Programs & Examples On #Xmlschemaset

How do I get a PHP class constructor to call its parent's parent's constructor?

I ended up coming up with an alternative solution that solved the problem.

  • I created an intermediate class that extended Grandpa.
  • Then both Papa and Kiddo extended that class.
  • Kiddo required some intermediate functionality of Papa but didn't like it's constructor so the class has that additional functionality and both extend it.

I've upvoted the other two answers that provided valid yet ugly solutions for an uglier question:)

insert echo into the specific html element like div which has an id or class

Have you tried this?:

    $string = '';
    while($row = mysql_fetch_array($result))
    {
    //this will combine all the results into one string
    $string .= '<img src="'.$row['name'].'" />
                <div>'.$row['name'].'</div>
                <div>'.$row['title'].'</div>
                <div>'.$row['description'].'</div>
                <div>'.$row['link'].'</div><br />';

    //or this will add the individual result in an array
 /*
     $yourHtml[] = $row;
*/
    }

then you echo the $tring to the place you want it to be

<div id="place_here">
   <?php echo $string; ?>
   <?php 
     //or
    /*
      echo '<img src="'.$yourHtml[0]['name'].'" />;//change the index, or you just foreach loop it
    */
    ?>
</div>

Detect click outside element

I create a div at the end of the body like that:

<div v-if="isPopup" class="outside" v-on:click="away()"></div>

Where .outside is :

.outside {
  width: 100vw;
  height: 100vh;
  position: fixed;
  top: 0px;
  left: 0px;
}

And away() is a method in Vue instance :

away() {
 this.isPopup = false;
}

Easy, works well.

Text-decoration: none not working

if you want a nav bar do

ul{ list-style-type: none; } li{text-decoration: none;
  • This will make it want to make the style of the list type to None or nothing

with the < a > tag:

a:link {text-decoration: none}

IF function with 3 conditions

You can do it this way:

=IF(E9>21,"Text 1",IF(AND(E9>=5,E9<=21),"Test 2","Text 3"))

Note I assume you meant >= and <= here since your description skipped the values 5 and 21, but you can adjust these inequalities as needed.

Or you can do it this way:

=IF(E9>21,"Text 1",IF(E9<5,"Text 3","Text 2"))

Mock a constructor with parameter

Starting with version 3.5.0 of Mockito and using the InlineMockMaker, you can now mock object constructions:

 try (MockedConstruction mocked = mockConstruction(A.class)) {
   A a = new A();
   when(a.check()).thenReturn("bar");
 }

Inside the try-with-resources construct all object constructions are returning a mock.

Where is the IIS Express configuration / metabase file found?

To come full circle and include all versions of Visual Studio, @Myster originally stated that;

Pre Visual Studio 2015 the paths to applicationhost.config were:

%userprofile%\documents\iisexpress\config\applicationhost.config
%userprofile%\my documents\iisexpress\config\applicationhost.config

Visual Studio 2015/2017 path can be found at: (credit: @Talon)

$(solutionDir)\.vs\config\applicationhost.config

Visual Studio 2019 path can be found at: (credit: @Talon)

$(solutionDir)\.vs\config\$(ProjectName)\applicationhost.config

But the part that might get some people is that the project settings in the .sln file can repopulate the applicationhost.config for Visual Studio 2015+. (credit: @Lex Li)

So, if you make a change in the applicationhost.config you also have to make sure your changes match here:

$(solutionDir)\ProjectName.sln

The two important settings should look like:

Project("{XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX}") = "ProjectName", "ProjectPath\", "{XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX}"

and

VWDPort = "Port#"

What is important here is that the two settings in the .sln must match the name and bindingInformation respectively in the applicationhost.config file if you plan on making changes. There may be more places that link these two files and I will update as I find more links either by comments or more experience.

How to change the decimal separator of DecimalFormat from comma to dot/point?

This worked for me...

    double num = 10025000;
    new DecimalFormat("#,###.##");
    DecimalFormat df = (DecimalFormat) DecimalFormat.getInstance(Locale.GERMAN);
    System.out.println(df.format(num));

ZIP file content type for HTTP request

[request setValue:@"application/zip" forHTTPHeaderField:@"Content-Type"];

Check if a String is in an ArrayList of Strings

    List list1 = new ArrayList();
    list1.add("one");
    list1.add("three");
    list1.add("four");

    List list2 = new ArrayList();
    list2.add("one");
    list2.add("two");
    list2.add("three");
    list2.add("four");
    list2.add("five");


    list2.stream().filter( x -> !list1.contains(x) ).forEach(x -> System.out.println(x));

The output is:

two
five

How to watch and reload ts-node when TypeScript files change

Here's an alternative to the HeberLZ's answer, using npm scripts.

My package.json:

  "scripts": {
    "watch": "nodemon -e ts -w ./src -x npm run watch:serve",
    "watch:serve": "ts-node --inspect src/index.ts"
  },
  • -e flag sets the extenstions to look for,
  • -w sets the watched directory,
  • -x executes the script.

--inspect in the watch:serve script is actually a node.js flag, it just enables debugging protocol.

Data was not saved: object references an unsaved transient instance - save the transient instance before flushing

To add my 2 cents, I got this same issue when I m accidentally sending null as the ID. Below code depicts my scenario (and anyway OP didn't mention any specific scenario).

Employee emp = new Employee();
emp.setDept(new Dept(deptId)); // -----> when deptId PKID is null, same error will be thrown
// calls to other setters...
em.persist(emp);

Here I m setting the existing department id to a new employee instance without actually getting the department entity first, as I don't want to another select query to fire.

In some scenarios, deptId PKID is coming as null from calling method and I m getting the same error.

So, watch for null values for PK ID

Same answer given here

How to encode a URL in Swift

In my case where the last component was non latin characters I did the following in Swift 2.2:

extension String {
 func encodeUTF8() -> String? {
//If I can create an NSURL out of the string nothing is wrong with it
if let _ = NSURL(string: self) {

    return self
}

//Get the last component from the string this will return subSequence
let optionalLastComponent = self.characters.split { $0 == "/" }.last


if let lastComponent = optionalLastComponent {

    //Get the string from the sub sequence by mapping the characters to [String] then reduce the array to String
    let lastComponentAsString = lastComponent.map { String($0) }.reduce("", combine: +)


    //Get the range of the last component
    if let rangeOfLastComponent = self.rangeOfString(lastComponentAsString) {
        //Get the string without its last component
        let stringWithoutLastComponent = self.substringToIndex(rangeOfLastComponent.startIndex)


        //Encode the last component
        if let lastComponentEncoded = lastComponentAsString.stringByAddingPercentEncodingWithAllowedCharacters(NSCharacterSet.alphanumericCharacterSet()) {


        //Finally append the original string (without its last component) to the encoded part (encoded last component)
        let encodedString = stringWithoutLastComponent + lastComponentEncoded

            //Return the string (original string/encoded string)
            return encodedString
        }
    }
}

return nil;
}
}

SQL to find the number of distinct values in a column

select count(distinct(column_name)) AS columndatacount from table_name where somecondition=true

You can use this query, to count different/distinct data. Thanks

Add CSS3 transition expand/collapse

OMG, I tried to find a simple solution to this for hours. I knew the code was simple but no one provided me what I wanted. So finally got to work on some example code and made something simple that anyone can use no JQuery required. Simple javascript and css and html. In order for the animation to work you have to set the height and width or the animation wont work. Found that out the hard way.

<script>
        function dostuff() {
            if (document.getElementById('MyBox').style.height == "0px") {

                document.getElementById('MyBox').setAttribute("style", "background-color: #45CEE0; height: 200px; width: 200px; transition: all 2s ease;"); 
            }
            else {
                document.getElementById('MyBox').setAttribute("style", "background-color: #45CEE0; height: 0px; width: 0px; transition: all 2s ease;"); 
             }
        }
    </script>
    <div id="MyBox" style="height: 0px; width: 0px;">
    </div>

    <input type="button" id="buttontest" onclick="dostuff()" value="Click Me">

android.os.NetworkOnMainThreadException with android 4.2

Please make sure that you don't do any network access on UI Thread, instead do it in Async Task

The reason why your application crashes on Android versions 3.0 and above, but works fine on Android 2.x is because since HoneyComb are much stricter about abuse against the UI Thread. For example, when an Android device running HoneyComb or above detects a network access on the UI thread, a NetworkOnMainThreadException will be thrown.

See this

Not showing placeholder for input type="date" field

SO what i have decided to do finally is here and its working fine on all mobile browsers including iPhones and Androids.

_x000D_
_x000D_
$(document).ready(function(){_x000D_
_x000D_
  $('input[type="date"]').each(function(e) {_x000D_
    var $el = $(this), _x000D_
        $this_placeholder = $(this).closest('label').find('.custom-placeholder');_x000D_
    $el.on('change',function(){_x000D_
      if($el.val()){_x000D_
        $this_placeholder.text('');_x000D_
      }else {_x000D_
        $this_placeholder.text($el.attr('placeholder'));_x000D_
      }_x000D_
    });_x000D_
  });_x000D_
  _x000D_
});
_x000D_
label {_x000D_
  position: relative;  _x000D_
}_x000D_
.custom-placeholder {_x000D_
    #font > .proxima-nova-light(26px,40px);_x000D_
    position: absolute;_x000D_
    top: 0;_x000D_
    left: 0;_x000D_
    z-index: 10;_x000D_
    color: #999;_x000D_
}
_x000D_
<label>_x000D_
  <input type="date" placeholder="Date">_x000D_
  <span class="custom-placeholder">Date</span>_x000D_
</label>
_x000D_
_x000D_
_x000D_

Date

Error in plot.new() : figure margins too large, Scatter plot

Every time you are creating plots you might get this error - "Error in plot.new() : figure margins too large". To avoid such errors you can first check par("mar") output. You should be getting:

[1] 5.1 4.1 4.1 2.1

To change that write:

par(mar=c(1,1,1,1))

This should rectify the error. Or else you can change the values accordingly.

Hope this works for you.

Call child component method from parent class - Angular

Consider the following example,

    import import { AfterViewInit, ViewChild } from '@angular/core';
    import { Component } from '@angular/core';
    import { CountdownTimerComponent }  from './countdown-timer.component';
    @Component({
        selector: 'app-countdown-parent-vc',
        templateUrl: 'app-countdown-parent-vc.html',
        styleUrl: [app-countdown-parent-vc.css]
    export class CreateCategoryComponent implements OnInit {
         @ViewChild(CountdownTimerComponent, {static: false})
         private timerComponent: CountdownTimerComponent;
         ngAfterViewInit() {
             this.timerComponent.startTimer();
         }

         submitNewCategory(){
            this.ngAfterViewInit();     
         }

Read more about @ViewChild here.

Java generics - why is "extends T" allowed but not "implements T"?

We are used to

class ClassTypeA implements InterfaceTypeA {}
class ClassTypeB extends ClassTypeA {}

and any slight deviation from these rules greatly confuses us.

The syntax of a type bound is defined as

TypeBound:
    extends TypeVariable 
    extends ClassOrInterfaceType {AdditionalBound}

(JLS 12 > 4.4. Type Variables > TypeBound)

If we were to change it, we would surely add the implements case

TypeBound:
    extends TypeVariable 
    extends ClassType {AdditionalBound}
    implements InterfaceType {AdditionalBound}

and end up with two identically processed clauses

ClassOrInterfaceType:
    ClassType 
    InterfaceType

(JLS 12 > 4.3. Reference Types and Values > ClassOrInterfaceType)

except we would also need to take care of implements, which would complicate things further.

I believe it's the main reason why extends ClassOrInterfaceType is used instead of extends ClassType and implements InterfaceType - to keep things simple within the complicated concept. The problem is we don't have the right word to cover both extends and implements and we definitely don't want to introduce one.

<T is ClassTypeA>
<T is InterfaceTypeA>

Although extends brings some mess when it goes along with an interface, it's a broader term and it can be used to describe both cases. Try to tune your mind to the concept of extending a type (not extending a class, not implementing an interface). You restrict a type parameter by another type and it doesn't matter what that type actually is. It only matters that it's its upper bound and it's its supertype.

Generate a random number in the range 1 - 10

(trunc(random() * 10) % 10) + 1

highlight the navigation menu for the current page

CSS:

.topmenu ul li.active a, .topmenu ul li a:hover {
    text-decoration:none;
    color:#fff;
    background:url(../images/menu_a.jpg) no-repeat center top;
}

JavaScript:

<script src="JavaScript/jquery-1.10.2.js" type="text/javascript"></script> 

<script type="text/javascript">
    $(function() {
        // this will get the full URL at the address bar
        var url = window.location.href;

        // passes on every "a" tag
        $(".topmenu a").each(function() {
            // checks if its the same on the address bar
            if (url == (this.href)) {
                $(this).closest("li").addClass("active");
                //for making parent of submenu active
               $(this).closest("li").parent().parent().addClass("active");
            }
        });
    });        
</script>

Html Code:

<div class="topmenu">
    <ul>
        <li><a href="Default.aspx">Home</a></li>
        <li><a href="NewsLetter.aspx">Newsletter</a></li>
        <li><a href="#">Forms</a></li>
        <li><a href="#">Mail</a></li>
        <li><a href="#">Service</a></li>
        <li style="border:none;"><a href="#">HSE</a></li>
        <li><a href="#">MainMenu2</a>
           <ul>
              <li>submenu1</li>
              <li>submenu2</li>
              <li>submenu3</li>
          </ul>
       </li>
    </ul>
</div>

Best way to change font colour halfway through paragraph?

wrap a <span> around those words and style with the appropriate color

now is the time for <span style='color:orange'>all good men</span> to come to the

Git diff says subproject is dirty

A submodule may be marked as dirty if filemode settings is enabled and you changed file permissions in submodule subtree.

To disable filemode in a submodule, you can edit /.git/modules/path/to/your/submodule/config and add

[core]
  filemode = false

If you want to ignore all dirty states, you can either set ignore = dirty property in /.gitmodules file, but I think it's better to only disable filemode.

How do I debug Windows services in Visual Studio?

In the OnStart method, do the following.

protected override void OnStart(string[] args)
{
    try
    {
        RequestAdditionalTime(600000);
        System.Diagnostics.Debugger.Launch(); // Put breakpoint here.

        .... Your code
    }
    catch (Exception ex)
    {
        .... Your exception code
    }
}

Then run a command prompt as administrator and put in the following:

c:\> sc create test-xyzService binPath= <ProjectPath>\bin\debug\service.exe type= own start= demand

The above line will create test-xyzService in the service list.

To start the service, this will prompt you to attach to debut in Visual Studio or not.

c:\> sc start text-xyzService

To stop the service:

c:\> sc stop test-xyzService

To delete or uninstall:

c:\> sc delete text-xyzService

How to clone git repository with specific revision/changeset?

git clone https://github.com/ORGANIZATION/repository.git (clone the repository)

cd repository (navigate to the repository)

git fetch origin 2600f4f928773d79164964137d514b85400b09b2

git checkout FETCH_HEAD

How do I set the figure title and axes labels font size in Matplotlib?

If you're more used to using ax objects to do your plotting, you might find the ax.xaxis.label.set_size() easier to remember, or at least easier to find using tab in an ipython terminal. It seems to need a redraw operation after to see the effect. For example:

import matplotlib.pyplot as plt

# set up a plot with dummy data
fig, ax = plt.subplots()
x = [0, 1, 2]
y = [0, 3, 9]
ax.plot(x,y)

# title and labels, setting initial sizes
fig.suptitle('test title', fontsize=12)
ax.set_xlabel('xlabel', fontsize=10)
ax.set_ylabel('ylabel', fontsize='medium')   # relative to plt.rcParams['font.size']

# setting label sizes after creation
ax.xaxis.label.set_size(20)
plt.draw()

I don't know of a similar way to set the suptitle size after it's created.

Transition color fade on hover?

For having a trasition effect like a highlighter just to highlight the text and fade off the bg color, we used the following:

_x000D_
_x000D_
.field-error {_x000D_
    color: #f44336;_x000D_
    padding: 2px 5px;_x000D_
    position: absolute;_x000D_
    font-size: small;_x000D_
    background-color: white;_x000D_
}_x000D_
_x000D_
.highlighter {_x000D_
    animation: fadeoutBg 3s; /***Transition delay 3s fadeout is class***/_x000D_
    -moz-animation: fadeoutBg 3s; /* Firefox */_x000D_
    -webkit-animation: fadeoutBg 3s; /* Safari and Chrome */_x000D_
    -o-animation: fadeoutBg 3s; /* Opera */_x000D_
}_x000D_
_x000D_
@keyframes fadeoutBg {_x000D_
    from { background-color: lightgreen; } /** from color **/_x000D_
    to { background-color: white; } /** to color **/_x000D_
}_x000D_
_x000D_
@-moz-keyframes fadeoutBg { /* Firefox */_x000D_
    from { background-color: lightgreen; }_x000D_
    to { background-color: white; }_x000D_
}_x000D_
_x000D_
@-webkit-keyframes fadeoutBg { /* Safari and Chrome */_x000D_
    from { background-color: lightgreen; }_x000D_
    to { background-color: white; }_x000D_
}_x000D_
_x000D_
@-o-keyframes fadeoutBg { /* Opera */_x000D_
    from { background-color: lightgreen; }_x000D_
    to { background-color: white; }_x000D_
}
_x000D_
<div class="field-error highlighter">File name already exists.</div>
_x000D_
_x000D_
_x000D_

nginx error connect to php5-fpm.sock failed (13: Permission denied)

I had a similar error after php update. PHP fixed a security bug where o had rw permission to the socket file.

  1. Open /etc/php5/fpm/pool.d/www.conf or /etc/php/7.0/fpm/pool.d/www.conf, depending on your version.
  2. Uncomment all permission lines, like:

    listen.owner = www-data
    listen.group = www-data
    listen.mode = 0660
    
  3. Restart fpm - sudo service php5-fpm restart or sudo service php7.0-fpm restart

Note: if your webserver runs as user other than www-data, you will need to update the www.conf file accordingly

Set max-height on inner div so scroll bars appear, but not on parent div

This would work just fine, set the height to desired pixel

#inner-right{
            height: 100px;
            overflow:auto;
            }

Easiest way to convert int to string in C++

char * bufSecs = new char[32];
char * bufMs = new char[32];
sprintf(bufSecs, "%d", timeStart.elapsed()/1000);
sprintf(bufMs, "%d", timeStart.elapsed()%1000);

how to use Blob datatype in Postgres

I think this is the most comprehensive answer on the PostgreSQL wiki itself: https://wiki.postgresql.org/wiki/BinaryFilesInDB

Read the part with the title 'What is the best way to store the files in the Database?'

SQL Query to add a new column after an existing column in SQL Server 2005

ALTER won't do it because column order does not matter for storage or querying

If SQL Server, you'd have to use the SSMS Table Designer to arrange your columns, which can then generate a script which drops and recreates the table

Edit Jun 2013

Cross link to my answer here: Performance / Space implications when ordering SQL Server columns?

Make view 80% width of parent in React Native

You can also try react-native-extended-stylesheet that supports percentage for single-orientation apps:

import EStyleSheet from 'react-native-extended-stylesheet';

const styles = EStyleSheet.create({
  column: {
    width: '80%',
    height: '50%',
    marginLeft: '10%'
  }
});

How to install plugin for Eclipse from .zip

My .zip file was formatted correctly (I think) but it wasn't working. Even unchecking "Group items by category" didn't work

To install it I did so:

  • unzip the .zip archive
  • Help -> Install New Software...
  • Add... -> Archive...
  • I selected the "content.jar" file

At this point Eclipse read the plugin correctly, I went ahead, accepted the conditions and then asked me to restart the IDE.

System.BadImageFormatException: Could not load file or assembly

Try to configure the setting of your projects, it is usually due to x86/x64 architecture problems:

Go and set your choice as shown:

How to Edit a row in the datatable

First you need to find a row with id == 2 then change the name so:

foreach(DataRow dr in table.Rows) // search whole table
{
    if(dr["Product_id"] == 2) // if id==2
    {
        dr["Product_name"] = "cde"; //change the name
        //break; break or not depending on you
    }
}

You could also try these solutions:

table.Rows[1]["Product_name"] = "cde" // not recommended as it selects 2nd row as I know that it has id 2

Or:

DataRow dr = table.Select("Product_id=2").FirstOrDefault(); // finds all rows with id==2 and selects first or null if haven't found any
if(dr != null)
{
    dr["Product_name"] = "cde"; //changes the Product_name
}

Switch case in C# - a constant value is expected

Now you can use nameof:

public static void Output<T>(IEnumerable<T> dataSource) where T : class
{
    string dataSourceName = typeof(T).Name;
    switch (dataSourceName)
    {
        case nameof(CustomerDetails):
            var t = 123;
            break;
        default:
            Console.WriteLine("Test");
    }
}

nameof(CustomerDetails) is basically identical to the string literal "CustomerDetails", but with a compile-time check that it refers to some symbol (to prevent a typo).

nameof appeared in C# 6.0, so after this question was asked.

jQuery get input value after keypress

This is because keypress events are fired before the new character is added to the value of the element (so the first keypress event is fired before the first character is added, while the value is still empty). You should use keyup instead, which is fired after the character has been added.

Note that, if your element #dSuggest is the same as input:text[name=dSuggest] you can simplify this code considerably (and if it isn't, having an element with a name that is the same as the id of another element is not a good idea).

$('#dSuggest').keypress(function() {
    var dInput = this.value;
    console.log(dInput);
    $(".dDimension:contains('" + dInput + "')").css("display","block");
});

.htaccess: where is located when not in www base dir

The .htaccess is either in the root-directory of your webpage or in the directory you want to protect.

Make sure to make them visible in your filesystem, because AFAIK (I'm no unix expert either) files starting with a period are invisible by default on unix-systems.

Object of class mysqli_result could not be converted to string in

Try with:

$row = mysqli_fetch_assoc($result);
echo "my result <a href='data/" . htmlentities($row['classtype'], ENT_QUOTES, 'UTF-8') . ".php'>My account</a>";

Setting selected values for ng-options bound select elements

If using AngularJS 1.2 you can use 'track by' to tell Angular how to compare objects.

<select 
    ng-model="Choice.SelectedOption"                 
    ng-options="choice.Name for choice in Choice.Options track by choice.ID">
</select>

Updated fiddle http://jsfiddle.net/gFCzV/34/

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

How to set maximum fullscreen in vmware?

It sounds to me as if you actually mean "linux guests" and not "linux hosts".

But in any case, I suspect you did not install the VMWare Tools: doubleclick on that icon on the Desktop that can be seen on your screenshot. It will install some drivers that communicate with VMWare that, among other things, allow to adjust the screen resolution dynamically.

When the installation process is finished, you'll most likely have to reboot the VM.

How to plot a subset of a data frame in R?

This is how I would do it, in order to get in the var4 restriction:

dfr<-data.frame(var1=rnorm(100), var2=rnorm(100), var3=rnorm(100, 160, 10), var4=rnorm(100, 27, 6))
plot( subset( dfr, var3 < 155 & var4 > 27, select = c( var1, var2 ) ) )

Rgds, Rainer

TSQL CASE with if comparison in SELECT statement

Please select the same in the outer select. You can't access the alias name in the same query.

SELECT *, (CASE
        WHEN articleNumber < 2 THEN 'Ama'
        WHEN articleNumber < 5 THEN 'SemiAma' 
        WHEN articleNumber < 7 THEN 'Good'  
        WHEN articleNumber < 9 THEN 'Better' 
        WHEN articleNumber < 12 THEN 'Best'
        ELSE 'Outstanding'
        END) AS ranking 
FROM(
    SELECT registrationDate, (SELECT COUNT(*) FROM Articles WHERE Articles.userId = Users.userId) as articleNumber, 
    hobbies, etc...
    FROM USERS
)x

How to exit git log or git diff

The END comes from the pager used to display the log (your are at that moment still inside it). Type q to exit it.

Removing viewcontrollers from navigation stack

Swift 3 & 4/5

self.navigationController!.viewControllers.removeAll()

self.navigationController?.viewControllers.remove(at: "insert here a number")

Swift 2.1

remove all:

self.navigationController!.viewControllers.removeAll()

remove at index

self.navigationController?.viewControllers.removeAtIndex("insert here a number")

There a bunch of more possible actions like removeFirst,range etc.

Log all requests from the python-requests module

For those using python 3+

import requests
import logging
import http.client

http.client.HTTPConnection.debuglevel = 1

logging.basicConfig()
logging.getLogger().setLevel(logging.DEBUG)
requests_log = logging.getLogger("requests.packages.urllib3")
requests_log.setLevel(logging.DEBUG)
requests_log.propagate = True

pandas: best way to select all columns whose names start with X

Based on @EdChum's answer, you can try the following solution:

df[df.columns[pd.Series(df.columns).str.contains("foo")]]

This will be really helpful in case not all the columns you want to select start with foo. This method selects all the columns that contain the substring foo and it could be placed in at any point of a column's name.

In essence, I replaced .startswith() with .contains().

How can I turn a JSONArray into a JSONObject?

I have JSONObject like this: {"status":[{"Response":"success"}]}.

If I want to convert the JSONObject value, which is a JSONArray into JSONObject automatically without using any static value, here is the code for that.

JSONArray array=new JSONArray();
JSONObject obj2=new JSONObject();
obj2.put("Response", "success");
array.put(obj2);
JSONObject obj=new JSONObject();
obj.put("status",array);

Converting the JSONArray to JSON Object:

Iterator<String> it=obj.keys();
        while(it.hasNext()){
String keys=it.next();
JSONObject innerJson=new JSONObject(obj.toString());
JSONArray innerArray=innerJson.getJSONArray(keys);
for(int i=0;i<innerArray.length();i++){
JSONObject innInnerObj=innerArray.getJSONObject(i);
Iterator<String> InnerIterator=innInnerObj.keys();
while(InnerIterator.hasNext()){
System.out.println("InnInnerObject value is :"+innInnerObj.get(InnerIterator.next()));


 }
}

Setting onSubmit in React.js

In your doSomething() function, pass in the event e and use e.preventDefault().

doSomething = function (e) {
    alert('it works!');
    e.preventDefault();
}

str_replace with array

If the text is a simple markup and has existing anchors, stage the existing anchor tags first, swap out the urls, then replace the staged markers.

$text = '
Lorem Ipsum is simply dummy text found by searching http://google.com/?q=lorem in your <a href=https://www.mozilla.org/en-US/firefox/>Firefox</a>,
<a href="https://www.apple.com/safari/">Safari</a>, or https://www.google.com/chrome/ browser.

Link replacements will first stage existing anchor tags, replace each with a marker, then swap out the remaining links.
Links should be properly encoded.  If links are not separated from surrounding content like a trailing "." period then they it will be included in the link.
Links that are not encoded properly may create a problem, so best to use this when you know the text you are processing is not mixed HTML.

Example: http://google.com/i,m,complicate--d/index.html
Example: https://www.google.com/chrome/?123&t=123
Example: http://google.com/?q='. urlencode('<a href="http://google.com">http://google.com</a>') .'
';

// Replace existing links with a marker
$linkStore = array();
$text = preg_replace_callback('/(<a.*?a>)/', function($match) use (&$linkStore){ $key = '__linkStore'.count($linkStore).'__'; $linkStore[$key] = $match[0]; return $key; }, $text);

// Replace remaining URLs with an anchor tag
$text = preg_replace_callback("/(http|https|ftp|ftps)\:\/\/[a-zA-Z0-9\-\.]+\.[a-zA-Z]{2,3}(\/\S*)?/", function($match) use (&$linkStore){ return '<a href="'. $match[0] .'">'. $match[0] .'</a>'; }, $text);

// Replace link markers with original
$text = str_replace(array_keys($linkStore), array_values($linkStore), $text);

echo '<pre>'.$text;

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

I use the following:

Function GetProgramOutput([string]$exe, [string]$arguments)
{
    $process = New-Object -TypeName System.Diagnostics.Process
    $process.StartInfo.FileName = $exe
    $process.StartInfo.Arguments = $arguments
    
    $process.StartInfo.UseShellExecute = $false
    $process.StartInfo.RedirectStandardOutput = $true
    $process.StartInfo.RedirectStandardError = $true
    $process.Start()
    
    $output = $process.StandardOutput.ReadToEnd()   
    $err = $process.StandardError.ReadToEnd()
    
    $process.WaitForExit()
    
    $output
    $err
}
    
$exe = "C:\Program Files\7-Zip\7z.exe"
$arguments = "i"
    
$runResult = (GetProgramOutput $exe $arguments)
$stdout = $runResult[-2]
$stderr = $runResult[-1]
    
[System.Console]::WriteLine("Standard out: " + $stdout)
[System.Console]::WriteLine("Standard error: " + $stderr)

postgres: upgrade a user to be a superuser?

To expand on the above and make a quick reference:

  • To make a user a SuperUser: ALTER USER username WITH SUPERUSER;
  • To make a user no longer a SuperUser: ALTER USER username WITH NOSUPERUSER;
  • To just allow the user to create a database: ALTER USER username CREATEDB;

You can also use CREATEROLE and CREATEUSER to allow a user privileges without making them a superuser.

Documentation

How do I merge my local uncommitted changes into another Git branch?

A shorter alternative to the previously mentioned stash approach would be:

Temporarily move the changes to a stash.

  1. git stash

Create and switch to a new branch and then pop the stash to it in just one step.

  1. git stash branch new_branch_name

Then just add and commit the changes to this new branch.

How to get selected value of a dropdown menu in ReactJS

As for front-end developer many time we are dealing with the forms in which we have to handle the dropdowns and we have to use the value of selected dropdown to perform some action or the send the value on the Server, it's very simple you have to write the simple dropdown in HTML just put the one onChange method for the selection in the dropdown whenever user change the value of dropdown set that value to state so you can easily access it in AvFeaturedPlayList 1 remember you will always get the result as option value and not the dropdown text which is displayed on the screen

import React, { Component } from "react";
import { Server } from "net";

class InlineStyle extends Component {
  constructor(props) {
    super(props);
    this.state = {
      selectValue: ""
    };

    this.handleDropdownChange = this.handleDropdownChange.bind(this);
  }

  handleDropdownChange(e) {
    this.setState({ selectValue: e.target.value });
  }

  render() {
    return (
      <div>
        <div>
          <div>
            <select id="dropdown" onChange={this.handleDropdownChange}>
              <option value="N/A">N/A</option>
              <option value="1">1</option>
              <option value="2">2</option>
              <option value="3">3</option>
              <option value="4">4</option>
            </select>
          </div>

          <div>Selected value is : {this.state.selectValue}</div>
        </div>
      </div>
    );
  }
}
export default InlineStyle;

java.lang.UnsupportedClassVersionError

Another option is to delete all the classes and rebuild. Having build file is an ideal solution to control whole process like compilation, packaging and deployment. You can also specify source/target versions

Creating an array from a text file in Bash

Use the mapfile command:

mapfile -t myArray < file.txt

The error is using for -- the idiomatic way to loop over lines of a file is:

while IFS= read -r line; do echo ">>$line<<"; done < file.txt

See BashFAQ/005 for more details.

Fixing "Lock wait timeout exceeded; try restarting transaction" for a 'stuck" Mysql table?

issue resolved in my case by changing delete to truncate

issue- query:

delete from Survey1.sr_survey_generic_details
mycursor.execute(query)

fix- query:

truncate table Survey1.sr_survey_generic_details
mycursor.execute(query)

Casting variables in Java

Suppose you wanted to cast a String to a File (yes it does not make any sense), you cannot cast it directly because the File class is not a child and not a parent of the String class (and the compiler complains).

But you could cast your String to Object, because a String is an Object (Object is parent). Then you could cast this object to a File, because a File is an Object.

So all you operations are 'legal' from a typing point of view at compile time, but it does not mean that it will work at runtime !

File f = (File)(Object) "Stupid cast";

The compiler will allow this even if it does not make sense, but it will crash at runtime with this exception:

Exception in thread "main" java.lang.ClassCastException:
    java.lang.String cannot be cast to java.io.File

Printing chars and their ASCII-code in C

This reads a line of text from standard input and prints out the characters in the line and their ASCII codes:

#include <stdio.h>

void printChars(void)
{
    unsigned char   line[80+1];
    int             i;

    // Read a text line
    if (fgets(line, 80, stdin) == NULL)
        return;

    // Print the line chars
    for (i = 0;  line[i] != '\n';  i++)
    {
        int     ch;

        ch = line[i];
        printf("'%c' %3d 0x%02X\n", ch, ch, (unsigned)ch);
    }
}

Filtering DataGridView without changing datasource

//"Comment" Filter datagrid without changing dataset,Perfectly works.

            (dg.ItemsSource as ListCollectionView).Filter = (d) =>
            {
                DataRow myRow = ((System.Data.DataRowView)(d)).Row;
                if (myRow["FName"].ToString().ToUpper().Contains(searchText.ToString().ToUpper()) || myRow["LName"].ToString().ToUpper().Contains(searchText.ToString().ToUpper()))
                    return true; //if want to show in grid
                return false;    //if don't want to show in grid
            };         

Assign a synthesizable initial value to a reg in Verilog

The other answers are all good. For Xilinx FPGA designs, it is best not to use global reset lines, and use initial blocks for reset conditions for most logic. Here is the white paper from Ken Chapman (Xilinx FPGA guru)

http://japan.xilinx.com/support/documentation/white_papers/wp272.pdf

Returning value that was passed into a method

Even more useful, if you have multiple parameters you can access any/all of them with:

_mock.Setup(x => x.DoSomething(It.IsAny<string>(),It.IsAny<string>(),It.IsAny<string>())
     .Returns((string a, string b, string c) => string.Concat(a,b,c));

You always need to reference all the arguments, to match the method's signature, even if you're only going to use one of them.

How to grep Git commit diffs or contents for a certain word?

git log's pickaxe will find commits with changes including "word" with git log -Sword

Creating a blocking Queue<T> in .NET?

I haven't fully explored the TPL but they might have something that fits your needs, or at the very least, some Reflector fodder to snag some inspiration from.

Hope that helps.

Find number of decimal places in decimal value regardless of culture

I used Joe's way to solve this issue :)

decimal argument = 123.456m;
int count = BitConverter.GetBytes(decimal.GetBits(argument)[3])[2];

String length in bytes in JavaScript

Here is a much faster version, which doesn't use regular expressions, nor encodeURIComponent():

function byteLength(str) {
  // returns the byte length of an utf8 string
  var s = str.length;
  for (var i=str.length-1; i>=0; i--) {
    var code = str.charCodeAt(i);
    if (code > 0x7f && code <= 0x7ff) s++;
    else if (code > 0x7ff && code <= 0xffff) s+=2;
    if (code >= 0xDC00 && code <= 0xDFFF) i--; //trail surrogate
  }
  return s;
}

Here is a performance comparison.

It just computes the length in UTF8 of each unicode codepoints returned by charCodeAt() (based on wikipedia's descriptions of UTF8, and UTF16 surrogate characters).

It follows RFC3629 (where UTF-8 characters are at most 4-bytes long).

SQL JOIN - WHERE clause vs. ON clause

In terms of the optimizer, it shouldn't make a difference whether you define your join clauses with ON or WHERE.

However, IMHO, I think it's much clearer to use the ON clause when performing joins. That way you have a specific section of you query that dictates how the join is handled versus intermixed with the rest of the WHERE clauses.

How can I check that JButton is pressed? If the isEnable() is not work?

Seems you need to use JToggleButton :

JToggleButton tb = new JToggleButton("push me");
tb.addActionListener(new ActionListener() {

    @Override
    public void actionPerformed(ActionEvent e) {
        JToggleButton btn =  (JToggleButton) e.getSource();
        btn.setText(btn.isSelected() ? "pushed" : "push me");
    }
});

Difference between $(this) and event.target?

this is a reference for the DOM element for which the event is being handled (the current target). event.target refers to the element which initiated the event. They were the same in this case, and can often be, but they aren't necessarily always so.

You can get a good sense of this by reviewing the jQuery event docs, but in summary:

event.currentTarget

The current DOM element within the event bubbling phase.

event.delegateTarget

The element where the currently-called jQuery event handler was attached.

event.relatedTarget

The other DOM element involved in the event, if any.

event.target

The DOM element that initiated the event.

To get the desired functionality using jQuery, you must wrap it in a jQuery object using either: $(this) or $(evt.target).

The .attr() method only works on a jQuery object, not on a DOM element. $(evt.target).attr('href') or simply evt.target.href will give you what you want.

Android Webview - Webpage should fit the device screen

Making Changes to the answer by danh32 since the display.getWidth(); is now deprecated.

private int getScale(){
    Point p = new Point();
    Display display = ((WindowManager) getSystemService(Context.WINDOW_SERVICE)).getDefaultDisplay(); 
    display.getSize(p);
    int width = p.x; 
    Double val = new Double(width)/new Double(PIC_WIDTH);
    val = val * 100d;
    return val.intValue();
}

Then use

WebView web = new WebView(this);
web.setPadding(0, 0, 0, 0);
web.setInitialScale(getScale());

PHP Redirect to another page after form submit

You can include your header function wherever you like, as long as NO html and/or text has been printed to standard out.

For more information and usage: http://php.net/manual/en/function.header.php


I see in your code that you echo() out some text in case of error or success. Don't do that: you can't. You can only redirect OR show the text. If you show the text you'll then fail to redirect.

How do I append one string to another in Python?

Basically, no difference. The only consistent trend is that Python seems to be getting slower with every version... :(


List

%%timeit
x = []
for i in range(100000000):  # xrange on Python 2.7
    x.append('a')
x = ''.join(x)

Python 2.7

1 loop, best of 3: 7.34 s per loop

Python 3.4

1 loop, best of 3: 7.99 s per loop

Python 3.5

1 loop, best of 3: 8.48 s per loop

Python 3.6

1 loop, best of 3: 9.93 s per loop


String

%%timeit
x = ''
for i in range(100000000):  # xrange on Python 2.7
    x += 'a'

Python 2.7:

1 loop, best of 3: 7.41 s per loop

Python 3.4

1 loop, best of 3: 9.08 s per loop

Python 3.5

1 loop, best of 3: 8.82 s per loop

Python 3.6

1 loop, best of 3: 9.24 s per loop

How to check if any fields in a form are empty in php

Specify POST method in form
<form name="registrationform" action="register.php" method="post">


your form code

</form>

Convert Mongoose docs to json

You can use res.json() to jsonify any object. lean() will remove all the empty fields in the mongoose query.

UserModel.find().lean().exec(function (err, users) { return res.json(users); }

Print in Landscape format

you cannot set this in javascript, you have to do this with html/css:

<style type="text/css" media="print">
  @page { size: landscape; }
</style>

EDIT: See this Question and the accepted answer for more information on browser support: Is @Page { size:landscape} obsolete?

Copying Code from Inspect Element in Google Chrome

Right click on the particular element (e.g. div, table, td) and select the copy as html.

set initial viewcontroller in appdelegate - swift

If you're not using the storyboard. You can initialize your main view controller programmatically.

Swift 4

func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool {

    let rootViewController = MainViewController()
    let navigationController = UINavigationController(rootViewController: rootViewController)
    self.window = UIWindow(frame: UIScreen.main.bounds)
    self.window?.rootViewController = navigationController
    self.window?.makeKeyAndVisible()

    return true
}
class MainViewController: UIViewController {

    override func viewDidLoad() {
        super.viewDidLoad()

        view.backgroundColor = .green
    }
}

And also remove Main from Deployment Info.

enter image description here

QComboBox - set selected item based on the item's data

You can also have a look at the method findText(const QString & text) from QComboBox; it returns the index of the element which contains the given text, (-1 if not found). The advantage of using this method is that you don't need to set the second parameter when you add an item.

Here is a little example :

/* Create the comboBox */
QComboBox   *_comboBox = new QComboBox;

/* Create the ComboBox elements list (here we use QString) */
QList<QString> stringsList;
stringsList.append("Text1");
stringsList.append("Text3");
stringsList.append("Text4");
stringsList.append("Text2");
stringsList.append("Text5");

/* Populate the comboBox */
_comboBox->addItems(stringsList);

/* Create the label */
QLabel *label = new QLabel;

/* Search for "Text2" text */
int index = _comboBox->findText("Text2");
if( index == -1 )
    label->setText("Text2 not found !");
else
    label->setText(QString("Text2's index is ")
                   .append(QString::number(_comboBox->findText("Text2"))));

/* setup layout */
QVBoxLayout *layout = new QVBoxLayout(this);
layout->addWidget(_comboBox);
layout->addWidget(label);

How to overlay images

All we want is parent above child. This is how you do it.

You put img into span, set z-index & position for both elements, and extra display for span. Add hover to span so you can test it and you got it!

HTML:

<span><img src="/images/"></span>

CSS

span img {
    position:relative;
    z-index:-1;
}
span {
    position:relative;
    z-index:initial;
    display:inline-block;
}
span:hover {
    background-color:#000;
}

Creating a "Hello World" WebSocket example

I couldnt find a simple working example anywhere (as of Jan 19), so here is an updated version. I have chrome version 71.0.3578.98.

C# Websocket server :

using System;
using System.Text;
using System.Net;
using System.Net.Sockets;
using System.Security.Cryptography;

namespace WebSocketServer
{
    class Program
    {
    static Socket serverSocket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.IP);
    static private string guid = "258EAFA5-E914-47DA-95CA-C5AB0DC85B11";

    static void Main(string[] args)
    {
        serverSocket.Bind(new IPEndPoint(IPAddress.Any, 8080));
        serverSocket.Listen(1); //just one socket
        serverSocket.BeginAccept(null, 0, OnAccept, null);
        Console.Read();
    }

    private static void OnAccept(IAsyncResult result)
    {
        byte[] buffer = new byte[1024];
        try
        {
            Socket client = null;
            string headerResponse = "";
            if (serverSocket != null && serverSocket.IsBound)
            {
                client = serverSocket.EndAccept(result);
                var i = client.Receive(buffer);
                headerResponse = (System.Text.Encoding.UTF8.GetString(buffer)).Substring(0, i);
                // write received data to the console
                Console.WriteLine(headerResponse);
                Console.WriteLine("=====================");
            }
            if (client != null)
            {
                /* Handshaking and managing ClientSocket */
                var key = headerResponse.Replace("ey:", "`")
                          .Split('`')[1]                     // dGhlIHNhbXBsZSBub25jZQ== \r\n .......
                          .Replace("\r", "").Split('\n')[0]  // dGhlIHNhbXBsZSBub25jZQ==
                          .Trim();

                // key should now equal dGhlIHNhbXBsZSBub25jZQ==
                var test1 = AcceptKey(ref key);

                var newLine = "\r\n";

                var response = "HTTP/1.1 101 Switching Protocols" + newLine
                     + "Upgrade: websocket" + newLine
                     + "Connection: Upgrade" + newLine
                     + "Sec-WebSocket-Accept: " + test1 + newLine + newLine
                     //+ "Sec-WebSocket-Protocol: chat, superchat" + newLine
                     //+ "Sec-WebSocket-Version: 13" + newLine
                     ;

                client.Send(System.Text.Encoding.UTF8.GetBytes(response));
                var i = client.Receive(buffer); // wait for client to send a message
                string browserSent = GetDecodedData(buffer, i);
                Console.WriteLine("BrowserSent: " + browserSent);

                Console.WriteLine("=====================");
                //now send message to client
                client.Send(GetFrameFromString("This is message from server to client."));
                System.Threading.Thread.Sleep(10000);//wait for message to be sent
            }
        }
        catch (SocketException exception)
        {
            throw exception;
        }
        finally
        {
            if (serverSocket != null && serverSocket.IsBound)
            {
                serverSocket.BeginAccept(null, 0, OnAccept, null);
            }
        }
    }

    public static T[] SubArray<T>(T[] data, int index, int length)
    {
        T[] result = new T[length];
        Array.Copy(data, index, result, 0, length);
        return result;
    }

    private static string AcceptKey(ref string key)
    {
        string longKey = key + guid;
        byte[] hashBytes = ComputeHash(longKey);
        return Convert.ToBase64String(hashBytes);
    }

    static SHA1 sha1 = SHA1CryptoServiceProvider.Create();
    private static byte[] ComputeHash(string str)
    {
        return sha1.ComputeHash(System.Text.Encoding.ASCII.GetBytes(str));
    }

    //Needed to decode frame
    public static string GetDecodedData(byte[] buffer, int length)
    {
        byte b = buffer[1];
        int dataLength = 0;
        int totalLength = 0;
        int keyIndex = 0;

        if (b - 128 <= 125)
        {
            dataLength = b - 128;
            keyIndex = 2;
            totalLength = dataLength + 6;
        }

        if (b - 128 == 126)
        {
            dataLength = BitConverter.ToInt16(new byte[] { buffer[3], buffer[2] }, 0);
            keyIndex = 4;
            totalLength = dataLength + 8;
        }

        if (b - 128 == 127)
        {
            dataLength = (int)BitConverter.ToInt64(new byte[] { buffer[9], buffer[8], buffer[7], buffer[6], buffer[5], buffer[4], buffer[3], buffer[2] }, 0);
            keyIndex = 10;
            totalLength = dataLength + 14;
        }

        if (totalLength > length)
            throw new Exception("The buffer length is small than the data length");

        byte[] key = new byte[] { buffer[keyIndex], buffer[keyIndex + 1], buffer[keyIndex + 2], buffer[keyIndex + 3] };

        int dataIndex = keyIndex + 4;
        int count = 0;
        for (int i = dataIndex; i < totalLength; i++)
        {
            buffer[i] = (byte)(buffer[i] ^ key[count % 4]);
            count++;
        }

        return Encoding.ASCII.GetString(buffer, dataIndex, dataLength);
    }

    //function to create  frames to send to client 
    /// <summary>
    /// Enum for opcode types
    /// </summary>
    public enum EOpcodeType
    {
        /* Denotes a continuation code */
        Fragment = 0,

        /* Denotes a text code */
        Text = 1,

        /* Denotes a binary code */
        Binary = 2,

        /* Denotes a closed connection */
        ClosedConnection = 8,

        /* Denotes a ping*/
        Ping = 9,

        /* Denotes a pong */
        Pong = 10
    }

    /// <summary>Gets an encoded websocket frame to send to a client from a string</summary>
    /// <param name="Message">The message to encode into the frame</param>
    /// <param name="Opcode">The opcode of the frame</param>
    /// <returns>Byte array in form of a websocket frame</returns>
    public static byte[] GetFrameFromString(string Message, EOpcodeType Opcode = EOpcodeType.Text)
    {
        byte[] response;
        byte[] bytesRaw = Encoding.Default.GetBytes(Message);
        byte[] frame = new byte[10];

        int indexStartRawData = -1;
        int length = bytesRaw.Length;

        frame[0] = (byte)(128 + (int)Opcode);
        if (length <= 125)
        {
            frame[1] = (byte)length;
            indexStartRawData = 2;
        }
        else if (length >= 126 && length <= 65535)
        {
            frame[1] = (byte)126;
            frame[2] = (byte)((length >> 8) & 255);
            frame[3] = (byte)(length & 255);
            indexStartRawData = 4;
        }
        else
        {
            frame[1] = (byte)127;
            frame[2] = (byte)((length >> 56) & 255);
            frame[3] = (byte)((length >> 48) & 255);
            frame[4] = (byte)((length >> 40) & 255);
            frame[5] = (byte)((length >> 32) & 255);
            frame[6] = (byte)((length >> 24) & 255);
            frame[7] = (byte)((length >> 16) & 255);
            frame[8] = (byte)((length >> 8) & 255);
            frame[9] = (byte)(length & 255);

            indexStartRawData = 10;
        }

        response = new byte[indexStartRawData + length];

        int i, reponseIdx = 0;

        //Add the frame bytes to the reponse
        for (i = 0; i < indexStartRawData; i++)
        {
            response[reponseIdx] = frame[i];
            reponseIdx++;
        }

        //Add the data bytes to the response
        for (i = 0; i < length; i++)
        {
            response[reponseIdx] = bytesRaw[i];
            reponseIdx++;
        }

        return response;
    }
}
}

Client html and javascript:

_x000D_
_x000D_
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"_x000D_
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">_x000D_
<html xmlns="http://www.w3.org/1999/xhtml">_x000D_
<head>_x000D_
    <script type="text/javascript">_x000D_
        var socket = new WebSocket('ws://localhost:8080/websession');_x000D_
        socket.onopen = function() {_x000D_
           // alert('handshake successfully established. May send data now...');_x000D_
     socket.send("Hi there from browser.");_x000D_
        };_x000D_
  socket.onmessage = function (evt) {_x000D_
                //alert("About to receive data");_x000D_
                var received_msg = evt.data;_x000D_
                alert("Message received = "+received_msg);_x000D_
            };_x000D_
        socket.onclose = function() {_x000D_
            alert('connection closed');_x000D_
        };_x000D_
    </script>_x000D_
</head>_x000D_
<body>_x000D_
</body>_x000D_
</html>
_x000D_
_x000D_
_x000D_

How to import CSV file data into a PostgreSQL table?

Use this SQL code

    copy table_name(atribute1,attribute2,attribute3...)
    from 'E:\test.csv' delimiter ',' csv header

the header keyword lets the DBMS know that the csv file have a header with attributes

for more visit http://www.postgresqltutorial.com/import-csv-file-into-posgresql-table/

Bootstrap 4 File Input

For Bootstrap v.5

document.querySelectorAll('.form-file-input')
        .forEach(el => el.addEventListener('change', e => e.target.parentElement.querySelector('.form-file-text').innerText = e.target.files[0].name));

Affect all file input element. No need to specify elements id.

Datatype for storing ip address in SQL Server

Thanks RBarry. I'm putting together an IP block allocation system and storing as binary is the only way to go.

I'm storing the CIDR representation (ex: 192.168.1.0/24) of the IP block in a varchar field, and using 2 calculated fields to hold the binary form of the start and end of the block. From there, I can run fast queries to see if a given block as already been allocated or is free to assign.

I modified your function to calculate the ending IP Address like so:

CREATE FUNCTION dbo.fnDisplayIPv4End(@block AS VARCHAR(18)) RETURNS BINARY(4)
AS
BEGIN
    DECLARE @bin AS BINARY(4)
    DECLARE @ip AS VARCHAR(15)
    DECLARE @size AS INT

    SELECT @ip = Left(@block, Len(@block)-3)
    SELECT @size = Right(@block, 2)

    SELECT @bin = CAST( CAST( PARSENAME( @ip, 4 ) AS INTEGER) AS BINARY(1))
                + CAST( CAST( PARSENAME( @ip, 3 ) AS INTEGER) AS BINARY(1))
                + CAST( CAST( PARSENAME( @ip, 2 ) AS INTEGER) AS BINARY(1))
                + CAST( CAST( PARSENAME( @ip, 1 ) AS INTEGER) AS BINARY(1))

    SELECT @bin = CAST(@bin + POWER(2, 32-@size) AS BINARY(4))
    RETURN @bin
END;
go

WCF on IIS8; *.svc handler mapping doesn't work

I had to enable HTTP Activation in .NET Framework 4.5 Advanced Services > WCF Services

Enable HTTP Activation

onclick or inline script isn't working in extension

Chrome Extensions don't allow you to have inline JavaScript (documentation).
The same goes for Firefox WebExtensions (documentation).

You are going to have to do something similar to this:

Assign an ID to the link (<a onClick=hellYeah("xxx")> becomes <a id="link">), and use addEventListener to bind the event. Put the following in your popup.js file:

document.addEventListener('DOMContentLoaded', function() {
    var link = document.getElementById('link');
    // onClick's logic below:
    link.addEventListener('click', function() {
        hellYeah('xxx');
    });
});

popup.js should be loaded as a separate script file:

<script src="popup.js"></script>

Invoke-customs are only supported starting with android 0 --min-api 26

After hours of struggling, I solved it by including the following within app/build.gradle:

android {
    compileOptions {
        sourceCompatibility JavaVersion.VERSION_1_8
        targetCompatibility JavaVersion.VERSION_1_8
    }
}

https://github.com/mapbox/mapbox-gl-native/issues/11378

Sheet.getRange(1,1,1,12) what does the numbers in bracket specify?

Found these docu on the google docu pages:

  • row --- int --- top row of the range
  • column --- int--- leftmost column of the range
  • optNumRows --- int --- number of rows in the range.
  • optNumColumns --- int --- number of columns in the range

In your example, you would get (if you picked the 3rd row) "C3:O3", cause C --> O is 12 columns

edit

Using the example on the docu:

// The code below will get the number of columns for the range C2:G8
// in the active spreadsheet, which happens to be "4"
var count = SpreadsheetApp.getActiveSheet().getRange(2, 3, 6, 4).getNumColumns(); Browser.msgBox(count);

The values between brackets:
2: the starting row = 2
3: the starting col = C
6: the number of rows = 6 so from 2 to 8
4: the number of cols = 4 so from C to G

So you come to the range: C2:G8

Oracle Insert via Select from multiple tables where one table may not have a row

It was not clear to me in the question if ts.tax_status_code is a primary or alternate key or not. Same thing with recipient_code. This would be useful to know.

You can deal with the possibility of your bind variable being null using an OR as follows. You would bind the same thing to the first two bind variables.

If you are concerned about performance, you would be better to check if the values you intend to bind are null or not and then issue different SQL statement to avoid the OR.

insert into account_type_standard 
(account_type_Standard_id, tax_status_id, recipient_id)
(
select 
   account_type_standard_seq.nextval,
   ts.tax_status_id, 
   r.recipient_id
from tax_status ts, recipient r
where (ts.tax_status_code = ? OR (ts.tax_status_code IS NULL and ? IS NULL))
and (r.recipient_code = ? OR (r.recipient_code IS NULL and ? IS NULL))

Install python 2.6 in CentOS

I unistalled the original version of python (2.6.6) and install 2.7(with option make && make altinstall) but when I tried install something with yum didn't work.

So I solved this issue as follow:

  1. # ln -s /usr/local/bin/python /usr/bin/python
  2. Download the RPM package python-2.6.6-36.el6.i686.rpm from http://rpm.pbone.net/index.php3/stat/4/idpl/20270470/dir/centos_6/com/python-2.6.6-36.el6.i686.rpm.html
  3. Execute as root rpm -Uvh python-2.6.6-36.el6.i686.rpm

Done

Dark color scheme for Eclipse

I've created my own dark color scheme (based on Oblivion from gedit), which I think is very nice to work with.

Preview & details at: http://www.rogerdudler.com/?p=362

We're happy to announce the beta of eclipsecolorthemes.org, a new website to download, create and maintain Eclipse color themes / schemes. The theme editor allows you to copy an existing theme and edit the colors with a live preview of your changes on specific editors. The downloadable themes support a lot of editors (PHP, Java, SQL, Ant, text, HTML, CSS, and more to follow)

There's a growing list of themes already available on the site:

Screenshot of eclipsecolorthemes.org

You can read more about the launch here.

The process cannot access the file because it is being used by another process (File is created but contains nothing)

You are writing to the file prior to closing your filestream:

using(FileStream fs=new FileStream(path,FileMode.OpenOrCreate))
using (StreamWriter str=new StreamWriter(fs))
{
   str.BaseStream.Seek(0,SeekOrigin.End); 
   str.Write("mytext.txt.........................");
   str.WriteLine(DateTime.Now.ToLongTimeString()+" "+DateTime.Now.ToLongDateString());
   string addtext="this line is added"+Environment.NewLine;

   str.Flush();

}

File.AppendAllText(path,addtext);  //Exception occurrs ??????????
string readtext=File.ReadAllText(path);
Console.WriteLine(readtext);

The above code should work, using the methods you are currently using. You should also look into the using statement and wrap your streams in a using block.

Oracle: SQL query that returns rows with only numeric values

What about 1.1E10, +1, -0, etc? Parsing all possible numbers is trickier than many people think. If you want to include as many numbers are possible you should use the to_number function in a PL/SQL function. From http://www.oracle-developer.net/content/utilities/is_number.sql:

CREATE OR REPLACE FUNCTION is_number (str_in IN VARCHAR2) RETURN NUMBER IS
   n NUMBER;
BEGIN
   n := TO_NUMBER(str_in);
   RETURN 1;
EXCEPTION
   WHEN VALUE_ERROR THEN
      RETURN 0;
END;
/

How do I get the current username in .NET using C#?

If you are in a network of users, then the username will be different:

Environment.UserName
- Will Display format : 'Username'

rather than

System.Security.Principal.WindowsIdentity.GetCurrent().Name
- Will Display format : 'NetworkName\Username'

Choose the format you want.

how to get program files x86 env variable?

IMHO, one point that is missing in this discussion is that whatever variable you use, it is guaranteed to always point at the appropriate folder. This becomes critical in the rare cases where Windows is installed on a drive other than C:\

Edit a commit message in SourceTree Windows (already pushed to remote)

If the comment message includes non-English characters, using method provided by user456814, those characters will be replaced by question marks. (tested under sourcetree Ver2.5.5.0)

So I have to use the following method.

CAUTION: if the commit has been pulled by other members, changes below might cause chaos for them.

Step1: In the sourcetree main window, locate your repo tab, and click the "terminal" button to open the git command console.

Step2:

[Situation A]: target commit is the latest one.

1) In the git command console, input

git commit --amend -m "new comment message"

2) If the target commit has been pushed to remote, you have to push again by force. In the git command console, input

git push --force

[Situation B]: target commit is not the latest one.

1) In the git command console, input

git rebase -i HEAD~n

It is to squash the latest n commits. e.g. if you want to edit the message before the last one, n is 2. This command will open a vi window, the first word of each line is "pick", and you change the "pick" to "reword" for the line you want to edit. Then, input :wq to save&quit that vi window. Now, a new vi window will be open, in this window you input your new message. Also use :wq to save&quit.

2) If the target commit has been pushed to remote, you have to push again by force. In the git command console, input

git push --force


Finally: In the sourcetree main window, Press F5 to refresh.

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

$(function() {

      $("#upload").bind("click", function() {
            var regex = /^([a-zA-Z0-9\s_\\.\-:])+(.csv|.xlsx)$/;
            if (regex.test($("#fileUpload").val().toLowerCase())) {
              if (typeof(FileReader) != "undefined") {
                var reader = new FileReader();
                reader.onload = function(e) {
                    var customers = new Array();
                    var rows = e.target.result.split("\r\n");
                    for (var i = 0; i < rows.length - 1; i++) {
                      var cells = rows[i].split(",");
                      if (cells[0] == "" || cells[0] == undefined) {
                        var s = customers[customers.length - 1];
                        s.Ord.push(cells[2]);
                      } else {
                        var dt = customers.find(x => x.Number === cells[0]);
                        if (dt == undefined) {
                          if (cells.length > 1) {
                            var customer = {};
                            customer.Number = cells[0];
                            customer.Name = cells[1];
                            customer.Ord = new Array();

                            customer.Ord.push(cells[2]);
                            customer.Point_ID = cells[3];
                            customer.Point_Name = cells[4];
                            customer.Point_Type = cells[5];
                            customer.Set_ORD = cells[6];
                            customers.push(customer);
                          }
                        } else {
                          var dtt = dt;
                          dtt.Ord.push(cells[2]);

                        }
                      }
                    }

How to check if a std::thread is still running?

Surely have a mutex-wrapped variable initialised to false, that the thread sets to true as the last thing it does before exiting. Is that atomic enough for your needs?

Count items in a folder with PowerShell

You can also use an alias

(ls).Count

How to get phpmyadmin username and password

If you don't remember your password, then run this command in the Shell:

mysqladmin.exe -u root password NewPassword

where 'NewPassword' is your new password.

Redirect to specified URL on PHP script completion?

<?php

// do something here

header("Location: http://example.com/thankyou.php");
?>

How can I convert string date to NSDate?

 func convertDateFormatter(date: String) -> String
 {

    let dateFormatter = NSDateFormatter()
    dateFormatter.dateFormat = "yyyy-MM-dd'T'HH:mm:ss.SSSZ"//this your string date format
    dateFormatter.timeZone = NSTimeZone(name: "UTC")
    let date = dateFormatter.dateFromString(date)


    dateFormatter.dateFormat = "yyyy MMM EEEE HH:mm"///this is what you want to convert format
    dateFormatter.timeZone = NSTimeZone(name: "UTC")
    let timeStamp = dateFormatter.stringFromDate(date!)


    return timeStamp
}

Updated for Swift 3.

func convertDateFormatter(date: String) -> String
{

    let dateFormatter = DateFormatter()
    dateFormatter.dateFormat = "yyyy-MM-dd'T'HH:mm:ss.SSSZ"//this your string date format
    dateFormatter.timeZone = NSTimeZone(name: "UTC") as TimeZone!
    let date = dateFormatter.date(from: date)


    dateFormatter.dateFormat = "yyyy MMM EEEE HH:mm"///this is what you want to convert format
    dateFormatter.timeZone = NSTimeZone(name: "UTC") as TimeZone!
    let timeStamp = dateFormatter.string(from: date!)


    return timeStamp
}

Execute command without keeping it in history

This is handy if you want to erase all the history, including the fact that you erased all the history!

rm .bash_history;export HISTFILE=/dev/null;exit

How to undo a SQL Server UPDATE query?

If you can catch this in time and you don't have the ability to ROLLBACK or use the transaction log, you can take a backup immediately and use a tool like Redgate's SQL Data Compare to generate a script to "restore" the affected data. This worked like a charm for me. :)

HowTo Generate List of SQL Server Jobs and their owners

If you don't have access to sysjobs table (someone elses server etc) you might be have or be allowed access to sysjobs_view

SELECT *
 from  msdb..sysjobs_view s 
 left join master.sys.syslogins l on s.owner_sid = l.sid

or

SELECT *, SUSER_SNAME(s.owner_sid) AS owner
 from  msdb..sysjobs_view s 

How can I use getSystemService in a non-activity class (LocationManager)?

For some non-activity classes, like Worker, you're already given a Context object in the public constructor.

Worker(Context context, WorkerParameters workerParams)

You can just use that, e.g., save it to a private Context variable in the class (say, mContext), and then, for example

mContext.getSystenService(Context.ACTIVITY_SERVICE)

How to generate components in a specific folder with Angular CLI?

The above options were not working for me because unlike creating a directory or file in the terminal, when the CLI generates a component, it adds the path src/app by default to the path you enter.

If I generate the component from my main app folder like so (WRONG WAY)

ng g c ./src/app/child/grandchild 

the component that was generated was this:

src/app/src/app/child/grandchild.component.ts

so I only had to type

ng g c child/grandchild 

Hopefully this helps someone

Add all files to a commit except a single file?

You can try this: git add * && git reset main/dontcheckmein.txt

EXCEL VBA Check if entry is empty or not 'space'

Here is the code to check whether value is present or not.

If Trim(textbox1.text) <> "" Then
     'Your code goes here
Else
     'Nothing
End If

I think this will help.

Array functions in jQuery

jQuery has very limited array functions since JavaScript has most of them itself. But here are the ones they have: Utilities - jQuery API.

Gerrit error when Change-Id in commit messages are missing

Try this:

git commit --amend

Then copy and paste the Change-Id: I55862204ef71f69bc88c79fe2259f7cb8365699a at the end of the file.

Save it and push it again!

Delete all rows in table

Truncate table is faster than delete * from XXX. Delete is slow because it works one row at a time. There are a few situations where truncate doesn't work, which you can read about on MSDN.

How can I resize an image using Java?

If, having imagemagick installed on your maschine is an option, I recommend im4java. It is a very thin abstraction layer upon the command line interface, but does its job very well.

What are the file limits in Git (number and size)?

There is no real limit -- everything is named with a 160-bit name. The size of the file must be representable in a 64 bit number so no real limit there either.

There is a practical limit, though. I have a repository that's ~8GB with >880,000 files and git gc takes a while. The working tree is rather large so operations that inspect the entire working directory take quite a while. This repo is only used for data storage, though, so it's just a bunch of automated tools that handle it. Pulling changes from the repo is much, much faster than rsyncing the same data.

%find . -type f | wc -l
791887
%time git add .
git add .  6.48s user 13.53s system 55% cpu 36.121 total
%time git status
# On branch master
nothing to commit (working directory clean)
git status  0.00s user 0.01s system 0% cpu 47.169 total
%du -sh .
29G     .
%cd .git
%du -sh .
7.9G    .

Why does python use 'else' after for and while loops?

I agree, it's more like an 'elif not [condition(s) raising break]'.

I know this is an old thread, but I am looking into the same question right now, and I'm not sure anyone has captured the answer to this question in the way I understand it.

For me, there are three ways of "reading" the else in For... else or While... else statements, all of which are equivalent, are:

  1. else == if the loop completes normally (without a break or error)
  2. else == if the loop does not encounter a break
  3. else == else not (condition raising break) (presumably there is such a condition, or you wouldn't have a loop)

So, essentially, the "else" in a loop is really an "elif ..." where '...' is (1) no break, which is equivalent to (2) NOT [condition(s) raising break].

I think the key is that the else is pointless without the 'break', so a for...else includes:

for:
    do stuff
    conditional break # implied by else
else not break:
    do more stuff

So, essential elements of a for...else loop are as follows, and you would read them in plainer English as:

for:
    do stuff
    condition:
        break
else: # read as "else not break" or "else not condition"
    do more stuff

As the other posters have said, a break is generally raised when you are able to locate what your loop is looking for, so the else: becomes "what to do if target item not located".

Example

You can also use exception handling, breaks, and for loops all together.

for x in range(0,3):
    print("x: {}".format(x))
    if x == 2:
        try:
            raise AssertionError("ASSERTION ERROR: x is {}".format(x))
        except:
            print(AssertionError("ASSERTION ERROR: x is {}".format(x)))
            break
else:
    print("X loop complete without error")

Result

x: 0
x: 1
x: 2
ASSERTION ERROR: x is 2
----------
# loop not completed (hit break), so else didn't run

Example

Simple example with a break being hit.

for y in range(0,3):
    print("y: {}".format(y))
    if y == 2: # will be executed
        print("BREAK: y is {}\n----------".format(y))
        break
else: # not executed because break is hit
    print("y_loop completed without break----------\n")

Result

y: 0
y: 1
y: 2
BREAK: y is 2
----------
# loop not completed (hit break), so else didn't run

Example

Simple example where there no break, no condition raising a break, and no error are encountered.

for z in range(0,3):
     print("z: {}".format(z))
     if z == 4: # will not be executed
         print("BREAK: z is {}\n".format(y))
         break
     if z == 4: # will not be executed
         raise AssertionError("ASSERTION ERROR: x is {}".format(x))
else:
     print("z_loop complete without break or error\n----------\n")

Result

z: 0
z: 1
z: 2
z_loop complete without break or error
----------

What is the best Java email address validation method?

Late to the question, here, but: I maintain a class at this address: http://lacinato.com/cm/software/emailrelated/emailaddress

It is based on Les Hazlewood's class, but has numerous improvements and fixes a few bugs. Apache license.

I believe it is the most capable email parser in Java, and I have yet to see one more capable in any language, though there may be one out there. It's not a lexer-style parser, but uses some complicated java regex, and thus is not as efficient as it could be, but my company has parsed well over 10 billion real-world addresses with it: it's certainly usable in a high-performance situation. Maybe once a year it'll hit an address that causes a regex stack overflow (appropriately), but these are spam addresses which are hundreds or thousands of characters long with many many quotes and parenthesis and the like.

RFC 2822 and the related specs are really quite permissive in terms of email addresses, so a class like this is overkill for most uses. For example, the following is a legitimate address, according to spec, spaces and all:

"<bob \" (here) " < (hi there) "bob(the man)smith" (hi) @ (there) example.com (hello) > (again)

No mail server would allow that, but this class can parse it (and rewrite it to a usable form).

We found the existing Java email parser options to be insufficiently durable (meaning, all of them could not parse some valid addresses), so we created this class.

The code is well-documented and has a lot of easy-to-change options to allow or disallow certain email forms. It also provides a lot of methods to access certain parts of the address (left-hand side, right-hand side, personal names, comments, etc), to parse/validate mailbox-list headers, to parse/validate the return-path (which is unique among the headers), and so forth.

The code as written has a javamail dependency, but it's easy to remove if you don't want the minor functionality it provides.

Check that an email address is valid on iOS

to validate the email string you will need to write a regular expression to check it is in the correct form. there are plenty out on the web but be carefull as some can exclude what are actually legal addresses.

essentially it will look something like this

^((?>[a-zA-Z\d!#$%&'*+\-/=?^_`{|}~]+\x20*|"((?=[\x01-\x7f])[^"\\]|\\[\x01-\x7f])*"\x20*)*(?<angle><))?((?!\.)(?>\.?[a-zA-Z\d!#$%&'*+\-/=?^_`{|}~]+)+|"((?=[\x01-\x7f])[^"\\]|\\[\x01-\x7f])*")@(((?!-)[a-zA-Z\d\-]+(?<!-)\.)+[a-zA-Z]{2,}|\[(((?(?<!\[)\.)(25[0-5]|2[0-4]\d|[01]?\d?\d)){4}|[a-zA-Z\d\-]*[a-zA-Z\d]:((?=[\x01-\x7f])[^\\\[\]]|\\[\x01-\x7f])+)\])(?(angle)>)$

Actually checking if the email exists and doesn't bounce would mean sending an email and seeing what the result was. i.e. it bounced or it didn't. However it might not bounce for several hours or not at all and still not be a "real" email address. There are a number of services out there which purport to do this for you and would probably be paid for by you and quite frankly why bother to see if it is real?

It is good to check the user has not misspelt their email else they could enter it incorrectly, not realise it and then get hacked of with you for not replying. However if someone wants to add a bum email address there would be nothing to stop them creating it on hotmail or yahoo (or many other places) to gain the same end.

So do the regular expression and validate the structure but forget about validating against a service.

BASH Syntax error near unexpected token 'done'

I had same problem, but solved.

I removed the following line in .bashrc

alias do="docker.exe" # this line caused the problem

I use WSL(windows subsystem for linux)

How can I make an image transparent on Android?

On newer versions of Android (post Android 4.2 (Jelly Bean) at least), the setAlpha(int value) method is depreciated. Instead, use the setAlpha(float value) method that takes a float between 0 and 1 where 0 is complete transparency and 1 is no transparency.

Reading Email using Pop3 in C#

I just tried SMTPop and it worked.

  1. I downloaded this.
  2. Added smtpop.dll reference to my C# .NET project

Wrote the following code:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;    
using SmtPop;

namespace SMT_POP3 {

    class Program {
        static void Main(string[] args) {
            SmtPop.POP3Client pop = new SmtPop.POP3Client();
            pop.Open("<hostURL>", 110, "<username>", "<password>");

            // Get message list from POP server
            SmtPop.POPMessageId[] messages = pop.GetMailList();
            if (messages != null) {

                // Walk attachment list
                foreach(SmtPop.POPMessageId id in messages) {
                    SmtPop.POPReader reader= pop.GetMailReader(id);
                    SmtPop.MimeMessage msg = new SmtPop.MimeMessage();

                    // Read message
                    msg.Read(reader);
                    if (msg.AddressFrom != null) {
                        String from= msg.AddressFrom[0].Name;
                        Console.WriteLine("from: " + from);
                    }
                    if (msg.Subject != null) {
                        String subject = msg.Subject;
                        Console.WriteLine("subject: "+ subject);
                    }
                    if (msg.Body != null) {
                        String body = msg.Body;
                        Console.WriteLine("body: " + body);
                    }
                    if (msg.Attachments != null && false) {
                        // Do something with first attachment
                        SmtPop.MimeAttachment attach = msg.Attachments[0];

                        if (attach.Filename == "data") {
                           // Read data from attachment
                           Byte[] b = Convert.FromBase64String(attach.Body);
                           System.IO.MemoryStream mem = new System.IO.MemoryStream(b, false);

                           //BinaryFormatter f = new BinaryFormatter();
                           // DataClass data= (DataClass)f.Deserialize(mem); 
                           mem.Close();
                        }                     

                        // Delete message
                        // pop.Dele(id.Id);
                    }
               }
           }    
           pop.Quit();
        }
    }
}

Automatic creation date for Django model form objects?

Well, the above answer is correct, auto_now_add and auto_now would do it, but it would be better to make an abstract class and use it in any model where you require created_at and updated_at fields.

class TimeStampMixin(models.Model):
    created_at = models.DateTimeField(auto_now_add=True)
    updated_at = models.DateTimeField(auto_now=True)

    class Meta:
        abstract = True

Now anywhere you want to use it you can do a simple inherit and you can use timestamp in any model you make like.

class Posts(TimeStampMixin):
    name = models.CharField(max_length=50)
    ...
    ...

In this way, you can leverage object-oriented reusability, in Django DRY(don't repeat yourself)

static constructors in C++? I need to initialize private static objects

The concept of static constructors was introduced in Java after they learned from the problems in C++. So we have no direct equivalent.

The best solution is to use POD types that can be initialised explicitly.
Or make your static members a specific type that has its own constructor that will initialize it correctly.

//header

class A
{
    // Make sure this is private so that nobody can missues the fact that
    // you are overriding std::vector. Just doing it here as a quicky example
    // don't take it as a recomendation for deriving from vector.
    class MyInitedVar: public std::vector<char>
    {
        public:
        MyInitedVar()
        {
           // Pre-Initialize the vector.
           for(char c = 'a';c <= 'z';++c)
           {
               push_back(c);
           }
        }
    };
    static int          count;
    static MyInitedVar  var1;

};


//source
int            A::count = 0;
A::MyInitedVar A::var1;

Is it not possible to stringify an Error using JSON.stringify?

We needed to serialise an arbitrary object hierarchy, where the root or any of the nested properties in the hierarchy could be instances of Error.

Our solution was to use the replacer param of JSON.stringify(), e.g.:

_x000D_
_x000D_
function jsonFriendlyErrorReplacer(key, value) {_x000D_
  if (value instanceof Error) {_x000D_
    return {_x000D_
      // Pull all enumerable properties, supporting properties on custom Errors_x000D_
      ...value,_x000D_
      // Explicitly pull Error's non-enumerable properties_x000D_
      name: value.name,_x000D_
      message: value.message,_x000D_
      stack: value.stack,_x000D_
    }_x000D_
  }_x000D_
_x000D_
  return value_x000D_
}_x000D_
_x000D_
let obj = {_x000D_
    error: new Error('nested error message')_x000D_
}_x000D_
_x000D_
console.log('Result WITHOUT custom replacer:', JSON.stringify(obj))_x000D_
console.log('Result WITH custom replacer:', JSON.stringify(obj, jsonFriendlyErrorReplacer))
_x000D_
_x000D_
_x000D_

The value violated the integrity constraints for the column

You can replace the values "null" from the original file & field/column.

File Explorer in Android Studio

Refer Here

With Android Studio, you may use Android file explorer like: Click View > Tool Windows > Device File Explorer or click the Device File Explorer

Having links relative to root?

To give a URL to an image tag which locates images/ directory in the root like

`logo.png`

you should give src URL starting with / as follows:

<img src="/images/logo.png"/>

This code works in any directories without any troubles even if you are in branches/europe/about.php still the logo can be seen right there.

Getting full-size profile picture

Profile pictures are scaled down to 125x125 on the facebook sever when they're uploaded, so as far as I know you can't get pictures bigger than that. How big is the picture you're getting?

SQL Update Multiple Fields FROM via a SELECT Statement

I just had to solve a similar problem where I added a Sequence number (so that items as grouped by a parent ID, have a Sequence that I can order by (and presumably the user can change the sequence number to change the ordering).

In my case, it's insurance for a Patient, and the user gets to set the order they are assigned, so just going by the primary key isn't useful for long-term, but is useful for setting a default.

The problem with all the other solutions is that certain aggregate functions aren't allowed outside of a SELECT

This SELECT gets you the new Sequence number:

select PatientID,
       PatientInsuranceID, 
       Sequence, 
       Row_Number() over(partition by PatientID order by PatientInsuranceID) as RowNum
from PatientInsurance
order by PatientID, PatientInsuranceID

This update command, would be simple, but isn't allowed:

update PatientInsurance
set Sequence = Row_Number() over(partition by PatientID order by PatientInsuranceID)

The solution that worked (I just did it), and is similar to eKek0's solution:

UPDATE PatientInsurance
SET  PatientInsurance.Sequence = q.RowNum
FROM (select PatientInsuranceID, 
             Row_Number() over(partition by PatientID order by PatientInsuranceID) as RowNum
      from PatientInsurance
     ) as q 
WHERE PatientInsurance.PatientInsuranceID=q.PatientInsuranceID 

this lets me select the ID I need to match things up to, and the value I need to set for that ID. Other solutions would have been fine IF I wasn't using Row_Number() which won't work outside of a SELECT.

Given that this is a 1 time operation, it's coding is still simple, and run-speed is fast enough for 4000+ rows

How to execute a query in ms-access in VBA code?

How about something like this...

Dim rs As RecordSet
Set rs = Currentdb.OpenRecordSet("SELECT PictureLocation, ID FROM MyAccessTable;")

Do While Not rs.EOF
   Debug.Print rs("PictureLocation") & " - " & rs("ID")
   rs.MoveNext
Loop

How to check if a string contains only digits in Java

According to Oracle's Java Documentation:

private static final Pattern NUMBER_PATTERN = Pattern.compile(
        "[\\x00-\\x20]*[+-]?(NaN|Infinity|((((\\p{Digit}+)(\\.)?((\\p{Digit}+)?)" +
        "([eE][+-]?(\\p{Digit}+))?)|(\\.((\\p{Digit}+))([eE][+-]?(\\p{Digit}+))?)|" +
        "(((0[xX](\\p{XDigit}+)(\\.)?)|(0[xX](\\p{XDigit}+)?(\\.)(\\p{XDigit}+)))" +
        "[pP][+-]?(\\p{Digit}+)))[fFdD]?))[\\x00-\\x20]*");
boolean isNumber(String s){
return NUMBER_PATTERN.matcher(s).matches()
}

Mockito - difference between doReturn() and when()

The two syntaxes for stubbing are roughly equivalent. However, you can always use doReturn/when for stubbing; but there are cases where you can't use when/thenReturn. Stubbing void methods is one such. Others include use with Mockito spies, and stubbing the same method more than once.

One thing that when/thenReturn gives you, that doReturn/when doesn't, is type-checking of the value that you're returning, at compile time. However, I believe this is of almost no value - if you've got the type wrong, you'll find out as soon as you run your test.

I strongly recommend only using doReturn/when. There is no point in learning two syntaxes when one will do.

You may wish to refer to my answer at Forming Mockito "grammars" - a more detailed answer to a very closely related question.

SOAP-UI - How to pass xml inside parameter

NOTE: This one is just an alternative for the previous provided .NET framework 3.5 and above

You can send it as raw xml

<test>or like this</test>

If you declare the paramater2 as XElement data type

Error: "an object reference is required for the non-static field, method or property..."

Simply add static in the declaration of these two methods and the compile time error will disappear!

By default in C# methods are instance methods, and they receive the implicit "self" argument. By making them static, no such argument is needed (nor available), and the method must then of course refrain from accessing any instance (non-static) objects or methods of the class.

More info on static methods
Provided the class and the method's access modifiers (public vs. private) are ok, a static method can then be called from anywhere without having to previously instantiate a instance of the class. In other words static methods are used with the following syntax:

    className.classMethod(arguments)
rather than
    someInstanceVariable.classMethod(arguments)

A classical example of static methods are found in the System.Math class, whereby we can call a bunch of these methods like

   Math.Sqrt(2)
   Math.Cos(Math.PI)

without ever instantiating a "Math" class (in fact I don't even know if such an instance is possible)

How to check if element in groovy array/hash/collection/list?

def fruitBag = ["orange","banana","coconut"]
def fruit = fruitBag.collect{item -> item.contains('n')}

I did it like this so it works if someone is looking for it.

Apache shows PHP code instead of executing it

You must enable php! Check the folder mods-enabled in the Apache directory (default: /etc/apache2/) to see if you find a file named php. I don't remember the extension but I think it's .so.

Also check in /var/log/apache2/error.log to see if you have any other errors.

loop through json array jquery

You have to parse the string as JSON (data[0] == "[" is an indication that data is actually a string, not an object):

data = $.parseJSON(data);
$.each(data, function(i, item) {
    alert(item);
});

Allow Access-Control-Allow-Origin header using HTML5 fetch API

I know this is an older post, but I found what worked for me to fix this error was using the IP address of my server instead of using the domain name within my fetch request. So for example:

#(original) var request = new Request('https://davidwalsh.name/demo/arsenal.json');
#use IP instead
var request = new Request('https://0.0.0.0/demo/arsenal.json');

fetch(request).then(function(response) {
    // Convert to JSON
    return response.json();
}).then(function(j) {
    // Yay, `j` is a JavaScript object
    console.log(JSON.stringify(j));
}).catch(function(error) {
    console.log('Request failed', error)
});

Eclipse: How to build an executable jar with external jar?

As a good practice you can use an Ant Script (Eclipse comes with it) to generate your JAR file. Inside this JAR you can have all dependent libs.

You can even set the MANIFEST's Class-path header to point to files in your filesystem, it's not a good practice though.

Ant build.xml script example:

<project name="jar with libs" default="compile and build" basedir=".">
<!-- this is used at compile time -->
<path id="example-classpath">
    <pathelement location="${root-dir}" />
    <fileset dir="D:/LIC/xalan-j_2_7_1" includes="*.jar" />
</path>

<target name="compile and build">
    <!-- deletes previously created jar -->
    <delete file="test.jar" />

    <!-- compile your code and drop .class into "bin" directory -->
    <javac srcdir="${basedir}" destdir="bin" debug="true" deprecation="on">
        <!-- this is telling the compiler where are the dependencies -->
        <classpath refid="example-classpath" />
    </javac>

    <!-- copy the JARs that you need to "bin" directory  -->
    <copy todir="bin">
        <fileset dir="D:/LIC/xalan-j_2_7_1" includes="*.jar" />
    </copy>

    <!-- creates your jar with the contents inside "bin" (now with your .class and .jar dependencies) -->
    <jar destfile="test.jar" basedir="bin" duplicate="preserve">
        <manifest>
            <!-- Who is building this jar? -->
            <attribute name="Built-By" value="${user.name}" />
            <!-- Information about the program itself -->
            <attribute name="Implementation-Vendor" value="ACME inc." />
            <attribute name="Implementation-Title" value="GreatProduct" />
            <attribute name="Implementation-Version" value="1.0.0beta2" />
            <!-- this tells which class should run when executing your jar -->
            <attribute name="Main-class" value="ApplyXPath" />
        </manifest>
    </jar>
</target>

Simple 'if' or logic statement in Python

Here's a Boolean thing:

if (not suffix == "flac" )  or (not suffix == "cue" ):   # WRONG! FAILS
    print  filename + ' is not a flac or cue file'

but

if not (suffix == "flac"  or suffix == "cue" ):     # CORRECT!
       print  filename + ' is not a flac or cue file'

(not a) or (not b) == not ( a and b ) , is false only if a and b are both true

not (a or b) is true only if a and be are both false.

Adjust table column width to content size

maybe problem with margin?

width:auto;
padding: 0px;
margin: 0px

Sorting an ArrayList of objects using a custom sorting order

I did it by the following way. number and name are two arraylist. I have to sort name .If any change happen to name arralist order then the number arraylist also change its order.

public void sortval(){

        String tempname="",tempnum="";

         if (name.size()>1) // check if the number of orders is larger than 1
            {
                for (int x=0; x<name.size(); x++) // bubble sort outer loop
                {
                    for (int i=0; i < name.size()-x-1; i++) {
                        if (name.get(i).compareTo(name.get(i+1)) > 0)
                        {

                            tempname = name.get(i);

                            tempnum=number.get(i);


                           name.set(i,name.get(i+1) );
                           name.set(i+1, tempname);

                            number.set(i,number.get(i+1) );
                            number.set(i+1, tempnum);


                        }
                    }
                }
            }



}

React-router urls don't work when refreshing or writing manually

In case you are running it on a Google Bucket, the simple solution to this is to consider 'index.html' for Error (404 not found) Page.

To do so:

  1. In the list of buckets, find the bucket you created.
  2. Click the Bucket overflow menu (...) associated with the bucket and select Edit website configuration.
  3. In the website configuration dialog, specify the main page as the error page too.

How do I delete virtual interface in Linux?

Have you tried:

ifconfig 10:35978f0 down

As the physical interface is 10 and the virtual aspect is after the colon :.

See also https://www.cyberciti.biz/faq/linux-command-to-remove-virtual-interfaces-or-network-aliases/

An error occurred while executing the command definition. See the inner exception for details

Look at the Inner Exception and find out what object might have caused the problem, you might have changed its name.

For-loop vs while loop in R

Because 1 is numeric, but not integer (i.e. it's a floating point number), and 1:6000 is numeric and integer.

> print(class(1))
[1] "numeric"
> print(class(1:60000))
[1] "integer"

60000 squared is 3.6 billion, which is NOT representable in signed 32-bit integer, hence you get an overflow error:

> as.integer(60000)*as.integer(60000)
[1] NA
Warning message:
In as.integer(60000) * as.integer(60000) : NAs produced by integer overflow

3.6 billion is easily representable in floating point, however:

> as.single(60000)*as.single(60000)
[1] 3.6e+09

To fix your for code, convert to a floating point representation:

function (N)
{
    for(i in as.single(1:N)) {
        y <- i*i
    }
}

Determine the number of rows in a range

That single last line worked perfectly @GSerg.

The other function was what I had been working on but I don't like having to resort to UDF's unless absolutely necessary.

I had been trying a combination of excel and vba and had got this to work - but its clunky compared with your answer.

strArea = Sheets("Oper St Report CC").Range("cc_rev").CurrentRegion.Address
cc_rev_rows = "=ROWS(" & strArea & ")"
Range("cc_rev_count").Formula = cc_rev_rows

How to load an external webpage into a div of a html page

Using simple html,

 <div> 
    <object type="text/html" data="http://validator.w3.org/" width="800px" height="600px" style="overflow:auto;border:5px ridge blue">
    </object>
 </div>

Or jquery,

<script>
        $("#mydiv")
            .html('<object data="http://your-website-domain"/>');
</script>

JSFIDDLE DEMO

How to create custom exceptions in Java?

public class MyException extends Exception {
        // special exception code goes here
}

Throw it as:

 throw new MyException ("Something happened")

Catch as:

catch (MyException e)
{
   // something
}

How to loop through a HashMap in JSP?

Just the same way as you would do in normal Java code.

for (Map.Entry<String, String> entry : countries.entrySet()) {
    String key = entry.getKey();
    String value = entry.getValue();
    // ...
}

However, scriptlets (raw Java code in JSP files, those <% %> things) are considered a poor practice. I recommend to install JSTL (just drop the JAR file in /WEB-INF/lib and declare the needed taglibs in top of JSP). It has a <c:forEach> tag which can iterate over among others Maps. Every iteration will give you a Map.Entry back which in turn has getKey() and getValue() methods.

Here's a basic example:

<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>

<c:forEach items="${map}" var="entry">
    Key = ${entry.key}, value = ${entry.value}<br>
</c:forEach>

Thus your particular issue can be solved as follows:

<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>

<select name="country">
    <c:forEach items="${countries}" var="country">
        <option value="${country.key}">${country.value}</option>
    </c:forEach>
</select>

You need a Servlet or a ServletContextListener to place the ${countries} in the desired scope. If this list is supposed to be request-based, then use the Servlet's doGet():

protected void doGet(HttpServletRequest request, HttpServletResponse response) {
    Map<String, String> countries = MainUtils.getCountries();
    request.setAttribute("countries", countries);
    request.getRequestDispatcher("/WEB-INF/page.jsp").forward(request, response);
}

Or if this list is supposed to be an application-wide constant, then use ServletContextListener's contextInitialized() so that it will be loaded only once and kept in memory:

public void contextInitialized(ServletContextEvent event) {
    Map<String, String> countries = MainUtils.getCountries();
    event.getServletContext().setAttribute("countries", countries);
}

In both cases the countries will be available in EL by ${countries}.

Hope this helps.

See also:

Using multiple arguments for string formatting in Python (e.g., '%s ... %s')

For python2 you can also do this

'%(author)s in %(publication)s'%{'author':unicode(self.author),
                                  'publication':unicode(self.publication)}

which is handy if you have a lot of arguments to substitute (particularly if you are doing internationalisation)

Python2.6 onwards supports .format()

'{author} in {publication}'.format(author=self.author,
                                   publication=self.publication)

Compare a string using sh shell

Of the 4 shells that I've tested, ABC -eq XYZ evaluates to true in the test builtin for zsh and ksh. The expression evaluates to false under /usr/bin/test and the builtins for dash and bash. In ksh and zsh, the strings are converted to numerical values and are equal since they are both 0. IMO, the behavior of the builtins for ksh and zsh is incorrect, but the spec for test is ambiguous on this.

PHP MySQL Query Where x = $variable

You have to do this to echo it:

echo $row['note'];

(The data is coming as an array)

JavaScript style.display="none" or jQuery .hide() is more efficient?

Efficiency isn't going to matter for something like this in 99.999999% of situations. Do whatever is easier to read and or maintain.

In my apps I usually rely on classes to provide hiding and showing, for example .addClass('isHidden')/.removeClass('isHidden') which would allow me to animate things with CSS3 if I wanted to. It provides more flexibility.

How to limit the number of dropzone.js files uploaded?

You can limit the number of files uploaded by changing in dropezone.js

Dropzone.prototype.defaultOptions = { maxFiles: 10, }

Is it possible to Turn page programmatically in UIPageViewController?

I also needed a button to navigate left on a PageViewController, one that should do exactly what you would expect from the swipe motion.

Since I had a few rules already in place inside "pageViewController:viewControllerBeforeViewController" for dealing with the natural swipe navigation, I wanted the button to re-use all that code, and simply could not afford to use specific indexes to reach pages as the previous answers did. So, I had to take an alternate solution.

Please note that the following code is for a Page View Controller that is a property inside my custom ViewController, and has its spine set to mid.

Here is the code I wrote for my Navigate Left button:

- (IBAction)btnNavigateLeft_Click:(id)sender {

    // Calling the PageViewController to obtain the current left page
    UIViewController *currentLeftPage = [_pageController.viewControllers objectAtIndex:0];

    // Creating future pages to be displayed
    NSArray *newDisplayedPages = nil;
    UIViewController *newRightPage = nil;
    UIViewController *newLeftPage = nil;

    // Calling the delegate to obtain previous pages
    // My "pageViewController:viewControllerBeforeViewController" method returns nil if there is no such page (first page of the book).
    newRightPage = [self pageViewController:_pageController viewControllerBeforeViewController:currentLeftPage];
    if (newRightPage) {
        newLeftPage = [self pageViewController:_pageController viewControllerBeforeViewController:newRightPage];
    }

    if (newLeftPage) {
        newDisplayedPages = [[NSArray alloc] initWithObjects:newLeftPage, newRightPage, nil];
    }

    // If there are two new pages to display, show them with animation.
    if (newDisplayedPages) {
        [_pageController setViewControllers:newDisplayedPages direction:UIPageViewControllerNavigationDirectionReverse animated:YES completion:nil];
    }
}

You can do something very similar to make a right navigation button from here.

Class extending more than one class Java?

In Java multiple inheritance is not permitted. It was excluded from the language as a design decision, primarily to avoid circular dependencies.

Scenario1: As you have learned the following is not possible in Java:

public class Dog extends Animal, Canine{

}

Scenario 2: However the following is possible:

public class Canine extends Animal{

}

public class Dog extends Canine{

}

The difference in these two approaches is that in the second approach there is a clearly defined parent or super class, while in the first approach the super class is ambiguous.

Consider if both Animal and Canine had a method drink(). Under the first scenario which parent method would be called if we called Dog.drink()? Under the second scenario, we know calling Dog.drink() would call the Canine classes drink method as long as Dog had not overridden it.

Fatal error: Can't open and lock privilege tables: Table 'mysql.host' doesn't exist

  1. Uninstall mysql using yum remove mysql*

  2. Recursively delete /usr/bin/mysql and /var/lib/mysql

  3. Delete the file /etc/my.cnf.rmp

  4. Use ps -e to check the processes to make sure mysql isn't still running.

  5. Reboot server with reboot

  6. Run yum install mysql-server. This also seems to install the mysql client as a dependency.

  7. Give mysql ownership and group priveleges with:

    chown -R mysql /var/lib/mysql

    chgrp -R mysql /var/lib/mysql

  8. Use service mysqld start to start MySQL Daemon.

What does -> mean in C++?

a->b means (*a).b.

If a is a pointer, a->b is the member b of which a points to.

a can also be a pointer like object (like a vector<bool>'s stub) override the operators.

(if you don't know what a pointer is, you have another question)

Attach event to dynamic elements in javascript

You must attach the event after insert elements, like that you don't attach a global event on your document but a specific event on the inserted elements.

e.g.

_x000D_
_x000D_
document.getElementById('form').addEventListener('submit', function(e) {_x000D_
  e.preventDefault();_x000D_
  var name = document.getElementById('txtName').value;_x000D_
  var idElement = 'btnPrepend';_x000D_
  var html = `_x000D_
    <ul>_x000D_
      <li>${name}</li>_x000D_
    </ul>_x000D_
    <input type="button" value="prepend" id="${idElement}" />_x000D_
  `;_x000D_
  /* Insert the html into your DOM */_x000D_
  insertHTML('form', html);_x000D_
  /* Add an event listener after insert html */_x000D_
  addEvent(idElement);_x000D_
});_x000D_
_x000D_
const insertHTML = (tag = 'form', html, position = 'afterend', index = 0) => {_x000D_
  document.getElementsByTagName(tag)[index].insertAdjacentHTML(position, html);_x000D_
}_x000D_
const addEvent = (id, event = 'click') => {_x000D_
  document.getElementById(id).addEventListener(event, function() {_x000D_
    insertHTML('ul', '<li>Prepending data</li>', 'afterbegin')_x000D_
  });_x000D_
}
_x000D_
<form id="form">_x000D_
  <div>_x000D_
    <label for="txtName">Name</label>_x000D_
    <input id="txtName" name="txtName" type="text" />_x000D_
  </div>_x000D_
  <input type="submit" value="submit" />_x000D_
</form>
_x000D_
_x000D_
_x000D_

Access PHP variable in JavaScript

You can't, you'll have to do something like

<script type="text/javascript">
   var php_var = "<?php echo $php_var; ?>";
</script>

You can also load it with AJAX

rhino is right, the snippet lacks of a type for the sake of brevity.

Also, note that if $php_var has quotes, it will break your script. You shall use addslashes, htmlentities or a custom function.

GROUP_CONCAT comma separator - MySQL

Or, if you are doing a split - join:

GROUP_CONCAT(split(thing, " "), '----') AS thing_name,

You may want to inclue WITHIN RECORD, like this:

GROUP_CONCAT(split(thing, " "), '----') WITHIN RECORD AS thing_name,

from BigQuery API page

plotting different colors in matplotlib

for color in ['r', 'b', 'g', 'k', 'm']:
    plot(x, y, color=color)

How do you close/hide the Android soft keyboard using Java?

For the kotlin users out there here is a kotlin extension method that has worked for my use cases:

fun View.hideKeyboard() {
    val imm = this.context.getSystemService(Activity.INPUT_METHOD_SERVICE) as InputMethodManager
    imm.hideSoftInputFromWindow(windowToken, 0)
}

put it in a file called ViewExtensions (or what have you) and call it on your views just like a normal method.

Why do I get a SyntaxError for a Unicode escape in my file path?

All the three syntax work very well.

Another way is to first write

path = r'C:\user\...................' (whatever is the path for you)

and then passing it to os.chdir(path)

converting epoch time with milliseconds to datetime

those are miliseconds, just divide them by 1000, since gmtime expects seconds ...

time.strftime('%Y-%m-%d %H:%M:%S', time.gmtime(1236472051807/1000.0))

Convert Unix timestamp to a date string

As @TomMcKenzie says in a comment to another answer, date -r 123456789 is arguably a more common (i.e. more widely implemented) simple solution for times given as seconds since the Unix Epoch, but unfortunately there's no universal guaranteed portable solution.

The -d option on many types of systems means something entirely different than GNU Date's --date extension. Sadly GNU Date doesn't interpret -r the same as these other implementations. So unfortunately you have to know which version of date you're using, and many older Unix date commands don't support either option.

Even worse, POSIX date recognizes neither -d nor -r and provides no standard way in any command at all (that I know of) to format a Unix time from the command line (since POSIX Awk also lacks strftime()). (You can't use touch -t and ls because the former does not accept a time given as seconds since the Unix Epoch.)

Note though The One True Awk available direct from Brian Kernighan does now have the strftime() function built-in as well as a systime() function to return the current time in seconds since the Unix Epoch), so perhaps the Awk solution is the most portable.

Playing a MP3 file in a WinForm application

Refactoring:

new WindowsMediaPlayer() { URL = "MyMusic.mp3" }.controls.play();

NodeJS w/Express Error: Cannot GET /

In my case, the static content was already being served:

app.use('/*', express.static(path.join(__dirname, '../pub/index.html')));

...and everything in the app seemed to rely on that in some way. (path dep is require('path'))

So, a) yes, it can be a file; and b) you can make a redirect!

app.get('/', function (req, res) { res.redirect('/index.html') });

Now anyone hitting / gets /index.html which is served statically from ../pub/index.html.

Hope this helps someone else.

Redirecting to a page after submitting form in HTML

What you could do is, a validation of the values, for example:

if the value of the input of fullanme is greater than some value length and if the value of the input of address is greater than some value length then redirect to a new page, otherwise shows an error for the input.

_x000D_
_x000D_
// We access to the inputs by their id's
let fullname = document.getElementById("fullname");
let address = document.getElementById("address");

// Error messages
let errorElement = document.getElementById("name_error");
let errorElementAddress = document.getElementById("address_error");

// Form
let contactForm = document.getElementById("form");

// Event listener
contactForm.addEventListener("submit", function (e) {
  let messageName = [];
  let messageAddress = [];
  
    if (fullname.value === "" || fullname.value === null) {
    messageName.push("* This field is required");
  }

  if (address.value === "" || address.value === null) {
    messageAddress.push("* This field is required");
  }

  // Statement to shows the errors
  if (messageName.length || messageAddress.length > 0) {
    e.preventDefault();
    errorElement.innerText = messageName;
    errorElementAddress.innerText = messageAddress;
  }
  
   // if the values length is filled and it's greater than 2 then redirect to this page
    if (
    (fullname.value.length > 2,
    address.value.length > 2)
  ) {
    e.preventDefault();
    window.location.assign("https://www.google.com");
  }

});
_x000D_
.error {
  color: #000;
}

.input-container {
  display: flex;
  flex-direction: column;
  margin: 1rem auto;
}
_x000D_
<html>
  <body>
    <form id="form" method="POST">
    <div class="input-container">
    <label>Full name:</label>
      <input type="text" id="fullname" name="fullname">
      <div class="error" id="name_error"></div>
      </div>
      
      <div class="input-container">
      <label>Address:</label>
      <input type="text" id="address" name="address">
      <div class="error" id="address_error"></div>
      </div>
      <button type="submit" id="submit_button" value="Submit request" >Submit</button>
    </form>
  </body>
</html>
_x000D_
_x000D_
_x000D_

How to remove special characters from a string?

To Remove Special character

String t2 = "!@#$%^&*()-';,./?><+abdd";

t2 = t2.replaceAll("\\W+","");

Output will be : abdd.

This works perfectly.

Function is not defined - uncaught referenceerror

You must write that function body outside the ready();

because ready is used to call a function or to bind a function with binding id like this.

$(document).ready(function() {
    $("Some id/class name").click(function(){
        alert("i'm in");
    });
});

but you can't do this if you are calling "showAmount" function onchange/onclick event

$(document).ready(function() {
    function showAmount(value){
        alert(value);
    }

});

You have to write "showAmount" outside the ready();

function showAmount(value){
    alert(value);//will be called on event it is bind with
}
$(document).ready(function() {
    alert("will display on page load")
});

What are callee and caller saved registers?

The caller-saved / callee-saved terminology is based on a pretty braindead inefficient model of programming where callers actually do save/restore all the call-clobbered registers (instead of keeping long-term-useful values elsewhere), and callees actually do save/restore all the call-preserved registers (instead of just not using some or any of them).

Or you have to understand that "caller-saved" means "saved somehow if you want the value later".

In reality, efficient code lets values get destroyed when they're no longer needed. Compilers typically make functions that save a few call-preserved registers at the start of a function (and restore them at the end). Inside the function, they use those regs for values that need to survive across function calls.

I prefer "call-preserved" vs. "call-clobbered", which are unambiguous and self-describing once you've heard of the basic concept, and don't require any serious mental gymnastics to think about from the caller's perspective or the callee's perspective. (Both terms are from the same perspective).

Plus, these terms differ by more than one letter.

The terms volatile / non-volatile are pretty good, by analogy with storage which loses its value on power-loss or not, (like DRAM vs. Flash). But the C volatile keyword has a totally different technical meaning, so that's a downside to "(non)-volatile" when describing C calling conventions.


  • Call-clobbered, aka caller-saved or volatile registers are good for scratch / temporary values that aren't needed after the next function call.

From the callee's perspective, your function can freely overwrite (aka clobber) these registers without saving/restoring.

From a caller's perspective, call foo destroys (aka clobbers) all the call-clobbered registers, or at least you have to assume it does.

You can write private helper functions that have a custom calling convention, e.g. you know they don't modify a certain register. But if all you know (or want to assume or depend on) is that the target function follows the normal calling convention, then you have to treat a function call as if it does destroy all the call-clobbered registers. That's literally what the name come from: a call clobbers those registers.

Some compilers that do inter-procedural optimization can also create internal-use-only definitions of functions that don't follow the ABI, using a custom calling convention.

  • Call-preserved, aka callee-saved or non-volatile registers keep their values across function calls. This is useful for loop variables in a loop that makes function calls, or basically anything in a non-leaf function in general.

From a callee's perspective, these registers can't be modified unless you save the original value somewhere so you can restore it before returning. Or for registers like the stack pointer (which is almost always call-preserved), you can subtract a known offset and add it back again before returning, instead of actually saving the old value anywhere. i.e. you can restore it by dead reckoning, unless you allocate a runtime-variable amount of stack space. Then typically you restore the stack pointer from another register.

A function that can benefit from using a lot of registers can save/restore some call-preserved registers just so it can use them as more temporaries, even if it doesn't make any function calls. Normally you'd only do this after running out of call-clobbered registers to use, because save/restore typically costs a push/pop at the start/end of the function. (Or if your function has multiple exit paths, a pop in each of them.)


The name "caller-saved" is misleading: you don't have to specially save/restore them. Normally you arrange your code to have values that need to survive a function call in call-preserved registers, or somewhere on the stack, or somewhere else that you can reload from. It's normal to let a call destroy temporary values.


An ABI or calling convention defines which are which

See for example What registers are preserved through a linux x86-64 function call for the x86-64 System V ABI.

Also, arg-passing registers are always call-clobbered in all function-calling conventions I'm aware of. See Are rdi and rsi caller saved or callee saved registers?

But system-call calling conventions typically make all the registers except the return value call-preserved. (Usually including even condition-codes / flags.) See What are the calling conventions for UNIX & Linux system calls on i386 and x86-64

Resetting remote to a certain commit

Use the other answers if you don't mind losing local changes. This method can still wreck your remote if you choose the wrong commit hash to go back to.

If you just want to make the remote match a commit that's anywhere in your local repo:

  1. Do not do any resetting.
  2. Use git log to find the commit you want to the remote to be at. git log -p to see changes, or git log --graph --all --oneline --decorate to see a compact tree.
  3. Copy the commit's hash or its tag, or the name of its branch if it's the tip.
  4. Run a command like:

    git push --force <remote> <commit-ish>:<the remote branch>
    

    e.g.

    git push --force origin 606fdfaa33af1844c86f4267a136d4666e576cdc:master
    

    or

    git push --force staging v2.4.0b2:releases
    

I use convenient alias (git go) for viewing history as in step 2, which can be added like so:

    git config --global alias.go 'log --graph --all --decorate --oneline'`

Launch an app from within another (iPhone)

I found that it's easy to write an app that can open another app.

Let's assume that we have two apps called FirstApp and SecondApp. When we open the FirstApp, we want to be able to open the SecondApp by clicking a button. The solution to do this is:

  1. In SecondApp

    Go to the plist file of SecondApp and you need to add a URL Schemes with a string iOSDevTips(of course you can write another string.it's up to you).

enter image description here

2 . In FirstApp

Create a button with the below action:

- (void)buttonPressed:(UIButton *)button
{
  NSString *customURL = @"iOSDevTips://";

  if ([[UIApplication sharedApplication] canOpenURL:[NSURL URLWithString:customURL]])
  {
    [[UIApplication sharedApplication] openURL:[NSURL URLWithString:customURL]];
  }
  else
  {
    UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"URL error"
                              message:[NSString stringWithFormat:@"No custom URL defined for %@", customURL]
                              delegate:self cancelButtonTitle:@"Ok" 
                              otherButtonTitles:nil];
    [alert show];
  }

}

That's it. Now when you can click the button in the FirstApp it should open the SecondApp.

What are the rules about using an underscore in a C++ identifier?

From MSDN:

Use of two sequential underscore characters ( __ ) at the beginning of an identifier, or a single leading underscore followed by a capital letter, is reserved for C++ implementations in all scopes. You should avoid using one leading underscore followed by a lowercase letter for names with file scope because of possible conflicts with current or future reserved identifiers.

This means that you can use a single underscore as a member variable prefix, as long as it's followed by a lower-case letter.

This is apparently taken from section 17.4.3.1.2 of the C++ standard, but I can't find an original source for the full standard online.

See also this question.

Regular expression for decimal number

I just found TryParse() has an issue that it accounts for thousands seperator. Example in En-US, 10,36.00 is ok. I had a specific scenario where the thousands seperator should not be considered and hence regex \d(\.\d) turned out to be the best bet. Of course had to keep the decimal char variable for different locales.

Load different application.yml in SpringBoot Test

Starting with Spring 4.1, We can directly set the property in application.yml using the @TestPropertySource annotation.

@RunWith(SpringRunner.class)
@SpringBootTest
@TestPropertySource(properties = {"yoursection.yourparameter=your_value"})
public MyIntTest
{
 //your test methods
}

Just convert your yaml parameters into complete property structure. For example: If content of application.yml is like below

yoursection:
  yourparameter:your_value

Then value to go inside the @TestPropertySource will be,

yoursection.yourparameter=your_value

How do I get the current time only in JavaScript

Try

new Date().toLocaleTimeString().replace("/.*(\d{2}:\d{2}:\d{2}).*/", "$1");

Or

new Date().toTimeString().split(" ")[0];

For..In loops in JavaScript - key value pairs

Please try the below code:

<script> 
 const games = {
  "Fifa": "232",
  "Minecraft": "476",
  "Call of Duty": "182"
 };

Object.keys(games).forEach((item, index, array) => {
  var msg = item+' '+games[item];
  console.log(msg);
});

Rename multiple files in a directory in Python

It seems that your problem is more in determining the new file name rather than the rename itself (for which you could use the os.rename method).

It is not clear from your question what the pattern is that you want to be renaming. There is nothing wrong with string manipulation. A regular expression may be what you need here.

Boto3 to download all files from a S3 Bucket

When working with buckets that have 1000+ objects its necessary to implement a solution that uses the NextContinuationToken on sequential sets of, at most, 1000 keys. This solution first compiles a list of objects then iteratively creates the specified directories and downloads the existing objects.

import boto3
import os

s3_client = boto3.client('s3')

def download_dir(prefix, local, bucket, client=s3_client):
    """
    params:
    - prefix: pattern to match in s3
    - local: local path to folder in which to place files
    - bucket: s3 bucket with target contents
    - client: initialized s3 client object
    """
    keys = []
    dirs = []
    next_token = ''
    base_kwargs = {
        'Bucket':bucket,
        'Prefix':prefix,
    }
    while next_token is not None:
        kwargs = base_kwargs.copy()
        if next_token != '':
            kwargs.update({'ContinuationToken': next_token})
        results = client.list_objects_v2(**kwargs)
        contents = results.get('Contents')
        for i in contents:
            k = i.get('Key')
            if k[-1] != '/':
                keys.append(k)
            else:
                dirs.append(k)
        next_token = results.get('NextContinuationToken')
    for d in dirs:
        dest_pathname = os.path.join(local, d)
        if not os.path.exists(os.path.dirname(dest_pathname)):
            os.makedirs(os.path.dirname(dest_pathname))
    for k in keys:
        dest_pathname = os.path.join(local, k)
        if not os.path.exists(os.path.dirname(dest_pathname)):
            os.makedirs(os.path.dirname(dest_pathname))
        client.download_file(bucket, k, dest_pathname)

Static Block in Java

yes, static block is used for initialize the code and it will load at the time JVM start for execution.

static block is used in previous versions of java but in latest version it doesn't work.

How can I remove item from querystring in asp.net using c#?

Get the querystring collection, parse it into a (name=value pair) string, excluding the one you want to REMOVE, and name it newQueryString

Then call Response.Redirect(known_path?newqueryString);

Check if array is empty or null

You should check for '' (empty string) before pushing into your array. Your array has elements that are empty strings. Then your album_text.length === 0 will work just fine.

Possible to perform cross-database queries with PostgreSQL?

Note: As the original asker implied, if you are setting up two databases on the same machine you probably want to make two schemas instead - in that case you don't need anything special to query across them.

postgres_fdw

Use postgres_fdw (foreign data wrapper) to connect to tables in any Postgres database - local or remote.

Note that there are foreign data wrappers for other popular data sources. At this time, only postgres_fdw and file_fdw are part of the official Postgres distribution.

For Postgres versions before 9.3

Versions this old are no longer supported, but if you need to do this in a pre-2013 Postgres installation, there is a function called dblink.

I've never used it, but it is maintained and distributed with the rest of PostgreSQL. If you're using the version of PostgreSQL that came with your Linux distro, you might need to install a package called postgresql-contrib.

Difference between "managed" and "unmanaged"

Managed code is a differentiation coined by Microsoft to identify computer program code that requires and will only execute under the "management" of a Common Language Runtime virtual machine (resulting in Bytecode).

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

http://www.developer.com/net/cplus/article.php/2197621/Managed-Unmanaged-Native-What-Kind-of-Code-Is-This.htm

Copy existing project with a new name in Android Studio

If you are using the newest version of Android Studio, you can let it assist you in this.

Note: I have tested this in Android Studio 3.0 only.

The procedure is as follows:

  1. In the project view (this comes along with captures and structure on the left side of screen), select Project instead of Android.
    The name of your project will be the top of the tree (alongside external libraries).
    Select your project then go to Refactor -> Copy....
    Android Studio will ask you the new name and where you want to copy the project. Provide the same.

  2. After the copying is done, open your new project in Android Studio.
    Packages will still be under the old project name.
    That is the Java classes packages, application ID and everything else that was generated using the old package name.
    We need to change that.
    In the project view, select Android.
    Open the java sub-directory and select the main package.
    Then right click on it and go to Refactor then Rename.
    Android Studio will give you a warning saying that multiple directories correspond to the package you are about to refactor.
    Click on Rename package and not Rename directory.
    After this step, your project is now completely under the new name.

  3. Open up the res/values/strings.xml file, and change the name of the project.
  4. Don't forget to change your application ID in the "Gradle Build Module: app".
  5. A last step is to clean and rebuild the project otherwise when trying to run your project Android Studio will tell you it can't install the APK (if you ran the previous project).
    So Build -> Clean project then Build -> Rebuild project.
    Now you can run your new cloned project.

How to edit Docker container files from the host?

Here's the script I use:

#!/bin/bash
IFS=$'\n\t'
set -euox pipefail


CNAME="$1"
FILE_PATH="$2"

TMPFILE="$(mktemp)"
docker exec "$CNAME" cat "$FILE_PATH" > "$TMPFILE"
$EDITOR "$TMPFILE"
cat "$TMPFILE" | docker exec -i "$CNAME" sh -c 'cat > '"$FILE_PATH"
rm "$TMPFILE"

and the gist for when I fix it but forget to update this answer: https://gist.github.com/dmohs/b50ea4302b62ebfc4f308a20d3de4213

os.walk without digging into directories below

I think the solution is actually very simple.

use

break

to only do first iteration of the for loop, there must be a more elegant way.

for root, dirs, files in os.walk(dir_name):
    for f in files:
        ...
        ...
    break
...

The first time you call os.walk, it returns tulips for the current directory, then on next loop the contents of the next directory.

Take original script and just add a break.

def _dir_list(self, dir_name, whitelist):
    outputList = []
    for root, dirs, files in os.walk(dir_name):
        for f in files:
            if os.path.splitext(f)[1] in whitelist:
                outputList.append(os.path.join(root, f))
            else:
                self._email_to_("ignore")
        break
    return outputList

Is there a git-merge --dry-run option?

Undoing a merge with git is so easy you shouldn't even worry about the dry run:

$ git pull $REMOTE $BRANCH
# uh oh, that wasn't right
$ git reset --hard ORIG_HEAD
# all is right with the world

EDIT: As noted in the comments below, if you have changes in your working directory or staging area you'll probably want to stash them before doing the above (otherwise they will disappear following the git reset above)

How do I get values from a SQL database into textboxes using C#?

Make a connection and open it.

con = new OracleConnection("Data Source=(DESCRIPTION=(ADDRESS_LIST=(ADDRESS=(PROTOCOL=TCP)(HOST=localhost)(PORT=1521)))(CONNECT_DATA=(SERVER=DEDICATED)(SERVICE_NAME=<database_name>)));User Id =<userid>; Password =<password>");
con.Open();

Write the select query:

string sql = "select * from Pending_Tasks";

Create a command object:

OracleCommand cmd = new OracleCommand(sql, con);

Execute the command and put the result in a object to read it.

OracleDataReader r = cmd.ExecuteReader();

now start reading from it.

while (read.Read())
{
 CustID.Text = (read["Customer_ID"].ToString());
 CustName.Text = (read["Customer_Name"].ToString());
 Add1.Text = (read["Address_1"].ToString());
 Add2.Text = (read["Address_2"].ToString());
 PostBox.Text = (read["Postcode"].ToString());
 PassBox.Text = (read["Password"].ToString());
 DatBox.Text = (read["Data_Important"].ToString());
 LanNumb.Text = (read["Landline"].ToString());
 MobNumber.Text = (read["Mobile"].ToString());
 FaultRep.Text = (read["Fault_Report"].ToString());
}
read.Close();

Add this too using Oracle.ManagedDataAccess.Client;

Invalid argument supplied for foreach()

There seems also to be a relation to the environment:

I had that "invalid argument supplied foreach()" error only in the dev environment, but not in prod (I am working on the server, not localhost).

Despite the error a var_dump indicated that the array was well there (in both cases app and dev).

The if (is_array($array)) around the foreach ($array as $subarray) solved the problem.

Sorry, that I cannot explain the cause, but as it took me a while to figure a solution I thought of better sharing this as an observation.

WARNING: sanitizing unsafe style value url

There is an open issue to only print this warning if there was actually something sanitized: https://github.com/angular/angular/pull/10272

I didn't read in detail when this warning is printed when nothing was sanitized.

Making the iPhone vibrate

For an iPhone 7/7 Plus or newer, use these three Haptic feedback APIs.

Available APIs

For notifications:

let generator = UINotificationFeedbackGenerator()
generator.notificationOccured(style: .error)

Available styles are .error, .success, and .warning. Each has its own distinctive feel.
From the docs:

A concrete UIFeedbackGenerator subclass that creates haptics to communicate successes, failures, and warnings.

For simple vibrations:

let generator = UIImpactFeedbackGenerator(style: .medium)
generator.impactOccured()

Available styles are .heavy, .medium, and .light. These are simple vibrations with varying degrees of "hardness".
From the docs:

A concrete UIFeedbackGenerator subclass that creates haptics to simulate physical impacts

For when the user selected an item

let generator = UISelectionFeedbackGenerator()
generator.selectionChanged()

This is the least noticeable of all the haptics, and so is the most suitable for when haptics should not be taking over the app experience.
From the docs:

A concrete UIFeedbackGenerator subclass that creates haptics to indicate a change in selection.

Notes

There are a couple of things worth remembering when using these APIs.

Note A

You do not actually create the haptic. You request the system generate a haptic. The system will decide based on the below:

  • If haptics are possible on the device (whether it has a Taptic Engine in this case)
  • Whether the app may record audio (haptics do not generate during recording to prevent unwanted interference)
  • Whether haptics are enabled in system Settings.

Therefore, the system will silently ignore your request for a haptic if it is not possible. If this is due to an unsupported device, you could try this:

func haptic() {
    // Get whether the device can generate haptics or not
    // If feedbackSupportLevel is nil, will assign 0
    let feedbackSupportLevel = UIDevice.current.value(forKey: "_feedbackSupportLevel") as? Int ?? 0

    switch feedbackSupportLevel { 
    case 2:
        // 2 means the device has a Taptic Engine
        // Put Taptic Engine code here, using the APIs explained above

    case 1: 
    // 1 means no Taptic Engine, but will support AudioToolbox
    // AudioToolbox code from the myriad of other answers!

    default: // 0
        // No haptic support
        // Do something else, like a beeping noise or LED flash instead of haptics
    }

Substitute the comments in the switch-case statements, and this haptic generation code will be portable to other iOS devices. It will generate the highest level of haptic possible.

Note B

  • Due to the fact that generating haptics is a hardware-level task, there may be latency between when you call the haptic-generation code, and when it actually happens. For this reason, the Taptic Engine APIs all have a prepare() method, to put it in a state of readiness. Using your Game Over example: You may know that the game is about to end, by the user having very low HP, or a dangerous monster being near them.
  • If you don't generate a haptic within a few seconds, the Taptic Engine will go back into an idle state (to save battery life)


In this case, preparing the Taptic Engine would create a higher-quality, more responsive experience.

For example, let's say your app uses a pan gesture recogniser to change the portion of the world visible. You want a haptic to generate when the user 'looks' round 360 degrees. Here is how you could use prepare():

@IBAction func userChangedViewablePortionOfWorld(_ gesture: UIPanGestureRecogniser!) {

    haptic = UIImpactFeedbackGenerator(style: .heavy)

    switch gesture.state {
        case .began:
            // The user started dragging the screen.
            haptic.prepare()

        case .changed:
            // The user trying to 'look' in another direction
            // Code to change viewable portion of the virtual world

            if virtualWorldViewpointDegreeMiddle = 360.0 { 
                haptic.impactOccured()
            }
        
        default:
            break

} 

Eclipse: How to install a plugin manually?

You can try this

click Help>Install New Software on the menu bar

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