upload and download data, run queries, build charts, explore data.

Abandoned projects

  • RockMongo – a MongoDB administration tool, written in PHP5. Allegedly the best in the PHP world. Similar to PHPMyAdmin. Last version: 2015-Sept-19
  • Fang of Mongo – a web-based UI built with Django and jQuery. Last commit: 2012-Jan-26, in a forked project.
  • Opricot – a browser-based MongoDB shell written in PHP. Latest version: 2010-Sep-21
  • Futon4Mongo – a clone of the CouchDB Futon web interface for MongoDB. Last commit: 2010-Oct-09
  • MongoVUE – an elegant GUI desktop application for Windows. Free and non-free versions. Latest version: 2014-Jan-20
  • UMongo – a full-featured open-source MongoDB server administration tool for Linux, Windows, Mac; written in Java. Last commit 2014-June
  • Mongo3 – a Ruby/Sinatra-based interface for cluster management. Last commit: Apr 16, 2013

MySQL's now() +1 day

You can use:

NOW() + INTERVAL 1 DAY

If you are only interested in the date, not the date and time then you can use CURDATE instead of NOW:

CURDATE() + INTERVAL 1 DAY

Convert String value format of YYYYMMDDHHMMSS to C# DateTime

class Program
{
    static void Main(string[] args)
    {

        int transactionDate = 20201010;
        int? transactionTime = 210000;

        var agreementDate = DateTime.Today;
        var previousDate = agreementDate.AddDays(-1);

        var agreementHour = 22;
        var agreementMinute = 0;
        var agreementSecond = 0;

        var startDate = new DateTime(previousDate.Year, previousDate.Month, previousDate.Day, agreementHour, agreementMinute, agreementSecond);
        var endDate = new DateTime(agreementDate.Year, agreementDate.Month, agreementDate.Day, agreementHour, agreementMinute, agreementSecond);

        DateTime selectedDate = Convert.ToDateTime(transactionDate.ToString().Substring(6, 2) + "/" + transactionDate.ToString().Substring(4, 2) + "/" + transactionDate.ToString().Substring(0, 4) + " " + string.Format("{0:00:00:00}", transactionTime));

        Console.WriteLine("Selected Date : " + selectedDate.ToString());
        Console.WriteLine("Start Date : " + startDate.ToString());
        Console.WriteLine("End Date : " + endDate.ToString());

        if (selectedDate > startDate && selectedDate <= endDate)
            Console.WriteLine("Between two dates..");
        else if (selectedDate <= startDate)
            Console.WriteLine("Less than or equal to the start date!");
        else if (selectedDate > endDate)
            Console.WriteLine("Greater than end date!");
        else
            Console.WriteLine("Out of date ranges!");
    }
}

Error: unable to verify the first certificate in nodejs

unable to verify the first certificate

The certificate chain is incomplete.

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

Certificate chain

It most likely looks as follows:

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

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

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

Recreate the problem

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

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

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

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

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

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

Solution

You need to complete the certificate chain yourself.

To do that:

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

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

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

1. How do I get intermediate certificate?

Using openssl (comes with Git for Windows).

Save the remote server's certificate details:

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

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

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

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

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

Finally, convert it to .pem:

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

2a. NODE_EXTRA_CERTS

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

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

2b. ca option

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

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

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

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

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

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

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

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

Resources:

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

Compare given date with today

One caution based on my experience, if your purpose only involves date then be careful to include the timestamp. For example, say today is "2016-11-09". Comparison involving timestamp will nullify the logic here. Example,

//  input
$var = "2016-11-09 00:00:00.0";

//  check if date is today or in the future
if ( time() <= strtotime($var) ) 
{
    //  This seems right, but if it's ONLY date you are after
    //  then the code might treat $var as past depending on
    //  the time.
}

The code above seems right, but if it's ONLY the date you want to compare, then, the above code is not the right logic. Why? Because, time() and strtotime() will provide include timestamp. That is, even though both dates fall on the same day, but difference in time will matter. Consider the example below:

//  plain date string
$input = "2016-11-09";

Because the input is plain date string, using strtotime() on $input will assume that it's the midnight of 2016-11-09. So, running time() anytime after midnight will always treat $input as past, even though they are on the same day.

To fix this, you can simply code, like this:

if (date("Y-m-d") <= $input)
{
    echo "Input date is equal to or greater than today.";
}

Regular Expression for matching parentheses

For any special characters you should use '\'. So, for matching parentheses - /\(/

Uninstall Node.JS using Linux command line?

If you have yum you could do:

yum remove nodesource-release* nodejs

yum clean all

And after that check if its deleted:

rpm -qa 'node|npm'

HTML how to clear input using javascript?

You don't need to bother with that. Just write

<input type="text" name="email" placeholder="[email protected]" size="30">

replace the value with placeholder

subquery in FROM must have an alias

add an ALIAS on the subquery,

SELECT  COUNT(made_only_recharge) AS made_only_recharge
FROM    
    (
        SELECT DISTINCT (identifiant) AS made_only_recharge
        FROM cdr_data
        WHERE CALLEDNUMBER = '0130'
        EXCEPT
        SELECT DISTINCT (identifiant) AS made_only_recharge
        FROM cdr_data
        WHERE CALLEDNUMBER != '0130'
    ) AS derivedTable                           -- <<== HERE

How can I convert a string to a float in mysql?

It turns out I was just missing DECIMAL on the CAST() description:

DECIMAL[(M[,D])]

Converts a value to DECIMAL data type. The optional arguments M and D specify the precision (M specifies the total number of digits) and the scale (D specifies the number of digits after the decimal point) of the decimal value. The default precision is two digits after the decimal point.

Thus, the following query worked:

UPDATE table SET
latitude = CAST(old_latitude AS DECIMAL(10,6)),
longitude = CAST(old_longitude AS DECIMAL(10,6));

How do I enable the column selection mode in Eclipse?

  • Press Alt + Shift + A
  • Observe that the screen zooms out
  • Make selection using the mouse
  • Press Alt + Shift + A to go back to the old mode. enter image description here

How to get current moment in ISO 8601 format with date, hour, and minute?

I do believe the easiest way is to first go to instant and then to string like:

String d = new Date().toInstant().toString();

Which will result in:

2017-09-08T12:56:45.331Z

Vim: How to insert in visual block mode?

if you want to add new text before or after the selected colum:

  • press ctrl+v
  • select columns
  • press shift+i
  • write your text
  • press esc
  • press "jj"

HTTP Error 500.19 and error code : 0x80070021

Try unlocking the relevant IIS (7.5) configuration settings at server level, as follows:

  1. Open IIS Manager
  2. Select the server in the Connections pane
  3. Open Configuration Editor in the main pane
  4. In the Sections drop down, select the section to unlock, e.g. system.webServer > defaultPath
  5. Click Unlock Attribute in the right pane
  6. Repeat for any other settings which you need to unlock
  7. Restart IIS (optional) - Select the server in the Conncetions pane, click Restart in the Actions pane

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

Obviously @Ian Ringrose's central thesis that you should be using a library for this is the best single answer here (hence a +1), but for minimal throwaway or demo code here's a concrete illustration of @SLaks's subtle comment on @Jon Skeet's more granular (+1'd) answer:

public List<XXX> Load( <<args>> )
{
    using ( var connection = CreateConnection() )
    using ( var command = Create<<ListXXX>>Command( <<args>>, connection ) )
    {
        connection.Open();
        using ( var reader = command.ExecuteReader() )
            return reader.Cast<IDataRecord>()
                .Select( x => new XXX( x.GetString( 0 ), x.GetString( 1 ) ) )
                .ToList();
    }
}

As in @Jon Skeet's answer, the

            .Select( x => new XXX( x.GetString( 0 ), x.GetString( 1 ) ) )

bit can be extracted into a helper (I like to dump them in the query class):

    public static XXX FromDataRecord( this IDataRecord record)
    {
        return new XXX( record.GetString( 0 ), record.GetString( 1 ) );
    }

and used as:

            .Select( FromDataRecord )

UPDATE Mar 9 13: See also Some excellent further subtle coding techniques to split out the boilerplate in this answer

Difference between Date(dateString) and new Date(dateString)

Any ideas on how to parse "2010-08-17 12:09:36" with new Date()?

Until ES5, there was no string format that browsers were required to support, though there are a number that are widely supported. However browser support is unreliable an inconsistent, e.g. some will allow out of bounds values and others wont, some support certain formats and others don't, etc.

ES5 introduced support for some ISO 8601 formats, however the OP is not compliant with ISO 8601 and not all browsers in use support it anyway.

The only reliable way is to use a small parsing function. The following parses the format in the OP and also validates the values.

_x000D_
_x000D_
/* Parse date string in format yyyy-mm-dd hh:mm:ss_x000D_
** If string contains out of bounds values, an invalid date is returned_x000D_
** _x000D_
** @param {string} s - string to parse, e.g. "2010-08-17 12:09:36"_x000D_
**                     treated as "local" date and time_x000D_
** @returns {Date}   - Date instance created from parsed string_x000D_
*/_x000D_
function parseDateString(s) {_x000D_
  var b = s.split(/\D/);_x000D_
  var d = new Date(b[0], --b[1], b[2], b[3], b[4], b[5]);_x000D_
  return d && d.getMonth() == b[1] && d.getHours() == b[3] &&_x000D_
         d.getMinutes() == b[4]? d : new Date(NaN);_x000D_
}_x000D_
  _x000D_
document.write(_x000D_
  parseDateString('2010-08-17 12:09:36') + '<br>' +  // Valid values_x000D_
  parseDateString('2010-08-45 12:09:36')             // Out of bounds date_x000D_
);
_x000D_
_x000D_
_x000D_

HTTP Headers for File Downloads

As explained by Alex's link you're probably missing the header Content-Disposition on top of Content-Type.

So something like this:

Content-Disposition: attachment; filename="MyFileName.ext"

How can I check if a View exists in a Database?

IN SQL Server ,

declare @ViewName nvarchar(20)='ViewNameExample'

if exists(SELECT 1 from sys.objects where object_Id=object_Id(@ViewName) and Type_Desc='VIEW')
begin
    -- Your SQL Code goes here ...

end

Is there a way to access an iteration-counter in Java's for-each loop?

The easiest solution is to just run your own counter thus:

int i = 0;
for (String s : stringArray) {
    doSomethingWith(s, i);
    i++;
}

The reason for this is because there's no actual guarantee that items in a collection (which that variant of for iterates over) even have an index, or even have a defined order (some collections may change the order when you add or remove elements).

See for example, the following code:

import java.util.*;

public class TestApp {
  public static void AddAndDump(AbstractSet<String> set, String str) {
    System.out.println("Adding [" + str + "]");
    set.add(str);
    int i = 0;
    for(String s : set) {
        System.out.println("   " + i + ": " + s);
        i++;
    }
  }

  public static void main(String[] args) {
    AbstractSet<String> coll = new HashSet<String>();
    AddAndDump(coll, "Hello");
    AddAndDump(coll, "My");
    AddAndDump(coll, "Name");
    AddAndDump(coll, "Is");
    AddAndDump(coll, "Pax");
  }
}

When you run that, you can see something like:

Adding [Hello]
   0: Hello
Adding [My]
   0: Hello
   1: My
Adding [Name]
   0: Hello
   1: My
   2: Name
Adding [Is]
   0: Hello
   1: Is
   2: My
   3: Name
Adding [Pax]
   0: Hello
   1: Pax
   2: Is
   3: My
   4: Name

indicating that, rightly so, order is not considered a salient feature of a set.

There are other ways to do it without a manual counter but it's a fair bit of work for dubious benefit.

When should I use Lazy<T>?

I have been considering using Lazy<T> properties to help improve the performance of my own code (and to learn a bit more about it). I came here looking for answers about when to use it but it seems that everywhere I go there are phrases like:

Use lazy initialization to defer the creation of a large or resource-intensive object, or the execution of a resource-intensive task, particularly when such creation or execution might not occur during the lifetime of the program.

from MSDN Lazy<T> Class

I am left a bit confused because I am not sure where to draw the line. For example, I consider linear interpolation as a fairly quick computation but if I don't need to do it then can lazy initialisation help me to avoid doing it and is it worth it?

In the end I decided to try my own test and I thought I would share the results here. Unfortunately I am not really an expert at doing these sort of tests and so I am happy to get comments that suggest improvements.

Description

For my case, I was particularly interested to see if Lazy Properties could help improve a part of my code that does a lot of interpolation (most of it being unused) and so I have created a test that compared 3 approaches.

I created a separate test class with 20 test properties (lets call them t-properties) for each approach.

  • GetInterp Class: Runs linear interpolation every time a t-property is got.
  • InitInterp Class: Initialises the t-properties by running the linear interpolation for each one in the constructor. The get just returns a double.
  • InitLazy Class: Sets up the t-properties as Lazy properties so that linear interpolation is run once when the property is first got. Subsequent gets should just return an already calculated double.

The test results are measured in ms and are the average of 50 instantiations or 20 property gets. Each test was then run 5 times.

Test 1 Results: Instantiation (average of 50 instantiations)

Class      1        2        3        4        5        Avg       %
------------------------------------------------------------------------
GetInterp  0.005668 0.005722 0.006704 0.006652 0.005572 0.0060636 6.72
InitInterp 0.08481  0.084908 0.099328 0.098626 0.083774 0.0902892 100.00
InitLazy   0.058436 0.05891  0.068046 0.068108 0.060648 0.0628296 69.59

Test 2 Results: First Get (average of 20 property gets)

Class      1        2        3        4        5        Avg       %
------------------------------------------------------------------------
GetInterp  0.263    0.268725 0.31373  0.263745 0.279675 0.277775 54.38
InitInterp 0.16316  0.161845 0.18675  0.163535 0.173625 0.169783 33.24
InitLazy   0.46932  0.55299  0.54726  0.47878  0.505635 0.510797 100.00

Test 3 Results: Second Get (average of 20 property gets)

Class      1        2        3        4        5        Avg       %
------------------------------------------------------------------------
GetInterp  0.08184  0.129325 0.112035 0.097575 0.098695 0.103894 85.30
InitInterp 0.102755 0.128865 0.111335 0.10137  0.106045 0.110074 90.37
InitLazy   0.19603  0.105715 0.107975 0.10034  0.098935 0.121799 100.00

Observations

GetInterp is fastest to instantiate as expected because its not doing anything. InitLazy is faster to instantiate than InitInterp suggesting that the overhead in setting up lazy properties is faster than my linear interpolation calculation. However, I am a bit confused here because InitInterp should be doing 20 linear interpolations (to set up it's t-properties) but it is only taking 0.09 ms to instantiate (test 1), compared to GetInterp which takes 0.28 ms to do just one linear interpolation the first time (test 2), and 0.1 ms to do it the second time (test 3).

It takes InitLazy almost 2 times longer than GetInterp to get a property the first time, while InitInterp is the fastest, because it populated its properties during instantiation. (At least that is what it should have done but why was it's instantiation result so much quicker than a single linear interpolation? When exactly is it doing these interpolations?)

Unfortunately it looks like there is some automatic code optimisation going on in my tests. It should take GetInterp the same time to get a property the first time as it does the second time, but it is showing as more than 2x faster. It looks like this optimisation is also affecting the other classes as well since they are all taking about the same amount of time for test 3. However, such optimisations may also take place in my own production code which may also be an important consideration.

Conclusions

While some results are as expected, there are also some very interesting unexpected results probably due to code optimisations. Even for classes that look like they are doing a lot of work in the constructor, the instantiation results show that they may still be very quick to create, compared to getting a double property. While experts in this field may be able to comment and investigate more thoroughly, my personal feeling is that I need to do this test again but on my production code in order to examine what sort of optimisations may be taking place there too. However, I am expecting that InitInterp may be the way to go.

Visual Studio 64 bit?

No! There is no 64-bit version of Visual Studio.

How to know it is not 64-bit: Once you download Visual Studio and click the install button, you will see that the initialization folder it selects automatically is C:\Program Files (x86)\Microsoft Visual Studio 14.0

As per my understanding, all 64-bit programs/applications goes to C:\Program Files and all 32-bit applications goes to C:\Program Files (x86) from Windows 7 onwards.

How do I detect a click outside an element?

 <div class="feedbackCont" onblur="hidefeedback();">
        <div class="feedbackb" onclick="showfeedback();" ></div>
        <div class="feedbackhide" tabindex="1"> </div>
 </div>

function hidefeedback(){
    $j(".feedbackhide").hide();
}

function showfeedback(){
    $j(".feedbackhide").show();
    $j(".feedbackCont").attr("tabindex",1).focus();
}

This is the simplest solution I came up with.

Mailto: Body formatting

From the first result on Google:

mailto:[email protected]_t?subject=Header&body=This%20is...%20the%20first%20line%0D%0AThis%20is%20the%20second

SQL Server query to find all permissions/access for all users in a database

Unfortunately I couldn't comment on the Sean Rose post due to insufficient reputation, however I had to amend the "public" role portion of the script as it didn't show SCHEMA-scoped permissions due to the (INNER) JOIN against sys.objects. After that was changed to a LEFT JOIN I further had to amend the WHERE-clause logic to omit system objects. My amended query for the public perms is below.

--3) List all access provisioned to the public role, which everyone gets by default
    SELECT
        @@servername ServerName
        , db_name() DatabaseName
        , [UserType]         = '{All Users}',
        [DatabaseUserName] = '{All Users}',
        [LoginName]        = '{All Users}',
        [Role]             = roleprinc.[name],
        [PermissionType]   = perm.[permission_name],
        [PermissionState]  = perm.[state_desc],
        [ObjectType] = CASE perm.[class]
                           WHEN 1 THEN obj.[type_desc]        -- Schema-contained objects
                           ELSE perm.[class_desc]             -- Higher-level objects
                       END,
        [Schema] = objschem.[name],
        [ObjectName] = CASE perm.[class]
                           WHEN 3 THEN permschem.[name]       -- Schemas
                           WHEN 4 THEN imp.[name]             -- Impersonations
                           ELSE OBJECT_NAME(perm.[major_id])  -- General objects
                       END,
        [ColumnName] = col.[name]
    FROM
        --Roles
        sys.database_principals            AS roleprinc
        --Role permissions
        LEFT JOIN sys.database_permissions AS perm      ON perm.[grantee_principal_id] = roleprinc.[principal_id]
        LEFT JOIN sys.schemas              AS permschem ON permschem.[schema_id] = perm.[major_id]
        --All objects
        LEFT JOIN sys.objects              AS obj       ON obj.[object_id] = perm.[major_id]
        LEFT JOIN sys.schemas              AS objschem  ON objschem.[schema_id] = obj.[schema_id]
        --Table columns
        LEFT JOIN sys.columns              AS col       ON col.[object_id] = perm.[major_id]
                                                           AND col.[column_id] = perm.[minor_id]
        --Impersonations
        LEFT JOIN sys.database_principals  AS imp       ON imp.[principal_id] = perm.[major_id]
    WHERE
        roleprinc.[type] = 'R'
        AND roleprinc.[name] = 'public'
        AND isnull(obj.[is_ms_shipped], 0) = 0
        AND isnull(object_schema_name(perm.[major_id]), '') <> 'sys'

ORDER BY
    [UserType],
    [DatabaseUserName],
    [LoginName],
    [Role],
    [Schema],
    [ObjectName],
    [ColumnName],
    [PermissionType],
    [PermissionState],
    [ObjectType]

How to allow only numeric (0-9) in HTML inputbox using jQuery?

I wanted to help a little, and I made my version, the onlyNumbers function...

function onlyNumbers(e){
    var keynum;
    var keychar;

    if(window.event){  //IE
        keynum = e.keyCode;
    }
    if(e.which){ //Netscape/Firefox/Opera
        keynum = e.which;
    }
    if((keynum == 8 || keynum == 9 || keynum == 46 || (keynum >= 35 && keynum <= 40) ||
       (event.keyCode >= 96 && event.keyCode <= 105)))return true;

    if(keynum == 110 || keynum == 190){
        var checkdot=document.getElementById('price').value;
        var i=0;
        for(i=0;i<checkdot.length;i++){
            if(checkdot[i]=='.')return false;
        }
        if(checkdot.length==0)document.getElementById('price').value='0';
        return true;
    }
    keychar = String.fromCharCode(keynum);

    return !isNaN(keychar);
}

Just add in input tag "...input ... id="price" onkeydown="return onlyNumbers(event)"..." and you are done ;)

Multiple ping script in Python

Try subprocess.call. It saves the return value of the program that was used.

According to my ping manual, it returns 0 on success, 2 when pings were sent but no reply was received and any other value indicates an error.

# typo error in import
import subprocess

for ping in range(1,10):
    address = "127.0.0." + str(ping)
    res = subprocess.call(['ping', '-c', '3', address])
    if res == 0:
        print "ping to", address, "OK"
    elif res == 2:
        print "no response from", address
    else:
        print "ping to", address, "failed!"

How to create a simple http proxy in node.js?

I juste wrote a proxy in nodejs that take care of HTTPS with optional decoding of the message. This proxy also can add proxy-authentification header in order to go through a corporate proxy. You need to give as argument the url to find the proxy.pac file in order to configurate the usage of corporate proxy.

https://github.com/luckyrantanplan/proxy-to-proxy-https

force client disconnect from server with socket.io and nodejs

Any reason why you can't have the server emit a message to the client that makes it call the disconnect function?

On client:

socket.emit('forceDisconnect');

On Server:

socket.on('forceDisconnect', function(){
    socket.disconnect();
});

Photoshop text tool adds punctuation to the beginning of text

This is a paragraph option. Go to Window>Paragraph then a small window will pop up. You will have two buttons on the bottom. One with a arrow on the left of P and one on the right. Select the right one.

Convenient C++ struct initialisation

What about this syntax?

typedef struct
{
    int a;
    short b;
}
ABCD;

ABCD abc = { abc.a = 5, abc.b = 7 };

Just tested on a Microsoft Visual C++ 2015 and on g++ 6.0.2. Working OK.
You can make a specific macro also if you want to avoid duplicating variable name.

How do I know the script file name in a Bash script?

Re: Tanktalus's (accepted) answer above, a slightly cleaner way is to use:

me=$(readlink --canonicalize --no-newline $0)

If your script has been sourced from another bash script, you can use:

me=$(readlink --canonicalize --no-newline $BASH_SOURCE)

I agree that it would be confusing to dereference symlinks if your objective is to provide feedback to the user, but there are occasions when you do need to get the canonical name to a script or other file, and this is the best way, imo.

Responsive background image in div full width

When you use background-size: cover the background image will automatically be stretched to cover the entire container. Aspect ratio is maintained however, so you will always lose part of the image, unless the aspect ratio of the image and the element it is applied to are identical.

I see two ways you could solve this:

  • Do not maintain the aspect ratio of the image by setting background-size: 100% 100% This will also make the image cover the entire container, but the ratio will not be maintained. Disadvantage is that this distorts your image, and therefore may look very weird, depending on the image. With the image you are using in the fiddle, I think you could get away with it though.

  • You could also calculate and set the height of the element with javascript, based on its width, so it gets the same ratio as the image. This calculation would have to be done on load and on resize. It should be easy enough with a few lines of code (feel free to ask if you want an example). Disadvantage of this method is that your width may become very small (on mobile devices), and therfore the calculated height also, which may cause the content of the container to overflow. This could be solved by changing the size of the content as well or something, but it adds some complexity to the solution/

MySQL SELECT statement for the "length" of the field is greater than 1

How about:

SELECT * FROM sometable WHERE CHAR_LENGTH(LINK) > 1

Here's the MySql string functions page (5.0).

Note that I chose CHAR_LENGTH instead of LENGTH, as if there are multibyte characters in the data you're probably really interested in how many characters there are, not how many bytes of storage they take. So for the above, a row where LINK is a single two-byte character wouldn't be returned - whereas it would when using LENGTH.

Note that if LINK is NULL, the result of CHAR_LENGTH(LINK) will be NULL as well, so the row won't match.

Get all non-unique values (i.e.: duplicate/more than one occurrence) in an array

Modifying @RaphaelMontanaro's solution, borrowing from @Nosredna's blog, here is what you could do if you just want to identify the duplicate elements from your array.

function identifyDuplicatesFromArray(arr) {
        var i;
        var len = arr.length;
        var obj = {};
        var duplicates = [];

        for (i = 0; i < len; i++) {

            if (!obj[arr[i]]) {

                obj[arr[i]] = {};

            }

            else
            {
                duplicates.push(arr[i]);
            }

        }
        return duplicates;
    }

Thanks for the elegant solution, @Nosredna!

how to set image from url for imageView

Using Glide library:

Glide.with(context)
  .load(new File(url)
  .diskCacheStrategy(DiskCacheStrategy.ALL)
  .into(imageView);

Why does HTML think “chucknorris” is a color?

Most browsers will simply ignore any NON-hex values in your color string, substituting non-hex digits with zeros.

ChuCknorris translates to c00c0000000. At this point, the browser will divide the string into three equal sections, indicating Red, Green and Blue values: c00c 0000 0000. Extra bits in each section will be ignored, which makes the final result #c00000 which is a reddish color.

Note, this does not apply to CSS color parsing, which follow the CSS standard.

_x000D_
_x000D_
<p><font color='chucknorris'>Redish</font></p>_x000D_
<p><font color='#c00000'>Same as above</font></p>_x000D_
<p><span style="color: chucknorris">Black</span></p>
_x000D_
_x000D_
_x000D_

How to send a simple string between two programs using pipes?

First, have program 1 write the string to stdout (as if you'd like it to appear in screen). Then the second program should read a string from stdin, as if a user was typing from a keyboard. then you run:

$ program_1 | program_2

Cordova app not displaying correctly on iPhone X (Simulator)

I found the solution to the white bars here:

Set viewport-fit=cover on the viewport <meta> tag, i.e.:

<meta name="viewport" content="initial-scale=1, width=device-width, height=device-height, viewport-fit=cover">

The white bars in UIWebView then disappear:

The solution to remove the black areas (provided by @dpogue in a comment below) is to use LaunchStoryboard images with cordova-plugin-splashscreen to replace the legacy launch images, used by Cordova by default. To do so, add the following to the iOS platform in config.xml:

<platform name="ios">    
    <splash src="res/screen/ios/Default@2x~iphone~anyany.png" />
    <splash src="res/screen/ios/Default@2x~iphone~comany.png" />
    <splash src="res/screen/ios/Default@2x~iphone~comcom.png" />
    <splash src="res/screen/ios/Default@3x~iphone~anyany.png" />
    <splash src="res/screen/ios/Default@3x~iphone~anycom.png" />
    <splash src="res/screen/ios/Default@3x~iphone~comany.png" />
    <splash src="res/screen/ios/Default@2x~ipad~anyany.png" />
    <splash src="res/screen/ios/Default@2x~ipad~comany.png" />   

    <!-- more iOS config... -->
</platform>

Then create the images with the following dimensions in res/screen/ios (remove any existing ones):

Default@2x~iphone~anyany.png - 1334x1334
Default@2x~iphone~comany.png - 750x1334
Default@2x~iphone~comcom.png - 1334x750
Default@3x~iphone~anyany.png - 2208x2208
Default@3x~iphone~anycom.png - 2208x1242
Default@3x~iphone~comany.png - 1242x2208
Default@2x~ipad~anyany.png - 2732x2732
Default@2x~ipad~comany.png - 1278x2732

Once the black bars are removed, there's another thing that's different about the iPhone X to address: The status bar is larger than 20px due to the "notch", which means any content at the far top of your Cordova app will be obscured by it:

Rather than hard-coding a padding in pixels, you can handle this automatically in CSS using the new safe-area-inset-* constants in iOS 11.

Note: in iOS 11.0 the function to handle these constants was called constant() but in iOS 11.2 Apple renamed it to env() (see here), therefore to cover both cases you need to overload the CSS rule with both and rely on the CSS fallback mechanism to apply the appropriate one:

body{
    padding-top: constant(safe-area-inset-top);
    padding-top: env(safe-area-inset-top);
}

The result is then as desired: the app content covers the full screen, but is not obscured by the "notch":

I've created a Cordova test project which illustrates the above steps: webview-test.zip

Notes:

Footer buttons

  • If your app has footer buttons (as mine does), you will also need to apply safe-area-inset-bottom to avoid them being overlapped by the virtual Home button on iPhone X.
  • In my case, I couldn't apply this to <body> as the footer is absolutely positioned, so I needed to apply it directly to the footer:

.toolbar-footer{
    margin-bottom: constant(safe-area-inset-bottom);
    margin-bottom: env(safe-area-inset-bottom);
}

cordova-plugin-statusbar

  • The status bar size has changed on iPhone X, so older versions of cordova-plugin-statusbar display incorrectly on iPhone X
  • Mike Hartington has created this pull request which applies the necessary changes.
  • This was merged into the [email protected] release, so make sure you're using at least this version to apply to safe-area-insets

splashscreen

  • The LaunchScreen storyboard constraints changed on iOS 11/iPhone X, meaning the splashscreen appeared to "jump" on launch when using existing versions of the plugin (see here).
  • This was captured in bug report CB-13505, fixed PR cordova-ios#354 and released in [email protected], so make sure you're using a recent version of the cordova-ios platform.

device orientation

  • When using UIWebView on iOS 11.0, rotating from portrait > landscape > portrait causes the safe-area-inset not to be re-applied, causing the content to be obscured by the notch again (as highlighted by jms in a comment below).
  • Also happens if app is launched in landscape then rotated to portrait
  • This doesn't happen when using WKWebView via cordova-plugin-wkwebview-engine.
  • Radar report: http://www.openradar.me/radar?id=5035192880201728
  • Update: this appears to have been fixed in iOS 11.1

For reference, this is the original Cordova issue I opened which captures this: https://issues.apache.org/jira/browse/CB-13273

How to downgrade Node version

This may be due to version incompatibility between your code and the version you have installed.

In my case I was using v8.12.0 for development (locally) and installed latest version v13.7.0 on the server.

So using nvm I switched the node version to v8.12.0 with the below command:

> nvm install 8.12.0 // to install the version I wanted

> nvm use 8.12.0  // use the installed version

NOTE: You need to install nvm on your system to use nvm.

You should try this solution before trying solutions like installing build-essentials or uninstalling the current node version because you could switch between versions easily than reverting all the installations/uninstallations that you've done.

How to change the text color of first select option

What about this:

_x000D_
_x000D_
select{
  width: 150px;
  height: 30px;
  padding: 5px;
  color: green;
}
select option { color: black; }
select option:first-child{
  color: green;
}
_x000D_
<select>
  <option>one</option>
  <option>two</option>
</select>
_x000D_
_x000D_
_x000D_

http://jsbin.com/acucan/9

How to display a PDF via Android web browser without "downloading" first

You can open PDF in Google Docs Viewer by appending URL to:

http://docs.google.com/gview?embedded=true&url=<url of a supported doc>

This would open PDF in default browser or a WebView.

A list of supported formats is given here.

Keep the order of the JSON keys during JSON conversion to CSV

Another hacky solution using reflect:

JSONObject json = new JSONObject();
Field map = json.getClass().getDeclaredField("map");
map.setAccessible(true);//because the field is private final...
map.set(json, new LinkedHashMap<>());
map.setAccessible(false);//return flag

Is it possible to run CUDA on AMD GPUs?

Nope, you can't use CUDA for that. CUDA is limited to NVIDIA hardware. OpenCL would be the best alternative.

Khronos itself has a list of resources. As does the StreamComputing.eu website. For your AMD specific resources, you might want to have a look at AMD's APP SDK page.

Note that at this time there are several initiatives to translate/cross-compile CUDA to different languages and APIs. One such an example is HIP. Note however that this still does not mean that CUDA runs on AMD GPUs.

How do I find an array item with TypeScript? (a modern, easier way)

For some projects it's easier to set your target to es6 in your tsconfig.json.

{
  "compilerOptions": {
    "target": "es6",
    ...

How do I pass multiple attributes into an Angular.js attribute directive?

The directive can access any attribute that is defined on the same element, even if the directive itself is not the element.

Template:

<div example-directive example-number="99" example-function="exampleCallback()"></div>

Directive:

app.directive('exampleDirective ', function () {
    return {
        restrict: 'A',   // 'A' is the default, so you could remove this line
        scope: {
            callback : '&exampleFunction',
        },
        link: function (scope, element, attrs) {
            var num = scope.$eval(attrs.exampleNumber);
            console.log('number=',num);
            scope.callback();  // calls exampleCallback()
        }
    };
});

fiddle

If the value of attribute example-number will be hard-coded, I suggest using $eval once, and storing the value. Variable num will have the correct type (a number).

How to hide 'Back' button on navigation bar on iPhone?

In c# or Xamarin.ios, this.NavigationItem.HidesBackButton = true;

How to test if a double is an integer

Try this way,

public static boolean isInteger(double number){
    return Math.ceil(number) == Math.floor(number); 
}

for example:

Math.ceil(12.9) = 13; Math.floor(12.9) = 12;

hence 12.9 is not integer, nevertheless

 Math.ceil(12.0) = 12; Math.floor(12.0) =12; 

hence 12.0 is integer

Launch Pycharm from command line (terminal)

Navigate to the directory on the terminal cd [your directory]

Navigate to the directory on the terminal

use charm . to open the project in PyCharm

Simplest and quickest way to open a project in PyCharm

Python class inherits object

History from Learn Python the Hard Way:

Python's original rendition of a class was broken in many serious ways. By the time this fault was recognized it was already too late, and they had to support it. In order to fix the problem, they needed some "new class" style so that the "old classes" would keep working but you can use the new more correct version.

They decided that they would use a word "object", lowercased, to be the "class" that you inherit from to make a class. It is confusing, but a class inherits from the class named "object" to make a class but it's not an object really its a class, but don't forget to inherit from object.

Also just to let you know what the difference between new-style classes and old-style classes is, it's that new-style classes always inherit from object class or from another class that inherited from object:

class NewStyle(object):
    pass

Another example is:

class AnotherExampleOfNewStyle(NewStyle):
    pass

While an old-style base class looks like this:

class OldStyle():
    pass

And an old-style child class looks like this:

class OldStyleSubclass(OldStyle):
    pass

You can see that an Old Style base class doesn't inherit from any other class, however, Old Style classes can, of course, inherit from one another. Inheriting from object guarantees that certain functionality is available in every Python class. New style classes were introduced in Python 2.2

List only stopped Docker containers

Only stopped containers can be listed using:

docker ps --filter "status=exited"

or

docker ps -f "status=exited"

Equal height rows in a flex container

If you know the items you are mapping through, you can accomplish this by doing one row at a time. I know it's a workaround, but it works.

For me I had 4 items per row, so I broke it up into two rows of 4 with each row height: 50%, get rid of flex-grow, have <RowOne /> and <RowTwo /> in a <div> with flex-column. This will do the trick

<div class='flexbox flex-column height-100-percent'>
   <RowOne class='flex height-50-percent' />
   <RowTwo class='flex height-50-percent' />
</div>

Execute a batch file on a remote PC using a batch file on local PC

If you are in same WORKGROUP shutdown.exe /s /m \\<target-computer-name> should be enough shutdown /? for more, otherwise you need software to connect and control the target server.

UPDATE:

Seems shutdown.bat here is for shutting down apache-tomcat.

So, you might be interested to psexec or PuTTY: A Free Telnet/SSH Client

As native solution could be wmic

Example:

wmic /node:<target-computer-name> process call create "cmd.exe c:\\somefolder\\batch.bat"

In your example should be:

wmic /node:inidsoasrv01 process call create ^
    "cmd.exe D:\\apache-tomcat-6.0.20\\apache-tomcat-7.0.30\\bin\\shutdown.bat"

wmic /? and wmic /node /? for more

MySQL: Fastest way to count number of rows

EXPLAIN SELECT id FROM .... did the trick for me. and I could see the number of rows under rows column of the result.

Check if value is zero or not null in python

Zero and None both treated as same for if block, below code should work fine.

if number or number==0:
    return True

Add line break within tooltips

if you are using jquery-ui 1.11.4:

var tooltip = $.widget( "ui.tooltip", {
    version: "1.11.4",
    options: {
        content: function() {
            // support: IE<9, Opera in jQuery <1.7
            // .text() can't accept undefined, so coerce to a string
            var title = $( this ).attr( "title" ) || "";
            // Escape title, since we're going from an attribute to raw HTML
Replace-->  //return $( "<a>" ).text( title ).html();
by -->      return $( "<a>" ).html( title );
             },

How to fix 'Object arrays cannot be loaded when allow_pickle=False' for imdb.load_data() function?

none of the above listed solutions worked for me: i run anaconda with python 3.7.3. What worked for me was

  • run "conda install numpy==1.16.1" from Anaconda powershell

  • close and reopen the notebook

How can I count the number of children?

You can use .length, like this:

var count = $("ul li").length;

.length tells how many matches the selector found, so this counts how many <li> under <ul> elements you have...if there are sub-children, use "ul > li" instead to get only direct children. If you have other <ul> elements in your page, just change the selector to match only his one, for example if it has an ID you'd use "#myListID > li".

In other situations where you don't know the child type, you can use the * (wildcard) selector, or .children(), like this:

var count = $(".parentSelector > *").length;

or:

var count = $(".parentSelector").children().length;

How to switch back to 'master' with git?

According to the Git Cheatsheet you have to create the branch first

git branch [branchName]

and then

git checkout [branchName]

How to force a web browser NOT to cache images

I checked all the answers around the web and the best one seemed to be: (actually it isn't)

<img src="image.png?cache=none">

at first.

However, if you add cache=none parameter (which is static "none" word), it doesn't effect anything, browser still loads from cache.

Solution to this problem was:

<img src="image.png?nocache=<?php echo time(); ?>">

where you basically add unix timestamp to make the parameter dynamic and no cache, it worked.

However, my problem was a little different: I was loading on the fly generated php chart image, and controlling the page with $_GET parameters. I wanted the image to be read from cache when the URL GET parameter stays the same, and do not cache when the GET parameters change.

To solve this problem, I needed to hash $_GET but since it is array here is the solution:

$chart_hash = md5(implode('-', $_GET));
echo "<img src='/images/mychart.png?hash=$chart_hash'>";

Edit:

Although the above solution works just fine, sometimes you want to serve the cached version UNTIL the file is changed. (with the above solution, it disables the cache for that image completely) So, to serve cached image from browser UNTIL there is a change in the image file use:

echo "<img src='/images/mychart.png?hash=" . filemtime('mychart.png') . "'>";

filemtime() gets file modification time.

Javascript "Uncaught TypeError: object is not a function" associativity question

JavaScript does require semicolons, it's just that the interpreter will insert them for you on line breaks where possible*.

Unfortunately, the code

var a = new B(args)(stuff)()

does not result in a syntax error, so no ; will be inserted. (An example which can run is

var answer = new Function("x", "return x")(function(){return 42;})();

To avoid surprises like this, train yourself to always end a statement with ;.


* This is just a rule of thumb and not always true. The insertion rule is much more complicated. This blog page about semicolon insertion has more detail.

Maximum value for long integer

Direct answer to title question:

Integers are unlimited in size and have no maximum value in Python.

Answer which addresses stated underlying use case:

According to your comment of what you're trying to do, you are currently thinking something along the lines of

minval = MAXINT;
for (i = 1; i < num_elems; i++)
    if a[i] < a[i-1]
        minval = a[i];

That's not how to think in Python. A better translation to Python (but still not the best) would be

minval = a[0]  # Just use the first value
for i in range(1, len(a)):
    minval = min(a[i], a[i - 1])

Note that the above doesn't use MAXINT at all. That part of the solution applies to any programming language: You don't need to know the highest possible value just to find the smallest value in a collection.

But anyway, what you really do in Python is just

minval = min(a)

That is, you don't write a loop at all. The built-in min() function gets the minimum of the whole collection.

How to use an existing database with an Android application

NOTE: Before trying this code, please find this line in the below code:

private static String DB_NAME ="YourDbName"; // Database name

DB_NAME here is the name of your database. It is assumed that you have a copy of the database in the assets folder, so for example, if your database name is ordersDB, then the value of DB_NAME will be ordersDB,

private static String DB_NAME ="ordersDB";

Keep the database in assets folder and then follow the below:

DataHelper class:

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;

import android.content.Context;
import android.database.SQLException;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import android.util.Log;

public class DataBaseHelper extends SQLiteOpenHelper {

    private static String TAG = "DataBaseHelper"; // Tag just for the LogCat window
    private static String DB_NAME ="YourDbName"; // Database name
    private static int DB_VERSION = 1; // Database version
    private final File DB_FILE;
    private SQLiteDatabase mDataBase;
    private final Context mContext;

    public DataBaseHelper(Context context) {
        super(context, DB_NAME, null, DB_VERSION);
        DB_FILE = context.getDatabasePath(DB_NAME);
        this.mContext = context;
    }

    public void createDataBase() throws IOException {
        // If the database does not exist, copy it from the assets.
        boolean mDataBaseExist = checkDataBase();
        if(!mDataBaseExist) {
            this.getReadableDatabase();
            this.close();
            try {
                // Copy the database from assests
                copyDataBase();
                Log.e(TAG, "createDatabase database created");
            } catch (IOException mIOException) {
                throw new Error("ErrorCopyingDataBase");
            }
        }
    }

    // Check that the database file exists in databases folder
    private boolean checkDataBase() {
        return DB_FILE.exists();
    }

    // Copy the database from assets
    private void copyDataBase() throws IOException {
        InputStream mInput = mContext.getAssets().open(DB_NAME);
        OutputStream mOutput = new FileOutputStream(DB_FILE);
        byte[] mBuffer = new byte[1024];
        int mLength;
        while ((mLength = mInput.read(mBuffer)) > 0) {
            mOutput.write(mBuffer, 0, mLength);
        }
        mOutput.flush();
        mOutput.close();
        mInput.close();
    }

    // Open the database, so we can query it
    public boolean openDataBase() throws SQLException {
        // Log.v("DB_PATH", DB_FILE.getAbsolutePath());
        mDataBase = SQLiteDatabase.openDatabase(DB_FILE, null, SQLiteDatabase.CREATE_IF_NECESSARY);
        // mDataBase = SQLiteDatabase.openDatabase(DB_FILE, null, SQLiteDatabase.NO_LOCALIZED_COLLATORS);
        return mDataBase != null;
    }

    @Override
    public synchronized void close() {
        if(mDataBase != null) {
            mDataBase.close();
        }
        super.close();
    }

}

Write a DataAdapter class like:

import java.io.IOException;
import android.content.Context;
import android.database.Cursor;
import android.database.SQLException;
import android.database.sqlite.SQLiteDatabase;
import android.util.Log;

public class TestAdapter {

    protected static final String TAG = "DataAdapter";

    private final Context mContext;
    private SQLiteDatabase mDb;
    private DataBaseHelper mDbHelper;

    public TestAdapter(Context context) {
        this.mContext = context;
        mDbHelper = new DataBaseHelper(mContext);
    }

    public TestAdapter createDatabase() throws SQLException {
        try {
            mDbHelper.createDataBase();
        } catch (IOException mIOException) {
            Log.e(TAG, mIOException.toString() + "  UnableToCreateDatabase");
            throw new Error("UnableToCreateDatabase");
        }
        return this;
    }

    public TestAdapter open() throws SQLException {
        try {
            mDbHelper.openDataBase();
            mDbHelper.close();
            mDb = mDbHelper.getReadableDatabase();
        } catch (SQLException mSQLException) {
            Log.e(TAG, "open >>"+ mSQLException.toString());
            throw mSQLException;
        }
        return this;
    }

    public void close() {
        mDbHelper.close();
    }

     public Cursor getTestData() {
         try {
             String sql ="SELECT * FROM myTable";
             Cursor mCur = mDb.rawQuery(sql, null);
             if (mCur != null) {
                mCur.moveToNext();
             }
             return mCur;
         } catch (SQLException mSQLException) {
             Log.e(TAG, "getTestData >>"+ mSQLException.toString());
             throw mSQLException;
         }
     }
}

Now you can use it like:

TestAdapter mDbHelper = new TestAdapter(urContext);
mDbHelper.createDatabase();
mDbHelper.open();

Cursor testdata = mDbHelper.getTestData();

mDbHelper.close();

EDIT: Thanks to JDx

For Android 4.1 (Jelly Bean), change:

DB_PATH = "/data/data/" + context.getPackageName() + "/databases/";

to:

DB_PATH = context.getApplicationInfo().dataDir + "/databases/";

in the DataHelper class, this code will work on Jelly Bean 4.2 multi-users.

EDIT: Instead of using hardcoded path, we can use

DB_PATH = context.getDatabasePath(DB_NAME).getAbsolutePath();

which will give us the full path to the database file and works on all Android versions

Isn't the size of character in Java 2 bytes?

Looks like your file contains ASCII characters, which are encoded in just 1 byte. If text file was containing non-ASCII character, e.g. 2-byte UTF-8, then you get just the first byte, not whole character.

External resource not being loaded by AngularJs

Based on the error message, your problem seems to be related to interpolation (typically your expression {{}}), not to a cross-domain issue. Basically ng-src="{{object.src}}" sucks.

ng-src was designed with img tag in mind IMO. It might not be appropriate for <source>. See http://docs.angularjs.org/api/ng.directive:ngSrc

If you declare <source src="somesite.com/myvideo.mp4"; type="video/mp4"/>, it will be working, right? (note that I remove ng-src in favor of src) If not it must be fixed first.

Then ensure that {{object.src}} returns the expected value (outside of <video>):

<span>{{object.src}}</span>
<video>...</video>

If it returns the expected value, the following statement should be working:

<source src="{{object.src}}"; type="video/mp4"/> //src instead of ng-src

android.content.Context.getPackageName()' on a null object reference

Use can use in global

Context context;

and create a constructor and passing the context. LoginClass is name of the class

LoginClass(Context context)
{this.context=context;}

and also when we call the class then use getApplicationContext like LoginClass lclass = new LoginClass(getApplicationContext) thats it.

Apache 2.4.3 (with XAMPP 1.8.1) not starting in windows 8

So here is the solution for this:

I check port 80 used by Skype, after that I changes port to 81 and also along with that somewhere i read this error may be because of SSL Port then I changed SSL port to 444. However this got resolved easily.

One most important thing to notice here, all the port changes should be done inside config files, for http port change: httpd.conf for SSL httpd-ssl.conf. Otherwise changes will not replicate to Apache, Sometime PC reboot is also required.

Edit: Make Apache use port 80 and make Skype communicate on other Port

For those who are struggling with Skype, want to change its port and to make Apache to use port 80.

No need to Re-Install, Here is simply how to change Skype Port

Goto: Tools > Options > Advanced > Connection

There you need to uncheck Use port 80 and 443 as alternative for incoming connections.

That's it, here is screen shot of it.

Changing Skype Port

Use LIKE %..% with field values in MySQL

  SELECT t1.a, t2.b
  FROM t1
  JOIN t2 ON t1.a LIKE '%'+t2.b +'%'

because the last answer not work

How to add items to a spinner in Android?

To add one more item to Spinner you can:

ArrayAdapter myAdapter = 
  ((ArrayAdapter) mySpinner.getAdapter());

myAdapter.add(myValue);

myAdapter.notifyDataSetChanged();

run a python script in terminal without the python command

You use a shebang line at the start of your script:

#!/usr/bin/env python

make the file executable:

chmod +x arbitraryname

and put it in a directory on your PATH (can be a symlink):

cd ~/bin/
ln -s ~/some/path/to/myscript/arbitraryname

how to sort an ArrayList in ascending order using Collections and Comparator

Use the default version:

Collections.sort(myarrayList);

Of course this requires that your Elements implement Comparable, but the same holds true for the version you mentioned.

BTW: you should use generics in your code, that way you get compile-time errors if your class doesn't implement Comparable. And compile-time errors are much better than the runtime errors you'll get otherwise.

List<MyClass> list = new ArrayList<MyClass>();
// now fill up the list

// compile error here unless MyClass implements Comparable
Collections.sort(list); 

Vue - Deep watching an array of objects and calculating the change?

I have changed the implementation of it to get your problem solved, I made an object to track the old changes and compare it with that. You can use it to solve your issue.

Here I created a method, in which the old value will be stored in a separate variable and, which then will be used in a watch.

new Vue({
  methods: {
    setValue: function() {
      this.$data.oldPeople = _.cloneDeep(this.$data.people);
    },
  },
  mounted() {
    this.setValue();
  },
  el: '#app',
  data: {
    people: [
      {id: 0, name: 'Bob', age: 27},
      {id: 1, name: 'Frank', age: 32},
      {id: 2, name: 'Joe', age: 38}
    ],
    oldPeople: []
  },
  watch: {
    people: {
      handler: function (after, before) {
        // Return the object that changed
        var vm = this;
        let changed = after.filter( function( p, idx ) {
          return Object.keys(p).some( function( prop ) {
            return p[prop] !== vm.$data.oldPeople[idx][prop];
          })
        })
        // Log it
        vm.setValue();
        console.log(changed)
      },
      deep: true,
    }
  }
})

See the updated codepen

How to append data to div using JavaScript?

Even this will work:

var div = document.getElementById('divID');

div.innerHTML += 'Text to append';

rsync error: failed to set times on "/foo/bar": Operation not permitted

As @racl101 has commented on an answer, this problem might be related to the folder owner. The rsync command should be done by the same user as the folder owner's one. If it's not the same, you can change it.

chown -R userCorrect /remote/path/to/foo/bar

Set Date in a single line

Why don't you just write a simple utility method:

public final class DateUtils {
    private DateUtils() {
    }

    public static Calendar calendarFor(int year, int month, int day) {
        Calendar cal = Calendar.getInstance();
        cal.set(Calendar.YEAR, year);
        cal.set(Calendar.MONTH, month);
        cal.set(Calendar.DAY_OF_MONTH, day);
        return cal;
    }

    // ... maybe other utility methods
}

And then call that everywhere in the rest of your code:

Calendar cal = DateUtils.calendarFor(2010, Calendar.MAY, 21);

Using Application context everywhere?

I like it, but I would suggest a singleton instead:

package com.mobidrone;

import android.app.Application;
import android.content.Context;

public class ApplicationContext extends Application
{
    private static ApplicationContext instance = null;

    private ApplicationContext()
    {
        instance = this;
    }

    public static Context getInstance()
    {
        if (null == instance)
        {
            instance = new ApplicationContext();
        }

        return instance;
    }
}

No module named Image

Did you setup PIL module? Link

You can try to reinstall it on your computer.

Embed website into my site

Put content from other site in iframe

<iframe src="/othersiteurl" width="100%" height="300">
  <p>Your browser does not support iframes.</p>
</iframe>

Change background colour for Visual Studio

Tools -> Options -> Under the Environment section there are Fonts & Colors, change the Item Background.

What is AF_INET, and why do I need it?

it defines the protocols address family.this determines the type of socket created. pocket pc support AF_INET.

the content in the following page is quite decent http://etutorials.org/Programming/Pocket+pc+network+programming/Chapter+1.+Winsock/Streaming+TCP+Sockets/

Convert an object to an XML string

I realize this is a very old post, but after looking at L.B's response I thought about how I could improve upon the accepted answer and make it generic for my own application. Here's what I came up with:

public static string Serialize<T>(T dataToSerialize)
{
    try
    {
        var stringwriter = new System.IO.StringWriter();
        var serializer = new XmlSerializer(typeof(T));
        serializer.Serialize(stringwriter, dataToSerialize);
        return stringwriter.ToString();
    }
    catch
    {
        throw;
    }
}

public static T Deserialize<T>(string xmlText)
{
    try
    {
        var stringReader = new System.IO.StringReader(xmlText);
        var serializer = new XmlSerializer(typeof(T));
        return (T)serializer.Deserialize(stringReader);
    }
    catch
    {
        throw;
    }
}

These methods can now be placed in a static helper class, which means no code duplication to every class that needs to be serialized.

Hash String via SHA-256 in Java

This is already implemented in the runtime libs.

public static String calc(InputStream is) {
    String output;
    int read;
    byte[] buffer = new byte[8192];

    try {
        MessageDigest digest = MessageDigest.getInstance("SHA-256");
        while ((read = is.read(buffer)) > 0) {
            digest.update(buffer, 0, read);
        }
        byte[] hash = digest.digest();
        BigInteger bigInt = new BigInteger(1, hash);
        output = bigInt.toString(16);
        while ( output.length() < 32 ) {
            output = "0"+output;
        }
    } 
    catch (Exception e) {
        e.printStackTrace(System.err);
        return null;
    }

    return output;
}

In a JEE6+ environment one could also use JAXB DataTypeConverter:

import javax.xml.bind.DatatypeConverter;

String hash = DatatypeConverter.printHexBinary( 
           MessageDigest.getInstance("MD5").digest("SOMESTRING".getBytes("UTF-8")));

Two dimensional array in python

We can create multidimensional array dynamically as follows,

Create 2 variables to read x and y from standard input:

 print("Enter the value of x: ")
 x=int(input())

 print("Enter the value of y: ")
 y=int(input())

Create an array of list with initial values filled with 0 or anything using the following code

z=[[0 for row in range(0,x)] for col in range(0,y)]

creates number of rows and columns for your array data.

Read data from standard input:

for i in range(x):
         for j in range(y):
             z[i][j]=input()

Display the Result:

for i in range(x):
         for j in range(y):
             print(z[i][j],end=' ')
         print("\n")

or use another way to display above dynamically created array is,

for row in z:
     print(row)

How to center links in HTML

there are some mistakes in your code - the first: you havn't closed you p-tag:

<a href="http//www.google.com"><p style="text-align:center">Search</p></a>

next: p stands for 'paragraph' and is a block-element (so it's causing a line-break). what you wanted to use there is a span, wich is just an inline-element for formatting:

<a href="http//www.google.com"><span style="text-align:center">Search</span></a>

but if you just want to add a style to your link, why don't you set the style for that link directly:

<a href="http//www.google.com" style="text-align:center">Search</a>

in the end, this would at least be correct html, but still not exactly what you want, because text-align:center centers the text in that element, so you would have to set that for the element that contains this links (this piece of html isn't posted, so i can't correct you, but i hope you understand) - to show this, i'll use a simple div:

<div style="text-align:center">    
  <a href="http//www.google.com">Search</a>
  <!-- more links here -->
</div>

EDIT: some more additions to your question:

  • p is not a 'function', but you're right, this is causing the problem (because it's a block-element)
  • what you're trying to use is css - it's just inline instead of being placed in a seperate file, but you aren't doing 'just HTML' here

Insert string in beginning of another string

private static void appendZeroAtStart() {
        String strObj = "11";
        int maxLegth = 5;

        StringBuilder sb = new StringBuilder(strObj);
        if (sb.length() <= maxLegth) {
            while (sb.length() < maxLegth) {
                sb.insert(0, '0');
            }
        } else {
            System.out.println("error");
        }

        System.out.println("result: " + sb);

    }

SQL: Select columns with NULL values only

You might need to clarify a bit. What are you really trying to accomplish? If you really want to find out the column names that only contain null values, then you will have to loop through the scheama and do a dynamic query based on that.

I don't know which DBMS you are using, so I'll put some pseudo-code here.

for each col
begin
  @cmd = 'if not exists (select * from tablename where ' + col + ' is not null begin print ' + col + ' end'
exec(@cmd)
end

Subset a dataframe by multiple factor levels

Try this:

> data[match(as.character(data$Code), selected, nomatch = FALSE), ]
    Code Value
1      A     1
2      B     2
1.1    A     1
1.2    A     1

How do I resize a Google Map with JavaScript after it has loaded?

for Google Maps v3, you need to trigger the resize event differently:

google.maps.event.trigger(map, "resize");

See the documentation for the resize event (you'll need to search for the word 'resize'): http://code.google.com/apis/maps/documentation/v3/reference.html#event


Update

This answer has been here a long time, so a little demo might be worthwhile & although it uses jQuery, there's no real need to do so.

_x000D_
_x000D_
$(function() {
  var mapOptions = {
    zoom: 8,
    center: new google.maps.LatLng(-34.397, 150.644)
  };
  var map = new google.maps.Map($("#map-canvas")[0], mapOptions);

  // listen for the window resize event & trigger Google Maps to update too
  $(window).resize(function() {
    // (the 'map' here is the result of the created 'var map = ...' above)
    google.maps.event.trigger(map, "resize");
  });
});
_x000D_
html,
body {
  height: 100%;
}
#map-canvas {
  min-width: 200px;
  width: 50%;
  min-height: 200px;
  height: 80%;
  border: 1px solid blue;
}
_x000D_
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<script src="https://maps.googleapis.com/maps/api/js?v=3.exp&dummy=.js"></script>
Google Maps resize demo
<div id="map-canvas"></div>
_x000D_
_x000D_
_x000D_

UPDATE 2018-05-22

With a new renderer release in version 3.32 of Maps JavaScript API the resize event is no longer a part of Map class.

The documentation states

When the map is resized, the map center is fixed

  • The full-screen control now preserves center.

  • There is no longer any need to trigger the resize event manually.

source: https://developers.google.com/maps/documentation/javascript/new-renderer

google.maps.event.trigger(map, "resize"); doesn't have any effect starting from version 3.32

What is difference between sjlj vs dwarf vs seh?

There's a short overview at MinGW-w64 Wiki:

Why doesn't mingw-w64 gcc support Dwarf-2 Exception Handling?

The Dwarf-2 EH implementation for Windows is not designed at all to work under 64-bit Windows applications. In win32 mode, the exception unwind handler cannot propagate through non-dw2 aware code, this means that any exception going through any non-dw2 aware "foreign frames" code will fail, including Windows system DLLs and DLLs built with Visual Studio. Dwarf-2 unwinding code in gcc inspects the x86 unwinding assembly and is unable to proceed without other dwarf-2 unwind information.

The SetJump LongJump method of exception handling works for most cases on both win32 and win64, except for general protection faults. Structured exception handling support in gcc is being developed to overcome the weaknesses of dw2 and sjlj. On win64, the unwind-information are placed in xdata-section and there is the .pdata (function descriptor table) instead of the stack. For win32, the chain of handlers are on stack and need to be saved/restored by real executed code.

GCC GNU about Exception Handling:

GCC supports two methods for exception handling (EH):

  • DWARF-2 (DW2) EH, which requires the use of DWARF-2 (or DWARF-3) debugging information. DW-2 EH can cause executables to be slightly bloated because large call stack unwinding tables have to be included in th executables.
  • A method based on setjmp/longjmp (SJLJ). SJLJ-based EH is much slower than DW2 EH (penalising even normal execution when no exceptions are thrown), but can work across code that has not been compiled with GCC or that does not have call-stack unwinding information.

[...]

Structured Exception Handling (SEH)

Windows uses its own exception handling mechanism known as Structured Exception Handling (SEH). [...] Unfortunately, GCC does not support SEH yet. [...]

See also:

Angular 2 optional route parameter

With angular4 we just need to organise routes together in hierarchy

const appRoutes: Routes = [
  { 
    path: '', 
    component: MainPageComponent 
  },
  { 
    path: 'car/details', 
    component: CarDetailsComponent 
  },
  { 
    path: 'car/details/platforms-products', 
    component: CarProductsComponent 
  },
  { 
    path: 'car/details/:id', 
    component: CadDetailsComponent 
  },
  { 
    path: 'car/details/:id/platforms-products', 
    component: CarProductsComponent 
  }
];

This works for me . This way router know what is the next route based on option id parameters.

how to parse JSON file with GSON

just parse as an array:

Review[] reviews = new Gson().fromJson(jsonString, Review[].class);

then if you need you can also create a list in this way:

List<Review> asList = Arrays.asList(reviews);

P.S. your json string should be look like this:

[
    {
        "reviewerID": "A2SUAM1J3GNN3B1",
        "asin": "0000013714",
        "reviewerName": "J. McDonald",
        "helpful": [2, 3],
        "reviewText": "I bought this for my husband who plays the piano.",
        "overall": 5.0,
        "summary": "Heavenly Highway Hymns",
        "unixReviewTime": 1252800000,
        "reviewTime": "09 13, 2009"
    },
    {
        "reviewerID": "A2SUAM1J3GNN3B2",
        "asin": "0000013714",
        "reviewerName": "J. McDonald",
        "helpful": [2, 3],
        "reviewText": "I bought this for my husband who plays the piano.",
        "overall": 5.0,
        "summary": "Heavenly Highway Hymns",
        "unixReviewTime": 1252800000,
        "reviewTime": "09 13, 2009"
    },

    [...]
]

How to get height of Keyboard?

Swift 3.0 and Swift 4.1

1- Register the notification in the viewWillAppear method:

NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillShow), name: .UIKeyboardWillShow, object: nil)

2- Method to be called:

@objc func keyboardWillShow(notification: NSNotification) {
    if let keyboardSize = (notification.userInfo?[UIKeyboardFrameEndUserInfoKey] as? NSValue)?.cgRectValue {
        let keyboardHeight = keyboardSize.height
        print(keyboardHeight)
    }
}

How to parse XML using vba

Often it is easier to parse without VBA, when you don't want to enable macros. This can be done with the replace function. Enter your start and end nodes into cells B1 and C1.

Cell A1: {your XML here}
Cell B1: <X>
Cell C1: </X>
Cell D1: =REPLACE(A1,1,FIND(A2,A1)+LEN(A2)-1,"")
Cell E1: =REPLACE(A4,FIND(A3,A4),LEN(A4)-FIND(A3,A4)+1,"")

And the result line E1 will have your parsed value:

Cell A1: {your XML here}
Cell B1: <X>
Cell C1: </X>
Cell D1: 24.365<X><Y>78.68</Y></PointN>
Cell E1: 24.365

C++ JSON Serialization

In case that anyone still has this need (I have), I have written a library myself to deal with this problem. See here. It isn't completely automatic in that you have to describe all the fields in your classes, but it is as close as what we can get as C++ lacks reflection.

nodeJS - How to create and read session with express

Steps I did:

  1. Include the angular-cookies.js file in the HTML!
  2. Init cookies as being NOT http-only in server-side app.'s:

    app.configure(function(){
       //a bunch of stuff
       app.use(express.cookieSession({secret: 'mySecret', store: store, cookie: cookieSettings}));```
    
  3. Then in client-side services.jss I put ['ngCookies'] in like this:

    angular.module('swrp', ['ngCookies']).//etc

  4. Then in controller.js, in my function UserLoginCtrl, I have $cookies in there with $scope at the top like so:

    function UserLoginCtrl($scope, $cookies, socket) {

  5. Lastly, to get the value of a cookie inside the controller function I did:

    var mySession = $cookies['connect.sess'];

Now you can send that back to the server from the client. Awesome. Wish they would've put this in the Angular.js documentation. I figured it out by just reading the actual code for angular-cookies.js directly.

How do I disable text selection with CSS or JavaScript?

You can use JavaScript to do what you want:


if (document.addEventListener !== undefined) {
  // Not IE
  document.addEventListener('click', checkSelection, false);
} else {
  // IE
  document.attachEvent('onclick', checkSelection);
}

function checkSelection() {
    var sel = {};
    if (window.getSelection) {
        // Mozilla
        sel = window.getSelection();
    } else if (document.selection) {
        // IE
        sel = document.selection.createRange();
    }

    // Mozilla
    if (sel.rangeCount) {
        sel.removeAllRanges();
        return;
    }

    // IE
    if (sel.text > '') {
        document.selection.empty();
        return;
    }
}

Soap box: You really shouldn't be screwing with the client's user agent in this manner. If the client wants to select things on the document, then they should be able to select things on the document. It doesn't matter if you don't like the highlight color, because you aren't the one viewing the document.

How to simulate a real mouse click using java?

Well I had the same exact requirement, and Robot class is perfectly fine for me. It works on windows 7 and XP (tried java 6 & 7).

public static void click(int x, int y) throws AWTException{
    Robot bot = new Robot();
    bot.mouseMove(x, y);    
    bot.mousePress(InputEvent.BUTTON1_DOWN_MASK);
    bot.mouseRelease(InputEvent.BUTTON1_DOWN_MASK);
}

May be you could share the name of the program that is rejecting your click?

How to test for $null array in PowerShell

If your solution requires returning 0 instead of true/false, I've found this to be useful:

PS C:\> [array]$foo = $null
PS C:\> ($foo | Measure-Object).Count
0

This operation is different from the count property of the array, because Measure-Object is counting objects. Since there are none, it will return 0.

Find and Replace text in the entire table using a MySQL query

The easiest way I have found is to dump the database to a text file, run a sed command to do the replace, and reload the database back into MySQL.

All commands below are bash on Linux.

Dump database to text file

mysqldump -u user -p databasename > ./db.sql

Run sed command to find/replace target string

sed -i 's/oldString/newString/g' ./db.sql

Reload the database into MySQL

mysql -u user -p databasename < ./db.sql

Easy peasy.

Why not inherit from List<T>?

There are some good answers here. I would add to them the following points.

What is the correct C# way of representing a data structure, which, "logically" (that is to say, "to the human mind") is just a list of things with a few bells and whistles?

Ask any ten non-computer-programmer people who are familiar with the existence of football to fill in the blank:

A football team is a particular kind of _____

Did anyone say "list of football players with a few bells and whistles", or did they all say "sports team" or "club" or "organization"? Your notion that a football team is a particular kind of list of players is in your human mind and your human mind alone.

List<T> is a mechanism. Football team is a business object -- that is, an object that represents some concept that is in the business domain of the program. Don't mix those! A football team is a kind of team; it has a roster, a roster is a list of players. A roster is not a particular kind of list of players. A roster is a list of players. So make a property called Roster that is a List<Player>. And make it ReadOnlyList<Player> while you're at it, unless you believe that everyone who knows about a football team gets to delete players from the roster.

Is inheriting from List<T> always unacceptable?

Unacceptable to who? Me? No.

When is it acceptable?

When you're building a mechanism that extends the List<T> mechanism.

What must a programmer consider, when deciding whether to inherit from List<T> or not?

Am I building a mechanism or a business object?

But that's a lot of code! What do I get for all that work?

You spent more time typing up your question that it would have taken you to write forwarding methods for the relevant members of List<T> fifty times over. You're clearly not afraid of verbosity, and we are talking about a very small amount of code here; this is a few minutes work.

UPDATE

I gave it some more thought and there is another reason to not model a football team as a list of players. In fact it might be a bad idea to model a football team as having a list of players too. The problem with a team as/having a list of players is that what you've got is a snapshot of the team at a moment in time. I don't know what your business case is for this class, but if I had a class that represented a football team I would want to ask it questions like "how many Seahawks players missed games due to injury between 2003 and 2013?" or "What Denver player who previously played for another team had the largest year-over-year increase in yards ran?" or "Did the Piggers go all the way this year?"

That is, a football team seems to me to be well modeled as a collection of historical facts such as when a player was recruited, injured, retired, etc. Obviously the current player roster is an important fact that should probably be front-and-center, but there may be other interesting things you want to do with this object that require a more historical perspective.

HashSet vs LinkedHashSet

All Methods and constructors are same but only one difference is LinkedHashset will maintain insertion order but it will not allow duplicates.

Hashset will not maintain any insertion order. It is combination of List and Set simple :)

Generate a unique id

Here is a 'YouTube-video-id' like id generator e.g. "UcBKmq2XE5a"

StringBuilder builder = new StringBuilder();
Enumerable
   .Range(65, 26)
    .Select(e => ((char)e).ToString())
    .Concat(Enumerable.Range(97, 26).Select(e => ((char)e).ToString()))
    .Concat(Enumerable.Range(0, 10).Select(e => e.ToString()))
    .OrderBy(e => Guid.NewGuid())
    .Take(11)
    .ToList().ForEach(e => builder.Append(e));
string id = builder.ToString();

It creates random ids of size 11 characters. You can increase/decrease that as well, just change the parameter of Take method.

0.001% duplicates in 100 million.

Convert double to float in Java

To answer your query on "How to convert 2.3423424666767E13 to 23423424666767"

You can use a decimal formatter for formatting decimal numbers.

     double d = 2.3423424666767E13;
     DecimalFormat decimalFormat = new DecimalFormat("#");
     System.out.println(decimalFormat.format(d));

Output : 23423424666767

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

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

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

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

             Date DF = new Date();


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

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

              }

output:- 15/03/2018
         15 Mar 2018

Open CSV file via VBA (performance)

This may help you, also it depends how your CSV file is formated.

  1. Open your excel sheet & go to menu Data > Import External Data > Import Data.
  2. Choose your CSV file.
  3. Original data type: choose Fixed width, then Next.
  4. It will autmaticall delimit your columns. then, you may check the splitted columns in Data preview panel.
  5. Then Finish & see.

Note: you may also go with Delimited as Original data type. In that case, you need to key-in your delimiting character.

HTH!

No templates in Visual Studio 2017

In my case, I had all of the required features, but I had installed the Team Explorer version (accidentally used the wrong installer) before installing Professional.

When running the Team Explorer version, only the Blank Solution option was available.

The Team Explorer EXE was located in: "C:\Program Files (x86)\Microsoft Visual Studio\2017\TeamExplorer\Common7\IDE\devenv.exe"

Once I launched the correct EXE, Visual Studio started working as expected.

The Professional EXE was located in: "C:\Program Files (x86)\Microsoft Visual Studio\2017\Professional\Common7\IDE\devenv.exe"


This solved my issue, and the reason was I had enterprise edition previously installed and then uninstalled and installed the professional edition. Team Explorer was not modified later when I moved to professional from enterprise edition.

What is content-type and datatype in an AJAX request?

From the jQuery documentation - http://api.jquery.com/jQuery.ajax/

contentType When sending data to the server, use this content type.

dataType The type of data that you're expecting back from the server. If none is specified, jQuery will try to infer it based on the MIME type of the response

"text": A plain text string.

So you want contentType to be application/json and dataType to be text:

$.ajax({
    type : "POST",
    url : /v1/user,
    dataType : "text",
    contentType: "application/json",
    data : dataAttribute,
    success : function() {

    },
    error : function(error) {

    }
});

How to split a string in Haskell?

Example in the ghci:

>  import qualified Text.Regex as R
>  R.splitRegex (R.mkRegex "x") "2x3x777"
>  ["2","3","777"]

How to make a smaller RatingBar?

I found an easier solution than I think given by the ones above and easier than rolling your own. I simply created a small rating bar, then added an onTouchListener to it. From there I compute the width of the click and determine the number of stars from that. Having used this several times, the only quirk I've found is that drawing of a small rating bar doesn't always turn out right in a table unless I enclose it in a LinearLayout (looks right in the editor, but not the device). Anyway, in my layout:

            <LinearLayout
                android:layout_width="wrap_content"
                android:layout_height="wrap_content" >
                <RatingBar
                    android:id="@+id/myRatingBar"
                    style="?android:attr/ratingBarStyleSmall"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:numStars="5" />
            </LinearLayout>

and within my activity:

    final RatingBar minimumRating = (RatingBar)findViewById(R.id.myRatingBar);
    minimumRating.setOnTouchListener(new OnTouchListener()
    { 
        public boolean onTouch(View view, MotionEvent event)
        { 
            float touchPositionX = event.getX();
            float width = minimumRating.getWidth();
            float starsf = (touchPositionX / width) * 5.0f;
            int stars = (int)starsf + 1;
            minimumRating.setRating(stars);
            return true; 
        } 
    });

I hope this helps someone else. Definitely easier than drawing one's own (although I've found that also works, but I just wanted an easy use of stars).

Apply function to each column in a data frame observing each columns existing data type

df <- head(mtcars)
df$string <- c("a","b", "c", "d","e", "f"); df

my.min <- unlist(lapply(df, min))
my.max <- unlist(lapply(df, max))

What is the "N+1 selects problem" in ORM (Object-Relational Mapping)?

Suppose you have COMPANY and EMPLOYEE. COMPANY has many EMPLOYEES (i.e. EMPLOYEE has a field COMPANY_ID).

In some O/R configurations, when you have a mapped Company object and go to access its Employee objects, the O/R tool will do one select for every employee, wheras if you were just doing things in straight SQL, you could select * from employees where company_id = XX. Thus N (# of employees) plus 1 (company)

This is how the initial versions of EJB Entity Beans worked. I believe things like Hibernate have done away with this, but I'm not too sure. Most tools usually include info as to their strategy for mapping.

Java, return if trimmed String in List contains String

You need to iterate your list and call String#trim for searching:

String search = "A";
for(String str: myList) {
    if(str.trim().contains(search))
       return true;
}
return false;

OR if you want to perform ignore case search, then use:

search = search.toLowerCase(); // outside loop

// inside the loop
if(str.trim().toLowerCase().contains(search))

java.sql.SQLException: No suitable driver found for jdbc:mysql://localhost:3306/dbname

An example of retrieving data from a table having columns column1, column2 ,column3 column4, cloumn1 and 2 hold int values and column 3 and 4 hold varchar(10)

import java.sql.*; 
// need to import this as the STEP 1. Has the classes that you mentioned  
public class JDBCexample {
    static final String JDBC_DRIVER = "com.mysql.jdbc.Driver"; 
    static final String DB_URL = "jdbc:mysql://LocalHost:3306/databaseNameHere"; 
    // DON'T PUT ANY SPACES IN BETWEEN and give the name of the database (case insensitive) 

    // database credentials
    static final String USER = "root";
    // usually when you install MySQL, it logs in as root 
    static final String PASS = "";
    // and the default password is blank

    public static void main(String[] args) {
        Connection conn = null;
        Statement stmt = null;

        try {
    // registering the driver__STEP 2
            Class.forName("com.mysql.jdbc.Driver"); 
    // returns a Class object of com.mysql.jdbc.Driver
    // (forName(""); initializes the class passed to it as String) i.e initializing the
    // "suitable" driver
            System.out.println("connecting to the database");
    // opening a connection__STEP 3
            conn = DriverManager.getConnection(DB_URL, USER, PASS);
    // executing a query__STEP 4 
            System.out.println("creating a statement..");
            stmt = conn.createStatement();
    // creating an object to create statements in SQL
            String sql;
            sql = "SELECT column1, cloumn2, column3, column4 from jdbcTest;";
    // this is what you would have typed in CLI for MySQL
            ResultSet rs = stmt.executeQuery(sql);
    // executing the query__STEP 5 (and retrieving the results in an object of ResultSet)
    // extracting data from result set
            while(rs.next()){
    // retrieve by column name
                int value1 = rs.getInt("column1");
                int value2 = rs.getInt("column2");
                String value3 = rs.getString("column3");
                String value4 = rs.getString("columnm4");
    // displaying values:
                System.out.println("column1 "+ value1);
                System.out.println("column2 "+ value2);
                System.out.println("column3 "+ value3);
                System.out.println("column4 "+ value4);

            }
    // cleaning up__STEP 6
            rs.close();
            stmt.close();
            conn.close();
        } catch (SQLException e) {
    //  handle sql exception
            e.printStackTrace();
        }catch (Exception e) {
    // TODO: handle exception for class.forName
            e.printStackTrace();
        }finally{  
    //closing the resources..STEP 7
            try {
                if (stmt != null)
                    stmt.close();
            } catch (SQLException e2) {
                e2.printStackTrace();
            }try {
                if (conn != null) {
                    conn.close();
                }
            } catch (SQLException e2) {
                e2.printStackTrace();
            }
        }
        System.out.println("good bye");
    }
}

Get bytes from std::string in C++

I dont think you want to use the c# code you have there. They provide System.Text.Encoding.ASCII(also UTF-*)

string str = "some text;
byte[] bytes = System.Text.Encoding.ASCII.GetBytes(str);

your problems stem from ignoring the encoding in c# not your c++ code

How to specify new GCC path for CMake

Change CMAKE_<LANG>_COMPILER path without triggering a reconfigure

I wanted to compile with an alternate compiler, but also pass -D options on the command-line which would get wiped out by setting a different compiler. This happens because it triggers a re-configure. The trick is to disable the compiler detection with NONE, set the paths with FORCE, then enable_language.

project( sample_project NONE )

set( COMPILER_BIN /opt/compiler/bin )
set( CMAKE_C_COMPILER ${COMPILER_BIN}/clang CACHE PATH "clang" FORCE )
set( CMAKE_CXX_COMPILER ${COMPILER_BIN}/clang++ CACHE PATH "clang++" FORCE )

enable_language( C CXX )

Use a Toolchain file

The more sensible choice is to create a toolchain file.

set( CMAKE_SYSTEM_NAME Darwin )

set( COMPILER_BIN /opt/compiler/bin )
set( CMAKE_C_COMPILER ${COMPILER_BIN}/clang CACHE PATH "clang" )
set( CMAKE_CXX_COMPILER ${COMPILER_BIN}/clang++ CACHE PATH "clang++" )

Then you invoke Cmake with an additional flag

cmake -D CMAKE_TOOLCHAIN_FILE=/path/to/toolchain_file.cmake ...

The type WebMvcConfigurerAdapter is deprecated

Use org.springframework.web.servlet.config.annotation.WebMvcConfigurer

With Spring Boot 2.1.4.RELEASE (Spring Framework 5.1.6.RELEASE), do like this

package vn.bkit;

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.ViewResolver;
import org.springframework.web.servlet.config.annotation.DefaultServletHandlerConfigurer;
import org.springframework.web.servlet.config.annotation.EnableWebMvc;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurerAdapter; // Deprecated.
import org.springframework.web.servlet.view.InternalResourceViewResolver;

@Configuration
@EnableWebMvc
public class MvcConfiguration implements WebMvcConfigurer {

    @Bean
    public ViewResolver getViewResolver() {
        InternalResourceViewResolver resolver = new InternalResourceViewResolver();
        resolver.setPrefix("/WEB-INF/");
        resolver.setSuffix(".html");
        return resolver;
    }

    @Override
    public void configureDefaultServletHandling(DefaultServletHandlerConfigurer configurer) {
        configurer.enable();
    }

}

How to set up default schema name in JPA configuration?

Don't know of JPA property for this either. But you could just add the Hibernate property (assuming you use Hibernate as provider) as

...

<property name="hibernate.default_schema" value="myschema"/>

...

Hibernate should pick that up

Should methods in a Java interface be declared with or without a public access modifier?

I prefer skipping it, I read somewhere that interfaces are by default, public and abstract.

To my surprise the book - Head First Design Patterns, is using public with interface declaration and interface methods... that made me rethink once again and I landed up on this post.

Anyways, I think redundant information should be ignored.

How to build a Horizontal ListView with RecyclerView?

Recycler View in Horizontal Dynamic.

Recycler View Implementation

RecyclerView musicList = findViewById(R.id.MusicList);

// RecyclerView musiclist = findViewById(R.id.MusicList1);
// RecyclerView musicLIST = findViewById(R.id.MusicList2);
LinearLayoutManager layoutManager = new LinearLayoutManager(this, LinearLayoutManager.HORIZONTAL, false);
musicList.setLayoutManager(layoutManager);

String[] names = {"RAP", "CH SHB", "Faheem", "Anum", "Shoaib", "Laiba", "Zoki", "Komal", "Sultan","Mansoob Gull"};
musicList.setAdapter(new ProgrammingAdapter(names));'

Adapter class for recycler view, in which there is is a view holder for holding view of that recycler

public class ProgrammingAdapter 
     extendsRecyclerView.Adapter<ProgrammingAdapter.programmingViewHolder> {

private String[] data;

public ProgrammingAdapter(String[] data)
{
    this.data = data;
}

@Override
public programmingViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
    LayoutInflater inflater = LayoutInflater.from(parent.getContext());
    View view = inflater.inflate(R.layout.list_item_layout, parent, false);

    return new programmingViewHolder(view);
}

@Override
public void onBindViewHolder(@NonNull programmingViewHolder holder, int position) {
    String title = data[position];
    holder.textV.setText(title);
}

@Override
public int getItemCount() {
    return data.length;
}

public class programmingViewHolder extends RecyclerView.ViewHolder{
    ImageView img;
    TextView textV;
    public programmingViewHolder(View itemView) {
        super(itemView);
        img =  itemView.findViewById(R.id.img);
        textV =  itemView.findViewById(R.id.textt);
    }
}

UITextField border color

Import QuartzCore framework in you class:

#import <QuartzCore/QuartzCore.h>

and for changing the border color use the following code snippet (I'm setting it to redColor),

    textField.layer.cornerRadius=8.0f;
    textField.layer.masksToBounds=YES;
    textField.layer.borderColor=[[UIColor redColor]CGColor];
    textField.layer.borderWidth= 1.0f;

For reverting back to the original layout just set border color to clear color,

    serverField.layer.borderColor=[[UIColor clearColor]CGColor];

in swift code

    textField.layer.borderWidth = 1
    textField.layer.borderColor = UIColor.whiteColor().CGColor

Height of status bar in Android

Thanks to @Niklas +1 this is the correct way to do it.

public class MyActivity extends Activity implements android.support.v4.View.OnApplyWindowInsetsListener {

    Rect windowInsets;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        setContentView(R.layout.my_activity);

        View rootview = findViewById(android.R.id.content);

        android.support.v4.View.ViewCompat.setOnApplyWindowInsetsListener(rootview, this);
    }

    android.support.v4.View.WindowInsetsCompat android.support.v4.View.OnApplyWindowInsetsListener.OnApplyWindowInsets(View v, android.support.v4.View.WindowInsetsCompat insets)
    {
        windowInsets = new Rect();
        windowInsets.set(insets.getSystemWindowInsetLeft(), insets.getSystemWindowInsetTop(), insets.getSystemWindowInsetRight(), insets.getSystemWindowInsetBottom());
        //StatusBarHeight = insets.getSystemWindowInsetTop();

        //Refresh/Adjust view accordingly

        return insets;
    }
}

Please excuse me if the code isn't 100% correct, converted it from Xamarin C# but this is the just of it. Works with Notches, etc.

Eclipse: Enable autocomplete / content assist

  1. window->preferences->java->Editor->Contest Assist
  2. Enter in Auto activation triggers for java:
    abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ._
  3. Apply and Close

other method:
type initial letter then ctrl+spacebar for auto-complete options.

Playing sound notifications using Javascript?

First things first, i'd not like that as a user.

The best way to do is probably using a small flash applet that plays your sound in the background.

Also answered here: Cross-platform, cross-browser way to play sound from Javascript?

sh: 0: getcwd() failed: No such file or directory on cited drive

That also happened to me on a recreated directory, the directory is the same but to make it work again just run:

cd .