Programs & Examples On #Luajit

LuaJIT is a Just-In-Time Compiler for the Lua programming language. LuaJIT offers more performance, at the expense of portability. On the supported OS's (all popular operating systems based on x86 or x64 CPUs (Windows, Mac OSX, Linux, ...), ARM based embedded devices (Android, iOS) and PPC/e500v2 CPUs) it offers an API- and ABI-compatible drop-in replacement for the standard Lua interpreter.

Insert at first position of a list in Python

From the documentation:

list.insert(i, x)
Insert an item at a given position. The first argument is the index of the element before which to insert, so a.insert(0, x) inserts at the front of the list, and a.insert(len(a),x) is equivalent to a.append(x)

http://docs.python.org/2/tutorial/datastructures.html#more-on-lists

Drop shadow on a div container?

.shadow {
    -moz-box-shadow:    3px 3px 5px 6px #ccc;
    -webkit-box-shadow: 3px 3px 5px 6px #ccc;
    box-shadow:         3px 3px 5px 6px #ccc;
}

PHP Checking if the current date is before or after a set date

if (strtotime($date) > mktime(0,0,0)) should do the job.

How to reload a div without reloading the entire page?

jQuery.load() is probably the easiest way to load data asynchronously using a selector, but you can also use any of the jquery ajax methods (get, post, getJSON, ajax, etc.)

Note that load allows you to use a selector to specify what piece of the loaded script you want to load, as in

$("#mydiv").load(location.href + " #mydiv");

Note that this technically does load the whole page and jquery removes everything but what you have selected, but that's all done internally.

Sum of Numbers C++

mystycs, you are using the variable i to control your loop, however you are editing the value of i within the loop:

for (int i=0; i < positiveInteger; i++)
{
    i = startingNumber + 1;
    cout << i;
}

Try this instead:

int sum = 0;

for (int i=0; i < positiveInteger; i++)
{
    sum = sum + i;
    cout << sum << " " << i;
}

How to get subarray from array?

The question is actually asking for a New array, so I believe a better solution would be to combine Abdennour TOUMI's answer with a clone function:

_x000D_
_x000D_
function clone(obj) {_x000D_
  if (null == obj || "object" != typeof obj) return obj;_x000D_
  const copy = obj.constructor();_x000D_
  for (const attr in obj) {_x000D_
    if (obj.hasOwnProperty(attr)) copy[attr] = obj[attr];_x000D_
  }_x000D_
  return copy;_x000D_
}_x000D_
_x000D_
// With the `clone()` function, you can now do the following:_x000D_
_x000D_
Array.prototype.subarray = function(start, end) {_x000D_
  if (!end) {_x000D_
    end = this.length;_x000D_
  } _x000D_
  const newArray = clone(this);_x000D_
  return newArray.slice(start, end);_x000D_
};_x000D_
_x000D_
// Without a copy you will lose your original array._x000D_
_x000D_
// **Example:**_x000D_
_x000D_
const array = [1, 2, 3, 4, 5];_x000D_
console.log(array.subarray(2)); // print the subarray [3, 4, 5, subarray: function]_x000D_
_x000D_
console.log(array); // print the original array [1, 2, 3, 4, 5, subarray: function]
_x000D_
_x000D_
_x000D_

[http://stackoverflow.com/questions/728360/most-elegant-way-to-clone-a-javascript-object]

How to get process ID of background process?

this is what I have done. Check it out, hope it can help.

#!/bin/bash
#
# So something to show.
echo "UNO" >  UNO.txt
echo "DOS" >  DOS.txt
#
# Initialize Pid List
dPidLst=""
#
# Generate background processes
tail -f UNO.txt&
dPidLst="$dPidLst $!"
tail -f DOS.txt&
dPidLst="$dPidLst $!"
#
# Report process IDs
echo PID=$$
echo dPidLst=$dPidLst
#
# Show process on current shell
ps -f
#
# Start killing background processes from list
for dPid in $dPidLst
do
        echo killing $dPid. Process is still there.
        ps | grep $dPid
        kill $dPid
        ps | grep $dPid
        echo Just ran "'"ps"'" command, $dPid must not show again.
done

Then just run it as: ./bgkill.sh with proper permissions of course

root@umsstd22 [P]:~# ./bgkill.sh
PID=23757
dPidLst= 23758 23759
UNO
DOS
UID        PID  PPID  C STIME TTY          TIME CMD
root      3937  3935  0 11:07 pts/5    00:00:00 -bash
root     23757  3937  0 11:55 pts/5    00:00:00 /bin/bash ./bgkill.sh
root     23758 23757  0 11:55 pts/5    00:00:00 tail -f UNO.txt
root     23759 23757  0 11:55 pts/5    00:00:00 tail -f DOS.txt
root     23760 23757  0 11:55 pts/5    00:00:00 ps -f
killing 23758. Process is still there.
23758 pts/5    00:00:00 tail
./bgkill.sh: line 24: 23758 Terminated              tail -f UNO.txt
Just ran 'ps' command, 23758 must not show again.
killing 23759. Process is still there.
23759 pts/5    00:00:00 tail
./bgkill.sh: line 24: 23759 Terminated              tail -f DOS.txt
Just ran 'ps' command, 23759 must not show again.
root@umsstd22 [P]:~# ps -f
UID        PID  PPID  C STIME TTY          TIME CMD
root      3937  3935  0 11:07 pts/5    00:00:00 -bash
root     24200  3937  0 11:56 pts/5    00:00:00 ps -f

What is Node.js?

V8 is an implementation of JavaScript. It lets you run standalone JavaScript applications (among other things).

Node.js is simply a library written for V8 which does evented I/O. This concept is a bit trickier to explain, and I'm sure someone will answer with a better explanation than I... The gist is that rather than doing some input or output and waiting for it to happen, you just don't wait for it to finish. So for example, ask for the last edited time of a file:

// Pseudo code
stat( 'somefile' )

That might take a couple of milliseconds, or it might take seconds. With evented I/O you simply fire off the request and instead of waiting around you attach a callback that gets run when the request finishes:

// Pseudo code
stat( 'somefile', function( result ) {
  // Use the result here
} );
// ...more code here

This makes it a lot like JavaScript code in the browser (for example, with Ajax style functionality).

For more information, you should check out the article Node.js is genuinely exciting which was my introduction to the library/platform... I found it quite good.

What is the difference between `Enum.name()` and `Enum.toString()`?

Use toString when you need to display the name to the user.

Use name when you need the name for your program itself, e.g. to identify and differentiate between different enum values.

How to open a file for both reading and writing?

Summarize the I/O behaviors

|          Mode          |  r   |  r+  |  w   |  w+  |  a   |  a+  |
| :--------------------: | :--: | :--: | :--: | :--: | :--: | :--: |
|          Read          |  +   |  +   |      |  +   |      |  +   |
|         Write          |      |  +   |  +   |  +   |  +   |  +   |
|         Create         |      |      |  +   |  +   |  +   |  +   |
|         Cover          |      |      |  +   |  +   |      |      |
| Point in the beginning |  +   |  +   |  +   |  +   |      |      |
|    Point in the end    |      |      |      |      |  +   |  +   |

and the decision branch

enter image description here

setup android on eclipse but don't know SDK directory

The Android SDK directory is just the folder you get after uncompressing one of these files:

http://developer.android.com/sdk/index.html

There's no such "SDK installation"... may be, what you installed was the ADT plugin (which does not include the SDK). You have to download one of the ZIP files you find in the link above, uncompress it and boila! you have the SDK Folder.

How do I implement Toastr JS?

I investigate i knew that the jquery script need to load in order that why it not worked in your case. Because $ symbol mentioned in code not understand unless you load Jquery 1.9.1 at first. Load like follows

<script src="http://code.jquery.com/jquery-1.9.1.min.js"></script>
<script src="http://code.jquery.com/jquery-migrate-1.2.1.min.js"></script>
<link href="https://cdnjs.cloudflare.com/ajax/libs/toastr.js/2.0.1/css/toastr.css" rel="stylesheet"/>
<script src="https://cdnjs.cloudflare.com/ajax/libs/toastr.js/2.0.1/js/toastr.js"></script>

Then it will work fine

WCF Exception: Could not find a base address that matches scheme http for the endpoint

Open IIS And right click on Default App Pool and Add Binding to make application work with HTTPS protocol.

type : https

IP address : All unassigned

port no : 443

SSL Certificate : WMSVC

then

Click on and restart IIS

Done

Does mobile Google Chrome support browser extensions?

Extensions are not supported, see: https://developers.google.com/chrome/mobile/docs/faq .

Specifically:

Does Chrome for Android now support the embedded WebView for a hybrid native/web app?

A Chrome-based WebView is included in Android 4.4 (KitKat) and later. See the WebView overview for details.

Does Chrome for Android support apps and extensions?

Chrome apps and extensions are currently not supported on Chrome for Android. We have no plans to announce at this time.

Can I write and deploy web apps on Chrome for Android?

Though Chrome apps are not currently supported, we would love to see great interactive web sites accessible by URL.

How to use PHP OPCache?

I am going to drop in my two cents for what I use opcache.

I have made an extensive framework with a lot of fields and validation methods and enums to be able to talk to my database.

Without opcache

When using this script without opcache and I push 9000 requests in 2.8 seconds to the apache server it maxes out at 90-100% cpu for 70-80 seconds until it catches up with all the requests.

Total time taken: 76085 milliseconds(76 seconds)

With opcache enabled

With opcache enabled it runs at 25-30% cpu time for about 25 seconds and never passes 25% cpu use.

Total time taken: 26490 milliseconds(26 seconds)

I have made an opcache blacklist file to disable the caching of everything except the framework which is all static and doesnt need changing of functionality. I choose explicitly for just the framework files so that I could develop without worrying about reloading/validating the cache files. Having everything cached saves a second on the total of the requests 25546 milliseconds

This significantly expands the amount of data/requests I can handle per second without the server even breaking a sweat.

try/catch blocks with async/await

A cleaner alternative would be the following:

Due to the fact that every async function is technically a promise

You can add catches to functions when calling them with await

async function a(){
    let error;

    // log the error on the parent
    await b().catch((err)=>console.log('b.failed'))

    // change an error variable
    await c().catch((err)=>{error=true; console.log(err)})

    // return whatever you want
    return error ? d() : null;
}
a().catch(()=>console.log('main program failed'))

No need for try catch, as all promises errors are handled, and you have no code errors, you can omit that in the parent!!

Lets say you are working with mongodb, if there is an error you might prefer to handle it in the function calling it than making wrappers, or using try catches.

Set the selected index of a Dropdown using jQuery

I'm writing this answer in 2015, and for some reason (probably older versions of jQuery) none of the other answers have worked for me. I mean, they change the selected index, but it doesn't actually reflect on the actual dropdown.

Here is another way to change the index, and actually have it reflect in the dropdown:

$('#mydropdown').val('first').change();

How do I post form data with fetch api?

?These can help you:

let formData = new FormData();
            formData.append("name", "John");
            formData.append("password", "John123");
            fetch("https://yourwebhook", {
              method: "POST",
              mode: "no-cors",
              cache: "no-cache",
              credentials: "same-origin",
              headers: {
                "Content-Type": "form-data"
              },
              body: formData
            });
            //router.push("/registro-completado");
          } else {
            // doc.data() will be undefined in this case
            console.log("No such document!");
          }
        })
        .catch(function(error) {
          console.log("Error getting document:", error);
        });

Simple way to measure cell execution time in ipython notebook

This is not exactly beautiful but without extra software

class timeit():
    from datetime import datetime
    def __enter__(self):
        self.tic = self.datetime.now()
    def __exit__(self, *args, **kwargs):
        print('runtime: {}'.format(self.datetime.now() - self.tic))

Then you can run it like:

with timeit():
    # your code, e.g., 
    print(sum(range(int(1e7))))

% 49999995000000
% runtime: 0:00:00.338492

Getting result of dynamic SQL into a variable for sql-server

 vMYQUERY := 'SELECT COUNT(*) FROM ALL_OBJECTS WHERE OWNER = UPPER(''MFI_IDBI2LIVE'') AND OBJECT_TYPE = ''TABLE'' 
    AND OBJECT_NAME  =''' || vTBL_CLIENT_MASTER || '''';
    PRINT_STRING(VMYQUERY);
    EXECUTE IMMEDIATE  vMYQUERY INTO VCOUNTTEMP ;

Detecting attribute change of value of an attribute I made

You would have to watch the DOM node changes. There is an API called MutationObserver, but it looks like the support for it is very limited. This SO answer has a link to the status of the API, but it seems like there is no support for it in IE or Opera so far.

One way you could get around this problem is to have the part of the code that modifies the data-select-content-val attribute dispatch an event that you can listen to.

For example, see: http://jsbin.com/arucuc/3/edit on how to tie it together.

The code here is

$(function() {  
  // Here you register for the event and do whatever you need to do.
  $(document).on('data-attribute-changed', function() {
    var data = $('#contains-data').data('mydata');
    alert('Data changed to: ' + data);
  });

  $('#button').click(function() {
    $('#contains-data').data('mydata', 'foo');
    // Whenever you change the attribute you will user the .trigger
    // method. The name of the event is arbitrary
    $(document).trigger('data-attribute-changed');
  });

   $('#getbutton').click(function() {
    var data = $('#contains-data').data('mydata');
    alert('Data is: ' + data);
  });
});

How to clean old dependencies from maven repositories?

Short answer - Deleted .m2 folder in {user.home}. E.g. in windows 10 user home is C:\Users\user1. Re-build your project using mvn clean package. Only those dependencies would remain, which are required by the projects.

Long Answer - .m2 folder is just like a normal folder and the content of the folder is built from different projects. I think there is no way to figure out automatically that which library is "old". In fact old is a vague word. There could be so many reasons when a previous version of a library is used in a project, hence determining which one is unused is not possible.

All you could do, is to delete the .m2 folder and re-build all of your projects and then the folder would automatically build with all the required library.

If you are concern about only a particular version of a library to be used in all the projects; it is important that the project's pom should also update to latest version. i.e. if different POMs refer different versions of the library, all will get downloaded in .m2.

"Unable to locate tools.jar" when running ant

  1. Try to check it once more according to this tutorial: http://vietpad.sourceforge.net/javaonwindows.html

  2. Try to reboot your system.

  3. If nothing, try to run "cmd" and type there "java", does it print anything?

Why is the GETDATE() an invalid identifier

Use ORACLE equivalent of getdate() which is sysdate . Read about here. Getdate() belongs to SQL Server , will not work on Oracle.

Other option is current_date

How do I escape double and single quotes in sed?

May be the "\" char, try this one:

sed 's/\"http:\/\/www.fubar.com\"/URL_FUBAR/g'

Angular and Typescript: Can't find names - Error: cannot find name

When having Typescript >= 2 the "lib" option in tsconfig.json will do the job. No need for Typings. https://www.typescriptlang.org/docs/handbook/compiler-options.html

{
    "compilerOptions": {
        "target": "es5",
        "lib": ["es2016", "dom"] //or es6 instead of es2016(es7)
    }
}

How can I loop through a C++ map of maps?

As einpoklum mentioned in their answer, since C++17 you can also use structured binding declarations. I want to extend on that by providing a full solution for iterating over a map of maps in a comfortable way:

int main() {
    std::map<std::string, std::map<std::string, std::string>> m {
        {"name1", {{"value1", "data1"}, {"value2", "data2"}}},
        {"name2", {{"value1", "data1"}, {"value2", "data2"}}},
        {"name3", {{"value1", "data1"}, {"value2", "data2"}}}
    };

    for (const auto& [k1, v1] : m)
        for (const auto& [k2, v2] : v1)
            std::cout << "m[" << k1 << "][" << k2 << "]=" << v2 << std::endl;

    return 0;
}

Note 1: For filling the map, I used an initializer list (which is a C++11 feature). This can sometimes be handy to keep fixed initializations compact.

Note 2: If you want to modify the map m within the loops, you have to remove the const keywords.

Code on Coliru

How to assign an action for UIImageView object in Swift

You can put a UIButton with a transparent background over top of the UIImageView, and listen for a tap on the button before loading the image

How to add Action bar options menu in Android Fragments

You need to call setHasOptionsMenu(true) in onCreate().

For backwards compatibility it's better to place this call as late as possible at the end of onCreate() or even later in onActivityCreated() or something like that.

See: https://developer.android.com/reference/android/app/Fragment.html#setHasOptionsMenu(boolean)

Laravel migration: unique key is too long, even if specified

i had same problem and i am using a wamp

Solution : Open file : config/database.php

'engine' => null, => 'engine' => 'InnoDB',

Thanks

What are unit tests, integration tests, smoke tests, and regression tests?

  • Integration testing: Integration testing is the integrate another element
  • Smoke testing: Smoke testing is also known as build version testing. Smoke testing is the initial testing process exercised to check whether the software under test is ready/stable for further testing.
  • Regression testing: Regression testing is repeated testing. Whether new software is effected in another module or not.
  • Unit testing: It is a white box testing. Only developers involve in it

Difference between del, remove, and pop on lists

Many best explanations are here but I will try my best to simplify more.

Among all these methods, remove & pop are postfix while delete is prefix.

remove(): It used to remove first occurrence of element

remove(i) => first occurrence of i value

>>> a = [0, 2, 3, 2, 1, 4, 6, 5, 7]
>>> a.remove(2)   # where i = 2
>>> a
[0, 3, 2, 1, 4, 6, 5, 7]

pop(): It used to remove element if:

unspecified

pop() => from end of list

>>>a.pop()
>>>a
[0, 3, 2, 1, 4, 6, 5]

specified

pop(index) => of index

>>>a.pop(2)
>>>a
[0, 3, 1, 4, 6, 5]

WARNING: Dangerous Method Ahead

delete(): Its a prefix method.

Keep an eye on two different syntax for same method: [] and (). It possesses power to:

1.Delete index

del a[index] => used to delete index and its associated value just like pop.

>>>del a[1]
>>>a
[0, 1, 4, 6, 5]

2.Delete values in range [index 1:index N]

del a[0:3] => multiple values in range

>>>del a[0:3]
>>>a
[6, 5]

3.Last but not list, to delete whole list in one shot

del (a) => as said above.

>>>del (a)
>>>a

Hope this clarifies the confusion if any.

HintPath vs ReferencePath in Visual Studio

My own experience has been that it's best to stick to one of two kinds of assembly references:

  • A 'local' assembly in the current build directory
  • An assembly in the GAC

I've found (much like you've described) other methods to either be too easily broken or have annoying maintenance requirements.

Any assembly I don't want to GAC, has to live in the execution directory. Any assembly that isn't or can't be in the execution directory I GAC (managed by automatic build events).

This hasn't given me any problems so far. While I'm sure there's a situation where it won't work, the usual answer to any problem has been "oh, just GAC it!". 8 D

Hope that helps!

jquery how to empty input field

While submitting form use reset method on form. The reset() method resets the values of all elements in a form.

$('#form-id')[0].reset();

OR 

document.getElementById("form-id").reset();

https://developer.mozilla.org/en-US/docs/Web/API/HTMLFormElement/reset

_x000D_
_x000D_
$("#submit-button").on("click", function(){_x000D_
       //code here_x000D_
       $('#form-id')[0].reset();_x000D_
});
_x000D_
<html>_x000D_
<head>_x000D_
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.1.1/jquery.min.js"></script>_x000D_
</head>_x000D_
<body>_x000D_
<form id="form-id">_x000D_
  First name:<br>_x000D_
  <input type="text" name="firstname">_x000D_
  <br>_x000D_
  Last name:<br>_x000D_
  <input type="text" name="lastname">_x000D_
  <br><br>_x000D_
  <input id="submit-button" type="submit" value="Submit">_x000D_
</form> _x000D_
</body>_x000D_
</html>
_x000D_
_x000D_
_x000D_

Tooltip with HTML content without JavaScript

Pure CSS:

_x000D_
_x000D_
.app-tooltip {_x000D_
  position: relative;_x000D_
}_x000D_
_x000D_
.app-tooltip:before {_x000D_
  content: attr(data-title);_x000D_
  background-color: rgba(97, 97, 97, 0.9);_x000D_
  color: #fff;_x000D_
  font-size: 12px;_x000D_
  padding: 10px;_x000D_
  position: absolute;_x000D_
  bottom: -50px;_x000D_
  opacity: 0;_x000D_
  transition: all 0.4s ease;_x000D_
  font-weight: 500;_x000D_
  z-index: 2;_x000D_
}_x000D_
_x000D_
.app-tooltip:after {_x000D_
  content: '';_x000D_
  position: absolute;_x000D_
  opacity: 0;_x000D_
  left: 5px;_x000D_
  bottom: -16px;_x000D_
  border-style: solid;_x000D_
  border-width: 0 10px 10px 10px;_x000D_
  border-color: transparent transparent rgba(97, 97, 97, 0.9) transparent;_x000D_
  transition: all 0.4s ease;_x000D_
}_x000D_
_x000D_
.app-tooltip:hover:after,_x000D_
.app-tooltip:hover:before {_x000D_
  opacity: 1;_x000D_
}
_x000D_
<div href="#" class="app-tooltip" data-title="Your message here"> Test here</div>
_x000D_
_x000D_
_x000D_

What's the difference between console.dir and console.log?

I think Firebug does it differently than Chrome's dev tools. It looks like Firebug gives you a stringified version of the object while console.dir gives you an expandable object. Both give you the expandable object in Chrome, and I think that's where the confusion might come from. Or it's just a bug in Chrome.

In Chrome, both do the same thing. Expanding on your test, I have noticed that Chrome gets the current value of the object when you expand it.

> o = { foo: 1 }
> console.log(o)
Expand now, o.foo = 1
> o.foo = 2
o.foo is still displayed as 1 from previous lines

> o = { foo: 1 }
> console.log(o)
> o.foo = 2
Expand now, o.foo = 2

You can use the following to get a stringified version of an object if that's what you want to see. This will show you what the object is at the time this line is called, not when you expand it.

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

How to create a laravel hashed password

Compare password in laravel and lumen:

This may be possible that bcrypt function does not work with php7 then you can use below code in laravel and lumen as per your requirements:

use Illuminate\Support\Facades\Hash;

$test = app('hash')->make("test");
if (Hash::check('test', $test)) {
   echo "matched";
} else {
   echo "no matched";
}

I hope, this help will make you happy :)

What can cause a “Resource temporarily unavailable” on sock send() command

Let'e me give an example:

  1. client connect to server, and send 1MB data to server every 1 second.

  2. server side accept a connection, and then sleep 20 second, without recv msg from client.So the tcp send buffer in the client side will be full.

Code in client side:

#include <arpa/inet.h>
#include <sys/socket.h>
#include <stdio.h>
#include <errno.h>
#include <fcntl.h>
#include <stdlib.h>
#include <string.h>
#define exit_if(r, ...)                                                                          \
    if (r) {                                                                                     \
        printf(__VA_ARGS__);                                                                     \
        printf("%s:%d error no: %d error msg %s\n", __FILE__, __LINE__, errno, strerror(errno)); \
        exit(1);                                                                                 \
    }

void setNonBlock(int fd) {
    int flags = fcntl(fd, F_GETFL, 0);
    exit_if(flags < 0, "fcntl failed");
    int r = fcntl(fd, F_SETFL, flags | O_NONBLOCK);
    exit_if(r < 0, "fcntl failed");
}

void test_full_sock_buf_1(){
    short port = 8000;
    struct sockaddr_in addr;
    memset(&addr, 0, sizeof addr);
    addr.sin_family = AF_INET;
    addr.sin_port = htons(port);
    addr.sin_addr.s_addr = INADDR_ANY;


    int fd = socket(AF_INET, SOCK_STREAM, 0);
    exit_if(fd<0, "create socket error");

    int ret = connect(fd, (struct sockaddr *) &addr, sizeof(struct sockaddr));
    exit_if(ret<0, "connect to server error");
    setNonBlock(fd);

    printf("connect to server success");

    const int LEN = 1024 * 1000;
    char msg[LEN];  // 1MB data
    memset(msg, 'a', LEN);

    for (int i = 0; i < 1000; ++i) {
        int len = send(fd, msg, LEN, 0);
        printf("send: %d, erron: %d, %s \n", len, errno, strerror(errno));
        sleep(1);
    }

}

int main(){
    test_full_sock_buf_1();

    return 0;
}

Code in server side:

    #include <arpa/inet.h>
    #include <sys/socket.h>
    #include <stdio.h>
    #include <errno.h>
    #include <fcntl.h>
    #include <stdlib.h>
    #include <string.h>
    #define exit_if(r, ...)                                                                          \
        if (r) {                                                                                     \
            printf(__VA_ARGS__);                                                                     \
            printf("%s:%d error no: %d error msg %s\n", __FILE__, __LINE__, errno, strerror(errno)); \
            exit(1);                                                                                 \
        }
void test_full_sock_buf_1(){

    int listenfd = socket(AF_INET, SOCK_STREAM, 0);
    exit_if(listenfd<0, "create socket error");

    short port = 8000;
    struct sockaddr_in addr;
    memset(&addr, 0, sizeof addr);
    addr.sin_family = AF_INET;
    addr.sin_port = htons(port);
    addr.sin_addr.s_addr = INADDR_ANY;

    int r = ::bind(listenfd, (struct sockaddr *) &addr, sizeof(struct sockaddr));
    exit_if(r<0, "bind socket error");

    r = listen(listenfd, 100);
    exit_if(r<0, "listen socket error");

    struct sockaddr_in raddr;
    socklen_t rsz = sizeof(raddr);
    int cfd = accept(listenfd, (struct sockaddr *) &raddr, &rsz);
    exit_if(cfd<0, "accept socket error");

    sockaddr_in peer;
    socklen_t alen = sizeof(peer);
    getpeername(cfd, (sockaddr *) &peer, &alen);

    printf("accept a connection from %s:%d\n", inet_ntoa(peer.sin_addr), ntohs(peer.sin_port));

    printf("but now I will sleep 15 second, then exit");
    sleep(15);
}

Start server side, then start client side.

server side may output:

accept a connection from 127.0.0.1:35764
but now I will sleep 15 second, then exit
Process finished with exit code 0

enter image description here

client side may output:

connect to server successsend: 1024000, erron: 0, Success 
send: 1024000, erron: 0, Success 
send: 1024000, erron: 0, Success 
send: 552190, erron: 0, Success 
send: -1, erron: 11, Resource temporarily unavailable 
send: -1, erron: 11, Resource temporarily unavailable 
send: -1, erron: 11, Resource temporarily unavailable 
send: -1, erron: 11, Resource temporarily unavailable 
send: -1, erron: 11, Resource temporarily unavailable 
send: -1, erron: 11, Resource temporarily unavailable 
send: -1, erron: 11, Resource temporarily unavailable 
send: -1, erron: 11, Resource temporarily unavailable 
send: -1, erron: 11, Resource temporarily unavailable 
send: -1, erron: 11, Resource temporarily unavailable 
send: -1, erron: 11, Resource temporarily unavailable 
send: -1, erron: 104, Connection reset by peer 
send: -1, erron: 32, Broken pipe 
send: -1, erron: 32, Broken pipe 
send: -1, erron: 32, Broken pipe 
send: -1, erron: 32, Broken pipe 
send: -1, erron: 32, Broken pipe 

enter image description here

You can see, as the server side doesn't recv the data from client, so when the client side tcp buffer get full, but you still send data, so you may get Resource temporarily unavailable error.

How to deal with the URISyntaxException

I had this exception in the case of a test for checking some actual accessed URLs by users.

And the URLs are sometime contains an illegal-character and hang by this error.

So I make a function to encode only the characters in the URL string like this.

String encodeIllegalChar(String uriStr,String enc)
  throws URISyntaxException,UnsupportedEncodingException {
  String _uriStr = uriStr;
  int retryCount = 17;
  while(true){
     try{
       new URI(_uriStr);
       break;
     }catch(URISyntaxException e){
       String reason = e.getReason();
       if(reason == null ||
         !(
          reason.contains("in path") ||
          reason.contains("in query") ||
          reason.contains("in fragment")
         )
       ){
         throw e;
       }
       if(0 > retryCount--){
         throw e;
       }
       String input = e.getInput();
       int idx = e.getIndex();
       String illChar = String.valueOf(input.charAt(idx));
       _uriStr = input.replace(illChar,URLEncoder.encode(illChar,enc));
     }
  }
  return _uriStr;
}

test:

String q =  "\\'|&`^\"<>)(}{][";
String url = "http://test.com/?q=" + q + "#" + q;
String eic = encodeIllegalChar(url,'UTF-8');
System.out.println(String.format("  original:%s",url));
System.out.println(String.format("   encoded:%s",eic));
System.out.println(String.format("   uri-obj:%s",new URI(eic)));
System.out.println(String.format("re-decoded:%s",URLDecoder.decode(eic)));

C#: HttpClient with POST parameters

As Ben said, you are POSTing your request ( HttpMethod.Post specified in your code )

The querystring (get) parameters included in your url probably will not do anything.

Try this:

string url = "http://myserver/method";    
string content = "param1=1&param2=2";
HttpClientHandler handler = new HttpClientHandler();
HttpClient httpClient = new HttpClient(handler);
HttpRequestMessage request = new HttpRequestMessage(HttpMethod.Post, url);
HttpResponseMessage response = await httpClient.SendAsync(request,content);

HTH,

bovako

Lock down Microsoft Excel macro

Just like you can password protect workbooks and worksheets, you can password protect a macro in Excel from being viewed (and executed).

Place a command button on your worksheet and add the following code lines:

  1. First, create a simple macro that you want to protect.

    Range("A1").Value = "This is secret code"

  2. Next, click Tools, Then VBAProject Properties...

enter image description here

Click Tools, VBAProject Properties...

  1. On the Protection tab, check "Lock project for viewing" and enter a password twice.

enter image description here

Enter a Password Twice

  1. Click OK.

  2. Save, close and reopen the Excel file. Try to view the code.

enter image description here

The following dialog box will appear:

Password Protected from being Viewed

You can still execute the code by clicking on the command button but you cannot view or edit the code anymore (unless you know the password). The password for the downloadable Excel file is "easy".

  1. If you want to password protect the macro from being executed, add the following code lines:
Dim password As Variant
password = Application.InputBox("Enter Password", "Password Protected")

Select Case password
    Case Is = False
        'do nothing
    Case Is = "easy"
        Range("A1").Value = "This is secret code"
    Case Else
        MsgBox "Incorrect Password"
End Select

Result when you click the command button on the sheet:

enter image description here

Password Protected from being Executed

Explanation: The macro uses the InputBox method of the Application object. If the users clicks Cancel, this method returns False and nothing happens (InputBox disappears). Only when the user knows the password ("easy" again), the secret code will be executed. If the entered password is incorrect, a MsgBox is displayed. Note that the user cannot take a look at the password in the Visual Basic Editor because the project is protected from being viewed

Where to place $PATH variable assertions in zsh?

tl;dr version: use ~/.zshrc

And read the man page to understand the differences between:

~/.zshrc, ~/.zshenv and ~/.zprofile.


Regarding my comment

In my comment attached to the answer kev gave, I said:

This seems to be incorrect - /etc/profile isn't listed in any zsh documentation I can find.

This turns out to be partially incorrect: /etc/profile may be sourced by zsh. However, this only occurs if zsh is "invoked as sh or ksh"; in these compatibility modes:

The usual zsh startup/shutdown scripts are not executed. Login shells source /etc/profile followed by $HOME/.profile. If the ENV environment variable is set on invocation, $ENV is sourced after the profile scripts. The value of ENV is subjected to parameter expansion, command substitution, and arithmetic expansion before being interpreted as a pathname. [man zshall, "Compatibility"].

The ArchWiki ZSH link says:

At login, Zsh sources the following files in this order:
/etc/profile
This file is sourced by all Bourne-compatible shells upon login

This implys that /etc/profile is always read by zsh at login - I haven't got any experience with the Arch Linux project; the wiki may be correct for that distribution, but it is not generally correct. The information is incorrect compared to the zsh manual pages, and doesn't seem to apply to zsh on OS X (paths in $PATH set in /etc/profile do not make it to my zsh sessions).



To address the question:

where exactly should I be placing my rvm, python, node etc additions to my $PATH?

Generally, I would export my $PATH from ~/.zshrc, but it's worth having a read of the zshall man page, specifically the "STARTUP/SHUTDOWN FILES" section - ~/.zshrc is read for interactive shells, which may or may not suit your needs - if you want the $PATH for every zsh shell invoked by you (both interactive and not, both login and not, etc), then ~/.zshenv is a better option.

Is there a specific file I should be using (i.e. .zshenv which does not currently exist in my installation), one of the ones I am currently using, or does it even matter?

There's a bunch of files read on startup (check the linked man pages), and there's a reason for that - each file has it's particular place (settings for every user, settings for user-specific, settings for login shells, settings for every shell, etc).
Don't worry about ~/.zshenv not existing - if you need it, make it, and it will be read.

.bashrc and .bash_profile are not read by zsh, unless you explicitly source them from ~/.zshrc or similar; the syntax between bash and zsh is not always compatible. Both .bashrc and .bash_profile are designed for bash settings, not zsh settings.

Html.EditorFor Set Default Value

Shove it in the ViewBag:

Controller:

ViewBag.ProductId = 1;

View:

@Html.TextBoxFor(c => c.Propertyname, new {@Value = ViewBag.ProductId})

Xcode 6.1 - How to uninstall command line tools?

If you installed the command line tools separately, delete them using:

sudo rm -rf /Library/Developer/CommandLineTools

"sed" command in bash

It reads Hello World (cat), replaces all (g) occurrences of % by $ and (over)writes it to /etc/init.d/dropbox as root.

What's the difference between "Write-Host", "Write-Output", or "[console]::WriteLine"?

From my testing Write-Output and [Console]::WriteLine() perform much better than Write-Host.

Depending on how much text you need to write out this may be important.

Below if the result of 5 tests each for Write-Host, Write-Output and [Console]::WriteLine().

In my limited experience, I've found when working with any sort of real world data I need to abandon the cmdlets and go straight for the lower level commands to get any decent performance out of my scripts.

measure-command {$count = 0; while ($count -lt 1000) { Write-Host "hello"; $count++ }}

1312ms
1651ms
1909ms
1685ms
1788ms


measure-command { $count = 0; while ($count -lt 1000) { Write-Output "hello"; $count++ }}

97ms
105ms
94ms
105ms
98ms


measure-command { $count = 0; while ($count -lt 1000) { [console]::WriteLine("hello"); $count++ }}

158ms
105ms
124ms
99ms
95ms

Creating a timer in python

Your code's perfect except that you must do the following replacement:

minutes += 1 #instead of mins = minutes + 1

or

minutes = minutes + 1 #instead of mins = minutes + 1

but here's another solution to this problem:

def wait(time_in_seconds):
    time.sleep(time_in_seconds) #here it would be 1200 seconds (20 mins)

What is the difference between dynamic and static polymorphism in Java?

Polymorphism

1. Static binding/Compile-Time binding/Early binding/Method overloading.(in same class)

2. Dynamic binding/Run-Time binding/Late binding/Method overriding.(in different classes)

overloading example:

class Calculation {  
  void sum(int a,int b){System.out.println(a+b);}  
  void sum(int a,int b,int c){System.out.println(a+b+c);}  

  public static void main(String args[]) {  
    Calculation obj=new Calculation();  
    obj.sum(10,10,10);  // 30
    obj.sum(20,20);     //40 
  }  
}  

overriding example:

class Animal {    
   public void move(){
      System.out.println("Animals can move");
   }
}

class Dog extends Animal {

   public void move() {
      System.out.println("Dogs can walk and run");
   }
}

public class TestDog {

   public static void main(String args[]) {
      Animal a = new Animal(); // Animal reference and object
      Animal b = new Dog(); // Animal reference but Dog object

      a.move();//output: Animals can move

      b.move();//output:Dogs can walk and run
   }
}

Is __init__.py not required for packages in Python 3.3+

I would say that one should omit the __init__.py only if one wants to have the implicit namespace package. If you don't know what it means, you probably don't want it and therefore you should continue to use the __init__.py even in Python 3.

Ordering by the order of values in a SQL IN() clause

For Oracle, John's solution using instr() function works. Here's slightly different solution that worked - SELECT id FROM table1 WHERE id IN (1, 20, 45, 60) ORDER BY instr('1, 20, 45, 60', id)

using jquery $.ajax to call a PHP function

You are going to have to expose and endpoint (URL) in your system which will accept the POST request from the ajax call in jQuery.

Then, when processing that url from PHP, you would call your function and return the result in the appropriate format (JSON most likely, or XML if you prefer).

ReactJS Two components communicating

There are multiple ways to make components communicate. Some can be suited to your usecase. Here is a list of some I've found useful to know.

React

Parent / Child direct communication

const Child = ({fromChildToParentCallback}) => (
  <div onClick={() => fromChildToParentCallback(42)}>
    Click me
  </div>
);

class Parent extends React.Component {
  receiveChildValue = (value) => {
    console.log("Parent received value from child: " + value); // value is 42
  };
  render() {
    return (
      <Child fromChildToParentCallback={this.receiveChildValue}/>
    )
  }
}

Here the child component will call a callback provided by the parent with a value, and the parent will be able to get the value provided by the children in the parent.

If you build a feature/page of your app, it's better to have a single parent managing the callbacks/state (also called container or smart component), and all childs to be stateless, only reporting things to the parent. This way you can easily "share" the state of the parent to any child that need it.


Context

React Context permits to hold state at the root of your component hierarchy, and be able to inject this state easily into very deeply nested components, without the hassle to have to pass down props to every intermediate components.

Until now, context was an experimental feature, but a new API is available in React 16.3.

const AppContext = React.createContext(null)

class App extends React.Component {
  render() {
    return (
      <AppContext.Provider value={{language: "en",userId: 42}}>
        <div>
          ...
          <SomeDeeplyNestedComponent/>
          ...
        </div>
      </AppContext.Provider>
    )
  }
};

const SomeDeeplyNestedComponent = () => (
  <AppContext.Consumer>
    {({language}) => <div>App language is currently {language}</div>}
  </AppContext.Consumer>
);

The consumer is using the render prop / children function pattern

Check this blog post for more details.

Before React 16.3, I'd recommend using react-broadcast which offer quite similar API, and use former context API.


Portals

Use a portal when you'd like to keep 2 components close together to make them communicate with simple functions, like in normal parent / child, but you don't want these 2 components to have a parent/child relationship in the DOM, because of visual / CSS constraints it implies (like z-index, opacity...).

In this case you can use a "portal". There are different react libraries using portals, usually used for modals, popups, tooltips...

Consider the following:

<div className="a">
    a content
    <Portal target="body">
        <div className="b">
            b content
        </div>
    </Portal>
</div>

Could produce the following DOM when rendered inside reactAppContainer:

<body>
    <div id="reactAppContainer">
        <div className="a">
             a content
        </div>
    </div>
    <div className="b">
         b content
    </div>
</body>

More details here


Slots

You define a slot somewhere, and then you fill the slot from another place of your render tree.

import { Slot, Fill } from 'react-slot-fill';

const Toolbar = (props) =>
  <div>
    <Slot name="ToolbarContent" />
  </div>

export default Toolbar;

export const FillToolbar = ({children}) =>
  <Fill name="ToolbarContent">
    {children}
  </Fill>

This is a bit similar to portals except the filled content will be rendered in a slot you define, while portals generally render a new dom node (often a children of document.body)

Check react-slot-fill library


Event bus

As stated in the React documentation:

For communication between two components that don't have a parent-child relationship, you can set up your own global event system. Subscribe to events in componentDidMount(), unsubscribe in componentWillUnmount(), and call setState() when you receive an event.

There are many things you can use to setup an event bus. You can just create an array of listeners, and on event publish, all listeners would receive the event. Or you can use something like EventEmitter or PostalJs


Flux

Flux is basically an event bus, except the event receivers are stores. This is similar to the basic event bus system except the state is managed outside of React

Original Flux implementation looks like an attempt to do Event-sourcing in a hacky way.

Redux is for me the Flux implementation that is the closest from event-sourcing, an benefits many of event-sourcing advantages like the ability to time-travel. It is not strictly linked to React and can also be used with other functional view libraries.

Egghead's Redux video tutorial is really nice and explains how it works internally (it really is simple).


Cursors

Cursors are coming from ClojureScript/Om and widely used in React projects. They permit to manage the state outside of React, and let multiple components have read/write access to the same part of the state, without needing to know anything about the component tree.

Many implementations exists, including ImmutableJS, React-cursors and Omniscient

Edit 2016: it seems that people agree cursors work fine for smaller apps but it does not scale well on complex apps. Om Next does not have cursors anymore (while it's Om that introduced the concept initially)


Elm architecture

The Elm architecture is an architecture proposed to be used by the Elm language. Even if Elm is not ReactJS, the Elm architecture can be done in React as well.

Dan Abramov, the author of Redux, did an implementation of the Elm architecture using React.

Both Redux and Elm are really great and tend to empower event-sourcing concepts on the frontend, both allowing time-travel debugging, undo/redo, replay...

The main difference between Redux and Elm is that Elm tend to be a lot more strict about state management. In Elm you can't have local component state or mount/unmount hooks and all DOM changes must be triggered by global state changes. Elm architecture propose a scalable approach that permits to handle ALL the state inside a single immutable object, while Redux propose an approach that invites you to handle MOST of the state in a single immutable object.

While the conceptual model of Elm is very elegant and the architecture permits to scale well on large apps, it can in practice be difficult or involve more boilerplate to achieve simple tasks like giving focus to an input after mounting it, or integrating with an existing library with an imperative interface (ie JQuery plugin). Related issue.

Also, Elm architecture involves more code boilerplate. It's not that verbose or complicated to write but I think the Elm architecture is more suited to statically typed languages.


FRP

Libraries like RxJS, BaconJS or Kefir can be used to produce FRP streams to handle communication between components.

You can try for example Rx-React

I think using these libs is quite similar to using what the ELM language offers with signals.

CycleJS framework does not use ReactJS but uses vdom. It share a lot of similarities with the Elm architecture (but is more easy to use in real life because it allows vdom hooks) and it uses RxJs extensively instead of functions, and can be a good source of inspiration if you want to use FRP with React. CycleJs Egghead videos are nice to understand how it works.


CSP

CSP (Communicating Sequential Processes) are currently popular (mostly because of Go/goroutines and core.async/ClojureScript) but you can use them also in javascript with JS-CSP.

James Long has done a video explaining how it can be used with React.

Sagas

A saga is a backend concept that comes from the DDD / EventSourcing / CQRS world, also called "process manager". It is being popularized by the redux-saga project, mostly as a replacement to redux-thunk for handling side-effects (ie API calls etc). Most people currently think it only services for side-effects but it is actually more about decoupling components.

It is more of a compliment to a Flux architecture (or Redux) than a totally new communication system, because the saga emit Flux actions at the end. The idea is that if you have widget1 and widget2, and you want them to be decoupled, you can't fire action targeting widget2 from widget1. So you make widget1 only fire actions that target itself, and the saga is a "background process" that listens for widget1 actions, and may dispatch actions that target widget2. The saga is the coupling point between the 2 widgets but the widgets remain decoupled.

If you are interested take a look at my answer here


Conclusion

If you want to see an example of the same little app using these different styles, check the branches of this repository.

I don't know what is the best option in the long term but I really like how Flux looks like event-sourcing.

If you don't know event-sourcing concepts, take a look at this very pedagogic blog: Turning the database inside out with apache Samza, it is a must-read to understand why Flux is nice (but this could apply to FRP as well)

I think the community agrees that the most promising Flux implementation is Redux, which will progressively allow very productive developer experience thanks to hot reloading. Impressive livecoding ala Bret Victor's Inventing on Principle video is possible!

html5 localStorage error with Safari: "QUOTA_EXCEEDED_ERR: DOM Exception 22: An attempt was made to add something to storage that exceeded the quota."

In my context, just developed a class abstraction. When my application is launched, i check if localStorage is working by calling getStorage(). This function also return :

  • either localStorage if localStorage is working
  • or an implementation of a custom class LocalStorageAlternative

In my code i never call localStorage directly. I call cusStoglobal var, i had initialised by calling getStorage().

This way, it works with private browsing or specific Safari versions

function getStorage() {

    var storageImpl;

     try { 
        localStorage.setItem("storage", ""); 
        localStorage.removeItem("storage");
        storageImpl = localStorage;
     }
     catch (err) { 
         storageImpl = new LocalStorageAlternative();
     }

    return storageImpl;

}

function LocalStorageAlternative() {

    var structureLocalStorage = {};

    this.setItem = function (key, value) {
        structureLocalStorage[key] = value;
    }

    this.getItem = function (key) {
        if(typeof structureLocalStorage[key] != 'undefined' ) {
            return structureLocalStorage[key];
        }
        else {
            return null;
        }
    }

    this.removeItem = function (key) {
        structureLocalStorage[key] = undefined;
    }
}

cusSto = getStorage();

How does "304 Not Modified" work exactly?

When the browser puts something in its cache, it also stores the Last-Modified or ETag header from the server.

The browser then sends a request with the If-Modified-Since or If-None-Match header, telling the server to send a 304 if the content still has that date or ETag.

The server needs some way of calculating a date-modified or ETag for each version of each resource; this typically comes from the filesystem or a separate database column.

How to do a newline in output

I would like to share my experience with \n
I came to notice that "\n" works as-

puts "\n\n" // to provide 2 new lines

but not

p "\n\n"

also puts '\n\n'
Doesn't works.

Hope will work for you!!

How to get row count in an Excel file using POI library?

Since Sheet.getPhysicalNumberOfRows() does not count empty rows and Sheet.getLastRowNum() returns 0 both if there is one row or no rows, I use a combination of the two methods to accurately calculate the total number of rows.

int rowTotal = sheet.getLastRowNum();

if ((rowTotal > 0) || (sheet.getPhysicalNumberOfRows() > 0)) {
    rowTotal++;
}

Note: This will treat a spreadsheet with one empty row as having none but for most purposes this is probably okay.

Can I remove the URL from my print css, so the web address doesn't print?

Remove the url from header and footer using below method

 @page { size: letter;  margin-top: 4mm;margin-bottom: 4mm }

Can't get private key with openssl (no start line:pem_lib.c:703:Expecting: ANY PRIVATE KEY)

My two cents: came across the same error message in RHEL7.3 while running the openssl command with root CA certificate. The reason being, while downloading the certificate from AD server, Encoding was selected as DER instead of Base64. Once the proper version of encoding was selected for the new certificate download, error was resolved

Hope this helps for new users :-)

How do I lowercase a string in Python?

Also, you can overwrite some variables:

s = input('UPPER CASE')
lower = s.lower()

If you use like this:

s = "Kilometer"
print(s.lower())     - kilometer
print(s)             - Kilometer

It will work just when called.

How to get the primary IP address of the local machine on Linux and OS X?

On a Mac, consider the following:

scutil --nwi | grep -Eo '[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}'

How to trigger click event on href element

In addition to romkyns's great answer.. here is some relevant documentation/examples.


DOM Elements have a native .click() method.

The HTMLElement.click() method simulates a mouse click on an element.

When click is used, it also fires the element's click event which will bubble up to elements higher up the document tree (or event chain) and fire their click events too. However, bubbling of a click event will not cause an <a> element to initiate navigation as if a real mouse-click had been received. (mdn reference)

Relevant W3 documentation.


A few examples..

  • You can access a specific DOM element from a jQuery object: (example)

      $('a')[0].click();
    
  • You can use the .get() method to retrieve a DOM element from a jQuery object: (example)

      $('a').get(0).click();
    
  • As expected, you can select the DOM element and call the .click() method. (example)

      document.querySelector('a').click();
    

It's worth pointing out that jQuery is not required to trigger a native .click() event.

Contain form within a bootstrap popover?

I work in WordPress a lot so use PHP.

My method is to contain my HTML in a PHP Variable, and then echo the variable in data-content.

$my-data-content = '<form><input type="text"/></form>';

along with

data-content='<?php echo $my-data-content; ?>' 

How can I pass request headers with jQuery's getJSON() method?

I think you could set the headers and still use getJSON() like this:

$.ajaxSetup({
  headers : {
    'Authorization' : 'Basic faskd52352rwfsdfs',
    'X-PartnerKey' : '3252352-sdgds-sdgd-dsgs-sgs332fs3f'
  }
});
$.getJSON('http://localhost:437/service.svc/logins/jeffrey/house/fas6347/devices?format=json', function(json) { alert("Success"); }); 

How to pass arguments within docker-compose?

This can now be done as of docker-compose v2+ as part of the build object;

docker-compose.yml

version: '2'
services:
    my_image_name:
        build:
            context: . #current dir as build context
            args:
                var1: 1
                var2: c

See the docker compose docs.

In the above example "var1" and "var2" will be sent to the build environment.

Note: any env variables (specified by using the environment block) which have the same name as args variable(s) will override that variable.

Understanding ibeacon distancing

The iBeacon output power is measured (calibrated) at a distance of 1 meter. Let's suppose that this is -59 dBm (just an example). The iBeacon will include this number as part of its LE advertisment.

The listening device (iPhone, etc), will measure the RSSI of the device. Let's suppose, for example, that this is, say, -72 dBm.

Since these numbers are in dBm, the ratio of the power is actually the difference in dB. So:

ratio_dB = txCalibratedPower - RSSI

To convert that into a linear ratio, we use the standard formula for dB:

ratio_linear = 10 ^ (ratio_dB / 10)

If we assume conservation of energy, then the signal strength must fall off as 1/r^2. So:

power = power_at_1_meter / r^2. Solving for r, we get:

r = sqrt(ratio_linear)

In Javascript, the code would look like this:

function getRange(txCalibratedPower, rssi) {
    var ratio_db = txCalibratedPower - rssi;
    var ratio_linear = Math.pow(10, ratio_db / 10);

    var r = Math.sqrt(ratio_linear);
    return r;
}

Note, that, if you're inside a steel building, then perhaps there will be internal reflections that make the signal decay slower than 1/r^2. If the signal passes through a human body (water) then the signal will be attenuated. It's very likely that the antenna doesn't have equal gain in all directions. Metal objects in the room may create strange interference patterns. Etc, etc... YMMV.

How to pass parameters to the DbContext.Database.ExecuteSqlCommand method?

If your underlying database data types are varchar then you should stick with the approach below. Otherwise the query would have a huge performance impact.

var firstName = new SqlParameter("@firstName", System.Data.SqlDbType.VarChar, 20)
                            {
                                Value = "whatever"
                            };

var id = new SqlParameter("@id", System.Data.SqlDbType.Int)
                            {
                                Value = 1
                            };
ctx.Database.ExecuteSqlCommand(@"Update [User] SET FirstName = @firstName WHERE Id = @id"
                               , firstName, id);

You can check Sql profiler to see the difference.

Open links in new window using AngularJS

@m59 Directives will work for ng-bind-html you just need to wait for $viewContentLoaded to finish

app.directive('targetBlank', function($timeout) {
  return function($scope, element) {
    $scope.initializeTarget = function() {
      return $scope.$on('$viewContentLoaded', $timeout(function() {
        var elems;
        elems = element.prop('tagName') === 'A' ? element : element.find('a');
        elems.attr('target', '_blank');
      }));
    };
    return $scope.initializeTarget();

  };
});

RecyclerView onClick

You can pass a clickListener to Adapter.

In your Activity:

private View.OnClickListener mItemClick = new View.OnClickListener() {

    @Override
    public void onClick(View v) {
        Intent intent = null;
        int position = list.getChildPosition(v);
        switch (position) {
            case 0:
                intent = new Intent(MainActivity.this, LeakCanaryActivity.class);
                break;
            case 1:
                intent = new Intent(MainActivity.this, ButterKnifeFragmentActivity.class);
                break;
        }
        if (intent != null) {
            MainActivity.this.startActivity(intent);
        }
    }
};

then pass it to Adapter:

MainAdapter mainAdapter = new MainAdapter(this, mItemClick);

In Adapter's onCreateViewHolder:

 @Override
public MainAdapter.ViewHolder onCreateViewHolder(ViewGroup viewGroup, int position) {
    View itemView = activity.getLayoutInflater().inflate(R.layout.main_adapter_item, viewGroup, false);
    ViewHolder holder = new ViewHolder(itemView);
    itemView.setOnClickListener(mItemClick);
    return holder;
}

What is a 'Closure'?

Closure is very easy. We can consider it as follows : Closure = function + its lexical environment

Consider the following function:

function init() {
    var name = “Mozilla”;
}

What will be the closure in the above case ? Function init() and variables in its lexical environment ie name. Closure = init() + name

Consider another function :

function init() {
    var name = “Mozilla”;
    function displayName(){
        alert(name);
}
displayName();
}

What will be the closures here ? Inner function can access variables of outer function. displayName() can access the variable name declared in the parent function, init(). However, the same local variables in displayName() will be used if they exists.

Closure 1 : init function + ( name variable + displayName() function) --> lexical scope

Closure 2 : displayName function + ( name variable ) --> lexical scope

DateTime.TryParse issue with dates of yyyy-dd-MM format

DateTime dt = DateTime.ParseExact("11-22-2012 12:00 am", "MM-dd-yyyy hh:mm tt", System.Globalization.CultureInfo.InvariantCulture);

Chrome extension: accessing localStorage in content script

Update 2016:

Google Chrome released the storage API: http://developer.chrome.com/extensions/storage.html

It is pretty easy to use like the other Chrome APIs and you can use it from any page context within Chrome.

    // Save it using the Chrome extension storage API.
    chrome.storage.sync.set({'foo': 'hello', 'bar': 'hi'}, function() {
      console.log('Settings saved');
    });

    // Read it using the storage API
    chrome.storage.sync.get(['foo', 'bar'], function(items) {
      message('Settings retrieved', items);
    });

To use it, make sure you define it in the manifest:

    "permissions": [
      "storage"
    ],

There are methods to "remove", "clear", "getBytesInUse", and an event listener to listen for changed storage "onChanged"

Using native localStorage (old reply from 2011)

Content scripts run in the context of webpages, not extension pages. Therefore, if you're accessing localStorage from your contentscript, it will be the storage from that webpage, not the extension page storage.

Now, to let your content script to read your extension storage (where you set them from your options page), you need to use extension message passing.

The first thing you do is tell your content script to send a request to your extension to fetch some data, and that data can be your extension localStorage:

contentscript.js

chrome.runtime.sendMessage({method: "getStatus"}, function(response) {
  console.log(response.status);
});

background.js

chrome.runtime.onMessage.addListener(function(request, sender, sendResponse) {
    if (request.method == "getStatus")
      sendResponse({status: localStorage['status']});
    else
      sendResponse({}); // snub them.
});

You can do an API around that to get generic localStorage data to your content script, or perhaps, get the whole localStorage array.

I hope that helped solve your problem.

To be fancy and generic ...

contentscript.js

chrome.runtime.sendMessage({method: "getLocalStorage", key: "status"}, function(response) {
  console.log(response.data);
});

background.js

chrome.runtime.onMessage.addListener(function(request, sender, sendResponse) {
    if (request.method == "getLocalStorage")
      sendResponse({data: localStorage[request.key]});
    else
      sendResponse({}); // snub them.
});

Removing NA in dplyr pipe

I don't think desc takes an na.rm argument... I'm actually surprised it doesn't throw an error when you give it one. If you just want to remove NAs, use na.omit (base) or tidyr::drop_na:

outcome.df %>%
  na.omit() %>%
  group_by(Hospital, State) %>%
  arrange(desc(HeartAttackDeath)) %>%
  head()

library(tidyr)
outcome.df %>%
  drop_na() %>%
  group_by(Hospital, State) %>%
  arrange(desc(HeartAttackDeath)) %>%
  head()

If you only want to remove NAs from the HeartAttackDeath column, filter with is.na, or use tidyr::drop_na:

outcome.df %>%
  filter(!is.na(HeartAttackDeath)) %>%
  group_by(Hospital, State) %>%
  arrange(desc(HeartAttackDeath)) %>%
  head()

outcome.df %>%
  drop_na(HeartAttackDeath) %>%
  group_by(Hospital, State) %>%
  arrange(desc(HeartAttackDeath)) %>%
  head()

As pointed out at the dupe, complete.cases can also be used, but it's a bit trickier to put in a chain because it takes a data frame as an argument but returns an index vector. So you could use it like this:

outcome.df %>%
  filter(complete.cases(.)) %>%
  group_by(Hospital, State) %>%
  arrange(desc(HeartAttackDeath)) %>%
  head()

R Markdown - changing font size and font type in html output

I would definitely use html markers to achieve this. Just surround your text with <p></p> or <font></font> and add the desired attributes. See the following example:

<p style="font-family: times, serif; font-size:11pt; font-style:italic">
    Why did we use these specific parameters during the calculation of the fingerprints?
</p>

This will produce the following output

Font Output

compared to

Default Output

This would work with Jupyter Notebook as well as Typora, but I'm not sure if it is universal.

Lastly, be aware that the html marker overrides the font styling used by Markdown.

How to split a file into equal parts, without breaking individual lines?

If you mean an equal number of lines, split has an option for this:

split --lines=75

If you need to know what that 75 should really be for N equal parts, its:

lines_per_part = int(total_lines + N - 1) / N

where total lines can be obtained with wc -l.

See the following script for an example:

#!/usr/bin/bash

# Configuration stuff

fspec=qq.c
num_files=6

# Work out lines per file.

total_lines=$(wc -l <${fspec})
((lines_per_file = (total_lines + num_files - 1) / num_files))

# Split the actual file, maintaining lines.

split --lines=${lines_per_file} ${fspec} xyzzy.

# Debug information

echo "Total lines     = ${total_lines}"
echo "Lines  per file = ${lines_per_file}"    
wc -l xyzzy.*

This outputs:

Total lines     = 70
Lines  per file = 12
  12 xyzzy.aa
  12 xyzzy.ab
  12 xyzzy.ac
  12 xyzzy.ad
  12 xyzzy.ae
  10 xyzzy.af
  70 total

More recent versions of split allow you to specify a number of CHUNKS with the -n/--number option. You can therefore use something like:

split --number=l/6 ${fspec} xyzzy.

(that's ell-slash-six, meaning lines, not one-slash-six).

That will give you roughly equal files in terms of size, with no mid-line splits.

I mention that last point because it doesn't give you roughly the same number of lines in each file, more the same number of characters.

So, if you have one 20-character line and 19 1-character lines (twenty lines in total) and split to five files, you most likely won't get four lines in every file.

How can I convert a string with dot and comma into a float in Python

Just replace, with replace().

f = float("123,456.908".replace(',','')) print(type(f)

type() will show you that it has converted into a float

Do you recommend using semicolons after every statement in JavaScript?

I'd say consistency is more important than saving a few bytes. I always include semicolons.

On the other hand, I'd like to point out there are many places where the semicolon is not syntactically required, even if a compressor is nuking all available whitespace. e.g. at then end of a block.

if (a) { b() }

Multi value Dictionary

If you are trying to group values together this may be a great opportunity to create a simple struct or class and use that as the value in a dictionary.

public struct MyValue
{
    public object Value1;
    public double Value2;
}

then you could have your dictionary

var dict = new Dictionary<int, MyValue>();

you could even go a step further and implement your own dictionary class that will handle any special operations that you would need. for example if you wanted to have an Add method that accepted an int, object, and double

public class MyDictionary : Dictionary<int, MyValue>
{
    public void Add(int key, object value1, double value2)
    {
        MyValue val;
        val.Value1 = value1;
        val.Value2 = value2;
        this.Add(key, val);
    }
}

then you could simply instantiate and add to the dictionary like so and you wouldn't have to worry about creating 'MyValue' structs:

var dict = new MyDictionary();
dict.Add(1, new Object(), 2.22);

Finding all possible permutations of a given string in python

Here's a simple function to return unique permutations:

def permutations(string):
    if len(string) == 1:
        return string

    recursive_perms = []
    for c in string:
        for perm in permutations(string.replace(c,'',1)):
            revursive_perms.append(c+perm)

    return set(revursive_perms)

Download file from web in Python 3

If you are using Linux you can use the wget module of Linux through the python shell. Here is a sample code snippet

import os
url = 'http://www.example.com/foo.zip'
os.system('wget %s'%url)

How do I replace part of a string in PHP?

Just do:

$text = str_replace(' ', '_', $text)

Draw horizontal rule in React Native

You could simply use an empty View with a bottom border.

<View
  style={{
    borderBottomColor: 'black',
    borderBottomWidth: 1,
  }}
/>

MySQL Insert into multiple tables? (Database normalization?)

No, you can't insert into multiple tables in one MySQL command. You can however use transactions.

BEGIN;
INSERT INTO users (username, password)
  VALUES('test', 'test');
INSERT INTO profiles (userid, bio, homepage) 
  VALUES(LAST_INSERT_ID(),'Hello world!', 'http://www.stackoverflow.com');
COMMIT;

Have a look at LAST_INSERT_ID() to reuse autoincrement values.

Edit: you said "After all this time trying to figure it out, it still doesn't work. Can't I simply put the just generated ID in a $var and put that $var in all the MySQL commands?"

Let me elaborate: there are 3 possible ways here:

  1. In the code you see above. This does it all in MySQL, and the LAST_INSERT_ID() in the second statement will automatically be the value of the autoincrement-column that was inserted in the first statement.

    Unfortunately, when the second statement itself inserts rows in a table with an auto-increment column, the LAST_INSERT_ID() will be updated to that of table 2, and not table 1. If you still need that of table 1 afterwards, we will have to store it in a variable. This leads us to ways 2 and 3:

  2. Will stock the LAST_INSERT_ID() in a MySQL variable:

    INSERT ...
    SELECT LAST_INSERT_ID() INTO @mysql_variable_here;
    INSERT INTO table2 (@mysql_variable_here, ...);
    INSERT INTO table3 (@mysql_variable_here, ...);
    
  3. Will stock the LAST_INSERT_ID() in a php variable (or any language that can connect to a database, of your choice):

    • INSERT ...
    • Use your language to retrieve the LAST_INSERT_ID(), either by executing that literal statement in MySQL, or using for example php's mysql_insert_id() which does that for you
    • INSERT [use your php variable here]

WARNING

Whatever way of solving this you choose, you must decide what should happen should the execution be interrupted between queries (for example, your database-server crashes). If you can live with "some have finished, others not", don't read on.

If however you decide "either all queries finish, or none finish - I do not want rows in some tables but no matching rows in others, I always want my database tables to be consistent", you need to wrap all statements in a transaction. That's why I used the BEGIN and COMMIT here.

Comment again if you need more info :)

Writing List of Strings to Excel CSV File in Python

Very simple to fix, you just need to turn the parameter to writerow into a list.

for item in RESULTS:
     wr.writerow([item,])

"detached entity passed to persist error" with JPA/EJB code

if you use to generate the id = GenerationType.AUTO strategy in your entity.

Replaces user.setId (1) by user.setId (null), and the problem is solved.

Changing column names of a data frame

Use this to change column name by colname function.

colnames(newprice)[1] = "premium"
colnames(newprice)[2] = "change"
colnames(newprice)[3] = "newprice"

CSS: 100% font size - 100% of what?

Relative to the default size defined to that font.

If someone opens your page on a web browser, there's a default font and font size it uses.

Split string into strings by length?

Here is a one-liner that doesn't need to know the length of the string beforehand:

from functools import partial
from StringIO import StringIO

[l for l in iter(partial(StringIO(data).read, 4), '')]

If you have a file or socket, then you don't need the StringIO wrapper:

[l for l in iter(partial(file_like_object.read, 4), '')]

sorting integers in order lowest to highest java

There are two options, really:

  1. Use standard collections, as explained by Shakedown
  2. Use Arrays.sort

E.g.,

int[] ints = {11367, 11358, 11421, 11530, 11491, 11218, 11789};
Arrays.sort(ints);
System.out.println(Arrays.asList(ints));

That of course assumes that you already have your integers as an array. If you need to parse those first, look for String.split and Integer.parseInt.

MySQL: Error Code: 1118 Row size too large (> 8126). Changing some columns to TEXT or BLOB

If you're getting this error on Google Cloud SQL (mysql 5.7 for example) then it's probably not at this time going to be a simple fix as not all InnoDB flags are supported. If you're coming across from Mysql 5.5 as I was (for an old Wordpress setup) this could mean you need to wrangle some column types in the source database before you export.

Some more information can be found here.

Find the most common element in a list

A one-liner:

def most_common (lst):
    return max(((item, lst.count(item)) for item in set(lst)), key=lambda a: a[1])[0]

How to find pg_config path

I recommend that you try to use Postgres.app. (http://postgresapp.com) This way you can easily turn Postgres on and off on your Mac. Once you do, add the path to Postgres to your .profile file by appending the following:

PATH="/Applications/Postgres.app/Contents/Versions/latest/bin:$PATH"

Only after you added Postgres to your path you can try to install psycopg2 either within a virtual environment (using pip) or into your global site packages.

Why does Java's hashCode() in String use 31 as a multiplier?

I'm not sure, but I would guess they tested some sample of prime numbers and found that 31 gave the best distribution over some sample of possible Strings.

How do I line up 3 divs on the same row?

2019 answer:

Using CSS grid:

.parent {
  display: grid;
  grid-template-columns: 1fr 1fr 1fr;
  grid-template-rows: 1fr;
}

Difference between Visual Basic 6.0 and VBA

VBA stands for Visual Basic for Applications and so is the small "for applications" scripting brother of VB. VBA is indeed available in Excel, but also in the other office applications.

With VB, one can create a stand-alone windows application, which is not possible with VBA.

It is possible for developers however to "embed" VBA in their own applications, as a scripting language to automate those applications.

Edit: From the VBA FAQ:

Q. What is Visual Basic for Applications?

A. Microsoft Visual Basic for Applications (VBA) is an embeddable programming environment designed to enable developers to build custom solutions using the full power of Microsoft Visual Basic. Developers using applications that host VBA can automate and extend the application functionality, shortening the development cycle of custom business solutions.

Note that VB.NET is even another language, which only shares syntax with VB.

Create Word Document using PHP in Linux

OpenOffice templates + OOo command line interface.

  1. Create manually an ODT template with placeholders, like [%value-to-replace%]
  2. When instantiating the template with real data in PHP, unzip the template ODT (it's a zipped XML), and run against the XML the textual replace of the placeholders with the actual values.
  3. Zip the ODT back
  4. Run the conversion ODT -> DOC via OpenOffice command line interface.

There are tools and libraries available to ease each of those steps.

May be that helps.

How to render an array of objects in React?

Shubham's answer explains very well. This answer is addition to it as per to avoid some pitfalls and refactoring to a more readable syntax

Pitfall : There is common misconception in rendering array of objects especially if there is an update or delete action performed on data. Use case would be like deleting an item from table row. Sometimes when row which is expected to be deleted, does not get deleted and instead other row gets deleted.

To avoid this, use key prop in root element which is looped over in JSX tree of .map(). Also adding React's Fragment will avoid adding another element in between of ul and li when rendered via calling method.

state = {
    userData: [
        { id: '1', name: 'Joe', user_type: 'Developer' },
        { id: '2', name: 'Hill', user_type: 'Designer' }
    ]
};

deleteUser = id => {
    // delete operation to remove item
};

renderItems = () => {
    const data = this.state.userData;

    const mapRows = data.map((item, index) => (
        <Fragment key={item.id}>
            <li>
                {/* Passing unique value to 'key' prop, eases process for virtual DOM to remove specific element and update HTML tree  */}
                <span>Name : {item.name}</span>
                <span>User Type: {item.user_type}</span>
                <button onClick={() => this.deleteUser(item.id)}>
                    Delete User
                </button>
            </li>
        </Fragment>
    ));
    return mapRows;
};

render() {
    return <ul>{this.renderItems()}</ul>;
}

Important : Decision to use which value should we pass to key prop also matters as common way is to use index parameter provided by .map().

TLDR; But there's a drawback to it and avoid it as much as possible and use any unique id from data which is being iterated such as item.id. There's a good article on this - https://medium.com/@robinpokorny/index-as-a-key-is-an-anti-pattern-e0349aece318

Batch Extract path and filename from a variable

Late answer, I know, but for me the following script is quite useful - and it answers the question too, hitting two flys with one flag ;-)

The following script expands SendTo in the file explorer's context menu:

@echo off
cls
if "%~dp1"=="" goto Install

REM change drive, then cd to path given and run shell there
%~d1
cd "%~dp1"
cmd /k
goto End

:Install
rem No arguments: Copies itself into SendTo folder
copy "%0" "%appdata%\Microsoft\Windows\SendTo\A - Open in CMD shell.cmd"

:End

If you run this script without any parameters by double-clicking on it, it will copy itself to the SendTo folder and renaming it to "A - Open in CMD shell.cmd". Afterwards it is available in the "SentTo" context menu.

Then, right-click on any file or folder in Windows explorer and select "SendTo > A - Open in CMD shell.cmd"

The script will change drive and path to the path containing the file or folder you have selected and open a command shell with that path - useful for Visual Studio Code, because then you can just type "code ." to run it in the context of your project.

How does it work?

%0 - full path of the batch script
%~d1 - the drive contained in the first argument (e.g. "C:")
%~dp1 - the path contained in the first argument
cmd /k - opens a command shell which stays open

Not used here, but %~n1 is the file name of the first argument.

I hope this is helpful for someone.

Load CSV data into MySQL in Python

using pymsql if it helps

import pymysql
import csv
db = pymysql.connect("localhost","root","12345678","data" )

cursor = db.cursor()
csv_data = csv.reader(open('test.csv'))
next(csv_data)
for row in csv_data:
    cursor.execute('INSERT INTO PM(col1,col2) VALUES(%s, %s)',row)

db.commit()
cursor.close()

Replace all particular values in a data frame

Here are a couple dplyr options:

library(dplyr)

# all columns:
df %>% 
  mutate_all(~na_if(., ''))

# specific column types:
df %>% 
  mutate_if(is.factor, ~na_if(., ''))

# specific columns:  
df %>% 
  mutate_at(vars(A, B), ~na_if(., ''))

# or:
df %>% 
  mutate(A = replace(A, A == '', NA))

# replace can be used if you want something other than NA:
df %>% 
  mutate(A = as.character(A)) %>% 
  mutate(A = replace(A, A == '', 'used to be empty'))

What is the relative performance difference of if/else versus switch statement in Java?

It's extremely unlikely that an if/else or a switch is going to be the source of your performance woes. If you're having performance problems, you should do a performance profiling analysis first to determine where the slow spots are. Premature optimization is the root of all evil!

Nevertheless, it's possible to talk about the relative performance of switch vs. if/else with the Java compiler optimizations. First note that in Java, switch statements operate on a very limited domain -- integers. In general, you can view a switch statement as follows:

switch (<condition>) {
   case c_0: ...
   case c_1: ...
   ...
   case c_n: ...
   default: ...
}

where c_0, c_1, ..., and c_N are integral numbers that are targets of the switch statement, and <condition> must resolve to an integer expression.

  • If this set is "dense" -- that is, (max(ci) + 1 - min(ci)) / n > α, where 0 < k < α < 1, where k is larger than some empirical value, a jump table can be generated, which is highly efficient.

  • If this set is not very dense, but n >= β, a binary search tree can find the target in O(2 * log(n)) which is still efficient too.

For all other cases, a switch statement is exactly as efficient as the equivalent series of if/else statements. The precise values of α and β depend on a number of factors and are determined by the compiler's code-optimization module.

Finally, of course, if the domain of <condition> is not the integers, a switch statement is completely useless.

changing color of h2

If you absolutely must use HTML to give your text color, you have to use the (deprecated) <font>-tag:

<h2><font color="#006699">Process Report</font></h2>

But otherwise, I strongly recommend you to do as rekire said: use CSS.

Error "The goal you specified requires a project to execute but there is no POM in this directory" after executing maven command

Just watch out for any spaces or errors in your arguments/command. The mvn error message may not be so descriptive but I have realised, usually spaces/omissions can also cause that error.

IndentationError: unexpected unindent WHY?

It's because you have:

def readTTable(fname):
    try:

without a matching except block after the try: block. Every try must have at least one matching except.

See the Errors and Exceptions section of the Python tutorial.

Where can I find a list of Mac virtual key codes?

In addition to the keycodes supplied in other answers, there are also "usage IDs" used for key remapping in the newer APIs introduced in macOS Sierra:

Technical Note TN2450

Remapping Keys in macOS 10.12 Sierra

Under macOS Sierra 10.12, the mechanism for key remapping was changed. This Technical Note is for developers of key remapping software so that they can update their software to support macOS Sierra 10.12. We present 2 solutions for implementing key remapping functionality for macOS 10.12 in this Technical Note.

https://developer.apple.com/library/archive/technotes/tn2450/_index.html

Keyboard a and A - 0x04
Keyboard b and B - 0x05
Keyboard c and C - 0x06
Keyboard d and D - 0x07
Keyboard e and E - 0x08
...

Error: 0xC0202009 at Data Flow Task, OLE DB Destination [43]: SSIS Error Code DTS_E_OLEDBERROR. An OLE DB error has occurred. Error code: 0x80040E21

In my case the underlying system account through which the package was running was locked out. Once we got the system account unlocked and reran the package, it executed successfully. The developer said that he got to know of this while debugging wherein he directly tried to connect to the server and check the status of the connection.

Read binary file as string in Ruby

If you need binary mode, you'll need to do it the hard way:

s = File.open(filename, 'rb') { |f| f.read }

If not, shorter and sweeter is:

s = IO.read(filename)

Object reference not set to an instance of an object.

I want to extend MattMitchell's answer by saying you can create an extension method for this functionality:

public static IsEmptyOrWhitespace(this string value) {
    return String.IsEmptyOrWhitespace(value);
}

This makes it possible to call:

string strValue;
if (strValue.IsEmptyOrWhitespace())
     // do stuff

To me this is a lot cleaner than calling the static String function, while still being NullReference safe!

Make an image follow mouse pointer

by using jquery to register .mousemove to document to change the image .css left and top to event.pageX and event.pageY.

example as below http://jsfiddle.net/BfLAh/1/

_x000D_
_x000D_
$(document).mousemove(function(e) {
  $("#follow").css({
    left: e.pageX,
    top: e.pageY
  });
});
_x000D_
#follow {
  position: absolute;
  text-align: center;
}
_x000D_
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<div id="follow"><img src="https://placekitten.com/96/140" /><br>Kitteh</br>
</div>
_x000D_
_x000D_
_x000D_

updated to follow slowly

http://jsfiddle.net/BfLAh/3/

for the orientation , you need to get the current css left and css top and compare with event.pageX and event.pageY , then set the image orientation with

-webkit-transform: rotate(-90deg); 
-moz-transform: rotate(-90deg); 

for the speed , you can set the jquery .animation duration to certain amount.

How to convert column with dtype as object to string in Pandas Dataframe

since strings data types have variable length, it is by default stored as object dtype. If you want to store them as string type, you can do something like this.

df['column'] = df['column'].astype('|S80') #where the max length is set at 80 bytes,

or alternatively

df['column'] = df['column'].astype('|S') # which will by default set the length to the max len it encounters

Making a <button> that's a link in HTML

The 3 easiest ways IMHO are

1: you create an image of a button and put a href around it. (Not a good way, you lose flexibility and will provide a lot of difficulties and problems.)

2 (The easiest one) -> JQuery

<input type="submit" someattribute="http://yoururl/index.php">

  $('button[type=submit] .default').click(function(){
     window.location = $(this).attr("someattribute");
     return false; //otherwise it will send a button submit to the server

   });  

3 (also easy but I prefer previous one):

<INPUT TYPE=BUTTON OnClick="somefunction("http://yoururl");return false" VALUE="somevalue">

$fn.somefunction= function(url) {
    window.location = url;
};

How can I tell jackson to ignore a property for which I don't have control over the source code?

One other possibility is, if you want to ignore all unknown properties, you can configure the mapper as follows:

mapper.configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false);

How do I install Keras and Theano in Anaconda Python on Windows?

In case you want to train CNN's with the theano backend like the Keras mnist_cnn.py example:

You better use theano bleeding edge version. Otherwise there may occur assertion errors.

  • Run Theano bleeding edge
    pip install --upgrade --no-deps git+git://github.com/Theano/Theano.git
  • Run Keras (like 1.0.8 works fine)
    pip install git+git://github.com/fchollet/keras.git

Eclipse - "Workspace in use or cannot be created, chose a different one."

In my case this occurred on a test instance of Eclipse run from my main Eclipse session during plugin development. An error caused the gui to disappear, but didn't totally kill it. Hitting the stop button in the console took care of it.

Why can't I set text to an Android TextView?

In your XML, you had used Textview, But in Java Code you had used EditText instead of TextView. If you change it into TextView you can set Text to to your TextView Object.

text = (TextView) findViewById(R.id.this_is_the_id_of_textview);
text.setText("TEST");

hope it will work.

How to remove trailing whitespace in code, using another script?

If you're looking to tidy up for PEP8, this will trim trailing whitespace for your whole project:

import os

PATH = '/path/to/your/project'

for path, dirs, files in os.walk(PATH):
    for f in files:
        file_name, file_extension = os.path.splitext(f)
        if file_extension == '.py':
            path_name = os.path.join(path, f)
            with open(path_name, 'r') as fh:
                new = [line.rstrip() for line in fh]
            with open(path_name, 'w') as fh:
                [fh.write('%s\n' % line) for line in new]

What is time_t ultimately a typedef to?

It's a 32-bit signed integer type on most legacy platforms. However, that causes your code to suffer from the year 2038 bug. So modern C libraries should be defining it to be a signed 64-bit int instead, which is safe for a few billion years.

continuing execution after an exception is thrown in java

Try this:

try
{
    throw new InvalidEmployeeTypeException();
    input.nextLine();
}
catch(InvalidEmployeeTypeException ex)
{
      //do error handling
}

continue;

Gradle, Android and the ANDROID_HOME SDK location

That question is from November 2013 (while Android Studio was still in Developer Preview mode),

Currently (AS v2.2, Aug-2016) during instalation AS asks to choose the SDK folder (or install on their default) and it automatically applies to which ever project you're opening.

That means any possible workaround or fix is irrelevant as the issue is not reproducible anymore.

Sending emails with Javascript

Here's the way doing it using jQuery and an "element" to click on :

$('#element').click(function(){
    $(location).attr('href', 'mailto:?subject='
                             + encodeURIComponent("This is my subject")
                             + "&body=" 
                             + encodeURIComponent("This is my body")
    );
});

Then, you can get your contents either by feeding it from input fields (ie. using $('#input1').val() or by a server side script with $.get('...'). Have fun

HTML Drag And Drop On Mobile Devices

For vue 3, there is https://github.com/SortableJS/vue.draggable.next

For vue 2, it's https://github.com/SortableJS/Vue.Draggable

The latter you can use like this:

<draggable v-model="myArray" group="people" @start="drag=true" @end="drag=false">
   <div v-for="element in myArray" :key="element.id">{{element.name}}</div>
</draggable>

These are based on sortable.js

Can you style html form buttons with css?

You can achieve your desired through easily by CSS :-

HTML

<input type="submit" name="submit" value="Submit Application" id="submit" />

CSS

#submit {
    background-color: #ccc;
    -moz-border-radius: 5px;
    -webkit-border-radius: 5px;
    border-radius:6px;
    color: #fff;
    font-family: 'Oswald';
    font-size: 20px;
    text-decoration: none;
    cursor: pointer;
    border:none;
}



#submit:hover {
    border: none;
    background:red;
    box-shadow: 0px 0px 1px #777;
}

DEMO

How can I check if a MySQL table exists with PHP?

It was already posted but here it is with PDO (same query)...

$connection = new PDO ( "mysql:host=host_db; dbname=name_db", user_db, pass_db );

if ($connection->query ("DESCRIBE table_name"  )) {
    echo "exist";
} else {
    echo "doesn't exist";
}

Works like a charm for me....

And here's another approach (i think it is slower)...

if ($connection->query ( "SELECT * FROM INFORMATION_SCHEMA.TABLES WHERE table_schema = 'db_name' AND table_name ='tbl_name'" )->fetch ()) {
    echo "exist";
} else {
    echo "doesn't exist";
}

You can also play with this query:

SHOW TABLE STATUS FROM db_name LIKE 'tbl_name'

I think this was suggested to use in the mysql page.

load scripts asynchronously

Have you considered using Fetch Injection? I rolled an open source library called fetch-inject to handle cases like these. Here's what your loader might look like using the lib:

fetcInject([
  'js/jquery-1.6.2.min.js',
  'js/marquee.js',
  'css/marquee.css',
  'css/custom-theme/jquery-ui-1.8.16.custom.css',
  'css/main.css'
]).then(() => {
  'js/jquery-ui-1.8.16.custom.min.js',
  'js/farinspace/jquery.imgpreload.min.js'
})

For backwards compatibility leverage feature detection and fall-back to XHR Injection or Script DOM Elements, or simply inline the tags into the page using document.write.

Where does git config --global get written to?

When is the global .gitconfig file created?

First off, git doesn't automatically create the global config file (.gitconfig) during its installation. The file is not created until it is written to for the first time. If you have never set a system variable, it will not be on your file system. I'm guessing that might be the source of the problem.

One way to ask Git to create it is to request an edit. Doing so will force the file's creation.

git config --global --edit

If you monitor the user's home folder when you issue this command, you will see the .gitconfig file magically appear.

Where is git configuration stored?

Here's a quick rundown of the the name and location of the configuration files associated with the three Git scopes, namely system, global and local:

  • System Git configuration: File named gitconfig located in -git-install-location-/ming<32>/etc
  • Global Git configuraiton: File named .gitconfig located in the user's home folder (C:\Users\git user)
  • Local Git configuration: File named config in the .git folder of the local repo

Of course, seeing is believing, so here's an image showing each file and each location. I pulled the image from an article I wrote on the topic.

Windows Git configuration file locations (TheServerSide.com)

Location of Git configuration files

Are 2 dimensional Lists possible in c#?

This is the easiest way i have found to do it.

List<List<String>> matrix= new List<List<String>>(); //Creates new nested List
matrix.Add(new List<String>()); //Adds new sub List
matrix[0].Add("2349"); //Add values to the sub List at index 0
matrix[0].Add("The Prime of Your Life");
matrix[0].Add("Daft Punk");
matrix[0].Add("Human After All");
matrix[0].Add("3");
matrix[0].Add("2");

To retrieve values is even easier

string title = matrix[0][1]; //Retrieve value at index 1 from sub List at index 0

MySQL select 10 random rows from 600K rows fast

I think here is a simple and yet faster way, I tested it on the live server in comparison with a few above answer and it was faster.

 SELECT * FROM `table_name` WHERE id >= (SELECT FLOOR( MAX(id) * RAND()) FROM `table_name` ) ORDER BY id LIMIT 30; 

//Took 0.0014secs against a table of 130 rows

SELECT * FROM `table_name` WHERE 1 ORDER BY RAND() LIMIT 30

//Took 0.0042secs against a table of 130 rows

 SELECT name
FROM random AS r1 JOIN
   (SELECT CEIL(RAND() *
                 (SELECT MAX(id)
                    FROM random)) AS id)
    AS r2
WHERE r1.id >= r2.id
ORDER BY r1.id ASC
LIMIT 30

//Took 0.0040secs against a table of 130 rows

Detecting iOS orientation change instantly

@vimal answer did not provide solution for me. It seems the orientation is not the current orientation, but from previous orientation. To fix it, I use [[UIDevice currentDevice] orientation]

- (void)orientationChanged:(NSNotification *)notification{
    [self adjustViewsForOrientation:[[UIDevice currentDevice] orientation]];
}

Then

- (void) adjustViewsForOrientation:(UIDeviceOrientation) orientation { ... }

With this code I get the current orientation position.

Show ProgressDialog Android

I am using the following code in one of my current projects where i download data from the internet. It is all inside my activity class.

// ---------------------------- START DownloadFileAsync // -----------------------//
class DownloadFileAsync extends AsyncTask<String, String, String> {

    @Override
    protected void onPreExecute() {
        super.onPreExecute();
        // DIALOG_DOWNLOAD_PROGRESS is defined as 0 at start of class
        showDialog(DIALOG_DOWNLOAD_PROGRESS);
    }

    @Override
    protected String doInBackground(String... urls) {
        try {
            String xmlUrl = urls[0];

            URL u = new URL(xmlUrl);
            HttpURLConnection c = (HttpURLConnection) u.openConnection();
            c.setRequestMethod("GET");
            c.setDoOutput(true);
            c.connect();

            int lengthOfFile = c.getContentLength();

            InputStream in = c.getInputStream();

            byte[] buffer = new byte[1024];
            int len1 = 0;
            long total = 0;

            while ((len1 = in.read(buffer)) > 0) {
                total += len1; // total = total + len1
                publishProgress("" + (int) ((total * 100) / lengthOfFile));
                xmlContent += buffer;
            }
        } catch (Exception e) {
            Log.d("Downloader", e.getMessage());
        }
        return null;
    }

    protected void onProgressUpdate(String... progress) {
        Log.d("ANDRO_ASYNC", progress[0]);
        mProgressDialog.setProgress(Integer.parseInt(progress[0]));
    }

    @Override
    protected void onPostExecute(String unused) {
        dismissDialog(DIALOG_DOWNLOAD_PROGRESS);
    }

}

@Override
protected Dialog onCreateDialog(int id) {
    switch (id) {
    case DIALOG_DOWNLOAD_PROGRESS:
        mProgressDialog = new ProgressDialog(this);
        mProgressDialog.setMessage("Retrieving latest announcements...");
        mProgressDialog.setIndeterminate(false);
        mProgressDialog.setMax(100);
        mProgressDialog.setProgressStyle(ProgressDialog.STYLE_HORIZONTAL);
        mProgressDialog.setCancelable(true);
        mProgressDialog.show();
        return mProgressDialog;
    default:
        return null;
    }

}

Sending the bearer token with axios

If you want to some data after passing token in header so that try this code

const api = 'your api'; 
const token = JSON.parse(sessionStorage.getItem('data'));
const token = user.data.id; /*take only token and save in token variable*/
axios.get(api , { headers: {"Authorization" : `Bearer ${token}`} })
.then(res => {
console.log(res.data);
.catch((error) => {
  console.log(error)
});

Allow only numeric value in textbox using Javascript

// Solution to enter only numeric value in text box

$('#num_of_emp').keyup(function () { 
    this.value = this.value.replace(/[^0-9.]/g,'');
});

for an input box such as :

<input type='text' name='number_of_employee' id='num_of_emp' />

After MySQL install via Brew, I get the error - The server quit without updating PID file

I had the similar issue. But the following commands saved me.

cd /usr/local/Cellar
sudo chown _mysql mysql

Executing a command stored in a variable from PowerShell

Here is yet another way without Invoke-Expression but with two variables (command:string and parameters:array). It works fine for me. Assume 7z.exe is in the system path.

$cmd = '7z.exe'
$prm = 'a', '-tzip', 'c:\temp\with space\test1.zip', 'C:\TEMP\with space\changelog'

& $cmd $prm

If the command is known (7z.exe) and only parameters are variable then this will do

$prm = 'a', '-tzip', 'c:\temp\with space\test1.zip', 'C:\TEMP\with space\changelog'

& 7z.exe $prm

BTW, Invoke-Expression with one parameter works for me, too, e.g. this works

$cmd = '& 7z.exe a -tzip "c:\temp\with space\test2.zip" "C:\TEMP\with space\changelog"'

Invoke-Expression $cmd

P.S. I usually prefer the way with a parameter array because it is easier to compose programmatically than to build an expression for Invoke-Expression.

How to clean project cache in Intellij idea like Eclipse's clean?

If you are using Maven, run this command in your project directory

mvn clean package

Convert Iterator to ArrayList

You can also use IteratorUtils from Apache commons-collections, although it doesn't support generics:

List list = IteratorUtils.toList(iterator);

C# : "A first chance exception of type 'System.InvalidOperationException'"

Consider using System.Windows.Forms.Timer instead of System.Threading.Timer for a GUI application, for timers that are based on the Windows message queue instead of on dedicated threads or the thread pool.

In your scenario, for the purpose of periodic updates of UI, it seems particularly appropriate since you don't really have a background work or long calculation to perform. You just want to do periodic small tasks that have to happen on the UI thread anyway.

oracle sql: update if exists else insert

MERGE doesn't need "multiple tables", but it does need a query as the source. Something like this should work:

MERGE INTO mytable d
USING (SELECT 1 id, 'x' name from dual) s
ON (d.id = s.id)
WHEN MATCHED THEN UPDATE SET d.name = s.name
WHEN NOT MATCHED THEN INSERT (id, name) VALUES (s.id, s.name);

Alternatively you can do this in PL/SQL:

BEGIN
  INSERT INTO mytable (id, name) VALUES (1, 'x');
EXCEPTION
  WHEN DUP_VAL_ON_INDEX THEN
    UPDATE mytable
    SET    name = 'x'
    WHERE id = 1;
END;

mongodb service is not starting up

Here's a weird one, make sure you have consistent spacing in the config file.

For example:

processManagement:
  timeZoneInfo: /usr/share/zoneinfo

security:
    authorization: 'enabled'

If the authorization key has 4 spaces before it, like above and the rest are 2 spaces then it won't work.

Proper Linq where clauses

The first one will be implemented:

Collection.Where(x => x.Age == 10)
          .Where(x => x.Name == "Fido") // applied to the result of the previous
          .Where(x => x.Fat == true)    // applied to the result of the previous

As opposed to the much simpler (and far fasterpresumably faster):

// all in one fell swoop
Collection.Where(x => x.Age == 10 && x.Name == "Fido" && x.Fat == true)

CSS position:fixed inside a positioned element

Seems, css transforms can be used

"‘transform’ property establishes a new local coordinate system at the element",

but ... this is not cross-browser, seems only Opera works correctly

Should import statements always be at the top of a module?

In addition to the excellent answers already given, it's worth noting that the placement of imports is not merely a matter of style. Sometimes a module has implicit dependencies that need to be imported or initialized first, and a top-level import could lead to violations of the required order of execution.

This issue often comes up in Apache Spark's Python API, where you need to initialize the SparkContext before importing any pyspark packages or modules. It's best to place pyspark imports in a scope where the SparkContext is guaranteed to be available.

Can I change the headers of the HTTP request sent by the browser?

ModHeader extension for Google Chrome, is also a good option. You can just set the Headers you want and just enter the URL in the browser, it will automatically take the headers from the extension when you hit the url. Only thing is, it will send headers for each and every URL you will hit so you have to disable or delete it after use.

C# Switch-case string starting with

If the problem domain has some kind of string header concept, this could be modelled as an enum.

switch(GetStringHeader(s))
{
    case StringHeader.ABC: ...
    case StringHeader.QWERTY: ...
    ...
}

StringHeader GetStringHeader(string s)
{
    if (s.StartsWith("ABC")) return StringHeader.ABC;
    ...
}

enum StringHeader { ABC, QWERTY, ... }

Scraping data from website using vba

Other methods were mentioned so let us please acknowledge that, at the time of writing, we are in the 21st century. Let's park the local bus browser opening, and fly with an XMLHTTP GET request (XHR GET for short).

Wiki moment:

XHR is an API in the form of an object whose methods transfer data between a web browser and a web server. The object is provided by the browser's JavaScript environment

It's a fast method for retrieving data that doesn't require opening a browser. The server response can be read into an HTMLDocument and the process of grabbing the table continued from there.

Note that javascript rendered/dynamically added content will not be retrieved as there is no javascript engine running (which there is in a browser).

In the below code, the table is grabbed by its id cr1.

table

In the helper sub, WriteTable, we loop the columns (td tags) and then the table rows (tr tags), and finally traverse the length of each table row, table cell by table cell. As we only want data from columns 1 and 8, a Select Case statement is used specify what is written out to the sheet.


Sample webpage view:

Sample page view


Sample code output:

Code output


VBA:

Option Explicit
Public Sub GetRates()
    Dim html As HTMLDocument, hTable As HTMLTable '<== Tools > References > Microsoft HTML Object Library
    
    Set html = New HTMLDocument
      
    With CreateObject("MSXML2.XMLHTTP")
        .Open "GET", "https://uk.investing.com/rates-bonds/financial-futures", False
        .setRequestHeader "If-Modified-Since", "Sat, 1 Jan 2000 00:00:00 GMT" 'to deal with potential caching
        .send
        html.body.innerHTML = .responseText
    End With
    
    Application.ScreenUpdating = False
    
    Set hTable = html.getElementById("cr1")
    WriteTable hTable, 1, ThisWorkbook.Worksheets("Sheet1")
    
    Application.ScreenUpdating = True
End Sub

Public Sub WriteTable(ByVal hTable As HTMLTable, Optional ByVal startRow As Long = 1, Optional ByVal ws As Worksheet)
    Dim tSection As Object, tRow As Object, tCell As Object, tr As Object, td As Object, r As Long, C As Long, tBody As Object
    r = startRow: If ws Is Nothing Then Set ws = ActiveSheet
    With ws
        Dim headers As Object, header As Object, columnCounter As Long
        Set headers = hTable.getElementsByTagName("th")
        For Each header In headers
            columnCounter = columnCounter + 1
            Select Case columnCounter
            Case 2
                .Cells(startRow, 1) = header.innerText
            Case 8
                .Cells(startRow, 2) = header.innerText
            End Select
        Next header
        startRow = startRow + 1
        Set tBody = hTable.getElementsByTagName("tbody")
        For Each tSection In tBody
            Set tRow = tSection.getElementsByTagName("tr")
            For Each tr In tRow
                r = r + 1
                Set tCell = tr.getElementsByTagName("td")
                C = 1
                For Each td In tCell
                    Select Case C
                    Case 2
                        .Cells(r, 1).Value = td.innerText
                    Case 8
                        .Cells(r, 2).Value = td.innerText
                    End Select
                    C = C + 1
                Next td
            Next tr
        Next tSection
    End With
End Sub

Javascript Drag and drop for touch devices

Old thread I know.......

Problem with the answer of @ryuutatsuo is that it blocks also any input or other element that has to react on 'clicks' (for example inputs), so i wrote this solution. This solution made it possible to use any existing drag and drop library that is based upon mousedown, mousemove and mouseup events on any touch device (or cumputer). This is also a cross-browser solution.

I have tested in on several devices and it works fast (in combination with the drag and drop feature of ThreeDubMedia (see also http://threedubmedia.com/code/event/drag)). It is a jQuery solution so you can use it only with jQuery libs. I have used jQuery 1.5.1 for it because some newer functions don't work properly with IE9 and above (not tested with newer versions of jQuery).

Before you add any drag or drop operation to an event you have to call this function first:

simulateTouchEvents(<object>);

You can also block all components/children for input or to speed up event handling by using the following syntax:

simulateTouchEvents(<object>, true); // ignore events on childs

Here is the code i wrote. I used some nice tricks to speed up evaluating things (see code).

function simulateTouchEvents(oo,bIgnoreChilds)
{
 if( !$(oo)[0] )
  { return false; }

 if( !window.__touchTypes )
 {
   window.__touchTypes  = {touchstart:'mousedown',touchmove:'mousemove',touchend:'mouseup'};
   window.__touchInputs = {INPUT:1,TEXTAREA:1,SELECT:1,OPTION:1,'input':1,'textarea':1,'select':1,'option':1};
 }

$(oo).bind('touchstart touchmove touchend', function(ev)
{
    var bSame = (ev.target == this);
    if( bIgnoreChilds && !bSame )
     { return; }

    var b = (!bSame && ev.target.__ajqmeclk), // Get if object is already tested or input type
        e = ev.originalEvent;
    if( b === true || !e.touches || e.touches.length > 1 || !window.__touchTypes[e.type]  )
     { return; } //allow multi-touch gestures to work

    var oEv = ( !bSame && typeof b != 'boolean')?$(ev.target).data('events'):false,
        b = (!bSame)?(ev.target.__ajqmeclk = oEv?(oEv['click'] || oEv['mousedown'] || oEv['mouseup'] || oEv['mousemove']):false ):false;

    if( b || window.__touchInputs[ev.target.tagName] )
     { return; } //allow default clicks to work (and on inputs)

    // https://developer.mozilla.org/en/DOM/event.initMouseEvent for API
    var touch = e.changedTouches[0], newEvent = document.createEvent("MouseEvent");
    newEvent.initMouseEvent(window.__touchTypes[e.type], true, true, window, 1,
            touch.screenX, touch.screenY,
            touch.clientX, touch.clientY, false,
            false, false, false, 0, null);

    touch.target.dispatchEvent(newEvent);
    e.preventDefault();
    ev.stopImmediatePropagation();
    ev.stopPropagation();
    ev.preventDefault();
});
 return true;
}; 

What it does: At first, it translates single touch events into mouse events. It checks if an event is caused by an element on/in the element that must be dragged around. If it is an input element like input, textarea etc, it skips the translation, or if a standard mouse event is attached to it it will also skip a translation.

Result: Every element on a draggable element is still working.

Happy coding, greetz, Erwin Haantjes

The view 'Index' or its master was not found.

Where this error only occurs when deployed to a web server then the issue could be because the views are not being deployed correctly.

An example of how this can happen is if the build action for the views is set to None rather than Content.

A way to check that the views are deployed correctly is to navigate to the physical path for the site on the web server and confirm that the views are present.

How do I create an executable in Visual Studio 2013 w/ C++?

All executable files from Visual Studio should be located in the debug folder of your project, e.g:

Visual Studio Directory: c:\users\me\documents\visual studio

Then the project which was called 'hello world' would be in the directory:

c:\users\me\documents\visual studio\hello world

And your exe would be located in:

c:\users\me\documents\visual studio\hello world\Debug\hello world.exe

Note the exe being named the same as the project.

Otherwise, you could publish it to a specified folder of your choice which comes with an installation, which would be good if you wanted to distribute it quickly

EDIT:

Everytime you build your project in VS, the exe is updated with the new one according to the code (as long as it builds without errors). When you publish it, you can choose the location, aswell as other factors, and the setup exe will be in that location, aswell as some manifest files and other files about the project.

How to SELECT based on value of another SELECT

You can calculate the total (and from that the desired percentage) by using a subquery in the FROM clause:

SELECT Name,
       SUM(Value) AS "SUM(VALUE)",
       SUM(Value) / totals.total AS "% of Total"
FROM   table1,
       (
           SELECT Name,
                  SUM(Value) AS total
           FROM   table1
           GROUP BY Name
       ) AS totals
WHERE  table1.Name = totals.Name
AND    Year BETWEEN 2000 AND 2001
GROUP BY Name;

Note that the subquery does not have the WHERE clause filtering the years.

How to handle screen orientation change when progress dialog and background thread active?

I met the same problem. My activity needs to parse some data from a URL and it's slow. So I create a thread to do so, then show a progress dialog. I let the thread post a message back to UI thread via Handler when it's finished. In Handler.handleMessage, I get the data object (ready now) from thread and populate it to UI. So it's very similar to your example.

After a lot of trial and error it looks like I found a solution. At least now I can rotate screen at any moment, before or after the thread is done. In all tests, the dialog is properly closed and all behaviors are as expected.

What I did is shown below. The goal is to fill my data model (mDataObject) and then populate it to UI. Should allow screen rotation at any moment without surprise.

class MyActivity {

    private MyDataObject mDataObject = null;
    private static MyThread mParserThread = null; // static, or make it singleton

    OnCreate() {
        ...
        Object retained = this.getLastNonConfigurationInstance();
        if(retained != null) {
            // data is already completely obtained before config change
            // by my previous self.
            // no need to create thread or show dialog at all
            mDataObject = (MyDataObject) retained;
            populateUI();
        } else if(mParserThread != null && mParserThread.isAlive()){
            // note: mParserThread is a static member or singleton object.
            // config changed during parsing in previous instance. swap handler
            // then wait for it to finish.
            mParserThread.setHandler(new MyHandler());
        } else {
            // no data and no thread. likely initial run
            // create thread, show dialog
            mParserThread = new MyThread(..., new MyHandler());
            mParserThread.start();
            showDialog(DIALOG_PROGRESS);
        }
    }

    // http://android-developers.blogspot.com/2009/02/faster-screen-orientation-change.html
    public Object onRetainNonConfigurationInstance() {
        // my future self can get this without re-downloading
        // if it's already ready.
        return mDataObject;
    }

    // use Activity.showDialog instead of ProgressDialog.show
    // so the dialog can be automatically managed across config change
    @Override
    protected Dialog onCreateDialog(int id) {
        // show progress dialog here
    }

    // inner class of MyActivity
    private class MyHandler extends Handler {
        public void handleMessage(msg) {
            mDataObject = mParserThread.getDataObject();
            populateUI();
            dismissDialog(DIALOG_PROGRESS);
        }
    }
}

class MyThread extends Thread {
    Handler mHandler;
    MyDataObject mDataObject;

    // constructor with handler param
    public MyHandler(..., Handler h) {
        ...
        mHandler = h;
    }

    public void setHandler(Handler h) { mHandler = h; } // for handler swapping after config change
    public MyDataObject getDataObject() { return mDataObject; } // return data object (completed) to caller

    public void run() {
        mDataObject = new MyDataObject();
        // do the lengthy task to fill mDataObject with data
        lengthyTask(mDataObject);
        // done. notify activity
        mHandler.sendEmptyMessage(0); // tell activity: i'm ready. come pick up the data.
    }
}

That's what works for me. I don't know if this is the "correct" method as designed by Android -- they claim this "destroy/recreate activity during screen rotation" actually makes things easier, so I guess it shouldn't be too tricky.

Let me know if you see a problem in my code. As said above I don't really know if there is any side effect.

How to increase MySQL connections(max_connections)?

If you need to increase MySQL Connections without MySQL restart do like below

mysql> show variables like 'max_connections';
+-----------------+-------+
| Variable_name   | Value |
+-----------------+-------+
| max_connections | 100   |
+-----------------+-------+
1 row in set (0.00 sec)

mysql> SET GLOBAL max_connections = 150;
Query OK, 0 rows affected (0.00 sec)

mysql> show variables like 'max_connections';
+-----------------+-------+
| Variable_name   | Value |
+-----------------+-------+
| max_connections | 150   |
+-----------------+-------+
1 row in set (0.00 sec)

These settings will change at MySQL Restart.


For permanent changes add below line in my.cnf and restart MySQL

max_connections = 150

Reading the selected value from asp:RadioButtonList using jQuery

Andrew Bullock solution works just fine, I just wanted to show you mine and add a warning.

//Works great

$('#<%= radBuffetCapacity.ClientID %> input').click(function (e) {
   var val = $('#<%= radBuffetCapacity.ClientID %>').find('input:checked').val();
   //Do whatever
});

//Warning - works in firefox but not IE8 .. used this for some time before a noticing that it didnt work in IE8... used to everything working in all browsers with jQuery when working in one.

$('#<%= radBuffetCapacity.ClientID %>').change(function (e) {
   var val = $('#<%= radBuffetCapacity.ClientID %>').find('input:checked').val();
   //Do whatever
});

CSS Calc Viewport Units Workaround?

<div>It's working fine.....</div>

div
{
     height: calc(100vh - 8vw);
    background: #000;
    overflow:visible;
    color: red;
}

Check here this css code right now support All browser without Opera

just check this

Live

see Live preview by jsfiddle

See Live preview by codepen.io

jQuery addClass onClick

Try to make your css more specific so that the new (green) style is more specific than the previous one, so that it worked for me!

For example, you might use in css:

button:active {/*your style here*/}

Instead of (probably not working):

.active {/*style*/} (.active is not a pseudo-class)

Hope it helps!

Switch tabs using Selenium WebDriver with Java

    public void switchToNextTab() {
        ArrayList<String> tab = new ArrayList<>(driver.getWindowHandles());
        driver.switchTo().window(tab.get(1));
    }
    
    public void closeAndSwitchToNextTab() {
        driver.close();
        ArrayList<String> tab = new ArrayList<>(driver.getWindowHandles());
        driver.switchTo().window(tab.get(1));
    }

    public void switchToPreviousTab() {
        ArrayList<String> tab = new ArrayList<>(driver.getWindowHandles());
        driver.switchTo().window(tab.get(0));
    }

    public void closeTabAndReturn() {
        driver.close();
        ArrayList<String> tab = new ArrayList<>(driver.getWindowHandles());
        driver.switchTo().window(tab.get(0));
    }

    public void switchToPreviousTabAndClose() {
        ArrayList<String> tab = new ArrayList<>(driver.getWindowHandles());
        driver.switchTo().window(tab.get(1));
        driver.close();
    }

Dialog with transparent background in Android

Try this in your code:

getWindow().setBackgroundDrawableResource(android.R.color.transparent);

it will definately working...in my case...! my frend

C# DataTable.Select() - How do I format the filter criteria to include null?

The way to check for null is to check for it:

DataRow[] myResultSet = myDataTable.Select("[COLUMN NAME] is null");

You can use and and or in the Select statement.

How to horizontally align ul to center of div?

Make the left and right margins of your UL auto and assign it a width:

#headermenu ul {
    margin: 0 auto;
    width: 620px;
}

Edit: As kleinfreund has suggested, you can also center align the container and give the ul an inline-block display, but you then also have to give the LIs either a left float or an inline display.

#headermenu { 
    text-align: center;
}
#headermenu ul { 
    display: inline-block;
}
#headermenu ul li {
    float: left; /* or display: inline; */
}

Remove all special characters, punctuation and spaces from string

Shorter way :

import re
cleanString = re.sub('\W+','', string )

If you want spaces between words and numbers substitute '' with ' '

How to extract .war files in java? ZIP vs JAR

Just rename the .war into .jar and unzip it using Winrar (or any other archive manager).

Fatal error: Call to undefined function: ldap_connect()

  • [Your Drive]:\xampp\php\php.ini: In this file uncomment the following line:

    extension=php_ldap.dll

  • Move the file: libsasl.dll, from [Your Drive]:\xampp\php to [Your Drive]:\xampp\apache\bin Restart Apache. You can now use functions of the LDAP Module!

Spring not autowiring in unit tests with JUnit

You need to use the Spring JUnit runner in order to wire in Spring beans from your context. The code below assumes that you have a application context called testContest.xml available on the test classpath.

import org.hibernate.SessionFactory;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
import org.springframework.transaction.annotation.Transactional;

import java.sql.SQLException;

import static org.hamcrest.MatcherAssert.assertThat;
import static org.hamcrest.Matchers.startsWith;

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(locations = {"classpath*:**/testContext.xml"})
@Transactional
public class someDaoTest {

    @Autowired
    protected SessionFactory sessionFactory;

    @Test
    public void testDBSourceIsCorrect() throws SQLException {
        String databaseProductName = sessionFactory.getCurrentSession()
                .connection()
                .getMetaData()
                .getDatabaseProductName();
        assertThat("Test container is pointing at the wrong DB.", databaseProductName, startsWith("HSQL"));
    }
}

Note: This works with Spring 2.5.2 and Hibernate 3.6.5

Apache is "Unable to initialize module" because of module's and PHP's API don't match after changing the PHP configuration

Here is the one that works with php 5.5. Download xampp 1.8.3 from here and download memcache dll from here

Node.js connect only works on localhost

Binding to 0.0.0.0 is half the battle. There is an ip firewall (different from the one in system preferences) that blocks TCP ports. Hence port must be unblocked there as well by doing:

sudo ipfw add <PORT NUMBER> allow tcp from any to any

Mongoose.js: Find user by username LIKE value

Here my code with expressJS:

router.route('/wordslike/:word')
    .get(function(request, response) {
            var word = request.params.word;       
            Word.find({'sentence' : new RegExp(word, 'i')}, function(err, words){
               if (err) {response.send(err);}
               response.json(words);
            });
         });

How to break lines at a specific character in Notepad++?

I have no idea how it can work automatically, but you can copy "], " together with new line and then use replace function.

Integer division with remainder in JavaScript?

 function integerDivison(dividend, divisor){
    
        this.Division  = dividend/divisor;
        this.Quotient = Math.floor(dividend/divisor);
         this.Remainder = dividend%divisor;
        this.calculate = ()=>{
            return {Value:this.Division,Quotient:this.Quotient,Remainder:this.Remainder};
        }
         
    }

  var divide = new integerDivison(5,2);
  console.log(divide.Quotient)      //to get Quotient of two value 
  console.log(divide.division)     //to get Floating division of two value 
  console.log(divide.Remainder)     //to get Remainder of two value 
  console.log(divide.calculate())   //to get object containing all the values

Setting environment variable in react-native?

In my opinion the best option is to use react-native-config. It supports 12 factor.

I found this package extremely useful. You can set multiple environments, e.g. development, staging, production.

In case of Android, variables are available also in Java classes, gradle, AndroidManifest.xml etc. In case of iOS, variables are available also in Obj-C classes, Info.plist.

You just create files like

  • .env.development
  • .env.staging
  • .env.production

You fill these files with key, values like

API_URL=https://myapi.com
GOOGLE_MAPS_API_KEY=abcdefgh

and then just use it:

import Config from 'react-native-config'

Config.API_URL  // 'https://myapi.com'
Config.GOOGLE_MAPS_API_KEY  // 'abcdefgh'

If you want to use different environments, you basically set ENVFILE variable like this:

ENVFILE=.env.staging react-native run-android

or for assembling app for production (android in my case):

cd android && ENVFILE=.env.production ./gradlew assembleRelease

How do I get the latest version of my code?

I understand you want to trash your local changes and pull down what's on your remote?

If all else fails, and if you're (quite understandably) scared of "reset", the simplest thing is just to clone origin into a new directory and trash your old one.

Rollback to last git commit

If you want to remove newly added contents and files which are already staged (so added to the index) then you use:

git reset --hard

If you want to remove also your latest commit (is the one with the message "blah") then better to use:

git reset --hard HEAD^

To remove the untracked files (so new files not yet added to the index) and folders use:

git clean --force -d

Regular expression to limit number of characters to 10

pattern: /[\w\W]{1,10}/g

I used this expression for my case, it includes all the characters available in the text.

How can I get the length of text entered in a textbox using jQuery?

You need to only grab the element with an appropriate jQuery selector and then the .val() method to get the string contained in the input textbox and then call the .length on that string.

$('input:text').val().length

However, be warned that if the selector matches multiple inputs, .val() will only return the value of the first textbox. You can also change the selector to get a more specific element but keep the :text to ensure it's an input textbox.

On another note, to get the length of a string contained in another, non-input element, you can use the .text() function to get the string and then use .length on that string to find its length.

ng-if, not equal to?

There are pretty good solutions here but they don't help to understand why the problem actually happens.

But it's very simple, you just need to understand how logic OR || works. Whole expression will evaluate to true when either of its sides evaluates to true.

Now let's look at your case. Assume whole details.Payment[0].Status is Status and it's a number for brevity. Then we have Status != 0 || Status != 1 || ....

Imagine Status = 1:

( 1 != 0 || 1 != 1 || ... ) =
(  true  || false  || ... ) =
(       true       || ... ) = ... = true

Now imagine Status = 0:

( 0 != 0 || 0 != 1 || ... ) =
( false  ||  true  || ... ) =
(       true       || ... ) = ... = true

As you it doesn't even matter what you have as ... as logical OR of first two expressions gives you true which will be the result of the full expression.

What you actually need is logical AND && that will be true only if both its sides are true.

Python update a key in dict if it doesn't exist

With the following you can insert multiple values and also have default values but you're creating a new dictionary.

d = {**{ key: value }, **default_values}

I've tested it with the most voted answer and on average this is faster as it can be seen in the following example, .

Speed test comparing a for loop based method with a dict comprehension with unpack operator Speed test comparing a for loop based method with a dict comprehension with unpack operator method.

if no copy (d = default_vals.copy()) is made on the first case then the most voted answer would be faster once we reach orders of magnitude of 10**5 and greater. Memory footprint of both methods are the same.

Generate pdf from HTML in div using Javascript

i use jspdf and html2canvas for css rendering and i export content of specific div as this is my code

$(document).ready(function () {
    let btn=$('#c-oreder-preview');
    btn.text('download');
    btn.on('click',()=> {

        $('#c-invoice').modal('show');
        setTimeout(function () {
            html2canvas(document.querySelector("#c-print")).then(canvas => {
                //$("#previewBeforeDownload").html(canvas);
                var imgData = canvas.toDataURL("image/jpeg",1);
                var pdf = new jsPDF("p", "mm", "a4");
                var pageWidth = pdf.internal.pageSize.getWidth();
                var pageHeight = pdf.internal.pageSize.getHeight();
                var imageWidth = canvas.width;
                var imageHeight = canvas.height;

                var ratio = imageWidth/imageHeight >= pageWidth/pageHeight ? pageWidth/imageWidth : pageHeight/imageHeight;
                //pdf = new jsPDF(this.state.orientation, undefined, format);
                pdf.addImage(imgData, 'JPEG', 0, 0, imageWidth * ratio, imageHeight * ratio);
                pdf.save("invoice.pdf");
                //$("#previewBeforeDownload").hide();
                $('#c-invoice').modal('hide');
            });
        },500);

        });
});

Get values from other sheet using VBA

Maybe you can use the script i am using to retrieve a certain cell value from another sheet back to a specific sheet.

Sub reviewRow()
Application.ScreenUpdating = False
Results = MsgBox("Do you want to View selected row?", vbYesNo, "")
If Results = vbYes And Range("C10") > 1 Then
i = Range("C10") //this is where i put the row number that i want to retrieve or review that can be changed as needed
Worksheets("Sheet1").Range("C6") = Worksheets("Sheet2").Range("C" & i) //sheet names can be changed as necessary
End if
Application.ScreenUpdating = True
End Sub

You can make a form using this and personalize it as needed.

How do Python functions handle the types of the parameters that you pass in?

Many languages have variables, which are of a specific type and have a value. Python does not have variables; it has objects, and you use names to refer to these objects.

In other languages, when you say:

a = 1

then a (typically integer) variable changes its contents to the value 1.

In Python,

a = 1

means “use the name a to refer to the object 1”. You can do the following in an interactive Python session:

>>> type(1)
<type 'int'>

The function type is called with the object 1; since every object knows its type, it's easy for type to find out said type and return it.

Likewise, whenever you define a function

def funcname(param1, param2):

the function receives two objects, and names them param1 and param2, regardless of their types. If you want to make sure the objects received are of a specific type, code your function as if they are of the needed type(s) and catch the exceptions that are thrown if they aren't. The exceptions thrown are typically TypeError (you used an invalid operation) and AttributeError (you tried to access an inexistent member (methods are members too) ).

Group by in LINQ

Absolutely - you basically want:

var results = from p in persons
              group p.car by p.PersonId into g
              select new { PersonId = g.Key, Cars = g.ToList() };

Or as a non-query expression:

var results = persons.GroupBy(
    p => p.PersonId, 
    p => p.car,
    (key, g) => new { PersonId = key, Cars = g.ToList() });

Basically the contents of the group (when viewed as an IEnumerable<T>) is a sequence of whatever values were in the projection (p.car in this case) present for the given key.

For more on how GroupBy works, see my Edulinq post on the topic.

(I've renamed PersonID to PersonId in the above, to follow .NET naming conventions.)

Alternatively, you could use a Lookup:

var carsByPersonId = persons.ToLookup(p => p.PersonId, p => p.car);

You can then get the cars for each person very easily:

// This will be an empty sequence for any personId not in the lookup
var carsForPerson = carsByPersonId[personId];

How to divide two columns?

Presumably, those columns are integer columns - which will be the reason as the result of the calculation will be of the same type.

e.g. if you do this:

SELECT 1 / 2

you will get 0, which is obviously not the real answer. So, convert the values to e.g. decimal and do the calculation based on that datatype instead.

e.g.

SELECT CAST(1 AS DECIMAL) / 2

gives 0.500000

Clicking the back button twice to exit an activity

You can also use the visibility of a Toast, so you don't need that Handler/postDelayed ultra solution.

Toast doubleBackButtonToast;

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

    doubleBackButtonToast = Toast.makeText(this, "Double tap back to exit.", Toast.LENGTH_SHORT);
}

@Override
public void onBackPressed() {
    if (doubleBackButtonToast.getView().isShown()) {
        super.onBackPressed();
    }

    doubleBackButtonToast.show();
}

Can not find the tag library descriptor for "http://java.sun.com/jsp/jstl/core"

This is a very common error while working on JSTL.

To solve this error simply :-

  1. Download jstl-1.1.2.jar and standard-1.1.2.jar
  2. And then just paste them in lib folder under WEB-INF of your Dynamic Web App project.

You will find the error has gone now!

Hope this helps.

Volatile vs Static in Java

If we declare a variable as static, there will be only one copy of the variable. So, whenever different threads access that variable, there will be only one final value for the variable(since there is only one memory location allocated for the variable).

If a variable is declared as volatile, all threads will have their own copy of the variable but the value is taken from the main memory.So, the value of the variable in all the threads will be the same.

So, in both cases, the main point is that the value of the variable is same across all threads.

set font size in jquery

$("#"+styleTarget).css('font-size', newFontSize);

Bootstrap full-width text-input within inline-form

The bootstrap docs says about this:

Requires custom widths Inputs, selects, and textareas are 100% wide by default in Bootstrap. To use the inline form, you'll have to set a width on the form controls used within.

The default width of 100% as all form elements gets when they got the class form-control didn't apply if you use the form-inline class on your form.

You could take a look at the bootstrap.css (or .less, whatever you prefer) where you will find this part:

.form-inline {

  // Kick in the inline
  @media (min-width: @screen-sm-min) {
    // Inline-block all the things for "inline"
    .form-group {
      display: inline-block;
      margin-bottom: 0;
      vertical-align: middle;
    }

    // In navbar-form, allow folks to *not* use `.form-group`
    .form-control {
      display: inline-block;
      width: auto; // Prevent labels from stacking above inputs in `.form-group`
      vertical-align: middle;
    }
    // Input groups need that 100% width though
    .input-group > .form-control {
      width: 100%;
    }

    [...]
  }
}

Maybe you should take a look at input-groups, since I guess they have exactly the markup you want to use (working fiddle here):

<div class="row">
   <div class="col-lg-12">
    <div class="input-group input-group-lg">
      <input type="text" class="form-control input-lg" id="search-church" placeholder="Your location (City, State, ZIP)">
      <span class="input-group-btn">
        <button class="btn btn-default btn-lg" type="submit">Search</button>
      </span>
    </div>
  </div>
</div>

Read Session Id using Javascript

As far as I know, a browser session doesn't have an id.

If you mean the server session, that is usually stored in a cookie. The cookie that ASP.NET stores, for example, is named "ASP.NET_SessionId".

HTML button to NOT submit form

Another option that worked for me was to add onsubmit="return false;" to the form tag.

<form onsubmit="return false;">

Semantically probably not as good a solution as the above methods of changing the button type, but seems to be an option if you just want a form element the won't submit.

Spring CORS No 'Access-Control-Allow-Origin' header is present

We had the same issue and we resolved it using Spring's XML configuration as below:

Add this in your context xml file

<mvc:cors>
    <mvc:mapping path="/**"
        allowed-origins="*"
        allowed-headers="Content-Type, Access-Control-Allow-Origin, Access-Control-Allow-Headers, Authorization, X-Requested-With, requestId, Correlation-Id"
        allowed-methods="GET, PUT, POST, DELETE"/>
</mvc:cors>

what is the difference between GROUP BY and ORDER BY in sql

ORDER BY alters the order in which items are returned.

GROUP BY will aggregate records by the specified columns which allows you to perform aggregation functions on non-grouped columns (such as SUM, COUNT, AVG, etc).

TABLE:
ID NAME
1  Peter
2  John
3  Greg
4  Peter

SELECT *
FROM TABLE
ORDER BY NAME

= 
3 Greg
2 John
1 Peter
4 Peter

SELECT Count(ID), NAME
FROM TABLE
GROUP BY NAME

= 
1 Greg
1 John 
2 Peter

SELECT NAME
FROM TABLE
GROUP BY NAME
HAVING Count(ID) > 1

=
Peter

How do I get whole and fractional parts from double in JSP/Java?

Integer part gets from simple casting and for fractional - string splitting:

double value = 123.004567890

int integerPart = (int) value; // 123

int fractionPart = 
  Integer.valueOf(String.valueOf(value)
      .split(".")[1]); // 004567890

/**
* To control zeroes omitted from start after parsing.
*/
int decimals =
  String.valueOf(value)
      .split(".")[1].length(); // 9

Hibernate, @SequenceGenerator and allocationSize

After digging into hibernate source code and Below configuration goes to Oracle db for the next value after 50 inserts. So make your INST_PK_SEQ increment 50 each time it is called.

Hibernate 5 is used for below strategy

Check also below http://docs.jboss.org/hibernate/orm/5.1/userguide/html_single/Hibernate_User_Guide.html#identifiers-generators-sequence

@Id
@Column(name = "ID")
@GenericGenerator(name = "INST_PK_SEQ", 
strategy = "org.hibernate.id.enhanced.SequenceStyleGenerator",
parameters = {
        @org.hibernate.annotations.Parameter(
                name = "optimizer", value = "pooled-lo"),
        @org.hibernate.annotations.Parameter(
                name = "initial_value", value = "1"),
        @org.hibernate.annotations.Parameter(
                name = "increment_size", value = "50"),
        @org.hibernate.annotations.Parameter(
                name = SequenceStyleGenerator.SEQUENCE_PARAM, value = "INST_PK_SEQ"),
    }
)
@GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "INST_PK_SEQ")
private Long id;

Detect merged cells in VBA Excel with MergeArea

There are several helpful bits of code for this.

Place your cursor in a merged cell and ask these questions in the Immidiate Window:

Is the activecell a merged cell?

? Activecell.Mergecells
 True

How many cells are merged?

? Activecell.MergeArea.Cells.Count
 2

How many columns are merged?

? Activecell.MergeArea.Columns.Count
 2

How many rows are merged?

? Activecell.MergeArea.Rows.Count
  1

What's the merged range address?

? activecell.MergeArea.Address
  $F$2:$F$3

python filter list of dictionaries based on key value

You can try a list comp

>>> exampleSet = [{'type':'type1'},{'type':'type2'},{'type':'type2'}, {'type':'type3'}]
>>> keyValList = ['type2','type3']
>>> expectedResult = [d for d in exampleSet if d['type'] in keyValList]
>>> expectedResult
[{'type': 'type2'}, {'type': 'type2'}, {'type': 'type3'}]

Another way is by using filter

>>> list(filter(lambda d: d['type'] in keyValList, exampleSet))
[{'type': 'type2'}, {'type': 'type2'}, {'type': 'type3'}]

Display List in a View MVC

Your action method considers model type asList<string>. But, in your view you are waiting for IEnumerable<Standings.Models.Teams>. You can solve this problem with changing the model in your view to List<string>.

But, the best approach would be to return IEnumerable<Standings.Models.Teams> as a model from your action method. Then you haven't to change model type in your view.

But, in my opinion your models are not correctly implemented. I suggest you to change it as:

public class Team
{
    public int Position { get; set; }
    public string HomeGround {get; set;}
    public string NickName {get; set;}
    public int Founded { get; set; }
    public string Name { get; set; }
}

Then you must change your action method as:

public ActionResult Index()
{
    var model = new List<Team>();

    model.Add(new Team { Name = "MU"});
    model.Add(new Team { Name = "Chelsea"});
    ...

    return View(model);
}

And, your view:

@model IEnumerable<Standings.Models.Team>

@{
     ViewBag.Title = "Standings";
}

@foreach (var item in Model)
{
    <div>
        @item.Name
        <hr />
    </div>
}

Smooth GPS data

As for least squares fit, here are a couple other things to experiment with:

  1. Just because it's least squares fit doesn't mean that it has to be linear. You can least-squares-fit a quadratic curve to the data, then this would fit a scenario in which the user is accelerating. (Note that by least squares fit I mean using the coordinates as the dependent variable and time as the independent variable.)

  2. You could also try weighting the data points based on reported accuracy. When the accuracy is low weight those data points lower.

  3. Another thing you might want to try is rather than display a single point, if the accuracy is low display a circle or something indicating the range in which the user could be based on the reported accuracy. (This is what the iPhone's built-in Google Maps application does.)

Shell command to tar directory excluding certain files/folders

You can have multiple exclude options for tar so

$ tar --exclude='./folder' --exclude='./upload/folder2' -zcvf /backup/filename.tgz .

etc will work. Make sure to put --exclude before the source and destination items.

how to pass parameter from @Url.Action to controller function

you can pass it this way :

Url.Action("CreatePerson", "Person", new RouteValueDictionary(new { id = id }));

OR can also pass this way

Url.Action("CreatePerson", "Person", new { id = id });

Eclipse - debugger doesn't stop at breakpoint

One additional comment regarding Vineet Reynolds answer.

I found out that I had to set -XX:+UseParallelGC in eclipse.ini

I setup the virtual machine (vm) arguments as follows

-vmargs
-Dosgi.requiredJavaVersion=1.7
-Xms512m
-Xmx1024m
-XX:+UseParallelGC
-XX:PermSize=256M
-XX:MaxPermSize=512M

that solved the issue.

Change link color of the current page with CSS

It is possible to achieve this without having to modify each page individually (adding a 'current' class to a specific link), but still without JS or a server-side script. This uses the :target pseudo selector, which relies on #someid appearing in the addressbar.

<!DOCTYPE>
<html>
<head>
    <title>Some Title</title>
<style>
:target {
    background-color: yellow;
}
</style>
</head>
<body>
<ul>
    <li><a id="news" href="news.html#news">News</a></li>
    <li><a id="games" href="games.html#games">Games</a></li>
    <li><a id="science" href="science.html#science">Science</a></li>
</ul>
<h1>Stuff about science</h1>
<p>lorem ipsum blah blah</p>
</body>
</html>

There are a couple of restrictions:

  • If the page wasn't navigated to using one of these links it won't be coloured;
  • The ids need to occur at the top of the page otherwise the page will jump down a bit when visited.

As long as any links to these pages include the id, and the navbar is at the top, it shouldn't be a problem.


Other in-page links (bookmarks) will also cause the colour to be lost.