Programs & Examples On #Unmanaged memory

Loading all images using imread from a given folder

you can use glob function to do this. see the example

import cv2
import glob
for img in glob.glob("path/to/folder/*.png"):
    cv_img = cv2.imread(img)

WebAPI to Return XML

Here's another way to be compatible with an IHttpActionResult return type. In this case I am asking it to use the XML Serializer(optional) instead of Data Contract serializer, I'm using return ResponseMessage( so that I get a return compatible with IHttpActionResult:

return ResponseMessage(new HttpResponseMessage(HttpStatusCode.OK)
       {
           Content = new ObjectContent<SomeType>(objectToSerialize, 
              new System.Net.Http.Formatting.XmlMediaTypeFormatter { 
                  UseXmlSerializer = true 
              })
       });

Allowing Java to use an untrusted certificate for SSL/HTTPS connection

Here is some relevant code:

// Create a trust manager that does not validate certificate chains
TrustManager[] trustAllCerts = new TrustManager[]{
    new X509TrustManager() {
        public java.security.cert.X509Certificate[] getAcceptedIssuers() {
            return null;
        }
        public void checkClientTrusted(
            java.security.cert.X509Certificate[] certs, String authType) {
        }
        public void checkServerTrusted(
            java.security.cert.X509Certificate[] certs, String authType) {
        }
    }
};

// Install the all-trusting trust manager
try {
    SSLContext sc = SSLContext.getInstance("SSL");
    sc.init(null, trustAllCerts, new java.security.SecureRandom());
    HttpsURLConnection.setDefaultSSLSocketFactory(sc.getSocketFactory());
} catch (Exception e) {
}

// Now you can access an https URL without having the certificate in the truststore
try {
    URL url = new URL("https://hostname/index.html");
} catch (MalformedURLException e) {
}

This will completely disable SSL checking—just don't learn exception handling from such code!

To do what you want, you would have to implement a check in your TrustManager that prompts the user.

Check if current date is between two dates Oracle SQL

SELECT to_char(emp_login_date,'DD-MON-YYYY HH24:MI:SS'),A.* 
FROM emp_log A
WHERE emp_login_date BETWEEN to_date(to_char('21-MAY-2015 11:50:14'),'DD-MON-YYYY HH24:MI:SS')
AND
to_date(to_char('22-MAY-2015 17:56:52'),'DD-MON-YYYY HH24:MI:SS') 
ORDER BY emp_login_date

Undefined symbols for architecture x86_64 on Xcode 6.1

Yes, I think the library you are using is not compatible with 64 bit version but you can solve the problem -

Just navigate to Build Settings>Architectures & replace $(ARCHS_STANDARD) to $(ARCHS_STANDARD_32_BIT)

So that your xcode build your project with 32 bit supported version.

Numpy array dimensions

You can use .shape

In: a = np.array([[1,2,3],[4,5,6]])
In: a.shape
Out: (2, 3)
In: a.shape[0] # x axis
Out: 2
In: a.shape[1] # y axis
Out: 3

Room persistance library. Delete all

Combining what Dick Lucas says and adding a reset autoincremental from other StackOverFlow posts, i think this can work:

fun clearAndResetAllTables(): Boolean {
    val db = db ?: return false

    // reset all auto-incrementalValues
    val query = SimpleSQLiteQuery("DELETE FROM sqlite_sequence")

    db.beginTransaction()
    return try {
        db.clearAllTables()
        db.query(query)
        db.setTransactionSuccessful()
        true
    } catch (e: Exception){
        false
    } finally {
        db.endTransaction()
    }
}

Working around MySQL error "Deadlock found when trying to get lock; try restarting transaction"

The idea of retrying the query in case of Deadlock exception is good, but it can be terribly slow, since mysql query will keep waiting for locks to be released. And incase of deadlock mysql is trying to find if there is any deadlock, and even after finding out that there is a deadlock, it waits a while before kicking out a thread in order to get out from deadlock situation.

What I did when I faced this situation is to implement locking in your own code, since it is the locking mechanism of mysql is failing due to a bug. So I implemented my own row level locking in my java code:

private HashMap<String, Object> rowIdToRowLockMap = new HashMap<String, Object>();
private final Object hashmapLock = new Object();
public void handleShortCode(Integer rowId)
{
    Object lock = null;
    synchronized(hashmapLock)
    {
      lock = rowIdToRowLockMap.get(rowId);
      if (lock == null)
      {
          rowIdToRowLockMap.put(rowId, lock = new Object());
      }
    }
    synchronized (lock)
    {
        // Execute your queries on row by row id
    }
}

Java NoSuchAlgorithmException - SunJSSE, sun.security.ssl.SSLContextImpl$DefaultSSLContext

I had the similar issue. The problem was in the passwords: the Keystore and private key used different passwords. (KeyStore explorer was used)

After creating Keystore with the same password as private key had the issue was resolved.

How to run a function when the page is loaded?

As soon as the page load the function will be ran:

(*your function goes here*)(); 

Alternatively:

document.onload = functionName();
window.onload = functionName(); 

Efficiently checking if arbitrary object is NaN in Python / numpy / pandas?

Is your type really arbitrary? If you know it is just going to be a int float or string you could just do

 if val.dtype == float and np.isnan(val):

assuming it is wrapped in numpy , it will always have a dtype and only float and complex can be NaN

NotificationCenter issue on Swift 3

I think it has changed again.

For posting this works in Xcode 8.2.

NotificationCenter.default.post(Notification(name:.UIApplicationWillResignActive)

The import com.google.android.gms cannot be resolved

In my case or all using android studio

you can import google play service

place in your build.gradle

compile 'com.google.android.gms:play-services:7.8.0'

or latest version of play services depend in time you watch this answer

More Specific import

please review this individual gradle imports

https://developers.google.com/android/guides/setup

Google Maps

com.google.android.gms:play-services-maps:7.8.0

error may occurred

if you face error while you sync project with gradle files

enter image description here

make sure you install latest update

1- Android Support Repository.

2- Android Support Library.

3- Google Repository.

4-Google Play Services.

enter image description here

You may need restart your android studio to response

Netbeans - Error: Could not find or load main class

Had the same problem here. Usually Clean and Build solves much of the problem. It happened to be caused by a wrongly installed plugin.

In Java what is the syntax for commenting out multiple lines?

/*
 *STUFF HERE
 */

or you can use // on every line.

Below is what is called a JavaDoc comment which allows you to use certain tags (@return, @param, etc...) for documentation purposes.

   /**
    *COMMENTED OUT STUFF HERE
    *AND HERE
    */

More information on comments and conventions can be found here.

Upgrading Node.js to latest version

Its very simple in Windows OS.

You do not have to do any uninstallation of the old node or npm or anything else.

Just go to nodejs.org

And then look for Downloads for Windows option and below that click on Current... Latest Feature Tab and follow automated instructions

It will download the latest node & npm for you & discarding the old one.

How to make modal dialog in WPF?

Did you try showing your window using the ShowDialog method?

Don't forget to set the Owner property on the dialog window to the main window. This will avoid weird behavior when Alt+Tabbing, etc.

Difference between binary tree and binary search tree

A binary tree is a tree whose children are never more than two. A binary search tree follows the invariant that the left child should have a smaller value than the root node's key, while the right child should have a greater value than the root node's key.

lexers vs parsers

What parsers and lexers have in common:

  1. They read symbols of some alphabet from their input.

    • Hint: The alphabet doesn't necessarily have to be of letters. But it has to be of symbols which are atomic for the language understood by parser/lexer.
    • Symbols for the lexer: ASCII characters.
    • Symbols for the parser: the particular tokens, which are terminal symbols of their grammar.
  2. They analyse these symbols and try to match them with the grammar of the language they understood.

    • Here's where the real difference usually lies. See below for more.
    • Grammar understood by lexers: regular grammar (Chomsky's level 3).
    • Grammar understood by parsers: context-free grammar (Chomsky's level 2).
  3. They attach semantics (meaning) to the language pieces they find.

    • Lexers attach meaning by classifying lexemes (strings of symbols from the input) as the particular tokens. E.g. All these lexemes: *, ==, <=, ^ will be classified as "operator" token by the C/C++ lexer.
    • Parsers attach meaning by classifying strings of tokens from the input (sentences) as the particular nonterminals and building the parse tree. E.g. all these token strings: [number][operator][number], [id][operator][id], [id][operator][number][operator][number] will be classified as "expression" nonterminal by the C/C++ parser.
  4. They can attach some additional meaning (data) to the recognized elements.

    • When a lexer recognizes a character sequence constituting a proper number, it can convert it to its binary value and store with the "number" token.
    • Similarly, when a parser recognize an expression, it can compute its value and store with the "expression" node of the syntax tree.
  5. They all produce on their output a proper sentences of the language they recognize.

    • Lexers produce tokens, which are sentences of the regular language they recognize. Each token can have an inner syntax (though level 3, not level 2), but that doesn't matter for the output data and for the one which reads them.
    • Parsers produce syntax trees, which are representations of sentences of the context-free language they recognize. Usually it's only one big tree for the whole document/source file, because the whole document/source file is a proper sentence for them. But there aren't any reasons why parser couldn't produce a series of syntax trees on its output. E.g. it could be a parser which recognizes SGML tags sticked into plain-text. So it'll tokenize the SGML document into a series of tokens: [TXT][TAG][TAG][TXT][TAG][TXT]....

As you can see, parsers and tokenizers have much in common. One parser can be a tokenizer for other parser, which reads its input tokens as symbols from its own alphabet (tokens are simply symbols of some alphabet) in the same way as sentences from one language can be alphabetic symbols of some other, higher-level language. For example, if * and - are the symbols of the alphabet M (as "Morse code symbols"), then you can build a parser which recognizes strings of these dots and lines as letters encoded in the Morse code. The sentences in the language "Morse Code" could be tokens for some other parser, for which these tokens are atomic symbols of its language (e.g. "English Words" language). And these "English Words" could be tokens (symbols of the alphabet) for some higher-level parser which understands "English Sentences" language. And all these languages differ only in the complexity of the grammar. Nothing more.

So what's all about these "Chomsky's grammar levels"? Well, Noam Chomsky classified grammars into four levels depending on their complexity:

  • Level 3: Regular grammars

    They use regular expressions, that is, they can consist only of the symbols of alphabet (a,b), their concatenations (ab,aba,bbb etd.), or alternatives (e.g. a|b).
    They can be implemented as finite state automata (FSA), like NFA (Nondeterministic Finite Automaton) or better DFA (Deterministic Finite Automaton).
    Regular grammars can't handle with nested syntax, e.g. properly nested/matched parentheses (()()(()())), nested HTML/BBcode tags, nested blocks etc. It's because state automata to deal with it should have to have infinitely many states to handle infinitely many nesting levels.
  • Level 2: Context-free grammars

    They can have nested, recursive, self-similar branches in their syntax trees, so they can handle with nested structures well.
    They can be implemented as state automaton with stack. This stack is used to represent the nesting level of the syntax. In practice, they're usually implemented as a top-down, recursive-descent parser which uses machine's procedure call stack to track the nesting level, and use recursively called procedures/functions for every non-terminal symbol in their syntax.
    But they can't handle with a context-sensitive syntax. E.g. when you have an expression x+3 and in one context this x could be a name of a variable, and in other context it could be a name of a function etc.
  • Level 1: Context-sensitive grammars

  • Level 0: Unrestricted grammars
    Also called recursively enumerable grammars.

Remote JMX connection

http://blogs.oracle.com/jmxetc/entry/troubleshooting_connection_problems_in_jconsole

If you are trying to access a server which is behind a NAT - you will most probably have to start your server with the option

-Djava.rmi.server.hostname=<public/NAT address>

so that the RMI stubs sent to the client contain the server's public address allowing it to be reached by the clients from the outside.

Send FormData and String Data Together Through JQuery AJAX?

well, as an easier alternative and shorter, you could do this too!!

var fd = new FormData();

var file_data = object.get(0).files[i];
var other_data = $('form').serialize(); //page_id=&category_id=15&method=upload&required%5Bcategory_id%5D=Category+ID

fd.append("file", file_data);

$.ajax({
    url: 'add.php?'+ other_data,  //<== just add it to the end of url ***
    data: fd,
    contentType: false,
    processData: false,
    type: 'POST',
    success: function(data){
        alert(data);
    }
});

How to add a reference programmatically

Here is how to get the Guid's programmatically! You can then use these guids/filepaths with an above answer to add the reference!

Reference: http://www.vbaexpress.com/kb/getarticle.php?kb_id=278

Sub ListReferencePaths()
'Lists path and GUID (Globally Unique Identifier) for each referenced library.
'Select a reference in Tools > References, then run this code to get GUID etc.
    Dim rw As Long, ref
    With ThisWorkbook.Sheets(1)
        .Cells.Clear
        rw = 1
        .Range("A" & rw & ":D" & rw) = Array("Reference","Version","GUID","Path")
        For Each ref In ThisWorkbook.VBProject.References
            rw = rw + 1
            .Range("A" & rw & ":D" & rw) = Array(ref.Description, _
                   "v." & ref.Major & "." & ref.Minor, ref.GUID, ref.FullPath)
        Next ref
        .Range("A:D").Columns.AutoFit
    End With
End Sub

Here is the same code but printing to the terminal if you don't want to dedicate a worksheet to the output.

Sub ListReferencePaths() 
 'Macro purpose:  To determine full path and Globally Unique Identifier (GUID)
 'to each referenced library.  Select the reference in the Tools\References
 'window, then run this code to get the information on the reference's library

On Error Resume Next 
Dim i As Long 

Debug.Print "Reference name" & " | " & "Full path to reference" & " | " & "Reference GUID" 

For i = 1 To ThisWorkbook.VBProject.References.Count 
  With ThisWorkbook.VBProject.References(i) 
    Debug.Print .Name & " | " & .FullPath  & " | " & .GUID 
  End With 
Next i 
On Error GoTo 0 
End Sub 

Filename timestamp in Windows CMD batch script getting truncated

It wants the full time in DD-MM-YYYY_HH-MM-SS.TT where TT is the ticks. The exception says it all.

python, sort descending dataframe with pandas

New syntax (either):

 test = df.sort_values(['one'], ascending=[False])
 test = df.sort_values(['one'], ascending=[0])

How can I delete one element from an array by value

Assuming you want to delete 3 by value at multiple places in an array, I think the ruby way to do this task would be to use the delete_if method:

[2,4,6,3,8,3].delete_if {|x| x == 3 } 

You can also use delete_if in removing elements in the scenario of 'array of arrays'.

Hope this resolves your query

Multiline text in JLabel

String labelText ="<html>Name :"+name+"<br>Surname :"+surname+"<br>Gender :"+gender+"</html>";
JLabel label=new JLabel(labelText);
label.setVisible(true);
label.setBounds(10, 10,300, 100);
dialog.add(label);

Swing JLabel text change on the running application

Use setText(str) method of JLabel to dynamically change text displayed. In actionPerform of button write this:

jLabel.setText("new Value");

A simple demo code will be:

    JFrame frame = new JFrame("Demo");
    frame.setLayout(new BorderLayout());
    frame.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
    frame.setSize(250,100);

    final JLabel label = new JLabel("flag");
    JButton button = new JButton("Change flag");
    button.addActionListener(new ActionListener() {
        @Override
        public void actionPerformed(ActionEvent arg0) {
            label.setText("new value");
        }
    });

    frame.add(label, BorderLayout.NORTH);
    frame.add(button, BorderLayout.CENTER);
    frame.setVisible(true);

Failed to install android-sdk: "java.lang.NoClassDefFoundError: javax/xml/bind/annotation/XmlSchema"

Strangely Java9 is not compatible with android-sdk

$ avdmanager
Exception in thread "main" java.lang.NoClassDefFoundError: javax/xml/bind/annotation/XmlSchema
    at com.android.repository.api.SchemaModule$SchemaModuleVersion.<init>(SchemaModule.java:156)
    at com.android.repository.api.SchemaModule.<init>(SchemaModule.java:75)
    at com.android.sdklib.repository.AndroidSdkHandler.<clinit>(AndroidSdkHandler.java:81)
    at com.android.sdklib.tool.AvdManagerCli.run(AvdManagerCli.java:213)
    at com.android.sdklib.tool.AvdManagerCli.main(AvdManagerCli.java:200)
Caused by: java.lang.ClassNotFoundException: javax.xml.bind.annotation.XmlSchema
    at java.base/jdk.internal.loader.BuiltinClassLoader.loadClass(BuiltinClassLoader.java:582)
    at java.base/jdk.internal.loader.ClassLoaders$AppClassLoader.loadClass(ClassLoaders.java:185)
    at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:496)
    ... 5 more

Combined all commands into one for easy reference:

$ sudo rm -fr /Library/Java/JavaVirtualMachines/jdk-9*.jdk/
$ sudo rm -fr /Library/Internet\ Plug-Ins/JavaAppletPlugin.plugin
$ sudo rm -fr /Library/PreferencePanes/JavaControlPanel.prefPane

$ /usr/libexec/java_home -V
Unable to find any JVMs matching version "(null)".
Matching Java Virtual Machines (0):
Default Java Virtual Machines (0):
No Java runtime present, try --request to install

$ brew tap caskroom/versions
$ brew cask install java8
$ touch ~/.android/repositories.cfg
$ brew cask install android-sdk
$ echo 'export ANDROID_SDK_ROOT="/usr/local/share/android-sdk"' >> ~/.bash_profile
$ java -version
java version "1.8.0_162"
Java(TM) SE Runtime Environment (build 1.8.0_162-b12)
Java HotSpot(TM) 64-Bit Server VM (build 25.162-b12, mixed mode)
$ avdmanager

Usage:
      avdmanager [global options] [action] [action options]
      Global options:
  -s --silent     : Silent mode, shows errors only.
  -v --verbose    : Verbose mode, shows errors, warnings and all messages.
     --clear-cache: Clear the SDK Manager repository manifest cache.
  -h --help       : Help on a specific command.

Valid actions are composed of a verb and an optional direct object:
-   list              : Lists existing targets or virtual devices.
-   list avd          : Lists existing Android Virtual Devices.
-   list target       : Lists existing targets.
-   list device       : Lists existing devices.
- create avd          : Creates a new Android Virtual Device.
-   move avd          : Moves or renames an Android Virtual Device.
- delete avd          : Deletes an Android Virtual Device.

Setting property 'source' to 'org.eclipse.jst.jee.server:JSFTut' did not find a matching property

In regards to setting the logging.properties value

org.apache.tomcat.util.digester.Digester.level = SEVERE

... if you're running an embedded tomcat server in eclipse, the logging.properties file used by default is the JDK default at %JAVA_HOME%/jre/lib/logging.properties

If you want to use a different logging.properties file (e.g. in the tomcat server's conf directory), this needs to be set via the java.util.logging.config.file system property. e.g. to use the logging properties defined in the file c:\java\apache-tomcat-7.0.54\conf\eclipse-logging.properties, add this to the VM argument list:

-Djava.util.logging.config.file="c:\java\apache-tomcat-7.0.54\conf\eclipse-logging.properties"

(double-click on the server icon, click 'Open launch configuration', select the Arguments tab, then enter this in the 'VM arguments' text box)

You might also find it useful to add the VM argument

-Djava.util.logging.SimpleFormatter.format="%1$tc %4$s %3$s %5$s%n"

as well, which will then include the source logger name in the output, which should make it easier to determine which logger to throttle in the logging.properties file (as per http://docs.oracle.com/javase/7/docs/api/java/util/logging/SimpleFormatter.html )

AJAX jQuery refresh div every 5 seconds

Try using setInterval and include jquery library and just try removing unwrap()

<script src="http://code.jquery.com/jquery-latest.min.js" type="text/javascript"></script>
<script language="javascript" type="text/javascript">

var timeout = setInterval(reloadChat, 5000);    
function reloadChat () {

     $('#links').load('test.php');
}
</script>

UPDATE

you are using a jquery old version so include the latest jquery version

<script src="http://code.jquery.com/jquery-latest.min.js" type="text/javascript"></script>

How do I open a Visual Studio project in design view?

Click on the form in the Solution Explorer

Create SQL script that create database and tables

Yes, you can add as many SQL statements into a single script as you wish. Just one thing to note: the order matters. You can't INSERT into a table until you CREATE it; you can't set a foreign key until the primary key is inserted.

How to reset sequence in postgres and fill id column with new data?

Inspired by the other answers here, I created an SQL function to do a sequence migration. The function moves a primary key sequence to a new contiguous sequence starting with any value (>= 1) either inside or outside the existing sequence range.

I explain here how I used this function in a migration of two databases with the same schema but different values into one database.

First, the function (which prints the generated SQL commands so that it is clear what is actually happening):

CREATE OR REPLACE FUNCTION migrate_pkey_sequence
  ( arg_table      text
  , arg_column     text
  , arg_sequence   text
  , arg_next_value bigint  -- Must be >= 1
  )
RETURNS int AS $$
DECLARE
  result int;
  curr_value bigint = arg_next_value - 1;
  update_column1 text := format
    ( 'UPDATE %I SET %I = nextval(%L) + %s'
    , arg_table
    , arg_column
    , arg_sequence
    , curr_value
    );
  alter_sequence text := format
    ( 'ALTER SEQUENCE %I RESTART WITH %s'
    , arg_sequence
    , arg_next_value
    );
  update_column2 text := format
    ( 'UPDATE %I SET %I = DEFAULT'
    , arg_table
    , arg_column
    );
  select_max_column text := format
    ( 'SELECT coalesce(max(%I), %s) + 1 AS nextval FROM %I'
    , arg_column
    , curr_value
    , arg_table
    );
BEGIN
  -- Print the SQL command before executing it.
  RAISE INFO '%', update_column1;
  EXECUTE update_column1;
  RAISE INFO '%', alter_sequence;
  EXECUTE alter_sequence;
  RAISE INFO '%', update_column2;
  EXECUTE update_column2;
  EXECUTE select_max_column INTO result;
  RETURN result;
END $$ LANGUAGE plpgsql;

The function migrate_pkey_sequence takes the following arguments:

  1. arg_table: table name (e.g. 'example')
  2. arg_column: primary key column name (e.g. 'id')
  3. arg_sequence: sequence name (e.g. 'example_id_seq')
  4. arg_next_value: next value for the column after migration

It performs the following operations:

  1. Move the primary key values to a free range. I assume that nextval('example_id_seq') follows max(id) and that the sequence starts with 1. This also handles the case where arg_next_value > max(id).
  2. Move the primary key values to the contiguous range starting with arg_next_value. The order of key values are preserved but holes in the range are not preserved.
  3. Print the next value that would follow in the sequence. This is useful if you want to migrate the columns of another table and merge with this one.

To demonstrate, we use a sequence and table defined as follows (e.g. using psql):

# CREATE SEQUENCE example_id_seq
  START WITH 1
  INCREMENT BY 1
  NO MINVALUE
  NO MAXVALUE
  CACHE 1;
# CREATE TABLE example
  ( id bigint NOT NULL DEFAULT nextval('example_id_seq'::regclass)
  );

Then, we insert some values (starting, for example, at 3):

# ALTER SEQUENCE example_id_seq RESTART WITH 3;
# INSERT INTO example VALUES (DEFAULT), (DEFAULT), (DEFAULT);
-- id: 3, 4, 5

Finally, we migrate the example.id values to start with 1.

# SELECT migrate_pkey_sequence('example', 'id', 'example_id_seq', 1);
INFO:  00000: UPDATE example SET id = nextval('example_id_seq') + 0
INFO:  00000: ALTER SEQUENCE example_id_seq RESTART WITH 1
INFO:  00000: UPDATE example SET id = DEFAULT
 migrate_pkey_sequence
-----------------------
                     4
(1 row)

The result:

# SELECT * FROM example;
 id
----
  1
  2
  3
(3 rows)

undefined offset PHP error

Undefined offset means there's an empty array key for example:

$a = array('Felix','Jon','Java');

// This will result in an "Undefined offset" because the size of the array
// is three (3), thus, 0,1,2 without 3
echo $a[3];

You can solve the problem using a loop (while):

$i = 0;
while ($row = mysqli_fetch_assoc($result)) {
    // Increase count by 1, thus, $i=1
    $i++;

    $groupname[$i] = base64_decode(base64_decode($row['groupname']));

    // Set the first position of the array to null or empty
    $groupname[0] = "";
}

How to replace list item in best way

Use FindIndex and lambda to find and replace your values:

int j = listofelements.FindIndex(i => i.Contains(valueFieldValue.ToString())); //Finds the item index

lstString[j] = lstString[j].Replace(valueFieldValue.ToString(), value.ToString()); //Replaces the item by new value

how to replace characters in hive?

regexp_replace UDF performs my task. Below is the definition and usage from apache Wiki.

regexp_replace(string INITIAL_STRING, string PATTERN, string REPLACEMENT):

This returns the string resulting from replacing all substrings in INITIAL_STRING that match the java regular expression syntax defined in PATTERN with instances of REPLACEMENT,

e.g.: regexp_replace("foobar", "oo|ar", "") returns fb

Command-line Tool to find Java Heap Size and Memory Used (Linux)?

First get the process id, the first number from the process listed, from one of the following: (or just use ps aux | grep java, if you prefer that)

jps -lvm

Then use the process ID here:

jmap -heap $MY_PID 2>/dev/null | sed -ne '/Heap Configuration/,$p';
jmap -permstat $MY_PID

How to make an element width: 100% minus padding?

You can do it without using box-sizing and not clear solutions like width~=99%.

Demo on jsFiddle:
enter image description here

  • Keep input's padding and border
  • Add to input negative horizontal margin = border-width + horizontal padding
  • Add to input's wrapper horizontal padding equal to margin from previous step

HTML markup:

<div class="input_wrap">
    <input type="text" />
</div>

CSS:

div {
    padding: 6px 10px; /* equal to negative input's margin for mimic normal `div` box-sizing */
}

input {
    width: 100%; /* force to expand to container's width */ 
    padding: 5px 10px;
    border: none;
    margin: 0 -10px; /* negative margin = border-width + horizontal padding */ 
}

Efficient way to do batch INSERTS with JDBC

The Statement gives you the following option:

Statement stmt = con.createStatement();

stmt.addBatch("INSERT INTO employees VALUES (1000, 'Joe Jones')");
stmt.addBatch("INSERT INTO departments VALUES (260, 'Shoe')");
stmt.addBatch("INSERT INTO emp_dept VALUES (1000, 260)");

// submit a batch of update commands for execution
int[] updateCounts = stmt.executeBatch();

jQuery, simple polling example

function doPoll(){
    $.post('ajax/test.html', function(data) {
        alert(data);  // process results here
        setTimeout(doPoll,5000);
    });
}

Firebase: how to generate a unique numeric ID for key?

As the docs say, this can be achieved just by using set instead if push.

As the docs say, it is not recommended (due to possible overwrite by other user at the "same" time).

But in some cases it's helpful to have control over the feed's content including keys.

As an example of webapp in js, 193 being your id generated elsewhere, simply:

 firebase.initializeApp(firebaseConfig);
  var data={
      "name":"Prague"
  };
  firebase.database().ref().child('areas').child("193").set(data);

This will overwrite any area labeled 193 or create one if it's not existing yet.

Warning: The method assertEquals from the type Assert is deprecated

this method also encounter a deprecate warning:

org.junit.Assert.assertEquals(float expected,float actual) //deprecated

It is because currently junit prefer a third parameter rather than just two float variables input.

The third parameter is delta:

public static void assertEquals(double expected,double actual,double delta) //replacement

this is mostly used to deal with inaccurate Floating point calculations

for more information, please refer this problem: Meaning of epsilon argument of assertEquals for double values

get specific row from spark dataframe

There is a scala way (if you have a enough memory on working machine):

val arr = df.select("column").rdd.collect
println(arr(100))

If dataframe schema is unknown, and you know actual type of "column" field (for example double), than you can get arr as following:

val arr = df.select($"column".cast("Double")).as[Double].rdd.collect

Add a string of text into an input field when user clicks a button

Don't forget to keep the input field on focus for future typing with input.focus(); inside the function.

denied: requested access to the resource is denied : docker

I got the same issue while taking the docker beginner Course. I solved the issue by doing adocker login before the docker push call.

How do I search for files in Visual Studio Code?

I'm using VSCode 1.12.1

OSX press : Cmd + p

How can I get the current page's full URL on a Windows/IIS server?

Reverse Proxy Support!

Something a little more robust. Note It'll only work on 5.3 or greater.

/*
 * Compatibility with multiple host headers.
 * Support of "Reverse Proxy" configurations.
 *
 * Michael Jett <[email protected]>
 */

function base_url() {

    $protocol = @$_SERVER['HTTP_X_FORWARDED_PROTO'] 
              ?: @$_SERVER['REQUEST_SCHEME']
              ?: ((isset($_SERVER["HTTPS"]) && $_SERVER["HTTPS"] == "on") ? "https" : "http");

    $port = @intval($_SERVER['HTTP_X_FORWARDED_PORT'])
          ?: @intval($_SERVER["SERVER_PORT"])
          ?: (($protocol === 'https') ? 443 : 80);

    $host = @explode(":", $_SERVER['HTTP_HOST'])[0]
          ?: @$_SERVER['SERVER_NAME']
          ?: @$_SERVER['SERVER_ADDR'];

    // Don't include port if it's 80 or 443 and the protocol matches
    $port = ($protocol === 'https' && $port === 443) || ($protocol === 'http' && $port === 80) ? '' : ':' . $port;

    return sprintf('%s://%s%s/%s', $protocol, $host, $port, @trim(reset(explode("?", $_SERVER['REQUEST_URI'])), '/'));
}

Comparing strings in Java

In onclik function replace first line with this line u will definitely get right result.

if (passw1.getText().toString().equalsIgnoreCase("1234") && passw2.getText().toString().equalsIgnoreCase("1234")){

JRE 1.7 - java version - returns: java/lang/NoClassDefFoundError: java/lang/Object

Go to control panel, uninstall the java related stuff(close eclipse if opened), then re-install java and open eclipse, clean projects.

is there a css hack for safari only NOT chrome?

There is a way to filter Safari 5+ from Chrome:

@media screen and (-webkit-min-device-pixel-ratio:0) { 
    /* Safari and Chrome */
    .myClass {
     color:red;
    }

    /* Safari only override */
    ::i-block-chrome,.myClass {
     color:blue;
    }
}

Why must wait() always be in synchronized block

What is the potential damage if it was possible to invoke wait() outside a synchronized block, retaining it's semantics - suspending the caller thread?

Let's illustrate what issues we would run into if wait() could be called outside of a synchronized block with a concrete example.

Suppose we were to implement a blocking queue (I know, there is already one in the API :)

A first attempt (without synchronization) could look something along the lines below

class BlockingQueue {
    Queue<String> buffer = new LinkedList<String>();

    public void give(String data) {
        buffer.add(data);
        notify();                   // Since someone may be waiting in take!
    }

    public String take() throws InterruptedException {
        while (buffer.isEmpty())    // don't use "if" due to spurious wakeups.
            wait();
        return buffer.remove();
    }
}

This is what could potentially happen:

  1. A consumer thread calls take() and sees that the buffer.isEmpty().

  2. Before the consumer thread goes on to call wait(), a producer thread comes along and invokes a full give(), that is, buffer.add(data); notify();

  3. The consumer thread will now call wait() (and miss the notify() that was just called).

  4. If unlucky, the producer thread won't produce more give() as a result of the fact that the consumer thread never wakes up, and we have a dead-lock.

Once you understand the issue, the solution is obvious: Use synchronized to make sure notify is never called between isEmpty and wait.

Without going into details: This synchronization issue is universal. As Michael Borgwardt points out, wait/notify is all about communication between threads, so you'll always end up with a race condition similar to the one described above. This is why the "only wait inside synchronized" rule is enforced.


A paragraph from the link posted by @Willie summarizes it quite well:

You need an absolute guarantee that the waiter and the notifier agree about the state of the predicate. The waiter checks the state of the predicate at some point slightly BEFORE it goes to sleep, but it depends for correctness on the predicate being true WHEN it goes to sleep. There's a period of vulnerability between those two events, which can break the program.

The predicate that the producer and consumer need to agree upon is in the above example buffer.isEmpty(). And the agreement is resolved by ensuring that the wait and notify are performed in synchronized blocks.


This post has been rewritten as an article here: Java: Why wait must be called in a synchronized block

Is there a rule-of-thumb for how to divide a dataset into training and validation sets?

It all depends on the data at hand. If you have considerable amount of data then 80/20 is a good choice as mentioned above. But if you do not Cross-Validation with a 50/50 split might help you a lot more and prevent you from creating a model over-fitting your training data.

HTML table sort

Here is another library.

Changes required are -

  1. Add sorttable js

  2. Add class name sortable to table.

Click the table headers to sort the table accordingly:

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<script src="https://www.kryogenix.org/code/browser/sorttable/sorttable.js"></script>

<table class="sortable">
  <tr>
    <th>Name</th>
    <th>Address</th>
    <th>Sales Person</th>
  </tr>

  <tr class="item">
    <td>user:0001</td>
    <td>UK</td>
    <td>Melissa</td>
  </tr>
  <tr class="item">
    <td>user:0002</td>
    <td>France</td>
    <td>Justin</td>
  </tr>
  <tr class="item">
    <td>user:0003</td>
    <td>San Francisco</td>
    <td>Judy</td>
  </tr>
  <tr class="item">
    <td>user:0004</td>
    <td>Canada</td>
    <td>Skipper</td>
  </tr>
  <tr class="item">
    <td>user:0005</td>
    <td>Christchurch</td>
    <td>Alex</td>
  </tr>

</table>
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_x000D_

How to construct a WebSocket URI relative to the page URI?

Assuming your WebSocket server is listening on the same port as from which the page is being requested, I would suggest:

function createWebSocket(path) {
    var protocolPrefix = (window.location.protocol === 'https:') ? 'wss:' : 'ws:';
    return new WebSocket(protocolPrefix + '//' + location.host + path);
}

Then, for your case, call it as follows:

var socket = createWebSocket(location.pathname + '/to/ws');

How to create a Date in SQL Server given the Day, Month and Year as Integers

The following code should work on all versions of sql server I believe:

SELECT CAST(CONCAT(CAST(@Year AS VARCHAR(4)), '-',CAST(@Month AS VARCHAR(2)), '-',CAST(@Day AS VARCHAR(2))) AS DATE)

In MySQL, how to copy the content of one table to another table within the same database?

If table1 is large and you don't want to lock it for the duration of the copy process, you can do a dump-and-load instead:

CREATE TABLE table2 LIKE table1;

SELECT * INTO OUTFILE '/tmp/table1.txt' FROM table1;
LOAD DATA INFILE '/tmp/table1.txt' INTO TABLE table2;

How to underline a UILabel in swift?

You can use this also if you want to achieve only half part of label as underline:- //For Swift 4.0+

let attributesForUnderLine: [NSAttributedString.Key: Any] = [
            .font: UIFont(name: AppFont.sourceSansPro_Regular, size: 12) ?? UIFont.systemFont(ofSize: 11),
            .foregroundColor: UIColor.blue,
            .underlineStyle: NSUnderlineStyle.single.rawValue]

        let attributesForNormalText: [NSAttributedString.Key: Any] = [
            .font: UIFont(name: AppFont.sourceSansPro_Regular, size: 12) ?? UIFont.systemFont(ofSize: 11),
            .foregroundColor: AppColors.ColorText_787878]

        let textToSet = "Want to change your preferences? Edit Now"
        let rangeOfUnderLine = (textToSet as NSString).range(of: "Edit Now")
        let rangeOfNormalText = (textToSet as NSString).range(of: "Want to change your preferences?")

        let attributedText = NSMutableAttributedString(string: textToSet)
        attributedText.addAttributes(attributesForUnderLine, range: rangeOfUnderLine)
        attributedText.addAttributes(attributesForNormalText, range: rangeOfNormalText)
        yourLabel.attributedText = attributedText

Find character position and update file name

If you split the filename on underscore and dot, you get an array of 3 strings. Join the first and third string, i.e. with index 0 and 2

$x = '237801_201011221155.xml' 
( $x.split('_.')[0] , $x.split('_.')[2] ) -join '.' 

Another way to do the same thing:

'237801_201011221155.xml'.split('_.')[0,2] -join '.'

Android studio, gradle and NDK

With the update of Android Studio to 1.0, the NDK toolchain support improved immensely (note: please read my updates at the bottom of this post to see usage with the new experimental Gradle plugin and Android Studio 1.5).

Android Studio and the NDK are integrated well enough so that you just need to create an ndk{} block in your module's build.gradle, and set your source files into the (module)/src/main/jni directory - and you're done!

No more ndk-build from the command line.

I've written all about it in my blog post here: http://www.sureshjoshi.com/mobile/android-ndk-in-android-studio-with-swig/

The salient points are:

There are two things you need to know here. By default, if you have external libs that you want loaded into the Android application, they are looked for in the (module)/src/main/jniLibs by default. You can change this by using setting sourceSets.main.jniLibs.srcDirs in your module’s build.gradle. You’ll need a subdirectory with libraries for each architecture you’re targeting (e.g. x86, arm, mips, arm64-v8a, etc…)

The code you want to be compiled by default by the NDK toolchain will be located in (module)/src/main/jni and similarly to above, you can change it by setting sourceSets.main.jni.srcDirs in your module’s build.gradle

and put this into your module's build.gradle:

ndk {
  moduleName "SeePlusPlus" // Name of C++ module (i.e. libSeePlusPlus)
  cFlags "-std=c++11 -fexceptions" // Add provisions to allow C++11 functionality
  stl "gnustl_shared" // Which STL library to use: gnustl or stlport
}

That's the process of compiling your C++ code, from there you need to load it, and create wrappers - but judging from your question, you already know how to do all that, so I won't re-hash.

Also, I've placed a Github repo of this example here: http://github.com/sureshjoshi/android-ndk-swig-example

UPDATE: June 14, 2015

When Android Studio 1.3 comes out, there should be better support for C++ through the JetBrains CLion plugin. I'm currently under the assumption that this will allow Java and C++ development from within Android Studio; however I think we'll still need to use the Gradle NDK section as I've stated above. Additionally, I think there will still be the need to write Java<->C++ wrapper files, unless CLion will do those automatically.

UPDATE: January 5, 2016

I have updated my blog and Github repo (in the develop branch) to use Android Studio 1.5 with the latest experimental Gradle plugin (0.6.0-alpha3).

http://www.sureshjoshi.com/mobile/android-ndk-in-android-studio-with-swig/ http://github.com/sureshjoshi/android-ndk-swig-example

The Gradle build for the NDK section now looks like this:

android.ndk {
    moduleName = "SeePlusPlus" // Name of C++ module (i.e. libSeePlusPlus)
    cppFlags.add("-std=c++11") // Add provisions to allow C++11 functionality
    cppFlags.add("-fexceptions")
    stl = "gnustl_shared" // Which STL library to use: gnustl or stlport
}

Also, quite awesomely, Android Studio has auto-complete for C++-Java generated wrappers using the 'native' keyword:

Example of auto-complete of C++-Java wrapper

However, it's not completely rosy... If you're using SWIG to wrap a library to auto-generate code, and then try to use the native keyword auto-generation, it will put the code in the wrong place in your Swig _wrap.cxx file... So you need to move it into the "extern C" block:

C++-Java wrapper moved to correct location

UPDATE: October 15, 2017

I'd be remiss if I didn't mention that Android Studio 2.2 onwards has essentially 'native' (no pun) support for the NDK toolchain via Gradle and CMake. Now, when you create a new project, just select C++ support and you're good to go.

You'll still need to generate your own JNI layer code, or use the SWIG technique I've mentioned above, but the scaffolding of a C++ in Android project is trivial now.

Changes in the CMakeLists file (which is where you place your C++ source files) will be picked up by Android Studio, and it'll automatically re-compile any associated libraries.

Command line for looking at specific port

For port 80, the command would be : netstat -an | find "80" For port n, the command would be : netstat -an | find "n"

Here, netstat is the instruction to your machine

-a : Displays all connections and listening ports -n : Displays all address and instructions in numerical format (This is required because output from -a can contain machine names)

Then, a find command to "Pattern Match" the output of previous command.

Get file size, image width and height before upload

A working jQuery validate example:

   $(function () {
        $('input[type=file]').on('change', function() {
            var $el = $(this);
            var files = this.files;
            var image = new Image();
            image.onload = function() {
                $el
                    .attr('data-upload-width', this.naturalWidth)
                    .attr('data-upload-height', this.naturalHeight);
            }

            image.src = URL.createObjectURL(files[0]);
        });

        jQuery.validator.unobtrusive.adapters.add('imageminwidth', ['imageminwidth'], function (options) {
            var params = {
                imageminwidth: options.params.imageminwidth.split(',')
            };

            options.rules['imageminwidth'] = params;
            if (options.message) {
                options.messages['imageminwidth'] = options.message;
            }
        });

        jQuery.validator.addMethod("imageminwidth", function (value, element, param) {
            var $el = $(element);
            if(!element.files && element.files[0]) return true;
            return parseInt($el.attr('data-upload-width')) >=  parseInt(param["imageminwidth"][0]);
        });

    } (jQuery));

load external URL into modal jquery ui dialog

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_x000D_
if you are using **Bootstrap** this is solution, _x000D_
_x000D_
$(document).ready(function(e) {_x000D_
    $('.bootpopup').click(function(){_x000D_
  var frametarget = $(this).attr('href');_x000D_
  targetmodal = '#myModal'; _x000D_
        $('#modeliframe').attr("src", frametarget );   _x000D_
});_x000D_
});
_x000D_
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>_x000D_
<!-- Latest compiled and minified CSS -->_x000D_
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css" integrity="sha384-BVYiiSIFeK1dGmJRAkycuHAHRg32OmUcww7on3RYdg4Va+PmSTsz/K68vbdEjh4u" crossorigin="anonymous">_x000D_
_x000D_
<!-- Optional theme -->_x000D_
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap-theme.min.css" integrity="sha384-rHyoN1iRsVXV4nD0JutlnGaslCJuC7uwjduW9SVrLvRYooPp2bWYgmgJQIXwl/Sp" crossorigin="anonymous">_x000D_
_x000D_
<!-- Latest compiled and minified JavaScript -->_x000D_
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/js/bootstrap.min.js" integrity="sha384-Tc5IQib027qvyjSMfHjOMaLkfuWVxZxUPnCJA7l2mCWNIpG9mGCD8wGNIcPD7Txa" crossorigin="anonymous"></script>_x000D_
<!-- Button trigger modal -->_x000D_
<a  href="http://twitter.github.io/bootstrap/" title="Edit Transaction" class="btn btn-primary btn-lg bootpopup" data-toggle="modal" data-target="#myModal">_x000D_
  Launch demo modal_x000D_
</a>_x000D_
_x000D_
<!-- Modal -->_x000D_
<div class="modal fade" id="myModal" tabindex="-1" role="dialog" aria-labelledby="myModalLabel">_x000D_
  <div class="modal-dialog" role="document">_x000D_
    <div class="modal-content">_x000D_
      <div class="modal-header">_x000D_
        <button type="button" class="close" data-dismiss="modal" aria-label="Close"><span aria-hidden="true">&times;</span></button>_x000D_
        <h4 class="modal-title" id="myModalLabel">Modal title</h4>_x000D_
      </div>_x000D_
      <div class="modal-body">_x000D_
         <iframe src="" id="modeliframe" style="zoom:0.60" frameborder="0" height="250" width="99.6%"></iframe>_x000D_
      </div>_x000D_
      <div class="modal-footer">_x000D_
        <button type="button" class="btn btn-default" data-dismiss="modal">Close</button>_x000D_
        <button type="button" class="btn btn-primary">Save changes</button>_x000D_
      </div>_x000D_
    </div>_x000D_
  </div>_x000D_
</div>
_x000D_
_x000D_
_x000D_

how to convert a string to a bool

Quite simple indeed:

bool b = str == "1";

UITableView load more when scrolling to bottom like Facebook application

Just wanna share this approach:

- (void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView
{
    NSLog(@"%@", [[YourTableView indexPathsForVisibleRows] lastObject]);
    [self estimatedTotalData];
}

- (void)estimatedTotalData
{
    long currentRow = ((NSIndexPath *)[[YourTableView indexPathsForVisibleRows] lastObject]).row;

    long estimateDataCount = 25;

    while (currentRow > estimateDataCount)
    {
        estimateDataCount+=25;
    }

    dataLimit = estimateDataCount;

    if (dataLimit == currentRow+1)
    {
        dataLimit+=25;
    }

    NSLog(@"dataLimit :%ld", dataLimit);

    [self requestForData];

    // this answers the question..
    //
    if(YourDataSource.count-1 == currentRow)
    {
        NSLog(@"LAST ROW"); //loadMore data
    }
}

NSLog(...); output would be something like:

<NSIndexPath: 0xc0000000002e0016> {length = 2, path = 0 - 92}
dataLimit :100
<NSIndexPath: 0xc000000000298016> {length = 2, path = 0 - 83}
dataLimit :100
<NSIndexPath: 0xc000000000278016> {length = 2, path = 0 - 79}
dataLimit :100
<NSIndexPath: 0xc000000000238016> {length = 2, path = 0 - 71}
dataLimit :75
<NSIndexPath: 0xc0000000001d8016> {length = 2, path = 0 - 59}
dataLimit :75
<NSIndexPath: 0xc0000000001c0016> {length = 2, path = 0 - 56}
dataLimit :75
<NSIndexPath: 0xc000000000138016> {length = 2, path = 0 - 39}
dataLimit :50
<NSIndexPath: 0xc000000000120016> {length = 2, path = 0 - 36}
dataLimit :50
<NSIndexPath: 0xc000000000008016> {length = 2, path = 0 - 1}
dataLimit :25
<NSIndexPath: 0xc000000000008016> {length = 2, path = 0 - 1}
dataLimit :25

This is good for displaying data stored locally. Initially I declare the dataLimit to 25, that means uitableview will have 0-24 (initially).

If the user scrolled to the bottom and the last cell is visible dataLimit will be added with 25...

Note: This is more like a UITableView data paging, :)

How to find whether MySQL is installed in Red Hat?

rpmquery <package Name> By this command you can check which package is installed.

For Example: rpmquery mysql

Python Requests and persistent sessions

Save only required cookies and reuse them.

import os
import pickle
from urllib.parse import urljoin, urlparse

login = '[email protected]'
password = 'secret'
# Assuming two cookies are used for persistent login.
# (Find it by tracing the login process)
persistentCookieNames = ['sessionId', 'profileId']
URL = 'http://example.com'
urlData = urlparse(URL)
cookieFile = urlData.netloc + '.cookie'
signinUrl = urljoin(URL, "/signin")
with requests.Session() as session:
    try:
        with open(cookieFile, 'rb') as f:
            print("Loading cookies...")
            session.cookies.update(pickle.load(f))
    except Exception:
        # If could not load cookies from file, get the new ones by login in
        print("Login in...")
        post = session.post(
            signinUrl,
            data={
                'email': login,
                'password': password,
            }
        )
        try:
            with open(cookieFile, 'wb') as f:
                jar = requests.cookies.RequestsCookieJar()
                for cookie in session.cookies:
                    if cookie.name in persistentCookieNames:
                        jar.set_cookie(cookie)
                pickle.dump(jar, f)
        except Exception as e:
            os.remove(cookieFile)
            raise(e)
    MyPage = urljoin(URL, "/mypage")
    page = session.get(MyPage)

Test if number is odd or even

I did a bit of testing, and found that between mod, is_int and the &-operator, mod is the fastest, followed closely by the &-operator. is_int is nearly 4 times slower than mod.

I used the following code for testing purposes:

$number = 13;

$before = microtime(true);
for ($i=0; $i<100000; $i++) {
    $test = ($number%2?true:false);
}
$after = microtime(true);

echo $after-$before." seconds mod<br>";

$before = microtime(true);
for ($i=0; $i<100000; $i++) {
    $test = (!is_int($number/2)?true:false);
}
$after = microtime(true);

echo $after-$before." seconds is_int<br>";

$before = microtime(true);
for ($i=0; $i<100000; $i++) {
    $test = ($number&1?true:false);
}
$after = microtime(true);

echo $after-$before." seconds & operator<br>";

The results I got were pretty consistent. Here's a sample:

0.041879177093506 seconds mod
0.15969395637512 seconds is_int
0.044223070144653 seconds & operator

Seeing the underlying SQL in the Spring JdbcTemplate?

This worked for me with log4j2 and xml parameters:

<?xml version="1.0" encoding="UTF-8"?>
<Configuration status="debug">
    <Properties>
        <Property name="log-path">/some_path/logs/</Property>
        <Property name="app-id">my_app</Property>
    </Properties>

    <Appenders>
        <RollingFile name="file-log" fileName="${log-path}/${app-id}.log"
            filePattern="${log-path}/${app-id}-%d{yyyy-MM-dd}.log">
            <PatternLayout>
                <pattern>[%-5level] %d{yyyy-MM-dd HH:mm:ss.SSS} [%t] %c{1} - %msg%n
                </pattern>
            </PatternLayout>
            <Policies>
                <TimeBasedTriggeringPolicy interval="1"
                    modulate="true" />
            </Policies>
        </RollingFile>

        <Console name="console" target="SYSTEM_OUT">
            <PatternLayout
                pattern="[%-5level] %d{yyyy-MM-dd HH:mm:ss.SSS} [%t] %c{1} - %msg%n" />
        </Console>
    </Appenders>
    <Loggers>

        <Logger name="org.springframework.jdbc.core" level="trace" additivity="false">
            <appender-ref ref="file-log" />
            <appender-ref ref="console" />
        </Logger>

        <Root level="info" additivity="false">
            <appender-ref ref="file-log" />
            <appender-ref ref="console" />
        </Root>
    </Loggers>

</Configuration>

Result console and file log was:

JdbcTemplate - Executing prepared SQL query
JdbcTemplate - Executing prepared SQL statement [select a, b from c where id = ? ]
StatementCreatorUtils - Setting SQL statement parameter value: column index 1, parameter value [my_id], value class [java.lang.String], SQL type unknown

Just copy/past

HTH

"Cannot start compilation: the output path is not specified for module..."

If none of the above method worked then try this it worked for me.

Go to File > Project Structure> Project and then in Project Compiler Output click on the three dots and provide the path of your project name(name of the file) and then click on Apply and than on Ok.

JavaScript hide/show element

Vanilla JS for Classes and IDs

By ID

document.querySelector('#element-id').style.display = 'none';

By Class (Single element)

document.querySelector('.element-class-name').style.display = 'none';

By Class (Multiple elements)

for (const elem of document.querySelectorAll('.element-class-name')) {
    elem.style.display = 'none';
}

Read line with Scanner

This code reads the file line by line.

public static void readFileByLine(String fileName) {
  try {
   File file = new File(fileName);
   Scanner scanner = new Scanner(file);
   while (scanner.hasNext()) {
    System.out.println(scanner.next());
   }
   scanner.close();
  } catch (FileNotFoundException e) {
   e.printStackTrace();
  } 
 }

You can also set a delimiter as a line separator and then perform the same.

 scanner.useDelimiter(System.getProperty("line.separator"));

You have to check whether there is a next token available and then read the next token. You will also need to doublecheck the input given to the Scanner. i.e. dico.txt. By default, Scanner breaks its input based on whitespace. Please ensure that the input has the delimiters in right place

UPDATED ANSWER for your comment:

I just tried to create an input file with the content as below

a
à
abaissa
abaissable
abaissables
abaissai
abaissaient
abaissais
abaissait

tried to read it with the below code.it just worked fine.

 File file = new File("/home/keerthivasan/Desktop/input.txt");
     Scanner scr = null;
         try {
            scr = new Scanner(file);
            while(scr.hasNext()){
                System.out.println("line : "+scr.next());
            }
        } catch (FileNotFoundException ex) {
            Logger.getLogger(ScannerTest.class.getName()).log(Level.SEVERE, null, ex);
        }

Output:

line : a
line : à
line : abaissa
line : abaissable
line : abaissables
line : abaissai
line : abaissaient
line : abaissais
line : abaissait

so, I am sure that this should work. Since you work in Windows ennvironment, The End of Line (EOL) sequence (0x0D 0x0A, \r\n) is actually two ASCII characters, a combination of the CR and LF characters. if you set your Scanner instance to use delimiter as follows, it will pick up probably

 scr = new Scanner(file);
 scr.useDelimiter("\r\n");

and then do your looping to read lines. Hope this helps!

Change the class from factor to numeric of many columns in a data frame

I think that ucfagls found why your loop is not working.

In case you still don't want use a loop here is solution with lapply:

factorToNumeric <- function(f) as.numeric(levels(f))[as.integer(f)] 
cols <- c(1, 3:ncol(stats))
stats[cols] <- lapply(stats[cols], factorToNumeric)

Edit. I found simpler solution. It seems that as.matrix convert to character. So

stats[cols] <- as.numeric(as.matrix(stats[cols]))

should do what you want.

Youtube iframe wmode issue

Try adding ?wmode=transparent to the end of the URL. Worked for me.

System.Drawing.Image to stream C#

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

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

     return stream;
 }

How to lock orientation of one view controller to portrait mode only in Swift

Things can get quite messy when you have a complicated view hierarchy, like having multiple navigation controllers and/or tab view controllers.

This implementation puts it on the individual view controllers to set when they would like to lock orientations, instead of relying on the App Delegate to find them by iterating through subviews.

Swift 3, 4, 5

In AppDelegate:

/// set orientations you want to be allowed in this property by default
var orientationLock = UIInterfaceOrientationMask.all

func application(_ application: UIApplication, supportedInterfaceOrientationsFor window: UIWindow?) -> UIInterfaceOrientationMask {
        return self.orientationLock
}

In some other global struct or helper class, here I created AppUtility:

struct AppUtility {

    static func lockOrientation(_ orientation: UIInterfaceOrientationMask) {
    
        if let delegate = UIApplication.shared.delegate as? AppDelegate {
            delegate.orientationLock = orientation
        }
    }

    /// OPTIONAL Added method to adjust lock and rotate to the desired orientation
    static func lockOrientation(_ orientation: UIInterfaceOrientationMask, andRotateTo rotateOrientation:UIInterfaceOrientation) {
   
        self.lockOrientation(orientation)
    
        UIDevice.current.setValue(rotateOrientation.rawValue, forKey: "orientation")
        UINavigationController.attemptRotationToDeviceOrientation()
    }

}

Then in the desired ViewController you want to lock orientations:

 override func viewWillAppear(_ animated: Bool) {
    super.viewWillAppear(animated)
    
    AppUtility.lockOrientation(.portrait)
    // Or to rotate and lock
    // AppUtility.lockOrientation(.portrait, andRotateTo: .portrait)
    
}

override func viewWillDisappear(_ animated: Bool) {
    super.viewWillDisappear(animated)
    
    // Don't forget to reset when view is being removed
    AppUtility.lockOrientation(.all)
}

If iPad or Universal App

Make sure that "Requires full screen" is checked in Target Settings -> General -> Deployment Info. supportedInterfaceOrientationsFor delegate will not get called if that is not checked. enter image description here

Bootstrap 3 truncate long text inside rows of a table in a responsive way

This is what I achieved, but had to set width, and it cannot be percentual.

_x000D_
_x000D_
.trunc{_x000D_
  width:250px; _x000D_
  white-space: nowrap; _x000D_
  overflow: hidden; _x000D_
  text-overflow: ellipsis;_x000D_
}_x000D_
table tr td {_x000D_
padding: 5px_x000D_
}_x000D_
table tr td {_x000D_
background: salmon_x000D_
}_x000D_
table tr td:first-child {_x000D_
background: lightsalmon_x000D_
}
_x000D_
<link href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.6/css/bootstrap.min.css" rel="stylesheet"/>_x000D_
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.6/js/bootstrap.min.js"></script>_x000D_
<table>_x000D_
      _x000D_
      <tr>_x000D_
        <td>Quisque dignissim ante in tincidunt gravida. Maecenas lectus turpis</td>_x000D_
      <td>_x000D_
         <div class="trunc">Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industry's standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book. It has survived not only five centuries, but also the leap into electronic typesetting, remaining essentially unchanged. It was popularised in the 1960s with the release of Letraset sheets containing Lorem Ipsum passages, and more recently with desktop publishing software like Aldus PageMaker including versions of Lorem Ipsum._x000D_
         </div>_x000D_
    </td>_x000D_
        </tr>_x000D_
      </table>
_x000D_
_x000D_
_x000D_

or this: http://collaboradev.com/2015/03/28/responsive-css-truncate-and-ellipsis/

VERR_VMX_MSR_VMXON_DISABLED when starting an image from Oracle virtual box

I had the same problem. I enabled vtx in bios and it didn't worked. After a doublecheck in the bios I recogniced that the bios said that you have to poweroff (and realy power off) the computer. After that it worked. Heavy Pitfall :)

Always pass weak reference of self into block in ARC?

This is how you can use the self inside the block:

//calling of the block

 NSString *returnedText= checkIfOutsideMethodIsCalled(self);

NSString* (^checkIfOutsideMethodIsCalled)(*)=^NSString*(id obj)
{
             [obj MethodNameYouWantToCall]; // this is how it will call the object 
            return @"Called";


};

How do I decode a base64 encoded string?

Simple:

byte[] data = Convert.FromBase64String(encodedString);
string decodedString = Encoding.UTF8.GetString(data);

Error pushing to GitHub - insufficient permission for adding an object to repository database

I was getting this error because every time a user push some content, the group of the file changed to the user. And then if some other user tried to push into the repository, it caused permission error and the push was rejected. So one need to ask your sysadmin to change the settings of the repository so that group of any file in the repository is not changed for any push by any user.

To avoid such problem, please ensure that when you initialize your git repository, use the command "git init --shared=group".

Remove whitespaces inside a string in javascript

Probably because you forgot to implement the solution in the accepted answer. That's the code that makes trim() work.

update

This answer only applies to older browsers. Newer browsers apparently support trim() natively.

What is code coverage and how do YOU measure it?

Code coverage has been explained well in the previous answers. So this is more of an answer to the second part of the question.

We've used three tools to determine code coverage.

  1. JTest - a proprietary tool built over JUnit. (It generates unit tests as well.)
  2. Cobertura - an open source code coverage tool that can easily be coupled with JUnit tests to generate reports.
  3. Emma - another - this one we've used for a slightly different purpose than unit testing. It has been used to generate coverage reports when the web application is accessed by end-users. This coupled with web testing tools (example: Canoo) can give you very useful coverage reports which tell you how much code is covered during typical end user usage.

We use these tools to

  • Review that developers have written good unit tests
  • Ensure that all code is traversed during black-box testing

jQuery Set Select Index

you can set selectoption variable value dynamically as well as option will be selected.You can try following code

code:

 <script src="http://ajax.googleapis.com/ajax/libs/jquery/1.5.2/jquery.min.js"></script>

      $(function(){
            $('#allcheck').click(function(){
             // $('#select_option').val([1,2,5]);also can use multi selectbox
              // $('#select_option').val(1);
               var selectoption=3;
           $("#selectBox>option[value="+selectoption+"]").attr('selected', 'selected');
    });

});

HTML CODE:

   <select id="selectBox">
       <option value="0">Number 0</option>
       <option value="1">Number 1</option>
       <option value="2">Number 2</option>
       <option value="3">Number 3</option>
       <option value="4">Number 4</option>
       <option value="5">Number 5</option>
       <option value="6">Number 6</option>
       <option value="7">Number 7</option>
 </select> <br>
<strong>Select&nbsp;&nbsp; <a style="cursor:pointer;" id="allcheck">click for select option</a></strong>

internal/modules/cjs/loader.js:582 throw err

Caseyjustus comment helped me. Apparently I had space in my require path.

const listingController = require("../controllers/ listingController");

I changed my code to

const listingController = require("../controllers/listingController");

and everything was fine.

Warning as error - How to get rid of these

Each project in Visual Studio has a "treat warnings as errors" option. Go through each of your projects and change that setting:

  1. Right-click on your project, select "Properties".
  2. Click "Build".
  3. Switch "Treat warnings as errors" from "All" to "Specific warnings" or "None".

The location of this switch varies, depending on the type of project (class library vs. web application, for example).

How to install APK from PC?

  1. Connect Android device to PC via USB cable and turn on USB storage.
  2. Copy .apk file to attached device's storage.
  3. Turn off USB storage and disconnect it from PC.
  4. Check the option Settings ? Applications ? Unknown sources OR Settings > Security > Unknown Sources.
  5. Open FileManager app and click on the copied .apk file. If you can't fine the apk file try searching or allowing hidden files. It will ask you whether to install this app or not. Click Yes or OK.

This procedure works even if ADB is not available.

Using SVG as background image

Try placing it on your body

body {
    height: 100%;
    background-image: url(../img/bg.svg);
    background-size:100% 100%;
    -o-background-size: 100% 100%;
    -webkit-background-size: 100% 100%;
    background-size:cover;
}

Setting Camera Parameters in OpenCV/Python

I wasn't able to fix the problem OpenCV either, but a video4linux (V4L2) workaround does work with OpenCV when using Linux. At least, it does on my Raspberry Pi with Rasbian and my cheap webcam. This is not as solid, light and portable as you'd like it to be, but for some situations it might be very useful nevertheless.

Make sure you have the v4l2-ctl application installed, e.g. from the Debian v4l-utils package. Than run (before running the python application, or from within) the command:

v4l2-ctl -d /dev/video1 -c exposure_auto=1 -c exposure_auto_priority=0 -c exposure_absolute=10

It overwrites your camera shutter time to manual settings and changes the shutter time (in ms?) with the last parameter to (in this example) 10. The lower this value, the darker the image.

Want custom title / image / description in facebook share link from a flash app

I think this site has the solution, i will test it now. It Seems like facebook has changed the parameters of share.php so, in order to customize share window text and images you have to put parameters in a "p" array.

http://www.daddydesign.com/wordpress/how-to-create-a-custom-facebook-share-button-for-your-iframe-tab/

Check it out.

Closing Twitter Bootstrap Modal From Angular Controller

Have you looked at angular-ui bootstrap? There's a Dialog (ui.bootstrap.dialog) directive that works quite well. You can close the dialog during the call back the angular way (per the example):

$scope.close = function(result){
  dialog.close(result);
};

Update:

The directive has since been renamed Modal.

Is std::vector copying the objects with a push_back?

Relevant in C++11 is the emplace family of member functions, which allow you to transfer ownership of objects by moving them into containers.

The idiom of usage would look like

std::vector<Object> objs;

Object l_value_obj { /* initialize */ };
// use object here...

objs.emplace_back(std::move(l_value_obj));

The move for the lvalue object is important as otherwise it would be forwarded as a reference or const reference and the move constructor would not be called.

Android Room - simple select query - Cannot access database on the main thread

With the Jetbrains Anko library, you can use the doAsync{..} method to automatically execute database calls. This takes care of the verbosity problem you seemed to have been having with mcastro's answer.

Example usage:

    doAsync { 
        Application.database.myDAO().insertUser(user) 
    }

I use this frequently for inserts and updates, however for select queries I reccommend using the RX workflow.

GZIPInputStream reading line by line

BufferedReader in = new BufferedReader(new InputStreamReader(
        new GZIPInputStream(new FileInputStream("F:/gawiki-20090614-stub-meta-history.xml.gz"))));

String content;

while ((content = in.readLine()) != null)

   System.out.println(content);

Remove all HTMLtags in a string (with the jquery text() function)

I found in my specific case that I just needed to trim the content. Maybe not the answer asked in the question. But I thought I should add this answer anyway.

$(myContent).text().trim()

How do I reverse a commit in git?

You can do git push --force but be aware that you are rewriting history and anyone using the repo will have issue with this.

If you want to prevent this problem, don't use reset, but instead use git revert

Google Map API - Removing Markers

You can try this

    markers[markers.length-1].setMap(null);

Hope it works.

After installation of Gulp: “no command 'gulp' found”

Tried with sudo and it worked !!

sudo npm install --global gulp-cli

Is there a simple JavaScript slider?

The lightweight MooTools framework has one: http://demos.mootools.net/Slider

xlsxwriter: is there a way to open an existing worksheet in my workbook?

After searching a bit about the method to open the existing sheet in xlxs, i discovered

existingWorksheet = wb.get_worksheet_by_name('Your Worksheet name goes here...')
existingWorksheet.write_row(0,0,'xyz')

You can now append/write any data to the open worksheet. I hope it helps. Thanks

Deep copy in ES6 using the spread syntax

Here is the deepClone function which handles all primitive, array, object, function data types

_x000D_
_x000D_
function deepClone(obj){_x000D_
 if(Array.isArray(obj)){_x000D_
  var arr = [];_x000D_
  for (var i = 0; i < obj.length; i++) {_x000D_
   arr[i] = deepClone(obj[i]);_x000D_
  }_x000D_
  return arr;_x000D_
 }_x000D_
_x000D_
 if(typeof(obj) == "object"){_x000D_
  var cloned = {};_x000D_
  for(let key in obj){_x000D_
   cloned[key] = deepClone(obj[key])_x000D_
  }_x000D_
  return cloned; _x000D_
 }_x000D_
 return obj;_x000D_
}_x000D_
_x000D_
console.log( deepClone(1) )_x000D_
_x000D_
console.log( deepClone('abc') )_x000D_
_x000D_
console.log( deepClone([1,2]) )_x000D_
_x000D_
console.log( deepClone({a: 'abc', b: 'def'}) )_x000D_
_x000D_
console.log( deepClone({_x000D_
  a: 'a',_x000D_
  num: 123,_x000D_
  func: function(){'hello'},_x000D_
  arr: [[1,2,3,[4,5]], 'def'],_x000D_
  obj: {_x000D_
    one: {_x000D_
      two: {_x000D_
        three: 3_x000D_
      }_x000D_
    }_x000D_
  }_x000D_
}) ) 
_x000D_
_x000D_
_x000D_

Run Python script at startup in Ubuntu

In similar situations, I've done well by putting something like the following into /etc/rc.local:

cd /path/to/my/script
./my_script.py &
cd -
echo `date +%Y-%b-%d_%H:%M:%S` > /tmp/ran_rc_local  # check that rc.local ran

This has worked on multiple versions of Fedora and on Ubuntu 14.04 LTS, for both python and perl scripts.

Where is the documentation for the values() method of Enum?

Run this

    for (Method m : sex.class.getDeclaredMethods()) {
        System.out.println(m);
    }

you will see

public static test.Sex test.Sex.valueOf(java.lang.String)
public static test.Sex[] test.Sex.values()

These are all public methods that "sex" class has. They are not in the source code, javac.exe added them

Notes:

  1. never use sex as a class name, it's difficult to read your code, we use Sex in Java

  2. when facing a Java puzzle like this one, I recommend to use a bytecode decompiler tool (I use Andrey Loskutov's bytecode outline Eclispe plugin). This will show all what's inside a class

Call Class Method From Another Class

You can call a function from within a class with:

A().method1()

Is there a way to get the git root directory in one command?

$ git config alias.root '!pwd'
# then you have:
$ git root

JavaScript - Hide a Div at startup (load)

This method I've used a lot, not sure if it is a very good way but it works fine for my needs.

<html>
<head>  
    <script language="JavaScript">
    function setVisibility(id, visibility) {
    document.getElementById(id).style.display = visibility;
    }
    </script>
</head>
<body>
    <div id="HiddenStuff1" style="display:none">
    CONTENT TO HIDE 1
    </div>
    <div id="HiddenStuff2" style="display:none">
    CONTENT TO HIDE 2
    </div>
    <div id="HiddenStuff3" style="display:none">
    CONTENT TO HIDE 3
    </div>
    <input id="YOUR ID" title="HIDDEN STUFF 1" type=button name=type value='HIDDEN STUFF 1' onclick="setVisibility('HiddenStuff1', 'inline');setVisibility('HiddenStuff2', 'none');setVisibility('HiddenStuff3', 'none');";>
    <input id="YOUR ID" title="HIDDEN STUFF 2" type=button name=type value='HIDDEN STUFF 2' onclick="setVisibility('HiddenStuff1', 'none');setVisibility('HiddenStuff2', 'inline');setVisibility('HiddenStuff3', 'none');";>
    <input id="YOUR ID" title="HIDDEN STUFF 3" type=button name=type value='HIDDEN STUFF 3' onclick="setVisibility('HiddenStuff1', 'none');setVisibility('HiddenStuff2', 'none');setVisibility('HiddenStuff3', 'inline');";>
</body>
</html>

How to use Servlets and Ajax?

The right way to update the page currently displayed in the user's browser (without reloading it) is to have some code executing in the browser update the page's DOM.

That code is typically javascript that is embedded in or linked from the HTML page, hence the AJAX suggestion. (In fact, if we assume that the updated text comes from the server via an HTTP request, this is classic AJAX.)

It is also possible to implement this kind of thing using some browser plugin or add-on, though it may be tricky for a plugin to reach into the browser's data structures to update the DOM. (Native code plugins normally write to some graphics frame that is embedded in the page.)

Does uninstalling a package with "pip" also remove the dependent packages?

No, it doesn't uninstall the dependencies packages. It only removes the specified package:

$ pip install specloud
$ pip freeze # all the packages here are dependencies of specloud package

figleaf==0.6.1
nose==1.1.2
pinocchio==0.3
specloud==0.4.5

$ pip uninstall specloud
$ pip freeze

figleaf==0.6.1
nose==1.1.2
pinocchio==0.3

As you can see those packages are dependencies from specloud and they're still there, but not the specloud package itself.

As mentioned below, You can install and use the pip-autoremove utility to remove a package plus unused dependencies.

jackson deserialization json to java-objects

It looks like you are trying to read an object from JSON that actually describes an array. Java objects are mapped to JSON objects with curly braces {} but your JSON actually starts with square brackets [] designating an array.

What you actually have is a List<product> To describe generic types, due to Java's type erasure, you must use a TypeReference. Your deserialization could read: myProduct = objectMapper.readValue(productJson, new TypeReference<List<product>>() {});

A couple of other notes: your classes should always be PascalCased. Your main method can just be public static void main(String[] args) throws Exception which saves you all the useless catch blocks.

What are Covering Indexes and Covered Queries in SQL Server?

A Covering Index is a Non-Clustered index. Both Clustered and Non-Clustered indexes use B-Tree data structure to improve the search for data, the difference is that in the leaves of a Clustered Index a whole record (i.e. row) is stored physically right there!, but this is not the case for Non-Clustered indexes. The following examples illustrate it:

Example: I have a table with three columns: ID, Fname and Lname.

enter image description here

However, for a Non-Clustered index, there are two possibilities: either the table already has a Clustered index or it doesn't:

enter image description here

As the two diagrams show, such Non-Clustered indexes do not provide a good performance, because they cannot find the favorite value (i.e. Lname) solely from the B-Tree. Instead they have to do an extra Look Up step (either Key or RID look up) to find the value of Lname. And, this is where covered index comes to the screen. Here, the Non-Clustered index on ID coveres the value of Lname right next to it in the leaves of the B-Tree and there is no need for any type of look up anymore.

enter image description here

Web API optional parameters

you need only set default value to parameters(you do not need the Route attribute):

public IHttpActionResult Get(string apc = null, string xpc = null, int? sku = null)
{ ... }

how can I enable PHP Extension intl?

For instalation of magento on local host you need to uncomment the extension=php_intl.dll in php.ini and copy all icudt57.dll,icuin57.dll,icuio57.dll,icule57.dll,iculx57.dll,icuuc57.dll files from php folder to XAMPP\apache\bin folder.

Then Restart the xamp server

Pass Array Parameter in SqlCommand

I want to propose another way, how to solve limitation with IN operator.

For example we have following query

select *
from Users U
WHERE U.ID in (@ids)

We want to pass several IDs to filter users. Unfortunately it is not possible to do with C# in easy way. But I have fount workaround for this by using "string_split" function. We need to rewrite a bit our query to following.

declare @ids nvarchar(max) = '1,2,3'

SELECT *
FROM Users as U
CROSS APPLY string_split(@ids, ',') as UIDS
WHERE U.ID = UIDS.value

Now we can easily pass one parameter enumeration of values separated by comma.

Configure DataSource programmatically in Spring Boot

for springboot 2.1.7 working with url seems not to work. change with jdbcUrl instead.

In properties:

security:
      datasource:
        jdbcUrl: jdbc:mysql://ip:3306/security
        username: user
        password: pass

In java:

@ConfigurationProperties(prefix = "security.datasource")
@Bean("dataSource")
@Primary
public DataSource dataSource(){

    return DataSourceBuilder
            .create()
            .build();
}

How to set cursor position in EditText?

EditText editText = findViewById(R.id.editText);
editText.setSelection(editText.getText().length());

Tainted canvases may not be exported

Check out CORS enabled image from MDN. Basically you must have a server hosting images with the appropriate Access-Control-Allow-Origin header.

_x000D_
_x000D_
<IfModule mod_setenvif.c>
    <IfModule mod_headers.c>
        <FilesMatch "\.(cur|gif|ico|jpe?g|png|svgz?|webp)$">
            SetEnvIf Origin ":" IS_CORS
            Header set Access-Control-Allow-Origin "*" env=IS_CORS
        </FilesMatch>
    </IfModule>
</IfModule>
_x000D_
_x000D_
_x000D_

You will be able to save those images to DOM Storage as if they were served from your domain otherwise you will run into security issue.

_x000D_
_x000D_
var img = new Image,
    canvas = document.createElement("canvas"),
    ctx = canvas.getContext("2d"),
    src = "http://example.com/image"; // insert image url here

img.crossOrigin = "Anonymous";

img.onload = function() {
    canvas.width = img.width;
    canvas.height = img.height;
    ctx.drawImage( img, 0, 0 );
    localStorage.setItem( "savedImageData", canvas.toDataURL("image/png") );
}
img.src = src;
// make sure the load event fires for cached images too
if ( img.complete || img.complete === undefined ) {
    img.src = "data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///ywAAAAAAQABAAACAUwAOw==";
    img.src = src;
}
_x000D_
_x000D_
_x000D_

how to parse json using groovy

Have you tried using JsonSlurper?

Example usage:

def slurper = new JsonSlurper()
def result = slurper.parseText('{"person":{"name":"Guillaume","age":33,"pets":["dog","cat"]}}')

assert result.person.name == "Guillaume"
assert result.person.age == 33
assert result.person.pets.size() == 2
assert result.person.pets[0] == "dog"
assert result.person.pets[1] == "cat"

Remove category & tag base from WordPress url - without a plugin

Adding "." or "/" won't work if you want a consolidated blog view. Also, I have know idea what that solutions would do for the RSS or XML feeds. I feel better sticking with the WP convention. However, I did come up with a more elegant approach.

First, I name the base category url "blog"

Then I created a category called "all". Finally, I but all my subcategories under "all". So I get a url structure like this.

/blog - 404 - recommend 301 redirect to /blog/all/    
/blog/all/ -  all posts combined.
/blog/all/category1/ - posts filtered by category1
/blog/all/category2/ - posts filterer by category2

I put a custom label on the menu item called "Blog", but it goes to blog/all. It would be a good idea to 301 redirect /blog to /blog/all in the .htaccess file to avoid the 404 on /blog.

The type initializer for 'System.Data.Entity.Internal.AppConfig' threw an exception

in my case

<section name="entityFramework"

must be updated from version 4 to 6. I mean a project was updated EntityFramework from 4 to 6 but web.config was not updated.

Send PHP variable to javascript function

Your JavaScript would have to be defined within a PHP-parsed file.

For example, in index.php you could place

<?php
$time = time();
?>
<script>
    document.write(<?php echo $time; ?>);
</script>

Why use double indirection? or Why use pointers to pointers?

I saw a very good example today, from this blog post, as I summarize below.

Imagine you have a structure for nodes in a linked list, which probably is

typedef struct node
{
    struct node * next;
    ....
} node;

Now you want to implement a remove_if function, which accepts a removal criterion rm as one of the arguments and traverses the linked list: if an entry satisfies the criterion (something like rm(entry)==true), its node will be removed from the list. In the end, remove_if returns the head (which may be different from the original head) of the linked list.

You may write

for (node * prev = NULL, * curr = head; curr != NULL; )
{
    node * const next = curr->next;
    if (rm(curr))
    {
        if (prev)  // the node to be removed is not the head
            prev->next = next;
        else       // remove the head
            head = next;
        free(curr);
    }
    else
        prev = curr;
    curr = next;
}

as your for loop. The message is, without double pointers, you have to maintain a prev variable to re-organize the pointers, and handle the two different cases.

But with double pointers, you can actually write

// now head is a double pointer
for (node** curr = head; *curr; )
{
    node * entry = *curr;
    if (rm(entry))
    {
        *curr = entry->next;
        free(entry);
    }
    else
        curr = &entry->next;
}

You don't need a prev now because you can directly modify what prev->next pointed to.

To make things clearer, let's follow the code a little bit. During the removal:

  1. if entry == *head: it will be *head (==*curr) = *head->next -- head now points to the pointer of the new heading node. You do this by directly changing head's content to a new pointer.
  2. if entry != *head: similarly, *curr is what prev->next pointed to, and now points to entry->next.

No matter in which case, you can re-organize the pointers in a unified way with double pointers.

Download history stock prices automatically from yahoo finance in python

When you're going to work with such time series in Python, pandas is indispensable. And here's the good news: it comes with a historical data downloader for Yahoo: pandas.io.data.DataReader.

from pandas.io.data import DataReader
from datetime import datetime

ibm = DataReader('IBM',  'yahoo', datetime(2000, 1, 1), datetime(2012, 1, 1))
print(ibm['Adj Close'])

Here's an example from the pandas documentation.

Update for pandas >= 0.19:

The pandas.io.data module has been removed from pandas>=0.19 onwards. Instead, you should use the separate pandas-datareader package. Install with:

pip install pandas-datareader

And then you can do this in Python:

import pandas_datareader as pdr
from datetime import datetime

ibm = pdr.get_data_yahoo(symbols='IBM', start=datetime(2000, 1, 1), end=datetime(2012, 1, 1))
print(ibm['Adj Close'])

Downloading from Google Finance is also supported.

There's more in the documentation of pandas-datareader.

How do I add an existing directory tree to a project in Visual Studio?

You can also drag and drop the folder from Windows Explorer onto your Visual Studio solution window.

How to subtract n days from current date in java?

for future use find day of the week ,deduct day and display the deducted day using date.

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

String[] days = { "Sunday", "Monday", "Tuesday", "Wednesday",
        "Thursday", "Friday", "Saturday" };
SimpleDateFormat format1 = new SimpleDateFormat("dd/MM/yyyy");
Date dt1 = format1.parse("20/10/2013");

Calendar c = Calendar.getInstance();
c.setTime(dt1);
int dayOfWeek = c.get(Calendar.DAY_OF_WEEK);
long diff = Calendar.getInstance().getTime().getTime() ;
System.out.println(dayOfWeek);

switch (dayOfWeek) {

case 6:
    System.out.println(days[dayOfWeek - 1]);
    break;
case 5:

    System.out.println(days[dayOfWeek - 1]);
    break;      
case 4:
    System.out.println(days[dayOfWeek - 1]);
    break;
case 3:

    System.out.println(days[dayOfWeek - 1]);
    break;
case 2:
    System.out.println(days[dayOfWeek - 1]);
    break;
case 1:

    System.out.println(days[dayOfWeek - 1]);

     diff = diff -(dt1.getTime()- 3 );
     long valuebefore = dt1.getTime();
     long valueafetr = dt1.getTime()-2;
     System.out.println("DATE IS befor subtraction :"+valuebefore);
     System.out.println("DATE IS after subtraction :"+valueafetr);

     long x= dt1.getTime()-(2 * 24 * 3600 * 1000);
     System.out.println("Deducted date to find firday is - 2 days form Sunday :"+new Date((dt1.getTime()-(2*24*3600*1000))));
     System.out.println("DIffrence from now on is :"+diff);
        if(diff > 0) {

            diff = diff / (1000 * 60 * 60 * 24);
            System.out.println("Diff"+diff);
            System.out.println("Date is Expired!"+(dt1.getTime() -(long)2));
        }

    break;
}
}

T-SQL split string based on delimiter

Try filtering out the rows that contain strings with the delimiter and work on those only like:

SELECT SUBSTRING(myColumn, 1, CHARINDEX('/', myColumn)-1) AS FirstName,
       SUBSTRING(myColumn, CHARINDEX('/', myColumn) + 1, 1000) AS LastName
FROM   MyTable
WHERE CHARINDEX('/', myColumn) > 0

Or

SELECT SUBSTRING(myColumn, 1, CHARINDEX('/', myColumn)-1) AS FirstName,
       SUBSTRING(myColumn, CHARINDEX('/', myColumn) + 1, 1000) AS LastName
FROM   MyTable
WHERE myColumn LIKE '%/%'

embedding image in html email

One additional hint to Pavel Perna's post which helped me very much (cannot comment with my reputation, that's why I post this as answer): In some versions of Microsoft Exchange, the inline contents disposition is removed (see this post by Microsoft). The image is simply not part in the mail the user sees in Outlook. As a workaround, use "Content-Disposition: attachement" instead. Outlook 2016 won't show images as attachement that are used in the mail message, although they use the "Content-Disposition: attachement".

ASP.NET MVC get textbox input value

you can do it so simple:

First: For Example in Models you have User.cs with this implementation

public class User
 {
   public string username { get; set; }
   public string age { get; set; }
 } 

We are passing the empty model to user – This model would be filled with user’s data when he submits the form like this

public ActionResult Add()
{
  var model = new User();
  return View(model);
}

When you return the View by empty User as model, it maps with the structure of the form that you implemented. We have this on HTML side:

@model MyApp.Models.Student
@using (Html.BeginForm()) 
 {
    @Html.AntiForgeryToken()

    <div class="form-horizontal">
        <h4>Student</h4>
        <hr />
        @Html.ValidationSummary(true, "", new { @class = "text-danger" })
        <div class="form-group">
            @Html.LabelFor(model => model.username, htmlAttributes: new { 
                           @class = "control-label col-md-2" })
            <div class="col-md-10">
                 @Html.EditorFor(model => model.username, new { 
                                 htmlAttributes = new { @class = "form-
                                 control" } })
                 @Html.ValidationMessageFor(model => model.userame, "", 
                                            new { @class = "text-danger" })
            </div>
        </div>

        <div class="form-group">
            @Html.LabelFor(model => model.age, htmlAttributes: new { @class 
                           = "control-label col-md-2" })
            <div class="col-md-10">
                @Html.EditorFor(model => model.age, new { htmlAttributes = 
                                new { @class = "form-control" } })
                @Html.ValidationMessageFor(model => model.age, "", new { 
                                           @class = "text-danger" })
            </div>
        </div>
        <div class="form-group">
            <div class="col-md-offset-2 col-md-10">
                <input type="submit" value="Create" class="btn btn-default" 
                 />
            </div>
        </div>
   </div>
}

So on button submit you will use it like this

[HttpPost]
public ActionResult Add(User user)
 {
   // now user.username has the value that user entered on form
 }

Java: Check if enum contains a given string?

This should do it:

public static boolean contains(String test) {

    for (Choice c : Choice.values()) {
        if (c.name().equals(test)) {
            return true;
        }
    }

    return false;
}

This way means you do not have to worry about adding additional enum values later, they are all checked.

Edit: If the enum is very large you could stick the values in a HashSet:

public static HashSet<String> getEnums() {

  HashSet<String> values = new HashSet<String>();

  for (Choice c : Choice.values()) {
      values.add(c.name());
  }

  return values;
}

Then you can just do: values.contains("your string") which returns true or false.

what is the unsigned datatype?

in C, unsigned is a shortcut for unsigned int.

You have the same for long that is a shortcut for long int

And it is also possible to declare a unsigned long (it will be a unsigned long int).

This is in the ANSI standard

Select all elements with a "data-xxx" attribute without using jQuery

Here is an interesting solution: it uses the browsers CSS engine to to add a dummy property to elements matching the selector and then evaluates the computed style to find matched elements:

It does dynamically create a style rule [...] It then scans the whole document (using the much decried and IE-specific but very fast document.all) and gets the computed style for each of the elements. We then look for the foo property on the resulting object and check whether it evaluates as “bar”. For each element that matches, we add to an array.

PostgreSQL psql terminal command

psql --pset=format=FORMAT

Great for executing queries from command line, e.g.

psql --pset=format=unaligned -c "select bandanavalue from bandana where bandanakey = 'atlassian.confluence.settings';"

Run batch file as a Windows service

NSSM is totally free and hyper-easy, running command prompt / terminal as administrator:

nssm install "YourCoolServiceNameLabel"

then a dialog will appear so you can choose where is the file you want to run.

to uninstall

nssm remove "YourCoolServiceNameLabel"

Immutable array in Java

No, this is not possible. However, one could do something like this:

List<Integer> temp = new ArrayList<Integer>();
temp.add(Integer.valueOf(0));
temp.add(Integer.valueOf(2));
temp.add(Integer.valueOf(3));
temp.add(Integer.valueOf(4));
List<Integer> immutable = Collections.unmodifiableList(temp);

This requires using wrappers, and is a List, not an array, but is the closest you will get.

Write variable to file, including name

You can use pickle

import pickle
dict = {'one': 1, 'two': 2}
file = open('dump.txt', 'wb')
pickle.dump(dict, file)
file.close()

and to read it again

file = open('dump.txt', 'rb')
dict = pickle.load(file)

EDIT: Guess I misread your question, sorry ... but pickle might help all the same. :)

XMLHttpRequest cannot load file. Cross origin requests are only supported for HTTP

If you use the WebStorm Javascript IDE, you can just open your project from WebStorm in your browser. WebStorm will automatically start a server and you won't get any of these errors anymore, because you are now accessing the files with the allowed/supported protocols (HTTP).

How do I print out the value of this boolean? (Java)

There are several problems.

One is of style; always capitalize class names. This is a universally observed Java convention. Failing to do so confuses other programmers.

Secondly, the line

System.out.println(boolean isLeapYear);

is a syntax error. Delete it.

Thirdly.

You never call the function from your main routine. That is why you never see any reply to the input.

Cannot read property 'getContext' of null, using canvas

This might seem like overkill, but if in another case you were trying to load a canvas from js (like I am doing), you could use a setInterval function and an if statement to constantly check if the canvas has loaded.

//set up the interval
var thisInterval = setInterval(function{
  //this if statment checks if the id "thisCanvas" is linked to something
  if(document.getElementById("thisCanvas") != null){
    //do what you want


    //clearInterval() will remove the interval if you have given your interval a name.
    clearInterval(thisInterval)
  }
//the 500 means that you will loop through this every 500 milliseconds (1/2 a second)
},500)

(In this example the canvas I am trying to load has an id of "thisCanvas")

Pandas Replace NaN with blank/empty string

I tried with one column of string values with nan.

To remove the nan and fill the empty string:

df.columnname.replace(np.nan,'',regex = True)

To remove the nan and fill some values:

df.columnname.replace(np.nan,'value',regex = True)

I tried df.iloc also. but it needs the index of the column. so you need to look into the table again. simply the above method reduced one step.

Best Way to Refresh Adapter/ListView on Android

just write in your Custom ArrayAdaper this code:

public void swapItems(ArrayList<Item> arrayList) {
    this.clear();
    this.addAll(arrayList);
}

How to debug a bash script?

This answer is valid and useful: https://stackoverflow.com/a/951352

But, I find that the "standard" script debugging methods are inefficient, unintuitive, and hard to use. For those used to sophisticated GUI debuggers that put everything at your fingertips and make the job a breeze for easy problems (and possible for hard problems), these solutions aren't very satisfactory.

What I do is use a combination of DDD and bashdb. The former executes the latter, and the latter executes your script. This provides a multi-window UI with the ability to step through code in context and view variables, stack, etc., without the constant mental effort to maintain context in your head or keep re-listing the source.

There is guidance on setting that up here: http://ubuntuforums.org/showthread.php?t=660223

Proper way to initialize a C# dictionary with values?

With ?# 6.0

var myDict = new Dictionary<string, string>
{
    ["Key1"] = "Value1",
    ["Key2"] = "Value2"
};

How to display loading message when an iFrame is loading?

I have followed the following approach

First, add sibling div

$('<div class="loading"></div>').insertBefore("#Iframe");

and then when the iframe completed loading

$("#Iframe").load(function(){
   $(this).siblings(".loading-fetching-content").remove(); 
  });

How do you add a JToken to an JObject?

TL;DR: You should add a JProperty to a JObject. Simple. The index query returns a JValue, so figure out how to get the JProperty instead :)


The accepted answer is not answering the question as it seems. What if I want to specifically add a JProperty after a specific one? First, lets start with terminologies which really had my head worked up.

  • JToken = The mother of all other types. It can be A JValue, JProperty, JArray, or JObject. This is to provide a modular design to the parsing mechanism.
  • JValue = any Json value type (string, int, boolean).
  • JProperty = any JValue or JContainer (see below) paired with a name (identifier). For example "name":"value".
  • JContainer = The mother of all types which contain other types (JObject, JValue).
  • JObject = a JContainer type that holds a collection of JProperties
  • JArray = a JContainer type that holds a collection JValue or JContainer.

Now, when you query Json item using the index [], you are getting the JToken without the identifier, which might be a JContainer or a JValue (requires casting), but you cannot add anything after it, because it is only a value. You can change it itself, query more deep values, but you cannot add anything after it for example.

What you actually want to get is the property as whole, and then add another property after it as desired. For this, you use JOjbect.Property("name"), and then create another JProperty of your desire and then add it after this using AddAfterSelf method. You are done then.

For more info: http://www.newtonsoft.com/json/help/html/ModifyJson.htm

This is the code I modified.

public class Program
{
  public static void Main()
  {
    try
    {
      string jsonText = @"
      {
        ""food"": {
          ""fruit"": {
            ""apple"": {
              ""colour"": ""red"",
              ""size"": ""small""
            },
            ""orange"": {
              ""colour"": ""orange"",
              ""size"": ""large""
            }
          }
        }
      }";

      var foodJsonObj = JObject.Parse(jsonText);
      var bananaJson = JObject.Parse(@"{ ""banana"" : { ""colour"": ""yellow"", ""size"": ""medium""}}");

      var fruitJObject = foodJsonObj["food"]["fruit"] as JObject;
      fruitJObject.Property("orange").AddAfterSelf(new JProperty("banana", fruitJObject));

      Console.WriteLine(foodJsonObj.ToString());
    }
    catch (Exception ex)
    {
      Console.WriteLine(ex.GetType().Name + ": " + ex.Message);
    }
  }
}

How to check a not-defined variable in JavaScript

We can check undefined as follows

var x; 

if (x === undefined) {
    alert("x is undefined");
} else {
     alert("x is defined");
}

Create array of all integers between two numbers, inclusive, in Javascript/jQuery

In JavaScript ES6:

_x000D_
_x000D_
function range(start, end) {_x000D_
  return Array(end - start + 1).fill().map((_, idx) => start + idx)_x000D_
}_x000D_
var result = range(9, 18); // [9, 10, 11, 12, 13, 14, 15, 16, 17, 18]_x000D_
console.log(result);
_x000D_
_x000D_
_x000D_

For completeness, here it is with an optional step parameter.

_x000D_
_x000D_
function range(start, end, step = 1) {_x000D_
  const len = Math.floor((end - start) / step) + 1_x000D_
  return Array(len).fill().map((_, idx) => start + (idx * step))_x000D_
}_x000D_
var result = range(9, 18, 0.83);_x000D_
console.log(result);
_x000D_
_x000D_
_x000D_

I would use range-inclusive from npm in an actual project. It even supports backwards steps, so that's cool.

what is the difference between XSD and WSDL

XSD : XML Schema Definition.

XML : eXtensible Markup Language.

WSDL : Web Service Definition Language.

I am not going to answer in technical terms. I am aiming this explanation at beginners.

It is not easy to communicate between two different applications that are developed using two different technologies. For example, a company in Chicago might develop a web application using Java and another company in New York might develop an application in C# and when these two companies decided to share information then XML comes into picture. It helps to store and transport data between two different applications that are developed using different technologies. Note: It is not limited to a programming language, please do research on the information transportation between two different apps.

XSD is a schema definition. By that what I mean is, it is telling users to develop their XML in such a schema. Please see below images, and please watch closely with "load-on-startup" element and its type which is integer. In the XSD image you can see it is meant to be integer value for the "load-on-startup" and hence when user created his/her XML they passed an int value to that particular element. As a reminder, XSD is a schema and style whereas XML is a form to communicate with another application or system. One has to see XSD and create XML in such a way or else it won't communicate with another application or system which has been developed with a different technology. A company in Chicago provides a XSD template for a company in Texas to write or generate their XML in the given XSD format. If the company in Texas failed to adhere with those rules or schema mentioned in XSD then it is impossible to expect correct information from the company in Chicago. There is so much to do after the above said story, which an amateur or newbie have to know while coding for some thing like I said above. If you really want to know what happens later then it is better to sit with senior software engineers who actually developed web services. Next comes WSDL, please follow the images and try to figure out where the WSDL will fit in.

***************========Below is partial XML image ==========*************** XML image partial

***************========Below is partial XSD image ==========***************

XSD image partial

***************========Below is the partial WSDL image =======*************

WSDL image partial

I had to create a sample WSDL for a web service called Book. Note, it is an XSD but you have to call it WSDL (Web Service Definition Language) because it is very specific for Web Services. The above WSDL (or in other words XSD) is created for a class called Book.java and it has created a SOAP service. How the SOAP web service created it is a different topic. One has to write a Java class and before executing it create as a web service the user has to make sure Axis2 API is installed and Tomcat to host web service is in place.

As a servicer (the one who allows others (clients) to access information or data from their systems ) actually gives the client (the one who needs to use servicer information or data) complete access to data through a Web Service, because no company on the earth willing to expose their Database for outsiders. Like my company, decided to give some information about products via Web Services, hence we had to create XSD template and pass-on to few of our clients who wants to work with us. They have to write some code to make complete use of the given XSD and make Web Service calls to fetch data from servicer and convert data returned into their suitable requirement and then display or publish data or information about the product on their website. A simple example would be FLIGHT Ticket booking. An airline will let third parties to use flight data on their site for ticket sales. But again there is much more to it, it is just not letting third party flight ticket agent to sell tickets, there will be synchronize and security in place. If there is no sync then there is 100 % chances more than 1 customer might buy same flight ticket from various sources.

I am hoping experts will contribute to my answer. It is really hard for newbie or novice to understand XML, XSD and then to work on Web Services.

Is it possible to pass a flag to Gulp to have it run tasks in different ways?

It has been some time since this question has been posted, but maybe it will help someone.

I am using GULP CLI 2.0.1 (installed globally) and GULP 4.0.0 (installed locally) here is how you do it without any additional plugin. I think the code is quite self-explanatory.

var cp = require('child_process'), 
{ src, dest, series, parallel, watch } = require('gulp');

// == availableTasks: log available tasks to console
function availableTasks(done) {
  var command = 'gulp --tasks-simple';
  if (process.argv.indexOf('--verbose') > -1) {
    command = 'gulp --tasks';
  }
  cp.exec(command, function(err, stdout, stderr) {
    done(console.log('Available tasks are:\n' + stdout));
  });
}
availableTasks.displayName = 'tasks';
availableTasks.description = 'Log available tasks to console as plain text list.';
availableTasks.flags = {
  '--verbose': 'Display tasks dependency tree instead of plain text list.'
};
exports.availableTasks = availableTasks;

And run from the console:

gulp availableTasks

Then run and see the differences:

gulp availableTasks --verbose

Scanner is skipping nextLine() after using next() or nextFoo()?

If you want to read both strings and ints, a solution is to use two Scanners:

Scanner stringScanner = new Scanner(System.in);
Scanner intScanner = new Scanner(System.in);

intScanner.nextInt();
String s = stringScanner.nextLine(); // unaffected by previous nextInt()
System.out.println(s);

intScanner.close();
stringScanner.close();

How to format a DateTime in PowerShell

I needed the time and a slight variation on format. This works great for my purposes:

$((get-date).ToLocalTime()).ToString("yyyy-MM-dd HHmmss")

2019-08-16 215757

According to @mklement0 in comments, this should yield the same result:

(get-date).ToString("yyyy-MM-dd HHmmss")

How do I force my .NET application to run as administrator?

You'll want to modify the manifest that gets embedded in the program. This works on Visual Studio 2008 and higher: Project + Add New Item, select "Application Manifest File". Change the <requestedExecutionLevel> element to:

 <requestedExecutionLevel level="requireAdministrator" uiAccess="false" />

The user gets the UAC prompt when they start the program. Use wisely; their patience can wear out quickly.

How to get table list in database, using MS SQL 2008?

This query will get you all the tables in the database

USE [DatabaseName];

SELECT * FROM information_schema.tables;

Javascript : array.length returns undefined

An easy fix to this question is to add '[' in the start of your json file, and ending it with a ']'. This solved it for me.

Uploading Images to Server android

use below code it helps you....

        BitmapFactory.Options options = new BitmapFactory.Options();

        options.inSampleSize = 4;
        options.inPurgeable = true;
        Bitmap bm = BitmapFactory.decodeFile("your path of image",options);

        ByteArrayOutputStream baos = new ByteArrayOutputStream();

        bm.compress(Bitmap.CompressFormat.JPEG,40,baos); 


        // bitmap object

        byteImage_photo = baos.toByteArray();

                    //generate base64 string of image

                   String encodedImage =Base64.encodeToString(byteImage_photo,Base64.DEFAULT);

  //send this encoded string to server

Best timestamp format for CSV/Excel?

"yyyy-mm-dd hh:mm:ss.000" format does not work in all locales. For some (at least Danish) "yyyy-mm-dd hh:mm:ss,000" will work better.

as replied by user662894.

I want to add: Don't try to get the microseconds from, say, SQL Server's datetime2 datatype: Excel can't handle more than 3 fractional seconds (i.e. milliseconds).

So "yyyy-mm-dd hh:mm:ss.000000" won't work, and when Excel is fed this kind of string (from the CSV file), it will perform rounding rather than truncation.

This may be fine except when microsecond precision matters, in which case you are better off by NOT triggering an automatic datatype recognition but just keep the string as string...

How to check if AlarmManager already has an alarm set?

Note this quote from the docs for the set method of the Alarm Manager:

If there is already an alarm for this Intent scheduled (with the equality of two intents being defined by Intent.filterEquals), then it will be removed and replaced by this one.

If you know you want the alarm set, then you don't need to bother checking whether it already exists or not. Just create it every time your app boots. You will replace any past alarms with the same Intent.

You need a different approach if you are trying to calculate how much time is remaining on a previously created alarm, or if you really need to know whether such alarm even exists. To answer those questions, consider saving shared pref data at the time you create the alarm. You could store the clock timestamp at the moment the alarm was set, the time that you expect the alarm to go off, and the repeat period (if you setup a repeating alarm).

C# - Multiple generic types in one list

I have also used a non-generic version, using the new keyword:

public interface IMetadata
{
    Type DataType { get; }

    object Data { get; }
}

public interface IMetadata<TData> : IMetadata
{
    new TData Data { get; }
}

Explicit interface implementation is used to allow both Data members:

public class Metadata<TData> : IMetadata<TData>
{
    public Metadata(TData data)
    {
       Data = data;
    }

    public Type DataType
    {
        get { return typeof(TData); }
    }

    object IMetadata.Data
    {
        get { return Data; }
    }

    public TData Data { get; private set; }
}

You could derive a version targeting value types:

public interface IValueTypeMetadata : IMetadata
{

}

public interface IValueTypeMetadata<TData> : IMetadata<TData>, IValueTypeMetadata where TData : struct
{

}

public class ValueTypeMetadata<TData> : Metadata<TData>, IValueTypeMetadata<TData> where TData : struct
{
    public ValueTypeMetadata(TData data) : base(data)
    {}
}

This can be extended to any kind of generic constraints.

getting the error: expected identifier or ‘(’ before ‘{’ token

you need to place the opening brace after main , not before it

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

int main(void)
{

Flutter Circle Design

I would use a https://docs.flutter.io/flutter/widgets/Stack-class.html to be able to freely position widgets.

To create circles

  new BoxDecoration(
    color: effectiveBackgroundColor,
    image: backgroundImage != null
      ? new DecorationImage(image: backgroundImage, fit: BoxFit.cover)
      : null,
    shape: BoxShape.circle,
  ),

and https://docs.flutter.io/flutter/widgets/Transform/Transform.rotate.html to position the white dots.

Make the first character Uppercase in CSS

<script type="text/javascript">
     $(document).ready(function() {
     var asdf = $('.capsf').text();

    $('.capsf').text(asdf.toLowerCase());
     });
     </script>
<div style="text-transform: capitalize;"  class="capsf">sd GJHGJ GJHgjh gh hghhjk ku</div>

How can I get the status code from an http error in Axios?

You can put the error into an object and log the object, like this:

axios.get('foo.com')
    .then((response) => {})
    .catch((error) => {
        console.log({error}) // this will log an empty object with an error property
    });

Hope this help someone out there.

Java Error: illegal start of expression

Remove the public keyword from int[] locations={1,2,3};. An access modifier isn't allowed inside a method, as its accessbility is defined by its method scope.

If your goal is to use this reference in many a method, you might want to move the declaration outside the method.

Youtube - How to force 480p video quality in embed link / <iframe>

I found that as of May, 2012, if you set the frame size so that the minimum pixel area (width • height) is above a certain threshold, it bumps the quality up from 360p to 480p, if you're video is at least 640 x 360.

I've discovered that setting a frame size to 780 x 480 for the embed frame triggers the 480p quality, without distorting the video (scaling up). 640 x 585 also works in this manner. I also used the &hd=1 parameter, but I doubt this has much control if your video is not uploaded in HD (720p or higher).

For instance:

<iframe width="780" height="480" src="http://www.youtube.com/embed/[VIDEO-ID]?rel=0&fs=1&showinfo=0&autohide=1&hd=1"></iframe>

Of course, the drawback is that by setting these static frame dimensions, you will most likely get black bars on the sides or above and below, depending on what you prefer.

If you didn't care about the controls being cut-off, you could go on to use CSS and overflow: hidden to crop the black bars out of the frame, providing you know the exact dimensions of the video.

Hope this helps, and hope the Embed method soon gets discrete quality parameters again one day!

How to generate entire DDL of an Oracle schema (scriptable)?

If you want to individually generate ddl for each object,

Queries are:

--GENERATE DDL FOR ALL USER OBJECTS

--1. FOR ALL TABLES

SELECT DBMS_METADATA.GET_DDL('TABLE', TABLE_NAME) FROM USER_TABLES;

--2. FOR ALL INDEXES

SELECT DBMS_METADATA.GET_DDL('INDEX', INDEX_NAME) FROM USER_INDEXES WHERE INDEX_TYPE ='NORMAL';

--3. FOR ALL VIEWS

SELECT DBMS_METADATA.GET_DDL('VIEW', VIEW_NAME) FROM USER_VIEWS;

OR

SELECT TEXT FROM USER_VIEWS

--4. FOR ALL MATERILIZED VIEWS

SELECT QUERY FROM USER_MVIEWS

--5. FOR ALL FUNCTION

SELECT DBMS_METADATA.GET_DDL('FUNCTION', OBJECT_NAME) FROM USER_PROCEDURES WHERE OBJECT_TYPE = 'FUNCTION'

===============================================================================================

GET_DDL Function doesnt support for some object_type like LOB,MATERIALIZED VIEW, TABLE PARTITION

SO, Consolidated query for generating DDL will be:

SELECT OBJECT_TYPE, OBJECT_NAME,DBMS_METADATA.GET_DDL(OBJECT_TYPE, OBJECT_NAME, OWNER)
  FROM ALL_OBJECTS 
  WHERE (OWNER = 'XYZ') AND OBJECT_TYPE NOT IN('LOB','MATERIALIZED VIEW', 'TABLE PARTITION') ORDER BY OBJECT_TYPE, OBJECT_NAME;

XAMPP keeps showing Dashboard/Welcome Page instead of the Configuration Page

Open the htdocs folder there will be index.php file. In that file script is written to go in dashboard folder and show dashboard. So you just have to comment it or delete that script and write any code save it and run http://localhost now dashboard screen will not open and you will see what you have written in that file.

sqlalchemy: how to join several tables by one query?

Expanding on Abdul's answer, you can obtain a KeyedTuple instead of a discrete collection of rows by joining the columns:

q = Session.query(*User.__table__.columns + Document.__table__.columns).\
        select_from(User).\
        join(Document, User.email == Document.author).\
        filter(User.email == 'someemail').all()

How to change the data type of a column without dropping the column with query?

ALTER TABLE YourTableNameHere ALTER COLUMN YourColumnNameHere VARCHAR(20)

How do I format a Microsoft JSON date?

Just to add another approach here, the "ticks approach" that WCF takes is prone to problems with timezones if you're not extremely careful such as described here and in other places. So I'm now using the ISO 8601 format that both .NET & JavaScript duly support that includes timezone offsets. Below are the details:

In WCF/.NET:

Where CreationDate is a System.DateTime; ToString("o") is using .NET's Round-trip format specifier that generates an ISO 8601-compliant date string

new MyInfo {
    CreationDate = r.CreationDate.ToString("o"),
};

In JavaScript

Just after retrieving the JSON I go fixup the dates to be JavaSript Date objects using the Date constructor which accepts an ISO 8601 date string...

$.getJSON(
    "MyRestService.svc/myinfo",
    function (data) {
        $.each(data.myinfos, function (r) {
            this.CreatedOn = new Date(this.CreationDate);
        });
        // Now each myinfo object in the myinfos collection has a CreatedOn field that is a real JavaScript date (with timezone intact).
       alert(data.myinfos[0].CreationDate.toLocaleString());
    }
)

Once you have a JavaScript date you can use all the convenient and reliable Date methods like toDateString, toLocaleString, etc.

How to get the indexpath.row when an element is activated?

My approach to this sort of problem is to use a delegate protocol between the cell and the tableview. This allows you to keep the button handler in the cell subclass, which enables you to assign the touch up action handler to the prototype cell in Interface Builder, while still keeping the button handler logic in the view controller.

It also avoids the potentially fragile approach of navigating the view hierarchy or the use of the tag property, which has issues when cells indexes change (as a result of insertion, deletion or reordering)

CellSubclass.swift

protocol CellSubclassDelegate: class {
    func buttonTapped(cell: CellSubclass)
}

class CellSubclass: UITableViewCell {

@IBOutlet var someButton: UIButton!

weak var delegate: CellSubclassDelegate?

override func prepareForReuse() {
    super.prepareForReuse()
    self.delegate = nil
}

@IBAction func someButtonTapped(sender: UIButton) {
    self.delegate?.buttonTapped(self)
}

ViewController.swift

class MyViewController: UIViewController, CellSubclassDelegate {

    @IBOutlet var tableview: UITableView!

    func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {

        let cell = tableView.dequeueReusableCellWithIdentifier("Cell", forIndexPath: indexPath) as! CellSubclass

        cell.delegate = self

        // Other cell setup

    } 

    //  MARK: CellSubclassDelegate

    func buttonTapped(cell: CellSubclass) {
        guard let indexPath = self.tableView.indexPathForCell(cell) else {
            // Note, this shouldn't happen - how did the user tap on a button that wasn't on screen?
            return
        }

        //  Do whatever you need to do with the indexPath

        print("Button tapped on row \(indexPath.row)")
    }
} 

How to use a dot "." to access members of dictionary?

Install dotmap via pip

pip install dotmap

It does everything you want it to do and subclasses dict, so it operates like a normal dictionary:

from dotmap import DotMap

m = DotMap()
m.hello = 'world'
m.hello
m.hello += '!'
# m.hello and m['hello'] now both return 'world!'
m.val = 5
m.val2 = 'Sam'

On top of that, you can convert it to and from dict objects:

d = m.toDict()
m = DotMap(d) # automatic conversion in constructor

This means that if something you want to access is already in dict form, you can turn it into a DotMap for easy access:

import json
jsonDict = json.loads(text)
data = DotMap(jsonDict)
print data.location.city

Finally, it automatically creates new child DotMap instances so you can do things like this:

m = DotMap()
m.people.steve.age = 31

Comparison to Bunch

Full disclosure: I am the creator of the DotMap. I created it because Bunch was missing these features

  • remembering the order items are added and iterating in that order
  • automatic child DotMap creation, which saves time and makes for cleaner code when you have a lot of hierarchy
  • constructing from a dict and recursively converting all child dict instances to DotMap

Hashing with SHA1 Algorithm in C#

public string Hash(byte [] temp)
{
    using (SHA1Managed sha1 = new SHA1Managed())
    {
        var hash = sha1.ComputeHash(temp);
        return Convert.ToBase64String(hash);
    }
}

EDIT:

You could also specify the encoding when converting the byte array to string as follows:

return System.Text.Encoding.UTF8.GetString(hash);

or

return System.Text.Encoding.Unicode.GetString(hash);

C Programming: How to read the whole file contents into a buffer

Here is what I would recommend.

It should conform to C89, and be completely portable. In particular, it works also on pipes and sockets on POSIXy systems.

The idea is that we read the input in large-ish chunks (READALL_CHUNK), dynamically reallocating the buffer as we need it. We only use realloc(), fread(), ferror(), and free():

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

/* Size of each input chunk to be
   read and allocate for. */
#ifndef  READALL_CHUNK
#define  READALL_CHUNK  262144
#endif

#define  READALL_OK          0  /* Success */
#define  READALL_INVALID    -1  /* Invalid parameters */
#define  READALL_ERROR      -2  /* Stream error */
#define  READALL_TOOMUCH    -3  /* Too much input */
#define  READALL_NOMEM      -4  /* Out of memory */

/* This function returns one of the READALL_ constants above.
   If the return value is zero == READALL_OK, then:
     (*dataptr) points to a dynamically allocated buffer, with
     (*sizeptr) chars read from the file.
     The buffer is allocated for one extra char, which is NUL,
     and automatically appended after the data.
   Initial values of (*dataptr) and (*sizeptr) are ignored.
*/
int readall(FILE *in, char **dataptr, size_t *sizeptr)
{
    char  *data = NULL, *temp;
    size_t size = 0;
    size_t used = 0;
    size_t n;

    /* None of the parameters can be NULL. */
    if (in == NULL || dataptr == NULL || sizeptr == NULL)
        return READALL_INVALID;

    /* A read error already occurred? */
    if (ferror(in))
        return READALL_ERROR;

    while (1) {

        if (used + READALL_CHUNK + 1 > size) {
            size = used + READALL_CHUNK + 1;

            /* Overflow check. Some ANSI C compilers
               may optimize this away, though. */
            if (size <= used) {
                free(data);
                return READALL_TOOMUCH;
            }

            temp = realloc(data, size);
            if (temp == NULL) {
                free(data);
                return READALL_NOMEM;
            }
            data = temp;
        }

        n = fread(data + used, 1, READALL_CHUNK, in);
        if (n == 0)
            break;

        used += n;
    }

    if (ferror(in)) {
        free(data);
        return READALL_ERROR;
    }

    temp = realloc(data, used + 1);
    if (temp == NULL) {
        free(data);
        return READALL_NOMEM;
    }
    data = temp;
    data[used] = '\0';

    *dataptr = data;
    *sizeptr = used;

    return READALL_OK;
}

Above, I've used a constant chunk size, READALL_CHUNK == 262144 (256*1024). This means that in the worst case, up to 262145 chars are wasted (allocated but not used), but only temporarily. At the end, the function reallocates the buffer to the optimal size. Also, this means that we do four reallocations per megabyte of data read.

The 262144-byte default in the code above is a conservative value; it works well for even old minilaptops and Raspberry Pis and most embedded devices with at least a few megabytes of RAM available for the process. Yet, it is not so small that it slows down the operation (due to many read calls, and many buffer reallocations) on most systems.

For desktop machines at this time (2017), I recommend a much larger READALL_CHUNK, perhaps #define READALL_CHUNK 2097152 (2 MiB).

Because the definition of READALL_CHUNK is guarded (i.e., it is defined only if it is at that point in the code still undefined), you can override the default value at compile time, by using (in most C compilers) -DREADALL_CHUNK=2097152 command-line option -- but do check your compiler options for defining a preprocessor macro using command-line options.

Each GROUP BY expression must contain at least one column that is not an outer reference

Well, as it was said before, you can't GROUP by literals, I think that you are confused cause you can ORDER by 1, 2, 3. When you use functions as your columns, you need to GROUP by the same expression. Besides, the HAVING clause is wrong, you can only use what is in the agreggations. In this case, your query should be like this:

SELECT 
LEFT(SUBSTRING(batchinfo.datapath, PATINDEX('%[0-9][0-9][0-9]%', batchinfo.datapath), 8000), PATINDEX('%[^0-9]%', SUBSTRING(batchinfo.datapath, PATINDEX('%[0-9][0-9][0-9]%', batchinfo.datapath), 8000))-1),
qvalues.name,
qvalues.compound,
MAX(qvalues.rid) MaxRid
FROM batchinfo join qvalues 
ON batchinfo.rowid=qvalues.rowid
WHERE LEN(datapath)>4
GROUP BY 
LEFT(SUBSTRING(batchinfo.datapath, PATINDEX('%[0-9][0-9][0-9]%', batchinfo.datapath), 8000), PATINDEX('%[^0-9]%', SUBSTRING(batchinfo.datapath, PATINDEX('%[0-9][0-9][0-9]%', batchinfo.datapath), 8000))-1),
qvalues.name,
qvalues.compound

NULL value for int in Update statement

By using NULL without any quotes.

UPDATE `tablename` SET `fieldName` = NULL;

javascript remove "disabled" attribute from html input

method 1 <input type="text" onclick="this.disabled=false;" disabled>
<hr>
method 2 <input type="text" onclick="this.removeAttribute('disabled');" disabled>
<hr>
method 3 <input type="text" onclick="this.removeAttribute('readonly');" readonly>

code of the previous answers don't seem to work in inline mode, but there is a workaround: method 3.

see demo https://jsfiddle.net/eliz82/xqzccdfg/

Find and replace words/lines in a file

public static void replaceFileString(String old, String new) throws IOException {
    String fileName = Settings.getValue("fileDirectory");
    FileInputStream fis = new FileInputStream(fileName);
    String content = IOUtils.toString(fis, Charset.defaultCharset());
    content = content.replaceAll(old, new);
    FileOutputStream fos = new FileOutputStream(fileName);
    IOUtils.write(content, new FileOutputStream(fileName), Charset.defaultCharset());
    fis.close();
    fos.close();
}

above is my implementation of Meriton's example that works for me. The fileName is the directory (ie. D:\utilities\settings.txt). I'm not sure what character set should be used, but I ran this code on a Windows XP machine just now and it did the trick without doing that temporary file creation and renaming stuff.

Compile error: package javax.servlet does not exist

In a linux environment the soft link apparently does not work. you must use the physical path. for instance on my machine I have a softlink at /usr/share/tomacat7/lib/servlet-api.jar and using this as my classpath argument led to a failed compile with the same error. instead I had to use /usr/share/java/tomcat-servlet-api-3.0.jar which is the file that the soft link pointed to.

How many files can I put in a directory?

For what it's worth, I just created a directory on an ext4 file system with 1,000,000 files in it, then randomly accessed those files through a web server. I didn't notice any premium on accessing those over (say) only having 10 files there.

This is radically different from my experience doing this on ntfs a few years back.

How to convert map to url query string?

Kotlin

mapOf(
  "param1" to 12,
  "param2" to "cat"
).map { "${it.key}=${it.value}" }
  .joinToString("&")

log4net vs. Nlog

Based on my experience, SmartInspect beats both NLog and log4net.

Its extremely easy to use, documentation is great, and you can view and filter previously logged messages with their interactive log viewer, which is a huge real world advantage.

One thing I like is the tabbed views of data, like the browser tabs in Chrome. Each tab can provide a different filtered view of the log.

How to detect when cancel is clicked on file input?

Most of these solutions don't work for me.

The problem is that you never know which event will be triggered fist, is it click or is it change? You can't assume any order, because it probably depends on the browser's implementation.

At least in Opera and Chrome (late 2015) click is triggered just before 'filling' input with files, so you will never know the length of files.length != 0 until you delay click to be triggered after change.

Here is code:

var inputfile = $("#yourid");

inputfile.on("change click", function(ev){
    if (ev.originalEvent != null){
        console.log("OK clicked");
    }
    document.body.onfocus = function(){
        document.body.onfocus = null;
        setTimeout(function(){
            if (inputfile.val().length === 0) console.log("Cancel clicked");
        }, 1000);
    };
});

Select a dummy column with a dummy value in SQL?

Try this:

select col1, col2, 'ABC' as col3 from Table1 where col1 = 0;

Is there a way to remove unused imports and declarations from Angular 2+?

As of Visual Studio Code Release 1.22 this comes free without the need of an extension.

Shift+Alt+O will take care of you.

rsync error: failed to set times on "/foo/bar": Operation not permitted

The problem in my case was that the "receiver mountpoint" was incorrectly mounted. It was in read-only mode (for some extrange reason). It looked like rsync was copying the files, but it was not. I checked my fstab file and changed mount options to default, re-mount file system and execute rsync again. All fine then.

How to upgrade docker-compose to latest version

If you tried sudo apt-get remove docker-compose and get E: Unable to locate package docker-compose, try this method :

This command must return a result, in order to check it is installed here :

ls -l /usr/local/bin/docker-compose

Remove the old version :

sudo rm -rf docker-compose

Download the last version (check official repo : docker/compose/releases) :

sudo curl -L "https://github.com/docker/compose/releases/download/1.24.0/docker-compose-$(uname -s)-$(uname -m)" -o /usr/local/bin/docker-compose

(replace 1.24.0 if needed)

Finally, apply executable permissions to the binary:

sudo chmod +x /usr/local/bin/docker-compose

Check version :

docker-compose -v

SQL ON DELETE CASCADE, Which Way Does the Deletion Occur?

Cascade will work when you delete something on table Courses. Any record on table BookCourses that has reference to table Courses will be deleted automatically.

But when you try to delete on table BookCourses only the table itself is affected and not on the Courses

follow-up question: why do you have CourseID on table Category?

Maybe you should restructure your schema into this,

CREATE TABLE Categories 
(
  Code CHAR(4) NOT NULL PRIMARY KEY,
  CategoryName VARCHAR(63) NOT NULL UNIQUE
);

CREATE TABLE Courses 
(
  CourseID INT NOT NULL PRIMARY KEY,
  BookID INT NOT NULL,
  CatCode CHAR(4) NOT NULL,
  CourseNum CHAR(3) NOT NULL,
  CourseSec CHAR(1) NOT NULL,
);

ALTER TABLE Courses
ADD FOREIGN KEY (CatCode)
REFERENCES Categories(Code)
ON DELETE CASCADE;

How to query between two dates using Laravel and Eloquent?

The following should work:

$now = date('Y-m-d');
$reservations = Reservation::where('reservation_from', '>=', $now)
                           ->where('reservation_from', '<=', $to)
                           ->get();

SVN: Folder already under version control but not comitting?

(1) This just happened to me, and I thought it was interesting how it happened. Basically I had copied the folder to a new location and modified it, forgetting that it would bring along all the hidden .svn directories. Once you realize how it happens it is easier to avoid in the future.

(2) Removing the .svn directories is the solution, but you have to do it recursively all the way down the directory tree. The easiest way to do that is:

find troublesome_folder -name .svn -exec rm -rf {} \;

How get data from material-ui TextField, DropDownMenu components?

Here's the simplest solution i came up with, we get the value of the input created by material-ui textField :

      create(e) {
        e.preventDefault();
        let name = this.refs.name.input.value;
        alert(name);
      }

      constructor(){
        super();
        this.create = this.create.bind(this);
      }

      render() {
        return (
              <form>
                <TextField ref="name" hintText="" floatingLabelText="Your name" /><br/>
                <RaisedButton label="Create" onClick={this.create} primary={true} />
              </form>
        )}

hope this helps.

Formatting text in a TextBlock

You need to use Inlines:

<TextBlock.Inlines>
    <Run FontWeight="Bold" FontSize="14" Text="This is WPF TextBlock Example. " />
    <Run FontStyle="Italic" Foreground="Red" Text="This is red text. " />
</TextBlock.Inlines>

With binding:

<TextBlock.Inlines>
    <Run FontWeight="Bold" FontSize="14" Text="{Binding BoldText}" />
    <Run FontStyle="Italic" Foreground="Red" Text="{Binding ItalicText}" />
</TextBlock.Inlines>

You can also bind the other properties:

<TextBlock.Inlines>
    <Run FontWeight="{Binding Weight}"
         FontSize="{Binding Size}"
         Text="{Binding LineOne}" />
    <Run FontStyle="{Binding Style}"
         Foreground="Binding Colour}"
         Text="{Binding LineTwo}" />
</TextBlock.Inlines>

You can bind through converters if you have bold as a boolean (say).

Angular: conditional class with *ngClass

You can use [ngClass] or [class.classname], both will work the same.
[class.my-class]="step==='step1'"

   OR

[ngClass]="{'my-class': step=='step1'}"

Both will work the same!

Project has no default.properties file! Edit the project properties to set one

"default.properties" is renamed as "project.properties". You can reach "Package Explorer" -> "MyXXXXXApp" -> "project.properties"

Calling a particular PHP function on form submit

In the following line

<form method="post" action="display()">

the action should be the name of your script and you should call the function, Something like this

<form method="post" action="yourFileName.php">
    <input type="text" name="studentname">
    <input type="submit" value="click" name="submit"> <!-- assign a name for the button -->
</form>

<?php
function display()
{
    echo "hello ".$_POST["studentname"];
}
if(isset($_POST['submit']))
{
   display();
} 
?>

jQuery Ajax error handling, show custom exception messages

If making a call to asp.net, this will return the error message title:

I didn't write all of formatErrorMessage myself but i find it very useful.

function formatErrorMessage(jqXHR, exception) {

    if (jqXHR.status === 0) {
        return ('Not connected.\nPlease verify your network connection.');
    } else if (jqXHR.status == 404) {
        return ('The requested page not found. [404]');
    } else if (jqXHR.status == 500) {
        return ('Internal Server Error [500].');
    } else if (exception === 'parsererror') {
        return ('Requested JSON parse failed.');
    } else if (exception === 'timeout') {
        return ('Time out error.');
    } else if (exception === 'abort') {
        return ('Ajax request aborted.');
    } else {
        return ('Uncaught Error.\n' + jqXHR.responseText);
    }
}


var jqxhr = $.post(addresshere, function() {
  alert("success");
})
.done(function() { alert("second success"); })
.fail(function(xhr, err) { 

    var responseTitle= $(xhr.responseText).filter('title').get(0);
    alert($(responseTitle).text() + "\n" + formatErrorMessage(xhr, err) ); 
})

Most useful NLog configurations

Treating exceptions differently

We often want to get more information when there is an exception. The following configuration has two targets, a file and the console, which filter on whether or not there is any exception info. (EDIT: Jarek has posted about a new method of doing this in vNext.)

The key is to have a wrapper target with xsi:type="FilteringWrapper" condition="length('${exception}')>0"

<nlog xmlns="http://www.nlog-project.org/schemas/NLog.mono2.xsd"
      xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
      autoReload="true"
      internalLogLevel="Warn"
      internalLogFile="nlog log.log"
      >
    <variable name="VerboseLayout" 
              value="${longdate} ${level:upperCase=true} ${message}  
                    (${callsite:includSourcePath=true})"            />
    <variable name="ExceptionVerboseLayout"  
              value="${VerboseLayout} (${stacktrace:topFrames=10})  
                     ${exception:format=ToString}"                  />

    <targets async="true">
        <target name="file" xsi:type="File" fileName="log.log"
                layout="${VerboseLayout}">
        </target>

        <target name="fileAsException"  
                xsi:type="FilteringWrapper" 
                condition="length('${exception}')>0">
            <target xsi:type="File"  
                    fileName="log.log"  
                    layout="${ExceptionVerboseLayout}" />
        </target>

        <target xsi:type="ColoredConsole"
                name="console"
                layout="${NormalLayout}"/>

        <target xsi:type="FilteringWrapper"  
                condition="length('${exception}')>0"  
                name="consoleException">
            <target xsi:type="ColoredConsole" 
                    layout="${ExceptionVerboseLayout}" />
        </target>
    </targets>

    <rules>
        <logger name="*" minlevel="Trace" writeTo="console,consoleException" />
        <logger name="*" minlevel="Warn" writeTo="file,fileAsException" />
    </rules>

</nlog>

Case insensitive string as HashMap key

Because of this, I'm creating a new object of CaseInsensitiveString for every event. So, it might hit performance.

Creating wrappers or converting key to lower case before lookup both create new objects. Writing your own java.util.Map implementation is the only way to avoid this. It's not too hard, and IMO is worth it. I found the following hash function to work pretty well, up to few hundred keys.

static int ciHashCode(String string)
{
    // length and the low 5 bits of hashCode() are case insensitive
    return (string.hashCode() & 0x1f)*33 + string.length();
}