Programs & Examples On #Cssedit

CCSEdit is a program for web design totally focused on editing CSS owned by MacRabbit.

How do I import a Swift file from another Swift file?

In the Documentation it says there are no import statements in Swift.

enter image description here

Simply use:

let primNumber = PrimeNumberModel()

How to upgrade OpenSSL in CentOS 6.5 / Linux / Unix from source?

The only thing you have to do is perform an yum update.

It will automatically download and update a backported version of openssl-1.0.1e-16.el6_5.7 which has been patched by RedHat with heartbeat disabled.

To verify the update simply check the changelog:
# rpm -q --changelog openssl-1.0.1e | grep -B 1 CVE-2014-0160
you should see the following:
* Mon Apr 07 2014 Tomáš Mráz <[email protected]> 1.0.1e-16.7 - fix CVE-2014-0160 - information disclosure in TLS heartbeat extension

Make sure you reboot the server because important services such as Apache and SSH use openSSL.

How to sort an array of objects in Java?

Java 8


Using lambda expressions

Arrays.sort(myTypes, (a,b) -> a.name.compareTo(b.name));

Test.java

public class Test {

    public static void main(String[] args) {

        MyType[] myTypes = {
                new MyType("John", 2, "author1", "publisher1"),
                new MyType("Marry", 298, "author2", "publisher2"),
                new MyType("David", 3, "author3", "publisher3"),
        };

        System.out.println("--- before");
        System.out.println(Arrays.asList(myTypes));
        Arrays.sort(myTypes, (a, b) -> a.name.compareTo(b.name));
        System.out.println("--- after");
        System.out.println(Arrays.asList(myTypes));

    }

}

MyType.java

public class MyType {

    public String name;
    public int id;
    public String author;
    public String publisher;

    public MyType(String name, int id, String author, String publisher) {
        this.name = name;
        this.id = id;
        this.author = author;
        this.publisher = publisher;
    }

    @Override
    public String toString() {
        return "MyType{" +
                "name=" + name + '\'' +
                ", id=" + id +
                ", author='" + author + '\'' +
                ", publisher='" + publisher + '\'' +
                '}' + System.getProperty("line.separator");
    }
}

Output:

--- before
[MyType{name=John', id=2, author='author1', publisher='publisher1'}
, MyType{name=Marry', id=298, author='author2', publisher='publisher2'}
, MyType{name=David', id=3, author='author3', publisher='publisher3'}
]
--- after
[MyType{name=David', id=3, author='author3', publisher='publisher3'}
, MyType{name=John', id=2, author='author1', publisher='publisher1'}
, MyType{name=Marry', id=298, author='author2', publisher='publisher2'}
]

Using method references

Arrays.sort(myTypes, MyType::compareThem);

where compareThem has to be added in MyType.java:

public static int compareThem(MyType a, MyType b) {
    return a.name.compareTo(b.name);
}

When do you use Git rebase instead of Git merge?

It's simple. With rebase you say to use another branch as the new base for your work.

If you have, for example, a branch master, you create a branch to implement a new feature, and say you name it cool-feature, of course the master branch is the base for your new feature.

Now at a certain point you want to add the new feature you implemented in the master branch. You could just switch to master and merge the cool-feature branch:

$ git checkout master
$ git merge cool-feature

But this way a new dummy commit is added. If you want to avoid spaghetti-history you can rebase:

$ git checkout cool-feature
$ git rebase master

And then merge it in master:

$ git checkout master
$ git merge cool-feature

This time, since the topic branch has the same commits of master plus the commits with the new feature, the merge will be just a fast-forward.

Passing variable number of arguments around

Short answer

/// logs all messages below this level, level 0 turns off LOG 
#ifndef LOG_LEVEL
#define LOG_LEVEL 5  // 0:off, 1:error, 2:warning, 3: info, 4: debug, 5:verbose
#endif
#define _LOG_FORMAT_SHORT(letter, format) "[" #letter "]: " format "\n"

/// short log
#define log_s(level, format, ...)     \                                                                                  
    if (level <= LOG_LEVEL)            \                                                                                     
    printf(_LOG_FORMAT_SHORT(level, format), ##__VA_ARGS__)

usage

log_s(1, "fatal error occurred");
log_s(3, "x=%d and name=%s",2, "ali");

output

[1]: fatal error occurred
[3]: x=2 and name=ali

log with file and line number

const char* _getFileName(const char* path)
{
    size_t i = 0;
    size_t pos = 0;
    char* p = (char*)path;
    while (*p) {
        i++;
        if (*p == '/' || *p == '\\') {
            pos = i;
        }
        p++;
    }
    return path + pos;
}

#define _LOG_FORMAT(letter, format)      \                                                                        
    "[" #letter "][%s:%u] %s(): " format "\n", _getFileName(__FILE__), __LINE__, __FUNCTION__

#ifndef LOG_LEVEL
#define LOG_LEVEL 5 // 0:off, 1:error, 2:warning, 3: info, 4: debug, 5:verbose
#endif

/// long log
#define log_l(level, format, ...)     \                                                                               
    if (level <= LOG_LEVEL)            \                                                                                         
    printf(_LOG_FORMAT(level, format), ##__VA_ARGS__)

usage

log_s(1, "fatal error occurred");
log_s(3, "x=%d and name=%s",2, "ali");

output

[1][test.cpp:97] main(): fatal error occurred
[3][test.cpp:98] main(): x=2 and name=ali

custom print function

you can write custom print function and pass ... args to it and it is also possible to combine this with methods above. source from here

int print_custom(const char* format, ...)
{
    static char loc_buf[64];
    char* temp = loc_buf;
    int len;
    va_list arg;
    va_list copy;
    va_start(arg, format);
    va_copy(copy, arg);
    len = vsnprintf(NULL, 0, format, arg);
    va_end(copy);
    if (len >= sizeof(loc_buf)) {
        temp = (char*)malloc(len + 1);
        if (temp == NULL) {
            return 0;
        }
    }
    vsnprintf(temp, len + 1, format, arg);
    printf(temp); // replace with any print function you want
    va_end(arg);
    if (len >= sizeof(loc_buf)) {
        free(temp);
    }
    return len;
}

nodejs vs node on ubuntu 12.04

Late answer, but for up-to-date info...

If you install node.js using the recommend method from the node github installation readme, it suggests following the instructions on the nodesource blog article, rather than installing from the out of date apt-get repo, node.js should run using the node command, as well as the nodejs command, without having to make a new symlink.

This method from article is:

# Note the new setup script name for Node.js v0.12
curl -sL https://deb.nodesource.com/setup_0.12 | sudo bash -

# Then install with:
sudo apt-get install -y nodejs

Note that this is for v0.12, which will get likely become outdated in the not to distant future.

Also, if you're behind a corporate proxy (like me) you'll want to add the -E option to the sudo command, to preserve the env vars required for the proxy:

curl -sL https://deb.nodesource.com/setup_0.12 | sudo -E bash -

Cannot hide status bar in iOS7

I had to do both changes below to hide the status bar:

Add this code to the view controller where you want to hide the status bar:

- (BOOL)prefersStatusBarHidden
{
    return YES;
}

Add this to your .plist file (go to 'info' in your application settings)

View controller-based status bar appearance --- NO

Then you can call this line to hide the status bar:

[[UIApplication sharedApplication] setStatusBarHidden:YES];

How to execute multiple commands in a single line

Googling gives me this:


Command A & Command B

Execute Command A, then execute Command B (no evaluation of anything)


Command A | Command B

Execute Command A, and redirect all its output into the input of Command B


Command A && Command B

Execute Command A, evaluate the errorlevel after running and if the exit code (errorlevel) is 0, only then execute Command B


Command A || Command B

Execute Command A, evaluate the exit code of this command and if it's anything but 0, only then execute Command B


How I can check if an object is null in ruby on rails 2?

You can check if an object is nil (null) by calling present? or blank? .

@object.present?

this will return false if the project is an empty string or nil .

or you can use

@object.blank?

this is the same as present? with a bang and you can use it if you don't like 'unless'. this will return true for an empty string or nil .

Double vs. BigDecimal?

There are two main differences from double:

  • Arbitrary precision, similarly to BigInteger they can contain number of arbitrary precision and size
  • Base 10 instead of Base 2, a BigDecimal is n*10^scale where n is an arbitrary large signed integer and scale can be thought of as the number of digits to move the decimal point left or right

The reason you should use BigDecimal for monetary calculations is not that it can represent any number, but that it can represent all numbers that can be represented in decimal notion and that include virtually all numbers in the monetary world (you never transfer 1/3 $ to someone).

How to set Java classpath in Linux?

export CLASSPATH=/home/appnetix/LOG4J_HOME/log4j-1.2.16.jar

or, if you already have some classpath set

export CLASSPATH=$CLASSPATH:/home/appnetix/LOG4J_HOME/log4j-1.2.16.jar

and, if also you want to include current directory

export CLASSPATH=$CLASSPATH:/home/appnetix/LOG4J_HOME/log4j-1.2.16.jar:.

Hide/Show Action Bar Option Menu Item for different fragments

This is one way of doing this:

add a "group" to your menu:

<?xml version="1.0" encoding="utf-8"?>
<menu xmlns:android="http://schemas.android.com/apk/res/android" >

    <group
        android:id="@+id/main_menu_group">
         <item android:id="@+id/done_item"
              android:title="..."
              android:icon="..."
              android:showAsAction="..."/>
    </group>
</menu>

then, add a

Menu menu;

variable to your activity and set it in your override of onCreateOptionsMenu:

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    this.menu = menu;
    // inflate your menu here
}

After, add and use this function to your activity when you'd like to show/hide the menu:

public void showOverflowMenu(boolean showMenu){
    if(menu == null)
        return;
    menu.setGroupVisible(R.id.main_menu_group, showMenu);
}

I am not saying this is the best/only way, but it works well for me.

How to clear the JTextField by clicking JButton

Looking for EventHandling, ActionListener?

or code?

JButton b = new JButton("Clear");
b.addActionListener(new ActionListener(){
    public void actionPerformed(ActionEvent e){
        textfield.setText("");
        //textfield.setText(null); //or use this
    }
});

Also See
How to Use Buttons

Python UTC datetime object's ISO format doesn't include Z (Zulu or Zero offset)

By combining all answers above I came with following function :

from datetime import datetime, tzinfo, timedelta
class simple_utc(tzinfo):
    def tzname(self,**kwargs):
        return "UTC"
    def utcoffset(self, dt):
        return timedelta(0)


def getdata(yy, mm, dd, h, m, s) :
    d = datetime(yy, mm, dd, h, m, s)
    d = d.replace(tzinfo=simple_utc()).isoformat()
    d = str(d).replace('+00:00', 'Z')
    return d


print getdata(2018, 02, 03, 15, 0, 14)

CFLAGS vs CPPFLAGS

The CPPFLAGS macro is the one to use to specify #include directories.

Both CPPFLAGS and CFLAGS work in your case because the make(1) rule combines both preprocessing and compiling in one command (so both macros are used in the command).

You don't need to specify . as an include-directory if you use the form #include "...". You also don't need to specify the standard compiler include directory. You do need to specify all other include-directories.

How to POST form data with Spring RestTemplate?

How to POST mixed data: File, String[], String in one request.

You can use only what you need.

private String doPOST(File file, String[] array, String name) {
    RestTemplate restTemplate = new RestTemplate(true);

    //add file
    LinkedMultiValueMap<String, Object> params = new LinkedMultiValueMap<>();
    params.add("file", new FileSystemResource(file));

    //add array
    UriComponentsBuilder builder = UriComponentsBuilder.fromHttpUrl("https://my_url");
    for (String item : array) {
        builder.queryParam("array", item);
    }

    //add some String
    builder.queryParam("name", name);

    //another staff
    String result = "";
    HttpHeaders headers = new HttpHeaders();
    headers.setContentType(MediaType.MULTIPART_FORM_DATA);

    HttpEntity<LinkedMultiValueMap<String, Object>> requestEntity =
            new HttpEntity<>(params, headers);

    ResponseEntity<String> responseEntity = restTemplate.exchange(
            builder.build().encode().toUri(),
            HttpMethod.POST,
            requestEntity,
            String.class);

    HttpStatus statusCode = responseEntity.getStatusCode();
    if (statusCode == HttpStatus.ACCEPTED) {
        result = responseEntity.getBody();
    }
    return result;
}

The POST request will have File in its Body and next structure:

POST https://my_url?array=your_value1&array=your_value2&name=bob 

PHP Email sending BCC

You have $headers .= '...'; followed by $headers = '...';; the second line is overwriting the first.

Just put the $headers .= "Bcc: $emailList\r\n"; say after the Content-type line and it should be fine.

On a side note, the To is generally required; mail servers might mark your message as spam otherwise.

$headers  = "From: [email protected]\r\n" .
  "X-Mailer: php\r\n";
$headers .= "MIME-Version: 1.0\r\n";
$headers .= "Content-Type: text/html; charset=ISO-8859-1\r\n";
$headers .= "Bcc: $emailList\r\n";

Start new Activity and finish current one in Android?

You can use finish() method or you can use:

android:noHistory="true"

And then there is no need to call finish() anymore.

<activity android:name=".ClassName" android:noHistory="true" ... />

How to change the bootstrap primary color?

I've created this tool: https://lingtalfi.com/bootstrap4-color-generator, you simply put primary in the first field, then choose your color, and click generate.

Then copy the generated scss or css code, and paste it in a file named my-colors.scss or my-colors.css (or whatever name you want).

Once you compile the scss into css, you can include that css file AFTER the bootstrap CSS and you'll be good to go.

The whole process takes about 10 seconds if you get the gist of it, provided that the my-colors.scss file is already created and included in your head tag.

Note: this tool can be used to override bootstrap's default colors (primary, secondary, danger, ...), but you can also create custom colors if you want (blue, green, ternary, ...).

Note2: this tool was made to work with bootstrap 4 (i.e. not any subsequent version for now).

Get startup type of Windows service using PowerShell

If you update to PowerShell 5 you can query all of the services on the machine and display Name and StartType and sort it by StartType for easy viewing:

Get-Service |Select-Object -Property Name,StartType |Sort-Object -Property StartType

Xcode 5 and iOS 7: Architecture and Valid architectures

You do not need to limit your compiler to only armv7 and armv7s by removing arm64 setting from supported architectures. You just need to set Deployment target setting to 5.1.1

Important note: you cannot set Deployment target to 5.1.1 in Build Settings section because it is drop-down only with fixed values. But you can easily set it to 5.1.1 in General section of application settings by just typing the value in text field.

Absolute and Flexbox in React Native

The first step would be to add

position: 'absolute',

then if you want the element full width, add

left: 0,
right: 0,

then, if you want to put the element in the bottom, add

bottom: 0,
// don't need set top: 0

if you want to position the element at the top, replace bottom: 0 by top: 0

TypeError: Missing 1 required positional argument: 'self'

You need to initialize it first:

p = Pump().getPumps()

Error You must specify a region when running command aws ecs list-container-instances

Just to add to answers by Mr. Dimitrov and Jason, if you are using a specific profile and you have put your region setting there,then for all the requests you need to add

"--profile" option.

For example:

Lets say you have AWS Playground profile, and the ~/.aws/config has [profile playground] which further has something like,

[profile playground] region=us-east-1

then, use something like below

aws ecs list-container-instances --cluster default --profile playground

String comparison in Python: is vs. ==

The logic is not flawed. The statement

if x is y then x==y is also True

should never be read to mean

if x==y then x is y

It is a logical error on the part of the reader to assume that the converse of a logic statement is true. See http://en.wikipedia.org/wiki/Converse_(logic)

How to darken a background using CSS?

Use an :after psuedo-element:

.overlay {
    position: relative;
    transition: all 1s;
}

.overlay:after {
    content: '\A';
    position: absolute;
    width: 100%; 
    height:100%;
    top:0; 
    left:0;
    background:rgba(0,0,0,0.5);
    opacity: 1;
    transition: all 0.5s;
    -webkit-transition: all 0.5s;
    -moz-transition: all 0.5s;
}
.overlay:hover:after {
    opacity: 0;
}

Check out my pen >

http://codepen.io/craigocurtis/pen/KzXYad

How to call a javaScript Function in jsp on page load without using <body onload="disableView()">

Either use window.onload this way

<script>
    window.onload = function() {
        // ...
    }
</script>

or alternatively

<script>
    window.onload = functionName;
</script>

(yes, without the parentheses)


Or just put the script at the very bottom of page, right before </body>. At that point, all HTML DOM elements are ready to be accessed by document functions.

<body>
    ...

    <script>
        functionName();
    </script>
</body>

add scroll bar to table body

you can wrap the content of the <tbody> in a scrollable <div> :

html

....
<tbody>
  <tr>
    <td colspan="2">
      <div class="scrollit">
        <table>
          <tr>
            <td>January</td>
            <td>$100</td>
          </tr>
          <tr>
            <td>February</td>
            <td>$80</td>
          </tr>
          <tr>
            <td>January</td>
            <td>$100</td>
          </tr>
          <tr>
            <td>February</td>
            <td>$80</td>
          </tr>
          ...

css

.scrollit {
    overflow:scroll;
    height:100px;
}

see my jsfiddle, forked from yours: http://jsfiddle.net/VTNax/2/

git still shows files as modified after adding to .gitignore

if you have .idea/* already added in your .gitignore and if git rm -r --cached .idea/ command does not work (note: shows error-> fatal: pathspec '.idea/' did not match any files) try this

remove .idea file from your app run this command

rm -rf .idea

run git status now and check while running the app .idea folder will be created again but it will not be tracked

Lowercase and Uppercase with jQuery

I think you want to lowercase the checked value? Try:

var jIsHasKids = $('#chkIsHasKids:checked').val().toLowerCase();

or you want to check it, then get its value as lowercase:

var jIsHasKids = $('#chkIsHasKids').attr("checked", true).val().toLowerCase();

Sleep function Visual Basic

This one is much easie.

Threading.Thread.Sleep(3000)

How to obtain Signing certificate fingerprint (SHA1) for OAuth 2.0 on Android?

  1. Open your command prompt
  2. Navigate working directory to 1.8.0/bin
  3. paste keytool -list -v -alias androiddebugkey -keystore %USERPROFILE%\.android\debug.keystore
  4. Press enter if it ask you a password

How do I get the width and height of a HTML5 canvas?

It might be worth looking at a tutorial: MDN Canvas Tutorial

You can get the width and height of a canvas element simply by accessing those properties of the element. For example:

var canvas = document.getElementById('mycanvas');
var width = canvas.width;
var height = canvas.height;

If the width and height attributes are not present in the canvas element, the default 300x150 size will be returned. To dynamically get the correct width and height use the following code:

const canvasW = canvas.getBoundingClientRect().width;
const canvasH = canvas.getBoundingClientRect().height;

Or using the shorter object destructuring syntax:

const { width, height } = canvas.getBoundingClientRect();

The context is an object you get from the canvas to allow you to draw into it. You can think of the context as the API to the canvas, that provides you with the commands that enable you to draw on the canvas element.

Python - A keyboard command to stop infinite loop?

Ctrl+C is what you need. If it didn't work, hit it harder. :-) Of course, you can also just close the shell window.

Edit: You didn't mention the circumstances. As a last resort, you could write a batch file that contains taskkill /im python.exe, and put it on your desktop, Start menu, etc. and run it when you need to kill a runaway script. Of course, it will kill all Python processes, so be careful.

Press Keyboard keys using a batch file

Just to be clear, you are wanting to launch a program from a batch file and then have the batch file press keys (in your example, the arrow keys) within that launched program?

If that is the case, you aren't going to be able to do that with simply a ".bat" file as the launched would stop the batch file from continuing until it terminated--

My first recommendation would be to use something like AutoHotkey or AutoIt if possible, simply because they both have active forums where you'd find countless examples of people launching applications and sending key presses not to mention tools to simply "record" what you want to do. However you said this is a work computer and you may not be able to load a 3rd party program.. but you aren't without options.

You can use Windows Scripting Host from something like a .vbs file to launch a program and send keys to that process. If you're running a version of Windows that includes PowerShell 2.0 (Windows XP with Service Pack 3, Windows Vista with Service Pack 1, Windows 7, etc.) you can use Windows Scripting Host as a COM object from your PS script or use VB's Intereact class.

The specifics of how to do it are outside the scope of this answer but you can find numerous examples using the methods I just described by searching on SO or Google.

edit: Just to help you get started you can look here:

  1. Automate tasks with Windows Script Host's SendKeys method
  2. A useful thread about SendKeys

Page loaded over HTTPS but requested an insecure XMLHttpRequest endpoint

Try to add a s after http

Like this:

http://integration.jsite.com/data/vis => https://integration.jsite.com/data/vis

It works for me

SELECT * WHERE NOT EXISTS

SELECT * from employees
WHERE NOT EXISTS (SELECT name FROM eotm_dyn)

Never returns any records unless eotm_dyn is empty. You need to some kind of criteria on SELECT name FROM eotm_dyn like

SELECT * from employees
WHERE NOT EXISTS (
    SELECT name FROM eotm_dyn WHERE eotm_dyn.employeeid = employees.employeeid
)

assuming that the two tables are linked by a foreign key relationship. At this point you could use a variety of other options including a LEFT JOIN. The optimizer will typically handle them the same in most cases, however.

CSS3 100vh not constant in mobile browser

Here's a work around I used for my React app.

iPhone 11 Pro & iPhone Pro Max - 120px

iPhone 8 - 80px

max-height: calc(100vh - 120px);

It's a compromise but relatively simple fix

Any shortcut to initialize all array elements to zero?

Yet another approach by using lambda above java 8

 Arrays.stream(new Integer[nodelist.size()]).map(e -> 
 Integer.MAX_VALUE).toArray(Integer[]::new);

How to break a while loop from an if condition inside the while loop?

while(something.hasnext())
do something...
   if(contains something to process){
      do something...
      break;
   }
}

Just use the break statement;

For eg:this just prints "Breaking..."

while (true) {
     if (true) {
         System.out.println("Breaking...");
         break;
     }
     System.out.println("Did this print?");
}

Regular expression to return text between parenthesis

import re

fancy = u'abcde(date=\'2/xc2/xb2\',time=\'/case/test.png\')'

print re.compile( "\((.*)\)" ).search( fancy ).group( 1 )

MySQL Data - Best way to implement paging?

There's literature about it:

The main problem happens with the usage of large OFFSETs. They avoid using OFFSET with a variety of techniques, ranging from id range selections in the WHERE clause, to some kind of caching or pre-computing pages.

There are suggested solutions at Use the INDEX, Luke:

HTML-5 date field shows as "mm/dd/yyyy" in Chrome, even when valid date is set

In chrome to set the value you need to do YYYY-MM-DD i guess because this worked : http://jsfiddle.net/HudMe/6/

So to make it work you need to set the date as 2012-10-01

Controller 'ngModel', required by directive '...', can't be found

You can also remove the line

  require: 'ngModel',

if you don't need ngModel in this directive. Removing ngModel will allow you to make a directive without thatngModel error.

Sorted array list in Java

I think the choice between SortedSets/Lists and 'normal' sortable collections depends, whether you need sorting only for presentation purposes or at almost every point during runtime. Using a sorted collection may be much more expensive because the sorting is done everytime you insert an element.

If you can't opt for a collection in the JDK, you can take a look at the Apache Commons Collections

How to get current foreground activity context in android?

I expand on the top of @gezdy's answer.

In every Activities, instead of having to "register" itself with Application with manual coding, we can make use of the following API since level 14, to help us achieve similar purpose with less manual coding.

public void registerActivityLifecycleCallbacks (Application.ActivityLifecycleCallbacks callback)

http://developer.android.com/reference/android/app/Application.html#registerActivityLifecycleCallbacks%28android.app.Application.ActivityLifecycleCallbacks%29

In Application.ActivityLifecycleCallbacks, you can get which Activity is "attached" to or "detached" to this Application.

However, this technique is only available since API level 14.

Closure in Java 7

Please see this wiki page for definition of closure.

And this page for closure in Java 8: http://mail.openjdk.java.net/pipermail/lambda-dev/2011-September/003936.html

Also look at this Q&A: Closures in Java 7

Align div right in Bootstrap 3

The class pull-right is still there in Bootstrap 3 See the 'helper classes' here

pull-right is defined by

.pull-right {
  float: right !important;
}

without more info on styles and content, it's difficult to say.

It definitely pulls right in this JSBIN when the page is wider than 990px - which is when the col-md styling kicks in, Bootstrap 3 being mobile first and all.

Bootstrap 4

Note that for Bootstrap 4 .pull-right has been replaced with .float-right https://www.geeksforgeeks.org/pull-left-and-pull-right-classes-in-bootstrap-4/#:~:text=pull%2Dright%20classes%20have%20been,based%20on%20the%20Bootstrap%20Grid.

Select distinct using linq

myList.GroupBy(test => test.id)
      .Select(grp => grp.First());

Edit: as getting this IEnumerable<> into a List<> seems to be a mystery to many people, you can simply write:

var result = myList.GroupBy(test => test.id)
                   .Select(grp => grp.First())
                   .ToList();

But one is often better off working with the IEnumerable rather than IList as the Linq above is lazily evaluated: it doesn't actually do all of the work until the enumerable is iterated. When you call ToList it actually walks the entire enumerable forcing all of the work to be done up front. (And may take a little while if your enumerable is infinitely long.)

The flipside to this advice is that each time you enumerate such an IEnumerable the work to evaluate it has to be done afresh. So you need to decide for each case whether it is better to work with the lazily evaluated IEnumerable or to realize it into a List, Set, Dictionary or whatnot.

In git, what is the difference between merge --squash and rebase?

Merge squash merges a tree (a sequence of commits) into a single commit. That is, it squashes all changes made in n commits into a single commit.

Rebasing is re-basing, that is, choosing a new base (parent commit) for a tree. Maybe the mercurial term for this is more clear: they call it transplant because it's just that: picking a new ground (parent commit, root) for a tree.

When doing an interactive rebase, you're given the option to either squash, pick, edit or skip the commits you are going to rebase.

Hope that was clear!

Printing object properties in Powershell

Try this:

Write-Host ($obj | Format-Table | Out-String)

or

Write-Host ($obj | Format-List | Out-String)

What is the Python equivalent for a case/switch statement?

While the official docs are happy not to provide switch, I have seen a solution using dictionaries.

For example:

# define the function blocks
def zero():
    print "You typed zero.\n"

def sqr():
    print "n is a perfect square\n"

def even():
    print "n is an even number\n"

def prime():
    print "n is a prime number\n"

# map the inputs to the function blocks
options = {0 : zero,
           1 : sqr,
           4 : sqr,
           9 : sqr,
           2 : even,
           3 : prime,
           5 : prime,
           7 : prime,
}

Then the equivalent switch block is invoked:

options[num]()

This begins to fall apart if you heavily depend on fall through.

How do I export a project in the Android studio?

From the menu:

Build|Generate Signed APK

or

Build|Build APK

(the latter if you don't need a signed one to publish to the Play Store)

What is reflection and why is it useful?

Reflection allows instantiation of new objects, invocation of methods, and get/set operations on class variables dynamically at run time without having prior knowledge of its implementation.

Class myObjectClass = MyObject.class;
Method[] method = myObjectClass.getMethods();

//Here the method takes a string parameter if there is no param, put null.
Method method = aClass.getMethod("method_name", String.class); 

Object returnValue = method.invoke(null, "parameter-value1");

In above example the null parameter is the object you want to invoke the method on. If the method is static you supply null. If the method is not static, then while invoking you need to supply a valid MyObject instance instead of null.

Reflection also allows you to access private member/methods of a class:

public class A{

  private String str= null;

  public A(String str) {
  this.str= str;
  }
}

.

A obj= new A("Some value");

Field privateStringField = A.class.getDeclaredField("privateString");

//Turn off access check for this field
privateStringField.setAccessible(true);

String fieldValue = (String) privateStringField.get(obj);
System.out.println("fieldValue = " + fieldValue);
  • For inspection of classes (also know as introspection) you don't need to import the reflection package (java.lang.reflect). Class metadata can be accessed through java.lang.Class.

Reflection is a very powerful API but it may slow down the application if used in excess, as it resolves all the types at runtime.

How to pass table value parameters to stored procedure from .net code

The cleanest way to work with it. Assuming your table is a list of integers called "dbo.tvp_Int" (Customize for your own table type)

Create this extension method...

public static void AddWithValue_Tvp_Int(this SqlParameterCollection paramCollection, string parameterName, List<int> data)
{
   if(paramCollection != null)
   {
       var p = paramCollection.Add(parameterName, SqlDbType.Structured);
       p.TypeName = "dbo.tvp_Int";
       DataTable _dt = new DataTable() {Columns = {"Value"}};
       data.ForEach(value => _dt.Rows.Add(value));
       p.Value = _dt;
   }
}

Now you can add a table valued parameter in one line anywhere simply by doing this:

cmd.Parameters.AddWithValueFor_Tvp_Int("@IDValues", listOfIds);

Create a GUID in Java

java.util.UUID.randomUUID();

How to remove old and unused Docker images

If you build these pruned images yourself (from some other, older base images) please be careful with the accepted solutions above based on docker image prune, as the command is blunt and will try to remove also all dependencies required by your latest images (the command should be probably renamed to docker image*s* prune).

The solution I came up for my docker image build pipelines (where there are daily builds and tags=dates are in the YYYYMMDD format) is this:

# carefully narrow down the image to be deleted (to avoid removing useful static stuff like base images)
my_deleted_image=mirekphd/ml-cpu-py37-vsc-cust

# define the monitored image (tested for obsolescence), which will be usually the same as deleted one, unless deleting some very infrequently built image which requires a separate "clock"
monitored_image=mirekphd/ml-cache

# calculate the oldest acceptable tag (date)
date_week_ago=$(date -d "last week" '+%Y%m%d')

# get the IDs of obsolete tags of our deleted image
# note we use monitored_image to test for obsolescence
my_deleted_image_obsolete_tag_ids=$(docker images --filter="before=$monitored_image:$date_week_ago" | grep $my_deleted_image | awk '{print $3}')

# remove the obsolete tags of the deleted image
# (note it typically has to be forced using -f switch)
docker rmi -f $my_deleted_image_obsolete_tag_ids

Is there anything like .NET's NotImplementedException in Java?

You could do it yourself (thats what I did) - in order to not be bothered with exception handling, you simply extend the RuntimeException, your class could look something like this:

public class NotImplementedException extends RuntimeException {

    private static final long serialVersionUID = 1L;

    public NotImplementedException(){}
}

You could extend it to take a message - but if you use the method as I do (that is, as a reminder, that there is still something to be implemented), then usually there is no need for additional messages.

I dare say, that I only use this method, while I am in the process of developing a system, makes it easier for me to not lose track of which methods are still not implemented properly :)

Single Result from Database by using mySQLi

If you assume just one result you could do this as in Edwin suggested by using specific users id.

$someUserId = 'abc123';

$stmt = $mysqli->prepare("SELECT ssfullname, ssemail FROM userss WHERE user_id = ?");
$stmt->bind_param('s', $someUserId);

$stmt->execute();

$stmt->bind_result($ssfullname, $ssemail);
$stmt->store_result();
$stmt->fetch();

ChromePhp::log($ssfullname, $ssemail); //log result in chrome if ChromePhp is used.

OR as "Your Common Sense" which selects just one user.

$stmt = $mysqli->prepare("SELECT ssfullname, ssemail FROM userss ORDER BY ssid LIMIT 1");

$stmt->execute();
$stmt->bind_result($ssfullname, $ssemail);
$stmt->store_result();
$stmt->fetch();

Nothing really different from the above except for PHP v.5

How to detect simple geometric shapes using OpenCV

The answer depends on the presence of other shapes, level of noise if any and invariance you want to provide for (e.g. rotation, scaling, etc). These requirements will define not only the algorithm but also required pre-procesing stages to extract features.

Template matching that was suggested above works well when shapes aren't rotated or scaled and when there are no similar shapes around; in other words, it finds a best translation in the image where template is located:

double minVal, maxVal;
Point minLoc, maxLoc;
Mat image, template, result; // template is your shape
matchTemplate(image, template, result, CV_TM_CCOEFF_NORMED);
minMaxLoc(result, &minVal, &maxVal, &minLoc, &maxLoc); // maxLoc is answer

Geometric hashing is a good method to get invariance in terms of rotation and scaling; this method would require extraction of some contour points.

Generalized Hough transform can take care of invariance, noise and would have minimal pre-processing but it is a bit harder to implement than other methods. OpenCV has such transforms for lines and circles.

In the case when number of shapes is limited calculating moments or counting convex hull vertices may be the easiest solution: openCV structural analysis

AngularJS performs an OPTIONS HTTP request for a cross-origin resource

This fixed my problem:

$http.defaults.headers.post["Content-Type"] = "text/plain";

How to check if a string contains only digits in Java

According to Oracle's Java Documentation:

private static final Pattern NUMBER_PATTERN = Pattern.compile(
        "[\\x00-\\x20]*[+-]?(NaN|Infinity|((((\\p{Digit}+)(\\.)?((\\p{Digit}+)?)" +
        "([eE][+-]?(\\p{Digit}+))?)|(\\.((\\p{Digit}+))([eE][+-]?(\\p{Digit}+))?)|" +
        "(((0[xX](\\p{XDigit}+)(\\.)?)|(0[xX](\\p{XDigit}+)?(\\.)(\\p{XDigit}+)))" +
        "[pP][+-]?(\\p{Digit}+)))[fFdD]?))[\\x00-\\x20]*");
boolean isNumber(String s){
return NUMBER_PATTERN.matcher(s).matches()
}

How can I view the Git history in Visual Studio Code?

Git Graph seems like a decent extension. After installing, you can open the graph view from the bottom status bar.

How to change indentation mode in Atom?

If you're using Babel you may also want to make sure to update your "Language Babel" package. For me, even though I had the Tab Length set to 2 in my core editor settings, the Same setting in the Language Babel config was overriding it with 4.

Atom -> Preferences -> Packages -> (Search for Babel) -> Grammar -> Tab Length

Make sure the appropriate Grammar, There's "Babel ES6 Javascript Grammar", "language-babel-extension Grammar" as well as "Regular Expression". You probably want to update all of them to be consistent.

How do operator.itemgetter() and sort() work?

Looks like you're a little bit confused about all that stuff.

operator is a built-in module providing a set of convenient operators. In two words operator.itemgetter(n) constructs a callable that assumes an iterable object (e.g. list, tuple, set) as input, and fetches the n-th element out of it.

So, you can't use key=a[x][1] there, because python has no idea what x is. Instead, you could use a lambda function (elem is just a variable name, no magic there):

a.sort(key=lambda elem: elem[1])

Or just an ordinary function:

def get_second_elem(iterable):
    return iterable[1]

a.sort(key=get_second_elem)

So, here's an important note: in python functions are first-class citizens, so you can pass them to other functions as a parameter.

Other questions:

  1. Yes, you can reverse sort, just add reverse=True: a.sort(key=..., reverse=True)
  2. To sort by more than one column you can use itemgetter with multiple indices: operator.itemgetter(1,2), or with lambda: lambda elem: (elem[1], elem[2]). This way, iterables are constructed on the fly for each item in list, which are than compared against each other in lexicographic(?) order (first elements compared, if equal - second elements compared, etc)
  3. You can fetch value at [3,2] using a[2,1] (indices are zero-based). Using operator... It's possible, but not as clean as just indexing.

Refer to the documentation for details:

  1. operator.itemgetter explained
  2. Sorting list by custom key in Python

Javascript equivalent of php's strtotime()?

Check out this implementation of PHP's strtotime() in JavaScript!

I found that it works identically to PHP for everything that I threw at it.

Update: this function as per version 1.0.2 can't handle this case: '2007:07:20 20:52:45' (Note the : separator for year and month)

Update 2018:

This is now available as an npm module! Simply npm install locutus and then in your source:

var strtotime = require('locutus/php/datetime/strtotime');

Set up Python simpleHTTPserver on Windows

From Stack Overflow question What is the Python 3 equivalent of "python -m SimpleHTTPServer":

The following works for me:

python -m http.server [<portNo>]

Because I am using Python 3 the module SimpleHTTPServer has been replaced by http.server, at least in Windows.

Pythonic way to return list of every nth item in a larger list

existing_list = range(0, 1001)
filtered_list = [i for i in existing_list if i % 10 == 0]

How can I get the source code of a Python function?

While I'd generally agree that inspect is a good answer, I'd disagree that you can't get the source code of objects defined in the interpreter. If you use dill.source.getsource from dill, you can get the source of functions and lambdas, even if they are defined interactively. It also can get the code for from bound or unbound class methods and functions defined in curries... however, you might not be able to compile that code without the enclosing object's code.

>>> from dill.source import getsource
>>> 
>>> def add(x,y):
...   return x+y
... 
>>> squared = lambda x:x**2
>>> 
>>> print getsource(add)
def add(x,y):
  return x+y

>>> print getsource(squared)
squared = lambda x:x**2

>>> 
>>> class Foo(object):
...   def bar(self, x):
...     return x*x+x
... 
>>> f = Foo()
>>> 
>>> print getsource(f.bar)
def bar(self, x):
    return x*x+x

>>> 

How to find locked rows in Oracle

The below PL/SQL block finds all locked rows in a table. The other answers only find the blocking session, finding the actual locked rows requires reading and testing each row.

(However, you probably do not need to run this code. If you're having a locking problem, it's usually easier to find the culprit using GV$SESSION.BLOCKING_SESSION and other related data dictionary views. Please try another approach before you run this abysmally slow code.)

First, let's create a sample table and some data. Run this in session #1.

--Sample schema.
create table test_locking(a number);
insert into test_locking values(1);
insert into test_locking values(2);
commit;
update test_locking set a = a+1 where a = 1;

In session #2, create a table to hold the locked ROWIDs.

--Create table to hold locked ROWIDs.
create table locked_rowids(the_rowid rowid);
--Remove old rows if table is already created:
--delete from locked_rowids;
--commit;

In session #2, run this PL/SQL block to read the entire table, probe each row, and store the locked ROWIDs. Be warned, this may be ridiculously slow. In your real version of this query, change both references to TEST_LOCKING to your own table.

--Save all locked ROWIDs from a table.
--WARNING: This PL/SQL block will be slow and will temporarily lock rows.
--You probably don't need this information - it's usually good enough to know
--what other sessions are locking a statement, which you can find in
--GV$SESSION.BLOCKING_SESSION.
declare
    v_resource_busy exception;
    pragma exception_init(v_resource_busy, -00054);
    v_throwaway number;
    type rowid_nt is table of rowid;
    v_rowids rowid_nt := rowid_nt();
begin
    --Loop through all the rows in the table.
    for all_rows in
    (
        select rowid
        from test_locking
    ) loop
        --Try to look each row.
        begin
            select 1
            into v_throwaway
            from test_locking
            where rowid = all_rows.rowid
            for update nowait;
        --If it doesn't lock, then record the ROWID.
        exception when v_resource_busy then
            v_rowids.extend;
            v_rowids(v_rowids.count) := all_rows.rowid;
        end;

        rollback;
    end loop;

    --Display count:
    dbms_output.put_line('Rows locked: '||v_rowids.count);

    --Save all the ROWIDs.
    --(Row-by-row because ROWID type is weird and doesn't work in types.)
    for i in 1 .. v_rowids.count loop
        insert into locked_rowids values(v_rowids(i));
    end loop;
    commit;
end;
/

Finally, we can view the locked rows by joining to the LOCKED_ROWIDS table.

--Display locked rows.
select *
from test_locking
where rowid in (select the_rowid from locked_rowids);


A
-
1

How to store a datetime in MySQL with timezone info

None of the answers here quite hit the nail on the head.

How to store a datetime in MySQL with timezone info

Use two columns: DATETIME, and a VARCHAR to hold the time zone information, which may be in several forms:

A timezone or location such as America/New_York is the highest data fidelity.

A timezone abbreviation such as PST is the next highest fidelity.

A time offset such as -2:00 is the smallest amount of data in this regard.

Some key points:

  • Avoid TIMESTAMP because it's limited to the year 2038, and MySQL relates it to the server timezone, which is probably undesired.
  • A time offset should not be stored naively in an INT field, because there are half-hour and quarter-hour offsets.

If it's important for your use case to have MySQL compare or sort these dates chronologically, DATETIME has a problem:

'2009-11-10 11:00:00 -0500' is before '2009-11-10 10:00:00 -0700' in terms of "instant in time", but they would sort the other way when inserted into a DATETIME.

You can do your own conversion to UTC. In the above example, you would then have
'2009-11-10 16:00:00' and '2009-11-10 17:00:00' respectively, which would sort correctly. When retrieving the data, you would then use the timezone info to revert it to its original form.

One recommendation which I quite like is to have three columns:

  • local_time DATETIME
  • utc_time DATETIME
  • time_zone VARCHAR(X) where X is appropriate for what kind of data you're storing there. (I would choose 64 characters for timezone/location.)

An advantage to the 3-column approach is that it's explicit: with a single DATETIME column, you can't tell at a glance if it's been converted to UTC before insertion.


Regarding the descent of accuracy through timezone/abbreviation/offset:

  • If you have the user's timezone/location such as America/Juneau, you can know accurately what the wall clock time is for them at any point in the past or future (barring changes to the way Daylight Savings is handled in that location). The start/end points of DST, and whether it's used at all, are dependent upon location, so this is the only reliable way.
  • If you have a timezone abbreviation such as MST, (Mountain Standard Time) or a plain offset such as -0700, you will be unable to predict a wall clock time in the past or future. For example, in the United States, Colorado and Arizona both use MST, but Arizona doesn't observe DST. So if the user uploads his cat photo at 14:00 -0700 during the winter months, was he in Arizona or California? If you added six months exactly to that date, would it be 14:00 or 13:00 for the user?

These things are important to consider when your application has time, dates, or scheduling as core function.


References:

mvn command is not recognized as an internal or external command

Are you trying to reference a user variable in system variables? Try echo %path% and the M2 should have been fully expanded to show the file path to your Maven directory. If it hasn't, then that's the problem.

To fix it, you should create a user variable called PATH and add your %M2% reference into there.

How to do joins in LINQ on multiple fields in single join

you could do something like (below)

var query = from p in context.T1

        join q in context.T2

        on

        new { p.Col1, p.Col2 }

        equals

         new { q.Col1, q.Col2 }

        select new {p...., q......};

Where is shared_ptr?

for VS2008 with feature pack update, shared_ptr can be found under namespace std::tr1.

std::tr1::shared_ptr<int> MyIntSmartPtr = new int;

of

if you had boost installation path (for example @ C:\Program Files\Boost\boost_1_40_0) added to your IDE settings:

#include <boost/shared_ptr.hpp>

How to replace text in a column of a Pandas dataframe?

For anyone else arriving here from Google search on how to do a string replacement on all columns (for example, if one has multiple columns like the OP's 'range' column): Pandas has a built in replace method available on a dataframe object.

df.replace(',', '-', regex=True)

Source: Docs

'Connect-MsolService' is not recognized as the name of a cmdlet

Following worked for me:

  1. Uninstall the previously installed ‘Microsoft Online Service Sign-in Assistant’ and ‘Windows Azure Active Directory Module for Windows PowerShell’.
  2. Install 64-bit versions of ‘Microsoft Online Service Sign-in Assistant’ and ‘Windows Azure Active Directory Module for Windows PowerShell’. https://littletalk.wordpress.com/2013/09/23/install-and-configure-the-office-365-powershell-cmdlets/

If you get the following error In order to install Windows Azure Active Directory Module for Windows PowerShell, you must have Microsoft Online Services Sign-In Assistant version 7.0 or greater installed on this computer, then install the Microsoft Online Services Sign-In Assistant for IT Professionals BETA: http://www.microsoft.com/en-us/download/details.aspx?id=39267

  1. Copy the folders called MSOnline and MSOnline Extended from the source

C:\Windows\System32\WindowsPowerShell\v1.0\Modules\

to the folder

C:\Windows\SysWOW64\WindowsPowerShell\v1.0\Modules\

https://stackoverflow.com/a/16018733/5810078.

(But I have actually copied all the possible files from

C:\Windows\System32\WindowsPowerShell\v1.0\

to

C:\Windows\SysWOW64\WindowsPowerShell\v1.0\

(For copying you need to alter the security permissions of that folder))

How to keep footer at bottom of screen

set its position:fixed and bottom:0 so that it will always reside at bottom of your browser windows

tmux status bar configuration

I used tmux-powerline to fully pimp my tmux status bar. I was googling for a way to change to background of the status bar when your typing a tmux command. When I stumbled on this post I thought I should mention it for completeness.

Update: This project is in a maintenance mode and no future functionality is likely to be added. tmux-powerline, with all other powerline projects, is replaced by the new unifying powerline. However this project is still functional and can serve as a lightweight alternative for non-python users.

How to set the current working directory?

It work for Mac also

import os
path="/Users/HOME/Desktop/Addl Work/TimeSeries-Done"
os.chdir(path)

To check working directory

os.getcwd()

Trees in Twitter Bootstrap

For those still searching for a tree with CSS3, this is a fantastic piece of code I found on the net:

http://thecodeplayer.com/walkthrough/css3-family-tree

HTML

<div class="tree">
  <ul>
    <li>
      <a href="#">Parent</a>
      <ul>
        <li>
          <a href="#">Child</a>
          <ul>
            <li>
              <a href="#">Grand Child</a>
            </li>
          </ul>
        </li>
        <li>
          <a href="#">Child</a>
          <ul>
            <li><a href="#">Grand Child</a></li>
            <li>
              <a href="#">Grand Child</a>
              <ul>
                <li>
                  <a href="#">Great Grand Child</a>
                </li>
                <li>
                  <a href="#">Great Grand Child</a>
                </li>
                <li>
                  <a href="#">Great Grand Child</a>
                </li>
              </ul>
            </li>
            <li><a href="#">Grand Child</a></li>
          </ul>
        </li>
      </ul>
    </li>
  </ul>
</div>

CSS

* {margin: 0; padding: 0;}

.tree ul {
  padding-top: 20px; position: relative;

  transition: all 0.5s;
  -webkit-transition: all 0.5s;
  -moz-transition: all 0.5s;
}

.tree li {
  float: left; text-align: center;
  list-style-type: none;
  position: relative;
  padding: 20px 5px 0 5px;

  transition: all 0.5s;
  -webkit-transition: all 0.5s;
  -moz-transition: all 0.5s;
}

/*We will use ::before and ::after to draw the connectors*/

.tree li::before, .tree li::after{
  content: '';
  position: absolute; top: 0; right: 50%;
  border-top: 1px solid #ccc;
  width: 50%; height: 20px;
}
.tree li::after{
  right: auto; left: 50%;
  border-left: 1px solid #ccc;
}

/*We need to remove left-right connectors from elements without 
any siblings*/
.tree li:only-child::after, .tree li:only-child::before {
  display: none;
}

/*Remove space from the top of single children*/
.tree li:only-child{ padding-top: 0;}

/*Remove left connector from first child and 
right connector from last child*/
.tree li:first-child::before, .tree li:last-child::after{
  border: 0 none;
}
/*Adding back the vertical connector to the last nodes*/
.tree li:last-child::before{
  border-right: 1px solid #ccc;
  border-radius: 0 5px 0 0;
  -webkit-border-radius: 0 5px 0 0;
  -moz-border-radius: 0 5px 0 0;
}
.tree li:first-child::after{
  border-radius: 5px 0 0 0;
  -webkit-border-radius: 5px 0 0 0;
  -moz-border-radius: 5px 0 0 0;
}

/*Time to add downward connectors from parents*/
.tree ul ul::before{
  content: '';
  position: absolute; top: 0; left: 50%;
  border-left: 1px solid #ccc;
  width: 0; height: 20px;
}

.tree li a{
  border: 1px solid #ccc;
  padding: 5px 10px;
  text-decoration: none;
  color: #666;
  font-family: arial, verdana, tahoma;
  font-size: 11px;
  display: inline-block;

  border-radius: 5px;
  -webkit-border-radius: 5px;
  -moz-border-radius: 5px;

  transition: all 0.5s;
  -webkit-transition: all 0.5s;
  -moz-transition: all 0.5s;
}

/*Time for some hover effects*/
/*We will apply the hover effect the the lineage of the element also*/
.tree li a:hover, .tree li a:hover+ul li a {
  background: #c8e4f8; color: #000; border: 1px solid #94a0b4;
}
/*Connector styles on hover*/
.tree li a:hover+ul li::after, 
.tree li a:hover+ul li::before, 
.tree li a:hover+ul::before, 
.tree li a:hover+ul ul::before{
  border-color:  #94a0b4;
}

PS: apart from the code, I also like the way the site shows it in action... really innovative.

Check if element is clickable in Selenium Java

wait.until(ExpectedConditions) won't return null, it will either meet the condition or throw TimeoutException.

You can check if the element is displayed and enabled

WebElement element = driver.findElement(By.xpath);
if (element.isDisplayed() && element.isEnabled()) {
    element.click();
}

How to concatenate strings in windows batch file for loop?

Try this, with strings:

set "var=string1string2string3"

and with string variables:

set "var=%string1%%string2%%string3%"

Reading integers from binary file in Python

When you read from a binary file, a data type called bytes is used. This is a bit like list or tuple, except it can only store integers from 0 to 255.

Try:

file_size = fin.read(4)
file_size0 = file_size[0]
file_size1 = file_size[1]
file_size2 = file_size[2]
file_size3 = file_size[3]

Or:

file_size = list(fin.read(4))

Instead of:

file_size = int(fin.read(4))

Can I set variables to undefined or pass undefined as an argument?

To answer your first question, the not operator (!) will coerce whatever it is given into a boolean value. So null, 0, false, NaN and "" (empty string) will all appear false.

java.net.SocketException: Software caused connection abort: recv failed

This error occurs when a connection is closed abruptly (when a TCP connection is reset while there is still data in the send buffer). The condition is very similar to a much more common 'Connection reset by peer'. It can happen sporadically when connecting over the Internet, but also systematically if the timing is right (e.g. with keep-alive connections on localhost).

An HTTP client should just re-open the connection and retry the request. It is important to understand that when a connection is in this state, there is no way out of it other than to close it. Any attempt to send or receive will produce the same error.

Don't use URL.open(), use Apache-Commons HttpClient which has a retry mechanism, connection pooling, keep-alive and many other features.

Sample usage:

HttpClient httpClient = HttpClients.custom()
            .setConnectionTimeToLive(20, TimeUnit.SECONDS)
            .setMaxConnTotal(400).setMaxConnPerRoute(400)
            .setDefaultRequestConfig(RequestConfig.custom()
                    .setSocketTimeout(30000).setConnectTimeout(5000).build())
            .setRetryHandler(new DefaultHttpRequestRetryHandler(5, true))
            .build();
// the httpClient should be re-used because it is pooled and thread-safe.

HttpGet request = new HttpGet(uri);
HttpResponse response = httpClient.execute(request);
reader = new BufferedReader(new InputStreamReader(response.getEntity().getContent()));
// handle response ...

ISO time (ISO 8601) in Python

Local to ISO 8601:

import datetime
datetime.datetime.now().isoformat()
>>> 2020-03-20T14:28:23.382748

UTC to ISO 8601:

import datetime
datetime.datetime.utcnow().isoformat()
>>> 2020-03-20T01:30:08.180856

Local to ISO 8601 without microsecond:

import datetime
datetime.datetime.now().replace(microsecond=0).isoformat()
>>> 2020-03-20T14:30:43

UTC to ISO 8601 with TimeZone information (Python 3):

import datetime
datetime.datetime.utcnow().replace(tzinfo=datetime.timezone.utc).isoformat()
>>> 2020-03-20T01:31:12.467113+00:00

UTC to ISO 8601 with Local TimeZone information without microsecond (Python 3):

import datetime
datetime.datetime.now().astimezone().replace(microsecond=0).isoformat()
>>> 2020-03-20T14:31:43+13:00

Local to ISO 8601 with TimeZone information (Python 3):

import datetime
datetime.datetime.now().astimezone().isoformat()
>>> 2020-03-20T14:32:16.458361+13:00

Notice there is a bug when using astimezone() on utc time. This gives an incorrect result:

datetime.datetime.utcnow().astimezone().isoformat() #Incorrect result

For Python 2, see and use pytz.

What's the best CRLF (carriage return, line feed) handling strategy with Git?

Using core.autocrlf=false stopped all the files from being marked updated as soon as I checked them out in my Visual Studio 2010 project. The other two members of the development team are also using Windows systems so a mixed environment didn't come into play, yet the default settings that came with the repository always marked all files as updated immediately after cloning.

I guess the bottom line is to find what CRLF setting works for your environment. Especially since in many other repositories on our Linux boxes setting autocrlf = true produces better results.

20+ years later and we're still dealing with line ending disparities between OSes... sad.

How to kill zombie process

Sometimes the parent ppid cannot be killed, hence kill the zombie pid

kill -9 $(ps -A -ostat,pid | awk '/[zZ]/{ print $2 }')

scale fit mobile web content using viewport meta tag

Adding style="width:100%;max-width:640px" to the image tag will scale it up to the viewport width, i.e. for larger windows it will look fixed width.

@ViewChild in *ngIf

Another quick "trick" (easy solution) is just to use [hidden] tag instead of *ngIf, just important to know that in that case Angular build the object and paint it under class:hidden this is why the ViewChild work without a problem. So it's important to keep in mind that you should not use hidden on heavy or expensive items that can cause performance issue

  <div class="addTable" [hidden]="CONDITION">

Cannot connect to local SQL Server with Management Studio

Same as matt said. The "SQL Server(SQLEXPRESS)" was stopped. Enabled it by opening Control Panel > Administrative Tools > Services, right-clicking on the "SQL Server(SQLEXPRESS)" service and selecting "Start" from the available options. Could connect fine after that.

Android: keeping a background service alive (preventing process death)

I had a similar issue. On some devices after a while Android kills my service and even startForeground() does not help. And my customer does not like this issue. My solution is to use AlarmManager class to make sure that the service is running when it's necessary. I use AlarmManager to create a kind of watchdog timer. It checks from time to time if the service should be running and restart it. Also I use SharedPreferences to keep the flag whether the service should be running.

Creating/dismissing my watchdog timer:

void setServiceWatchdogTimer(boolean set, int timeout)
{
    Intent intent;
    PendingIntent alarmIntent;
    intent = new Intent(); // forms and creates appropriate Intent and pass it to AlarmManager
    intent.setAction(ACTION_WATCHDOG_OF_SERVICE);
    intent.setClass(this, WatchDogServiceReceiver.class);
    alarmIntent = PendingIntent.getBroadcast(this, 0, intent, PendingIntent.FLAG_UPDATE_CURRENT);
    AlarmManager am=(AlarmManager)getSystemService(Context.ALARM_SERVICE);
    if(set)
        am.set(AlarmManager.RTC_WAKEUP, System.currentTimeMillis() + timeout, alarmIntent);
    else
        am.cancel(alarmIntent);
}

Receiving and processing the intent from the watchdog timer:

/** this class processes the intent and
 *  checks whether the service should be running
 */
public static class WatchDogServiceReceiver extends BroadcastReceiver
{
    @Override
    public void onReceive(Context context, Intent intent)
    {

        if(intent.getAction().equals(ACTION_WATCHDOG_OF_SERVICE))
        {
            // check your flag and 
            // restart your service if it's necessary
            setServiceWatchdogTimer(true, 60000*5); // restart the watchdogtimer
        }
    }
}

Indeed I use WakefulBroadcastReceiver instead of BroadcastReceiver. I gave you the code with BroadcastReceiver just to simplify it.

AngularJS - Trigger when radio button is selected

There are at least 2 different methods of invoking functions on radio button selection:

1) Using ng-change directive:

<input type="radio" ng-model="value" value="foo" ng-change='newValue(value)'>

and then, in a controller:

$scope.newValue = function(value) {
     console.log(value);
}

Here is the jsFiddle: http://jsfiddle.net/ZPcSe/5/

2) Watching the model for changes. This doesn't require anything special on the input level:

<input type="radio" ng-model="value" value="foo">

but in a controller one would have:

$scope.$watch('value', function(value) {
       console.log(value);
 });

And the jsFiddle: http://jsfiddle.net/vDTRp/2/

Knowing more about your the use case would help to propose an adequate solution.

Regex date format validation on Java

java.time

The proper (and easy) way to do date/time validation using Java 8+ is to use the java.time.format.DateTimeFormatter class. Using a regex for validation isn't really ideal for dates. For the example case in this question:

DateTimeFormatter formatter = DateTimeFormatter.ofPattern("yyyy-MM-dd");

try {
    LocalDate date = formatter.parse(text, LocalDate::from);
} catch (DateTimeParseException e) {
    // Thrown if text could not be parsed in the specified format
}

This code will parse the text, validate that it is a valid date, and also return the date as a LocalDate object. Note that the DateTimeFormatter class has a number of static predefined date formats matching ISO standards if your use case matches any of them.

How often does python flush to a file?

Here is another approach, up to the OP to choose which one he prefers.

When including the code below in the __init__.py file before any other code, messages printed with print and any errors will no longer be logged to Ableton's Log.txt but to separate files on your disk:

import sys

path = "/Users/#username#"

errorLog = open(path + "/stderr.txt", "w", 1)
errorLog.write("---Starting Error Log---\n")
sys.stderr = errorLog
stdoutLog = open(path + "/stdout.txt", "w", 1)
stdoutLog.write("---Starting Standard Out Log---\n")
sys.stdout = stdoutLog

(for Mac, change #username# to the name of your user folder. On Windows the path to your user folder will have a different format)

When you open the files in a text editor that refreshes its content when the file on disk is changed (example for Mac: TextEdit does not but TextWrangler does), you will see the logs being updated in real-time.

Credits: this code was copied mostly from the liveAPI control surface scripts by Nathan Ramella

PHP - Get key name of array value

Here is another option

$array = [1=>'one', 2=>'two', 3=>'there'];
$array = array_flip($array);
echo $array['one']; 

Javascript change color of text and background to input value

document.getElementById("fname").style.borderTopColor = 'red';
document.getElementById("fname").style.borderBottomColor = 'red';

How can I download HTML source in C#

You can download files with the WebClient class:

using System.Net;

using (WebClient client = new WebClient ()) // WebClient class inherits IDisposable
{
    client.DownloadFile("http://yoursite.com/page.html", @"C:\localfile.html");

    // Or you can get the file content without saving it
    string htmlCode = client.DownloadString("http://yoursite.com/page.html");
}

How to check if number is divisible by a certain number?

n % x == 0

Means that n can be divided by x. So... for instance, in your case:

boolean isDivisibleBy20 = number % 20 == 0;

Also, if you want to check whether a number is even or odd (whether it is divisible by 2 or not), you can use a bitwise operator:

boolean even = (number & 1) == 0;
boolean odd  = (number & 1) != 0;

Angular 4 - Select default value in dropdown [Reactive Forms]

In Reactive forms. Binding can be done in the component file and usage of ngValue. For more details please go through the following link

https://angular.io/api/forms/SelectControlValueAccessor

import {Component} from '@angular/core';
import {FormControl, FormGroup} from '@angular/forms';

@Component({
  selector: 'example-app',
  template: `
    <form [formGroup]="form">
      <select formControlName="state">
        <option *ngFor="let state of states" [ngValue]="state">
          {{ state.abbrev }}
        </option>
      </select>
    </form>

       <p>Form value: {{ form.value | json }}</p> 
       <!-- {state: {name: 'New York', abbrev: 'NY'} } -->
    `,
})
export class ReactiveSelectComp {
  states = [
    {name: 'Arizona', abbrev: 'AZ'},
    {name: 'California', abbrev: 'CA'},
    {name: 'Colorado', abbrev: 'CO'},
    {name: 'New York', abbrev: 'NY'},
    {name: 'Pennsylvania', abbrev: 'PA'},
  ];

  form = new FormGroup({
    state: new FormControl(this.states[3]),
  });
}

How can I select multiple columns from a subquery (in SQL Server) that should have one record (select top 1) for each record in the main query?

i think that is what you want.

SELECT 
      A.SalesOrderID, 
      A.OrderDate, 
      FooFromB.*

FROM A,
     (SELECT TOP 1 B.Foo
      FROM B
      WHERE A.SalesOrderID = B.SalesOrderID
      ) AS FooFromB

WHERE A.Date BETWEEN '2000-1-4' AND '2010-1-4'

How to stop execution after a certain time in Java?

you should try the new Java Executor Services. http://docs.oracle.com/javase/6/docs/api/java/util/concurrent/ExecutorService.html

With this you don't need to program the loop the time measuring by yourself.

public class Starter {

    public static void main(final String[] args) {
        final ExecutorService service = Executors.newSingleThreadExecutor();

        try {
            final Future<Object> f = service.submit(() -> {
                // Do you long running calculation here
                Thread.sleep(1337); // Simulate some delay
                return "42";
            });

            System.out.println(f.get(1, TimeUnit.SECONDS));
        } catch (final TimeoutException e) {
            System.err.println("Calculation took to long");
        } catch (final Exception e) {
            throw new RuntimeException(e);
        } finally {
            service.shutdown();
        }
    }
}

gitbash command quick reference

git-bash uses standard unix commands.

ls for directory listing cd for change directory

more here -> http://ss64.com/bash/ Not all of these will work, but the file based ones mostly do.

how to set select element as readonly ('disabled' doesnt pass select value on server)

see this answer - HTML form readonly SELECT tag/input

You should keep the select element disabled but also add another hidden input with the same name and value.

If you reenable your SELECT, you should copy it's value to the hidden input in an onchange event.

see this fiddle to demnstrate how to extract the selected value in a disabled select into a hidden field that will be submitted in the form.

<select disabled="disabled" id="sel_test">
    <option value="1">One</option>
    <option value="2">Two</option>
    <option value="3">Three</option>
</select>

<input type="hidden" id="hdn_test" />
<div id="output"></div>

$(function(){
    var select_val = $('#sel_test option:selected').val();
    $('#hdn_test').val(select_val);
    $('#output').text('Selected value is: ' + select_val);
});

hope that helps.

Java 256-bit AES Password-Based Encryption

Consider using Encryptor4j of which I am the author.

First make sure you have Unlimited Strength Jurisdiction Policy files installed before your proceed so that you can use 256-bit AES keys.

Then do the following:

String password = "mysupersecretpassword"; 
Key key = KeyFactory.AES.keyFromPassword(password.toCharArray());
Encryptor encryptor = new Encryptor(key, "AES/CBC/PKCS7Padding", 16);

You can now use the encryptor to encrypt your message. You can also perform streaming encryption if you'd like. It automatically generates and prepends a secure IV for your convenience.

If it's a file that you wish to compress take a look at this answer Encrypting a large file with AES using JAVA for an even simpler approach.

handling DATETIME values 0000-00-00 00:00:00 in JDBC

I solved the problem considerating '00-00-....' isn't a valid date, then, I changed my SQL column definition adding "NULL" expresion to permit null values:

SELECT "-- Tabla item_pedido";
CREATE TABLE item_pedido (
    id INTEGER AUTO_INCREMENT PRIMARY KEY,
    id_pedido INTEGER,
    id_item_carta INTEGER,
    observacion VARCHAR(64),
    fecha_estimada TIMESTAMP,
    fecha_entrega TIMESTAMP NULL, // HERE IS!!.. NULL = DELIVERY DATE NOT SET YET
    CONSTRAINT fk_item_pedido_id_pedido FOREIGN KEY (id_pedido)
        REFERENCES pedido(id),...

Then, I've to be able to insert NULL values, that means "I didnt register that timestamp yet"...

SELECT "++ INSERT item_pedido";
INSERT INTO item_pedido VALUES
(01, 01, 01, 'Ninguna', ADDDATE(@HOY, INTERVAL 5 MINUTE), NULL),
(02, 01, 02, 'Ninguna', ADDDATE(@HOY, INTERVAL 3 MINUTE), NULL),...

The table look that:

mysql> select * from item_pedido;
+----+-----------+---------------+-------------+---------------------+---------------------+
| id | id_pedido | id_item_carta | observacion | fecha_estimada      | fecha_entrega       |
+----+-----------+---------------+-------------+---------------------+---------------------+
|  1 |         1 |             1 | Ninguna     | 2013-05-19 15:09:48 | NULL                |
|  2 |         1 |             2 | Ninguna     | 2013-05-19 15:07:48 | NULL                |
|  3 |         1 |             3 | Ninguna     | 2013-05-19 15:24:48 | NULL                |
|  4 |         1 |             6 | Ninguna     | 2013-05-19 15:06:48 | NULL                |
|  5 |         2 |             4 | Suave       | 2013-05-19 15:07:48 | 2013-05-19 15:09:48 |
|  6 |         2 |             5 | Seco        | 2013-05-19 15:07:48 | 2013-05-19 15:12:48 |
|  7 |         3 |             5 | Con Mayo    | 2013-05-19 14:54:48 | NULL                |
|  8 |         3 |             6 | Bilz        | 2013-05-19 14:57:48 | NULL                |
+----+-----------+---------------+-------------+---------------------+---------------------+
8 rows in set (0.00 sec)

Finally: JPA in action:

@Stateless
@LocalBean
public class PedidosServices {
    @PersistenceContext(unitName="vagonpubPU")
    private EntityManager em;

    private Logger log = Logger.getLogger(PedidosServices.class.getName());

    @SuppressWarnings("unchecked")
    public List<ItemPedido> obtenerPedidosRetrasados() {
        log.info("Obteniendo listado de pedidos retrasados");
        Query qry = em.createQuery("SELECT ip FROM ItemPedido ip, Pedido p WHERE" +
                " ip.fechaEntrega=NULL" +
                " AND ip.idPedido=p.id" +
                " AND ip.fechaEstimada < :arg3" +
                " AND (p.idTipoEstado=:arg0 OR p.idTipoEstado=:arg1 OR p.idTipoEstado=:arg2)");
        qry.setParameter("arg0", Tipo.ESTADO_BOUCHER_ESPERA_PAGO);
        qry.setParameter("arg1", Tipo.ESTADO_BOUCHER_EN_SERVICIO);
        qry.setParameter("arg2", Tipo.ESTADO_BOUCHER_RECIBIDO);
        qry.setParameter("arg3", new Date());

        return qry.getResultList();
    }

At last all its work. I hope that help you.

How can one tell the version of React running at runtime in the browser?

Open the console, then run window.React.version.

This worked for me in Safari and Chrome while upgrading from 0.12.2 to 16.2.0.

Default value for field in Django model

You can also use a callable in the default field, such as:

b = models.CharField(max_length=7, default=foo)

And then define the callable:

def foo():
    return 'bar'

How to connect TFS in Visual Studio code

It seems that the extension cannot be found anymore using "Visual Studio Team Services". Instead, by following the link in Using Visual Studio Code & Team Foundation Version Control on "Get the TFVC plugin working in Visual Studio Code" you get to the Azure Repos Extension for Visual Studio Code GitHub. There it is explained that you now have to look for "Team Azure Repos".

Also, please note, that with the new Settings editor in Visual Studio Code the additional slashes do not have to be added. The path to tf.exe for VS 2017 - if specified using the "user friendly" Settings editor - would be just

C:\Program Files (x86)\Microsoft Visual Studio\2017\Professional\Common7\IDE\CommonExtensions\Microsoft\TeamFoundation\Team Explorer\TF.exe

Array Index Out of Bounds Exception (Java)

for ( i = 0; i < total.length; i++ ); // remove this
{
    if (total[i]!=0)
        System.out.println( "Letter" + (char)( 'a' + i) + " count =" + total[i]);
}

The for loop loops until i=26 (where 26 is total.length) and then your if is executed, going over the bounds of the array. Remove the ; at the end of the for loop.

Why is 22 the default port number for SFTP?

From Wikipedia:

Applications implementing common services often use specifically reserved, well-known port numbers for receiving service requests from client hosts. This process is known as listening and involves the receipt of a request on the well-known port and reestablishing one-to-one server-client communications on another private port, so that other clients may also contact the well-known service port. The well-known ports are defined by convention overseen by the Internet Assigned Numbers Authority (IANA).

Source

So as others mentioned, it's a convention.

Reset IntelliJ UI to Default

All above answers are correct, but you loose configuration settings.

But if your IDE's only themes or fonts are changed or some UI related issues and you want to restore to default theme, then just delete

${user.home}/.IntelliJIdea13/config/options/options.xml

file while IDE is not running, then after next restart IDE's theme will gets reset to default.

Spark: Add column to dataframe conditionally

My bad, I had missed one part of the question.

Best, cleanest way is to use a UDF. Explanation within the code.

// create some example data...BY DataFrame
// note, third record has an empty string
case class Stuff(a:String,b:Int)
val d= sc.parallelize(Seq( ("a",1),("b",2),
     ("",3) ,("d",4)).map { x => Stuff(x._1,x._2)  }).toDF

// now the good stuff.
import org.apache.spark.sql.functions.udf
// function that returns 0 is string empty 
val func = udf( (s:String) => if(s.isEmpty) 0 else 1 )
// create new dataframe with added column named "notempty"
val r = d.select( $"a", $"b", func($"a").as("notempty") )

    scala> r.show
+---+---+--------+
|  a|  b|notempty|
+---+---+--------+
|  a|  1|    1111|
|  b|  2|    1111|
|   |  3|       0|
|  d|  4|    1111|
+---+---+--------+

Why shouldn't I use mysql_* functions in PHP?

The MySQL extension:

  • Is not under active development
  • Is officially deprecated as of PHP 5.5 (released June 2013).
  • Has been removed entirely as of PHP 7.0 (released December 2015)
    • This means that as of 31 Dec 2018 it does not exist in any supported version of PHP. If you are using a version of PHP which supports it, you are using a version which doesn't get security problems fixed.
  • Lacks an OO interface
  • Doesn't support:
    • Non-blocking, asynchronous queries
    • Prepared statements or parameterized queries
    • Stored procedures
    • Multiple Statements
    • Transactions
    • The "new" password authentication method (on by default in MySQL 5.6; required in 5.7)
    • Any of the new functionality in MySQL 5.1 or later

Since it is deprecated, using it makes your code less future proof.

Lack of support for prepared statements is particularly important as they provide a clearer, less error-prone method of escaping and quoting external data than manually escaping it with a separate function call.

See the comparison of SQL extensions.

Meaning of Choreographer messages in Logcat

This if an Info message that could pop in your LogCat on many situations.

In my case, it happened when I was inflating several views from XML layout files programmatically. The message is harmless by itself, but could be the sign of a later problem that would use all the RAM your App is allowed to use and cause the mega-evil Force Close to happen. I have grown to be the kind of Developer that likes to see his Log WARN/INFO/ERROR Free. ;)

So, this is my own experience:

I got the message:

10-09 01:25:08.373: I/Choreographer(11134): Skipped XXX frames!  The application may be doing too much work on its main thread.

... when I was creating my own custom "super-complex multi-section list" by inflating a view from XML and populating its fields (images, text, etc...) with the data coming from the response of a REST/JSON web service (without paging capabilities) this views would act as rows, sub-section headers and section headers by adding all of them in the correct order to a LinearLayout (with vertical orientation inside a ScrollView). All of that to simulate a listView with clickable elements... but well, that's for another question.

As a responsible Developer you want to make the App really efficient with the system resources, so the best practice for lists (when your lists are not so complex) is to use a ListActivity or ListFragment with a Loader and fill the ListView with an Adapter, this is supposedly more efficient, in fact it is and you should do it all the time, again... if your list is not so complex.

Solution: I implemented paging on my REST/JSON web service to prevent "big response sizes" and I wrapped the code that added the "rows", "section headers" and "sub-section headers" views on an AsyncTask to keep the Main Thread cool.

So... I hope my experience helps someone else that is cracking their heads open with this Info message.

Happy hacking!

pthread_join() and pthread_exit()

In pthread_exit, ret is an input parameter. You are simply passing the address of a variable to the function.

In pthread_join, ret is an output parameter. You get back a value from the function. Such value can, for example, be set to NULL.

Long explanation:

In pthread_join, you get back the address passed to pthread_exit by the finished thread. If you pass just a plain pointer, it is passed by value so you can't change where it is pointing to. To be able to change the value of the pointer passed to pthread_join, it must be passed as a pointer itself, that is, a pointer to a pointer.

How to get scrollbar position with Javascript?

I think the following function can help to have scroll coordinate values:

const getScrollCoordinate = (el = window) => ({
  x: el.pageXOffset || el.scrollLeft,
  y: el.pageYOffset || el.scrollTop,
});

I got this idea from this answer with a little change.

How to enable file sharing for my app?

In Xcode 8.3.3 add new row in .plist with true value

Application supports iTunes file sharing

Adding blur effect to background in swift

let blurEffect = UIBlurEffect(style: UIBlurEffect.Style.dark)
                    let blurEffectView = UIVisualEffectView(effect: blurEffect)
                    blurEffectView.backgroundColor = .black
                    blurEffectView.alpha = 0.5
                    blurEffectView.frame = topView.bounds
                    if !self.presenting {
                        blurEffectView.frame.origin.x = 0
                    } else {
                        blurEffectView.frame.origin.x = -topView.frame.width
                    }
                    blurEffectView.frame.origin.x = -topView.frame.width
                    blurEffectView.autoresizingMask = [.flexibleWidth, .flexibleHeight]
                    UIView.animate(withDuration: 0.2, delay: 0.0, options: [.curveEaseIn]) {
                        if !self.presenting {
                            blurEffectView.frame.origin.x = -topView.frame.width
                        } else {
                            blurEffectView.frame.origin.x = 0
                        }
                        view.addSubview(blurEffectView)
                    } completion: { (status) in
                        
                    }

Add a auto increment primary key to existing table in oracle

Say your table is called t1 and your primary-key is called id
First, create the sequence:

create sequence t1_seq start with 1 increment by 1 nomaxvalue; 

Then create a trigger that increments upon insert:

create trigger t1_trigger
before insert on t1
for each row
   begin
     select t1_seq.nextval into :new.id from dual;
   end;

How do I read text from the clipboard?

If you don't want to install extra packages, ctypes can get the job done as well.

import ctypes

CF_TEXT = 1

kernel32 = ctypes.windll.kernel32
kernel32.GlobalLock.argtypes = [ctypes.c_void_p]
kernel32.GlobalLock.restype = ctypes.c_void_p
kernel32.GlobalUnlock.argtypes = [ctypes.c_void_p]
user32 = ctypes.windll.user32
user32.GetClipboardData.restype = ctypes.c_void_p

def get_clipboard_text():
    user32.OpenClipboard(0)
    try:
        if user32.IsClipboardFormatAvailable(CF_TEXT):
            data = user32.GetClipboardData(CF_TEXT)
            data_locked = kernel32.GlobalLock(data)
            text = ctypes.c_char_p(data_locked)
            value = text.value
            kernel32.GlobalUnlock(data_locked)
            return value
    finally:
        user32.CloseClipboard()

print(get_clipboard_text())

How to add Action bar options menu in Android Fragments

I am late for the answer but I think this is another solution which is not mentioned here so posting.

Step 1: Make a xml of menu which you want to add like I have to add a filter action on my action bar so I have created a xml filter.xml. The main line to notice is android:orderInCategory this will show the action icon at first or last wherever you want to show. One more thing to note down is the value, if the value is less then it will show at first and if value is greater then it will show at last.

filter.xml

<menu xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools" >


    <item
        android:id="@+id/action_filter"
        android:title="@string/filter"
        android:orderInCategory="10"
        android:icon="@drawable/filter"
        app:showAsAction="ifRoom" />


</menu>

Step 2: In onCreate() method of fragment just put the below line as mentioned, which is responsible for calling back onCreateOptionsMenu(Menu menu, MenuInflater inflater) method just like in an Activity.

@Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setHasOptionsMenu(true);
    }

Step 3: Now add the method onCreateOptionsMenu which will be override as:

@Override
    public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) {
        inflater.inflate(R.menu.filter, menu);  // Use filter.xml from step 1
    }

Step 4: Now add onOptionsItemSelected method by which you can implement logic whatever you want to do when you select the added action icon from actionBar:

@Override
    public boolean onOptionsItemSelected(MenuItem item) {
        int id = item.getItemId();
        if(id == R.id.action_filter){
            //Do whatever you want to do 
            return true;
        }

        return super.onOptionsItemSelected(item);
    }

Running powershell script within python script, how to make python print the powershell output while it is running

  1. Make sure you can run powershell scripts (it is disabled by default). Likely you have already done this. http://technet.microsoft.com/en-us/library/ee176949.aspx

    Set-ExecutionPolicy RemoteSigned
    
  2. Run this python script on your powershell script helloworld.py:

    # -*- coding: iso-8859-1 -*-
    import subprocess, sys
    
    p = subprocess.Popen(["powershell.exe", 
                  "C:\\Users\\USER\\Desktop\\helloworld.ps1"], 
                  stdout=sys.stdout)
    p.communicate()
    

This code is based on python3.4 (or any 3.x series interpreter), though it should work on python2.x series as well.

C:\Users\MacEwin\Desktop>python helloworld.py
Hello World

How do I draw a grid onto a plot in Python?

Here is a small example how to add a matplotlib grid in Gtk3 with Python 2 (not working in Python 3):

#!/usr/bin/env python
#-*- coding: utf-8 -*-

import gi
gi.require_version('Gtk', '3.0')
from gi.repository import Gtk
from matplotlib.figure import Figure
from matplotlib.backends.backend_gtk3agg import FigureCanvasGTK3Agg as FigureCanvas

win = Gtk.Window()
win.connect("delete-event", Gtk.main_quit)
win.set_title("Embedding in GTK3")

f = Figure(figsize=(1, 1), dpi=100)
ax = f.add_subplot(111)
ax.grid()

canvas = FigureCanvas(f)
canvas.set_size_request(400, 400)
win.add(canvas)

win.show_all()
Gtk.main()

enter image description here

How can I get Git to follow symlinks?

I'm using Git 1.5.4.3 and it's following the passed symlink if it has a trailing slash. E.g.

# Adds the symlink itself
$ git add symlink

# Follows symlink and adds the denoted directory's contents
$ git add symlink/

What are the different types of keys in RDBMS?

(I) Super Key – An attribute or a combination of attribute that is used to identify the records uniquely is known as Super Key. A table can have many Super Keys.

E.g. of Super Key

  1. ID
  2. ID, Name
  3. ID, Address
  4. ID, Department_ID
  5. ID, Salary
  6. Name, Address
  7. Name, Address, Department_ID

So on as any combination which can identify the records uniquely will be a Super Key.

(II) Candidate Key – It can be defined as minimal Super Key or irreducible Super Key. In other words an attribute or a combination of attribute that identifies the record uniquely but none of its proper subsets can identify the records uniquely.

E.g. of Candidate Key

  1. ID
  2. Name, Address

For above table we have only two Candidate Keys (i.e. Irreducible Super Key) used to identify the records from the table uniquely. ID Key can identify the record uniquely and similarly combination of Name and Address can identify the record uniquely, but neither Name nor Address can be used to identify the records uniquely as it might be possible that we have two employees with similar name or two employees from the same house.

(III) Primary Key – A Candidate Key that is used by the database designer for unique identification of each row in a table is known as Primary Key. A Primary Key can consist of one or more attributes of a table.

E.g. of Primary Key - Database designer can use one of the Candidate Key as a Primary Key. In this case we have “ID” and “Name, Address” as Candidate Key, we will consider “ID” Key as a Primary Key as the other key is the combination of more than one attribute.

(IV) Foreign Key – A foreign key is an attribute or combination of attribute in one base table that points to the candidate key (generally it is the primary key) of another table. The purpose of the foreign key is to ensure referential integrity of the data i.e. only values that are supposed to appear in the database are permitted.

E.g. of Foreign Key – Let consider we have another table i.e. Department Table with Attributes “Department_ID”, “Department_Name”, “Manager_ID”, ”Location_ID” with Department_ID as an Primary Key. Now the Department_ID attribute of Employee Table (dependent or child table) can be defined as the Foreign Key as it can reference to the Department_ID attribute of the Departments table (the referenced or parent table), a Foreign Key value must match an existing value in the parent table or be NULL.

(V) Composite Key – If we use multiple attributes to create a Primary Key then that Primary Key is called Composite Key (also called a Compound Key or Concatenated Key).

E.g. of Composite Key, if we have used “Name, Address” as a Primary Key then it will be our Composite Key.

(VI) Alternate Key – Alternate Key can be any of the Candidate Keys except for the Primary Key.

E.g. of Alternate Key is “Name, Address” as it is the only other Candidate Key which is not a Primary Key.

(VII) Secondary Key – The attributes that are not even the Super Key but can be still used for identification of records (not unique) are known as Secondary Key.

E.g. of Secondary Key can be Name, Address, Salary, Department_ID etc. as they can identify the records but they might not be unique.

Get the current fragment object

You can get the list of the fragments and look to the last one.

    FragmentManager fm = getSupportFragmentManager();
    List<Fragment> fragments = fm.getFragments();
    Fragment lastFragment = fragments.get(fragments.size() - 1);

But sometimes (when you navigate back) list size remains same but some of the last elements are null. So in the list I iterated to the last not null fragment and used it.

    FragmentManager fm = getSupportFragmentManager();
    if (fm != null) {
        List<Fragment> fragments = fm.getFragments();
        if (fragments != null) {
            for(int i = fragments.size() - 1; i >= 0; i--){
                Fragment fragment = fragments.get(i);
                if(fragment != null) {
                    // found the current fragment

                    // if you want to check for specific fragment class
                    if(fragment instanceof YourFragmentClass) {
                        // do something
                    }
                    break;
                }
            }
        }
    }

how to get the value of a textarea in jquery?

You should check the textarea is null before you use val() otherwise, you will get undefined error.

if ($('textarea#message') != undefined) {
   var message = $('textarea#message').val();
}

Then, you could do whatever with message.

Communication between tabs or windows

There is a modern API dedicated for this purpose - Broadcast Channel

It is as easy as:

var bc = new BroadcastChannel('test_channel');

bc.postMessage('This is a test message.'); /* send */

bc.onmessage = function (ev) { console.log(ev); } /* receive */

There is no need for the message to be just a DOMString, any kind of object can be sent.

Probably, apart from API cleanness, it is the main benefit of this API - no object stringification.

Currently supported only in Chrome and Firefox, but you can find a polyfill that uses localStorage.

invalid multibyte char (US-ASCII) with Rails and Ruby 1.9

Just a note that as of Ruby 2.0 there is no need to add # encoding: utf-8. UTF-8 is automatically detected.

boolean in an if statement

Revisa https://www.w3schools.com/js/js_comparisons.asp

example:

var p=5;

p==5 ? true
p=="5" ?  true
p==="5" ? false

=== means same type also same value == just same value

enter image description here

How to compute the sum and average of elements in an array?

In ES6-ready browsers this polyfill may be helpful.

Math.sum = (...a) => Array.prototype.reduce.call(a,(a,b) => a+b)

Math.avg = (...a) => this.sum(...a)/a.length;

You can share same call method between Math.sum,Math.avg and Math.max,such as

var maxOne = Math.max(1,2,3,4) // 4;

you can use Math.sum as

var sumNum = Math.sum(1,2,3,4) // 10

or if you have an array to sum up,you can use

var sumNum = Math.sum.apply(null,[1,2,3,4]) // 10

just like

var maxOne = Math.max.apply(null,[1,2,3,4]) // 4

SDK Location not found Android Studio + Gradle

If none of the answers work for you which happened to me on macbook pro in one of the projects you can always try to run Android Studio with an alias command passing sdk.dir with each run:

alias studio='launchctl setenv ANDROID_HOME '\''/Users/username/Library/Android/sdk'\'' && open -a '\''Android Studio'\'''

How do I load an org.w3c.dom.Document from XML in a string?

Just had a similar problem, except i needed a NodeList and not a Document, here's what I came up with. It's mostly the same solution as before, augmented to get the root element down as a NodeList and using erickson's suggestion of using an InputSource instead for character encoding issues.

private String DOC_ROOT="root";
String xml=getXmlString();
Document xmlDoc=loadXMLFrom(xml);
Element template=xmlDoc.getDocumentElement();
NodeList nodes=xmlDoc.getElementsByTagName(DOC_ROOT);

public static Document loadXMLFrom(String xml) throws Exception {
        InputSource is= new InputSource(new StringReader(xml));
        DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
        factory.setNamespaceAware(true);
        DocumentBuilder builder = null;
        builder = factory.newDocumentBuilder();
        Document doc = builder.parse(is);
        return doc;
    }

VBA copy rows that meet criteria to another sheet

After formatting the previous answer to my own code, I have found an efficient way to copy all necessary data if you are attempting to paste the values returned via AutoFilter to a separate sheet.

With .Range("A1:A" & LastRow)
    .Autofilter Field:=1, Criteria1:="=*" & strSearch & "*"
    .Offset(1,0).SpecialCells(xlCellTypeVisible).Cells.Copy
    Sheets("Sheet2").activate
    DestinationRange.PasteSpecial
End With

In this block, the AutoFilter finds all of the rows that contain the value of strSearch and filters out all of the other values. It then copies the cells (using offset in case there is a header), opens the destination sheet and pastes the values to the specified range on the destination sheet.

Counting no of rows returned by a select query

select COUNT(*)
from Monitor as m
    inner join Monitor_Request as mr on mr.Company_ID=m.Company_id
    group by m.Company_id
    having COUNT(m.Monitor_id)>=5

Where is adb.exe in windows 10 located?

Mine was in: C:\NVPACK\android-sdk-windows\platform-tools

When to use HashMap over LinkedList or ArrayList and vice-versa

Lists represent a sequential ordering of elements. Maps are used to represent a collection of key / value pairs.

While you could use a map as a list, there are some definite downsides of doing so.

Maintaining order: - A list by definition is ordered. You add items and then you are able to iterate back through the list in the order that you inserted the items. When you add items to a HashMap, you are not guaranteed to retrieve the items in the same order you put them in. There are subclasses of HashMap like LinkedHashMap that will maintain the order, but in general order is not guaranteed with a Map.

Key/Value semantics: - The purpose of a map is to store items based on a key that can be used to retrieve the item at a later point. Similar functionality can only be achieved with a list in the limited case where the key happens to be the position in the list.

Code readability Consider the following examples.

    // Adding to a List
    list.add(myObject);         // adds to the end of the list
    map.put(myKey, myObject);   // sure, you can do this, but what is myKey?
    map.put("1", myObject);     // you could use the position as a key but why?

    // Iterating through the items
    for (Object o : myList)           // nice and easy
    for (Object o : myMap.values())   // more code and the order is not guaranteed

Collection functionality Some great utility functions are available for lists via the Collections class. For example ...

    // Randomize the list
    Collections.shuffle(myList);

    // Sort the list
    Collections.sort(myList, myComparator);  

Hope this helps,

regular expression for anything but an empty string

You could also use:

public static bool IsWhiteSpace(string s) 
{
    return s.Trim().Length == 0;
}

"cannot resolve symbol R" in Android Studio

What worked for me was:

  1. Created a new project.

  2. Found that the R is wokring!

  3. Compared all the configurations.
  4. Found that difference in gradle file: compile 'com.android.support:appcompat-v7:23.4.0'

  5. Sync, and it worked again!

Multi-dimensional arrays in Bash

Bash does not support multidimensional arrays, nor hashes, and it seems that you want a hash that values are arrays. This solution is not very beautiful, a solution with an xml file should be better :

array=('d1=(v1 v2 v3)' 'd2=(v1 v2 v3)')
for elt in "${array[@]}";do eval $elt;done
echo "d1 ${#d1[@]} ${d1[@]}"
echo "d2 ${#d2[@]} ${d2[@]}"

EDIT: this answer is quite old, since since bash 4 supports hash tables, see also this answer for a solution without eval.

How do I pretty-print existing JSON data with Java?

In one line:

String niceFormattedJson = JsonWriter.formatJson(jsonString)

or

System.out.println(JsonWriter.formatJson(jsonString.toString()));

The json-io libray (https://github.com/jdereg/json-io) is a small (75K) library with no other dependencies than the JDK.

In addition to pretty-printing JSON, you can serialize Java objects (entire Java object graphs with cycles) to JSON, as well as read them in.

How can I convert JSON to CSV?

This code should work for you, assuming that your JSON data is in a file called data.json.

import json
import csv

with open("data.json") as file:
    data = json.load(file)

with open("data.csv", "w") as file:
    csv_file = csv.writer(file)
    for item in data:
        fields = list(item['fields'].values())
        csv_file.writerow([item['pk'], item['model']] + fields)

Play infinitely looping video on-load in HTML5

As of April 2018, Chrome (along with several other major browsers) now require the muted attribute too.

Therefore, you should use

<video width="320" height="240" autoplay loop muted>
  <source src="movie.mp4" type="video/mp4" />
</video>

xsd:boolean element type accept "true" but not "True". How can I make it accept it?

If you're on Linux, or have cygwin available on Windows, you can run the input XML through a simple sed script that will replace <Active>True</Active> with <Active>true</Active>, like so:

cat <your XML file> | sed 'sX<Active>True</Active>X<Active>true</Active>X' | xmllint --schema -

If you're not, you can still use a non-validating xslt pocessor (xalan, saxon etc.) to run a simple xslt transformation on the input, and only then pipe it to xmllint.

What the xsl should contain something like below, for the example you listed above (the xslt processor should be 2.0 capable):

<?xml version="1.0"?>
<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform" version="2.0">
    <xsl:output method="xml" indent="yes"/>
    <xsl:template match="/">
    <xsl:for-each select="XML">
        <xsl:for-each select="Active">
            <xsl:value-of select=" replace(current(), 'True','true')"/>
        </xsl:for-each>
    </xsl:for-each>
    </xsl:template>
</xsl:stylesheet>

Warning: date_format() expects parameter 1 to be DateTime

This may help

$formattedweddingdate =date('d-m-Y',strtotime($weddingdate));

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

A few considerations on the subject:

  • The parenthesis:

    The browser (engine/parser) associates the keyword function with

    [optional name]([optional parameters]){...code...}
    

    So in an expression like function(){}() the last parenthesis makes no sense.

    Now think at

    name=function(){} ; name() !?
    

Yes, the first pair of parenthesis force the anonymous function to turn into a variable (stored expression) and the second launches evaluation/execution, so ( function(){} )() makes sense.

  • The utility: ?

    1. For executing some code on load and isolate the used variables from the rest of the page especially when name conflicts are possible;

    2. Replace eval("string") with

      (new Function("string"))()

    3. Wrap long code for " =?: " operator like:

      result = exp_to_test ? (function(){... long_code ...})() : (function(){...})();

Sorting an Array of int using BubbleSort

This isn't the bubble sort algorithm, you need to repeat until you have nothing to swap :

public void sortArray(int[] x) {//go through the array and sort from smallest to highest
  for(;;) {
      boolean s = false;
      for(int i=1; i<x.length; i++) {
         int temp=0;
         if(x[i-1] > x[i]) {
            temp = x[i-1];
            x[i-1] = x[i];
            x[i] = temp;
            s = true;
         }
      }
      if (!s) return;
  }
}

Subtracting time.Duration from time in Go

In response to Thomas Browne's comment, because lnmx's answer only works for subtracting a date, here is a modification of his code that works for subtracting time from a time.Time type.

package main

import (
    "fmt"
    "time"
)

func main() {
    now := time.Now()

    fmt.Println("now:", now)

    count := 10
    then := now.Add(time.Duration(-count) * time.Minute)
    // if we had fix number of units to subtract, we can use following line instead fo above 2 lines. It does type convertion automatically.
    // then := now.Add(-10 * time.Minute)
    fmt.Println("10 minutes ago:", then)
}

Produces:

now: 2009-11-10 23:00:00 +0000 UTC
10 minutes ago: 2009-11-10 22:50:00 +0000 UTC

Not to mention, you can also use time.Hour or time.Second instead of time.Minute as per your needs.

Playground: https://play.golang.org/p/DzzH4SA3izp

Spaces in URLs?

Spaces are simply replaced by "%20" like :

http://www.example.com/my%20beautiful%20page

How to display binary data as image - extjs 4

In front-end JavaScript/HTML, you can load a binary file as an image, you do not have to convert to base64:

<img src="http://engci.nabisco.com/artifactory/repo/folder/my-image">

my-image is a binary image file. This will load just fine.

How to read XML using XPath in Java

You need something along the lines of this:

DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
DocumentBuilder builder = factory.newDocumentBuilder();
Document doc = builder.parse(<uri_as_string>);
XPathFactory xPathfactory = XPathFactory.newInstance();
XPath xpath = xPathfactory.newXPath();
XPathExpression expr = xpath.compile(<xpath_expression>);

Then you call expr.evaluate() passing in the document defined in that code and the return type you are expecting, and cast the result to the object type of the result.

If you need help with a specific XPath expressions, you should probably ask it as separate questions (unless that was your question in the first place here - I understood your question to be how to use the API in Java).

Edit: (Response to comment): This XPath expression will get you the text of the first URL element under PowerBuilder:

/howto/topic[@name='PowerBuilder']/url/text()

This will get you the second:

/howto/topic[@name='PowerBuilder']/url[2]/text()

You get that with this code:

expr.evaluate(doc, XPathConstants.STRING);

If you don't know how many URLs are in a given node, then you should rather do something like this:

XPathExpression expr = xpath.compile("/howto/topic[@name='PowerBuilder']/url");
NodeList nl = (NodeList) expr.evaluate(doc, XPathConstants.NODESET);

And then loop over the NodeList.

Android: How to rotate a bitmap on a center point

I hope the following sequence of code will help you:

Bitmap targetBitmap = Bitmap.createBitmap(targetWidth, targetHeight, config);
Canvas canvas = new Canvas(targetBitmap);
Matrix matrix = new Matrix();
matrix.setRotate(mRotation,source.getWidth()/2,source.getHeight()/2);
canvas.drawBitmap(source, matrix, new Paint());

If you check the following method from ~frameworks\base\graphics\java\android\graphics\Bitmap.java

public static Bitmap createBitmap(Bitmap source, int x, int y, int width, int height,
        Matrix m, boolean filter)

this would explain what it does with rotation and translate.

Command to get latest Git commit hash from a branch

Try using git log -n 1 after doing a git checkout branchname. This shows the commit hash, author, date and commit message for the latest commit.

Perform a git pull origin/branchname first, to make sure your local repo matches upstream.

If perhaps you would only like to see a list of the commits your local branch is behind on the remote branch do this:

git fetch origin
git cherry localbranch remotebranch

This will list all the hashes of the commits that you have not yet merged into your local branch.

PL/SQL print out ref cursor returned by a stored procedure

Note: This code is untested

Define a record for your refCursor return type, call it rec. For example:

TYPE MyRec IS RECORD (col1 VARCHAR2(10), col2 VARCHAR2(20), ...);  --define the record
rec MyRec;        -- instantiate the record

Once you have the refcursor returned from your procedure, you can add the following code where your comments are now:

LOOP
  FETCH refCursor INTO rec;
  EXIT WHEN refCursor%NOTFOUND;
  dbms_output.put_line(rec.col1||','||rec.col2||','||...);
END LOOP;

How to get last 7 days data from current datetime to last 7 days in sql server

Try something like:

 SELECT id, NewsHeadline as news_headline, NewsText as news_text, state CreatedDate as created_on
 FROM News 
 WHERE CreatedDate >= DATEADD(day,-7, GETDATE())

How to insert blank lines in PDF?

You can add empty line ;

 Paragraph p = new Paragraph();
 // add one empty line
  addEmptyLine(p, 1);
 // add 3 empty line
  addEmptyLine(p, 3);


private static void addEmptyLine(Paragraph paragraph, int number) {
    for (int i = 0; i < number; i++) {
      paragraph.add(new Paragraph(" "));
    }
  }

Android: Is it possible to display video thumbnails?

I really suggest you to use the Glide library. It's among the most efficient way to generate and display a video thumbnail for a local video file.

Just add this line to your gradle file :

compile 'com.github.bumptech.glide:glide:3.7.0'

And it will become as simple as :

String filePath = "/storage/emulated/0/Pictures/example_video.mp4";

Glide  
    .with( context )
    .load( Uri.fromFile( new File( filePath ) ) )
    .into( imageViewGifAsBitmap );

You can find more informations here : https://futurestud.io/blog/glide-displaying-gifs-and-videos

Cheers !

Find all paths between two graph nodes

Finding all possible paths is a hard problem, since there are exponential number of simple paths. Even finding the kth shortest path [or longest path] are NP-Hard.

One possible solution to find all paths [or all paths up to a certain length] from s to t is BFS, without keeping a visited set, or for the weighted version - you might want to use uniform cost search

Note that also in every graph which has cycles [it is not a DAG] there might be infinite number of paths between s to t.

Reading InputStream as UTF-8

I ran into the same problem every time it finds a special character marks it as ??. to solve this, I tried using the encoding: ISO-8859-1

BufferedReader br = new BufferedReader(new InputStreamReader(new FileInputStream("txtPath"),"ISO-8859-1"));

while ((line = br.readLine()) != null) {

}

I hope this can help anyone who sees this post.

How to use the PI constant in C++

Pi can be calculated as atan(1)*4. You could calculate the value this way and cache it.

<strong> vs. font-weight:bold & <em> vs. font-style:italic

<strong> and <em> - unlike <b> and <i> - have clear purpose for web browsers for the blind.

A blind person doesn't browse the web visually, but by sound such as text readers. <strong> and <em>, in addition to encouraging something to be bold or italic, also convey loudness or stressing syllables respectively (OH MY! & Ooooooh Myyyyyyy!). Audio-only browsers are unpredictable when it comes to <b> and <i>... they may make them loud or stress them or they may not... you never can be sure unless you use <strong> and <em>.

How to configure SSL certificates with Charles Web Proxy and the latest Android Emulator on Windows?

In Charles, go to Proxy>>Proxy Settings and select the SSL tab. Add your host to the list of Locations.

For example, if your secure call is going to https://secure.example.com, you can enter secure.example.com, or *.example.com.

Once the above is in place, you may need to right-click on the call in the main Charles window and select the SSL Proxying option.

Hope this helps.

How can I get a list of all functions stored in the database of a particular schema in PostgreSQL?

Run below SQL query to create a view which will show all functions:

CREATE OR REPLACE VIEW show_functions AS
    SELECT routine_name FROM information_schema.routines 
        WHERE routine_type='FUNCTION' AND specific_schema='public';

Get value from input (AngularJS)

If your markup is bound to a controller, directive or anything else with a $scope:

console.log($scope.movie);

How can we redirect a Java program console output to multiple files?

You can set the output of System.out programmatically by doing:

System.setOut(new PrintStream(new BufferedOutputStream(new FileOutputStream("/location/to/console.out")), true));

Edit:

Due to the fact that this solution is based on a PrintStream, we can enable autoFlush, but according to the docs:

autoFlush - A boolean; if true, the output buffer will be flushed whenever a byte array is written, one of the println methods is invoked, or a newline character or byte ('\n') is written

So if a new line isn't written, remember to System.out.flush() manually.

(Thanks Robert Tupelo-Schneck)

How to create custom spinner like border around the spinner with down triangle on the right side?

Spinner

<Spinner
    android:id="@+id/To_Units"
    style="@style/spinner_style" />

style.xml

    <style name="spinner_style">
          <item name="android:layout_width">match_parent</item>
          <item name="android:layout_height">wrap_content</item>
          <item name="android:background">@drawable/gradient_spinner</item>
          <item name="android:layout_margin">10dp</item>
          <item name="android:paddingLeft">8dp</item>
          <item name="android:paddingRight">20dp</item>
          <item name="android:paddingTop">5dp</item>
          <item name="android:paddingBottom">5dp</item>
          <item name="android:popupBackground">#DFFFFFFF</item>
     </style>

gradient_spinner.xml (in drawable folder)

<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">

    <item><layer-list>
            <item><shape>
                    <gradient android:angle="90" android:endColor="#B3BBCC" android:startColor="#E8EBEF" android:type="linear" />

                    <stroke android:width="1dp" android:color="#000000" />

                    <corners android:radius="4dp" />

                    <padding android:bottom="3dp" android:left="3dp" android:right="3dp" android:top="3dp" />
                </shape></item>
            <item ><bitmap android:gravity="bottom|right" android:src="@drawable/spinner_arrow" />
            </item>
        </layer-list></item>

</selector>  

@drawable/spinner_arrow is your bottom right corner image

How to trigger the window resize event in JavaScript?

I believe this should work for all browsers:

var event;
if (typeof (Event) === 'function') {
    event = new Event('resize');
} else { /*IE*/
    event = document.createEvent('Event');
    event.initEvent('resize', true, true);
}
window.dispatchEvent(event);

c++ and opencv get and set pixel color to Mat

I would not use .at for performance reasons.

Define a struct:

//#pragma pack(push, 2) //not useful (see comments below)
struct RGB {
    uchar blue;
    uchar green;
    uchar red;  };

And then use it like this on your cv::Mat image:

RGB& rgb = image.ptr<RGB>(y)[x];

image.ptr(y) gives you a pointer to the scanline y. And iterate through the pixels with loops of x and y

How to display an unordered list in two columns?

I like the solution for modern browsers, but the bullets are missing, so I add it a little trick:

http://jsfiddle.net/HP85j/419/

ul {
    list-style-type: none;
    columns: 2;
    -webkit-columns: 2;
    -moz-columns: 2;
}


li:before {
  content: "• ";
}

enter image description here

Avoiding "resource is out of sync with the filesystem"

This happens to me all the time.

Go to the error log, find the exception, and open a few levels until you can see something more like a root cause. Does it says "Resource is out of sync with the file system" ?

When renaming packages, of course, Eclipse has to move files around in the file system. Apparently what happens is that it later discovers that something it thinks it needs to clean up has been renamed, can't find it, throws an exception.

There are a couple of things you might try. First, go to Window: Preferences, Workspace, and enable "Refresh Automatically". In theory this should fix the problem, but for me, it didn't.

Second, if you are doing a large refactoring with subpackages, do the subpackages one at a time, from the bottom up, and explicitly refresh with the file system after each subpackage is renamed.

Third, just ignore the error: when the error dialog comes up, click Abort to preserve the partial change, instead of rolling it back. Try it again, and again, and you may find you can get through the entire operation using multiple retries.

Best way to center a <div> on a page vertically and horizontally?

Solution

Using only two lines of CSS, utilizing the magical power of Flexbox

.parent { display: flex; }
.child { margin: auto }

SVG: text inside rect

This is not possible. If you want to display text inside a rect element you should put them both in a group with the text element coming after the rect element ( so it appears on top ).

_x000D_
_x000D_
<svg xmlns="http://www.w3.org/2000/svg">_x000D_
  <g>_x000D_
    <rect x="0" y="0" width="100" height="100" fill="red"></rect>_x000D_
    <text x="0" y="50" font-family="Verdana" font-size="35" fill="blue">Hello</text>_x000D_
  </g>_x000D_
</svg>
_x000D_
_x000D_
_x000D_

How to disable a ts rule for a specific line?

@ts-expect-error

TS 3.9 introduces a new magic comment. @ts-expect-error will:

  • have same functionality as @ts-ignore
  • trigger an error, if actually no compiler error has been suppressed (= indicates useless flag)
if (false) {
  // @ts-expect-error: Let's ignore a single compiler error like this unreachable code 
  console.log("hello"); // compiles
}

// If @ts-expect-error didn't suppress anything at all, we now get a nice warning 
let flag = true;
// ...
if (flag) {
  // @ts-expect-error
  // ^~~~~~~~~~~~~~~^ error: "Unused '@ts-expect-error' directive.(2578)"
  console.log("hello"); 
}

Alternatives

@ts-ignore and @ts-expect-error can be used for all sorts of compiler errors. For type issues (like in OP), I recommend one of the following alternatives due to narrower error suppression scope:

? Use any type

// type assertion for single expression
delete ($ as any).summernote.options.keyMap.pc.TAB;

// new variable assignment for multiple usages
const $$: any = $
delete $$.summernote.options.keyMap.pc.TAB;
delete $$.summernote.options.keyMap.mac.TAB;

? Augment JQueryStatic interface

// ./global.d.ts
interface JQueryStatic {
  summernote: any;
}

// ./main.ts
delete $.summernote.options.keyMap.pc.TAB; // works

In other cases, shorthand module declarations or module augmentations for modules with no/extendable types are handy utilities. A viable strategy is also to keep not migrated code in .js and use --allowJs with checkJs: false.

How to make an embedded video not autoplay

A couple of wires are crossed here. The various autoplay settings that you're working with only affect whether the SWF's root timeline starts out paused or not. So if your SWF had a timeline animation, or if it had an embedded video on the root timeline, then these settings would do what you're after.

However, the SWF you're working with almost certainly has only one frame on its timeline, so these settings won't affect playback at all. That one frame contains some flavor of video playback component, which contains ActionScript that controls how the video behaves. To get that player component to start of paused, you'll have to change the settings of the component itself.

Without knowing more about where the content came from it's hard to say more, but when one publishes from Flash, video player components normally include a parameter for whether to autoplay. If your SWF is being published by an application other than Flash (Captivate, I suppose, but I'm not up on that) then your best bet would be to check the settings for that app. Anyway it's not something you can control from the level of the HTML page. (Unless you were talking to the SWF from JavaScript, and for that to work the video component would have to be designed to allow it.)

How to select only date from a DATETIME field in MySQL?

SELECT DATE_FORMAT(NOW() - INTERVAL FLOOR(RAND() * 14) DAY,'%Y-%m-%d');

This one can be used to get date in 'yyyy-mm-dd' format.

Multi-statement Table Valued Function vs Inline Table Valued Function

Maybe in a very condensed way. ITVF ( inline TVF) : more if u are DB person, is kind of parameterized view, take a single SELECT st

MTVF ( Multi-statement TVF): Developer, creates and load a table variable.

Can you do greater than comparison on a date in a Rails 3 search?

Rails 6.1 added a new 'syntax' for comparison operators in where conditions, for example:

Post.where('id >': 9)
Post.where('id >=': 9)
Post.where('id <': 3)
Post.where('id <=': 3)

So your query can be rewritten as follows:

Note
  .where(user_id: current_user.id, notetype: p[:note_type], 'date >', p[:date])
  .order(date: :asc, created_at: :asc)

Here is a link to PR where you can find more examples.

Calling a stored procedure in Oracle with IN and OUT parameters

If you set the server output in ON mode before the entire code, it works, otherwise put_line() will not work. Try it!

The code is,

set serveroutput on;
CREATE OR REPLACE PROCEDURE PROC1(invoicenr IN NUMBER, amnt OUT NUMBER)
AS BEGIN
SELECT AMOUNT INTO amnt FROM INVOICE WHERE INVOICE_NR = invoicenr;
END;

And then call the function as it is:

DECLARE
amount NUMBER;
BEGIN
PROC1(1000001, amount);
dbms_output.put_line(amount);
END;

Set LIMIT with doctrine 2?

Your setMaxResults($limit) needs to be set on the object.

e.g.

$query_ids = $this->getEntityManager()
  ->createQuery(
    "SELECT e_.id
    FROM MuzichCoreBundle:Element e_
    WHERE [...]
    GROUP BY e_.id")
;
$query_ids->setMaxResults($limit);

How to set default value to the input[type="date"]

A possible solution:

document.getElementById("yourDatePicker").valueAsDate = new Date();

Using Moment.js:

var today = moment().format('YYYY-MM-DD');
document.getElementById("datePicker").value = today;

How to remove a class from elements in pure JavaScript?

elements is an array of DOM objects. You should do something like this

for (var i = 0; i < elements.length; i++) {
   elements[i].classList.remove('hover');
}

ie: enumerate the elements collection, and for each element inside the collection call the remove method

Sorting a set of values

From a comment:

I want to sort each set.

That's easy. For any set s (or anything else iterable), sorted(s) returns a list of the elements of s in sorted order:

>>> s = set(['0.000000000', '0.009518000', '10.277200999', '0.030810999', '0.018384000', '4.918560000'])
>>> sorted(s)
['0.000000000', '0.009518000', '0.018384000', '0.030810999', '10.277200999', '4.918560000']

Note that sorted is giving you a list, not a set. That's because the whole point of a set, both in mathematics and in almost every programming language,* is that it's not ordered: the sets {1, 2} and {2, 1} are the same set.


You probably don't really want to sort those elements as strings, but as numbers (so 4.918560000 will come before 10.277200999 rather than after).

The best solution is most likely to store the numbers as numbers rather than strings in the first place. But if not, you just need to use a key function:

>>> sorted(s, key=float)
['0.000000000', '0.009518000', '0.018384000', '0.030810999', '4.918560000', '10.277200999']

For more information, see the Sorting HOWTO in the official docs.


* See the comments for exceptions.

return in for loop or outside loop

Now someone told me that this is not very good programming because I use the return statement inside a loop and this would cause garbage collection to malfunction.

That's incorrect, and suggests you should treat other advice from that person with a degree of skepticism.

The mantra of "only have one return statement" (or more generally, only one exit point) is important in languages where you have to manage all resources yourself - that way you can make sure you put all your cleanup code in one place.

It's much less useful in Java: as soon as you know that you should return (and what the return value should be), just return. That way it's simpler to read - you don't have to take in any of the rest of the method to work out what else is going to happen (other than finally blocks).

Builder Pattern in Effective Java

You need to declare the Builder inner class as static.

Consult some documentation for both non-static inner classes and static inner classes.

Basically the non-static inner classes instances cannot exist without attached outer class instance.

What is the syntax of the enhanced for loop in Java?

  1. Enhanced For Loop (Java)
for (Object obj : list);
  1. Enhanced For Each in arraylist (Java)
ArrayList<Integer> list = new ArrayList<Integer>(); 
list.forEach((n) -> System.out.println(n)); 

How to sort a collection by date in MongoDB?

Sorting by date doesn't require anything special. Just sort by the desired date field of the collection.

Updated for the 1.4.28 node.js native driver, you can sort ascending on datefield using any of the following ways:

collection.find().sort({datefield: 1}).toArray(function(err, docs) {...});
collection.find().sort('datefield', 1).toArray(function(err, docs) {...});
collection.find().sort([['datefield', 1]]).toArray(function(err, docs) {...});
collection.find({}, {sort: {datefield: 1}}).toArray(function(err, docs) {...});
collection.find({}, {sort: [['datefield', 1]]}).toArray(function(err, docs) {...});

'asc' or 'ascending' can also be used in place of the 1.

To sort descending, use 'desc', 'descending', or -1 in place of the 1.

How Stuff and 'For Xml Path' work in SQL Server?

This article covers various ways of concatenating strings in SQL, including an improved version of your code which doesn't XML-encode the concatenated values.

SELECT ID, abc = STUFF
(
    (
        SELECT ',' + name
        FROM temp1 As T2
        -- You only want to combine rows for a single ID here:
        WHERE T2.ID = T1.ID
        ORDER BY name
        FOR XML PATH (''), TYPE
    ).value('.', 'varchar(max)')
, 1, 1, '')
FROM temp1 As T1
GROUP BY id

To understand what's happening, start with the inner query:

SELECT ',' + name
FROM temp1 As T2
WHERE T2.ID = 42 -- Pick a random ID from the table
ORDER BY name
FOR XML PATH (''), TYPE

Because you're specifying FOR XML, you'll get a single row containing an XML fragment representing all of the rows.

Because you haven't specified a column alias for the first column, each row would be wrapped in an XML element with the name specified in brackets after the FOR XML PATH. For example, if you had FOR XML PATH ('X'), you'd get an XML document that looked like:

<X>,aaa</X>
<X>,bbb</X>
...

But, since you haven't specified an element name, you just get a list of values:

,aaa,bbb,...

The .value('.', 'varchar(max)') simply retrieves the value from the resulting XML fragment, without XML-encoding any "special" characters. You now have a string that looks like:

',aaa,bbb,...'

The STUFF function then removes the leading comma, giving you a final result that looks like:

'aaa,bbb,...'

It looks quite confusing at first glance, but it does tend to perform quite well compared to some of the other options.

Android TabLayout Android Design

Add this to the module build.gradle:

implementation 'com.android.support.constraint:constraint-layout:1.1.3'

implementation 'com.android.support:design:28.0.0'

How do I properly force a Git push?

And if push --force doesn't work you can do push --delete. Look at 2nd line on this instance:

git reset --hard HEAD~3  # reset current branch to 3 commits ago
git push origin master --delete  # do a very very bad bad thing
git push origin master  # regular push

But beware...

Never ever go back on a public git history!

In other words:

  • Don't ever force push on a public repository.
  • Don't do this or anything that can break someone's pull.
  • Don't ever reset or rewrite history in a repo someone might have already pulled.

Of course there are exceptionally rare exceptions even to this rule, but in most cases it's not needed to do it and it will generate problems to everyone else.

Do a revert instead.

And always be careful with what you push to a public repo. Reverting:

git revert -n HEAD~3..HEAD  # prepare a new commit reverting last 3 commits
git commit -m "sorry - revert last 3 commits because I was not careful"
git push origin master  # regular push

In effect, both origin HEADs (from the revert and from the evil reset) will contain the same files.


edit to add updated info and more arguments around push --force

Consider pushing force with lease instead of push, but still prefer revert

Another problem push --force may bring is when someone push anything before you do, but after you've already fetched. If you push force your rebased version now you will replace work from others.

git push --force-with-lease introduced in the git 1.8.5 (thanks to @VonC comment on the question) tries to address this specific issue. Basically, it will bring an error and not push if the remote was modified since your latest fetch.

This is good if you're really sure a push --force is needed, but still want to prevent more problems. I'd go as far to say it should be the default push --force behaviour. But it's still far from being an excuse to force a push. People who fetched before your rebase will still have lots of troubles, which could be easily avoided if you had reverted instead.

And since we're talking about git --push instances...

Why would anyone want to force push?

@linquize brought a good push force example on the comments: sensitive data. You've wrongly leaked data that shouldn't be pushed. If you're fast enough, you can "fix"* it by forcing a push on top.

* The data will still be on the remote unless you also do a garbage collect, or clean it somehow. There is also the obvious potential for it to be spread by others who'd fetched it already, but you get the idea.

How to use performSelector:withObject:afterDelay: with primitive types in Cocoa?

I would always recomend that you use NSMutableArray as the object to pass on. This is because you can then pass several objects, like the button pressed and other values. NSNumber, NSInteger and NSString are just containers of some value. Make sure that when you get the object from the array that you refer to to a correct container type. You need to pass on NS containers. There you may test the value. Remember that containers use isEqual when values are compared.

#define DELAY_TIME 5

-(void)changePlayerGameOnes:(UIButton*)sender{
    NSNumber *nextPlayer = [NSNumber numberWithInt:[gdata.currentPlayer intValue]+1 ];
    NSMutableArray *array = [[NSMutableArray alloc]initWithObjects:sender, nil];
    [array addObject:nextPlayer];
    [self performSelector:@selector(next:) withObject:array afterDelay:DELAY_TIME];
}
-(void)next:(NSMutableArray*)nextPlayer{
    if(gdata != nil){ //if game choose next player
       [self nextPlayer:[nextPlayer objectAtIndex:1] button:[nextPlayer objectAtIndex:0]];
    }
}

Is the MIME type 'image/jpg' the same as 'image/jpeg'?

For those it might help, I use this list as a reference to define my content-type when I have to deal with images on my app.

It says that jpg extension can be declared with Content-type : image/jpeg

There isn't any image/jpg attribute for content-type.

How to test if list element exists?

A slight modified version of @salient.salamander , if one wants to check on full path, this can be used.

Element_Exists_Check = function( full_index_path ){
  tryCatch({
    len_element = length(full_index_path)
    exists_indicator = ifelse(len_element > 0, T, F)
      return(exists_indicator)
  }, error = function(e) {
    return(F)
  })
}