Programs & Examples On #Fact table

Difference between Fact table and Dimension table?

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

Fact Table:

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

Dimension Tables:

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

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image source

android on Text Change Listener

editText.addTextChangedListener(new TextWatcher() {
            @Override
            public void beforeTextChanged(CharSequence charSequence, int i, int i1, int i2) {

            }
            @Override
            public void onTextChanged(CharSequence charSequence, int i, int i1, int i2) {
                if (noteid != -1) {
                    MainActivity.notes.set(noteid, String.valueOf(charSequence));
                    MainActivity.arrayAdapter.notifyDataSetChanged();
                }
            }
            @Override
            public void afterTextChanged(Editable editable) {

            }
        });

in this code noteid is basically arguments taken back which is being putted into the indent or passed through the indent.

  Intent intent = getIntent();
         noteid = intent.getIntExtra("noteid", -1);

the code on the downside is basically the extra code ,if you want to understand more clearly.

how to make the menu or insert the menu in our code , 
    create the  menu folder this the folder created by going into the raw
    ->rightclick->
    directory->name the folder as you wish->
    then click on the directory formed->
    then click on new file and then name for file as you wish ie the folder name file
    and now type the 2 lines code in it and see the magic.

new activity code named as NoteEditor.java for editing purpose,my app is basicley the note app.

package com.example.elavi.notes;
import android.content.Intent;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.text.Editable;
import android.text.TextWatcher;
import android.widget.EditText;
import android.widget.Toast;

import static android.media.CamcorderProfile.get;
public class NoteEditorActivity extends AppCompatActivity {
    EditText editText;
    int noteid;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_note_editor);
        editText = findViewById(R.id.editText);
        Intent intent = getIntent();
         noteid = intent.getIntExtra("noteid", -1);
        if (noteid != -1) {
            String text = MainActivity.notes.get(noteid);
            editText.setText(text);

           Toast.makeText(getApplicationContext(),"The arraylist content is"+MainActivity.notes.get(noteid),Toast.LENGTH_SHORT).show();
        }
        else
        {
            Toast.makeText(getApplicationContext(),"Here we go",Toast.LENGTH_SHORT).show();
            MainActivity.notes.add("");
            noteid=MainActivity.notes.size()-1;
        }
        editText.addTextChangedListener(new TextWatcher() {
            @Override
            public void beforeTextChanged(CharSequence charSequence, int i, int i1, int i2) {

            }
            @Override
            public void onTextChanged(CharSequence charSequence, int i, int i1, int i2) {
                if (noteid != -1) {
                    MainActivity.notes.set(noteid, String.valueOf(charSequence));
                    MainActivity.arrayAdapter.notifyDataSetChanged();
                }
            }
            @Override
            public void afterTextChanged(Editable editable) {

            }
        });
    }
}

How can I exclude directories from grep -R?

You could try something like grep -R search . | grep -v '^node_modules/.*'

How to create and handle composite primary key in JPA

The MyKey class (@Embeddable) should not have any relationships like @ManyToOne

How to keep footer at bottom of screen

Perhaps the easiest is to use position: absolute to fix to the bottom, then a suitable margin/padding to make sure that the other text doesn't spill over the top of it.

css:

<style>
  body {
    margin: 0 0 20px;
  }
  .footer {
    position: absolute;
    bottom: 0;
    height: 20px;
    background: #f0f0f0;
    width: 100%;
  }
</style>

Here is the html main content.

<div class="footer"> Here is the footer. </div>

Python in Xcode 4+?

Try Editra It's free, has a lot of cool features and plug-ins, it runs on most platforms, and it is written in Python. I use it for all my non-XCode development at home and on Windows/Linux at work.

Is it possible to print a variable's type in standard C++?

In C++11, we have decltype. There is no way in standard c++ to display exact type of variable declared using decltype. We can use boost typeindex i.e type_id_with_cvr (cvr stands for const, volatile, reference) to print type like below.

#include <iostream>
#include <boost/type_index.hpp>

using namespace std;
using boost::typeindex::type_id_with_cvr;

int main() {
  int i = 0;
  const int ci = 0;
  cout << "decltype(i) is " << type_id_with_cvr<decltype(i)>().pretty_name() << '\n';
  cout << "decltype((i)) is " << type_id_with_cvr<decltype((i))>().pretty_name() << '\n';
  cout << "decltype(ci) is " << type_id_with_cvr<decltype(ci)>().pretty_name() << '\n';
  cout << "decltype((ci)) is " << type_id_with_cvr<decltype((ci))>().pretty_name() << '\n';
  cout << "decltype(std::move(i)) is " << type_id_with_cvr<decltype(std::move(i))>().pretty_name() << '\n';
  cout << "decltype(std::static_cast<int&&>(i)) is " << type_id_with_cvr<decltype(static_cast<int&&>(i))>().pretty_name() << '\n';
  return 0;
}

Create an Excel file using vbscripts

'Create Excel

Set objExcel = Wscript.CreateObject("Excel.Application")

objExcel.visible = True

Set objWb = objExcel.Workbooks.Add

objWb.Saveas("D:\Example.xlsx")

objExcel.Quit

Loop through all the rows of a temp table and call a stored procedure for each row

You can do something like this

    Declare @min int=0, @max int =0 --Initialize variable here which will be use in loop 
    Declare @Recordid int,@TO nvarchar(30),@Subject nvarchar(250),@Body nvarchar(max)  --Initialize variable here which are useful for your

    select ROW_NUMBER() OVER(ORDER BY [Recordid] )  AS Rownumber, Recordid, [To], [Subject], [Body], [Flag]
            into #temp_Mail_Mstr FROM Mail_Mstr where Flag='1'  --select your condition with row number & get into a temp table

    set @min = (select MIN(Rownumber) from #temp_Mail_Mstr); --Get minimum row number from temp table
    set @max = (select Max(Rownumber) from #temp_Mail_Mstr);  --Get maximum row number from temp table

   while(@min <= @max)
   BEGIN
        select @Recordid=Recordid, @To=[To], @Subject=[Subject], @Body=Body from #temp_Mail_Mstr where Rownumber=@min

        -- You can use your variables (like @Recordid,@To,@Subject,@Body) here  
        -- Do your work here 

        set @min=@min+1 --Increment of current row number
    END

How to find what code is run by a button or element in Chrome using Developer Tools

Alexander Pavlov's answer gets the closest to what you want.

Due to the extensiveness of jQuery's abstraction and functionality, a lot of hoops have to be jumped in order to get to the meat of the event. I have set up this jsFiddle to demonstrate the work.


1. Setting up the Event Listener Breakpoint

You were close on this one.

  1. Open the Chrome Dev Tools (F12), and go to the Sources tab.
  2. Drill down to Mouse -> Click
    Chrome Dev Tools -> Sources tab -> Mouse -> Click
    (click to zoom)

2. Click the button!

Chrome Dev Tools will pause script execution, and present you with this beautiful entanglement of minified code:

Chrome Dev Tools paused script execution (click to zoom)


3. Find the glorious code!

Now, the trick here is to not get carried away pressing the key, and keep an eye out on the screen.

  1. Press the F11 key (Step In) until desired source code appears
  2. Source code finally reached
    • In the jsFiddle sample provided above, I had to press F11 108 times before reaching the desired event handler/function
    • Your mileage may vary, depending on the version of jQuery (or framework library) used to bind the events
    • With enough dedication and time, you can find any event handler/function

Desired event handler/function


4. Explanation

I don't have the exact answer, or explanation as to why jQuery goes through the many layers of abstractions it does - all I can suggest is that it is because of the job it does to abstract away its usage from the browser executing the code.

Here is a jsFiddle with a debug version of jQuery (i.e., not minified). When you look at the code on the first (non-minified) breakpoint, you can see that the code is handling many things:

    // ...snip...

    if ( !(eventHandle = elemData.handle) ) {
        eventHandle = elemData.handle = function( e ) {
            // Discard the second event of a jQuery.event.trigger() and
            // when an event is called after a page has unloaded
            return typeof jQuery !== strundefined && jQuery.event.triggered !== e.type ?
                jQuery.event.dispatch.apply( elem, arguments ) : undefined;
        };
    }

    // ...snip...

The reason I think you missed it on your attempt when the "execution pauses and I jump line by line", is because you may have used the "Step Over" function, instead of Step In. Here is a StackOverflow answer explaining the differences.

Finally, the reason why your function is not directly bound to the click event handler is because jQuery returns a function that gets bound. jQuery's function in turn goes through some abstraction layers and checks, and somewhere in there, it executes your function.

Adding and removing extensionattribute to AD object

Set-ADUser -Identity anyUser -Replace @{extensionAttribute4="myString"}

This is also usefull

JAVA_HOME should point to a JDK not a JRE

Make sure that you do NOT have a JRE path, if you have delete it.

  1. Add JAVA_HOME in the System variable. Variable value: C:\Program Files\Java\jdk-10.0.2 (location of JDK without bin)
  2. Add M2 in the System variable. Variable value: C:\dev\maven\apache-maven-3.5.4\bin (location of maven with bin)
  3. Add M2_HOME in the System variable. Variable value: C:\dev\maven\apache-maven-3.5.4 (location of maven without bin)
  4. Add %JAVA_HOME% and %M2% in Path System Variable or C:\Program Files\Java\jdk-10.0.2 and C:\dev\maven\apache-maven-3.5.4\bin --> For windows 10, just add the location. For other version, at the end of the Variable Value field add semicolon then the location Ex: ;%JAVA_HOME%;%M2%

I did not check if the addition or removal of bin changes the result but nonetheless this works for me.

Escaping backslash in string - javascript

Add an input id to the element and do something like that:

document.getElementById('inputId').value.split(/[\\$]/).pop()

How to find the cumulative sum of numbers in a list?

Try this:

result = []
acc = 0
for i in time_interval:
    acc += i
    result.append(acc)

What's the best way to detect a 'touch screen' device using JavaScript?

There is something better than checking if they have a touchScreen, is to check if they are using it, plus that's easier to check.

if (window.addEventListener) {
    var once = false;
    window.addEventListener('touchstart', function(){
        if (!once) {
            once = true;
            // Do what you need for touch-screens only
        }
    });
}

Failed to load ApplicationContext from Unit Test: FileNotFound

If you are using intellij, then try restarting intellij cache

  1. File-> Invalidate cache/restart
  2. clean and build project

See if it works, it worked for me.

Add URL link in CSS Background Image?

Using only CSS it is not possible at all to add links :) It is not possible to link a background-image, nor a part of it, using HTML/CSS. However, it can be staged using this method:

<div class="wrapWithBackgroundImage">
    <a href="#" class="invisibleLink"></a>
</div>

.wrapWithBackgroundImage {
    background-image: url(...);
}
.invisibleLink {
    display: block;
    left: 55px; top: 55px;
    position: absolute;
    height: 55px width: 55px;
}

How to split a string into an array of characters in Python?

To split a string s, the easiest way is to pass it to list(). So,

s = 'abc'
s_l = list(s) #  s_l is now ['a', 'b', 'c']

You can also use a list comprehension, which works but is not as concise as the above:

s_l = [c for c in s]

There are other ways, as well, but these should suffice. Later, if you want to recombine them, a simple call to "".join(s_l) will return your list to all its former glory as a string...

What database does Google use?

It's something they've built themselves - it's called Bigtable.

http://en.wikipedia.org/wiki/BigTable

There is a paper by Google on the database:

http://research.google.com/archive/bigtable.html

Oracle "(+)" Operator

In Oracle, (+) denotes the "optional" table in the JOIN. So in your query,

SELECT a.id, b.id, a.col_2, b.col_2, ...
FROM a,b
WHERE a.id=b.id(+)

it's a LEFT OUTER JOIN of table 'b' to table 'a'. It will return all data of table 'a' without losing its data when the other side (optional table 'b') has no data.

Diagram of Left Outer Join

The modern standard syntax for the same query would be

SELECT  a.id, b.id, a.col_2, b.col_2, ...
FROM a
LEFT JOIN b ON a.id=b.id

or with a shorthand for a.id=b.id (not supported by all databases):

SELECT  a.id, b.id, a.col_2, b.col_2, ...
FROM a
LEFT JOIN b USING(id)

If you remove (+) then it will be normal inner join query

Older syntax, in both Oracle and other databases:

SELECT  a.id, b.id, a.col_2, b.col_2, ...
FROM a,b
WHERE a.id=b.id

More modern syntax:

SELECT  a.id, b.id, a.col_2, b.col_2, ...
FROM a
INNER JOIN b ON a.id=b.id

Or simply:

SELECT  a.id, b.id, a.col_2, b.col_2, ...
FROM a
JOIN b ON a.id=b.id

Diagram of Inner Join

It will only return all data where both 'a' & 'b' tables 'id' value is same, means common part.

If you want to make your query a Right Join

This is just the same as a LEFT JOIN, but switches which table is optional.

Diagram of Right Outer Join

Old Oracle syntax:

SELECT  a.id, b.id, a.col_2, b.col_2, ...
FROM a,b
WHERE a.id(+)=b.id

Modern standard syntax:

SELECT  a.id, b.id, a.col_2, b.col_2, ...
FROM a
RIGHT JOIN b ON a.id=b.id

Ref & help:

https://asktom.oracle.com/pls/asktom/f?p=100:11:::::P11_QUESTION_ID:6585774577187

Left Outer Join using + sign in Oracle 11g

https://www.w3schools.com/sql/sql_join_left.asp

How to calculate age (in years) based on Date of Birth and getDate()

You need to consider the way the datediff command rounds.

SELECT CASE WHEN dateadd(year, datediff (year, DOB, getdate()), DOB) > getdate()
            THEN datediff(year, DOB, getdate()) - 1
            ELSE datediff(year, DOB, getdate())
       END as Age
FROM <table>

Which I adapted from here.

Note that it will consider 28th February as the birthday of a leapling for non-leap years e.g. a person born on 29 Feb 2020 will be considered 1 year old on 28 Feb 2021 instead of 01 Mar 2021.

IP to Location using Javascript

A better way is to skip the "middle man" (ip)

jQuery.get("http://ipinfo.io", function(response) {
    console.log(response.city);
}, "jsonp");

This gives you the IP, the city, the country, etc

Plugin is too old, please update to a more recent version, or set ANDROID_DAILY_OVERRIDE environment variable to

You can always check the latest gradle plugin version here: https://bintray.com/android/android-tools/com.android.tools.build.gradle

So as of today you should use:

classpath 'com.android.tools.build:gradle:2.2.2'

accordingly.

How to validate phone number in laravel 5.2?

You can try out this phone validator package. Laravel Phone

Update

I recently discovered another package Lavarel Phone Validator (stuyam/laravel-phone-validator), that uses the free Twilio phone lookup service

Saving the PuTTY session logging

To set permanent PuTTY session parameters do:

  1. Create sessions in PuTTY. Name it as "MyskinPROD"

  2. Configure the path for this session to point to "C:\dir\&Y&M&D&T_&H_putty.log".

  3. Create a Windows "Shortcut" to C:...\Putty.exe.

  4. Open "Shortcut" Properties and append "Target" line with parameters as shown below:

    "C:\Program Files (x86)\UTL\putty.exe" -ssh -load MyskinPROD user@ServerIP -pw password
    

Now, your PuTTY shortcut will bring in the "MyskinPROD" configuration every time you open the shortcut.

Check the screenshots and details on how I did it in my environment:

http://www.evernote.com/shard/s184/sh/93ebf08f-fde2-4dad-bccf-961c98fb614b/983d2ff8f2d1e6184318825d68b0b829

Array of char* should end at '\0' or "\0"?

Null termination is a bad design pattern best left in the history books. There's still plenty of inertia behind c-strings, so it can't be avoided there. But there's no reason to use it in the OP's example.

Don't use any terminator, and use sizeof(array) / sizeof(array[0]) to get the number of elements.

Fit image to table cell [Pure HTML]

Inline content leaves space at the bottom for characters that descend (j, y, q):

https://developer.mozilla.org/en-US/docs/Images,_Tables,_and_Mysterious_Gaps

There are a couple fixes:

Use display: block;

<img style="display:block;" width="100%" height="100%" src="http://dummyimage.com/68x68/000/fff" />

or use vertical-align: bottom;

<img style="vertical-align: bottom;" width="100%" height="100%" src="http://dummyimage.com/68x68/000/fff" />

How to get current value of RxJS Subject or Observable?

A similar looking answer was downvoted. But I think I can justify what I'm suggesting here for limited cases.


While it's true that an observable doesn't have a current value, very often it will have an immediately available value. For example with redux / flux / akita stores you may request data from a central store, based on a number of observables and that value will generally be immediately available.

If this is the case then when you subscribe, the value will come back immediately.

So let's say you had a call to a service, and on completion you want to get the latest value of something from your store, that potentially might not emit:

You might try to do this (and you should as much as possible keep things 'inside pipes'):

 serviceCallResponse$.pipe(withLatestFrom(store$.select(x => x.customer)))
                     .subscribe(([ serviceCallResponse, customer] => {

                        // we have serviceCallResponse and customer 
                     });

The problem with this is that it will block until the secondary observable emits a value, which potentially could be never.

I found myself recently needing to evaluate an observable only if a value was immediately available, and more importantly I needed to be able to detect if it wasn't. I ended up doing this:

 serviceCallResponse$.pipe()
                     .subscribe(serviceCallResponse => {

                        // immediately try to subscribe to get the 'available' value
                        // note: immediately unsubscribe afterward to 'cancel' if needed
                        let customer = undefined;

                        // whatever the secondary observable is
                        const secondary$ = store$.select(x => x.customer);

                        // subscribe to it, and assign to closure scope
                        sub = secondary$.pipe(take(1)).subscribe(_customer => customer = _customer);
                        sub.unsubscribe();

                        // if there's a delay or customer isn't available the value won't have been set before we get here
                        if (customer === undefined) 
                        {
                           // handle, or ignore as needed
                           return throwError('Customer was not immediately available');
                        }
                     });

Note that for all of the above I'm using subscribe to get the value (as @Ben discusses). Not using a .value property, even if I had a BehaviorSubject.

How to get a product's image in Magento?

You need set image type :small_image or image

echo $this->helper('catalog/image')->init($_product, 'small_image')->resize(163, 100);

Add text to textarea - Jquery

Just append() the text nodes:

$('#replyBox').append(quote); 

http://jsfiddle.net/nQErc/

HTTP Status 500 - org.apache.jasper.JasperException: java.lang.NullPointerException

NullPointerException with JSP can also happen if:

A getter returns a non-public inner class.

This code will fail if you remove Getters's access modifier or make it private or protected.

JAVA:

package com.myPackage;
public class MyClass{ 
    //: Must be public or you will get:
    //: org.apache.jasper.JasperException: 
    //: java.lang.NullPointerException
    public class Getters{
        public String 
        myProperty(){ return(my_property); }
    };;

    //: JSP EL can only access functions:
    private Getters _get;
    public  Getters  get(){ return _get; }

    private String 
    my_property;

    public MyClass(String my_property){
        super();
        this.my_property    = my_property;
        _get = new Getters();
    };;
};;

JSP

<%@ taglib uri   ="http://java.sun.com/jsp/jstl/core" prefix="c" %>
<%@ page import="com.myPackage.MyClass" %>
<%
    MyClass inst = new MyClass("[PROP_VALUE]");
    pageContext.setAttribute("my_inst", inst ); 
%><html lang="en"><body>
    ${ my_inst.get().myProperty() }
</body></html>

Prepend text to beginning of string

Another option would be to use join

var mystr = "Matayoshi";
mystr = ["Mariano", mystr].join(' ');

How to replicate background-attachment fixed on iOS

It has been asked in the past, apparently it costs a lot to mobile browsers, so it's been disabled.

Check this comment by @PaulIrish:

Fixed-backgrounds have huge repaint cost and decimate scrolling performance, which is, I believe, why it was disabled.

you can see workarounds to this in this posts:

Fixed background image with ios7

Fixed body background scrolls with the page on iOS7

How to connect to SQL Server database from JavaScript in the browser?

A perfect working code..

    <script>
    var objConnection = new ActiveXObject("adodb.connection");
    var strConn = "driver={sql server};server=QITBLRQIPL030;database=adventureworks;uid=sa;password=12345";
    objConnection.Open(strConn);
    var rs = new ActiveXObject("ADODB.Recordset");
    var strQuery = "SELECT * FROM  Person.Address";
    rs.Open(strQuery, objConnection);
    rs.MoveFirst();
    while (!rs.EOF) {
        document.write(rs.fields(0) + "&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;");
        document.write(rs.fields(1) + "&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;");
        document.write(rs.fields(2) + "&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;    ");
        document.write(rs.fields(3) + "&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;    ");
        document.write(rs.fields(4) + "<br/>");
        rs.movenext();
    }
</script>

How to copy folders to docker image from Dockerfile?

Like @Vonc said, there is no possibility to add a command like as of now. The only workaround is to mention the folder, to create it and add contents to it.

# add contents to folder
ADD src $HOME/src

Would create a folder called src in your directory and add contents of your folder src into this.

How can I check the size of a file in a Windows batch script?

This was my solution for evaluating file sizes without using VB/perl/etc. and sticking with native windows shell commands:

FOR /F "tokens=4 delims= " %%i in ('dir /-C %temp% ^| find /i "filename.txt"') do (  
    IF %%i GTR 1000000 (  
        echo filename.txt filesize is greater than 1000000  
    ) ELSE (  
        echo filename.txt filesize is less than 1000000  
    )
)  

Not the cleanest solution, but it gets the job done.

Qt Creator color scheme

Linux, Qt Creator >= 3.4:

You could edit theese themes:

/usr/share/qtcreator/themes/default.creatortheme
/usr/share/qtcreator/themes/dark.creatortheme

Sort Dictionary by keys

For Swift 4 the following has worked for me:

let dicNumArray = ["q":[1,2,3,4,5],"a":[2,3,4,5,5],"s":[123,123,132,43,4],"t":[00,88,66,542,321]]

let sortedDic = dicNumArray.sorted { (aDic, bDic) -> Bool in
    return aDic.key < bDic.key
}

How do you stop tracking a remote branch in Git?

The simplest way is to edit .git/config

Here is an example file

[core]
        repositoryformatversion = 0
        filemode = true
        bare = false
        logallrefupdates = true
        ignorecase = true
[remote "origin"]
        url = [email protected]:repo-name
        fetch = +refs/heads/*:refs/remotes/origin/*
[branch "test1"]
        remote = origin
        merge = refs/heads/test1
[branch "master"]
        remote = origin
        merge = refs/heads/master

Delete the line merge = refs/heads/test1 in the test1 branch section

Convert java.time.LocalDate into java.util.Date type

public static Date convertToTimeZone(Date date, String tzFrom, String tzTo) {
    return Date.from(LocalDateTime.ofInstant(date.toInstant(), ZoneId.of(tzTo)).atZone(ZoneId.of(tzFrom)).toInstant());
} 

How can I divide one column of a data frame through another?

There are a plethora of ways in which this can be done. The problem is how to make R aware of the locations of the variables you wish to divide.

Assuming

d <- read.table(text = "263807.0    1582
196190.5    1016
586689.0    3479
")
names(d) <- c("min", "count2.freq")
> d
       min count2.freq
1 263807.0        1582
2 196190.5        1016
3 586689.0        3479

My preferred way

To add the desired division as a third variable I would use transform()

> d <- transform(d, new = min / count2.freq)
> d
       min count2.freq      new
1 263807.0        1582 166.7554
2 196190.5        1016 193.1009
3 586689.0        3479 168.6373

The basic R way

If doing this in a function (i.e. you are programming) then best to avoid the sugar shown above and index. In that case any of these would do what you want

## 1. via `[` and character indexes
d[, "new"] <- d[, "min"] / d[, "count2.freq"]

## 2. via `[` with numeric indices
d[, 3] <- d[, 1] / d[, 2]

## 3. via `$`
d$new <- d$min / d$count2.freq

All of these can be used at the prompt too, but which is easier to read:

d <- transform(d, new = min / count2.freq)

or

d$new <- d$min / d$count2.freq ## or any of the above examples

Hopefully you think like I do and the first version is better ;-)

The reason we don't use the syntactic sugar of tranform() et al when programming is because of how they do their evaluation (look for the named variables). At the top level (at the prompt, working interactively) transform() et al work just fine. But buried in function calls or within a call to one of the apply() family of functions they can and often do break.

Likewise, be careful using numeric indices (## 2. above); if you change the ordering of your data, you will select the wrong variables.

The preferred way if you don't need replacement

If you are just wanting to do the division (rather than insert the result back into the data frame, then use with(), which allows us to isolate the simple expression you wish to evaluate

> with(d, min / count2.freq)
[1] 166.7554 193.1009 168.6373

This is again much cleaner code than the equivalent

> d$min / d$count2.freq
[1] 166.7554 193.1009 168.6373

as it explicitly states that "using d, execute the code min / count2.freq. Your preference may be different to mine, so I have shown all options.

dropping a global temporary table

Step 1. Figure out which errors you want to trap:

If the table does not exist:

SQL> drop table x;
drop table x
           *
ERROR at line 1:
ORA-00942: table or view does not exist

If the table is in use:

SQL> create global temporary table t (data varchar2(4000));

Table created.

Use the table in another session. (Notice no commit or anything after the insert.)

SQL> insert into t values ('whatever');

1 row created.

Back in the first session, attempt to drop:

SQL> drop table t;
drop table t
           *
ERROR at line 1:
ORA-14452: attempt to create, alter or drop an index on temporary table already in use

So the two errors to trap:

  1. ORA-00942: table or view does not exist
  2. ORA-14452: attempt to create, alter or drop an index on temporary table already in use

See if the errors are predefined. They aren't. So they need to be defined like so:

create or replace procedure p as
    table_or_view_not_exist exception;
    pragma exception_init(table_or_view_not_exist, -942);
    attempted_ddl_on_in_use_GTT exception;
    pragma exception_init(attempted_ddl_on_in_use_GTT, -14452);
begin
    execute immediate 'drop table t';

    exception 
        when table_or_view_not_exist then
            dbms_output.put_line('Table t did not exist at time of drop. Continuing....');

        when attempted_ddl_on_in_use_GTT then
            dbms_output.put_line('Help!!!! Someone is keeping from doing my job!');
            dbms_output.put_line('Please rescue me');
            raise;
end p;

And results, first without t:

SQL> drop table t;

Table dropped.

SQL> exec p;
Table t did not exist at time of drop. Continuing....

PL/SQL procedure successfully completed.

And now, with t in use:

SQL> create global temporary table t (data varchar2(4000));

Table created.

In another session:

SQL> insert into t values (null);

1 row created.

And then in the first session:

SQL> exec p;
Help!!!! Someone is keeping from doing my job!
Please rescue me
BEGIN p; END;

*
ERROR at line 1:
ORA-14452: attempt to create, alter or drop an index on temporary table already in use
ORA-06512: at "SCHEMA_NAME.P", line 16
ORA-06512: at line 1

Docker container not starting (docker start)

You are trying to run bash, an interactive shell that requires a tty in order to operate. It doesn't really make sense to run this in "detached" mode with -d, but you can do this by adding -it to the command line, which ensures that the container has a valid tty associated with it and that stdin remains connected:

docker run -it -d -p 52022:22 basickarl/docker-git-test

You would more commonly run some sort of long-lived non-interactive process (like sshd, or a web server, or a database server, or a process manager like systemd or supervisor) when starting detached containers.

If you are trying to run a service like sshd, you cannot simply run service ssh start. This will -- depending on the distribution you're running inside your container -- do one of two things:

  • It will try to contact a process manager like systemd or upstart to start the service. Because there is no service manager running, this will fail.

  • It will actually start sshd, but it will be started in the background. This means that (a) the service sshd start command exits, which means that (b) Docker considers your container to have failed, so it cleans everything up.

If you want to run just ssh in a container, consider an example like this.

If you want to run sshd and other processes inside the container, you will need to investigate some sort of process supervisor.

Alternative to header("Content-type: text/xml");

No. You can't send headers after they were sent. Try to use hooks in wordpress

Get full query string in C# ASP.NET

Just use Request.QueryString.ToString() to get full query string, like this:

string URL = "http://www.example.com/rendernews.php?"+Request.Querystring.ToString();

Drop shadow on a div container?

you might want to try this. Seems to be pretty easy and works on IE6 and Moz atleast.

<div id ="show" style="background-color:Silver;width:100px;height:100px;visibility:visible;border-bottom:outset 1px black;border-right:outset 1px black;" ></div>

The general syntax is : border-[postion]:[border-style] [border-width] [border-color] | inherit

The list of available [border-style]s are :

  • dashed
  • dotted
  • double
  • groove
  • hidden
  • inset
  • none
  • outset
  • ridge
  • solid
  • inherit

org.hibernate.PersistentObjectException: detached entity passed to persist

You didn't provide many relevant details so I will guess that you called getInvoice and then you used result object to set some values and call save with assumption that your object changes will be saved.

However, persist operation is intended for brand new transient objects and it fails if id is already assigned. In your case you probably want to call saveOrUpdate instead of persist.

You can find some discussion and references here "detached entity passed to persist error" with JPA/EJB code

Open source face recognition for Android

Here are some links that I found on face recognition libraries.

Image Identification links:

how to create a login page when username and password is equal in html

Doing password checks on client side is unsafe especially when the password is hard coded.

The safest way is password checking on server side, but even then the password should not be transmitted plain text.

Checking the password client side is possible in a "secure way":

  • The password needs to be hashed
  • The hashed password is used as part of a new url

Say "abc" is your password so your md5 would be "900150983cd24fb0d6963f7d28e17f72" (consider salting!). Now build a url containing the hash (like http://yourdomain.com/90015...f72.html).

Switch between python 2.7 and python 3.5 on Mac OS X

If you want to use Apple’s system install of Python 2.7, be aware that it doesn’t quite follow the naming standards laid out in PEP 394.

In particular, it includes the optional symlinks with suffix 2.7 that you’re told not to rely on, and does not include the recommended symlinks with suffix 2 that you’re told you should rely on.


If you want to fix this, while sticking with Apple’s Python, you can create your own symlinks:

$ cd <somewhere writable and in your PATH>
$ ln -s /usr/bin/python python2

Or aliases in your bash config:

alias python2 python2.7

And you can do likewise for Apple’s 2to3, easy_install, etc. if you need them.

You shouldn’t try to put these symlinks into /usr/bin, and definitely don’t try to rename what’s already there, or to change the distutils setup to something more PEP-compliant. Those files are all part of the OS, and can be used by other parts of the OS, and your changes can be overwritten on even a minor update from 10.13.5 to 10.13.6 or something, so leave them alone and work around them as described above.


Alternatively, you could:

  • Just use python2.7 instead of python2 on the command line and in your shbangs and so on.
  • Use virtual environments or conda environments. The global python, python3, python2, etc. don’t matter when you’re always using the activated environment’s local python.
  • Stop using Apple’s 2.7 and instead install a whole other 2.7 alongside it, as most of the other answers suggest. (I don’t know why so many of them are also suggesting that you install a second 3.6. That’s just going to add even more confusion, for no benefit.)

how to set textbox value in jquery

I would like to point out to you that .val() also works with selects to select the current selected value.

Python Brute Force algorithm

I found another very easy way to create dictionaries using itertools.

generator=itertools.combinations_with_replacement('abcd', 4 )

This will iterate through all combinations of 'a','b','c' and 'd' and create combinations with a total length of 1 to 4. ie. a,b,c,d,aa,ab.........,dddc,dddd. generator is an itertool object and you can loop through normally like this,

for password in generator:
        ''.join(password)

Each password is infact of type tuple and you can work on them as you normally do.

CSS '>' selector; what is it?

It declares parent reference, look at this page for definition:

http://www.w3.org/TR/CSS2/selector.html#child-selectors

Does VBScript have a substring() function?

Yes, Mid.

Dim sub_str
sub_str = Mid(source_str, 10, 5)

The first parameter is the source string, the second is the start index, and the third is the length.

@bobobobo: Note that VBScript strings are 1-based, not 0-based. Passing 0 as an argument to Mid results in "invalid procedure call or argument Mid".

How to get the focused element with jQuery?

$(':focus')[0] will give you the actual element.

$(':focus') will give you an array of elements, usually only one element is focused at a time so this is only better if you somehow have multiple elements focused.

PUT vs. POST in REST

So, which one should be used to create a resource? Or one needs to support both?

You should use PATCH. You PATCH the list of questions like

PATCH /questions HTTP/1.1

with a list containing your to be created object like

[
    {
        "title": "I said semantics!",
        "content": "Is this serious?",
        "answer": "Not really"
    }
]

It's a PATCH request as

  • you modify the existing list of resources without providing the whole new content
  • you change the state of your new question from non-existing to existing without providing all the data (the server will most probably add an id).

A great advantage of this method is that you can create multiple entities using a single request, simply by providing them all in the list.

This is something PUT obviously can't. You could use POST for creating multiple entities as it's the kitchen sink of HTTP and can do basically everything.

A disadvantage is that probably nobody uses PATCH this way. I'm afraid, I just invented it, but I hope, I provided a good argumentation.

You could use CREATE instead, as custom HTTP verbs are allowed, it's just that they mayn't work with some tools.

Concerning semantics, CREATE is IMHO the only right choice, everything else is a square peg in a round hole. Unfortunately, all we have are round holes.

Auto Scale TextView Text to Fit within Bounds

I needed a specific solution. I have got an edittext and textview in my layout. The textview is fixed height and width. When the user starts to type in the edittext, the text should immediately appear in the textview. The text in the textfield should auto - resize to fit the textview. So I updated Chase's solution to work for me. So when the text changes in the textview, resizing starts. The difference between mine and Chase's soluton: resizing is done even if the user DELETE some chars. I hope it can help someone.

public class TextFitTextView extends TextView {

// Minimum text size for this text view
public static final float MIN_TEXT_SIZE = 10;

// Maximum text size for this text view - if it is 0, then the text acts
// like match_parent
public static final float MAX_TEXT_SIZE = 0;

// Our ellipse string
private static final String mEllipsis = "...";

// Text size that is set from code. This acts as a starting point for
// resizing
private float mTextSize;

// Lower bounds for text size
private float mMinTextSize = MIN_TEXT_SIZE;

// Max bounds for text size
private float mMaxTextSize = MAX_TEXT_SIZE;

// Text view line spacing multiplier
private float mSpacingMult = 1.0f;

// Text view additional line spacing
private float mSpacingAdd = 0.0f;

// Add ellipsis to text that overflows at the smallest text size
private boolean mAddEllipsis = true;

// Add ellipsis to text that overflows at the smallest text size
private int heightLimit;
private int widthLimit;

// Default constructor override
public TextFitTextView(Context context) {
    this(context, null);
}

// Default constructor when inflating from XML file
public TextFitTextView(Context context, AttributeSet attrs) {
    this(context, attrs, 0);
}

// Default constructor override
public TextFitTextView(Context context, AttributeSet attrs, int defStyle) {
    super(context, attrs, defStyle);
    mTextSize = getTextSize();
}

/**
 * When text changes resize the text size.
 */
@Override
protected void onTextChanged(final CharSequence text, final int start, final int before, final int after) {
    // if we are adding new chars to text
    if (before <= after && after != 1) {
        resizeText(true);
        // now we are deleting chars
    } else {
        resizeText(false);
    }
}

/**
 * Override the set text size to update our internal reference values
 */
@Override
public void setTextSize(float size) {
    super.setTextSize(size);
    mTextSize = getTextSize();
}

/**
 * Override the set text size to update our internal reference values
 */
@Override
public void setTextSize(int unit, float size) {
    super.setTextSize(unit, size);
    mTextSize = getTextSize();
}

/**
 * Override the set line spacing to update our internal reference values
 */
@Override
public void setLineSpacing(float add, float mult) {
    super.setLineSpacing(add, mult);
    mSpacingMult = mult;
    mSpacingAdd = add;
}

/**
 * Set the lower text size limit and invalidate the view
 * 
 * @param minTextSize
 */
public void setMinTextSize(float minTextSize) {
    mMinTextSize = minTextSize;
    requestLayout();
    invalidate();
}

/**
 * Return lower text size limit
 * 
 * @return
 */
public float getMinTextSize() {
    return mMinTextSize;
}

/**
 * Set flag to add ellipsis to text that overflows at the smallest text size
 * 
 * @param addEllipsis
 */
public void setAddEllipsis(boolean addEllipsis) {
    mAddEllipsis = addEllipsis;
}

/**
 * Return flag to add ellipsis to text that overflows at the smallest text
 * size
 * 
 * @return
 */
public boolean getAddEllipsis() {
    return mAddEllipsis;
}

/**
 * Get width and height limits
 */
@Override
protected void onLayout(boolean changed, int left, int top, int right, int bottom) {
    if (widthLimit == 0 && heightLimit == 0) {
        widthLimit = (right - left) - getCompoundPaddingLeft() - getCompoundPaddingRight();
        heightLimit = (bottom - top) - getCompoundPaddingBottom() - getCompoundPaddingTop();
    }
    super.onLayout(changed, left, top, right, bottom);
}

/**
 * Resize the text size with specified width and height
 * 
 * @param width
 * @param height
 */
public void resizeText(boolean increase) {
    CharSequence text = getText();
    // Do not resize if the view does not have dimensions or there is no
    // text
    if (text == null || text.length() == 0 || heightLimit <= 0 || widthLimit <= 0 || mTextSize == 0) {
        return;
    }

    // Get the text view's paint object
    TextPaint textPaint = getPaint();

    // Get the required text height
    int textHeight = getTextHeight(text, textPaint, widthLimit, mTextSize);


    // If the text length is increased 
    // Until we either fit within our text view or we had reached our min
    // text size, incrementally try smaller sizes
    if (increase) {
        while (textHeight > heightLimit && mTextSize > mMinTextSize) {
            mTextSize = Math.max(mTextSize - 2, mMinTextSize);
            textHeight = getTextHeight(text, textPaint, widthLimit, mTextSize);
        }
    } 
//      text length has been decreased
    else {
//          if max test size is set then add it to while condition
        if (mMaxTextSize != 0) {
            while (textHeight < heightLimit && mTextSize <= mMaxTextSize) {
                mTextSize = mTextSize + 2;
                textHeight = getTextHeight(text, textPaint, widthLimit, mTextSize);
            }
        } else {
            while (textHeight < heightLimit) {
                mTextSize = mTextSize + 2;
                textHeight = getTextHeight(text, textPaint, widthLimit, mTextSize);
            }
        }
        mTextSize = textHeight > heightLimit ? mTextSize - 2 : mTextSize;
    }

    // If we had reached our minimum text size and still don't fit, append
    // an ellipsis
    if (mAddEllipsis && mTextSize == mMinTextSize && textHeight > heightLimit) {
        // Draw using a static layout
        TextPaint paint = new TextPaint(textPaint);
        StaticLayout layout = new StaticLayout(text, paint, widthLimit, Alignment.ALIGN_NORMAL, mSpacingMult,
                mSpacingAdd, false);
        // Check that we have a least one line of rendered text
        if (layout.getLineCount() > 0) {
            // Since the line at the specific vertical position would be cut
            // off,
            // we must trim up to the previous line
            int lastLine = layout.getLineForVertical(heightLimit) - 1;
            // If the text would not even fit on a single line, clear it
            if (lastLine < 0) {
                setText("");
            }
            // Otherwise, trim to the previous line and add an ellipsis
            else {
                int start = layout.getLineStart(lastLine);
                int end = layout.getLineEnd(lastLine);
                float lineWidth = layout.getLineWidth(lastLine);
                float ellipseWidth = paint.measureText(mEllipsis);

                // Trim characters off until we have enough room to draw the
                // ellipsis
                while (widthLimit < lineWidth + ellipseWidth) {
                    lineWidth = paint.measureText(text.subSequence(start, --end + 1).toString());
                }
                setText(text.subSequence(0, end) + mEllipsis);
            }
        }
    }

    // Some devices try to auto adjust line spacing, so force default line
    // spacing
    // and invalidate the layout as a side effect
    setTextSize(TypedValue.COMPLEX_UNIT_PX, mTextSize);
    setLineSpacing(mSpacingAdd, mSpacingMult);

}

// Set the text size of the text paint object and use a static layout to
// render text off screen before measuring
private int getTextHeight(CharSequence source, TextPaint originalPaint, int width, float textSize) {
    // Update the text paint object
    TextPaint paint = new TextPaint(originalPaint);
    paint.setTextSize(textSize);
    // Measure using a static layout
    StaticLayout layout = new StaticLayout(source, paint, width, Alignment.ALIGN_NORMAL, mSpacingMult, mSpacingAdd,
            true);
    return layout.getHeight();
}

}

Wait for a process to finish

On a system like OSX you might not have pgrep so you can try this appraoch, when looking for processes by name:

while ps axg | grep process_name$ > /dev/null; do sleep 1; done

The $ symbol at the end of the process name ensures that grep matches only process_name to the end of line in the ps output and not itself.

Initialize empty vector in structure - c++

Like this:

#include <string>
#include <vector>

struct user
{
    std::string username;
    std::vector<unsigned char> userpassword;
};

int main()
{
    user r;   // r.username is "" and r.userpassword is empty
    // ...
}

Making macOS Installer Packages which are Developer ID ready

Here is a build script which creates a signed installer package out of a build root.

#!/bin/bash
# TRIMCheck build script
# Copyright Doug Richardson 2015
# Usage: build.sh
#
# The result is a disk image that contains the TRIMCheck installer.
#

DSTROOT=/tmp/trimcheck.dst
SRCROOT=/tmp/trimcheck.src

INSTALLER_PATH=/tmp/trimcheck
INSTALLER_PKG="TRIMCheck.pkg"
INSTALLER="$INSTALLER_PATH/$INSTALLER_PKG"

#
# Clean out anything that doesn't belong.
#
echo Going to clean out build directories
rm -rf build $DSTROOT $SRCROOT $INSTALLER_PATH
echo Build directories cleaned out


#
# Build
#
echo ------------------
echo Installing Sources
echo ------------------
xcodebuild -project TRIMCheck.xcodeproj installsrc SRCROOT=$SRCROOT || exit 1

echo ----------------
echo Building Project
echo ----------------
pushd $SRCROOT
xcodebuild -project TRIMCheck.xcodeproj -target trimcheck -configuration Release install || exit 1
popd

echo ------------------
echo Building Installer
echo ------------------
mkdir -p "$INSTALLER_PATH" || exit 1

echo "Runing pkgbuild. Note you must be connected to Internet for this to work as it"
echo "has to contact a time server in order to generate a trusted timestamp. See"
echo "man pkgbuild for more info under SIGNED PACKAGES."
pkgbuild --identifier "com.delicioussafari.TRIMCheck" \
    --sign "Developer ID Installer: Douglas Richardson (4L84QT8KA9)" \
    --root "$DSTROOT" \
    "$INSTALLER" || exit 1


echo Successfully built TRIMCheck
open "$INSTALLER_PATH"

exit 0

How do I change the default index page in Apache?

You can also set DirectoryIndex in apache's httpd.conf file.

CentOS keeps this file in /etc/httpd/conf/httpd.conf Debian: /etc/apache2/apache2.conf

Open the file in your text editor and find the line starting with DirectoryIndex

To load landing.html as a default (but index.html if that's not found) change this line to read:

DirectoryIndex  landing.html index.html

Print content of JavaScript object?

I faced similar problem, The reason for it was i make use of ajax to fetch data. In this case i had made two asynchronous ajax call. In one i just return string msg and show in alert. In second ajax call i fetch arraylist in json format and decode it in js. So my second request use to process first and i was getting alert of object.

So just check. 1. alert should contain string. 2. If u get arrayList or any other Object decode it.

All the best!

Bootstrap 3: Scroll bars

You need to use the overflow option, but with the following parameters:

.nav {
    max-height:300px;
    overflow-y:auto;  
}

Use overflow-y:auto; so the scrollbar only appears when the content exceeds the maximum height.

If you use overflow-y:scroll, the scrollbar will always be visible - on all .nav - regardless if the content exceeds the maximum heigh or not.

Presumably you want something that adapts itself to the content rather then the the opposite.

Hope it may helpful

How to return a specific status code and no contents from Controller?

The best way to do it is:

return this.StatusCode(StatusCodes.Status418ImATeapot, "Error message");

'StatusCodes' has every kind of return status and you can see all of them in this link https://httpstatuses.com/

Once you choose your StatusCode, return it with a message.

Change line width of lines in matplotlib pyplot legend

@ImportanceOfBeingErnest 's answer is good if you only want to change the linewidth inside the legend box. But I think it is a bit more complex since you have to copy the handles before changing legend linewidth. Besides, it can not change the legend label fontsize. The following two methods can not only change the linewidth but also the legend label text font size in a more concise way.

Method 1

import numpy as np
import matplotlib.pyplot as plt

# make some data
x = np.linspace(0, 2*np.pi)

y1 = np.sin(x)
y2 = np.cos(x)

# plot sin(x) and cos(x)
fig = plt.figure()
ax  = fig.add_subplot(111)
ax.plot(x, y1, c='b', label='y1')
ax.plot(x, y2, c='r', label='y2')

leg = plt.legend()
# get the individual lines inside legend and set line width
for line in leg.get_lines():
    line.set_linewidth(4)
# get label texts inside legend and set font size
for text in leg.get_texts():
    text.set_fontsize('x-large')

plt.savefig('leg_example')
plt.show()

Method 2

import numpy as np
import matplotlib.pyplot as plt

# make some data
x = np.linspace(0, 2*np.pi)

y1 = np.sin(x)
y2 = np.cos(x)

# plot sin(x) and cos(x)
fig = plt.figure()
ax  = fig.add_subplot(111)
ax.plot(x, y1, c='b', label='y1')
ax.plot(x, y2, c='r', label='y2')

leg = plt.legend()
# get the lines and texts inside legend box
leg_lines = leg.get_lines()
leg_texts = leg.get_texts()
# bulk-set the properties of all lines and texts
plt.setp(leg_lines, linewidth=4)
plt.setp(leg_texts, fontsize='x-large')
plt.savefig('leg_example')
plt.show()

The above two methods produce the same output image:

output image

Call-time pass-by-reference has been removed

Only call time pass-by-reference is removed. So change:

call_user_func($func, &$this, &$client ...

To this:

call_user_func($func, $this, $client ...

&$this should never be needed after PHP4 anyway period.

If you absolutely need $client to be passed by reference, update the function ($func) signature instead (function func(&$client) {)

How to replace <span style="font-weight: bold;">foo</span> by <strong>foo</strong> using PHP and regex?

$text='<span style="font-weight: bold;">Foo</span>';
$text=preg_replace( '/<span style="font-weight: bold;">(.*?)<\/span>/', '<strong>$1</strong>',$text);

Note: only work for your example.

How do I install a Python package with a .whl file?

I just used the following which was quite simple. First open a console then cd to where you've downloaded your file like some-package.whl and use

pip install some-package.whl

Note: if pip.exe is not recognized, you may find it in the "Scripts" directory from where python has been installed. If pip is not installed, this page can help: How do I install pip on Windows?

Note: for clarification
If you copy the *.whl file to your local drive (ex. C:\some-dir\some-file.whl) use the following command line parameters --

pip install C:/some-dir/some-file.whl

Splitting string into multiple rows in Oracle

I had the same problem, and xmltable helped me:

SELECT id, trim(COLUMN_VALUE) text FROM t, xmltable(('"' || REPLACE(text, ',', '","') || '"'))

Prevent Bootstrap Modal from disappearing when clicking outside or pressing escape?

<button class="btn btn-primary btn-lg" data-backdrop="static" data-keyboard="false" data-target="#myModal" data-toggle="modal">

Meaning of - <?xml version="1.0" encoding="utf-8"?>

This is the XML optional preamble.

  • version="1.0" means that this is the XML standard this file conforms to
  • encoding="utf-8" means that the file is encoded using the UTF-8 Unicode encoding

Location of Django logs and errors

Add to your settings.py:

LOGGING = {
    'version': 1,
    'disable_existing_loggers': False,
    'handlers': {
        'file': {
            'level': 'DEBUG',
            'class': 'logging.FileHandler',
            'filename': 'debug.log',
        },
    },
    'loggers': {
        'django': {
            'handlers': ['file'],
            'level': 'DEBUG',
            'propagate': True,
        },
    },
}

And it will create a file called debug.log in the root of your. https://docs.djangoproject.com/en/1.10/topics/logging/

Ruby function to remove all white spaces?

You can try this:

"ab c d efg hi ".split.map(&:strip)

in order to get this:

["ab, "c", "d", "efg", "hi"]

or if you want a single string, just use:

"ab c d efg hi ".split.join

How to mount a single file in a volume

I had the same issue, docker-compose was creating a directory instead of a file, then crashing mid-way.

what i did :

  1. run the container without mapping the file

  2. copy the config file to the host location :

    docker cp containername:/var/www/html/config.php ./config.php

  3. remove the container (docker-compose down)

  4. put the mapping back and remount up the container

docker compose will find the config file, and will map that instead of trying to create a directory.

How to get the difference between two dictionaries in Python?

You were right to look at using a set, we just need to dig in a little deeper to get your method to work.

First, the example code:

test_1 = {"foo": "bar", "FOO": "BAR"}
test_2 = {"foo": "bar", "f00": "b@r"}

We can see right now that both dictionaries contain a similar key/value pair:

{"foo": "bar", ...}

Each dictionary also contains a completely different key value pair. But how do we detect the difference? Dictionaries don't support that. Instead, you'll want to use a set.

Here is how to turn each dictionary into a set we can use:

set_1 = set(test_1.items())
set_2 = set(test_2.items())

This returns a set containing a series of tuples. Each tuple represents one key/value pair from your dictionary.

Now, to find the difference between set_1 and set_2:

print set_1 - set_2
>>> {('FOO', 'BAR')}

Want a dictionary back? Easy, just:

dict(set_1 - set_2)
>>> {'FOO': 'BAR'}

Round up value to nearest whole number in SQL UPDATE

You could use the ceiling function; this portion of SQL code :

select ceiling(45.01), ceiling(45.49), ceiling(45.99);

will get you "46" each time.

For your update, so, I'd say :

Update product SET price = ceiling(45.01)

BTW : On MySQL, ceil is an alias to ceiling ; not sure about other DB systems, so you might have to use one or the other, depending on the DB you are using...

Quoting the documentation :

CEILING(X)

Returns the smallest integer value not less than X.

And the given example :

mysql> SELECT CEILING(1.23);
        -> 2
mysql> SELECT CEILING(-1.23);
        -> -1

How to check the value given is a positive or negative integer?

1 Checking for positive value

In javascript simple comparison like: value >== 0 does not provide us with answer due to existence of -0 and +0 (This is concept has it roots in derivative equations) Bellow example of those values and its properties:

var negativeZero = -0;
var negativeZero = -1 / Number.POSITIVE_INFINITY;
var negativeZero = -Number.MIN_VALUE / Number.POSITIVE_INFINITY;

var positiveZero = 0;
var positiveZero = 1 / Number.POSITIVE_INFINITY;
var positiveZero = Number.MIN_VALUE / Number.POSITIVE_INFINITY;

-0 === +0                     // true
1 / -0                        // -Infinity
+0 / -0                       // NaN
-0 * Number.POSITIVE_INFINITY // NaN

Having that in mind we can write function like bellow to check for sign of given number:

function isPositive (number) {
    if ( number > 0 ) { 
        return true;
    }
    if (number < 0) {
        return false;
    }
    if ( 1 / number === Number.POSITIVE_INFINITY ) {
        return true;
    }
    return false;
}

2a Checking for number being an Integer (in mathematical sense)

To check that number is an integer we can use bellow function:

function isInteger (number) {
    return parseInt(number) === number;
}
//* in ECMA Script 6 use Number.isInteger

2b Checking for number being an Integer (in computer science)

In this case we are checking that number does not have any exponential part (please note that in JS numbers are represented in double-precision floating-point format) However in javascript it is more usable to check that value is "safe integer" (http://people.mozilla.org/~jorendorff/es6-draft.html#sec-number.max_safe_integer) - to put it simple it means that we can add/substract 1 to "safe integer" and be sure that result will be same as expected from math lessons. To illustrate what I mean, result of some unsafe operations bellow:

Number.MAX_SAFE_INTEGER + 1 === Number.MAX_SAFE_INTEGER + 2;          // true
Number.MAX_SAFE_INTEGER * 2 + 1 === Number.MAX_SAFE_INTEGER * 2 + 4;  // true

Ok, so to check that number is safe integer we can use Number.MAX_SAFE_INTEGER / Number.MIN_SAFE_INTEGER and parseInt to ensure that number is integer at all.

function isSafeInteger (number) {
    return parseInt(number) === number
    && number <== Number.MAX_SAFE_INTEGER
    && number >== Number.MIN_SAFE_INTEGER
}
//* in ECMA Script 6 use Number.isSafeInteger

Recursive query in SQL Server

Sample of the Recursive Level:

enter image description here

DECLARE @VALUE_CODE AS VARCHAR(5);

--SET @VALUE_CODE = 'A' -- Specify a level

WITH ViewValue AS
(
    SELECT ValueCode
    , ValueDesc
    , PrecedingValueCode
    FROM ValuesTable
    WHERE PrecedingValueCode IS NULL
    UNION ALL
    SELECT A.ValueCode
    , A.ValueDesc
    , A.PrecedingValueCode 
    FROM ValuesTable A
    INNER JOIN ViewValue V ON
        V.ValueCode = A.PrecedingValueCode
)

SELECT ValueCode, ValueDesc, PrecedingValueCode

FROM ViewValue

--WHERE PrecedingValueCode  = @VALUE_CODE -- Specific level

--WHERE PrecedingValueCode  IS NULL -- Root

Get exception description and stack trace which caused an exception, all as a string

If you would like to get the same information given when an exception isn't handled you can do something like this. Do import traceback and then:

try:
    ...
except Exception as e:
    print(traceback.print_tb(e.__traceback__))

I'm using Python 3.7.

Creating a JSON Array in node js

This one helped me,

res.format({
        json:function(){
                            var responseData    = {};
                            responseData['status'] = 200;
                            responseData['outputPath']  = outputDirectoryPath;
                            responseData['sourcePath']  = url;
                            responseData['message'] = 'Scraping of requested resource initiated.';
                            responseData['logfile'] = logFileName;
                            res.json(JSON.stringify(responseData));
                        }
    });

Shuffling a list of objects

import random

class a:
    foo = "bar"

a1 = a()
a2 = a()
a3 = a()
a4 = a()
b = [a1,a2,a3,a4]

random.shuffle(b)
print(b)

shuffle is in place, so do not print result, which is None, but the list.

How do I specify local .gem files in my Gemfile?

This isn't strictly an answer to your question about installing .gem packages, but you can specify all kinds of locations on a gem-by-gem basis by editing your Gemfile.

Specifying a :path attribute will install the gem from that path on your local machine.

gem "foreman", path: "/Users/pje/my_foreman_fork"

Alternately, specifying a :git attribute will install the gem from a remote git repository.

gem "foreman", git: "git://github.com/pje/foreman.git"

# ...or at a specific SHA-1 ref
gem "foreman", git: "git://github.com/pje/foreman.git", ref: "bf648a070c"

# ...or branch
gem "foreman", git: "git://github.com/pje/foreman.git", branch: "jruby"

# ...or tag
gem "foreman", git: "git://github.com/pje/foreman.git", tag: "v0.45.0"

(As @JHurrah mentioned in his comment.)

Static Block in Java

It's a static initializer. It's executed when the class is loaded (or initialized, to be precise, but you usually don't notice the difference).

It can be thought of as a "class constructor".

Note that there are also instance initializers, which look the same, except that they don't have the static keyword. Those are run in addition to the code in the constructor when a new instance of the object is created.

How to open local files in Swagger-UI

Yet another option is to run swagger using docker, you can use this docker image:

https://hub.docker.com/r/madscientist/swagger-ui/

I made this ghetto little BASH script to kill running containers and rebuild, so basically each time you make a change to your spec and want to see it, just run the script. Make sure to put the name of your application in the APP_NAME variable

#!/bin/bash

# Replace my_app with your application name
APP_NAME="my_app"

# Clean up old containers and images
old_containers=$(docker ps -a | grep $APP_NAME | awk '{ print $1 }')
old_images=$(docker images | grep $APP_NAME | awk '{ print $3 }')

if [[ $old_containers ]];
    then
        echo "Stopping old containers: $old_containers"
        docker stop $old_containers
        echo "Removing old containers: $old_containers"
        docker rm $old_containers
fi

if [[ $old_images ]];
    then
        echo "Removing stale images"
        docker rmi $old_images
fi

# Create new image
echo "Creating new image for $APP_NAME"
docker build . -t $APP_NAME

# Run container
echo "Running container with image $APP_NAME"
docker run -d --name $APP_NAME -p 8888:8888 $APP_NAME
echo "Check out your swaggery goodness here:

http://localhost:8888/swagger-ui/?url=http://localhost:8888/swagger-ui/swagger.yaml"

Button background as transparent

You apply the background color as transparent(light gray) when you click the button.

ButtonName.setOnClickListener()

In the above method you set the background color of the button.

how to change background image of button when clicked/focused?

you can implement in a xml file for this as follows:

<selector xmlns:android="http://schemas.android.com/apk/res/android">
<item android:state_focused="true" android:drawable="@drawable/your_imagename_while_focused"/>
<item android:state_pressed="true" android:drawable="@drawable/your_imagename_while_pressed" />
<item android:drawable="@drawable/image_name_while_notpressed" />  //means normal
</selector>

now save this xml file in drawable folder and name it suppos abc.xml and set it as follows

 Button tiny = (Button)findViewById(R.id.tiny);
 tiny.setBackgroundResource(R.drawable.abc);

Hope it will help you. :)

How do I replace multiple spaces with a single space in C#?

This is a shorter version, which should only be used if you are only doing this once, as it creates a new instance of the Regex class every time it is called.

temp = new Regex(" {2,}").Replace(temp, " "); 

If you are not too acquainted with regular expressions, here's a short explanation:

The {2,} makes the regex search for the character preceding it, and finds substrings between 2 and unlimited times.
The .Replace(temp, " ") replaces all matches in the string temp with a space.

If you want to use this multiple times, here is a better option, as it creates the regex IL at compile time:

Regex singleSpacify = new Regex(" {2,}", RegexOptions.Compiled);
temp = singleSpacify.Replace(temp, " ");

Body set to overflow-y:hidden but page is still scrollable in Chrome

Find out the element which is larger than the body (element which is causing the page to scroll) and just set it's position to fixed. NOTE: I'm not talking to change the position of draggable elements. Draggable elements can be dragged out of body only when there's an element larger than body (mostly in width).

How can I get date and time formats based on Culture Info?

You could take a look at the DateTimeFormat property which contains the culture specific formats.

How to insert new row to database with AUTO_INCREMENT column without specifying column names?

Just add the column names, yes you can use Null instead but is is a very bad idea to not use column names in any insert, ever.

how to implement Pagination in reactJs

   Sample pagination react js working code 
    import React, { Component } from 'react';
    import {
    Pagination,
    PaginationItem,
    PaginationLink
    } from "reactstrap";


    let prev  = 0;
    let next  = 0;
    let last  = 0;
    let first = 0;
    export default class SamplePagination extends Component {
       constructor() {
         super();
         this.state = {
           todos: ['a','b','c','d','e','f','g','h','i','j','k','l','m','n','o','p','q','r','s','T','v','u','w','x','y','z'],
           currentPage: 1,
           todosPerPage: 3,

         };
         this.handleClick = this.handleClick.bind(this);
         this.handleLastClick = this.handleLastClick.bind(this);
         this.handleFirstClick = this.handleFirstClick.bind(this);
       }

       handleClick(event) {
         event.preventDefault();
         this.setState({
           currentPage: Number(event.target.id)
         });
       }

       handleLastClick(event) {
         event.preventDefault();
         this.setState({
           currentPage:last
         });
       }
       handleFirstClick(event) {
         event.preventDefault();
         this.setState({
           currentPage:1
         });
       }
       render() {
         let { todos, currentPage, todosPerPage } = this.state;

         // Logic for displaying current todos
         let indexOfLastTodo = currentPage * todosPerPage;
         let indexOfFirstTodo = indexOfLastTodo - todosPerPage;
         let currentTodos = todos.slice(indexOfFirstTodo, indexOfLastTodo);
          prev  = currentPage > 0 ? (currentPage -1) :0;
          last = Math.ceil(todos.length/todosPerPage);
          next  = (last === currentPage) ?currentPage: currentPage +1;

         // Logic for displaying page numbers
         let pageNumbers = [];
         for (let i = 1; i <=last; i++) {
           pageNumbers.push(i);
         }

          return (
           <div>
             <ul>
              {
                currentTodos.map((todo,index) =>{
                  return <li key={index}>{todo}</li>;
                })
              }
             </ul><ul id="page-numbers">
             <nav>
              <Pagination>
              <PaginationItem>
              { prev === 0 ? <PaginationLink disabled>First</PaginationLink> :
                  <PaginationLink onClick={this.handleFirstClick} id={prev} href={prev}>First</PaginationLink>
              }
              </PaginationItem>
              <PaginationItem>
              { prev === 0 ? <PaginationLink disabled>Prev</PaginationLink> :
                  <PaginationLink onClick={this.handleClick} id={prev} href={prev}>Prev</PaginationLink>
              }
              </PaginationItem>
                 {
                  pageNumbers.map((number,i) =>
                  <Pagination key= {i}>
                  <PaginationItem active = {pageNumbers[currentPage-1] === (number) ? true : false} >
                   <PaginationLink onClick={this.handleClick} href={number} key={number} id={number}>
                   {number}
                   </PaginationLink>
                   </PaginationItem>
                  </Pagination>
                )}

             <PaginationItem>
             {
               currentPage === last ? <PaginationLink disabled>Next</PaginationLink> :
               <PaginationLink onClick={this.handleClick} id={pageNumbers[currentPage]} href={pageNumbers[currentPage]}>Next</PaginationLink>
             }
             </PaginationItem>

             <PaginationItem>
             {
               currentPage === last ? <PaginationLink disabled>Last</PaginationLink> :
               <PaginationLink onClick={this.handleLastClick} id={pageNumbers[currentPage]} href={pageNumbers[currentPage]}>Last</PaginationLink>
             }
             </PaginationItem>
             </Pagination>
              </nav>
             </ul>
           </div>
         );
       }
     }

     ReactDOM.render(
      <SamplePagination />,
      document.getElementById('root')
    );

Summing elements in a list

def sumoflist(l):    
    total = 0    
    for i in l:
        total +=i
    return total

Why is the jquery script not working?

Wrap your script in the ready function. jsFiddle does that automatically for you.

$(function() {
    $('[id^=\"btnRight\"]').click(function (e) {
        $(this).prev('select').find('option:selected').remove().appendTo('#isselect_code');
    });

    $('[id^=\"btnLeft\"]').click(function (e) {
        $(this).next('select').find('option:selected').remove().appendTo('#canselect_code');
    });
});

This is why you should not use third party tools unless you know what they automate/simplify for you.

How to import a class from default package

There is a workaround for your problem. You can use reflection to achieve it.

First, create an interface for your target class Calculatons :

package mypackage;

public interface CalculationsInterface {  
    int Calculate(int contextId);  
    double GetProgress(int contextId);  

}

Next, make your target class implements that interface:

public class Calculations implements mypackage.CalculationsInterface {
    @Override
    native public int Calculate(int contextId);
    @Override
    native public double GetProgress(int contextId);
    static  {
        System.loadLibrary("Calc");
    }
}

Finally, use reflection to create an instance of Calculations class and assign it to a variable of type CalculationsInterface :

Class<?> calcClass = Class.forName("Calculations");
CalculationsInterface api = (CalculationsInterface)calcClass.newInstance();
// Use it 
double res = api.GetProgress(10);

How to delete multiple pandas (python) dataframes from memory to save RAM?

del statement does not delete an instance, it merely deletes a name.

When you do del i, you are deleting just the name i - but the instance is still bound to some other name, so it won't be Garbage-Collected.

If you want to release memory, your dataframes has to be Garbage-Collected, i.e. delete all references to them.

If you created your dateframes dynamically to list, then removing that list will trigger Garbage Collection.

>>> lst = [pd.DataFrame(), pd.DataFrame(), pd.DataFrame()]
>>> del lst     # memory is released

If you created some variables, you have to delete them all.

>>> a, b, c = pd.DataFrame(), pd.DataFrame(), pd.DataFrame()
>>> lst = [a, b, c]
>>> del a, b, c # dfs still in list
>>> del lst     # memory release now

Change a Git remote HEAD to point to something besides master

If you have access to the remote repo from a shell, just go into the .git (or the main dir if its a bare repo) and change the HEAD file to point to the correct head. For example, by default it always contains 'refs: refs/heads/master', but if you need foo to be the HEAD instead, just edit the HEAD file and change the contents to 'refs: refs/heads/foo'.

Changing image size in Markdown

The accepted answer here isn't working with any Markdown editor available in the apps I have used till date like Ghost, Stackedit.io or even in the StackOverflow editor. I found a workaround here in the StackEdit.io issue tracker.

The solution is to directly use HTML syntax, and it works perfectly:

<img src="http://....jpg" width="200" height="200" />

Curl and PHP - how can I pass a json through curl by PUT,POST,GET

set one more property curl_setopt($ch, CURLOPT_SSL_VERIFYPEER , false);

Fixing a systemd service 203/EXEC failure (no such file or directory)

If that is a copy/paste from your script, you've permuted this line:

#!/usr/env/bin bash

There's no #!/usr/env/bin, you meant #!/usr/bin/env.

How do I clone a github project to run locally?

git clone git://github.com/ryanb/railscasts-episodes.git

When do I have to use interfaces instead of abstract classes?

Interface and Abstract Class are the two different ways to achieve Abstraction in OOP Languages.

Interface provides 100% abstraction, i.e all methods are abstract.

Abstract class provides 0 to 100% abstraction, i.e it may have or may not have abstract methods.

We can use Interface when we want all the functionality of a type to be implemented by the client.

We can use Abstract Class when some common functionality can be provided by Abstract Class implementer and client will be given chance to implement what he needs actually.

Difference between object and class in Scala

Object is a class but it already has(is) an instance, so you can not call new ObjectName. On the other hand, Class is just type and it can be an instance by calling new ClassName().

How to find the installed pandas version

Check pandas.__version__:

In [76]: import pandas as pd

In [77]: pd.__version__
Out[77]: '0.12.0-933-g281dc4e'

Pandas also provides a utility function, pd.show_versions(), which reports the version of its dependencies as well:

In [53]: pd.show_versions(as_json=False)

INSTALLED VERSIONS
------------------
commit: None
python: 2.7.6.final.0
python-bits: 64
OS: Linux
OS-release: 3.13.0-45-generic
machine: x86_64
processor: x86_64
byteorder: little
LC_ALL: None
LANG: en_US.UTF-8

pandas: 0.15.2-113-g5531341
nose: 1.3.1
Cython: 0.21.1
numpy: 1.8.2
scipy: 0.14.0.dev-371b4ff
statsmodels: 0.6.0.dev-a738b4f
IPython: 2.0.0-dev
sphinx: 1.2.2
patsy: 0.3.0
dateutil: 1.5
pytz: 2012c
bottleneck: None
tables: 3.1.1
numexpr: 2.2.2
matplotlib: 1.4.2
openpyxl: None
xlrd: 0.9.3
xlwt: 0.7.5
xlsxwriter: None
lxml: 3.3.3
bs4: 4.3.2
html5lib: 0.999
httplib2: 0.8
apiclient: None
rpy2: 2.5.5
sqlalchemy: 0.9.8
pymysql: None
psycopg2: 2.4.5 (dt dec mx pq3 ext)

Display special characters when using print statement

Do you merely want to print the string that way, or do you want that to be the internal representation of the string? If the latter, create it as a raw string by prefixing it with r: r"Hello\tWorld\nHello World".

>>> a = r"Hello\tWorld\nHello World"
>>> a # in the interpreter, this calls repr()
'Hello\\tWorld\\nHello World'
>>> print a
Hello\tWorld\nHello World

Also, \s is not an escape character, except in regular expressions, and then it still has a much different meaning than what you're using it for.

Print PHP Call Stack

If you want a stack trace which looks very similar to how php formats the exception stack trace than use this function I wrote:

function debug_backtrace_string() {
    $stack = '';
    $i = 1;
    $trace = debug_backtrace();
    unset($trace[0]); //Remove call to this function from stack trace
    foreach($trace as $node) {
        $stack .= "#$i ".$node['file'] ."(" .$node['line']."): "; 
        if(isset($node['class'])) {
            $stack .= $node['class'] . "->"; 
        }
        $stack .= $node['function'] . "()" . PHP_EOL;
        $i++;
    }
    return $stack;
} 

This will return a stack trace formatted like this:

#1 C:\Inetpub\sitename.com\modules\sponsors\class.php(306): filePathCombine()
#2 C:\Inetpub\sitename.com\modules\sponsors\class.php(294): Process->_deleteImageFile()
#3 C:\Inetpub\sitename.com\VPanel\modules\sponsors\class.php(70): Process->_deleteImage()
#4 C:\Inetpub\sitename.com\modules\sponsors\process.php(24): Process->_delete() 

How do I run a bat file in the background from another bat file?

This works on my Windows XP Home installation, the Unix way:

call notepad.exe & 

Create SQL script that create database and tables

Yes, you can add as many SQL statements into a single script as you wish. Just one thing to note: the order matters. You can't INSERT into a table until you CREATE it; you can't set a foreign key until the primary key is inserted.

How do I start PowerShell from Windows Explorer?

I'm surprised nobody has given this answer, it's the simplest one. (Must be the year.)

Just Shift + right click in Explorer. Then you can "Open PowerShell window here".

It may be set to Command Prompt by default. If so, you can change this in the Windows 10 Settings: go to Personalization -> Taskbar and enable "Replace Command Prompt with Windows PowerShell in the menu when I right-click the start button or press Windows key+X".

Can jQuery provide the tag name?

Since I've hit this question once before and it didn't help me in my case (I didn't have a this, but instead had a jQuery selector instance). Calling get() will get you the HTML element, by which you can get the nodeName as mentioned above.

this.nodeName; // In a event handler, 'this' is usually the element the event is called on

or

$('.hello:first-child').get(0).nodeName; // Use 'get' or simply access the jQuery Object like an array
$('.hello:first-child')[0].nodeName;     // will get you the original DOM element object

how to use "AND", "OR" for RewriteCond on Apache?

After many struggles and to achive a general, flexible and more readable solution, in my case I ended up saving the ORs results into ENV variables and doing the ANDs of those variables.

# RESULT_ONE = A OR B
RewriteRule ^ - [E=RESULT_ONE:False]
RewriteCond ...A... [OR]
RewriteCond ...B...
RewriteRule ^ - [E=RESULT_ONE:True]

# RESULT_TWO = C OR D
RewriteRule ^ - [E=RESULT_TWO:False]
RewriteCond ...C... [OR]
RewriteCond ...D...
RewriteRule ^ - [E=RESULT_TWO:True]

# if ( RESULT_ONE AND RESULT_TWO ) then ( RewriteRule ...something... )
RewriteCond %{ENV:RESULT_ONE} =True
RewriteCond %{ENV:RESULT_TWO} =True
RewriteRule ...something...

Requirements:

No such keg: /usr/local/Cellar/git

Os X Mojave 10.14 has:

Error: The Command Line Tools header package must be installed on Mojave.

Solution. Go to

/Library/Developer/CommandLineTools/Packages/macOS_SDK_headers_for_macOS_10.14.pkg

location and install the package manually. And brew will start working and we can run:

brew uninstall --force git
brew cleanup --force -s git
brew prune
brew install git

How to insert text with single quotation sql server 2005

The answer really depends on how you are doing the INSERT.

If you are specifying a SQL literal then you need to use the double-tick approach:

-- Direct insert
INSERT INTO Table1 (Column1) VALUES ('John''s')

-- Using a parameter, with a direct insert
DECLARE @Value varchar(50)
SET @Value = 'John''s'
INSERT INTO Table1 (Column1) VALUES (@Value)

-- Using a parameter, with dynamic SQL
DECLARE @Value varchar(50)
SET @Value = 'John''s'
EXEC sp_executesql 'INSERT INTO Table1 (Column1) VALUES (@p1)', '@p1 varchar(50)', @Value

If you are doing the INSERT from code, use parameters:

// Sample ADO.NET
using (SqlConnection conn = new SqlConnection(connectionString)) {
    conn.Open();
    using (SqlCommand command = conn.CreateCommand()) {
        command.CommandText = "INSERT INTO Table1 (Column1) VALUES (@Value)";

        command.Parameters.AddWithValue("@Value", "John's");

        command.ExecuteNonQuery();
    }
}

If your data contains user-input, direct or indirect, USE PARAMETERS. Parameters protect against SQL Injection attacks. Never ever build up dynamic SQL with user-input.

Redirect output of mongo query to a csv file

Just weighing in here with a nice solution I have been using. This is similar to Lucky Soni's solution above in that it supports aggregation, but doesn't require hard coding of the field names.

cursor = db.<collection_name>.<my_query_with_aggregation>;

headerPrinted = false;
while (cursor.hasNext()) {
    item = cursor.next();
    
    if (!headerPrinted) {
        print(Object.keys(item).join(','));
        headerPrinted = true;
    }

    line = Object
        .keys(item)
        .map(function(prop) {
            return '"' + item[prop] + '"';
        })
        .join(',');
    print(line);
}

Save this as a .js file, in this case we'll call it example.js and run it with the mongo command line like so:

mongo <database_name> example.js --quiet > example.csv

React - Display loading screen while DOM is rendering?

I also used @Ori Drori's answer and managed to get it to work. As your React code grows, so will the bundles compiled that the client browser will have to download on first time access. This imposes a user experience issue if you don't handle it well.

What I added to @Ori answer was to add and execute the onload function in the index.html on onload attribute of the body tag, so that the loader disappear after everything has been fully loaded in the browse, see the snippet below:

<html>
  <head>
     <style>
       .loader:empty {
          position: absolute;
          top: calc(50% - 4em);
          left: calc(50% - 4em);
          width: 6em;
          height: 6em;
          border: 1.1em solid rgba(0, 0, 0, 0.2);
          border-left: 1.1em solid #000000;
          border-radius: 50%;
          animation: load8 1.1s infinite linear;
        }
        @keyframes load8 {
          0% {
           transform: rotate(0deg);
          }
          100% {
           transform: rotate(360deg);
          }
        }
     </style>
     <script>
       function onLoad() {
         var loader = document.getElementById("cpay_loader");loader.className = "";}
     </script>
   </head>
   <body onload="onLoad();">
     more html here.....
   </body>
</html>

How to make a div have a fixed size?

you can give it a max-height and max-width in your .css

.fontpixel{max-width:200px; max-height:200px;}

in addition to your height and width properties

What causes "Unable to access jarfile" error?

For me the problem got resolved after accessing the folder in which the jar was placed earlier I was giving command on D: drive, but when I navigated to the folder in which that jar was placed this problem got resolved

Java 32-bit vs 64-bit compatibility

All byte code is 8-bit based. (That's why its called BYTE code) All the instructions are a multiple of 8-bits in size. We develop on 32-bit machines and run our servers with 64-bit JVM.

Could you give some detail of the problem you are facing? Then we might have a chance of helping you. Otherwise we would just be guessing what the problem is you are having.

Markdown: continue numbered list

If you want to have text aligned to preceding list item but avoid having "big" line break, use two spaces at the end of a list item and indent the text with some spaces.

Source: (dots are spaces ;-) of course)

1.·item1··
····This is some text
2.item2

Result:

  1. item1
    This is some text
  2. item2

Avoid "current URL string parser is deprecated" warning by setting useNewUrlParser to true

I was using mlab.com as the MongoDB database. I separated the connection string to a different folder named config and inside file keys.js I kept the connection string which was:

_x000D_
_x000D_
module.exports = {_x000D_
  mongoURI: "mongodb://username:[email protected]:47267/projectname"_x000D_
};
_x000D_
_x000D_
_x000D_

And the server code was

_x000D_
_x000D_
const express = require("express");_x000D_
const mongoose = require("mongoose");_x000D_
const app = express();_x000D_
_x000D_
// Database configuration_x000D_
const db = require("./config/keys").mongoURI;_x000D_
_x000D_
// Connect to MongoDB_x000D_
_x000D_
mongoose_x000D_
  .connect(_x000D_
    db,_x000D_
    { useNewUrlParser: true } // Need this for API support_x000D_
  )_x000D_
  .then(() => console.log("MongoDB connected"))_x000D_
  .catch(err => console.log(err));_x000D_
_x000D_
app.get("/", (req, res) => res.send("hello!!"));_x000D_
_x000D_
const port = process.env.PORT || 5000;_x000D_
_x000D_
app.listen(port, () => console.log(`Server running on port ${port}`)); // Tilde, not inverted comma
_x000D_
_x000D_
_x000D_

You need to write { useNewUrlParser: true } after the connection string as I did above.

Simply put, you need to do:

_x000D_
_x000D_
mongoose.connect(connectionString,{ useNewUrlParser: true } _x000D_
// Or_x000D_
MongoClient.connect(connectionString,{ useNewUrlParser: true } _x000D_
    
_x000D_
_x000D_
_x000D_

How do you properly use namespaces in C++?

Don't listen to every people telling you that namespaces are just name-spaces.

They are important because they are considered by the compiler to apply the interface principle. Basically, it can be explained by an example:

namespace ns {

class A
{
};

void print(A a)
{
}

}

If you wanted to print an A object, the code would be this one:

ns::A a;
print(a);

Note that we didn't explicitly mention the namespace when calling the function. This is the interface principle: C++ consider a function taking a type as an argument as being part of the interface for that type, so no need to specify the namespace because the parameter already implied the namespace.

Now why this principle is important? Imagine that the class A author did not provide a print() function for this class. You will have to provide one yourself. As you are a good programmer, you will define this function in your own namespace, or maybe in the global namespace.

namespace ns {

class A
{
};

}

void print(A a)
{
}

And your code can start calling the print(a) function wherever you want. Now imagine that years later, the author decides to provide a print() function, better than yours because he knows the internals of his class and can make a better version than yours.

Then C++ authors decided that his version of the print() function should be used instead of the one provided in another namespace, to respect the interface principle. And that this "upgrade" of the print() function should be as easy as possible, which means that you won't have to change every call to the print() function. That's why "interface functions" (function in the same namespace as a class) can be called without specifying the namespace in C++.

And that's why you should consider a C++ namespace as an "interface" when you use one and keep in mind the interface principle.

If you want better explanation of this behavior, you can refer to the book Exceptional C++ from Herb Sutter

How to define several include path in Makefile

You have to prepend every directory with -I:

INC=-I/usr/informix/incl/c++ -I/opt/informix/incl/public

On delete cascade with doctrine2

Here is simple example. A contact has one to many associated phone numbers. When a contact is deleted, I want all its associated phone numbers to also be deleted, so I use ON DELETE CASCADE. The one-to-many/many-to-one relationship is implemented with by the foreign key in the phone_numbers.

CREATE TABLE contacts
 (contact_id BIGINT AUTO_INCREMENT NOT NULL,
 name VARCHAR(75) NOT NULL,
 PRIMARY KEY(contact_id)) ENGINE = InnoDB;

CREATE TABLE phone_numbers
 (phone_id BIGINT AUTO_INCREMENT NOT NULL,
  phone_number CHAR(10) NOT NULL,
 contact_id BIGINT NOT NULL,
 PRIMARY KEY(phone_id),
 UNIQUE(phone_number)) ENGINE = InnoDB;

ALTER TABLE phone_numbers ADD FOREIGN KEY (contact_id) REFERENCES \
contacts(contact_id) ) ON DELETE CASCADE;

By adding "ON DELETE CASCADE" to the foreign key constraint, phone_numbers will automatically be deleted when their associated contact is deleted.

INSERT INTO table contacts(name) VALUES('Robert Smith');
INSERT INTO table phone_numbers(phone_number, contact_id) VALUES('8963333333', 1);
INSERT INTO table phone_numbers(phone_number, contact_id) VALUES('8964444444', 1);

Now when a row in the contacts table is deleted, all its associated phone_numbers rows will automatically be deleted.

DELETE TABLE contacts as c WHERE c.id=1; /* delete cascades to phone_numbers */

To achieve the same thing in Doctrine, to get the same DB-level "ON DELETE CASCADE" behavoir, you configure the @JoinColumn with the onDelete="CASCADE" option.

<?php
namespace Entities;

use Doctrine\Common\Collections\ArrayCollection;

/**
 * @Entity
 * @Table(name="contacts")
 */
class Contact 
{

    /**
     *  @Id
     *  @Column(type="integer", name="contact_id") 
     *  @GeneratedValue
     */
    protected $id;  

    /** 
     * @Column(type="string", length="75", unique="true") 
     */ 
    protected $name; 

    /** 
     * @OneToMany(targetEntity="Phonenumber", mappedBy="contact")
     */ 
    protected $phonenumbers; 

    public function __construct($name=null)
    {
        $this->phonenumbers = new ArrayCollection();

        if (!is_null($name)) {

            $this->name = $name;
        }
    }

    public function getId()
    {
        return $this->id;
    }

    public function setName($name)
    {
        $this->name = $name;
    }

    public function addPhonenumber(Phonenumber $p)
    {
        if (!$this->phonenumbers->contains($p)) {

            $this->phonenumbers[] = $p;
            $p->setContact($this);
        }
    }

    public function removePhonenumber(Phonenumber $p)
    {
        $this->phonenumbers->remove($p);
    }
}

<?php
namespace Entities;

/**
 * @Entity
 * @Table(name="phonenumbers")
 */
class Phonenumber 
{

    /**
    * @Id
    * @Column(type="integer", name="phone_id") 
    * @GeneratedValue
    */
    protected $id; 

    /**
     * @Column(type="string", length="10", unique="true") 
     */  
    protected $number;

    /** 
     * @ManyToOne(targetEntity="Contact", inversedBy="phonenumbers")
     * @JoinColumn(name="contact_id", referencedColumnName="contact_id", onDelete="CASCADE")
     */ 
    protected $contact; 

    public function __construct($number=null)
    {
        if (!is_null($number)) {

            $this->number = $number;
        }
    }

    public function setPhonenumber($number)
    {
        $this->number = $number;
    }

    public function setContact(Contact $c)
    {
        $this->contact = $c;
    }
} 
?>

<?php

$em = \Doctrine\ORM\EntityManager::create($connectionOptions, $config);

$contact = new Contact("John Doe"); 

$phone1 = new Phonenumber("8173333333");
$phone2 = new Phonenumber("8174444444");
$em->persist($phone1);
$em->persist($phone2);
$contact->addPhonenumber($phone1); 
$contact->addPhonenumber($phone2); 

$em->persist($contact);
try {

    $em->flush();
} catch(Exception $e) {

    $m = $e->getMessage();
    echo $m . "<br />\n";
}

If you now do

# doctrine orm:schema-tool:create --dump-sql

you will see that the same SQL will be generated as in the first, raw-SQL example

Java Byte Array to String to Byte Array

Can you not just send the bytes as bytes, or convert each byte to a character and send as a string? Doing it like you are will take up a minimum of 85 characters in the string, when you only have 11 bytes to send. You could create a string representation of the bytes, so it'd be "[B@405217f8", which can easily be converted to a bytes or bytearray object in Python. Failing that, you could represent them as a series of hexadecimal digits ("5b42403430353231376638") taking up 22 characters, which could be easily decoded on the Python side using binascii.unhexlify().

Work on a remote project with Eclipse via SSH

The very simplest way would be to run Eclipse CDT on the Linux Box and use either X11-Forwarding or remote desktop software such as VNC.

This, of course, is only possible when you Eclipse is present on the Linux box and your network connection to the box is sufficiently fast.

The advantage is that, due to everything being local, you won't have synchronization issues, and you don't get any awkward cross-platform issues.

If you have no eclipse on the box, you could thinking of sharing your linux working directory via SMB (or SSHFS) and access it from your windows machine, but that would require quite some setup.

Both would be better than having two copies, especially when it's cross-platform.

Python 2: AttributeError: 'list' object has no attribute 'strip'

You split the string entry of the list. l[0].strip()

Error message "Strict standards: Only variables should be passed by reference"

Consider the following code:

error_reporting(E_STRICT);
class test {
    function test_arr(&$a) {
        var_dump($a);
    }
    function get_arr() {
        return array(1, 2);
    }
}

$t = new test;
$t->test_arr($t->get_arr());

This will generate the following output:

Strict Standards: Only variables should be passed by reference in `test.php` on line 14
array(2) {
  [0]=>
  int(1)
  [1]=>
  int(2)
}

The reason? The test::get_arr() method is not a variable and under strict mode this will generate a warning. This behavior is extremely non-intuitive as the get_arr() method returns an array value.

To get around this error in strict mode, either change the signature of the method so it doesn't use a reference:

function test_arr($a) {
    var_dump($a);
}

Since you can't change the signature of array_shift you can also use an intermediate variable:

$inter = get_arr();
$el = array_shift($inter);

How do I pass the this context to a function?

You can use the bind function to set the context of this within a function.

function myFunc() {
  console.log(this.str)
}
const myContext = {str: "my context"}
const boundFunc = myFunc.bind(myContext);
boundFunc(); // "my context"

Last element in .each() set

A shorter answer from here, adapted to this question:

var arr = $('.requiredText');
arr.each(function(index, item) {
   var is_last_item = (index == (arr.length - 1));
});

Just for completeness.

How to remove index.php from URLs?

I tried everything on the post but nothing had worked. I then changed the .htaccess snippet that ErJab put up to read:

RewriteRule ^(.*)$ 'folder_name'/index.php/$1 [L]

The above line fixed it for me. where *folder_name* is the magento root folder.

Hope this helps!

How to set a selected option of a dropdown list control using angular JS

This is the code what I used for the set selected value

_x000D_
_x000D_
countryList: any = [{ "value": "AF", "group": "A", "text": "Afghanistan"}, { "value": "AL", "group": "A", "text": "Albania"}, { "value": "DZ", "group": "A", "text": "Algeria"}, { "value": "AD", "group": "A", "text": "Andorra"}, { "value": "AO", "group": "A", "text": "Angola"}, { "value": "AR", "group": "A", "text": "Argentina"}, { "value": "AM", "group": "A", "text": "Armenia"}, { "value": "AW", "group": "A", "text": "Aruba"}, { "value": "AU", "group": "A", "text": "Australia"}, { "value": "AT", "group": "A", "text": "Austria"}, { "value": "AZ", "group": "A", "text": "Azerbaijan"}];_x000D_
 _x000D_
 _x000D_
 for (var j = 0; j < countryList.length; j++) {_x000D_
      //debugger_x000D_
      if (countryList[j].text == "Australia") {_x000D_
          console.log(countryList[j].text); _x000D_
          countryList[j].isSelected = 'selected';_x000D_
      }_x000D_
      }
_x000D_
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/16.6.3/umd/react.production.min.js"></script>_x000D_
<script src="https://cdnjs.cloudflare.com/ajax/libs/react-dom/16.6.3/umd/react-dom.production.min.js"></script>_x000D_
<script src="https://cdnjs.cloudflare.com/ajax/libs/angular.js/1.7.5/angular.min.js"></script>_x000D_
<label>Country</label>_x000D_
<select class="custom-select col-12" id="Country" name="Country"   >_x000D_
<option value="0" selected>Choose...</option>_x000D_
<option *ngFor="let country of countryList" value="{{country.text}}" selected="{{country.isSelected}}"   > {{country.text}}</option>_x000D_
</select>
_x000D_
_x000D_
_x000D_

try this on an angular framework

How do I add a Font Awesome icon to input field?

Change your input to a button element and you can use the Font Awesome classes on it. The alignment of the glyph isn't great in the demo, but you get the idea:

http://tinker.io/802b6/1

<div id="search-bar">
  <form method="get" action="search.php" autocomplete="off" name="form_search">
    <input type="hidden" name="type" value="videos" />
        <input autocomplete="on" id="keyword" name="keyword" value="Search Videos" onclick="clickclear(this,
        'Search Videos')" onblur="clickrecall(this,'Search Videos')" style="font-family: verdana; font-weight:bold;
        font-size: 10pt; height: 28px; width:186px; color: #000000; padding-left: 2px; border: 1px solid black; background-color:
        #ffffff" /><!--
        --><button class="icon-search">Search</button>
    <div id="searchBoxSuggestions"></div>
    </form>
</div>

#search-bar .icon-search {
    width: 30px;
    height: 30px;
    background: black;
    color: white;
    border: none;
    overflow: hidden;
    vertical-align: middle;
    padding: 0;
}

#search-bar .icon-search:before {
    display: inline-block;
    width: 30px;
    height: 30px;
}

The advantage here is that the form is still fully functional without having to add event handlers for elements that aren't buttons but look like one.

JavaScript getElementByID() not working

Because when the script executes the browser has not yet parsed the <body>, so it does not know that there is an element with the specified id.

Try this instead:

<html>
<head>
    <title></title>
    <script type="text/javascript">
        window.onload = (function () {
            var refButton = document.getElementById("btnButton");

            refButton.onclick = function() {
                alert('Dhoor shala!');
            };
        });
    </script>
    </head>
<body>
    <form id="form1">
    <div>
        <input id="btnButton" type="button" value="Click me"/>
    </div>
</form>
</body>
</html>

Note that you may as well use addEventListener instead of window.onload = ... to make that function only execute after the whole document has been parsed.

best way to preserve numpy arrays on disk

savez() save data in a zip file, It may take some time to zip & unzip the file. You can use save() & load() function:

f = file("tmp.bin","wb")
np.save(f,a)
np.save(f,b)
np.save(f,c)
f.close()

f = file("tmp.bin","rb")
aa = np.load(f)
bb = np.load(f)
cc = np.load(f)
f.close()

To save multiple arrays in one file, you just need to open the file first, and then save or load the arrays in sequence.

VBA EXCEL Multiple Nested FOR Loops that Set two variable for expression

I can't get to your google docs file at the moment but there are some issues with your code that I will try to address while answering

Sub stituterangersNEW()
Dim t As Range
Dim x As Range
Dim dify As Boolean
Dim difx As Boolean
Dim time2 As Date
Dim time1 As Date

    'You said time1 doesn't change, so I left it in a singe cell.
    'If that is not correct, you will have to play with this some more.
    time1 = Range("A6").Value

    'Looping through each of our output cells.
    For Each t In Range("B7:E9") 'Change these to match your real ranges.

        'Looping through each departure date/time.
        '(Only one row in your example. This can be adjusted if needed.)
        For Each x In Range("B2:E2") 'Change these to match your real ranges.
            'Check to see if our dep time corresponds to
            'the matching column in our output
            If t.Column = x.Column Then
                'If it does, then check to see what our time value is
                If x > 0 Then
                    time2 = x.Value
                    'Apply the change to the output cell.
                    t.Value = time1 - time2
                    'Exit out of this loop and move to the next output cell.
                    Exit For
                End If
            End If
            'If the columns don't match, or the x value is not a time
            'then we'll move to the next dep time (x)
        Next x
    Next t

End Sub

EDIT

I changed you worksheet to play with (see above for the new Sub). This probably does not suite your needs directly, but hopefully it will demonstrate the conept behind what I think you want to do. Please keep in mind that this code does not follow all the coding best preactices I would recommend (e.g. validating the time is actually a TIME and not some random other data type).

     A                      B                   C                   D                  E
1    LOAD_NUMBER            1                   2                   3                  4
2    DEPARTURE_TIME_DATE    11/12/2011 19:30    11/12/2011 19:30    11/12/2011 19:30    11/12/2011 20:00                
4    Dry_Refrig 7585.1  0   10099.8 16700
6    1/4/2012 19:30

Using the sub I got this output:

    A           B             C             D             E
7   Friday      1272:00:00    1272:00:00    1272:00:00    1271:30:00
8   Saturday    1272:00:00    1272:00:00    1272:00:00    1271:30:00
9   Thursday    1272:00:00    1272:00:00    1272:00:00    1271:30:00

Return string without trailing slash

function someFunction(site) {
  if (site.indexOf('/') > 0)
    return site.substring(0, site.indexOf('/'));
  return site;
}

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

If you want to allow all origins and keep credentials true, this worked for me:

app.use(cors({
  origin: function(origin, callback){
    return callback(null, true);
  },
  optionsSuccessStatus: 200,
  credentials: true
}));

Splitting templated C++ classes into .hpp/.cpp files--is it possible?

The place where you might want to do this is when you create a library and header combination, and hide the implementation to the user. Therefore, the suggested approach is to use explicit instantiation, because you know what your software is expected to deliver, and you can hide the implementations.

Some useful information is here: https://docs.microsoft.com/en-us/cpp/cpp/explicit-instantiation?view=vs-2019

For your same example: Stack.hpp

template <class T>
class Stack {

public:
    Stack();
    ~Stack();
    void Push(T val);
    T Pop();
private:
    T val;
};


template class Stack<int>;

stack.cpp

#include <iostream>
#include "Stack.hpp"
using namespace std;

template<class T>
void Stack<T>::Push(T val) {
    cout << "Pushing Value " << endl;
    this->val = val;
}

template<class T>
T Stack<T>::Pop() {
    cout << "Popping Value " << endl;
    return this->val;
}

template <class T> Stack<T>::Stack() {
    cout << "Construct Stack " << this << endl;
}

template <class T> Stack<T>::~Stack() {
    cout << "Destruct Stack " << this << endl;
}

main.cpp

#include <iostream>
using namespace std;

#include "Stack.hpp"

int main() {
    Stack<int> s;
    s.Push(10);
    cout << s.Pop() << endl;
    return 0;
}

Output:

> Construct Stack 000000AAC012F8B4
> Pushing Value
> Popping Value
> 10
> Destruct Stack 000000AAC012F8B4

I however don't entirely like this approach, because this allows the application to shoot itself in the foot, by passing incorrect datatypes to the templated class. For instance, in the main function, you can pass other types that can be implicitly converted to int like s.Push(1.2); and that is just bad in my opinion.

CSS :: child set to change color on parent hover, but changes also when hovered itself

Update

The below made sense for 2013. However, now, I would use the :not() selector as described below.


CSS can be overwritten.

DEMO: http://jsfiddle.net/persianturtle/J4SUb/

Use this:

_x000D_
_x000D_
.parent {
  padding: 50px;
  border: 1px solid black;
}

.parent span {
  position: absolute;
  top: 200px;
  padding: 30px;
  border: 10px solid green;
}

.parent:hover span {
  border: 10px solid red;
}

.parent span:hover {
  border: 10px solid green;
}
_x000D_
<a class="parent">
    Parent text
    <span>Child text</span>    
</a>
_x000D_
_x000D_
_x000D_

Android: Unable to add window. Permission denied for this window type

Firstly you make sure you have add permission in manifest file.

<uses-permission android:name="android.permission.SYSTEM_ALERT_WINDOW"/>

Check if the application has draw over other apps permission or not? This permission is by default available for API<23. But for API > 23 you have to ask for the permission in runtime.

 if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M && !Settings.canDrawOverlays(this)) {

    Intent intent = new Intent(Settings.ACTION_MANAGE_OVERLAY_PERMISSION,
            Uri.parse("package:" + getPackageName()));
    startActivityForResult(intent, 1);
} 

Use This code:

public class ChatHeadService extends Service {

private WindowManager mWindowManager;
private View mChatHeadView;

WindowManager.LayoutParams params;

public ChatHeadService() {
}

@Override
public IBinder onBind(Intent intent) {
    return null;
}

@Override
public void onCreate() {
    super.onCreate();

    Language language = new Language();
    //Inflate the chat head layout we created
    mChatHeadView = LayoutInflater.from(this).inflate(R.layout.dialog_incoming_call, null);


    if (Build.VERSION.SDK_INT < Build.VERSION_CODES.O) {
        params = new WindowManager.LayoutParams(
                WindowManager.LayoutParams.WRAP_CONTENT,
                WindowManager.LayoutParams.WRAP_CONTENT,
                WindowManager.LayoutParams.TYPE_PHONE,
                WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE
                        | WindowManager.LayoutParams.FLAG_NOT_TOUCH_MODAL
                        | WindowManager.LayoutParams.FLAG_WATCH_OUTSIDE_TOUCH
                        | WindowManager.LayoutParams.FLAG_LAYOUT_NO_LIMITS,
                PixelFormat.TRANSLUCENT);

        params.gravity = Gravity.CENTER_HORIZONTAL | Gravity.TOP;
        params.x = 0;
        params.y = 100;
        mWindowManager = (WindowManager) getSystemService(WINDOW_SERVICE);
        mWindowManager.addView(mChatHeadView, params);

    } else {
        params = new WindowManager.LayoutParams(
                WindowManager.LayoutParams.WRAP_CONTENT,
                WindowManager.LayoutParams.WRAP_CONTENT,
                WindowManager.LayoutParams.TYPE_APPLICATION_OVERLAY,
                WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE
                        | WindowManager.LayoutParams.FLAG_NOT_TOUCH_MODAL
                        | WindowManager.LayoutParams.FLAG_WATCH_OUTSIDE_TOUCH
                        | WindowManager.LayoutParams.FLAG_LAYOUT_NO_LIMITS,
                PixelFormat.TRANSLUCENT);


        params.gravity = Gravity.CENTER_HORIZONTAL | Gravity.TOP;
        params.x = 0;
        params.y = 100;
        mWindowManager = (WindowManager) getSystemService(WINDOW_SERVICE);
        mWindowManager.addView(mChatHeadView, params);
    }

    TextView tvTitle=mChatHeadView.findViewById(R.id.tvTitle);
    tvTitle.setText("Incoming Call");

    //Set the close button.
    Button btnReject = (Button) mChatHeadView.findViewById(R.id.btnReject);
    btnReject.setText(language.getText(R.string.reject));
    btnReject.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            //close the service and remove the chat head from the window
            stopSelf();
        }
    });

    //Drag and move chat head using user's touch action.
    final Button btnAccept = (Button) mChatHeadView.findViewById(R.id.btnAccept);
    btnAccept.setText(language.getText(R.string.accept));


    LinearLayout linearLayoutMain=mChatHeadView.findViewById(R.id.linearLayoutMain);



    linearLayoutMain.setOnTouchListener(new View.OnTouchListener() {
        private int lastAction;
        private int initialX;
        private int initialY;
        private float initialTouchX;
        private float initialTouchY;

        @Override
        public boolean onTouch(View v, MotionEvent event) {
            switch (event.getAction()) {
                case MotionEvent.ACTION_DOWN:

                    //remember the initial position.
                    initialX = params.x;
                    initialY = params.y;

                    //get the touch location
                    initialTouchX = event.getRawX();
                    initialTouchY = event.getRawY();

                    lastAction = event.getAction();
                    return true;
                case MotionEvent.ACTION_UP:
                    //As we implemented on touch listener with ACTION_MOVE,
                    //we have to check if the previous action was ACTION_DOWN
                    //to identify if the user clicked the view or not.
                    if (lastAction == MotionEvent.ACTION_DOWN) {
                        //Open the chat conversation click.
                        Intent intent = new Intent(ChatHeadService.this, HomeActivity.class);
                        intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
                        startActivity(intent);

                        //close the service and remove the chat heads
                        stopSelf();
                    }
                    lastAction = event.getAction();
                    return true;
                case MotionEvent.ACTION_MOVE:
                    //Calculate the X and Y coordinates of the view.
                    params.x = initialX + (int) (event.getRawX() - initialTouchX);
                    params.y = initialY + (int) (event.getRawY() - initialTouchY);

                    //Update the layout with new X & Y coordinate
                    mWindowManager.updateViewLayout(mChatHeadView, params);
                    lastAction = event.getAction();
                    return true;
            }
            return false;
        }
    });
}

@Override
public void onDestroy() {
    super.onDestroy();
    if (mChatHeadView != null) mWindowManager.removeView(mChatHeadView);
}

}

Java regular expression OR operator

You can just use the pipe on its own:

"string1|string2"

for example:

String s = "string1, string2, string3";
System.out.println(s.replaceAll("string1|string2", "blah"));

Output:

blah, blah, string3

The main reason to use parentheses is to limit the scope of the alternatives:

String s = "string1, string2, string3";
System.out.println(s.replaceAll("string(1|2)", "blah"));

has the same output. but if you just do this:

String s = "string1, string2, string3";
System.out.println(s.replaceAll("string1|2", "blah"));

you get:

blah, stringblah, string3

because you've said "string1" or "2".

If you don't want to capture that part of the expression use ?::

String s = "string1, string2, string3";
System.out.println(s.replaceAll("string(?:1|2)", "blah"));

How to make the tab character 4 spaces instead of 8 spaces in nano?

If you use nano with a language like python (as in your example) it's also a good idea to convert tabs to spaces.

Edit your ~/.nanorc file (or create it) and add:

set tabsize 4
set tabstospaces

If you already got a file with tabs and want to convert them to spaces i recommend the expandcommand (shell):

expand -4 input.py > output.py

Find running median from a stream of integers

The most efficient way to calculate a percentile of a stream that I have found is the P² algorithm: Raj Jain, Imrich Chlamtac: The P² Algorithm for Dynamic Calculation of Quantiiles and Histograms Without Storing Observations. Commun. ACM 28(10): 1076-1085 (1985)

The algorithm is straight forward to implement and works extremely well. It is an estimate, however, so keep that in mind. From the abstract:

A heuristic algorithm is proposed for dynamic calculation qf the median and other quantiles. The estimates are produced dynamically as the observations are generated. The observations are not stored; therefore, the algorithm has a very small and fixed storage requirement regardless of the number of observations. This makes it ideal for implementing in a quantile chip that can be used in industrial controllers and recorders. The algorithm is further extended to histogram plotting. The accuracy of the algorithm is analyzed.

Java Mouse Event Right Click

To avoid any ambiguity, use the utilities methods from SwingUtilities :

SwingUtilities.isLeftMouseButton(MouseEvent anEvent) SwingUtilities.isRightMouseButton(MouseEvent anEvent) SwingUtilities.isMiddleMouseButton(MouseEvent anEvent)

Enum Naming Convention - Plural

I started out naming enums in the plural but have since changed to singular. Just seems to make more sense in the context of where they're used.

enum Status { Unknown = 0, Incomplete, Ready }

Status myStatus = Status.Ready;

Compare to:

Statuses myStatus = Statuses.Ready;

I find the singular form to sound more natural in context. We are in agreement that when declaring the enum, which happens in one place, we're thinking "this is a group of whatevers", but when using it, presumably in many places, that we're thinking "this is one whatever".

Primary key or Unique index?

You can see it like this:

A Primary Key IS Unique

A Unique value doesn't have to be the Representaion of the Element

Meaning?; Well a primary key is used to identify the element, if you have a "Person" you would like to have a Personal Identification Number ( SSN or such ) which is Primary to your Person.

On the other hand, the person might have an e-mail which is unique, but doensn't identify the person.

I always have Primary Keys, even in relationship tables ( the mid-table / connection table ) I might have them. Why? Well I like to follow a standard when coding, if the "Person" has an identifier, the Car has an identifier, well, then the Person -> Car should have an identifier as well!

Rails has_many with alias name

To complete @SamSaffron's answer :

You can use class_name with either foreign_key or inverse_of. I personally prefer the more abstract declarative, but it's really just a matter of taste :

class BlogPost
  has_many :images, class_name: "BlogPostImage", inverse_of: :blog_post  
end

and you need to make sure you have the belongs_to attribute on the child model:

class BlogPostImage
  belongs_to :blog_post
end

Can an AWS Lambda function call another

This solution is done using boto3 and Python:

import boto3
import json

invokeLambda = boto3.client('lambda', region_name='eu-west-1')

def lambda_handler(event, context):
    invokeLambda.invoke(FunctionName = 'function_name', InvocationType = 'RequestResponse', Payload = json.dumps(event))

    return True

Java - sending HTTP parameters via POST method easily

For those having trouble receiving the request on a php page using $_POST because you expect key-value pairs:

While all the answers where very helpful, I lacked some basic understanding on which string actually to post, since in the old apache HttpClient I used

new UrlEncodedFormEntity(nameValuePairs); (Java)

and then could use $_POST in php do get the key-value pairs.

To my understanding now one has build that string manually before posting. So the string needs to look like

val data = "key1=val1&key2=val2"

but instead just adding it to the url it is posted (in the header).

The alternative would be to use a json-string instead:

val data = "{\"key1\":\"val1\",\"key2\":\"val2\"}" // {"key1":"val1","key2":"val2"}

and pull it in php without $_POST:

$json_params = file_get_contents('php://input');
// echo_p("Data: $json_params");
$data = json_decode($json_params, true);

Here you find a sample code in Kotlin:

class TaskDownloadTest : AsyncTask<Void, Void, Void>() {
    override fun doInBackground(vararg params: Void): Void? {
        var urlConnection: HttpURLConnection? = null

        try {

            val postData = JsonObject()
            postData.addProperty("key1", "val1")
            postData.addProperty("key2", "val2")

            // reformat json to key1=value1&key2=value2
            // keeping json because I may change the php part to interpret json requests, could be a HashMap instead
            val keys = postData.keySet()
            var request = ""
            keys.forEach { key ->
                // Log.i("data", key)
                request += "$key=${postData.get(key)}&"
            }
            request = request.replace("\"", "").removeSuffix("&")
            val requestLength = request.toByteArray().size
            // Warning in Android 9 you need to add a line in the application part of the manifest: android:usesCleartextTraffic="true"
            // https://stackoverflow.com/questions/45940861/android-8-cleartext-http-traffic-not-permitted
            val url = URL("http://10.0.2.2/getdata.php")
            urlConnection = url.openConnection() as HttpURLConnection
            // urlConnection.setRequestProperty("Content-Type", "application/x-www-form-urlencoded") // apparently default
            // Not sure what these are for, I do not use them
            // urlConnection.setRequestProperty("Content-Type", "application/json")
            // urlConnection.setRequestProperty("Key","Value")
            urlConnection.readTimeout = 5000
            urlConnection.connectTimeout = 5000
            urlConnection.requestMethod = "POST"
            urlConnection.doOutput = true
            // urlConnection.doInput = true
            urlConnection.useCaches = false
            urlConnection.setFixedLengthStreamingMode(requestLength)
            // urlConnection.setChunkedStreamingMode(0) // if you do not want to handle request length which is fine for small requests

            val out = urlConnection.outputStream
            val writer = BufferedWriter(
                OutputStreamWriter(
                    out, "UTF-8"
                )
            )
            writer.write(request)
            // writer.write("{\"key1\":\"val1\",\"key2\":\"val2\"}") // {"key1":"val1","key2":"val2"} JsonFormat or just postData.toString() for $json_params=file_get_contents('php://input'); json_decode($json_params, true); in php
            // writer.write("key1=val1&key2=val2") // key=value format for $_POST in php
            writer.flush()
            writer.close()
            out.close()

            val code = urlConnection.responseCode
            if (code != 200) {
                throw IOException("Invalid response from server: $code")
            }

            val rd = BufferedReader(
                InputStreamReader(
                    urlConnection.inputStream
                )
            )
            var line = rd.readLine()
            while (line != null) {
                Log.i("data", line)
                line = rd.readLine()
            }
        } catch (e: Exception) {
            e.printStackTrace()
        } finally {
            urlConnection?.disconnect()
        }

        return null
    }
}

Rounding a variable to two decimal places C#

decimal pay  = 1.994444M;

Math.Round(pay , 2); 

static const vs #define

  • A static const is typed (it has a type) and can be checked by the compiler for validity, redefinition etc.
  • a #define can be redifined undefined whatever.

Usually you should prefer static consts. It has no disadvantage. The prprocessor should mainly be used for conditional compilation (and sometimes for really dirty trics maybe).

How can I get dictionary key as variable directly in Python (not by searching from value)?

keys=[i for i in mydictionary.keys()] or keys = list(mydictionary.keys())

Concatenate text files with Windows command line, dropping leading lines

Use the FOR command to echo a file line by line, and with the 'skip' option to miss a number of starting lines...

FOR /F "skip=1" %i in (file2.txt) do @echo %i

You could redirect the output of a batch file, containing something like...

FOR /F %%i in (file1.txt) do @echo %%i
FOR /F "skip=1" %%i in (file2.txt) do @echo %%i

Note the double % when a FOR variable is used within a batch file.

Centering a button vertically in table cell, using Twitter Bootstrap

add this to your css

.table-vcenter td {
   vertical-align: middle!important;
}

then add to the class to your table:

        <table class="table table-hover table-striped table-vcenter">

How to get thread id of a pthread in linux c program?

What? The person asked for Linux specific, and the equivalent of getpid(). Not BSD or Apple. The answer is gettid() and returns an integral type. You will have to call it using syscall(), like this:

#include <sys/types.h>
#include <unistd.h>
#include <sys/syscall.h>

 ....

 pid_t x = syscall(__NR_gettid);

While this may not be portable to non-linux systems, the threadid is directly comparable and very fast to acquire. It can be printed (such as for LOGs) like a normal integer.

What is the difference between Serialization and Marshaling?

Think of them as synonyms, both have a producer that sends stuff over to a consumer... In the end fields of instances are written into a byte stream and the other end foes the reverse ands up with the same instances.

NB - java RMI also contains support for transporting classes that are missing from the recipient...

Hide horizontal scrollbar on an iframe?

set scrolling="no" attribute in your iframe.

How to represent empty char in Java Character class

this is how I do it.

char[] myEmptyCharArray = "".toCharArray();

SQLSTATE[HY000] [2002] php_network_getaddresses: getaddrinfo failed: Name or service not known

In my case, everything was set up correctly, but my Docker infrastructure needed more RAM. I'm using Docker for Mac, where default RAM was around 1 GB, and as MySQL uses around 1.5Gb of RAM ( and probably was crashing ??? ), changing the Docker RAM utilization level to 3-4 Gb solved the issue.

Regular expression for checking if capital letters are found consecutively in a string?

Edit: 2015-10-26: thanks for the upvotes - but take a look at tchrist's answer, especially if you develop for the web or something more "international".

Oren Trutners answer isn't quite right (see sample input of "RightHerE" which must be matched but isn't)

Here is the correct solution:

(?!^.*[A-Z]{2,}.*$)^[A-Za-z]*$

edit:

(?!^.*[A-Z]{2,}.*$)  // don't match the whole expression if there are two or more consecutive uppercase letters
^[A-Za-z]*$          // match uppercase and lowercase letters

/edit

the key for the solution is a negative lookahead see: http://www.regular-expressions.info/lookaround.html

check if jquery has been loaded, then load it if false

Avoid using "if (!jQuery)" since IE will return the error: jQuery is 'undefined'

Instead use: if (typeof jQuery == 'undefined')

<script type="text/javascript">
if (typeof jQuery == 'undefined') {
    var script = document.createElement('script');
    script.type = "text/javascript";
    script.src = "http://ajax.googleapis.com/ajax/libs/jquery/1.11.0/jquery.min.js";
    document.getElementsByTagName('head')[0].appendChild(script);
}
</script>

You'll also need to check if the JQuery has loaded after appending it to the header. Otherwise you'll have to wait for the window.onload event, which is slower if the page has images. Here's a sample script which checks if the JQuery file has loaded, since you won't have the convenience of being able to use $(document).ready(function...

http://neighborhood.org/core/sample/jquery/append-to-head.htm

isolating a sub-string in a string before a symbol in SQL Server 2008

DECLARE @dd VARCHAR(200) = 'Net Operating Loss - 2007';

SELECT SUBSTRING(@dd, 1, CHARINDEX('-', @dd) -1) F1,
       SUBSTRING(@dd, CHARINDEX('-', @dd) +1, LEN(@dd)) F2

Base64 String throwing invalid character error

One gotcha to do with converting Base64 from a string is that some conversion functions use the preceding "data:image/jpg;base64," and others only accept the actual data.

How to print out all the elements of a List in Java?

I have faced similar problems. My code:

List<Integer> leaveDatesList = new ArrayList<>();

.....inserted value in list.......

Way 1: printing a list in a for loop

for(int i=0;i<leaveDatesList.size();i++){
    System.out.println(leaveDatesList.get(i));
}

Way 2: printing the list in a forEach, for loop

for(Integer leave : leaveDatesList){
    System.out.println(leave);
}

Way 3: printing the list in java 8

leaveDatesList.forEach(System.out::println);

How to convert a structure to a byte array in C#?

This is fairly easy, using marshalling.

Top of file

using System.Runtime.InteropServices

Function

byte[] getBytes(CIFSPacket str) {
    int size = Marshal.SizeOf(str);
    byte[] arr = new byte[size];

    IntPtr ptr = Marshal.AllocHGlobal(size);
    Marshal.StructureToPtr(str, ptr, true);
    Marshal.Copy(ptr, arr, 0, size);
    Marshal.FreeHGlobal(ptr);
    return arr;
}

And to convert it back:

CIFSPacket fromBytes(byte[] arr) {
    CIFSPacket str = new CIFSPacket();

    int size = Marshal.SizeOf(str);
    IntPtr ptr = Marshal.AllocHGlobal(size);

    Marshal.Copy(arr, 0, ptr, size);

    str = (CIFSPacket)Marshal.PtrToStructure(ptr, str.GetType());
    Marshal.FreeHGlobal(ptr);

    return str;
}

In your structure, you will need to put this before a string

[MarshalAs(UnmanagedType.ByValTStr, SizeConst = 100)]
public string Buffer;

And make sure SizeConst is as big as your biggest possible string.

And you should probably read this: http://msdn.microsoft.com/en-us/library/4ca6d5z7.aspx

Translating touch events from Javascript to jQuery

jQuery 'fixes up' events to account for browser differences. When it does so, you can always access the 'native' event with event.originalEvent (see the Special Properties subheading on this page).

Save plot to image file instead of displaying it using Matplotlib

You can do it like this:

def plotAFig():
  plt.figure()
  plt.plot(x,y,'b-')
  plt.savefig("figurename.png")
  plt.close()

init-param and context-param

<init-param> will be used if you want to initialize some parameter for a particular servlet. When request come to servlet first its init method will be called then doGet/doPost whereas if you want to initialize some variable for whole application you will need to use <context-param> . Every servlet will have access to the context variable.

How can I encode a string to Base64 in Swift?

After all struggle I did like this.

func conversion(str:NSString)
{

    if let decodedData = NSData(base64EncodedString: str as String, options:NSDataBase64DecodingOptions(rawValue: 0)),
        let decodedString = NSString(data: decodedData, encoding: NSUTF8StringEncoding) {

        print(decodedString)//Here we are getting decoded string

After I am calling another function for converting decoded string to dictionary

        self .convertStringToDictionary(decodedString as String)
    }


}//function close

//for string to dictionary

func convertStringToDictionary(text: String) -> [String:AnyObject]? {
    if let data = text.dataUsingEncoding(NSUTF8StringEncoding) {
        do {
            let json = try NSJSONSerialization.JSONObjectWithData(data, options: []) as? [String:AnyObject]

            print(json)
            if let stack = json!["cid"]  //getting key value here
            {
                customerID = stack as! String
                print(customerID)
            }

        } catch let error as NSError {
            print(error)
        }
    }
    return nil
}

How to use the new Material Design Icon themes: Outlined, Rounded, Two-Tone and Sharp?

What worked for me is using _outline not _outlined after the icon name.

<mat-icon>info</mat-icon>

vs

<mat-icon>info_outline</mat-icon>

how to get current location in google map android

Simple steps to get current location on google map:

1 - create map activity so in onMap ready method you create LocationManager and LocationListener

2 - in onMap ready also you check for android version and user permission ==> if there is a permission give location update OR ask the user for permission

3 - in the main class check for result of permission (onRequestPermissionsResult) ==> if the condition is true so give location update

4 - in (onLocationChanged) method we create LatLng variable and get the coordinates from location then from mMap we (addMarker and moveCamera) for that variable we've just created, this gives us location when the user moves so we still need to create new LatLng in onMap ready to have user's location when the App starts ==>inside condition if there is permission (lastKnownLocation).

NOTE:

1) Do Not forget to ask for permissions (Location and Internet) in Manifest

2) Do Not forget to have Map key from google APIs

3) We used (mMap.clear) to avoid repeating the marker each time we (run the app or update location)

Coding Part:

public class MapsActivity extends FragmentActivity implements OnMapReadyCallback {

    private GoogleMap mMap;
    LocationManager locationManager;
    LocationListener locationListener;

    @Override
    public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
        super.onRequestPermissionsResult(requestCode, permissions, grantResults);

        if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
            if (ContextCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) == PackageManager.PERMISSION_GRANTED) {
                locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0, locationListener);
            }
        }
    }

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_maps);
        SupportMapFragment mapFragment = (SupportMapFragment) getSupportFragmentManager()
                .findFragmentById(R.id.map);
        mapFragment.getMapAsync(this);


    }

    @SuppressLint("MissingPermission")
    @Override
    public void onMapReady(GoogleMap googleMap) {
        mMap = googleMap;

        locationManager  = (LocationManager) this.getSystemService(Context.LOCATION_SERVICE);

        locationListener = new LocationListener() {
            @Override
            public void onLocationChanged(Location location) {

                mMap.clear();

                LatLng userLocation = new LatLng(location.getLatitude(), location.getLongitude());

                mMap.addMarker(new MarkerOptions().position(userLocation).title("Marker"));

                mMap.moveCamera(CameraUpdateFactory.newLatLng(userLocation));

                Toast.makeText(MapsActivity.this, userLocation.toString(), Toast.LENGTH_SHORT).show();
            }

            @Override
            public void onStatusChanged(String provider, int status, Bundle extras) {


            }

            @Override
            public void onProviderEnabled(String provider) {

            }

            @Override
            public void onProviderDisabled(String provider) {

            }


        };

        if (Build.VERSION.SDK_INT < 23 ){

            locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0, locationListener);

        }else if (ContextCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) == PackageManager.PERMISSION_GRANTED) {

            locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0, locationListener);

            Location lastKnownLocation = locationManager.getLastKnownLocation(LocationManager.GPS_PROVIDER);

            LatLng userLocation = new LatLng(lastKnownLocation.getLatitude(), lastKnownLocation.getLongitude());

            mMap.clear();

            mMap.addMarker(new MarkerOptions().position(userLocation).title("Marker"));

            mMap.moveCamera(CameraUpdateFactory.newLatLng(userLocation));

            Toast.makeText(MapsActivity.this, userLocation.toString(), Toast.LENGTH_SHORT).show();


        } else {

            ActivityCompat.requestPermissions(this, new String[]{Manifest.permission.ACCESS_FINE_LOCATION}, 1);

        }


    }


    }
}

Tracking changes in Windows registry

I concur with Franci, all Sysinternals utilities are worth taking a look (Autoruns is a must too), and Process Monitor, which replaces the good old Filemon and Regmon is precious.

Beside the usage you want, it is very useful to see why a process fails (like trying to access a file or a registry key that doesn't exist), etc.

invalid types 'int[int]' for array subscript

int myArray[10][10][10];

should be

int myArray[10][10][10][10];

Regular expression for excluding special characters

Do you really want to blacklist specific characters or rather whitelist the allowed charachters?

I assume that you actually want the latter. This is pretty simple (add any additional symbols to whitelist into the [\-] group):

^(?:\p{L}\p{M}*|[\-])*$

Edit: Optimized the pattern with the input from the comments

How to read barcodes with the camera on Android?

There are two parts in building barcode scanning feature, one capturing barcode image using camera and second extracting barcode value from the image.

Barcode image can be captured from your app using camera app and barcode value can be extracted using Firebase Machine Learning Kit barcode scanning API.

Here is an example app https://www.zoftino.com/android-barcode-scanning-example

Javascript/Jquery Convert string to array

check this out :)

var traingIds = "[1,2]";  // ${triningIdArray} this value getting from server 
alert(traingIds);  // alerts [1,2]
var type = typeof(traingIds);
alert(type);   // // alerts String

//remove square brackets
traingIds = traingIds.replace('[','');
traingIds = traingIds.replace(']','');
alert(traingIds);  // alerts 1,2        
var trainindIdArray = traingIds.split(',');

?for(i = 0; i< trainindIdArray.length; i++){
    alert(trainindIdArray[i]); //outputs individual numbers in array
    }? 

How can I get double quotes into a string literal?

Thankfully, with C++11 there is also the more pleasing approach of using raw string literals.

printf("She said \"time flies like an arrow, but fruit flies like a banana\".");

Becomes:

printf(R"(She said "time flies like an arrow, but fruit flies like a banana".)");

With respect to the addition of brackets after the opening quote, and before the closing quote, note that they can be almost any combination of up to 16 characters, helping avoid the situation where the combination is present in the string itself. Specifically:

any member of the basic source character set except: space, the left parenthesis (, the right parenthesis ), the backslash , and the control characters representing horizontal tab, vertical tab, form feed, and newline" (N3936 §2.14.5 [lex.string] grammar) and "at most 16 characters" (§2.14.5/2)

How much clearer it makes this short strings might be debatable, but when used on longer formatted strings like HTML or JSON, it's unquestionably far clearer.

How does Facebook Sharer select Images and other metadata when sharing my URL?

I had this problem and fixed it with manuel-84's suggestion. Using a 400x400px image worked great, while my smaller image never showed up in the sharer.

Note that Facebook recommends a minimum 200px square image as the og:image tag: https://developers.facebook.com/docs/opengraph/howtos/maximizing-distribution-media-content/#tags

What is Java String interning?

There are some "catchy interview" questions, such as why you get equals! if you execute the below piece of code.

String s1 = "testString";
String s2 = "testString";
if(s1 == s2) System.out.println("equals!");

If you want to compare Strings you should use equals(). The above will print equals because the testString is already interned for you by the compiler. You can intern the strings yourself using intern method as is shown in previous answers....

My eclipse won't open, i download the bundle pack it keeps saying error log

Make sure you have the prerequisite, a JVM (http://wiki.eclipse.org/Eclipse/Installation#Install_a_JVM) installed.

This will be a JRE and JDK package.

There are a number of sources which includes: http://www.oracle.com/technetwork/java/javase/downloads/index.html.

Android - Handle "Enter" in an EditText

editText.setOnEditorActionListener(new TextView.OnEditorActionListener() {
        @Override
        public boolean onEditorAction(TextView v, int actionId, KeyEvent event) {
            if (actionId != 0 || event.getAction() == KeyEvent.ACTION_DOWN) {
                // Action
                return true;
            } else {
                return false;
            }
        }
    });

Xml

<EditText
        android:id="@+id/editText2"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:hint="@string/password"
        android:imeOptions="actionGo|flagNoFullscreen"
        android:inputType="textPassword"
        android:maxLines="1" />

How can I bind to the change event of a textarea in jQuery?

This question needed a more up-to-date answer, with sources. This is what actually works (though you don't have to take my word for it):

// Storing this jQuery object outside of the event callback 
// prevents jQuery from having to search the DOM for it again
// every time an event is fired.
var $myButton = $("#buttonID")

// input           :: for all modern browsers [1]
// selectionchange :: for IE9 [2]
// propertychange  :: for <IE9 [3]
$('#textareaID').on('input selectionchange propertychange', function() {

  // This is the correct way to enable/disabled a button in jQuery [4]
  $myButton.prop('disabled', this.value.length === 0)

}

1: https://developer.mozilla.org/en-US/docs/Web/Events/input#Browser_compatibility
2: oninput in IE9 doesn't fire when we hit BACKSPACE / DEL / do CUT
3: https://msdn.microsoft.com/en-us/library/ms536956(v=vs.85).aspx
4: http://api.jquery.com/prop/#prop-propertyName-function

BUT, for a more global solution that you can use throughout your project, I recommend using the textchange jQuery plugin to gain a new, cross-browser compatible textchange event. It was developed by the same person who implemented the equivalent onChange event for Facebook's ReactJS, which they use for nearly their entire website. And I think it's safe to say, if it's a robust enough solution for Facebook, it's probably robust enough for you. :-)

UPDATE: If you happen to need features like drag and drop support in Internet Explorer, you may instead want to check out pandell's more recently updated fork of jquery-splendid-textchange.

How to split a dataframe string column into two columns?

Use df.assign to create a new df. See http://pandas.pydata.org/pandas-docs/stable/user_guide/indexing.html#returning-a-view-versus-a-copy

split = df_selected['name'].str.split(',', 1, expand=True)
df_split = df_selected.assign(first_name=split[0], last_name=split[1])
df_split.drop('name', 1, inplace=True)

How to encode URL to avoid special characters in Java?

If you don't want to do it manually use Apache Commons - Codec library. The class you are looking at is: org.apache.commons.codec.net.URLCodec

String final url = "http://www.google.com?...."
String final urlSafe = org.apache.commons.codec.net.URLCodec.encode(url);

Get current date/time in seconds

Date.now()-Math.floor(Date.now()/1000/60/60/24)*24*60*60*1000

This should give you the milliseconds from the beginning of the day.

(Date.now()-Math.floor(Date.now()/1000/60/60/24)*24*60*60*1000)/1000

This should give you seconds.

(Date.now()-(Date.now()/1000/60/60/24|0)*24*60*60*1000)/1000

Same as previous except uses a bitwise operator to floor the amount of days.

Launch custom android application from android browser

As of 15/06/2019

what I did is include all four possibilities to open url.

i.e, with http / https and 2 with www in prefix and 2 without www

and by using this my app launches automatically now without asking me to choose a browser and other option.

<intent-filter android:autoVerify="true">
    <action android:name="android.intent.action.VIEW" />
    <category android:name="android.intent.category.DEFAULT" />
    <category android:name="android.intent.category.BROWSABLE" />

    <data android:scheme="https" android:host="example.in" />
    <data android:scheme="https" android:host="www.example.in" />
    <data android:scheme="http" android:host="example.in" />
    <data android:scheme="http" android:host="www.example.in" />

</intent-filter>

Bootstrap 4 Dropdown Menu not working?

try to add these lines at the end of the file

<script src="https://code.jquery.com/jquery-3.2.1.slim.min.js" integrity="sha384-KJ3o2DKtIkvYIK3UENzmM7KCkRr/rE9/Qpg6aAZGJwFDMVNA/GpGFF93hXpG5KkN" crossorigin="anonymous"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.12.9/umd/popper.min.js" integrity="sha384-ApNbgh9B+Y1QKtv3Rn7W3mgPxhU9K/ScQsAP7hUibX39j7fakFPskvXusvfa0b4Q" crossorigin="anonymous"></script>
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0/js/bootstrap.min.js" integrity="sha384-JZR6Spejh4U02d8jOt6vLEHfe/JQGiRRSQQxSfFWpi1MquVdAyjUar5+76PVCmYl" crossorigin="anonymous"></script>
</body>
</html>

Add padding to HTML text input field

HTML

<div class="FieldElement"><input /></div>
<div class="searchIcon"><input type="submit" /></div>

For Other Browsers:

.FieldElement input {
width: 413px;
border:1px solid #ccc;
padding: 0 2.5em 0 0.5em;
}

.searchIcon
{
 background: url(searchicon-image-path) no-repeat;
 width: 17px;
 height: 17px;
 text-indent: -999em;
 display: inline-block;
 left: 432px;
 top: 9px;
}

For IE:

.FieldElement input {
width: 380px;
border:0;
}

.FieldElement {
 border:1px solid #ccc;
 width: 455px;     
 }

.searchIcon
{
 background: url(searchicon-image-path) no-repeat;
 width: 17px;
 height: 17px;
 text-indent: -999em;
 display: inline-block;
 left: 432px;
 top: 9px;
}

Check substring exists in a string in C

You can try this one for both finding the presence of the substring and to extract and print it:

#include <stdio.h>
#include <string.h>

int main(void)
{
    char mainstring[]="The quick brown fox jumps over the lazy dog";
    char substring[20], *ret;
    int i=0;
    puts("enter the sub string to find");
    fgets(substring, sizeof(substring), stdin);
    substring[strlen(substring)-1]='\0';
    ret=strstr(mainstring,substring);
    if(strcmp((ret=strstr(mainstring,substring)),substring))
    {
        printf("substring is present\t");
    }
    printf("and the sub string is:::");

    for(i=0;i<strlen(substring);i++)
    {
            printf("%c",*(ret+i));

    }
    puts("\n");
    return 0;
}

Is it possible to make an HTML anchor tag not clickable/linkable using CSS?

Yes.. It is possible using css

<a class="disable-me" href="page.html">page link</a>

.disable-me {
    pointer-events: none;
}

Failed to resolve version for org.apache.maven.archetypes

I too had same problem but after searching solved this. go to menu --> window-->preferences-->maven-->Installations-->add--> in place of installation home add path to the directory in which you installed maven-->finish-->check the box of newly added content-->apply-->ok. now create new maven project but remember try with different group id and artifact id.

How to find the array index with a value?

When the lists aren't extremely long, this is the best way I know:

function getIndex(val) {
    for (var i = 0; i < imageList.length; i++) {
        if (imageList[i] === val) {
            return i;
        }
    }
}

var imageList = [100, 200, 300, 400, 500];
var index = getIndex(200);

How to do case insensitive search in Vim

You can use in your vimrc those commands:

  • set ignorecase - All your searches will be case insensitive
  • set smartcase - Your search will be case sensitive if it contains an uppercase letter

You need to set ignorecase if you want to use what smartcase provides.

I wrote recently an article about Vim search commands (both built in command and the best plugins to search efficiently).

Calling a Fragment method from a parent Activity

Too late for the question but will post my answer anyway for anyone still needs it. I found an easier way to implement this, without using fragment id or fragment tag, since that's what I was seeking for.

First, I declared my Fragment in my ParentActivity class:

MyFragment myFragment;

Initialized my viewPager as usual, with the fragment I already added in the class above. Then, created a public method called scrollToTop in myFragment that does what I want to do from ParentActivity, let's say scroll my recyclerview to the top.

public void scrollToTop(){
    mMainRecyclerView.smoothScrollToPosition(0);
}

Now, in ParentActivity I called the method as below:

try{
   myFragment.scrollToTop();
}catch (Exception e){
   e.printStackTrace();
}

how to install gcc on windows 7 machine?

I use msysgit to install gcc on Windows, it has a nice installer which installs most everything that you might need. Most devs will need more than just the compiler, e.g. the shell, shell tools, make, git, svn, etc. msysgit comes with all of that. https://msysgit.github.io/

edit: I am now using msys2. Msys2 uses pacman from Arch Linux to install packages, and includes three environments, for building msys2 apps, 32-bit native apps, and 64-bit native apps. (You probably want to build 32-bit native apps.)

https://msys2.github.io/

You could also go full-monty and install code::blocks or some other gui editor that comes with a compiler. I prefer to use vim and make.

Android M - check runtime permission - how to determine if the user checked "Never ask again"?

Complete explanation for every case of permission

/**
 *    Case 1: User doesn't have permission
 *    Case 2: User has permission
 *
 *    Case 3: User has never seen the permission Dialog
 *    Case 4: User has denied permission once but he din't clicked on "Never Show again" check box
 *    Case 5: User denied the permission and also clicked on the "Never Show again" check box.
 *    Case 6: User has allowed the permission
 *
 */
public void handlePermission() {
    if (ContextCompat.checkSelfPermission(MainActivity.this,
            Manifest.permission.WRITE_EXTERNAL_STORAGE)
            != PackageManager.PERMISSION_GRANTED) {
        // This is Case 1. Now we need to check further if permission was shown before or not

        if (ActivityCompat.shouldShowRequestPermissionRationale(MainActivity.this,
                Manifest.permission.WRITE_EXTERNAL_STORAGE)) {

            // This is Case 4.
        } else {
            // This is Case 3. Request for permission here
        }

    } else {
        // This is Case 2. You have permission now you can do anything related to it
    }
}

public void onRequestPermissionsResult(int requestCode, String[] permissions, int[] grantResults) {

    if (grantResults[0] == PackageManager.PERMISSION_GRANTED) {
        // This is Case 2 (Permission is now granted)
    } else {
        // This is Case 1 again as Permission is not granted by user

        //Now further we check if used denied permanently or not
        if (ActivityCompat.shouldShowRequestPermissionRationale(MainActivity.this,
                Manifest.permission.WRITE_EXTERNAL_STORAGE)) {
            // case 4 User has denied permission but not permanently

        } else {
            // case 5. Permission denied permanently.
            // You can open Permission setting's page from here now.
        }

    }
}

Is Safari on iOS 6 caching $.ajax results?

It worked with ASP.NET only after adding the pragma:no-cache header in IIS. Cache-Control: no-cache was not enough.

angular2 manually firing click event on particular element

Angular4

Instead of

    this.renderer.invokeElementMethod(
        this.fileInput.nativeElement, 'dispatchEvent', [event]);

use

    this.fileInput.nativeElement.dispatchEvent(event);

because invokeElementMethod won't be part of the renderer anymore.

Angular2

Use ViewChild with a template variable to get a reference to the file input, then use the Renderer to invoke dispatchEvent to fire the event:

import { Component, Renderer, ElementRef, ViewChild } from '@angular/core';
@Component({
  ...
  template: `
...
<input #fileInput type="file" id="imgFile" (click)="onChange($event)" >
...`
})
class MyComponent {
  @ViewChild('fileInput') fileInput:ElementRef;

  constructor(private renderer:Renderer) {}

  showImageBrowseDlg() {
    // from http://stackoverflow.com/a/32010791/217408
    let event = new MouseEvent('click', {bubbles: true});
    this.renderer.invokeElementMethod(
        this.fileInput.nativeElement, 'dispatchEvent', [event]);
  }
}

Update

Since direct DOM access isn't discouraged anymore by the Angular team this simpler code can be used as well

this.fileInput.nativeElement.click()

See also https://developer.mozilla.org/en-US/docs/Web/API/EventTarget/dispatchEvent