Programs & Examples On #Trayicon

for questions about creating a tray icon for a software application, customising the behaviour of a tray icon, and adding application control or monitoring to a tray icon. For questions which relate the system notification area or system tray in general, use the notification-area or system-tray tag instead.

Unit Tests not discovered in Visual Studio 2017

Removing old .dll should help. Clearing temp files located in the %TEMP% directory at C:\Users(yourusername)\AppData\Local\Temp

Importing modules from parent folder

Above mentioned solutions are also fine. Another solution to this problem is

If you want to import anything from top level directory. Then,

from ...module_name import *

Also, if you want to import any module from the parent directory. Then,

from ..module_name import *

Also, if you want to import any module from the parent directory. Then,

from ...module_name.another_module import *

This way you can import any particular method if you want to.

What does git rev-parse do?

Just to elaborate on the etymology of the command name rev-parse, Git consistently uses the term rev in plumbing commands as short for "revision" and generally meaning the 40-character SHA1 hash for a commit. The command rev-list for example prints a list of 40-char commit hashes for a branch or whatever.

In this case the name might be expanded to parse-a-commitish-to-a-full-SHA1-hash. While the command has the several ancillary functions mentioned in Tuxdude's answer, its namesake appears to be the use case of transforming a user-friendly reference like a branch name or abbreviated hash into the unambiguous 40-character SHA1 hash most useful for many programming/plumbing purposes.

I know I was thinking it was "reverse-parse" something for quite a while before I figured it out and had the same trouble making sense of the terms "massaging" and "manipulation" :)

Anyway, I find this "parse-to-a-revision" notion a satisfying way to think of it, and a reliable concept for bringing this command to mind when I need that sort of thing. Frequently in scripting Git you take a user-friendly commit reference as user input and generally want to get it resolved to a validated and unambiguous working reference as soon after receiving it as possible. Otherwise input translation and validation tends to proliferate through the script.

What do 1.#INF00, -1.#IND00 and -1.#IND mean?

Your question "what are they" is already answered above.

As far as debugging (your second question) though, and in developing libraries where you want to check for special input values, you may find the following functions useful in Windows C++:

_isnan(), _isfinite(), and _fpclass()

On Linux/Unix you should find isnan(), isfinite(), isnormal(), isinf(), fpclassify() useful (and you may need to link with libm by using the compiler flag -lm).

Easier way to create circle div than using an image?

Give width and height depending on the size but,keep both equal

_x000D_
_x000D_
.circle {_x000D_
  background-color: gray;_x000D_
  height: 400px;_x000D_
  width: 400px;_x000D_
  border-radius: 100%;_x000D_
}
_x000D_
<div class="circle">_x000D_
</div>
_x000D_
_x000D_
_x000D_

Could not load file or assembly 'System.Data.SQLite'

You likely have the wrong package installed. You want the package produced by Microsoft which implements the System.Data.Common provider model.

How can I convert a std::string to int?

 int stringToInt(std::string value) {    
 if(value.length() == 0 ) return 0; //tu zmiana..

 if (value.find(  std::string("NULL") ) != std::string::npos) {
     return 0;
  }
 
  if (value.find(  std::string("null") ) != std::string::npos) {
     return 0;
  }
 
 
int i;
std::stringstream stream1;
stream1.clear();
stream1.str(value);
stream1 >> i;
return i;

};

How to use UIScrollView in Storyboard

Note that within a UITableView, you can actually scroll the tableview by selecting a cell or an element in it and scrolling up or down with your trackpad.

For a UIScrollView, I like Alex's suggestion, but I would recommend temporarily changing the view controller to freeform, increasing the root view's height, building your UI (steps 1-5), and then changing it back to the standard inferred size when you are done so that you don't have to hard code content sizes in as runtime attributes. If you do that you are opening yourself up to a lot of maintenance issues trying to support both 3.5" and 4" devices, as well as the possibility of increased screen resolutions in the future.

wget command to download a file and save as a different filename

Also notice the order of parameters on the command line. At least on some systems (e.g. CentOS 6):

wget -O FILE URL

works. But:

wget URL -O FILE

does not work.

How to create a RelativeLayout programmatically with two buttons one on top of the other?

Found the answer in How to lay out Views in RelativeLayout programmatically?

We should explicitly set id's using setId(). Only then, RIGHT_OF rules make sense.

Another mistake I did is, reusing the layoutparams object between the controls. We should create new object for each control

Redefining the Index in a Pandas DataFrame object

If you don't want 'a' in the index

In :

col = ['a','b','c']

data = DataFrame([[1,2,3],[10,11,12],[20,21,22]],columns=col)

data

Out:

    a   b   c
0   1   2   3
1  10  11  12
2  20  21  22

In :

data2 = data.set_index('a')

Out:

     b   c
a
1    2   3
10  11  12
20  21  22

In :

data2.index.name = None

Out:

     b   c
 1   2   3
10  11  12
20  21  22

Update React component every second

The following code is a modified example from React.js website.

Original code is available here: https://reactjs.org/#a-simple-component

class Timer extends React.Component {
  constructor(props) {
    super(props);
    this.state = {
      seconds: parseInt(props.startTimeInSeconds, 10) || 0
    };
  }

  tick() {
    this.setState(state => ({
      seconds: state.seconds + 1
    }));
  }

  componentDidMount() {
    this.interval = setInterval(() => this.tick(), 1000);
  }

  componentWillUnmount() {
    clearInterval(this.interval);
  }

  formatTime(secs) {
    let hours   = Math.floor(secs / 3600);
    let minutes = Math.floor(secs / 60) % 60;
    let seconds = secs % 60;
    return [hours, minutes, seconds]
        .map(v => ('' + v).padStart(2, '0'))
        .filter((v,i) => v !== '00' || i > 0)
        .join(':');
  }

  render() {
    return (
      <div>
        Timer: {this.formatTime(this.state.seconds)}
      </div>
    );
  }
}

ReactDOM.render(
  <Timer startTimeInSeconds="300" />,
  document.getElementById('timer-example')
);

Get a specific bit from byte

Try the code below. The difference with other posts is that you can set/get multiple bits using a mask (field). The mask for the 4th bit can be 1<<3, or 0x10, for example.

    public int SetBits(this int target, int field, bool value)
    {
        if (value) //set value
        {
            return target | field;
        }
        else //clear value
        {
            return target & (~field);
        }
    }

    public bool GetBits(this int target, int field)
    {
        return (target & field) > 0;
    }

** Example **

        bool is_ok = 0x01AF.GetBits(0x10); //false
        int res = 0x01AF.SetBits(0x10, true);
        is_ok = res.GetBits(0x10);  // true

how to remove only one style property with jquery

The documentation for css() says that setting the style property to the empty string will remove that property if it does not reside in a stylesheet:

Setting the value of a style property to an empty string — e.g. $('#mydiv').css('color', '') — removes that property from an element if it has already been directly applied, whether in the HTML style attribute, through jQuery's .css() method, or through direct DOM manipulation of the style property. It does not, however, remove a style that has been applied with a CSS rule in a stylesheet or <style> element.

Since your styles are inline, you can write:

$(selector).css("-moz-user-select", "");

Turn off axes in subplots

You can turn the axes off by following the advice in Veedrac's comment (linking to here) with one small modification.

Rather than using plt.axis('off') you should use ax.axis('off') where ax is a matplotlib.axes object. To do this for your code you simple need to add axarr[0,0].axis('off') and so on for each of your subplots.

The code below shows the result (I've removed the prune_matrix part because I don't have access to that function, in the future please submit fully working code.)

import matplotlib.pyplot as plt
import matplotlib.image as mpimg
import matplotlib.cm as cm

img = mpimg.imread("stewie.jpg")

f, axarr = plt.subplots(2, 2)
axarr[0,0].imshow(img, cmap = cm.Greys_r)
axarr[0,0].set_title("Rank = 512")
axarr[0,0].axis('off')

axarr[0,1].imshow(img, cmap = cm.Greys_r)
axarr[0,1].set_title("Rank = %s" % 128)
axarr[0,1].axis('off')

axarr[1,0].imshow(img, cmap = cm.Greys_r)
axarr[1,0].set_title("Rank = %s" % 32)
axarr[1,0].axis('off')

axarr[1,1].imshow(img, cmap = cm.Greys_r)
axarr[1,1].set_title("Rank = %s" % 16)
axarr[1,1].axis('off')

plt.show()

Stewie example

Note: To turn off only the x or y axis you can use set_visible() e.g.:

axarr[0,0].xaxis.set_visible(False) # Hide only x axis

Generate PDF from Swagger API documentation

You can modify your REST project, so as to produce the needed static documents (html, pdf etc) upon building the project.

If you have a Java Maven project you can use the pom snippet below. It uses a series of plugins to generate a pdf and an html documentation (of the project's REST resources).

  1. rest-api -> swagger.json : swagger-maven-plugin
  2. swagger.json -> Asciidoc : swagger2markup-maven-plugin
  3. Asciidoc -> PDF : asciidoctor-maven-plugin

Please be aware that the order of execution matters, since the output of one plugin, becomes the input to the next:

<plugin>
    <groupId>com.github.kongchen</groupId>
    <artifactId>swagger-maven-plugin</artifactId>
    <version>3.1.3</version>
    <configuration>
        <apiSources>
            <apiSource>
                <springmvc>false</springmvc>
                <locations>some.package</locations>
                <basePath>/api</basePath>
                <info>
                    <title>Put your REST service's name here</title>
                    <description>Add some description</description>
                    <version>v1</version>
                </info>
                <swaggerDirectory>${project.build.directory}/api</swaggerDirectory>
                <attachSwaggerArtifact>true</attachSwaggerArtifact>
            </apiSource>
        </apiSources>
    </configuration>
    <executions>
        <execution>
            <phase>${phase.generate-documentation}</phase>
            <!-- fx process-classes phase -->
            <goals>
                <goal>generate</goal>
            </goals>
        </execution>
    </executions>
</plugin>
<plugin>
    <groupId>io.github.robwin</groupId>
    <artifactId>swagger2markup-maven-plugin</artifactId>
    <version>0.9.3</version>
    <configuration>
        <inputDirectory>${project.build.directory}/api</inputDirectory>
        <outputDirectory>${generated.asciidoc.directory}</outputDirectory>
        <!-- specify location to place asciidoc files -->
        <markupLanguage>asciidoc</markupLanguage>
    </configuration>
    <executions>
        <execution>
            <phase>${phase.generate-documentation}</phase>
            <goals>
                <goal>process-swagger</goal>
            </goals>
        </execution>
    </executions>
</plugin>
<plugin>
    <groupId>org.asciidoctor</groupId>
    <artifactId>asciidoctor-maven-plugin</artifactId>
    <version>1.5.3</version>
    <dependencies>
        <dependency>
            <groupId>org.asciidoctor</groupId>
            <artifactId>asciidoctorj-pdf</artifactId>
            <version>1.5.0-alpha.11</version>
        </dependency>
        <dependency>
            <groupId>org.jruby</groupId>
            <artifactId>jruby-complete</artifactId>
            <version>1.7.21</version>
        </dependency>
    </dependencies>
    <configuration>
        <sourceDirectory>${asciidoctor.input.directory}</sourceDirectory>
        <!-- You will need to create an .adoc file. This is the input to this plugin -->
        <sourceDocumentName>swagger.adoc</sourceDocumentName>
        <attributes>
            <doctype>book</doctype>
            <toc>left</toc>
            <toclevels>2</toclevels>
            <generated>${generated.asciidoc.directory}</generated>
            <!-- this path is referenced in swagger.adoc file. The given file will simply 
                point to the previously create adoc files/assemble them. -->
        </attributes>
    </configuration>
    <executions>
        <execution>
            <id>asciidoc-to-html</id>
            <phase>${phase.generate-documentation}</phase>
            <goals>
                <goal>process-asciidoc</goal>
            </goals>
            <configuration>
                <backend>html5</backend>
                <outputDirectory>${generated.html.directory}</outputDirectory>
                <!-- specify location to place html file -->
            </configuration>
        </execution>
        <execution>
            <id>asciidoc-to-pdf</id>
            <phase>${phase.generate-documentation}</phase>
            <goals>
                <goal>process-asciidoc</goal>
            </goals>
            <configuration>
                <backend>pdf</backend>
                <outputDirectory>${generated.pdf.directory}</outputDirectory>
                <!-- specify location to place pdf file -->
            </configuration>
        </execution>
    </executions>
</plugin>

The asciidoctor plugin assumes the existence of an .adoc file to work on. You can create one that simply collects the ones that were created by the swagger2markup plugin:

include::{generated}/overview.adoc[]
include::{generated}/paths.adoc[]
include::{generated}/definitions.adoc[]

If you want your generated html document to become part of your war file you have to make sure that it is present on the top level - static files in the WEB-INF folder will not be served. You can do this in the maven-war-plugin:

<plugin>
    <artifactId>maven-war-plugin</artifactId>
    <configuration>
        <warSourceDirectory>WebContent</warSourceDirectory>
        <failOnMissingWebXml>false</failOnMissingWebXml>
        <webResources>
            <resource>
                <directory>${generated.html.directory}</directory>
            <!-- Add swagger.pdf to WAR file, so as to make it available as static content. -->
            </resource>
            <resource>
                <directory>${generated.pdf.directory}</directory>
            <!-- Add swagger.html to WAR file, so as to make it available as static content. -->
            </resource>
        </webResources>
    </configuration>
</plugin>

The war plugin works on the generated documentation - as such, you must make sure that those plugins have been executed in an earlier phase.

How do I access refs of a child component in the parent component

Here is an example that will focus on an input using refs (tested in React 16.8.6):

The Child component:

class Child extends React.Component {
  constructor(props) {
    super(props);
    this.myRef = React.createRef();
  }
  render() {
    return (<input type="text" ref={this.myRef} />);
  }
}

The Parent component with the Child component inside:

class Parent extends React.Component {
  constructor(props) {
    super(props);
    this.childRef = React.createRef();
  }
  componentDidMount() {
    this.childRef.current.myRef.current.focus();
  }
  render() {
    return <Child ref={this.childRef} />;
  }
}

ReactDOM.render(
    <Parent />,
    document.getElementById('container')
);

The Parent component with this.props.children:

class Parent extends React.Component {
    constructor(props) {
        super(props);
        this.childRef = React.createRef();
    }
    componentDidMount() {
        this.childRef.current.myRef.current.focus();
    }
    render() {
        const ChildComponentWithRef = React.forwardRef((props, ref) =>
            React.cloneElement(this.props.children, {
                ...props,
                ref
            })
        );
        return <ChildComponentWithRef ref={this.childRef} />
    }
}

ReactDOM.render(
    <Parent>
        <Child />
    </Parent>,
    document.getElementById('container')
);

Center text in div?

display: block;
text-align: center;

Delete sql rows where IDs do not have a match from another table

DELETE FROM blob 
WHERE fileid NOT IN 
       (SELECT id 
        FROM files 
        WHERE id is NOT NULL/*This line is unlikely to be needed 
                               but using NOT IN...*/
      )

Display List in a View MVC

Your action method considers model type asList<string>. But, in your view you are waiting for IEnumerable<Standings.Models.Teams>. You can solve this problem with changing the model in your view to List<string>.

But, the best approach would be to return IEnumerable<Standings.Models.Teams> as a model from your action method. Then you haven't to change model type in your view.

But, in my opinion your models are not correctly implemented. I suggest you to change it as:

public class Team
{
    public int Position { get; set; }
    public string HomeGround {get; set;}
    public string NickName {get; set;}
    public int Founded { get; set; }
    public string Name { get; set; }
}

Then you must change your action method as:

public ActionResult Index()
{
    var model = new List<Team>();

    model.Add(new Team { Name = "MU"});
    model.Add(new Team { Name = "Chelsea"});
    ...

    return View(model);
}

And, your view:

@model IEnumerable<Standings.Models.Team>

@{
     ViewBag.Title = "Standings";
}

@foreach (var item in Model)
{
    <div>
        @item.Name
        <hr />
    </div>
}

How can I stop "property does not exist on type JQuery" syntax errors when using Typescript?

For your example, you'd add this:

interface JQuery{
    printArea():void;
}

Edit: oops, basarat is correct below. I'm not sure why I thought it was compiling but I've updated this answer.

Set System.Drawing.Color values

You could do:

Color c = Color.FromArgb(red, green, blue); //red, green and blue are integer variables containing red, green and blue components

java: run a function after a specific number of seconds

All other unswers require to run your code inside a new thread. In some simple use cases you may just want to wait a bit and continue execution within the same thread/flow.

Code below demonstrates that technique. Keep in mind this is similar to what java.util.Timer does under the hood but more lightweight.

import java.util.concurrent.TimeUnit;
public class DelaySample {
    public static void main(String[] args) {
       DelayUtil d = new DelayUtil();
       System.out.println("started:"+ new Date());
       d.delay(500);
       System.out.println("half second after:"+ new Date());
       d.delay(1, TimeUnit.MINUTES); 
       System.out.println("1 minute after:"+ new Date());
    }
}

DelayUtil Implementation

import java.util.concurrent.TimeUnit;
import java.util.concurrent.locks.Condition;
import java.util.concurrent.locks.ReentrantLock;

public class DelayUtil {
    /** 
    *  Delays the current thread execution. 
    *  The thread loses ownership of any monitors. 
    *  Quits immediately if the thread is interrupted
    *  
    * @param duration the time duration in milliseconds
    */
   public void delay(final long durationInMillis) {
      delay(durationInMillis, TimeUnit.MILLISECONDS);
   }

   /** 
    * @param duration the time duration in the given {@code sourceUnit}
    * @param unit
    */
    public void delay(final long duration, final TimeUnit unit) {
        long currentTime = System.currentTimeMillis();
        long deadline = currentTime+unit.toMillis(duration);
        ReentrantLock lock = new ReentrantLock();
        Condition waitCondition = lock.newCondition();

        while ((deadline-currentTime)>0) {
            try {
                lock.lockInterruptibly();    
                waitCondition.await(deadline-currentTime, TimeUnit.MILLISECONDS);
            } catch (InterruptedException e) {
                Thread.currentThread().interrupt();
                return;
            } finally {
                lock.unlock();
            }
            currentTime = System.currentTimeMillis();
        }
    }
}

how to reset <input type = "file">

<input type="file" id="mfile" name="mfile">
<p>Reset</p>

<script>
$(document).ready(function(){
$("p").click(function(){

            $("#mfile").val('');
            return false;

    });
});

GitHub Error Message - Permission denied (publickey)

this worked for me:

1- remove all origins

git remote rm origin  

(cf. https://www.kernel.org/pub/software/scm/git/docs/git-remote.html)

*remote : "Manage the set of repositories ("remotes") whose branches you track.

*rm : "Remove the remote named . All remote-tracking branches and configuration settings for the remote are removed."

2- check all has been removed :

git remote -v  

3- add new origin master

git remote add origin [email protected]:YOUR-GIT/YOUR-REPO.git

that's all folks!

How to find serial number of Android device?

Starting in Android 10, apps must have the READ_PRIVILEGED_PHONE_STATE privileged permission in order to access the device's non-resettable identifiers, which include both IMEI and serial number.

Affected methods include the following:

Build getSerial() TelephonyManager getImei() getDeviceId() getMeid() getSimSerialNumber() getSubscriberId()

READ_PRIVILEGED_PHONE_STATE is available for platform only

Force flex item to span full row width

When you want a flex item to occupy an entire row, set it to width: 100% or flex-basis: 100%, and enable wrap on the container.

The item now consumes all available space. Siblings are forced on to other rows.

_x000D_
_x000D_
.parent {
  display: flex;
  flex-wrap: wrap;
}

#range, #text {
  flex: 1;
}

.error {
  flex: 0 0 100%; /* flex-grow, flex-shrink, flex-basis */
  border: 1px dashed black;
}
_x000D_
<div class="parent">
  <input type="range" id="range">
  <input type="text" id="text">
  <label class="error">Error message (takes full width)</label>
</div>
_x000D_
_x000D_
_x000D_

More info: The initial value of the flex-wrap property is nowrap, which means that all items will line up in a row. MDN

GCC: array type has incomplete element type

The compiler needs to know the size of the second dimension in your two dimensional array. For example:

void print_graph(g_node graph_node[], double weight[][5], int nodes);

Getting the current date in visual Basic 2008

Try this:

Dim regDate as Date = Date.Now()
Dim strDate as String = regDate.ToString("ddMMMyyyy")

strDate will look like so: 07Feb2012

Better way to get type of a Javascript variable?

I guess the most universal solution here - is to check for undefined and null first, then just call constructor.name.toLowerCase().

const getType = v =>
  v === undefined
    ? 'undefined'
    : v === null
      ? 'null'
      : v.constructor.name.toLowerCase();




console.log(getType(undefined)); // 'undefined'
console.log(getType(null)); // 'null'
console.log(getType('')); // 'string'
console.log(getType([])); // 'array'
console.log(getType({})); // 'object'
console.log(getType(new Set())); // `set'
console.log(getType(Promise.resolve())); // `promise'
console.log(getType(new Map())); // `map'

Windows 8.1 gets Error 720 on connect VPN

First I would like to thank Rose who was willing to help us, but your answer could solve the problem on a computer, but in others there was what was done could not always connect gets error 720. After much searching and contact the Microsoft support we can solve. In Device Manager, on the View menu, select to show hidden devices. Made it look for a remote Miniport IP or network monitor that is with warning of problems with the driver icon. In its properties in the details tab check the Key property of the driver. Look for this key in Regedit on Local Machine, make a backup of that key and delete it. Restart your windows. Reopen your device manager and select the miniport that had deleted the record. Activate the option to update the driver and look for the option driver on the computer manually and then use the option to locate the driver from the list available on the computer on the next screen uncheck show compatible hardware. Then you must select the Microsoft Vendor and the driver WAN Miniport the type that is changing, IP or IPV6 L2TP Network Monitor. After upgrading restart the computer.

I know it's a bit laborious but that was the only way that worked on all computers.

android EditText - finished typing event

I ended her with the same problem and I could not use the the solution with onEditorAction or onFocusChange and did not want to try the timer. A timer is too dangerous for may taste, because of all the threads and too unpredictable, as you do not know when you code is executed.

The onEditorAction do not catch when the user leave without using a button and if you use it please notice that KeyEvent can be null. The focus is unreliable at both ends the user can get focus and leave without enter any text or selecting the field and the user do not need to leave the last EditText field.

My solution use onFocusChange and a flag set when the user starts editing text and a function to get the text from the last focused view, which I call when need.

I just clear the focus on all my text fields to tricker the leave text view code, The clearFocus code is only executed if the field has focus. I call the function in onSaveInstanceState so I do not have to save the flag (mEditing) as a state of the EditText view and when important buttons is clicked and when the activity is closed.

Be careful with TexWatcher as it is call often I use the condition on focus to not react when the onRestoreInstanceState code entering text. I

final EditText mEditTextView = (EditText) getView();

    mEditTextView.addTextChangedListener(new TextWatcher() {
        @Override
        public void beforeTextChanged(CharSequence s, int start, int count, int after) {

        }

        @Override
        public void onTextChanged(CharSequence s, int start, int before, int count) {

        }

        @Override
        public void afterTextChanged(Editable s) {
            if (!mEditing && mEditTextView.hasFocus()) {
                mEditing = true;
            }
        }
    });
    mEditTextView.setOnFocusChangeListener(new View.OnFocusChangeListener() {

        @Override
        public void onFocusChange(View v, boolean hasFocus) {
            if (!hasFocus && mEditing) {
                mEditing = false;
                ///Do the thing
            }
        }
    });
protected void saveLastOpenField(){
    for (EditText view:getFields()){
            view.clearFocus();
    }
}

CSS: Hover one element, effect for multiple elements?

OR

.section:hover > div {
  background-color: #0CF;
}

NOTE Parent element state can only affect a child's element state so you can use:

.image:hover + .layer {
  background-color: #0CF;
}
.image:hover {
  background-color: #0CF;
}

but you can not use

.layer:hover + .image {
  background-color: #0CF;
}

How do I time a method's execution in Java?

Just a small twist, if you don't use tooling and want to time methods with low execution time: execute it many times, each time doubling the number of times it is executed until you reach a second, or so. Thus, the time of the Call to System.nanoTime and so forth, nor the accuracy of System.nanoTime does affect the result much.

    int runs = 0, runsPerRound = 10;
    long begin = System.nanoTime(), end;
    do {
        for (int i=0; i<runsPerRound; ++i) timedMethod();
        end = System.nanoTime();
        runs += runsPerRound;
        runsPerRound *= 2;
    } while (runs < Integer.MAX_VALUE / 2 && 1000000000L > end - begin);
    System.out.println("Time for timedMethod() is " + 
        0.000000001 * (end-begin) / runs + " seconds");

Of course, the caveats about using the wall clock apply: influences of JIT-compilation, multiple threads / processes etc. Thus, you need to first execute the method a lot of times first, such that the JIT compiler does its work, and then repeat this test multiple times and take the lowest execution time.

Node.js Error: Cannot find module express

Run npm install express body-parser cookie-parser multer --save command in the same directory with your source code nodejs file to resolve this issue. P/s: check your directory after run command to understand more!

CSS/HTML: Create a glowing border around an Input Field

Below is the code that Bootstrap uses. Colors are bit different but the concept is same. This is if you are using LESS to compile CSS:

// Form control focus state
//
// Generate a customized focus state and for any input with the specified color,
// which defaults to the `@input-focus-border` variable.
//
// We highly encourage you to not customize the default value, but instead use
// this to tweak colors on an as-needed basis. This aesthetic change is based on
// WebKit's default styles, but applicable to a wider range of browsers. Its
// usability and accessibility should be taken into account with any change.
//
// Example usage: change the default blue border and shadow to white for better
// contrast against a dark gray background.

.form-control-focus(@color: @input-border-focus) {
  @color-rgba: rgba(red(@color), green(@color), blue(@color), .6);
  &:focus {
    border-color: @color;
    outline: 0;
    .box-shadow(~"inset 0 1px 1px rgba(0,0,0,.075), 0 0 8px @{color-rgba}");
  }
}

If you are not using LESS then here's the compiled version:

.form-control:focus {
    border-color: #66afe9;
    outline: 0;
    -webkit-box-shadow: inset 0 1px 1px rgba(0, 0, 0, 0.075), 0 0 8px rgba(102, 175, 233, 0.6);
    box-shadow: inset 0 1px 1px rgba(0, 0, 0, 0.075), 0 0 8px rgba(102, 175, 233, 0.6);
}

How to replace � in a string

Change the Encoding to UTF-8 while parsing .This will remove the special characters

jQuery override default validation error message display (Css) Popup/Tooltip like

If you could provide some reason as to why you need to replace the label with a div, that would certainly help...

Also, could you paste a sample that'd be helpful ( http://dpaste.com/ or http://pastebin.com/)

How to show Bootstrap table with sort icon

BOOTSTRAP 4

you can use a combination of

  • fa-chevron-down, fa-chevron-up

  • fa-sort-down, fa-sort-up

<th class="text-center">
    <div class="btn-group" role="group">
        <button type="button" class="btn btn-xs btn-link py-0 pl-0 pr-1">
             Some Text OR icon
        </button>
        <div class="btn-group-vertical">
            <a href="?sort=asc" class="btn btn-xs btn-link p-0">
                <i class="fas fa-sort-up"></i>
            </a>
            <a href="?sort=desc" class="btn btn-xs btn-link p-0">
                <i class="fas fa-sort-down"></i>
            </a>
        </div>
    </div>
</th>

How to post data in PHP using file_get_contents?

An alternative, you can also use fopen

$params = array('http' => array(
    'method' => 'POST',
    'content' => 'toto=1&tata=2'
));

$ctx = stream_context_create($params);
$fp = @fopen($sUrl, 'rb', false, $ctx);
if (!$fp)
{
    throw new Exception("Problem with $sUrl, $php_errormsg");
}

$response = @stream_get_contents($fp);
if ($response === false) 
{
    throw new Exception("Problem reading data from $sUrl, $php_errormsg");
}

php artisan migrate throwing [PDO Exception] Could not find driver - Using Laravel

You must be installing the latest version of php mysql in my case I am install php7.1-mysql

Try this

sudo apt-get install php7.1-mysql

I am using the latest version of laravel

XML Schema Validation : Cannot find the declaration of element

The targetNamespace of your XML Schema does not match the namespace of the Root element (dot in Test.Namespace vs. comma in Test,Namespace)

Once you make the above agree, you have to consider that your element2 has an attribute order that is not in your XSD.

Move seaborn plot legend to a different position?

This is how I was able to move the legend to a particular place inside the plot and change the aspect and size of the plot:

import matplotlib
matplotlib.use('Agg')
import matplotlib.pyplot as plt
matplotlib.style.use('ggplot')
import seaborn as sns
sns.set(style="ticks")

figure_name = 'rater_violinplot.png'
figure_output_path = output_path + figure_name

viol_plot = sns.factorplot(x="Rater", 
                       y="Confidence", 
                       hue="Event Type", 
                       data=combo_df, 
                       palette="colorblind",
                       kind='violin',
                       size = 10,
                       aspect = 1.5,
                       legend=False)

viol_plot.ax.legend(loc=2)
viol_plot.fig.savefig(figure_output_path)  

Legend location changed

This worked for me to change the size and aspect of the plot as well as move the legend outside the plot area.

import matplotlib
matplotlib.use('Agg')
import matplotlib.pyplot as plt
matplotlib.style.use('ggplot')
import seaborn as sns
sns.set(style="ticks")


figure_name = 'rater_violinplot.png'
figure_output_path = output_path + figure_name

viol_plot = sns.factorplot(x="Rater", 
                       y="Confidence", 
                       hue="Event Type", 
                       data=combo_df, 
                       palette="colorblind",
                       kind='violin',
                       size = 10,
                       aspect = 1.5,
                       legend_out=True)

viol_plot.fig.savefig(figure_output_path)  

violin plot with changed size, aspect and legend located outside

I figured this out from mwaskom's answer here and Fernando Hernandez's answer here.

How to sort mongodb with pymongo

.sort(), in pymongo, takes key and direction as parameters.

So if you want to sort by, let's say, id then you should .sort("_id", 1)

For multiple fields:

.sort([("field1", pymongo.ASCENDING), ("field2", pymongo.DESCENDING)])

How to disable Django's CSRF validation?

To disable CSRF for class based views the following worked for me.
Using django 1.10 and python 3.5.2

from django.views.decorators.csrf import csrf_exempt
from django.utils.decorators import method_decorator

@method_decorator(csrf_exempt, name='dispatch')
class TestView(View):
    def post(self, request, *args, **kwargs):
        return HttpResponse('Hello world')

Correlation between two vectors?

Try xcorr, it's a built-in function in MATLAB for cross-correlation:

c = xcorr(A_1, A_2);

However, note that it requires the Signal Processing Toolbox installed. If not, you can look into the corrcoef command instead.

How to change date format using jQuery?

You don't need any date-specific functions for this, it's just string manipulation:

var parts = fecha2.value.split('-');
var newdate = parts[1]+'-'+parts[2]+'-'+(parseInt(parts[0], 10)%100);

How can I scale an entire web page with CSS?

CSS will not be able to zoom on demand, but if you couple CSS with JS, you could change some values to make a page look bigger. However, as it has been said, this feature is standard nowadays in modern browsers: no need to replicate it. As a matter of fact, replicating it will slow down your website (more things to load, more JS or CSS to parse or execute and apply, etc.)

How do I prevent Eclipse from hanging on startup?

This one works for me:

Another, and a bit better workaround which apparently works:

  1. Close Eclipse.
  2. Temporary move offending project somewhere out of the workspace.
  3. Start Eclipse, wait for workspace to load (it should).
  4. Close Eclipse again.
  5. Move the project back to workspace.

Source: Eclipse hangs while opening workspace after upgrading to GWT 2.0/Google app engine 1.2.8

Interface/enum listing standard mime-type constants

There is now also the class org.apache.http.entity.ContentType from package org.apache.httpcomponents.httpcore, starting from 4.2 up.

Remove all padding and margin table HTML and CSS

Use a display block

style= "display: block";

How to convert a Date to a formatted string in VB.net?

Dim timeFormat As String = "yyyy-MM-dd HH:mm:ss"
objBL.date = Convert.ToDateTime(txtDate.Value).ToString(timeFormat)

Adding a custom header to HTTP request using angular.js

I took what you had, and added another X-Testing header

var config = {headers:  {
        'Authorization': 'Basic d2VudHdvcnRobWFuOkNoYW5nZV9tZQ==',
        'Accept': 'application/json;odata=verbose',
        "X-Testing" : "testing"
    }
};

$http.get("/test", config);

And in the Chrome network tab, I see them being sent.

GET /test HTTP/1.1
Host: localhost:3000
Connection: keep-alive
Accept: application/json;odata=verbose
X-Requested-With: XMLHttpRequest
User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_8_3) AppleWebKit/537.22 (KHTML, like Gecko) Chrome/25.0.1364.172 Safari/537.22
Authorization: Basic d2VudHdvcnRobWFuOkNoYW5nZV9tZQ==
X-Testing: testing
Referer: http://localhost:3000/
Accept-Encoding: gzip,deflate,sdch
Accept-Language: en-US,en;q=0.8
Accept-Charset: ISO-8859-1,utf-8;q=0.7,*;q=0.3

Are you not seeing them from the browser, or on the server? Try the browser tooling or a debug proxy and see what is being sent out.

Showing all errors and warnings

You can see a detailed description here.

ini_set('display_errors', 1);

// Report simple running errors
error_reporting(E_ERROR | E_WARNING | E_PARSE);

// Reporting E_NOTICE can be good too (to report uninitialized
// variables or catch variable name misspellings ...)
error_reporting(E_ERROR | E_WARNING | E_PARSE | E_NOTICE);

// Report all errors except E_NOTICE
error_reporting(E_ALL & ~E_NOTICE);

// Report all PHP errors (see changelog)
error_reporting(E_ALL);

// Report all PHP errors
error_reporting(-1);

// Same as error_reporting(E_ALL);
ini_set('error_reporting', E_ALL);

Changelog

  • 5.4.0 E_STRICT became part of E_ALL

  • 5.3.0 E_DEPRECATED and E_USER_DEPRECATED introduced.

  • 5.2.0 E_RECOVERABLE_ERROR introduced.

  • 5.0.0 E_STRICT introduced (not part of E_ALL).

How to detect incoming calls, in an Android device?

Just to update Gabe Sechan's answer. If your manifest asks for permissions to READ_CALL_LOG and READ_PHONE_STATE, onReceive will called TWICE. One of which has EXTRA_INCOMING_NUMBER in it and the other doesn't. You have to test which has it and it can occur in any order.

https://developer.android.com/reference/android/telephony/TelephonyManager.html#ACTION_PHONE_STATE_CHANGED

MongoDB logging all queries

I recommend checking out mongosniff. This can tool can do everything you want and more. Especially it can help diagnose issues with larger scale mongo systems and how queries are being routed and where they are coming from since it works by listening to your network interface for all mongo related communications.

http://docs.mongodb.org/v2.2/reference/mongosniff/

maven-dependency-plugin (goals "copy-dependencies", "unpack") is not supported by m2e

This is a problem of M2E for Eclipse M2E plugin execution not covered.

To solve this problem, all you got to do is to map the lifecycle it doesn't recognize and instruct M2E to execute it.

You should add this after your plugins, inside the build. This will remove the error and make M2E recognize the goal copy-depencies of maven-dependency-plugin and make the POM work as expected, copying dependencies to folder every time Eclipse build it. If you just want to ignore the error, then you change <execute /> for <ignore />. No need for enclosing your maven-dependency-plugin into pluginManagement, as suggested before.

<pluginManagement>
  <plugins>
    <plugin>
      <groupId>org.eclipse.m2e</groupId>
      <artifactId>lifecycle-mapping</artifactId>
      <version>1.0.0</version>
      <configuration>
        <lifecycleMappingMetadata>
          <pluginExecutions>
            <pluginExecution>
              <pluginExecutionFilter>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-dependency-plugin</artifactId>
                <versionRange>[2.0,)</versionRange>
                <goals>
                  <goal>copy-dependencies</goal>
                </goals>
              </pluginExecutionFilter>
              <action>
                <execute />
              </action>
            </pluginExecution>
          </pluginExecutions>
        </lifecycleMappingMetadata>
      </configuration>
    </plugin>
  </plugins>
</pluginManagement>

What are carriage return, linefeed, and form feed?

In Short :

Carriage_return(\r or 0xD): To take control at starting of same line.

Line_Feed(\n or 0xA): To Take control at starting of next line.

form_feed(\f or 0xC): To take control at starting of next page.

Arrays.asList() of an array

As far as I understand it, the sort function in the collection class can only be used to sort collections implementing the comparable interface.

You are supplying it a array of integers. You should probably wrap this around one of the know Wrapper classes such as Integer. Integer implements comparable.

Its been a long time since I have worked on some serious Java, however reading some matter on the sort function will help.

What is the difference between Bower and npm?

For many people working with node.js, a major benefit of bower is for managing dependencies that are not javascript at all. If they are working with languages that compile to javascript, npm can be used to manage some of their dependencies. however, not all their dependencies are going to be node.js modules. Some of those that compile to javascript may have weird source language specific mangling that makes passing them around compiled to javascript an inelegant option when users are expecting source code.

Not everything in an npm package needs to be user-facing javascript, but for npm library packages, at least some of it should be.

How to draw a filled circle in Java?

public void paintComponent(Graphics g) {
   super.paintComponent(g);
   Graphics2D g2d = (Graphics2D)g;
   // Assume x, y, and diameter are instance variables.
   Ellipse2D.Double circle = new Ellipse2D.Double(x, y, diameter, diameter);
   g2d.fill(circle);
   ...
}

Here are some docs about paintComponent (link).

You should override that method in your JPanel and do something similar to the code snippet above.

In your ActionListener you should specify x, y, diameter and call repaint().

Adding dictionaries together, Python

You are looking for the update method

dic0.update( dic1 )
print( dic0 ) 

gives

{'dic0': 0, 'dic1': 1}

Why use 'git rm' to remove a file instead of 'rm'?

Remove files from the index, or from the working tree and the index. git rm will not remove a file from just your working directory.

Here's how you might delete a file using rm -f and then remove it from your index with git rm

$ rm -f index.html
$ git status -s
 D index.html
$ git rm index.html
rm 'index.html'
$ git status -s
D  index.html

However you can do this all in one go with just git rm

$ git status -s
$ git rm index.html
rm 'index.html'
$ ls
lib vendor
$ git status -s
D  index.html

How can I make a ComboBox non-editable in .NET?

To continue displaying data in the input after selecting, do so:

VB.NET
Private Sub ComboBox1_KeyPress(ByVal sender As Object, ByVal e As System.Windows.Forms.KeyPressEventArgs) Handles ComboBox1.KeyPress
    e.Handled = True
End Sub



C#
Private void ComboBox1_KeyPress(object sender, KeyPressEventArgs e)
{
    e.Handled = true;
}

How to validate a form with multiple checkboxes to have atleast one checked

How about this:

$(document).ready(function() {
    $('#subscribeForm').submit(function() {
        var $fields = $(this).find('input[name="list"]:checked');
        if (!$fields.length) {
            alert('You must check at least one box!');
            return false; // The form will *not* submit
        }
    });
});

laravel Eloquent ORM delete() method

$model=User::where('id',$id)->delete();

How to undo a SQL Server UPDATE query?

A non-committed transaction can be reverted by issuing the command ROLLBACK

But if you are running in auto-commit mode there is nothing you can do....

Javascript - Get Image height

It's worth noting that in Firefox 3 and Safari, resizing an image by just changing the height and width doesn't look too bad. In other browsers it can look very noisy because it's using nearest-neighbor resampling. Of course, you're paying to serve a larger image, but that might not matter.

When to favor ng-if vs. ng-show/ng-hide?

From my experience:

1) If your page has a toggle that uses ng-if/ng-show to show/hide something, ng-if causes more of a browser delay (slower). For example: if you have a button used to toggle between two views, ng-show seems to be faster.

2) ng-if will create/destroy scope when it evaluates to true/false. If you have a controller attached to the ng-if, that controller code will get executed every time the ng-if evaluates to true. If you are using ng-show, the controller code only gets executed once. So if you have a button that toggles between multiple views, using ng-if and ng-show would make a huge difference in how you write your controller code.

Tri-state Check box in HTML?

There's a simple JavaScript tri-state input field implementation at https://github.com/supernifty/tristate-checkbox

The type arguments for method cannot be inferred from the usage

I received this error because I had made a mistake in the definition of my method. I had declared the method to accept a generic type (notice the "T" after the method name):

protected int InsertRecord<T>(CoasterModel model, IDbConnection con)

However, when I called the method, I did not use the type which, in my case, was the correct usage:

int count = InsertRecord(databaseToMigrateFrom, con);

I just removed the generic casting and it worked.

How to make gradient background in android

First you need to create a gradient.xml as follows

<shape>
    <gradient android:angle="270" android:endColor="#181818" android:startColor="#616161" />

    <stroke android:width="1dp" android:color="#343434" />
</shape>

Then you need to mention above gradient in the background of layout.As follows

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

Angular - res.json() is not a function

Had a similar problem where we wanted to update from deprecated Http module to HttpClient in Angular 7. But the application is large and need to change res.json() in a lot of places. So I did this to have the new module with back support.

return this.http.get(this.BASE_URL + url)
      .toPromise()
      .then(data=>{
        let res = {'results': JSON.stringify(data),
        'json': ()=>{return data;}
      };
       return res; 
      })
      .catch(error => {
        return Promise.reject(error);
      });

Adding a dummy "json" named function from the central place so that all other services can still execute successfully before updating them to accommodate a new way of response handling i.e. without "json" function.

Should I use past or present tense in git commit messages?

Who are you writing the message for? And is that reader typically reading the message pre- or post- ownership the commit themselves?

I think good answers here have been given from both perspectives, I’d perhaps just fall short of suggesting there is a best answer for every project. The split vote might suggest as much.

i.e. to summarise:

  • Is the message predominantly for other people, typically reading at some point before they have assumed the change: A proposal of what taking the change will do to their existing code.

  • Is the message predominantly as a journal/record to yourself (or to your team), but typically reading from the perspective of having assumed the change and searching back to discover what happened.

Perhaps this will lead the motivation for your team/project, either way.

How to use SqlClient in ASP.NET Core?

Try this one Open your projectname.csproj file its work for me.

<PackageReference Include="System.Data.SqlClient" Version="4.6.0" />

You need to add this Reference "ItemGroup" tag inside.

XML Carriage return encoding

A browser isn't going to show you white space reliably. I recommend the Linux 'od' command to see what's really in there. Comforming XML parsers will respect all of the methods you listed.

Changing Node.js listening port

you can get the nodejs configuration from http://nodejs.org/
The important thing you need to keep in your mind is about its configuration in file app.js which consists of port number host and other settings these are settings working for me

backendSettings = {
"scheme":"https / http ",
"host":"Your website url",
"port":49165, //port number 
'sslKeyPath': 'Path for key',
'sslCertPath': 'path for SSL certificate',
'sslCAPath': '',
"resource":"/socket.io",
"baseAuthPath": '/nodejs/',
"publishUrl":"publish",
"serviceKey":"",
"backend":{
"port":443,
"scheme": 'https / http', //whatever is your website scheme
"host":"host name",
"messagePath":"/nodejs/message/"},
"clientsCanWriteToChannels":false,
"clientsCanWriteToClients":false,
"extensions":"",
"debug":false,
"addUserToChannelUrl": 'user/channel/add/:channel/:uid',
"publishMessageToContentChannelUrl": 'content/token/message',
"transports":["websocket",
"flashsocket",
"htmlfile",
"xhr-polling",
"jsonp-polling"],
"jsMinification":true,
"jsEtag":true,
"logLevel":1};

In this if you are getting "Error: listen EADDRINUSE" then please change the port number i.e, here I am using "49165" so you can use other port such as 49170 or some other port. For this you can refer to the following article
http://www.a2hosting.com/kb/installable-applications/manual-installations/installing-node-js-on-shared-hosting-accounts

How can I symlink a file in Linux?

To create a new symlink (will fail if symlink exists already):

ln -s /path/to/file /path/to/symlink

To create or update a symlink:

ln -sf /path/to/file /path/to/symlink

Why ModelState.IsValid always return false in mvc

"ModelState.IsValid" tells you that the model is consumed by the view (i.e. PaymentAdviceEntity) is satisfy all types of validation or not specified in the model properties by DataAnotation.

In this code the view does not bind any model properties. So if you put any DataAnotations or validation in model (i.e. PaymentAdviceEntity). then the validations are not satisfy. say if any properties in model is Name which makes required in model.Then the value of the property remains blank after post.So the model is not valid (i.e. ModelState.IsValid returns false). You need to remove the model level validations.

Binding arrow keys in JS/jQuery

With coffee & Jquery

  $(document).on 'keydown', (e) ->
    switch e.which
      when 37 then console.log('left key')
      when 38 then console.log('up key')
      when 39 then console.log('right key')
      when 40 then console.log('down key')
    e.preventDefault()

Java 8 stream's .min() and .max(): why does this compile?

Apart from the information given by David M. Lloyd one could add that the mechanism that allows this is called target typing.

The idea is that the type the compiler assigns to a lambda expressions or a method references does not depend only on the expression itself, but also on where it is used.

The target of an expression is the variable to which its result is assigned or the parameter to which its result is passed.

Lambda expressions and method references are assigned a type which matches the type of their target, if such a type can be found.

See the Type Inference section in the Java Tutorial for more information.

Generate random numbers uniformly over an entire range

If you are able to, use Boost. I have had good luck with their random library.

uniform_int should do what you want.

jquery (or pure js) simulate enter key pressed for testing

For those who want to do this in pure javascript, look at:

Using standard KeyboardEvent

As Joe comment it, KeyboardEvent is now the standard.

Same example to fire an enter (keyCode 13):

const ke = new KeyboardEvent('keydown', {
    bubbles: true, cancelable: true, keyCode: 13
});
document.body.dispatchEvent(ke);

You can use this page help you to find the right keyboard event.


Outdated answer:

You can do something like (here for Firefox)

var ev = document.createEvent('KeyboardEvent');
// Send key '13' (= enter)
ev.initKeyEvent(
    'keydown', true, true, window, false, false, false, false, 13, 0);
document.body.dispatchEvent(ev);

Is it possible to decrypt SHA1

SHA1 is a one way hash. So you can not really revert it.

That's why applications use it to store the hash of the password and not the password itself.

Like every hash function SHA-1 maps a large input set (the keys) to a smaller target set (the hash values). Thus collisions can occur. This means that two values of the input set map to the same hash value.

Obviously the collision probability increases when the target set is getting smaller. But vice versa this also means that the collision probability decreases when the target set is getting larger and SHA-1's target set is 160 bit.

Jeff Preshing, wrote a very good blog about Hash Collision Probabilities that can help you to decide which hash algorithm to use. Thanks Jeff.

In his blog he shows a table that tells us the probability of collisions for a given input set.

Hash Collision Probabilities Table

As you can see the probability of a 32-bit hash is 1 in 2 if you have 77163 input values.

A simple java program will show us what his table shows:

public class Main {

    public static void main(String[] args) {
        char[] inputValue = new char[10];

        Map<Integer, String> hashValues = new HashMap<Integer, String>();

        int collisionCount = 0;

        for (int i = 0; i < 77163; i++) {
            String asString = nextValue(inputValue);
            int hashCode = asString.hashCode();
            String collisionString = hashValues.put(hashCode, asString);
            if (collisionString != null) {
                collisionCount++;
                System.out.println("Collision: " + asString + " <-> " + collisionString);
            }
        }

        System.out.println("Collision count: " + collisionCount);
    }

    private static String nextValue(char[] inputValue) {
        nextValue(inputValue, 0);

        int endIndex = 0;
        for (int i = 0; i < inputValue.length; i++) {
            if (inputValue[i] == 0) {
                endIndex = i;
                break;
            }
        }

        return new String(inputValue, 0, endIndex);
    }

    private static void nextValue(char[] inputValue, int index) {
        boolean increaseNextIndex = inputValue[index] == 'z';

        if (inputValue[index] == 0 || increaseNextIndex) {
            inputValue[index] = 'A';
        } else {
            inputValue[index] += 1;
        }

        if (increaseNextIndex) {
            nextValue(inputValue, index + 1);
        }

    }

}

My output end with:

Collision: RvV <-> SWV
Collision: SvV <-> TWV
Collision: TvV <-> UWV
Collision: UvV <-> VWV
Collision: VvV <-> WWV
Collision: WvV <-> XWV
Collision count: 35135

It produced 35135 collsions and that's the nearly the half of 77163. And if I ran the program with 30084 input values the collision count is 13606. This is not exactly 1 in 10, but it is only a probability and the example program is not perfect, because it only uses the ascii chars between A and z.

Let's take the last reported collision and check

System.out.println("VvV".hashCode());
System.out.println("WWV".hashCode());

My output is

86390
86390

Conclusion:

If you have a SHA-1 value and you want to get the input value back you can try a brute force attack. This means that you have to generate all possible input values, hash them and compare them with the SHA-1 you have. But that will consume a lot of time and computing power. Some people created so called rainbow tables for some input sets. But these do only exist for some small input sets.

And remember that many input values map to a single target hash value. So even if you would know all mappings (which is impossible, because the input set is unbounded) you still can't say which input value it was.

How to get Bitmap from an Uri?

Use startActivityForResult metod like below

        startActivityForResult(new Intent(Intent.ACTION_PICK).setType("image/*"), PICK_IMAGE);

And you can get result like this:

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
    if (resultCode != RESULT_OK) {
        return;
    }
    switch (requestCode) {
        case PICK_IMAGE:
            Uri imageUri = data.getData();
            try {
                Bitmap bitmap = MediaStore.Images.Media.getBitmap(this.getContentResolver(), imageUri);
            } catch (IOException e) {
                e.printStackTrace();
            }
         break;
    }
}

Is it possible to output a SELECT statement from a PL/SQL block?

It depends on what you need the result for.

If you are sure that there's going to be only 1 row, use implicit cursor:

DECLARE
   v_foo foobar.foo%TYPE;
   v_bar foobar.bar%TYPE;
BEGIN
   SELECT foo,bar FROM foobar INTO v_foo, v_bar;
   -- Print the foo and bar values
   dbms_output.put_line('foo=' || v_foo || ', bar=' || v_bar);
EXCEPTION
   WHEN NO_DATA_FOUND THEN
     -- No rows selected, insert your exception handler here
   WHEN TOO_MANY_ROWS THEN
     -- More than 1 row seleced, insert your exception handler here
END;

If you want to select more than 1 row, you can use either an explicit cursor:

DECLARE
   CURSOR cur_foobar IS
     SELECT foo, bar FROM foobar;

   v_foo foobar.foo%TYPE;
   v_bar foobar.bar%TYPE;
BEGIN
   -- Open the cursor and loop through the records
   OPEN cur_foobar;
   LOOP
      FETCH cur_foobar INTO v_foo, v_bar;
      EXIT WHEN cur_foobar%NOTFOUND;
      -- Print the foo and bar values
      dbms_output.put_line('foo=' || v_foo || ', bar=' || v_bar);
   END LOOP;
   CLOSE cur_foobar;
END;

or use another type of cursor:

BEGIN
   -- Open the cursor and loop through the records
   FOR v_rec IN (SELECT foo, bar FROM foobar) LOOP       
   -- Print the foo and bar values
   dbms_output.put_line('foo=' || v_rec.foo || ', bar=' || v_rec.bar);
   END LOOP;
END;

PYODBC--Data source name not found and no default driver specified

Create a DSN something like this (ASEDEV) for your connection and try to use DSN instead of DRIVER like below:

enter code here
import pyodbc
cnxn = pyodbc.connect('DSN=ASEDEV;User ID=sa;Password=sybase123')
mycur = cnxn.cursor()
mycur.execute("select * from master..sysdatabases")
row = mycur.fetchone()
while row:
    print(row)
    row = mycur.fetchone()`

How to reference a .css file on a razor view?

You can this structure in Layout.cshtml file

<link href="~/YourCssFolder/YourCssStyle.css" rel="stylesheet" type="text/css" />

Display all dataframe columns in a Jupyter Python Notebook

Python 3.x for large (but not too large) DataFrames

Maybe because I have an older version of pandas but on Jupyter notebook this work for me

import pandas as pd
from IPython.core.display import HTML

df=pd.read_pickle('Data1')
display(HTML(df.to_html()))

How to get selected value from Dropdown list in JavaScript

Direct value should work just fine:

var sv = sel.value;
alert(sv);

The only reason your code might fail is when there is no item selected, then the selectedIndex returns -1 and the code breaks.

Spark - SELECT WHERE or filtering?

According to spark documentation "where() is an alias for filter()"

filter(condition) Filters rows using the given condition. where() is an alias for filter().

Parameters: condition – a Column of types.BooleanType or a string of SQL expression.

>>> df.filter(df.age > 3).collect()
[Row(age=5, name=u'Bob')]
>>> df.where(df.age == 2).collect()
[Row(age=2, name=u'Alice')]

>>> df.filter("age > 3").collect()
[Row(age=5, name=u'Bob')]
>>> df.where("age = 2").collect()
[Row(age=2, name=u'Alice')]

Android Studio 3.0 Execution failed for task: unable to merge dex

For Cordova based project, run cordova clean android before build again, as @mkimmet suggested.

How to parse this string in Java?

public class Test {
    public static void main(String args[]) {
    String s = "pre/fix/dir1/dir2/dir3/dir4/..";
    String prefix = "pre/fix";
    String[] tokens = s.substring(prefix.length()).split("/");
    for (int i=0; i<tokens.length; i++) {
        System.out.println(tokens[i]);
    }
    }

}

The way to check a HDFS directory's size?

hadoop fs -du -s -h /path/to/dir displays a directory's size in readable form.

Bypass popup blocker on window.open when JQuery event.preventDefault() is set

I am using this method to avoid the popup blocker in my React code. it will work in all other javascript codes also.

When you are making an async call on click event, just open a blank window first and then write the URL in that later when an async call will complete.

const popupWindow = window.open("", "_blank");
popupWindow.document.write("<div>Loading, Plesae wait...</div>")

on async call's success, write the following

popupWindow.document.write(resonse.url)

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/

Programmatically read from STDIN or input file in Perl

You need to use <> operator:

while (<>) {
    print $_; # or simply "print;"
}

Which can be compacted to:

print while (<>);

Arbitrary file:

open F, "<file.txt" or die $!;
while (<F>) {
    print $_;
}
close F;

How to scroll up or down the page to an anchor using jQuery?

SS Slow Scroll

This solution does not require anchor tags but you do of course need to match the menu button (arbitrary attribute, 'ss' in example) with the destination element id in your html.

ss="about" takes you to id="about"

_x000D_
_x000D_
$('.menu-item').click(function() {_x000D_
 var keyword = $(this).attr('ss');_x000D_
 var scrollTo = $('#' + keyword);_x000D_
 $('html, body').animate({_x000D_
  scrollTop: scrollTo.offset().top_x000D_
 }, 'slow');_x000D_
});
_x000D_
.menu-wrapper {_x000D_
  display: flex;_x000D_
  margin-bottom: 500px;_x000D_
}_x000D_
.menu-item {_x000D_
  display: flex;_x000D_
  justify-content: center;_x000D_
  flex: 1;_x000D_
  font-size: 20px;_x000D_
  line-height: 30px;_x000D_
  color: hsla(0, 0%, 80%, 1);_x000D_
  background-color: hsla(0, 0%, 20%, 1);_x000D_
  cursor: pointer;_x000D_
}_x000D_
.menu-item:hover {_x000D_
  background-color: hsla(0, 40%, 40%, 1);_x000D_
}_x000D_
_x000D_
.content-block-header {_x000D_
  display: flex;_x000D_
  justify-content: center;_x000D_
  font-size: 20px;_x000D_
  line-height: 30px;_x000D_
  color: hsla(0, 0%, 90%, 1);_x000D_
  background-color: hsla(0, 50%, 50%, 1);_x000D_
}
_x000D_
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.9.1/jquery.min.js"></script>_x000D_
<div class="menu-wrapper">_x000D_
  <div class="menu-item" ss="about">About Us</div>_x000D_
  <div class="menu-item" ss="services">Services</div>_x000D_
  <div class="menu-item" ss="contact">Contact</div>_x000D_
</div>_x000D_
_x000D_
<div class="content-block-header" id="about">About Us</div>_x000D_
<div class="content-block">_x000D_
  Lorem ipsum dolor sit we gonna chung, crazy adipiscing phat. Nullizzle sapizzle velizzle, shut the shizzle up volutpizzle, suscipizzle quizzle, away vizzle, arcu. Pellentesque my shizz sure. Sed erizzle. I'm in the shizzle izzle funky fresh dapibus turpis tempus shizzlin dizzle. Maurizzle my shizz nibh izzle turpizzle. Gangsta izzle fo shizzle mah nizzle fo rizzle, mah home g-dizzle. I'm in the shizzle eleifend rhoncizzle fo shizzle my nizzle. In rizzle habitasse crazy dictumst. Yo dapibus. Curabitizzle tellizzle urna, pretizzle break it down, mattis izzle, eleifend rizzle, nunc. My shizz suscipit. Integer check it out funky fresh sizzle pizzle._x000D_
_x000D_
That's the shizzle et dizzle quis nisi sheezy mollis. Suspendisse bizzle. Morbi odio. Vivamizzle boofron. Crizzle orci. Cras mauris its fo rizzle, interdizzle a, we gonna chung amizzle, break it down izzle, pizzle. Pellentesque rizzle. Vestibulum its fo rizzle mi, volutpat uhuh ... yih!, ass funky fresh, adipiscing semper, fo shizzle. Crizzle izzle ipsum. We gonna chung mammasay mammasa mamma oo sa stuff brizzle yo. Cras ass justo nizzle purizzle sodales break it down. Check it out venenatizzle justo yo shut the shizzle up. Nunc crackalackin. Suspendisse bow wow wow placerizzle sure. Fizzle eu ante. Nunc that's the shizzle, leo eu gangster hendrerizzle, gangsta felis elementum pizzle, sizzle aliquizzle crunk bizzle luctus pede. Nam a nisl. Fo shizzle da bomb taciti gangster stuff i'm in the shizzle i'm in the shizzle per conubia you son of a bizzle, per inceptos its fo rizzle. Check it out break it down, neque izzle cool nonummy, tellivizzle orci viverra leo, bizzle semper risizzle arcu fo shizzle mah nizzle._x000D_
</div>_x000D_
<div class="content-block-header" id="services">Services</div>_x000D_
<div class="content-block">_x000D_
Lorem ipsum dolor sit we gonna chung, crazy adipiscing phat. Nullizzle sapizzle velizzle, shut the shizzle up volutpizzle, suscipizzle quizzle, away vizzle, arcu. Pellentesque my shizz sure. Sed erizzle. I'm in the shizzle izzle funky fresh dapibus turpis tempus shizzlin dizzle. Maurizzle my shizz nibh izzle turpizzle. Gangsta izzle fo shizzle mah nizzle fo rizzle, mah home g-dizzle. I'm in the shizzle eleifend rhoncizzle fo shizzle my nizzle. In rizzle habitasse crazy dictumst. Yo dapibus. Curabitizzle tellizzle urna, pretizzle break it down, mattis izzle, eleifend rizzle, nunc. My shizz suscipit. Integer check it out funky fresh sizzle pizzle._x000D_
_x000D_
That's the shizzle et dizzle quis nisi sheezy mollis. Suspendisse bizzle. Morbi odio. Vivamizzle boofron. Crizzle orci. Cras mauris its fo rizzle, interdizzle a, we gonna chung amizzle, break it down izzle, pizzle. Pellentesque rizzle. Vestibulum its fo rizzle mi, volutpat uhuh ... yih!, ass funky fresh, adipiscing semper, fo shizzle. Crizzle izzle ipsum. We gonna chung mammasay mammasa mamma oo sa stuff brizzle yo. Cras ass justo nizzle purizzle sodales break it down. Check it out venenatizzle justo yo shut the shizzle up. Nunc crackalackin. Suspendisse bow wow wow placerizzle sure. Fizzle eu ante. Nunc that's the shizzle, leo eu gangster hendrerizzle, gangsta felis elementum pizzle, sizzle aliquizzle crunk bizzle luctus pede. Nam a nisl. Fo shizzle da bomb taciti gangster stuff i'm in the shizzle i'm in the shizzle per conubia you son of a bizzle, per inceptos its fo rizzle. Check it out break it down, neque izzle cool nonummy, tellivizzle orci viverra leo, bizzle semper risizzle arcu fo shizzle mah nizzle._x000D_
</div>_x000D_
<div class="content-block-header" id="contact">Contact</div>_x000D_
<div class="content-block">_x000D_
  Lorem ipsum dolor sit we gonna chung, crazy adipiscing phat. Nullizzle sapizzle velizzle, shut the shizzle up volutpizzle, suscipizzle quizzle, away vizzle, arcu. Pellentesque my shizz sure. Sed erizzle. I'm in the shizzle izzle funky fresh dapibus turpis tempus shizzlin dizzle. Maurizzle my shizz nibh izzle turpizzle. Gangsta izzle fo shizzle mah nizzle fo rizzle, mah home g-dizzle. I'm in the shizzle eleifend rhoncizzle fo shizzle my nizzle. In rizzle habitasse crazy dictumst. Yo dapibus. Curabitizzle tellizzle urna, pretizzle break it down, mattis izzle, eleifend rizzle, nunc. My shizz suscipit. Integer check it out funky fresh sizzle pizzle._x000D_
_x000D_
That's the shizzle et dizzle quis nisi sheezy mollis. Suspendisse bizzle. Morbi odio. Vivamizzle boofron. Crizzle orci. Cras mauris its fo rizzle, interdizzle a, we gonna chung amizzle, break it down izzle, pizzle. Pellentesque rizzle. Vestibulum its fo rizzle mi, volutpat uhuh ... yih!, ass funky fresh, adipiscing semper, fo shizzle. Crizzle izzle ipsum. We gonna chung mammasay mammasa mamma oo sa stuff brizzle yo. Cras ass justo nizzle purizzle sodales break it down. Check it out venenatizzle justo yo shut the shizzle up. Nunc crackalackin. Suspendisse bow wow wow placerizzle sure. Fizzle eu ante. Nunc that's the shizzle, leo eu gangster hendrerizzle, gangsta felis elementum pizzle, sizzle aliquizzle crunk bizzle luctus pede. Nam a nisl. Fo shizzle da bomb taciti gangster stuff i'm in the shizzle i'm in the shizzle per conubia you son of a bizzle, per inceptos its fo rizzle. Check it out break it down, neque izzle cool nonummy, tellivizzle orci viverra leo, bizzle semper risizzle arcu fo shizzle mah nizzle._x000D_
</div>
_x000D_
_x000D_
_x000D_

Fiddle

https://jsfiddle.net/Hastig/stcstmph/4/

Sort Pandas Dataframe by Date

@JAB's answer is fast and concise. But it changes the DataFrame you are trying to sort, which you may or may not want.

(Note: You almost certainly will want it, because your date columns should be dates, not strings!)

In the unlikely event that you don't want to change the dates into dates, you can also do it a different way.

First, get the index from your sorted Date column:

In [25]: pd.to_datetime(df.Date).order().index
Out[25]: Int64Index([0, 2, 1], dtype='int64')

Then use it to index your original DataFrame, leaving it untouched:

In [26]: df.ix[pd.to_datetime(df.Date).order().index]
Out[26]: 
        Date Symbol
0 2015-02-20      A
2 2015-08-21      A
1 2016-01-15      A

Magic!

Note: for Pandas versions 0.20.0 and later, use loc instead of ix, which is now deprecated.

Converting VS2012 Solution to VS2010

Simple solution which worked for me.

  1. Install Vim editor for windows.
  2. Open VS 2012 project solution using Vim editor and modify the version targetting Visual studio solution 10.
  3. Open solution with Visual studio 2010.. and continue with your work ;)

find . -type f -exec chmod 644 {} ;

I need this so often that I created a function in my ~/.bashrc file:

chmodf() {
        find $2 -type f -exec chmod $1 {} \;
}
chmodd() {
        find $2 -type d -exec chmod $1 {} \;
}

Now I can use these shortcuts:

chmodd 0775 .
chmodf 0664 .

GCM with PHP (Google Cloud Messaging)

Here's a library I forked from CodeMonkeysRU.

The reason I forked was because Google requires exponential backoff. I use a redis server to queue messages and resend after a set time.

I've also updated it to support iOS.

https://github.com/stevetauber/php-gcm-queue

How to get URL parameter using jQuery or plain JavaScript?

Another solution that uses jQuery and JSON, so you can access the parameter values through an object.

var loc = window.location.href;
var param = {};
if(loc.indexOf('?') > -1)
{
    var params = loc.substr(loc.indexOf('?')+1, loc.length).split("&");

    var stringJson = "{";
    for(var i=0;i<params.length;i++)
    {
        var propVal = params[i].split("=");
        var paramName = propVal[0];
        var value = propVal[1];
        stringJson += "\""+paramName+"\": \""+value+"\"";
        if(i != params.length-1) stringJson += ",";
    }
    stringJson += "}";
    // parse string with jQuery parseJSON
    param = $.parseJSON(stringJson);
}

Assuming your URL is http://example.com/?search=hello+world&language=en&page=3

After that it's only a matter of using the parameters like this:

param.language

to return

en

The most useful usage of this is to run it at page load and make use of a global variable to use the parameters anywhere you might need them.

If your parameter contains numeric values then just parse the value.

parseInt(param.page)

If there are no parameters param will just be an empty object.

Convert any object to a byte[]

Using Encoding.UTF8.GetBytes is faster than using MemoryStream. Here, I am using NewtonsoftJson to convert input object to JSON string and then getting bytes from JSON string.

byte[] SerializeObject(object value) =>Encoding.UTF8.GetBytes(JsonConvert.SerializeObject(value));

Benchmark for @Daniel DiPaolo's version with this version

Method                    |     Mean |     Error |    StdDev |   Median |  Gen 0 | Allocated |
--------------------------|----------|-----------|-----------|----------|--------|-----------| 
ObjectToByteArray         | 4.983 us | 0.1183 us | 0.2622 us | 4.887 us | 0.9460 |    3.9 KB |
ObjectToByteArrayWithJson | 1.548 us | 0.0309 us | 0.0690 us | 1.528 us | 0.3090 |   1.27 KB |

C#/Linq: Apply a mapping function to each element in an IEnumerable?

You're looking for Select which can be used to transform\project the input sequence:

IEnumerable<string> strings = integers.Select(i => i.ToString());

How can I filter a date of a DateTimeField in Django?

This produces the same results as using __year, __month, and __day and seems to work for me:

YourModel.objects.filter(your_datetime_field__startswith=datetime.date(2009,8,22))

Using async/await with a forEach loop

Similar to Antonio Val's p-iteration, an alternative npm module is async-af:

const AsyncAF = require('async-af');
const fs = require('fs-promise');

function printFiles() {
  // since AsyncAF accepts promises or non-promises, there's no need to await here
  const files = getFilePaths();

  AsyncAF(files).forEach(async file => {
    const contents = await fs.readFile(file, 'utf8');
    console.log(contents);
  });
}

printFiles();

Alternatively, async-af has a static method (log/logAF) that logs the results of promises:

const AsyncAF = require('async-af');
const fs = require('fs-promise');

function printFiles() {
  const files = getFilePaths();

  AsyncAF(files).forEach(file => {
    AsyncAF.log(fs.readFile(file, 'utf8'));
  });
}

printFiles();

However, the main advantage of the library is that you can chain asynchronous methods to do something like:

const aaf = require('async-af');
const fs = require('fs-promise');

const printFiles = () => aaf(getFilePaths())
  .map(file => fs.readFile(file, 'utf8'))
  .forEach(file => aaf.log(file));

printFiles();

async-af

Remove all unused resources from an android project

When we define shrink resources true that time we can also define which resources we wanna keep and which don't I have added xml file in res/raw folder named keep.xml

before going further generate a single signed build and check in apk analyser tool which will show drawable-xhdpi-v4 has messenger_button_send_round_shadow.png which i want to remove for this test

<?xml version="1.0" encoding="utf-8"?>
<resources xmlns:tools="http://schemas.android.com/tools"
       tools:shrinkMode="strict"
       tools:discard="@drawable/com_facebook_button_icon_blue.png,
       @drawable/com_facebook_button_icon_white.png,
       @drawable/com_facebook_button_like_icon_selected.png,
       @drawable/messenger_button_send_round_shadow.png,
       @drawable/messenger_*"  />

by doing messenger_* all files starting from name messenger in drawable folder will be removed or other way around is i have defines specific file to be removed

so that way you can remove files from library it self you can also remove layouts by @layout/layout name if that drawable has been used by layout and so....

How can I parse / create a date time stamp formatted with fractional seconds UTC timezone (ISO 8601, RFC 3339) in Swift?

There is a new ISO8601DateFormatter class that let's you create a string with just one line. For backwards compatibility I used an old C-library. I hope this is useful for someone.

Swift 3.0

extension Date {
    var iso8601: String {
        if #available(OSX 10.12, iOS 10.0, watchOS 3.0, tvOS 10.0, *) {
            return ISO8601DateFormatter.string(from: self, timeZone: TimeZone.current, formatOptions: .withInternetDateTime)
        } else {
            var buffer = [CChar](repeating: 0, count: 25)
            var time = time_t(self.timeIntervalSince1970)
            strftime_l(&buffer, buffer.count, "%FT%T%z", localtime(&time), nil)
            return String(cString: buffer)
        }
    }
}

How to connect android wifi to adhoc wifi?

If you specifically want to use an ad hoc wireless network, then Andy's answer seems to be your only option. However, if you just want to share your laptop's internet connection via Wi-fi using any means necessary, then you have at least two more options:

  1. Use your laptop as a router to create a wifi hotspot using Virtual Router or Connectify. A nice set of instructions can be found here.
  2. Use the Wi-fi Direct protocol which creates a direct connection between any devices that support it, although with Android devices support is limited* and with Windows the feature seems likely to be Windows 8 only.

*Some phones with Android 2.3 have proprietary OS extensions that enable Wi-fi Direct (mostly newer Samsung phones), but Android 4 should fully support this (source).

Get Client Machine Name in PHP

Not in PHP.
phpinfo(32) contains everything PHP able to know about particular client, and there is no [windows] computer name

Entity Framework - "An error occurred while updating the entries. See the inner exception for details"

I was facing the same problem and non of the above solutions helped me. In my Web Api 2 project, I had actually updated my database and had placed a unique constraint on an SQL table column. That was actually causing the problem. Simply Checking the the duplicate column values before inserting helped me fix the problem!

How do you uninstall the package manager "pip", if installed from source?

That way you haven't installed pip, you installed just the easy_install i.e. setuptools.

First you should remove all the packages you installed with easy_install using (see uninstall):

easy_install -m PackageName

This includes pip if you installed it using easy_install pip.

After this you remove the setuptools following the instructions from here:

If setuptools package is found in your global site-packages directory, you may safely remove the following file/directory:

setuptools-*.egg

If setuptools is installed in some other location such as the user site directory (eg: ~/.local, ~/Library/Python or %APPDATA%), then you may safely remove the following files:

pkg_resources.py
easy_install.py
setuptools/
setuptools-*.egg-info/

What exactly does a jar file contain?

A .jar file is akin to a .exe file. In essence, they are both executable zip files (different zip algorithms).

In a jar file, you will see folders and class files. Each class file is similar to your .o file, and is a compiled java archive.

If you wanted to see the code in a jar file, download a java decompiler (located here: http://java.decompiler.free.fr/?q=jdgui) and a .jar extractor (7zip works fine).

Joining pandas dataframes by column names

you can use the left_on and right_on options as follows:

pd.merge(frame_1, frame_2, left_on='county_ID', right_on='countyid')

I was not sure from the question if you only wanted to merge if the key was in the left hand dataframe. If that is the case then the following will do that (the above will in effect do a many to many merge)

pd.merge(frame_1, frame_2, how='left', left_on='county_ID', right_on='countyid')

Git Remote: Error: fatal: protocol error: bad line length character: Unab

It could be a security access on your machine, are you running Pageant (which is a putty agent)?

How to set Bullet colors in UL/LI html lists via CSS without using any images or span tags

I simply solve this problem like this, which should work in all browsers:

_x000D_
_x000D_
ul li {
  color: red
}

ul li span {
  color: blue;
}
_x000D_
<ul>
  <li><span>Foo</span></li>
  <li><span>Bar</span></li>
  <li><span>Bat</span></li>
</ul>
_x000D_
_x000D_
_x000D_

How can I select all rows with sqlalchemy?

I use the following snippet to view all the rows in a table. Use a query to find all the rows. The returned objects are the class instances. They can be used to view/edit the values as required:

from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy import create_engine, Sequence
from sqlalchemy import String, Integer, Float, Boolean, Column
from sqlalchemy.orm import sessionmaker

Base = declarative_base()

class MyTable(Base):
    __tablename__ = 'MyTable'
    id = Column(Integer, Sequence('user_id_seq'), primary_key=True)
    some_col = Column(String(500))

    def __init__(self, some_col):
        self.some_col = some_col

engine = create_engine('sqlite:///sqllight.db', echo=True)
Session = sessionmaker(bind=engine)
session = Session()

for class_instance in session.query(MyTable).all():
    print(vars(class_instance))

session.close()

How to do fade-in and fade-out with JavaScript and CSS

The following javascript will fade in an element from opacity 0 to whatever the opacity value was at the time of calling fade in. You can also set the duration of the animation which is nice:

    function fadeIn(element) {
        var duration = 0.5;
        var interval = 10;//ms
        var op = 0.0;
        var iop = element.style.opacity;
        var timer = setInterval(function () {
            if (op >= iop) {
                op = iop;
                clearInterval(timer);
            }
            element.style.opacity = op;
            op += iop/((1000/interval)*duration);
        }, interval);
    }

*Based on IBUs answer but modified to account for previous opacity value and ability to set duration, also removed irrelevant CSS changes it was making

HTTP Error 503. The service is unavailable. App pool stops on accessing website

I had a similar issue. I solved it by adding my user to the "Log on as a batch job" policy under "Local Security Policy" > "Local Policies" > "User Rights Assignment".

How to install a Notepad++ plugin offline?

Open the Notepad++ as administrator, then import the .dll from the plugin folder that you pasted inside C:Program File/Notepad++/plugins/

What possibilities can cause "Service Unavailable 503" error?

If the server doesn't have enough memory also will cause this problem. This is my personal experience with Godaddy VPS.

UnhandledPromiseRejectionWarning: This error originated either by throwing inside of an async function without a catch block

.catch(error => { throw error}) is a no-op. It results in unhandled rejection in route handler.

As explained in this answer, Express doesn't support promises, all rejections should be handled manually:

router.get("/emailfetch", authCheck, async (req, res, next) => {
  try {
  //listing messages in users mailbox 
    let emailFetch = await gmaiLHelper.getEmails(req.user._doc.profile_id , '/messages', req.user.accessToken)
    emailFetch = emailFetch.data
    res.send(emailFetch)
  } catch (err) {
    next(err);
  }
})

What are the default access modifiers in C#?

Internal is the default modifier

How to add a hook to the application context initialization event?

Please follow below step to do some processing after Application Context get loaded i.e application is ready to serve.

  1. Create below annotation i.e

    @Retention(RetentionPolicy.RUNTIME) @Target(value= {ElementType.METHOD, ElementType.TYPE}) public @interface AfterApplicationReady {}

2.Create Below Class which is a listener which get call on application ready state.

    @Component
    public class PostApplicationReadyListener implements ApplicationListener<ApplicationReadyEvent> {

    public static final Logger LOGGER = LoggerFactory.getLogger(PostApplicationReadyListener.class);
    public static final String MODULE = PostApplicationReadyListener.class.getSimpleName();

    @Override
    public void onApplicationEvent(ApplicationReadyEvent event) {
        try {
            ApplicationContext context = event.getApplicationContext();
            String[] beans = context.getBeanNamesForAnnotation(AfterAppStarted.class);

            LOGGER.info("bean found with AfterAppStarted annotation are : {}", Arrays.toString(beans));

            for (String beanName : beans) {
                Object bean = context.getBean(beanName);
                Class<?> targetClass = AopUtils.getTargetClass(bean);
                Method[] methods = targetClass.getMethods();
                for (Method method : methods) {
                    if (method.isAnnotationPresent(AfterAppStartedComplete.class)) {

                        LOGGER.info("Method:[{} of Bean:{}] found with AfterAppStartedComplete Annotation.", method.getName(), beanName);

                        Method currentMethod = bean.getClass().getMethod(method.getName(), method.getParameterTypes());

                        LOGGER.info("Going to invoke method:{} of bean:{}", method.getName(), beanName);

                        currentMethod.invoke(bean);

                        LOGGER.info("Invocation compeleted method:{} of bean:{}", method.getName(), beanName);
                    }
                }
            }
        } catch (Exception e) {
            LOGGER.warn("Exception occured : ", e);
        }
    }
}

Finally when you start your Spring application just before log stating application started your listener will be called.

How do I convert Int/Decimal to float in C#?

You don't even need to cast, it is implicit.

int i = 3;

float f = i;

A full list/table of implicit numeric conversions can be seen here http://msdn.microsoft.com/en-us/library/y5b434w4.aspx

What exactly is nullptr?

0 used to be the only integer value that could be used as a cast-free initializer for pointers: you can not initialize pointers with other integer values without a cast. You can consider 0 as a consexpr singleton syntactically similar to an integer literal. It can initiate any pointer or integer. But surprisingly, you'll find that it has no distinct type: it is an int. So how come 0 can initialize pointers and 1 cannot? A practical answer was we need a means of defining pointer null value and direct implicit conversion of int to a pointer is error-prone. Thus 0 became a real freak weirdo beast out of the prehistoric era. nullptr was proposed to be a real singleton constexpr representation of null value to initialize pointers. It can not be used to directly initialize integers and eliminates ambiguities involved with defining NULL in terms of 0. nullptr could be defined as a library using std syntax but semantically looked to be a missing core component. NULL is now deprecated in favor of nullptr, unless some library decides to define it as nullptr.

Python: Find in list

If you want to find one element or None use default in next, it won't raise StopIteration if the item was not found in the list:

first_or_default = next((x for x in lst if ...), None)

Dropping Unique constraint from MySQL table

A unique constraint is also an index.

First use SHOW INDEX FROM tbl_name to find out the name of the index. The name of the index is stored in the column called key_name in the results of that query.

Then you can use DROP INDEX:

DROP INDEX index_name ON tbl_name

or the ALTER TABLE syntax:

ALTER TABLE tbl_name DROP INDEX index_name

How to redirect siteA to siteB with A or CNAME records

Try changing it to "subdomain -> subdomain.hosttwo.com"

The CNAME is an alias for a certain domain, so when you go to the control panel for hostone.com, you shouldn't have to enter the whole name into the CNAME alias.

As far as the error you are getting, can you log onto subdomain.hostwo.com and check the logs?

Setting a divs background image to fit its size?

Use this as it can also act as responsive. :

background-size: cover;

Action Bar's onClick listener for the Home button

Fixed: no need to use a setOnMenuItemClickListener. Just pressing the button, it creates and launches the activity through the intent.

Thanks a lot everybody for your help!

What exactly is an instance in Java?

Objects, which are also called instances, are self-contained elements of a program with related features and data. For the most part, you use the class merely to create instances and then work with those instances.

-Definition taken from the book "Sams Teach Yourself Java in 21 days".

Say you have 2 Classes, public class MainClass and public class Class_2 and you want to make an instance of Class_2 in MainClass.

This is a very simple and basic way to do it:

public MainClass()      /*******this is the constructor of MainClass*******/

{

 Class_2 nameyouwant = new Class_2();

}

I hope this helps!

How to get the previous URL in JavaScript?

document.referrer is not the same as the actual URL in all situations.

I have an application where I need to establish a frameset with 2 frames. One frame is known, the other is the page I am linking from. It would seem that document.referrer would be ideal because you would not have to pass the actual file name to the frameset document.

However, if you later change the bottom frame page and then use history.back() it does not load the original page into the bottom frame, instead it reloads document.referrer and as a result the frameset is gone and you are back to the original starting window.

Took me a little while to understand this. So in the history array, document.referrer is not only a URL, it is apparently the referrer window specification as well. At least, that is the best way I can understand it at this time.

FAIL - Application at context path /Hello could not be started

Your web.xml ends with <web-app>, but must end with </web-app>

Which by the way is almost literally what the exception tells you.

Cannot assign requested address - possible causes?

sysctl -w net.ipv4.tcp_timestamps=1
sysctl -w net.ipv4.tcp_tw_recycle=1

How do you count the number of occurrences of a certain substring in a SQL varchar?

Building on @Andrew's solution, you'll get much better performance using a non-procedural table-valued-function and CROSS APPLY:

SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
/*  Usage:
    SELECT t.[YourColumn], c.StringCount
    FROM YourDatabase.dbo.YourTable t
        CROSS APPLY dbo.CountOccurrencesOfString('your search string',     t.[YourColumn]) c
*/
CREATE FUNCTION [dbo].[CountOccurrencesOfString]
(
    @searchTerm nvarchar(max),
    @searchString nvarchar(max)

)
RETURNS TABLE
AS
    RETURN 
    SELECT (DATALENGTH(@searchString)-DATALENGTH(REPLACE(@searchString,@searchTerm,'')))/NULLIF(DATALENGTH(@searchTerm), 0) AS StringCount

How can I get a list of all open named pipes in Windows?

You can view these with Process Explorer from sysinternals. Use the "Find -> Find Handle or DLL..." option and enter the pattern "\Device\NamedPipe\". It will show you which processes have which pipes open.

Failed binder transaction when putting an bitmap dynamically in a widget

This is caused because all the changes to the RemoteViews are serialised (e.g. setInt and setImageViewBitmap ). The bitmaps are also serialised into an internal bundle. Unfortunately this bundle has a very small size limit.

You can solve it by scaling down the image size this way:

 public static Bitmap scaleDownBitmap(Bitmap photo, int newHeight, Context context) {

 final float densityMultiplier = context.getResources().getDisplayMetrics().density;        

 int h= (int) (newHeight*densityMultiplier);
 int w= (int) (h * photo.getWidth()/((double) photo.getHeight()));

 photo=Bitmap.createScaledBitmap(photo, w, h, true);

 return photo;
 }

Choose newHeight to be small enough (~100 for every square it should take on the screen) and use it for your widget, and your problem will be solved :)

Difference between jQuery .hide() and .css("display", "none")

see http://api.jquery.com/show/

With no parameters, the .show() method is the simplest way to display an element:

$('.target').show();

The matched elements will be revealed immediately, with no animation. This is roughly equivalent to calling .css('display', 'block'), except that the display property is restored to whatever it was initially. If an element has a display value of inline, then is hidden and shown, it will once again be displayed inline.

Getting a POST variable

In addition to using Request.Form and Request.QueryString and depending on your specific scenario, it may also be useful to check the Page's IsPostBack property.

if (Page.IsPostBack)
{
  // HTTP Post
}
else
{
  // HTTP Get
}

how to have two headings on the same line in html

The following code will allow you to have two headings on the same line, the first left-aligned and the second right-aligned, and has the added advantage of keeping both headings on the same baseline.

The HTML Part:

<h1 class="text-left-right">
    <span class="left-text">Heading Goes Here</span>
    <span class="byline">Byline here</span>
</h1>

And the CSS:

.text-left-right {
    text-align: right;
    position: relative;
}
.left-text {
    left: 0;
    position: absolute;
}
.byline {
    font-size: 16px;
    color: rgba(140, 140, 140, 1);
}

Download files in laravel using Response::download

Try this.

public function getDownload()
{
    //PDF file is stored under project/public/download/info.pdf
    $file= public_path(). "/download/info.pdf";

    $headers = array(
              'Content-Type: application/pdf',
            );

    return Response::download($file, 'filename.pdf', $headers);
}

"./download/info.pdf"will not work as you have to give full physical path.

Update 20/05/2016

Laravel 5, 5.1, 5.2 or 5.* users can use the following method instead of Response facade. However, my previous answer will work for both Laravel 4 or 5. (the $header array structure change to associative array =>- the colon after 'Content-Type' was deleted - if we don't do those changes then headers will be added in wrong way: the name of header wil be number started from 0,1,...)

$headers = [
              'Content-Type' => 'application/pdf',
           ];

return response()->download($file, 'filename.pdf', $headers);

Checking for the correct number of arguments

cat script.sh

    var1=$1
    var2=$2
    if [ "$#" -eq 2 ]
    then
            if [ -d $var1 ]
            then
            echo directory ${var1} exist
            else
            echo Directory ${var1} Does not exists
            fi
            if [ -d $var2 ]
            then
            echo directory ${var2} exist
            else
            echo Directory ${var2} Does not exists
            fi
    else
    echo "Arguments are not equals to 2"
    exit 1
    fi

execute it like below -

./script.sh directory1 directory2

Output will be like -

directory1 exit
directory2 Does not exists

Android : How to set onClick event for Button in List item of ListView

In Adapter Class

public View getView(final int position, View convertView, ViewGroup parent) {
    LayoutInflater inflater = getLayoutInflater();
    View row = inflater.inflate(R.layout.vehicals_details_row, parent, false);
    Button deleteImageView = (Button) row.findViewById(R.id.DeleteImageView);
    deleteImageView.setOnClickListener(new OnClickListener() {
        public void onClick(View v) {
            //...
        }
    });
}

But you can get an issue - listView row not clickable. Solution:

  • make ListView focusable android:focusable="true"
  • Button not focusable android:focusable="false"

How do I vertically align something inside a span tag?

I needed this for links, so I wrapped the span with an a-tag and a div, then centered the span tag itself

HTML

<div>
    <a class="tester" href="#">
        <span>Home</span>
    </a>
</div>

CSS

.tester{
    display: inline-block;
    width: 9em;
    height: 3em;
    text-align: center;
}
.tester>span{
    position: relative;
    top: 25%;
}

Assign multiple values to array in C

If you are doing these same assignments a lot in your program and want a shortcut, the most straightforward solution might be to just add a function

static inline void set_coordinates(
        GLfloat coordinates[static 8],
        GLfloat c0, GLfloat c1, GLfloat c2, GLfloat c3,
        GLfloat c4, GLfloat c5, GLfloat c6, GLfloat c7)
{
    coordinates[0] = c0;
    coordinates[1] = c1;
    coordinates[2] = c2;
    coordinates[3] = c3;
    coordinates[4] = c4;
    coordinates[5] = c5;
    coordinates[6] = c6;
    coordinates[7] = c7;
}

and then simply call

GLfloat coordinates[8];
// ...
set_coordinates(coordinates, 1.0f, 0.0f, 1.0f, 1.0f, 0.0f, 1.0f, 0.0f, 0.0f);

How to add local .jar file dependency to build.gradle file?

If you really need to take that .jar from a local directory,

Add next to your module gradle (Not the app gradle file):

repositories {
   flatDir {
       dirs 'libs'
   }
}


dependencies {
   implementation name: 'gson-2.2.4'
}

However, being a standard .jar in an actual maven repository, why don't you try this?

repositories {
   mavenCentral()
}
dependencies {
   implementation 'com.google.code.gson:gson:2.2.4'
}

React this.setState is not a function

Here THIS context is getting changed. Use arrow function to keep context of React class.

        VK.init(() => {
            console.info("API initialisation successful");
            VK.api('users.get',{fields: 'photo_50'},(data) => {
                if(data.response){
                    this.setState({ //the error happens here
                        FirstName: data.response[0].first_name
                    });
                    console.info(this.state.FirstName);
                }

            });
        }, function(){
        console.info("API initialisation failed");

        }, '5.34');

How to link to specific line number on github

Click the line number, and then copy and paste the link from the address bar. To select a range, click the number, and then shift click the later number.

Alternatively, the links are a relatively simple format, just append #L<number> to the end for that specific line number, using the link to the file. Here's a link to the third line of the git repository's README:

https://github.com/git/git/blob/master/README#L3

Screenshot with highlighted line and the modified address line

jQuery: read text file from file system

this one is working

        $.get('1.txt', function(data) {
            //var fileDom = $(data);

            var lines = data.split("\n");

            $.each(lines, function(n, elem) {
                $('#myContainer').append('<div>' + elem + '</div>');
            });
        });

CMake complains "The CXX compiler identification is unknown"

Run apt-get install build-essential on your system.

This package depends on other packages considered to be essential for builds and will install them. If you find you have to build packages, this can be helpful to avoid piecemeal resolution of dependencies.

See this page for more info.

How do I detect if a user is already logged in Firebase?

use Firebase.getAuth(). It returns the current state of the Firebase client. Otherwise the return value is nullHere are the docs: https://www.firebase.com/docs/web/api/firebase/getauth.html

Is there a bash command which counts files?

To count everything just pipe ls to word count line:

ls | wc -l

To count with pattern, pipe to grep first:

ls | grep log | wc -l

How can I read a text file from the SD card in Android?

In your layout you'll need something to display the text. A TextView is the obvious choice. So you'll have something like this:

<TextView 
    android:id="@+id/text_view" 
    android:layout_width="fill_parent" 
    android:layout_height="fill_parent"/>

And your code will look like this:

//Find the directory for the SD Card using the API
//*Don't* hardcode "/sdcard"
File sdcard = Environment.getExternalStorageDirectory();

//Get the text file
File file = new File(sdcard,"file.txt");

//Read text from file
StringBuilder text = new StringBuilder();

try {
    BufferedReader br = new BufferedReader(new FileReader(file));
    String line;

    while ((line = br.readLine()) != null) {
        text.append(line);
        text.append('\n');
    }
    br.close();
}
catch (IOException e) {
    //You'll need to add proper error handling here
}

//Find the view by its id
TextView tv = (TextView)findViewById(R.id.text_view);

//Set the text
tv.setText(text);

This could go in the onCreate() method of your Activity, or somewhere else depending on just what it is you want to do.

AngularJS 1.2 $injector:modulerr

Sometime I have seen this error when you are switching between the projects and running the projects on the same port one after the other. In that case goto chrome Developer Tools > Network and try to check the actual written js file for: if the file match with the workspce. To resolve this select Disable Cache under network.

Design Patterns web based applications

I have used the struts framework and find it fairly easy to learn. When using the struts framework each page of your site will have the following items.

1) An action which is used is called every time the HTML page is refreshed. The action should populate the data in the form when the page is first loaded and handles interactions between the web UI and the business layer. If you are using the jsp page to modify a mutable java object a copy of the java object should be stored in the form rather than the original so that the original data doesn't get modified unless the user saves the page.

2) The form which is used to transfer data between the action and the jsp page. This object should consist of a set of getter and setters for attributes that need to be accessible to the jsp file. The form also has a method to validate data before it gets persisted.

3) A jsp page which is used to render the final HTML of the page. The jsp page is a hybrid of HTML and special struts tags used to access and manipulate data in the form. Although struts allows users to insert Java code into jsp files you should be very cautious about doing that because it makes your code more difficult to read. Java code inside jsp files is difficult to debug and can not be unit tested. If you find yourself writing more than 4-5 lines of java code inside a jsp file the code should probably be moved to the action.

Angular2 : Can't bind to 'formGroup' since it isn't a known property of 'form'

Don't use userForm = new FormGroup()

Use form = new FormGroup() instead.

And in the form use <form [formGroup]="form"> ...</form>. It works for me with angular 6

Getting new Twitter API consumer and secret keys

  1. Log into the Twitter Developers section.

    • If you don't already have an account, you can login with your normal Twitter credentials
  2. Go to "Create an app"

  3. Fill in the details of the application you'll be using to connect with the API

    • Your application name must be unique. If someone else is already using it, you won't be able to register your application until you can think of something that isn't being used.
  4. Click on Create your Twitter application

  5. Details of your new app will be shown along with your consumer key and consumer secret.

  6. If you need access tokens, scroll down and click Create my access token

    • The page will then refresh on the "Details" tab with your new access tokens. You can recreate these at any time if you need to.

By default your apps will be granted for read-only access. To change this, go to the Settings tab and change the access level required in the "Application Type" section.

Existing apps

To get the consumer and access tokens for an existing application, go to My applications (which is available from the menu in the upper-right).

How to download source in ZIP format from GitHub?

Even though this is fairly an old question, I have my 2 cents to share.

You can download the repo as tar.gz as well

Like the zipball link pointed by various answers here, There is a tarball link as well which downloads the content of the git repository in tar.gz format.

curl -L http://github.com/zoul/Finch/tarball/master/

A better way

Git also provides a different URL pattern where you can simply append the type of file you want to download at the end of url. This way is better if you want to process these urls in a batch or bash script.

curl -L http://github.com/zoul/Finch/archive/master.zip

curl -L http://github.com/zoul/Finch/archive/master.tar.gz

To download a specific commit or branch

Replace master with the commit-hash or the branch-name in the above urls like below.

curl -L http://github.com/zoul/Finch/archive/cfeb671ac55f6b1aba6ed28b9bc9b246e0e.zip    
curl -L http://github.com/zoul/Finch/archive/cfeb671ac55f6b1aba6ed28b9bc9b246e0e.tar.gz

curl -L http://github.com/zoul/Finch/archive/your-branch-name.zip
curl -L http://github.com/zoul/Finch/archive/your-branch-name.tar.gz

Exception in thread "main" java.lang.UnsupportedClassVersionError: a (Unsupported major.minor version 51.0)

Try sudo update-alternatives --config java from the command line to set the version of the JRE you want to use. This should fix it.

Can't get Python to import from a different folder

After going through the answers given by these contributors above - Zorglub29, Tom, Mark, Aaron McMillin, lucasamaral, JoeyZhao, Kjeld Flarup, Procyclinsur, martin.zaenker, tooty44 and debugging the issue that I was facing I found out a different use case due to which I was facing this issue. Hence adding my observations below for anybody's reference.

In my code I had a cyclic import of classes. For example:

src
 |-- utilities.py (has Utilities class that uses Event class)  
 |-- consume_utilities.py (has Event class that uses Utilities class)
 |-- tests
      |-- test_consume_utilities.py (executes test cases that involves Event class)

I got following error when I tried to execute python -m pytest tests/test_utilities.py for executing UTs written in test_utilities.py.

ImportError while importing test module '/Users/.../src/tests/test_utilities.py'.
Hint: make sure your test modules/packages have valid Python names.
Traceback:
tests/test_utilities.py:1: in <module>
    from utilities import Utilities
...
...
E   ImportError: cannot import name 'Utilities'

The way I resolved the error was by re-factoring my code to move the functionality in cyclic import class so that I could remove the cyclic import of classes.

Note, I have __init__.py file in my 'src' folder as well as 'tests' folder and still was able to get rid of the 'ImportError' just by re-factoring the code.

Following stackoverflow link provides much more details on Circular dependency in Python.

How to use regex in XPath "contains" function

In Robins's answer ends-with is not supported in xpath 1.0 too.. Only starts-with is supported... So if your condition is not very specific..You can Use like this which worked for me

//*[starts-with(@id,'sometext') and contains(@name,'_text')]`\

Extract a subset of a dataframe based on a condition involving a field

Here are the two main approaches. I prefer this one for its readability:

bar <- subset(foo, location == "there")

Note that you can string together many conditionals with & and | to create complex subsets.

The second is the indexing approach. You can index rows in R with either numeric, or boolean slices. foo$location == "there" returns a vector of T and F values that is the same length as the rows of foo. You can do this to return only rows where the condition returns true.

foo[foo$location == "there", ]

Abstract Class:-Real Time Example

The best example of an abstract class is GenericServlet. GenericServlet is the parent class of HttpServlet. It is an abstract class.

When inheriting 'GenericServlet' in a custom servlet class, the service() method must be overridden.

ASP.net page without a code behind

yes on your aspx page include a script tag with runat=server

<script language="c#" runat="server">

public void Page_Load(object sender, EventArgs e)
{
  // some load code
}
</script>

You can also use classic ASP Syntax

<% if (this.MyTextBox.Visible) { %>
<span>Only show when myTextBox is visible</span>
<% } %>

What is PAGEIOLATCH_SH wait type in SQL Server?

From Microsoft documentation:

PAGEIOLATCH_SH

Occurs when a task is waiting on a latch for a buffer that is in an I/O request. The latch request is in Shared mode. Long waits may indicate problems with the disk subsystem.

In practice, this almost always happens due to large scans over big tables. It almost never happens in queries that use indexes efficiently.

If your query is like this:

Select * from <table> where <col1> = <value> order by <PrimaryKey>

, check that you have a composite index on (col1, col_primary_key).

If you don't have one, then you'll need either a full INDEX SCAN if the PRIMARY KEY is chosen, or a SORT if an index on col1 is chosen.

Both of them are very disk I/O consuming operations on large tables.

SQL Server: How to check if CLR is enabled?

SELECT * FROM sys.configurations
WHERE name = 'clr enabled'

What is an ORM, how does it work, and how should I use one?

Introduction

Object-Relational Mapping (ORM) is a technique that lets you query and manipulate data from a database using an object-oriented paradigm. When talking about ORM, most people are referring to a library that implements the Object-Relational Mapping technique, hence the phrase "an ORM".

An ORM library is a completely ordinary library written in your language of choice that encapsulates the code needed to manipulate the data, so you don't use SQL anymore; you interact directly with an object in the same language you're using.

For example, here is a completely imaginary case with a pseudo language:

You have a book class, you want to retrieve all the books of which the author is "Linus". Manually, you would do something like that:

book_list = new List();
sql = "SELECT book FROM library WHERE author = 'Linus'";
data = query(sql); // I over simplify ...
while (row = data.next())
{
     book = new Book();
     book.setAuthor(row.get('author');
     book_list.add(book);
}

With an ORM library, it would look like this:

book_list = BookTable.query(author="Linus");

The mechanical part is taken care of automatically via the ORM library.

Pros and Cons

Using ORM saves a lot of time because:

  • DRY: You write your data model in only one place, and it's easier to update, maintain, and reuse the code.
  • A lot of stuff is done automatically, from database handling to I18N.
  • It forces you to write MVC code, which, in the end, makes your code a little cleaner.
  • You don't have to write poorly-formed SQL (most Web programmers really suck at it, because SQL is treated like a "sub" language, when in reality it's a very powerful and complex one).
  • Sanitizing; using prepared statements or transactions are as easy as calling a method.

Using an ORM library is more flexible because:

  • It fits in your natural way of coding (it's your language!).
  • It abstracts the DB system, so you can change it whenever you want.
  • The model is weakly bound to the rest of the application, so you can change it or use it anywhere else.
  • It lets you use OOP goodness like data inheritance without a headache.

But ORM can be a pain:

  • You have to learn it, and ORM libraries are not lightweight tools;
  • You have to set it up. Same problem.
  • Performance is OK for usual queries, but a SQL master will always do better with his own SQL for big projects.
  • It abstracts the DB. While it's OK if you know what's happening behind the scene, it's a trap for new programmers that can write very greedy statements, like a heavy hit in a for loop.

How to learn about ORM?

Well, use one. Whichever ORM library you choose, they all use the same principles. There are a lot of ORM libraries around here:

If you want to try an ORM library in Web programming, you'd be better off using an entire framework stack like:

  • Symfony (PHP, using Propel or Doctrine).
  • Django (Python, using a internal ORM).

Do not try to write your own ORM, unless you are trying to learn something. This is a gigantic piece of work, and the old ones took a lot of time and work before they became reliable.

How to import js-modules into TypeScript file?

2021 Solution

If you're still getting this error message:

TS7016: Could not find a declaration file for module './myjsfile'

Then you might need to add the following to tsconfig.json

{
  "compilerOptions": {
    ...
    "allowJs": true,
    "checkJs": false,
    ...
  }
}

This prevents typescript from trying to apply module types to the imported javascript.

string.split - by multiple character delimiter

More fast way using directly a no-string array but a string:

string[] StringSplit(string StringToSplit, string Delimitator)
{
    return StringToSplit.Split(new[] { Delimitator }, StringSplitOptions.None);
}

StringSplit("E' una bella giornata oggi", "giornata");
/* Output
[0] "E' una bella giornata"
[1] " oggi"
*/

Parsing JSON array into java.util.List with Gson

Below code is using com.google.gson.JsonArray. I have printed the number of element in list as well as the elements in List

import java.util.ArrayList;

import com.google.gson.Gson;
import com.google.gson.JsonArray;
import com.google.gson.JsonObject;
import com.google.gson.JsonParser;


public class Test {

    static String str = "{ "+ 
            "\"client\":\"127.0.0.1\"," + 
            "\"servers\":[" + 
            "    \"8.8.8.8\"," + 
            "    \"8.8.4.4\"," + 
            "    \"156.154.70.1\"," + 
            "    \"156.154.71.1\" " + 
            "    ]" + 
            "}";

    public static void main(String[] args) {
        // TODO Auto-generated method stub
        try {

            JsonParser jsonParser = new JsonParser();
            JsonObject jo = (JsonObject)jsonParser.parse(str);
            JsonArray jsonArr = jo.getAsJsonArray("servers");
            //jsonArr.
            Gson googleJson = new Gson();
            ArrayList jsonObjList = googleJson.fromJson(jsonArr, ArrayList.class);
            System.out.println("List size is : "+jsonObjList.size());
                    System.out.println("List Elements are  : "+jsonObjList.toString());


        } catch (Exception e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }

}

OUTPUT

List size is : 4

List Elements are  : [8.8.8.8, 8.8.4.4, 156.154.70.1, 156.154.71.1]

NullPointerException: Attempt to invoke virtual method 'boolean java.lang.String.equalsIgnoreCase(java.lang.String)' on a null object reference

The exception occurs due to this statement,

called_from.equalsIgnoreCase("add")

It seem that the previous statement

String called_from = getIntent().getStringExtra("called");

returned a null reference.

You can check whether the intent to start this activity contains such a key "called".

jquery ajax function not working

Give this a go:

<form name="postcontent" id="postcontent">
    <input name="postsubmit" type="submit" id="postsubmit" value="POST"/>
    <textarea id="postdata" name="postdata" placeholder="What's Up ?"></textarea>
</form>
<script>
    (function() {
        $("#postcontent").on('submit', function(e) {
            e.preventDefault();
        $.ajax({
            type:"POST",
            url:"add_new_post.php",
            data:$("#postcontent").serialize(),
            beforeSend:function(){
                $(".post_submitting").show().html("<center><img src='images/loading.gif'/></center>");
            },success:function(response){   
                //alert(response);
                $("#return_update_msg").html(response); 
                $(".post_submitting").fadeOut(1000);                
            }
        });
   });
})();
</script>

Command output redirect to file and terminal

It is worth mentioning that 2>&1 means that standard error will be redirected too, together with standard output. So

someCommand | tee someFile

gives you just the standard output in the file, but not the standard error: standard error will appear in console only. To get standard error in the file too, you can use

someCommand 2>&1 | tee someFile

(source: In the shell, what is " 2>&1 "? ). Finally, both the above commands will truncate the file and start clear. If you use a sequence of commands, you may want to get output&error of all of them, one after another. In this case you can use -a flag to "tee" command:

someCommand 2>&1 | tee -a someFile

How do I pass along variables with XMLHTTPRequest

Following is correct way:

xmlhttp.open("GET","getuser.php?fname="+abc ,true);

Swift - iOS - Dates and times in different format

I used the a similar approach as @iod07, but as an extension. Also, I added some explanations in the comments to understand how it works.

Basically, just add this at the top or bottom of your view controller.

extension NSString {

class func convertFormatOfDate(date: String, originalFormat: String, destinationFormat: String) -> String! {

    // Orginal format :
    let dateOriginalFormat = NSDateFormatter()
    dateOriginalFormat.dateFormat = originalFormat      // in the example it'll take "yy MM dd" (from our call)

    // Destination format :
    let dateDestinationFormat = NSDateFormatter()
    dateDestinationFormat.dateFormat = destinationFormat // in the example it'll take "EEEE dd MMMM yyyy" (from our call)

    // Convert current String Date to NSDate
    let dateFromString = dateOriginalFormat.dateFromString(date)

    // Convert new NSDate created above to String with the good format
    let dateFormated = dateDestinationFormat.stringFromDate(dateFromString!)

    return dateFormated

}
}

Example

Let's say you want to convert "16 05 05" to "Thursday 05 May 2016" and your date is declared as follow let date = "16 06 05"

Then simply call call it with :

let newDate = NSString.convertFormatOfDate(date, originalFormat: "yy MM dd", destinationFormat: "EEEE dd MMMM yyyy")

Hope it helps !

How to extract numbers from string in c?

here after a simple solution using sscanf:

#include<stdio.h>
#include<stdlib.h>
#include<string.h>

char str[256]="ab234cid*(s349*(20kd";
char tmp[256];

int main()
{

    int x;
    tmp[0]='\0';
    while (sscanf(str,"%[^0123456789]%s",tmp,str)>1||sscanf(str,"%d%s",&x,str))
    {
        if (tmp[0]=='\0')
        {
            printf("%d\r\n",x);
        }
        tmp[0]='\0';

    }
}

How can I output a UTF-8 CSV in PHP that Excel will read properly?

I use this and it works

header('Content-Description: File Transfer');
header('Content-Type: text/csv; charset=UTF-16LE');
header('Content-Disposition: attachment; filename=file.csv');
header('Content-Transfer-Encoding: binary');
header('Expires: 0');
header('Cache-Control: must-revalidate, post-check=0, pre-check=0');
header('Pragma: public');
// output headers so that the file is downloaded rather than displayed
// create a file pointer connected to the output stream
$output = fopen('php://output', 'w');
fputs( $output, "\xEF\xBB\xBF" );
// output the column headings
fputcsv($output, array('Thông tin khách hàng dang ký'));
// fetch the data
$setutf8 = "SET NAMES utf8";
$q = $conn->query($setutf8);
$setutf8c = "SET character_set_results = 'utf8', character_set_client =
'utf8', character_set_connection = 'utf8', character_set_database = 'utf8',
character_set_server = 'utf8'";
$qc = $conn->query($setutf8c);
$setutf9 = "SET CHARACTER SET utf8";
$q1 = $conn->query($setutf9);
$setutf7 = "SET COLLATION_CONNECTION = 'utf8_general_ci'";
$q2 = $conn->query($setutf7);
$sql = "SELECT id, name, email FROM myguests";
$rows = $conn->query($sql);
$arr1= array();
if ($rows->num_rows > 0) {
// output data of each row
while($row = $rows->fetch_assoc()) {
    $rcontent = " Name: " . $row["name"]. " - Email: " . $row["email"];  
    $arr1[]["title"] =  $rcontent;
}
} else {
     echo "0 results";
}
$conn->close();
// loop over the rows, outputting them
foreach($arr1 as $result1):
   fputcsv($output, $result1);
endforeach;

How to scroll UITableView to specific position

It is worth noting that if you use the setContentOffset approach, it may cause your table view/collection view to jump a little. I would honestly try to go about this another way. A recommendation is to use the scroll view delegate methods you are given for free.

How to send SMS in Java

There are two ways : First : Use a SMS API Gateway which you need to pay for it , maybe you find some trial even free ones but it's scarce . Second : To use AT command with a modem GSM connected to your laptop . that's all

Eclipse java debugging: source not found

In my case, even after Editing source lookup and Adding project, it didn't worked. I configured the Build path of the project.

enter image description here

After that, I selected JRE System Library and it worked.

enter image description here

Max value of Xmx and Xms in Eclipse?

Why do you need -Xms768 (small heap must be at least 768...)?

That means any java process (search in eclipse) will start with 768m memory allocated, doesn't that? That is why your eclipse isn't able to start properly.

Try -Xms16 -Xmx2048m, for instance.

Subversion stuck due to "previous operation has not finished"?

I had the same problem, and somehow found that I had a hidden .svn file at the c:\ level. Once I deleted this hidden folder (.svn), everything worked okay. I must have unintentionally created a working directory at the root drive.

Get the Highlighted/Selected text

Getting the text the user has selected is relatively simple. There's no benefit to be gained by involving jQuery since you need nothing other than the window and document objects.

function getSelectionText() {
    var text = "";
    if (window.getSelection) {
        text = window.getSelection().toString();
    } else if (document.selection && document.selection.type != "Control") {
        text = document.selection.createRange().text;
    }
    return text;
}

If you're interested in an implementation that will also deal with selections in <textarea> and texty <input> elements, you could use the following. Since it's now 2016 I'm omitting the code required for IE <= 8 support but I've posted stuff for that in many places on SO.

_x000D_
_x000D_
function getSelectionText() {_x000D_
    var text = "";_x000D_
    var activeEl = document.activeElement;_x000D_
    var activeElTagName = activeEl ? activeEl.tagName.toLowerCase() : null;_x000D_
    if (_x000D_
      (activeElTagName == "textarea") || (activeElTagName == "input" &&_x000D_
      /^(?:text|search|password|tel|url)$/i.test(activeEl.type)) &&_x000D_
      (typeof activeEl.selectionStart == "number")_x000D_
    ) {_x000D_
        text = activeEl.value.slice(activeEl.selectionStart, activeEl.selectionEnd);_x000D_
    } else if (window.getSelection) {_x000D_
        text = window.getSelection().toString();_x000D_
    }_x000D_
    return text;_x000D_
}_x000D_
_x000D_
document.onmouseup = document.onkeyup = document.onselectionchange = function() {_x000D_
  document.getElementById("sel").value = getSelectionText();_x000D_
};
_x000D_
Selection:_x000D_
<br>_x000D_
<textarea id="sel" rows="3" cols="50"></textarea>_x000D_
<p>Please select some text.</p>_x000D_
<input value="Some text in a text input">_x000D_
<br>_x000D_
<input type="search" value="Some text in a search input">_x000D_
<br>_x000D_
<input type="tel" value="4872349749823">_x000D_
<br>_x000D_
<textarea>Some text in a textarea</textarea>
_x000D_
_x000D_
_x000D_

How add items(Text & Value) to ComboBox & read them in SelectedIndexChanged (SelectedValue = null)

try this:

ComboBox cbx = new ComboBox();
cbx.DisplayMember = "Text";
cbx.ValueMember = "Value";

EDIT (a little explanation, sory, I also didn't notice your combobox wasn't bound, I blame the lack of caffeine):

The difference between SelectedValue and SelectedItem are explained pretty well here: ComboBox SelectedItem vs SelectedValue

So, if your combobox is not bound to datasource, DisplayMember and ValueMember doesn't do anything, and SelectedValue will always be null, SelectedValueChanged won't be called. So either bind your combobox:

            comboBox1.DisplayMember = "Text";
            comboBox1.ValueMember = "Value";

            List<ComboboxItem> list = new List<ComboboxItem>();

            ComboboxItem item = new ComboboxItem();
            item.Text = "choose a server...";
            item.Value = "-1";
            list.Add(item);

            item = new ComboboxItem();
            item.Text = "S1";
            item.Value = "1";
            list.Add(item);

            item = new ComboboxItem();
            item.Text = "S2";
            item.Value = "2";
            list.Add(item);

            cbx.DataSource = list; // bind combobox to a datasource

or use SelectedItem property:

if (cbx.SelectedItem != null)
             Console.WriteLine("ITEM: "+comboBox1.SelectedItem.ToString());

Javascript decoding html entities

Using jQuery the easiest will be:

var text = '&lt;p&gt;name&lt;/p&gt;&lt;p&gt;&lt;span style="font-size:xx-small;"&gt;ajde&lt;/span&gt;&lt;/p&gt;&lt;p&gt;&lt;em&gt;da&lt;/em&gt;&lt;/p&gt;';

var output = $("<div />").html(text).text();
console.log(output);

DEMO: http://jsfiddle.net/LKGZx/

The difference between fork(), vfork(), exec() and clone()

in fork(), either child or parent process will execute based on cpu selection.. But in vfork(), surely child will execute first. after child terminated, parent will execute.

What's the most useful and complete Java cheat sheet?

It's not really a cheat-sheet, but for me I setup a 'java' search keyword in Google Chrome to search over the javadoc, using site:<javadoc_domain_here>.

You could do the same but also add the domain for the Sun Java Tutorial and for several Java FAQ sites and you'd be OK.

Otherwise, StackOverflow is a pretty good cheat-sheet :)

What are the differences between C, C# and C++ in terms of real-world applications?

Both C and C++ give you a lower level of abstraction that, with increased complexity, provides a breadth of access to underlying machine functionality that are not necessarily exposed with other languages. Compared to C, C++ adds the convenience of a fully object oriented language(reduced development time) which can, potentially, add an additional performance cost. In terms of real world applications, I see these languages applied in the following domains:

C

  • Kernel level software.
  • Hardware device drivers
  • Applications where access to old, stable code is required.

C,C++

  • Application or Server development where memory management needs to be fine tuned (and can't be left to generic garbage collection solutions).
  • Development environments that require access to libraries that do not interface well with more modern managed languages.
  • Although managed C++ can be used to access the .NET framework, it is not a seamless transition.

C# provides a managed memory model that adds a higher level of abstraction again. This level of abstraction adds convenience and improves development times, but complicates access to lower level APIs and makes specialized performance requirements problematic.

It is certainly possible to implement extremely high performance software in a managed memory environment, but awareness of the implications is essential.

The syntax of C# is certainly less demanding (and error prone) than C/C++ and has, for the initiated programmer, a shallower learning curve.

C#

  • Rapid client application development.
  • High performance Server development (StackOverflow for example) that benefits from the .NET framework.
  • Applications that require the benefits of the .NET framework in the language it was designed for.

Johannes Rössel makes the valid point that the use C# Pointers, Unsafe and Unchecked keywords break through the layer of abstraction upon which C# is built. I would emphasize that type of programming is the exception to most C# development scenarios and not a fundamental part of the language (as is the case with C/C++).

Practical uses of different data structures

As per my understanding data structure is any data residing in memory of any electronic system that can be efficiently managed. Many times it is a game of memory or faster accessibility of data. In terms of memory again, there are tradeoffs done with the management of data based on cost to the company of that end product. Efficiently managed tells us how best the data can be accessed based on the primary requirement of the end product. This is a very high level explanation but data structures is a vast subjects. Most of the interviewers dive into data structures that they can afford to discuss in the interviews depending on the time they have, which are linked lists and related subjects.

Now, these data types can be divided into primitive, abstract, composite, based on the way they are logically constructed and accessed.

  • primitive data structures are basic building blocks for all data structures, they have a continuous memory for them: boolean, char, int, float, double, string.
  • composite data structures are data structures that are composed of more than one primitive data types.class, structure, union, array/record.
  • abstract datatypes are composite datatypes that have way to access them efficiently which is called as an algorithm. Depending on the way the data is accessed data structures are divided into linear and non linear datatypes. Linked lists, stacks, queues, etc are linear data types. heaps, binary trees and hash tables etc are non linear data types.

I hope this helps you dive in.

What is the difference between Promises and Observables?

Short answer :

Observable is better, it has all Promises features plus extra features.


Long answer:

Promises:

  • One Time Use "Return data once"
  • No cancel
  • One listener
  • No Socket Support One Listener

Observable:

  • Return Data many times as data change
  • Support cancel
  • Support socket
  • Support many Listener and notify them when data change
  • Support map, filter, reduce

Datepicker: How to popup datepicker when click on edittext

<EditText
    android:id="@+id/date"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:ems="10"
    android:hint="DD/MM/YYYY"
    android:inputType="date"
    android:focusable="false"/>

<EditText
    android:id="@+id/time"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:hint="00:00"
    android:inputType="time"
    android:focusable="false"/>

JAVA FILE

import android.app.DatePickerDialog;
import android.app.TimePickerDialog;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.DatePicker;
import android.widget.EditText;
import android.widget.TimePicker;

import java.util.Calendar;

public class MainActivity extends AppCompatActivity implements View.OnClickListener {

    EditText selectDate,selectTime;
    private int mYear, mMonth, mDay, mHour, mMinute;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        selectDate=(EditText)findViewById(R.id.date);
        selectTime=(EditText)findViewById(R.id.time);

        selectDate.setOnClickListener(this);
        selectTime.setOnClickListener(this);




    }

    @Override
    public void onClick(View view) {

        if (view == selectDate) {
            final Calendar c = Calendar.getInstance();
            mYear = c.get(Calendar.YEAR);
            mMonth = c.get(Calendar.MONTH);
            mDay = c.get(Calendar.DAY_OF_MONTH);


            DatePickerDialog datePickerDialog = new DatePickerDialog(this,
                    new DatePickerDialog.OnDateSetListener() {

                        @Override
                        public void onDateSet(DatePicker view, int year,
                                              int monthOfYear, int dayOfMonth) {

                            selectDate.setText(dayOfMonth + "-" + (monthOfYear + 1) + "-" + year);

                        }
                    }, mYear, mMonth, mDay);
            datePickerDialog.show();
        }
        if (view == selectTime) {

            // Get Current Time
            final Calendar c = Calendar.getInstance();
            mHour = c.get(Calendar.HOUR_OF_DAY);
            mMinute = c.get(Calendar.MINUTE);

            // Launch Time Picker Dialog
            TimePickerDialog timePickerDialog = new TimePickerDialog(this,
                    new TimePickerDialog.OnTimeSetListener() {

                        @Override
                        public void onTimeSet(TimePicker view, int hourOfDay,
                                              int minute) {

                            selectTime.setText(hourOfDay + ":" + minute);
                        }
                    }, mHour, mMinute, false);
            timePickerDialog.show();
        }
    }
}

TokenMismatchException in VerifyCsrfToken.php Line 67

try changing the session lifetime on config/session.php like this :

'lifetime' => 120, to 'lifetime' => 360,

Here I set lifetime to 360, hope this help.

How can I display a messagebox in ASP.NET?

Make a method of MsgBox in your page.


public void MsgBox(String ex, Page pg,Object obj) 
{
    string s = "<SCRIPT language='javascript'>alert('" + ex.Replace("\r\n", "\\n").Replace("'", "") + "'); </SCRIPT>";
    Type cstype = obj.GetType();
    ClientScriptManager cs = pg.ClientScript;
    cs.RegisterClientScriptBlock(cstype, s, s.ToString());
}

and when you want to use msgbox just put this line

MsgBox("! your message !", this.Page, this);

What is the easiest way to get current GMT time in Unix timestamp format?

I like this method:

import datetime, time

dts = datetime.datetime.utcnow()
epochtime = round(time.mktime(dts.timetuple()) + dts.microsecond/1e6)

The other methods posted here are either not guaranteed to give you UTC on all platforms or only report whole seconds. If you want full resolution, this works, to the micro-second.

How to check whether a string is Base64 encoded or not

This works in Python:

def is_base64(string):
    if len(string) % 4 == 0 and re.test('^[A-Za-z0-9+\/=]+\Z', string):
        return(True)
    else:
        return(False)

Jquery sortable 'change' event element position

$( "#sortable" ).sortable({
    change: function(event, ui) {       
        var pos = ui.helper.index() < ui.placeholder.index() 
            ? { start: ui.helper.index(), end: ui.placeholder.index() }
            : { start: ui.placeholder.index(), end: ui.helper.index() }

        $(this)
            .children().removeClass( 'highlight' )
            .not( ui.helper ).slice( pos.start, pos.end ).addClass( 'highlight' );
    },
    stop: function(event, ui) {
        $(this).children().removeClass( 'highlight' );
    }
});

FIDDLE

An example of how it could be done inside change event without storing arbitrary data into element storage. Since the element where drag starts is ui.helper, and the element of current position is ui.placeholder, we can take the elements between those two indexes and highlight them. Also, we can use this inside handler since it refers to the element that the widget is attached. The example works with dragging in both directions.