Programs & Examples On #Cherokee

Cherokee is a fast, flexible and easy to configure Web Server.

A JNI error has occurred, please check your installation and try again in Eclipse x86 Windows 8.1

I faced a similar problem and than got the solution in the package name. I kept the package name as java.basics. In the console I got a hint for that as it clearly said Prohibited package name. So I changed package name and it worked.

How to check if object has any properties in JavaScript?

When sure that the object is a user-defined one, the easiest way to determine if UDO is empty, would be the following code:

isEmpty=
/*b.b Troy III p.a.e*/
function(x,p){for(p in x)return!1;return!0};

Even though this method is (by nature) a deductive one, - it's the quickest, and fastest possible.

a={};
isEmpty(a) >> true

a.b=1
isEmpty(a) >> false 

p.s.: !don't use it on browser-defined objects.

Error pushing to GitHub - insufficient permission for adding an object to repository database

If you still get this error later after setting the permissions you may need to modify your creation mask. We found our new commits (folders under objects) were still being created with no group write permission, hence only the person who committed them could push into the repository.

We fixed this by setting the umask of the SSH users to 002 with an appropriate group shared by all users.

e.g.

umask 002

where the middle 0 is allowing group write by default.

Is there a JavaScript strcmp()?

localeCompare() is slow, so if you don't care about the "correct" ordering of non-English-character strings, try your original method or the cleaner-looking:

str1 < str2 ? -1 : +(str1 > str2)

This is an order of magnitude faster than localeCompare() on my machine.

The + ensures that the answer is always numeric rather than boolean.

Dynamically set value of a file input

I ended up doing something like this for AngularJS in case someone stumbles across this question:

const imageElem = angular.element('#awardImg');

if (imageElem[0].files[0])
    vm.award.imageElem = imageElem;
    vm.award.image = imageElem[0].files[0];

And then:

if (vm.award.imageElem)
    $('#awardImg').replaceWith(vm.award.imageElem);
    delete vm.award.imageElem;

CORS: Cannot use wildcard in Access-Control-Allow-Origin when credentials flag is true

If you are using express you can use the cors package to allow CORS like so instead of writing your middleware;

var express = require('express')
, cors = require('cors')
, app = express();

app.use(cors());

app.get(function(req,res){ 
  res.send('hello');
});

How to iterate over a column vector in Matlab?

with many functions in matlab, you don't need to iterate at all.

for example, to multiply by it's position in the list:

m = [1:numel(list)]';
elm = list.*m;

vectorized algorithms in matlab are in general much faster.

phpmailer error "Could not instantiate mail function"

$mail->AddAddress($address, "her name");

should be changed to

$mail->AddAddress($address);

This worked for my case..

How to change the ROOT application?

You can do this in a slightly hack-y way by:

  1. Stop Tomcat
  2. Move ROOT.war aside and rm -rf webapps/ROOT
  3. Copy the webapp you want to webapps/ROOT.war
  4. Start Tomcat

First Heroku deploy failed `error code=H10`

The H10 error code could mean many different things. In my case, the first time was because I didn't know that Heroku isn't compatible with Sqlite3, the second time was because I accidentally pushed an update with Google analytics working in development as well as production.

How to change the href for a hyperlink using jQuery

This snippet invokes when a link of class 'menu_link' is clicked, and shows the text and url of the link. The return false prevents the link from being followed.

<a rel='1' class="menu_link" href="option1.html">Option 1</a>
<a rel='2' class="menu_link" href="option2.html">Option 2</a>

$('.menu_link').live('click', function() {
   var thelink = $(this);
   alert ( thelink.html() );
   alert ( thelink.attr('href') );
   alert ( thelink.attr('rel') );

   return false;
});

The first day of the current month in php using date_modify as DateTime object

Ugly, (and doesn't use your method call above) but works:

echo 'First day of the month: ' . date('m/d/y h:i a',(strtotime('this month',strtotime(date('m/01/y')))));   

Split string using a newline delimiter with Python

Here you go:

>>> data = """a,b,c
d,e,f
g,h,i
j,k,l"""
>>> data.split()  # split automatically splits through \n and space
['a,b,c', 'd,e,f', 'g,h,i', 'j,k,l']
>>> 

Convert cells(1,1) into "A1" and vice versa

The Address property of a cell can get this for you:

MsgBox Cells(1, 1).Address(RowAbsolute:=False, ColumnAbsolute:=False)

returns A1.

The other way around can be done with the Row and Column property of Range:

MsgBox Range("A1").Row & ", " & Range("A1").Column

returns 1,1.

How to pass the button value into my onclick event function?

You can do like this.

<input type="button" value="mybutton1" onclick="dosomething(this)">

function dosomething(element){
    alert("value is "+element.value); //you can print any value like id,class,value,innerHTML etc.
};

How to fix apt-get: command not found on AWS EC2?

I guess you are actually using Amazon Linux AMI 2013.03.1 instead of Ubuntu Server 12.x reason why you don't have apt-get tool installed.

How to convert list to string

By using ''.join

list1 = ['1', '2', '3']
str1 = ''.join(list1)

Or if the list is of integers, convert the elements before joining them.

list1 = [1, 2, 3]
str1 = ''.join(str(e) for e in list1)

Return file in ASP.Net Core Web API

If this is ASP.net-Core then you are mixing web API versions. Have the action return a derived IActionResult because in your current code the framework is treating HttpResponseMessage as a model.

[Route("api/[controller]")]
public class DownloadController : Controller {
    //GET api/download/12345abc
    [HttpGet("{id}"]
    public async Task<IActionResult> Download(string id) {
        Stream stream = await {{__get_stream_based_on_id_here__}}

        if(stream == null)
            return NotFound(); // returns a NotFoundResult with Status404NotFound response.

        return File(stream, "application/octet-stream"); // returns a FileStreamResult
    }    
}

How to clone an InputStream?

UPD. Check the comment before. It isn't exactly what was asked.

If you are using apache.commons you may copy streams using IOUtils .

You can use following code:

InputStream = IOUtils.toBufferedInputStream(toCopy);

Here is the full example suitable for your situation:

public void cloneStream() throws IOException{
    InputStream toCopy=IOUtils.toInputStream("aaa");
    InputStream dest= null;
    dest=IOUtils.toBufferedInputStream(toCopy);
    toCopy.close();
    String result = new String(IOUtils.toByteArray(dest));
    System.out.println(result);
}

This code requires some dependencies:

MAVEN

<dependency>
    <groupId>commons-io</groupId>
    <artifactId>commons-io</artifactId>
    <version>2.4</version>
</dependency>

GRADLE

'commons-io:commons-io:2.4'

Here is the DOC reference for this method:

Fetches entire contents of an InputStream and represent same data as result InputStream. This method is useful where,

Source InputStream is slow. It has network resources associated, so we cannot keep it open for long time. It has network timeout associated.

You can find more about IOUtils here: http://commons.apache.org/proper/commons-io/javadocs/api-2.4/org/apache/commons/io/IOUtils.html#toBufferedInputStream(java.io.InputStream)

How do I extract data from JSON with PHP?

https://paiza.io/projects/X1QjjBkA8mDo6oVh-J_63w

Check below code for converting json to array in PHP, If JSON is correct then json_decode() works well, and will return an array, But if malformed JSON, then It will return NULL,

<?php
function jsonDecode1($json){
    $arr = json_decode($json, true);
    return $arr;
}

// In case of malformed JSON, it will return NULL
var_dump( jsonDecode1($json) );

If malformed JSON, and you are expecting only array, then you can use this function,

<?php
function jsonDecode2($json){
    $arr = (array) json_decode($json, true);
    return $arr;
}

// In case of malformed JSON, it will return an empty array()
var_dump( jsonDecode2($json) );

If malformed JSON, and you want to stop code execution, then you can use this function,

<?php
function jsonDecode3($json){
    $arr = (array) json_decode($json, true);

    if(empty(json_last_error())){
        return $arr;
    }
    else{
        throw new ErrorException( json_last_error_msg() );
    }
}

// In case of malformed JSON, Fatal error will be generated
var_dump( jsonDecode3($json) );

You can use any function depends on your requirement,

How do I cast a string to integer and have 0 in case of error in the cast with PostgreSQL?

SUBSTRING may help for some cases, you can limit the size of the int.

SELECT CAST(SUBSTRING('X12312333333333', '([\d]{1,9})') AS integer);

How to execute a command prompt command from python

It's very simple. You need just two lines of code with just using the built-in function and also it takes the input and runs forever until you stop it. Also that 'cmd' in quotes, leave it and don't change it. Here is the code:

import os
os.system('cmd')

Now just run this code and see the whole windows command prompt in your python project!

How can I use delay() with show() and hide() in Jquery

from jquery api

Added to jQuery in version 1.4, the .delay() method allows us to delay the execution of functions that follow it in the queue. It can be used with the standard effects queue or with a custom queue. Only subsequent events in a queue are delayed; for example this will not delay the no-arguments forms of .show() or .hide() which do not use the effects queue.

http://api.jquery.com/delay/

Remote Linux server to remote linux server dir copy. How?

scp -r <directory> <username>@<targethost>:<targetdir>

Finding the second highest number in array

static int secondLargest(int[] input){
    int largest , secondlargest;

    if(input[0]>input[1])
    {
        largest=input[0];
        secondlargest = input[1];
    }
    else
    {
        secondlargest = input[0];
        largest =input[1];
    }
    for(int i =2 ;i<input.length;i++){
        if(input[i]>largest)
        {
            secondlargest  = largest;
            largest = input[i];
        }
        else if(input[i]>secondlargest){
            secondlargest = input[i];
        }

    }
    return secondlargest;
}

Groovy / grails how to determine a data type?

To determine the class of an object simply call:

someObject.getClass()

You can abbreviate this to someObject.class in most cases. However, if you use this on a Map it will try to retrieve the value with key 'class'. Because of this, I always use getClass() even though it's a little longer.

If you want to check if an object implements a particular interface or extends a particular class (e.g. Date) use:

(somObject instanceof Date)

or to check if the class of an object is exactly a particular class (not a subclass of it), use:

(somObject.getClass() == Date)

Inline <style> tags vs. inline css properties

To answer your direct question: neither of these is the preferred method. Use a separate file.

Inline styles should only be used as a last resort, or set by Javascript code. Inline styles have the highest level of specificity, so override your actual stylesheets. This can make them hard to control (you should avoid !important as well for the same reason).

An embedded <style> block is not recommended, because you lose the browser's ability to cache the stylesheet across multiple pages on your site.

So in short, wherever possible, you should put your styles into a separate CSS file.

Difference between uint32 and uint32_t

uint32_t is standard, uint32 is not. That is, if you include <inttypes.h> or <stdint.h>, you will get a definition of uint32_t. uint32 is a typedef in some local code base, but you should not expect it to exist unless you define it yourself. And defining it yourself is a bad idea.

Need a query that returns every field that contains a specified letter

You can use a cursor and temp table approach so you aren't doing full table scan each time. What this would be doing is populating the temp table with all of your keywords, and then with each string in the @letters XML, it would remove any records from the temp table. At the end, you only have records in your temp table that have each of your desired strings in it.

declare @letters xml

SET @letters = '&lt;letters&gt;
            &lt;letter&gt;a&lt;/letter&gt;
            &lt;letter&gt;b&lt;/letter&gt;
        &lt;/letters&gt;'

-- SELECTING LETTERS FROM THE XML
SELECT Letters.l.value('.', 'nvarchar(50)') AS letter
FROM @letters.nodes('/letters/letter') AS Letters(l)

-- CREATE A TEMP TABLE WE CAN DELETE FROM IF A RECORD DOESN'T HAVE THE LETTER
CREATE TABLE #TempResults (keywordID int not null, keyWord nvarchar(50) not null)
INSERT INTO #TempResults (keywordID, keyWord)
SELECT employeeID, firstName FROM Employee

-- CREATE A CURSOR, SO WE CAN LOOP THROUGH OUR LETTERS AND REMOVE KEYWORDS THAT DON'T MATCH
DECLARE Cursor_Letters CURSOR READ_ONLY
FOR 
    SELECT Letters.l.value('.', 'nvarchar(50)') AS letter
    FROM @letters.nodes('/letters/letter') AS Letters(l)

DECLARE @letter varchar(50)
OPEN Cursor_Letters

FETCH NEXT FROM Cursor_Letters INTO @letter
WHILE (@@fetch_status <> -1)
BEGIN
    IF (@@fetch_status <> -2)
    BEGIN
        DELETE FROM #TempResults 
        WHERE  keywordID NOT IN 
        (SELECT keywordID FROM #TempResults WHERE keyWord LIKE '%' + @letter + '%')
    END
    FETCH NEXT FROM Cursor_Letters INTO @letter
END

CLOSE Cursor_Letters
DEALLOCATE Cursor_Letters

SELECT * FROM #TempResults

DROP Table #TempResults
GO

Checkout Jenkins Pipeline Git SCM with credentials?

You can use the following in a pipeline:

git branch: 'master',
    credentialsId: '12345-1234-4696-af25-123455',
    url: 'ssh://[email protected]:company/repo.git'

If you're using the ssh url then your credentials must be username + private key. If you're using the https clone url instead of the ssh one, then your credentials should be username + password.

repaint() in Java

You may need to call frame.repaint() as well to force the frame to actually redraw itself. I've had issues before where I tried to repaint a component and it wasn't updating what was displayed until the parent's repaint() method was called.

How to remove leading and trailing whitespace in a MySQL field?

you can use ltrim or rtrim to clean whitespaces for the right or left or a string.

How to center a WPF app on screen?

xaml

<Window ... WindowStartupLocation="CenterScreen">...

How do I make a https post in Node Js without any third party module?

For example, like this:

const querystring = require('querystring');
const https = require('https');

var postData = querystring.stringify({
    'msg' : 'Hello World!'
});

var options = {
  hostname: 'posttestserver.com',
  port: 443,
  path: '/post.php',
  method: 'POST',
  headers: {
       'Content-Type': 'application/x-www-form-urlencoded',
       'Content-Length': postData.length
     }
};

var req = https.request(options, (res) => {
  console.log('statusCode:', res.statusCode);
  console.log('headers:', res.headers);

  res.on('data', (d) => {
    process.stdout.write(d);
  });
});

req.on('error', (e) => {
  console.error(e);
});

req.write(postData);
req.end();

Hide html horizontal but not vertical scrollbar

Using wrap=virtual in your HTML form boxes gets rid of the horizontal scrollbar at the bottom of the box:

  <textarea name= "enquiry" rows="4" cols="30" wrap="virtual"></textarea>

See example here : http://jsbin.com/opube3/2 (Tested on FF and IE)

Dynamically access object property using variable

I asked a question that kinda duplicated on this topic a while back, and after excessive research, and seeing a lot of information missing that should be here, I feel I have something valuable to add to this older post.

  • Firstly I want to address that there are several ways to obtain the value of a property and store it in a dynamic Variable. The first most popular, and easiest way IMHO would be:
let properyValue = element.style['enter-a-property'];

however I rarely go this route because it doesn't work on property values assigned via style-sheets. To give you an example, I'll demonstrate with a bit of pseudo code.

 let elem = document.getElementById('someDiv');
 let cssProp = elem.style['width'];

Using the code example above; if the width property of the div element that was stored in the 'elem' variable was styled in a CSS style-sheet, and not styled inside of its HTML tag, you are without a doubt going to get a return value of undefined stored inside of the cssProp variable. The undefined value occurs because in-order to get the correct value, the code written inside a CSS Style-Sheet needs to be computed in-order to get the value, therefore; you must use a method that will compute the value of the property who's value lies within the style-sheet.

  • Henceforth the getComputedStyle() method!
function getCssProp(){
  let ele = document.getElementById("test");
  let cssProp = window.getComputedStyle(ele,null).getPropertyValue("width");
}

W3Schools getComputedValue Doc This gives a good example, and lets you play with it, however, this link Mozilla CSS getComputedValue doc talks about the getComputedValue function in detail, and should be read by any aspiring developer who isn't totally clear on this subject.

  • As a side note, the getComputedValue method only gets, it does not set. This, obviously is a major downside, however there is a method that gets from CSS style-sheets, as well as sets values, though it is not standard Javascript. The JQuery method...
$(selector).css(property,value)

...does get, and does set. It is what I use, the only downside is you got to know JQuery, but this is honestly one of the very many good reasons that every Javascript Developer should learn JQuery, it just makes life easy, and offers methods, like this one, which is not available with standard Javascript. Hope this helps someone!!!

How to get screen width without (minus) scrollbar?

None of these solutions worked for me, however I was able to fix it by taking the width and subtracting the width of the scroll bar. I'm not sure how cross-browser compatible this is.

How do I trim leading/trailing whitespace in a standard way?

The easiest way to skip leading spaces in a string is, imho,

#include <stdio.h>

int main()
{
char *foo="     teststring      ";
char *bar;
sscanf(foo,"%s",bar);
printf("String is >%s<\n",bar);
    return 0;
}

How do you convert an entire directory with ffmpeg?

Another simple solution that hasn't been suggested yet would be to use xargs:

ls *.avi | xargs -i -n1 ffmpeg -i {} "{}.mp4"

One minor pitfall is the awkward naming of output files (e.g. input.avi.mp4). A possible workaround for this might be:

ls *.avi | xargs -i -n1 bash -c "i={}; ffmpeg -i {} "\${i%.*}.mp4""

ASP.NET MVC 3 - redirect to another action

You have to write this code instead of return View(); :

return RedirectToAction("ActionName", "ControllerName");

Comparing two columns, and returning a specific adjacent cell in Excel

I would advise you to swap B and C columns for the reason that I will explain. Then in D2 type: =VLOOKUP(A2, B2:C4, 2, FALSE)

Finally, copy the formula for the remaining cells.

Explanation: VLOOKUP will first find the value of A2 in the range B2 to C4 (second argument). NOTE: VLOOKUP always searches the first column in this range. This is the reason why you have to swap the two columns before doing anything.

Once the exact match is found, it will return the value in the adjacent cell (third argument).

This means that, if you put 1 as the third argument, the function will return the value in the first column of the range (which will be the same value you were looking for). If you put 2, it will return the value from the second column in the range (the value in the adjacent cell-RIGHT SIDE of the found value).

FALSE indicates that you are finding the exact match. If you put TRUE, you will be searching for the approximate match.

How Best to Compare Two Collections in Java and Act on Them?

I think the easiest way to do that is by using apache collections api - CollectionUtils.subtract(list1,list2) as long the lists are of the same type.

Which characters need to be escaped in HTML?

If you're inserting text content in your document in a location where text content is expected1, you typically only need to escape the same characters as you would in XML. Inside of an element, this just includes the entity escape ampersand & and the element delimiter less-than and greater-than signs < >:

& becomes &amp;
< becomes &lt;
> becomes &gt;

Inside of attribute values you must also escape the quote character you're using:

" becomes &quot;
' becomes &#39;

In some cases it may be safe to skip escaping some of these characters, but I encourage you to escape all five in all cases to reduce the chance of making a mistake.

If your document encoding does not support all of the characters that you're using, such as if you're trying to use emoji in an ASCII-encoded document, you also need to escape those. Most documents these days are encoded using the fully Unicode-supporting UTF-8 encoding where this won't be necessary.

In general, you should not escape spaces as &nbsp;. &nbsp; is not a normal space, it's a non-breaking space. You can use these instead of normal spaces to prevent a line break from being inserted between two words, or to insert          extra        space       without it being automatically collapsed, but this is usually a rare case. Don't do this unless you have a design constraint that requires it.


1 By "a location where text content is expected", I mean inside of an element or quoted attribute value where normal parsing rules apply. For example: <p>HERE</p> or <p title="HERE">...</p>. What I wrote above does not apply to content that has special parsing rules or meaning, such as inside of a script or style tag, or as an element or attribute name. For example: <NOT-HERE>...</NOT-HERE>, <script>NOT-HERE</script>, <style>NOT-HERE</style>, or <p NOT-HERE="...">...</p>.

In these contexts, the rules are more complicated and it's much easier to introduce a security vulnerability. I strongly discourage you from ever inserting dynamic content in any of these locations. I have seen teams of competent security-aware developers introduce vulnerabilities by assuming that they had encoded these values correctly, but missing an edge case. There's usually a safer alternative, such as putting the dynamic value in an attribute and then handling it with JavaScript.

If you must, please read the Open Web Application Security Project's XSS Prevention Rules to help understand some of the concerns you will need to keep in mind.

String index out of range: 4

You are using the wrong iteration counter, replace inp.charAt(i) with inp.charAt(j).

Notify ObservableCollection when Item changes

The spot you have commented as // Code to trig on item change... will only trigger when the collection object gets changed, such as when it gets set to a new object, or set to null.

With your current implementation of TrulyObservableCollection, to handle the property changed events of your collection, register something to the CollectionChanged event of MyItemsSource

public MyViewModel()
{
    MyItemsSource = new TrulyObservableCollection<MyType>();
    MyItemsSource.CollectionChanged += MyItemsSource_CollectionChanged;

    MyItemsSource.Add(new MyType() { MyProperty = false });
    MyItemsSource.Add(new MyType() { MyProperty = true});
    MyItemsSource.Add(new MyType() { MyProperty = false });
}


void MyItemsSource_CollectionChanged(object sender, NotifyCollectionChangedEventArgs e)
{
    // Handle here
}

Personally I really don't like this implementation. You are raising a CollectionChanged event that says the entire collection has been reset, anytime a property changes. Sure it'll make the UI update anytime an item in the collection changes, but I see that being bad on performance, and it doesn't seem to have a way to identify what property changed, which is one of the key pieces of information I usually need when doing something on PropertyChanged.

I prefer using a regular ObservableCollection and just hooking up the PropertyChanged events to it's items on CollectionChanged. Providing your UI is bound correctly to the items in the ObservableCollection, you shouldn't need to tell the UI to update when a property on an item in the collection changes.

public MyViewModel()
{
    MyItemsSource = new ObservableCollection<MyType>();
    MyItemsSource.CollectionChanged += MyItemsSource_CollectionChanged;

    MyItemsSource.Add(new MyType() { MyProperty = false });
    MyItemsSource.Add(new MyType() { MyProperty = true});
    MyItemsSource.Add(new MyType() { MyProperty = false });
}

void MyItemsSource_CollectionChanged(object sender, NotifyCollectionChangedEventArgs e)
{
    if (e.NewItems != null)
        foreach(MyType item in e.NewItems)
            item.PropertyChanged += MyType_PropertyChanged;

    if (e.OldItems != null)
        foreach(MyType item in e.OldItems)
            item.PropertyChanged -= MyType_PropertyChanged;
}

void MyType_PropertyChanged(object sender, PropertyChangedEventArgs e)
{
    if (e.PropertyName == "MyProperty")
        DoWork();
}

Run a JAR file from the command line and specify classpath

When you specify -jar then the -cp parameter will be ignored.

From the documentation:

When you use this option, the JAR file is the source of all user classes, and other user class path settings are ignored.

You also cannot "include" needed jar files into another jar file (you would need to extract their contents and put the .class files into your jar file)

You have two options:

  1. include all jar files from the lib directory into the manifest (you can use relative paths there)
  2. Specify everything (including your jar) on the commandline using -cp:
    java -cp MyJar.jar:lib/* com.somepackage.subpackage.Main

Deserialize JSON string to c# object

This may be useful:

var serializer = new JavaScriptSerializer();
dynamic jsonObject = serializer.Deserialize<dynamic>(json);

Where "json" is the string that contains the JSON values. Then to retrieve the values from the jsonObject you may use

myProperty = Convert.MyPropertyType(jsonObject["myProperty"]);

Changing MyPropertyType to the proper type (ToInt32, ToString, ToBoolean, etc).

Using subprocess to run Python script on Windows

For example, to execute following with command prompt or BATCH file we can use this:

C:\Python27\python.exe "C:\Program files(x86)\dev_appserver.py" --host 0.0.0.0 --post 8080 "C:\blabla\"

Same thing to do with Python, we can do this:

subprocess.Popen(['C:/Python27/python.exe', 'C:\\Program files(x86)\\dev_appserver.py', '--host', '0.0.0.0', '--port', '8080', 'C:\\blabla'], shell=True)

or

subprocess.Popen(['C:/Python27/python.exe', 'C:/Program files(x86)/dev_appserver.py', '--host', '0.0.0.0', '--port', '8080', 'C:/blabla'], shell=True)

When is it practical to use Depth-First Search (DFS) vs Breadth-First Search (BFS)?

I think it depends on what problems you are facing.

  1. shortest path on simple graph -> bfs
  2. all possible results -> dfs
  3. search on graph(treat tree, martix as a graph too) -> dfs ....

How can I repeat a character in Bash?

In case that you want to repeat a character n times being n a VARIABLE number of times depending on, say, the length of a string you can do:

#!/bin/bash
vari='AB'
n=$(expr 10 - length $vari)
echo 'vari equals.............................: '$vari
echo 'Up to 10 positions I must fill with.....: '$n' equal signs'
echo $vari$(perl -E 'say "=" x '$n)

It displays:

vari equals.............................: AB  
Up to 10 positions I must fill with.....: 8 equal signs  
AB========  

Python 3 sort a dict by its values

To sort a dictionary and keep it functioning as a dictionary afterwards, you could use OrderedDict from the standard library.

If that's not what you need, then I encourage you to reconsider the sort functions that leave you with a list of tuples. What output did you want, if not an ordered list of key-value pairs (tuples)?

How to pass macro definition from "make" command line arguments (-D) to C source code?

Just use a specific variable for that.

$ cat Makefile 
all:
    echo foo | gcc $(USER_DEFINES) -E -xc - 

$ make USER_DEFINES="-Dfoo=one"
echo foo | gcc -Dfoo=one -E -xc - 
...
one

$ make USER_DEFINES="-Dfoo=bar"
echo foo | gcc -Dfoo=bar -E -xc - 
...
bar

$ make 
echo foo | gcc  -E -xc - 
...
foo

HRESULT: 0x80040154 (REGDB_E_CLASSNOTREG))

Just looking at the message it sounds like one or more of the components that you reference, or one or more of their dependencies is not registered properly.

If you know which component it is you can use regsvr32.exe to register it, just open a command prompt, go to the directory where the component is and type regsvr32 filename.dll (assuming it's a dll), if it works, try to run the code again otherwise come back here with the error.

If you don't know which component it is, try re-installing/repairing the GIS software (I assume you've installed some GIS software that includes the component you're trying to use).

Disable Chrome strict MIME type checking

Another solution when a file pretends another extension

I use php inside of var.js file with this .htaccess.

<Files var.js>
    AddType application/x-httpd-php .js
</Files>

Then I write php code in the .js file

<?php
// This is a `.js` file but works with php
echo "var js_variable = '$php_variable';";

When I got the MIME type warning on Chrome, I fixed it by adding a Content-Type header line in the .js(but php) file.

<?php
header('Content-Type: application/javascript');        // <- Add this line
// This is a `.js` file but works with php
...

A browser won't execute .js file because apache sends the Content-Type header of the file as application/x-httpd-php that is defined in .htaccess. That's a security reason. But apache won't execute php as far as htaccess commands the impersonation, it's necessary. So we need to overwrite apache's Content-Type header with the php function header(). I guess that apache stops sending its own header when php sends it instead of apache before.

How to show Bootstrap table with sort icon

You could try using FontAwesome. It contains a sort-icon (http://fontawesome.io/icon/sort/).

To do so, you would

  1. need to include fontawesome:

    <link href="//maxcdn.bootstrapcdn.com/font-awesome/4.1.0/css/font-awesome.min.css" rel="stylesheet">
    
  2. and then simply use the fontawesome-icon instead of the default-bootstrap-icons in your th's:

    <th><b>#</b> <i class="fa fa-fw fa-sort"></i></th>
    

Hope that helps.

Picasso v/s Imageloader v/s Fresco vs Glide

Fresco sources | off site
(-)

  • Huge size of library
  • No Callback with View, Bitmap parameters
  • SimpleDraweeView doesn't support wrap_content
  • Huge size of cache
    (+)
  • Pretty fast image loader (for small && medium images)
  • A lot of functionality(streaming, drawing tools, memory management, etc)
  • Possibility to setup directly in xml (for example round corners)
  • GIF support
  • WebP and Animated Webp support


Picasso sources | off site
(-)

  • Slow loading big images from internet into ListView
    (+)
  • Tinny size of library
  • Small size of cache
  • Simple to use
  • UI does not freeze
  • WebP support


Glide sources

(-)

  • Big size of library
    (+)
  • Tinny size of cache
  • Simple to use
  • GIF support
  • WebP support
  • Fast loading big images from internet into ListView
  • UI does not freeze
  • BitmapPool to re-use memory and thus lesser GC events


Universal Image Loader sources

(-)

  • Limited functionality (limited image processing)
  • Project support has stopped since 27.11.2015
    (+)
  • Tinny size of library
  • Simple to use

Tested by me on SGS2 (Android 4.1) (WiFi 8.43 Mbps)
Official versions for Java, not for Xamarin!
October 19 2015

I prefer to use Glide.
Read more here.
How to write cache to External Storage (SD Card) with Glide.

JsonParseException : Illegal unquoted character ((CTRL-CHAR, code 10)

This error occurs when you are sending JSON data to server. Maybe in your string you are trying to add new line character by using /n.

If you add / before /n, it should work, you need to escape new line character.

"Hello there //n start coding"

The result should be as following

Hello there
start coding

How to create a custom-shaped bitmap marker with Android map API v2

I hope it still not too late to share my solution. Before that, you can follow the tutorial as stated in Android Developer documentation. To achieve this, you need to use Cluster Manager with defaultRenderer.

  1. Create an object that implements ClusterItem

    public class SampleJob implements ClusterItem {
    
    private double latitude;
    private double longitude;
    
    //Create constructor, getter and setter here
    
    @Override
    public LatLng getPosition() {
        return new LatLng(latitude, longitude);
    }
    
  2. Create a default renderer class. This is the class that do all the job (inflating custom marker/cluster with your own style). I am using Universal image loader to do the downloading and caching the image.

    public class JobRenderer extends DefaultClusterRenderer< SampleJob > {
    
    private final IconGenerator iconGenerator;
    private final IconGenerator clusterIconGenerator;
    private final ImageView imageView;
    private final ImageView clusterImageView;
    private final int markerWidth;
    private final int markerHeight;
    private final String TAG = "ClusterRenderer";
    private DisplayImageOptions options;
    
    
    public JobRenderer(Context context, GoogleMap map, ClusterManager<SampleJob> clusterManager) {
        super(context, map, clusterManager);
    
        // initialize cluster icon generator
        clusterIconGenerator = new IconGenerator(context.getApplicationContext());
        View clusterView = LayoutInflater.from(context).inflate(R.layout.multi_profile, null);
        clusterIconGenerator.setContentView(clusterView);
        clusterImageView = (ImageView) clusterView.findViewById(R.id.image);
    
        // initialize cluster item icon generator
        iconGenerator = new IconGenerator(context.getApplicationContext());
        imageView = new ImageView(context.getApplicationContext());
        markerWidth = (int) context.getResources().getDimension(R.dimen.custom_profile_image);
        markerHeight = (int) context.getResources().getDimension(R.dimen.custom_profile_image);
        imageView.setLayoutParams(new ViewGroup.LayoutParams(markerWidth, markerHeight));
        int padding = (int) context.getResources().getDimension(R.dimen.custom_profile_padding);
        imageView.setPadding(padding, padding, padding, padding);
        iconGenerator.setContentView(imageView);
    
        options = new DisplayImageOptions.Builder()
                .showImageOnLoading(R.drawable.circle_icon_logo)
                .showImageForEmptyUri(R.drawable.circle_icon_logo)
                .showImageOnFail(R.drawable.circle_icon_logo)
                .cacheInMemory(false)
                .cacheOnDisk(true)
                .considerExifParams(true)
                .bitmapConfig(Bitmap.Config.RGB_565)
                .build();
    }
    
    @Override
    protected void onBeforeClusterItemRendered(SampleJob job, MarkerOptions markerOptions) {
    
    
        ImageLoader.getInstance().displayImage(job.getJobImageURL(), imageView, options);
        Bitmap icon = iconGenerator.makeIcon(job.getName());
        markerOptions.icon(BitmapDescriptorFactory.fromBitmap(icon)).title(job.getName());
    
    
    }
    
    @Override
    protected void onBeforeClusterRendered(Cluster<SampleJob> cluster, MarkerOptions markerOptions) {
    
        Iterator<Job> iterator = cluster.getItems().iterator();
        ImageLoader.getInstance().displayImage(iterator.next().getJobImageURL(), clusterImageView, options);
        Bitmap icon = clusterIconGenerator.makeIcon(iterator.next().getName());
        markerOptions.icon(BitmapDescriptorFactory.fromBitmap(icon));
    }
    
    @Override
    protected boolean shouldRenderAsCluster(Cluster cluster) {
        return cluster.getSize() > 1;
    }
    
  3. Apply cluster manager in your activity/fragment class.

    public class SampleActivity extends AppCompatActivity implements OnMapReadyCallback {
    
    private ClusterManager<SampleJob> mClusterManager;
    private GoogleMap mMap;
    private ArrayList<SampleJob> jobs = new ArrayList<SampleJob>();
    
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_landing);
    
        SupportMapFragment mapFragment = (SupportMapFragment) getSupportFragmentManager()
                .findFragmentById(R.id.map);
        mapFragment.getMapAsync(this);
    }
    
    
    @Override
    public void onMapReady(GoogleMap googleMap) {
        mMap = googleMap;
        mMap.getUiSettings().setMapToolbarEnabled(true);
        mClusterManager = new ClusterManager<SampleJob>(this, mMap);
        mClusterManager.setRenderer(new JobRenderer(this, mMap, mClusterManager));
        mMap.setOnCameraChangeListener(mClusterManager);
        mMap.setOnMarkerClickListener(mClusterManager);
    
        //Assume that we already have arraylist of jobs
    
    
        for(final SampleJob job: jobs){
            mClusterManager.addItem(job);
        }
        mClusterManager.cluster();
    }
    
  4. Result

Result

SQL Network Interfaces, error: 50 - Local Database Runtime error occurred. Cannot create an automatic instance

I have solved above problem Applying below steps

enter image description here

And after you made thses changes, do following changes in your web.config

 <add name="DefaultConnection" connectionString="Data Source=(LocalDb)\v12.0;AttachDbFilename=|DataDirectory|\aspnet-Real-Time-Commenting-20170927122714.mdf;Initial Catalog=aspnet-Real-Time-Commenting-20170927122714;Integrated Security=true" providerName="System.Data.SqlClient" />

How to set Spring profile from system variable?

If you provide your JVM the Spring profile there should be no problems:

java -Dspring.profiles.active=development -jar yourApplication.jar 

Also see Spring-Documentation:

http://docs.spring.io/spring-boot/docs/current/reference/html/howto-properties-and-configuration.html

69.5 Set the active Spring profiles

The Spring Environment has an API for this, but normally you would set a System property (spring.profiles.active) or an OS environment variable (SPRING_PROFILES_ACTIVE). E.g. launch your application with a -D argument (remember to put it before the main class or jar archive):

$ java -jar -Dspring.profiles.active=production demo-0.0.1-SNAPSHOT.jar

In Spring Boot you can also set the active profile in application.properties, e.g.

spring.profiles.active=production

A value set this way is replaced by the System property or environment variable setting, but not by the SpringApplicationBuilder.profiles() method. Thus the latter Java API can be used to augment the profiles without changing the defaults.

See Chapter 25, Profiles in the ‘Spring Boot features’ section for more information.

jQuery get values of checked checkboxes into array

DEMO: http://jsfiddle.net/PBhHK/

$(document).ready(function(){

    var searchIDs = $('input:checked').map(function(){

      return $(this).val();

    });
    console.log(searchIDs.get());

});

Just call get() and you'll have your array as it is written in the specs: http://api.jquery.com/map/

$(':checkbox').map(function() {
      return this.id;
    }).get().join();

What is a "static" function in C?

There are two uses for the keyword static when it comes to functions in C++.

The first is to mark the function as having internal linkage so it cannot be referenced in other translation units. This usage is deprecated in C++. Unnamed namespaces are preferred for this usage.

// inside some .cpp file:

static void foo();    // old "C" way of having internal linkage

// C++ way:
namespace
{
   void this_function_has_internal_linkage()
   {
      // ...
   }
}

The second usage is in the context of a class. If a class has a static member function, that means the function is a member of the class (and has the usual access to other members), but it doesn't need to be invoked through a particular object. In other words, inside that function, there is no "this" pointer.

How do I get the width and height of a HTML5 canvas?

Here's a CodePen that uses canvas.height/width, CSS height/width, and context to correctly render any canvas at any size.

HTML:

<button onclick="render()">Render</button>
<canvas id="myCanvas" height="100" width="100" style="object-fit:contain;"></canvas>

CSS:

canvas {
  width: 400px;
  height: 200px;
  border: 1px solid red;
  display: block;
}

Javascript:

const myCanvas = document.getElementById("myCanvas");
const originalHeight = myCanvas.height;
const originalWidth = myCanvas.width;
render();
function render() {
  let dimensions = getObjectFitSize(
    true,
    myCanvas.clientWidth,
    myCanvas.clientHeight,
    myCanvas.width,
    myCanvas.height
  );
  myCanvas.width = dimensions.width;
  myCanvas.height = dimensions.height;

  let ctx = myCanvas.getContext("2d");
  let ratio = Math.min(
    myCanvas.clientWidth / originalWidth,
    myCanvas.clientHeight / originalHeight
  );
  ctx.scale(ratio, ratio); //adjust this!
  ctx.beginPath();
  ctx.arc(50, 50, 50, 0, 2 * Math.PI);
  ctx.stroke();
}

// adapted from: https://www.npmjs.com/package/intrinsic-scale
function getObjectFitSize(
  contains /* true = contain, false = cover */,
  containerWidth,
  containerHeight,
  width,
  height
) {
  var doRatio = width / height;
  var cRatio = containerWidth / containerHeight;
  var targetWidth = 0;
  var targetHeight = 0;
  var test = contains ? doRatio > cRatio : doRatio < cRatio;

  if (test) {
    targetWidth = containerWidth;
    targetHeight = targetWidth / doRatio;
  } else {
    targetHeight = containerHeight;
    targetWidth = targetHeight * doRatio;
  }

  return {
    width: targetWidth,
    height: targetHeight,
    x: (containerWidth - targetWidth) / 2,
    y: (containerHeight - targetHeight) / 2
  };
}

Basically, canvas.height/width sets the size of the bitmap you are rendering to. The CSS height/width then scales the bitmap to fit the layout space (often warping it as it scales it). The context can then modify it's scale to draw, using vector operations, at different sizes.

grabbing first row in a mysql query only

To return only one row use LIMIT 1:

SELECT *
FROM tbl_foo
WHERE name = 'sarmen'
LIMIT 1

It doesn't make sense to say 'first row' or 'last row' unless you have an ORDER BY clause. Assuming you add an ORDER BY clause then you can use LIMIT in the following ways:

  • To get the first row use LIMIT 1.
  • To get the 2nd row you can use limit with an offset: LIMIT 1, 1.
  • To get the last row invert the order (change ASC to DESC or vice versa) then use LIMIT 1.

Efficient evaluation of a function at every cell of a NumPy array

When the 2d-array (or nd-array) is C- or F-contiguous, then this task of mapping a function onto a 2d-array is practically the same as the task of mapping a function onto a 1d-array - we just have to view it that way, e.g. via np.ravel(A,'K').

Possible solution for 1d-array have been discussed for example here.

However, when the memory of the 2d-array isn't contiguous, then the situation a little bit more complicated, because one would like to avoid possible cache misses if axis are handled in wrong order.

Numpy has already a machinery in place to process axes in the best possible order. One possibility to use this machinery is np.vectorize. However, numpy's documentation on np.vectorize states that it is "provided primarily for convenience, not for performance" - a slow python function stays a slow python function with the whole associated overhead! Another issue is its huge memory-consumption - see for example this SO-post.

When one wants to have a performance of a C-function but to use numpy's machinery, a good solution is to use numba for creation of ufuncs, for example:

# runtime generated C-function as ufunc
import numba as nb
@nb.vectorize(target="cpu")
def nb_vf(x):
    return x+2*x*x+4*x*x*x

It easily beats np.vectorize but also when the same function would be performed as numpy-array multiplication/addition, i.e.

# numpy-functionality
def f(x):
    return x+2*x*x+4*x*x*x

# python-function as ufunc
import numpy as np
vf=np.vectorize(f)
vf.__name__="vf"

See appendix of this answer for time-measurement-code:

enter image description here

Numba's version (green) is about 100 times faster than the python-function (i.e. np.vectorize), which is not surprising. But it is also about 10 times faster than the numpy-functionality, because numbas version doesn't need intermediate arrays and thus uses cache more efficiently.


While numba's ufunc approach is a good trade-off between usability and performance, it is still not the best we can do. Yet there is no silver bullet or an approach best for any task - one has to understand what are the limitation and how they can be mitigated.

For example, for transcendental functions (e.g. exp, sin, cos) numba doesn't provide any advantages over numpy's np.exp (there are no temporary arrays created - the main source of the speed-up). However, my Anaconda installation utilizes Intel's VML for vectors bigger than 8192 - it just cannot do it if memory is not contiguous. So it might be better to copy the elements to a contiguous memory in order to be able to use Intel's VML:

import numba as nb
@nb.vectorize(target="cpu")
def nb_vexp(x):
    return np.exp(x)

def np_copy_exp(x):
    copy = np.ravel(x, 'K')
    return np.exp(copy).reshape(x.shape) 

For the fairness of the comparison, I have switched off VML's parallelization (see code in the appendix):

enter image description here

As one can see, once VML kicks in, the overhead of copying is more than compensated. Yet once data becomes too big for L3 cache, the advantage is minimal as task becomes once again memory-bandwidth-bound.

On the other hand, numba could use Intel's SVML as well, as explained in this post:

from llvmlite import binding
# set before import
binding.set_option('SVML', '-vector-library=SVML')

import numba as nb

@nb.vectorize(target="cpu")
def nb_vexp_svml(x):
    return np.exp(x)

and using VML with parallelization yields:

enter image description here

numba's version has less overhead, but for some sizes VML beats SVML even despite of the additional copying overhead - which isn't a bit surprise as numba's ufuncs aren't parallelized.


Listings:

A. comparison of polynomial function:

import perfplot
perfplot.show(
    setup=lambda n: np.random.rand(n,n)[::2,::2],
    n_range=[2**k for k in range(0,12)],
    kernels=[
        f,
        vf, 
        nb_vf
        ],
    logx=True,
    logy=True,
    xlabel='len(x)'
    ) 

B. comparison of exp:

import perfplot
import numexpr as ne # using ne is the easiest way to set vml_num_threads
ne.set_vml_num_threads(1)
perfplot.show(
    setup=lambda n: np.random.rand(n,n)[::2,::2],
    n_range=[2**k for k in range(0,12)],
    kernels=[
        nb_vexp, 
        np.exp,
        np_copy_exp,
        ],
    logx=True,
    logy=True,
    xlabel='len(x)',
    )

Check list of words in another string

if any(word in 'some one long two phrase three' for word in list_):

How to define custom configuration variables in rails

Check out this neat gem doing exactly that: https://github.com/mislav/choices

This way your sensitive data won't be exposed in open source projects

Git Push Error: insufficient permission for adding an object to repository database

sudo chmod -R ug+w .;

Basically, .git/objects file does not have write permissions. The above line grants permission to all the files and folders in the directory.

The controller for path was not found or does not implement IController

Embarrassingly, the problem in my case is that I haven't rebuilt the code after adding the controller.

So maybe the first thing to check is that your controller was built and is present (and public) in the binaries. It might save you few minutes of debugging if you're like me.

Get image data url in JavaScript?

shiv / shim / sham

If your image(s) are already loaded (or not), this "tool" may come in handy:

Object.defineProperty
(
    HTMLImageElement.prototype,'toDataURL',
    {enumerable:false,configurable:false,writable:false,value:function(m,q)
    {
        let c=document.createElement('canvas');
        c.width=this.naturalWidth; c.height=this.naturalHeight;
        c.getContext('2d').drawImage(this,0,0); return c.toDataURL(m,q);
    }}
);

.. but why?

This has the advantage of using the "already loaded" image data, so no extra request in needed. Aditionally it lets the end-user (programmer like you) decide the CORS and/or mime-type and quality -OR- you can leave out these arguments/parameters as described in the MDN specification here.

If you have this JS loaded (prior to when it's needed), then converting to dataURL is as simple as:

examples

HTML
<img src="/yo.jpg" onload="console.log(this.toDataURL('image/jpeg'))">
JS
console.log(document.getElementById("someImgID").toDataURL());

GPU fingerprinting

If you are concerned about the "preciseness" of the bits then you can alter this tool to suit your needs as provided by @Kaiido's answer.

How do you create a yes/no boolean field in SQL server?

You can use the data type bit

Values inserted which are greater than 0 will be stored as '1'

Values inserted which are less than 0 will be stored as '1'

Values inserted as '0' will be stored as '0'

This holds true for MS SQL Server 2012 Express

Overflow-x:hidden doesn't prevent content from overflowing in mobile browsers

As @Indigenuity states, this appears to be caused by browsers parsing the <meta name="viewport"> tag.

To solve this problem at the source, try the following:

<meta name="viewport" content="width=device-width, initial-scale=1, minimum-scale=1">.

In my tests this prevents the user from zooming out to view the overflowed content, and as a result prevents panning/scrolling to it as well.

Pass multiple complex objects to a post/put Web API method

Here I found a workaround to pass multiple generic objects (as json) from jquery to a WEB API using JObject, and then cast back to your required specific object type in api controller. This objects provides a concrete type specifically designed for working with JSON.

var combinedObj = {}; 
combinedObj["obj1"] = [your json object 1]; 
combinedObj["obj2"] = [your json object 2];

$http({
       method: 'POST',
       url: 'api/PostGenericObjects/',
       data: JSON.stringify(combinedObj)
    }).then(function successCallback(response) {
         // this callback will be called asynchronously
         // when the response is available
         alert("Saved Successfully !!!");
    }, function errorCallback(response) {
         // called asynchronously if an error occurs
         // or server returns response with an error status.
         alert("Error : " + response.data.ExceptionMessage);
});

and then you can get this object in your controller

using Newtonsoft.Json;
using Newtonsoft.Json.Linq;

public [OBJECT] PostGenericObjects(object obj)
    {
        string[] str = GeneralMethods.UnWrapObjects(obj);
        var item1 = JsonConvert.DeserializeObject<ObjectType1>(str[0]);
        var item2 = JsonConvert.DeserializeObject<ObjectType2>(str[1]);

        return *something*;
    } 

I have made a generic function to unwrap the complex object, so there is no limitation of number of objects while sending and unwrapping. We can even send more than two objects

public class GeneralMethods
{
    public static string[] UnWrapObjects(object obj)
    {
        JObject o = JObject.Parse(obj.ToString());

        string[] str = new string[o.Count];

        for (int i = 0; i < o.Count; i++)
        {
            string var = "obj" + (i + 1).ToString();
            str[i] = o[var].ToString(); 
        }

        return str;
    }

}

I have posted the solution to my blog with a little more description with simpler code to integrate easily.

Pass multiple complex objects to Web API

I hope it would help someone. I would be interested to hear from the experts here regarding the pros and cons of using this methodology.

Escaping HTML strings with jQuery

I've enhanced the mustache.js example adding the escapeHTML() method to the string object.

var __entityMap = {
    "&": "&amp;",
    "<": "&lt;",
    ">": "&gt;",
    '"': '&quot;',
    "'": '&#39;',
    "/": '&#x2F;'
};

String.prototype.escapeHTML = function() {
    return String(this).replace(/[&<>"'\/]/g, function (s) {
        return __entityMap[s];
    });
}

That way it is quite easy to use "Some <text>, more Text&Text".escapeHTML()

How to remove symbols from a string with Python?

One way, using regular expressions:

>>> s = "how much for the maple syrup? $20.99? That's ridiculous!!!"
>>> re.sub(r'[^\w]', ' ', s)
'how much for the maple syrup   20 99  That s ridiculous   '
  • \w will match alphanumeric characters and underscores

  • [^\w] will match anything that's not alphanumeric or underscore

Drawing rotated text on a HTML5 canvas

Here's an HTML5 alternative to homebrew: http://www.rgraph.net/ You might be able to reverse engineer their methods....

You might also consider something like Flot (http://code.google.com/p/flot/) or GCharts: (http://www.maxb.net/scripts/jgcharts/include/demo/#1) It's not quite as cool, but fully backwards compatible and scary easy to implement.

Error Domain=NSURLErrorDomain Code=-1005 "The network connection was lost."

I was hitting this error when passing an NSURLRequest to an NSURLSession without setting the request's HTTPMethod.

NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:urlComponents.URL];

Error Domain=NSURLErrorDomain Code=-1005 "The network connection was lost."

Add the HTTPMethod, though, and the connection works fine

NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:urlComponents.URL];
[request setHTTPMethod:@"PUT"];

APR based Apache Tomcat Native library was not found on the java.library.path?

Download the appropriate APR based tomcat native library for your operating system so that Apache tomcat server can take some advantage of the feature of your OS which is not included by default in tomcat. For windows it will be a .dll file.

I too got the warning while starting the server and you don't have to worry about this if you are testing or developing. This is meant to be on production purposes. After putting the tcnative-1.dll file inside the bin folder of Apache Tomcat 7 following are the output in the stderr file,

Apr 07, 2015 1:14:12 PM org.apache.catalina.core.AprLifecycleListener init
INFO: Loaded APR based Apache Tomcat Native library 1.1.33 using APR version 1.5.1.
Apr 07, 2015 1:14:12 PM org.apache.catalina.core.AprLifecycleListener init
INFO: APR capabilities: IPv6 [true], sendfile [true], accept filters [false], random [true].
Apr 07, 2015 1:14:14 PM org.apache.catalina.core.AprLifecycleListener initializeSSL
INFO: OpenSSL successfully initialized (OpenSSL 1.0.1m 19 Mar 2015)
Apr 07, 2015 1:14:14 PM org.apache.coyote.AbstractProtocol init
INFO: Initializing ProtocolHandler ["http-apr-127.0.0.1"]

How to post object and List using postman

Make sure that you have made the content-type as application/json in header request and Post from body under the raw tab.

{
  "address": "colombo",
  "username": "hesh",
  "password": "123",
  "registetedDate": "2015-4-3",
  "firstname": "hesh",
  "contactNo": "07762",
  "accountNo": "16161",
  "lastName": "jay",
  "arrayObjectName" : [{
    "Id" : 1,
    "Name": "ABC" },
    {
    "Id" : 2,
    "Name" : "XYZ"
  }],
  "intArrayName" : [111,222,333],
  "stringArrayName" : ["a","b","c"]


}

How to run an external program, e.g. notepad, using hyperlink?

Make a batch file and call the bacth file in Window.open. Here how it works

  1. make a file in notepad
  2. write your script : start wmplayer "\dotnet\sc\1234.mp4" /fullscreen
  3. save as : test.bat in \dotnet\sc\test.bat

in html

window.open('file://dotnet/sc/test.bat')

Enjoy..

How to resolve 'npm should be run outside of the node repl, in your normal shell'

You must get directory right path of program(node.js in program files).

such as

enter image description here

and use "npm install -g phonegap"

Encrypt Password in Configuration Files?

A simple way of doing this is to use Password Based Encryption in Java. This allows you to encrypt and decrypt a text by using a password.

This basically means initializing a javax.crypto.Cipher with algorithm "AES/CBC/PKCS5Padding" and getting a key from javax.crypto.SecretKeyFactory with the "PBKDF2WithHmacSHA512" algorithm.

Here is a code example (updated to replace the less secure MD5-based variant):

import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.security.AlgorithmParameters;
import java.security.GeneralSecurityException;
import java.security.NoSuchAlgorithmException;
import java.security.spec.InvalidKeySpecException;
import java.util.Base64;
import javax.crypto.Cipher;
import javax.crypto.SecretKey;
import javax.crypto.SecretKeyFactory;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.PBEKeySpec;
import javax.crypto.spec.SecretKeySpec;

public class ProtectedConfigFile {

    public static void main(String[] args) throws Exception {
        String password = System.getProperty("password");
        if (password == null) {
            throw new IllegalArgumentException("Run with -Dpassword=<password>");
        }

        // The salt (probably) can be stored along with the encrypted data
        byte[] salt = new String("12345678").getBytes();

        // Decreasing this speeds down startup time and can be useful during testing, but it also makes it easier for brute force attackers
        int iterationCount = 40000;
        // Other values give me java.security.InvalidKeyException: Illegal key size or default parameters
        int keyLength = 128;
        SecretKeySpec key = createSecretKey(password.toCharArray(),
                salt, iterationCount, keyLength);

        String originalPassword = "secret";
        System.out.println("Original password: " + originalPassword);
        String encryptedPassword = encrypt(originalPassword, key);
        System.out.println("Encrypted password: " + encryptedPassword);
        String decryptedPassword = decrypt(encryptedPassword, key);
        System.out.println("Decrypted password: " + decryptedPassword);
    }

    private static SecretKeySpec createSecretKey(char[] password, byte[] salt, int iterationCount, int keyLength) throws NoSuchAlgorithmException, InvalidKeySpecException {
        SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("PBKDF2WithHmacSHA512");
        PBEKeySpec keySpec = new PBEKeySpec(password, salt, iterationCount, keyLength);
        SecretKey keyTmp = keyFactory.generateSecret(keySpec);
        return new SecretKeySpec(keyTmp.getEncoded(), "AES");
    }

    private static String encrypt(String property, SecretKeySpec key) throws GeneralSecurityException, UnsupportedEncodingException {
        Cipher pbeCipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
        pbeCipher.init(Cipher.ENCRYPT_MODE, key);
        AlgorithmParameters parameters = pbeCipher.getParameters();
        IvParameterSpec ivParameterSpec = parameters.getParameterSpec(IvParameterSpec.class);
        byte[] cryptoText = pbeCipher.doFinal(property.getBytes("UTF-8"));
        byte[] iv = ivParameterSpec.getIV();
        return base64Encode(iv) + ":" + base64Encode(cryptoText);
    }

    private static String base64Encode(byte[] bytes) {
        return Base64.getEncoder().encodeToString(bytes);
    }

    private static String decrypt(String string, SecretKeySpec key) throws GeneralSecurityException, IOException {
        String iv = string.split(":")[0];
        String property = string.split(":")[1];
        Cipher pbeCipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
        pbeCipher.init(Cipher.DECRYPT_MODE, key, new IvParameterSpec(base64Decode(iv)));
        return new String(pbeCipher.doFinal(base64Decode(property)), "UTF-8");
    }

    private static byte[] base64Decode(String property) throws IOException {
        return Base64.getDecoder().decode(property);
    }
}

One problem remains: Where should you store the password that you use to encrypt the passwords? You can store it in the source file and obfuscate it, but it's not too hard to find it again. Alternatively, you can give it as a system property when you start the Java process (-DpropertyProtectionPassword=...).

The same issue remains if you use the KeyStore, which also is protected by a password. Basically, you will need to have one master password somewhere, and it's pretty hard to protect.

Navigation Controller Push View Controller

This is working perfect:

PD: Remember to import the destination VC:

#import "DestinationVCName.h"

    - (IBAction)NameOfTheAction:(id)sender 
{
       DestinationVCName *destinationvcname = [self.storyboard instantiateViewControllerWithIdentifier:@"DestinationVCName"];
    [self presentViewController:destinationvcname animated:YES completion:nil];
}

How do I keep CSS floats in one line?

Are you sure that floated block-level elements are the best solution to this problem?

Often with CSS difficulties in my experience it turns out that the reason I can't see a way of doing the thing I want is that I have got caught in a tunnel-vision with regard to my markup ( thinking "how can I make these elements do this?" ) rather than going back and looking at what exactly it is I need to achieve and maybe reworking my html slightly to facilitate that.

Mongoose, Select a specific field with find

Exclude

Below code will retrieve all fields other than password within each document:

const users = await UserModel.find({}, {
  password: 0 
});
console.log(users);

Output

[
  {
    "_id": "5dd3fb12b40da214026e0658",
    "email": "[email protected]"
  }
]

Include

Below code will only retrieve email field within each document:

const users = await UserModel.find({}, {
  email: 1
});
console.log(users);

Output

[
  {
    "email": "[email protected]"
  }
]

How to remove focus border (outline) around text/input boxes? (Chrome)

Solution

*:focus {
    outline: 0;
}

PS: Use outline:0 instead of outline:none on focus. It's valid and better practice.

How can I force a hard reload in Chrome for Android

As of 2018, from google help center (tested on Chrome 63) :

  1. tap on the three dots menu ;
  2. choose History > Clear browsing data ;
  3. if needed, choose the time period (above the checklist) ;
  4. uncheck all items but Cached images and files ;
  5. proceed with Clear data and confirm.

As mentioned in another answer, incognito tabs are also of great use for development.

How to create a file in a directory in java?

With Java 7, you can use Path, Paths, and Files:

import java.io.IOException;
import java.nio.file.FileAlreadyExistsException;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;

public class CreateFile {

    public static void main(String[] args) throws IOException {
        Path path = Paths.get("/tmp/foo/bar.txt");

        Files.createDirectories(path.getParent());

        try {
            Files.createFile(path);
        } catch (FileAlreadyExistsException e) {
            System.err.println("already exists: " + e.getMessage());
        }
    }
}

Locate the nginx.conf file my nginx is actually using

which nginx

will give you the path of the nginx being used


EDIT (2017-Jan-18)

Thanks to Will Palmer's comment on this answer, I have added the following...

If you've installed nginx via a package manager such as HomeBrew...

which nginx

may not give you the EXACT path to the nginx being used. You can however find it using

realpath $(which nginx)

and as mentioned by @Daniel Li

you can get configuration of nginx via his method

alternatively you can use this:

nginx -V

Regex pattern for checking if a string starts with a certain substring?

You could use:

^(mailto|ftp|joe)

But to be honest, StartsWith is perfectly fine to here. You could rewrite it as follows:

string[] prefixes = { "http", "mailto", "joe" };
string s = "joe:bloggs";
bool result = prefixes.Any(prefix => s.StartsWith(prefix));

You could also look at the System.Uri class if you are parsing URIs.

Enable ASP.NET ASMX web service for HTTP POST / GET requests

Try to declare UseHttpGet over your method.

[ScriptMethod(UseHttpGet = true)]
public string HelloWorld()
{
    return "Hello World";
}

Is it possible to run an .exe or .bat file on 'onclick' in HTML

No, that would be a huge security breach. Imagine if someone could run

format c:

whenever you visted their website.

Which tool to build a simple web front-end to my database

I think PHP is a good solution. It's simple to set up, free and there is plenty of documentation on how to create a database management app. Ruby on Rails is faster to code but a bit more difficult to set up.

Generating Random Number In Each Row In Oracle Query

you don’t need a select … from dual, just write:

SELECT t.*, dbms_random.value(1,9) RandomNumber
  FROM myTable t

Difference between h:button and h:commandButton

This is taken from the book - The Complete Reference by Ed Burns & Chris Schalk

h:commandButton vs h:button

What’s the difference between h:commandButton|h:commandLink and h:button|h:link ?

The latter two components were introduced in 2.0 to enable bookmarkable JSF pages, when used in concert with the View Parameters feature.

There are 3 main differences between h:button|h:link and h:commandButton|h:commandLink.

First, h:button|h:link causes the browser to issue an HTTP GET request, while h:commandButton|h:commandLink does a form POST. This means that any components in the page that have values entered by the user, such as text fields, checkboxes, etc., will not automatically be submitted to the server when using h:button|h:link. To cause values to be submitted with h:button|h:link, extra action has to be taken, using the “View Parameters” feature.

The second main difference between the two kinds of components is that h:button|h:link has an outcome attribute to describe where to go next while h:commandButton|h:commandLink uses an action attribute for this purpose. This is because the former does not result in an ActionEvent in the event system, while the latter does.

Finally, and most important to the complete understanding of this feature, the h:button|h:link components cause the navigation system to be asked to derive the outcome during the rendering of the page, and the answer to this question is encoded in the markup of the page. In contrast, the h:commandButton|h:commandLink components cause the navigation system to be asked to derive the outcome on the POSTBACK from the page. This is a difference in timing. Rendering always happens before POSTBACK.

printf %f with only 2 numbers after the decimal point?

You can use something like this:

printf("%.2f", number);

If you need to use the string for something other than printing out, use the NumberFormat class:

NumberFormat formatter = new DecimalFormatter("#.##");
String s = formatter.format(3.14159265); // Creates a string containing "3.14"

Tomcat: java.lang.IllegalArgumentException: Invalid character found in method name. HTTP method names must be tokens

It happened to me when I had a same port used in ssh tunnel SOCKS to run Proxy in 8080 port and my server and my firefox browser proxy was set to that port and got this issue.

Shell script : How to cut part of a string

You can have awk do it all without using cut:

awk '{print substr($7,index($7,"=")+1)}' inputfile

You could use split() instead of substr(index()).

Add padding to HTML text input field

padding-right should work. Example linked.

http://jsfiddle.net/8Ged8/

Can you "compile" PHP code and upload a binary-ish file, which will just be run by the byte code interpreter?

The short answer is "no".

The current implementation of PHP is that of an interpreted language. You can argue the theoretical aspects of the fact that any language can technically be interpreted or compiled, but as it stands, the current implementations are such that PHP code requires an interpreter to run, and the interpreter manages the executing environment.

To answer your question about uploading pre-compiled PHP bytecode, it's probably possible, but you'd have to implement a way for the PHP interpreter to read in such a file and work with it. With existing opcode caches out there already, it doesn't seem like a task that would reap much reward.

What's an Aggregate Root?

Aggregate means collection of something.
root is like top node of tree, from where we can access everything like <html> node in web page document.
Blog Analogy, A user can have many posts and each post can have many comments. so if we fetch any user then it can act as root to access all the related posts and further comments of those posts. These are all together said to be collection or Aggregated

Merging two arrays in .NET

I needed a solution to combine an unknown number of arrays.

Surprised nobody else provided a solution using SelectMany with params.

 private static T[] Combine<T>(params IEnumerable<T>[] items) =>
                    items.SelectMany(i => i).Distinct().ToArray();

If you don't want distinct items just remove distinct.

 public string[] Reds = new [] { "Red", "Crimson", "TrafficLightRed" };
 public string[] Greens = new [] { "Green", "LimeGreen" };
 public string[] Blues = new [] { "Blue", "SkyBlue", "Navy" };

 public string[] Colors = Combine(Reds, Greens, Blues);

Note: There is definitely no guarantee of ordering when using distinct.

How to resolve the "EVP_DecryptFInal_ex: bad decrypt" during file decryption

I think the Key and IV used for encryption using command line and decryption using your program are not same.

Please note that when you use the "-k" (different from "-K"), the input given is considered as a password from which the key is derived. Generally in this case, there is no need for the "-iv" option as both key and password will be derived from the input given with "-k" option.

It is not clear from your question, how you are ensuring that the Key and IV are same between encryption and decryption.

In my suggestion, better use "-K" and "-iv" option to explicitly specify the Key and IV during encryption and use the same for decryption. If you need to use "-k", then use the "-p" option to print the key and iv used for encryption and use the same in your decryption program.

More details can be obtained at https://www.openssl.org/docs/manmaster/apps/enc.html

Why extend the Android Application class?

Offhand, I can't think of a real scenario in which extending Application is either preferable to another approach or necessary to accomplish something. If you have an expensive, frequently used object you can initialize it in an IntentService when you detect that the object isn't currently present. Application itself runs on the UI thread, while IntentService runs on its own thread.

I prefer to pass data from Activity to Activity with explicit Intents, or use SharedPreferences. There are also ways to pass data from a Fragment to its parent Activity using interfaces.

How to fill Matrix with zeros in OpenCV?

Because the last parameter is optional and also the data pointer should point somewhere appropriate:

//inline Mat::Mat(int _rows, int _cols, int _type, void* _data, size_t _step)
double mydata[1];
Mat m1 = Mat(1,1, CV_64F, mydata); 
m1.at<double>(0,0) = 0;

But better do it directly with this template-based constructor:

//inline Mat::Mat(int _rows, int _cols, int _type, const Scalar& _s)
Mat m1 = Mat(1,1, CV_64F, cvScalar(0.));

//or even
Mat m1 = Mat(1,1, CV_64F, double(0));

How to compare each item in a list with the rest, only once?

Your solution is correct, but your outer loop is still longer than needed. You don't need to compare the last element with anything else because it's been already compared with all the others in the previous iterations. Your inner loop still prevents that, but since we're talking about collision detection you can save the unnecessary check.

Using the same language you used to illustrate your algorithm, you'd come with something like this:

for (int i = 0, i < mylist.size() - 1; ++i)
    for (int j = i + 1, j < mylist.size(); --j)
        compare(mylist[i], mylist[j])

compareTo with primitives -> Integer / int

If you are using java 8, you can create Comparator by this method:

Comparator.comparingInt(i -> i);

if you would like to compare with reversed order:

Comparator.comparingInt(i -> -i);

?: ?? Operators Instead Of IF|ELSE

Refering to ?: Operator (C# Reference)

The conditional operator (?:) returns one of two values depending on the value of a Boolean expression. Following is the syntax for the conditional operator.

Refering to ?? Operator (C# Reference)

The ?? operator is called the null-coalescing operator and is used to define a default value for a nullable value types as well as reference types. It returns the left-hand operand if it is not null; otherwise it returns the right operand.

That means:

[Part 1]

return source ?? String.Empty;

[Part 2] is not applicable ...

error: expected declaration or statement at end of input in c

Normally that error occurs when a } was missed somewhere in the code, for example:

void mi_start_curr_serv(void){
    #if 0
    //stmt
    #endif

would fail with this error due to the missing } at the end of the function. The code you posted doesn't have this error, so it is likely coming from some other part of your source.

Use dynamic variable names in `dplyr`

Since you are dynamically building a variable name as a character value, it makes more sense to do assignment using standard data.frame indexing which allows for character values for column names. For example:

multipetal <- function(df, n) {
    varname <- paste("petal", n , sep=".")
    df[[varname]] <- with(df, Petal.Width * n)
    df
}

The mutate function makes it very easy to name new columns via named parameters. But that assumes you know the name when you type the command. If you want to dynamically specify the column name, then you need to also build the named argument.


dplyr version >= 1.0

With the latest dplyr version you can use the syntax from the glue package when naming parameters when using :=. So here the {} in the name grab the value by evaluating the expression inside.

multipetal <- function(df, n) {
  mutate(df, "petal.{n}" := Petal.Width * n)
}

dplyr version >= 0.7

dplyr starting with version 0.7 allows you to use := to dynamically assign parameter names. You can write your function as:

# --- dplyr version 0.7+---
multipetal <- function(df, n) {
    varname <- paste("petal", n , sep=".")
    mutate(df, !!varname := Petal.Width * n)
}

For more information, see the documentation available form vignette("programming", "dplyr").


dplyr (>=0.3 & <0.7)

Slightly earlier version of dplyr (>=0.3 <0.7), encouraged the use of "standard evaluation" alternatives to many of the functions. See the Non-standard evaluation vignette for more information (vignette("nse")).

So here, the answer is to use mutate_() rather than mutate() and do:

# --- dplyr version 0.3-0.5---
multipetal <- function(df, n) {
    varname <- paste("petal", n , sep=".")
    varval <- lazyeval::interp(~Petal.Width * n, n=n)
    mutate_(df, .dots= setNames(list(varval), varname))
}

dplyr < 0.3

Note this is also possible in older versions of dplyr that existed when the question was originally posed. It requires careful use of quote and setName:

# --- dplyr versions < 0.3 ---
multipetal <- function(df, n) {
    varname <- paste("petal", n , sep=".")
    pp <- c(quote(df), setNames(list(quote(Petal.Width * n)), varname))
    do.call("mutate", pp)
}

How to merge a specific commit in Git

You can use git cherry-pick to apply a single commit by itself to your current branch.

Example: git cherry-pick d42c389f

restart mysql server on windows 7

First try:

net stop MySQL   
net start MySQL

If that does not work, try using the windows interface:

Start > Control Panel > System and Security > Administrative Tools > Services

Look for your version of MySQL (In my case - MySQL55), highlight and click the green start arrow. The status should change to "Started"

Open a folder using Process.Start

Strange.

If it can't find explorer.exe, you should get an exception. If it can't find the folder, it should still open some folder (eg my Documents)

You say another copy of Explorer appears in the taskmanager, but you can't see it.

Is it possible that it is opening offscreen (ie another monitor)?

Or are you by any chance doing this in a non-interactive service?

How to run PyCharm in Ubuntu - "Run in Terminal" or "Run"?

The question is already answered, Updating answer to add the PyCharm bin directory to $PATH var, so that pycharm editor can be opened from anywhere(path) in terminal.

Edit the bashrc file,

nano .bashrc

Add following line at the end of bashrc file

export PATH="<path-to-unpacked-pycharm-installation-directory>/bin:$PATH"

Now you can open pycharm from anywhere in terminal

pycharm.sh

Update only specific fields in a models.Model

Usually, the correct way of updating certain fields in one or more model instances is to use the update() method on the respective queryset. Then you do something like this:

affected_surveys = Survey.objects.filter(
    # restrict your queryset by whatever fits you
    # ...
    ).update(active=True)

This way, you don't need to call save() on your model anymore because it gets saved automatically. Also, the update() method returns the number of survey instances that were affected by your update.

How to clear PermGen space Error in tomcat

To complement Michael's answer, and according to this answer, a safe way to deal with the problem is to use the following arguments:

-XX:+CMSClassUnloadingEnabled -XX:+CMSPermGenSweepingEnabled -XX:+UseConcMarkSweepGC

Change the default base url for axios

  1. Create .env.development, .env.production files if not exists and add there your API endpoint, for example: VUE_APP_API_ENDPOINT ='http://localtest.me:8000'
  2. In main.js file, add this line after imports: axios.defaults.baseURL = process.env.VUE_APP_API_ENDPOINT

And that's it. Axios default base Url is replaced with build mode specific API endpoint. If you need specific baseURL for specific request, do it like this:

this.$axios({ url: 'items', baseURL: 'http://new-url.com' })

What is the best way to manage a user's session in React?

To name a few we can use redux-react-session which is having good API for session management like, initSessionService, refreshFromLocalStorage, checkAuth and many other. It also provide some advanced functionality like Immutable JS.

Alternatively we can leverage react-web-session which provides options like callback and timeout.

Is it possible to run JavaFX applications on iOS, Android or Windows Phone 8?

  1. yes you can run it on iOS and Android (Win8 is not supported!
  2. no deployment as a web-app does not work

ERROR in ./node_modules/css-loader?

try using

npm rebuild node-sass

What does "async: false" do in jQuery.ajax()?

From

https://xhr.spec.whatwg.org/#synchronous-flag

Synchronous XMLHttpRequest outside of workers is in the process of being removed from the web platform as it has detrimental effects to the end user's experience. (This is a long process that takes many years.) Developers must not pass false for the async argument when the JavaScript global environment is a document environment. User agents are strongly encouraged to warn about such usage in developer tools and may experiment with throwing an InvalidAccessError exception when it occurs. The future direction is to only allow XMLHttpRequests in worker threads. The message is intended to be a warning to that effect.

Reverting to a specific commit based on commit id with Git?

I think, bwawok's answer is wrong at some point:

if you do

git reset --soft c14809fa

It will make your local files changed to be like they were then, but leave your history etc. the same.

According to manual: git-reset, "git reset --soft"...

does not touch the index file nor the working tree at all (but resets the head to <commit>, just like all modes do). This leaves all your changed files "Changes to be committed", as git status would put it.

So it will "remove" newer commits from the branch. This means, after looking at your old code, you cannot go to the newest commit in this branch again, easily. So it does the opposide as described by bwawok: Local files are not changed (they look exactly as before "git reset --soft"), but the history is modified (branch is truncated after the specified commit).

The command for bwawok's answer might be:

git checkout <commit>

You can use this to peek at old revision: How did my code look yesterday?

(I know, I should put this in comments to this answer, but stackoverflow does not allow me to do so! My reputation is too low.)

Post request in Laravel - Error - 419 Sorry, your session/ 419 your page has expired

some line of code in app/Exceptions/Handler.php solved my problem.

public function render($request, Exception $exception)
{
    if ($exception instanceof Illuminate\Session\TokenMismatchException) {
        Artisan::call('cache:clear');
        Artisan::call('config:cache');
        return Redirect::back();
    }
    return parent::render($request, $exception);
}

How to append rows in a pandas dataframe in a for loop?

I have created a data frame in a for loop with the help of a temporary empty data frame. Because for every iteration of for loop, a new data frame will be created thereby overwriting the contents of previous iteration.

Hence I need to move the contents of the data frame to the empty data frame that was created already. It's as simple as that. We just need to use .append function as shown below :

temp_df = pd.DataFrame() #Temporary empty dataframe
for sent in Sentences:
    New_df = pd.DataFrame({'words': sent.words}) #Creates a new dataframe and contains tokenized words of input sentences
    temp_df = temp_df.append(New_df, ignore_index=True) #Moving the contents of newly created dataframe to the temporary dataframe

Outside the for loop, you can copy the contents of the temporary data frame into the master data frame and then delete the temporary data frame if you don't need it

How to Check if value exists in a MySQL database

preferred way, using MySQLi extension:

$mysqli = new mysqli(SERVER, DBUSER, DBPASS, DATABASE);
$result = $mysqli->query("SELECT id FROM mytable WHERE city = 'c7'");
if($result->num_rows == 0) {
     // row not found, do stuff...
} else {
    // do other stuff...
}
$mysqli->close();

deprecated:

$result = mysql_query("SELECT id FROM mytable WHERE city = 'c7'");
if(mysql_num_rows($result) == 0) {
     // row not found, do stuff...
} else {
    // do other stuff...
}

How to add local jar files to a Maven project?

Add local jar libraries, their sources and javadoc to a Maven project

If you have pre-compiled jar files with libraries, their sources and javadoc, then you can install them to your local Maven repository like this:

mvn install:install-file
    -Dfile=awesomeapp-1.0.1.jar \
    -DpomFile=awesomeapp-1.0.1.pom \
    -Dsources=awesomeapp-1.0.1-sources.jar \
    -Djavadoc=awesomeapp-1.0.1-javadoc.jar \
    -DgroupId=com.example \
    -DartifactId=awesomeapp \
    -Dversion=1.0.1 \
    -Dpackaging=jar

Then in your project you can use this libraries:

<!-- com.example -->
<dependency>
    <groupId>com.example</groupId>
    <artifactId>awesomeapp</artifactId>
    <version>1.0.1</version>
</dependency>

See: maven-install-plugin usage.


Or you can build these libraries yourself with their sources and javadoc using maven-source-plugin and maven-javadoc-plugin, and then install them.

Example project: library

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0
         http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <url>https://example.com/awesomeapp</url>

    <groupId>com.example</groupId>
    <artifactId>awesomeapp</artifactId>
    <name>awesomeapp</name>
    <version>1.0.1</version>
    <packaging>jar</packaging>

    <properties>
        <java.version>12</java.version>
    </properties>

    <build>
        <finalName>awesomeapp</finalName>
        <defaultGoal>install</defaultGoal>

        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>3.8.1</version>
                <configuration>
                    <source>${java.version}</source>
                    <target>${java.version}</target>
                    <encoding>UTF-8</encoding>
                </configuration>
            </plugin>
            <plugin>
                <inherited>true</inherited>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-source-plugin</artifactId>
                <version>3.2.1</version>
                <executions>
                    <execution>
                        <id>attach-sources</id>
                        <goals><goal>jar</goal></goals>
                    </execution>
                </executions>
            </plugin>
            <plugin>
                <inherited>true</inherited>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-javadoc-plugin</artifactId>
                <version>3.2.0</version>
                <executions>
                    <execution>
                        <id>attach-javadocs</id>
                        <goals><goal>jar</goal></goals>
                    </execution>
                </executions>
            </plugin>
        </plugins>
    </build>
</project>

Execute maven install goal:

mvn install

Check your local Maven repository:

~/.m2/repository/com/example/awesomeapp/1.0.1/
 +- _remote.repositories
 +- awesomeapp-1.0.1.jar
 +- awesomeapp-1.0.1.pom
 +- awesomeapp-1.0.1-javadoc.jar
 +- awesomeapp-1.0.1-sources.jar

Then you can use this library:

<!-- com.example -->
<dependency>
    <groupId>com.example</groupId>
    <artifactId>awesomeapp</artifactId>
    <version>1.0.1</version>
</dependency>

How to print jquery object/array

I was having similar problem and

var dataObj = JSON.parse(data);

console.log(dataObj[0].category); //will return Damskie
console.log(dataObj[1].category); //will return Meskie

This solved my problem. Thanks Selvakumar Arumugam

What is the difference between '@' and '=' in directive scope in AngularJS?

@ and = see other answers.

One gotcha about &
TL;DR;
& gets expression (not only function like in examples in other answers) from a parent, and sets it as a function in the directive, that calls the expression. And this function has the ability to replace any variable (even function name) of expression, by passing an object with the variables.

explained
& is an expression reference, that means if you pass something like <myDirective expr="x==y"></myDirective>
in the directive this expr will be a function, that calls the expression, like:
function expr(){return x == y}.
so in directive's html <button ng-click="expr()"></button> will call the expression. In js of the directive just $scope.expr() will call the expression too.
The expression will be called with $scope.x and $scope.y of the parent.
You have the ability to override the parameters!
If you set them by call, e.g. <button ng-click="expr({x:5})"></button>
then the expression will be called with your parameter x and parent's parameter y.
You can override both.
Now you know, why <button ng-click="functionFromParent({x:5})"></button> works.
Because it just calls the expression of parent (e.g. <myDirective functionFromParent="function1(x)"></myDirective>) and replaces possible values with your specified parameters, in this case x.
it could be:
<myDirective functionFromParent="function1(x) + 5"></myDirective>
or
<myDirective functionFromParent="function1(x) + z"></myDirective>
with child call:
<button ng-click="functionFromParent({x:5, z: 4})"></button>.
or even with function replacement:
<button ng-click="functionFromParent({function1: myfn, x:5, z: 4})"></button>.

it just an expression, does not matter if it is a function, or many functions, or just comparison. And you can replace any variable of this expression.

Examples:
directive template vs called code:
parent has defined $scope.x, $scope.y:
parent template: <myDirective expr="x==y"></myDirective>
<button ng-click="expr()"></button> calls $scope.x==$scope.y
<button ng-click="expr({x: 5})"></button> calls 5 == $scope.y
<button ng-click="expr({x:5, y:6})"></button> calls 5 == 6

parent has defined $scope.function1, $scope.x, $scope.y:
parent template: <myDirective expr="function1(x) + y"></myDirective>

<button ng-click="expr()"></button> calls $scope.function1($scope.x) + $scope.y
<button ng-click="expr({x: 5})"></button> calls $scope.function1(5) + $scope.y
<button ng-click="expr({x:5, y:6})"></button> calls $scope.function1(5) + 6
directive has $scope.myFn as function:
<button ng-click="expr({function1: myFn, x:5, y:6})"></button> calls $scope.myFn(5) + 6

What is a regex to match ONLY an empty string?

^$ -- regex to accept empty string.And it wont match "/n" or "foobar/n" as you mentioned. You could test this regex on https://www.regextester.com/1924.

If you have your existing regex use or(|) in your regex to match empty string. For example /^[A-Za-z0-9&._ ]+$|^$/

Remove json element

if we want to remove one attribute say "firstName" from the array we can use map function along with delete as mentioned above

   var result= [
       {
           "FirstName": "Test1",
           "LastName":  "User",
       },
       {
           "FirstName": "user",
           "LastName":  "user",
       },
       {
           "FirstName": "Ropbert",
           "LastName":  "Jones",
       },
       {
           "FirstName": "hitesh",
           "LastName":  "prajapti",
       }
   ]

result.map( el=>{
    delete el["FirstName"]
})
console.log("OUT",result)

How can I call a WordPress shortcode within a template?

echo do_shortcode('[CONTACT-US-FORM]');

Use this in your template.

Look here for more: Do Shortcode

Set space between divs

You need a gutter between two div gutter can be made as following

margin(gutter) = width - gutter size E.g margin = calc(70% - 2em)

<body bgcolor="gray">
<section id="main">
        <div id="left">
            Something here     
        </div>
        <div id="right">
                Someone there
        </div>
</section>
</body>
<style>
body{
    font-size: 10px;
}

#main div{
    float: left;
    background-color:#ffffff;
    width: calc(50% - 1.5em);
    margin-left: 1.5em;
}
</style>

How to add "required" attribute to mvc razor viewmodel text input editor

I needed the "required" HTML5 atribute, so I did something like this:

<%: Html.TextBoxFor(model => model.Name, new { @required = true })%>

SQL Server - SELECT FROM stored procedure

If 'DATA ACCESS' false,

EXEC sp_serveroption 'SQLSERVERNAME', 'DATA ACCESS', TRUE

after,

SELECT  *  FROM OPENQUERY(SQLSERVERNAME, 'EXEC DBNAME..MyProc @parameters')

it works.

What is the difference between an abstract function and a virtual function?

The answer has been provided a number of times but the the question about when to use each is a design-time decision. I would see it as good practice to try to bundle common method definitions into distinct interfaces and pull them into classes at appropriate abstraction levels. Dumping a common set of abstract and virtual method definitions into a class renders the class unistantiable when it may be best to define a non-abstract class that implements a set of concise interfaces. As always, it depends on what best suits your applications specific needs.

Convert a string to int using sql query

Also be aware that when converting from numeric string ie '56.72' to INT you may come up against a SQL error.

Conversion failed when converting the varchar value '56.72' to data type int.

To get around this just do two converts as follows:

STRING -> NUMERIC -> INT

or

SELECT CAST(CAST (MyVarcharCol AS NUMERIC(19,4)) AS INT)

When copying data from TableA to TableB, the conversion is implicit, so you dont need the second convert (if you are happy rounding down to nearest INT):

INSERT INTO TableB (MyIntCol)
SELECT CAST(MyVarcharCol AS NUMERIC(19,4)) as [MyIntCol]
FROM TableA

How do you right-justify text in an HTML textbox?

Did you try setting the style:

input {
    text-align:right;
}

Just tested, this works fine (in FF3 at least):

<html>
    <head>
        <title>Blah</title>
        <style type="text/css">
        input { text-align:right; }
        </style>
    </head>
    <body>
        <input type="text" value="2">
    </body>
</html>

You'll probably want to throw a class on these inputs, and use that class as the selector. I would shy away from "rightAligned" or something like that. In a class name, you want to describe what the element's function is, not how it should be rendered. "numeric" might be good, or perhaps the business function of the text boxes.

html script src="" triggering redirection with button

your folder name is scripts..

and you are Referencing it like ../script/login.js

Also make sure that script folder is in your project directory

Thanks

Changing project port number in Visual Studio 2013

To specify a port for the ASP.NET Development Server

  • In Solution Explorer, click the name of the application.

  • In the Properties pane, click the down-arrow beside Use dynamic ports and select False from the dropdown list.

  • This will enable editing of the Port number property.

  • In the Properties pane, click the text box beside Port number and
    type in a port number. Click outside of the Properties pane. This
    saves the property settings.

  • Each time you run a file-system Web site within Visual Web Developer, the ASP.NET Development Server will listen on the specified port.

Hope this helps.

RecyclerView vs. ListView

The RecyclerView is a new ViewGroup that is prepared to render any adapter-based view in a similar way. It is supossed to be the successor of ListView and GridView, and it can be found in the latest support-v7 version. The RecyclerView has been developed with extensibility in mind, so it is possible to create any kind of layout you can think of, but not without a little pain-in-the-ass dose.

Answer taken from Antonio leiva

 compile 'com.android.support:recyclerview-v7:27.0.0'

RecyclerView is indeed a powerful view than ListView . For more details you can visit This page.

How to add element into ArrayList in HashMap

#i'm also maintaining insertion order here
Map<Integer,ArrayList> d=new LinkedHashMap<>();
for( int i=0; i<2; i++)
{
int id=s.nextInt();
ArrayList al=new ArrayList<>();
al.add(s.next());  //name
al.add(s.next());  //category
al.add(s.nextInt()); //fee
d.put(id, al);
 }

How to refresh a Page using react-route Link

If you just put '/' in the href it will reload the current window.

_x000D_
_x000D_
<a href="/">
  Reload the page
</a>
_x000D_
_x000D_
_x000D_

How to Logout of an Application Where I Used OAuth2 To Login With Google?

Ouath just makes the Google instance null, hence it you out of Google. Now that's how the architecture is made. Logging out of Google, if you Logout of your app is a dirty work, but can't help if the requirement stipulates the same. Hence add the following to your signOut() function. My project was an Angular 6 app:

document.location.href = "https://www.google.com/accounts/Logout?continue=https://appengine.google.com/_ah/logout?continue=http://localhost:4200";

Here localhost:4200 is the URL of my app. If your login page is xyz.com then input that.

Case insensitive string as HashMap key

One approach is to create a custom subclass of the Apache Commons AbstractHashedMap class, overriding the hash and isEqualKeys methods to perform case insensitive hashing and comparison of keys. (Note - I've never tried this myself ...)

This avoids the overhead of creating new objects each time you need to do a map lookup or update. And the common Map operations should O(1) ... just like a regular HashMap.

And if you are prepared to accept the implementation choices they have made, the Apache Commons CaseInsensitiveMap does the work of customizing / specializing AbstractHashedMap for you.


But if O(logN) get and put operations are acceptable, a TreeMap with a case insensitive string comparator is an option; e.g. using String.CASE_INSENSITIVE_ORDER.

And if you don't mind creating a new temporary String object each time you do a put or get, then Vishal's answer is just fine. (Though, I note that you wouldn't be preserving the original case of the keys if you did that ...)

Trigger change() event when setting <select>'s value with val() function

One thing that I found out (the hard way), is that you should have

$('#selectField').change(function(){
  // some content ...
});

defined BEFORE you are using

$('#selectField').val(10).trigger('change');

or

 $('#selectField').val(10).change();

replace NULL with Blank value or Zero in sql server

Different ways to replace NULL in sql server

Replacing NULL value using:

1. ISNULL() function

2. COALESCE() function

3. CASE Statement

SELECT Name as EmployeeName, ISNULL(Bonus,0) as EmployeeBonus from tblEmployee

SELECT Name as EmployeeName, COALESCE(Bonus, 0) as EmployeeBonus 
FROM tblEmployee

SELECT Name as EmployeeName, CASE WHEN Bonus IS NULL THEN 0 
ELSE Bonus  END as EmployeeBonus 
FROM  tblEmployee

How using try catch for exception handling is best practice

The only time you should worry your users about something that happened in the code is if there is something they can or need to do to avoid the issue. If they can change data on a form, push a button or change a application setting in order to avoid the issue then let them know. But warnings or errors that the user has no ability to avoid just makes them lose confidence in your product.

Exceptions and Logs are for you, the developer, not your end user. Understanding the right thing to do when you catch each exception is far better than just applying some golden rule or rely on an application-wide safety net.

Mindless coding is the ONLY kind of wrong coding. The fact that you feel there is something better that can be done in those situations shows that you are invested in good coding, but avoid trying to stamp some generic rule in these situations and understand the reason for something to throw in the first place and what you can do to recover from it.

Compiling with g++ using multiple cores

You can do this with make - with gnu make it is the -j flag (this will also help on a uniprocessor machine).

For example if you want 4 parallel jobs from make:

make -j 4

You can also run gcc in a pipe with

gcc -pipe

This will pipeline the compile stages, which will also help keep the cores busy.

If you have additional machines available too, you might check out distcc, which will farm compiles out to those as well.

Webdriver Unable to connect to host 127.0.0.1 on port 7055 after 45000 ms

I had a similar issue. Maybe this answer will help you as well.

It looks like you have two different errors going on:

  1. Unable to connect to host 127.0.0.1 on port 7055
  2. Error: no display specified

The reason for the Unable to connect error is that the version of Selenium Server does not know how to work with the newer version of Firefox. You need to download a newer version of the Selenium Server that supports the newer version of Firefox.

The reason for the Error: no display specified error is that Firefox is being launched, but there is no X server (GUI) running on the remote host. You can use X11 forwarding to run Firefox on the remote host, but display it on your local host. On Mac OS X, you will need to download XQuartz in order to use X11 forwarding.

Removing duplicates from a list of lists

Strangely, the answers above removes the 'duplicates' but what if I want to remove the duplicated value also?? The following should be useful and does not create a new object in memory!

def dictRemoveDuplicates(self):
    a=[[1,'somevalue1'],[1,'somevalue2'],[2,'somevalue1'],[3,'somevalue4'],[5,'somevalue5'],[5,'somevalue1'],[5,'somevalue1'],[5,'somevalue8'],[6,'somevalue9'],[6,'somevalue0'],[6,'somevalue1'],[7,'somevalue7']]


print(a)
temp = 0
position = -1
for pageNo, item in a:
    position+=1
    if pageNo != temp:
        temp = pageNo
        continue
    else:
        a[position] = 0
        a[position - 1] = 0
a = [x for x in a if x != 0]         
print(a)

and the o/p is:

[[1, 'somevalue1'], [1, 'somevalue2'], [2, 'somevalue1'], [3, 'somevalue4'], [5, 'somevalue5'], [5, 'somevalue1'], [5, 'somevalue1'], [5, 'somevalue8'], [6, 'somevalue9'], [6, 'somevalue0'], [6, 'somevalue1'], [7, 'somevalue7']]
[[2, 'somevalue1'], [3, 'somevalue4'], [7, 'somevalue7']]

How to fix UITableView separator on iOS 7?

UITableView has a property separatorInset. You can use that to set the insets of the table view separators to zero to let them span the full width of the screen.

[tableView setSeparatorInset:UIEdgeInsetsZero];

Note: If your app is also targeting other iOS versions, you should check for the availability of this property before calling it by doing something like this:

if ([tableView respondsToSelector:@selector(setSeparatorInset:)]) {
    [tableView setSeparatorInset:UIEdgeInsetsZero];
}

How do I POST with multipart form data using fetch?

You're setting the Content-Type to be multipart/form-data, but then using JSON.stringify on the body data, which returns application/json. You have a content type mismatch.

You will need to encode your data as multipart/form-data instead of json. Usually multipart/form-data is used when uploading files, and is a bit more complicated than application/x-www-form-urlencoded (which is the default for HTML forms).

The specification for multipart/form-data can be found in RFC 1867.

For a guide on how to submit that kind of data via javascript, see here.

The basic idea is to use the FormData object (not supported in IE < 10):

async function sendData(url, data) {
  const formData  = new FormData();

  for(const name in data) {
    formData.append(name, data[name]);
  }

  const response = await fetch(url, {
    method: 'POST',
    body: formData
  });

  // ...
}

Per this article make sure not to set the Content-Type header. The browser will set it for you, including the boundary parameter.

How to SELECT in Oracle using a DBLINK located in a different schema?

I don't think it is possible to share a database link between more than one user but not all. They are either private (for one user only) or public (for all users).

A good way around this is to create a view in SCHEMA_B that exposes the table you want to access through the database link. This will also give you good control over who is allowed to select from the database link, as you can control the access to the view.

Do like this:

create database link db_link... as before;
create view mytable_view as select * from mytable@db_link;
grant select on mytable_view to myuser;

react-router getting this.props.location in child components

(Update) V5.1 & Hooks (Requires React >= 16.8)

You can use useHistory, useLocation and useRouteMatch in your component to get match, history and location .

const Child = () => {
  const location = useLocation();
  const history = useHistory();
  const match = useRouteMatch("write-the-url-you-want-to-match-here");

  return (
    <div>{location.pathname}</div>
  )
}

export default Child

(Update) V4 & V5

You can use withRouter HOC in order to inject match, history and location in your component props.

class Child extends React.Component {
  static propTypes = {
    match: PropTypes.object.isRequired,
    location: PropTypes.object.isRequired,
    history: PropTypes.object.isRequired
  }

  render() {
    const { match, location, history } = this.props

    return (
      <div>{location.pathname}</div>
    )
  }
}

export default withRouter(Child)

(Update) V3

You can use withRouter HOC in order to inject router, params, location, routes in your component props.

class Child extends React.Component {

  render() {
    const { router, params, location, routes } = this.props

    return (
      <div>{location.pathname}</div>
    )
  }
}

export default withRouter(Child)

Original answer

If you don't want to use the props, you can use the context as described in React Router documentation

First, you have to set up your childContextTypes and getChildContext

class App extends React.Component{

  getChildContext() {
    return {
      location: this.props.location
    }
  }

  render() {
    return <Child/>;
  }
}

App.childContextTypes = {
    location: React.PropTypes.object
}

Then, you will be able to access to the location object in your child components using the context like this

class Child extends React.Component{

   render() {
     return (
       <div>{this.context.location.pathname}</div>
     )
   }

}

Child.contextTypes = {
    location: React.PropTypes.object
 }

Interface vs Abstract Class (general OO)

i will explain Depth Details of interface and Abstract class.if you know overview about interface and abstract class, then first question arrive in your mind when we should use Interface and when we should use Abstract class. So please check below explanation of Interface and Abstract class.

  1. When we should use Interface?

    if you don't know about implementation just we have requirement specification then we go with Interface

  2. When we should use Abstract Class?

    if you know implementation but not completely (partially implementation) then we go with Abstract class.

    Interface

    every method by default public abstract means interface is 100% pure abstract.

    Abstract

    can have Concrete method and Abstract method, what is Concrete method, which have implementation in Abstract class, An abstract class is a class that is declared abstract—it may or may not include abstract methods.

    Interface

    We cannot declared interface as a private, protected

    Q. Why we are not declaring Interface a private and protected?

    Because by default interface method is public abstract so and so that reason that we are not declaring the interface as private and protected.

    Interface method
    also we cannot declared interface as private,protected,final,static,synchronized,native.....

    i will give the reason: why we are not declaring synchronized method because we cannot create object of interface and synchronize are work on object so and son reason that we are not declaring the synchronized method Transient concept are also not applicable because transient work with synchronized.

    Abstract

    we are happily use with public,private final static.... means no restriction are applicable in abstract.

    Interface

    Variables are declared in Interface as a by default public static final so we are also not declared variable as a private, protected.

    Volatile modifier is also not applicable in interface because interface variable is by default public static final and final variable you cannot change the value once it assign the value into variable and once you declared variable into interface you must to assign the variable.

    And volatile variable is keep on changes so it is opp. to final that is reason we are not use volatile variable in interface.

    Abstract

    Abstract variable no need to declared public static final.

i hope this article is useful.

How to print the value of a Tensor object in TensorFlow?

Based on the answers above, with your particular code snippet you can print the product like this:

import tensorflow as tf
#Initialize the session
sess = tf.InteractiveSession()

matrix1 = tf.constant([[3., 3.]])
matrix2 = tf.constant([[2.],[2.]])
product = tf.matmul(matrix1, matrix2)

#print the product
print(product.eval())

#close the session to release resources
sess.close()

How does database indexing work?

Just think of Database Index as Index of a book.

If you have a book about dogs and you want to find an information about let's say, German Shepherds, you could of course flip through all the pages of the book and find what you are looking for - but this of course is time consuming and not very fast.

Another option is that, you could just go to the Index section of the book and then find what you are looking for by using the Name of the entity you are looking ( in this instance, German Shepherds) and also looking at the page number to quickly find what you are looking for.

In Database, the page number is referred to as a pointer which directs the database to the address on the disk where entity is located. Using the same German Shepherd analogy, we could have something like this (“German Shepherd”, 0x77129) where 0x77129 is the address on the disk where the row data for German Shepherd is stored.

In short, an index is a data structure that stores the values for a specific column in a table so as to speed up query search.

Table scroll with HTML and CSS

Late answer, another idea, but very short.

  1. put the contents of header cells into div
  2. fix the header contents, see CSS
table  { margin-top:  20px; display: inline-block; overflow: auto; }
th div { margin-top: -20px; position: absolute; }

Note that it is possible to display table as inline-block due to anonymous table objects:

"missing" [in HTML table tree structure] elements must be assumed in order for the table model to work. Any table element will automatically generate necessary anonymous table objects around itself.

_x000D_
_x000D_
/* scrolltable rules */_x000D_
table  { margin-top:  20px; display: inline-block; overflow: auto; }_x000D_
th div { margin-top: -20px; position: absolute; }_x000D_
_x000D_
/* design */_x000D_
table { border-collapse: collapse; }_x000D_
tr:nth-child(even) { background: #EEE; }
_x000D_
<table style="height: 150px">_x000D_
  <tr> <th><div>first</div> <th><div>second</div>_x000D_
  <tr> <td>foo <td>bar_x000D_
  <tr> <td>foo foo foo foo foo <td>bar_x000D_
  <tr> <td>foo <td>bar_x000D_
  <tr> <td>foo <td>bar bar bar_x000D_
  <tr> <td>foo <td>bar_x000D_
  <tr> <td>foo <td>bar_x000D_
  <tr> <td>foo <td>bar_x000D_
  <tr> <td>foo <td>bar_x000D_
  <tr> <td>foo <td>bar_x000D_
  <tr> <td>foo <td>bar_x000D_
  <tr> <td>foo <td>bar_x000D_
  <tr> <td>foo <td>bar_x000D_
  <tr> <td>foo <td>bar_x000D_
  <tr> <td>foo <td>bar_x000D_
</table>
_x000D_
_x000D_
_x000D_

How to draw circle by canvas in Android?

public class CircleView extends View {

    private static final String COLOR_HEX = "#E74300";
    private final Paint drawPaint;
    private       float size;

    public CircleView(final Context context, final AttributeSet attrs) {
        super(context, attrs);
        drawPaint = new Paint();
        drawPaint.setColor(Color.parseColor(COLOR_HEX));
        drawPaint.setAntiAlias(true);
        setOnMeasureCallback();
    }

    @Override
    protected void onDraw(final Canvas canvas) {
        super.onDraw(canvas);
        canvas.drawCircle(size, size, size, drawPaint);
    }

    private void setOnMeasureCallback() {
        ViewTreeObserver vto = getViewTreeObserver();
        vto.addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() {
            @Override
            public void onGlobalLayout() {
                removeOnGlobalLayoutListener(this);
                size = getMeasuredWidth() / 2;
            }
        });
    }

    @TargetApi(Build.VERSION_CODES.JELLY_BEAN)
    private void removeOnGlobalLayoutListener(ViewTreeObserver.OnGlobalLayoutListener listener) {
        if (Build.VERSION.SDK_INT < 16) {
            getViewTreeObserver().removeGlobalOnLayoutListener(listener);
        } else {
            getViewTreeObserver().removeOnGlobalLayoutListener(listener);
        }
    }
}

Xml example: will produce a circle of 5dp

 <com.example.CircleView
        android:layout_width="10dp"
        android:layout_height="10dp"/>

Python variables as keys to dict

Try:

to_dict = lambda **k: k
apple = 1
banana = 'f'
carrot = 3
to_dict(apple=apple, banana=banana, carrot=carrot)
#{'apple': 1, 'banana': 'f', 'carrot': 3}

How to parse JSON and access results

Try:

$result = curl_exec($cURL);
$result = json_decode($result,true);

Now you can access MessageID from $result['MessageID'].

As for the database, it's simply using a query like so:

INSERT INTO `tableName`(`Cancelled`,`Queued`,`SMSError`,`SMSIncommingMessage`,`Sent`,`SentDateTime`) VALUES('?','?','?','?','?');

Prepared.

Python: How exactly can you take a string, split it, reverse it and join it back together again?

You mean this?

from string import punctuation, digits

takeout = punctuation + digits

turnthis = "(fjskl) 234 = -345 089 abcdef"
turnthis = turnthis.translate(None, takeout)[::-1]
print turnthis

How to fix error ::Format of the initialization string does not conform to specification starting at index 0::

I had the same error message in my localhost development with my Visual Studio. Note that everything was working when released with Microsoft Release Management (MRM). I fixed my situation by changing the initial value that was a MRM reference.

My App.config initial value was the following:

  <connectionStrings>
    <add name="BDORA" connectionString="__token3__" />
  </connectionStrings>

Locally, the application execution could not interpret the token3 reference to its real value in Tokens.xml. To make it work on my localhost, I had to force the value from token3 in Tokens.xml into the App.config file.

diff current working copy of a file with another branch's committed copy

You're trying to compare your working tree with a particular branch name, so you want this:

git diff master -- foo

Which is from this form of git-diff (see the git-diff manpage)

   git diff [--options] <commit> [--] [<path>...]
       This form is to view the changes you have in your working tree
       relative to the named <commit>. You can use HEAD to compare it with
       the latest commit, or a branch name to compare with the tip of a
       different branch.

FYI, there is also a --cached (aka --staged) option for viewing the diff of what you've staged, rather than everything in your working tree:

   git diff [--options] --cached [<commit>] [--] [<path>...]
       This form is to view the changes you staged for the next commit
       relative to the named <commit>.
       ...
       --staged is a synonym of --cached.

how much memory can be accessed by a 32 bit machine?

No your concepts are not right. And to set it right you need the answer to the question that you incorrectly answered:

What is meant by 32bit or 64 bit machine?

The answer to the question is "something significant in the CPU is 32bit or 64 bit". So the question is what is that something significant? Lot of people say the width of data bus that determine whether the machine is 32bit or 64 bit. But none of the latest 32 bit processors have 32 bit or 64 bit wide data buses. most 32 bit systems will have 36 bit at least to support more RAM. Most 64 bit processors have no more than 48bit wide data bus because that is hell lot of memory already.

So according to me a 32 bit or 64 bit machine is determined by the size of its general purpose registers used in computation or "the natural word size" used by the computer.

Note that a 32 bit OS is a different thing. You can have a 32 bit OS running on 64 bit computer. Additionally, you can have 32 bit application running on 64 bit OS. If you do not understand the difference, post another question.

So the maximum amount of RAM a processor can address is 2^(width of data bus in bits), given that the proper addressing mode is switched on in the processor.

Further note, there is nothing stopping someone to introduce a multiplex between data Bus and memory banks, that will select a bank and then address the RAM (in two steps). This way you can address even more RAM. But that is impractical, and highly inefficient.

Putting a simple if-then-else statement on one line

<execute-test-successful-condition> if <test> else <execute-test-fail-condition>

with your code-snippet it would become,

count = 0 if count == N else N + 1

Custom CSS for <audio> tag?

Besides the box-shadow, transform and border options mentioned in other answers, WebKit browsers currently also obey -webkit-text-fill-color to set the colour of the "time elapsed" numbers, but since there is no way to set their background (which might vary with platform, e.g. inverted high-contrast modes on some operating systems), you would be advised to set -webkit-text-fill-color to the value "initial" if you've used it elsewhere and the audio element is inheriting this, otherwise some users might find those numbers unreadable.

iOS Swift - Get the Current Local Time and Date Timestamp

When we convert a UTC timestamp (2017-11-06 20:15:33 -08:00) into a Date object, the time zone is zeroed out to GMT. For calculating time intervals, this isn't an issue, but it can be for rendering times in the UI.

I favor the RFC3339 format (2017-11-06T20:15:33-08:00) for its universality. The date format in Swift is yyyy-MM-dd'T'HH:mm:ssXXXXX but RFC3339 allows us to take advantage of the ISO8601DateFormatter:

func getDateFromUTC(RFC3339: String) -> Date? {
    let formatter = ISO8601DateFormatter()
    return formatter.date(from: RFC3339)
}

RFC3339 also makes time-zone extraction simple:

func getTimeZoneFromUTC(RFC3339: String) -> TimeZone? {

    switch RFC3339.suffix(6) {

    case "+05:30":
        return TimeZone(identifier: "Asia/Kolkata")

    case "+05:45":
        return TimeZone(identifier: "Asia/Kathmandu")

    default:
        return nil

    }

}

There are 37 or so other time zones we'd have to account for and it's up to you to determine which ones, because there is no definitive list. Some standards count fewer time zones, some more. Most time zones break on the hour, some on the half hour, some on 0:45, some on 0:15.

We can combine the two methods above into something like this:

func getFormattedDateFromUTC(RFC3339: String) -> String? {

    guard let date = getDateFromUTC(RFC3339: RFC3339),
        let timeZone = getTimeZoneFromUTC(RFC3339: RFC3339) else {
            return nil
    }

    let formatter = DateFormatter()
    formatter.dateFormat = "h:mma EEE, MMM d yyyy"
    formatter.amSymbol = "AM"
    formatter.pmSymbol = "PM"
    formatter.timeZone = timeZone // preserve local time zone
    return formatter.string(from: date)

}

And so the string "2018-11-06T17:00:00+05:45", which represents 5:00PM somewhere in Kathmandu, will print 5:00PM Tue, Nov 6 2018, displaying the local time, regardless of where the machine is.

As an aside, I recommend storing dates as strings remotely (including Firestore which has a native date object) because, I think, remote data should agnostic to create as little friction between servers and clients as possible.

Using npm behind corporate proxy .pac

I ran into similar issue and found out that my npm config file ( .npmrc) is having wrong registry entry. commented it out and re ran npm install. it worked.

What does "hashable" mean in Python?

For creating a hashing table from scratch, all the values has to set to "None" and modified once a requirement arises. Hashable objects refers to the modifiable datatypes(Dictionary,lists etc). Sets on the other hand cannot be reinitialized once assigned, so sets are non hashable. Whereas, The variant of set() -- frozenset() -- is hashable.

Update Jenkins from a war file

We run jenkins from the .war file with the following command.

java -Xmx2500M -jar jenkins.war --httpPort=3333 --prefix=/jenkins

You can even run the command from the ~/Downloads directory

SQL multiple column ordering

Multiple column ordering depends on both column's corresponding values: Here is my table example where are two columns named with Alphabets and Numbers and the values in these two columns are asc and desc orders.

enter image description here

Now I perform Order By in these two columns by executing below command:

enter image description here

Now again I insert new values in these two columns, where Alphabet value in ASC order:

enter image description here

and the columns in Example table look like this. Now again perform the same operation:

enter image description here

You can see the values in the first column are in desc order but second column is not in ASC order.

How can I make a DateTimePicker display an empty string?

In case anybody has an issue with setting datetimepicker control to blank during the form load event, and then show the current date as needed, here is an example:

MAKE SURE THAT CustomFormat = " " has same number of spaces (at least one space) in both methods

Private Sub setDateTimePickerBlank(ByVal dateTimePicker As DateTimePicker)    

    dateTimePicker.Visible = True
    dateTimePicker.Format = DateTimePickerFormat.Custom
    dateTimePicker.CustomFormat = "    " 
End Sub


Private Sub dateTimePicker_MouseHover(ByVal sender As Object, ByVal e As 
                    System.EventArgs) Handles dateTimePicker.MouseHover

    Dim dateTimePicker As DateTimePicker = CType(sender, DateTimePicker)
    If dateTimePicker.Text = "    " Then
        dateTimePicker.Text = Format(DateTime.Now, "MM/dd/yyyy")
    End If
End Sub

jQuery: Wait/Delay 1 second without executing code

If you are using ES6 features and you're in an async function, you can effectively halt the code execution for a certain time with this function:

const delay = millis => new Promise((resolve, reject) => {
  setTimeout(_ => resolve(), millis)
});

This is how you use it:

await delay(5000);

It will stall for the requested amount of milliseconds, but only if you're in an async function. Example below:

const myFunction = async function() {
  // first code block ...

  await delay(5000);

  // some more code, executed 5 seconds after the first code block finishes
}

How to style SVG with external CSS?

Your main.css file would only have an effect on the content of the SVG if the SVG file is included inline in the HTML:

https://developer.mozilla.org/en/docs/SVG_In_HTML_Introduction

<html>
  <body>
  <svg version="1.1" id="Layer_1" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" viewBox="0 0 56.69 56.69">
    <g>
      <path d="M28.44......./>
    </g>
  </svg>
</html>

If you want to keep your SVG in files, the CSS needs to be defined inside of the SVG file.

You can do it with a style tag:

http://www.w3.org/TR/SVG/styling.html#StyleElementExample

<!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.1//EN" 
  "http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd">
<svg xmlns="http://www.w3.org/2000/svg" version="1.1"
     width="50px" height="50px" viewBox="0 0 50 50">
  <defs>
    <style type="text/css"><![CDATA[
      .socIcon g {
        fill:red;
      }
    ]]></style>
  </defs>
  <g>
    <path d="M28.44......./>
  </g>
</svg>

You could use a tool on the server side to update the style tag depending on the active style. In ruby you could achieve this with Nokogiri. SVG is just XML. So there are probably many XML libraries available that can probably achieve this.

If you're not able to do that, you will have to just have to use them as though they were PNGs; creating a set for each style, and saving their styles inline.

Default SQL Server Port

For Http Request Default Port number is 80

For Https Default Port Number is 443

For Sql Server Default Port Number is 1433

Fixed positioned div within a relative parent div

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

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

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

div#main {
    width: 60%;
}

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

And a brief picture below describing the layout above:

example layout

How to sort an STL vector?

Overload less than operator, then sort. This is an example I found off the web...

class MyData
{
public:
  int m_iData;
  string m_strSomeOtherData;
  bool operator<(const MyData &rhs) const { return m_iData < rhs.m_iData; }
};

std::sort(myvector.begin(), myvector.end());

Source: here

Measuring the distance between two coordinates in PHP

Here the simple and perfect code for calculating the distance between two latitude and longitude. The following code have been found from here - http://www.codexworld.com/distance-between-two-addresses-google-maps-api-php/

$latitudeFrom = '22.574864';
$longitudeFrom = '88.437915';

$latitudeTo = '22.568662';
$longitudeTo = '88.431918';

//Calculate distance from latitude and longitude
$theta = $longitudeFrom - $longitudeTo;
$dist = sin(deg2rad($latitudeFrom)) * sin(deg2rad($latitudeTo)) +  cos(deg2rad($latitudeFrom)) * cos(deg2rad($latitudeTo)) * cos(deg2rad($theta));
$dist = acos($dist);
$dist = rad2deg($dist);
$miles = $dist * 60 * 1.1515;

$distance = ($miles * 1.609344).' km';

How to have jQuery restrict file types on upload?

Here is a simple code for javascript validation, and after it validates it will clean the input file.

<input type="file" id="image" accept="image/*" onChange="validate(this.value)"/>

function validate(file) {
    var ext = file.split(".");
    ext = ext[ext.length-1].toLowerCase();      
    var arrayExtensions = ["jpg" , "jpeg", "png", "bmp", "gif"];

    if (arrayExtensions.lastIndexOf(ext) == -1) {
        alert("Wrong extension type.");
        $("#image").val("");
    }
}

Declaring a xsl variable and assigning value to it

No, unlike in a lot of other languages, XSLT variables cannot change their values after they are created. You can however, avoid extraneous code with a technique like this:

<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
  <xsl:output method="xml" indent="yes" omit-xml-declaration="yes"/>

  <xsl:variable name="mapping">
    <item key="1" v1="A" v2="B" />
    <item key="2" v1="X" v2="Y" />
  </xsl:variable>
  <xsl:variable name="mappingNode"
                select="document('')//xsl:variable[@name = 'mapping']" />

  <xsl:template match="....">
    <xsl:variable name="testVariable" select="'1'" />

    <xsl:variable name="values" select="$mappingNode/item[@key = $testVariable]" />

    <xsl:variable name="variable1" select="$values/@v1" />
    <xsl:variable name="variable2" select="$values/@v2" />
  </xsl:template>
</xsl:stylesheet>

In fact, once you've got the values variable, you may not even need separate variable1 and variable2 variables. You could just use $values/@v1 and $values/@v2 instead.

Newline character in StringBuilder

For multiple lines the best way I find is to do this:

        IEnumerable<string> lines = new List<string>
        {
            string.Format("{{ line with formatting... {0} }}", id),
            "line 2",
            "line 3"
        };
        StringBuilder sb = new StringBuilder();
        foreach(var line in lines)
            sb.AppendLine(line);

In this way you don't have to clutter the screen with the Environment.NewLine or AppendLine() repeated multiple times. It will also be less error prone than having to remember to type them.

Mean Squared Error in Numpy?

The standard numpy methods for calculation mean squared error (variance) and its square root (standard deviation) are numpy.var() and numpy.std(), see here and here. They apply to matrices and have the same syntax as numpy.mean().

I suppose that the question and the preceding answers might have been posted before these functions became available.

How to add a WiX custom action that happens only on uninstall (via MSI)?

I used Custom Action separately coded in C++ DLL and used the DLL to call appropriate function on Uninstalling using this syntax :

<CustomAction Id="Uninstall" BinaryKey="Dll_Name" 
              DllEntry="Function_Name" Execute="deferred" />

Using the above code block, I was able to run any function defined in C++ DLL on uninstall. FYI, my uninstall function had code regarding Clearing current user data and registry entries.

HTTP status code for update and delete?

Here are some Tips:

DELETE

  • 200 (if you want send some additional data in the Response) or 204 (recommended).

  • 202 Operation deleted has not been committed yet.

  • If there's nothing to delete, use 204 or 404 (DELETE operation is idempotent, delete an already deleted item is operation successful, so you can return 204, but it's true that idempotent doesn't necessarily imply the same response)

Other errors:

  • 400 Bad Request (Malformed syntax or a bad query is strange but possible).
  • 401 Unauthorized Authentication failure
  • 403 Forbidden: Authorization failure or invalid Application ID.
  • 405 Not Allowed. Sure.
  • 409 Resource Conflict can be possible in complex systems.
  • And 501, 502 in case of errors.

PUT

If you're updating an element of a collection

  • 200/204 with the same reasons as DELETE above.
  • 202 if the operation has not been commited yet.

The referenced element doesn't exists:

  • PUT can be 201 (if you created the element because that is your behaviour)

  • 404 If you don't want to create elements via PUT.

  • 400 Bad Request (Malformed syntax or a bad query more common than in case of DELETE).

  • 401 Unauthorized

  • 403 Forbidden: Authentication failure or invalid Application ID.

  • 405 Not Allowed. Sure.

  • 409 Resource Conflict can be possible in complex systems, as in DELETE.

  • 422 Unprocessable entity It helps to distinguish between a "Bad request" (e.g. malformed XML/JSON) and invalid field values

  • And 501, 502 in case of errors.

Android - Pulling SQlite database android device

It is always better if things are automated.That's why I wrote simple python script for copying db file from device using ADB. It saves a lot of development time if you're doing it frequently.

Works only with debuggable apps if device is Not rooted.

Here is link to the gist.

Run it as : python copyandroiddbfile.py

import sys
import subprocess
import re

#/
# Created by @nieldeokar on 25/05/2018.
#/

# 1. Python script which will copy database file of debuggable apps from the android device to your computer using ADB.
# 2. This script ask for PackageName and DatabaseName at runtime.
# 3. You can make it static by passing -d at as command line argument while running script and setting defaults in following way.
# 4. Edit script and change the values of varialbe packageName and dbName to debuggable app package name and database name then
# run script as : python Copydbfileandroid.py -d 

useDefaults = False


def checkIfPackageInstalled(strSelectedDevice) :

    packageName = 'com.nileshdeokar.healthapp.debug'
    dbName = 'healthapp.db'


    if not useDefaults : 
        print('Please enter package name : ')
        packageName = raw_input()

    packageString = 'package:'+packageName

    try:
        adbCheckIfPackageInstalledOutput = subprocess.check_output('adb -s ' + strSelectedDevice + ' shell pm list packages | grep -x '+ packageString, shell=True)
    except subprocess.CalledProcessError as e:
                print "Package not found"
                return


    if packageString.strip() == adbCheckIfPackageInstalledOutput.strip() : 
        if not useDefaults : 
            print('Please enter db name : ')
            dbName = raw_input()

        adbCopyDbString = 'adb -s '+strSelectedDevice + ' -d shell \"run-as '+packageName+' cat /data/data/'+packageName+'/databases/'+ dbName +'\" > '+dbName

        try:
            copyDbOp = subprocess.check_output(adbCopyDbString,shell=True)
        except subprocess.CalledProcessError as e:
                return

        if "is not debuggable" in copyDbOp :
            print packageString + 'is nto debuggable'

        if copyDbOp.strip() == "":
            print 'Successfully copied '+dbName + ' in current directory'

    else :
        print 'Package is not installed on the device'



defaultString = "-d"
if len(sys.argv[1:]) > 0 and sys.argv[1] == defaultString :
        useDefaults = True

listDevicesOutput = subprocess.check_output("adb devices", shell=True)
listDevicesOutput = listDevicesOutput.replace("List of devices attached"," ").replace("\n","").replace("\t","").replace("\n\n","")

numberofDevices = len(re.findall(r'device+', listDevicesOutput))

connectedDevicesArray = listDevicesOutput.split("device")   
del connectedDevicesArray[-1] 


strSelectedDevice = ''
if(numberofDevices > 1) :
    print('Please select the device : \n'),

    for idx, device in enumerate(connectedDevicesArray):
        print idx+1,device

    selectedDevice = raw_input()

    if selectedDevice.isdigit() :
        intSelected = int(selectedDevice)
        if 1 <= intSelected <= len(connectedDevicesArray) :
            print 'Selected device is : ',connectedDevicesArray[intSelected-1]
            checkIfPackageInstalled(connectedDevicesArray[intSelected-1])
        else :
            print 'Please select in range'
    else : 
        print 'Not valid input'

elif numberofDevices == 1 :
    checkIfPackageInstalled(connectedDevicesArray[0])
elif numberofDevices == 0 :
    print("No device is attached")

Compare 2 JSON objects

Simply parsing the JSON and comparing the two objects is not enough because it wouldn't be the exact same object references (but might be the same values).

You need to do a deep equals.

From http://threebit.net/mail-archive/rails-spinoffs/msg06156.html - which seems the use jQuery.

Object.extend(Object, {
   deepEquals: function(o1, o2) {
     var k1 = Object.keys(o1).sort();
     var k2 = Object.keys(o2).sort();
     if (k1.length != k2.length) return false;
     return k1.zip(k2, function(keyPair) {
       if(typeof o1[keyPair[0]] == typeof o2[keyPair[1]] == "object"){
         return deepEquals(o1[keyPair[0]], o2[keyPair[1]])
       } else {
         return o1[keyPair[0]] == o2[keyPair[1]];
       }
     }).all();
   }
});

Usage:

var anObj = JSON.parse(jsonString1);
var anotherObj= JSON.parse(jsonString2);

if (Object.deepEquals(anObj, anotherObj))
   ...

How to play an android notification sound

Set sound to notification channel

        Uri alarmUri = Uri.fromFile(new File(<path>));

        AudioAttributes attributes = new AudioAttributes.Builder()
                .setUsage(AudioAttributes.USAGE_ALARM)
                .build();

        channel.setSound(alarmUri, attributes);

How to perform runtime type checking in Dart?

As others have mentioned, Dart's is operator is the equivalent of Javascript's instanceof operator. However, I haven't found a direct analogue of the typeof operator in Dart.

Thankfully the dart:mirrors reflection API has recently been added to the SDK, and is now available for download in the latest Editor+SDK package. Here's a short demo:

import 'dart:mirrors'; 

getTypeName(dynamic obj) {
  return reflect(obj).type.reflectedType.toString();
}

void main() {
  var val = "\"Dart is dynamically typed (with optional type annotations.)\"";
  if (val is String) {
    print("The value is a String, but I needed "
        "to check with an explicit condition.");
  }
  var typeName = getTypeName(val);
  print("\nThe mirrored type of the value is $typeName.");
}

How to clear browsing history using JavaScript?

As MDN Window.history() describes :

For top-level pages you can see the list of pages in the session history, accessible via the History object, in the browser's dropdowns next to the back and forward buttons.

For security reasons the History object doesn't allow the non-privileged code to access the URLs of other pages in the session history, but it does allow it to navigate the session history.

There is no way to clear the session history or to disable the back/forward navigation from unprivileged code. The closest available solution is the location.replace() method, which replaces the current item of the session history with the provided URL.

So there is no Javascript method to clear the session history, instead, if you want to block navigating back to a certain page, you can use the location.replace() method, and pass the page link as parameter, which will not push the page to the browser's session history list. For example, there are three pages:

a.html:

<!doctype html>
<html>
    <head>
        <title>a.html page</title>
    <meta charset="utf-8">
    </head>
    <body>
         <p>This is <code style="color:red">a.html</code> page ! Go to <a href="b.html">b.html</a> page !</p>        
    </body>
 </html>

b.html:

<!doctype html>
<html>
    <head>
    <title>b.html page</title>
    <meta charset="utf-8">
</head>
<body>
    <p>This is <code style="color:red">b.html</code> page ! Go to <a id="jumper" href="c.html">c.html</a> page !</p>

    <script type="text/javascript">
        var jumper = document.getElementById("jumper");
        jumper.onclick = function(event) {
            var e = event || window.event ;
            if(e.preventDefault) {
                e.preventDefault();
            } else {
                e.returnValue = true ;
            }
            location.replace(this.href);
            jumper = null;
        }
    </script>
</body>

c.html:

<!doctype html>
<html>
<head>
    <title>c.html page</title>
    <meta charset="utf-8">
</head>
<body>
    <p>This is <code style="color:red">c.html</code> page</p>
</body>
</html>

With href link, we can navigate from a.html to b.html to c.html. In b.html, we use the location.replace(c.html) method to navigate from b.html to c.html. Finally, we go to c.html*, and if we click the back button in the browser, we will jump to **a.html.

So this is it! Hope it helps.

Quotation marks inside a string

You can add escaped double quotes like this: String name = "\"john\"";

How do I force a favicon refresh?

This works for Chrome:

  • on Mac: delete file

    ${user.home}/Library/Application Support/Google/Chrome/Default/Favicons

  • on Windows: delete files

    C:\Users[username]\AppData\Local\Google\Chrome\User Data\Default\Favicons C:\Users[username]\AppData\Local\Google\Chrome\User Data\Default\Favicons-journal

source

Error handling in getJSON calls

Here's my addition.

From http://www.learnjavascript.co.uk/jq/reference/ajax/getjson.html and the official source

"The jqXHR.success(), jqXHR.error(), and jqXHR.complete() callback methods introduced in jQuery 1.5 are deprecated as of jQuery 1.8. To prepare your code for their eventual removal, use jqXHR.done(), jqXHR.fail(), and jqXHR.always() instead."

I did that and here is Luciano's updated code snippet:

$.getJSON("example.json", function() {
  alert("success");
})
.done(function() { alert('getJSON request succeeded!'); })
.fail(function() { alert('getJSON request failed! '); })
.always(function() { alert('getJSON request ended!'); });

And with error description plus showing all json data as a string:

$.getJSON("example.json", function(data) {
  alert(JSON.stringify(data));
})
.done(function() { alert('getJSON request succeeded!'); })
.fail(function(jqXHR, textStatus, errorThrown) { alert('getJSON request failed! ' + textStatus); })
.always(function() { alert('getJSON request ended!'); });

If you don't like alerts, substitute them with console.log

$.getJSON("example.json", function(data) {
  console.log(JSON.stringify(data));
})
.done(function() { console.log('getJSON request succeeded!'); })
.fail(function(jqXHR, textStatus, errorThrown) { console.log('getJSON request failed! ' + textStatus); })
.always(function() { console.log('getJSON request ended!'); });

Eclipse: The resource is not on the build path of a Java project

You can add the src folder to build path by:

  1. Select Java perspective.
  2. Right click on src folder.
  3. Select Build Path > Use a source folder.

And you are done. Hope this help.

EDIT: Refer to the Eclipse documentation

How do you reinstall an app's dependencies using npm?

Delete node_module and re-install again by command

rm -rf node_modules && npm i

Call break in nested if statements

Actually there is no c3 in the sample code in the original question. So the if would be more properly

if (c1 && c2) {
    //sequence 1
} else if (!c1 && !c2) {
   // sequence 3
}

Is there any quick way to get the last two characters in a string?

The existing answers will fail if the string is empty or only has one character. Options:

String substring = str.length() > 2 ? str.substring(str.length() - 2) : str;

or

String substring = str.substring(Math.max(str.length() - 2, 0));

That's assuming that str is non-null, and that if there are fewer than 2 characters, you just want the original string.

How can I replace non-printable Unicode characters in Java?

methods in blow for your goal

public static String removeNonAscii(String str)
{
    return str.replaceAll("[^\\x00-\\x7F]", "");
}

public static String removeNonPrintable(String str) // All Control Char
{
    return str.replaceAll("[\\p{C}]", "");
}

public static String removeSomeControlChar(String str) // Some Control Char
{
    return str.replaceAll("[\\p{Cntrl}\\p{Cc}\\p{Cf}\\p{Co}\\p{Cn}]", "");
}

public static String removeFullControlChar(String str)
{
    return removeNonPrintable(str).replaceAll("[\\r\\n\\t]", "");
}