Programs & Examples On #Normal distribution

The normal distribution is an assumption of many parametric statistical tests, and is typically associated with a Gaussian distribution, often with mean=0 and standard deviation=1. The "bell curve" is the visual, intuitive model for this distribution. Gaussian distributions are associated with the function: f(x) = [1/(σ√2π)] e^(-[(x-μ)^2]/(2σ^2 ))

How to calculate the inverse of the normal cumulative distribution function in python?

NORMSINV (mentioned in a comment) is the inverse of the CDF of the standard normal distribution. Using scipy, you can compute this with the ppf method of the scipy.stats.norm object. The acronym ppf stands for percent point function, which is another name for the quantile function.

In [20]: from scipy.stats import norm

In [21]: norm.ppf(0.95)
Out[21]: 1.6448536269514722

Check that it is the inverse of the CDF:

In [34]: norm.cdf(norm.ppf(0.95))
Out[34]: 0.94999999999999996

By default, norm.ppf uses mean=0 and stddev=1, which is the "standard" normal distribution. You can use a different mean and standard deviation by specifying the loc and scale arguments, respectively.

In [35]: norm.ppf(0.95, loc=10, scale=2)
Out[35]: 13.289707253902945

If you look at the source code for scipy.stats.norm, you'll find that the ppf method ultimately calls scipy.special.ndtri. So to compute the inverse of the CDF of the standard normal distribution, you could use that function directly:

In [43]: from scipy.special import ndtri

In [44]: ndtri(0.95)
Out[44]: 1.6448536269514722

Perform a Shapiro-Wilk Normality Test

You are applying shapiro.test() to a data.frame instead of the column. Try the following:

shapiro.test(heisenberg$HWWIchg)

Generate random numbers following a normal distribution in C/C++

Use std::tr1::normal_distribution.

The std::tr1 namespace is not a part of boost. It's the namespace that contains the library additions from the C++ Technical Report 1 and is available in up to date Microsoft compilers and gcc, independently of boost.

Seeing if data is normally distributed in R

Normality tests don't do what most think they do. Shapiro's test, Anderson Darling, and others are null hypothesis tests AGAINST the the assumption of normality. These should not be used to determine whether to use normal theory statistical procedures. In fact they are of virtually no value to the data analyst. Under what conditions are we interested in rejecting the null hypothesis that the data are normally distributed? I have never come across a situation where a normal test is the right thing to do. When the sample size is small, even big departures from normality are not detected, and when your sample size is large, even the smallest deviation from normality will lead to a rejected null.

For example:

> set.seed(100)
> x <- rbinom(15,5,.6)
> shapiro.test(x)

    Shapiro-Wilk normality test

data:  x 
W = 0.8816, p-value = 0.0502

> x <- rlnorm(20,0,.4)
> shapiro.test(x)

    Shapiro-Wilk normality test

data:  x 
W = 0.9405, p-value = 0.2453

So, in both these cases (binomial and lognormal variates) the p-value is > 0.05 causing a failure to reject the null (that the data are normal). Does this mean we are to conclude that the data are normal? (hint: the answer is no). Failure to reject is not the same thing as accepting. This is hypothesis testing 101.

But what about larger sample sizes? Let's take the case where there the distribution is very nearly normal.

> library(nortest)
> x <- rt(500000,200)
> ad.test(x)

    Anderson-Darling normality test

data:  x 
A = 1.1003, p-value = 0.006975

> qqnorm(x)

enter image description here enter image description here

Here we are using a t-distribution with 200 degrees of freedom. The qq-plot shows the distribution is closer to normal than any distribution you are likely to see in the real world, but the test rejects normality with a very high degree of confidence.

Does the significant test against normality mean that we should not use normal theory statistics in this case? (another hint: the answer is no :) )

Generating random numbers with normal distribution in Excel

Take a loot at the Wikipedia article on random numbers as it talks about using sampling techniques. You can find the equation for your normal distribution by plugging into this one

pdf for normal distro

(equation via Wikipedia)

As for the second issue, go into Options under the circle Office icon, go to formulas, and change calculations to "Manual". That will maintain your sheet and not recalculate the formulas each time.

Converting a Uniform Distribution to a Normal Distribution

The standard Python library module random has what you want:

normalvariate(mu, sigma)
Normal distribution. mu is the mean, and sigma is the standard deviation.

For the algorithm itself, take a look at the function in random.py in the Python library.

The manual entry is here

col align right

For The Bootstrap 4+

This Code Worked Well for me

<div class="row">
        <div class="col">
            <div class="ml-auto">
                this content will be in the Right
            </div>
        </div>
        <div class="col mr-auto">
            <div class="mr-auto">
                this content will be in the leftt
            </div>
        </div>
    </div>

jQuery ajax success error

Try to set response dataType property directly:

dataType: 'text'

and put

die(''); 

in the end of your php file. You've got error callback cause jquery cannot parse your response. In anyway, you may use a "complete:" callback, just to make sure your request has been processed.

What does the 'Z' mean in Unix timestamp '120314170138Z'?

Yes. 'Z' stands for Zulu time, which is also GMT and UTC.

From http://en.wikipedia.org/wiki/Coordinated_Universal_Time:

The UTC time zone is sometimes denoted by the letter Z—a reference to the equivalent nautical time zone (GMT), which has been denoted by a Z since about 1950. The letter also refers to the "zone description" of zero hours, which has been used since 1920 (see time zone history). Since the NATO phonetic alphabet and amateur radio word for Z is "Zulu", UTC is sometimes known as Zulu time.

Technically, because the definition of nautical time zones is based on longitudinal position, the Z time is not exactly identical to the actual GMT time 'zone'. However, since it is primarily used as a reference time, it doesn't matter what area of Earth it applies to as long as everyone uses the same reference.

From wikipedia again, http://en.wikipedia.org/wiki/Nautical_time:

Around 1950, a letter suffix was added to the zone description, assigning Z to the zero zone, and A–M (except J) to the east and N–Y to the west (J may be assigned to local time in non-nautical applications; zones M and Y have the same clock time but differ by 24 hours: a full day). These were to be vocalized using a phonetic alphabet which pronounces the letter Z as Zulu, leading sometimes to the use of the term "Zulu Time". The Greenwich time zone runs from 7.5°W to 7.5°E longitude, while zone A runs from 7.5°E to 22.5°E longitude, etc.

Passing Objects By Reference or Value in C#

Lots of good answers had been added. I still want to contribute, might be it will clarify slightly more.

When you pass an instance as an argument to the method it passes the copy of the instance. Now, if the instance you pass is a value type(resides in the stack) you pass the copy of that value, so if you modify it, it won't be reflected in the caller. If the instance is a reference type you pass the copy of the reference(again resides in the stack) to the object. So you got two references to the same object. Both of them can modify the object. But if within the method body, you instantiate new object your copy of the reference will no longer refer to the original object, it will refer to the new object you just created. So you will end up having 2 references and 2 objects.

How to go from Blob to ArrayBuffer

You can use FileReader to read the Blob as an ArrayBuffer.

Here's a short example:

var arrayBuffer;
var fileReader = new FileReader();
fileReader.onload = function(event) {
    arrayBuffer = event.target.result;
};
fileReader.readAsArrayBuffer(blob);

Here's a longer example:

// ArrayBuffer -> Blob
var uint8Array  = new Uint8Array([1, 2, 3]);
var arrayBuffer = uint8Array.buffer;
var blob        = new Blob([arrayBuffer]);

// Blob -> ArrayBuffer
var uint8ArrayNew  = null;
var arrayBufferNew = null;
var fileReader     = new FileReader();
fileReader.onload  = function(event) {
    arrayBufferNew = event.target.result;
    uint8ArrayNew  = new Uint8Array(arrayBufferNew);

    // warn if read values are not the same as the original values
    // arrayEqual from: http://stackoverflow.com/questions/3115982/how-to-check-javascript-array-equals
    function arrayEqual(a, b) { return !(a<b || b<a); };
    if (arrayBufferNew.byteLength !== arrayBuffer.byteLength) // should be 3
        console.warn("ArrayBuffer byteLength does not match");
    if (arrayEqual(uint8ArrayNew, uint8Array) !== true) // should be [1,2,3]
        console.warn("Uint8Array does not match");
};
fileReader.readAsArrayBuffer(blob);
fileReader.result; // also accessible this way once the blob has been read

This was tested out in the console of Chrome 27—69, Firefox 20—60, and Safari 6—11.

Here's also a live demonstration which you can play with: https://jsfiddle.net/potatosalad/FbaM6/

Update 2018-06-23: Thanks to Klaus Klein for the tip about event.target.result versus this.result

Reference:

running a command as a super user from a python script

The safest way to do this is to prompt for the password beforehand and then pipe it into the command. Prompting for the password will avoid having the password saved anywhere in your code and it also won't show up in your bash history. Here's an example:

from getpass import getpass
from subprocess import Popen, PIPE

password = getpass("Please enter your password: ")
# sudo requires the flag '-S' in order to take input from stdin
proc = Popen("sudo -S apach2ctl restart".split(), stdin=PIPE, stdout=PIPE, stderr=PIPE)
# Popen only accepts byte-arrays so you must encode the string
proc.communicate(password.encode())

How to search contents of multiple pdf files?

You need some tools like pdf2text to first convert your pdf to a text file and then search inside the text. (You will probably miss some information or symbols).

If you are using a programming language there are probably pdf libraries written for this purpose. e.g. http://search.cpan.org/dist/CAM-PDF/ for Perl

How to count the number of occurrences of an element in a List

Sorry there's no simple method call that can do it. All you'd need to do though is create a map and count frequency with it.

HashMap<String,int> frequencymap = new HashMap<String,int>();
foreach(String a in animals) {
  if(frequencymap.containsKey(a)) {
    frequencymap.put(a, frequencymap.get(a)+1);
  }
  else{ frequencymap.put(a, 1); }
}

Custom Python list sorting

This does not work in Python 3.

You can use functools cmp_to_key to have old-style comparison functions work though.

from functools import cmp_to_key

def cmp_items(a, b):
    if a.foo > b.foo:
        return 1
    elif a.foo == b.foo:
        return 0
    else:
        return -1

cmp_items_py3 = cmp_to_key(cmp_items)

alist.sort(cmp_items_py3)

Converting a double to an int in C#

you can round your double and cast ist:

(int)Math.Round(myDouble);

How do I get bootstrap-datepicker to work with Bootstrap 3?

I also use Stefan Petre’s http://www.eyecon.ro/bootstrap-datepicker and it does not work with Bootstrap 3 without modification. Note that http://eternicode.github.io/bootstrap-datepicker/ is a fork of Stefan Petre's code.

You have to change your markup (the sample markup will not work) to use the new CSS and form grid layout in Bootstrap 3. Also, you have to modify some CSS and JavaScript in the actual bootstrap-datepicker implementation.

Here is my solution:

<div class="form-group row">
  <div class="col-xs-8">
    <label class="control-label">My Label</label>
    <div class="input-group date" id="dp3" data-date="12-02-2012" data-date-format="mm-dd-yyyy">
      <input class="form-control" type="text" readonly="" value="12-02-2012">
      <span class="input-group-addon"><i class="glyphicon glyphicon-calendar"></i></span>
    </div>
  </div>
</div>

CSS changes in datepicker.css on lines 176-177:

.input-group.date .input-group-addon i,
.input-group.date .input-group-addon i {

Javascript change in datepicker-bootstrap.js on line 34:

this.component = this.element.is('.date') ? this.element.find('.input-group-addon') : false;

UPDATE

Using the newer code from http://eternicode.github.io/bootstrap-datepicker/ the changes are as follows:

CSS changes in datepicker.css on lines 446-447:

.input-group.date .input-group-addon i,
.input-group.date .input-group-addon i {

Javascript change in datepicker-bootstrap.js on line 46:

 this.component = this.element.is('.date') ? this.element.find('.input-group-addon, .btn') : false;

Finally, the JavaScript to enable the datepicker (with some options):

 $(".input-group.date").datepicker({ autoclose: true, todayHighlight: true });

Tested with Bootstrap 3.0 and JQuery 1.9.1. Note that this fork is better to use than the other as it is more feature rich, has localization support and auto-positions the datepicker based on the control position and window size, avoiding the picker going off the screen which was a problem with the older version.

How to create a Jar file in Netbeans

Now (2020) NetBeans 11 does it automatically with the "Build" command (right click on the project's name and choose "Build")

How do I put an image into my picturebox using ImageLocation?

Setting the image using picture.ImageLocation() works fine, but you are using a relative path. Check your path against the location of the .exe after it is built.

For example, if your .exe is located at:

<project folder>/bin/Debug/app.exe

The image would have to be at:

<project folder>/bin/Image/1.jpg


Of course, you could just set the image at design-time (the Image property on the PictureBox property sheet).

If you must set it at run-time, one way to make sure you know the location of the image is to add the image file to your project. For example, add a new folder to your project, name it Image. Right-click the folder, choose "Add existing item" and browse to your image (be sure the file filter is set to show image files). After adding the image, in the property sheet set the Copy to Output Directory to Copy if newer.

At this point the image file will be copied when you build the application and you can use

picture.ImageLocation = @"Image\1.jpg"; 

Interface type check with Typescript

TypeGuards

interface MyInterfaced {
    x: number
}

function isMyInterfaced(arg: any): arg is MyInterfaced {
    return arg.x !== undefined;
}

if (isMyInterfaced(obj)) {
    (obj as MyInterfaced ).x;
}

How to make a phone call in android and come back to my activity when the call is done?

Steps:

1)Add the required permissions in the Manifest.xml file.

<!--For using the phone calls -->
<uses-permission android:name="android.permission.CALL_PHONE" />
<!--For reading phone call state-->
<uses-permission android:name="android.permission.READ_PHONE_STATE" />

2)Create a listener for the phone state changes.

public class EndCallListener extends PhoneStateListener {
@Override
public void onCallStateChanged(int state, String incomingNumber) {
    if(TelephonyManager.CALL_STATE_RINGING == state) {
    }
    if(TelephonyManager.CALL_STATE_OFFHOOK == state) {
        //wait for phone to go offhook (probably set a boolean flag) so you know your app initiated the call.
    }
    if(TelephonyManager.CALL_STATE_IDLE == state) {
        //when this state occurs, and your flag is set, restart your app
    Intent i = context.getPackageManager().getLaunchIntentForPackage(
                            context.getPackageName());
    //For resuming the application from the previous state
    i.addFlags(Intent.FLAG_ACTIVITY_SINGLE_TOP);

    //Uncomment the following if you want to restart the application instead of bring to front.
    //i.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
    context.startActivity(i);
    }
}
}

3)Initialize the listener in your OnCreate

EndCallListener callListener = new EndCallListener();
TelephonyManager mTM = (TelephonyManager)this.getSystemService(Context.TELEPHONY_SERVICE);
mTM.listen(callListener, PhoneStateListener.LISTEN_CALL_STATE);

but if you want to resume your application last state or to bring it back from the back stack, then replace FLAG_ACTIVITY_CLEAR_TOP with FLAG_ACTIVITY_SINGLE_TOP

Reference this Answer

What replaces cellpadding, cellspacing, valign, and align in HTML5 tables?

On particular table

_x000D_
_x000D_
<table style="border-collapse: separate; border-spacing: 10px;" >_x000D_
    <tr>_x000D_
      <td>Hi</td>_x000D_
      <td>Hello</td>_x000D_
    <tr/>_x000D_
    <tr>_x000D_
      <td>Hola</td>_x000D_
      <td>Oi!</td>_x000D_
    <tr/>_x000D_
</table>
_x000D_
_x000D_
_x000D_

Use LINQ to get items in one List<>, that are not in another List<>

Bit late to the party but a good solution which is also Linq to SQL compatible is:

List<string> list1 = new List<string>() { "1", "2", "3" };
List<string> list2 = new List<string>() { "2", "4" };

List<string> inList1ButNotList2 = (from o in list1
                                   join p in list2 on o equals p into t
                                   from od in t.DefaultIfEmpty()
                                   where od == null
                                   select o).ToList<string>();

List<string> inList2ButNotList1 = (from o in list2
                                   join p in list1 on o equals p into t
                                   from od in t.DefaultIfEmpty()
                                   where od == null
                                   select o).ToList<string>();

List<string> inBoth = (from o in list1
                       join p in list2 on o equals p into t
                       from od in t.DefaultIfEmpty()
                       where od != null
                       select od).ToList<string>();

Kudos to http://www.dotnet-tricks.com/Tutorial/linq/UXPF181012-SQL-Joins-with-C

Kotlin unresolved reference in IntelliJ

I had this problem because I was trying to set up a multiplatform library configurations.

I had deleted all the source sets with their dependencies from the "build.gradle" file but kept the "common" source set.

Native was working fine but the JVM was not able to build and showed your error.

In the end, the solution was to not delete the Source set of the JVM neither it's dependencies

Case statement in MySQL

Yes, something like this:

SELECT
    id,
    action_heading,
    CASE
        WHEN action_type = 'Income' THEN action_amount
        ELSE NULL
    END AS income_amt,
    CASE
        WHEN action_type = 'Expense' THEN action_amount
        ELSE NULL
    END AS expense_amt

FROM tbl_transaction;

As other answers have pointed out, MySQL also has the IF() function to do this using less verbose syntax. I generally try to avoid this because it is a MySQL-specific extension to SQL that isn't generally supported elsewhere. CASE is standard SQL and is much more portable across different database engines, and I prefer to write portable queries as much as possible, only using engine-specific extensions when the portable alternative is considerably slower or less convenient.

Pandas unstack problems: ValueError: Index contains duplicate entries, cannot reshape

There's a far more simpler solution to tackle this.

The reason why you get ValueError: Index contains duplicate entries, cannot reshape is because, once you unstack "Location", then the remaining index columns "id" and "date" combinations are no longer unique.

You can avoid this by retaining the default index column (row #) and while setting the index using "id", "date" and "location", add it in "append" mode instead of the default overwrite mode.

So use,

e.set_index(['id', 'date', 'location'], append=True)

Once this is done, your index columns will still have the default index along with the set indexes. And unstack will work.

Let me know how it works out.

Submit form using a button outside the <form> tag

A solution that works great for me, is still missing here. It requires having a visually hidden <submit> or <input type="submit"> element whithin the <form>, and an associated <label> element outside of it. It would look like this:

<form method="get" action="something.php">
     <input type="text" name="name" />
     <input type="submit" id="submit-form" class="hidden" />
</form>

<label for="submit-form" tabindex="0">Submit</label>

Now this link enables you to 'click' the form <submit> element by clicking the <label> element.

How to create a JPA query with LEFT OUTER JOIN

Write this;

 SELECT f from Student f LEFT JOIN f.classTbls s WHERE s.ClassName = 'abc'

Because your Student entity has One To Many relationship with ClassTbl entity.

What happens if you mount to a non-empty mount point with fuse?

You need to make sure that the files on the device mounted by fuse will not have the same paths and file names as files which already existing in the nonempty mountpoint. Otherwise this would lead to confusion. If you are sure, pass -o nonempty to the mount command.

You can try what is happening using the following commands.. (Linux rocks!) .. without destroying anything..

// create 10 MB file 
dd if=/dev/zero of=partition bs=1024 count=10240

// create loopdevice from that file
sudo losetup /dev/loop0 ./partition

// create  filesystem on it
sudo e2mkfs.ext3 /dev/loop0

// mount the partition to temporary folder and create a file
mkdir test
sudo mount -o loop /dev/loop0 test
echo "bar" | sudo tee test/foo

# unmount the device
sudo umount /dev/loop0

# create the file again
echo "bar2" > test/foo

# now mount the device (having file with same name on it) 
# and see what happens
sudo mount -o loop /dev/loop0 test

Redirect to an external URL from controller action in Spring MVC

For external url you have to use "http://www.yahoo.com" as the redirect url.

This is explained in the redirect: prefix of Spring reference documentation.

redirect:/myapp/some/resource

will redirect relative to the current Servlet context, while a name such as

redirect:http://myhost.com/some/arbitrary/path

will redirect to an absolute URL

C++ where to initialize static const

Since C++17 the inline specifier also applies to variables. You can now define static member variables in the class definition:

#include <string>

class foo {
public:
   foo();
   foo( int );
private:
   inline static const std::string s { "foo" };
};

SQLSTATE[HY000] [2002] php_network_getaddresses: getaddrinfo failed: Name or service not known

In my case, it had absolute nothing to do with network issues.

I had been using my local laravel testing environment using laradock. Because laradock runs the mysql server in a different container, you have to set your mysql host in the .env file to the name of the docker mysql container, which by default is mysql.

When I switched back to using homestead, it was trying to connect to a host named mysql, when in fact is should be looking on localhost.

What a DUH moment!

Download and install an ipa from self hosted url on iOS

Yes, safari will detect the *.ipa and will try to install it, but the ipa needs to be correctly signed and only allowed devices would be able to install it.

http://www.diawi.com is a service that will help you with this process.

All of this is for Ad-hoc distribution, not for production apps.

More information on below link : Is there a way to install iPhone App via browser?

Resource interpreted as Document but transferred with MIME type application/zip

I solved the problem by adding target="_blank" to the link. With this, chrome opens a new tab and loads the PDF without warning even in responsive mode.

how to show progress bar(circle) in an activity having a listview before loading the listview with data

Create an xml file any name (say progressBar.xml) in drawable and add <color name="silverGrey">#C0C0C0</color> in color.xml.

<?xml version="1.0" encoding="utf-8"?>
<rotate xmlns:android="http://schemas.android.com/apk/res/android"
    android:fromDegrees="0"
    android:pivotX="50%"
    android:pivotY="50%"
    android:toDegrees="720" >

    <shape
        android:innerRadiusRatio="3"
        android:shape="ring"
        android:thicknessRatio="6"
        android:useLevel="false" >
        <size
            android:height="200dip"
            android:width="300dip" />

        <gradient
            android:angle="0"
            android:endColor="@color/silverGrey"
            android:startColor="@android:color/transparent"
            android:type="sweep"
            android:useLevel="false" />

    </shape>
</rotate>

Now in your xml file where you have your listView add this code:

 <ListView
            android:id="@+id/list_form_statusMain"
            android:layout_width="match_parent"
            android:layout_height="wrap_content">
        </ListView>

        <ProgressBar
            android:id="@+id/progressBar"
            style="@style/CustomAlertDialogStyle"
            android:layout_width="60dp"
            android:layout_height="60dp"
            android:layout_centerInParent="true"
            android:layout_gravity="center_horizontal"
            android:indeterminate="true"
            android:indeterminateDrawable="@drawable/circularprogress"
            android:visibility="gone"
            android:layout_centerHorizontal="true"
            android:layout_centerVertical="true"/>

In AsyncTask in the method:

@Override
protected void onPreExecute()
{
    progressbar_view.setVisibility(View.VISIBLE);

    // your code
}

And in onPostExecute:

@Override
protected void onPostExecute(String s)
{
    progressbar_view.setVisibility(View.GONE);

    //your code
}

How to scroll the page when a modal dialog is longer than the screen?

I wanted to add my pure CSS answer to this problem of modals with dynamic width and height. The following code also works with the following requirements:

  1. Place modal in center of screen
  2. If modal is higher than viewport, scroll dimmer (not modal content)

HTML:

<div class="modal">
    <div class="modal__content">
        (Long) Content
    </div>
</div>

CSS/LESS:

.modal {
    position: fixed;
    display: flex;
    align-items: center;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    padding: @qquad;
    overflow-y: auto;
    background: rgba(0, 0, 0, 0.7);
    z-index: @zindex-modal;

    &__content {
        width: 900px;
        margin: auto;
        max-width: 90%;
        padding: @quad;
        background: white;
        box-shadow: 0 0 5px 0 rgba(0, 0, 0, 0.75);
    }
}

This way the modal is always within the viewport. The width and height of the modal are as flexible as you like. I removed my close icon from this for simplicity.

How to upload files to server using Putty (ssh)

"C:\Program Files\PuTTY\pscp.exe" -scp file.py server.com:

file.py will be uploaded into your HOME dir on remote server.

or when the remote server has a different user, use "C:\Program Files\PuTTY\pscp.exe" -l username -scp file.py server.com:

After connecting to the server pscp will ask for a password.

using facebook sdk in Android studio

People using Android Studio 0.8.6 could do these:

  1. Download Facebook-android-sdk-xxx.zip & Unzip it
  2. Copy ONLY facebook dir under the Facebook-android-sdk-xxx dir into your project along with app/

    • ImAnApp/
      • |-- app/
      • |-- build/
      • |-- facebook/
  3. Now you should see Android Studio showing facebook as module

  4. Modify the build.gradle of facebook into this.
    • provided files('../libs/bolts.jar') to provided files('./libs/bolts.jar')
    • compileSdkVersion Integer.parseInt(project.ANDROID_BUILD_SDK_VERSION) to compileSdkVersion 20 or other version you defined in the app
    • buildToolsVersion project.ANDROID_BUILD_TOOLS_VERSION to buildToolsVersion '20.0.0'
    • minSdkVersion Integer.parseInt(project.ANDROID_BUILD_MIN_SDK_VERSION) to minSdkVersion 14
    • targetSdkVersion Integer.parseInt(project.ANDROID_BUILD_TARGET_SDK_VERSION) to targetSdkVersion 20

    apply plugin: 'android-library'

    dependencies {
        compile 'com.android.support:support-v4:19.1.+'
        provided files('./libs/bolts.jar')
    }

    android {
        compileSdkVersion 20
        buildToolsVersion '20.0.0'

        defaultConfig {
            minSdkVersion 14
            targetSdkVersion 20
        }

        lintOptions {
            abortOnError false
        }

        sourceSets {
            main {
                manifest.srcFile 'AndroidManifest.xml'
                java.srcDirs = ['src']
                res.srcDirs = ['res']
            }
        }
    }

Resync your gradle file & it should just work fine!

Angular 4: no component factory found,did you add it to @NgModule.entryComponents?

if you use routing in your application

make sure Add new components into the routing path

for example :

    const appRoutes: Routes = [
  { path: '', component: LoginComponent },
  { path: 'home', component: HomeComponent },
  { path: 'fundList',      component: FundListComponent },
];

What does the "More Columns than Column Names" error mean?

Depending on the data (e.g. tsv extension) it may use tab as separators, so you may try sep = '\t' with read.csv.

window.history.pushState refreshing the browser

window.history.pushState({urlPath:'/page1'},"",'/page1')

Only works after page is loaded, and when you will click on refresh it doesn't mean that there is any real URL.

What you should do here is knowing to which URL you are getting redirected when you reload this page. And on that page you can get the conditions by getting the current URL and making all of your conditions.

How to pass boolean parameter value in pipeline to downstream jobs?

Things are much easier nowadays: the builtin Snippet Generator supports the 'build' step (I don't know since when though).

Laravel Request::all() Should Not Be Called Statically

The facade is another Request class, access it with the full path:

$input = \Request::all();

From laravel 5 you can also access it through the request() function:

$input = request()->all();

Add some word to all or some rows in Excel?

  1. Insert a column left to the column in question(adding column A beside column B).
  2. Provide the value you want to append in 1st cell of column A
  3. Insert a column right to the column in question ( column C)
  4. Add this formula -> =CONCATENATE("A1","B1")
  5. Drag it down to apply to all values in column
  6. You will find concatenated values in column C

This worked for me !

Variable used in lambda expression should be final or effectively final

if it is not necessary to modify the variable than a general workaround for this kind of problem would be to extract the part of code which use lambda and use final keyword on method-parameter.

Best way to check for null values in Java?

If you control the API being called, consider using Guava's Optional class

More info here. Change your method to return an Optional<Boolean> instead of a Boolean.

This informs the calling code that it must account for the possibility of null, by calling one of the handy methods in Optional

How do I use ROW_NUMBER()?

This query:

SELECT ROW_NUMBER() OVER(ORDER BY UserId) From Users WHERE UserName='Joe'

will return all rows where the UserName is 'Joe' UNLESS you have no UserName='Joe'

They will be listed in order of UserID and the row_number field will start with 1 and increment however many rows contain UserName='Joe'

If it does not work for you then your WHERE command has an issue OR there is no UserID in the table. Check spelling for both fields UserID and UserName.

Opening a SQL Server .bak file (Not restoring!)

From SQL Server 2008 SSMS (SQL Server Management Studio), simply:

  1. Connect to your database instance (for example, "localhost\sqlexpress")
  2. Either:

    • a) Select the database you want to restore to; or, alternatively
    • b) Just create a new, empty database to restore to.
  3. Right-click, Tasks, Restore, Database

  4. Device, [...], Add, Browse to your .bak file
  5. Select the backup.
    Choose "overwrite=Y" under options.
    Restore the database
  6. It should say "100% complete", and your database should be on-line.

PS: Again, I emphasize: you can easily do this on a "scratch database" - you do not need to overwrite your current database. But you do need to RESTORE.

PPS: You can also accomplish the same thing with T-SQL commands, if you wished to script it.

Change a Git remote HEAD to point to something besides master

Simple just log into your GitHub account and on the far right side in the navigation menu choose Settings, in the Settings Tab choose Default Branch and return back to main page of your repository that did the trick for me.

Add back button to action bar

Firstly Use this:

ActionBar bar = getSupportActionBar();
bar.setDisplayHomeAsUpEnabled(true);

Then set operation of button click in onOptionsItemSelected method

 @Override
 public boolean onOptionsItemSelected(MenuItem item) {
    switch (item.getItemId()) {
        case android.R.id.home:
         finish();
        return true;
     default:
        return super.onOptionsItemSelected(item);
  }
 }

How to use CSS to surround a number with a circle?

the easiest way is using bootstrap and badge class

 <span class="badge">1</span>

How do I use Bash on Windows from the Visual Studio Code integrated terminal?

Add the Git\bin directory to the Path environment variable. The directory is %ProgramFiles%\Git\bin by default. By this way you can access Git Bash with simply typing bash in every terminal including the integrated terminal of Visual Studio Code.

How to set the path and environment variables in Windows

What does iterator->second mean?

The type of the elements of an std::map (which is also the type of an expression obtained by dereferencing an iterator of that map) whose key is K and value is V is std::pair<const K, V> - the key is const to prevent you from interfering with the internal sorting of map values.

std::pair<> has two members named first and second (see here), with quite an intuitive meaning. Thus, given an iterator i to a certain map, the expression:

i->first

Which is equivalent to:

(*i).first

Refers to the first (const) element of the pair object pointed to by the iterator - i.e. it refers to a key in the map. Instead, the expression:

i->second

Which is equivalent to:

(*i).second

Refers to the second element of the pair - i.e. to the corresponding value in the map.

Unmount the directory which is mounted by sshfs in Mac

The following worked for me:

hdiutil detach <path to sshfs mount>

Example:

hdiutil detach /Users/user1/sshfs

One can also locate the volume created by sshfs in Finder, right-click, and select Eject. Which is, to the best of my knowledge, the GUI version of the above command.

The project description file (.project) for my project is missing

I had the same problem, and I haven't gotten that error since I close the project before I close myEclipse and don't tidy up the default location.

My project source and compiled files are outside the default workspace but there are stubb folders created by default by myEclipse in the default workspace. When I setup the project, there are two .project files - one in the default workspace that points to the working dir, and one .project in my chosen directory.

How to generate Javadoc from command line

Oracle provides some simple examples:

http://docs.oracle.com/javase/8/docs/technotes/tools/windows/javadoc.html#CHDJBGFC

Assuming you are in ~/ and the java source tree is in ./saxon_source/net and you want to recurse through the whole source tree net is both a directory and the top package name.

mkdir saxon_docs
javadoc -d saxon_docs -sourcepath saxon_source -subpackages net

How to call a php script/function on a html button click

Of course AJAX is the solution,

To perform an AJAX request (for easiness we can use jQuery library).

Step1.

Include jQuery library in your web page

a. you can download jQuery library from jquery.com and keep it locally.

b. or simply paste the following code,

<script src="http://ajax.googleapis.com/ajax/libs/jquery/1.11.2/jquery.min.js"></script>

Step 2.

Call a javascript function on button click

<button type="button" onclick="foo()">Click Me</button>

Step 3.

and finally the function

 function foo () {
      $.ajax({
        url:"test.php", //the page containing php script
        type: "POST", //request type
        success:function(result){
         alert(result);
       }
     });
 }

it will make an AJAX request to test.php when ever you clicks the button and alert the response.

For example your code in test.php is,

<?php echo 'hello'; ?>

then it will alert "hello" when ever you clicks the button.

Pass parameter to EventHandler

If I understand your problem correctly, you are calling a method instead of passing it as a parameter. Try the following:

myTimer.Elapsed += PlayMusicEvent;

where

public void PlayMusicEvent(object sender, ElapsedEventArgs e)
{
    music.player.Stop();
    System.Timers.Timer myTimer = (System.Timers.Timer)sender;
    myTimer.Stop();
}

But you need to think about where to store your note.

How to delete all records from table in sqlite with Android?

this metod delate all data from database

 public void deleteAll()
{
    SQLiteDatabase db = this.getWritableDatabase();
    db.execSQL("delete from "+ TABLE_NAME);
    db.close();
}

How to make a button redirect to another page using jQuery or just Javascript

Without script:

<form action="where-you-want-to-go"><input type="submit"></form>

Better yet, since you are just going somewhere, present the user with the standard interface for "just going somewhere":

<a href="where-you-want-to-go">ta da</a>

Although, the context sounds like "Simulate a normal search where the user submits a form", in which case the first option is the way to go.

Create a Dropdown List for MVC3 using Entity Framework (.edmx Model) & Razor Views && Insert A Database Record to Multiple Tables

Well, actually I'll have to say David is right with his solution, but there are some topics disturbing me:

  1. You should never send your model to the view => This is correct
  2. If you create a ViewModel, and include the Model as member in the ViewModel, then you effectively sent your model to the View => this is BAD
  3. Using dictionaries to send the options to the view => this not good style

So how can you create a better coupling?

I would use a tool like AutoMapper or ValueInjecter to map between ViewModel and Model. AutoMapper does seem to have the better syntax and feel to it, but the current version lacks a very severe topic: It is not able to perform the mapping from ViewModel to Model (under certain circumstances like flattening, etc., but this is off topic) So at present I prefer to use ValueInjecter.

So you create a ViewModel with the fields you need in the view. You add the SelectList items you need as lookups. And you add them as SelectLists already. So you can query from a LINQ enabled sourc, select the ID and text field and store it as a selectlist: You gain that you do not have to create a new type (dictionary) as lookup and you just move the new SelectList from the view to the controller.

  // StaffTypes is an IEnumerable<StaffType> from dbContext
  // viewModel is the viewModel initialized to copy content of Model Employee  
  // viewModel.StaffTypes is of type SelectList

  viewModel.StaffTypes =
    new SelectList(
        StaffTypes.OrderBy( item => item.Name )
        "StaffTypeID",
        "Type",
        viewModel.StaffTypeID
    );

In the view you just have to call

@Html.DropDownListFor( model => mode.StaffTypeID, model.StaffTypes )

Back in the post element of your method in the controller you have to take a parameter of the type of your ViewModel. You then check for validation. If the validation fails, you have to remember to re-populate the viewModel.StaffTypes SelectList, because this item will be null on entering the post function. So I tend to have those population things separated into a function. You just call back return new View(viewModel) if anything is wrong. Validation errors found by MVC3 will automatically be shown in the view.

If you have your own validation code you can add validation errors by specifying which field they belong to. Check documentation on ModelState to get info on that.

If the viewModel is valid you have to perform the next step:

If it is a create of a new item, you have to populate a model from the viewModel (best suited is ValueInjecter). Then you can add it to the EF collection of that type and commit changes.

If you have an update, you get the current db item first into a model. Then you can copy the values from the viewModel back to the model (again using ValueInjecter gets you do that very quick). After that you can SaveChanges and are done.

Feel free to ask if anything is unclear.

Converting file size in bytes to human-readable string

Here's one I wrote:

_x000D_
_x000D_
/**
 * Format bytes as human-readable text.
 * 
 * @param bytes Number of bytes.
 * @param si True to use metric (SI) units, aka powers of 1000. False to use 
 *           binary (IEC), aka powers of 1024.
 * @param dp Number of decimal places to display.
 * 
 * @return Formatted string.
 */
function humanFileSize(bytes, si=false, dp=1) {
  const thresh = si ? 1000 : 1024;

  if (Math.abs(bytes) < thresh) {
    return bytes + ' B';
  }

  const units = si 
    ? ['kB', 'MB', 'GB', 'TB', 'PB', 'EB', 'ZB', 'YB'] 
    : ['KiB', 'MiB', 'GiB', 'TiB', 'PiB', 'EiB', 'ZiB', 'YiB'];
  let u = -1;
  const r = 10**dp;

  do {
    bytes /= thresh;
    ++u;
  } while (Math.round(Math.abs(bytes) * r) / r >= thresh && u < units.length - 1);


  return bytes.toFixed(dp) + ' ' + units[u];
}


console.log(humanFileSize(1551859712))  // 1.4 GiB
console.log(humanFileSize(5000, true))  // 5.0 kB
console.log(humanFileSize(5000, false))  // 4.9 KiB
console.log(humanFileSize(-10000000000000000000000000000))  // -8271.8 YiB
console.log(humanFileSize(999949, true))  // 999.9 kB
console.log(humanFileSize(999950, true))  // 1.0 MB
console.log(humanFileSize(999950, true, 2))  // 999.95 kB
console.log(humanFileSize(999500, true, 0))  // 1 MB
_x000D_
_x000D_
_x000D_

RegEx for valid international mobile phone number

// Regex - Check Singapore valid mobile numbers

public static boolean isSingaporeMobileNo(String str) {
    Pattern mobNO = Pattern.compile("^(((0|((\\+)?65([- ])?))|((\\((\\+)?65\\)([- ])?)))?[8-9]\\d{7})?$");
    Matcher matcher = mobNO.matcher(str);
    if (matcher.find()) {
        return true;
    } else {
        return false;
    }
}

mysql select from n last rows

because it is autoincrement, here's my take:

Select * from tbl 
where certainconditionshere 
and autoincfield >= (select max(autoincfield) from tbl) - $n

Method with a bool return

private bool CheckAll()
{
    if ( ....)
    {
        return true;
    }

    return false;
}

When the if-condition is false the method doesn't know what value should be returned (you probably get an error like "not all paths return a value").

As CQQL pointed out if you mean to return true when your if-condition is true you could have simply written:

private bool CheckAll()
{
    return (your_condition);
}

If you have side effects, and you want to handle them before you return, the first (long) version would be required.

Correct way of getting Client's IP Addresses from http.Request

Looking at http.Request you can find the following member variables:

// HTTP defines that header names are case-insensitive.
// The request parser implements this by canonicalizing the
// name, making the first character and any characters
// following a hyphen uppercase and the rest lowercase.
//
// For client requests certain headers are automatically
// added and may override values in Header.
//
// See the documentation for the Request.Write method.
Header Header

// RemoteAddr allows HTTP servers and other software to record
// the network address that sent the request, usually for
// logging. This field is not filled in by ReadRequest and
// has no defined format. The HTTP server in this package
// sets RemoteAddr to an "IP:port" address before invoking a
// handler.
// This field is ignored by the HTTP client.
RemoteAddr string

You can use RemoteAddr to get the remote client's IP address and port (the format is "IP:port"), which is the address of the original requestor or the last proxy (for example a load balancer which lives in front of your server).

This is all you have for sure.

Then you can investigate the headers, which are case-insensitive (per documentation above), meaning all of your examples will work and yield the same result:

req.Header.Get("X-Forwarded-For") // capitalisation
req.Header.Get("x-forwarded-for") // doesn't
req.Header.Get("X-FORWARDED-FOR") // matter

This is because internally http.Header.Get will normalise the key for you. (If you want to access header map directly, and not through Get, you would need to use http.CanonicalHeaderKey first.)

Finally, "X-Forwarded-For" is probably the field you want to take a look at in order to grab more information about client's IP. This greatly depends on the HTTP software used on the remote side though, as client can put anything in there if it wishes to. Also, note the expected format of this field is the comma+space separated list of IP addresses. You will need to parse it a little bit to get a single IP of your choice (probably the first one in the list), for example:

// Assuming format is as expected
ips := strings.Split("10.0.0.1, 10.0.0.2, 10.0.0.3", ", ")
for _, ip := range ips {
    fmt.Println(ip)
}

will produce:

10.0.0.1
10.0.0.2
10.0.0.3

Error: org.springframework.web.HttpMediaTypeNotSupportedException: Content type 'text/plain;charset=UTF-8' not supported

Building on what is mentioned in the comments, the simplest solution would be:

@RequestMapping(method = RequestMethod.PUT, consumes = MediaType.APPLICATION_JSON_VALUE)
@ResponseBody
public Collection<BudgetDTO> updateConsumerBudget(@RequestBody SomeDto someDto) throws GeneralException, ParseException {

    //whatever

}

class SomeDto {

   private List<WhateverBudgerPerDateDTO> budgetPerDate;


  //getters setters
}

The solution assumes that the HTTP request you are creating actually has

Content-Type:application/json instead of text/plain

Transfer data between databases with PostgreSQL

You can not perform a cross-database query like SQL Server; PostgreSQL does not support this.

The DbLink extension of PostgreSQL is used to connect one database to another database. You have install and configure DbLink to execute a cross-database query.

I have already created a step-by-step script and example for executing cross database query in PostgreSQL. Please visit this post: PostgreSQL [Video]: Cross Database Queries using the DbLink Extension

Double.TryParse or Convert.ToDouble - which is faster and safer?

To start with, I'd use double.Parse rather than Convert.ToDouble in the first place.

As to whether you should use Parse or TryParse: can you proceed if there's bad input data, or is that a really exceptional condition? If it's exceptional, use Parse and let it blow up if the input is bad. If it's expected and can be cleanly handled, use TryParse.

What is the difference between PUT, POST and PATCH?

PUT = replace the ENTIRE RESOURCE with the new representation provided

PATCH = replace parts of the source resource with the values provided AND|OR other parts of the resource are updated that you havent provided (timestamps) AND|OR updating the resource effects other resources (relationships)

https://laracasts.com/discuss/channels/general-discussion/whats-the-differences-between-put-and-patch?page=1

What is the difference between compare() and compareTo()?

Employee Table
Name, DoB, Salary
Tomas , 2/10/1982, 300
Daniel , 3/11/1990, 400
Kwame , 2/10/1998, 520

The Comparable interface allows you to sort a list of objects eg Employees with reference to one primary field – for instance, you could sort by name or by salary with the CompareTo() method

emp1.getName().compareTo(emp2.getName())

A more flexible interface for such requirements is provided by the Comparator interface, whose only method is compare()

public interface Comparator<Employee> {
 int compare(Employee obj1, Employee obj2);
}

Sample code

public class NameComparator implements Comparator<Employee> {

public int compare(Employee e1, Employee e2) {
     // some conditions here
        return e1.getName().compareTo(e2.getName()); // returns 1 since (T)omas > (D)an 
    return e1.getSalary().compareTo(e2.getSalary()); // returns -1 since 400 > 300
}

}

What character represents a new line in a text area

By HTML specifications, browsers are required to canonicalize line breaks in user input to CR LF (\r\n), and I don’t think any browser gets this wrong. Reference: clause 17.13.4 Form content types in the HTML 4.01 spec.

In HTML5 drafts, the situation is more complicated, since they also deal with the processes inside a browser, not just the data that gets sent to a server-side form handler when the form is submitted. According to them (and browser practice), the textarea element value exists in three variants:

  1. the raw value as entered by the user, unnormalized; it may contain CR, LF, or CR LF pair;
  2. the internal value, called “API value”, where line breaks are normalized to LF (only);
  3. the submission value, where line breaks are normalized to CR LF pairs, as per Internet conventions.

Can comments be used in JSON?

If you are using Jackson as your JSON parser then this is how you enable it to allow comments:

ObjectMapper mapper = new ObjectMapper().configure(Feature.ALLOW_COMMENTS, true);

Then you can have comments like this:

{
  key: "value" // Comment
}

And you can also have comments starting with # by setting:

mapper.configure(Feature.ALLOW_YAML_COMMENTS, true);

But in general (as answered before) the specification does not allow comments.

Returning JSON response from Servlet to Javascript/JSP page

Got it working! I should have been building a JSONArray of JSONObjects and then add the array to a final "Addresses" JSONObject. Observe the following:

JSONObject json      = new JSONObject();
JSONArray  addresses = new JSONArray();
JSONObject address;
try
{
   int count = 15;

   for (int i=0 ; i<count ; i++)
   {
       address = new JSONObject();
       address.put("CustomerName"     , "Decepticons" + i);
       address.put("AccountId"        , "1999" + i);
       address.put("SiteId"           , "1888" + i);
       address.put("Number"            , "7" + i);
       address.put("Building"          , "StarScream Skyscraper" + i);
       address.put("Street"            , "Devestator Avenue" + i);
       address.put("City"              , "Megatron City" + i);
       address.put("ZipCode"          , "ZZ00 XX1" + i);
       address.put("Country"           , "CyberTron" + i);
       addresses.add(address);
   }
   json.put("Addresses", addresses);
}
catch (JSONException jse)
{ 

}
response.setContentType("application/json");
response.getWriter().write(json.toString());

This worked and returned valid and parse-able JSON. Hopefully this helps someone else in the future. Thanks for your help Marcel

How to beautify JSON in Python?

Try underscore-cli:

cat myfile.json | underscore print --color

It's a pretty nifty tool that can elegantly do a lot of manipulation of structured data, execute js snippets, fill templates, etc. It's ridiculously well documented, polished, and ready for serious use. And I wrote it. :)

Download multiple files with a single action

To improve on @Dmitry Nogin's answer: this worked in my case.

However, it's not tested, since I am not sure how the file dialogue works on various OS/browser combinations. (Thus community wiki.)

<script>
$('#download').click(function () {
    download(['http://www.arcelormittal.com/ostrava/doc/cv.doc', 
              'http://www.arcelormittal.com/ostrava/doc/cv.doc']);
});

var download = function (ar) {
    var prevfun=function(){};
    ar.forEach(function(address) {  
        var pp=prevfun;
        var fun=function() {
                var iframe = $('<iframe style="visibility: collapse;"></iframe>');
                $('body').append(iframe);
                var content = iframe[0].contentDocument;
                var form = '<form action="' + address + '" method="POST"></form>';
                content.write(form);
                $(form).submit();
                setTimeout(function() {    
                    $(document).one('mousemove', function() { //<--slightly hacky!
                        iframe.remove();
                        pp();
                    });
                },2000);
        }
        prevfun=fun; 
      });
      prevfun();   
}
</script>

Is there a way to retrieve the view definition from a SQL Server using plain ADO?

You can get table/view details through below query.

For table :sp_help table_name For View :sp_help view_name

Linq with group by having count

Like this:

from c in db.Company
group c by c.Name into grp
where grp.Count() > 1
select grp.Key

Or, using the method syntax:

Company
    .GroupBy(c => c.Name)
    .Where(grp => grp.Count() > 1)
    .Select(grp => grp.Key);

Adding Only Untracked Files

git add . (add all files in this directory)

git add -all (add all files in all directories)

git add -N can be helpful for for listing which ones for later....

set font size in jquery

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

How do I print out the contents of a vector?

A much easier way to do this is with the standard copy algorithm:

#include <iostream>
#include <algorithm> // for copy
#include <iterator> // for ostream_iterator
#include <vector>

int main() {
    /* Set up vector to hold chars a-z */
    std::vector<char> path;
    for (int ch = 'a'; ch <= 'z'; ++ch)
        path.push_back(ch);

    /* Print path vector to console */
    std::copy(path.begin(), path.end(), std::ostream_iterator<char>(std::cout, " "));

    return 0;
}

The ostream_iterator is what's called an iterator adaptor. It is templatized over the type to print out to the stream (in this case, char). cout (aka console output) is the stream we want to write to, and the space character (" ") is what we want printed between each element stored in the vector.

This standard algorithm is powerful and so are many others. The power and flexibility the standard library gives you are what make it so great. Just imagine: you can print a vector to the console with just one line of code. You don't have to deal with special cases with the separator character. You don't need to worry about for-loops. The standard library does it all for you.

Split pandas dataframe in two if it has more than 10 rows

There is no specific convenience function.

You'd have to do something like:

first_ten = pd.DataFrame()
rest = pd.DataFrame()

if df.shape[0] > 10: # len(df) > 10 would also work
    first_ten = df[:10]
    rest = df[10:]

Is bool a native C type?

bool exists in the current C - C99, but not in C89/90.

In C99 the native type is actually called _Bool, while bool is a standard library macro defined in stdbool.h (which expectedly resolves to _Bool). Objects of type _Bool hold either 0 or 1, while true and false are also macros from stdbool.h.

Note, BTW, that this implies that C preprocessor will interpret #if true as #if 0 unless stdbool.h is included. Meanwhile, C++ preprocessor is required to natively recognize true as a language literal.

Get the Id of current table row with Jquery

$('#tblCart tr').click(function () {
        var tr_id = $(this).attr('id'); 
        alert(tr_id );
    });



<table class="table table-striped table-bordered table-hover" id="tblCart" cellspacing="0" align="center" >
                <tr>
                    <th>
                        @Html.DisplayNameFor(model => model.Item.ItemName)
                    </th>
                    <th>
                        @Html.DisplayNameFor(model => model.Price.PriceAmount)
                    </th>
                    <th>
                        @Html.DisplayNameFor(model => model.Quantity)
                    </th>
                    <th>
                        @Html.DisplayNameFor(model => model.Subtotal)
                    </th>
                    <th></th>
                </tr>

               @if (cart != null)
               {
                   foreach (var vm in cart)
                   {
                    <tr id="@vm.Id">
                        <td>
                            @Html.DisplayFor(modelItem => vm.Item.ItemName)
                        </td>
                        <td>
                            @Html.DisplayFor(modelItem => vm.Price.PriceAmount)
                        </td>
                        <td>
                            @Html.DisplayFor(modelItem => vm.Quantity)
                        </td>
                        <td>
                            @Html.DisplayFor(modelItem => vm.Subtotal)
                        </td>
                        <td >                            
                            <span style="width:80px; text-align:center;" class="glyphicon glyphicon-minus-sign" />                        
                        </td>
                    </tr>  
                   }
               }
            </table>

What does <![CDATA[]]> in XML mean?

It escapes a string that cannot be passed to XML as usual:

Example:

The string contains "&" in it.

You can not:

<FL val="Company Name">Dolce & Gabbana</FL>

Therefore, you must use CDATA:

<FL val="Company Name"> <![CDATA["Dolce & Gabbana"]]> </FL>

Background image jumps when address bar hides iOS/Android/Mobile Chrome

I found that Jason's answer wasn't quite working for me and I was still getting a jump. The Javascript ensured there was no gap at the top of the page but the background was still jumping whenever the address bar disappeared/reappeared. So as well as the Javascript fix, I applied transition: height 999999s to the div. This creates a transition with a duration so long that it virtually freezes the element.

Passing arguments to an interactive program non-interactively

You can also use printf to pipe the input to your script.

var=val
printf "yes\nno\nmaybe\n$var\n" | ./your_script.sh

How do I shutdown, restart, or log off Windows via a bat file?

The most common ways to use the shutdown command are:

  • shutdown -s — Shuts down.
  • shutdown -r — Restarts.
  • shutdown -l — Logs off.
  • shutdown -h — Hibernates.

    Note: There is a common pitfall wherein users think -h means "help" (which it does for every other command-line program... except shutdown.exe, where it means "hibernate"). They then run shutdown -h and accidentally turn off their computers. Watch out for that.

  • shutdown -i — "Interactive mode". Instead of performing an action, it displays a GUI dialog.

  • shutdown -a — Aborts a previous shutdown command.

The commands above can be combined with these additional options:

  • -f — Forces programs to exit. Prevents the shutdown process from getting stuck.
  • -t <seconds> — Sets the time until shutdown. Use -t 0 to shutdown immediately.
  • -c <message> — Adds a shutdown message. The message will end up in the Event Log.
  • -y — Forces a "yes" answer to all shutdown queries.

    Note: This option is not documented in any official documentation. It was discovered by these StackOverflow users.


I want to make sure some other really good answers are also mentioned along with this one. Here they are in no particular order.

MySQL Data Source not appearing in Visual Studio

i install mysql for visual studio and the problem simply solved.although version of my visual studio is 2012!

SSH SCP Local file to Remote in Terminal Mac Os X

Just to clarify the answer given by JScoobyCed, the scp command cannot copy files to directories that require administrative permission. However, you can use the scp command to copy to directories that belong to the remote user.

So, to copy to a directory that requires root privileges, you must first copy that file to a directory belonging to the remote user using the scp command. Next, you must login to the remote account using ssh. Once logged in, you can then move the file to the directory of your choosing by using the sudo mv command. In short, the commands to use are as follows:

Using scp, copy file to a directory in the remote user's account, for example the Documents directory:

scp /path/to/your/local/file remoteUser@some_address:/home/remoteUser/Documents

Next, login to the remote user's account using ssh and then move the file to a restricted directory using sudo:

ssh remoteUser@some_address
sudo mv /home/remoteUser/Documents/file /var/www

WCF timeout exception detailed investigation

from: http://www.codeproject.com/KB/WCF/WCF_Operation_Timeout_.aspx

To avoid this timeout error, we need to configure the OperationTimeout property for Proxy in the WCF client code. This configuration is something new unlike other configurations such as Send Timeout, Receive Timeout etc., which I discussed early in the article. To set this operation timeout property configuration, we have to cast our proxy to IContextChannel in WCF client application before calling the operation contract methods.

Cordova : Requirements check failed for JDK 1.8 or greater

The Ubuntu/Debian Linux version of this answer is to install openjdk 8 and set the default via update-alternatives


# install (open)jdk 8
sudo apt-get install -y openjdk-8-jdk

# update java compiler and set to 1.8
update-alternatives --config javac

# update java runtime (optional)
update-alternatives --config java

# Also set $JAVA_HOME and $PATH to your .bashrc (optional)
echo 'export JAVA_HOME=/usr/lib/jvm/java-8-openjdk-amd64' >> ~/.bashrc
echo 'export PATH="$PATH:$JAVA_HOME/bin' >> ~/.bashrc

# load in current bash session
source ~/.bashrc

What are "res" and "req" parameters in Express functions?

Request and response.

To understand the req, try out console.log(req);.

Get first row of dataframe in Python Pandas based on criteria

For the point that 'returns the value as soon as you find the first row/record that meets the requirements and NOT iterating other rows', the following code would work:

def pd_iter_func(df):
    for row in df.itertuples():
        # Define your criteria here
        if row.A > 4 and row.B > 3:
            return row

It is more efficient than Boolean Indexing when it comes to a large dataframe.

To make the function above more applicable, one can implements lambda functions:

def pd_iter_func(df: DataFrame, criteria: Callable[[NamedTuple], bool]) -> Optional[NamedTuple]:
    for row in df.itertuples():
        if criteria(row):
            return row

pd_iter_func(df, lambda row: row.A > 4 and row.B > 3)

As mentioned in the answer to the 'mirror' question, pandas.Series.idxmax would also be a nice choice.

def pd_idxmax_func(df, mask):
    return df.loc[mask.idxmax()]

pd_idxmax_func(df, (df.A > 4) & (df.B > 3))

Java: Convert a String (representing an IP) to InetAddress

From the documentation of InetAddress.getByName(String host):

The host name can either be a machine name, such as "java.sun.com", or a textual representation of its IP address. If a literal IP address is supplied, only the validity of the address format is checked.

So you can use it.

How to sort a list of strings?

l =['abc' , 'cd' , 'xy' , 'ba' , 'dc']
l.sort()
print(l1)

Result

['abc', 'ba', 'cd', 'dc', 'xy']

python: urllib2 how to send cookie with urlopen request

This answer is not working since the urllib2 module has been split across several modules in Python 3. You need to do

from urllib import request
opener = request.build_opener()
opener.addheaders.append(('Cookie', 'cookiename=cookievalue'))
f = opener.open("http://example.com/")

How to change date format in JavaScript

Use your mydate object and call getMonth() and getFullYear()

See this for more info: http://www.w3schools.com/jsref/jsref_obj_date.asp

Cocoa Touch: How To Change UIView's Border Color And Thickness?

item's border color in swift 4.2:

let cell = tableView.dequeueReusableCell(withIdentifier: "Cell_lastOrderId") as! Cell_lastOrder
cell.layer.borderWidth = 1
cell.layer.borderColor = UIColor.white.cgColor
cell.layer.cornerRadius = 10

Is there any JSON Web Token (JWT) example in C#?

I've never used it but there is a JWT implementation on NuGet.

Package: https://nuget.org/packages/JWT

Source: https://github.com/johnsheehan/jwt

.NET 4.0 compatible: https://www.nuget.org/packages/jose-jwt/

You can also go here: https://jwt.io/ and click "libraries".

Checking character length in ruby

You could take any of the answers above that use the string.length method and replace it with string.size.

They both work the same way.

if string.size <= 25
  puts "No problem here!"
else
  puts "Sorry too long!"
end

https://ruby-doc.org/core-2.4.0/String.html#method-i-size

How to test if JSON object is empty in Java

@Test
public void emptyJsonParseTest() {
    JsonNode emptyJsonNode = new ObjectMapper().createObjectNode();
    Assert.assertTrue(emptyJsonNode.asText().isEmpty());
}

javascript jquery radio button click

it is always good to restrict the DOM search. so better to use a parent also, so that the entire DOM won't be traversed.

IT IS VERY FAST

<div id="radioBtnDiv">
  <input name="myButton" type="radio" class="radioClass" value="manual" checked="checked"/>
 <input name="myButton" type="radio" class="radioClass" value="auto" checked="checked"/>
</div>



 $("input[name='myButton']",$('#radioBtnDiv')).change(
    function(e)
    {
        // your stuffs go here
    });

"OSError: [Errno 1] Operation not permitted" when installing Scrapy in OSX 10.11 (El Capitan) (System Integrity Protection)

Sometimes such behavior may be achieved if you try to install python3 lib in python2 folder using pip instead of pip3.

Read environment variables in Node.js

process.env.ENV_VARIABLE

Where ENV_VARIABLE is the name of the variable you wish to access.

See Node.js docs for process.env.

How to list branches that contain a given commit?

You may run:

git log <SHA1>..HEAD --ancestry-path --merges

From comment of last commit in the output you may find original branch name

Example:

       c---e---g--- feature
      /         \
-a---b---d---f---h---j--- master

git log e..master --ancestry-path --merges

commit h
Merge: g f
Author: Eugen Konkov <>
Date:   Sat Oct 1 00:54:18 2016 +0300

    Merge branch 'feature' into master

Use of the MANIFEST.MF file in Java

Manifest.MF contains information about the files contained in the JAR file.

Whenever a JAR file is created a default manifest.mf file is created inside META-INF folder and it contains the default entries like this:

Manifest-Version: 1.0
Created-By: 1.7.0_06 (Oracle Corporation)

These are entries as “header:value” pairs. The first one specifies the manifest version and second one specifies the JDK version with which the JAR file is created.

Main-Class header: When a JAR file is used to bundle an application in a package, we need to specify the class serving an entry point of the application. We provide this information using ‘Main-Class’ header of the manifest file,

Main-Class: {fully qualified classname}

The ‘Main-Class’ value here is the class having main method. After specifying this entry we can execute the JAR file to run the application.

Class-Path header: Most of the times we need to access the other JAR files from the classes packaged inside application’s JAR file. This can be done by providing their fully qualified paths in the manifest file using ‘Class-Path’ header,

Class-Path: {jar1-name jar2-name directory-name/jar3-name}

This header can be used to specify the external JAR files on the same local network and not inside the current JAR.

Package version related headers: When the JAR file is used for package versioning the following headers are used as specified by the Java language specification:

Headers in a manifest
Header                  | Definition
-------------------------------------------------------------------
Name                    | The name of the specification.
Specification-Title     | The title of the specification.
Specification-Version   | The version of the specification.
Specification-Vendor    | The vendor of the specification.
Implementation-Title    | The title of the implementation.
Implementation-Version  | The build number of the implementation.
Implementation-Vendor   | The vendor of the implementation.

Package sealing related headers:

We can also specify if any particular packages inside a JAR file should be sealed meaning all the classes defined in that package must be archived in the same JAR file. This can be specified with the help of ‘Sealed’ header,

Name: {package/some-package/} Sealed:true

Here, the package name must end with ‘/’.

Enhancing security with manifest files:

We can use manifest files entries to ensure the security of the web application or applet it packages with the different attributes as ‘Permissions’, ‘Codebae’, ‘Application-Name’, ‘Trusted-Only’ and many more.

META-INF folder:

This folder is where the manifest file resides. Also, it can contain more files containing meta data about the application. For example, in an EJB module JAR file, this folder contains the EJB deployment descriptor for the EJB module along with the manifest file for the JAR. Also, it contains the xml file containing mapping of an abstract EJB references to concrete container resources of the application server on which it will be run.

Reference:
https://docs.oracle.com/javase/tutorial/deployment/jar/manifestindex.html

How to choose an AES encryption mode (CBC ECB CTR OCB CFB)?

  1. Anything but ECB.
  2. If using CTR, it is imperative that you use a different IV for each message, otherwise you end up with the attacker being able to take two ciphertexts and deriving a combined unencrypted plaintext. The reason is that CTR mode essentially turns a block cipher into a stream cipher, and the first rule of stream ciphers is to never use the same Key+IV twice.
  3. There really isn't much difference in how difficult the modes are to implement. Some modes only require the block cipher to operate in the encrypting direction. However, most block ciphers, including AES, don't take much more code to implement decryption.
  4. For all cipher modes, it is important to use different IVs for each message if your messages could be identical in the first several bytes, and you don't want an attacker knowing this.

Disable browser's back button

Even I faced the same situation before...and didn't have any help. try these things maybe these will work for you

in login page <head> tag:

<script type="text/javascript">
    window.history.forward();
</script>

in Logout Button I did this:

protected void Btn_Logout_Click(object sender, EventArgs e)      
{
    connObj.Close();
    Session.Abandon();
    Session.RemoveAll();
    Session.Clear();
    HttpContext.Current.Session.Abandon();
}

and on login page I have put the focus on Username textbox like this:

protected void Page_Load(object sender, EventArgs e)
{
    _txtUsername.Focus();
}

hope this helps... :) someone plz teach me how to edit this page...

tsc throws `TS2307: Cannot find module` for a local file

In VS2019, the project property page, TypeScript Build tab has a setting (dropdown) for "Module System". When I changed that from "ES2015" to CommonJS, then VS2019 IDE stopped complaining that it could find neither axios nor redux-thunk (TS2307).

tsconfig.json:

{
  "compilerOptions": {
    "allowJs": true,
    "baseUrl": "src",
    "forceConsistentCasingInFileNames": true,
    "jsx": "react",
    "lib": [
      "es6",
      "dom",
      "es2015.promise"
    ],
    "module": "esnext",
    "moduleResolution": "node",
    "noImplicitAny": true,
    "noImplicitReturns": true,
    "noImplicitThis": true,
    "noUnusedLocals": true,
    "outDir": "build/dist",
    "rootDir": "src",
    "sourceMap": true,
    "strictNullChecks": true,
    "suppressImplicitAnyIndexErrors": true,
    "esModuleInterop": true,
    "allowSyntheticDefaultImports": true,
    "target": "es5",
    "skipLibCheck": true,
    "strict": true,
    "resolveJsonModule": true,
    "isolatedModules": true,
    "noEmit": true
  },
  "exclude": [
    "build",
    "scripts",
    "acceptance-tests",
    "webpack",
    "jest",
    "src/setupTests.ts",
    "node_modules",
    "obj",
    "**/*.spec.ts"
  ],
  "include": [
    "src",
    "src/**/*.ts",
    "@types/**/*.d.ts",
    "node_modules/axios",
    "node_modules/redux-thunk"
  ]
}

How to save local data in a Swift app?

NsUserDefaults saves only small variable sizes. If you want to save many objects you can use CoreData as a native solution, or I created a library that helps you save objects as easy as .save() function. It’s based on SQLite.

SundeedQLite

Check it out and tell me your comments

What are the rules for calling the superclass constructor?

Base class constructors are automatically called for you if they have no argument. If you want to call a superclass constructor with an argument, you must use the subclass's constructor initialization list. Unlike Java, C++ supports multiple inheritance (for better or worse), so the base class must be referred to by name, rather than "super()".

class SuperClass
{
    public:

        SuperClass(int foo)
        {
            // do something with foo
        }
};

class SubClass : public SuperClass
{
    public:

        SubClass(int foo, int bar)
        : SuperClass(foo)    // Call the superclass constructor in the subclass' initialization list.
        {
            // do something with bar
        }
};

More info on the constructor's initialization list here and here.

C++ inheritance - inaccessible base?

By default, inheritance is private. You have to explicitly use public:

class Bar : public Foo

"SSL certificate verify failed" using pip to install packages

Something to try --- tell python to not use https with the index directive and a http:// address (not https://)

pip install --index-url=http://pypi.python.org/simple/ --trusted-host pypi.python.org  Scrapy

You may be behind a corporate firewall and Ive have experiences where even the above failed, though Im not going to pretend like I know enough about firewalls or SSL to understand why. In that case the only way I was able to get around that was to get a certificate file and pass it to python. See kenorb’s answer here for details.

Can I use a :before or :after pseudo-element on an input field?

Oddly, it works with some types of input. At least in Chrome,

<input type="checkbox" />

works fine, same as

<input type="radio" />

It's just type=text and some others that don't work.

PHP How to find the time elapsed since a date time?

Improvisation to the function "humanTiming" by arnorhs. It would calculate a "fully stretched" translation of time string to human readable text version. For example to say it like "1 week 2 days 1 hour 28 minutes 14 seconds"

function humantime ($oldtime, $newtime = null, $returnarray = false)    {
    if(!$newtime) $newtime = time();
    $time = $newtime - $oldtime; // to get the time since that moment
    $tokens = array (
            31536000 => 'year',
            2592000 => 'month',
            604800 => 'week',
            86400 => 'day',
            3600 => 'hour',
            60 => 'minute',
            1 => 'second'
    );
    $htarray = array();
    foreach ($tokens as $unit => $text) {
            if ($time < $unit) continue;
            $numberOfUnits = floor($time / $unit);
            $htarray[$text] = $numberOfUnits.' '.$text.(($numberOfUnits>1)?'s':'');
            $time = $time - ( $unit * $numberOfUnits );
    }
    if($returnarray) return $htarray;
    return implode(' ', $htarray);
}

PHP Unset Array value effect on other indexes

The Key Disappears, whether it is numeric or not. Try out the test script below.

<?php
    $t = array( 'a', 'b', 'c', 'd' );
    foreach($t as $k => $v)
        echo($k . ": " . $v . "<br/>");
    // Output: 0: a, 1: b, 2: c, 3: d

    unset($t[1]);

    foreach($t as $k => $v)
        echo($k . ": " . $v . "<br/>");
    // Output: 0: a, 2: c, 3: d
?>

Lost httpd.conf file located apache

See http://wiki.apache.org/httpd/DistrosDefaultLayout for discussion of where you might find Apache httpd configuration files on various platforms, since this can vary from release to release and platform to platform. The most common answer, however, is either /etc/apache/conf or /etc/httpd/conf

Generically, you can determine the answer by running the command:

httpd -V

(That's a capital V). Or, on systems where httpd is renamed, perhaps apache2ctl -V

This will return various details about how httpd is built and configured, including the default location of the main configuration file.

One of the lines of output should look like:

-D SERVER_CONFIG_FILE="conf/httpd.conf"

which, combined with the line:

-D HTTPD_ROOT="/etc/httpd"

will give you a full path to the default location of the configuration file

How do you specify a different port number in SQL Management Studio?

Using the client manager affects all connections or sets a client machine specific alias.

Use the comma as above: this can be used in an app.config too

It's probably needed if you have firewalls between you and the server too...

java.lang.ClassNotFoundException: sun.jdbc.odbc.JdbcOdbcDriver Exception occurring. Why?

add these dependecies to your .pom file:

<dependency>
  <groupId>org.hsqldb</groupId>
  <artifactId>hsqldb</artifactId>
  <version>2.5.0</version>
  <scope>test</scope>
</dependency>

<dependency>
  <groupId>com.healthmarketscience.jackcess</groupId>
  <artifactId>jackcess-encrypt</artifactId>
  <version>3.0.0</version>
</dependency>

<dependency>
  <groupId>net.sf.ucanaccess</groupId>
  <artifactId>ucanaccess</artifactId>
  <version>5.0.0</version>
</dependency>

<dependency>
  <groupId>org.apache.commons</groupId>
  <artifactId>commons-lang3</artifactId>
  <version>3.9</version>
</dependency>

<dependency>
  <groupId>commons-logging</groupId>
  <artifactId>commons-logging</artifactId>
  <version>1.2</version>
</dependency>

and add to your code to call a driver:

Connection conn = DriverManager.getConnection("jdbc:ucanaccess://{file_location}/{accessdb_file_name.mdb};memory=false");

What do Push and Pop mean for Stacks?

Ok. As the other answerers explained, a stack is a last-in, first-out data structure. You add an element to the top of the stack with a Push operation. You take an element off the top with a Pop operation. The elements are removed in reverse order to the order they were put inserted (hence Last In, First Out). For example, if you push the elments 1,2,3 in that order, the number 3 will be at the top of the stack. A Pop operation will remove it (it was the last in) and leave 2 at the top of the stack.

Regarding the rest of the lecture, the lecturer tried to describe a stack-based machine that evaluates arithmetic expressions. The machine operates by continuously popping 3 elements from the top of the stack. The first two elements are operands and the third is an operator (+, -, *, /). It then applies this operator on the operands, and pushes the result onto the stack. The process continues until there is only one element on the stack, which is the value of the expression.

So, suppose we begin by pushing the values "+/*23-21*5-41" in left-to-right order onto the stack. We then pop 3 elements from the top. The last in is first out, which means the first 3 element are "1", "4", and "-" in that order. We push the number 3 (the result of 4-1) onto the stack, then pop the three topmost elements: 3, 5, *. Push the result, 15, onto the stack, and so on.

How to format DateTime in Flutter , How to get current time in flutter?

Try out this package, Jiffy, it also runs on top of Intl, but makes it easier using momentjs syntax. See below

import 'package:jiffy/jiffy.dart';   

var now = Jiffy().format("yyyy-MM-dd HH:mm:ss");

You can also do the following

var a = Jiffy().yMMMMd; // October 18, 2019

And you can also pass in your DateTime object, A string and an array

var a = Jiffy(DateTime(2019, 10, 18)).yMMMMd; // October 18, 2019

var a = Jiffy("2019-10-18").yMMMMd; // October 18, 2019

var a = Jiffy([2019, 10, 18]).yMMMMd; // October 18, 2019

SQL - ORDER BY 'datetime' DESC

Try:

SELECT post_datetime 
FROM post 
WHERE type = 'published' 
ORDER BY post_datetime DESC 
LIMIT 3

Font from origin has been blocked from loading by Cross-Origin Resource Sharing policy

Chrome since ~Sep/Oct 2014 makes fonts subject to the same CORS checks as Firefox has done https://code.google.com/p/chromium/issues/detail?id=286681. There is a discussion on this in https://groups.google.com/a/chromium.org/forum/?fromgroups=#!topic/blink-dev/TT9D5-Zfnzw

Given that for fonts the browser may do a preflight check, then your S3 policy needs the cors request header as well. You can check your page in say Safari (which at present doesn't do CORS checking for fonts) and Firefox (that does) to double check this is the problem described.

See Stack overflow answer on Amazon S3 CORS (Cross-Origin Resource Sharing) and Firefox cross-domain font loading for the Amazon S3 CORS details.

NB in general because this used to apply to Firefox only, so it may help to search for Firefox rather than Chrome.

JavaScript object: access variable property by name as string

You don't need a function for it - simply use the bracket notation:

var side = columns['right'];

This is equal to dot notation, var side = columns.right;, except the fact that right could also come from a variable, function return value, etc., when using bracket notation.

If you NEED a function for it, here it is:

function read_prop(obj, prop) {
    return obj[prop];
}

To answer some of the comments below that aren't directly related to the original question, nested objects can be referenced through multiple brackets. If you have a nested object like so:

var foo = { a: 1, b: 2, c: {x: 999, y:998, z: 997}};

you can access property x of c as follows:

var cx = foo['c']['x']

If a property is undefined, an attempt to reference it will return undefined (not null or false):

foo['c']['q'] === null
// returns false

foo['c']['q'] === false
// returns false

foo['c']['q'] === undefined
// returns true

How to read a .properties file which contains keys that have a period character using Shell script

Since variable names in the BASH shell cannot contain a dot or space it is better to use an associative array in BASH like this:

#!/bin/bash

# declare an associative array
declare -A arr

# read file line by line and populate the array. Field separator is "="
while IFS='=' read -r k v; do
   arr["$k"]="$v"
done < app.properties

Testing:

Use declare -p to show the result:

  > declare -p arr  

        declare -A arr='([db.uat.passwd]="secret" [db.uat.user]="saple user" )'

How to create a fix size list in python?

You can do it using array module. array module is part of python standard library:

from array import array
from itertools import repeat

a = array("i", repeat(0, 10))
# or
a = array("i", [0]*10)

repeat function repeats 0 value 10 times. It's more memory efficient than [0]*10, since it doesn't allocate memory, but repeats returning the same number x number of times.

Specifying an Index (Non-Unique Key) Using JPA

To sum up the other answers:

I would just go for one of them. It will come with JPA 2.1 anyway and should not be too hard to change in the case that you really want to switch your JPA provider.

How do I delete an item or object from an array using ng-click?

Using $index works perfectly well in basic cases, and @charlietfl's answer is great. But sometimes, $index isn't enough.

Imagine you have a single array, which you're presenting in two different ng-repeat's. One of those ng-repeat's is filtered for objects that have a truthy property, and the other is filtered for a falsy property. Two different filtered arrays are being presented, which derive from a single original array. (Or, if it helps to visualize: perhaps you have a single array of people, and you want one ng-repeat for the women in that array, and another for the men in that same array.) Your goal: delete reliably from the original array, using information from the members of the filtered arrays.

In each of those filtered arrays, $index won't be the index of the item within the original array. It'll be the index in the filtered sub-array. So, you won't be able to tell the person's index in the original people array, you'll only know the $index from the women or men sub-array. Try to delete using that, and you'll have items disappearing from everywhere except where you wanted. What to do?

If you're lucky enough be using a data model includes a unique identifier for each object, then use that instead of $index, to find the object and splice it out of the main array. (Use my example below, but with that unique identifier.) But if you're not so lucky?

Angular actually augments each item in an ng-repeated array (in the main, original array) with a unique property called $$hashKey. You can search the original array for a match on the $$hashKey of the item you want to delete, and get rid of it that way.

Note that $$hashKey is an implementation detail, not included in the published API for ng-repeat. They could remove support for that property at any time. But probably not. :-)

$scope.deleteFilteredItem = function(hashKey, sourceArray){
  angular.forEach(sourceArray, function(obj, index){
    // sourceArray is a reference to the original array passed to ng-repeat, 
    // rather than the filtered version. 
    // 1. compare the target object's hashKey to the current member of the iterable:
    if (obj.$$hashKey === hashKey) {
      // remove the matching item from the array
      sourceArray.splice(index, 1);
      // and exit the loop right away
      return;
    };
  });
}

Invoke with:

ng-click="deleteFilteredItem(item.$$hashKey, refToSourceArray)"

EDIT: Using a function like this, which keys on the $$hashKey instead of a model-specific property name, also has the significant added advantage of making this function reusable across different models and contexts. Provide it with your array reference, and your item reference, and it should just work.

Check if instance is of a type

The different answers here have two different meanings.

If you want to check whether an instance is of an exact type then

if (c.GetType() == typeof(TForm))

is the way to go.

If you want to know whether c is an instance of TForm or a subclass then use is/as:

if (c is TForm)

or

TForm form = c as TForm;
if (form != null)

It's worth being clear in your mind about which of these behaviour you actually want.

Get Value of a Edit Text field

Try this code

final EditText editText = findViewById(R.id.name); // your edittext id in xml
Button submit = findViewById(R.id.submit_button); // your button id in xml
submit.setOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View v) 
    {
        String string = editText.getText().toString();
        Toast.makeText(MainActivity.this, string, Toast.LENGTH_SHORT).show();
    }
});

How do I cancel form submission in submit button onclick event?

You need to change

onclick='btnClick();'

to

onclick='return btnClick();'

and

cancelFormSubmission();

to

return false;

That said, I'd try to avoid the intrinsic event attributes in favour of unobtrusive JS with a library (such as YUI or jQuery) that has a good event handling API and tie into the event that really matters (i.e. the form's submit event instead of the button's click event).

Laravel orderBy on a relationship

It is possible to extend the relation with query functions:

<?php
public function comments()
{
    return $this->hasMany('Comment')->orderBy('column');
}

[edit after comment]

<?php
class User
{
    public function comments()
    {
        return $this->hasMany('Comment');
    }
}

class Controller
{
    public function index()
    {
        $column = Input::get('orderBy', 'defaultColumn');
        $comments = User::find(1)->comments()->orderBy($column)->get();

        // use $comments in the template
    }
}

default User model + simple Controller example; when getting the list of comments, just apply the orderBy() based on Input::get(). (be sure to do some input-checking ;) )

Jquery asp.net Button Click Event via ajax

This is where jQuery really shines for ASP.Net developers. Lets say you have this ASP button:

When that renders, you can look at the source of the page and the id on it won't be btnAwesome, but $ctr001_btnAwesome or something like that. This makes it a pain in the butt to find in javascript. Enter jQuery.

$(document).ready(function() {
  $("input[id$='btnAwesome']").click(function() {
    // Do client side button click stuff here.
  });
});

The id$= is doing a regex match for an id ENDING with btnAwesome.

Edit:

Did you want the ajax call being called from the button click event on the client side? What did you want to call? There are a lot of really good articles on using jQuery to make ajax calls to ASP.Net code behind methods.

The gist of it is you create a static method marked with the WebMethod attribute. You then can make a call to it using jQuery by using $.ajax.

$.ajax({
  type: "POST",
  url: "PageName.aspx/MethodName",
  data: "{}",
  contentType: "application/json; charset=utf-8",
  dataType: "json",
  success: function(msg) {
    // Do something interesting here.
  }
});

I learned my WebMethod stuff from: http://encosia.com/2008/05/29/using-jquery-to-directly-call-aspnet-ajax-page-methods/

A lot of really good ASP.Net/jQuery stuff there. Make sure you read up about why you have to use msg.d in the return on .Net 3.5 (maybe since 3.0) stuff.

Find all elements on a page whose element ID contains a certain text using jQuery

If you're finding by Contains then it'll be like this

    $("input[id*='DiscountType']").each(function (i, el) {
         //It'll be an array of elements
     });

If you're finding by Starts With then it'll be like this

    $("input[id^='DiscountType']").each(function (i, el) {
         //It'll be an array of elements
     });

If you're finding by Ends With then it'll be like this

     $("input[id$='DiscountType']").each(function (i, el) {
         //It'll be an array of elements
     });

If you want to select elements which id is not a given string

    $("input[id!='DiscountType']").each(function (i, el) {
         //It'll be an array of elements
     });

If you want to select elements which name contains a given word, delimited by spaces

     $("input[name~='DiscountType']").each(function (i, el) {
         //It'll be an array of elements
     });

If you want to select elements which id is equal to a given string or starting with that string followed by a hyphen

     $("input[id|='DiscountType']").each(function (i, el) {
         //It'll be an array of elements
     });

python pip: force install ignoring dependencies

pip has a --no-dependencies switch. You should use that.

For more information, run pip install -h, where you'll see this line:

--no-deps, --no-dependencies
                        Ignore package dependencies

How do I set the maximum line length in PyCharm?

You can even set a separate right margin for HTML. Under the specified path:

File >> Settings >> Editor >> Code Style >> HTML >> Other Tab >> Right margin (columns)

This is very useful because generally HTML and JS may be usually long in one line than Python. :)

How do I select the parent form based on which submit button is clicked?

You can select the form like this:

$("#submit").click(function(){
    var form = $(this).parents('form:first');
    ...
});

However, it is generally better to attach the event to the submit event of the form itself, as it will trigger even when submitting by pressing the enter key from one of the fields:

$('form#myform1').submit(function(e){
     e.preventDefault(); //Prevent the normal submission action
     var form = this;
     // ... Handle form submission
});

To select fields inside the form, use the form context. For example:

$("input[name='somename']",form).val();

Better/Faster to Loop through set or list?

set is what you want, so you should use set. Trying to be clever introduces subtle bugs like forgetting to add one tomax(mylist)! Code defensively. Worry about what's faster when you determine that it is too slow.

range(min(mylist), max(mylist) + 1)  # <-- don't forget to add 1

Unused arguments in R

You could use dots: ... in your function definition.

myfun <- function(a, b, ...){
  cat(a,b)
}

myfun(a=4,b=7,hello=3)

# 4 7

Laravel Unknown Column 'updated_at'

Nice answer by Alex and Sameer, but maybe just additional info on why is necessary to put

public $timestamps = false;

Timestamps are nicely explained on official Laravel page:

By default, Eloquent expects created_at and updated_at columns to exist on your >tables. If you do not wish to have these columns automatically managed by >Eloquent, set the $timestamps property on your model to false.

`require': no such file to load -- mkmf (LoadError)

I got the similar error when install bundle

sudo apt-get install ruby-dev

Works great for me and solve the problem Mint 16 ruby1.9.3

Creating custom function in React component

You can create functions in react components. It is actually regular ES6 class which inherits from React.Component. Just be careful and bind it to the correct context in onClick event:

export default class Archive extends React.Component { 

    saySomething(something) {
        console.log(something);
    }

    handleClick(e) {
        this.saySomething("element clicked");
    }

    componentDidMount() {
        this.saySomething("component did mount");
    }

    render() {
        return <button onClick={this.handleClick.bind(this)} value="Click me" />;
    }
}

Scale iFrame css width 100% like an image

Big difference between an image and an iframe is the fact that an image keeps its aspect-ratio. You could combine an image and an iframe with will result in a responsive iframe. Hope this answerers your question.

Check this link for example : http://jsfiddle.net/Masau/7WRHM/

HTML:

<div class="wrapper">
    <div class="h_iframe">
        <!-- a transparent image is preferable -->
        <img class="ratio" src="http://placehold.it/16x9"/>
        <iframe src="http://www.youtube.com/embed/WsFWhL4Y84Y" frameborder="0" allowfullscreen></iframe>
    </div>
    <p>Please scale the "result" window to notice the effect.</p>
</div>

CSS:

html,body        {height:100%;}
.wrapper         {width:80%;height:100%;margin:0 auto;background:#CCC}
.h_iframe        {position:relative;}
.h_iframe .ratio {display:block;width:100%;height:auto;}
.h_iframe iframe {position:absolute;top:0;left:0;width:100%; height:100%;}

note: This only works with a fixed aspect-ratio.

ActiveRecord find and only return selected columns

My answer comes quite late because I'm a pretty new developer. This is what you can do:

Location.select(:name, :website, :city).find(row.id)

Btw, this is Rails 4

In Git, what is the difference between origin/master vs origin master?

origin/master is an entity (since it is not a physical branch) representing the state of the master branch on the remote origin.

origin master is the branch master on the remote origin.

So we have these:

  • origin/master ( A representation or a pointer to the remote branch)
  • master - (actual branch)
  • <Your_local_branch> (actual branch)
  • <Your_local_branch4> (actual branch)
  • <Your_local_branch4> (actual branch)

Example (in local branch master):

git fetch # get current state of remote repository
git merge origin/master # merge state of remote master branch into local branch
git push origin master # push local branch master to remote branch master

Comparing two dataframes and getting the differences

Updating and placing, somewhere it will be easier for others to find, ling's comment upon jur's response above.

df_diff = pd.concat([df1,df2]).drop_duplicates(keep=False)

Testing with these DataFrames:

# with import pandas as pd

df1 = pd.DataFrame({
    'Date':['2013-11-24','2013-11-24','2013-11-24','2013-11-24'],
    'Fruit':['Banana','Orange','Apple','Celery'],
    'Num':[22.1,8.6,7.6,10.2],
    'Color':['Yellow','Orange','Green','Green'],
    })

df2 = pd.DataFrame({
    'Date':['2013-11-24','2013-11-24','2013-11-24','2013-11-24','2013-11-25','2013-11-25'],
    'Fruit':['Banana','Orange','Apple','Celery','Apple','Orange'],
    'Num':[22.1,8.6,7.6,10.2,22.1,8.6],
    'Color':['Yellow','Orange','Green','Green','Red','Orange'],
    })

Results in this:

# for df1

         Date   Fruit   Num   Color
0  2013-11-24  Banana  22.1  Yellow
1  2013-11-24  Orange   8.6  Orange
2  2013-11-24   Apple   7.6   Green
3  2013-11-24  Celery  10.2   Green


# for df2

         Date   Fruit   Num   Color
0  2013-11-24  Banana  22.1  Yellow
1  2013-11-24  Orange   8.6  Orange
2  2013-11-24   Apple   7.6   Green
3  2013-11-24  Celery  10.2   Green
4  2013-11-25   Apple  22.1     Red
5  2013-11-25  Orange   8.6  Orange


# for df_diff

         Date   Fruit   Num   Color
4  2013-11-25   Apple  22.1     Red
5  2013-11-25  Orange   8.6  Orange

Nullable property to entity field, Entity Framework through Code First

Jon's answer didn't work for me as I got a compiler error CS0453 C# The type must be a non-nullable value type in order to use it as parameter 'T' in the generic type or method

This worked for me though:

protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
    modelBuilder.Entity<SomeObject>().HasOptional(m => m.somefield);
    base.OnModelCreating(modelBuilder);
}

Deleting row from datatable in C#

There several different ways to do it. But You can use the following approach:

List<DataRow> RowsToDelete = new List<DataRow>();

for (int i = 0; i < drr.Length; i++) 
{     
   if(condition to delete the row) 
   {  
       RowsToDelete.Add(drr[i]);     
   } 
}

foreach(var dr in RowsToDelete) 
{     
   drr.Rows.Remove(dr); 
} 

Integer.valueOf() vs. Integer.parseInt()

The difference between these two methods is:

  • parseXxx() returns the primitive type
  • valueOf() returns a wrapper object reference of the type.

Escaping a forward slash in a regular expression

Here are a few options:

  • In Perl, you can choose alternate delimiters. You're not confined to m//. You could choose another, such as m{}. Then escaping isn't necessary. As a matter of fact, Damian Conway in "Perl Best Practices" asserts that m{} is the only alternate delimiter that ought to be used, and this is reinforced by Perl::Critic (on CPAN). While you can get away with using a variety of alternate delimiter characters, // and {} seem to be the clearest to decipher later on. However, if either of those choices result in too much escaping, choose whichever one lends itself best to legibility. Common examples are m(...), m[...], and m!...!.

  • In cases where you either cannot or prefer not to use alternate delimiters, you can escape the forward slashes with a backslash: m/\/[^/]+$/ for example (using an alternate delimiter that could become m{/[^/]+$}, which may read more clearly). Escaping the slash with a backslash is common enough to have earned a name and a wikipedia page: Leaning Toothpick Syndrome. In regular expressions where there's just a single instance, escaping a slash might not rise to the level of being considered a hindrance to legibility, but if it starts to get out of hand, and if your language permits alternate delimiters as Perl does, that would be the preferred solution.

What should be the package name of android app?

package name with 0 may cause problem for sharedPreference.

(OK) con = createPackageContext("com.example.android.sf1", 0);

(Problem but no error)

con = createPackageContext("com.example.android.sf01", 0);

Are there any worse sorting algorithms than Bogosort (a.k.a Monkey Sort)?

There is a sort that's called bogobogosort. First, it checks the first 2 elements, and bogosorts them. Next it checks the first 3, bogosorts them, and so on.

Should the list be out of order at any time, it restarts by bogosorting the first 2 again. Regular bogosort has a average complexity of O(N!), this algorithm has a average complexity of O(N!1!2!3!...N!)

Edit: To give you an idea of how large this number is, for 20 elements, this algorithm takes an average of 3.930093*10^158 years,well above the proposed heat death of the universe(if it happens) of 10^100 years,

whereas merge sort takes around .0000004 seconds, bubble sort .0000016 seconds, and bogosort takes 308 years, 139 days, 19 hours, 35 minutes, 22.306 seconds, assuming a year is 365.242 days and a computer does 250,000,000 32 bit integer operations per second.

Edit2: This algorithm is not as slow as the "algorithm" miracle sort, which probably, like this sort, will get the computer sucked in the black hole before it successfully sorts 20 elemtnts, but if it did, I would estimate an average complexity of 2^(32(the number of bits in a 32 bit integer)*N)(the number of elements)*(a number <=10^40) years,

since gravity speeds up the chips alpha moving, and there are 2^N states, which is 2^640*10^40, or about 5.783*10^216.762162762 years, though if the list started out sorted, its complexity would only be O(N), faster than merge sort, which is only N log N even at the worst case.

Edit3: This algorithm is actually slower than miracle sort as the size gets very big, say 1000, since my algorithm would have a run time of 2.83*10^1175546 years, while the miracle sort algorithm would have a run time of 1.156*10^9657 years.

How can I add to a List's first position?

Use List.Insert(0, ...). But are you sure a LinkedList isn't a better fit? Each time you insert an item into an array at a position other than the array end, all existing items will have to be copied to make space for the new one.

int value under 10 convert to string two digit number

You can also do it this way

private static string GetPaddingSequence(int padding)
{
      StringBuilder SB = new StringBuilder();
      for (int i = 0; i < padding; i++)
      {
           SB.Append("0");
      }

      return SB.ToString();
  }

public static string FormatNumber(int number, int padding)
{
    return number.ToString(GetPaddingSequence(padding));
}

Finally call the function FormatNumber

string x = FormatNumber(1,2);

Output will be 01 which is based on your padding parameter. Increasing it will increase the number of 0s

Evaluate expression given as a string

Not sure why no one has mentioned two Base R functions specifically to do this: str2lang() and str2expression(). These are variants of parse(), but seem to return the expression more cleanly:

eval(str2lang("5+5"))

# > 10
  
eval(str2expression("5+5"))

# > 10

Also want to push back against the posters saying that anyone trying to do this is wrong. I'm reading in R expressions stored as text in a file and trying to evaluate them. These functions are perfect for this use case.

Creating hard and soft links using PowerShell

New-Symlink:

Function New-SymLink ($link, $target)
{
    if (test-path -pathtype container $target)
    {
        $command = "cmd /c mklink /d"
    }
    else
    {
        $command = "cmd /c mklink"
    }

    invoke-expression "$command $link $target"
}

Remove-Symlink:

Function Remove-SymLink ($link)
{
    if (test-path -pathtype container $link)
    {
        $command = "cmd /c rmdir"
    }
    else
    {
        $command = "cmd /c del"
    }

    invoke-expression "$command $link"
}

Usage:

New-Symlink "c:\foo\bar" "c:\foo\baz"
Remove-Symlink "c:\foo\bar"

Check if an element is a child of a parent

Ended up using .closest() instead.

$(document).on("click", function (event) {
    if($(event.target).closest(".CustomControllerMainDiv").length == 1)
    alert('element is a child of the custom controller')
});

how to access downloads folder in android?

If you're using a shell, the filepath to the Download (no "s") folder is

/storage/emulated/0/Download

Fastest way to list all primes below N

Here's the code I normally use to generate primes in Python:

$ python -mtimeit -s'import sieve' 'sieve.sieve(1000000)' 
10 loops, best of 3: 445 msec per loop
$ cat sieve.py
from math import sqrt

def sieve(size):
 prime=[True]*size
 rng=xrange
 limit=int(sqrt(size))

 for i in rng(3,limit+1,+2):
  if prime[i]:
   prime[i*i::+i]=[False]*len(prime[i*i::+i])

 return [2]+[i for i in rng(3,size,+2) if prime[i]]

if __name__=='__main__':
 print sieve(100)

It can't compete with the faster solutions posted here, but at least it is pure python.

Thanks for posting this question. I really learnt a lot today.

How to find the largest file in a directory and its subdirectories?

This lists files recursively if they're normal files, sorts by the 7th field (which is size in my find output; check yours), and shows just the first file.

find . -type f -ls | sort +7 | head -1

The first option to find is the start path for the recursive search. A -type of f searches for normal files. Note that if you try to parse this as a filename, you may fail if the filename contains spaces, newlines or other special characters. The options to sort also vary by operating system. I'm using FreeBSD.

A "better" but more complex and heavier solution would be to have find traverse the directories, but perhaps use stat to get the details about the file, then perhaps use awk to find the largest size. Note that the output of stat also depends on your operating system.

Set a default font for whole iOS app?

As @Randall in his answer mentioned iOS 5.0+ UIAppearance proxy can be used to customize the appearance of all instances of a class read more.

UILabel.appearance().font = .systemFont(ofSize: 17, weight: .regular)

How to set radio button selected value using jquery

document.getElementById("TestToggleRadioButtonList").rows[0].cells[0].childNodes[0].checked = true;

where TestToggleRadioButtonList is the id of the RadioButtonList.

git: fatal: Could not read from remote repository

I solved this problem by switching to root with sudo su.

Want custom title / image / description in facebook share link from a flash app

I had this same problem a week ago.

First of all I noticed your URL has an ampersand preceding the parameter string, but it probably needs to have a question mark instead to begin the parameter string, followed by an ampersand between each additional parameter.

Now, you do need to escape your URL but also double-escape the URL parameters (title or other content you need to provide content in the Share) you are passing to the URL, as follows:

var myParams = 't=' + escape('Some title here.') + '&id=' + escape('some content ID or any other value I want to load');
var fooBar = 'http://www.facebook.com/share.php?u=' + escape('http://foobar.com/superDuperSharingPage.php?' + myParams);

Now, you need to create the above-linked superDuperSharingPage.php, which should provide the dynamic title, description, and image content you desire. Something like this should suffice:

<?php
    // get our URL query parameters
    $title = $_GET['t'];
    $id = $_GET['id'];
    // maybe we want to load some content with the id I'll pretend we loaded a
    // description from some database in the sky which is magically arranged thusly:
    $desciption = $databaseInTheSky[$id]['description'];
?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
  <title><?php echo $title;?></title>
  <meta http-equiv="content-type" content="text/html; charset=utf-8" />
  <meta name="title" content="<?php echo $title;?>" />
  <meta name="description" content="<?php echo $desciption;?>" />
  <!-- the following line redirects to wherever we want the USER to land -->
  <!-- Facebook won't follow it. you may or may not actually want || need this. -->
  <meta http-equiv="refresh" content="1;URL=http://foobar.com" />
</head>
<body>
  <p><?php echo $desciption;?></p>
  <p><img src="image_a_<?php echo $id;?>.jpg" alt="Alt tags are always a good idea." /></p>
  <p><img src="image_b_<?php echo $id;?>.jpg" alt="Make the web more accessible to the blind!" /></p>
</body>
</html>

Let me know if this works for you, it's essentially what did for me :)

Appending an element to the end of a list in Scala

Lists in Scala are not designed to be modified. In fact, you can't add elements to a Scala List; it's an immutable data structure, like a Java String. What you actually do when you "add an element to a list" in Scala is to create a new List from an existing List. (Source)

Instead of using lists for such use cases, I suggest to either use an ArrayBuffer or a ListBuffer. Those datastructures are designed to have new elements added.

Finally, after all your operations are done, the buffer then can be converted into a list. See the following REPL example:

scala> import scala.collection.mutable.ListBuffer
import scala.collection.mutable.ListBuffer

scala> var fruits = new ListBuffer[String]()
fruits: scala.collection.mutable.ListBuffer[String] = ListBuffer()

scala> fruits += "Apple"
res0: scala.collection.mutable.ListBuffer[String] = ListBuffer(Apple)

scala> fruits += "Banana"
res1: scala.collection.mutable.ListBuffer[String] = ListBuffer(Apple, Banana)

scala> fruits += "Orange"
res2: scala.collection.mutable.ListBuffer[String] = ListBuffer(Apple, Banana, Orange)

scala> val fruitsList = fruits.toList
fruitsList: List[String] = List(Apple, Banana, Orange)

How to use MySQL DECIMAL?

Although the answers above seems correct, just a simple explanation to give you an idea of how it works.

Suppose that your column is set to be DECIMAL(13,4). This means that the column will have a total size of 13 digits where 4 of these will be used for precision representation.

So, in summary, for that column you would have a max value of: 999999999.9999

AngularJS sorting by property

Armin's answer + a strict check for object types and non-angular keys such as $resolve

app.filter('orderObjectBy', function(){
 return function(input, attribute) {
    if (!angular.isObject(input)) return input;

    var array = [];
    for(var objectKey in input) {
      if (typeof(input[objectKey])  === "object" && objectKey.charAt(0) !== "$")
        array.push(input[objectKey]);
    }

    array.sort(function(a, b){
        a = parseInt(a[attribute]);
        b = parseInt(b[attribute]);
        return a - b;
    });

    return array;
 }
})

WHERE Clause to find all records in a specific month

Using the MONTH and YEAR functions as suggested in most of the responses has the disadvantage that SQL Server will not be able to use any index there may be on your date column. This can kill performance on a large table.

I would be inclined to pass a DATETIME value (e.g. @StartDate) to the stored procedure which represents the first day of the month you are interested in.

You can then use

SELECT ... FROM ...
WHERE DateColumn >= @StartDate 
AND DateColumn < DATEADD(month, 1, @StartDate)

If you must pass the month and year as separate parameters to the stored procedure, you can generate a DATETIME representing the first day of the month using CAST and CONVERT then proceed as above. If you do this I would recommend writing a function that generates a DATETIME from integer year, month, day values, e.g. the following from a SQL Server blog.

create function Date(@Year int, @Month int, @Day int)
returns datetime
as
    begin
    return dateadd(month,((@Year-1900)*12)+@Month-1,@Day-1)
    end
go

The query then becomes:

SELECT ... FROM ...
WHERE DateColumn >= Date(@Year,@Month,1)
AND DateColumn < DATEADD(month, 1, Date(@Year,@Month,1))

Ways to circumvent the same-origin policy

The Reverse Proxy method

  • Method type: Ajax

Setting up a simple reverse proxy on the server, will allow the browser to use relative paths for the Ajax requests, while the server would be acting as a proxy to any remote location.

If using mod_proxy in Apache, the fundamental configuration directive to set up a reverse proxy is the ProxyPass. It is typically used as follows:

ProxyPass     /ajax/     http://other-domain.com/ajax/

In this case, the browser would be able to request /ajax/web_service.xml as a relative URL, but the server would serve this by acting as a proxy to http://other-domain.com/ajax/web_service.xml.

One interesting feature of the this method is that the reverse proxy can easily distribute requests towards multiple back-ends, thus acting as a load balancer.

How do I clear the previous text field value after submitting the form with out refreshing the entire page?

try this:

Using jQuery:

You can reset the entire form with:

$("#myform")[0].reset();

Or just the specific field with:

$('#form-id').children('input').val('')

Using JavaScript Without jQuery

<input type="button" value="Submit" id="btnsubmit" onclick="submitForm()">

function submitForm() {
   // Get the first form with the name
   // Hopefully there is only one, but there are more, select the correct index
   var frm = document.getElementsByName('contact-form')[0];
   frm.submit(); // Submit
   frm.reset();  // Reset
   return false; // Prevent page refresh
}

How do I write data to csv file in columns and rows from a list in python?

>>> import csv
>>> with open('test.csv', 'wb') as f:
...     wtr = csv.writer(f, delimiter= ' ')
...     wtr.writerows( [[1, 2], [2, 3], [4, 5]])
...
>>> with open('test.csv', 'r') as f:
...     for line in f:
...         print line,
...
1 2 <<=== Exactly what you said that you wanted.
2 3
4 5
>>>

To get it so that it can be loaded sensibly by Excel, you need to use a comma (the csv default) as the delimiter, unless you are in a locale (e.g. Europe) where you need a semicolon.

Adding an HTTP Header to the request in a servlet filter

Extend HttpServletRequestWrapper, override the header getters to return the parameters as well:

public class AddParamsToHeader extends HttpServletRequestWrapper {
    public AddParamsToHeader(HttpServletRequest request) {
        super(request);
    }

    public String getHeader(String name) {
        String header = super.getHeader(name);
        return (header != null) ? header : super.getParameter(name); // Note: you can't use getParameterValues() here.
    }

    public Enumeration getHeaderNames() {
        List<String> names = Collections.list(super.getHeaderNames());
        names.addAll(Collections.list(super.getParameterNames()));
        return Collections.enumeration(names);
    }
}

..and wrap the original request with it:

chain.doFilter(new AddParamsToHeader((HttpServletRequest) request), response);

That said, I personally find this a bad idea. Rather give it direct access to the parameters or pass the parameters to it.

Cast to generic type in C#

You can write a method that takes the type as a generic parameter:

void GenericProcessMessage<T>(T message)
{
    MessageProcessor<T> processor = messageProcessors[typeof(T)]
        as MessageProcessor<T>;

    //  Call method processor or whatever you need to do
}

Then you need a way to call the method with the correct generic argument. You can do this with reflection:

public void ProcessMessage(object message)
{
    Type messageType = message.GetType();
    MethodInfo method = this.GetType().GetMethod("GenericProcessMessage");
    MethodInfo closedMethod = method.MakeGenericMethod(messageType);
    closedMethod.Invoke(this, new object[] {message});
}

Can you style an html radio button to look like a checkbox?

Simple and neat with fontawesome

input[type=radio] {
    -moz-appearance: none;
    -webkit-appearance: none;
    -o-appearance: none;
    outline: none;
    content: none;
    margin-left: 5px;
}

input[type=radio]:before {
    font-family: "FontAwesome";
    content: "\f00c";
    font-size: 25px;
    color: transparent !important;
    background: #fff;
    width: 25px;
    height: 25px;
    border: 2px solid black;
    margin-right: 5px;
}

input[type=radio]:checked:before {
    color: black !important;
}

How can I detect browser type using jQuery?

The best solution is probably: use Modernizr.

However, if you necessarily want to use $.browser property, you can do it using jQuery Migrate plugin (for JQuery >= 1.9 - in earlier versions you can just use it) and then do something like:

if($.browser.chrome) {
   alert(1);
} else if ($.browser.mozilla) {
   alert(2);
} else if ($.browser.msie) {
   alert(3);
}

And if you need for some reason to use navigator.userAgent, then it would be:

$.browser.msie = /msie/.test(navigator.userAgent.toLowerCase()); 
$.browser.mozilla = /firefox/.test(navigator.userAgent.toLowerCase()); 

Function to Calculate Median in SQL Server

If you want to use the Create Aggregate function in SQL Server, this is how to do it. Doing it this way has the benefit of being able to write clean queries. Note this this process could be adapted to calculate a Percentile value fairly easily.

Create a new Visual Studio project and set the target framework to .NET 3.5 (this is for SQL 2008, it may be different in SQL 2012). Then create a class file and put in the following code, or c# equivalent:

Imports Microsoft.SqlServer.Server
Imports System.Data.SqlTypes
Imports System.IO

<Serializable>
<SqlUserDefinedAggregate(Format.UserDefined, IsInvariantToNulls:=True, IsInvariantToDuplicates:=False, _
  IsInvariantToOrder:=True, MaxByteSize:=-1, IsNullIfEmpty:=True)>
Public Class Median
  Implements IBinarySerialize
  Private _items As List(Of Decimal)

  Public Sub Init()
    _items = New List(Of Decimal)()
  End Sub

  Public Sub Accumulate(value As SqlDecimal)
    If Not value.IsNull Then
      _items.Add(value.Value)
    End If
  End Sub

  Public Sub Merge(other As Median)
    If other._items IsNot Nothing Then
      _items.AddRange(other._items)
    End If
  End Sub

  Public Function Terminate() As SqlDecimal
    If _items.Count <> 0 Then
      Dim result As Decimal
      _items = _items.OrderBy(Function(i) i).ToList()
      If _items.Count Mod 2 = 0 Then
        result = ((_items((_items.Count / 2) - 1)) + (_items(_items.Count / 2))) / 2@
      Else
        result = _items((_items.Count - 1) / 2)
      End If

      Return New SqlDecimal(result)
    Else
      Return New SqlDecimal()
    End If
  End Function

  Public Sub Read(r As BinaryReader) Implements IBinarySerialize.Read
    'deserialize it from a string
    Dim list = r.ReadString()
    _items = New List(Of Decimal)

    For Each value In list.Split(","c)
      Dim number As Decimal
      If Decimal.TryParse(value, number) Then
        _items.Add(number)
      End If
    Next

  End Sub

  Public Sub Write(w As BinaryWriter) Implements IBinarySerialize.Write
    'serialize the list to a string
    Dim list = ""

    For Each item In _items
      If list <> "" Then
        list += ","
      End If      
      list += item.ToString()
    Next
    w.Write(list)
  End Sub
End Class

Then compile it and copy the DLL and PDB file to your SQL Server machine and run the following command in SQL Server:

CREATE ASSEMBLY CustomAggregate FROM '{path to your DLL}'
WITH PERMISSION_SET=SAFE;
GO

CREATE AGGREGATE Median(@value decimal(9, 3))
RETURNS decimal(9, 3) 
EXTERNAL NAME [CustomAggregate].[{namespace of your DLL}.Median];
GO

You can then write a query to calculate the median like this: SELECT dbo.Median(Field) FROM Table

How can I get date and time formats based on Culture Info?

Culture can be changed for a specific cell in grid view.

<%# DateTime.ParseExact(Eval("contractdate", "{0}"), "MM/dd/yyyy", System.Globalization.CultureInfo.InvariantCulture).ToString("dd/MM/yyyy", System.Globalization.CultureInfo.CurrentCulture) %>

For more detail check the link.

Date Format Issue in Gridview binding with #eval()

UnmodifiableMap (Java Collections) vs ImmutableMap (Google)

Guava Documentation

The JDK provides Collections.unmodifiableXXX methods, but in our opinion, these can be unwieldy and verbose; unpleasant to use everywhere you want to make defensive copies unsafe: the returned collections are only truly immutable if nobody holds a reference to the original collection inefficient: the data structures still have all the overhead of mutable collections, including concurrent modification checks, extra space in hash tables, etc.

Php header location redirect not working

Use @obstart or try to use Java Script

put your obstart(); into your top of the page

if ((isset($_POST['cancel'])) && ($_POST['cancel'] == 'cancel'))
{
    header('Location: page1.php');
    exit();
}

If you use Javascript Use window.location.href

window.location.href example:

 if ((isset($_POST['cancel'])) && ($_POST['cancel'] == 'cancel'))
    {
        echo "<script type='text/javascript'>window.location.href = 'page1.php';</script>"
        exit();
    }

Cannot install NodeJs: /usr/bin/env: node: No such file or directory

I've found this is often a misnaming error, if you install from a package manager you bin may be called nodejs so you just need to symlink it like so

ln -s /usr/bin/nodejs /usr/bin/node

How do I set up cron to run a file just once at a specific time?

You could put a crontab file in /etc/cron.d which would run a script that would run your command and then delete the crontab file in /etc/cron.d. Of course, that means your script would need to run as root.

Calling a Javascript Function from Console

If it's inside a closure, i'm pretty sure you can't.

Otherwise you just do functionName(); and hit return.

Installing tensorflow with anaconda in windows

The above steps

conda install -c conda-forge tensorflow

will work for Windows 10 as well but the Python version should be 3.5 or above. I have used it with Anaconda Python version 3.6 as the protocol buffer format it refers to available on 3.5 or above. Thanks, Sandip

Change the color of a checked menu item in a navigation drawer

Well you can achieve this using Color State Resource. If you notice inside your NavigationView you're using

app:itemIconTint="@color/black"
app:itemTextColor="@color/primary_text"

Here instead of using @color/black or @color/primary_test, use a Color State List Resource. For that, first create a new xml (e.g drawer_item.xml) inside color directory (which should be inside res directory.) If you don't have a directory named color already, create one.

Now inside drawer_item.xml do something like this

<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
    <item android:color="checked state color" android:state_checked="true" />
    <item android:color="your default color" />
</selector>

Final step would be to change your NavigationView

<android.support.design.widget.NavigationView
    android:id="@+id/activity_main_navigationview"
    android:layout_width="wrap_content"
    android:layout_height="match_parent"
    android:layout_gravity="start"
    app:headerLayout="@layout/drawer_header"
    app:itemIconTint="@color/drawer_item"  // notice here
    app:itemTextColor="@color/drawer_item" // and here
    app:itemBackground="@android:color/transparent"// and here for setting the background color to tranparent
    app:menu="@menu/menu_drawer">

Like this you can use separate Color State List Resources for IconTint, ItemTextColor, ItemBackground.

Now when you set an item as checked (either in xml or programmatically), the particular item will have different color than the unchecked ones.

What is the difference between atomic / volatile / synchronized?

Synchronized Vs Atomic Vs Volatile:

  • Volatile and Atomic is apply only on variable , While Synchronized apply on method.
  • Volatile ensure about visibility not atomicity/consistency of object , While other both ensure about visibility and atomicity.
  • Volatile variable store in RAM and it’s faster in access but we can’t achive Thread safety or synchronization whitout synchronized keyword.
  • Synchronized implemented as synchronized block or synchronized method while both not. We can thread safe multiple line of code with help of synchronized keyword while with both we can’t achieve the same.
  • Synchronized can lock the same class object or different class object while both can’t.

Please correct me if anything i missed.

Develop Android app using C#

Here is a new one (Note: in Tech Preview stage): http://www.dot42.com

It is basically a Visual Studio add-in that lets you compile your C# code directly to DEX code. This means there is no run-time requirement such as Mono.

Disclosure: I work for this company


UPDATE: all sources are now on https://github.com/dot42

Receiving JSON data back from HTTP request

What I normally do, similar to answer one:

var response = await httpClient.GetAsync(completeURL); // http://192.168.0.1:915/api/Controller/Object

if (response.IsSuccessStatusCode == true)
    {
        string res = await response.Content.ReadAsStringAsync();
        var content = Json.Deserialize<Model>(res);

// do whatever you need with the JSON which is in 'content'
// ex: int id = content.Id;

        Navigate();
        return true;
    }
    else
    {
        await JSRuntime.Current.InvokeAsync<string>("alert", "Warning, the credentials you have entered are incorrect.");
        return false;
    }

Where 'model' is your C# model class.

Why can't Python parse this JSON data?

There are two types in this parsing.

  1. Parsing data from a file from a system path
  2. Parsing JSON from remote URL.

From a file, you can use the following

import json
json = json.loads(open('/path/to/file.json').read())
value = json['key']
print json['value']

This arcticle explains the full parsing and getting values using two scenarios.Parsing JSON using Python

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

A little bit easier and it looks exactly like the button in the form. Just use the input and wrap the anchor tag around it.

<a href="#"><input type="button" value="Button Text"></a>

Deleting DataFrame row in Pandas based on column value

just to add another solution, particularly useful if you are using the new pandas assessors, other solutions will replace the original pandas and lose the assessors

df.drop(df.loc[df['line_race']==0].index, inplace=True)

Function is not defined - uncaught referenceerror

Clearing Cache solved the issue for me or you can open it in another browser

index.js

function myFun() {
    $('h2').html("H999999");
}

index.jsp

<html>
<head>
    <title>Reader</title>
</head>
<body>
<h2>${message}</h2>
<button id="hi" onclick="myFun();" type="submit">Hi</button>
</body>
</html>

How can I set the background color of <option> in a <select> element?

_x000D_
_x000D_
select.list1 option.option2
{
    background-color: #007700;
}
_x000D_
<select class="list1">
  <option value="1">Option 1</option>
  <option value="2" class="option2">Option 2</option>
</select>
_x000D_
_x000D_
_x000D_

How to use dashes in HTML-5 data-* attributes in ASP.NET MVC

In mvc 4 Could be rendered with Underscore(" _ ")

Razor:

@Html.ActionLink("Vote", "#", new { id = item.FileId, }, new { @class = "votes", data_fid = item.FileId, data_jid = item.JudgeID, })

Rendered Html

<a class="votes" data-fid="18587" data-jid="9" href="/Home/%23/18587">Vote</a>

How to create a temporary directory/folder in Java?

As discussed in this RFE and its comments, you could call tempDir.delete() first. Or you could use System.getProperty("java.io.tmpdir") and create a directory there. Either way, you should remember to call tempDir.deleteOnExit(), or the file won't be deleted after you're done.

Adding space/padding to a UILabel

Full and correct solution which works in all cases, including stack views, dynamic cells, dynamic number of lines, collection views, animated padding, every character count, and every other situation.

Padding a UILabel, full solution. Updated for 2021.

It turns out there are three things that must be done.

1. Must call textRect#forBounds with the new smaller size

2. Must override drawText with the new smaller size

3. If a dynamically sized cell, must adjust intrinsicContentSize

In the typical example below, the text unit is in a table view, stack view or similar construction, which gives it a fixed width. In the example we want padding of 60,20,20,24.

Thus, we take the "existing" intrinsicContentSize and actually add 80 to the height.

To repeat ...

You have to literally "get" the height calculated "so far" by the engine, and change that value.

I find that process confusing, but, that is how it works. For me, Apple should expose a call named something like "preliminary height calculation".

Secondly we have to actually use the textRect#forBounds call with our new smaller size.

So in textRect#forBounds we first make the size smaller and then call super.

Alert! You must call super after, not before!

If you carefully investigate all the attempts and discussion on this page, that is the exact problem.

Notice some solutions "seem to usually work". This is indeed the exact reason - confusingly you must "call super afterwards", not before.

If you call super "in the wrong order", it usually works, but fails for certain specific text lengths.

Here is an exact visual example of "incorrectly doing super first":

enter image description here

Notice the 60,20,20,24 margins are correct BUT the size calculation is actually wrong, because it was done with the "super first" pattern in textRect#forBounds.

Fixed:

Only now does the textRect#forBounds engine know how to do the calculation properly:

enter image description here

Finally!

Again, in this example the UILabel is being used in the typical situation where width is fixed. So in intrinsicContentSize we have to "add" the overall extra height we want. (You don't need to "add" in any way to the width, that would be meaningless as it is fixed.)

Then in textRect#forBounds you get the bounds "suggested so far" by autolayout, you subtract your margins, and only then call again to the textRect#forBounds engine, that is to say in super, which will give you a result.

Finally and simply in drawText you of course draw in that same smaller box.

Phew!

let UIEI = UIEdgeInsets(top: 60, left: 20, bottom: 20, right: 24) // as desired

override var intrinsicContentSize:CGSize {
    numberOfLines = 0       // don't forget!
    var s = super.intrinsicContentSize
    s.height = s.height + UIEI.top + UIEI.bottom
    s.width = s.width + UIEI.left + UIEI.right
    return s
}

override func drawText(in rect:CGRect) {
    let r = rect.inset(by: UIEI)
    super.drawText(in: r)
}

override func textRect(forBounds bounds:CGRect,
                           limitedToNumberOfLines n:Int) -> CGRect {
    let b = bounds
    let tr = b.inset(by: UIEI)
    let ctr = super.textRect(forBounds: tr, limitedToNumberOfLines: 0)
    // that line of code MUST be LAST in this function, NOT first
    return ctr
}

Once again. Note that the answers on this and other QA that are "almost" correct suffer the problem in the first image above - the "super is in the wrong place". You must force the size bigger in intrinsicContentSize and then in textRect#forBounds you must first shrink the first-suggestion bounds and then call super.

Summary: you must "call super last" in textRect#forBounds

That's the secret.

Note that you do not need to and should not need to additionally call invalidate, sizeThatFits, needsLayout or any other forcing call. A correct solution should work properly in the normal autolayout draw cycle.

Can't push image to Amazon ECR - fails with "no basic auth credentials"

My issue was having multiple AWS credentials; default and dev. Since I was trying to deploy to dev this worked:

$(aws ecr get-login --no-include-email --region eu-west-1 --profile dev | sed 's|https://||')

Spring JPA selecting specific columns

In my opinion this is great solution:

interface PersonRepository extends Repository<Person, UUID> {

    <T> Collection<T> findByLastname(String lastname, Class<T> type);
}

and using it like so

void someMethod(PersonRepository people) {

  Collection<Person> aggregates =
    people.findByLastname("Matthews", Person.class);

  Collection<NamesOnly> aggregates =
    people.findByLastname("Matthews", NamesOnly.class);
}