Programs & Examples On #Frustum

A frustum is a region of space delimited by a solid geometrical shape and two parallel planes cutting it, in particular the region of (virtual) space that is rendered on screen in computer graphics applications.

Twitter - How to embed native video from someone else's tweet into a New Tweet or a DM

I found a faster way of embedding:

  • Just copy the link.
  • Paste the link and remove the "?s=19" part and add "/video/1"
  • That's it.

HTML input type=file, get the image before submitting the form

Here is the complete example for previewing image before it gets upload.

HTML :

<html>
<head>
<link class="jsbin" href="http://ajax.googleapis.com/ajax/libs/jqueryui/1/themes/base/jquery-ui.css" rel="stylesheet" type="text/css" />
<script class="jsbin" src="http://ajax.googleapis.com/ajax/libs/jquery/1/jquery.min.js"></script>
<script class="jsbin" src="http://ajax.googleapis.com/ajax/libs/jqueryui/1.8.0/jquery-ui.min.js"></script>
<meta charset=utf-8 />
<title>JS Bin</title>
<!--[if IE]>
<script src="http://goo.gl/r57ze"></script>
<![endif]-->
</head>
<body>
<input type='file' onchange="readURL(this);" />
<img id="blah" src="#" alt="your image" />
</body>
</html>

JavaScript :

function readURL(input) {
  if (input.files && input.files[0]) {
    var reader = new FileReader();
    reader.onload = function (e) {
      $('#blah')
        .attr('src', e.target.result)
        .width(150)
        .height(200);
    };
    reader.readAsDataURL(input.files[0]);
  }
}

Convert array to JSON string in swift

You can try this.

func convertToJSONString(value: AnyObject) -> String? {
        if JSONSerialization.isValidJSONObject(value) {
            do{
                let data = try JSONSerialization.data(withJSONObject: value, options: [])
                if let string = NSString(data: data, encoding: String.Encoding.utf8.rawValue) {
                    return string as String
                }
            }catch{
            }
        }
        return nil
    }

Node.js Web Application examples/tutorials

I would suggest you check out the various tutorials that are coming out lately. My current fav is:

http://nodetuts.com/

Hope this helps.

Filter Extensions in HTML form upload

I use javascript to check file extension. Here is my code:

HTML

<input name="fileToUpload" type="file" onchange="check_file()" >

.. ..

javascript

function check_file(){
                str=document.getElementById('fileToUpload').value.toUpperCase();
        suffix=".JPG";
        suffix2=".JPEG";
        if(str.indexOf(suffix, str.length - suffix.length) == -1||
                       str.indexOf(suffix2, str.length - suffix2.length) == -1){
        alert('File type not allowed,\nAllowed file: *.jpg,*.jpeg');
            document.getElementById('fileToUpload').value='';
        }
    }

how to display progress while loading a url to webview in android?

You will have to over ride onPageStarted and onPageFinished callbacks

mWebView.setWebViewClient(new WebViewClient() {

        public void onPageStarted(WebView view, String url, Bitmap favicon) {
            if (progressBar!= null && progressBar.isShowing()) {
                progressBar.dismiss();
            }
            progressBar = ProgressDialog.show(WebViewActivity.this, "Application Name", "Loading...");
        }

        public boolean shouldOverrideUrlLoading(WebView view, String url) {
            view.loadUrl(url);

            return true;
        }

        public void onPageFinished(WebView view, String url) {
            if (progressBar.isShowing()) {
                progressBar.dismiss();
            }
        }

        public void onReceivedError(WebView view, int errorCode, String description, String failingUrl) {
            alertDialog.setTitle("Error");
            alertDialog.setMessage(description);
            alertDialog.setButton("OK", new DialogInterface.OnClickListener() {
                public void onClick(DialogInterface dialog, int which) {
                    return;
                }
            });
            alertDialog.show();
        }
    });

Set max-height on inner div so scroll bars appear, but not on parent div

It might be easier to use JavaScript or jquery for this. Assuming that the height of the header and the footer is 200 then the code will be:

function SetHeight(){
    var h = $(window).height();
    $("#inner-right").height(h-200);    
}

$(document).ready(SetHeight);
$(window).resize(SetHeight);

Range of values in C Int and Long 32 - 64 bits

It is better to include stdlib.h. Since without stdlibg it takes long as long

How to unmount a busy device

Make sure that you aren't still in the mounted device when you are trying to umount.

Javascript return number of days,hours,minutes,seconds between two dates

Short and flexible with support for negative values, although by using two comma expressions :)

function timeUnitsBetween(startDate, endDate) {
  let delta = Math.abs(endDate - startDate) / 1000;
  const isNegative = startDate > endDate ? -1 : 1;
  return [
    ['days', 24 * 60 * 60],
    ['hours', 60 * 60],
    ['minutes', 60],
    ['seconds', 1]
  ].reduce((acc, [key, value]) => (acc[key] = Math.floor(delta / value) * isNegative, delta -= acc[key] * isNegative * value, acc), {});
}

Example:

timeUnitsBetween(new Date("2019-02-11T02:12:03+00:00"), new Date("2019-02-11T01:00:00+00:00"));
// { days: -0, hours: -1, minutes: -12, seconds: -3 }

Inspired by RienNeVaPlu?s solution.

Executing JavaScript after X seconds

setTimeout will help you to execute any JavaScript code based on the time you set.

Syntax

setTimeout(code, millisec, lang)

Usage,

setTimeout("function1()", 1000);

For more details, see http://www.w3schools.com/jsref/met_win_settimeout.asp

Adding days to a date in Java

Simple, without any other API:

To add 8 days:

Date today=new Date();
long ltime=today.getTime()+8*24*60*60*1000;
Date today8=new Date(ltime);

Ellipsis for overflow text in dropdown boxes

You can use this jQuery function instead of plus Bootstrap tooltip

function DDLSToolTipping(ddlsArray) {
    $(ddlsArray).each(function (index, ddl) {
        DDLToolTipping(ddl)
    });
}

function DDLToolTipping(ddlID, maxLength, allowDots) {
    if (maxLength == null) { maxLength = 12 }
    if (allowDots == null) { allowDots = true }

    var selectedOption = $(ddlID).find('option:selected').text();

    if (selectedOption.length > maxLength) {
        $(ddlID).attr('data-toggle', "tooltip")
                .attr('title', selectedOption);

        if (allowDots) {
            $(ddlID).prev('sup').remove();
            $(ddlID).before(
            "<sup style='font-size: 9.5pt;position: relative;top: -1px;left: -17px;z-index: 1000;background-color: #f7f7f7;border-radius: 229px;font-weight: bold;color: #666;'>...</sup>"
               )
        }
    }

    else if ($(ddlID).attr('title') != null) {
        $(ddlID).removeAttr('data-toggle')
                .removeAttr('title');
    }
}

How to target only IE (any version) within a stylesheet?

When using SASS I use the following 2 @media queries to target IE 6-10 & EDGE.

@media screen\9
    @import ie_styles
@media screen\0
    @import ie_styles

http://keithclark.co.uk/articles/moving-ie-specific-css-into-media-blocks/

Edit

I also target later versions of EDGE using @support queries (add as many as you need)

@supports (-ms-ime-align:auto)
    @import ie_styles
@supports (-ms-accelerator:auto)
    @import ie_styles

https://jeffclayton.wordpress.com/2015/04/07/css-hacks-for-windows-10-and-spartan-browser-preview/

Android: android.content.res.Resources$NotFoundException: String resource ID #0x5

Another scenario that can cause this exception is with DataBinding, that is when you use something like this in your layout

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

    <data>

        <variable
            name="model"
            type="point.to.your.model"/>
    </data>
    <TextView
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:text="@{model.someIntegerVariable}"/>

</layout>

Notice that the variable I'm using is an Integer and I'm assigning it to the text field of the TextView. Since the TextView already has a method with signature of setText(int) it will use this method instead of using the setText(String) and cast the value. Thus the TextView thinks of your input number as a resource value which obviously is not valid.

Solution is to cast your int value to string like this

android:text="@{String.valueOf(model.someIntegerVariable)}"

Oracle Date datatype, transformed to 'YYYY-MM-DD HH24:MI:SS TMZ' through SQL

There's a bit of confusion in your question:

  • a Date datatype doesn't save the time zone component. This piece of information is truncated and lost forever when you insert a TIMESTAMP WITH TIME ZONE into a Date.
  • When you want to display a date, either on screen or to send it to another system via a character API (XML, file...), you use the TO_CHAR function. In Oracle, a Date has no format: it is a point in time.
  • Reciprocally, you would use TO_TIMESTAMP_TZ to convert a VARCHAR2 to a TIMESTAMP, but this won't convert a Date to a TIMESTAMP.
  • You use FROM_TZ to add the time zone information to a TIMESTAMP (or a Date).
  • In Oracle, CST is a time zone but CDT is not. CDT is a daylight saving information.
  • To complicate things further, CST/CDT (-05:00) and CST/CST (-06:00) will have different values obviously, but the time zone CST will inherit the daylight saving information depending upon the date by default.

So your conversion may not be as simple as it looks.

Assuming that you want to convert a Date d that you know is valid at time zone CST/CST to the equivalent at time zone CST/CDT, you would use:

SQL> SELECT from_tz(d, '-06:00') initial_ts,
  2         from_tz(d, '-06:00') at time zone ('-05:00') converted_ts
  3    FROM (SELECT cast(to_date('2012-10-09 01:10:21',
  4                              'yyyy-mm-dd hh24:mi:ss') as timestamp) d
  5            FROM dual);

INITIAL_TS                      CONVERTED_TS
------------------------------- -------------------------------
09/10/12 01:10:21,000000 -06:00 09/10/12 02:10:21,000000 -05:00

My default timestamp format has been used here. I can specify a format explicitely:

SQL> SELECT to_char(from_tz(d, '-06:00'),'yyyy-mm-dd hh24:mi:ss TZR') initial_ts,
  2         to_char(from_tz(d, '-06:00') at time zone ('-05:00'),
  3                 'yyyy-mm-dd hh24:mi:ss TZR') converted_ts
  4    FROM (SELECT cast(to_date('2012-10-09 01:10:21',
  5                              'yyyy-mm-dd hh24:mi:ss') as timestamp) d
  6            FROM dual);

INITIAL_TS                      CONVERTED_TS
------------------------------- -------------------------------
2012-10-09 01:10:21 -06:00      2012-10-09 02:10:21 -05:00

how to access iFrame parent page using jquery?

how to access iFrame parent page using jquery

window.parent.document.

jQuery is a library on top of JavaScript, not a complete replacement for it. You don't have to replace every last JavaScript expression with something involving $.

How do I execute a *.dll file

You can't "execute" a DLL. You can execute functions within the DLL, as explained in the other answers. Although .EXE files and .DLL files are essentially identical in terms of format, the distinguishing feature of an .EXE is that it contains a designated "entry point" to go and do the thing the EXE was created to do. DLLs actually have something similar, but the purpose of the "dll main" is just to perform initialization and not fulfill the primary purpose of the DLL; that is for the (presumably) various other functions it contains.

You can execute any of the functions exported by a DLL, assuming you know which one you want to execute; an EXE may contain a whole lot of functions, but one and only one is specially designated to be executed simply by "running" it.

Android ImageView setImageResource in code

One easy way to map that country name that you have to an int to be used in the setImageResource method is:

int id = getResources().getIdentifier(lowerCountryCode, "drawable", getPackageName());
setImageResource(id);

But you should really try to use different folders resources for the countries that you want to support.

How does Google calculate my location on a desktop?

According to Google Maps' own help:
If your browser cannot show images, get a new one!

UIView Infinite 360 degree rotation animation?

Swift :

func runSpinAnimationOnView(view:UIView , duration:Float, rotations:Double, repeatt:Float ) ->()
    {
        let rotationAnimation=CABasicAnimation();

        rotationAnimation.keyPath="transform.rotation.z"

        let toValue = M_PI * 2.0 * rotations ;


        // passing it a float
        let someInterval = CFTimeInterval(duration)

        rotationAnimation.toValue=toValue;
        rotationAnimation.duration=someInterval;
        rotationAnimation.cumulative=true;
        rotationAnimation.repeatCount=repeatt;
        view.layer.addAnimation(rotationAnimation, forKey: "rotationAnimation")


    }

Iterating through struct fieldnames in MATLAB

You have to use curly braces ({}) to access fields, since the fieldnames function returns a cell array of strings:

for i = 1:numel(fields)
  teststruct.(fields{i})
end

Using parentheses to access data in your cell array will just return another cell array, which is displayed differently from a character array:

>> fields(1)  % Get the first cell of the cell array

ans = 

    'a'       % This is how the 1-element cell array is displayed

>> fields{1}  % Get the contents of the first cell of the cell array

ans =

a             % This is how the single character is displayed

how to get date of yesterday using php?

there you go

date('d.m.Y',strtotime("-1 days"));

this will work also if month change

Pass row number as variable in excel sheet

Assuming your row number is in B1, you can use INDIRECT:

=INDIRECT("A" & B1)

This takes a cell reference as a string (in this case, the concatenation of A and the value of B1 - 5), and returns the value at that cell.

What is uintptr_t data type

uintptr_t is an unsigned integer type that is capable of storing a data pointer. Which typically means that it's the same size as a pointer.

It is optionally defined in C++11 and later standards.

A common reason to want an integer type that can hold an architecture's pointer type is to perform integer-specific operations on a pointer, or to obscure the type of a pointer by providing it as an integer "handle".

What __init__ and self do in Python?

Python __init__ and self what do they do?

What does self do? What is it meant to be? Is it mandatory?

What does the __init__ method do? Why is it necessary? (etc.)

The example given is not correct, so let me create a correct example based on it:

class SomeObject(object):

    def __init__(self, blah):
        self.blah = blah

    def method(self):
        return self.blah 

When we create an instance of the object, the __init__ is called to customize the object after it has been created. That is, when we call SomeObject with 'blah' below (which could be anything), it gets passed to the __init__ function as the argument, blah:

an_object = SomeObject('blah')

The self argument is the instance of SomeObject that will be assigned to an_object.

Later, we might want to call a method on this object:

an_object.method()

Doing the dotted lookup, that is, an_object.method, binds the instance to an instance of the function, and the method (as called above) is now a "bound" method - which means we do not need to explicitly pass the instance to the method call.

The method call gets the instance because it was bound on the dotted lookup, and when called, then executes whatever code it was programmed to perform.

The implicitly passed self argument is called self by convention. We could use any other legal Python name, but you will likely get tarred and feathered by other Python programmers if you change it to something else.

__init__ is a special method, documented in the Python datamodel documentation. It is called immediately after the instance is created (usually via __new__ - although __new__ is not required unless you are subclassing an immutable datatype).

Setting ANDROID_HOME enviromental variable on Mac OS X

To set ANDROID_HOME, variable, you need to know how you installed android dev setup.

If you don't know you can check if the following paths exist in your machine. Add the following to .bashrc, .zshrc, or .profile depending on what you use

If you installed with homebrew,

export ANDROID_HOME=/usr/local/opt/android-sdk

Check if this path exists:

If you installed android studio following the website,

export ANDROID_HOME=~/Library/Android/sdk

Finally add it to path:

export PATH=$PATH:$ANDROID_HOME/tools:$ANDROID_HOME/platform-tools

If you're too lazy to open an editor do this:

echo "export ANDROID_HOME=~/Library/Android/sdk" >> ~/.bashrc
echo "export PATH=$PATH:$ANDROID_HOME/tools:$ANDROID_HOME/platform-tools" >> ~/.bashrc

How do I force git pull to overwrite everything on every pull?

To pull a copy of the branch and force overwrite of local files from the origin use:

git reset --hard origin/current_branch

All current work will be lost and it will then be the same as the origin branch

How do I set path while saving a cookie value in JavaScript?

document.cookie = "cookiename=Some Name; path=/";

This will do

How to do a SUM() inside a case statement in SQL server

The error you posted can happen when you're using a clause in the GROUP BY statement without including it in the select.

Example

This one works!

     SELECT t.device,
            SUM(case when transits.direction = 1 then 1 else 0 end) ,
            SUM(case when transits.direction = 0 then 1 else 0 end) from t1 t 
            where t.device in ('A','B') group by t.device

This one not (omitted t.device from the select)

     SELECT 
            SUM(case when transits.direction = 1 then 1 else 0 end) ,
            SUM(case when transits.direction = 0 then 1 else 0 end) from t1 t 
            where t.device in ('A','B') group by t.device

This will produce your error complaining that I'm grouping for something that is not included in the select

Please, provide all the query to get more support.

Intel X86 emulator accelerator (HAXM installer) VT/NX not enabled

Version 1.1.1 is the correct version for Yosemite. You need to download this directly from intel's site: https://software.intel.com/en-us/android/articles/intel-hardware-accelerated-execution-manager.

The one downloaded by SDK Manager is the older version (1.1.0). If you still want to run with version 1.1.0 - refer to the solution here - http://www.csell.net/2014/09/03/VTNX_Not_Enabled/

How can I handle the warning of file_get_contents() function in PHP?

You can also set your error handler as an anonymous function that calls an Exception and use a try / catch on that exception.

set_error_handler(
    function ($severity, $message, $file, $line) {
        throw new ErrorException($message, $severity, $severity, $file, $line);
    }
);

try {
    file_get_contents('www.google.com');
}
catch (Exception $e) {
    echo $e->getMessage();
}

restore_error_handler();

Seems like a lot of code to catch one little error, but if you're using exceptions throughout your app, you would only need to do this once, way at the top (in an included config file, for instance), and it will convert all your errors to Exceptions throughout.

Default argument values in JavaScript functions

I have never seen it done that way in JavaScript. If you want a function with optional parameters that get assigned default values if the parameters are omitted, here's a way to do it:

 function(a, b) {
      if (typeof a == "undefined") {
        a = 10;
      }

      if (typeof b == "undefined") {
        a = 20;
      }

      alert("a: " + a + " b: " + b);
    }

Return JSON for ResponseEntity<String>

public ResponseEntity<?> ApiCall(@PathVariable(name = "id") long id) {
    JSONObject resp = new JSONObject();
    resp.put("status", 0);
    resp.put("id", id);

    return new ResponseEntity<String>(resp.toString(), HttpStatus.CREATED);
}

What is the difference between getText() and getAttribute() in Selenium WebDriver?

getAttribute() -> It fetches the text that contains one of any attribute in the HTML tag. Suppose there is an HTML tag like

<input name="Name Locator" value="selenium">Hello</input>

Now getAttribute() fetches the data of the attribute of 'value', which is "Selenium".

Returns:

The attribute's current value or null if the value is not set.

driver.findElement(By.name("Name Locator")).getAttribute("value")  //

The field value is retrieved by the getAttribute("value") Selenium WebDriver predefined method and assigned to the String object.

getText() -> delivers the innerText of a WebElement. Get the visible (i.e. not hidden by CSS) innerText of this element, including sub-elements, without any leading or trailing whitespace.

Returns:

The innerText of this element.

driver.findElement(By.name("Name Locator")).getText();

'Hello' will appear

An invalid form control with name='' is not focusable

Adding a novalidate attribute to the form will help:

<form name="myform" novalidate>

How to use HTTP GET in PowerShell?

In PowerShell v3, have a look at the Invoke-WebRequest and Invoke-RestMethod e.g.:

$msg = Read-Host -Prompt "Enter message"
$encmsg = [System.Web.HttpUtility]::UrlEncode($msg)
Invoke-WebRequest -Uri "http://smsserver/SNSManager/msgSend.jsp?uid&to=smartsms:*+001XXXXXX&msg=$encmsg&encoding=windows-1255"

How to import local packages in go?

If you are using Go 1.5 above, you can try to use vendoring feature. It allows you to put your local package under vendor folder and import it with shorter path. In your case, you can put your common and routers folder inside vendor folder so it would be like

myapp/
--vendor/
----common/
----routers/
------middleware/
--main.go

and import it like this

import (
    "common"
    "routers"
    "routers/middleware"
)

This will work because Go will try to lookup your package starting at your project’s vendor directory (if it has at least one .go file) instead of $GOPATH/src.

FYI: You can do more with vendor, because this feature allows you to put "all your dependency’s code" for a package inside your own project's directory so it will be able to always get the same dependencies versions for all builds. It's like npm or pip in python, but you need to manually copy your dependencies to you project, or if you want to make it easy, try to look govendor by Daniel Theophanes

For more learning about this feature, try to look up here

Understanding and Using Vendor Folder by Daniel Theophanes

Understanding Go Dependency Management by Lucas Fernandes da Costa

I hope you or someone else find it helpfully

Project with path ':mypath' could not be found in root project 'myproject'

I got similar error after deleting a subproject, removed

"*compile project(path: ':MySubProject', configuration: 'android-endpoints')*"

in build.gradle (dependencies) under Gradle Scripts

How can I check if two segments intersect?

Here is C code to check if two points are on the opposite sides of the line segment. Using this code you can check if two segments intersect as well.

// true if points p1, p2 lie on the opposite sides of segment s1--s2
bool oppositeSide (Point2f s1, Point2f s2, Point2f p1, Point2f p2) {

//calculate normal to the segment
Point2f vec = s1-s2;
Point2f normal(vec.y, -vec.x); // no need to normalize

// vectors to the points
Point2f v1 = p1-s1;
Point2f v2 = p2-s1;

// compare signs of the projections of v1, v2 onto the normal
float proj1 = v1.dot(normal);
float proj2 = v2.dot(normal);
if (proj1==0 || proj2==0)
        cout<<"collinear points"<<endl;

return(SIGN(proj1) != SIGN(proj2));

}

Finding the layers and layer sizes for each Docker image

You can first find the image ID using:

$ docker images -a

Then find the image's layers and their sizes:

$ docker history --no-trunc <Image ID>

Note: I'm using Docker version 1.13.1

$ docker -v
Docker version 1.13.1, build 092cba3

How to make a cross-module variable?

I wondered if it would be possible to avoid some of the disadvantages of using global variables (see e.g. http://wiki.c2.com/?GlobalVariablesAreBad) by using a class namespace rather than a global/module namespace to pass values of variables. The following code indicates that the two methods are essentially identical. There is a slight advantage in using class namespaces as explained below.

The following code fragments also show that attributes or variables may be dynamically created and deleted in both global/module namespaces and class namespaces.

wall.py

# Note no definition of global variables

class router:
    """ Empty class """

I call this module 'wall' since it is used to bounce variables off of. It will act as a space to temporarily define global variables and class-wide attributes of the empty class 'router'.

source.py

import wall
def sourcefn():
    msg = 'Hello world!'
    wall.msg = msg
    wall.router.msg = msg

This module imports wall and defines a single function sourcefn which defines a message and emits it by two different mechanisms, one via globals and one via the router function. Note that the variables wall.msg and wall.router.message are defined here for the first time in their respective namespaces.

dest.py

import wall
def destfn():

    if hasattr(wall, 'msg'):
        print 'global: ' + wall.msg
        del wall.msg
    else:
        print 'global: ' + 'no message'

    if hasattr(wall.router, 'msg'):
        print 'router: ' + wall.router.msg
        del wall.router.msg
    else:
        print 'router: ' + 'no message'

This module defines a function destfn which uses the two different mechanisms to receive the messages emitted by source. It allows for the possibility that the variable 'msg' may not exist. destfn also deletes the variables once they have been displayed.

main.py

import source, dest

source.sourcefn()

dest.destfn() # variables deleted after this call
dest.destfn()

This module calls the previously defined functions in sequence. After the first call to dest.destfn the variables wall.msg and wall.router.msg no longer exist.

The output from the program is:

global: Hello world!
router: Hello world!
global: no message
router: no message

The above code fragments show that the module/global and the class/class variable mechanisms are essentially identical.

If a lot of variables are to be shared, namespace pollution can be managed either by using several wall-type modules, e.g. wall1, wall2 etc. or by defining several router-type classes in a single file. The latter is slightly tidier, so perhaps represents a marginal advantage for use of the class-variable mechanism.

How do I change the background color with JavaScript?

Modify the JavaScript property document.body.style.background.

For example:

function changeBackground(color) {
   document.body.style.background = color;
}

window.addEventListener("load",function() { changeBackground('red') });

Note: this does depend a bit on how your page is put together, for example if you're using a DIV container with a different background colour you will need to modify the background colour of that instead of the document body.

JPA and Hibernate - Criteria vs. JPQL or HQL

I mostly prefer Criteria Queries for dynamic queries. For example it is much easier to add some ordering dynamically or leave some parts (e.g. restrictions) out depending on some parameter.

On the other hand I'm using HQL for static and complex queries, because it's much easier to understand/read HQL. Also, HQL is a bit more powerful, I think, e.g. for different join types.

error: resource android:attr/fontVariationSettings not found

For those that must keep compileSdkVersion 27 and are unable to upgrade to androidx yet, you must not upgrade to (or over) the versions of dependencies in the following links. These links are where the breaking change was introduced. You must find an earlier version that doesn't use androidx.

https://firebase.google.com/support/release-notes/android#update_-_june_17_2019

https://developers.google.com/android/guides/releases#june_17_2019

For instance, the following are compatible with compileSdkVersion 27:

dependencies {
    implementation 'com.android.support:appcompat-v7:27.1.1'
    implementation 'com.android.support:support-v4:27.1.1'
    implementation 'com.google.android.gms:play-services-maps:16.1.0'
    implementation 'com.google.android.gms:play-services-location:16.0.0'
    implementation 'com.google.firebase:firebase-core:16.0.9'
    implementation 'com.google.firebase:firebase-messaging:18.0.0'
}

The following will break with compileSdkVersion 27 and are only compatible with compileSdkVersion 28:

dependencies {
    implementation 'com.android.support:appcompat-v7:28.0.0'
    implementation 'com.android.support:support-v4:28.0.0'
    implementation 'com.google.android.gms:play-services-maps:17.0.0'
    implementation 'com.google.android.gms:play-services-location:17.0.0'
    implementation 'com.google.firebase:firebase-core:17.0.0'
    implementation 'com.google.firebase:firebase-messaging:19.0.0'
}

How to Validate on Max File Size in Laravel?

According to the documentation:

$validator = Validator::make($request->all(), [
    'file' => 'max:500000',
]);

The value is in kilobytes. I.e. max:10240 = max 10 MB.

std::vector versus std::array in C++

If you are considering using multidimensional arrays, then there is one additional difference between std::array and std::vector. A multidimensional std::array will have the elements packed in memory in all dimensions, just as a c style array is. A multidimensional std::vector will not be packed in all dimensions.

Given the following declarations:

int cConc[3][5];
std::array<std::array<int, 5>, 3> aConc;
int **ptrConc;      // initialized to [3][5] via new and destructed via delete
std::vector<std::vector<int>> vConc;    // initialized to [3][5]

A pointer to the first element in the c-style array (cConc) or the std::array (aConc) can be iterated through the entire array by adding 1 to each preceding element. They are tightly packed.

A pointer to the first element in the vector array (vConc) or the pointer array (ptrConc) can only be iterated through the first 5 (in this case) elements, and then there are 12 bytes (on my system) of overhead for the next vector.

This means that a std::vector> array initialized as a [3][1000] array will be much smaller in memory than one initialized as a [1000][3] array, and both will be larger in memory than a std:array allocated either way.

This also means that you can't simply pass a multidimensional vector (or pointer) array to, say, openGL without accounting for the memory overhead, but you can naively pass a multidimensional std::array to openGL and have it work out.

What is the '.well' equivalent class in Bootstrap 4

None of the answers seemed to work well with buttons. Bootstrap v4.1.1

<div class="card bg-light">
    <div class="card-body">
        <button type="submit" class="btn btn-primary">
            Save
        </button>
        <a href="/" class="btn btn-secondary">
            Cancel
        </a>
    </div>
</div>

How to replace all double quotes to single quotes using jquery?

Use double quote to enclose the quote or escape it.

newTemp = mystring.replace(/"/g, "'");

or

newTemp = mystring.replace(/"/g, '\'');

Java Constructor Inheritance

Suppose constructors were inherited... then because every class eventually derives from Object, every class would end up with a parameterless constructor. That's a bad idea. What exactly would you expect:

FileInputStream stream = new FileInputStream();

to do?

Now potentially there should be a way of easily creating the "pass-through" constructors which are fairly common, but I don't think it should be the default. The parameters needed to construct a subclass are often different from those required by the superclass.

How do I fix MSB3073 error in my post-build event?

If the problem still persists even after putting the after build in the correct project try using "copy" instead of xcopy. This worked for me.

Passing a method parameter using Task.Factory.StartNew

For passing a single integer I agree with Reed Copsey's answer. If in the future you are going to pass more complicated constucts I personally like to pass all my variables as an Anonymous Type. It will look something like this:

foreach(int id in myIdsToCheck)
{
    Task.Factory.StartNew( (Object obj) => 
        {
           var data = (dynamic)obj;
           CheckFiles(data.id, theBlockingCollection,
               cancelCheckFile.Token, 
               TaskCreationOptions.LongRunning, 
               TaskScheduler.Default);
        }, new { id = id }); // Parameter value
}

You can learn more about it in my blog

How to delete files recursively from an S3 bucket

Best way is to use lifecycle rule to delete whole bucket contents. Programmatically you can use following code (PHP) to PUT lifecycle rule.

$expiration = array('Date' => date('U', strtotime('GMT midnight')));
$result = $s3->putBucketLifecycle(array(
            'Bucket' => 'bucket-name',
            'Rules' => array(
                array(
                    'Expiration' => $expiration,
                    'ID' => 'rule-name',
                    'Prefix' => '',
                    'Status' => 'Enabled',
                ),
            ),
        ));

In above case all the objects will be deleted starting Date - "Today GMT midnight".

You can also specify Days as follows. But with Days it will wait for at least 24 hrs (1 day is minimum) to start deleting the bucket contents.

$expiration = array('Days' => 1);

A keyboard shortcut to comment/uncomment the select text in Android Studio

From menu, Code -> Comment with Line Commment. So simple. enter image description here

Or, alternatively, add a shortcut as the following: enter image description here

enter image description here

Hashcode and Equals for Hashset

  1. There's no need to call equals if hashCode differs.
  2. There's no need to call hashCode if (obj1 == obj2).
  3. There's no need for hashCode and/or equals just to iterate - you're not comparing objects
  4. When needed to distinguish in between objects.

Why am I getting a FileNotFoundError?

You might need to change your path by:

import os
path=os.chdir(str('Here should be the path to your file')) #This command changes directory

This is what worked for me at least! Hope it works for you too!

How to save a git commit message from windows cmd?

I believe the REAL answer to this question is an explanation as to how you configure what editor to use by default, if you are not comfortable with Vim.

This is how to configure Notepad for example, useful in Windows:

git config --global core.editor "notepad"

Gedit, more Linux friendly:

git config --global core.editor "gedit"

You can read the current configuration like this:

git config core.editor

MSVCP120d.dll missing

Alternate approach : without installation of Redistributable package.

Check out in some github for the relevant dll, some people upload the reference dll for their application dependency.

you can download and use them in your project , I have used and run them successfully.

example : https://github.com/Emotiv/community-sdk/find/master

Cell spacing in UICollectionView

I'm using monotouch, so the names and code will be a bit different, but you can do this by making sure that the width of the collectionview equals (x * cell width) + (x-1) * MinimumSpacing with x = amount of cells per row.

Just do following steps based on your MinimumInteritemSpacing and the Width of the Cell

1) We calculate amount of items per row based on cell size + current insets + minimum spacing

float currentTotalWidth = CollectionView.Frame.Width - Layout.SectionInset.Left - Layout.SectionInset.Right (Layout = flowlayout)
int amountOfCellsPerRow = (currentTotalWidth + MinimumSpacing) / (cell width + MinimumSpacing)

2) Now you have all info to calculate the expected width for the collection view

float totalWidth =(amountOfCellsPerRow * cell width) + (amountOfCellsPerRow-1) * MinimumSpacing

3) So the difference between the current width and the expected width is

float difference = currentTotalWidth - totalWidth;

4) Now adjust the insets (in this example we add it to the right, so the left position of the collectionview stays the same

Layout.SectionInset.Right = Layout.SectionInset.Right + difference;

Sieve of Eratosthenes - Finding Primes Python

def eratosthenes(n):
    multiples = []
    for i in range(2, n+1):
        if i not in multiples:
            print (i)
            for j in range(i*i, n+1, i):
                multiples.append(j)

eratosthenes(100)

The use of Swift 3 @objc inference in Swift 4 mode is deprecated?

- What is @objc inference? What is going on?

In Swift 3, the compiler infers @objc in a number of places so you wouldn't have to. In other words, it makes sure to add @objc for you!

In Swift 4, the compiler no longer does this (as much). You now must add @objc explicitly.

By default, if you have a pre-Swift 4 project, you will get warnings about this. In a Swift 4 project, you will get build errors. This is controlled via the SWIFT_SWIFT3_OBJC_INFERENCE build setting. In a pre-Swift 4 project this is set to On. I would recommend to set this to Default (or Off), which is now the default option on a new project.

It will take some time to convert everything, but since it's the default for Swift 4, it's worth doing it.

- How do I stop the compiler warnings/errors?

There are two ways to go about converting your code so the compiler doesn't complain.

One is to use @objc on each function or variable that needs to be exposed to the Objective-C runtime:

@objc func foo() {

}

The other is to use @objcMembers by a Class declaration. This makes sure to automatically add @objc to ALL the functions and variables in the class. This is the easy way, but it has a cost, for example, it can increase the size of your application by exposing functions that did not need to be exposed.

@objcMembers class Test {

}

- What is @objc and why is it necessary?

If you introduce new methods or variables to a Swift class, marking them as @objc exposes them to the Objective-C runtime. This is necessary when you have Objective-C code that uses your Swift class, or, if you are using Objective-C-type features like Selectors. For example, the target-action pattern: button.addTarget(self, action:#selector(didPressButton), for:.touchUpInside)

- Why would I not mark everything @objc?

There are negatives that come with marking something as @objc:

  • Increased application binary size
  • No function overloading

Please keep in mind that this is a very high-level summary and that it is more complicated than I wrote. I would recommend reading the actual proposal for more information.

Sources:

Leaflet - How to find existing markers, and delete markers?

You can also push markers into an array. See code example, this works for me:

/*create array:*/
var marker = new Array();

/*Some Coordinates (here simulating somehow json string)*/
var items = [{"lat":"51.000","lon":"13.000"},{"lat":"52.000","lon":"13.010"},{"lat":"52.000","lon":"13.020"}];

/*pushing items into array each by each and then add markers*/
function itemWrap() {
for(i=0;i<items.length;i++){
    var LamMarker = new L.marker([items[i].lat, items[i].lon]);
    marker.push(LamMarker);
    map.addLayer(marker[i]);
    }
}

/*Going through these marker-items again removing them*/
function markerDelAgain() {
for(i=0;i<marker.length;i++) {
    map.removeLayer(marker[i]);
    }  
}

Converting double to string with N decimals, dot as decimal separator, and no thousand separator

It's really easy to specify your own decimal separator. Just took me about 2 hours to figure it out :D. You see that you were using the current ou other culture that you specify right? Well, the only thing the parser needs is an IFormatProvider. If you give it the CultureInfo.CurrentCulture.NumberFormat as a formatter, it will format the double according to your current culture's NumberDecimalSeparator. What I did was just to create a new instance of the NumberFormatInfo class and set it's NumberDecimalSeparator property to whichever separator string I wanted. Complete code below:

double value = 2.3d;
NumberFormatInfo nfi = new NumberFormatInfo();
nfi.NumberDecimalSeparator = "-";
string x = value.ToString(nfi);

The result? "2-3"

Which is faster: Stack allocation or Heap allocation

Honestly, it's trivial to write a program to compare the performance:

#include <ctime>
#include <iostream>

namespace {
    class empty { }; // even empty classes take up 1 byte of space, minimum
}

int main()
{
    std::clock_t start = std::clock();
    for (int i = 0; i < 100000; ++i)
        empty e;
    std::clock_t duration = std::clock() - start;
    std::cout << "stack allocation took " << duration << " clock ticks\n";
    start = std::clock();
    for (int i = 0; i < 100000; ++i) {
        empty* e = new empty;
        delete e;
    };
    duration = std::clock() - start;
    std::cout << "heap allocation took " << duration << " clock ticks\n";
}

It's said that a foolish consistency is the hobgoblin of little minds. Apparently optimizing compilers are the hobgoblins of many programmers' minds. This discussion used to be at the bottom of the answer, but people apparently can't be bothered to read that far, so I'm moving it up here to avoid getting questions that I've already answered.

An optimizing compiler may notice that this code does nothing, and may optimize it all away. It is the optimizer's job to do stuff like that, and fighting the optimizer is a fool's errand.

I would recommend compiling this code with optimization turned off because there is no good way to fool every optimizer currently in use or that will be in use in the future.

Anybody who turns the optimizer on and then complains about fighting it should be subject to public ridicule.

If I cared about nanosecond precision I wouldn't use std::clock(). If I wanted to publish the results as a doctoral thesis I would make a bigger deal about this, and I would probably compare GCC, Tendra/Ten15, LLVM, Watcom, Borland, Visual C++, Digital Mars, ICC and other compilers. As it is, heap allocation takes hundreds of times longer than stack allocation, and I don't see anything useful about investigating the question any further.

The optimizer has a mission to get rid of the code I'm testing. I don't see any reason to tell the optimizer to run and then try to fool the optimizer into not actually optimizing. But if I saw value in doing that, I would do one or more of the following:

  1. Add a data member to empty, and access that data member in the loop; but if I only ever read from the data member the optimizer can do constant folding and remove the loop; if I only ever write to the data member, the optimizer may skip all but the very last iteration of the loop. Additionally, the question wasn't "stack allocation and data access vs. heap allocation and data access."

  2. Declare e volatile, but volatile is often compiled incorrectly (PDF).

  3. Take the address of e inside the loop (and maybe assign it to a variable that is declared extern and defined in another file). But even in this case, the compiler may notice that -- on the stack at least -- e will always be allocated at the same memory address, and then do constant folding like in (1) above. I get all iterations of the loop, but the object is never actually allocated.

Beyond the obvious, this test is flawed in that it measures both allocation and deallocation, and the original question didn't ask about deallocation. Of course variables allocated on the stack are automatically deallocated at the end of their scope, so not calling delete would (1) skew the numbers (stack deallocation is included in the numbers about stack allocation, so it's only fair to measure heap deallocation) and (2) cause a pretty bad memory leak, unless we keep a reference to the new pointer and call delete after we've got our time measurement.

On my machine, using g++ 3.4.4 on Windows, I get "0 clock ticks" for both stack and heap allocation for anything less than 100000 allocations, and even then I get "0 clock ticks" for stack allocation and "15 clock ticks" for heap allocation. When I measure 10,000,000 allocations, stack allocation takes 31 clock ticks and heap allocation takes 1562 clock ticks.


Yes, an optimizing compiler may elide creating the empty objects. If I understand correctly, it may even elide the whole first loop. When I bumped up the iterations to 10,000,000 stack allocation took 31 clock ticks and heap allocation took 1562 clock ticks. I think it's safe to say that without telling g++ to optimize the executable, g++ did not elide the constructors.


In the years since I wrote this, the preference on Stack Overflow has been to post performance from optimized builds. In general, I think this is correct. However, I still think it's silly to ask the compiler to optimize code when you in fact do not want that code optimized. It strikes me as being very similar to paying extra for valet parking, but refusing to hand over the keys. In this particular case, I don't want the optimizer running.

Using a slightly modified version of the benchmark (to address the valid point that the original program didn't allocate something on the stack each time through the loop) and compiling without optimizations but linking to release libraries (to address the valid point that we don't want to include any slowdown caused by linking to debug libraries):

#include <cstdio>
#include <chrono>

namespace {
    void on_stack()
    {
        int i;
    }

    void on_heap()
    {
        int* i = new int;
        delete i;
    }
}

int main()
{
    auto begin = std::chrono::system_clock::now();
    for (int i = 0; i < 1000000000; ++i)
        on_stack();
    auto end = std::chrono::system_clock::now();

    std::printf("on_stack took %f seconds\n", std::chrono::duration<double>(end - begin).count());

    begin = std::chrono::system_clock::now();
    for (int i = 0; i < 1000000000; ++i)
        on_heap();
    end = std::chrono::system_clock::now();

    std::printf("on_heap took %f seconds\n", std::chrono::duration<double>(end - begin).count());
    return 0;
}

displays:

on_stack took 2.070003 seconds
on_heap took 57.980081 seconds

on my system when compiled with the command line cl foo.cc /Od /MT /EHsc.

You may not agree with my approach to getting a non-optimized build. That's fine: feel free modify the benchmark as much as you want. When I turn on optimization, I get:

on_stack took 0.000000 seconds
on_heap took 51.608723 seconds

Not because stack allocation is actually instantaneous but because any half-decent compiler can notice that on_stack doesn't do anything useful and can be optimized away. GCC on my Linux laptop also notices that on_heap doesn't do anything useful, and optimizes it away as well:

on_stack took 0.000003 seconds
on_heap took 0.000002 seconds

Can I have H2 autocreate a schema in an in-memory database?

"By default, when an application calls DriverManager.getConnection(url, ...) and the database specified in the URL does not yet exist, a new (empty) database is created."—H2 Database.

Addendum: @Thomas Mueller shows how to Execute SQL on Connection, but I sometimes just create and populate in the code, as suggested below.

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.Statement;

/** @see http://stackoverflow.com/questions/5225700 */
public class H2MemTest {

    public static void main(String[] args) throws Exception {
        Connection conn = DriverManager.getConnection("jdbc:h2:mem:", "sa", "");
        Statement st = conn.createStatement();
        st.execute("create table customer(id integer, name varchar(10))");
        st.execute("insert into customer values (1, 'Thomas')");
        Statement stmt = conn.createStatement();
        ResultSet rset = stmt.executeQuery("select name from customer");
        while (rset.next()) {
            String name = rset.getString(1);
            System.out.println(name);
        }
    }
}

Error occurred during initialization of boot layer FindException: Module not found

I had similar issue, the problem i faced was i added the selenium-server-standalone-3.141.59.jar under modulepath instead it should be under classpath

so select classpath via (project -> Properties -> Java Bbuild Path -> Libraries) add the downloaded latest jar

After adding it must be something like this

enter image description here

And appropriate driver for browser has to be downloaded for me i checked and downloaded the same version of chrom for chrome driver and added in the C:\Program Files\Java

And following is the code that worked fine for me

    public class TestuiAautomation {

        public static void main(String[] args) {

            System.out.println("Jai Ganesha");
            try {
                System.setProperty("webdriver.chrome.driver", "C:\\Program Files\\Java\\chromedriver.exe");
                System.out.println(System.getProperty("webdriver.chrome.driver"));
                ChromeOptions chromeOptions = new ChromeOptions();
                chromeOptions.addArguments("no-sandbox");
                chromeOptions.addArguments("--test-type");
                chromeOptions.addArguments("disable-extensions");
                chromeOptions.addArguments("--start-maximized");
                WebDriver driver = new ChromeDriver(chromeOptions);
                driver.get("https://www.google.com");
                System.out.println("Google is selected");
            } catch (Exception e) {
                System.err.println(e);
            }

        }

    }

ng-options with simple array init

You can use ng-repeat with option like this:

<form>
    <select ng-model="yourSelect" 
        ng-options="option as option for option in ['var1', 'var2', 'var3']"
        ng-init="yourSelect='var1'"></select>
    <input type="hidden" name="yourSelect" value="{{yourSelect}}" />
</form>

When you submit your form you can get value of input hidden.


DEMO

ng-selected ng-repeat

How can I extract the folder path from file path in Python?

Here is my little utility helper for splitting paths int file, path tokens:

import os    
# usage: file, path = splitPath(s)
def splitPath(s):
    f = os.path.basename(s)
    p = s[:-(len(f))-1]
    return f, p

Converting from byte to int in java

byte b = (byte)0xC8;
int v1 = b;       // v1 is -56 (0xFFFFFFC8)
int v2 = b & 0xFF // v2 is 200 (0x000000C8)

Most of the time v2 is the way you really need.

Body set to overflow-y:hidden but page is still scrollable in Chrome

Technically, the size of your body and html are wider than the screen, so you will have scrolling. You will need to set margin:0; and padding:0; to avoid the scrolling behavior, and add some margin/padding to #content instead.

Fill DataTable from SQL Server database

If the variable table contains invalid characters (like a space) you should add square brackets around the variable.

public DataTable fillDataTable(string table)
{
    string query = "SELECT * FROM dstut.dbo.[" + table + "]";

    using(SqlConnection sqlConn = new SqlConnection(conSTR))
    using(SqlCommand cmd = new SqlCommand(query, sqlConn))
    {
        sqlConn.Open();
        DataTable dt = new DataTable();
        dt.Load(cmd.ExecuteReader());
        return dt;
    }
}

By the way, be very careful with this kind of code because is open to Sql Injection. I hope for you that the table name doesn't come from user input

Default nginx client_max_body_size

You have to increase client_max_body_size in nginx.conf file. This is the basic step. But if your backend laravel then you have to do some changes in the php.ini file as well. It depends on your backend. Below I mentioned file location and condition name.

sudo vim /etc/nginx/nginx.conf.

After open the file adds this into HTTP section.

client_max_body_size 100M;

Difference between File.separator and slash in paths

"Java SE8 for Programmers" claims that the Java will cope with either. (pp. 480, last paragraph). The example claims that:

c:\Program Files\Java\jdk1.6.0_11\demo/jfc

will parse just fine. Take note of the last (Unix-style) separator.

It's tacky, and probably error-prone, but it is what they (Deitel and Deitel) claim.

I think the confusion for people, rather than Java, is reason enough not to use this (mis?)feature.

Python and pip, list all versions of a package that's available?

You could the yolk3k package instead of yolk. yolk3k is a fork from the original yolk and it supports both python2 and 3.

https://github.com/myint/yolk

pip install yolk3k

How can I access getSupportFragmentManager() in a fragment?

getFragmentManager() has been deprecated in favor of getParentFragmentManager() to make it clear that you want to access the fragment manager of the parent instead of any child fragments.

Simply use getParentFragmentManager() in Java or parentFragmentManager in Kotlin.

How to efficiently build a tree from a flat structure?

Store IDs of the objects in a hash table mapping to the specific object. Enumerate through all the objects and find their parent if it exists and update its parent pointer accordingly.

class MyObject
{ // The actual object
    public int ParentID { get; set; }
    public int ID { get; set; }
}

class Node
{
    public List<Node> Children = new List<Node>();
    public Node Parent { get; set; }
    public MyObject AssociatedObject { get; set; }
}

IEnumerable<Node> BuildTreeAndGetRoots(List<MyObject> actualObjects)
{
    Dictionary<int, Node> lookup = new Dictionary<int, Node>();
    actualObjects.ForEach(x => lookup.Add(x.ID, new Node { AssociatedObject = x }));
    foreach (var item in lookup.Values) {
        Node proposedParent;
        if (lookup.TryGetValue(item.AssociatedObject.ParentID, out proposedParent)) {
            item.Parent = proposedParent;
            proposedParent.Children.Add(item);
        }
    }
    return lookup.Values.Where(x => x.Parent == null);
}

How to evaluate http response codes from bash/shell script?

I haven't tested this on a 500 code, but it works on others like 200, 302 and 404.

response=$(curl --write-out '%{http_code}' --silent --output /dev/null servername)

Note, format provided for --write-out should be quoted. As suggested by @ibai, add --head to make a HEAD only request. This will save time when the retrieval is successful since the page contents won't be transmitted.

"While .. End While" doesn't work in VBA?

While constructs are terminated not with an End While but with a Wend.

While counter < 20
    counter = counter + 1
Wend

Note that this information is readily available in the documentation; just press F1. The page you link to deals with Visual Basic .NET, not VBA. While (no pun intended) there is some degree of overlap in syntax between VBA and VB.NET, one can't just assume that the documentation for the one can be applied directly to the other.

Also in the VBA help file:

Tip The Do...Loop statement provides a more structured and flexible way to perform looping.

Null vs. False vs. 0 in PHP

I think bad developers find all different uses of null/0/false in there code.

For example, one of the most common mistakes developers make is to return error code in the form of data with a function.

// On error GetChar returns -1
int GetChar()

This is an example of a sugar interface. This is exsplained in the book "Debuging the software development proccess" and also in another book "writing correct code".

The problem with this, is the implication or assumptions made on the char type. On some compilers the char type can be non-signed. So even though you return a -1 the compiler can return 1 instead. These kind of compiler assumptions in C++ or C are hard to spot.

Instead, the best way is not to mix error code with your data. So the following function.

char GetChar()

now becomes

// On success return 1
// on failure return 0
bool GetChar(int &char)

This means no matter how young the developer is in your development shop, he or she will never get this wrong. Though this is not talking about redudancy or dependies in code.

So in general, swapping bool as the first class type in the language is okay and i think joel spoke about it with his recent postcast. But try not to use mix and match bools with your data in your routines and you should be perfectly fine.

Check if string contains only whitespace

Use the str.isspace() method:

Return True if there are only whitespace characters in the string and there is at least one character, False otherwise.

A character is whitespace if in the Unicode character database (see unicodedata), either its general category is Zs (“Separator, space”), or its bidirectional class is one of WS, B, or S.

Combine that with a special case for handling the empty string.

Alternatively, you could use str.strip() and check if the result is empty.

Android: Internet connectivity change listener

  1. first add dependency in your code as implementation 'com.treebo:internetavailabilitychecker:1.0.4'
  2. implements your class with InternetConnectivityListener.
public class MainActivity extends AppCompatActivity implements InternetConnectivityListener {

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

        InternetAvailabilityChecker.init(this);
        mInternetAvailabilityChecker = InternetAvailabilityChecker.getInstance();
        mInternetAvailabilityChecker.addInternetConnectivityListener(this);
    }

    @Override
    public void onInternetConnectivityChanged(boolean isConnected) {
        if (isConnected) {
            alertDialog = new AlertDialog.Builder(this).create();
            alertDialog.setTitle(" internet is connected or not");
            alertDialog.setMessage("connected");
            alertDialog.setButton(AlertDialog.BUTTON_NEUTRAL, "OK",
                    new DialogInterface.OnClickListener() {
                        public void onClick(DialogInterface dialog, int which) {
                            dialog.dismiss();
                        }
                    });
            alertDialog.show();

    }
    else {
            alertDialog = new AlertDialog.Builder(this).create();
            alertDialog.setTitle("internet is connected or not");
            alertDialog.setMessage("not connected");
            alertDialog.setButton(AlertDialog.BUTTON_NEUTRAL, "OK",
                    new DialogInterface.OnClickListener() {
                        public void onClick(DialogInterface dialog, int which) {
                            dialog.dismiss();
                        }
                    });
            alertDialog.show();

        }
    }
}

Python: Find a substring in a string and returning the index of the substring

Not directly answering the question but I got a similar question recently where I was asked to count the number of times a sub-string is repeated in a given string. Here is the function I wrote:

def count_substring(string, sub_string):
    cnt = 0
    len_ss = len(sub_string)
    for i in range(len(string) - len_ss + 1):
        if string[i:i+len_ss] == sub_string:
            cnt += 1
    return cnt

The find() function probably returns the index of the fist occurrence only. Storing the index in place of just counting, can give us the distinct set of indices the sub-string gets repeated within the string.

Disclaimer: I am 'extremly' new to Python programming.

Run jQuery function onclick

Why do you need to attach it to the HTML? Just bind the function with hover

$("div.system_box").hover(function(){ mousin }, 
                          function() { mouseout });

If you do insist to have JS references inside the html, which is usualy a bad idea you can use:

onmouseover="yourJavaScriptCode()"

after topic edit:

<div class="system_box" data-target="sms_box">

...

$("div.system_box").click(function(){ slideonlyone($(this).attr("data-target")); });

How can I list all of the files in a directory with Perl?

readdir() does that.

Check http://perldoc.perl.org/functions/readdir.html

opendir(DIR, $some_dir) || die "can't opendir $some_dir: $!";
@dots = grep { /^\./ && -f "$some_dir/$_" } readdir(DIR);
closedir DIR;

Play local (hard-drive) video file with HTML5 video tag?

That will be possible only if the HTML file is also loaded with the file protocol from the local user's harddisk.

If the HTML page is served by HTTP from a server, you can't access any local files by specifying them in a src attribute with the file:// protocol as that would mean you could access any file on the users computer without the user knowing which would be a huge security risk.

As Dimitar Bonev said, you can access a file if the user selects it using a file selector on their own. Without that step, it's forbidden by all browsers for good reasons. Thus, while his answer might prove useful for many people, it loosens the requirement from the code in the original question.

Face recognition Library

I know it has been a while, but for anyone else interested, there is the Faint project, which has bundled a lot of these features (detection, recognition, etc.) into a nice software package.

`node-pre-gyp install --fallback-to-build` failed during MeanJS installation on OSX

russfrisch commented 4 days ago:

I was experiencing this same issue. Changing in the version for grunt-node-inspector to prepend a ">=" instead of a "~" got this to work for me.

Link to github page where I found this solution.

Link to my post on StackoverFlow

Android intent for playing video?

following code works just fine for me.

Intent intent = new Intent(Intent.ACTION_VIEW, Uri.parse(movieurl));
startActivity(intent);

How to pass a callback as a parameter into another function

Also, could be simple as:

if( typeof foo == "function" )
    foo();

JavaScript - Get Portion of URL Path

window.location.href.split('/');

Will give you an array containing all the URL parts, which you can access like a normal array.

Or an ever more elegant solution suggested by @Dylan, with only the path parts:

window.location.pathname.split('/');

Quickest way to convert XML to JSON in Java

I found this the quick and easy way: Used: org.json.XML class from java-json.jar

if (statusCode == 200 && inputStream != null) {
    BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(inputStream, "UTF-8"));
    StringBuilder responseStrBuilder = new StringBuilder();

    String inputStr;
    while ((inputStr = bufferedReader.readLine()) != null) {
        responseStrBuilder.append(inputStr);
    }

    jsonObject = XML.toJSONObject(responseStrBuilder.toString());
}

getting error while updating Composer

This works for me with php 7.2

sudo apt-get install php7.2-xml

Deploying Maven project throws java.util.zip.ZipException: invalid LOC header (bad signature)

You need to check which jar is giving problem. It must be corrupted. Delete that jar and run mvn spring-boot:run command again. May be more that one jar has corrupted so every time you need to run that command to delete that jar. In my case mysql, jackson, aspect jars was corrupted mvn spring-boot:run command 3 times and I figure out this and deleted the jars from .m2 folder. Now the issue has resolved.

DBNull if statement

The idiomatic way is to say:

if(rsData["usr.ursrdaystime"] != DBNull.Value) {
    strLevel = rsData["usr.ursrdaystime"].ToString();
}

This:

rsData = objCmd.ExecuteReader();
rsData.Read();

Makes it look like you're reading exactly one value. Use IDbCommand.ExecuteScalar instead.

Limiting number of displayed results when using ngRepeat

Use limitTo filter to display a limited number of results in ng-repeat.

<ul class="phones">
      <li ng-repeat="phone in phones | limitTo:5">
        {{phone.name}}
        <p>{{phone.snippet}}</p>
      </li>
</ul>

append option to select menu?

You can also use insertAdjacentHTML function:

const select = document.querySelector('select')
const value = 'bmw'
const label = 'BMW'

select.insertAdjacentHTML('beforeend', `
  <option value="${value}">${label}</option>
`)

Java BigDecimal: Round to the nearest whole value

You want

round(new MathContext(0));  // or perhaps another math context with rounding mode HALF_UP

expected assignment or function call: no-unused-expressions ReactJS

In my case I had curly braces where it should have been parentheses.

const Button = () => {
    <button>Hello world</button>
}

Where it should have been:

const Button = () => (
    <button>Hello world</button>
)

The reason for this, as explained in the MDN Docs is that an arrow function wrapped by () will return the value it wraps, so if I wanted to use curly braces I had to add the return keyword, like so:

const Button = () => {
    return <button>Hello world</button>
}

How to calculate the sentence similarity using word2vec model of gensim with python

If not using Word2Vec we have other model to find it using BERT for embed. Below are reference link https://github.com/UKPLab/sentence-transformers

pip install -U sentence-transformers

from sentence_transformers import SentenceTransformer
import scipy.spatial

embedder = SentenceTransformer('bert-base-nli-mean-tokens')

# Corpus with example sentences
corpus = ['A man is eating a food.',
          'A man is eating a piece of bread.',
          'The girl is carrying a baby.',
          'A man is riding a horse.',
          'A woman is playing violin.',
          'Two men pushed carts through the woods.',
          'A man is riding a white horse on an enclosed ground.',
          'A monkey is playing drums.',
          'A cheetah is running behind its prey.'
          ]
corpus_embeddings = embedder.encode(corpus)

# Query sentences:
queries = ['A man is eating pasta.', 'Someone in a gorilla costume is playing a set of drums.', 'A cheetah chases prey on across a field.']
query_embeddings = embedder.encode(queries)

# Find the closest 5 sentences of the corpus for each query sentence based on cosine similarity
closest_n = 5
for query, query_embedding in zip(queries, query_embeddings):
    distances = scipy.spatial.distance.cdist([query_embedding], corpus_embeddings, "cosine")[0]

    results = zip(range(len(distances)), distances)
    results = sorted(results, key=lambda x: x[1])

    print("\n\n======================\n\n")
    print("Query:", query)
    print("\nTop 5 most similar sentences in corpus:")

    for idx, distance in results[0:closest_n]:
        print(corpus[idx].strip(), "(Score: %.4f)" % (1-distance))

Other Link to follow https://github.com/hanxiao/bert-as-service

Opacity CSS not working in IE8

None of the answers above worked for me, so I just gave my DIV tag a transparent background image instead, that worked perfectly for all browsers.

How do I create a new user in a SQL Azure database?

1 Create login while connecting to the master db (in your databaseclient open a connection to the master db)

CREATE LOGIN 'testUserLogin' WITH password='1231!#ASDF!a';

2 Create a user while connecting to your db (in your db client open a connection to your database)

CREATE USER testUserLoginFROM LOGIN testUserLogin; Please, note, user name is the same as login. It did not work for me when I had a different username and login.

3 Add required permissions

EXEC sp_addrolemember db_datawriter, 'testUser'; You may want to add 'db_datareader' as well.

list of the roles:

https://docs.microsoft.com/en-us/sql/relational-databases/security/authentication-access/database-level-roles?view=sql-server-ver15

I was inspired by @nthpixel answer, but it did not work for my db client DBeaver. It did not allow me to run USE [master] and use [my-db] statements.

https://azure.microsoft.com/en-us/blog/adding-users-to-your-sql-azure-database/

How to test your user?

Run the query bellow in the master database connection.

SELECT A.name as userName, B.name as login, B.Type_desc, default_database_name, B.*
FROM sys.sysusers A
    FULL OUTER JOIN sys.sql_logins B
       ON A.sid = B.sid
WHERE islogin = 1 and A.sid is not null

List of all users in Azure SQL

Java: String - add character n-times

Its better to use StringBuilder instead of String because String is an immutable class and it cannot be modified once created: in String each concatenation results in creating a new instance of the String class with the modified string.

How to import NumPy in the Python shell

On Debian/Ubuntu:

aptitude install python-numpy

On Windows, download the installer:

http://sourceforge.net/projects/numpy/files/NumPy/

On other systems, download the tar.gz and run the following:

$ tar xfz numpy-n.m.tar.gz
$ cd numpy-n.m
$ python setup.py install

How can I ignore a property when serializing using the DataContractSerializer?

What you are saying is in conflict with what it says in the MSDN library at this location:

http://msdn.microsoft.com/en-us/library/system.runtime.serialization.datacontractserializer.aspx

I don't see any mention of the SP1 feature you mention.

How to remove extension from string (only real extension!)

$image_name = "this-is.file.name.jpg";
$last_dot_index = strrpos($image_name, ".");
$without_extention = substr($image_name, 0, $last_dot_index);

Output:

this-is.file.name

Getting number of days in a month

  • int days = DateTime.DaysInMonth(DateTime.Now.Year, DateTime.Now.Month);


if you want to find days in this year and present month then this is best

MATLAB error: Undefined function or method X for input arguments of type 'double'

As others have pointed out, this is very probably a problem with the path of the function file not being in Matlab's 'path'.

One easy way to verify this is to open your function in the Editor and press the F5 key. This would make the Editor try to run the file, and in case the file is not in path, it will prompt you with a message box. Choose Add to Path in that, and you must be fine to go.

One side note: at the end of the above process, Matlab command window will give an error saying arguments missing: obviously, we didn't provide any arguments when we tried to run from the editor. But from now on you can use the function from the command line giving the correct arguments.

"unable to locate adb" using Android Studio

I fixed this issue by deleting and inserting new platform-tools folder inside android sdk folder. But it is caused by my Avast anti virus software. Where I can found my adb.exe in Avast chest. You can also solve by restoring it from Avast chest.

Create an array of strings

You need to use cell-arrays:

names = cell(10,1);
for i=1:10
    names{i} = ['Sample Text ' num2str(i)];
end

Can't check signature: public key not found

There is a similar problem.it is a tomcat digital signature.

$ gpg --verify apache-tomcat-9.0.16-windows-x64.zip.asc apache-tomcat-9.0.16-windows- 
x64.zip
gpg: Signature made 2019?02? 5?  0:32:50
gpg:                using RSA key A9C5DF4D22E99998D9875A5110C01C5A2F6059E7
gpg: Can't check signature: No public key

but then I use the RSA key it provided to receive the public key to verify.

$ gpg --receive-keys A9C5DF4D22E99998D9875A5110C01C5A2F6059E7
gpg: key 10C01C5A2F6059E7: 38 signatures not checked due to missing keys
gpg: key 10C01C5A2F6059E7: public key "Mark E D Thomas <[email protected]>" imported
gpg: no ultimately trusted keys found
gpg: Total number processed: 1
gpg:               imported: 1

Then successfully.

$ gpg --verify apache-tomcat-9.0.16-windows-x64.zip.asc
gpg: assuming signed data in 'apache-tomcat-9.0.16-windows-x64.zip'
gpg: Signature made 2019?02? 5?  0:32:50
gpg:                using RSA key A9C5DF4D22E99998D9875A5110C01C5A2F6059E7
gpg: Good signature from "Mark E D Thomas <[email protected]>" [unknown]
gpg: WARNING: This key is not certified with a trusted signature!
gpg:          There is no indication that the signature belongs to the owner.
Primary key fingerprint: A9C5 DF4D 22E9 9998 D987  5A51 10C0 1C5A 2F60 59E7

How do I find the PublicKeyToken for a particular dll?

Assembly.LoadFile(@"C:\Windows\Microsoft.NET\Framework\v4.0.30319\system.data.dll").FullName

Will result in

System.Data, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089

How to convert an object to JSON correctly in Angular 2 with TypeScript

Tested and working in Angular 9.0

If you're getting the data using API

array: [];

ngOnInit()    {
this.service.method()
.subscribe(
    data=>
  {
    this.array = JSON.parse(JSON.stringify(data.object));
  }
)

}

You can use that array to print your results from API data in html template.

Like

<p>{{array['something']}}</p>

Difference between logical addresses, and physical addresses?

logical address is address relative to program. It tells how much memory a particular process will take, not tell what will the exact location of the process and this exact location will we generated by using some mapping, and is known as physical address.

How to loop through an array of objects in swift

Your userPhotos array is option-typed, you should retrieve the actual underlying object with ! (if you want an error in case the object isn't there) or ? (if you want to receive nil in url):

let userPhotos = currentUser?.photos

for var i = 0; i < userPhotos!.count ; ++i {
    let url = userPhotos![i].url
}

But to preserve safe nil handling, you better use functional approach, for instance, with map, like this:

let urls = userPhotos?.map{ $0.url }

How to add DOM element script to head section?

If injecting multiple script tags in the head like this with mix of local and remote script files a situation may arise where the local scripts that are dependent on external scripts (such as loading jQuery from googleapis) will have errors because the external scripts may not be loaded before the local ones are.

So something like this would have a problem: ("jQuery is not defined" in jquery.some-plugin.js).

var head = document.getElementsByTagName('head')[0];

var script = document.createElement('script');
script.type = 'text/javascript';
script.src = "https://ajax.googleapis.com/ajax/libs/jquery/2.2.4/jquery.min.js";
head.appendChild(script);

var script = document.createElement('script');
script.type = 'text/javascript';
script.src = "/jquery.some-plugin.js";
head.appendChild(script);

Of course this situation is what the .onload() is for, but if multiple scripts are being loaded that can be cumbersome.

As a resolution to this situation, I put together this function that will keep a queue of scripts to be loaded, loading each subsequent item after the previous finishes, and returns a Promise that resolves when the script (or the last script in the queue if no parameter) is done loading.

load_script = function(src) {
    // Initialize scripts queue
    if( load_script.scripts === undefined ) {
        load_script.scripts = [];
        load_script.index = -1;
        load_script.loading = false;
        load_script.next = function() {
            if( load_script.loading ) return;

            // Load the next queue item
            load_script.loading = true;
            var item = load_script.scripts[++load_script.index];
            var head = document.getElementsByTagName('head')[0];
            var script = document.createElement('script');
            script.type = 'text/javascript';
            script.src = item.src;
            // When complete, start next item in queue and resolve this item's promise
            script.onload = () => {
                load_script.loading = false;
                if( load_script.index < load_script.scripts.length - 1 ) load_script.next();
                item.resolve();
            };
            head.appendChild(script);
        };
    };

    // Adding a script to the queue
    if( src ) {
        // Check if already added
        for(var i=0; i < load_script.scripts.length; i++) {
            if( load_script.scripts[i].src == src ) return load_script.scripts[i].promise;
        }
        // Add to the queue
        var item = { src: src };
        item.promise = new Promise(resolve => {item.resolve = resolve;});
        load_script.scripts.push(item);
        load_script.next();
    }

    // Return the promise of the last queue item
    return load_script.scripts[ load_script.scripts.length - 1 ].promise;
};

With this adding scripts in order ensuring the previous are done before staring the next can be done like...

["https://ajax.googleapis.com/ajax/libs/jquery/2.2.4/jquery.min.js",
 "/jquery.some-plugin.js",
 "/dependant-on-plugin.js",
].forEach(load_script);

Or load the script and use the return Promise to do work when it's complete...

load_script("some-script.js")
.then(function() {
    /* some-script.js is done loading */
});

How to set width of a div in percent in JavaScript?

document.getElementById('header').style.width = '50%';

If you are using Firebug or the Chrome/Safari Developer tools, execute the above in the console, and you'll see the Stack Overflow header shrink by 50%.

Append a single character to a string or char array in java?

new StringBuilder().append(str.charAt(0))
                   .append(str.charAt(10))
                   .append(str.charAt(20))
                   .append(str.charAt(30))
                   .toString();

This way you can get the new string with whatever characters you want.

Exchange Powershell - How to invoke Exchange 2010 module from inside script?

You can do this:

add-pssnapin Microsoft.Exchange.Management.PowerShell.E2010

and most of it will work (although MS support will tell you that doing this is not supported because it bypasses RBAC).

I've seen issues with some cmdlets (specifically enable/disable UMmailbox) not working with just the snapin loaded.

In Exchange 2010, they basically don't support using Powershell outside of the the implicit remoting environment of an actual EMS shell.

How to get rid of punctuation using NLTK tokenizer?

I just used the following code, which removed all the punctuation:

tokens = nltk.wordpunct_tokenize(raw)

type(tokens)

text = nltk.Text(tokens)

type(text)  

words = [w.lower() for w in text if w.isalpha()]

Is this the right way to clean-up Fragment back stack when leaving a deeply nested stack?

I have researched a lot for cleaning Backstack, and finally see Transaction BackStack and its management. Here is the solution that worked best for me.

 // CLEAR BACK STACK.
    private void clearBackStack() {
        final FragmentManager fragmentManager = getSupportFragmentManager();
        while (fragmentManager.getBackStackEntryCount() != 0) {
            fragmentManager.popBackStackImmediate();
        }
    }

The above method loops over all the transactions in the backstack and removes them immediately one at a time.

Note: above code sometime not work and i face ANR because of this code,so please do not try this.

Update below method remove all fregment of that "name" from backstack.

FragmentManager fragmentManager = getSupportFragmentManager();
fragmentManager.popBackStack("name",FragmentManager.POP_BACK_STACK_INCLUSIVE);
  • name If non-null, this is the name of a previous back state to look for; if found, all states up to that state will be popped. The
  • POP_BACK_STACK_INCLUSIVE flag can be used to control whether the named state itself is popped. If null, only the top state is popped.

How to connect to remote Redis server?

One thing that confused me a little bit with this command is that if redis-cli fails to connect using the passed connection string it will still put you in the redis-cli shell, i.e:

redis-cli
Could not connect to Redis at 127.0.0.1:6379: Connection refused
not connected> 

You'll then need to exit to get yourself out of the shell. I wasn't paying much attention here and kept passing in new redis-cli commands wondering why the command wasn't using my passed connection string.

Detect end of ScrollView

You can make use of the Support Library's NestedScrollView and it's NestedScrollView.OnScrollChangeListener interface.

https://developer.android.com/reference/android/support/v4/widget/NestedScrollView.html

Alternatively if your app is targeting API 23 or above, you can make use of the following method on the ScrollView:

View.setOnScrollChangeListener(OnScrollChangeListener listener) 

Then follow the example that @Fustigador described in his answer. Note however that as @Will described, you should consider adding a small buffer in case the user or system isn't able to reach the complete bottom of the list for any reason.

Also worth noting is that the scroll change listener will sometimes be called with negative values or values greater than the view height. Presumably these values represent the 'momentum' of the scroll action. However unless handled appropriately (floor / abs) they can cause problems detecting the scroll direction when the view is scrolled to the top or bottom of the range.

https://developer.android.com/reference/android/view/View.html#setOnScrollChangeListener(android.view.View.OnScrollChangeListener)

How can I put a ListView into a ScrollView without it collapsing?

Using a ListView to make it not scroll is extremely expensive and goes against the whole purpose of ListView. You should NOT do this. Just use a LinearLayout instead.

Send mail via CMD console

From Linux you can use 'swaks' which is available as an official packages on many distros including Debian/Ubuntu and Redhat/CentOS on EPEL:

swaks -f [email protected] -t [email protected] \
    --server mail.example.com

org.hibernate.exception.SQLGrammarException: could not insert [com.sample.Person]

I solved the error by modifying the following property in hibernate.cfg.xml

<property name="hibernate.hbm2ddl.auto">validate</property>

Earlier, the table was getting deleted each time I ran the program and now it doesnt, as hibernate only validates the schema and does not affect changes to it.

As far as I know you can also change from validate to update e.g.:

<property name="hibernate.hbm2ddl.auto">update</property>

Adding text to ImageView in Android

You can also use a TextView and set the background image to what you wanted in the ImageView. Furthermore if you were using the ImageView as a button you can set it to click-able

Here is some basic code for a TextView that shows an image with text on top of it.

<TextView
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:background="@drawable/your_image"
    android:text="your text here" />

How to redirect 404 errors to a page in ExpressJS?

If you want to redirect to error pages from your functions (routes) then do following things -

  1. Add general error messages code in your app.js -

    app.use(function(err, req, res, next) {
        // set locals, only providing error in development
        res.locals.message = err.message
        res.locals.error = req.app.get('env') === 'development' ? err : {}
    
        // render the error page
        // you can also serve different error pages
        // for example sake, I am just responding with simple error messages 
        res.status(err.status || 500)
       if(err.status === 403){
           return res.send('Action forbidden!');
       }
    
       if(err.status === 404){
           return res.send('Page not found!');
       }
    
       // when status is 500, error handler
       if(err.status === 500) {
           return res.send('Server error occured!');
       }
       res.render('error')
    })
    
  2. In your function, instead of using a error-page redirect you can use set the error status first and then use next() for the code flow to go through above code -

    if(FOUND){
        ...
    }else{
        // redirecting to general error page
        // any error code can be used (provided you have handled its error response)
        res.status(404)
        // calling next() will make the control to go call the step 1. error code
        // it will return the error response according to the error code given (provided you have handled its error response)
        next()
    }
    

How does a ArrayList's contains() method evaluate objects?

Other posters have addressed the question about how contains() works.

An equally important aspect of your question is how to properly implement equals(). And the answer to this is really dependent on what constitutes object equality for this particular class. In the example you provided, if you have two different objects that both have x=5, are they equal? It really depends on what you are trying to do.

If you are only interested in object equality, then the default implementation of .equals() (the one provided by Object) uses identity only (i.e. this == other). If that's what you want, then just don't implement equals() on your class (let it inherit from Object). The code you wrote, while kind of correct if you are going for identity, would never appear in a real class b/c it provides no benefit over using the default Object.equals() implementation.

If you are just getting started with this stuff, I strongly recommend the Effective Java book by Joshua Bloch. It's a great read, and covers this sort of thing (plus how to correctly implement equals() when you are trying to do more than identity based comparisons)

How to create major and minor gridlines with different linestyles in Python

A simple DIY way would be to make the grid yourself:

import matplotlib.pyplot as plt

fig = plt.figure()
ax = fig.add_subplot(111)

ax.plot([1,2,3], [2,3,4], 'ro')

for xmaj in ax.xaxis.get_majorticklocs():
  ax.axvline(x=xmaj, ls='-')
for xmin in ax.xaxis.get_minorticklocs():
  ax.axvline(x=xmin, ls='--')

for ymaj in ax.yaxis.get_majorticklocs():
  ax.axhline(y=ymaj, ls='-')
for ymin in ax.yaxis.get_minorticklocs():
  ax.axhline(y=ymin, ls='--')
plt.show()

Positioning <div> element at center of screen

Set the width and height and you're good.

div {
  position: absolute;
  margin: auto;
  top: 0;
  right: 0;
  bottom: 0;
  left: 0;
  width: 200px;
  height: 200px;
}

If you want the element dimensions to be flexible (and don't care about legacy browsers), go with XwipeoutX's answer.

How to disable gradle 'offline mode' in android studio?

Gradle is in offline mode, which means that it won't go to the network to resolve dependencies.

Go to Preferences > Gradle and uncheck "Offline work".

Javascript Get Element by Id and set the value

Coming across this question, no answer brought up the possibility of using .setAttribute() in addition to .value()

document.getElementById('some-input').value="1337";
document.getElementById('some-input').setAttribute("value", "1337");

Though unlikely helpful for the original questioner, this addendum actually changes the content of the value in the pages source, which in turn makes the value update form.reset()-proof.

I hope this may help others.

(Or me in half a year when I've forgotten about js quirks...)

Why does Oracle not find oci.dll?

If you are using TOAD, you will need to download the 32-bit version of the Oracle Client Tools.

Since the Client Tools are different on a per-processor architecture basis, you probably need to install versions.

How do I "select Android SDK" in Android Studio?

I get this error on Android Studio 4.0.1. Here is my solution: Go your build.gradle(Module: app) file and then update compileSdkVersion and buildToolsVersion.

android {
    compileSdkVersion 30
    buildToolsVersion "30.0.2"
}

How to get to a particular element in a List in java?

String[] is an array of Strings. Such an array is internally a class. Like all classes that don't explicitly extend some other class, it extends Object implicitly. The method toString() of class Object, by default, gives you the representation you see: the class name, followed by @, followed by the hash code in hex. Since the String[] class doesn't override the toString() method, you get that as a result.

Create some method that outputs the array elements for you. Iterate over the array and use System.out.print() (not print*ln*) on the elements.

How to add to an NSDictionary

For reference, you can also utilize initWithDictionary to init the NSMutableDictionary with a literal one:

NSMutableDictionary buttons = [[NSMutableDictionary alloc] initWithDictionary: @{
    @"touch": @0,
    @"app": @0,
    @"back": @0,
    @"volup": @0,
    @"voldown": @0
}];

Defining an abstract class without any abstract methods

Yes you can do it. Why don't you just try doing that?

Simple way to repeat a string

Java 8's String.join provides a tidy way to do this in conjunction with Collections.nCopies:

// say hello 100 times
System.out.println(String.join("", Collections.nCopies(100, "hello")));

Angular2, what is the correct way to disable an anchor element?

consider the following solution

.disable-anchor-tag { 
  pointer-events: none; 
}

What is the standard way to add N seconds to datetime.time in Python?

Thanks to @Pax Diablo, @bvmou and @Arachnid for the suggestion of using full datetimes throughout. If I have to accept datetime.time objects from an external source, then this seems to be an alternative add_secs_to_time() function:

def add_secs_to_time(timeval, secs_to_add):
    dummy_date = datetime.date(1, 1, 1)
    full_datetime = datetime.datetime.combine(dummy_date, timeval)
    added_datetime = full_datetime + datetime.timedelta(seconds=secs_to_add)
    return added_datetime.time()

This verbose code can be compressed to this one-liner:

(datetime.datetime.combine(datetime.date(1, 1, 1), timeval) + datetime.timedelta(seconds=secs_to_add)).time()

but I think I'd want to wrap that up in a function for code clarity anyway.

Removing specific rows from a dataframe

Here's a solution to your problem using dplyr's filter function.

Although you can pass your data frame as the first argument to any dplyr function, I've used its %>% operator, which pipes your data frame to one or more dplyr functions (just filter in this case).

Once you are somewhat familiar with dplyr, the cheat sheet is very handy.

> print(df <- data.frame(sub=rep(1:3, each=4), day=1:4))
   sub day
1    1   1
2    1   2
3    1   3
4    1   4
5    2   1
6    2   2
7    2   3
8    2   4
9    3   1
10   3   2
11   3   3
12   3   4
> print(df <- df %>% filter(!((sub==1 & day==2) | (sub==3 & day==4))))
   sub day
1    1   1
2    1   3
3    1   4
4    2   1
5    2   2
6    2   3
7    2   4
8    3   1
9    3   2
10   3   3

How can I make a clickable link in an NSAttributedString?

I just created a subclass of UILabel to specially address such use cases. You can add multiple links easily and define different handlers for them. It also supports highlighting the pressed link when you touch down for touch feedback. Please refer to https://github.com/null09264/FRHyperLabel.

In your case, the code may like this:

FRHyperLabel *label = [FRHyperLabel new];

NSString *string = @"This morph was generated with Face Dancer, Click to view in the app store.";
NSDictionary *attributes = @{NSFontAttributeName: [UIFont preferredFontForTextStyle:UIFontTextStyleHeadline]};

label.attributedText = [[NSAttributedString alloc]initWithString:string attributes:attributes];

[label setLinkForSubstring:@"Face Dancer" withLinkHandler:^(FRHyperLabel *label, NSString *substring){
    [[UIApplication sharedApplication] openURL:aURL];
}];

Sample Screenshot (the handler is set to pop an alert instead of open a url in this case)

facedancer

Linux command to list all available commands and aliases

You can use the bash(1) built-in compgen

  • compgen -c will list all the commands you could run.
  • compgen -a will list all the aliases you could run.
  • compgen -b will list all the built-ins you could run.
  • compgen -k will list all the keywords you could run.
  • compgen -A function will list all the functions you could run.
  • compgen -A function -abck will list all the above in one go.

Check the man page for other completions you can generate.

To directly answer your question:

compgen -ac | grep searchstr

should do what yout want.

C free(): invalid pointer

You can't call free on the pointers returned from strsep. Those are not individually allocated strings, but just pointers into the string s that you've already allocated. When you're done with s altogether, you should free it, but you do not have to do that with the return values of strsep.

Getting values from JSON using Python

Using your code, this is how I would do it. I know an answer was chosen, just giving additional options.

data = json.loads('{"lat":444, "lon":555}')
    ret = ''
    for j in data:
        ret = ret+" "+data[j]
return ret

When you use for in this manor you get the key of the object, not the value, so you can get the value, by using the key as an index.

LINQ query to select top five

[Offering a somewhat more descriptive answer than the answer provided by @Ajni.]

This can also be achieved using LINQ fluent syntax:

var list = ctn.Items
    .Where(t=> t.DeliverySelection == true && t.Delivery.SentForDelivery == null)
    .OrderBy(t => t.Delivery.SubmissionDate)
    .Take(5);

Note that each method (Where, OrderBy, Take) that appears in this LINQ statement takes a lambda expression as an argument. Also note that the documentation for Enumerable.Take begins with:

Returns a specified number of contiguous elements from the start of a sequence.

replace all occurrences in a string

As explained here, you can use:

function replaceall(str,replace,with_this)
{
    var str_hasil ="";
    var temp;

    for(var i=0;i<str.length;i++) // not need to be equal. it causes the last change: undefined..
    {
        if (str[i] == replace)
        {
            temp = with_this;
        }
        else
        {
                temp = str[i];
        }

        str_hasil += temp;
    }

    return str_hasil;
}

... which you can then call using:

var str = "50.000.000";
alert(replaceall(str,'.',''));

The function will alert "50000000"

How to find difference between two columns data?

There are many ways of doing this (and I encourage you to look them up as they will be more efficient generally) but the simplest way of doing this is to use a non-set operation to define the value of the third column:

SELECT
    t1.previous
    ,t1.present
    ,(t1.present - t1.previous) as difference
FROM #TEMP1 t1

Note, this style of selection is considered bad practice because it requires the query plan to reselect the value of the first two columns to logically determine the third (a violation of set theory that SQL is based on). Though it is more complicated, if you plan on using this to evaluate more than the values you listed in your example, I would investigate using an APPLY clause. http://technet.microsoft.com/en-us/library/ms175156(v=sql.105).aspx

Bulk Insert to Oracle using .NET

I'm loading 50,000 records in 15 or so seconds using Array Binding in ODP.NET

It works by repeatedly invoking a stored procedure you specify (and in which you can do updates/inserts/deletes), but it passes the multiple parameter values from .NET to the database in bulk.

Instead of specifying a single value for each parameter to the stored procedure you specify an array of values for each parameter.

Oracle passes the parameter arrays from .NET to the database in one go, and then repeatedly invokes the stored procedure you specify using the parameter values you specified.

http://www.oracle.com/technetwork/issue-archive/2009/09-sep/o59odpnet-085168.html

/Damian

Interface type check with Typescript

I found an example from @progress/kendo-data-query in file filter-descriptor.interface.d.ts

Checker

declare const isCompositeFilterDescriptor: (source: FilterDescriptor | CompositeFilterDescriptor) => source is CompositeFilterDescriptor;

Example usage

const filters: Array<FilterDescriptor | CompositeFilterDescriptor> = filter.filters;

filters.forEach((element: FilterDescriptor | CompositeFilterDescriptor) => {
    if (isCompositeFilterDescriptor(element)) {
        // element type is CompositeFilterDescriptor
    } else {
        // element type is FilterDescriptor
    }
});

Crop image to specified size and picture location

You would need to do something like this. I am typing this off the top of my head, so this may not be 100% correct.

CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB(); CGContextRef context = CGBitmapContextCreate(NULL, 640, 360, 8, 4 * width, colorSpace, kCGImageAlphaPremultipliedFirst); CGColorSpaceRelease(colorSpace);  CGContextDrawImage(context, CGRectMake(0,-160,640,360), cgImgFromAVCaptureSession);  CGImageRef image = CGBitmapContextCreateImage(context); UIImage* myCroppedImg = [UIImage imageWithCGImage:image]; CGContextRelease(context);       

Change icons of checked and unchecked for Checkbox for Android

it's android:button="@drawable/selector_checkbox" to make it work

Concatenation of strings in Lua

Strings can be joined together using the concatenation operator ".."

this is the same for variables I think

How to do INSERT into a table records extracted from another table

Remove "values" when you're appending a group of rows, and remove the extra parentheses. You can avoid the circular reference by using an alias for avg(CurrencyColumn) (as you did in your example) or by not using an alias at all.

If the column names are the same in both tables, your query would be like this:

INSERT INTO Table2 (LongIntColumn, Junk)
SELECT LongIntColumn, avg(CurrencyColumn) as CurrencyColumn1
FROM Table1
GROUP BY LongIntColumn;

And it would work without an alias:

INSERT INTO Table2 (LongIntColumn, Junk)
SELECT LongIntColumn, avg(CurrencyColumn)
FROM Table1
GROUP BY LongIntColumn;

Error 330 (net::ERR_CONTENT_DECODING_FAILED):

I had a bit of a dummy moment this morning when I realized what caused this issue for me.

The strange thing is that the request was failing in both Firefox and Chrome, but worked when I tried to access via Fiddler Web Debugger.

For me, the problem was I had mis-typed a character into one of the PHP files in the project. I didn't notice this until I checked Git for changes to the project.

In my case I had: m<?php runMyProgram(); ?>.

Once I erased the m, it started working again.

Programmatically open new pages on Tabs

Those of you trying to use the following:

window.open('page.html', '_newtab');

should really look at the window.open method.

All you are doing is telling the browser to open a new window NAMED "_newtab" and load page.html into it. Every new page you load will load into that window. However, if a user has their browser set to open new pages in new tabs instead of new windows, it will open a tab. Regardless, it's using the same name for the window or tab.

If you want different pages to open in different windows or tabs you will have to change the NAME of the new window/tab to something different such as:

window.open('page2.html', '_newtab2');

Of course the name for the new window/tab could be any name like page1, page2, page3, etc. instead of _newtab2.

"No X11 DISPLAY variable" - what does it mean?

One more thing that might be the problem in a case similar to described - X is not forwarded and $DISPLAY is not set when 'xauth' program is not installed on the remote side. You can see it searches for it when you run "ssh -Xv ip_address", and, if not found, fails, which's not seen unless you turn on verbose mode (a fail IMO). You can usually find 'xauth' in a package with the same name.

Apache Proxy: No protocol handler was valid

I am posting an answer here, since I had the same error message for a different reason.

This error message can happen, for example, if you are using apache httpd to proxy requests from a source on protocol A to target on protocol B.

Here is the example of my situation:

AH01144: No protocol handler was valid for the URL /sockjs-node/info (scheme 'ws').

In the case above, what was happening was simply the following. I had enabled mod proxy to proxy websocket requests to nodejs based on path /sockjs-node.

The problem is that node does not use the path /sockjs-node for websocket requests exclusively. It also uses this path for hosting REST entrypoints that deliver information about websockets.

In this manner, when the application would try to open http://localhost:7001/sockjs-node/info, apache httpd would be trying to route the rest call from HTTP protocol to to a Webscoket endpoint call. Node did not accept this.

This lead to the exception above.

So be mindful that even if you enable the right modules, if you try to do the wrong forwarding, this will end with apache httpd informing you that the protocol you tried to use on the target server is not valid.

selectOneMenu ajax events

I'd rather use more convenient itemSelect event. With this event you can use org.primefaces.event.SelectEvent objects in your listener.

<p:selectOneMenu ...>
    <p:ajax event="itemSelect" 
        update="messages"
        listener="#{beanMB.onItemSelectedListener}"/>
</p:selectOneMenu>

With such listener:

public void onItemSelectedListener(SelectEvent event){
    MyItem selectedItem = (MyItem) event.getObject();
    //do something with selected value
}

XSL xsl:template match="/"

The value of the match attribute of the <xsl:template> instruction must be a match pattern.

Match patterns form a subset of the set of all possible XPath expressions. The first, natural, limitation is that a match pattern must select a set of nodes. There are also other limitations. In particular, reverse axes are not allowed in the location steps (but can be specified within the predicates). Also, no variable or parameter references are allowed in XSLT 1.0, but using these is legal in XSLT 2.x.

/ in XPath denotes the root or document node. In XPath 2.0 (and hence XSLT 2.x) this can also be written as document-node().

A match pattern can contain the // abbreviation.

Examples of match patterns:

<xsl:template match="table">

can be applied on any element named table.

<xsl:template match="x/y">

can be applied on any element named y whose parent is an element named x.

<xsl:template match="*">

can be applied to any element.

<xsl:template match="/*">

can be applied only to the top element of an XML document.

<xsl:template match="@*">

can be applied to any attribute.

<xsl:template match="text()">

can be applied to any text node.

<xsl:template match="comment()">

can be applied to any comment node.

<xsl:template match="processing-instruction()">

can be applied to any processing instruction node.

<xsl:template match="node()">

can be applied to any node: element, text, comment or processing instructon.

Bind failed: Address already in use

Everyone is correct. However, if you're also busy testing your code your own application might still "own" the socket if it starts and stops relatively quickly. Try SO_REUSEADDR as a socket option:

What exactly does SO_REUSEADDR do?

This socket option tells the kernel that even if this port is busy (in the TIME_WAIT state), go ahead and reuse it anyway. If it is busy, but with another state, you will still get an address already in use error. It is useful if your server has been shut down, and then restarted right away while sockets are still active on its port. You should be aware that if any unexpected data comes in, it may confuse your server, but while this is possible, it is not likely.

It has been pointed out that "A socket is a 5 tuple (proto, local addr, local port, remote addr, remote port). SO_REUSEADDR just says that you can reuse local addresses. The 5 tuple still must be unique!" by Michael Hunter ([email protected]). This is true, and this is why it is very unlikely that unexpected data will ever be seen by your server. The danger is that such a 5 tuple is still floating around on the net, and while it is bouncing around, a new connection from the same client, on the same system, happens to get the same remote port. This is explained by Richard Stevens in ``2.7 Please explain the TIME_WAIT state.''.

How much faster is C++ than C#?

The garbage collection is the main reason Java# CANNOT be used for real-time systems.

  1. When will the GC happen?

  2. How long will it take?

This is non-deterministic.

How to get position of a certain element in strings vector, to use it as an index in ints vector?

To get a position of an element in a vector knowing an iterator pointing to the element, simply subtract v.begin() from the iterator:

ptrdiff_t pos = find(Names.begin(), Names.end(), old_name_) - Names.begin();

Now you need to check pos against Names.size() to see if it is out of bounds or not:

if(pos >= Names.size()) {
    //old_name_ not found
}

vector iterators behave in ways similar to array pointers; most of what you know about pointer arithmetic can be applied to vector iterators as well.

Starting with C++11 you can use std::distance in place of subtraction for both iterators and pointers:

ptrdiff_t pos = distance(Names.begin(), find(Names.begin(), Names.end(), old_name_));

How to Upload Image file in Retrofit 2

@Multipart
@POST(Config.UPLOAD_IMAGE)
Observable<Response<String>> uploadPhoto(@Header("Access-Token") String header, @Part MultipartBody.Part imageFile);

And you can call this api like this:

   public void uploadImage(File file) {
     // create multipart
     RequestBody requestFile = RequestBody.create(MediaType.parse("multipart/form-data"), file);
    MultipartBody.Part body = MultipartBody.Part.createFormData("image", file.getName(), requestFile);

    // upload
    getViewInteractor().showProfileUploadingProgress();

    Observable<Response<String>> observable = api.uploadPhoto("",body);

    // on Response
    subscribeForNetwork(observable, new ApiObserver<Response<String>>() {
        @Override
        public void onError(Throwable e) {
            getViewInteractor().hideProfileUploadingProgress();
        }

        @Override
        public void onResponse(Response<String> response) {

            if (response.code() != 200) {
                Timber.d("error " + response.code());
                return;
            }
            getViewInteractor().hideProfileUploadingProgress();
            getViewInteractor().onProfileImageUploadSuccess(response.body());

        }
    });

}

I want to align the text in a <td> to the top

Use <td valign="top" style="width: 259px"> instead...

What is the proper way to URL encode Unicode characters?

IRI (RFC 3987) is the latest standard that replaces the URI/URL (RFC 3986 and older) standards. URI/URL do not natively support Unicode (well, RFC 3986 adds provisions for future URI/URL-based protocols to support it, but does not update past RFCs). The "%uXXXX" scheme is a non-standard extension to allow Unicode in some situations, but is not universally implemented by everyone. IRI, on the other hand, fully supports Unicode, and requires that text be encoded as UTF-8 before then being percent-encoded.

$(document).ready shorthand

The multi-framework safe shorthand for ready is:

jQuery(function($, undefined) {
    // $ is guaranteed to be short for jQuery in this scope
    // undefined is provided because it could have been overwritten elsewhere
});

This is because jQuery isn't the only framework that uses the $ and undefined variables

How to Round to the nearest whole number in C#

You have the Math.Round function that does exactly what you want.

Math.Round(1.1) results with 1
Math.Round(1.8) will result with 2.... and so one.

Catching access violation exceptions?

As stated, there is no non Microsoft / compiler vendor way to do this on the windows platform. However, it is obviously useful to catch these types of exceptions in the normal try { } catch (exception ex) { } way for error reporting and more a graceful exit of your app (as JaredPar says, the app is now probably in trouble). We use _se_translator_function in a simple class wrapper that allows us to catch the following exceptions in a a try handler:

DECLARE_EXCEPTION_CLASS(datatype_misalignment)
DECLARE_EXCEPTION_CLASS(breakpoint)
DECLARE_EXCEPTION_CLASS(single_step)
DECLARE_EXCEPTION_CLASS(array_bounds_exceeded)
DECLARE_EXCEPTION_CLASS(flt_denormal_operand)
DECLARE_EXCEPTION_CLASS(flt_divide_by_zero)
DECLARE_EXCEPTION_CLASS(flt_inexact_result)
DECLARE_EXCEPTION_CLASS(flt_invalid_operation)
DECLARE_EXCEPTION_CLASS(flt_overflow)
DECLARE_EXCEPTION_CLASS(flt_stack_check)
DECLARE_EXCEPTION_CLASS(flt_underflow)
DECLARE_EXCEPTION_CLASS(int_divide_by_zero)
DECLARE_EXCEPTION_CLASS(int_overflow)
DECLARE_EXCEPTION_CLASS(priv_instruction)
DECLARE_EXCEPTION_CLASS(in_page_error)
DECLARE_EXCEPTION_CLASS(illegal_instruction)
DECLARE_EXCEPTION_CLASS(noncontinuable_exception)
DECLARE_EXCEPTION_CLASS(stack_overflow)
DECLARE_EXCEPTION_CLASS(invalid_disposition)
DECLARE_EXCEPTION_CLASS(guard_page)
DECLARE_EXCEPTION_CLASS(invalid_handle)
DECLARE_EXCEPTION_CLASS(microsoft_cpp)

The original class came from this very useful article:

http://www.codeproject.com/KB/cpp/exception.aspx

Show and hide a View with a slide up/down animation

Here's another way to do for multiple Button(In this case ImageView)

MainActivity.java

findViewById(R.id.arrowIV).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {

                if (strokeWidthIV.getAlpha() == 0f) {
                    findViewById(R.id.arrowIV).animate().rotationBy(180);

                    strokeWidthIV.animate().translationXBy(-120 * 4).alpha(1f);
                    findViewById(R.id.colorChooseIV).animate().translationXBy(-120 * 3).alpha(1f);
                    findViewById(R.id.saveIV).animate().translationXBy(-120 * 2).alpha(1f);
                    findViewById(R.id.clearAllIV).animate().translationXBy(-120).alpha(1f);
                } else {
                    findViewById(R.id.arrowIV).animate().rotationBy(180);

                    strokeWidthIV.animate().translationXBy(120 * 4).alpha(0f);
                    findViewById(R.id.colorChooseIV).animate().translationXBy(120 * 3).alpha(0f);
                    findViewById(R.id.saveIV).animate().translationXBy(120 * 2).alpha(0f);
                    findViewById(R.id.clearAllIV).animate().translationXBy(120).alpha(0f);
                }
            }
        });

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout 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"
 android:layout_width="match_parent"
 android:layout_height="match_parent"
 tools:context=".activity.MainActivity">

 <ImageView
     android:id="@+id/strokeWidthIV"
     android:layout_width="48dp"
     android:layout_height="48dp"
     android:layout_margin="8dp"
     android:alpha="0"
     android:contentDescription="Clear All"
     android:padding="4dp"
     android:scaleType="fitXY"
     android:src="@drawable/ic_edit"
     app:layout_constraintEnd_toEndOf="parent"
     app:layout_constraintTop_toTopOf="parent"
     tools:ignore="HardcodedText" />

 <ImageView
     android:id="@+id/colorChooseIV"
     android:layout_width="48dp"
     android:layout_height="48dp"
     android:layout_margin="8dp"
     android:alpha="0"
     android:contentDescription="Clear All"
     android:padding="4dp"
     android:scaleType="fitXY"
     android:src="@drawable/ic_palette"
     app:layout_constraintEnd_toEndOf="parent"
     app:layout_constraintTop_toTopOf="parent"
     tools:ignore="HardcodedText" />

 <ImageView
     android:id="@+id/saveIV"
     android:layout_width="48dp"
     android:layout_height="48dp"
     android:layout_margin="8dp"
     android:alpha="0"
     android:contentDescription="Clear All"
     android:padding="4dp"
     android:scaleType="fitXY"
     android:src="@drawable/ic_save"
     app:layout_constraintEnd_toEndOf="parent"
     app:layout_constraintTop_toTopOf="parent"
     tools:ignore="HardcodedText" />

 <ImageView
     android:id="@+id/clearAllIV"
     android:layout_width="48dp"
     android:layout_height="48dp"
     android:layout_margin="8dp"
     android:alpha="0"
     android:contentDescription="Clear All"
     android:padding="4dp"
     android:scaleType="fitXY"
     android:src="@drawable/ic_clear_all"
     app:layout_constraintEnd_toEndOf="parent"
     app:layout_constraintTop_toTopOf="parent"
     tools:ignore="HardcodedText" />

 <ImageView
     android:id="@+id/arrowIV"
     android:layout_width="48dp"
     android:layout_height="48dp"
     android:layout_margin="8dp"
     android:contentDescription="Arrow"
     android:padding="4dp"
     android:scaleType="fitXY"
     android:src="@drawable/ic_arrow"
     app:layout_constraintEnd_toEndOf="parent"
     app:layout_constraintTop_toTopOf="parent"
     tools:ignore="HardcodedText" />
</androidx.constraintlayout.widget.ConstraintLayout>

Unable to use Intellij with a generated sources folder

Maybe you can add a step to the generate-sources phase that moves the folder?

set up device for development (???????????? no permissions)

Please DO NOT follow solutions suggesting to use sudo (sudo adb start-server)! This run adb as root (administrator) and it is NOT supposed to run like that!!! It's a BAD workaround!

Everything running as root can do anything in your system, if it creates or modify a file can change its permission to be only used by root. Again, DON'T!

The right thing to do is set up your system to make the USER have the permission, check out this guide i wrote on how to do it properly.

Open a file with Notepad in C#

You need System.Diagnostics.Process.Start().

The simplest example:

Process.Start("notepad.exe", fileName);

More Generic Approach:

Process.Start(fileName);

The second approach is probably a better practice as this will cause the windows Shell to open up your file with it's associated editor. Additionally, if the file specified does not have an association, it'll use the Open With... dialog from windows.

Note to those in the comments, thankyou for your input. My quick n' dirty answer was slightly off, i've updated the answer to reflect the correct way.

Sort matrix according to first column in R

Read the data:

foo <- read.table(text="1 349
  1 393
  1 392
  4 459
  3 49
  3 32
  2 94")

And sort:

foo[order(foo$V1),]

This relies on the fact that order keeps ties in their original order. See ?order.

How to download source in ZIP format from GitHub?

In chrome, if you hover your cursor on Download ZIP it will give you the link at the bottom of the browser

enter image description here

Richtextbox wpf binding

I can give you an ok solution and you can go with it, but before I do I'm going to try to explain why Document is not a DependencyProperty to begin with.

During the lifetime of a RichTextBox control, the Document property generally doesn't change. The RichTextBox is initialized with a FlowDocument. That document is displayed, can be edited and mangled in many ways, but the underlying value of the Document property remains that one instance of the FlowDocument. Therefore, there is really no reason it should be a DependencyProperty, ie, Bindable. If you have multiple locations that reference this FlowDocument, you only need the reference once. Since it is the same instance everywhere, the changes will be accessible to everyone.

I don't think FlowDocument supports document change notifications, though I am not sure.

That being said, here's a solution. Before you start, since RichTextBox doesn't implement INotifyPropertyChanged and Document is not a DependencyProperty, we have no notifications when the RichTextBox's Document property changes, so the binding can only be OneWay.

Create a class that will provide the FlowDocument. Binding requires the existence of a DependencyProperty, so this class inherits from DependencyObject.

class HasDocument : DependencyObject
{
    public static readonly DependencyProperty DocumentProperty =
        DependencyProperty.Register("Document", 
                                    typeof(FlowDocument), 
                                    typeof(HasDocument), 
                                    new PropertyMetadata(new PropertyChangedCallback(DocumentChanged)));

    private static void DocumentChanged(DependencyObject obj, DependencyPropertyChangedEventArgs e)
    {
        Debug.WriteLine("Document has changed");
    }

    public FlowDocument Document
    {
        get { return GetValue(DocumentProperty) as FlowDocument; }
        set { SetValue(DocumentProperty, value); }
    }
}

Create a Window with a rich text box in XAML.

<Window x:Class="samples.Window1"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    Title="Flow Document Binding" Height="300" Width="300"
    >
    <Grid>
      <RichTextBox Name="richTextBox" />
    </Grid>
</Window>

Give the Window a field of type HasDocument.

HasDocument hasDocument;

Window constructor should create the binding.

hasDocument = new HasDocument();

InitializeComponent();

Binding b = new Binding("Document");
b.Source = richTextBox;
b.Mode = BindingMode.OneWay;
BindingOperations.SetBinding(hasDocument, HasDocument.DocumentProperty, b);

If you want to be able to declare the binding in XAML, you would have to make your HasDocument class derive from FrameworkElement so that it can be inserted into the logical tree.

Now, if you were to change the Document property on HasDocument, the rich text box's Document will also change.

FlowDocument d = new FlowDocument();
Paragraph g = new Paragraph();
Run a = new Run();
a.Text = "I showed this using a binding";
g.Inlines.Add(a);
d.Blocks.Add(g);

hasDocument.Document = d;

Split code over multiple lines in an R script

For that particular case there is file.path :

File <- file.path("~", 
  "a", 
  "very", 
  "long",
  "path",
  "here",
  "that",
  "goes",
  "beyond",
  "80",
  "characters",
  "and",
  "then",
  "some",
  "more")
setwd(File)

Why is synchronized block better than synchronized method?

synchronized should only be used when you want your class to be Thread safe. In fact most of the classes should not use synchronized anyways. synchronized method would only provide a lock on this object and only for the duration of its execution. if you really wanna to make your classes thread safe, you should consider making your variables volatile or synchronize the access.

one of the issues of using synchronized method is that all of the members of the class would use the same lock which will make your program slower. In your case synchronized method and block would execute no different. what I'd would recommend is to use a dedicated lock and use a synchronized block something like this.

public class AClass {
private int x;
private final Object lock = new Object();     //it must be final!

 public void setX() {
    synchronized(lock) {
        x++;
    }
 }
}

Can't get Gulp to run: cannot find module 'gulp-util'

This will solve all gulp problem

sudo npm install gulp && sudo npm install --save del && sudo gulp build

How to scroll to the bottom of a RecyclerView? scrollToPosition doesn't work

This works perfectly fine for me:

AdapterChart adapterChart = new AdapterChart(getContext(),messageList);
recyclerView.setAdapter(adapterChart);
recyclerView.scrollToPosition(recyclerView.getAdapter().getItemCount()-1);

HTTP 404 Page Not Found in Web Api hosted in IIS 7.5

Don't forget to deploy global.asax

Use RSA private key to generate public key?

People looking for SSH public key...

If you're looking to extract the public key for use with OpenSSH, you will need to get the public key a bit differently

$ ssh-keygen -y -f mykey.pem > mykey.pub

This public key format is compatible with OpenSSH. Append the public key to remote:~/.ssh/authorized_keys and you'll be good to go


docs from SSH-KEYGEN(1)

ssh-keygen -y [-f input_keyfile]  

-y This option will read a private OpenSSH format file and print an OpenSSH public key to stdout.

Could not load file or assembly 'System.Web.WebPages.Razor, Version=3.0.0.0

Another option is to update the Microsoft.AspnNet.Mvc NuGet package. Be careful, because NuGet update does not update the Web.Config. You should update all previous version numbers to updated number. For example if you update from asp.net MVC 4.0.0.0 to 5.0.0.0, then this should be replaced in the Web.Config:

    <sectionGroup name="system.web.webPages.razor" type="System.Web.WebPages.Razor.Configuration.RazorWebSectionGroup, System.Web.WebPages.Razor, Version=3.0.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35">
      <section name="host" type="System.Web.WebPages.Razor.Configuration.HostSection, System.Web.WebPages.Razor, Version=3.0.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" requirePermission="false" />
      <section name="pages" type="System.Web.WebPages.Razor.Configuration.RazorPagesSection, System.Web.WebPages.Razor, Version=3.0.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" requirePermission="false" />
    </sectionGroup>
  </configSections>

 <host factoryType="System.Web.Mvc.MvcWebRazorHostFactory, System.Web.Mvc, Version=5.0.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" />

<pages
    validateRequest="false"
    pageParserFilterType="System.Web.Mvc.ViewTypeParserFilter, System.Web.Mvc, Version=5.0.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"
    pageBaseType="System.Web.Mvc.ViewPage, System.Web.Mvc, Version=5.0.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"
    userControlBaseType="System.Web.Mvc.ViewUserControl, System.Web.Mvc, Version=5.0.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35">
  <controls>
    <add assembly="System.Web.Mvc, Version=5.0.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" namespace="System.Web.Mvc" tagPrefix="mvc" />
  </controls>
</pages>

Adding text to a cell in Excel using VBA

You need to use Range and Value functions.
Range would be the cell where you want the text you want
Value would be the text that you want in that Cell

Range("A1").Value="whatever text"

How to call jQuery function onclick?

JS

 $(function () {
    var url = $(location).attr('href');
    $('#spn_url').html('<strong>' + url + '</strong>');
    $("#submit").click(function () {
        alert('button clicked');
    });
});

html

<input id="submit" type="submit" value="submit" name="submit">

Update row values where certain condition is met in pandas

You can do the same with .ix, like this:

In [1]: df = pd.DataFrame(np.random.randn(5,4), columns=list('abcd'))

In [2]: df
Out[2]: 
          a         b         c         d
0 -0.323772  0.839542  0.173414 -1.341793
1 -1.001287  0.676910  0.465536  0.229544
2  0.963484 -0.905302 -0.435821  1.934512
3  0.266113 -0.034305 -0.110272 -0.720599
4 -0.522134 -0.913792  1.862832  0.314315

In [3]: df.ix[df.a>0, ['b','c']] = 0

In [4]: df
Out[4]: 
          a         b         c         d
0 -0.323772  0.839542  0.173414 -1.341793
1 -1.001287  0.676910  0.465536  0.229544
2  0.963484  0.000000  0.000000  1.934512
3  0.266113  0.000000  0.000000 -0.720599
4 -0.522134 -0.913792  1.862832  0.314315

EDIT

After the extra information, the following will return all columns - where some condition is met - with halved values:

>> condition = df.a > 0
>> df[condition][[i for i in df.columns.values if i not in ['a']]].apply(lambda x: x/2)

I hope this helps!

How to use MySQLdb with Python and Django in OSX 10.6?

I had the same problem on OSX 10.6.6. But just a simple easy_install mysql-python on terminal did not solve it as another hiccup followed:

error: command 'gcc-4.2' failed with exit status 1.

Apparently, this issue arises after upgrading from XCode3 (which is natively shipped with OSX 10.6) to XCode4. This newer ver removes support for building ppc arch. If its the same case, try doing as follows before easy_install mysql-python

sudo bash
export ARCHFLAGS='-arch i386 -arch x86_64'
rm -r build
python setup.py build
python setup.py install

Many thanks to Ned Deily for this solution. Check here

Combine [NgStyle] With Condition (if..else)

Trying to set background color based on condition:   

Consider variable x with some numeric value.    
<p [ngStyle]="{ backgroundColor: x > 4 ? 'lightblue' : 'transparent' }">
        This is a sample Text
</p>

Clearing coverage highlighting in Eclipse

Click the "Remove all Sessions" button in the toolbar of the "Coverage" view.

enter image description here

Cannot make a static reference to the non-static method fxn(int) from the type Two

You cannot refer non-static members from a static method.

Non-Static members (like your fxn(int y)) can be called only from an instance of your class.

Example:

You can do this:

       public class A
       {
           public   int fxn(int y) {
              y = 5;
              return y;
          }
       }


  class Two {
public static void main(String[] args) {
    int x = 0;
    A a = new A();
    System.out.println("x = " + x);
    x = a.fxn(x);
    System.out.println("x = " + x);
}

or you can declare you method as static.

How to check if user input is not an int value

Maybe you can try this:

int function(){
Scanner input = new Scanner(System.in);   
System.out.print("Enter an integer between 1-100: ");   
int range;
while(true){   
    if(input.hasNextInt()){   
    range = input.nextInt();
    if(0<=range && range <= 100)
        break;
    else
        continue;
    }
    input.nextLine();  //Comsume the garbage value
    System.out.println("Enter an integer between 1-100:");
}
return range;
}

Entity Framework Core: DbContextOptionsBuilder does not contain a definition for 'usesqlserver' and no extension method 'usesqlserver'

Project is works in DotNET Core 3.1+ or higher(future)

Add this package:

  1. NuGet: Microsoft.EntityFrameworkCore.Tools
  2. Project Config (.csproj): <PackageReference Include="Microsoft.EntityFrameworkCore.Tools" Version="3.1.8">

Is there any native DLL export functions viewer?

dumpbin from the Visual Studio command prompt:

dumpbin /exports csp.dll

Example of output:

Microsoft (R) COFF/PE Dumper Version 10.00.30319.01
Copyright (C) Microsoft Corporation.  All rights reserved.


Dump of file csp.dll

File Type: DLL

  Section contains the following exports for CSP.dll

    00000000 characteristics
    3B1D0B77 time date stamp Tue Jun 05 12:40:23 2001
        0.00 version
           1 ordinal base
          25 number of functions
          25 number of names

    ordinal hint RVA      name

          1    0 00001470 CPAcquireContext
          2    1 000014B0 CPCreateHash
          3    2 00001520 CPDecrypt
          4    3 000014B0 CPDeriveKey
          5    4 00001590 CPDestroyHash
          6    5 00001590 CPDestroyKey
          7    6 00001560 CPEncrypt
          8    7 00001520 CPExportKey
          9    8 00001490 CPGenKey
         10    9 000015B0 CPGenRandom
         11    A 000014D0 CPGetHashParam
         12    B 000014D0 CPGetKeyParam
         13    C 00001500 CPGetProvParam
         14    D 000015C0 CPGetUserKey
         15    E 00001580 CPHashData
         16    F 000014F0 CPHashSessionKey
         17   10 00001540 CPImportKey
         18   11 00001590 CPReleaseContext
         19   12 00001580 CPSetHashParam
         20   13 00001580 CPSetKeyParam
         21   14 000014F0 CPSetProvParam
         22   15 00001520 CPSignHash
         23   16 000015A0 CPVerifySignature
         24   17 00001060 DllRegisterServer
         25   18 00001000 DllUnregisterServer

  Summary

        1000 .data
        1000 .rdata
        1000 .reloc
        1000 .rsrc
        1000 .text

Received fatal alert: handshake_failure through SSLHandshakeException

The handshake failure could have occurred due to various reasons:

  • Incompatible cipher suites in use by the client and the server. This would require the client to use (or enable) a cipher suite that is supported by the server.
  • Incompatible versions of SSL in use (the server might accept only TLS v1, while the client is capable of only using SSL v3). Again, the client might have to ensure that it uses a compatible version of the SSL/TLS protocol.
  • Incomplete trust path for the server certificate; the server's certificate is probably not trusted by the client. This would usually result in a more verbose error, but it is quite possible. Usually the fix is to import the server's CA certificate into the client's trust store.
  • The cerificate is issued for a different domain. Again, this would have resulted in a more verbose message, but I'll state the fix here in case this is the cause. The resolution in this case would be get the server (it does not appear to be yours) to use the correct certificate.

Since, the underlying failure cannot be pinpointed, it is better to switch on the -Djavax.net.debug=all flag to enable debugging of the SSL connection established. With the debug switched on, you can pinpoint what activity in the handshake has failed.

Update

Based on the details now available, it appears that the problem is due to an incomplete certificate trust path between the certificate issued to the server, and a root CA. In most cases, this is because the root CA's certificate is absent in the trust store, leading to the situation where a certificate trust path cannot exist; the certificate is essentially untrusted by the client. Browsers can present a warning so that users may ignore this, but the same is not the case for SSL clients (like the HttpsURLConnection class, or any HTTP Client library like Apache HttpComponents Client).

Most these client classes/libraries would rely on the trust store used by the JVM for certificate validation. In most cases, this will be the cacerts file in the JRE_HOME/lib/security directory. If the location of the trust store has been specified using the JVM system property javax.net.ssl.trustStore, then the store in that path is usually the one used by the client library. If you are in doubt, take a look at your Merchant class, and figure out the class/library it is using to make the connection.

Adding the server's certificate issuing CA to this trust store ought to resolve the problem. You can refer to my answer on a related question on getting tools for this purpose, but the Java keytool utility is sufficient for this purpose.

Warning: The trust store is essentially the list of all CAs that you trust. If you put in an certificate that does not belong to a CA that you do not trust, then SSL/TLS connections to sites having certificates issued by that entity can be decrypted if the private key is available.

Update #2: Understanding the output of the JSSE trace

The keystore and the truststores used by the JVM are usually listed at the very beginning, somewhat like the following:

keyStore is : 
keyStore type is : jks
keyStore provider is : 
init keystore
init keymanager of type SunX509
trustStore is: C:\Java\jdk1.6.0_21\jre\lib\security\cacerts
trustStore type is : jks
trustStore provider is : 

If the wrong truststore is used, then you'll need to re-import the server's certificate to the right one, or reconfigure the server to use the one listed (not recommended if you have multiple JVMs, and all of them are used for different needs).

If you want to verify if the list of trust certs contains the required certs, then there is a section for the same, that starts as:

adding as trusted cert:
  Subject: CN=blah, O=blah, C=blah
  Issuer:  CN=biggerblah, O=biggerblah, C=biggerblah
  Algorithm: RSA; Serial number: yadda
  Valid from SomeDate until SomeDate

You'll need to look for if the server's CA is a subject.

The handshake process will have a few salient entries (you'll need to know SSL to understand them in detail, but for the purpose of debugging the current problem, it will suffice to know that a handshake_failure is usually reported in the ServerHello.

1. ClientHello

A series of entries will be reported when the connection is being initialized. The first message sent by the client in a SSL/TLS connection setup is the ClientHello message, usually reported in the logs as:

*** ClientHello, TLSv1
RandomCookie:  GMT: 1291302508 bytes = { some byte array }
Session ID:  {}
Cipher Suites: [SSL_RSA_WITH_RC4_128_MD5, SSL_RSA_WITH_RC4_128_SHA, TLS_RSA_WITH_AES_128_CBC_SHA, TLS_DHE_RSA_WITH_AES_128_CBC_SHA, TLS_DHE_DSS_WITH_AES_128_CBC_SHA, SSL_RSA_WITH_3DES_EDE_CBC_SHA, SSL_DHE_RSA_WITH_3DES_EDE_CBC_SHA, SSL_DHE_DSS_WITH_3DES_EDE_CBC_SHA, SSL_RSA_WITH_DES_CBC_SHA, SSL_DHE_RSA_WITH_DES_CBC_SHA, SSL_DHE_DSS_WITH_DES_CBC_SHA, SSL_RSA_EXPORT_WITH_RC4_40_MD5, SSL_RSA_EXPORT_WITH_DES40_CBC_SHA, SSL_DHE_RSA_EXPORT_WITH_DES40_CBC_SHA, SSL_DHE_DSS_EXPORT_WITH_DES40_CBC_SHA]
Compression Methods:  { 0 }
***

Note the cipher suites used. This might have to agree with the entry in your merchant.properties file, for the same convention might be employed by the bank's library. If the convention used is different, there is no cause of worry, for the ServerHello will state so, if the cipher suite is incompatible.

2. ServerHello

The server responds with a ServerHello, that will indicate if the connection setup can proceed. Entries in the logs are usually of the following type:

*** ServerHello, TLSv1
RandomCookie:  GMT: 1291302499 bytes = { some byte array}
Cipher Suite: SSL_RSA_WITH_RC4_128_SHA
Compression Method: 0
***

Note the cipher suite that it has chosen; this is best suite available to both the server and the client. Usually the cipher suite is not specified if there is an error. The certificate of the server (and optionally the entire chain) is sent by the server, and would be found in the entries as:

*** Certificate chain
chain [0] = [
[
  Version: V3
  Subject: CN=server, O=server's org, L=server's location, ST =Server's state, C=Server's country
  Signature Algorithm: SHA1withRSA, OID = some identifer

.... the rest of the certificate
***

If the verification of the certificate has succeeded, you'll find an entry similar to:

Found trusted certificate:
[
[
  Version: V1
  Subject: OU=Server's CA, O="Server's CA's company name", C=CA's country
  Signature Algorithm: SHA1withRSA, OID = some identifier

One of the above steps would not have succeeded, resulting in the handshake_failure, for the handshake is typically complete at this stage (not really, but the subsequent stages of the handshake typically do not cause a handshake failure). You'll need to figure out which step has failed, and post the appropriate message as an update to the question (unless you've already understood the message, and you know what to do to resolve it).

dyld: Library not loaded: @rpath/libswiftCore.dylib

I have the same issue, and the issue is like this:

dyld: Library not loaded: @rpath/Result.framework/Result Referenced from: /private/var/mobile/Containers/Bundle/Application/74AD1FE2-7095-47D2-B059-520863050EE2/ReactiveCocoaTest.app/Frameworks/ReactiveCocoa.framework/ReactiveCocoa Reason: image not found

My solution is below:

In the TARGET -> Build Setting -> Other Linker Flag -> delete the ReactiveCocoa framework. If is xxx.framework, you know, you should delete the xxx.

delete the ReactiveCocoa

delete the ReactiveCocoa

Notification not showing in Oreo

I have faced the problem but found a unique solution.
for me this was the old code

String NOTIFICATION_CHANNEL_ID = "com.codedevtech.emplitrack";

and the working code is

String NOTIFICATION_CHANNEL_ID = "emplitrack_channel";

may be the channel id should not contain dot '.'

Python: can't assign to literal

This is taken from the Python docs:

Identifiers (also referred to as names) are described by the following lexical definitions:

identifier ::=  (letter|"_") (letter | digit | "_")*

letter     ::=  lowercase | uppercase

lowercase  ::=  "a"..."z"

uppercase  ::=  "A"..."Z"

digit      ::=  "0"..."9"

Identifiers are unlimited in length. Case is significant.

That should explain how to name your variables.