Programs & Examples On #Rackspace

Rackspace US, Inc. (NYSE: RAX) is an IT hosting company based in San Antonio, Texas, USA.

Nginx no-www to www and www to no-www

try this

    if ($host !~* ^www\.){
        rewrite ^(.*)$ https://www.yoursite.com$1;
    }

Other way: Nginx no-www to www

server {
  listen       80;
  server_name  yoursite.com;
  root /path/;
  index index.php;
  return       301 https://www.yoursite.com$request_uri;
}

and www to no-www

server {
  listen       80;
  server_name  www.yoursite.com;
  root /path/;
  index index.php;
  return       301 https://yoursite.com$request_uri;
}

How to call Stored Procedure in a View?

You would have to script the View like below. You would essentially write the results of your proc to a table var or temp table, then select into the view.

Edit - If you can change your stored procedure to a Table Value function, it would eliminate the step of selecting to a temp table.

**Edit 2 ** - Comments are correct that a sproc cannot be read into a view like I suggested. Instead, convert your proc to a table-value function as mentioned in other posts and select from that:

create view sampleView
as select field1, field2, ... 
from dbo.MyTableValueFunction

I apologize for the confusion

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

As of the Windows 10 "Anniversary" update (Version 1607), you can now run an Ubuntu subsystem from directly inside of Windows by enabling a feature called Developer mode.

To enable developer mode, go to Start > Settings then typing "Use developer features" in the search box to find the setting. On the left hand navigation, you will then see a tab titled For developers. From within this tab, you will see a radio box to enable Developer mode.

After developer mode is enabled, you will then be able to enable the Linux subsystem feature. To do so, go to Control Panel > Programs > Turn Windows features on or off > and check the box that says Windows Subsystem for Linux (Beta)

Now, rather than using Cygwin or a console emulator, you can run tmux through bash on the Ubuntu subsystem directly from Windows through the traditional apt package (sudo apt-get install tmux).

Equivalent to AssemblyInfo in dotnet core/csproj

Adding to NightOwl888's answer, you can go one step further and add an AssemblyInfo class rather than just a plain class:

enter image description here

Pandas: Subtracting two date columns and the result being an integer

You can divide column of dtype timedelta by np.timedelta64(1, 'D'), but output is not int, but float, because NaN values:

df_test['Difference'] = df_test['Difference'] / np.timedelta64(1, 'D')
print (df_test)
  First_Date Second Date  Difference
0 2016-02-09  2015-11-19        82.0
1 2016-01-06  2015-11-30        37.0
2        NaT  2015-12-04         NaN
3 2016-01-06  2015-12-08        29.0
4        NaT  2015-12-09         NaN
5 2016-01-07  2015-12-11        27.0
6        NaT  2015-12-12         NaN
7        NaT  2015-12-14         NaN
8 2016-01-06  2015-12-14        23.0
9        NaT  2015-12-15         NaN

Frequency conversion.

React-Native Button style not work

The React Native Button is very limited in what you can do, see; Button

It does not have a style prop, and you don't set text the "web-way" like <Button>txt</Button> but via the title property <Button title="txt" />

If you want to have more control over the appearance you should use one of the TouchableXXXX' components like TouchableOpacity They are really easy to use :-)

Assigning a function to a variable

When you assign a function to a variable you don't use the () but simply the name of the function.

In your case given def x(): ..., and variable silly_var you would do something like this:

silly_var = x

and then you can call the function either with

x()

or

silly_var()

javax.net.ssl.SSLHandshakeException: java.security.cert.CertPathValidatorException: Trust anchor for certification path not found

This can happen for several reasons, including:

  1. The CA that issued the server certificate was unknown
  2. The server certificate wasn't signed by a CA, but was self signed
  3. The server configuration is missing an intermediate CA

please check out this link for solution: https://developer.android.com/training/articles/security-ssl.html#CommonProblems

Adding a library/JAR to an Eclipse Android project

First, the problem of the missing prefix.

If you consume something in your layout file that comes from a third party, you may need to consume its prefix as well, something like "droidfu:" which occurs in several places in the XML construct below:

<com.github.droidfu.widgets.WebImageView android:id="@+id/webimage"
          android:layout_width="75dip"
          android:layout_height="75dip"
          android:background="#CCC"
          droidfu:autoLoad="true"
          droidfu:imageUrl="http://www.android.com/images/opensourceprojec.gif"
          droidfu:progressDrawable="..."
          />

This comes out of the JAR, but you'll also need to add the new "xmlns:droidfu"

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
      xmlns:droidfu="http://github.com/droidfu/schema"
      ...>

or you get the unbound prefix error. For me, this was a failure to copy and paste all of the supplied example from the third-party library's pages.

Python; urllib error: AttributeError: 'bytes' object has no attribute 'read'

Use json.loads not json.load.

(load loads from a file-like object, loads from a string. So you could just as well omit the .read() call instead.)

Rollback to last git commit

If you want to just uncommit the last commit use this:

git reset HEAD~

work like charm for me.

ALTER TABLE on dependent column

If your constraint is on a user type, then don't forget to see if there is a Default Constraint, usually something like DF__TableName__ColumnName__6BAEFA67, if so then you will need to drop the Default Constraint, like this:

ALTER TABLE TableName DROP CONSTRAINT [DF__TableName__ColumnName__6BAEFA67]

For more info see the comments by the brilliant Aaron Bertrand on this answer.

Exact time measurement for performance testing

Stopwatch is fine, but loop the work 10^6 times, then divide by 10^6. You'll get a lot more precision.

What does [STAThread] do?

It tells the compiler that you're in a Single Thread Apartment model. This is an evil COM thing, it's usually used for Windows Forms (GUI's) as that uses Win32 for its drawing, which is implemented as STA. If you are using something that's STA model from multiple threads then you get corrupted objects.

This is why you have to invoke onto the Gui from another thread (if you've done any forms coding).

Basically don't worry about it, just accept that Windows GUI threads must be marked as STA otherwise weird stuff happens.

How To Set Text In An EditText

If you want to set text at design time in xml file just simple android:text="username" add this property.

<EditText
    android:id="@+id/edtUsername"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="username"/>

If you want to set text programmatically in Java

EditText edtUsername = findViewById(R.id.edtUsername);
edtUsername.setText("username");

and in kotlin same like java using getter/setter

edtUsername.setText("username")

But if you want to use .text from principle then

edtUsername.text = Editable.Factory.getInstance().newEditable("username")

because of EditText.text requires an editable at firstplace not String

Removing an element from an Array (Java)

Swap the item to be removed with the last item, if resizing the array down is not an interest.

How do you easily horizontally center a <div> using CSS?

I use div and span tags together with css properties such as block, cross-browser inline-block and text-align center, see my simple example

<!DOCTYPE html>
<html>
    <head>
       <title>Page Title</title>
       <style>
           .block{display:block;}
           .text-center{text-align:center;}
           .border-dashed-black{border:1px dashed black;}
           .inline-block{
                 display: -moz-inline-stack;
                 display: inline-block;
                 zoom: 1;
                 *display: inline;
            }
           .border-solid-black{border:1px solid black;}
           .text-left{text-align:left;}
        </style>
    </head>
    <body>
          <div class="block text-center border-dashed-black">
              <span class="block text-center">
                  <span class="block"> 
        <!-- The Div we want to center set any width as long as it is not more than the container-->
                      <div class="inline-block text-left border-solid-black" style="width:450px !important;">
                             jjjjjk
                      </div> 
                  </span>
              </span>
          </div>
      </body>
   </html>

How do I tell a Python script to use a particular version

put at the start of my programs its use full for work with python

import sys

if sys.version_info[0] < 3:
    raise Exception("Python 3 or a more recent version is required.")

This code will help full for the progress

What is meaning of negative dbm in signal strength?

At ms end Rx lev ranges 0 to -120 dbm Mean antenna power which received at ms end alway less than 1mW.

Thats why it always -ve.

Differences between cookies and sessions?

A cookie is simply a short text string that is sent back and forth between the client and the server. You could store name=bob; password=asdfas in a cookie and send that back and forth to identify the client on the server side. You could think of this as carrying on an exchange with a bank teller who has no short term memory, and needs you to identify yourself for each and every transaction. Of course using a cookie to store this kind information is horrible insecure. Cookies are also limited in size.

Now, when the bank teller knows about his/her memory problem, He/She can write down your information on a piece of paper and assign you a short id number. Then, instead of giving your account number and driver's license for each transaction, you can just say "I'm client 12"

Translating that to Web Servers: The server will store the pertinent information in the session object, and create a session ID which it will send back to the client in a cookie. When the client sends back the cookie, the server can simply look up the session object using the ID. So, if you delete the cookie, the session will be lost.

One other alternative is for the server to use URL rewriting to exchange the session id.

Suppose you had a link - www.myserver.com/myApp.jsp You could go through the page and rewrite every URL as www.myserver.com/myApp.jsp?sessionID=asdf or even www.myserver.com/asdf/myApp.jsp and exchange the identifier that way. This technique is handled by the web application container and is usually turned on by setting the configuration to use cookieless sessions.

What is the difference between Visual Studio Express 2013 for Windows and Visual Studio Express 2013 for Windows Desktop?

A comparison between the different Visual Studio Express editions can be found at Visual Studio Express (archive.org link). The difference between Windows and Windows Desktop is that with the Windows edition you can build Windows Store Apps (using .NET, WPF/XAML) while the Windows Desktop edition allows you to write classic Windows Desktop applications. It is possible to install both products on the same machine.

Visual Studio Express 2010 allows you to build Windows Desktop applications. Writing Windows Store applications is not possible with this product.

For learning I would suggest Notepad and the command line. While an IDE provides significant productivity enhancements to professionals, it can be intimidating to a beginner. If you want to use an IDE nevertheless I would recommend Visual Studio Express 2013 for Windows Desktop.


Update 2015-07-27: In addition to the Express Editions, Microsoft now offers Community Editions. These are still free for individual developers, open source contributors, and small teams. There are no Web, Windows, and Windows Desktop releases anymore either; the Community Edition can be used to develop any app type. In addition, the Community Edition does support (3rd party) Add-ins. The Community Edition offers the same functionality as the commercial Professional Edition.

How to unzip a list of tuples into individual lists?

Use zip(*list):

>>> l = [(1,2), (3,4), (8,9)]
>>> list(zip(*l))
[(1, 3, 8), (2, 4, 9)]

The zip() function pairs up the elements from all inputs, starting with the first values, then the second, etc. By using *l you apply all tuples in l as separate arguments to the zip() function, so zip() pairs up 1 with 3 with 8 first, then 2 with 4 and 9. Those happen to correspond nicely with the columns, or the transposition of l.

zip() produces tuples; if you must have mutable list objects, just map() the tuples to lists or use a list comprehension to produce a list of lists:

map(list, zip(*l))          # keep it a generator
[list(t) for t in zip(*l)]  # consume the zip generator into a list of lists

Make more than one chart in same IPython Notebook cell

Something like this:

import matplotlib.pyplot as plt
... code for plot 1 ...
plt.show()
... code for plot 2...
plt.show()

Note that this will also work if you are using the seaborn package for plotting:

import matplotlib.pyplot as plt
import seaborn as sns
sns.barplot(... code for plot 1 ...) # plot 1
plt.show()
sns.barplot(... code for plot 2 ...) # plot 2
plt.show()

java.util.MissingResourceException: Can't find bundle for base name 'property_file name', locale en_US

I'd like to share my experience of using Ant in building projects, *.properties files should be copied explicitly. This is because Ant will not compile *.properties files into the build working directory by default (javac just ignore *.properties). For example:

<target name="compile" depends="init">
    <javac destdir="${dst}" srcdir="${src}" debug="on" encoding="utf-8" includeantruntime="false">
        <include name="com/example/**" />
        <classpath refid="libs" />
    </javac>
    <copy todir="${dst}">
        <fileset dir="${src}" includes="**/*.properties" />
    </copy>
</target>

<target name="jars" depends="compile">
    <jar jarfile="${app_jar}" basedir="${dst}" includes="com/example/**/*.*" />
</target>

Please notice that 'copy' section under the 'compile' target, it will replicate *.properties files into the build working directory. Without the 'copy' section the jar file will not contain the properties files, then you may encounter the java.util.MissingResourceException.

IF EXISTS, THEN SELECT ELSE INSERT AND THEN SELECT

It sounds like your table has no key. You should be able to simply try the INSERT: if it’s a duplicate then the key constraint will bite and the INSERT will fail. No worries: you just need to ensure the application doesn't see/ignores the error. When you say 'primary key' you presumably mean IDENTITY value. That's all very well but you also need a key constraint (e.g. UNIQUE) on your natural key.

Also, I wonder whether your procedure is doing too much. Consider having separate procedures for 'create' and 'read' actions respectively.

__init__() got an unexpected keyword argument 'user'

You can't do

LivingRoom.objects.create(user=instance)

because you have an __init__ method that does NOT take user as argument.

You need something like

#signal function: if a user is created, add control livingroom to the user    
def create_control_livingroom(sender, instance, created, **kwargs):
    if created:
        my_room = LivingRoom()
        my_room.user = instance

Update

But, as bruno has already said it, Django's models.Model subclass's initializer is best left alone, or should accept *args and **kwargs matching the model's meta fields.

So, following better principles, you should probably have something like

class LivingRoom(models.Model):
    '''Living Room object'''
    user = models.OneToOneField(User)

    def __init__(self, *args, temp=65, **kwargs):
        self.temp = temp
        return super().__init__(*args, **kwargs)

Note - If you weren't using temp as a keyword argument, e.g. LivingRoom(65), then you'll have to start doing that. LivingRoom(user=instance, temp=66) or if you want the default (65), simply LivingRoom(user=instance) would do.

Convert string to date then format the date

enter image description here

String myFormat= "yyyy-MM-dd";
String finalString = "";
try {
DateFormat formatter = new SimpleDateFormat("yyyy MMM dd");
Date date = (Date) formatter .parse("2015 Oct 09");
SimpleDateFormat newFormat = new SimpleDateFormat(myFormat);
finalString= newFormat .format(date );
newDate.setText(finalString);
} catch (Exception e) {

}

How to access the php.ini file in godaddy shared hosting linux

For some hosting accounts, I'm on Ultimate Classic Linux, the file name you need to use is .user.ini.

Tomcat request timeout

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

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

Disable hover effects on mobile browsers

I take it from your question that your hover effect changes the content of your page. In that case, my advice is to:

  • Add hover effects on touchstart and mouseenter.
  • Remove hover effects on mouseleave, touchmove and click.

Alternatively, you can edit your page that there is no content change.

Background

In order to simulate a mouse, browsers such as Webkit mobile fire the following events if a user touches and releases a finger on touch screen (like iPad) (source: Touch And Mouse on html5rocks.com):

  1. touchstart
  2. touchmove
  3. touchend
  4. 300ms delay, where the browser makes sure this is a single tap, not a double tap
  5. mouseover
  6. mouseenter
    • Note: If a mouseover, mouseenter or mousemove event changes the page content, the following events are never fired.
  7. mousemove
  8. mousedown
  9. mouseup
  10. click

It does not seem possible to simply tell the webbrowser to skip the mouse events.

What's worse, if a mouseover event changes the page content, the click event is never fired, as explained on Safari Web Content Guide - Handling Events, in particular figure 6.4 in One-Finger Events. What exactly a "content change" is, will depend on browser and version. I've found that for iOS 7.0, a change in background color is not (or no longer?) a content change.

Solution Explained

To recap:

  • Add hover effects on touchstart and mouseenter.
  • Remove hover effects on mouseleave, touchmove and click.

Note that there is no action on touchend!

This clearly works for mouse events: mouseenter and mouseleave (slightly improved versions of mouseover and mouseout) are fired, and add and remove the hover.

If the user actually clicks a link, the hover effect is also removed. This ensure that it is removed if the user presses the back button in the web browser.

This also works for touch events: on touchstart the hover effect is added. It is '''not''' removed on touchend. It is added again on mouseenter, and since this causes no content changes (it was already added), the click event is also fired, and the link is followed without the need for the user to click again!

The 300ms delay that a browser has between a touchstart event and click is actually put in good use because the hover effect will be shown during this short time.

If the user decides to cancel the click, a move of the finger will do so just as normal. Normally, this is a problem since no mouseleave event is fired, and the hover effect remains in place. Thankfully, this can easily be fixed by removing the hover effect on touchmove.

That's it!

Note that it is possible to remove the 300ms delay, for example using the FastClick library, but this is out of scope for this question.

Alternative Solutions

I've found the following problems with the following alternatives:

  • browser detection: Extremely prone to errors. Assumes that a device has either mouse or touch, while a combination of both will become more and more common when touch displays prolifirate.
  • CSS media detection: The only CSS-only solution I'm aware of. Still prone to errors, and still assumes that a device has either mouse or touch, while both are possible.
  • Emulate the click event in touchend: This will incorrectly follow the link, even if the user only wanted to scroll or zoom, without the intention of actually clicking the link.
  • Use a variable to suppress mouse events: This set a variable in touchend that is used as a if-condition in subsequent mouse events to prevents state changes at that point in time. The variable is reset in the click event. See Walter Roman's answer on this page. This is a decent solution if you really don't want a hover effect on touch interfaces. Unfortunately, this does not work if a touchend is fired for another reason and no click event is fired (e.g. the user scrolled or zoomed), and is subsequently trying to following the link with a mouse (i.e on a device with both mouse and touch interface).

Further Reading

Python Accessing Nested JSON Data

I'm using this lib to access nested dict keys

https://github.com/mewwts/addict

 import requests
 from addict import Dict
 r = requests.get('http://api.zippopotam.us/us/ma/belmont')
 j = Dict(r.json())

 print j.state
 print j.places[1]['post code']  # only work with keys without '-', space, or starting with number 

How do I capture the output into a variable from an external process in PowerShell?

Have you tried:

$OutputVariable = (Shell command) | Out-String

Regular expression to extract text between square brackets

If someone wants to match and select a string containing one or more dots inside square brackets like "[fu.bar]" use the following:

(?<=\[)(\w+\.\w+.*?)(?=\])

Regex Tester

How to support placeholder attribute in IE8 and 9

I had compatibility issues with several plugins I tried, this seems to me to be the simplest way of supporting placeholders on text inputs:

function placeholders(){
    //On Focus
    $(":text").focus(function(){
        //Check to see if the user has modified the input, if not then remove the placeholder text
        if($(this).val() == $(this).attr("placeholder")){
            $(this).val("");
        }
    });

    //On Blur
    $(":text").blur(function(){
        //Check to see if the use has modified the input, if not then populate the placeholder back into the input
        if( $(this).val() == ""){
            $(this).val($(this).attr("placeholder"));
        }
    });
}

Input Type image submit form value?

Here is what I was trying to do and how I did it. I think you wanted to do something similar. I had a table with several rows and on each row I had an input with type image. I wanted to pass an id when the user clicked that image button. As you noticed the value in the tag is ignored. Instead I added a hidden input at the top of my table and using javascript I put the correct id there before I post the form.

<input type="image" onclick="$('#hiddenInput').val(rowId) src="...">

This way the correct id will be submitted with your form.

What is the standard Python docstring format?

It's Python; anything goes. Consider how to publish your documentation. Docstrings are invisible except to readers of your source code.

People really like to browse and search documentation on the web. To achieve that, use the documentation tool Sphinx. It's the de-facto standard for documenting Python projects. The product is beautiful - take a look at https://python-guide.readthedocs.org/en/latest/ . The website Read the Docs will host your docs for free.

Detect end of ScrollView

Did it!

Aside of the fix Alexandre kindly provide me, I had to create an Interface:

public interface ScrollViewListener {
    void onScrollChanged(ScrollViewExt scrollView, 
                         int x, int y, int oldx, int oldy);
}

Then, i had to override the OnScrollChanged method from ScrollView in my ScrollViewExt:

public class ScrollViewExt extends ScrollView {
    private ScrollViewListener scrollViewListener = null;
    public ScrollViewExt(Context context) {
        super(context);
    }

    public ScrollViewExt(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
    }

    public ScrollViewExt(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

    public void setScrollViewListener(ScrollViewListener scrollViewListener) {
        this.scrollViewListener = scrollViewListener;
    }

    @Override
    protected void onScrollChanged(int l, int t, int oldl, int oldt) {
        super.onScrollChanged(l, t, oldl, oldt);
        if (scrollViewListener != null) {
            scrollViewListener.onScrollChanged(this, l, t, oldl, oldt);
        }
    }
}

Now, as Alexandre said, put the package name in the XML tag (my fault), make my Activity class implement the interface created before, and then, put it all together:

scroll = (ScrollViewExt) findViewById(R.id.scrollView1);
scroll.setScrollViewListener(this);

And in the method OnScrollChanged, from the interface...

@Override
public void onScrollChanged(ScrollViewExt scrollView, int x, int y, int oldx, int oldy) {
    // We take the last son in the scrollview
    View view = (View) scrollView.getChildAt(scrollView.getChildCount() - 1);
    int diff = (view.getBottom() - (scrollView.getHeight() + scrollView.getScrollY()));

    // if diff is zero, then the bottom has been reached
    if (diff == 0) {
        // do stuff
    }
}

And it worked!

Thank you very much for your help, Alexandre!

R: how to label the x-axis of a boxplot

If you read the help file for ?boxplot, you'll see there is a names= parameter.

     boxplot(apple, banana, watermelon, names=c("apple","banana","watermelon"))

enter image description here

Showing percentages above bars on Excel column graph

Either

  1. Use a line series to show the %
  2. Update the data labels above the bars to link back directly to other cells

Method 2 by step

  • add data-lables
  • right-click the data lable
  • goto the edit bar and type in a refence to a cell (C4 in this example)
  • this changes the data lable from the defulat value (2000) to a linked cell with the 15%

enter image description here

Oracle to_date, from mm/dd/yyyy to dd-mm-yyyy

select to_char(to_date('1/21/2000','mm/dd/yyyy'),'dd-mm-yyyy') from dual

How to import other Python files?

There are many ways, as listed above, but I find that I just want to import he contents of a file, and don't want to have to write lines and lines and have to import other modules. So, I came up with a way to get the contents of a file, even with the dot syntax (file.property) as opposed to merging the imported file with yours.
First of all, here is my file which I'll import, data.py

    testString= "A string literal to import and test with"


Note: You could use the .txt extension instead.
In mainfile.py, start by opening and getting the contents.

    #!usr/bin/env python3
    Data=open('data.txt','r+').read()

Now you have the contents as a string, but trying to access data.testString will cause an error, as data is an instance of the str class, and even if it does have a property testString it will not do what you expected.
Next, create a class. For instance (pun intended), ImportedFile

    class ImportedFile:

And put this into it (with the appropriate indentation):

    exec(data)


And finally, re-assign data like so:

    data=ImportedFile()

And that's it! Just access like you would for any-other module, typing print(data.testString) will print to the console A string literal to import and test with.
If, however, you want the equivalent of from mod import * just drop the class, instance assignment, and de-dent the exec.

Hope this helps:)
-Benji

css overflow - only 1 line of text

the best code for UX and UI is

white-space: nowrap;
text-overflow: ellipsis;
overflow: hidden;
display: inherit;

How to Load an Assembly to AppDomain with all references recursively?

http://support.microsoft.com/kb/837908/en-us

C# version:

Create a moderator class and inherit it from MarshalByRefObject:

class ProxyDomain : MarshalByRefObject
{
    public Assembly GetAssembly(string assemblyPath)
    {
        try
        {
            return Assembly.LoadFrom(assemblyPath);
        }
        catch (Exception ex)
        {
            throw new InvalidOperationException(ex.Message);
        }
    }
}

call from client site

ProxyDomain pd = new ProxyDomain();
Assembly assembly = pd.GetAssembly(assemblyFilePath);

Reverse a string in Java

Take a look at the Java 6 API under StringBuffer

String s = "sample";
String result = new StringBuffer(s).reverse().toString();

create a trusted self-signed SSL cert for localhost (for use with Express/Node)

If you're using node, why not generate them with node? This module seems to be pretty full featured:

Note that I wouldn't generate on the fly. Generate with some kind of build script so you have a consistent certificate and key. Otherwise you'll have to authorize the newly generated self-signed certificate every time.

Grep and Python

Concise and memory efficient:

#!/usr/bin/env python
# file: grep.py
import re, sys

map(sys.stdout.write,(l for l in sys.stdin if re.search(sys.argv[1],l)))

It works like egrep (without too much error handling), e.g.:

cat input-file | grep.py "RE"

And here is the one-liner:

cat input-file | python -c "import re,sys;map(sys.stdout.write,(l for l in sys.stdin if re.search(sys.argv[1],l)))" "RE"

build maven project with propriatery libraries included

Create a new folder, let's say local-maven-repo at the root of your Maven project.

Just add a local repo iside your <project> of your pom.xml:

<repositories>
    <repository>
        <id>local-maven-repo</id>
        <url>file:///${project.basedir}/local-maven-repo</url>
    </repository>
</repositories>

Then for each external jar you want to install, go at the root of your project and execute:

mvn deploy:deploy-file -DgroupId=[GROUP] -DartifactId=[ARTIFACT] -Dversion=[VERS] -Durl=file:./local-maven-repo/ -DrepositoryId=local-maven-repo -DupdateReleaseInfo=true -Dfile=[FILE_PATH]

(Copied from my reply on a similar question)

How to show another window from mainwindow in QT

  1. Implement a slot in your QMainWindow where you will open your new Window,
  2. Place a widget on your QMainWindow,
  3. Connect a signal from this widget to a slot from the QMainWindow (for example: if the widget is a QPushButton connect the signal click() to the QMainWindow custom slot you have created).

Code example:

MainWindow.h

// ...
include "newwindow.h"
// ...
public slots:
   void openNewWindow();
// ...
private:
   NewWindow *mMyNewWindow;
// ...
}

MainWindow.cpp

// ...
   MainWindow::MainWindow()
   {
      // ...
      connect(mMyButton, SIGNAL(click()), this, SLOT(openNewWindow()));
      // ...
   }
// ...
void MainWindow::openNewWindow()
{
   mMyNewWindow = new NewWindow(); // Be sure to destroy your window somewhere
   mMyNewWindow->show();
   // ...
}

This is an example on how display a custom new window. There are a lot of ways to do this.

Links not going back a directory?

There are two type of paths: absolute and relative. This is basically the same for files in your hard disc and directories in a URL.

Absolute paths start with a leading slash. They always point to the same location, no matter where you use them:

  • /pages/en/faqs/faq-page1.html

Relative paths are the rest (all that do not start with slash). The location they point to depends on where you are using them

  • index.html is:
    • /pages/en/faqs/index.html if called from /pages/en/faqs/faq-page1.html
    • /pages/index.html if called from /pages/example.html
    • etc.

There are also two special directory names: . and ..:

  • . means "current directory"
  • .. means "parent directory"

You can use them to build relative paths:

  • ../index.html is /pages/en/index.html if called from /pages/en/faqs/faq-page1.html
  • ../../index.html is /pages/index.html if called from /pages/en/faqs/faq-page1.html

Once you're familiar with the terms, it's easy to understand what it's failing and how to fix it. You have two options:

  • Use absolute paths
  • Fix your relative paths

How to avoid Sql Query Timeout

While I would be tempted to blame my issues - I'm getting the same error with my query, which is much, much bigger and involves a lot of loops - on the network, I think this is not the case.

Unfortunately it's not that simple. Query runs for 3+ hours before getting that error and apparently it crashes at the same time if it's just a query in SSMS and a job on SQL Server (did not look into details of that yet, so not sure if it's the same error; definitely same spot, though).

So just in case someone comes here with similar problem, this thread: https://www.sqlservercentral.com/Forums/569962/The-semaphore-timeout-period-has-expired

suggest that it may equally well be a hardware issue or actual timeout.

My loops aren't even (they depend on sales level in given month) in terms of time required for each, so good month takes about 20 mins to calculate (query looks at 4 years).

That way it's entirely possible I need to optimise my query. I would even say it's likely, as some changes I did included new tables, which are heaps... So another round of indexing my data before tearing into VM config and hardware tests.

Being aware that this is old question: I'm on SQL Server 2012 SE, SSMS is 2018 Beta and VM the SQL Server runs on has exclusive use of 132GB of RAM (30% total), 8 cores, and 2TB of SSD SAN.

How can I delete all Git branches which have been merged?

I've been using the following method to remove merged local AND remote branches in one cmd.

I have the following in my bashrc file:

function rmb {
  current_branch=$(git branch --no-color 2> /dev/null | sed -e '/^[^*]/d' -e 's/* \(.*\)/\1/')
  if [ "$current_branch" != "master" ]; then
    echo "WARNING: You are on branch $current_branch, NOT master."
  fi
  echo "Fetching merged branches..."
  git remote prune origin
  remote_branches=$(git branch -r --merged | grep -v '/master$' | grep -v "/$current_branch$")
  local_branches=$(git branch --merged | grep -v 'master$' | grep -v "$current_branch$")
  if [ -z "$remote_branches" ] && [ -z "$local_branches" ]; then
    echo "No existing branches have been merged into $current_branch."
  else
    echo "This will remove the following branches:"
    if [ -n "$remote_branches" ]; then
      echo "$remote_branches"
    fi
    if [ -n "$local_branches" ]; then
      echo "$local_branches"
    fi
    read -p "Continue? (y/n): " -n 1 choice
    echo
    if [ "$choice" == "y" ] || [ "$choice" == "Y" ]; then
      # Remove remote branches
      git push origin `git branch -r --merged | grep -v '/master$' | grep -v "/$current_branch$" | sed 's/origin\//:/g' | tr -d '\n'`
      # Remove local branches
      git branch -d `git branch --merged | grep -v 'master$' | grep -v "$current_branch$" | sed 's/origin\///g' | tr -d '\n'`
    else
      echo "No branches removed."
    fi
  fi
}

original source

This doesn't delete the master branch, but removes merged local AND remote branches. Once you have this in you rc file, just run rmb, you're shown a list of merged branches that will be cleaned and asked for confirmation on the action. You can modify the code to not ask for confirmation as well, but it's probably good to keep it in.

How do you test to see if a double is equal to NaN?

The below code snippet will help evaluate primitive type holding NaN.

double dbl = Double.NaN; Double.valueOf(dbl).isNaN() ? true : false;

How to parse JSON with VBA without external libraries?

There are two issues here. The first is to access fields in the array returned by your JSON parse, the second is to rename collections/fields (like sentences) away from VBA reserved names.

Let's address the second concern first. You were on the right track. First, replace all instances of sentences with jsentences If text within your JSON also contains the word sentences, then figure out a way to make the replacement unique, such as using "sentences":[ as the search string. You can use the VBA Replace method to do this.

Once that's done, so VBA will stop renaming sentences to Sentences, it's just a matter of accessing the array like so:

'first, declare the variables you need:
Dim jsent as Variant

'Get arr all setup, then
For Each jsent in arr.jsentences
  MsgBox(jsent.orig)
Next

Pandas: ValueError: cannot convert float NaN to integer

if you have null value then in doing mathematical operation you will get this error to resolve it use df[~df['x'].isnull()]df[['x']].astype(int) if you want your dataset to be unchangeable.

Counting Line Numbers in Eclipse

Under linux, the simpler is:

  1. go to the root folder of your project
  2. use find to do a recursive search of *.java files
  3. use wc -l to count lines:

To resume, just do:

find . -name '*.java' | xargs wc -l    

How to display raw html code in PRE or something like it but without escaping it

Cheap and cheerful answer:

<textarea>Some raw content</textarea>

The textarea will handle tabs, multiple spaces, newlines, line wrapping all verbatim. It copies and pastes nicely and its valid HTML all the way. It also allows the user to resize the code box. You don't need any CSS, JS, escaping, encoding.

You can alter the appearance and behaviour as well. Here's a monospace font, editing disabled, smaller font, no border:

<textarea
    style="width:100%; font-family: Monospace; font-size:10px; border:0;"
    rows="30" disabled
>Some raw content</textarea>

This solution is probably not semantically correct. So if you need that, it might be best to choose a more sophisticated answer.

find vs find_by vs where

where returns ActiveRecord::Relation

Now take a look at find_by implementation:

def find_by
  where(*args).take
end

As you can see find_by is the same as where but it returns only one record. This method should be used for getting 1 record and where should be used for getting all records with some conditions.

How to find integer array size in java

public class Test {

    int[] array = { 1, 99, 10000, 84849, 111, 212, 314, 21, 442, 455, 244, 554,
            22, 22, 211 };

    public void Printrange() {

        for (int i = 0; i < array.length; i++) { // <-- use array.length 
            if (array[i] > 100 && array[i] < 500) {
                System.out.println("numbers with in range :" + array[i]);
            }
        }
    }
}

Accessing a class' member variables in Python?

Implement the return statement like the example below! You should be good. I hope it helps someone..

class Example(object):
    def the_example(self):
        itsProblem = "problem"
        return itsProblem 


theExample = Example()
print theExample.the_example()

SHA512 vs. Blowfish and Bcrypt

Blowfish is not a hashing algorithm. It's an encryption algorithm. What that means is that you can encrypt something using blowfish, and then later on you can decrypt it back to plain text.

SHA512 is a hashing algorithm. That means that (in theory) once you hash the input you can't get the original input back again.

They're 2 different things, designed to be used for different tasks. There is no 'correct' answer to "is blowfish better than SHA512?" You might as well ask "are apples better than kangaroos?"

If you want to read some more on the topic here's some links:

Efficient way to insert a number into a sorted array of numbers?

function insertOrdered(array, elem) {
    let _array = array;
    let i = 0;
    while ( i < array.length && array[i] < elem ) {i ++};
    _array.splice(i, 0, elem);
    return _array;
}

HTTP status code 0 - Error Domain=NSURLErrorDomain?

Status code '0' can occur because of three reasons
1) The Client cannot connect to the server
2) The Client cannot receive the response within the timeout period
3) The Request was "stopped(aborted)" by the Client.

But these three reasons are not standardized

How to parse JSON in Scala using standard Scala classes?

I tried a few things, favouring pattern matching as a way of avoiding casting but ran into trouble with type erasure on the collection types.

The main problem seems to be that the complete type of the parse result mirrors the structure of the JSON data and is either cumbersome or impossible to fully state. I guess that is why Any is used to truncate the type definitions. Using Any leads to the need for casting.

I've hacked something below which is concise but is extremely specific to the JSON data implied by the code in the question. Something more general would be more satisfactory but I'm not sure if it would be very elegant.

implicit def any2string(a: Any)  = a.toString
implicit def any2boolean(a: Any) = a.asInstanceOf[Boolean]
implicit def any2double(a: Any)  = a.asInstanceOf[Double]

case class Language(name: String, isActive: Boolean, completeness: Double)

val languages = JSON.parseFull(jstr) match {
  case Some(x) => {
    val m = x.asInstanceOf[Map[String, List[Map[String, Any]]]]

    m("languages") map {l => Language(l("name"), l("isActive"), l("completeness"))}
  }
  case None => Nil
}

languages foreach {println}

Differences between CHMOD 755 vs 750 permissions set

0755 = User:rwx Group:r-x World:r-x

0750 = User:rwx Group:r-x World:--- (i.e. World: no access)

r = read
w = write
x = execute (traverse for directories)

How do I vertically align text in a paragraph?

Try these styles:

_x000D_
_x000D_
p.event_desc {_x000D_
  font: bold 12px "Helvetica Neue", Helvetica, Arial, sans-serif;_x000D_
  line-height: 14px;_x000D_
  height:75px;_x000D_
  margin: 0px;_x000D_
  display: table-cell;_x000D_
  vertical-align: middle;_x000D_
  padding: 10px;_x000D_
  border: 1px solid #f00;_x000D_
}
_x000D_
<p class="event_desc">lorem ipsum</p>
_x000D_
_x000D_
_x000D_

How can I move all the files from one folder to another using the command line?

move c:\sourcefolder c:\targetfolder

will work, but you will end up with a structure like this:

c:\targetfolder\sourcefolder\[all the subfolders & files]

If you want to move just the contents of one folder to another, then this should do it:

SET src_folder=c:\srcfold
SET tar_folder=c:\tarfold

for /f %%a IN ('dir "%src_folder%" /b') do move "%src_folder%\%%a" "%tar_folder%\"

pause

Spring Security with roles and permissions

The basic steps are:

  1. Use a custom authentication provider

    <bean id="myAuthenticationProvider" class="myProviderImplementation" scope="singleton">
    ...
    </bean>
    

  2. Make your custom provider return a custom UserDetails implementation. This UserDetailsImpl will have a getAuthorities() like this:

    public Collection<GrantedAuthority> getAuthorities() {
        List<GrantedAuthority> permissions = new ArrayList<GrantedAuthority>();
        for (GrantedAuthority role: roles) {
            permissions.addAll(getPermissionsIncludedInRole(role));
        }
        return permissions;
    }
    

Of course from here you could apply a lot of optimizations/customizations for your specific requirements.

Apply vs transform on a group object

you can use zscore to analyze the data in column C and D for outliers, where zscore is the series - series.mean / series.std(). Use apply too create a user defined function for difference between C and D creating a new resulting dataframe. Apply uses the group result set.

from scipy.stats import zscore

columns = ['A', 'B', 'C', 'D']
records = [
['foo', 'one', 0.162003, 0.087469],
['bar', 'one', -1.156319, -1.5262719999999999],
['foo', 'two', 0.833892, -1.666304],     
['bar', 'three', -2.026673, -0.32205700000000004],
['foo', 'two', 0.41145200000000004, -0.9543709999999999],
['bar', 'two', 0.765878, -0.095968],
['foo', 'one', -0.65489, 0.678091],
['foo', 'three', -1.789842, -1.130922]
]
df = pd.DataFrame.from_records(records, columns=columns)
print(df)

standardize=df.groupby('A')['C','D'].transform(zscore)
print(standardize)
outliersC= (standardize['C'] <-1.1) | (standardize['C']>1.1)
outliersD= (standardize['D'] <-1.1) | (standardize['D']>1.1)

results=df[outliersC | outliersD]
print(results)

   #Dataframe results
   A      B         C         D
   0  foo    one  0.162003  0.087469
   1  bar    one -1.156319 -1.526272
   2  foo    two  0.833892 -1.666304
   3  bar  three -2.026673 -0.322057
   4  foo    two  0.411452 -0.954371
   5  bar    two  0.765878 -0.095968
   6  foo    one -0.654890  0.678091
   7  foo  three -1.789842 -1.130922
 #C and D transformed Z score
           C         D
 0  0.398046  0.801292
 1 -0.300518 -1.398845
 2  1.121882 -1.251188
 3 -1.046514  0.519353
 4  0.666781 -0.417997
 5  1.347032  0.879491
 6 -0.482004  1.492511
 7 -1.704704 -0.624618

 #filtering using arbitrary ranges -1 and 1 for the z-score
      A      B         C         D
 1  bar    one -1.156319 -1.526272
 2  foo    two  0.833892 -1.666304
 5  bar    two  0.765878 -0.095968
 6  foo    one -0.654890  0.678091
 7  foo  three -1.789842 -1.130922


 >>>>>>>>>>>>> Part 2

 splitting = df.groupby('A')

 #look at how the data is grouped
 for group_name, group in splitting:
     print(group_name)

 def column_difference(gr):
      return gr['C']-gr['D']

 grouped=splitting.apply(column_difference)
 print(grouped)

 A     
 bar  1    0.369953
      3   -1.704616
      5    0.861846
 foo  0    0.074534
      2    2.500196
      4    1.365823
      6   -1.332981
      7   -0.658920

Sum one number to every element in a list (or array) in Python

if you want to operate with list of numbers it is better to use NumPy arrays:

import numpy
a = [1, 1, 1 ,1, 1]
ar = numpy.array(a)
print ar + 2

gives

[3, 3, 3, 3, 3]

Javascript, viewing [object HTMLInputElement]

<input type="text" />
<script>
$("input:text").change(function() {
    var value=$("input:text").val();
    alert(value);
});
</script>

use .val() to get value of the element (jquery method), $("input:text") this selector to select your input, .change() to bind an event handler to the "change" JavaScript event.

How to vertically center a container in Bootstrap?

for bootstrap4 vertical center of few items

d-flex for flex rules

flex-column for vertical direction on items

justify-content-center for centering

style='height: 300px;' must have for set points where center be calc or use h-100 class

then for horizontal center div d-flex justify-content-center and some container

so we have hierarhy of 3 tag: div-column -> div-row -> div-container

     <div class="d-flex flex-column justify-content-center bg-secondary" 
        style="height: 300px;">
        <div class="d-flex justify-content-center">
           <div class=bg-primary>Flex item</div>
        </div>
        <div class="d-flex justify-content-center">
           <div class=bg-primary>Flex item</div>
        </div>
      </div> 

How do I solve this error, "error while trying to deserialize parameter"

I have a solution for this but not sure on the reason why this would be different from one environment to the other - although one big difference between the two environments is WSS svc pack 1 was installed on the environment where the error was occurring.

To fix this issue I got a good clue from this link - http://silverlight.net/forums/t/22787.aspx ie to "please check the Xml Schema of your service" and "the sequence in the schema is sorted alphabetically"

Looking at the wsdl generated I noticed that for the serialized class that was causing the error, the properties of this class were not visible in the wsdl.

The Definition of the class had private setters for most of the properties, but not for CustomFields property ie..

[Serializable]
public class FileMetaDataDto
{
    .
    . a constructor...   etc and several other properties edited for brevity
    . 

    public int Id { get; private set; }
    public string Version { get; private set; }
    public List<MetaDataValueDto> CustomFields { get; set; }

}

On removing private from the setter and redeploying the service then looking at the wsdl again, these properties were now visible, and the original error was fixed.

So the wsdl before update was

- <s:complexType name="ArrayOfFileMetaDataDto">
- <s:sequence>
  <s:element minOccurs="0" maxOccurs="unbounded" name="FileMetaDataDto" nillable="true" type="tns:FileMetaDataDto" /> 
  </s:sequence>
  </s:complexType>
- <s:complexType name="FileMetaDataDto">
- <s:sequence>
  <s:element minOccurs="0" maxOccurs="1" name="CustomFields" type="tns:ArrayOfMetaDataValueDto" /> 
  </s:sequence>
  </s:complexType>

The wsdl after update was

- <s:complexType name="ArrayOfFileMetaDataDto">
- <s:sequence>
  <s:element minOccurs="0" maxOccurs="unbounded" name="FileMetaDataDto" nillable="true" type="tns:FileMetaDataDto" /> 
  </s:sequence>
  </s:complexType>
- <s:complexType name="FileMetaDataDto">
- <s:sequence>
  <s:element minOccurs="1" maxOccurs="1" name="Id" type="s:int" /> 
  <s:element minOccurs="0" maxOccurs="1" name="Name" type="s:string" /> 
  <s:element minOccurs="0" maxOccurs="1" name="Title" type="s:string" /> 
  <s:element minOccurs="0" maxOccurs="1" name="ContentType" type="s:string" /> 
  <s:element minOccurs="0" maxOccurs="1" name="Icon" type="s:string" /> 
  <s:element minOccurs="0" maxOccurs="1" name="ModifiedBy" type="s:string" /> 
  <s:element minOccurs="1" maxOccurs="1" name="ModifiedDateTime" type="s:dateTime" /> 
  <s:element minOccurs="1" maxOccurs="1" name="FileSizeBytes" type="s:int" /> 
  <s:element minOccurs="0" maxOccurs="1" name="Url" type="s:string" /> 
  <s:element minOccurs="0" maxOccurs="1" name="RelativeFolderPath" type="s:string" /> 
  <s:element minOccurs="0" maxOccurs="1" name="DisplayVersion" type="s:string" /> 
  <s:element minOccurs="0" maxOccurs="1" name="Version" type="s:string" /> 
  <s:element minOccurs="0" maxOccurs="1" name="CustomFields" type="tns:ArrayOfMetaDataValueDto" /> 
  <s:element minOccurs="0" maxOccurs="1" name="CheckoutBy" type="s:string" /> 
  </s:sequence>
  </s:complexType>

How to get the timezone offset in GMT(Like GMT+7:00) from android device?

You can do like this:

    TimeZone tz = TimeZone.getDefault();
    int offset = tz.getRawOffset();

    String timeZone = String.format("%s%02d%02d", offset >= 0 ? "+" : "-", offset / 3600000, (offset / 60000) % 60);

How do I pass parameters into a PHP script through a webpage?

$argv[0]; // the script name
$argv[1]; // the first parameter
$argv[2]; // the second parameter

If you want to all the script to run regardless of where you call it from (command line or from the browser) you'll want something like the following:

<?php
if ($_GET) {
    $argument1 = $_GET['argument1'];
    $argument2 = $_GET['argument2'];
} else {
    $argument1 = $argv[1];
    $argument2 = $argv[2];
}
?>

To call from command line chmod 755 /var/www/webroot/index.php and use

/usr/bin/php /var/www/webroot/index.php arg1 arg2

To call from the browser, use

http://www.mydomain.com/index.php?argument1=arg1&argument2=arg2

How to create custom button in Android using XML Styles

Two things you need to do, if you want to make a custom button design.

1st is: create a xml resource file in drawable folder (Example: btn_shape_rectangle.xml) then copy and paste the code there.

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
android:padding="16dp"
android:shape="rectangle">
<solid
    android:color="#fff"/>
<stroke
    android:width="1dp"
    android:color="#000000"
    />
<corners android:radius="10dp" />
</shape>

2nd is go to your layout button where you want to implement this design. just link up it. Example: android:background="@drawable/btn_shape_rectangle"

You can change shape color radius what design you want can do.

Hope it will works and help you. Happy Coding

How do I convert a Django QuerySet into list of dicts?

You could define a function using model_to_dict as follows:

def queryset_to_list(qs,fields=None, exclude=None):
    my_list=[]
    for x in qs:
        my_list.append(model_to_dict(x,fields=fields,exclude=exclude))
    return my_list

Suppose your Model has following fields

id
name
email

Run following commands in django shell

>>>qs=<yourmodel>.objects.all()
>>>list=queryset_to_dict(qs)
>>>list
[{'id':1, 'name':'abc', 'email':'[email protected]'},{'id':2, 'name':'xyz', 'email':'[email protected]'}]

Say you want only id and name in the list of queryset dictionary

>>>qs=<yourmodel>.objects.all()
>>>list=queryset_to_dict(qs,fields=['id','name'])
>>>list
[{'id':1, 'name':'abc'},{'id':2, 'name':'xyz'}]

Similarly you can exclude fields in your output.

Assigning variables with dynamic names in Java

If you want to access the variables some sort of dynamic you may use reflection. However Reflection works not for local variables. It is only applyable for class attributes.

A rough quick and dirty example is this:

public class T {
    public Integer n1;
    public Integer n2;
    public Integer n3;

    public void accessAttributes() throws IllegalArgumentException, SecurityException, IllegalAccessException,
            NoSuchFieldException {

        for (int i = 1; i < 4; i++) {
            T.class.getField("n" + i).set(this, 5);
        }
    }
}

You need to improve this code in various ways it is only an example. This is also not considered to be good code.

Android screen size HDPI, LDPI, MDPI

You should read Supporting multiple screens. You must define dpi on your emulator. 240 is hdpi, 160 is mdpi and below that are usually ldpi.

Extract from Android Developer Guide link above:

320dp: a typical phone screen (240x320 ldpi, 320x480 mdpi, 480x800 hdpi, etc).  
480dp: a tweener tablet like the Streak (480x800 mdpi).  
600dp: a 7” tablet (600x1024 mdpi).  
720dp: a 10” tablet (720x1280 mdpi, 800x1280 mdpi, etc).

Join/Where with LINQ and Lambda

I find that if you're familiar with SQL syntax, using the LINQ query syntax is much clearer, more natural, and makes it easier to spot errors:

var id = 1;
var query =
   from post in database.Posts
   join meta in database.Post_Metas on post.ID equals meta.Post_ID
   where post.ID == id
   select new { Post = post, Meta = meta };

If you're really stuck on using lambdas though, your syntax is quite a bit off. Here's the same query, using the LINQ extension methods:

var id = 1;
var query = database.Posts    // your starting point - table in the "from" statement
   .Join(database.Post_Metas, // the source table of the inner join
      post => post.ID,        // Select the primary key (the first part of the "on" clause in an sql "join" statement)
      meta => meta.Post_ID,   // Select the foreign key (the second part of the "on" clause)
      (post, meta) => new { Post = post, Meta = meta }) // selection
   .Where(postAndMeta => postAndMeta.Post.ID == id);    // where statement

Do I need to pass the full path of a file in another directory to open()?

Here's a snippet that will walk the file tree for you:

indir = '/home/des/test'
for root, dirs, filenames in os.walk(indir):
    for f in filenames:
        print(f)
        log = open(indir + f, 'r')

Get elements by attribute when querySelectorAll is not available without using libraries?

Try this it works

document.querySelector('[attribute="value"]')

example :

document.querySelector('[role="button"]')

How to set a bitmap from resource

Try this

This is from sdcard

ImageView image = (ImageView) findViewById(R.id.test_image);
Bitmap bMap = BitmapFactory.decodeFile("/sdcard/test2.png");
image.setImageBitmap(bMap);

This is from resources

Bitmap bMap = BitmapFactory.decodeResource(getResources(), R.drawable.icon);

How do you create vectors with specific intervals in R?

Use the code

x = seq(0,100,5) #this means (starting number, ending number, interval)

the output will be

[1]   0   5  10  15  20  25  30  35  40  45  50  55  60  65  70  75
[17]  80  85  90  95 100

How to turn off magic quotes on shared hosting?

As per the manual you can often install a custom php.ini on shared hosting, where mod_php isn't used and the php_value directive thus leads to an error. For suexec/FastCGI setups it is quite common to have a per-webspace php.ini in any case.

--

I don't think O (uppercase letter o) is a valid value to set an ini flag. You need to use a true/false, 1/0, or "on"/"off" value.

ini_set( 'magic_quotes_gpc', 0 );   // doesn't work

EDIT

After checking the list of ini settings, I see that magic_quotes_gpc is a PHP_INI_PERDIR setting (after 4.2.3), which means you can't change it with ini_set() (only PHP_INI_ALL settings can be changed with ini_set())

What this means is you have to use an .htaccess file to do this - OR - implement a script to reverse the effects of magic quotes. Something like this

if ( in_array( strtolower( ini_get( 'magic_quotes_gpc' ) ), array( '1', 'on' ) ) )
{
    $_POST = array_map( 'stripslashes', $_POST );
    $_GET = array_map( 'stripslashes', $_GET );
    $_COOKIE = array_map( 'stripslashes', $_COOKIE );
}

In Mongoose, how do I sort by date? (node.js)

ES6 solution with Koa.

  async recent() {
    data = await ReadSchema.find({}, { sort: 'created_at' });
    ctx.body = data;
  }

How can I assign the output of a function to a variable using bash?

VAR=$(scan)

Exactly the same way as for programs.

Creating hard and soft links using PowerShell

Actually, the Sysinternals junction command only works with directories (don't ask me why), so it can't hardlink files. I would go with cmd /c mklink for soft links (I can't figure why it's not supported directly by PowerShell), or fsutil for hardlinks.

If you need it to work on Windows XP, I do not know of anything other than Sysinternals junction, so you might be limited to directories.

run main class of Maven project

Try the maven-exec-plugin. From there:

mvn exec:java -Dexec.mainClass="com.example.Main"

This will run your class in the JVM. You can use -Dexec.args="arg0 arg1" to pass arguments.

If you're on Windows, apply quotes for exec.mainClass and exec.args:

mvn exec:java -D"exec.mainClass"="com.example.Main"

If you're doing this regularly, you can add the parameters into the pom.xml as well:

<plugin>
  <groupId>org.codehaus.mojo</groupId>
  <artifactId>exec-maven-plugin</artifactId>
  <version>1.2.1</version>
  <executions>
    <execution>
      <goals>
        <goal>java</goal>
      </goals>
    </execution>
  </executions>
  <configuration>
    <mainClass>com.example.Main</mainClass>
    <arguments>
      <argument>foo</argument>
      <argument>bar</argument>
    </arguments>
  </configuration>
</plugin>

How to synchronize or lock upon variables in Java?

From Java 1.5 it's always a good Idea to consider java.util.concurrent package. They are the state of the art locking mechanism in java right now. The synchronize mechanism is more heavyweight that the java.util.concurrent classes.

The example would look something like this:

import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReentrantLock;

public class Sample {

    private final Lock lock = new ReentrantLock();

    private String message = null;

    public void newmsg(String msg) {
        lock.lock();
        try {
            message = msg;
        } finally {
            lock.unlock();
        }
    }

    public String getmsg() {
        lock.lock();
        try {
            String temp = message;
            message = null;
            return temp;
        } finally {
            lock.unlock();
        }
    }
}

Checking if a variable is an integer in PHP

Just for kicks, I tested out a few of the mentioned methods, plus one I've used as my go to solution for years when I know my input is a positive number or string equivalent.

I tested this with 125,000 iterations, with each iteration passing in the same set of variable types and values.

Method 1: is_int($value) || ctype_digit($value)
Method 2: (string)(int)$value == (string)$value
Method 3: strval(intval($value)) === strval($value)
Method 4: ctype_digit(strval($value))
Method 5: filter_var($value, FILTER_VALIDATE_INT) !== FALSE
Method 6: is_int($value) || ctype_digit($value) || (is_string($value) && $value[0] === '-' && filter_var($value, FILTER_VALIDATE_INT) !== FALSE)

Method 1: 0.0552167892456
Method 2: 0.126773834229
Method 3: 0.143012046814
Method 4: 0.0979189872742
Method 5: 0.112988948822
Method 6: 0.0858821868896

(I didn't even test the regex, I mean, seriously... regex for this?)

Things to note:
Method 4 always returns false for negative numbers (negative integer or string equivalent), so is a good method to consistently detect that a value is a positive integer.
Method 1 returns true for a negative integer, but false for a string equivalent of a negative integer, so don't use this method unless you are certain your input will never contain a negative number in string or integer form, and that if it does, your process won't break from this behavior.

Conclusions
So it seems that if you are certain that your input will not include a negative number, then it is almost twice as fast to use is_int and ctype_digit to validate that you have an integer. Using Method 1 with a fallback to method 5 when the variable is a string and the first character is a dash is the next fastest (especially when a majority of the input is actual integers or positive numbers in a string). All in all, if you need solid consistency, and you have no idea what the mix of data is coming in, and you must handle negatives in a consistent fashion, filter_var($value, FILTER_VALIDATE_INT) !== FALSE wins.

Code used to get the output above:

$u = "-10";
$v = "0";
$w = 0;
$x = "5";
$y = "5c";
$z = 1.44;

function is_int1($value){
    return (is_int($value) || ctype_digit($value));
}

function is_int2($value) {
    return ((string)(int)$value == (string)$value);
}

function is_int3($value) {
    return (strval(intval($value)) === strval($value));
}

function is_int4($value) {
    return (ctype_digit(strval($value)));
}

function is_int5($value) {
    return filter_var($value, FILTER_VALIDATE_INT) !== FALSE;
}

function is_int6($value){
    return (is_int($value) || ctype_digit($value) || (is_string($value) && $value[0] === '-' && filter_var($value, FILTER_VALIDATE_INT)) !== FALSE);
}

$start = microtime(TRUE);
for ($i=0; $i < 125000; $i++) {
  is_int1($u);
  is_int1($v);
  is_int1($w);
  is_int1($x);
  is_int1($y);
  is_int1($z);
}
$stop = microtime(TRUE);
$start2 = microtime(TRUE);
for ($j=0; $j < 125000; $j++) {
  is_int2($u);
  is_int2($v);
  is_int2($w);
  is_int2($x);
  is_int2($y);
  is_int2($z);
}
$stop2 = microtime(TRUE);
$start3 = microtime(TRUE);
for ($k=0; $k < 125000; $k++) {
  is_int3($u);
  is_int3($v);
  is_int3($w);
  is_int3($x);
  is_int3($y);
  is_int3($z);
}
$stop3 = microtime(TRUE);
$start4 = microtime(TRUE);
for ($l=0; $l < 125000; $l++) {
  is_int4($u);
  is_int4($v);
  is_int4($w);
  is_int4($x);
  is_int4($y);
  is_int4($z);
}
$stop4 = microtime(TRUE); 

$start5 = microtime(TRUE);
for ($m=0; $m < 125000; $m++) {
  is_int5($u);
  is_int5($v);
  is_int5($w);
  is_int5($x);
  is_int5($y);
  is_int5($z);
}
$stop5 = microtime(TRUE); 

$start6 = microtime(TRUE);
for ($n=0; $n < 125000; $n++) {
  is_int6($u);
  is_int6($v);
  is_int6($w);
  is_int6($x);
  is_int6($y);
  is_int6($z);
}
$stop6 = microtime(TRUE); 

$time = $stop - $start;  
$time2 = $stop2 - $start2;  
$time3 = $stop3 - $start3;  
$time4 = $stop4 - $start4;  
$time5 = $stop5 - $start5;  
$time6 = $stop6 - $start6;  
print "**Method 1:** $time <br>";
print "**Method 2:** $time2 <br>";
print "**Method 3:** $time3 <br>";
print "**Method 4:** $time4 <br>";  
print "**Method 5:** $time5 <br>";  
print "**Method 6:** $time6 <br>";  

What is the difference between char array and char pointer in C?

For cases like this, the effect is the same: You end up passing the address of the first character in a string of characters.

The declarations are obviously not the same though.

The following sets aside memory for a string and also a character pointer, and then initializes the pointer to point to the first character in the string.

char *p = "hello";

While the following sets aside memory just for the string. So it can actually use less memory.

char p[10] = "hello";

How to finish current activity in Android

What I was doing was starting a new activity and then closing the current activity. So, remember this simple rule:

finish()
startActivity<...>()

and not

startActivity<...>()
finish()

How do you get a string from a MemoryStream?

use a StreamReader, then you can use the ReadToEnd method that returns a string.

Double decimal formatting in Java

There are many way you can do this. Those are given bellow:

Suppose your original number is given bellow:

 double number = 2354548.235;

Using NumberFormat:

NumberFormat formatter = new DecimalFormat("#0.00");
    System.out.println(formatter.format(number));

Using String.format:

System.out.println(String.format("%,.2f", number));

Using DecimalFormat and pattern:

NumberFormat nf = DecimalFormat.getInstance(Locale.ENGLISH);
        DecimalFormat decimalFormatter = (DecimalFormat) nf;
        decimalFormatter.applyPattern("#,###,###.##");
        String fString = decimalFormatter.format(number);
        System.out.println(fString);

Using DecimalFormat and pattern

DecimalFormat decimalFormat = new DecimalFormat("############.##");
        BigDecimal formattedOutput = new BigDecimal(decimalFormat.format(number));
        System.out.println(formattedOutput);

In all cases the output will be: 2354548.23

Note:

During rounding you can add RoundingMode in your formatter. Here are some rounding mode given bellow:

    decimalFormat.setRoundingMode(RoundingMode.CEILING);
    decimalFormat.setRoundingMode(RoundingMode.FLOOR);
    decimalFormat.setRoundingMode(RoundingMode.HALF_DOWN);
    decimalFormat.setRoundingMode(RoundingMode.HALF_UP);
    decimalFormat.setRoundingMode(RoundingMode.UP);

Here are the imports:

import java.math.BigDecimal;
import java.math.RoundingMode;
import java.text.DecimalFormat;
import java.text.NumberFormat;
import java.util.Locale;

Android "elevation" not showing a shadow

If you are adding elevation to a button element, you need to add the following line:

android:stateListAnimator="@null"

See Android 5.0 android:elevation Works for View, but not Button?

Disable button in WPF?

I know this isn't as elegant as the other posts, but it's a more straightforward xaml/codebehind example of how to accomplish the same thing.

Xaml:

<StackPanel Orientation="Horizontal">
   <TextBox Name="TextBox01" VerticalAlignment="Top" HorizontalAlignment="Left" Width="70" />
   <Button Name="Button01" VerticalAlignment="Top" HorizontalAlignment="Left" Margin="10,0,0,0" />
</StackPanel>

CodeBehind:

Private Sub Window1_Loaded(ByVal sender As Object, ByVal e As System.Windows.RoutedEventArgs) Handles Me.Loaded

        Button01.IsEnabled = False
        Button01.Content = "I am Disabled"

End Sub

Private Sub TextBox01_TextChanged(ByVal sender As Object, ByVal e As System.Windows.Controls.TextChangedEventArgs) Handles TextBox01.TextChanged

        If TextBox01.Text.Trim.Length > 0 Then
            Button01.IsEnabled = True
            Button01.Content = "I am Enabled"
        Else
            Button01.IsEnabled = False
            Button01.Content = "I am Disabled"
        End If

End Sub

How to easily resize/optimize an image size with iOS?

I developed an ultimate solution for image scaling in Swift.

You can use it to resize image to fill, aspect fill or aspect fit specified size.

You can align image to center or any of four edges and four corners.

And also you can trim extra space which is added if aspect ratios of original image and target size are not equal.

enum UIImageAlignment {
    case Center, Left, Top, Right, Bottom, TopLeft, BottomRight, BottomLeft, TopRight
}

enum UIImageScaleMode {
    case Fill,
    AspectFill,
    AspectFit(UIImageAlignment)
}

extension UIImage {
    func scaleImage(width width: CGFloat? = nil, height: CGFloat? = nil, scaleMode: UIImageScaleMode = .AspectFit(.Center), trim: Bool = false) -> UIImage {
        let preWidthScale = width.map { $0 / size.width }
        let preHeightScale = height.map { $0 / size.height }
        var widthScale = preWidthScale ?? preHeightScale ?? 1
        var heightScale = preHeightScale ?? widthScale
        switch scaleMode {
        case .AspectFit(_):
            let scale = min(widthScale, heightScale)
            widthScale = scale
            heightScale = scale
        case .AspectFill:
            let scale = max(widthScale, heightScale)
            widthScale = scale
            heightScale = scale
        default:
            break
        }
        let newWidth = size.width * widthScale
        let newHeight = size.height * heightScale
        let canvasWidth = trim ? newWidth : (width ?? newWidth)
        let canvasHeight = trim ? newHeight : (height ?? newHeight)
        UIGraphicsBeginImageContextWithOptions(CGSizeMake(canvasWidth, canvasHeight), false, 0)

        var originX: CGFloat = 0
        var originY: CGFloat = 0
        switch scaleMode {
        case .AspectFit(let alignment):
            switch alignment {
            case .Center:
                originX = (canvasWidth - newWidth) / 2
                originY = (canvasHeight - newHeight) / 2
            case .Top:
                originX = (canvasWidth - newWidth) / 2
            case .Left:
                originY = (canvasHeight - newHeight) / 2
            case .Bottom:
                originX = (canvasWidth - newWidth) / 2
                originY = canvasHeight - newHeight
            case .Right:
                originX = canvasWidth - newWidth
                originY = (canvasHeight - newHeight) / 2
            case .TopLeft:
                break
            case .TopRight:
                originX = canvasWidth - newWidth
            case .BottomLeft:
                originY = canvasHeight - newHeight
            case .BottomRight:
                originX = canvasWidth - newWidth
                originY = canvasHeight - newHeight
            }
        default:
            break
        }
        self.drawInRect(CGRectMake(originX, originY, newWidth, newHeight))
        let image = UIGraphicsGetImageFromCurrentImageContext()
        UIGraphicsEndImageContext()
        return image
    }
}

There are examples of applying this solution below.

Gray rectangle is target site image will be resized to. Blue circles in light blue rectangle is the image (I used circles because it's easy to see when it's scaled without preserving aspect). Light orange color marks areas that will be trimmed if you pass trim: true.

Aspect fit before and after scaling:

Aspect fit 1 (before) Aspect fit 1 (after)

Another example of aspect fit:

Aspect fit 2 (before) Aspect fit 2 (after)

Aspect fit with top alignment:

Aspect fit 3 (before) Aspect fit 3 (after)

Aspect fill:

Aspect fill (before) Aspect fill (after)

Fill:

Fill (before) Fill (after)

I used upscaling in my examples because it's simpler to demonstrate but solution also works for downscaling as in question.

For JPEG compression you should use this :

let compressionQuality: CGFloat = 0.75 // adjust to change JPEG quality
if let data = UIImageJPEGRepresentation(image, compressionQuality) {
  // ...
}

You can check out my gist with Xcode playground.

How can I tell if a Java integer is null?

Try this:

Integer startIn = null;

try {
  startIn = Integer.valueOf(startField.getText());
} catch (NumberFormatException e) {
  .
  .
  .
}

if (startIn == null) {
  // Prompt for value...
}

How to change facebook login button with my custom image

It is actually possible only using CSS, however, the image you use to replace must be the same size as the original facebook log in button. Fortunately Facebook delivers the button in different sizes.

From facebook:

size - Different sized buttons: small, medium, large, xlarge - the default is medium. https://developers.facebook.com/docs/reference/plugins/login/

Set the login iframe opacity to 0 and show a background image in the parent div

.fb_iframe_widget iframe {
    opacity: 0;
}

.fb_iframe_widget {
  background-image: url(another-button.png);
  background-repeat: no-repeat; 
}

If you use an image that is bigger than the original facebook button, the part of the image that is outside the width and height of the original button will not be clickable.

Can't find out where does a node.js app running and can't kill it

List node process:

$ ps -e|grep node

Kill the process using

$kill -9 XXXX

Here XXXX is the process number

Generate an integer sequence in MySQL

You appear to be able to construct reasonably large sets with:

select 9 union all select 10 union all select 11 union all select 12 union all select 13 ...

I got a parser stack overflow in the 5300's, on 5.0.51a.

Set the table column width constant regardless of the amount of text in its cells?

You don't need to set "fixed" - all you need is setting overflow:hidden since the column width is set.

How to export non-exportable private key from store

This worked for me on Windows Server 2012 - I needed to export a non-exportable certificate to setup another ADFS server and this did the trick. Remember to use the jailbreak instructions above i.e.:

crypto::certificates /export /systemstore:CERT_SYSTEM_STORE_LOCAL_MACHINE

Is header('Content-Type:text/plain'); necessary at all?

no its not like that,here is Example for the support of my answer ---->the clear difference is visible ,when you go for HTTP Compression,which allows you to compress the data while travelling from Server to Client and the Type of this data automatically becomes as "gzip" which Tells browser that bowser got a zipped data and it has to upzip it,this is a example where Type really matters at Bowser.

functional way to iterate over range (ES6/7)

One can create an empty array, fill it (otherwise map will skip it) and then map indexes to values:

Array(8).fill().map((_, i) => i * i);

Remove special symbols and extra spaces and replace with underscore using the replace method

var str = "hello world & hello universe"

In order to replace both Spaces and Symbols in one shot, we can use the below regex code.

str.replaceAll("\\W+","")

Note: \W -> represents Not Words (includes spaces/special characters) | + -> one or many matches

Try it!

How to use external ".js" files

I hope this helps someone here: I encountered an issue where I needed to use JavaScript to manipulate some dynamically generated elements. After including the code to my external .js file which I had referenced to between the <script> </script> tags at the head section and it was working perfectly, nothing worked again from the script.Tried using developer tool on FF and it returned null value for the variable holding the new element. I decided to move my script tag to the bottom of the html file just before the </body> tag and bingo every part of the script started to respond fine again.

Differences between "BEGIN RSA PRIVATE KEY" and "BEGIN PRIVATE KEY"

See https://polarssl.org/kb/cryptography/asn1-key-structures-in-der-and-pem (search the page for "BEGIN RSA PRIVATE KEY") (archive link for posterity, just in case).

BEGIN RSA PRIVATE KEY is PKCS#1 and is just an RSA key. It is essentially just the key object from PKCS#8, but without the version or algorithm identifier in front. BEGIN PRIVATE KEY is PKCS#8 and indicates that the key type is included in the key data itself. From the link:

The unencrypted PKCS#8 encoded data starts and ends with the tags:

-----BEGIN PRIVATE KEY-----
BASE64 ENCODED DATA
-----END PRIVATE KEY-----

Within the base64 encoded data the following DER structure is present:

PrivateKeyInfo ::= SEQUENCE {
  version         Version,
  algorithm       AlgorithmIdentifier,
  PrivateKey      BIT STRING
}

AlgorithmIdentifier ::= SEQUENCE {
  algorithm       OBJECT IDENTIFIER,
  parameters      ANY DEFINED BY algorithm OPTIONAL
}

So for an RSA private key, the OID is 1.2.840.113549.1.1.1 and there is a RSAPrivateKey as the PrivateKey key data bitstring.

As opposed to BEGIN RSA PRIVATE KEY, which always specifies an RSA key and therefore doesn't include a key type OID. BEGIN RSA PRIVATE KEY is PKCS#1:

RSA Private Key file (PKCS#1)

The RSA private key PEM file is specific for RSA keys.

It starts and ends with the tags:

-----BEGIN RSA PRIVATE KEY-----
BASE64 ENCODED DATA
-----END RSA PRIVATE KEY-----

Within the base64 encoded data the following DER structure is present:

RSAPrivateKey ::= SEQUENCE {
  version           Version,
  modulus           INTEGER,  -- n
  publicExponent    INTEGER,  -- e
  privateExponent   INTEGER,  -- d
  prime1            INTEGER,  -- p
  prime2            INTEGER,  -- q
  exponent1         INTEGER,  -- d mod (p-1)
  exponent2         INTEGER,  -- d mod (q-1)
  coefficient       INTEGER,  -- (inverse of q) mod p
  otherPrimeInfos   OtherPrimeInfos OPTIONAL
}

JSP : JSTL's <c:out> tag

As said Will Wagner, in old version of jsp you should always use c:out to output dynamic text.

Moreover, using this syntax:

<c:out value="${person.name}">No name</c:out>

you can display the text "No name" when name is null.

The simplest possible JavaScript countdown timer?

If you want a real timer you need to use the date object.

Calculate the difference.

Format your string.

window.onload=function(){
      var start=Date.now(),r=document.getElementById('r');
      (function f(){
      var diff=Date.now()-start,ns=(((3e5-diff)/1e3)>>0),m=(ns/60)>>0,s=ns-m*60;
      r.textContent="Registration closes in "+m+':'+((''+s).length>1?'':'0')+s;
      if(diff>3e5){
         start=Date.now()
      }
      setTimeout(f,1e3);
      })();
}

Example

Jsfiddle

not so precise timer

var time=5*60,r=document.getElementById('r'),tmp=time;

setInterval(function(){
    var c=tmp--,m=(c/60)>>0,s=(c-m*60)+'';
    r.textContent='Registration closes in '+m+':'+(s.length>1?'':'0')+s
    tmp!=0||(tmp=time);
},1000);

JsFiddle

html table span entire width?

<table border="1"; width=100%>

works for me.

adding multiple event listeners to one element

For large numbers of events this might help:

var element = document.getElementById("myId");
var myEvents = "click touchstart touchend".split(" ");
var handler = function (e) {
    do something
};

for (var i=0, len = myEvents.length; i < len; i++) {
    element.addEventListener(myEvents[i], handler, false);
}

Update 06/2017:

Now that new language features are more widely available you could simplify adding a limited list of events that share one listener.

const element = document.querySelector("#myId");

function handleEvent(e) {
    // do something
}
// I prefer string.split because it makes editing the event list slightly easier

"click touchstart touchend touchmove".split(" ")
    .map(name => element.addEventListener(name, handleEvent, false));

If you want to handle lots of events and have different requirements per listener you can also pass an object which most people tend to forget.

const el = document.querySelector("#myId");

const eventHandler = {
    // called for each event on this element
    handleEvent(evt) {
        switch (evt.type) {
            case "click":
            case "touchstart":
                // click and touchstart share click handler
                this.handleClick(e);
                break;
            case "touchend":
                this.handleTouchend(e);
                break;
            default:
                this.handleDefault(e);
        }
    },
    handleClick(e) {
        // do something
    },
    handleTouchend(e) {
        // do something different
    },
    handleDefault(e) {
        console.log("unhandled event: %s", e.type);
    }
}

el.addEventListener(eventHandler);

Update 05/2019:

const el = document.querySelector("#myId");

const eventHandler = {
    handlers: {
        click(e) {
            // do something
        },
        touchend(e) {
            // do something different
        },
        default(e) {
            console.log("unhandled event: %s", e.type);
        }
    },
    // called for each event on this element
    handleEvent(evt) {
        switch (evt.type) {
            case "click":
            case "touchstart":
                // click and touchstart share click handler
                this.handlers.click(e);
                break;
            case "touchend":
                this.handlers.touchend(e);
                break;
            default:
                this.handlers.default(e);
        }
    }
}

Object.keys(eventHandler.handlers)
    .map(eventName => el.addEventListener(eventName, eventHandler))

AngularJS disable partial caching on dev machine

Here is another option in Chrome.

Hit F12 to open developer tools. Then Resources > Cache Storage > Refresh Caches.

enter image description here

I like this option because I don't have to disable cache as in other answers.

MySQL foreach alternative for procedure

Here's the mysql reference for cursors. So I'm guessing it's something like this:

  DECLARE done INT DEFAULT 0;
  DECLARE products_id INT;
  DECLARE result varchar(4000);
  DECLARE cur1 CURSOR FOR SELECT products_id FROM sets_products WHERE set_id = 1;
  DECLARE CONTINUE HANDLER FOR NOT FOUND SET done = 1;

  OPEN cur1;

  REPEAT
    FETCH cur1 INTO products_id;
    IF NOT done THEN
      CALL generate_parameter_list(@product_id, @result);
      SET param = param + "," + result; -- not sure on this syntax
    END IF;
  UNTIL done END REPEAT;

  CLOSE cur1;

  -- now trim off the trailing , if desired

IntelliJ, can't start simple web application: Unable to ping server at localhost:1099

I added the following VM Options and it worked for me:

-Dcom.sun.management.jmxremote= 
-Dcom.sun.management.jmxremote.port=1099 
-Dcom.sun.management.jmxremote.authenticate=false 
-Dcom.sun.management.jmxremote.ssl=false

How can I delete (not disable) ActiveX add-ons in Internet Explorer (7 and 8 Beta 2)?

You could unregister the control with

regsvr32 /u badboy.ocx

at the command line. Though i would suggest testing these things in a vmware.

Create an enum with string values

I think you should try with this, in this case the value of the variable won't change and it works quite like enums,using like a class also works the only disadvantage is by mistake you can change the value of static variable and that's what we don't want in enums.

namespace portal {

export namespace storageNames {

    export const appRegistration = 'appRegistration';
    export const accessToken = 'access_token';

  }
}

ORACLE and TRIGGERS (inserted, updated, deleted)

From Using Triggers:

Detecting the DML Operation That Fired a Trigger

If more than one type of DML operation can fire a trigger (for example, ON INSERT OR DELETE OR UPDATE OF Emp_tab), the trigger body can use the conditional predicates INSERTING, DELETING, and UPDATING to check which type of statement fire the trigger.

So

IF DELETING THEN ... END IF;

should work for your case.

JavaScript: Object Rename Key

You could wrap the work in a function and assign it to the Object prototype. Maybe use the fluent interface style to make multiple renames flow.

Object.prototype.renameProperty = function (oldName, newName) {
     // Do nothing if the names are the same
     if (oldName === newName) {
         return this;
     }
    // Check for the old property name to avoid a ReferenceError in strict mode.
    if (this.hasOwnProperty(oldName)) {
        this[newName] = this[oldName];
        delete this[oldName];
    }
    return this;
};

ECMAScript 5 Specific

I wish the syntax wasn't this complex but it is definitely nice having more control.

Object.defineProperty(
    Object.prototype, 
    'renameProperty',
    {
        writable : false, // Cannot alter this property
        enumerable : false, // Will not show up in a for-in loop.
        configurable : false, // Cannot be deleted via the delete operator
        value : function (oldName, newName) {
            // Do nothing if the names are the same
            if (oldName === newName) {
                return this;
            }
            // Check for the old property name to 
            // avoid a ReferenceError in strict mode.
            if (this.hasOwnProperty(oldName)) {
                this[newName] = this[oldName];
                delete this[oldName];
            }
            return this;
        }
    }
);

Case Statement Equivalent in R

i dont like any of these, they are not clear to the reader or the potential user. I just use an anonymous function, the syntax is not as slick as a case statement, but the evaluation is similar to a case statement and not that painful. this also assumes your evaluating it within where your variables are defined.

result <- ( function() { if (x==10 | y< 5) return('foo') 
                         if (x==11 & y== 5) return('bar')
                        })()

all of those () are necessary to enclose and evaluate the anonymous function.

Create folder in Android

If you are trying to make more than just one folder on the root of the sdcard, ex. Environment.getExternalStorageDirectory() + "/Example/Ex App/"

then instead of folder.mkdir() you would use folder.mkdirs()

I've made this mistake in the past & I took forever to figure it out.

'No JUnit tests found' in Eclipse

The best way to resolve this issue is to put public Access modifier for your Junit Test Case class name and then run the scenario by right click on your Junit test case class and run as Junit Test.

Exclude all transitive dependencies of a single dependency

Use the latest maven in your classpath.. It will remove the duplicate artifacts and keep the latest maven artifact..

No resource found that matches the given name: attr 'android:keyboardNavigationCluster'. when updating to Support Library 26.0.0

I solved this problem by doing the following:

compileSdkVersion 26
buildToolsVersion "26.0.1"

compile 'com.android.support:appcompat-v7:26.0.1'
compile 'com.android.support:design:26.0.1'
compile 'com.android.support:cardview-v7:26.0.1'
compile 'com.android.support:recyclerview-v7:26.0.1'

Count number of occurrences by month

Make column B in sheet1 the dates but where the day of the month is always the first day of the month, e.g. in B2 put =DATE(YEAR(A2),MONTH(A2),1). Then make E5 on sheet 2 contain the first date of the month you need, e.g. Date(2013,4,1). After that, putting in F5 COUNTIF(Sheet1!B2:B50, E5) will give you the count for the month specified in E5.

Amazon S3 - HTTPS/SSL - Is it possible?

payton109’s answer is correct if you’re in the default US-EAST-1 region. If your bucket is in a different region, use a slightly different URL:

https://s3-<region>.amazonaws.com/your.domain.com/some/asset

Where <region> is the bucket location name. For example, if your bucket is in the us-west-2 (Oregon) region, you can do this:

https://s3-us-west-2.amazonaws.com/your.domain.com/some/asset

pdftk compression option

this procedure works pretty well

pdf2ps large.pdf very_large.ps

ps2pdf very_large.ps small.pdf

give it a try.

json and empty array

"location" : null // this is not really an array it's a null object
"location" : []   // this is an empty array

It looks like this API returns null when there is no location defined - instead of returning an empty array, not too unusual really - but they should tell you if they're going to do this.

Static linking vs dynamic linking

Static linking includes the files that the program needs in a single executable file.

Dynamic linking is what you would consider the usual, it makes an executable that still requires DLLs and such to be in the same directory (or the DLLs could be in the system folder).

(DLL = dynamic link library)

Dynamically linked executables are compiled faster and aren't as resource-heavy.

remove white space from the end of line in linux

sed -i 's/[[:blank:]]\{1,\}$//' YourFile

[:blank:] is for space, tab mainly and {1,} to exclude 'no space at the end' of the substitution process (no big significant impact if line are short and file are small)

XAMPP Object not found error

Drixson Oseña you are right but when you newly install xampp on your system "Object not found!

"The requested URL was not found on this server. If you entered the URL manually please check your spelling and try again. If you think this is a server error, please contact the webmaster. Error 404 localhost Apache/2.4.7 (Win32) OpenSSL/1.0.1e PHP/5.5.6"

However all folder in the htdocs but only open is that xampp website because of index.php error, so that's not a big deal just remove the index.html and index.php and try to open localhost again you'll be succeed.

vector vs. list in STL

Well the students of my class seems quite unable to explain to me when it is more effective to use vectors, but they look quite happy when advising me to use lists.

This is how I understand it

Lists: Each item contains an address to the next or previous element, so with this feature, you can randomize the items, even if they aren't sorted, the order won't change: it's efficient if you memory is fragmented. But it also has an other very big advantage: you can easily insert/remove items, because the only thing you need to do is change some pointers. Drawback: To read a random single item, you have to jump from one item to another until you find the correct address.

Vectors: When using vectors, the memory is much more organized like regular arrays: each n-th items is stored just after (n-1)th item and before (n+1)th item. Why is it better than list ? Because it allow fast random access. Here is how: if you know the size of an item in a vector, and if they are contiguous in memory, you can easily predict where the n-th item is; you don't have to browse all the item of a list to read the one you want, with vector, you directly read it, with a list you can't. On the other hand, modify the vector array or change a value is much more slow.

Lists are more appropriate to keep track of objects which can be added/removed in memory. Vectors are more appropriate when you want to access an element from a big quantity of single items.

I don't know how lists are optimized, but you have to know that if you want fast read access, you should use vectors, because how good the STL fasten lists, it won't be as fast in read-access than vector.

Spring cron expression for every after 30 minutes

According to the Quartz-Scheduler Tutorial It should be value="0 0/30 * * * ?"

The field order of the cronExpression is

1.Seconds

2.Minutes

3.Hours

4.Day-of-Month

5.Month

6.Day-of-Week

7.Year (optional field)

Ensure you have at least 6 parameters or you will get an error (year is optional)

How to include libraries in Visual Studio 2012?

In code level also, you could add your lib to the project using the compiler directives #pragma.

example:

#pragma comment( lib, "yourLibrary.lib" )

How to convert int to date in SQL Server 2008

Reading through this helps solve a similar problem. The data is in decimal datatype - [DOB] [decimal](8, 0) NOT NULL - eg - 19700109. I want to get at the month. The solution is to combine SUBSTRING with CONVERT to VARCHAR.

    SELECT [NUM]
       ,SUBSTRING(CONVERT(VARCHAR, DOB),5,2) AS mob
    FROM [Dbname].[dbo].[Tablename] 

Example to use shared_ptr?

Through Boost you can do it >

std::vector<boost::any> vecobj;
    boost::shared_ptr<string> sharedString1(new string("abcdxyz!"));    
    boost::shared_ptr<int> sharedint1(new int(10));
    vecobj.push_back(sharedString1);
    vecobj.push_back(sharedint1);

> for inserting different object type in your vector container. while for accessing you have to use any_cast, which works like dynamic_cast, hopes it will work for your need.

How do I get current URL in Selenium Webdriver 2 Python?

Another way to do it would be to inspect the url bar in chrome to find the id of the element, have your WebDriver click that element, and then send the keys you use to copy and paste using the keys common function from selenium, and then printing it out or storing it as a variable, etc.

React component not re-rendering on state change

I was going through same issue in React-Native where API response & reject weren't updating states

apiCall().then(function(resp) { this.setState({data: resp}) // wasn't updating }

I solved the problem by changing function with the arrow function

apiCall().then((resp) => {
    this.setState({data: resp}) // rendering the view as expected
}

For me, it was a binding issue. Using arrow functions solved it because arrow function doesn't create its's own this, its always bounded to its outer context where it comes from

Getting binary (base64) data from HTML5 Canvas (readAsBinaryString)

Short answer:

const base64Canvas = canvas.toDataURL("image/jpeg").split(';base64,')[1];

How to establish ssh key pair when "Host key verification failed"

Task Passwordless authentication for suer.

Error : Host key verification failed.

Source :10.13.1.11 Target : 10.13.1.35

Temporary workaround :

[user@server~]$ ssh [email protected] The authenticity of host '10.13.1.35 (10.13.1.35)' can't be established. RSA key fingerprint is b8:ba:30:46:a9:ab:70:12:1a:f2:f1:61:69:73:0a:19. Are you sure you want to continue connecting (yes/no)? yes Warning: Permanently added '10.13.1.35' (RSA) to the list of known hosts.

Try to authenticate user again...it will work.

RegEx for Javascript to allow only alphanumeric

/^[a-z0-9]+$/i

^         Start of string
[a-z0-9]  a or b or c or ... z or 0 or 1 or ... 9
+         one or more times (change to * to allow empty string)
$         end of string    
/i        case-insensitive

Update (supporting universal characters)

if you need to this regexp supports universal character you can find list of unicode characters here.

for example: /^([a-zA-Z0-9\u0600-\u06FF\u0660-\u0669\u06F0-\u06F9 _.-]+)$/

this will support persian.

Copy multiple files from one directory to another from Linux shell

Use wildcards:

cp /home/ankur/folder/* /home/ankur/dest

If you don't want to copy all the files, you can use braces to select files:

cp /home/ankur/folder/{file{1,2},xyz,abc} /home/ankur/dest

This will copy file1, file2, xyz, and abc.

You should read the sections of the bash man page on Brace Expansion and Pathname Expansion for all the ways you can simplify this.

Another thing you can do is cd /home/ankur/folder. Then you can type just the filenames rather than the full pathnames, and you can use filename completion by typing Tab.

Bootstrap Dropdown menu is not working

Maybe try with

<script src="//ajax.googleapis.com/ajax/libs/jquery/1.11.0/jquery.min.js"></script>
<script src="//netdna.bootstrapcdn.com/bootstrap/3.1.1/js/bootstrap.min.js"></script>
<link rel="stylesheet" type="text/css" href="//netdna.bootstrapcdn.com/bootstrap/3.1.1/css/bootstrap.min.css">

and see if it will work.

What to do with commit made in a detached head

checkout actual-branch

git merge {{commit-hash}}

Iterating C++ vector from the end to the beginning

Here's a super simple implementation that allows use of the for each construct and relies only on C++14 std library:

namespace Details {

    // simple storage of a begin and end iterator
    template<class T>
    struct iterator_range
    {
        T beginning, ending;
        iterator_range(T beginning, T ending) : beginning(beginning), ending(ending) {}

        T begin() const { return beginning; }
        T end() const { return ending; }
    };

}

/////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
// usage:
//  for (auto e : backwards(collection))
template<class T>
auto backwards(T & collection)
{
    using namespace std;
    return Details::iterator_range(rbegin(collection), rend(collection));
}

This works with things that supply an rbegin() and rend(), as well as with static arrays.

std::vector<int> collection{ 5, 9, 15, 22 };
for (auto e : backwards(collection))
    ;

long values[] = { 3, 6, 9, 12 };
for (auto e : backwards(values))
    ;

SQL - IF EXISTS UPDATE ELSE INSERT Syntax Error

INSERT INTO component_psar (tbl_id, row_nr, col_1, col_2, col_3, col_4, col_5, col_6, unit, add_info, fsar_lock)
VALUES('2', '1', '1', '1', '1', '1', '1', '1', '1', '1', 'N')
ON DUPLICATE KEY UPDATE col_1 = VALUES(col_1), col_2 = VALUES(col_2), col_3 = VALUES(col_3), col_4 = VALUES(col_4), col_5 = VALUES(col_5), col_6 = VALUES(col_6), unit = VALUES(unit), add_info = VALUES(add_info), fsar_lock = VALUES(fsar_lock)

Would work with tbl_id and row_nr having UNIQUE key.

This is the method DocJonas linked to with an example.

Full width layout with twitter bootstrap

Just create another class and add along with the bootstrap container class. You can also use container-fluid though.

<div class="container full-width">
    <div class="row">
        ....
    </div>
</div>

The CSS part is pretty simple

* {
    margin: 0;
    padding: 0;
}
.full-width {
    width: 100%;
    min-width: 100%;
    max-width: 100%;
}

Hope this helps, Thanks!

Android: How to Programmatically set the size of a Layout

You can get the actual height of called layout with this code:

public int getLayoutSize() {
// Get the layout id
    final LinearLayout root = (LinearLayout) findViewById(R.id.mainroot);
    final AtomicInteger layoutHeight = new AtomicInteger();

    root.post(new Runnable() { 
    public void run() { 
        Rect rect = new Rect(); 
        Window win = getWindow();  // Get the Window
                win.getDecorView().getWindowVisibleDisplayFrame(rect);

                // Get the height of Status Bar
                int statusBarHeight = rect.top;

                // Get the height occupied by the decoration contents 
                int contentViewTop = win.findViewById(Window.ID_ANDROID_CONTENT).getTop();

                // Calculate titleBarHeight by deducting statusBarHeight from contentViewTop  
                int titleBarHeight = contentViewTop - statusBarHeight; 
                Log.i("MY", "titleHeight = " + titleBarHeight + " statusHeight = " + statusBarHeight + " contentViewTop = " + contentViewTop); 

                // By now we got the height of titleBar & statusBar
                // Now lets get the screen size
                DisplayMetrics metrics = new DisplayMetrics();
                getWindowManager().getDefaultDisplay().getMetrics(metrics);   
                int screenHeight = metrics.heightPixels;
                int screenWidth = metrics.widthPixels;
                Log.i("MY", "Actual Screen Height = " + screenHeight + " Width = " + screenWidth);   

                // Now calculate the height that our layout can be set
                // If you know that your application doesn't have statusBar added, then don't add here also. Same applies to application bar also 
                layoutHeight.set(screenHeight - (titleBarHeight + statusBarHeight));
                Log.i("MY", "Layout Height = " + layoutHeight);   

            // Lastly, set the height of the layout       
            FrameLayout.LayoutParams rootParams = (FrameLayout.LayoutParams)root.getLayoutParams();
            rootParams.height = layoutHeight.get();
            root.setLayoutParams(rootParams);
        }
    });

return layoutHeight.get();
}

Replace transparency in PNG images with white background

Welp it looks like my decision to install "graphics magick" over "image magick" has some rough edges - when I reinstall genuine crufty old "image magick", then the above command works perfectly well.

edit, a long time later — One of these days I'll check to see if "graphics magick" has fixed this issue.

Oracle 12c Installation failed to access the temporary location

The error is caused due to administrative shares are being disabled. If they cannot be enabled then perform the following workaround:

6.2.23 INS-30131 Error When Installing Oracle Database or Oracle Client

If the administrative shares are not enabled when performing a single instance Oracle Database or Oracle Client installation for 12c Release 1 (12.1) on Microsoft Windows 7, Microsoft Windows 8, and Microsoft Windows 10, then the installation fails with an INS-30131 error.

Workaround:

Execute the net share command to ensure that the administrative shares are enabled. If they are disabled, then enable them by following the instructions in the Microsoft Windows documentation. Alternatively, perform the client or server installation by specifying the following options:

  • For a client installation:

    -ignorePrereq -J"-Doracle.install.client.validate.clientSupportedOSCheck=false"

  • For a server installation:

    -ignorePrereq -J"-Doracle.install.db.validate.supportedOSCheck=false"

This issue is tracked with Oracle bug 21452473.

Source: Oracle Database Release Notes (Section 6.2.23)

What are the differences between a program and an application?

My understanding is this:

  • A computer program is a set of instructions that can be executed on a computer.
  • An application is software that directly helps a user perform tasks.
  • The two intersect, but are not synonymous. A program with a user-interface is an application, but many programs are not applications.

Drop rows containing empty cells from a pandas DataFrame

Pythonic + Pandorable: df[df['col'].astype(bool)]

Empty strings are falsy, which means you can filter on bool values like this:

df = pd.DataFrame({
    'A': range(5),
    'B': ['foo', '', 'bar', '', 'xyz']
})
df
   A    B
0  0  foo
1  1     
2  2  bar
3  3     
4  4  xyz
df['B'].astype(bool)                                                                                                                      
0     True
1    False
2     True
3    False
4     True
Name: B, dtype: bool

df[df['B'].astype(bool)]                                                                                                                  
   A    B
0  0  foo
2  2  bar
4  4  xyz

If your goal is to remove not only empty strings, but also strings only containing whitespace, use str.strip beforehand:

df[df['B'].str.strip().astype(bool)]
   A    B
0  0  foo
2  2  bar
4  4  xyz

Faster than you Think

.astype is a vectorised operation, this is faster than every option presented thus far. At least, from my tests. YMMV.

Here is a timing comparison, I've thrown in some other methods I could think of.

enter image description here

Benchmarking code, for reference:

import pandas as pd
import perfplot

df1 = pd.DataFrame({
    'A': range(5),
    'B': ['foo', '', 'bar', '', 'xyz']
})

perfplot.show(
    setup=lambda n: pd.concat([df1] * n, ignore_index=True),
    kernels=[
        lambda df: df[df['B'].astype(bool)],
        lambda df: df[df['B'] != ''],
        lambda df: df[df['B'].replace('', np.nan).notna()],  # optimized 1-col
        lambda df: df.replace({'B': {'': np.nan}}).dropna(subset=['B']),  
    ],
    labels=['astype', "!= ''", "replace + notna", "replace + dropna", ],
    n_range=[2**k for k in range(1, 15)],
    xlabel='N',
    logx=True,
    logy=True,
    equality_check=pd.DataFrame.equals)

How can prepared statements protect from SQL injection attacks?

When you create and send a prepared statement to the DBMS, it's stored as the SQL query for execution.

You later bind your data to the query such that the DBMS uses that data as the query parameters for execution (parameterization). The DBMS doesn't use the data you bind as a supplemental to the already compiled SQL query; it's simply the data.

This means it's fundamentally impossible to perform SQL injection using prepared statements. The very nature of prepared statements and their relationship with the DBMS prevents this.

The proxy server received an invalid response from an upstream server

This is not mentioned in you post but I suspect you are initiating an SSL connection from the browser to Apache, where VirtualHosts are configured, and Apache does a revese proxy to your Tomcat.

There is a serious bug in (some versions ?) of IE that sends the 'wrong' host information in an SSL connection (see EDIT below) and confuses the Apache VirtualHosts. In short the server name presented is the one of the reverse DNS resolution of the IP, not the one in the URL.

The workaround is to have one IP address per SSL virtual hosts/server name. Is short, you must end up with something like

1 server name == 1 IP address == 1 certificate == 1 Apache Virtual Host

EDIT

Though the conclusion is correct, the identification of the problem is better described here http://en.wikipedia.org/wiki/Server_Name_Indication

How to Replace dot (.) in a string in Java

return sentence.replaceAll("\s",".");

How to create a list of objects?

In Python, the name of the class refers to the class instance. Consider:

class A: pass
class B: pass
class C: pass

lst = [A, B, C]

# instantiate second class
b_instance = lst[1]()
print b_instance

Create comma separated strings C#?

You could override your object's ToString() method:

public override string ToString ()
{
    return string.Format ("{0},{1},{2}", this.number, this.id, this.whatever);
}

PHP MySQL Google Chart JSON - Complete Example

Some might encounter this error (I got it while implementing PHP-MySQLi-JSON-Google Chart Example):

You called the draw() method with the wrong type of data rather than a DataTable or DataView.

The solution would be: replace jsapi and just use loader.js with:

google.charts.load('current', {packages: ['corechart']}) and 
google.charts.setOnLoadCallback 

-- according to the release notes --> The version of Google Charts that remains available via the jsapi loader is no longer being updated consistently. Please use the new gstatic loader from now on.

Convert ascii value to char

for (int i = 0; i < 5; i++){
    int asciiVal = rand()%26 + 97;
    char asciiChar = asciiVal;
    cout << asciiChar << " and ";
}

How to format column to number format in Excel sheet?

Sorry to bump an old question but the answer is to count the character length of the cell and not its value.

CellCount = Cells(Row, 10).Value
If Len(CellCount) <= "13" Then
'do something
End If

hope that helps. Cheers

Validating a Textbox field for only numeric input.

        if (int.TryParse(txtDepartmentNo.Text, out checkNumber) == false)
        {
            lblMessage.Text = string.Empty;
            lblMessage.Visible = true;
            lblMessage.ForeColor = Color.Maroon;
            lblMessage.Text = "You have not entered a number";
            return;
        }

Postgres: How to do Composite keys?

The error you are getting is in line 3. i.e. it is not in

CONSTRAINT no_duplicate_tag UNIQUE (question_id, tag_id)

but earlier:

CREATE TABLE tags
     (
              (question_id, tag_id) NOT NULL,

Correct table definition is like pilcrow showed.

And if you want to add unique on tag1, tag2, tag3 (which sounds very suspicious), then the syntax is:

CREATE TABLE tags (
    question_id INTEGER NOT NULL,
    tag_id SERIAL NOT NULL,
    tag1 VARCHAR(20),
    tag2 VARCHAR(20),
    tag3 VARCHAR(20),
    PRIMARY KEY(question_id, tag_id),
    UNIQUE (tag1, tag2, tag3)
);

or, if you want to have the constraint named according to your wish:

CREATE TABLE tags (
    question_id INTEGER NOT NULL,
    tag_id SERIAL NOT NULL,
    tag1 VARCHAR(20),
    tag2 VARCHAR(20),
    tag3 VARCHAR(20),
    PRIMARY KEY(question_id, tag_id),
    CONSTRAINT some_name UNIQUE (tag1, tag2, tag3)
);

LINQ to SQL using GROUP BY and COUNT(DISTINCT)

Linq to sql has no support for Count(Distinct ...). You therefore have to map a .NET method in code onto a Sql server function (thus Count(distinct.. )) and use that.

btw, it doesn't help if you post pseudo code copied from a toolkit in a format that's neither VB.NET nor C#.

Run C++ in command prompt - Windows

This is what I used on MAC.

Use your preferred compiler.

Compile with gcc.

gcc -lstdc++ filename.cpp -o outputName

Or Compile with clang.

clang++ filename.cpp -o outputName

After done compiling. You can run it with.

./outputFile

getDate with Jquery Datepicker

Instead of parsing day, month and year you can specify date formats directly using datepicker's formatDate function. In my example I am using "yy-mm-dd", but you can use any format of your choice.

$("#datepicker").datepicker({
    dateFormat: 'yy-mm-dd',
    inline: true,
    minDate: new Date(2010, 1 - 1, 1),
    maxDate: new Date(2010, 12 - 1, 31),
    altField: '#datepicker_value',
    onSelect: function(){
        var fullDate = $.datepicker.formatDate("yy-mm-dd", $(this).datepicker('getDate'));
        var str_output = "<h1><center><img src=\"/images/a" + fullDate +".png\"></center></h1><br/><br>";
        $('#page_output').html(str_output);
    }
});

How to keep :active css style after click a button

CSS

:active denotes the interaction state (so for a button will be applied during press), :focus may be a better choice here. However, the styling will be lost once another element gains focus.

The final potential alternative using CSS would be to use :target, assuming the items being clicked are setting routes (e.g. anchors) within the page- however this can be interrupted if you are using routing (e.g. Angular), however this doesnt seem the case here.

_x000D_
_x000D_
.active:active {_x000D_
  color: red;_x000D_
}_x000D_
.focus:focus {_x000D_
  color: red;_x000D_
}_x000D_
:target {_x000D_
  color: red;_x000D_
}
_x000D_
<button class='active'>Active</button>_x000D_
<button class='focus'>Focus</button>_x000D_
<a href='#target1' id='target1' class='target'>Target 1</a>_x000D_
<a href='#target2' id='target2' class='target'>Target 2</a>_x000D_
<a href='#target3' id='target3' class='target'>Target 3</a>
_x000D_
_x000D_
_x000D_

Javascript / jQuery

As such, there is no way in CSS to absolutely toggle a styled state- if none of the above work for you, you will either need to combine with a change in your HTML (e.g. based on a checkbox) or programatically apply/remove a class using e.g. jQuery

_x000D_
_x000D_
$('button').on('click', function(){_x000D_
    $('button').removeClass('selected');_x000D_
    $(this).addClass('selected');_x000D_
});
_x000D_
button.selected{_x000D_
  color:red;_x000D_
}
_x000D_
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>_x000D_
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<button>Item</button><button>Item</button><button>Item</button>_x000D_
  
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How to limit depth for recursive file list?

tree -L 2 -u -g -p -d

Prints the directory tree in a pretty format up to depth 2 (-L 2). Print user (-u) and group (-g) and permissions (-p). Print only directories (-d). tree has a lot of other useful options.

Access parent URL from iframe

If your iframe is from another domain, (cross domain), you will simply need to use this:

var currentUrl = document.referrer;

and - here you've got the main url!

Express.js Response Timeout

There is already a Connect Middleware for Timeout support:

var timeout = express.timeout // express v3 and below
var timeout = require('connect-timeout'); //express v4

app.use(timeout(120000));
app.use(haltOnTimedout);

function haltOnTimedout(req, res, next){
  if (!req.timedout) next();
}

If you plan on using the Timeout middleware as a top-level middleware like above, the haltOnTimedOut middleware needs to be the last middleware defined in the stack and is used for catching the timeout event. Thanks @Aichholzer for the update.

Side Note:

Keep in mind that if you roll your own timeout middleware, 4xx status codes are for client errors and 5xx are for server errors. 408s are reserved for when:

The client did not produce a request within the time that the server was prepared to wait. The client MAY repeat the request without modifications at any later time.

"SetPropertiesRule" warning message when starting Tomcat from Eclipse

I'm finding that Tomcat can't seem to find classes defined in other projects, maybe even in the main project. It's failing on the filter definition which is the first definition in web.xml. If I add the project and its dependencies to the server's launch configuration then I just move on to a new error, all of which seems to point to it not setting up the project properly.

Our setup is quite complex. We have multiple components as projects in Eclipse with separate output projects. We have a separate webapp directory which contains the static HTML and images, as well as our WEB-INF.

Eclipse is "Europa Winter release". Tomcat is 6.0.18. I tried version 2.4 and 2.5 of the "Dynamic Web Module" facet.

Thanks for any help!

  • Richard

CSS centred header image

I think this is what you need if I'm understanding you correctly:

<div id="wrapperHeader">
 <div id="header">
  <img src="images/logo.png" alt="logo" />
 </div> 
</div>



div#wrapperHeader {
 width:100%;
 height;200px; /* height of the background image? */
 background:url(images/header.png) repeat-x 0 0;
 text-align:center;
}

div#wrapperHeader div#header {
 width:1000px;
 height:200px;
 margin:0 auto;
}

div#wrapperHeader div#header img {
 width:; /* the width of the logo image */
 height:; /* the height of the logo image */
 margin:0 auto;
}

Difference between Interceptor and Filter in Spring MVC

From HandlerIntercepter's javadoc:

HandlerInterceptor is basically similar to a Servlet Filter, but in contrast to the latter it just allows custom pre-processing with the option of prohibiting the execution of the handler itself, and custom post-processing. Filters are more powerful, for example they allow for exchanging the request and response objects that are handed down the chain. Note that a filter gets configured in web.xml, a HandlerInterceptor in the application context.

As a basic guideline, fine-grained handler-related pre-processing tasks are candidates for HandlerInterceptor implementations, especially factored-out common handler code and authorization checks. On the other hand, a Filter is well-suited for request content and view content handling, like multipart forms and GZIP compression. This typically shows when one needs to map the filter to certain content types (e.g. images), or to all requests.

With that being said:

So where is the difference between Interceptor#postHandle() and Filter#doFilter()?

postHandle will be called after handler method invocation but before the view being rendered. So, you can add more model objects to the view but you can not change the HttpServletResponse since it's already committed.

doFilter is much more versatile than the postHandle. You can change the request or response and pass it to the chain or even block the request processing.

Also, in preHandle and postHandle methods, you have access to the HandlerMethod that processed the request. So, you can add pre/post-processing logic based on the handler itself. For example, you can add a logic for handler methods that have some annotations.

What is the best practise in which use cases it should be used?

As the doc said, fine-grained handler-related pre-processing tasks are candidates for HandlerInterceptor implementations, especially factored-out common handler code and authorization checks. On the other hand, a Filter is well-suited for request content and view content handling, like multipart forms and GZIP compression. This typically shows when one needs to map the filter to certain content types (e.g. images), or to all requests.

How can I convert IPV6 address to IPV4 address?

The IPAddress Java library can accomplish what you are describing here.

IPv6 addresses are 16 bytes. Using that library, if you are starting with a 16-byte array you can construct the IPv6 address object:

IPv6Address addr = new IPv6Address(bytes); //bytes is byte[16]

From there you can check if the address is IPv4 mapped, IPv4 compatible, IPv4 translated, and so on (there are many possible ways IPv6 represents IPv4 addresses). In most cases, if an IPv6 address represents an IPv4 address, the ipv4 address is in the lower 4 bytes, and so you can get the derived IPv4 address as follows. Afterwards, you can convert back to bytes, which will be just 4 bytes for IPv4.

    if(addr.isIPv4Compatible() || addr.isIPv4Mapped()) {
        IPv4Address derivedIpv4Address = addr.getEmbeddedIPv4Address();
        byte ipv4Bytes[] = derivedIpv4Address.getBytes();
        ...
     }

The javadoc is available at the link.

How can I run a html file from terminal?

Skip reading the html and use curl to POST whatever form data you want to submit to the server.

Are querystring parameters secure in HTTPS (HTTP + SSL)?

The entire transmission, including the query string, the whole URL, and even the type of request (GET, POST, etc.) is encrypted when using HTTPS.

How could I put a border on my grid control in WPF?

I think your problem is that the margin should be specified in the border tag and not in the grid.

Tensorflow: Using Adam optimizer

You need to call tf.global_variables_initializer() on you session, like

init = tf.global_variables_initializer()
sess.run(init)

Full example is available in this great tutorial https://www.tensorflow.org/get_started/mnist/mechanics

How to update a record using sequelize for node?

I think using UPDATE ... WHERE as explained here and here is a lean approach

Project.update(
      { title: 'a very different title no' } /* set attributes' value */, 
      { where: { _id : 1 }} /* where criteria */
).then(function(affectedRows) {
Project.findAll().then(function(Projects) {
     console.log(Projects) 
})

Loop through a Map with JSTL

You can loop through a hash map like this

<%
ArrayList list = new ArrayList();
TreeMap itemList=new TreeMap();
itemList.put("test", "test");
list.add(itemList);
pageContext.setAttribute("itemList", list);                            
%>

  <c:forEach items="${itemList}" var="itemrow">
   <input  type="text"  value="<c:out value='${itemrow.test}'/>"/>
  </c:forEach>               

For more JSTL functionality look here

Document Root PHP

The Easiest way to do it is to have good site structure and write it as a constant.

DEFINE("BACK_ROOT","/var/www/");

MySQL, Concatenate two columns

$crud->set_relation('id','students','{first_name} {last_name}');
$crud->display_as('student_id','Students Name');

Python: call a function from string name

Why cant we just use eval()?

def install():
    print "In install"

New method

def installWithOptions(var1, var2):
    print "In install with options " + var1 + " " + var2

And then you call the method as below

method_name1 = 'install()'
method_name2 = 'installWithOptions("a","b")'
eval(method_name1)
eval(method_name2)

This gives the output as

In install
In install with options a b

Difference between /res and /assets directories

Following are some key points :

  1. Raw files Must have names that are valid Java identifiers , whereas files in Assets Have no location and name restrictions. In other words they can be grouped in whatever directories we wish
  2. Raw files Are easy to refer to from Java as well as from xml (i.e you can refer a file in raw from manifest or other xml file).
  3. Saving asset files here instead of in the assets/ directory only differs in the way that you access them as documented here http://developer.android.com/tools/projects/index.html.
  4. Resources defined in a library project are automatically imported to application projects that depend on the library. For assets, that doesn't happen; asset files must be present in the assets directory of the application project(s)
  5. The assets directory is more like a filesystem provides more freedom to put any file you would like in there. You then can access each of the files in that system as you would when accessing any file in any file system through Java . like Game data files , Fonts , textures etc.
  6. Unlike Resources, Assets can can be organized into subfolders in the assets directory However, the only thing you can do with an asset is get an input stream. Thus, it does not make much sense to store your strings or bitmaps in assets, but you can store custom-format data such as input correction dictionaries or game maps.
  7. Raw can give you a compile time check by generating your R.java file however If you want to copy your database to private directory you can use Assets which are made for streaming.

Conclusion

  1. Android API includes a very comfortable Resources framework that is also optimized for most typical use cases for various mobile apps. You should master Resources and try to use them wherever possible.
  2. However, if you need more flexibility for your special case, Assets are there to give you a lower level API that allows organizing and processing your resources with a higher degree of freedom.

android.content.Context.getPackageName()' on a null object reference

Due to onAttach is deprecated in API23 and above... In my Fragment, I declare and set parentActivity before hand everytime when I go into Fragment. Most likely happen due to when we pressed back button caused the context to become null. Therefore below is my solution.

private Activity parentActivity;

public void onStart(){
        super.onStart();
        parentActivity = getActivity();
//...

}

Show all tables inside a MySQL database using PHP?

SHOW TABLE_NAME is not valid. Try SHOW TABLES

TD

Error: " 'dict' object has no attribute 'iteritems' "

As answered by RafaelC, Python 3 renamed dict.iteritems -> dict.items. Try a different package version. This will list available packages:

python -m pip install yourOwnPackageHere==

Then rerun with the version you will try after == to install/switch version

Laravel Migration Change to Make a Column Nullable

Laravel 5 now supports changing a column; here's an example from the offical documentation:

Schema::table('users', function($table)
{
    $table->string('name', 50)->nullable()->change();
});

Source: http://laravel.com/docs/5.0/schema#changing-columns

Laravel 4 does not support modifying columns, so you'll need use another technique such as writing a raw SQL command. For example:

// getting Laravel App Instance
$app = app();

// getting laravel main version
$laravelVer = explode('.',$app::VERSION);

switch ($laravelVer[0]) {

    // Laravel 4
    case('4'):

        DB::statement('ALTER TABLE `pro_categories_langs` MODIFY `name` VARCHAR(100) NULL;');
        break;

    // Laravel 5, or Laravel 6
    default:                

        Schema::table('pro_categories_langs', function(Blueprint $t) {
            $t->string('name', 100)->nullable()->change();
        });               

}

How can I iterate over the elements in Hashmap?

Since all the players are numbered I would just use an ArrayList<Player>()

Something like

List<Player> players = new ArrayList<Player>();

System.out.printf("Give the number of the players ");
int number_of_players = scanner.nextInt();
scanner.nextLine(); // discard the rest of the line.

for(int k = 0;k < number_of_players; k++){
     System.out.printf("Give the name of player %d: ", k + 1);
     String name_of_player = scanner.nextLine();
     players.add(new Player(name_of_player,0)); //k=id and 0=score
}

for(Player player: players) {  
    System.out.println("Name of player in this round:" + player.getName());

Azure SQL Database "DTU percentage" metric

Still not cool enough to comment, but regarding @vladislav's comment the original article was fairly old. Here is an update document regarding DTU's, which would help answer the OP's question.

https://docs.microsoft.com/en-us/azure/sql-database/sql-database-what-is-a-dtu

Oracle TNS names not showing when adding new connection to SQL Developer

You can always find out the location of the tnsnames.ora file being used by running TNSPING to check connectivity (9i or later):

C:\>tnsping dev

TNS Ping Utility for 32-bit Windows: Version 10.2.0.1.0 - Production on 08-JAN-2009 12:48:38

Copyright (c) 1997, 2005, Oracle.  All rights reserved.

Used parameter files:
C:\oracle\product\10.2.0\client_1\NETWORK\ADMIN\sqlnet.ora


Used TNSNAMES adapter to resolve the alias
Attempting to contact (DESCRIPTION = (ADDRESS = (PROTOCOL = TCP)(HOST = XXX)(PORT = 1521)) (CONNECT_DATA = (SERVICE_NAME = DEV)))
OK (30 msec)

C:\>

Sometimes, the problem is with the entry you made in tnsnames.ora, not that the system can't find it. That said, I agree that having a tns_admin environment variable set is a Good Thing, since it avoids the inevitable issues that arise with determining exactly which tnsnames file is being used in systems with multiple oracle homes.

HTML not loading CSS file

I had been facing the same issue,

For Chrome and Firefox but everything was working how it should in internet explorer. I found that making the CSS file UTF-8 made it work for chrome.

Who is listening on a given TCP port on Mac OS X?

This did what I needed.

ps -eaf | grep `lsof -t -i:$PORT`

Deleting row from datatable in C#

This question will give you good insights on how to delete a record from a DataTable:

DataTable, How to conditionally delete rows

It would look like this:

DataRow[] drr = dt.Select("Student=' " + id + " ' "); 
foreach (var row in drr)
   row.Delete();

Don't forget that if you want to update your database, you are going to need to call the Update command. For more information on that, see this link:

http://www.codeguru.com/forum/showthread.php?t=471027

How can I backup a Docker-container with its data-volumes?

If you want a complete backup, you will need to perform a few steps:

  1. Commit the container to an image
  2. Save the image
  3. Backup the container's volume by creating a tar file of the volume's mount point in the container.
  4. Repeat steps 1-3 for the database container as well.

Note that doing just a Docker commit of the container to an image does NOT include volumes attached to the container (ref: Docker commit documentation).

"The commit operation will not include any data contained in volumes mounted inside the container."

Angular ng-if not true

Use like this

<div ng-if="data.IsActive === 1">InActive</div>
<div ng-if="data.IsActive === 0">Active</div>

Add element to a list In Scala

I will try to explain the results of all the commands you tried.

scala> val l = 1.0 :: 5.5 :: Nil
l: List[Double] = List(1.0, 5.5)

First of all, List is a type alias to scala.collection.immutable.List (defined in Predef.scala).

Using the List companion object is more straightforward way to instantiate a List. Ex: List(1.0,5.5)

scala> l
res0: List[Double] = List(1.0, 5.5)

scala> l ::: List(2.2, 3.7)
res1: List[Double] = List(1.0, 5.5, 2.2, 3.7)

::: returns a list resulting from the concatenation of the given list prefix and this list

The original List is NOT modified

scala> List(l) :+ 2.2
res2: List[Any] = List(List(1.0, 5.5), 2.2)

List(l) is a List[List[Double]] Definitely not what you want.

:+ returns a new list consisting of all elements of this list followed by elem.

The type is List[Any] because it is the common superclass between List[Double] and Double

scala> l
res3: List[Double] = List(1.0, 5.5)

l is left unmodified because no method on immutable.List modified the List.

How to search file text for a pattern and replace it with a given value

In my case I am using tty-gem ruby gem for that.

I also needed appending, prepending (on a given text/regex inside the file), diffs, and others. The gem includes all that and a fairly clear documentation.

Aesthetics must either be length one, or the same length as the dataProblems

I encountered this problem because the dataset was filtered wrongly and the resultant data frame was empty. Even the following caused the error to show:

ggplot(df, aes(x="", y = y, fill=grp))

because df was empty.

How can I right-align text in a DataGridView column?

To set align text in dataGridCell you have two ways:

Set the align for a specific cell or set for each cell of row.

For one column go to Columns->DataGridViewCellStyle

or

For each column go to RowDefaultCellStyle

The control panel is the same as the follow:

enter image description here