Programs & Examples On #Image segmentation

Segmentation is a basic operation in image processing: its purpose is to group similar pixels into coherent regions = segments.

Difference between two dates in MySQL

This code calculate difference between two dates in yyyy MM dd format.

declare @StartDate datetime 
declare @EndDate datetime

declare @years int
declare @months int 
declare @days int

--NOTE: date of birth must be smaller than As on date, 
--else it could produce wrong results
set @StartDate = '2013-12-30' --birthdate
set @EndDate  = Getdate()            --current datetime

--calculate years
select @years = datediff(year,@StartDate,@EndDate)

--calculate months if it's value is negative then it 
--indicates after __ months; __ years will be complete
--To resolve this, we have taken a flag @MonthOverflow...
declare @monthOverflow int
select @monthOverflow = case when datediff(month,@StartDate,@EndDate) - 
  ( datediff(year,@StartDate,@EndDate) * 12) <0 then -1 else 1 end
--decrease year by 1 if months are Overflowed
select @Years = case when @monthOverflow < 0 then @years-1 else @years end
select @months =  datediff(month,@StartDate,@EndDate) - (@years * 12) 

--as we do for month overflow criteria for days and hours 
--& minutes logic will followed same way
declare @LastdayOfMonth int
select @LastdayOfMonth =  datepart(d,DATEADD
    (s,-1,DATEADD(mm, DATEDIFF(m,0,@EndDate)+1,0)))

select @days = case when @monthOverflow<0 and 
    DAY(@StartDate)> DAY(@EndDate) 
then @LastdayOfMonth + 
  (datepart(d,@EndDate) - datepart(d,@StartDate) ) - 1  
      else datepart(d,@EndDate) - datepart(d,@StartDate) end 


select
 @Months=case when @days < 0 or DAY(@StartDate)> DAY(@EndDate) then @Months-1 else @Months end

Declare @lastdayAsOnDate int;
set @lastdayAsOnDate = datepart(d,DATEADD(s,-1,DATEADD(mm, DATEDIFF(m,0,@EndDate),0)));
Declare @lastdayBirthdate int;
set @lastdayBirthdate =  datepart(d,DATEADD(s,-1,DATEADD(mm, DATEDIFF(m,0,@StartDate)+1,0)));

if (@Days < 0) 
(
    select @Days = case when( @lastdayBirthdate > @lastdayAsOnDate) then
        @lastdayBirthdate + @Days
    else
        @lastdayAsOnDate + @Days
    end
)
print  convert(varchar,@years)   + ' year(s),   '  +
       convert(varchar,@months)  + ' month(s),   ' +
       convert(varchar,@days)    + ' day(s)   '   

Visualizing decision tree in scikit-learn

Alternatively, you could try using pydot for producing the png file from dot:

...
tree.export_graphviz(dtreg, out_file='tree.dot') #produces dot file

import pydot
dotfile = StringIO()
tree.export_graphviz(dtreg, out_file=dotfile)
pydot.graph_from_dot_data(dotfile.getvalue()).write_png("dtree2.png")
...

Return row of Data Frame based on value in a column - R

Based on the syntax provided

 Select * Where Amount = min(Amount)

You could do using:

 library(sqldf)

Using @Kara Woo's example df

  sqldf("select * from df where Amount in (select min(Amount) from df)")
  #Name Amount
 #1    B    120
 #2    E    120

Could not load type from assembly error

I had this issue after factoring a class name:
Could not load type 'Namspace.OldClassName' from assembly 'Assembly name...'.

Stopping IIS and deleting the contents in Temporary ASP.NET Files fixed it up for me.

Depeding on your project (32/64bit, .net version, etc) the correct Temporary ASP.NET Files differs:

  • 64 Bit
    %systemroot%\Microsoft.NET\Framework64\{.netversion}\Temporary ASP.NET Files\
  • 32 Bit
    %systemroot%\Microsoft.NET\Framework\{.netversion}\Temporary ASP.NET Files\
  • On my dev machine it was (Because its IIS Express maybe?)
    %temp%\Temporary ASP.NET Files

Create a custom event in Java

You probably want to look into the observer pattern.

Here's some sample code to get yourself started:

import java.util.*;

// An interface to be implemented by everyone interested in "Hello" events
interface HelloListener {
    void someoneSaidHello();
}

// Someone who says "Hello"
class Initiater {
    private List<HelloListener> listeners = new ArrayList<HelloListener>();

    public void addListener(HelloListener toAdd) {
        listeners.add(toAdd);
    }

    public void sayHello() {
        System.out.println("Hello!!");

        // Notify everybody that may be interested.
        for (HelloListener hl : listeners)
            hl.someoneSaidHello();
    }
}

// Someone interested in "Hello" events
class Responder implements HelloListener {
    @Override
    public void someoneSaidHello() {
        System.out.println("Hello there...");
    }
}

class Test {
    public static void main(String[] args) {
        Initiater initiater = new Initiater();
        Responder responder = new Responder();

        initiater.addListener(responder);

        initiater.sayHello();  // Prints "Hello!!!" and "Hello there..."
    }
}

Related article: Java: Creating a custom event

Centering the pagination in bootstrap

Bootstrap has added a new class from 3.0.

<div class="text-center">
    <ul class="pagination">
        <li><a href="?p=0" data-original-title="" title="">1</a></li> 
        <li><a href="?p=1" data-original-title="" title="">2</a></li> 
    </ul>
</div>

Bootstrap 4 has new class

<div class="text-xs-center">
    <ul class="pagination">
        <li><a href="?p=0" data-original-title="" title="">1</a></li> 
        <li><a href="?p=1" data-original-title="" title="">2</a></li> 
    </ul>
</div>

For 2.3.2

<div class="pagination text-center">
    <ul>
        <li><a href="?p=0" data-original-title="" title="">1</a></li> 
        <li><a href="?p=1" data-original-title="" title="">2</a></li> 
    </ul>
</div>

Give this way:

.pagination {text-align: center;}

It works because ul is using inline-block;

Fiddle: http://jsfiddle.net/praveenscience/5L8fu/


Or if you would like to use Bootstrap's class:

<div class="pagination pagination-centered">
    <ul>
        <li><a href="?p=0" data-original-title="" title="">1</a></li> 
        <li><a href="?p=1" data-original-title="" title="">2</a></li> 
    </ul>
</div>

Fiddle: http://jsfiddle.net/praveenscience/5L8fu/1/

How to enter a multi-line command

I assume you're talking about on the command-line - if it's in a script, then a new-line acts as a command delimiter.

On the command line, use a semi-colon ';'

How to find which views are using a certain table in SQL Server (2008)?

If you need to find database objects (e.g. tables, columns, triggers) by name - have a look at the FREE Red-Gate tool called SQL Search which does this - it searches your entire database for any kind of string(s).

enter image description here

enter image description here

It's a great must-have tool for any DBA or database developer - did I already mention it's absolutely FREE to use for any kind of use??

Resource leak: 'in' is never closed

You need call in.close(), in a finally block to ensure it occurs.

From the Eclipse documentation, here is why it flags this particular problem (emphasis mine):

Classes implementing the interface java.io.Closeable (since JDK 1.5) and java.lang.AutoCloseable (since JDK 1.7) are considered to represent external resources, which should be closed using method close(), when they are no longer needed.

The Eclipse Java compiler is able to analyze whether code using such types adheres to this policy.

...

The compiler will flag [violations] with "Resource leak: 'stream' is never closed".

Full explanation here.

Difference between break and continue statement

To prevent anything from execution if a condition is met one should use the continue and to get out of the loop if a condition is met one should use the break.

For example in the below mentioned code.

 for(int i=0;i<5;i++){

        if(i==3){

           continue;

        }
       System.out.println(i);
     }

The above code will print the result : 0 1 2 4

NOw consider this code

 for(int i=0;i<5;i++){


            if(i==3){

                break;

            }
            System.out.println(i);
         }

This code will print 0 1 2

That is the basic difference in the continue and break.

Using sendmail from bash script for multiple recipients

to use sendmail from the shell script

subject="mail subject"
body="Hello World"
from="[email protected]"
to="[email protected],[email protected]"
echo -e "Subject:${subject}\n${body}" | sendmail -f "${from}" -t "${to}"

413 Request Entity Too Large - File Upload Issue

Please enter domain nginx file :

nano /etc/nginx/sites-available/domain.set

Add to file this code

client_max_body_size 24000M;

If you get error use this command

nginx -t

Angularjs on page load call function

you can also use the below code.

function activateController(){
     console.log('HELLO WORLD');
}

$scope.$on('$viewContentLoaded', function ($evt, data) {
    activateController();
});

Regarding Java switch statements - using return and omitting breaks in each case

Yes this is good. Tutorials are not always consize and neat. Not only that, creating local variables is waste of space and inefficient

Unable to Build using MAVEN with ERROR - Failed to execute goal org.apache.maven.plugins:maven-compiler-plugin:3.1:compile

I was getting similar errors and eventually found just that cleaning the build folder resolved my issue.

mvn clean install

Putting GridView data in a DataTable

Copying Grid to datatable

        if (GridView.Rows.Count != 0)
        {
            //Forloop for header
            for (int i = 0; i < GridView.HeaderRow.Cells.Count; i++)
            {
                dt.Columns.Add(GridView.HeaderRow.Cells[i].Text);
            }
            //foreach for datarow
            foreach (GridViewRow row in GridView.Rows)
            {
                DataRow dr = dt.NewRow();
                for (int j = 0; j < row.Cells.Count; j++)
                {
                    dr[GridView.HeaderRow.Cells[j].Text] = row.Cells[j].Text;
                }
                dt.Rows.Add(dr);
            }
            //Loop for footer
            if (GridView.FooterRow.Cells.Count != 0)
            {
                DataRow dr = dt.NewRow();
                for (int i = 0; i < GridView.FooterRow.Cells.Count; i++)
                {
                    //You have to re-do the work if you did anything in databound for footer.  
                }
                dt.Rows.Add(dr);
            }
            dt.TableName = "tb";
        }

How to set cursor position in EditText?

setSelection(int index) method in Edittext should allow you to do this.

iOS - UIImageView - how to handle UIImage image orientation

UIImage extension in Swift. You don't need to do all that flipping at all, really. Objective-C original is here, but I've added the bit that respects the alpha of the original image (crudely, but it works to differentiate opaque images from transparent images).

// from https://github.com/mbcharbonneau/UIImage-Categories/blob/master/UIImage%2BAlpha.m
// Returns true if the image has an alpha layer
    private func hasAlpha() -> Bool {
        guard let cg = self.cgImage else { return false }
        let alpha = cg.alphaInfo
        let retVal = (alpha == .first || alpha == .last || alpha == .premultipliedFirst || alpha == .premultipliedLast)
        return retVal
    }

    func normalizedImage() -> UIImage? {
        if self.imageOrientation == .up {
            return self
        }
        UIGraphicsBeginImageContextWithOptions(self.size, !self.hasAlpha(), self.scale)
        var rect = CGRect.zero
        rect.size = self.size
        self.draw(in: rect)
        let retVal = UIGraphicsGetImageFromCurrentImageContext()
        UIGraphicsEndImageContext()
        return retVal
    }

JPanel Padding in Java

I will suppose your JPanel contains JTextField, for the sake of the demo.

Those components provides JTextComponent#setMargin() method which seems to be what you're looking for.

If you're looking for an empty border of any size around your text, well, use EmptyBorder

Highlight label if checkbox is checked

I like Andrew's suggestion, and in fact the CSS rule only needs to be:

:checked + label {
   font-weight: bold;
}

I like to rely on implicit association of the label and the input element, so I'd do something like this:

<label>
   <input type="checkbox"/>
   <span>Bah</span>
</label>

with CSS:

:checked + span {
    font-weight: bold;
}

Example: http://jsfiddle.net/wrumsby/vyP7c/

Image.open() cannot identify image file - Python?

Just a note for people having the same problem as me. I've been using OpenCV/cv2 to export numpy arrays into Tiffs but I had problems with opening these Tiffs with PIL Open Image and had the same error as in the title. The problem turned out to be that PIL Open Image could not open Tiffs which was created by exporting numpy float64 arrays. When I changed it to float32, PIL could open the Tiff again.

How to configure the web.config to allow requests of any length

Something else to check: if your site is using MVC, this can happen if you added [Authorize] to your login controller class. It can't access the login method because it's not authorized so it redirects to the login method --> boom.

How to multiply all integers inside list

using numpy :

    In [1]: import numpy as np

    In [2]: nums = np.array([1,2,3])*2

    In [3]: nums.tolist()
    Out[4]: [2, 4, 6]

Regular expression to match DNS hostname or IP Address?

It's worth noting that there are libraries for most languages that do this for you, often built into the standard library. And those libraries are likely to get updated a lot more often than code that you copied off a Stack Overflow answer four years ago and forgot about. And of course they'll also generally parse the address into some usable form, rather than just giving you a match with a bunch of groups.

For example, detecting and parsing IPv4 in (POSIX) C:

#include <arpa/inet.h>
#include <stdio.h>

int main(int argc, char *argv[]) {
  for (int i=1; i!=argc; ++i) {
    struct in_addr addr = {0};
    printf("%s: ", argv[i]);
    if (inet_pton(AF_INET, argv[i], &addr) != 1)
      printf("invalid\n");
    else
      printf("%u\n", addr.s_addr);
  }
  return 0;
}

Obviously, such functions won't work if you're trying to, e.g., find all valid addresses in a chat message—but even there, it may be easier to use a simple but overzealous regex to find potential matches, and then use the library to parse them.

For example, in Python:

>>> import ipaddress
>>> import re
>>> msg = "My address is 192.168.0.42; 192.168.0.420 is not an address"
>>> for maybeip in re.findall(r'\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}', msg):
...     try:
...         print(ipaddress.ip_address(maybeip))
...     except ValueError:
...         pass

httpd: Could not reliably determine the server's fully qualified domain name, using 127.0.0.1 for ServerName

If you don't have httpd.conf in folder /etc/apache2, you should have apache2.conf - simply add:

ServerName localhost

Then restart the apache2 service.

Excel: Can I create a Conditional Formula based on the Color of a Cell?

You can use this function (I found it here: http://excelribbon.tips.net/T010780_Colors_in_an_IF_Function.html):

Function GetFillColor(Rng As Range) As Long
    GetFillColor = Rng.Interior.ColorIndex
End Function

Here is an explanation, how to create user-defined functions: http://www.wikihow.com/Create-a-User-Defined-Function-in-Microsoft-Excel

In your worksheet, you can use the following: =GetFillColor(B5)

Is there a php echo/print equivalent in javascript

$('element').html('<h1>TEXT TO INSERT</h1>');

or

$('element').text('TEXT TO INSERT');

Doctrine query builder using inner join with conditions

I'm going to answer my own question.

  1. innerJoin should use the keyword "WITH" instead of "ON" (Doctrine's documentation [13.2.6. Helper methods] is inaccurate; [13.2.5. The Expr class] is correct)
  2. no need to link foreign keys in join condition as they're already specified in the entity mapping.

Therefore, the following works for me

$qb->select('c')
    ->innerJoin('c.phones', 'p', 'WITH', 'p.phone = :phone')
    ->where('c.username = :username');

or

$qb->select('c')
    ->innerJoin('c.phones', 'p', Join::WITH, $qb->expr()->eq('p.phone', ':phone'))
    ->where('c.username = :username');

How can I parse a local JSON file from assets folder into a ListView?

Source code How to fetch Local Json from Assets folder

https://drive.google.com/open?id=1NG1amTVWPNViim_caBr8eeB4zczTDK2p

    {
        "responseCode": "200",
        "responseMessage": "Recode Fetch Successfully!",
        "responseTime": "10:22",
        "employeesList": [
            {
                "empId": "1",
                "empName": "Keshav",
                "empFatherName": "Mr Ramesh Chand Gera",
                "empSalary": "9654267338",
                "empDesignation": "Sr. Java Developer",
                "leaveBalance": "3",
                "pfBalance": "60,000",
                "pfAccountNo.": "12345678"
            },
            {
                "empId": "2",
                "empName": "Ram",
                "empFatherName": "Mr Dasrath ji",
                "empSalary": "9999999999",
                "empDesignation": "Sr. Java Developer",
                "leaveBalance": "3",
                "pfBalance": "60,000",
                "pfAccountNo.": "12345678"
            },
            {
                "empId": "3",
                "empName": "Manisha",
                "empFatherName": "Mr Ramesh Chand Gera",
                "empSalary": "8826420999",
                "empDesignation": "BusinessMan",
                "leaveBalance": "3",
                "pfBalance": "60,000",
                "pfAccountNo.": "12345678"
            },
            {
                "empId": "4",
                "empName": "Happy",
                "empFatherName": "Mr Ramesh Chand Gera",
                "empSalary": "9582401701",
                "empDesignation": "Two Wheeler",
                "leaveBalance": "3",
                "pfBalance": "60,000",
                "pfAccountNo.": "12345678"
            },
            {
                "empId": "5",
                "empName": "Ritu",
                "empFatherName": "Mr Keshav Gera",
                "empSalary": "8888888888",
                "empDesignation": "Sararat Vibhag",
                "leaveBalance": "3",
                "pfBalance": "60,000",
                "pfAccountNo.": "12345678"
            }
        ]
    }


 @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_employee);


        emp_recycler_view = (RecyclerView) findViewById(R.id.emp_recycler_view);

        emp_recycler_view.setLayoutManager(new LinearLayoutManager(EmployeeActivity.this, 
        LinearLayoutManager.VERTICAL, false));
        emp_recycler_view.setItemAnimator(new DefaultItemAnimator());

        employeeAdapter = new EmployeeAdapter(EmployeeActivity.this , employeeModelArrayList);

        emp_recycler_view.setAdapter(employeeAdapter);

        getJsonFileFromLocally();
    }



    public String loadJSONFromAsset() {
        String json = null;
        try {
            InputStream is = EmployeeActivity.this.getAssets().open("employees.json");       //TODO Json File  name from assets folder
            int size = is.available();
            byte[] buffer = new byte[size];
            is.read(buffer);
            is.close();
            json = new String(buffer, "UTF-8");
        } catch (IOException ex) {
            ex.printStackTrace();
            return null;
        }
        return json;
    }

    private void getJsonFileFromLocally() {
        try {

            JSONObject jsonObject = new JSONObject(loadJSONFromAsset());
            String responseCode = jsonObject.getString("responseCode");
            String responseMessage = jsonObject.getString("responseMessage");
            String responseTime = jsonObject.getString("responseTime");

            Log.e("keshav", "responseCode -->" + responseCode);
            Log.e("keshav", "responseMessage -->" + responseMessage);
            Log.e("keshav", "responseTime -->" + responseTime);


            if(responseCode.equals("200")){

            }else{
                Toast.makeText(this, "No Receord Found ", Toast.LENGTH_SHORT).show();
            }

            JSONArray jsonArray = jsonObject.getJSONArray("employeesList");                  //TODO pass array object name
            Log.e("keshav", "m_jArry -->" + jsonArray.length());


            for (int i = 0; i < jsonArray.length(); i++)
            {
                EmployeeModel employeeModel = new EmployeeModel();

                JSONObject jsonObjectEmployee = jsonArray.getJSONObject(i);


                String empId = jsonObjectEmployee.getString("empId");
                String empName = jsonObjectEmployee.getString("empName");
                String empDesignation = jsonObjectEmployee.getString("empDesignation");
                String empSalary = jsonObjectEmployee.getString("empSalary");
                String empFatherName = jsonObjectEmployee.getString("empFatherName");

                employeeModel.setEmpId(""+empId);
                employeeModel.setEmpName(""+empName);
                employeeModel.setEmpDesignation(""+empDesignation);
                employeeModel.setEmpSalary(""+empSalary);
                employeeModel.setEmpFatherNamer(""+empFatherName);

                employeeModelArrayList.add(employeeModel);

            }       // for

            if(employeeModelArrayList!=null) {
                employeeAdapter.dataChanged(employeeModelArrayList);
            }
        } catch (JSONException e) {
            e.printStackTrace();
        }
    }

Attach Authorization header for all axios requests

export const authHandler = (config) => {
  const authRegex = /^\/apiregex/;

  if (!authRegex.test(config.url)) {
    return store.fetchToken().then((token) => {
      Object.assign(config.headers.common, { Authorization: `Bearer ${token}` });
      return Promise.resolve(config);
    });
  }
  return Promise.resolve(config);
};

axios.interceptors.request.use(authHandler);

Ran into some gotchas when trying to implement something similar and based on these answers this is what I came up with. The problems I was experiencing were:

  1. If using axios for the request to get a token in your store, you need to detect the path before adding the header. If you don't, it will try to add the header to that call as well and get into a circular path issue. The inverse of adding regex to detect the other calls would also work
  2. If the store is returning a promise, you need to return the call to the store to resolve the promise in the authHandler function. Async/Await functionality would make this easier/more obvious
  3. If the call for the auth token fails or is the call to get the token, you still want to resolve a promise with the config

Javascript Confirm popup Yes, No button instead of OK and Cancel

You can also use http://projectshadowlight.org/jquery-easy-confirm-dialog/ . It's very simple and easy to use. Just include jquery common library and one more file only:

<script src="http://ajax.googleapis.com/ajax/libs/jquery/1.3.2/jquery.min.js" type="text/javascript"></script>
<script src="http://ajax.googleapis.com/ajax/libs/jqueryui/1.7.2/jquery-ui.min.js"></script>
<link rel="stylesheet" href="http://ajax.googleapis.com/ajax/libs/jqueryui/1.7.1/themes/blitzer/jquery-ui.css" type="text/css" />
<script src="jquery.easy-confirm-dialog.js"></script>

Inserting values into tables Oracle SQL

INSERT
INTO    Employee 
        (emp_id, emp_name, emp_address, emp_state, emp_position, emp_manager)
SELECT  '001', 'John Doe', '1 River Walk, Green Street', state_id, position_id, manager_id
FROM    dual
JOIN    state s
ON      s.state_name = 'New York'
JOIN    positions p
ON      p.position_name = 'Sales Executive'
JOIN    manager m
ON      m.manager_name = 'Barry Green'

Note that but a single spelling mistake (or an extra space) will result in a non-match and nothing will be inserted.

Why do I need to explicitly push a new branch?

HEAD is short for current branch so git push -u origin HEAD works. Now to avoid this typing everytime I use alias:

git config --global alias.pp 'push -u origin HEAD'

After this, everytime I want to push branch created via git -b branch I can push it using:

git pp

Hope this saves time for someone!

How to use Javascript to read local text file and read line by line?

Using ES6 the javascript becomes a little cleaner

handleFiles(input) {

    const file = input.target.files[0];
    const reader = new FileReader();

    reader.onload = (event) => {
        const file = event.target.result;
        const allLines = file.split(/\r\n|\n/);
        // Reading line by line
        allLines.forEach((line) => {
            console.log(line);
        });
    };

    reader.onerror = (event) => {
        alert(event.target.error.name);
    };

    reader.readAsText(file);
}

How to debug Angular JavaScript Code

1. Chrome

For debugging AngularJS in Chrome you can use AngularJS Batarang. (From recent reviews on the plugin it seems like AngularJS Batarang is no longer being maintained. Tested in various versions of Chrome and it does not work.)

Here is the the link for a description and demo: Introduction of Angular JS Batarang

Download Chrome plugin from here: Chrome plugin for debugging AngularJS

You can also use ng-inspect for debugging angular.

2. Firefox

For Firefox with the help of Firebug you can debug the code.

Also use this Firefox Add-Ons: AngScope: Add-ons for Firefox (Not official extension by AngularJS Team)

3. Debugging AngularJS

Check the Link: Debugging AngularJS

Is it possible to style html5 audio tag?

some color tunings

audio {
    filter: sepia(20%) saturate(70%) grayscale(1) contrast(99%) invert(12%);
    width: 200px;
    height: 25px;
}

The executable gets signed with invalid entitlements in Xcode

In my case, the device wasn't added. So I had to add the device and generate a new provisioning profile.

Converting cv::Mat to IplImage*

According to OpenCV cheat-sheet this can be done as follows:

IplImage* oldC0 = cvCreateImage(cvSize(320,240),16,1);
Mat newC = cvarrToMat(oldC0);

The cv::cvarrToMat function takes care of the conversion issues.

Alert after page load

Another option to resolve issue described in OP which I encountered on recent bootcamp training is using window.setTimeout to wrap around the code which is bothersome. My understanding is that it delays the execution of the function for the specified time period (500ms in this case), allowing enough time for the page to load. So, for example:

<script type = "text/javascript">
            window.setTimeout(function(){
                alert("Hello World!");
            }, 500); 
</script>

How to reformat JSON in Notepad++?

You can use http://www.jsonlint.com/ to edit your json online if you don't have Notepad++.

Swift UIView background color opacity

You can set background color of view to the UIColor with alpha, and not affect view.alpha:

view.backgroundColor = UIColor(white: 1, alpha: 0.5)

or

view.backgroundColor = UIColor.red.withAlphaComponent(0.5)

WAMP server, localhost is not working

The best solution is:

  1. Right click on Computer -> Properties -> Device manager.
  2. View -> Show hidden devices.
  3. Choose Non-plug and plug drivers -> HTTP -> Disable.
  4. Restart your computer.

How do I parse JSON in Android?

Android has all the tools you need to parse json built-in. Example follows, no need for GSON or anything like that.

Get your JSON:

Assume you have a json string

String result = "{\"someKey\":\"someValue\"}";

Create a JSONObject:

JSONObject jObject = new JSONObject(result);

If your json string is an array, e.g.:

String result = "[{\"someKey\":\"someValue\"}]"

then you should use JSONArray as demonstrated below and not JSONObject

To get a specific string

String aJsonString = jObject.getString("STRINGNAME");

To get a specific boolean

boolean aJsonBoolean = jObject.getBoolean("BOOLEANNAME");

To get a specific integer

int aJsonInteger = jObject.getInt("INTEGERNAME");

To get a specific long

long aJsonLong = jObject.getLong("LONGNAME");

To get a specific double

double aJsonDouble = jObject.getDouble("DOUBLENAME");

To get a specific JSONArray:

JSONArray jArray = jObject.getJSONArray("ARRAYNAME");

To get the items from the array

for (int i=0; i < jArray.length(); i++)
{
    try {
        JSONObject oneObject = jArray.getJSONObject(i);
        // Pulling items from the array
        String oneObjectsItem = oneObject.getString("STRINGNAMEinTHEarray");
        String oneObjectsItem2 = oneObject.getString("anotherSTRINGNAMEINtheARRAY");
    } catch (JSONException e) {
        // Oops
    }
}

how to convert `content://media/external/images/media/Y` to `file:///storage/sdcard0/Pictures/X.jpg` in android?

Will something like this work for you? What this does is query the content resolver to find the file path data that is stored for that content entry

public static String getRealPathFromUri(Context context, Uri contentUri) {
    Cursor cursor = null;
    try {
        String[] proj = { MediaStore.Images.Media.DATA };
        cursor = context.getContentResolver().query(contentUri, proj, null, null, null);
        int column_index = cursor.getColumnIndexOrThrow(MediaStore.Images.Media.DATA);
        cursor.moveToFirst();
        return cursor.getString(column_index);
    } finally {
        if (cursor != null) {
            cursor.close();
        }
    }
}

This will end up giving you an absolute file path that you can construct a file uri from

Can I change the Android startActivity() transition animation?

Most of the answers are pretty correct, but some of them are deprecated such as when using R.anim.hold and some of them are just elaboratig the process.

So, you can use:

startActivity(intent);
overridePendingTransition(android.R.anim.fade_in, android.R.anim.fade_out);

Single huge .css file vs. multiple smaller specific .css files?

Historically, one of the main advantages x in having a single CSS file is the speed benefit when using HTTP1.1.

However, as of March 2018 over 80% of browsers now support HTTP2 which allows the browser to download multiple resources simultaneously as well as being able to push resources pre-emptively. Having a single CSS file for all pages means a larger than necessary file size. With proper design, I don't see any advantage in doing this other than its easier to code.

The ideal design for HTTP2 for best performance would be:

  • Have a core CSS file which contains common styles used across all pages.
  • Have page specific CSS in a separate file
  • Use HTTP2 push CSS to minimise wait time (a cookie can be used to prevent repeated pushes)
  • Optionally separate above the fold CSS and push this first and load the remaining CSS later (useful for low-bandwidth mobile devices)
  • You could also load remaining CSS for the site or specific pages after the page has loaded if you want to speed up future page loads.

Check if an HTML input element is empty or has no value entered by user

You want:

if (document.getElementById('customx').value === ""){
    //do something
}

The value property will give you a string value and you need to compare that against an empty string.

How to check the input is an integer or not in Java?

        String input = "";
        int inputInteger = 0;
        BufferedReader br    = new BufferedReader(new InputStreamReader (System.in));

        System.out.println("Enter the radious: ");
        try {
            input = br.readLine();
            inputInteger = Integer.parseInt(input);
        } catch (NumberFormatException e) {
            System.out.println("Please Enter An Integer");
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
        float area = (float) (3.14*inputInteger*inputInteger);
        System.out.println("Area = "+area);

How to link C++ program with Boost using CMake

Adapting @MOnsDaR answer for modern CMake syntax with imported targets, this would be:

find_package(Boost 1.40 COMPONENTS program_options REQUIRED)

add_executable(anyExecutable myMain.cpp)

target_link_libraries(anyExecutable Boost::program_options)

Note that it is not necessary to specify the include directories manually, since it is already taken care of through the imported target Boost::program_options.

Conveniently map between enum and int / String

A very clean usage example of reverse Enum

Step 1 Define an interface EnumConverter

public interface EnumConverter <E extends Enum<E> & EnumConverter<E>> {
    public String convert();
    E convert(String pKey);
}

Step 2

Create a class name ReverseEnumMap

import java.util.HashMap;
import java.util.Map;

public class ReverseEnumMap<V extends Enum<V> & EnumConverter<V>> {
    private Map<String, V> map = new HashMap<String, V>();

    public ReverseEnumMap(Class<V> valueType) {
        for (V v : valueType.getEnumConstants()) {
            map.put(v.convert(), v);
        }
    }

    public V get(String pKey) {
        return map.get(pKey);
    }
}

Step 3

Go to you Enum class and implement it with EnumConverter<ContentType> and of course override interface methods. You also need to initialize a static ReverseEnumMap.

public enum ContentType implements EnumConverter<ContentType> {
    VIDEO("Video"), GAME("Game"), TEST("Test"), IMAGE("Image");

    private static ReverseEnumMap<ContentType> map = new ReverseEnumMap<ContentType>(ContentType.class);

    private final String mName;

    ContentType(String pName) {
        this.mName = pName;
    }

    String value() {
        return this.mName;
    }

    @Override
    public String convert() {
        return this.mName;
    }

    @Override
    public ContentType convert(String pKey) {
        return map.get(pKey);
    }
}

Step 4

Now create a Communication class file and call it's new method to convert an Enum to String and String to Enum. I have just put main method for explanation purpose.

public class Communication<E extends Enum<E> & EnumConverter<E>> {
    private final E enumSample;

    public Communication(E enumSample) {
        this.enumSample = enumSample;
    }

    public String resolveEnumToStringValue(E e) {
        return e.convert();
    }

    public E resolveStringEnumConstant(String pName) {
        return enumSample.convert(pName);
    }

//Should not put main method here... just for explanation purpose. 
    public static void main(String... are) {
        Communication<ContentType> comm = new Communication<ContentType>(ContentType.GAME);
        comm.resolveEnumToStringValue(ContentType.GAME); //return Game
        comm.resolveStringEnumConstant("Game"); //return GAME (Enum)
    }
}

Click for for complete explanation

How could I create a list in c++?

Create list using C++ templates

i.e

template <class T> struct Node 
{
    T data;
    Node * next;
};
    
template <class T> class List 
{
    Node<T> *head,*tail;
        
    public: 
        void push(T const&);  // push element 
        void pop();           // pop element 
        bool empty()          // return true if empty. 
}; 

Then you can write the code like:

List<MyClass>;

The type T is not dynamic in run time.It is only for the compile time.

For complete example click here.

For C++ templates tutorial click here.

How to "git show" a merge commit with combined diff output even when every changed file agrees with one of the parents?

If you are sitting at the merge commit then this shows the diffs:

git diff HEAD~1..HEAD

If you're not at the merge commit then just replace HEAD with the merge commit. This method seems like the simplest and most intuitive.

Set default time in bootstrap-datetimepicker

Set a default input value as per this GitHub issue.

HTML

<input type="text" id="datetimepicker-input"></input>

jQuery

var d = new Date();

var month = d.getMonth()+1;
var day = d.getDate();

var output = d.getFullYear() + '/' +
(month<10 ? '0' : '') + month + '/' +
(day<10 ? '0' : '') + day;

$("#datetimepicker-input").val(output + " 00:01:00");

jsFiddle
JavaScript date source

EDIT - setLocalDate/setDate

var d = new Date();
var month = d.getMonth();
var day = d.getDate();
var year = d.getFullYear();

$('#startdatetime-from').datetimepicker({
    language: 'en',
    format: 'yyyy-MM-dd hh:mm'
});
$("#startdatetime-from").data('DateTimePicker').setLocalDate(new Date(year, month, day, 00, 01));

jsFiddle

How to programmatically set the layout_align_parent_right attribute of a Button in Relative Layout?

  1. you need to create and id for the buttons you need to refference: btn1.setId(1);
  2. you can use the params variable to add parameters to your layout, i think the method is addRule(), check out the android java docs for this LayoutParams object.

What is this weird colon-member (" : ") syntax in the constructor?

You are correct, this is indeed a way to initialize member variables. I'm not sure that there's much benefit to this, other than clearly expressing that it's an initialization. Having a "bar=num" inside the code could get moved around, deleted, or misinterpreted much more easily.

How to get the response of XMLHttpRequest?

I'd suggest looking into fetch. It is the ES5 equivalent and uses Promises. It is much more readable and easily customizable.

_x000D_
_x000D_
const url = "https://stackoverflow.com";
fetch(url)
    .then(
        response => response.text() // .json(), etc.
        // same as function(response) {return response.text();}
    ).then(
        html => console.log(html)
    );
_x000D_
_x000D_
_x000D_

In Node.js, you'll need to import fetch using:

const fetch = require("node-fetch");

If you want to use it synchronously (doesn't work in top scope):

const json = await fetch(url)
  .then(response => response.json())
  .catch((e) => {});

More Info:

Mozilla Documentation

Can I Use (95% Feb 2020)

Matt Walsh Tutorial

org.apache.tomcat.util.bcel.classfile.ClassFormatException: Invalid byte tag in constant pool: 15

The "offical answer" is that Tomcat 7 runs on Java 8, see http://tomcat.apache.org/whichversion.html ("Java version 6 and later").

However, if annotation scanning is enabled (metadata-complete="true" in web.xml) there are some issues due to BCEL (not able to process the new Java 8 byte codes). You will get exceptions like (at least with Tomcat 7.0.28):

SEVERE: Unable to process Jar entry [jdk/nashorn/internal/objects/NativeString.class] from Jar [jar:file:/usr/lib/jvm/jdk1.8.0_5/jre/lib/ext/nashorn.jar!/] for annotations
org.apache.tomcat.util.bcel.classfile.ClassFormatException: Invalid byte tag in constant pool: 15
    at org.apache.tomcat.util.bcel.classfile.Constant.readConstant(Constant.java:131)

If not using annotation scanning, everything works fine, starting release 7.0.53 (updated compiler with better Java 8 support).

(UPDATE 2014-10-17) If your are using annotation scanning and your own code is not Java 8 based, another solution is to add the following line in /etc/tomcat7/catalina.properties (text added after "ant-launcher.jar" so part of property tomcat.util.scan.DefaultJarScanner.jarsToSkip):

junit.jar,junit-*.jar,ant-launcher.jar,\
jfxrt.jar,nashorn.jar

Tested with Tomcat 7.0.28 and Oracle JDK 8_25 on Debian 7.6.

How to get user's high resolution profile picture on Twitter?

for me the "workaround" solution was to remove the "_normal" from the end of the string

Check it out below:

top -c command in linux to filter processes listed based on processname

Most of the answers fail here, when process list exceeds 20 processes. That is top -p option limit. For those with older top that does not support filtering with o options, here is a scriptable example to get full screen/console outuput (summary information is missing from this output).

__keyword="YOUR_FILTER" ; ( FILL=""; for i in  $( seq 1 $(stty size|cut -f1 -d" ")); do FILL=$'\n'$FILL; done ;  while :; do HSIZE=$(( $(stty size|cut -f1 -d" ")  - 1 ));  (top -bcn1 | grep "$__keyword"; echo "$FILL" )|head -n$HSIZE; sleep 1;done )

Some explanations

__keyword = your grep filter keyword
HSIZE=console height
FILL=new lines to fill the screen if list is shorter than console height
top -bcn1 = batch, full commandline, repeat once

Parameter "stratify" from method "train_test_split" (scikit Learn)

This stratify parameter makes a split so that the proportion of values in the sample produced will be the same as the proportion of values provided to parameter stratify.

For example, if variable y is a binary categorical variable with values 0 and 1 and there are 25% of zeros and 75% of ones, stratify=y will make sure that your random split has 25% of 0's and 75% of 1's.

Copy / Put text on the clipboard with FireFox, Safari and Chrome

For security reasons, Firefox doesn't allow you to place text on the clipboard. However, there is a work-around available using Flash.

function copyIntoClipboard(text) {

    var flashId = 'flashId-HKxmj5';

    /* Replace this with your clipboard.swf location */
    var clipboardSWF = 'http://appengine.bravo9.com/copy-into-clipboard/clipboard.swf';

    if(!document.getElementById(flashId)) {
        var div = document.createElement('div');
        div.id = flashId;
        document.body.appendChild(div);
    }
    document.getElementById(flashId).innerHTML = '';
    var content = '<embed src="' + 
        clipboardSWF +
        '" FlashVars="clipboard=' + encodeURIComponent(text) +
        '" width="0" height="0" type="application/x-shockwave-flash"></embed>';
    document.getElementById(flashId).innerHTML = content;
}

The only disadvantage is that this requires Flash to be enabled.

source is currently dead: http://bravo9.com/journal/copying-text-into-the-clipboard-with-javascript-in-firefox-safari-ie-opera-292559a2-cc6c-4ebf-9724-d23e8bc5ad8a/ (and so is it's Google cache)

How to add a changed file to an older (not last) commit in Git

Use git rebase. Specifically:

  1. Use git stash to store the changes you want to add.
  2. Use git rebase -i HEAD~10 (or however many commits back you want to see).
  3. Mark the commit in question (a0865...) for edit by changing the word pick at the start of the line into edit. Don't delete the other lines as that would delete the commits.[^vimnote]
  4. Save the rebase file, and git will drop back to the shell and wait for you to fix that commit.
  5. Pop the stash by using git stash pop
  6. Add your file with git add <file>.
  7. Amend the commit with git commit --amend --no-edit.
  8. Do a git rebase --continue which will rewrite the rest of your commits against the new one.
  9. Repeat from step 2 onwards if you have marked more than one commit for edit.

[^vimnote]: If you are using vim then you will have to hit the Insert key to edit, then Esc and type in :wq to save the file, quit the editor, and apply the changes. Alternatively, you can configure a user-friendly git commit editor with git config --global core.editor "nano".

How to create a List with a dynamic object type

It appears you might be a bit confused as to how the .Add method works. I will refer directly to your code in my explanation.

Basically in C#, the .Add method of a List of objects does not COPY new added objects into the list, it merely copies a reference to the object (it's address) into the List. So the reason every value in the list is pointing to the same value is because you've only created 1 new DyObj. So your list essentially looks like this.

DyObjectsList[0] = &DyObj; // pointing to DyObj
DyObjectsList[1] = &DyObj; // pointing to the same DyObj
DyObjectsList[2] = &DyObj; // pointing to the same DyObj

...

The easiest way to fix your code is to create a new DyObj for every .Add. Putting the new inside of the block with the .Add would accomplish this goal in this particular instance.

var DyObjectsList = new List<dynamic>; 
if (condition1) { 
    dynamic DyObj = new ExpandoObject(); 
    DyObj.Required = true; 
    DyObj.Message = "Message 1"; 
    DyObjectsList .Add(DyObj); 
} 
if (condition2) { 
    dynamic DyObj = new ExpandoObject(); 
    DyObj.Required = false; 
    DyObj.Message = "Message 2"; 
    DyObjectsList .Add(DyObj); 
} 

your resulting List essentially looks like this

DyObjectsList[0] = &DyObj0; // pointing to a DyObj
DyObjectsList[1] = &DyObj1; // pointing to a different DyObj
DyObjectsList[2] = &DyObj2; // pointing to another DyObj

Now in some other languages this approach wouldn't work, because as you leave the block, the objects declared in the scope of the block could go out of scope and be destroyed. Thus you would be left with a collection of pointers, pointing to garbage.

However in C#, if a reference to the new DyObjs exists when you leave the block (and they do exist in your List because of the .Add operation) then C# does not release the memory associated with that pointer. Therefore the Objects you created in that block persist and your List contains pointers to valid objects and your code works.

Determine if two rectangles overlap each other?

Lets say the two rectangles are rectangle A and rectangle B. Let their centers be A1 and B1 (coordinates of A1 and B1 can be easily found out), let the heights be Ha and Hb, width be Wa and Wb, let dx be the width(x) distance between A1 and B1 and dy be the height(y) distance between A1 and B1.

Now we can say we can say A and B overlap: when

if(!(dx > Wa+Wb)||!(dy > Ha+Hb)) returns true

nginx missing sites-available directory

If you'd prefer a more direct approach, one that does NOT mess with symlinking between /etc/nginx/sites-available and /etc/nginx/sites-enabled, do the following:

  1. Locate your nginx.conf file. Likely at /etc/nginx/nginx.conf
  2. Find the http block.
  3. Somewhere in the http block, write include /etc/nginx/conf.d/*.conf; This tells nginx to pull in any files in the conf.d directory that end in .conf. (I know: it's weird that a directory can have a . in it.)
  4. Create the conf.d directory if it doesn't already exist (per the path in step 3). Be sure to give it the right permissions/ownership. Likely root or www-data.
  5. Move or copy your separate config files (just like you have in /etc/nginx/sites-available) into the directory conf.d.
  6. Reload or restart nginx.
  7. Eat an ice cream cone.

Any .conf files that you put into the conf.d directory from here on out will become active as long as you reload/restart nginx after.

Note: You can use the conf.d and sites-enabled + sites-available method concurrently if you wish. I like to test on my dev box using conf.d. Feels faster than symlinking and unsymlinking.

forcing web-site to show in landscape mode only

While I myself would be waiting here for an answer, I wonder if it can be done via CSS:

@media only screen and (orientation:portrait){
#wrapper {width:1024px}
}

@media only screen and (orientation:landscape){
#wrapper {width:1024px}
}

Scala: write string to file in one statement

This is concise enough, I guess:

scala> import java.io._
import java.io._

scala> val w = new BufferedWriter(new FileWriter("output.txt"))
w: java.io.BufferedWriter = java.io.BufferedWriter@44ba4f

scala> w.write("Alice\r\nBob\r\nCharlie\r\n")

scala> w.close()

Spring @PropertySource using YAML

@PropertySource only supports properties files (it's a limitation from Spring, not Boot itself). Feel free to open a feature request ticket in JIRA.

Entity Framework Provider type could not be loaded?

I had the same issue with Instantiating DBContext object from a unit test project. I checked my unit test project packages and I figured that EntityFramework package was not installed, I installed that from Nuget and problem solved (I think it's EF bug).

happy coding

css 100% width div not taking up full width of parent

Remove the width:100%; declarations.

Block elements should take up the whole available width by default.

Dynamic SQL results into temp table in SQL Stored procedure

You can define a table dynamically just as you are inserting into it dynamically, but the problem is with the scope of temp tables. For example, this code:

DECLARE @sql varchar(max)
SET @sql = 'CREATE TABLE #T1 (Col1 varchar(20))'
EXEC(@sql)
INSERT INTO #T1 (Col1) VALUES ('This will not work.')
SELECT * FROM #T1

will return with the error "Invalid object name '#T1'." This is because the temp table #T1 is created at a "lower level" than the block of executing code. In order to fix, use a global temp table:

DECLARE @sql varchar(max)
SET @sql = 'CREATE TABLE ##T1 (Col1 varchar(20))'
EXEC(@sql)
INSERT INTO ##T1 (Col1) VALUES ('This will work.')
SELECT * FROM ##T1

Hope this helps, Jesse

How to split a string into a list?

str.split()

Return a list of the words in the string, using sep as the delimiter ... If sep is not specified or is None, a different splitting algorithm is applied: runs of consecutive whitespace are regarded as a single separator, and the result will contain no empty strings at the start or end if the string has leading or trailing whitespace.

>>> line="a sentence with a few words"
>>> line.split()
['a', 'sentence', 'with', 'a', 'few', 'words']
>>> 

How to get 'System.Web.Http, Version=5.2.3.0?

The packages you installed introduced dependencies to version 5.2.3.0 dll's as user Bracher showed above. Microsoft.AspNet.WebApi.Cors is an example package. The path I take is to update the MVC project proir to any package installs:

Install-Package Microsoft.AspNet.Mvc -Version 5.2.3

https://www.nuget.org/packages/microsoft.aspnet.mvc

How to resize image automatically on browser width resize but keep same height?

changing the width of the image will automatically change the height...

how many pictures do you want to have this functionality? If it's a lot and they all have DIFFERENT Heights you should probably just let the height change as well.

Lets say you have 5 images that have height 400px , in your html give those five tags the class of fixed

.fixed { width: 100%; height: 500px !important }

This should let the width change but keep the height the same.

Difference between Node object and Element object?

A node is the generic name for any type of object in the DOM hierarchy. A node could be one of the built-in DOM elements such as document or document.body, it could be an HTML tag specified in the HTML such as <input> or <p> or it could be a text node that is created by the system to hold a block of text inside another element. So, in a nutshell, a node is any DOM object.

An element is one specific type of node as there are many other types of nodes (text nodes, comment nodes, document nodes, etc...).

The DOM consists of a hierarchy of nodes where each node can have a parent, a list of child nodes and a nextSibling and previousSibling. That structure forms a tree-like hierarchy. The document node has the html node as its child. The html node has its list of child nodes (the head node and the body node). The body node would have its list of child nodes (the top level elements in your HTML page) and so on.

So, a nodeList is simply an array-like list of nodes.

An element is a specific type of node, one that can be directly specified in the HTML with an HTML tag and can have properties like an id or a class. can have children, etc... There are other types of nodes such as comment nodes, text nodes, etc... with different characteristics. Each node has a property .nodeType which reports what type of node it is. You can see the various types of nodes here (diagram from MDN):

enter image description here

You can see an ELEMENT_NODE is one particular type of node where the nodeType property has a value of 1.

So document.getElementById("test") can only return one node and it's guaranteed to be an element (a specific type of node). Because of that it just returns the element rather than a list.

Since document.getElementsByClassName("para") can return more than one object, the designers chose to return a nodeList because that's the data type they created for a list of more than one node. Since these can only be elements (only elements typically have a class name), it's technically a nodeList that only has nodes of type element in it and the designers could have made a differently named collection that was an elementList, but they chose to use just one type of collection whether it had only elements in it or not.


EDIT: HTML5 defines an HTMLCollection which is a list of HTML Elements (not any node, only Elements). A number of properties or methods in HTML5 now return an HTMLCollection. While it is very similar in interface to a nodeList, a distinction is now made in that it only contains Elements, not any type of node.

The distinction between a nodeList and an HTMLCollection has little impact on how you use one (as far as I can tell), but the designers of HTML5 have now made that distinction.

For example, the element.children property returns a live HTMLCollection.

Remove lines that contain certain string

You could simply not include the line into the new file instead of doing replace.

for line in infile :
     if 'bad' not in line and 'naughty' not in line:
            newopen.write(line)

Passing Arrays to Function in C++

The question has already been answered, but I thought I'd add an answer with more precise terminology and references to the C++ standard.

Two things are going on here, array parameters being adjusted to pointer parameters, and array arguments being converted to pointer arguments. These are two quite different mechanisms, the first is an adjustment to the actual type of the parameter, whereas the other is a standard conversion which introduces a temporary pointer to the first element.

Adjustments to your function declaration:

dcl.fct#5:

After determining the type of each parameter, any parameter of type “array of T” (...) is adjusted to be “pointer to T”.

So int arg[] is adjusted to be int* arg.

Conversion of your function argument:

conv.array#1

An lvalue or rvalue of type “array of N T” or “array of unknown bound of T” can be converted to a prvalue of type “pointer to T”. The temporary materialization conversion is applied. The result is a pointer to the first element of the array.

So in printarray(firstarray, 3);, the lvalue firstarray of type "array of 3 int" is converted to a prvalue (temporary) of type "pointer to int", pointing to the first element.

Run certain code every n seconds

You can start a separate thread whose sole duty is to count for 5 seconds, update the file, repeat. You wouldn't want this separate thread to interfere with your main thread.

Python add item to the tuple

>>> x = (u'2',)
>>> x += u"random string"

Traceback (most recent call last):
  File "<pyshell#11>", line 1, in <module>
    x += u"random string"
TypeError: can only concatenate tuple (not "unicode") to tuple
>>> x += (u"random string", )  # concatenate a one-tuple instead
>>> x
(u'2', u'random string')

Removing character in list of strings

A faster way is to join the list, replace 8 and split the new string:

mylist = [("aaaa8"),("bb8"),("ccc8"),("dddddd8")]
mylist = ' '.join(mylist).replace('8','').split()
print mylist

Permission denied error on Github Push

For some reason my push and pull origin was changed to HTTPS-url in stead of SSH-url (probably a copy-paste error on my end), but trying to push would give me the following error after trying to login:

Username for 'https://github.com': xxx
Password for 'https://[email protected]': 
remote: Invalid username or password.

Updating the remote origin with the SSH url, solved the problem:

git remote set-url origin [email protected]:<username>/<repo>.git

Hope this helps!

Go / golang time.Now().UnixNano() convert to milliseconds?

I think it's better to round the time to milliseconds before the division.

func makeTimestamp() int64 {
    return time.Now().Round(time.Millisecond).UnixNano() / (int64(time.Millisecond)/int64(time.Nanosecond))
}

Here is an example program:

package main

import (
        "fmt"
        "time"
)

func main() {
        fmt.Println(unixMilli(time.Unix(0, 123400000)))
        fmt.Println(unixMilli(time.Unix(0, 123500000)))
        m := makeTimestampMilli()
        fmt.Println(m)
        fmt.Println(time.Unix(m/1e3, (m%1e3)*int64(time.Millisecond)/int64(time.Nanosecond)))
}

func unixMilli(t time.Time) int64 {
        return t.Round(time.Millisecond).UnixNano() / (int64(time.Millisecond) / int64(time.Nanosecond))
}

func makeTimestampMilli() int64 {
        return unixMilli(time.Now())
}

The above program printed the result below on my machine:

123
124
1472313624305
2016-08-28 01:00:24.305 +0900 JST

illegal character in path

You seem to have the quote marks (") embedded in your string at the start and the end. These are not needed and are illegal characters in a path. How are you initializing the string with the path?

This can be seen from the debugger visualizer, as the string starts with "\" and ends with \"", it shows that the quotes are part of the string, when they shouldn't be.

You can do two thing - a regular escaped string (using \) or a verbatim string literal (that starts with a @):

  string str = "C:\\Program Files (x86)\\test software\\myapp\\demo.exe";

Or:

  string verbatim = @"C:\Program Files (x86)\test software\myapp\demo.exe";

How can I store JavaScript variable output into a PHP variable?

If this is related to a form submission, use a hidden inputinside the form and change the hidden input value to this variable value. Then you can get that hidden input value in the php page and assign it to your php variable after form submission.

Update:

According to your edit, it seems you don't understand how javascript and php works. Javascript is a client side language, and php is a serverside language. Therefore you cannot execute javascript logic and use that variable value to a php variable when you execute relevant page in the server. You can run the relevant javascript logic after client browser process the web page returned from the web server (which has already executed the php code for the relevant page). After the execution of the javascript code and after assigning the relevant value to the relevant javascript variable, you can use form submission or ajax to send that javascript variable value to use by another php page (or a request to process and get the same php page).

Center a column using Twitter Bootstrap 3

<div class="container-fluid">
    <div class="row">
        <div class="col-lg-4 col-lg-offset-4">
            <img src="some.jpg">
        </div>
    </div>
</div>

Center Div inside another (100% width) div

Just add margin: 0 auto; to the inside div.

Ruby on Rails: Clear a cached page

This line in development.rb ensures that caching is not happening.

config.action_controller.perform_caching             = false

You can clear the Rails cache with

Rails.cache.clear

That said - I am not convinced this is a caching issue. Are you making changes to the page and not seeing them reflected? You aren't perhaps looking at the live version of that page? I have done that once (blush).

Update:

You can call that command from in the console. Are you sure you are running the application in development?

The only alternative is that the page that you are trying to render isn't the page that is being rendered.

If you watch the server output you should be able to see the render command when the page is rendered similar to this:

Rendered shared_partials/_latest_featured_video (31.9ms)
Rendered shared_partials/_s_invite_friends (2.9ms)
Rendered layouts/_sidebar (2002.1ms)
Rendered layouts/_footer (2.8ms)
Rendered layouts/_busy_indicator (0.6ms)

Powershell equivalent of bash ampersand (&) for forking/running background processes

As long as the command is an executable or a file that has an associated executable, use Start-Process (available from v2):

Start-Process -NoNewWindow ping google.com

You can also add this as a function in your profile:

function bg() {Start-Process -NoNewWindow @args}

and then the invocation becomes:

bg ping google.com

In my opinion, Start-Job is an overkill for the simple use case of running a process in the background:

  1. Start-Job does not have access to your existing scope (because it runs in a separate session). You cannot do "Start-Job {notepad $myfile}"
  2. Start-Job does not preserve the current directory (because it runs in a separate session). You cannot do "Start-Job {notepad myfile.txt}" where myfile.txt is in the current directory.
  3. The output is not displayed automatically. You need to run Receive-Job with the ID of the job as parameter.

NOTE: Regarding your initial example, "bg sleep 30" would not work because sleep is a Powershell commandlet. Start-Process only works when you actually fork a process.

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

The StartsWith method will be faster, as there is no overhead of interpreting a regular expression, but here is how you do it:

if (Regex.IsMatch(theString, "^(mailto|ftp|joe):")) ...

The ^ mathes the start of the string. You can put any protocols between the parentheses separated by | characters.

edit:

Another approach that is much faster, is to get the start of the string and use in a switch. The switch sets up a hash table with the strings, so it's faster than comparing all the strings:

int index = theString.IndexOf(':');
if (index != -1) {
  switch (theString.Substring(0, index)) {
    case "mailto":
    case "ftp":
    case "joe":
      // do something
      break;
  }
}

Adding elements to object

With that row

var element = {};

you define element to be a plain object. The native JavaScript object has no push() method. To add new items to a plain object use this syntax:

element[ yourKey ] = yourValue;

On the other hand you could define element as an array using

var element = [];

Then you can add elements using push().

Android - Using Custom Font

  • Open your project and select Project on the top left
  • app --> src --> main
  • right click to main and create directory name it as assets
  • right click to assest and create new directory name it fonts
  • you need to find free fonts like free fonts
  • give it to your Textview and call it in your Activity class
  • copy your fonts inside the fonts folder
  • TextView txt = (TextView) findViewById(R.id.txt_act_spalsh_welcome); Typeface font = Typeface.createFromAsset(getAssets(), "fonts/Aramis Italic.ttf"); txt.setTypeface(font);

name of the font must be correct and have fun

How can I tell gcc not to inline a function?

You want the gcc-specific noinline attribute.

This function attribute prevents a function from being considered for inlining. If the function does not have side-effects, there are optimizations other than inlining that causes function calls to be optimized away, although the function call is live. To keep such calls from being optimized away, put asm ("");

Use it like this:

void __attribute__ ((noinline)) foo() 
{
  ...
}

Pass command parameter to method in ViewModel in WPF?

Just using Data Binding syntax. For example,

<Button x:Name="btn" 
         Content="Click" 
         Command="{Binding ClickCmd}" 
         CommandParameter="{Binding ElementName=btn,Path=Content}" /> 

Not only can we use Data Binding to get some data from View Models, but also pass data back to View Models. In CommandParameter, must use ElementName to declare binding source explicitly.

Group query results by month and year in postgresql

Postgres has few types of timestamps:

timestamp without timezone - (Preferable to store UTC timestamps) You find it in multinational database storage. The client in this case will take care of the timezone offset for each country.

timestamp with timezone - The timezone offset is already included in the timestamp.

In some cases, your database does not use the timezone but you still need to group records in respect with local timezone and Daylight Saving Time (e.g. https://www.timeanddate.com/time/zone/romania/bucharest)

To add timezone you can use this example and replace the timezone offset with yours.

"your_date_column" at time zone '+03'

To add the +1 Summer Time offset specific to DST you need to check if your timestamp falls into a Summer DST. As those intervals varies with 1 or 2 days, I will use an aproximation that does not affect the end of month records, so in this case i can ignore each year exact interval.

If more precise query has to be build, then you have to add conditions to create more cases. But roughly, this will work fine in splitting data per month in respect with timezone and SummerTime when you find timestamp without timezone in your database:

SELECT 
    "id", "Product", "Sale",
    date_trunc('month', 
        CASE WHEN 
            Extract(month from t."date") > 03 AND
            Extract(day from t."date") > 26 AND
            Extract(hour from t."date") > 3 AND
            Extract(month from t."date") < 10 AND
            Extract(day from t."date") < 29 AND
            Extract(hour from t."date") < 4
        THEN 
            t."date" at time zone '+03' -- Romania TimeZone offset + DST
        ELSE
            t."date" at time zone '+02' -- Romania TimeZone offset 
        END) as "date"
FROM 
    public."Table" AS t
WHERE 1=1
    AND t."date" >= '01/07/2015 00:00:00'::TIMESTAMP WITHOUT TIME ZONE
    AND t."date" < '01/07/2017 00:00:00'::TIMESTAMP WITHOUT TIME ZONE
GROUP BY date_trunc('month', 
    CASE WHEN 
        Extract(month from t."date") > 03 AND
        Extract(day from t."date") > 26 AND
        Extract(hour from t."date") > 3 AND
        Extract(month from t."date") < 10 AND
        Extract(day from t."date") < 29 AND
        Extract(hour from t."date") < 4
    THEN 
        t."date" at time zone '+03' -- Romania TimeZone offset + DST
    ELSE
        t."date" at time zone '+02' -- Romania TimeZone offset 
    END)

How to trigger an event after using event.preventDefault()

Another solution is to use window.setTimeout in the event listener and execute the code after the event's process has finished. Something like...

window.setTimeout(function() {
  // do your thing
}, 0);

I use 0 for the period since I do not care about waiting.

Command to open file with git

You must have an application associated with the file type. You must be in the folder that houses the file. In gitbash: start file.extension

Is there a way to pass javascript variables in url?

Try this:

 window.location.href = "http://www.gorissen.info/Pierre/maps/googleMapLocation.php?lat="+elemA+"&lon="+elemB+"&setLatLon=Set";

To put a variable in a string enclose the variable in quotes and addition signs like this:

var myname = "BOB";
var mystring = "Hi there "+myname+"!"; 

Just remember that one rule!

The database cannot be opened because it is version 782. This server supports version 706 and earlier. A downgrade path is not supported

For me using solution provided by codedom did not worked. Here we can only changed compatibility version of exiting database.

But actual problem lies that, internal database version which do not matches due to changes in there storage format.

Check out more details about SQL Server version and their internal db version & Db compatibility level here So it would be good if you create your database using SQL Server 2012 Express version or below. Or start using Visual Studio 2015 Preview.

WordPress is giving me 404 page not found for all pages except the homepage

Just Navigate to Settings->Permalink in your dashboard and then Save Changes button in the last.\

Babel 6 regeneratorRuntime is not defined

Babel 7 Users

I had some trouble getting around this since most information was for prior babel versions. For Babel 7, install these two dependencies:

npm install --save @babel/runtime 
npm install --save-dev @babel/plugin-transform-runtime

And, in .babelrc, add:

{
    "presets": ["@babel/preset-env"],
    "plugins": [
        ["@babel/transform-runtime"]
    ]
}

Typescript : Property does not exist on type 'object'

If your object could contain any key/value pairs, you could declare an interface called keyable like :

interface keyable {
    [key: string]: any  
}

then use it as follows :

let countryProviders: keyable[];

or

let countryProviders: Array<keyable>;

What's the difference between utf8_general_ci and utf8_unicode_ci?

There are two big difference the sorting and the character matching:

Sorting:

  • utf8mb4_general_ci removes all accents and sorts one by one which may create incorrect sort results.
  • utf8mb4_unicode_ci sorts accurate.

Character Matching

They match characters differently.

For example, in utf8mb4_unicode_ci you have i != i, but in utf8mb4_general_ci it holds i=i.

For example, imagine you have a row with name="Yilmaz". Then

select id from users where name='Yilmaz';

would return the row if collocation is utf8mb4_general_ci, but if it is collocated with utf8mb4_unicode_ci it would not return the row!

On the other hand we have that a=ª and ß=ss in utf8mb4_unicode_ci which is not the case in utf8mb4_general_ci. So imagine you have a row with name="ªßi", then

select id from users where name='assi';

would return the row if collocation is utf8mb4_unicode_ci, but would not return a row if collocation is set to utf8mb4_general_ci.

A full list of matches for each collocation may be found here.

Convert XML to JSON (and back) using Javascript

I think this is the best one: Converting between XML and JSON

Be sure to read the accompanying article on the xml.com O'Reilly site, which goes into details of the problems with these conversions, which I think you will find enlightening. The fact that O'Reilly is hosting the article should indicate that Stefan's solution has merit.

Can't import javax.servlet.annotation.WebServlet

Simply add the below to your maven project pom.xml flie:

<dependencies>
          <dependency>
            <groupId>javax</groupId>
            <artifactId>javaee-web-api</artifactId>
            <version>6.0</version>
            <scope>provided</scope>
         </dependency>
  </dependencies>

Using Tkinter in python to edit the title bar

widget.winfo_toplevel().title("My_Title")

changes the title of either Tk or Toplevel instance that the widget is a child of.

What does "select count(1) from table_name" on any database tables mean?

The parameter to the COUNT function is an expression that is to be evaluated for each row. The COUNT function returns the number of rows for which the expression evaluates to a non-null value. ( * is a special expression that is not evaluated, it simply returns the number of rows.)

There are two additional modifiers for the expression: ALL and DISTINCT. These determine whether duplicates are discarded. Since ALL is the default, your example is the same as count(ALL 1), which means that duplicates are retained.

Since the expression "1" evaluates to non-null for every row, and since you are not removing duplicates, COUNT(1) should always return the same number as COUNT(*).

Hibernate: hbm2ddl.auto=update in production?

Applications' schema may evolve in time; if you have several installations, which may be at different versions, you should have some way to ensure that your application, some kind of tool or script is capable of migrating schema and data from one version stepwise to any following one.

Having all your persistence in Hibernate mappings (or annotations) is a very good way for keeping schema evolution under control.

You should consider that schema evolution has several aspects to be considered:

  1. evolution of the database schema in adding more columns and tables

  2. dropping of old columns, tables and relations

  3. filling new columns with defaults

Hibernate tools are important in particular in case (like in my experience) you have different versions of the same application on many different kinds of databases.

Point 3 is very sensitive in case you are using Hibernate, as in case you introduce a new boolean valued property or numeric one, if Hibernate will find any null value in such columns, if will raise an exception.

So what I would do is: do indeed use the Hibernate tools capacity of schema update, but you must add alongside of it some data and schema maintenance callback, like for filling defaults, dropping no longer used columns, and similar. In this way you get the advantages (database independent schema update scripts and avoiding duplicated coding of the updates, in peristence and in scripts) but you also cover all the aspects of the operation.

So for example if a version update consists simply in adding a varchar valued property (hence column), which may default to null, with auto update you'll be done. Where more complexity is necessary, more work will be necessary.

This is assuming that the application when updated is capable of updating its schema (it can be done), which also means that it must have the user rights to do so on the schema. If the policy of the customer prevents this (likely Lizard Brain case), you will have to provide the database - specific scripts.

Generating an array of letters in the alphabet

I don't think there is a built in way, but I think the easiest would be

  char[] alpha = "ABCDEFGHIJKLMNOPQRSTUVWXYZ".ToCharArray();

Valid characters of a hostname?

If you're registering a domain and the termination (ex .com) it is not IDN, as Aaron Hathaway said: Hostnames are composed of series of labels concatenated with dots, as are all domain names. For example, en.wikipedia.org is a hostname. Each label must be between 1 and 63 characters long, and the entire hostname (including the delimiting dots but not a trailing dot) has a maximum of 253 ASCII characters.

The Internet standards (Requests for Comments) for protocols mandate that component hostname labels may contain only the ASCII letters a through z (in a case-insensitive manner), the digits 0 through 9, and the hyphen -. The original specification of hostnames in RFC 952, mandated that labels could not start with a digit or with a hyphen, and must not end with a hyphen. However, a subsequent specification (RFC 1123) permitted hostname labels to start with digits. No other symbols, punctuation characters, or white space are permitted.

Later, Spain with it's .es, .com.es, .org.es, .nom,es, .gob.es and .edu.es introduced IDN tlds, if your tld is one of .es or any other that supports it, any character can be used, but you can't combine alphabets like Latin, Greek or Cyril in one hostname, and that it respects the things that can't go at the start or at the end.

If you're using non-registered tlds, just for local networking, like with local DNS or with hosts files, you can treat them all as IDN.

Keep in mind some programs could not work well, especially old, outdated and unpopular ones.

pandas python how to count the number of records or rows in a dataframe

Simple method to get the records count:

df.count()[0]

Convert columns to string in Pandas

Here's the other one, particularly useful to convert the multiple columns to string instead of just single column:

In [76]: import numpy as np
In [77]: import pandas as pd
In [78]: df = pd.DataFrame({
    ...:     'A': [20, 30.0, np.nan],
    ...:     'B': ["a45a", "a3", "b1"],
    ...:     'C': [10, 5, np.nan]})
    ...: 

In [79]: df.dtypes ## Current datatype
Out[79]: 
A    float64
B     object
C    float64
dtype: object

## Multiple columns string conversion
In [80]: df[["A", "C"]] = df[["A", "C"]].astype(str) 

In [81]: df.dtypes ## Updated datatype after string conversion
Out[81]: 
A    object
B    object
C    object
dtype: object

Force sidebar height 100% using CSS (with a sticky bottom image)?

I was facing the same problem as Jon. TheLibzter put me on the right track, but the image that has to stay at the bottom of the sidebar was not included. So I made some adjustments...

Important:

  • Positioning of the div which contains the sidebar and the content (#bodyLayout). This should be relative.
  • Positioning of the div that has to stay at the bottom of the sidbar (#sidebarBottomDiv). This should be absolute.
  • The width of the content + the width of the sidebar must be equal to the width of the page (#container)

Here's the css:

    #container
    {
        margin: auto;
        width: 940px;
    }
    #bodyLayout
    {
        position: relative;
        width: 100%;
        padding: 0;
    }
    #header
    {
        height: 95px;
        background-color: blue;
        color: white;
    }
    #sidebar
    {
        background-color: yellow;
    }
    #sidebarTopDiv
    {
        float: left;
        width: 245px;
        color: black;
    }
    #sidebarBottomDiv
    {
        position: absolute;
        float: left;
        bottom: 0;
        width: 245px;
        height: 100px;
        background-color: green;
        color: white;
    }
    #content
    {
        float: right;
        min-height: 250px;
        width: 695px;
        background-color: White;
    }
    #footer
    {
        width: 940px;
        height: 75px;
        background-color: red;
        color: white;
    }
    .clear
    {
        clear: both;
    }

And here's the html:

<div id="container">
    <div id="header">
        This is your header!
    </div>
    <div id="bodyLayout">
        <div id="sidebar">
            <div id="sidebarTopDiv">
                This is your sidebar!                   
            </div>
            <div id="content">                  
            This is your content!<br />
            The minimum height of the content is set to 250px so the div at the bottom of
            the sidebar will not overlap the top part of the sidebar.
            </div>
            <div id="sidebarBottomDiv">
                This is the div that will stay at the bottom of your footer!
            </div>
            <div class="clear" />
        </div>
    </div>
</div>
<div id="footer">
    This is your footer!
</div>

Passing by reference in C

Because you're passing the value of the pointer to the method and then dereferencing it to get the integer that is pointed to.

Confirmation before closing of tab/browser

Try this:

<script>
window.onbeforeunload = function (e) {
    e = e || window.event;

    // For IE and Firefox prior to version 4
    if (e) {
        e.returnValue = 'Sure?';
    }

    // For Safari
    return 'Sure?';
};
</script>

Here is a working jsFiddle

Can an html element have multiple ids?

My understanding has always been:

  • ID's are single use and are only applied to one element...

    • Each is attributed as a Unique Identifier to (only) one single element.
  • Classes can be used more than once...

    • They can therefore be applied to more than one element, and similarly yet different, there can be more than one class (i.e. multiple classes) per element.

Giving my function access to outside variable

By default, when you are inside a function, you do not have access to the outer variables.


If you want your function to have access to an outer variable, you have to declare it as global, inside the function :

function someFuntion(){
    global $myArr;
    $myVal = //some processing here to determine value of $myVal
    $myArr[] = $myVal;
}

For more informations, see Variable scope.

But note that using global variables is not a good practice : with this, your function is not independant anymore.


A better idea would be to make your function return the result :

function someFuntion(){
    $myArr = array();       // At first, you have an empty array
    $myVal = //some processing here to determine value of $myVal
    $myArr[] = $myVal;      // Put that $myVal into the array
    return $myArr;
}

And call the function like this :

$result = someFunction();


Your function could also take parameters, and even work on a parameter passed by reference :

function someFuntion(array & $myArr){
    $myVal = //some processing here to determine value of $myVal
    $myArr[] = $myVal;      // Put that $myVal into the array
}

Then, call the function like this :

$myArr = array( ... );
someFunction($myArr);  // The function will receive $myArr, and modify it

With this :

  • Your function received the external array as a parameter
  • And can modify it, as it's passed by reference.
  • And it's better practice than using a global variable : your function is a unit, independant of any external code.


For more informations about that, you should read the Functions section of the PHP manual, and,, especially, the following sub-sections :

Push method in React Hooks (useState)?

To expand a little further, here are some common examples. Starting with:

const [theArray, setTheArray] = useState(initialArray);
const [theObject, setTheObject] = useState(initialObject);

Push element at end of array

setTheArray(prevArray => [...prevArray, newValue])

Push/update element at end of object

setTheObject(prevState => ({ ...prevState, currentOrNewKey: newValue}));

Push/update element at end of array of objects

setTheArray(prevState => [...prevState, {currentOrNewKey: newValue}]);

Push element at end of object of arrays

let specificArrayInObject = theObject.array.slice();
specificArrayInObject.push(newValue);
const newObj = { ...theObject, [event.target.name]: specificArrayInObject };
theObject(newObj);

Here are some working examples too. https://codesandbox.io/s/reacthooks-push-r991u

Expected response code 250 but got code "535", with message "535-5.7.8 Username and Password not accepted

This is my .env mail settings

MAIL_DRIVER=smtp
MAIL_HOST=smtp.googlemail.com
MAIL_PORT=587
[email protected]
MAIL_PASSWORD=hello27
MAIL_ENCRYPTION=tls

i was getting thesame error as stated in the question but by using

php artisan config:cache

Everything worked fine

adding noise to a signal in python

Awesome answers above. I recently had a need to generate simulated data and this is what I landed up using. Sharing in-case helpful to others as well,

import logging
__name__ = "DataSimulator"
logging.basicConfig(level=logging.INFO)
logger = logging.getLogger(__name__)

import numpy as np
import pandas as pd

def generate_simulated_data(add_anomalies:bool=True, random_state:int=42):
    rnd_state = np.random.RandomState(random_state)
    time = np.linspace(0, 200, num=2000)
    pure = 20*np.sin(time/(2*np.pi))

    # concatenate on the second axis; this will allow us to mix different data 
    # distribution
    data = np.c_[pure]
    mu = np.mean(data)
    sd = np.std(data)
    logger.info(f"Data shape : {data.shape}. mu: {mu} with sd: {sd}")
    data_df = pd.DataFrame(data, columns=['Value'])
    data_df['Index'] = data_df.index.values

    # Adding gaussian jitter
    jitter = 0.3*rnd_state.normal(mu, sd, size=data_df.shape[0])
    data_df['with_jitter'] = data_df['Value'] + jitter

    index_further_away = None
    if add_anomalies:
        # As per the 68-95-99.7 rule(also known as the empirical rule) mu+-2*sd 
        # covers 95.4% of the dataset.
        # Since, anomalies are considered to be rare and typically within the 
        # 5-10% of the data; this filtering
        # technique might work 
        #for us(https://en.wikipedia.org/wiki/68%E2%80%9395%E2%80%9399.7_rule)
        indexes_furhter_away = np.where(np.abs(data_df['with_jitter']) > (mu + 
         2*sd))[0]
        logger.info(f"Number of points further away : 
        {len(indexes_furhter_away)}. Indexes: {indexes_furhter_away}")
        # Generate a point uniformly and embed it into the dataset
        random = rnd_state.uniform(0, 5, 1)
        data_df.loc[indexes_furhter_away, 'with_jitter'] +=  
        random*data_df.loc[indexes_furhter_away, 'with_jitter']
    return data_df, indexes_furhter_away

What is the list of supported languages/locales on Android?

Arabic, Egypt (ar_EG)
Arabic, Israel (ar_IL)
Bulgarian, Bulgaria (bg_BG)
Catalan, Spain (ca_ES)
Czech, Czech Republic (cs_CZ)
Danish, Denmark(da_DK)
German, Austria (de_AT)
German, Switzerland (de_CH)
German, Germany (de_DE)
German, Liechtenstein (de_LI)
Greek, Greece (el_GR)
English, Australia (en_AU)
English, Canada (en_CA)
English, Britain (en_GB)
English, Ireland (en_IE)
English, India (en_IN)
English, New Zealand (en_NZ)
English, Singapore(en_SG)
English, US (en_US)
English, South Africa (en_ZA)
Spanish (es_ES)
Spanish, US (es_US)
Finnish, Finland (fi_FI)
French, Belgium (fr_BE)
French, Canada (fr_CA)
French, Switzerland (fr_CH)
French, France (fr_FR)
Hebrew, Israel (he_IL)
Hindi, India (hi_IN)
Croatian, Croatia (hr_HR)
Hungarian, Hungary (hu_HU)
Indonesian, Indonesia (id_ID)
Italian, Switzerland (it_CH)
Italian, Italy (it_IT)
Japanese (ja_JP)
Korean (ko_KR)
Lithuanian, Lithuania (lt_LT)
Latvian, Latvia (lv_LV)
Norwegian bokmål, Norway (nb_NO)
Dutch, Belgium (nl_BE)
Dutch, Netherlands (nl_NL)
Polish (pl_PL)
Portuguese, Brazil (pt_BR)
Portuguese, Portugal (pt_PT)
Romanian, Romania (ro_RO)
Russian (ru_RU)
Slovak, Slovakia (sk_SK)
Slovenian, Slovenia (sl_SI)
Serbian (sr_RS)
Swedish, Sweden (sv_SE)
Thai, Thailand (th_TH)
Tagalog, Philippines (tl_PH)
Turkish, Turkey (tr_TR)
Ukrainian, Ukraine (uk_UA)
Vietnamese, Vietnam (vi_VN)
Chinese, PRC (zh_CN)
Chinese, Taiwan (zh_TW)

Android button onClickListener

This task can be accomplished using one of the android's main building block named as Intents and One of the methods public void startActivity (Intent intent) which belongs to your Activity class.

An intent is an abstract description of an operation to be performed. It can be used with startActivity to launch an Activity, broadcastIntent to send it to any interested BroadcastReceiver components, and startService(Intent) or bindService(Intent, ServiceConnection, int) to communicate with a background Service.

An Intent provides a facility for performing late runtime binding between the code in different applications. Its most significant use is in the launching of activities, where it can be thought of as the glue between activities. It is basically a passive data structure holding an abstract description of an action to be performed.

Refer the official docs -- http://developer.android.com/reference/android/content/Intent.html

public void startActivity (Intent intent) -- Used to launch a new activity.

So suppose you have two Activity class --

  1. PresentActivity -- This is your current activity from which you want to go the second activity.

  2. NextActivity -- This is your next Activity on which you want to move.

So the Intent would be like this

Intent(PresentActivity.this, NextActivity.class)

Finally this will be the complete code

public class PresentActivity extends Activity {
  protected void onCreate(Bundle icicle) {
    super.onCreate(icicle);

    setContentView(R.layout.content_layout_id);

    final Button button = (Button) findViewById(R.id.button_id);
    button.setOnClickListener(new View.OnClickListener() {
            public void onClick(View v) {
              // Perform action on click   
              Intent activityChangeIntent = new Intent(PresentActivity.this, NextActivity.class);

              // currentContext.startActivity(activityChangeIntent);

              PresentActivity.this.startActivity(activityChangeIntent);
            }
          });
  }
}

How to move an element into another element?

If you want a quick demo and more details about how you move elements, try this link:

http://html-tuts.com/move-div-in-another-div-with-jquery


Here is a short example:

To move ABOVE an element:

$('.whatToMove').insertBefore('.whereToMove');

To move AFTER an element:

$('.whatToMove').insertAfter('.whereToMove');

To move inside an element, ABOVE ALL elements inside that container:

$('.whatToMove').prependTo('.whereToMove');

To move inside an element, AFTER ALL elements inside that container:

$('.whatToMove').appendTo('.whereToMove');

Inline labels in Matplotlib

A simpler approach like the one Ioannis Filippidis do :

import matplotlib.pyplot as plt
import numpy as np

# evenly sampled time at 200ms intervals
tMin=-1 ;tMax=10
t = np.arange(tMin, tMax, 0.1)

# red dashes, blue points default
plt.plot(t, 22*t, 'r--', t, t**2, 'b')

factor=3/4 ;offset=20  # text position in view  
textPosition=[(tMax+tMin)*factor,22*(tMax+tMin)*factor]
plt.text(textPosition[0],textPosition[1]+offset,'22  t',color='red',fontsize=20)
textPosition=[(tMax+tMin)*factor,((tMax+tMin)*factor)**2+20]
plt.text(textPosition[0],textPosition[1]+offset, 't^2', bbox=dict(facecolor='blue', alpha=0.5),fontsize=20)
plt.show()

code python 3 on sageCell

CreateProcess: No such file or directory

This problem is because you use uppercase suffix stuff.C rather than lowercase stuff.c when you compile it with Mingw GCC. For example, when you do like this:

gcc -o stuff stuff.C

then you will get the message: gcc: CreateProcess: No such file or directory

But if you do this:

 gcc -o stuff stuff.c

then it works. I just don't know why.

Visual Studio Code PHP Intelephense Keep Showing Not Necessary Error

This is really a set of configurations for your editor to understand Laravel.

If you want to configure it all manually, here is the repo. This is for both VS code and PhpStorm.

Or if you want you can download this package.(I created) recommended to install it globally.

And then just run andylaravel setupIDE. this will configure everything for you according to the fist repo.

Center align a column in twitter bootstrap

With bootstrap 3 the best way to go about achieving what you want is ...with offsetting columns. Please see these examples for more detail:
http://getbootstrap.com/css/#grid-offsetting

In short, and without seeing your divs here's an example what might help, without using any custom classes. Just note how the "col-6" is used and how half of that is 3 ...so the "offset-3" is used. Splitting equally will allow the centered spacing you're going for:

<div class="container">
<div class="col-sm-6 col-sm-offset-3">
your centered, floating column
</div></div>

importing pyspark in python shell

By exporting the SPARK path and the Py4j path, it started to work:

export SPARK_HOME=/usr/local/Cellar/apache-spark/1.5.1
export PYTHONPATH=$SPARK_HOME/libexec/python:$SPARK_HOME/libexec/python/build:$PYTHONPATH
PYTHONPATH=$SPARK_HOME/python/lib/py4j-0.8.2.1-src.zip:$PYTHONPATH 
export PYTHONPATH=$SPARK_HOME/python:$SPARK_HOME/python/build:$PYTHONPATH

So, if you don't want to type these everytime you want to fire up the Python shell, you might want to add it to your .bashrc file

Eliminating duplicate values based on only one column of the table

This is where the window function row_number() comes in handy:

SELECT s.siteName, s.siteIP, h.date
FROM sites s INNER JOIN
     (select h.*, row_number() over (partition by siteName order by date desc) as seqnum
      from history h
     ) h
    ON s.siteName = h.siteName and seqnum = 1
ORDER BY s.siteName, h.date

Spring 5.0.3 RequestRejectedException: The request was rejected because the URL was not normalized

In my case, upgraded from spring-securiy-web 3.1.3 to 4.2.12, the defaultHttpFirewall was changed from DefaultHttpFirewall to StrictHttpFirewall by default. So just define it in XML configuration like below:

<bean id="defaultHttpFirewall" class="org.springframework.security.web.firewall.DefaultHttpFirewall"/>
<sec:http-firewall ref="defaultHttpFirewall"/>

set HTTPFirewall as DefaultHttpFirewall

Unable to obtain LocalDateTime from TemporalAccessor when parsing LocalDateTime (Java 8)

Try this one:

DateTimeFormatter dateTimeFormatter = DateTimeFormatter.ofPattern("MM-dd-yyyy"); 
LocalDate fromLocalDate = LocalDate.parse(fromdstrong textate, dateTimeFormatter);

You can add any format you want. That works for me!

What is the SSIS package and what does it do?

For Latest Info About SSIS > https://docs.microsoft.com/en-us/sql/integration-services/sql-server-integration-services

From the above referenced site:

Microsoft Integration Services is a platform for building enterprise-level data integration and data transformations solutions. Use Integration Services to solve complex business problems by copying or downloading files, loading data warehouses, cleansing and mining data, and managing SQL Server objects and data.

Integration Services can extract and transform data from a wide variety of sources such as XML data files, flat files, and relational data sources, and then load the data into one or more destinations.

Integration Services includes a rich set of built-in tasks and transformations, graphical tools for building packages, and the Integration Services Catalog database, where you store, run, and manage packages.

You can use the graphical Integration Services tools to create solutions without writing a single line of code. You can also program the extensive Integration Services object model to create packages programmatically and code custom tasks and other package objects.

Getting Started with SSIS - http://msdn.microsoft.com/en-us/sqlserver/bb671393.aspx

If you are Integration Services Information Worker - http://msdn.microsoft.com/en-us/library/ms141667.aspx

If you are Integration Services Administrator - http://msdn.microsoft.com/en-us/library/ms137815.aspx

If you are Integration Services Developer - http://msdn.microsoft.com/en-us/library/ms137709.aspx

If you are Integration Services Architect - http://msdn.microsoft.com/en-us/library/ms142161.aspx

Overview of SSIS - http://msdn.microsoft.com/en-us/library/ms141263.aspx

Integration Services How-to Topics - http://msdn.microsoft.com/en-us/library/ms141767.aspx

How do I get the fragment identifier (value after hash #) from a URL?

Based on A.K's code, here is a Helper Function. JS Fiddle Here (http://jsfiddle.net/M5vsL/1/) ...

// Helper Method Defined Here.
(function (helper, $) {
    // This is now a utility function to "Get the Document Hash"
    helper.getDocumentHash = function (urlString) {
        var hashValue = "";

        if (urlString.indexOf('#') != -1) {
            hashValue = urlString.substring(parseInt(urlString.indexOf('#')) + 1);
        }
        return hashValue;
    };
})(this.helper = this.helper || {}, jQuery);

Subset and ggplot2

There's another solution that I find useful, especially when I want to plot multiple subsets of the same object:

myplot<-ggplot(df)+geom_line(aes(Value1, Value2, group=ID, colour=ID))
myplot %+% subset(df, ID %in% c("P1","P3"))
myplot %+% subset(df, ID %in% c("P2"))

how to get the ipaddress of a virtual box running on local machine

Login to virtual machine use below command to check ip address. (anyone will work)

  1. ifconfig
  2. ip addr show

If you used NAT for your virtual machine settings(your machine ip will be 10.0.2.15), then you have to use port forwarding to connect to machine. IP address will be 127.0.0.1

If you used bridged networking/Host only networking, then you will have separate Ip address. Use that IP address to connect virtual machine

how to destroy bootstrap modal window completely?

With ui-router this may be an option for you. It reloads the controller on close so reinitializes the modal contents before it fires next time.

$("#myModalId").on('hidden.bs.modal', function () {
  $state.reload();  //resets the modal
});

How do I close an open port from the terminal on the Mac?

However you opened the port, you close it in the same way. For example, if you created a socket, bound it to port 0.0.0.0:5955, and called listen, close that same socket.

You can also just kill the process that has the port open.

If you want to find out what process has a port open, try this:

lsof -i :5955

If you want to know whether a port is open, you can do the same lsof command (if any process has it open, it's open; otherwise, it's not), or you can just try to connect to it, e.g.:

nc localhost 5955

If it returns immediately with no output, the port isn't open.

It may be worth mentioning that, technically speaking, it's not a port that's open, but a host:port combination. For example, if you're plugged into a LAN as 10.0.1.2, you could bind a socket to 127.0.0.1:5955, or 10.0.1.2:5955, without either one affecting the other, or you could bind to 0.0.0.0:5955 to handle both at once. You can see all of your computer's IPv4 and IPv6 addresses with the ifconfig command.

PostgreSQL: role is not permitted to log in

try to run

sudo su - postgres
psql
ALTER ROLE 'dbname'

How to add multiple files to Git at the same time

step1.

git init

step2.

a) for all files

git add -a

b) only specific folder

git add <folder1> <folder2> <etc.>

step3.

git commit -m "Your message about the commit"

step4.

enter image description here

git remote add origin https://github.com/yourUsername/yourRepository.git

step5.

git push -u origin master
git push origin master

if you are face this error than

 ! [rejected]        master -> master (fetch first)
error: failed to push some refs to 'https://github.com/harishkumawat2610/Qt5-with-C-plus-plus.git'
hint: Updates were rejected because the remote contains work that you do
hint: not have locally. This is usually caused by another repository pushing
hint: to the same ref. You may want to first integrate the remote changes
hint: (e.g., 'git pull ...') before pushing again.
hint: See the 'Note about fast-forwards' in 'git push --help' for details.

Use this command

git push --force origin master

How the single threaded non blocking IO model works in Node.js

Node.js is built upon libuv, a cross-platform library that abstracts apis/syscalls for asynchronous (non-blocking) input/output provided by the supported OSes (Unix, OS X and Windows at least).

Asynchronous IO

In this programming model open/read/write operation on devices and resources (sockets, filesystem, etc.) managed by the file-system don't block the calling thread (as in the typical synchronous c-like model) and just mark the process (in kernel/OS level data structure) to be notified when new data or events are available. In case of a web-server-like app, the process is then responsible to figure out which request/context the notified event belongs to and proceed processing the request from there. Note that this will necessarily mean you'll be on a different stack frame from the one that originated the request to the OS as the latter had to yield to a process' dispatcher in order for a single threaded process to handle new events.

The problem with the model I described is that it's not familiar and hard to reason about for the programmer as it's non-sequential in nature. "You need to make request in function A and handle the result in a different function where your locals from A are usually not available."

Node's model (Continuation Passing Style and Event Loop)

Node tackles the problem leveraging javascript's language features to make this model a little more synchronous-looking by inducing the programmer to employ a certain programming style. Every function that requests IO has a signature like function (... parameters ..., callback) and needs to be given a callback that will be invoked when the requested operation is completed (keep in mind that most of the time is spent waiting for the OS to signal the completion - time that can be spent doing other work). Javascript's support for closures allows you to use variables you've defined in the outer (calling) function inside the body of the callback - this allows to keep state between different functions that will be invoked by the node runtime independently. See also Continuation Passing Style.

Moreover, after invoking a function spawning an IO operation the calling function will usually return control to node's event loop. This loop will invoke the next callback or function that was scheduled for execution (most likely because the corresponding event was notified by the OS) - this allows the concurrent processing of multiple requests.

You can think of node's event loop as somewhat similar to the kernel's dispatcher: the kernel would schedule for execution a blocked thread once its pending IO is completed while node will schedule a callback when the corresponding event has occured.

Highly concurrent, no parallelism

As a final remark, the phrase "everything runs in parallel except your code" does a decent job of capturing the point that node allows your code to handle requests from hundreds of thousands open socket with a single thread concurrently by multiplexing and sequencing all your js logic in a single stream of execution (even though saying "everything runs in parallel" is probably not correct here - see Concurrency vs Parallelism - What is the difference?). This works pretty well for webapp servers as most of the time is actually spent on waiting for network or disk (database / sockets) and the logic is not really CPU intensive - that is to say: this works well for IO-bound workloads.

How to write trycatch in R

tryCatch has a slightly complex syntax structure. However, once we understand the 4 parts which constitute a complete tryCatch call as shown below, it becomes easy to remember:

expr: [Required] R code(s) to be evaluated

error : [Optional] What should run if an error occured while evaluating the codes in expr

warning : [Optional] What should run if a warning occured while evaluating the codes in expr

finally : [Optional] What should run just before quitting the tryCatch call, irrespective of if expr ran successfully, with an error, or with a warning

tryCatch(
    expr = {
        # Your code...
        # goes here...
        # ...
    },
    error = function(e){ 
        # (Optional)
        # Do this if an error is caught...
    },
    warning = function(w){
        # (Optional)
        # Do this if an warning is caught...
    },
    finally = {
        # (Optional)
        # Do this at the end before quitting the tryCatch structure...
    }
)

Thus, a toy example, to calculate the log of a value might look like:

log_calculator <- function(x){
    tryCatch(
        expr = {
            message(log(x))
            message("Successfully executed the log(x) call.")
        },
        error = function(e){
            message('Caught an error!')
            print(e)
        },
        warning = function(w){
            message('Caught an warning!')
            print(w)
        },
        finally = {
            message('All done, quitting.')
        }
    )    
}

Now, running three cases:

A valid case

log_calculator(10)
# 2.30258509299405
# Successfully executed the log(x) call.
# All done, quitting.

A "warning" case

log_calculator(-10)
# Caught an warning!
# <simpleWarning in log(x): NaNs produced>
# All done, quitting.

An "error" case

log_calculator("log_me")
# Caught an error!
# <simpleError in log(x): non-numeric argument to mathematical function>
# All done, quitting.

I've written about some useful use-cases which I use regularly. Find more details here: https://rsangole.netlify.com/post/try-catch/

Hope this is helpful.

List of remotes for a Git repository?

The answers so far tell you how to find existing branches:

git branch -r

Or repositories for the same project [see note below]:

git remote -v

There is another case. You might want to know about other project repositories hosted on the same server.

To discover that information, I use SSH or PuTTY to log into to host and ls to find the directories containing the other repositories. For example, if I cloned a repository by typing:

git clone ssh://git.mycompany.com/git/ABCProject

and want to know what else is available, I log into git.mycompany.com via SSH or PuTTY and type:

ls /git

assuming ls says:

 ABCProject DEFProject

I can use the command

 git clone ssh://git.mycompany.com/git/DEFProject

to gain access to the other project.

NOTE: Usually git remote simply tells me about origin -- the repository from which I cloned the project. git remote would be handy if you were collaborating with two or more people working on the same project and accessing each other's repositories directly rather than passing everything through origin.

How to get images in Bootstrap's card to be the same height/width?

.card-img-top {
width: 100%;
height: 30vh;
object-fit: contain;
}

Contain will help in getting Complete Image displayed inside Card.

Adjust height "30vh" according to your need!

SQL Server® 2016, 2017 and 2019 Express full download

Scott Hanselman put together a great summary page with all of the various SQL downloads here https://www.hanselman.com/blog/DownloadSQLServerExpress.aspx.

For offline installers, see this answer https://stackoverflow.com/a/42952186/407188

How do I get rid of the b-prefix in a string in python?

you need to decode the bytes of you want a string:

b = b'1234'
print(b.decode('utf-8'))  # '1234'

How to insert date values into table

insert into run(id,name,dob)values(&id,'&name',[what should I write here?]);

insert into run(id,name,dob)values(&id,'&name',TO_DATE('&dob','YYYY-MM-DD'));

Datatable to html Table

Just in case anyone arrives here and was hoping for VB (I did, and I didn't enter c# as a search term), here's the basics of the first response..

Public Shared Function ConvertDataTableToHTML(dt As DataTable) As String
    Dim html As String = "<table>"
    html += "<tr>"
    For i As Integer = 0 To dt.Columns.Count - 1
        html += "<td>" + System.Web.HttpUtility.HtmlEncode(dt.Columns(i).ColumnName) + "</td>"
    Next
    html += "</tr>"
    For i As Integer = 0 To dt.Rows.Count - 1
        html += "<tr>"
        For j As Integer = 0 To dt.Columns.Count - 1
            html += "<td>" + System.Web.HttpUtility.HtmlEncode(dt.Rows(i)(j).ToString()) + "</td>"
        Next
        html += "</tr>"
    Next
    html += "</table>"
    Return html
End Function

Error Code: 2013. Lost connection to MySQL server during query

New versions of MySQL WorkBench have an option to change specific timeouts.

For me it was under Edit ? Preferences ? SQL Editor ? DBMS connection read time out (in seconds): 600

Changed the value to 6000.

Also unchecked limit rows as putting a limit in every time I want to search the whole data set gets tiresome.

Copy table without copying data

Try:

CREATE TABLE foo SELECT * FROM bar LIMIT 0

Or:

CREATE TABLE foo SELECT * FROM bar WHERE 1=0

Express-js can't GET my static files, why?

In addition to above, make sure the static file path begins with / (ex... /assets/css)... to serve static files in any directory above the main directory (/main)

Convert JSON string to dict using Python

When I started using json, I was confused and unable to figure it out for some time, but finally I got what I wanted
Here is the simple solution

import json
m = {'id': 2, 'name': 'hussain'}
n = json.dumps(m)
o = json.loads(n)
print(o['id'], o['name'])

Is it possible to find out the users who have checked out my project on GitHub?

Go to the traffic section inside graphs. Here you can find how many unique visitors you have. Other than this there is no other way to know who exactly viewed your account.

Can I load a .NET assembly at runtime and instantiate a type knowing only the name?

Yes, it is, you will want to use the static Load method on the Assembly class, and then call then call the CreateInstance method on the Assembly instance returned to you from the call to Load.

Also, you can call one of the other static methods starting with "Load" on the Assembly class, depending on your needs.

What is content-type and datatype in an AJAX request?

See http://api.jquery.com/jQuery.ajax/, there's mention of datatype and contentType there.

They are both used in the request to the server so the server knows what kind of data to receive/send.

Get free disk space

Working code snippet using GetDiskFreeSpaceEx from link by RichardOD.

// Pinvoke for API function
[DllImport("kernel32.dll", SetLastError = true, CharSet = CharSet.Auto)]
[return: MarshalAs(UnmanagedType.Bool)]
public static extern bool GetDiskFreeSpaceEx(string lpDirectoryName,
out ulong lpFreeBytesAvailable,
out ulong lpTotalNumberOfBytes,
out ulong lpTotalNumberOfFreeBytes);

public static bool DriveFreeBytes(string folderName, out ulong freespace)
{
    freespace = 0;
    if (string.IsNullOrEmpty(folderName))
    {
        throw new ArgumentNullException("folderName");
    }

    if (!folderName.EndsWith("\\"))
    {
        folderName += '\\';
    }

    ulong free = 0, dummy1 = 0, dummy2 = 0;

    if (GetDiskFreeSpaceEx(folderName, out free, out dummy1, out dummy2))
    {
        freespace = free;
        return true;
    }
    else
    {
        return false;
    }
}

T-sql - determine if value is integer

I am not a Pro in SQL but what about checking if it is devideable by 1 ? For me it does the job.

SELECT *
FROM table    
WHERE fieldname % 1 = 0

Check if a string contains a string in C++

Actually, you can try to use boost library,I think std::string doesn't supply enough method to do all the common string operation.In boost,you can just use the boost::algorithm::contains:

#include <string>
#include <boost/algorithm/string.hpp>

int main() {
    std::string s("gengjiawen");
    std::string t("geng");
    bool b = boost::algorithm::contains(s, t);
    std::cout << b << std::endl;
    return 0;
}

Powershell folder size of folders without listing Subdirectories

from sysinternals.com with du.exe or du64.exe -l 1 . or 2 levels down: **du -l 2 c:**

Much shorter than Linux though ;)

Checking for empty or null JToken in a JObject

As of C# 7 you could also use this:

if (clientsParsed["objects"] is JArray clients) 
{
    foreach (JObject item in clients.Children())
    {
        if (item["thisParameter"] as JToken itemToken) 
        {
            command.Parameters["@MyParameter"].Value = JTokenToSql(itemToken);
        }
    }
}

The is Operator checks the Type and if its corrects the Value is inside the clients variable.

Get contentEditable caret index position

If you set the editable div style to "display:inline-block; white-space: pre-wrap" you don't get new child divs when you enter a new line, you just get LF character (i.e. &#10);.

_x000D_
_x000D_
function showCursPos(){
    selection = document.getSelection();
    childOffset = selection.focusOffset;
    const range = document.createRange();
    eDiv = document.getElementById("eDiv");
    range.setStart(eDiv, 0);
    range.setEnd(selection.focusNode, childOffset);
    var sHtml = range.toString();
    p = sHtml.length; 
    sHtml=sHtml.replace(/(\r)/gm, "\\r");
    sHtml=sHtml.replace(/(\n)/gm, "\\n");
    document.getElementById("caretPosHtml").value=p;
    document.getElementById("exHtml").value=sHtml;   
  }
_x000D_
click/type in div below:
<br>
<div contenteditable name="eDiv" id="eDiv"  
     onkeyup="showCursPos()" onclick="showCursPos()" 
     style="width: 10em; border: 1px solid; display:inline-block; white-space: pre-wrap; "
     >123&#13;&#10;456&#10;789</div>
<p>
html caret position:<br> <input type="text" id="caretPosHtml">
<p>  
html from start of div:<br> <input type="text" id="exHtml">
_x000D_
_x000D_
_x000D_

What I noticed was when you press "enter" in the editable div, it creates a new node, so the focusOffset resets to zero. This is why I've had to add a range variable, and extend it from the child nodes' focusOffset back to the start of eDiv (and thus capturing all text in-between).

How to enable named/bind/DNS full logging?

I usually expand each log out into it's own channel and then to a separate log file, certainly makes things easier when you are trying to debug specific issues. So my logging section looks like the following:

logging {
    channel default_file {
        file "/var/log/named/default.log" versions 3 size 5m;
        severity dynamic;
        print-time yes;
    };
    channel general_file {
        file "/var/log/named/general.log" versions 3 size 5m;
        severity dynamic;
        print-time yes;
    };
    channel database_file {
        file "/var/log/named/database.log" versions 3 size 5m;
        severity dynamic;
        print-time yes;
    };
    channel security_file {
        file "/var/log/named/security.log" versions 3 size 5m;
        severity dynamic;
        print-time yes;
    };
    channel config_file {
        file "/var/log/named/config.log" versions 3 size 5m;
        severity dynamic;
        print-time yes;
    };
    channel resolver_file {
        file "/var/log/named/resolver.log" versions 3 size 5m;
        severity dynamic;
        print-time yes;
    };
    channel xfer-in_file {
        file "/var/log/named/xfer-in.log" versions 3 size 5m;
        severity dynamic;
        print-time yes;
    };
    channel xfer-out_file {
        file "/var/log/named/xfer-out.log" versions 3 size 5m;
        severity dynamic;
        print-time yes;
    };
    channel notify_file {
        file "/var/log/named/notify.log" versions 3 size 5m;
        severity dynamic;
        print-time yes;
    };
    channel client_file {
        file "/var/log/named/client.log" versions 3 size 5m;
        severity dynamic;
        print-time yes;
    };
    channel unmatched_file {
        file "/var/log/named/unmatched.log" versions 3 size 5m;
        severity dynamic;
        print-time yes;
    };
    channel queries_file {
        file "/var/log/named/queries.log" versions 3 size 5m;
        severity dynamic;
        print-time yes;
    };
    channel network_file {
        file "/var/log/named/network.log" versions 3 size 5m;
        severity dynamic;
        print-time yes;
    };
    channel update_file {
        file "/var/log/named/update.log" versions 3 size 5m;
        severity dynamic;
        print-time yes;
    };
    channel dispatch_file {
        file "/var/log/named/dispatch.log" versions 3 size 5m;
        severity dynamic;
        print-time yes;
    };
    channel dnssec_file {
        file "/var/log/named/dnssec.log" versions 3 size 5m;
        severity dynamic;
        print-time yes;
    };
    channel lame-servers_file {
        file "/var/log/named/lame-servers.log" versions 3 size 5m;
        severity dynamic;
        print-time yes;
    };

    category default { default_file; };
    category general { general_file; };
    category database { database_file; };
    category security { security_file; };
    category config { config_file; };
    category resolver { resolver_file; };
    category xfer-in { xfer-in_file; };
    category xfer-out { xfer-out_file; };
    category notify { notify_file; };
    category client { client_file; };
    category unmatched { unmatched_file; };
    category queries { queries_file; };
    category network { network_file; };
    category update { update_file; };
    category dispatch { dispatch_file; };
    category dnssec { dnssec_file; };
    category lame-servers { lame-servers_file; };
};

Hope this helps.

"Uncaught TypeError: undefined is not a function" - Beginner Backbone.js Application

Uncaught TypeError: undefined is not a function example_app.js:7

This error message tells the whole story. On this line, you are trying to execute a function. However, whatever is being executed is not a function! Instead, it's undefined.

So what's on example_app.js line 7? Looks like this:

var tasks = new ExampleApp.Collections.Tasks(data.tasks);

There is only one function being run on that line. We found the problem! ExampleApp.Collections.Tasks is undefined.

So lets look at where that is declared:

var Tasks = Backbone.Collection.extend({
    model: Task,
    url: '/tasks'
});

If that's all the code for this collection, then the root cause is right here. You assign the constructor to global variable, called Tasks. But you never add it to the ExampleApp.Collections object, a place you later expect it to be.

Change that to this, and I bet you'd be good.

ExampleApp.Collections.Tasks = Backbone.Collection.extend({
    model: Task,
    url: '/tasks'
});

See how important the proper names and line numbers are in figuring this out? Never ever regard errors as binary (it works or it doesn't). Instead read the error, in most cases the error message itself gives you the critical clues you need to trace through to find the real issue.


In Javascript, when you execute a function, it's evaluated like:

expression.that('returns').aFunctionObject(); // js
execute -> expression.that('returns').aFunctionObject // what the JS engine does

That expression can be complex. So when you see undefined is not a function it means that expression did not return a function object. So you have to figure out why what you are trying to execute isn't a function.

And in this case, it was because you didn't put something where you thought you did.

Remove last character of a StringBuilder?

since you know the character you want to remove you can use this

sb.TrimEnd(",");

Can't connect to localhost on SQL Server Express 2012 / 2016

I had a similar problem - maybe my solution will help. I just installed MSSQL EX 2012 (default install) and tried to connect with VS2012 EX. No joy. I then looked at the services, confirmed that SQL Server (SQLEXPRESS) was, indeed running.

However, I saw another interesting service called SQL Server Browser that was disabled. I enabled it, fired it and was then able to retrieve the server name in a new connection in VS2012 EX and connect.

Odd that they would disable a service required for VS to connect.

Reset CSS display property to default value

Unset display:

You can use the value unset which works in both Firefox and Chrome.

display: unset;

.foo     { display: none;  }
.foo.bar { display: unset; }

How to get JS variable to retain value after page refresh?

You will have to use cookie to store the value across page refresh. You can use any one of the many javascript based cookie libraries to simplify the cookie access, like this one

If you want to support only html5 then you can think of Storage api like localStorage/sessionStorage

Ex: using localStorage and cookies library

var mode = getStoredValue('myPageMode');

function buttonClick(mode) {
    mode = mode;
    storeValue('myPageMode', mode);
}

function storeValue(key, value) {
    if (localStorage) {
        localStorage.setItem(key, value);
    } else {
        $.cookies.set(key, value);
    }
}

function getStoredValue(key) {
    if (localStorage) {
        return localStorage.getItem(key);
    } else {
        return $.cookies.get(key);
    }
}

MVC4 DataType.Date EditorFor won't display date value in Chrome, fine in Internet Explorer

In MVC 3 I had to add:

using System.ComponentModel.DataAnnotations;

among usings when adding properties:

[DataType(DataType.Date)]
[DisplayFormat(DataFormatString = "{0:yyyy-MM-dd}", ApplyFormatInEditMode = true)]

Especially if you are adding these properties in .edmx file like me. I found that by default .edmx files don't have this using so adding only propeties is not enough.

How to pass an object from one activity to another on Android

  • Using global static variables is not good software engineering practice.
  • Converting an object's fields into primitive data types can be a hectic job.
  • Using serializable is OK, but it's not performance-efficient on the Android platform.
  • Parcelable is specifically designed for Android and you should use it. Here is a simple example: Passing custom objects between Android activities

You can generate Parcelable code for you class using this site.

Cannot apply indexing with [] to an expression of type 'System.Collections.Generic.IEnumerable<>

you can use indexing if your enumerable type is string like below

((string[])MyEnumerableStringList)[0]

How to add/update an attribute to an HTML element using JavaScript?

What seems easy is actually tricky if you want to be completely compatible.

var e = document.createElement('div');

Let's say you have an id of 'div1' to add.

e['id'] = 'div1';
e.id = 'div1';
e.attributes['id'] = 'div1';
e.createAttribute('id','div1')
These will all work except the last in IE 5.5 (which is ancient history at this point but still is XP's default with no updates).

But there are contingencies, of course. Will not work in IE prior to 8:e.attributes['style'] Will not error but won't actually set the class, it must be className:e['class'] .
However, if you're using attributes then this WILL work:e.attributes['class']

In summary, think of attributes as literal and object-oriented.

In literal, you just want it to spit out x='y' and not think about it. This is what attributes, setAttribute, createAttribute is for (except for IE's style exception). But because these are really objects things can get confused.

Since you are going to the trouble of properly creating a DOM element instead of jQuery innerHTML slop, I would treat it like one and stick with the e.className = 'fooClass' and e.id = 'fooID'. This is a design preference, but in this instance trying to treat is as anything other than an object works against you.

It will never backfire on you like the other methods might, just be aware of class being className and style being an object so it's style.width not style="width:50px". Also remember tagName but this is already set by createElement so you shouldn't need to worry about it.

This was longer than I wanted, but CSS manipulation in JS is tricky business.

How to use the TextWatcher class in Android?

A little bigger perspective of the solution:

@Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        View v = inflater.inflate(R.layout.yourlayout, container, false);
        View tv = v.findViewById(R.id.et1);
        ((TextView) tv).addTextChangedListener(new TextWatcher() {
            @Override
            public void onTextChanged(CharSequence s, int start, int before, int count) {
                 SpannableString contentText = new SpannableString(((TextView) tv).getText());
                 String contents = Html.toHtml(contentText).toString();
            }

            @Override
            public void beforeTextChanged(CharSequence s, int start, int count, int after) {

                // TODO Auto-generated method stub
            }

            @Override
            public void afterTextChanged(Editable s) {

                // TODO Auto-generated method stub
            }
        });
        return v;
    }

This works for me, doing it my first time.

How to change colour of blue highlight on select box dropdown

Just found this whilst looking for a solution. I've only tested it FF 32.0.3

box-shadow: 0 0 10px 100px #fff inset;

How do I delete a Git branch locally and remotely?

According to the latest document using a terminal we can delete in the following way.

Delete in local:

git branch -D usermanagement

Delete in remote location:

git push --delete origin usermanagement

How to specify the default error page in web.xml?

You can also specify <error-page> for exceptions using <exception-type>, eg below:

<error-page>
    <exception-type>java.lang.Exception</exception-type>
    <location>/errorpages/exception.html</location>
</error-page>

Or map a error code using <error-code>:

<error-page>
    <error-code>404</error-code>
    <location>/errorpages/404error.html</location>
</error-page>

Log4j, configuring a Web App to use a relative path

In case you're using Maven I have a great solution for you:

  1. Edit your pom.xml file to include following lines:

    <profiles>
        <profile>
            <id>linux</id>
            <activation>
                <os>
                    <family>unix</family>
                </os>
            </activation>
            <properties>
                <logDirectory>/var/log/tomcat6</logDirectory>
            </properties>
        </profile>
        <profile>
            <id>windows</id>
            <activation>
                <os>
                    <family>windows</family>
                </os>
            </activation>
            <properties>
                <logDirectory>${catalina.home}/logs</logDirectory>
            </properties>
        </profile>
    </profiles>
    

    Here you define logDirectory property specifically to OS family.

  2. Use already defined logDirectory property in log4j.properties file:

    log4j.appender.FILE=org.apache.log4j.RollingFileAppender
    log4j.appender.FILE.File=${logDirectory}/mylog.log
    log4j.appender.FILE.MaxFileSize=30MB
    log4j.appender.FILE.MaxBackupIndex=10
    log4j.appender.FILE.layout=org.apache.log4j.PatternLayout
    log4j.appender.FILE.layout.ConversionPattern=%d{ISO8601} [%x] %-5p [%t] [%c{1}] %m%n
    
  3. That's it!

P.S.: I'm sure this can be achieved using Ant but unfortunately I don't have enough experience with it.

Alternative to deprecated getCellType

Use getCellType()

switch (cell.getCellType()) {
   case BOOLEAN :
                 //To-do
                 break;
   case NUMERIC:
                 //To-do
                 break;
   case STRING:
                 //To-do
                 break;
}

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)

How to list only top level directories in Python?

scanDir = "abc"
directories = [d for d in os.listdir(scanDir) if os.path.isdir(os.path.join(os.path.abspath(scanDir), d))]

Alternate background colors for list items

You can by hardcoding the sequence, like so:

li, li + li + li, li + li + li + li + li {
  background-color: black;
}

li + li, li + li + li + li {
  background-color: white;
}

Reading RFID with Android phones

You can hijack your Android audio port using an Arduino board like this. Then, you have two options (as far as I'm concerned):

1) Buy another Arduino Shield that supports RFID. I haven't seen one that supports UHF so far.

2) Try to connect your Arduino hijack with a USB RFID reader and build some embedded hardware kit.

Right now, I'm working in the second option but with iPhone.

Debugging iframes with Chrome developer tools

In the Developer Tools in Chrome, there is a bar along the top, called the Execution Context Selector (h/t felipe-sabino), just under the Elements, Network, Sources... tabs, that changes depending on the context of the current tab. When in the Console tab there is a dropdown in that bar that allows you to select the frame context in which the Console will operate. Select your frame in this drop down and you will find yourself in the appropriate frame context. :D

Chrome v59 Chrome version 59

Chrome v33 Chrome version 33

Chrome v32 & lower Chrome pre-version 32

How to move up a directory with Terminal in OS X

cd .. will back the directory up by one. If you want to reach a folder in the parent directory, you can do something like cd ../foldername. You can use the ".." trick as many times as you want to back up through multiple parent directories. For example, cd ../../Applications would take you to Macintosh HD/Applications

What is the default boolean value in C#?

The default value is indeed false.

However you can't use a local variable is it's not been assigned first.

You can use the default keyword to verify:

bool foo = default(bool);
if (!foo) { Console.WriteLine("Default is false"); }

What is the Python equivalent of Matlab's tic and toc functions?

I changed @Eli Bendersky's answer a little bit to use the ctor __init__() and dtor __del__() to do the timing, so that it can be used more conveniently without indenting the original code:

class Timer(object):
    def __init__(self, name=None):
        self.name = name
        self.tstart = time.time()

    def __del__(self):
        if self.name:
            print '%s elapsed: %.2fs' % (self.name, time.time() - self.tstart)
        else:
            print 'Elapsed: %.2fs' % (time.time() - self.tstart)

To use, simple put Timer("blahblah") at the beginning of some local scope. Elapsed time will be printed at the end of the scope:

for i in xrange(5):
    timer = Timer("eigh()")
    x = numpy.random.random((4000,4000));
    x = (x+x.T)/2
    numpy.linalg.eigh(x)
    print i+1
timer = None

It prints out:

1
eigh() elapsed: 10.13s
2
eigh() elapsed: 9.74s
3
eigh() elapsed: 10.70s
4
eigh() elapsed: 10.25s
5
eigh() elapsed: 11.28s

remove duplicates from sql union

If you are using T-SQL then it appears from previous posts that UNION removes duplicates. But if you are not, you could use distinct. This doesn't quite feel right to me either but it could get you the result you are looking for

SELECT DISTINCT *
FROM
(
select * from calls
left join users a on calls.assigned_to= a.user_id
where a.dept = 4 
union
select * from calls
left join users r on calls.requestor_id= r.user_id
where r.dept = 4
)a

Simple WPF RadioButton Binding?

I came up with a simple solution.

I have a model.cs class with:

private int _isSuccess;
public int IsSuccess { get { return _isSuccess; } set { _isSuccess = value; } }

I have Window1.xaml.cs file with DataContext set to model.cs. The xaml contains the radiobuttons:

<RadioButton IsChecked="{Binding Path=IsSuccess, Converter={StaticResource radioBoolToIntConverter}, ConverterParameter=1}" Content="one" />
<RadioButton IsChecked="{Binding Path=IsSuccess, Converter={StaticResource radioBoolToIntConverter}, ConverterParameter=2}" Content="two" />
<RadioButton IsChecked="{Binding Path=IsSuccess, Converter={StaticResource radioBoolToIntConverter}, ConverterParameter=3}" Content="three" />

Here is my converter:

public class RadioBoolToIntConverter : IValueConverter
{
    public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
    {
        int integer = (int)value;
        if (integer==int.Parse(parameter.ToString()))
            return true;
        else
            return false;
    }

    public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
    {
        return parameter;
    }
}

And of course, in Window1's resources:

<Window.Resources>
    <local:RadioBoolToIntConverter x:Key="radioBoolToIntConverter" />
</Window.Resources>

Read file from resources folder in Spring Boot

i think the problem lies within the space in the folder-name where your project is placed. /home/user/Dev/Java/Java%20Programs/SystemRoutines/target/classes/jsonschema.json

there is space between Java Programs.Renaming the folder name should make it work

How to get Python requests to trust a self signed SSL certificate?

Setting export SSL_CERT_FILE=/path/file.crt should do the job.

Telnet is not recognized as internal or external command

You have to go to Control Panel>Programs>Turn Windows features on or off. Then, check "Telnet Client" and save the changes. You might have to wait about a few minutes before the change could take effect.

How to make the python interpreter correctly handle non-ASCII characters in string operations?

The following code will replace all non ASCII characters with question marks.

"".join([x if ord(x) < 128 else '?' for x in s])

How to find path of active app.config file?

Try this

AppDomain.CurrentDomain.SetupInformation.ConfigurationFile

How to highlight a selected row in ngRepeat?

Each row has an ID. All you have to do is to send this ID to the function setSelected(), store it (in $scope.idSelectedVote for instance), and then check for each row if the selected ID is the same as the current one. Here is a solution (see the documentation for ngClass, if needed):

$scope.idSelectedVote = null;
$scope.setSelected = function (idSelectedVote) {
   $scope.idSelectedVote = idSelectedVote;
};
<ul ng-repeat="vote in votes" ng-click="setSelected(vote.id)" ng-class="{selected: vote.id === idSelectedVote}">
    ...
</ul>

Plunker

A JSONObject text must begin with '{' at 1 [character 2 line 1] with '{' error

in my case my arraylist trhows me that error with the JSONObject , but i fin this solution for my array of String objects

List<String> listStrings= new ArrayList<String>();
String json = new Gson().toJson(listStrings);
return json;

Works like charm with angular Gson version 2.8.5

Types in Objective-C on iOS

Note that you can also use the C99 fixed-width types perfectly well in Objective-C:

#import <stdint.h>
...
int32_t x; // guaranteed to be 32 bits on any platform

The wikipedia page has a decent description of what's available in this header if you don't have a copy of the C standard (you should, though, since Objective-C is just a tiny extension of C). You may also find the headers limits.h and inttypes.h to be useful.

Extract a page from a pdf as a jpeg

Here is a solution which requires no additional libraries and is very fast. This was found from: https://nedbatchelder.com/blog/200712/extracting_jpgs_from_pdfs.html# I have added the code in a function to make it more convenient.

def convert(filepath):
    with open(filepath, "rb") as file:
        pdf = file.read()

    startmark = b"\xff\xd8"
    startfix = 0
    endmark = b"\xff\xd9"
    endfix = 2
    i = 0

    njpg = 0
    while True:
        istream = pdf.find(b"stream", i)
        if istream < 0:
            break
        istart = pdf.find(startmark, istream, istream + 20)
        if istart < 0:
            i = istream + 20
            continue
        iend = pdf.find(b"endstream", istart)
        if iend < 0:
            raise Exception("Didn't find end of stream!")
        iend = pdf.find(endmark, iend - 20)
        if iend < 0:
            raise Exception("Didn't find end of JPG!")

        istart += startfix
        iend += endfix
        jpg = pdf[istart:iend]
        newfile = "{}jpg".format(filepath[:-3])
        with open(newfile, "wb") as jpgfile:
            jpgfile.write(jpg)

        njpg += 1
        i = iend

        return newfile

Call convert with the pdf path as the argument and the function will create a .jpg file in the same directory

Difference between Python's Generators and Iterators

It's difficult to answer the question without 2 other concepts: iterable and iterator protocol.

  1. What is difference between iterator and iterable? Conceptually you iterate over iterable with the help of corresponding iterator. There are a few differences that can help to distinguish iterator and iterable in practice:
    • One difference is that iterator has __next__ method, iterable does not.
    • Another difference - both of them contain __iter__ method. In case of iterable it returns the corresponding iterator. In case of iterator it returns itself. This can help to distinguish iterator and iterable in practice.
>>> x = [1, 2, 3]
>>> dir(x) 
[... __iter__ ...]
>>> x_iter = iter(x)
>>> dir(x_iter)
[... __iter__ ... __next__ ...]
>>> type(x_iter)
list_iterator
  1. What are iterables in python? list, string, range etc. What are iterators? enumerate, zip, reversed etc. We may check this using the approach above. It's kind of confusing. Probably it would be easier if we have only one type. Is there any difference between range and zip? One of the reasons to do this - range has a lot of additional functionality - we may index it or check if it contains some number etc. (see details here).

  2. How can we create an iterator ourselves? Theoretically we may implement Iterator Protocol (see here). We need to write __next__ and __iter__ methods and raise StopIteration exception and so on (see Alex Martelli's answer for an example and possible motivation, see also here). But in practice we use generators. It seems to be by far the main method to create iterators in python.

I can give you a few more interesting examples that show somewhat confusing usage of those concepts in practice:

  • in keras we have tf.keras.preprocessing.image.ImageDataGenerator; this class doesn't have __next__ and __iter__ methods; so it's not an iterator (or generator);
  • if you call its flow_from_dataframe() method you'll get DataFrameIterator that has those methods; but it doesn't implement StopIteration (which is not common in build-in iterators in python); in documentation we may read that "A DataFrameIterator yielding tuples of (x, y)" - again confusing usage of terminology;
  • we also have Sequence class in keras and that's custom implementation of a generator functionality (regular generators are not suitable for multithreading) but it doesn't implement __next__ and __iter__, rather it's a wrapper around generators (it uses yield statement);

Use Fieldset Legend with bootstrap

In bootstrap 4 it is much easier to have a border on the fieldset that blends with the legend. You don't need custom css to achieve it, it can be done like this:

<fieldset class="border p-2">
   <legend  class="w-auto">Your Legend</legend>
</fieldset>

which looks like this: bootstrap 4 fieldset and legend

I have never set any passwords to my keystore and alias, so how are they created?

Better than all options, you can set your signingConfig to be equals your debug.signingConfig. To do that you just need to do the following:

android {
  ...
  buildTypes {
    ...
    wantedBuildType {
      signingConfig debug.signingConfig
    }
  }
}

With that you will not need to know where the debug.keystore is, the app will work for all team, even if someone use a different environment.

Converting SVG to PNG using C#

There is a much easier way using the library http://svg.codeplex.com/ (Newer version @GIT, @NuGet). Here is my code

var byteArray = Encoding.ASCII.GetBytes(svgFileContents);
using (var stream = new MemoryStream(byteArray))
{
    var svgDocument = SvgDocument.Open(stream);
    var bitmap = svgDocument.Draw();
    bitmap.Save(path, ImageFormat.Png);
}

How to set border's thickness in percentages?

Percentage values are not applicable to border-width in CSS. This is listed in the spec.

You will need to use JavaScript to calculate the percentage of the element's width or whatever length quantity you need, and apply the result in px or similar to the element's borders.