Programs & Examples On #Tibco rv

Tibco Rendezvous is a commercial message bus product for enterprise application integration (EAI) sold by the TIBCO company.

How to make an empty div take space

Simply add a zero width space character inside a pseudo element

.class:after {
    content: '\200b';
}

java.util.Date format conversion yyyy-mm-dd to mm-dd-yyyy

Please change small "mm" month to capital "MM" it will work.for reference below is the sample code.

        Date myDate = new Date();
        SimpleDateFormat sm = new SimpleDateFormat("MM-dd-yyyy");
       
        String strDate = sm.format(myDate);
        
        Date dt = sm.parse(strDate);
        System.out.println(strDate);

Exporting PDF with jspdf not rendering CSS

Slight change to @rejesh-yadav wonderful answer.

html2canvas now returns a promise.

html2canvas(document.body).then(function (canvas) {
    var img = canvas.toDataURL("image/png");
    var doc = new jsPDF();
    doc.addImage(img, 'JPEG', 10, 10);
    doc.save('test.pdf');        
});

Hope this helps some!

How to print_r $_POST array?

$_POST is an array in itsself you don't need to make an array out of it. What you did is nest the $_POST array inside a new array. This is why you print Array. Change it to:

foreach ($_POST as $key => $value) {

  echo "<p>".$key."</p>";
  echo "<p>".$value."</p>";
  echo "<hr />";

} 

How to set default text for a Tkinter Entry widget

Use Entry.insert. For example:

try:
    from tkinter import *  # Python 3.x
except Import Error:
    from Tkinter import *  # Python 2.x

root = Tk()
e = Entry(root)
e.insert(END, 'default text')
e.pack()
root.mainloop()

Or use textvariable option:

try:
    from tkinter import *  # Python 3.x
except Import Error:
    from Tkinter import *  # Python 2.x

root = Tk()
v = StringVar(root, value='default text')
e = Entry(root, textvariable=v)
e.pack()
root.mainloop()

Bash array with spaces in elements

Escaping works.

#!/bin/bash

FILES=(2011-09-04\ 21.43.02.jpg
2011-09-05\ 10.23.14.jpg
2011-09-09\ 12.31.16.jpg
2011-09-11\ 08.43.12.jpg)

echo ${FILES[0]}
echo ${FILES[1]}
echo ${FILES[2]}
echo ${FILES[3]}

Output:

$ ./test.sh
2011-09-04 21.43.02.jpg
2011-09-05 10.23.14.jpg
2011-09-09 12.31.16.jpg
2011-09-11 08.43.12.jpg

Quoting the strings also produces the same output.

Can you explain the HttpURLConnection connection process?

On which point does HTTPURLConnection try to establish a connection to the given URL?

On the port named in the URL if any, otherwise 80 for HTTP and 443 for HTTPS. I believe this is documented.

On which point can I know that I was able to successfully establish a connection?

When you call getInputStream() or getOutputStream() or getResponseCode() without getting an exception.

Are establishing a connection and sending the actual request done in one step/method call? What method is it?

No and none.

Can you explain the function of getOutputStream() and getInputStream() in layman's term?

Either of them first connects if necessary, then returns the required stream.

I notice that when the server I'm trying to connect to is down, I get an Exception at getOutputStream(). Does it mean that HTTPURLConnection will only start to establish a connection when I invoke getOutputStream()? How about the getInputStream()? Since I'm only able to get the response at getInputStream(), then does it mean that I didn't send any request at getOutputStream() yet but simply establishes a connection? Do HttpURLConnection go back to the server to request for response when I invoke getInputStream()?

See above.

Am I correct to say that openConnection() simply creates a new connection object but does not establish any connection yet?

Yes.

How can I measure the read overhead and connect overhead?

Connect: take the time getInputStream() or getOutputStream() takes to return, whichever you call first. Read: time from starting first read to getting the EOS.

How to delete a file from SD card?

This works for me: (Delete image from Gallery)

File file = new File(photoPath);
file.delete();

context.sendBroadcast(new Intent(Intent.ACTION_MEDIA_SCANNER_SCAN_FILE, Uri.fromFile(new File(photoPath))));

How to fetch the row count for all tables in a SQL SERVER database

SELECT 
    sc.name +'.'+ ta.name TableName, SUM(pa.rows) RowCnt
FROM 
    sys.tables ta
INNER JOIN sys.partitions pa
    ON pa.OBJECT_ID = ta.OBJECT_ID
INNER JOIN sys.schemas sc
    ON ta.schema_id = sc.schema_id
WHERE ta.is_ms_shipped = 0 AND pa.index_id IN (1,0)
GROUP BY sc.name,ta.name
ORDER BY SUM(pa.rows) DESC

case statement in where clause - SQL Server

simply do the select:

Select * From Times
WHERE (StartDate <= @Date) AND (EndDate >= @Date) AND
((@day = 'Monday' AND (Monday = 1))
OR (@day = 'Tuesday' AND (Tuesday = 1))
OR (Wednesday = 1))

Set UIButton title UILabel font size programmatically

swift 4.x

button.titleLabel?.font = UIFont.systemFont(ofSize: 20)

Graphviz's executables are not found (Python 3.4)

In my case (Win10, Anaconda3, Jupyter notebook) after "conda install graphviz" I have to add to the PATH: C:\Users\username\Anaconda3\Library\bin\graphviz

To modify PATH goto Control Panel > System and Security > System > Advanced System Settings > Environment Variables > Path > Edit > New

Get public/external IP address?

using System.Net;

private string GetWorldIP()
{
    String url = "http://bot.whatismyipaddress.com/";
    String result = null;

    try
    {
        WebClient client = new WebClient();
        result = client.DownloadString(url);
        return result;
    }
    catch (Exception ex) { return "127.0.0.1"; }
}

Used loopback as fallback just so things don't fatally break.

Your configuration specifies to merge with the <branch name> from the remote, but no such ref was fetched.?

I just got the same error, when I didn't use the correct case. I could checkout out 'integration'. Git told me to perform a git pull to update my branch. I did that, but received the mentioned error. The correct branch name is 'Integration' with a capital 'I'. When I checked out that branch and pulled, it worked without problem.

How to call getResources() from a class which has no context?

It can easily be done if u had declared a class that extends from Application

This class will be like a singleton, so when u need a context u can get it just like this:

I think this is the better answer and the cleaner

Here is my code from Utilities package:

 public static String getAppNAme(){
     return MyOwnApplication.getInstance().getString(R.string.app_name);
 }

How do I "decompile" Java class files?

Update February 2016:

www.javadecompilers.com lists JAD as being:

the most popular Java decompiler, but primarily of this age only. Written in C++, so very fast.
Outdated, unsupported and does not decompile correctly Java 5 and later

So your mileage may vary with recent jdk (7, 8).

The same site list other tools.

And javadecompiler, as noted by Salvador Valencia in the comments (Sept 2017), offers a SaaS where you upload the .class file to the cloud and it returns you the decompiled code.


Original answer: Oct. 2008

  • The final release of JSR 176, defining the major features of J2SE 5.0 (Java SE 5), has been published on September 30, 2004.
  • The lastest Java version supported by JAD, the famous Java decompiler written by Mr. Pavel Kouznetsov, is JDK 1.3.
  • Most of the Java decompilers downloadable today from the Internet, such as “DJ Java Decompiler” or “Cavaj Java Decompiler”, are powered by JAD: they can not display Java 5 sources.

Java Decompiler (Yet another Fast Java decompiler) has:

  • Explicit support for decompiling and analyzing Java 5+ “.class” files.
  • A nice GUI:

screenshot

It works with compilers from JDK 1.1.8 up to JDK 1.7.0, and others (Jikes, JRockit, etc.).

It features an online live demo version that is actually fully functional! You can just drop a jar file on the page and see the decompiled source code without installing anything.

SQL Server - Create a copy of a database table and place it in the same database?

Use SELECT ... INTO:

SELECT *
INTO ABC_1
FROM ABC;

This will create a new table ABC_1 that has the same column structure as ABC and contains the same data. Constraints (e.g. keys, default values), however, are -not- copied.

You can run this query multiple times with a different table name each time.


If you don't need to copy the data, only to create a new empty table with the same column structure, add a WHERE clause with a falsy expression:

SELECT *
INTO ABC_1
FROM ABC
WHERE 1 <> 1;

How to programmatically move, copy and delete files and directories on SD?

Xamarin Android

public static bool MoveFile(string CurrentFilePath, string NewFilePath)
{
    try
    {
        using (var f = new File(CurrentFilePath))
        using (var i = new FileInputStream(f))
        using (var o = new FileOutputStream(NewFilePath))
        {
            i.Channel.TransferTo(0, i.Channel.Size(), o.Channel);
            f.Delete();
        }

        return true;
    }
    catch { return false; }
}

public static bool CopyFile(string CurrentFilePath, string NewFilePath)
{
    try
    {
        using (var i = new FileInputStream(CurrentFilePath))
        using (var o = new FileOutputStream(NewFilePath))
            i.Channel.TransferTo(0, i.Channel.Size(), o.Channel);

        return true;
    }
    catch { return false; }
}

public static bool DeleteFile(string FilePath)
{
    try
    {
        using (var file = new File(FilePath))
            file.Delete();

        return true;
    }
    catch { return false; }
}

Angularjs ng-model doesn't work inside ng-if

We had this in many other cases, what we decided internally is to always have a wrapper for the controller/directive so that we don't need to think about it. Here is you example with our wrapper.

<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.2.0rc1/angular.min.js"></script>

<script>
    function main($scope) {
        $scope.thisScope = $scope;
        $scope.testa = false;
        $scope.testb = false;
        $scope.testc = false;
        $scope.testd = false;
    }
</script>

<div ng-app >
    <div ng-controller="main">

        Test A: {{testa}}<br />
        Test B: {{testb}}<br />
        Test C: {{testc}}<br />
        Test D: {{testd}}<br />

        <div>
            testa (without ng-if): <input type="checkbox" ng-model="thisScope.testa" />
        </div>
        <div ng-if="!testa">
            testb (with ng-if): <input type="checkbox" ng-model="thisScope.testb" />
        </div>
        <div ng-show="!testa">
            testc (with ng-show): <input type="checkbox" ng-model="thisScope.testc" />
        </div>
        <div ng-hide="testa">
            testd (with ng-hide): <input type="checkbox" ng-model="thisScope.testd" />
        </div>

    </div>
</div>

Hopes this helps, Yishay

Error in Swift class: Property not initialized at super.init call

Add nil to the end of the declaration.


// Must be nil or swift complains
var someProtocol:SomeProtocol? = nil

// Init the view
override init(frame: CGRect)
    super.init(frame: frame)
    ...

This worked for my case, but may not work for yours

WPF chart controls

Try GraphIT from TechNewLogic, you can find it on CodePlex here: http://graphit.codeplex.com

Full Disclosure: I am the developer of GraphIT and owner of the developing company.

API Gateway CORS: no 'Access-Control-Allow-Origin' header

If you have tried everything regarding this issue to no avail, you'll end up where I did. It turns out, Amazon's existing CORS setup directions work just fine... just make sure you remember to redeploy! The CORS editing wizard, even with all its nice little green checkmarks, does not make live updates to your API. Perhaps obvious, but it stumped me for half a day.

enter image description here

Some projects cannot be imported because they already exist in the workspace error in Eclipse

delete it from eclipse......u might have closed the project in eclipse by "(Rightclick)-->close project".....so even if you delete this project from workspace folder....it stays there in eclipse IDE as closed project.....you should delete it from Eclipse IDE...!!!

Servlet for serving static content

try this

<servlet-mapping>
    <servlet-name>default</servlet-name>
    <url-pattern>*.js</url-pattern>
    <url-pattern>*.css</url-pattern>
    <url-pattern>*.ico</url-pattern>
    <url-pattern>*.png</url-pattern>
    <url-pattern>*.jpg</url-pattern>
    <url-pattern>*.htc</url-pattern>
    <url-pattern>*.gif</url-pattern>
</servlet-mapping>    

Edit: This is only valid for the servlet 2.5 spec and up.

How can I run Android emulator for Intel x86 Atom without hardware acceleration on Windows 8 for API 21 and 19?

The usage of the Hardware acceleration depends on the System Image you choose on the emulator.

So,

  1. Go to AVD manager, create virtual device, select hardware, click next.

  2. Choose the System Image that does not require HAXM (hardware acceleration) for running. (That is appears at the right bottom of System image window.)

Note: for other systems that require HAXM, there no way to run them without hardware acceleration.

Convert string to Color in C#

It depends on what you're looking for, if you need System.Windows.Media.Color (like in WPF) it's very easy:

System.Windows.Media.Color color = (Color)System.Windows.Media.ColorConverter.ConvertFromString("Red");//or hexadecimal color, e.g. #131A84

AngularJS - Value attribute on an input text box is ignored when there is a ng-model used?

This is a slight modification to the earlier answers...

There is no need for $parse

angular.directive('input', [function () {
  'use strict';

  var directiveDefinitionObject = {
    restrict: 'E',
    require: '?ngModel',
    link: function postLink(scope, iElement, iAttrs, ngModelController) {
      if (iAttrs.value && ngModelController) {
        ngModelController.$setViewValue(iAttrs.value);
      }
    }
  };

  return directiveDefinitionObject;
}]);

Populate data table from data reader

Please check the below code. Automatically it will convert as DataTable

private void ConvertDataReaderToTableManually()
    {
        SqlConnection conn = null;
        try
        {
            string connString = ConfigurationManager.ConnectionStrings["NorthwindConn"].ConnectionString;
            conn = new SqlConnection(connString);
            string query = "SELECT * FROM Customers";
            SqlCommand cmd = new SqlCommand(query, conn);
            conn.Open();
            SqlDataReader dr = cmd.ExecuteReader(CommandBehavior.CloseConnection);
            DataTable dtSchema = dr.GetSchemaTable();
            DataTable dt = new DataTable();
            // You can also use an ArrayList instead of List<>
            List<DataColumn> listCols = new List<DataColumn>();

            if (dtSchema != null)
            {
                foreach (DataRow drow in dtSchema.Rows)
                {
                    string columnName = System.Convert.ToString(drow["ColumnName"]);
                    DataColumn column = new DataColumn(columnName, (Type)(drow["DataType"]));
                    column.Unique = (bool)drow["IsUnique"];
                    column.AllowDBNull = (bool)drow["AllowDBNull"];
                    column.AutoIncrement = (bool)drow["IsAutoIncrement"];
                    listCols.Add(column);
                    dt.Columns.Add(column);
                }
            }

            // Read rows from DataReader and populate the DataTable
            while (dr.Read())
            {
                DataRow dataRow = dt.NewRow();
                for (int i = 0; i < listCols.Count; i++)
                {
                    dataRow[((DataColumn)listCols[i])] = dr[i];
                }
                dt.Rows.Add(dataRow);
            }
            GridView2.DataSource = dt;
            GridView2.DataBind();
        }
        catch (SqlException ex)
        {
            // handle error
        }
        catch (Exception ex)
        {
            // handle error
        }
        finally
        {
            conn.Close();
        }

    }

Implicit type conversion rules in C++ operators

Caveat!

The conversions occur from left to right.

Try this:

int i = 3, j = 2;
double k = 33;
cout << k * j / i << endl; // prints 22
cout << j / i * k << endl; // prints 0

Why is Tkinter Entry's get function returning nothing?

It looks like you may be confused as to when commands are run. In your example, you are calling the get method before the GUI has a chance to be displayed on the screen (which happens after you call mainloop.

Try adding a button that calls the get method. This is much easier if you write your application as a class. For example:

import tkinter as tk

class SampleApp(tk.Tk):
    def __init__(self):
        tk.Tk.__init__(self)
        self.entry = tk.Entry(self)
        self.button = tk.Button(self, text="Get", command=self.on_button)
        self.button.pack()
        self.entry.pack()

    def on_button(self):
        print(self.entry.get())

app = SampleApp()
app.mainloop()

Run the program, type into the entry widget, then click on the button.

How do you get the selected value of a Spinner?

Spinner spinner=(Spinner) findViewById(R.id.spinnername);
String valueinString = spinner.getSelectedItem().toString();

In Case Spinner values are int the typecast it to int

int valueinInt=(int)(spinner.getSelectedItem());

How do I remove/delete a virtualenv?

deactivate is the command you are looking for. Like what has already been said, there is no command for deleting your virtual environment. Simply deactivate it!

WCF gives an unsecured or incorrectly secured fault error

Same this problem i am facing my client application is WinForms application C# 4.0

When i read the solution here, i checked Date & Time of client computer, but that was right and current time was showing, but still i was facing these problem.

After some work-around i found that wrong time zone has selected, i am in India and time zone was of Canada, the host server is located in Kuwait.

I found that system converts time to universal time.

When i changed the time zone to India's time zone, the problem was soled.

Issue with adding common code as git submodule: "already exists in the index"

if there exists a folder named x under git control, you want add a same name submodule , you should delete folder x and commit it first.

Updated by @ujjwal-singh:

Committing is not needed, staging suffices.. git add / git rm -r

Angular HttpClient "Http failure during parsing"

if you have options

return this.http.post(`${this.endpoint}/account/login`,payload, { ...options, responseType: 'text' })

Get Selected value from dropdown using JavaScript

Try

var e = document.getElementById("mySelect");
var selectedOp = e.options[e.selectedIndex].text;

Javascript date regex DD/MM/YYYY

If you are in Javascript already, couldn't you just use Date.Parse() to validate a date instead of using regEx.

RegEx for date is actually unwieldy and hard to get right especially with leap years and all.

Excel VBA code to copy a specific string to clipboard

The simplest (Non Win32) way is to add a UserForm to your VBA project (if you don't already have one) or alternatively add a reference to Microsoft Forms 2 Object Library, then from a sheet/module you can simply:

With New MSForms.DataObject
    .SetText "http://zombo.com"
    .PutInClipboard
End With

Return HTML content as a string, given URL. Javascript Function

you need to return when the readystate==4 e.g.

function httpGet(theUrl)
{
    if (window.XMLHttpRequest)
    {// code for IE7+, Firefox, Chrome, Opera, Safari
        xmlhttp=new XMLHttpRequest();
    }
    else
    {// code for IE6, IE5
        xmlhttp=new ActiveXObject("Microsoft.XMLHTTP");
    }
    xmlhttp.onreadystatechange=function()
    {
        if (xmlhttp.readyState==4 && xmlhttp.status==200)
        {
            return xmlhttp.responseText;
        }
    }
    xmlhttp.open("GET", theUrl, false );
    xmlhttp.send();    
}

Getting full-size profile picture

With Javascript you can get full size profile images like this

pass your accessToken to the getface() function from your FB.init call

function getface(accessToken){
  FB.api('/me/friends', function (response) {
    for (id in response.data) { 
        var homie=response.data[id].id         
        FB.api(homie+'/albums?access_token='+accessToken, function (aresponse) {
          for (album in aresponse.data) {
            if (aresponse.data[album].name == "Profile Pictures") {                      
              FB.api(aresponse.data[album].id + "/photos", function(aresponse) {
                console.log(aresponse.data[0].images[0].source); 
              });                  
            }
          }   
        });
    }
  });
}

connecting MySQL server to NetBeans

Fist of all make sure your SQL server is running. Actually I'm working on windows and I have installed a nice tool which is called MySQL workbench (you can find it here for almost any platform ).

you can see the server is running

Thus I just create a new database to test the connection, let's call it stackoverflow, with one table called user.

SET @OLD_UNIQUE_CHECKS=@@UNIQUE_CHECKS, UNIQUE_CHECKS=0;
SET @OLD_FOREIGN_KEY_CHECKS=@@FOREIGN_KEY_CHECKS, FOREIGN_KEY_CHECKS=0;
SET @OLD_SQL_MODE=@@SQL_MODE, SQL_MODE='TRADITIONAL,ALLOW_INVALID_DATES';

DROP SCHEMA IF EXISTS `stackoverflow` ;
CREATE SCHEMA IF NOT EXISTS `stackoverflow` DEFAULT CHARACTER SET utf8 COLLATE utf8_general_ci ;
USE `stackoverflow` ;

-- -----------------------------------------------------
-- Table `stackoverflow`.`user`
-- -----------------------------------------------------
DROP TABLE IF EXISTS `stackoverflow`.`user` ;

CREATE TABLE IF NOT EXISTS `stackoverflow`.`user` (
  `iduser` INT NOT NULL AUTO_INCREMENT,
  `name` VARCHAR(75) NOT NULL,
  `email` VARCHAR(150) NOT NULL,
  PRIMARY KEY (`iduser`),
  UNIQUE INDEX `iduser_UNIQUE` (`iduser` ASC),
  UNIQUE INDEX `email_UNIQUE` (`email` ASC))
ENGINE = InnoDB;


SET SQL_MODE=@OLD_SQL_MODE;
SET FOREIGN_KEY_CHECKS=@OLD_FOREIGN_KEY_CHECKS;
SET UNIQUE_CHECKS=@OLD_UNIQUE_CHECKS;

You can reduce important part to

 CREATE SCHEMA IF NOT EXISTS `stackoverflow`

 CREATE TABLE IF NOT EXISTS `stackoverflow`.`user` (
      `iduser` INT NOT NULL AUTO_INCREMENT,
      `name` VARCHAR(75) NOT NULL,
      `email` VARCHAR(150) NOT NULL,
      PRIMARY KEY (`iduser`),
      UNIQUE INDEX `iduser_UNIQUE` (`iduser` ASC),
      UNIQUE INDEX `email_UNIQUE` (`email` ASC))

So now I have my brand new stackoverflow database. Let's connect to it throught Netbeans. Launch netbeans and go to the services panel list of connections available Now right click on databases: new connection.. Choose MySql connector, they already come packed with netbeans. connector Then fill in the gaps the data you need. As shown in the picture add the database name and remove from the connection url the optional parameters as l?zeroDateTimeBehaviour=convertToNull . Use the right user name and password and test the connection. data

As you can see connection is successful.

Click FINISH.

You will have your connection successfully working and available under the services.

finish

Why is "throws Exception" necessary when calling a function?

Exception is a checked exception class. Therefore, any code that calls a method that declares that it throws Exception must handle or declare it.

Using RegEX To Prefix And Append In Notepad++

Assuming alphanumeric words, you can use:

Search  = ^([A-Za-z0-9]+)$
Replace = able:"\1"

Or, if you just want to highlight the lines and use "Replace All" & "In Selection" (with the same replace):

Search = ^(.+)$

^ points to the start of the line.
$ points to the end of the line.

\1 will be the source match within the parentheses.

How to load property file from classpath?

If you use the static method and load the properties file from the classpath folder so you can use the below code :

//load a properties file from class path, inside static method
Properties prop = new Properties();
prop.load(Classname.class.getClassLoader().getResourceAsStream("foo.properties"));

Error: Cannot find module '../lib/utils/unsupported.js' while using Ionic

Try to remove /usr/local/lib/node_modules/npm and reinstall node again. This should work.

On MacOS with Homebrew:

sudo rm -rf /usr/local/lib/node_modules/npm
brew reinstall node

How do I import an SQL file using the command line in MySQL?

Providing credentials on the command line is not a good idea. The above answers are great, but neglect to mention

mysql --defaults-extra-file=etc/myhost.cnf database_name < file.sql

Where etc/myhost.cnf is a file that contains host, user, password, and you avoid exposing the password on the command line. Here is a sample,

[client]
host=hostname.domainname
user=dbusername
password=dbpassword

Select first row in each GROUP BY group?

Use ARRAY_AGG function for PostgreSQL, U-SQL, IBM DB2, and Google BigQuery SQL:

SELECT customer, (ARRAY_AGG(id ORDER BY total DESC))[1], MAX(total)
FROM purchases
GROUP BY customer

java.net.SocketTimeoutException: Read timed out under Tomcat

Here are the basic instructions:-

  1. Locate the "server.xml" file in the "conf" folder beneath Tomcat's base directory (i.e. %CATALINA_HOME%/conf/server.xml).
  2. Open the file in an editor and search for <Connector.
  3. Locate the relevant connector that is timing out - this will typically be the HTTP connector, i.e. the one with protocol="HTTP/1.1".
  4. If a connectionTimeout value is set on the connector, it may need to be increased - e.g. from 20000 milliseconds (= 20 seconds) to 120000 milliseconds (= 2 minutes). If no connectionTimeout property value is set on the connector, the default is 60 seconds - if this is insufficient, the property may need to be added.
  5. Restart Tomcat

How do I set a JLabel's background color?

You must set the setOpaque(true) to true other wise the background will not be painted to the form. I think from reading that if it is not set to true that it will paint some or not any of its pixels to the form. The background is transparent by default which seems odd to me at least but in the way of programming you have to set it to true as shown below.

      JLabel lb = new JLabel("Test");
      lb.setBackground(Color.red);
      lb.setOpaque(true); <--This line of code must be set to true or otherwise the 

From the JavaDocs

setOpaque

public void setOpaque(boolean isOpaque)
  If true the component paints every pixel within its bounds. Otherwise, 
  the component may not paint some or all of its pixels, allowing the underlying 
  pixels to show through.
  The default value of this property is false for JComponent. However, 
  the default value for this property on most standard JComponent subclasses 
   (such as JButton and JTree) is look-and-feel dependent.

Parameters:
isOpaque - true if this component should be opaque
See Also:
isOpaque()

What version of MongoDB is installed on Ubuntu

inside shell:

mongod --version

How do the major C# DI/IoC frameworks compare?

Just read this great .Net DI container comparison blog by Philip Mat.

He does some thorough performance comparison tests on;

He recommends Autofac as it is small, fast, and easy to use ... I agree. It appears that Unity and Ninject are the slowest in his tests.

"RangeError: Maximum call stack size exceeded" Why?

Here it fails at Array.apply(null, new Array(1000000)) and not the .map call.

All functions arguments must fit on callstack(at least pointers of each argument), so in this they are too many arguments for the callstack.

You need to the understand what is call stack.

Stack is a LIFO data structure, which is like an array that only supports push and pop methods.

Let me explain how it works by a simple example:

function a(var1, var2) {
    var3 = 3;
    b(5, 6);
    c(var1, var2);
}
function b(var5, var6) {
    c(7, 8);
}
function c(var7, var8) {
}

When here function a is called, it will call b and c. When b and c are called, the local variables of a are not accessible there because of scoping roles of Javascript, but the Javascript engine must remember the local variables and arguments, so it will push them into the callstack. Let's say you are implementing a JavaScript engine with the Javascript language like Narcissus.

We implement the callStack as array:

var callStack = [];

Everytime a function called we push the local variables into the stack:

callStack.push(currentLocalVaraibles);

Once the function call is finished(like in a, we have called b, b is finished executing and we must return to a), we get back the local variables by poping the stack:

currentLocalVaraibles = callStack.pop();

So when in a we want to call c again, push the local variables in the stack. Now as you know, compilers to be efficient define some limits. Here when you are doing Array.apply(null, new Array(1000000)), your currentLocalVariables object will be huge because it will have 1000000 variables inside. Since .apply will pass each of the given array element as an argument to the function. Once pushed to the call stack this will exceed the memory limit of call stack and it will throw that error.

Same error happens on infinite recursion(function a() { a() }) as too many times, stuff has been pushed to the call stack.

Note that I'm not a compiler engineer and this is just a simplified representation of what's going on. It really is more complex than this. Generally what is pushed to callstack is called stack frame which contains the arguments, local variables and the function address.

Determine path of the executing script

I like this approach:

this.file <- sys.frame(tail(grep('source',sys.calls()),n=1))$ofile
this.dir <- dirname(this.file)

How to make a TextBox accept only alphabetic characters?

you can try following code that alert at the time of key press event

private void tbOwnerName_KeyPress(object sender, KeyPressEventArgs e)
    {

        //===================to accept only charactrs & space/backspace=============================================

        if (e.Handled = !(char.IsLetter(e.KeyChar) || e.KeyChar == (char)Keys.Back || e.KeyChar == (char)Keys.Space))
        {
            e.Handled = true;
            base.OnKeyPress(e);
            MessageBox.Show("enter characters only");
        }

What is the parameter "next" used for in Express?

I also had problem understanding next() , but this helped

var app = require("express")();

app.get("/", function(httpRequest, httpResponse, next){
    httpResponse.write("Hello");
    next(); //remove this and see what happens 
});

app.get("/", function(httpRequest, httpResponse, next){
    httpResponse.write(" World !!!");
    httpResponse.end();
});

app.listen(8080);

How to execute a remote command over ssh with arguments?

This is an example that works on the AWS Cloud. The scenario is that some machine that booted from autoscaling needs to perform some action on another server, passing the newly spawned instance DNS via SSH

# Get the public DNS of the current machine (AWS specific)
MY_DNS=`curl -s http://169.254.169.254/latest/meta-data/public-hostname`


ssh \
    -o StrictHostKeyChecking=no \
    -i ~/.ssh/id_rsa \
    [email protected] \
<< EOF
cd ~/
echo "Hey I was just SSHed by ${MY_DNS}"
run_other_commands
# Newline is important before final EOF!

EOF

What is a database transaction?

http://en.wikipedia.org/wiki/Database_transaction
http://en.wikipedia.org/wiki/ACID
ACID = Atomicity, Consistency, Isolation, Durability

When you wish for multiple transactional resources to be involved in a single transaction, you will need to use something like a two-phase commit solution. XA is quite widely supported.

HTML if image is not found

Ok but I like to use this way, so that whenever original image is not available you can load your default image that may be your favorite smiley or image saying Sorry ! Not Available, But in case if both the images are missing you can use text to display. where you can also you smiley then. have a look almost covers every case.

<img src="path_to_original_img/img.png"  alt="Sorry! Image not available at this time" 
       onError="this.onerror=null;this.src='<?=base_url()?>assets1/img/default.jpg';">

How to set focus on input field?

Probably, the simplest solution on the ES6 age.

Adding following one liner directive makes HTML 'autofocus' attribute effective on Angular.js.

.directive('autofocus', ($timeout) => ({link: (_, e) => $timeout(() => e[0].focus())}))

Now, you can just use HTML5 autofocus syntax like:

<input type="text" autofocus>

Convert a string date into datetime in Oracle

You can use a cast to char to see the date results

_x000D_
_x000D_
 select to_char(to_date('17-MAR-17 06.04.54','dd-MON-yy hh24:mi:ss'), 'mm/dd/yyyy hh24:mi:ss') from dual;
_x000D_
_x000D_
_x000D_

AngularJS - Building a dynamic table based on a json

Just want to share with what I used so far to save your time.

Here are examples of hard-coded headers and dynamic headers (in case if don't care about data structure). In both cases I wrote some simple directive: customSort

customSort

.directive("customSort", function() {
    return {
        restrict: 'A',
        transclude: true,    
        scope: {
          order: '=',
          sort: '='
        },
        template : 
          ' <a ng-click="sort_by(order)" style="color: #555555;">'+
          '    <span ng-transclude></span>'+
          '    <i ng-class="selectedCls(order)"></i>'+
          '</a>',
        link: function(scope) {

        // change sorting order
        scope.sort_by = function(newSortingOrder) {       
            var sort = scope.sort;

            if (sort.sortingOrder == newSortingOrder){
                sort.reverse = !sort.reverse;
            }                    

            sort.sortingOrder = newSortingOrder;        
        };


        scope.selectedCls = function(column) {
            if(column == scope.sort.sortingOrder){
                return ('icon-chevron-' + ((scope.sort.reverse) ? 'down' : 'up'));
            }
            else{            
                return'icon-sort' 
            } 
        };      
      }// end link
    }
    });

[1st option with static headers]

I used single ng-repeat

This is a good example in Fiddle (Notice, there is no jQuery library!)

enter image description here

           <tbody>
                <tr ng-repeat="item in pagedItems[currentPage] | orderBy:sortingOrder:reverse">
                    <td>{{item.id}}</td>
                    <td>{{item.name}}</td>
                    <td>{{item.description}}</td>
                    <td>{{item.field3}}</td>
                    <td>{{item.field4}}</td>
                    <td>{{item.field5}}</td>
                </tr>
            </tbody>

[2nd option with dynamic headers]

Demo 2: Fiddle


HTML

<table class="table table-striped table-condensed table-hover">
            <thead>
                <tr>
                   <th ng-repeat="header in table_headers"  
                     class="{{header.name}}" custom-sort order="header.name" sort="sort"
                    >{{ header.name }}

                        </th> 
                  </tr>
            </thead>
            <tfoot>
                <td colspan="6">
                    <div class="pagination pull-right">
                        <ul>
                            <li ng-class="{disabled: currentPage == 0}">
                                <a href ng-click="prevPage()">« Prev</a>
                            </li>

                            <li ng-repeat="n in range(pagedItems.length, currentPage, currentPage + gap) "
                                ng-class="{active: n == currentPage}"
                            ng-click="setPage()">
                                <a href ng-bind="n + 1">1</a>
                            </li>

                            <li ng-class="{disabled: (currentPage) == pagedItems.length - 1}">
                                <a href ng-click="nextPage()">Next »</a>
                            </li>
                        </ul>
                    </div>
                </td>
            </tfoot>
            <pre>pagedItems.length: {{pagedItems.length|json}}</pre>
            <pre>currentPage: {{currentPage|json}}</pre>
            <pre>currentPage: {{sort|json}}</pre>
            <tbody>

                <tr ng-repeat="item in pagedItems[currentPage] | orderBy:sort.sortingOrder:sort.reverse">
                     <td ng-repeat="val in item" ng-bind-html-unsafe="item[table_headers[$index].name]"></td>
                </tr>
            </tbody>
        </table>

As a side note:

The ng-bind-html-unsafe is deprecated, so I used it only for Demo (2nd example). You welcome to edit.

Can I set up HTML/Email Templates with ASP.NET?

Just throwing the library I'm using into the mix: https://github.com/lukencode/FluentEmail

It renders emails using RazorLight, uses the fluent style to build emails, and supports multiple senders out of the box. It comes with extension methods for ASP.NET DI too. Simple to use, little setup, with plain text and HTML support.

How to get a Static property with Reflection

A little clarity...

// Get a PropertyInfo of specific property type(T).GetProperty(....)
PropertyInfo propertyInfo;
propertyInfo = typeof(TypeWithTheStaticProperty)
    .GetProperty("NameOfStaticProperty", BindingFlags.Public | BindingFlags.Static); 

// Use the PropertyInfo to retrieve the value from the type by not passing in an instance
object value = propertyInfo.GetValue(null, null);

// Cast the value to the desired type
ExpectedType typedValue = (ExpectedType) value;

C# : Passing a Generic Object

You cannot access var with the generic.

Try something like

Console.WriteLine("Generic : {0}", test);

And override ToString method [1]

[1] http://msdn.microsoft.com/en-us/library/system.object.tostring.aspx

How to install MySQLdb package? (ImportError: No module named setuptools)

I resolved this issue on centos5.4 by running the following command to install setuptools

yum install python-setuptools

I hope that helps.

What is the meaning of CTOR?

Type "ctor" and press the TAB key twice this will add the default constructor automatically

Should I use scipy.pi, numpy.pi, or math.pi?

>>> import math
>>> import numpy as np
>>> import scipy
>>> math.pi == np.pi == scipy.pi
True

So it doesn't matter, they are all the same value.

The only reason all three modules provide a pi value is so if you are using just one of the three modules, you can conveniently have access to pi without having to import another module. They're not providing different values for pi.

Print the contents of a DIV

function printdiv(printdivname) {
    var headstr = "<html><head><title>Booking Details</title></head><body>";
    var footstr = "</body>";
    var newstr = document.getElementById(printdivname).innerHTML;
    var oldstr = document.body.innerHTML;
    document.body.innerHTML = headstr+newstr+footstr;
    window.print();
    document.body.innerHTML = oldstr;
    return false;
}

This will print the div area you want and set the content back to as it was. printdivname is the div to be printed.

Center image horizontally within a div

<!DOCTYPE html>
<html>
    <head>
        <meta charset="utf-8">
        <meta name="viewport" content="width=device-width, initial-scale=1">


      <style>
      body{
  /*-------------------important for fluid images---\/--*/
  overflow-x: hidden; /* some browsers shows it for mysterious reasons to me*/
  overflow-y: scroll;
  margin-left:0px;
  margin-top:0px;
  /*-------------------important for fluid images---/\--*/
      }
      .thirddiv{
      float:left;
      width:100vw;
      height:100vh;
      margin:0px;
      background:olive;
      }
      .thirdclassclassone{
      float:left;   /*important*/
      background:grey;
      width:80vw;
      height:80vh; /*match with img height bellow*/
      margin-left:10vw; /* 100vw minus "width"/2    */
      margin-right:10vw; /* 100vw minus "width"/2   */
      margin-top:10vh;
      }
      .thirdclassclassone img{
      position:relative; /*important*/
     display: block;  /*important*/
    margin-left: auto;  /*very important*/
    margin-right: auto;  /*very important*/
    height:80vh; /*match with parent div above*/

    /*--------------------------------
    margin-top:5vh;
    margin-bottom:5vh;
    ---------------------------------*/
    /*---------------------set margins to match total  height of parent di----------------------------------------*/
      }
    </style>           
</head>  
<body>
    <div class="thirddiv">
       <div class="thirdclassclassone">
       <img src="ireland.png">
    </div>      
</body>
</html>

implement time delay in c

If you are certain you want to wait and never get interrupted then use sleep in POSIX or Sleep in Windows. In POSIX sleep takes time in seconds so if you want the time to be shorter there are varieties like usleep() which uses microseconds. Sleep in Windows takes milliseconds, it is rare you need finer granularity than that.

It may be that you wish to wait a period of time but want to allow interrupts, maybe in the case of an emergency. sleep can be interrupted by signals but there is a better way of doing it in this case.

Therefore I actually found in practice what you do is wait for an event or a condition variable with a timeout.

In Windows your call is WaitForSingleObject. In POSIX it is pthread_cond_timedwait.

In Windows you can also use WaitForSingleObjectEx and then you can actually "interrupt" your thread with any queued task by calling QueueUserAPC. WaitForSingleObject(Ex) will return a code determining why it exited, so you will know when it returns a "TIMEDOUT" status that it did indeed timeout. You set the Event it is waiting for when you want it to terminate.

With pthread_cond_timedwait you can signal broadcast the condition variable. (If several threads are waiting on the same one, you will need to broadcast to wake them all up). Each time it loops it should check the condition. Your thread can get the current time and see if it has passed or it can look to see if some condition has been met to determine what to do. If you have some kind of queue you can check it. (Your thread will automatically have a mutex locked that it used to wait on the condition variable, so when it checks the condition it has sole access to it).

Count a list of cells with the same background color

I just created this and it looks easier. You get these 2 functions:

=GetColorIndex(E5)  <- returns color number for the cell

from (cell)

=CountColorIndexInRange(C7:C24,14) <- returns count of cells C7:C24 with color 14

from (range of cells, color number you want to count)

example shows percent of cells with color 14

=ROUND(CountColorIndexInRange(C7:C24,14)/18, 4 )

Create these 2 VBA functions in a Module (hit Alt-F11)

open + folders. double-click on Module1

Just paste this text below in, then close the module window (it must save it then):

Function GetColorIndex(Cell As Range)
  GetColorIndex = Cell.Interior.ColorIndex
End Function

Function CountColorIndexInRange(Rng As Range, TestColor As Long)
  Dim cnt
  Dim cl As Range
  cnt = 0

  For Each cl In Rng
    If GetColorIndex(cl) = TestColor Then
      Rem Debug.Print ">" & TestColor & "<"
      cnt = cnt + 1
    End If
  Next

  CountColorIndexInRange = cnt

End Function

How to change the background color on a input checkbox with css?

I always use pseudo elements :before and :after for changing the appearance of checkboxes and radio buttons. it's works like a charm.

Refer this link for more info

CODEPEN

Steps

  1. Hide the default checkbox using css rules like visibility:hidden or opacity:0 or position:absolute;left:-9999px etc.
  2. Create a fake checkbox using :before element and pass either an empty or a non-breaking space '\00a0';
  3. When the checkbox is in :checked state, pass the unicode content: "\2713", which is a checkmark;
  4. Add :focus style to make the checkbox accessible.
  5. Done

Here is how I did it.

_x000D_
_x000D_
.box {_x000D_
  background: #666666;_x000D_
  color: #ffffff;_x000D_
  width: 250px;_x000D_
  padding: 10px;_x000D_
  margin: 1em auto;_x000D_
}_x000D_
p {_x000D_
  margin: 1.5em 0;_x000D_
  padding: 0;_x000D_
}_x000D_
input[type="checkbox"] {_x000D_
  visibility: hidden;_x000D_
}_x000D_
label {_x000D_
  cursor: pointer;_x000D_
}_x000D_
input[type="checkbox"] + label:before {_x000D_
  border: 1px solid #333;_x000D_
  content: "\00a0";_x000D_
  display: inline-block;_x000D_
  font: 16px/1em sans-serif;_x000D_
  height: 16px;_x000D_
  margin: 0 .25em 0 0;_x000D_
  padding: 0;_x000D_
  vertical-align: top;_x000D_
  width: 16px;_x000D_
}_x000D_
input[type="checkbox"]:checked + label:before {_x000D_
  background: #fff;_x000D_
  color: #333;_x000D_
  content: "\2713";_x000D_
  text-align: center;_x000D_
}_x000D_
input[type="checkbox"]:checked + label:after {_x000D_
  font-weight: bold;_x000D_
}_x000D_
_x000D_
input[type="checkbox"]:focus + label::before {_x000D_
    outline: rgb(59, 153, 252) auto 5px;_x000D_
}
_x000D_
<div class="content">_x000D_
  <div class="box">_x000D_
    <p>_x000D_
      <input type="checkbox" id="c1" name="cb">_x000D_
      <label for="c1">Option 01</label>_x000D_
    </p>_x000D_
    <p>_x000D_
      <input type="checkbox" id="c2" name="cb">_x000D_
      <label for="c2">Option 02</label>_x000D_
    </p>_x000D_
    <p>_x000D_
      <input type="checkbox" id="c3" name="cb">_x000D_
      <label for="c3">Option 03</label>_x000D_
    </p>_x000D_
  </div>_x000D_
</div>
_x000D_
_x000D_
_x000D_

Much more stylish using :before and :after

_x000D_
_x000D_
body{_x000D_
  font-family: sans-serif;  _x000D_
}_x000D_
_x000D_
.container {_x000D_
    margin-top: 50px;_x000D_
    margin-left: 20px;_x000D_
    margin-right: 20px;_x000D_
}_x000D_
.checkbox {_x000D_
    width: 100%;_x000D_
    margin: 15px auto;_x000D_
    position: relative;_x000D_
    display: block;_x000D_
}_x000D_
_x000D_
.checkbox input[type="checkbox"] {_x000D_
    width: auto;_x000D_
    opacity: 0.00000001;_x000D_
    position: absolute;_x000D_
    left: 0;_x000D_
    margin-left: -20px;_x000D_
}_x000D_
.checkbox label {_x000D_
    position: relative;_x000D_
}_x000D_
.checkbox label:before {_x000D_
    content: '';_x000D_
    position: absolute;_x000D_
    left: 0;_x000D_
    top: 0;_x000D_
    margin: 4px;_x000D_
    width: 22px;_x000D_
    height: 22px;_x000D_
    transition: transform 0.28s ease;_x000D_
    border-radius: 3px;_x000D_
    border: 2px solid #7bbe72;_x000D_
}_x000D_
.checkbox label:after {_x000D_
  content: '';_x000D_
    display: block;_x000D_
    width: 10px;_x000D_
    height: 5px;_x000D_
    border-bottom: 2px solid #7bbe72;_x000D_
    border-left: 2px solid #7bbe72;_x000D_
    -webkit-transform: rotate(-45deg) scale(0);_x000D_
    transform: rotate(-45deg) scale(0);_x000D_
    transition: transform ease 0.25s;_x000D_
    will-change: transform;_x000D_
    position: absolute;_x000D_
    top: 12px;_x000D_
    left: 10px;_x000D_
}_x000D_
.checkbox input[type="checkbox"]:checked ~ label::before {_x000D_
    color: #7bbe72;_x000D_
}_x000D_
_x000D_
.checkbox input[type="checkbox"]:checked ~ label::after {_x000D_
    -webkit-transform: rotate(-45deg) scale(1);_x000D_
    transform: rotate(-45deg) scale(1);_x000D_
}_x000D_
_x000D_
.checkbox label {_x000D_
    min-height: 34px;_x000D_
    display: block;_x000D_
    padding-left: 40px;_x000D_
    margin-bottom: 0;_x000D_
    font-weight: normal;_x000D_
    cursor: pointer;_x000D_
    vertical-align: sub;_x000D_
}_x000D_
.checkbox label span {_x000D_
    position: absolute;_x000D_
    top: 50%;_x000D_
    -webkit-transform: translateY(-50%);_x000D_
    transform: translateY(-50%);_x000D_
}_x000D_
.checkbox input[type="checkbox"]:focus + label::before {_x000D_
    outline: 0;_x000D_
}
_x000D_
<div class="container"> _x000D_
  <div class="checkbox">_x000D_
     <input type="checkbox" id="checkbox" name="" value="">_x000D_
     <label for="checkbox"><span>Checkbox</span></label>_x000D_
  </div>_x000D_
_x000D_
  <div class="checkbox">_x000D_
     <input type="checkbox" id="checkbox2" name="" value="">_x000D_
     <label for="checkbox2"><span>Checkbox</span></label>_x000D_
  </div>_x000D_
</div>
_x000D_
_x000D_
_x000D_

Where's javax.servlet?

Have you instaled the J2EE? If you installed just de standard (J2SE) it won´t find.

How can I extract substrings from a string in Perl?

(\S*)\s*\((.*?)\)\s*(\*?)


(\S*)    picks up anything which is NOT whitespace
\s*      0 or more whitespace characters
\(       a literal open parenthesis
(.*?)    anything, non-greedy so stops on first occurrence of...
\)       a literal close parenthesis
\s*      0 or more whitespace characters
(\*?)    0 or 1 occurances of literal *

Getting current date and time in JavaScript

Basic JS (good to learn): we use the Date() function and do all that we need to show the date and day in our custom format.

_x000D_
_x000D_
var myDate = new Date();_x000D_
_x000D_
let daysList = ['Sunday', 'Monday', 'Tuesday', 'Wednesday', 'Thursday', 'Friday', 'Saturday'];_x000D_
let monthsList = ['Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun', 'Jul', 'Aug', 'Sep', 'Aug', 'Oct', 'Nov', 'Dec'];_x000D_
_x000D_
_x000D_
let date = myDate.getDate();_x000D_
let month = monthsList[myDate.getMonth()];_x000D_
let year = myDate.getFullYear();_x000D_
let day = daysList[myDate.getDay()];_x000D_
_x000D_
let today = `${date} ${month} ${year}, ${day}`;_x000D_
_x000D_
let amOrPm;_x000D_
let twelveHours = function (){_x000D_
    if(myDate.getHours() > 12)_x000D_
    {_x000D_
        amOrPm = 'PM';_x000D_
        let twentyFourHourTime = myDate.getHours();_x000D_
        let conversion = twentyFourHourTime - 12;_x000D_
        return `${conversion}`_x000D_
_x000D_
    }else {_x000D_
        amOrPm = 'AM';_x000D_
        return `${myDate.getHours()}`}_x000D_
};_x000D_
let hours = twelveHours();_x000D_
let minutes = myDate.getMinutes();_x000D_
_x000D_
let currentTime = `${hours}:${minutes} ${amOrPm}`;_x000D_
_x000D_
console.log(today + ' ' + currentTime);
_x000D_
_x000D_
_x000D_


Node JS (quick & easy): Install the npm pagckage using (npm install date-and-time), then run the below.

let nodeDate = require('date-and-time');
let now = nodeDate.format(new Date(), 'DD-MMMM-YYYY, hh:mm:ss a');
console.log(now);

How do I resolve "Please make sure that the file is accessible and that it is a valid assembly or COM component"?

I had the same program, I hope this could help.

I your using Windows 7, open Command Prompt-> run as Administrator. register your <...>.dll.

Why run as Administrator, you can register your <...>.dll using the run at the Windows Start, but still your dll only run as user even your account is administrator.

Now you can add your <...>.dll at the Project->Add Reference->Browse

Thanks

pow (x,y) in Java

In Java x ^ y is an XOR operation.

What's the "Content-Length" field in HTTP header?

One octet is 8 bits. Content-length is the number of octets that the message body represents.

SQL Server - after insert trigger - update another column in the same table

Yes, it will recursively call your trigger unless you turn the recursive triggers setting off:

ALTER DATABASE db_name SET RECURSIVE_TRIGGERS OFF 

MSDN has a good explanation of the behavior at http://msdn.microsoft.com/en-us/library/aa258254(SQL.80).aspx under the Recursive Triggers heading.

Python: download a file from an FTP server

Try using the wget library for python. You can find the documentation for it here.

import wget
link = 'ftp://example.com/foo.txt'
wget.download(link)

Safest way to convert float to integer in python?

That this works is not trivial at all! It's a property of the IEEE floating point representation that int°floor = ?·? if the magnitude of the numbers in question is small enough, but different representations are possible where int(floor(2.3)) might be 1.

This post explains why it works in that range.

In a double, you can represent 32bit integers without any problems. There cannot be any rounding issues. More precisely, doubles can represent all integers between and including 253 and -253.

Short explanation: A double can store up to 53 binary digits. When you require more, the number is padded with zeroes on the right.

It follows that 53 ones is the largest number that can be stored without padding. Naturally, all (integer) numbers requiring less digits can be stored accurately.

Adding one to 111(omitted)111 (53 ones) yields 100...000, (53 zeroes). As we know, we can store 53 digits, that makes the rightmost zero padding.

This is where 253 comes from.


More detail: We need to consider how IEEE-754 floating point works.

  1 bit    11 / 8     52 / 23      # bits double/single precision
[ sign |  exponent | mantissa ]

The number is then calculated as follows (excluding special cases that are irrelevant here):

-1sign × 1.mantissa ×2exponent - bias

where bias = 2exponent - 1 - 1, i.e. 1023 and 127 for double/single precision respectively.

Knowing that multiplying by 2X simply shifts all bits X places to the left, it's easy to see that any integer must have all bits in the mantissa that end up right of the decimal point to zero.

Any integer except zero has the following form in binary:

1x...x where the x-es represent the bits to the right of the MSB (most significant bit).

Because we excluded zero, there will always be a MSB that is one—which is why it's not stored. To store the integer, we must bring it into the aforementioned form: -1sign × 1.mantissa ×2exponent - bias.

That's saying the same as shifting the bits over the decimal point until there's only the MSB towards the left of the MSB. All the bits right of the decimal point are then stored in the mantissa.

From this, we can see that we can store at most 52 binary digits apart from the MSB.

It follows that the highest number where all bits are explicitly stored is

111(omitted)111.   that's 53 ones (52 + implicit 1) in the case of doubles.

For this, we need to set the exponent, such that the decimal point will be shifted 52 places. If we were to increase the exponent by one, we cannot know the digit right to the left after the decimal point.

111(omitted)111x.

By convention, it's 0. Setting the entire mantissa to zero, we receive the following number:

100(omitted)00x. = 100(omitted)000.

That's a 1 followed by 53 zeroes, 52 stored and 1 added due to the exponent.

It represents 253, which marks the boundary (both negative and positive) between which we can accurately represent all integers. If we wanted to add one to 253, we would have to set the implicit zero (denoted by the x) to one, but that's impossible.

Using helpers in model: how do I include helper dependencies?

This gives you just the helper method without the side effects of loading every ActionView::Helpers method into your model:

ActionController::Base.helpers.sanitize(str)

How to uninstall a Windows Service when there is no executable for it left on the system?

You should be able to uninstall it using sc.exe (I think it is included in the Windows Resource Kit) by running the following in an "administrator" command prompt:

sc.exe delete <service name>

where <service name> is the name of the service itself as you see it in the service management console, not of the exe.

You can find sc.exe in the System folder and it needs Administrative privileges to run. More information in this Microsoft KB article.

Alternatively, you can directly call the DeleteService() api. That way is a little more complex, since you need to get a handle to the service control manager via OpenSCManager() and so on, but on the other hand it gives you more control over what is happening.

pthread_join() and pthread_exit()

It because every time

void pthread_exit(void *ret);

will be called from thread function so which ever you want to return simply its pointer pass with pthread_exit().

Now at

int pthread_join(pthread_t tid, void **ret);

will be always called from where thread is created so here to accept that returned pointer you need double pointer ..

i think this code will help you to understand this

#include <stdio.h>
#include <string.h>
#include <pthread.h>
#include <stdlib.h>

void* thread_function(void *ignoredInThisExample)
{
    char *a = malloc(10);
    strcpy(a,"hello world");
    pthread_exit((void*)a);
}
int main()
{
    pthread_t thread_id;
    char *b;

    pthread_create (&thread_id, NULL,&thread_function, NULL);

    pthread_join(thread_id,(void**)&b); //here we are reciving one pointer 
                                        value so to use that we need double pointer 
    printf("b is %s\n",b); 
    free(b); // lets free the memory

}

Import CSV to SQLite

With Termsql you can do it in one line:

termsql -i mycsvfile.CSV -d ',' -c 'a,b' -t 'foo' -o mynewdatabase.db

Run git pull over all subdirectories

If you have a lot of subdirs with git repositories, you can use parallel

ls | parallel -I{} -j100 '
  if [ -d {}/.git ]; then
    echo Pulling {}
    git -C {} pull > /dev/null && echo "pulled" || echo "error :("
  else
     echo {} is not a .git directory
  fi
'

Cannot connect to MySQL Workbench on mac. Can't connect to MySQL server on '127.0.0.1' (61) Mac Macintosh

Try restarting the mysql or starting it if it wasn't started already. Type this within terminal.

mysql.server restart

To auto start go to the following link below:

How to auto-load MySQL on startup on OS X Yosemite / El Capitan

How do I check to see if a value is an integer in MySQL?

I'll assume you want to check a string value. One nice way is the REGEXP operator, matching the string to a regular expression. Simply do

select field from table where field REGEXP '^-?[0-9]+$';

this is reasonably fast. If your field is numeric, just test for

ceil(field) = field

instead.

What is the difference between VFAT and FAT32 file systems?

Copied from http://technet.microsoft.com/en-us/library/cc750354.aspx

What's FAT?

FAT may sound like a strange name for a file system, but it's actually an acronym for File Allocation Table. Introduced in 1981, FAT is ancient in computer terms. Because of its age, most operating systems, including Microsoft Windows NT®, Windows 98, the Macintosh OS, and some versions of UNIX, offer support for FAT.

The FAT file system limits filenames to the 8.3 naming convention, meaning that a filename can have no more than eight characters before the period and no more than three after. Filenames in a FAT file system must also begin with a letter or number, and they can't contain spaces. Filenames aren't case sensitive.

What About VFAT?

Perhaps you've also heard of a file system called VFAT. VFAT is an extension of the FAT file system and was introduced with Windows 95. VFAT maintains backward compatibility with FAT but relaxes the rules. For example, VFAT filenames can contain up to 255 characters, spaces, and multiple periods. Although VFAT preserves the case of filenames, it's not considered case sensitive.

When you create a long filename (longer than 8.3) with VFAT, the file system actually creates two different filenames. One is the actual long filename. This name is visible to Windows 95, Windows 98, and Windows NT (4.0 and later). The second filename is called an MS-DOS® alias. An MS-DOS alias is an abbreviated form of the long filename. The file system creates the MS-DOS alias by taking the first six characters of the long filename (not counting spaces), followed by the tilde [~] and a numeric trailer. For example, the filename Brien's Document.txt would have an alias of BRIEN'~1.txt.

An interesting side effect results from the way VFAT stores its long filenames. When you create a long filename with VFAT, it uses one directory entry for the MS-DOS alias and another entry for every 13 characters of the long filename. In theory, a single long filename could occupy up to 21 directory entries. The root directory has a limit of 512 files, but if you were to use the maximum length long filenames in the root directory, you could cut this limit to a mere 24 files. Therefore, you should use long filenames very sparingly in the root directory. Other directories aren't affected by this limit.

You may be wondering why we're discussing VFAT. The reason is it's becoming more common than FAT, but aside from the differences I mentioned above, VFAT has the same limitations. When you tell Windows NT to format a partition as FAT, it actually formats the partition as VFAT. The only time you'll have a true FAT partition under Windows NT 4.0 is when you use another operating system, such as MS-DOS, to format the partition.

FAT32

FAT32 is actually an extension of FAT and VFAT, first introduced with Windows 95 OEM Service Release 2 (OSR2). FAT32 greatly enhances the VFAT file system but it does have its drawbacks.

The greatest advantage to FAT32 is that it dramatically increases the amount of free hard disk space. To illustrate this point, consider that a FAT partition (also known as a FAT16 partition) allows only a certain number of clusters per partition. Therefore, as your partition size increases, the cluster size must also increase. For example, a 512-MB FAT partition has a cluster size of 8K, while a 2-GB partition has a cluster size of 32K.

This may not sound like a big deal until you consider that the FAT file system only works in single cluster increments. For example, on a 2-GB partition, a 1-byte file will occupy the entire cluster, thereby consuming 32K, or roughly 32,000 times the amount of space that the file should consume. This rule applies to every file on your hard disk, so you can see how much space can be wasted.

Converting a partition to FAT32 reduces the cluster size (and overcomes the 2-GB partition size limit). For partitions 8 GB and smaller, the cluster size is reduced to a mere 4K. As you can imagine, it's not uncommon to gain back hundreds of megabytes by converting a partition to FAT32, especially if the partition contains a lot of small files.

Note: This section of the quote/ article (1999) is out of date. Updated info quote below.

As I mentioned, FAT32 does have limitations. Unfortunately, it isn't compatible with any operating system other than Windows 98 and the OSR2 version of Windows 95. However, Windows 2000 will be able to read FAT32 partitions.

The other disadvantage is that your disk utilities and antivirus software must be FAT32-aware. Otherwise, they could interpret the new file structure as an error and try to correct it, thus destroying data in the process.

Finally, I should mention that converting to FAT32 is a one-way process. Once you've converted to FAT32, you can't convert the partition back to FAT16. Therefore, before converting to FAT32, you need to consider whether the computer will ever be used in a dual-boot environment. I should also point out that although other operating systems such as Windows NT can't directly read a FAT32 partition, they can read it across the network. Therefore, it's no problem to share information stored on a FAT32 partition with other computers on a network that run older operating systems.

Updated mentioned in comment by Doktor-J (assimilated to update out of date answer in case comment is ever lost):

I'd just like to point out that most modern operating systems (WinXP/Vista/7/8, MacOS X, most if not all Linux variants) can read FAT32, contrary to what the second-to-last paragraph suggests.

The original article was written in 1999, and being posted on a Microsoft website, probably wasn't concerned with non-Microsoft operating systems anyways.

The operating systems "excluded" by that paragraph are probably the original Windows 95, Windows NT 4.0, Windows 3.1, DOS, etc.

Good PHP ORM Library?

NotORM

include "NotORM.php";
 $pdo = new PDO("mysql:dbname=software");
 $db = new NotORM($pdo);
 $applications = $db->application()
->select("id, title")
->where("web LIKE ?", "http://%")
->order("title")
->limit(10)
;
foreach ($applications as $id => $application) {
echo "$application[title]\n";
}

#1214 - The used table type doesn't support FULLTEXT indexes

Before MySQL 5.6 Full-Text Search is supported only with MyISAM Engine.

Therefore either change the engine for your table to MyISAM

CREATE TABLE gamemech_chat (
  id bigint(20) unsigned NOT NULL auto_increment,
  from_userid varchar(50) NOT NULL default '0',
  to_userid varchar(50) NOT NULL default '0',
  text text NOT NULL,
  systemtext text NOT NULL,
  timestamp datetime NOT NULL default '0000-00-00 00:00:00',
  chatroom bigint(20) NOT NULL default '0',
  PRIMARY KEY  (id),
  KEY from_userid (from_userid),
  FULLTEXT KEY from_userid_2 (from_userid),
  KEY chatroom (chatroom),
  KEY timestamp (timestamp)
) ENGINE=MyISAM;

Here is SQLFiddle demo

or upgrade to 5.6 and use InnoDB Full-Text Search.

ssh-copy-id no identities found error

You need to specify the key by using -i option.

ssh-copy-id -i your_public_key user@host

Thanks.

jQuery jump or scroll to certain position, div or target on the page from button onclick

$("html, body").scrollTop($(element).offset().top); // <-- Also integer can be used

How to install JDK 11 under Ubuntu?

I came here looking for the answer and since no one put the command for the oracle Java 11 but only openjava 11 I figured out how to do it on Ubuntu, the syntax is as following:

sudo add-apt-repository ppa:linuxuprising/java
sudo apt update
sudo apt install oracle-java11-installer

Getting the names of all files in a directory with PHP

I just use this code:

<?php
    $directory = "Images";
    echo "<div id='images'><p>$directory ...<p>";
    $Files = glob("Images/S*.jpg");
    foreach ($Files as $file) {
        echo "$file<br>";
    }
    echo "</div>";
?>

batch file Copy files with certain extensions from multiple directories into one directory

Just use the XCOPY command with recursive option

xcopy c:\*.doc k:\mybackup /sy

/s will make it "recursive"

Android: Proper Way to use onBackPressed() with Toast

additionally, you need to dissmis dialog before calling activity.super.onBackPressed(), otherwise you'll get "Activity has leaked.." error.

Example in my case with sweetalerdialog library:

 @Override
    public void onBackPressed() {
        //super.onBackPressed();
        SweetAlertDialog progressDialog = new SweetAlertDialog(this, SweetAlertDialog.WARNING_TYPE);
        progressDialog.setCancelable(false);
        progressDialog.setTitleText("Are you sure you want to exit?");
        progressDialog.setCancelText("No");
        progressDialog.setConfirmText("Yes");
        progressDialog.setCanceledOnTouchOutside(true);
        progressDialog.setConfirmClickListener(new SweetAlertDialog.OnSweetClickListener() {
            @Override
            public void onClick(SweetAlertDialog sweetAlertDialog) {
                sweetAlertDialog.dismiss();
                MainActivity.super.onBackPressed();
            }
        });
        progressDialog.show();
    }

How to make nginx to listen to server_name:port

The server_namedocs directive is used to identify virtual hosts, they're not used to set the binding.

netstat tells you that nginx listens on 0.0.0.0:80 which means that it will accept connections from any IP.

If you want to change the IP nginx binds on, you have to change the listendocs rule.
So, if you want to set nginx to bind to localhost, you'd change that to:

listen 127.0.0.1:80;

In this way, requests that are not coming from localhost are discarded (they don't even hit nginx).

Drop a temporary table if it exists

Check for the existence by retrieving its object_id:

if object_id('tempdb..##clients_keyword') is not null
    drop table ##clients_keyword

How to use random in BATCH script?

@echo off & setLocal EnableDelayedExpansion

for /L %%a in (1 1 100) do (
echo !random!
)

Horizontal Scroll Table in Bootstrap/CSS

You can also check for bootstrap datatable plugin as well for above issue.

It will have a large column table scrollable feature with lot of other options

$(document).ready(function() {
    $('#example').dataTable( {
        "scrollX": true
    } );
} );

for more info with example please check out this link

How to move Docker containers between different hosts?

Use this script: https://github.com/ricardobranco777/docker-volumes.sh

This does preserve data in volumes.

Example usage:

# Stop the container   
docker stop $CONTAINER

# Create a new image   
docker commit $CONTAINER $CONTAINER

# Save image
docker save -o $CONTAINER.tar $CONTAINER

# Save the volumes (use ".tar.gz" if you want compression)
docker-volumes.sh $CONTAINER save $CONTAINER-volumes.tar

# Copy image and volumes to another host
scp $CONTAINER.tar $CONTAINER-volumes.tar $USER@$HOST:

# On the other host:
docker load -i $CONTAINER.tar
docker create --name $CONTAINER [<PREVIOUS CONTAINER OPTIONS>] $CONTAINER

# Load the volumes
docker-volumes.sh $CONTAINER load $CONTAINER-volumes.tar

# Start container
docker start $CONTAINER

How can I check if an InputStream is empty without reading from it?

Based on the suggestion of using the PushbackInputStream, you'll find an exemple implementation here:

/**
 * @author Lorber Sebastien <i>([email protected])</i>
 */
public class NonEmptyInputStream extends FilterInputStream {

  /**
   * Once this stream has been created, do not consume the original InputStream 
   * because there will be one missing byte...
   * @param originalInputStream
   * @throws IOException
   * @throws EmptyInputStreamException
   */
  public NonEmptyInputStream(InputStream originalInputStream) throws IOException, EmptyInputStreamException {
    super( checkStreamIsNotEmpty(originalInputStream) );
  }


  /**
   * Permits to check the InputStream is empty or not
   * Please note that only the returned InputStream must be consummed.
   *
   * see:
   * http://stackoverflow.com/questions/1524299/how-can-i-check-if-an-inputstream-is-empty-without-reading-from-it
   *
   * @param inputStream
   * @return
   */
  private static InputStream checkStreamIsNotEmpty(InputStream inputStream) throws IOException, EmptyInputStreamException {
    Preconditions.checkArgument(inputStream != null,"The InputStream is mandatory");
    PushbackInputStream pushbackInputStream = new PushbackInputStream(inputStream);
    int b;
    b = pushbackInputStream.read();
    if ( b == -1 ) {
      throw new EmptyInputStreamException("No byte can be read from stream " + inputStream);
    }
    pushbackInputStream.unread(b);
    return pushbackInputStream;
  }

  public static class EmptyInputStreamException extends RuntimeException {
    public EmptyInputStreamException(String message) {
      super(message);
    }
  }

}

And here are some passing tests:

  @Test(expected = EmptyInputStreamException.class)
  public void test_check_empty_input_stream_raises_exception_for_empty_stream() throws IOException {
    InputStream emptyStream = new ByteArrayInputStream(new byte[0]);
    new NonEmptyInputStream(emptyStream);
  }

  @Test
  public void test_check_empty_input_stream_ok_for_non_empty_stream_and_returned_stream_can_be_consummed_fully() throws IOException {
    String streamContent = "HELLooooô wörld";
    InputStream inputStream = IOUtils.toInputStream(streamContent, StandardCharsets.UTF_8);
    inputStream = new NonEmptyInputStream(inputStream);
    assertThat(IOUtils.toString(inputStream,StandardCharsets.UTF_8)).isEqualTo(streamContent);
  }

Creating SolidColorBrush from hex color value

using System.Windows.Media;

byte R = Convert.ToByte(color.Substring(1, 2), 16);
byte G = Convert.ToByte(color.Substring(3, 2), 16);
byte B = Convert.ToByte(color.Substring(5, 2), 16);
SolidColorBrush scb = new SolidColorBrush(Color.FromRgb(R, G, B));
//applying the brush to the background of the existing Button btn:
btn.Background = scb;

UITextField text change event

Swift 3.1:

Selector: ClassName.MethodName

  cell.lblItem.addTarget(self, action: #selector(NewListScreen.fieldChanged(textfieldChange:)), for: .editingChanged)

  func fieldChanged(textfieldChange: UITextField){

    }

Get Environment Variable from Docker Container

@aisbaa's answer works if you don't care when the environment variable was declared. If you want the environment variable, even if it has been declared inside of an exec /bin/bash session, use something like:

IFS="=" read -a out <<< $(docker exec container /bin/bash -c "env | grep ENV_VAR" 2>&1)

It's not very pretty, but it gets the job done.

To then get the value, use:

echo ${out[1]}

JSON and escaping characters

hmm, well here's a workaround anyway:

function JSON_stringify(s, emit_unicode)
{
   var json = JSON.stringify(s);
   return emit_unicode ? json : json.replace(/[\u007f-\uffff]/g,
      function(c) { 
        return '\\u'+('0000'+c.charCodeAt(0).toString(16)).slice(-4);
      }
   );
}

test case:

js>s='15\u00f8C 3\u0111';
15°C 3?
js>JSON_stringify(s, true)
"15°C 3?"
js>JSON_stringify(s, false)
"15\u00f8C 3\u0111"

How can I save an image with PIL?

The error regarding the file extension has been handled, you either use BMP (without the dot) or pass the output name with the extension already. Now to handle the error you need to properly modify your data in the frequency domain to be saved as an integer image, PIL is telling you that it doesn't accept float data to save as BMP.

Here is a suggestion (with other minor modifications, like using fftshift and numpy.array instead of numpy.asarray) for doing the conversion for proper visualization:

import sys
import numpy
from PIL import Image

img = Image.open(sys.argv[1]).convert('L')

im = numpy.array(img)
fft_mag = numpy.abs(numpy.fft.fftshift(numpy.fft.fft2(im)))

visual = numpy.log(fft_mag)
visual = (visual - visual.min()) / (visual.max() - visual.min())

result = Image.fromarray((visual * 255).astype(numpy.uint8))
result.save('out.bmp')

Hide axis values but keep axis tick labels in matplotlib

This works great. Just paste this before plt.show():

plt.gca().axes.get_yaxis().set_visible(False)

Boom.

S3 Static Website Hosting Route All Paths to Index.html

since the problem is still there I though I throw in another solution. My case was that I wanted to auto deploy all pull requests to s3 for testing before merge making them accessible on [mydomain]/pull-requests/[pr number]/
(ex. www.example.com/pull-requests/822/)

To the best of my knowledge non of s3 rules scenarios would allow to have multiple projects in one bucket using html5 routing so while above most voted suggestion works for a project in root folder, it doesn't for multiple projects in own subfolders.

So I pointed my domain to my server where following nginx config did the job

location /pull-requests/ {
    try_files $uri @get_files;
}
location @get_files {
    rewrite ^\/pull-requests\/(.*) /$1 break;
    proxy_pass http://<your-amazon-bucket-url>;
    proxy_intercept_errors on;
    recursive_error_pages on;
    error_page 404 = @get_routes;
}

location @get_routes {
    rewrite ^\/(\w+)\/(.+) /$1/ break;
    proxy_pass http://<your-amazon-bucket-url>;
    proxy_intercept_errors on;
    recursive_error_pages on;
    error_page 404 = @not_found;
}

location @not_found {
    return 404;
}

it tries to get the file and if not found assumes it is html5 route and tries that. If you have a 404 angular page for not found routes you will never get to @not_found and get you angular 404 page returned instead of not found files, which could be fixed with some if rule in @get_routes or something.

I have to say I don't feel too comfortable in area of nginx config and using regex for that matter, I got this working with some trial and error so while this works I am sure there is room for improvement and please do share your thoughts.

Note: remove s3 redirection rules if you had them in S3 config.

and btw works in Safari

Defined Edges With CSS3 Filter Blur

I used -webkit-transform: translate3d(0, 0, 0); with overflow:hidden;.

DOM:

<div class="parent">
    <img class="child" src="http://placekitten.com/100" />
</div>

CSS:

.parent {
    width: 100px;
    height: 100px;
    overflow: hidden;
    -webkit-transform: translate3d(0, 0, 0);
}
.child {
    -webkit-filter: blur(10px);
}

DEMO: http://jsfiddle.net/DA5L4/18/

This technic works on Chrome34 and iOS7.1

Update

http://jsfiddle.net/DA5L4/50/

if you use latest version of Chrome, you don't need to use -webkit-transform: translate3d(0, 0, 0); hack. But it doesn't works on Safari(webkit).

Create JPA EntityManager without persistence.xml configuration file

You can also get an EntityManager using PersistenceContext or Autowired annotation, but be aware that it will not be thread-safe.

@PersistenceContext
private EntityManager entityManager;

Python handling socket.error: [Errno 104] Connection reset by peer

There is a way to catch the error directly in the except clause with ConnectionResetError, better to isolate the right error. This example also catches the timeout.

from urllib.request import urlopen 
from socket import timeout

url = "http://......"
try: 
    string = urlopen(url, timeout=5).read()
except ConnectionResetError:
    print("==> ConnectionResetError")
    pass
except timeout: 
    print("==> Timeout")
    pass

How can I listen for keypress event on the whole page?

I would use @HostListener decorator within your component:

import { HostListener } from '@angular/core';

@Component({
  ...
})
export class AppComponent {

  @HostListener('document:keypress', ['$event'])
  handleKeyboardEvent(event: KeyboardEvent) { 
    this.key = event.key;
  }
}

There are also other options like:

host property within @Component decorator

Angular recommends using @HostListener decorator over host property https://angular.io/guide/styleguide#style-06-03

@Component({
  ...
  host: {
    '(document:keypress)': 'handleKeyboardEvent($event)'
  }
})
export class AppComponent {
  handleKeyboardEvent(event: KeyboardEvent) {
    console.log(event);
  }
}

renderer.listen

import { Component, Renderer2 } from '@angular/core';

@Component({
  ...
})
export class AppComponent {
  globalListenFunc: Function;

  constructor(private renderer: Renderer2) {}

  ngOnInit() {
    this.globalListenFunc = this.renderer.listen('document', 'keypress', e => {
      console.log(e);
    });
  }

  ngOnDestroy() {
    // remove listener
    this.globalListenFunc();
  }
}

Observable.fromEvent

import { Observable } from 'rxjs/Observable';
import 'rxjs/add/observable/fromEvent';
import { Subscription } from 'rxjs/Subscription';

@Component({
  ...
})
export class AppComponent {
  subscription: Subscription;

  ngOnInit() {
    this.subscription = Observable.fromEvent(document, 'keypress').subscribe(e => {
      console.log(e);
    })
  }

  ngOnDestroy() {
    this.subscription.unsubscribe();
  }
}

AngularJs event to call after content is loaded

The solution that work for me is the following

app.directive('onFinishRender', ['$timeout', '$parse', function ($timeout, $parse) {
    return {
        restrict: 'A',
        link: function (scope, element, attr) {
            if (scope.$last === true) {
                $timeout(function () {
                    scope.$emit('ngRepeatFinished');
                    if (!!attr.onFinishRender) {
                        $parse(attr.onFinishRender)(scope);
                    }
                });
            }

            if (!!attr.onStartRender) {
                if (scope.$first === true) {
                    $timeout(function () {
                        scope.$emit('ngRepeatStarted');
                        if (!!attr.onStartRender) {
                            $parse(attr.onStartRender)(scope);
                        }
                    });
                }
            }
        }
    }
}]);

Controller code is the following

$scope.crearTooltip = function () {
     $('[data-toggle="popover"]').popover();
}

Html code is the following

<tr ng-repeat="item in $data" on-finish-render="crearTooltip()">

What is the difference between the float and integer data type when the size is the same?

  • float stores floating-point values, that is, values that have potential decimal places
  • int only stores integral values, that is, whole numbers

So while both are 32 bits wide, their use (and representation) is quite different. You cannot store 3.141 in an integer, but you can in a float.

Dissecting them both a little further:

In an integer, all bits are used to store the number value. This is (in Java and many computers too) done in the so-called two's complement. This basically means that you can represent the values of −231 to 231 − 1.

In a float, those 32 bits are divided between three distinct parts: The sign bit, the exponent and the mantissa. They are laid out as follows:

S EEEEEEEE MMMMMMMMMMMMMMMMMMMMMMM

There is a single bit that determines whether the number is negative or non-negative (zero is neither positive nor negative, but has the sign bit set to zero). Then there are eight bits of an exponent and 23 bits of mantissa. To get a useful number from that, (roughly) the following calculation is performed:

M × 2E

(There is more to it, but this should suffice for the purpose of this discussion)

The mantissa is in essence not much more than a 24-bit integer number. This gets multiplied by 2 to the power of the exponent part, which, roughly, is a number between −128 and 127.

Therefore you can accurately represent all numbers that would fit in a 24-bit integer but the numeric range is also much greater as larger exponents allow for larger values. For example, the maximum value for a float is around 3.4 × 1038 whereas int only allows values up to 2.1 × 109.

But that also means, since 32 bits only have 4.2 × 109 different states (which are all used to represent the values int can store), that at the larger end of float's numeric range the numbers are spaced wider apart (since there cannot be more unique float numbers than there are unique int numbers). You cannot represent some numbers exactly, then. For example, the number 2 × 1012 has a representation in float of 1,999,999,991,808. That might be close to 2,000,000,000,000 but it's not exact. Likewise, adding 1 to that number does not change it because 1 is too small to make a difference in the larger scales float is using there.

Similarly, you can also represent very small numbers (between 0 and 1) in a float but regardless of whether the numbers are very large or very small, float only has a precision of around 6 or 7 decimal digits. If you have large numbers those digits are at the start of the number (e.g. 4.51534 × 1035, which is nothing more than 451534 follows by 30 zeroes – and float cannot tell anything useful about whether those 30 digits are actually zeroes or something else), for very small numbers (e.g. 3.14159 × 10−27) they are at the far end of the number, way beyond the starting digits of 0.0000...

int array to string

If this is long array you could use

var sb = arr.Aggregate(new StringBuilder(), ( s, i ) => s.Append( i ), s.ToString());

How do I find out which process is locking a file using .NET?

One of the good things about handle.exe is that you can run it as a subprocess and parse the output.

We do this in our deployment script - works like a charm.

Adding multiple class using ng-class

Using a $scope method on the controller, you can calculate what classes to output in the view. This is especially handy if you have a complex logic for calculating class names and it will reduce the amount of logic in your view by moving it to the controller:

app.controller('myController', function($scope) {

    $scope.className = function() {

        var className = 'initClass';

        if (condition1())
            className += ' class1';

        if (condition2())
            className += ' class2';

        return className;
    };
});

and in the view, simply:

<div ng-class="className()"></div>

How to get enum value by string or int

You could use following method to do that:

public static Output GetEnumItem<Output, Input>(Input input)
    {
        //Output type checking...
        if (typeof(Output).BaseType != typeof(Enum))
            throw new Exception("Exception message...");

        //Input type checking: string type
        if (typeof(Input) == typeof(string))
            return (Output)Enum.Parse(typeof(Output), (dynamic)input);

        //Input type checking: Integer type
        if (typeof(Input) == typeof(Int16) ||
            typeof(Input) == typeof(Int32) ||
            typeof(Input) == typeof(Int64))

            return (Output)(dynamic)input;

        throw new Exception("Exception message...");
    }

Note:this method only is a sample and you can improve it.

Spark DataFrame groupBy and sort in the descending order (pyspark)

In PySpark 1.3 sort method doesn't take ascending parameter. You can use desc method instead:

from pyspark.sql.functions import col

(group_by_dataframe
    .count()
    .filter("`count` >= 10")
    .sort(col("count").desc()))

or desc function:

from pyspark.sql.functions import desc

(group_by_dataframe
    .count()
    .filter("`count` >= 10")
    .sort(desc("count"))

Both methods can be used with with Spark >= 1.3 (including Spark 2.x).

printf %f with only 2 numbers after the decimal point?

Use this:

printf ("%.2f", 3.14159);

IndexOf function in T-SQL

I believe you want to use CHARINDEX. You can read about it here.

How to delete all files older than 3 days when "Argument list too long"?

Another solution for the original question, esp. useful if you want to remove only SOME of the older files in a folder, would be smth like this:

find . -name "*.sess" -mtime +100 

and so on.. Quotes block shell wildcards, thus allowing you to "find" millions of files :)

Showing all errors and warnings

Set these on php.ini:

;display_startup_errors = On
display_startup_errors=off
display_errors =on
html_errors= on

From your PHP page, use a suitable filter for error reporting.

error_reporting(E_ALL);

Filers can be made according to requirements.

E_ALL
E_ALL | E_STRICT

Left join only selected columns in R with the merge() function

I think it's a little simpler to use the dplyr functions select and left_join ; at least it's easier for me to understand. The join function from dplyr are made to mimic sql arguments.

 library(tidyverse)

 DF2 <- DF2 %>%
   select(client, LO)

 joined_data <- left_join(DF1, DF2, by = "Client")

You don't actually need to use the "by" argument in this case because the columns have the same name.

PHP - Getting the index of a element from a array

You should use the key() function.

key($array)

should return the current key.

If you need the position of the current key:

array_search($key, array_keys($array));

How to read from a text file using VBScript?

Use first the method OpenTextFile, and then...

either read the file at once with the method ReadAll:

Set file = fso.OpenTextFile("C:\test.txt", 1)
content = file.ReadAll

or line by line with the method ReadLine:

Set dict = CreateObject("Scripting.Dictionary")
Set file = fso.OpenTextFile ("c:\test.txt", 1)
row = 0
Do Until file.AtEndOfStream
  line = file.Readline
  dict.Add row, line
  row = row + 1
Loop

file.Close

'Loop over it
For Each line in dict.Items
  WScript.Echo line
Next

Python: Removing list element while iterating over list

Not exactly in-place, but some idea to do it:

a = ['a', 'b']

def inplace(a):
    c = []
    while len(a) > 0:
        e = a.pop(0)
        if e == 'b':
            c.append(e)
    a.extend(c)

You can extend the function to call you filter in the condition.

The maximum value for an int type in Go

I would use math package for getting the maximal value and minimal value :

func printMinMaxValue() {
    // integer max
    fmt.Printf("max int64 = %+v\n", math.MaxInt64)
    fmt.Printf("max int32 = %+v\n", math.MaxInt32)
    fmt.Printf("max int16 = %+v\n", math.MaxInt16)

    // integer min
    fmt.Printf("min int64 = %+v\n", math.MinInt64)
    fmt.Printf("min int32 = %+v\n", math.MinInt32)

    fmt.Printf("max flloat64= %+v\n", math.MaxFloat64)
    fmt.Printf("max float32= %+v\n", math.MaxFloat32)

    // etc you can see more int the `math`package
}

Ouput :

max int64 = 9223372036854775807
max int32 = 2147483647
max int16 = 32767
min int64 = -9223372036854775808
min int32 = -2147483648
max flloat64= 1.7976931348623157e+308
max float32= 3.4028234663852886e+38

Why would you use Expression<Func<T>> rather than Func<T>?

Overly simplified here, but Func is a machine, whereas Expression is a blueprint. :D

Argument of type 'X' is not assignable to parameter of type 'X'

This problem basically comes when your compiler gets failed to understand the difference between cast operator of the type string to Number.

you can use the Number object and pass your value to get the appropriate results for it by using Number(<<<<...Variable_Name......>>>>)

React passing parameter via onclick event using ES6 syntax

TL;DR:

Don't bind function (nor use arrow functions) inside render method. See official recommendations.

https://reactjs.org/docs/faq-functions.html


So, there's an accepted answer and a couple more that points the same. And also there are some comments preventing people from using bind within the render method, and also avoiding arrow functions there for the same reason (those functions will be created once again and again on each render). But there's no example, so I'm writing one.

Basically, you have to bind your functions in the constructor.

class Actions extends Component {

    static propTypes = {
        entity_id: PropTypes.number,
        contact_id: PropTypes.number,
        onReplace: PropTypes.func.isRequired,
        onTransfer: PropTypes.func.isRequired
    }

    constructor() {
        super();
        this.onReplace = this.onReplace.bind(this);
        this.onTransfer = this.onTransfer.bind(this);
    }

    onReplace() {
        this.props.onReplace(this.props.entity_id, this.props.contact_id);
    }

    onTransfer() {
        this.props.onTransfer(this.props.entity_id, this.props.contact_id);
    }

    render() {
        return (
            <div className="actions">
                <button className="btn btn-circle btn-icon-only btn-default"
                    onClick={this.onReplace}
                    title="Replace">
                        <i className="fa fa-refresh"></i>
                </button>
                <button className="btn btn-circle btn-icon-only btn-default"
                    onClick={this.onTransfer}
                    title="Transfer">
                    <i className="fa fa-share"></i>
                </button>                                 
            </div>
        )
    }
}

export default Actions

Key lines are:

constructor

this.onReplace = this.onReplace.bind(this);

method

onReplace() {
    this.props.onReplace(this.props.entity_id, this.props.contact_id);
}

render

onClick={this.onReplace}

LINQ to SQL - How to select specific columns and return strongly typed list

Basically you are doing it the right way. However, you should use an instance of the DataContext for querying (it's not obvious that DataContext is an instance or the type name from your query):

var result = (from a in new DataContext().Persons
              where a.Age > 18
              select new Person { Name = a.Name, Age = a.Age }).ToList();

Apparently, the Person class is your LINQ to SQL generated entity class. You should create your own class if you only want some of the columns:

class PersonInformation {
   public string Name {get;set;}
   public int Age {get;set;}
}

var result = (from a in new DataContext().Persons
              where a.Age > 18
              select new PersonInformation { Name = a.Name, Age = a.Age }).ToList();

You can freely swap var with List<PersonInformation> here without affecting anything (as this is what the compiler does).

Otherwise, if you are working locally with the query, I suggest considering an anonymous type:

var result = (from a in new DataContext().Persons
              where a.Age > 18
              select new { a.Name, a.Age }).ToList();

Note that in all of these cases, the result is statically typed (it's type is known at compile time). The latter type is a List of a compiler generated anonymous class similar to the PersonInformation class I wrote above. As of C# 3.0, there's no dynamic typing in the language.

UPDATE:

If you really want to return a List<Person> (which might or might not be the best thing to do), you can do this:

var result = from a in new DataContext().Persons
             where a.Age > 18
             select new { a.Name, a.Age };

List<Person> list = result.AsEnumerable()
                          .Select(o => new Person {
                                           Name = o.Name, 
                                           Age = o.Age
                          }).ToList();

You can merge the above statements too, but I separated them for clarity.

React Native android build failed. SDK location not found

I am on Windows and I had to modify sdk path irrespective of having it in PATH env. variable

sdk.dir=C:/Users/MY_USERNAME/AppData/Local/Android/Sdk

Changed this file:

MyProject\android\local.properties

Specify a Root Path of your HTML directory for script links?

This is oddly confusing to me. I know it shouldn't be. To check my understanding, I'd like to use a family relations model to compare. Assuming "You" is the current webpage, is the following correct?

<img src="picture.jpg">            In your folder with you, like a sibling
<img src="images/picture.jpg">     In your child's folder, under you
<img src="../picture.jpg">         In your parent's folder, above you
<img src="/images/picture.jpg">    In your cousin's folder

So, up to parent, over to sibling, down to their child = your cousin, named "images".

The import org.junit cannot be resolved

If you use maven and this piece of code is located in the main folder, try relocating it to the test folder.

What exactly is the meaning of an API?

Lets say you are developing a game and you want the game user to login their facebook profile(to get your profile information) before playing it,so how your game is going to access facebook? Now here comes the API.Facebook has already written the program(API) for you to do it, you have to just use those programs in your game application.using Facebook-API you can use their services in your application.Here is a good and detailed look on API... http://money.howstuffworks.com/business-communications/how-to-leverage-an-api-for-conferencing1.htm

Convert one date format into another in PHP

To convert $date from dd-mm-yyyy hh:mm:ss to a proper MySQL datetime I go like this:

$date = DateTime::createFromFormat('d-m-Y H:i:s',$date)->format('Y-m-d H:i:s');

Difference between Pig and Hive? Why have both?

In Simpler words, Pig is a high-level platform for creating MapReduce programs used with Hadoop, using pig scripts we will process the large amount of data into desired format.

Once the processed data obtained, this processed data is kept in HDFS for later processing to obtain the desired results.

On top of the stored processed data we will apply HIVE SQL commands to get the desired results, internally this hive sql commands runs MAP Reduce programs.

Eclipse - Installing a new JRE (Java SE 8 1.8.0)

You can have many java versions in your system.

I think you should add the java 8 in yours JREs installed or edit.

Take a look my screen:

enter image description here

If you click in edit (check your java 8 path):

enter image description here

Indexes of all occurrences of character in a string

This should print the list of positions without the -1 at the end that Peter Lawrey's solution has had.

int index = word.indexOf(guess);
while (index >= 0) {
    System.out.println(index);
    index = word.indexOf(guess, index + 1);
}

It can also be done as a for loop:

for (int index = word.indexOf(guess);
     index >= 0;
     index = word.indexOf(guess, index + 1))
{
    System.out.println(index);
}

[Note: if guess can be longer than a single character, then it is possible, by analyzing the guess string, to loop through word faster than the above loops do. The benchmark for such an approach is the Boyer-Moore algorithm. However, the conditions that would favor using such an approach do not seem to be present.]

How to split a long array into smaller arrays, with JavaScript

Just loop over the array, splicing it until it's all consumed.



var a = ['a','b','c','d','e','f','g']
  , chunk

while (a.length > 0) {

  chunk = a.splice(0,3)

  console.log(chunk)

}

output


[ 'a', 'b', 'c' ]
[ 'd', 'e', 'f' ]
[ 'g' ]

JavaScript math, round to two decimal places

NOTE - See Edit 4 if 3 digit precision is important

var discount = (price / listprice).toFixed(2);

toFixed will round up or down for you depending on the values beyond 2 decimals.

Example: http://jsfiddle.net/calder12/tv9HY/

Documentation: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number/toFixed

Edit - As mentioned by others this converts the result to a string. To avoid this:

var discount = +((price / listprice).toFixed(2));

Edit 2- As also mentioned in the comments this function fails in some precision, in the case of 1.005 for example it will return 1.00 instead of 1.01. If accuracy to this degree is important I've found this answer: https://stackoverflow.com/a/32605063/1726511 Which seems to work well with all the tests I've tried.

There is one minor modification required though, the function in the answer linked above returns whole numbers when it rounds to one, so for example 99.004 will return 99 instead of 99.00 which isn't ideal for displaying prices.

Edit 3 - Seems having the toFixed on the actual return was STILL screwing up some numbers, this final edit appears to work. Geez so many reworks!

var discount = roundTo((price / listprice), 2);

function roundTo(n, digits) {
  if (digits === undefined) {
    digits = 0;
  }

  var multiplicator = Math.pow(10, digits);
  n = parseFloat((n * multiplicator).toFixed(11));
  var test =(Math.round(n) / multiplicator);
  return +(test.toFixed(digits));
}

See Fiddle example here: https://jsfiddle.net/calder12/3Lbhfy5s/

Edit 4 - You guys are killing me. Edit 3 fails on negative numbers, without digging into why it's just easier to deal with turning a negative number positive before doing the rounding, then turning it back before returning the result.

function roundTo(n, digits) {
    var negative = false;
    if (digits === undefined) {
        digits = 0;
    }
    if (n < 0) {
        negative = true;
        n = n * -1;
    }
    var multiplicator = Math.pow(10, digits);
    n = parseFloat((n * multiplicator).toFixed(11));
    n = (Math.round(n) / multiplicator).toFixed(digits);
    if (negative) {
        n = (n * -1).toFixed(digits);
    }
    return n;
}

Fiddle: https://jsfiddle.net/3Lbhfy5s/79/

How to use Google Translate API in my Java application?

You can use Google Translate API v2 Java. It has a core module that you can call from your Java code and also a command line interface module.

In Bash, how to add "Are you sure [Y/n]" to any command or alias?

Well, here's my version of confirm, modified from James' one:

function confirm() {
  local response msg="${1:-Are you sure} (y/[n])? "; shift
  read -r $* -p "$msg" response || echo
  case "$response" in
  [yY][eE][sS]|[yY]) return 0 ;;
  *) return 1 ;;
  esac
}

These changes are:

  1. use local to prevent variable names from colliding
  2. read use $2 $3 ... to control its action, so you may use -n and -t
  3. if read exits unsuccessfully, echo a line feed for beauty
  4. my Git on Windows only has bash-3.1 and has no true or false, so use return instead. Of course, this is also compatible with bash-4.4 (the current one in Git for Windows).
  5. use IPython-style "(y/[n])" to clearly indicate that "n" is the default.

How do I convert an array object to a string in PowerShell?

From a pipe

# This Is a cat
'This', 'Is', 'a', 'cat' | & {"$input"}

# This-Is-a-cat
'This', 'Is', 'a', 'cat' | & {$ofs='-';"$input"}

Write-Host

# This Is a cat
Write-Host 'This', 'Is', 'a', 'cat'

# This-Is-a-cat
Write-Host -Separator '-' 'This', 'Is', 'a', 'cat'

Example

QLabel: set color of text and background

I add this answer because I think it could be useful to anybody.

I step into the problem of setting RGBA colors (that is, RGB color with an Alpha value for transparency) for color display labels in my painting application.

As I came across the first answer, I was unable to set an RGBA color. I have also tried things like:

myLabel.setStyleSheet("QLabel { background-color : %s"%color.name())

where color is an RGBA color.

So, my dirty solution was to extend QLabel and override paintEvent() method filling its bounding rect.

Today, I've open up the qt-assistant and read the style reference properties list. Affortunately, it has an example that states the following:

QLineEdit { background-color: rgb(255, 0, 0) }

Thats open up my mind in doing something like the code below, as an example:

myLabel= QLabel()
myLabel.setAutoFillBackground(True) # This is important!!
color  = QtGui.QColor(233, 10, 150)
alpha  = 140
values = "{r}, {g}, {b}, {a}".format(r = color.red(),
                                     g = color.green(),
                                     b = color.blue(),
                                     a = alpha
                                     )
myLabel.setStyleSheet("QLabel { background-color: rgba("+values+"); }")

Note that setAutoFillBackground() set in False will not make it work.

Regards,

How to top, left justify text in a <td> cell that spans multiple rows

try this

_x000D_
_x000D_
<!DOCTYPE html>_x000D_
<html>_x000D_
<head>_x000D_
<style>_x000D_
table, th, td {_x000D_
    border: 1px solid black;_x000D_
}_x000D_
</style>_x000D_
</head>_x000D_
<body>_x000D_
_x000D_
<table style="width:50%;">_x000D_
    <tr>_x000D_
      <th>Month</th>_x000D_
      <th>Savings</th>_x000D_
    </tr>_x000D_
    <tr style="height:100px">_x000D_
      <td valign="top">January</td>_x000D_
      <td valign="bottom">$100</td>_x000D_
    </tr>_x000D_
</table>_x000D_
_x000D_
<p><b>Note:</b> The valign attribute is not supported in HTML5. Use CSS instead.</p>_x000D_
_x000D_
</body>_x000D_
</html>
_x000D_
_x000D_
_x000D_

use valign="top" for td style

How to fix nginx throws 400 bad request headers on any header testing tools?

Just to clearify, in /etc/nginx/nginx.conf, you can put at the beginning of the file the line

error_log /var/log/nginx/error.log debug;

And then restart nginx:

sudo service nginx restart

That way you can detail what nginx is doing and why it is returning the status code 400.

ojdbc14.jar vs. ojdbc6.jar

I have same problem!

Found following in oracle site link text

As mentioned above, the 11.1 drivers by default convert SQL DATE to Timestamp when reading from the database. This always was the right thing to do and the change in 9i was a mistake. The 11.1 drivers have reverted to the correct behavior. Even if you didn't set V8Compatible in your application you shouldn't see any difference in behavior in most cases. You may notice a difference if you use getObject to read a DATE column. The result will be a Timestamp rather than a Date. Since Timestamp is a subclass of Date this generally isn't a problem. Where you might notice a difference is if you relied on the conversion from DATE to Date to truncate the time component or if you do toString on the value. Otherwise the change should be transparent.

If for some reason your app is very sensitive to this change and you simply must have the 9i-10g behavior, there is a connection property you can set. Set mapDateToTimestamp to false and the driver will revert to the default 9i-10g behavior and map DATE to Date.

How do I use a regex in a shell script?

the problem is you're trying to use regex features not supported by grep. namely, your \d won't work. use this instead:

REGEX_DATE="^[[:digit:]]{2}[-/][[:digit:]]{2}[-/][[:digit:]]{4}$"
echo "$1" | grep -qE "${REGEX_DATE}"
echo $?

you need the -E flag to get ERE in order to use {#} style.

Default username password for Tomcat Application Manager

The admin and manager apps are two separate things. Here's a snapshot of a tomcat-users.xml file that works, try this:

<?xml version='1.0' encoding='utf-8'?>  
<tomcat-users>  
    <role rolename="tomcat"/>  
    <role rolename="role1"/>  
    <role rolename="manager"/>  
    <user username="tomcat" password="tomcat" roles="tomcat"/>  
    <user username="both" password="tomcat" roles="tomcat,role1"/>  
    <user username="role1" password="tomcat" roles="role1"/>  
    <user username="USERNAME" password="PASSWORD" roles="manager,tomcat,role1"/>  
</tomcat-users>  

It works for me very well

How to generate a random number between a and b in Ruby?

See this answer: there is in Ruby 1.9.2, but not in earlier versions. Personally I think rand(8) + 3 is fine, but if you're interested check out the Random class described in the link.

XPath - Difference between node() and text()

Select the text of all items under produce:

//produce/item/text()

Select all the manager nodes in all departments:

//department/*

Differences between time complexity and space complexity?

Time and Space complexity are different aspects of calculating the efficiency of an algorithm.

Time complexity deals with finding out how the computational time of an algorithm changes with the change in size of the input.

On the other hand, space complexity deals with finding out how much (extra)space would be required by the algorithm with change in the input size.

To calculate time complexity of the algorithm the best way is to check if we increase in the size of the input, will the number of comparison(or computational steps) also increase and to calculate space complexity the best bet is to see additional memory requirement of the algorithm also changes with the change in the size of the input.

A good example could be of Bubble sort.

Lets say you tried to sort an array of 5 elements. In the first pass you will compare 1st element with next 4 elements. In second pass you will compare 2nd element with next 3 elements and you will continue this procedure till you fully exhaust the list.

Now what will happen if you try to sort 10 elements. In this case you will start with comparing comparing 1st element with next 9 elements, then 2nd with next 8 elements and so on. In other words if you have N element array you will start of by comparing 1st element with N-1 elements, then 2nd element with N-2 elements and so on. This results in O(N^2) time complexity.

But what about size. When you sorted 5 element or 10 element array did you use any additional buffer or memory space. You might say Yes, I did use a temporary variable to make the swap. But did the number of variables changed when you increased the size of array from 5 to 10. No, Irrespective of what is the size of the input you will always use a single variable to do the swap. Well, this means that the size of the input has nothing to do with the additional space you will require resulting in O(1) or constant space complexity.

Now as an exercise for you, research about the time and space complexity of merge sort

Sending and Parsing JSON Objects in Android

GSON is easiest to use and the way to go if the data have a definite structure.

Download gson.

Add it to the referenced libraries.

package com.tut.JSON;

import org.json.JSONException;
import org.json.JSONObject;

import android.app.Activity;
import android.os.Bundle;
import android.util.Log;

import com.google.gson.Gson;
import com.google.gson.GsonBuilder;

public class SimpleJson extends Activity {
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

        String jString = "{\"username\": \"tom\", \"message\": \"roger that\"}  ";


        GsonBuilder gsonb = new GsonBuilder();
        Gson gson = gsonb.create();
        Post pst;

        try {
            pst = gson.fromJson(jString,  Post.class);

        } catch (JSONException e) {
            e.printStackTrace();
        }
    }
}

Code for Post class

package com.tut.JSON;

public class Post {

    String message;
    String time;
    String username;
    Bitmap icon;
}

Installing specific laravel version with composer create-project

If you want to use a stable version of your preferred Laravel version of choice, use:

composer create-project --prefer-dist laravel/laravel project-name "5.5.*"

That will pick out the most recent or best update of version 5.5.* (5.5.28)

iterating quickly through list of tuples

Assuming a bit more memory usage is not a problem and if the first item of your tuple is hashable, you can create a dict out of your list of tuples and then looking up the value is as simple as looking up a key from the dict. Something like:

dct = dict(tuples)
val = dct.get(key) # None if item not found else the corresponding value

EDIT: To create a reverse mapping, use something like:

revDct = dict((val, key) for (key, val) in tuples)

SQL Server Case Statement when IS NULL

In this situation you can use ISNULL() function instead of CASE expression

ISNULL(B.[STAT], C.[EVENT DATE]+10) AS [DATE]

Ruby: How to turn a hash into HTTP parameters?

Update: This functionality was removed from the gem.

Julien, your self-answer is a good one, and I've shameless borrowed from it, but it doesn't properly escape reserved characters, and there are a few other edge cases where it breaks down.

require "addressable/uri"
uri = Addressable::URI.new
uri.query_values = {:a => "a", :b => ["c", "d", "e"]}
uri.query
# => "a=a&b[0]=c&b[1]=d&b[2]=e"
uri.query_values = {:a => "a", :b => [{:c => "c", :d => "d"}, {:e => "e", :f => "f"}]}
uri.query
# => "a=a&b[0][c]=c&b[0][d]=d&b[1][e]=e&b[1][f]=f"
uri.query_values = {:a => "a", :b => {:c => "c", :d => "d"}}
uri.query
# => "a=a&b[c]=c&b[d]=d"
uri.query_values = {:a => "a", :b => {:c => "c", :d => true}}
uri.query
# => "a=a&b[c]=c&b[d]"
uri.query_values = {:a => "a", :b => {:c => "c", :d => true}, :e => []}
uri.query
# => "a=a&b[c]=c&b[d]"

The gem is 'addressable'

gem install addressable

SVN remains in conflict?

Instructions for Tortoise SVN

Navigate to the directory where you see this error. If you do not have any changes perform the following

a. Right click and do a 'Revert'
b. Select all the files
c. Then update the directory again

How to turn on front flash light programmatically in Android?

I Got AutoFlash light with below simple Three Steps.

  • I just added Camera and Flash Permission in Manifest.xml file
<uses-permission android:name="android.permission.CAMERA" />
<uses-feature android:name="android.hardware.camera" />

<uses-permission android:name="android.permission.FLASHLIGHT"/>
<uses-feature android:name="android.hardware.camera.flash" android:required="false" />
  • In your Camera Code do this way.

    //Open Camera
    Camera  mCamera = Camera.open(); 
    
    //Get Camera Params for customisation
    Camera.Parameters parameters = mCamera.getParameters();
    
    //Check Whether device supports AutoFlash, If you YES then set AutoFlash
    List<String> flashModes = parameters.getSupportedFlashModes();
    if (flashModes.contains(android.hardware.Camera.Parameters.FLASH_MODE_AUTO))
    {
         parameters.setFlashMode(Parameters.FLASH_MODE_AUTO);
    }
    mCamera.setParameters(parameters);
    mCamera.startPreview();
    
  • Build + Run —> Now Go to Dim light area and Snap photo, you should get auto flash light if device supports.

How to redirect to a different domain using NGINX?

Temporary redirect

rewrite ^ http://www.RedirectToThisDomain.com$request_uri? redirect;

Permanent redirect

rewrite ^ http://www.RedirectToThisDomain.com$request_uri? permanent;

In nginx configuration file for specific site:

server {    
    server_name www.example.com;
    rewrite ^ http://www.RedictToThisDomain.com$request_uri? redirect;

}

Wildcard string comparison in Javascript

This function convert wildcard to regexp and make test (it supports . and * wildcharts)

function wildTest(wildcard, str) {
  let w = wildcard.replace(/[.+^${}()|[\]\\]/g, '\\$&'); // regexp escape 
  const re = new RegExp(`^${w.replace(/\*/g,'.*').replace(/\?/g,'.')}$`,'i');
  return re.test(str); // remove last 'i' above to have case sensitive
}

_x000D_
_x000D_
function wildTest(wildcard, str) {_x000D_
  let w = wildcard.replace(/[.+^${}()|[\]\\]/g, '\\$&'); // regexp escape _x000D_
  const re = new RegExp(`^${w.replace(/\*/g,'.*').replace(/\?/g,'.')}$`,'i');_x000D_
  return re.test(str); // remove last 'i' above to have case sensitive_x000D_
}_x000D_
_x000D_
_x000D_
// Example usage_x000D_
_x000D_
let arr = ["birdBlue", "birdRed", "pig1z", "pig2z", "elephantBlua" ];_x000D_
_x000D_
let resultA = arr.filter( x => wildTest('biRd*', x) );_x000D_
let resultB = arr.filter( x => wildTest('p?g?z', x) );_x000D_
let resultC = arr.filter( x => wildTest('*Blu?', x) );_x000D_
_x000D_
console.log('biRd*',resultA);_x000D_
console.log('p?g?z',resultB);_x000D_
console.log('*Blu?',resultC);
_x000D_
_x000D_
_x000D_

How do I get the App version and build number using Swift?

I made an Extension on Bundle

extension Bundle {

    var appName: String {
        return infoDictionary?["CFBundleName"] as! String
    }

    var bundleId: String {
        return bundleIdentifier!
    }

    var versionNumber: String {
        return infoDictionary?["CFBundleShortVersionString"] as! String 
    }

    var buildNumber: String {
        return infoDictionary?["CFBundleVersion"] as! String
    }

}

and then use it

versionLabel.text = "\(Bundle.main.appName) v \(Bundle.main.versionNumber) (Build \(Bundle.main.buildNumber))"

What is the equivalent of "!=" in Excel VBA?

Try to use <> instead of !=.

SQLSTATE[42000]: Syntax error or access violation: 1064 You have an error in your SQL syntax — PHP — PDO

I've got this exact error, but in my case I was binding values for the LIMIT clause without specifying the type. I'm just dropping this here in case somebody gets this error for the same reason. Without specifying the type LIMIT :limit OFFSET :offset; resulted in LIMIT '10' OFFSET '1'; instead of LIMIT 10 OFFSET 1;. What helps to correct that is the following:

$stmt->bindParam(':limit', intval($limit, 10), \PDO::PARAM_INT);
$stmt->bindParam(':offset', intval($offset, 10), \PDO::PARAM_INT);

How can I increase the cursor speed in terminal?

System Preferences => Keyboard => Key Repeat Rate

What's the difference between JPA and Hibernate?

Some things are too hard to understand without a historical perspective of the language and understanding of the JCP.

Often there are third parties that develop packages that perform a function or fill a gap that are not part of the official JDK. For various reasons that function may become part of the Java JDK through the JCP (Java Community Process)

Hibernate (in 2003) provided a way to abstract SQL and allow developers to think more in terms of persisting objects (ORM). You notify hibernate about your Entity objects and it automatically generates the strategy to persist them. Hibernate provided an implementation to do this and the API to drive the implementation either through XML config or annotations.

The fundamental issue now is that your code becomes tightly coupled with a specific vendor(Hibernate) for what a lot of people thought should be more generic. Hence the need for a generic persistence API.

Meanwhile, the JCP with a lot of input from Hibernate and other ORM tool vendors was developing JSR 220 (Java Specification Request) which resulted in JPA 1.0 (2006) and eventually JSR 317 which is JPA 2.0 (2009). These are specifications of a generic Java Persistence API. The API is provided in the JDK as a set of interfaces so that your classes can depend on the javax.persistence and not worry about the particular vendor that is doing the work of persisting your objects. This is only the API and not the implementation. Hibernate now becomes one of the many vendors that implement the JPA 2.0 specification. You can code toward JPA and pick whatever compliant ORM vendor suits your needs.

There are cases where Hibernate may give you features that are not codified in JPA. In this case, you can choose to insert a Hibernate specific annotation directly in your class since JPA does not provide the interface to do that thing.

Source: http://www.reddit.com/r/java/comments/16ovek/understanding_when_to_use_jpa_vs_hibernate/

NullPointerException: Attempt to invoke virtual method 'boolean java.lang.String.equalsIgnoreCase(java.lang.String)' on a null object reference

The exception occurs due to this statement,

called_from.equalsIgnoreCase("add")

It seem that the previous statement

String called_from = getIntent().getStringExtra("called");

returned a null reference.

You can check whether the intent to start this activity contains such a key "called".

Animate scroll to ID on page load

Pure javascript solution with scrollIntoView() function:

_x000D_
_x000D_
document.getElementById('title1').scrollIntoView({block: 'start', behavior: 'smooth'});
_x000D_
<h2 id="title1">Some title</h2>
_x000D_
_x000D_
_x000D_

P.S. 'smooth' parameter now works from Chrome 61 as julien_c mentioned in the comments.

CSV new-line character seen in unquoted field error

If this happens to you on mac (as it did to me):

  1. Save the file as CSV (MS-DOS Comma-Separated)
  2. Run the following script

    with open(csv_filename, 'rU') as csvfile:
        csvreader = csv.reader(csvfile)
        for row in csvreader:
            print ', '.join(row)
    

Find location of a removable SD card

Like Richard I also use /proc/mounts file to get the list of available storage options

public class StorageUtils {

    private static final String TAG = "StorageUtils";

    public static class StorageInfo {

        public final String path;
        public final boolean internal;
        public final boolean readonly;
        public final int display_number;

        StorageInfo(String path, boolean internal, boolean readonly, int display_number) {
            this.path = path;
            this.internal = internal;
            this.readonly = readonly;
            this.display_number = display_number;
        }

        public String getDisplayName() {
            StringBuilder res = new StringBuilder();
            if (internal) {
                res.append("Internal SD card");
            } else if (display_number > 1) {
                res.append("SD card " + display_number);
            } else {
                res.append("SD card");
            }
            if (readonly) {
                res.append(" (Read only)");
            }
            return res.toString();
        }
    }

    public static List<StorageInfo> getStorageList() {

        List<StorageInfo> list = new ArrayList<StorageInfo>();
        String def_path = Environment.getExternalStorageDirectory().getPath();
        boolean def_path_internal = !Environment.isExternalStorageRemovable();
        String def_path_state = Environment.getExternalStorageState();
        boolean def_path_available = def_path_state.equals(Environment.MEDIA_MOUNTED)
                                    || def_path_state.equals(Environment.MEDIA_MOUNTED_READ_ONLY);
        boolean def_path_readonly = Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED_READ_ONLY);
        BufferedReader buf_reader = null;
        try {
            HashSet<String> paths = new HashSet<String>();
            buf_reader = new BufferedReader(new FileReader("/proc/mounts"));
            String line;
            int cur_display_number = 1;
            Log.d(TAG, "/proc/mounts");
            while ((line = buf_reader.readLine()) != null) {
                Log.d(TAG, line);
                if (line.contains("vfat") || line.contains("/mnt")) {
                    StringTokenizer tokens = new StringTokenizer(line, " ");
                    String unused = tokens.nextToken(); //device
                    String mount_point = tokens.nextToken(); //mount point
                    if (paths.contains(mount_point)) {
                        continue;
                    }
                    unused = tokens.nextToken(); //file system
                    List<String> flags = Arrays.asList(tokens.nextToken().split(",")); //flags
                    boolean readonly = flags.contains("ro");

                    if (mount_point.equals(def_path)) {
                        paths.add(def_path);
                        list.add(0, new StorageInfo(def_path, def_path_internal, readonly, -1));
                    } else if (line.contains("/dev/block/vold")) {
                        if (!line.contains("/mnt/secure")
                            && !line.contains("/mnt/asec")
                            && !line.contains("/mnt/obb")
                            && !line.contains("/dev/mapper")
                            && !line.contains("tmpfs")) {
                            paths.add(mount_point);
                            list.add(new StorageInfo(mount_point, false, readonly, cur_display_number++));
                        }
                    }
                }
            }

            if (!paths.contains(def_path) && def_path_available) {
                list.add(0, new StorageInfo(def_path, def_path_internal, def_path_readonly, -1));
            }

        } catch (FileNotFoundException ex) {
            ex.printStackTrace();
        } catch (IOException ex) {
            ex.printStackTrace();
        } finally {
            if (buf_reader != null) {
                try {
                    buf_reader.close();
                } catch (IOException ex) {}
            }
        }
        return list;
    }    
}

How can I get the last 7 characters of a PHP string?

It would be better to have a check before getting the string.

$newstring = substr($dynamicstring, -7);

if characters are greater then 7 return last 7 characters else return the provided string.

or do this if you need to return message or error if length is less then 7

$newstring = (strlen($dynamicstring)>7)?substr($dynamicstring, -7):"message";

substr documentation

How can you customize the numbers in an ordered list?

Stole a lot of this from other answers, but this is working in FF3 for me. It has upper-roman, uniform indenting, a close bracket.

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<title> new document </title>
<style type="text/css">
<!--
ol {
  counter-reset: item;
  margin-left: 0;
  padding-left: 0;
}
li {
  margin-bottom: .5em;
}
li:before {
  display: inline-block;
  content: counter(item, upper-roman) ")";
  counter-increment: item;
  width: 3em;
}
-->
</style>
</head>

<body>
<ol>
  <li>One</li>
  <li>Two</li>
  <li>Three</li>
  <li>Four</li>
  <li>Five</li>
  <li>Six</li>
  <li>Seven</li>
  <li>Eight</li>
  <li>Nine</li>
  <li>Ten</li>
</ol>
</body>
</html>

What are the obj and bin folders (created by Visual Studio) used for?

I would encourage you to see this youtube video which demonstrates the difference between C# bin and obj folders and also explains how we get the benefit of incremental/conditional compilation.

C# compilation is a two-step process, see the below diagram for more details:

  1. Compiling: In compiling phase individual C# code files are compiled into individual compiled units. These individual compiled code files go in the OBJ directory.
  2. Linking: In the linking phase these individual compiled code files are linked to create single unit DLL and EXE. This goes in the BIN directory.

C# bin vs obj folders

If you compare both bin and obj directory you will find greater number of files in the "obj" directory as it has individual compiled code files while "bin" has a single unit.

bin vs obj

Update style of a component onScroll in React.js

To expand on @Austin's answer, you should add this.handleScroll = this.handleScroll.bind(this) to your constructor:

constructor(props){
    this.handleScroll = this.handleScroll.bind(this)
}
componentDidMount: function() {
    window.addEventListener('scroll', this.handleScroll);
},

componentWillUnmount: function() {
    window.removeEventListener('scroll', this.handleScroll);
},

handleScroll: function(event) {
    let scrollTop = event.srcElement.body.scrollTop,
        itemTranslate = Math.min(0, scrollTop/3 - 60);

    this.setState({
      transform: itemTranslate
    });
},
...

This gives handleScroll() access to the proper scope when called from the event listener.

Also be aware you cannot do the .bind(this) in the addEventListener or removeEventListener methods because they will each return references to different functions and the event will not be removed when the component unmounts.

Javascript querySelector vs. getElementById

"Better" is subjective.

querySelector is the newer feature.

getElementById is better supported than querySelector.

querySelector is better supported than getElementsByClassName.

querySelector lets you find elements with rules that can't be expressed with getElementById and getElementsByClassName

You need to pick the appropriate tool for any given task.

(In the above, for querySelector read querySelector / querySelectorAll).

Java FileReader encoding issue

FileReader uses Java's platform default encoding, which depends on the system settings of the computer it's running on and is generally the most popular encoding among users in that locale.

If this "best guess" is not correct then you have to specify the encoding explicitly. Unfortunately, FileReader does not allow this (major oversight in the API). Instead, you have to use new InputStreamReader(new FileInputStream(filePath), encoding) and ideally get the encoding from metadata about the file.

Execute a shell function with timeout

You can create a function which would allow you to do the same as timeout but also for other functions:

function run_cmd { 
    cmd="$1"; timeout="$2";
    grep -qP '^\d+$' <<< $timeout || timeout=10

    ( 
        eval "$cmd" &
        child=$!
        trap -- "" SIGTERM 
        (       
                sleep $timeout
                kill $child 2> /dev/null 
        ) &     
        wait $child
    )
}

And could run as below:

run_cmd "echoFooBar" 10

Note: The solution came from one of my questions: Elegant solution to implement timeout for bash commands and functions

Force unmount of NFS-mounted directory

Your NFS server disappeared.

Ideally your best bet is if the NFS server comes back.

If not, the "umount -f" should have done the trick. It doesn't ALWAYS work, but it often will.

If you happen to know what processes are USING the NFS filesystem, you could try killing those processes and then maybe an unmount would work.

Finally, I'd guess you need to reboot.

Also, DON'T soft-mount your NFS drives. You use hard-mounts to guarantee that they worked. That's necessary if you're doing writes.

"Application tried to present modally an active controller"?

I had same problem.I solve it. You can try This code:

[tabBarController setSelectedIndex:1];
[self dismissModalViewControllerAnimated:YES];

How to avoid the "Circular view path" exception with Spring MVC test

Another simple approach:

package org.yourpackagename;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.builder.SpringApplicationBuilder;
import org.springframework.boot.context.web.SpringBootServletInitializer;

@SpringBootApplication
public class Application extends SpringBootServletInitializer {

      @Override
        protected SpringApplicationBuilder configure(SpringApplicationBuilder application) {
            return application.sources(PreferenceController.class);
        }


    public static void main(String[] args) {
        SpringApplication.run(PreferenceController.class, args);
    }
}

How to solve privileges issues when restore PostgreSQL Database

For people who have narrowed down the issue to the COMMENT ON statements (as per various answers below) and who have superuser access to the source database from which the dump file is created, the simplest solution might be to prevent the comments from being included to the dump file in the first place, by removing them from the source database being dumped...

COMMENT ON EXTENSION postgis IS NULL;
COMMENT ON EXTENSION plpgsql IS NULL;
COMMENT ON SCHEMA public IS NULL;

Future dumps then won't include the COMMENT ON statements.

Export and import table dump (.sql) using pgAdmin

  1. In pgAdmin, select the required target schema in object tree (databases->your_db_name->schemas->your_target_schema)
  2. Click on Plugins/PSQL Console (in top-bar)
  3. Write \i /path/to/yourfile.sql
  4. Press enter

Is an HTTPS query string secure?

I don't agree with the statement about [...] HTTP referrer leakage (an external image in the target page might leak the password) in Slough's response.

The HTTP 1.1 RFC explicitly states:

Clients SHOULD NOT include a Referer header field in a (non-secure) HTTP request if the referring page was transferred with a secure protocol.

Anyway, server logs and browser history are more than sufficient reasons not to put sensitive data in the query string.

What is the ultimate postal code and zip regex?

If someone is still interested in how to validate zip codes I've found a solution:

Using Google Geocoding API we can check validity of ZIP code having both Country code and a ZIP code itself.

For example I live in Ukraine so I can check like this: https://maps.googleapis.com/maps/api/geocode/json?components=postal_code:80380|country:UA

Or using JS API: https://developers.google.com/maps/documentation/javascript/geocoding#ComponentFiltering

Where 80380 is valid ZIP for Ukraine, actually every (#####) is valid.

Google returns ZERO_RESULTS status if nothing found. Or OK and a result if both are correct.

Hope this will be helpful.

make iframe height dynamic based on content inside- JQUERY/Javascript

A slightly improved answer to BlueFish...

function resizeIframe(iframe) {
    var padding = 50;
    if (iframe.contentWindow.document.body.scrollHeight < (window.innerHeight - padding))
        iframe.height = iframe.contentWindow.document.body.scrollHeight + "px";
    else
        iframe.height = (window.innerHeight - padding) + "px";
}

This takes in consideration the height of the windows screen(browser, phone) which is good for responsive design and iframes that have huge height. Padding represents the padding you want above and below the iframe in the case it goes trough whole screen.

Saving image to file

You can save image , save the file in your current directory application and move the file to any directory .

 Bitmap btm = new Bitmap(image.width,image.height);
    Image img = btm;
                        img.Save(@"img_" + x + ".jpg", System.Drawing.Imaging.ImageFormat.Jpeg);
                        FileInfo img__ = new FileInfo(@"img_" + x + ".jpg");
                        img__.MoveTo("myVideo\\img_" + x + ".jpg");

Failed to resolve: com.android.support:appcompat-v7:27.+ (Dependency Error)

If you are using Android Studio 3.0 or above make sure your project build.gradle should have content similar to-

buildscript {                 
    repositories {
        google()
        jcenter()
    }
    dependencies {            
        classpath 'com.android.tools.build:gradle:3.0.1'

    }
}

allprojects {
    repositories {
        google()
        jcenter()
    }
}

Note- position really matters add google() before jcenter()

And for below Android Studio 3.0 and starting from support libraries 26.+ your project build.gradle must look like this-

allprojects {
    repositories {
        jcenter()
        maven {
            url "https://maven.google.com"
        }
    }
}

check these links below for more details-

1- Building Android Apps

2- Add Build Dependencies

3- Configure Your Build

Heatmap in matplotlib with pcolor?

This is late, but here is my python implementation of the flowingdata NBA heatmap.

updated:1/4/2014: thanks everyone

# -*- coding: utf-8 -*-
# <nbformat>3.0</nbformat>

# ------------------------------------------------------------------------
# Filename   : heatmap.py
# Date       : 2013-04-19
# Updated    : 2014-01-04
# Author     : @LotzJoe >> Joe Lotz
# Description: My attempt at reproducing the FlowingData graphic in Python
# Source     : http://flowingdata.com/2010/01/21/how-to-make-a-heatmap-a-quick-and-easy-solution/
#
# Other Links:
#     http://stackoverflow.com/questions/14391959/heatmap-in-matplotlib-with-pcolor
#
# ------------------------------------------------------------------------

import matplotlib.pyplot as plt
import pandas as pd
from urllib2 import urlopen
import numpy as np
%pylab inline

page = urlopen("http://datasets.flowingdata.com/ppg2008.csv")
nba = pd.read_csv(page, index_col=0)

# Normalize data columns
nba_norm = (nba - nba.mean()) / (nba.max() - nba.min())

# Sort data according to Points, lowest to highest
# This was just a design choice made by Yau
# inplace=False (default) ->thanks SO user d1337
nba_sort = nba_norm.sort('PTS', ascending=True)

nba_sort['PTS'].head(10)

# Plot it out
fig, ax = plt.subplots()
heatmap = ax.pcolor(nba_sort, cmap=plt.cm.Blues, alpha=0.8)

# Format
fig = plt.gcf()
fig.set_size_inches(8, 11)

# turn off the frame
ax.set_frame_on(False)

# put the major ticks at the middle of each cell
ax.set_yticks(np.arange(nba_sort.shape[0]) + 0.5, minor=False)
ax.set_xticks(np.arange(nba_sort.shape[1]) + 0.5, minor=False)

# want a more natural, table-like display
ax.invert_yaxis()
ax.xaxis.tick_top()

# Set the labels

# label source:https://en.wikipedia.org/wiki/Basketball_statistics
labels = [
    'Games', 'Minutes', 'Points', 'Field goals made', 'Field goal attempts', 'Field goal percentage', 'Free throws made', 'Free throws attempts', 'Free throws percentage',
    'Three-pointers made', 'Three-point attempt', 'Three-point percentage', 'Offensive rebounds', 'Defensive rebounds', 'Total rebounds', 'Assists', 'Steals', 'Blocks', 'Turnover', 'Personal foul']

# note I could have used nba_sort.columns but made "labels" instead
ax.set_xticklabels(labels, minor=False)
ax.set_yticklabels(nba_sort.index, minor=False)

# rotate the
plt.xticks(rotation=90)

ax.grid(False)

# Turn off all the ticks
ax = plt.gca()

for t in ax.xaxis.get_major_ticks():
    t.tick1On = False
    t.tick2On = False
for t in ax.yaxis.get_major_ticks():
    t.tick1On = False
    t.tick2On = False

The output looks like this: flowingdata-like nba heatmap

There's an ipython notebook with all this code here. I've learned a lot from 'overflow so hopefully someone will find this useful.

Difference between using Throwable and Exception in a try catch

Thowable catches really everything even ThreadDeath which gets thrown by default to stop a thread from the now deprecated Thread.stop() method. So by catching Throwable you can be sure that you'll never leave the try block without at least going through your catch block, but you should be prepared to also handle OutOfMemoryError and InternalError or StackOverflowError.

Catching Throwable is most useful for outer server loops that delegate all sorts of requests to outside code but may itself never terminate to keep the service alive.

How to set up a cron job to run an executable every hour?

use

path_to_exe >> log_file

to see the output of your command also errors can be redirected with

path_to_exe &> log_file

also you can use

crontab -l

to check if your edits were saved.

Pass a simple string from controller to a view MVC3

Use ViewBag

ViewBag.MyString = "some string";
return View();

In your View

<h1>@ViewBag.MyString</h1>

I know this does not answer your question (it has already been answered), but the title of your question is very vast and can bring any person on this page who is searching for a query for passing a simple string to View from Controller.

How to post an array of complex objects with JSON, jQuery to ASP.NET MVC Controller?

Action Filters, jquery stringify, bleh...

Peter, this functionality is native to MVC. That's one of things that makes MVC so great.

$.post('SomeController/Batch', { 'ids': ['1', '2', '3']}, function (r) {
   ...
});

And in the action,

[HttpPost]
public ActionResult Batch(string[] ids)
{
}

Works like a charm:

enter image description here

If you're using jQuery 1.4+, then you want to look into setting traditional mode:

jQuery.ajaxSettings.traditional = true;

As described here: http://www.dovetailsoftware.com/blogs/kmiller/archive/2010/02/24/jquery-1-4-breaks-asp-net-mvc-actions-with-array-parameters

This even works for complex objects. If you're interested, you should look into the MVC documentation about Model Binding: http://msdn.microsoft.com/en-us/library/dd410405.aspx

Return anonymous type results?

In C# 7 you can now use tuples!... which eliminates the need to create a class just to return the result.

Here is a sample code:

public List<(string Name, string BreedName)> GetDogsWithBreedNames()
{
    var db = new DogDataContext(ConnectString);
    var result = from d in db.Dogs
             join b in db.Breeds on d.BreedId equals b.BreedId
             select new
             {
                Name = d.Name,
                BreedName = b.BreedName
             }.ToList();

    return result.Select(r => (r.Name, r.BreedName)).ToList();
}

You might need to install System.ValueTuple nuget package though.