Programs & Examples On #Loaddata

How to call loading function with React useEffect only once

function useOnceCall(cb, condition = true) {
  const isCalledRef = React.useRef(false);

  React.useEffect(() => {
    if (condition && !isCalledRef.current) {
      isCalledRef.current = true;
      cb();
    }
  }, [cb, condition]);
}

and use it.

useOnceCall(()=>{
  console.log('called');
})

or

useOnceCall(()=>{
  console.log('isLoading');
},isLoading);

Swift 3 URLSession.shared() Ambiguous reference to member 'dataTask(with:completionHandler:) error (bug)

Xcode 10.1 Swift 4

This worked for me:

let task: URLSessionDataTask = session.dataTask(with: request as URLRequest) { (data, response, error) -> Void in
...

The key was adding in the URLSessionDataTask type declaration.

How to fix Error: this class is not key value coding-compliant for the key tableView.'

Any chance that you changed the name of your table view from "tableView" to "myTableView" at some point?

Dynamic Height Issue for UITableView Cells (Swift)

You should just set all constraints for TOP, BOTTOM and HEIGHT for each object on cell view/views and remove exists middle Y position if have. Because where you didn't this, puts artifacts on another views.

unable to dequeue a cell with identifier Cell - must register a nib or a class for the identifier or connect a prototype cell in a storyboard

Just for those new to iOS buddies (like me) who decided to have multiple cells and in a different xib file, the solution is not to have identifier but to do this:

let cell = Bundle.main.loadNibNamed("newsDetails", owner: self, options: nil)?.first as! newsDetailsTableViewCell

here newsDetails is xib file name.

JQuery Datatables : Cannot read property 'aDataSort' of undefined

Also had this issue, This array was out of range:

order: [1, 'asc'],

Convert array to JSON string in swift

You can try this.

func convertToJSONString(value: AnyObject) -> String? {
        if JSONSerialization.isValidJSONObject(value) {
            do{
                let data = try JSONSerialization.data(withJSONObject: value, options: [])
                if let string = NSString(data: data, encoding: String.Encoding.utf8.rawValue) {
                    return string as String
                }
            }catch{
            }
        }
        return nil
    }

Bootstrap modal in React.js

You can try this modal:https://github.com/xue2han/react-dynamic-modal It is stateless and can be rendered only when needed.So it is very easy to use.Just like this:

    class MyModal extends Component{
       render(){
          const { text } = this.props;
          return (
             <Modal
                onRequestClose={this.props.onRequestClose}
                openTimeoutMS={150}
                closeTimeoutMS={150}
                style={customStyle}>
                <h1>What you input : {text}</h1>
                <button onClick={ModalManager.close}>Close Modal</button>
             </Modal>
          );
       }
    }

    class App extends Component{
        openModal(){
           const text = this.refs.input.value;
           ModalManager.open(<MyModal text={text} onRequestClose={() => true}/>);
        }
        render(){
           return (
              <div>
                <div><input type="text" placeholder="input something" ref="input" /></div>
                <div><button type="button" onClick={this.openModal.bind(this)}>Open Modal </button> </div>
              </div>
           );
        }
    }

    ReactDOM.render(<App />,document.getElementById('main'));

UICollectionView - dynamic cell height?

Swift 4 answer based on helpful answer from @mbm29414.

Unfortunately, it requires the use of a XIB file. There doesn't appear to be an alternative.

The key parts are using a sizing cell (created only once) and registering the XIB when initializing the collection view.

Then you size each cell dynamically within the sizeForItemAt function.

// UICollectionView Vars and Constants
let CellXIBName = YouViewCell.XIBName
let CellReuseID = YouViewCell.ReuseID
var sizingCell = YouViewCell()


fileprivate func initCollectionView() {
    // Connect to view controller
    collectionView.dataSource = self
    collectionView.delegate = self

    // Register XIB
    collectionView.register(UINib(nibName: CellXIBName, bundle: nil), forCellWithReuseIdentifier: CellReuseID)

    // Create sizing cell for dynamically sizing cells
    sizingCell = Bundle.main.loadNibNamed(CellXIBName, owner: self, options: nil)?.first as! YourViewCell

    // Set scroll direction
    let layout = UICollectionViewFlowLayout()
    layout.scrollDirection = .vertical
    collectionView.collectionViewLayout = layout

    // Set properties
    collectionView.alwaysBounceVertical = true
    collectionView.alwaysBounceHorizontal = false

    // Set top/bottom padding
    collectionView.contentInset = UIEdgeInsets(top: collectionViewTopPadding, left: collectionViewSidePadding, bottom: collectionViewBottomPadding, right: collectionViewSidePadding)

    // Hide scrollers
    collectionView.showsVerticalScrollIndicator = false
    collectionView.showsHorizontalScrollIndicator = false
}


func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
    // Get cell data and render post
    let data = YourData[indexPath.row]
    sizingCell.renderCell(data: data)

    // Get cell size
    sizingCell.setNeedsLayout()
    sizingCell.layoutIfNeeded()
    let cellSize = sizingCell.systemLayoutSizeFitting(UIView.layoutFittingCompressedSize)

    // Return cell size
    return cellSize
}

How to use pull to refresh in Swift?

you can use this subclass of tableView:

import UIKit

protocol PullToRefreshTableViewDelegate : class {
    func tableViewDidStartRefreshing(tableView: PullToRefreshTableView)
}

class PullToRefreshTableView: UITableView {

    @IBOutlet weak var pullToRefreshDelegate: AnyObject?
    private var refreshControl: UIRefreshControl!
    private var isFirstLoad = true

    override func willMoveToSuperview(newSuperview: UIView?) {
        super.willMoveToSuperview(newSuperview)

        if (isFirstLoad) {
            addRefreshControl()
            isFirstLoad = false
        }
    }

    private func addRefreshControl() {
        refreshControl = UIRefreshControl()
        refreshControl.attributedTitle = NSAttributedString(string: "Pull to refresh")
        refreshControl.addTarget(self, action: "refresh", forControlEvents: .ValueChanged)
        self.addSubview(refreshControl)
    }

    @objc private func refresh() {
       (pullToRefreshDelegate as? PullToRefreshTableViewDelegate)?.tableViewDidStartRefreshing(self)
    }

    func endRefreshing() {
        refreshControl.endRefreshing()
    }

}

1 - in interface builder change the class of your tableView to PullToRefreshTableView or create a PullToRefreshTableView programmatically

2 - implement the PullToRefreshTableViewDelegate in your view controller

3 - tableViewDidStartRefreshing(tableView: PullToRefreshTableView) will be called in your view controller when the table view starts refreshing

4 - call yourTableView.endRefreshing() to finish the refreshing

self.tableView.reloadData() not working in Swift

You have just to enter:

First a IBOutlet:

@IBOutlet var appsTableView : UITableView

Then in a Action func:

self.appsTableView.reloadData()

Add swipe to delete UITableViewCell

Another way that allows you to change the text of "Delete" and add more buttons when sliding a cell is to use editActionsForRowAtIndexPath.

func tableView(tableView: UITableView, canEditRowAtIndexPath indexPath: NSIndexPath) -> Bool {
    return true
}

func tableView(tableView: (UITableView!), commitEditingStyle editingStyle: UITableViewCellEditingStyle, forRowAtIndexPath indexPath: (NSIndexPath!)) {

}

func tableView(tableView: UITableView, editActionsForRowAtIndexPath indexPath: NSIndexPath) -> [AnyObject]? {

    var deleteAction = UITableViewRowAction(style: .Default, title: "Delete") {action in
       //handle delete
    }

    var editAction = UITableViewRowAction(style: .Normal, title: "Edit") {action in
        //handle edit
    }

    return [deleteAction, editAction]
}

canEditRowAtIndexPath and commitEditingStyle are still required, but you can leave commitEditingStyle empty since deletion is handled in editActionsForRowAtIndexPath.

Deciding between HttpClient and WebClient

Firstly, I am not an authority on WebClient vs. HttpClient, specifically. Secondly, from your comments above, it seems to suggest that WebClient is Sync ONLY whereas HttpClient is both.

I did a quick performance test to find how WebClient (Sync calls), HttpClient (Sync and Async) perform. and here are the results.

I see that as a huge difference when thinking for future, i.e. long running processes, responsive GUI, etc. (add to the benefit you suggest by framework 4.5 - which in my actual experience is hugely faster on IIS)

[Ljava.lang.Object; cannot be cast to

You need to add query.addEntity(SwitcherServiceSource.class) before calling the .list() on query.

How to get coordinates of an svg element?

You can use the function getBBox() to get the bounding box for the path. This will give you the position and size of the tightest rectangle that could contain the rendered path.

An advantage of using this method over reading the x and y values is that it will work with all graphical objects. There are more objects than paths that do not have x and y, for example circles that have cx and cy instead.

Android findViewById() in Custom View

If it's fixed layout you can do like that:

public void onClick(View v) {
   ViewGroup parent = (ViewGroup) IdNumber.this.getParent();
   EditText firstName = (EditText) parent.findViewById(R.id.display_name);
   firstName.setText("Some Text");
}

If you want find the EditText in flexible layout, I will help you later. Hope this help.

xml.LoadData - Data at the root level is invalid. Line 1, position 1

At first I had problems escaping the "&" character, then diacritics and special letters were shown as question marks and ended up with the issue OP mentioned.

I looked at the answers and I used @Ringo's suggestion to try Load() method as an alternative. That made me realize that I can deal with my response in other ways not just as a string.

using System.IO.Stream instead of string solved all the issues for me.

var response = await this.httpClient.GetAsync(url);
var responseStream = await response.Content.ReadAsStreamAsync();
var xmlDocument = new XmlDocument();
xmlDocument.Load(responseStream);

The cool thing about Load() is that this method automatically detects the string format of the input XML (for example, UTF-8, ANSI, and so on). See more

UITableView with fixed section headers

to make UITableView sections header not sticky or sticky:

  1. change the table view's style - make it grouped for not sticky & make it plain for sticky section headers - do not forget: you can do it from storyboard without writing code. (click on your table view and change it is style from the right Side/ component menu)

  2. if you have extra components such as custom views or etc. please check the table view's margins to create appropriate design. (such as height of header for sections & height of cell at index path, sections)

Embed Youtube video inside an Android app

Pretty simple: Just put it inside a static method.

startActivity(new Intent(Intent.ACTION_VIEW, Uri.parse(linkYouTube)));

Async image loading from url inside a UITableView cell - image changes to wrong image while scrolling

 - (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath 
{
        MyCell *cell = [tableView dequeueReusableCellWithIdentifier:@"cell" forIndexPath:indexPath];

        cell.poster.image = nil; // or cell.poster.image = [UIImage imageNamed:@"placeholder.png"];

        NSURL *url = [NSURL URLWithString:[NSString stringWithFormat:@"http://myurl.com/%@.jpg", self.myJson[indexPath.row][@"movieId"]]];

        NSURLSessionTask *task = [[NSURLSession sharedSession] dataTaskWithURL:url completionHandler:^(NSData * _Nullable data, NSURLResponse * _Nullable response, NSError * _Nullable error) {
            if (data) {
                UIImage *image = [UIImage imageWithData:data];
                if (image) {
                    dispatch_async(dispatch_get_main_queue(), ^{
                        MyCell *updateCell = (id)[tableView cellForRowAtIndexPath:indexPath];
                        if (updateCell)
                            updateCell.poster.image = image;
                    });
                }
            }
        }];
        [task resume];

        return cell;
    }

Excel VBA Run-time error '424': Object Required when trying to copy TextBox

The issue is with this line

 xlo.Worksheets(1).Cells(2, 2) = TextBox1.Text

You have the textbox defined at some other location which you are not using here. Excel is unable to find the textbox object in the current sheet while this textbox was defined in xlw.

Hence replace this with

 xlo.Worksheets(1).Cells(2, 2) = worksheets("xlw").TextBox1.Text 

How to tell when UITableView has completed ReloadData?

And a UICollectionView version, based on kolaworld's answer:

https://stackoverflow.com/a/43162226/1452758

Needs testing. Works so far on iOS 9.2, Xcode 9.2 beta 2, with scrolling a collectionView to an index, as a closure.

extension UICollectionView
{
    /// Calls reloadsData() on self, and ensures that the given closure is
    /// called after reloadData() has been completed.
    ///
    /// Discussion: reloadData() appears to be asynchronous. i.e. the
    /// reloading actually happens during the next layout pass. So, doing
    /// things like scrolling the collectionView immediately after a
    /// call to reloadData() can cause trouble.
    ///
    /// This method uses CATransaction to schedule the closure.

    func reloadDataThenPerform(_ closure: @escaping (() -> Void))
    {       
        CATransaction.begin()
            CATransaction.setCompletionBlock(closure)
            self.reloadData()
        CATransaction.commit()
    }
}

Usage:

myCollectionView.reloadDataThenPerform {
    myCollectionView.scrollToItem(at: indexPath,
            at: .centeredVertically,
            animated: true)
}

C# refresh DataGridView when updating or inserted on another form

my datagridview is editonEnter mode . so it refresh only after i leave cell or after i revisit and exit cell twice.

to trigger this iimedately . i unfocus from datagridview . then refocus it.

 this.SelectNextControl(dgv1,true,true,false,true);    
 Application.DoEvents();    //this does magic
 dgv1.Focus();

POSTing JSON to URL via WebClient in C#

The question is already answered but I think I've found the solution that is simpler and more relevant to the question title, here it is:

var cli = new WebClient();
cli.Headers[HttpRequestHeader.ContentType] = "application/json";
string response = cli.UploadString("http://some/address", "{some:\"json data\"}");

PS: In the most of .net implementations, but not in all WebClient is IDisposable, so of cource it is better to do 'using' or 'Dispose' on it. However in this particular case it is not really necessary.

Change UITableView height dynamically

Lots of the answers here don't honor changes of the table or are way too complicated. Using a subclass of UITableView that will properly set intrinsicContentSize is a far easier solution when using autolayout. No height constraints etc. needed.

class UIDynamicTableView: UITableView
{
    override var intrinsicContentSize: CGSize {
        self.layoutIfNeeded()
        return CGSize(width: UIViewNoIntrinsicMetric, height: self.contentSize.height)
    }

    override func reloadData() {
        super.reloadData()
        self.invalidateIntrinsicContentSize()
    }
} 

Set the class of your TableView to UIDynamicTableView in the interface builder and watch the magic as this TableView will change it's size after a call to reloadData().

How to load html string in a webview?

I had the same requirement and I have done this in following way.You also can try out this..

Use loadData method

web.loadData("<p style='text-align:center'><img class='aligncenter size-full wp-image-1607' title='' src="+movImage+" alt='' width='240px' height='180px' /></p><p><center><U><H2>"+movName+"("+movYear+")</H2></U></center></p><p><strong>Director : </strong>"+movDirector+"</p><p><strong>Producer : </strong>"+movProducer+"</p><p><strong>Character : </strong>"+movActedAs+"</p><p><strong>Summary : </strong>"+movAnecdotes+"</p><p><strong>Synopsis : </strong>"+movSynopsis+"</p>\n","text/html", "UTF-8");

movDirector movProducer like all are my string variable.

In short i retain custom styling for my url.

Call parent method from child class c#

To follow up on the comment by suhendri to Rory McCrossan answer. Here is an Action delegate example:

In child add:

public Action UpdateProgress;  // In place of event handler declaration
                               // declare an Action delegate
.
.
.
private LoadData() {
    this.UpdateProgress();    // call to Action delegate - MyMethod in
                              // parent
}

In parent add:

// The 3 lines in the parent becomes:
ChildClass child = new ChildClass();
child.UpdateProgress = this.MyMethod;  // assigns MyMethod to child delegate

How to return a file using Web API?

I've been wondering if there was a simple way to download a file in a more ... "generic" way. I came up with this.

It's a simple ActionResult that will allow you to download a file from a controller call that returns an IHttpActionResult. The file is stored in the byte[] Content. You can turn it into a stream if needs be.

I used this to return files stored in a database's varbinary column.

    public class FileHttpActionResult : IHttpActionResult
    {
        public HttpRequestMessage Request { get; set; }

        public string FileName { get; set; }
        public string MediaType { get; set; }
        public HttpStatusCode StatusCode { get; set; }

        public byte[] Content { get; set; }

        public Task<HttpResponseMessage> ExecuteAsync(CancellationToken cancellationToken)
        {
            HttpResponseMessage response = new HttpResponseMessage(StatusCode);

            response.StatusCode = StatusCode;
            response.Content = new StreamContent(new MemoryStream(Content));
            response.Content.Headers.ContentDisposition = new ContentDispositionHeaderValue("attachment");
            response.Content.Headers.ContentDisposition.FileName = FileName;
            response.Content.Headers.ContentType = new MediaTypeHeaderValue(MediaType);

            return Task.FromResult(response);
        }
    }

How can I solve "Non-static method xxx:xxx() should not be called statically in PHP 5.4?

I don't suggest you just hidding the stricts errors on your project. Intead, you should turn your method to static or try to creat a new instance of the object:

$var = new YourClass();
$var->method();

You can also use the new way to do the same since PHP 5.4:

(new YourClass)->method();

I hope it helps you!

Xcode error - Thread 1: signal SIGABRT

SIGABRT is, as stated in other answers, a general uncaught exception. You should definitely learn a little bit more about Objective-C. The problem is probably in your UITableViewDelegate method didSelectRowAtIndexPath.

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath

I can't tell you much more until you show us something of the code where you handle the table data source and delegate methods.

how to get html content from a webview?

I would suggest instead of trying to extract the HTML from the WebView, you extract the HTML from the URL. By this, I mean using a third party library such as JSoup to traverse the HTML for you. The following code will get the HTML from a specific URL for you

public static String getHtml(String url) throws ClientProtocolException, IOException {
        HttpClient httpClient = new DefaultHttpClient();
        HttpContext localContext = new BasicHttpContext();
        HttpGet httpGet = new HttpGet(url);
        HttpResponse response = httpClient.execute(httpGet, localContext);
        String result = "";

        BufferedReader reader = new BufferedReader(
            new InputStreamReader(
                response.getEntity().getContent()
            )
        );

        String line = null;
        while ((line = reader.readLine()) != null){
            result += line + "\n";
        }
        return result;
    }

How to disable scrolling in UITableView table when the content fits on the screen

You can verify the number of visible cells using this function:

- (NSArray *)visibleCells

This method will return an array with the cells that are visible, so you can count the number of objects in this array and compare with the number of objects in your table.. if it's equal.. you can disable the scrolling using:

tableView.scrollEnabled = NO;

As @Ginny mentioned.. we would can have problems with partially visible cells, so this solution works better in this case:

tableView.scrollEnabled = (tableView.contentSize.height <= CGRectGetHeight(tableView.frame));

In case you are using autoLayout this solution do the job:

tableView.alwaysBounceVertical = NO.

How to load local html file into UIWebView

EDIT 2016-05-27 - loadRequest exposes "a universal Cross-Site Scripting vulnerability." Make sure you own every single asset that you load. If you load a bad script, it can load anything it wants.

If you need relative links to work locally, use this:

NSURL *url = [[NSBundle mainBundle] URLForResource:@"my" withExtension:@"html"];
[webView loadRequest:[NSURLRequest requestWithURL:url]];

The bundle will search all subdirectories of the project to find my.html. (the directory structure gets flattened at build time)

If my.html has the tag <img src="some.png">, the webView will load some.png from your project.

Rendering HTML in a WebView with custom CSS

I assume that your style-sheet "style.css" is already located in the assets-folder

  1. load the web-page with jsoup:

    doc = Jsoup.connect("http://....").get();
    
  2. remove links to external style-sheets:

    // remove links to external style-sheets
    doc.head().getElementsByTag("link").remove();
    
  3. set link to local style-sheet:

    // set link to local stylesheet
    // <link rel="stylesheet" type="text/css" href="style.css" />
    doc.head().appendElement("link").attr("rel", "stylesheet").attr("type", "text/css").attr("href", "style.css");
    
  4. make string from jsoup-doc/web-page:

    String htmldata = doc.outerHtml();
    
  5. display web-page in webview:

    WebView webview = new WebView(this);
    setContentView(webview);
    webview.loadDataWithBaseURL("file:///android_asset/.", htmlData, "text/html", "UTF-8", null);
    

Android. WebView and loadData

As I understand it, loadData() simply generates a data: URL with the data provide it.

Read the javadocs for loadData():

If the value of the encoding parameter is 'base64', then the data must be encoded as base64. Otherwise, the data must use ASCII encoding for octets inside the range of safe URL characters and use the standard %xx hex encoding of URLs for octets outside that range. For example, '#', '%', '\', '?' should be replaced by %23, %25, %27, %3f respectively.

The 'data' scheme URL formed by this method uses the default US-ASCII charset. If you need need to set a different charset, you should form a 'data' scheme URL which explicitly specifies a charset parameter in the mediatype portion of the URL and call loadUrl(String) instead. Note that the charset obtained from the mediatype portion of a data URL always overrides that specified in the HTML or XML document itself.

Therefore, you should either use US-ASCII and escape any special characters yourself, or just encode everything using Base64. The following should work, assuming you use UTF-8 (I haven't tested this with latin1):

String data = ...;  // the html data
String base64 = android.util.Base64.encodeToString(data.getBytes("UTF-8"), android.util.Base64.DEFAULT);
webView.loadData(base64, "text/html; charset=utf-8", "base64");

How to retrieve JSON Data Array from ExtJS Store

A better (IMO) one-line approach, works on ExtJS 4, not sure about 3:

store.proxy.reader.jsonData

Display loading image while post with ajax

make sure to change in ajax call

async: true,
type: "GET",
dataType: "html",

Create a custom callback in JavaScript

It is good practice to make sure the callback is an actual function before attempting to execute it:

if (callback && typeof(callback) === "function") {

  callback();
}

How to [recursively] Zip a directory in PHP?

Following @user2019515 answer, I needed to handle exclusions to my archive. here is the resulting function with an example.

Zip Function :

function Zip($source, $destination, $include_dir = false, $exclusions = false){
    // Remove existing archive
    if (file_exists($destination)) {
        unlink ($destination);
    }

    $zip = new ZipArchive();
    if (!$zip->open($destination, ZIPARCHIVE::CREATE)) {
        return false;
    }
    $source = str_replace('\\', '/', realpath($source));
    if (is_dir($source) === true){
        $files = new RecursiveIteratorIterator(new RecursiveDirectoryIterator($source), RecursiveIteratorIterator::SELF_FIRST);
        if ($include_dir) {
            $arr = explode("/",$source);
            $maindir = $arr[count($arr)- 1];
            $source = "";
            for ($i=0; $i < count($arr) - 1; $i++) {
                $source .= '/' . $arr[$i];
            }
            $source = substr($source, 1);
            $zip->addEmptyDir($maindir);
        }
        foreach ($files as $file){
            // Ignore "." and ".." folders
            $file = str_replace('\\', '/', $file);
            if(in_array(substr($file, strrpos($file, '/')+1), array('.', '..'))){
                continue;
            }

            // Add Exclusion
            if(($exclusions)&&(is_array($exclusions))){
                if(in_array(str_replace($source.'/', '', $file), $exclusions)){
                    continue;
                }
            }

            $file = realpath($file);
            if (is_dir($file) === true){
                $zip->addEmptyDir(str_replace($source . '/', '', $file . '/'));
            } elseif (is_file($file) === true){
                $zip->addFromString(str_replace($source . '/', '', $file), file_get_contents($file));
            }
        }
    } elseif (is_file($source) === true){
        $zip->addFromString(basename($source), file_get_contents($source));
    }
    return $zip->close();
}

How to use it :

function backup(){
    $backup = 'tmp/backup-'.$this->site['version'].'.zip';
    $exclusions = [];
    // Excluding an entire directory
    $files = new RecursiveIteratorIterator(new RecursiveDirectoryIterator('tmp/'), RecursiveIteratorIterator::SELF_FIRST);
    foreach ($files as $file){
        array_push($exclusions,$file);
    }
    // Excluding a file
    array_push($exclusions,'config/config.php');
    // Excluding the backup file
    array_push($exclusions,$backup);
    $this->Zip('.',$backup, false, $exclusions);
}

Have a reloadData for a UITableView animate when changing

Actually, it's very simple:

[_tableView reloadSections:[NSIndexSet indexSetWithIndex:0] withRowAnimation:UITableViewRowAnimationFade];

From the documentation:

Calling this method causes the table view to ask its data source for new cells for the specified sections. The table view animates the insertion of new cells in as it animates the old cells out.

How can I create a dynamically sized array of structs?

Another option for you is a linked list. You'll need to analyze how your program will use the data structure, if you don't need random access it could be faster than reallocating.

Cross-thread operation not valid: Control accessed from a thread other than the thread it was created on

Action y; //declared inside class

label1.Invoke(y=()=>label1.Text="text");

NHibernate.MappingException: No persister for: XYZ

I got this off of here:

In my case the mapping class was not public. In other words, instead of:

public class UserMap : ClassMap<user>  // note the public!

I just had:

class UserMap : ClassMap<user>

How to get row number in dataframe in Pandas?

To get all indices that matches 'Smith'

>>> df[df['LastName'] == 'Smith'].index
Int64Index([1], dtype='int64')

or as a numpy array

>>> df[df['LastName'] == 'Smith'].index.to_numpy()  # .values on older versions
array([1])

or if there is only one and you want the integer, you can subset

>>> df[df['LastName'] == 'Smith'].index[0]
1

You could use the same boolean expressions with .loc, but it is not needed unless you also want to select a certain column, which is redundant when you only want the row number/index.

Button background as transparent

Selectors work only for drawables, not styles. Reference


First, to make the button background transparent use the following attribute as this will not affect the material design animations:

style="?attr/buttonBarButtonStyle"

There are many ways to style your button. Check out this tutorial.

Second, to make the text bold on pressed, use this java code:

btn.setOnTouchListener(new View.OnTouchListener() {
    @Override
    public boolean onTouch(View v, MotionEvent event) {

        switch (event.getAction()) {
            // When the user clicks the Button
            case MotionEvent.ACTION_DOWN:
                btn.setTypeface(Typeface.DEFAULT_BOLD);
                break;

            // When the user releases the Button
            case MotionEvent.ACTION_UP:
                btn.setTypeface(Typeface.DEFAULT);
                break;
        }
        return false;
    }
});

PHP date add 5 year to current date

Use this code to add years or months or days or hours or minutes or seconds to a given date

 echo date("Y-m-d H:i:s", strtotime("+1 years", strtotime('2014-05-22 10:35:10'))); //2015-05-22 10:35:10
 echo date("Y-m-d H:i:s", strtotime("+1 months", strtotime('2014-05-22 10:35:10')));//2014-06-22 10:35:10
 echo date("Y-m-d H:i:s", strtotime("+1 days", strtotime('2014-05-22 10:35:10')));//2014-05-23 10:35:10
 echo date("Y-m-d H:i:s", strtotime("+1 hours", strtotime('2014-05-22 10:35:10')));//2014-05-22 11:35:10
 echo date("Y-m-d H:i:s", strtotime("+1 minutes", strtotime('2014-05-22 10:35:10')));//2014-05-22 10:36:10
 echo date("Y-m-d H:i:s", strtotime("+1 seconds", strtotime('2014-05-22 10:35:10')));//2014-05-22 10:35:11

You can also subtract replacing + to -

Update multiple columns in SQL

Syntax

UPDATE table-name 
SET column-name = value, column-name = value, ...
WHERE condition

Example

UPDATE school
SET course = 'mysqli', teacher = 'Tanzania', student = 'you'
WHERE id = 6

git - pulling from specific branch

You can take update / pull on git branch you can use below command

git pull origin <branch-name>

The above command will take an update/pull from giving branch name

If you want to take pull from another branch, you need to go to that branch.

git checkout master

Than

git pull origin development

Hope that will work for you

CardView not showing Shadow in Android L

You can add this line of code for shadow in card view

card_view:cardElevation="3dp"

Below you have an example

<android.support.v7.widget.CardView
    xmlns:card_view="http://schemas.android.com/apk/res-auto"
    android:id="@+id/card_view"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    app:cardBackgroundColor="@android:color/white"
    android:foreground="?android:attr/selectableItemBackground"
    card_view:cardElevation="3dp"
    card_view:cardCornerRadius="4dp">

Hope this helps!

Find all packages installed with easy_install/pip?

If Debian behaves like recent Ubuntu versions regarding pip install default target, it's dead easy: it installs to /usr/local/lib/ instead of /usr/lib (apt default target). Check https://askubuntu.com/questions/173323/how-do-i-detect-and-remove-python-packages-installed-via-pip/259747#259747

I am an ArchLinux user and as I experimented with pip I met this same problem. Here's how I solved it in Arch.

find /usr/lib/python2.7/site-packages -maxdepth 2 -name __init__.py | xargs pacman -Qo | grep 'No package'

Key here is /usr/lib/python2.7/site-packages, which is the directory pip installs to, YMMV. pacman -Qo is how Arch's pac kage man ager checks for ownership of the file. No package is part of the return it gives when no package owns the file: error: No package owns $FILENAME. Tricky workaround: I'm querying about __init__.py because pacman -Qo is a little bit ignorant when it comes to directories :(

In order to do it for other distros, you have to find out where pip installs stuff (just sudo pip install something), how to query ownership of a file (Debian/Ubuntu method is dpkg -S) and what is the "no package owns that path" return (Debian/Ubuntu is no path found matching pattern). Debian/Ubuntu users, beware: dpkg -S will fail if you give it a symbolic link. Just resolve it first by using realpath. Like this:

find /usr/local/lib/python2.7/dist-packages -maxdepth 2 -name __init__.py | xargs realpath | xargs dpkg -S 2>&1 | grep 'no path found'

Fedora users can try (thanks @eddygeek):

find /usr/lib/python2.7/site-packages -maxdepth 2 -name __init__.py | xargs rpm -qf | grep 'not owned by any package'

How to change option menu icon in the action bar?

An short and easy way to change color of option menu index icon is:

<!-- android:textColorSecondary is the color of the menu overflow icon (three vertical dots) -->
<item name="android:textColorSecondary">@color/optionMenuIconColor</item>

Add above line of code into style.xml (custom theme) file, Hope you get answer,Thanks.

System.Drawing.Image to stream C#

public static Stream ToStream(this Image image)
{
     var stream = new MemoryStream();

     image.Save(stream, image.RawFormat);
     stream.Position = 0;

     return stream;
 }

Position one element relative to another in CSS

position: absolute will position the element by coordinates, relative to the closest positioned ancestor, i.e. the closest parent which isn't position: static.

Have your four divs nested inside the target div, give the target div position: relative, and use position: absolute on the others.

Structure your HTML similar to this:

<div id="container">
  <div class="top left"></div>
  <div class="top right"></div>
  <div class="bottom left"></div>
  <div class="bottom right"></div>
</div>

And this CSS should work:

#container {
  position: relative;
}

#container > * {
  position: absolute;
}

.left {
  left: 0;
}

.right {
  right: 0;
}

.top {
  top: 0;
}

.bottom {
  bottom: 0;
}

...

Python: importing a sub-package or sub-module

The reason #2 fails is because sys.modules['module'] does not exist (the import routine has its own scope, and cannot see the module local name), and there's no module module or package on-disk. Note that you can separate multiple imported names by commas.

from package.subpackage.module import attribute1, attribute2, attribute3

Also:

from package.subpackage import module
print module.attribute1

Use Font Awesome Icon in Placeholder

I added both text and icon together in a placeholder.

placeholder="Edit &nbsp; &#xf040;"

CSS :

font-family: FontAwesome,'Merriweather Sans', sans-serif;

Two onClick actions one button

<input type="button" value="..." onClick="fbLikeDump(); WriteCookie();" />

Error in installation a R package

There could be a few things happening here. Start by first figuring out your library location:

Sys.getenv("R_LIBS_USER")

or

.libPaths()

We already know yours from the info you gave: C:\Program Files\R\R-3.0.1\library

I believe you have a file in there called: 00LOCK. From ?install.packages:

Note that it is possible for the package installation to fail so badly that the lock directory is not removed: this inhibits any further installs to the library directory (or for --pkglock, of the package) until the lock directory is removed manually.

You need to delete that file. If you had the pacman package installed you could have simply used p_unlock() and the 00LOCK file is removed. You can't install pacman now until the 00LOCK file is removed.

To install pacman use:

install.packages("pacman")

There may be a second issue. This is where you somehow corrupted MASS. This can occur, in my experience, if you try to update a package while it is in use in another R session. I'm sure there's other ways to cause this as well. To solve this problem try:

  1. Close out of all R sessions (use task manager to ensure you're truly R session free) Ctrl + Alt + Delete
  2. Go to your library location Sys.getenv("R_LIBS_USER"). In your case this is: C:\Program Files\R\R-3.0.1\library
  3. Manually delete the MASS package
  4. Fire up a vanilla session of R
  5. Install MASS via install.packages("MASS")

If any of this works please let me know what worked.

Is it possible to create a remote repo on GitHub from the CLI without opening browser?

You can create a GitHub repo via the command line using the GitHub API. Check out the repository API. If you scroll down about a third of the way, you'll see a section entitled "Create" that explains how to create a repo via the API (right above that is a section that explains how to fork a repo with the API, too). Obviously you can't use git to do this, but you can do it via the command line with a tool like curl.

Outside of the API, there's no way to create a repo on GitHub via the command line. As you noted, GitHub doesn't allow shell access, etc., so aside from the GitHub API, the only way to create a repo is through GitHub's web interface.

Android Notification Sound

You can make a function:

public void playNotificationSound() 
{
    try
    {

        Uri alarmSound = `Uri.parse(ContentResolver.SCHEME_ANDROID_RESOURCE + "://" + MyApplication.getInstance().getApplicationContext().getPackageName() + "/raw/notification");`
        Ringtone r = RingtoneManager.getRingtone(MyApplication.getInstance().getApplicationContext(), alarmSound);
        r.play();
    }
    catch (Exception e) 
    {
        e.printStackTrace();
    }
}

Call this function when you receive notification.

Here raw is the folder in res and the notification is the sound file in raw folder.

JavaScript/JQuery: $(window).resize how to fire AFTER the resize is completed?

Assuming that the mouse cursor should return to the document after window resize, we can create a callback-like behavior with onmouseover event. Don't forget that this solution may not work for touch-enabled screens as expected.

var resizeTimer;
var resized = false;
$(window).resize(function() {
   clearTimeout(resizeTimer);
   resizeTimer = setTimeout(function() {
       if(!resized) {
           resized = true;
           $(document).mouseover(function() {
               resized = false;
               // do something here
               $(this).unbind("mouseover");
           })
       }
    }, 500);
});

Find an item in List by LINQ?

This method is easier and safer

var lOrders = new List<string>();

bool insertOrderNew = lOrders.Find(r => r == "1234") == null ? true : false

How to disable Paste (Ctrl+V) with jQuery?

Edit: It's almost 6 years later, looking at this now I wouldn't recommend this solution. The accepted answer is definitely much better. Go with that!


This seems to work.

You can listen to keyboard events with jQuery and prevent the event from completing if its the key combo you are looking for. Note, check 118 and 86 (V and v)

Working example here: http://jsfiddle.net/dannylane/9pRsx/4/

$(document).ready(function(){
    $(document).keydown(function(event) {
        if (event.ctrlKey==true && (event.which == '118' || event.which == '86')) {
            alert('thou. shalt. not. PASTE!');
            event.preventDefault();
         }
    });
});

Update: keypress doesn't fire in IE, use keydown instead.

There is no ViewData item of type 'IEnumerable<SelectListItem>' that has the key 'xxx'

The problem is because of post back happens on submit button click. So while posting data on submit click again write before returning View()

ViewData["Submarkets"] = new SelectList(submarketRep.AllOrdered(), "id", "name");

Breaking a list into multiple columns in Latex

Using the multicol package and embedding your list in a multicols environment does what you want:

\documentclass{article}
\usepackage{multicol}

\begin{document}
\begin{multicols}{2}
\begin{enumerate}
    \item a
    \item b
    \item c
    \item d
    \item e
    \item f
\end{enumerate}
\end{multicols}
\end{document}

Can I serve multiple clients using just Flask app.run() as standalone?

flask.Flask.run accepts additional keyword arguments (**options) that it forwards to werkzeug.serving.run_simple - two of those arguments are threaded (a boolean) and processes (which you can set to a number greater than one to have werkzeug spawn more than one process to handle requests).

threaded defaults to True as of Flask 1.0, so for the latest versions of Flask, the default development server will be able to serve multiple clients simultaneously by default. For older versions of Flask, you can explicitly pass threaded=True to enable this behaviour.

For example, you can do

if __name__ == '__main__':
    app.run(threaded=True)

to handle multiple clients using threads in a way compatible with old Flask versions, or

if __name__ == '__main__':
    app.run(threaded=False, processes=3)

to tell Werkzeug to spawn three processes to handle incoming requests, or just

if __name__ == '__main__':
    app.run()

to handle multiple clients using threads if you know that you will be using Flask 1.0 or later.

That being said, Werkzeug's serving.run_simple wraps the standard library's wsgiref package - and that package contains a reference implementation of WSGI, not a production-ready web server. If you are going to use Flask in production (assuming that "production" is not a low-traffic internal application with no more than 10 concurrent users) make sure to stand it up behind a real web server (see the section of Flask's docs entitled Deployment Options for some suggested methods).

Best way to find os name and version in Unix/Linux platform

In every distribute it has difference files so I write most common ones:

---- CentOS Linux distro
`cat /proc/version`
---- Debian Linux distro
`cat /etc/debian_version`
---- Redhat Linux distro
`cat /etc/redhat-release` 
---- Ubuntu Linux distro
`cat /etc/issue`   or   `cat /etc/lsb-release`

in last one /etc/issue didn't exist so I tried the second one and it returned the right answer

EC2 instance has no public DNS

After verifying VPC and Subnet settings, my EC2 instance still didn't have a public DNS. After a day of searching for a resolution, I finally figured it out.

I had to create a new Elastic IP address, then associate it to my instance.

From the EC2 Dashboard:

Go to Elastic IPs from the sidebar.

Click Allocate new address, then Allocate.

Go back to the EC2 Dashboard. Go to Network Interfaces.

Select the EC2 instance without a public DNS. Then Actions - Associate Address.

The Address field, select the new elastic IP address.

The Associate to private IP address field, select the private IP address with no public DNS.

Click Associate Address.

Your EC2 instance should now have a public DNS.

How to window.scrollTo() with a smooth effect

$('html, body').animate({scrollTop:1200},'50');

You can do this!

How many times a substring occurs

s = input('enter the main string: ')
p=input('enter the substring: ')
l=[]
for i in range(len(s)):
    l.append(s[i:i+len(p)])
print(l.count(p))

How to add header row to a pandas DataFrame

Alternatively you could read you csv with header=None and then add it with df.columns:

Cov = pd.read_csv("path/to/file.txt", sep='\t', header=None)
Cov.columns = ["Sequence", "Start", "End", "Coverage"]

Can I dynamically add HTML within a div tag from C# on load event?

You could reference controls inside the master page this way:

void Page_Load()
{
    ContentPlaceHolder cph;
    Literal lit;

    cph = (ContentPlaceHolder)Master.FindControl("ContentPlaceHolder1");

    if (cph != null) {
        lit = (Literal) cph.FindControl("Literal1");
        if (lit != null) {
            lit.Text = "Some <b>HTML</b>";
        }
    }

}

In this example you have to put a Literal control in your ContentPlaceholder.

Object Library Not Registered When Adding Windows Common Controls 6.0

You can run the tool from Microsoft in this KB http://support.microsoft.com/default.aspx?scid=kb;en-us;Q195353 to fix the licensing issues for earlier ActiveX controls. This worked for me.

How to load a jar file at runtime

I googled a bit, and found this code here:

File file = getJarFileToLoadFrom();   
String lcStr = getNameOfClassToLoad();   
URL jarfile = new URL("jar", "","file:" + file.getAbsolutePath()+"!/");    
URLClassLoader cl = URLClassLoader.newInstance(new URL[] {jarfile });   
Class loadedClass = cl.loadClass(lcStr);   

Can anyone share opinions/comments/answers regarding this approach?

Angular 2 - NgFor using numbers instead collections

My solution:

export class DashboardManagementComponent implements OnInit {
  _cols = 5;
  _rows = 10;
  constructor() { }

  ngOnInit() {
  }

  get cols() {
    return Array(this._cols).fill(null).map((el, index) => index);
  }
  get rows() {
    return Array(this._rows).fill(null).map((el, index) => index);
  }

In html:

<div class="charts-setup">
  <div class="col" *ngFor="let col of cols; let colIdx = index">
    <div class="row" *ngFor="let row of rows; let rowIdx = index">
      Col: {{colIdx}}, row: {{rowIdx}}
    </div>
  </div>
</div>

How to Use -confirm in PowerShell

Read-Host is one example of a cmdlet that -Confirm does not have an effect on.-Confirm is one of PowerShell's Common Parameters specifically a Risk-Mitigation Parameter which is used when a cmdlet is about to make a change to the system that is outside of the Windows PowerShell environment. Many but not all cmdlets support the -Confirm risk mitigation parameter.

As an alternative the following would be an example of using the Read-Host cmdlet and a regular expression test to get confirmation from a user:

$reply = Read-Host -Prompt "Continue?[y/n]"
if ( $reply -match "[yY]" ) { 
    # Highway to the danger zone 
}

The Remove-Variable cmdlet is one example that illustrates the usage of the -confirm switch.

Remove-Variable 'reply' -Confirm

Additional References: CommonParameters, Write-Host, Read-Host, Comparison Operators, Regular Expressions, Remove-Variable

How to calculate the number of days between two dates?

From my little date difference calculator:

var startDate = new Date(2000, 1-1, 1);  // 2000-01-01
var endDate =   new Date();              // Today

// Calculate the difference of two dates in total days
function diffDays(d1, d2)
{
  var ndays;
  var tv1 = d1.valueOf();  // msec since 1970
  var tv2 = d2.valueOf();

  ndays = (tv2 - tv1) / 1000 / 86400;
  ndays = Math.round(ndays - 0.5);
  return ndays;
}

So you would call:

var nDays = diffDays(startDate, endDate);

(Full source at http://david.tribble.com/src/javascript/jstimespan.html.)

Addendum

The code can be improved by changing these lines:

  var tv1 = d1.getTime();  // msec since 1970
  var tv2 = d2.getTime();

How to upload file to server with HTTP POST multipart/form-data?

Top to @loop answer.

We got below error for Asp.Net MVC, Unable to connect to the remote server

Fix: After adding the below code in Web.Confing issue has been resolved for us

  <system.net>
    <defaultProxy useDefaultCredentials="true" >
    </defaultProxy>
  </system.net>

Maximum value of maxRequestLength?

Maximum is 2097151, If you try set more error occurred.

Messagebox with input field

You can reference Microsoft.VisualBasic.dll.

Then using the code below.

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

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

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

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

how to console.log result of this ajax call?

In Chrome, right click in the console and check 'preserve log on navigation'.

Using Java to pull data from a webpage?

The simplest solution (without depending on any third-party library or platform) is to create a URL instance pointing to the web page / link you want to download, and read the content using streams.

For example:

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.URL;
import java.net.URLConnection;


public class DownloadPage {

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

        // Make a URL to the web page
        URL url = new URL("http://stackoverflow.com/questions/6159118/using-java-to-pull-data-from-a-webpage");

        // Get the input stream through URL Connection
        URLConnection con = url.openConnection();
        InputStream is =con.getInputStream();

        // Once you have the Input Stream, it's just plain old Java IO stuff.

        // For this case, since you are interested in getting plain-text web page
        // I'll use a reader and output the text content to System.out.

        // For binary content, it's better to directly read the bytes from stream and write
        // to the target file.


        BufferedReader br = new BufferedReader(new InputStreamReader(is));

        String line = null;

        // read each line and write to System.out
        while ((line = br.readLine()) != null) {
            System.out.println(line);
        }
    }
}

Hope this helps.

INSTALL_FAILED_NO_MATCHING_ABIS when install apk

I know there were lots of answers here, but the TL;DR version is this (If you're using Xamarin Studio):

  1. Right click the Android project in the solution tree
  2. Select Options
  3. Go to Android Build
  4. Go to Advanced tab
  5. Check the architectures you use in your emulator (Probably x86 / armeabi-v7a / armeabi)
  6. Make a kickass app :)

When is it acceptable to call GC.Collect?

Scott Holden's blog entry on when to (and when not to) call GC.Collect is specific to the .NET Compact Framework, but the rules generally apply to all managed development.

Converting String to Int with Swift

Question : string "4.0000" can not be convert into integer using Int("4.000")?

Answer : Int() check string is integer or not if yes then give you integer and otherwise nil. but Float or Double can convert any number string to respective Float or Double without giving nil. Example if you have "45" integer string but using Float("45") gives you 45.0 float value or using Double("4567") gives you 45.0.

Solution : NSString(string: "45.000").integerValue or Int(Float("45.000")!)! to get correct result.

How can I pass variable to ansible playbook in the command line?

ansible-playbook release.yml --extra-vars "username=hello password=bye"

#you can now use the above command anywhere in the playbook as an example below:
tasks:
- name: Create a new user in Linux
shell: useradd -m -p {{username}} {{password}}"

Lua - Current time in milliseconds

If you're using lua with nginx/openresty you could use ngx.now() which returns a float with millisecond precision

Cannot connect to Database server (mysql workbench)

I struggled with this problem for awhile and did several reinstalls of MySQL before discovering this.

I know that MySQL server was running OK because I could access all my DB's using the command line.

Hope this works for you.

In MySQL Workbench (5.2.47 CE)

click Mange Server Instances (bottom right corner)

click Connection

in the Connection box select:

Local Instance ($ServerName) - [email protected]:3306 '<'Standard(TCP/IP)>

click Edit Selected...

under Parameters, Hostname change localhost or 127.0.0.1 to your NetBIOS name

click Test Connection

If this works for you, great. If not change the hostname back to what it was.

SQL Network Interfaces, error: 26 - Error Locating Server/Instance Specified

Same issue. In my case I solved setting the project as the "StartUp Project".

Switch statement for greater-than/less-than

Updating the accepted answer (can't comment yet). As of 1/12/16 using the demo jsfiddle in chrome, switch-immediate is the fastest solution.

Results: Time resolution: 1.33

   25ms "if-immediate" 150878146 
   29ms "if-indirect" 150878146
   24ms "switch-immediate" 150878146
   128ms "switch-range" 150878146
   45ms "switch-range2" 150878146
   47ms "switch-indirect-array" 150878146
   43ms "array-linear-switch" 150878146
   72ms "array-binary-switch" 150878146

Finished

 1.04 (   25ms) if-immediate
 1.21 (   29ms) if-indirect
 1.00 (   24ms) switch-immediate
 5.33 (  128ms) switch-range
 1.88 (   45ms) switch-range2
 1.96 (   47ms) switch-indirect-array
 1.79 (   43ms) array-linear-switch
 3.00 (   72ms) array-binary-switch

UNIX export command

export is used to set environment variables. For example:

export EDITOR=pico

Will set your default text editor to be the pico command.

Distinct by property of class with LINQ

I think the best option in Terms of performance (or in any terms) is to Distinct using the The IEqualityComparer interface.

Although implementing each time a new comparer for each class is cumbersome and produces boilerplate code.

So here is an extension method which produces a new IEqualityComparer on the fly for any class using reflection.

Usage:

var filtered = taskList.DistinctBy(t => t.TaskExternalId).ToArray();

Extension Method Code

public static class LinqExtensions
{
    public static IEnumerable<T> DistinctBy<T, TKey>(this IEnumerable<T> items, Func<T, TKey> property)
    {
        GeneralPropertyComparer<T, TKey> comparer = new GeneralPropertyComparer<T,TKey>(property);
        return items.Distinct(comparer);
    }   
}
public class GeneralPropertyComparer<T,TKey> : IEqualityComparer<T>
{
    private Func<T, TKey> expr { get; set; }
    public GeneralPropertyComparer (Func<T, TKey> expr)
    {
        this.expr = expr;
    }
    public bool Equals(T left, T right)
    {
        var leftProp = expr.Invoke(left);
        var rightProp = expr.Invoke(right);
        if (leftProp == null && rightProp == null)
            return true;
        else if (leftProp == null ^ rightProp == null)
            return false;
        else
            return leftProp.Equals(rightProp);
    }
    public int GetHashCode(T obj)
    {
        var prop = expr.Invoke(obj);
        return (prop==null)? 0:prop.GetHashCode();
    }
}

What exactly does the "u" do? "git push -u origin master" vs "git push origin master"

All necessary git bash commands to push and pull into Github:

git status 
git pull
git add filefullpath

git commit -m "comments for checkin file" 
git push origin branch/master
git remote -v 
git log -2 

If you want to edit a file then:

edit filename.* 

To see all branches and their commits:

git show-branch

How to get current foreground activity context in android?

I did the Following in Kotlin

  1. Create Application Class
  2. Edit the Application Class as Follows

    class FTApplication: MultiDexApplication() {
    override fun attachBaseContext(base: Context?) {
        super.attachBaseContext(base)
        MultiDex.install(this)
    }
    
    init {
        instance = this
    }
    
    val mFTActivityLifecycleCallbacks = FTActivityLifecycleCallbacks()
    
    override fun onCreate() {
        super.onCreate()
    
        registerActivityLifecycleCallbacks(mFTActivityLifecycleCallbacks)
    }
    
    companion object {
        private var instance: FTApplication? = null
    
        fun currentActivity(): Activity? {
    
            return instance!!.mFTActivityLifecycleCallbacks.currentActivity
        }
    }
    
     }
    
  3. Create the ActivityLifecycleCallbacks class

    class FTActivityLifecycleCallbacks: Application.ActivityLifecycleCallbacks {
    
    var currentActivity: Activity? = null
    
    override fun onActivityPaused(activity: Activity?) {
        currentActivity = activity
    }
    
    override fun onActivityResumed(activity: Activity?) {
        currentActivity = activity
    }
    
    override fun onActivityStarted(activity: Activity?) {
        currentActivity = activity
    }
    
    override fun onActivityDestroyed(activity: Activity?) {
    }
    
    override fun onActivitySaveInstanceState(activity: Activity?, outState: Bundle?) {
    }
    
    override fun onActivityStopped(activity: Activity?) {
    }
    
    override fun onActivityCreated(activity: Activity?, savedInstanceState: Bundle?) {
        currentActivity = activity
    }
    
    }
    
  4. you can now use it in any class by calling the following: FTApplication.currentActivity()

curl POST format for CURLOPT_POSTFIELDS

In case you are sending a string, urlencode() it. Otherwise if array, it should be key=>value paired and the Content-type header is automatically set to multipart/form-data.

Also, you don't have to create extra functions to build the query for your arrays, you already have that:

$query = http_build_query($data, '', '&');

sqlite database default time value 'now'

It is syntax error because you did not write parenthesis

if you write

Select datetime('now') then it will give you utc time but if you this write it query then you must add parenthesis before this so (datetime('now')) for UTC Time. for local time same Select datetime('now','localtime') for query

(datetime('now','localtime'))

How to get the name of the current method from code

using System.Diagnostics;
...

var st = new StackTrace();
var sf = st.GetFrame(0);

var currentMethodName = sf.GetMethod();

Or, if you'd like to have a helper method:

[MethodImpl(MethodImplOptions.NoInlining)]
public string GetCurrentMethod()
{
    var st = new StackTrace();
    var sf = st.GetFrame(1);

    return sf.GetMethod().Name;
}

Updated with credits to @stusmith.

How to use XMLReader in PHP?

Simple example:

public function productsAction()
{
    $saveFileName = 'ceneo.xml';
    $filename = $this->path . $saveFileName;
    if(file_exists($filename)) {

    $reader = new XMLReader();
    $reader->open($filename);

    $countElements = 0;

    while($reader->read()) {
        if($reader->nodeType == XMLReader::ELEMENT) {
            $nodeName = $reader->name;
        }

        if($reader->nodeType == XMLReader::TEXT && !empty($nodeName)) {
            switch ($nodeName) {
                case 'id':
                    var_dump($reader->value);
                    break;
            }
        }

        if($reader->nodeType == XMLReader::END_ELEMENT && $reader->name == 'offer') {
            $countElements++;
        }
    }
    $reader->close();
    exit(print('<pre>') . var_dump($countElements));
    }
}

What is the difference between ports 465 and 587?

SMTP protocol: smtps (port 465) v. msa (port 587)

Ports 465 and 587 are intended for email client to email server communication - sending out email using SMTP protocol.

Port 465 is for smtps
SSL encryption is started automatically before any SMTP level communication.

Port 587 is for msa
It is almost like standard SMTP port. MSA should accept email after authentication (e.g. after SMTP AUTH). It helps to stop outgoing spam when netmasters of DUL ranges can block outgoing connections to SMTP port (port 25).
SSL encryption may be started by STARTTLS command at SMTP level if server supports it and your ISP does not filter server's EHLO reply (reported 2014).


Port 25 is used by MTA to MTA communication (mail server to mail server). It may be used for client to server communication but it is not currently the most recommended. Standard SMTP port accepts email from other mail servers to its "internal" mailboxes without authentication.

Labels for radio buttons in rails form

If you want the object_name prefixed to any ID you should call form helpers on the form object:

- form_for(@message) do |f|
  = f.label :email

This also makes sure any submitted data is stored in memory should there be any validation errors etc.

If you can't call the form helper method on the form object, for example if you're using a tag helper (radio_button_tag etc.) you can interpolate the name using:

= radio_button_tag "#{f.object_name}[email]", @message.email

In this case you'd need to specify the value manually to preserve any submissions.

ValueError: invalid literal for int () with base 10

I recently came across a case where none of these answers worked. I encountered CSV data where there were null bytes mixed in with the data, and those null bytes did not get stripped. So, my numeric string, after stripping, consisted of bytes like this:

\x00\x31\x00\x0d\x00

To counter this, I did:

countStr = fields[3].replace('\x00', '').strip()
count = int(countStr)

...where fields is a list of csv values resulting from splitting the line.

How to remove a class from elements in pure JavaScript?

Given worked for me.

document.querySelectorAll(".widget.hover").forEach(obj=>obj.classList.remove("hover"));

Center image in table td in CSS

As per my analysis and search on the internet also, I could not found a way to centre the image vertically centred using <div> it was possible only using <table> because table provides the following property:

valign="middle"

How do I remove accents from characters in a PHP string?

if you have http://php.net/manual/en/book.intl.php available, this solved your problem

$string = "Fóø Bår";
$transliterator = Transliterator::createFromRules(':: Any-Latin; :: Latin-ASCII; :: NFD; :: [:Nonspacing Mark:] Remove; :: Lower(); :: NFC;', Transliterator::FORWARD);
echo $normalized = $transliterator->transliterate($string);

Is it possible to ignore one single specific line with Pylint?

Checkout the files in https://github.com/PyCQA/pylint/tree/master/pylint/checkers. I haven't found a better way to obtain the error name from a message than either Ctrl + F-ing those files or using the GitHub search feature:

If the message is "No name ... in module ...", use the search:

No name %r in module %r repo:PyCQA/pylint/tree/master path:/pylint/checkers

Or, to get fewer results:

"No name %r in module %r" repo:PyCQA/pylint/tree/master path:/pylint/checkers

GitHub will show you:

"E0611": (
    "No name %r in module %r",
    "no-name-in-module",
    "Used when a name cannot be found in a module.",

You can then do:

from collections import Sequence # pylint: disable=no-name-in-module

SQL Row_Number() function in Where Clause

based on OP's answer to question:

Please see this link. Its having a different solution, which looks working for the person who asked the question. I'm trying to figure out a solution like this.

Paginated query using sorting on different columns using ROW_NUMBER() OVER () in SQL Server 2005

~Joseph

"method 1" is like the OP's query from the linked question, and "method 2" is like the query from the selected answer. You had to look at the code linked in this answer to see what was really going on, since the code in the selected answer was modified to make it work. Try this:

DECLARE @YourTable table (RowID int not null primary key identity, Value1 int, Value2 int, value3 int)
SET NOCOUNT ON
INSERT INTO @YourTable VALUES (1,1,1)
INSERT INTO @YourTable VALUES (1,1,2)
INSERT INTO @YourTable VALUES (1,1,3)
INSERT INTO @YourTable VALUES (1,2,1)
INSERT INTO @YourTable VALUES (1,2,2)
INSERT INTO @YourTable VALUES (1,2,3)
INSERT INTO @YourTable VALUES (1,3,1)
INSERT INTO @YourTable VALUES (1,3,2)
INSERT INTO @YourTable VALUES (1,3,3)
INSERT INTO @YourTable VALUES (2,1,1)
INSERT INTO @YourTable VALUES (2,1,2)
INSERT INTO @YourTable VALUES (2,1,3)
INSERT INTO @YourTable VALUES (2,2,1)
INSERT INTO @YourTable VALUES (2,2,2)
INSERT INTO @YourTable VALUES (2,2,3)
INSERT INTO @YourTable VALUES (2,3,1)
INSERT INTO @YourTable VALUES (2,3,2)
INSERT INTO @YourTable VALUES (2,3,3)
INSERT INTO @YourTable VALUES (3,1,1)
INSERT INTO @YourTable VALUES (3,1,2)
INSERT INTO @YourTable VALUES (3,1,3)
INSERT INTO @YourTable VALUES (3,2,1)
INSERT INTO @YourTable VALUES (3,2,2)
INSERT INTO @YourTable VALUES (3,2,3)
INSERT INTO @YourTable VALUES (3,3,1)
INSERT INTO @YourTable VALUES (3,3,2)
INSERT INTO @YourTable VALUES (3,3,3)
SET NOCOUNT OFF

DECLARE @PageNumber     int
DECLARE @PageSize       int
DECLARE @SortBy         int

SET @PageNumber=3
SET @PageSize=5
SET @SortBy=1


--SELECT * FROM @YourTable

--Method 1
;WITH PaginatedYourTable AS (
SELECT
    RowID,Value1,Value2,Value3
        ,CASE @SortBy
             WHEN  1 THEN ROW_NUMBER() OVER (ORDER BY Value1 ASC)
             WHEN  2 THEN ROW_NUMBER() OVER (ORDER BY Value2 ASC)
             WHEN  3 THEN ROW_NUMBER() OVER (ORDER BY Value3 ASC)
             WHEN -1 THEN ROW_NUMBER() OVER (ORDER BY Value1 DESC)
             WHEN -2 THEN ROW_NUMBER() OVER (ORDER BY Value2 DESC)
             WHEN -3 THEN ROW_NUMBER() OVER (ORDER BY Value3 DESC)
         END AS RowNumber
    FROM @YourTable
    --WHERE
)
SELECT
    RowID,Value1,Value2,Value3,RowNumber
        ,@PageNumber AS PageNumber, @PageSize AS PageSize, @SortBy AS SortBy
    FROM PaginatedYourTable
    WHERE RowNumber>=(@PageNumber-1)*@PageSize AND RowNumber<=(@PageNumber*@PageSize)-1
    ORDER BY RowNumber



--------------------------------------------
--Method 2
;WITH PaginatedYourTable AS (
SELECT
    RowID,Value1,Value2,Value3
        ,ROW_NUMBER() OVER
         (
             ORDER BY
                 CASE @SortBy
                     WHEN  1 THEN Value1
                     WHEN  2 THEN Value2
                     WHEN  3 THEN Value3
                 END ASC
                ,CASE @SortBy
                     WHEN -1 THEN Value1
                     WHEN -2 THEN Value2
                     WHEN -3 THEN Value3
                 END DESC
         ) RowNumber
    FROM @YourTable
    --WHERE  more conditions here
)
SELECT
    RowID,Value1,Value2,Value3,RowNumber
        ,@PageNumber AS PageNumber, @PageSize AS PageSize, @SortBy AS SortBy
    FROM PaginatedYourTable
    WHERE 
        RowNumber>=(@PageNumber-1)*@PageSize AND RowNumber<=(@PageNumber*@PageSize)-1
        --AND more conditions here
    ORDER BY
        CASE @SortBy
            WHEN  1 THEN Value1
            WHEN  2 THEN Value2
            WHEN  3 THEN Value3
        END ASC
       ,CASE @SortBy
            WHEN -1 THEN Value1
            WHEN -2 THEN Value2
            WHEN -3 THEN Value3
        END DESC

OUTPUT:

RowID  Value1 Value2 Value3 RowNumber  PageNumber  PageSize    SortBy
------ ------ ------ ------ ---------- ----------- ----------- -----------
10     2      1      1      10         3           5           1
11     2      1      2      11         3           5           1
12     2      1      3      12         3           5           1
13     2      2      1      13         3           5           1
14     2      2      2      14         3           5           1

(5 row(s) affected

RowID  Value1 Value2 Value3 RowNumber  PageNumber  PageSize    SortBy
------ ------ ------ ------ ---------- ----------- ----------- -----------
10     2      1      1      10         3           5           1
11     2      1      2      11         3           5           1
12     2      1      3      12         3           5           1
13     2      2      1      13         3           5           1
14     2      2      2      14         3           5           1

(5 row(s) affected)

Decoding and verifying JWT token using System.IdentityModel.Tokens.Jwt

I am just wondering why to use some libraries for JWT token decoding and verification at all.

Encoded JWT token can be created using following pseudocode

var headers = base64URLencode(myHeaders);
var claims = base64URLencode(myClaims);
var payload = header + "." + claims;

var signature = base64URLencode(HMACSHA256(payload, secret));

var encodedJWT = payload + "." + signature;

It is very easy to do without any specific library. Using following code:

using System;
using System.Text;
using System.Security.Cryptography;

public class Program
{   
    // More info: https://stormpath.com/blog/jwt-the-right-way/
    public static void Main()
    {           
        var header = "{\"typ\":\"JWT\",\"alg\":\"HS256\"}";
        var claims = "{\"sub\":\"1047986\",\"email\":\"[email protected]\",\"given_name\":\"John\",\"family_name\":\"Doe\",\"primarysid\":\"b521a2af99bfdc65e04010ac1d046ff5\",\"iss\":\"http://example.com\",\"aud\":\"myapp\",\"exp\":1460555281,\"nbf\":1457963281}";

        var b64header = Convert.ToBase64String(Encoding.UTF8.GetBytes(header))
            .Replace('+', '-')
            .Replace('/', '_')
            .Replace("=", "");
        var b64claims = Convert.ToBase64String(Encoding.UTF8.GetBytes(claims))
            .Replace('+', '-')
            .Replace('/', '_')
            .Replace("=", "");

        var payload = b64header + "." + b64claims;
        Console.WriteLine("JWT without sig:    " + payload);

        byte[] key = Convert.FromBase64String("mPorwQB8kMDNQeeYO35KOrMMFn6rFVmbIohBphJPnp4=");
        byte[] message = Encoding.UTF8.GetBytes(payload);

        string sig = Convert.ToBase64String(HashHMAC(key, message))
            .Replace('+', '-')
            .Replace('/', '_')
            .Replace("=", "");

        Console.WriteLine("JWT with signature: " + payload + "." + sig);        
    }

    private static byte[] HashHMAC(byte[] key, byte[] message)
    {
        var hash = new HMACSHA256(key);
        return hash.ComputeHash(message);
    }
}

The token decoding is reversed version of the code above.To verify the signature you will need to the same and compare signature part with calculated signature.

UPDATE: For those how are struggling how to do base64 urlsafe encoding/decoding please see another SO question, and also wiki and RFCs

Import SQL file by command line in Windows 7

If you don't have password you can use the command without

-u

Like this

C:\wamp>bin\mysql\mysql5.7.11\bin\mysql.exe -u {User Name} {Database Name} < C:\File.sql

Or on the SQL console

mysql -u {User Name} -p {Database Name} < C:/File.sql

Return None if Dictionary key is not available

You could use a dict object's get() method, as others have already suggested. Alternatively, depending on exactly what you're doing, you might be able use a try/except suite like this:

try:
   <to do something with d[key]>
except KeyError:
   <deal with it not being there>

Which is considered to be a very "Pythonic" approach to handling the case.

PHP - Failed to open stream : No such file or directory

To add to the (really good) existing answer

Shared Hosting Software

open_basedir is one that can stump you because it can be specified in a web server configuration. While this is easily remedied if you run your own dedicated server, there are some shared hosting software packages out there (like Plesk, cPanel, etc) that will configure a configuration directive on a per-domain basis. Because the software builds the configuration file (i.e. httpd.conf) you cannot change that file directly because the hosting software will just overwrite it when it restarts.

With Plesk, they provide a place to override the provided httpd.conf called vhost.conf. Only the server admin can write this file. The configuration for Apache looks something like this

<Directory /var/www/vhosts/domain.com>
    <IfModule mod_php5.c>
        php_admin_flag engine on
        php_admin_flag safe_mode off
        php_admin_value open_basedir "/var/www/vhosts/domain.com:/tmp:/usr/share/pear:/local/PEAR"
    </IfModule>
</Directory>

Have your server admin consult the manual for the hosting and web server software they use.

File Permissions

It's important to note that executing a file through your web server is very different from a command line or cron job execution. The big difference is that your web server has its own user and permissions. For security reasons that user is pretty restricted. Apache, for instance, is often apache, www-data or httpd (depending on your server). A cron job or CLI execution has whatever permissions that the user running it has (i.e. running a PHP script as root will execute with permissions of root).

A lot of times people will solve a permissions problem by doing the following (Linux example)

chmod 777 /path/to/file

This is not a smart idea, because the file or directory is now world writable. If you own the server and are the only user then this isn't such a big deal, but if you're on a shared hosting environment you've just given everyone on your server access.

What you need to do is determine the user(s) that need access and give only those them access. Once you know which users need access you'll want to make sure that

  1. That user owns the file and possibly the parent directory (especially the parent directory if you want to write files). In most shared hosting environments this won't be an issue, because your user should own all the files underneath your root. A Linux example is shown below

     chown apache:apache /path/to/file
    
  2. The user, and only that user, has access. In Linux, a good practice would be chmod 600 (only owner can read and write) or chmod 644 (owner can write but everyone can read)

You can read a more extended discussion of Linux/Unix permissions and users here

C++ Error 'nullptr was not declared in this scope' in Eclipse IDE

Go to Settings -> Compiler... And add flag to "Have g++ follow the coming C++0x ISO C++ language standard [std=c++0x]

Angular 2: How to write a for loop, not a foreach loop

You can simply do :-

{{"<li>Something</li>".repeat(5)}}

How to restore the menu bar in Visual Studio Code

If you are like me - you did this by inadvertently hitting F11 - toggling fullscreen mode. https://code.visualstudio.com/shortcuts/keyboard-shortcuts-windows.pdf

Get the short Git version hash

Branch with short hash and last comment:

git branch -v

  develop      717c2f9 [ahead 42] blabla
* master       2722bbe [ahead 1] bla

How do you obtain a Drawable object from a resource id in android package?

As of API 21, you should use the getDrawable(int, Theme) method instead of getDrawable(int), as it allows you to fetch a drawable object associated with a particular resource ID for the given screen density/theme. Calling the deprecated getDrawable(int) method is equivalent to calling getDrawable(int, null).

You should use the following code from the support library instead:

ContextCompat.getDrawable(context, android.R.drawable.ic_dialog_email)

Using this method is equivalent to calling:

if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
    return resources.getDrawable(id, context.getTheme());
} else {
    return resources.getDrawable(id);
}

How to add a TextView to a LinearLayout dynamically in Android?

layout:

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

  <LinearLayout
      android:id="@+id/layoutTest"
      android:layout_width="match_parent"
      android:layout_height="wrap_content"
      android:orientation="vertical"
      >
  </LinearLayout>
</RelativeLayout>

class file:

setContentView(R.layout.layout_dynamic);
layoutTest=(LinearLayout)findViewById(R.id.layoutTest);
TextView textView = new TextView(getApplicationContext());

textView.setText("testDynamic textView");
layoutTest.addView(textView);

How to get memory available or used in C#

System.Environment has WorkingSet- a 64-bit signed integer containing the number of bytes of physical memory mapped to the process context.

If you want a lot of details there is System.Diagnostics.PerformanceCounter, but it will be a bit more effort to setup.

How do I convert strings in a Pandas data frame to a 'date' data type?

Try to convert one of the rows into timestamp using the pd.to_datetime function and then use .map to map the formular to the entire column

Select NOT IN multiple columns

I use a way that may look stupid but it works for me. I simply concat the columns I want to compare and use NOT IN:

SELECT *
FROM table1 t1
WHERE CONCAT(t1.first_name,t1.last_name) NOT IN (SELECT CONCAT(t2.first_name,t2.last_name) FROM table2 t2)

What is the difference between .NET Core and .NET Standard Class Library project types?

.NET Standard: Think of it as a big standard library. When using this as a dependency you can only make libraries (.DLLs), not executables. A library made with .NET standard as a dependency can be added to a Xamarin.Android, a Xamarin.iOS, a .NET Core Windows/OS X/Linux project.

.NET Core: Think of it as the continuation of the old .NET framework, just it's opensource and some stuff is not yet implemented and others got deprecated. It extends the .NET standard with extra functions, but it only runs on desktops. When adding this as a dependency you can make runnable applications on Windows, Linux and OS X. (Although console only for now, no GUIs). So .NET Core = .NET Standard + desktop specific stuff.

Also UWP uses it and the new ASP.NET Core uses it as a dependency too.

Hibernate - Batch update returned unexpected row count from update: 0 actual row count: 0 expected: 1

This happened if you change something in data set using native sql query but persisted object for same data set is present in session cache. Use session.evict(yourObject);

JQuery: if div is visible

You can use .is(':visible')

Selects all elements that are visible.

For example:

if($('#selectDiv').is(':visible')){

Also, you can get the div which is visible by:

$('div:visible').callYourFunction();

Live example:

_x000D_
_x000D_
console.log($('#selectDiv').is(':visible'));_x000D_
console.log($('#visibleDiv').is(':visible'));
_x000D_
#selectDiv {_x000D_
  display: none;  _x000D_
}
_x000D_
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>_x000D_
<div id="selectDiv"></div>_x000D_
<div id="visibleDiv"></div>
_x000D_
_x000D_
_x000D_

How to get detailed list of connections to database in sql server 2005?

There is also who is active?:

Who is Active? is a comprehensive server activity stored procedure based on the SQL Server 2005 and 2008 dynamic management views (DMVs). Think of it as sp_who2 on a hefty dose of anabolic steroids

x86 Assembly on a Mac

Don't forget that unlike Windows, all Unix based system need to have the source before destination unlike Windows

On Windows its:

mov $source , %destination

but on the Mac its the other way around.

Creating an empty Pandas DataFrame, then filling it?

NEVER grow a DataFrame!

TLDR; (just read the bold text)

Most answers here will tell you how to create an empty DataFrame and fill it out, but no one will tell you that it is a bad thing to do.

Here is my advice: Accumulate data in a list, not a DataFrame.

Use a list to collect your data, then initialise a DataFrame when you are ready. Either a list-of-lists or list-of-dicts format will work, pd.DataFrame accepts both.

data = []
for a, b, c in some_function_that_yields_data():
    data.append([a, b, c])

df = pd.DataFrame(data, columns=['A', 'B', 'C'])

Pros of this approach:

  1. It is always cheaper to append to a list and create a DataFrame in one go than it is to create an empty DataFrame (or one of NaNs) and append to it over and over again.

  2. Lists also take up less memory and are a much lighter data structure to work with, append, and remove (if needed).

  3. dtypes are automatically inferred (rather than assigning object to all of them).

  4. A RangeIndex is automatically created for your data, instead of you having to take care to assign the correct index to the row you are appending at each iteration.

If you aren't convinced yet, this is also mentioned in the documentation:

Iteratively appending rows to a DataFrame can be more computationally intensive than a single concatenate. A better solution is to append those rows to a list and then concatenate the list with the original DataFrame all at once.

But what if my function returns smaller DataFrames that I need to combine into one large DataFrame?

That's fine, you can still do this in linear time by growing or creating a python list of smaller DataFrames, then calling pd.concat.

small_dfs = []
for small_df in some_function_that_yields_dataframes():
    small_dfs.append(small_df)

large_df = pd.concat(small_dfs, ignore_index=True)

or, more concisely:

large_df = pd.concat(
    list(some_function_that_yields_dataframes()), ignore_index=True)


These options are horrible

append or concat inside a loop

Here is the biggest mistake I've seen from beginners:

df = pd.DataFrame(columns=['A', 'B', 'C'])
for a, b, c in some_function_that_yields_data():
    df = df.append({'A': i, 'B': b, 'C': c}, ignore_index=True) # yuck
    # or similarly,
    # df = pd.concat([df, pd.Series({'A': i, 'B': b, 'C': c})], ignore_index=True)

Memory is re-allocated for every append or concat operation you have. Couple this with a loop and you have a quadratic complexity operation.

The other mistake associated with df.append is that users tend to forget append is not an in-place function, so the result must be assigned back. You also have to worry about the dtypes:

df = pd.DataFrame(columns=['A', 'B', 'C'])
df = df.append({'A': 1, 'B': 12.3, 'C': 'xyz'}, ignore_index=True)

df.dtypes
A     object   # yuck!
B    float64
C     object
dtype: object

Dealing with object columns is never a good thing, because pandas cannot vectorize operations on those columns. You will need to do this to fix it:

df.infer_objects().dtypes
A      int64
B    float64
C     object
dtype: object

loc inside a loop

I have also seen loc used to append to a DataFrame that was created empty:

df = pd.DataFrame(columns=['A', 'B', 'C'])
for a, b, c in some_function_that_yields_data():
    df.loc[len(df)] = [a, b, c]

As before, you have not pre-allocated the amount of memory you need each time, so the memory is re-grown each time you create a new row. It's just as bad as append, and even more ugly.

Empty DataFrame of NaNs

And then, there's creating a DataFrame of NaNs, and all the caveats associated therewith.

df = pd.DataFrame(columns=['A', 'B', 'C'], index=range(5))
df
     A    B    C
0  NaN  NaN  NaN
1  NaN  NaN  NaN
2  NaN  NaN  NaN
3  NaN  NaN  NaN
4  NaN  NaN  NaN

It creates a DataFrame of object columns, like the others.

df.dtypes
A    object  # you DON'T want this
B    object
C    object
dtype: object

Appending still has all the issues as the methods above.

for i, (a, b, c) in enumerate(some_function_that_yields_data()):
    df.iloc[i] = [a, b, c]


The Proof is in the Pudding

Timing these methods is the fastest way to see just how much they differ in terms of their memory and utility.

enter image description here

Benchmarking code for reference.

Sort an ArrayList based on an object field

You can use the Bean Comparator to sort on any property in your custom class.

HTML: Select multiple as dropdown

Here is the documentation of <select>. You are using 2 attributes:

multiple
This Boolean attribute indicates that multiple options can be selected in the list. If it is not specified, then only one option can be selected at a time. When multiple is specified, most browsers will show a scrolling list box instead of a single line dropdown.

size
If the control is presented as a scrolling list box (e.g. when multiple is specified), this attribute represents the number of rows in the list that should be visible at one time. Browsers are not required to present a select element as a scrolled list box. The default value is 0.

As described in the docs. <select size="1" multiple> will render a List box only 1 line visible and a scrollbar. So you are loosing the dropdown/arrow with the multiple attribute.

How can I slice an ArrayList out of an ArrayList in Java?

I have found a way if you know startIndex and endIndex of the elements one need to remove from ArrayList

Let al be the original ArrayList and startIndex,endIndex be start and end index to be removed from the array respectively:

al.subList(startIndex, endIndex + 1).clear();

How to efficiently count the number of keys/properties of an object in JavaScript?

as answered above: Object.keys(obj).length

But: as we have now a real Map class in ES6, I would suggest to use it instead of using the properties of an object.

const map = new Map();
map.set("key", "value");
map.size; // THE fastest way

C# DataRow Empty-check

I know this has been answered already and it's an old question, but here's an extension method to do the same:

public static class DataExtensions
{
    public static bool AreAllCellsEmpty(this DataRow row)
    {
        var itemArray = row.ItemArray;
        if(itemArray==null)
            return true;
        return itemArray.All(x => string.IsNullOrWhiteSpace(x.ToString()));            
    }
}

And you use it like so:

if (dr.AreAllCellsEmpty())
// etc

Regex to check with starts with http://, https:// or ftp://

test.matches() method checks all text.use test.find()

How to enable directory listing in apache web server

I solved the problem by enabling the mod_autoindex from Apache. It was disabled by default.

sudo a2enmod autoindex

"A namespace cannot directly contain members such as fields or methods"

The snippet you're showing doesn't seem to be directly responsible for the error.

This is how you can CAUSE the error:

namespace MyNameSpace
{
   int i; <-- THIS NEEDS TO BE INSIDE THE CLASS

   class MyClass
   {
      ...
   }
}

If you don't immediately see what is "outside" the class, this may be due to misplaced or extra closing bracket(s) }.

How to Set user name and Password of phpmyadmin

You can simply open the phpmyadmin page from your browser, then open any existing database -> go to Privileges tab, click on your root user and then a popup window will appear, you can set your password there.. Hope this Helps.

What's the difference between REST & RESTful

A "REST service" and a "RESTful service" are one and the same.

A RESTful system is any system that follows the REST conventions as defined in the original document that created the idea of RESTful networked applications.

It's worth noting there are varying levels of RESTfulness. Overall, REST is a style, not a standard, so there is room for interpretation based on needs. one example is hierarchical resource URLs (e.g. /things/ID/relatedthings) vs flat URLs (e.g. /things/ID and /relatedthings?thing=ID)

How to hide TabPage from TabControl

// inVisible
TabPage page2 = tabControl1.TabPages[0];
page2.Visible= false;
//Visible 
page2.Visible= true;
// disable
TabPage page2 = tabControl1.TabPages[0];
page2.Enabled = false;
// enable
page2.Enabled = true;
//Hide
tabCtrlTagInfo.TabPages(0).Hide()
tabCtrlTagInfo.TabPages(0).Show()

Just copy paste and try it,the above code has been tested in vs2010, it works.

"Use of undeclared type" in Swift, even though type is internal, and exists in same module

In my case, the issue was with a new class not being recognized. I solved the issue by deleting the class and re-adding it but this time checking the Watch App Extension option when creating the new class.

enter image description here

Please note that I do have a Watch App Extension in my Application.

How create Date Object with values in java

import java.io.*;
import java.util.*;
import java.util.HashMap;

public class Solution 
{

    public static void main(String[] args)
    {
        HashMap<Integer,String> hm = new HashMap<Integer,String>();
        hm.put(1,"SUNDAY");
        hm.put(2,"MONDAY");
        hm.put(3,"TUESDAY");
        hm.put(4,"WEDNESDAY");
        hm.put(5,"THURSDAY");
        hm.put(6,"FRIDAY");
        hm.put(7,"SATURDAY");
        Scanner in = new Scanner(System.in);
        String month = in.next();
        String day = in.next();
        String year = in.next();

        String format = year + "/" + month + "/" + day;
        Date date = null;
        try
        {
            SimpleDateFormat formatter = new SimpleDateFormat("yyyy/MM/dd");
            date = formatter.parse(format);
        }
        catch(Exception e){
        }
        Calendar c = Calendar.getInstance();
        c.setTime(date);
        int dayOfWeek = c.get(Calendar.DAY_OF_WEEK);
        System.out.println(hm.get(dayOfWeek));
    }
}

Download a specific tag with Git

try:

git clone -b <name_of_the_tag> <repository_url> <destination>

How do I do a Date comparison in Javascript?

I would rather use the Date valueOf method instead of === or !==

Seems like === is comparing internal Object's references and nothing concerning date.

Git, How to reset origin/master to a commit?

Assuming that your branch is called master both here and remotely, and that your remote is called origin you could do:

git reset --hard <commit-hash>
git push -f origin master

However, you should avoid doing this if anyone else is working with your remote repository and has pulled your changes. In that case, it would be better to revert the commits that you don't want, then push as normal.

Could someone explain this for me - for (int i = 0; i < 8; i++)

The generic view of a loop is

for (initialization; condition; increment-decrement){}

The first part initializes the code. The second part is the condition that will continue to run the loop as long as it is true. The last part is what will be run after each iteration of the loop. The last part is typically used to increment or decrement a counter, but it doesn't have to.

How to cast Object to its actual type?

This method might not be the most efficient but is simple and does the job.

It performs two operations: firstly it calls .ToString() which is basiclly a serialization, and then the deserialization using Newtonsoft nuget (which you must install).

public T Format<T>(Object obj) =>
    JsonConvert.DeserializeObject<T>(obj.ToString());

How may I align text to the left and text to the right in the same line?

If you just want to change alignment of text just make a classes

.left {
text-align: left;
}

and span that class through the text

<span class='left'>aligned left</span>

Understanding Popen.communicate

Do not use communicate(input=""). It writes input to the process, closes its stdin and then reads all output.

Do it like this:

p=subprocess.Popen(["python","1st.py"],stdin=PIPE,stdout=PIPE)

# get output from process "Something to print"
one_line_output = p.stdout.readline()

# write 'a line\n' to the process
p.stdin.write('a line\n')

# get output from process "not time to break"
one_line_output = p.stdout.readline() 

# write "n\n" to that process for if r=='n':
p.stdin.write('n\n') 

# read the last output from the process  "Exiting"
one_line_output = p.stdout.readline()

What you would do to remove the error:

all_the_process_will_tell_you = p.communicate('all you will ever say to this process\nn\n')[0]

But since communicate closes the stdout and stdin and stderr, you can not read or write after you called communicate.

What is The Rule of Three?

Rule of three in C++ is a fundamental principle of the design and the development of three requirements that if there is clear definition in one of the following member function, then the programmer should define the other two members functions together. Namely the following three member functions are indispensable: destructor, copy constructor, copy assignment operator.

Copy constructor in C++ is a special constructor. It is used to build a new object, which is the new object equivalent to a copy of an existing object.

Copy assignment operator is a special assignment operator that is usually used to specify an existing object to others of the same type of object.

There are quick examples:

// default constructor
My_Class a;

// copy constructor
My_Class b(a);

// copy constructor
My_Class c = a;

// copy assignment operator
b = a;

Convert javascript object or array to json for ajax data

I'm not entirely sure but I think you are probably surprised at how arrays are serialized in JSON. Let's isolate the problem. Consider following code:

var display = Array();
display[0] = "none";
display[1] = "block";
display[2] = "none";

console.log( JSON.stringify(display) );

This will print:

["none","block","none"]

This is how JSON actually serializes array. However what you want to see is something like:

{"0":"none","1":"block","2":"none"}

To get this format you want to serialize object, not array. So let's rewrite above code like this:

var display2 = {};
display2["0"] = "none";
display2["1"] = "block";
display2["2"] = "none";

console.log( JSON.stringify(display2) );

This will print in the format you want.

You can play around with this here: http://jsbin.com/oDuhINAG/1/edit?js,console

What ports does RabbitMQ use?

What ports is RabbitMQ using?

Default: 5672, the manual has the answer. It's defined in the RABBITMQ_NODE_PORT variable.

https://www.rabbitmq.com/configure.html#define-environment-variables

The number might be differently if changed by someone in the rabbitmq configuration file:

vi /etc/rabbitmq/rabbitmq-env.conf

Ask the computer to tell you:

sudo nmap -p 1-65535 localhost

Starting Nmap 5.51 ( http://nmap.org ) at 2014-09-19 13:50 EDT
Nmap scan report for localhost (127.0.0.1)
Host is up (0.00041s latency).
PORT      STATE         SERVICE
443/tcp   open          https
5672/tcp  open          amqp
15672/tcp open  unknown
35102/tcp open  unknown
59440/tcp open  unknown

Oh look, 5672, and 15672

Use netstat:

netstat -lntu
Active Internet connections (only servers)
Proto Recv-Q Send-Q Local Address               Foreign Address             State
tcp        0      0 0.0.0.0:15672               0.0.0.0:*                   LISTEN
tcp        0      0 0.0.0.0:55672               0.0.0.0:*                   LISTEN
tcp        0      0 :::5672                     :::*                        LISTEN

Oh look 5672.

use lsof:

eric@dev ~$ sudo lsof -i | grep beam
beam.smp  21216    rabbitmq   17u  IPv4 33148214      0t0  TCP *:55672 (LISTEN)
beam.smp  21216    rabbitmq   18u  IPv4 33148219      0t0  TCP *:15672 (LISTEN)

use nmap from a different machine, find out if 5672 is open:

sudo nmap -p 5672 10.0.1.71
Starting Nmap 5.51 ( http://nmap.org ) at 2014-09-19 13:19 EDT
Nmap scan report for 10.0.1.71
Host is up (0.00011s latency).
PORT     STATE SERVICE
5672/tcp open  amqp
MAC Address: 0A:40:0E:8C:75:6C (Unknown)    
Nmap done: 1 IP address (1 host up) scanned in 0.13 seconds

Try to connect to a port manually with telnet, 5671 is CLOSED:

telnet localhost 5671
Trying 127.0.0.1...
telnet: connect to address 127.0.0.1: Connection refused

Try to connect to a port manually with telnet, 5672 is OPEN:

telnet localhost 5672
Trying 127.0.0.1...
Connected to localhost.
Escape character is '^]'.

Check your firewall:

sudo cat /etc/sysconfig/iptables  

It should tell you what ports are made open:

-A INPUT -p tcp -m tcp --dport 5672 -j ACCEPT

Reapply your firewall:

sudo service iptables restart
iptables: Setting chains to policy ACCEPT: filter          [  OK  ]
iptables: Flushing firewall rules:                         [  OK  ]
iptables: Unloading modules:                               [  OK  ]
iptables: Applying firewall rules:                         [  OK  ]

Making a list of evenly spaced numbers in a certain range in python

Numpy's r_ convenience function can also create evenly spaced lists with syntax np.r_[start:stop:steps]. If steps is a real number (ending on j), then the end point is included, equivalent to np.linspace(start, stop, step, endpoint=1), otherwise not.

>>> np.r_[-1:1:6j, [0]*3, 5, 6]
array([-1. , -0.6, -0.2,  0.2,  0.6,  1.])

You can also directly concatente other arrays and also scalars:

>>> np.r_[-1:1:6j, [0]*3, 5, 6]
array([-1. , -0.6, -0.2,  0.2,  0.6,  1. ,  0. ,  0. ,  0. ,  5. ,  6. ])

registerForRemoteNotificationTypes: is not supported in iOS 8.0 and later

This is cleaner way I am doing and it just works great

if (floor(NSFoundationVersionNumber) < NSFoundationVersionNumber_iOS_8_0)
    [[UIApplication sharedApplication] registerForRemoteNotificationTypes:UIRemoteNotificationTypeBadge|
     UIRemoteNotificationTypeAlert| UIRemoteNotificationTypeSound];
     else {
         [application registerUserNotificationSettings:[UIUserNotificationSettings settingsForTypes:(UIUserNotificationTypeSound | UIUserNotificationTypeAlert | UIUserNotificationTypeBadge) categories:nil]]; 
         [application registerForRemoteNotifications];
     }

Shuffle an array with python, randomize array item order with python

In addition to the previous replies, I would like to introduce another function.

numpy.random.shuffle as well as random.shuffle perform in-place shuffling. However, if you want to return a shuffled array numpy.random.permutation is the function to use.

Get table names using SELECT statement in MySQL

I think it may be helpful to point out that if you want to select tables that contain specific words you can easily do it using the SELECT (instead of SHOW). Below query easily narrows down the search to tables that contain "keyword"

SELECT *
FROM information_schema.tables
WHERE table_name like "%keyword%"

How to determine if a string is a number with C++?

I propose a simple convention:

If conversion to ASCII is > 0 or it starts with 0 then it is a number. It is not perfect but fast.

Something like this:

string token0;

if (atoi(token0.c_str())>0 || isdigit(token0.c_str()[0]) ) { //this is a value
    // do what you need to do...
}

Calculate MD5 checksum for a file

I know that I am late to party but performed test before actually implement the solution.

I did perform test against inbuilt MD5 class and also md5sum.exe. In my case inbuilt class took 13 second where md5sum.exe too around 16-18 seconds in every run.

    DateTime current = DateTime.Now;
    string file = @"C:\text.iso";//It's 2.5 Gb file
    string output;
    using (var md5 = MD5.Create())
    {
        using (var stream = File.OpenRead(file))
        {
            byte[] checksum = md5.ComputeHash(stream);
            output = BitConverter.ToString(checksum).Replace("-", String.Empty).ToLower();
            Console.WriteLine("Total seconds : " + (DateTime.Now - current).TotalSeconds.ToString() + " " + output);
        }
    }

Angular exception: Can't bind to 'ngForIn' since it isn't a known native property

TL;DR;

Use let...of instead of let...in !!


If you're new to Angular (>2.x) and possibly migrating from Angular1.x, most likely you're confusing in with of. As andreas has mentioned in the comments below for ... of iterates over values of an object while for ... in iterates over properties in an object. This is a new feature introduced in ES2015.

Simply replace:

<!-- Iterate over properties (incorrect in our case here) -->
<div *ngFor="let talk in talks">

with

<!-- Iterate over values (correct way to use here) -->
<div *ngFor="let talk of talks">

So, you must replace in with of inside ngFor directive to get the values.

SQL subquery with COUNT help

This is probably the easiest way, not the prettiest though:

SELECT *,
    (SELECT Count(*) FROM eventsTable WHERE columnName = 'Business') as RowCount
    FROM eventsTable
    WHERE columnName = 'Business'

This will also work without having to use a group by

SELECT *, COUNT(*) OVER () as RowCount
    FROM eventsTables
    WHERE columnName = 'Business'

Highlight a word with jQuery

You need to get the content of the p tag and replace all the dolors in it with the highlighted version.

You don't even need to have jQuery for this. :-)

How to decrypt Hash Password in Laravel

For compare hashed password with the plain text password string you can use the PHP password_verify

if(password_verify('1234567', $crypt_password_string)) {
    // in case if "$crypt_password_string" actually hides "1234567"
}

Is try-catch like error handling possible in ASP Classic?

Regarding Wolfwyrd's anwer: "On Error Resume Next" in fact turns error handling off! Not on. On Error Goto 0 turns error-handling back ON because at the least, we want the machine to catch it if we didn't write it in ourselves. Off = leaving it to you to handle it.

If you use On Error Resume Next, you need to be careful about how much code you include after it: remember, the phrase "If Err.Number <> 0 Then" only refers to the most previous error triggered.

If your block of code after "On Error Resume Next" has several places where you might reasonably expect it to fail, then you must place "If Err.number <> 0" after each and every one of those possible failure lines, to check execution.

Otherwise, after "on error resume next" means just what it says - your code can fail on as many lines as it likes and execution will continue merrily along. That's why it's a pain in the ass.

What is the total amount of public IPv4 addresses?

According to Reserved IP addresses there are 588,514,304 reserved addresses and since there are 4,294,967,296 (2^32) IPv4 addressess in total, there are 3,706,452,992 public addresses.

And too many addresses in this post.

Saving images in Python at a very high quality

If you are using Matplotlib and are trying to get good figures in a LaTeX document, save as an EPS. Specifically, try something like this after running the commands to plot the image:

plt.savefig('destination_path.eps', format='eps')

I have found that EPS files work best and the dpi parameter is what really makes them look good in a document.

To specify the orientation of the figure before saving, simply call the following before the plt.savefig call, but after creating the plot (assuming you have plotted using an axes with the name ax):

ax.view_init(elev=elevation_angle, azim=azimuthal_angle)

Where elevation_angle is a number (in degrees) specifying the polar angle (down from vertical z axis) and the azimuthal_angle specifies the azimuthal angle (around the z axis).

I find that it is easiest to determine these values by first plotting the image and then rotating it and watching the current values of the angles appear towards the bottom of the window just below the actual plot. Keep in mind that the x, y, z, positions appear by default, but they are replaced with the two angles when you start to click+drag+rotate the image.

What is the difference between "screen" and "only screen" in media queries?

The answer by @hybrid is quite informative, except it doesn't explain the purpose as mentioned by @ashitaka "What if you use the Mobile First approach? So, we have the mobile CSS first and then use min-width to target larger sites. We shouldn't use the only keyword in that context, right? "

Want to add in here that the purpose is simply to prevent non supporting browsers to use that Other device style as if it starts from "screen" without it will take it for a screen whereas if it starts from "only" style will be ignored.

Answering to ashitaka consider this example

<link rel="stylesheet" type="text/css" 
  href="android.css" media="only screen and (max-width: 480px)" />
<link rel="stylesheet" type="text/css" 
  href="desktop.css" media="screen and (min-width: 481px)" />

If we don't use "only" it will still work as desktop-style will also be used striking android styles but with unnecessary overhead. In this case, IF a browser is non-supporting it will fallback to the second Style-sheet ignoring the first.

Installing PIL with pip

Try this:

sudo pip install PIL --allow-external PIL --allow-unverified PIL

postgresql - add boolean column to table set default

In psql alter column query syntax like this

Alter table users add column priv_user boolean default false ;

boolean value (true-false) save in DB like (t-f) value .

Foreign key referring to primary keys across multiple tables?

Technically possible. You would probably reference employees_ce in deductions and employees_sn. But why don't you merge employees_sn and employees_ce? I see no reason why you have two table. No one to many relationship. And (not in this example) many columns.

If you do two references for one column, an employee must have an entry in both tables.

How to Decode Json object in laravel and apply foreach loop on that in laravel

your string is NOT a valid json to start with.

a valid json will be,

{
    "area": [
        {
            "area": "kothrud"
        },
        {
            "area": "katraj"
        }
    ]
}

if you do a json_decode, it will yield,

stdClass Object
(
    [area] => Array
        (
            [0] => stdClass Object
                (
                    [area] => kothrud
                )

            [1] => stdClass Object
                (
                    [area] => katraj
                )

        )

)

Update: to use

$string = '

{
    "area": [
        {
            "area": "kothrud"
        },
        {
            "area": "katraj"
        }
    ]
}

';
            $area = json_decode($string, true);

            foreach($area['area'] as $i => $v)
            {
                echo $v['area'].'<br/>';
            }

Output:

kothrud
katraj

Update #2:

for that true:

When TRUE, returned objects will be converted into associative arrays. for more information, click here

How do I check that a number is float or integer?

Another method is:

    function isFloat(float) {
        return /\./.test(float.toString());
    }

Might not be as efficient as the others but another method all the same.

How to remove focus from input field in jQuery?

For all textbox :

$(':text').blur()

How to get character array from a string?

As hippietrail suggests, meder's answer can break surrogate pairs and misinterpret “characters.” For example:

_x000D_
_x000D_
// DO NOT USE THIS!
const a = ''.split('');
console.log(a);
_x000D_
_x000D_
_x000D_

I suggest using one of the following ES2015 features to correctly handle these character sequences.

Spread syntax (already answered by insertusernamehere)

_x000D_
_x000D_
const a = [...''];
console.log(a);
_x000D_
_x000D_
_x000D_

Array.from

_x000D_
_x000D_
const a = Array.from('');
console.log(a);
_x000D_
_x000D_
_x000D_

RegExp u flag

_x000D_
_x000D_
const a = ''.split(/(?=[\s\S])/u);
console.log(a);
_x000D_
_x000D_
_x000D_

Use /(?=[\s\S])/u instead of /(?=.)/u because . does not match newlines. If you are still in ES5.1 era (or if your browser doesn't handle this regex correctly - like Edge), you can use the following alternative (transpiled by Babel). Note, that Babel tries to also handle unmatched surrogates correctly. However, this doesn't seem to work for unmatched low surrogates.

_x000D_
_x000D_
const a = ''.split(/(?=(?:[\0-\uD7FF\uE000-\uFFFF]|[\uD800-\uDBFF][\uDC00-\uDFFF]|[\uD800-\uDBFF](?![\uDC00-\uDFFF])|(?:[^\uD800-\uDBFF]|^)[\uDC00-\uDFFF]))/);
console.log(a);
_x000D_
_x000D_
_x000D_

Reduce method (already answered by Mark Amery)

_x000D_
_x000D_
const s = '';
const a = [];
for (const s2 of s) {
   a.push(s2);
}
console.log(a);
_x000D_
_x000D_
_x000D_

Javascript checkbox onChange

try

totalCost.value = checkbox.checked ? 10 : calculate();

_x000D_
_x000D_
function change(checkbox) {_x000D_
  totalCost.value = checkbox.checked ? 10 : calculate();_x000D_
}_x000D_
_x000D_
function calculate() {_x000D_
  return other.value*2;_x000D_
}
_x000D_
input { display: block}
_x000D_
Checkbox: <input type="checkbox" onclick="change(this)"/>_x000D_
Total cost: <input id="totalCost" type="number" value=5 />_x000D_
Other: <input id="other" type="number" value=7 />
_x000D_
_x000D_
_x000D_

How do I select the parent form based on which submit button is clicked?

To get the form that the submit is inside why not just

this.form

Easiest & quickest path to the result.

gcc-arm-linux-gnueabi command not found

I had to cross compile C code in Ubuntu for ARM. This worked for me:

$ sudo apt install gcc-arm-none-eabi

Later, tested it on the qemu emulator

#Install qemu
sudo apt-get install qemu qemu-user-static qemu-system-arm

#Cross compile "helloworld.c"
$ arm-none-eabi-gcc --specs=rdimon.specs   -Wl,--start-group -lgcc -lc -lm -lrdimon -Wl,--end-group helloworld.c -o helloworld

#Run
qemu-arm-static helloworld

Proper way to assert type of variable in Python

Doing type('') is effectively equivalent to str and types.StringType

so type('') == str == types.StringType will evaluate to "True"

Note that Unicode strings which only contain ASCII will fail if checking types in this way, so you may want to do something like assert type(s) in (str, unicode) or assert isinstance(obj, basestring), the latter of which was suggested in the comments by 007Brendan and is probably preferred.

isinstance() is useful if you want to ask whether an object is an instance of a class, e.g:

class MyClass: pass

print isinstance(MyClass(), MyClass) # -> True
print isinstance(MyClass, MyClass()) # -> TypeError exception

But for basic types, e.g. str, unicode, int, float, long etc asking type(var) == TYPE will work OK.

Java error - "invalid method declaration; return type required"

Every method (other than a constructor) must have a return type.

public double diameter(){...

Condition within JOIN or WHERE

It is better to add the condition in the Join. Performance is more important than readability. For large datasets, it matters.

How to enable mod_rewrite for Apache 2.2

Use below command

sudo a2enmod rewrite

And the restart apache through below command

sudo service apache2 restart

Scheduling recurring task in Android

I have created on time task in which the task which user wants to repeat, add in the Custom TimeTask run() method. it is successfully reoccurring.

 import java.text.SimpleDateFormat;
 import java.util.Calendar;
 import java.util.Timer;
 import java.util.TimerTask;

 import android.os.Bundle;
 import android.view.View;
 import android.view.View.OnClickListener;
 import android.widget.Button;
 import android.widget.CheckBox;
 import android.widget.TextView;
 import android.app.Activity;
 import android.content.Intent;

 public class MainActivity extends Activity {

     CheckBox optSingleShot;
     Button btnStart, btnCancel;
     TextView textCounter;

     Timer timer;
     MyTimerTask myTimerTask;

     int tobeShown = 0  ;

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

    optSingleShot = (CheckBox)findViewById(R.id.singleshot);
    btnStart = (Button)findViewById(R.id.start);
    btnCancel = (Button)findViewById(R.id.cancel);
    textCounter = (TextView)findViewById(R.id.counter);
    tobeShown = 1;

    if(timer != null){
        timer.cancel();
    }

    //re-schedule timer here
    //otherwise, IllegalStateException of
    //"TimerTask is scheduled already" 
    //will be thrown
    timer = new Timer();
    myTimerTask = new MyTimerTask();

    if(optSingleShot.isChecked()){
        //singleshot delay 1000 ms
        timer.schedule(myTimerTask, 1000);
    }else{
        //delay 1000ms, repeat in 5000ms
        timer.schedule(myTimerTask, 1000, 1000);
    }

    btnStart.setOnClickListener(new OnClickListener(){

        @Override
        public void onClick(View arg0) {


            Intent i = new Intent(MainActivity.this, ActivityB.class);
            startActivity(i);

            /*if(timer != null){
                timer.cancel();
            }

            //re-schedule timer here
            //otherwise, IllegalStateException of
            //"TimerTask is scheduled already" 
            //will be thrown
            timer = new Timer();
            myTimerTask = new MyTimerTask();

            if(optSingleShot.isChecked()){
                //singleshot delay 1000 ms
                timer.schedule(myTimerTask, 1000);
            }else{
                //delay 1000ms, repeat in 5000ms
                timer.schedule(myTimerTask, 1000, 1000);
            }*/
        }});

    btnCancel.setOnClickListener(new OnClickListener(){

        @Override
        public void onClick(View v) {
            if (timer!=null){
                timer.cancel();
                timer = null;
            }
        }
    });

}

@Override
protected void onResume() {
    super.onResume();

    if(timer != null){
        timer.cancel();
    }

    //re-schedule timer here
    //otherwise, IllegalStateException of
    //"TimerTask is scheduled already" 
    //will be thrown
    timer = new Timer();
    myTimerTask = new MyTimerTask();

    if(optSingleShot.isChecked()){
        //singleshot delay 1000 ms
        timer.schedule(myTimerTask, 1000);
    }else{
        //delay 1000ms, repeat in 5000ms
        timer.schedule(myTimerTask, 1000, 1000);
    }
}


@Override
protected void onPause() {
    super.onPause();

    if (timer!=null){
        timer.cancel();
        timer = null;
    }

}

@Override
protected void onStop() {
    super.onStop();

    if (timer!=null){
        timer.cancel();
        timer = null;
    }

}

class MyTimerTask extends TimerTask {

    @Override
    public void run() {

        Calendar calendar = Calendar.getInstance();
        SimpleDateFormat simpleDateFormat = 
                new SimpleDateFormat("dd:MMMM:yyyy HH:mm:ss a");
        final String strDate = simpleDateFormat.format(calendar.getTime());

        runOnUiThread(new Runnable(){

            @Override
            public void run() {
                textCounter.setText(strDate);
            }});
    }
}

}

Optimal way to DELETE specified rows from Oracle

Store all the to be deleted ID's into a table. Then there are 3 ways. 1) loop through all the ID's in the table, then delete one row at a time for X commit interval. X can be a 100 or 1000. It works on OLTP environment and you can control the locks.

2) Use Oracle Bulk Delete

3) Use correlated delete query.

Single query is usually faster than multiple queries because of less context switching, and possibly less parsing.

How to extract year and month from date in PostgreSQL without using to_char() function?

date_part(text, timestamp)

e.g.

date_part('month', timestamp '2001-02-16 20:38:40'),
date_part('year', timestamp '2001-02-16 20:38:40') 

http://www.postgresql.org/docs/8.0/interactive/functions-datetime.html

A weighted version of random.choice

There is lecture on this by Sebastien Thurn in the free Udacity course AI for Robotics. Basically he makes a circular array of the indexed weights using the mod operator %, sets a variable beta to 0, randomly chooses an index, for loops through N where N is the number of indices and in the for loop firstly increments beta by the formula:

beta = beta + uniform sample from {0...2* Weight_max}

and then nested in the for loop, a while loop per below:

while w[index] < beta:
    beta = beta - w[index]
    index = index + 1

select p[index]

Then on to the next index to resample based on the probabilities (or normalized probability in the case presented in the course).

The lecture link: https://classroom.udacity.com/courses/cs373/lessons/48704330/concepts/487480820923

I am logged into Udacity with my school account so if the link does not work, it is Lesson 8, video number 21 of Artificial Intelligence for Robotics where he is lecturing on particle filters.

What is the best way to insert source code examples into a Microsoft Word document?

I recently came across this post and found some useful hints. However, I ended up using an entirely different approach which suited my needs. I am sharing the approach and my reasoning of why I chose this approach. The post is longer than I would have liked, but I believe screenshots are always helpful. Hopefully, the answer would be useful to someone.

My requirements were the following:

  1. Add code snippets to a word document, with syntax highlighting for easier visibility and differentiation of code and other text.
  2. Code snippet shall be inline with other text.
  3. Code snippet shall break across pages smoothly without any extra effort.
  4. Code snippet shall have a nice border.
  5. Code snippet shall have spell-check disabled.

My Approach is as listed below:

  1. Use external tool to achieve syntax highlighting requirement 1 above. One could use notepad plus plus as described above. However, I use the tool present here - http://www.planetb.ca/syntax-highlight-word. This gives me the option to use line number, as well as very nice syntax highlighting (Please use Google Chrome for this step, because syntax highlight is not copied when using Mozilla Firefox, as also pointed out by couple of user comments). Steps to achieve syntax highlighting are listed below:
  2. To achieve requirements 2, 3 and 4 above, use table in Microsoft word, to insert the code snippet. Steps are listed below:

    • Insert a table with single column.
    • Paste the copied text from step 1. in the table column. I have kept the line numbers to show how well this works with Microsoft word.
    • Apply border, as you like. I have used size 1pt. Resulting Microsoft word snippet will appear as shown in screenshot below. Note how nicely it breaks across the page - NO extra effort needed to manage this, which you would face if inserting "OpenDocument Text" object or if using "Simple TextBox". Syntax-highlighted code snippet pasted in Microsoft Word Table
  3. To achieve requirement 5, follow the steps below:

    • Select the entire table or the text.
    • Go to Review tab. Under Language, choose "Proofing Language". A new pop-up will be presented.
    • Select "Do not check spelling or grammar". Then, click OK. Disable spell-check
    • Resulting text has spell-check disabled. Final result is shown in the image below and meets all the requirements. Final Result - meets all the 5 requirements.

Please provide if you have any feedback or improvements or run into any issues with the approach.

Save each sheet in a workbook to separate CSV files

Please look into Von Pookie's answer, all credits to him/her.

 Sub asdf()
Dim ws As Worksheet, newWb As Workbook

Application.ScreenUpdating = False
For Each ws In Sheets(Array("EID Upload", "Wages with Locals Upload", "Wages without Local Upload"))
   ws.Copy
   Set newWb = ActiveWorkbook
   With newWb
      .SaveAs ws.Name, xlCSV
      .Close (False)
   End With
Next ws
Application.ScreenUpdating = True

End Sub

How do I make a WinForms app go Full Screen

You need to set your window to be topmost.

How to make the HTML link activated by clicking on the <li>?

a {
  display: block;
  position: relative;
}

I think that is all you need.

How to hide/show div tags using JavaScript?

try yo write document.getElementById('id').style.visibility="hidden";

How to customize the back button on ActionBar

The "up" affordance indicator is provided by a drawable specified in the homeAsUpIndicator attribute of the theme. To override it with your own custom version it would be something like this:

<style name="Theme.MyFancyTheme" parent="android:Theme.Holo">
    <item name="android:homeAsUpIndicator">@drawable/my_fancy_up_indicator</item>
</style>

If you are supporting pre-3.0 with your application be sure you put this version of the custom theme in values-v11 or similar.

ReferenceError: Invalid left-hand side in assignment

You have to use == to compare (or even ===, if you want to compare types). A single = is for assignment.

if (one == 'rock' && two == 'rock') {
    console.log('Tie! Try again!');
}

Display only date and no time

Just had to deal with this scenario myself - found a really easy way to do this, simply annotate your property in the model like this:

[DataType(DataType.Date)]
public DateTime? SomeDateProperty { get; set; }

It will hide the time button from the date picker too.

Sorry if this answer is a little late ;)

How to extract numbers from a string and get an array of ints?

I found this expression simplest

String[] extractednums = msg.split("\\\\D++");

method in class cannot be applied to given types

call generateNumbers(numbers);, your generateNumbers(); expects int[] as an argument ans you were passing none, thus the error

Remove scrollbar from iframe

Add scrolling="no" attribute to the iframe.

Excel error HRESULT: 0x800A03EC while trying to get range with cell's name

I got this when I forgot to unprotect workbook or sheet.

Using underscores in Java variables and method names

Here's a link to Sun's recommendations for Java. Not that you have to use these or even that their library code follows all of them, but it's a good start if you're going from scratch. Tool like Eclipse have built in formatters and cleanup tools that can help you conform to these conventions (or others that you define).

For me, '_' are too hard to type :)

How can I undo a `git commit` locally and on a remote after `git push`

Generally, make an "inverse" commit, using:

git revert 364705c

then send it to the remote as usual:

git push

This won't delete the commit: it makes an additional commit that undoes whatever the first commit did. Anything else, not really safe, especially when the changes have already been propagated.

gem install: Failed to build gem native extension (can't find header files)

Red Hat, Fedora:

yum -y install gcc mysql-devel ruby-devel rubygems
gem install -y mysql -- --with-mysql-config=/usr/bin/mysql_config

Debian, Ubuntu:

apt-get install libmysqlclient-dev ruby-dev
gem install mysql

Arch Linux:

pacman -S libmariadbclient
gem install mysql

How to increase Heap size of JVM

Following are few options available to change Heap Size.

-Xms<size>        set initial Java heap size
-Xmx<size>        set maximum Java heap size
-Xss<size>        set java thread stack size


java -Xmx256m TestData.java

How do I add a reference to the MySQL connector for .NET?

As mysql official documentation:

Starting with version 6.7, Connector/Net will no longer include the MySQL for Visual Studio integration. That functionality is now available in a separate product called MySQL for Visual Studio available using the MySQL Installer for Windows (see http://dev.mysql.com/tech-resources/articles/mysql-installer-for-windows.html).

Online Documentation:

MySQL Connector/Net Installation Instructions

INSERT INTO TABLE from comma separated varchar-list

Since there's no way to just pass this "comma-separated list of varchars", I assume some other system is generating them. If you can modify your generator slightly, it should be workable. Rather than separating by commas, you separate by union all select, and need to prepend a select also to the list. Finally, you need to provide aliases for the table and column in you subselect:

Create Table #IMEIS(
    imei varchar(15)
)
INSERT INTO #IMEIS(imei)
    SELECT * FROM (select '012251000362843' union all select '012251001084784' union all select '012251001168744' union all
                   select '012273007269862' union all select '012291000080227' union all select '012291000383084' union all
                   select '012291000448515') t(Col)
SELECT * from #IMEIS
DROP TABLE #IMEIS;

But noting your comment to another answer, about having 5000 entries to add. I believe the 256 tables per select limitation may kick in with the above "union all" pattern, so you'll still need to do some splitting of these values into separate statements.

Check if value exists in column in VBA

Just to modify scott's answer to make it a function:

Function FindFirstInRange(FindString As String, RngIn As Range, Optional UseCase As Boolean = True, Optional UseWhole As Boolean = True) As Variant

    Dim LookAtWhat As Integer

    If UseWhole Then LookAtWhat = xlWhole Else LookAtWhat = xlPart

    With RngIn
        Set FindFirstInRange = .Find(What:=FindString, _
                                     After:=.Cells(.Cells.Count), _
                                     LookIn:=xlValues, _
                                     LookAt:=LookAtWhat, _
                                     SearchOrder:=xlByRows, _
                                     SearchDirection:=xlNext, _
                                     MatchCase:=UseCase)

        If FindFirstInRange Is Nothing Then FindFirstInRange = False

    End With

End Function

This returns FALSE if the value isn't found, and if it's found, it returns the range.

You can optionally tell it to be case-sensitive, and/or to allow partial-word matches.

I took out the TRIM because you can add that beforehand if you want to.

An example:

MsgBox FindFirstInRange(StringToFind, Range("2:2"), TRUE, FALSE).Address

That does a case-sensitive, partial-word search on the 2nd row and displays a box with the address. The following is the same search, but a whole-word search that is not case-sensitive:

MsgBox FindFirstInRange(StringToFind, Range("2:2")).Address

You can easily tweak this function to your liking or change it from a Variant to to a boolean, or whatever, to speed it up a little.

Do note that VBA's Find is sometimes slower than other methods like brute-force looping or Match, so don't assume that it's the fastest just because it's native to VBA. It's more complicated and flexible, which also can make it not always as efficient. And it has some funny quirks to look out for, like the "Object variable or with block variable not set" error.

How to iterate over a std::map full of strings in C++

  1. Don't write a toString() method. This is not Java. Implement the stream operator for your class.

  2. Prefer using the standard algorithms over writing your own loop. In this situation, std::for_each() provides a nice interface to what you want to do.

  3. If you must use a loop, but don't intend to change the data, prefer const_iterator over iterator. That way, if you accidently try and change the values, the compiler will warn you.

Then:

std::ostream& operator<<(std::ostream& str,something const& data)
{
    data.print(str)
    return str;
}

void something::print(std::ostream& str) const
{
    std::for_each(table.begin(),table.end(),PrintData(str));
}

Then when you want to print it, just stream the object:

int main()
{
    something    bob;
    std::cout << bob;
}

If you actually need a string representation of the object, you can then use lexical_cast.

int main()
{
    something    bob;

    std::string  rope = boost::lexical_cast<std::string>(bob);
}

The details that need to be filled in.

class somthing
{
    typedef std::map<std::string,std::string>    DataMap;
    struct PrintData
    {
         PrintData(std::ostream& str): m_str(str) {}
         void operator()(DataMap::value_type const& data) const
         {
             m_str << data.first << "=" << data.second << "\n";
         }
         private:  std::ostream& m_str;
    };
    DataMap    table;
    public:
        void something::print(std::ostream& str);
};

What is the javascript filename naming convention?

One possible naming convention is to use something similar to the naming scheme jQuery uses. It's not universally adopted but it is pretty common.

product-name.plugin-ver.sion.filetype.js

where the product-name + plugin pair can also represent a namespace and a module. The version and filetype are usually optional.

filetype can be something relative to how the content of the file is. Often seen are:

  • min for minified files
  • custom for custom built or modified files

Examples:

  • jquery-1.4.2.min.js
  • jquery.plugin-0.1.js
  • myapp.invoice.js

Could not autowire field in spring. why?

Well there's a problem with the creation of the ContactServiceImpl bean. First, make sure that the class is actually instantiated by debugging the no-args constructor when the Spring context is initiated and when an instance of ContactController is created.

If the ContactServiceImpl is actually instantiated by the Spring context, but it's simply not matched against your @Autowire annotation, try being more explicit in your annotation injection. Here's a guy dealing with a similar problem as yours and giving some possible solutions:

http://blogs.sourceallies.com/2011/08/spring-injection-with-resource-and-autowired/

If you ask me, I think you'll be ok if you replace

@Autowired
private ContactService contactService;

with:

@Resource
@Qualifier("contactService")
private ContactService contactService;

Get the real width and height of an image with JavaScript? (in Safari/Chrome)

Jquery has two properties called naturalWidth and naturalHeight, you can use in this way.

$('.my-img')[0].naturalWidth 
$('.my-img')[0].naturalHeight

Where my-img is a class name used to select my image.

How to solve error "Missing `secret_key_base` for 'production' environment" (Rails 4.1)

For rails6, I was facing the same problem, as I was missing following files, once I added them, the issue resolved:

1. config/master.key
2. config/credentials.yml.enc

Make sure you have this files.!!!

Authorize attribute in ASP.NET MVC

Using [Authorize] attributes can help prevent security holes in your application. The way that MVC handles URL's (i.e. routing them to a controller rather than to an actual file) makes it difficult to actually secure everything via the web.config file.

Read more here: http://blogs.msdn.com/b/rickandy/archive/2012/03/23/securing-your-asp-net-mvc-4-app-and-the-new-allowanonymous-attribute.aspx (via archive.org)

How do I print out the contents of an object in Rails for easy debugging?

You need to use debug(@var). It's exactly like "print_r".

JQuery $.ajax() post - data in a java servlet

Simple method to sending data using java script and ajex call.

First right your form like this

<form id="frm_details" method="post" name="frm_details">
<input  id="email" name="email" placeholder="Your Email id" type="text" />
    <button class="subscribe-box__btn" type="submit">Need Assistance</button>
</form> 

javascript logic target on form id #frm_details after sumbit

$(function(){
        $("#frm_details").on("submit", function(event) {
            event.preventDefault();

            var formData = {
                'email': $('input[name=email]').val() //for get email 
            };
            console.log(formData);

            $.ajax({
                url: "/tsmisc/api/subscribe-newsletter",
                type: "post",
                data: formData,
                success: function(d) {
                    alert(d);
                }
            });
        });
    }) 





General 
Request URL:https://test.abc
Request Method:POST
Status Code:200 
Remote Address:13.76.33.57:443

From Data
email:[email protected]

How to use npm with ASP.NET Core

What is the right approach for doing this?

There are a lot of "right" approaches, you just have decide which one best suites your needs. It appears as though you're misunderstanding how to use node_modules...

If you're familiar with NuGet you should think of npm as its client-side counterpart. Where the node_modules directory is like the bin directory for NuGet. The idea is that this directory is just a common location for storing packages, in my opinion it is better to take a dependency on the packages you need as you have done in the package.json. Then use a task runner like Gulp for example to copy the files you need into your desired wwwroot location.

I wrote a blog post about this back in January that details npm, Gulp and a whole bunch of other details that are still relevant today. Additionally, someone called attention to my SO question I asked and ultimately answered myself here, which is probably helpful.

I created a Gist that shows the gulpfile.js as an example.

In your Startup.cs it is still important to use static files:

app.UseStaticFiles();

This will ensure that your application can access what it needs.

How to check a channel is closed or not without reading it?

I know this answer is so late, I have wrote this solution, Hacking Go run-time, It's not safety, It may crashes:

import (
    "unsafe"
    "reflect"
)


func isChanClosed(ch interface{}) bool {
    if reflect.TypeOf(ch).Kind() != reflect.Chan {
        panic("only channels!")
    }
    
    // get interface value pointer, from cgo_export 
    // typedef struct { void *t; void *v; } GoInterface;
    // then get channel real pointer
    cptr := *(*uintptr)(unsafe.Pointer(
        unsafe.Pointer(uintptr(unsafe.Pointer(&ch)) + unsafe.Sizeof(uint(0))),
    ))
    
    // this function will return true if chan.closed > 0
    // see hchan on https://github.com/golang/go/blob/master/src/runtime/chan.go 
    // type hchan struct {
    // qcount   uint           // total data in the queue
    // dataqsiz uint           // size of the circular queue
    // buf      unsafe.Pointer // points to an array of dataqsiz elements
    // elemsize uint16
    // closed   uint32
    // **
    
    cptr += unsafe.Sizeof(uint(0))*2
    cptr += unsafe.Sizeof(unsafe.Pointer(uintptr(0)))
    cptr += unsafe.Sizeof(uint16(0))
    return *(*uint32)(unsafe.Pointer(cptr)) > 0
}

Richtextbox wpf binding

I know this is an old post, but check out the Extended WPF Toolkit. It has a RichTextBox that supports what you are tryign to do.

How to fix getImageData() error The canvas has been tainted by cross-origin data?

Your problem is that you load an external image, meaning from another domain. This causes a security error when you try to access any data of your canvas context.

How to override a JavaScript function

You can override any built-in function by just re-declaring it.

parseFloat = function(a){
  alert(a)
};

Now parseFloat(3) will alert 3.

How to join components of a path when you are constructing a URL in Python

Using furl and regex (python 3)

>>> import re
>>> import furl
>>> p = re.compile(r'(\/)+')
>>> url = furl.furl('/media/path').add(path='/js/foo.js').url
>>> url
'/media/path/js/foo.js'
>>> p.sub(r"\1", url)
'/media/path/js/foo.js'
>>> url = furl.furl('/media/path').add(path='js/foo.js').url
>>> url
'/media/path/js/foo.js'
>>> p.sub(r"\1", url)
'/media/path/js/foo.js'
>>> url = furl.furl('/media/path/').add(path='js/foo.js').url
>>> url
'/media/path/js/foo.js'
>>> p.sub(r"\1", url)
'/media/path/js/foo.js'
>>> url = furl.furl('/media///path///').add(path='//js///foo.js').url
>>> url
'/media///path/////js///foo.js'
>>> p.sub(r"\1", url)
'/media/path/js/foo.js'

How to fix "containing working copy admin area is missing" in SVN?

I had the same problem, when I was trying to switch "C:\superfolder"

Error messages:

Directory 'C:\superfolder\subfolder\.svn'
containing
working copy admin area is missing
Please execute the 'Cleanup' command.

After trying to do a "cleanup", I got the following error:

 Cleanup failed to process the following paths:
 C:\superfolder\
'C:\superfolder\subfolder\' is not a working copy directory

Solution:

  1. Delete the folder "subfolder"
  2. Clean up the folder "superfolder"
  3. Try to switch again the folder "superfolder"

this worked for me. Please let me know if it also works for you.

TypeError: list indices must be integers or slices, not str

I had same error and the mistake was that I had added list and dictionary into the same list (object) and when I used to iterate over the list of dictionaries and use to hit a list (type) object then I used to get this error.

Its was a code error and made sure that I only added dictionary objects to that list and list typed object into the list, this solved my issue as well.

How to filter in NaN (pandas)?

This doesn't work because NaN isn't equal to anything, including NaN. Use pd.isnull(df.var2) instead.

XML Carriage return encoding

xml:space="preserve" has to work for all compliant XML parsers.

However, note that in HTML the line break is just whitespace and NOT a line break (this is represented with the <br /> (X)HTML tag, maybe this is the problem which you are facing.

You can also add &#10; and/or &#13; to insert CR/LF characters.

failed to push some refs to [email protected]

I had similar issue where local build was working fine however when I push my branch onto heroku it would fail to build. Issue was that I had some devDependencies in my package.json which were not installed during npm install which was causing my build to fail.

If you need access to packages declared under devDependencies in a different buildpack or at runtime, then you can set NPM_CONFIG_PRODUCTION=false or YARN_PRODUCTION=false to skip the pruning step.

Also you can move you devDependencies into dependencies...

How to make RatingBar to show five stars

Even i was facing the issue @Roland , I had included one more attribute called

android:layout_alignParentRight="true" 

in my RatingBar declaration in XML. This attribute prevented from setting of the stars required and setting up the NumStars

Keep posted on the issues you come across !

what is the most efficient way of counting occurrences in pandas?

I think df['word'].value_counts() should serve. By skipping the groupby machinery, you'll save some time. I'm not sure why count should be much slower than max. Both take some time to avoid missing values. (Compare with size.)

In any case, value_counts has been specifically optimized to handle object type, like your words, so I doubt you'll do much better than that.

Mysql 1050 Error "Table already exists" when in fact, it does not

First check if you are in the right database USE yourDB and try Select * from contenttype just to see what is it and if it exists really...

Ruby: Can I write multi-line string with no concatenation?

conn.exec = <<eos
  select attr1, attr2, attr3, attr4, attr5, attr6, attr7
  from table1, table2, table3, etc, etc, etc, etc, etc,
  where etc etc etc etc etc etc etc etc etc etc etc etc etc
eos

How to import a csv file using python with headers intact, where first column is a non-numerical

You can use pandas library and reference the rows and columns like this:

import pandas as pd

input = pd.read_csv("path_to_file");

#for accessing ith row:
input.iloc[i]

#for accessing column named X
input.X

#for accessing ith row and column named X
input.iloc[i].X

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

Logically OLAP functions are calculated after GROUP BY/HAVING, so you can only access columns in GROUP BY or columns with an aggregate function. Following looks strange, but is Standard SQL:

SELECT employee_number,
       MAX(MAX(course_completion_date)) 
           OVER (PARTITION BY course_code) AS max_course_date,
       MAX(course_completion_date) AS max_date
FROM employee_course_completion
WHERE course_code IN ('M910303', 'M91301R', 'M91301P')
GROUP BY employee_number, course_code

And as Teradata allows re-using an alias this also works:

SELECT employee_number,
       MAX(max_date) 
           OVER (PARTITION BY course_code) AS max_course_date,
       MAX(course_completion_date) AS max_date
FROM employee_course_completion
WHERE course_code IN ('M910303', 'M91301R', 'M91301P')
GROUP BY employee_number, course_code

PHP unable to load php_curl.dll extension

Solution:

Step1: Uncomment the php_curl.dll from php.ini

Step2: Copy the following three files from php installed directory.i.e "C:\\php7".

libeay32.dll,
libssh2.dll,
ssleay32.dll

Step3: Paste the files under two place

httpd.conf's ServerRoot directive. i.e "C\Apache24"
apache bin directory. i.e "C\Apache24\bin"

Step4: Restart apache.

That's all. I solve the problem by this way.Hope it might work for you.

The solution is given here. https://abcofcomputing.blogspot.com/2017/06/php7-unable-to-load-phpcurldll.html

Codeigniter: does $this->db->last_query(); execute a query?

For me save_queries option was turned off so,

$this->db->save_queries = TRUE; //Turn ON save_queries for temporary use.
$str = $this->db->last_query();
echo $str;

Ref: Can't get result from $this->db->last_query(); codeigniter

How to split a dataframe string column into two columns?

Use df.assign to create a new df. See http://pandas.pydata.org/pandas-docs/stable/user_guide/indexing.html#returning-a-view-versus-a-copy

split = df_selected['name'].str.split(',', 1, expand=True)
df_split = df_selected.assign(first_name=split[0], last_name=split[1])
df_split.drop('name', 1, inplace=True)

How to select specific form element in jQuery?

I prefer an id descendant selector of your #form2, like this:

$("#form2 #name").val("Hello World!");

http://api.jquery.com/descendant-selector/

How to for each the hashmap?

Streams Java 8

Along with forEach method that accepts a lambda expression we have also got stream APIs, in Java 8.

Iterate over entries (Using forEach and Streams):

sample.forEach((k,v) -> System.out.println(k + "=" + v)); 
sample.entrySet().stream().forEachOrdered((entry) -> {
            Object currentKey = entry.getKey();
            Object currentValue = entry.getValue();
            System.out.println(currentKey + "=" + currentValue);
        });
sample.entrySet().parallelStream().forEach((entry) -> {
            Object currentKey = entry.getKey();
            Object currentValue = entry.getValue();
            System.out.println(currentKey + "=" + currentValue);
        });

The advantage with streams is they can be parallelized easily and can be useful when we have multiple CPUs at disposal. We simply need to use parallelStream() in place of stream() above. With parallel streams it makes more sense to use forEach as forEachOrdered would make no difference in performance. If we want to iterate over keys we can use sample.keySet() and for values sample.values().

Why forEachOrdered and not forEach with streams ?

Streams also provide forEach method but the behaviour of forEach is explicitly nondeterministic where as the forEachOrdered performs an action for each element of this stream, in the encounter order of the stream if the stream has a defined encounter order. So forEach does not guarantee that the order would be kept. Also check this for more.

Failed to execute 'postMessage' on 'DOMWindow': https://www.youtube.com !== http://localhost:9000

Adding origin=${window.location.host} or "*" is not enough.

Add https:// before it and it will work.

Also, make sure that you are using an URL that can be embedded: take the video ID out and concatenate a string that has the YouTube video prefix and the video ID + embed definition.

Cannot deserialize the current JSON object (e.g. {"name":"value"}) into type 'System.Collections.Generic.List`1

Can you try to change your json without data key like below?

[{"target_id":9503123,"target_type":"user"}]

"You may need an appropriate loader to handle this file type" with Webpack and Babel

You need to install the es2015 preset:

npm install babel-preset-es2015

and then configure babel-loader:

{
    test: /\.jsx?$/,
    loader: 'babel-loader',
    exclude: /node_modules/,
    query: {
        presets: ['es2015']
    }
}

How to get the last char of a string in PHP?

You can find last character using php many ways like substr() and mb_substr().

If you’re using multibyte character encodings like UTF-8, use mb_substr instead of substr

Here i can show you both example:

<?php
    echo substr("testers", -1);
    echo mb_substr("testers", -1);
?>

LIVE DEMO

.gitignore file for java eclipse project

You need to add your source files with git add or the GUI equivalent so that Git will begin tracking them.

Use git status to see what Git thinks about the files in any given directory.

angular2: how to copy object into another object

You can do in this in Angular with ECMAScript6 by using the spread operator:

let copy = {...myObject};

ReactJS map through Object

Use Object.entries() function.

Object.entries(object) return:

[
    [key, value],
    [key, value],
    ...
]

see https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/entries

{Object.entries(subjects).map(([key, subject], i) => (
    <li className="travelcompany-input" key={i}>
        <span className="input-label">key: {i} Name: {subject.name}</span>
    </li>
))}

JavaScript and Threads

You could use Narrative JavaScript, a compiler that will transforms your code into a state machine, effectively allowing you to emulate threading. It does so by adding a "yielding" operator (notated as '->') to the language that allows you to write asynchronous code in a single, linear code block.

Getting a "This application is modifying the autolayout engine from a background thread" error?

For me, this error message originated from a banner from Admob SDK.

I was able to track the origin to "WebThread" by setting a conditional breakpoint.

conditional breakpoint to find who is updating ui from background thread

Then I was able to get rid of the issue by encapsulating the Banner creation with:

dispatch_async(dispatch_get_main_queue(), ^{
   _bannerForTableFooter = [[GADBannerView alloc] initWithAdSize:kGADAdSizeSmartBannerPortrait];
   ...
}

I don't know why this helped as I cannot see how this code was called from a non-main-thread.

Hope it can help anyone.

How do I bind a WPF DataGrid to a variable number of columns?

You can create a usercontrol with the grid definition and define 'child' controls with varied column definitions in xaml. The parent needs a dependency property for columns and a method for loading the columns:

Parent:


public ObservableCollection<DataGridColumn> gridColumns
{
  get
  {
    return (ObservableCollection<DataGridColumn>)GetValue(ColumnsProperty);
  }
  set
  {
    SetValue(ColumnsProperty, value);
  }
}
public static readonly DependencyProperty ColumnsProperty =
  DependencyProperty.Register("gridColumns",
  typeof(ObservableCollection<DataGridColumn>),
  typeof(parentControl),
  new PropertyMetadata(new ObservableCollection<DataGridColumn>()));

public void LoadGrid()
{
  if (gridColumns.Count > 0)
    myGrid.Columns.Clear();

  foreach (DataGridColumn c in gridColumns)
  {
    myGrid.Columns.Add(c);
  }
}

Child Xaml:


<local:parentControl x:Name="deGrid">           
  <local:parentControl.gridColumns>
    <toolkit:DataGridTextColumn Width="Auto" Header="1" Binding="{Binding Path=.}" />
    <toolkit:DataGridTextColumn Width="Auto" Header="2" Binding="{Binding Path=.}" />
  </local:parentControl.gridColumns>  
</local:parentControl>

And finally, the tricky part is finding where to call 'LoadGrid'.
I am struggling with this but got things to work by calling after InitalizeComponent in my window constructor (childGrid is x:name in window.xaml):

childGrid.deGrid.LoadGrid();

Related blog entry

How can I get the average (mean) of selected columns

Try using rowMeans:

z$mean=rowMeans(z[,c("x", "y")], na.rm=TRUE)

  w x  y mean
1 5 1  1    1
2 6 2  2    2
3 7 3  3    3
4 8 4 NA    4

Apache shutdown unexpectedly

That is because IIS is automatically running on your machine. IIS occupied both port 80 and 443.

I uninstalled IIS for using Apache httpd.