Programs & Examples On #Password policy

Create Hyperlink in Slack

you can try quoting it which will keep the link as text. see the code blocks section: https://get.slack.help/hc/en-us/articles/202288908-Format-your-messages#code-blocks

asp.net: Invalid postback or callback argument

My solution was to add:

ctlUpdatePanel.Update();

after binding control after postback. it was in updatepanel with UpdateMode="Conditional" attribute.

Hiding a form and showing another when a button is clicked in a Windows Forms application

Anything after Application.Run( ) will only be executed when the main form closes.

What you could do is handle the VisibleChanged event as follows:

static Form1 form1;
static Form2 form2;

static void Main()
{

    Application.EnableVisualStyles();
    Application.SetCompatibleTextRenderingDefault(false);
    form2 = new Form2();
    form1 = new Form1();
    form2.Hide();
    form1.VisibleChanged += OnForm1Changed;
    Application.Run(form1);

}

static void OnForm1Changed( object sender, EventArgs args )
{
    if ( !form1.Visible )
    {
        form2.Show( );
    }
}

converting Java bitmap to byte array

In order to avoid OutOfMemory error for bigger files, I would solve the task by splitting a bitmap into several parts and merging their parts' bytes.

private byte[] getBitmapBytes(Bitmap bitmap)
{
    int chunkNumbers = 10;
    int bitmapSize = bitmap.getRowBytes() * bitmap.getHeight();
    byte[] imageBytes = new byte[bitmapSize];
    int rows, cols;
    int chunkHeight, chunkWidth;
    rows = cols = (int) Math.sqrt(chunkNumbers);
    chunkHeight = bitmap.getHeight() / rows;
    chunkWidth = bitmap.getWidth() / cols;

    int yCoord = 0;
    int bitmapsSizes = 0;

    for (int x = 0; x < rows; x++)
    {
        int xCoord = 0;
        for (int y = 0; y < cols; y++)
        {
            Bitmap bitmapChunk = Bitmap.createBitmap(bitmap, xCoord, yCoord, chunkWidth, chunkHeight);
            byte[] bitmapArray = getBytesFromBitmapChunk(bitmapChunk);
            System.arraycopy(bitmapArray, 0, imageBytes, bitmapsSizes, bitmapArray.length);
            bitmapsSizes = bitmapsSizes + bitmapArray.length;
            xCoord += chunkWidth;

            bitmapChunk.recycle();
            bitmapChunk = null;
        }
        yCoord += chunkHeight;
    }

    return imageBytes;
}


private byte[] getBytesFromBitmapChunk(Bitmap bitmap)
{
    int bitmapSize = bitmap.getRowBytes() * bitmap.getHeight();
    ByteBuffer byteBuffer = ByteBuffer.allocate(bitmapSize);
    bitmap.copyPixelsToBuffer(byteBuffer);
    byteBuffer.rewind();
    return byteBuffer.array();
}

Default instance name of SQL Server Express

The default instance name after installing is,

Server name:

.\SQLExpress

Authentication:

Windows Authentication

Note: The period in the server Name field means your local machine. For remote machines, use the machine name instead of the period.

This video also helps you to Find your sql server name (instance) for Management Studio .

Android: Clear the back stack

In kotlin it is almost same like java. Only | symbol is replaced by or text. So, it is written like-

intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TASK or Intent.FLAG_ACTIVITY_NEW_TASK)

SQL LEFT-JOIN on 2 fields for MySQL

select a.ip, a.os, a.hostname, a.port, a.protocol,
       b.state
from a
left join b on a.ip = b.ip 
           and a.port = b.port

Android selector & text color

If using TextViews in tabs this selector definition worked for me (tried Klaus Balduino's but it did not):

<?xml version="1.0" encoding="utf-8"?>    
<selector xmlns:android="http://schemas.android.com/apk/res/android">

  <!--  Active tab -->
  <item
    android:state_selected="true"
    android:state_focused="false"
    android:state_pressed="false"
    android:color="#000000" />

  <!--  Inactive tab -->
  <item
    android:state_selected="false"
    android:state_focused="false"
    android:state_pressed="false"
    android:color="#FFFFFF" />

</selector>

How do I return a string from a regex match in python?

imgtag.group(0) or imgtag.group(). This returns the entire match as a string. You are not capturing anything else either.

http://docs.python.org/release/2.5.2/lib/match-objects.html

c++ boost split string

My best guess at why you had problems with the ----- covering your first result is that you actually read the input line from a file. That line probably had a \r on the end so you ended up with something like this:

-----------test2-------test3

What happened is the machine actually printed this:

test-------test2-------test3\r-------

That means, because of the carriage return at the end of test3, that the dashes after test3 were printed over the top of the first word (and a few of the existing dashes between test and test2 but you wouldn't notice that because they were already dashes).

Boxplot in R showing the mean

With ggplot2:

p<-qplot(spray,count,data=InsectSprays,geom='boxplot')
p<-p+stat_summary(fun.y=mean,shape=1,col='red',geom='point')
print(p)

org.hibernate.MappingException: Could not determine type for: java.util.Set

Not saying your mapping is correct or wrong but I think hibernate wants a instance of the set where you declare the field.

@OneToMany(cascade=CascadeType.ALL, fetch = FetchType.EAGER)
//@ElementCollection(targetClass=Role.class)
@Column(name = "ROLE_ID")
private Set<Role> roles = new HashSet<Role>();

How print out the contents of a HashMap<String, String> in ascending order based on its values?

the simplest and shortest code i think is this:

public void listPrinter(LinkedHashMap<String, String> caseList) {

    for(Entry entry:caseList.entrySet()) {
        System.out.println("K: \t"+entry.getKey()+", V: \t"+entry.getValue());
    }
}

Google Maps API v2: How to make markers clickable?

I added a mMap.setOnMarkerClickListener(this); in the onMapReady(GoogleMap googleMap) method. So every time you click a marker it displays the text name in the toast method.

public class DemoMapActivity extends AppCompatActivity implements NavigationView.OnNavigationItemSelectedListener,OnMapReadyCallback, GoogleMap.OnMarkerClickListener {

private GoogleMap mMap;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_places);
    Toolbar toolbar = findViewById(R.id.toolbar);
    setSupportActionBar(toolbar);
    SupportMapFragment mapFragment = (SupportMapFragment) getSupportFragmentManager().findFragmentById(R.id.map);
    mapFragment.getMapAsync(this);
}

@Override
public void onMapReady(GoogleMap googleMap) {
    mMap = googleMap;
    double lat=0.34924212701428;
    double lng=32.616554024713;
    String venue = "Capital Shoppers City";
    LatLng location = new LatLng(lat, lng);
    mMap.addMarker(new MarkerOptions().position(location).title(venue)).setTag(0);
    CameraUpdate cameraUpdate = CameraUpdateFactory.newLatLng(location);
    CameraUpdate zoom = CameraUpdateFactory.zoomTo(16);
    mMap.moveCamera(cameraUpdate);
    mMap.animateCamera(zoom);
    mMap.setOnMarkerClickListener(this);
}

@Override
public boolean onMarkerClick(final Marker marker) {
    // Retrieve the data from the marker.
    Integer clickCount = (Integer) marker.getTag();

    // Check if a click count was set, then display the click count.
    if (clickCount != null) {
        clickCount = clickCount + 1;
        marker.setTag(clickCount);
        Toast.makeText(this,
                       marker.getTitle() +
                       " has been clicked ",
                       Toast.LENGTH_SHORT).show();
    }
    // Return false to indicate that we have not consumed the event and that we wish
    // for the default behavior to occur (which is for the camera to move such that the
    // marker is centered and for the marker's info window to open, if it has one).
    return false;
}

}

You can check this link for reference Markers

Converting a JS object to an array using jQuery

You can create a simple function to do the conversion from object to array, something like this can do the job for you using pure javascript:

var objectToArray = function(obj) {
  var arr = [];
  if ('object' !== typeof obj || 'undefined' === typeof obj || Array.isArray(obj)) {
    return obj;
  } else {
    Object.keys(obj).map(x=>arr.push(obj[x]));
  }
  return arr;
};

or this one:

var objectToArray = function(obj) {
  var arr =[];
  for(let o in obj) {
    if (obj.hasOwnProperty(o)) {
      arr.push(obj[o]);
    }
  }
  return arr;
};

and call and use the function as below:

var obj = {1:'a', 2:'b', 3:'c', 4:'d', 5:'e'};
objectToArray(obj); // return ["a", "b", "c", "d", "e"]

Also in the future we will have something called Object.values(obj), similar to Object.keys(obj) which will return all properties for you as an array, but not supported in many browsers yet...

How can I decrypt MySQL passwords

You can't decrypt password in mysql, because password is hashed by using md5 hash algorithm, which is not an encoding algorithm.

byte[] to hex string

Just to add one more answer to the pile, there is a System.Runtime.Remoting.Metadata.W3cXsd2001.SoapHexBinary class that I've used which can convert bytes to and from hex:

string hex = new SoapHexBinary(bytes).ToString();
byte[] bytes = SoapHexBinary.Parse(hex).Value;

Not sure how it compares (benchmark) to other implementations, but IMO it is pretty simple -- especially for converting from hex back into bytes.

printf() prints whole array

But still, the memory address for each letter in this address is different.

Memory address is different but as its array of characters they are sequential. When you pass address of first element and use %s, printf will print all characters starting from given address until it finds '\0'.

Pandas: create two new columns in a dataframe with values calculated from a pre-existing column

I'd just use zip:

In [1]: from pandas import *

In [2]: def calculate(x):
   ...:     return x*2, x*3
   ...: 

In [3]: df = DataFrame({'a': [1,2,3], 'b': [2,3,4]})

In [4]: df
Out[4]: 
   a  b
0  1  2
1  2  3
2  3  4

In [5]: df["A1"], df["A2"] = zip(*df["a"].map(calculate))

In [6]: df
Out[6]: 
   a  b  A1  A2
0  1  2   2   3
1  2  3   4   6
2  3  4   6   9

How to concatenate strings with padding in sqlite

Just one more line for @tofutim answer ... if you want custom field name for concatenated row ...

SELECT 
  (
    col1 || '-' || SUBSTR('00' || col2, -2, 2) | '-' || SUBSTR('0000' || col3, -4, 4)
  ) AS my_column 
FROM
  mytable;

Tested on SQLite 3.8.8.3, Thanks!

Why is the console window closing immediately once displayed my output?

According to my concern, if we want to stable the OUTPUT OF CONSOLE APPLICATION, till the close of output display USE, the label: after the MainMethod, and goto label; before end of the program

In the Program.

eg:

static void Main(string[] args)
{
    label:

    // Snippet of code

    goto label;
}

How to convert Moment.js date to users local timezone?

Use utcOffset function.

var testDateUtc = moment.utc("2015-01-30 10:00:00");
var localDate = moment(testDateUtc).utcOffset(10 * 60); //set timezone offset in minutes
console.log(localDate.format()); //2015-01-30T20:00:00+10:00

How to automatically add user account AND password with a Bash script?

Single liner to create a sudo user with home directory and password.

useradd -m -p $(openssl passwd -1 ${PASSWORD}) -s /bin/bash -G sudo ${USERNAME}

Convert data.frame columns from factors to characters

This works for me - I finally figured a one liner

df <- as.data.frame(lapply(df,function (y) if(class(y)=="factor" ) as.character(y) else y),stringsAsFactors=F)

In PowerShell, how do I define a function in a file and call it from the PowerShell commandline?

You certainly can define functions in script files (I then tend to load them through my Powershell profile on load).

First you need to check to make sure the function is loaded by running:

ls function:\ | where { $_.Name -eq "A1"  }

And check that it appears in the list (should be a list of 1!), then let us know what output you get!

One liner for If string is not null or empty else

You could use the ternary operator:

return string.IsNullOrEmpty(strTestString) ? "0" : strTestString

FooTextBox.Text = string.IsNullOrEmpty(strFoo) ? "0" : strFoo;

How to delete an array element based on key?

You don't say what language you're using, but looking at that output, it looks like PHP output (from print_r()).
If so, just use unset():

unset($arr[1]);

What does $(function() {} ); do?

This is a shortcut for $(document).ready(), which is executed when the browser has finished loading the page (meaning here, "when the DOM is available"). See http://www.learningjquery.com/2006/09/introducing-document-ready. If you are trying to call example() before the browser has finished loading the page, it may not work.

How to use cookies in Python Requests

You can use a session object. It stores the cookies so you can make requests, and it handles the cookies for you

s = requests.Session() 
# all cookies received will be stored in the session object

s.post('http://www...',data=payload)
s.get('http://www...')

Docs: https://requests.readthedocs.io/en/master/user/advanced/#session-objects

You can also save the cookie data to an external file, and then reload them to keep session persistent without having to login every time you run the script:

How to save requests (python) cookies to a file?

How to commit changes to a new branch

git checkout -b your-new-branch

git add <files>

git commit -m <message>

First, checkout your new branch. Then add all the files you want to commit to staging. Lastly, commit all the files you just added. You might want to do a git push origin your-new-branch afterward so your changes show up on the remote.

Matplotlib legends in subplot

This does what you want and overcomes some of the problems in other answers:

import matplotlib.pyplot as plt

labels = ["HHZ 1", "HHN", "HHE"]
colors = ["r","g","b"]

f,axs = plt.subplots(3, sharex=True, sharey=True)

# ---- loop over axes ----
for i,ax in enumerate(axs):
  axs[i].plot([0,1],[1,0],color=colors[i],label=labels[i])
  axs[i].legend(loc="upper right")

plt.show()

... produces ... subplots

What is a user agent stylesheet?

I just wanted to expand on the response from @BenM based on what I read here from Ire Aderinokun. Because the user-agent stylesheet provides helpful default styling, think twice before overriding it.

I had a dumb error where a button element didn't look right in Chrome. I had partially styled it because I didn't want it to look like a traditional button. However, I left out style elements like border, border-color, etc. So Chrome was stepping in to supply the parts that it thought I was missing.

The problem went away once I added styles like border: none, etc.

So if anyone else is having this problem, make sure you are explicitly overriding all the applicable default user-agent styles for an element if you notice it looks wonky, especially if you don't want to reset the user agent styles completely. It worked for me.

How to display div after click the button in Javascript?

HTML

<div id="myDiv" style="display:none;" class="answer_list" >WELCOME</div>
<input type="button" name="answer" onclick="ShowDiv()" />

JavaScript

function ShowDiv() {
    document.getElementById("myDiv").style.display = "";
}

Or if you wanted to use jQuery with a nice little animation:

<input id="myButton" type="button" name="answer" />

$('#myButton').click(function() {
  $('#myDiv').toggle('slow', function() {
    // Animation complete.
  });
});

How do I refresh a DIV content?

For div refreshing without creating div inside yours with same id, you should use this inside your function

$("#yourDiv").load(" #yourDiv > *");

SELECT max(x) is returning null; how can I make it return 0?

or:

SELECT coalesce(MAX(X), 0) AS MaxX
FROM tbl
WHERE XID = 1

How to delete duplicate lines in a file without sorting it in Unix?

cat filename | sort | uniq -c | awk -F" " '$1<2 {print $2}'

Deletes the duplicate lines using awk.

ld cannot find -l<library>

You may install your coinhsl library in one of your standard libraries directories and run 'ldconfig` before doing your ppyipopt install

Converting VS2012 Solution to VS2010

Simple solution which worked for me.

  1. Install Vim editor for windows.
  2. Open VS 2012 project solution using Vim editor and modify the version targetting Visual studio solution 10.
  3. Open solution with Visual studio 2010.. and continue with your work ;)

Date format in the json output using spring boot

If you have Jackson integeration with your application to serialize your bean to JSON format, then you can use Jackson anotation @JsonFormat to format your date to specified format.
In your case if you need your date into yyyy-MM-dd format you need to specify @JsonFormat above your field on which you want to apply this format.

For Example :

public class Subject {

     private String uid;
     private String number;
     private String initials;

     @JsonFormat(pattern="yyyy-MM-dd")
     private Date dateOfBirth;  

     //Other Code  

}  

From Docs :

annotation used for configuring details of how values of properties are to be serialized.

More Reference Doc

Hope this helps.

jQuery: Check if div with certain class name exists

You can simplify this by checking the first object that is returned from JQuery like so:

if ($(".mydivclass")[0]){
    // Do something if class exists
} else {
    // Do something if class does not exist
}

In this case if there is a truthy value at the first ([0]) index, then assume class exists.

Edit 04/10/2013: I've created a jsperf test case here.

Getting value GET OR POST variable using JavaScript?

You can only get the URI arguments with JavaScript.

// get query arguments
var $_GET = {},
    args = location.search.substr(1).split(/&/);
for (var i=0; i<args.length; ++i) {
    var tmp = args[i].split(/=/);
    if (tmp[0] != "") {
        $_GET[decodeURIComponent(tmp[0])] = decodeURIComponent(tmp.slice(1).join("").replace("+", " "));
    }
}

html "data-" attribute as javascript parameter

The short answer is that the syntax is this.dataset.whatever.

Your code should look like this:

<div data-uid="aaa" data-name="bbb" data-value="ccc"
    onclick="fun(this.dataset.uid, this.dataset.name, this.dataset.value)">

Another important note: Javascript will always strip out hyphens and make the data attributes camelCase, regardless of whatever capitalization you use. data-camelCase will become this.dataset.camelcase and data-Camel-case will become this.dataset.camelCase.

jQuery (after v1.5 and later) always uses lowercase, regardless of your capitalization.

So when referencing your data attributes using this method, remember the camelCase:

<div data-this-is-wild="yes, it's true"
    onclick="fun(this.dataset.thisIsWild)">

Also, you don't need to use commas to separate attributes.

Event when window.location.href changes

Well there is 2 ways to change the location.href. Either you can write location.href = "y.html", which reloads the page or can use the history API which does not reload the page. I experimented with the first a lot recently.

If you open a child window and capture the load of the child page from the parent window, then different browsers behave very differently. The only thing that is common, that they remove the old document and add a new one, so for example adding readystatechange or load event handlers to the old document does not have any effect. Most of the browsers remove the event handlers from the window object too, the only exception is Firefox. In Chrome with Karma runner and in Firefox you can capture the new document in the loading readyState if you use unload + next tick. So you can add for example a load event handler or a readystatechange event handler or just log that the browser is loading a page with a new URI. In Chrome with manual testing (probably GreaseMonkey too) and in Opera, PhantomJS, IE10, IE11 you cannot capture the new document in the loading state. In those browsers the unload + next tick calls the callback a few hundred msecs later than the load event of the page fires. The delay is typically 100 to 300 msecs, but opera simetime makes a 750 msec delay for next tick, which is scary. So if you want a consistent result in all browsers, then you do what you want to after the load event, but there is no guarantee the location won't be overridden before that.

var uuid = "win." + Math.random();
var timeOrigin = new Date();
var win = window.open("about:blank", uuid, "menubar=yes,location=yes,resizable=yes,scrollbars=yes,status=yes");


var callBacks = [];
var uglyHax = function (){
    var done = function (){
        uglyHax();
        callBacks.forEach(function (cb){
            cb();
        });
    };
    win.addEventListener("unload", function unloadListener(){
        win.removeEventListener("unload", unloadListener); // Firefox remembers, other browsers don't
        setTimeout(function (){
            // IE10, IE11, Opera, PhantomJS, Chrome has a complete new document at this point
            // Chrome on Karma, Firefox has a loading new document at this point
            win.document.readyState; // IE10 and IE11 sometimes fails if I don't access it twice, idk. how or why
            if (win.document.readyState === "complete")
                done();
            else
                win.addEventListener("load", function (){
                    setTimeout(done, 0);
                });
        }, 0);
    });
};
uglyHax();


callBacks.push(function (){
    console.log("cb", win.location.href, win.document.readyState);
    if (win.location.href !== "http://localhost:4444/y.html")
        win.location.href = "http://localhost:4444/y.html";
    else
        console.log("done");
});
win.location.href = "http://localhost:4444/x.html";

If you run your script only in Firefox, then you can use a simplified version and capture the document in a loading state, so for example a script on the loaded page cannot navigate away before you log the URI change:

var uuid = "win." + Math.random();
var timeOrigin = new Date();
var win = window.open("about:blank", uuid, "menubar=yes,location=yes,resizable=yes,scrollbars=yes,status=yes");


var callBacks = [];
win.addEventListener("unload", function unloadListener(){
    setTimeout(function (){
        callBacks.forEach(function (cb){
            cb();
        });
    }, 0);
});


callBacks.push(function (){
    console.log("cb", win.location.href, win.document.readyState);
    // be aware that the page is in loading readyState, 
    // so if you rewrite the location here, the actual page will be never loaded, just the new one
    if (win.location.href !== "http://localhost:4444/y.html")
        win.location.href = "http://localhost:4444/y.html";
    else
        console.log("done");
});
win.location.href = "http://localhost:4444/x.html";

If we are talking about single page applications which change the hash part of the URI, or use the history API, then you can use the hashchange and the popstate events of the window respectively. Those can capture even if you move in history back and forward until you stay on the same page. The document does not changes by those and the page is not really reloaded.

How to install sklearn?

I would recommend you look at getting the anaconda package, it will install and configure Sklearn and its dependencies.

https://www.continuum.io

SQL exclude a column using SELECT * [except columnA] FROM tableA?

In Hive Sql you can do this:

set hive.support.quoted.identifiers=none;
select 
    `(unwanted_col1|unwanted_col2|unwanted_col3)?+.+`
from database.table

this gives you the rest cols

Can I use jQuery with Node.js?

None of these solutions has helped me in my Electron App.

My solution (workaround):

npm install jquery

In your index.js file:

var jQuery = $ = require('jquery');

In your .js files write yours jQuery functions in this way:

jQuery(document).ready(function() {

How to find the duration of difference between two dates in java?

You can create a method like

public long getDaysBetweenDates(Date d1, Date d2){
return TimeUnit.MILLISECONDS.toDays(d1.getTime() - d2.getTime());
}

This method will return the number of days between the 2 days.

Excel formula to get ranking position

If your C-column is sorted, you can check whether the current row is equal to your last row. If not, use the current row number as the ranking-position, otherwise use the value from above (value for b3):

=IF(C3=C2, B2, ROW()-1)

You can use the LARGE function to get the n-th highest value in case your C-column is not sorted:

=LARGE(C2:C7,3)

placeholder for select tag

Try this

HTML

<select class="form-control"name="country">
<option class="servce_pro_disabled">Select Country</option>
<option class="servce_pro_disabled" value="Aruba" id="cl_country_option">Aruba</option>
</select>

CSS

.form-control option:first-child {
    display: none;
}

jQuery/JavaScript: accessing contents of an iframe

You need to attach an event to an iframe's onload handler, and execute the js in there, so that you make sure the iframe has finished loading before accessing it.

$().ready(function () {
    $("#iframeID").ready(function () { //The function below executes once the iframe has finished loading
        $('some selector', frames['nameOfMyIframe'].document).doStuff();
    });
};

The above will solve the 'not-yet-loaded' problem, but as regards the permissions, if you are loading a page in the iframe that is from a different domain, you won't be able to access it due to security restrictions.

Gunicorn worker timeout error

Could it be this? http://docs.gunicorn.org/en/latest/settings.html#timeout

Other possibilities could be your response is taking too long or is stuck waiting.

Arduino Sketch upload issue - avrdude: stk500_recv(): programmer is not responding

My problem was that I updated the Arduino IDE to a new version and did not reconnect the wire. Looks like that was the problem

Just disconnect the cable and connect again. Thanks.

How do I execute a bash script in Terminal?

If you are in a directory or folder where the script file is available then simply change the file permission in executable mode by doing

chmod +x your_filename.sh

After that you will run the script by using the following command.

$ sudo ./your_filename.sh

Above the "." represent the current directory. Note! If you are not in the directory where the bash script file is present then you change the directory where the file is located by using

cd Directory_name/write the complete path

command. Otherwise your script can not run.

Update all objects in a collection using LINQ

You can use LINQ to convert your collection to an array and then invoke Array.ForEach():

Array.ForEach(MyCollection.ToArray(), item=>item.DoSomeStuff());

Obviously this will not work with collections of structs or inbuilt types like integers or strings.

How to add a Try/Catch to SQL Stored Procedure

Error-Handling with SQL Stored Procedures

TRY/CATCH error handling can take place either within or outside of a procedure (or both). The examples below demonstrate error handling in both cases.

If you want to experiment further, you can fork the query on Stack Exchange Data Explorer.

(This uses a temporary stored procedure... we can't create regular SP's on SEDE, but the functionality is the same.)

--our Stored Procedure
create procedure #myProc as --we can only create #temporary stored procedures on SEDE. 
  begin
    BEGIN TRY
      print 'This is our Stored Procedure.'
      print 1/0                          --<-- generate a "Divide By Zero" error.
      print 'We are not going to make it to this line.'
    END TRY

    BEGIN CATCH
      print 'This is the CATCH block within our Stored Procedure:'
          + ' Error Line #'+convert(varchar,ERROR_LINE())
          + ' of procedure '+isnull(ERROR_PROCEDURE(),'(Main)')
      --print 1/0                        --<-- generate another "Divide By Zero" error.
        -- uncomment the line above to cause error within the CATCH ¹ 
    END CATCH
  end
go

--our MAIN code block:
BEGIN TRY
  print 'This is our MAIN Procedure.'
  execute #myProc  --execute the Stored Procedure
      --print 1/0                        --<-- generate another "Divide By Zero" error.
        -- uncomment the line above to cause error within the MAIN Procedure ²
  print 'Now our MAIN sql code block continues.'
END TRY

BEGIN CATCH
  print 'This is the CATCH block for our MAIN sql code block:'
          + ' Error Line #'+convert(varchar,ERROR_LINE())
          + ' of procedure '+isnull(ERROR_PROCEDURE(),'(Main)')
END CATCH

Here's the result of running the above sql as-is:

This is our MAIN Procedure.
This is our Stored Procedure.
This is the CATCH block within our Stored Procedure: Error Line #5 of procedure #myProc
Now our MAIN sql code block continues.

¹ Uncommenting the "additional error line" from the Stored Procedure's CATCH block will produce:

This is our MAIN procedure.
This is our Stored Procedure.
This is the CATCH block within our Stored Procedure: Error Line #5 of procedure #myProc
This is the CATCH block for our MAIN sql code block: Error Line #13 of procedure #myProc

² Uncommenting the "additional error line" from the MAIN procedure will produce:

This is our MAIN Procedure.
This is our Stored Pprocedure.
This is the CATCH block within our Stored Procedure: Error Line #5 of procedure #myProc
This is the CATCH block for our MAIN sql code block: Error Line #4 of procedure (Main)

Use a single procedure for error handling

On topic of stored procedures and error handling, it can be helpful (and tidier) to use a single, dynamic, stored procedure to handle errors for multiple other procedures or code sections.

Here's an example:

--our error handling procedure
create procedure #myErrorHandling as
  begin
    print ' Error #'+convert(varchar,ERROR_NUMBER())+': '+ERROR_MESSAGE()  
    print ' occurred on line #'+convert(varchar,ERROR_LINE())
         +' of procedure '+isnull(ERROR_PROCEDURE(),'(Main)')
    if ERROR_PROCEDURE() is null       --check if error was in MAIN Procedure
      print '*Execution cannot continue after an error in the MAIN Procedure.'
  end
go

create procedure #myProc as     --our test Stored Procedure
  begin
    BEGIN TRY
      print 'This is our Stored Procedure.'
      print 1/0                       --generate a "Divide By Zero" error.
      print 'We will not make it to this line.'
    END TRY
    BEGIN CATCH
     execute #myErrorHandling
    END CATCH
  end
go

BEGIN TRY                       --our MAIN Procedure
  print 'This is our MAIN Procedure.'
  execute #myProc                     --execute the Stored Procedure
  print '*The error halted the procedure, but our MAIN code can continue.'
  print 1/0                           --generate another "Divide By Zero" error.
  print 'We will not make it to this line.'
END TRY
BEGIN CATCH
  execute #myErrorHandling
END CATCH

Example Output: (This query can be forked on SEDE here.)

This is our MAIN procedure.
This is our stored procedure.
 Error #8134: Divide by zero error encountered.
 occurred on line #5 of procedure #myProc
*The error halted the procedure, but our MAIN code can continue.
 Error #8134: Divide by zero error encountered.
 occurred on line #5 of procedure (Main)
*Execution cannot continue after an error in the MAIN procedure.

Documentation:

In the scope of a TRY/CATCH block, the following system functions can be used to obtain information about the error that caused the CATCH block to be executed:

  • ERROR_NUMBER() returns the number of the error.
  • ERROR_SEVERITY() returns the severity.
  • ERROR_STATE() returns the error state number.
  • ERROR_PROCEDURE() returns the name of the stored procedure or trigger where the error occurred.
  • ERROR_LINE() returns the line number inside the routine that caused the error.
  • ERROR_MESSAGE() returns the complete text of the error message. The text includes the values supplied for any substitutable parameters, such as lengths, object names, or times.

(Source)

Note that there are two types of SQL errors: Terminal and Catchable. TRY/CATCH will [obviously] only catch the "Catchable" errors. This is one of a number of ways of learning more about your SQL errors, but it probably the most useful.

It's "better to fail now" (during development) compared to later because, as Homer says . . .

Compression/Decompression string with C#

I like @fubo's answer the best but I think this is much more elegant.

This method is more compatible because it doesn't manually store the length up front.

Also I've exposed extensions to support compression for string to string, byte[] to byte[], and Stream to Stream.

public static class ZipExtensions
{
    public static string CompressToBase64(this string data)
    {
        return Convert.ToBase64String(Encoding.UTF8.GetBytes(data).Compress());
    }

    public static string DecompressFromBase64(this string data)
    {
        return Encoding.UTF8.GetString(Convert.FromBase64String(data).Decompress());
    }
    
    public static byte[] Compress(this byte[] data)
    {
        using (var sourceStream = new MemoryStream(data))
        using (var destinationStream = new MemoryStream())
        {
            sourceStream.CompressTo(destinationStream);
            return destinationStream.ToArray();
        }
    }

    public static byte[] Decompress(this byte[] data)
    {
        using (var sourceStream = new MemoryStream(data))
        using (var destinationStream = new MemoryStream())
        {
            sourceStream.DecompressTo(destinationStream);
            return destinationStream.ToArray();
        }
    }
    
    public static void CompressTo(this Stream stream, Stream outputStream)
    {
        using (var gZipStream = new GZipStream(outputStream, CompressionMode.Compress))
        {
            stream.CopyTo(gZipStream);
            gZipStream.Flush();
        }
    }

    public static void DecompressTo(this Stream stream, Stream outputStream)
    {
        using (var gZipStream = new GZipStream(stream, CompressionMode.Decompress))
        {
            gZipStream.CopyTo(outputStream);
        }
    }
}

How to export data from Spark SQL to CSV

The simplest way is to map over the DataFrame's RDD and use mkString:

  df.rdd.map(x=>x.mkString(","))

As of Spark 1.5 (or even before that) df.map(r=>r.mkString(",")) would do the same if you want CSV escaping you can use apache commons lang for that. e.g. here's the code we're using

 def DfToTextFile(path: String,
                   df: DataFrame,
                   delimiter: String = ",",
                   csvEscape: Boolean = true,
                   partitions: Int = 1,
                   compress: Boolean = true,
                   header: Option[String] = None,
                   maxColumnLength: Option[Int] = None) = {

    def trimColumnLength(c: String) = {
      val col = maxColumnLength match {
        case None => c
        case Some(len: Int) => c.take(len)
      }
      if (csvEscape) StringEscapeUtils.escapeCsv(col) else col
    }
    def rowToString(r: Row) = {
      val st = r.mkString("~-~").replaceAll("[\\p{C}|\\uFFFD]", "") //remove control characters
      st.split("~-~").map(trimColumnLength).mkString(delimiter)
    }

    def addHeader(r: RDD[String]) = {
      val rdd = for (h <- header;
                     if partitions == 1; //headers only supported for single partitions
                     tmpRdd = sc.parallelize(Array(h))) yield tmpRdd.union(r).coalesce(1)
      rdd.getOrElse(r)
    }

    val rdd = df.map(rowToString).repartition(partitions)
    val headerRdd = addHeader(rdd)

    if (compress)
      headerRdd.saveAsTextFile(path, classOf[GzipCodec])
    else
      headerRdd.saveAsTextFile(path)
  }

Using Python's ftplib to get a directory listing, portably

The reliable/standardized way to parse FTP directory listing is by using MLSD command, which by now should be supported by all recent/decent FTP servers.

import ftplib
f = ftplib.FTP()
f.connect("localhost")
f.login()
ls = []
f.retrlines('MLSD', ls.append)
for entry in ls:
    print entry

The code above will print:

modify=20110723201710;perm=el;size=4096;type=dir;unique=807g4e5a5; tests
modify=20111206092323;perm=el;size=4096;type=dir;unique=807g1008e0; .xchat2
modify=20111022125631;perm=el;size=4096;type=dir;unique=807g10001a; .gconfd
modify=20110808185618;perm=el;size=4096;type=dir;unique=807g160f9a; .skychart
...

Starting from python 3.3, ftplib will provide a specific method to do this:

How to parse a JSON string into JsonNode in Jackson?

Richard's answer is correct. Alternatively you can also create a MappingJsonFactory (in org.codehaus.jackson.map) which knows where to find ObjectMapper. The error you got was because the regular JsonFactory (from core package) has no dependency to ObjectMapper (which is in the mapper package).

But usually you just use ObjectMapper and do not worry about JsonParser or other low level components -- they will just be needed if you want to data-bind parts of stream, or do low-level handling.

HttpServletRequest get JSON POST data

Normaly you can GET and POST parameters in a servlet the same way:

request.getParameter("cmd");

But only if the POST data is encoded as key-value pairs of content type: "application/x-www-form-urlencoded" like when you use a standard HTML form.

If you use a different encoding schema for your post data, as in your case when you post a json data stream, you need to use a custom decoder that can process the raw datastream from:

BufferedReader reader = request.getReader();

Json post processing example (uses org.json package )

public void doPost(HttpServletRequest request, HttpServletResponse response)
  throws ServletException, IOException {

  StringBuffer jb = new StringBuffer();
  String line = null;
  try {
    BufferedReader reader = request.getReader();
    while ((line = reader.readLine()) != null)
      jb.append(line);
  } catch (Exception e) { /*report an error*/ }

  try {
    JSONObject jsonObject =  HTTP.toJSONObject(jb.toString());
  } catch (JSONException e) {
    // crash and burn
    throw new IOException("Error parsing JSON request string");
  }

  // Work with the data using methods like...
  // int someInt = jsonObject.getInt("intParamName");
  // String someString = jsonObject.getString("stringParamName");
  // JSONObject nestedObj = jsonObject.getJSONObject("nestedObjName");
  // JSONArray arr = jsonObject.getJSONArray("arrayParamName");
  // etc...
}

plot with custom text for x axis points

This worked for me. Each month on X axis

str_month_list = ['January','February','March','April','May','June','July','August','September','October','November','December']
ax.set_xticks(range(0,12))
ax.set_xticklabels(str_month_list)

Loop through a comma-separated shell variable

If you set a different field separator, you can directly use a for loop:

IFS=","
for v in $variable
do
   # things with "$v" ...
done

You can also store the values in an array and then loop through it as indicated in How do I split a string on a delimiter in Bash?:

IFS=, read -ra values <<< "$variable"
for v in "${values[@]}"
do
   # things with "$v"
done

Test

$ variable="abc,def,ghij"
$ IFS=","
$ for v in $variable
> do
> echo "var is $v"
> done
var is abc
var is def
var is ghij

You can find a broader approach in this solution to How to iterate through a comma-separated list and execute a command for each entry.

Examples on the second approach:

$ IFS=, read -ra vals <<< "abc,def,ghij"
$ printf "%s\n" "${vals[@]}"
abc
def
ghij
$ for v in "${vals[@]}"; do echo "$v --"; done
abc --
def --
ghij --

Header div stays at top, vertical scrolling div below with scrollbar only attached to that div

You need to use js get better height for body div

<html><body>
<div id="head" style="height:50px; width=100%; font-size:50px;">This is head</div>
<div id="body" style="height:700px; font-size:100px; white-space:pre-wrap;    overflow:scroll;">
This is body
T
h
i
s

i
s

b 
o
d
y
</div>
</body></html>

How to make rounded percentages add up to 100%

I'm not sure what level of accuracy you need, but what I would do is simply add 1 the first n numbers, n being the ceil of the total sum of decimals. In this case that is 3, so I would add 1 to the first 3 items and floor the rest. Of course this is not super accurate, some numbers might be rounded up or down when it shouldn't but it works okay and will always result in 100%.

So [ 13.626332, 47.989636, 9.596008, 28.788024 ] would be [14, 48, 10, 28] because Math.ceil(.626332+.989636+.596008+.788024) == 3

function evenRound( arr ) {
  var decimal = -~arr.map(function( a ){ return a % 1 })
    .reduce(function( a,b ){ return a + b }); // Ceil of total sum of decimals
  for ( var i = 0; i < decimal; ++i ) {
    arr[ i ] = ++arr[ i ]; // compensate error by adding 1 the the first n items
  }
  return arr.map(function( a ){ return ~~a }); // floor all other numbers
}

var nums = evenRound( [ 13.626332, 47.989636, 9.596008, 28.788024 ] );
var total = nums.reduce(function( a,b ){ return a + b }); //=> 100

You can always inform users that the numbers are rounded and may not be super-accurate...

Angular ng-if="" with multiple arguments

For people looking to do if statements with multiple 'or' values.

<div ng-if="::(a || b || c || d || e || f)"><div>

Convert Array to Object

I have faced this issue multiple times and decided to write a function that is as generic as possible. Have a look and feel free to modify anything

function typeOf(obj) {
    if ( typeof(obj) == 'object' ) {
        if (obj.length)
            return 'array';
        else
            return 'object';
    } else
    return typeof(obj);
}

function objToArray(obj, ignoreKeys) {
    var arr = [];
    if (typeOf(obj) == 'object') {
        for (var key in obj) {
            if (typeOf(obj[key]) == 'object') {
                if (ignoreKeys)
                    arr.push(objToArray(obj[key],ignoreKeys));
                else
                    arr.push([key,objToArray(obj[key])]);
            }
            else
                arr.push(obj[key]);
        }
    }else if (typeOf(obj) == 'array') {
        for (var key=0;key<obj.length;key++) {
            if (typeOf(obj[key]) == 'object')
                arr.push(objToArray(obj[key]));
            else
                arr.push(obj[key]);
        }
    }
    return arr;
}

Generator expressions vs. list comprehensions

John's answer is good (that list comprehensions are better when you want to iterate over something multiple times). However, it's also worth noting that you should use a list if you want to use any of the list methods. For example, the following code won't work:

def gen():
    return (something for something in get_some_stuff())

print gen()[:2]     # generators don't support indexing or slicing
print [5,6] + gen() # generators can't be added to lists

Basically, use a generator expression if all you're doing is iterating once. If you want to store and use the generated results, then you're probably better off with a list comprehension.

Since performance is the most common reason to choose one over the other, my advice is to not worry about it and just pick one; if you find that your program is running too slowly, then and only then should you go back and worry about tuning your code.

How to avoid 'cannot read property of undefined' errors?

If you have lodash you can use its .get method

_.get(a, 'b.c.d.e')

or give it a default value

_.get(a, 'b.c.d.e', default)

Hiding a button in Javascript

You can use this code:

btnID.hidden = true;

jQuery add blank option to top of list and make selected to existing dropdown

Solution native Javascript :

document.getElementById("theSelectId").insertBefore(new Option('', ''), document.getElementById("theSelectId").firstChild);

example : http://codepen.io/anon/pen/GprybL

In java how to get substring from a string till a character c?

How about using regex?

String firstWord = filename.replaceAll("\\..*","")

This replaces everything from the first dot to the end with "" (ie it clears it, leaving you with what you want)

Here's a test:

System.out.println("abc.def.hij".replaceAll("\\..*", "");

Output:

abc

Location of the android sdk has not been setup in the preferences in mac os?

If you already setup location in preferences, but see that error, try to create folder "add-ons" in your sdk folder

How to send 500 Internal Server Error error from a PHP script

header($_SERVER['SERVER_PROTOCOL'] . ' 500 Internal Server Error', true, 500);

Migration: Cannot add foreign key constraint

It also may be your the ordering of creation migration. If you firstly create priorities table, and after users table then it will be wrong. Because of first migration looking for users table. So, you have to change the ordering of migration on

app/database/migrations

directory

Converting a char to uppercase

If you are including the apache commons lang jar in your project than the easiest solution would be to do:

WordUtils.capitalize(Name)

takes care of all the dirty work for you. See the javadoc here

Alternatively, you also have a capitalizeFully(String) method which also lower cases the rest of the characters.

Reverse order of foreach list items

<?php
    $j=1; 


      array_reverse($skills_nav);   


    foreach ( $skills_nav as $skill ) {
        $a = '<li><a href="#" data-filter=".'.$skill->slug.'">';
        $a .= $skill->name;                 
        $a .= '</a></li>';
        echo $a;
        echo "\n";
        $j++;
    }
?> 

Android 8.0: java.lang.IllegalStateException: Not allowed to start service Intent

Alternate solution by using JobScheduler, it can start service in background in regular interval of time.

Firstly make class named as Util.java

import android.app.job.JobInfo;
import android.app.job.JobScheduler;
import android.content.ComponentName;
import android.content.Context;

public class Util {
// schedule the start of the service every 10 - 30 seconds
public static void schedulerJob(Context context) {
    ComponentName serviceComponent = new ComponentName(context,TestJobService.class);
    JobInfo.Builder builder = new JobInfo.Builder(0,serviceComponent);
    builder.setMinimumLatency(1*1000);    // wait at least
    builder.setOverrideDeadline(3*1000);  //delay time
    builder.setRequiredNetworkType(JobInfo.NETWORK_TYPE_UNMETERED);  // require unmetered network
    builder.setRequiresCharging(false);  // we don't care if the device is charging or not
    builder.setRequiresDeviceIdle(true); // device should be idle
    System.out.println("(scheduler Job");

    JobScheduler jobScheduler = null;
    if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.M) {
        jobScheduler = context.getSystemService(JobScheduler.class);
    }
    jobScheduler.schedule(builder.build());
   }
  }

Then, make JobService class named as TestJobService.java

import android.app.job.JobParameters;
import android.app.job.JobService;
import android.widget.Toast;
 
  /**
   * JobService to be scheduled by the JobScheduler.
   * start another service
   */ 
public class TestJobService extends JobService {
@Override
public boolean onStartJob(JobParameters params) {
    Util.schedulerJob(getApplicationContext()); // reschedule the job
    Toast.makeText(this, "Bg Service", Toast.LENGTH_SHORT).show();
    return true;
}

@Override
public boolean onStopJob(JobParameters params) {
    return true;
  }
 }

After that BroadCast Receiver class named ServiceReceiver.java

import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;

 public class ServiceReceiver extends BroadcastReceiver {
 @Override
public void onReceive(Context context, Intent intent) {
    Util.schedulerJob(context);
 }
}

Update Manifest file with service and receiver class code

<receiver android:name=".ServiceReceiver" >
        <intent-filter>
            <action android:name="android.intent.action.BOOT_COMPLETED" />
        </intent-filter>
    </receiver>
    <service
        android:name=".TestJobService"
        android:label="Word service"
        android:permission="android.permission.BIND_JOB_SERVICE" >

    </service>

Left main_intent launcher to mainActivity.java file which is created by default, and changes in MainActivity.java file are

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;

public class MainActivity extends AppCompatActivity {

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    Util.schedulerJob(getApplicationContext());
  }
 }

WOOAAH!! Background Service starts without Foreground service

[Edit]: You can use Work Manager for any type of background tasks in Android.

SSL peer shut down incorrectly in Java

I had mutual SSL enabled on my Spring Boot app and my Jenkins pipeline was re-building the dockers, bringing the compose up and then running integration tests which failed every time with this error. I was able to test the running dockers without this SSL error every time in a standalone test on the same Jenkins machine. It turned out that server was not completely up when the tests started executing. Putting a sleep of few seconds in my bash script to allow Spring boot application to be up and running completely resolved the issue.

ggplot2, change title size

+ theme(plot.title = element_text(size=22))

Here is the full set of things you can change in element_text:

element_text(family = NULL, face = NULL, colour = NULL, size = NULL,
  hjust = NULL, vjust = NULL, angle = NULL, lineheight = NULL,
  color = NULL)

Difference between Git and GitHub

What is Git:

"Git is a free and open source distributed version control system designed to handle everything from small to very large projects with speed and efficiency"

Git is a distributed peer-peer version control system. Each node in the network is a peer, storing entire repositories which can also act as a multi-node distributed back-ups. There is no specific concept of a central server although nodes can be head-less or 'bare', taking on a role similar to the central server in centralised version control systems.

What is GitHub:

"GitHub is a web-based Git repository hosting service, which offers all of the distributed revision control and source code management (SCM) functionality of Git as well as adding its own features."

Github provides access control and several collaboration features such as wikis, task management, and bug tracking and feature requests for every project.

You do not need GitHub to use Git.

GitHub (and any other local, remote or hosted system) can all be peers in the same distributed versioned repositories within a single project.

Github allows you to:

  • Share your repositories with others.
  • Access other user's repositories.
  • Store remote copies of your repositories (github servers) as backup of your local copies.

HTML: Select multiple as dropdown

    <select name="select_box"  multiple>
        <option>123</option>
        <option>456</option>
        <option>789</option>
     </select>

How does functools partial do what it does?

short answer, partial gives default values to the parameters of a function that would otherwise not have default values.

from functools import partial

def foo(a,b):
    return a+b

bar = partial(foo, a=1) # equivalent to: foo(a=1, b)
bar(b=10)
#11 = 1+10
bar(a=101, b=10)
#111=101+10

Spring Boot Java Config Set Session Timeout

You should be able to set the server.session.timeout in your application.properties file.

ref: http://docs.spring.io/spring-boot/docs/1.4.x/reference/html/common-application-properties.html

C-like structures in Python

I think Python structure dictionary is suitable for this requirement.

d = dict{}
d[field1] = field1
d[field2] = field2
d[field2] = field3

Java: parse int value from a char

String element = "el5";
int x = element.charAt(2) - 48;

Subtracting ascii value of '0' = 48 from char

Python conversion from binary string to hexadecimal

>>> import string
>>> s="0000 0100 1000 1101"
>>> ''.join([ "%x"%string.atoi(bin,2) for bin in s.split() ]  )
'048d'
>>>

or

>>> s="0000 0100 1000 1101"
>>> hex(string.atoi(s.replace(" ",""),2))
'0x48d'

Datatables warning(table id = 'example'): cannot reinitialise data table

You can also destroy the old datatable by using the following code before creating the new datatable:

$("#example").dataTable().fnDestroy();

How to change the remote a branch is tracking?

You could either delete your current branch and do:

git branch --track local_branch remote_branch

Or change change remote server to the current one in the config

How can I add the new "Floating Action Button" between two widgets/layouts

here is working code.

i use appBarLayout to anchor my floatingActionButton. hope this might helpful.

XML CODE.

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

    <android.support.design.widget.AppBarLayout
        android:id="@+id/appbar"
        android:layout_height="192dp"
        android:layout_width="match_parent">

        <android.support.design.widget.CollapsingToolbarLayout
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            app:toolbarId="@+id/toolbar"
            app:titleEnabled="true"
            app:layout_scrollFlags="scroll|enterAlways|exitUntilCollapsed"
            android:id="@+id/collapsingbar"
            app:contentScrim="?attr/colorPrimary">

            <android.support.v7.widget.Toolbar
                app:layout_collapseMode="pin"
                android:id="@+id/toolbarItemDetailsView"
                android:layout_height="?attr/actionBarSize"
                android:layout_width="match_parent"></android.support.v7.widget.Toolbar>
        </android.support.design.widget.CollapsingToolbarLayout>
    </android.support.design.widget.AppBarLayout>

    <android.support.v4.widget.NestedScrollView
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        app:layout_behavior="android.support.design.widget.AppBarLayout$ScrollingViewBehavior">

        <android.support.constraint.ConstraintLayout
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            tools:context="com.example.rktech.myshoplist.Item_details_views">
            <RelativeLayout
                android:orientation="vertical"
                android:focusableInTouchMode="true"
                android:layout_width="match_parent"
                android:layout_height="match_parent">


                <!--Put Image here -->
                <ImageView
                    android:visibility="gone"
                    android:layout_marginTop="56dp"
                    android:layout_width="match_parent"
                    android:layout_height="230dp"
                    android:scaleType="centerCrop"
                    android:src="@drawable/third" />


                <ScrollView
                    android:layout_width="match_parent"
                    android:layout_height="match_parent">

                    <RelativeLayout
                        android:layout_width="match_parent"
                        android:layout_height="match_parent"
                        android:layout_gravity="center"
                        android:orientation="vertical">

                        <android.support.v7.widget.CardView
                            android:layout_width="match_parent"
                            android:layout_height="match_parent"
                            app:cardCornerRadius="4dp"
                            app:cardElevation="4dp"
                            app:cardMaxElevation="6dp"
                            app:cardUseCompatPadding="true">

                            <RelativeLayout
                                android:layout_width="match_parent"
                                android:layout_height="match_parent"
                                android:layout_margin="8dp"
                                android:padding="3dp">


                                <LinearLayout
                                    android:layout_width="match_parent"
                                    android:layout_height="match_parent"
                                    android:orientation="vertical">


                                    <TextView
                                        android:id="@+id/txtDetailItemTitle"
                                        style="@style/TextAppearance.AppCompat.Title"
                                        android:layout_width="match_parent"
                                        android:layout_height="wrap_content"
                                        android:layout_marginLeft="4dp"
                                        android:text="Title" />

                                    <LinearLayout
                                        android:layout_width="match_parent"
                                        android:layout_height="match_parent"
                                        android:layout_marginTop="8dp"
                                        android:orientation="horizontal">

                                        <TextView
                                            android:id="@+id/txtDetailItemSeller"
                                            style="@style/TextAppearance.AppCompat.Subhead"
                                            android:layout_width="wrap_content"
                                            android:layout_height="wrap_content"
                                            android:layout_marginLeft="4dp"
                                            android:layout_weight="1"
                                            android:text="Shope Name" />

                                        <TextView
                                            android:id="@+id/txtDetailItemDate"
                                            style="@style/TextAppearance.AppCompat.Subhead"
                                            android:layout_width="wrap_content"
                                            android:layout_height="wrap_content"
                                            android:layout_marginRight="4dp"
                                            android:gravity="right"
                                            android:text="Date" />


                                    </LinearLayout>

                                    <TextView
                                        android:id="@+id/txtDetailItemDescription"
                                        style="@style/TextAppearance.AppCompat.Medium"
                                        android:layout_width="match_parent"
                                        android:minLines="5"
                                        android:layout_height="wrap_content"
                                        android:layout_marginLeft="4dp"
                                        android:layout_marginTop="16dp"
                                        android:text="description" />

                                    <LinearLayout
                                        android:layout_width="match_parent"
                                        android:layout_height="wrap_content"
                                        android:layout_marginBottom="8dp"
                                        android:orientation="horizontal">

                                        <TextView
                                            android:id="@+id/txtDetailItemQty"
                                            style="@style/TextAppearance.AppCompat.Medium"
                                            android:layout_width="wrap_content"
                                            android:layout_height="wrap_content"
                                            android:layout_marginLeft="4dp"
                                            android:layout_weight="1"
                                            android:text="Qunatity" />

                                        <TextView
                                            android:id="@+id/txtDetailItemMessure"
                                            style="@style/TextAppearance.AppCompat.Medium"
                                            android:layout_width="wrap_content"
                                            android:layout_height="wrap_content"
                                            android:layout_marginRight="4dp"
                                            android:layout_weight="1"
                                            android:gravity="right"
                                            android:text="Messure in Gram" />
                                    </LinearLayout>


                                    <TextView
                                        android:id="@+id/txtDetailItemPrice"
                                        style="@style/TextAppearance.AppCompat.Headline"
                                        android:layout_width="match_parent"
                                        android:layout_height="wrap_content"
                                        android:layout_marginRight="4dp"
                                        android:layout_weight="1"
                                        android:gravity="right"
                                        android:text="Price" />
                                </LinearLayout>

                            </RelativeLayout>
                        </android.support.v7.widget.CardView>
                    </RelativeLayout>
                </ScrollView>
            </RelativeLayout>

        </android.support.constraint.ConstraintLayout>

    </android.support.v4.widget.NestedScrollView>

    <android.support.design.widget.FloatingActionButton
        android:layout_width="wrap_content"
        app:layout_anchor="@id/appbar"
        app:fabSize="normal"
        app:layout_anchorGravity="bottom|right|end"
        android:layout_marginEnd="@dimen/_6sdp"
        android:src="@drawable/ic_done_black_24dp"
        android:layout_height="wrap_content" />

</android.support.design.widget.CoordinatorLayout>

Now if you paste above code. you will see following result on your device. Result Image

CSS Outside Border

I shared two solutions depending on your needs:

<style type="text/css" ref="stylesheet">
  .border-inside-box {
    border: 1px solid black;
  }
  .border-inside-box-v1 {
    outline: 1px solid black; /* 'border-radius' not available */
  }
  .border-outside-box-v2 {
    box-shadow: 0 0 0 1px black; /* 'border-style' not available (dashed, solid, etc) */
  }
</style>

example: https://codepen.io/danieldd/pen/gObEYKj

how to avoid extra blank page at end while printing?

Chrome seems to have a bug where in certain situations, hiding elements post-load with display:none, leaves a lot of extra space behind. I would guess they are calculating document height before the document is done rendering. Chrome also fires 2 media change events, and doesn't support onbeforeprint, etc. They are basically being the ie of printing. Here's my workaround:

@media print {
    body {
        display: none;
    }
}

body.printing {
    display: block;
}

You give body class="printing" on doc ready, and that enables the print styles. This system allows for modularization of print styles, and in-browser print preview.

IE throws JavaScript Error: The value of the property 'googleMapsQuery' is null or undefined, not a Function object (works in other browsers)

I found the answer, and in spite of what I reported, it was NOT browser specific. The bug was in my function code, and would have occurred in any browser. It boils down to this. I had two lines in my code that were FireFox/FireBug specific. They used console.log. In IE, they threw an error, so I commented them out (or so I thought). I did a crappy job commenting them out, and broke the bracketing in my function.

Original Code (with console.log in it):

if (sxti.length <= 50) console.log('sxti=' + sxti);
if (sxph.length <= 50) console.log('sxph=' + sxph);

Broken Code (misplaced brackets inside comments):

if (sxti.length <= 50) { //console.log('sxti=' + sxti); }
if (sxph.length <= 50) { //console.log('sxph=' + sxph); }

Fixed Code (fixed brackets outside comments):

if (sxti.length <= 50) { }//console.log('sxti=' + sxti);
if (sxph.length <= 50) { }//console.log('sxph=' + sxph);

So, it was my own sloppy coding. The function really wasn't defined, because a syntax error kept it from being closed.

Oh well, live and learn. ;)

Arrays.fill with multidimensional array in Java

As an extension to the answer, I found this post but was looking to fill a 4 dimensional array. The original example is only a two dimensional array, but the question says "multidimensional". I didn't want to post a new question for this...

You can use the same method, but you have to nest them so that you eventually get to a single dimensional array.

fourDArray = new float[10][10][10][1];
// Fill each row with null
for (float[][][] row: fourDArray)
{
    for (float[][] innerRow: row)
    {
        for (float[] innerInnerRow: innerRow)
        {
        Arrays.fill(innerInnerRow, -1000);
        }
    }
};

Auto-loading lib files in Rails 4

Use config.to_prepare to load you monkey patches/extensions for every request in development mode.

config.to_prepare do |action_dispatcher|
 # More importantly, will run upon every request in development, but only once (during boot-up) in production and test.
 Rails.logger.info "\n--- Loading extensions for #{self.class} "
 Dir.glob("#{Rails.root}/lib/extensions/**/*.rb").sort.each do |entry|
   Rails.logger.info "Loading extension(s): #{entry}"
   require_dependency "#{entry}"
 end
 Rails.logger.info "--- Loaded extensions for #{self.class}\n"

end

How to use setprecision in C++

#include <iomanip>
#include <iostream>

int main()
{
    double num1 = 3.12345678;
    std::cout << std::fixed << std::showpoint;
    std::cout << std::setprecision(2);
    std::cout << num1 << std::endl;
    return 0;
}

How to download a file with Node.js (without using third-party libraries)?

var fs = require('fs'),
    request = require('request');

var download = function(uri, filename, callback){
    request.head(uri, function(err, res, body){
    console.log('content-type:', res.headers['content-type']);
    console.log('content-length:', res.headers['content-length']);
    request(uri).pipe(fs.createWriteStream(filename)).on('close', callback);

    }); 
};   

download('https://www.cryptocompare.com/media/19684/doge.png', 'icons/taskks12.png', function(){
    console.log('done');
});

Java equivalent to #region in C#

In Eclipse you can collapse the brackets wrapping variable region block. The closest is to do something like this:

public class counter_class 
{ 

    { // Region

        int variable = 0;

    }
}

Error when using scp command "bash: scp: command not found"

Check if scp is installed or not on from where you want want to copy check using which scp

If it's already installed, it will print you a path like /usr/bin/scp Else, install scp using:

yum -y install openssh-clients

Then copy command

scp -r [email protected]:/var/www/html/database_backup/restore_fullbackup/backup_20140308-023002.sql  /var/www/html/db_bkp/

How can I make a jQuery UI 'draggable()' div draggable for touchscreen?

I was struggling with a similar problem yesterday. I already had a "working" solution using jQuery UI's draggable together with jQuery Touch Punch, which are mentioned in other answers. However, using this method was causing weird bugs in some Android devices for me, and therefore I decided to write a small jQuery plugin that can make HTML elements draggable by using touch events instead of using a method that emulates fake mouse events.

The result of this is jQuery Draggable Touch which is a simple jQuery plugin for making elements draggable, that has touch devices as it's main target by using touch events (like touchstart, touchmove, touchend, etc.). It still has a fallback that uses mouse events if the browser/device doesn't support touch events.

How do I open the "front camera" on the Android platform?

To open the back camera:-

val cameraIntent = Intent(MediaStore.ACTION_IMAGE_CAPTURE)
startActivityForResult(cameraIntent, REQUEST_CODE_CAMERA)

To open the front camera:-

val cameraIntent = Intent(MediaStore.ACTION_IMAGE_CAPTURE)
when {
     Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP_MR1 && Build.VERSION.SDK_INT < Build.VERSION_CODES.O -> {
         cameraIntent.putExtra("android.intent.extras.CAMERA_FACING", CameraCharacteristics.LENS_FACING_FRONT)  // Tested on API 24 Android version 7.0(Samsung S6)
     }
     Build.VERSION.SDK_INT >= Build.VERSION_CODES.O -> {
         cameraIntent.putExtra("android.intent.extras.CAMERA_FACING", CameraCharacteristics.LENS_FACING_FRONT) // Tested on API 27 Android version 8.0(Nexus 6P)
         cameraIntent.putExtra("android.intent.extra.USE_FRONT_CAMERA", true)
     }
     else -> cameraIntent.putExtra("android.intent.extras.CAMERA_FACING", 1)  // Tested API 21 Android version 5.0.1(Samsung S4)
}
startActivityForResult(cameraIntent, REQUEST_CODE_CAMERA)

I could not make it work for API 28 and above. Also, opening the front camera directly is not possible in some devices(depends on the manufacturer).

How to convert text column to datetime in SQL

Use convert with style 101.

select convert(datetime, Remarks, 101)

If your column is really text you need to convert to varchar before converting to datetime

select convert(datetime, convert(varchar(30), Remarks), 101)

How to subtract 30 days from the current datetime in mysql?

If you only need the date and not the time use:

select*from table where exec_datetime
between subdate(curdate(), 30)and curdate();

Since curdate() omits the time component, it's potentially faster than now() and more "semantically correct" in cases where you're only interested in the date.

Also, subdate()'s 2-arity overload is potentially faster than using interval. interval is meant to be for cases when you need a non-day component.

Is a Python list guaranteed to have its elements stay in the order they are inserted in?

Yes, the order of elements in a python list is persistent.

How do a LDAP search/authenticate against this LDAP in Java

You can also use the following code :

package com.agileinfotech.bsviewer.ldap;

import java.util.Hashtable;
import java.util.ResourceBundle;

import javax.naming.Context;
import javax.naming.NamingException;
import javax.naming.directory.DirContext;
import javax.naming.directory.InitialDirContext;

public class LDAPLoginAuthentication {
    public LDAPLoginAuthentication() {
        // TODO Auto-generated constructor
    }

    ResourceBundle resBundle = ResourceBundle.getBundle("settings");

    @SuppressWarnings("unchecked")
    public String authenticateUser(String username, String password) {
        String strUrl = "success";
        Hashtable env = new Hashtable(11);
        boolean b = false;
        String Securityprinciple = "cn=" + username + "," + resBundle.getString("UserSearch");
        env.put(Context.INITIAL_CONTEXT_FACTORY, resBundle.getString("InitialContextFactory"));
        env.put(Context.PROVIDER_URL, resBundle.getString("Provider_url"));
        env.put(Context.SECURITY_AUTHENTICATION, "simple");
        env.put(Context.SECURITY_PRINCIPAL, Securityprinciple);
        env.put(Context.SECURITY_CREDENTIALS, password);

        try {
            // Create initial context
            DirContext ctx = new InitialDirContext(env);
            // Close the context when we're done
            b = true;
            ctx.close();

        } catch (NamingException e) {
            b = false;
        } finally {
            if (b) {
                strUrl = "success";
            } else {
                strUrl = "failer";
            }
        }
        return strUrl;
    }
}

Apache Tomcat Not Showing in Eclipse Server Runtime Environments

nor does it appear in the list of environments that can be added when I click the "Add" button. All I see is the J2EE Runtime Library.

Go get "Eclipse for Java EE developers". Note the extra "EE". This includes among others the Web Tools Platform with among others a lot of server plugins with among others the one for Apache Tomcat 5.x. It's also logically; JSP/Servlet is part of the Java EE API.

Converting list to *args when calling function

yes, using *arg passing args to a function will make python unpack the values in arg and pass it to the function.

so:

>>> def printer(*args):
 print args


>>> printer(2,3,4)
(2, 3, 4)
>>> printer(*range(2, 5))
(2, 3, 4)
>>> printer(range(2, 5))
([2, 3, 4],)
>>> 

Correct way to populate an Array with a Range in Ruby

Sounds like you're doing this:

0..10.to_a

The warning is from Fixnum#to_a, not from Range#to_a. Try this instead:

(0..10).to_a

How to git ignore subfolders / subdirectories?

To exclude content and subdirectories:

**/bin/*

To just exclude all subdirectories but take the content, add "/":

**/bin/*/

html text input onchange event

When I'm doing something like this I use the onKeyUp event.

<script type="text/javascript">
 function bar() {
      //do stuff
 }
<input type="text" name="foo" onKeyUp="return bar()" />

but if you don't want to use an HTML event you could try to use jQuerys .change() method

$('.target').change(function() {
   //do stuff
});

in this example, the input would have to have a class "target"

if you're going to have multiple text boxes that you want to have done the same thing when their text is changed and you need their data then you could do this:

$('.target').change(function(event) {
   //do stuff with the "event" object as the object that called the method
)};

that way you can use the same code, for multiple text boxes using the same class without having to rewrite any code.

Push item to associative array in PHP

$new_input = array('type' => 'text', 'label' => 'First name', 'show' => true, 'required' => true);
$options['inputs']['name'] = $new_input;

How to store Query Result in variable using mysql

Additionally, if you want to set multiple variables at once by one query, you can use the other syntax for setting variables which goes like this: SELECT @varname:=value.

A practical example:

SELECT @total_count:=COUNT(*), @total_price:=SUM(quantity*price) FROM items ...

MySQL : ERROR 1215 (HY000): Cannot add foreign key constraint

It is also possible to get this error if the foreign key is not a primary key within its own table.

I did an ALTER TABLE and accidentally removed the primary key status of a column, and got this error.

How to create a numeric vector of zero length in R

Simply:

x <- vector(mode="numeric", length=0)

How to insert table values from one database to another database?

For SQL Server, you can use tool Import Data from another Database, It's easier to configuration mapping columns.

How to Use -confirm in PowerShell

This is a simple loop that keeps prompting unless the user selects 'y' or 'n'

$confirmation = Read-Host "Ready? [y/n]"
while($confirmation -ne "y")
{
    if ($confirmation -eq 'n') {exit}
    $confirmation = Read-Host "Ready? [y/n]"
}

How to send FormData objects with Ajax-requests in jQuery?

I believe you could do it like this :

var fd = new FormData();    
fd.append( 'file', input.files[0] );

$.ajax({
  url: 'http://example.com/script.php',
  data: fd,
  processData: false,
  contentType: false,
  type: 'POST',
  success: function(data){
    alert(data);
  }
});

Notes:

  • Setting processData to false lets you prevent jQuery from automatically transforming the data into a query string. See the docs for more info.

  • Setting the contentType to false is imperative, since otherwise jQuery will set it incorrectly.

When is the init() function run?

Take for example a framework or a library you're designing for other users, these users eventually will have a main function in their code in order to execute their app. If the user directly imports a sub-package of your library's project then the init of that sub-package will be called(once) first of all. The same for the root package of the library, etc...

There are many times when you may want a code block to be executed without the existence of a main func, directly or not.

If you, as the developer of the imaginary library, import your library's sub-package that has an init function, it will be called first and once, you don't have a main func but you need to make sure that some variables, or a table, will be initialized before the calls of other functions.

A good thing to remember and not to worry about, is that: the init always execute once per application.

init execution happens:

  1. right before the init function of the "caller" package,
  2. before the, optionally, main func,
  3. but after the package-level variables, var = [...] or cost = [...],

When you import a package it will run all of its init functions, by order.

I'll will give a very good example of an init function. It will add mime types to a standard go's library named mime and a package-level function will use the mime standard package directly to get the custom mime types that are already be initialized at its init function:

package mime

import (
    "mime"
    "path/filepath"
)

var types = map[string]string{
    ".3dm":       "x-world/x-3dmf",
    ".3dmf":      "x-world/x-3dmf",
    ".7z":        "application/x-7z-compressed",
    ".a":         "application/octet-stream",
    ".aab":       "application/x-authorware-bin",
    ".aam":       "application/x-authorware-map",
    ".aas":       "application/x-authorware-seg",
    ".abc":       "text/vndabc",
    ".ace":       "application/x-ace-compressed",
    ".acgi":      "text/html",
    ".afl":       "video/animaflex",
    ".ai":        "application/postscript",
    ".aif":       "audio/aiff",
    ".aifc":      "audio/aiff",
    ".aiff":      "audio/aiff",
    ".aim":       "application/x-aim",
    ".aip":       "text/x-audiosoft-intra",
    ".alz":       "application/x-alz-compressed",
    ".ani":       "application/x-navi-animation",
    ".aos":       "application/x-nokia-9000-communicator-add-on-software",
    ".aps":       "application/mime",
    ".apk":       "application/vnd.android.package-archive",
    ".arc":       "application/x-arc-compressed",
    ".arj":       "application/arj",
    ".art":       "image/x-jg",
    ".asf":       "video/x-ms-asf",
    ".asm":       "text/x-asm",
    ".asp":       "text/asp",
    ".asx":       "application/x-mplayer2",
    ".au":        "audio/basic",
    ".avi":       "video/x-msvideo",
    ".avs":       "video/avs-video",
    ".bcpio":     "application/x-bcpio",
    ".bin":       "application/mac-binary",
    ".bmp":       "image/bmp",
    ".boo":       "application/book",
    ".book":      "application/book",
    ".boz":       "application/x-bzip2",
    ".bsh":       "application/x-bsh",
    ".bz2":       "application/x-bzip2",
    ".bz":        "application/x-bzip",
    ".c++":       "text/plain",
    ".c":         "text/x-c",
    ".cab":       "application/vnd.ms-cab-compressed",
    ".cat":       "application/vndms-pkiseccat",
    ".cc":        "text/x-c",
    ".ccad":      "application/clariscad",
    ".cco":       "application/x-cocoa",
    ".cdf":       "application/cdf",
    ".cer":       "application/pkix-cert",
    ".cha":       "application/x-chat",
    ".chat":      "application/x-chat",
    ".chrt":      "application/vnd.kde.kchart",
    ".class":     "application/java",
    ".com":       "text/plain",
    ".conf":      "text/plain",
    ".cpio":      "application/x-cpio",
    ".cpp":       "text/x-c",
    ".cpt":       "application/mac-compactpro",
    ".crl":       "application/pkcs-crl",
    ".crt":       "application/pkix-cert",
    ".crx":       "application/x-chrome-extension",
    ".csh":       "text/x-scriptcsh",
    ".css":       "text/css",
    ".csv":       "text/csv",
    ".cxx":       "text/plain",
    ".dar":       "application/x-dar",
    ".dcr":       "application/x-director",
    ".deb":       "application/x-debian-package",
    ".deepv":     "application/x-deepv",
    ".def":       "text/plain",
    ".der":       "application/x-x509-ca-cert",
    ".dif":       "video/x-dv",
    ".dir":       "application/x-director",
    ".divx":      "video/divx",
    ".dl":        "video/dl",
    ".dmg":       "application/x-apple-diskimage",
    ".doc":       "application/msword",
    ".dot":       "application/msword",
    ".dp":        "application/commonground",
    ".drw":       "application/drafting",
    ".dump":      "application/octet-stream",
    ".dv":        "video/x-dv",
    ".dvi":       "application/x-dvi",
    ".dwf":       "drawing/x-dwf=(old)",
    ".dwg":       "application/acad",
    ".dxf":       "application/dxf",
    ".dxr":       "application/x-director",
    ".el":        "text/x-scriptelisp",
    ".elc":       "application/x-bytecodeelisp=(compiled=elisp)",
    ".eml":       "message/rfc822",
    ".env":       "application/x-envoy",
    ".eps":       "application/postscript",
    ".es":        "application/x-esrehber",
    ".etx":       "text/x-setext",
    ".evy":       "application/envoy",
    ".exe":       "application/octet-stream",
    ".f77":       "text/x-fortran",
    ".f90":       "text/x-fortran",
    ".f":         "text/x-fortran",
    ".fdf":       "application/vndfdf",
    ".fif":       "application/fractals",
    ".fli":       "video/fli",
    ".flo":       "image/florian",
    ".flv":       "video/x-flv",
    ".flx":       "text/vndfmiflexstor",
    ".fmf":       "video/x-atomic3d-feature",
    ".for":       "text/x-fortran",
    ".fpx":       "image/vndfpx",
    ".frl":       "application/freeloader",
    ".funk":      "audio/make",
    ".g3":        "image/g3fax",
    ".g":         "text/plain",
    ".gif":       "image/gif",
    ".gl":        "video/gl",
    ".gsd":       "audio/x-gsm",
    ".gsm":       "audio/x-gsm",
    ".gsp":       "application/x-gsp",
    ".gss":       "application/x-gss",
    ".gtar":      "application/x-gtar",
    ".gz":        "application/x-compressed",
    ".gzip":      "application/x-gzip",
    ".h":         "text/x-h",
    ".hdf":       "application/x-hdf",
    ".help":      "application/x-helpfile",
    ".hgl":       "application/vndhp-hpgl",
    ".hh":        "text/x-h",
    ".hlb":       "text/x-script",
    ".hlp":       "application/hlp",
    ".hpg":       "application/vndhp-hpgl",
    ".hpgl":      "application/vndhp-hpgl",
    ".hqx":       "application/binhex",
    ".hta":       "application/hta",
    ".htc":       "text/x-component",
    ".htm":       "text/html",
    ".html":      "text/html",
    ".htmls":     "text/html",
    ".htt":       "text/webviewhtml",
    ".htx":       "text/html",
    ".ice":       "x-conference/x-cooltalk",
    ".ico":       "image/x-icon",
    ".ics":       "text/calendar",
    ".icz":       "text/calendar",
    ".idc":       "text/plain",
    ".ief":       "image/ief",
    ".iefs":      "image/ief",
    ".iges":      "application/iges",
    ".igs":       "application/iges",
    ".ima":       "application/x-ima",
    ".imap":      "application/x-httpd-imap",
    ".inf":       "application/inf",
    ".ins":       "application/x-internett-signup",
    ".ip":        "application/x-ip2",
    ".isu":       "video/x-isvideo",
    ".it":        "audio/it",
    ".iv":        "application/x-inventor",
    ".ivr":       "i-world/i-vrml",
    ".ivy":       "application/x-livescreen",
    ".jam":       "audio/x-jam",
    ".jav":       "text/x-java-source",
    ".java":      "text/x-java-source",
    ".jcm":       "application/x-java-commerce",
    ".jfif-tbnl": "image/jpeg",
    ".jfif":      "image/jpeg",
    ".jnlp":      "application/x-java-jnlp-file",
    ".jpe":       "image/jpeg",
    ".jpeg":      "image/jpeg",
    ".jpg":       "image/jpeg",
    ".jps":       "image/x-jps",
    ".js":        "application/javascript",
    ".json":      "application/json",
    ".jut":       "image/jutvision",
    ".kar":       "audio/midi",
    ".karbon":    "application/vnd.kde.karbon",
    ".kfo":       "application/vnd.kde.kformula",
    ".flw":       "application/vnd.kde.kivio",
    ".kml":       "application/vnd.google-earth.kml+xml",
    ".kmz":       "application/vnd.google-earth.kmz",
    ".kon":       "application/vnd.kde.kontour",
    ".kpr":       "application/vnd.kde.kpresenter",
    ".kpt":       "application/vnd.kde.kpresenter",
    ".ksp":       "application/vnd.kde.kspread",
    ".kwd":       "application/vnd.kde.kword",
    ".kwt":       "application/vnd.kde.kword",
    ".ksh":       "text/x-scriptksh",
    ".la":        "audio/nspaudio",
    ".lam":       "audio/x-liveaudio",
    ".latex":     "application/x-latex",
    ".lha":       "application/lha",
    ".lhx":       "application/octet-stream",
    ".list":      "text/plain",
    ".lma":       "audio/nspaudio",
    ".log":       "text/plain",
    ".lsp":       "text/x-scriptlisp",
    ".lst":       "text/plain",
    ".lsx":       "text/x-la-asf",
    ".ltx":       "application/x-latex",
    ".lzh":       "application/octet-stream",
    ".lzx":       "application/lzx",
    ".m1v":       "video/mpeg",
    ".m2a":       "audio/mpeg",
    ".m2v":       "video/mpeg",
    ".m3u":       "audio/x-mpegurl",
    ".m":         "text/x-m",
    ".man":       "application/x-troff-man",
    ".manifest":  "text/cache-manifest",
    ".map":       "application/x-navimap",
    ".mar":       "text/plain",
    ".mbd":       "application/mbedlet",
    ".mc$":       "application/x-magic-cap-package-10",
    ".mcd":       "application/mcad",
    ".mcf":       "text/mcf",
    ".mcp":       "application/netmc",
    ".me":        "application/x-troff-me",
    ".mht":       "message/rfc822",
    ".mhtml":     "message/rfc822",
    ".mid":       "application/x-midi",
    ".midi":      "application/x-midi",
    ".mif":       "application/x-frame",
    ".mime":      "message/rfc822",
    ".mjf":       "audio/x-vndaudioexplosionmjuicemediafile",
    ".mjpg":      "video/x-motion-jpeg",
    ".mm":        "application/base64",
    ".mme":       "application/base64",
    ".mod":       "audio/mod",
    ".moov":      "video/quicktime",
    ".mov":       "video/quicktime",
    ".movie":     "video/x-sgi-movie",
    ".mp2":       "audio/mpeg",
    ".mp3":       "audio/mpeg3",
    ".mp4":       "video/mp4",
    ".mpa":       "audio/mpeg",
    ".mpc":       "application/x-project",
    ".mpe":       "video/mpeg",
    ".mpeg":      "video/mpeg",
    ".mpg":       "video/mpeg",
    ".mpga":      "audio/mpeg",
    ".mpp":       "application/vndms-project",
    ".mpt":       "application/x-project",
    ".mpv":       "application/x-project",
    ".mpx":       "application/x-project",
    ".mrc":       "application/marc",
    ".ms":        "application/x-troff-ms",
    ".mv":        "video/x-sgi-movie",
    ".my":        "audio/make",
    ".mzz":       "application/x-vndaudioexplosionmzz",
    ".nap":       "image/naplps",
    ".naplps":    "image/naplps",
    ".nc":        "application/x-netcdf",
    ".ncm":       "application/vndnokiaconfiguration-message",
    ".nif":       "image/x-niff",
    ".niff":      "image/x-niff",
    ".nix":       "application/x-mix-transfer",
    ".nsc":       "application/x-conference",
    ".nvd":       "application/x-navidoc",
    ".o":         "application/octet-stream",
    ".oda":       "application/oda",
    ".odb":       "application/vnd.oasis.opendocument.database",
    ".odc":       "application/vnd.oasis.opendocument.chart",
    ".odf":       "application/vnd.oasis.opendocument.formula",
    ".odg":       "application/vnd.oasis.opendocument.graphics",
    ".odi":       "application/vnd.oasis.opendocument.image",
    ".odm":       "application/vnd.oasis.opendocument.text-master",
    ".odp":       "application/vnd.oasis.opendocument.presentation",
    ".ods":       "application/vnd.oasis.opendocument.spreadsheet",
    ".odt":       "application/vnd.oasis.opendocument.text",
    ".oga":       "audio/ogg",
    ".ogg":       "audio/ogg",
    ".ogv":       "video/ogg",
    ".omc":       "application/x-omc",
    ".omcd":      "application/x-omcdatamaker",
    ".omcr":      "application/x-omcregerator",
    ".otc":       "application/vnd.oasis.opendocument.chart-template",
    ".otf":       "application/vnd.oasis.opendocument.formula-template",
    ".otg":       "application/vnd.oasis.opendocument.graphics-template",
    ".oth":       "application/vnd.oasis.opendocument.text-web",
    ".oti":       "application/vnd.oasis.opendocument.image-template",
    ".otm":       "application/vnd.oasis.opendocument.text-master",
    ".otp":       "application/vnd.oasis.opendocument.presentation-template",
    ".ots":       "application/vnd.oasis.opendocument.spreadsheet-template",
    ".ott":       "application/vnd.oasis.opendocument.text-template",
    ".p10":       "application/pkcs10",
    ".p12":       "application/pkcs-12",
    ".p7a":       "application/x-pkcs7-signature",
    ".p7c":       "application/pkcs7-mime",
    ".p7m":       "application/pkcs7-mime",
    ".p7r":       "application/x-pkcs7-certreqresp",
    ".p7s":       "application/pkcs7-signature",
    ".p":         "text/x-pascal",
    ".part":      "application/pro_eng",
    ".pas":       "text/pascal",
    ".pbm":       "image/x-portable-bitmap",
    ".pcl":       "application/vndhp-pcl",
    ".pct":       "image/x-pict",
    ".pcx":       "image/x-pcx",
    ".pdb":       "chemical/x-pdb",
    ".pdf":       "application/pdf",
    ".pfunk":     "audio/make",
    ".pgm":       "image/x-portable-graymap",
    ".pic":       "image/pict",
    ".pict":      "image/pict",
    ".pkg":       "application/x-newton-compatible-pkg",
    ".pko":       "application/vndms-pkipko",
    ".pl":        "text/x-scriptperl",
    ".plx":       "application/x-pixclscript",
    ".pm4":       "application/x-pagemaker",
    ".pm5":       "application/x-pagemaker",
    ".pm":        "text/x-scriptperl-module",
    ".png":       "image/png",
    ".pnm":       "application/x-portable-anymap",
    ".pot":       "application/mspowerpoint",
    ".pov":       "model/x-pov",
    ".ppa":       "application/vndms-powerpoint",
    ".ppm":       "image/x-portable-pixmap",
    ".pps":       "application/mspowerpoint",
    ".ppt":       "application/mspowerpoint",
    ".ppz":       "application/mspowerpoint",
    ".pre":       "application/x-freelance",
    ".prt":       "application/pro_eng",
    ".ps":        "application/postscript",
    ".psd":       "application/octet-stream",
    ".pvu":       "paleovu/x-pv",
    ".pwz":       "application/vndms-powerpoint",
    ".py":        "text/x-scriptphyton",
    ".pyc":       "application/x-bytecodepython",
    ".qcp":       "audio/vndqcelp",
    ".qd3":       "x-world/x-3dmf",
    ".qd3d":      "x-world/x-3dmf",
    ".qif":       "image/x-quicktime",
    ".qt":        "video/quicktime",
    ".qtc":       "video/x-qtc",
    ".qti":       "image/x-quicktime",
    ".qtif":      "image/x-quicktime",
    ".ra":        "audio/x-pn-realaudio",
    ".ram":       "audio/x-pn-realaudio",
    ".rar":       "application/x-rar-compressed",
    ".ras":       "application/x-cmu-raster",
    ".rast":      "image/cmu-raster",
    ".rexx":      "text/x-scriptrexx",
    ".rf":        "image/vndrn-realflash",
    ".rgb":       "image/x-rgb",
    ".rm":        "application/vndrn-realmedia",
    ".rmi":       "audio/mid",
    ".rmm":       "audio/x-pn-realaudio",
    ".rmp":       "audio/x-pn-realaudio",
    ".rng":       "application/ringing-tones",
    ".rnx":       "application/vndrn-realplayer",
    ".roff":      "application/x-troff",
    ".rp":        "image/vndrn-realpix",
    ".rpm":       "audio/x-pn-realaudio-plugin",
    ".rt":        "text/vndrn-realtext",
    ".rtf":       "text/richtext",
    ".rtx":       "text/richtext",
    ".rv":        "video/vndrn-realvideo",
    ".s":         "text/x-asm",
    ".s3m":       "audio/s3m",
    ".s7z":       "application/x-7z-compressed",
    ".saveme":    "application/octet-stream",
    ".sbk":       "application/x-tbook",
    ".scm":       "text/x-scriptscheme",
    ".sdml":      "text/plain",
    ".sdp":       "application/sdp",
    ".sdr":       "application/sounder",
    ".sea":       "application/sea",
    ".set":       "application/set",
    ".sgm":       "text/x-sgml",
    ".sgml":      "text/x-sgml",
    ".sh":        "text/x-scriptsh",
    ".shar":      "application/x-bsh",
    ".shtml":     "text/x-server-parsed-html",
    ".sid":       "audio/x-psid",
    ".skd":       "application/x-koan",
    ".skm":       "application/x-koan",
    ".skp":       "application/x-koan",
    ".skt":       "application/x-koan",
    ".sit":       "application/x-stuffit",
    ".sitx":      "application/x-stuffitx",
    ".sl":        "application/x-seelogo",
    ".smi":       "application/smil",
    ".smil":      "application/smil",
    ".snd":       "audio/basic",
    ".sol":       "application/solids",
    ".spc":       "text/x-speech",
    ".spl":       "application/futuresplash",
    ".spr":       "application/x-sprite",
    ".sprite":    "application/x-sprite",
    ".spx":       "audio/ogg",
    ".src":       "application/x-wais-source",
    ".ssi":       "text/x-server-parsed-html",
    ".ssm":       "application/streamingmedia",
    ".sst":       "application/vndms-pkicertstore",
    ".step":      "application/step",
    ".stl":       "application/sla",
    ".stp":       "application/step",
    ".sv4cpio":   "application/x-sv4cpio",
    ".sv4crc":    "application/x-sv4crc",
    ".svf":       "image/vnddwg",
    ".svg":       "image/svg+xml",
    ".svr":       "application/x-world",
    ".swf":       "application/x-shockwave-flash",
    ".t":         "application/x-troff",
    ".talk":      "text/x-speech",
    ".tar":       "application/x-tar",
    ".tbk":       "application/toolbook",
    ".tcl":       "text/x-scripttcl",
    ".tcsh":      "text/x-scripttcsh",
    ".tex":       "application/x-tex",
    ".texi":      "application/x-texinfo",
    ".texinfo":   "application/x-texinfo",
    ".text":      "text/plain",
    ".tgz":       "application/gnutar",
    ".tif":       "image/tiff",
    ".tiff":      "image/tiff",
    ".tr":        "application/x-troff",
    ".tsi":       "audio/tsp-audio",
    ".tsp":       "application/dsptype",
    ".tsv":       "text/tab-separated-values",
    ".turbot":    "image/florian",
    ".txt":       "text/plain",
    ".uil":       "text/x-uil",
    ".uni":       "text/uri-list",
    ".unis":      "text/uri-list",
    ".unv":       "application/i-deas",
    ".uri":       "text/uri-list",
    ".uris":      "text/uri-list",
    ".ustar":     "application/x-ustar",
    ".uu":        "text/x-uuencode",
    ".uue":       "text/x-uuencode",
    ".vcd":       "application/x-cdlink",
    ".vcf":       "text/x-vcard",
    ".vcard":     "text/x-vcard",
    ".vcs":       "text/x-vcalendar",
    ".vda":       "application/vda",
    ".vdo":       "video/vdo",
    ".vew":       "application/groupwise",
    ".viv":       "video/vivo",
    ".vivo":      "video/vivo",
    ".vmd":       "application/vocaltec-media-desc",
    ".vmf":       "application/vocaltec-media-file",
    ".voc":       "audio/voc",
    ".vos":       "video/vosaic",
    ".vox":       "audio/voxware",
    ".vqe":       "audio/x-twinvq-plugin",
    ".vqf":       "audio/x-twinvq",
    ".vql":       "audio/x-twinvq-plugin",
    ".vrml":      "application/x-vrml",
    ".vrt":       "x-world/x-vrt",
    ".vsd":       "application/x-visio",
    ".vst":       "application/x-visio",
    ".vsw":       "application/x-visio",
    ".w60":       "application/wordperfect60",
    ".w61":       "application/wordperfect61",
    ".w6w":       "application/msword",
    ".wav":       "audio/wav",
    ".wb1":       "application/x-qpro",
    ".wbmp":      "image/vnd.wap.wbmp",
    ".web":       "application/vndxara",
    ".wiz":       "application/msword",
    ".wk1":       "application/x-123",
    ".wmf":       "windows/metafile",
    ".wml":       "text/vnd.wap.wml",
    ".wmlc":      "application/vnd.wap.wmlc",
    ".wmls":      "text/vnd.wap.wmlscript",
    ".wmlsc":     "application/vnd.wap.wmlscriptc",
    ".word":      "application/msword",
    ".wp5":       "application/wordperfect",
    ".wp6":       "application/wordperfect",
    ".wp":        "application/wordperfect",
    ".wpd":       "application/wordperfect",
    ".wq1":       "application/x-lotus",
    ".wri":       "application/mswrite",
    ".wrl":       "application/x-world",
    ".wrz":       "model/vrml",
    ".wsc":       "text/scriplet",
    ".wsrc":      "application/x-wais-source",
    ".wtk":       "application/x-wintalk",
    ".x-png":     "image/png",
    ".xbm":       "image/x-xbitmap",
    ".xdr":       "video/x-amt-demorun",
    ".xgz":       "xgl/drawing",
    ".xif":       "image/vndxiff",
    ".xl":        "application/excel",
    ".xla":       "application/excel",
    ".xlb":       "application/excel",
    ".xlc":       "application/excel",
    ".xld":       "application/excel",
    ".xlk":       "application/excel",
    ".xll":       "application/excel",
    ".xlm":       "application/excel",
    ".xls":       "application/excel",
    ".xlt":       "application/excel",
    ".xlv":       "application/excel",
    ".xlw":       "application/excel",
    ".xm":        "audio/xm",
    ".xml":       "text/xml",
    ".xmz":       "xgl/movie",
    ".xpix":      "application/x-vndls-xpix",
    ".xpm":       "image/x-xpixmap",
    ".xsr":       "video/x-amt-showrun",
    ".xwd":       "image/x-xwd",
    ".xyz":       "chemical/x-pdb",
    ".z":         "application/x-compress",
    ".zip":       "application/zip",
    ".zoo":       "application/octet-stream",
    ".zsh":       "text/x-scriptzsh",
    ".docx":      "application/vnd.openxmlformats-officedocument.wordprocessingml.document",
    ".docm":      "application/vnd.ms-word.document.macroEnabled.12",
    ".dotx":      "application/vnd.openxmlformats-officedocument.wordprocessingml.template",
    ".dotm":      "application/vnd.ms-word.template.macroEnabled.12",
    ".xlsx":      "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet",
    ".xlsm":      "application/vnd.ms-excel.sheet.macroEnabled.12",
    ".xltx":      "application/vnd.openxmlformats-officedocument.spreadsheetml.template",
    ".xltm":      "application/vnd.ms-excel.template.macroEnabled.12",
    ".xlsb":      "application/vnd.ms-excel.sheet.binary.macroEnabled.12",
    ".xlam":      "application/vnd.ms-excel.addin.macroEnabled.12",
    ".pptx":      "application/vnd.openxmlformats-officedocument.presentationml.presentation",
    ".pptm":      "application/vnd.ms-powerpoint.presentation.macroEnabled.12",
    ".ppsx":      "application/vnd.openxmlformats-officedocument.presentationml.slideshow",
    ".ppsm":      "application/vnd.ms-powerpoint.slideshow.macroEnabled.12",
    ".potx":      "application/vnd.openxmlformats-officedocument.presentationml.template",
    ".potm":      "application/vnd.ms-powerpoint.template.macroEnabled.12",
    ".ppam":      "application/vnd.ms-powerpoint.addin.macroEnabled.12",
    ".sldx":      "application/vnd.openxmlformats-officedocument.presentationml.slide",
    ".sldm":      "application/vnd.ms-powerpoint.slide.macroEnabled.12",
    ".thmx":      "application/vnd.ms-officetheme",
    ".onetoc":    "application/onenote",
    ".onetoc2":   "application/onenote",
    ".onetmp":    "application/onenote",
    ".onepkg":    "application/onenote",
    ".xpi":       "application/x-xpinstall",
}

func init() {
    for ext, typ := range types {
        // skip errors
        mime.AddExtensionType(ext, typ)
    }
}

// typeByExtension returns the MIME type associated with the file extension ext.
// The extension ext should begin with a leading dot, as in ".html".
// When ext has no associated type, typeByExtension returns "".
//
// Extensions are looked up first case-sensitively, then case-insensitively.
//
// The built-in table is small but on unix it is augmented by the local
// system's mime.types file(s) if available under one or more of these
// names:
//
//   /etc/mime.types
//   /etc/apache2/mime.types
//   /etc/apache/mime.types
//
// On Windows, MIME types are extracted from the registry.
//
// Text types have the charset parameter set to "utf-8" by default.
func TypeByExtension(fullfilename string) string {
    ext := filepath.Ext(fullfilename)
    typ := mime.TypeByExtension(ext)

    // mime.TypeByExtension returns as text/plain; | charset=utf-8 the static .js (not always)
    if ext == ".js" && (typ == "text/plain" || typ == "text/plain; charset=utf-8") {

        if ext == ".js" {
            typ = "application/javascript"
        }
    }
    return typ
}

Hope that helped you and other users, don't hesitate to post again if you have more questions!

AttributeError: 'datetime' module has no attribute 'strptime'

If I had to guess, you did this:

import datetime

at the top of your code. This means that you have to do this:

datetime.datetime.strptime(date, "%Y-%m-%d")

to access the strptime method. Or, you could change the import statement to this:

from datetime import datetime

and access it as you are.

The people who made the datetime module also named their class datetime:

#module  class    method
datetime.datetime.strptime(date, "%Y-%m-%d")

Is it possible to use std::string in a constexpr?

No, and your compiler already gave you a comprehensive explanation.

But you could do this:

constexpr char constString[] = "constString";

At runtime, this can be used to construct a std::string when needed.

Single line if statement with 2 actions

userType = (user.Type == 0) ? "Admin" : (user.type == 1) ? "User" : "Admin";

should do the trick.

laravel 5 : Class 'input' not found

In Laravel 5.2 Input:: is replaced with Request::

use

Request::

Add to the top of Controller or any other Class

use Illuminate\Http\Request;

Binary Search Tree - Java Implementation

Here is a sample implementation:

import java.util.*;

public class MyBSTree<K,V> implements MyTree<K,V>{
    private BSTNode<K,V> _root;
    private int _size;
    private Comparator<K> _comparator;
    private int mod = 0;

    public MyBSTree(Comparator<K> comparator){
        _comparator = comparator;
    }

    public Node<K,V> root(){
        return _root;
    }

    public int size(){
        return _size;
    }

    public boolean containsKey(K key){
        if(_root == null){
            return false;
        }

        BSTNode<K,V> node = _root;

        while (node != null){
            int comparison = compare(key, node.key());

            if(comparison == 0){
                return true;
            }else if(comparison <= 0){
                node = node._left;
            }else {
                node = node._right;
            }
        }

        return false;
    }

    private int compare(K k1, K k2){
        if(_comparator != null){
            return _comparator.compare(k1,k2);
        }
        else {
            Comparable<K> comparable = (Comparable<K>)k1;
            return comparable.compareTo(k2);
        }
    }


    public V get(K key){
        Node<K,V> node = node(key);

        return node != null ? node.value() : null;
    }

    private BSTNode<K,V> node(K key){
        if(_root != null){
            BSTNode<K,V> node = _root;

            while (node != null){
                int comparison = compare(key, node.key());

                if(comparison == 0){
                    return node;
                }else if(comparison <= 0){
                    node = node._left;
                }else {
                    node = node._right;
                }
            }
        }

        return null;
    }

    public void add(K key, V value){
        if(key == null){
            throw new IllegalArgumentException("key");
        }

        if(_root == null){
            _root = new BSTNode<K, V>(key, value);
        }

        BSTNode<K,V> prev = null, curr = _root;
        boolean lastChildLeft = false;
        while(curr != null){
            int comparison = compare(key, curr.key());
            prev = curr;

            if(comparison == 0){
                curr._value = value;
                return;
            }else if(comparison < 0){
                curr = curr._left;
                lastChildLeft = true;
            }
            else{
                curr = curr._right;
                lastChildLeft = false;
            }
        }

        mod++;
        if(lastChildLeft){
            prev._left = new BSTNode<K, V>(key, value);
        }else {
            prev._right = new BSTNode<K, V>(key, value);
        }
    }

    private void removeNode(BSTNode<K,V> curr){
        if(curr.left() == null && curr.right() == null){
            if(curr == _root){
                _root = null;
            }else{
                if(curr.isLeft()) curr._parent._left = null;
                else curr._parent._right = null;
            }
        }
        else if(curr._left == null && curr._right != null){
            curr._key = curr._right._key;
            curr._value = curr._right._value;
            curr._left = curr._right._left;
            curr._right = curr._right._right;
        }
        else if(curr._left != null && curr._right == null){
            curr._key = curr._left._key;
            curr._value = curr._left._value;
            curr._right = curr._left._right;
            curr._left = curr._left._left;
        }
        else { // both left & right exist
            BSTNode<K,V> x = curr._left;
            // find right-most node of left sub-tree
            while (x._right != null){ 
                x = x._right;
            }
            // move that to current
            curr._key = x._key;
            curr._value = x._value;
            // delete duplicate data
            removeNode(x);
        }
    }


    public V remove(K key){
        BSTNode<K,V> curr = _root;
        V val = null;
        while(curr != null){
            int comparison = compare(key, curr.key());
            if(comparison == 0){
                val = curr._value;
                removeNode(curr);
                mod++;
                break;
            }else if(comparison < 0){
                curr = curr._left;
            }
            else{
                curr = curr._right;
            }
        }

        return val;
    }

    public Iterator<MyTree.Node<K,V>> iterator(){
        return new MyIterator();
    }

    private class MyIterator implements Iterator<Node<K,V>>{
        int _startMod;
        Stack<BSTNode<K,V>> _stack;

        public MyIterator(){
            _startMod = MyBSTree.this.mod;
            _stack = new Stack<BSTNode<K, V>>();

            BSTNode<K,V> node = MyBSTree.this._root;
            while (node != null){
                _stack.push(node);
                node = node._left;
            }
        }

        public void remove(){
            throw new UnsupportedOperationException();
        }

        public boolean hasNext(){
            if(MyBSTree.this.mod != _startMod){
                throw new ConcurrentModificationException();
            }

            return !_stack.empty();
        }

        public Node<K,V> next(){
            if(MyBSTree.this.mod != _startMod){
                throw new ConcurrentModificationException();
            }

            if(!hasNext()){
                throw new NoSuchElementException();
            }

            BSTNode<K,V> node = _stack.pop();
            BSTNode<K,V> x = node._right;
            while (x != null){
                _stack.push(x);
                x = x._left;
            }

            return node;
        }
    }

    @Override
    public String toString(){
        if(_root == null) return "[]";

        return _root.toString();
    }

    private static class BSTNode<K,V> implements Node<K,V>{
        K _key;
        V _value;
        BSTNode<K,V> _left, _right, _parent;

        public BSTNode(K key, V value){
            if(key == null){
                throw new IllegalArgumentException("key");
            }

            _key = key;
            _value = value;
        }

        public K key(){
            return _key;
        }

        public V value(){
            return _value;
        }

        public Node<K,V> left(){
            return _left;
        }

        public Node<K,V> right(){
            return _right;
        }

        public Node<K,V> parent(){
            return _parent;
        }

        boolean isLeft(){
            if(_parent == null) return false;

            return _parent._left == this;
        }

        boolean isRight(){
            if(_parent == null) return false;

            return _parent._right == this;
        }

        @Override
        public boolean equals(Object o){
            if(o == null){
                return false;
            }

            try{
                BSTNode<K,V> node = (BSTNode<K,V>)o;
                return node._key.equals(_key) && ((_value == null && node._value == null) || (_value != null && _value.equals(node._value)));
            }catch (ClassCastException ex){
                return false;
            }
        }

        @Override
        public int hashCode(){
            int hashCode = _key.hashCode();

            if(_value != null){
                hashCode ^= _value.hashCode();
            }

            return hashCode;
        }

        @Override
        public String toString(){
            String leftStr = _left != null ? _left.toString() : "";
            String rightStr = _right != null ? _right.toString() : "";
            return "["+leftStr+" "+_key+" "+rightStr+"]";
        }
    }
}

Iterate over a Javascript associative array in sorted order

There's no concise way to directly manipulate the "keys" of a Javascript object. It's not really designed for that. Do you have the freedom to put your data in something better than a regular object (or an Array, as your sample code suggests)?

If so, and if your question could be rephrased as "What dictionary-like object should I use if I want to iterate over the keys in sorted order?" then you might develop an object like this:

var a = {
  keys : new Array(),
  hash : new Object(),
  set : function(key, value) {
    if (typeof(this.hash[key]) == "undefined") { this.keys.push(key); }
    this.hash[key] = value;
  },
  get : function(key) {
    return this.hash[key];
  },
  getSortedKeys : function() {
    this.keys.sort();
    return this.keys;
  }
};

// sample use
a.set('b',1);
a.set('z',1);
a.set('a',1);
var sortedKeys = a.getSortedKeys();
for (var i in sortedKeys) { print(sortedKeys[i]); }

If you have no control over the fact that the data is in a regular object, this utility would convert the regular object to your fully-functional dictionary:

a.importObject = function(object) {
  for (var i in object) { this.set(i, object); }
};

This was a object definition (instead of a reusable constructor function) for simplicity; edit at will.

Is there a limit to the length of a GET request?

Not in the RFC, no, but there are practical limits.

The HTTP protocol does not place any a priori limit on the length of a URI. Servers MUST be able to handle the URI of any resource they serve, and SHOULD be able to handle URIs of unbounded length if they provide GET-based forms that could generate such URIs. A server SHOULD return 414 (Request-URI Too Long) status if a URI is longer than the server can handle (see section 10.4.15).

Note: Servers should be cautious about depending on URI lengths above 255 bytes, because some older client or proxy implementations may not properly support these lengths.

Jquery button click() function is not working

You need to use the event delegation syntax of .on() here. Change:

$("#add").click(function() {

to

$("#buildyourform").on('click', '#add', function () {

jsFiddle example

How to change MySQL column definition?

Syntax to change column name in MySql:

alter table table_name change old_column_name new_column_name data_type(size);

Example:

alter table test change LowSal Low_Sal integer(4);

Text in Border CSS HTML

Yes, but it's not a div, it's a fieldset

_x000D_
_x000D_
fieldset {
    border: 1px solid #000;
}
_x000D_
<fieldset>
  <legend>AAA</legend>
</fieldset>
_x000D_
_x000D_
_x000D_

What characters are forbidden in Windows and Linux directory names?

Under Linux and other Unix-related systems, there are only two characters that cannot appear in the name of a file or directory, and those are NUL '\0' and slash '/'. The slash, of course, can appear in a path name, separating directory components.

Rumour1 has it that Steven Bourne (of 'shell' fame) had a directory containing 254 files, one for every single letter (character code) that can appear in a file name (excluding /, '\0'; the name . was the current directory, of course). It was used to test the Bourne shell and routinely wrought havoc on unwary programs such as backup programs.

Other people have covered the Windows rules.

Note that MacOS X has a case-insensitive file system.


1 It was Kernighan & Pike in The Practice of Programming who said as much in Chapter 6, Testing, §6.5 Stress Tests:

When Steve Bourne was writing his Unix shell (which came to be known as the Bourne shell), he made a directory of 254 files with one-character names, one for each byte value except '\0' and slash, the two characters that cannot appear in Unix file names. He used that directory for all manner of tests of pattern-matching and tokenization. (The test directory was of course created by a program.) For years afterwards, that directory was the bane of file-tree-walking programs; it tested them to destruction.

Note that the directory must have contained entries . and .., so it was arguably 253 files (and 2 directories), or 255 name entries, rather than 254 files. This doesn't affect the effectiveness of the anecdote, or the careful testing it describes.

How can I get the source code of a Python function?

If you are using IPython, then you need to type "foo??"

In [19]: foo??
Signature: foo(arg1, arg2)
Source:
def foo(arg1,arg2):
    #do something with args
    a = arg1 + arg2
    return a

File:      ~/Desktop/<ipython-input-18-3174e3126506>
Type:      function

Min/Max-value validators in asp.net mvc

Here is how I would write a validator for MaxValue

public class MaxValueAttribute : ValidationAttribute
    {
        private readonly int _maxValue;

        public MaxValueAttribute(int maxValue)
        {
            _maxValue = maxValue;
        }

        public override bool IsValid(object value)
        {
            return (int) value <= _maxValue;
        }
    }

The MinValue Attribute should be fairly the same

Getting the difference between two repositories

Once you have both branches in one repository you can do a git diff. And getting them in one repository is as easy as

git fetch /the/other/repo/.git refs/heads/*:refs/remotes/other/*

What are the applications of binary trees?

To squabble about the performance of binary-trees is meaningless - they are not a data structure, but a family of data structures, all with different performance characteristics. While it is true that unbalanced binary trees perform much worse than self-balancing binary trees for searching, there are many binary trees (such as binary tries) for which "balancing" has no meaning.

Applications of binary trees

  • Binary Search Tree - Used in many search applications where data is constantly entering/leaving, such as the map and set objects in many languages' libraries.
  • Binary Space Partition - Used in almost every 3D video game to determine what objects need to be rendered.
  • Binary Tries - Used in almost every high-bandwidth router for storing router-tables.
  • Hash Trees - used in p2p programs and specialized image-signatures in which a hash needs to be verified, but the whole file is not available.
  • Heaps - Used in implementing efficient priority-queues, which in turn are used for scheduling processes in many operating systems, Quality-of-Service in routers, and A* (path-finding algorithm used in AI applications, including robotics and video games). Also used in heap-sort.
  • Huffman Coding Tree (Chip Uni) - used in compression algorithms, such as those used by the .jpeg and .mp3 file-formats.
  • GGM Trees - Used in cryptographic applications to generate a tree of pseudo-random numbers.
  • Syntax Tree - Constructed by compilers and (implicitly) calculators to parse expressions.
  • Treap - Randomized data structure used in wireless networking and memory allocation.
  • T-tree - Though most databases use some form of B-tree to store data on the drive, databases which keep all (most) their data in memory often use T-trees to do so.

The reason that binary trees are used more often than n-ary trees for searching is that n-ary trees are more complex, but usually provide no real speed advantage.

In a (balanced) binary tree with m nodes, moving from one level to the next requires one comparison, and there are log_2(m) levels, for a total of log_2(m) comparisons.

In contrast, an n-ary tree will require log_2(n) comparisons (using a binary search) to move to the next level. Since there are log_n(m) total levels, the search will require log_2(n)*log_n(m) = log_2(m) comparisons total. So, though n-ary trees are more complex, they provide no advantage in terms of total comparisons necessary.

(However, n-ary trees are still useful in niche-situations. The examples that come immediately to mind are quad-trees and other space-partitioning trees, where divisioning space using only two nodes per level would make the logic unnecessarily complex; and B-trees used in many databases, where the limiting factor is not how many comparisons are done at each level but how many nodes can be loaded from the hard-drive at once)

Using "If cell contains #N/A" as a formula condition.

"N/A" is not a string it is an error, try this:

=if(ISNA(A1),C1)

you have to place this fomula in cell B1 so it will get the value of your formula

How do you compare structs for equality in C?

You can't use memcmp to compare structs for equality due to potential random padding characters between field in structs.

  // bad
  memcmp(&struct1, &struct2, sizeof(struct1));

The above would fail for a struct like this:

typedef struct Foo {
  char a;
  /* padding */
  double d;
  /* padding */
  char e;
  /* padding */
  int f;
} Foo ;

You have to use member-wise comparison to be safe.

How to send a compressed archive that contains executables so that Google's attachment filter won't reject it

Try this:

tar -czf my.tar.gz dir/

But are you sure you are not compressing some .exe file or something? Maybe the problem is not with te compression, but with the files you are compressing?

Find out how much memory is being used by an object in Python

Another approach is to use pickle. See this answer to a duplicate of this question.

How to set an HTTP proxy in Python 2.7?

It looks like get-pip.py has been updated to use the environment variables http_proxy and https_proxy.

Windows:

set http_proxy=http://proxy.myproxy.com
set https_proxy=https://proxy.myproxy.com
python get-pip.py

Linux/OS X:

export http_proxy=http://proxy.myproxy.com
export https_proxy=https://proxy.myproxy.com
sudo -E python get-pip.py

However if this still doesn't work for you, you can always install pip through a proxy using setuptools' easy_install by setting the same environment variables.

Windows:

set http_proxy=http://proxy.myproxy.com
set https_proxy=https://proxy.myproxy.com
easy_install pip

Linux/OS X:

export http_proxy=http://proxy.myproxy.com
export https_proxy=https://proxy.myproxy.com
sudo -E easy_install pip

Then once it's installed, use:

pip install --proxy="user:password@server:port" packagename

From the pip man page:

--proxy
Have pip use a proxy server to access sites. This can be specified using "user:[email protected]:port" notation. If the password is left out, pip will ask for it.

Python Matplotlib figure title overlaps axes label when using twiny

ax.set_title('My Title\n', fontsize="15", color="red")
plt.imshow(myfile, origin="upper")

If you put '\n' right after your title string, the plot is drawn just below the title. That might be a fast solution too.

The pipe ' ' could not be found angular2 custom pipe

I have created a module for pipes in the same directory where my pipes are present

import { NgModule } from '@angular/core';
///import pipe...
import { Base64ToImage, TruncateString} from './'  

   @NgModule({
        imports: [],
        declarations: [Base64ToImage, TruncateString],
        exports: [Base64ToImage, TruncateString]
    })

    export class SharedPipeModule { }   

Now import that module in app.module:

import {SharedPipeModule} from './pipe/shared.pipe.module'
 @NgModule({
     imports: [
    ...
    , PipeModule.forRoot()
    ....
  ],

Now it can be used by importing the same in the nested module

Cookies vs. sessions

SESSIONS ENDS WHEN USER CLOSES THEIR BROWSER,

COOKIES END DEPENDING ON THE LIFETIME YOU SET FOR IT. SO THEY CAN LAST FOR YEARS

This is the major difference in your choice,

If you want the id to be remembered for long time, then you need to use cookies; otherwise if you just want the website to recognize the user for this visit only then sessions is the way to go.

Sessions are stored in a file your php server will generate. To remember which file is for which user, php will also set a cookie on the user's browser that holds this session file id so in their next visit php will read this file and reload the session.

Now php by default clears sessions every interval, and also naming convention of session make it auto expire. Also, browsers will not keep the cookie that holds the session id once the browser is closed or the history is cleared.

It's important to note that nowadays browsers also support another kind of storage engines such as LocalStorage, SessionStorage, and other webdb engines that javascript code can use to save data to your computer to remember you. If you open the javascript console inside Facebook, for example, and type "localStorage" you will see all the variables Facebook uses to remember you without cookies.

HTML5 Video Autoplay not working correctly

Try autoplay="autoplay" instead of the "true" value. That's the documented way to enable autoplay. That sounds weirdly redundant, I know.

Meaning of Choreographer messages in Logcat

This usually happens when debugging using the emulator, which is known to be slow anyway.

How to loop backwards in python?

range() and xrange() take a third parameter that specifies a step. So you can do the following.

range(10, 0, -1)

Which gives

[10, 9, 8, 7, 6, 5, 4, 3, 2, 1] 

But for iteration, you should really be using xrange instead. So,

xrange(10, 0, -1)

Note for Python 3 users: There are no separate range and xrange functions in Python 3, there is just range, which follows the design of Python 2's xrange.

Can I pass parameters by reference in Java?

From James Gosling in "The Java Programming Language":

"...There is exactly one parameter passing mode in Java - pass by value - and that keeps things simple. .."

Checking if a variable is not nil and not zero in ruby

You can convert your empty row to integer value and check zero?.

"".to_i.zero? => true
nil.to_i.zero? => true

Why Python 3.6.1 throws AttributeError: module 'enum' has no attribute 'IntFlag'?

If anyone coming here because of getting this error while running a google app engine Python 3.7 standard environment project in PyCharm then all you need to do is

  • Make sure the configuration to run is for Flask, not Google App Engine configuration.
  • Then disable Google App Engine support under Preferences >> Languages & Framework >> Google App Engine

The reason being as per this link

The overall goal is that your app should be fully portable and run in any standard Python environment. You write a standard Python app, not an App Engine Python app. As part of this shift, you are no longer required to use proprietary App Engine APIs and services for your app's core functionality. At this time, App Engine APIs are not available in the Python 3.7 runtime.

I guess when we create a python 3.7 project in PyCharm as a Google app engine project it still tries to do the same way it does for a python2.7 app

Java Multithreading concept and join() method

My Comments:

When I see the output, the output is mixed with One, Two, Three which are the thread names and they run simultaneously. I am not sure when you say thread is not running by main method.

Not sure if I understood your question or not. But I m putting my answer what I could understand, hope it can help you.

1) Then you created the object, it called the constructor, in construct it has start method which started the thread and executed the contents written inside run() method.

So as you created 3 objects (3 threads - one, two, three), all 3 threads started executing simultaneously.

2) Join and Synchronization They are 2 different things, Synchronization is when there are multiple threads sharing a common resource and one thread should use that resource at a time. E.g. Threads such as DepositThread, WithdrawThread etc. do share a common object as BankObject. So while DepositThread is running, the WithdrawThread will wait if they are synchronized. wait(), notify(), notifyAll() are used for inter-thread communication. Plz google to know more.

about Join(), it is when multiple threads are running, but you join. e.g. if there are two thread t1 and t2 and in multi-thread env they run, the output would be: t1-0 t2-0 t1-1 t2-1 t1-2 t2-2

and we use t1.join(), it would be: t1-0 t1-1 t1-2 t2-0 t2-1 t2-2

This is used in realtime when sometimes you don't mix up the thread in certain conditions and one depends another to be completed (not in shared resource), so you can call the join() method.

libpng warning: iCCP: known incorrect sRGB profile

Thanks to the fantastic answer from Glenn, I used ImageMagik's "mogrify *.png" functionality. However, I had images buried in sub-folders, so I used this simple Python script to apply this to all images in all sub-folders and thought it might help others:

import os
import subprocess

def system_call(args, cwd="."):
    print("Running '{}' in '{}'".format(str(args), cwd))
    subprocess.call(args, cwd=cwd)
    pass

def fix_image_files(root=os.curdir):
    for path, dirs, files in os.walk(os.path.abspath(root)):
        # sys.stdout.write('.')
        for dir in dirs:
            system_call("mogrify *.png", "{}".format(os.path.join(path, dir)))


fix_image_files(os.curdir)

JavaFX How to set scene background image

You can change style directly for scene using .root class:

.root {
    -fx-background-image: url("https://www.google.com/images/srpr/logo3w.png");
}

Add this to CSS and load it as "Uluk Biy" described in his answer.

Comparing two dataframes and getting the differences

# THIS WORK FOR ME

# Get all diferent values
df3 = pd.merge(df1, df2, how='outer', indicator='Exist')
df3 = df3.loc[df3['Exist'] != 'both']


# If you like to filter by a common ID
df3  = pd.merge(df1, df2, on="Fruit", how='outer', indicator='Exist')
df3  = df3.loc[df3['Exist'] != 'both']

Superscript in CSS only?

I am not sure if this is related but I have solved my problem with &sup2; HTML entities as I wasn't able to add any other html tags inside a <label> tag. So the idea was using ASCII codes instead of css or HTML tags.

How can a file be copied?

Function Copies
metadata
Copies
permissions
Uses file object Destination
may be directory
shutil.copy No Yes No Yes
shutil.copyfile No No No No
shutil.copy2 Yes Yes No Yes
shutil.copyfileobj No No Yes No

Adding Python Path on Windows 7

You can set the path from the current cmd window using the PATH = command. That will only add it for the current cmd instance. if you want to add it permanently, you should add it to system variables. (Computer > Advanced System Settings > Environment Variables)

You would goto your cmd instance, and put in PATH=C:/Python27/;%PATH%.

ASP.NET MVC Ajax Error handling

If the server sends some status code different than 200, the error callback is executed:

$.ajax({
    url: '/foo',
    success: function(result) {
        alert('yeap');
    },
    error: function(XMLHttpRequest, textStatus, errorThrown) {
        alert('oops, something bad happened');
    }
});

and to register a global error handler you could use the $.ajaxSetup() method:

$.ajaxSetup({
    error: function(XMLHttpRequest, textStatus, errorThrown) {
        alert('oops, something bad happened');
    }
});

Another way is to use JSON. So you could write a custom action filter on the server which catches exception and transforms them into JSON response:

public class MyErrorHandlerAttribute : FilterAttribute, IExceptionFilter
{
    public void OnException(ExceptionContext filterContext)
    {
        filterContext.ExceptionHandled = true;
        filterContext.Result = new JsonResult
        {
            Data = new { success = false, error = filterContext.Exception.ToString() },
            JsonRequestBehavior = JsonRequestBehavior.AllowGet
        };
    }
}

and then decorate your controller action with this attribute:

[MyErrorHandler]
public ActionResult Foo(string id)
{
    if (string.IsNullOrEmpty(id))
    {
        throw new Exception("oh no");
    }
    return Json(new { success = true });
}

and finally invoke it:

$.getJSON('/home/foo', { id: null }, function (result) {
    if (!result.success) {
        alert(result.error);
    } else {
        // handle the success
    }
});

Delete certain lines in a txt file via a batch file

If you have perl installed, then perl -i -n -e"print unless m{(ERROR|REFERENCE)}" should do the trick.

Date Difference in php on days?

I would recommend to use date->diff function, as in example below:

   $dStart = new DateTime('2012-07-26');
   $dEnd  = new DateTime('2012-08-26');
   $dDiff = $dStart->diff($dEnd);
   echo $dDiff->format('%r%a'); // use for point out relation: smaller/greater

see http://www.php.net/manual/en/datetime.diff.php

Execute method on startup in Spring

Posted another solution that implements WebApplicationInitializer and is called much before any spring bean is instantiated, in case someone has that use case

Initialize default Locale and Timezone with Spring configuration

Batch Renaming of Files in a Directory

directoryName = "Photographs"
filePath = os.path.abspath(directoryName)
filePathWithSlash = filePath + "\\"

for counter, filename in enumerate(os.listdir(directoryName)):

    filenameWithPath = os.path.join(filePathWithSlash, filename)

    os.rename(filenameWithPath, filenameWithPath.replace(filename,"DSC_" + \
          str(counter).zfill(4) + ".jpg" ))

# e.g. filename = "photo1.jpg", directory = "c:\users\Photographs"        
# The string.replace call swaps in the new filename into 
# the current filename within the filenameWitPath string. Which    
# is then used by os.rename to rename the file in place, using the  
# current (unmodified) filenameWithPath.

# os.listdir delivers the filename(s) from the directory
# however in attempting to "rename" the file using os 
# a specific location of the file to be renamed is required.

# this code is from Windows 

Nodejs send file in response

Here's an example program that will send myfile.mp3 by streaming it from disk (that is, it doesn't read the whole file into memory before sending the file). The server listens on port 2000.

[Update] As mentioned by @Aftershock in the comments, util.pump is gone and was replaced with a method on the Stream prototype called pipe; the code below reflects this.

var http = require('http'),
    fileSystem = require('fs'),
    path = require('path');

http.createServer(function(request, response) {
    var filePath = path.join(__dirname, 'myfile.mp3');
    var stat = fileSystem.statSync(filePath);

    response.writeHead(200, {
        'Content-Type': 'audio/mpeg',
        'Content-Length': stat.size
    });

    var readStream = fileSystem.createReadStream(filePath);
    // We replaced all the event handlers with a simple call to readStream.pipe()
    readStream.pipe(response);
})
.listen(2000);

Taken from http://elegantcode.com/2011/04/06/taking-baby-steps-with-node-js-pumping-data-between-streams/

How to hide Soft Keyboard when activity starts

Ed_Cat_Search = (EditText) findViewById(R.id.editText_Searc_Categories);

Ed_Cat_Search.setInputType(InputType.TYPE_NULL);

Ed_Cat_Search.setOnTouchListener(new View.OnTouchListener() {
    public boolean onTouch(View v, MotionEvent event) {
        Ed_Cat_Search.setInputType(InputType.TYPE_CLASS_TEXT);
        Ed_Cat_Search.onTouchEvent(event); // call native handler
        return true; // consume touch even
    }
});

this one worked for me

How to read strings from a Scanner in a Java console application?

Scanner scanner = new Scanner(System.in);
int employeeId, supervisorId;
String name;
System.out.println("Enter employee ID:");
employeeId = scanner.nextInt();
scanner.nextLine(); //This is needed to pick up the new line
System.out.println("Enter employee name:");
name = scanner.nextLine();
System.out.println("Enter supervisor ID:");
supervisorId = scanner.nextInt();

Calling nextInt() was a problem as it didn't pick up the new line (when you hit enter). So, calling scanner.nextLine() after that does the work.

How to center text vertically with a large font-awesome icon?

Well, this question was asked years ago. I think technology has changed quite a bit and browser compatibility is much better. You could use vertical-align but I would consider that some what less scaleable and less reusable. I would recommend a flexbox approach.

Here is the same example the original poster used but with flexbox. It styles a single element. If a button size changes for whatever reason, it will continue to be vertically and horizontally centered.

.button {
    border: 1px solid #ccc;
    height: 40px;
    margin: 60px;
    padding: 4px;
    display: flex;
    justify-content: space-around;
    align-items: center;
}

Example: JsFiddle

Apache Name Virtual Host with SSL

The VirtualHost would look like this:

NameVirtualHost IP_Address:443

<VirtualHost IP_Address:443>
    SSLEngine on
    SSLCertificateFile /etc/pki/tls/certs/ca.crt    # Where "ca" is the name of the Certificate
    SSLCertificateKeyFile /etc/pki/tls/private/ca.key
    ServerAdmin webmaster@domain_name.com
    DocumentRoot /var/www/html
    ServerName www.domain_name.com
    ErrorLog logs/www.domain_name.com-error_log
    CustomLog logs/www.domain_name.com-access_log common
</VirtualHost>

calculating the difference in months between two dates

Way late to the game but I imagine this may be helpful to someone. The majority of people tend to measure month to month by date excluding the fact that months come in different variations. Using that frame of thought I created a one liner which compares the dates for us. Using the the following process.

  1. Any # of years over 1 when comparing year will be multiplied by 12, there is no case where this can be equal to less than 1 full year.
  2. If the end year is greater we need to evaluate if the current day is greater or equal to the previous day 2A. If the end day is greater or equal we take the current month and then add 12 months subtract the month of the start month 2B. If the end day is less than the start day we perform the the same as above except we add 1 to the start month before subtracting
  3. If the end year is not greater we perform the same as 2A/2B, but without adding the 12 months because we do not need to evaluate around the year.

        DateTime date = new DateTime(2003, 11, 25);
        DateTime today = new DateTime(2004, 12, 26);
        var time = (today.Year - date.Year > 1 ? (today.Year - date.Year - 1) * 12 : 0) +  (today.Year > date.Year ? (today.Day >= date.Day ? today.Month + 12 - date.Month : today.Month + 12 - (date.Month + 1)) : (today.Day >= date.Day ? today.Month - date.Month : today.Month - (date.Month + 1)));
    

JPA - Returning an auto generated id after persist()

@Entity
public class ABC implements Serializable {
     @Id
     @GeneratedValue(strategy=GenerationType.IDENTITY)
     private int id;   
}

check that @GeneratedValue notation is there in your entity class.This tells JPA about your entity property auto-generated behavior

How to reduce the image file size using PIL

See the thumbnail function of PIL's Image Module. You can use it to save smaller versions of files as various filetypes and if you're wanting to preserve as much quality as you can, consider using the ANTIALIAS filter when you do.

Other than that, I'm not sure if there's a way to specify a maximum desired size. You could, of course, write a function that might try saving multiple versions of the file at varying qualities until a certain size is met, discarding the rest and giving you the image you wanted.

How to change the icon of .bat file programmatically?

i recommand to use BAT to EXE converter for your desires

jQuery .slideRight effect

Another solution is by using .animate() and appropriate CSS.

e.g.

   $('#mydiv').animate({ marginLeft: "100%"} , 4000);

JS Fiddle

Easy interview question got harder: given numbers 1..100, find the missing number(s) given exactly k are missing

As @j_random_hacker pointed out, this is quite similar to Finding duplicates in O(n) time and O(1) space, and an adaptation of my answer there works here too.

Assuming that the "bag" is represented by a 1-based array A[] of size N - k, we can solve Qk in O(N) time and O(k) additional space.

First, we extend our array A[] by k elements, so that it is now of size N. This is the O(k) additional space. We then run the following pseudo-code algorithm:

for i := n - k + 1 to n
    A[i] := A[1]
end for

for i := 1 to n - k
    while A[A[i]] != A[i] 
        swap(A[i], A[A[i]])
    end while
end for

for i := 1 to n
    if A[i] != i then 
        print i
    end if
end for

The first loop initialises the k extra entries to the same as the first entry in the array (this is just a convenient value that we know is already present in the array - after this step, any entries that were missing in the initial array of size N-k are still missing in the extended array).

The second loop permutes the extended array so that if element x is present at least once, then one of those entries will be at position A[x].

Note that although it has a nested loop, it still runs in O(N) time - a swap only occurs if there is an i such that A[i] != i, and each swap sets at least one element such that A[i] == i, where that wasn't true before. This means that the total number of swaps (and thus the total number of executions of the while loop body) is at most N-1.

The third loop prints those indexes of the array i that are not occupied by the value i - this means that i must have been missing.

Dynamic height for DIV

calculate the height of each link no do this

document.getElementById("products").style.height= height_of_each_link* no_of_link

How to initialize a private static const map in C++?

If the map is to contain only entries that are known at compile time and the keys to the map are integers, then you do not need to use a map at all.

char get_value(int key)
{
    switch (key)
    {
        case 1:
            return 'a';
        case 2:
            return 'b';
        case 3:
            return 'c';
        default:
            // Do whatever is appropriate when the key is not valid
    }
}

Assigning the return value of new by reference is deprecated

Perhaps the constructor of MDB2 has some code that uses a $variable =& new ClassName();

Maintaining href "open in new tab" with an onClick handler in React

React + TypeScript inline util method:

const navigateToExternalUrl = (url: string, shouldOpenNewTab: boolean = true) =>
shouldOpenNewTab ? window.open(url, "_blank") : window.location.href = url;

Instagram API: How to get all user media?

In June 2016 Instagram made most of the functionality of their API available only to applications that have passed a review process. They still however provide JSON data through the web interface, and you can add the parameter __a=1 to a URL to only include the JSON data.

max=
while :;do
  c=$(curl -s "https://www.instagram.com/username/?__a=1&max_id=$max")
  jq -r '.user.media.nodes[]?|.display_src'<<<"$c"
  max=$(jq -r .user.media.page_info.end_cursor<<<"$c")
  jq -e .user.media.page_info.has_next_page<<<"$c">/dev/null||break
done

Edit: As mentioned in the comment by alnorth29, the max_id parameter is now ignored. Instagram also changed the format of the response, and you need to perform additional requests to get the full-size URLs of images in the new-style posts with multiple images per post. You can now do something like this to list the full-size URLs of images on the first page of results:

c=$(curl -s "https://www.instagram.com/username/?__a=1")
jq -r '.graphql.user.edge_owner_to_timeline_media.edges[]?|.node|select(.__typename!="GraphSidecar").display_url'<<<"$c"
jq -r '.graphql.user.edge_owner_to_timeline_media.edges[]?|.node|select(.__typename=="GraphSidecar")|.shortcode'<<<"$c"|while read l;do
  curl -s "https://www.instagram.com/p/$l?__a=1"|jq -r '.graphql.shortcode_media|.edge_sidecar_to_children.edges[]?.node|.display_url'
done

To make a list of the shortcodes of each post made by the user whose profile is opened in the frontmost tab in Safari, I use a script like this:

sjs(){ osascript -e'{on run{a}','tell app"safari"to do javascript a in document 1',end} -- "$1";}

while :;do
  sjs 'o="";a=document.querySelectorAll(".v1Nh3 a");for(i=0;e=a[i];i++){o+=e.href+"\n"};o'>>/tmp/a
  sjs 'window.scrollBy(0,window.innerHeight)'
  sleep 1
done

Can a table row expand and close?

Yes, a table row can slide up and down, but it's ugly, since it changes the shape of the table and makes everything jump. Instead, put and element in each td... something that makes sense like a p or h2 etc.

For how to implement a table slide toggle...

It's probably simplest to put the click handler on the entire table, .stopPropagation() and check what was clicked.

If a td in a row with a colspan is clicked, close the p in it. If it's not a td in a row with a colspan, then close then toggle the following row's p.

It is essentially to wrap all your written content in an element inside the tds, since you never want to slideUp a td or tr or table shape will change!

Something like:

$(function() {

      // Initially hide toggleable content
    $("td[colspan=3]").find("p").hide();

      // Click handler on entire table
    $("table").click(function(event) {

          // No bubbling up
        event.stopPropagation();

        var $target = $(event.target);

          // Open and close the appropriate thing
        if ( $target.closest("td").attr("colspan") > 1 ) {
            $target.slideUp();
        } else {
            $target.closest("tr").next().find("p").slideToggle();
        }                    
    });
});?

Try it out with this jsFiddle example.

... and try out this jsFiddle showing implementation of a + - - toggle.

The HTML just has to have alternating rows of several tds and then a row with a td of a colspan greater than 1. You can obviously adjust the specifics quite easily.

The HTML would look something like:

<table>
    <tr><td><p>Name</p></td><td><p>Age</p></td><td><p>Info</p></td></tr>
    <tr><td colspan="3"><p>Blah blah blah blah blah blah blah.</p>
    </td></tr>

    <tr><td><p>Name</p></td><td><p>Age</p></td><td><p>Info</p></td></tr>
    <tr><td colspan="3"><p>Blah blah blah blah blah blah blah.</p>
    </td></tr>

    <tr><td><p>Name</p></td><td><p>Age</p></td><td><p>Info</p></td></tr>
    <tr><td colspan="3"><p>Blah blah blah blah blah blah blah.</p>
    </td></tr>    
</table>?

html table cell width for different rows

You can't have cells of arbitrarily different widths, this is generally a standard behaviour of tables from any space, e.g. Excel, otherwise it's no longer a table but just a list of text.

You can however have cells span multiple columns, such as:

<table>
    <tr>
        <td>25</td>
        <td>50</td>
        <td>25</td>
    </tr>
    <tr>
        <td colspan="2">75</td>
        <td>20</td>
    </tr>
</table>

As an aside, you should avoid using style attributes like border and bgcolor and prefer CSS for those.

Immutable vs Mutable types

A mutable object has to have at least a method able to mutate the object. For example, the list object has the append method, which will actually mutate the object:

>>> a = [1,2,3]
>>> a.append('hello') # `a` has mutated but is still the same object
>>> a
[1, 2, 3, 'hello']

but the class float has no method to mutate a float object. You can do:

>>> b = 5.0 
>>> b = b + 0.1
>>> b
5.1

but the = operand is not a method. It just make a bind between the variable and whatever is to the right of it, nothing else. It never changes or creates objects. It is a declaration of what the variable will point to, since now on.

When you do b = b + 0.1 the = operand binds the variable to a new float, wich is created with te result of 5 + 0.1.

When you assign a variable to an existent object, mutable or not, the = operand binds the variable to that object. And nothing more happens

In either case, the = just make the bind. It doesn't change or create objects.

When you do a = 1.0, the = operand is not wich create the float, but the 1.0 part of the line. Actually when you write 1.0 it is a shorthand for float(1.0) a constructor call returning a float object. (That is the reason why if you type 1.0 and press enter you get the "echo" 1.0 printed below; that is the return value of the constructor function you called)

Now, if b is a float and you assign a = b, both variables are pointing to the same object, but actually the variables can't comunicate betweem themselves, because the object is inmutable, and if you do b += 1, now b point to a new object, and a is still pointing to the oldone and cannot know what b is pointing to.

but if c is, let's say, a list, and you assign a = c, now a and c can "comunicate", because list is mutable, and if you do c.append('msg'), then just checking a you get the message.

(By the way, every object has an unique id number asociated to, wich you can get with id(x). So you can check if an object is the same or not checking if its unique id has changed.)

Bash if statement with multiple conditions throws an error

Use -a (for and) and -o (for or) operations.

tldp.org/LDP/Bash-Beginners-Guide/html/sect_07_01.html

Update

Actually you could still use && and || with the -eq operation. So your script would be like this:

my_error_flag=1
my_error_flag_o=1
if [ $my_error_flag -eq 1 ] ||  [ $my_error_flag_o -eq 2 ] || ([ $my_error_flag -eq 1 ] && [ $my_error_flag_o -eq 2 ]); then
      echo "$my_error_flag"
else
    echo "no flag"
fi

Although in your case you can discard the last two expressions and just stick with one or operation like this:

my_error_flag=1
my_error_flag_o=1
if [ $my_error_flag -eq 1 ] ||  [ $my_error_flag_o -eq 2 ]; then
      echo "$my_error_flag"
else
    echo "no flag"
fi

Representing Directory & File Structure in Markdown Syntax

As already recommended, you can use tree. But for using it together with restructured text some additional parameters were required.

The standard tree output will not be printed if your're using pandoc to produce pdf.

tree --dirsfirst --charset=ascii /path/to/directory will produce a nice ASCII tree that can be integrated into your document like this:

.. code::
.
|-- ContentStore
|   |-- de-DE
|   |   |-- art.mshc
|   |   |-- artnoloc.mshc
|   |   |-- clientserver.mshc
|   |   |-- noarm.mshc
|   |   |-- resources.mshc
|   |   `-- windowsclient.mshc
|   `-- en-US
|       |-- art.mshc
|       |-- artnoloc.mshc
|       |-- clientserver.mshc
|       |-- noarm.mshc
|       |-- resources.mshc
|       `-- windowsclient.mshc
`-- IndexStore
    |-- de-DE
    |   |-- art.mshi
    |   |-- artnoloc.mshi
    |   |-- clientserver.mshi
    |   |-- noarm.mshi
    |   |-- resources.mshi
    |   `-- windowsclient.mshi
    `-- en-US
        |-- art.mshi
        |-- artnoloc.mshi
        |-- clientserver.mshi
        |-- noarm.mshi
        |-- resources.mshi
        `-- windowsclient.mshi

Inserting created_at data with Laravel

In your User model, add the following line in the User class:

public $timestamps = true;

Now, whenever you save or update a user, Laravel will automatically update the created_at and updated_at fields.


Update:
If you want to set the created at manually you should use the date format Y-m-d H:i:s. The problem is that the format you have used is not the same as Laravel uses for the created_at field.

Update: Nov 2018 Laravel 5.6 "message": "Access level to App\\Note::$timestamps must be public", Make sure you have the proper access level as well. Laravel 5.6 is public.

How to create a generic array?

checked :

public Constructor(Class<E> c, int length) {

    elements = (E[]) Array.newInstance(c, length);
}

or unchecked :

public Constructor(int s) {
    elements = new Object[s];
}

CustomErrors mode="Off"

I had the same issue but found resolve in a different way.

-

What I did was, I opened Advanced Settings for the Application Pool in IIS Manager.

There I set Enable 32-Bit Applications to True.

Custom Date Format for Bootstrap-DatePicker

I solve it editing the file bootstrap-datapicker.js.

Look for the text bellow in the file and edit the variable "Format:"

var defaults = $.fn.datepicker.defaults = {
    assumeNearbyYear: false,
    autoclose: false,
    beforeShowDay: $.noop,
    beforeShowMonth: $.noop,
    beforeShowYear: $.noop,
    beforeShowDecade: $.noop,
    beforeShowCentury: $.noop,
    calendarWeeks: false,
    clearBtn: false,
    toggleActive: false,
    daysOfWeekDisabled: [],
    daysOfWeekHighlighted: [],
    datesDisabled: [],
    endDate: Infinity,
    forceParse: true,
    format: 'dd/mm/yyyy',
    keyboardNavigation: true,
    language: 'en',
    minViewMode: 0,
    maxViewMode: 4,
    multidate: false,
    multidateSeparator: ',',
    orientation: "auto",
    rtl: false,
    startDate: -Infinity,
    startView: 0,
    todayBtn: false,
    todayHighlight: false,
    weekStart: 0,
    disableTouchKeyboard: false,
    enableOnReadonly: true,
    showOnFocus: true,
    zIndexOffset: 10,
    container: 'body',
    immediateUpdates: false,
    title: '',
    templates: {
        leftArrow: '&laquo;',
        rightArrow: '&raquo;'
    }
};

Set the location in iPhone Simulator

As of the writing of this, the location option for IOS simulator has been moved to Features -> Location -> Custom Location

How to insert special characters into a database?

You are most likely escaping the SQL string, similar to:

SELECT * FROM `table` WHERE `column` = 'Here's a syntax error!'

You need to escape quotes, like follows:

SELECT * FROM `table` WHERE `column` = 'Here\'s a syntax error!'

mysql_real_escape_string() handles this for you.

How to copy a directory structure but only include certain files (using windows batch files)

I am fine with regular expressions, lazy and averse to installs, so I created a batch file that creates the directory and copies with vanilla DOS commands. Seems laborious but quicker for me than working out robocopy.

  1. Create your list of source files with complete paths, including drive letter if nec, in a text file.
  2. Switch on regular expressions in your text editor.
  3. Add double quotes round each line in case of spaces - search string (.*) replace string "\1", and click replace all
  4. Create two lines per file - one to create the directory, one to copy the file (qqq will be replaced with destination path) - search string (.*) replace string md qqq\1\nxcopy \1 qqq\1\n and click replace all
  5. Remove the filename from the destination paths – search \\([^\\^"]+)"\n replace \\"\n
  6. Replace in the destination path (in this example A:\src and B:\dest). Turn OFF regular expressions, search qqq"A:\src\ replace B:\dest\ and click replace all.

md will create nested directories. copy would probably behave identically to xcopy in this example. You might want to add /Y to xcopy to suppress overwrite confirms. You end up with a batch file like so:

md "B:\dest\a\b\c\"
xcopy "C:\src\a\b\c\e.xyz" "B:\dest\a\b\c\e.xyz"

repeated for every file in your original list. Tested on Win7.

How to extract request http headers from a request using NodeJS connect

To see a list of HTTP request headers, you can use :

console.log(JSON.stringify(req.headers));

to return a list in JSON format.

{
"host":"localhost:8081",
"connection":"keep-alive",
"cache-control":"max-age=0",
"accept":"text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8",
"upgrade-insecure-requests":"1",
"user-agent":"Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/44.0.2403.107 Safari/537.36",
"accept-encoding":"gzip, deflate, sdch",
"accept-language":"en-US,en;q=0.8,et;q=0.6"
}

Pass a PHP variable value through an HTML form

EDIT: After your comments, I understand that you want to pass variable through your form.

You can do this using hidden field:

<input type='hidden' name='var' value='<?php echo "$var";?>'/> 

In PHP action File:

<?php 
   if(isset($_POST['var'])) $var=$_POST['var'];
?>

Or using sessions: In your first page:

 $_SESSION['var']=$var;

start_session(); should be placed at the beginning of your php page.

In PHP action File:

if(isset($_SESSION['var'])) $var=$_SESSION['var'];

First Answer:

You can also use $GLOBALS :

if (isset($_POST['save_exit']))
{

   echo $GLOBALS['var']; 

}

Check this documentation for more informations.

Sql Server 'Saving changes is not permitted' error ? Prevent saving changes that require table re-creation

1) Open tool which is on top.
2) Choose options from Picklist.
3) Now Comes the popup and you can now select designers option from the list of menus on the left side.
4) Now prevent saving changes need to be unchecked that needed table re-creation. Now Click OK.

How do I upgrade to Python 3.6 with conda?

Only solution that works was create a new conda env with the name you want (you will, unfortunately, delete the old one to keep the name). Then create a new env with a new python version and re-run your install.sh script with the conda/pip installs (or the yaml file or whatever you use to keep your requirements):

conda remove --name original_name --all
conda create --name original_name python=3.8
sh install.sh  # or whatever you usually do to install dependencies

doing conda install python=3.8 doesn't work for me. Also, why do you want 3.6? Move forward with the word ;)


Note bellow doesn't work:

If you want to update the conda version of your previous env what you can also do is the following (more complicated than it should be because you cannot rename envs in conda):

  1. create a temporary new location for your current env:
conda create --name temporary_env_name --clone original_env_name
  1. delete the original env (so that the new env can have that name):
conda deactivate
conda remove --name original_env_name --all # or its alias: `conda env remove --name original_env_name`
  1. then create the new empty env with the python version you want and clone the original env:
conda create --name original_env_name python=3.8 --clone temporary_env_name

How to create a template function within a class? (C++)

See here: Templates, template methods,Member Templates, Member Function Templates

class   Vector
{
  int     array[3];

  template <class TVECTOR2> 
  void  eqAdd(TVECTOR2 v2);
};

template <class TVECTOR2>
void    Vector::eqAdd(TVECTOR2 a2)
{
  for (int i(0); i < 3; ++i) array[i] += a2[i];
}

Failed to load ApplicationContext for JUnit test of Spring controller

If you are using Maven, add the below config in your pom.xml:

<build>
    <testResources>
                <testResource>
                    <directory>src/main/webapp</directory>
                </testResource>
    </testResources>
</build>

With this config, you will be able to access xml files in WEB-INF folder. From Maven POM Reference: The testResources element block contains testResource elements. Their definitions are similar to resource elements, but are naturally used during test phases.

Cannot declare instance members in a static class in C#

I know this post is old but...

I was able to do this, my problem was that I forgot to make my property static.

public static class MyStaticClass
{
    private static NonStaticObject _myObject = new NonStaticObject();

    //property
    public static NonStaticObject MyObject
    {
        get { return _myObject; }
        set { _myObject = value; }
    }
}

How to solve npm install throwing fsevents warning on non-MAC OS?

I'm using, Angular CLI: 8.1.2 Node: 12.14.1 OS: win32 x64

Strangely, this helped me

npm cache clean --force
npm uninstall @angular/cli
npm install @angular/[email protected]

XPath - Selecting elements that equal a value

The XPath spec. defines the string value of an element as the concatenation (in document order) of all of its text-node descendents.

This explains the "strange results".

"Better" results can be obtained using the expressions below:

//*[text() = 'qwerty']

The above selects every element in the document that has at least one text-node child with value 'qwerty'.

//*[text() = 'qwerty' and not(text()[2])]

The above selects every element in the document that has only one text-node child and its value is: 'qwerty'.

Socket File "/var/pgsql_socket/.s.PGSQL.5432" Missing In Mountain Lion (OS X Server)

It took me a while but I was able to get this working finally after going through the suggestions offered and additional web searches being done. I used the information in the following YouTube video created by Mactasia:

http://www.youtube.com/watch?v=y1c7WFMMkZ4

When I did this I saw the file with .lock as the extension. However I still got the error when I tried to start the Rails Server when I resumed working on my Rails application using PostgreSQL. This time I got a permission denied error. This is when I remembered that not only did I have to change listen_addresses in the plist but I also had to change unit_socket_permissions to 0777. I also logged in as root to change the permissions on the var/pgsql_socket folder where I could access it at the user level. Postgres is working fine now. I am in the process of reloading my data from my SQL backup.

What I did not understand was that when I had wiki turned on PostgreSQL was supposedly working when I did a sudo serveradmin fullstatus postgres but I still got the error. Oh well.

Using ls to list directories and their total sizes

The command you want is 'du -sk' du = "disk usage"

The -k flag gives you output in kilobytes, rather than the du default of disk sectors (512-byte blocks).

The -s flag will only list things in the top level directory (i.e., the current directory, by default, or the directory specified on the command line). It's odd that du has the opposite behavior of ls in this regard. By default du will recursively give you the disk usage of each sub-directory. In contrast, ls will only give list files in the specified directory. (ls -R gives you recursive behavior.)