Programs & Examples On #Bulletphysics

Bullet (Bullet Physics SDK) is an Open Source collision detection and rigid body dynamics library. The Library is free for commercial use and open source under the ZLib License.

How to expand and compute log(a + b)?

In general, one doesn't expand out log(a + b); you just deal with it as is. That said, there are occasionally circumstances where it makes sense to use the following identity:

log(a + b) = log(a * (1 + b/a)) = log a + log(1 + b/a)

(In fact, this identity is often used when implementing log in math libraries).

Could not load file or assembly System.Web.Http.WebHost after published to Azure web site

The dll is missing in the published (deployed environment). That is the reason why it is working in the local i.e. Visual Studio but not in the Azure Website Environment.

Just do Copy Local = true in the properties for the assembly(System.Web.Http.WebHost) and then do a redeploy, it should work fine.

If you get the similar error i.e. some other assembly missing, then make that assembly to copylocal=true and redeploy, repeat this iteratively - if you are unsure of its dependencies.

Messagebox with input field

You can reference Microsoft.VisualBasic.dll.

Then using the code below.

Microsoft.VisualBasic.Interaction.InputBox("Question?","Title","Default Text");

Alternatively, by adding a using directive allowing for a shorter syntax in your code (which I'd personally prefer).

using Microsoft.VisualBasic;
...
Interaction.InputBox("Question?","Title","Default Text");

Or you can do what Pranay Rana suggests, that's what I would've done too...

How to loop through each and every row, column and cells in a GridView and get its value

foreach (DataGridViewRow row in dataGridView1.Rows)
        {
            for (int i = 0; i < dataGridView1.Columns.Count; i++)
            {
                String header = dataGridView1.Columns[i].HeaderText;
                //String cellText = row.Cells[i].Text;
                DataGridViewColumn column = dataGridView1.Columns[i]; // column[1] selects the required column 
                column.AutoSizeMode = DataGridViewAutoSizeColumnMode.AllCells; // sets the AutoSizeMode of column defined in previous line
                int colWidth = column.Width; // store columns width after auto resize           
                colWidth += 50; // add 30 pixels to what 'colWidth' already is
                this.dataGridView1.Columns[i].Width = colWidth; // set the columns width to the value stored in 'colWidth'
            }
        }

Adding List<t>.add() another list

List<T>.Add adds a single element. Instead, use List<T>.AddRange to add multiple values.

Additionally, List<T>.AddRange takes an IEnumerable<T>, so you don't need to convert tripDetails into a List<TripDetails>, you can pass it directly, e.g.:

tripDetailsCollection.AddRange(tripDetails);

How do I set log4j level on the command line?

With Log4j2, this can be achieved using the following utility method added to your code.

private static void setLogLevel() {
  if (Boolean.getBoolean("log4j.debug")) {
    Configurator.setLevel(System.getProperty("log4j.logger"), Level.DEBUG);
  }
}

You need these imports

import org.apache.logging.log4j.Level;
import org.apache.logging.log4j.core.config.Configurator;

Now invoke the setLogLevel method in your main() or whereever appropriate and pass command line params -Dlog4j.logger=com.mypackage.Thingie and -Dlog4j.debug=true.

What does "implements" do on a class?

You should look into Java's interfaces. A quick Google search revealed this page, which looks pretty good.

I like to think of an interface as a "promise" of sorts: Any class that implements it has certain behavior that can be expected of it, and therefore you can put an instance of an implementing class into an interface-type reference.

A simple example is the java.lang.Comparable interface. By implementing all methods in this interface in your own class, you are claiming that your objects are "comparable" to one another, and can be partially ordered.

Implementing an interface requires two steps:

  1. Declaring that the interface is implemented in the class declaration
  2. Providing definitions for ALL methods that are part of the interface.

Interface java.lang.Comparable has just one method in it, public int compareTo(Object other). So you need to provide that method.

Here's an example. Given this class RationalNumber:

public class RationalNumber
{
    public int numerator;
    public int denominator;

    public RationalNumber(int num, int den)
    {
        this.numerator = num;
        this.denominator = den;
    }
}

(Note: It's generally bad practice in Java to have public fields, but I am intending this to be a very simple plain-old-data type so I don't care about public fields!)

If I want to be able to compare two RationalNumber instances (for sorting purposes, maybe?), I can do that by implementing the java.lang.Comparable interface. In order to do that, two things need to be done: provide a definition for compareTo and declare that the interface is implemented.

Here's how the fleshed-out class might look:

public class RationalNumber implements java.lang.Comparable
{
    public int numerator;
    public int denominator;

    public RationalNumber(int num, int den)
    {
        this.numerator = num;
        this.denominator = den;
    }

    public int compareTo(Object other)
    {
        if (other == null || !(other instanceof RationalNumber))
        {
            return -1; // Put this object before non-RationalNumber objects
        }

        RationalNumber r = (RationalNumber)other;

        // Do the calculations by cross-multiplying. This isn't really important to
        // the answer, but the point is we're comparing the two rational numbers.
        // And no, I don't care if it's mathematically inaccurate.

        int myTotal = this.numerator * other.denominator;
        int theirTotal = other.numerator * this.denominator;

        if (myTotal < theirTotal) return -1;
        if (myTotal > theirTotal) return 1;
        return 0;
    }
}

You're probably thinking, what was the point of all this? The answer is when you look at methods like this: sorting algorithms that just expect "some kind of comparable object". (Note the requirement that all objects must implement java.lang.Comparable!) That method can take lists of ANY kind of comparable objects, be they Strings or Integers or RationalNumbers.

NOTE: I'm using practices from Java 1.4 in this answer. java.lang.Comparable is now a generic interface, but I don't have time to explain generics.

Can't push to remote branch, cannot be resolved to branch

It's case-sensitive, just make sure created branch and push to branch both are in same capital.

Example:

git checkout -b "TASK-135-hello-world"

WRONG way of doing:

git push origin task-135-hello-world     #FATAL: task-135-hello-world cannot be resolved to branch

CORRECT way of doing:

git push origin TASK-135-hello-world

How to prevent scrollbar from repositioning web page?

I used some jquery to solve this

$('html').css({
    'overflow-y': 'hidden'
});

$(document).ready(function(){
  $(window).load(function() {
    $('html').css({
      'overflow-y': ''
    });
  });
});

Sending E-mail using C#

Use the namespace System.Net.Mail. Here is a link to the MSDN page

You can send emails using SmtpClient class.

I paraphrased the code sample, so checkout MSDNfor details.

MailMessage message = new MailMessage(
   "[email protected]",
   "[email protected]",
   "Subject goes here",
   "Body goes here");

SmtpClient client = new SmtpClient(server);
client.Send(message);

The best way to send many emails would be to put something like this in forloop and send away!

How to make an app's background image repeat

There is a property in the drawable xml to do it. android:tileMode="repeat"

See this site: http://androidforbeginners.blogspot.com/2010/06/how-to-tile-background-image-in-android.html

Running PowerShell as another user, and launching a script

I found this worked for me.

$username = 'user'
$password = 'password'

$securePassword = ConvertTo-SecureString $password -AsPlainText -Force
$credential = New-Object System.Management.Automation.PSCredential $username, $securePassword
Start-Process Notepad.exe -Credential $credential

Updated: changed to using single quotes to avoid special character issues noted by Paddy.

Python Write bytes to file

Write bytes and Create the file if not exists:

f = open('./put/your/path/here.png', 'wb')
f.write(data)
f.close()

wb means open the file in write binary mode.

Jenkins pipeline if else not working

your first try is using declarative pipelines, and the second working one is using scripted pipelines. you need to enclose steps in a steps declaration, and you can't use if as a top-level step in declarative, so you need to wrap it in a script step. here's a working declarative version:

pipeline {
    agent any

    stages {
        stage('test') {
            steps {
                sh 'echo hello'
            }
        }
        stage('test1') {
            steps {
                sh 'echo $TEST'
            }
        }
        stage('test3') {
            steps {
                script {
                    if (env.BRANCH_NAME == 'master') {
                        echo 'I only execute on the master branch'
                    } else {
                        echo 'I execute elsewhere'
                    }
                }
            }
        }
    }
}

you can simplify this and potentially avoid the if statement (as long as you don't need the else) by using "when". See "when directive" at https://jenkins.io/doc/book/pipeline/syntax/. you can also validate jenkinsfiles using the jenkins rest api. it's super sweet. have fun with declarative pipelines in jenkins!

Replace duplicate spaces with a single space in T-SQL

Please Find below code

select trim(string_agg(value,' ')) from STRING_SPLIT('  single    spaces   only  ',' ')
where value<>' '

This worked for me.. Hope this helps...

Spring Data and Native Query with pagination

This worked for me (I am using Postgres) in Groovy:

@RestResource(path="namespaceAndNameAndRawStateContainsMostRecentVersion", rel="namespaceAndNameAndRawStateContainsMostRecentVersion")
    @Query(nativeQuery=true,
            countQuery="""
            SELECT COUNT(1) 
            FROM 
            (
                SELECT
                ROW_NUMBER() OVER (
                    PARTITION BY name, provider_id, state
                    ORDER BY version DESC) version_partition,
                *
                FROM mydb.mytable
                WHERE
                (name ILIKE ('%' || :name || '%') OR (:name = '')) AND
                (namespace ILIKE ('%' || :namespace || '%') OR (:namespace = '')) AND
                (state = :state OR (:state = ''))
            ) t
            WHERE version_partition = 1
            """,
            value="""
            SELECT id, version, state, name, internal_name, namespace, provider_id, config, create_date, update_date 
            FROM 
            (
                SELECT 
                ROW_NUMBER() OVER (
                    PARTITION BY name, provider_id, state
                    ORDER BY version DESC) version_partition,
                *
                FROM mydb.mytable
                WHERE 
                (name ILIKE ('%' || :name || '%') OR (:name = '')) AND
                (namespace ILIKE ('%' || :namespace || '%') OR (:namespace = '')) AND
                (state = :state OR (:state = ''))       
            ) t            
            WHERE version_partition = 1             
            /*#{#pageable}*/
            """)
    public Page<Entity> findByNamespaceContainsAndNameContainsAndRawStateContainsMostRecentVersion(@Param("namespace")String namespace, @Param("name")String name, @Param("state")String state, Pageable pageable)

The key here was to use: /*#{#pageable}*/

It allows me to do sorting and pagination. You can test it by using something like this: http://localhost:8080/api/v1/entities/search/namespaceAndNameAndRawStateContainsMostRecentVersion?namespace=&name=&state=published&page=0&size=3&sort=name,desc

Watch out for this issue: Spring Pageable does not translate @Column name

Why do we have to specify FromBody and FromUri?

The default behavior is:

  1. If the parameter is a primitive type (int, bool, double, ...), Web API tries to get the value from the URI of the HTTP request.

  2. For complex types (your own object, for example: Person), Web API tries to read the value from the body of the HTTP request.

So, if you have:

  • a primitive type in the URI, or
  • a complex type in the body

...then you don't have to add any attributes (neither [FromBody] nor [FromUri]).

But, if you have a primitive type in the body, then you have to add [FromBody] in front of your primitive type parameter in your WebAPI controller method. (Because, by default, WebAPI is looking for primitive types in the URI of the HTTP request.)

Or, if you have a complex type in your URI, then you must add [FromUri]. (Because, by default, WebAPI is looking for complex types in the body of the HTTP request by default.)

Primitive types:

public class UsersController : ApiController
{
    // api/users
    public HttpResponseMessage Post([FromBody]int id)
    {

    }
    // api/users/id
    public HttpResponseMessage Post(int id)
    {

    }       
}

Complex types:

public class UsersController : ApiController
{       
    // api/users
    public HttpResponseMessage Post(User user)
    {

    }

    // api/users/user
    public HttpResponseMessage Post([FromUri]User user)
    {

    }       
}

This works as long as you send only one parameter in your HTTP request. When sending multiple, you need to create a custom model which has all your parameters like this:

public class MyModel
{
    public string MyProperty { get; set; }
    public string MyProperty2 { get; set; }
}

[Route("search")]
[HttpPost]
public async Task<dynamic> Search([FromBody] MyModel model)
{
    // model.MyProperty;
    // model.MyProperty2;
}

From Microsoft's documentation for parameter binding in ASP.NET Web API:

When a parameter has [FromBody], Web API uses the Content-Type header to select a formatter. In this example, the content type is "application/json" and the request body is a raw JSON string (not a JSON object). At most one parameter is allowed to read from the message body.

This should work:

public HttpResponseMessage Post([FromBody] string name) { ... }

This will not work:

// Caution: This won't work!    
public HttpResponseMessage Post([FromBody] int id, [FromBody] string name) { ... }

The reason for this rule is that the request body might be stored in a non-buffered stream that can only be read once.

No Creators, like default construct, exist): cannot deserialize from Object value (no delegate- or property-based Creator

I got here searching for this error:

No Creators, like default construct, exist): cannot deserialize from Object value (no delegate- or property-based Creator

Nothing to do with Retrofit but if you are using Jackson this error got solved by adding a default constructor to the class throwing the error. More here: https://www.baeldung.com/jackson-exception

How to calculate difference in hours (decimal) between two dates in SQL Server?

You are probably looking for the DATEDIFF function.

DATEDIFF ( datepart , startdate , enddate )

Where you code might look like this:

DATEDIFF ( hh , startdate , enddate )

How to run PyCharm in Ubuntu - "Run in Terminal" or "Run"?

As mentioned in the above answer, by updating the bashrc file you can run the pycharm.sh from anywhere on the linux terminal.

But if you love the icon and wants the Desktop shortcuts for the Pycharm on Ubuntu OS then follow the Below steps,

 Quick way to create Pycharm launcher. 
     1. Start Pycharm using the pycharm.sh cmd from anywhere on the terminal or start the pycharm.sh located under bin folder of the pycharm artifact.
     2. Once the Pycharm application loads, navigate to tools menu and select “Create Desktop Entry..”
     3. Check the box if you want the launcher for all users.
     4. If you Check the box i.e “Create entry for all users”, you will be asked for your password.
     5. A message should appear informing you that it was successful.
     6. Now Restart Pycharm application and you will find Pycharm in Unity dash and Application launcher.."

Does Django scale?

I have been using Django for over a year now, and am very impressed with how it manages to combine modularity, scalability and speed of development. Like with any technology, it comes with a learning curve. However, this learning curve is made a lot less steep by the excellent documentation from the Django community. Django has been able to handle everything I have thrown at it really well. It looks like it will be able to scale well into the future.

BidRodeo Penny Auctions is a moderately sized Django powered website. It is a very dynamic website and does handle a good number of page views a day.

Check if url contains string with JQuery

Use Window.location.href to take the url in javascript. it's a property that will tell you the current URL location of the browser. Setting the property to something different will redirect the page.

if (window.location.href.indexOf("?added-to-cart=555") > -1) {
    alert("found it");
}

How do I create a right click context menu in Java Swing?

There's a section on Bringing Up a Popup Menu in the How to Use Menus article of The Java Tutorials which explains how to use the JPopupMenu class.

The example code in the tutorial shows how to add MouseListeners to the components which should display a pop-up menu, and displays the menu accordingly.

(The method you describe is fairly similar to the way the tutorial presents the way to show a pop-up menu on a component.)

How can I do an asc and desc sort using underscore.js?

The Array prototype's reverse method modifies the array and returns a reference to it, which means you can do this:

var sortedAsc = _.sortBy(collection, 'propertyName');
var sortedDesc = _.sortBy(collection, 'propertyName').reverse();

Also, the underscore documentation reads:

In addition, the Array prototype's methods are proxied through the chained Underscore object, so you can slip a reverse or a push into your chain, and continue to modify the array.

which means you can also use .reverse() while chaining:

var sortedDescAndFiltered = _.chain(collection)
    .sortBy('propertyName')
    .reverse()
    .filter(_.property('isGood'))
    .value();

What is the significance of #pragma marks? Why do we need #pragma marks?

#pragma mark - NSSecureCoding

The main purpose of "pragma" is for developer reference.enter image description here

You can easily find a method/Function in a vast thousands of coding lines.

Xcode 11+:

Marker Line in Top

// MARK: - Properties

Marker Line in Top and Bottom

// MARK: - Properties - 

Marker Line only in bottom

// MARK: Properties -

Error creating bean with name 'entityManagerFactory' defined in class path resource : Invocation of init method failed

I would start by adding the following dependency:

<dependency>
    <groupId>org.hibernate</groupId>
    <artifactId>hibernate-core</artifactId>
    <version>4.1.4.Final</version>
</dependency>

and

<dependency>
    <groupId>org.hibernate</groupId>
    <artifactId>hibernate-entitymanager</artifactId>
    <version>5.2.3.Final</version>
</dependency>

UPDATE: Or simply add the following dependency.

<dependency>
    <groupId>javax.xml.bind</groupId>
    <artifactId>jaxb-api</artifactId>
    <version>2.3.0</version>
</dependency>

How do you configure tomcat to bind to a single ip address (localhost) instead of all addresses?

it's well documented here:

https://cwiki.apache.org/confluence/display/TOMCAT/Connectors#Connectors-Q6

How do I bind to a specific ip address? - "Each Connector element allows an address property. See the HTTP Connector docs or the AJP Connector docs". And HTTP Connectors docs:

http://tomcat.apache.org/tomcat-7.0-doc/config/http.html

Standard Implementation -> address

"For servers with more than one IP address, this attribute specifies which address will be used for listening on the specified port. By default, this port will be used on all IP addresses associated with the server."

Multi-dimensional arraylist or list in C#?

you just make a list of lists like so:

List<List<string>> results = new List<List<string>>();

and then it's just a matter of using the functionality you want

results.Add(new List<string>()); //adds a new list to your list of lists
results[0].Add("this is a string"); //adds a string to the first list
results[0][0]; //gets the first string in your first list

Recursive Lock (Mutex) vs Non-Recursive Lock (Mutex)

What are non-recursive mutexes good for?

They are absolutely good when you have to make sure the mutex is unlocked before doing something. This is because pthread_mutex_unlock can guarantee that the mutex is unlocked only if it is non-recursive.

pthread_mutex_t      g_mutex;

void foo()
{
    pthread_mutex_lock(&g_mutex);
    // Do something.
    pthread_mutex_unlock(&g_mutex);

    bar();
}

If g_mutex is non-recursive, the code above is guaranteed to call bar() with the mutex unlocked.

Thus eliminating the possibility of a deadlock in case bar() happens to be an unknown external function which may well do something that may result in another thread trying to acquire the same mutex. Such scenarios are not uncommon in applications built on thread pools, and in distributed applications, where an interprocess call may spawn a new thread without the client programmer even realising that. In all such scenarios it's best to invoke the said external functions only after the lock is released.

If g_mutex was recursive, there would be simply no way to make sure it is unlocked before making a call.

How can I change the font size using seaborn FacetGrid?

You can scale up the fonts in your call to sns.set().

import numpy as np
import matplotlib.pyplot as plt
import seaborn as sns
x = np.random.normal(size=37)
y = np.random.lognormal(size=37)

# defaults
sns.set()
fig, ax = plt.subplots()
ax.plot(x, y, marker='s', linestyle='none', label='small')
ax.legend(loc='upper left', bbox_to_anchor=(0, 1.1))

enter image description here

sns.set(font_scale=5)  # crazy big
fig, ax = plt.subplots()
ax.plot(x, y, marker='s', linestyle='none', label='big')
ax.legend(loc='upper left', bbox_to_anchor=(0, 1.3))

enter image description here

Oracle JDBC ojdbc6 Jar as a Maven Dependency

Oracle JDBC drivers and other companion Jars are available on Central Maven. We suggest to use the official supported Oracle JDBC versions from 11.2.0.4, 12.2.0.2, 18.3.0.0, 19.3.0.0, 19.6.0.0, and 19.7.0.0. These are available on Central Maven Repository. Refer to Maven Central Guide for more details.

It is recommended to use the latest version. Check out FAQ for JDK compatibility.

Python style - line continuation with strings?

Just pointing out that it is use of parentheses that invokes auto-concatenation. That's fine if you happen to already be using them in the statement. Otherwise, I would just use '\' rather than inserting parentheses (which is what most IDEs do for you automatically). The indent should align the string continuation so it is PEP8 compliant. E.g.:

my_string = "The quick brown dog " \
            "jumped over the lazy fox"

How to move all HTML element children to another parent using JavaScript?

DEMO

Basically, you want to loop through each direct descendent of the old-parent node, and move it to the new parent. Any children of a direct descendent will get moved with it.

var newParent = document.getElementById('new-parent');
var oldParent = document.getElementById('old-parent');

while (oldParent.childNodes.length > 0) {
    newParent.appendChild(oldParent.childNodes[0]);
}

How to get a unique computer identifier in Java (like disk ID or motherboard ID)?

It is common to use the MAC address is associated with the network card.

The address is available in Java 6 through through the following API:

Java 6 Docs for Hardware Address

I haven't used it in Java, but for other network identification applications it has been helpful.

How to restart ADB manually from Android Studio

I faced same issue just fallowed some min steps in Android studio:

Manually fallowing steps in android studio

  1. Goto Command promt and in Command promt fallow a android SDK file path "android sdk>platform-tools>" adb kill-server press enter
  2. adb start-server press enter

-------------------------------------------------OR-----------------------------------------------------------------------

  1. Open Command promt and got android sdk file path adb kill-server && adb start-server

Difference between save and saveAndFlush in Spring data jpa

Depending on the hibernate flush mode that you are using (AUTO is the default) save may or may not write your changes to the DB straight away. When you call saveAndFlush you are enforcing the synchronization of your model state with the DB.

If you use flush mode AUTO and you are using your application to first save and then select the data again, you will not see a difference in bahvior between save() and saveAndFlush() because the select triggers a flush first. See the documention.

What is the location of mysql client ".my.cnf" in XAMPP for Windows?

Create it yourself in folder c:\xampp\mysql.

The type arguments cannot be inferred from the usage. Try specifying the type arguments explicitly

You are referring to the type rather than the instance. Make 'Model' lowercase in the example in your second and fourth code samples.

Model.GetHtmlAttributes

should be

model.GetHtmlAttributes

How to get UTC timestamp in Ruby?

Time.utc(2010, 05, 17)

git: updates were rejected because the remote contains work that you do not have locally

you can use

git pull --rebase <your_reponame> <your_branch>

this will help incase you have some changes not yet registered on your local repo. especially README.md

SQL Server - inner join when updating

This should do it:

UPDATE ProductReviews
SET    ProductReviews.status = '0'
FROM   ProductReviews
       INNER JOIN products
         ON ProductReviews.pid = products.id
WHERE  ProductReviews.id = '17190'
       AND products.shopkeeper = '89137'

How do I send an HTML Form in an Email .. not just MAILTO

> 2020 Answer = The Easy Way using Google Apps Script (5 Mins)

We had a similar challenge to solve yesterday, and we solved it using a Google Apps Script!

Send Email From an HTML Form Without a Backend (Server) via Google!

The solution takes 5 mins to implement and I've documented with step-by-step instructions: https://github.com/nelsonic/html-form-send-email-via-google-script-without-server

Brief Overview

A. Using the sample script, deploy a Google App Script

Deploy the sample script as a Google Spreadsheet APP Script: google-script-just-email.js

3-script-editor-showing-script

remember to set the TO_ADDRESS in the script to where ever you want the emails to be sent.
and copy the APP URL so you can use it in the next step when you publish the script.

B. Create your HTML Form and Set the action to the App URL

Using the sample html file: index.html create a basic form.

7-html-form

remember to paste your APP URL into the form action in the HTML form.

C. Test the HTML Form in your Browser

Open the HTML Form in your Browser, Input some data & submit it!

html form

Submit the form. You should see a confirmation that it was sent: form sent

Open the inbox for the email address you set (above)

email received

Done.

Everything about this is customisable, you can easily style/theme the form with your favourite CSS Library and Store the submitted data in a Google Spreadsheet for quick analysis.
The complete instructions are available on GitHub:
https://github.com/nelsonic/html-form-send-email-via-google-script-without-server

Set field value with reflection

The method below sets a field on your object even if the field is in a superclass

/**
 * Sets a field value on a given object
 *
 * @param targetObject the object to set the field value on
 * @param fieldName    exact name of the field
 * @param fieldValue   value to set on the field
 * @return true if the value was successfully set, false otherwise
 */
public static boolean setField(Object targetObject, String fieldName, Object fieldValue) {
    Field field;
    try {
        field = targetObject.getClass().getDeclaredField(fieldName);
    } catch (NoSuchFieldException e) {
        field = null;
    }
    Class superClass = targetObject.getClass().getSuperclass();
    while (field == null && superClass != null) {
        try {
            field = superClass.getDeclaredField(fieldName);
        } catch (NoSuchFieldException e) {
            superClass = superClass.getSuperclass();
        }
    }
    if (field == null) {
        return false;
    }
    field.setAccessible(true);
    try {
        field.set(targetObject, fieldValue);
        return true;
    } catch (IllegalAccessException e) {
        return false;
    }
}

What does PHP keyword 'var' do?

In PHP7.3 still working...

https://www.php.net/manual/en/language.oop5.visibility.php

If declared using var, the property will be defined as public.

Unity 2d jumping script

Use Addforce() method of a rigidbody compenent, make sure rigidbody is attached to the object and gravity is enabled, something like this

gameObj.rigidbody2D.AddForce(Vector3.up * 10 * Time.deltaTime); or 
gameObj.rigidbody2D.AddForce(Vector3.up * 1000); 

See which combination and what values matches your requirement and use accordingly. Hope it helps

Convert object to JSON in Android

download the library Gradle:

compile 'com.google.code.gson:gson:2.8.2'

To use the library in a method.

Gson gson = new Gson();

//transform a java object to json
System.out.println("json =" + gson.toJson(Object.class).toString());

//Transform a json to java object
String json = string_json;
List<Object> lstObject = gson.fromJson(json_ string, Object.class);

No newline at end of file

The core problem is what you define line and whether end-on-line character sequence is part of the line or not. UNIX-based editors (such as VIM) or tools (such as Git) use EOL character sequence as line terminator, therefore it's a part of the line. It's similar to use of semicolon (;) in C and Pascal. In C semicolon terminates statements, in Pascal it separates them.

How do I include negative decimal numbers in this regular expression?

UPDATED(13/08/2014): This is the best code for positive and negative numbers =)

(^-?0\.[0-9]*[1-9]+[0-9]*$)|(^-?[1-9]+[0-9]*((\.[0-9]*[1-9]+[0-9]*$)|(\.[0-9]+)))|(^-?[1-9]+[0-9]*$)|(^0$){1}

I tried with this numbers and works fine:

-1234454.3435
-98.99
-12.9
-12.34
-10.001
-3
-0.001
-000
-0.00
0
0.00
00000001.1
0.01
1201.0000001
1234454.3435
7638.98701

How to parse json string in Android?

Below is the link which guide in parsing JSON string in android.

http://www.ibm.com/developerworks/xml/library/x-andbene1/?S_TACT=105AGY82&S_CMP=MAVE

Also according to your json string code snippet must be something like this:-

JSONObject mainObject = new JSONObject(yourstring);

JSONObject universityObject = mainObject.getJSONObject("university");
JSONString name = universityObject.getString("name");  
JSONString url = universityObject.getString("url");

Following is the API reference for JSOnObject: https://developer.android.com/reference/org/json/JSONObject.html#getString(java.lang.String)

Same for other object.

What is the use of hashCode in Java?

The value returned by hashCode() is the object's hash code, which is the object's memory address in hexadecimal.

By definition, if two objects are equal, their hash code must also be equal. If you override the equals() method, you change the way two objects are equated and Object's implementation of hashCode() is no longer valid. Therefore, if you override the equals() method, you must also override the hashCode() method as well.

This answer is from the java SE 8 official tutorial documentation

Why is the default value of the string type null instead of an empty string?

Nullable types did not come in until 2.0.

If nullable types had been made in the beginning of the language then string would have been non-nullable and string? would have been nullable. But they could not do this du to backward compatibility.

A lot of people talk about ref-type or not ref type, but string is an out of the ordinary class and solutions would have been found to make it possible.

Why boolean in Java takes only true or false? Why not 1 or 0 also?

Because the people who created Java wanted boolean to mean unambiguously true or false, not 1 or 0.

There's no consensus among languages about how 1 and 0 convert to booleans. C uses any nonzero value to mean true and 0 to mean false, but some UNIX shells do the opposite. Using ints weakens type-checking, because the compiler can't guard against cases where the int value passed in isn't something that should be used in a boolean context.

How to play video with AVPlayerViewController (AVKit) in Swift

Objective c

This only works in Xcode 7

Go to .h file and import AVKit/AVKit.h and AVFoundation/AVFoundation.h. Then go .m file and add this code:

NSURL *url=[[NSBundle mainBundle]URLForResource:@"arreg" withExtension:@"mp4"];
AVPlayer *video=[AVPlayer playerWithURL:url];
AVPlayerViewController *controller=[[AVPlayerViewController alloc]init];
controller.player=video;
[self.view addSubview:controller.view];
controller.view.frame=self.view.frame;
[self addChildViewController:controller];
[video play];

Get encoding of a file in Windows

Similar to the solution listed above with Notepad, you can also open the file in Visual Studio, if you're using that. In Visual Studio, you can select "File > Advanced Save Options..."

The "Encoding:" combo box will tell you specifically which encoding is currently being used for the file. It has a lot more text encodings listed in there than Notepad does, so it's useful when dealing with various files from around the world and whatever else.

Just like Notepad, you can also change the encoding from the list of options there, and then saving the file after hitting "OK". You can also select the encoding you want through the "Save with Encoding..." option in the Save As dialog (by clicking the arrow next to the Save button).

How to avoid "cannot load such file -- utils/popen" from homebrew on OSX

In my case I just needed to remove Homebrew's executable using:

sudo rm -f `which brew`

Then reinstall Homebrew:

ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)"

What is /var/www/html?

In the most shared hosts you can't set it.

On a VPS or dedicated server, you can set it, but everything has its price.

On shared hosts, in general you receive a Linux account, something such as /home/(your username)/, and the equivalent of /var/www/html turns to /home/(your username)/public_html/ (or something similar, such as /home/(your username)/www)

If you're accessing your account via FTP, you automatically has accessing the your */home/(your username)/ folder, just find the www or public_html and put your site in it.

If you're using absolute path in the code, bad news, you need to refactor it to use relative paths in the code, at least in a shared host.

Javascript - check array for value

This should do it:

for (var i = 0; i < bank_holidays.length; i++) {
    if (bank_holidays[i] === '06/04/2012') {
        alert('LOL');
    }
}

jsFiddle

How to receive JSON as an MVC 5 action method parameter

Unfortunately, Dictionary has problems with Model Binding in MVC. Read the full story here. Instead, create a custom model binder to get the Dictionary as a parameter for the controller action.

To solve your requirement, here is the working solution -

First create your ViewModels in following way. PersonModel can have list of RoleModels.

public class PersonModel
{
    public List<RoleModel> Roles { get; set; }
    public string Name { get; set; }
}

public class RoleModel
{
    public string RoleName { get; set;}
    public string Description { get; set;}
}

Then have a index action which will be serving basic index view -

public ActionResult Index()
{
    return View();
}

Index view will be having following JQuery AJAX POST operation -

<script src="~/Scripts/jquery-1.10.2.min.js"></script>
<script>
    $(function () {
        $('#click1').click(function (e) {

            var jsonObject = {
                "Name" : "Rami",
                "Roles": [{ "RoleName": "Admin", "Description" : "Admin Role"}, { "RoleName": "User", "Description" : "User Role"}]
            };

            $.ajax({
                url: "@Url.Action("AddUser")",
                type: "POST",
                data: JSON.stringify(jsonObject),
                contentType: "application/json; charset=utf-8",
                dataType: "json",
                error: function (response) {
                    alert(response.responseText);
            },
                success: function (response) {
                    alert(response);
                }
            });

        });
    });
</script>

<input type="button" value="click1" id="click1" />

Index action posts to AddUser action -

[HttpPost]
public ActionResult AddUser(PersonModel model)
{
    if (model != null)
    {
        return Json("Success");
    }
    else
    {
        return Json("An Error Has occoured");
    }
}

So now when the post happens you can get all the posted data in the model parameter of action.

Update:

For asp.net core, to get JSON data as your action parameter you should add the [FromBody] attribute before your param name in your controller action. Note: if you're using ASP.NET Core 2.1, you can also use the [ApiController] attribute to automatically infer the [FromBody] binding source for your complex action method parameters. (Doc)

enter image description here

CASE in WHERE, SQL Server

(something else) should be a.Country

if Country is nullable then make(something else) be a.Country OR a.Country is NULL

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

This was what I did to solve my related problem

interface Map {
  [key: string]: string | undefined
}

const HUMAN_MAP: Map = {
  draft: "Draft",
}

export const human = (str: string) => HUMAN_MAP[str] || str

Facebook Access Token for Pages

See here if you want to grant a Facebook App permanent access to a page (even when you / the app owner are logged out):

http://developers.facebook.com/docs/opengraph/using-app-tokens/

"An App Access Token does not expire unless you refresh the application secret through your app settings."

What is the difference between print and puts?

If you would like to output array within string using puts, you will get the same result as if you were using print:

puts "#{[0, 1, nil]}":
[0, 1, nil]

But if not withing a quoted string then yes. The only difference is between new line when we use puts.

Maven Jacoco Configuration - Exclude classes/packages from report not working

you can configure the coverage exclusion in the sonar properties, outside of the configuration of the jacoco plugin:

...
<properties>
    ....
    <sonar.exclusions>
        **/generated/**/*,
        **/model/**/*
    </sonar.exclusions>
    <sonar.test.exclusions>
        src/test/**/*
    </sonar.test.exclusions>
    ....
    <sonar.java.coveragePlugin>jacoco</sonar.java.coveragePlugin>
    <sonar.jacoco.reportPath>${project.basedir}/../target/jacoco.exec</sonar.jacoco.reportPath>
    <sonar.coverage.exclusions>
        **/generated/**/*,
        **/model/**/*
    </sonar.coverage.exclusions>
    <jacoco.version>0.7.5.201505241946</jacoco.version>
    ....
</properties>
....

and remember to remove the exclusion settings from the plugin

Java System.out.print formatting

Are you sure that you want "055" as opposed to "55"? Some programs interpret a leading zero as meaning octal, so that it would read 055 as (decimal) 45 instead of (decimal) 55.

That should just mean dropping the '0' (zero-fill) flag.

e.g., change System.out.printf("%03d ", x); to the simpler System.out.printf("%3d ", x);

OpenCV Error: (-215)size.width>0 && size.height>0 in function imshow

That error also shows when the video has played fine and the script will finish but that error always throws because the imshow() will get empty frames after all frames have been consumed.

That is especially the case if you are playing a short (few sec) video file and you don't notice that the video actually played on the background (behind your code editor) and after that the script ends with that error.

How to create a sticky navigation bar that becomes fixed to the top after scrolling

I have found this simple javascript snippet very useful.

$(document).ready(function()
{
    var navbar = $('#navbar');

    navbar.after('<div id="more-div" style="height: ' + navbar.outerHeight(true) + 'px" class="hidden"></div>');
    var afternavbar = $('#more-div');

    var abovenavbar = $('#above-navbar');

    $(window).on('scroll', function()
    {
        if ($(window).scrollTop() > abovenavbar.height())
        {
            navbar.addClass('navbar-fixed-top');
            afternavbar.removeClass('hidden');
        }
        else
        {
            navbar.removeClass('navbar-fixed-top');
            afternavbar.addClass('hidden');
        }
    });
});

How to compare two columns in Excel and if match, then copy the cell next to it

It might be easier with vlookup. Try this:

=IFERROR(VLOOKUP(D2,G:H,2,0),"")

The IFERROR() is for no matches, so that it throws "" in such cases.

VLOOKUP's first parameter is the value to 'look for' in the reference table, which is column G and H.

VLOOKUP will thus look for D2 in column G and return the value in the column index 2 (column G has column index 1, H will have column index 2), meaning that the value from column H will be returned.

The last parameter is 0 (or equivalently FALSE) to mean an exact match. That's what you need as opposed to approximate match.

Hibernate vs JPA vs JDO - pros and cons of each?

I made a sample WebApp in May 2012 that uses JDO 3.0 & DataNucleus 3.0 - take a look how clean it is: https://github.com/TorbenVesterager/BadAssWebApp

Okay maybe it's a little bit too clean, because I use the POJOs both for the database and the JSON client, but it's fun :)

PS: Contains a few SuppressWarnings annotations (developed in IntelliJ 11)

XAMPP PORT 80 is Busy / EasyPHP error in Apache configuration file:

This problem is because port 80 is used by some other application. Try to reconfigure port.

Create a file if one doesn't exist - C

If fptr is NULL, then you don't have an open file. Therefore, you can't freopen it, you should just fopen it.

FILE *fptr;
fptr = fopen("scores.dat", "rb+");
if(fptr == NULL) //if file does not exist, create it
{
    fptr = fopen("scores.dat", "wb");
}

note: Since the behavior of your program varies depending on whether the file is opened in read or write modes, you most probably also need to keep a variable indicating which is the case.

A complete example

int main()
{
    FILE *fptr;
    char there_was_error = 0;
    char opened_in_read  = 1;
    fptr = fopen("scores.dat", "rb+");
    if(fptr == NULL) //if file does not exist, create it
    {
        opened_in_read = 0;
        fptr = fopen("scores.dat", "wb");
        if (fptr == NULL)
            there_was_error = 1;
    }
    if (there_was_error)
    {
        printf("Disc full or no permission\n");
        return EXIT_FAILURE;
    }
    if (opened_in_read)
        printf("The file is opened in read mode."
               " Let's read some cached data\n");
    else
        printf("The file is opened in write mode."
               " Let's do some processing and cache the results\n");
    return EXIT_SUCCESS;
}

How to change pivot table data source in Excel?

for MS excel 2000 office version, click on the pivot table you will find a tab above the ribon, called Pivottable tool - click on that You can change data source from Data tab

Python 3 Building an array of bytes

I think Scapy is what are you looking for.

http://www.secdev.org/projects/scapy/

you can build and send frames (packets) with it

Get file name from a file location in Java

From Apache Commons IO FileNameUtils

String fileName = FilenameUtils.getName(stringNameWithPath);

Very Long If Statement in Python

Here is the example directly from PEP 8 on limiting line length:

class Rectangle(Blob):

    def __init__(self, width, height,
                 color='black', emphasis=None, highlight=0):
        if (width == 0 and height == 0 and
                color == 'red' and emphasis == 'strong' or
                highlight > 100):
            raise ValueError("sorry, you lose")
        if width == 0 and height == 0 and (color == 'red' or
                                           emphasis is None):
            raise ValueError("I don't think so -- values are %s, %s" %
                             (width, height))
        Blob.__init__(self, width, height,
                      color, emphasis, highlight)

How do I loop through children objects in javascript?

if tableFields is an array , you can loop through elements as following :

for (item in tableFields); {
     console.log(tableFields[item]);
}

by the way i saw a logical error in you'r code.just remove ; from end of for loop

right here :

for (item in tableFields); { .

this will cause you'r loop to do just nothing.and the following line will be executed only once :

// Do stuff

React Native Change Default iOS Simulator Device

Specify a simulator using the --simulator flag.

These are the available devices for iOS 14.0 onwards:

npx react-native run-ios --simulator="iPhone 8"
npx react-native run-ios --simulator="iPhone 8 Plus"
npx react-native run-ios --simulator="iPhone 11"
npx react-native run-ios --simulator="iPhone 11 Pro"
npx react-native run-ios --simulator="iPhone 11 Pro Max"
npx react-native run-ios --simulator="iPhone SE (2nd generation)"
npx react-native run-ios --simulator="iPhone 12 mini"
npx react-native run-ios --simulator="iPhone 12"
npx react-native run-ios --simulator="iPhone 12 Pro"
npx react-native run-ios --simulator="iPhone 12 Pro Max"
npx react-native run-ios --simulator="iPod touch (7th generation)"
npx react-native run-ios --simulator="iPad Pro (9.7-inch)"
npx react-native run-ios --simulator="iPad Pro (11-inch) (2nd generation)"
npx react-native run-ios --simulator="iPad Pro (12.9-inch) (4th generation)"
npx react-native run-ios --simulator="iPad (8th generation)"
npx react-native run-ios --simulator="iPad Air (4th generation)"

List all available iOS devices:

xcrun simctl list devices

There is currently no way to set a default.

React Native Docs: Running On Simulator

How do browser cookie domains work?

I tested all the cases in the latest Chrome, Firefox, Safari in 2019.

Response to Added:

  • Will a cookie for .example.com be available for www.example.com? YES
  • Will a cookie for .example.com be available for example.com? YES
  • Will a cookie for example.com be available for www.example.com? NO, Domain without wildcard only matches itself.
  • Will a cookie for example.com be available for anotherexample.com? NO
  • Will www.example.com be able to set cookie for example.com? NO, it will be able to set cookie for '.example.com', but not 'example.com'.
  • Will www.example.com be able to set cookie for www2.example.com? NO. But it can set cookie for .example.com, which www2.example.com can access.
  • Will www.example.com be able to set cookie for .com? NO

How to run crontab job every week on Sunday

I think you would like this interactive website, which often helps me build complex Crontab directives: https://crontab.guru/

afxwin.h file is missing in VC++ Express Edition

I see the question is about Express Edition, but this topic is easy to pop up in Google Search, and doesn't have a solution for other editions.

So. If you run into this problem with any VS Edition except Express, you can rerun installation and include MFC files.

How to take backup of a single table in a MySQL database?

You can use this code:

This example takes a backup of sugarcrm database and dumps the output to sugarcrm.sql

# mysqldump -u root -ptmppassword sugarcrm > sugarcrm.sql

# mysqldump -u root -p[root_password] [database_name] > dumpfilename.sql

The sugarcrm.sql will contain drop table, create table and insert command for all the tables in the sugarcrm database. Following is a partial output of sugarcrm.sql, showing the dump information of accounts_contacts table:

--

-- Table structure for table accounts_contacts

DROP TABLE IF EXISTS `accounts_contacts`;
SET @saved_cs_client = @@character_set_client;
SET character_set_client = utf8;
CREATE TABLE `accounts_contacts` (
`id` varchar(36) NOT NULL,
`contact_id` varchar(36) default NULL,
`account_id` varchar(36) default NULL,
`date_modified` datetime default NULL,
`deleted` tinyint(1) NOT NULL default '0',
PRIMARY KEY (`id`),
KEY `idx_account_contact` (`account_id`,`contact_id`),
KEY `idx_contid_del_accid` (`contact_id`,`deleted`,`account_id`)
) ENGINE=MyISAM DEFAULT CHARSET=utf8;
SET character_set_client = @saved_cs_client;

--

How to Solve Max Connection Pool Error

Check against any long running queries in your database.

Increasing your pool size will only make your webapp live a little longer (and probably get a lot slower)

You can use sql server profiler and filter on duration / reads to see which querys need optimization.

I also see you're probably keeping a global connection?

blnMainConnectionIsCreatedLocal

Let .net do the pooling for you and open / close your connection with a using statement.

Suggestions:

  1. Always open and close a connection like this, so .net can manage your connections and you won't run out of connections:

        using (SqlConnection conn = new SqlConnection(connectionString))
        {
         conn.Open();
         // do some stuff
        } //conn disposed
    
  2. As I mentioned, check your query with sql server profiler and see if you can optimize it. Having a slow query with many requests in a web app can give these timeouts too.

An established connection was aborted by the software in your host machine

I was having this problem. Things I tried:

  1. Restart Eclipse
  2. Restart Eclipse & Kill adb as mentioned here.
  3. Restart Machine & Open Eclipse

This is what worked for me

  1. Powered off (pulled plug) my android device, Restart Machine, Power on android device.

Hope this helps someone!

SQL query for extracting year from a date

This worked for me:

SELECT EXTRACT(YEAR FROM ASOFDATE) FROM PSASOFDATE;

Adding link a href to an element using css

You don't need CSS for this.

     <img src="abc"/>

now with link:

     <a href="#myLink"><img src="abc"/></a>

Or with jquery, later on, you can use the wrap property, see these questions answer:

how to add a link to an image using jquery?

How do I solve the INSTALL_FAILED_DEXOPT error?

classes.dex does not make it to the final .apk. Running gradlew --offline clean && gradlew --offline assembleDebug fixed things for me every time. From that point you can start launching the app from Android Studio again.

EDIT: Before what I said above go to Task Manager and kill all cmd.exe and conhost.exe processes (or just the one in which aapt got stuck). Otherwise aapt would crash from now on when launched from command line with the infamous error -1073741819.

C++ catching all exceptions

it is possible to do this by writing:

try
{
  //.......
}
catch(...) // <<- catch all
{
  //.......
}

But there is a very not noticeable risk here: you can not find the exact type of error that has been thrown in the try block, so use this kind of catch when you are sure that no matter what the type of exception is, the program must persist in the way defined in the catch block.

str.startswith with a list of strings to test for

You can also use any(), map() like so:

if any(map(l.startswith, x)):
    pass # Do something

Or alternatively, using a generator expression:

if any(l.startswith(s) for s in x)
    pass # Do something

How can I know if a branch has been already merged into master?

I use git for-each-ref to get a list of branches that are either merged or not merged into a given remote branch (e.g. origin/integration)

Iterate over all refs that match <pattern> and show them according to the given <format>, after sorting them according to the given set of <key>.

Note: replace origin/integration with integration if you tend to use git pull as opposed to git fetch.

List of local branches merged into the remote origin/integration branch

git for-each-ref --merged=origin/integration --format="%(refname:short)" refs/heads/
#                ^                           ^                           ^
#                A                           B                           C
branch1
branch2
branch3
branch4

A: Take only the branches merged into the remote origin/integration branch
B: Print the branch name
C: Only look at heads refs (i.e. branches)

List of local branches NOT merged into the remote origin/integration branch

git for-each-ref --no-merged=origin/integration --format="%(committerdate:short) %(refname:short)" --sort=committerdate refs/heads
#                ^                              ^                                                  ^                    ^
#                A                              B                                                  C                    D
2020-01-14 branch10
2020-01-16 branch11
2020-01-17 branch12
2020-01-30 branch13

A: Take only the branches NOT merged into the remote origin/integration branch
B: Print the branch name along with the last commit date
C: Sort output by commit date
D: Only look at heads refs (i.e. branches)

How to emit an event from parent to child?

As far as I know, there are 2 standard ways you can do that.

1. @Input

Whenever the data in the parent changes, the child gets notified about this in the ngOnChanges method. The child can act on it. This is the standard way of interacting with a child.

Parent-Component
public inputToChild: Object;

Parent-HTML
<child [data]="inputToChild"> </child>       

Child-Component: @Input() data;

ngOnChanges(changes: { [property: string]: SimpleChange }){
   // Extract changes to the input property by its name
   let change: SimpleChange = changes['data']; 
// Whenever the data in the parent changes, this method gets triggered. You 
// can act on the changes here. You will have both the previous value and the 
// current value here.
}
  1. Shared service concept

Creating a service and using an observable in the shared service. The child subscribes to it and whenever there is a change, the child will be notified. This is also a popular method. When you want to send something other than the data you pass as the input, this can be used.

SharedService
subject: Subject<Object>;

Parent-Component
constructor(sharedService: SharedService)
this.sharedService.subject.next(data);

Child-Component
constructor(sharedService: SharedService)
this.sharedService.subject.subscribe((data)=>{

// Whenever the parent emits using the next method, you can receive the data 
in here and act on it.})

Set "Homepage" in Asp.Net MVC

public class RouteConfig
{
    public static void RegisterRoutes(RouteCollection routes)
    {
        routes.IgnoreRoute("{resource}.axd/{*pathInfo}");

        routes.MapRoute(
            name: "Default",
            url: "{controller}/{action}/{id}",               
            defaults: new { controller = "Your Controller", action = "Your Action", id = UrlParameter.Optional }
        );
    }
}

REST API Token-based Authentication

Let me seperate up everything and solve approach each problem in isolation:

Authentication

For authentication, baseauth has the advantage that it is a mature solution on the protocol level. This means a lot of "might crop up later" problems are already solved for you. For example, with BaseAuth, user agents know the password is a password so they don't cache it.

Auth server load

If you dispense a token to the user instead of caching the authentication on your server, you are still doing the same thing: Caching authentication information. The only difference is that you are turning the responsibility for the caching to the user. This seems like unnecessary labor for the user with no gains, so I recommend to handle this transparently on your server as you suggested.

Transmission Security

If can use an SSL connection, that's all there is to it, the connection is secure*. To prevent accidental multiple execution, you can filter multiple urls or ask users to include a random component ("nonce") in the URL.

url = username:[email protected]/api/call/nonce

If that is not possible, and the transmitted information is not secret, I recommend securing the request with a hash, as you suggested in the token approach. Since the hash provides the security, you could instruct your users to provide the hash as the baseauth password. For improved robustness, I recommend using a random string instead of the timestamp as a "nonce" to prevent replay attacks (two legit requests could be made during the same second). Instead of providing seperate "shared secret" and "api key" fields, you can simply use the api key as shared secret, and then use a salt that doesn't change to prevent rainbow table attacks. The username field seems like a good place to put the nonce too, since it is part of the auth. So now you have a clean call like this:

nonce = generate_secure_password(length: 16);
one_time_key = nonce + '-' + sha1(nonce+salt+shared_key);
url = username:[email protected]/api/call

It is true that this is a bit laborious. This is because you aren't using a protocol level solution (like SSL). So it might be a good idea to provide some kind of SDK to users so at least they don't have to go through it themselves. If you need to do it this way, I find the security level appropriate (just-right-kill).

Secure secret storage

It depends who you are trying to thwart. If you are preventing people with access to the user's phone from using your REST service in the user's name, then it would be a good idea to find some kind of keyring API on the target OS and have the SDK (or the implementor) store the key there. If that's not possible, you can at least make it a bit harder to get the secret by encrypting it, and storing the encrypted data and the encryption key in seperate places.

If you are trying to keep other software vendors from getting your API key to prevent the development of alternate clients, only the encrypt-and-store-seperately approach almost works. This is whitebox crypto, and to date, no one has come up with a truly secure solution to problems of this class. The least you can do is still issue a single key for each user so you can ban abused keys.

(*) EDIT: SSL connections should no longer be considered secure without taking additional steps to verify them.

MVC 4 client side validation not working

If you use jquery.validate.js and jquery.validate.unobtrusive.js for validating on client side, you should remember that you have to register any validation attribute of any DOM element on your request. Therefor you can use this code:

$.validator.unobtrusive.parse('your main element on layout');

to register all validation attributes. You can call this method on (for example) : $(document).ajaxSuccess() or $(document).ready() to register all of them and your validation can be occurred successfully instead of registering all js files on cshtml files.

jQuery vs. javascript?

Jquery like any other good JavaScript frameworks supplies you with functionality independent of browser platform wrapping all the intricacies, which you may not care about or don't want to care about.

I think using a framework is better instead of using pure JavaScript and doing all the stuff from scratch, unless you usage is very limited.

I definitely recommend JQuery!

Thanks

Select and display only duplicate records in MySQL

SELECT * FROM `table` t1 join `table` t2 WHERE (t1.name=t2.name) && (t1.id!=t2.id)

Progress during large file copy (Copy-Item & Write-Progress?)

I amended the code from stej (which was great, just what i needed!) to use larger buffer, [long] for larger files and used System.Diagnostics.Stopwatch class to track elapsed time and estimate time remaining.

Also added reporting of transfer rate during transfer and outputting overall elapsed time and overall transfer rate.

Using 4MB (4096*1024 bytes) buffer to get better than Win7 native throughput copying from NAS to USB stick on laptop over wifi.

On To-Do list:

  • add error handling (catch)
  • handle get-childitem file list as input
  • nested progress bars when copying multiple files (file x of y, % if total data copied etc)
  • input parameter for buffer size

Feel free to use/improve :-)

function Copy-File {
param( [string]$from, [string]$to)
$ffile = [io.file]::OpenRead($from)
$tofile = [io.file]::OpenWrite($to)
Write-Progress `
    -Activity "Copying file" `
    -status ($from.Split("\")|select -last 1) `
    -PercentComplete 0
try {
    $sw = [System.Diagnostics.Stopwatch]::StartNew();
    [byte[]]$buff = new-object byte[] (4096*1024)
    [long]$total = [long]$count = 0
    do {
        $count = $ffile.Read($buff, 0, $buff.Length)
        $tofile.Write($buff, 0, $count)
        $total += $count
        [int]$pctcomp = ([int]($total/$ffile.Length* 100));
        [int]$secselapsed = [int]($sw.elapsedmilliseconds.ToString())/1000;
        if ( $secselapsed -ne 0 ) {
            [single]$xferrate = (($total/$secselapsed)/1mb);
        } else {
            [single]$xferrate = 0.0
        }
        if ($total % 1mb -eq 0) {
            if($pctcomp -gt 0)`
                {[int]$secsleft = ((($secselapsed/$pctcomp)* 100)-$secselapsed);
                } else {
                [int]$secsleft = 0};
            Write-Progress `
                -Activity ($pctcomp.ToString() + "% Copying file @ " + "{0:n2}" -f $xferrate + " MB/s")`
                -status ($from.Split("\")|select -last 1) `
                -PercentComplete $pctcomp `
                -SecondsRemaining $secsleft;
        }
    } while ($count -gt 0)
$sw.Stop();
$sw.Reset();
}
finally {
    write-host (($from.Split("\")|select -last 1) + `
     " copied in " + $secselapsed + " seconds at " + `
     "{0:n2}" -f [int](($ffile.length/$secselapsed)/1mb) + " MB/s.");
     $ffile.Close();
     $tofile.Close();
    }
}

Standard way to embed version into python package?

I also saw another style:

>>> django.VERSION
(1, 1, 0, 'final', 0)

How to view .img files?

If you want to open .img files, you can use 7-zip, which is freeware...

http://www.7-zip.org/

Once installed, right click on the relevant img file, hover over "7-zip", then click "Open Archive". Bear in mind, you need a seperate program, or Windows 7 to burn the image to disc!

Hope this helps!

Edit: Proof that it works (not my video, credit to howtodothe on YouTube).

Multiple input in JOptionPane.showInputDialog

Yes. You know that you can put any Object into the Object parameter of most JOptionPane.showXXX methods, and often that Object happens to be a JPanel.

In your situation, perhaps you could use a JPanel that has several JTextFields in it:

import javax.swing.*;

public class JOptionPaneMultiInput {
   public static void main(String[] args) {
      JTextField xField = new JTextField(5);
      JTextField yField = new JTextField(5);

      JPanel myPanel = new JPanel();
      myPanel.add(new JLabel("x:"));
      myPanel.add(xField);
      myPanel.add(Box.createHorizontalStrut(15)); // a spacer
      myPanel.add(new JLabel("y:"));
      myPanel.add(yField);

      int result = JOptionPane.showConfirmDialog(null, myPanel, 
               "Please Enter X and Y Values", JOptionPane.OK_CANCEL_OPTION);
      if (result == JOptionPane.OK_OPTION) {
         System.out.println("x value: " + xField.getText());
         System.out.println("y value: " + yField.getText());
      }
   }
}

SELECT CASE WHEN THEN (SELECT)

You should avoid using nested selects and I would go as far to say you should never use them in the actual select part of your statement. You will be running that select for each row that is returned. This is a really expensive operation. Rather use joins. It is much more readable and the performance is much better.

In your case the query below should help. Note the cases statement is still there, but now it is a simple compare operation.

select
    p.product_id,
    p.type_id,
    p.product_name,
    p.type,
    case p.type_id when 10 then (CONCAT_WS(' ' , first_name, middle_name, last_name )) else (null) end artistC
from
    Product p

    inner join Product_Type pt on
        pt.type_id = p.type_id

    left join Product_ArtistAuthor paa on
        paa.artist_id = p.artist_id
where
    p.product_id = $pid

I used a left join since I don't know the business logic.

Display QImage with QtGui

Simple, but complete example showing how to display QImage might look like this:

#include <QtGui/QApplication>
#include <QLabel>

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);

    QImage myImage;
    myImage.load("test.png");

    QLabel myLabel;
    myLabel.setPixmap(QPixmap::fromImage(myImage));

    myLabel.show();

    return a.exec();
}

Open an html page in default browser with VBA?

If you want a more robust solution with ShellExecute that will open ANY file, folder or URL using the default OS associated program to do so, here is a function taken from http://access.mvps.org/access/api/api0018.htm:

'************ Code Start **********
' This code was originally written by Dev Ashish.
' It is not to be altered or distributed,
' except as part of an application.
' You are free to use it in any application,
' provided the copyright notice is left unchanged.
'
' Code Courtesy of
' Dev Ashish
'
Private Declare Function apiShellExecute Lib "shell32.dll" _
    Alias "ShellExecuteA" _
    (ByVal hwnd As Long, _
    ByVal lpOperation As String, _
    ByVal lpFile As String, _
    ByVal lpParameters As String, _
    ByVal lpDirectory As String, _
    ByVal nShowCmd As Long) _
    As Long

'***App Window Constants***
Public Const WIN_NORMAL = 1         'Open Normal
Public Const WIN_MAX = 3            'Open Maximized
Public Const WIN_MIN = 2            'Open Minimized

'***Error Codes***
Private Const ERROR_SUCCESS = 32&
Private Const ERROR_NO_ASSOC = 31&
Private Const ERROR_OUT_OF_MEM = 0&
Private Const ERROR_FILE_NOT_FOUND = 2&
Private Const ERROR_PATH_NOT_FOUND = 3&
Private Const ERROR_BAD_FORMAT = 11&

'***************Usage Examples***********************
'Open a folder:     ?fHandleFile("C:\TEMP\",WIN_NORMAL)
'Call Email app:    ?fHandleFile("mailto:[email protected]",WIN_NORMAL)
'Open URL:          ?fHandleFile("http://home.att.net/~dashish", WIN_NORMAL)
'Handle Unknown extensions (call Open With Dialog):
'                   ?fHandleFile("C:\TEMP\TestThis",Win_Normal)
'Start Access instance:
'                   ?fHandleFile("I:\mdbs\CodeNStuff.mdb", Win_NORMAL)
'****************************************************

Function fHandleFile(stFile As String, lShowHow As Long)
Dim lRet As Long, varTaskID As Variant
Dim stRet As String
    'First try ShellExecute
    lRet = apiShellExecute(hWndAccessApp, vbNullString, _
            stFile, vbNullString, vbNullString, lShowHow)

    If lRet > ERROR_SUCCESS Then
        stRet = vbNullString
        lRet = -1
    Else
        Select Case lRet
            Case ERROR_NO_ASSOC:
                'Try the OpenWith dialog
                varTaskID = Shell("rundll32.exe shell32.dll,OpenAs_RunDLL " _
                        & stFile, WIN_NORMAL)
                lRet = (varTaskID <> 0)
            Case ERROR_OUT_OF_MEM:
                stRet = "Error: Out of Memory/Resources. Couldn't Execute!"
            Case ERROR_FILE_NOT_FOUND:
                stRet = "Error: File not found.  Couldn't Execute!"
            Case ERROR_PATH_NOT_FOUND:
                stRet = "Error: Path not found. Couldn't Execute!"
            Case ERROR_BAD_FORMAT:
                stRet = "Error:  Bad File Format. Couldn't Execute!"
            Case Else:
        End Select
    End If
    fHandleFile = lRet & _
                IIf(stRet = "", vbNullString, ", " & stRet)
End Function
'************ Code End **********

Just put this into a separate module and call fHandleFile() with the right parameters.

Client on Node.js: Uncaught ReferenceError: require is not defined

Even using this won't work. I think the best solution is Browserify:

module.exports = {
  func1: function () {
   console.log("I am function 1");
  },
  func2: function () {
    console.log("I am function 2");
  }
};

-getFunc1.js-
var common = require('./common');
common.func1();

How to install SQL Server Management Studio 2012 (SSMS) Express?

You need to install ENU\x64\SQLEXPRWT_x64_ENU.exe which is Express with Tools (RTM release. SP1 release can be found here).

As the page states

Express with Tools (with LocalDB) Includes the database engine and SQL Server Management Studio Express) This package contains everything needed to install and configure SQL Server as a database server. Choose either LocalDB or Express depending on your needs above.

So install this and use the management studio included with it.

PHP function to generate v4 UUID

Inspired by broofa's answer here.

preg_replace_callback('/[xy]/', function ($matches)
{
  return dechex('x' == $matches[0] ? mt_rand(0, 15) : (mt_rand(0, 15) & 0x3 | 0x8));
}
, 'xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx');

Or if unable to use anonymous functions.

preg_replace_callback('/[xy]/', create_function(
  '$matches',
  'return dechex("x" == $matches[0] ? mt_rand(0, 15) : (mt_rand(0, 15) & 0x3 | 0x8));'
)
, 'xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx');

Remove Array Value By index in jquery

Your example code is wrong and will throw a SyntaxError. You seem to have confused the syntax of creating an object Object with creating an Array.

The correct syntax would be: var arr = [ "abc", "def", "ghi" ];

To remove an item from the array, based on its value, use the splice method:

arr.splice(arr.indexOf("def"), 1);

To remove it by index, just refer directly to it:

arr.splice(1, 1);

MySQL - length() vs char_length()

varchar(10) will store 10 characters, which may be more than 10 bytes. In indexes, it will allocate the maximium length of the field - so if you are using UTF8-mb4, it will allocate 40 bytes for the 10 character field.

How do you make websites with Java?

I'll jump in with the notorious "Do you really want to do that" answer.

It seems like your focus is on playing with Java and seeing what it can do. However, if you want to actually develop a web app, you should be aware that, although Java is used in web applications (and in serious ones), there are other technology options which might be more adequate.

Personally, I like (and use) Java for powerful, portable backend services on a server. I've never tried building websites with it, because it never seemed the most obvious ting to do. After growing tired of PHP (which I have been using for years), I lately fell in love with Django, a Python-based web framework.

The Ruby on Rails people have a number of very funny videos on youtube comparing different web technologies to RoR. Of course, these are obviously exaggerated and maybe slightly biased, but I'd say there's more than one grain of truth in each of them. The one about Java is here. ;-)

How to pass multiple checkboxes using jQuery ajax post

This would be better and easy

var arr = $('input[name="user_ids[]"]').map(function(){
  return $(this).val();
}).get();

console.log(arr);

Wait until a process ends

Use Process.WaitForExit? Or subscribe to the Process.Exited event if you don't want to block? If that doesn't do what you want, please give us more information about your requirements.

How to get selected value of a html select with asp.net

<%@ Page Language="C#" AutoEventWireup="True" %>
<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml">    
<head>
    <title> HtmlSelect Example </title>
    <script runat="server">
      void Button_Click (Object sender, EventArgs e)
      {
         Label1.Text = "Selected index: " + Select1.SelectedIndex.ToString()
                       + ", value: " + Select1.Value;    
      }    
   </script>    
</head>    
<body>    
   <form id="form1" runat="server">

      Select an item: 

      <select id="Select1" runat="server">    
         <option value="Text for Item 1" selected="selected"> Item 1 </option>
         <option value="Text for Item 2"> Item 2 </option>
         <option value="Text for Item 3"> Item 3 </option>
         <option value="Text for Item 4"> Item 4 </option>
      </select>

      <button onserverclick="Button_Click" runat="server" Text="Submit"/>

      <asp:Label id="Label1" runat="server"/>    
   </form>
</body>
</html>

Source from Microsoft. Hope this is helpful!

Android - get children inside a View?

As an update for those who come across this question after 2018, if you are using Kotlin, you can simply use the Android KTX extension property ViewGroup.children to get a sequence of the View's immediate children.

What is a "thread" (really)?

Unfortunately, threads do exist. A thread is something tangible. You can kill one, and the others will still be running. You can spawn new threads.... although each thread is not it's own process, they are running separately inside the process. On multi-core machines, 2 threads could run at the same time.

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

http://www.intel.com/intelpress/samples/mcp_samplech01.pdf

Differences between C++ string == and compare()?

Internally, string::operator==() is using string::compare(). Please refer to: CPlusPlus - string::operator==()

I wrote a small application to compare the performance, and apparently if you compile and run your code on debug environment the string::compare() is slightly faster than string::operator==(). However if you compile and run your code in Release environment, both are pretty much the same.

FYI, I ran 1,000,000 iteration in order to come up with such conclusion.

In order to prove why in debug environment the string::compare is faster, I went to the assembly and here is the code:

DEBUG BUILD

string::operator==()

        if (str1 == str2)
00D42A34  lea         eax,[str2]  
00D42A37  push        eax  
00D42A38  lea         ecx,[str1]  
00D42A3B  push        ecx  
00D42A3C  call        std::operator==<char,std::char_traits<char>,std::allocator<char> > (0D23EECh)  
00D42A41  add         esp,8  
00D42A44  movzx       edx,al  
00D42A47  test        edx,edx  
00D42A49  je          Algorithm::PerformanceTest::stringComparison_usingEqualOperator1+0C4h (0D42A54h)  

string::compare()

            if (str1.compare(str2) == 0)
00D424D4  lea         eax,[str2]  
00D424D7  push        eax  
00D424D8  lea         ecx,[str1]  
00D424DB  call        std::basic_string<char,std::char_traits<char>,std::allocator<char> >::compare (0D23582h)  
00D424E0  test        eax,eax  
00D424E2  jne         Algorithm::PerformanceTest::stringComparison_usingCompare1+0BDh (0D424EDh)

You can see that in string::operator==(), it has to perform extra operations (add esp, 8 and movzx edx,al)

RELEASE BUILD

string::operator==()

        if (str1 == str2)
008533F0  cmp         dword ptr [ebp-14h],10h  
008533F4  lea         eax,[str2]  
008533F7  push        dword ptr [ebp-18h]  
008533FA  cmovae      eax,dword ptr [str2]  
008533FE  push        eax  
008533FF  push        dword ptr [ebp-30h]  
00853402  push        ecx  
00853403  lea         ecx,[str1]  
00853406  call        std::basic_string<char,std::char_traits<char>,std::allocator<char> >::compare (0853B80h)  

string::compare()

            if (str1.compare(str2) == 0)
    00853830  cmp         dword ptr [ebp-14h],10h  
    00853834  lea         eax,[str2]  
    00853837  push        dword ptr [ebp-18h]  
    0085383A  cmovae      eax,dword ptr [str2]  
    0085383E  push        eax  
    0085383F  push        dword ptr [ebp-30h]  
    00853842  push        ecx  
00853843  lea         ecx,[str1]  
00853846  call        std::basic_string<char,std::char_traits<char>,std::allocator<char> >::compare (0853B80h)

Both assembly code are very similar as the compiler perform optimization.

Finally, in my opinion, the performance gain is negligible, hence I would really leave it to the developer to decide on which one is the preferred one as both achieve the same outcome (especially when it is release build).

Is there a Subversion command to reset the working copy?

svn revert . -R

to reset everything.

svn revert path/to/file

for a single file

scikit-learn random state in splitting dataset

It doesn't matter if the random_state is 0 or 1 or any other integer. What matters is that it should be set the same value, if you want to validate your processing over multiple runs of the code. By the way I have seen random_state=42 used in many official examples of scikit as well as elsewhere also.

random_state as the name suggests, is used for initializing the internal random number generator, which will decide the splitting of data into train and test indices in your case. In the documentation, it is stated that:

If random_state is None or np.random, then a randomly-initialized RandomState object is returned.

If random_state is an integer, then it is used to seed a new RandomState object.

If random_state is a RandomState object, then it is passed through.

This is to check and validate the data when running the code multiple times. Setting random_state a fixed value will guarantee that same sequence of random numbers are generated each time you run the code. And unless there is some other randomness present in the process, the results produced will be same as always. This helps in verifying the output.

How can I get the application's path in a .NET console application?

System.Reflection.Assembly.GetExecutingAssembly().Location1

Combine that with System.IO.Path.GetDirectoryName if all you want is the directory.

1As per Mr.Mindor's comment:
System.Reflection.Assembly.GetExecutingAssembly().Location returns where the executing assembly is currently located, which may or may not be where the assembly is located when not executing. In the case of shadow copying assemblies, you will get a path in a temp directory. System.Reflection.Assembly.GetExecutingAssembly().CodeBase will return the 'permanent' path of the assembly.

Setting the MySQL root user password on OS X

Let us add this workaround that works on my laptop!

Mac with Osx Mojave 10.14.5

Mysql 8.0.17 was installed with homebrew

  • I run the following command to locate the path of mysql

    brew info mysql

  • Once the path is known, I run this :

    /usr/local/Cellar/mysql/8.0.17/bin/mysqld_safe --skip-grant-table

  • In another terminal I run :

    mysql -u root

  • Inside that terminal, I changed the root password using :

    update mysql.user set authentication_string='NewPassword' where user='root';

  • and to finish I run :

    FLUSH PRIVILEGES;

And voila the password was reset.

References :

What is the difference between YAML and JSON?

This question is 6 years old, but strangely, none of the answers really addresses all four points (speed, memory, expressiveness, portability).

Speed

Obviously this is implementation-dependent, but because JSON is so widely used, and so easy to implement, it has tended to receive greater native support, and hence speed. Considering that YAML does everything that JSON does, plus a truckload more, it's likely that of any comparable implementations of both, the JSON one will be quicker.

However, given that a YAML file can be slightly smaller than its JSON counterpart (due to fewer " and , characters), it's possible that a highly optimised YAML parser might be quicker in exceptional circumstances.

Memory

Basically the same argument applies. It's hard to see why a YAML parser would ever be more memory efficient than a JSON parser, if they're representing the same data structure.

Expressiveness

As noted by others, Python programmers tend towards preferring YAML, JavaScript programmers towards JSON. I'll make these observations:

  • It's easy to memorise the entire syntax of JSON, and hence be very confident about understanding the meaning of any JSON file. YAML is not truly understandable by any human. The number of subtleties and edge cases is extreme.
  • Because few parsers implement the entire spec, it's even harder to be certain about the meaning of a given expression in a given context.
  • The lack of comments in JSON is, in practice, a real pain.

Portability

It's hard to imagine a modern language without a JSON library. It's also hard to imagine a JSON parser implementing anything less than the full spec. YAML has widespread support, but is less ubiquitous than JSON, and each parser implements a different subset. Hence YAML files are less interoperable than you might think.

Summary

JSON is the winner for performance (if relevant) and interoperability. YAML is better for human-maintained files. HJSON is a decent compromise although with much reduced portability. JSON5 is a more reasonable compromise, with well-defined syntax.

How do I cast a string to integer and have 0 in case of error in the cast with PostgreSQL?

Finally I manage to ignore the invalid characters and get only the numbers to convert the text to numeric.

SELECT (NULLIF(regexp_replace(split_part(column1, '.', 1), '\D','','g'), '') 
    || '.' || COALESCE(NULLIF(regexp_replace(split_part(column1, '.', 2), '\D','','g'),''),'00')) AS result,column1
FROM (VALUES
    ('ggg'),('3,0 kg'),('15 kg.'),('2x3,25'),('96+109'),('1.10'),('132123')
) strings;  

Replacing accented characters php

You can use PHP strtr() function to get rid of accented characters :

$string = "Éric Cantona";
$accented_array = array('Š'=>'S', 'š'=>'s', 'Ž'=>'Z', 'ž'=>'z', 'À'=>'A', 'Á'=>'A', 'Â'=>'A', 'Ã'=>'A', 'Ä'=>'A', 'Å'=>'A', 'Æ'=>'A', 'Ç'=>'C', 'È'=>'E', 'É'=>'E','Ê'=>'E', 'Ë'=>'E', 'Ì'=>'I', 'Í'=>'I', 'Î'=>'I', 'Ï'=>'I', 'Ñ'=>'N', 'Ò'=>'O', 'Ó'=>'O', 'Ô'=>'O', 'Õ'=>'O', 'Ö'=>'O', 'Ø'=>'O', 'Ù'=>'U','Ú'=>'U', 'Û'=>'U', 'Ü'=>'U', 'Ý'=>'Y', 'Þ'=>'B', 'ß'=>'Ss', 'à'=>'a', 'á'=>'a', 'â'=>'a', 'ã'=>'a', 'ä'=>'a', 'å'=>'a', 'æ'=>'a', 'ç'=>'c','è'=>'e', 'é'=>'e', 'ê'=>'e', 'ë'=>'e', 'ì'=>'i', 'í'=>'i', 'î'=>'i', 'ï'=>'i', 'ð'=>'o', 'ñ'=>'n', 'ò'=>'o', 'ó'=>'o', 'ô'=>'o', 'õ'=>'o','ö'=>'o', 'ø'=>'o', 'ù'=>'u', 'ú'=>'u', 'û'=>'u', 'ý'=>'y', 'þ'=>'b', 'ÿ'=>'y' );

$required_str = strtr( $string, $accented_array );

must declare a named package eclipse because this compilation unit is associated to the named module

The "delete module-info.java at your Project Explorer tab" answer is the easiest and most straightforward answer, but

for those who would want a little more understanding or control of what's happening, the following alternate methods may be desirable;

  • make an ever so slightly more realistic application; com.YourCompany.etc or just com.HelloWorld (Project name: com.HelloWorld and class name: HelloWorld)

or

  • when creating the java project; when in the Create Java Project dialog, don't choose Finish but Next, and deselect Create module-info.java file

Cannot checkout, file is unmerged

In my case, I found that I need the -f option. Such as the following:

git rm -f first_file.txt

to get rid of the "needs merge" error.

How to Write text file Java

Using java 8 LocalDateTime and java 7 try-with statement:

public class WriteFile {

    public static void main(String[] args) {

        String timeLog = DateTimeFormatter.ofPattern("yyyyMMdd_HHmmss").format(LocalDateTime.now());
        File logFile = new File(timeLog);

        try (BufferedWriter bw = new BufferedWriter(new FileWriter(logFile))) 
        {
            System.out.println("File was written to: "  + logFile.getCanonicalPath());
            bw.write("Hello world!");
        } 
        catch (IOException e) 
        {
            e.printStackTrace();
        }
    }
}

Multiline TextBox multiple newline

Try this one

textBox1.Text = "Line1" + Environment.NewLine + "Line2";

Working fine for me...

jQuery add blank option to top of list and make selected to existing dropdown

This worked:

$("#theSelectId").prepend("<option value='' selected='selected'></option>");

Firebug Output:

<select id="theSelectId">
  <option selected="selected" value=""/>
  <option value="volvo">Volvo</option>
  <option value="saab">Saab</option>
  <option value="mercedes">Mercedes</option>
  <option value="audi">Audi</option>
</select>

You could also use .prependTo if you wanted to reverse the order:

?$("<option>", { value: '', selected: true }).prependTo("#theSelectId");???????????

How to check the installed version of React-Native

To see what version you have on your Mac(Window also can run that code.), run react-native -v and you should get something like this:

enter image description here

If you want to know what version your project is running, look in /node_modules/react-native/package.json and look for the version key:

enter image description here

Java Runtime.getRuntime(): getting output from executing a command line program

Here is the way to go:

Runtime rt = Runtime.getRuntime();
String[] commands = {"system.exe", "-get t"};
Process proc = rt.exec(commands);

BufferedReader stdInput = new BufferedReader(new 
     InputStreamReader(proc.getInputStream()));

BufferedReader stdError = new BufferedReader(new 
     InputStreamReader(proc.getErrorStream()));

// Read the output from the command
System.out.println("Here is the standard output of the command:\n");
String s = null;
while ((s = stdInput.readLine()) != null) {
    System.out.println(s);
}

// Read any errors from the attempted command
System.out.println("Here is the standard error of the command (if any):\n");
while ((s = stdError.readLine()) != null) {
    System.out.println(s);
}

Read the Javadoc for more details here. ProcessBuilder would be a good choice to use.

How can I selectively merge or pick changes from another branch in Git?

I would do a

git diff commit1..commit2 filepattern | git-apply --index && git commit

This way you can limit the range of commits for a filepattern from a branch.

It is stolen from Re: How to pull only a few files from one branch to another?

How to call getClass() from a static method in Java?

As for the code example in the question, the standard solution is to reference the class explicitly by its name, and it is even possible to do without getClassLoader() call:

class MyClass {
  public static void startMusic() {
    URL songPath = MyClass.class.getResource("background.midi");
  }
}

This approach still has a back side that it is not very safe against copy/paste errors in case you need to replicate this code to a number of similar classes.

And as for the exact question in the headline, there is a trick posted in the adjacent thread:

Class currentClass = new Object() { }.getClass().getEnclosingClass();

It uses a nested anonymous Object subclass to get hold of the execution context. This trick has a benefit of being copy/paste safe...

Caution when using this in a Base Class that other classes inherit from:

It is also worth noting that if this snippet is shaped as a static method of some base class then currentClass value will always be a reference to that base class rather than to any subclass that may be using that method.

Vue 'export default' vs 'new Vue'

Whenever you use

export someobject

and someobject is

{
 "prop1":"Property1",
 "prop2":"Property2",
}

the above you can import anywhere using import or module.js and there you can use someobject. This is not a restriction that someobject will be an object only it can be a function too, a class or an object.

When you say

new Object()

like you said

new Vue({
  el: '#app',
  data: []
)}

Here you are initiating an object of class Vue.

I hope my answer explains your query in general and more explicitly.

How to serve static files in Flask

For angular+boilerplate flow which creates next folders tree:

backend/
|
|------ui/
|      |------------------build/          <--'static' folder, constructed by Grunt
|      |--<proj           |----vendors/   <-- angular.js and others here
|      |--     folders>   |----src/       <-- your js
|                         |----index.html <-- your SPA entrypoint 
|------<proj
|------     folders>
|
|------view.py  <-- Flask app here

I use following solution:

...
root = os.path.join(os.path.dirname(os.path.abspath(__file__)), "ui", "build")

@app.route('/<path:path>', methods=['GET'])
def static_proxy(path):
    return send_from_directory(root, path)


@app.route('/', methods=['GET'])
def redirect_to_index():
    return send_from_directory(root, 'index.html')
...

It helps to redefine 'static' folder to custom.

setting textColor in TextView in layout/main.xml main layout file not referencing colors.xml file. (It wants a #RRGGBB instead of @color/text_color)

You should write textcolor in xml as

android:textColor="@color/text_color"

or

android:textColor="#FFFFFF"

moment.js 24h format

_x000D_
_x000D_
//Format 24H use HH:mm_x000D_
let currentDate = moment().format('YYYY-MM-DD HH:mm')_x000D_
console.log(currentDate)_x000D_
_x000D_
//example of current time with defined Time zone +1_x000D_
let currentDateTm = moment().utcOffset('+0100').format('YYYY-MM-DD HH:mm')_x000D_
console.log(currentDateTm)
_x000D_
<script src="https://momentjs.com/downloads/moment.js"></script>
_x000D_
_x000D_
_x000D_

How make background image on newsletter in outlook?

Powerful tool for "Bulletproof Email Background Images" (VML for Outlook 2007/2010/2013, and HTML/CSS for Outlook 2000/2003, Gmail, Hotmail...)

http://emailbg.net

as an exemple :

    <div style="background-color:#f6f6f6;">
  <!--[if gte mso 9]>
  <v:background xmlns:v="urn:schemas-microsoft-com:vml" fill="t">
    <v:fill type="tile" src="http://i.imgur.com/n8Q6f.png" color="#f6f6f6"/>
  </v:background>
  <![endif]-->
  <table height="100%" width="100%" cellpadding="0" cellspacing="0" border="0">
    <tr>
      <td valign="top" align="left" background="http://i.imgur.com/n8Q6f.png">
      </td>
    </tr>
  </table>
</div>

in order to have the specified background image to Full email body.

This link help to use the Vector Markup Language (VML)

msdn.microsoft.com/en-us/library/bb264137%28v=vs.85%29.aspx

www.w3.org/TR/NOTE-VML#_Toc416858389

no match for ‘operator<<’ in ‘std::operator

Object is a collection of methods and variables.You can't print the variables in object by just cout operation . if you want to show the things inside the object you have to declare either a getter or a display text method in class.

ex

#include <iostream>

using namespace std;

class mystruct

{
private:
    int m_a;
    float m_b;

public:
    mystruct(int x, float y)
    {
            m_a = x;
            m_b = y;
    }
    public:
    void getm_aAndm_b()
    {
        cout<<m_a<<endl;
        cout<<m_b<<endl;
    }



};

int main()
{

    mystruct m = mystruct(5,3.14);

    cout << "my structure " << endl;
    m.getm_aAndm_b();
    return 0;

}

Not that this is just a one way of doing it

Save a file in json format using Notepad++

In Notepad++ on the Language menu you will find the menu item - 'J' and under this menu item chose the language - JSON.

Once you select the JSON language then you won't have to worry about how to save it. When you save it it will by default save it as .JSON file, you have to just select the location of the file.

Thanks, -Sam

Please look at the pic, it will give you a better idea..

Using momentjs to convert date to epoch then back to date

http://momentjs.com/docs/#/displaying/unix-timestamp/

You get the number of unix seconds, not milliseconds!

You you need to multiply it with 1000 or using valueOf() and don't forget to use a formatter, since you are using a non ISO 8601 format. And if you forget to pass the formatter, the date will be parsed in the UTC timezone or as an invalid date.

moment("10/15/2014 9:00", "MM/DD/YYYY HH:mm").valueOf()

Difference between xcopy and robocopy

The differences I could see is that Robocopy has a lot more options, but I didn't find any of them particularly helpful unless I'm doing something special.

I did some benchmarking of several copy routines and found XCOPY and ROBOCOPY to be the fastest, but to my surprise, XCOPY consistently edged out Robocopy.

It's ironic that robocopy retries a copy that fails, but it also failed a lot in my benchmark tests, where xcopy never did.

I did full file (byte by byte) file compares after my benchmark tests.

Here are the switches I used with robocopy in my tests:

 **"/E /R:1 /W:1 /NP /NFL /NDL"**.  

If anyone knows a faster combination (other than removing /E, which I need), I'd love to hear.

Another interesting/disappointing thing with robocopy is that if a copy does fail, by default it retries 1,000,000 times with a 30 second delay between each try. If you are running a long batch file unattended, you may be very disappointed when you come back after a few hours to find it's still trying to copy a particular file.

The /R and /W switches let you change this behavior.

  • With /R you can tell it how many times to retry,
  • /W let's you specify the wait time before retries.

If there's a way to attach files here, I can share my results.

  • My tests were all done on the same computer and
  • copied files from one external drive to another external,
  • both on USB 3.0 ports.

I also included FastCopy and Windows Copy in my tests and each test was run 10 times. Note, the differences were pretty significant. The 95% confidence intervals had no overlap.

Laravel 5.2 - Use a String as a Custom Primary Key for Eloquent Table becomes 0

I was using Postman to test my Laravel API.

I received an error that stated

"SQLSTATE[42S22]: Column not found: 1054 Unknown column" because Laravel was trying to automatically create two columns "created_at" and "updated_at".

I had to enter public $timestamps = false; to my model. Then, I tested again with Postman and saw that an "id" = 0 variable was being created in my database.

I finally had to add public $incrementing false; to fix my API.

How to squash all git commits into one?

To do this, you can reset you local git repository to the first commit hashtag, so all your changes after that commit will be unstaged, then you can commit with --amend option.

git reset your-first-commit-hashtag
git add .
git commit --amend

And then edit the first commit nam if needed and save file.

MATLAB error: Undefined function or method X for input arguments of type 'double'

Also, name it divrat.m, not divrat.M. This shouldn't matter on most OSes, but who knows...

You can also test whether matlab can find a function by using the which command, i.e.

which divrat

Convert NSNumber to int in Objective-C

A less verbose approach:

int number = [dict[@"integer"] intValue];

How to use Python requests to fake a browser visit a.k.a and generate User Agent?

The root of the answer is that the person asking the question needs to have a JavaScript interpreter to get what they are after. What I have found is I am able to get all of the information I wanted on a website in json before it was interpreted by JavaScript. This has saved me a ton of time in what would be parsing html hoping each webpage is in the same format.

So when you get a response from a website using requests really look at the html/text because you might find the javascripts JSON in the footer ready to be parsed.

JIRA JQL searching by date - is there a way of getting Today() (Date) instead of Now() (DateTime)

You might use one of our plugins: the JQL enhancement functions - check out https://plugins.atlassian.com/plugin/details/22514

There is no interval on day, but we might add it in a next iteration, if you think it is usefull.

Francis.

HTML5 iFrame Seamless Attribute

Updated: October 2016

The seamless attribute no longer exists. It was originally pitched to be included in the first HTML5 spec, but subsequently dropped. An unrelated attribute of the same name made a brief cameo in the HTML5.1 draft, but that too was ditched mid-2016:

So I think the gist of it all both from the implementor side and the web-dev side is that seamless as-specced doesn’t seem to be what anybody wanted to begin with. Or at least it’s more than anybody actually wanted. And anyway like @annevk says, it’s seems a lot of it’s since been “overcome by events” in light of Shadow DOM.

In other words: purge the seamless attribute from your memory, and pretend it never existed.

For posterity's sake, here's my original answer from five years ago:

Original answer: April 2011

The attribute is in draft mode at the moment. For that reason, none of the current browsers are supporting it yet (as the implementation is subject to change). In the meantime, it's best just to use CSS to strip the borders/scrollbars from the iframe:

iframe[seamless]{
    background-color: transparent;
    border: 0px none transparent;
    padding: 0px;
    overflow: hidden;
}

There's more to the seamless attribute than what can be added with CSS: part of the reasoning behind the attribute was to allow nested content to inherit the same styles applied to the iframe (acting as though the embedded document was one big nested inside the element, for example).

Lastly, versions of Internet Explorer (8 and earlier) require additional attributes in order to remove the borders, scrollbars and background colour:

<iframe frameborder="0" allowtransparency="true" scrolling="no" src="..."></iframe>

Naturally, this doesn't validate. So it's up to you how to handle it. My (picky) approach would be to sniff the agent string and add the attributes for IE versions earlier than 9.

Hope that helps. :)

PHP expects T_PAAMAYIM_NEKUDOTAYIM?

Edit: Unfortunately, as of PHP 8.0, the answer is not "No, not anymore". This RFC was not accepted as I hoped, proposing to change T_PAAMAYIM_NEKUDOTAYIM to T_DOUBLE_COLON; but it was declined.

Note: I keep this answer for historical purposes. Actually, because of the creation of the RFC and the votes ratio at some point, I created this answer. Also, I keep this for hoping it to be accepted in the near future.

How to get an array of unique values from an array containing duplicates in JavaScript?

Array.prototype.unique =function(){
    var uniqObj={};
    for(var i=0;i< this.length;i++){
      uniqObj[this[i]]=this[i]; 
    }
    return uniqObj;
}

How to create an Array with AngularJS's ng-model

How to create an array of inputs with ng-model

Use the ng-repeat directive:

<ol>
  <li ng-repeat="n in [] | range:count">
    <input name="telephone-{{$index}}"
           ng-model="telephones[$index].value" >
  </li>
</ol>

The DEMO

_x000D_
_x000D_
angular.module("app",[])_x000D_
.controller("ctrl",function($scope){_x000D_
  $scope.count = 3;_x000D_
  $scope.telephones = [];_x000D_
})_x000D_
.filter("range",function() {_x000D_
  return (x,n) => Array.from({length:n},(x,index)=>(index));_x000D_
})
_x000D_
<script src="//unpkg.com/angular/angular.js"></script>_x000D_
<body ng-app="app" ng-controller="ctrl">_x000D_
    <button>_x000D_
      Array length_x000D_
      <input type="number" ng-model="count" _x000D_
             ng-change="telephones.length=count">_x000D_
    </button>_x000D_
    <ol>_x000D_
      <li ng-repeat="n in [] | range:count">_x000D_
        <input name="telephone-{{$index}}"_x000D_
               ng-model="telephones[$index].value" >_x000D_
      </li>_x000D_
    </ol>  _x000D_
    {{telephones}}_x000D_
</body>
_x000D_
_x000D_
_x000D_

How to add new column to an dataframe (to the front not end)?

df <- data.frame(b = c(1, 1, 1), c = c(2, 2, 2), d = c(3, 3, 3))
df
##   b c d
## 1 1 2 3
## 2 1 2 3
## 3 1 2 3

df <- data.frame(a = c(0, 0, 0), df)
df
##   a b c d
## 1 0 1 2 3
## 2 0 1 2 3
## 3 0 1 2 3

How to overwrite the output directory in spark

UPDATE: Suggest using Dataframes, plus something like ... .write.mode(SaveMode.Overwrite) ....

Handy pimp:

implicit class PimpedStringRDD(rdd: RDD[String]) {
    def write(p: String)(implicit ss: SparkSession): Unit = {
      import ss.implicits._
      rdd.toDF().as[String].write.mode(SaveMode.Overwrite).text(p)
    }
  }

For older versions try

yourSparkConf.set("spark.hadoop.validateOutputSpecs", "false")
val sc = SparkContext(yourSparkConf)

In 1.1.0 you can set conf settings using the spark-submit script with the --conf flag.

WARNING (older versions): According to @piggybox there is a bug in Spark where it will only overwrite files it needs to to write it's part- files, any other files will be left unremoved.

fatal error C1083: Cannot open include file: 'xyz.h': No such file or directory?

I ran into this error in a different situation, posting the resolution for those arriving via search: from within Visual Studio, I had copied a file from one project and pasted into another. Turns out that creates a symbolic link, not an actual copy. Thus the project did not find the file in the current working directory as expected. When I made a physical copy instead, in Windows Explorer, suddenly #include "myfile.h" worked.

Delete a row in DataGridView Control in VB.NET

For Each row As DataGridViewRow In yourDGV.SelectedRows
    yourDGV.Rows.Remove(row)
Next

This will delete all rows that had been selected.

View a file in a different Git branch without changing branches

git show somebranch:path/to/your/file

you can also do multiple files and have them concatenated:

git show branchA~10:fileA branchB^^:fileB

You do not have to provide the full path to the file, relative paths are acceptable e.g.:

git show branchA~10:../src/hello.c

If you want to get the file in the local directory (revert just one file) you can checkout:

git checkout somebranch^^^ -- path/to/file

VBA check if file exists

For checking existence one can also use (works for both, files and folders):

Not Dir(DirFile, vbDirectory) = vbNullString

The result is True if a file or a directory exists.

Example:

If Not Dir("C:\Temp\test.xlsx", vbDirectory) = vbNullString Then
    MsgBox "exists"
Else
    MsgBox "does not exist"
End If

No Activity found to handle Intent : android.intent.action.VIEW

This is the right way to do it.

    try
    {
    Intent myIntent = new Intent(android.content.Intent.ACTION_VIEW);
    File file = new File(aFile.getAbsolutePath()); 
    String extension = android.webkit.MimeTypeMap.getFileExtensionFromUrl(Uri.fromFile(file).toString());
    String mimetype = android.webkit.MimeTypeMap.getSingleton().getMimeTypeFromExtension(extension);
    myIntent.setDataAndType(Uri.fromFile(file),mimetype);
    startActivity(myIntent);
    }
    catch (Exception e) 
    {
        // TODO: handle exception
        String data = e.getMessage();
    }

you need to import import android.webkit.MimeTypeMap;

How to connect wireless network adapter to VMWare workstation?

Change your network adapter to a bridged connection, this will directly connect to your computers physical network.

Java: how do I initialize an array size if it's unknown?

String line=sc.nextLine();
    int counter=1;
    for(int i=0;i<line.length();i++) {
        if(line.charAt(i)==' ') {
            counter++;
        }
    }
    long[] numbers=new long[counter];
    counter=0;
    for(int i=0;i<line.length();i++){
        int j=i;
        while(true) {
            if(j>=line.length() || line.charAt(j)==' ') {
                break;
            }
            j++;
        }
        numbers[counter]=Integer.parseInt(line.substring(i,j));
        i=j;
        counter++;  
    }
    for(int i=0;i<counter;i++) {
        System.out.println(numbers[i]);
    }    

I always use this code for situations like this. beside you can recognize two or three or more digit numbers.

How can I execute PHP code from the command line?

You can use:

 echo '<?php if(function_exists("my_func")) echo "function exists"; ' | php

The short tag "< ?=" can be helpful too:

 echo '<?= function_exists("foo") ? "yes" : "no";' | php
 echo '<?= 8+7+9 ;' | php

The closing tag "?>" is optional, but don't forget the final ";"!

Case-insensitive string comparison in C++

Short and nice. No other dependencies, than extended std C lib.

strcasecmp(str1.c_str(), str2.c_str()) == 0

returns true if str1 and str2 are equal. strcasecmp may not exist, there could be analogs stricmp, strcmpi, etc.

Example code:

#include <iostream>
#include <string>
#include <string.h> //For strcasecmp(). Also could be found in <mem.h>

using namespace std;

/// Simple wrapper
inline bool str_ignoreCase_cmp(std::string const& s1, std::string const& s2) {
    if(s1.length() != s2.length())
        return false;  // optimization since std::string holds length in variable.
    return strcasecmp(s1.c_str(), s2.c_str()) == 0;
}

/// Function object - comparator
struct StringCaseInsensetiveCompare {
    bool operator()(std::string const& s1, std::string const& s2) {
        if(s1.length() != s2.length())
            return false;  // optimization since std::string holds length in variable.
        return strcasecmp(s1.c_str(), s2.c_str()) == 0;
    }
    bool operator()(const char *s1, const char * s2){ 
        return strcasecmp(s1,s2)==0;
    }
};


/// Convert bool to string
inline char const* bool2str(bool b){ return b?"true":"false"; }

int main()
{
    cout<< bool2str(strcasecmp("asd","AsD")==0) <<endl;
    cout<< bool2str(strcasecmp(string{"aasd"}.c_str(),string{"AasD"}.c_str())==0) <<endl;
    StringCaseInsensetiveCompare cmp;
    cout<< bool2str(cmp("A","a")) <<endl;
    cout<< bool2str(cmp(string{"Aaaa"},string{"aaaA"})) <<endl;
    cout<< bool2str(str_ignoreCase_cmp(string{"Aaaa"},string{"aaaA"})) <<endl;
    return 0;
}

Output:

true
true
true
true
true

if checkbox is checked, do this

It may happen that "this.checked" is always "on". Therefore, I recommend:

$('#checkbox').change(function() {
  if ($(this).is(':checked')) {
    console.log('Checked');
  } else {
    console.log('Unchecked');
  }
});

Multiple linear regression in Python

sklearn.linear_model.LinearRegression will do it:

from sklearn import linear_model
clf = linear_model.LinearRegression()
clf.fit([[getattr(t, 'x%d' % i) for i in range(1, 8)] for t in texts],
        [t.y for t in texts])

Then clf.coef_ will have the regression coefficients.

sklearn.linear_model also has similar interfaces to do various kinds of regularizations on the regression.

Extracting the top 5 maximum values in excel

To my mind the case for a PT (as @Nathan Fisher) is a 'no brainer', but I would add a column to facilitate ordering by rank (up or down):

SO18528624 first example

OPS is entered as VALUES (Sum of) twice so I have renamed the column labels to make clearer which is which. The PT is in a different sheet from the data but could be in the same sheet.

Rank is set with a right click on a data point selected in that column and Show Values As... and Rank Largest to Smallest (there are other options) with the Base field as Player and the filter is a Value Filters, Top 10... one:

SO18528624 second example

Once in a PT the power of that feature can very easily be applied to view the data in many other ways, with no change of formula (there isn't one!).

In the case of a tie for the last position included in the filter both results are included (Top 5 would show six or more results). A tie for top rank between just two players would show as 1 1 3 4 5 for Top 5.

AngularJS app.run() documentation?

Here's the calling order:

  1. app.config()
  2. app.run()
  3. directive's compile functions (if they are found in the dom)
  4. app.controller()
  5. directive's link functions (again, if found)

Here's a simple demo where you can watch each one executing (and experiment if you'd like).

From Angular's module docs:

Run blocks - get executed after the injector is created and are used to kickstart the application. Only instances and constants can be injected into run blocks. This is to prevent further system configuration during application run time.

Run blocks are the closest thing in Angular to the main method. A run block is the code which needs to run to kickstart the application. It is executed after all of the services have been configured and the injector has been created. Run blocks typically contain code which is hard to unit-test, and for this reason should be declared in isolated modules, so that they can be ignored in the unit-tests.

One situation where run blocks are used is during authentications.

Import functions from another js file. Javascript

The following works for me in Firefox and Chrome. In Firefox it even works from file:///

models/course.js

export function Course() {
    this.id = '';
    this.name = '';
};

models/student.js

import { Course } from './course.js';

export function Student() {
    this.firstName = '';
    this.lastName = '';
    this.course = new Course();
};

index.html

<div id="myDiv">
</div>
<script type="module">
    import { Student } from './models/student.js';

    window.onload = function () {
        var x = new Student();
        x.course.id = 1;
        document.getElementById('myDiv').innerHTML = x.course.id;
    }
</script>

WHERE IS NULL, IS NOT NULL or NO WHERE clause depending on SQL Server parameter value

I've had success with this solution. It's almost like Patrick's, with a little twist. You can use these expressions separately or in sequence. If the parameter is blank, it will be ignored and all values for the column that your searching will be displayed, including NULLS.

SELECT * FROM MyTable
WHERE 
    --check to see if @param1 exists, if @param1 is blank, return all
    --records excluding filters below
(Col1 LIKE '%' + @param1 + '%' OR @param1 = '')
AND
    --where you want to search multiple columns using the same parameter
    --enclose the first 'OR' expression in braces and enclose the entire 
    --expression 
((Col2 LIKE '%' + @searchString + '%' OR Col3 LIKE '%' + @searchString + '%') OR @searchString = '')
AND
    --if your search requires a date you could do the following
(Cast(DateCol AS DATE) BETWEEN CAST(@dateParam AS Date) AND CAST(GETDATE() AS DATE) OR @dateParam = '')

What are all possible pos tags of NLTK?

The book has a note how to find help on tag sets, e.g.:

nltk.help.upenn_tagset()

Others are probably similar. (Note: Maybe you first have to download tagsets from the download helper's Models section for this)

simple vba code gives me run time error 91 object variable or with block not set

Check the version of the excel, if you are using older version then Value2 is not available for you and thus it is showing an error, while it will work with 2007+ version. Or the other way, the object is not getting created and thus the Value2 property is not available for the object.

Java equivalent to Explode and Implode(PHP)

if you are talking about in the reference of String Class. so you can use

subString/split

for Explode & use String

concate

for Implode.

Vue v-on:click does not work on component

A bit verbose but this is how I do it:

@click="$emit('click', $event)"

UPDATE: Example added by @sparkyspider

<div-container @click="doSomething"></div-container>

In div-container component...

<template>
  <div @click="$emit('click', $event);">The inner div</div>
</template>

Why do I get "Exception; must be caught or declared to be thrown" when I try to compile my Java code?

All your problems derive from this

byte[] encrypted = cipher.doFinal(toEncrypt.getBytes());
return encrypted;

Which are enclosed in a try, catch block, the problem is that in case the program found an exception you are not returning anything. Put it like this (modify it as your program logic stands):

public static byte[] encrypt(String toEncrypt) throws Exception{
    try{
        String plaintext = toEncrypt;
        String key = "01234567890abcde";
        String iv = "fedcba9876543210";

        SecretKeySpec keyspec = new SecretKeySpec(key.getBytes(), "AES");
        IvParameterSpec ivspec = new IvParameterSpec(iv.getBytes());

        Cipher cipher = Cipher.getInstance("AES/CBC/NoPadding");
        cipher.init(Cipher.ENCRYPT_MODE,keyspec,ivspec);
        byte[] encrypted = cipher.doFinal(toEncrypt.getBytes());

        return encrypted;
    } catch(Exception e){
        return null;            // Always must return something
    }
}

For the second one you must catch the Exception from the encrypt method call, like this (also modify it as your program logic stands):

public void actionPerformed(ActionEvent e)
  .
  .
  .
    try {
        byte[] encrypted = encrypt(concatURL);
        String encryptedString = bytesToHex(encrypted);
        content.removeAll();
        content.add(new JLabel("Concatenated User Input -->" + concatURL));

        content.add(encryptedTextField);
    setContentPane(content);
    } catch (Exception exc) {
        // TODO: handle exception
    }
}

The lessons you must learn from this:

  • A method with a return-type must always return an object of that type, I mean in all possible scenarios
  • All checked exceptions must always be handled

How to enable MySQL Query Log?

I use this method for logging when I want to quickly optimize different page loads. It's a little tip...

Logging to a TABLE

SET global general_log = 1;
SET global log_output = 'table';

You can then select from my mysql.general_log table to retrieve recent queries.

I can then do something similar to tail -f on the mysql.log, but with more refinements...

select * from mysql.general_log 
where  event_time  > (now() - INTERVAL 8 SECOND) and thread_id not in(9 , 628)
and argument <> "SELECT 1" and argument <> "" 
and argument <> "SET NAMES 'UTF8'"  and argument <> "SHOW STATUS"  
and command_type = "Query"  and argument <> "SET PROFILING=1"

This makes it easy to see my queries that I can try and cut back. I use 8 seconds interval to only fetch queries executed within the last 8 seconds.

Matplotlib 2 Subplots, 1 Colorbar

Shared colormap and colorbar

This is for the more complex case where the values are not just between 0 and 1; the cmap needs to be shared instead of just using the last one.

import numpy as np
from matplotlib.colors import Normalize
import matplotlib.pyplot as plt
import matplotlib.cm as cm
fig, axes = plt.subplots(nrows=2, ncols=2)
cmap=cm.get_cmap('viridis')
normalizer=Normalize(0,4)
im=cm.ScalarMappable(norm=normalizer)
for i,ax in enumerate(axes.flat):
    ax.imshow(i+np.random.random((10,10)),cmap=cmap,norm=normalizer)
    ax.set_title(str(i))
fig.colorbar(im, ax=axes.ravel().tolist())
plt.show()

Use of "this" keyword in C++

It's programmer preference. Personally, I love using this since it explicitly marks the object members. Of course the _ does the same thing (only when you follow the convention)

Setting up MySQL and importing dump within Dockerfile

What I did was download my sql dump in a "db-dump" folder, and mounted it:

mysql:
 image: mysql:5.6
 environment:
   MYSQL_ROOT_PASSWORD: pass
 ports:
   - 3306:3306
 volumes:
   - ./db-dump:/docker-entrypoint-initdb.d

When I run docker-compose up for the first time, the dump is restored in the db.

Android Device not recognized by adb

It may sound silly but in my case the USB cable was too long (even if good quality). It worked with my tablet but not with the phone. To check this, if you run on Linux run lsusb to make sure that your device is at least officially connect to the usb port.

Parse JSON file using GSON

I'm using gson 2.2.3

public class Main {

/**
 * @param args
 * @throws IOException 
 */
public static void main(String[] args) throws IOException {

    JsonReader jsonReader = new JsonReader(new FileReader("jsonFile.json"));

    jsonReader.beginObject();

    while (jsonReader.hasNext()) {

    String name = jsonReader.nextName();
        if (name.equals("descriptor")) {
             readApp(jsonReader);

        }
    }

   jsonReader.endObject();
   jsonReader.close();

}

public static void readApp(JsonReader jsonReader) throws IOException{
    jsonReader.beginObject();
     while (jsonReader.hasNext()) {
         String name = jsonReader.nextName();
         System.out.println(name);
         if (name.contains("app")){
             jsonReader.beginObject();
             while (jsonReader.hasNext()) {
                 String n = jsonReader.nextName();
                 if (n.equals("name")){
                     System.out.println(jsonReader.nextString());
                 }
                 if (n.equals("age")){
                     System.out.println(jsonReader.nextInt());
                 }
                 if (n.equals("messages")){
                     jsonReader.beginArray();
                     while  (jsonReader.hasNext()) {
                          System.out.println(jsonReader.nextString());
                     }
                     jsonReader.endArray();
                 }
             }
             jsonReader.endObject();
         }

     }
     jsonReader.endObject();
}
}

How to scroll table's "tbody" independent of "thead"?

I saw this post about a month ago when I was having similar problems. I needed y-axis scrolling for a table inside of a ui dialog (yes, you heard me right). I was lucky, in that a working solution presented itself fairly quickly. However, it wasn't long before the solution took on a life of its own, but more on that later.

The problem with just setting the top level elements (thead, tfoot, and tbody) to display block, is that browser synchronization of the column sizes between the various components is quickly lost and everything packs to the smallest permissible size. Setting the widths of the columns seems like the best course of action, but without setting the widths of all the internal table components to match the total of these columns, even with a fixed table layout, there is a slight divergence between the headers and body when a scroll bar is present.

The solution for me was to set all the widths, check if a scroll bar was present, and then take the scaled widths the browser had actually decided on, and copy those to the header and footer adjusting the last column width for the size of the scroll bar. Doing this provides some fluidity to the column widths. If changes to the table's width occur, most major browsers will auto-scale the tbody column widths accordingly. All that's left is to set the header and footer column widths from their respective tbody sizes.

$table.find("> thead,> tfoot").find("> tr:first-child")
    .each(function(i,e) {
        $(e).children().each(function(i,e) {
            if (i != column_scaled_widths.length - 1) {
                $(e).width(column_scaled_widths[i] - ($(e).outerWidth() - $(e).width()));
            } else {
                $(e).width(column_scaled_widths[i] - ($(e).outerWidth() - $(e).width()) + $.position.scrollbarWidth());
            }
        });
    });

This fiddle illustrates these notions: http://jsfiddle.net/borgboyone/gbkbhngq/.

Note that a table wrapper or additional tables are not needed for y-axis scrolling alone. (X-axis scrolling does require a wrapping table.) Synchronization between the column sizes for the body and header will still be lost if the minimum pack size for either the header or body columns is encountered. A mechanism for minimum widths should be provided if resizing is an option or small table widths are expected.

The ultimate culmination from this starting point is fully realized here: http://borgboyone.github.io/jquery-ui-table/

A.

Convert char to int in C#

char c = '1';
int i = (int)(c-'0');

and you can create a static method out of it:

static int ToInt(this char c)
{
    return (int)(c - '0');
}

AngularJS 1.2 $injector:modulerr

I have just experienced the same error, in my case it was caused by the second parameter in angular.module being missing- hopefully this may help someone with the same issue.

angular.module('MyApp');

angular.module('MyApp', []);

Use string contains function in oracle SQL query

By lines I assume you mean rows in the table person. What you're looking for is:

select p.name
from   person p
where  p.name LIKE '%A%'; --contains the character 'A'

The above is case sensitive. For a case insensitive search, you can do:

select p.name
from   person p
where  UPPER(p.name) LIKE '%A%'; --contains the character 'A' or 'a'

For the special character, you can do:

select p.name
from   person p
where  p.name LIKE '%'||chr(8211)||'%'; --contains the character chr(8211)

The LIKE operator matches a pattern. The syntax of this command is described in detail in the Oracle documentation. You will mostly use the % sign as it means match zero or more characters.

How do I get extra data from intent on Android?

We can do it by simple means:

In FirstActivity:

Intent intent = new Intent(FirstActivity.this, SecondActivity.class);
intent.putExtra("uid", uid.toString());
intent.putExtra("pwd", pwd.toString());
startActivity(intent);

In SecondActivity:

    try {
        Intent intent = getIntent();

        String uid = intent.getStringExtra("uid");
        String pwd = intent.getStringExtra("pwd");

    } catch (Exception e) {
        e.printStackTrace();
        Log.e("getStringExtra_EX", e + "");
    }

What's the right way to decode a string that has special HTML entities in it?

If you don't want to use html/dom, you could use regex. I haven't tested this; but something along the lines of:

function parseHtmlEntities(str) {
    return str.replace(/&#([0-9]{1,3});/gi, function(match, numStr) {
        var num = parseInt(numStr, 10); // read num as normal number
        return String.fromCharCode(num);
    });
}

[Edit]

Note: this would only work for numeric html-entities, and not stuff like &oring;.

[Edit 2]

Fixed the function (some typos), test here: http://jsfiddle.net/Be2Bd/1/

Highlight Bash/shell code in Markdown files

It depends on the Markdown rendering engine and the Markdown flavour. There is no standard for this. If you mean GitHub flavoured Markdown for example, shell should work fine. Aliases are sh, bash or zsh. You can find the list of available syntax lexers here.

Disable sorting for a particular column in jQuery DataTables

There are two ways, one is defined in html when you define table headers

<thead>
  <th data-orderable="false"></th>
</thead>

Another way is using javascript, for example, you have table

<table id="datatables">
    <thead>
        <tr>
            <th class="testid input">test id</th>
            <th class="testname input">test name</th>
    </thead>
</table>

then,

$(document).ready(function() {
    $('#datatables').DataTable( {
        "columnDefs": [ {
            "targets": [ 0], // 0 indicates the first column you define in <thead>
            "searchable": false
        }
        , {
            // you can also use name to get the target column
            "targets": 'testid', // name is the class you define in <th>
            "searchable": false
        }
        ]
    }
    );
}
);

How to send POST request?

Use requests library to GET, POST, PUT or DELETE by hitting a REST API endpoint. Pass the rest api endpoint url in url, payload(dict) in data and header/metadata in headers

import requests, json

url = "bugs.python.org"

payload = {"number": 12524, 
           "type": "issue", 
           "action": "show"}

header = {"Content-type": "application/x-www-form-urlencoded",
          "Accept": "text/plain"} 

response_decoded_json = requests.post(url, data=payload, headers=header)
response_json = response_decoded_json.json()

print response_json

Asynchronous Process inside a javascript for loop

Any recommendation on how to fix this?

Several. You can use bind:

for (i = 0; i < j; i++) {
    asycronouseProcess(function (i) {
        alert(i);
    }.bind(null, i));
}

Or, if your browser supports let (it will be in the next ECMAScript version, however Firefox already supports it since a while) you could have:

for (i = 0; i < j; i++) {
    let k = i;
    asycronouseProcess(function() {
        alert(k);
    });
}

Or, you could do the job of bind manually (in case the browser doesn't support it, but I would say you can implement a shim in that case, it should be in the link above):

for (i = 0; i < j; i++) {
    asycronouseProcess(function(i) {
        return function () {
            alert(i)
        }
    }(i));
}

I usually prefer let when I can use it (e.g. for Firefox add-on); otherwise bind or a custom currying function (that doesn't need a context object).

How to detect READ_COMMITTED_SNAPSHOT is enabled?

SELECT is_read_committed_snapshot_on FROM sys.databases 
WHERE name= 'YourDatabase'

Return value:

  • 1: READ_COMMITTED_SNAPSHOT option is ON. Read operations under the READ COMMITTED isolation level are based on snapshot scans and do not acquire locks.
  • 0 (default): READ_COMMITTED_SNAPSHOT option is OFF. Read operations under the READ COMMITTED isolation level use Shared (S) locks.

Create a HTML table where each TR is a FORM

I had a problem similar to the one posed in the original question. I was intrigued by the divs styled as table elements (didn't know you could do that!) and gave it a run. However, my solution was to keep my tables wrapped in tags, but rename each input and select option to become the keys of array, which I'm now parsing to get each element in the selected row.

Here's a single row from the table. Note that key [4] is the rendered ID of the row in the database from which this table row was retrieved:

<table>
  <tr>
    <td>DisabilityCategory</td>
    <td><input type="text" name="FormElem[4][ElemLabel]" value="Disabilities"></td>
    <td><select name="FormElem[4][Category]">
        <option value="1">General</option>
        <option value="3">Disability</option>
        <option value="4">Injury</option>
        <option value="2"selected>School</option>
        <option value="5">Veteran</option>
        <option value="10">Medical</option>
        <option value="9">Supports</option>
        <option value="7">Residential</option>
        <option value="8">Guardian</option>
        <option value="6">Criminal</option>
        <option value="11">Contacts</option>
      </select></td>
    <td>4</td>
    <td style="text-align:center;"><input type="text" name="FormElem[4][ElemSeq]" value="0" style="width:2.5em; text-align:center;"></td>
    <td>'ccpPartic'</td>
    <td><input type="text" name="FormElem[4][ElemType]" value="checkbox"></td>
    <td><input type="checkbox" name="FormElem[4][ElemRequired]"></td>
    <td><input type="text" name="FormElem[4][ElemLabelPrefix]" value=""></td>
    <td><input type="text" name="FormElem[4][ElemLabelPostfix]" value=""></td>
    <td><input type="text" name="FormElem[4][ElemLabelPosition]" value="before"></td>
    <td><input type="submit" name="submit[4]" value="Commit Changes"></td>
  </tr>
</table>

Then, in PHP, I'm using the following method to store in an array ($SelectedElem) each of the elements in the row corresponding to the submit button. I'm using print_r() just to illustrate:

$SelectedElem = implode(",", array_keys($_POST['submit']));
print_r ($_POST['FormElem'][$SelectedElem]);

Perhaps this sounds convoluted, but it turned out to be quite simple, and it preserved the organizational structure of the table.

Abstract variables in Java?

As there is no implementation of a variable it can't be abstract ;)

Extract digits from a string in Java

I have finalized the code for phone numbers +9 (987) 124124.

Unicode characters occupy 4 bytes.

public static String stripNonDigitsV2( CharSequence input ) {
    if (input == null)
        return null;
    if ( input.length() == 0 )
        return "";

    char[] result = new char[input.length()];
    int cursor = 0;
    CharBuffer buffer = CharBuffer.wrap( input );
    int i=0;
    while ( i< buffer.length()  ) { //buffer.hasRemaining()
        char chr = buffer.get(i);
        if (chr=='u'){
            i=i+5;
            chr=buffer.get(i);
        }

        if ( chr > 39 && chr < 58 )
            result[cursor++] = chr;
        i=i+1;
    }

    return new String( result, 0, cursor );
}

submit a form in a new tab

<form target="_blank" [....]

will submit the form in a new tab... I am not sure if is this what you are looking for, please explain better...

matplotlib get ylim values

It's an old question, but I don't see mentioned that, depending on the details, the sharey option may be able to do all of this for you, instead of digging up axis limits, margins, etc. There's a demo in the docs that shows how to use sharex, but the same can be done with y-axes.

What is the role of the bias in neural networks?

When you use ANNs, you rarely know about the internals of the systems you want to learn. Some things cannot be learned without a bias. E.g., have a look at the following data: (0, 1), (1, 1), (2, 1), basically a function that maps any x to 1.

If you have a one layered network (or a linear mapping), you cannot find a solution. However, if you have a bias it's trivial!

In an ideal setting, a bias could also map all points to the mean of the target points and let the hidden neurons model the differences from that point.

Random / noise functions for GLSL

After the initial posting of this question in 2010, a lot has changed in the realm of good random functions and hardware support for them.

Looking at the accepted answer from today's perspective, this algorithm is very bad in uniformity of the random numbers drawn from it. And the uniformity suffers a lot depending on the magnitude of the input values and visible artifacts/patterns will become apparent when sampling from it for e.g. ray/path tracing applications.

There have been many different functions (most of them integer hashing) being devised for this task, for different input and output dimensionality, most of which are being evaluated in the 2020 JCGT paper Hash Functions for GPU Rendering. Depending on your needs you could select a function from the list of proposed functions in that paper and simply from the accompanying Shadertoy. One that isn't covered in this paper but that has served me very well without any noticeably patterns on any input magnitude values is also one that I want to highlight.

Other classes of algorithms use low-discrepancy sequences to draw pseudo-random numbers from, such as the Sobol squence with Owen-Nayar scrambling. Eric Heitz has done some amazing research in this area, as well with his A Low-Discrepancy Sampler that Distributes Monte Carlo Errors as a Blue Noise in Screen Space paper. Another example of this is the (so far latest) JCGT paper Practical Hash-based Owen Scrambling, which applies Owen scrambling to a different hash function (namely Laine-Karras).

Yet other classes use algorithms that produce noise patterns with desirable frequency spectrums, such as blue noise, that is particularly "pleasing" to the eyes.

(I realize that good StackOverflow answers should provide the algorithms as source code and not as links because those can break, but there are way too many different algorithms nowadays and I intend for this answer to be a summary of known-good algorithms today)

How to use jQuery in AngularJS

You have to do binding in a directive. Look at this:

angular.module('ng', []).
directive('sliderRange', function($parse, $timeout){
    return {
        restrict: 'A',
        replace: true,
        transclude: false,
        compile: function(element, attrs) {            
            var html = '<div class="slider-range"></div>';
            var slider = $(html);
            element.replaceWith(slider);
            var getterLeft = $parse(attrs.ngModelLeft), setterLeft = getterLeft.assign;
            var getterRight = $parse(attrs.ngModelRight), setterRight = getterRight.assign;

            return function (scope, slider, attrs, controller) {
                var vsLeft = getterLeft(scope), vsRight = getterRight(scope), f = vsLeft || 0, t = vsRight || 10;                        

                var processChange = function() {
                    var vs = slider.slider("values"), f = vs[0], t = vs[1];                                        
                    setterLeft(scope, f);
                    setterRight(scope, t);                    
                }                 
                slider.slider({
                    range: true,
                    min: 0,
                    max: 10,
                    step: 1,
                    change: function() { setTimeout(function () { scope.$apply(processChange); }, 1) }
                }).slider("values", [f, t]);                    
            };            
        }
    };
});

This shows you an example of a slider range, done with jQuery UI. Example usage:

<div slider-range ng-model-left="question.properties.range_from" ng-model-right="question.properties.range_to"></div>

ORA-12528: TNS Listener: all appropriate instances are blocking new connections. Instance "CLRExtProc", status UNKNOWN

set ORACLE_SID=<YOUR_SID>
sqlplus "/as sysdba"
alter system disable restricted session;

or maybe

shutdown abort;

or maybe

lsnrctl stop

lsnrctl start

How to check the Angular version?

Use one of these commands in the terminal (with the Angular CLI installed already):

$ ng --version 

or

$ ng v

But note that depending on the folder you are in, you will get different results.

If you are NOT in an angular project folder, then will see a result like this with no clearly stated Angular: version line, unless referring to the angular core in the package block (as the version) :)

Angular CLI: 11.0.4
Node: 14.15.1
OS: win32 x64

Angular:
...
Ivy Workspace:

Package                      Version
------------------------------------------------------
@angular-devkit/architect    0.1100.4 (cli-only)
@angular-devkit/core         11.0.4 (cli-only)
@angular-devkit/schematics   11.0.4 (cli-only)
@schematics/angular          11.0.4 (cli-only)
@schematics/update           0.1100.4 (cli-only)

And if you run the command IN an angular project folder, you will see a similar result like this with the Angular: 8.2.14 clearly stated (plus some dots).

Angular CLI: 8.3.29
Node: 14.15.1
OS: win32 x64
Angular: 8.2.14
... core

Package                             Version
-------------------------------------------------------------
@angular-devkit/architect           0.803.29
@angular-devkit/core                8.3.29
@angular-devkit/schematics          8.3.29
@angular/cli                        8.3.29
@angular/common                     2.4.10
@angular/compiler                   2.4.10
@angular/compiler-cli               2.4.10
@angular/forms                      2.4.10
@angular/http                       2.4.10
@angular/platform-browser           2.4.10
@angular/router                     3.4.10
...