Programs & Examples On #Orca

The Orca MSI Editor is a table-editing tool that can be used to edit .msi files.

session not created: This version of ChromeDriver only supports Chrome version 74 error with ChromeDriver Chrome using Selenium

Updating the Google Chrome version to 74 worked for me.

Steps: 1. Go to Help -> About Google Chrome -> Chrome will automatically look for updates(update Chrome to the latest version)

enter image description here

Error: the entity type requires a primary key

The entity type 'DisplayFormatAttribute' requires a primary key to be defined.

In my case I figured out the problem was that I used properties like this:

public string LastName { get; set; }  //OK
public string Address { get; set; }   //OK 
public string State { get; set; }     //OK
public int? Zip { get; set; }         //OK
public EmailAddressAttribute Email { get; set; } // NOT OK
public PhoneAttribute PhoneNumber { get; set; }  // NOT OK

Not sure if there is a better way to solve it but I changed the Email and PhoneNumber attribute to a string. Problem solved.

Angular2 RC5: Can't bind to 'Property X' since it isn't a known property of 'Child Component'

I fixed it with adding the prefix (attr.) :

<create-report-card-form [attr.currentReportCardCount]="expression" ...

Unfortunately this haven't documented properly yet.

more detail here

AngularJS POST Fails: Response for preflight has invalid HTTP status code 404

Ok so here's how I figured this out. It all has to do with CORS policy. Before the POST request, Chrome was doing a preflight OPTIONS request, which should be handled and acknowledged by the server prior to the actual request. Now this is really not what I wanted for such a simple server. Hence, resetting the headers client side prevents the preflight:

app.config(function ($httpProvider) {
  $httpProvider.defaults.headers.common = {};
  $httpProvider.defaults.headers.post = {};
  $httpProvider.defaults.headers.put = {};
  $httpProvider.defaults.headers.patch = {};
});

The browser will now send a POST directly. Hope this helps a lot of folks out there... My real problem was not understanding CORS enough.

Link to a great explanation: http://www.html5rocks.com/en/tutorials/cors/

Kudos to this answer for showing me the way.

How to get response as String using retrofit without using GSON or any other library in android

** Update ** A scalars converter has been added to retrofit that allows for a String response with less ceremony than my original answer below.

Example interface --

public interface GitHubService {
    @GET("/users/{user}")
    Call<String> listRepos(@Path("user") String user);
}

Add the ScalarsConverterFactory to your retrofit builder. Note: If using ScalarsConverterFactory and another factory, add the scalars factory first.

Retrofit retrofit = new Retrofit.Builder()
    .baseUrl(BASE_URL)
    .addConverterFactory(ScalarsConverterFactory.create())
    // add other factories here, if needed.
    .build();

You will also need to include the scalars converter in your gradle file --

implementation 'com.squareup.retrofit2:converter-scalars:2.1.0'

--- Original Answer (still works, just more code) ---

I agree with @CommonsWare that it seems a bit odd that you want to intercept the request to process the JSON yourself. Most of the time the POJO has all the data you need, so no need to mess around in JSONObject land. I suspect your specific problem might be better solved using a custom gson TypeAdapter or a retrofit Converter if you need to manipulate the JSON. However, retrofit provides more the just JSON parsing via Gson. It also manages a lot of the other tedious tasks involved in REST requests. Just because you don't want to use one of the features, doesn't mean you have to throw the whole thing out. There are times you just want to get the raw stream, so here is how to do it -

First, if you are using Retrofit 2, you should start using the Call API. Instead of sending an object to convert as the type parameter, use ResponseBody from okhttp --

public interface GitHubService {
    @GET("/users/{user}")
    Call<ResponseBody> listRepos(@Path("user") String user);
}

then you can create and execute your call --

GitHubService service = retrofit.create(GitHubService.class);
Call<ResponseBody> result = service.listRepos(username);
result.enqueue(new Callback<ResponseBody>() {
    @Override
    public void onResponse(Response<ResponseBody> response) {
        try {
            System.out.println(response.body().string());
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    @Override
    public void onFailure(Throwable t) {
        e.printStackTrace();
    }
});

Note The code above calls string() on the response object, which reads the entire response into a String. If you are passing the body off to something that can ingest streams, you can call charStream() instead. See the ResponseBody docs.

bootstrap 3 wrap text content within div for horizontal alignment

Your code is working fine using bootatrap v3.3.7, but you can use word-break: break-word if it's not working at your end.

which would then look like this -

snap

_x000D_
_x000D_
<html>_x000D_
_x000D_
<head>_x000D_
    <link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css"_x000D_
        integrity="sha384-BVYiiSIFeK1dGmJRAkycuHAHRg32OmUcww7on3RYdg4Va+PmSTsz/K68vbdEjh4u" crossorigin="anonymous">_x000D_
</head>_x000D_
_x000D_
<body>_x000D_
    <div class="row" style="box-shadow: 0 0 30px black;">_x000D_
        <div class="col-6 col-sm-6 col-lg-4">_x000D_
            <h3 style="word-break: break-word;">2005 Volkswagen Jetta 2.5 Sedan (worcester http://www.massmotorcars.com)_x000D_
                $6900</h3>_x000D_
            <p>_x000D_
                <small>2005 volkswagen jetta 2.5 for sale has 110,000 miles powere doors,power windows,has ,car drives_x000D_
                    excellent ,comes with warranty if you&#39;re ...</small>_x000D_
            </p>_x000D_
            <p>_x000D_
                <a class="btn btn-default" href="/search/1355/detail/" role="button">View details &raquo;</a>_x000D_
                <button type="button" class="btn bookmark" id="1355">_x000D_
                    <span class="_x000D_
                      glyphicon glyphicon-star-empty "></span>_x000D_
                </button>_x000D_
            </p>_x000D_
        </div>_x000D_
        <!--/span-->_x000D_
        <div class="col-6 col-sm-6 col-lg-4">_x000D_
            <h3 style="word-break: break-word;">2006 Honda Civic EX Sedan (Worcester www.massmotorcars.com) $7950</h3>_x000D_
            <p>_x000D_
                <small>2006 honda civic ex has 110,176 miles, has power doors ,power windows,sun roof,alloy wheels,runs_x000D_
                    great, cd player, 4 cylinder engen, ...</small>_x000D_
            </p>_x000D_
            <p>_x000D_
                <a class="btn btn-default" href="/search/1356/detail/" role="button">View details &raquo;</a>_x000D_
                <button type="button" class="btn bookmark" id="1356">_x000D_
                    <span class="_x000D_
                      glyphicon glyphicon-star-empty "></span>_x000D_
                </button>_x000D_
            </p>_x000D_
_x000D_
        </div>_x000D_
        <!--/span-->_x000D_
        <div class="col-6 col-sm-6 col-lg-4">_x000D_
            <h3 style="word-break: break-word;">2004 Honda Civic LX Sedan (worcester www.massmotorcars.com) $5900</h3>_x000D_
            <p>_x000D_
                <small>2004 honda civic lx sedan has 134,000 miles, great looking car, interior and exterior looks_x000D_
                    nice,has_x000D_
                    cd player, power windows ...</small>_x000D_
            </p>_x000D_
            <p>_x000D_
                <a class="btn btn-default" href="/search/1357/detail/" role="button">View details &raquo;</a>_x000D_
                <button type="button" class="btn bookmark" id="1357">_x000D_
                    <span class="_x000D_
                      glyphicon glyphicon-star-empty "></span>_x000D_
                </button>_x000D_
            </p>_x000D_
        </div>_x000D_
    </div>_x000D_
</body>_x000D_
_x000D_
</html>
_x000D_
_x000D_
_x000D_

How to uninstall with msiexec using product id guid without .msi file present

There's no reason for the {} command not to work. The semi-obvious questions are:

  1. You are sure that the product is actually installed! There's something in ARP/Programs&Features.

  2. The original install is in fact visible in the current context. It looks as if it might have been a per-user install, and if you are logged in as somebody else now then it won't know about it - you'd need to log in under the same account as the original install.

  3. If the \windows\installer directory was damaged the cached file would be missing, and that's used to do the uninstall.

How do I debug error ECONNRESET in Node.js?

Try adding these options to socket.io:

const options = { transports: ['websocket'], pingTimeout: 3000, pingInterval: 5000 };

I hope this will help you !

java.rmi.ConnectException: Connection refused to host: 127.0.1.1;

On Windows make sure your Windows firewall is correctly configure / disabled. I had to disable the Windows firewall (because I didn't bother with configuring it) to get things to work even when I was testing with localhost.

Adding a custom header to HTTP request using angular.js

For me the following explanatory snippet worked. Perhaps you shouldn't use ' for header name?

{
   headers: { 
      Authorization: "Basic " + getAuthDigest(), 
      Accept: "text/plain" 
   }
}

I'm using $http.ajax(), though I wouldn't expect that to be a game changer.

How to pass data in the ajax DELETE request other than headers

I was able to successfully pass through the data attribute in the ajax method. Here is my code

$.ajax({
     url: "/api/Gigs/Cancel",
     type: "DELETE",
     data: {
             "GigId": link.attr('data-gig-id')
           }

  })

The link.attr method simply returned the value of 'data-gig-id' .

Numpy `ValueError: operands could not be broadcast together with shape ...`

If X and beta do not have the same shape as the second term in the rhs of your last line (i.e. nsample), then you will get this type of error. To add an array to a tuple of arrays, they all must be the same shape.

I would recommend looking at the numpy broadcasting rules.

How to add dll in c# project

Have you added the dll into your project references list? If not right click on the project "References" folder and selecet "Add Reference" then use browse to locate your science.dll, select it and click ok.

edit

I can't see the image of your VS instance that some people are referring to and I note that you now say that it works in Net4.0 and VS2010.

VS2008 projects support NET 3.5 by default. I expect that is the problem as your DLL may be NET 4.0 compliant but not NET 3.5.

How to name variables on the fly?

FAQ says:

If you have

varname <- c("a", "b", "d")

you can do

get(varname[1]) + 2

for

a + 2

or

assign(varname[1], 2 + 2)

for

a <- 2 + 2

So it looks like you use GET when you want to evaluate a formula that uses a variable (such as a concatenate), and ASSIGN when you want to assign a value to a pre-declared variable.

Syntax for assign: assign(x, value)

x: a variable name, given as a character string. No coercion is done, and the first element of a character vector of length greater than one will be used, with a warning.

value: value to be assigned to x.

Date validation with ASP.NET validator

A CustomValidator would also work here:

<asp:CustomValidator runat="server"
    ID="valDateRange" 
    ControlToValidate="txtDatecompleted"
    onservervalidate="valDateRange_ServerValidate" 
    ErrorMessage="enter valid date" />

Code-behind:

protected void valDateRange_ServerValidate(object source, ServerValidateEventArgs args)
{
    DateTime minDate = DateTime.Parse("1000/12/28");
    DateTime maxDate = DateTime.Parse("9999/12/28");
    DateTime dt;

    args.IsValid = (DateTime.TryParse(args.Value, out dt) 
                    && dt <= maxDate 
                    && dt >= minDate);
}

Socket transport "ssl" in PHP not enabled

I am using XAMPP and came across the same error. I had done all those steps, added environmental variables path, copied the dll's every directory possible, to /php, /apache/bin, /system32, /syswow64, etc.. but still got this error.

Then after checking the apache error log, I noticed the issue with using brackets in path.

PHP: syntax error, unexpected '(' in C:\Program Files (other)\xampp\php\php.ini on line 707 0 server certificate does NOT include an ID which matches the server name

If you have installed the server in "Program Files (x86)" directory, the same error might occur due to the non-escaped brackets.

To fix this, open php.ini file and locate the line containing "include_path" and enclose the path with double quotes to fix this error.

include_path="C:\Program Files (other)\xampp\php\PEAR"

SyntaxError: non-default argument follows default argument

As the error message says, non-default argument til should not follow default argument hgt.

Changing order of parameters (function call also be adjusted accordingly) or making hgt non-default parameter will solve your problem.

def a(len1, hgt=len1, til, col=0):

->

def a(len1, hgt, til, col=0):

UPDATE

Another issue that is hidden by the SyntaxError.

os.system accepts only one string parameter.

def a(len1, hgt, til, col=0):
    system('mode con cols=%s lines=%s' % (len1, hgt))
    system('title %s' % til)
    system('color %s' % col)

How do I use a delimiter with Scanner.useDelimiter in Java?

The scanner can also use delimiters other than whitespace.

Easy example from Scanner API:

 String input = "1 fish 2 fish red fish blue fish";

 // \\s* means 0 or more repetitions of any whitespace character 
 // fish is the pattern to find
 Scanner s = new Scanner(input).useDelimiter("\\s*fish\\s*");

 System.out.println(s.nextInt());   // prints: 1
 System.out.println(s.nextInt());   // prints: 2
 System.out.println(s.next());      // prints: red
 System.out.println(s.next());      // prints: blue

 // don't forget to close the scanner!!
 s.close(); 

The point is to understand the regular expressions (regex) inside the Scanner::useDelimiter. Find an useDelimiter tutorial here.


To start with regular expressions here you can find a nice tutorial.

Notes

abc…    Letters
123…    Digits
\d      Any Digit
\D      Any Non-digit character
.       Any Character
\.      Period
[abc]   Only a, b, or c
[^abc]  Not a, b, nor c
[a-z]   Characters a to z
[0-9]   Numbers 0 to 9
\w      Any Alphanumeric character
\W      Any Non-alphanumeric character
{m}     m Repetitions
{m,n}   m to n Repetitions
*       Zero or more repetitions
+       One or more repetitions
?       Optional character
\s      Any Whitespace
\S      Any Non-whitespace character
^…$     Starts and ends
(…)     Capture Group
(a(bc)) Capture Sub-group
(.*)    Capture all
(ab|cd) Matches ab or cd

Get a list of resources from classpath directory

I think you can leverage the [Zip File System Provider][1] to achieve this. When using FileSystems.newFileSystem it looks like you can treat the objects in that ZIP as a "regular" file.

In the linked documentation above:

Specify the configuration options for the zip file system in the java.util.Map object passed to the FileSystems.newFileSystem method. See the [Zip File System Properties][2] topic for information about the provider-specific configuration properties for the zip file system.

Once you have an instance of a zip file system, you can invoke the methods of the [java.nio.file.FileSystem][3] and [java.nio.file.Path][4] classes to perform operations such as copying, moving, and renaming files, as well as modifying file attributes.

The documentation for the jdk.zipfs module in [Java 11 states][5]:

The zip file system provider treats a zip or JAR file as a file system and provides the ability to manipulate the contents of the file. The zip file system provider can be created by [FileSystems.newFileSystem][6] if installed.

Here is a contrived example I did using your example resources. Note that a .zip is a .jar, but you could adapt your code to instead use classpath resources:

Setup

cd /tmp
mkdir -p x/y/z
touch x/y/z/{a,b,c}.html
echo 'hello world' > x/y/z/d
zip -r example.zip x

Java

import java.io.IOException;
import java.net.URI;
import java.nio.file.FileSystem;
import java.nio.file.FileSystems;
import java.nio.file.Files;
import java.util.Collections;
import java.util.stream.Collectors;

public class MkobitZipRead {

  public static void main(String[] args) throws IOException {
    final URI uri = URI.create("jar:file:/tmp/example.zip");
    try (
        final FileSystem zipfs = FileSystems.newFileSystem(uri, Collections.emptyMap());
    ) {
      Files.walk(zipfs.getPath("/")).forEach(path -> System.out.println("Files in zip:" + path));
      System.out.println("-----");
      final String manifest = Files.readAllLines(
          zipfs.getPath("x", "y", "z").resolve("d")
      ).stream().collect(Collectors.joining(System.lineSeparator()));
      System.out.println(manifest);
    }
  }

}

Output

Files in zip:/
Files in zip:/x/
Files in zip:/x/y/
Files in zip:/x/y/z/
Files in zip:/x/y/z/c.html
Files in zip:/x/y/z/b.html
Files in zip:/x/y/z/a.html
Files in zip:/x/y/z/d
-----
hello world

c#: getter/setter

public string Type { get; set; } 

is no different than doing

private string _Type;

public string Type
{    
  get { return _Type; }
  set { _Type = value; }
}

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

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

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

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

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

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

How to delete columns that contain ONLY NAs?

Another option is the janitor package:

df <- remove_empty_cols(df)

https://github.com/sfirke/janitor

nodejs npm global config missing on windows

It looks like the files npm uses to edit its config files are not created on a clean install, as npm has a default option for each one. This is why you can still get options with npm config get <option>: having those files only overrides the defaults, it doesn't create the options from scratch.

I had never touched my npm config stuff before today, even though I had had it for months now. None of the files were there yet, such as ~/.npmrc (on a Windows 8.1 machine with Git Bash), yet I could run npm config get <something> and, if it was a correct npm option, it returned a value. When I ran npm config set <option> <value>, the file ~/.npmrc seemed to be created automatically, with the option & its value as the only non-commented-out line.

As for deleting options, it looks like this just sets the value back to the default value, or does nothing if that option was never set or was unset & never reset. Additionally, if that option is the only explicitly set option, it looks like ~/.npmrc is deleted, too, and recreated if you set anything else later.

In your case (assuming it is still the same over a year later), it looks like you never set the proxy option in npm. Therefore, as npm's config help page says, it is set to whatever your http_proxy (case-insensitive) environment variable is. This means there is nothing to delete, unless you want to "delete" your HTTP proxy, although you could set the option or environment variable to something else and hope neither breaks your set-up somehow.

Does SVG support embedding of bitmap images?

It is also possible to include bitmaps. I think you also can use transformations on that.

Why is there no SortedList in Java?

List iterators guarantee first and foremost that you get the list's elements in the internal order of the list (aka. insertion order). More specifically it is in the order you've inserted the elements or on how you've manipulated the list. Sorting can be seen as a manipulation of the data structure, and there are several ways to sort the list.

I'll order the ways in the order of usefulness as I personally see it:

1. Consider using Set or Bag collections instead

NOTE: I put this option at the top because this is what you normally want to do anyway.

A sorted set automatically sorts the collection at insertion, meaning that it does the sorting while you add elements into the collection. It also means you don't need to manually sort it.

Furthermore if you are sure that you don't need to worry about (or have) duplicate elements then you can use the TreeSet<T> instead. It implements SortedSet and NavigableSet interfaces and works as you'd probably expect from a list:

TreeSet<String> set = new TreeSet<String>();
set.add("lol");
set.add("cat");
// automatically sorts natural order when adding

for (String s : set) {
    System.out.println(s);
}
// Prints out "cat" and "lol"

If you don't want the natural ordering you can use the constructor parameter that takes a Comparator<T>.

Alternatively, you can use Multisets (also known as Bags), that is a Set that allows duplicate elements, instead and there are third-party implementations of them. Most notably from the Guava libraries there is a TreeMultiset, that works a lot like the TreeSet.

2. Sort your list with Collections.sort()

As mentioned above, sorting of Lists is a manipulation of the data structure. So for situations where you need "one source of truth" that will be sorted in a variety of ways then sorting it manually is the way to go.

You can sort your list with the java.util.Collections.sort() method. Here is a code sample on how:

List<String> strings = new ArrayList<String>()
strings.add("lol");
strings.add("cat");

Collections.sort(strings);
for (String s : strings) {
    System.out.println(s);
}
// Prints out "cat" and "lol"

Using comparators

One clear benefit is that you may use Comparator in the sort method. Java also provides some implementations for the Comparator such as the Collator which is useful for locale sensitive sorting strings. Here is one example:

Collator usCollator = Collator.getInstance(Locale.US);
usCollator.setStrength(Collator.PRIMARY); // ignores casing

Collections.sort(strings, usCollator);

Sorting in concurrent environments

Do note though that using the sort method is not friendly in concurrent environments, since the collection instance will be manipulated, and you should consider using immutable collections instead. This is something Guava provides in the Ordering class and is a simple one-liner:

List<string> sorted = Ordering.natural().sortedCopy(strings);

3. Wrap your list with java.util.PriorityQueue

Though there is no sorted list in Java there is however a sorted queue which would probably work just as well for you. It is the java.util.PriorityQueue class.

Nico Haase linked in the comments to a related question that also answers this.

In a sorted collection you most likely don't want to manipulate the internal data structure which is why PriorityQueue doesn't implement the List interface (because that would give you direct access to its elements).

Caveat on the PriorityQueue iterator

The PriorityQueue class implements the Iterable<E> and Collection<E> interfaces so it can be iterated as usual. However, the iterator is not guaranteed to return elements in the sorted order. Instead (as Alderath points out in the comments) you need to poll() the queue until empty.

Note that you can convert a list to a priority queue via the constructor that takes any collection:

List<String> strings = new ArrayList<String>()
strings.add("lol");
strings.add("cat");

PriorityQueue<String> sortedStrings = new PriorityQueue(strings);
while(!sortedStrings.isEmpty()) {
    System.out.println(sortedStrings.poll());
}
// Prints out "cat" and "lol"

4. Write your own SortedList class

NOTE: You shouldn't have to do this.

You can write your own List class that sorts each time you add a new element. This can get rather computation heavy depending on your implementation and is pointless, unless you want to do it as an exercise, because of two main reasons:

  1. It breaks the contract that List<E> interface has because the add methods should ensure that the element will reside in the index that the user specifies.
  2. Why reinvent the wheel? You should be using the TreeSet or Multisets instead as pointed out in the first point above.

However, if you want to do it as an exercise here is a code sample to get you started, it uses the AbstractList abstract class:

public class SortedList<E> extends AbstractList<E> {

    private ArrayList<E> internalList = new ArrayList<E>();

    // Note that add(E e) in AbstractList is calling this one
    @Override 
    public void add(int position, E e) {
        internalList.add(e);
        Collections.sort(internalList, null);
    }

    @Override
    public E get(int i) {
        return internalList.get(i);
    }

    @Override
    public int size() {
        return internalList.size();
    }

}

Note that if you haven't overridden the methods you need, then the default implementations from AbstractList will throw UnsupportedOperationExceptions.

Java: convert List<String> to a String

You can use the apache commons library which has a StringUtils class and a join method.

Check this link: https://commons.apache.org/proper/commons-lang/javadocs/api.2.0/org/apache/commons/lang/StringUtils.html

Note that the link above may become obsolete over time, in which case you can just search the web for "apache commons StringUtils", which should allow you to find the latest reference.

(referenced from this thread) Java equivalents of C# String.Format() and String.Join()

change PATH permanently on Ubuntu

Assuming you want to add this path for all users on the system, add the following line to your /etc/profile.d/play.sh (and possibly play.csh, etc):

PATH=$PATH:/home/me/play
export PATH

TypeError: $(...).modal is not a function with bootstrap Modal

In my case, I use rails framework and require jQuery twice. I think that is a possible reason.

You can first check app/assets/application.js file. If the jquery and bootstrap-sprockets appears, then there is not need for a second library require. The file should be similar to this:

//= require jquery
//= require jquery_ujs
//= require turbolinks
//= require bootstrap-sprockets
//= require_tree .

Then check app/views/layouts/application.html.erb, and remove the script for requiring jquery. For example:

    <script src="https://ajax.googleapis.com/ajax/libs/jquery/2.2.0/jquery.min.js"></script>

I think sometimes when newbies use multiple tutorial code examples will cause this issue.

Reading a plain text file in Java

My favorite way to read a small file is to use a BufferedReader and a StringBuilder. It is very simple and to the point (though not particularly effective, but good enough for most cases):

BufferedReader br = new BufferedReader(new FileReader("file.txt"));
try {
    StringBuilder sb = new StringBuilder();
    String line = br.readLine();

    while (line != null) {
        sb.append(line);
        sb.append(System.lineSeparator());
        line = br.readLine();
    }
    String everything = sb.toString();
} finally {
    br.close();
}

Some has pointed out that after Java 7 you should use try-with-resources (i.e. auto close) features:

try(BufferedReader br = new BufferedReader(new FileReader("file.txt"))) {
    StringBuilder sb = new StringBuilder();
    String line = br.readLine();

    while (line != null) {
        sb.append(line);
        sb.append(System.lineSeparator());
        line = br.readLine();
    }
    String everything = sb.toString();
}

When I read strings like this, I usually want to do some string handling per line anyways, so then I go for this implementation.

Though if I want to actually just read a file into a String, I always use Apache Commons IO with the class IOUtils.toString() method. You can have a look at the source here:

http://www.docjar.com/html/api/org/apache/commons/io/IOUtils.java.html

FileInputStream inputStream = new FileInputStream("foo.txt");
try {
    String everything = IOUtils.toString(inputStream);
} finally {
    inputStream.close();
}

And even simpler with Java 7:

try(FileInputStream inputStream = new FileInputStream("foo.txt")) {     
    String everything = IOUtils.toString(inputStream);
    // do something with everything string
}

Why is Spring's ApplicationContext.getBean considered bad?

Reasons to prefer Service Locator over Inversion of Control (IoC) are:

  1. Service Locator is much, much easier for other people to following in your code. IoC is 'magic' but maintenance programmers must understand your convoluted Spring configurations and all the myriad of locations to figure out how you wired your objects.

  2. IoC is terrible for debugging configuration problems. In certain classes of applications the application will not start when misconfigured and you may not get a chance to step through what is going on with a debugger.

  3. IoC is primarily XML based (Annotations improve things but there is still a lot of XML out there). That means developers can't work on your program unless they know all the magic tags defined by Spring. It is not good enough to know Java anymore. This hinders less experience programmers (ie. it is actually poor design to use a more complicated solution when a simpler solution, such as Service Locator, will fulfill the same requirements). Plus, support for diagnosing XML problems is far weaker than support for Java problems.

  4. Dependency injection is more suited to larger programs. Most of the time the additional complexity is not worth it.

  5. Often Spring is used in case you "might want to change the implementation later". There are other ways of achieving this without the complexity of Spring IoC.

  6. For web applications (Java EE WARs) the Spring context is effectively bound at compile time (unless you want operators to grub around the context in the exploded war). You can make Spring use property files, but with servlets property files will need to be at a pre-determined location, which means you can't deploy multiple servlets of the same time on the same box. You can use Spring with JNDI to change properties at servlet startup time, but if you are using JNDI for administrator-modifiable parameters the need for Spring itself lessens (since JNDI is effectively a Service Locator).

  7. With Spring you can lose program Control if Spring is dispatching to your methods. This is convenient and works for many types of applications, but not all. You may need to control program flow when you need to create tasks (threads etc) during initialization or need modifiable resources that Spring didn't know about when the content was bound to your WAR.

Spring is very good for transaction management and has some advantages. It is just that IoC can be over-engineering in many situations and introduce unwarranted complexity for maintainers. Do not automatically use IoC without thinking of ways of not using it first.

Where is web.xml in Eclipse Dynamic Web Project

When you create a Dynamic Web Project you have the option to automatically create the web.xml file. If you don't mark that, the eclipse doesn't create it...

So, you have to add a new web.xml file in the WEB-INF folder.

To add a web.xml click on Next -> Next instead of Finish. You will find it on the final screen of the wizard.

How can I dynamically add items to a Java array?

You can dynamically add elements to an array using Collection Frameworks in JAVA. collection Framework doesn't work on primitive data types.

This Collection framework will be available in "java.util.*" package

For example if you use ArrayList,

Create an object to it and then add number of elements (any type like String, Integer ...etc)

ArrayList a = new ArrayList();
a.add("suman");
a.add(new Integer(3));
a.add("gurram");

Now you were added 3 elements to an array.

if you want to remove any of added elements

a.remove("suman");

again if you want to add any element

a.add("Gurram");

So the array size is incresing / decreasing dynamically..

Calculating text width

var calc = '<span style="display:none; margin:0 0 0 -999px">' + $('.move').text() + '</span>';

laravel Unable to prepare route ... for serialization. Uses Closure

I think that it's related with a route

Route::get('/article/{slug}', 'Front@slug');

associated with a particular method in my controller:

No, thats not it. The error message is coming from the route:cache command, not sure why clearing the cache calls this automatically.

The problem is a route which uses a Closure instead of a controller, which looks something like this:

//                       Thats the Closure
//                             v 
Route::get('/some/route', function() {
    return 'Hello World';
});

Since Closures can not be serialized, you can not cache your routes when you have routes which use closures.

JQUERY ajax passing value from MVC View to Controller

$('#btnSaveComments').click(function () {
    var comments = $('#txtComments').val();
    var selectedId = $('#hdnSelectedId').val();

    $.ajax({
        url: '<%: Url.Action("SaveComments")%>',
        data: { 'id' : selectedId, 'comments' : comments },
        type: "post",
        cache: false,
        success: function (savingStatu`enter code here`s) {
            $("#hdnOrigComments").val($('#txtComments').val());
            $('#lblCommentsNotification').text(savingStatus);
        },
        error: function (xhr, ajaxOptions, thrownError) {
            $('#lblCommentsNotification').text("Error encountered while saving the comments.");
        }
    });
});

How to pad a string to a fixed length with spaces in Python?

name = "John" // your variable
result = (name+"               ")[:15] # this adds 15 spaces to the "name"
                                       # but cuts it at 15 characters

How to get HttpContext.Current in ASP.NET Core?

As a general rule, converting a Web Forms or MVC5 application to ASP.NET Core will require a significant amount of refactoring.

HttpContext.Current was removed in ASP.NET Core. Accessing the current HTTP context from a separate class library is the type of messy architecture that ASP.NET Core tries to avoid. There are a few ways to re-architect this in ASP.NET Core.

HttpContext property

You can access the current HTTP context via the HttpContext property on any controller. The closest thing to your original code sample would be to pass HttpContext into the method you are calling:

public class HomeController : Controller
{
    public IActionResult Index()
    {
        MyMethod(HttpContext);

        // Other code
    }
}

public void MyMethod(Microsoft.AspNetCore.Http.HttpContext context)
{
    var host = $"{context.Request.Scheme}://{context.Request.Host}";

    // Other code
}

HttpContext parameter in middleware

If you're writing custom middleware for the ASP.NET Core pipeline, the current request's HttpContext is passed into your Invoke method automatically:

public Task Invoke(HttpContext context)
{
    // Do something with the current HTTP context...
}

HTTP context accessor

Finally, you can use the IHttpContextAccessor helper service to get the HTTP context in any class that is managed by the ASP.NET Core dependency injection system. This is useful when you have a common service that is used by your controllers.

Request this interface in your constructor:

public MyMiddleware(IHttpContextAccessor httpContextAccessor)
{
    _httpContextAccessor = httpContextAccessor;
}

You can then access the current HTTP context in a safe way:

var context = _httpContextAccessor.HttpContext;
// Do something with the current HTTP context...

IHttpContextAccessor isn't always added to the service container by default, so register it in ConfigureServices just to be safe:

public void ConfigureServices(IServiceCollection services)
{
    services.AddHttpContextAccessor();
    // if < .NET Core 2.2 use this
    //services.TryAddSingleton<IHttpContextAccessor, HttpContextAccessor>();

    // Other code...
}

Regular expression containing one word or another

You can use a single group for seconds/minutes. The following expression may suit your needs:

([0-9]+)\s*(seconds|minutes)

Online demo

Launch Image does not show up in my iOS App

So this has been quite painful for something that should be trivial. Here is what I did:

Use xcassets

I decided to use .xcassets versus the .xib for launch. I deleted the .xib. If you have images.xcassets already in your project then great, otherwise you can add one from File>New>file:

AddNewASsetCatalog

Create a Launch Image Set

Now create at a minimum a launchimage set and icon set in your .xcassets file by right clicking in the navigator area.

Add new Launch image and app icon

Update the App Icons and Launch Images Settings

Then I made sure that the "Apps icon and image sets" in my target are as below.

Very Important: Make sure the "Launch screen file" setting is blank.

Apps icon and image sets

Add the Images

Last but not least, the terminology used by Apple for the device selection is confusing. Initially I thought that since I am deploying for iOS8 only (iPhone Portrait), I can do this and just put in the iPhone 6 and iPhone 6+ launch images:

Devices

I quickly realized that is not the way this works and I was getting a warning: "An iPhone Retina (4-inch) launch image for iOS 7.0 and later is required."

So I had to select the iPhone under iOS 7.0 and later as well and add an Image for the iPhone 5s.

So to find out which boxes to check on the right, do not ask the question: What is my minimum iOS and device and device orientation but rather ask:

What devices out there can support my minimum iOS? Now What is the minimum iOS supported on those devices? And make sure you check all of those boxes. So for me, I am targeting iPhone 5s, 6 and 6 Plus at 8.0 but given that iPhone 5s can exist with 7.0, I need to check the 7.0 box as well to show the image placeholder. In other words, the (iOS) check box on the right shows you the minimum iOS version available for that device and you need to click it to show the image placeholder and put an image regardless of whether you are deploying at this iOS version or not.

Hope this helps somebody.

Adding all devices

enter image description here

Does "\d" in regex mean a digit?

In Python-style regex, \d matches any individual digit. If you're seeing something that doesn't seem to do that, please provide the full regex you're using, as opposed to just describing that one particular symbol.

>>> import re
>>> re.match(r'\d', '3')
<_sre.SRE_Match object at 0x02155B80>
>>> re.match(r'\d', '2')
<_sre.SRE_Match object at 0x02155BB8>
>>> re.match(r'\d', '1')
<_sre.SRE_Match object at 0x02155B80>

Wait 5 seconds before executing next line

Here's a solution using the new async/await syntax.

Be sure to check browser support as this is a language feature introduced with ECMAScript 6.

Utility function:

const delay = ms => new Promise(res => setTimeout(res, ms));

Usage:

const yourFunction = async () => {
  await delay(5000);
  console.log("Waited 5s");

  await delay(5000);
  console.log("Waited an additional 5s");
};

The advantage of this approach is that it makes your code look and behave like synchronous code.

How to make a smaller RatingBar?

the small one implement by the OS

<RatingBar
    android:id="@+id/ratingBar"
    style="?android:attr/ratingBarStyleSmall"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content" 
    />

Vertical Menu in Bootstrap

You can use the sidebar class to render list items vertically. Not exactly a menu, but close:

http://twitter.github.com/bootstrap/examples/fluid.html

Creating layout constraints programmatically

why can't I use a property like self.myView instead of a local variable like myView?

try using:

NSDictionaryOfVariableBindings(_view)

instead of self.view

How to remove all files from directory without removing directory in Node.js

To remove all files from a directory, first you need to list all files in the directory using fs.readdir, then you can use fs.unlink to remove each file. Also fs.readdir will give just the file names, you need to concat with the directory name to get the full path.

Here is an example

const fs = require('fs');
const path = require('path');

const directory = 'test';

fs.readdir(directory, (err, files) => {
  if (err) throw err;

  for (const file of files) {
    fs.unlink(path.join(directory, file), err => {
      if (err) throw err;
    });
  }
});

Update node version 14

There is a recursive flag that you can use in rmdir to remove all the files recursively. See nodejs docs for more information.

const fs = require('fs').promises;

const directory = 'test';

fs.rmdir(directory, { recursive: true })
  .then(() => console.log('directory removed!'));

Creating a generic method in C#

I like to start with a class like this class settings { public int X {get;set;} public string Y { get; set; } // repeat as necessary

 public settings()
 {
    this.X = defaultForX;
    this.Y = defaultForY;
    // repeat ...
 }
 public void Parse(Uri uri)
 {
    // parse values from query string.
    // if you need to distinguish from default vs. specified, add an appropriate property

 }

This has worked well on 100's of projects. You can use one of the many other parsing solutions to parse values.

Django Model() vs Model.objects.create()

The two syntaxes are not equivalent and it can lead to unexpected errors. Here is a simple example showing the differences. If you have a model:

from django.db import models

class Test(models.Model):

    added = models.DateTimeField(auto_now_add=True)

And you create a first object:

foo = Test.objects.create(pk=1)

Then you try to create an object with the same primary key:

foo_duplicate = Test.objects.create(pk=1)
# returns the error:
# django.db.utils.IntegrityError: (1062, "Duplicate entry '1' for key 'PRIMARY'")

foo_duplicate = Test(pk=1).save()
# returns the error:
# django.db.utils.IntegrityError: (1048, "Column 'added' cannot be null")

How to get selected path and name of the file opened with file dialog?

To extract only the filename from the path, you can do the following:

varFileName = Mid(fDialog.SelectedItems(1), InStrRev(fDialog.SelectedItems(1), "\") + 1, Len(fDialog.SelectedItems(1)))

Open URL in same window and in same tab

With html 5 you can use history API.

history.pushState({
  prevUrl: window.location.href

}, 'Next page', 'http://localhost/x/next_page');
history.go();

Then on the next page you can access state object like so

let url = history.state.prevUrl;
if (url) {
  console.log('user come from: '+ url)
}

Scroll to a div using jquery

There is no .scrollTo() method in jQuery, but there is a .scrollTop() one. .scrollTop expects a parameter, that is, the pixel value where the scrollbar should scroll to.

Example:

$(window).scrollTop(200);

will scroll the window (if there is enough content in it).

So you can get this desired value with .offset() or .position().

Example:

$(window).scrollTop($('#contact').offset().top);

This should scroll the #contact element into view.

The non-jQuery alternate method is .scrollIntoView(). You can call that method on any DOM element like:

$('#contact')[0].scrollIntoView(true);

true indicates that the element is positioned at the top whereas false would place it on the bottom of the view. The nice thing with the jQuery method is, you can even use it with fx functions like .animate(). So you might smooth scroll something.

Reference: .scrollTop(), .position(), .offset()

submit form on click event using jquery

it's because the name of the submit button is named "submit", change it to anything but "submit", try "submitme" and retry it. It should then work.

How to restrict the selectable date ranges in Bootstrap Datepicker?

Most answers and explanations are not to explain what is a valid string of endDate or startDate. Danny gave us two useful example.

$('#datepicker').datepicker({
    startDate: '-2m',
    endDate: '+2d'
});

But why?let's take a look at the source code at bootstrap-datetimepicker.js. There are some code begin line 1343 tell us how does it work.

if (/^[-+]\d+[dmwy]([\s,]+[-+]\d+[dmwy])*$/.test(date)) {
            var part_re = /([-+]\d+)([dmwy])/,
                parts = date.match(/([-+]\d+)([dmwy])/g),
                part, dir;
            date = new Date();
            for (var i = 0; i < parts.length; i++) {
                part = part_re.exec(parts[i]);
                dir = parseInt(part[1]);
                switch (part[2]) {
                    case 'd':
                        date.setUTCDate(date.getUTCDate() + dir);
                        break;
                    case 'm':
                        date = Datetimepicker.prototype.moveMonth.call(Datetimepicker.prototype, date, dir);
                        break;
                    case 'w':
                        date.setUTCDate(date.getUTCDate() + dir * 7);
                        break;
                    case 'y':
                        date = Datetimepicker.prototype.moveYear.call(Datetimepicker.prototype, date, dir);
                        break;
                }
            }
            return UTCDate(date.getUTCFullYear(), date.getUTCMonth(), date.getUTCDate(), date.getUTCHours(), date.getUTCMinutes(), date.getUTCSeconds(), 0);
        }

There are four kinds of expressions.

  • w means week
  • m means month
  • y means year
  • d means day

Look at the regular expression ^[-+]\d+[dmwy]([\s,]+[-+]\d+[dmwy])*$. You can do more than these -0d or +1m.

Try harder like startDate:'+1y,-2m,+0d,-1w'.And the separator , could be one of [\f\n\r\t\v,]

Error:Execution failed for task ':ProjectName:mergeDebugResources'. > Crunching Cruncher *some file* failed, see logs

It may happens because fake png files. You can use this command to check out fake pngs.

cd <YOUR_PROJECT/res/> && find . -name *.png | xargs pngcheck

And then,use ImageEditor(Ex, Pinta) to open fake pngs and re-save them to png.

Good luck.

JavaFX Location is not set error message

I had this problem and found this post. My issue was just a file name issue.

FXMLLoader(getClass().getResource("/com/companyname/reports/" +
report.getClass().getCanonicalName().substring(18).replaceAll("Controller", "") +
".fxml"));

Parent root = (Parent) loader.load();

I have an xml that this is all coming from and I have made sure that my class is the same as the fxml file less the word controller.

I messed up the substring so the path was wrong...sure enough after I fixed the file name it worked.

To make a long story short I think that the problem is either the filename is named improperly or the path is wrong.

ADDITION: I have since moved to a Maven Project. The non Maven way is to have everything inside of your project path. The Maven way which was listed in the answer below was a bit frustrating at the start but I made a change to my code as follows:

FXMLLoader loader = new FXMLLoader(ReportMenu.this.getClass().getResource("/fxml/" + report.getClass().getCanonicalName().substring(18).replaceAll("Controller", "") + ".fxml"));

HTML/CSS: how to put text both right and left aligned in a paragraph

The only half-way proper way to do this is

<p>
  <span style="float: right">Text on the right</span>
  <span style="float: left">Text on the left</span>
</p> 

however, this will get you into trouble if the text overflows. If you can, use divs (block level elements) and give them a fixed width.

A table (or a number of divs with the according display: table / table-row / table-cell properties) would in fact be the safest solution for this - it will be impossible to break, even if you have lots of difficult content.

How to get the connection String from a database

The easiest way to get the connection string is using the "Server Explorer" window in Visual Studio (menu View, Server Explorer) and connect to the server from that window.

Then you can see the connection string in the properties of the connected server (choose the connection and press F4 or Alt+Enter or choose Properties on the right click menu).

Advanced connection string settings: when creating the connection, you can modify any of the advanced connection string options, like MARS, resiliency, timeot, pooling configuration, etc. by clicking on the "Advanced..." button on the bottom of the "Add connection" dialog. You can access this dialog later by right clicking the Data Connection, and choosing "Modify connection...". The available advanced options vary by server type.

If you create the database using SQL Server Management Studio, the database will be created in a server instance, so that, to deploy your application you'll have to make a backup of the database and deploy it in the deployment SQL Server. Alternatively, you can use a data file using SQL Server Express (localDB in SQL Server 2012), that will be easily distributed with your app.

I.e. if it's an ASP.NET app, there's an App_Datafolder. If you right click it you can add a new element, which can be a SQL Server Database. This file will be on that folder, will work with SQL Express, and will be easy to deploy. You need SQL Express / localDB installed on your machine for this to work.

How do you Change a Package's Log Level using Log4j?

This work for my:

log4j.logger.org.hibernate.type=trace

Also can try:

log4j.category.org.hibernate.type=trace

Chaining multiple filter() in Django, is this a bug?

As you can see in the generated SQL statements the difference is not the "OR" as some may suspect. It is how the WHERE and JOIN is placed.

Example1 (same joined table) :

(example from https://docs.djangoproject.com/en/dev/topics/db/queries/#spanning-multi-valued-relationships)

Blog.objects.filter(entry__headline__contains='Lennon', entry__pub_date__year=2008)

This will give you all the Blogs that have one entry with both (entry_headline_contains='Lennon') AND (entry__pub_date__year=2008), which is what you would expect from this query. Result: Book with {entry.headline: 'Life of Lennon', entry.pub_date: '2008'}

Example 2 (chained)

Blog.objects.filter(entry__headline__contains='Lennon').filter(entry__pub_date__year=2008)

This will cover all the results from Example 1, but it will generate slightly more result. Because it first filters all the blogs with (entry_headline_contains='Lennon') and then from the result filters (entry__pub_date__year=2008).

The difference is that it will also give you results like: Book with {entry.headline: 'Lennon', entry.pub_date: 2000}, {entry.headline: 'Bill', entry.pub_date: 2008}

In your case

I think it is this one you need:

Book.objects.filter(inventory__user__profile__vacation=False, inventory__user__profile__country='BR')

And if you want to use OR please read: https://docs.djangoproject.com/en/dev/topics/db/queries/#complex-lookups-with-q-objects

Spring MVC Multipart Request with JSON

We've seen in our projects that a post request with JSON and files is creating a lot of confusion between the frontend and backend developers, leading to unnecessary wastage of time.

Here's a better approach: convert file bytes array to Base64 string and send it in the JSON.

public Class UserDTO {
    private String firstName;
    private String lastName;
    private FileDTO profilePic; 
}

public class FileDTO {
    private String base64;
    // just base64 string is enough. If you want, send additional details
    private String name;
    private String type;
    private String lastModified;
}

@PostMapping("/user")
public String saveUser(@RequestBody UserDTO user) {
    byte[] fileBytes = Base64Utils.decodeFromString(user.getProfilePic().getBase64());
    ....
}

JS code to convert file to base64 string:

var reader = new FileReader();
reader.readAsDataURL(file);
reader.onload = function () {

  const userDTO = {
    firstName: "John",
    lastName: "Wick",
    profilePic: {
      base64: reader.result,
      name: file.name,
      lastModified: file.lastModified,
      type: file.type
    }
  }
  
  // post userDTO
};
reader.onerror = function (error) {
  console.log('Error: ', error);
};

Check if bash variable equals 0

Double parenthesis (( ... )) is used for arithmetic operations.

Double square brackets [[ ... ]] can be used to compare and examine numbers (only integers are supported), with the following operators:

· NUM1 -eq NUM2 returns true if NUM1 and NUM2 are numerically equal.

· NUM1 -ne NUM2 returns true if NUM1 and NUM2 are not numerically equal.

· NUM1 -gt NUM2 returns true if NUM1 is greater than NUM2.

· NUM1 -ge NUM2 returns true if NUM1 is greater than or equal to NUM2.

· NUM1 -lt NUM2 returns true if NUM1 is less than NUM2.

· NUM1 -le NUM2 returns true if NUM1 is less than or equal to NUM2.

For example

if [[ $age > 21 ]] # bad, > is a string comparison operator

if [ $age > 21 ] # bad, > is a redirection operator

if [[ $age -gt 21 ]] # okay, but fails if $age is not numeric

if (( $age > 21 )) # best, $ on age is optional

What is an idempotent operation?

It is any operation that every nth result will result in an output matching the value of the 1st result. For instance the absolute value of -1 is 1. The absolute value of the absolute value of -1 is 1. The absolute value of the absolute value of absolute value of -1 is 1. And so on.

See also: When would be a really silly time to use recursion?

How to Concatenate Numbers and Strings to Format Numbers in T-SQL?

If you are using SQL Server 2012+ you can use CONCAT function in which we don't have to do any explicit conversion

SET @ActualWeightDIMS = Concat(@Actual_Dims_Lenght, 'x', @Actual_Dims_Width, 'x' 
                        , @Actual_Dims_Height) 

how to change the dist-folder path in angular-cli after 'ng build'

For Angular 6+ things have changed a little.

Define where ng build generates app files

Cli setup is now done in angular.json (replaced .angular-cli.json) in your workspace root directory. The output path in default angular.json should look like this (irrelevant lines removed):

{
  "projects": {
    "my-app-name": {
    "architect": {
      "options": {
         "outputPath": "dist/my-app-name",

Obviously, this will generate your app in WORKSPACE/dist/my-app-name. Modify outputPath if you prefer another directory.

You can overwrite the output path using command line arguments (e.g. for CI jobs):

ng build -op dist/example
ng build --output-path=dist/example

S.a. https://github.com/angular/angular-cli/wiki/build

Hosting angular app in subdirectory

Setting the output path, will tell angular where to place the "compiled" files but however you change the output path, when running the app, angular will still assume that the app is hosted in the webserver's document root.

To make it work in a sub directory, you'll have to set the base href.

In angular.json:

{
  "projects": {
    "my-app-name": {
    "architect": {
      "options": {
         "baseHref": "/my-folder/",

Cli:

ng build --base-href=/my-folder/

If you don't know where the app will be hosted on build time, you can change base tag in generated index.html.

Here's an example how we do it in our docker container:

entrypoint.sh

if [ -n "${BASE_PATH}" ]
then
  files=( $(find . -name "index.html") )
  cp -n "${files[0]}" "${files[0]}.org"
  cp "${files[0]}.org" "${files[0]}"
  sed -i "s*<base href=\"/\">*<base href=\"${BASE_PATH}\">*g" "${files[0]}"
fi

How to set a cookie to expire in 1 hour in Javascript?

You can write this in a more compact way:

var now = new Date();
now.setTime(now.getTime() + 1 * 3600 * 1000);
document.cookie = "name=value; expires=" + now.toUTCString() + "; path=/";

And for someone like me, who wasted an hour trying to figure out why the cookie with expiration is not set up (but without expiration can be set up) in Chrome, here is in answer:

For some strange reason Chrome team decided to ignore cookies from local pages. So if you do this on localhost, you will not be able to see your cookie in Chrome. So either upload it on the server or use another browser.

#ifdef replacement in the Swift language

As of Swift 4.1, if all you need is just check whether the code is built with debug or release configuration, you may use the built-in functions:

  • _isDebugAssertConfiguration() (true when optimization is set to -Onone)
  • _isReleaseAssertConfiguration() (true when optimization is set to -O) (not available on Swift 3+)
  • _isFastAssertConfiguration() (true when optimization is set to -Ounchecked)

e.g.

func obtain() -> AbstractThing {
    if _isDebugAssertConfiguration() {
        return DecoratedThingWithDebugInformation(Thing())
    } else {
        return Thing()
    }
}

Compared with preprocessor macros,

  • ? You don't need to define a custom -D DEBUG flag to use it
  • ~ It is actually defined in terms of optimization settings, not Xcode build configuration
  • ? Undocumented, which means the function can be removed in any update (but it should be AppStore-safe since the optimizer will turn these into constants)

  • ? Using in if/else will always generate a "Will never be executed" warning.

Installing a specific version of angular with angular cli

Edit #2 ( 7/2/2017)

If you install the angular cli right now, you'd probably have the new name of angular cli which is @angular/cli, so you need to uninstall it using

npm uninstall -g @angular/cli

and follow the code above. I'm still getting upvotes for this so I updated my answer for those who want to use the older version for some reasons.


Edit #1

If you really want to create a new project with previous version of Angular using the cli, try to downgrade the angular-cli before the final release. Something like:

npm uninstall -g angular-cli
npm cache clean
npm install -g [email protected]

Initial

You can change the version of the angular in the package.json . I'm guessing you want to use older version of angular but I suggest you use the latest version. Using:

ng new app-name

will always use the latest version of angular.

Invariant Violation: Objects are not valid as a React child

For anybody using Firebase with Android, this only breaks Android. My iOS emulation ignores it.

And as posted by Apoorv Bankey above.

Anything above Firebase V5.0.3, for Android, atm is a bust. Fix:

npm i --save [email protected]

Confirmed numerous times here https://github.com/firebase/firebase-js-sdk/issues/871

Resize font-size according to div size

The answer that i am presenting is very simple, instead of using "px","em" or "%", i'll use "vw". In short it might look like this:- h1 {font-size: 5.9vw;} when used for heading purposes.

See this:Demo

For more details:Main tutorial

using wildcards in LDAP search filters/queries

Your best bet would be to anticipate prefixes, so:

"(|(displayName=SEARCHKEY*)(displayName=ITSM - SEARCHKEY*)(displayName=alt prefix - SEARCHKEY*))"

Clunky, but I'm doing a similar thing within my organization.

How can I force clients to refresh JavaScript files?

We have been creating a SaaS for users and providing them a script to attach in their website page, and it was not possible to attach a version with the script as user will attach the script to their website for functionalities and i can't force them to change the version each time we update the script

So, we found a way to load the newer version of the script each time user calls the original script

the script link provided to user

<script src="https://thesaasdomain.com/somejsfile.js" data-ut="user_token"></script>

the script file

if($('script[src^="https://thesaasdomain.com/somejsfile.js?"]').length !== 0) {
   init();
} else {
   loadScript("https://thesaasdomain.com/somejsfile.js?" + guid());
}

var loadscript = function(scriptURL) {
   var head = document.getElementsByTagName('head')[0];
   var script = document.createElement('script');
   script.type = 'text/javascript';
   script.src = scriptURL;
   head.appendChild(script);
}

var guid = function() {
    return 'xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx'.replace(/[xy]/g, function(c) {
        var r = Math.random() * 16 | 0, v = c == 'x' ? r : (r & 0x3 | 0x8);
        return v.toString(16);
    });
}

var init = function() {
    // our main code
}

Explanation:

The user have attached the script provided to them in their website and we checked for the unique token attached with the script exists or not using jQuery selector and if not then load it dynamically with newer token (or version)

This is call the same script twice which could be a performance issue, but it really solves the problem of forcing the script to not load from the cache without putting the version in the actual script link given to the user or client

Disclaimer: Do not use if performance is a big issue in your case.

Javascript - object key->value

var o = { cat : "meow", dog : "woof"};
var x = Object.keys(o);

for (i=0; i<x.length; i++) {
  console.log(o[x[i]]);
}

IAB

delete all from table

You can also use truncate.

truncate table table_name;

How to get the caret column (not pixels) position in a textarea, in characters, from the start?

With Firefox, Safari (and other Gecko based browsers) you can easily use textarea.selectionStart, but for IE that doesn't work, so you will have to do something like this:

function getCaret(node) {
  if (node.selectionStart) {
    return node.selectionStart;
  } else if (!document.selection) {
    return 0;
  }

  var c = "\001",
      sel = document.selection.createRange(),
      dul = sel.duplicate(),
      len = 0;

  dul.moveToElementText(node);
  sel.text = c;
  len = dul.text.indexOf(c);
  sel.moveStart('character',-1);
  sel.text = "";
  return len;
}

(complete code here)

I also recommend you to check the jQuery FieldSelection Plugin, it allows you to do that and much more...

Edit: I actually re-implemented the above code:

function getCaret(el) { 
  if (el.selectionStart) { 
    return el.selectionStart; 
  } else if (document.selection) { 
    el.focus(); 

    var r = document.selection.createRange(); 
    if (r == null) { 
      return 0; 
    } 

    var re = el.createTextRange(), 
        rc = re.duplicate(); 
    re.moveToBookmark(r.getBookmark()); 
    rc.setEndPoint('EndToStart', re); 

    return rc.text.length; 
  }  
  return 0; 
}

Check an example here.

Run a mySQL query as a cron job?

This was a very handy page as I have a requirement to DELETE records from a mySQL table where the expiry date is < Today.

I am on a shared host and CRON did not like the suggestion AndrewKDay. it also said (and I agree) that exposing the password in this way could be insecure.

I then tried turning Events ON in phpMyAdmin but again being on a shared host this was a no no. Sorry fancyPants.

So I turned to embedding the SQL script in a PHP file. I used the example [here][1]

[1]: https://www.w3schools.com/php/php_mysql_create_table.asp stored it in a sub folder somewhere safe and added an empty index.php for good measure. I was then able to test that this PHP file (and my SQL script) was working from the browser URL line.

All good so far. On to CRON. Following the above example almost worked. I ended up calling PHP before the path for my *.php file. Otherwise CRON didn't know what to do with the file.

my cron is set to run once per day and looks like this, modified for security.

00 * * * * php mywebsiteurl.com/wp-content/themes/ForteChildTheme/php/DeleteExpiredAssessment.php

For the final testing with CRON I initially set it to run each minute and had email alerts turned on. This quickly confirmed that it was running as planned and I changed it back to once per day.

Hope this helps.

Node.js heap out of memory

For other beginners like me, who didn't find any suitable solution for this error, check the node version installed (x32, x64, x86). I have a 64-bit CPU and I've installed x86 node version, which caused the CALL_AND_RETRY_LAST Allocation failed - JavaScript heap out of memory error.

The specified child already has a parent. You must call removeView() on the child's parent first (Android)

if(tv!= null){
    ((ViewGroup)tv.getParent()).removeView(tv); // <- fix
}

xcopy file, rename, suppress "Does xxx specify a file name..." message

Just go to http://technet.microsoft.com/en-us/library/bb491035.aspx

Here's what the MAIN ISSUE is "... If Destination does not contain an existing directory and does not end with a backslash (), the following message appears: ...

Does destination specify a file name or directory name on the target (F = file, D = directory)?

You can suppress this message by using the /i command-line option, which causes xcopy to assume that the destination is a directory if the source is more than one file or a directory.

Took me a while, but all it takes is RTFM.

Why can't I enter a string in Scanner(System.in), when calling nextLine()-method?

This is a common misunderstanding which leads to confusion if you use the same Scanner for nextLine() right after you used nextInt().

You can either fix the cursor jumping to the next Line by yourself or just use a different scanner for your Integers.

OPTION A: use 2 different scanners

import java.util.Scanner;

class string
{

    public static void main(String a[]){
    int a;
    String s;
    Scanner intscan =new Scanner(System.in);


    System.out.println("enter a no");
    a=intscan.nextInt();
    System.out.println("no is ="+a);


     Scanner textscan=new Scanner(System.in);
    System.out.println("enter a string");
    s=textscan.nextLine();
    System.out.println("string is="+s);
        }
}

OPTION B: just jump to the next Line

class string
{
    public static void main(String a[]){
        int a;
        String s;
        Scanner scan =new Scanner(System.in);

        System.out.println("enter a no");
        a = scan.nextInt();
        System.out.println("no is ="+a);
        scan.nextLine();

        System.out.println("enter a string");
        s = scan.nextLine();
        System.out.println("string is="+s);
    }
}

Java double comparison epsilon

Cents? If you're calculationg money values you really shouldn't use float values. Money is actually countable values. The cents or pennys etc. could be considered the two (or whatever) least significant digits of an integer. You could store, and calculate money values as integers and divide by 100 (e.g. place dot or comma two before the two last digits). Using float's can lead to strange rounding errors...

Anyway, if your epsilon is supposed to define the accuracy, it looks a bit too small (too accurate)...

Get human readable version of file size?

Here is an option using while:

def number_format(n):
   n2, n3 = n, 0
   while n2 >= 1e3:
      n2 /= 1e3
      n3 += 1
   return '%.3f' % n2 + ('', ' k', ' M', ' G')[n3]

s = number_format(9012345678)
print(s == '9.012 G')

https://docs.python.org/reference/compound_stmts.html#while

Android ADB commands to get the device properties

From Linux Terminal:

adb shell getprop | grep "model\|version.sdk\|manufacturer\|hardware\|platform\|revision\|serialno\|product.name\|brand"

From Windows PowerShell:

adb shell 
getprop | grep -e 'model' -e 'version.sdk' -e 'manufacturer' -e 'hardware' -e 'platform' -e 'revision' -e 'serialno' -e 'product.name' -e 'brand'

Sample output for Samsung:

[gsm.version.baseband]: [G900VVRU2BOE1]
[gsm.version.ril-impl]: [Samsung RIL v3.0]
[net.knoxscep.version]: [2.0.1]
[net.knoxsso.version]: [2.1.1]
[net.knoxvpn.version]: [2.2.0]
[persist.service.bdroid.version]: [4.1]
[ro.board.platform]: [msm8974]
[ro.boot.hardware]: [qcom]
[ro.boot.serialno]: [xxxxxx]
[ro.build.version.all_codenames]: [REL]
[ro.build.version.codename]: [REL]
[ro.build.version.incremental]: [G900VVRU2BOE1]
[ro.build.version.release]: [5.0]
[ro.build.version.sdk]: [21]
[ro.build.version.sdl]: [2101]
[ro.com.google.gmsversion]: [5.0_r2]
[ro.config.timaversion]: [3.0]
[ro.hardware]: [qcom]
[ro.opengles.version]: [196108]
[ro.product.brand]: [Verizon]
[ro.product.manufacturer]: [samsung]
[ro.product.model]: [SM-G900V]
[ro.product.name]: [kltevzw]
[ro.revision]: [14]
[ro.serialno]: [e5ce97c7]

Change Active Menu Item on Page Scroll?

Just check my Code and Sniper and demo link :

    // Basice Code keep it 
    $(document).ready(function () {
        $(document).on("scroll", onScroll);

        //smoothscroll
        $('a[href^="#"]').on('click', function (e) {
            e.preventDefault();
            $(document).off("scroll");

            $('a').each(function () {
                $(this).removeClass('active');
            })
            $(this).addClass('active');

            var target = this.hash,
                menu = target;
            $target = $(target);
            $('html, body').stop().animate({
                'scrollTop': $target.offset().top+2
            }, 500, 'swing', function () {
                window.location.hash = target;
                $(document).on("scroll", onScroll);
            });
        });
    });

// Use Your Class or ID For Selection 

    function onScroll(event){
        var scrollPos = $(document).scrollTop();
        $('#menu-center a').each(function () {
            var currLink = $(this);
            var refElement = $(currLink.attr("href"));
            if (refElement.position().top <= scrollPos && refElement.position().top + refElement.height() > scrollPos) {
                $('#menu-center ul li a').removeClass("active");
                currLink.addClass("active");
            }
            else{
                currLink.removeClass("active");
            }
        });
    }

demo live

_x000D_
_x000D_
$(document).ready(function () {_x000D_
    $(document).on("scroll", onScroll);_x000D_
    _x000D_
    //smoothscroll_x000D_
    $('a[href^="#"]').on('click', function (e) {_x000D_
        e.preventDefault();_x000D_
        $(document).off("scroll");_x000D_
        _x000D_
        $('a').each(function () {_x000D_
            $(this).removeClass('active');_x000D_
        })_x000D_
        $(this).addClass('active');_x000D_
      _x000D_
        var target = this.hash,_x000D_
            menu = target;_x000D_
        $target = $(target);_x000D_
        $('html, body').stop().animate({_x000D_
            'scrollTop': $target.offset().top+2_x000D_
        }, 500, 'swing', function () {_x000D_
            window.location.hash = target;_x000D_
            $(document).on("scroll", onScroll);_x000D_
        });_x000D_
    });_x000D_
});_x000D_
_x000D_
function onScroll(event){_x000D_
    var scrollPos = $(document).scrollTop();_x000D_
    $('#menu-center a').each(function () {_x000D_
        var currLink = $(this);_x000D_
        var refElement = $(currLink.attr("href"));_x000D_
        if (refElement.position().top <= scrollPos && refElement.position().top + refElement.height() > scrollPos) {_x000D_
            $('#menu-center ul li a').removeClass("active");_x000D_
            currLink.addClass("active");_x000D_
        }_x000D_
        else{_x000D_
            currLink.removeClass("active");_x000D_
        }_x000D_
    });_x000D_
}
_x000D_
body, html {_x000D_
    margin: 0;_x000D_
    padding: 0;_x000D_
    height: 100%;_x000D_
    width: 100%;_x000D_
}_x000D_
.menu {_x000D_
    width: 100%;_x000D_
    height: 75px;_x000D_
    background-color: rgba(0, 0, 0, 1);_x000D_
    position: fixed;_x000D_
    background-color:rgba(4, 180, 49, 0.6);_x000D_
    -webkit-transition: all 0.4s ease;_x000D_
    -moz-transition: all 0.4s ease;_x000D_
    -o-transition: all 0.4s ease;_x000D_
    transition: all 0.4s ease;_x000D_
}_x000D_
.light-menu {_x000D_
    width: 100%;_x000D_
    height: 75px;_x000D_
    background-color: rgba(255, 255, 255, 1);_x000D_
    position: fixed;_x000D_
    background-color:rgba(4, 180, 49, 0.6);_x000D_
    -webkit-transition: all 0.4s ease;_x000D_
    -moz-transition: all 0.4s ease;_x000D_
    -o-transition: all 0.4s ease;_x000D_
    transition: all 0.4s ease;_x000D_
}_x000D_
#menu-center {_x000D_
    width: 980px;_x000D_
    height: 75px;_x000D_
    margin: 0 auto;_x000D_
}_x000D_
#menu-center ul {_x000D_
    margin: 0 0 0 0;_x000D_
}_x000D_
#menu-center ul li a{_x000D_
  padding: 32px 40px;_x000D_
}_x000D_
#menu-center ul li {_x000D_
    list-style: none;_x000D_
    margin: 0 0 0 -4px;_x000D_
    display: inline;_x000D_
_x000D_
}_x000D_
.active, #menu-center ul li a:hover  {_x000D_
    font-family:'Droid Sans', serif;_x000D_
    font-size: 14px;_x000D_
    color: #fff;_x000D_
    text-decoration: none;_x000D_
    line-height: 50px;_x000D_
 background-color: rgba(0, 0, 0, 0.12);_x000D_
 padding: 32px 40px;_x000D_
_x000D_
}_x000D_
a {_x000D_
    font-family:'Droid Sans', serif;_x000D_
    font-size: 14px;_x000D_
    color: black;_x000D_
    text-decoration: none;_x000D_
    line-height: 72px;_x000D_
}_x000D_
#home {_x000D_
    background-color: #286090;_x000D_
    height: 100vh;_x000D_
    width: 100%;_x000D_
    overflow: hidden;_x000D_
}_x000D_
#portfolio {_x000D_
    background: gray; _x000D_
    height: 100vh;_x000D_
    width: 100%;_x000D_
}_x000D_
#about {_x000D_
    background-color: blue;_x000D_
    height: 100vh;_x000D_
    width: 100%;_x000D_
}_x000D_
#contact {_x000D_
    background-color: rgb(154, 45, 45);_x000D_
    height: 100vh;_x000D_
    width: 100%;_x000D_
}
_x000D_
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>_x000D_
<!-- <div class="container"> --->_x000D_
   <div class="m1 menu">_x000D_
   <div id="menu-center">_x000D_
    <ul>_x000D_
     <li><a class="active" href="#home">Home</a>_x000D_
_x000D_
     </li>_x000D_
     <li><a href="#portfolio">Portfolio</a>_x000D_
_x000D_
     </li>_x000D_
     <li><a href="#about">About</a>_x000D_
_x000D_
     </li>_x000D_
     <li><a href="#contact">Contact</a>_x000D_
_x000D_
     </li>_x000D_
    </ul>_x000D_
   </div>_x000D_
   </div>_x000D_
   <div id="home"></div>_x000D_
   <div id="portfolio"></div>_x000D_
   <div id="about"></div>_x000D_
   <div id="contact"></div>
_x000D_
_x000D_
_x000D_

How to get parameter value for date/time column from empty MaskedTextBox

You're storing the .Text properties of the textboxes directly into the database, this doesn't work. The .Text properties are Strings (i.e. simple text) and not typed as DateTime instances. Do the conversion first, then it will work.

Do this for each date parameter:

Dim bookIssueDate As DateTime = DateTime.ParseExact( txtBookDateIssue.Text, "dd/MM/yyyy", CultureInfo.InvariantCulture ) cmd.Parameters.Add( New OleDbParameter("@Date_Issue", bookIssueDate ) ) 

Note that this code will crash/fail if a user enters an invalid date, e.g. "64/48/9999", I suggest using DateTime.TryParse or DateTime.TryParseExact, but implementing that is an exercise for the reader.

Variable number of arguments in C++?

If you know the range of number of arguments that will be provided, you can always use some function overloading, like

f(int a)
    {int res=a; return res;}
f(int a, int b)
    {int res=a+b; return res;}

and so on...

Django: Redirect to previous page after login

Django's built-in authentication works the way you want.

Their login pages include a next query string which is the page to return to after login.

Look at http://docs.djangoproject.com/en/dev/topics/auth/#django.contrib.auth.decorators.login_required

Entity Framework (EF) Code First Cascade Delete for One-to-Zero-or-One relationship

You will have to use the fluent API to do this.

Try adding the following to your DbContext:

protected override void OnModelCreating(DbModelBuilder modelBuilder)
{   
    modelBuilder.Entity<User>()
        .HasOptional(a => a.UserDetail)
        .WithOptionalDependent()
        .WillCascadeOnDelete(true);
}

Python: Finding differences between elements of a list

In the upcoming Python 3.10 release schedule, with the new pairwise function it's possible to slide through pairs of elements and thus map on rolling pairs:

from itertools import pairwise

[y-x for (x, y) in pairwise([1, 3, 6, 7])]
# [2, 3, 1]

The intermediate result being:

pairwise([1, 3, 6, 7])
# [(1, 3), (3, 6), (6, 7)]

React with ES7: Uncaught TypeError: Cannot read property 'state' of undefined

You have to bind your event handlers to correct context (this):

onChange={this.setAuthorState.bind(this)}

cannot convert 'std::basic_string<char>' to 'const char*' for argument '1' to 'int system(const char*)'

The addition of a string literal with an std::string yields another std::string. system expects a const char*. You can use std::string::c_str() for that:

string name = "john";
string tmp = " quickscan.exe resolution 300 selectscanner jpg showui showprogress filename '"+name+".jpg'"
system(tmp.c_str());

How to count total lines changed by a specific author in a Git repository?

The question asked for information on a specific author, but many of the answers were solutions that returned ranked lists of authors based on their lines of code changed.

This was what I was looking for, but the existing solutions were not quite perfect. In the interest of people that may find this question via Google, I've made some improvements on them and made them into a shell script, which I display below.

There are no dependencies on either Perl or Ruby. Furthermore, whitespace, renames, and line movements are taken into account in the line change count. Just put this into a file and pass your Git repository as the first parameter.

#!/bin/bash
git --git-dir="$1/.git" log > /dev/null 2> /dev/null
if [ $? -eq 128 ]
then
    echo "Not a git repository!"
    exit 128
else
    echo -e "Lines  | Name\nChanged|"
    git --work-tree="$1" --git-dir="$1/.git" ls-files -z |\
    xargs -0n1 git --work-tree="$1" --git-dir="$1/.git" blame -C -M  -w |\
    cut -d'(' -f2 |\
    cut -d2 -f1 |\
    sed -e "s/ \{1,\}$//" |\
    sort |\
    uniq -c |\
    sort -nr
fi

What is thread safe or non-thread safe in PHP?

As per PHP Documentation,

What does thread safety mean when downloading PHP?

Thread Safety means that binary can work in a multithreaded webserver context, such as Apache 2 on Windows. Thread Safety works by creating a local storage copy in each thread, so that the data won't collide with another thread.

So what do I choose? If you choose to run PHP as a CGI binary, then you won't need thread safety, because the binary is invoked at each request. For multithreaded webservers, such as IIS5 and IIS6, you should use the threaded version of PHP.

Following Libraries are not thread safe. They are not recommended for use in a multi-threaded environment.

  • SNMP (Unix)
  • mSQL (Unix)
  • IMAP (Win/Unix)
  • Sybase-CT (Linux, libc5)

Find out a Git branch creator

A branch is nothing but a commit pointer. As such, it doesn't track metadata like "who created me." See for yourself. Try cat .git/refs/heads/<branch> in your repository.

That written, if you're really into tracking this information in your repository, check out branch descriptions. They allow you to attach arbitrary metadata to branches, locally at least.

Also DarVar's answer below is a very clever way to get at this information.

Python - How to concatenate to a string in a for loop?

If you must, this is how you can do it in a for loop:

mylist = ['first', 'second', 'other']
endstring = ''
for s in mylist:
  endstring += s

but you should consider using join():

''.join(mylist)

Why "no projects found to import"?

After a long time finally i found that! Here my Way: File -> New Project -> Android Project From Existing Code -> Browse to your project root directory finish!

Nginx Different Domains on Same IP

Your "listen" directives are wrong. See this page: http://nginx.org/en/docs/http/server_names.html.

They should be

server {
    listen      80;
    server_name www.domain1.com;
    root /var/www/domain1;
}

server {
    listen       80;
    server_name www.domain2.com;
    root /var/www/domain2;
}

Note, I have only included the relevant lines. Everything else looked okay but I just deleted it for clarity. To test it you might want to try serving a text file from each server first before actually serving php. That's why I left the 'root' directive in there.

Build not visible in itunes connect

Check the status of the new build on the "Activity" tab. Once the "Processing" label disappears from the build you should be able to use it.

Create an array of integers property in Objective-C

This should work:

@interface MyClass
{
    int _doubleDigits[10]; 
}

@property(readonly) int *doubleDigits;

@end

@implementation MyClass

- (int *)doubleDigits
{
    return _doubleDigits;
}

@end

Node.js global variables

The other solutions that use the GLOBAL keyword are a nightmare to maintain/readability (+namespace pollution and bugs) when the project gets bigger. I've seen this mistake many times and had the hassle of fixing it.

Use a JavaScript file and then use module exports.

Example:

File globals.js

var Globals = {
    'domain':'www.MrGlobal.com';
}

module.exports = Globals;

Then if you want to use these, use require.

var globals = require('globals'); // << globals.js path
globals.domain // << Domain.

405 method not allowed Web API

For my part my POST handler was of this form:

[HttpPost("{routeParam}")]
public async Task<ActionResult> PostActuality ([FromRoute] int routeParam, [FromBody] PostData data)

I figured out that I had to swap the arguments, that is to say the body data first then the route parameter, as this:

[HttpPost("{routeParam}")]
public async Task<ActionResult> PostActuality ([FromBody] PostData data, [FromRoute] int routeParam)

Playing a MP3 file in a WinForm application

1) The most simple way would be using WMPLib

WMPLib.WindowsMediaPlayer Player;

private void PlayFile(String url)
{
    Player = new WMPLib.WindowsMediaPlayer();
    Player.PlayStateChange += Player_PlayStateChange;
    Player.URL = url;
    Player.controls.play();
}

private void Player_PlayStateChange(int NewState)
{
    if ((WMPLib.WMPPlayState)NewState == WMPLib.WMPPlayState.wmppsStopped)
    {
        //Actions on stop
    }
}

2) Alternatively you can use the open source library NAudio. It can play mp3 files using different methods and actually offers much more than just playing a file.

This is as simple as

using NAudio;
using NAudio.Wave;

IWavePlayer waveOutDevice = new WaveOut();
AudioFileReader audioFileReader = new AudioFileReader("Hadouken! - Ugly.mp3");

waveOutDevice.Init(audioFileReader);
waveOutDevice.Play();

Don't forget to dispose after the stop

waveOutDevice.Stop();
audioFileReader.Dispose();
waveOutDevice.Dispose();

changing source on html5 video tag

Instead of getting the same video player to load new files, why not erase the entire <video> element and recreate it. Most browsers will automatically load it if the src's are correct.

Example (using Prototype):

var vid = new Element('video', { 'autoplay': 'autoplay', 'controls': 'controls' });
var src = new Element('source', { 'src': 'video.ogg', 'type': 'video/ogg' });

vid.update(src);
src.insert({ before: new Element('source', { 'src': 'video.mp4', 'type': 'video/mp4' }) });

$('container_div').update(vid);

How to list only top level directories in Python?

Python 3.4 introduced the pathlib module into the standard library, which provides an object oriented approach to handle filesystem paths:

from pathlib import Path

p = Path('./')
[f for f in p.iterdir() if f.is_dir()]

Excel VBA Run-time error '13' Type mismatch

Thank you guys for all your help! Finally I was able to make it work perfectly thanks to a friend and also you! Here is the final code so you can also see how we solve it.

Thanks again!

Option Explicit

Sub k()

Dim x As Integer, i As Integer, a As Integer
Dim name As String
'name = InputBox("Please insert the name of the sheet")
i = 1
name = "Reserva"
Sheets(name).Cells(4, 57) = Sheets(name).Cells(4, 56)

On Error GoTo fim
x = Sheets(name).Cells(4, 56).Value
Application.Calculation = xlCalculationManual
Do While Not IsEmpty(Sheets(name).Cells(i + 4, 56))
    a = 0
    If Sheets(name).Cells(4 + i, 56) <> x Then
        If Sheets(name).Cells(4 + i, 56) <> 0 Then
            If Sheets(name).Cells(4 + i, 56) = 3 Then
                a = x
                Sheets(name).Cells(4 + i, 57) = Sheets(name).Cells(4 + i, 56) - x
                x = Cells(4 + i, 56) - x
            End If
            Sheets(name).Cells(4 + i, 57) = Sheets(name).Cells(4 + i, 56) - a
            x = Sheets(name).Cells(4 + i, 56) - a
        Else
        Cells(4 + i, 57) = ""
        End If
    Else
    Cells(4 + i, 57) = ""
    End If

i = i + 1
Loop
Application.Calculation = xlCalculationAutomatic
Exit Sub
fim:
MsgBox Err.Description
Application.Calculation = xlCalculationAutomatic
End Sub

Easiest way to loop through a filtered list with VBA?

The SpecialCells Does not actually work as it needs to be continuous. I have solved this by adding a sort funtion in order to sort the data based on the coloumns i need.

Sorry for no comments on the code as i was not planning to share it:

Sub testtt()
    arr = FilterAndGetData(Worksheets("Data").range("A:K"), Array(1, 9), Array("george", "WeeklyCash"), Array(1, 2, 3, 10, 11), 1)
    Debug.Print sms(arr)
End Sub
Function FilterAndGetData(ByVal rng As Variant, ByVal fields As Variant, ByVal criterias As Variant, ByVal colstoreturn As Variant, ByVal headers As Boolean) As Variant
Dim SUset, EAset, CMset
If Application.ScreenUpdating Then Application.ScreenUpdating = False: SUset = False Else SUset = True
If Application.EnableEvents Then Application.EnableEvents = False: EAset = False Else EAset = True
If Application.Calculation = xlCalculationAutomatic Then Application.Calculation = xlCalculationManual: CMset = False Else CMset = True
For Each col In rng.Columns: col.Hidden = False: Next col

Dim oldsheet, scol, ecol, srow, hyesno As String
Dim i, counter As Integer

oldsheet = ActiveSheet.Name


Worksheets(rng.Worksheet.Name).Activate

Worksheets(rng.Worksheet.Name).AutoFilterMode = False

scol = Chr(rng.Column + 64)
ecol = Chr(rng.Columns.Count + rng.Column + 64 - 1)
srow = rng.row

If UBound(fields) - LBound(fields) <> UBound(criterias) - LBound(criterias) Then FilterAndGetData = "Fields&Crit. counts dont match": GoTo done

dd = sortrange(rng, colstoreturn, headers)

For i = LBound(fields) To UBound(fields)
    rng.AutoFilter Field:=CStr(fields(i)), Criteria1:=CStr(criterias(i))
Next i

Dim rngg As Variant

rngg = rng.SpecialCells(xlCellTypeVisible)
Debug.Print ActiveSheet.AutoFilter.range.address
FilterAndGetData = ActiveSheet.AutoFilter.range.SpecialCells(xlCellTypeVisible).Value

For Each row In rng.Rows
    If row.EntireRow.Hidden Then Debug.Print yes
Next row


done:
    'Worksheets("Data").AutoFilterMode = False
    Worksheets(oldsheet).Activate
    If SUset Then Application.ScreenUpdating = True
    If EAset Then Application.EnableEvents = True
    If CMset Then Application.Calculation = xlCalculationAutomatic
End Function
Function sortrange(ByVal rng As Variant, ByVal colnumbers As Variant, ByVal headers As Boolean)

    Dim SUset, EAset, CMset
    If Application.ScreenUpdating Then Application.ScreenUpdating = False: SUset = False Else SUset = True
    If Application.EnableEvents Then Application.EnableEvents = False: EAset = False Else EAset = True
    If Application.Calculation = xlCalculationAutomatic Then Application.Calculation = xlCalculationManual: CMset = False Else CMset = True
    For Each col In rng.Columns: col.Hidden = False: Next col

    Dim oldsheet, scol, srow, sortcol, hyesno As String
    Dim i, counter As Integer
    oldsheet = ActiveSheet.Name
    Worksheets(rng.Worksheet.Name).Activate
    Worksheets(rng.Worksheet.Name).AutoFilterMode = False
    scol = rng.Column
    srow = rng.row

    If headers Then hyesno = xlYes Else hyesno = xlNo

    For i = LBound(colnumbers) To UBound(colnumbers)
        rng.Sort key1:=range(Chr(scol + colnumbers(i) + 63) + CStr(srow)), order1:=xlAscending, Header:=hyesno
    Next i
    sortrange = "123"
done:
    Worksheets(oldsheet).Activate
    If SUset Then Application.ScreenUpdating = True
    If EAset Then Application.EnableEvents = True
    If CMset Then Application.Calculation = xlCalculationAutomatic
End Function

In Typescript, what is the ! (exclamation mark / bang) operator when dereferencing a member?

Louis' answer is great, but I thought I would try to sum it up succinctly:

The bang operator tells the compiler to temporarily relax the "not null" constraint that it might otherwise demand. It says to the compiler: "As the developer, I know better than you that this variable cannot be null right now".

Angular2 get clicked element id

You can retrieve the value of an attribute by its name, enabling you to get the value of a custom attribute such as an attribute from a Directive:

<button (click)="toggle($event)" id="btn1" myCustomAttribute="somevalue"></button>


toggle( event: Event ) {
  const eventTarget: Element = event.target as Element;
  const elementId: string = eventTarget.id;
  const attribVal: string = eventTarget.attributes['myCustomAttribute'].nodeValue;
}

What is difference between MVC, MVP & MVVM design pattern in terms of coding c#

Some basic differences can be written in short:

MVC:

Traditional MVC is where there is a

  1. Model: Acts as the model for data
  2. View : Deals with the view to the user which can be the UI
  3. Controller: Controls the interaction between Model and View, where view calls the controller to update model. View can call multiple controllers if needed.

MVP:

Similar to traditional MVC but Controller is replaced by Presenter. But the Presenter, unlike Controller is responsible for changing the view as well. The view usually does not call the presenter.

MVVM

The difference here is the presence of View Model. It is kind of an implementation of Observer Design Pattern, where changes in the model are represented in the view as well, by the VM. Eg: If a slider is changed, not only the model is updated but the data which may be a text, that is displayed in the view is updated as well. So there is a two-way data binding.

Can a table have two foreign keys?

The foreign keys in your schema (on Account_Name and Account_Type) do not require any special treatment or syntax. Just declare two separate foreign keys on the Customer table. They certainly don't constitute a composite key in any meaningful sense of the word.

There are numerous other problems with this schema, but I'll just point out that it isn't generally a good idea to build a primary key out of multiple unique columns, or columns in which one is functionally dependent on another. It appears that at least one of these cases applies to the ID and Name columns in the Customer table. This allows you to create two rows with the same ID (different name), which I'm guessing you don't want to allow.

Add & delete view from Layout

I am removing view using start and count Method, i have added 3 view in linear Layout.

view.removeViews(0, 3);

Uncaught Error: Invariant Violation: Element type is invalid: expected a string (for built-in components) or a class/function but got: object

I got this by doing import App from './app/'; expecting it to import ./app/index.js, but it instead imported ./app.json.

How to get height of entire document with JavaScript?

This is a really old question, and thus, has many outdated answers. As of 2020 all major browsers have adhered to the standard.

Answer for 2020:

document.body.scrollHeight

Edit: the above doesn't take margins on the <body> tag into account. If your body has margins, use:

document.documentElement.scrollHeight

addEventListener, "change" and option selection

The problem is that you used the select option, this is where you went wrong. Select signifies that a textbox or textArea has a focus. What you need to do is use change. "Fires when a new choice is made in a select element", also used like blur when moving away from a textbox or textArea.

function start(){
      document.getElementById("activitySelector").addEventListener("change", addActivityItem, false);
      }

function addActivityItem(){
      //option is selected
      alert("yeah");
}

window.addEventListener("load", start, false);

Align button at the bottom of div using CSS

You can use position:absolute; to absolutely position an element within a parent div. When using position:absolute; the element will be positioned absolutely from the first positioned parent div, if it can't find one it will position absolutely from the window so you will need to make sure the content div is positioned.

To make the content div positioned, all position values that aren't static will work, but relative is the easiest since it doesn't change the divs positioning by itself.

So add position:relative; to the content div, remove the float from the button and add the following css to the button:

position: absolute;
right:    0;
bottom:   0;

Insert some string into given string at given index in Python

I know it's malapropos, but IMHO easy way is:

def insert (source_str, insert_str, pos):
    return source_str[:pos]+insert_str+source_str[pos:]

Android changing Floating Action Button color

just use,

app:backgroundTint="@color/colorPrimary"

dont use,

android:backgroundTint="@color/colorPrimary"

How to change default text color using custom theme?

    <style name="Mytext" parent="@android:style/TextAppearance.Medium"> 
    <item name="android:textSize">20sp</item> 
    <item name="android:textColor">@color/white</item> 
    <item name="android:textStyle">bold</item>
    <item name="android:typeface">sans</item>
</style>

try this one ...

Count specific character occurrences in a string

I think this would be the easiest:

Public Function CountCharacter(ByVal value As String, ByVal ch As Char) As Integer
  Return len(value) - len(replace(value, ch, ""))
End Function

Is there a decorator to simply cache function return values?

If you are using Django and want to cache views, see Nikhil Kumar's answer.


But if you want to cache ANY function results, you can use django-cache-utils.

It reuses Django caches and provides easy to use cached decorator:

from cache_utils.decorators import cached

@cached(60)
def foo(x, y=0):
    print 'foo is called'
    return x+y

Install apk without downloading

For this your android application must have uploaded into the android market. when you upload it on the android market then use the following code to open the market with your android application.

    Intent intent = new Intent(Intent.ACTION_VIEW,Uri.parse("market://details?id=<packagename>"));
startActivity(intent);

If you want it to download and install from your own server then use the following code

Intent intent = new Intent(Intent.ACTION_VIEW,Uri.parse("http://www.example.com/sample/test.apk"));
    startActivity(intent);

Invalid default value for 'dateAdded'

I have mysql version 5.6.27 on my LEMP and CURRENT_TIMESTAMP as default value works fine.

How to get the size of a varchar[n] field in one SQL statement?

On SQL Server specifically:

SELECT DATALENGTH(Remarks) AS FIELDSIZE FROM mytable

Documentation

jQuery Date Picker - disable past dates

Use the "minDate" option to restrict the earliest allowed date. The value "0" means today (0 days from today):

    $(document).ready(function () {
        $("#txtdate").datepicker({
            minDate: 0,
            // ...
        });
    });

Docs here: http://api.jqueryui.com/datepicker/#option-minDate

How to verify an XPath expression in Chrome Developers tool or Firefox's Firebug?

Another option to check your xpath is to use selenium IDE.

  1. Install Firefox Selenium IDE
  2. Open your application in FireFox and open IDE
  3. In IDE, on a new line, paste your xpath to the target and click Find. The corresponding element would be highlighted in your application

Selenium IDE

Installing Numpy on 64bit Windows 7 with Python 2.7.3

You may also try this, anaconda http://continuum.io/downloads

But you need to modify your environment variable PATH, so that the anaconda folder is before the original Python folder.

select count(*) from table of mysql in php

You can as well use this and upgrade to mysqli_ (stop using mysql_* extension...)

$result = mysqli_query($conn, "SELECT COUNT(*) AS `count` FROM `Students`");
$row = mysqli_fetch_array($result);
$count = $row['count'];
echo $count;

How to disable text selection using jQuery?

I think this code works on all browsers and requires the least overhead. It's really a hybrid of all the above answers. Let me know if you find a bug!

Add CSS:

.no_select { user-select: none; -o-user-select: none; -moz-user-select: none; -khtml-user-select: none; -webkit-user-select: none; -ms-user-select:none;}

Add jQuery:

(function($){
    $.fn.disableSelection = function() 
    {       
        $(this).addClass('no_select');              
        if($.browser.msie)
        {
            $(this).attr('unselectable', 'on').on('selectstart', false);            
        }
    return this;            
};
})(jQuery);

Optional: To disable selection for all children elements as well, you can change the IE block to:

$(this).each(function() {
    $(this).attr('unselectable','on')
    .bind('selectstart',function(){ return false; });
});

Usage:

$('.someclasshere').disableSelection();

Get button click inside UITableViewCell

Instead of playing with tags, I took different approach. Made delegate for my subclass of UITableViewCell(OptionButtonsCell) and added an indexPath var. From my button in storyboard I connected @IBAction to the OptionButtonsCell and there I send delegate method with the right indexPath to anyone interested. In cell for index path I set current indexPath and it works :)

Let the code speak for itself:

Swift 3 Xcode 8

OptionButtonsTableViewCell.swift

import UIKit
protocol OptionButtonsDelegate{
    func closeFriendsTapped(at index:IndexPath)
}
class OptionButtonsTableViewCell: UITableViewCell {
    var delegate:OptionButtonsDelegate!
    @IBOutlet weak var closeFriendsBtn: UIButton!
    var indexPath:IndexPath!
    @IBAction func closeFriendsAction(_ sender: UIButton) {
        self.delegate?.closeFriendsTapped(at: indexPath)
    }
}

MyTableViewController.swift

class MyTableViewController: UIViewController, UITableViewDelegate, UITableViewDataSource, OptionButtonsDelegate {...

func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
    let cell = tableView.dequeueReusableCell(withIdentifier: "optionCell") as! OptionButtonsTableViewCell
    cell.delegate = self
    cell.indexPath = indexPath
    return cell   
}

func closeFriendsTapped(at index: IndexPath) {
     print("button tapped at index:\(index)")
}

Delete dynamically-generated table row using jQuery

A simple solution is encapsulate code of button event in a function, and call it when you add TRs too:

 var i = 1;
$("#addbutton").click(function() {
  $("table tr:first").clone().find("input").each(function() {
    $(this).val('').attr({
      'id': function(_, id) {return id + i },
      'name': function(_, name) { return name + i },
      'value': ''               
    });
  }).end().appendTo("table");
  i++;

  applyRemoveEvent();  
});


function applyRemoveEvent(){
    $('button.removebutton').on('click',function() {
        alert("aa");
      $(this).closest( 'tr').remove();
      return false;
    });
};

applyRemoveEvent();

http://jsfiddle.net/Z7fG7/2/

Loop over html table and get checked checkboxes (JQuery)

Use this instead:

$('#save').click(function () {
    $('#mytable').find('input[type="checkbox"]:checked') //...
});

Let me explain you what the selector does: input[type="checkbox"] means that this will match each <input /> with type attribute type equals to checkbox After that: :checked will match all checked checkboxes.

You can loop over these checkboxes with:

$('#save').click(function () {
    $('#mytable').find('input[type="checkbox"]:checked').each(function () {
       //this is the current checkbox
    });
});

Here is demo in JSFiddle.


And here is a demo which solves exactly your problem http://jsfiddle.net/DuE8K/1/.

$('#save').click(function () {
    $('#mytable').find('tr').each(function () {
        var row = $(this);
        if (row.find('input[type="checkbox"]').is(':checked') &&
            row.find('textarea').val().length <= 0) {
            alert('You must fill the text area!');
        }
    });
});

Joining three tables using MySQL

For normalize form

select e1.name as 'Manager', e2.name as 'Staff'
from employee e1 
left join manage m on m.mid = e1.id
left join employee e2 on m.eid = e2.id

Why does writeObject throw java.io.NotSerializableException and how do I fix it?

The fields of your object have in turn their fields, some of which do not implement Serializable. In your case the offending class is TransformGroup. How to solve it?

  • if the class is yours, make it Serializable
  • if the class is 3rd party, but you don't need it in the serialized form, mark the field as transient
  • if you need its data and it's third party, consider other means of serialization, like JSON, XML, BSON, MessagePack, etc. where you can get 3rd party objects serialized without modifying their definitions.

Getting the PublicKeyToken of .Net assemblies

If the library is included in the VS project, you can check .cproj file, e.g.:

<ItemGroup>
    <Reference Include="Microsoft.Dynamic, Version=1.1.0.20, Culture=neutral, PublicKeyToken=7f709c5b713576e1, processorArchitecture=MSIL">
...

How to build a 'release' APK in Android Studio?

AndroidStudio is alpha version for now. So you have to edit gradle build script files by yourself. Add next lines to your build.gradle

android {

    signingConfigs {

        release {

            storeFile file('android.keystore')
            storePassword "pwd"
            keyAlias "alias"
            keyPassword "pwd"
        }
    }

    buildTypes {

       release {

           signingConfig signingConfigs.release
       }
    }
}

To actually run your application at emulator or device run gradle installDebug or gradle installRelease.

You can create helloworld project from AndroidStudio wizard to see what structure of gradle files is needed. Or export gradle files from working eclipse project. Also this series of articles are helpfull http://blog.stylingandroid.com/archives/1872#more-1872

UIDevice uniqueIdentifier deprecated - What to do now?

I would also suggest changing over from uniqueIdentifier to this open source library (2 simple categories really) that utilize the device’s MAC Address along with the App Bundle Identifier to generate a unique ID in your applications that can be used as a UDID replacement.

Keep in mind that unlike the UDID this number will be different for every app.

You simply need to import the included NSString and UIDevice categories and call [[UIDevice currentDevice] uniqueDeviceIdentifier] like so:

#import "UIDevice+IdentifierAddition.h"
#import "NSString+MD5Addition.h"
NSString *iosFiveUDID = [[UIDevice currentDevice] uniqueDeviceIdentifier]

You can find it on Github here:

UIDevice with UniqueIdentifier for iOS 5


Here are the categories (just the .m files - check the github project for the headers):

UIDevice+IdentifierAddition.m

#import "UIDevice+IdentifierAddition.h"
#import "NSString+MD5Addition.h"

#include <sys/socket.h> // Per msqr
#include <sys/sysctl.h>
#include <net/if.h>
#include <net/if_dl.h>

@interface UIDevice(Private)

- (NSString *) macaddress;

@end

@implementation UIDevice (IdentifierAddition)

////////////////////////////////////////////////////////////////////////////////
#pragma mark -
#pragma mark Private Methods

// Return the local MAC addy
// Courtesy of FreeBSD hackers email list
// Accidentally munged during previous update. Fixed thanks to erica sadun & mlamb.
- (NSString *) macaddress{
    
    int                 mib[6];
    size_t              len;
    char                *buf;
    unsigned char       *ptr;
    struct if_msghdr    *ifm;
    struct sockaddr_dl  *sdl;
    
    mib[0] = CTL_NET;
    mib[1] = AF_ROUTE;
    mib[2] = 0;
    mib[3] = AF_LINK;
    mib[4] = NET_RT_IFLIST;
    
    if ((mib[5] = if_nametoindex("en0")) == 0) {
        printf("Error: if_nametoindex error\n");
        return NULL;
    }
    
    if (sysctl(mib, 6, NULL, &len, NULL, 0) < 0) {
        printf("Error: sysctl, take 1\n");
        return NULL;
    }
    
    if ((buf = malloc(len)) == NULL) {
        printf("Could not allocate memory. error!\n");
        return NULL;
    }
    
    if (sysctl(mib, 6, buf, &len, NULL, 0) < 0) {
        printf("Error: sysctl, take 2");
        return NULL;
    }
    
    ifm = (struct if_msghdr *)buf;
    sdl = (struct sockaddr_dl *)(ifm + 1);
    ptr = (unsigned char *)LLADDR(sdl);
    NSString *outstring = [NSString stringWithFormat:@"%02X:%02X:%02X:%02X:%02X:%02X", 
                           *ptr, *(ptr+1), *(ptr+2), *(ptr+3), *(ptr+4), *(ptr+5)];
    free(buf);
    
    return outstring;
}

////////////////////////////////////////////////////////////////////////////////
#pragma mark -
#pragma mark Public Methods

- (NSString *) uniqueDeviceIdentifier{
    NSString *macaddress = [[UIDevice currentDevice] macaddress];
    NSString *bundleIdentifier = [[NSBundle mainBundle] bundleIdentifier];  
    NSString *stringToHash = [NSString stringWithFormat:@"%@%@",macaddress,bundleIdentifier];
    NSString *uniqueIdentifier = [stringToHash stringFromMD5];  
    return uniqueIdentifier;
}

- (NSString *) uniqueGlobalDeviceIdentifier{
    NSString *macaddress = [[UIDevice currentDevice] macaddress];
    NSString *uniqueIdentifier = [macaddress stringFromMD5];    
    return uniqueIdentifier;
}

@end

NSString+MD5Addition.m:

#import "NSString+MD5Addition.h"
#import <CommonCrypto/CommonDigest.h>

@implementation NSString(MD5Addition)

- (NSString *) stringFromMD5{
    
    if(self == nil || [self length] == 0)
        return nil;
    
    const char *value = [self UTF8String];
    
    unsigned char outputBuffer[CC_MD5_DIGEST_LENGTH];
    CC_MD5(value, strlen(value), outputBuffer);
    
    NSMutableString *outputString = [[NSMutableString alloc] initWithCapacity:CC_MD5_DIGEST_LENGTH * 2];
    for(NSInteger count = 0; count < CC_MD5_DIGEST_LENGTH; count++){
        [outputString appendFormat:@"%02x",outputBuffer[count]];
    }
    return [outputString autorelease];
}

@end

Is there an Eclipse plugin to run system shell in the Console?

Simply create a new external tool configuration (from Eclipse Run -> External Tools)

for example - To open Cygwin terminal on the current resource directory:

Location:

C:\cygwin\bin\mintty.exe

Working Directory:

${container_loc}

Arguments:

-i /Cygwin-Terminal.ico  
-"cygpath -p '${container_loc}' | xargs cd"

How do I convert a Python program to a runnable .exe Windows program?

There is another way to convert Python scripts to .exe files. You can compile Python programs into C++ programs, which can be natively compiled just like any other C++ program.

How to pass multiple parameters to a get method in ASP.NET Core

To add some more detail about the overloading that you asked about in your comment after another answer, here is a summary. The comments in the ApiController show which action will be called with each GET query:

public class ValuesController : ApiController
{
    // EXPLANATION: See the view for the buttons which call these WebApi actions. For WebApi controllers, 
    //          there can only be one action for a given HTTP verb (GET, POST, etc) which has the same method signature, (even if the param names differ) so
    //          you can't have Get(string height) and Get(string width), but you can have Get(int height) and Get(string width).
    //          It isn't a particularly good idea to do that, but it is true. The key names in the query string must match the
    //          parameter names in the action, and the match is NOT case sensitive. This demo app allows you to test each of these
    //          rules, as follows:
    // 
    // When you send an HTTP GET request with no parameters (/api/values) then the Get() action will be called.
    // When you send an HTTP GET request with a height parameter (/api/values?height=5) then the Get(int height) action will be called.
    // When you send an HTTP GET request with a width parameter (/api/values?width=8) then the Get(string width) action will be called.
    // When you send an HTTP GET request with height and width parameters (/api/values?height=3&width=7) then the 
    //          Get(string height, string width) action will be called.
    // When you send an HTTP GET request with a depth parameter (/api/values?depth=2) then the Get() action will be called
    //          and the depth parameter will be obtained from Request.GetQueryNameValuePairs().
    // When you send an HTTP GET request with height and depth parameters (/api/values?height=4&depth=5) then the Get(int height) 
    //          action will be called, and the depth parameter would need to be obtained from Request.GetQueryNameValuePairs().
    // When you send an HTTP GET request with width and depth parameters (/api/values?width=3&depth=5) then the Get(string width) 
    //          action will be called, and the depth parameter would need to be obtained from Request.GetQueryNameValuePairs().
    // When you send an HTTP GET request with height, width and depth parameters (/api/values?height=7&width=2&depth=9) then the 
    //          Get(string height, string width) action will be called, and the depth parameter would need to be obtained from 
    //          Request.GetQueryNameValuePairs().
    // When you send an HTTP GET request with a width parameter, but with the first letter of the parameter capitalized (/api/values?Width=8) 
    //          then the Get(string width) action will be called because the case does NOT matter.
    // NOTE: If you were to uncomment the Get(string height) action below, then you would get an error about there already being  
    //          a member named Get with the same parameter types. The same goes for Get(int id).
    //
    // ANOTHER NOTE: Using the nullable operator (e.g. string? paramName) you can make optional parameters. It would work better to
    //          demonstrate this in another ApiController, since using nullable params and having a lot of signatures is a recipe
    //          for confusion.

    // GET api/values
    public IEnumerable<string> Get()
    {
        return Request.GetQueryNameValuePairs().Select(pair => "Get() => " + pair.Key + ": " + pair.Value);
        //return new string[] { "value1", "value2" };
    }

    //// GET api/values/5
    //public IEnumerable<string> Get(int id)
    //{
    //    return new string[] { "Get(height) => height: " + id };
    //}

    // GET api/values?height=5
    public IEnumerable<string> Get(int height) // int id)
    {
        return new string[] { "Get(height) => height: " + height };
    }

    // GET api/values?height=3
    public IEnumerable<string> Get(string height)
    {
        return new string[] { "Get(height) => height: " + height };
    }

    //// GET api/values?width=3
    //public IEnumerable<string> Get(string width)
    //{
    //    return new string[] { "Get(width) => width: " + width };
    //}

    // GET api/values?height=4&width=3
    public IEnumerable<string> Get(string height, string width)
    {
        return new string[] { "Get(height, width) => height: " + height + ", width: " + width };
    }
}

You would only need a single route for this, in case you wondered:

    config.Routes.MapHttpRoute(
        name: "DefaultApi",
        routeTemplate: "api/{controller}/{id}",
        defaults: new { id = RouteParameter.Optional }
    );

and you could test it all with this MVC view, or something simlar. Yes, I know you aren't supposed to mix JavaScript with markup and I'm not using bootstrap like you would normally, but this is for demo purposes only.

<div class="jumbotron">
    <h1>Multiple parameters test</h1>
    <p class="lead">Click a link below, which will send an HTTP GET request with parameters to a WebAPI controller.</p>
</div>
<script language="javascript">
    function passNothing() {
        $.get("/api/values", function (data) { alert(data); });
    }

    function passHeight(height) {
        $.get("/api/values?height=" + height, function (data) { alert(data); });
    }

    function passWidth(width) {
        $.get("/api/values?width=" + width, function (data) { alert(data); });
    }

    function passHeightAndWidth(height, width) {
        $.get("/api/values?height=" + height + "&width=" + width, function (data) { alert(data); });
    }

    function passDepth(depth) {
        $.get("/api/values?depth=" + depth, function (data) { alert(data); });
    }

    function passHeightAndDepth(height, depth) {
        $.get("/api/values?height=" + height + "&depth=" + depth, function (data) { alert(data); });
    }

    function passWidthAndDepth(width, depth) {
        $.get("/api/values?width=" + width + "&depth=" + depth, function (data) { alert(data); });
    }

    function passHeightWidthAndDepth(height, width, depth) {
        $.get("/api/values?height=" + height + "&width=" + width + "&depth=" + depth, function (data) { alert(data); });
    }

    function passWidthWithPascalCase(width) {
        $.get("/api/values?Width=" + width, function (data) { alert(data); });
    }
</script>
<div class="row">
    <button class="btn" onclick="passNothing();">Pass Nothing</button>
    <button class="btn" onclick="passHeight(5);">Pass Height of 5</button>
    <button class="btn" onclick="passWidth(8);">Pass Width of 8</button>
    <button class="btn" onclick="passHeightAndWidth(3, 7);">Pass Height of 3 and Width of 7</button>
    <button class="btn" onclick="passDepth(2);">Pass Depth of 2</button>
    <button class="btn" onclick="passHeightAndDepth(4, 5);">Pass Height of 4 and Depth of 5</button>
    <button class="btn" onclick="passWidthAndDepth(3, 5);">Pass Width of 3 and Depth of 5</button>
    <button class="btn" onclick="passHeightWidthAndDepth(7, 2, 9);">Pass Height of 7, Width of 2 and Depth of 9</button>
    <button class="btn" onclick="passHeightWidthAndDepth(7, 2, 9);">Pass Height of 7, Width of 2 and Depth of 9</button>
    <button class="btn" onclick="passWidthWithPascalCase(8);">Pass Width of 8, but with Pascal case</button>
</div>

Is it possible to have empty RequestParam values use the defaultValue?

You can keep primitive type by setting default value, in the your case just add "required = false" property:

@RequestParam(value = "i", required = false, defaultValue = "10") int i

P.S. This page from Spring documentation might be useful: Annotation Type RequestParam

MySQL Job failed to start

To help others who do not have a full disk to troubleshoot this problem, first inspect your error log (for me the path is given in my /etc/mysql/my.cnf file):

tail /var/log/mysql/error.log

My problem turned out to be a new IP address allocated after some network router reconfiguration, so I needed to change the bind-address variable.

What is the main purpose of setTag() getTag() methods of View?

Unlike IDs, tags are not used to identify views. Tags are essentially an extra piece of information that can be associated with a view. They are most often used as a convenience to store data related to views in the views themselves rather than by putting them in a separate structure.

Reference: http://developer.android.com/reference/android/view/View.html

Command line .cmd/.bat script, how to get directory of running script

This is equivalent to the path of the script:

%~dp0

This uses the batch parameter extension syntax. Parameter 0 is always the script itself.

If your script is stored at C:\example\script.bat, then %~dp0 evaluates to C:\example\.

ss64.com has more information about the parameter extension syntax. Here is the relevant excerpt:

You can get the value of any parameter using a % followed by it's numerical position on the command line.

[...]

When a parameter is used to supply a filename then the following extended syntax can be applied:

[...]

%~d1 Expand %1 to a Drive letter only - C:

[...]

%~p1 Expand %1 to a Path only e.g. \utils\ this includes a trailing \ which may be interpreted as an escape character by some commands.

[...]

The modifiers above can be combined:

%~dp1 Expand %1 to a drive letter and path only

[...]

You can get the pathname of the batch script itself with %0, parameter extensions can be applied to this so %~dp0 will return the Drive and Path to the batch script e.g. W:\scripts\

Check last modified date of file in C#

Be aware that the function File.GetLastWriteTime does not always work as expected, the values are sometimes not instantaneously updated by the OS. You may get an old Timestamp, even if the file has been modified right before.

The behaviour may vary between OS versions. For example, this unit test worked well every time on my developer machine, but it always fails on our build server.

  [TestMethod]
  public void TestLastModifiedTimeStamps()
  {
     var tempFile = Path.GetTempFileName();
     var lastModified = File.GetLastWriteTime(tempFile);
     using (new FileStream(tempFile, FileMode.Create, FileAccess.Write, FileShare.None))
     {

     }
     Assert.AreNotEqual(lastModified, File.GetLastWriteTime(tempFile));
  }

See File.GetLastWriteTime seems to be returning 'out of date' value

Your options:

a) live with the occasional omissions.

b) Build up an active component realising the observer pattern (eg. a tcp server client structure), communicating the changes directly instead of writing / reading files. Fast and flexible, but another dependency and a possible point of failure (and some work, of course).

c) Ensure the signalling process by replacing the content of a dedicated signal file that other processes regularly read. It´s not that smart as it´s a polling procedure and has a greater overhead than calling File.GetLastWriteTime, but if not checking the content from too many places too often, it will do the work.

/// <summary>
/// type to set signals or check for them using a central file 
/// </summary>
public class FileSignal
{
    /// <summary>
    /// path to the central file for signal control
    /// </summary>
    public string FilePath { get; private set; }

    /// <summary>
    /// numbers of retries when not able to retrieve (exclusive) file access
    /// </summary>
    public int MaxCollisions { get; private set; }

    /// <summary>
    /// timespan to wait until next try
    /// </summary>
    public TimeSpan SleepOnCollisionInterval { get; private set; }

    /// <summary>
    /// Timestamp of the last signal
    /// </summary>
    public DateTime LastSignal { get; private set; }

    /// <summary>
    /// constructor
    /// </summary>
    /// <param name="filePath">path to the central file for signal control</param>
    /// <param name="maxCollisions">numbers of retries when not able to retrieve (exclusive) file access</param>
    /// <param name="sleepOnCollisionInterval">timespan to wait until next try </param>
    public FileSignal(string filePath, int maxCollisions, TimeSpan sleepOnCollisionInterval)
    {
        FilePath = filePath;
        MaxCollisions = maxCollisions;
        SleepOnCollisionInterval = sleepOnCollisionInterval;
        LastSignal = GetSignalTimeStamp();
    }

    /// <summary>
    /// constructor using a default value of 50 ms for sleepOnCollisionInterval
    /// </summary>
    /// <param name="filePath">path to the central file for signal control</param>
    /// <param name="maxCollisions">numbers of retries when not able to retrieve (exclusive) file access</param>        
    public FileSignal(string filePath, int maxCollisions): this (filePath, maxCollisions, TimeSpan.FromMilliseconds(50))
    {
    }

    /// <summary>
    /// constructor using a default value of 50 ms for sleepOnCollisionInterval and a default value of 10 for maxCollisions
    /// </summary>
    /// <param name="filePath">path to the central file for signal control</param>        
    public FileSignal(string filePath) : this(filePath, 10)
    {
    }

    private Stream GetFileStream(FileAccess fileAccess)
    {
        var i = 0;
        while (true)
        {
            try
            {
                return new FileStream(FilePath, FileMode.Create, fileAccess, FileShare.None);
            }
            catch (Exception e)
            {
                i++;
                if (i >= MaxCollisions)
                {
                    throw e;
                }
                Thread.Sleep(SleepOnCollisionInterval);
            };
        };
    }

    private DateTime GetSignalTimeStamp()
    {
        if (!File.Exists(FilePath))
        {
            return DateTime.MinValue;
        }
        using (var stream = new FileStream(FilePath, FileMode.Open, FileAccess.Read, FileShare.None))
        {
            if(stream.Length == 0)
            {
                return DateTime.MinValue;
            }
            using (var reader = new BinaryReader(stream))
            {
                return DateTime.FromBinary(reader.ReadInt64());
            };                
        }
    }

    /// <summary>
    /// overwrites the existing central file and writes the current time into it.
    /// </summary>
    public void Signal()
    {
        LastSignal = DateTime.Now;
        using (var stream = new FileStream(FilePath, FileMode.Create, FileAccess.Write, FileShare.None))
        {
            using (var writer = new BinaryWriter(stream))
            {
                writer.Write(LastSignal.ToBinary());
            }
        }
    }

    /// <summary>
    /// returns true if the file signal has changed, otherwise false.
    /// </summary>        
    public bool CheckIfSignalled()
    {
        var signal = GetSignalTimeStamp();
        var signalTimestampChanged = LastSignal != signal;
        LastSignal = signal;
        return signalTimestampChanged;
    }
}

Some tests for it:

    [TestMethod]
    public void TestSignal()
    {
        var fileSignal = new FileSignal(Path.GetTempFileName());
        var fileSignal2 = new FileSignal(fileSignal.FilePath);
        Assert.IsFalse(fileSignal.CheckIfSignalled());
        Assert.IsFalse(fileSignal2.CheckIfSignalled());
        Assert.AreEqual(fileSignal.LastSignal, fileSignal2.LastSignal);
        fileSignal.Signal();
        Assert.IsFalse(fileSignal.CheckIfSignalled());
        Assert.AreNotEqual(fileSignal.LastSignal, fileSignal2.LastSignal);
        Assert.IsTrue(fileSignal2.CheckIfSignalled());
        Assert.AreEqual(fileSignal.LastSignal, fileSignal2.LastSignal);
        Assert.IsFalse(fileSignal2.CheckIfSignalled());
    }

How do I create directory if it doesn't exist to create a file?

You can use following code

  DirectoryInfo di = Directory.CreateDirectory(path);

How to store JSON object in SQLite database

https://github.com/app-z/Json-to-SQLite

At first generate Plain Old Java Objects from JSON http://www.jsonschema2pojo.org/

Main method

void createDb(String dbName, String tableName, List dataList, Field[] fields){ ...

Fields name will create dynamically

C++ create string of text and variables

In C++11 you can use std::to_string:

std::string var = "sometext" + std::to_string(somevar) + "sometext" + std::to_string(somevar);  

What is the difference between SQL, PL-SQL and T-SQL?

1. SQL or Structured Query Language was developed by IBM for their product "System R".

Later ANSI made it as a Standard on which all Query Languages are based upon and have extended this to create their own DataBase Query Language suits. The first standard was SQL-86 and latest being SQL:2016

2. T-SQL or Transact-SQL was developed by Sybase and later co-owned by Microsoft SQL Server.

3. PL/SQL or Procedural Language/SQL was Oracle Database, known as "Relation Software" that time.

I've documented this in my blog post.

Android check permission for LocationManager

With Android API level (23), we are required to check for permissions. https://developer.android.com/training/permissions/requesting.html

I had your same problem, but the following worked for me and I am able to retrieve Location data successfully:

(1) Ensure you have your permissions listed in the Manifest:

<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION"/>

(2) Ensure you request permissions from the user:

if ( ContextCompat.checkSelfPermission( this, android.Manifest.permission.ACCESS_COARSE_LOCATION ) != PackageManager.PERMISSION_GRANTED ) {

            ActivityCompat.requestPermissions( this, new String[] {  android.Manifest.permission.ACCESS_COARSE_LOCATION  },
                                                LocationService.MY_PERMISSION_ACCESS_COURSE_LOCATION );
        }

(3) Ensure you use ContextCompat as this has compatibility with older API levels.

(4) In your location service, or class that initializes your LocationManager and gets the last known location, we need to check the permissions:

if ( Build.VERSION.SDK_INT >= 23 &&
             ContextCompat.checkSelfPermission( context, android.Manifest.permission.ACCESS_FINE_LOCATION ) != PackageManager.PERMISSION_GRANTED &&
             ContextCompat.checkSelfPermission( context, android.Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
            return  ;
        }

(5) This approach only worked for me after I included @TargetApi(23) at the top of my initLocationService method.

(6) I also added this to my gradle build:

compile 'com.android.support:support-v4:23.0.1'

Here is my LocationService for reference:

public class LocationService implements LocationListener  {

    //The minimum distance to change updates in meters
    private static final long MIN_DISTANCE_CHANGE_FOR_UPDATES = 0; // 10 meters

    //The minimum time between updates in milliseconds
    private static final long MIN_TIME_BW_UPDATES = 0;//1000 * 60 * 1; // 1 minute

    private final static boolean forceNetwork = false;

    private static LocationService instance = null;

    private LocationManager locationManager;
    public Location location;
    public double longitude;
    public double latitude; 


    /**
     * Singleton implementation
     * @return
     */
    public static LocationService getLocationManager(Context context)     {
        if (instance == null) {
            instance = new LocationService(context);
        }
        return instance;
    }

    /**
     * Local constructor
     */
    private LocationService( Context context )     {

        initLocationService(context); 
        LogService.log("LocationService created");
    }



    /**
     * Sets up location service after permissions is granted
     */
    @TargetApi(23)
    private void initLocationService(Context context) {


        if ( Build.VERSION.SDK_INT >= 23 &&
             ContextCompat.checkSelfPermission( context, android.Manifest.permission.ACCESS_FINE_LOCATION ) != PackageManager.PERMISSION_GRANTED &&
             ContextCompat.checkSelfPermission( context, android.Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
            return  ;
        }

        try   {
            this.longitude = 0.0;
            this.latitude = 0.0;
            this.locationManager = (LocationManager) context.getSystemService(Context.LOCATION_SERVICE);

            // Get GPS and network status
            this.isGPSEnabled = locationManager.isProviderEnabled(LocationManager.GPS_PROVIDER);
            this.isNetworkEnabled = locationManager.isProviderEnabled(LocationManager.NETWORK_PROVIDER);

            if (forceNetwork) isGPSEnabled = false;

            if (!isNetworkEnabled && !isGPSEnabled)    {
                // cannot get location
                this.locationServiceAvailable = false;
            }
            //else
            {
                this.locationServiceAvailable = true;

                if (isNetworkEnabled) {
                    locationManager.requestLocationUpdates(LocationManager.NETWORK_PROVIDER,
                            MIN_TIME_BW_UPDATES,
                            MIN_DISTANCE_CHANGE_FOR_UPDATES, this);
                    if (locationManager != null)   {
                        location = locationManager.getLastKnownLocation(LocationManager.NETWORK_PROVIDER);
                        updateCoordinates();
                    }
                }//end if

                if (isGPSEnabled)  {
                    locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER,
                            MIN_TIME_BW_UPDATES,
                            MIN_DISTANCE_CHANGE_FOR_UPDATES, this);

                    if (locationManager != null)  {
                        location = locationManager.getLastKnownLocation(LocationManager.GPS_PROVIDER);
                        updateCoordinates();
                    }
                }
            }
        } catch (Exception ex)  {
            LogService.log( "Error creating location service: " + ex.getMessage() );

        }
    }       


    @Override
    public void onLocationChanged(Location location)     {
        // do stuff here with location object 
    }
}

I tested with an Android Lollipop device so far only. Hope this works for you.

PostgreSQL ERROR: canceling statement due to conflict with recovery

Running queries on hot-standby server is somewhat tricky — it can fail, because during querying some needed rows might be updated or deleted on primary. As a primary does not know that a query is started on secondary it thinks it can clean up (vacuum) old versions of its rows. Then secondary has to replay this cleanup, and has to forcibly cancel all queries which can use these rows.

Longer queries will be canceled more often.

You can work around this by starting a repeatable read transaction on primary which does a dummy query and then sits idle while a real query is run on secondary. Its presence will prevent vacuuming of old row versions on primary.

More on this subject and other workarounds are explained in Hot Standby — Handling Query Conflicts section in documentation.

How to make a phone call in android and come back to my activity when the call is done?

When PhoneStateListener is used, one need to make sure PHONE_STATE_IDLE following a PHONE_STATE_OFFHOOK is used to trigger the action to be done after the call. If the trigger happens upon seeing PHONE_STATE_IDLE, you will end up doing it before the call. Because you will see the state change PHONE_STATE_IDLE -> PHONE_STATE_OFFHOOK -> PHONE_STATE_IDLE.

What is the syntax for adding an element to a scala.collection.mutable.Map?

The point is that the first line of your codes is not what you expected.

You should use:

val map = scala.collection.mutable.Map[A,B]()

You then have multiple equivalent alternatives to add items:

scala> val map = scala.collection.mutable.Map[String,String]()
map: scala.collection.mutable.Map[String,String] = Map()


scala> map("k1") = "v1"

scala> map
res1: scala.collection.mutable.Map[String,String] = Map((k1,v1))


scala> map += "k2" -> "v2"
res2: map.type = Map((k1,v1), (k2,v2))


scala> map.put("k3", "v3")
res3: Option[String] = None

scala> map
res4: scala.collection.mutable.Map[String,String] = Map((k3,v3), (k1,v1), (k2,v2))

And starting Scala 2.13:

scala> map.addOne("k4" -> "v4")
res5: map.type = HashMap(k1 -> v1, k2 -> v2, k3 -> v3, k4 -> v4)

How to change Git log date formats

I needed the same thing and found the following working for me:

git log -n1 --pretty='format:%cd' --date=format:'%Y-%m-%d %H:%M:%S'

The --date=format formats the date output where the --pretty tells what to print.

How to undo last commit

Warning: Don't do this if you've already pushed

You want to do:

git reset HEAD~

If you don't want the changes and blow everything away:

git reset --hard HEAD~

How to update Ruby with Homebrew?

open terminal

\curl -sSL https://get.rvm.io | bash -s stable

restart terminal then

rvm install ruby-2.4.2

check ruby version it should be 2.4.2

How to send an email using PHP?

If you are interested in html formatted email, make sure to pass Content-type: text/html; in the header. Example:

// multiple recipients
$to  = '[email protected]' . ', '; // note the comma
$to .= '[email protected]';

// subject
$subject = 'Birthday Reminders for August';

// message
$message = '
<html>
<head>
  <title>Birthday Reminders for August</title>
</head>
<body>
  <p>Here are the birthdays upcoming in August!</p>
  <table>
    <tr>
      <th>Person</th><th>Day</th><th>Month</th><th>Year</th>
    </tr>
    <tr>
      <td>Joe</td><td>3rd</td><td>August</td><td>1970</td>
    </tr>
    <tr>
      <td>Sally</td><td>17th</td><td>August</td><td>1973</td>
    </tr>
  </table>
</body>
</html>
';

// To send HTML mail, the Content-type header must be set
$headers  = 'MIME-Version: 1.0' . "\r\n";
$headers .= 'Content-type: text/html; charset=iso-8859-1' . "\r\n";

// Additional headers
$headers .= 'To: Mary <[email protected]>, Kelly <[email protected]>' . "\r\n";
$headers .= 'From: Birthday Reminder <[email protected]>' . "\r\n";
$headers .= 'Cc: [email protected]' . "\r\n";
$headers .= 'Bcc: [email protected]' . "\r\n";

// Mail it
mail($to, $subject, $message, $headers);

For more details, check php mail function.

Why an interface can not implement another interface?

Interface is the class that contains an abstract method that cannot create any object.Since Interface cannot create the object and its not a pure class, Its no worth implementing it.

@Html.DropDownListFor how to set default value

SelectListItem has a Selected property. If you are creating the SelectListItems dynamically, you can just set the one you want as Selected = true and it will then be the default.

SelectListItem defaultItem = new SelectListItem()
{
   Value = 1,
   Text = "Default Item",
   Selected = true
};

Call a function from another file?

Came across the same feature but I had to do the below to make it work.

If you are seeing 'ModuleNotFoundError: No module named', you probably need the dot(.) in front of the filename as below;

from .file import funtion

How to comment a block in Eclipse?

Using Eclipe Oxygen command + Shift + c on macOSx Sierra will add/remove comments out multiple lines of code

What is a good naming convention for vars, methods, etc in C++?

For what it is worth, Bjarne Stroustrup, the original author of C++ has his own favorite style, described here: http://www.stroustrup.com/bs_faq2.html

Subquery returned more than 1 value.This is not permitted when the subquery follows =,!=,<,<=,>,>= or when the subquery is used as an expression

Use In instead of =

 select * from dbo.books
 where isbn in (select isbn from dbo.lending 
                where act between @fdate and @tdate
                and stat ='close'
               )

or you can use Exists

SELECT t1.*,t2.*
FROM  books   t1 
WHERE  EXISTS ( SELECT * FROM dbo.lending t2 WHERE t1.isbn = t2.isbn and
                t2.act between @fdate and @tdate and t2.stat ='close' )

Easiest way to parse a comma delimited string to some kind of object I can loop through to access the individual values?

Use a loop on the split values

string values = "0,1,2,3,4,5,6,7,8,9";

foreach(string value in values.split(','))
{
    //do something with individual value
}

how to avoid extra blank page at end while printing?

Add this css to same page to extend css file.

<style type="text/css">
   <!--
   html, body {
    height: 95%; 
    margin: 0 0 0 0;
     }
   -->
</style>

How can I rename column in laravel using migration?

first thing you want to do is to create your migration file.

Type in your command line

php artisan make:migration rename_stk_column --table="YOUR TABLE" --create

After creating the file. Open the new created migration file in your app folder under database/migrations.

In your up method insert this:

Schema::table('stnk', function(Blueprint $table)
    {
        $table->renameColumn('id', 'id_stnk');
    });
}

and in your down method:

    Schema::table('stnk', function(Blueprint $table)
    {
        $table->renameColumn('id_stnk', 'id);
    });
}

then in your command line just type

php artisan migrate

Then wollah! you have just renamed id to id_stnk. BTW you can use

php artisan migrate:rollback

to undo the changes. Goodluck

How to store(bitmap image) and retrieve image from sqlite database in android?

If you are working with Android's MediaStore database, here is how to store an image and then display it after it is saved.

on button click write this

 Intent in = new Intent(Intent.ACTION_PICK,
                    android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI);
            in.putExtra("crop", "true");
            in.putExtra("outputX", 100);
            in.putExtra("outputY", 100);
            in.putExtra("scale", true);
            in.putExtra("return-data", true);

            startActivityForResult(in, 1);

then do this in your activity

@Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        // TODO Auto-generated method stub
        super.onActivityResult(requestCode, resultCode, data);

        if (requestCode == 1 && resultCode == RESULT_OK && data != null) {

            Bitmap bmp = (Bitmap) data.getExtras().get("data");

            img.setImageBitmap(bmp);
            btnadd.requestFocus();

            ByteArrayOutputStream baos = new ByteArrayOutputStream();
            bmp.compress(Bitmap.CompressFormat.JPEG, 100, baos);
            byte[] b = baos.toByteArray();
            String encodedImageString = Base64.encodeToString(b, Base64.DEFAULT);

            byte[] bytarray = Base64.decode(encodedImageString, Base64.DEFAULT);
            Bitmap bmimage = BitmapFactory.decodeByteArray(bytarray, 0,
                    bytarray.length);

        }

    }

How to improve Netbeans performance?

Here are my netbeans options for etc/netbeans.conf using G1 GC and some other improvements.

netbeans_default_options="-J-server -J-Xss4m -J-Xms256m -J-Xmx512m -J-XX:PermSize=256m -J-Dapple.laf.useScreenMenuBar=true -J-Dapple.awt.graphics.UseQuartz=true -J-Dsun.java2d.noddraw=true -J-Dsun.java2d.dpiaware=true -J-Dsun.zip.disableMemoryMapping=true -J-Xverify:none -J-XX:+UseG1GC -J-XX:+TieredCompilation -J-XX:+AggressiveOpts -J-Dswing.aatext=true -J-Dawt.useSystemAAFontSettings=lcd -J-Dorg.netbeans.editor.aa.extra.hints=true"

The font settings (swing.aatex and following) are optional - set as you need or remove.

Those settings are boosting my netbeans a lot!

What is the best way to iterate over multiple lists at once?

The usual way is to use zip():

for x, y in zip(a, b):
    # x is from a, y is from b

This will stop when the shorter of the two iterables a and b is exhausted. Also worth noting: itertools.izip() (Python 2 only) and itertools.izip_longest() (itertools.zip_longest() in Python 3).

android - how to convert int to string and place it in a EditText?

try Integer.toString(integer value); method as

ed = (EditText)findViewById(R.id.box);
int x = 10;
ed.setText(Integer.toString(x));

DB2 Date format

One more solution REPLACE (CHAR(current date, ISO),'-','')

Aren't Python strings immutable? Then why does a + " " + b work?

Python strings are immutable. However, a is not a string: it is a variable with a string value. You can't mutate the string, but can change what value of the variable to a new string.

Error "package android.support.v7.app does not exist"

For what it's worth:

I ran in to this issue when using Xamarin, even though I did have the Support packages installed, both the v4 and the v7 ones.

It was resolved for me by doing Build -> Clean All.

Equivalent of explode() to work with strings in MySQL

This is actually a modified version of the selected answer in order to support Unicode characters but I don't have enough reputation to comment there.

CREATE FUNCTION SPLIT_STRING(str VARCHAR(255) CHARSET utf8, delim VARCHAR(12), pos INT) RETURNS varchar(255) CHARSET utf8
RETURN REPLACE(SUBSTRING(SUBSTRING_INDEX(str, delim, pos),
       CHAR_LENGTH(SUBSTRING_INDEX(str, delim, pos-1)) + 1),
       delim, '')

The modifications are the following:

  • The first parameter is set as utf8
  • The function is set to return utf8
  • The code uses CHAR_LENGTH() instead of LENGTH() to calculate the character length and not the byte length.

How to set the color of an icon in Angular Material?

Or simply

add to your element

[ngStyle]="{'color': myVariableColor}"

eg

<mat-icon [ngStyle]="{'color': myVariableColor}">{{ getActivityIcon() }}</mat-icon>

Where color can be defined at another component etc

unique combinations of values in selected columns in pandas data frame and count

Slightly related, I was looking for the unique combinations and I came up with this method:

def unique_columns(df,columns):

    result = pd.Series(index = df.index)

    groups = meta_data_csv.groupby(by = columns)
    for name,group in groups:
       is_unique = len(group) == 1
       result.loc[group.index] = is_unique

    assert not result.isnull().any()

    return result

And if you only want to assert that all combinations are unique:

df1.set_index(['A','B']).index.is_unique

SQL, Postgres OIDs, What are they and why are they useful?

If you still use OID, it would be better to remove the dependency on it, because in recent versions of Postgres it is no longer supported. This can stop (temporarily until you solve it) your migration from version 10 to 12 for example.

See also: https://dev.to/rafaelbernard/postgresql-pgupgrade-from-10-to-12-566i

Create nice column output in python

Here is a variation of the Shawn Chin's answer. The width is fixed per column, not over all columns. There is also a border below the first row and between the columns. (icontract library is used to enforce the contracts.)

@icontract.pre(
    lambda table: not table or all(len(row) == len(table[0]) for row in table))
@icontract.post(lambda table, result: result == "" if not table else True)
@icontract.post(lambda result: not result.endswith("\n"))
def format_table(table: List[List[str]]) -> str:
    """
    Format the table as equal-spaced columns.

    :param table: rows of cells
    :return: table as string
    """
    cols = len(table[0])

    col_widths = [max(len(row[i]) for row in table) for i in range(cols)]

    lines = []  # type: List[str]
    for i, row in enumerate(table):
        parts = []  # type: List[str]

        for cell, width in zip(row, col_widths):
            parts.append(cell.ljust(width))

        line = " | ".join(parts)
        lines.append(line)

        if i == 0:
            border = []  # type: List[str]

            for width in col_widths:
                border.append("-" * width)

            lines.append("-+-".join(border))

    result = "\n".join(lines)

    return result

Here is an example:

>>> table = [['column 0', 'another column 1'], ['00', '01'], ['10', '11']]
>>> result = packagery._format_table(table=table)
>>> print(result)
column 0 | another column 1
---------+-----------------
00       | 01              
10       | 11              

Java program to find the largest & smallest number in n numbers without using arrays

import java.util.Scanner;

public class LargestSmallestNum {

    public void findLargestSmallestNo() {

        int smallest = Integer.MAX_VALUE;
        int large = 0;
        int num;

        System.out.println("enter the number");

        Scanner input = new Scanner(System.in);

        int n = input.nextInt();

        for (int i = 0; i < n; i++) {

            num = input.nextInt();

            if (num > large)
                large = num;

            if (num < smallest)
                smallest = num;

            System.out.println("the largest is:" + large);
            System.out.println("Smallest no is : "  + smallest);
        }
    }

    public static void main(String...strings){
        LargestSmallestNum largestSmallestNum = new LargestSmallestNum();
        largestSmallestNum.findLargestSmalestNo();
    }
}

How do I make a newline after a twitter bootstrap element?

Like KingCronus mentioned in the comments you can use the row class to make the list or heading on its own line. You could use the row class on either or both elements:

<ul class="nav nav-tabs span2 row">
  <li><a href="./index.html"><i class="icon-black icon-music"></i></a></li>
  <li><a href="./about.html"><i class="icon-black icon-eye-open"></i></a></li>
  <li><a href="./team.html"><i class="icon-black icon-user"></i></a></li>
  <li><a href="./contact.html"><i class="icon-black icon-envelope"></i></a></li>
</ul>

<div class="well span6 row">
  <h3>I wish this appeared on the next line without having to gratuitously use BR!</h3>
</div>

Is there a "theirs" version of "git merge -s ours"?

Older versions of git allowed you to use the "theirs" merge strategy:

git pull --strategy=theirs remote_branch

But this has since been removed, as explained in this message by Junio Hamano (the Git maintainer). As noted in the link, instead you would do this:

git fetch origin
git reset --hard origin

Beware, though, that this is different than an actual merge. Your solution is probably the option you're really looking for.

How to change the output color of echo in Linux

You can use these ANSI escape codes:

Black        0;30     Dark Gray     1;30
Red          0;31     Light Red     1;31
Green        0;32     Light Green   1;32
Brown/Orange 0;33     Yellow        1;33
Blue         0;34     Light Blue    1;34
Purple       0;35     Light Purple  1;35
Cyan         0;36     Light Cyan    1;36
Light Gray   0;37     White         1;37

And then use them like this in your script:

#    .---------- constant part!
#    vvvv vvvv-- the code from above
RED='\033[0;31m'
NC='\033[0m' # No Color
printf "I ${RED}love${NC} Stack Overflow\n"

which prints love in red.

From @james-lim's comment, if you are using the echo command, be sure to use the -e flag to allow backslash escapes.

# Continued from above example
echo -e "I ${RED}love${NC} Stack Overflow"

(don't add "\n" when using echo unless you want to add an additional empty line)

What are Aggregates and PODs and how/why are they special?

Changes in C++17

Download the C++17 International Standard final draft here.

Aggregates

C++17 expands and enhances aggregates and aggregate initialization. The standard library also now includes an std::is_aggregate type trait class. Here is the formal definition from section 11.6.1.1 and 11.6.1.2 (internal references elided):

An aggregate is an array or a class with
— no user-provided, explicit, or inherited constructors,
— no private or protected non-static data members,
— no virtual functions, and
— no virtual, private, or protected base classes.
[ Note: Aggregate initialization does not allow accessing protected and private base class’ members or constructors. —end note ]
The elements of an aggregate are:
— for an array, the array elements in increasing subscript order, or
— for a class, the direct base classes in declaration order, followed by the direct non-static data members that are not members of an anonymous union, in declaration order.

What changed?

  1. Aggregates can now have public, non-virtual base classes. Furthermore, it is not a requirement that base classes be aggregates. If they are not aggregates, they are list-initialized.
struct B1 // not a aggregate
{
    int i1;
    B1(int a) : i1(a) { }
};
struct B2
{
    int i2;
    B2() = default;
};
struct M // not an aggregate
{
    int m;
    M(int a) : m(a) { }
};
struct C : B1, B2
{
    int j;
    M m;
    C() = default;
};
C c { { 1 }, { 2 }, 3, { 4 } };
cout
    << "is C aggregate?: " << (std::is_aggregate<C>::value ? 'Y' : 'N')
    << " i1: " << c.i1 << " i2: " << c.i2
    << " j: " << c.j << " m.m: " << c.m.m << endl;

//stdout: is C aggregate?: Y, i1=1 i2=2 j=3 m.m=4
  1. Explicit defaulted constructors are disallowed
struct D // not an aggregate
{
    int i = 0;
    D() = default;
    explicit D(D const&) = default;
};
  1. Inheriting constructors are disallowed
struct B1
{
    int i1;
    B1() : i1(0) { }
};
struct C : B1 // not an aggregate
{
    using B1::B1;
};


Trivial Classes

The definition of trivial class was reworked in C++17 to address several defects that were not addressed in C++14. The changes were technical in nature. Here is the new definition at 12.0.6 (internal references elided):

A trivially copyable class is a class:
— where each copy constructor, move constructor, copy assignment operator, and move assignment operator is either deleted or trivial,
— that has at least one non-deleted copy constructor, move constructor, copy assignment operator, or move assignment operator, and
— that has a trivial, non-deleted destructor.
A trivial class is a class that is trivially copyable and has one or more default constructors, all of which are either trivial or deleted and at least one of which is not deleted. [ Note: In particular, a trivially copyable or trivial class does not have virtual functions or virtual base classes.—end note ]

Changes:

  1. Under C++14, for a class to be trivial, the class could not have any copy/move constructor/assignment operators that were non-trivial. However, then an implicitly declared as defaulted constructor/operator could be non-trivial and yet defined as deleted because, for example, the class contained a subobject of class type that could not be copied/moved. The presence of such non-trivial, defined-as-deleted constructor/operator would cause the whole class to be non-trivial. A similar problem existed with destructors. C++17 clarifies that the presence of such constructor/operators does not cause the class to be non-trivially copyable, hence non-trivial, and that a trivially copyable class must have a trivial, non-deleted destructor. DR1734, DR1928
  2. C++14 allowed a trivially copyable class, hence a trivial class, to have every copy/move constructor/assignment operator declared as deleted. If such as class was also standard layout, it could, however, be legally copied/moved with std::memcpy. This was a semantic contradiction, because, by defining as deleted all constructor/assignment operators, the creator of the class clearly intended that the class could not be copied/moved, yet the class still met the definition of a trivially copyable class. Hence in C++17 we have a new clause stating that trivially copyable class must have at least one trivial, non-deleted (though not necessarily publicly accessible) copy/move constructor/assignment operator. See N4148, DR1734
  3. The third technical change concerns a similar problem with default constructors. Under C++14, a class could have trivial default constructors that were implicitly defined as deleted, yet still be a trivial class. The new definition clarifies that a trivial class must have a least one trivial, non-deleted default constructor. See DR1496

Standard-layout Classes

The definition of standard-layout was also reworked to address defect reports. Again the changes were technical in nature. Here is the text from the standard (12.0.7). As before, internal references are elided:

A class S is a standard-layout class if it:
— has no non-static data members of type non-standard-layout class (or array of such types) or reference,
— has no virtual functions and no virtual base classes,
— has the same access control for all non-static data members,
— has no non-standard-layout base classes,
— has at most one base class subobject of any given type,
— has all non-static data members and bit-fields in the class and its base classes first declared in the same class, and
— has no element of the set M(S) of types (defined below) as a base class.108
M(X) is defined as follows:
— If X is a non-union class type with no (possibly inherited) non-static data members, the set M(X) is empty.
— If X is a non-union class type whose first non-static data member has type X0 (where said member may be an anonymous union), the set M(X) consists of X0 and the elements of M(X0).
— If X is a union type, the set M(X) is the union of all M(Ui) and the set containing all Ui, where each Ui is the type of the ith non-static data member of X.
— If X is an array type with element type Xe, the set M(X) consists of Xe and the elements of M(Xe).
— If X is a non-class, non-array type, the set M(X) is empty.
[ Note: M(X) is the set of the types of all non-base-class subobjects that are guaranteed in a standard-layout class to be at a zero offset in X. —end note ]
[ Example:

struct B { int i; }; // standard-layout class
struct C : B { }; // standard-layout class
struct D : C { }; // standard-layout class
struct E : D { char : 4; }; // not a standard-layout class
struct Q {};
struct S : Q { };
struct T : Q { };
struct U : S, T { }; // not a standard-layout class
—end example ]
108) This ensures that two subobjects that have the same class type and that belong to the same most derived object are not allocated at the same address.

Changes:

  1. Clarified that the requirement that only one class in the derivation tree "has" non-static data members refers to a class where such data members are first declared, not classes where they may be inherited, and extended this requirement to non-static bit fields. Also clarified that a standard-layout class "has at most one base class subobject of any given type." See DR1813, DR1881
  2. The definition of standard-layout has never allowed the type of any base class to be the same type as the first non-static data member. It is to avoid a situation where a data member at offset zero has the same type as any base class. The C++17 standard provides a more rigorous, recursive definition of "the set of the types of all non-base-class subobjects that are guaranteed in a standard-layout class to be at a zero offset" so as to prohibit such types from being the type of any base class. See DR1672, DR2120.

Note: The C++ standards committee intended the above changes based on defect reports to apply to C++14, though the new language is not in the published C++14 standard. It is in the C++17 standard.

What is two way binding?

Worth mentioning that there are many different solutions which offer two way binding and play really nicely.

I have had a pleasant experience with this model binder - https://github.com/theironcook/Backbone.ModelBinder. which gives sensible defaults yet a lot of custom jquery selector mapping of model attributes to input elements.

There is a more extended list of backbone extensions/plugins on github

Checking if an object is a given type in Swift

Why not to use something like this

fileprivate enum types {
    case typeString
    case typeInt
    case typeDouble
    case typeUnknown
}

fileprivate func typeOfAny(variable: Any) -> types {
    if variable is String {return types.typeString}
    if variable is Int {return types.typeInt}
    if variable is Double {return types.typeDouble}
    return types.typeUnknown
}

in Swift 3.

How to compare two Carbon Timestamps?

First, convert the timestamp using the built-in eloquent functionality, as described in this answer.

Then you can just use Carbon's min() or max() function for comparison. For example:

$dt1 = Carbon::create(2012, 1, 1, 0, 0, 0); $dt2 = Carbon::create(2014, 1, 30, 0, 0, 0); echo $dt1->min($dt2);

This will echo the lesser of the two dates, which in this case is $dt1.

See http://carbon.nesbot.com/docs/

ng-repeat finish event

Here is a repeat-done directive that calls a specified function when true. I have found that the called function must use $timeout with interval=0 before doing DOM manipulation, such as initializing tooltips on the rendered elements. jsFiddle: http://jsfiddle.net/tQw6w/

In $scope.layoutDone, try commenting out the $timeout line and uncommenting the "NOT CORRECT!" line to see the difference in the tooltips.

<ul>
    <li ng-repeat="feed in feedList" repeat-done="layoutDone()" ng-cloak>
    <a href="{{feed}}" title="view at {{feed | hostName}}" data-toggle="tooltip">{{feed | strip_http}}</a>
    </li>
</ul>

JS:

angular.module('Repeat_Demo', [])

    .directive('repeatDone', function() {
        return function(scope, element, attrs) {
            if (scope.$last) { // all are rendered
                scope.$eval(attrs.repeatDone);
            }
        }
    })

    .filter('strip_http', function() {
        return function(str) {
            var http = "http://";
            return (str.indexOf(http) == 0) ? str.substr(http.length) : str;
        }
    })

    .filter('hostName', function() {
        return function(str) {
            var urlParser = document.createElement('a');
            urlParser.href = str;
            return urlParser.hostname;
        }
    })

    .controller('AppCtrl', function($scope, $timeout) {

        $scope.feedList = [
            'http://feeds.feedburner.com/TEDTalks_video',
            'http://feeds.nationalgeographic.com/ng/photography/photo-of-the-day/',
            'http://sfbay.craigslist.org/eng/index.rss',
            'http://www.slate.com/blogs/trending.fulltext.all.10.rss',
            'http://feeds.current.com/homepage/en_US.rss',
            'http://feeds.current.com/items/popular.rss',
            'http://www.nytimes.com/services/xml/rss/nyt/HomePage.xml'
        ];

        $scope.layoutDone = function() {
            //$('a[data-toggle="tooltip"]').tooltip(); // NOT CORRECT!
            $timeout(function() { $('a[data-toggle="tooltip"]').tooltip(); }, 0); // wait...
        }

    })

Warning about `$HTTP_RAW_POST_DATA` being deprecated

It turns out that my understanding of the error message was wrong. I'd say it features very poor choice of words. Googling around shown me someone else misunderstood the message exactly like I did - see PHP bug #66763.

After totally unhelpful "This is the way the RMs wanted it to be." response to that bug by Mike, Tyrael explains that setting it to "-1" doesn't make just the warning to go away. It does the right thing, i.e. it completely disables populating the culprit variable. Turns out that having it set to 0 STILL populates data under some circumstances. Talk about bad design! To cite PHP RFC:

Change always_populate_raw_post_data INI setting to accept three values instead of two.

  • -1: The behavior of master; don't ever populate $GLOBALS[HTTP_RAW_POST_DATA]
  • 0/off/whatever: BC behavior (populate if content-type is not registered or request method is other than POST)
  • 1/on/yes/true: BC behavior (always populate $GLOBALS[HTTP_RAW_POST_DATA])

So yeah, setting it to -1 not only avoids the warning, like the message said, but it also finally disables populating this variable, which is what I wanted.

MySQL: Cloning a MySQL database on the same MySql instance

You can do something like the following:

mysqldump -u[username] -p[password] database_name_for_clone 
 | mysql -u[username] -p[password] new_database_name

IIS - can't access page by ip address instead of localhost

In IIS Manager, I added a binding to the site specifying the IP address. Previously, all my bindings were host names.

What happens to a declared, uninitialized variable in C? Does it have a value?

0 if static or global, indeterminate if storage class is auto

C has always been very specific about the initial values of objects. If global or static, they will be zeroed. If auto, the value is indeterminate.

This was the case in pre-C89 compilers and was so specified by K&R and in DMR's original C report.

This was the case in C89, see section 6.5.7 Initialization.

If an object that has automatic storage duration is not initialized explicitely, its value is indeterminate. If an object that has static storage duration is not initialized explicitely, it is initialized implicitely as if every member that has arithmetic type were assigned 0 and every member that has pointer type were assigned a null pointer constant.

This was the case in C99, see section 6.7.8 Initialization.

If an object that has automatic storage duration is not initialized explicitly, its value is indeterminate. If an object that has static storage duration is not initialized explicitly, then:
— if it has pointer type, it is initialized to a null pointer;
— if it has arithmetic type, it is initialized to (positive or unsigned) zero;
— if it is an aggregate, every member is initialized (recursively) according to these rules;
— if it is a union, the first named member is initialized (recursively) according to these rules.

As to what exactly indeterminate means, I'm not sure for C89, C99 says:

3.17.2
indeterminate value

either an unspecified value or a trap representation

But regardless of what standards say, in real life, each stack page actually does start off as zero, but when your program looks at any auto storage class values, it sees whatever was left behind by your own program when it last used those stack addresses. If you allocate a lot of auto arrays you will see them eventually start neatly with zeroes.

You might wonder, why is it this way? A different SO answer deals with that question, see: https://stackoverflow.com/a/2091505/140740

How to post JSON to a server using C#?

var data = Encoding.ASCII.GetBytes(json);

byte[] postBytes = Encoding.UTF8.GetBytes(json);

Use ASCII instead of UFT8

Eclipse error ... cannot be resolved to a type

I was importing the source into the wrong folder. I'm so used to using Visual Studio, that I expect all IDE's to be so accommodating.

AngularJS Error: Cross origin requests are only supported for protocol schemes: http, data, chrome-extension, https

Navigate to C:/user/project/index.html, open it with Visual Studio 2017, File > View in Browser or press Ctrl+Shift+W

How to calculate UILabel width based on text length?

yourLabel.intrinsicContentSize.width for Objective-C / Swift

Multi-line string with extra space (preserved indentation)

I came hear looking for this answer but also wanted to pipe it to another command. The given answer is correct but if anyone wants to pipe it, you need to pipe it before the multi-line string like this

echo | tee /tmp/pipetest << EndOfMessage
This is line 1.
This is line 2.
Line 3.
EndOfMessage

This will allow you to have a multi line string but also put it in the stdin of a subsequent command.

Lombok added but getters and setters not recognized in Intellij IDEA

In IDEA 2019.3.3 community on mac ( catalina)

IntelliJ IDEA => preferences


Build,Execution,Deployment=>Compiler=>Annotation Processors:

Check Enable annotation Processing

How to store image in SQL Server database tables column

Insert Into FEMALE(ID, Image)
Select '1', BulkColumn 
from Openrowset (Bulk 'D:\thepathofimage.jpg', Single_Blob) as Image

You will also need admin rights to run the query.

HintPath vs ReferencePath in Visual Studio

According to this MSDN blog: https://blogs.msdn.microsoft.com/manishagarwal/2005/09/28/resolving-file-references-in-team-build-part-2/

There is a search order for assemblies when building. The search order is as follows:

  • Files from the current project – indicated by ${CandidateAssemblyFiles}.
  • $(ReferencePath) property that comes from .user/targets file.
  • %(HintPath) metadata indicated by reference item.
  • Target framework directory.
  • Directories found in registry that uses AssemblyFoldersEx Registration.
  • Registered assembly folders, indicated by ${AssemblyFolders}.
  • $(OutputPath) or $(OutDir)
  • GAC

So, if the desired assembly is found by HintPath, but an alternate assembly can be found using ReferencePath, it will prefer the ReferencePath'd assembly to the HintPath'd one.

How to count objects in PowerShell?

in my exchange the cmd-let you presented did not work, the answer was null, so I had to make a little correction and worked fine for me:

@(get-transportservice | get-messagetrackinglog -Resultsize unlimited -Start "MM/DD/AAAA HH:MM" -End "MM/DD/AAAA HH:MM" -recipients "[email protected]" | where {$_.Event
ID -eq "DELIVER"}).count

Updating GUI (WPF) using a different thread

You have a couple of options here, I think.

One would be to use a BackgroundWorker. This is a common helper for multithreading in applications. It exposes a DoWork event which is handled on a background thread from the Thread Pool and a RunWorkerCompleted event which is invoked back on the main thread when the background thread completes. It also has the benefit of try/catching the code running on the background thread so that an unhandled exception doesn't kill the application.

If you don't want to go that route, you can use the WPF dispatcher object to invoke an action to update the GUI back onto the main thread. Random reference:

http://www.switchonthecode.com/tutorials/working-with-the-wpf-dispatcher

There are many other options around too, but these are the two most common that come to mind.

How do I concatenate two text files in PowerShell?

To concat files in command prompt it would be

type file1.txt file2.txt file3.txt > files.txt

PowerShell converts the type command to Get-Content, which means you will get an error when using the type command in PowerShell because the Get-Content command requires a comma separating the files. The same command in PowerShell would be

Get-Content file1.txt,file2.txt,file3.txt | Set-Content files.txt

How to use SVN, Branch? Tag? Trunk?

I asked myself the same questions when we came to implement Subversion here -- about 20 developers spread across 4 - 6 projects. I didn't find any one good source with ''the answer''. Here are some parts of how our answer has developed over the last 3 years:

-- commit as often as is useful; our rule of thumb is commit whenever you have done sufficient work that it would be a problem having to re-do it if the modifications got lost; sometimes I commit every 15 minutes or so, other times it might be days (yes, sometimes it takes me a day to write 1 line of code)

-- we use branches, as one of your earlier answers suggested, for different development paths; right now for one of our programs we have 3 active branches: 1 for the main development, 1 for the as-yet-unfinished effort to parallelise the program, and 1 for the effort to revise it to use XML input and output files;

-- we scarcely use tags, though we think we ought to use them to identify releases to production;

Think of development proceeding along a single path. At some time or state of development marketing decide to release the first version of the product, so you plant a flag in the path labelled '1' (or '1.0' or what have you). At some other time some bright spark decides to parallelise the program, but decides that that will take weeks and that people want to keep going down the main path in the meantime. So you build a fork in the path and different people wander off down the different forks.

The flags in the road are called 'tags' ,and the forks in the road are where 'branches' divide. Occasionally, also, branches come back together.

-- we put all material necessary to build an executable (or system) into the repository; That means at least source code and make file (or project files for Visual Studio). But when we have icons and config files and all that other stuff, that goes into the repository. Some documentation finds its way into the repo; certainly any documentation such as help files which might be integral to the program does, and it's a useful place to put developer documentation.

We even put Windows executables for our production releases in there, to provide a single location for people looking for software -- our Linux releases go to a server so don't need to be stored.

-- we don't require that the repository at all times be capable of delivering a latest version which builds and executes; some projects work that way, some don't; the decision rests with the project manager and depends on many factors but I think it breaks down when making major changes to a program.

Specified cast is not valid.. how to resolve this

If you are expecting double, decimal, float, integer why not use the one which accomodates all namely decimal (128 bits are enough for most numbers you are looking at).

instead of (double)value use decimal.Parse(value.ToString()) or Convert.ToDecimal(value)

How to enable and use HTTP PUT and DELETE with Apache2 and PHP?

On linux, /etc/apache2/mods-enabled/php5.conf dans php5.load exists. If not, enables this modules (may require to sudo apt-get install libapache2-mod-php5).

Find the division remainder of a number

From Python 3.7, there is a new math.remainder() function:

from math import remainder
print(remainder(26,7))

Output:

-2.0  # not 5

Note, as above, it's not the same as %.

Quoting the documentation:

math.remainder(x, y)

Return the IEEE 754-style remainder of x with respect to y. For finite x and finite nonzero y, this is the difference x - n*y, where n is the closest integer to the exact value of the quotient x / y. If x / y is exactly halfway between two consecutive integers, the nearest even integer is used for n. The remainder r = remainder(x, y) thus always satisfies abs(r) <= 0.5 * abs(y).

Special cases follow IEEE 754: in particular, remainder(x, math.inf) is x for any finite x, and remainder(x, 0) and remainder(math.inf, x) raise ValueError for any non-NaN x. If the result of the remainder operation is zero, that zero will have the same sign as x.

On platforms using IEEE 754 binary floating-point, the result of this operation is always exactly representable: no rounding error is introduced.

Issue29962 describes the rationale for creating the new function.

Rolling or sliding window iterator?

Let's make it lazy!

from itertools import islice, tee

def window(iterable, size): 
    iterators = tee(iterable, size) 
    iterators = [islice(iterator, i, None) for i, iterator in enumerate(iterators)]  
    yield from zip(*iterators)

list(window(range(5), 3))
# [(0, 1, 2), (1, 2, 3), (2, 3, 4)]

Windows error 2 occured while loading the Java VM

'Windows error 2' has dozens of meanings (52 that I could find).

The most common one is ERROR_FILE_NOT_FOUND, which can be found in winerror.h. Without more context, that's the best I can guess. Did you check the event logs to see if there's more information there?

add onclick function to a submit button

I need to see your submit button html tag for better help. I am not familiar with php and how it handles the postback, but I guess depending on what you want to do, you have three options:

  1. Getting the handling onclick button on the client-side: In this case you only need to call a javascript function.

_x000D_
_x000D_
function foo() {_x000D_
   alert("Submit button clicked!");_x000D_
   return true;_x000D_
}
_x000D_
<input type="submit" value="submit" onclick="return foo();" />
_x000D_
_x000D_
_x000D_

  1. If you want to handle the click on the server-side, you should first make sure that the form tag method attribute is set to post:

    <form method="post">
    
  2. You can use onsubmit event from form itself to bind your function to it.

_x000D_
_x000D_
<form name="frm1" method="post" onsubmit="return greeting()">_x000D_
    <input type="text" name="fname">_x000D_
    <input type="submit" value="Submit">_x000D_
</form>
_x000D_
_x000D_
_x000D_

Create a List that contain each Line of a File

f.readlines() returns a list that contains each line as an item in the list

if you want eachline to be split(",") you can use list comprehensions

[ list.split(",") for line in file ]

Fake "click" to activate an onclick method

If you're using jQuery, you need to use the .trigger function, so it would be something like:

element.trigger('click');

http://api.jquery.com/trigger/

How to call a method after a delay in Android

Kotlin

    Handler(Looper.getMainLooper()).postDelayed({
      //Do something after 100ms
    }, 100)

Java

    final Handler handler = new Handler(Looper.getMainLooper());
    handler.postDelayed(new Runnable() {
      @Override
      public void run() {
        //Do something after 100ms
      }
    }, 100);

Converting an object to a string

var obj={
name:'xyz',
Address:'123, Somestreet'
 }
var convertedString=JSON.stringify(obj) 
 console.log("literal object is",obj ,typeof obj);
 console.log("converted string :",convertedString);
 console.log(" convertedString type:",typeof convertedString);

Replace last occurrence of a string in a string

For the interested: I've written a function that utilises preg_match so that you're able to replace from right hand side using regex.

function preg_rreplace($search, $replace, $subject) {
    preg_match_all($search, $subject, $matches, PREG_SET_ORDER);
    $lastMatch = end($matches);

    if ($lastMatch && false !== $pos = strrpos($subject, $lastMatchedStr = $lastMatch[0])) {
        $subject = substr_replace($subject, $replace, $pos, strlen($lastMatchedStr));
    }

    return $subject;
}

Or as a shorthand combination/implementation of both options:

function str_rreplace($search, $replace, $subject) {
    return (false !== $pos = strrpos($subject, $search)) ?
        substr_replace($subject, $replace, $pos, strlen($search)) : $subject;
}
function preg_rreplace($search, $replace, $subject) {
    preg_match_all($search, $subject, $matches, PREG_SET_ORDER);
    return ($lastMatch = end($matches)) ? str_rreplace($lastMatch[0], $replace, $subject) : $subject;
}

based on https://stackoverflow.com/a/3835653/3017716 and https://stackoverflow.com/a/23343396/3017716