Programs & Examples On #Private constructor

private constructor

One common use is in the singleton pattern where you want only one instance of the class to exist. In that case, you can provide a static method which does the instantiation of the object. This way the number of objects instantiated of a particular class can be controlled.

Vue component event after render

updated might be what you're looking for. https://vuejs.org/v2/api/#updated

Get name of property as a string

it's how I implemented it , the reason behind is if the class that you want to get the name from it's member is not static then you need to create an instanse of that and then get the member's name. so generic here comes to help

public static string GetName<TClass>(Expression<Func<TClass, object>> exp)
{
    MemberExpression body = exp.Body as MemberExpression;

    if (body == null)
    {
         UnaryExpression ubody = (UnaryExpression)exp.Body;
         body = ubody.Operand as MemberExpression;
    }

     return body.Member.Name;
}

the usage is like this

var label = ClassExtension.GetName<SomeClass>(x => x.Label); //x is refering to 'SomeClass'

Why does git revert complain about a missing -m option?

Say the other guy created bar on top of foo, but you created baz in the meantime and then merged, giving a history of

$ git lola
*   2582152 (HEAD, master) Merge branch 'otherguy'
|\  
| * c7256de (otherguy) bar
* | b7e7176 baz
|/  
* 9968f79 foo

Note: git lola is a non-standard but useful alias.

No dice with git revert:

$ git revert HEAD
fatal: Commit 2582152... is a merge but no -m option was given.

Charles Bailey gave an excellent answer as usual. Using git revert as in

$ git revert --no-edit -m 1 HEAD
[master e900aad] Revert "Merge branch 'otherguy'"
 0 files changed, 0 insertions(+), 0 deletions(-)
 delete mode 100644 bar

effectively deletes bar and produces a history of

$ git lola
* e900aad (HEAD, master) Revert "Merge branch 'otherguy'"
*   2582152 Merge branch 'otherguy'
|\  
| * c7256de (otherguy) bar
* | b7e7176 baz
|/  
* 9968f79 foo

But I suspect you want to throw away the merge commit:

$ git reset --hard HEAD^
HEAD is now at b7e7176 baz

$ git lola
* b7e7176 (HEAD, master) baz
| * c7256de (otherguy) bar
|/  
* 9968f79 foo

As documented in the git rev-parse manual

<rev>^, e.g. HEAD^, v1.5.1^0
A suffix ^ to a revision parameter means the first parent of that commit object. ^<n> means the n-th parent (i.e. <rev>^ is equivalent to <rev>^1). As a special rule, <rev>^0 means the commit itself and is used when <rev> is the object name of a tag object that refers to a commit object.

so before invoking git reset, HEAD^ (or HEAD^1) was b7e7176 and HEAD^2 was c7256de, i.e., respectively the first and second parents of the merge commit.

Be careful with git reset --hard because it can destroy work.

Rename multiple files by replacing a particular pattern in the filenames using a shell script

An example to help you get off the ground.

for f in *.jpg; do mv "$f" "$(echo "$f" | sed s/IMG/VACATION/)"; done

In this example, I am assuming that all your image files contain the string IMG and you want to replace IMG with VACATION.

The shell automatically evaluates *.jpg to all the matching files.

The second argument of mv (the new name of the file) is the output of the sed command that replaces IMG with VACATION.

If your filenames include whitespace pay careful attention to the "$f" notation. You need the double-quotes to preserve the whitespace.

VBA: Convert Text to Number

I had this problem earlier and this was my solution.

With Worksheets("Sheet1").Columns(5)
    .NumberFormat = "0"
    .Value = .Value
End With

How to check version of a CocoaPods framework

pod --version

to get the version of installed pod

Javascript - check array for value

This should do it:

for (var i = 0; i < bank_holidays.length; i++) {
    if (bank_holidays[i] === '06/04/2012') {
        alert('LOL');
    }
}

jsFiddle

Oracle (ORA-02270) : no matching unique or primary key for this column-list error

The data type in the Job table (Varchar2(20)) does not match the data type in the USER table (NUMBER NOT NULL).

UnicodeEncodeError: 'ascii' codec can't encode character u'\xe9' in position 7: ordinal not in range(128)

You need to encode Unicode explicitly before writing to a file, otherwise Python does it for you with the default ASCII codec.

Pick an encoding and stick with it:

f.write(printinfo.encode('utf8') + '\n')

or use io.open() to create a file object that'll encode for you as you write to the file:

import io

f = io.open(filename, 'w', encoding='utf8')

You may want to read:

before continuing.

How to remove specific value from array using jQuery

There is no native way to do this in Javascript. You could use a library or write a small function to do this instead: http://ejohn.org/blog/javascript-array-remove/

Aren't promises just callbacks?

Promises are not callbacks. A promise represents the future result of an asynchronous operation. Of course, writing them the way you do, you get little benefit. But if you write them the way they are meant to be used, you can write asynchronous code in a way that resembles synchronous code and is much more easy to follow:

api().then(function(result){
    return api2();
}).then(function(result2){
    return api3();
}).then(function(result3){
     // do work
});

Certainly, not much less code, but much more readable.

But this is not the end. Let's discover the true benefits: What if you wanted to check for any error in any of the steps? It would be hell to do it with callbacks, but with promises, is a piece of cake:

api().then(function(result){
    return api2();
}).then(function(result2){
    return api3();
}).then(function(result3){
     // do work
}).catch(function(error) {
     //handle any error that may occur before this point
});

Pretty much the same as a try { ... } catch block.

Even better:

api().then(function(result){
    return api2();
}).then(function(result2){
    return api3();
}).then(function(result3){
     // do work
}).catch(function(error) {
     //handle any error that may occur before this point
}).then(function() {
     //do something whether there was an error or not
     //like hiding an spinner if you were performing an AJAX request.
});

And even better: What if those 3 calls to api, api2, api3 could run simultaneously (e.g. if they were AJAX calls) but you needed to wait for the three? Without promises, you should have to create some sort of counter. With promises, using the ES6 notation, is another piece of cake and pretty neat:

Promise.all([api(), api2(), api3()]).then(function(result) {
    //do work. result is an array contains the values of the three fulfilled promises.
}).catch(function(error) {
    //handle the error. At least one of the promises rejected.
});

Hope you see Promises in a new light now.

PHP compare two arrays and get the matched values not the difference

I think the better answer for this questions is

array_diff() 

because it Compares array against one or more other arrays and returns the values in array that are not present in any of the other arrays.

Whereas

array_intersect() returns an array containing all the values of array that are present in all the arguments. Note that keys are preserved.

How to find unused/dead code in java projects

We've started to use Find Bugs to help identify some of the funk in our codebase's target-rich environment for refactorings. I would also consider Structure 101 to identify spots in your codebase's architecture that are too complicated, so you know where the real swamps are.

Mocking static methods with Mockito

As mentioned before you can not mock static methods with mockito.

If changing your testing framework is not an option you can do the following:

Create an interface for DriverManager, mock this interface, inject it via some kind of dependency injection and verify on that mock.

CSS: On hover show and hide different div's at the same time?

http://jsfiddle.net/MBLZx/

Here is the code

_x000D_
_x000D_
 .showme{ _x000D_
   display: none;_x000D_
 }_x000D_
 .showhim:hover .showme{_x000D_
   display : block;_x000D_
 }_x000D_
 .showhim:hover .ok{_x000D_
   display : none;_x000D_
 }
_x000D_
 <div class="showhim">_x000D_
     HOVER ME_x000D_
     <div class="showme">hai</div>_x000D_
     <div class="ok">ok</div>_x000D_
</div>_x000D_
_x000D_
   
_x000D_
_x000D_
_x000D_

Bootstrap 4 - Glyphicons migration?

The glyphicons.less file from Bootstrap 3 is available on GitHub. https://github.com/twbs/bootstrap/blob/master/less/glyphicons.less

It needs these variables:

@icon-font-path:          "../fonts/";
@icon-font-name:          "glyphicons-halflings-regular";
@icon-font-svg-id:        "glyphicons_halflingsregular";

Then you can convert the .less file to a .css file which you can use directly. You can do this online on lesscss.org/less-preview/. Here I've done it for you, save it as glyphicons.css and include it in your HTML files.

<link href="/Content/glyphicons.css" rel="stylesheet" />

You also need the Glyphicon fonts which is in the Bootstrap 3 package, place them in a /fonts/ directory.

Now you can just keep on using Glyphicons with Bootstrap 4 as usual.

How to update Git clone

If you want to fetch + merge, run

git pull

if you want simply to fetch :

git fetch

Difference between multitasking, multithreading and multiprocessing?

MULTIPROCESSING is like the OS handling the different jobs in main memory in such a way that it gives its time to each and every job when other is busy for some task such as I/O operation. So as long as at least one job needs to execute, the cpu never sit idle. and here it is automatically handled by the OS, without user interaction with computer.

But when we say about MULTITASKING, the user is actually involved with different jobs as at one time - minesweeper or checking mail or anything. The cpu executes multiple jobs by switching among them, but the switching is so fast that user has the illusion that both the applications are running simultaneously.

So the main difference between mp and mt is that in mp the OS is handling different jobs in main memory in such a way that if some job is waiting for something then it will jump for the next job to execute. And in mt the user is in interaction with the system and getting the illusion as both or any of the applications are running simultaneously.

Extract substring using regexp in plain bash

    echo "US/Central - 10:26 PM (CST)" | sed -n "s/^.*-\s*\(\S*\).*$/\1/p"

-n      suppress printing
s       substitute
^.*     anything at the beginning
-       up until the dash
\s*     any space characters (any whitespace character)
\(      start capture group
\S*     any non-space characters
\)      end capture group
.*$     anything at the end
\1      substitute 1st capture group for everything on line
p       print it

SSRS 2008 R2 - SSRS 2012 - ReportViewer: Reports are blank in Safari and Chrome

My solution based on the ideas above.

function pageLoad() {
    var element = document.querySelector('table[id*=_fixedTable] > tbody > tr:last-child > td:last-child > div');
    if (element) {
        element.style.overflow = "visible";
    } 
}

It's not limited to a certain id plus you don't need to include any other library such as jQuery.

change background image in body

If you have JQuery loaded already, you can just do this:

$('body').css('background-image', 'url(../images/backgrounds/header-top.jpg)');

EDIT:

First load JQuery in the head tag:

<script src="//ajax.googleapis.com/ajax/libs/jquery/1.7.2/jquery.min.js" type="text/javascript"></script>

Then call the Javascript to change the background image when something happens on the page, like when it finishes loading:

<script type="text/javascript">
    $(document).ready(function() {
        $('body').css('background-image', 'url(../images/backgrounds/header-top.jpg)');
    });
</script>

how to check if List<T> element contains an item with a Particular Property Value

var item = pricePublicList.FirstOrDefault(x => x.Size == 200);
if (item != null) {
   // There exists one with size 200 and is stored in item now
}
else {
  // There is no PricePublicModel with size 200
}

Merge some list items in a Python List

just a variation

alist=["a", "b", "c", "d", "e", 0, "g"]
alist[3:6] = [''.join(map(str,alist[3:6]))]
print alist

How to see the proxy settings on windows?

You can use a tool called: NETSH

To view your system proxy information via command line:

netsh.exe winhttp show proxy

Another way to view it is to open IE, then click on the "gear" icon, then Internet options -> Connections tab -> click on LAN settings

Get sum of MySQL column in PHP

$row['Value'] is probably a string. Try using intval($row['Value']).

Also, make sure you set $sum = 0 before the loop.

Or, better yet, add SUM(Value) AS Val_Sum to your SQL query.

SQL Server: converting UniqueIdentifier to string in a case statement

Instead of Str(RequestID), try convert(varchar(38), RequestID)

Use multiple @font-face rules in CSS

Multiple variations of a font family can be declared by changing the font-weight and src property of @font-face rule.

/* Regular Weight */
@font-face {
    font-family: Montserrat;
    src: url("../fonts/Montserrat-Regular.ttf");
}

/* SemiBold (600) Weight */
@font-face {
    font-family: Montserrat;
    src: url("../fonts/Montserrat-SemiBold.ttf");
    font-weight: 600;
}

/* Bold Weight */
@font-face {
    font-family: Montserrat;
    src: url("../fonts/Montserrat-Bold.ttf");
    font-weight: bold;
}

Declared rules can be used by following

/* Regular */
font-family: Montserrat;


/* Semi Bold */
font-family: Montserrat;
font-weght: 600;

/* Bold */
font-family: Montserrat;
font-weight: bold;

Can we execute a java program without a main() method?

Since you tagged Java-ee as well - then YES it is possible.

and in core java as well it is possible using static blocks

and check this How can you run a Java program without main method?

Edit:
as already pointed out in other answers - it does not support from Java 7

Java - How to convert type collection into ArrayList?

The following code will fail:

List<String> will_fail =  (List<String>)Collections.unmodifiableCollection(new ArrayList<String>());

This instead will work:

List<String> will_work = new ArrayList<String>(Collections.unmodifiableCollection(new ArrayList<String>()));

urllib2.HTTPError: HTTP Error 403: Forbidden

import urllib.request

bank_pdf_list = ["https://www.hdfcbank.com/content/bbp/repositories/723fb80a-2dde-42a3-9793-7ae1be57c87f/?path=/Personal/Home/content/rates.pdf",
"https://www.yesbank.in/pdf/forexcardratesenglish_pdf",
"https://www.sbi.co.in/documents/16012/1400784/FOREX_CARD_RATES.pdf"]


def get_pdf(url):
    user_agent = 'Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9.0.7) Gecko/2009021910 Firefox/3.0.7'
    
    #url = "https://www.yesbank.in/pdf/forexcardratesenglish_pdf"
    headers={'User-Agent':user_agent,} 
    
    request=urllib.request.Request(url,None,headers) #The assembled request
    response = urllib.request.urlopen(request)
    #print(response.text)
    data = response.read()
#    print(type(data))
    
    name = url.split("www.")[-1].split("//")[-1].split(".")[0]+"_FOREX_CARD_RATES.pdf"
    f = open(name, 'wb')
    f.write(data)
    f.close()
    

for bank_url in bank_pdf_list:
    try: 
        get_pdf(bank_url)
    except:
        pass

ListBox vs. ListView - how to choose for data binding

A ListView is a specialized ListBox (that is, it inherits from ListBox). It allows you to specify different views rather than a straight list. You can either roll your own view, or use GridView (think explorer-like "details view"). It's basically the multi-column listbox, the cousin of windows form's listview.

If you don't need the additional capabilities of ListView, you can certainly use ListBox if you're simply showing a list of items (Even if the template is complex).

Merge (Concat) Multiple JSONObjects in Java

It's a while from the question but now JSONObject implements "toMap" method so you can try this way:

Map<String, Object> map = Obj1.toMap();      //making an HashMap from obj1
map.putAll(Obj2.toMap());                    //moving all the stuff from obj2 to map
JSONObject combined = new JSONObject( map ); //new json from map

resource error in android studio after update: No Resource Found

First of all,

Try to check your SDK folder, for me, it was mydocuments/appdata/sdk.... etc. So basically my sdk folder was not fully downloaded, the source of this problem mainly. You have to either use another fully downloaded android sdk(including Tools section and extras that you really need) or use the eclipse sdk that you may downloaded earlier for your Eclipse android developments. Then build->clean your project once again.

Worth to try.

How to start an Android application from the command line?

You can use:

adb shell monkey -p com.package.name -c android.intent.category.LAUNCHER 1

This will start the LAUNCHER Activity of the application using monkeyrunner test tool.

How do I rewrite URLs in a proxy response in NGINX

You may also need the following directive to be set before the first "sub_filter" for backend-servers with data compression:

proxy_set_header Accept-Encoding "";

Otherwise it may not work. For your example it will look like:

location /admin/ {
    proxy_pass http://localhost:8080/;
    proxy_set_header Accept-Encoding "";
    sub_filter "http://your_server/" "http://your_server/admin/";
    sub_filter_once off;
}

Python list / sublist selection -1 weirdness

It seems pretty consistent to me; positive indices are also non-inclusive. I think you're doing it wrong. Remembering that range() is also non-inclusive, and that Python arrays are 0-indexed, here's a sample python session to illustrate:

>>> d = range(10)
>>> d
[0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
>>> d[9]
9
>>> d[-1]
9
>>> d[0:9]
[0, 1, 2, 3, 4, 5, 6, 7, 8]
>>> d[0:-1]
[0, 1, 2, 3, 4, 5, 6, 7, 8]
>>> len(d)
10

How to delete rows from a pandas DataFrame based on a conditional expression

You can assign the DataFrame to a filtered version of itself:

df = df[df.score > 50]

This is faster than drop:

%%timeit
test = pd.DataFrame({'x': np.random.randn(int(1e6))})
test = test[test.x < 0]
# 54.5 ms ± 2.02 ms per loop (mean ± std. dev. of 7 runs, 10 loops each)

%%timeit
test = pd.DataFrame({'x': np.random.randn(int(1e6))})
test.drop(test[test.x > 0].index, inplace=True)
# 201 ms ± 17.9 ms per loop (mean ± std. dev. of 7 runs, 10 loops each)

%%timeit
test = pd.DataFrame({'x': np.random.randn(int(1e6))})
test = test.drop(test[test.x > 0].index)
# 194 ms ± 7.03 ms per loop (mean ± std. dev. of 7 runs, 10 loops each)

Angular 2 Hover event

Simply do (mouseenter) attribute in Angular2+...

In your HTML do:

<div (mouseenter)="mouseHover($event)">Hover!</div> 

and in your component do:

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

@Component({
  selector: 'component',
  templateUrl: './component.html',
  styleUrls: ['./component.scss']
})

export class MyComponent implements OnInit {

  mouseHover(e) {
    console.log('hovered', e);
  }
} 

How do I execute a *.dll file

While many people have pointed out that you can't execute dlls directly and should use rundll32.exe to execute exported functions instead, here is a screenshot of an actual dll file running just like an executable:

enter image description here

While you cannot run dll files directly, I suspect it is possible to run them from another process using a WinAPI function CreateProcess:

https://msdn.microsoft.com/en-us/library/windows/desktop/ms682425(v=vs.85).aspx

How do I set proxy for chrome in python webdriver?

I had an issue with the same thing. ChromeOptions is very weird because it's not integrated with the desiredcapabilities like you would think. I forget the exact details, but basically ChromeOptions will reset to default certain values based on whether you did or did not pass a desired capabilities dict.

I did the following monkey-patch that allows me to specify my own dict without worrying about the complications of ChromeOptions

change the following code in /selenium/webdriver/chrome/webdriver.py:

def __init__(self, executable_path="chromedriver", port=0,
             chrome_options=None, service_args=None,
             desired_capabilities=None, service_log_path=None, skip_capabilities_update=False):
    """
    Creates a new instance of the chrome driver.

    Starts the service and then creates new instance of chrome driver.

    :Args:
     - executable_path - path to the executable. If the default is used it assumes the executable is in the $PATH
     - port - port you would like the service to run, if left as 0, a free port will be found.
     - desired_capabilities: Dictionary object with non-browser specific
       capabilities only, such as "proxy" or "loggingPref".
     - chrome_options: this takes an instance of ChromeOptions
    """
    if chrome_options is None:
        options = Options()
    else:
        options = chrome_options

    if skip_capabilities_update:
        pass
    elif desired_capabilities is not None:
        desired_capabilities.update(options.to_capabilities())
    else:
        desired_capabilities = options.to_capabilities()

    self.service = Service(executable_path, port=port,
        service_args=service_args, log_path=service_log_path)
    self.service.start()

    try:
        RemoteWebDriver.__init__(self,
            command_executor=self.service.service_url,
            desired_capabilities=desired_capabilities)
    except:
        self.quit()
        raise 
    self._is_remote = False

all that changed was the "skip_capabilities_update" kwarg. Now I just do this to set my own dict:

capabilities = dict( DesiredCapabilities.CHROME )

if not "chromeOptions" in capabilities:
    capabilities['chromeOptions'] = {
        'args' : [],
        'binary' : "",
        'extensions' : [],
        'prefs' : {}
    }

capabilities['proxy'] = {
    'httpProxy' : "%s:%i" %(proxy_address, proxy_port),
    'ftpProxy' : "%s:%i" %(proxy_address, proxy_port),
    'sslProxy' : "%s:%i" %(proxy_address, proxy_port),
    'noProxy' : None,
    'proxyType' : "MANUAL",
    'class' : "org.openqa.selenium.Proxy",
    'autodetect' : False
}

driver = webdriver.Chrome( executable_path="path_to_chrome", desired_capabilities=capabilities, skip_capabilities_update=True )

Making authenticated POST requests with Spring RestTemplate for Android

Ok found the answer. exchange() is the best way. Oddly the HttpEntity class doesn't have a setBody() method (it has getBody()), but it is still possible to set the request body, via the constructor.

// Create the request body as a MultiValueMap
MultiValueMap<String, String> body = new LinkedMultiValueMap<String, String>();     

body.add("field", "value");

// Note the body object as first parameter!
HttpEntity<?> httpEntity = new HttpEntity<Object>(body, requestHeaders);

ResponseEntity<MyModel> response = restTemplate.exchange("/api/url", HttpMethod.POST, httpEntity, MyModel.class);

How to detect when cancel is clicked on file input?

The easiest way is to check if there are any files in temporary memory. If you want to get the change event every time user clicks the file input you can trigger it.

var yourFileInput = $("#yourFileInput");

yourFileInput.on('mouseup', function() {
    $(this).trigger("change");
}).on('change', function() {
    if (this.files.length) {
        //User chose a picture
    } else {
        //User clicked cancel
    }
});

DLL Load Library - Error Code 126

This error can happen because some MFC library (eg. mfc120.dll) from which the DLL is dependent is missing in windows/system32 folder.

How might I find the largest number contained in a JavaScript array?

You can use the apply function, to call Math.max:

var array = [267, 306, 108];
var largest = Math.max.apply(Math, array); // 306

How does it work?

The apply function is used to call another function, with a given context and arguments, provided as an array. The min and max functions can take an arbitrary number of input arguments: Math.max(val1, val2, ..., valN)

So if we call:

Math.min.apply(Math, [1, 2, 3, 4]);

The apply function will execute:

Math.min(1, 2, 3, 4);

Note that the first parameter, the context, is not important for these functions since they are static. They will work regardless of what is passed as the context.

How to implement a Navbar Dropdown Hover in Bootstrap v4?

This solution switches on and off

<script>
$(document).ready(function() {
  // close all dropdowns that are open
  $('body').click(function(e) {
      $('.nav-item.show').removeClass('show');
      //$('.nav-item.clicked').removeClass('clicked');
      $('.dropdown-menu.show').removeClass('show');
  });

  $('.nav-item').click( function(e) {
    $(this).addClass('clicked')
  });

  // show dropdown for the link clicked
  $('.nav-item').hover(function(e) {
      if ($('.nav-item.show').length < 1) {
        $('.nav-item.clicked').removeClass('clicked');
      }
      if ($('.nav-item.clicked').length < 1) {
          $('.nav-item.show').removeClass('show');
          $('.dropdown-menu.show').removeClass('show');
          $dd = $(this).find('.dropdown-menu');
          $dd.parent().addClass('show');
          $dd.addClass('show');
      }
  });
});</script>

To disable the hover for lg sized collapse menus add

if(( $(window).width() >= 992 )) {

Parallel.ForEach vs Task.Factory.StartNew

Parallel.ForEach will optimize(may not even start new threads) and block until the loop is finished, and Task.Factory will explicitly create a new task instance for each item, and return before they are finished (asynchronous tasks). Parallel.Foreach is much more efficient.

How to remove CocoaPods from a project?

enter image description here

pictorial representation detailed

Create view with primary key?

You cannot create a primary key on a view. In SQL Server you can create an index on a view but that is different to creating a primary key.

If you give us more information as to why you want a key on your view, perhaps we can help with that.

ConnectivityManager getNetworkInfo(int) deprecated

February 2020 Update:

The accepted answer is deprecated again in 28 (Android P), but its replacement method only works on 23 (Android M). To support older devices, I wrote a helper function in .

How to use:

int type = getConnectionType(getApplicationContext());

It returns an int, you can change it to enum in your code:

0: No Internet available (maybe on airplane mode, or in the process of joining an wi-fi).

1: Cellular (mobile data, 3G/4G/LTE whatever).

2: Wi-fi.

3: VPN

You can copy either the Kotlin or the Java version of the helper function.

Kotlin:

@IntRange(from = 0, to = 3)
fun getConnectionType(context: Context): Int {
    var result = 0 // Returns connection type. 0: none; 1: mobile data; 2: wifi
    val cm = context.getSystemService(Context.CONNECTIVITY_SERVICE) as ConnectivityManager?
    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
        cm?.run {
            cm.getNetworkCapabilities(cm.activeNetwork)?.run {
                if (hasTransport(NetworkCapabilities.TRANSPORT_WIFI)) {
                    result = 2
                } else if (hasTransport(NetworkCapabilities.TRANSPORT_CELLULAR)) {
                    result = 1
                } else if (hasTransport(NetworkCapabilities.TRANSPORT_VPN)){
                    result = 3
                }
            }
        }
    } else {
        cm?.run {
            cm.activeNetworkInfo?.run {
                if (type == ConnectivityManager.TYPE_WIFI) {
                    result = 2
                } else if (type == ConnectivityManager.TYPE_MOBILE) {
                    result = 1
                } else if(type == ConnectivityManager.TYPE_VPN) {
                    result = 3
                }
            }
        }
    }
    return result
}

Java:

@IntRange(from = 0, to = 3)
public static int getConnectionType(Context context) {
    int result = 0; // Returns connection type. 0: none; 1: mobile data; 2: wifi
    ConnectivityManager cm = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
        if (cm != null) {
            NetworkCapabilities capabilities = cm.getNetworkCapabilities(cm.getActiveNetwork());
            if (capabilities != null) {
                if (capabilities.hasTransport(NetworkCapabilities.TRANSPORT_WIFI)) {
                    result = 2;
                } else if (capabilities.hasTransport(NetworkCapabilities.TRANSPORT_CELLULAR)) {
                    result = 1;
                } else if (capabilities.hasTransport(NetworkCapabilities.TRANSPORT_VPN)) {
                    result = 3;
                }
            }
        }
    } else {
        if (cm != null) {
            NetworkInfo activeNetwork = cm.getActiveNetworkInfo();
            if (activeNetwork != null) {
                // connected to the internet
                if (activeNetwork.getType() == ConnectivityManager.TYPE_WIFI) {
                    result = 2;
                } else if (activeNetwork.getType() == ConnectivityManager.TYPE_MOBILE) {
                    result = 1;
                } else if (activeNetwork.getType() == ConnectivityManager.TYPE_VPN) {
                    result = 3;
                }
            }
        }
    }
    return result;
}

Cannot create SSPI context

It sounds like your PC hasn't contacted an authenticating domain controller for a little while. (I used to have this happen on my laptop a few times.)

It can also happen if your password expires.

How can I get the average (mean) of selected columns

Here are some examples:

> z$mean <- rowMeans(subset(z, select = c(x, y)), na.rm = TRUE)
> z
  w x  y mean
1 5 1  1    1
2 6 2  2    2
3 7 3  3    3
4 8 4 NA    4

weighted mean

> z$y <- rev(z$y)
> z
  w x  y mean
1 5 1 NA    1
2 6 2  3    2
3 7 3  2    3
4 8 4  1    4
> 
> weight <- c(1, 2) # x * 1/3 + y * 2/3
> z$wmean <- apply(subset(z, select = c(x, y)), 1, function(d) weighted.mean(d, weight, na.rm = TRUE))
> z
  w x  y mean    wmean
1 5 1 NA    1 1.000000
2 6 2  3    2 2.666667
3 7 3  2    3 2.333333
4 8 4  1    4 2.000000

tell pip to install the dependencies of packages listed in a requirement file

Extending Piotr's answer, if you also need a way to figure what to put in requirements.in, you can first use pip-chill to find the minimal set of required packages you have. By combining these tools, you can show the dependency reason why each package is installed. The full cycle looks like this:

  1. Create virtual environment:
    $ python3 -m venv venv
  2. Activate it:
    $ . venv/bin/activate
  3. Install newest version of pip, pip-tools and pip-chill:
    (venv)$ pip install --upgrade pip
    (venv)$ pip install pip-tools pip-chill
  4. Build your project, install more pip packages, etc, until you want to save...
  5. Extract minimal set of packages (ie, top-level without dependencies):
    (venv)$ pip-chill --no-version > requirements.in
  6. Compile list of all required packages (showing dependency reasons):
    (venv)$ pip-compile requirements.in
  7. Make sure the current installation is synchronized with the list:
    (venv)$ pip-sync

Java: recommended solution for deep cloning/copying an instance

Since version 2.07 Kryo supports shallow/deep cloning:

Kryo kryo = new Kryo();
SomeClass someObject = ...
SomeClass copy1 = kryo.copy(someObject);
SomeClass copy2 = kryo.copyShallow(someObject);

Kryo is fast, at the and of their page you may find a list of companies which use it in production.

How I can get web page's content and save it into the string variable

I recommend not using WebClient.DownloadString. This is because (at least in .NET 3.5) DownloadString is not smart enough to use/remove the BOM, should it be present. This can result in the BOM () incorrectly appearing as part of the string when UTF-8 data is returned (at least without a charset) - ick!

Instead, this slight variation will work correctly with BOMs:

string ReadTextFromUrl(string url) {
    // WebClient is still convenient
    // Assume UTF8, but detect BOM - could also honor response charset I suppose
    using (var client = new WebClient())
    using (var stream = client.OpenRead(url))
    using (var textReader = new StreamReader(stream, Encoding.UTF8, true)) {
        return textReader.ReadToEnd();
    }
}

How can I strip first X characters from string using sed?

Well, there have been solutions here with sed, awk, cut and using bash syntax. I just want to throw in another POSIX conform variant:

$ echo "pid: 1234" | tail -c +6
1234

-c tells tail at which byte offset to start, counting from the end of the input data, yet if the the number starts with a + sign, it is from the beginning of the input data to the end.

Single Page Application: advantages and disadvantages

Disadvantages: Technically, design and initial development of SPA is complex and can be avoided. Other reasons for not using this SPA can be:

  • a) Security: Single Page Application is less secure as compared to traditional pages due to cross site scripting(XSS).
  • b) Memory Leak: Memory leak in JavaScript can even cause powerful Computer to slow down. As traditional websites encourage to navigate among pages, thus any memory leak caused by previous page is almost cleansed leaving less residue behind.
  • c) Client must enable JavaScript to run SPA, but in multi-page application JavaScript can be completely avoided.
  • d) SPA grows to optimal size, cause long waiting time. Eg: Working on Gmail with slower connection.

Apart from above, other architectural limitations are Navigational Data loss, No log of Navigational History in browser and difficulty in Automated Functional Testing with selenium.

This link explain Single Page Application's Advantages and Disadvantages.

Trying to use INNER JOIN and GROUP BY SQL with SUM Function, Not Working

Use subquery

SELECT * FROM RES_DATA inner join (SELECT [CUSTOMER ID], sum([TOTAL AMOUNT]) FROM INV_DATA group by [CUSTOMER ID]) T on RES_DATA.[CUSTOMER ID] = t.[CUSTOMER ID]

Flutter - Wrap text on overflow, like insert ellipsis or fade

One way to fix an overflow of a Text Widget within a row if for example a chat message can be one really long line. You can create a Container and a BoxConstraint with a maxWidth in it.

            Container(
              constraints: BoxConstraints(maxWidth: 200),
                child: Text(
                  (chatName == null) ? " ": chatName,
                  style: TextStyle(
                      fontWeight: FontWeight.w400,
                      color: Colors.black87,
                      fontSize: 17.0),
                )
            ),

IOException: read failed, socket might closed - Bluetooth on Android 4.3

On newer versions of Android, I was receiving this error because the adapter was still discovering when I attempted to connect to the socket. Even though I called the cancelDiscovery method on the Bluetooth adapter, I had to wait until the callback to the BroadcastReceiver's onReceive() method was called with the action BluetoothAdapter.ACTION_DISCOVERY_FINISHED.

Once I waited for the adapter to stop discovery, then the connect call on the socket succeeded.

Comparing arrays in C#

Providing that you have LINQ available and don't care too much about performance, the easiest thing is the following:

var arraysAreEqual = Enumerable.SequenceEqual(a1, a2);

In fact, it's probably worth checking with Reflector or ILSpy what the SequenceEqual methods actually does, since it may well optimise for the special case of array values anyway!

A fatal error has been detected by the Java Runtime Environment: SIGSEGV, libjvm

after hardware check on the server and it was found out that memory had gone bad, replaced the memory and the server is now fully accessible.

Loading and parsing a JSON file with multiple JSON objects

for those stumbling upon this question: the python jsonlines library (much younger than this question) elegantly handles files with one json document per line. see https://jsonlines.readthedocs.io/

What's the difference between .bashrc, .bash_profile, and .environment?

The main difference with shell config files is that some are only read by "login" shells (eg. when you login from another host, or login at the text console of a local unix machine). these are the ones called, say, .login or .profile or .zlogin (depending on which shell you're using).

Then you have config files that are read by "interactive" shells (as in, ones connected to a terminal (or pseudo-terminal in the case of, say, a terminal emulator running under a windowing system). these are the ones with names like .bashrc, .tcshrc, .zshrc, etc.

bash complicates this in that .bashrc is only read by a shell that's both interactive and non-login, so you'll find most people end up telling their .bash_profile to also read .bashrc with something like

[[ -r ~/.bashrc ]] && . ~/.bashrc

Other shells behave differently - eg with zsh, .zshrc is always read for an interactive shell, whether it's a login one or not.

The manual page for bash explains the circumstances under which each file is read. Yes, behaviour is generally consistent between machines.

.profile is simply the login script filename originally used by /bin/sh. bash, being generally backwards-compatible with /bin/sh, will read .profile if one exists.

How to put labels over geom_bar for each bar in R with ggplot2

To add to rcs' answer, if you want to use position_dodge() with geom_bar() when x is a POSIX.ct date, you must multiply the width by 86400, e.g.,

ggplot(data=dat, aes(x=Types, y=Number, fill=sample)) + 
 geom_bar(position = "dodge", stat = 'identity') +
 geom_text(aes(label=Number), position=position_dodge(width=0.9*86400), vjust=-0.25)

How to define two fields "unique" as couple

Django 2.2+

Using the constraints features UniqueConstraint is preferred over unique_together.

From the Django documentation for unique_together:

Use UniqueConstraint with the constraints option instead.
UniqueConstraint provides more functionality than unique_together.
unique_together may be deprecated in the future.

For example:

class Volume(models.Model):
    id = models.AutoField(primary_key=True)
    journal_id = models.ForeignKey(Journals, db_column='jid', null=True, verbose_name="Journal")
    volume_number = models.CharField('Volume Number', max_length=100)
    comments = models.TextField('Comments', max_length=4000, blank=True)

    class Meta:
        constraints = [
            models.UniqueConstraint(fields=['journal_id', 'volume_number'], name='name of constraint')
        ]

Perl: function to trim string leading and trailing whitespace

Here's one approach using a regular expression:

$string =~ s/^\s+|\s+$//g ;     # remove both leading and trailing whitespace

Perl 6 will include a trim function:

$string .= trim;

Source: Wikipedia

What's the difference between eval, exec, and compile?

The short answer, or TL;DR

Basically, eval is used to evaluate a single dynamically generated Python expression, and exec is used to execute dynamically generated Python code only for its side effects.

eval and exec have these two differences:

  1. eval accepts only a single expression, exec can take a code block that has Python statements: loops, try: except:, class and function/method definitions and so on.

    An expression in Python is whatever you can have as the value in a variable assignment:

    a_variable = (anything you can put within these parentheses is an expression)
    
  2. eval returns the value of the given expression, whereas exec ignores the return value from its code, and always returns None (in Python 2 it is a statement and cannot be used as an expression, so it really does not return anything).

In versions 1.0 - 2.7, exec was a statement, because CPython needed to produce a different kind of code object for functions that used exec for its side effects inside the function.

In Python 3, exec is a function; its use has no effect on the compiled bytecode of the function where it is used.


Thus basically:

>>> a = 5
>>> eval('37 + a')   # it is an expression
42
>>> exec('37 + a')   # it is an expression statement; value is ignored (None is returned)
>>> exec('a = 47')   # modify a global variable as a side effect
>>> a
47
>>> eval('a = 47')  # you cannot evaluate a statement
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "<string>", line 1
    a = 47
      ^
SyntaxError: invalid syntax

The compile in 'exec' mode compiles any number of statements into a bytecode that implicitly always returns None, whereas in 'eval' mode it compiles a single expression into bytecode that returns the value of that expression.

>>> eval(compile('42', '<string>', 'exec'))  # code returns None
>>> eval(compile('42', '<string>', 'eval'))  # code returns 42
42
>>> exec(compile('42', '<string>', 'eval'))  # code returns 42,
>>>                                          # but ignored by exec

In the 'eval' mode (and thus with the eval function if a string is passed in), the compile raises an exception if the source code contains statements or anything else beyond a single expression:

>>> compile('for i in range(3): print(i)', '<string>', 'eval')
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "<string>", line 1
    for i in range(3): print(i)
      ^
SyntaxError: invalid syntax

Actually the statement "eval accepts only a single expression" applies only when a string (which contains Python source code) is passed to eval. Then it is internally compiled to bytecode using compile(source, '<string>', 'eval') This is where the difference really comes from.

If a code object (which contains Python bytecode) is passed to exec or eval, they behave identically, excepting for the fact that exec ignores the return value, still returning None always. So it is possible use eval to execute something that has statements, if you just compiled it into bytecode before instead of passing it as a string:

>>> eval(compile('if 1: print("Hello")', '<string>', 'exec'))
Hello
>>>

works without problems, even though the compiled code contains statements. It still returns None, because that is the return value of the code object returned from compile.

In the 'eval' mode (and thus with the eval function if a string is passed in), the compile raises an exception if the source code contains statements or anything else beyond a single expression:

>>> compile('for i in range(3): print(i)', '<string>'. 'eval')
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "<string>", line 1
    for i in range(3): print(i)
      ^
SyntaxError: invalid syntax

The longer answer, a.k.a the gory details

exec and eval

The exec function (which was a statement in Python 2) is used for executing a dynamically created statement or program:

>>> program = '''
for i in range(3):
    print("Python is cool")
'''
>>> exec(program)
Python is cool
Python is cool
Python is cool
>>> 

The eval function does the same for a single expression, and returns the value of the expression:

>>> a = 2
>>> my_calculation = '42 * a'
>>> result = eval(my_calculation)
>>> result
84

exec and eval both accept the program/expression to be run either as a str, unicode or bytes object containing source code, or as a code object which contains Python bytecode.

If a str/unicode/bytes containing source code was passed to exec, it behaves equivalently to:

exec(compile(source, '<string>', 'exec'))

and eval similarly behaves equivalent to:

eval(compile(source, '<string>', 'eval'))

Since all expressions can be used as statements in Python (these are called the Expr nodes in the Python abstract grammar; the opposite is not true), you can always use exec if you do not need the return value. That is to say, you can use either eval('my_func(42)') or exec('my_func(42)'), the difference being that eval returns the value returned by my_func, and exec discards it:

>>> def my_func(arg):
...     print("Called with %d" % arg)
...     return arg * 2
... 
>>> exec('my_func(42)')
Called with 42
>>> eval('my_func(42)')
Called with 42
84
>>> 

Of the 2, only exec accepts source code that contains statements, like def, for, while, import, or class, the assignment statement (a.k.a a = 42), or entire programs:

>>> exec('for i in range(3): print(i)')
0
1
2
>>> eval('for i in range(3): print(i)')
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "<string>", line 1
    for i in range(3): print(i)
      ^
SyntaxError: invalid syntax

Both exec and eval accept 2 additional positional arguments - globals and locals - which are the global and local variable scopes that the code sees. These default to the globals() and locals() within the scope that called exec or eval, but any dictionary can be used for globals and any mapping for locals (including dict of course). These can be used not only to restrict/modify the variables that the code sees, but are often also used for capturing the variables that the executed code creates:

>>> g = dict()
>>> l = dict()
>>> exec('global a; a, b = 123, 42', g, l)
>>> g['a']
123
>>> l
{'b': 42}

(If you display the value of the entire g, it would be much longer, because exec and eval add the built-ins module as __builtins__ to the globals automatically if it is missing).

In Python 2, the official syntax for the exec statement is actually exec code in globals, locals, as in

>>> exec 'global a; a, b = 123, 42' in g, l

However the alternate syntax exec(code, globals, locals) has always been accepted too (see below).

compile

The compile(source, filename, mode, flags=0, dont_inherit=False, optimize=-1) built-in can be used to speed up repeated invocations of the same code with exec or eval by compiling the source into a code object beforehand. The mode parameter controls the kind of code fragment the compile function accepts and the kind of bytecode it produces. The choices are 'eval', 'exec' and 'single':

  • 'eval' mode expects a single expression, and will produce bytecode that when run will return the value of that expression:

    >>> dis.dis(compile('a + b', '<string>', 'eval'))
      1           0 LOAD_NAME                0 (a)
                  3 LOAD_NAME                1 (b)
                  6 BINARY_ADD
                  7 RETURN_VALUE
    
  • 'exec' accepts any kinds of python constructs from single expressions to whole modules of code, and executes them as if they were module top-level statements. The code object returns None:

    >>> dis.dis(compile('a + b', '<string>', 'exec'))
      1           0 LOAD_NAME                0 (a)
                  3 LOAD_NAME                1 (b)
                  6 BINARY_ADD
                  7 POP_TOP                             <- discard result
                  8 LOAD_CONST               0 (None)   <- load None on stack
                 11 RETURN_VALUE                        <- return top of stack
    
  • 'single' is a limited form of 'exec' which accepts a source code containing a single statement (or multiple statements separated by ;) if the last statement is an expression statement, the resulting bytecode also prints the repr of the value of that expression to the standard output(!).

    An if-elif-else chain, a loop with else, and try with its except, else and finally blocks is considered a single statement.

    A source fragment containing 2 top-level statements is an error for the 'single', except in Python 2 there is a bug that sometimes allows multiple toplevel statements in the code; only the first is compiled; the rest are ignored:

    In Python 2.7.8:

    >>> exec(compile('a = 5\na = 6', '<string>', 'single'))
    >>> a
    5
    

    And in Python 3.4.2:

    >>> exec(compile('a = 5\na = 6', '<string>', 'single'))
    Traceback (most recent call last):
      File "<stdin>", line 1, in <module>
      File "<string>", line 1
        a = 5
            ^
    SyntaxError: multiple statements found while compiling a single statement
    

    This is very useful for making interactive Python shells. However, the value of the expression is not returned, even if you eval the resulting code.

Thus greatest distinction of exec and eval actually comes from the compile function and its modes.


In addition to compiling source code to bytecode, compile supports compiling abstract syntax trees (parse trees of Python code) into code objects; and source code into abstract syntax trees (the ast.parse is written in Python and just calls compile(source, filename, mode, PyCF_ONLY_AST)); these are used for example for modifying source code on the fly, and also for dynamic code creation, as it is often easier to handle the code as a tree of nodes instead of lines of text in complex cases.


While eval only allows you to evaluate a string that contains a single expression, you can eval a whole statement, or even a whole module that has been compiled into bytecode; that is, with Python 2, print is a statement, and cannot be evalled directly:

>>> eval('for i in range(3): print("Python is cool")')
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "<string>", line 1
    for i in range(3): print("Python is cool")
      ^
SyntaxError: invalid syntax

compile it with 'exec' mode into a code object and you can eval it; the eval function will return None.

>>> code = compile('for i in range(3): print("Python is cool")',
                   'foo.py', 'exec')
>>> eval(code)
Python is cool
Python is cool
Python is cool

If one looks into eval and exec source code in CPython 3, this is very evident; they both call PyEval_EvalCode with same arguments, the only difference being that exec explicitly returns None.

Syntax differences of exec between Python 2 and Python 3

One of the major differences in Python 2 is that exec is a statement and eval is a built-in function (both are built-in functions in Python 3). It is a well-known fact that the official syntax of exec in Python 2 is exec code [in globals[, locals]].

Unlike majority of the Python 2-to-3 porting guides seem to suggest, the exec statement in CPython 2 can be also used with syntax that looks exactly like the exec function invocation in Python 3. The reason is that Python 0.9.9 had the exec(code, globals, locals) built-in function! And that built-in function was replaced with exec statement somewhere before Python 1.0 release.

Since it was desirable to not break backwards compatibility with Python 0.9.9, Guido van Rossum added a compatibility hack in 1993: if the code was a tuple of length 2 or 3, and globals and locals were not passed into the exec statement otherwise, the code would be interpreted as if the 2nd and 3rd element of the tuple were the globals and locals respectively. The compatibility hack was not mentioned even in Python 1.4 documentation (the earliest available version online); and thus was not known to many writers of the porting guides and tools, until it was documented again in November 2012:

The first expression may also be a tuple of length 2 or 3. In this case, the optional parts must be omitted. The form exec(expr, globals) is equivalent to exec expr in globals, while the form exec(expr, globals, locals) is equivalent to exec expr in globals, locals. The tuple form of exec provides compatibility with Python 3, where exec is a function rather than a statement.

Yes, in CPython 2.7 that it is handily referred to as being a forward-compatibility option (why confuse people over that there is a backward compatibility option at all), when it actually had been there for backward-compatibility for two decades.

Thus while exec is a statement in Python 1 and Python 2, and a built-in function in Python 3 and Python 0.9.9,

>>> exec("print(a)", globals(), {'a': 42})
42

has had identical behaviour in possibly every widely released Python version ever; and works in Jython 2.5.2, PyPy 2.3.1 (Python 2.7.6) and IronPython 2.6.1 too (kudos to them following the undocumented behaviour of CPython closely).

What you cannot do in Pythons 1.0 - 2.7 with its compatibility hack, is to store the return value of exec into a variable:

Python 2.7.11+ (default, Apr 17 2016, 14:00:29) 
[GCC 5.3.1 20160413] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> a = exec('print(42)')
  File "<stdin>", line 1
    a = exec('print(42)')
           ^
SyntaxError: invalid syntax

(which wouldn't be useful in Python 3 either, as exec always returns None), or pass a reference to exec:

>>> call_later(exec, 'print(42)', delay=1000)
  File "<stdin>", line 1
    call_later(exec, 'print(42)', delay=1000)
                  ^
SyntaxError: invalid syntax

Which a pattern that someone might actually have used, though unlikely;

Or use it in a list comprehension:

>>> [exec(i) for i in ['print(42)', 'print(foo)']
  File "<stdin>", line 1
    [exec(i) for i in ['print(42)', 'print(foo)']
        ^
SyntaxError: invalid syntax

which is abuse of list comprehensions (use a for loop instead!).

set environment variable in python script

Compact solution (provided you don't need other environment variables):

call('sqsub -np {} /homedir/anotherdir/executable'.format(var1).split(),
      env=dict(LD_LIBRARY_PATH=my_path))

Using the env command line tool:

call('env LD_LIBRARY_PATH=my_path sqsub -np {} /homedir/anotherdir/executable'.format(var1).split())

How do I read a string entered by the user in C?

I think the best and safest way to read strings entered by the user is using getline()

Here's an example how to do this:

#include <stdio.h>
#include <stdlib.h>
int main(int argc, char *argv[])
{
    char *buffer = NULL;
    int read;
    unsigned int len;
    read = getline(&buffer, &len, stdin);
    if (-1 != read)
        puts(buffer);
    else
        printf("No line read...\n");

    printf("Size read: %d\n Len: %d\n", read, len);
    free(buffer);
    return 0;
}

Using %s in C correctly - very basic level

Here goes:

char str[] = "This is the end";
char input[100];

printf("%s\n", str);
printf("%c\n", *str);

scanf("%99s", input);

How to load Spring Application Context

package com.dataload;

    public class insertCSV 
    {
        public static void main(String args[])
        {
            ApplicationContext context =
        new ClassPathXmlApplicationContext("applicationcontext.xml");


            // retrieve configured instance
            JobLauncher launcher = context.getBean("laucher", JobLauncher.class);
            Job job = context.getBean("job", Job.class);
            JobParameters jobParameters = context.getBean("jobParameters", JobParameters.class);
        }
    }

Declare and assign multiple string variables at the same time

You can to do it this way:

string Camnr = "", Klantnr = "", ... // or String.Empty

Or you could declare them all first and then in the next line use your way.

XPath contains(text(),'some string') doesn't work when used with node with more than one Text subnode

[contains(text(),'')] only returns true or false. It won't return any element results.

Adding a new array element to a JSON object

For example here is a element like button for adding item to basket and appropriate attributes for saving in localStorage.

'<a href="#" cartBtn pr_id='+e.id+' pr_name_en="'+e.nameEn+'" pr_price="'+e.price+'" pr_image="'+e.image+'" class="btn btn-primary"><i class="fa fa-shopping-cart"></i>Add to cart</a>'

var productArray=[];


$(document).on('click','[cartBtn]',function(e){
  e.preventDefault();
  $(this).html('<i class="fa fa-check"></i>Added to cart');
  console.log('Item added ');
  var productJSON={"id":$(this).attr('pr_id'), "nameEn":$(this).attr('pr_name_en'), "price":$(this).attr('pr_price'), "image":$(this).attr('pr_image')};


  if(localStorage.getObj('product')!==null){
    productArray=localStorage.getObj('product');
    productArray.push(productJSON);  
    localStorage.setObj('product', productArray);  
  }
  else{
    productArray.push(productJSON);  
    localStorage.setObj('product', productArray);  
  }


});

Storage.prototype.setObj = function(key, value) {
    this.setItem(key, JSON.stringify(value));
}

Storage.prototype.getObj = function(key) {
    var value = this.getItem(key);
    return value && JSON.parse(value);
}

After adding JSON object to Array result is (in LocalStorage):

[{"id":"99","nameEn":"Product Name1","price":"767","image":"1462012597217.jpeg"},{"id":"93","nameEn":"Product Name2","price":"76","image":"1461449637106.jpeg"},{"id":"94","nameEn":"Product Name3","price":"87","image":"1461449679506.jpeg"}]

after this action you can easily send data to server as List in Java

Full code example is here

How do I store a simple cart using localStorage?

How can I find my Apple Developer Team id and Team Agent Apple ID?

For personal teams

grep DEVELOPMENT_TEAM MyProject.xcodeproj/project.pbxproj

should give you the team ID

DEVELOPMENT_TEAM = ZU88ND8437;

Javascript "Cannot read property 'length' of undefined" when checking a variable's length

Why?

You asked why it happens, let's see:

The official language specificaion dictates a call to the internal [[GetValue]] method. Your .attr returns undefined and you're trying to access its length.

If Type(V) is not Reference, return V.

This is true, since undefined is not a reference (alongside null, number, string and boolean)

Let base be the result of calling GetBase(V).

This gets the undefined part of myVar.length .

If IsUnresolvableReference(V), throw a ReferenceError exception.

This is not true, since it is resolvable and it resolves to undefined.

If IsPropertyReference(V), then

This happens since it's a property reference with the . syntax.

Now it tries to convert undefined to a function which results in a TypeError.

how to assign a block of html code to a javascript variable

Please use symbol backtick '`' in your front and end of html string, this is so called template literals, now you able to write pure html in multiple lines and assign to variable.

Example >>

var htmlString =

`

<span>Your</span>
<p>HTML</p>

`

How to create a new branch from a tag?

If you simply want to create a new branch without immediately changing to it, you could do the following:

git branch newbranch v1.0

Does it make sense to use Require.js with Angular.js?

It makes sense to use requirejs with angularjs if you plan on lazy loading controllers and directives etc, while also combining multiple lazy dependencies into single script files for much faster lazy loading. RequireJS has an optimisation tool that makes the combining easy. See http://ify.io/using-requirejs-with-optimisation-for-lazy-loading-angularjs-artefacts/

Quick Sort Vs Merge Sort

It is not true that quicksort is better. ALso, it depends on what you mean better, memory consumption, or speed.

In terms of memory consumption, in worst case, but quicksort can use n^2 memory (i.e. each partition is 1 to n-1), whereas merge sort uses nlogn.

The above follows in terms of speed.

Select SQL Server database size

This query generates size for both log and data in MB as well as GB

SELECT X.database_name,
       X.log_size_mb,
       X.log_size_mb / 1024 AS log_size_gb,
       X.row_size_mb,
       X.row_size_mb / 1024 AS row_size_gb,
       X.total_size_mb,
       X.total_size_mb / 1024 AS total_size_gb
  FROM (SELECT database_name = DB_NAME(database_id),
                  log_size_mb = CAST(SUM(CASE
                                              WHEN type_desc = 'LOG' THEN size END) * 8. / 1024 AS DECIMAL(8, 2)),
                  row_size_mb = CAST(SUM(CASE
                                              WHEN type_desc = 'ROWS' THEN size END) * 8. / 1024 AS DECIMAL(8, 2)),
                  total_size_mb = CAST(SUM(size) * 8. / 1024 AS DECIMAL(8, 2))
            FROM sys.master_files WITH (NOWAIT)
            WHERE database_id = DB_ID() -- current db by default
            GROUP BY database_id) AS X

JavaScript - populate drop down list with array

["1","2","3","4"].forEach( function(item) { 
   const optionObj = document.createElement("option");
   optionObj.textContent = item;
   document.getElementById("myselect").appendChild(optionObj);
});

Combine two or more columns in a dataframe into a new column with a new name

Instead of

  • paste (default spaces),
  • paste0 (force the inclusion of missing NA as character) or
  • unite (constrained to 2 columns and 1 separator),

I'd suggest an alternative as flexible as paste0 but more careful with NA: stringr::str_c

library(tidyverse)

# check the missing value!!
df <- tibble(
  n = c(2, 2, 8),
  s = c("aa", "aa", NA_character_),
  b = c(TRUE, FALSE, TRUE)
)

df %>% 
  mutate(
    paste = paste(n,"-",s,".",b),
    paste0 = paste0(n,"-",s,".",b),
    str_c = str_c(n,"-",s,".",b)
  ) %>% 

  # convert missing value to ""
  mutate(
    s_2=str_replace_na(s,replacement = "")
  ) %>% 
  mutate(
    str_c_2 = str_c(n,"-",s_2,".",b)
  )
#> # A tibble: 3 x 8
#>       n s     b     paste          paste0     str_c      s_2   str_c_2   
#>   <dbl> <chr> <lgl> <chr>          <chr>      <chr>      <chr> <chr>     
#> 1     2 aa    TRUE  2 - aa . TRUE  2-aa.TRUE  2-aa.TRUE  "aa"  2-aa.TRUE 
#> 2     2 aa    FALSE 2 - aa . FALSE 2-aa.FALSE 2-aa.FALSE "aa"  2-aa.FALSE
#> 3     8 <NA>  TRUE  8 - NA . TRUE  8-NA.TRUE  <NA>       ""    8-.TRUE

Created on 2020-04-10 by the reprex package (v0.3.0)

extra note from str_c documentation

Like most other R functions, missing values are "infectious": whenever a missing value is combined with another string the result will always be missing. Use str_replace_na() to convert NA to "NA"

Using the AND and NOT Operator in Python

It's called and and or in Python.

How to open a txt file and read numbers in Java

File file = new File("file.txt");   
Scanner scanner = new Scanner(file);
List<Integer> integers = new ArrayList<>();
while (scanner.hasNext()) {
    if (scanner.hasNextInt()) {
        integers.add(scanner.nextInt());
    } 
    else {
        scanner.next();
    }
}
System.out.println(integers);

TypeError: 'str' object cannot be interpreted as an integer

You have to convert input x and y into int like below.

x=int(x)
y=int(y)

MYSQL Sum Query with IF Condition

Try with a CASE in this way :

SUM(CASE 
    WHEN PaymentType = "credit card" 
    THEN TotalAmount 
    ELSE 0 
END) AS CreditCardTotal,

Should give what you are looking for ...

How can I determine if a date is between two dates in Java?

Here's how to find whether today is between 2 months:

private boolean isTodayBetween(int from, int to) {
    if (from < 0 || to < 0 || from > Calendar.DECEMBER || to > Calendar.DECEMBER) {
        throw new IllegalArgumentException("Invalid month provided: from = " + from + " to = " + to);
    }
    Date now = new Date();
    GregorianCalendar cal = new GregorianCalendar();
    cal.setTime(now);
    int thisMonth = cal.get(Calendar.MONTH);
    if (from > to) {
        to = to + Calendar.DECEMBER;
        thisMonth = thisMonth + Calendar.DECEMBER;
    }
    if (thisMonth >= from && thisMonth <= to) {
        return true;
    }
    return false;
}

and call it like:

isTodayBetween(Calendar.OCTOBER, Calendar.MARCH)

What do parentheses surrounding an object/function/class declaration mean?

The first parentheses are for, if you will, order of operations. The 'result' of the set of parentheses surrounding the function definition is the function itself which, indeed, the second set of parentheses executes.

As to why it's useful, I'm not enough of a JavaScript wizard to have any idea. :P

No restricted globals

Try adding window before location (i.e. window.location).

How can I take a screenshot/image of a website using Python?

Using Rendertron is an option. Under the hood, this is a headless Chrome exposing the following endpoints:

  • /render/:url: Access this route e.g. with requests.get if you are interested in the DOM.
  • /screenshot/:url: Access this route if you are interested in a screenshot.

You would install rendertron with npm, run rendertron in one terminal, access http://localhost:3000/screenshot/:url and save the file, but a demo is available at render-tron.appspot.com making it possible to run this Python3 snippet locally without installing the npm package:

import requests

BASE = 'https://render-tron.appspot.com/screenshot/'
url = 'https://google.com'
path = 'target.jpg'
response = requests.get(BASE + url, stream=True)
# save file, see https://stackoverflow.com/a/13137873/7665691
if response.status_code == 200:
    with open(path, 'wb') as file:
        for chunk in response:
            file.write(chunk)

Split function in oracle to comma separated values with automatic sequence

Best Query For comma separated in This Query we Convert Rows To Column ...

SELECT listagg(BL_PRODUCT_DESC, ', ') within
   group(   order by BL_PRODUCT_DESC) PROD
  FROM GET_PRODUCT
--  WHERE BL_PRODUCT_DESC LIKE ('%WASH%')
  WHERE Get_Product_Type_Id = 6000000000007

Delete with Join in MySQL

Try like below:

DELETE posts.*,projects.* 
FROM posts
INNER JOIN projects ON projects.project_id = posts.project_id
WHERE projects.client_id = :client_id;

UICollectionView current visible cell index

For completeness sake, this is the method that ended up working for me. It was a combination of @Anthony & @iAn's methods.

- (void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView {
      CGRect visibleRect = (CGRect){.origin = self.collectionView.contentOffset, .size = self.collectionView.bounds.size};
      CGPoint visiblePoint = CGPointMake(CGRectGetMidX(visibleRect), CGRectGetMidY(visibleRect));
      NSIndexPath *visibleIndexPath = [self.collectionView indexPathForItemAtPoint:visiblePoint];
      NSLog(@"%@",visibleIndexPath);
}

PHP Fatal error: Cannot redeclare class

Did You use Zend Framework? I have the same problem too.
I solved it by commenting out this the following line in config/application.ini:

;includePaths.library = APPLICATION_PATH "/../library"

I hope this will help you.

What is the App_Data folder used for in Visual Studio?

in IIS, highlight the machine, double-click "Request Filtering", open the "Hidden Segments" tab. "App_Data" is listed there as a restricted folder. Yes i know this thread is really old, but this is still applicable.

Determine whether a key is present in a dictionary

In the same vein as martineau's response, the best solution is often not to check. For example, the code

if x in d:
    foo = d[x]
else:
    foo = bar

is normally written

foo = d.get(x, bar)

which is shorter and more directly speaks to what you mean.

Another common case is something like

if x not in d:
    d[x] = []

d[x].append(foo)

which can be rewritten

d.setdefault(x, []).append(foo)

or rewritten even better by using a collections.defaultdict(list) for d and writing

d[x].append(foo)

When should I use cross apply over inner join?

Cross apply works well with an XML field as well. If you wish to select node values in combination with other fields.

For example, if you have a table containing some xml

<root>
    <subnode1>
       <some_node value="1" />
       <some_node value="2" />
       <some_node value="3" />
       <some_node value="4" />
    </subnode1>
</root>

Using the query

SELECT
       id as [xt_id]
      ,xmlfield.value('(/root/@attribute)[1]', 'varchar(50)') root_attribute_value
  ,node_attribute_value = [some_node].value('@value', 'int')
  ,lt.lt_name   
FROM dbo.table_with_xml xt
CROSS APPLY xmlfield.nodes('/root/subnode1/some_node') as g ([some_node])
LEFT OUTER JOIN dbo.lookup_table lt
ON [some_node].value('@value', 'int') = lt.lt_id

Will return a result

xt_id root_attribute_value node_attribute_value lt_name
----------------------------------------------------------------------
1     test1            1                    Benefits
1     test1            4                    FINRPTCOMPANY

JAVA_HOME does not point to the JDK

It looks like you are currently pointing JAVA_HOME to /usr/lib/jvm/java-6-openjdk/jre which appears to be a JRE not a JDK. Try setting JAVA_HOME to /usr/lib/jvm/java-6-openjdk.

The JRE does not contain the Java compiler, only the JDK (Java Developer Kit) contains it.

How do I create a MessageBox in C#?

Also you can use a MessageBox with OKCancel options, but it requires many codes. The if block is for OK, the else block is for Cancel. Here is the code:

if (MessageBox.Show("Are you sure you want to do this?", "Question", MessageBoxButtons.OKCancel, MessageBoxIcon.Question) == DialogResult.OK)
{
    MessageBox.Show("You pressed OK!");
}
else
{
    MessageBox.Show("You pressed Cancel!");
}

You can also use a MessageBox with YesNo options:

if (MessageBox.Show("Are you sure want to doing this?", "Question", MessageBoxButtons.YesNo, MessageBoxIcon.Question) == DialogResult.Yes)
{
    MessageBox.Show("You are pressed Yes!");
}
else
{
    MessageBox.Show("You are pressed No!");
}

cmake error 'the source does not appear to contain CMakeLists.txt'

Since you add .. after cmake, it will jump up and up (just like cd ..) in the directory. But if you want to run cmake under the same folder with CMakeLists.txt, please use . instead of ...

How to choose between Hudson and Jenkins?

Just my take on the matter, three months later:

Jenkins has continued the path well-trodden by the original Hudson with frequent releases including many minor updates.

Oracle seems to have largely delegated work on the future path for Hudson to the Sonatype team, who has performed some significant changes, especially with respect to Maven. They have jointly moved it to the Eclipse foundation.

I would suggest that if you like the sound of:

  • less frequent releases but ones that are more heavily tested for backwards compatibility (more of an "enterprise-style" release cycle)
  • a product focused primarily on strong Maven and/or Nexus integration (i.e., you have no interest in Gradle and Artifactory etc)
  • professional support offerings from Sonatype or maybe Oracle in preference to Cloudbees etc
  • you don't mind having a smaller community of plugin developers etc.

, then I would suggest Hudson.

Conversely, if you prefer:

  • more frequent updates, even if they require a bit more frequent tweaking and are perhaps slightly riskier in terms of compatibility (more of a "latest and greatest" release cycle)
  • a system with more active community support for e.g., other build systems / artifact repositories
  • support offerings from the original creator et al. and/or you have no interest in professional support (e.g., you're happy as long as you can get a fix in next week's "latest and greatest")
  • a classical OSS-style witches' brew of a development ecosystem

then I would suggest Jenkins. (and as a commenter noted, Jenkins now also has "LTS" releases which are maintained on a more "stable" branch)


The conservative course would be to choose Hudson now and migrate to Jenkins if must-have features are unavailable. The dynamic course would be to choose Jenkins now and migrate to Hudson if chasing updates becomes too time-consuming to justify.

SQL Server: combining multiple rows into one row

Using MySQL inbuilt function group_concat() will be a good choice for getting the desired result. The syntax will be -

SELECT group_concat(STRINGVALUE) 
FROM Jira.customfieldvalue
WHERE CUSTOMFIELD = 12534
AND ISSUE = 19602

Before you execute the above command make sure you increase the size of group_concat_max_len else the the whole output may not fit in that cell.

To set the value of group_concat_max_len, execute the below command-

SET group_concat_max_len = 50000;

You can change the value 50000 accordingly, you increase it to a higher value as required.

How to read the output from git diff?

@@ -1,2 +3,4 @@ part of the diff

This part took me a while to understand, so I've created a minimal example.

The format is basically the same the diff -u unified diff.

For instance:

diff -u <(seq 16) <(seq 16 | grep -Ev '^(2|3|14|15)$')

Here we removed lines 2, 3, 14 and 15. Output:

@@ -1,6 +1,4 @@
 1
-2
-3
 4
 5
 6
@@ -11,6 +9,4 @@
 11
 12
 13
-14
-15
 16

@@ -1,6 +1,4 @@ means:

  • -1,6 means that this piece of the first file starts at line 1 and shows a total of 6 lines. Therefore it shows lines 1 to 6.

    1
    2
    3
    4
    5
    6
    

    - means "old", as we usually invoke it as diff -u old new.

  • +1,4 means that this piece of the second file starts at line 1 and shows a total of 4 lines. Therefore it shows lines 1 to 4.

    + means "new".

    We only have 4 lines instead of 6 because 2 lines were removed! The new hunk is just:

    1
    4
    5
    6
    

@@ -11,6 +9,4 @@ for the second hunk is analogous:

  • on the old file, we have 6 lines, starting at line 11 of the old file:

    11
    12
    13
    14
    15
    16
    
  • on the new file, we have 4 lines, starting at line 9 of the new file:

    11
    12
    13
    16
    

    Note that line 11 is the 9th line of the new file because we have already removed 2 lines on the previous hunk: 2 and 3.

Hunk header

Depending on your git version and configuration, you can also get a code line next to the @@ line, e.g. the func1() { in:

@@ -4,7 +4,6 @@ func1() {

This can also be obtained with the -p flag of plain diff.

Example: old file:

func1() {
    1;
    2;
    3;
    4;
    5;
    6;
    7;
    8;
    9;
}

If we remove line 6, the diff shows:

@@ -4,7 +4,6 @@ func1() {
     3;
     4;
     5;
-    6;
     7;
     8;
     9;

Note that this is not the correct line for func1: it skipped lines 1 and 2.

This awesome feature often tells exactly to which function or class each hunk belongs, which is very useful to interpret the diff.

How the algorithm to choose the header works exactly is discussed at: Where does the excerpt in the git diff hunk header come from?

jQuery select box validation

Since you cannot set value="" within your first option, you'll need to create your own rule using the built-in addMethod() method.

jQuery:

$(document).ready(function () {

    $('#myform').validate({ // initialize the plugin
        rules: {
            year: {
                selectcheck: true
            }
        }
    });

    jQuery.validator.addMethod('selectcheck', function (value) {
        return (value != '0');
    }, "year required");

});

HTML:

<select name="year">
    <option value="0">Year</option>
    <option value="1">1955</option>
    <option value="2">1956</option>
</select>

Working Demo: http://jsfiddle.net/tPRNd/


Original Answer: (Only if you can set value="" within the first option)

To properly validate a select element with the jQuery Validate plugin simply requires that the first option contains value="". So remove the 0 from value="0" and it's fixed.

jQuery:

$(document).ready(function () {

    $('#myform').validate({ // initialize the plugin
        rules: {
            year: {
                required: true,
            }
        }
    });

});

HTML:

<select name="year">
    <option value="">Year</option>
    <option value="1">1955</option>
    <option value="2">1956</option>
</select>

Demo: http://jsfiddle.net/XGtEr/

How to retrieve unique count of a field using Kibana + Elastic Search

Be aware with Unique count you are using 'cardinality' metric, which does not always guarantee exact unique count. :-)

the cardinality metric is an approximate algorithm. It is based on the HyperLogLog++ (HLL) algorithm. HLL works by hashing your input and using the bits from the hash to make probabilistic estimations on the cardinality.

Depending on amount of data I can get differences of 700+ entries missing in a 300k dataset via Unique Count in Elastic which are otherwise really unique.

Read more here: https://www.elastic.co/guide/en/elasticsearch/guide/current/cardinality.html

Export table from database to csv file

And when you want all tables for some reason ?

You can generate these commands in SSMS:

SELECT 
CONCAT('sqlcmd -S ',
'Your(local?)SERVERhere'
,' -d',
'YourDB'
,' -E -s, -W -Q "SELECT * FROM ',
TABLE_NAME,
'" >',
TABLE_NAME,
'.csv') FROM INFORMATION_SCHEMA.TABLES

And get again rows like this

sqlcmd -S ... -d... -E -s, -W -Q "SELECT * FROM table1" >table1.csv
sqlcmd -S ... -d... -E -s, -W -Q "SELECT * FROM table2" >table2.csv
...

There is also option to use better TAB as delimiter, but it would need a strange Unicode character - using Alt+9 in CMD, it came like this ? (Unicode CB25), but works only by copy/paste to command line not in batch.

What is the behavior of integer division?

Where the result is negative, C truncates towards 0 rather than flooring - I learnt this reading about why Python integer division always floors here: Why Python's Integer Division Floors

Rails: select unique values from a column

If you're going to use Model.select, then you might as well just use DISTINCT, as it will return only the unique values. This is better because it means it returns less rows and should be slightly faster than returning a number of rows and then telling Rails to pick the unique values.

Model.select('DISTINCT rating')

Of course, this is provided your database understands the DISTINCT keyword, and most should.

Proper use of errors

Don't forget about switch statements:

  • Ensure handling with default.
  • instanceof can match on superclass.
  • ES6 constructor will match on the exact class.
  • Easier to read.

_x000D_
_x000D_
function handleError() {_x000D_
    try {_x000D_
        throw new RangeError();_x000D_
    }_x000D_
    catch (e) {_x000D_
        switch (e.constructor) {_x000D_
            case Error:      return console.log('generic');_x000D_
            case RangeError: return console.log('range');_x000D_
            default:         return console.log('unknown');_x000D_
        }_x000D_
    }_x000D_
}_x000D_
_x000D_
handleError();
_x000D_
_x000D_
_x000D_

How to change RGB color to HSV?

Note that Color.GetSaturation() and Color.GetBrightness() return HSL values, not HSV.
The following code demonstrates the difference.

Color original = Color.FromArgb(50, 120, 200);
// original = {Name=ff3278c8, ARGB=(255, 50, 120, 200)}

double hue;
double saturation;
double value;
ColorToHSV(original, out hue, out saturation, out value);
// hue        = 212.0
// saturation = 0.75
// value      = 0.78431372549019607

Color copy = ColorFromHSV(hue, saturation, value);
// copy = {Name=ff3278c8, ARGB=(255, 50, 120, 200)}

// Compare that to the HSL values that the .NET framework provides: 
original.GetHue();        // 212.0
original.GetSaturation(); // 0.6
original.GetBrightness(); // 0.490196079

The following C# code is what you want. It converts between RGB and HSV using the algorithms described on Wikipedia. The ranges are 0 - 360 for hue, and 0 - 1 for saturation or value.

public static void ColorToHSV(Color color, out double hue, out double saturation, out double value)
{
    int max = Math.Max(color.R, Math.Max(color.G, color.B));
    int min = Math.Min(color.R, Math.Min(color.G, color.B));

    hue = color.GetHue();
    saturation = (max == 0) ? 0 : 1d - (1d * min / max);
    value = max / 255d;
}

public static Color ColorFromHSV(double hue, double saturation, double value)
{
    int hi = Convert.ToInt32(Math.Floor(hue / 60)) % 6;
    double f = hue / 60 - Math.Floor(hue / 60);

    value = value * 255;
    int v = Convert.ToInt32(value);
    int p = Convert.ToInt32(value * (1 - saturation));
    int q = Convert.ToInt32(value * (1 - f * saturation));
    int t = Convert.ToInt32(value * (1 - (1 - f) * saturation));

    if (hi == 0)
        return Color.FromArgb(255, v, t, p);
    else if (hi == 1)
        return Color.FromArgb(255, q, v, p);
    else if (hi == 2)
        return Color.FromArgb(255, p, v, t);
    else if (hi == 3)
        return Color.FromArgb(255, p, q, v);
    else if (hi == 4)
        return Color.FromArgb(255, t, p, v);
    else
        return Color.FromArgb(255, v, p, q);
}

INNER JOIN vs INNER JOIN (SELECT . FROM)

You are correct. You did exactly the right thing, checking the query plan rather than trying to second-guess the optimiser. :-)

Efficiently updating database using SQLAlchemy ORM

If it is because of the overhead in terms of creating objects, then it probably can't be sped up at all with SA.

If it is because it is loading up related objects, then you might be able to do something with lazy loading. Are there lots of objects being created due to references? (IE, getting a Company object also gets all of the related People objects).

Convert JSON String To C# Object

add this ddl to reference to your project: System.Web.Extensions.dll

use this namespace: using System.Web.Script.Serialization;

public class IdName
{
    public int Id { get; set; }
    public string Name { get; set; }
}


   string jsonStringSingle = "{'Id': 1, 'Name':'Thulasi Ram.S'}".Replace("'", "\"");
   var entity = new JavaScriptSerializer().Deserialize<IdName>(jsonStringSingle);

   string jsonStringCollection = "[{'Id': 2, 'Name':'Thulasi Ram.S'},{'Id': 2, 'Name':'Raja Ram.S'},{'Id': 3, 'Name':'Ram.S'}]".Replace("'", "\"");
   var collection = new JavaScriptSerializer().Deserialize<IEnumerable<IdName>>(jsonStringCollection);

jQuery or Javascript - how to disable window scroll without overflow:hidden;

You can use jquery-disablescroll to solve the problem:

  • Disable scrolling: $window.disablescroll();
  • Enable scrolling again: $window.disablescroll("undo");

Supports handleWheel, handleScrollbar, handleKeys and scrollEventKeys.

Copy entire contents of a directory to another using php

Full thanks must go to Felix Kling for his excellent answer which I have gratefully used in my code. I offer a small enhancement of a boolean return value to report success or failure:

function recurse_copy($src, $dst) {

  $dir = opendir($src);
  $result = ($dir === false ? false : true);

  if ($result !== false) {
    $result = @mkdir($dst);

    if ($result === true) {
      while(false !== ( $file = readdir($dir)) ) { 
        if (( $file != '.' ) && ( $file != '..' ) && $result) { 
          if ( is_dir($src . '/' . $file) ) { 
            $result = recurse_copy($src . '/' . $file,$dst . '/' . $file); 
          }     else { 
            $result = copy($src . '/' . $file,$dst . '/' . $file); 
          } 
        } 
      } 
      closedir($dir);
    }
  }

  return $result;
}

How to generate an entity-relationship (ER) diagram using Oracle SQL Developer

I'm running SQL Developer 17.2.0.188 build 188.1159 which does indeed contain data modeling capability. I just created a relational model diagram via the menu: File->Data Modeler->Import->Data Dictionary....

I also have the stand-alone Data Modeler, which does the same thing.

As the Data Modeler tutorial states:

Figure 4: Relational model and diagram for HR

The diagram you’ve generated is not an ERD. Logical models are higher abstractions. An ERD represents entities and their attributes and relations, whereas a relational or physical model represents tables, columns, and foreign keys."

SVG: text inside rect

<svg xmlns="http://www.w3.org/2000/svg" version="1.1">
    <g>
  <defs>
    <linearGradient id="grad1" x1="0%" y1="0%" x2="100%" y2="0%">
      <stop offset="0%" style="stop-color:rgb(145,200,103);stop-opacity:1" />
      <stop offset="100%" style="stop-color:rgb(132,168,86);stop-opacity:1" />
    </linearGradient>
  </defs>
  <rect width="220" height="30" class="GradientBorder" fill="url(#grad1)" />
  <text x="60" y="20" font-family="Calibri" font-size="20" fill="white" >My Code , Your Achivement....... </text>
  </g>
</svg> 

What is the proper way to comment functions in Python?

You can use three quotes to do it.

You can use single quotes:

def myfunction(para1,para2):
  '''
  The stuff inside the function
  '''

Or double quotes:

def myfunction(para1,para2):
  """
  The stuff inside the function
  """

Fastest way to download a GitHub project

There is a new (sometime pre April 2013) option on the site that says "Clone in Windows".

This works very nicely if you already have the Windows GitHub Client as mentioned by @Tommy in his answer on this related question (How to download source in ZIP format from GitHub?).

Microsoft Excel mangles Diacritics in .csv files?

This is just of a question of character encodings. It looks like you're exporting your data as UTF-8: é in UTF-8 is the two-byte sequence 0xC3 0xA9, which when interpreted in Windows-1252 is é. When you import your data into Excel, make sure to tell it that the character encoding you're using is UTF-8.

How to get the parents of a Python class?

Use the following attribute:

cls.__bases__

From the docs:

The tuple of base classes of a class object.

Example:

>>> str.__bases__
(<type 'basestring'>,)

Another example:

>>> class A(object):
...   pass
... 
>>> class B(object):
...   pass
... 
>>> class C(A, B):
...   pass
... 
>>> C.__bases__
(<class '__main__.A'>, <class '__main__.B'>)

How to load my app from Eclipse to my Android phone instead of AVD

Some people may have the issue where your phone might not immediately get recognized by the computer as an emulator, especially if you're given the option to choose why your phone is connected to the computer on your phone. These options are:

  • charge only
  • Media device (MTP)
  • Camera file transfer (PTP)
  • Share mobile network
  • Install driver

Of these options, choose MTP and follow the instructions found in the quotes of other answers.

  • Hope this helps!

goto run menu -> run configuration. right click on android application on the right side and click new. fill the corresponding details like project name under the android tab. then under the target tab. select 'launch on all compatible devices and then select active devices from the drop down list'. save the configuration and run it by either clicking run on the 'run' button on the bottom right side of the window or close the window and run again

Stretch horizontal ul to fit width of div

I Hope that this helps you out... Because I tried all the answers but nothing worked perfectly. So, I had to come up with a solution on my own.

#horizontal-style {
  padding-inline-start: 0 !important; // Just in case if you find that there is an extra padding at the start of the line 
  justify-content: space-around;
  display: flex;
}

#horizontal-style a {
    text-align: center;
    color: white;
    text-decoration: none;
}

Build Step Progress Bar (css and jquery)

I had the same requirements to create a kind of step progress tracker so I created a JavaScript plugin for that purpose. Here is the JsFiddle for the demo for this step progress tracker. You can access its code on GitHub as well.

What it basically does is, it takes the json data(in a particular format described below) as input and creates the progress tracker based on that. Highlighted steps indicates the completed steps.

It's html will somewhat look like shown below with default CSS but you can customize it as per the theme of your application. There is an option to show tool-tip text for each steps as well.

Here is some code snippet for that:

//container div 
<div id="tracker1" style="width: 700px">
</div>

//sample JSON data
var sampleJson1 = {
ToolTipPosition: "bottom",
data: [{ order: 1, Text: "Foo", ToolTipText: "Step1-Foo", highlighted: true },
    { order: 2, Text: "Bar", ToolTipText: "Step2-Bar", highlighted: true },
    { order: 3, Text: "Baz", ToolTipText: "Step3-Baz", highlighted: false },
    { order: 4, Text: "Quux", ToolTipText: "Step4-Quux", highlighted: false }]
};    

//Invoking the plugin
$(document).ready(function () {
        $("#tracker1").progressTracker(sampleJson1);
    });

Hopefully it will be useful for somebody else as well!

enter image description here

Understanding timedelta

why do I have to pass seconds = uptime to timedelta

Because timedelta objects can be passed seconds, milliseconds, days, etc... so you need to specify what are you passing in (this is why you use the explicit key). Typecasting to int is superfluous as they could also accept floats.

and why does the string casting works so nicely that I get HH:MM:SS ?

It's not the typecasting that formats, is the internal __str__ method of the object. In fact you will achieve the same result if you write:

print datetime.timedelta(seconds=int(uptime))

How to debug Google Apps Script (aka where does Logger.log log to?)

just debug your spreadsheet code like this:

...
throw whatAmI;
...

shows like this:

enter image description here

How do I style appcompat-v7 Toolbar like Theme.AppCompat.Light.DarkActionBar?

The cleanest way I found to do this is create a child of 'ThemeOverlay.AppCompat.Dark.ActionBar'. In the example, I set the Toolbar's background color to RED and text's color to BLUE.

<style name="MyToolbar" parent="ThemeOverlay.AppCompat.Dark.ActionBar">
    <item name="android:background">#FF0000</item>
    <item name="android:textColorPrimary">#0000FF</item>
</style>

You can then apply your theme to the toolbar:

<android.support.v7.widget.Toolbar
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_height="wrap_content"
    android:layout_width="match_parent"
    app:theme="@style/MyToolbar"
    android:minHeight="?attr/actionBarSize"/>

Int to Decimal Conversion - Insert decimal point at specified location

Declare it as a decimal which uses the int variable and divide this by 100

int number = 700
decimal correctNumber = (decimal)number / 100;

Edit: Bala was faster with his reaction

What is the difference between Views and Materialized Views in Oracle?

A view uses a query to pull data from the underlying tables.

A materialized view is a table on disk that contains the result set of a query.

Materialized views are primarily used to increase application performance when it isn't feasible or desirable to use a standard view with indexes applied to it. Materialized views can be updated on a regular basis either through triggers or by using the ON COMMIT REFRESH option. This does require a few extra permissions, but it's nothing complex. ON COMMIT REFRESH has been in place since at least Oracle 10.

Edit and Continue: "Changes are not allowed when..."

I ran into this today - turns out that having Debug Info set to pdb-only (or none, I'd imagine) will prevent Edit and Continue from working.

Make sure your Debug Info is set to "full" first!

Project Properties > Build > Advanced > Output > Debug Info

Mobile Redirect using htaccess

You can also try this. Credits to the original author who has since removed the script

/mobile.class.php

<?php
/*
=====================================================
Mobile version detection
-----------------------------------------------------
compliments of http://www.buchfelder.biz/
=====================================================
*/

$mobile = "http://www.stepforth.mobi";
$text = $_SERVER['HTTP_USER_AGENT'];
$var[0] = 'Mozilla/4.';
$var[1] = 'Mozilla/3.0';
$var[2] = 'AvantGo';
$var[3] = 'ProxiNet';
$var[4] = 'Danger hiptop 1.0';
$var[5] = 'DoCoMo/';
$var[6] = 'Google CHTML Proxy/';
$var[7] = 'UP.Browser/';
$var[8] = 'SEMC-Browser/';
$var[9] = 'J-PHONE/';
$var[10] = 'PDXGW/';
$var[11] = 'ASTEL/';
$var[12] = 'Mozilla/1.22';
$var[13] = 'Handspring';
$var[14] = 'Windows CE';
$var[15] = 'PPC';
$var[16] = 'Mozilla/2.0';
$var[17] = 'Blazer/';
$var[18] = 'Palm';
$var[19] = 'WebPro/';
$var[20] = 'EPOC32-WTL/';
$var[21] = 'Tungsten';
$var[22] = 'Netfront/';
$var[23] = 'Mobile Content Viewer/';
$var[24] = 'PDA';
$var[25] = 'MMP/2.0';
$var[26] = 'Embedix/';
$var[27] = 'Qtopia/';
$var[28] = 'Xiino/';
$var[29] = 'BlackBerry';
$var[30] = 'Gecko/20031007';
$var[31] = 'MOT-';
$var[32] = 'UP.Link/';
$var[33] = 'Smartphone';
$var[34] = 'portalmmm/';
$var[35] = 'Nokia';
$var[36] = 'Symbian';
$var[37] = 'AppleWebKit/413';
$var[38] = 'UPG1 UP/';
$var[39] = 'RegKing';
$var[40] = 'STNC-WTL/';
$var[41] = 'J2ME';
$var[42] = 'Opera Mini/';
$var[43] = 'SEC-';
$var[44] = 'ReqwirelessWeb/';
$var[45] = 'AU-MIC/';
$var[46] = 'Sharp';
$var[47] = 'SIE-';
$var[48] = 'SonyEricsson';
$var[49] = 'Elaine/';
$var[50] = 'SAMSUNG-';
$var[51] = 'Panasonic';
$var[52] = 'Siemens';
$var[53] = 'Sony';
$var[54] = 'Verizon';
$var[55] = 'Cingular';
$var[56] = 'Sprint';
$var[57] = 'AT&T;';
$var[58] = 'Nextel';
$var[59] = 'Pocket PC';
$var[60] = 'T-Mobile';    
$var[61] = 'Orange';
$var[62] = 'Casio';
$var[63] = 'HTC';
$var[64] = 'Motorola';
$var[65] = 'Samsung';
$var[66] = 'NEC';

$result = count($var);

for ($i=0;$i<$result;$i++)
{    
    $ausg = stristr($text, $var[$i]);    
    if(strlen($ausg)>0)
    {
        header("location: $mobile");
        exit;
    }

}
?>

Just edit the $mobile = "http://www.stepforth.mobi";

java.lang.ClassNotFoundException: org.apache.jsp.index_jsp

What version of tomcat are you using ? What appears to me is that the tomcat version is not supporting the servlet & jsp versions you're using. You can change to something like below or look into your version of tomcat on what it supports and change the versions accordingly.

 <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>javax.servlet-api</artifactId>
            <version>3.0.1</version>
            <scope>provided</scope>
        </dependency>
        <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>jsp-api</artifactId>
            <version>2.0</version>
            <scope>provided</scope>
        </dependency>

ASP.NET Web Application Message Box

Why should not use jquery popup for this purpose.I use bpopup for this purpose.See more about this.
http://dinbror.dk/bpopup/

How do I remove a substring from the end of a string in Python?

Because this is a very popular question i add another, now available, solution. With python 3.9 (https://docs.python.org/3.9/whatsnew/3.9.html) the function removesuffix() will be added (and removeprefix()) and this function is exactly what was questioned here.

url = 'abcdc.com'
print(url.removesuffix('.com'))

output:

'abcdc'

PEP 616 (https://www.python.org/dev/peps/pep-0616/) shows how it will behave (it is not the real implementation):

def removeprefix(self: str, prefix: str, /) -> str:
    if self.startswith(prefix):
        return self[len(prefix):]
    else:
        return self[:]

and what benefits it has against self-implemented solutions:

  1. Less fragile: The code will not depend on the user to count the length of a literal.

  2. More performant: The code does not require a call to the Python built-in len function nor to the more expensive str.replace() method.

  3. More descriptive: The methods give a higher-level API for code readability as opposed to the traditional method of string slicing.

Change icons of checked and unchecked for Checkbox for Android

I realize this is an old question, and the OP is talking about using custom gx that aren't necessary 'checkbox'-looking, but there is a fantastic resource for generating custom colored assets here: http://kobroor.pl/

Just give it the relevant details and it spits out graphics, complete with xml resources, that you can just drop right in.

How to unpack and pack pkg file?

Here is a bash script inspired by abarnert's answer which will unpack a package named MyPackage.pkg into a subfolder named MyPackage_pkg and then open the folder in Finder.

    #!/usr/bin/env bash
    filename="$*"
    dirname="${filename/\./_}"
    pkgutil --expand "$filename" "$dirname"
    cd "$dirname"
    tar xvf Payload
    open .

Usage:

    pkg-upack.sh MyPackage.pkg

Warning: This will not work in all cases, and will fail with certain files, e.g. the PKGs inside the OSX system installer. If you want to peek inside the pkg file and see what's inside, you can try SuspiciousPackage (free app), and if you need more options such as selectively unpacking specific files, then have a look at Pacifist (nagware).

How to square all the values in a vector in R?

This will also work

newData <- data*data

Duplicate Entire MySQL Database

For me the following lines of code did the trick

mysqldump --quote-names -q -u username1 --password='password1' originalDB | mysql -u username2 --password='password2' duplicateDB

Total memory used by Python process?

Below is my function decorator which allows to track how much memory this process consumed before the function call, how much memory it uses after the function call, and how long the function is executed.

import time
import os
import psutil


def elapsed_since(start):
    return time.strftime("%H:%M:%S", time.gmtime(time.time() - start))


def get_process_memory():
    process = psutil.Process(os.getpid())
    return process.memory_info().rss


def track(func):
    def wrapper(*args, **kwargs):
        mem_before = get_process_memory()
        start = time.time()
        result = func(*args, **kwargs)
        elapsed_time = elapsed_since(start)
        mem_after = get_process_memory()
        print("{}: memory before: {:,}, after: {:,}, consumed: {:,}; exec time: {}".format(
            func.__name__,
            mem_before, mem_after, mem_after - mem_before,
            elapsed_time))
        return result
    return wrapper

So, when you have some function decorated with it

from utils import track

@track
def list_create(n):
    print("inside list create")
    return [1] * n

You will be able to see this output:

inside list create
list_create: memory before: 45,928,448, after: 46,211,072, consumed: 282,624; exec time: 00:00:00

How to handle configuration in Go

I tried JSON. It worked. But I hate having to create the struct of the exact fields and types I might be setting. To me that was a pain. I noticed it was the method used by all the configuration options I could find. Maybe my background in dynamic languages makes me blind to the benefits of such verboseness. I made a new simple config file format, and a more dynamic-ish lib for reading it out.

https://github.com/chrisftw/ezconf

I am pretty new to the Go world, so it might not be the Go way. But it works, it is pretty quick, and super simple to use.

Pros

  • Super simple
  • Less code

Cons

  • No Arrays or Map types
  • Very flat file format
  • Non-standard conf files
  • Does have a little convention built-in, which I now if frowned upon in general in Go community. (Looks for config file in the config directory)

How to integrate SAP Crystal Reports in Visual Studio 2017

I had the same problem and I solved by installing Service pack 22 and it fixed it.

Richtextbox wpf binding

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

afxwin.h file is missing in VC++ Express Edition

Found this post that may help: http://social.msdn.microsoft.com/forums/en-US/Vsexpressvc/thread/7c274008-80eb-42a0-a79b-95f5afbf6528/

Or shortly, afxwin.h is MFC and MFC is not included in the free version of VC++ (Express Edition).

close vs shutdown socket?

None of the existing answers tell people how shutdown and close works at the TCP protocol level, so it is worth to add this.

A standard TCP connection gets terminated by 4-way finalization:

  1. Once a participant has no more data to send, it sends a FIN packet to the other
  2. The other party returns an ACK for the FIN.
  3. When the other party also finished data transfer, it sends another FIN packet
  4. The initial participant returns an ACK and finalizes transfer.

However, there is another "emergent" way to close a TCP connection:

  1. A participant sends an RST packet and abandons the connection
  2. The other side receives an RST and then abandon the connection as well

In my test with Wireshark, with default socket options, shutdown sends a FIN packet to the other end but it is all it does. Until the other party send you the FIN packet you are still able to receive data. Once this happened, your Receive will get an 0 size result. So if you are the first one to shut down "send", you should close the socket once you finished receiving data.

On the other hand, if you call close whilst the connection is still active (the other side is still active and you may have unsent data in the system buffer as well), an RST packet will be sent to the other side. This is good for errors. For example, if you think the other party provided wrong data or it refused to provide data (DOS attack?), you can close the socket straight away.

My opinion of rules would be:

  1. Consider shutdown before close when possible
  2. If you finished receiving (0 size data received) before you decided to shutdown, close the connection after the last send (if any) finished.
  3. If you want to close the connection normally, shutdown the connection (with SHUT_WR, and if you don't care about receiving data after this point, with SHUT_RD as well), and wait until you receive a 0 size data, and then close the socket.
  4. In any case, if any other error occurred (timeout for example), simply close the socket.

Ideal implementations for SHUT_RD and SHUT_WR

The following haven't been tested, trust at your own risk. However, I believe this is a reasonable and practical way of doing things.

If the TCP stack receives a shutdown with SHUT_RD only, it shall mark this connection as no more data expected. Any pending and subsequent read requests (regardless whichever thread they are in) will then returned with zero sized result. However, the connection is still active and usable -- you can still receive OOB data, for example. Also, the OS will drop any data it receives for this connection. But that is all, no packages will be sent to the other side.

If the TCP stack receives a shutdown with SHUT_WR only, it shall mark this connection as no more data can be sent. All pending write requests will be finished, but subsequent write requests will fail. Furthermore, a FIN packet will be sent to another side to inform them we don't have more data to send.

How do I replace all line breaks in a string with <br /> elements?

If the accepted answer isn't working right for you then you might try.

str.replace(new RegExp('\n','g'), '<br />')

It worked for me.

Get HTML code from website in C#

Getting HTML code from a website. You can use code like this.

string urlAddress = "http://google.com";

HttpWebRequest request = (HttpWebRequest)WebRequest.Create(urlAddress);
HttpWebResponse response = (HttpWebResponse)request.GetResponse();

if (response.StatusCode == HttpStatusCode.OK)
{
  Stream receiveStream = response.GetResponseStream();
  StreamReader readStream = null;

  if (String.IsNullOrWhiteSpace(response.CharacterSet))
     readStream = new StreamReader(receiveStream);
  else
     readStream = new StreamReader(receiveStream, Encoding.GetEncoding(response.CharacterSet));

  string data = readStream.ReadToEnd();

  response.Close();
  readStream.Close();
}

This will give you the returned HTML code from the website. But find text via LINQ is not that easy. Perhaps it is better to use regular expression but that does not play well with HTML code

How do you read scanf until EOF in C?

Try:

while(scanf("%15s", words) != EOF)

You need to compare scanf output with EOF

Since you are specifying a width of 15 in the format string, you'll read at most 15 char. So the words char array should be of size 16 ( 15 +1 for null char). So declare it as:

char words[16];

Resizing Images in VB.NET

Here is an article with full details on how to do this.

Private Sub btnScale_Click(ByVal sender As System.Object, _
    ByVal e As System.EventArgs) Handles btnScale.Click
    ' Get the scale factor.
    Dim scale_factor As Single = Single.Parse(txtScale.Text)

    ' Get the source bitmap.
    Dim bm_source As New Bitmap(picSource.Image)

    ' Make a bitmap for the result.
    Dim bm_dest As New Bitmap( _
        CInt(bm_source.Width * scale_factor), _
        CInt(bm_source.Height * scale_factor))

    ' Make a Graphics object for the result Bitmap.
    Dim gr_dest As Graphics = Graphics.FromImage(bm_dest)

    ' Copy the source image into the destination bitmap.
    gr_dest.DrawImage(bm_source, 0, 0, _
        bm_dest.Width + 1, _
        bm_dest.Height + 1)

    ' Display the result.
    picDest.Image = bm_dest
End Sub

[Edit]
One more on the similar lines.

What does <value optimized out> mean in gdb?

Minimal runnable example with disassembly analysis

As usual, I like to see some disassembly to get a better understanding of what is going on.

In this case, the insight we obtain is that if a variable is optimized to be stored only in a register rather than the stack, and then the register it was in gets overwritten, then it shows as <optimized out> as mentioned by R..

Of course, this can only happen if the variable in question is not needed anymore, otherwise the program would lose its value. Therefore it tends to happen that at the start of the function you can see the variable value, but then at the end it becomes <optimized out>.

One typical case which we often are interested in of this is that of the function arguments themselves, since these are:

  • always defined at the start of the function
  • may not get used towards the end of the function as more intermediate values are calculated.
  • tend to get overwritten by further function subcalls which must setup the exact same registers to satisfy the calling convention

This understanding actually has a concrete application: when using reverse debugging, you might be able to recover the value of variables of interest simply by stepping back to their last point of usage: How do I view the value of an <optimized out> variable in C++?

main.c

#include <stdio.h>

int __attribute__((noinline)) f3(int i) {
    return i + 1;
}

int __attribute__((noinline)) f2(int i) {
    return f3(i) + 1;
}

int __attribute__((noinline)) f1(int i) {
    int j = 1, k = 2, l = 3;
    i += 1;
    j += f2(i);
    k += f2(j);
    l += f2(k);
    return l;
}

int main(int argc, char *argv[]) {
    printf("%d\n", f1(argc));
    return 0;
}

Compile and run:

gcc -ggdb3 -O3 -std=c99 -Wall -Wextra -pedantic -o main.out main.c
gdb -q -nh main.out

Then inside GDB, we have the following session:

Breakpoint 1, f1 (i=1) at main.c:13
13          i += 1;
(gdb) disas
Dump of assembler code for function f1:
=> 0x00005555555546c0 <+0>:     add    $0x1,%edi
   0x00005555555546c3 <+3>:     callq  0x5555555546b0 <f2>
   0x00005555555546c8 <+8>:     lea    0x1(%rax),%edi
   0x00005555555546cb <+11>:    callq  0x5555555546b0 <f2>
   0x00005555555546d0 <+16>:    lea    0x2(%rax),%edi
   0x00005555555546d3 <+19>:    callq  0x5555555546b0 <f2>
   0x00005555555546d8 <+24>:    add    $0x3,%eax
   0x00005555555546db <+27>:    retq   
End of assembler dump.
(gdb) p i
$1 = 1
(gdb) p j
$2 = 1
(gdb) n
14          j += f2(i);
(gdb) disas
Dump of assembler code for function f1:
   0x00005555555546c0 <+0>:     add    $0x1,%edi
=> 0x00005555555546c3 <+3>:     callq  0x5555555546b0 <f2>
   0x00005555555546c8 <+8>:     lea    0x1(%rax),%edi
   0x00005555555546cb <+11>:    callq  0x5555555546b0 <f2>
   0x00005555555546d0 <+16>:    lea    0x2(%rax),%edi
   0x00005555555546d3 <+19>:    callq  0x5555555546b0 <f2>
   0x00005555555546d8 <+24>:    add    $0x3,%eax
   0x00005555555546db <+27>:    retq   
End of assembler dump.
(gdb) p i
$3 = 2
(gdb) p j
$4 = 1
(gdb) n
15          k += f2(j);
(gdb) disas
Dump of assembler code for function f1:
   0x00005555555546c0 <+0>:     add    $0x1,%edi
   0x00005555555546c3 <+3>:     callq  0x5555555546b0 <f2>
   0x00005555555546c8 <+8>:     lea    0x1(%rax),%edi
=> 0x00005555555546cb <+11>:    callq  0x5555555546b0 <f2>
   0x00005555555546d0 <+16>:    lea    0x2(%rax),%edi
   0x00005555555546d3 <+19>:    callq  0x5555555546b0 <f2>
   0x00005555555546d8 <+24>:    add    $0x3,%eax
   0x00005555555546db <+27>:    retq   
End of assembler dump.
(gdb) p i
$5 = <optimized out>
(gdb) p j
$6 = 5
(gdb) n
16          l += f2(k);
(gdb) disas
Dump of assembler code for function f1:
   0x00005555555546c0 <+0>:     add    $0x1,%edi
   0x00005555555546c3 <+3>:     callq  0x5555555546b0 <f2>
   0x00005555555546c8 <+8>:     lea    0x1(%rax),%edi
   0x00005555555546cb <+11>:    callq  0x5555555546b0 <f2>
   0x00005555555546d0 <+16>:    lea    0x2(%rax),%edi
=> 0x00005555555546d3 <+19>:    callq  0x5555555546b0 <f2>
   0x00005555555546d8 <+24>:    add    $0x3,%eax
   0x00005555555546db <+27>:    retq   
End of assembler dump.
(gdb) p i
$7 = <optimized out>
(gdb) p j
$8 = <optimized out>

To understand what is going on, remember from the x86 Linux calling convention: What are the calling conventions for UNIX & Linux system calls on i386 and x86-64 you should know that:

  • RDI contains the first argument
  • RDI can get destroyed in function calls
  • RAX contains the return value

From this we deduce that:

add    $0x1,%edi

corresponds to the:

i += 1;

since i is the first argument of f1, and therefore stored in RDI.

Now, while we were at both:

i += 1;
j += f2(i);

the value of RDI hadn't been modified, and therefore GDB could just query it at anytime in those lines.

However, as soon as the f2 call is made:

  • the value of i is not needed anymore in the program
  • lea 0x1(%rax),%edi does EDI = j + RAX + 1, which both:
    • initializes j = 1
    • sets up the first argument of the next f2 call to RDI = j

Therefore, when the following line is reached:

k += f2(j);

both of the following instructions have/may have modified RDI, which is the only place i was being stored (f2 may use it as a scratch register, and lea definitely set it to RAX + 1):

   0x00005555555546c3 <+3>:     callq  0x5555555546b0 <f2>
   0x00005555555546c8 <+8>:     lea    0x1(%rax),%edi

and so RDI does not contain the value of i anymore. In fact, the value of i was completely lost! Therefore the only possible outcome is:

$3 = <optimized out>

A similar thing happens to the value of j, although j only becomes unnecessary one line later afer the call to k += f2(j);.

Thinking about j also gives us some insight on how smart GDB is. Notably, at i += 1;, the value of j had not yet materialized in any register or memory address, and GDB must have known it based solely on debug information metadata.

-O0 analysis

If we use -O0 instead of -O3 for compilation:

gcc -ggdb3 -O0 -std=c99 -Wall -Wextra -pedantic -o main.out main.c

then the disassembly would look like:

11      int __attribute__((noinline)) f1(int i) {
=> 0x0000555555554673 <+0>:     55      push   %rbp
   0x0000555555554674 <+1>:     48 89 e5        mov    %rsp,%rbp
   0x0000555555554677 <+4>:     48 83 ec 18     sub    $0x18,%rsp
   0x000055555555467b <+8>:     89 7d ec        mov    %edi,-0x14(%rbp)

12          int j = 1, k = 2, l = 3;
   0x000055555555467e <+11>:    c7 45 f4 01 00 00 00    movl   $0x1,-0xc(%rbp)
   0x0000555555554685 <+18>:    c7 45 f8 02 00 00 00    movl   $0x2,-0x8(%rbp)
   0x000055555555468c <+25>:    c7 45 fc 03 00 00 00    movl   $0x3,-0x4(%rbp)

13          i += 1;
   0x0000555555554693 <+32>:    83 45 ec 01     addl   $0x1,-0x14(%rbp)

14          j += f2(i);
   0x0000555555554697 <+36>:    8b 45 ec        mov    -0x14(%rbp),%eax
   0x000055555555469a <+39>:    89 c7   mov    %eax,%edi
   0x000055555555469c <+41>:    e8 b8 ff ff ff  callq  0x555555554659 <f2>
   0x00005555555546a1 <+46>:    01 45 f4        add    %eax,-0xc(%rbp)

15          k += f2(j);
   0x00005555555546a4 <+49>:    8b 45 f4        mov    -0xc(%rbp),%eax
   0x00005555555546a7 <+52>:    89 c7   mov    %eax,%edi
   0x00005555555546a9 <+54>:    e8 ab ff ff ff  callq  0x555555554659 <f2>
   0x00005555555546ae <+59>:    01 45 f8        add    %eax,-0x8(%rbp)

16          l += f2(k);
   0x00005555555546b1 <+62>:    8b 45 f8        mov    -0x8(%rbp),%eax
   0x00005555555546b4 <+65>:    89 c7   mov    %eax,%edi
   0x00005555555546b6 <+67>:    e8 9e ff ff ff  callq  0x555555554659 <f2>
   0x00005555555546bb <+72>:    01 45 fc        add    %eax,-0x4(%rbp)

17          return l;
   0x00005555555546be <+75>:    8b 45 fc        mov    -0x4(%rbp),%eax

18      }
   0x00005555555546c1 <+78>:    c9      leaveq 
   0x00005555555546c2 <+79>:    c3      retq 

From this horrendous disassembly, we see that the value of RDI is moved to the stack at the very start of program execution at:

mov    %edi,-0x14(%rbp)

and it then gets retrieved from memory into registers whenever needed, e.g. at:

14          j += f2(i);
   0x0000555555554697 <+36>:    8b 45 ec        mov    -0x14(%rbp),%eax
   0x000055555555469a <+39>:    89 c7   mov    %eax,%edi
   0x000055555555469c <+41>:    e8 b8 ff ff ff  callq  0x555555554659 <f2>
   0x00005555555546a1 <+46>:    01 45 f4        add    %eax,-0xc(%rbp)

The same basically happens to j which gets immediately pushed to the stack when when it is initialized:

   0x000055555555467e <+11>:    c7 45 f4 01 00 00 00    movl   $0x1,-0xc(%rbp)

Therefore, it is easy for GDB to find the values of those variables at any time: they are always present in memory!

This also gives us some insight on why it is not possible to avoid <optimized out> in optimized code: since the number of registers is limited, the only way to do that would be to actually push unneeded registers to memory, which would partly defeat the benefit of -O3.

Extend the lifetime of i

If we edited f1 to return l + i as in:

int __attribute__((noinline)) f1(int i) {
    int j = 1, k = 2, l = 3;
    i += 1;
    j += f2(i);
    k += f2(j);
    l += f2(k);
    return l + i;
}

then we observe that this effectively extends the visibility of i until the end of the function.

This is because with this we force GCC to use an extra variable to keep i around until the end:

   0x00005555555546c0 <+0>:     lea    0x1(%rdi),%edx
   0x00005555555546c3 <+3>:     mov    %edx,%edi
   0x00005555555546c5 <+5>:     callq  0x5555555546b0 <f2>
   0x00005555555546ca <+10>:    lea    0x1(%rax),%edi
   0x00005555555546cd <+13>:    callq  0x5555555546b0 <f2>
   0x00005555555546d2 <+18>:    lea    0x2(%rax),%edi
   0x00005555555546d5 <+21>:    callq  0x5555555546b0 <f2>
   0x00005555555546da <+26>:    lea    0x3(%rdx,%rax,1),%eax
   0x00005555555546de <+30>:    retq

which the compiler does by storing i += i in RDX at the very first instruction.

Tested in Ubuntu 18.04, GCC 7.4.0, GDB 8.1.0.

CS0120: An object reference is required for the nonstatic field, method, or property 'foo'

From my looking you give a null value to a textbox and return in a ToString() as it is a static method. You can replace it with Convert.ToString() that can enable null value.

CodeIgniter Disallowed Key Characters

I had the same problem thanks to french specials characters. Here is my class in case anybody needs it. It has to be saved here : /application/core/MY_Input.php

(also this extension will report witch character is not allowed in the future)

class MY_Input extends CI_Input {

function __construct() { parent::__construct(); } /** * Clean Keys * * This is a helper function. To prevent malicious users * from trying to exploit keys we make sure that keys are * only named with alpha-numeric text and a few other items. * * @access private * @param string * @return string */ function _clean_input_keys($str) { if ( ! preg_match("/^[a-z0-9:_\/-àâçéèêëîôùû]+$/i", $str)) { exit('Disallowed Key Characters : '.$str); } // Clean UTF-8 if supported if (UTF8_ENABLED === TRUE) { $str = $this->uni->clean_string($str); } return $str; }

}

Read The Friendly Manual about core classes extension : http://ellislab.com/codeigniter/user-guide/general/core_classes.html

Using Address Instead Of Longitude And Latitude With Google Maps API

You can parse the geolocation through the addresses. Create an Array with jquery like this:

//follow this structure
var addressesArray = [
  'Address Str.No, Postal Area/city'
]

//loop all the addresses and call a marker for each one
for (var x = 0; x < addressesArray.length; x++) {
  $.getJSON('http://maps.googleapis.com/maps/api/geocode/json?address='+addressesArray[x]+'&sensor=false', null, function (data) {
    var p = data.results[0].geometry.location
    var latlng = new google.maps.LatLng(p.lat, p.lng);
    //it will place marker based on the addresses, which they will be translated as geolocations.
    var aMarker= new google.maps.Marker({
      position: latlng,
      map: map
    });
  });
}

Also please note that Google limit your results if you don't have a business account with them, and you my get an error if you use too many addresses.

Rename a table in MySQL

Running The Alter Command

1.Click the SQL tab at the top.

2.In the text box enter the following command: ALTER TABLE exampletable RENAME TO new_table_name;

3.Click the go button.

source : https://my.bluehost.com/hosting/help/2158

jQuery: Check if button is clicked

$('#submit1, #submit2').click(function () {
   if (this.id == 'submit1') {
      alert('Submit 1 clicked');
   }
   else if (this.id == 'submit2') {
      alert('Submit 2 clicked');
   }
});

Remove a symlink to a directory

Assuming your setup is something like: ln -s /mnt/bar ~/foo, then you should be able to do a rm foo with no problem. If you can't, make sure you are the owner of the foo and have permission to write/execute the file. Removing foo will not touch bar, unless you do it recursively.

How to insert pandas dataframe via mysqldb into database?

This should do the trick:

import pandas as pd
import pymysql
pymysql.install_as_MySQLdb()
from sqlalchemy import create_engine

# Create engine
engine = create_engine('mysql://USER_NAME_HERE:PASS_HERE@HOST_ADRESS_HERE/DB_NAME_HERE')

# Create the connection and close it(whether successed of failed)
with engine.begin() as connection:
  df.to_sql(name='INSERT_TABLE_NAME_HERE/INSERT_NEW_TABLE_NAME', con=connection, if_exists='append', index=False)

How to check if internet connection is present in Java?

The code using NetworkInterface to wait for the network worked for me until I switched from fixed network address to DHCP. A slight enhancement makes it work also with DHCP:

Enumeration<NetworkInterface> interfaces = NetworkInterface.getNetworkInterfaces();
while (interfaces.hasMoreElements()) {
    NetworkInterface interf = interfaces.nextElement();
    if (interf.isUp() && !interf.isLoopback()) {
    List<InterfaceAddress> adrs = interf.getInterfaceAddresses();
    for (Iterator<InterfaceAddress> iter = adrs.iterator(); iter.hasNext();) {
        InterfaceAddress adr = iter.next();
        InetAddress inadr = adr.getAddress();
        if (inadr instanceof Inet4Address) return true;
            }
    }
}

This works for Java 7 in openSuse 13.1 for IPv4 network. The problem with the original code is that although the interface was up after resuming from suspend, an IPv4 network address was not yet assigned. After waiting for this assignment, the program can connect to servers. But I have no idea what to do in case of IPv6.

How to reload a page after the OK click on the Alert Page

use confirm box instead....

    var r = confirm("Successful Message!");
    if (r == true){
      window.location.reload();
    }

What is a regex to match ONLY an empty string?

As explained in http://www.regular-expressions.info/anchors.html under the section "Strings Ending with a Line Break", \Z will generally match before the end of the last newline in strings that end in a newline. If you want to only match the end of the string, you need to use \z. The exception to this rule is Python.

In other words, to exclusively match an empty string, you need to use /\A\z/.

string sanitizer for filename

Well, tempnam() will do it for you.

http://us2.php.net/manual/en/function.tempnam.php

but that creates an entirely new name.

To sanitize an existing string just restrict what your users can enter and make it letters, numbers, period, hyphen and underscore then sanitize with a simple regex. Check what characters need to be escaped or you could get false positives.

$sanitized = preg_replace('/[^a-zA-Z0-9\-\._]/','', $filename);

The "backspace" escape character '\b': unexpected behavior?

If you want a destructive backspace, you'll need something like

"\b \b"

i.e. a backspace, a space, and another backspace.

How to use ArrayList.addAll()?

You can use Google guava as such:

ImmutableList<char> dirs = ImmutableList.of('+', '-', '*', '^');

Angular 4 default radio button checked by default

You can use [(ngModel)], but you'll need to update your value to [value] otherwise the value is evaluating as a string. It would look like this:

<label>This rule is true if:</label>
<label class="form-check-inline">
    <input class="form-check-input" type="radio" name="mode" [value]="true" [(ngModel)]="rule.mode">
</label>
<label class="form-check-inline">
    <input class="form-check-input" type="radio" name="mode" [value]="false" [(ngModel)]="rule.mode">
</label>

If rule.mode is true, then that radio is selected. If it's false, then the other.

The difference really comes down to the value. value="true" really evaluates to the string 'true', whereas [value]="true" evaluates to the boolean true.

pip installation /usr/local/opt/python/bin/python2.7: bad interpreter: No such file or directory

Editing the first line of this file worked to me:

MBP-de-Jose:~ josejunior$ which python3

/usr/local/Cellar/python/3.7.3/bin/python3

MBP-de-Jose:~ josejunior$

before

#!/usr/local/opt/python/bin/python3.7

after

#!/usr/local/Cellar/python/3.7.3/bin/python3

How to add a class to body tag?

$('body').toggleClass("className");

perfectly works

PivotTable to show values, not sum of values

I fear this might turn out to BE the long way round but could depend on how big your data set is – presumably more than four months for example.

Assuming your data is in ColumnA:C and has column labels in Row 1, also that Month is formatted mmm(this last for ease of sorting):

  1. Sort the data by Name then Month
  2. Enter in D2 =IF(AND(A2=A1,C2=C1),D1+1,1) (One way to deal with what is the tricky issue of multiple entries for the same person for the same month).
  3. Create a pivot table from A1:D(last occupied row no.)
  4. Say insert in F1.
  5. Layout as in screenshot.

SO12803305 example

I’m hoping this would be adequate for your needs because pivot table should automatically update (provided range is appropriate) in response to additional data with refresh. If not (you hard taskmaster), continue but beware that the following steps would need to be repeated each time the source data changes.

  1. Copy pivot table and Paste Special/Values to, say, L1.
  2. Delete top row of copied range with shift cells up.
  3. Insert new cell at L1 and shift down.
  4. Key 'Name' into L1.
  5. Filter copied range and for ColumnL, select Row Labels and numeric values.
  6. Delete contents of L2:L(last selected cell)
  7. Delete blank rows in copied range with shift cells up (may best via adding a column that counts all 12 months). Hopefully result should be as highlighted in yellow.

Happy to explain further/try again (I've not really tested this) if does not suit.

EDIT (To avoid second block of steps above and facilitate updating for source data changes)

.0. Before first step 2. add a blank row at the very top and move A2:D2 up.
.2. Adjust cell references accordingly (in D3 =IF(AND(A3=A2,C3=C2),D2+1,1).
.3. Create pivot table from A:D

.6. Overwrite Row Labels with Name.
.7. PivotTable Tools, Design, Report Layout, Show in Tabular Form and sort rows and columns A>Z.
.8. Hide Row1, ColumnG and rows and columns that show (blank).

additional example

Steps .0. and .2. in the edit are not required if the pivot table is in a different sheet from the source data (recommended).

Step .3. in the edit is a change to simplify the consequences of expanding the source data set. However introduces (blank) into pivot table that if to be hidden may need adjustment on refresh. So may be better to adjust source data range each time that changes instead: PivotTable Tools, Options, Change Data Source, Change Data Source, Select a table or range). In which case copy rather than move in .0.

Vlookup referring to table data in a different sheet

I have faced similar problem and it was returning #N/A. That means matching data is present but you might having extra space in the M3 column record, that may prevent it from getting exact value. Because you have set last parameter as FALSE, it is looking for "exact match". This formula is correct: =VLOOKUP(M3,Sheet1!$A$2:$Q$47,13,FALSE)

exceeds the list view threshold 5000 items in Sharepoint 2010

You can increase the List View Threshold beyond the 5,000 default, but it is highly recommended that you don't, as it has performance implications. The recommended fix is to add an index to the field or fields used in the query (usually the ID field for a list or the Title field for a library).

When there is an index, that is used to retrieve the item(s); when there is no index the whole list is opened for a scan (and therefore hits the threshold). You create the index on the List (or Library) settings page.

This article is a good overview: http://office.microsoft.com/en-us/sharepoint-foundation-help/manage-lists-and-libraries-with-many-items-HA010377496.aspx

ModuleNotFoundError: What does it mean __main__ is not a package?

If you have created directory and sub-directory, follow the steps below and please keep in mind all directory must have __init__.py to get it recognized as a directory.

  1. In your script, include import sys and sys.path, you will be able to see all the paths available to Python. You must be able to see your current working directory.

  2. Now import sub-directory and respective module that you want to use using: import subdir.subdir.modulename as abc and now you can use the methods in that module.

enter image description here

As an example, you can see in this screenshot I have one parent directory and two sub-directories and under second sub-directories I have the module CommonFunction. On the right my console shows that after execution of sys.path, I can see my working directory.

Do you use NULL or 0 (zero) for pointers in C++?

I'm with Stroustrup on this one :-) Since NULL is not part of the language, I prefer to use 0.

how to set background image in submit button?

You can try the following code:

background-image:url('url of your image') 10px 10px no-repeat

Anaconda-Navigator - Ubuntu16.04

Simply create a new text document called "anaconda-navigator.desktop" in your home directory by the terminal command:

gedit anaconda-navigator.desktop

Then enter the following in your text document:

#!/usr/bin/env xdg-open
[Desktop Entry]
Name=Anaconda
Version=2.0
Type=Application
Exec=/path/to/anaconda-navigator
Icon=/path/to/selected/icon
Comment=Open Anaconda Navigator
Terminal=false

Save the file, then move it to your local applications folder:

mv anaconda-navigator.desktop ~/.local/share/applications/

Once this is done, you will be able to search for "Anaconda" on your applications screen, right click, and add to favorites. This way you don't have to go through the terminal every time!

Finished Product

Rendering HTML in a WebView with custom CSS

Is it possible to have all the content rendered in-page, in a given div? You could then reset the css based on the id, and work on from there.

Say you give your div id="ocon"

In your css, have a definition like:

#ocon *{background:none;padding:0;etc,etc,}

and you can set values to clear all css from applying to the content. After that, you can just use

#ocon ul{}

or whatever, further down the stylesheet, to apply new styles to the content.

How to get visitor's location (i.e. country) using geolocation?

You don't need to locate the user if you only need their country. You can look their IP address up in any IP-to-location service (like maxmind, ipregistry or ip2location). This will be accurate most of the time.

If you really need to get their location, you can get their lat/lng with that method, then query Google's or Yahoo's reverse geocoding service.

Iterator over HashMap in Java

Map<String, Car> carMap = new HashMap<String, Car>(16, (float) 0.75);

// there is no iterator for Maps, but there are methods to do this.

        Set<String> keys = carMap.keySet(); // returns a set containing all the keys
        for(String c : keys)
        {

            System.out.println(c);
        }

        Collection<Car> values = carMap.values(); // returns a Collection with all the objects
        for(Car c : values)
        {
            System.out.println(c.getDiscription());
        }
        /*keySet and the values methods serve as “views” into the Map.
          The elements in the set and collection are merely references to the entries in the map, 
          so any changes made to the elements in the set or collection are reflected in the map, and vice versa.*/

        //////////////////////////////////////////////////////////
        /*The entrySet method returns a Set of Map.Entry objects. 
          Entry is an inner interface in the Map interface.
          Two of the methods specified by Map.Entry are getKey and getValue.
          The getKey method returns the key and getValue returns the value.*/

        Set<Map.Entry<String, Car>> cars = carMap.entrySet(); 
        for(Map.Entry<String, Car> e : cars)
        {
            System.out.println("Keys = " + e.getKey());
            System.out.println("Values = " + e.getValue().getDiscription() + "\n");

        }

How to advance to the next form input when the current input has a value?

In the first question, you don't need an event listener on every input that would be wasteful.

Instead, listen for the enter key and to find the currently focused element use document.activeElement

window.onkeypress = function(e) {
    if (e.which == 13) {
       e.preventDefault();
       var nextInput = inputs.get(inputs.index(document.activeElement) + 1);
       if (nextInput) {
          nextInput.focus();
       }
    }
};

One event listener is better than many, especially on low power / mobile browsers.

Android: Difference between onInterceptTouchEvent and dispatchTouchEvent?

Short answer: dispatchTouchEvent() will be called first of all.

Short advice: should not override dispatchTouchEvent() since it's hard to control, sometimes it can slow down your performance. IMHO, I suggest overriding onInterceptTouchEvent().


Because most answers mention pretty clearly about the flow touch event on activity/ view group/ view, I only add more detail about code on these methods in ViewGroup (ignoring dispatchTouchEvent()):

onInterceptTouchEvent() will be called first, ACTION event will be called respectively down -> move -> up. There are 2 cases:

  1. If you return false in 3 cases (ACTION_DOWN, ACTION_MOVE, ACTION_UP), it will consider as the parent won't need this touch event, so onTouch() of the parents never calls, but onTouch() of the children will call instead; however please notice:

    • The onInterceptTouchEvent() still continue to receive touch event, as long as its children don't call requestDisallowInterceptTouchEvent(true).
    • If there are no children receiving that event (it can happen in 2 cases: no children at the position the users touch, or there are children but it returns false at ACTION_DOWN), the parents will send that event back to onTouch() of the parents.
  2. Vice versa, if you return true, the parent will steal this touch event immediately, and onInterceptTouchEvent() will stop immediately, instead onTouch() of the parents will be called as well as all onTouch() of children will receive the last action event - ACTION_CANCEL (thus, it means the parents stole touch event, and children cannot handle it from then on). The flow of onInterceptTouchEvent() return false is normal, but there is a little confusion with return true case, so I list it here:

    • Return true at ACTION_DOWN, onTouch() of the parents will receive ACTION_DOWN again and following actions (ACTION_MOVE, ACTION_UP).
    • Return true at ACTION_MOVE, onTouch() of the parents will receive next ACTION_MOVE (not the same ACTION_MOVE in onInterceptTouchEvent()) and following actions (ACTION_MOVE, ACTION_UP).
    • Return true at ACTION_UP, onTouch() of the parents will NOT called at all since it's too late for the parents to steal touch event.

One more thing important is ACTION_DOWN of the event in onTouch() will determine if the view would like to receive more action from that event or not. If the view returns true at ACTION_DOWN in onTouch(), it means the view is willing to receive more action from that event. Otherwise, return false at ACTION_DOWN in onTouch() will imply that the view won't receive any more action from that event.

Selection with .loc in python

It's pandas label-based selection, as explained here: https://pandas.pydata.org/pandas-docs/stable/indexing.html#selection-by-label

The boolean array is basically a selection method using a mask.

App.Config file in console application C#

For .NET Core, add System.Configuration.ConfigurationManager from NuGet manager.
And read appSetting from App.config

<appSettings>
  <add key="appSetting1" value="1000" />
</appSettings>

Add System.Configuration.ConfigurationManager from NuGet Manager

enter image description here

ConfigurationManager.AppSettings.Get("appSetting1")

How many socket connections possible?

depends on the application. if there is only a few packages from each client, 100K is very easy for linux. A engineer of my team had done a test years ago, the result shows : when there is no package from client after connection established, linux epoll can watch 400k fd for readablity at cpu usage level under 50%.

Hide particular div onload and then show div after click

$(document).ready(function() {
    $('#div2').hide(0);
    $('#preview').on('click', function() {
        $('#div1').hide(300, function() { // first hide div1
            // then show div2
            $('#div2').show(300);
        });     
    });
});

You missed # before div2

Working Sample

Which data type for latitude and longitude?

In PostGIS, for points with latitude and longitude there is geography datatype.

To add a column:

alter table your_table add column geog geography;

To insert data:

insert into your_table (geog) values ('SRID=4326;POINT(longitude latitude)');

4326 is Spatial Reference ID that says it's data in degrees longitude and latitude, same as in GPS. More about it: http://epsg.io/4326

Order is Longitude, Latitude - so if you plot it as the map, it is (x, y).

To find closest point you need first to create spatial index:

create index on your_table using gist (geog);

and then request, say, 5 closest to a given point:

select * 
from your_table 
order by geog <-> 'SRID=4326;POINT(lon lat)' 
limit 5;

How to force a component's re-rendering in Angular 2?

I force reload my component using *ngIf.

All the components inside my container goes back to the full lifecycle hooks .

In the template :

<ng-container *ngIf="_reload">
    components here 
</ng-container>

Then in the ts file :

public _reload = true;

private reload() {
    setTimeout(() => this._reload = false);
    setTimeout(() => this._reload = true);
}

Process to convert simple Python script into Windows executable

1) Get py2exe from here, according to your Python version.

2) Make a file called "setup.py" in the same folder as the script you want to convert, having the following code:

from distutils.core import setup
import py2exe
setup(console=['myscript.py']) #change 'myscript' to your script

3) Go to command prompt, navigate to that folder, and type:

python setup.py py2exe

4) It will generate a "dist" folder in the same folder as the script. This folder contains the .exe file.

Change SVN repository URL

In my case, the svn relocate command (as well as svn switch --relocate) failed for some reason (maybe the repo was not moved correctly, or something else). I faced this error:

$ svn relocate NEW_SERVER
svn: E195009: The repository at 'NEW_SERVER' has uuid 'e7500204-160a-403c-b4b6-6bc4f25883ea', but the WC has '3a8c444c-5998-40fb-8cb3-409b74712e46'

I did not want to redownload the whole repository, so I found a workaround. It worked in my case, but generally I can imagine a lot of things can get broken (so either backup your working copy, or be ready to re-checkout the whole repo if something goes wrong).

The repo address and its UUID are saved in the .svn/wc.db SQLite database file in your working copy. Just open the database (e.g. in SQLite Browser), browse table REPOSITORY, and change the root and uuid column values to the new ones. You can find the UUID of the new repo by issuing svn info NEW_SERVER.

Again, treat this as a last resort method.

Get data from php array - AJAX - jQuery

quite possibly the simplest method ...

<?php
$change = array('key1' => $var1, 'key2' => $var2, 'key3' => $var3);
echo json_encode(change);
?>

Then the jquery script ...

<script>
$.get("location.php", function(data){
var duce = jQuery.parseJSON(data);
var art1 = duce.key1;
var art2 = duce.key2;
var art3 = duce.key3;
});
</script>

How to add the JDBC mysql driver to an Eclipse project?

You can paste the .jar file of the driver in the Java setup instead of adding it to each project that you create. Paste it in C:\Program Files\Java\jre7\lib\ext or wherever you have installed java.

After this you will find that the .jar driver is enlisted in the library folder of your created project(JRE system library) in the IDE. No need to add it repetitively.

How to increase time in web.config for executing sql query

I realise I'm a litle late to the game, but just spent over a day on trying to change the timeout of a webservice. It seemed to have a default timeout of 30 seconds. I after changing evry other timeout value I could find, including:

  • DB connection string Connect Timeout
  • httpRuntime executionTimeout
  • basicHttpBinding binding closeTimeout
  • basicHttpBinding binding sendTimeout
  • basicHttpBinding binding receiveTimeout
  • basicHttpBinding binding openTimeout

Finaley I found that it was the SqlCommand timeout that was defaulting to 30 seconds.

I decided to just duplicate the timeout of the connection string to the command. The connection string is configured in the web.config.

Some code:

namespace ROS.WebService.Common
{
  using System;
  using System.Configuration;
  using System.Data;
  using System.Data.SqlClient;

  public static class DataAccess
  {
    public static string ConnectionString { get; private set; }

    static DataAccess()
    {
      ConnectionString = ConfigurationManager.ConnectionStrings["ROSdb"].ConnectionString;
    }

    public static int ExecuteNonQuery(string cmdText, CommandType cmdType, params SqlParameter[] sqlParams)
    {
      using (SqlConnection conn = new SqlConnection(DataAccess.ConnectionString))
      {
        using (SqlCommand cmd = new SqlCommand(cmdText, conn) { CommandType = cmdType, CommandTimeout = conn.ConnectionTimeout })
        {
          foreach (var p in sqlParams) cmd.Parameters.Add(p);
          cmd.Connection.Open();
          return cmd.ExecuteNonQuery();
        }
      }
    }
  }
}

Change introduced to "duplicate" the timeout value from the connection string:CommandTimeout = conn.ConnectionTimeout

How do you convert CString and std::string std::wstring to each other?

This works fine:

//Convert CString to std::string
inline std::string to_string(const CString& cst)
{
    return CT2A(cst.GetString());
}

Do I need to pass the full path of a file in another directory to open()?

The examples to os.walk in the documentation show how to do this:

for root, dirs, filenames in os.walk(indir):
    for f in filenames:
        log = open(os.path.join(root, f),'r')

How did you expect the "open" function to know that the string "1" is supposed to mean "/home/des/test/1" (unless "/home/des/test" happens to be your current working directory)?

Apache won't start in wamp

This solved the issue for me:

Right click on the WAMP system try icon -> Tools -> Reinstall all services

Remote debugging a Java application

For JDK 1.3 or earlier :

-Xnoagent -Djava.compiler=NONE -Xdebug -Xrunjdwp:transport=dt_socket,server=y,suspend=n,address=6006

For JDK 1.4

-Xdebug -Xrunjdwp:transport=dt_socket,server=y,suspend=n,address=6006

For newer JDK :

-agentlib:jdwp=transport=dt_socket,server=y,suspend=n,address=6006

Please change the port number based on your needs.

From java technotes

From 5.0 onwards the -agentlib:jdwp option is used to load and specify options to the JDWP agent. For releases prior to 5.0, the -Xdebug and -Xrunjdwp options are used (the 5.0 implementation also supports the -Xdebug and -Xrunjdwp options but the newer -agentlib:jdwp option is preferable as the JDWP agent in 5.0 uses the JVM TI interface to the VM rather than the older JVMDI interface)

One more thing to note, from JVM Tool interface documentation:

JVM TI was introduced at JDK 5.0. JVM TI replaces the Java Virtual Machine Profiler Interface (JVMPI) and the Java Virtual Machine Debug Interface (JVMDI) which, as of JDK 6, are no longer provided.

Angular.js vs Knockout.js vs Backbone.js

It depends on the nature of your application. And, since you did not describe it in great detail, it is an impossible question to answer. I find Backbone to be the easiest, but I work in Angular all day. Performance is more up to the coder than the framework, in my opinion.

Are you doing heavy DOM manipulation? I would use jQuery and Backbone.

Very data driven app? Angular with its nice data binding.

Game programming? None - direct to canvas; maybe a game engine.

How to change the name of a Django app?

In case you are using PyCharm and project stops working after rename:

  1. Edit Run/Debug configuration and change environment variable DJANGO_SETTINGS_MODULE, since it includes your project name.
  2. Go to Settings / Languages & Frameworks / Django and update the settings file location.

Convert JSON string to dict using Python

If you trust the data source, you can use eval to convert your string into a dictionary:

eval(your_json_format_string)

Example:

>>> x = "{'a' : 1, 'b' : True, 'c' : 'C'}"
>>> y = eval(x)

>>> print x
{'a' : 1, 'b' : True, 'c' : 'C'}
>>> print y
{'a': 1, 'c': 'C', 'b': True}

>>> print type(x), type(y)
<type 'str'> <type 'dict'>

>>> print y['a'], type(y['a'])
1 <type 'int'>

>>> print y['a'], type(y['b'])
1 <type 'bool'>

>>> print y['a'], type(y['c'])
1 <type 'str'>

Query based on multiple where clauses in Firebase

ref.orderByChild("lead").startAt("Jack Nicholson").endAt("Jack Nicholson").listner....

This will work.

Display loading image while post with ajax

Let's say you have a tag someplace on the page which contains your loading message:

<div id='loadingmessage' style='display:none'>
  <img src='loadinggraphic.gif'/>
</div>

You can add two lines to your ajax call:

function getData(p){
    var page=p;
    $('#loadingmessage').show();  // show the loading message.
    $.ajax({
        url: "loadData.php?id=<? echo $id; ?>",
        type: "POST",
        cache: false,
        data: "&page="+ page,
        success : function(html){
            $(".content").html(html);
            $('#loadingmessage').hide(); // hide the loading message
        }
    });

AngularJS ng-if with multiple conditions

OR operator:

<div ng-repeat="k in items">
    <div ng-if="k || 'a' or k == 'b'">
        <!-- SOME CONTENT -->
    </div>
</div>

Even though it is simple enough to read, I hope as a developer you are use better names than 'a' 'k' 'b' etc..

For Example:

<div class="links-group" ng-repeat="group in groups" ng-show="!group.hidden">
    <li ng-if="user.groups.admin || group.title == 'Home Pages'"> 
        <!--Content-->
    </li>
</div>

Another OR example

<p ng-if="group.title != 'Dispatcher News' or group.title != 'Coordinator News'" style="padding: 5px;">No links in group.</p>

AND operator (For those stumbling across this stackoverflow answer looking for an AND instead of OR condition)

<div class="links-group" ng-repeat="group in groups" ng-show="!group.hidden">
    <li ng-if="user.groups.admin && group.title == 'Home Pages'"> 
        <!--Content-->
    </li>
</div>