Programs & Examples On #Rendering engine

What is WebKit and how is it related to CSS?

A good documentation about WebEngines especially webKit and its developers you can read at: WebKit

How to have conditional elements and keep DRY with Facebook React's JSX?

Just to extend @Jack Allan answer with references to docs.

React basic (Quick Start) documentation suggests null in such case. However, Booleans, Null, and Undefined Are Ignored as well, mentioned in Advanced guide.

How to replace NaNs by preceding values in pandas DataFrame?

ffill now has it's own method pd.DataFrame.ffill

df.ffill()

     0    1    2
0  1.0  2.0  3.0
1  4.0  2.0  3.0
2  4.0  2.0  9.0

How to make a HTTP request using Ruby on Rails?

OpenURI is the best; it's as simple as

require 'open-uri'
response = open('http://example.com').read

How to redirect 404 errors to a page in ExpressJS?

I used the handler below to handle 404 error with a static .ejs file.

Put this code in a route script and then require that file.js through app.use() in your app.js/server.js/www.js (if using IntelliJ for NodeJS)

You can also use a static .html file.

//Unknown route handler
 router.get("[otherRoute]", function(request, response) {
     response.status(404);
     response.render("error404.[ejs]/[html]");
     response.end();
 });

This way, the running express server will response with a proper 404 error and your website can also include a page that properly displays the server's 404 response properly. You can also include a navbar in that 404 error template that links to other important content of your website.

Find a class somewhere inside dozens of JAR files?

There are also two different utilities called both "JarScan" that do exactly what you are asking for: JarScan (inetfeedback.com) and JarScan (java.net)

Start new Activity and finish current one in Android?

Use finish like this:

Intent i = new Intent(Main_Menu.this, NextActivity.class);
finish();  //Kill the activity from which you will go to next activity 
startActivity(i);

FLAG_ACTIVITY_NO_HISTORY you can use in case for the activity you want to finish. For exampe you are going from A-->B--C. You want to finish activity B when you go from B-->C so when you go from A-->B you can use this flag. When you go to some other activity this activity will be automatically finished.

To learn more on using Intent.FLAG_ACTIVITY_NO_HISTORY read: http://developer.android.com/reference/android/content/Intent.html#FLAG_ACTIVITY_NO_HISTORY

Pull request vs Merge request

As mentioned in previous answers, both serve almost same purpose. Personally I like git rebase and merge request (as in gitlab). It takes burden off of the reviewer/maintainer, making sure that while adding merge request, the feature branch includes all of the latest commits done on main branch after feature branch is created. Here is a very useful article explaining rebase in detail: https://git-scm.com/book/en/v2/Git-Branching-Rebasing

Difference between Fact table and Dimension table?

In Data Warehouse Modeling, a star schema and a snowflake schema consists of Fact and Dimension tables.

Fact Table:

  • It contains all the primary keys of the dimension and associated facts or measures(is a property on which calculations can be made) like quantity sold, amount sold and average sales.

Dimension Tables:

  • Dimension tables provides descriptive information for all the measurements recorded in fact table.
  • Dimensions are relatively very small as comparison of fact table.
  • Commonly used dimensions are people, products, place and time.

enter image description here

image source

How to make JQuery-AJAX request synchronous

It's as simple as the one below, and works like a charm.

My solution perfectly answers your question: How to make JQuery-AJAX request synchronous

Set ajax to synchronous before the ajax call, and then reset it after your ajax call:

$.ajaxSetup({async: false});

$ajax({ajax call....});

$.ajaxSetup({async: true});

In your case it would look like this:

$.ajaxSetup({async: false});

$.ajax({
        type: "POST",
        async: "false",
        url: "checkpass.php",
        data: "password="+password,
        success: function(html) {
            var arr=$.parseJSON(html);
            if(arr == "Successful") {
                return true;
            } else {
                return false;
            }
        }
    });


$.ajaxSetup({async: true});

I hope it helps :)

Setting PHPMyAdmin Language

sounds like you downloaded the german xampp package instead of the english xampp package (yes, it's another download-link) where the language is set according to the package you loaded. to change the language afterwards, simply edit the config.inc.php and set:

$cfg['Lang'] = 'en-utf-8';

How to execute shell command in Javascript

With NodeJS is simple like that! And if you want to run this script at each boot of your server, you can have a look on the forever-service application!

var exec = require('child_process').exec;

exec('php main.php', function (error, stdOut, stdErr) {
    // do what you want!
});

Visual Studio Code: How to show line endings

There's an extension that shows line endings. You can configure the color used, the characters that represent CRLF and LF and a boolean that turns it on and off.

Name: Line endings 
Id: jhartell.vscode-line-endings 
Description: Display line ending characters in vscode 
Version: 0.1.0 
Publisher: Johnny Härtell 

VS Marketplace Link

How to SELECT based on value of another SELECT

SELECT x.name, x.summary, (x.summary / COUNT(*)) as percents_of_total
FROM tbl t
INNER JOIN 
(SELECT name, SUM(value) as summary
FROM tbl
WHERE year BETWEEN 2000 AND 2001
GROUP BY name) x ON x.name = t.name
GROUP BY x.name, x.summary

Access parent DataContext from DataTemplate

I was searching how to do something similar in WPF and I got this solution:

<ItemsControl ItemsSource="{Binding MyItems,Mode=OneWay}">
<ItemsControl.ItemsPanel>
    <ItemsPanelTemplate>
        <StackPanel Orientation="Vertical" />
    </ItemsPanelTemplate>
</ItemsControl.ItemsPanel>
<ItemsControl.ItemTemplate>
    <DataTemplate>
        <RadioButton 
            Content="{Binding}" 
            Command="{Binding Path=DataContext.CustomCommand, 
                        RelativeSource={RelativeSource Mode=FindAncestor,      
                        AncestorType={x:Type ItemsControl}} }"
            CommandParameter="{Binding}" />
    </DataTemplate>
</ItemsControl.ItemTemplate>

I hope this works for somebody else. I have a data context which is set automatically to the ItemsControls, and this data context has two properties: MyItems -which is a collection-, and one command 'CustomCommand'. Because of the ItemTemplate is using a DataTemplate, the DataContext of upper levels is not directly accessible. Then the workaround to get the DC of the parent is use a relative path and filter by ItemsControl type.

How to use pip with python 3.4 on windows?

I know this is a very old topic, but in case someone needs it

there is no pip in python 3.4, so we have to use python -m ensurepip to install pip

If statements for Checkboxes

I'm making an assumption that you mean not checked. I don't have a C# compiler handy but:

if (checkbox1.Checked && !checkbox2.Checked)
{

}
else if (!checkbox1.Checked && checkbox2.Checked)
{

}

Capturing browser logs with Selenium WebDriver using Java

Starting with Firefox 65 an about:config flag exists now so console API calls like console.log() land in the output stream and thus the log file (see (https://github.com/mozilla/geckodriver/issues/284#issuecomment-458305621).

profile = new FirefoxProfile();
profile.setPreference("devtools.console.stdout.content", true);

python pandas convert index to datetime

I just give other option for this question - you need to use '.dt' in your code:

_x000D_
_x000D_
import pandas as pd_x000D_
_x000D_
df.index = pd.to_datetime(df.index)_x000D_
_x000D_
#for get year_x000D_
df.index.dt.year_x000D_
_x000D_
#for get month_x000D_
df.index.dt.month_x000D_
_x000D_
#for get day_x000D_
df.index.dt.day_x000D_
_x000D_
#for get hour_x000D_
df.index.dt.hour_x000D_
_x000D_
#for get minute_x000D_
df.index.dt.minute
_x000D_
_x000D_
_x000D_

Best Python IDE on Linux

I haven't played around with it much but eclipse/pydev feels nice.

Java: How to Indent XML Generated by Transformer

The following code is working for me with Java 7. I set the indent (yes) and indent-amount (2) on the transformer (not the transformer factory) to get it working.

TransformerFactory tf = TransformerFactory.newInstance();
Transformer t = tf.newTransformer();
t.setOutputProperty("{http://xml.apache.org/xslt}indent-amount", "2");
t.setOutputProperty(OutputKeys.INDENT, "yes");
t.transform(source, result);

@mabac's solution to set the attribute didn't work for me, but @lapo's comment proved helpful.

Custom date format with jQuery validation plugin

Is Easy, Example: Valid for HTML5 automatic type="date".

<script type="text/javascript" src="//ajax.aspnetcdn.com/ajax/jquery.validate/1.14.0/jquery.validate.min.js"></script>
<script type="text/javascript" src="//ajax.aspnetcdn.com/ajax/jquery.validate/1.14.0/additional-methods.min.js"></script>
<script type="text/javascript" src="//ajax.aspnetcdn.com/ajax/jquery.validate/1.14.0/localization/messages_es.js"></script>

$(function () {

        // Overload method default "date" jquery.validate.min.js
        $.validator.addMethod(
            "date",
            function(value, element) {
                var dateReg = /^\d{2}([./-])\d{2}\1\d{4}$/;
                return value.match(dateReg);
            },
            "Invalid date"
        );

     // Form Demo jquery.validate.min.js
     $('#form-datos').validate({
        submitHandler: function(form) {
            form.submit();
        }
    });

});

How to create a numpy array of all True or all False?

ones and zeros, which create arrays full of ones and zeros respectively, take an optional dtype parameter:

>>> numpy.ones((2, 2), dtype=bool)
array([[ True,  True],
       [ True,  True]], dtype=bool)
>>> numpy.zeros((2, 2), dtype=bool)
array([[False, False],
       [False, False]], dtype=bool)

Time calculation in php (add 10 hours)?

You can simply make use of the DateTime class , OOP Style.

<?php
$date = new DateTime('1:00:00');
$date->add(new DateInterval('PT10H'));
echo $date->format('H:i:s a'); //"prints" 11:00:00 a.m

regular expression for anything but an empty string

I think [ ]{4} might work in the example where you need to detect 4 spaces. Same with the rest: [ ]{1}, [ ]{2} and [ ]{3}. If you want to detect an empty string in general, ^[ ]*$ will do.

Android fade in and fade out with ImageView

The best and the easiest way, for me was this..

->Simply create a thread with Handler containing sleep().

private ImageView myImageView;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_shape_count); myImageView= (ImageView)findViewById(R.id.shape1);
    Animation myFadeInAnimation = AnimationUtils.loadAnimation(this, R.anim.fadein);
    myImageView.startAnimation(myFadeInAnimation);

    new Thread(new Runnable() {
        private Handler handler = new Handler(){
            @Override
            public void handleMessage(Message msg) {
                Log.w("hendler", "recived");
                    Animation myFadeOutAnimation = AnimationUtils.loadAnimation(getBaseContext(), R.anim.fadeout);
                    myImageView.startAnimation(myFadeOutAnimation);
                    myImageView.setVisibility(View.INVISIBLE);
            }
        };

        @Override
        public void run() {
            try{
                Thread.sleep(2000); // your fadein duration
            }catch (Exception e){
            }
            handler.sendEmptyMessage(1);

        }
    }).start();
}

Convert datetime to Unix timestamp and convert it back in python

If you want to convert a python datetime to seconds since epoch you should do it explicitly:

>>> import datetime
>>> datetime.datetime(2012, 04, 01, 0, 0).strftime('%s')
'1333234800'
>>> (datetime.datetime(2012, 04, 01, 0, 0) - datetime.datetime(1970, 1, 1)).total_seconds()
1333238400.0

In Python 3.3+ you can use timestamp() instead:

>>> import datetime
>>> datetime.datetime(2012, 4, 1, 0, 0).timestamp()
1333234800.0

How to Sign an Already Compiled Apk

create a key using

keytool -genkey -v -keystore my-release-key.keystore -alias alias_name -keyalg RSA -keysize 2048 -validity 10000

then sign the apk using :

jarsigner -verbose -sigalg SHA1withRSA -digestalg SHA1 -keystore my-release-key.keystore my_application.apk alias_name

check here for more info

ng-if, not equal to?

Here is a nifty solution with a filter:

app.filter('status', function() {

  var statusDict = {
    0: "No payment",
    1: "Late",
    2: "Late",
    3: "Some payment made",
    4: "Some payment made",
    5: "Some payment made",
    6: "Late and further taken out"
  };

  return function(status) {
    return statusDict[status] || 'Error';
  };
});

Markup:

<div ng-repeat="details in myDataSet">
  <p>{{ details.Name }}</p>
  <p>{{ details.DOB  }}</p>
  <p>{{ details.Payment[0].Status | status }}</p>
  <p>{{ details.Gender}}</p>
</div>

Is it possible to capture the stdout from the sh DSL command in the pipeline

Note: The linked Jenkins issue has since been solved.

As mention in JENKINS-26133 it was not possible to get shell output as a variable. As a workaround suggested using of writ-read from temporary file. So, your example would have looked like:

sh "echo foo > result";
def output=readFile('result').trim()
echo "output=$output";

Can I set text box to readonly when using Html.TextBoxFor?

   @Html.TextBoxFor(model => model.IdUsuario, new { @Value = "" + User.Identity.GetUserId() + "", @disabled = "true" })

@disabled = "true"

Work very well

Read the package name of an Android APK

Based on @hackbod answer ... but related to windows.

aapt command is located on Android\SDK\build-tools\version. If you need more info about what is appt command (Android Asset Packaging Tool) read this https://stackoverflow.com/a/28234956/812915

The dump sub-command of aapt is used to display the values of individual elements or parts of a package:

aapt dump badging <path-to-apk>

If you want see only the line with package: name info, use findstr

aapt dump badging <path-to-apk> | findstr -n "package: name" | findstr "1:"

Hope it help other windows user!

SQL Server String or binary data would be truncated

You will need to post the table definitions for the source and destination tables for us to figure out where the issue is but the bottom line is that one of your columns in the source table is bigger than your destination columns. It could be that you are changing formats in a way you were not aware of. The database model you are moving from is important in figuring that out as well.

Getting Image from URL (Java)

Directly calling a URL to get an image may concern with major security issues. You need to ensure that you have sufficient rights to access that resource. However You can use ByteOutputStream to read image file. This is an example (Its just an example, you need to do necessary changes as per your requirement.)

ByteArrayOutputStream bis = new ByteArrayOutputStream();
InputStream is = null;
try {
  is = url.openStream ();
  byte[] bytebuff = new byte[4096]; 
  int n;

  while ( (n = is.read(bytebuff)) > 0 ) {
    bis.write(bytebuff, 0, n);
  }
}

Comments in .gitignore?

Yes, you may put comments in there. They however must start at the beginning of a line.

cf. http://git-scm.com/book/en/Git-Basics-Recording-Changes-to-the-Repository#Ignoring-Files

The rules for the patterns you can put in the .gitignore file are as follows:
- Blank lines or lines starting with # are ignored.
[…]

The comment character is #, example:

# no .a files
*.a

What is the use of WPFFontCache Service in WPF? WPFFontCache_v0400.exe taking 100 % CPU all the time this exe is running, why?

Use This its is very useful for your solution:

  1. Start > Control Panel > Administrative Tools > Services
  2. Scroll down to 'Windows Presentation Foundation Font Cache 4.0.0.0' and then right click and select properties
  3. In the window then select 'disabled' in the startup type combo

How can I make a JUnit test wait?

In case your static code analyzer (like SonarQube) complaints, but you can not think of another way, rather than sleep, you may try with a hack like: Awaitility.await().pollDelay(Durations.ONE_SECOND).until(() -> true); It's conceptually incorrect, but it is the same as Thread.sleep(1000).

The best way, of course, is to pass a Callable, with your appropriate condition, rather than true, which I have.

https://github.com/awaitility/awaitility

error_log per Virtual Host?

To set the Apache (not the PHP) log, the easiest way to do this would be to do:

<VirtualHost IP:Port>
   # Stuff,
   # More Stuff,
   ErrorLog /path/where/you/want/the/error.log
</VirtualHost>

If there is no leading "/" it is assumed to be relative.

Apache Error Log Page

What's the valid way to include an image with no src?

As written in comments, this method is wrong.

I didn't find this answer before, but acording to W3 Specs valid empty src tag would be an anchor link #.

Example: src="#", src="#empty"

Page validates successfully and no extra request are made.

Last Key in Python Dictionary

yes there is : len(data)-1.

For the first element it´s : 0

Why doesn't Dijkstra's algorithm work for negative weight edges?

Correctness of Dijkstra's algorithm:

We have 2 sets of vertices at any step of the algorithm. Set A consists of the vertices to which we have computed the shortest paths. Set B consists of the remaining vertices.

Inductive Hypothesis: At each step we will assume that all previous iterations are correct.

Inductive Step: When we add a vertex V to the set A and set the distance to be dist[V], we must prove that this distance is optimal. If this is not optimal then there must be some other path to the vertex V that is of shorter length.

Suppose this some other path goes through some vertex X.

Now, since dist[V] <= dist[X] , therefore any other path to V will be atleast dist[V] length, unless the graph has negative edge lengths.

Thus for dijkstra's algorithm to work, the edge weights must be non negative.

Flutter Circle Design

You can use CustomMultiChildLayout to draw this kind of layouts. Here you can find a tutorial: How to Create Custom Layout Widgets in Flutter.

Vue Js - Loop via v-for X times (in a range)

In 2.2.0+, when using v-for with a component, a key is now required.

<div v-for="item in items" :key="item.id">

Source

How many values can be represented with n bits?

There's an easier way to think about this. Start with 1 bit. This can obviously represent 2 values (0 or 1). What happens when we add a bit? We can now represent twice as many values: the values we could represent before with a 0 appended and the values we could represent before with a 1 appended.

So the the number of values we can represent with n bits is just 2^n (2 to the power n)

Add image in pdf using jspdf

maybe a little bit late, but I come to this situation recently and found a simple solution, 2 functions are needed.

  1. load the image.

    function getImgFromUrl(logo_url, callback) {
        var img = new Image();
        img.src = logo_url;
        img.onload = function () {
            callback(img);
        };
    } 
    
  2. in onload event on first step, make a callback to use the jspdf doc.

    function generatePDF(img){
        var options = {orientation: 'p', unit: 'mm', format: custom};
        var doc = new jsPDF(options);
        doc.addImage(img, 'JPEG', 0, 0, 100, 50);}
    
  3. use the above functions.

    var logo_url = "/images/logo.jpg";
    getImgFromUrl(logo_url, function (img) {
        generatePDF(img);
    });
    

Reading *.wav files in Python

Using the struct module, you can take the wave frames (which are in 2's complementary binary between -32768 and 32767 (i.e. 0x8000 and 0x7FFF). This reads a MONO, 16-BIT, WAVE file. I found this webpage quite useful in formulating this:

import wave, struct

wavefile = wave.open('sine.wav', 'r')

length = wavefile.getnframes()
for i in range(0, length):
    wavedata = wavefile.readframes(1)
    data = struct.unpack("<h", wavedata)
    print(int(data[0]))

This snippet reads 1 frame. To read more than one frame (e.g., 13), use

wavedata = wavefile.readframes(13)
data = struct.unpack("<13h", wavedata)

How to import an Excel file into SQL Server?

There are many articles about writing code to import an excel file, but this is a manual/shortcut version:

If you don't need to import your Excel file programmatically using code you can do it very quickly using the menu in SQL Management Studio.

The quickest way to get your Excel file into SQL is by using the import wizard:

  1. Open SSMS (Sql Server Management Studio) and connect to the database where you want to import your file into.
  2. Import Data: in SSMS in Object Explorer under 'Databases' right-click the destination database, select Tasks, Import Data. An import wizard will pop up (you can usually just click 'Next' on the first screen).

enter image description here

  1. The next window is 'Choose a Data Source', select Excel:

    • In the 'Data Source' dropdown list select Microsoft Excel (this option should appear automatically if you have excel installed).

    • Click the 'Browse' button to select the path to the Excel file you want to import.

    • Select the version of the excel file (97-2003 is usually fine for files with a .XLS extension, or use 2007 for newer files with a .XLSX extension)
    • Tick the 'First Row has headers' checkbox if your excel file contains headers.
    • Click next.

enter image description here

  1. On the 'Choose a Destination' screen, select destination database:
    • Select the 'Server name', Authentication (typically your sql username & password) and select a Database as destination. Click Next.

enter image description here

  1. On the 'Specify Table Copy or Query' window:

    • For simplicity just select 'Copy data from one or more tables or views', click Next.
  2. 'Select Source Tables:' choose the worksheet(s) from your Excel file and specify a destination table for each worksheet. If you don't have a table yet the wizard will very kindly create a new table that matches all the columns from your spreadsheet. Click Next.

enter image description here

  1. Click Finish.

Darken background image on hover

try this

http://jsfiddle.net/qrmqM/6/

CSS

.image {
    background: url('http://cdn1.iconfinder.com/data/icons/round-simple-social-icons/58/facebook.png');
    width: 58px;
    height: 58px;
      opacity:0.4;
filter:alpha(opacity=40); /* For IE8 and earlier */
}
.image:hover{
    background: url('http://cdn1.iconfinder.com/data/icons/round-simple-social-icons/58/facebook.png');
    width: 58px;
    height: 58px;

    border-radius:100px;
  opacity:1;
            filter:alpha(opacity=100);

}

HTML

<div class="image"></div>

What exactly does numpy.exp() do?

exp(x) = e^x where e= 2.718281(approx)

import numpy as np

ar=np.array([1,2,3])
ar=np.exp(ar)
print ar

outputs:

[ 2.71828183  7.3890561  20.08553692]

Terminal Multiplexer for Microsoft Windows - Installers for GNU Screen or tmux

One of alternatives is MSYS2 , in another words "MinGW-w64"/Git Bash. You can simply ssh to Unix machines and run most of linux commands from it. Also install tmux!

To install tmux in MSYS2:

run command pacman -S tmux

To run tmux on Git Bash:

install MSYS2 and copy tmux.exe and msys-event-2-1-6.dll from MSYS2 folder C:\msys64\usr\bin to your Git Bash directory C:\Program Files\Git\usr\bin.

Add tooltip to font awesome icon

In regards to this question, this can be easily achieved using a few lines of SASS;

HTML:

<a href="https://www.urbandictionary.com/define.php?term=techninja" data-tool-tip="What's a tech ninja?" target="_blank"><i class="fas fa-2x fa-user-ninja" id="tech--ninja"></i></a>

CSS output would be:

a[data-tool-tip]{
    position: relative;
    text-decoration: none;
    color: rgba(255,255,255,0.75);
}

a[data-tool-tip]::after{
    content: attr(data-tool-tip);
    display: block;
    position: absolute;
    background-color: dimgrey;
    padding: 1em 3em;
    color: white;
    border-radius: 5px;
    font-size: .5em;
    bottom: 0;
    left: -180%;
    white-space: nowrap;
    transform: scale(0);
    transition: 
    transform ease-out 150ms,
    bottom ease-out 150ms;
}

a[data-tool-tip]:hover::after{
    transform: scale(1);
    bottom: 200%;
}

Basically the attribute selector [data-tool-tip] selects the content of whatever's inside and allows you to animate it however you want.

Sending multipart/formdata with jQuery.ajax

I just built this function based on some info I read.

Use it like using .serialize(), instead just put .serializefiles();.
Working here in my tests.

//USAGE: $("#form").serializefiles();
(function($) {
$.fn.serializefiles = function() {
    var obj = $(this);
    /* ADD FILE TO PARAM AJAX */
    var formData = new FormData();
    $.each($(obj).find("input[type='file']"), function(i, tag) {
        $.each($(tag)[0].files, function(i, file) {
            formData.append(tag.name, file);
        });
    });
    var params = $(obj).serializeArray();
    $.each(params, function (i, val) {
        formData.append(val.name, val.value);
    });
    return formData;
};
})(jQuery);

Equivalent of SQL ISNULL in LINQ?

Looks like the type is boolean and therefore can never be null and should be false by default.

In Spring MVC, how can I set the mime type header when using @ResponseBody

My version of reality. Loading a HTML file and streaming to the browser.

@Controller
@RequestMapping("/")
public class UIController {

    @RequestMapping(value="index", method=RequestMethod.GET, produces = "text/html")
    public @ResponseBody String GetBootupFile() throws IOException  {
        Resource resource = new ClassPathResource("MainPage.html");
        String fileContents = FileUtils.readFileToString(resource.getFile());
        return fileContents;
    }
}

Unable instantiate android.gms.maps.MapFragment

I've this issue i just update Google Play services and make sure that you are adding the google-play-service-lib project as dependency, it's working now without any code change but i still getting "The Google Play services resources were not found. Check your project configuration to ensure that the resources are included." but this only happens when you have setMyLocationEnabled(true), anyone knows why?

rm: cannot remove: Permission denied

The code says everything:

max@serv$ chmod 777 .

Okay, it doesn't say everything.

In UNIX and Linux, the ability to remove a file is not determined by the access bits of that file. It is determined by the access bits of the directory which contains the file.

Think of it this way -- deleting a file doesn't modify that file. You aren't writing to the file, so why should "w" on the file matter? Deleting a file requires editing the directory that points to the file, so you need "w" on the that directory.

What is the difference between JDK and JRE?

JVM (Java Virtual Machine) is an abstract machine. It is a specification that provides runtime environment in which java bytecode can be executed.

JRE is an acronym for Java Runtime Environment.It is used to provide runtime environment.It is the implementation of JVM.It physically exists.It contains set of libraries + other files that JVM uses at runtime

JDK is an acronym for Java Development Kit.It physically exists.It contains JRE + development tools

Android ListView not refreshing after notifyDataSetChanged

Try this

@Override
public void onResume() {
super.onResume();
items.clear();
items = dbHelper.getItems(); //reload the items from database
adapter = new ItemAdapter(getActivity(), items);//reload the items from database
adapter.notifyDataSetChanged();
}

How to get time difference in minutes in PHP

A more universal version that returns result in days, hours, minutes or seconds including fractions/decimals:

function DateDiffInterval($sDate1, $sDate2, $sUnit='H') {
//subtract $sDate2-$sDate1 and return the difference in $sUnit (Days,Hours,Minutes,Seconds)
    $nInterval = strtotime($sDate2) - strtotime($sDate1);
    if ($sUnit=='D') { // days
        $nInterval = $nInterval/60/60/24;
    } else if ($sUnit=='H') { // hours
        $nInterval = $nInterval/60/60;
    } else if ($sUnit=='M') { // minutes
        $nInterval = $nInterval/60;
    } else if ($sUnit=='S') { // seconds
    }
    return $nInterval;
} //DateDiffInterval

MySQL Error: #1142 - SELECT command denied to user

So the issue I ran into was this... the application I used to grant the permissions converted the Schema.TableName into a single DB statement in the wrong table, so the grant was indeed wrong, but looked correct when we did a SHOW GRANTS FOR UserName if you weren't paying very close attention to GRANT SELECT vs GRANT TABLE SELECT. Manually correcting the Grant Select on Table w/ proper escaping of Schema.Table solved my issue.

May be unrelated, but I can imagine if one client does this wrong, another might too.

Hope that's helpful.

How can I search for a commit message on GitHub?

This works well from within Eclipse, until GitHub adds the feature:

Enter image description here

EGit/User Guide, Searching for commits

Is It Possible to NSLog C Structs (Like CGRect or CGPoint)?

I use the following macro to help me out with NSRect:

#define LogRect(RECT) NSLog(@"%s: (%0.0f, %0.0f) %0.0f x %0.0f",
    #RECT, RECT.origin.x, RECT.origin.y, RECT.size.width, RECT.size.height)

You could do something similar for CGPoint:

@define LogCGPoint(POINT) NSLog(@"%s: (%0.0f, %0.0f)",
    #POINT POINT.x, POINT.y);

Using it as follows:

LogCGPoint(cgPoint);

Would produce the following:

cgPoint: (100, 200)

What is sys.maxint in Python 3?

As pointed out by others, Python 3's int does not have a maximum size, but if you just need something that's guaranteed to be higher than any other int value, then you can use the float value for Infinity, which you can get with float("inf").

How do I overload the square-bracket operator in C#?

Here is an example returning a value from an internal List object. Should give you the idea.

  public object this[int index]
  {
     get { return ( List[index] ); }
     set { List[index] = value; }
  }

Python name 'os' is not defined

The problem is that you forgot to import os. Add this line of code:

import os

And everything should be fine. Hope this helps!

How Do I Upload Eclipse Projects to GitHub?

You need a git client to upload your project to git servers. For eclipse EGIT is a nice plugin to use GIT.

to learn the basic of git , see here // i think you should have the basic first

How to convert POJO to JSON and vice versa?

Use GSON for converting POJO to JSONObject. Refer here.

For converting JSONObject to POJO, just call the setter method in the POJO and assign the values directly from the JSONObject.

Is it possible to use Java 8 for Android development?

UPDATE 2020/01/17

Android Studio 4.0 includes support for using a number of Java 8 language APIs, by using technique called desugaring, without requiring a minimum API level for your app:
https://developer.android.com/studio/preview/features#j8-desugar

The following set of APIs is supported in this release:

  • Sequential streams (java.util.stream)
  • A subset of java.time
  • java.util.function
  • Recent additions to java.util.{Map,Collection,Comparator}
  • Optionals (java.util.Optional, java.util.OptionalInt and java.util.OptionalDouble) and some other new classes useful with the above APIs
  • Some additions to java.util.concurrent.atomic (new methods on AtomicInteger, AtomicLong and AtomicReference)
  • ConcurrentHashMap (with bug fixes for Android 5.0)

To support these language APIs, D8 compiles a separate library DEX file that contains an implementation of the missing APIs and includes it in your app. The desugaring process rewrites your app’s code to instead use this library at runtime.

To enable support for these language APIs, include the following in your module’s build.gradle file:

android {
  defaultConfig {
    // Required when setting minSdkVersion to 20 or lower
    multiDexEnabled true
  }

  compileOptions {
    // Flag to enable support for the new language APIs
    coreLibraryDesugaringEnabled true
    // Sets Java compatibility to Java 8
    sourceCompatibility JavaVersion.VERSION_1_8
    targetCompatibility JavaVersion.VERSION_1_8
  }
}

dependencies {
  coreLibraryDesugaring 'com.android.tools:desugar_jdk_libs:1.0.4'
}

ORIGINAL POST FROM 2017

Android Studio 3.0 started to provide built-in support for some of Java 8 language features, which are:

  • Lambda expressions
  • Method references
  • Type Annotations (information is available at compile time, but not at runtime)
  • Repeating annotations
  • Default and static interface methods

Also starting from API level 24 the following Java 8 API are available:

  • java.util.stream
  • java.util.function
  • java.lang.FunctionalInterface
  • java.lang.annotation.Repeatable
  • java.lang.reflect.AnnotatedElement.getAnnotationsByType(Class)
  • java.lang.reflect.Method.isDefault()

Besides that, the try-with-resources support was extended to all Android API levels.

More Java 8 features are promised to be added in the future.

To start using supported Java 8 language features, update the Android plugin to 3.0.0-alpha1 (or higher) and add the following to your module’s build.gradle file:

android {
  ...
  compileOptions {
    sourceCompatibility JavaVersion.VERSION_1_8
    targetCompatibility JavaVersion.VERSION_1_8
  }
}

For more details visit:
https://developer.android.com/studio/write/java8-support.html

Add Bootstrap Glyphicon to Input Box

If you are using Fontawesome you can do this :

<input type="text" style="font-family:Arial, FontAwesome"  placeholder="&#xf007;" />

Result

enter image description here

The complete list of unicode can be found in the The complete Font Awesome 4.6.3 icon reference

String concatenation in MySQL

MySQL is different from most DBMSs use of + or || for concatenation. It uses the CONCAT function:

SELECT CONCAT(first_name, " ", last_name) AS Name FROM test.student

As @eggyal pointed out in comments, you can enable string concatenation with the || operator in MySQL by setting the PIPES_AS_CONCAT SQL mode.

How to change heatmap.2 color range in R?

Here's another option for those not using heatmap.2 (aheatmap is good!)

Make a sequential vector of 100 values from min to max of your input matrix, find value closest to 0 in that, make two vector of colours to and from desired midpoint, combine and use them:

breaks <- seq(from=min(range(inputMatrix)), to=max(range(inputMatrix)), length.out=100)
midpoint <- which.min(abs(breaks - 0))
rampCol1 <- colorRampPalette(c("forestgreen", "darkgreen", "black"))(midpoint)
rampCol2 <- colorRampPalette(c("black", "darkred", "red"))(100-(midpoint+1))
rampCols <- c(rampCol1,rampCol2)

Linux / Bash, using ps -o to get process by specific name?

This is a bit old, but I guess what you want is: ps -o pid -C PROCESS_NAME, for example:

ps -o pid -C bash

EDIT: Dependening on the sort of output you expect, pgrep would be more elegant. This, in my knowledge, is Linux specific and result in similar output as above. For example:

pgrep bash

Default value in an asp.net mvc view model

Set this in the constructor:

public class SearchModel
{
    public bool IsMale { get; set; }
    public bool IsFemale { get; set; }

    public SearchModel()
    { 
        IsMale = true;
        IsFemale = true;
    }
}

Then pass it to the view in your GET action:

[HttpGet]
public ActionResult Search()
{
    return new View(new SearchModel());
}

Remove columns from dataframe where ALL values are NA

Try this:

df <- df[,colSums(is.na(df))<nrow(df)]

Check if a class `active` exist on element with jquery

$(document).ready(function()
{
  changeColor = $(.active).css("color","any color");
  if($(".classname").hasClass('active')) {
  $(this).eq(changeColor);
  }
});

Call to undefined function oci_connect()

I had the same issue, the solution on this page helped me, it's caused by using incompatible oci ddl files.

Hope it helps.

SQL JOIN vs IN performance?

This Thread is pretty old but still mentioned often. For my personal taste it is a bit incomplete, because there is another way to ask the database with the EXISTS keyword which I found to be faster more often than not.

So if you are only interested in values from table a you can use this query:

SELECT  a.*
FROM    a
WHERE   EXISTS (
    SELECT  *
    FROM    b
    WHERE   b.col = a.col
    )

The difference might be huge if col is not indexed, because the db does not have to find all records in b which have the same value in col, it only has to find the very first one. If there is no index on b.col and a lot of records in b a table scan might be the consequence. With IN or a JOIN this would be a full table scan, with EXISTS this would be only a partial table scan (until the first matching record is found).

If there a lots of records in b which have the same col value you will also waste a lot of memory for reading all these records into a temporary space just to find that your condition is satisfied. With exists this can be usually avoided.

I have often found EXISTS faster then IN even if there is an index. It depends on the database system (the optimizer), the data and last not least on the type of index which is used.

How to set the holo dark theme in a Android app?

By default android will set Holo to the Dark theme. There is no theme called Holo.Dark, there's only Holo.Light, that's why you are getting the resource not found error.

So just set it to:

<style name="AppTheme" parent="android:Theme.Holo" />

How to make clang compile to llvm IR

Given some C/C++ file foo.c:

> clang -S -emit-llvm foo.c

Produces foo.ll which is an LLVM IR file.

The -emit-llvm option can also be passed to the compiler front-end directly, and not the driver by means of -cc1:

> clang -cc1 foo.c -emit-llvm

Produces foo.ll with the IR. -cc1 adds some cool options like -ast-print. Check out -cc1 --help for more details.


To compile LLVM IR further to assembly, use the llc tool:

> llc foo.ll

Produces foo.s with assembly (defaulting to the machine architecture you run it on). llc is one of the LLVM tools - here is its documentation.

MySQL - Operand should contain 1 column(s)

This error can also occur if you accidentally miss if function name.

for example:

set v_filter_value = 100;

select
    f_id,
    f_sale_value
from
    t_seller
where
    f_id = 5
    and (v_filter_value <> 0, f_sale_value = v_filter_value, true);

Got this problem when I missed putting if in the if function!

NodeJS - What does "socket hang up" actually mean?

Another case worth mentioning (for Linux and OS X) is that if you use a library like https for performing the requests, or if you pass https://... as a URL of the locally served instance, you will be using port 443 which is a reserved private port and you might be ending up in Socket hang up or ECONNREFUSED errors.

Instead, use port 3000, f.e., and do an http request.

The network path was not found

This is probably related to your database connection string or something like that.

I just solved this exception right now. What was happening is that I was using a connection string intended to be used when debugging in a different machine (the server).

I commented the wrong connection string in Web.config and uncommented the right one. Now I'm back in business... this is something I forget to look at after sometime not working in a given solution. ;)

Android Left to Right slide animation

Use this xml in res/anim/

This is for left to right animation:

<set xmlns:android="http://schemas.android.com/apk/res/android"
     android:shareInterpolator="false">
  <translate android:fromXDelta="-100%" android:toXDelta="0%"
             android:fromYDelta="0%" android:toYDelta="0%"
             android:duration="700"/>
</set>

This is for right to left animation:

<set xmlns:android="http://schemas.android.com/apk/res/android"
     android:shareInterpolator="false">
  <translate
     android:fromXDelta="0%" android:toXDelta="100%"
     android:fromYDelta="0%" android:toYDelta="0%"
     android:duration="700" />
</set>

In your coding use intent like for left to right:

this.overridePendingTransition(R.anim.animation_enter,
                   R.anim.animation_leave);

In your coding use intent like for right to left

this.overridePendingTransition(R.anim.animation_leave,
                               R.anim.animation_enter);

How to declare 2D array in bash

2D array can be achieved in bash by declaring 1D array and then elements can be accessed using (r * col_size) + c). Below logic delcares 1D array (str_2d_arr) and prints as 2D array.

col_size=3
str_2d_arr=()
str_2d_arr+=('abc' '200' 'xyz')
str_2d_arr+=('def' '300' 'ccc')
str_2d_arr+=('aaa' '400' 'ddd')

echo "Print 2D array"
col_count=0
for elem in ${str_2d_arr[@]}; do
    if [ ${col_count} -eq ${col_size} ]; then
        echo ""
        col_count=0
    fi
    echo -e "$elem \c"
    ((col_count++))
done
echo ""

Output is

Print 2D array
abc 200 xyz 
def 300 ccc
aaa 400 ddd

Below logic is very useful to get each row from the above declared 1D array str_2d_arr.

# Get nth row and update to 2nd arg
get_row_n()
{
    row=$1
    local -n a=$2
    start_idx=$((row * col_size))
    for ((i = 0; i < ${col_size}; i++)); do
        idx=$((start_idx + i))
        a+=(${str_2d_arr[${idx}]})
    done
}

arr=()
get_row_n 0 arr
echo "Row 0"
for e in ${arr[@]}; do
    echo -e "$e \c"
done
echo ""

Output is

Row 0
abc 200 xyz

Tomcat request timeout

You can set the default time out in the server.xml

<Connector URIEncoding="UTF-8" 
    acceptCount="100" 
    connectionTimeout="20000" 
    disableUploadTimeout="true" 
    enableLookups="false" 
    maxHttpHeaderSize="8192" 
    maxSpareThreads="75" 
    maxThreads="150" 
    minSpareThreads="25" 
    port="7777" 
    redirectPort="8443"/>

When should an IllegalArgumentException be thrown?

When talking about "bad input", you should consider where the input is coming from.

Is the input entered by a user or another external system you don't control, you should expect the input to be invalid, and always validate it. It's perfectly ok to throw a checked exception in this case. Your application should 'recover' from this exception by providing an error message to the user.

If the input originates from your own system, e.g. your database, or some other parts of your application, you should be able to rely on it to be valid (it should have been validated before it got there). In this case it's perfectly ok to throw an unchecked exception like an IllegalArgumentException, which should not be caught (in general you should never catch unchecked exceptions). It is a programmer's error that the invalid value got there in the first place ;) You need to fix it.

New warnings in iOS 9: "all bitcode will be dropped"

After Xcode 7, the bitcode option will be enabled by default. If your library was compiled without bitcode, but the bitcode option is enabled in your project settings, you can:

  1. Update your library with bit code,
  2. Say NO to Enable Bitcode in your target Build Settings

Enter image description here

And the Library Build Settings to remove the warnings.

For more information, go to documentation of bitcode in developer library.

And WWDC 2015 Session 102: "Platforms State of the Union"

Enter image description here

How to capture no file for fs.readFileSync()?

You have to catch the error and then check what type of error it is.

try {
  var data = fs.readFileSync(...)
} catch (err) {
  // If the type is not what you want, then just throw the error again.
  if (err.code !== 'ENOENT') throw err;

  // Handle a file-not-found error
}

How to Set the Background Color of a JButton on the Mac OS

Based on your own purposes, you can do that based on setOpaque(true/false) and setBorderPainted(true/false); try and combine them to fit your purpose

Preventing SQL injection in Node.js

In regards to testing if a module you are utilizing is secure or not there are several routes you can take. I will touch on the pros/cons of each so you can make a more informed decision.

Currently, there aren't any vulnerabilities for the module you are utilizing, however, this can often lead to a false sense of security as there very well could be a vulnerability currently exploiting the module/software package you are using and you wouldn't be alerted to a problem until the vendor applies a fix/patch.

  1. To keep abreast of vulnerabilities you will need to follow mailing lists, forums, IRC & other hacking related discussions. PRO: You can often times you will become aware of potential problems within a library before a vendor has been alerted or has issued a fix/patch to remedy the potential avenue of attack on their software. CON: This can be very time consuming and resource intensive. If you do go this route a bot using RSS feeds, log parsing (IRC chat logs) and or a web scrapper using key phrases (in this case node-mysql-native) and notifications can help reduce time spent trolling these resources.

  2. Create a fuzzer, use a fuzzer or other vulnerability framework such as metasploit, sqlMap etc. to help test for problems that the vendor may not have looked for. PRO: This can prove to be a sure fire method of ensuring to an acceptable level whether or not the module/software you are implementing is safe for public access. CON: This also becomes time consuming and costly. The other problem will stem from false positives as well as uneducated review of the results where a problem resides but is not noticed.

Really security, and application security in general can be very time consuming and resource intensive. One thing managers will always use is a formula to determine the cost effectiveness (manpower, resources, time, pay etc) of performing the above two options.

Anyways, I realize this is not a 'yes' or 'no' answer that may have been hoping for but I don't think anyone can give that to you until they perform an analysis of the software in question.

Counting words in string

Here's a function that counts number of words in an HTML code:

$(this).val()
    .replace(/((&nbsp;)|(<[^>]*>))+/g, '') // remove html spaces and tags
    .replace(/\s+/g, ' ') // merge multiple spaces into one
    .trim() // trim ending and beginning spaces (yes, this is needed)
    .match(/\s/g) // find all spaces by regex
    .length // get amount of matches

ValueError: not enough values to unpack (expected 11, got 1)

Looks like something is wrong with your data, it isn't in the format you are expecting. It could be a new line character or a blank space in the data that is tinkering with your code.

What does .class mean in Java?

It means, the Class reference type can hold any Class object which represents any type. If JVM loads a type, a class object representing that type will be present in JVM. we can get the metadata regarding the type from that class object which is used very much in reflection package.

Suppose you have a a class named "myPackage.MyClass". Assuming that is in classpath, the following statements are equivalent.

Class<?> myClassObject = MyClass.class; //compile time check

Class<?> myClassObject = Class.forname("myPackage.MyClass"); //only runtime check

This works in a similar fashion if the Class<?> reference is in method argument as well.

Please note that the class "Class" does not have a public constructor. So you cannot instantiate "Class" instances with "new" operator.

HTTP Basic: Access denied fatal: Authentication failed

Before digging into the solution lets first see why this happens.

Before any transaction with git that your machine does git checks for your authentication which can be done using

  1. An SSH key token present in your machine and shared with git-repo(most preferred) OR
  2. Using your username/password (mostly used)

Why did this happen

In simple words, this happened because the credentials stored in your machine are not authentic i.e.there are chances that your password stored in the machine has changed from whats there in git therefore

Solution

Head towards, control panel and search for Credential Manager look for your use git url and change the creds.

There you go this works with mostly every that windows keep track off

Set type for function parameters?

You can implement a system that handles the type checks automatically, using a wrapper in your function.

With this approach, you can build a complete declarative type check system that will manage for you the type checks . If you are interested in taking a more in depth look at this concept, check the Functyped library

The following implementation illustrates the main idea, in a simplistic, but operative way :

_x000D_
_x000D_
/*_x000D_
 * checkType() : Test the type of the value. If succeds return true, _x000D_
 * if fails, throw an Error_x000D_
 */_x000D_
function checkType(value,type, i){_x000D_
  // perform the appropiate test to the passed _x000D_
  // value according to the provided type_x000D_
  switch(type){_x000D_
    case Boolean : _x000D_
      if(typeof value === 'boolean') return true;_x000D_
      break;_x000D_
    case String : _x000D_
      if(typeof value === 'string') return true;_x000D_
      break;_x000D_
    case Number : _x000D_
      if(typeof value === 'number') return true;_x000D_
      break;_x000D_
    default :_x000D_
      throw new Error(`TypeError : Unknown type provided in argument ${i+1}`);_x000D_
  }_x000D_
  // test didn't succeed , throw error_x000D_
  throw new Error(`TypeError : Expecting a ${type.name} in argument ${i+1}`);_x000D_
}_x000D_
_x000D_
_x000D_
/*_x000D_
 * typedFunction() : Constructor that returns a wrapper_x000D_
 * to handle each function call, performing automatic _x000D_
 * arguments type checking_x000D_
 */_x000D_
function typedFunction( parameterTypes, func ){_x000D_
  // types definitions and function parameters _x000D_
  // count must match_x000D_
  if(parameterTypes.length !== func.length) throw new Error(`Function has ${func.length} arguments, but type definition has ${parameterTypes.length}`);_x000D_
  // return the wrapper..._x000D_
  return function(...args){_x000D_
    // provided arguments count must match types_x000D_
    // definitions count_x000D_
    if(parameterTypes.length !== args.length) throw new Error(`Function expects ${func.length} arguments, instead ${args.length} found.`);_x000D_
    // iterate each argument value, and perform a_x000D_
    // type check against it, using the type definitions_x000D_
    // provided in the construction stage_x000D_
    for(let i=0; i<args.length;i++) checkType( args[i], parameterTypes[i] , i)_x000D_
    // if no error has been thrown, type check succeed_x000D_
    // execute function!_x000D_
    return func(...args);_x000D_
  }_x000D_
}_x000D_
_x000D_
// Play time! _x000D_
// Declare a function that expects 2 Numbers_x000D_
let myFunc = typedFunction( [ Number, Number ],  (a,b)=>{_x000D_
  return a+b;_x000D_
});_x000D_
_x000D_
// call the function, with an invalid second argument_x000D_
myFunc(123, '456')_x000D_
// ERROR! Uncaught Error: TypeError : Expecting a Number in argument 2
_x000D_
_x000D_
_x000D_

What is the difference between an int and an Integer in Java and C#?

Well, in Java an int is a primitive while an Integer is an Object. Meaning, if you made a new Integer:

Integer i = new Integer(6);

You could call some method on i:

String s = i.toString();//sets s the string representation of i

Whereas with an int:

int i = 6;

You cannot call any methods on it, because it is simply a primitive. So:

String s = i.toString();//will not work!!!

would produce an error, because int is not an object.

int is one of the few primitives in Java (along with char and some others). I'm not 100% sure, but I'm thinking that the Integer object more or less just has an int property and a whole bunch of methods to interact with that property (like the toString() method for example). So Integer is a fancy way to work with an int (Just as perhaps String is a fancy way to work with a group of chars).

I know that Java isn't C, but since I've never programmed in C this is the closest I could come to the answer. Hope this helps!

Integer object javadoc

Integer Ojbect vs. int primitive comparison

Programmatically add new column to DataGridView

Here's a sample method that adds two extra columns programmatically to the grid view:

    private void AddColumnsProgrammatically()
    {
        // I created these columns at function scope but if you want to access 
        // easily from other parts of your class, just move them to class scope.
        // E.g. Declare them outside of the function...
        var col3 = new DataGridViewTextBoxColumn();
        var col4 = new DataGridViewCheckBoxColumn();

        col3.HeaderText = "Column3";
        col3.Name = "Column3";

        col4.HeaderText = "Column4";
        col4.Name = "Column4";

        dataGridView1.Columns.AddRange(new DataGridViewColumn[] {col3,col4});
    }

A great way to figure out how to do this kind of process is to create a form, add a grid view control and add some columns. (This process will actually work for ANY kind of form control. All instantiation and initialization happens in the Designer.) Then examine the form's Designer.cs file to see how the construction takes place. (Visual Studio does everything programmatically but hides it in the Form Designer.)

For this example I created two columns for the view named Column1 and Column2 and then searched Form1.Designer.cs for Column1 to see everywhere it was referenced. The following information is what I gleaned and, copied and modified to create two more columns dynamically:

// Note that this info scattered throughout the designer but can easily collected.

        System.Windows.Forms.DataGridViewTextBoxColumn Column1;
        System.Windows.Forms.DataGridViewCheckBoxColumn Column2;

        this.Column1 = new System.Windows.Forms.DataGridViewTextBoxColumn();
        this.Column2 = new System.Windows.Forms.DataGridViewCheckBoxColumn();

        this.dataGridView1.Columns.AddRange(new System.Windows.Forms.DataGridViewColumn[] {
        this.Column1,
        this.Column2});

        this.Column1.HeaderText = "Column1";
        this.Column1.Name = "Column1";

        this.Column2.HeaderText = "Column2";
        this.Column2.Name = "Column2";

Embed image in a <button> element

Add new folder with name of Images in your project. Put some images into Images folder. Then it will work fine.

<input type="image" src="~/Images/Desert.jpg" alt="Submit" width="48" height="48">

Unable to set default python version to python3 in ubuntu

get python path from

ls /usr/bin/python*

then set your python version

alias python="/usr/bin/python3"

How do I comment on the Windows command line?

The command you're looking for is rem, short for "remark".

There is also a shorthand version :: that some people use, and this sort of looks like # if you squint a bit and look at it sideways. I originally preferred that variant since I'm a bash-aholic and I'm still trying to forget the painful days of BASIC :-)

Unfortunately, there are situations where :: stuffs up the command line processor (such as within complex if or for statements) so I generally use rem nowadays. In any case, it's a hack, suborning the label infrastructure to make it look like a comment when it really isn't. For example, try replacing rem with :: in the following example and see how it works out:

if 1==1 (
    rem comment line 1
    echo 1 equals 1
    rem comment line 2
)

You should also keep in mind that rem is a command, so you can't just bang it at the end of a line like the # in bash. It has to go where a command would go. For example, only the second of these two will echo the single word hello:

echo hello rem a comment.
echo hello & rem a comment.

How to check if a file exists in Go?

As mentioned in other answers, it is possible to construct the required behaviour / errors from using different flags with os.OpenFile. In fact, os.Create is just a sensible-defaults shorthand for doing so:

// Create creates or truncates the named file. If the file already exists,
// it is truncated. If the file does not exist, it is created with mode 0666
// (before umask). If successful, methods on the returned File can
// be used for I/O; the associated file descriptor has mode O_RDWR.
// If there is an error, it will be of type *PathError.
func Create(name string) (*File, error) {
    return OpenFile(name, O_RDWR|O_CREATE|O_TRUNC, 0666)
}

You should combine these flags yourself to get the behaviour you are interested in:

// Flags to OpenFile wrapping those of the underlying system. Not all
// flags may be implemented on a given system.
const (
    // Exactly one of O_RDONLY, O_WRONLY, or O_RDWR must be specified.
    O_RDONLY int = syscall.O_RDONLY // open the file read-only.
    O_WRONLY int = syscall.O_WRONLY // open the file write-only.
    O_RDWR   int = syscall.O_RDWR   // open the file read-write.
    // The remaining values may be or'ed in to control behavior.
    O_APPEND int = syscall.O_APPEND // append data to the file when writing.
    O_CREATE int = syscall.O_CREAT  // create a new file if none exists.
    O_EXCL   int = syscall.O_EXCL   // used with O_CREATE, file must not exist.
    O_SYNC   int = syscall.O_SYNC   // open for synchronous I/O.
    O_TRUNC  int = syscall.O_TRUNC  // truncate regular writable file when opened.
)

Depending on what you pick, you will get different errors.

Here's an example where I wish to open a file for writing, but I will only truncate an existing file if the user has said that is OK:

var f *os.File
if truncateWhenExists {
    // O_TRUNC - truncate regular writable file when opened.
    if f, err = os.OpenFile(filepath, os.O_RDWR|os.O_CREATE|os.O_TRUNC, 0644); err != nil {
        log.Fatalln("failed to force-open file, err:", err)
    }
} else {
    // O_EXCL - used with O_CREATE, file must not exist
    if f, err = os.OpenFile(filepath, os.O_RDWR|os.O_CREATE|os.O_EXCL, 0644); err != nil {
        log.Fatalln("failed to open file, err:", err) 
   }
}

Why doesn't Git ignore my specified file?

I tried most commands above on VS Code terminal and I got errors like:

fatal: pathspec '[dir]/[file]' did not match any files

I opened the project on GitHub Desktop and ignored from there and it worked.

XXHDPI and XXXHDPI dimensions in dp for images and icons in android

You can use a vector. Instead of worry about different screen sizes you only need to create an .svg file and import it to your project using Vector Asset Studio.

How do I use itertools.groupby()?

One useful example that I came across may be helpful:

from itertools import groupby

#user input

myinput = input()

#creating empty list to store output

myoutput = []

for k,g in groupby(myinput):

    myoutput.append((len(list(g)),int(k)))

print(*myoutput)

Sample input: 14445221

Sample output: (1,1) (3,4) (1,5) (2,2) (1,1)

Typescript export vs. default export

Named export

In TS you can export with the export keyword. It then can be imported via import {name} from "./mydir";. This is called a named export. A file can export multiple named exports. Also the names of the imports have to match the exports. For example:

// foo.js file
export class foo{}
export class bar{}

// main.js file in same dir
import {foo, bar} from "./foo";

The following alternative syntax is also valid:

// foo.js file
function foo() {};
function bar() {};
export {foo, bar};

// main.js file in same dir
import {foo, bar} from './foo'

Default export

We can also use a default export. There can only be one default export per file. When importing a default export we omit the square brackets in the import statement. We can also choose our own name for our import.

// foo.js file
export default class foo{}

// main.js file in same directory
import abc from "./foo";

It's just JavaScript

Modules and their associated keyword like import, export, and export default are JavaScript constructs, not typescript. However typescript added the exporting and importing of interfaces and type aliases to it.

Center an item with position: relative

Much simpler:

position: relative; 
left: 50%;
transform: translateX(-50%);

You are now centered in your parent element. You can do that vertically too.

Changing background colour of tr element on mouseover

You could try:

tr:hover {
    background-color: #000;
}

tr:hover td {
    background-color: transparent; /* or #000 */
}

JS Fiddle demo.

Play sound on button click android

  • The audio must be placed in the raw folder, if it doesn't exists, create one.
  • The raw folder must be inside the res folder
  • The name mustn't have any - or special characters in it.

On your activity, you need to have a object MediaPlayer, inside the onCreate method or the onclick method, you have to initialize the MediaPlayer, like MediaPlayer.create(this, R.raw.name_of_your_audio_file), then your audio file ir ready to be played with the call for start(), in your case, since you want it to be placed in a button, you'll have to put it inside the onClick method.

Example:

private Button myButton;
private MediaPlayer mp;
@Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.myactivity);
        mp = MediaPlayer.create(this, R.raw.gunshot);

        myButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                mp.start();
            }
        });
}
}

Toggle visibility property of div

According to the jQuery docs, calling toggle() without parameters will toggle visibility.

$('#play-pause').click(function(){
   $('#video-over').toggle();
});

http://jsfiddle.net/Q47ya/

LINQ syntax where string value is not null or empty

http://connect.microsoft.com/VisualStudio/feedback/ViewFeedback.aspx?FeedbackID=367077

Problem Statement
It's possible to write LINQ to SQL that gets all rows that have either null or an empty string in a given field, but it's not possible to use string.IsNullOrEmpty to do it, even though many other string methods map to LINQ to SQL. Proposed Solution Allow string.IsNullOrEmpty in a LINQ to SQL where clause so that these two queries have the same result:

var fieldNullOrEmpty =
from item in db.SomeTable
where item.SomeField == null || item.SomeField.Equals(string.Empty)
select item;

var fieldNullOrEmpty2 =
from item in db.SomeTable
where string.IsNullOrEmpty(item.SomeField)
select item;

Other Reading:
1. DevArt
2. Dervalp.com
3. StackOverflow Post

Access denied for user 'root'@'localhost' while attempting to grant privileges. How do I grant privileges?

One simple solution which always works for me when faced with mysql "access denied" errors: use sudo.

sudo mysql -u root

Then the necessary permissions exist for GRANT commands.

Get a list of checked checkboxes in a div using jQuery

 var agencias = [];
 $('#Div input:checked').each(function(index, item){
 agencias.push(item.nextElementSibling.attributes.for.nodeValue);
 });

What is the difference between display: inline and display: inline-block?

splattne's answer probably covered most of everything so I won't repeat the same thing, but: inline and inline-block behave differently with the direction CSS property.

Within the next snippet you see one two (in order) is rendered, like it does in LTR layouts. I suspect the browser here auto-detected the English part as LTR text and rendered it from left to right.

_x000D_
_x000D_
body {_x000D_
  text-align: right;_x000D_
  direction: rtl;_x000D_
}_x000D_
_x000D_
h2 {_x000D_
  display: block; /* just being explicit */_x000D_
}_x000D_
_x000D_
span {_x000D_
  display: inline;_x000D_
}
_x000D_
<h2>_x000D_
  ??? ????? ????_x000D_
  <span>one</span>_x000D_
  <span>two</span>_x000D_
</h2>
_x000D_
_x000D_
_x000D_

However, if I go ahead and set display to inline-block, the browser appears to respect the direction property and render the elements from right to left in order, so that two one is rendered.

_x000D_
_x000D_
body {_x000D_
  text-align: right;_x000D_
  direction: rtl;_x000D_
}_x000D_
_x000D_
h2 {_x000D_
  display: block; /* just being explicit */_x000D_
}_x000D_
_x000D_
span {_x000D_
  display: inline-block;_x000D_
}
_x000D_
<h2>_x000D_
  ??? ????? ????_x000D_
  <span>one</span>_x000D_
  <span>two</span>_x000D_
</h2>
_x000D_
_x000D_
_x000D_

I don't know if there are any other quirks to this, I only found about this empirically on Chrome.

React : difference between <Route exact path="/" /> and <Route path="/" />

Please try this.

       <Router>
          <div>
            <Route exact path="/" component={Home} />
            <Route path="/news" component={NewsFeed} />
          </div>
        </Router> 

            

Visual Studio Code pylint: Unable to import 'protorpc'

Spent hours trying to fix the error for importing local modules. Code execution was fine but pylint showed:

    Unable to import '<module>'

Finally figured:

  1. First of all, select the correct python path. (In the case of a virtual environment, it will be venv/bin/python). You can do this by hitting

  2. Make sure that your pylint path is the same as the python path you chose in step 1. (You can open VS Code from within the activated venv from terminal so it automatically performs these two steps)

  3. The most important step: Add an empty __init__.py file in the folder that contains your module file. Although python3 does not require this file for importing modules, I think pylint still requires it for linting.

Restart VS Code, the errors should be gone!

How schedule build in Jenkins?

To build once a day between say 4PM to 6PM you can use

H H(15-17) * * *

Can I use multiple "with"?

Yes - just do it this way:

WITH DependencedIncidents AS
(
  ....
),  
lalala AS
(
  ....
)

You don't need to repeat the WITH keyword

Convert from enum ordinal to enum type

public enum Suit implements java.io.Serializable, Comparable<Suit>{
  spades, hearts, diamonds, clubs;
  private static final Suit [] lookup  = Suit.values();
  public Suit fromOrdinal(int ordinal) {
    if(ordinal< 1 || ordinal> 3) return null;
    return lookup[value-1];
  }
}

the test class

public class MainTest {
    public static void main(String[] args) {
        Suit d3 = Suit.diamonds;
        Suit d3Test = Suit.fromOrdinal(2);
        if(d3.equals(d3Test)){
            System.out.println("Susses");
        }else System.out.println("Fails");
    }
}

I appreciate that you share with us if you have a more efficient code, My enum is huge and constantly called thousands of times.

$(this).serialize() -- How to add a value?

While matt b's answer will work, you can also use .serializeArray() to get an array from the form data, modify it, and use jQuery.param() to convert it to a url-encoded form. This way, jQuery handles the serialisation of your extra data for you.

var data = $(this).serializeArray(); // convert form to array
data.push({name: "NonFormValue", value: NonFormValue});
$.ajax({
    type: 'POST',
    url: this.action,
    data: $.param(data),
});

Get pixel's RGB using PIL

Not PIL, but imageio.imread might still be interesting:

import imageio
im = scipy.misc.imread('um_000000.png', flatten=False, mode='RGB')
im = imageio.imread('Figure_1.png', pilmode='RGB')
print(im.shape)

gives

(480, 640, 3)

so it is (height, width, channels). So the pixel at position (x, y) is

color = tuple(im[y][x])
r, g, b = color

Outdated

scipy.misc.imread is deprecated in SciPy 1.0.0 (thanks for the reminder, fbahr!)

How to move an element into another element?

dirty size improvement of Bekim Bacaj answer

_x000D_
_x000D_
div { border: 1px solid ; margin: 5px }
_x000D_
<div id="source" onclick="destination.appendChild(this)">click me</div>_x000D_
<div id="destination" >...</div>
_x000D_
_x000D_
_x000D_

Replacing &nbsp; from javascript dom text node

for me replace doesn't work... try this code:

str = str.split("&quot;").join('"');

Easy login script without database

Save the username and password hashes in array in a php file instead of db.

When you need to authenticate the user, compute hashes of his credentials and then compare them to hashes in array.

If you use safe hash function (see hash function and hash algos in PHP documentation), it should be pretty safe (you may consider using salted hash) and also add some protections to the form itself.

Use find command but exclude files in two directories

Use

find \( -path "./tmp" -o -path "./scripts" \) -prune -o  -name "*_peaks.bed" -print

or

find \( -path "./tmp" -o -path "./scripts" \) -prune -false -o  -name "*_peaks.bed"

or

find \( -path "./tmp" -path "./scripts" \) ! -prune -o  -name "*_peaks.bed"

The order is important. It evaluates from left to right. Always begin with the path exclusion.

Explanation

Do not use -not (or !) to exclude whole directory. Use -prune. As explained in the manual:

-prune    The primary shall always evaluate as  true;  it
          shall  cause  find  not  to descend the current
          pathname if it is a directory.  If  the  -depth
          primary  is specified, the -prune primary shall
          have no effect.

and in the GNU find manual:

-path pattern
              [...]
              To ignore  a  whole
              directory  tree,  use  -prune rather than checking
              every file in the tree.

Indeed, if you use -not -path "./pathname", find will evaluate the expression for each node under "./pathname".

find expressions are just condition evaluation.

  • \( \) - groups operation (you can use -path "./tmp" -prune -o -path "./scripts" -prune -o, but it is more verbose).
  • -path "./script" -prune - if -path returns true and is a directory, return true for that directory and do not descend into it.
  • -path "./script" ! -prune - it evaluates as (-path "./script") AND (! -prune). It revert the "always true" of prune to always false. It avoids printing "./script" as a match.
  • -path "./script" -prune -false - since -prune always returns true, you can follow it with -false to do the same than !.
  • -o - OR operator. If no operator is specified between two expressions, it defaults to AND operator.

Hence, \( -path "./tmp" -o -path "./scripts" \) -prune -o -name "*_peaks.bed" -print is expanded to:

[ (-path "./tmp" OR -path "./script") AND -prune ] OR ( -name "*_peaks.bed" AND print )

The print is important here because without it is expanded to:

{ [ (-path "./tmp" OR -path "./script" )  AND -prune ]  OR (-name "*_peaks.bed" ) } AND print

-print is added by find - that is why most of the time, you do not need to add it in you expression. And since -prune returns true, it will print "./script" and "./tmp".

It is not necessary in the others because we switched -prune to always return false.

Hint: You can use find -D opt expr 2>&1 1>/dev/null to see how it is optimized and expanded,
find -D search expr 2>&1 1>/dev/null to see which path is checked.

Set colspan dynamically with jquery

You'd need to remove the blank table cell element entirely, and change the colspan attribute on another cell in the row to encompass the released space, e.g.:

refToCellToRemove.remove();
refTocellToExpand.colspan = 4;

Note that setting it via setAttribute (which would otherwise be correct) will not work properly on IE.

Beware: IE does some very strange table layout things when you muck about with colspans dynamically. If you can avoid it, I would.

How to calculate difference between two dates in oracle 11g SQL

You can not use DATEDIFF but you can use this (if columns are not date type):

SELECT 
to_date('2008-08-05','YYYY-MM-DD')-to_date('2008-06-05','YYYY-MM-DD') 
AS DiffDate from dual

you can see the sample

http://sqlfiddle.com/#!4/d41d8/34609

how to implement regions/code collapse in javascript

On VS 2012 and VS 2015 install WebEssentials plugin and you will able to do so.

http://vswebessentials.com/features/javascript

VBScript - How to make program wait until process has finished?

This may not specifically answer your long 3 part question but this thread is old and I found this while searching today. Here is one shorter way to: "Wait until a process has finished." If you know the name of the process such as "EXCEL.EXE"

strProcess = "EXCEL.EXE"    
Set objWMIService = GetObject("winmgmts:{impersonationLevel=impersonate}!\\.\root\cimv2")
Set colProcesses = objWMIService.ExecQuery ("Select * from Win32_Process Where Name = '"& strProcess &"'")
Do While colProcesses.Count > 0
    Set colProcesses = objWMIService.ExecQuery ("Select * from Win32_Process Where Name = '"& strProcess &"'")
    Wscript.Sleep(1000) 'Sleep 1 second
   'msgbox colProcesses.count 'optional to show the loop works
Loop

Credit to: http://crimsonshift.com/scripting-check-if-process-or-program-is-running-and-start-it/

How do I resolve a TesseractNotFoundError?

I was also facing the same issue, just add C:\Program Files (x86)\Tesseract-OCR to your path variable. If it still does not work, add C:\Program Files (x86)\Tesseract-OCR\tessdata to your path variable in a new line. And do not forget to restart your computer after adding the path variable.

Inheritance and Overriding __init__ in python

In each class that you need to inherit from, you can run a loop of each class that needs init'd upon initiation of the child class...an example that can copied might be better understood...

class Female_Grandparent:
    def __init__(self):
        self.grandma_name = 'Grandma'

class Male_Grandparent:
    def __init__(self):
        self.grandpa_name = 'Grandpa'

class Parent(Female_Grandparent, Male_Grandparent):
    def __init__(self):
        Female_Grandparent.__init__(self)
        Male_Grandparent.__init__(self)

        self.parent_name = 'Parent Class'

class Child(Parent):
    def __init__(self):
        Parent.__init__(self)
#---------------------------------------------------------------------------------------#
        for cls in Parent.__bases__: # This block grabs the classes of the child
             cls.__init__(self)      # class (which is named 'Parent' in this case), 
                                     # and iterates through them, initiating each one.
                                     # The result is that each parent, of each child,
                                     # is automatically handled upon initiation of the 
                                     # dependent class. WOOT WOOT! :D
#---------------------------------------------------------------------------------------#



g = Female_Grandparent()
print g.grandma_name

p = Parent()
print p.grandma_name

child = Child()

print child.grandma_name

Regex to Match Symbols: !$%^&*()_+|~-=`{}[]:";'<>?,./

// The string must contain at least one special character, escaping reserved RegEx characters to avoid conflict
  const hasSpecial = password => {
    const specialReg = new RegExp(
      '^(?=.*[!@#$%^&*"\\[\\]\\{\\}<>/\\(\\)=\\\\\\-_´+`~\\:;,\\.€\\|])',
    );
    return specialReg.test(password);
  };

How to get commit history for just one branch?

I think an option for your purposes is git log --online --decorate. This lets you know the checked commit, and the top commits for each branch that you have in your story line. By doing this, you have a nice view on the structure of your repo and the commits associated to a specific branch. I think reading this might help.

How do you allow spaces to be entered using scanf?

You may use scanf for this purpose with a little trick. Actually, you should allow user input until user hits Enter (\n). This will consider every character, including space. Here is example:

int main()
{
  char string[100], c;
  int i;
  printf("Enter the string: ");
  scanf("%s", string);
  i = strlen(string);      // length of user input till first space
  do
  {
    scanf("%c", &c);
    string[i++] = c;       // reading characters after first space (including it)
  } while (c != '\n');     // until user hits Enter
  string[i - 1] = 0;       // string terminating
return 0;
}

How this works? When user inputs characters from standard input, they will be stored in string variable until first blank space. After that, rest of entry will remain in input stream, and wait for next scanf. Next, we have a for loop that takes char by char from input stream (till \n) and apends them to end of string variable, thus forming a complete string same as user input from keyboard.

Hope this will help someone!

How to find index of all occurrences of element in array?

You can use Polyfill

if (!Array.prototype.filterIndex) {
Array.prototype.filterIndex = function (func, thisArg) {

    'use strict';
    if (!((typeof func === 'Function' || typeof func === 'function') && this))
        throw new TypeError();

    let len = this.length >>> 0,
        res = new Array(len), // preallocate array
        t = this, c = 0, i = -1;

    let kValue;
    if (thisArg === undefined) {
        while (++i !== len) {
            // checks to see if the key was set
            if (i in this) {
                kValue = t[i]; // in case t is changed in callback
                if (func(t[i], i, t)) {
                    res[c++] = i;
                }
            }
        }
    }
    else {
        while (++i !== len) {
            // checks to see if the key was set
            if (i in this) {
                kValue = t[i];
                if (func.call(thisArg, t[i], i, t)) {
                    res[c++] = i;
                }
            }
        }
    }

    res.length = c; // shrink down array to proper size
    return res;
};

}

Use it like this:

[2,23,1,2,3,4,52,2].filterIndex(element => element === 2)

result: [0, 3, 7]

Print a file's last modified date in Bash

EDITED: turns out that I had forgotten the quotes needed for $entry in order to print correctly and not give the "no such file or directory" error. Thank you all so much for helping me!

Here is my final code:

    echo "Please type in the directory you want all the files to be listed with last modified dates" #bash can't find file creation dates

read directory

for entry in "$directory"/*

do
modDate=$(stat -c %y "$entry") #%y = last modified. Qoutes are needed otherwise spaces in file name with give error of "no such file"
modDate=${modDate%% *} #%% takes off everything off the string after the date to make it look pretty
echo $entry:$modDate

Prints out like this:

/home/joanne/Dropbox/cheat sheet.docx:2012-03-14
/home/joanne/Dropbox/Comp:2013-05-05
/home/joanne/Dropbox/Comp 150 java.zip:2013-02-11
/home/joanne/Dropbox/Comp 151 Java 2.zip:2013-02-11
/home/joanne/Dropbox/Comp 162 Assembly Language.zip:2013-02-11
/home/joanne/Dropbox/Comp 262 Comp Architecture.zip:2012-12-12
/home/joanne/Dropbox/Comp 345 Image Processing.zip:2013-02-11
/home/joanne/Dropbox/Comp 362 Operating Systems:2013-05-05
/home/joanne/Dropbox/Comp 447 Societal Issues.zip:2013-02-11

Get checkbox list values with jQuery

Try this one..

var listCheck = [];
console.log($("input[name='YourCheckBokName[]']"));
$("input[name='YourCheckBokName[]']:checked").each(function() {
     console.log($(this).val());
     listCheck .push($(this).val());
});
console.log(listCheck);

Loop through files in a folder in matlab

Looping through all the files in the folder is relatively easy:

files = dir('*.csv');
for file = files'
    csv = load(file.name);
    % Do some stuff
end

Why is a "GRANT USAGE" created the first time I grant a user privileges?

I was trying to find the meaning of GRANT USAGE on *.* TO and found here. I can clarify that GRANT USAGE on *.* TO user IDENTIFIED BY PASSWORD password will be granted when you create the user with the following command (CREATE):

CREATE USER 'user'@'localhost' IDENTIFIED BY 'password'; 

When you grant privilege with GRANT, new privilege s will be added on top of it.

Java properties UTF-8 encoding in Eclipse

Properties props = new Properties();
URL resource = getClass().getClassLoader().getResource("data.properties");         
props.load(new InputStreamReader(resource.openStream(), "UTF8"));

this works well in java 1.6. How can i do this in 1.5, Since Properties class does not have a method to pars InputStreamReader.

Developing for Android in Eclipse: R.java not regenerating

When nothing seems to work correctly even though you think that everything is right, check your XML files one by one. The mistake is there 100%.

If you work with the GUI of the XML files everything seems OK, but when you enter textual XML files you see the mess inside. Eclipse is a bit buggy for this stuff.

Set BuildAutomatically as well, so after you fix your errors you will have your R.java file in the generated ones.... GOOD LUCK!!!

What strategies and tools are useful for finding memory leaks in .NET?

one of the best tools I used its DotMemory.you can use this tool as an extension in VS.after run your app you can analyze every part of memory(by Object, NameSpace, etc) that your app use and take some snapshot of that, Compare it with other SnapShots. DotMemory

Child element click event trigger the parent click event

Click event Bubbles, now what is meant by bubbling, a good point to starts is here. you can use event.stopPropagation(), if you don't want that event should propagate further.

Also a good link to refer on MDN

Oracle: how to add minutes to a timestamp?

Based on what you're asking for, you want the HH24:MI format for to_char.

How to access the first property of a Javascript object?

Use an array instead of an object (square brackets).

var example = [ {/* stuff1 */}, { /* stuff2 */}, { /* stuff3 */}];
var fist = example[0];

Note that you lose the 'foo' identifiers. But you could add a name property to the contained objects:

var example = [ 
  {name: 'foo1', /* stuff1 */},
  {name: 'foo2', /* stuff2 */},
  {name: 'foo3', /* stuff3 */}
];
var whatWasFirst = example[0].name;

Why do I need to configure the SQL dialect of a data source?

Hibernate.dialect property tells Hibernate to generate the appropriate SQL statements for the chosen database.

A list of available dialects can be found here: http://javamanikandan.blogspot.in/2014/05/sql-dialects-in-hibernate.html

RDBMS                   Dialect
DB2                     org.hibernate.dialect.DB2Dialect
DB2 AS/400              org.hibernate.dialect.DB2400Dialect
DB2 OS390               org.hibernate.dialect.DB2390Dialect
PostgreSQL              org.hibernate.dialect.PostgreSQLDialect
MySQL                   org.hibernate.dialect.MySQLDialect
MySQL with InnoDB       org.hibernate.dialect.MySQLInnoDBDialect
MySQL with MyISAM       org.hibernate.dialect.MySQLMyISAMDialect
Oracle (any version)    org.hibernate.dialect.OracleDialect
Oracle 9i/10g           org.hibernate.dialect.Oracle9Dialect
Sybase                  org.hibernate.dialect.SybaseDialect
Sybase Anywhere         org.hibernate.dialect.SybaseAnywhereDialect
Microsoft SQL Server    org.hibernate.dialect.SQLServerDialect
SAP DB                  org.hibernate.dialect.SAPDBDialect
Informix                org.hibernate.dialect.InformixDialect
HypersonicSQL           org.hibernate.dialect.HSQLDialect
Ingres                  org.hibernate.dialect.IngresDialect
Progress                org.hibernate.dialect.ProgressDialect
Mckoi SQL               org.hibernate.dialect.MckoiDialect
Interbase               org.hibernate.dialect.InterbaseDialect
Pointbase               org.hibernate.dialect.PointbaseDialect
FrontBase               org.hibernate.dialect.FrontbaseDialect
Firebird                org.hibernate.dialect.FirebirdDialect

Converting HTML string into DOM elements?

Just give an id to the element and process it normally eg:

<div id="dv">
<a href="#"></a>
<span></span>
</div>

Now you can do like:

var div = document.getElementById('dv');
div.appendChild(......);

Or with jQuery:

$('#dv').get(0).appendChild(........);

Merge/flatten an array of arrays

You can use Ramda JS flatten

_x000D_
_x000D_
var arr = [[1,2], [3], [4,5]];_x000D_
var flattenedArray = R.flatten(arr); _x000D_
_x000D_
console.log(flattenedArray)
_x000D_
<script src="https://cdnjs.cloudflare.com/ajax/libs/ramda/0.25.0/ramda.js"></script>
_x000D_
_x000D_
_x000D_

Submit form without page reloading

I've found what I think is an easier way. If you put an Iframe in the page, you can redirect the exit of the action there and make it show up. You can do nothing, of course. In that case, you can set the iframe display to none.

<iframe name="votar" style="display:none;"></iframe>
<form action="tip.php" method="post" target="votar">
    <input type="submit" value="Skicka Tips">
    <input type="hidden" name="ad_id" value="2">            
</form>

What is lexical scope?

IBM defines it as:

The portion of a program or segment unit in which a declaration applies. An identifier declared in a routine is known within that routine and within all nested routines. If a nested routine declares an item with the same name, the outer item is not available in the nested routine.

Example 1:

function x() {
    /*
    Variable 'a' is only available to function 'x' and function 'y'.
    In other words the area defined by 'x' is the lexical scope of
    variable 'a'
    */
    var a = "I am a";

    function y() {
        console.log( a )
    }
    y();

}
// outputs 'I am a'
x();

Example 2:

function x() {

    var a = "I am a";

    function y() {
         /*
         If a nested routine declares an item with the same name,
         the outer item is not available in the nested routine.
         */
        var a = 'I am inner a';
        console.log( a )
    }
    y();

}
// outputs 'I am inner a'
x();

Matching a Forward Slash with a regex

In regular expressions, "/" is a special character which needs to be escaped (AKA flagged by placing a \ before it thus negating any specialized function it might serve).

Here's what you need:

var word = /\/(\w+)/ig; //   /abc Match

Read up on RegEx special characters here: http://www.regular-expressions.info/characters.html

How to get all keys with their values in redis

Yes, you can do print all keys using below bash script,

for key in $(redis-cli -p 6379 keys \*);
  do echo "Key : '$key'" 
     redis-cli -p 6379 GET $key;
done

where, 6379 is a port on which redis is running.

How to style a JSON block in Github Wiki?

You can use some online websites to beautify JSON, such as: JSON Formatter, and then paste the beautified result to WIKI

li:before{ content: "¦"; } How to Encode this Special Character as a Bullit in an Email Stationery?

This website could be helpful,

http://character-code.com

here you can copy it and put directly on css html

Is the Javascript date object always one day off?

The best way to handle this without using more conversion methods,

 var mydate='2016,3,3';
 var utcDate = Date.parse(mydate);
 console.log(" You're getting back are 20.  20h + 4h = 24h :: "+utcDate);

Now just add GMT in your date or you can append it.

 var  mydateNew='2016,3,3'+ 'GMT';
 var utcDateNew = Date.parse(mydateNew);
 console.log("the right time that you want:"+utcDateNew)

Live: https://jsfiddle.net/gajender/2kop9vrk/1/

Emulate ggplot2 default color palette

From page 106 of the ggplot2 book by Hadley Wickham:

The default colour scheme, scale_colour_hue picks evenly spaced hues around the hcl colour wheel.

With a bit of reverse engineering you can construct this function:

ggplotColours <- function(n = 6, h = c(0, 360) + 15){
  if ((diff(h) %% 360) < 1) h[2] <- h[2] - 360/n
  hcl(h = (seq(h[1], h[2], length = n)), c = 100, l = 65)
}

Demonstrating this in barplot:

y <- 1:3
barplot(y, col = ggplotColours(n = 3))

enter image description here

Case insensitive access for generic dictionary

There is much simpler way:

using System;
using System.Collections.Generic;
....
var caseInsensitiveDictionary = new Dictionary<string, string>(StringComparer.OrdinalIgnoreCase);

Add zero-padding to a string

string strvalue="11".PadRight(4, '0');

output= 1100

string strvalue="301".PadRight(4, '0');

output= 3010

string strvalue="11".PadLeft(4, '0');

output= 0011

string strvalue="301".PadLeft(4, '0');

output= 0301

How to insert a timestamp in Oracle?

First of all you need to make the field Nullable, then after that so simple - instead of putting a value put this code CURRENT_TIMESTAMP.

Unsupported operation :not writeable python

You open the variable "file" as a read only then attempt to write to it:

file = open('ValidEmails.txt','r')

Instead, use the 'w' flag.

file = open('ValidEmails.txt','w')
...
file.write(email)

How to check visibility of software keyboard in Android?

This is probably not suitable for production because it will open the keyboard. Note that the boolean returned by similar functions is not specified in the API and are therefore unreliable. Refer to the documentation here...

https://developer.android.com/reference/android/view/inputmethod/InputMethodManager#showSoftInput(android.view.View,%20int,%20android.os.ResultReceiver)

public boolean showSoftInput (View view, 
            int flags, 
            ResultReceiver resultReceiver)

Note that this method takes a ResultReceiver. It can get the results: RESULT_UNCHANGED_SHOWN, RESULT_UNCHANGED_HIDDEN, RESULT_SHOWN, or RESULT_HIDDEN. If you get RESULT_UNCHANGED_SHOWN, the keyboard was visible. If you need it to stay closed if it was closed, you will need to close it.

Java word count program

Java does have StringTokenizer API and can be used for this purpose as below.

String test = "This is a test app";
int countOfTokens = new StringTokenizer(test).countTokens();
System.out.println(countOfTokens);

OR

in a single line as below

System.out.println(new StringTokenizer("This is a test app").countTokens());

StringTokenizer supports multiple spaces in the input string, counting only the words trimming unnecessary spaces.

System.out.println(new StringTokenizer("This    is    a test    app").countTokens());

Above line also prints 5

How to change lowercase chars to uppercase using the 'keyup' event?

Plain ol' javascript:

var input = document.getElementById('inputID');

input.onkeyup = function(){
    this.value = this.value.toUpperCase();
}

Javascript with jQuery:

$('#inputID').keyup(function(){
    this.value = this.value.toUpperCase();
});

NoSql vs Relational database

The biggest advantage of NoSQL over RDBMS is Scalability.
NoSQL databases can easily scale-out to many nodes, but for RDBMS it is very hard.
Scalability not only gives you more storage space but also much higher performance since many hosts work at the same time.

Displaying tooltip on mouse hover of a text

This is not elegant, but you might be able to use the RichTextBox.GetCharIndexFromPosition method to return to you the index of the character that the mouse is currently over, and then use that index to figure out if it's over a link, hotspot, or any other special area. If it is, show your tooltip (and you'd probably want to pass the mouse coordinates into the tooltip's Show method, instead of just passing in the textbox, so that the tooltip can be positioned next to the link).

Example here: http://msdn.microsoft.com/en-us/library/system.windows.forms.richtextbox.getcharindexfromposition(VS.80).aspx

Use Font Awesome icon as CSS content

Update for FontAwesome 5 Thanks to Aurelien

You need to change the font-family to Font Awesome 5 Brands OR Font Awesome 5 Free, based on the type of icon you are trying to render. Also, do not forget to declare font-weight: 900;

a:before {
   font-family: "Font Awesome 5 Free";
   content: "\f095";
   display: inline-block;
   padding-right: 3px;
   vertical-align: middle;
   font-weight: 900;
}

Demo

You can read the rest of the answer below to understand how it works and to know some workarounds for spacing between icon and the text.


FontAwesome 4 and below

That's the wrong way to use it. Open the font awesome style sheet, go to the class of the font you want to use say fa-phone, copy the content property under that class with the entity, and use it like:

a:before {
    font-family: FontAwesome;
    content: "\f095";
}

Demo

Just make sure that if you are looking to target a specific a tag, then consider using a class instead to make it more specific like:

a.class_name:before {
    font-family: FontAwesome;
    content: "\f095";
}

Using the way above will stick the icon with the remaining text of yours, so if you want to have a bit of space between the two of them, make it display: inline-block; and use some padding-right:

a:before {
    font-family: FontAwesome;
    content: "\f095";
    display: inline-block;
    padding-right: 3px;
    vertical-align: middle;
}

Extending this answer further, since many might be having a requirement to change an icon on hover, so for that, we can write a separate selector and rules for :hover action:

a:hover:before {
    content: "\f099"; /* Code of the icon you want to change on hover */
}

Demo

Now in the above example, icon nudges because of the different size and you surely don't want that, so you can set a fixed width on the base declaration like

a:before {
    /* Other properties here, look in the above code snippets */
    width: 12px; /* add some desired width here to prevent nudge */
}

Demo

Examples of GoF Design Patterns in Java's core libraries

Even though I'm sort of a broken clock with this one, Java XML API uses Factory a lot. I mean just look at this:

Document doc = DocumentBuilderFactory.newInstance().newDocumentBuilder().parse(source);
String title = XPathFactory.newInstance().newXPath().evaluate("//title", doc);

...and so on and so forth.

Additionally various Buffers (StringBuffer, ByteBuffer, StringBuilder) use Builder.

How to display binary data as image - extjs 4

The data URI format is:

data:<headers>;<encoding>,<data>

So, you need only append your data to the "data:image/jpeg;," string:

var your_binary_data = document.body.innerText.replace(/(..)/gim,'%$1'); // parse text data to URI format

window.open('data:image/jpeg;,'+your_binary_data);

Android: Access child views from a ListView

See: Android ListView: get data index of visible item and combine with part of Feet's answer above, can give you something like:

int wantedPosition = 10; // Whatever position you're looking for
int firstPosition = listView.getFirstVisiblePosition() - listView.getHeaderViewsCount(); // This is the same as child #0
int wantedChild = wantedPosition - firstPosition;
// Say, first visible position is 8, you want position 10, wantedChild will now be 2
// So that means your view is child #2 in the ViewGroup:
if (wantedChild < 0 || wantedChild >= listView.getChildCount()) {
  Log.w(TAG, "Unable to get view for desired position, because it's not being displayed on screen.");
  return;
}
// Could also check if wantedPosition is between listView.getFirstVisiblePosition() and listView.getLastVisiblePosition() instead.
View wantedView = listView.getChildAt(wantedChild);

The benefit is that you aren't iterating over the ListView's children, which could take a performance hit.

Add a tooltip to a div

You can toggle a child div during onmouseover and onmouseout like this:

function Tooltip(el, text) {
  el.onmouseover = function() {
    el.innerHTML += '<div class="tooltip">' + text + '</div>' 
    }
  el.onmouseout = function() {
    el.removeChild(el.querySelector(".tooltip"))
  }
}

//Sample Usage
Tooltip(document.getElementById("mydiv"),"hello im a tip div")

Example in Stack Snippets & jsFiddle

_x000D_
_x000D_
function Tooltip(el, text) {_x000D_
  el.onmouseover = function() {_x000D_
    el.innerHTML += '<div class="tooltip">' + text + '</div>'_x000D_
  }_x000D_
  el.onmouseout = function() {_x000D_
    el.removeChild(el.querySelector(".tooltip"))_x000D_
  }_x000D_
}_x000D_
_x000D_
//Sample Usage_x000D_
Tooltip(document.getElementById("mydiv"), "I'm a tooltip")
_x000D_
#mydiv {_x000D_
  position: relative;_x000D_
  display: flex;_x000D_
  align-items: center;_x000D_
  justify-content: center;_x000D_
  width: 120px;_x000D_
  height: 50px;_x000D_
  padding: 5px 10px;_x000D_
  background-color: #e2f7ff;_x000D_
  box-shadow: 1px 1px 1px 0px #cecece;_x000D_
}_x000D_
_x000D_
.tooltip {_x000D_
  position: absolute;_x000D_
  display: inline-block;_x000D_
  white-space: nowrap;_x000D_
  width: auto;_x000D_
  height: auto;_x000D_
  background-color: #11121b;_x000D_
  color: white;_x000D_
  padding: 4px 6px;_x000D_
  border-radius: 3px;_x000D_
  z-index: 99;_x000D_
  left: 100%;_x000D_
  top: 0;_x000D_
}
_x000D_
<div id="mydiv"> This is just a div </div>
_x000D_
_x000D_
_x000D_

How does numpy.histogram() work?

A bin is range that represents the width of a single bar of the histogram along the X-axis. You could also call this the interval. (Wikipedia defines them more formally as "disjoint categories".)

The Numpy histogram function doesn't draw the histogram, but it computes the occurrences of input data that fall within each bin, which in turns determines the area (not necessarily the height if the bins aren't of equal width) of each bar.

In this example:

 np.histogram([1, 2, 1], bins=[0, 1, 2, 3])

There are 3 bins, for values ranging from 0 to 1 (excl 1.), 1 to 2 (excl. 2) and 2 to 3 (incl. 3), respectively. The way Numpy defines these bins if by giving a list of delimiters ([0, 1, 2, 3]) in this example, although it also returns the bins in the results, since it can choose them automatically from the input, if none are specified. If bins=5, for example, it will use 5 bins of equal width spread between the minimum input value and the maximum input value.

The input values are 1, 2 and 1. Therefore, bin "1 to 2" contains two occurrences (the two 1 values), and bin "2 to 3" contains one occurrence (the 2). These results are in the first item in the returned tuple: array([0, 2, 1]).

Since the bins here are of equal width, you can use the number of occurrences for the height of each bar. When drawn, you would have:

  • a bar of height 0 for range/bin [0,1] on the X-axis,
  • a bar of height 2 for range/bin [1,2],
  • a bar of height 1 for range/bin [2,3].

You can plot this directly with Matplotlib (its hist function also returns the bins and the values):

>>> import matplotlib.pyplot as plt
>>> plt.hist([1, 2, 1], bins=[0, 1, 2, 3])
(array([0, 2, 1]), array([0, 1, 2, 3]), <a list of 3 Patch objects>)
>>> plt.show()

enter image description here

How to know Laravel version and where is it defined?

run php artisan --version from your console.

The version string is defined here:

https://github.com/laravel/framework/blob/master/src/Illuminate/Foundation/Application.php

/**
 * The Laravel framework version.
 *
 * @var string
 */
 const VERSION = '5.5-dev';

Excel formula to get cell color

Color is not data.

The Get.cell technique has flaws.

  1. It does not update as soon as the cell color changes, but only when the cell (or the sheet) is recalculated.
  2. It does not have sufficient numbers for the millions of colors that are available in modern Excel. See the screenshot and notice how the different intensities of yellow or purple all have the same number.

enter image description here

That does not surprise, since the Get.cell uses an old XML command, i.e. a command from the macro language Excel used before VBA was introduced. At that time, Excel colors were limited to less than 60.

Again: Color is not data.

If you want to color-code your cells, use conditional formatting based on the cell values or based on rules that can be expressed with logical formulas. The logic that leads to conditional formatting can also be used in other places to report on the data, regardless of the color value of the cell.

How to mount a host directory in a Docker container

There are a couple ways you can do this. The simplest way to do so is to use the dockerfile ADD command like so:

ADD . /path/inside/docker/container

However, any changes made to this directory on the host after building the dockerfile will not show up in the container. This is because when building a container, docker compresses the directory into a .tar and uploads that context into the container permanently.

The second way to do this is the way you attempted, which is to mount a volume. Due to trying to be as portable as possible you cannot map a host directory to a docker container directory within a dockerfile, because the host directory can change depending on which machine you are running on. To map a host directory to a docker container directory you need to use the -v flag when using docker run, e.g.,:

# Run a container using the `alpine` image, mount the `/tmp`
# directory from your host into the `/container/directory`
# directory in your container, and run the `ls` command to
# show the contents of that directory.
docker run \
    -v /tmp:/container/directory \
    alpine \
    ls /container/directory

How to replace all occurrences of a string in Javascript?

You can simply use below method

/**
 * Replace all the occerencess of $find by $replace in $originalString
 * @param  {originalString} input - Raw string.
 * @param  {find} input - Target key word or regex that need to be replaced.
 * @param  {replace} input - Replacement key word
 * @return {String}       Output string
 */
function replaceAll(originalString, find, replace) {
  return originalString.replace(new RegExp(find, 'g'), replace);
};

How is CountDownLatch used in Java Multithreading?

From oracle documentation about CountDownLatch:

A synchronization aid that allows one or more threads to wait until a set of operations being performed in other threads completes.

A CountDownLatch is initialized with a given count. The await methods block until the current count reaches zero due to invocations of the countDown() method, after which all waiting threads are released and any subsequent invocations of await return immediately. This is a one-shot phenomenon -- the count cannot be reset.

A CountDownLatch is a versatile synchronization tool and can be used for a number of purposes.

A CountDownLatch initialized with a count of one serves as a simple on/off latch, or gate: all threads invoking await wait at the gate until it is opened by a thread invoking countDown().

A CountDownLatch initialized to N can be used to make one thread wait until N threads have completed some action, or some action has been completed N times.

public void await()
           throws InterruptedException

Causes the current thread to wait until the latch has counted down to zero, unless the thread is interrupted.

If the current count is zero then this method returns immediately.

public void countDown()

Decrements the count of the latch, releasing all waiting threads if the count reaches zero.

If the current count is greater than zero then it is decremented. If the new count is zero then all waiting threads are re-enabled for thread scheduling purposes.

Explanation of your example.

  1. You have set count as 3 for latch variable

    CountDownLatch latch = new CountDownLatch(3);
    
  2. You have passed this shared latch to Worker thread : Processor

  3. Three Runnable instances of Processor have been submitted to ExecutorService executor
  4. Main thread ( App ) is waiting for count to become zero with below statement

     latch.await();  
    
  5. Processor thread sleeps for 3 seconds and then it decrements count value with latch.countDown()
  6. First Process instance will change latch count as 2 after it's completion due to latch.countDown().

  7. Second Process instance will change latch count as 1 after it's completion due to latch.countDown().

  8. Third Process instance will change latch count as 0 after it's completion due to latch.countDown().

  9. Zero count on latch causes main thread App to come out from await

  10. App program prints this output now : Completed

Catch checked change event of a checkbox

$(document).ready(function(){
    checkUncheckAll("#select_all","[name='check_boxes[]']");
});

var NUM_BOXES = 10;
// last checkbox the user clicked
var last = -1;
function check(event) {
  // in IE, the event object is a property of the window object
  // in Mozilla, event object is passed to event handlers as a parameter
  event = event || window.event;

  var num = parseInt(/box\[(\d+)\]/.exec(this.name)[1]);
  if (event.shiftKey && last != -1) {
    var di = num > last ? 1 : -1;
    for (var i = last; i != num; i += di)
      document.forms.boxes['box[' + i + ']'].checked = true;
  }
  last = num;
}
function init() {
  for (var i = 0; i < NUM_BOXES; i++)
    document.forms.boxes['box[' + i + ']'].onclick = check;
}

HTML:

<body onload="init()">
  <form name="boxes">
    <input name="box[0]" type="checkbox">
    <input name="box[1]" type="checkbox">
    <input name="box[2]" type="checkbox">
    <input name="box[3]" type="checkbox">
    <input name="box[4]" type="checkbox">
    <input name="box[5]" type="checkbox">
    <input name="box[6]" type="checkbox">
    <input name="box[7]" type="checkbox">
    <input name="box[8]" type="checkbox">
    <input name="box[9]" type="checkbox">
  </form>
</body>

How do I pass data to Angular routed components?

I think since we don't have $rootScope kind of thing in angular 2 as in angular 1.x. We can use angular 2 shared service/class while in ngOnDestroy pass data to service and after routing take the data from the service in ngOnInit function:

Here I am using DataService to share hero object:

import { Hero } from './hero';
export class DataService {
  public hero: Hero;
}

Pass object from first page component:

 ngOnDestroy() {
    this.dataService.hero = this.hero; 
 }

Take object from second page component:

 ngOnInit() {
    this.hero = this.dataService.hero; 
 }

Here is an example: plunker

Find specific string in a text file with VBS script

Try to change like this ..

firstStr = "<?xml version" 'my file always starts like this

Do until objInputFile.AtEndOfStream  

    strToAdd = "<tr><td><a href=" & chr(34) & "../../Logs/DD/Beginning_of_DD_TC" & CStr(index) & ".html" & chr(34) & ">Beginning_of_DD_TC" & CStr(index) & "</a></td></tr>"  

   substrToFind = "<tr><td><a href=" & chr(34) & "../Test case " & trim(cstr((index)))

   tmpStr = objInputFile.ReadLine

   If InStr(tmpStr, substrToFind) <= 0 Then
       If Instr(tmpStr, firstStr) > 0 Then
          text = tmpStr 'to avoid the first empty line
       Else
          text = text & vbCrLf & tmpStr
       End If
   Else
      text = text & vbCrLf & strToAdd & vbCrLf & tmpStr

   End If
   index = index + 1
Loop

Git: Permission denied (publickey) fatal - Could not read from remote repository. while cloning Git repository

I faced the same issue while running git clone command from windows command line. But the command runs successfully from Git Bash.

How to disable the resize grabber of <textarea>?

example of textarea for disable the resize option

<textarea CLASS="foo"></textarea>

<style>
textarea.foo
{
resize:none;
}

</style>

How to enable cross-origin resource sharing (CORS) in the express.js framework on node.js

One additional step I needed to take was to switch my URL from http://localhost to http://127.0.0.0

Excel VBA, How to select rows based on data in a column?

Yes using Option Explicit is a good habit. Using .Select however is not :) it reduces the speed of the code. Also fully justify sheet names else the code will always run for the Activesheet which might not be what you actually wanted.

Is this what you are trying?

Option Explicit

Sub Sample()
    Dim lastRow As Long, i As Long
    Dim CopyRange As Range

    '~~> Change Sheet1 to relevant sheet name
    With Sheets("Sheet1")
        lastRow = .Range("A" & .Rows.Count).End(xlUp).Row

        For i = 2 To lastRow
            If Len(Trim(.Range("A" & i).Value)) <> 0 Then
                If CopyRange Is Nothing Then
                    Set CopyRange = .Rows(i)
                Else
                    Set CopyRange = Union(CopyRange, .Rows(i))
                End If
            Else
                Exit For
            End If
        Next

        If Not CopyRange Is Nothing Then
            '~~> Change Sheet2 to relevant sheet name
            CopyRange.Copy Sheets("Sheet2").Rows(1)
        End If
    End With
End Sub

NOTE

If if you have data from Row 2 till Row 10 and row 11 is blank and then you have data again from Row 12 then the above code will only copy data from Row 2 till Row 10

If you want to copy all rows which have data then use this code.

Option Explicit

Sub Sample()
    Dim lastRow As Long, i As Long
    Dim CopyRange As Range

    '~~> Change Sheet1 to relevant sheet name
    With Sheets("Sheet1")
        lastRow = .Range("A" & .Rows.Count).End(xlUp).Row

        For i = 2 To lastRow
            If Len(Trim(.Range("A" & i).Value)) <> 0 Then
                If CopyRange Is Nothing Then
                    Set CopyRange = .Rows(i)
                Else
                    Set CopyRange = Union(CopyRange, .Rows(i))
                End If
            End If
        Next

        If Not CopyRange Is Nothing Then
            '~~> Change Sheet2 to relevant sheet name
            CopyRange.Copy Sheets("Sheet2").Rows(1)
        End If
    End With
End Sub

Hope this is what you wanted?

Sid

How to put wildcard entry into /etc/hosts?

It happens that /etc/hosts file doesn't support wild card entries.

You'll have to use other services like dnsmasq. To enable it in dnsmasq, just edit dnsmasq.conf and add the following line:

address=/example.com/127.0.0.1

How can I account for period (AM/PM) using strftime?

You used %H (24 hour format) instead of %I (12 hour format).

Can I call a constructor from another constructor (do constructor chaining) in C++?

I believe you can call a constructor from a constructor. It will compile and run. I recently saw someone do this and it ran on both Windows and Linux.

It just doesn't do what you want. The inner constructor will construct a temporary local object which gets deleted once the outer constructor returns. They would have to be different constructors as well or you would create a recursive call.

Ref: https://isocpp.org/wiki/faq/ctors#init-methods

Enter triggers button click

Where ever you use a <button> element by default it considers that button type="submit" so if you define the button type="button" then it won't consider that <button> as submit button.

Check if something is (not) in a list in Python

The bug is probably somewhere else in your code, because it should work fine:

>>> 3 not in [2, 3, 4]
False
>>> 3 not in [4, 5, 6]
True

Or with tuples:

>>> (2, 3) not in [(2, 3), (5, 6), (9, 1)]
False
>>> (2, 3) not in [(2, 7), (7, 3), "hi"]
True

Disabling swap files creation in vim

To disable swap files from within vim, type

:set noswapfile

To disable swap files permanently, add the below to your ~/.vimrc file

set noswapfile

For more details see the Vim docs on swapfile

postgresql - replace all instances of a string within text field

Here is an example that replaces all instances of 1 or more white space characters in a column with an underscore using regular expression -

select distinct on (pd)
regexp_replace(rndc.pd, '\\s+', '_','g') as pd
from rndc14_ndc_mstr rndc;

How to check the version of GitLab?

You have two choices (after logged in).

  1. Use API url https://gitlab.example.com/api/v4/version (you can use it from command line with private token), it returns {"version":"10.1.0","revision":"5a695c4"}
  2. Use HELP url in browser https://gitlab.example.com/help and you will see version of GitLab, ie GitLab Community Edition 10.1.0 5a695c4

Where does Android app package gets installed on phone

An application when installed on a device or on an emulator will install at:

/data/data/APP_PACKAGE_NAME

The APK itself is placed in the /data/app/ folder.

These paths, however, are in the System Partition and to access them, you will need to have root. This is for a device. On the emulator, you can see it in your logcat (DDMS) in the File Explorer tab

By the way, it only shows the package name that is defined in your Manifest.XML under the package="APP_PACKAGE_NAME" attribute. Any other packages you may have created in your project in Eclipse do not show up here.

How to execute .sql script file using JDBC

I had the same problem trying to execute an SQL script that creates an SQL database. Googling here and there I found a Java class initially written by Clinton Begin which supports comments (see http://pastebin.com/P14HsYAG). I modified slightly the file to cater for triggers where one has to change the default DELIMITER to something different. I've used that version ScriptRunner (see http://pastebin.com/sb4bMbVv). Since an (open source and free) SQLScriptRunner class is an absolutely necessary utility, it would be good to have some more input from developers and hopefully we'll have soon a more stable version of it.

lexical or preprocessor issue file not found occurs while archiving?

Just adding another thing that worked for me :

react-native link

Evidently my ReactNative files were no longer there. I could figure that out by clicking on

Build Phases -> Link Binary with Libraries ->

Then right clicking a file I knew was responsible for React, and clicking Show In Finder .

But nothing opened. So assuming the library went missing, I just ran the above command which relinked everything again.

Also if you havn't, try :

rm -rf node_modules/ && npm install

Why isn't my Pandas 'apply' function referencing multiple columns working?

Let's say we want to apply a function add5 to columns 'a' and 'b' of DataFrame df

def add5(x):
    return x+5

df[['a', 'b']].apply(add5)

Syntax error due to using a reserved word as a table or column name in MySQL

The Problem

In MySQL, certain words like SELECT, INSERT, DELETE etc. are reserved words. Since they have a special meaning, MySQL treats it as a syntax error whenever you use them as a table name, column name, or other kind of identifier - unless you surround the identifier with backticks.

As noted in the official docs, in section 10.2 Schema Object Names (emphasis added):

Certain objects within MySQL, including database, table, index, column, alias, view, stored procedure, partition, tablespace, and other object names are known as identifiers.

...

If an identifier contains special characters or is a reserved word, you must quote it whenever you refer to it.

...

The identifier quote character is the backtick ("`"):

A complete list of keywords and reserved words can be found in section 10.3 Keywords and Reserved Words. In that page, words followed by "(R)" are reserved words. Some reserved words are listed below, including many that tend to cause this issue.

  • ADD
  • AND
  • BEFORE
  • BY
  • CALL
  • CASE
  • CONDITION
  • DELETE
  • DESC
  • DESCRIBE
  • FROM
  • GROUP
  • IN
  • INDEX
  • INSERT
  • INTERVAL
  • IS
  • KEY
  • LIKE
  • LIMIT
  • LONG
  • MATCH
  • NOT
  • OPTION
  • OR
  • ORDER
  • PARTITION
  • RANK
  • REFERENCES
  • SELECT
  • TABLE
  • TO
  • UPDATE
  • WHERE

The Solution

You have two options.

1. Don't use reserved words as identifiers

The simplest solution is simply to avoid using reserved words as identifiers. You can probably find another reasonable name for your column that is not a reserved word.

Doing this has a couple of advantages:

  • It eliminates the possibility that you or another developer using your database will accidentally write a syntax error due to forgetting - or not knowing - that a particular identifier is a reserved word. There are many reserved words in MySQL and most developers are unlikely to know all of them. By not using these words in the first place, you avoid leaving traps for yourself or future developers.

  • The means of quoting identifiers differs between SQL dialects. While MySQL uses backticks for quoting identifiers by default, ANSI-compliant SQL (and indeed MySQL in ANSI SQL mode, as noted here) uses double quotes for quoting identifiers. As such, queries that quote identifiers with backticks are less easily portable to other SQL dialects.

Purely for the sake of reducing the risk of future mistakes, this is usually a wiser course of action than backtick-quoting the identifier.

2. Use backticks

If renaming the table or column isn't possible, wrap the offending identifier in backticks (`) as described in the earlier quote from 10.2 Schema Object Names.

An example to demonstrate the usage (taken from 10.3 Keywords and Reserved Words):

mysql> CREATE TABLE interval (begin INT, end INT);
ERROR 1064 (42000): You have an error in your SQL syntax.
near 'interval (begin INT, end INT)'

mysql> CREATE TABLE `interval` (begin INT, end INT); Query OK, 0 rows affected (0.01 sec)

Similarly, the query from the question can be fixed by wrapping the keyword key in backticks, as shown below:

INSERT INTO user_details (username, location, `key`)
VALUES ('Tim', 'Florida', 42)";               ^   ^

Navigation bar show/hide

In Swift try this,

navigationController?.isNavigationBarHidden = true  //Hide
navigationController?.isNavigationBarHidden = false //Show

or

navigationController?.setNavigationBarHidden(true, animated: true) //Hide
navigationController?.setNavigationBarHidden(false, animated: true) //Show

Given a view, how do I get its viewController?

A little bit late, but here's an extension that enable you to find a responder of any type, including ViewController.

extension NSObject{
func findNext(type: AnyClass) -> Any{
    var resp = self as! UIResponder

    while !resp.isKind(of: type.self) && resp.next != nil
    {
        resp = resp.next!
    }

    return resp
  }                       
}

Wait some seconds without blocking UI execution

If possible, the preferred approach should be using an asynchronous way or a second thread.

If this isn't possible or wanted, using any implementation of DoEvents() is a bad idea, since it may cause problems Possible problems with DoEvents. This is mostly about DoEvents with Winforms but the possible pitfalls in WPF are the same.

Then putting a frame on the Dispatcher with the wanted sleep time can be used:

using System;
using System.Threading;
using System.Windows.Threading;

public static void NonBlockingSleep(int timeInMilliseconds)
{
    DispatcherFrame df = new DispatcherFrame();

    new Thread((ThreadStart)(() =>
    {
        Thread.Sleep(TimeSpan.FromMilliseconds(timeInMilliseconds));
        df.Continue = false;

    })).Start();

    Dispatcher.PushFrame(df);
}

What's onCreate(Bundle savedInstanceState)

onCreate(Bundle savedInstanceState) Function in Android:

  1. When an Activity first call or launched then onCreate(Bundle savedInstanceState) method is responsible to create the activity.

  2. When ever orientation(i.e. from horizontal to vertical or vertical to horizontal) of activity gets changed or when an Activity gets forcefully terminated by any Operating System then savedInstanceState i.e. object of Bundle Class will save the state of an Activity.

  3. After Orientation changed then onCreate(Bundle savedInstanceState) will call and recreate the activity and load all data from savedInstanceState.

  4. Basically Bundle class is used to stored the data of activity whenever above condition occur in app.

  5. onCreate() is not required for apps. But the reason it is used in app is because that method is the best place to put initialization code.

  6. You could also put your initialization code in onStart() or onResume() and when you app will load first, it will work same as in onCreate().

Defining an abstract class without any abstract methods

Actually there is no mean if an abstract class doesnt have any abstract method . An abstract class is like a father. This father have some properties and behaviors,when you as a child want to be a child of the father, father says the child(you)that must be this way, its our MOTO, and if you don`t want to do, you are not my child.