Programs & Examples On #Implements

`implements` is a keyword in several programming languages used to denote implementation of an interface.

Implements vs extends: When to use? What's the difference?

A class can only "implement" an interface. A class only "extends" a class. Likewise, an interface can extend another interface.

A class can only extend one other class. A class can implement several interfaces.

If instead you are more interested in knowing when to use abstract classes and interfaces, refer to this thread: Interface vs Abstract Class (general OO)

Interface extends another interface but implements its methods

An interface defines behavior. For example, a Vehicle interface might define the move() method.

A Car is a Vehicle, but has additional behavior. For example, the Car interface might define the startEngine() method. Since a Car is also a Vehicle, the Car interface extends the Vehicle interface, and thus defines two methods: move() (inherited) and startEngine().

The Car interface doesn't have any method implementation. If you create a class (Volkswagen) that implements Car, it will have to provide implementations for all the methods of its interface: move() and startEngine().

An interface may not implement any other interface. It can only extend it.

"implements Runnable" vs "extends Thread" in Java

Simple way to say is: If you implement interface that means you are implementing all methods of it and if you extending the class you are inheriting method of your choice... In this case,there is only a one method named Run() so better to implement Runnable interface..

How to put text over images in html?

You can create a div with the exact same size as the image.

<div class="imageContainer">Some Text</div>

use the css background-image property to show the image

 .imageContainer {
       width:200px; 
       height:200px; 
       background-image: url(locationoftheimage);
 }

more here

note: this slichtly tampers the semantics of your document. If needed use javascript to inject the div in the place of a real image.

What are Runtime.getRuntime().totalMemory() and freeMemory()?

Runtime#totalMemory - the memory that the JVM has allocated thus far. This isn't necessarily what is in use or the maximum.

Runtime#maxMemory - the maximum amount of memory that the JVM has been configured to use. Once your process reaches this amount, the JVM will not allocate more and instead GC much more frequently.

Runtime#freeMemory - I'm not sure if this is measured from the max or the portion of the total that is unused. I am guessing it is a measurement of the portion of total which is unused.

Finding Key associated with max Value in a Java Map

int maxValue = 0;
int mKey = 0;
for(Integer key: map.keySet()){
    if(map.get(key) > maxValue){
        maxValue = map.get(key);
        mKey = key;
    }
}
System.out.println("Max Value " + maxValue + " is associated with " + mKey + " key");

IllegalMonitorStateException on wait() call

In order to deal with the IllegalMonitorStateException, you must verify that all invocations of the wait, notify and notifyAll methods are taking place only when the calling thread owns the appropriate monitor. The most simple solution is to enclose these calls inside synchronized blocks. The synchronization object that shall be invoked in the synchronized statement is the one whose monitor must be acquired.

Here is the simple example for to understand the concept of monitor

public class SimpleMonitorState {

    public static void main(String args[]) throws InterruptedException {

        SimpleMonitorState t = new SimpleMonitorState();
        SimpleRunnable m = new SimpleRunnable(t);
        Thread t1 = new Thread(m);
        t1.start();
        t.call();

    }

    public void call() throws InterruptedException {
        synchronized (this) {
            wait();
            System.out.println("Single by Threads ");
        }
    }

}

class SimpleRunnable implements Runnable {

    SimpleMonitorState t;

    SimpleRunnable(SimpleMonitorState t) {
        this.t = t;
    }

    @Override
    public void run() {

        try {
            // Sleep
            Thread.sleep(10000);
            synchronized (this.t) {
                this.t.notify();
            }
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
    }
}

Custom alert and confirm box in jquery

You can use the dialog widget of JQuery UI

http://jqueryui.com/dialog/

What are the benefits to marking a field as `readonly` in C#?

Keep in mind that readonly only applies to the value itself, so if you're using a reference type readonly only protects the reference from being change. The state of the instance is not protected by readonly.

How can I switch to another branch in git?

What worked for me is the following:

Switch to the needed branch:

git checkout -b BranchName

And then I pulled the "master" by:

git pull origin master

How to convert integer into date object python?

I would suggest the following simple approach for conversion:

from datetime import datetime, timedelta
s = "20120213"
# you could also import date instead of datetime and use that.
date = datetime(year=int(s[0:4]), month=int(s[4:6]), day=int(s[6:8]))

For adding/subtracting an arbitary amount of days (seconds work too btw.), you could do the following:

date += timedelta(days=10)
date -= timedelta(days=5)

And convert back using:

s = date.strftime("%Y%m%d")

To convert the integer to a string safely, use:

s = "{0:-08d}".format(i)

This ensures that your string is eight charecters long and left-padded with zeroes, even if the year is smaller than 1000 (negative years could become funny though).

Further reference: datetime objects, timedelta objects

syntax error when using command line in python

Come out of the "python interpreter."

  1. Check out your PATH variable c:\python27
  2. cd and your file location. 3.Now type Python yourfilename.py.

I hope this should work

HttpGet with HTTPS : SSLPeerUnverifiedException

Note: Do not do this in production code, use http instead, or the actual self signed public key as suggested above.

On HttpClient 4.xx:

import static org.junit.Assert.assertEquals;

import java.security.KeyManagementException;
import java.security.NoSuchAlgorithmException;
import java.security.cert.X509Certificate;

import javax.net.ssl.SSLContext;
import javax.net.ssl.TrustManager;
import javax.net.ssl.X509TrustManager;

import org.apache.http.HttpResponse;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.conn.scheme.Scheme;
import org.apache.http.conn.ssl.SSLSocketFactory;
import org.apache.http.impl.client.DefaultHttpClient;
import org.junit.Test;

public class HttpClientTrustingAllCertsTest {

    @Test
    public void shouldAcceptUnsafeCerts() throws Exception {
        DefaultHttpClient httpclient = httpClientTrustingAllSSLCerts();
        HttpGet httpGet = new HttpGet("https://host_with_self_signed_cert");
        HttpResponse response = httpclient.execute( httpGet );
        assertEquals("HTTP/1.1 200 OK", response.getStatusLine().toString());
    }

    private DefaultHttpClient httpClientTrustingAllSSLCerts() throws NoSuchAlgorithmException, KeyManagementException {
        DefaultHttpClient httpclient = new DefaultHttpClient();

        SSLContext sc = SSLContext.getInstance("SSL");
        sc.init(null, getTrustingManager(), new java.security.SecureRandom());

        SSLSocketFactory socketFactory = new SSLSocketFactory(sc);
        Scheme sch = new Scheme("https", 443, socketFactory);
        httpclient.getConnectionManager().getSchemeRegistry().register(sch);
        return httpclient;
    }

    private TrustManager[] getTrustingManager() {
        TrustManager[] trustAllCerts = new TrustManager[] { new X509TrustManager() {
            @Override
            public java.security.cert.X509Certificate[] getAcceptedIssuers() {
                return null;
            }

            @Override
            public void checkClientTrusted(X509Certificate[] certs, String authType) {
                // Do nothing
            }

            @Override
            public void checkServerTrusted(X509Certificate[] certs, String authType) {
                // Do nothing
            }

        } };
        return trustAllCerts;
    }
}

How to change the style of alert box?

I use AlertifyJS to style my dialogues.

_x000D_
_x000D_
alertify.alert('Ready!');_x000D_
alertify.YoutubeDialog || alertify.dialog('YoutubeDialog',function(){_x000D_
    var iframe;_x000D_
    return {_x000D_
        // dialog constructor function, this will be called when the user calls alertify.YoutubeDialog(videoId)_x000D_
        main:function(videoId){_x000D_
            //set the videoId setting and return current instance for chaining._x000D_
            return this.set({ _x000D_
                'videoId': videoId_x000D_
            });_x000D_
        },_x000D_
        // we only want to override two options (padding and overflow)._x000D_
        setup:function(){_x000D_
            return {_x000D_
                options:{_x000D_
                    //disable both padding and overflow control._x000D_
                    padding : !1,_x000D_
                    overflow: !1,_x000D_
                }_x000D_
            };_x000D_
        },_x000D_
        // This will be called once the DOM is ready and will never be invoked again._x000D_
        // Here we create the iframe to embed the video._x000D_
        build:function(){           _x000D_
            // create the iframe element_x000D_
            iframe = document.createElement('iframe');_x000D_
            iframe.frameBorder = "no";_x000D_
            iframe.width = "100%";_x000D_
            iframe.height = "100%";_x000D_
            // add it to the dialog_x000D_
            this.elements.content.appendChild(iframe);_x000D_
_x000D_
            //give the dialog initial height (half the screen height)._x000D_
            this.elements.body.style.minHeight = screen.height * .5 + 'px';_x000D_
        },_x000D_
        // dialog custom settings_x000D_
        settings:{_x000D_
            videoId:undefined_x000D_
        },_x000D_
        // listen and respond to changes in dialog settings._x000D_
        settingUpdated:function(key, oldValue, newValue){_x000D_
            switch(key){_x000D_
               case 'videoId':_x000D_
                    iframe.src = "https://www.youtube.com/embed/" + newValue + "?enablejsapi=1";_x000D_
                break;   _x000D_
            }_x000D_
        },_x000D_
        // listen to internal dialog events._x000D_
        hooks:{_x000D_
            // triggered when the dialog is closed, this is seperate from user defined onclose_x000D_
            onclose: function(){_x000D_
                iframe.contentWindow.postMessage('{"event":"command","func":"pauseVideo","args":""}','*');_x000D_
            },_x000D_
            // triggered when a dialog option gets update._x000D_
            // warning! this will not be triggered for settings updates._x000D_
            onupdate: function(option,oldValue, newValue){_x000D_
                switch(option){_x000D_
                    case 'resizable':_x000D_
                        if(newValue){_x000D_
                            this.elements.content.removeAttribute('style');_x000D_
                            iframe && iframe.removeAttribute('style');_x000D_
                        }else{_x000D_
                            this.elements.content.style.minHeight = 'inherit';_x000D_
                            iframe && (iframe.style.minHeight = 'inherit');_x000D_
                        }_x000D_
                    break;    _x000D_
                }    _x000D_
            }_x000D_
        }_x000D_
    };_x000D_
});_x000D_
//show the dialog_x000D_
alertify.YoutubeDialog('GODhPuM5cEE').set({frameless:true});
_x000D_
<!-- JavaScript -->_x000D_
<script src="//cdn.jsdelivr.net/npm/[email protected]/build/alertify.min.js"></script>_x000D_
<!-- CSS -->_x000D_
<link rel="stylesheet" href="//cdn.jsdelivr.net/npm/[email protected]/build/css/alertify.min.css"/>_x000D_
<!-- Default theme -->_x000D_
<link rel="stylesheet" href="//cdn.jsdelivr.net/npm/[email protected]/build/css/themes/default.min.css"/>_x000D_
<!-- Default theme -->_x000D_
<link rel="stylesheet" href="//cdn.jsdelivr.net/npm/[email protected]/build/css/themes/default.rtl.min.css"/>
_x000D_
_x000D_
_x000D_

No Hibernate Session bound to thread, and configuration does not allow creation of non-transactional one here

I was getting the same the error inside a shared function, but it was only happening for some calls to this shared function. I eventually realized that one of classes calling the shared function wasn't wrapping it inside of a Unit of Work. Once I updated this classes functions with a Unit of Work everything worked as expected.

So just posting this for any future visitors who run into this same error, but for whom the accepted answer doesn't apply.

What's the shebang/hashbang (#!) in Facebook and new Twitter URLs for?

This technique is now deprecated.

This used to tell Google how to index the page.

https://developers.google.com/webmasters/ajax-crawling/

This technique has mostly been supplanted by the ability to use the JavaScript History API that was introduced alongside HTML5. For a URL like www.example.com/ajax.html#!key=value, Google will check the URL www.example.com/ajax.html?_escaped_fragment_=key=value to fetch a non-AJAX version of the contents.

The zip() function in Python 3

The zip() function in Python 3 returns an iterator. That is the reason why when you print test1 you get - <zip object at 0x1007a06c8>. From documentation -

Make an iterator that aggregates elements from each of the iterables.

But once you do - list(test1) - you have exhausted the iterator. So after that anytime you do list(test1) would only result in empty list.

In case of test2, you have already created the list once, test2 is a list, and hence it will always be that list.

Running a command as Administrator using PowerShell?

Another simpler solution is that you may also right click on "C:\Windows\System32\cmd.exe" and choose "Run as Administrator" then you can run any app as administrator without providing any password.

What is the best way to measure execution time of a function?

I would definitely advise you to have a look at System.Diagnostics.Stopwatch

And when I looked around for more about Stopwatch I found this site;

Beware of the stopwatch

There mentioned another possibility

Process.TotalProcessorTime

Change User Agent in UIWebView

The only problem I have found was change user agent only

- (BOOL)application:(UIApplication *)application
        didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
    NSDictionary *dictionary = [NSDictionary 
        dictionaryWithObjectsAndKeys:
        @"Mozilla/5.0 (iPod; U; CPU iPhone OS 4_3_3 like Mac OS X; ja-jp) AppleWebKit/533.17.9 (KHTML, like Gecko) Version/5.0.2 Mobile/8J2 Safari/6533.18.5", 
        @"UserAgent", nil];
    [[NSUserDefaults standardUserDefaults] registerDefaults:dictionary];
}

How to fill background image of an UIView

For Swift 2.1 use this...

    UIGraphicsBeginImageContext(self.view.frame.size)
    UIImage(named: "Cyan.jpg")?.drawInRect(self.view.bounds)

    let image: UIImage! = UIGraphicsGetImageFromCurrentImageContext()

    UIGraphicsEndImageContext()

    self.view.backgroundColor = UIColor(patternImage: image)

ORA-28040: No matching authentication protocol exception

Adding

SQLNET.ALLOWED_LOGON_VERSION_SERVER = 8

is the perfect solution sql.ora directory ..\product\12.1.0\dbhome_1\NETWORK\ADMIN

I cannot start SQL Server browser

I'm trying to setup rf online game to be played offline using MS SQL server 2019 and ended up with the same problem. The SQL Browser service won't start. Almost all answers in this post have been tried but the outcome is disappointing. I've got a weird idea to try start the SQL browser service manually and then change it to automatic after it runs. Luckily it works. So, just simply right click on SQL Server Browser ==> Properties ==>Service==>Start Mode==>Manual. After apply the changes right click on the SQL Server Browser again and start the service. After the service run change the start mode to automatic. Make sure the information provided on log on as: are correct.

How do I convert an array object to a string in PowerShell?

$a = "This", "Is", "a", "cat"

foreach ( $word in $a ) { $sent = "$sent $word" }
$sent = $sent.Substring(1)

Write-Host $sent

Image overlay on responsive sized images bootstrap

When you specify position:absolute it positions itself to the next-highest element with position:relative. In this case, that's the .project div.

If you give the image's immediate parent div a style of position:relative, the overlay will key to that instead of the div which includes the text. For example: http://jsfiddle.net/7gYUU/1/

 <div class="parent">
    <img src="http://placehold.it/500x500" class="img-responsive"/>
    <div class="fa fa-plus project-overlay"></div>
 </div>

.parent {
   position: relative;
}

How to make a <button> in Bootstrap look like a normal link in nav-tabs?

Just make regular link look like button :)

<a href="#" role="button" class="btn btn-success btn-large">Click here!</a>

"role" inside a href code makes it look like button, ofc you can add more variables such as class.

Does swift have a trim method on String?

You can also send characters that you want to be trimed

extension String {


    func trim() -> String {

        return self.trimmingCharacters(in: .whitespacesAndNewlines)

    }

    func trim(characterSet:CharacterSet) -> String {

        return self.trimmingCharacters(in: characterSet)

    }
}

validationMessage = validationMessage.trim(characterSet: CharacterSet(charactersIn: ","))

Minimum and maximum value of z-index?

It depends on the browser (although the latest version of all browsers should max out at 2147483638), as does the browser's reaction when the maximum is exceeded.

http://www.puidokas.com/max-z-index/

MavenError: Failed to execute goal on project: Could not resolve dependencies In Maven Multimodule project

For me, adding the following block of code under <dependency management><dependencies> solved the problem.

<dependency>
    <groupId>org.glassfish</groupId>
    <artifactId>javax.el</artifactId>
    <version>3.0.1-b06</version>
</dependency>

Git pull after forced update

Pull with rebase

A regular pull is fetch + merge, but what you want is fetch + rebase. This is an option with the pull command:

git pull --rebase

VBA Excel sort range by specific column

If the starting cell of the range and of the key is static, the solution can be very simple:

Range("A3").Select
Range(Selection, Selection.End(xlToRight)).Select
Range(Selection, Selection.End(xlDown)).Select
Selection.Sort key1:=Range("B3", Range("B3").End(xlDown)), _
order1:=xlAscending, Header:=xlNo

What is ".NET Core"?

I have found a recent article which I found both short and very good. It covers .NET Standard, .NET Core and .NET Framework and their relationship. I highly recommend it. Unfortunately, I have no time to adapt and put it here.

Original answer content below:


So, based on the latest official entry on the subject, here are some key points as I see them:

.NET Core is essentially a fork of the .NET Framework whose implementation is also optimized around factoring concerns.

We think of .NET Core as not being specific to either .NET Native nor ASP.NET 5 – the BCL and the runtimes are general purpose and designed to be modular. As such, it forms the foundation for all future .NET verticals.

So .NET Native and ASP.NET 5 are just a test "subjects" for new framework configuration, partially this maybe because they are quite different:

Enter image description here

See, they even need separate low-level, but a major part of BCL is still common:

We think of .NET Core as not being specific to either .NET Native nor ASP.NET 5 – the BCL and the runtimes are general purpose and designed to be modular. As such, it forms the foundation for all future .NET verticals.

I.e., magenta rectangles on top will be added massively with new App Models, but the base will remain common.

NuGet deployment:

In contrast to the .NET Framework, the .NET Core platform will be delivered as a set of NuGet packages. We’ve settled on NuGet because that’s where the majority of the library ecosystem already is.

Relationship with current frameworks:

For Visual Studio 2015 our goal is to make sure that .NET Core is a pure subset of the .NET Framework. In other words, there wouldn’t be any feature gaps. After Visual Studio 2015 is released our expectation is that .NET Core will version faster than the .NET Framework. This means that there will be points in time where a feature will only be available on the .NET Core based platforms.

Summary:

The .NET Core platform is a new .NET stack that is optimized for open source development and agile delivery on NuGet. We’re working with the Mono community to make it great on Windows, Linux and Mac, and Microsoft will support it on all three platforms.

We’re retaining the values that the .NET Framework brings to enterprise class development. We’ll offer .NET Core distributions that represent a set of NuGet packages that we tested and support together. Visual Studio remains your one- stop-shop for development. Consuming NuGet packages that are part of a distribution doesn’t require an Internet connection.

Basically this can be thought as a .NET 4.6 with a changed distribution model, which, simultaneously, is being in a process of becoming open source.

How do I disable the security certificate check in Python requests

To add to Blender's answer, you can disable SSL certificate validation for all requests using Session.verify = False

import requests

session = requests.Session()
session.verify = False
session.post(url='https://example.com', data={'bar':'baz'})

Note that urllib3, (which Requests uses), strongly discourages making unverified HTTPS requests and will raise an InsecureRequestWarning.

What is the effect of extern "C" in C++?

It informs the C++ compiler to look up the names of those functions in a C-style when linking, because the names of functions compiled in C and C++ are different during the linking stage.

mysql data directory location

Check where is the root folder of mysql with:

mysql_config

Visual studio equivalent of java System.out

Or, if you want to see output in the Output window of Visual Studio, System.Diagnostics.Debug.WriteLine(stuff)

Summarizing multiple columns with dplyr?

You can simply pass more arguments to summarise:

df %>% group_by(grp) %>% summarise(mean(a), mean(b), mean(c), mean(d))

Source: local data frame [3 x 5]

  grp  mean(a)  mean(b)  mean(c) mean(d)
1   1 2.500000 3.500000 2.000000     3.0
2   2 3.800000 3.200000 3.200000     2.8
3   3 3.666667 3.333333 2.333333     3.0

Simple Pivot Table to Count Unique Values

I usually sort the data by the field I need to do the distinct count of then use IF(A2=A1,0,1); you get then get a 1 in the top row of each group of IDs. Simple and doesn't take any time to calculate on large datasets.

How to insert selected columns from a CSV file to a MySQL database using LOAD DATA INFILE

Load data into a table in MySQL and specify columns:

LOAD DATA LOCAL INFILE 'file.csv' INTO TABLE t1 
FIELDS TERMINATED BY ',' LINES TERMINATED BY '\n'  
(@col1,@col2,@col3,@col4) set name=@col4,id=@col2 ;

@col1,2,3,4 are variables to hold the csv file columns (assume 4 ) name,id are table columns.

Using Auto Layout in UITableView for dynamic cell layouts & variable row heights

An important enough gotcha I just ran into to post as an answer.

@smileyborg's answer is mostly correct. However, if you have any code in the layoutSubviews method of your custom cell class, for instance setting the preferredMaxLayoutWidth, then it won't be run with this code:

[cell.contentView setNeedsLayout];
[cell.contentView layoutIfNeeded];

It confounded me for awhile. Then I realized it's because those are only triggering layoutSubviews on the contentView, not the cell itself.

My working code looks like this:

TCAnswerDetailAppSummaryCell *cell = [self.tableView dequeueReusableCellWithIdentifier:@"TCAnswerDetailAppSummaryCell"];
[cell configureWithThirdPartyObject:self.app];
[cell layoutIfNeeded];
CGFloat height = [cell.contentView systemLayoutSizeFittingSize:UILayoutFittingCompressedSize].height;
return height;

Note that if you are creating a new cell, I'm pretty sure you don't need to call setNeedsLayout as it should already be set. In cases where you save a reference to a cell, you should probably call it. Either way it shouldn't hurt anything.

Another tip if you are using cell subclasses where you are setting things like preferredMaxLayoutWidth. As @smileyborg mentions, "your table view cell hasn't yet had its width fixed to the table view's width". This is true, and trouble if you are doing your work in your subclass and not in the view controller. However you can simply set the cell frame at this point using the table width:

For instance in the calculation for height:

self.summaryCell = [self.tableView dequeueReusableCellWithIdentifier:@"TCAnswerDetailDefaultSummaryCell"];
CGRect oldFrame = self.summaryCell.frame;
self.summaryCell.frame = CGRectMake(oldFrame.origin.x, oldFrame.origin.y, self.tableView.frame.size.width, oldFrame.size.height);

(I happen to cache this particular cell for re-use, but that's irrelevant).

FIX CSS <!--[if lt IE 8]> in IE

<!--[if lt IE 8]><![endif]-->

The lt in the above statement means less than, so 'if less than IE 8'.

For all versions of IE you can just use

<!--[if IE]><![endif]-->

or for all versions above ie 6 for example.

<!--[if gt IE 6]><![endif]-->

Where gt is 'greater than'

If you would like to write specific styles for versions below and including IE8 you can write

<!--[if lte IE 8]><![endif]-->

where lte is 'less than and equal' to

login failed for user 'sa'. The user is not associated with a trusted SQL Server connection. (Microsoft SQL Server, Error: 18452) in sql 2008

  1. Click on Start menu > Programs > Microsoft Sql Server > Configuration Tools

  2. Select Sql Server Surface Area Configuration.

  3. Now click on Surface Area configuration for services and connections

  4. On the left pane of pop up window click on Remote Connections and Select Local and Remote connections radio button.

  5. Select Using both TCP/IP and named pipes radio button.

  6. click on apply and ok.

Now when try to connect to sql server using sql username and password u'll get the error mentioned below

Cannot connect to SQLEXPRESS.

ADDITIONAL INFORMATION:

Login failed for user 'username'. The user is not associated with a trusted SQL Server connection. (Microsoft SQL Server, Error: 18452) ation To fix this error follow steps mentioned below

  1. connect to sql server using window authentication.

  2. Now right click on your server name at the top in left pane and select properties.

  3. Click on security and select sql server and windows authentication mode radio button.

  4. Click on OK.

  5. restart sql server servive by right clicking on server name and select restart.

Now your problem should be fixed and u'll be able to connect using sql server username and password.

Have fun. Ateev Gupta

Differences between time complexity and space complexity?

The way in which the amount of storage space required by an algorithm varies with the size of the problem it is solving. Space complexity is normally expressed as an order of magnitude, e.g. O(N^2) means that if the size of the problem (N) doubles then four times as much working storage will be needed.

Remove all special characters, punctuation and spaces from string

The most generic approach is using the 'categories' of the unicodedata table which classifies every single character. E.g. the following code filters only printable characters based on their category:

import unicodedata
# strip of crap characters (based on the Unicode database
# categorization:
# http://www.sql-und-xml.de/unicode-database/#kategorien

PRINTABLE = set(('Lu', 'Ll', 'Nd', 'Zs'))

def filter_non_printable(s):
    result = []
    ws_last = False
    for c in s:
        c = unicodedata.category(c) in PRINTABLE and c or u'#'
        result.append(c)
    return u''.join(result).replace(u'#', u' ')

Look at the given URL above for all related categories. You also can of course filter by the punctuation categories.

Understanding Python super() with __init__() methods

The main difference is that ChildA.__init__ will unconditionally call Base.__init__ whereas ChildB.__init__ will call __init__ in whatever class happens to be ChildB ancestor in self's line of ancestors (which may differ from what you expect).

If you add a ClassC that uses multiple inheritance:

class Mixin(Base):
  def __init__(self):
    print "Mixin stuff"
    super(Mixin, self).__init__()

class ChildC(ChildB, Mixin):  # Mixin is now between ChildB and Base
  pass

ChildC()
help(ChildC) # shows that the Method Resolution Order is ChildC->ChildB->Mixin->Base

then Base is no longer the parent of ChildB for ChildC instances. Now super(ChildB, self) will point to Mixin if self is a ChildC instance.

You have inserted Mixin in between ChildB and Base. And you can take advantage of it with super()

So if you are designed your classes so that they can be used in a Cooperative Multiple Inheritance scenario, you use super because you don't really know who is going to be the ancestor at runtime.

The super considered super post and pycon 2015 accompanying video explain this pretty well.

Typescript: No index signature with a parameter of type 'string' was found on type '{ "A": string; }

I resolved a similar issue in my getClass function like this:

import { ApiGateway } from './api-gateway.class';
import { AppSync } from './app-sync.class';
import { Cognito } from './cognito.class';

export type stackInstances = typeof ApiGateway | typeof  AppSync | typeof Cognito

export const classes = {
  ApiGateway,
  AppSync,
  Cognito
} as {
  [key: string]: stackInstances
};

export function getClass(name: string) {
  return classes[name];
}

Typing my classes const with my union type made typescript happy and it makes sense to me.

Set an environment variable in git bash

If you want to set environment variables permanently in Git-Bash, you have two options:

  1. Set a regular Windows environment variable. Git-bash gets all existing Windows environment variables at startupp.

  2. Set up env variables in .bash_profile file.

.bash_profile is by default located in a user home folder, like C:\users\userName\git-home\.bash_profile. You can change the path to the bash home folder by setting HOME Windows environment variable.

.bash_profile file uses the regular Bash syntax and commands

# Export a variable in .bash_profile
export DIR=c:\dir
# Nix path style works too
export DIR=/c/dir

# And don't forget to add quotes if a variable contains whitespaces
export ANOTHER_DIR="c:\some dir"

Read more information about Bash configurations files.

How can I execute Python scripts using Anaconda's version of Python?

The instructions in the official Python documentation worked for me: https://docs.python.org/2/using/windows.html#executing-scripts

  1. Launch a command prompt.

  2. Associate the correct file group with .py scripts:

    assoc .py=Python.File
    

Redirect all Python files to the new executable:

    ftype Python.File=C:\Path\to\pythonw.exe "%1" %*

The example shows how to associate the .py extension with the .pyw executable, but it works if you want to associate the .py extension with the Anaconda Python executable. You need administrative rights. The name "Python.File" could be anything, you just have to make sure is the same name in the ftype command. When you finish and before you try double-clicking the .py file, you must change the "Open with" in the file properties. The file type will be now ".py" and it is opened with the Anaconda python.exe.

Most efficient way to create a zero filled JavaScript array?

As of ECMAScript2016, there is one clear choice for large arrays.

Since this answer still shows up near the top on google searches, here's an answer for 2017.

Here's a current jsbench with a few dozen popular methods, including many proposed up to now on this question. If you find a better method please add, fork and share.

I want to note that there is no true most efficient way to create an arbitrary length zero filled array. You can optimize for speed, or for clarity and maintainability - either can be considered the more efficient choice depending on the needs of the project.

When optimizing for speed, you want to: create the array using literal syntax; set the length, initialize iterating variable, and iterate through the array using a while loop. Here's an example.

_x000D_
_x000D_
const arr = [];_x000D_
arr.length = 120000;_x000D_
let i = 0;_x000D_
while (i < 120000) {_x000D_
  arr[i] = 0;_x000D_
  i++;_x000D_
}
_x000D_
_x000D_
_x000D_

Another possible implementation would be:

(arr = []).length = n;
let i = 0;
while (i < n) {
    arr[i] = 0;
    i++;
}

But I strongly discourage using this second implantation in practice as it's less clear and doesn't allow you to maintain block scoping on your array variable.

These are significantly faster than filling with a for loop, and about 90% faster than the standard method of

const arr = Array(n).fill(0);

But this fill method is still the most efficient choice for smaller arrays due to it's clarity, conciseness and maintainability. The performance difference likely won't kill you unless you're making a lot of arrays with lengths on the order of thousands or more.

A few other important notes. Most style guides recommend you no longer use varwithout a very special reason when using ES6 or later. Use const for variables that won't be redefined and let for variables that will. The MDN and Airbnb's Style Guide are great places to go for more information on best practices. The questions wasn't about syntax, but it's important that people new to JS know about these new standards when searching through these reams of old and new answers.

Can Android do peer-to-peer ad-hoc networking?

I don't think it provides a multi-hop wireless packet routing environment. However you can try to integrate a simple routing mechanism. Just check out Wi-Share to get an idea how it can be done.

TypeScript enum to object array

There is a simple solution, So when you run Object.keys(Enum) that gonna give you a Array of Values and Keys, in first slice Values and in the second one keys, so why we don't just return the second slice, this code below works for me.

enum Enum {
   ONE,
   TWO,
   THREE,
   FOUR,
   FIVE,
   SIX,
   SEVEN
}
const keys = Object.keys(Enum); 
console.log(keys.slice(keys.length / 2));

String was not recognized as a valid DateTime " format dd/MM/yyyy"

You can use also

this.Text = "22112009";
DateTime newDateTime = new DateTime(Convert.ToInt32(this.Text.Substring(4, 4)), // Year
                                    Convert.ToInt32(this.Text.Substring(2,2)), // Month
                                    Convert.ToInt32(this.Text.Substring(0,2)));// Day

Invalid application path

I still haven’t find a solution, but find a workaround.

You can manually change IIS configuration, in system32\intsrv\config\applicationHost.config. Just manually create (copy-paste) section in <sites> and <location>.

Can't access Tomcat using IP address

If you are trying to access your web app which is running on apache tomcat server, it might be working perfect while you are trying to use it on http://localhost:8080/ , it will not work same if you are trying to access it on your mobile device browser for ex. chrome using http://192.168.x.x:8080/ so if you want to access via ip address on your remote/mobile device , do following settings

  1. Open server.xml file.
  2. Change

    <Connector connectionTimeout="20000" port="8080"protocol="HTTP/1.1" redirectPort="8443"/>
    

to.

    <Connector connectionTimeout="20000" port="8080" protocol="HTTP/1.1" redirectPort="8443" address="0.0.0.0" />
  1. Save the file
  2. Stop and restart the server
  3. Now access on your mobile device using ip address http://192.168.1.X:8080/

You are good to go.

Change the default editor for files opened in the terminal? (e.g. set it to TextEdit/Coda/Textmate)

If you want the editor to work with git operations, setting the $EDITOR environment variable may not be enough, at least not in the case of Sublime - e.g. if you want to rebase, it will just say that the rebase was successful, but you won't have a chance to edit the file in any way, git will just close it straight away:

git rebase -i HEAD~
Successfully rebased and updated refs/heads/master.

If you want Sublime to work correctly with git, you should configure it using:

git config --global core.editor "sublime -n -w"

I came here looking for this and found the solution in this gist on github.

How do I display todays date on SSRS report?

You can place a text-box to the report and add an expression with the following value in it:

="Report generation date:  " & Format(Globals!ExecutionTime,"dd/MM/yyyy  h:mm:ss tt" )

Grant SELECT on multiple tables oracle

No. As the documentation shows, you can only grant access to one object at a time.

Fastest way to compute entropy in Python

With the data as a pd.Series and scipy.stats, calculating the entropy of a given quantity is pretty straightforward:

import pandas as pd
import scipy.stats

def ent(data):
    """Calculates entropy of the passed `pd.Series`
    """
    p_data = data.value_counts()           # counts occurrence of each value
    entropy = scipy.stats.entropy(p_data)  # get entropy from counts
    return entropy

Note: scipy.stats will normalize the provided data, so this doesn't need to be done explicitly, i.e. passing an array of counts works fine.

android - How to get view from context?

first use this:

LayoutInflater inflater = (LayoutInflater) Read_file.this
                .getSystemService(Context.LAYOUT_INFLATER_SERVICE);

Read file is current activity in which you want your context.

View layout = inflater.inflate(R.layout.your_layout_name,(ViewGroup)findViewById(R.id.layout_name_id));

then you can use this to find any element in layout.

ImageView myImage = (ImageView) layout.findViewById(R.id.my_image);

How to gettext() of an element in Selenium Webdriver

text = driver.findElement(By.id('p_id')).getAttribute("innerHTML");

Find out where MySQL is installed on Mac OS X

It will be found in /usr/local/mysql if you use the mysql binaries or dmg to install it on your system instead of using MAMP

How to send POST request?

If you really want to handle with HTTP using Python, I highly recommend Requests: HTTP for Humans. The POST quickstart adapted to your question is:

>>> import requests
>>> r = requests.post("http://bugs.python.org", data={'number': 12524, 'type': 'issue', 'action': 'show'})
>>> print(r.status_code, r.reason)
200 OK
>>> print(r.text[:300] + '...')

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">
<head>
<title>
Issue 12524: change httplib docs POST example - Python tracker

</title>
<link rel="shortcut i...
>>> 

How to interactively (visually) resolve conflicts in SourceTree / git

I'm using SourceTree along with TortoiseMerge/Diff, which is very easy and convinient diff/merge tool.

If you'd like to use it as well, then:

  1. Get standalone version of TortoiseMerge/Diff (quite old, since it doesn't ship standalone since version 1.6.7 of TortosieSVN, that is since July 2011). Links and details in this answer.

  2. Unzip TortoiseIDiff.exe and TortoiseMerge.exe to any folder (c:\Program Files (x86)\Atlassian\SourceTree\extras\ in my case).

  3. In SourceTree open Tools > Options > Diff > External Diff / Merge. Select TortoiseMerge in both dropdown lists.

  4. Hit OK and point SourceTree to your location of TortoiseIDiff.exe and TortoiseMerge.exe.

After that, you can select Resolve Conflicts > Launch External Merge Tool from context menu on each conflicted file in your local repository. This will open up TortoiseMerge, where you can easily deal with all the conflicts, you have. Once finished, simply close TortoiseMerge (you don't even need to save changes, this will probably be done automatically) and after few seconds SourceTree should handle that gracefully.

The only problem is, that it automatically creates backup copy, even though proper option is unchecked.

How to prevent IFRAME from redirecting top-level window

In my case I want the user to visit the inner page so that server will see their ip as a visitor. If I use the php proxy technique I think that the inner page will see my server ip as a visitor so it is not good. The only solution I got so far is wilth onbeforeunload. Put this on your page:

<script type="text/javascript">
    window.onbeforeunload = function () {                       
         return "This will end your session";
    }
</script>

This works both in firefox and ie, thats what I tested for. you will find versions using something like evt.return(whatever) crap... that doesn't work in firefox.

change Oracle user account status from EXPIRE(GRACE) to OPEN

In case you know the password of that user, or you would like to guess it, do the following:

  • connect user/password

If this command connects successufully, you will see the message "connected", otherwise you'd see an error message. If you are then successufull logging, that means that you know the password. In that case, just do:

  • alter user NAME_OF_THE_USER identified by OLD_PASSWORD;

and this will reset the password to the same password as before and also reset the account_status for that user.

How can I sort an ArrayList of Strings in Java?

Check Collections#sort method. This automatically sorts your list according to natural ordering. You can apply this method on each sublist you obtain using List#subList method.

private List<String> teamsName = new ArrayList<String>();
List<String> subList = teamsName.subList(1, teamsName.size());
Collections.sort(subList);

Deserialize a JSON array in C#

This should work...

JavaScriptSerializer ser = new JavaScriptSerializer();
var records = new ser.Deserialize<List<Record>>(jsonData);

public class Person
{
    public string Name;
    public int Age;
    public string Location;
}
public class Record
{
    public Person record;
}

How to start MySQL with --skip-grant-tables?

Use the following command (notice the "d"): mysqld --skip-grant-tables

-bash: export: `=': not a valid identifier

I had the same problem and figured it out from your comments, but thought I would add the reason I caused the error to occur (for other beginners).

I had opened and edited .bash_profile using the open command in Terminal, which opened it in Text Editor. I typed in an addition to .bash_profile and it used improper quote characters. I opened .bash_profile in Atom and fixed up the error. I also associated the file with Atom for future editing.

Google Recaptcha v3 example demo

I thought a fully-functioning reCaptcha v3 example demo in PHP, using a Bootstrap 4 form, might be useful to some.

Reference the shown dependencies, swap in your email address and keys (create your own keys here), and the form is ready to test and use. I made code comments to better clarify the logic and also included commented-out console log and print_r lines to quickly enable viewing the validation token and data generated from Google.

The included jQuery function is optional, though it does create a much better user prompt experience in this demo.


PHP file (mail.php):

Add secret key (2 places) and email address where noted.

<?php

if ($_SERVER["REQUEST_METHOD"] == "POST") {

  # BEGIN Setting reCaptcha v3 validation data
  $url = "https://www.google.com/recaptcha/api/siteverify";
  $data = [
    'secret' => "your-secret-key-here",
    'response' => $_POST['token'],
    'remoteip' => $_SERVER['REMOTE_ADDR']
  ];

  $options = array(
    'http' => array(
      'header'  => "Content-type: application/x-www-form-urlencoded\r\n",
      'method'  => 'POST',
      'content' => http_build_query($data)
    )
    );
  
  # Creates and returns stream context with options supplied in options preset 
  $context  = stream_context_create($options);
  # file_get_contents() is the preferred way to read the contents of a file into a string
  $response = file_get_contents($url, false, $context);
  # Takes a JSON encoded string and converts it into a PHP variable
  $res = json_decode($response, true);
  # END setting reCaptcha v3 validation data
   
    // print_r($response); 
# Post form OR output alert and bypass post if false. NOTE: score conditional is optional
# since the successful score default is set at >= 0.5 by Google. Some developers want to
# be able to control score result conditions, so I included that in this example.

  if ($res['success'] == true && $res['score'] >= 0.5) {
 
    # Recipient email
    $mail_to = "[email protected]";
    
    # Sender form data
    $subject = trim($_POST["subject"]);
    $name = str_replace(array("\r","\n"),array(" "," ") , strip_tags(trim($_POST["name"])));
    $email = filter_var(trim($_POST["email"]), FILTER_SANITIZE_EMAIL);
    $phone = trim($_POST["phone"]);
    $message = trim($_POST["message"]);
    
    if (empty($name) OR !filter_var($email, FILTER_VALIDATE_EMAIL) OR empty($phone) OR empty($subject) OR empty($message)) {
      # Set a 400 (bad request) response code and exit
      http_response_code(400);
      echo '<p class="alert-warning">Please complete the form and try again.</p>';
      exit;
    }

    # Mail content
    $content = "Name: $name\n";
    $content .= "Email: $email\n\n";
    $content .= "Phone: $phone\n";
    $content .= "Message:\n$message\n";

    # Email headers
    $headers = "From: $name <$email>";

    # Send the email
    $success = mail($mail_to, $subject, $content, $headers);
    
    if ($success) {
      # Set a 200 (okay) response code
      http_response_code(200);
      echo '<p class="alert alert-success">Thank You! Your message has been successfully sent.</p>';
    } else {
      # Set a 500 (internal server error) response code
      http_response_code(500);
      echo '<p class="alert alert-warning">Something went wrong, your message could not be sent.</p>';
    }   

  } else {

    echo '<div class="alert alert-danger">
        Error! The security token has expired or you are a bot.
       </div>';
  }  

} else {
  # Not a POST request, set a 403 (forbidden) response code
  http_response_code(403);
  echo '<p class="alert-warning">There was a problem with your submission, please try again.</p>';
} ?>

HTML <head>

Bootstrap CSS dependency and reCaptcha client-side validation Place between <head> tags - paste your own site-key where noted.

<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0/css/bootstrap.min.css">
<script src="https://www.google.com/recaptcha/api.js?render=your-site-key-here"></script>

HTML <body>

Place between <body> tags.

<!-- contact form demo container -->
<section style="margin: 50px 20px;">
  <div style="max-width: 768px; margin: auto;">
    
    <!-- contact form -->
    <div class="card">
      <h2 class="card-header">Contact Form</h2>
      <div class="card-body">
        <form class="contact_form" method="post" action="mail.php">

          <!-- form fields -->
          <div class="row">
            <div class="col-md-6 form-group">
              <input name="name" type="text" class="form-control" placeholder="Name" required>
            </div>
            <div class="col-md-6 form-group">
              <input name="email" type="email" class="form-control" placeholder="Email" required>
            </div>
            <div class="col-md-6 form-group">
              <input name="phone" type="text" class="form-control" placeholder="Phone" required>
            </div>
            <div class="col-md-6 form-group">
              <input name="subject" type="text" class="form-control" placeholder="Subject" required>
            </div>
            <div class="col-12 form-group">
              <textarea name="message" class="form-control" rows="5" placeholder="Message" required></textarea>
            </div>

            <!-- form message prompt -->
            <div class="row">
              <div class="col-12">
                <div class="contact_msg" style="display: none">
                  <p>Your message was sent.</p>
                </div>
              </div>
            </div>

            <div class="col-12">
              <input type="submit" value="Submit Form" class="btn btn-success" name="post">
            </div>

            <!-- hidden reCaptcha token input -->
            <input type="hidden" id="token" name="token">
          </div>

        </form>
      </div>
    </div>

  </div>
</section>
<script>
  grecaptcha.ready(function() {
    grecaptcha.execute('your-site-key-here', {action: 'homepage'}).then(function(token) {
       // console.log(token);
       document.getElementById("token").value = token;
    });
    // refresh token every minute to prevent expiration
    setInterval(function(){
      grecaptcha.execute('your-site-key-here', {action: 'homepage'}).then(function(token) {
        console.log( 'refreshed token:', token );
        document.getElementById("token").value = token;
      });
    }, 60000);

  });
</script>

<!-- References for the optional jQuery function to enhance end-user prompts -->
<script src="https://code.jquery.com/jquery-3.3.1.min.js"></script>
<script src="form.js"></script>

Optional jQuery function for enhanced UX (form.js):

(function ($) {
'use strict';

var form = $('.contact_form'),
  message = $('.contact_msg'),
  form_data;

// Success function
function done_func(response) {
  message.fadeIn()
  message.html(response);
  setTimeout(function () {
    message.fadeOut();
  }, 10000);
  form.find('input:not([type="submit"]), textarea').val('');
}

// fail function
function fail_func(data) {
  message.fadeIn()
  message.html(data.responseText);
  setTimeout(function () {
    message.fadeOut();
  }, 10000);
}

form.submit(function (e) {
  e.preventDefault();
  form_data = $(this).serialize();
  $.ajax({
    type: 'POST',
    url: form.attr('action'),
    data: form_data
  })
  .done(done_func)
  .fail(fail_func);
}); })(jQuery);

Ship an application with a database

Shipping the database inside the apk and then copying it to /data/data/... will double the size of the database (1 in apk, 1 in data/data/...), and will increase the apk size (of course). So your database should not be too big.

twitter bootstrap navbar fixed top overlapping site

I put this before the yield container:

<div id="fix-for-navbar-fixed-top-spacing" style="height: 42px;">&nbsp;</div>

I like this approach because it documents the hack needed to get it work, plus it also works for the mobile nav.

EDIT - this works much better:

@media (min-width: 980px) {
  body {
    padding-top: 60px;
    padding-bottom: 42px;
  }
}

Alter and Assign Object Without Side Effects

This is a textbook case for a constructor function:

var myArray = [];

function myElement(id, value){
    this.id = id
    this.value = value
}

myArray[0] = new myElement(0,1)
myArray[1] = new myElement(2,3)
// or myArray.push(new myElement(1, 1))

Configuration with name 'default' not found. Android Studio

I had this issue with Jenkins. The cause: I had renamed a module module to Module. I found out that git had gotten confused somehow and kept both module and Module directories, with the contents spread between both folders. The build.gradle was kept in module but the module's name was Module so it was unable to find the default configuration.

I fixed it by backing up the contents of Module, manually deleting module folder from the repo and restoring + pushing the lost files.

How to find longest string in the table column data

To answer your question, and get the Prefix too, for MySQL you can do:

select Prefix, CR, length(CR) from table1 order by length(CR) DESC limit 1;

and it will return


+-------+----------------------------+--------------------+
| Prefix| CR                         |         length(CR) |
+-------+----------------------------+--------------------+
| g     | ;#WR_1;#WR_2;#WR_3;#WR_4;# |                 26 |
+-------+----------------------------+--------------------+
1 row in set (0.01 sec)

Disable-web-security in Chrome 48+

Install This Chrome-plugin for Disable-web-security in Chrome::

" Allow-Control-Allow-Origin: * " link Here or you can google above plugin if you want.

it is very easy to enable and disable the security with this plugin.

how to hide <li> bullets in navigation menu and footer links BUT show them for listing items

You can style li elements differently based on their class, their id or their ancestor elements:

li { /* styles all li elements*/
    list-style-type: none;
}

#ParentListID li { /* styles the li elements that have an ancestor element
                      of id="ParentListID" */
    list-style-type: bullet;
}

li.className { /* styles li elements of class="className" */
    list-style-type: bullet;
}

Or, to use the ancestor elements:

#navigationContainerID li { /* specifically styles the li elements with an ancestor of
                               id="navigationContainerID" */
    list-style-type: none;
}

li { /* then styles all other li elements that don't have that ancestor element */
    list-style-type: bullet;
}

Socket.IO - how do I get a list of connected sockets/clients?

In Socket.IO 0.7 you have a clients method on the namespaces, this returns a array of all connected sockets.

API for no namespace:

var clients = io.sockets.clients();
var clients = io.sockets.clients('room'); // all users from room `room`

For a namespace

var clients = io.of('/chat').clients();
var clients = io.of('/chat').clients('room'); // all users from room `room`

Hopes this helps someone in the future

NOTE: This Solution ONLY works with version prior to 1.0


UPDATED 2020 Mar 06

From 1.x and above, please refer to this link: getting how many people are in a chat room in socket.io

Android Studio Gradle: Error:Execution failed for task ':app:processDebugGoogleServices'. > No matching client found for package

check that, in your "google-services.json" file your package_name is available or not

How to set the holo dark theme in a Android app?

By default android will set Holo to the Dark theme. There is no theme called Holo.Dark, there's only Holo.Light, that's why you are getting the resource not found error.

So just set it to:

<style name="AppTheme" parent="android:Theme.Holo" />

T-SQL Subquery Max(Date) and Joins

All other answers must work, but using your same syntax (and understanding why the error)

SELECT * FROM MyParts LEFT JOIN MyPrice ON MyParts.Partid = MyPrice.Partid WHERE 
MyPart.PriceDate = (SELECT MAX(MyPrice2.PriceDate) FROM MyPrice as MyPrice2 
WHERE MyPrice2.Partid =  MyParts.Partid)

Interactive shell using Docker Compose

You need to include the following lines in your docker-compose.yml:

version: "3"
services:
  app:
    image: app:1.2.3
    stdin_open: true # docker run -i
    tty: true        # docker run -t

The first corresponds to -i in docker run and the second to -t.

How do I execute a stored procedure once for each row returned by query?

Use a table variable or a temporary table.

As has been mentioned before, a cursor is a last resort. Mostly because it uses lots of resources, issues locks and might be a sign you're just not understanding how to use SQL properly.

Side note: I once came across a solution that used cursors to update rows in a table. After some scrutiny, it turned out the whole thing could be replaced with a single UPDATE command. However, in this case, where a stored procedure should be executed, a single SQL-command won't work.

Create a table variable like this (if you're working with lots of data or are short on memory, use a temporary table instead):

DECLARE @menus AS TABLE (
    id INT IDENTITY(1,1),
    parent NVARCHAR(128),
    child NVARCHAR(128));

The id is important.

Replace parent and child with some good data, e.g. relevant identifiers or the whole set of data to be operated on.

Insert data in the table, e.g.:

INSERT INTO @menus (parent, child) 
  VALUES ('Some name',  'Child name');
...
INSERT INTO @menus (parent,child) 
  VALUES ('Some other name', 'Some other child name');

Declare some variables:

DECLARE @id INT = 1;
DECLARE @parentName NVARCHAR(128);
DECLARE @childName NVARCHAR(128);

And finally, create a while loop over the data in the table:

WHILE @id IS NOT NULL
BEGIN
    SELECT @parentName = parent,
           @childName = child 
        FROM @menus WHERE id = @id;

    EXEC myProcedure @parent=@parentName, @child=@childName;

    SELECT @id = MIN(id) FROM @menus WHERE id > @id;
END

The first select fetches data from the temporary table. The second select updates the @id. MIN returns null if no rows were selected.

An alternative approach is to loop while the table has rows, SELECT TOP 1 and remove the selected row from the temp table:

WHILE EXISTS(SELECT 1 FROM @menuIDs) 
BEGIN
    SELECT TOP 1 @menuID = menuID FROM @menuIDs;

    EXEC myProcedure @menuID=@menuID;

    DELETE FROM @menuIDs WHERE menuID = @menuID;
END;

Collections.emptyList() vs. new instance

Collections.emptyList is immutable so there is a difference between the two versions so you have to consider users of the returned value.

Returning new ArrayList<Foo> always creates a new instance of the object so it has a very slight extra cost associated with it which may give you a reason to use Collections.emptyList. I like using emptyList just because it's more readable.

Entity Framework: table without primary key

This is just an addition to @Erick T's answer. If there is no single column with unique values, the workaround is to use a composite key, as follows:

[Key]
[Column("LAST_NAME", Order = 1)]
public string LastName { get; set; }

[Key]
[Column("FIRST_NAME", Order = 2)]
public string FirstName { get; set; }

Again, this is just a workaround. The real solution is to fix the data model.

JavaScript calculate the day of the year (1 - 366)

I would like to provide a solution that does calculations adding the days for each previous month:

_x000D_
_x000D_
function getDayOfYear(date) {_x000D_
    var month = date.getMonth();_x000D_
    var year = date.getFullYear();_x000D_
    var days = date.getDate();_x000D_
    for (var i = 0; i < month; i++) {_x000D_
        days += new Date(year, i+1, 0).getDate();_x000D_
    }_x000D_
    return days;_x000D_
}_x000D_
var input = new Date(2017, 7, 5);_x000D_
console.log(input);_x000D_
console.log(getDayOfYear(input));
_x000D_
_x000D_
_x000D_

This way you don't have to manage the details of leap years and daylight saving.

Non-static method requires a target

Normally it happens when the target is null. So better check the invoke target first then do the linq query.

How can I write data in YAML format in a file?

import yaml

data = dict(
    A = 'a',
    B = dict(
        C = 'c',
        D = 'd',
        E = 'e',
    )
)

with open('data.yml', 'w') as outfile:
    yaml.dump(data, outfile, default_flow_style=False)

The default_flow_style=False parameter is necessary to produce the format you want (flow style), otherwise for nested collections it produces block style:

A: a
B: {C: c, D: d, E: e}

Get a filtered list of files in a directory

import os

dir="/path/to/dir"
[x[0]+"/"+f for x in os.walk(dir) for f in x[2] if f.endswith(".jpg")]

This will give you a list of jpg files with their full path. You can replace x[0]+"/"+f with f for just filenames. You can also replace f.endswith(".jpg") with whatever string condition you wish.

Sourcetree - undo unpushed commits

If you select the log entry to which you want to revert to then you can click on "Reset to this commit". Only use this option if you didn't push the reverse commit changes. If you're worried about losing the changes then you can use the soft mode which will leave a set of uncommitted changes (what you just changed). Using the mixed resets the working copy but keeps those changes, and a hard will just get rid of the changes entirely. Here's some screenshots:

enter image description here

What is Bit Masking?

A mask defines which bits you want to keep, and which bits you want to clear.

Masking is the act of applying a mask to a value. This is accomplished by doing:

  • Bitwise ANDing in order to extract a subset of the bits in the value
  • Bitwise ORing in order to set a subset of the bits in the value
  • Bitwise XORing in order to toggle a subset of the bits in the value

Below is an example of extracting a subset of the bits in the value:

Mask:   00001111b
Value:  01010101b

Applying the mask to the value means that we want to clear the first (higher) 4 bits, and keep the last (lower) 4 bits. Thus we have extracted the lower 4 bits. The result is:

Mask:   00001111b
Value:  01010101b
Result: 00000101b

Masking is implemented using AND, so in C we get:

uint8_t stuff(...) {
  uint8_t mask = 0x0f;   // 00001111b
  uint8_t value = 0x55;  // 01010101b
  return mask & value;
}

Here is a fairly common use-case: Extracting individual bytes from a larger word. We define the high-order bits in the word as the first byte. We use two operators for this, &, and >> (shift right). This is how we can extract the four bytes from a 32-bit integer:

void more_stuff(uint32_t value) {             // Example value: 0x01020304
    uint32_t byte1 = (value >> 24);           // 0x01020304 >> 24 is 0x01 so
                                              // no masking is necessary
    uint32_t byte2 = (value >> 16) & 0xff;    // 0x01020304 >> 16 is 0x0102 so
                                              // we must mask to get 0x02
    uint32_t byte3 = (value >> 8)  & 0xff;    // 0x01020304 >> 8 is 0x010203 so
                                              // we must mask to get 0x03
    uint32_t byte4 = value & 0xff;            // here we only mask, no shifting
                                              // is necessary
    ...
}

Notice that you could switch the order of the operators above, you could first do the mask, then the shift. The results are the same, but now you would have to use a different mask:

uint32_t byte3 = (value & 0xff00) >> 8;

SQL Server IIF vs CASE

IIF is the same as CASE WHEN <Condition> THEN <true part> ELSE <false part> END. The query plan will be the same. It is, perhaps, "syntactical sugar" as initially implemented.

CASE is portable across all SQL platforms whereas IIF is SQL SERVER 2012+ specific.

How can I obfuscate (protect) JavaScript?

The problem with interpreted languages, is that you send the source to get them working (unless you have a compiler to bytecode, but then again, it is quite trivial to decompile).

So, if you don't want to sacrifice performance, you can only act on variable and function names, eg. replacing them with a, b... aa, ab... or a101, a102, etc. And, of course, remove as much space/newlines as you can (that's what so called JS compressors do).
Obfuscating strings will have a performance hit, if you have to encrypt them and decrypt them in real time. Plus a JS debugger can show the final values...

how to dynamically add options to an existing select in vanilla javascript

The simplest way is:

selectElement.add(new Option('Text', 'value'));

Yes, that simple. And it works even in IE8. And has other optional parameters.

See docs:

JavaScript "cannot read property "bar" of undefined

You can safeguard yourself either of these two ways:

function myFunc(thing) {
    if (thing && thing.foo && thing.foo.bar) {
        // safe to use thing.foo.bar here
    }
}

function myFunc(thing) {
    try {
        var x = thing.foo.bar;
        // do something with x
    } catch(e) {
        // do whatever you want when thing.foo.bar didn't work
    }
}

In the first example, you explicitly check all the possible elements of the variable you're referencing to make sure it's safe before using it so you don't get any unplanned reference exceptions.

In the second example, you just put an exception handler around it. You just access thing.foo.bar assuming it exists. If it does exist, then the code runs normally. If it doesn't exist, then it will throw an exception which you will catch and ignore. The end result is the same. If thing.foo.bar exists, your code using it executes. If it doesn't exist that code does not execute. In all cases, the function runs normally.

The if statement is faster to execute. The exception can be simpler to code and use in complex cases where there may be many possible things to protect against and your code is structured so that throwing an exception and handling it is a clean way to skip execution when some piece of data does not exist. Exceptions are a bit slower when the exception is thrown.

JavaScript associative array to JSON

I posted a fix for this here

You can use this function to modify JSON.stringify to encode arrays, just post it near the beginning of your script (check the link above for more detail):

// Upgrade for JSON.stringify, updated to allow arrays
(function(){
    // Convert array to object
    var convArrToObj = function(array){
        var thisEleObj = new Object();
        if(typeof array == "object"){
            for(var i in array){
                var thisEle = convArrToObj(array[i]);
                thisEleObj[i] = thisEle;
            }
        }else {
            thisEleObj = array;
        }
        return thisEleObj;
    };
    var oldJSONStringify = JSON.stringify;
    JSON.stringify = function(input){
        if(oldJSONStringify(input) == '[]')
            return oldJSONStringify(convArrToObj(input));
        else
            return oldJSONStringify(input);
    };
})();

Converting a Pandas GroupBy output from Series to DataFrame

Below solution may be simpler:

df1.reset_index().groupby( [ "Name", "City"],as_index=False ).count()

Unzip files programmatically in .net

We have used SharpZipLib successfully on many projects. I know it's a third party tool, but source code is included and could provide some insight if you chose to reinvent the wheel here.

Compile a DLL in C/C++, then call it from another program

There is but one difference. You have to take care or name mangling win C++. But on windows you have to take care about 1) decrating the functions to be exported from the DLL 2) write a so called .def file which lists all the exported symbols.

In Windows while compiling a DLL have have to use

__declspec(dllexport)

but while using it you have to write __declspec(dllimport)

So the usual way of doing that is something like

#ifdef BUILD_DLL
#define EXPORT __declspec(dllexport)
#else
#define EXPORT __declspec(dllimport)
#endif

The naming is a bit confusing, because it is often named EXPORT.. But that's what you'll find in most of the headers somwhere. So in your case you'd write (with the above #define)

int DLL_EXPORT add.... int DLL_EXPORT mult...

Remember that you have to add the Preprocessor directive BUILD_DLL during building the shared library.

Regards Friedrich

Create a unique number with javascript time

Using toString(36), slightly slow, here is the faster and unique solution:

new Date().getUTCMilliseconds().toString() +
"-" +
Date.now() +
"-" +
filename.replace(/\s+/g, "-").toLowerCase()

How to Test Facebook Connect Locally

I suggest creating a test app (for dev environment only) on https://developers.facebook.com/apps and set: Website with Facebook Login property to your localhost:[port] settings.
this option will work fine with no need to change hosts.
remember to change the appId back to your production app once you go live.

Edit - in the latest fb version you'll find it under the settings tab. enter image description here

How to get javax.comm API?

you can find Java Communications API 2.0 in below link

http://www.java2s.com/Code/Jar/c/Downloadcomm20jar.htm

How to force reloading a page when using browser back button?

Currently this is the most up to date way reload page if the user clicks the back button.

const [entry] = performance.getEntriesByType("navigation");

// Show it in a nice table in the developer console
console.table(entry.toJSON());

if (entry["type"] === "back_forward")
    location.reload();

See here for source

How to visualize an XML schema?

That picture is generated from a XML Schema editing tool, such as Altova's XMLSpy.

There are a number of XML tools around, all of which will include a Graphical XSD Viewer. I mentioned XML Spy simply because it is the brand leader. Also many general IDEs like Eclipse, Visual Studio and Oracle JDeveloper will be able to do this trick.

How do I automatically set the $DISPLAY variable for my current session?

do you use Bash? Go to the file .bashrc in your home directory and set the variable, then export it.

DISPLAY=localhost:0.0 ; export DISPLAY

you can use /etc/bashrc if you want to do it for all the users.

You may also want to look in ~/.bash_profile and /etc/profile

EDIT:

function get_xserver ()
{
    case $TERM in
       xterm )
            XSERVER=$(who am i | awk '{print $NF}' | tr -d ')''(' )    
            XSERVER=${XSERVER%%:*}
            ;;
        aterm | rxvt)           
            ;;
    esac  
}

if [ -z ${DISPLAY:=""} ]; then
    get_xserver
    if [[ -z ${XSERVER}  || ${XSERVER} == $(hostname) || \
      ${XSERVER} == "unix" ]]; then 
        DISPLAY=":0.0"          # Display on local host.
    else
        DISPLAY=${XSERVER}:0.0  # Display on remote host.
    fi
fi

export DISPLAY

SQL to search objects, including stored procedures, in Oracle

ALL_SOURCE describes the text source of the stored objects accessible to the current user.

Here is one of the solution

select * from ALL_SOURCE where text like '%some string%';

How to bring back "Browser mode" in IE11?

Easiest way, especially if in MSDN,,wasted hours of my time, stupid MS

http://support.microsoft.com/kb/2900662/en-us?sd=rss

  1. Open the Developer Tools pane. To do this, press F12.
  2. Open the Emulation screen. To do this, press Ctrl+8.
  3. On the Document mode list under Mode, click 9.
  4. On the User agent string list under Mode, click Internet Explorer 9.

Using Javascript can you get the value from a session attribute set by servlet in the HTML page

<%
String session_val = (String)session.getAttribute("sessionval"); 
System.out.println("session_val"+session_val);
%>
<html>
<head>
<script type="text/javascript">
var session_obj= '<%=session_val%>';
alert("session_obj"+session_obj);
</script>
</head>
</html>

Open an image using URI in Android's default gallery image viewer

Try use it:

Uri uri =  Uri.fromFile(entry);
Intent intent = new Intent(android.content.Intent.ACTION_VIEW);
String mime = "*/*";
MimeTypeMap mimeTypeMap = MimeTypeMap.getSingleton();
if (mimeTypeMap.hasExtension(
    mimeTypeMap.getFileExtensionFromUrl(uri.toString())))
    mime = mimeTypeMap.getMimeTypeFromExtension(
        mimeTypeMap.getFileExtensionFromUrl(uri.toString()));
intent.setDataAndType(uri,mime);
startActivity(intent);

axios post request to send form data

Upload (multiple) binary files

Node.js

Things become complicated when you want to post files via multipart/form-data, especially multiple binary files. Below is a working example:

const FormData = require('form-data')
const fs = require('fs')
const path = require('path')

const formData = new FormData()
formData.append('files[]', JSON.stringify({ to: [{ phoneNumber: process.env.RINGCENTRAL_RECEIVER }] }), 'test.json')
formData.append('files[]', fs.createReadStream(path.join(__dirname, 'test.png')), 'test.png')
await rc.post('/restapi/v1.0/account/~/extension/~/fax', formData, {
  headers: formData.getHeaders()
})
  • Instead of headers: {'Content-Type': 'multipart/form-data' } I prefer headers: formData.getHeaders()
  • I use async and await above, you can change them to plain Promise statements if you don't like them
  • In order to add your own headers, you just headers: { ...yourHeaders, ...formData.getHeaders() }

Newly added content below:

Browser

Browser's FormData is different from the NPM package 'form-data'. The following code works for me in browser:

HTML:

<input type="file" id="image" accept="image/png"/>

JavaScript:

const formData = new FormData()

// add a non-binary file
formData.append('files[]', new Blob(['{"hello": "world"}'], { type: 'application/json' }), 'request.json')

// add a binary file
const element = document.getElementById('image')
const file = element.files[0]
formData.append('files[]', file, file.name)
await rc.post('/restapi/v1.0/account/~/extension/~/fax', formData)

How to insert data into SQL Server

I think you lack to pass Connection object to your command object. and it is much better if you will use command and parameters for that.

using (SqlConnection connection = new SqlConnection("ConnectionStringHere"))
{
    using (SqlCommand command = new SqlCommand())
    {
        command.Connection = connection;            // <== lacking
        command.CommandType = CommandType.Text;
        command.CommandText = "INSERT into tbl_staff (staffName, userID, idDepartment) VALUES (@staffName, @userID, @idDepart)";
        command.Parameters.AddWithValue("@staffName", name);
        command.Parameters.AddWithValue("@userID", userId);
        command.Parameters.AddWithValue("@idDepart", idDepart);

        try
        {
            connection.Open();
            int recordsAffected = command.ExecuteNonQuery();
        }
        catch(SqlException)
        {
            // error here
        }
        finally
        {
            connection.Close();
        }
    }
}

How do I use PHP to get the current year?

To get the current year using PHP’s date function, you can pass in the “Y” format character like so:

//Getting the current year using //PHP's date function.

$year = date("Y");
echo $year;

//Getting the current year using //PHP's date function.

$year = date("Y");
echo $year;

The example above will print out the full 4-digit representation of the current year.

If you only want to retrieve the 2-digit format, then you can use the lowercase “y” format character:

$year = date("y"); echo $year; 1 2 $year = date("y"); echo $year; The snippet above will print out 20 instead of 2020, or 19 instead of 2019, etc.

Declaring variables inside or outside of a loop

Truly, the question stated above is an programming issue. How would you like to program your code? Where do you need the 'STR' to be accessed? There is no use of declaring a variable which is used locally as a global variable. Basics of programming I believe.

Zero-pad digits in string

There's also str_pad

<?php
$input = "Alien";
echo str_pad($input, 10);                      // produces "Alien     "
echo str_pad($input, 10, "-=", STR_PAD_LEFT);  // produces "-=-=-Alien"
echo str_pad($input, 10, "_", STR_PAD_BOTH);   // produces "__Alien___"
echo str_pad($input, 6 , "___");               // produces "Alien_"
?>

Trying to make bootstrap modal wider

Always have handy the un-minified CSS for bootstrap so you can see what styles they have on their components, then create a CSS file AFTER it, if you don't use LESS and over-write their mixins or whatever

This is the default modal css for 768px and up:

@media (min-width: 768px) {
  .modal-dialog {
    width: 600px;
    margin: 30px auto;
  }
  ...
}

They have a class modal-lg for larger widths

@media (min-width: 992px) {
  .modal-lg {
    width: 900px;
  }
}

If you need something twice the 600px size, and something fluid, do something like this in your CSS after the Bootstrap css and assign that class to the modal-dialog.

@media (min-width: 768px) {
  .modal-xl {
    width: 90%;
   max-width:1200px;
  }
}

HTML

<div class="modal-dialog modal-xl">

Demo: http://jsbin.com/yefas/1

How can I print literal curly-brace characters in a string and also use .format on it?

Although not any better, just for the reference, you can also do this:

>>> x = '{}Hello{} {}'
>>> print x.format('{','}',42)
{Hello} 42

It can be useful for example when someone wants to print {argument}. It is maybe more readable than '{{{}}}'.format('argument')

Note that you omit argument positions (e.g. {} instead of {0}) after Python 2.7

Capture Video of Android's Screen

If you want to record the user navigation so you can test UI and other things, I recommend you to use TestFairy

It allows you to send the apk to some test users by email and see a video with all the sessions in the app and even the app crashes and device stats.

MySQL Join Where Not Exists

I'd probably use a LEFT JOIN, which will return rows even if there's no match, and then you can select only the rows with no match by checking for NULLs.

So, something like:

SELECT V.*
FROM voter V LEFT JOIN elimination E ON V.id = E.voter_id
WHERE E.voter_id IS NULL

Whether that's more or less efficient than using a subquery depends on optimization, indexes, whether its possible to have more than one elimination per voter, etc.

error: function returns address of local variable

a is defined locally in the function, and can't be used outside the function. If you want to return a char array from the function, you'll need to allocate it dynamically:

char *a = malloc(1000);

And at some point call free on the returned pointer.

You should also see a warning at this line: char b = "blah";: you're trying to assign a string literal to a char.

How to uninstall Golang?

On linux we can do like this to remove go completely:

rm -rf "/usr/local/.go/"
rm -rf "/usr/local/go/"

These two command remove go and hidden .go files. Now we also have to update entries in shell profile.

Open your basic file. Mostly I open like this sudo gedit ~/.bashrc and remove all go mentions.

You can also do by sed command in ubuntu

sed -i '/# GoLang/d' .bashrc
sed -i '/export GOROOT/d' .bashrc
sed -i '/:$GOROOT/d' .bashrc
sed -i '/export GOPATH/d' .bashrc
sed -i '/:$GOPATH/d' .bashrc

It will remove Golang from everywhere. Also run this after running these command

source ~/.bash_profile

Tested on linux 18.04 also. That's All.

Resolve Git merge conflicts in favor of their changes during a pull

git pull -s recursive -X theirs <remoterepo or other repo>

Or, simply, for the default repository:

git pull -X theirs

If you're already in conflicted state...

git checkout --theirs path/to/file

How do you properly determine the current script directory?

Hopefully this helps:- If you run a script/module from anywhere you'll be able to access the __file__ variable which is a module variable representing the location of the script.

On the other hand, if you're using the interpreter you don't have access to that variable, where you'll get a name NameError and os.getcwd() will give you the incorrect directory if you're running the file from somewhere else.

This solution should give you what you're looking for in all cases:

from inspect import getsourcefile
from os.path import abspath
abspath(getsourcefile(lambda:0))

I haven't thoroughly tested it but it solved my problem.

How to check if a radiobutton is checked in a radiogroup in Android?

If you want to check on just one RadioButton you can use the isChecked function

if(radioButton.isChecked())
{
  // is checked    
}
else
{
  // not checked
}

and if you have a RadioGroup you can use

if (radioGroup.getCheckedRadioButtonId() == -1)
{
  // no radio buttons are checked
}
else
{
  // one of the radio buttons is checked
}

What is the difference between Google App Engine and Google Compute Engine?

As explained already Google Compute Engine (GCE) is the Infrastructure as a service (IaaS) while Google App Engine (GAE) is Platform as a Service (PaaS). You can check the following diagram to understand the difference in a better way (Taken from and better explained here) -

Cloud Computing Types

Google Compute Engine
GCE is an important service provided from Google Cloud Platform (GCP) since most of the GCP services use GCE instances (VMs) beneath the management layer (not sure which one don't). This includes App Engine, Cloud Functions, Kubernetes Engine (Earlier Container Engine), Cloud SQL, etc. GCE instances are the most customisable unit there and thus should only be used when your application can't run on any other GCP services. Most of the time people use GCE to transfer their On-Prem applications to GCP, since it requires minimal changes. Later, they can choose to use other GCP services for separate component of their apps.

Google App Engine
GAE is the first service offered by GCP (Long before Google came to the cloud business). It autoscales from 0 to unlimited instances (It uses GCE underneath). It comes with 2 flavors Standard Environment and Flexible Environment.

Standard Environment is really fast, scales down to 0 instance when no-one is using your app, scales up and down in seconds and have dedicated Google services and libraries for caching, authentication etc. The caveat with Standard environment is that it is very restrictive since it runs in a sandbox. You have to use managed runtimes for specific programming languages only. The recent additions are Node.js (8.x) and Python 3.x. The older runtimes are available for Go, PHP, Python 2.7, Java etc.

Flexible Environment is more open as it allows you to use custom runtimes as it uses docker containers. Thus if your runtime is not available in the provided runtimes, you can always create your own dockerfile for the execution environment. The caveat with it is, it requires having at least 1 instance running, even if no-one is using your app, plus the scaling up and down requires few minutes.

Don't confuse GAE flexible with Kubernetes Engine, as the later one uses actual Kubernetes and provides much more customisation and features. GAE Flex is useful when you want stateless containers and your application rely on HTTP or HTTPS protocols only. For other protocols Kubernetes Engine (GKE) or GCE is your only choice. Check my other answer for better explanation.

How to set thousands separator in Java?

The accepted answer has to be really altered otherwise not working. The getDecimalFormatSymbols makes a defensive copy. Thus,

DecimalFormat formatter = (DecimalFormat) NumberFormat.getInstance(Locale.US);
DecimalFormatSymbols symbols = formatter.getDecimalFormatSymbols();

symbols.setGroupingSeparator(' ');
formatter.setDecimalFormatSymbols(symbols);
System.out.println(formatter.format(bd.longValue()));

The new line is this one: formatter.setDecimalFormatSymbols(symbols);

Simulate delayed and dropped packets on Linux

iptables(8) has a statistic match module that can be used to match every nth packet. To drop this packet, just append -j DROP.

SQL query for extracting year from a date

SELECT date_column_name FROM table_name WHERE EXTRACT(YEAR FROM date_column_name) = 2020

Android dex gives a BufferOverflowException when building

I had the same problem, though my project did not use the support library. Adding libs/android-support-v4.jar to the project worked around the problem without needing to revert the build tools back from v19.

How do I open workbook programmatically as read-only?

Does this work?

Workbooks.Open Filename:=filepath, ReadOnly:=True

Or, as pointed out in a comment, to keep a reference to the opened workbook:

Dim book As Workbook
Set book = Workbooks.Open(Filename:=filepath, ReadOnly:=True)

Absolute position of an element on the screen using jQuery

See .offset() here in the jQuery doc. It gives the position relative to the document, not to the parent. You perhaps have .offset() and .position() confused. If you want the position in the window instead of the position in the document, you can subtract off the .scrollTop() and .scrollLeft() values to account for the scrolled position.

Here's an excerpt from the doc:

The .offset() method allows us to retrieve the current position of an element relative to the document. Contrast this with .position(), which retrieves the current position relative to the offset parent. When positioning a new element on top of an existing one for global manipulation (in particular, for implementing drag-and-drop), .offset() is the more useful.

To combine these:

var offset = $("selector").offset();
var posY = offset.top - $(window).scrollTop();
var posX = offset.left - $(window).scrollLeft(); 

You can try it here (scroll to see the numbers change): http://jsfiddle.net/jfriend00/hxRPQ/

How can I check the syntax of Python script without executing it?

for some reason ( I am a py newbie ... ) the -m call did not work ...

so here is a bash wrapper func ...

# ---------------------------------------------------------
# check the python synax for all the *.py files under the
# <<product_version_dir/sfw/python
# ---------------------------------------------------------
doCheckPythonSyntax(){

    doLog "DEBUG START doCheckPythonSyntax"

    test -z "$sleep_interval" || sleep "$sleep_interval"
    cd $product_version_dir/sfw/python
    # python3 -m compileall "$product_version_dir/sfw/python"

    # foreach *.py file ...
    while read -r f ; do \

        py_name_ext=$(basename $f)
        py_name=${py_name_ext%.*}

        doLog "python3 -c \"import $py_name\""
        # doLog "python3 -m py_compile $f"

        python3 -c "import $py_name"
        # python3 -m py_compile "$f"
        test $! -ne 0 && sleep 5

    done < <(find "$product_version_dir/sfw/python" -type f -name "*.py")

    doLog "DEBUG STOP  doCheckPythonSyntax"
}
# eof func doCheckPythonSyntax

Combine several images horizontally with Python

my solution would be :

import sys
import os
from PIL import Image, ImageFilter
from PIL import ImageFont
from PIL import ImageDraw 

os.chdir('C:/Users/Sidik/Desktop/setup')
print(os.getcwd())

image_list= ['IMG_7292.jpg','IMG_7293.jpg','IMG_7294.jpg', 'IMG_7295.jpg' ]

image = [Image.open(x) for x in image_list]  # list
im_1 = image[0].rotate(270)
im_2 = image[1].rotate(270)
im_3 = image[2].rotate(270)
#im_4 = image[3].rotate(270)

height = image[0].size[0]
width = image[0].size[1]
# Create an empty white image frame
new_im = Image.new('RGB',(height*2,width*2),(255,255,255))

new_im.paste(im_1,(0,0))
new_im.paste(im_2,(height,0))
new_im.paste(im_3,(0,width))
new_im.paste(im_4,(height,width))


draw = ImageDraw.Draw(new_im)
font = ImageFont.truetype('arial',200)

draw.text((0, 0), '(a)', fill='white', font=font)
draw.text((height, 0), '(b)', fill='white', font=font)
draw.text((0, width), '(c)', fill='white', font=font)
#draw.text((height, width), '(d)', fill='white', font=font)

new_im.show()
new_im.save('BS1319.pdf')   
[![Laser spots on the edge][1]][1]

How to pass 2D array (matrix) in a function in C?

I don't know what you mean by "data dont get lost". Here's how you pass a normal 2D array to a function:

void myfunc(int arr[M][N]) { // M is optional, but N is required
  ..
}

int main() {
  int somearr[M][N];
  ...
  myfunc(somearr);
  ...
}

Maven: The packaging for this project did not assign a file to the build artifact

This reply is on a very old question to help others facing this issue.

I face this failed error while I were working on my Java project using IntelliJ IDEA IDE.

Failed to execute goal org.apache.maven.plugins:maven-install-plugin:2.4:install (default-cli) on project getpassword: The packaging for this project did not assign a file to the build artifact

this failed happens, when I choose install:install under Plugins - install, as pointed with red arrow in below image.

Choose Wrong Selection

Once I run the selected install under Lifecycle as illustrated above, the issue gone, and my maven install compile build successfully.

MAX() and MAX() OVER PARTITION BY produces error 3504 in Teradata Query

I think this will work even though this was forever ago.

SELECT employee_number, Row_Number()  
   OVER (PARTITION BY course_code ORDER BY course_completion_date DESC ) as rownum
FROM employee_course_completion
WHERE course_code IN ('M910303', 'M91301R', 'M91301P')
   AND rownum = 1

If you want to get the last Id if the date is the same then you can use this assuming your primary key is Id.

SELECT employee_number, Row_Number()  
   OVER (PARTITION BY course_code ORDER BY course_completion_date DESC, Id Desc) as rownum    FROM employee_course_completion
WHERE course_code IN ('M910303', 'M91301R', 'M91301P')
   AND rownum = 1

Update Query with INNER JOIN between tables in 2 different databases on 1 server

You could call it just style, but I prefer aliasing to improve readability.

UPDATE A    
  SET ControllingSalesRep = RA.SalesRepCode   
from DHE.dbo.tblAccounts A
  INNER JOIN DHE_Import.dbo.tblSalesRepsAccountsLink RA
    ON A.AccountCode = RA.AccountCode

For MySQL

UPDATE DHE.dbo.tblAccounts A 
  INNER JOIN DHE_Import.dbo.tblSalesRepsAccountsLink RA 
      ON A.AccountCode = RA.AccountCode 
SET A.ControllingSalesRep = RA.SalesRepCode

How to include multiple js files using jQuery $.getScript() method

You could make use of the $.when-method by trying the following function:

function loadScripts(scripts) {
  scripts.forEach(function (item, i) {
    item = $.getScript(item);
  });
  return $.when.apply($, scripts);
}

This function would be used like this:

loadScripts(['path/to/script-a.js', 'path/to/script-b.js']).done(function (respA, respB) {
    // both scripts are loaded; do something funny
});

That's the way to use Promises and have a minimum of overhead.

How to hide code from cells in ipython notebook visualized with nbviewer?

I would use hide_input_all from nbextensions (https://github.com/ipython-contrib/IPython-notebook-extensions). Here's how:

  1. Find out where your IPython directory is:

    from IPython.utils.path import get_ipython_dir
    print get_ipython_dir()
    
  2. Download nbextensions and move it to the IPython directory.

  3. Edit your custom.js file somewhere in the IPython directory (mine was in profile_default/static/custom) to be similar to the custom.example.js in the nbextensions directory.

  4. Add this line to custom.js:

    IPython.load_extensions('usability/hide_input_all')
    

IPython Notebook will now have a button to toggle code cells, no matter the workbook.

Using getline() with file input in C++

ifstream inFile;
string name, temp;
int age;

inFile.open("file.txt");

getline(inFile, name, ' '); // use ' ' as separator, default is '\n' (newline). Now name is "John".
getline(inFile, temp, ' '); // Now temp is "Smith"
name.append(1,' ');
name += temp;
inFile >> age; 

cout << name << endl;
cout << age << endl;  

inFile.close();    

AngularJS HTTP post to PHP and undefined

It took me hours to understand that while working with Angular and PHP. Post data was not going to PHP in $_POST

in PHP code do the following. - Create a variable $angular_post_params - Then do the following $angular_http_params = (array)json_decode(trim(file_get_contents('php://input')));

now you can access your parameters like you do from $_POST

$angular_http_params["key"]

in case you were wondering about javascript....this is what i used

    var myApp = angular.module('appUsers', []);
    //var post_params = $.param({ request_type: "getListOfUsersWithRolesInfo" });
    var dataObj = {
        task_to_perform: 'getListOfUsersWithRolesInfo'
    };

    myApp.controller('ctrlListOfUsers', function ($scope, $http) {
        $http({
            method: 'POST',
            dataType: 'json',
            url: ajax_processor_url,
            headers: {
                'Content-Type': 'application/json'
            },
            data: dataObj,
            //transformRequest: function(){},
            timeout: 30000,
            cache: false
        }).
        success(function (rsp) {
            console.log("success");
            console.log(rsp);
        }).
        error(function (rsp) {
            console.log("error");
        });
    });

Find a line in a file and remove it

    public void removeLineFromFile(String file, String lineToRemove) {

    try {

      File inFile = new File(file);

      if (!inFile.isFile()) {
        System.out.println("Parameter is not an existing file");
        return;
      }

      //Construct the new file that will later be renamed to the original filename.
      File tempFile = new File(inFile.getAbsolutePath() + ".tmp");

      BufferedReader br = new BufferedReader(new FileReader(file));
      PrintWriter pw = new PrintWriter(new FileWriter(tempFile));

      String line = null;

      //Read from the original file and write to the new
      //unless content matches data to be removed.
      while ((line = br.readLine()) != null) {

        if (!line.trim().equals(lineToRemove)) {

          pw.println(line);
          pw.flush();
        }
      }
      pw.close();
      br.close();

      //Delete the original file
      if (!inFile.delete()) {
        System.out.println("Could not delete file");
        return;
      }

      //Rename the new file to the filename the original file had.
      if (!tempFile.renameTo(inFile))
        System.out.println("Could not rename file");

    }
    catch (FileNotFoundException ex) {
      ex.printStackTrace();
    }
    catch (IOException ex) {
      ex.printStackTrace();
    }
  }

This I have found on the internet.

Getting SyntaxError for print with keyword argument end=' '

How about this:

#Only for use in Python 2.6.0a2 and later
from __future__ import print_function

This allows you to use the Python 3.0 style print function without having to hand-edit all occurrences of print :)

Stock ticker symbol lookup API

You can use the "Company Search" operation in the Company Fundamentals API here: http://www.mergent.com/servius/

How can I edit javascript in my browser like I can use Firebug to edit CSS/HTML?

I know that you can modify a javascript file when using Google Chrome.

  1. Open up Chrome Inspector, go to the "Scripts" tab.
  2. Press the drop-down menu and select the javascript file that you want to edit.
  3. Double click in the text field, type in what ever you want and delete whatever you want.
  4. Then all you have to do is press Ctrl + S to save the file.

Warning: If you refresh the page, all changes will go back to original file. I recommend to copy/paste the code somewhere else if you want to use it again.

Hope this helps!

Spring MVC - How to get all request params in a map in Spring controller?

While the other answers are correct it certainly is not the "Spring way" to use the HttpServletRequest object directly. The answer is actually quite simple and what you would expect if you're familiar with Spring MVC.

@RequestMapping(value = {"/search/", "/search"}, method = RequestMethod.GET)
public String search(
@RequestParam Map<String,String> allRequestParams, ModelMap model) {
   return "viewName";
}

How can I get the length of text entered in a textbox using jQuery?

If your textbox has an id attribute of "mytextbox", then you can get the length like this:

var myLength = $("#mytextbox").val().length;
  • $("#mytextbox") finds the textbox by its id.
  • .val() gets the value of the input element entered by the user, which is a string.
  • .length gets the number of characters in the string.

Find PHP version on windows command line

  1. Open cmd
  2. Type php -v

Output : PHP 5.6.30

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

You need add -> contentType: "application/json; charset=utf-8",

<script type="text/javascript">
    $(document).ready( function() {
      $('#btnTest').click( function() {
        $.ajax({
          type: "POST", 
          url: "/Login/Test",
          data: { ListID: '1', ItemName: 'test' },
          dataType: "json",
          contentType: "application/json; charset=utf-8",
          success: function(response) { alert(response); },
          error: function(xhr, ajaxOptions, thrownError) { alert(xhr.responseText); }
        });
      });
    });
</script>

Get Public URL for File - Google Cloud Storage - App Engine (Python)

You need to use get_serving_url from the Images API. As that page explains, you need to call create_gs_key() first to get the key to pass to the Images API.

Java project in Eclipse: The type java.lang.Object cannot be resolved. It is indirectly referenced from required .class files

I was facing this issue with play-java application on eclipse after adding a controller, I removed and reinstalled JRE through build path and then removed and imported my project which solved this issue automatically. Thanks gyro.

How do you kill a Thread in Java?

There is a way how you can do it. But if you had to use it, either you are a bad programmer or you are using a code written by bad programmers. So, you should think about stopping being a bad programmer or stopping using this bad code. This solution is only for situations when THERE IS NO OTHER WAY.

Thread f = <A thread to be stopped>
Method m = Thread.class.getDeclaredMethod( "stop0" , new Class[]{Object.class} );
m.setAccessible( true );
m.invoke( f , new ThreadDeath() );

Is there a method that calculates a factorial in Java?

Use Guava's BigIntegerMath as follows:

BigInteger factorial = BigIntegerMath.factorial(n);

(Similar functionality for int and long is available in IntMath and LongMath respectively.)

byte array to pdf

Usually this happens if something is wrong with the byte array.

File.WriteAllBytes("filename.PDF", Byte[]);

This creates a new file, writes the specified byte array to the file, and then closes the file. If the target file already exists, it is overwritten.

Asynchronous implementation of this is also available.

public static System.Threading.Tasks.Task WriteAllBytesAsync 
(string path, byte[] bytes, System.Threading.CancellationToken cancellationToken = null);

"Parameter" vs "Argument"

A parameter is the variable which is part of the method’s signature (method declaration). An argument is an expression used when calling the method.

Consider the following code:

void Foo(int i, float f)
{
    // Do things
}

void Bar()
{
    int anInt = 1;
    Foo(anInt, 2.0);
}

Here i and f are the parameters, and anInt and 2.0 are the arguments.

How to see tomcat is running or not

for localhost,the defaut port is 8080,you can test the link http://localhost:8080 in you browser.if you can see tomcat home page,your tomcat is running

Laravel redirect back to original destination after login

For Laravel 5.3 and above

Check Scott's answer below.

For Laravel 5 up to 5.2

Simply put,

On auth middleware:

// redirect the user to "/login"
// and stores the url being accessed on session
if (Auth::guest()) {
    return redirect()->guest('login');
}
return $next($request);

On login action:

// redirect the user back to the intended page
// or defaultpage if there isn't one
if (Auth::attempt(['email' => $email, 'password' => $password])) {
    return redirect()->intended('defaultpage');
}

For Laravel 4 (old answer)

At the time of this answer there was no official support from the framework itself. Nowadays you can use the method pointed out by bgdrl below this method: (I've tried updating his answer, but it seems he won't accept)

On auth filter:

// redirect the user to "/login"
// and stores the url being accessed on session
Route::filter('auth', function() {
    if (Auth::guest()) {
        return Redirect::guest('login');
    }
});

On login action:

// redirect the user back to the intended page
// or defaultpage if there isn't one
if (Auth::attempt(['email' => $email, 'password' => $password])) {
    return Redirect::intended('defaultpage');
}

For Laravel 3 (even older answer)

You could implement it like this:

Route::filter('auth', function() {
    // If there's no user authenticated session
    if (Auth::guest()) {
        // Stores current url on session and redirect to login page
        Session::put('redirect', URL::full());
        return Redirect::to('/login');
    }
    if ($redirect = Session::get('redirect')) {
        Session::forget('redirect');
        return Redirect::to($redirect);
    }
});
// on controller
public function get_login()
{
    $this->layout->nest('content', 'auth.login'); 
}

public function post_login()
{
    $credentials = [
        'username' => Input::get('email'),
        'password' => Input::get('password')
    ];

    if (Auth::attempt($credentials)) {
        return Redirect::to('logged_in_homepage_here');
    }

    return Redirect::to('login')->with_input();
}

Storing the redirection on Session has the benefit of persisting it even if the user miss typed his credentials or he doesn't have an account and has to signup.

This also allows for anything else besides Auth to set a redirect on session and it will work magically.

When creating a service with sc.exe how to pass in context parameters?

I had issues getting this to work on Windows 7. It seemed to ignore the first argument I passed in so I used binPath= "C:\path\to\service.exe -bogusarg -realarg1 -realarg2" and it worked.

jQuery validate: How to add a rule for regular expression validation?

You can use the addMethod()

e.g

$.validator.addMethod('postalCode', function (value) { 
    return /^((\d{5}-\d{4})|(\d{5})|([A-Z]\d[A-Z]\s\d[A-Z]\d))$/.test(value); 
}, 'Please enter a valid US or Canadian postal code.');

good article here https://web.archive.org/web/20130609222116/http://www.randallmorey.com/blog/2008/mar/16/extending-jquery-form-validation-plugin/

Oracle 11g Express Edition for Windows 64bit?

Oracle 11G Express Edition is now available to install on 64-bit versions of Windows.

Oracle 11G Download Page

Most efficient way to see if an ArrayList contains an object in Java

You could use a Comparator with Java's built-in methods for sorting and binary search. Suppose you have a class like this, where a and b are the fields you want to use for sorting:

class Thing { String a, b, c, d; }

You would define your Comparator:

Comparator<Thing> comparator = new Comparator<Thing>() {
  public int compare(Thing o1, Thing o2) {
    if (o1.a.equals(o2.a)) {
      return o1.b.compareTo(o2.b);
    }
    return o1.a.compareTo(o2.a);
  }
};

Then sort your list:

Collections.sort(list, comparator);

And finally do the binary search:

int i = Collections.binarySearch(list, thingToFind, comparator);

Why is exception.printStackTrace() considered bad practice?

Throwable.printStackTrace() writes the stack trace to System.err PrintStream. The System.err stream and the underlying standard "error" output stream of the JVM process can be redirected by

  • invoking System.setErr() which changes the destination pointed to by System.err.
  • or by redirecting the process' error output stream. The error output stream may be redirected to a file/device
    • whose contents may be ignored by personnel,
    • the file/device may not be capable of log rotation, inferring that a process restart is required to close the open file/device handle, before archiving the existing contents of the file/device.
    • or the file/device actually discards all data written to it, as is the case of /dev/null.

Inferring from the above, invoking Throwable.printStackTrace() constitutes valid (not good/great) exception handling behavior, only

  • if you do not have System.err being reassigned throughout the duration of the application's lifetime,
  • and if you do not require log rotation while the application is running,
  • and if accepted/designed logging practice of the application is to write to System.err (and the JVM's standard error output stream).

In most cases, the above conditions are not satisfied. One may not be aware of other code running in the JVM, and one cannot predict the size of the log file or the runtime duration of the process, and a well designed logging practice would revolve around writing "machine-parseable" log files (a preferable but optional feature in a logger) in a known destination, to aid in support.

Finally, one ought to remember that the output of Throwable.printStackTrace() would definitely get interleaved with other content written to System.err (and possibly even System.out if both are redirected to the same file/device). This is an annoyance (for single-threaded apps) that one must deal with, for the data around exceptions is not easily parseable in such an event. Worse, it is highly likely that a multi-threaded application will produce very confusing logs as Throwable.printStackTrace() is not thread-safe.

There is no synchronization mechanism to synchronize the writing of the stack trace to System.err when multiple threads invoke Throwable.printStackTrace() at the same time. Resolving this actually requires your code to synchronize on the monitor associated with System.err (and also System.out, if the destination file/device is the same), and that is rather heavy price to pay for log file sanity. To take an example, the ConsoleHandler and StreamHandler classes are responsible for appending log records to console, in the logging facility provided by java.util.logging; the actual operation of publishing log records is synchronized - every thread that attempts to publish a log record must also acquire the lock on the monitor associated with the StreamHandler instance. If you wish to have the same guarantee of having non-interleaved log records using System.out/System.err, you must ensure the same - the messages are published to these streams in a serializable manner.

Considering all of the above, and the very restricted scenarios in which Throwable.printStackTrace() is actually useful, it often turns out that invoking it is a bad practice.


Extending the argument in the one of the previous paragraphs, it is also a poor choice to use Throwable.printStackTrace in conjunction with a logger that writes to the console. This is in part, due to the reason that the logger would synchronize on a different monitor, while your application would (possibly, if you don't want interleaved log records) synchronize on a different monitor. The argument also holds good when you use two different loggers that write to the same destination, in your application.

Python: No acceptable C compiler found in $PATH when installing python

If you are using alphine with docker, do this:

apk --update add gcc make g++ zlib-dev

What is the recommended way to delete a large number of items from DynamoDB?

We don't have option to truncate dynamo tables. we have to drop the table and create again . DynamoDB Charges are based on ReadCapacityUnits & WriteCapacityUnits . If we delete all items using BatchWriteItem function, it will use WriteCapacityUnits.So better to delete specific records or delete the table and start again .

Error:(1, 0) Plugin with id 'com.android.application' not found

In my case, I download the project from GitHub and the Gradle file was missing. So I just create a new project with success build. Then copy-paste the Gradle missing file. And re-build the project is working for me.

enter image description here

jQuery - hashchange event

Use Modernizr for detection of feature capabilities. In general jQuery offers to detect browser features: http://api.jquery.com/jQuery.support/. However, hashchange is not on the list.

The wiki of Modernizr offers a list of libraries to add HTML5 capabilities to old browsers. The list for hashchange includes a pointer to the project HTML5 History API, which seems to offer the functionality you would need if you wanted to emulate the behavior in old browsers.

How to target only IE (any version) within a stylesheet?

Internet Explorer 9 and lower : You could use conditional comments to load an IE-specific stylesheet for any version (or combination of versions) that you wanted to specifically target.like below using external stylesheet.

<!--[if IE]>
  <link rel="stylesheet" type="text/css" href="all-ie-only.css" />
<![endif]-->

However, beginning in version 10, conditional comments are no longer supported in IE.

Internet Explorer 10 & 11 : Create a media query using -ms-high-contrast, in which you place your IE 10 and 11-specific CSS styles. Because -ms-high-contrast is Microsoft-specific (and only available in IE 10+), it will only be parsed in Internet Explorer 10 and greater.

@media all and (-ms-high-contrast: none), (-ms-high-contrast: active) {
     /* IE10+ CSS styles go here */
}

Microsoft Edge 12 : Can use the @supports rule Here is a link with all the info about this rule

@supports (-ms-accelerator:true) {
  /* IE Edge 12+ CSS styles go here */ 
}

Inline rule IE8 detection

I have 1 more option but it is only detect IE8 and below version.

  /* For IE css hack */
  margin-top: 10px\9 /* apply to all ie from 8 and below */
  *margin-top:10px;  /* apply to ie 7 and below */
  _margin-top:10px; /* apply to ie 6 and below */

As you specefied for embeded stylesheet. I think you need to use media query and condition comment for below version.

Getting Image from URL (Java)

This code worked fine for me.

 import java.io.FileOutputStream;
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.OutputStream;
 import java.net.URL;

public class SaveImageFromUrl {

public static void main(String[] args) throws Exception {
    String imageUrl = "http://www.avajava.com/images/avajavalogo.jpg";
    String destinationFile = "image.jpg";

    saveImage(imageUrl, destinationFile);
}

public static void saveImage(String imageUrl, String destinationFile) throws IOException {
    URL url = new URL(imageUrl);
    InputStream is = url.openStream();
    OutputStream os = new FileOutputStream(destinationFile);

    byte[] b = new byte[2048];
    int length;

    while ((length = is.read(b)) != -1) {
        os.write(b, 0, length);
    }

    is.close();
    os.close();
}

}

How to use custom packages

I am an experienced programmer, but, quite new into Go world ! And I confess I've faced few difficulties to understand Go... I faced this same problem when trying to organize my go files in sub-folders. The way I did it :

GO_Directory ( the one assigned to $GOPATH )

GO_Directory //the one assigned to $GOPATH
__MyProject
_____ main.go
_____ Entites
_____ Fiboo // in my case, fiboo is a database name
_________ Client.go // in my case, Client is a table name

On File MyProject\Entities\Fiboo\Client.go

package Fiboo

type Client struct{
    ID int
    name string
}

on file MyProject\main.go

package main

import(
    Fiboo "./Entity/Fiboo" 
)

var TableClient  Fiboo.Client

func main(){
    TableClient.ID = 1
    TableClient.name = 'Hugo'

    // do your things here
}

( I am running Go 1.9 on Ubuntu 16.04 )

And remember guys, I am newbie on Go. If what I am doing is bad practice, let me know !

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

The title of the question and the content is actually different, so I will post two solutions for that using Flexbox.

I guess Flexbox will replace/add to the current standard solution by the time IE8 and IE9 is completely destroyed ;)

Check the current Browser compatibility table for flexbox

Single element

_x000D_
_x000D_
.container {_x000D_
  display: flex;_x000D_
  justify-content: center;_x000D_
}
_x000D_
<div class="container">_x000D_
  <img src="http://placehold.it/100x100">_x000D_
</div>
_x000D_
_x000D_
_x000D_

Multiple elements but center only one

Default behaviour is flex-direction: row which will align all the child items in a single line. Setting it to flex-direction: column will help the lines to be stacked.

_x000D_
_x000D_
.container {_x000D_
  display: flex;_x000D_
  flex-direction: column;_x000D_
}_x000D_
.centered {_x000D_
  align-self: center;_x000D_
}
_x000D_
<div class="container">_x000D_
  <p>Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industry's standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book. It has survived not only five centuries, but also the leap into electronic typesetting, remaining essentially unchanged._x000D_
   </p>_x000D_
  <div class="centered"><img src="http://placehold.it/100x100"></div>_x000D_
  <p>Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industry's standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book. It_x000D_
    has survived not only five centuries, but also the leap into electronic typesetting, remaining essentially unchanged. </p>_x000D_
</div>
_x000D_
_x000D_
_x000D_

How to change MySQL data directory?

Everything as @user1341296 said, plus...

You better not to change /etc/mysql/my.cnf Instead you want to create new file/etc/mysql/conf.d/ext.cnf (any name, but extension should be cnf)

And put in it your change:

[mysqld]
datadir=/vagrant/mq/mysql

In this way

  • You do not need to change existing file (easier for automation scripts)
  • No problems with MySQL version (and it's configs!) update.

UITextView that expands to text using auto layout

I see multiple answers suggest simply turning off scrollEnabled. This is the best solution. I’m writing this answer to explain why it works.

UITextView implements the intrinsicContentSize property if scrollEnabled == NO. The disassembly of the getter method looks like this:

- (CGSize)intrinsicContentSize {
  if (self.scrollEnabled) {
    return CGSizeMake(UIViewNoIntrinsicMetric, UIViewNoIntrinsicMetric);
  } else {
    // Calculate and return intrinsic content size based on current width.
  }
}

That means you just need to make sure the width of the text view is constrained enough and then you can use the intrinsic content height (either via Auto Layout content hugging/compression resistance priorities or directly using the value during manual layout).

Unfortunately, this behavior is not documented. Apple could have easily saved us all some headaches… no need for an extra height constraint, subclassing, etc.

Simplest SOAP example

<html>
 <head>
    <title>Calling Web Service from jQuery</title>
    <script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.4.3/jquery.min.js"></script>
    <script type="text/javascript">
        $(document).ready(function () {
            $("#btnCallWebService").click(function (event) {
                var wsUrl = "http://abc.com/services/soap/server1.php";
                var soapRequest ='<soap:Envelope xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/">   <soap:Body> <getQuote xmlns:impl="http://abc.com/services/soap/server1.php">  <symbol>' + $("#txtName").val() + '</symbol>   </getQuote> </soap:Body></soap:Envelope>';
                               alert(soapRequest)
                $.ajax({
                    type: "POST",
                    url: wsUrl,
                    contentType: "text/xml",
                    dataType: "xml",
                    data: soapRequest,
                    success: processSuccess,
                    error: processError
                });

            });
        });

        function processSuccess(data, status, req) { alert('success');
            if (status == "success")
                $("#response").text($(req.responseXML).find("Result").text());

                alert(req.responseXML);
        }

        function processError(data, status, req) {
        alert('err'+data.state);
            //alert(req.responseText + " " + status);
        } 

    </script>
</head>
<body>
    <h3>
        Calling Web Services with jQuery/AJAX
    </h3>
    Enter your name:
    <input id="txtName" type="text" />
    <input id="btnCallWebService" value="Call web service" type="button" />
    <div id="response" ></div>
</body>
</html>

Hear is best JavaScript with SOAP tutorial with example.

http://www.codeproject.com/Articles/12816/JavaScript-SOAP-Client

svn : how to create a branch from certain revision of trunk

Try below one:

svn copy http://svn.example.com/repos/calc/trunk@rev-no 
       http://svn.example.com/repos/calc/branches/my-calc-branch 
  -m "Creating a private branch of /calc/trunk."  --parents

No slash "\" between the svn URLs.

What is time_t ultimately a typedef to?

It's a 32-bit signed integer type on most legacy platforms. However, that causes your code to suffer from the year 2038 bug. So modern C libraries should be defining it to be a signed 64-bit int instead, which is safe for a few billion years.

How to get a list of properties with a given attribute?

If you deal regularly with Attributes in Reflection, it is very, very practical to define some extension methods. You will see that in many projects out there. This one here is one I often have:

public static bool HasAttribute<T>(this ICustomAttributeProvider provider) where T : Attribute
{
  var atts = provider.GetCustomAttributes(typeof(T), true);
  return atts.Length > 0;
}

which you can use like typeof(Foo).HasAttribute<BarAttribute>();

Other projects (e.g. StructureMap) have full-fledged ReflectionHelper classes that use Expression trees to have a fine syntax to identity e.g. PropertyInfos. Usage then looks like that:

ReflectionHelper.GetProperty<Foo>(x => x.MyProperty).HasAttribute<BarAttribute>()

what is the use of Eval() in asp.net

Eval is used to bind to an UI item that is setup to be read-only (eg: a label or a read-only text box), i.e., Eval is used for one way binding - for reading from a database into a UI field.

It is generally used for late-bound data (not known from start) and usually bound to the smallest part of the data-bound control that contains a whole record. The Eval method takes the name of a data field and returns a string containing the value of that field from the current record in the data source. You can supply an optional second parameter to specify a format for the returned string. The string format parameter uses the syntax defined for the Format method of the String class.

Setting Different Bar color in matplotlib Python

Simple, just use .set_color

>>> barlist=plt.bar([1,2,3,4], [1,2,3,4])
>>> barlist[0].set_color('r')
>>> plt.show()

enter image description here

For your new question, not much harder either, just need to find the bar from your axis, an example:

>>> f=plt.figure()
>>> ax=f.add_subplot(1,1,1)
>>> ax.bar([1,2,3,4], [1,2,3,4])
<Container object of 4 artists>
>>> ax.get_children()
[<matplotlib.axis.XAxis object at 0x6529850>, 
 <matplotlib.axis.YAxis object at 0x78460d0>,  
 <matplotlib.patches.Rectangle object at 0x733cc50>, 
 <matplotlib.patches.Rectangle object at 0x733cdd0>, 
 <matplotlib.patches.Rectangle object at 0x777f290>, 
 <matplotlib.patches.Rectangle object at 0x777f710>, 
 <matplotlib.text.Text object at 0x7836450>, 
 <matplotlib.patches.Rectangle object at 0x7836390>, 
 <matplotlib.spines.Spine object at 0x6529950>, 
 <matplotlib.spines.Spine object at 0x69aef50>,
 <matplotlib.spines.Spine object at 0x69ae310>, 
 <matplotlib.spines.Spine object at 0x69aea50>]
>>> ax.get_children()[2].set_color('r') 
 #You can also try to locate the first patches.Rectangle object 
 #instead of direct calling the index.

If you have a complex plot and want to identify the bars first, add those:

>>> import matplotlib
>>> childrenLS=ax.get_children()
>>> barlist=filter(lambda x: isinstance(x, matplotlib.patches.Rectangle), childrenLS)
[<matplotlib.patches.Rectangle object at 0x3103650>, 
 <matplotlib.patches.Rectangle object at 0x3103810>, 
 <matplotlib.patches.Rectangle object at 0x3129850>, 
 <matplotlib.patches.Rectangle object at 0x3129cd0>, 
 <matplotlib.patches.Rectangle object at 0x3112ad0>]

Certificate is trusted by PC but not by Android

I had the same problem. Another way to generate the correct .crt file is like this:

Sometimes you get a .PEM file with an entire certificate chain inside. The file may look like this....

-----BEGIN RSA PRIVATE KEY-----
blablablabase64private...
-----END RSA PRIVATE KEY-----
-----BEGIN CERTIFICATE-----
blablablabase64CRT1...
-----END CERTIFICATE-----
-----BEGIN CERTIFICATE-----
blablablabase64CRT2...
-----END CERTIFICATE-----
...

If you remove the entire private key section, you will have a valid chained .crt

Django DateField default options

Your mistake is using the datetime module instead of the date module. You meant to do this:

from datetime import date
date = models.DateField(_("Date"), default=date.today)

If you only want to capture the current date the proper way to handle this is to use the auto_now_add parameter:

date = models.DateField(_("Date"), auto_now_add=True)

However, the modelfield docs clearly state that auto_now_add and auto_now will always use the current date and are not a default value that you can override.

IOS 7 Navigation Bar text and arrow color

It seems that Accessibility controls in the iOS Settings override pretty much everything you try to do color-wise to the navigation bar buttons. Make sure you have all the settings to the default positions (set increase contrast, bold text, button shapes, etc to off) otherwise you won't see anything change. Once I did it, all the color change code started working as expected. You might not need to turn them all off, but I didn't pursue it further.

random number generator between 0 - 1000 in c#

Use this:

static int RandomNumber(int min, int max)
{
    Random random = new Random(); return random.Next(min, max);

}

This is example for you to modify and use in your application.

CORS with POSTMAN

CORS (Cross-Origin Resource Sharing) and SOP (Same-Origin Policy) are server-side configurations that clients decide to enforce or not.

Related to clients

  • Most Browsers do enforce it to prevent issues related to CSRF attack.
  • Most Development tools don't care about it.

How to make <input type="date"> supported on all browsers? Any alternatives?

Chrome Version 50.0.2661.87 m does not support the mm-dd-yy format when assigned to a variable. It uses yy-mm-dd. IE and Firefox work as expected.

How do I reverse a commit in git?

I think you need to push a revert commit. So pull from github again, including the commit you want to revert, then use git revert and push the result.

If you don't care about other people's clones of your github repository being broken, you can also delete and recreate the master branch on github after your reset: git push origin :master.

find all the name using mysql query which start with the letter 'a'

Try this:

select * from artists where name like "A%" or name like "B%" or name like "C%"

SQL Server : error converting data type varchar to numeric

There's no guarantee that SQL Server won't attempt to perform the CONVERT to numeric(20,0) before it runs the filter in the WHERE clause.

And, even if it did, ISNUMERIC isn't adequate, since it recognises £ and 1d4 as being numeric, neither of which can be converted to numeric(20,0).(*)

Split it into two separate queries, the first of which filters the results and places them in a temp table or table variable, the second of which performs the conversion. (Subqueries and CTEs are inadequate to prevent the optimizer from attempting the conversion before the filter)

For your filter, probably use account_code not like '%[^0-9]%' instead of ISNUMERIC.


(*) ISNUMERIC answers the question that no-one (so far as I'm aware) has ever wanted to ask - "can this string be converted to any of the numeric datatypes - I don't care which?" - when obviously, what most people want to ask is "can this string be converted to x?" where x is a specific target datatype.

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

So after struggling with this issue for quite some time, this is what could help you:

from PIL import Image

instead of

import Image

Also, if your Image file is not loading and you're getting an error "No file or directory" then you should do this:

path=r'C:\ABC\Users\Pictures\image.jpg'

and then open the file

image=Image.open(path)

C# naming convention for constants?

I still go with the uppercase for const values, but this is more out of habit than for any particular reason.

Of course it makes it easy to see immediately that something is a const. The question to me is: Do we really need this information? Does it help us in any way to avoid errors? If I assign a value to the const, the compiler will tell me I did something dumb.

My conclusion: Go with the camel casing. Maybe I will change my style too ;-)

Edit:

That something smells hungarian is not really a valid argument, IMO. The question should always be: Does it help, or does it hurt?

There are cases when hungarian helps. Not that many nowadays, but they still exist.

Change windows hostname from command line

The netdom.exe command line program can be used. This is available from the Windows XP Support Tools or Server 2003 Support Tools (both on the installation CD).

Usage guidelines here

Using Helvetica Neue in a Website

I'd recommend this article on CSS Tricks by Chris Coyier entitled Better Helvetica:

http://css-tricks.com/snippets/css/better-helvetica/

He basically recommends the following declaration for covering all the bases:

body {
    font-family: "HelveticaNeue-Light", "Helvetica Neue Light", "Helvetica Neue", Helvetica, Arial, "Lucida Grande", sans-serif; 
    font-weight: 300;
}

Disable copy constructor

You can make the copy constructor private and provide no implementation:

private:
    SymbolIndexer(const SymbolIndexer&);

Or in C++11, explicitly forbid it:

SymbolIndexer(const SymbolIndexer&) = delete;

find vs find_by vs where

Model.find

1- Parameter: ID of the object to find.

2- If found: It returns the object (One object only).

3- If not found: raises an ActiveRecord::RecordNotFound exception.

Model.find_by

1- Parameter: key/value

Example:

User.find_by name: 'John', email: '[email protected]'

2- If found: It returns the object.

3- If not found: returns nil.

Note: If you want it to raise ActiveRecord::RecordNotFound use find_by!

Model.where

1- Parameter: same as find_by

2- If found: It returns ActiveRecord::Relation containing one or more records matching the parameters.

3- If not found: It return an Empty ActiveRecord::Relation.

How to iterate through SparseArray?

The accepted answer has some holes in it. The beauty of the SparseArray is that it allows gaps in the indeces. So, we could have two maps like so, in a SparseArray...

(0,true)
(250,true)

Notice the size here would be 2. If we iterate over size, we will only get values for the values mapped to index 0 and index 1. So the mapping with a key of 250 is not accessed.

for(int i = 0; i < sparseArray.size(); i++) {
   int key = sparseArray.keyAt(i);
   // get the object by the key.
   Object obj = sparseArray.get(key);
}

The best way to do this is to iterate over the size of your data set, then check those indeces with a get() on the array. Here is an example with an adapter where I am allowing batch delete of items.

for (int index = 0; index < mAdapter.getItemCount(); index++) {
     if (toDelete.get(index) == true) {
        long idOfItemToDelete = (allItems.get(index).getId());
        mDbManager.markItemForDeletion(idOfItemToDelete);
        }
    }

I think ideally the SparseArray family would have a getKeys() method, but alas it does not.

Format JavaScript date as yyyy-mm-dd

Retrieve year, month, and day, and then put them together. Straight, simple, and accurate.

_x000D_
_x000D_
function formatDate(date) {_x000D_
    var year = date.getFullYear().toString();_x000D_
    var month = (date.getMonth() + 101).toString().substring(1);_x000D_
    var day = (date.getDate() + 100).toString().substring(1);_x000D_
    return year + "-" + month + "-" + day;_x000D_
}_x000D_
_x000D_
//Usage example:_x000D_
alert(formatDate(new Date()));
_x000D_
_x000D_
_x000D_

max value of integer

A 32 bit integer ranges from -2,147,483,648 to 2,147,483,647. However the fact that you are on a 32-bit machine does not mean your C compiler uses 32-bit integers.

How do I force a DIV block to extend to the bottom of a page even if it has no content?

While it isn't as elegant as pure CSS, a small bit of javascript can help accomplish this:

<html>
<head>
<style type='text/css'>
    div {
        border: 1px solid #000000;
    } 
</style>
<script type='text/javascript'>

    function expandToWindow(element) {
         var margin = 10; 

         if (element.style.height < window.innerHeight) { 
            element.style.height = window.innerHeight - (2 * margin) 
         }
    }


</script>
</head>
<body onload='expandToWindow(document.getElementById("content"));'>
<div id='content'>Hello World</div>
</body>
</html>

Table header to stay fixed at the top when user scrolls it out of view with jQuery

I have tried it using transformation:translate. While it works good in Firefox and Chrome, there is simply no function in IE11. No double scroll bars. Supports table tfoot and caption. Pure Javascript, no jQuery.

http://jsfiddle.net/wbLqzrfb/42/

thead.style.transform="translate(0,"+(dY-top-1)+"px)";

How to connect Android app to MySQL database?

Yes you can connect your android app to your PHP to grab results from your database. Use a webservice to connect to your backend script via ASYNC task and http post requests. Check this link for more information Connecting to MySQL

Excel compare two columns and highlight duplicates

There may be a simpler option, but you can use VLOOKUP to check if a value appears in a list (and VLOOKUP is a powerful formula to get to grips with anyway).

So for A1, you can set a conditional format using the following formula:

=NOT(ISNA(VLOOKUP(A1,$B:$B,1,FALSE)))

Copy and Paste Special > Formats to copy that conditional format to the other cells in column A.

What the above formula is doing:

  • VLOOKUP is looking up the value of Cell A1 (first parameter) against the whole of column B ($B:$B), in the first column (that's the 3rd parameter, redundant here, but typically VLOOKUP looks up a table rather than a column). The last parameter, FALSE, specifies that the match must be exact rather than just the closest match.
  • VLOOKUP will return #ISNA if no match is found, so the NOT(ISNA(...)) returns true for all cells which have a match in column B.

Granting DBA privileges to user in Oracle

You need only to write:

GRANT DBA TO NewDBA;

Because this already makes the user a DB Administrator

Oracle's default date format is YYYY-MM-DD, WHY?

reason: if you are looking at a column of data with a time stamp, the _MOST_IMPORTANT_ bit of information is the year. If data has been in the db for ten years, that's important to know. so year comes first.

it makes sense that month would come next, then day, hour, minute. Objectively, these are the most logical sequence for time data to be displayed.

it also makes sense that if you are going to display the data by default, you should display only the most significant portion of the data, so by default, only Y-M-D. everything else CAN be displayed, but it does not clutter your sql report by default.

Ordering by date is logical if you display Y-M-D because it is sequential. Computers are good at sequential, and it looks logical.

finally. Your bias to want M-D-Y is your bias. Not everyone even in the US uses this format. So use the most logical format and don't be outraged when others decide to be logical by default.

(I am US born, and I do not represent Oracle. I can, however, think for myself)

What is the difference between Views and Materialized Views in Oracle?

A view uses a query to pull data from the underlying tables.

A materialized view is a table on disk that contains the result set of a query.

Materialized views are primarily used to increase application performance when it isn't feasible or desirable to use a standard view with indexes applied to it. Materialized views can be updated on a regular basis either through triggers or by using the ON COMMIT REFRESH option. This does require a few extra permissions, but it's nothing complex. ON COMMIT REFRESH has been in place since at least Oracle 10.

Truth value of a Series is ambiguous. Use a.empty, a.bool(), a.item(), a.any() or a.all()

I'll try to give the benchmark of the three most common way (also mentioned above):

from timeit import repeat

setup = """
import numpy as np;
import random;
x = np.linspace(0,100);
lb, ub = np.sort([random.random() * 100, random.random() * 100]).tolist()
"""
stmts = 'x[(x > lb) * (x <= ub)]', 'x[(x > lb) & (x <= ub)]', 'x[np.logical_and(x > lb, x <= ub)]'

for _ in range(3):
    for stmt in stmts:
        t = min(repeat(stmt, setup, number=100_000))
        print('%.4f' % t, stmt)
    print()

result:

0.4808 x[(x > lb) * (x <= ub)]
0.4726 x[(x > lb) & (x <= ub)]
0.4904 x[np.logical_and(x > lb, x <= ub)]

0.4725 x[(x > lb) * (x <= ub)]
0.4806 x[(x > lb) & (x <= ub)]
0.5002 x[np.logical_and(x > lb, x <= ub)]

0.4781 x[(x > lb) * (x <= ub)]
0.4336 x[(x > lb) & (x <= ub)]
0.4974 x[np.logical_and(x > lb, x <= ub)]

But, * is not supported in Panda Series, and NumPy Array is faster than pandas data frame (arround 1000 times slower, see number):

from timeit import repeat

setup = """
import numpy as np;
import random;
import pandas as pd;
x = pd.DataFrame(np.linspace(0,100));
lb, ub = np.sort([random.random() * 100, random.random() * 100]).tolist()
"""
stmts = 'x[(x > lb) & (x <= ub)]', 'x[np.logical_and(x > lb, x <= ub)]'

for _ in range(3):
    for stmt in stmts:
        t = min(repeat(stmt, setup, number=100))
        print('%.4f' % t, stmt)
    print()

result:

0.1964 x[(x > lb) & (x <= ub)]
0.1992 x[np.logical_and(x > lb, x <= ub)]

0.2018 x[(x > lb) & (x <= ub)]
0.1838 x[np.logical_and(x > lb, x <= ub)]

0.1871 x[(x > lb) & (x <= ub)]
0.1883 x[np.logical_and(x > lb, x <= ub)]

Note: adding one line of code x = x.to_numpy() will need about 20 µs.

For those who prefer %timeit:

import numpy as np
import random
lb, ub = np.sort([random.random() * 100, random.random() * 100]).tolist()
lb, ub
x = pd.DataFrame(np.linspace(0,100))

def asterik(x):
    x = x.to_numpy()
    return x[(x > lb) * (x <= ub)]

def and_symbol(x):
    x = x.to_numpy()
    return x[(x > lb) & (x <= ub)]

def numpy_logical(x):
    x = x.to_numpy()
    return x[np.logical_and(x > lb, x <= ub)]

for i in range(3):
    %timeit asterik(x)
    %timeit and_symbol(x)
    %timeit numpy_logical(x)
    print('\n')

result:

23 µs ± 3.62 µs per loop (mean ± std. dev. of 7 runs, 10000 loops each)
35.6 µs ± 9.53 µs per loop (mean ± std. dev. of 7 runs, 100000 loops each)
31.3 µs ± 8.9 µs per loop (mean ± std. dev. of 7 runs, 100000 loops each)


21.4 µs ± 3.35 µs per loop (mean ± std. dev. of 7 runs, 10000 loops each)
21.9 µs ± 1.02 µs per loop (mean ± std. dev. of 7 runs, 100000 loops each)
21.7 µs ± 500 ns per loop (mean ± std. dev. of 7 runs, 100000 loops each)


25.1 µs ± 3.71 µs per loop (mean ± std. dev. of 7 runs, 100000 loops each)
36.8 µs ± 18.3 µs per loop (mean ± std. dev. of 7 runs, 100000 loops each)
28.2 µs ± 5.97 µs per loop (mean ± std. dev. of 7 runs, 10000 loops each)