Programs & Examples On #Thunk

A parameterless closure (functional programming) or a function generated by a compiler to aid runtime linking with a dynamic library function.

Error: the entity type requires a primary key

This exception message doesn't mean it requires a primary key to be defined in your database, it means it requires a primary key to be defined in your class.

Although you've attempted to do so:

private Guid _id;
[Key]
public Guid ID
{
    get { return _id; }
}

This has no effect, as Entity Framework ignores read-only properties. It has to: when it retrieves a Fruits record from the database, it constructs a Fruit object, and then calls the property setters for each mapped property. That's never going to work for read-only properties.

You need Entity Framework to be able to set the value of ID. This means the property needs to have a setter.

npm start error with create-react-app

I solve this issue by running following command

echo fs.inotify.max_user_watches=524288 | sudo tee -a /etc/sysctl.conf && sudo sysctl -p

hope it helps

React eslint error missing in props validation

I ran into this issue over the past couple days. Like Omri Aharon said in their answer above, it is important to add definitions for your prop types similar to:

SomeClass.propTypes = {
    someProp: PropTypes.number,
    onTap: PropTypes.func,
};

Don't forget to add the prop definitions outside of your class. I would place it right below/above my class. If you are not sure what your variable type or suffix is for your PropType (ex: PropTypes.number), refer to this npm reference. To Use PropTypes, you must import the package:

import PropTypes from 'prop-types';

If you get the linting error:someProp is not required, but has no corresponding defaultProps declaration all you have to do is either add .isRequired to the end of your prop definition like so:

SomeClass.propTypes = {
    someProp: PropTypes.number.isRequired,
    onTap: PropTypes.func.isRequired,
};

OR add default prop values like so:

SomeClass.defaultProps = {
    someProp: 1
};

If you are anything like me, unexperienced or unfamiliar with reactjs, you may also get this error: Must use destructuring props assignment. To fix this error, define your props before they are used. For example:

const { someProp } = this.props;

How do I access store state in React Redux?

You need to use Store.getState() to get current state of your Store.

For more information about getState() watch this short video.

Pros/cons of using redux-saga with ES6 generators vs redux-thunk with ES2017 async/await

One quick note. Generators are cancellable, async/await — not. So for an example from the question, it does not really make sense of what to pick. But for more complicated flows sometimes there is no better solution than using generators.

So, another idea could be is to use generators with redux-thunk, but for me, it seems like trying to invent a bicycle with square wheels.

And of course, generators are easier to test.

Why do we need middleware for async flow in Redux?

When working in an enterprise project, there are many requirements available in middle-ware such as (saga) not available in simple asynchronous flow, below are some:

  • Running request in parallel
  • Pulling future actions without the need to wait
  • Non-blocking calls Race effect, example pickup first
  • response to initiate the process Sequencing your tasks (first in first call)
  • Composing
  • Task cancellation Dynamically forking the task.
  • Support Concurrency Running Saga outside the redux middleware.
  • Using channels

The list is long just review the advanced section in saga documentation

Java: Convert String to TimeStamp

first convert your date string to date then convert it to timestamp by using following set of line

Date date=new Date();
Timestamp timestamp = new Timestamp(date.getTime());//instead of date put your converted date
Timestamp myTimeStamp= timestamp;

How can I set the opacity or transparency of a Panel in WinForms?

Yes, opacity can only work on top-level windows. It uses a hardware feature of the video adapter, that doesn't support child windows, like Panel. The only top-level Control derived class in Winforms is Form.

Several of the 'pure' Winform controls, the ones that do their own painting instead of letting a native Windows control do the job, do however support a transparent BackColor. Panel is one of them. It uses a trick, it asks the Parent to draw itself to produce the background pixels. One side-effect of this trick is that overlapping controls doesn't work, you only see the parent pixels, not the overlapped controls.

This sample form shows it at work:

public partial class Form1 : Form {
    public Form1() {
        InitializeComponent();
        this.BackColor = Color.White;
        panel1.BackColor = Color.FromArgb(25, Color.Black);
    }
    protected override void OnPaint(PaintEventArgs e) {
        e.Graphics.DrawLine(Pens.Yellow, 0, 0, 100, 100);
    }
}

If that's not good enough then you need to consider stacking forms on top of each other. Like this.

Notable perhaps is that this restriction is lifted in Windows 8. It no longer uses the video adapter overlay feature and DWM (aka Aero) cannot be turned off anymore. Which makes opacity/transparency on child windows easy to implement. Relying on this is of course future-music for a while to come. Windows 7 will be the next XP :)

AttributeError: 'module' object has no attribute 'model'

As the error message says in the last line: the module models in the file c:\projects\mysite..\mysite\polls\models.py contains no class model. This error occurs in the definition of the Poll class:

class Poll(models.model):

Either the class model is misspelled in the definition of the class Poll or it is misspelled in the module models. Another possibility is that it is completely missing from the module models. Maybe it is in another module or it is not yet implemented in models.

Reactjs: Unexpected token '<' Error

For correct tag parsing you'll need to use this babel version : https://cdnjs.cloudflare.com/ajax/libs/babel-core/5.8.24/browser.js and attribute "type='text/babel'" in the script. Besides, your custom script should be within "body" tags.

How to delete specific columns with VBA?

You were just missing the second half of the column statement telling it to remove the entire column, since most normal Ranges start with a Column Letter, it was looking for a number and didn't get one. The ":" gets the whole column, or row.

I think what you were looking for in your Range was this:

Range("C:C,F:F,I:I,L:L,O:O,R:R").Delete

Just change the column letters to match your needs.

submit a form in a new tab

<form target="_blank" [....]

will submit the form in a new tab... I am not sure if is this what you are looking for, please explain better...

Javascript: How to loop through ALL DOM elements on a page?

Here is another example on how you can loop through a document or an element:

function getNodeList(elem){
var l=new Array(elem),c=1,ret=new Array();
//This first loop will loop until the count var is stable//
for(var r=0;r<c;r++){
    //This loop will loop thru the child element list//
    for(var z=0;z<l[r].childNodes.length;z++){

         //Push the element to the return array.
        ret.push(l[r].childNodes[z]);

        if(l[r].childNodes[z].childNodes[0]){
            l.push(l[r].childNodes[z]);c++;
        }//IF           
    }//FOR
}//FOR
return ret;
}

Assign output to variable in Bash

In shell, you don't put a $ in front of a variable you're assigning. You only use $IP when you're referring to the variable.

#!/bin/bash

IP=$(curl automation.whatismyip.com/n09230945.asp)

echo "$IP"

sed "s/IP/$IP/" nsupdate.txt | nsupdate

What is the purpose of backbone.js?

It also adds routing using controllers and views with KVO. You'll be able to develop "AJAXy" applications with it.

See it as a lightweight Sproutcore or Cappuccino framework.

How to automatically crop and center an image

I created an angularjs directive using @Russ's and @Alex's answers

Could be interesting in 2014 and beyond :P

html

<div ng-app="croppy">
  <cropped-image src="http://placehold.it/200x200" width="100" height="100"></cropped-image>
</div>

js

angular.module('croppy', [])
  .directive('croppedImage', function () {
      return {
          restrict: "E",
          replace: true,
          template: "<div class='center-cropped'></div>",
          link: function(scope, element, attrs) {
              var width = attrs.width;
              var height = attrs.height;
              element.css('width', width + "px");
              element.css('height', height + "px");
              element.css('backgroundPosition', 'center center');
              element.css('backgroundRepeat', 'no-repeat');
              element.css('backgroundImage', "url('" + attrs.src + "')");
          }
      }
  });

fiddle link

What is difference between cacerts and keystore?

'cacerts' is a truststore. A trust store is used to authenticate peers. A keystore is used to authenticate yourself.

HTML5 Canvas Rotate Image

Here is Something I did

var ImgRotator = {
    angle:parseInt(45),
    image:{},
    src:"",
    canvasID:"",
    intervalMS:parseInt(500),
    jump:parseInt(5),
    start_action:function(canvasID, imgSrc, interval, jumgAngle){
        ImgRotator.jump = jumgAngle;
        ImgRotator.intervalMS = interval;
        ImgRotator.canvasID = canvasID;
        ImgRotator.src = imgSrc ;
        var image = new Image();
        var canvas = document.getElementById(ImgRotator.canvasID);
        image.onload = function() {
            ImgRotator.image = image;
            canvas.height = canvas.width = Math.sqrt( image.width* image.width+image.height*image.height);
            window.setInterval(ImgRotator.keepRotating,ImgRotator.intervalMS);
            //theApp.keepRotating();
        };
        image.src = ImgRotator.src;   
    },
    keepRotating:function(){
        ImgRotator.angle+=ImgRotator.jump;
        var canvas = document.getElementById(ImgRotator.canvasID);
        var ctx = canvas.getContext("2d");
        ctx.save();
        ctx.clearRect(0,0,canvas.width,canvas.height);
        ctx.translate(canvas.width/2,canvas.height/2);
        ctx.rotate(ImgRotator.angle*Math.PI/180); 
        ctx.drawImage(ImgRotator.image, -ImgRotator.image.width/2,-ImgRotator.image.height/2);
        ctx.restore();
    }
}

usage

ImgRotator.start_action("canva",
            "data:image/jpeg;base64,/9j/4AAQSkZJRgABAQAAAQABAAD/2wCEAAkGBxIQEhUSEhMVFhUVFRUVFRUVFRcVFRUQFRUWFhUVFRUYHSggGBolGxUVITEhJSkrLi4uFx8zODMsNygtLisBCgoKDg0OFhAQFy0lIB8rLS4tLS0rLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tKy0tKy0tLS0tLS0rLS0tLS0rLf/AABEIAL0BCgMBIgACEQEDEQH/xAAcAAACAgMBAQAAAAAAAAAAAAABAgADBAYHBQj/xAA9EAACAQIDBgMGAwYGAwEAAAABAgADEQQSIQUTMUFRYQYicQcygZGh8BRCsSNSwdHh8RUzYnKCkmOywkP/xAAZAQEBAQEBAQAAAAAAAAAAAAAAAQMCBAX/xAAkEQEAAwACAwACAQUAAAAAAAAAAQIRAyESMUETIlEEFDJhgf/aAAwDAQACEQMRAD8A34SWl+5PSEUD0nbFQBJYzI3J6QNRtARFtG1kCxgveQLl+7xwIDGCwJaNTe0gWNu4Ad7xI7LzM5n428dFWNHDEXGjN0ETK1jXQa+2aVEXeoqjuZ5dXxzgCbfiE+f8ZwTHYt6pzVHJPc/p0mEexnPk0/HD6OpeJsG/u16R/wCa/wAJ6NDGKT5XU+hE+YlqsvpPb2P4ir0iN3VYW/KTmT/qdJPJfxxL6JeveV2ml+EvHNPEMKVcCnUOim/kc9AeTdj9ZvDJ2M6idZWrMdSSCPaSUKJDDaW0qd4FIjTKWlY8YzpeDWHDL6lK0otAEgjW+7RdYEMBEdVj7mBQYDMjdQbqMNUrUIiljMncwbgRhqsVTF3x7RgkRqX3eVyb8Qe0Bqkxd196RkpwJaS0bJCqQpI4jBYbSBN5aT8TGaneeV4lxBw2FrVv3KbMNfzW8v1tKNE9oHjqoKrYXDEBV8tSpxOfmi8hbn305a8wq1uPfX+8Ck2JOvMkm5JPEk8zrMao3OZt4jBZ+silOY+plAHWOAveFZaUVPuNr0bh8xEakRraxHEfygogE6T01oNa9viNR8RxAkWIXbOs4AJ/2noeU6D4Q8bNRtQxRJXglU3Nh/q56df7zn2Fp5Qbfm1X4e8h73tb4x6eL11+z2k3J6dZ5RkvoelUVlDKQQdQQbgjsYSZy7wZ4lNGyMb0/wAy34dXQdRzWdSpMGAZSCrAEEcCDqCJpE689q+MoJA5WWZIpSVwn4gw78wBIMn3eUFqpMUfesYU/SMEkUloLfd5YV9IMvpArJgzmW5e8G77/SBUXMAc9Zaaff6RTTgQ1D1i7w9Y279ZN1AQVRAagijDiK1AS4mrN6JN4JQaHrGWiOp+UYmrt4IN6IRQEIw69IXQ3ohWoJPw69IdwvT9JARVE597ZdpFMJTorwrVfN/tp2a3/bL8pv7YcTmvtrw+XD4dv/Mw+dNj/wDP0iXVfblFMk3EY4Qkd4uG1abPs/ZpYAk3BmVr+L0Up5NW/AP0jHDsJ0zDbLXLa395h7Q2CBqJj+Z6P7eI+ueZPSets+pl0yn4HQ/SW7S2WVmBh67IdCb/AEPwmtbaytTxZzVxcixGuo5g9R3lVRM3Djz7jr6QYmuSQWHcMJFNrHly/lCDh8U1Mg66cDzB/j8Z1r2abeFVWog6KM6jXyi9mUdACRYd5yrKHvYj0PP4cv0lmx9o1MFWWtSNiOKn3XXmp6gxHUpaPKH0ZvBA1QTz9iY+li6KVqfBhwPFW5qe4MzXoibPLPRjUEArCIKAh3AjE04qjtDve8rWgIdyIw029HWHeCV7gSbj7tGLq3PBvBKmww6xfw/eMNXmqIu9EqNHvBue5jDV++g3spNDuYm57mDWTaI4lmkGUTpyqymMolgQQ5RAUGMBABGEgkIEkIgK4nOfbUAcHT6rXU/DI6n/ANp0sqJyX2t7TD3wqj3AtS5/MSb2HwA+c5tMRDulZmenMNn0yzC03/ZVI5BNQ8N0blj0t9ZsdPDbweauaZHAAaD1POebl7nHv4f1rrccFh9JnvgQRac+bHYqh/l4lKoHIsL6dj/ObB4d8TVKzhKqZTa9wND1mU0xrF/LpbtTYOYaTne3dmNRbWdg2rid3TL2vZSbde05Z4gxtfEXLhaacr6Ej46mdcftzy+u3jU6wZcp9fvvLqdTQA/YnnJYaA3mRSc8Pv4T0fXm9wuLW1B/pLPxObjofoZjst+EqZTzk9r6dH9lO3DTrNhifLU1UHlUA5eo/SddJnz54OF8Vhct8++1I/dAFv0Pzn0KiaD0mlPTDl96QCQy3dd5N13mjFUITHKWgkUpvBGMggVtDaW7u/ODdd4FRglu67yCkOsCuIZkbsdYu7HWBVeS8GSQLK5NeQQZZLQpowMQCPaAYQvaKIwkC1WsCToACT6CfN+K2wcVi6rtqKrNl7DXL8LX+c7b7RNpfh8BXcGzMmRT/qfyj9TPnNXKkMOIII9ROLxsY24pydbR4aTKzDqR8tZn7W8P1C4qAFkvcqL8O5HATC2WRmV191hf0PMToWwqmYC88lrTFtfQpSLVxpH+EbyoxWmqKzKci2BAGhC1b5gDrcc/UCerhdk1MO1Jyb+axtcA3Omh5248p0gU1I5TXNovvK4TSym/x+zJbkmYWvHFZ6ertWjnpKo0zTn21/D1Xz51FS6kLbNZOjf6j6zpeL91e2sNJA9ric0t4u708vb5/wAbs2ojEsLa3va2sqD9RrO77Z2BTqrYqPXnOM+LtnHC1QvI3t6TanJ5TkvPfi8a7DFc+v0MrLn7MmHqg8Len8jzjv3H10mrFuHsooCrjwTxpK7nuTZB8fNO5Cck9jtFd9WqcwgUd7sM3ysP+wnXBNK+mHJ7QSSLIROmYSWhgMAQ2ktJAEFj1jXgJgAwQwQAYIbSfCFPlhCxRUh33aVwYp92jKlpXv8AtDvoCt96QgwXgJtIprwrBJeBzP2640rRoUh+dyx9FH8yPpOMg6GdM9uWKG8oUrebKzs1+A0ULbpoTOZqPL8ZzPttX02jZOGelTpZrWc1gLG5VkyEq3Q+e/zm3bEx+XQ8pqeFxQOFYk+ak9Gv3K64ev8A+yt8BNo2CVYg6a/rPFyPfwT8e4ds5wVT5zW6uPr4Z1LqCma5bnYmTxThK9B1rUG8hsHXmLaXXr6T0tlbPxOICmm9Gpmy/wD6G6h1LDMMpsfLwitNjW02r9nHsptx66Dc0w9v3myj0vYzIqPURc1gG45Qbj0vFXA4unT81NAFzXtUXTLe7chbSeQMRiqtYUlAyC+8csDa2lhbifpJNJhYms+pepQ8Qh1N+I0I5g95yzx9jd7X0/KLfM6/oJ0fatGnRR352v3NhYTkG06l6hY662/WXhj9tZf1Fv1xjUReZ1O4tp8YhwLA6cbXHcSyjjmX+Inpl5Ie/wCHPEZwVZHAJTTMo45SLN69bdQOk7vsvaFLE01q0XDowuGH1B5g9QdRPmxmBHDT9J1r2O7siqAzXy0yQx/MCwJsNDby68bEA8JaS45a9a6MqwMJeABDlBmrzsW0mWWVAAYlhAW0IhIkgWZIoSOrCS4lQrpFVJZcSZxAR1ibuWlx1g3g6iFYoimWCI4hEEIEW0IlRYLw2gEaxkUicOf9oj1lA1P00+calw9b8+8w62KVQyVSFFiLt7pHW/C+vC9/1kVx7GJTx+JxNXE3CqlR8wBO7RMyiwGrEHKbDob2mgW/pNqbENTq4mkhLZlNPMdboTcmx5HSa1jKeW4+X8TOG0Q9R9h4j8Ga4VsrspFidaRGhaxsBccCNcwN9ADkeHdpmnZWPa8vw/j+pToiglBQmQIwL3VgtreXLwuL2148Z41CqtUlhYEknLwtc8BPPlpifKG9JiJjJdOZ9/Ste9+HrMbZ1MoRmp5sp0ZTkqD4ix+U1bYm2WoNZrlf0nSdl4ulVUMpU39Jls1e6l+lKDeLlFM8Sb1GZrE8TZiTfUz1MDhhRU39SZlUsTTA1yiab4w8WKqtTonMx0JHBfjzMk2myzbp5Xi/bOdjSQ3Y30HLrNF2nhzTsje8fNoQdNLaj4x0xZVy5bU6EnXvwse0xcbjC51N+9gOw0no46eLw8t/KWXTxBKgdBp8zMcXbX0goi5HK5ue3WenVqIlMBV1J4np37zrXMMJahUcLifQXhbY9KmlLEUVy7ylTzAaArkBvbqTY3nGj4fqOMLQykVMQbi/EBrWJHQKS2vefQeDo7tFpjgihR/tUAD6Cd0hjyz6XgQEx4pmrABJIPhJeRUvJDFgQ/esBEYQMZUIYBGMUGBGlccwW7yKgitGEVmlchCsF4yyiwGNEEMisTG4oUQWIJB6Ak3J6DU3J5dZom3fF+HRiprAEXuqi7XHJ2AuvTKuvVhPS9oOJYUamUkWpsFtxzsQlx042v0Y/Dk+PbDU8LSWlRvVZQa1V2JysSwC01BsoOUm5B0t6ziZaVqpxe11avUqKmZXBGUkgHzaXIF7WA4WJ68Z5GPxBqMS3HnbQDoABwAGlpXvCeGnf+EQJfQf1khpLJw2zWrDyMuYfkPlutgQQ50BN+Bty11tMTE4R6TZXUqw5H9QRoR3Gk9nD4qp5QrN5TmUEhggHmsqHQi4BtbX4zZ6FOltCj/lKHQM1RFfKQgUHeUVIJ4AmwNhkYEMbTmbTBEa0Kjj3Xj5h34/Oe5szaiH8+7PQmw+B4TH2p4ddCTS/aLc6L5qijuo98D95fUhZ4QktStmleS1W9VUqH87EdySJj1cNZSzfCeR4d2pu23dQndnhzyHqO3abJ4gw+XDs4a4y3B63GlvnPNNJraIeuvJW9ZmPjSkXOSepMysBhFVi1XgvBR+Zv5TCwlUowI5fpMyq5Os9U9PHHa/FFeKjuf6/GXVCuTMdTawHThr+p+Ex6VTKSTqLAMD+6bfLXW8zsPhwV6obG/Q9D0M5dN22N4hWvicNjPzUlCVqYBJ3ZD03dOts6vYa2VtNBfrtGqrgMpBUi4KkEEHgQRxE+bEc0XDUyQe2t7dufxnVPBOPr0MgqkNRrHyOLgZzfh0PVfUjgZpSWPJV0SKT2jCAzVgUH1hvJYQWE5UZLiQW7wGBNJM0U3glQSYtoTIBABMXN92jNK7QMi6xfLAEMEBiBAVEgMhMBbSPpIX7GAC+p+UDnPtGxFV6i4ZAtPyb1qr31DFiUSwNyMl9egnL8ZSVEqhjd81EqTzUrUzgcuJUf8AGfRO1dmpXAzDzLcqw95SbXt14DTnPnDxQ6jE1UQqyo7KGX3WseI1nEx21pPTAvfQafepJm07F8PowVmrBW4hR7yupI8/lJXXXQaaes04mAacJzaJn1LuOm+1PDFMNZq6JULEBgxNPOAT+0AUFODcNOGmtpg1cHUoWZiDmuLJb3OBKtoGU2sVueGoHLwMJtitTBGYsrAB1Yk5lBBtfjbQfIdBbbtm7Qw9eiVs2YL5l8iqpUHJl4LcnLrprfqRM5i0O/1l6FFFpUA28yMWXd5mKhWsmWxFtSPNYX0NzwNrKOzqWOdRWoJUqVb5GVjTqM66ENUUKWPlOrqdLcLiYtFc1EU2/aAqCnRxxBXNqrgWA5AKBz1GxsccO2V/dptZi4I1KkAWC5szB1Fzwvw5znv4vXTxPEHhynRPkzJqQcxLKLAcRq3G99bjpbhmVcO52UQxBKkgFWDApnDCxHYkfCe9Va7/ALNXPvA52Kgs1xSGUaFSEGpzaaWBsJifh1CvRCMquzHkEDg5Sqea/JTYCw6LcAS1pmI/0044yc/npzqkBMylY6coMTgGpswPBTa/6SzZwGoPMG3qNf0vNZnY1nEZOFxVIqQeXD1HET2/DlN6rinTpiqWBG7JClhYkgMSLcCb3EwnqBltx5H+BE97wnSrUa9N8OuY1Gakgv8AnVUYknkLOddeEQW6eXi9nNvfwyZt4ai0hmWzB3IC5l5e8P6gz6Co7Jp7rdFAU00I6AAHsdBPB8LeCVwzCvWYVK1y5PECo3Fsx1Y9OA7X1m4X7zSsY897aSlSyiwvppqST8zqZGQ9I+aAuZ2zVlYLRiTJcyKSNeGSALQZT9iWh4DUgUkQ27S3eQb6BURJY9JaavaDedoDBoCB0i2bpJr0nTk2Ud4Mg7/OC56SFz0gNkEV8oFzf4an5CDP2k3nb6wObe1rxmMPR/C4cuK1YedirIadC5By5gDdiCARwAbnacQnteMNtfj8ZWxGuVmtTvyor5aenK4GYjqxnjTOW8RkBJeCECFES7DYg0zmAuOangRx+B6HlKpBA6PgMaxwp3dNWyDNSdLgM1grKwC+Virg+tM8LyYmjvaa1qZ98Lo4ujF1YumYC4uRa2pUst7XJi+zfago4atcKzI5KhrEHMqnVTxUBDpY8+ulfhii1RqmHcEWZmCqL5FYBi6jkBc63OjacRPP6mWv8POwWJNN8tQt5WXiLe8xvlsp5uTwNtewnsY/FpQotUBzZQjEDKf2hy5WvrdrlRfXRgepmY1Jt4KWQKzqAA7f5tUqcgsfzG9r3setyZRTwmFqYerh2R6bABWdgWy1bqzW18qBgmnG3UXtN2dlcz01aspr0zWFje2YDgj8LW48QSL8iJ5NG4P1+k2jwzUXC4iphKlNmSqoZM3vrwYMw0BBVTy4EW4mZ23PCG7DFb3FzrxGtyD98pZv4zku4r5xse2p0DYk9v6H6Tsfs52E7CjXZbU6NNlpEizVKlRnZ6gH7oVwoPM5jwsTzbZuCDjy2zWcpmsAtVBfdsebadNVNxwNut+zHagqYdqebNlOZb3uoOjUyCdMrgi3IEep7457xly/4tx3Rg3ZlmeDNPQ8hd1AaRjwQqrdnpJkPSXXhvIKMh6SZOxl94LwKcp6QFZfeSBRlhWleWn71kgUMtoLzI+MkCoVTFbEWlCmAidOV/4iKa15RCogWieN42xZo7PxdRTZhQqAHozKVB+BM9i01b2o11TZeJubZwiL3ZqiWHyv8LySse3zsosIhj1DEE4boBLAJFEJgI0KiKY3KBsHhTalKhmFQjVswDDytZfcLcgeHxOs2vZ7gVKtXMxoFFcWHkJppdiQVNmCtcheNgb2FxzIzbPD+3kSmlJ3yW817MAXQtkBZdR+Vrgjhl4TK9PsNK2+S3B67qEZcjqrozUzbNxdDa44Zip0HIWNpgbUApK+Wo27K57LnNVQtNc1J8qksp3d7NawF+FyMXxHtGjQp2DLUzBcgRlykgHJVsBYroGtYAXAFrT0/C2MTE0gMo94uyhsxR7DMaa6W1N8pvo1tRpMp2I3HcZPWuc7V2gtWoKtJd2dT5bgk5iQeJA0NrDSwnWfA+2f8RplXy5+lwMzD3wAT6N6N2M5Z4qwP4fF1qZsCragZvKxAuDn1Jvz4G9xM3wLtoYTEqWW4YgXAGZW1CkHjlu2ouPpNb0i1XFLzWzquJ8JbzCVGKFaqPWuF99qauSuW35xbMp14kcGM13wZtQYPE7+qyilVy0KwX3EdtKOIzFicr5Fv0Di5Np0nZG0lqMHFwtZQ1jxWqBZlI5G4PymieNtgpQrMzIxoVVawBJGYks9Mrzyn9og1IBcKPKJxWc/4to3d+usZR0lopDpNF9mfiM1qbYOs96+F8oa+tbCiwpVh10yg8eRPGbrvDPVE68kxi8IIhoiIKhhNQwhSg+zFKD7MaAShco6n5whO5+cb75Q3gTddzAaZ6mOKkm+7SCvdnqZMh6mOa0O9gVFG6yZW6mWGtJvYGGtpD6xgsDJOkJbvABLAtpFhEE5J7ctsqTQwam5UmvU/wBJKlKQ9bGofQjrOvz5T2xtN8XXqYip71Vy57A+6o7AWA9JzLSkMRpFEEcDWctT2isY0rMCAQyARSYEMkEMCWl+GxT0zmRiOo5Hsw5jUygRlgZu19pHEuKjCzZQG1JzEX1uxJOlhr0HHjMMHiDz/WLIYzB07wB4napkov7ykKG1ANQ/5TOeAzW3ZJ55OF503aBFak1OsBoAGtya+hF+YNiJ87+GbHE00N7VWFI2ZltnIAN1IJsbG1xw5TvGLrMcEtW5zMVzE6k2JXUi3S88948Z6bUnfbnGLp19m4tMSigHDFi6gkGth2I3lMDXyhCzqToFZea2nccLiFqotRGDI6q6MOBRgCp+RE0jxfhRUoYZzoXLUmtzptSckHqLZx/zvxAnr+zlj/h9JSb7tq9Jb8clKvUppf8A4qB8Jtxz8Y8sfWzARTGimasEkhEkigIZLwwFtAYwMhlRWYYxWS0ikMEa0lpR/9k=",
            500,15
            );

HTML

<canvas id="canva" width="350" height="350" style="border:solid thin black;"></canvas>

Get value from a string after a special character

You can use .indexOf() and .substr() like this:

var val = $("input").val();
var myString = val.substr(val.indexOf("?") + 1)

You can test it out here. If you're sure of the format and there's only one question mark, you can just do this:

var myString = $("input").val().split("?").pop();

CSS float right not working correctly

Verry Easy, change order of element:

Origin

<div style="">

    My Text

    <button type="button" style="float: right; margin:5px;">
       My Button
    </button>

</div>

Change to:

<div style=""> 

    <button type="button" style="float: right; margin:5px;">
       My Button
     </button>

   My Text

</div>

How to concatenate columns in a Postgres SELECT?

As i was also stuck in this, think i should share the solution that worked best for me. I also think that this is much simpler.

If you use Capitalized table name.

SELECT CONCAT("firstName", ' ', "lastName") FROM "User"

If you use lowercase table name

SELECT CONCAT(firstName, ' ', lastName) FROM user

That's it!. As PGSQL counts Double Quote for column declaration and Single Quote for string, this works like a charm.

setup script exited with error: command 'x86_64-linux-gnu-gcc' failed with exit status 1

Try installing these packages.

sudo apt-get install build-essential autoconf libtool pkg-config python-opengl python-pil python-pyrex python-pyside.qtopengl idle-python2.7 qt4-dev-tools qt4-designer libqtgui4 libqtcore4 libqt4-xml libqt4-test libqt4-script libqt4-network libqt4-dbus python-qt4 python-qt4-gl libgle3 python-dev libssl-dev

sudo easy_install greenlet

sudo easy_install gevent

jQuery move to anchor location on page load

Did you tried JQuery's scrollTo method? http://demos.flesler.com/jquery/scrollTo/

Or you can extend JQuery and add your custom mentod:

jQuery.fn.extend({
 scrollToMe: function () {
   var x = jQuery(this).offset().top - 100;
   jQuery('html,body').animate({scrollTop: x}, 400);
}});

Then you can call this method like:

$("#header").scrollToMe();

How can I specify my .keystore file with Spring Boot and Tomcat?

If you don't want to implement your connector customizer, you can build and import the library (https://github.com/ycavatars/spring-boot-https-kit) which provides predefined connector customizer. According to the README, you only have to create your keystore, configure connector.https.*, import the library and add @ComponentScan("org.ycavatars.sboot.kit"). Then you'll have HTTPS connection.

Could not calculate build plan: Plugin org.apache.maven.plugins:maven-resources-plugin:2.6 or one of its dependencies could not be resolved

I had a similar problem in spring tool suite(sts). THE .m2 repository was not completely downloaded in the local system which is the reason why I was getting this error. So I reinstalled sts and deleted the old .m2 repository from the system and created a new maven project in sts which downloaded the complete .m2 repository. It worked for me.

Preferred Java way to ping an HTTP URL for availability

Instead of using URLConnection use HttpURLConnection by calling openConnection() on your URL object.

Then use getResponseCode() will give you the HTTP response once you've read from the connection.

here is code:

    HttpURLConnection connection = null;
    try {
        URL u = new URL("http://www.google.com/");
        connection = (HttpURLConnection) u.openConnection();
        connection.setRequestMethod("HEAD");
        int code = connection.getResponseCode();
        System.out.println("" + code);
        // You can determine on HTTP return code received. 200 is success.
    } catch (MalformedURLException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    } catch (IOException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    } finally {
        if (connection != null) {
            connection.disconnect();
        }
    }

Also check similar question How to check if a URL exists or returns 404 with Java?

Hope this helps.

How to replicate vector in c?

Vector and list aren't conceptually tied to C++. Similar structures can be implemented in C, just the syntax (and error handling) would look different. For example LodePNG implements a dynamic array with functionality very similar to that of std::vector. A sample usage looks like:

uivector v = {};
uivector_push_back(&v, 1);
uivector_push_back(&v, 42);
for(size_t i = 0; i < v.size; ++i)
    printf("%d\n", v.data[i]);
uivector_cleanup(&v);

As can be seen the usage is somewhat verbose and the code needs to be duplicated to support different types.

nothings/stb gives a simpler implementation that works with any types, but compiles only in C:

double *v = 0;
sb_push(v, 1.0);
sb_push(v, 42.0);
for(int i = 0; i < sb_count(v); ++i)
    printf("%g\n", v[i]);
sb_free(v);

A lot of C code, however, resorts to managing the memory directly with realloc:

void* newMem = realloc(oldMem, newSize);
if(!newMem) {
    // handle error
}
oldMem = newMem;

Note that realloc returns null in case of failure, yet the old memory is still valid. In such situation this common (and incorrect) usage leaks memory:

oldMem = realloc(oldMem, newSize);
if(!oldMem) {
    // handle error
}

Compared to std::vector and the C equivalents from above, the simple realloc method does not provide O(1) amortized guarantee, even though realloc may sometimes be more efficient if it happens to avoid moving the memory around.

What does $1 [QSA,L] mean in my .htaccess file?

If the following conditions are true, then rewrite the URL:
If the requested filename is not a directory,

RewriteCond %{REQUEST_FILENAME} !-d

and if the requested filename is not a regular file that exists,

RewriteCond %{REQUEST_FILENAME} !-f

and if the requested filename is not a symbolic link,

RewriteCond %{REQUEST_FILENAME} !-l

then rewrite the URL in the following way:
Take the whole request filename and provide it as the value of a "url" query parameter to index.php. Append any query string from the original URL as further query parameters (QSA), and stop processing this .htaccess file (L).

RewriteRule ^(.+)$ index.php?url=$1 [QSA,L]

Apache docs #flag_qsa

Another Example:

RewriteRule "/pages/(.+)" "/page.php?page=$1" [QSA]

With the [QSA] flag, a request for

/pages/123?one=two

will be mapped to

/page.php?page=123&one=two

OR is not supported with CASE Statement in SQL Server

Try

CASE WHEN ebv.db_no IN (22978,23218,23219) THEN 'WECS 9500' ELSE 'WECS 9520' END

ArrayList: how does the size increase?

When we try to add an object to the arraylist,

Java checks to ensure that there is enough capacity in the existing array to hold the new object. If not, a new array of a greater size is created, the old array is copied to new array using Arrays.copyOf and the new array is assigned to the existing array.

Look at the code below (taken from Java ArrayList Code at GrepCode.com).

Check this example

enter image description here

Edit:

public ArrayList() Constructs an empty list with an initial capacity of ten.

public ArrayList(int initialCapacity) we can specify initial capacity.

public ArrayList(Collection c) Constructs a list containing the elements of the specified collection, in the order they are returned by the collection's iterator.

Now when we use ArrayList() constructore we get a ArrayList with Size=10 On adding 11th element in the list new Arraylist is created inside ensureCapacity() method.

Using following formula:

  int newCapacity= (oldCapacity * 3)/2 +1;

What are allowed characters in cookies?

this one's a quickie:

You might think it should be, but really it's not at all!

What are the allowed characters in both cookie name and value?

According to the ancient Netscape cookie_spec the entire NAME=VALUE string is:

a sequence of characters excluding semi-colon, comma and white space.

So - should work, and it does seem to be OK in browsers I've got here; where are you having trouble with it?

By implication of the above:

  • = is legal to include, but potentially ambiguous. Browsers always split the name and value on the first = symbol in the string, so in practice you can put an = symbol in the VALUE but not the NAME.

What isn't mentioned, because Netscape were terrible at writing specs, but seems to be consistently supported by browsers:

  • either the NAME or the VALUE may be empty strings

  • if there is no = symbol in the string at all, browsers treat it as the cookie with the empty-string name, ie Set-Cookie: foo is the same as Set-Cookie: =foo.

  • when browsers output a cookie with an empty name, they omit the equals sign. So Set-Cookie: =bar begets Cookie: bar.

  • commas and spaces in names and values do actually seem to work, though spaces around the equals sign are trimmed

  • control characters (\x00 to \x1F plus \x7F) aren't allowed

What isn't mentioned and browsers are totally inconsistent about, is non-ASCII (Unicode) characters:

  • in Opera and Google Chrome, they are encoded to Cookie headers with UTF-8;
  • in IE, the machine's default code page is used (locale-specific and never UTF-8);
  • Firefox (and other Mozilla-based browsers) use the low byte of each UTF-16 code point on its own (so ISO-8859-1 is OK but anything else is mangled);
  • Safari simply refuses to send any cookie containing non-ASCII characters.

so in practice you cannot use non-ASCII characters in cookies at all. If you want to use Unicode, control codes or other arbitrary byte sequences, the cookie_spec demands you use an ad-hoc encoding scheme of your own choosing and suggest URL-encoding (as produced by JavaScript's encodeURIComponent) as a reasonable choice.

In terms of actual standards, there have been a few attempts to codify cookie behaviour but none thus far actually reflect the real world.

  • RFC 2109 was an attempt to codify and fix the original Netscape cookie_spec. In this standard many more special characters are disallowed, as it uses RFC 2616 tokens (a - is still allowed there), and only the value may be specified in a quoted-string with other characters. No browser ever implemented the limitations, the special handling of quoted strings and escaping, or the new features in this spec.

  • RFC 2965 was another go at it, tidying up 2109 and adding more features under a ‘version 2 cookies’ scheme. Nobody ever implemented any of that either. This spec has the same token-and-quoted-string limitations as the earlier version and it's just as much a load of nonsense.

  • RFC 6265 is an HTML5-era attempt to clear up the historical mess. It still doesn't match reality exactly but it's much better then the earlier attempts—it is at least a proper subset of what browsers support, not introducing any syntax that is supposed to work but doesn't (like the previous quoted-string).

In 6265 the cookie name is still specified as an RFC 2616 token, which means you can pick from the alphanums plus:

!#$%&'*+-.^_`|~

In the cookie value it formally bans the (filtered by browsers) control characters and (inconsistently-implemented) non-ASCII characters. It retains cookie_spec's prohibition on space, comma and semicolon, plus for compatibility with any poor idiots who actually implemented the earlier RFCs it also banned backslash and quotes, other than quotes wrapping the whole value (but in that case the quotes are still considered part of the value, not an encoding scheme). So that leaves you with the alphanums plus:

!#$%&'()*+-./:<=>?@[]^_`{|}~

In the real world we are still using the original-and-worst Netscape cookie_spec, so code that consumes cookies should be prepared to encounter pretty much anything, but for code that produces cookies it is advisable to stick with the subset in RFC 6265.

How to get current time with jQuery

I use moment for all my time manipulation/display needs (both client side, and node.js if you use it), if you just need a simple format the answers above will do, if you are looking for something a bit more complex, moment is the way to go IMO.

AngularJS - Any way for $http.post to send request parameters instead of JSON?

I have problems as well with setting custom http authentication because $resource cache the request.

To make it work you have to overwrite the existing headers by doing this

var transformRequest = function(data, headersGetter){
  var headers = headersGetter();
  headers['Authorization'] = 'WSSE profile="UsernameToken"';
  headers['X-WSSE'] = 'UsernameToken ' + nonce
  headers['Content-Type'] = 'application/json';
};

return $resource(
  url,
    {
    },
    {
      query: {
        method: 'POST',
        url: apiURL + '/profile',
        transformRequest: transformRequest,
        params: {userId: '@userId'}
      },
    }
);

I hope I was able to help someone. It took me 3 days to figure this one out.

How to add minutes to current time in swift

Two approaches:

  1. Use Calendar and date(byAdding:to:wrappingComponents:). E.g., in Swift 3 and later:

    let calendar = Calendar.current
    let date = calendar.date(byAdding: .minute, value: 5, to: startDate)
    
  2. Just use + operator (see +(_:_:)) to add a TimeInterval (i.e. a certain number of seconds). E.g. to add five minutes, you can:

    let date = startDate + 5 * 60
    

    (Note, the order is specific here: The date on the left side of the + and the seconds on the right side.)

    You can also use addingTimeInterval, if you’d prefer:

    let date = startDate.addingTimeInterval(5 * 60)
    

Bottom line, +/addingTimeInterval is easiest for simple scenarios, but if you ever want to add larger units (e.g., days, months, etc.), you would likely want to use the calendrical calculations because those adjust for daylight savings, whereas addingTimeInterval doesn’t.


For Swift 2 renditions, see the previous revision of this answer.

How to use SharedPreferences in Android to store, fetch and edit values

To store and retrieve global variables in a function way. To test, make sure you have Textview items on your page, uncomment the two lines in the code and run. Then comment the two lines again, and run.
Here the id of the TextView is username and password.

In every Class where you want to use it, add these two routines at the end. I would like this routine to be global routines, but do not know how. This works.

The variabels are available everywhere. It stores the variables in "MyFile". You may change it your way.

You call it using

 storeSession("username","frans");
 storeSession("password","!2#4%");***

the variable username will be filled with "frans" and the password with "!2#4%". Even after a restart they are available.

and you retrieve it using

 password.setText(getSession(("password")));
 usernames.setText(getSession(("username")));

below the entire code of my grid.java

    package nl.yentel.yenteldb2;
    import android.content.SharedPreferences;
    import android.os.Bundle;
    import android.support.design.widget.FloatingActionButton;
    import android.support.design.widget.Snackbar;
    import android.support.v7.app.AppCompatActivity;
    import android.support.v7.widget.Toolbar;
    import android.view.View;
    import android.widget.EditText;
    import android.widget.TextView;

    public class Grid extends AppCompatActivity {
    private TextView usernames;
    private TextView password;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
       setContentView(R.layout.activity_grid);
        Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
        setSupportActionBar(toolbar);

        FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
        fab.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                Snackbar.make(view, "Replace with your own action", Snackbar.LENGTH_LONG)
                        .setAction("Action", null).show();
            }
        });
        getSupportActionBar().setDisplayHomeAsUpEnabled(true);

      ***//  storeSession("username","[email protected]");
        //storeSession("password","mijn wachtwoord");***
        password = (TextView) findViewById(R.id.password);
        password.setText(getSession(("password")));
        usernames=(TextView) findViewById(R.id.username);
        usernames.setText(getSession(("username")));
    }

    public void storeSession(String key, String waarde) { 
        SharedPreferences pref = getApplicationContext().getSharedPreferences("MyFile", MODE_PRIVATE);
        SharedPreferences.Editor editor = pref.edit();
        editor.putString(key, waarde);
        editor.commit();
    }

    public String getSession(String key) {
//http://androidexample.com/Android_SharedPreferences_Basics/index.php?view=article_discription&aid=126&aaid=146
        SharedPreferences pref = getApplicationContext().getSharedPreferences("MyFile", MODE_PRIVATE);
        SharedPreferences.Editor editor = pref.edit();
        String output = pref.getString(key, null);
        return output;
    }

    }

below you find the textview items

<TextView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="usernames"
    android:id="@+id/username"
    android:layout_below="@+id/textView"
    android:layout_alignParentStart="true"
    android:layout_marginTop="39dp"
    android:hint="hier komt de username" />

 <TextView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="password"
    android:id="@+id/password"
    android:layout_below="@+id/user"
    android:layout_alignParentStart="true"
    android:hint="hier komt het wachtwoord" />

SQL Server 2005 Using CHARINDEX() To split a string

Here's a little function that will do "NATO encoding" for you:

CREATE FUNCTION dbo.NATOEncode (
   @String varchar(max)
)
RETURNS TABLE
WITH SCHEMABINDING
AS
RETURN (
   WITH L1 (N) AS (SELECT 1 UNION ALL SELECT 1),
   L2 (N) AS (SELECT 1 FROM L1, L1 B),
   L3 (N) AS (SELECT 1 FROM L2, L2 B),
   L4 (N) AS (SELECT 1 FROM L3, L3 B),
   L5 (N) AS (SELECT 1 FROM L4, L4 C),
   L6 (N) AS (SELECT 1 FROM L5, L5 C),
   Nums (Num) AS (SELECT Row_Number() OVER (ORDER BY (SELECT 1)) FROM L6)
   SELECT
      NATOString = Substring((
         SELECT
            Convert(varchar(max), ' ' + D.Word)
         FROM
            Nums N
            INNER JOIN (VALUES
               ('A', 'Alpha'),
               ('B', 'Beta'),
               ('C', 'Charlie'),
               ('D', 'Delta'),
               ('E', 'Echo'),
               ('F', 'Foxtrot'),
               ('G', 'Golf'),
               ('H', 'Hotel'),
               ('I', 'India'),
               ('J', 'Juliet'),
               ('K', 'Kilo'),
               ('L', 'Lima'),
               ('M', 'Mike'),
               ('N', 'November'),
               ('O', 'Oscar'),
               ('P', 'Papa'),
               ('Q', 'Quebec'),
               ('R', 'Romeo'),
               ('S', 'Sierra'),
               ('T', 'Tango'),
               ('U', 'Uniform'),
               ('V', 'Victor'),
               ('W', 'Whiskey'),
               ('X', 'X-Ray'),
               ('Y', 'Yankee'),
               ('Z', 'Zulu'),
               ('0', 'Zero'),
               ('1', 'One'),
               ('2', 'Two'),
               ('3', 'Three'),
               ('4', 'Four'),
               ('5', 'Five'),
               ('6', 'Six'),
               ('7', 'Seven'),
               ('8', 'Eight'),
               ('9', 'Niner')
            ) D (Digit, Word)
               ON Substring(@String, N.Num, 1) = D.Digit
         WHERE
            N.Num <= Len(@String)
         FOR XML PATH(''), TYPE
      ).value('.[1]', 'varchar(max)'), 2, 2147483647)
);

This function will work on even very long strings, and performs pretty well (I ran it against a 100,000-character string and it returned in 589 ms). Here's an example of how to use it:

SELECT NATOString FROM dbo.NATOEncode('LD-23DSP-1430');
-- Output: Lima Delta Two Three Delta Sierra Papa One Four Three Zero

I intentionally made it a table-valued function so it could be inlined into a query if you run it against many rows at once, just use CROSS APPLY or wrap the above example in parentheses to use it as a value in the SELECT clause (you can put a column name in the function parameter position).

How to add a progress bar to a shell script?

I was looking for something more sexy than the selected answer, so did my own script.

Preview

progress-bar.sh in action

Source

I put it on github progress-bar.sh

progress-bar() {
  local duration=${1}


    already_done() { for ((done=0; done<$elapsed; done++)); do printf "?"; done }
    remaining() { for ((remain=$elapsed; remain<$duration; remain++)); do printf " "; done }
    percentage() { printf "| %s%%" $(( (($elapsed)*100)/($duration)*100/100 )); }
    clean_line() { printf "\r"; }

  for (( elapsed=1; elapsed<=$duration; elapsed++ )); do
      already_done; remaining; percentage
      sleep 1
      clean_line
  done
  clean_line
}

Usage

 progress-bar 100

Bootstrap carousel resizing image

replace your image tag with

<img src="http://localhost:6054/wp-content/themes/BLANK-Theme/images/material/images.jpg" alt="the-buzz-img3"  style="width:640px;height:360px" />

use style attribute and make sure there is no css class for image which set image height and width

Giving multiple conditions in for loop in Java

If you prefer a code with a pretty look, you can do a break:

for(int j = 0; ; j++){
    if(j < 6
    && j < ( (int) abc[j] & 0xff)){
        break;
    }

    // Put your code here
}

Eclipse jump to closing brace

With Ctrl + Shift + L you can open the "key assist", where you can find all the shortcuts.

Counting null and non-null values in a single query

for non nulls

select count(a)
from us

for nulls

select count(*)
from us

minus 

select count(a)
from us

Hence

SELECT COUNT(A) NOT_NULLS
FROM US

UNION

SELECT COUNT(*) - COUNT(A) NULLS
FROM US

ought to do the job

Better in that the column titles come out correct.

SELECT COUNT(A) NOT_NULL, COUNT(*) - COUNT(A) NULLS
FROM US

In some testing on my system, it costs a full table scan.

NSCameraUsageDescription in iOS 10.0 runtime crash?

You do this by adding a usage key to your app’s Info.plist together with a purpose string. NSCameraUsageDescription Specifies the reason for your app to access the device’s camera

https://developer.apple.com/library/content/documentation/General/Reference/InfoPlistKeyReference/Articles/CocoaKeys.html

Replace non-numeric with empty string

You can do it easily with regex:

string subject = "(913)-444-5555";
string result = Regex.Replace(subject, "[^0-9]", ""); // result = "9134445555"

How to redirect and append both stdout and stderr to a file with Bash?

I am surprised that in almost ten years, no one has posted this approach yet:

If using older versions of bash where &>> isn't available, you also can do:

(cmd 2>&1) >> file.txt

This spawns a subshell, so it's less efficient than the traditional approach of cmd >> file.txt 2>&1, and it consequently won't work for commands that need to modify the current shell (e.g. cd, pushd), but this approach feels more natural and understandable to me:

  1. Redirect stderr to stdout.
  2. Redirect the new stdout by appending to a file.

Also, the parentheses remove any ambiguity of order, especially if you want to pipe stdout and stderr to another command instead.

Edit: To avoid starting a subshell, you instead could use curly braces instead of parentheses to create a group command:

{ cmd 2>&1; } >> file.txt

(Note that a semicolon (or newline) is required to terminate the group command.)

How to use jQuery Plugin with Angular 4?

Try using - declare let $ :any;

or import * as $ from 'jquery/dist/jquery.min.js'; provide exact path of the lib

How to check for null/empty/whitespace values with a single test?

The NULLIF function will convert any column value with only whitespace into a NULL value. Works for T-SQL and SQL Server 2008 & up.

SELECT [column_name]
FROM [table_name]
WHERE NULLIF([column_name], '') IS NULL

How to increase number of threads in tomcat thread pool?

You would have to tune it according to your environment.

Sometimes it's more useful to increase the size of the backlog (acceptCount) instead of the maximum number of threads.

Say, instead of

<Connector ... maxThreads="500" acceptCount="50"

you use

<Connector ... maxThreads="300" acceptCount="150"

you can get much better performance in some cases, cause there would be less threads disputing the resources and the backlog queue would be consumed faster.

In any case, though, you have to do some benchmarks to really know what is best.

Returning first x items from array

array_slice returns a slice of an array

$sliced_array = array_slice($array, 0, 5)

is the code you want in your case to return the first five elements

Increasing the JVM maximum heap size for memory intensive applications

In my case,

-Xms1024M -Xmx1024M is work

-Xms1024M -Xmx2048M result: Could not reserve enough space for object heap

after use JVM 64 bit, it allows using 2GB RAM, because I am using win server 2012

please see the available max heap size for JVM 32 bit on several OSs Xmx for JVM 32bit

https://www.codementor.io/@suryab/does-32-bit-or-64-bit-jvm-matter-anymore-w0sa2rk6z

How to open link in new tab on html?

You can use:

<a href="http://www.WEBSITE_NAME.com"  target="_blank"> Website</a>

However the above make your site vulnerable to phishing attacks. You can prevent it from happening in some browsers by adding rel="noopener noreferrer" to your link. With this added, the above example becomes:

<a href="http://www.WEBSITE_NAME.com" rel="noopener noreferrer" target="_blank">Website.com</a> 

check out for more information: https://www.thesitewizard.com/html-tutorial/open-links-in-new-window-or-tab.shtml

delete map[key] in go?

Use make (chan int) instead of nil. The first value has to be the same type that your map holds.

package main

import "fmt"

func main() {

    var sessions = map[string] chan int{}
    sessions["somekey"] = make(chan int)

    fmt.Printf ("%d\n", len(sessions)) // 1

    // Remove somekey's value from sessions
    delete(sessions, "somekey")

    fmt.Printf ("%d\n", len(sessions)) // 0
}

UPDATE: Corrected my answer.

how to query child objects in mongodb

If it is exactly null (as opposed to not set):

db.states.find({"cities.name": null})

(but as javierfp points out, it also matches documents that have no cities array at all, I'm assuming that they do).

If it's the case that the property is not set:

db.states.find({"cities.name": {"$exists": false}})

I've tested the above with a collection created with these two inserts:

db.states.insert({"cities": [{name: "New York"}, {name: null}]})
db.states.insert({"cities": [{name: "Austin"}, {color: "blue"}]})

The first query finds the first state, the second query finds the second. If you want to find them both with one query you can make an $or query:

db.states.find({"$or": [
  {"cities.name": null}, 
  {"cities.name": {"$exists": false}}
]})

How to install JDBC driver in Eclipse web project without facing java.lang.ClassNotFoundexception

for this error:

java.lang.ClassNotFoundException: com.mysql.jdbc.Driver

you need to:

Import java.sql.*;
Import com.mysql.jdbc.Driver;

even if its not used till app running.

What is the purpose of global.asax in asp.net

The Global.asax can be used to handle events arising from the application. This link provides a good explanation: http://aspalliance.com/1114

XAMPP installation on Win 8.1 with UAC Warning

You can solve this problem by installing xampp in different Drive .Instead of C Drive .

What is the difference between <jsp:include page = ... > and <%@ include file = ... >?

In one reusable piece of code I use the directive <%@include file="reuse.html"%> and in the second I use the standard action <jsp:include page="reuse.html" />.

Let the code in the reusable file be:

<html>
<head>
    <title>reusable</title>
    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
</head>
<body>
    <img src="candle.gif" height="100" width="50"/> <br />
    <p><b>As the candle burns,so do I</b></p>
</body>

After running both the JSP files you see the same output and think if there was any difference between the directive and the action tag. But if you look at the generated servlet of the two JSP files, you will see the difference.

Here is what you will see when you use the directive:

out.write("<html>\r\n");
out.write("    <head>\r\n");
out.write("        <title>reusable</title>\r\n");
out.write("        <meta http-equiv=\"Content-Type\" content=\"text/html; charset=UTF-8\">\r\n");
out.write("    </head>\r\n");
out.write("    <body>\r\n");
out.write("        <img src=\"candle.gif\" height=\"100\" width=\"50\"/> <br />\r\n");
out.write("        <p><b>As the candle burns,so do I</b></p>\r\n");
out.write("    </body>\r\n");
out.write("</html>\r\n");
 

And this is what you will see for the used standard action in the second JSP file :

org.apache.jasper.runtime.JspRuntimeLibrary.include(request, response, "reusable.html", out, false);

So now you know that the include directive inserts the source of reuse.html at translation time, but the action tag inserts the response of reuse.html at runtime.

If you think about it, there is an extra performance hit with every action tag (<jsp:include>). It means you can guarantee you will always have the latest content, but it increases performance cost.

How to install pip with Python 3?

This is what I did on OS X Mavericks to get this to work.

Firstly, have brew installed

Install python 3.4

brew install python3

Then I get the latest version of distribute:

wget https://pypi.python.org/packages/source/d/distribute/distribute-0.7.3.zip#md5=c6c59594a7b180af57af8a0cc0cf5b4a

unzip distribute-0.7.3.zip
cd distribute-0.7.3
sudo setup.py install
sudo easy_install-3.4 pip
sudo pip3.4 install virtualenv
sudo pip3.4 install virtualenvwrapper

mkvirtualenv py3 

python --version
Python 3.4.1

I hope this helps.

Comparing two joda DateTime instances

This code (example) :

    Chronology ch1 = GregorianChronology.getInstance();     Chronology ch2 = ISOChronology.getInstance();      DateTime dt = new DateTime("2013-12-31T22:59:21+01:00",ch1);     DateTime dt2 = new DateTime("2013-12-31T22:59:21+01:00",ch2);      System.out.println(dt);     System.out.println(dt2);      boolean b = dt.equals(dt2);      System.out.println(b); 

Will print :

2013-12-31T16:59:21.000-05:00 2013-12-31T16:59:21.000-05:00 false 

You are probably comparing two DateTimes with same date but different Chronology.

How many times does each value appear in a column?

I second Dave's idea. I'm not always fond of pivot tables, but in this case they are pretty straightforward to use.

Here are my results:

Enter image description here

It was so simple to create it that I have even recorded a macro in case you need to do this with VBA:

Sub Macro2()
'
' Macro2 Macro
'

'
    Range("Table1[[#All],[DATA]]").Select
    ActiveWorkbook.PivotCaches.Create(SourceType:=xlDatabase, SourceData:= _
        "Table1", Version:=xlPivotTableVersion14).CreatePivotTable TableDestination _
        :="Sheet3!R3C7", TableName:="PivotTable4", DefaultVersion:= _
        xlPivotTableVersion14
    Sheets("Sheet3").Select
    Cells(3, 7).Select
    With ActiveSheet.PivotTables("PivotTable4").PivotFields("DATA")
        .Orientation = xlRowField
        .Position = 1
    End With
    ActiveSheet.PivotTables("PivotTable4").AddDataField ActiveSheet.PivotTables( _
        "PivotTable4").PivotFields("DATA"), "Count of DATA", xlCount
End Sub

How to pause in C?

For Linux; getchar() is all you need.

If you are on Windows, check out the following, it is exactly what you need!

kbit() function

  • kbhit() function is used to determine if a key has been pressed or not.
  • To use kbhit() in C or C++ prorams you have to include the header file "conio.h".

For example, see how it works in the following program;

//any_key.c

#include <stdio.h> 
#include <conio.h>

int main(){

    //code here
    printf ("Press any key to continue . . .\n");
    while (1) if (kbhit()) break; 
    //code here 
    return 0;

}

When I compile and run the program, this is what I see.

Only when user presses just one key from the keyboard, kbhit() returns 1.

Validate decimal numbers in JavaScript - IsNumeric()

knockoutJs Inbuild library validation functions

By extending it the field get validated

1) number

self.number = ko.observable(numberValue).extend({ number: true});

TestCase

numberValue = '0.0'    --> true
numberValue = '0'      --> true
numberValue = '25'     --> true
numberValue = '-1'     --> true
numberValue = '-3.5'   --> true
numberValue = '11.112' --> true
numberValue = '0x89f'  --> false
numberValue = ''       --> false
numberValue = 'sfsd'   --> false
numberValue = 'dg##$'  --> false

2) digit

self.number = ko.observable(numberValue).extend({ digit: true});

TestCase

numberValue = '0'      --> true
numberValue = '25'     --> true
numberValue = '0.0'    --> false
numberValue = '-1'     --> false
numberValue = '-3.5'   --> false
numberValue = '11.112' --> false
numberValue = '0x89f'  --> false
numberValue = ''       --> false
numberValue = 'sfsd'   --> false
numberValue = 'dg##$'  --> false

3) min and max

self.number = ko.observable(numberValue).extend({ min: 5}).extend({ max: 10});

This field accept value between 5 and 10 only

TestCase

numberValue = '5'    --> true
numberValue = '6'    --> true
numberValue = '6.5'  --> true
numberValue = '9'    --> true
numberValue = '11'   --> false
numberValue = '0'    --> false
numberValue = ''    --> false

How can I convert a Unix timestamp to DateTime and vice versa?

Be careful, if you need precision higher than milliseconds!

.NET (v4.6) methods (e.g. FromUnixTimeMilliseconds) don't provide this precision.

AddSeconds and AddMilliseconds also cut off the microseconds in the double.

These versions have high precision:

Unix -> DateTime

public static DateTime UnixTimestampToDateTime(double unixTime)
{
    DateTime unixStart = new DateTime(1970, 1, 1, 0, 0, 0, 0, System.DateTimeKind.Utc);
    long unixTimeStampInTicks = (long) (unixTime * TimeSpan.TicksPerSecond);
    return new DateTime(unixStart.Ticks + unixTimeStampInTicks, System.DateTimeKind.Utc);
}

DateTime -> Unix

public static double DateTimeToUnixTimestamp(DateTime dateTime)
{
    DateTime unixStart = new DateTime(1970, 1, 1, 0, 0, 0, 0, System.DateTimeKind.Utc);
    long unixTimeStampInTicks = (dateTime.ToUniversalTime() - unixStart).Ticks;
    return (double) unixTimeStampInTicks / TimeSpan.TicksPerSecond;
}

What is the difference between MacVim and regular Vim?

The one reason I have which made switching to MacVim worth it: Yank uses the system clipboard.

I can finally copy paste between MacVim on my terminal and the rest of my applications.

Age from birthdate in python

The simplest way is using python-dateutil

import datetime

import dateutil

def birthday(date):
    # Get the current date
    now = datetime.datetime.utcnow()
    now = now.date()

    # Get the difference between the current date and the birthday
    age = dateutil.relativedelta.relativedelta(now, date)
    age = age.years

    return age

Object Dump JavaScript

In Chrome, click the 3 dots and click More tools and click developer. On the console, type console.dir(yourObject).Click this link to view an example image

good example of Javadoc

If you install a JDK and choose to install sources too, the src.zip contains the source of ALL the public Java classes. Most of these have pretty good javadoc.

How do you migrate an IIS 7 site to another server?

In my case, the files were already copied, I found the easiest way to follow the steps in this guide: https://www.ryadel.com/en/exporting-importing-app-pools-and-websites-configuration-between-multiple-iis-instances/

I exported AppPools/Websites, copied the xml files to the destination server and Imported AppPools then Websites. Worked very well. This is also another excellent option for this question.

How to monitor the memory usage of Node.js?

On Linux/Unix (note: Mac OS is a Unix) use top and press M (Shift+M) to sort processes by memory usage.

On Windows use the Task Manager.

Laravel Eloquent "WHERE NOT IN"

Query Builder:

DB::table(..)->select(..)->whereNotIn('book_price', [100,200])->get();

Eloquent:

SomeModel::select(..)->whereNotIn('book_price', [100,200])->get();

Xcode - iPhone - profile doesn't match any valid certificate-/private-key pair in the default keychain

My problem was my Target profile didn't have the proper code signing option selected:

Target Menu -> Code Signing -> Code Signing Identity

Choose "iPhone developer" then select the provisional profile you created.

node.js: cannot find module 'request'

I have met the same problem as I install it globally, then I try to install it locally, and it work.

Create a CSS rule / class with jQuery at runtime

Maybe you can put the style information in a separate class in your css file, e.g.:

.specificstyle {
    position: fixed;
    z-index: 102;
    display:none;
    top:50%;
    left:50%;
}

and then use jQuery at the point of your choosing to add this classname to the element?

How can I select checkboxes using the Selenium Java WebDriver?

Step 1:

The object locator supposed to be used here is XPath. So derive the XPath for those two checkboxes.

String housingmoves="//label[contains(text(),'housingmoves')]/preceding-sibling::input";
String season_country_homes="//label[contains(text(),'Seaside & Country Homes')]/preceding-sibling::input";

Step 2:

Perform a click on the checkboxes

driver.findElement(By.xpath(housingmoves)).click();
driver.findElement(By.xpath(season_country_homes)).click();

what is the use of Eval() in asp.net

While binding a databound control, you can evaluate a field of the row in your data source with eval() function.

For example you can add a column to your gridview like that :

<asp:BoundField DataField="YourFieldName" />

And alternatively, this is the way with eval :

<asp:TemplateField>
<ItemTemplate>
        <asp:Label ID="lbl" runat="server" Text='<%# Eval("YourFieldName") %>'>
        </asp:Label>
</ItemTemplate>
</asp:TemplateField>

It seems a little bit complex, but it's flexible, because you can set any property of the control with the eval() function :

<asp:TemplateField>
    <ItemTemplate>
        <asp:HyperLink ID="HyperLink1" runat="server" 
          NavigateUrl='<%# "ShowDetails.aspx?id="+Eval("Id") %>' 
          Text='<%# Eval("Text", "{0}") %>'></asp:HyperLink>
    </ItemTemplate>
</asp:TemplateField>

how to insert datetime into the SQL Database table?

You will need to have a datetime column in a table. Then you can do an insert like the following to insert the current date:

INSERT INTO MyTable (MyDate) Values (GetDate())

If it is not today's date then you should be able to use a string and specify the date format:

INSERT INTO MyTable (MyDate) Values (Convert(DateTime,'19820626',112)) --6/26/1982

You do not always need to convert the string either, often you can just do something like:

INSERT INTO MyTable (MyDate) Values ('06/26/1982') 

And SQL Server will figure it out for you.

Modifying a subset of rows in a pandas dataframe

Starting from pandas 0.20 ix is deprecated. The right way is to use df.loc

here is a working example

>>> import pandas as pd 
>>> import numpy as np 
>>> df = pd.DataFrame({"A":[0,1,0], "B":[2,0,5]}, columns=list('AB'))
>>> df.loc[df.A == 0, 'B'] = np.nan
>>> df
   A   B
0  0 NaN
1  1   0
2  0 NaN
>>> 

Explanation:

As explained in the doc here, .loc is primarily label based, but may also be used with a boolean array.

So, what we are doing above is applying df.loc[row_index, column_index] by:

  • Exploiting the fact that loc can take a boolean array as a mask that tells pandas which subset of rows we want to change in row_index
  • Exploiting the fact loc is also label based to select the column using the label 'B' in the column_index

We can use logical, condition or any operation that returns a series of booleans to construct the array of booleans. In the above example, we want any rows that contain a 0, for that we can use df.A == 0, as you can see in the example below, this returns a series of booleans.

>>> df = pd.DataFrame({"A":[0,1,0], "B":[2,0,5]}, columns=list('AB'))
>>> df 
   A  B
0  0  2
1  1  0
2  0  5
>>> df.A == 0 
0     True
1    False
2     True
Name: A, dtype: bool
>>> 

Then, we use the above array of booleans to select and modify the necessary rows:

>>> df.loc[df.A == 0, 'B'] = np.nan
>>> df
   A   B
0  0 NaN
1  1   0
2  0 NaN

For more information check the advanced indexing documentation here.

How to unzip gz file using Python

Maybe you want pass it to pandas also.

with gzip.open('features_train.csv.gz') as f:

    features_train = pd.read_csv(f)

features_train.head()

Query to list all stored procedures

select * from DatabaseName.INFORMATION_SCHEMA.ROUTINES where routine_type = 'PROCEDURE'

select * from DatabaseName.INFORMATION_SCHEMA.ROUTINES where routine_type ='procedure' and left(ROUTINE_NAME,3) not in('sp_', 'xp_', 'ms_')


   SELECT name, type   FROM dbo.sysobjects
 WHERE (type = 'P')

Multiple rows to one comma-separated value in Sql Server

Test Data

DECLARE @Table1 TABLE(ID INT, Value INT)
INSERT INTO @Table1 VALUES (1,100),(1,200),(1,300),(1,400)

Query

SELECT  ID
       ,STUFF((SELECT ', ' + CAST(Value AS VARCHAR(10)) [text()]
         FROM @Table1 
         WHERE ID = t.ID
         FOR XML PATH(''), TYPE)
        .value('.','NVARCHAR(MAX)'),1,2,' ') List_Output
FROM @Table1 t
GROUP BY ID

Result Set

+--------------------------+
¦ ID ¦     List_Output     ¦
¦----+---------------------¦
¦  1 ¦  100, 200, 300, 400 ¦
+--------------------------+

SQL Server 2017 and Later Versions

If you are working on SQL Server 2017 or later versions, you can use built-in SQL Server Function STRING_AGG to create the comma delimited list:

DECLARE @Table1 TABLE(ID INT, Value INT);
INSERT INTO @Table1 VALUES (1,100),(1,200),(1,300),(1,400);


SELECT ID , STRING_AGG([Value], ', ') AS List_Output
FROM @Table1
GROUP BY ID;

Result Set

+--------------------------+
¦ ID ¦     List_Output     ¦
¦----+---------------------¦
¦  1 ¦  100, 200, 300, 400 ¦
+--------------------------+

Python and pip, list all versions of a package that's available?

https://pypi.python.org/pypi/Django/ - works for packages whose maintainers choose to show all packages https://pypi.python.org/simple/pip/ - should do the trick anyhow (lists all links)

urlencode vs rawurlencode?

I believe spaces must be encoded as:

  • %20 when used inside URL path component
  • + when used inside URL query string component or form data (see 17.13.4 Form content types)

The following example shows the correct use of rawurlencode and urlencode:

echo "http://example.com"
    . "/category/" . rawurlencode("latest songs")
    . "/search?q=" . urlencode("lady gaga");

Output:

http://example.com/category/latest%20songs/search?q=lady+gaga

What happens if you encode path and query string components the other way round? For the following example:

http://example.com/category/latest+songs/search?q=lady%20gaga
  • The webserver will look for the directory latest+songs instead of latest songs
  • The query string parameter q will contain lady gaga

Removing Data From ElasticSearch

To list down the indices curl -L localhost:9200/_cat/indices

9200 default port[change the port if using some other port]

You will likely find all indices starting with logstash-yyyy-mm-dd format(logstash-*)

You can see all the indices and use

To delete the indices and data trigger following command.

curl -XDELETE localhost:9200/index_name (Which will remove the data and indices both).

How to add custom Http Header for C# Web Service Client consuming Axis 1.4 Web service

I find this code and is resolve my problem.

http://arcware.net/setting-http-header-authorization-for-web-services/

protected override WebRequest GetWebRequest(Uri uri)
{
    // Assuming authValue is set from somewhere, such as the config file
    HttpWebRequest request = (HttpWebRequest)base.GetWebRequest(uri);
    request.Headers.Add("Authorization", string.Format("Basic {0}", authValue));
    return request;
}

How to compile python script to binary executable

Since other SO answers link to this question it's worth noting that there is another option now in PyOxidizer.

It's a rust utility which works in some of the same ways as pyinstaller, however has some additional features detailed here, to summarize the key ones:

  • Single binary of all packages by default with the ability to do a zero-copy load of modules into memory, vs pyinstaller extracting them to a temporary directory when using onefile mode
  • Ability to produce a static linked binary

(One other advantage of pyoxidizer is that it does not seem to suffer from the GLIBC_X.XX not found problem that can crop up with pyinstaller if you've created your binary on a system that has a glibc version newer than the target system).

Overall pyinstaller is much simpler to use than PyOxidizer, which often requires some complexity in the configuration file, and it's less Pythony since it's written in Rust and uses a configuration file format not very familiar in the Python world, but PyOxidizer does some more advanced stuff, especially if you are looking to produce single binaries (which is not pyinstaller's default).

How to have Java method return generic list of any type?

Something like this

publi? <T> List<T> magicalListGetter(Class<T> clazz) {
    List list = doMagicalVooDooHere();
    return list;
}

What is a plain English explanation of "Big O" notation?

Big O

f(x) = O(g(x)) when x goes to a (for example, a = +8) means that there is a function k such that:

  1. f(x) = k(x)g(x)

  2. k is bounded in some neighborhood of a (if a = +8, this means that there are numbers N and M such that for every x > N, |k(x)| < M).

In other words, in plain English: f(x) = O(g(x)), x ? a, means that in a neighborhood of a, f decomposes into the product of g and some bounded function.

Small o

By the way, here is for comparison the definition of small o.

f(x) = o(g(x)) when x goes to a means that there is a function k such that:

  1. f(x) = k(x)g(x)

  2. k(x) goes to 0 when x goes to a.

Examples

  • sin x = O(x) when x ? 0.

  • sin x = O(1) when x ? +8,

  • x2 + x = O(x) when x ? 0,

  • x2 + x = O(x2) when x ? +8,

  • ln(x) = o(x) = O(x) when x ? +8.

Attention! The notation with the equal sign "=" uses a "fake equality": it is true that o(g(x)) = O(g(x)), but false that O(g(x)) = o(g(x)). Similarly, it is ok to write "ln(x) = o(x) when x ? +8", but the formula "o(x) = ln(x)" would make no sense.

More examples

  • O(1) = O(n) = O(n2) when n ? +8 (but not the other way around, the equality is "fake"),

  • O(n) + O(n2) = O(n2) when n ? +8

  • O(O(n2)) = O(n2) when n ? +8

  • O(n2)O(n3) = O(n5) when n ? +8


Here is the Wikipedia article: https://en.wikipedia.org/wiki/Big_O_notation

javascript window.location in new tab

window.open('https://support.wwf.org.uk', '_blank');

The second parameter is what makes it open in a new window. Don't forget to read Jakob Nielsen's informative article :)

xml.LoadData - Data at the root level is invalid. Line 1, position 1

if we are using XDocument.Parse(@""). Use @ it resolves the issue.

Git add and commit in one command

  1. Create an alias in bash: alias gac="git add -A && git commit -m"

    (I chose to call the shortcut 'gac' but you don't have to)

  2. Use it: gac 'your commit message here'

WAMP won't turn green. And the VCRUNTIME140.dll error

You need to install some Visual C++ packages BEFORE installing WAMP (if you have installed then you must uninstall and reinstall).

You need: VC9, VC10, VC11, VC13 and VC14

In readme.txt of wampserver 3 (on SourceForge) you can find the links.

Be careful! If you use a 64-bit OS you need to install both versions of each package.

How to debug SSL handshake using cURL?

openssl s_client -connect 127.0.0.1:6379 -state
CONNECTED(00000003)
SSL_connect:before SSL initialization
SSL_connect:SSLv3/TLS write client hello

Sending a file over TCP sockets in Python

Remove below code

s.send("Hello server!")

because your sending s.send("Hello server!") to server, so your output file is somewhat more in size.

Replace Fragment inside a ViewPager

Works Great with AndroidTeam's solution, however I found that I needed the ability to go back much like FrgmentTransaction.addToBackStack(null) But merely adding this will only cause the Fragment to be replaced without notifying the ViewPager. Combining the provided solution with this minor enhancement will allow you to return to the previous state by merely overriding the activity's onBackPressed() method. The biggest drawback is that it will only go back one at a time which may result in multiple back clicks

private ArrayList<Fragment> bFragments = new ArrayList<Fragment>();
private ArrayList<Integer> bPosition = new ArrayList<Integer>();

public void replaceFragmentsWithBackOut(ViewPager container, Fragment oldFragment, Fragment newFragment) {
    startUpdate(container);

    // remove old fragment

    if (mCurTransaction == null) {
         mCurTransaction = mFragmentManager.beginTransaction();
     }
    int position = getFragmentPosition(oldFragment);
     while (mSavedState.size() <= position) {
         mSavedState.add(null);
     }

     //Add Fragment to Back List
     bFragments.add(oldFragment);

     //Add Pager Position to Back List
     bPosition.add(position);

     mSavedState.set(position, null);
     mFragments.set(position, null);

     mCurTransaction.remove(oldFragment);

     // add new fragment

     while (mFragments.size() <= position) {
         mFragments.add(null);
     }
     mFragments.set(position, newFragment);
     mCurTransaction.add(container.getId(), newFragment);

    finishUpdate(container);

    // ensure getItem returns newFragemtn after calling handleGetItemInbalidated()
    handleGetItemInvalidated(container, oldFragment, newFragment);

    container.notifyItemChanged(oldFragment, newFragment);
 }


public boolean popBackImmediate(ViewPager container){
    int bFragSize = bFragments.size();
    int bPosSize = bPosition.size();

    if(bFragSize>0 && bPosSize>0){
        if(bFragSize==bPosSize){
            int last = bFragSize-1;
            int position = bPosition.get(last);

            //Returns Fragment Currently at this position
            Fragment replacedFragment = mFragments.get(position);               
            Fragment originalFragment = bFragments.get(last);

            this.replaceFragments(container, replacedFragment, originalFragment);

            bPosition.remove(last);
            bFragments.remove(last);

            return true;
        }
    }

    return false;       
}

Hope this helps someone.

Also as far as getFragmentPosition() goes it's pretty much getItem() in reverse. You know which fragments go where, just make sure you return the correct position it will be in. Here's an example:

    @Override
    protected int getFragmentPosition(Fragment fragment) {
            if(fragment.equals(originalFragment1)){
                return 0;
            }
            if(fragment.equals(replacementFragment1)){
                return 0;
            }
            if(fragment.equals(Fragment2)){
                return 1;
            }
        return -1;
    }

Pinging an IP address using PHP and echoing the result

i just wrote a very fast solution by combining all knowledge gain above

    function pinger($address){
        if(strtolower(PHP_OS)=='winnt'){
            $command = "ping -n 1 $address";
            exec($command, $output, $status);
        }else{
            $command = "ping -c 1 $address";
            exec($command, $output, $status);
        }
        if($status === 0){
            return true;
        }else{
            return false;
        }
    }

How to create a file in memory for user to download, but not through server?

Based on @Rick answer which was really helpful.

You have to scape the string data if you want to share it this way:

$('a.download').attr('href', 'data:application/csv;charset=utf-8,'+ encodeURI(data));

` Sorry I can not comment on @Rick's answer due to my current low reputation in StackOverflow.

An edit suggestion was shared and rejected.

jQuery: using a variable as a selector

You're thinking too complicated. It's actually just $('#'+openaddress).

Google API for location, based on user IP address

Here's a script that will use the Google API to acquire the users postal code and populate an input field.

function postalCodeLookup(input) {
    var head= document.getElementsByTagName('head')[0],
        script= document.createElement('script');
    script.src= '//maps.googleapis.com/maps/api/js?sensor=false';
    head.appendChild(script);
    script.onload = function() {
        if (navigator.geolocation) {
            var a = input,
                fallback = setTimeout(function () {
                    fail('10 seconds expired');
                }, 10000);

            navigator.geolocation.getCurrentPosition(function (pos) {
                clearTimeout(fallback);
                var point = new google.maps.LatLng(pos.coords.latitude, pos.coords.longitude);
                new google.maps.Geocoder().geocode({'latLng': point}, function (res, status) {
                    if (status == google.maps.GeocoderStatus.OK && typeof res[0] !== 'undefined') {
                        var zip = res[0].formatted_address.match(/,\s\w{2}\s(\d{5})/);
                        if (zip) {
                            a.value = zip[1];
                        } else fail('Unable to look-up postal code');
                    } else {
                        fail('Unable to look-up geolocation');
                    }
                });
            }, function (err) {
                fail(err.message);
            });
        } else {
            alert('Unable to find your location.');
        }
        function fail(err) {
            console.log('err', err);
            a.value('Try Again.');
        }
    };
}

You can adjust accordingly to acquire different information. For more info, check out the Google Maps API documentation.

Java reflection: how to get field value from an object, not knowing its class

public abstract class Refl {
    /** Use: Refl.<TargetClass>get(myObject,"x.y[0].z"); */
    public static<T> T get(Object obj, String fieldPath) {
        return (T) getValue(obj, fieldPath);
    }
    public static Object getValue(Object obj, String fieldPath) {
        String[] fieldNames = fieldPath.split("[\\.\\[\\]]");
        String success = "";
        Object res = obj;
        for (String fieldName : fieldNames) {
            if (fieldName.isEmpty()) continue;
            int index = toIndex(fieldName);
            if (index >= 0) {
                try {
                    res = ((Object[])res)[index];
                } catch (ClassCastException cce) {
                    throw new RuntimeException("cannot cast "+res.getClass()+" object "+res+" to array, path:"+success, cce);
                } catch (IndexOutOfBoundsException iobe) {
                    throw new RuntimeException("bad index "+index+", array size "+((Object[])res).length +" object "+res +", path:"+success, iobe);
                }
            } else {
                Field field = getField(res.getClass(), fieldName);
                field.setAccessible(true);
                try {
                    res = field.get(res);
                } catch (Exception ee) {
                    throw new RuntimeException("cannot get value of ["+fieldName+"] from "+res.getClass()+" object "+res +", path:"+success, ee);
                }
            }
            success += fieldName + ".";
        }
        return res;
    }

    public static Field getField(Class<?> clazz, String fieldName) {
        Class<?> tmpClass = clazz;
        do {
            try {
                Field f = tmpClass.getDeclaredField(fieldName);
                return f;
            } catch (NoSuchFieldException e) {
                tmpClass = tmpClass.getSuperclass();
            }
        } while (tmpClass != null);

        throw new RuntimeException("Field '" + fieldName + "' not found in class " + clazz);
    }

    private static int toIndex(String s) {
        int res = -1;
        if (s != null && s.length() > 0 && Character.isDigit(s.charAt(0))) {
            try {
                res = Integer.parseInt(s);
                if (res < 0) {
                    res = -1;
                }
            } catch (Throwable t) {
                res = -1;
            }
        }
        return res;
    }
}

It supports fetching fields and array items, e.g.:

System.out.println(""+Refl.getValue(b,"x.q[0].z.y"));

there is no difference between dots and braces, they are just delimiters, and empty field names are ignored:

System.out.println(""+Refl.getValue(b,"x.q[0].z.y[value]"));
System.out.println(""+Refl.getValue(b,"x.q.1.y.z.value"));
System.out.println(""+Refl.getValue(b,"x[q.1]y]z[value"));

What are the best practices for SQLite on Android?

You can try to apply new architecture approach anounced at Google I/O 2017.

It also includes new ORM library called Room

It contains three main components: @Entity, @Dao and @Database

User.java

@Entity
public class User {
  @PrimaryKey
  private int uid;

  @ColumnInfo(name = "first_name")
  private String firstName;

  @ColumnInfo(name = "last_name")
  private String lastName;

  // Getters and setters are ignored for brevity,
  // but they're required for Room to work.
}

UserDao.java

@Dao
public interface UserDao {
  @Query("SELECT * FROM user")
  List<User> getAll();

  @Query("SELECT * FROM user WHERE uid IN (:userIds)")
  List<User> loadAllByIds(int[] userIds);

  @Query("SELECT * FROM user WHERE first_name LIKE :first AND "
       + "last_name LIKE :last LIMIT 1")
  User findByName(String first, String last);

  @Insert
  void insertAll(User... users);

  @Delete
  void delete(User user);
}

AppDatabase.java

@Database(entities = {User.class}, version = 1)
public abstract class AppDatabase extends RoomDatabase {
  public abstract UserDao userDao();
}

navigator.geolocation.getCurrentPosition sometimes works sometimes doesn't

Same here people, this works perfect btw in Chrome (stable, dev and canary) just not in FF and Safari. It also works perfect on my iPhone and iPad (Safari!). This might be due to the relative newness of this feature (i.e. it is a bug). I spend almost a week on this now and I just cannot get it to work on those browsers

Here's what I found:

The first time you call getCurrentPosition it works perfect. Any subsequent call never returns, i.e. it does not fire the successCallback or the errorCallback functions. I added a few position options to my call to prove my point:

 navigator.geolocation.getCurrentPosition(successCallback, errorCallback,  {timeout: 10000});

and it times out every time (after the first successful call). I thought I could fix it with maximumAge, but that doesn't seem to be working as it is suppose to work either:

navigator.geolocation.getCurrentPosition(successCallback, errorCallback,  {maximumAge:60000, timeout: 2000});

this should prevent actually calling the getCurrentPosition function if you call it within 60 seconds, but it ignores this (however, this could be due because I actually refresh my page to trigger the second call, not sure if this is persistent accross calls)

btw, even google's examples fail on these browsers which leads me to believe that this are indeed browser bugs, try it, load it twice in Safari and it won't work the second time.

If anybody finds a solution for this, PLEASE let me know :-)

Cheers.

How to install pip for Python 3.6 on Ubuntu 16.10?

In at least in ubuntu 16.10, the default python3 is python3.5. As such, all of the python3-X packages will be installed for python3.5 and not for python3.6.

You can verify this by checking the shebang of pip3:

$ head -n1 $(which pip3)
#!/usr/bin/python3

Fortunately, the pip installed by the python3-pip package is installed into the "shared" /usr/lib/python3/dist-packages such that python3.6 can also take advantage of it.

You can install packages for python3.6 by doing:

python3.6 -m pip install ...

For example:

$ python3.6 -m pip install requests
$ python3.6 -c 'import requests; print(requests.__file__)'
/usr/local/lib/python3.6/dist-packages/requests/__init__.py

AngularJS- Login and Authentication in each route and controller

Here is another possible solution, using the resolve attribute of the $stateProvider or the $routeProvider. Example with $stateProvider:

.config(["$stateProvider", function ($stateProvider) {

  $stateProvider

  .state("forbidden", {
    /* ... */
  })

  .state("signIn", {
    /* ... */
    resolve: {
      access: ["Access", function (Access) { return Access.isAnonymous(); }],
    }
  })

  .state("home", {
    /* ... */
    resolve: {
      access: ["Access", function (Access) { return Access.isAuthenticated(); }],
    }
  })

  .state("admin", {
    /* ... */
    resolve: {
      access: ["Access", function (Access) { return Access.hasRole("ROLE_ADMIN"); }],
    }
  });

}])

Access resolves or rejects a promise depending on the current user rights:

.factory("Access", ["$q", "UserProfile", function ($q, UserProfile) {

  var Access = {

    OK: 200,

    // "we don't know who you are, so we can't say if you're authorized to access
    // this resource or not yet, please sign in first"
    UNAUTHORIZED: 401,

    // "we know who you are, and your profile does not allow you to access this resource"
    FORBIDDEN: 403,

    hasRole: function (role) {
      return UserProfile.then(function (userProfile) {
        if (userProfile.$hasRole(role)) {
          return Access.OK;
        } else if (userProfile.$isAnonymous()) {
          return $q.reject(Access.UNAUTHORIZED);
        } else {
          return $q.reject(Access.FORBIDDEN);
        }
      });
    },

    hasAnyRole: function (roles) {
      return UserProfile.then(function (userProfile) {
        if (userProfile.$hasAnyRole(roles)) {
          return Access.OK;
        } else if (userProfile.$isAnonymous()) {
          return $q.reject(Access.UNAUTHORIZED);
        } else {
          return $q.reject(Access.FORBIDDEN);
        }
      });
    },

    isAnonymous: function () {
      return UserProfile.then(function (userProfile) {
        if (userProfile.$isAnonymous()) {
          return Access.OK;
        } else {
          return $q.reject(Access.FORBIDDEN);
        }
      });
    },

    isAuthenticated: function () {
      return UserProfile.then(function (userProfile) {
        if (userProfile.$isAuthenticated()) {
          return Access.OK;
        } else {
          return $q.reject(Access.UNAUTHORIZED);
        }
      });
    }

  };

  return Access;

}])

UserProfile copies the current user properties, and implement the $hasRole, $hasAnyRole, $isAnonymous and $isAuthenticated methods logic (plus a $refresh method, explained later):

.factory("UserProfile", ["Auth", function (Auth) {

  var userProfile = {};

  var clearUserProfile = function () {
    for (var prop in userProfile) {
      if (userProfile.hasOwnProperty(prop)) {
        delete userProfile[prop];
      }
    }
  };

  var fetchUserProfile = function () {
    return Auth.getProfile().then(function (response) {
      clearUserProfile();
      return angular.extend(userProfile, response.data, {

        $refresh: fetchUserProfile,

        $hasRole: function (role) {
          return userProfile.roles.indexOf(role) >= 0;
        },

        $hasAnyRole: function (roles) {
          return !!userProfile.roles.filter(function (role) {
            return roles.indexOf(role) >= 0;
          }).length;
        },

        $isAnonymous: function () {
          return userProfile.anonymous;
        },

        $isAuthenticated: function () {
          return !userProfile.anonymous;
        }

      });
    });
  };

  return fetchUserProfile();

}])

Auth is in charge of requesting the server, to know the user profile (linked to an access token attached to the request for example):

.service("Auth", ["$http", function ($http) {

  this.getProfile = function () {
    return $http.get("api/auth");
  };

}])

The server is expected to return such a JSON object when requesting GET api/auth:

{
  "name": "John Doe", // plus any other user information
  "roles": ["ROLE_ADMIN", "ROLE_USER"], // or any other role (or no role at all, i.e. an empty array)
  "anonymous": false // or true
}

Finally, when Access rejects a promise, if using ui.router, the $stateChangeError event will be fired:

.run(["$rootScope", "Access", "$state", "$log", function ($rootScope, Access, $state, $log) {

  $rootScope.$on("$stateChangeError", function (event, toState, toParams, fromState, fromParams, error) {
    switch (error) {

    case Access.UNAUTHORIZED:
      $state.go("signIn");
      break;

    case Access.FORBIDDEN:
      $state.go("forbidden");
      break;

    default:
      $log.warn("$stateChangeError event catched");
      break;

    }
  });

}])

If using ngRoute, the $routeChangeError event will be fired:

.run(["$rootScope", "Access", "$location", "$log", function ($rootScope, Access, $location, $log) {

  $rootScope.$on("$routeChangeError", function (event, current, previous, rejection) {
    switch (rejection) {

    case Access.UNAUTHORIZED:
      $location.path("/signin");
      break;

    case Access.FORBIDDEN:
      $location.path("/forbidden");
      break;

    default:
      $log.warn("$stateChangeError event catched");
      break;

    }
  });

}])

The user profile can also be accessed in the controllers:

.state("home", {
  /* ... */
  controller: "HomeController",
  resolve: {
    userProfile: "UserProfile"
  }
})

UserProfile then contains the properties returned by the server when requesting GET api/auth:

.controller("HomeController", ["$scope", "userProfile", function ($scope, userProfile) {

  $scope.title = "Hello " + userProfile.name; // "Hello John Doe" in the example

}])

UserProfile needs to be refreshed when a user signs in or out, so that Access can handle the routes with the new user profile. You can either reload the whole page, or call UserProfile.$refresh(). Example when signing in:

.service("Auth", ["$http", function ($http) {

  /* ... */

  this.signIn = function (credentials) {
    return $http.post("api/auth", credentials).then(function (response) {
      // authentication succeeded, store the response access token somewhere (if any)
    });
  };

}])
.state("signIn", {
  /* ... */
  controller: "SignInController",
  resolve: {
    /* ... */
    userProfile: "UserProfile"
  }
})
.controller("SignInController", ["$scope", "$state", "Auth", "userProfile", function ($scope, $state, Auth, userProfile) {

  $scope.signIn = function () {
    Auth.signIn($scope.credentials).then(function () {
      // user successfully authenticated, refresh UserProfile
      return userProfile.$refresh();
    }).then(function () {
      // UserProfile is refreshed, redirect user somewhere
      $state.go("home");
    });
  };

}])

Convert Uri to String and String to Uri

This will get the file path from the MediaProvider, DownloadsProvider, and ExternalStorageProvider, while falling back to the unofficial ContentProvider method you mention.

   /**
 * Get a file path from a Uri. This will get the the path for Storage Access
 * Framework Documents, as well as the _data field for the MediaStore and
 * other file-based ContentProviders.
 *
 * @param context The context.
 * @param uri The Uri to query.
 * @author paulburke
 */
public static String getPath(final Context context, final Uri uri) {

    final boolean isKitKat = Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT;

    // DocumentProvider
    if (isKitKat && DocumentsContract.isDocumentUri(context, uri)) {
        // ExternalStorageProvider
        if (isExternalStorageDocument(uri)) {
            final String docId = DocumentsContract.getDocumentId(uri);
            final String[] split = docId.split(":");
            final String type = split[0];

            if ("primary".equalsIgnoreCase(type)) {
                return Environment.getExternalStorageDirectory() + "/" + split[1];
            }

            // TODO handle non-primary volumes
        }
        // DownloadsProvider
        else if (isDownloadsDocument(uri)) {

            final String id = DocumentsContract.getDocumentId(uri);
            final Uri contentUri = ContentUris.withAppendedId(
                    Uri.parse("content://downloads/public_downloads"), Long.valueOf(id));

            return getDataColumn(context, contentUri, null, null);
        }
        // MediaProvider
        else if (isMediaDocument(uri)) {
            final String docId = DocumentsContract.getDocumentId(uri);
            final String[] split = docId.split(":");
            final String type = split[0];

            Uri contentUri = null;
            if ("image".equals(type)) {
                contentUri = MediaStore.Images.Media.EXTERNAL_CONTENT_URI;
            } else if ("video".equals(type)) {
                contentUri = MediaStore.Video.Media.EXTERNAL_CONTENT_URI;
            } else if ("audio".equals(type)) {
                contentUri = MediaStore.Audio.Media.EXTERNAL_CONTENT_URI;
            }

            final String selection = "_id=?";
            final String[] selectionArgs = new String[] {
                    split[1]
            };

            return getDataColumn(context, contentUri, selection, selectionArgs);
        }
    }
    // MediaStore (and general)
    else if ("content".equalsIgnoreCase(uri.getScheme())) {
        return getDataColumn(context, uri, null, null);
    }
    // File
    else if ("file".equalsIgnoreCase(uri.getScheme())) {
        return uri.getPath();
    }

    return null;
}

/**
 * Get the value of the data column for this Uri. This is useful for
 * MediaStore Uris, and other file-based ContentProviders.
 *
 * @param context The context.
 * @param uri The Uri to query.
 * @param selection (Optional) Filter used in the query.
 * @param selectionArgs (Optional) Selection arguments used in the query.
 * @return The value of the _data column, which is typically a file path.
 */
public static String getDataColumn(Context context, Uri uri, String selection,
        String[] selectionArgs) {

    Cursor cursor = null;
    final String column = "_data";
    final String[] projection = {
            column
    };

    try {
        cursor = context.getContentResolver().query(uri, projection, selection, selectionArgs,
                null);
        if (cursor != null && cursor.moveToFirst()) {
            final int column_index = cursor.getColumnIndexOrThrow(column);
            return cursor.getString(column_index);
        }
    } finally {
        if (cursor != null)
            cursor.close();
    }
    return null;
}


/**
 * @param uri The Uri to check.
 * @return Whether the Uri authority is ExternalStorageProvider.
 */
public static boolean isExternalStorageDocument(Uri uri) {
    return "com.android.externalstorage.documents".equals(uri.getAuthority());
}

/**
 * @param uri The Uri to check.
 * @return Whether the Uri authority is DownloadsProvider.
 */
public static boolean isDownloadsDocument(Uri uri) {
    return "com.android.providers.downloads.documents".equals(uri.getAuthority());
}

/**
 * @param uri The Uri to check.
 * @return Whether the Uri authority is MediaProvider.
 */
public static boolean isMediaDocument(Uri uri) {
    return "com.android.providers.media.documents".equals(uri.getAuthority());
}

How to build minified and uncompressed bundle with webpack?

You can run webpack twice with different arguments:

$ webpack --minimize

then check command line arguments in webpack.config.js:

var path = require('path'),
  webpack = require('webpack'),
  minimize = process.argv.indexOf('--minimize') !== -1,
  plugins = [];

if (minimize) {
  plugins.push(new webpack.optimize.UglifyJsPlugin());
}

...

example webpack.config.js

How do I install a plugin for vim?

I think you should have a look at the Pathogen plugin. After you have this installed, you can keep all of your plugins in separate folders in ~/.vim/bundle/, and Pathogen will take care of loading them.

Or, alternatively, perhaps you would prefer Vundle, which provides similar functionality (with the added bonus of automatic updates from plugins in github).

'this' is undefined in JavaScript class methods

Use arrow function:

Request.prototype.start = () => {
    if( this.stay_open == true ) {
        this.open({msg: 'listen'});
    } else {

    }
};

Check if string contains only whitespace

Here is an answer that should work in all cases:

def is_empty(s):
    "Check whether a string is empty"
    return not s or not s.strip()

If the variable is None, it will stop at not sand not evaluate further (since not None == True). Apparently, the strip()method takes care of the usual cases of tab, newline, etc.

did you specify the right host or port? error on Kubernetes

If you created a cluster on AWS using kops, then kops creates ~/.kube/config for you, which is nice. But if someone else needs to connect to that cluster, then they also need to install kops so that it can create the kubeconfig for you:

export AWS_ACCESS_KEY_ID=$(aws configure get aws_access_key_id)
export AWS_SECRET_ACCESS_KEY=$(aws configure get aws_secret_access_key)
export CLUSTER_ALIAS=kubernetes-cluster

kubectl config set-context ${CLUSTER_ALIAS} \
    --cluster=${CLUSTER_FULL_NAME} \
    --user=${CLUSTER_FULL_NAME}

kubectl config use-context ${CLUSTER_ALIAS}

kops export cluster --name ${CLUSTER_FULL_NAME} \
  --region=${CLUSTER_REGION} \
  --state=${KOPS_STATE_STORE}

Append integer to beginning of list in Python

Another way of doing the same,

list[0:0] = [a]

How do I know which version of Javascript I'm using?

Wikipedia (or rather, the community on Wikipedia) keeps a pretty good up-to-date list here.

  • Most browsers are on 1.5 (though they have features of later versions)
  • Mozilla progresses with every dot release (they maintain the standard so that's not surprising)
  • Firefox 4 is on JavaScript 1.8.5
  • The other big off-the-beaten-path one is IE9 - it implements ECMAScript 5, but doesn't implement all the features of JavaScript 1.8.5 (not sure what they're calling this version of JScript, engine codenamed Chakra, yet).

Is there an R function for finding the index of an element in a vector?

the function Position in funprog {base} also does the job. It allows you to pass an arbitrary function, and returns the first or last match.

Position(f, x, right = FALSE, nomatch = NA_integer)

Convert Json String to C# Object List

using dynamic variable in C# is the simplest.

Newtonsoft.Json.Linq has class JValue that can be used. Below is a sample code which displays Question id and text from the JSON string you have.

        string jsonString = "[{\"Question\":{\"QuestionId\":49,\"QuestionText\":\"Whats your name?\",\"TypeId\":1,\"TypeName\":\"MCQ\",\"Model\":{\"options\":[{\"text\":\"Rahul\",\"selectedMarks\":\"0\"},{\"text\":\"Pratik\",\"selectedMarks\":\"9\"},{\"text\":\"Rohit\",\"selectedMarks\":\"0\"}],\"maxOptions\":10,\"minOptions\":0,\"isAnswerRequired\":true,\"selectedOption\":\"1\",\"answerText\":\"\",\"isRangeType\":false,\"from\":\"\",\"to\":\"\",\"mins\":\"02\",\"secs\":\"04\"}},\"CheckType\":\"\",\"S1\":\"\",\"S2\":\"\",\"S3\":\"\",\"S4\":\"\",\"S5\":\"\",\"S6\":\"\",\"S7\":\"\",\"S8\":\"\",\"S9\":\"Pratik\",\"S10\":\"\",\"ScoreIfNoMatch\":\"2\"},{\"Question\":{\"QuestionId\":51,\"QuestionText\":\"Are you smart?\",\"TypeId\":3,\"TypeName\":\"True-False\",\"Model\":{\"options\":[{\"text\":\"True\",\"selectedMarks\":\"7\"},{\"text\":\"False\",\"selectedMarks\":\"0\"}],\"maxOptions\":10,\"minOptions\":0,\"isAnswerRequired\":false,\"selectedOption\":\"3\",\"answerText\":\"\",\"isRangeType\":false,\"from\":\"\",\"to\":\"\",\"mins\":\"01\",\"secs\":\"04\"}},\"CheckType\":\"\",\"S1\":\"\",\"S2\":\"\",\"S3\":\"\",\"S4\":\"\",\"S5\":\"\",\"S6\":\"\",\"S7\":\"True\",\"S8\":\"\",\"S9\":\"\",\"S10\":\"\",\"ScoreIfNoMatch\":\"2\"}]";
        dynamic myObject = JValue.Parse(jsonString);
        foreach (dynamic questions in myObject)
        {
            Console.WriteLine(questions.Question.QuestionId + "." + questions.Question.QuestionText.ToString());
        }
        Console.Read();

Output from the code => Output from the code

How to scroll table's "tbody" independent of "thead"?

mandatory parts:

tbody {
    overflow-y: scroll;  (could be: 'overflow: scroll' for the two axes)
    display: block;
    with: xxx (a number or 100%)
}

thead {
    display: inline-block;
}

.htaccess redirect www to non-www with SSL/HTTPS

Certificate must cover both www and non-www https. Some provider's certs cover both for www.xxxx.yyy, but only one for xxxx.yyy.

Turn on rewrites:

RewriteEngine On

Make all http use https:

RewriteCond %{SERVER_PORT} 80
RewriteRule ^(.*)$ https://xxx.yyy/$1 [L,R=301]

Make only www https use the non-www https:

RewriteCond %{SERVER_PORT} 443
RewriteCond %{HTTP_HOST} ^www[.].+$
RewriteRule ^(.*)$ https://xxxx.yyy/$1 [L,R=301]

Cannot be processing non-www https, otherwise a loop occurs.

In [L,R=301]:

  1. L = If the rule was processed, don't process any more.
  2. R=301 = Tells browser/robot to do a permanent redirect.

More generic

A more generic approach -- not port-dependant -- is:

RewriteCond %{HTTP_HOST} ^www\.
RewriteRule ^(.*)$ https://xxxx.yyy/$1 [R=301,QSA]

to make any url with www drop it.

RewriteCond %{HTTPS} !on
RewriteCond %{HTTPS} !1
RewriteCond %{HTTP:X-Forwarded-Proto} !https
RewriteCond %{HTTP:X-Forwarded-SSL} !on
RewriteRule ^(.*)$ https://xxxx.yyy/$1 [R=301,QSA]

to force any non-https url, even for those system downstream from load-balancers that drop https, use https.

Note that I have not tested the forwarded options, so would appreciate feedback on any issues with them. Those lines could be left out if your system is not behind a load-balancer.

TO HTTP_HOST or not

You can use ${HTTP_HOST} to be part of the URL in the RewriteRule, or you can use your explicit canonical domain name text (xxxx.yyy above).

Specifying the domain name explicitly ensures that no slight-of-hand character-bending means are used in the user-supplied URL to possibly trick your site into doing something it might not be prepared for, or at least ensures that the proper domain name appears in the address bar, regardless of which URL string opened the page.

It might even help convert punycode-encoded domains to show the proper unicode characters in the address bar.

Usage of $broadcast(), $emit() And $on() in AngularJS

  • Broadcast: We can pass the value from parent to child (i.e parent -> child controller.)
  • Emit: we can pass the value from child to parent (i.e.child ->parent controller.)
  • On: catch the event dispatched by $broadcast or $emit.

What is a callback?

A callback lets you pass executable code as an argument to other code. In C and C++ this is implemented as a function pointer. In .NET you would use a delegate to manage function pointers.

A few uses include error signaling and controlling whether a function acts or not.

Wikipedia

How to use getJSON, sending data with post method?

I just used post and an if:

data = getDataObjectByForm(form);
var jqxhr = $.post(url, data, function(){}, 'json')
    .done(function (response) {
        if (response instanceof Object)
            var json = response;
        else
            var json = $.parseJSON(response);
        // console.log(response);
        // console.log(json);
        jsonToDom(json);
        if (json.reload != undefined && json.reload)
            location.reload();
        $("body").delay(1000).css("cursor", "default");
    })
    .fail(function (jqxhr, textStatus, error) {
        var err = textStatus + ", " + error;
        console.log("Request Failed: " + err);
        alert("Fehler!");
    });

How do I read configuration settings from Symfony2 config.yml?

Rather than defining contact_email within app.config, define it in a parameters entry:

parameters:
    contact_email: [email protected]

You should find the call you are making within your controller now works.

Convert seconds value to hours minutes seconds?

If you want the units h, min and sec for a duration you can use this:

public static String convertSeconds(int seconds) {
    int h = seconds/ 3600;
    int m = (seconds % 3600) / 60;
    int s = seconds % 60;
    String sh = (h > 0 ? String.valueOf(h) + " " + "h" : "");
    String sm = (m < 10 && m > 0 && h > 0 ? "0" : "") + (m > 0 ? (h > 0 && s == 0 ? String.valueOf(m) : String.valueOf(m) + " " + "min") : "");
    String ss = (s == 0 && (h > 0 || m > 0) ? "" : (s < 10 && (h > 0 || m > 0) ? "0" : "") + String.valueOf(s) + " " + "sec");
    return sh + (h > 0 ? " " : "") + sm + (m > 0 ? " " : "") + ss;
}

int seconds = 3661;
String duration = convertSeconds(seconds);

That's a lot of conditional operators. The method will return those strings:

0    -> 0 sec
5    -> 5 sec
60   -> 1 min
65   -> 1 min 05 sec
3600 -> 1 h
3601 -> 1 h 01 sec
3660 -> 1 h 01
3661 -> 1 h 01 min 01 sec
108000 -> 30 h

How do you read from stdin?

Building on all the anwers using sys.stdin, you can also do something like the following to read from an argument file if at least one argument exists, and fall back to stdin otherwise:

import sys
f = open(sys.argv[1]) if len(sys.argv) > 1 else sys.stdin    
for line in f:
#     Do your stuff

and use it as either

$ python do-my-stuff.py infile.txt

or

$ cat infile.txt | python do-my-stuff.py

or even

$ python do-my-stuff.py < infile.txt

That would make your Python script behave like many GNU/Unix programs such as cat, grep and sed.

How to redirect the output of an application in background to /dev/null

You use:

yourcommand  > /dev/null 2>&1

If it should run in the Background add an &

yourcommand > /dev/null 2>&1 &

>/dev/null 2>&1 means redirect stdout to /dev/null AND stderr to the place where stdout points at that time

If you want stderr to occur on console and only stdout going to /dev/null you can use:

yourcommand 2>&1 > /dev/null

In this case stderr is redirected to stdout (e.g. your console) and afterwards the original stdout is redirected to /dev/null

If the program should not terminate you can use:

nohup yourcommand &

Without any parameter all output lands in nohup.out

PHP expects T_PAAMAYIM_NEKUDOTAYIM?

From Wikipedia:

In PHP, the scope resolution operator is also called Paamayim Nekudotayim (Hebrew: ?????? ?????????), which means “double colon” in Hebrew.

The name "Paamayim Nekudotayim" was introduced in the Israeli-developed Zend Engine 0.5 used in PHP 3. Although it has been confusing to many developers who do not speak Hebrew, it is still being used in PHP 5, as in this sample error message:

$ php -r :: Parse error: syntax error, unexpected T_PAAMAYIM_NEKUDOTAYIM

As of PHP 5.4, error messages concerning the scope resolution operator still include this name, but have clarified its meaning somewhat:

$ php -r :: Parse error: syntax error, unexpected '::' (T_PAAMAYIM_NEKUDOTAYIM)

From the official PHP documentation:

The Scope Resolution Operator (also called Paamayim Nekudotayim) or in simpler terms, the double colon, is a token that allows access to static, constant, and overridden properties or methods of a class.

When referencing these items from outside the class definition, use the name of the class.

As of PHP 5.3.0, it's possible to reference the class using a variable. The variable's value can not be a keyword (e.g. self, parent and static).

Paamayim Nekudotayim would, at first, seem like a strange choice for naming a double-colon. However, while writing the Zend Engine 0.5 (which powers PHP 3), that's what the Zend team decided to call it. It actually does mean double-colon - in Hebrew!

How to use responsive background image in css3 in bootstrap

Try this:

body {
  background-image:url(img/background.jpg);
  background-repeat: no-repeat;
  min-height: 679px;
  background-size: cover;
}

String formatting: % vs. .format vs. string literal

As I discovered today, the old way of formatting strings via % doesn't support Decimal, Python's module for decimal fixed point and floating point arithmetic, out of the box.

Example (using Python 3.3.5):

#!/usr/bin/env python3

from decimal import *

getcontext().prec = 50
d = Decimal('3.12375239e-24') # no magic number, I rather produced it by banging my head on my keyboard

print('%.50f' % d)
print('{0:.50f}'.format(d))

Output:

0.00000000000000000000000312375239000000009907464850 0.00000000000000000000000312375239000000000000000000

There surely might be work-arounds but you still might consider using the format() method right away.

Changing default startup directory for command prompt in Windows 7

Keep the opening of the command prompt clean. Avoid editing the registry key and adding an Autorun, it may come back to bite you.
Create a simple batch file and save it in the C:\Windows or C:\Windows\System32 folder. I call mine !.bat (exclamation mark). It has the following commands:

@echo off c: cd \ cls whoami

It goes to the folder where I need to work, clears the screen and tells me what security context I'm in.

How do I search for an object by its ObjectId in the mongo console?

Once you opened the mongo CLI, connected and authorized on the right database.

The following example shows how to find the document with the _id=568c28fffc4be30d44d0398e from a collection called “products”:

db.products.find({"_id": ObjectId("568c28fffc4be30d44d0398e")})

How to symbolicate crash log Xcode?

Apple gives you crash log in .txt format , which is unsymbolicated

**

With the device connected

**

  • Download ".txt" file , change extension to ".crash" enter image description here
    • Open devices and simulators from window tab in Xcode
    • select device and select device logs
    • drag and drop .crash file to the device log window

enter image description here

We will be able to see symbolicated crash logs over there

Please see the link for more details on Symbolicating Crash logs

SQL Server - Convert varchar to another collation (code page) to fix character encoding

We may need more information. Here is what I did to reproduce on SQL Server 2008:

CREATE DATABASE [Test] ON  PRIMARY 
    ( 
    NAME = N'Test'
    , FILENAME = N'...Test.mdf' 
    , SIZE = 3072KB 
    , FILEGROWTH = 1024KB 
    )
    LOG ON 
    ( 
    NAME = N'Test_log'
    , FILENAME = N'...Test_log.ldf' 
    , SIZE = 1024KB 
    , FILEGROWTH = 10%
    )
    COLLATE SQL_Latin1_General_CP850_BIN2
GO
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
SET ANSI_PADDING ON
GO
CREATE TABLE [dbo].[MyTable]
    (
    [SomeCol] [varchar](50) NULL
    ) ON [PRIMARY]
GO
Insert MyTable( SomeCol )
Select '±' Collate SQL_Latin1_General_CP1_CI_AS
GO
Select SomeCol, SomeCol Collate SQL_Latin1_General_CP1_CI_AS
From MyTable

Results show the original character. Declaring collation in the query should return the proper character from SQL Server's perspective however it may be the case that the presentation layer is then converting to something yet different like UTF-8.

SQL Server: UPDATE a table by using ORDER BY

IF OBJECT_ID('tempdb..#TAB') IS NOT NULL
BEGIN
    DROP TABLE #TAB
END

CREATE TABLE #TAB(CH1 INT,CH2 INT,CH3 INT)

DECLARE @CH2 INT = NULL , @CH3 INT=NULL,@SPID INT=NULL,@SQL NVARCHAR(4000)='', @ParmDefinition NVARCHAR(50)= '',
@RET_MESSAGE AS VARCHAR(8000)='',@RET_ERROR INT=0


SET @ParmDefinition='@SPID INT,@CH2 INT OUTPUT,@CH3 INT OUTPUT'

SET @SQL='UPDATE T
            SET CH1=@SPID,@CH2= T.CH2,@CH3= T.CH3
            FROM #TAB T WITH(ROWLOCK)
            INNER JOIN (
                        SELECT TOP(1)  CH1,CH2,CH3
                        FROM
                        #TAB WITH(NOLOCK)
                        WHERE CH1 IS NULL
                        ORDER BY CH2 DESC) V ON T.CH2= V.CH2 AND T.CH3= V.CH3' 

INSERT INTO #TAB
(CH2 ,CH3 )
SELECT 1,2 UNION ALL
SELECT 2,3 UNION ALL
SELECT 3,4

BEGIN TRY
    WHILE EXISTS(SELECT TOP 1 1 FROM #TAB WHERE CH1 IS NULL)
    BEGIN

        EXECUTE @RET_ERROR = sp_executesql @SQL, @ParmDefinition,@SPID =@@SPID,  @CH2=@CH2 OUTPUT,@CH3=@CH3 OUTPUT;  

        SELECT * FROM #TAB
        SELECT @CH2,@CH3

    END

END TRY
BEGIN CATCH

    SET @RET_ERROR=ERROR_NUMBER()
    SET @RET_MESSAGE =  '@ERROR_NUMBER : ' + CAST(ERROR_NUMBER()  AS VARCHAR(255)) + '@ERROR_SEVERITY  :' + CAST( ERROR_SEVERITY()  AS VARCHAR(255)) 
    + '@ERROR_STATE :' + CAST(ERROR_STATE() AS VARCHAR(255)) + '@ERROR_LINE :' + CAST( ERROR_LINE() AS VARCHAR(255)) 
    +  '@ERROR_MESSAGE :' + ERROR_MESSAGE()  ;

    SELECT @RET_ERROR,@RET_MESSAGE;

END CATCH

Webdriver findElements By xpath

The XPath turns into this:

Get me all of the div elements that have an id equal to container.

As for getting the first etc, you have two options.

Turn it into a .findElement() - this will just return the first one for you anyway.

or

To explicitly do this in XPath, you'd be looking at:

(//div[@id='container'])[1]

for the first one, for the second etc:

(//div[@id='container'])[2]

Then XPath has a special indexer, called last, which would (you guessed it) get you the last element found:

(//div[@id='container'])[last()]

Worth mentioning that XPath indexers will start from 1 not 0 like they do in most programming languages.

As for getting the parent 'node', well, you can use parent:

//div[@id='container']/parent::*

That would get the div's direct parent.

You could then go further and say I want the first *div* with an id of container, and I want his parent:

(//div[@id='container'])[1]/parent::*

Hope that helps!

C++ float array initialization

No, it sets all members/elements that haven't been explicitly set to their default-initialisation value, which is zero for numeric types.

ASP.NET MVC ActionLink and post method

Calling $.post() won't work as it is Ajax based. So a hybrid method needs to be used for this purpose.

Following is the solution which is working for me.

Steps: 1. Create URL for href which calls the a method with url and parameter 2. Call normal POST using JavaScript method

Solution:

In .cshtml:

<a href="javascript:(function(){$.postGo( '@Url.Action("View")', { 'id': @receipt.ReceiptId  } );})()">View</a>

Note: the anonymous method should be wrapped in (....)() i.e.

(function() {
    //code...
})();

postGo is defined as below in JavaScript. Rest are simple..

@Url.Action("View") creates url for the call

{ 'id': @receipt.ReceiptId } creates parameters as object which is in-turn converted to POST fields in postGo method. This can be any parameter as you require

In JavaScript:

(function ($) {
    $.extend({
        getGo: function (url, params) {
            document.location = url + '?' + $.param(params);
        },
        postGo: function (url, params) {
            var $form = $("<form>")
                .attr("method", "post")
                .attr("action", url);
            $.each(params, function (name, value) {
                $("<input type='hidden'>")
                    .attr("name", name)
                    .attr("value", value)
                    .appendTo($form);
            });
            $form.appendTo("body");
            $form.submit();
        }
    });
})(jQuery);

Reference URLs which I have used for postGo

Non-ajax GET/POST using jQuery (plugin?)

http://nuonical.com/jquery-postgo-plugin/

How can I save multiple documents concurrently in Mongoose/Node.js?

You can use the promise returned by mongoose save, Promise in mongoose does not have all, but you can add the feature with this module.

Create a module that enhance mongoose promise with all.

var Promise = require("mongoose").Promise;

Promise.all = function(promises) {
  var mainPromise = new Promise();
  if (promises.length == 0) {
    mainPromise.resolve(null, promises);
  }

  var pending = 0;
  promises.forEach(function(p, i) {
    pending++;
    p.then(function(val) {
      promises[i] = val;
      if (--pending === 0) {
        mainPromise.resolve(null, promises);
      }
    }, function(err) {
      mainPromise.reject(err);
    });
  });

  return mainPromise;
}

module.exports = Promise;

Then use it with mongoose:

var Promise = require('./promise')

...

var tasks = [];

for (var i=0; i < docs.length; i++) {
  tasks.push(docs[i].save());
}

Promise.all(tasks)
  .then(function(results) {
    console.log(results);
  }, function (err) {
    console.log(err);
  })

Change tab bar tint color on iOS 7

In "Attributes Inspector" of your Tab Bar Controller within Interface Builder make sure your Bottom Bar is set to Opaque Tab Bar:

Choose Opaque

Now goto your AppDelegate.m file. Find:

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions

And then add this code between the curly braces to change the colors of both the tab bar buttons and the tab bar background:

///----------------SET TAB BAR COLOR------------------------//

//--------------FOR TAB BAR BUTTON COLOR---------------//
[[UITabBar appearance] setTintColor:[UIColor greenColor]];

//-------------FOR TAB BAR BACKGROUND COLOR------------//
[[UITabBar appearance] setBarTintColor:[UIColor whiteColor]];

Parsing a JSON string in Ruby

As of Ruby v1.9.3 you don't need to install any Gems in order to parse JSON, simply use require 'json':

require 'json'

json = JSON.parse '{"foo":"bar", "ping":"pong"}'
puts json['foo'] # prints "bar"

See JSON at Ruby-Doc.

How to make a new List in Java

Try this:

List<String> messages = Arrays.asList("bla1", "bla2", "bla3");

Or:

List<String> list1 = Lists.mutable.empty(); // Empty
List<String> list2 = Lists.mutable.of("One", "Two", "Three");

Keyboard shortcuts in WPF

Documenting this answer for others, as there is a much simpler way to do this that is rarely referenced, and doesn't require touching the XAML at all.

To link a keyboard shortcut, in the Window constructor simply add a new KeyBinding to the InputBindings collection. As the command, pass in your arbitrary command class that implements ICommand. For the execute method, simply implement whatever logic you need. In my example below, my WindowCommand class takes a delegate that it will execute whenever invoked. When I construct the new WindowCommand to pass in with my binding, I simply indicate in my initializer, the method that I want the WindowCommand to execute.

You can use this pattern to come up with your own quick keyboard shortcuts.

public YourWindow() //inside any WPF Window constructor
{
   ...
   //add this one statement to bind a new keyboard command shortcut
   InputBindings.Add(new KeyBinding( //add a new key-binding, and pass in your command object instance which contains the Execute method which WPF will execute
      new WindowCommand(this)
      {
         ExecuteDelegate = TogglePause //REPLACE TogglePause with your method delegate
      }, new KeyGesture(Key.P, ModifierKeys.Control)));
   ...
}

Create a simple WindowCommand class which takes an execution delegate to fire off any method set on it.

public class WindowCommand : ICommand
{
    private MainWindow _window;

    //Set this delegate when you initialize a new object. This is the method the command will execute. You can also change this delegate type if you need to.
    public Action ExecuteDelegate { get; set; }

    //You don't have to add a parameter that takes a constructor. I've just added one in case I need access to the window directly.
    public WindowCommand(MainWindow window)
    {
        _window = window;
    }

    //always called before executing the command, mine just always returns true
    public bool CanExecute(object parameter)
    {
        return true; //mine always returns true, yours can use a new CanExecute delegate, or add custom logic to this method instead.
    }

    public event EventHandler CanExecuteChanged; //i'm not using this, but it's required by the interface

    //the important method that executes the actual command logic
    public void Execute(object parameter)
    {
        if (ExecuteDelegate != null)
        {
            ExecuteDelegate();
        }
        else
        {
            throw new InvalidOperationException();
        }
    }
}

How to avoid the "divide by zero" error in SQL?

SELECT Dividend / ISNULL(NULLIF(Divisor,0), 1) AS Result from table

By catching the zero with a nullif(), then the resulting null with an isnull() you can circumvent your divide by zero error.

How to check if a div is visible state or not?

You can use (':hidden') method to find if your div is visible or not.. Also its a good practice to cache a element if you are using it multiple times in your code..

$(".subpanel a").click(function() 
     {
        var chatterNickname = $(this).text();
        var $chatPanel = $("#singlechatpanel-1");

        if(!$chatPanel.is(':hidden'))
        {
            alert("Room 1 is filled.");
            $chatPanel.show();
            $("#singlechatpanel-1 #chatter_nickname").html("Chatting with: " + chatterNickname);
        }
});

Google Text-To-Speech API

Allright, so Google has introduces tokens (see the tk parameter in the new url) and the old solution doesn't seem to work. I've found an alternative - which I even think is better-sounding, and has more voices! The command isn't pretty, but it works. Please note that this is for testing purposes only (I use it for a little domotica project) and use the real version from acapella-group if you're planning on using this commercially.

curl $(curl --data 'MyLanguages=sonid10&MySelectedVoice=Sharon&MyTextForTTS=Hello%20World&t=1&SendToVaaS=' 'http://www.acapela-group.com/demo-tts/DemoHTML5Form_V2.php' | grep -o "http.*mp3") > tts_output.mp3

Some of the supported voices are;

  • Sharon
  • Ella (genuine child voice)
  • EmilioEnglish (genuine child voice)
  • Josh (genuine child voice)
  • Karen
  • Kenny (artificial child voice)
  • Laura
  • Micah
  • Nelly (artificial child voice)
  • Rod
  • Ryan
  • Saul
  • Scott (genuine teenager voice)
  • Tracy
  • ValeriaEnglish (genuine child voice)
  • Will
  • WillBadGuy (emotive voice)
  • WillFromAfar (emotive voice)
  • WillHappy (emotive voice)
  • WillLittleCreature (emotive voice)
  • WillOldMan (emotive voice)
  • WillSad (emotive voice)
  • WillUpClose (emotive voice)

It also supports multiple languages and more voices - for that I refer you to their website; http://www.acapela-group.com/

Running Groovy script from the command line

It will work on Linux kernel 2.6.28 (confirmed on 4.9.x). It won't work on FreeBSD and other Unix flavors.

Your /usr/local/bin/groovy is a shell script wrapping the Java runtime running Groovy.

See the Interpreter Scripts section of EXECVE(2) and EXECVE(2).

How to clear mysql screen console in windows?

For Window 10

Use the command system cls and this will clear the MYSQL Command Line window in Windows

Titlecase all entries into a form_for text field

You don't want to take care of normalizing your data in a view - what if the user changes the data that gets submitted? Instead you could take care of it in the model using the before_save (or the before_validation) callback. Here's an example of the relevant code for a model like yours:

class Place < ActiveRecord::Base   before_save do |place|     place.city = place.city.downcase.titleize     place.country = place.country.downcase.titleize   end end 

You can also check out the Ruby on Rails guide for more info.


To answer you question more directly, something like this would work:

<%= f.text_field :city, :value => (f.object.city ? f.object.city.titlecase : '') %>   

This just means if f.object.city exists, display the titlecase version of it, and if it doesn't display a blank string.

How to sort an ArrayList?

In JAVA 8 its much easy now.

List<String> alphaNumbers = Arrays.asList("one", "two", "three", "four");
List<String> alphaNumbersUpperCase = alphaNumbers.stream()
    .map(String::toUpperCase)
    .sorted()
    .collect(Collectors.toList());
System.out.println(alphaNumbersUpperCase); // [FOUR, ONE, THREE, TWO]

-- For reverse use this

.sorted(Comparator.reverseOrder())

How do I raise an exception in Rails so it behaves like other Rails exceptions?

You don't have to do anything special, it should just be working.

When I have a fresh rails app with this controller:

class FooController < ApplicationController
  def index
    raise "error"
  end
end

and go to http://127.0.0.1:3000/foo/

I am seeing the exception with a stack trace.

You might not see the whole stacktrace in the console log because Rails (since 2.3) filters lines from the stack trace that come from the framework itself.

See config/initializers/backtrace_silencers.rb in your Rails project

TypeScript and React - children type?

This is what worked for me:

interface Props {
  children: JSX.Element[] | JSX.Element
}

Edit I would recommend using children: React.ReactNode instead now.

"Are you missing an assembly reference?" compile error - Visual Studio

Are you strong-naming your assemblies? In that case it is not a good idea to auto-increment your build number because with every new build number you will also have to update all your references.

How do I efficiently iterate over each entry in a Java Map?

In Map one can Iteration over keys and/or values and/or both (e.g., entrySet) depends on one's interested in_ Like:

  1. Iterate through the keys -> keySet() of the map:

     Map<String, Object> map = ...;
    
     for (String key : map.keySet()) {
         //your Business logic...
     }
    
  2. Iterate through the values -> values() of the map:

     for (Object value : map.values()) {
         //your Business logic...
     }
    
  3. Iterate through the both -> entrySet() of the map:

     for (Map.Entry<String, Object> entry : map.entrySet()) {
         String key = entry.getKey();
         Object value = entry.getValue();
         //your Business logic...
     }
    

Moreover, there are 3 different ways to iterate through a HashMap. They are as below:

//1.
for (Map.Entry entry : hm.entrySet()) {
    System.out.print("key,val: ");
    System.out.println(entry.getKey() + "," + entry.getValue());
}

//2.
Iterator iter = hm.keySet().iterator();
while(iter.hasNext()) {
    Integer key = (Integer)iter.next();
    String val = (String)hm.get(key);
    System.out.println("key,val: " + key + "," + val);
}

//3.
Iterator it = hm.entrySet().iterator();
while (it.hasNext()) {
    Map.Entry entry = (Map.Entry) it.next();
    Integer key = (Integer)entry.getKey();
    String val = (String)entry.getValue();
    System.out.println("key,val: " + key + "," + val);
}

Change Project Namespace in Visual Studio

Just right click on the name you want to change (this could be namespace or whatever else) and select Refactor->Rename...

Enter new name, leave location as [Global Namespace], check preview if you want and you're done!

PHP json_decode() returns NULL with valid JSON?

For my case, it's because of the single quote in JSON string.

JSON format only accepts double-quotes for keys and string values.

Example:

$jsonString = '{\'hello\': \'PHP\'}'; // valid value should be '{"hello": "PHP"}'
$json = json_decode($jsonString);
print $json; // null

I got this confused because of Javascript syntax. In Javascript, of course, we can do like this:

let json = {
    hello: 'PHP' // no quote for key, single quote for string value
}

// OR:
json = {
    'hello': 'PHP' // single quote for key and value
}

but later when convert those objects to JSON string:

JSON.stringify(json); // "{"hello":"PHP"}"

How to Free Inode Usage?

eaccelerator could be causing the problem since it compiles PHP into blocks...I've had this problem with an Amazon AWS server on a site with heavy load. Free up Inodes by deleting the eaccelerator cache in /var/cache/eaccelerator if you continue to have issues.

rm -rf /var/cache/eaccelerator/*

(or whatever your cache dir)

CMD: How do I recursively remove the "Hidden"-Attribute of files and directories

To launch command prompt in administrator mode

  1. Type cmd in Search and hold Crtl+Shift to open in administrator mode
  2. Type attrib -h -r -s /s /d "location of the drive letter:" \*.*

Add data to JSONObject

The answer is to use a JSONArray as well, and to dive "deep" into the tree structure:

JSONArray arr = new JSONArray();
arr.put (...); // a new JSONObject()
arr.put (...); // a new JSONObject()

JSONObject json = new JSONObject();
json.put ("aoColumnDefs",arr);

PHP string concatenation

while ($personCount < 10) {
    $result .= ($personCount++)." people ";
}

echo $result;

Java int to String - Integer.toString(i) vs new Integer(i).toString()

Another option is the static String.valueOf method.

String.valueOf(i)

It feels slightly more right than Integer.toString(i) to me. When the type of i changes, for example from int to double, the code will stay correct.

How to check if a column exists in Pandas

To check if one or more columns all exist, you can use set.issubset, as in:

if set(['A','C']).issubset(df.columns):
   df['sum'] = df['A'] + df['C']                

As @brianpck points out in a comment, set([]) can alternatively be constructed with curly braces,

if {'A', 'C'}.issubset(df.columns):

See this question for a discussion of the curly-braces syntax.

Or, you can use a list comprehension, as in:

if all([item in df.columns for item in ['A','C']]):

Writelines writes lines without newline, Just fills the file

The documentation for writelines() states:

writelines() does not add line separators

So you'll need to add them yourself. For example:

    line_list.append(new_line + "\n")

whenever you append a new item to line_list.

Checking for directory and file write permissions in .NET

Deny takes precedence over Allow. Local rules take precedence over inherited rules. I have seen many solutions (including some answers shown here), but none of them takes into account whether rules are inherited or not. Therefore I suggest the following approach that considers rule inheritance (neatly wrapped into a class):

public class CurrentUserSecurity
{
    WindowsIdentity _currentUser;
    WindowsPrincipal _currentPrincipal;

    public CurrentUserSecurity()
    {
        _currentUser = WindowsIdentity.GetCurrent();
        _currentPrincipal = new WindowsPrincipal(_currentUser);
    }

    public bool HasAccess(DirectoryInfo directory, FileSystemRights right)
    {
        // Get the collection of authorization rules that apply to the directory.
        AuthorizationRuleCollection acl = directory.GetAccessControl()
            .GetAccessRules(true, true, typeof(SecurityIdentifier));
        return HasFileOrDirectoryAccess(right, acl);
    }

    public bool HasAccess(FileInfo file, FileSystemRights right)
    {
        // Get the collection of authorization rules that apply to the file.
        AuthorizationRuleCollection acl = file.GetAccessControl()
            .GetAccessRules(true, true, typeof(SecurityIdentifier));
        return HasFileOrDirectoryAccess(right, acl);
    }

    private bool HasFileOrDirectoryAccess(FileSystemRights right,
                                          AuthorizationRuleCollection acl)
    {
        bool allow = false;
        bool inheritedAllow = false;
        bool inheritedDeny = false;

        for (int i = 0; i < acl.Count; i++) {
            var currentRule = (FileSystemAccessRule)acl[i];
            // If the current rule applies to the current user.
            if (_currentUser.User.Equals(currentRule.IdentityReference) ||
                _currentPrincipal.IsInRole(
                                (SecurityIdentifier)currentRule.IdentityReference)) {

                if (currentRule.AccessControlType.Equals(AccessControlType.Deny)) {
                    if ((currentRule.FileSystemRights & right) == right) {
                        if (currentRule.IsInherited) {
                            inheritedDeny = true;
                        } else { // Non inherited "deny" takes overall precedence.
                            return false;
                        }
                    }
                } else if (currentRule.AccessControlType
                                                  .Equals(AccessControlType.Allow)) {
                    if ((currentRule.FileSystemRights & right) == right) {
                        if (currentRule.IsInherited) {
                            inheritedAllow = true;
                        } else {
                            allow = true;
                        }
                    }
                }
            }
        }

        if (allow) { // Non inherited "allow" takes precedence over inherited rules.
            return true;
        }
        return inheritedAllow && !inheritedDeny;
    }
}

However, I made the experience that this does not always work on remote computers as you will not always have the right to query the file access rights there. The solution in that case is to try; possibly even by just trying to create a temporary file, if you need to know the access right before working with the "real" files.

CSS: How to align vertically a "label" and "input" inside a "div"?

I'm aware this question was asked over two years ago, but for any recent viewers, here's an alternative solution, which has a few advantages over Marc-François's solution:

div {
    height: 50px;
    border: 1px solid blue;
    line-height: 50px;
}

Here we simply only add a line-height equal to that of the height of the div. The advantage being you can now change the display property of the div as you see fit, to inline-block for instance, and it's contents will remain vertically centered. The accepted solution requires you treat the div as a table cell. This should work perfectly, cross-browser.

The only other advantage being it's just one more CSS rule instead of two :)

Cheers!

Fixed positioned div within a relative parent div

A simple thing you can do is position your fixed DIV relative to the rest of your page with % values.

Check out this jsfiddle here where the fixed DIV is a sidebar.

div#wrapper {
    margin: auto;
    width: 80%;
}

div#main {
    width: 60%;
}

div#sidebar {
    position: fixed;
    width: 30%;
    left: 60%;
}

And a brief picture below describing the layout above:

example layout

The CSRF token is invalid. Please try to resubmit the form

I had the same error, but in my case the problem was that my application was using multiple first-level domains, while the cookie was using one. Removing cookie_domain: ".%domain%" from framework.session in the config.yml caused cookies to default to whatever domain the form was on, and that fixed the problem.

SQL DELETE with JOIN another table for WHERE condition

Due to the locking implementation issues, MySQL does not allow referencing the affected table with DELETE or UPDATE.

You need to make a JOIN here instead:

DELETE  gc.*
FROM    guide_category AS gc 
LEFT JOIN
        guide AS g 
ON      g.id_guide = gc.id_guide
WHERE   g.title IS NULL

or just use a NOT IN:

DELETE  
FROM    guide_category AS gc 
WHERE   id_guide NOT IN
        (
        SELECT  id_guide
        FROM    guide
        )

How to change UINavigationBar background color from the AppDelegate

You can set UINavigation Background color by using this code in any view controller

self.navigationController.navigationBar.backgroundColor = [UIColor colorWithRed:10.0f/255.0f green:30.0f/255.0f blue:200.0f/255.0f alpha:1.0f];

bower proxy configuration

The key for me was adding an extra line, "strict-ssl": false

Create .bowerrc on root folder, and add the following,

{
  "directory": "bower_components", // If you change this, your folder named will change within dependecies. EX) Vendors instead of bower_components.
  "proxy": "http://yourProxy:yourPort",
  "https-proxy":"http://yourProxy:yourPort",
  "strict-ssl": false 
}

Best of luck for the people still stuck on this.

SQL Server : login success but "The database [dbName] is not accessible. (ObjectExplorer)"

Issue: The database [dbName] is not accessible. (ObjectExplorer) got the error when expanding the database.

Solution: Deattach the database > Drop Option Attach the database again with the mdf file under the mssql data folder

ASP.net using a form to insert data into an sql server table

Simple, make a simple asp page with the designer (just for the beginning) Lets say the body is something like this:

<body>
    <form id="form1" runat="server">
    <div>
        <asp:TextBox ID="TextBox2" runat="server"></asp:TextBox>
        <br />
        <asp:TextBox ID="TextBox1" runat="server"></asp:TextBox>
    </div>
    <p>
        <asp:Button ID="Button1" runat="server" Text="Button" />
    </p>
    </form>
</body>

Great, now every asp object IS an object. So you can access it in the asp's CS code. The asp's CS code is triggered by events (mostly). The class will probably inherit from System.Web.UI.Page

If you go to the cs file of the asp page, you'll see a protected void Page_Load(object sender, EventArgs e) ... That's the load event, you can use that to populate data into your objects when the page loads.

Now, go to the button in your designer (Button1) and look at its properties, you can design it, or add events from there. Just change to the events view, and create a method for the event.

The button is a web control Button Add a Click event to the button call it Button1Click:

void Button1Click(Object sender,EventArgs e) { }

Now when you click the button, this method will be called. Because ASP is object oriented, you can think of the page as the actual class, and the objects will hold the actual current data.

So if for example you want to access the text in TextBox1 you just need to call that object in the C# code:

String firstBox = TextBox1.Text;

In the same way you can populate the objects when event occur.

Now that you have the data the user posted in the textboxes , you can use regular C# SQL connections to add the data to your database.

Differences between Lodash and Underscore.js

Lodash is inspired by Underscore.js, but nowadays it is a superior solution. You can make your custom builds, have a higher performance, support AMD and have great extra features. Check this Lodash vs. Underscore.js benchmarks on jsperf and... this awesome post about Lodash:

One of the most useful feature when you work with collections, is the shorthand syntax:

var characters = [
  { 'name': 'barney', 'age': 36, 'blocked': false },
  { 'name': 'fred',   'age': 40, 'blocked': true }
];

// Using "_.filter" callback shorthand
_.filter(characters, { 'age': 36 });

// Using Underscore.js
_.filter(characters, function(character) { return character.age === 36; } );

// ? [{ 'name': 'barney', 'age': 36, 'blocked': false }]

(taken from Lodash documentation)

Create a date time with month and day only, no year

How about creating a timer with the next date?

In your timer callback you create the timer for the following year? DateTime has always a year value. What you want to express is a recurring time specification. This is another type which you would need to create. DateTime is always represents a specific date and time but not a recurring date.

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

strftime (C89)

Martin mentioned it, here's an example:

main.c

#include <assert.h>
#include <stdio.h>
#include <time.h>

int main(void) {
    time_t t = time(NULL);
    struct tm *tm = localtime(&t);
    char s[64];
    assert(strftime(s, sizeof(s), "%c", tm));
    printf("%s\n", s);
    return 0;
}

GitHub upstream.

Compile and run:

gcc -std=c89 -Wall -Wextra -pedantic -o main.out main.c
./main.out

Sample output:

Thu Apr 14 22:39:03 2016

The %c specifier produces the same format as ctime.

One advantage of this function is that it returns the number of bytes written, allowing for better error control in case the generated string is too long:

RETURN VALUE

  Provided  that  the  result string, including the terminating null byte, does not exceed max bytes, strftime() returns the number of bytes (excluding the terminating null byte) placed in the array s.  If the length of the result string (including the terminating null byte) would exceed max bytes, then
   strftime() returns 0, and the contents of the array are undefined.
  Note that the return value 0 does not necessarily indicate an error.  For example, in many locales %p yields an empty string.  An empty format string will likewise yield an empty string.

asctime and ctime (C89, deprecated in POSIX 7)

asctime is a convenient way to format a struct tm:

main.c

#include <stdio.h>
#include <time.h>

int main(void) {
    time_t t = time(NULL);
    struct tm *tm = localtime(&t);
    printf("%s", asctime(tm));
    return 0;
}

Sample output:

Wed Jun 10 16:10:32 2015

And there is also ctime() which the standard says is a shortcut for:

asctime(localtime())

As mentioned by Jonathan Leffler, the format has the shortcoming of not having timezone information.

POSIX 7 marked those functions as "obsolescent" so they could be removed in future versions:

The standard developers decided to mark the asctime() and asctime_r() functions obsolescent even though asctime() is in the ISO C standard due to the possibility of buffer overflow. The ISO C standard also provides the strftime() function which can be used to avoid these problems.

C++ version of this question: How to get current time and date in C++?

Tested in Ubuntu 16.04.

ASP.NET MVC Html.DropDownList SelectedValue

This is how I fixed this problem:

I had the following:

Controller:

ViewData["DealerTypes"] = Helper.SetSelectedValue(listOfValues, selectedValue) ;

View

<%=Html.DropDownList("DealerTypes", ViewData["DealerTypes"] as SelectList)%>

Changed by the following:

View

<%=Html.DropDownList("DealerTypesDD", ViewData["DealerTypes"] as SelectList)%>

It appears that the DropDown must not have the same name has the ViewData name :S weird but it worked.

Why is my element value not getting changed? Am I using the wrong function?

As the plural in getElementsByName() implies, does it always return list of elements that have this name. So when you have an input element with that name:

<input type="text" name="Tue">

And it is the first one with that name, you have to use document.getElementsByName('Tue')[0] to get the first element of the list of elements with this name.

Beside that are properties case sensitive and the correct spelling of the value property is .value.

Mercurial: how to amend the last commit?

Recent versions of Mercurial include the evolve extension which provides the hg amend command. This allows amending a commit without losing the pre-amend history in your version control.

hg amend [OPTION]... [FILE]...

aliases: refresh

combine a changeset with updates and replace it with a new one

Commits a new changeset incorporating both the changes to the given files
and all the changes from the current parent changeset into the repository.

See 'hg commit' for details about committing changes.

If you don't specify -m, the parent's message will be reused.

Behind the scenes, Mercurial first commits the update as a regular child
of the current parent. Then it creates a new commit on the parent's
parents with the updated contents. Then it changes the working copy parent
to this new combined changeset. Finally, the old changeset and its update
are hidden from 'hg log' (unless you use --hidden with log).

See https://www.mercurial-scm.org/doc/evolution/user-guide.html#example-3-amend-a-changeset-with-evolve for a complete description of the evolve extension.

How can I close a browser window without receiving the "Do you want to close this window" prompt?

My friend... there is a way but "hack" does not begin to describe it. You have to basically exploit a bug in IE 6 & 7.

Works every time!

Instead of calling window.close(), redirect to another page.

Opening Page:

alert("No whammies!");
window.open("closer.htm", '_self');

Redirect to another page. This fools IE into letting you close the browser on this page.

Closing Page:

<script type="text/javascript">
    window.close();
</script>

Awesome huh?!

ASP.NET Identity DbContext confusion

This is a late entry for folks, but below is my implementation. You will also notice I stubbed-out the ability to change the the KEYs default type: the details about which can be found in the following articles:

NOTES:
It should be noted that you cannot use Guid's for your keys. This is because under the hood they are a Struct, and as such, have no unboxing which would allow their conversion from a generic <TKey> parameter.

THE CLASSES LOOK LIKE:

public class ApplicationDbContext : IdentityDbContext<ApplicationUser, CustomRole, string, CustomUserLogin, CustomUserRole, CustomUserClaim>
{
    #region <Constructors>

    public ApplicationDbContext() : base(Settings.ConnectionString.Database.AdministrativeAccess)
    {
    }

    #endregion

    #region <Properties>

    //public DbSet<Case> Case { get; set; }

    #endregion

    #region <Methods>

    #region

    protected override void OnModelCreating(DbModelBuilder modelBuilder)
    {
        base.OnModelCreating(modelBuilder);

        //modelBuilder.Configurations.Add(new ResourceConfiguration());
        //modelBuilder.Configurations.Add(new OperationsToRolesConfiguration());
    }

    #endregion

    #region

    public static ApplicationDbContext Create()
    {
        return new ApplicationDbContext();
    }

    #endregion

    #endregion
}

    public class ApplicationUser : IdentityUser<string, CustomUserLogin, CustomUserRole, CustomUserClaim>
    {
        #region <Constructors>

        public ApplicationUser()
        {
            Init();
        }

        #endregion

        #region <Properties>

        [Required]
        [StringLength(250)]
        public string FirstName { get; set; }

        [Required]
        [StringLength(250)]
        public string LastName { get; set; }

        #endregion

        #region <Methods>

        #region private

        private void Init()
        {
            Id = Guid.Empty.ToString();
        }

        #endregion

        #region public

        public async Task<ClaimsIdentity> GenerateUserIdentityAsync(UserManager<ApplicationUser, string> manager)
        {
            // Note the authenticationType must match the one defined in CookieAuthenticationOptions.AuthenticationType
            var userIdentity = await manager.CreateIdentityAsync(this, DefaultAuthenticationTypes.ApplicationCookie);

            // Add custom user claims here

            return userIdentity;
        }

        #endregion

        #endregion
    }

    public class CustomUserStore : UserStore<ApplicationUser, CustomRole, string, CustomUserLogin, CustomUserRole, CustomUserClaim>
    {
        #region <Constructors>

        public CustomUserStore(ApplicationDbContext context) : base(context)
        {
        }

        #endregion
    }

    public class CustomUserRole : IdentityUserRole<string>
    {
    }

    public class CustomUserLogin : IdentityUserLogin<string>
    {
    }

    public class CustomUserClaim : IdentityUserClaim<string> 
    { 
    }

    public class CustomRoleStore : RoleStore<CustomRole, string, CustomUserRole>
    {
        #region <Constructors>

        public CustomRoleStore(ApplicationDbContext context) : base(context)
        {
        } 

        #endregion
    }

    public class CustomRole : IdentityRole<string, CustomUserRole>
    {
        #region <Constructors>

        public CustomRole() { }
        public CustomRole(string name) 
        { 
            Name = name; 
        }

        #endregion
    }

How to read pdf file and write it to outputStream

You can use PdfBox from Apache which is simple to use and has good performance.

Here is an example of extracting text from a PDF file (you can read more here) :

import java.io.*;
import org.apache.pdfbox.pdmodel.*;
import org.apache.pdfbox.util.*;

public class PDFTest {

 public static void main(String[] args){
 PDDocument pd;
 BufferedWriter wr;
 try {
         File input = new File("C:\\Invoice.pdf");  // The PDF file from where you would like to extract
         File output = new File("C:\\SampleText.txt"); // The text file where you are going to store the extracted data
         pd = PDDocument.load(input);
         System.out.println(pd.getNumberOfPages());
         System.out.println(pd.isEncrypted());
         pd.save("CopyOfInvoice.pdf"); // Creates a copy called "CopyOfInvoice.pdf"
         PDFTextStripper stripper = new PDFTextStripper();
         wr = new BufferedWriter(new OutputStreamWriter(new FileOutputStream(output)));
         stripper.writeText(pd, wr);
         if (pd != null) {
             pd.close();
         }
        // I use close() to flush the stream.
        wr.close();
 } catch (Exception e){
         e.printStackTrace();
        } 
     }
}

UPDATE:

You can get the text using PDFTextStripper:

PDFTextStripper reader = new PDFTextStripper();
String pageText = reader.getText(pd); // PDDocument object created

SQL conditional SELECT

The noob way to do this:

SELECT field1, field2 FROM table WHERE field1 = TRUE OR field2 = TRUE

You can manage this information properly at the programming language only doing an if-else.

Example in ASP/JavaScript

// Code to retrieve the ADODB.Recordset
if (rs("field1")) {
   do_the_stuff_a();
}
if (rs("field2")) {
   do_the_stuff_b();
}
rs.MoveNext();

Marquee text in Android

TextView textView = (TextView) this.findViewById(R.id.textview_marquee);  
textView.setEllipsize(TruncateAt.MARQUEE);
textView.setText("General Information... general information... General Information");
textView.setSelected(true);
textView.setSingleLine(true);

Detect IF hovering over element with jQuery

Use:

var hovered = $("#parent").find("#element:hover").length;

jQuery 1.9+

Best way to generate a random float in C#

One more version... (I think this one is pretty good)

static float NextFloat(Random random)
{
    (float)(float.MaxValue * 2.0 * (rand.NextDouble()-0.5));
}

//inline version
float myVal = (float)(float.MaxValue * 2.0 * (rand.NextDouble()-0.5));

I think this...

  • is the 2nd fastest (see benchmarks)
  • is evenly distributed

And One more version...(not as good but posting anyway)

static float NextFloat(Random random)
{
    return float.MaxValue * ((rand.Next() / 1073741824.0f) - 1.0f);
}

//inline version
float myVal = (float.MaxValue * ((rand.Next() / 1073741824.0f) - 1.0f));

I think this...

  • is the fastest (see benchmarks)
  • is evenly distributed however because Next() is a 31 bit random value it will only return 2^31 values. (50% of the neighbor values will have the same value)

Testing of most of the functions on this page: (i7, release, without debug, 2^28 loops)

 Sunsetquest1: min: 3.402823E+38  max: -3.402823E+38 time: 3096ms
 SimonMourier: min: 3.402823E+38  max: -3.402819E+38 time: 14473ms
 AnthonyPegram:min: 3.402823E+38  max: -3.402823E+38 time: 3191ms
 JonSkeet:     min: 3.402823E+38  max: -3.402823E+38 time: 3186ms
 Sixlettervar: min: 1.701405E+38  max: -1.701410E+38 time: 19653ms
 Sunsetquest2: min: 3.402823E+38  max: -3.402823E+38 time: 2930ms

What is the proof of of (N–1) + (N–2) + (N–3) + ... + 1= N*(N–1)/2

Assume n=2. Then we have 2-1 = 1 on the left side and 2*1/2 = 1 on the right side.

Denote f(n) = (n-1)+(n-2)+(n-3)+...+1

Now assume we have tested up to n=k. Then we have to test for n=k+1.

on the left side we have k+(k-1)+(k-2)+...+1, so it's f(k)+k

On the right side we then have (k+1)*k/2 = (k^2+k)/2 = (k^2 +2k - k)/2 = k+(k-1)k/2 = kf(k)

So this have to hold for every k, and this concludes the proof.

jQuery check if it is clicked or not

<script>
    var listh = document.getElementById( 'list-home-list' );
    var hb = document.getElementsByTagName('hb');
    $("#list-home-list").click(function(){
    $(this).style.color = '#2C2E33';
    hb.style.color = 'white';
    });
</script>

How to enable ASP classic in IIS7.5

Add Authenticated Users

Make the file accessible to the Authenticated Users group. Right click your virtual directory and give the group read/write access to Authenticated Users.

I faced issue on windows 10 machine.

..The underlying connection was closed: An unexpected error occurred on a receive

To expand on Bartho Bernsmann's answer, I should like to add that one can have a universal, future-proof implementation at the expense of a little reflection:

static void AllowAllSecurityPrototols()
{   int                  i, n;
    Array                types;
    SecurityProtocolType combined;

    types = Enum.GetValues( typeof( SecurityProtocolType ) ); 
    combined = ( SecurityProtocolType )types.GetValue( 0 );

    n = types.Length;
    for( i = 1; i < n; i += 1 )
    {   combined |= ( SecurityProtocolType )types.GetValue( i );  }

    ServicePointManager.SecurityProtocol = combined;
}

I invoke this method in the static constructor of the class that accesses the internet.

'mvn' is not recognized as an internal or external command,

Add maven directory /bin to System variables under the name Path.

To check this, you can echo %PATH%

Django Multiple Choice Field / Checkbox Select Multiple

The models.CharField is a CharField representation of one of the choices. What you want is a set of choices. This doesn't seem to be implemented in django (yet).

You could use a many to many field for it, but that has the disadvantage that the choices have to be put in a database. If you want to use hard coded choices, this is probably not what you want.

There is a django snippet at http://djangosnippets.org/snippets/1200/ that does seem to solve your problem, by implementing a ModelField MultipleChoiceField.

How do I print bytes as hexadecimal?

This is a modified version of the Nibble to Hex method

void hexArrayToStr(unsigned char* info, unsigned int infoLength, char **buffer) {
    const char* pszNibbleToHex = {"0123456789ABCDEF"};
    int nNibble, i;
    if (infoLength > 0) {
        if (info != NULL) {
            *buffer = (char *) malloc((infoLength * 2) + 1);
            buffer[0][(infoLength * 2)] = 0;
            for (i = 0; i < infoLength; i++) {
                nNibble = info[i] >> 4;
                buffer[0][2 * i] = pszNibbleToHex[nNibble];
                nNibble = info[i] & 0x0F;
                buffer[0][2 * i + 1] = pszNibbleToHex[nNibble];
            }
        } else {
            *buffer = NULL;
        }
    } else {
        *buffer = NULL;
    }
}

Java: Sending Multiple Parameters to Method

Suppose you have void method that prints many objects;

public static void print( Object... values){
   for(Object c : values){
      System.out.println(c);
   }
}

Above example I used vararge as an argument that accepts values from 0 to N.

From comments: What if 2 strings and 5 integers ??

Answer:

print("string1","string2",1,2,3,4,5);

<> And Not In VB.NET

The C# and VB.NET compilers often generate different IL for operations that are apparently equivalent in both languages. It just so happens that C# does the "expected" thing when you write stringvar == null, but VB.NET does not. To get the same effect in VB.NET you have to force true reference equality with the Is operator.

Limit file format when using <input type="file">?

Use input tag with accept attribute

<input type="file" name="my-image" id="image" accept="image/gif, image/jpeg, image/png" />

Click here for the latest browser compatibility table

Live demo here

To select only image files, you can use this accept="image/*"

<input type="file" name="my-image" id="image" accept="image/*" />

Live demo here

Only gif, jpg and png will be shown, screen grab from Chrome version 44 Only gif, jpg and png will be shown, screen grab from Chrome version 44

How does the Java 'for each' loop work?

It would look something like this. Very crufty.

for (Iterator<String> i = someList.iterator(); i.hasNext(); )
        System.out.println(i.next());

There is a good writeup on for each in the Sun documentation.

What is makeinfo, and how do I get it?

In (at least) Ubuntu when using bash, it tells you what package you need to install if you type in a command and its not found in your path. My terminal says you need to install 'texinfo' package.

sudo apt-get install texinfo

How to resize an Image C#

public string CreateThumbnail(int maxWidth, int maxHeight, string path)
{

    var image = System.Drawing.Image.FromFile(path);
    var ratioX = (double)maxWidth / image.Width;
    var ratioY = (double)maxHeight / image.Height;
    var ratio = Math.Min(ratioX, ratioY);
    var newWidth = (int)(image.Width * ratio);
    var newHeight = (int)(image.Height * ratio);
    var newImage = new Bitmap(newWidth, newHeight);
    Graphics thumbGraph = Graphics.FromImage(newImage);

    thumbGraph.CompositingQuality = CompositingQuality.HighQuality;
    thumbGraph.SmoothingMode = SmoothingMode.HighQuality;
    //thumbGraph.InterpolationMode = InterpolationMode.HighQualityBicubic;

    thumbGraph.DrawImage(image, 0, 0, newWidth, newHeight);
    image.Dispose();

    string fileRelativePath = "newsizeimages/" + maxWidth + Path.GetFileName(path);
    newImage.Save(Server.MapPath(fileRelativePath), newImage.RawFormat);
    return fileRelativePath;
}

Click here http://bhupendrasinghsaini.blogspot.in/2014/07/resize-image-in-c.html

What's the difference between align-content and align-items?

align-content

align-content controls the cross-axis (i.e. vertical direction if the flex-direction is row, and horizontal if the flex-direction is column) positioning of multiple lines relative to each other.

(Think lines of a paragraph being vertically spread out, stacked toward the top, stacked toward the bottom. This is under a flex-direction row paradigm).

align-items

align-items controls the cross-axis of an individual line of flex elements.

(Think how an individual line of a paragraph is aligned, if it contains some normal text and some taller text like math equations. In that case, will it be the bottom, top, or center of each type of text in a line that will be aligned?)

Java - Convert image to Base64

The line

base64String = Base64.encode(byteArray);

converts the full array (102400 bytes) to Base64, not just the number of bytes you have read. You need to pass it the numbers of bytes.

How to get just the date part of getdate()?

Try this:

SELECT CONVERT(date, GETDATE())

Running .sh scripts in Git Bash

If by any chance you've changed the default open for .sh files to a text editor like I had, you can just "bash .\yourscript.sh", provided you have git bash installed and in path.

Delete all files in directory (but not directory) - one liner solution

I think this will work (based on NonlinearFruit previous answer):

Files.walk(Paths.get("C:/test/ABC/"))
                .sorted(Comparator.reverseOrder())
                .map(Path::toFile)
                .filter(item -> !item.getPath().equals("C:/test/ABC/"))
                .forEach(File::delete);

Cheers!

When to use virtual destructors?

Declare destructors virtual in polymorphic base classes. This is Item 7 in Scott Meyers' Effective C++. Meyers goes on to summarize that if a class has any virtual function, it should have a virtual destructor, and that classes not designed to be base classes or not designed to be used polymorphically should not declare virtual destructors.

Converting a JToken (or string) to a given Type

There is a ToObject method now.

var obj = jsonObject["date_joined"];
var result = obj.ToObject<DateTime>();

It also works with any complex type, and obey to JsonPropertyAttribute rules

var result = obj.ToObject<MyClass>();

public class MyClass 
{ 
    [JsonProperty("date_field")]
    public DateTime MyDate {get;set;}
}

How to make child element higher z-index than parent?

Nothing is impossible. Use the force.

.parent {
    position: relative;
}

.child {
    position: absolute;
    top:0;
    left: 0;
    right: 0;
    bottom: 0;
    z-index: 100;
}

Oracle query execution time

I'd recommend looking at consistent gets/logical reads as a better proxy for 'work' than run time. The run time can be skewed by what else is happening on the database server, how much stuff is in the cache etc.

But if you REALLY want SQL executing time, the V$SQL view has both CPU_TIME and ELAPSED_TIME.

How do you convert a jQuery object into a string?

No need to clone and add to the DOM to use .html(), you can do:

$('#item-of-interest').wrap('<div></div>').html()

Get escaped URL parameter

You should not use jQuery for something like this!
The modern way is to use small reusable modules through a package-manager like Bower.

I've created a tiny module that can parse the query string into an object. Use it like this:

// parse the query string into an object and get the property
queryString.parse(unescape(location.search)).search;
//=> æøå