Razor/CSHTML - Any Benefit over what we have?

One of the benefits is that Razor views can be rendered inside unit tests, this is something that was not easily possible with the previous ASP.Net renderer.

From ScottGu's announcement this is listed as one of the design goals:

Unit Testable: The new view engine implementation will support the ability to unit test views (without requiring a controller or web-server, and can be hosted in any unit test project – no special app-domain required).

How to install xgboost in Anaconda Python (Windows platform)?

if you found an issue when you try to import xgboost (my case it is Windows 10 and anaconda spyder) do the following:

Click on the windows icon (start button!)
Select and expand the anaconda folder
Run the Anaconda Prompt (as Administrator)
Type the following command as it is mentioned in https://anaconda.org/anaconda/py-xgboost

conda install -c anaconda py-xgboost

That's all...Good luck.

Is there any way to start with a POST request using Selenium?

from selenium import webdriver

driver = webdriver.Firefox()
driver.implicitly_wait(12)
driver.set_page_load_timeout(10)

def _post_selenium(self, url: str, data: dict):
    input_template = '{k} <input type="text" name="{k}" id="{k}" value="{v}"><BR>\n'
    inputs = ""
    if data:
        for k, v in data.items():
            inputs += input_template.format(k=k, v=v)
    html = f'<html><body>\n<form action="{url}" method="post" id="formid">\n{inputs}<input type="submit" id="inputbox">\n</form></body></html>'

    html_file = os.path.join(os.getcwd(), 'temp.html')
    with open(html_file, "w") as text_file:
        text_file.write(html)

    driver.get(f"file://{html_file}")
    driver.find_element_by_id('inputbox').click()

_post_selenium("post.to.my.site.url", {"field1": "val1"})

driver.close()

SQL: parse the first, middle and last name from a fullname field

As everyone else says, you can't from a simple programmatic way.

Consider these examples:

President "George Herbert Walker Bush" (First Middle Middle Last)
Presidential assassin "John Wilkes Booth" (First Middle Last)
Guitarist "Eddie Van Halen" (First Last Last)
And his mom probably calls him Edward Lodewijk Van Halen (First Middle Last Last)
Famed castaway "Mary Ann Summers" (First First Last)
New Mexico GOP chairman "Fernando C de Baca" (First Last Last Last)

How do I check if an object's type is a particular subclass in C++?

I don't know if I understand your problem correctly, so let me restate it in my own words...

Problem: Given classes B and D, determine if D is a subclass of B (or vice-versa?)

Solution: Use some template magic! Okay, seriously you need to take a look at LOKI, an excellent template meta-programming library produced by the fabled C++ author Andrei Alexandrescu.

More specifically, download LOKI and include header TypeManip.h from it in your source code then use the SuperSubclass class template as follows:

if(SuperSubClass<B,D>::value)
{
...
}

According to documentation, SuperSubClass<B,D>::value will be true if B is a public base of D, or if B and D are aliases of the same type.

i.e. either D is a subclass of B or D is the same as B.

I hope this helps.

edit:

Please note the evaluation of SuperSubClass<B,D>::value happens at compile time unlike some methods which use dynamic_cast, hence there is no penalty for using this system at runtime.

How to find the index of an element in an int array?

Simple:

public int getArrayIndex(int[] arr,int value) {
    for(int i=0;i<arr.length;i++)
        if(arr[i]==value) return i;
    return -1;
}

jquery Ajax call - data parameters are not being passed to MVC Controller action

If you have trouble with caching ajax you can turn it off:

$.ajaxSetup({cache: false});

Create Word Document using PHP in Linux

Take a look at PHP COM documents (The comments are helpful) http://us3.php.net/com

React Native add bold or italics to single words in <Text> field

You could just nest the Text components with the required style. The style will be applied along with already defined style in the first Text component.

Example:

 <Text style={styles.paragraph}>
   Trouble singing in. <Text style={{fontWeight: "bold"}}> Resolve</Text>
 </Text>

How can I convert an image into a Base64 string?

If you need Base64 over JSON, check out Jackson: it has explicit support for binary data read/write as Base64 at both the low level (JsonParser, JsonGenerator) and data-binding level. So you can just have POJOs with byte[] properties, and encoding/decoding is automatically handled.

And pretty efficiently too, should that matter.

PHP upload image

Here is a basic example of how an image file with certain restrictions (listed below) can be uploaded to the server.

Existence of the image.
Image extension validation

Checks for image size.

<?php
   $newfilename = "newfilename";

   if(isset($_FILES['image'])){
      $errors= array();
      $file_name = $_FILES['image']['name'];
      $file_size =$_FILES['image']['size'];
      $file_tmp =$_FILES['image']['tmp_name'];
      $file_type=$_FILES['image']['type'];
      $file_ext=strtolower(end(explode('.',$_FILES['image']['name'])));

      $expensions= array("jpeg","jpg","png");
      if(file_exists($file_name)) {
        echo "Sorry, file already exists.";
        }
      if(in_array($file_ext,$expensions)=== false){
         $errors[]="extension not allowed, please choose a JPEG or PNG file.";
      }

      if($file_size > 2097152){
         $errors[]='File size must be excately 2 MB';
      }

      if(empty($errors)==true){
        move_uploaded_file($file_tmp,"images/".$newfilename.".".$file_ext);
        echo "Success";
        echo "<script>window.close();</script>";

      }

      else{
         print_r($errors);
      }
   }
?>
<html>
   <body>

      <form action="" method="POST" enctype="multipart/form-data">
         <input type="file" name="image" />
         <input type="submit"/>
      </form>

   </body>
</html>

Credit to this page.

How do you run a single test/spec file in RSpec?

Although many great answers were written to this question, none of them uses the Rspec tags approach.

I use tags to run one or more specs in different files -- only those related to my current development task.

For example, I add the tag "dev" with the value "current":

it "creates an user", dev: :current do
  user = create(:user)
  expect(user.persisted?).to be_truthy
end

then I run

bundle exec rspec . --tag dev:current

Different tags/values can be set in individual specs or groups.

SQL Error: ORA-00922: missing or invalid option

The error you're getting appears to be the result of the fact that there is no underscore between "chartered" and "flight" in the table name. I assume you want something like this where the name of the table is chartered_flight.

CREATE TABLE chartered_flight(flight_no NUMBER(4) PRIMARY KEY
, customer_id NUMBER(6) REFERENCES customer(customer_id)
, aircraft_no NUMBER(4) REFERENCES aircraft(aircraft_no)
, flight_type VARCHAR2 (12)
, flight_date DATE NOT NULL
, flight_time INTERVAL DAY TO SECOND NOT NULL
, takeoff_at CHAR (3) NOT NULL
, destination CHAR (3) NOT NULL)

Generally, there is no benefit to declaring a column as CHAR(3) rather than VARCHAR2(3). Declaring a column as CHAR(3) doesn't force there to be three characters of (useful) data. It just tells Oracle to space-pad data with fewer than three characters to three characters. That is unlikely to be helpful if someone inadvertently enters an incorrect code. Potentially, you could declare the column as VARCHAR2(3) and then add a CHECK constraint that LENGTH(takeoff_at) = 3.

CREATE TABLE chartered_flight(flight_no NUMBER(4) PRIMARY KEY
, customer_id NUMBER(6) REFERENCES customer(customer_id)
, aircraft_no NUMBER(4) REFERENCES aircraft(aircraft_no)
, flight_type VARCHAR2 (12)
, flight_date DATE NOT NULL
, flight_time INTERVAL DAY TO SECOND NOT NULL
, takeoff_at CHAR (3) NOT NULL CHECK( length( takeoff_at ) = 3 )
, destination CHAR (3) NOT NULL CHECK( length( destination ) = 3 )
)

Since both takeoff_at and destination are airport codes, you really ought to have a separate table of valid airport codes and define foreign key constraints between the chartered_flight table and this new airport_code table. That ensures that only valid airport codes are added and makes it much easier in the future if an airport code changes.

And from a naming convention standpoint, since both takeoff_at and destination are airport codes, I would suggest that the names be complementary and indicate that fact. Something like departure_airport_code and arrival_airport_code, for example, would be much more meaningful.

Matplotlib make tick labels font size smaller

For smaller font, I use

ax1.set_xticklabels(xticklabels, fontsize=7)

and it works!

Node.js Web Application examples/tutorials

Update

Dav Glass from Yahoo has given a talk at YuiConf2010 in November which is now available in Video from.

He shows to great extend how one can use YUI3 to render out widgets on the server side an make them work with GET requests when JS is disabled, or just make them work normally when it's active.

He also shows examples of how to use server side DOM to apply style sheets before rendering and other cool stuff.

The demos can be found on his GitHub Account.

The part that's missing IMO to make this really awesome, is some kind of underlying storage of the widget state. So that one can visit the page without JavaScript and everything works as expected, then they turn JS on and now the widget have the same state as before but work without page reloading, then throw in some saving to the server + WebSockets to sync between multiple open browser.... and the next generation of unobtrusive and gracefully degrading ARIA's is born.

Original Answer

Well go ahead and built it yourself then.

Seriously, 90% of all WebApps out there work fine with a REST approach, of course you could do magical things like superior user tracking, tracking of downloads in real time, checking which parts of videos are being watched etc.

One problem is scalability, as soon as you have more then 1 Node process, many (but not all) of the benefits of having the data stored between requests go away, so you have to make sure that clients always hit the same process. And even then, bigger things will yet again need a database layer.

Node.js isn't the solution to everything, I'm sure people will build really great stuff in the future, but that needs some time, right now many are just porting stuff over to Node to get things going.

What (IMHO) makes Node.js so great, is the fact that it streamlines the Development process, you have to write less code, it works perfectly with JSON, you loose all that context switching.

I mainly did gaming experiments so far, but I can for sure say that there will be many cool multi player (or even MMO) things in the future, that use both HTML5 and Node.js.

Node.js is still gaining traction, it's not even near to the RoR Hype some years ago (just take a look at the Node.js tag here on SO, hardly 4-5 questions a day).

Rome (or RoR) wasn't built over night, and neither will Node.js be.

Node.js has all the potential it needs, but people are still trying things out, so I'd suggest you to join them :)

What is the difference between LATERAL and a subquery in PostgreSQL?

First, Lateral and Cross Apply is same thing. Therefore you may also read about Cross Apply. Since it was implemented in SQL Server for ages, you will find more information about it then Lateral.

Second, according to my understanding, there is nothing you can not do using subquery instead of using lateral. But:

Consider following query.

Select A.*
, (Select B.Column1 from B where B.Fk1 = A.PK and Limit 1)
, (Select B.Column2 from B where B.Fk1 = A.PK and Limit 1)
FROM A

You can use lateral in this condition.

Select A.*
, x.Column1
, x.Column2
FROM A LEFT JOIN LATERAL (
  Select B.Column1,B.Column2,B.Fk1 from B  Limit 1
) x ON X.Fk1 = A.PK

In this query you can not use normal join, due to limit clause. Lateral or Cross Apply can be used when there is not simple join condition.

There are more usages for lateral or cross apply but this is most common one I found.

Wait until page is loaded with Selenium WebDriver for Python

Find below 3 methods:

readyState

Checking page readyState (not reliable):

def page_has_loaded(self):
    self.log.info("Checking if {} page is loaded.".format(self.driver.current_url))
    page_state = self.driver.execute_script('return document.readyState;')
    return page_state == 'complete'

The wait_for helper function is good, but unfortunately click_through_to_new_page is open to the race condition where we manage to execute the script in the old page, before the browser has started processing the click, and page_has_loaded just returns true straight away.

`id`

Comparing new page ids with the old one:

def page_has_loaded_id(self):
    self.log.info("Checking if {} page is loaded.".format(self.driver.current_url))
    try:
        new_page = browser.find_element_by_tag_name('html')
        return new_page.id != old_page.id
    except NoSuchElementException:
        return False

It's possible that comparing ids is not as effective as waiting for stale reference exceptions.

`staleness_of`

Using staleness_of method:

@contextlib.contextmanager
def wait_for_page_load(self, timeout=10):
    self.log.debug("Waiting for page to load at {}.".format(self.driver.current_url))
    old_page = self.find_element_by_tag_name('html')
    yield
    WebDriverWait(self, timeout).until(staleness_of(old_page))

For more details, check Harry's blog.

Install numpy on python3.3 - Install pip for python3

I'm on Ubuntu 15.04. This seemed to work:

$ sudo pip3 install numpy

On RHEL this worked:

$ sudo python3 -m pip install numpy

Converting a factor to numeric without losing information R (as.numeric() doesn't seem to work)

First, factor consists of indices and levels. This fact is very very important when you are struggling with factor.

For example,

> z <- factor(letters[c(3, 2, 3, 4)])

# human-friendly display, but internal structure is invisible
> z
[1] c b c d
Levels: b c d

# internal structure of factor
> unclass(z)
[1] 2 1 2 3
attr(,"levels")
[1] "b" "c" "d"

here, z has 4 elements.
The index is 2, 1, 2, 3 in that order.
The level is associated with each index: 1 -> b, 2 -> c, 3 -> d.

Then, as.numeric converts simply the index part of factor into numeric.
as.character handles the index and levels, and generates character vector expressed by its level.

?as.numeric says that Factors are handled by the default method.

How do I run msbuild from the command line using Windows SDK 7.1?

Your bat file could be like:

CD C:\Windows\Microsoft.NET\Framework64\v4.0.30319

msbuild C:\Users\mmaratt\Desktop\BladeTortoise\build\ALL_BUILD.vcxproj

PAUSE

EXIT

OnClick Send To Ajax

Tried and working. you are using,

<textarea name='Status'> </textarea>
<input type='button' onclick='UpdateStatus()' value='Status Update'>

I am using javascript , (don't know about php), use id ="status" in textarea like

<textarea name='Status' id="status"> </textarea>
<input type='button' onclick='UpdateStatus()' value='Status Update'>

then make a call to servlet sending the status to backend for updating using whatever strutucre(like MVC in java or anyother) you like, like this in your UI in script tag

<srcipt>
function UpdateStatus(){

//make an ajax call and get status value using the same 'id'
var var1= document.getElementById("status").value;
$.ajax({

        type:"GET",//or POST
        url:'http://localhost:7080/ajaxforjson/Testajax',
                           //  (or whatever your url is)
        data:{data1:var1},
        //can send multipledata like {data1:var1,data2:var2,data3:var3
        //can use dataType:'text/html' or 'json' if response type expected 
        success:function(responsedata){
               // process on data
               alert("got response as "+"'"+responsedata+"'");

        }
     })

}
</script>

and jsp is like

the servlet will look like:   //webservlet("/zcvdzv") is just for url annotation
@WebServlet("/Testajax")

public class Testajax extends HttpServlet {
private static final long serialVersionUID = 1L;
public Testajax() {
    super();
}
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
    // TODO Auto-generated method stub
    String data1=request.getParameter("data1");
    //do processing on datas pass in other java class to add to DB
    // i am adding or concatenate
    String data="i Got : "+"'"+data1+"' ";
    System.out.println(" data1 : "+data1+"\n data "+data);
    response.getWriter().write(data);
}
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
    // TODO Auto-generated method stub
    doGet(request, response);
}

}

ImportError: no module named win32api

I had an identical problem, which I solved by restarting my Python editor and shell. I had installed pywin32 but the new modules were not picked up until the restarts.

If you've already done that, do a search in your Python installation for win32api and you should find win32api.pyd under ${PYTHON_HOME}\Lib\site-packages\win32.

How to display the string html contents into webbrowser control?

webBrowser.NavigateToString(yourString);

How to get the width and height of an android.widget.ImageView?

Post to the UI thread works for me.

final ImageView iv = (ImageView)findViewById(R.id.scaled_image);

iv.post(new Runnable() {
            @Override
            public void run() {
                int width = iv.getMeasuredWidth();
                int height = iv.getMeasuredHeight();

            }
});

Can I inject a service into a directive in AngularJS?

You can do injection on Directives, and it looks just like it does everywhere else.

app.directive('changeIt', ['myData', function(myData){
    return {
        restrict: 'C',
        link: function (scope, element, attrs) {
            scope.name = myData.name;
        }
    }
 }]);

findViewByID returns null

Alongside the classic causes, mentioned elsewhere:

Make sure you've called setContentView() before findViewById()
Make sure that the id you want is in the view or layout you've given to setContentView()
Make sure that the id isn't accidentally duplicated in different layouts

There is one I have found for custom views in standard layouts, which goes against the documentation:

In theory you can create a custom view and add it to a layout (see here). However, I have found that in such situations, sometimes the id attribute works for all the views in the layout except the custom ones. The solution I use is:

Replace each custom view with a FrameLayout with the same layout properties as you would like the custom view to have. Give it an appropriate id, say frame_for_custom_view.

In onCreate:

setContentView(R.layout.my_layout);
FrameView fv = findViewById(R.id.frame_for_custom_layout);
MyCustomView cv = new MyCustomView(context);
fv.addView(cv);

which puts the custom view in the frame.

how to add the missing RANDR extension

First off, Xvfb doesn't read configuration from xorg.conf. Xvfb is a variant of the KDrive X servers and like all members of that family gets its configuration from the command line.

It is true that XRandR and Xinerama are mutually exclusive, but in the case of Xvfb there's no Xinerama in the first place. You can enable the XRandR extension by starting Xvfb using at least the following command line options

Xvfb +extension RANDR [further options]

Find empty or NaN entry in Pandas Dataframe

you also do something good:

text_empty = df['column name'].str.len() > -1

df.loc[text_empty].index

The results will be the rows which are empty & it's index number.

Determine installed PowerShell version

Use $PSVersionTable.PSVersion to determine the engine version. If the variable does not exist, it is safe to assume the engine is version 1.0.

Note that $Host.Version and (Get-Host).Version are not reliable - they reflect the version of the host only, not the engine. PowerGUI, PowerShellPLUS, etc. are all hosting applications, and they will set the host's version to reflect their product version — which is entirely correct, but not what you're looking for.

PS C:\> $PSVersionTable.PSVersion

Major  Minor  Build  Revision
-----  -----  -----  --------
4      0      -1     -1

How to parse JSON in Kotlin?

A bit late, but whatever.

If you prefer parsing JSON to JavaScript-like constructs making use of Kotlin syntax, I recommend JSONKraken, of which I am the author.

Suggestions and opinions on the matter are much apreciated!

batch script - run command on each file in directory

for /r %%v in (*.xls) do ssconvert "%%v" "%%vx"

a couple have people have asked me to explain this, so:

Part 1: for /r %%v in (*.xls)

This part returns an array of files in the current directory that have the xls extension. The %% may look a little curious. This is basically the special % character from command line as used in %PATH% or %TEMP%. To use it in a batch file we need to escape it like so: %%PATH%% or %%TEMP%%. In this case we are simply escaping the temporary variable v, which will hold our array of filenames.

We are using the /r switch to search for files recursively, so any matching files in child folders will also be located.

Part 2: do ssconvert "%%v" "%%vx"

This second part is what will get executed once per matching filename, so if the following files were present in the current folder:

c:\temp\mySheet.xls, c:\temp\mySheet_yesterday.xls, c:\temp\mySheet_20160902.xls

the following commands would be executed:

ssconvert "c:\temp\mySheet.xls" "c:\temp\mySheet.xlsx" ssconvert "c:\temp\mySheet_yesterday.xls" "c:\temp\mySheet_yesterday.xlsx" ssconvert "c:\temp\mySheet_20160902.xls" "c:\temp\mySheet_20160902.xlsx"

Can a PDF file's print dialog be opened with Javascript?

Why not use the Actions menu option to set this?

Do the following: If you have Acrobat Pro, go to your pages tab, right click on the thumbnail for the first page, and click page properties. Click on the actions tab at the top of the window and under select trigger choose page open. Under select action choose 'Execute a menu item'. Click the Add button then select 'File > Print' then OK. Click OK again and save the PDF.

ModelState.AddModelError - How can I add an error that isn't for a property?

I eventually stumbled upon an example of the usage I was looking for - to assign an error to the Model in general, rather than one of it's properties, as usual you call:

ModelState.AddModelError(string key, string errorMessage);

but use an empty string for the key:

ModelState.AddModelError(string.Empty, "There is something wrong with Foo.");

The error message will present itself in the <%: Html.ValidationSummary() %> as you'd expect.

How can I display a list view in an Android Alert Dialog?

Isn't it smoother to make a method to be called after the creation of the EditText unit in an AlertDialog, for general use?

public static void EditTextListPicker(final Activity activity, final EditText EditTextItem, final String SelectTitle, final String[] SelectList) {
    EditTextItem.setOnLongClickListener(new View.OnLongClickListener() {
        @Override
        public boolean onLongClick(View v) {
            AlertDialog.Builder builder = new AlertDialog.Builder(activity);
            builder.setTitle(SelectTitle);
            builder.setItems(SelectList, new DialogInterface.OnClickListener() {
                public void onClick(DialogInterface dialogInterface, int item) {
                    EditTextItem.setText(SelectList[item]);
                }
            });
            builder.create().show();
            return false;
        }
    });
}

java.lang.NoClassDefFoundError:failed resolution of :Lorg/apache/http/ProtocolVersion

If You using Android 9.0 with legacy jar than you have to use. in your mainfest file.

<uses-library android:name="org.apache.http.legacy" android:required="false"/>

How to install python developer package?

For me none of the packages mentioned above did help.

I finally managed to install lxml after running:

sudo apt-get install python3.5-dev

How can I check if mysql is installed on ubuntu?

Try executing 'mysql' or 'mysql -- version' without quotes on terminal. it will prompt version otherwise Command Not Found

Does overflow:hidden applied to <body> work on iPhone Safari?

Had this issue today on iOS 8 & 9 and it seems that we now need to add height: 100%;

So add

html,
body {
  position: relative;
  height: 100%;
  overflow: hidden;
}

Check if a div does NOT exist with javascript

getElementById returns null if there is no such element.

Run Function After Delay

$(document).ready(function() {

  // place this within dom ready function
  function showpanel() {     
    $(".navigation").hide();
    $(".page").children(".panel").fadeIn(1000);
 }

 // use setTimeout() to execute
 setTimeout(showpanel, 1000)

});

For more see here

Selectors in Objective-C?

As per apple docs: https://developer.apple.com/library/archive/documentation/General/Conceptual/DevPedia-CocoaCore/Selector.html

A selector is the name used to select a method to execute for an object, or the unique identifier that replaces the name when the source code is compiled. A selector by itself doesn’t do anything. It simply identifies a method. The only thing that makes the selector method name different from a plain string is that the compiler makes sure that selectors are unique. What makes a selector useful is that (in conjunction with the runtime) it acts like a dynamic function pointer that, for a given name, automatically points to the implementation of a method appropriate for whichever class it’s used with. Suppose you had a selector for the method run, and classes Dog, Athlete, and ComputerSimulation (each of which implemented a method run). The selector could be used with an instance of each of the classes to invoke its run method—even though the implementation might be different for each.

Example: (lldb) breakpoint --set selector viewDidLoad

This will set a breakpoint on all viewDidLoad implementations in your app. So selector is kind of a global identifier for a method.

What's the difference between "super()" and "super(props)" in React when using es6 classes?

When implementing the constructor() function inside a React component, super() is a requirement. Keep in mind that your MyComponent component is extending or borrowing functionality from the React.Component base class.

This base class has a constructor() function of its own that has some code inside of it, to setup our React component for us.

When we define a constructor() function inside our MyComponent class, we are essentially, overriding or replacing the constructor() function that is inside the React.Component class, but we still need to ensure that all the setup code inside of this constructor() function still gets called.

So to ensure that the React.Component’s constructor() function gets called, we call super(props). super(props) is a reference to the parents constructor() function, that’s all it is.

We have to add super(props) every single time we define a constructor() function inside a class-based component.

If we don’t we will see an error saying that we have to call super(props).

The entire reason for defining this constructor() funciton is to initialize our state object.

So in order to initialize our state object, underneath the super call I am going to write:

class App extends React.Component {
  constructor(props) {
      super(props);

      this.state = {};
   }

  // React says we have to define render()
  render() {
    return <div>Hello world</div>;
  }
};

So we have defined our constructor() method, initialized our state object by creating a JavaScript object, assigning a property or key/value pair to it, assigning the result of that to this.state. Now of course this is just an example here so I have not really assigned a key/value pair to the state object, its just an empty object.

Get URL of ASP.Net Page in code-behind

Use this:

Request.Url.AbsoluteUri

That will get you the full path (including http://...)

Cannot find module cv2 when using OpenCV

I have come accross same as this problem i installed cv2 by

pip install cv2

However when i import cv2 module it displayed no module named cv2 error.
Then i searched and find cv2.pyd files in my computer and i copy and paste to site-packages directory

C:\Python27\Lib\site-packages

then i closed and reopened existing application, it worked.

EDIT I will tell how to install cv2 correctly.

1. Firstly install numpy on your computer by

pip install numpy

2. Download opencv from internet (almost 266 mb).
I download opencv-2.4.12.exe for python 2.7. Then install this opencv-2.4.12.exe file.
I extracted to C:\Users\harun\Downloads to this folder.
After installation go look for cv2.py into the folders.
For me

C:\Users\harun\Downloads\opencv\build\python\2.7\x64

in this folder take thecv2.pyd and copy it in to the

C:\Python27\Lib\site-packages

now you can able to use cv2 in you python scripts.

remove item from array using its name / value

You can do it with _.pullAllBy.

_x000D_

var countries = {};_x000D_
_x000D_
countries.results = [_x000D_
    {id:'AF',name:'Afghanistan'},_x000D_
    {id:'AL',name:'Albania'},_x000D_
    {id:'DZ',name:'Algeria'}_x000D_
];_x000D_
_x000D_
// Remove element by id_x000D_
_.pullAllBy(countries.results , [{ 'id': 'AL' }], 'id');_x000D_
_x000D_
// Remove element by name_x000D_
// _.pullAllBy(countries.results , [{ 'name': 'Albania' }], 'name');_x000D_
console.log(countries);

_x000D_

.as-console-wrapper {_x000D_
  max-height: 100% !important;_x000D_
  top: 0;_x000D_
}

_x000D_

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>_x000D_
<script src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.11/lodash.min.js"></script>

_x000D_

How can I make a div not larger than its contents?

I've a span inside a div and just setting margin: auto to the container div worked for me.

Max retries exceeded with URL in requests

i wasn't able to make it work on windows even after installing pyopenssl and trying various python versions (while it worked fine on mac), so i switched to urllib and it works on python 3.6 (from python .org) and 3.7 (anaconda)

import urllib 
from urllib.request import urlopen
html = urlopen("http://pythonscraping.com/pages/page1.html")
contents = html.read()
print(contents)

Connect to docker container as user other than root

You can run a shell in a running docker container using a command like:

docker exec -it --user root <container id> /bin/bash

How to delete a column from a table in MySQL

You can use

alter table <tblname> drop column <colname>

javascript date + 7 days

_x000D_

var future = new Date(); // get today date_x000D_
future.setDate(future.getDate() + 7); // add 7 days_x000D_
var finalDate = future.getFullYear() +'-'+ ((future.getMonth() + 1) < 10 ? '0' : '') + (future.getMonth() + 1) +'-'+ future.getDate();_x000D_
console.log(finalDate);

_x000D_

default select option as blank

I understand what you are trying to do.The best and the most successful way is :

<select name='department' required>
   <option value="">None</option>
   <option value="Teaching">Teaching department</option>
   <option value="nonTeaching">Non-teaching department</option> 
</select>

How to force a WPF binding to refresh?

MultiBinding friendly version...

private void ComboBox_Loaded(object sender, RoutedEventArgs e)
{
    BindingOperations.GetBindingExpressionBase((ComboBox)sender, ComboBox.ItemsSourceProperty).UpdateTarget();
}

Parse JSON file using GSON

One thing that to be remembered while solving such problems is that in JSON file, a { indicates a JSONObject and a [ indicates JSONArray. If one could manage them properly, it would be very easy to accomplish the task of parsing the JSON file. The above code was really very helpful for me and I hope this content adds some meaning to the above code.

The Gson JsonReader documentation explains how to handle parsing of JsonObjects and JsonArrays:

Within array handling methods, first call beginArray() to consume the array's opening bracket. Then create a while loop that accumulates values, terminating when hasNext() is false. Finally, read the array's closing bracket by calling endArray().

Within object handling methods, first call beginObject() to consume the object's opening brace. Then create a while loop that assigns values to local variables based on their name. This loop should terminate when hasNext() is false. Finally, read the object's closing brace by calling endObject().

CSS class for pointer cursor

As of June 2020, adding role='button' to any HTML tag would add cursor: "pointer" to the element styling.

<span role="button">Non-button element button</span>

Official discussion on this feature - https://github.com/twbs/bootstrap/issues/23709

Documentation link - https://getbootstrap.com/docs/4.5/content/reboot/#pointers-on-buttons

How to save data file into .RData?

There are three ways to save objects from your R session:

Saving all objects in your R session:

The save.image() function will save all objects currently in your R session:

save.image(file="1.RData")

These objects can then be loaded back into a new R session using the load() function:

load(file="1.RData")

Saving some objects in your R session:

If you want to save some, but not all objects, you can use the save() function:

save(city, country, file="1.RData")

Again, these can be reloaded into another R session using the load() function:

load(file="1.RData")

Saving a single object

If you want to save a single object you can use the saveRDS() function:

saveRDS(city, file="city.rds")
saveRDS(country, file="country.rds")

You can load these into your R session using the readRDS() function, but you will need to assign the result into a the desired variable:

city <- readRDS("city.rds")
country <- readRDS("country.rds")

But this also means you can give these objects new variable names if needed (i.e. if those variables already exist in your new R session but contain different objects):

city_list <- readRDS("city.rds")
country_vector <- readRDS("country.rds")

How to fix error "Updating Maven Project". Unsupported IClasspathEntry kind=4?

I tried all the steps mentioned here and on similar questions but couldn't solve this problem. I could neither solve problem nor update my m2eclipse. So I installed Eclipse Luna and it solved my problem... though it mean that I had to spend about 45 min to configure all the environment in my workspace.

Python - Get path of root project structure

I used the ../ method to fetch the current project path.

Example: Project1 -- D:\projects

src

ConfigurationFiles

Configuration.cfg

Path="../src/ConfigurationFiles/Configuration.cfg"

How to install Google Play Services in a Genymotion VM (with no drag and drop support)?

Download the latest version of genymotion and after creating a device click on Open GAPP in device right side.

That work for me

How to pass data from child component to its parent in ReactJS?

I found the approach how to get data from child component in parents when i need it.

Parent:

class ParentComponent extends Component{
  onSubmit(data) {
    let mapPoint = this.getMapPoint();
  }

  render(){
    return (
      <form onSubmit={this.onSubmit.bind(this)}>
        <ChildComponent getCurrentPoint={getMapPoint => {this.getMapPoint = getMapPoint}} />
        <input type="submit" value="Submit" />
      </form>
    )
  }
}

Child:

class ChildComponent extends Component{
  constructor(props){
    super(props);

    if (props.getCurrentPoint){
      props.getCurrentPoint(this.getMapPoint.bind(this));
    }
  }

  getMapPoint(){
    return this.Point;
  }
}

This example showing how to pass function from child component to parent and use this function to get data from child.

How to read data From *.CSV file using javascript?

Don't split on commas -- it won't work for most CSV files, and this question has wayyyy too many views for the asker's kind of input data to apply to everyone. Parsing CSV is kind of scary since there's no truly official standard, and lots of delimited text writers don't consider edge cases.

This question is old, but I believe there's a better solution now that Papa Parse is available. It's a library I wrote, with help from contributors, that parses CSV text or files. It's the only JS library I know of that supports files gigabytes in size. It also handles malformed input gracefully.

1 GB file parsed in 1 minute: Parsed 1 GB file in 1 minute

(Update: With Papa Parse 4, the same file took only about 30 seconds in Firefox. Papa Parse 4 is now the fastest known CSV parser for the browser.)

Parsing text is very easy:

var data = Papa.parse(csvString);

Parsing files is also easy:

Papa.parse(file, {
    complete: function(results) {
        console.log(results);
    }
});

Streaming files is similar (here's an example that streams a remote file):

Papa.parse("http://example.com/bigfoo.csv", {
    download: true,
    step: function(row) {
        console.log("Row:", row.data);
    },
    complete: function() {
        console.log("All done!");
    }
});

If your web page locks up during parsing, Papa can use web workers to keep your web site reactive.

Papa can auto-detect delimiters and match values up with header columns, if a header row is present. It can also turn numeric values into actual number types. It appropriately parses line breaks and quotes and other weird situations, and even handles malformed input as robustly as possible. I've drawn on inspiration from existing libraries to make Papa, so props to other JS implementations.

Access restriction on class due to restriction on required library rt.jar?

There's another solution that also works.

Go to the Build Path settings in the project properties.
Remove the JRE System Library
Add it back; Select "Add Library" and select the JRE System Library. The default worked for me.

This works because you have multiple classes in different jar files. Removing and re-adding the JRE lib will make the right classes be first. If you want a fundamental solution make sure you exclude the jar files with the same classes.

For me I have: javax.xml.soap.SOAPPart in three different jars: axis-saaj-1.4.jar, saaj-api-1.3.jar and the rt.jar

How can I cast int to enum?

Sometimes you have an object to the MyEnum type. Like

var MyEnumType = typeof(MyEnum);

Then:

Enum.ToObject(typeof(MyEnum), 3)

Serialize and Deserialize Json and Json Array in Unity

IF you are using Vector3 this is what i did

1- I create a class Name it Player

using System;
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
[Serializable]
public class Player
{
    public Vector3[] Position;

}

2- then i call it like this

if ( _ispressed == true)
        {
            Player playerInstance = new Player();
            playerInstance.Position = newPos;
            string jsonData = JsonUtility.ToJson(playerInstance);

            reference.Child("Position" + Random.Range(0, 1000000)).SetRawJsonValueAsync(jsonData);
            Debug.Log(jsonData);
            _ispressed = false;
        }

3- and this is the result

"Position":[ {"x":-2.8567452430725099,"y":-2.4323320388793947,"z":0.0}]}

Angular Material: mat-select not selecting default

Use compareWith, A function to compare the option values with the selected values. see here: https://material.angular.io/components/select/api#MatSelect

For an object of the following structure:

listOfObjs = [{ name: 'john', id: '1'}, { name: 'jimmy', id: '2'},...]

Define markup like this:

<mat-form-field>
  <mat-select
    [compareWith]="compareObjects"
    [(ngModel)]="obj">
       <mat-option  *ngFor="let obj of listOfObjs" [value]="obj">
          {{ obj.name }}
       </mat-option>
    </mat-select>
</mat-form-field>

And define comparison function like this:

compareObjects(o1: any, o2: any): boolean {
  return o1.name === o2.name && o1.id === o2.id;
}

How do I get the HTML code of a web page in PHP?

you can use the DomDocument method to get an individual HTML tag level variable too

$homepage = file_get_contents('https://www.example.com/');
$doc = new DOMDocument;
$doc->loadHTML($homepage);
$titles = $doc->getElementsByTagName('h3');
echo $titles->item(0)->nodeValue;

Spring RestTemplate GET with parameters

Converting of a hash map to a string of query parameters:

Map<String, String> params = new HashMap<>();
params.put("msisdn", msisdn);
params.put("email", email);
params.put("clientVersion", clientVersion);
params.put("clientType", clientType);
params.put("issuerName", issuerName);
params.put("applicationName", applicationName);

UriComponentsBuilder builder = UriComponentsBuilder.fromHttpUrl(url);
for (Map.Entry<String, String> entry : params.entrySet()) {
    builder.queryParam(entry.getKey(), entry.getValue());
}

HttpHeaders headers = new HttpHeaders();
headers.set("Accept", "application/json");

HttpEntity<String> response = restTemplate.exchange(builder.toUriString(), HttpMethod.GET, new HttpEntity(headers), String.class);

AddRange to a Collection

Try casting to List in the extension method before running the loop. That way you can take advantage of the performance of List.AddRange.

public static void AddRange<T>(this ICollection<T> destination,
                               IEnumerable<T> source)
{
    List<T> list = destination as List<T>;

    if (list != null)
    {
        list.AddRange(source);
    }
    else
    {
        foreach (T item in source)
        {
            destination.Add(item);
        }
    }
}

Spring Data JPA and Exists query

Spring Data JPA 1.11 now supports the exists projection in repository query derivation.

See documentation here.

In your case the following will work:

public interface MyEntityRepository extends CrudRepository<MyEntity, String> {  
    boolean existsByFoo(String foo);
}

How do I create a list of random numbers without duplicates?

import random
result=[]
for i in range(1,50):
    rng=random.randint(1,20)
    result.append(rng)

How to check Oracle patches are installed?

I understand the original post is for Oracle 10 but this is for reference by anyone else who finds it via Google.

Under Oracle 12c, I found that that my registry$history is empty. This works instead:

select * from registry$sqlpatch;

MySQL GROUP BY two columns

First, let's make some test data:

create table client (client_id integer not null primary key auto_increment,
                     name varchar(64));
create table portfolio (portfolio_id integer not null primary key auto_increment,
                        client_id integer references client.id,
                        cash decimal(10,2),
                        stocks decimal(10,2));
insert into client (name) values ('John Doe'), ('Jane Doe');
insert into portfolio (client_id, cash, stocks) values (1, 11.11, 22.22),
                                                       (1, 10.11, 23.22),
                                                       (2, 30.30, 40.40),
                                                       (2, 40.40, 50.50);

If you didn't need the portfolio ID, it would be easy:

select client_id, name, max(cash + stocks)
from client join portfolio using (client_id)
group by client_id

+-----------+----------+--------------------+
| client_id | name     | max(cash + stocks) |
+-----------+----------+--------------------+
|         1 | John Doe |              33.33 | 
|         2 | Jane Doe |              90.90 | 
+-----------+----------+--------------------+

Since you need the portfolio ID, things get more complicated. Let's do it in steps. First, we'll write a subquery that returns the maximal portfolio value for each client:

select client_id, max(cash + stocks) as maxtotal
from portfolio
group by client_id

+-----------+----------+
| client_id | maxtotal |
+-----------+----------+
|         1 |    33.33 | 
|         2 |    90.90 | 
+-----------+----------+

Then we'll query the portfolio table, but use a join to the previous subquery in order to keep only those portfolios the total value of which is the maximal for the client:

 select portfolio_id, cash + stocks from portfolio 
 join (select client_id, max(cash + stocks) as maxtotal 
       from portfolio
       group by client_id) as maxima
 using (client_id)
 where cash + stocks = maxtotal

+--------------+---------------+
| portfolio_id | cash + stocks |
+--------------+---------------+
|            5 |         33.33 | 
|            6 |         33.33 | 
|            8 |         90.90 | 
+--------------+---------------+

Finally, we can join to the client table (as you did) in order to include the name of each client:

select client_id, name, portfolio_id, cash + stocks
from client
join portfolio using (client_id)
join (select client_id, max(cash + stocks) as maxtotal
      from portfolio 
      group by client_id) as maxima
using (client_id)
where cash + stocks = maxtotal

+-----------+----------+--------------+---------------+
| client_id | name     | portfolio_id | cash + stocks |
+-----------+----------+--------------+---------------+
|         1 | John Doe |            5 |         33.33 | 
|         1 | John Doe |            6 |         33.33 | 
|         2 | Jane Doe |            8 |         90.90 | 
+-----------+----------+--------------+---------------+

Note that this returns two rows for John Doe because he has two portfolios with the exact same total value. To avoid this and pick an arbitrary top portfolio, tag on a GROUP BY clause:

select client_id, name, portfolio_id, cash + stocks
from client
join portfolio using (client_id)
join (select client_id, max(cash + stocks) as maxtotal
      from portfolio 
      group by client_id) as maxima
using (client_id)
where cash + stocks = maxtotal
group by client_id, cash + stocks

+-----------+----------+--------------+---------------+
| client_id | name     | portfolio_id | cash + stocks |
+-----------+----------+--------------+---------------+
|         1 | John Doe |            5 |         33.33 | 
|         2 | Jane Doe |            8 |         90.90 | 
+-----------+----------+--------------+---------------+

How does OAuth 2 protect against things like replay attacks using the Security Token?

Here is perhaps the simplest explanation of how OAuth2 works for all 4 grant types, i.e., 4 different flows where the app can acquire the access token.

Similarity

All grant type flows have 2 parts:

Get access token
Use access token

The 2nd part 'use access token' is the same for all flows

Difference

The 1st part of the flow 'get access token' for each grant type varies.

However, in general the 'get access token' part can be summarized as consisting 5 steps:

Pre-register your app (client) with OAuth provider, e.g., Twitter, etc. to get client id/secret
Create a social login button with client id & required scopes/permissions on your page so when clicked user gets redirected to OAuth provider to be authenticated
OAuth provider request user to grant permission to your app (client)
OAuth provider issues code
App (client) acquires access token

Here is a side-by-side diagram comparing how each grant type flow is different based on the 5 steps.

This diagram is from https://blog.oauth.io/introduction-oauth2-flow-diagrams/

Each have different levels of implementation difficulty, security, and uses cases. Depending on your needs and situation, you will have to use one of them. Which to use?

Client Credential: If your app is only serving a single user

Resource Owner Password Crendential: This should be used only as last resort as the user has to hand over his credentials to the app, which means the app can do everything the user can

Authorization Code: The best way to get user authorization

Implicit: If you app is mobile or single-page app

There is more explanation of the choice here: https://blog.oauth.io/choose-oauth2-flow-grant-types-for-app/

Reading an image file in C/C++

Check this thread out: read and write image file.

Also, have a look at this other question at Stackoverflow.

Run text file as commands in Bash

You can use something like this:

for i in `cat foo.txt`
do
    sudo $i
done

Though if the commands have arguments (i.e. there is whitespace in the lines) you may have to monkey around with that a bit to protect the whitepace so that the whole string is seen by sudo as a command. But it gives you an idea on how to start.

How to loop in excel without VBA or macros?

The way to get the results of your formula would be to start in a new sheet.

In cell A1 put the formula

=IF('testsheet'!C1 <= 99,'testsheet'!A1,"")

Copy that cell down to row 40 In cell B1 put the formula

=A1

In cell B2 put the formula

=B1 & A2

Copy that cell down to row 40.

The value you want is now in that column in row 40.

Not really the answer you want, but that is the fastest way to get things done excel wise without creating a custom formula that takes in a range and makes the calculation (which would be more fun to do).

How do synchronized static methods work in Java and can I use it for loading Hibernate entities?

Why do you want to enforce that only a single thread can access the DB at any one time?

It is the job of the database driver to implement any necessary locking, assuming a Connection is only used by one thread at a time!

Most likely, your database is perfectly capable of handling multiple, parallel access

Parse Error: Adjacent JSX elements must be wrapped in an enclosing tag

For Rect-Native developers. I encounter this error while renderingItem in FlatList. I had two Text components. I was using them like below

renderItem = { ({item}) => 
     <Text style = {styles.item}>{item.key}</Text>
     <Text style = {styles.item}>{item.user}</Text>
}

But after I put these tow Inside View Components it worked for me.

renderItem = { ({item}) => 
   <View style={styles.flatview}>
      <Text style = {styles.item}>{item.key}</Text>
      <Text style = {styles.item}>{item.user}</Text>
   </View>
 }

You might be using other components but putting them into View may be worked for you.

Plotting power spectrum in python

From the numpy fft page http://docs.scipy.org/doc/numpy/reference/routines.fft.html:

When the input a is a time-domain signal and A = fft(a), np.abs(A) is its amplitude spectrum and np.abs(A)**2 is its power spectrum. The phase spectrum is obtained by np.angle(A).

Why doesn't list have safe "get" method like dictionary?

Ultimately it probably doesn't have a safe .get method because a dict is an associative collection (values are associated with names) where it is inefficient to check if a key is present (and return its value) without throwing an exception, while it is super trivial to avoid exceptions accessing list elements (as the len method is very fast). The .get method allows you to query the value associated with a name, not directly access the 37th item in the dictionary (which would be more like what you're asking of your list).

Of course, you can easily implement this yourself:

def safe_list_get (l, idx, default):
  try:
    return l[idx]
  except IndexError:
    return default

You could even monkeypatch it onto the __builtins__.list constructor in __main__, but that would be a less pervasive change since most code doesn't use it. If you just wanted to use this with lists created by your own code you could simply subclass list and add the get method.

Show a child form in the centre of Parent form in C#

On the SubLogin Form I would expose a SetLocation method so that you can set it from your parent form:

public class SubLogin : Form
{
   public void SetLocation(Point p)
   {
      this.Location = p;
   }
}

Then, from your main form:

loginForm = new SubLogin();   
Point p = //do math to get point
loginForm.SetLocation(p);
loginForm.Show();

Formatting dates on X axis in ggplot2

Can you use date as a factor?

Yes, but you probably shouldn't.

...or should you use as.Date on a date column?

Yes.

Which leads us to this:

library(scales)
df$Month <- as.Date(df$Month)
ggplot(df, aes(x = Month, y = AvgVisits)) + 
  geom_bar(stat = "identity") +
  theme_bw() +
  labs(x = "Month", y = "Average Visits per User") +
  scale_x_date(labels = date_format("%m-%Y"))

enter image description here

in which I've added stat = "identity" to your geom_bar call.

In addition, the message about the binwidth wasn't an error. An error will actually say "Error" in it, and similarly a warning will always say "Warning" in it. Otherwise it's just a message.

How to make a section of an image a clickable link

If you don't want to make the button a separate image, you can use the <area> tag. This is done by using html similar to this:

<img src="imgsrc" width="imgwidth" height="imgheight" alt="alttext" usemap="#mapname">

<map name="mapname">
    <area shape="rect" coords="see note 1" href="link" alt="alttext">
</map>

Note 1: The coords=" " attribute must be formatted in this way: coords="x1,y1,x2,y2" where:

x1=top left X coordinate
y1=top left Y coordinate
x2=bottom right X coordinate
y2=bottom right Y coordinate

Note 2: The usemap="#mapname" attribute must include the #.

EDIT:

I looked at your code and added in the <map> and <area> tags where they should be. I also commented out some parts that were either overlapping the image or seemed there for no use.

<div class="flexslider">
    <ul class="slides" runat="server" id="Ul">                             
        <li class="flex-active-slide" style="background: url(&quot;images/slider-bg-1.jpg&quot;) no-repeat scroll 50% 0px transparent; width: 100%; float: left; margin-right: -100%; position: relative; display: list-item;">
            <div class="container">
                <div class="sixteen columns contain"></div>   
                <img runat="server" id="imgSlide1" style="top: 1px; right: -19px; opacity: 1;" class="item" src="./test.png" data-topimage="7%" height="358" width="728" usemap="#imgmap" />
                <map name="imgmap">
                    <area shape="rect" coords="48,341,294,275" href="http://www.example.com/">
                </map>
                <!--<a href="#" style="display:block; background:#00F; width:356px; height:66px; position:absolute; left:1px; top:-19px; left: 162px; top: 279px;"></a>-->
            </div>
        </li>
    </ul>
</div>
<!-- <ul class="flex-direction-nav">
    <li><a class="flex-prev" href="#"><i class="icon-angle-left"></i></a></li>
    <li><a class="flex-next" href="#"><i class="icon-angle-right"></i></a></li>
</ul> -->

Notes:

The coord="48,341,294,275" is in reference to your screenshot you posted.
The src="./test.png" is the location and name of the screenshot you posted on my computer.
The href="http://www.example.com/" is an example link.

How do you perform address validation?

For us-based address data my company has used GeoStan. It has bindings for C and Java (and we created a Perl binding). Note that it is a commercial product and isn't cheap. It is quite fast though (~300 addresses per second) and offers features like CASS certification (USPS bulk mail discount), DPV (Delivery point verification) flagging, and LON/LAT geocoding.

There is a Perl module Geo::PostalAddress, but it uses heuristics and doesn't have the other features mentioned for GeoStan.

Edit: some have mentioned 'doing it yourself', if you do decide to do this, a good source of information to start with is the US Census Tiger Data Set, which contains a lot of information about the US including address information.

Check if a value exists in pandas dataframe index

df = pandas.DataFrame({'g':[1]}, index=['isStop'])

#df.loc['g']

if 'g' in df.index:
    print("find g")

if 'isStop' in df.index:
    print("find a")

How to read/process command line arguments?

Yet another option is argh. It builds on argparse, and lets you write things like:

import argh

# declaring:

def echo(text):
    "Returns given word as is."
    return text

def greet(name, greeting='Hello'):
    "Greets the user with given name. The greeting is customizable."
    return greeting + ', ' + name

# assembling:

parser = argh.ArghParser()
parser.add_commands([echo, greet])

# dispatching:

if __name__ == '__main__':
    parser.dispatch()

It will automatically generate help and so on, and you can use decorators to provide extra guidance on how the arg-parsing should work.

How to get the previous page URL using JavaScript?

You want in page A to know the URL of page B?

Or to know in page B the URL of page A?

In Page B: document.referrer if set. As already shown here: How to get the previous URL in JavaScript?

In page A you would need to read a cookie or local/sessionStorage you set in page B, assuming the same domains

How to disable action bar permanently

Heres a quick solution.

You find styles.xml and you change the base application theme to "Theme.AppCompat.NoActionBar" as shown below.

<style name="AppTheme" parent="Theme.AppCompat.NoActionBar">
    <!-- Customize your theme here. -->
</style>

Escape dot in a regex range

If you using JavaScript to test your Regex, try \\. instead of \..

It acts on the same way because JS remove first backslash.

C# referencing a variable from another method

Amazon S3 direct file upload from client browser - private key disclosure

You're saying you want a "serverless" solution. But that means you have no ability to put any of "your" code in the loop. (NOTE: Once you give your code to a client, it's "their" code now.) Locking down CORS is not going to help: People can easily write a non-web-based tool (or a web-based proxy) that adds the correct CORS header to abuse your system.

The big problem is that you can't differentiate between the different users. You can't allow one user to list/access his files, but prevent others from doing so. If you detect abuse, there is nothing you can do about it except change the key. (Which the attacker can presumably just get again.)

Your best bet is to create an "IAM user" with a key for your javascript client. Only give it write access to just one bucket. (but ideally, do not enable the ListBucket operation, that will make it more attractive to attackers.)

If you had a server (even a simple micro instance at $20/month), you could sign the keys on your server while monitoring/preventing abuse in realtime. Without a server, the best you can do is periodically monitor for abuse after-the-fact. Here's what I would do:

1) periodically rotate the keys for that IAM user: Every night, generate a new key for that IAM user, and replace the oldest key. Since there are 2 keys, each key will be valid for 2 days.

2) enable S3 logging, and download the logs every hour. Set alerts on "too many uploads" and "too many downloads". You will want to check both total file size and number of files uploaded. And you will want to monitor both the global totals, and also the per-IP address totals (with a lower threshold).

These checks can be done "serverless" because you can run them on your desktop. (i.e. S3 does all the work, these processes just there to alert you to abuse of your S3 bucket so you don't get a giant AWS bill at the end of the month.)

What are MVP and MVC and what is the difference?

I have used both MVP and MVC and although we as developers tend to focus on the technical differences of both patterns the point for MVP in IMHO is much more related to ease of adoption than anything else.

If I’m working in a team that already as a good background on web forms development style it’s far easier to introduce MVP than MVC. I would say that MVP in this scenario is a quick win.

My experience tells me that moving a team from web forms to MVP and then from MVP to MVC is relatively easy; moving from web forms to MVC is more difficult.

I leave here a link to a series of articles a friend of mine has published about MVP and MVC.

http://www.qsoft.be/post/Building-the-MVP-StoreFront-Gutthrie-style.aspx

How do you force Visual Studio to regenerate the .designer files for aspx/ascx files?

I recently saw that I was having the same problem. Visual Studio 2010 was refusing to update the designer file.

As it turns out, VS doesn't modify the designer file for a page that uses CodeFile (run off of pages) instead of CodeBehind (DLL). This is true no matter how many times you close VS, reload the project, re-create the control(s), or modify a file. Nothing would prompt VS to regenerate the designer. It's as if it doesn't create the designer file for CodeFile pages but does require it to be there.

I changed it to CodeBehind and saved the page. The designer file updated immediately. Then I just changed it back and everything was still golden. This behavior seems to be new with VS 2010 / .NET 4.0 as VS 2008 by default didn't suffer from this.

It's this part:

<%@ Page Language="vb" AutoEventWireup="false" CodeFile="YourPage.aspx.vb" Inherits="YourPageClass" %>

Change CodeFile to CodeBehind, save, and then revert.

PHP code is not being executed, instead code shows on the page

If you have configuration like this:

<VirtualHost *:80>
    ServerName example.com
    DocumentRoot "/var/www/example.com"

    <FilesMatch "\.php$">
        SetHandler "proxy:fcgi://127.0.0.1:9000"
    </FilesMatch>
</VirtualHost>

Uncomment next lines in your httpd.conf

LoadModule proxy_module lib/httpd/modules/mod_proxy.so
LoadModule proxy_fcgi_module lib/httpd/modules/mod_proxy_fcgi.so

It works for me

How to use su command over adb shell?

for my use case, i wanted to grab the SHA1 hash from the magisk config file. the below worked for me.

adb shell "su -c "cat /sbin/.magisk/config | grep SHA | awk -F= '{ print $2 }'""

get launchable activity name of package from adb

Since Android 7.0 you can use adb shell cmd package resolve-activity command to get the default activity of an installed app like this:

adb shell "cmd package resolve-activity --brief com.google.android.calculator | tail -n 1"
com.google.android.calculator/com.android.calculator2.Calculator

How to hide a TemplateField column in a GridView

For Each dcfColumn As DataControlField In gvGridview.Columns
    If dcfColumn.HeaderText = "ColumnHeaderText" Then
        dcfColumn.Visible = false                    
    End If
Next

What is null in Java?

Null is not an instance of any class.

However, you can assign null to variables of any (object or array) type:

 // this is false   
 boolean nope = (null instanceof String);

 // but you can still use it as a String
 String x = null;
 "abc".startsWith(null);

Nth max salary in Oracle

5th highest salary:

SELECT
    * 
FROM
    emp a 
WHERE 
    4 = (
        SELECT 
            COUNT(DISTINCT b.sal) 
        FROM 
            emp b 
        WHERE 
            a.sal < b.sal
    )

Replace 4 with any value of N.

Eclipse can't find / load main class

It is possible to have 2 groovy-xxx-all.jar files by excample in lib directory. which makes that an app is not running

Changing color of Twitter bootstrap Nav-Pills

The most voted solution did not work for me.(Bootstrap 3.0.0) However, this did:

.nav-pills > li.active > a, .nav-pills > li.active > a:hover, .nav-pills > li.active > a:focus {
    color:black;
    background-color:#fcd900;
    }

including this on the page <style></style> tags serves for the per page basis well

and mixing it on two shades gives a brilliant effect like:

<style>
    .nav-pills > li.active > a, .nav-pills > li.active > a:focus {
        color: black;
        background-color: #fcd900;
    }

        .nav-pills > li.active > a:hover {
            background-color: #efcb00;
            color:black;
        }
</style>

How do I add files and folders into GitHub repos?

When adding a directory to github check that the directory does not contain a .git file using "ls -a" if it does remove it. .git files in a directory will cause problems when you are trying to add a that directory in git

Chrome - ERR_CACHE_MISS

This is a known issue in Chrome and resolved in latest versions. Please refer https://bugs.chromium.org/p/chromium/issues/detail?id=942440 for more details.

Import regular CSS file in SCSS file?

It is now possible using:

@import 'CSS:directory/filename.css';

Unix epoch time to Java Date object

long timestamp = Long.parseLong(date)
Date expiry = new Date(timestamp * 1000)

Is there a way to force npm to generate package-lock.json?

As several answer explained the you should run:

npm i

BUT if it does not solve...

Check the version of your npm executable. (For me it was 3.x.x which doesn't uses the package-lock.json (at all))

npm -v

It should be at least 5.x.x (which introduced the package-lock.json file.)

To update npm on Linux, follow these instructions.

For more details about package files, please read this medium story.

How to set the background image of a html 5 canvas to .png image

You can give the background image in css :

#canvas { background:url(example.jpg) }

it will show you canvas back ground image

Get Character value from KeyCode in JavaScript... then trim

You can also use the read-only property key. It also respects special keys like shift etc. and is supported by IE9.

When a non-printable or special character is pressed, the value will be on of the defined key values like 'Shift' or 'Multiply'.

Keyboard event.key
X -> 'x'
Shift+X -> 'X'
F5 -> 'F5'

Install Visual Studio 2013 on Windows 7

Visual Studio 2013 System Requirements

Supported Operating Systems:

Windows 8.1 (x86 and x64)

Windows 8 (x86 and x64)

Windows 7 SP1 (x86 and x64)

Windows Server 2012 R2 (x64)

Windows Server 2012 (x64)

Windows Server 2008 R2 SP1 (x64)

Hardware requirements:

1.6 GHz or faster processor

1 GB of RAM (1.5 GB if running on a virtual machine)

20 GB of available hard disk space

5400 RPM hard disk drive

DirectX 9-capable video card that runs at 1024 x 768 or higher display resolution

Additional Requirements for the laptop:

Internet Explorer 10

KB2883200 (available through Windows Update) is required

And don't forget to reboot after updating your windows

Progress Bar with HTML and CSS

If you wish to have a progress bar without adding some code PACE can be an awesome tool for you.

Just include pace.js and a CSS theme of your choice, and you get a beautiful progress indicator for your page load and AJAX navigation. Best thing with PACE is the auto detection of progress.

It contains various themes and color schemes as well.

Worth a try.

Unix command to find lines common in two files

perl -ne 'print if ($seen{$_} .= @ARGV) =~ /10$/'  file1 file2

Block Comments in a Shell Script

Another mode is: If your editor HAS NO BLOCK comment option,

Open a second instance of the editor (for example File=>New File...)
From THE PREVIOUS file you are working on, select ONLY THE PART YOU WANT COMMENT
Copy and paste it in the window of the new temporary file...
Open the Edit menu, select REPLACE and input as string to be replaced '\n'
input as replace string: '\n#'
press the button 'replace ALL'

DONE

it WORKS with ANY editor

Public free web services for testing soap client

There is a bunch on here:

http://www.webservicex.net/WS/wscatlist.aspx

Just google for "Free WebService" or "Open WebService" and you'll find tons of open SOAP endpoints.

Remember, you can get a WSDL from any ASMX endpoint by adding ?WSDL to the url.

Change the URL in the browser without loading the new page using JavaScript

With HTML 5, use the history.pushState function. As an example:

<script type="text/javascript">
var stateObj = { foo: "bar" };
function change_my_url()
{
   history.pushState(stateObj, "page 2", "bar.html");
}
var link = document.getElementById('click');
link.addEventListener('click', change_my_url, false);
</script>

and a href:

<a href="#" id='click'>Click to change url to bar.html</a>

If you want to change the URL without adding an entry to the back button list, use history.replaceState instead.

How to get response from S3 getObject in Node.js?

For someone looking for a NEST JS TYPESCRIPT version of the above:

    /**
     * to fetch a signed URL of a file
     * @param key key of the file to be fetched
     * @param bucket name of the bucket containing the file
     */
    public getFileUrl(key: string, bucket?: string): Promise<string> {
        var scopeBucket: string = bucket ? bucket : this.defaultBucket;
        var params: any = {
            Bucket: scopeBucket,
            Key: key,
            Expires: signatureTimeout  // const value: 30
        };
        return this.account.getSignedUrlPromise(getSignedUrlObject, params);
    }

    /**
     * to get the downloadable file buffer of the file
     * @param key key of the file to be fetched
     * @param bucket name of the bucket containing the file
     */
    public async getFileBuffer(key: string, bucket?: string): Promise<Buffer> {
        var scopeBucket: string = bucket ? bucket : this.defaultBucket;
        var params: GetObjectRequest = {
            Bucket: scopeBucket,
            Key: key
        };
        var fileObject: GetObjectOutput = await this.account.getObject(params).promise();
        return Buffer.from(fileObject.Body.toString());
    }

    /**
     * to upload a file stream onto AWS S3
     * @param stream file buffer to be uploaded
     * @param key key of the file to be uploaded
     * @param bucket name of the bucket 
     */
    public async saveFile(file: Buffer, key: string, bucket?: string): Promise<any> {
        var scopeBucket: string = bucket ? bucket : this.defaultBucket;
        var params: any = {
            Body: file,
            Bucket: scopeBucket,
            Key: key,
            ACL: 'private'
        };
        var uploaded: any = await this.account.upload(params).promise();
        if (uploaded && uploaded.Location && uploaded.Bucket === scopeBucket && uploaded.Key === key)
            return uploaded;
        else {
            throw new HttpException("Error occurred while uploading a file stream", HttpStatus.BAD_REQUEST);
        }
    }

Using :: in C++

You're pretty much right about cout and cin. They are objects (not functions) defined inside the std namespace. Here are their declarations as defined by the C++ standard:

Header <iostream> synopsis

#include <ios>
#include <streambuf>
#include <istream>
#include <ostream>

namespace std {
  extern istream cin;
  extern ostream cout;
  extern ostream cerr;
  extern ostream clog;

  extern wistream wcin;
  extern wostream wcout;
  extern wostream wcerr;
  extern wostream wclog;
}

:: is known as the scope resolution operator. The names cout and cin are defined within std, so we have to qualify their names with std::.

Classes behave a little like namespaces in that the names declared inside the class belong to the class. For example:

class foo
{
  public:
    foo();
    void bar();
};

The constructor named foo is a member of the class named foo. They have the same name because its the constructor. The function bar is also a member of foo.

Because they are members of foo, when referring to them from outside the class, we have to qualify their names. After all, they belong to that class. So if you're going to define the constructor and bar outside the class, you need to do it like so:

foo::foo()
{
  // Implement the constructor
}

void foo::bar()
{
  // Implement bar
}

This is because they are being defined outside the class. If you had not put the foo:: qualification on the names, you would be defining some new functions in the global scope, rather than as members of foo. For example, this is entirely different bar:

void bar()
{
  // Implement different bar
}

It's allowed to have the same name as the function in the foo class because it's in a different scope. This bar is in the global scope, whereas the other bar belonged to the foo class.

Could not open a connection to your authentication agent

Here is the solution I came up with when using PowerShell.

Add the below function to your Microsoft.PowerShell_profile.ps1

function RunSsh($userIdentity ) {
   $agent=ssh-agent
   $position=$agent[0].IndexOf("=")
   $ending=$agent[0].IndexOf(";")

   $variableStartPosition=$agent[0].IndexOf("export")
   $variableEndPosition=$agent[0].LastIndexOf(";")
   $variableName=$agent[0].Substring($variableStartPosition+7,$variableEndPosition-$variableStartPosition-7)
   [Environment]::SetEnvironmentVariable($variableName, $agent[0].Substring($position+1,$ending-$position-1))

   $position=$agent[1].IndexOf("=")
   $ending=$agent[1].IndexOf(";")

   $variableStartPosition=$agent[1].IndexOf("export")
   $variableEndPosition=$agent[1].LastIndexOf(";")
   $variableName=$agent[1].Substring($variableStartPosition+7,$variableEndPosition-$variableStartPosition-7)
   [Environment]::SetEnvironmentVariable($variableName, $agent[1].Substring($position+1,$ending-$position-1))

   if($userIdentity.Length -eq 0) {
      ssh-add
   } else {
      ssh-add $userIdentity
   }
}

Now from the command line you can run RunSsh which uses identity file in ~\.ssh folder or pass in the identity file with RunSsh C:\ssh\id_rsa where C:\ssh\id_rsa is your identity file.

For this to work you need to have ssh-add and ssh-agent in your path environment variable.

post ajax data to PHP and return data

For the JS, try

data: {id: the_id}
...
success: function(data) {
        alert('the server returned ' + data;
    }

and

$the_id = intval($_POST['id']);

in PHP

Remove header and footer from window.print()

If you happen to scroll down to this point, I found a solution for Firefox. It will print contents from a specific div without the footers and headers. You can customize as you wish.

Firstly, download and install this addon : JSPrintSetup.

Secondly, write this function:

<script>
function PrintElem(elem)
{
    var mywindow = window.open('', 'PRINT', 'height=400,width=600');
    mywindow.document.write('<html><head><title>' + document.title  + '</title>');
    mywindow.document.write('</head><body >');
    mywindow.document.write(elem);
    mywindow.document.write('</body></html>');
    mywindow.document.close(); // necessary for IE >= 10
    mywindow.focus(); // necessary for IE >= 10*/

   //jsPrintSetup.setPrinter('PDFCreator'); //set the printer if you wish
   jsPrintSetup.setSilentPrint(1);

   //sent empty page header
   jsPrintSetup.setOption('headerStrLeft', '');
   jsPrintSetup.setOption('headerStrCenter', '');
   jsPrintSetup.setOption('headerStrRight', '');

   // set empty page footer
   jsPrintSetup.setOption('footerStrLeft', '');
   jsPrintSetup.setOption('footerStrCenter', '');
   jsPrintSetup.setOption('footerStrRight', '');

   // print my window silently. 
   jsPrintSetup.printWindow(mywindow);
   jsPrintSetup.setSilentPrint(1); //change to 0 if you want print dialog

    mywindow.close();

    return true;
}
</script>

Thirdly, In your code, wherever you want to write the print code, do this (I have used JQuery. You can use plain javascript):

<script>
$("#print").click(function () {
    var contents = $("#yourDivToPrint").html();
    PrintElem(contents);
})
</script>

Obviously, you need the link to click:

<a href="#" id="print">Print my Div</a>

And your div to print:

<div id="yourDivToPrint">....</div>

CodeIgniter: 404 Page Not Found on Live Server

I had the same problem. Changing controlers first letter to uppercase helped.

PHP send mail to multiple email addresses

Following code will do the task....

<?php

$contacts = array(
"[email protected]",
"[email protected]",
//....as many email address as you need
);

foreach($contacts as $contact) {

$to      =  $contact;
$subject = 'the subject';
$message = 'hello';
mail($to, $subject, $message, $headers);

}

?>

Preferred way of getting the selected item of a JComboBox

Note this isn't at heart a question about JComboBox, but about any collection that can include multiple types of objects. The same could be said for "How do I get a String out of a List?" or "How do I get a String out of an Object[]?"

Optimal way to Read an Excel file (.xls/.xlsx)

Read from excel, modify and write back

 /// <summary>
/// /Reads an excel file and converts it into dataset with each sheet as each table of the dataset
/// </summary>
/// <param name="filename"></param>
/// <param name="headers">If set to true the first row will be considered as headers</param>
/// <returns></returns>
public DataSet Import(string filename, bool headers = true)
{
    var _xl = new Excel.Application();
    var wb = _xl.Workbooks.Open(filename);
    var sheets = wb.Sheets;
    DataSet dataSet = null;
    if (sheets != null && sheets.Count != 0)
    {
        dataSet = new DataSet();
        foreach (var item in sheets)
        {
            var sheet = (Excel.Worksheet)item;
            DataTable dt = null;
            if (sheet != null)
            {
                dt = new DataTable();
                var ColumnCount = ((Excel.Range)sheet.UsedRange.Rows[1, Type.Missing]).Columns.Count;
                var rowCount = ((Excel.Range)sheet.UsedRange.Columns[1, Type.Missing]).Rows.Count;

                for (int j = 0; j < ColumnCount; j++)
                {
                    var cell = (Excel.Range)sheet.Cells[1, j + 1];
                    var column = new DataColumn(headers ? cell.Value : string.Empty);
                    dt.Columns.Add(column);
                }

                for (int i = 0; i < rowCount; i++)
                {
                    var r = dt.NewRow();
                    for (int j = 0; j < ColumnCount; j++)
                    {
                        var cell = (Excel.Range)sheet.Cells[i + 1 + (headers ? 1 : 0), j + 1];
                        r[j] = cell.Value;
                    }
                    dt.Rows.Add(r);
                }

            }
            dataSet.Tables.Add(dt);
        }
    }
    _xl.Quit();
    return dataSet;
}



 public string Export(DataTable dt, bool headers = false)
    {
        var wb = _xl.Workbooks.Add();
        var sheet = (Excel.Worksheet)wb.ActiveSheet;
        //process columns
        for (int i = 0; i < dt.Columns.Count; i++)
        {
            var col = dt.Columns[i];
            //added columns to the top of sheet
            var currentCell = (Excel.Range)sheet.Cells[1, i + 1];
            currentCell.Value = col.ToString();
            currentCell.Font.Bold = true;
            //process rows
            for (int j = 0; j < dt.Rows.Count; j++)
            {
                var row = dt.Rows[j];
                //added rows to sheet
                var cell = (Excel.Range)sheet.Cells[j + 1 + 1, i + 1];
                cell.Value = row[i];
            }
            currentCell.EntireColumn.AutoFit();
        }
        var fileName="{somepath/somefile.xlsx}";
        wb.SaveCopyAs(fileName);
        _xl.Quit();
        return fileName;
    }

Return value using String result=Command.ExecuteScalar() error occurs when result returns null

You can use like the following

string result = null;
object value = cmd.ExecuteScalar();
 if (value != null)
 {
    result = value.ToString();
 }     
 conn.Close();
return result;

apt-get for Cygwin?

No. The only officially supported tool for downloading and updating Cygwin packages is the setup.exe file you used for the initial install, although that can be invoked with command line arguments to help the process.

From that same page:

The basic reason for not having a more full-featured package manager is that such a program would need full access to all of Cygwin's POSIX functionality. That is, however, difficult to provide in a Cygwin-free environment, such as exists on first installation. Additionally, Windows does not easily allow overwriting of in-use executables so installing a new version of the Cygwin DLL while a package manager is using the DLL is problematic.

How to download all dependencies and packages to directory

This will download all packages and dependencies (no already installed) to a directory of your choice:

sudo apt-get install -d -o Dir::Cache=/path-to/directory/apt/cache -o Dir::State::Lists=/path-to/directory/apt/lists packages

Make sure /path-to/directory/apt/cache and /path-to/directory/apt/lists exist. If you don't set -o Dir::Cache it points to /var/cache/apt, Dir::State::Lists points to /var/lib/apt/lists (which keeps the index files of available packages)

Both -o options can be used with update and upgrade instead of install.

On different machine run the same command without '-d'

Spring Boot - How to log all requests and responses with exceptions in single place?

Has there been any development with Actuator HTTP Trace since the initial question was posted i.e. is there a way to enrich it with the response body?

What about enriching it with custom metadata from MDC or from Spring-Sleuth or Zipkin, such as traceId and spanId?

Also for me Actuator HTTP Trace didn't work Spring Boot 2.2.3, and I found the fix here: https://juplo.de/actuator-httptrace-does-not-work-with-spring-boot-2-2/

pom.xml

<dependency>
  <groupId>org.springframework.boot
  <artifactId>spring-boot-starter-actuator
</dependency>

application.properties

management.endpoints.web.exposure.include=httptrace

The fix:

The simple fix for this problem is, to add a @Bean of type InMemoryHttpTraceRepository to your @Configuration-class:

@Bean
public HttpTraceRepository htttpTraceRepository()
{
  return new InMemoryHttpTraceRepository();
}

The Explanation:

The cause of this problem is not a bug, but a legitimate change in the default configuration. Unfortunately, this change is not noted in the according section of the documentation. Instead it is burried in the Upgrade Notes for Spring Boot 2.2

The default-implementation stores the captured data in memory. Hence, it consumes much memory, without the user knowing, or even worse: needing it. This is especially undesirable in cluster environments, where memory is a precious good. And remember: Spring Boot was invented to simplify cluster deployments!

That is, why this feature is now turned of by default and has to be turned on by the user explicitly, if needed.

How to provide password to a command that prompts for one in bash?

Simply use :

echo "password" | sudo -S mount -t vfat /dev/sda1 /media/usb/;
if [ $? -eq 0 ]; then
    echo -e '[ ok ] Usb key mounted'
else
    echo -e '[warn] The USB key is not mounted'
fi

This code is working for me, and its in /etc/init.d/myscriptbash.sh

multiple where condition codeigniter

it's late for this answer but i think maybe still can help, i try the both methods above, using two where conditions and the method with the array, none of those work for me i did several test and the condition was never getting executed, so i did a workaround, here is my code:

public function validateLogin($email, $password){
        $password = md5($password);
        $this->db->select("userID,email,password");
        $query = $this->db->get_where("users", array("email" => $email));
        $p = $query->row_array();

        if($query->num_rows() == 1 && $password == $p['password']){  
            return $query->row();
        }

    }

How to use glob() to find files recursively?

import os
import fnmatch


def recursive_glob(treeroot, pattern):
    results = []
    for base, dirs, files in os.walk(treeroot):
        goodfiles = fnmatch.filter(files, pattern)
        results.extend(os.path.join(base, f) for f in goodfiles)
    return results

fnmatch gives you exactly the same patterns as glob, so this is really an excellent replacement for glob.glob with very close semantics. An iterative version (e.g. a generator), IOW a replacement for glob.iglob, is a trivial adaptation (just yield the intermediate results as you go, instead of extending a single results list to return at the end).

jQuery select by attribute using AND and OR operators

First find the condition that occurs in all situations, then filter the special conditions:

$('[myc="blue"]')
    .filter('[myid="1"],[myid="3"]');

How to create batch file in Windows using "start" with a path and command with spaces

Surrounding the path and the argument with spaces inside quotes as in your example should do. The command may need to handle the quotes when the parameters are passed to it, but it usually is not a big deal.

How to escape double quotes in JSON

To escape backslashes that cause problems for JSON data I use this function.

//escape backslash to avoid errors
var escapeJSON = function(str) {
    return str.replace(/\\/g,'\\');
};

Reload .profile in bash shell script (in unix)?

The bash script runs in a separate subshell. In order to make this work you will need to source this other script as well.

How to install mysql-connector via pip

If loading via pip install mysql-connector and leads an error Unable to find Protobuf include directory then this would be useful pip install mysql-connector==2.1.4

mysql-connector is obsolete, so use pip install mysql-connector-python. Same here

Node - was compiled against a different Node.js version using NODE_MODULE_VERSION 51

Simply run:

npm uninstall bcrypt

Followed by:

npm install bcrypt (or npm install, if bcrypt is declared as dependency in your package.json file)

How can I convert an Integer to localized month name in Java?

Kotlin Extension

fun Int.toMonthName(): String {
    return DateFormatSymbols().months[this]
}

Usage

calendar.get(Calendar.MONTH).toMonthName()

Pure CSS to make font-size responsive based on dynamic amount of characters

Create a lookup table that computes font-size based on the length of the string inside your <div>.

const fontSizeLookupTable = () => {
  // lookup table looks like: [ '72px', ..., '32px', ..., '16px', ..., ]
  let a = [];
  // adjust this based on how many characters you expect in your <div>
  a.length = 32;
  // adjust the following ranges empirically
  a.fill( '72px' ,     );
  a.fill( '32px' , 4 , );
  a.fill( '16px' , 8 , );
  // add more ranges as necessary
  return a;
}

const computeFontSize = stringLength => {
  const table = fontSizeLookupTable();
  return stringLength < table.length ? table[stringLength] : '16px';
}

Adjust and tune all parameters by empirical test.

Android YouTube app Play Video Intent

You can also just grab the WebViewClient

wvClient = new WebViewClient() {
@Override
public boolean shouldOverrideUrlLoading(WebView view, String url) {
  if (url.startsWith("youtube:")) {
    String youtubeUrl = "http://www.youtube.com/watch?v="
    + url.Replace("youtube:", "");
  startActivity(new Intent(Intent.ACTION_VIEW, Uri.parse(youtubeUrl)));
}
return false;
}

Worked fine in my app.

Open Jquery modal dialog on click event

try

$(document).ready(function () {
    //$('#dialog').dialog(); 
    $('#dialog_link').click(function () {
        $('#dialog').dialog('open');
        return false;
    });
});

there is a open arg in the last part

HTML-parser on Node.js

Try https://github.com/tmpvar/jsdom - you give it some HTML and it gives you a DOM.

Drop-down menu that opens up/upward with pure css

If we are use chosen dropdown list, then we can use below css(No JS/JQuery require)

<select chosen="{width: '100%'}" ng- 
   model="modelName" class="form-control input- 
   sm"
   ng- 
   options="persons.persons as 
   persons.persons for persons in 
   jsonData"
   ng- 
   change="anyFunction(anyParam)" 
   required>
   <option value=""> </option>
</select>
<style>   
.chosen-container .chosen-drop {
    border-bottom: 0;
    border-top: 1px solid #aaa;
    top: auto;
    bottom: 40px;
}

.chosen-container.chosen-with-drop .chosen-single {
    border-top-left-radius: 0px;
    border-top-right-radius: 0px;

    border-bottom-left-radius: 5px;
    border-bottom-right-radius: 5px;

    background-image: none;
}

.chosen-container.chosen-with-drop .chosen-drop {
    border-bottom-left-radius: 0px;
    border-bottom-right-radius: 0px;

    border-top-left-radius: 5px;
    border-top-right-radius: 5px;

    box-shadow: none;

    margin-bottom: -16px;
}
</style>

What's the scope of a variable initialized in an if statement?

Yes. It is also true for for scope. But not functions of course.

In your example: if the condition in the if statement is false, x will not be defined though.

Android: Create spinner programmatically from array

This actually worked for me

    Spinner spinner = new Spinner(this);
    ArrayAdapter<String> spinnerArrayAdapter = new ArrayAdapter<String>(
            this, android.R.layout.simple_spinner_item, spinnerArray);
    spinnerArrayAdapter.setDropDownViewResource( android.R.layout.simple_spinner_dropdown_item );

    spinner = (Spinner) findViewById( R.id.spinner );
    spinner.setAdapter(spinnerArrayAdapter);

How to convert a PIL Image into a numpy array?

You're not saying how exactly putdata() is not behaving. I'm assuming you're doing

>>> pic.putdata(a)
Traceback (most recent call last):
  File "...blablabla.../PIL/Image.py", line 1185, in putdata
    self.im.putdata(data, scale, offset)
SystemError: new style getargs format but argument is not a tuple

This is because putdata expects a sequence of tuples and you're giving it a numpy array. This

>>> data = list(tuple(pixel) for pixel in pix)
>>> pic.putdata(data)

will work but it is very slow.

As of PIL 1.1.6, the "proper" way to convert between images and numpy arrays is simply

>>> pix = numpy.array(pic)

although the resulting array is in a different format than yours (3-d array or rows/columns/rgb in this case).

Then, after you make your changes to the array, you should be able to do either pic.putdata(pix) or create a new image with Image.fromarray(pix).

What is the C++ function to raise a number to a power?

First add #include <cmath> then you can use pow methode in your code for example :

pow(3.5, 3);

Which 3.5 is base and 3 is exp

How to check iOS version?

#define IsIOS8 (NSFoundationVersionNumber > NSFoundationVersionNumber_iOS_7_1)

Insert at first position of a list in Python

Use insert:

In [1]: ls = [1,2,3]

In [2]: ls.insert(0, "new")

In [3]: ls
Out[3]: ['new', 1, 2, 3]

Windows batch script launch program and exit console

start "" "%SystemRoot%\Notepad.exe"

Keep the "" in between start and your application path.

Added explanation:

Normally when we launch a program from a batch file like below, we'll have the black windows at the background like OP said.

%SystemRoot%\Notepad.exe

This was cause by Notepad running in same command prompt (process). The command prompt will close AFTER notepad is closed. To avoid that, we can use the start command to start a separate process like this.

start %SystemRoot%\Notepad.exe

This command is fine as long it doesn't has space in the path. To handle space in the path for just in case, we added the " quotes like this.

start "%SystemRoot%\Notepad.exe"

However running this command would just start another blank command prompt. Why? If you lookup to the start /?, the start command will recognize the argument between the " as the title of the new command prompt it is going to launch. So, to solve that, we have the command like this:

start "" "%SystemRoot%\Notepad.exe"

The first argument of "" is to set the title (which we set as blank), and the second argument of "%SystemRoot%\Notepad.exe" is the target command to run (that support spaces in the path).

If you need to add parameters to the command, just append them quoted, i.e.:

start "" "%SystemRoot%\Notepad.exe" "<filename>"

C++ convert string to hexadecimal and vice versa

This will convert "Hello World" to "48656c6c6f20576f726c64" and will store this hex value in str1 and also will convert "48656c6c6f20576f726c64" to "Hello World".

#include <iostream>
#include<sstream>

using namespace std;
int hexCharToInt(char);
string hexToString(string);
int main()
{
    std::string str;
    std::stringstream str1;

    str="Hello World";
    for(int i=0;i<str.length();i++){
        str1 << std::hex << (int)str.at(i);
    }
    std::cout << str1.str() <<"\n";
    string test = "48656c6c6f20576f726c64";
    std::cout << hexToString(test) <<"\n";
    return 0;
}
string hexToString(string str){
    std::stringstream HexString;
    for(int i=0;i<str.length();i++){
        char a = str.at(i++);
        char b = str.at(i);
        int x = hexCharToInt(a);
        int y = hexCharToInt(b);
        HexString << (char)((16*x)+y);
    }
    return HexString.str();
}

int hexCharToInt(char a){
    if(a>='0' && a<='9')
        return(a-48);
    else if(a>='A' && a<='Z')
        return(a-55);
    else
        return(a-87);
}

Cannot call getSupportFragmentManager() from activity

get current activity from parent, then using this code

getActivity().getSupportFragmentManager()

How do I check for vowels in JavaScript?

cycles, arrays, regexp... for what? It can be much quicker :)

function isVowel(char)
{
    return char === 'a' || char === 'e' || char === 'i' || char === 'o' || char === 'u' || false;
}

Passing an array of data as an input parameter to an Oracle procedure

If the types of the parameters are all the same (varchar2 for example), you can have a package like this which will do the following:

CREATE OR REPLACE PACKAGE testuser.test_pkg IS

   TYPE assoc_array_varchar2_t IS TABLE OF VARCHAR2(4000) INDEX BY BINARY_INTEGER;

   PROCEDURE your_proc(p_parm IN assoc_array_varchar2_t);

END test_pkg;

CREATE OR REPLACE PACKAGE BODY testuser.test_pkg IS

   PROCEDURE your_proc(p_parm IN assoc_array_varchar2_t) AS
   BEGIN
      FOR i IN p_parm.first .. p_parm.last
      LOOP
         dbms_output.put_line(p_parm(i));
      END LOOP;

   END;

END test_pkg;

Then, to call it you'd need to set up the array and pass it:

DECLARE
  l_array testuser.test_pkg.assoc_array_varchar2_t;
BEGIN
  l_array(0) := 'hello';
  l_array(1) := 'there';  

  testuser.test_pkg.your_proc(l_array);
END;
/

How can I get a specific parameter from location.search?

This question is old and things have evolved in JavaScript. You can now do this:

const params = {}
document.location.search.substr(1).split('&').forEach(pair => {
  [key, value] = pair.split('=')
  params[key] = value
})

and you get params.year that contains 2008. You would also get other query params in your params object.

Edit: a shorter/cleaner way to do this:

const params = new Map(location.search.slice(1).split('&').map(kv => kv.split('=')))

You can then test if the year param exists with:

params.has('year')  // true

Or retrieve it with:

params.get('year')  // 2008

Edit 2020

You can convert URL params to an Object:

const params = location.search.slice(1).split('&').reduce((acc, s) => {
  const [k, v] = s.split('=')
  return Object.assign(acc, {[k]: v})
}, {})

Then it can be used as a regular JS Object:

params.year  // 2008

How to create empty constructor for data class in Kotlin Android

Non-empty secondary constructor for data class in Kotlin:

data class ChemicalElement(var name: String,
                           var symbol: String,
                           var atomicNumber: Int,
                           var atomicWeight: Double,
                           var nobleMetal: Boolean?) {

    constructor(): this("Silver",
                        "Ag", 
                        47,
                        107.8682,
                        true)
}

fun main() {
    var chemicalElement = ChemicalElement()
    println("RESULT: ${chemicalElement.symbol} means ${chemicalElement.name}")
    println(chemicalElement)
}

// RESULT: Ag means Silver
// ChemicalElement(name=Silver, symbol=Ag, atomicNumber=47, atomicWeight=107.8682, nobleMetal=true)

Empty secondary constructor for data class in Kotlin:

data class ChemicalElement(var name: String,
                           var symbol: String,
                           var atomicNumber: Int,
                           var atomicWeight: Double,
                           var nobleMetal: Boolean?) {

    constructor(): this("",
                        "", 
                        -1,
                        0.0,
                        null)
}

fun main() {
    var chemicalElement = ChemicalElement()
    println(chemicalElement)
}

// ChemicalElement(name=, symbol=, atomicNumber=-1, atomicWeight=0.0, nobleMetal=null)

How can I clone an SQL Server database on the same server in SQL Server 2008 Express?

You could just create a new database and then go to tasks, import data, and import all the data from the database you want to duplicate to the database you just created.

Declaring a custom android UI element using XML

Great reference. Thanks! An addition to it:

If you happen to have a library project included which has declared custom attributes for a custom view, you have to declare your project namespace, not the library one's. Eg:

Given that the library has the package "com.example.library.customview" and the working project has the package "com.example.customview", then:

Will not work (shows the error " error: No resource identifier found for attribute 'newAttr' in package 'com.example.library.customview'" ):

<com.library.CustomView
        xmlns:android="http://schemas.android.com/apk/res/android"
        xmlns:app="http://schemas.android.com/apk/res/com.example.library.customview"
        android:id="@+id/myView"
        app:newAttr="value" />

Will work:

<com.library.CustomView
        xmlns:android="http://schemas.android.com/apk/res/android"
        xmlns:app="http://schemas.android.com/apk/res/com.example.customview"
        android:id="@+id/myView"
        app:newAttr="value" />

VS 2017 Git Local Commit DB.lock error on every commit

.vs folder should not be committed.
create a file with name ".gitignore" inside the projects git root directory.
Add the following line ".vs/" in ".gitignore" file.
Now commit your project.

Wait for Angular 2 to load/resolve model before rendering view/template

A nice solution that I've found is to do on UI something like:

<div *ngIf="vendorServicePricing && quantityPricing && service">
 ...Your page...
</div

Only when: vendorServicePricing, quantityPricing and service are loaded the page is rendered.

How do I move focus to next input with jQuery?

var inputs = $('input, select, textarea').keypress(function (e) {
  if (e.which == 13) {
    e.preventDefault();
    var nextInput = inputs.get(inputs.index(this) + 1);
    if (nextInput) {
      nextInput.focus();
    }
  }
});

Sorting Python list based on the length of the string

When you pass a lambda to sort, you need to return an integer, not a boolean. So your code should instead read as follows:

xs.sort(lambda x,y: cmp(len(x), len(y)))

Note that cmp is a builtin function such that cmp(x, y) returns -1 if x is less than y, 0 if x is equal to y, and 1 if x is greater than y.

Of course, you can instead use the key parameter:

xs.sort(key=lambda s: len(s))

This tells the sort method to order based on whatever the key function returns.

EDIT: Thanks to balpha and Ruslan below for pointing out that you can just pass len directly as the key parameter to the function, thus eliminating the need for a lambda:

xs.sort(key=len)

And as Ruslan points out below, you can also use the built-in sorted function rather than the list.sort method, which creates a new list rather than sorting the existing one in-place:

print(sorted(xs, key=len))

Angular 4 checkbox change value

Another approach is to use ngModelChange:

Template:

<input type="checkbox" ngModel (ngModelChange)="onChecked(obj, $event)" />

Controller:

onChecked(obj: any, isChecked: boolean){
  console.log(obj, isChecked); // {}, true || false
}

I prefer this method because here you get the relevant object and true/false values of a checkbox.

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

Have you tried:

$OutputVariable = (Shell command) | Out-String

phpMyAdmin mbstring error

To solve this problem on Linux, you need to recompile your PHP with the --enable-mbstring flag.

Difference between char* and const char*?

The question is what's the difference between

char *name

which points to a constant string literal, and

const char *cname

I.e. given

char *name = "foo";

and

const char *cname = "foo";

There is not much difference between the 2 and both can be seen as correct. Due to the long legacy of C code, the string literals have had a type of char[], not const char[], and there are lots of older code that likewise accept char * instead of const char *, even when they do not modify the arguments.

The principal difference of the 2 in general is that *cname or cname[n] will evaluate to lvalues of type const char, whereas *name or name[n] will evaluate to lvalues of type char, which are modifiable lvalues. A conforming compiler is required to produce a diagnostics message if target of the assignment is not a modifiable lvalue; it need not produce any warning on assignment to lvalues of type char:

name[0] = 'x'; // no diagnostics *needed*
cname[0] = 'x'; // a conforming compiler *must* produce a diagnostic message

The compiler is not required to stop the compilation in either case; it is enough that it produces a warning for the assignment to cname[0]. The resulting program is not a correct program. The behaviour of the construct is undefined. It may crash, or even worse, it might not crash, and might change the string literal in memory.

nginx - client_max_body_size has no effect

Had the same issue that the client_max_body_size directive was ignored.

My silly error was, that I put a file inside /etc/nginx/conf.d which did not end with .conf. Nginx will not load these by default.

Formula px to dp, dp to px android

Below funtions worked well for me across devices.

It is taken from https://gist.github.com/laaptu/7867851

public static float convertPixelsToDp(float px){
    DisplayMetrics metrics = Resources.getSystem().getDisplayMetrics();
    float dp = px / (metrics.densityDpi / 160f);
    return Math.round(dp);
}

public static float convertDpToPixel(float dp){
    DisplayMetrics metrics = Resources.getSystem().getDisplayMetrics();
    float px = dp * (metrics.densityDpi / 160f);
    return Math.round(px);
}

Implementing a slider (SeekBar) in Android

How to implement a SeekBar

Add the SeekBar to your layout

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <TextView
        android:id="@+id/textView"
        android:layout_margin="20dp"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"/>

    <SeekBar
        android:id="@+id/seekBar"
        android:max="100"
        android:progress="50"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"/>

</LinearLayout>

Notes

max is the highest value that the seek bar can go to. The default is 100. The minimum is 0. The xml min value is only available from API 26, but you can just programmatically convert the 0-100 range to whatever you need for earlier versions.
progress is the initial position of the slider dot (called a "thumb").
For a vertical SeekBar use android:rotation="270".

Listen for changes in code

public class MainActivity extends AppCompatActivity {

    TextView tvProgressLabel;

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

        // set a change listener on the SeekBar
        SeekBar seekBar = findViewById(R.id.seekBar);
        seekBar.setOnSeekBarChangeListener(seekBarChangeListener);

        int progress = seekBar.getProgress();
        tvProgressLabel = findViewById(R.id.textView);
        tvProgressLabel.setText("Progress: " + progress);
    }

    SeekBar.OnSeekBarChangeListener seekBarChangeListener = new SeekBar.OnSeekBarChangeListener() {

        @Override
        public void onProgressChanged(SeekBar seekBar, int progress, boolean fromUser) {
            // updated continuously as the user slides the thumb
            tvProgressLabel.setText("Progress: " + progress);
        }

        @Override
        public void onStartTrackingTouch(SeekBar seekBar) {
            // called when the user first touches the SeekBar
        }

        @Override
        public void onStopTrackingTouch(SeekBar seekBar) {
            // called after the user finishes moving the SeekBar
        }
    };
}

Notes

If you don't need to do any updates while the user is moving the seekbar, then you can just update the UI in onStopTrackingTouch.

Pytorch tensor to numpy array

This worked for me:

np_arr = torch_tensor.cpu().detach().numpy()

How to decode a QR-code image in (preferably pure) Python?

The following code works fine with me:

brew install zbar
pip install pyqrcode
pip install pyzbar

For QR code image creation:

import pyqrcode
qr = pyqrcode.create("test1")
qr.png("test1.png", scale=6)

For QR code decoding:

from PIL import Image
from pyzbar.pyzbar import decode
data = decode(Image.open('test1.png'))
print(data)

that prints the result:

[Decoded(data=b'test1', type='QRCODE', rect=Rect(left=24, top=24, width=126, height=126), polygon=[Point(x=24, y=24), Point(x=24, y=150), Point(x=150, y=150), Point(x=150, y=24)])]

Named colors in matplotlib

In addition to BoshWash's answer, here is the picture generated by his code:

Named colors

Javascript replace with reference to matched group?

"hello _there_".replace(/_(.*?)_/, function(a, b){
    return '<div>' + b + '</div>';
})

Oh, or you could also:

"hello _there_".replace(/_(.*?)_/, "<div>$1</div>")

EDIT by Liran H: For six other people including myself, $1 did not work, whereas \1 did.

Error: getaddrinfo ENOTFOUND in nodejs for get call

When I tried to install a new ionic app, I got the same error as follows, I tried many sources and found the mistake made in User Environment and System Environment unnecessarily included the PROXY value. I removed the ```user variables http://host:port PROXY

system Variables http_proxy http://username:password@host:port ```` and now it is working fine without trouble.

[ERROR] Network connectivity error occurred, are you offline?

        If you are behind a firewall and need to configure proxy settings, see: https://ion.link/cli-proxy-docs

        Error: getaddrinfo ENOTFOUND host host:80

delete vs delete[] operators in C++

This the basic usage of allocate/DE-allocate pattern in c++ malloc/free, new/delete, new[]/delete[]

We need to use them correspondingly. But I would like to add this particular understanding for the difference between delete and delete[]

1) delete is used to de-allocate memory allocated for single object

2) delete[] is used to de-allocate memory allocated for array of objects

class ABC{}

ABC *ptr = new ABC[100]

when we say new ABC[100], compiler can get the information about how many objects that needs to be allocated(here it is 100) and will call the constructor for each of the objects created

but correspondingly if we simply use delete ptr for this case, compiler will not know how many objects that ptr is pointing to and will end up calling of destructor and deleting memory for only 1 object(leaving the invocation of destructors and deallocation of remaining 99 objects). Hence there will be a memory leak.

so we need to use delete [] ptr in this case.

How to get current date in 'YYYY-MM-DD' format in ASP.NET?

<%: DateTime.Today.ToShortDateString() %>

How to delete a folder in C++?

If you are using windows, then take a look at this link. Otherwise, you may look for your OS specific version api. I don't think C++ comes with a cross-platform way to do it. At the end, it's NOT C++'s work, it's the OS's work.

How do I clear the content of a div using JavaScript?

You can do it the DOM way as well:

var div = document.getElementById('cart_item');
while(div.firstChild){
    div.removeChild(div.firstChild);
}

How to get all subsets of a set? (powerset)

I just wanted to provide the most comprehensible solution, the anti code-golf version.

from itertools import combinations

l = ["x", "y", "z", ]

def powerset(items):
    combo = []
    for r in range(len(items) + 1):
        #use a list to coerce a actual list from the combinations generator
        combo.append(list(combinations(items,r)))
    return combo

l_powerset = powerset(l)

for i, item in enumerate(l_powerset):
    print "All sets of length ", i
    print item

The results

All sets of length 0

[()]

All sets of length 1

[('x',), ('y',), ('z',)]

All sets of length 2

[('x', 'y'), ('x', 'z'), ('y', 'z')]

All sets of length 3

[('x', 'y', 'z')]

For more see the itertools docs, also the wikipedia entry on power sets

"Cannot start compilation: the output path is not specified for module..."

You just have to go to your Module settings > Project and specify a "Project compiler output" and make your modules inherit from project. (For that go to Modules > Paths > Inherit project.

This did the trick for me.

Custom thread pool in Java 8 parallel stream

If you don't mind using a third-party library, with cyclops-react you can mix sequential and parallel Streams within the same pipeline and provide custom ForkJoinPools. For example

 ReactiveSeq.range(1, 1_000_000)
            .foldParallel(new ForkJoinPool(10),
                          s->s.filter(i->true)
                              .peek(i->System.out.println("Thread " + Thread.currentThread().getId()))
                              .max(Comparator.naturalOrder()));

Or if we wished to continue processing within a sequential Stream

 ReactiveSeq.range(1, 1_000_000)
            .parallel(new ForkJoinPool(10),
                      s->s.filter(i->true)
                          .peek(i->System.out.println("Thread " + Thread.currentThread().getId())))
            .map(this::processSequentially)
            .forEach(System.out::println);

[Disclosure I am the lead developer of cyclops-react]

MySQL Results as comma separated list

Instead of using group concat() you can use just concat()

Select concat(Col1, ',', Col2) as Foo_Bar from Table1;

edit this only works in mySQL; Oracle concat only accepts two arguments. In oracle you can use something like select col1||','||col2||','||col3 as foobar from table1; in sql server you would use + instead of pipes.

Configure cron job to run every 15 minutes on Jenkins

It should be,

*/15 * * * *  your_command_or_whatever

How can I remove a character from a string using JavaScript?

The following function worked best for my case:

public static cut(value: string, cutStart: number, cutEnd: number): string {
    return value.substring(0, cutStart) + value.substring(cutEnd + 1, value.length);
}

How to truncate the time on a DateTime object in Python?

What does truncate mean?

You have full control over the formatting by using the strftime() method and using an appropriate format string.

http://docs.python.org/library/datetime.html#strftime-strptime-behavior

How do we download a blob url video

If you can NOT find the .m3u8 file you will need to do a couple of steps different.

1) Go to the network tab and sort by Media

Sort by media

2) You will see something here and select the first item. In my example, it's an mpd file. then copy the Request URL.

3) Next, download the file using your favorite command line tool using the URL from step 2.

youtube-dl -f bestvideo+bestaudio https://url.com/destination/stream.mpd

4) Depending on the encoding you might have to join the audio and video files together but this will depend on a video by video case.

How can I create a link to a local file on a locally-run web page?

Janky at best

<a href="file://///server/folders/x/x/filename.ext">right click </a></td>

and then right click, select "copy location" option, and then paste into url.

how to increase MaxReceivedMessageSize when calling a WCF from C#

You need to set basicHttpBinding -> MaxReceivedMessageSize in the client configuration.

how to inherit Constructor from super class to sub class

Constructors are not inherited, you must create a new, identically prototyped constructor in the subclass that maps to its matching constructor in the superclass.

Here is an example of how this works:

class Foo {
    Foo(String str) { }
}

class Bar extends Foo {
    Bar(String str) {
        // Here I am explicitly calling the superclass 
        // constructor - since constructors are not inherited
        // you must chain them like this.
        super(str);
    }
}

IPC performance: Named Pipe vs Socket

Keep in mind that sockets does not necessarily mean IP (and TCP or UDP). You can also use UNIX sockets (PF_UNIX), which offer a noticeable performance improvement over connecting to 127.0.0.1

SQL Query To Obtain Value that Occurs more than once

From Oracle (but works in most SQL DBs):

SELECT LASTNAME, COUNT(*)
FROM STUDENTS
GROUP BY LASTNAME
HAVING COUNT(*) >= 3

P.S. it's faster one, because you have no Select withing Select methods here

MongoDB: How to query for records where field is null or not set?

Use:

db.emails.count({sent_at: null})

Which counts all emails whose sent_at property is null or is not set. The above query is same as below.

db.emails.count($or: [
  {sent_at: {$exists: false}},
  {sent_at: null}
])

How to return a file using Web API?

Better to return HttpResponseMessage with StreamContent inside of it.

Here is example:

public HttpResponseMessage GetFile(string id)
{
    if (String.IsNullOrEmpty(id))
        return Request.CreateResponse(HttpStatusCode.BadRequest);

    string fileName;
    string localFilePath;
    int fileSize;

    localFilePath = getFileFromID(id, out fileName, out fileSize);

    HttpResponseMessage response = new HttpResponseMessage(HttpStatusCode.OK);
    response.Content = new StreamContent(new FileStream(localFilePath, FileMode.Open, FileAccess.Read));
    response.Content.Headers.ContentDisposition = new System.Net.Http.Headers.ContentDispositionHeaderValue("attachment");
    response.Content.Headers.ContentDisposition.FileName = fileName;
    response.Content.Headers.ContentType = new MediaTypeHeaderValue("application/pdf");

    return response;
}

UPD from comment by patridge: Should anyone else get here looking to send out a response from a byte array instead of an actual file, you're going to want to use new ByteArrayContent(someData) instead of StreamContent (see here).

How to edit a text file in my terminal

If you are still inside the vi editor, you might be in a different mode from the one you want. Hit ESC a couple of times (until it rings or flashes) and then "i" to enter INSERT mode or "a" to enter APPEND mode (they are the same, just start before or after current character).

If you are back at the command prompt, make sure you can locate the file, then navigate to that directory and perform the mentioned "vi helloWorld.txt". Once you are in the editor, you'll need to check the vi reference to know how to perform the editions you want (you may want to google "vi reference" or "vi cheat sheet").

Once the edition is done, hit ESC again, then type :wq to save your work or :q! to quit without saving.

For quick reference, here you have a text-based cheat sheet.

Dictionary with list of strings as value

A simpler way of doing it is:

var dictionary = list.GroupBy(it => it.Key).ToDictionary(dict => dict.Key, dict => dict.Select(item => item.value).ToList());

How to fix error with xml2-config not found when installing PHP from sources?

I had the same issue when I used a DockerFile. My Docker is based on the php:5.5-apache image.

I got that error when executing the command "RUN docker-php-ext-install soap"

I have solved it by adding the following command to my DockerFile

"RUN apt-get update && apt-get install -y libxml2-dev"

add a temporary column with a value

select field1, field2, 'example' as TempField
from table1

This should work across different SQL implementations.

Access Control Request Headers, is added to header in AJAX request with jQuery

What you saw in Firefox was not the actual request; note that the HTTP method is OPTIONS, not POST. It was actually the 'pre-flight' request that the browser makes to determine whether a cross-domain AJAX request should be allowed:

http://www.w3.org/TR/cors/

The Access-Control-Request-Headers header in the pre-flight request includes the list of headers in the actual request. The server is then expected to report back whether these headers are supported in this context or not, before the browser submits the actual request.

Python Remove last 3 characters of a string

Aren't you performing the operations in the wrong order? You requirement seems to be foo[:-3].replace(" ", "").upper()

Finding square root without using sqrt function?

As I found this question is old and have many answers but I have an answer which is simple and working great..

#define EPSILON 0.0000001 // least minimum value for comparison
double SquareRoot(double _val) {
    double low = 0; 
    double high = _val;
    double mid = 0; 

    while (high - low > EPSILON) {
            mid = low + (high - low) / 2; // finding mid value
            if (mid*mid > _val) {
                high = mid;
            } else {
                low = mid;
            }    
    }   
    return mid;
}

I hope it will be helpful for future users.

How to write dynamic variable in Ansible playbook

I am sure there is a smarter way for doing what you want but this should work:

- name         : Test var
  hosts        : all
  gather_facts : no
  vars:
    myvariable : false
  tasks:
    - name: param1
      set_fact:
        myvariable: "{{param1}}"
      when: param1 is defined

    - name: param2
      set_fact:
        myvariable: "{{ param2 if not myvariable else myvariable + ',' + param2 }}"
      when: param2 is defined

    - name: param3
      set_fact:
        myvariable: "{{ param3 if not myvariable else myvariable + ',' + param3 }}"
      when: param3 is defined

    - name: default
      set_fact:
        myvariable: "default"
      when: not myvariable

    - debug:
       var=myvariable

Hope that helps. I am not sure if you can construct variables dynamically and do this in an iterator. But you could also write a small python code or any other language and plug it into ansible

print highest value in dict with key

just :

 mydict = {'A':4,'B':10,'C':0,'D':87}
 max(mydict.items(), key=lambda x: x[1])

Programs & Examples On #Subsonic3

Razor/CSHTML - Any Benefit over what we have?

How to install xgboost in Anaconda Python (Windows platform)?

Is there any way to start with a POST request using Selenium?

SQL: parse the first, middle and last name from a fullname field

How do I check if an object's type is a particular subclass in C++?

How to find the index of an element in an int array?

jquery Ajax call - data parameters are not being passed to MVC Controller action

Create Word Document using PHP in Linux

React Native add bold or italics to single words in <Text> field

How can I convert an image into a Base64 string?

PHP upload image

How do you run a single test/spec file in RSpec?

SQL Error: ORA-00922: missing or invalid option

Matplotlib make tick labels font size smaller

Node.js Web Application examples/tutorials

What is the difference between LATERAL and a subquery in PostgreSQL?

Wait until page is loaded with Selenium WebDriver for Python

readyState

id

staleness_of

Install numpy on python3.3 - Install pip for python3

Converting a factor to numeric without losing information R (as.numeric() doesn't seem to work)

How do I run msbuild from the command line using Windows SDK 7.1?

OnClick Send To Ajax

ImportError: no module named win32api

How to display the string html contents into webbrowser control?

How to get the width and height of an android.widget.ImageView?

Can I inject a service into a directive in AngularJS?

findViewByID returns null

how to add the missing RANDR extension

Find empty or NaN entry in Pandas Dataframe

Determine installed PowerShell version

How to parse JSON in Kotlin?

batch script - run command on each file in directory

Can a PDF file's print dialog be opened with Javascript?

ModelState.AddModelError - How can I add an error that isn't for a property?

How can I display a list view in an Android Alert Dialog?

java.lang.NoClassDefFoundError:failed resolution of :Lorg/apache/http/ProtocolVersion

How to install python developer package?

How can I check if mysql is installed on ubuntu?

Does overflow:hidden applied to <body> work on iPhone Safari?

Check if a div does NOT exist with javascript

Run Function After Delay

Selectors in Objective-C?

What's the difference between "super()" and "super(props)" in React when using es6 classes?

Get URL of ASP.Net Page in code-behind

Cannot find module cv2 when using OpenCV

remove item from array using its name / value

How can I make a div not larger than its contents?

Max retries exceeded with URL in requests

Connect to docker container as user other than root

How to delete a column from a table in MySQL

javascript date + 7 days

default select option as blank

How to force a WPF binding to refresh?

Parse JSON file using GSON

CSS class for pointer cursor

How to save data file into .RData?

Saving all objects in your R session:

Saving some objects in your R session:

Saving a single object

How to fix error "Updating Maven Project". Unsupported IClasspathEntry kind=4?

Python - Get path of root project structure

How to install Google Play Services in a Genymotion VM (with no drag and drop support)?

How to pass data from child component to its parent in ReactJS?

How to read data From *.CSV file using javascript?

Access restriction on class due to restriction on required library rt.jar?

How can I cast int to enum?

Serialize and Deserialize Json and Json Array in Unity

Angular Material: mat-select not selecting default

How do I get the HTML code of a web page in PHP?

Spring RestTemplate GET with parameters

AddRange to a Collection

Spring Data JPA and Exists query

How do I create a list of random numbers without duplicates?

How to check Oracle patches are installed?

MySQL GROUP BY two columns

How does OAuth 2 protect against things like replay attacks using the Security Token?

Reading an image file in C/C++

`id`

`staleness_of`