Programs & Examples On #Oracle ucm

Oracle Universal Content Management, now WebCenter Content

WCF, Service attribute value in the ServiceHost directive could not be found

Option One:

This message is often due to an IIS 7 config problem. If you are used to creating a virtual directory pointing to the folder where your service resides, that no longer works. Now, you need to use the "Create Application..." option instead.

Other Options:

Angular 2 change event - model changes

Use the (ngModelChange) event to detect changes on the model

Convert NaN to 0 in javascript

Please try this simple function

var NanValue = function (entry) {
    if(entry=="NaN") {
        return 0.00;
    } else {
        return entry;
    }
}

CSS for grabbing cursors (drag & drop)

I think move would probably be the closest standard cursor value for what you're doing:

move
Indicates something is to be moved.

Safest way to get last record ID from a table

SELECT LAST(row_name) FROM table_name

Save base64 string as PDF at client side with JavaScript

you can use this function to download file from base64.

function downloadPDF(pdf) {
const linkSource = `data:application/pdf;base64,${pdf}`;
const downloadLink = document.createElement("a");
const fileName = "abc.pdf";
downloadLink.href = linkSource;
downloadLink.download = fileName;
downloadLink.click();}

This code will made an anchor tag with href and download file. if you want to use button then you can call click method on your button click.

i hope this will help of you thanks

Setting values of input fields with Angular 6

As an alternate you can use reactive forms. Here is an example: https://stackblitz.com/edit/angular-pqb2xx

Template

<form [formGroup]="mainForm" ng-submit="submitForm()">
  Global Price: <input type="number" formControlName="globalPrice">
  <button type="button" [disabled]="mainForm.get('globalPrice').value === null" (click)="applyPriceToAll()">Apply to all</button>
  <table border formArrayName="orderLines">
  <ng-container *ngFor="let orderLine of orderLines let i=index" [formGroupName]="i">
    <tr>
       <td>{{orderLine.time | date}}</td>
       <td>{{orderLine.quantity}}</td>
       <td><input formControlName="price" type="number"></td>
    </tr>
</ng-container>
  </table>
</form>

Component

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

@Component({
  selector: 'my-app',
  templateUrl: './app.component.html',
  styleUrls: [ './app.component.css' ]
})
export class AppComponent  {
  name = 'Angular 6';
  mainForm: FormGroup;
  orderLines = [
    {price: 10, time: new Date(), quantity: 2},
    {price: 20, time: new Date(), quantity: 3},
    {price: 30, time: new Date(), quantity: 3},
    {price: 40, time: new Date(), quantity: 5}
    ]
  constructor() {
    this.mainForm = this.getForm();
  }

  getForm(): FormGroup {
    return new FormGroup({
      globalPrice: new FormControl(),
      orderLines: new FormArray(this.orderLines.map(this.getFormGroupForLine))
    })
  }

  getFormGroupForLine(orderLine: any): FormGroup {
    return new FormGroup({
      price: new FormControl(orderLine.price)
    })
  }

  applyPriceToAll() {
    const formLines = this.mainForm.get('orderLines') as FormArray;
    const globalPrice = this.mainForm.get('globalPrice').value;
    formLines.controls.forEach(control => control.get('price').setValue(globalPrice));
    // optionally recheck value and validity without emit event.
  }

  submitForm() {

  }
}

Show Error on the tip of the Edit Text Android

you could use an onchange event to trigger a validation and then you can display a toast if this is enough for you

How to initialize an array of custom objects

Maybe you mean like this? I like to make an object and use Format-Table:

> $array = @()
> $object = New-Object -TypeName PSObject
> $object | Add-Member -Name 'Name' -MemberType Noteproperty -Value 'Joe'
> $object | Add-Member -Name 'Age' -MemberType Noteproperty -Value 32
> $object | Add-Member -Name 'Info' -MemberType Noteproperty -Value 'something about him'
> $array += $object
> $array | Format-Table

Name                                                                        Age Info
----                                                                        --- ----
Joe                                                                          32  something about him

This will put all objects you have in the array in columns according to their properties.

Tip: Using -auto sizes the table better

> $array | Format-Table -Auto

Name Age Info
---- --- ----
Joe   32 something about him

You can also specify which properties you want in the table. Just separate each property name with a comma:

> $array | Format-Table Name, Age -Auto

Name Age
---- ---
Joe   32

How to fix Warning Illegal string offset in PHP

1.

 if(1 == @$manta_option['iso_format_recent_works']){
      $theme_img = 'recent_works_thumbnail';
 } else {
      $theme_img = 'recent_works_iso_thumbnail';
 }

2.

if(isset($manta_option['iso_format_recent_works']) && 1 == $manta_option['iso_format_recent_works']){
    $theme_img = 'recent_works_thumbnail';
} else {
    $theme_img = 'recent_works_iso_thumbnail';
}

3.

if (!empty($manta_option['iso_format_recent_works']) && $manta_option['iso_format_recent_works'] == 1){
}
else{
}

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

First of all you use here two strings: "" marks a string it may be ""-empty "s"- string of lenght 1 or "aaa" string of lenght 3, while '' marks chars . In order to be able to do String str = "a" + "aaa" + 'a' you must use method Character.toString(char c) as @Thomas Keene said so an example would be String str = "a" + "aaa" + Character.toString('a')

How to handle notification when app in background in Firebase

I had same problem. After some digging why my MainActivity is called with intent without data I realized that my LAUNCHER activity (as in Manifest) is SplashActivity. There I found the message data and forwarded them to MainActivity. Works like sharm. I beleive this can help someone.

Thanks for all another answers.

How to get the IP address of the docker host from inside a docker container

The only way is passing the host information as environment when you create a container

run --env <key>=<value>

Multipart forms from C# client

In the version of .NET I am using you also have to do this:

System.Net.ServicePointManager.Expect100Continue = false;

If you don't, the HttpWebRequest class will automatically add the Expect:100-continue request header which fouls everything up.

Also I learned the hard way that you have to have the right number of dashes. whatever you say is the "boundary" in the Content-Type header has to be preceded by two dashes

--THEBOUNDARY

and at the end

--THEBOUNDARY--

exactly as it does in the example code. If your boundary is a lot of dashes followed by a number then this mistake won't be obvious by looking at the http request in a proxy server

How can I make my website's background transparent without making the content (images & text) transparent too?

I think the simplest solution, rather than making the body element partially transparent, would be to add an extra div to hold the background, and change the opacity there, instead.

So you would add a div like:

<div id="background"></div>

And move your body element's background CSS to it, as well as some additional positioning properties, like this:

#background {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-image: url('images/background.jpg');
    background-repeat: no-repeat;
    background-attachment: fixed;
    background-size: 100%;
    opacity: 0.8;
    filter:alpha(opacity=80);
}

Here's an example: http://jsfiddle.net/nbVg4/4/

How can I recover a lost commit in Git?

Before answering, let's add some background, explaining what this HEAD is.

First of all what is HEAD?

HEAD is simply a reference to the current commit (latest) on the current branch.
There can only be a single HEAD at any given time (excluding git worktree).

The content of HEAD is stored inside .git/HEAD and it contains the 40 bytes SHA-1 of the current commit.


detached HEAD

If you are not on the latest commit - meaning that HEAD is pointing to a prior commit in history it's called detached HEAD.

Enter image description here

On the command line, it will look like this - SHA-1 instead of the branch name since the HEAD is not pointing to the tip of the current branch:

Enter image description here

Enter image description here


A few options on how to recover from a detached HEAD:


git checkout

git checkout <commit_id>
git checkout -b <new branch> <commit_id>
git checkout HEAD~X // x is the number of commits t go back

This will checkout new branch pointing to the desired commit.
This command will checkout to a given commit.
At this point, you can create a branch and start to work from this point on.

# Checkout a given commit.
# Doing so will result in a `detached HEAD` which mean that the `HEAD`
# is not pointing to the latest so you will need to checkout branch
# in order to be able to update the code.
git checkout <commit-id>

# Create a new branch forked to the given commit
git checkout -b <branch name>

git reflog

You can always use the reflog as well.
git reflog will display any change which updated the HEAD and checking out the desired reflog entry will set the HEAD back to this commit.

Every time the HEAD is modified there will be a new entry in the reflog

git reflog
git checkout HEAD@{...}

This will get you back to your desired commit

Enter image description here


git reset --hard <commit_id>

"Move" your HEAD back to the desired commit.

# This will destroy any local modifications.
# Don't do it if you have uncommitted work you want to keep.
git reset --hard 0d1d7fc32

# Alternatively, if there's work to keep:
git stash
git reset --hard 0d1d7fc32
git stash pop
# This saves the modifications, then reapplies that patch after resetting.
# You could get merge conflicts if you've modified things which were
# changed since the commit you reset to.
  • Note: (Since Git 2.7) you can also use the git rebase --no-autostash as well.

git revert <sha-1>

"Undo" the given commit or commit range.
The reset command will "undo" any changes made in the given commit.
A new commit with the undo patch will be committed while the original commit will remain in the history as well.

# Add a new commit with the undo of the original one.
# The <sha-1> can be any commit(s) or commit range
git revert <sha-1>

This schema illustrates which command does what.
As you can see there, reset && checkout modify the HEAD.

Enter image description here

How to get input text value from inside td

Ah I think a understand now. Have a look if this really is what you want:

$(".start").keyup(function(){
    $(this).closest('tr').find("input").each(function() {
        alert(this.value)
    });
});

This will give you all input values of a row.

Update:
To get the value of not all elements you can use :not():

$(this).closest('tr').find("input:not([name^=desc][name^=phone])").each(function() {
     alert(this.value)
});

Actually I am not 100% sure whether it works this way, maybe you have to use two nots instead of this one combining both conditions.

Powershell: Get FQDN Hostname

It can also be retrieved from the registry:

Get-ItemProperty -Path 'HKLM:\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters' |
   % { $_.'NV HostName', $_.'NV Domain' -join '.' }

How to implement a Map with multiple keys?

Depending on how it will be used, you can either do this with two maps Map<K1, V> and Map<K2, V> or with two maps Map<K1, V> and Map<K2, K1>. If one of the keys is more permanent than the other, the second option may make more sense.

Android list view inside a scroll view

  • It is not possible to use Scroll-view inside List-view as List-view already has scrolling property.
  • To use list-view inside Scroll-view you can follow these steps which worked for me :

    1) Create NonScrollListView java file that disable the default scrolling property of list-view. and code is below

    package your-package-structure;
    
    import android.content.Context;
    import android.util.AttributeSet;
    import android.view.ViewGroup;
    import android.widget.ListView;
    
    public class NonScrollListView extends ListView {
    
      public NonScrollListView(Context context) {
          super(context);
      }
      public NonScrollListView(Context context, AttributeSet attrs) {
          super(context, attrs);
      }
      public NonScrollListView(Context context, AttributeSet attrs, int defStyle) {
          super(context, attrs, defStyle);
      }
      @Override
      public void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        int heightMeasureSpec_custom = MeasureSpec.makeMeasureSpec(
                Integer.MAX_VALUE >> 2, MeasureSpec.AT_MOST);
        super.onMeasure(widthMeasureSpec, heightMeasureSpec_custom);
        ViewGroup.LayoutParams params = getLayoutParams();
        params.height = getMeasuredHeight();
      }
    }
    

    2) Now create xml file which which has NestedScrollView and inside this use NonScrollListView for listing your items. This will make your entire screen to scroll with all the views.

            <LinearLayout
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:layout_weight="1"
                android:orientation="vertical">
                <ViewFlipper
    
                    android:id="@+id/v_flipper"
                    android:layout_width="match_parent"
                    android:layout_height="130dp">
                </ViewFlipper>
                <TextView
                    android:layout_width="match_parent"
                    android:layout_height="wrap_content"
    
                    android:text="SHOP"
                    android:textSize="15dp"
                    android:textStyle="bold"
                    android:gravity="center"
                    android:padding="5dp"
                    android:layout_marginTop="15dp"
                    android:layout_marginBottom="5dp"
                    android:layout_marginLeft="8dp"
                    android:layout_marginRight="8dp"/>
                <View
                    android:layout_width="match_parent"
                    android:layout_height="1dp"
    
                    android:layout_marginBottom="8dp"
                    android:layout_marginLeft="8dp"
                    android:layout_marginRight="8dp"
                    android:background="#ddd"/>
            </LinearLayout>
            <LinearLayout
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:orientation="vertical"
                android:layout_weight="1"
                >
                <com.abc.xyz.NonScrollListView
                    android:id="@+id/listview"
    
                    android:divider="@null"
                    android:layout_width="match_parent"
                    android:layout_marginBottom="10dp"
                    android:layout_height="match_parent"
                    android:padding="8dp">
                </com.abc.xyz.NonScrollListView>
            </LinearLayout>
    
           <LinearLayout
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
    
                android:gravity="bottom">
                <include layout="@layout/footer" />
            </LinearLayout>
    
        </LinearLayout>
    

    3) Now in java class i.e, home.java define NonScrollListView instead of Listview.

    package comabc.xyz.landscapeapp;
    import android.content.Intent;
    import android.support.annotation.NonNull;
    import android.support.annotation.Nullable;
    import android.support.v4.app.Fragment;
    import android.os.Bundle;
    import android.support.v4.app.FragmentTransaction;
    import android.util.Log;
    import android.view.LayoutInflater;
    import android.view.View;
    import android.view.ViewGroup;
    import android.widget.AdapterView;
    import android.widget.Button;
    import android.widget.ImageView;
    
    import android.widget.ListView;
    import android.widget.Toast;
    import android.widget.Toolbar;
    import android.widget.ViewFlipper;
    

    public class home extends Fragment { int pos = 0; ViewFlipper v_flipper;

    @Nullable
    @Override
    public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
        View view = inflater.inflate(R.layout.activity_home, container, false);
        return view;
    }
    
    @Override
    public void onViewCreated(@NonNull final View view, @Nullable Bundle savedInstanceState) {
        NonScrollListView listView = (NonScrollListView) view.findViewById(R.id.listview);
        customAdapter customAdapter = new customAdapter(getActivity());
        listView.setAdapter(customAdapter);
        listView.setFocusable(false);
    
        customAdapter.notifyDataSetChanged();
        listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
                Log.d("listview click", "onItemClick: ");
               /* FragmentTransaction fr = getFragmentManager().beginTransaction().replace(R.id.fragment_container, new productdisplay());
    
                fr.putExtra("Position", position);
                fr.addToBackStack("tag");
                fr.commit();*/
                Intent intent = new Intent(getActivity(), productdisplay.class);
                intent.putExtra("Position", position);
                startActivity(intent);
            }
        });
    
    
        //image slider
        int images[] = {R.drawable.slide1, R.drawable.slide2, R.drawable.slide3};
        v_flipper = view.findViewById(R.id.v_flipper);
        for (int image : images) {
            flipperImages(image);
    
        }
    }
    
    private void flipperImages(int image) {
        ImageView imageView = new ImageView(getActivity());
        imageView.setBackgroundResource(image);
    
        v_flipper.addView(imageView);
        v_flipper.setFlipInterval(4000);
        v_flipper.setAutoStart(true);
    
        v_flipper.setInAnimation(getActivity(), android.R.anim.slide_in_left);
        v_flipper.setOutAnimation(getActivity(), android.R.anim.slide_out_right);
    }
    }
    

    Note: I used Fragments here.

Is it possible to format an HTML tooltip (title attribute)?

Try using entity codes such as &#013; for CR, &#010; for LF, and &#009; for TAB.

For example:

_x000D_
_x000D_
<div title="1)&#009;A&#013;&#010;2)&#009;B">Hover Me</div>
_x000D_
_x000D_
_x000D_

How to kill a thread instantly in C#?

The reason it's hard to just kill a thread is because the language designers want to avoid the following problem: your thread takes a lock, and then you kill it before it can release it. Now anyone who needs that lock will get stuck.

What you have to do is use some global variable to tell the thread to stop. You have to manually, in your thread code, check that global variable and return if you see it indicates you should stop.

Explanation on Integer.MAX_VALUE and Integer.MIN_VALUE to find min and max value in an array

By initializing the min/max values to their extreme opposite, you avoid any edge cases of values in the input: Either one of min/max is in fact one of those values (in the case where the input consists of only one of those values), or the correct min/max will be found.

It should be noted that primitive types must have a value. If you used Objects (ie Integer), you could initialize value to null and handle that special case for the first comparison, but that creates extra (needless) code. However, by using these values, the loop code doesn't need to worry about the edge case of the first comparison.

Another alternative is to set both initial values to the first value of the input array (never a problem - see below) and iterate from the 2nd element onward, since this is the only correct state of min/max after one iteration. You could iterate from the 1st element too - it would make no difference, other than doing one extra (needless) iteration over the first element.

The only sane way of dealing with inout of size zero is simple: throw an IllegalArgumentException, because min/max is undefined in this case.

ETag vs Header Expires

One additional thing I would like to mention that some of the answers may have missed is the downside to having both ETags and Expires/Cache-control in your headers.

Depending on your needs it may just add extra bytes in your headers which may increase packets which means more TCP overhead. Again, you should see if the overhead of having both things in your headers is necessary or will it just add extra weight in your requests which reduces performance.

You can read more about it on this excellent blog post by Kyle Simpson: http://calendar.perfplanet.com/2010/bloated-request-response-headers/

Why is Maven downloading the maven-metadata.xml every time?

It is possibly to use the flag -o,--offline "Work offline" to prevent that.

Like this:

maven compile -o

How do I discard unstaged changes in Git?

If you aren't interested in keeping the unstaged changes (especially if the staged changes are new files), I found this handy:

git diff | git apply --reverse

Jquery - How to get the style display attribute "none / block"

You could try:

$j('div.contextualError.ckgcellphone').css('display')

How add class='active' to html menu with php

CALL common.php
<style>
    .ddsmoothmenu ul li{float: left; padding: 0 20px;}
    .ddsmoothmenu ul li a{display: block;
  padding: 40px 15px 20px 15px;
  color: #4b4b4b;
  font-size: 13px;
  font-family: 'Open Sans', Arial, sans-serif;
  text-align: right;
  text-transform: uppercase;
  margin-left: 1px; color: #fff; background: #000;}
    .current .test{  background: #2767A3; color: #fff;}
</style>
<div class="span8 ddsmoothmenu">
<!-- // Dropdown Menu // -->
<ul id="dropdown-menu" class="fixed">
    <li class="<?php if(basename($_SERVER['SCRIPT_NAME']) == 'index.php'){echo 'current'; }else { echo ''; } ?>"><a href="index.php" class="test">Home  <i>::</i> <span>welcome</span></a></li>
    <li class="<?php if(basename($_SERVER['SCRIPT_NAME']) == 'about.php'){echo 'current'; }else { echo ''; } ?>"><a href="about.php" class="test">About us <i>::</i> <span>Who we are</span></a></li>
    <li class="<?php if(basename($_SERVER['SCRIPT_NAME']) == 'course.php'){echo 'current'; }else { echo ''; } ?>"><a href="course.php">Our Courses  <i>::</i> <span>What we do</span></a></li>
</ul><!-- end #dropdown-menu -->

</div><!-- end .span8 -->

add each page
<?php include('common.php'); ?>

How do I get the web page contents from a WebView?

You also need to annotate the method with @JavascriptInterface if your targetSdkVersion is >= 17 - because there is new security requirements in SDK 17, i.e. all javascript methods must be annotated with @JavascriptInterface. Otherwise you will see error like: Uncaught TypeError: Object [object Object] has no method 'processHTML' at null:1

Is there a template engine for Node.js?

You should be able to use mustache.js, if it doesn't work send me the issues and I'll get it fixed because I'm about to be using them in node.js anyway.

http://github.com/janl/mustache.js

I know that it works without a DOM because a bunch of CouchDB standalone apps are using it in a Spidermonkey view server.

A Simple AJAX with JSP example

I have used jQuery AJAX to make AJAX requests.

Check the following code:

<html>
<head>
    <script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.4/jquery.min.js"></script>
    <script type="text/javascript">
        $(document).ready(function() {
            $('#call').click(function ()
            {
                $.ajax({
                    type: "post",
                    url: "testme", //this is my servlet
                    data: "input=" +$('#ip').val()+"&output="+$('#op').val(),
                    success: function(msg){      
                            $('#output').append(msg);
                    }
                });
            });

        });
    </script>
    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
    <title>JSP Page</title>
</head>
<body>
    input:<input id="ip" type="text" name="" value="" /><br></br>
    output:<input id="op" type="text" name="" value="" /><br></br>
    <input type="button" value="Call Servlet" name="Call Servlet" id="call"/>
    <div id="output"></div>
</body>

ASP.Net MVC: Calling a method from a view

This is how you call an instance method on the Controller:

@{
  ((HomeController)this.ViewContext.Controller).Method1();
}

This is how you call a static method in any class

@{
    SomeClass.Method();
}

This will work assuming the method is public and visible to the view.

How can I change or remove HTML5 form validation default error messages?

To set custom error message for HTML 5 validation use,

oninvalid="this.setCustomValidity('Your custom message goes here.')"

and to remove this message when user enters valid data use,

onkeyup="setCustomValidity('')"

Hope this works for you. Enjoy ;)

Remove border from buttons

The usual trick is to make the image itself part of a link instead of a button. Then, you bind the "click" event with a custom handler.

Frameworks like Jquery-UI or Bootstrap does this out of the box. Using one of them may ease a lot the whole application conception by the way.

Unable to create a constant value of type Only primitive types or enumeration types are supported in this context

This cannot work because ppCombined is a collection of objects in memory and you cannot join a set of data in the database with another set of data that is in memory. You can try instead to extract the filtered items personProtocol of the ppCombined collection in memory after you have retrieved the other properties from the database:

var persons = db.Favorites
    .Where(f => f.userId == userId)
    .Join(db.Person, f => f.personId, p => p.personId, (f, p) =>
        new // anonymous object
        {
            personId = p.personId,
            addressId = p.addressId,   
            favoriteId = f.favoriteId,
        })
    .AsEnumerable() // database query ends here, the rest is a query in memory
    .Select(x =>
        new PersonDTO
        {
            personId = x.personId,
            addressId = x.addressId,   
            favoriteId = x.favoriteId,
            personProtocol = ppCombined
                .Where(p => p.personId == x.personId)
                .Select(p => new PersonProtocol
                {
                    personProtocolId = p.personProtocolId,
                    activateDt = p.activateDt,
                    personId = p.personId
                })
                .ToList()
        });

bypass invalid SSL certificate in .net core

ServicePointManager.ServerCertificateValidationCallback isn't supported in .Net Core.

Current situation is that it will be a a new ServerCertificateCustomValidationCallback method for the upcoming 4.1.* System.Net.Http contract (HttpClient). .NET Core team are finalizing the 4.1 contract now. You can read about this in here on github

You can try out the pre-release version of System.Net.Http 4.1 by using the sources directly here in CoreFx or on the MYGET feed: https://dotnet.myget.org/gallery/dotnet-core

Current WinHttpHandler.ServerCertificateCustomValidationCallback definition on Github

String.Format not work in TypeScript

You can declare it yourself quite easily:

interface StringConstructor {
    format: (formatString: string, ...replacement: any[]) => string;
}

String.format('','');

This is assuming that String.format is defined elsewhere. e.g. in Microsoft Ajax Toolkit : http://www.asp.net/ajaxlibrary/Reference.String-format-Function.ashx

How to make graphics with transparent background in R using ggplot2?

There is also a plot.background option in addition to panel.background:

df <- data.frame(y=d,x=1)
p <- ggplot(df) + stat_boxplot(aes(x = x,y=y)) 
p <- p + opts(
    panel.background = theme_rect(fill = "transparent",colour = NA), # or theme_blank()
    panel.grid.minor = theme_blank(), 
    panel.grid.major = theme_blank(),
    plot.background = theme_rect(fill = "transparent",colour = NA)
)
#returns white background
png('tr_tst2.png',width=300,height=300,units="px",bg = "transparent")
print(p)
dev.off()

For some reason, the uploaded image is displaying differently than on my computer, so I've omitted it. But for me, I get a plot with an entirely gray background except for the box part of the boxplot which is still white. That can be changed using the fill aesthetic in the boxplot geom as well, I believe.

Edit

ggplot2 has since been updated and the opts() function has been deprecated. Currently, you would use theme() instead of opts() and element_rect() instead of theme_rect(), etc.

Erasing elements from a vector

Calling erase will invalidate iterators, you could use:

void erase(std::vector<int>& myNumbers_in, int number_in)
{
    std::vector<int>::iterator iter = myNumbers_in.begin();
    while (iter != myNumbers_in.end())
    {
        if (*iter == number_in)
        {
            iter = myNumbers_in.erase(iter);
        }
        else
        {
           ++iter;
        }
    }

}

Or you could use std::remove_if together with a functor and std::vector::erase:

struct Eraser
{
    Eraser(int number_in) : number_in(number_in) {}
    int number_in;
    bool operator()(int i) const
    {
        return i == number_in;
    }
};

std::vector<int> myNumbers;
myNumbers.erase(std::remove_if(myNumbers.begin(), myNumbers.end(), Eraser(number_in)), myNumbers.end());

Instead of writing your own functor in this case you could use std::remove:

std::vector<int> myNumbers;
myNumbers.erase(std::remove(myNumbers.begin(), myNumbers.end(), number_in), myNumbers.end());

In C++11 you could use a lambda instead of a functor:

std::vector<int> myNumbers;
myNumbers.erase(std::remove_if(myNumbers.begin(), myNumbers.end(), [number_in](int number){ return number == number_in; }), myNumbers.end());

In C++17 std::experimental::erase and std::experimental::erase_if are also available, in C++20 these are (finally) renamed to std::erase and std::erase_if (note: in Visual Studio 2019 you'll need to change your C++ language version to the latest experimental version for support):

std::vector<int> myNumbers;
std::erase_if(myNumbers, Eraser(number_in)); // or use lambda

or:

std::vector<int> myNumbers;
std::erase(myNumbers, number_in);

AngularJs event to call after content is loaded

var myTestApp = angular.module("myTestApp", []); 
myTestApp.controller("myTestController", function($scope, $window) {
$window.onload = function() {
 alert("is called on page load.");
};
});

Setting up MySQL and importing dump within Dockerfile

The latest version of the official mysql docker image allows you to import data on startup. Here is my docker-compose.yml

data:
  build: docker/data/.
mysql:
  image: mysql
  ports:
    - "3307:3306"
  environment:
    MYSQL_ROOT_PASSWORD: 1234
  volumes:
    - ./docker/data:/docker-entrypoint-initdb.d
  volumes_from:
    - data

Here, I have my data-dump.sql under docker/data which is relative to the folder the docker-compose is running from. I am mounting that sql file into this directory /docker-entrypoint-initdb.d on the container.

If you are interested to see how this works, have a look at their docker-entrypoint.sh in GitHub. They have added this block to allow importing data

    echo
    for f in /docker-entrypoint-initdb.d/*; do
        case "$f" in
            *.sh)  echo "$0: running $f"; . "$f" ;;
            *.sql) echo "$0: running $f"; "${mysql[@]}" < "$f" && echo ;;
            *)     echo "$0: ignoring $f" ;;
        esac
        echo
    done

An additional note, if you want the data to be persisted even after the mysql container is stopped and removed, you need to have a separate data container as you see in the docker-compose.yml. The contents of the data container Dockerfile are very simple.

FROM n3ziniuka5/ubuntu-oracle-jdk:14.04-JDK8

VOLUME /var/lib/mysql

CMD ["true"]

The data container doesn't even have to be in start state for persistence.

Redirect parent window from an iframe action

window.top.location.href = "http://www.example.com"; 

Will redirect the top most parent Iframe.

window.parent.location.href = "http://www.example.com"; 

Will redirect the parent iframe.

Difference between JPanel, JFrame, JComponent, and JApplet

You might find it useful to lookup the classes on oracle. Eg:

http://download.oracle.com/javase/1.4.2/docs/api/javax/swing/JFrame.html

There you can see that JFrame extends JComponent and JContainer.

JComponent is a a basic object that can be drawn, JContainer extends this so that you can add components to it. JPanel and JFrame both extend JComponent as you can add things to them. JFrame provides a window, whereas JPanel is just a panel that goes inside a window. If that makes sense.

Is there a difference between PhoneGap and Cordova commands?

Above, Abhishek mentions the command line differences specified in two URLS:

  1. PhoneGap: http://docs.phonegap.com/en/edge/guide_cli_index.md.html

  2. Cordova: http://cordova.apache.org/docs/en/3.0.0/guide_cli_index.md.html#The%20Command-line%20Interface

One thing to point out is that, as of this post, the phonegap one looks to be almost the same as the cordova one, and is probably not an accurate image of the command line option differences. As such, I installed both on my system so I could look at the differences.

These are just a few of them. Hopefully they are brought more in sync sometime. If anyone has better information, please tell me.

  1. Adding platforms seems to be done differently between the two commands ( phonegap uses "install" command, cordova uses "platform add" command )
  2. Adding/creating projects seems to be the same between the two commands ( same command line options supported )
  3. Obviously, as has been stated, phonegap can use PhoneGap Build, so it has the corresponding options to trigger that or local builds
  4. Quite a few other significant command line differences, simply by running "cordova help" and "phonegap help" and comparing the two.

I guess my point is that the phonegap CLI documention mentioned quite often is not really for the phonegap CLI, but for the cordova CLI, at this time. Please tell me if I am missing something. Thanks.

PowerShell and the -contains operator

The -Contains operator doesn't do substring comparisons and the match must be on a complete string and is used to search collections.

From the documentation you linked to:

-Contains Description: Containment operator. Tells whether a collection of reference values includes a single test value.

In the example you provided you're working with a collection containing just one string item.

If you read the documentation you linked to you'll see an example that demonstrates this behaviour:

Examples:

PS C:\> "abc", "def" -Contains "def"
True

PS C:\> "Windows", "PowerShell" -Contains "Shell"
False  #Not an exact match

I think what you want is the -Match operator:

"12-18" -Match "-"

Which returns True.

Important: As pointed out in the comments and in the linked documentation, it should be noted that the -Match operator uses regular expressions to perform text matching.

Bootstrap 3 Glyphicons are not working

I was having a similar issue. Being a total noob at bootstrap, it turned out i was missing the glyphicon keyword before the icon name.

<span class="glyphicon-search"></span>

Should have been

<span class="glyphicon glyphicon-search"></span>

Printing to the console in Google Apps Script?

Even though Logger.log() is technically the correct way to output something to the console, it has a few annoyances:

  1. The output can be an unstructured mess and hard to quickly digest.
  2. You have to first run the script, then click View / Logs, which is two extra clicks (one if you remember the Ctrl+Enter keyboard shortcut).
  3. You have to insert Logger.log(playerArray), and then after debugging you'd probably want to remove Logger.log(playerArray), hence an additional 1-2 more steps.
  4. You have to click on OK to close the overlay (yet another extra click).

Instead, whenever I want to debug something I add breakpoints (click on line number) and press the Debug button (bug icon). Breakpoints work well when you are assigning something to a variable, but not so well when you are initiating a variable and want to peek inside of it at a later point, which is similar to what the op is trying to do. In this case, I would force a break condition by entering "x" (x marks the spot!) to throw a run-time error:

enter image description here

Compare with viewing Logs:

enter image description here

The Debug console contains more information and is a lot easier to read than the Logs overlay. One minor benefit with this method is that you never have to worry about polluting your code with a bunch of logging commands if keeping clean code is your thing. Even if you enter "x", you are forced to remember to remove it as part of the debugging process or else your code won't run (built-in cleanup measure, yay).

How to specify different Debug/Release output directories in QMake .pro file

This is my Makefile for different debug/release output directories. This Makefile was tested successfully on Ubuntu linux. It should work seamlessly on Windows provided that Mingw-w64 is installed correctly.

ifeq ($(OS),Windows_NT)
    ObjExt=obj
    mkdir_CMD=mkdir
    rm_CMD=rmdir /S /Q
else
    ObjExt=o
    mkdir_CMD=mkdir -p
    rm_CMD=rm -rf
endif

CC     =gcc
CFLAGS =-Wall -ansi
LD     =gcc

OutRootDir=.
DebugDir  =Debug
ReleaseDir=Release


INSTDIR =./bin
INCLUDE =.

SrcFiles=$(wildcard *.c)
EXEC_main=myapp

OBJ_C_Debug   =$(patsubst %.c,  $(OutRootDir)/$(DebugDir)/%.$(ObjExt),$(SrcFiles))
OBJ_C_Release =$(patsubst %.c,  $(OutRootDir)/$(ReleaseDir)/%.$(ObjExt),$(SrcFiles))

.PHONY: Release Debug cleanDebug cleanRelease clean

# Target specific variables
release: CFLAGS += -O -DNDEBUG
debug:   CFLAGS += -g

################################################
#Callable Targets
release: $(OutRootDir)/$(ReleaseDir)/$(EXEC_main)
debug:   $(OutRootDir)/$(DebugDir)/$(EXEC_main)

cleanDebug:
    -$(rm_CMD) "$(OutRootDir)/$(DebugDir)"
    @echo cleanDebug done

cleanRelease:
    -$(rm_CMD) "$(OutRootDir)/$(ReleaseDir)"
    @echo cleanRelease done

clean: cleanDebug cleanRelease
################################################

# Pattern Rules
# Multiple targets cannot be used with pattern rules [https://www.gnu.org/software/make/manual/html_node/Multiple-Targets.html]
$(OutRootDir)/$(ReleaseDir)/%.$(ObjExt): %.c | $(OutRootDir)/$(ReleaseDir)
    $(CC) -I$(INCLUDE) $(CFLAGS) -c $< -o"$@"

$(OutRootDir)/$(DebugDir)/%.$(ObjExt):   %.c | $(OutRootDir)/$(DebugDir)
    $(CC) -I$(INCLUDE) $(CFLAGS) -c $< -o"$@"

# Create output directory
$(OutRootDir)/$(ReleaseDir) $(OutRootDir)/$(DebugDir) $(INSTDIR):
    -$(mkdir_CMD) $@

# Create the executable
# Multiple targets [https://www.gnu.org/software/make/manual/html_node/Multiple-Targets.html]
$(OutRootDir)/$(ReleaseDir)/$(EXEC_main): $(OBJ_C_Release)
$(OutRootDir)/$(DebugDir)/$(EXEC_main):   $(OBJ_C_Debug)
$(OutRootDir)/$(ReleaseDir)/$(EXEC_main) $(OutRootDir)/$(DebugDir)/$(EXEC_main):
    $(LD) $^ -o$@

How to keep one variable constant with other one changing with row in excel

There are two kinds of cell reference, and it's really valuable to understand them well.

One is relative reference, which is what you get when you just type the cell: A5. This reference will be adjusted when you paste or fill the formula into other cells.

The other is absolute reference, and you get this by adding dollar signs to the cell reference: $A$5. This cell reference will not change when pasted or filled.

A cool but rarely used feature is that row and column within a single cell reference may be independent: $A5 and A$5. This comes in handy for producing things like multiplication tables from a single formula.

How to make VS Code to treat other file extensions as certain language?

This works for me.

enter image description here

{
"files.associations": {"*.bitesize": "yaml"}
 }

Intermediate language used in scalac?

maybe this will help you out:

http://lampwww.epfl.ch/~paltherr/phd/altherr-phd.pdf

or this page:

www.scala-lang.org/node/6372‎

Usage of MySQL's "IF EXISTS"

SELECT IF((
     SELECT count(*) FROM gdata_calendars 
     WHERE `group` =  ? AND id = ?)
,1,0);

For Detail explanation you can visit here

Why shouldn't `&apos;` be used to escape single quotes?

&apos; is not part of the HTML 4 standard.

&quot; is, though, so is fine to use.

Query to get the names of all tables in SQL Server 2008 Database

In a single database - yes:

USE your_database
SELECT name FROM sys.tables

Getting all tables across all databases - only with a hack.... see this SO question for several approaches how to do that: How do I list all tables in all databases in SQL Server in a single result set?

Sharing link on WhatsApp from mobile website (not application) for Android

Currently, it's very easy to achieve this. You only need to add the following code to your pages:

<a href="whatsapp://send?text=<<HERE GOES THE URL ENCODED TEXT YOU WANT TO SHARE>>" data-action="share/whatsapp/share">Share via Whatsapp</a>

And that's it. No Javascript needed, nothing else needed. Of course you can style it as you want and include a nice Whatsapp icon.

I tested this in my Android device with Google Chrome. The versions:

  • Android 4.1.2 (Jelly Bean)
  • Chrome Mobile 37.0.2062.117. Also tested on Firefox Mobile 31.0.
  • Whatsapp V 2.11.399

It also works on iOS. I've made a quick test on an iPhone 5 with Safari and it works as well.

Hope this helps someone. :-)

How to set border on jPanel?

BorderLayout(int Gap, int Gap) or GridLayout(int Gap, int Gap, int Gap, int Gap)

why paint Border() inside paintComponent( ...)

    Border line, raisedbevel, loweredbevel, title, empty;
    line = BorderFactory.createLineBorder(Color.black);
    raisedbevel = BorderFactory.createRaisedBevelBorder();
    loweredbevel = BorderFactory.createLoweredBevelBorder();
    title = BorderFactory.createTitledBorder("");
    empty = BorderFactory.createEmptyBorder(4, 4, 4, 4);
    Border compound = BorderFactory.createCompoundBorder(empty, xxx);
    Color crl = (Color.blue);
    Border compound1 = BorderFactory.createCompoundBorder(empty, xxx);

Nginx 403 forbidden for all files

We had the same issue, using Plesk Onyx 17. Instead of messing up with rights etc., solution was to add nginx user into psacln group, in which all the other domain owners (users) were:

usermod -aG psacln nginx

Now nginx has rights to access .htaccess or any other file necessary to properly show the content.

On the other hand, also make sure that Apache is in psaserv group, to serve static content:

usermod -aG psaserv apache

And don't forget to restart both Apache and Nginx in Plesk after! (and reload pages with Ctrl-F5)

getElementById returns null?

It can be caused by:

  1. Invalid HTML syntax (some tag is not closed or similar error)
  2. Duplicate IDs - there are two HTML DOM elements with the same ID
  3. Maybe element you are trying to get by ID is created dynamically (loaded by ajax or created by script)?

Please, post your code.

Concatenating variables and strings in React

you can simply do this..

 <img src={"http://img.example.com/test/" + this.props.url +"/1.jpg"}/>

What does $_ mean in PowerShell?

$_ is an variable which iterates over each object/element passed from the previous | (pipe).

Android 6.0 multiple permissions

My approach is based on Nicks' answer and hopefully is a bit more usable for multiple (as many as needed, not only two) permissions. It suggests adding single-responsibility PermissionsHelper class:

import android.app.Activity;
import android.app.AlertDialog;
import android.content.pm.PackageManager;
import android.support.v4.app.ActivityCompat;
import android.support.v4.content.ContextCompat;
import android.util.Log;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

public class PermissionsHelper {

private static final int REQUEST_ID_MULTIPLE_PERMISSIONS = 100; // any code you want.

public void checkAndRequestPermissions(Activity activity, String... permissions) {
    List<String> listPermissionsNeeded = new ArrayList<>();
    for (String permission : permissions) {
        if (ContextCompat.checkSelfPermission(activity, permission) != PackageManager.PERMISSION_GRANTED) {
            listPermissionsNeeded.add(permission);
        }
    }
    if (!listPermissionsNeeded.isEmpty()) {
        ActivityCompat.requestPermissions(activity, listPermissionsNeeded.toArray(new String[listPermissionsNeeded.size()]), REQUEST_ID_MULTIPLE_PERMISSIONS);
    }
}

public void onRequestPermissionsResult(Activity activity, int requestCode, String permissions[], int[] grantResults) {
    switch (requestCode) {
        case REQUEST_ID_MULTIPLE_PERMISSIONS: {
            Map<String, Integer> perms = new HashMap<>();

            for (String permission : permissions) {
                perms.put(permission, PackageManager.PERMISSION_GRANTED);
            }

            if (grantResults.length > 0) {
                for (int i = 0; i < permissions.length; i++)
                    perms.put(permissions[i], grantResults[i]);

                boolean allPermissionsGranted = true;
                for (String permission1 : permissions) {
                    allPermissionsGranted = allPermissionsGranted && (perms.get(permission1) == PackageManager.PERMISSION_GRANTED);
                }

                if (allPermissionsGranted) {
                    Log.d(PermissionsHelper.class.getSimpleName(), "onRequestPermissionsResult: all permissions granted");
                } else {
                    for (String permission2 : perms.keySet())
                        if (perms.get(permission2) == PackageManager.PERMISSION_GRANTED)
                            perms.remove(permission2);

                    StringBuilder message = new StringBuilder("The app has not been granted permissions:\n\n");
                    for (String permission : perms.keySet()) {
                        message.append(permission);
                        message.append("\n");
                    }
                    message.append("\nHence, it cannot function properly." +
                            "\nPlease consider granting it this permission in phone Settings.");

                    AlertDialog.Builder builder = new AlertDialog.Builder(activity);
                    builder.setTitle(R.string.permission_required)
                            .setMessage(message)
                            .setPositiveButton(android.R.string.ok, (dialog, id) -> dialog.cancel());
                    AlertDialog alert = builder.create();
                    alert.show();
                }
            }
        }
    }
}

}

If one or several required permissions have not been granted by user, the detailed AlertDialog message will be shown to him.

Example of usage in Activity:

private PermissionsHelper permissionsHelper;

@Override
protected void onCreate(@Nullable Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    checkPermissions();

    //any other code
}

@Override
public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
    permissionsHelper.onRequestPermissionsResult(this, requestCode, permissions, grantResults);
}

private void checkPermissions() {
    permissionsHelper = new PermissionsHelper();
    permissionsHelper.checkAndRequestPermissions(this,
            Manifest.permission.READ_EXTERNAL_STORAGE,
            Manifest.permission.ACCESS_FINE_LOCATION,
            Manifest.permission.ACCESS_COARSE_LOCATION);
}

Hope that this will be useful for someone.

jQuery UI DatePicker to show year only

Try this:
add in html following

<input type="text" id="datepicker"/>

Add in js file

$(function() {
   $( "#datepicker" ).datepicker({dateFormat: 'yy',  changeYear: true,  changeMonth: false});
});

Add in css

.ui-datepicker-calendar {
       display: none;
    }
    .ui-datepicker-month {
       display: none;
    }
    .ui-datepicker-prev{
       display: none;
    }
    .ui-datepicker-next{
       display: none;
    }

Working Demo

How to access global js variable in AngularJS directive

I created a working CodePen example demonstrating how to do this the correct way in AngularJS. The Angular $window service should be used to access any global objects since directly accessing window makes testing more difficult.

HTML:

<section ng-app="myapp" ng-controller="MainCtrl">
  Value of global variable read by AngularJS: {{variable1}}
</section>

JavaScript:

// global variable outside angular
var variable1 = true;

var app = angular.module('myapp', []);

app.controller('MainCtrl', ['$scope', '$window', function($scope, $window) {
  $scope.variable1 = $window.variable1;
}]);

How can I set my Cygwin PATH to find javac?

To bring more prominence to the useful comment by @johanvdw:

If you want to ensure your your javac file path is always know when cygwin starts, you may edit your .bash_profile file. In this example you would add export PATH=$PATH:"/cygdrive/C/Program Files/Java/jdk1.6.0_23/bin/" somewhere in the file.

When Cygwin starts, it'll search directories in PATH and this one for executable files to run.

Check if element is visible in DOM

This is a way to determine it for all css properties including visibility:

html:

<div id="element">div content</div>

css:

#element
{
visibility:hidden;
}

javascript:

var element = document.getElementById('element');
 if(element.style.visibility == 'hidden'){
alert('hidden');
}
else
{
alert('visible');
}

It works for any css property and is very versatile and reliable.

mongodb: insert if not exists

Summary

  • You have an existing collection of records.
  • You have a set records that contain updates to the existing records.
  • Some of the updates don't really update anything, they duplicate what you have already.
  • All updates contain the same fields that are there already, just possibly different values.
  • You want to track when a record was last changed, where a value actually changed.

Note, I'm presuming PyMongo, change to suit your language of choice.

Instructions:

  1. Create the collection with an index with unique=true so you don't get duplicate records.

  2. Iterate over your input records, creating batches of them of 15,000 records or so. For each record in the batch, create a dict consisting of the data you want to insert, presuming each one is going to be a new record. Add the 'created' and 'updated' timestamps to these. Issue this as a batch insert command with the 'ContinueOnError' flag=true, so the insert of everything else happens even if there's a duplicate key in there (which it sounds like there will be). THIS WILL HAPPEN VERY FAST. Bulk inserts rock, I've gotten 15k/second performance levels. Further notes on ContinueOnError, see http://docs.mongodb.org/manual/core/write-operations/

    Record inserts happen VERY fast, so you'll be done with those inserts in no time. Now, it's time to update the relevant records. Do this with a batch retrieval, much faster than one at a time.

  3. Iterate over all your input records again, creating batches of 15K or so. Extract out the keys (best if there's one key, but can't be helped if there isn't). Retrieve this bunch of records from Mongo with a db.collectionNameBlah.find({ field : { $in : [ 1, 2,3 ...}) query. For each of these records, determine if there's an update, and if so, issue the update, including updating the 'updated' timestamp.

    Unfortunately, we should note, MongoDB 2.4 and below do NOT include a bulk update operation. They're working on that.

Key Optimization Points:

  • The inserts will vastly speed up your operations in bulk.
  • Retrieving records en masse will speed things up, too.
  • Individual updates are the only possible route now, but 10Gen is working on it. Presumably, this will be in 2.6, though I'm not sure if it will be finished by then, there's a lot of stuff to do (I've been following their Jira system).

How to call a method defined in an AngularJS directive?

Assuming that the action button uses the same controller $scope as the directive, just define function updateMap on $scope inside the link function. Your controller can then call that function when the action button is clicked.

<div ng-controller="MyCtrl">
    <map></map>
    <button ng-click="updateMap()">call updateMap()</button>
</div>
app.directive('map', function() {
    return {
        restrict: 'E',
        replace: true,
        template: '<div></div>',
        link: function($scope, element, attrs) {
            $scope.updateMap = function() {
                alert('inside updateMap()');
            }
        }
    }
});

fiddle


As per @FlorianF's comment, if the directive uses an isolated scope, things are more complicated. Here's one way to make it work: add a set-fn attribute to the map directive which will register the directive function with the controller:

<map set-fn="setDirectiveFn(theDirFn)"></map>
<button ng-click="directiveFn()">call directive function</button>
scope: { setFn: '&' },
link: function(scope, element, attrs) {
    scope.updateMap = function() {
       alert('inside updateMap()');
    }
    scope.setFn({theDirFn: scope.updateMap});
}
function MyCtrl($scope) {
    $scope.setDirectiveFn = function(directiveFn) {
        $scope.directiveFn = directiveFn;
    };
}

fiddle

TortoiseGit-git did not exit cleanly (exit code 1)

  1. Right-click > Revert > Select All
  2. Click OK;
  3. After Revert process is finished, PULL.

Problem solved!

Renaming column names of a DataFrame in Spark Scala

Sometime we have the column name is below format in SQLServer or MySQL table

Ex  : Account Number,customer number

But Hive tables do not support column name containing spaces, so please use below solution to rename your old column names.

Solution:

val renamedColumns = df.columns.map(c => df(c).as(c.replaceAll(" ", "_").toLowerCase()))
df = df.select(renamedColumns: _*)

Disable nginx cache for JavaScript files

I have the following nginx virtual host (static content) for local development work to disable all browser caching:

server {
    listen 8080;
    server_name localhost;

    location / {
        root /your/site/public;
        index index.html;

        # kill cache
        add_header Last-Modified $date_gmt;
        add_header Cache-Control 'no-store, no-cache, must-revalidate, proxy-revalidate, max-age=0';
        if_modified_since off;
        expires off;
        etag off;
    }
}

No cache headers sent:

$ curl -I http://localhost:8080
HTTP/1.1 200 OK
Server: nginx/1.12.1
Date: Mon, 24 Jul 2017 16:19:30 GMT
Content-Type: text/html
Content-Length: 2076
Connection: keep-alive
Last-Modified: Monday, 24-Jul-2017 16:19:30 GMT
Cache-Control: no-store
Accept-Ranges: bytes

Last-Modified is always current time.

How to declare and add items to an array in Python?

In some languages like JAVA you define an array using curly braces as following but in python it has a different meaning:

Java:

int[] myIntArray = {1,2,3};
String[] myStringArray = {"a","b","c"};

However, in Python, curly braces are used to define dictionaries, which needs a key:value assignment as {'a':1, 'b':2}

To actually define an array (which is actually called list in python) you can do:

Python:

mylist = [1,2,3]

or other examples like:

mylist = list()
mylist.append(1)
mylist.append(2)
mylist.append(3)
print(mylist)
>>> [1,2,3]

Sleep for milliseconds

In Unix you can use usleep.

In Windows there is Sleep.

Convert php array to Javascript

It can be done in a safer way.

If your PHP array contains special characters, you need to use rawurlencode() in PHP and then use decodeURIComponent() in JS to escape those. And parse the JSON to native js. Try this:

var data = JSON.parse(
        decodeURIComponent(
            "<?=rawurlencode(json_encode($data));?>"
        )
    );

console.log(data);

How can I call a shell command in my Perl script?

How to run a shell script from a Perl program

1. Using system system($command, @arguments);

For example:

system("sh", "script.sh", "--help" );

system("sh script.sh --help");

System will execute the $command with @arguments and return to your script when finished. You may check $! for certain errors passed to the OS by the external application. Read the documentation for system for the nuances of how various invocations are slightly different.

2. Using exec

This is very similar to the use of system, but it will terminate your script upon execution. Again, read the documentation for exec for more.

3. Using backticks or qx//

my $output = `script.sh --option`;

my $output = qx/script.sh --option/;

The backtick operator and it's equivalent qx//, excute the command and options inside the operator and return that commands output to STDOUT when it finishes.

There are also ways to run external applications through creative use of open, but this is advanced use; read the documentation for more.

Hibernate JPA Sequence (non-Id)

"I don't want to use a trigger or any other thing other than Hibernate itself to generate the value for my property"

In that case, how about creating an implementation of UserType which generates the required value, and configuring the metadata to use that UserType for persistence of the mySequenceVal property?

How can I truncate a string to the first 20 words in PHP?

function limitText($string,$limit){
        if(strlen($string) > $limit){
                $string = substr($string, 0,$limit) . "...";
        }
        return $string;
}

this will return 20 words. I hope it will help

jQuery checkbox onChange

$('input[type=checkbox]').change(function () {
    alert('changed');
});

How do I represent a time only value in .NET?

If you don't want to use a DateTime or TimeSpan, and just want to store the time of day, you could just store the seconds since midnight in an Int32, or (if you don't even want seconds) the minutes since midnight would fit into an Int16. It would be trivial to write the few methods required to access the Hour, Minute and Second from such a value.

The only reason I can think of to avoid DateTime/TimeSpan would be if the size of the structure is critical.

(Of course, if you use a simple scheme like the above wrapped in a class, then it would also be trivial to replace the storage with a TimeSpan in future if you suddenly realise that would give you an advantage)

Java TreeMap Comparator

you can swipe the key and the value. For example

        String[] k = {"Elena", "Thomas", "Hamilton", "Suzie", "Phil"};
        int[] v = {341, 273, 278, 329, 445};
        TreeMap<Integer,String>a=new TreeMap();
        for (int i = 0; i < k.length; i++) 
           a.put(v[i],k[i]);            
        System.out.println(a.firstEntry().getValue()+"\t"+a.firstEntry().getKey());
        a.remove(a.firstEntry().getKey());
        System.out.println(a.firstEntry().getValue()+"\t"+a.firstEntry().getKey());

No numeric types to aggregate - change in groupby() behaviour?

How are you generating your data?

See how the output shows that your data is of 'object' type? the groupby operations specifically check whether each column is a numeric dtype first.

In [31]: data
Out[31]: 
<class 'pandas.core.frame.DataFrame'>
DatetimeIndex: 2557 entries, 2004-01-01 00:00:00 to 2010-12-31 00:00:00
Freq: <1 DateOffset>
Columns: 360 entries, -89.75 to 89.75
dtypes: object(360)

look ?


Did you initialize an empty DataFrame first and then filled it? If so that's probably why it changed with the new version as before 0.9 empty DataFrames were initialized to float type but now they are of object type. If so you can change the initialization to DataFrame(dtype=float).

You can also call frame.astype(float)

How do I use the lines of a file as arguments of a command?

As already mentioned, you can use the backticks or $(cat filename).

What was not mentioned, and I think is important to note, is that you must remember that the shell will break apart the contents of that file according to whitespace, giving each "word" it finds to your command as an argument. And while you may be able to enclose a command-line argument in quotes so that it can contain whitespace, escape sequences, etc., reading from the file will not do the same thing. For example, if your file contains:

a "b c" d

the arguments you will get are:

a
"b
c"
d

If you want to pull each line as an argument, use the while/read/do construct:

while read i ; do command_name $i ; done < filename

Run git pull over all subdirectories

Run the following from the parent directory, plugins in this case:

find . -type d -depth 1 -exec git --git-dir={}/.git --work-tree=$PWD/{} pull origin master \;

To clarify:

  • find . searches the current directory
  • -type d to find directories, not files
  • -depth 1 for a maximum depth of one sub-directory
  • -exec {} \; runs a custom command for every find
  • git --git-dir={}/.git --work-tree=$PWD/{} pull git pulls the individual directories

To play around with find, I recommend using echo after -exec to preview, e.g.:

find . -type d -depth 1 -exec echo git --git-dir={}/.git --work-tree=$PWD/{} status \;

Note: if the -depth 1 option is not available, try -mindepth 1 -maxdepth 1.

Finding duplicate values in MySQL

Building off of levik's answer to get the IDs of the duplicate rows you can do a GROUP_CONCAT if your server supports it (this will return a comma separated list of ids).

SELECT GROUP_CONCAT(id), name, COUNT(*) c FROM documents GROUP BY name HAVING c > 1;

Get the first key name of a JavaScript object

If you decide to use Underscore.js you better do

_.values(ahash)[0]

to get value, or

_.keys(ahash)[0]

to get key.

How to get current time in milliseconds in PHP?

Use this:

function get_millis(){
  list($usec, $sec) = explode(' ', microtime());
  return (int) ((int) $sec * 1000 + ((float) $usec * 1000));
}

Bye

How to force ViewPager to re-instantiate its items

Had the same problem. For me it worked to call

viewPage.setAdapter( adapter );

again which caused reinstantiating the pages again.

Removing a model in rails (reverse of "rails g model Title...")

bundle exec rake db:rollback    
rails destroy model <model_name>

When you generate a model, it creates a database migration. If you run 'destroy' on that model, it will delete the migration file, but not the database table. So before run

bundle exec rake db:rollback

Converting data frame column from character to numeric

If we need only one column to be numeric

yyz$b <- as.numeric(as.character(yyz$b))

But, if all the columns needs to changed to numeric, use lapply to loop over the columns and convert to numeric by first converting it to character class as the columns were factor.

yyz[] <- lapply(yyz, function(x) as.numeric(as.character(x)))

Both the columns in the OP's post are factor because of the string "n/a". This could be easily avoided while reading the file using na.strings = "n/a" in the read.table/read.csv or if we are using data.frame, we can have character columns with stringsAsFactors=FALSE (the default is stringsAsFactors=TRUE)


Regarding the usage of apply, it converts the dataset to matrix and matrix can hold only a single class. To check the class, we need

lapply(yyz, class)

Or

sapply(yyz, class)

Or check

str(yyz)

What difference between the DATE, TIME, DATETIME, and TIMESTAMP Types

DATE: It is used for values with a date part but no time part. MySQL retrieves and displays DATE values in YYYY-MM-DD format. The supported range is 1000-01-01 to 9999-12-31.

DATETIME: It is used for values that contain both date and time parts. MySQL retrieves and displays DATETIME values in YYYY-MM-DD HH:MM:SS format. The supported range is 1000-01-01 00:00:00 to 9999-12-31 23:59:59.

TIMESTAMP: It is also used for values that contain both date and time parts, and includes the time zone. TIMESTAMP has a range of 1970-01-01 00:00:01 UTC to 2038-01-19 03:14:07 UTC.

TIME: Its values are in HH:MM:SS format (or HHH:MM:SS format for large hours values). TIME values may range from -838:59:59 to 838:59:59. The hours part may be so large because the TIME type can be used not only to represent a time of day (which must be less than 24 hours), but also elapsed time or a time interval between two events (which may be much greater than 24 hours, or even negative).

Elegant way to check for missing packages and install them?

This solution will take a character vector of package names and attempt to load them, or install them if loading fails. It relies on the return behaviour of require to do this because...

require returns (invisibly) a logical indicating whether the required package is available

Therefore we can simply see if we were able to load the required package and if not, install it with dependencies. So given a character vector of packages you wish to load...

foo <- function(x){
  for( i in x ){
    #  require returns TRUE invisibly if it was able to load package
    if( ! require( i , character.only = TRUE ) ){
      #  If package was not able to be loaded then re-install
      install.packages( i , dependencies = TRUE )
      #  Load package after installing
      require( i , character.only = TRUE )
    }
  }
}

#  Then try/install packages...
foo( c("ggplot2" , "reshape2" , "data.table" ) )

Import Package Error - Cannot Convert between Unicode and Non Unicode String Data Type

The dts data Conversion task is time taking if there are 50 plus columns!Found a fix for this at the below link

http://rdc.codeplex.com/releases/view/48420

However, it does not seem to work for versions above 2008. So this is how i had to work around the problem

*Open the .DTSX file on Notepad++. Choose language as XML
*Goto the <DTS:FlatFileColumns> tag. Select all items within this tag
*Find the string **DTS:DataType="129"**  replace with **DTS:DataType="130"**
*Save the .DTSX file. 
*Open the project again on Visual Studio BIDS
*Double Click on the Source Task . You would get the message

the metadata of the following output columns does not match the metadata of the external columns with which the output columns are associated:
...
Do you want to replace the metadata of the output columns with the metadata of the external columns?

 *Now Click Yes. We are done !

How do I iterate over a range of numbers defined by variables in Bash?

Another layer of indirection:

for i in $(eval echo {1..$END}); do
    :

While loop to test if a file exists in bash

If you are on linux and have inotify-tools installed, you can do this:

file=/tmp/list.txt
while [ ! -f "$file" ]
do
    inotifywait -qqt 2 -e create -e moved_to "$(dirname $file)"
done

This reduces the delay introduced by sleep while still polling every "x" seconds. You can add more events if you anticipate that they are needed.

Set custom HTML5 required field validation message

HTML:

<form id="myform">
    <input id="email" oninvalid="InvalidMsg(this);" name="email" oninput="InvalidMsg(this);"  type="email" required="required" />
    <input type="submit" />
</form>

JAVASCRIPT :

function InvalidMsg(textbox) {
    if (textbox.value == '') {
        textbox.setCustomValidity('Required email address');
    }
    else if (textbox.validity.typeMismatch){{
        textbox.setCustomValidity('please enter a valid email address');
    }
    else {
       textbox.setCustomValidity('');
    }
    return true;
}

Demo :

http://jsfiddle.net/patelriki13/Sqq8e/

See what's in a stash without applying it

From the man git-stash page:

The modifications stashed away by this command can be listed with git stash list, inspected with git stash show

show [<stash>]
       Show the changes recorded in the stash as a diff between the stashed state and
       its original parent. When no <stash> is given, shows the latest one. By default,
       the command shows the diffstat, but it will accept any format known to git diff
       (e.g., git stash show -p stash@{1} to view the second most recent stash in patch
       form).

To list the stashed modifications

git stash list

To show files changed in the last stash

git stash show

So, to view the content of the most recent stash, run

git stash show -p

To view the content of an arbitrary stash, run something like

git stash show -p stash@{1}

Possible to extend types in Typescript?

What you are trying to achieve is equivalent to

interface Event {
   name: string;
   dateCreated: string;
   type: string;
}

interface UserEvent extends Event {
   UserId: string; 
}

The way you defined the types does not allow for specifying inheritance, however you can achieve something similar using intersection types, as artem pointed out.

Moving matplotlib legend outside of the axis makes it cutoff by the figure box

Added: I found something that should do the trick right away, but the rest of the code below also offers an alternative.

Use the subplots_adjust() function to move the bottom of the subplot up:

fig.subplots_adjust(bottom=0.2) # <-- Change the 0.02 to work for your plot.

Then play with the offset in the legend bbox_to_anchor part of the legend command, to get the legend box where you want it. Some combination of setting the figsize and using the subplots_adjust(bottom=...) should produce a quality plot for you.

Alternative: I simply changed the line:

fig = plt.figure(1)

to:

fig = plt.figure(num=1, figsize=(13, 13), dpi=80, facecolor='w', edgecolor='k')

and changed

lgd = ax.legend(loc=9, bbox_to_anchor=(0.5,0))

to

lgd = ax.legend(loc=9, bbox_to_anchor=(0.5,-0.02))

and it shows up fine on my screen (a 24-inch CRT monitor).

Here figsize=(M,N) sets the figure window to be M inches by N inches. Just play with this until it looks right for you. Convert it to a more scalable image format and use GIMP to edit if necessary, or just crop with the LaTeX viewport option when including graphics.

What is the use of ByteBuffer in Java?

Java IO using stream oriented APIs is performed using a buffer as temporary storage of data within user space. Data read from disk by DMA is first copied to buffers in kernel space, which is then transfer to buffer in user space. Hence there is overhead. Avoiding it can achieve considerable gain in performance.

We could skip this temporary buffer in user space, if there was a way directly to access the buffer in kernel space. Java NIO provides a way to do so.

ByteBuffer is among several buffers provided by Java NIO. Its just a container or holding tank to read data from or write data to. Above behavior is achieved by allocating a direct buffer using allocateDirect() API on Buffer.

Java Documentation of Byte Buffer has useful information.

Convert string to date in Swift

Hi You have separate T Format and then convert as you like

// create dateFormatter with UTC time format
let dateFormatter = NSDateFormatter()
dateFormatter.dateFormat = "yyyy-MM-dd'T'HH:mm:ss"
dateFormatter.timeZone = NSTimeZone(name: "UTC")
let date = dateFormatter.dateFromString("2015-04-01T11:42:00")

// change to a readable time format and change to local time zone
dateFormatter.dateFormat = "EEE, MMM d, yyyy - h:mm a"
dateFormatter.timeZone = NSTimeZone.localTimeZone() 
let timeStamp = dateFormatter.stringFromDate(date!)

hibernate: LazyInitializationException: could not initialize proxy

I think Piko means in his response that there is the hbm file. I have a file called Tax.java. The mapping information are saved in the hbm (=hibernate mapping) file. In the class tag there is a property called lazy. Set that property to true. The following hbm example shows a way to set the lazy property to false.

` id ...'

If you are using Annotations instead look in the hibernate documenation. http://docs.jboss.org/hibernate/stable/annotations/reference/en/html_single/

I hope that helped.

Begin, Rescue and Ensure in Ruby?

Yes, ensure ensures that the code is always evaluated. That's why it's called ensure. So, it is equivalent to Java's and C#'s finally.

The general flow of begin/rescue/else/ensure/end looks like this:

begin
  # something which might raise an exception
rescue SomeExceptionClass => some_variable
  # code that deals with some exception
rescue SomeOtherException => some_other_variable
  # code that deals with some other exception
else
  # code that runs only if *no* exception was raised
ensure
  # ensure that this code always runs, no matter what
  # does not change the final value of the block
end

You can leave out rescue, ensure or else. You can also leave out the variables in which case you won't be able to inspect the exception in your exception handling code. (Well, you can always use the global exception variable to access the last exception that was raised, but that's a little bit hacky.) And you can leave out the exception class, in which case all exceptions that inherit from StandardError will be caught. (Please note that this does not mean that all exceptions are caught, because there are exceptions which are instances of Exception but not StandardError. Mostly very severe exceptions that compromise the integrity of the program such as SystemStackError, NoMemoryError, SecurityError, NotImplementedError, LoadError, SyntaxError, ScriptError, Interrupt, SignalException or SystemExit.)

Some blocks form implicit exception blocks. For example, method definitions are implicitly also exception blocks, so instead of writing

def foo
  begin
    # ...
  rescue
    # ...
  end
end

you write just

def foo
  # ...
rescue
  # ...
end

or

def foo
  # ...
ensure
  # ...
end

The same applies to class definitions and module definitions.

However, in the specific case you are asking about, there is actually a much better idiom. In general, when you work with some resource which you need to clean up at the end, you do that by passing a block to a method which does all the cleanup for you. It's similar to a using block in C#, except that Ruby is actually powerful enough that you don't have to wait for the high priests of Microsoft to come down from the mountain and graciously change their compiler for you. In Ruby, you can just implement it yourself:

# This is what you want to do:
File.open('myFile.txt', 'w') do |file|
  file.puts content
end

# And this is how you might implement it:
def File.open(filename, mode='r', perm=nil, opt=nil)
  yield filehandle = new(filename, mode, perm, opt)
ensure
  filehandle&.close
end

And what do you know: this is already available in the core library as File.open. But it is a general pattern that you can use in your own code as well, for implementing any kind of resource cleanup (à la using in C#) or transactions or whatever else you might think of.

The only case where this doesn't work, if acquiring and releasing the resource are distributed over different parts of the program. But if it is localized, as in your example, then you can easily use these resource blocks.


BTW: in modern C#, using is actually superfluous, because you can implement Ruby-style resource blocks yourself:

class File
{
    static T open<T>(string filename, string mode, Func<File, T> block)
    {
        var handle = new File(filename, mode);
        try
        {
            return block(handle);
        }
        finally
        {
            handle.Dispose();
        }
    }
}

// Usage:

File.open("myFile.txt", "w", (file) =>
{
    file.WriteLine(contents);
});

How to read data from a zip file without having to unzip the entire file

DotNetZip is your friend here.

As easy as:

using (ZipFile zip = ZipFile.Read(ExistingZipFile))
{
  ZipEntry e = zip["MyReport.doc"];
  e.Extract(OutputStream);
}

(you can also extract to a file or other destinations).

Reading the zip file's table of contents is as easy as:

using (ZipFile zip = ZipFile.Read(ExistingZipFile))
{
  foreach (ZipEntry e in zip)
  {
    if (header)
    {
      System.Console.WriteLine("Zipfile: {0}", zip.Name);
      if ((zip.Comment != null) && (zip.Comment != "")) 
        System.Console.WriteLine("Comment: {0}", zip.Comment);
      System.Console.WriteLine("\n{1,-22} {2,8}  {3,5}   {4,8}  {5,3} {0}",
                               "Filename", "Modified", "Size", "Ratio", "Packed", "pw?");
      System.Console.WriteLine(new System.String('-', 72));
      header = false;
    }
    System.Console.WriteLine("{1,-22} {2,8} {3,5:F0}%   {4,8}  {5,3} {0}",
                             e.FileName,
                             e.LastModified.ToString("yyyy-MM-dd HH:mm:ss"),
                             e.UncompressedSize,
                             e.CompressionRatio,
                             e.CompressedSize,
                             (e.UsesEncryption) ? "Y" : "N");

  }
}

Edited To Note: DotNetZip used to live at Codeplex. Codeplex has been shut down. The old archive is still available at Codeplex. It looks like the code has migrated to Github:


How do I find the index of a character within a string in C?

This should do it:

//Returns the index of the first occurence of char c in char* string. If not found -1 is returned.
int get_index(char* string, char c) {
    char *e = strchr(string, c);
    if (e == NULL) {
        return -1;
    }
    return (int)(e - string);
}

jQuery ui datepicker with Angularjs

myModule.directive('jqdatepicker', function () {
    return {
        restrict: 'A',
        require: 'ngModel',
         link: function (scope, element, attrs, ngModelCtrl) {
            element.datepicker({
                dateFormat: 'dd/mm/yy',
                onSelect: function (date) {   
                    var ar=date.split("/");
                    date=new Date(ar[2]+"-"+ar[1]+"-"+ar[0]);
                    ngModelCtrl.$setViewValue(date.getTime());
                //    scope.course.launchDate = date;
                    scope.$apply();
                }
            });

        }
    };
});

HTML Code :

<input type="text" jqdatepicker  ng-model="course.launchDate" required readonly />

Create array of regex matches

Java makes regex too complicated and it does not follow the perl-style. Take a look at MentaRegex to see how you can accomplish that in a single line of Java code:

String[] matches = match("aa11bb22", "/(\\d+)/g" ); // => ["11", "22"]

How can I see the size of files and directories in linux?

ls -sh video.mp4 | sed s/video.mp4//g

output, 5.6M

Using only CSS, show div on hover over <a>

The + allow 'select' only first not nested element , the > select nested elements only - the better is to use ~ which allow to select arbitrary element which is child of parent hovered element. Using opacity/width and transition you can provide smooth appear

_x000D_
_x000D_
div { transition: all 1s }_x000D_
.ccc, .ggg { opacity: 0; color: red}_x000D_
.ccc { height: 0 }_x000D_
_x000D_
.aaa:hover ~ .bbb .ccc { opacity: 1; height: 34px }_x000D_
.aaa:hover ~ .eee .fff .ggg { opacity: 1 }
_x000D_
<div class="aaa">Hover me... to see<br><br> </div>_x000D_
_x000D_
<div class='bbb'>BBBBB_x000D_
  <div class='ccc'>CCCCC_x000D_
    <div class='ddd'>DDDDD</div>_x000D_
  </div>_x000D_
</div>_x000D_
_x000D_
<div class='eee'>EEEEE_x000D_
  <div class='fff'>FFFFF_x000D_
    <div class='ggg'>GGGGG</div>_x000D_
    <div class='hhh'>HHHHH</div>_x000D_
  </div>_x000D_
</div>
_x000D_
_x000D_
_x000D_

Java FileReader encoding issue

FileReader uses Java's platform default encoding, which depends on the system settings of the computer it's running on and is generally the most popular encoding among users in that locale.

If this "best guess" is not correct then you have to specify the encoding explicitly. Unfortunately, FileReader does not allow this (major oversight in the API). Instead, you have to use new InputStreamReader(new FileInputStream(filePath), encoding) and ideally get the encoding from metadata about the file.

How to open a new file in vim in a new window

I use this subtle alias:

alias vim='gnome-terminal -- vim'

-x is deprecated now. We need to use -- instead

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

are you running the example from the node_modules folder?

They are not supposed to be ran from there.

Create the following file on your project instead:

post-data.js

var Curl = require( 'node-libcurl' ).Curl,
   querystring = require( 'querystring' );

var curl = new Curl(),
  url  = 'http://posttestserver.com/post.php',
data = { //Data to send, inputName : value
    'input-arr[0]' : 'input-arr-val0',
    'input-arr[1]' : 'input-arr-val1',
    'input-arr[2]' : 'input-arr-val2',
    'input-name' : 'input-val'
};

//You need to build the query string, 
// node has this helper function, but it's limited for real use cases (no support for 
array values for example)
data = querystring.stringify( data );

 curl.setOpt( Curl.option.URL, url );
 curl.setOpt( Curl.option.POSTFIELDS, data );
 curl.setOpt( Curl.option.HTTPHEADER, ['User-Agent: node-libcurl/1.0'] );
 curl.setOpt( Curl.option.VERBOSE, true );

 console.log( querystring.stringify( data ) );

 curl.perform();

 curl.on( 'end', function( statusCode, body ) {

console.log( body );

this.close();
});

curl.on( 'error', curl.close.bind( curl ) );

Run with node post-data.js

ref:https://github.com/JCMais/node-libcurl/issues/98

Java Spring - How to use classpath to specify a file location?

Are we talking about standard java.io.FileReader? Won't work, but it's not hard without it.

/src/main/resources maven directory contents are placed in the root of your CLASSPATH, so you can simply retrieve it using:

InputStream is = getClass().getResourceAsStream("/storedProcedures.sql");

If the result is not null (resource not found), feel free to wrap it in a reader:

Reader reader = new InputStreamReader(is);

Using a cursor with dynamic SQL in a stored procedure

This code is a very good example for a dynamic column with a cursor, since you cannot use '+' in @STATEMENT:

ALTER PROCEDURE dbo.spTEST
AS
    SET NOCOUNT ON
    DECLARE @query NVARCHAR(4000) = N'' --DATA FILTER
    DECLARE @inputList NVARCHAR(4000) = ''
    DECLARE @field sysname = '' --COLUMN NAME
    DECLARE @my_cur CURSOR
    EXECUTE SP_EXECUTESQL
        N'SET @my_cur = CURSOR FAST_FORWARD FOR
            SELECT
                CASE @field
                    WHEN ''fn'' then fn
                    WHEN ''n_family_name'' then n_family_name
                END
            FROM
                dbo.vCard
            WHERE
                CASE @field
                    WHEN ''fn'' then fn
                    WHEN ''n_family_name'' then n_family_name
                END
                LIKE ''%''+@query+''%'';
            OPEN @my_cur;',
        N'@field sysname, @query NVARCHAR(4000), @my_cur CURSOR OUTPUT',
        @field = @field,
        @query = @query,
        @my_cur = @my_cur OUTPUT
    FETCH NEXT FROM @my_cur INTO @inputList
    WHILE @@FETCH_STATUS = 0
    BEGIN
        PRINT @inputList
        FETCH NEXT FROM @my_cur INTO @inputList
    END
    RETURN

"Continue" (to next iteration) on VBScript

We can use a separate function for performing a continue statement work. suppose you have following problem:

for i=1 to 10

if(condition) then   'for loop body'
contionue
End If

Next

Here we will use a function call for for loop body:

for i=1 to 10
Call loopbody()
next

function loopbody()

if(condition) then   'for loop body'
Exit Function
End If

End Function

loop will continue for function exit statement....

Simple 3x3 matrix inverse code (C++)

I went ahead and wrote it in python since I think it's a lot more readable than in c++ for a problem like this. The function order is in order of operations for solving this by hand via this video. Just import this and call "print_invert" on your matrix.

def print_invert (matrix):
  i_matrix = invert_matrix (matrix)
  for line in i_matrix:
    print (line)
  return

def invert_matrix (matrix):
  determinant = str (determinant_of_3x3 (matrix))
  cofactor = make_cofactor (matrix)
  trans_matrix = transpose_cofactor (cofactor)

  trans_matrix[:] = [[str (element) +'/'+ determinant for element in row] for row in trans_matrix]

  return trans_matrix

def determinant_of_3x3 (matrix):
  multiplication = 1
  neg_multiplication = 1
  total = 0
  for start_column in range (3):
    for row in range (3):
      multiplication *= matrix[row][(start_column+row)%3]
      neg_multiplication *= matrix[row][(start_column-row)%3]
    total += multiplication - neg_multiplication
    multiplication = neg_multiplication = 1
  if total == 0:
    total = 1
  return total

def make_cofactor (matrix):
  cofactor = [[0,0,0],[0,0,0],[0,0,0]]
  matrix_2x2 = [[0,0],[0,0]]
  # For each element in matrix...
  for row in range (3):
    for column in range (3):

      # ...make the 2x2 matrix in this inner loop
      matrix_2x2 = make_2x2_from_spot_in_3x3 (row, column, matrix)
      cofactor[row][column] = determinant_of_2x2 (matrix_2x2)

  return flip_signs (cofactor)

def make_2x2_from_spot_in_3x3 (row, column, matrix):
  c_count = 0
  r_count = 0
  matrix_2x2 = [[0,0],[0,0]]
  # ...make the 2x2 matrix in this inner loop
  for inner_row in range (3):
    for inner_column in range (3):
      if row is not inner_row and inner_column is not column:
        matrix_2x2[r_count % 2][c_count % 2] = matrix[inner_row][inner_column]
        c_count += 1
    if row is not inner_row:
      r_count += 1
  return matrix_2x2

def determinant_of_2x2 (matrix):
  total = matrix[0][0] * matrix [1][1]
  return total - (matrix [1][0] * matrix [0][1])

def flip_signs (cofactor):
  sign_pos = True 
  # For each element in matrix...
  for row in range (3):
    for column in range (3):
      if sign_pos:
        sign_pos = False
      else:
        cofactor[row][column] *= -1
        sign_pos = True
  return cofactor

def transpose_cofactor (cofactor):
  new_cofactor = [[0,0,0],[0,0,0],[0,0,0]]
  for row in range (3):
    for column in range (3):
      new_cofactor[column][row] = cofactor[row][column]
  return new_cofactor

How to enter ssh password using bash?

Create a new keypair: (go with the defaults)

ssh-keygen

Copy the public key to the server: (password for the last time)

ssh-copy-id [email protected]

From now on the server should recognize your key and not ask you for the password anymore:

ssh [email protected]

Difference between Divide and Conquer Algo and Dynamic Programming

Divide and Conquer

Divide and Conquer works by dividing the problem into sub-problems, conquer each sub-problem recursively and combine these solutions.

Dynamic Programming

Dynamic Programming is a technique for solving problems with overlapping subproblems. Each sub-problem is solved only once and the result of each sub-problem is stored in a table ( generally implemented as an array or a hash table) for future references. These sub-solutions may be used to obtain the original solution and the technique of storing the sub-problem solutions is known as memoization.

You may think of DP = recursion + re-use

A classic example to understand the difference would be to see both these approaches towards obtaining the nth fibonacci number. Check this material from MIT.


Divide and Conquer approach Divide and Conquer approach

Dynamic Programming Approach enter image description here

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

Check the generated code at MyAreaAreaRegistration.cs and make sure that the controller parameter is set to your default controller, otherwise the controller will be called bot for some reason ASP.NET MVC won't search for the views at the area folder

public override void RegisterArea(AreaRegistrationContext context)
    {
        context.MapRoute(
            "SomeArea_default",
            "SomeArea/{controller}/{action}/{id}",
            new { controller = "SomeController", action = "Index", id = UrlParameter.Optional }
        );
    }

Required maven dependencies for Apache POI to work

If you are not using maven, then you will need **

  • poi
  • poi-ooxml
  • xmlbeans
  • dom4j
  • poi-ooxml-schemas
  • stax-api
  • ooxml-schemas

Convert Enumeration to a Set/List

There is a simple example of convert enumeration to list. for this i used Collections.list(enum) method.

public class EnumerationToList {

    public static void main(String[] args) {
        Vector<String> vt = new Vector<String>();
        vt.add("java");
        vt.add("php");
        vt.add("array");
        vt.add("string");
        vt.add("c");

        Enumeration<String> enm = vt.elements();
        List<String> ll = Collections.list(enm);
        System.out.println("List elements: " + ll);
    }

}

Reference : How to convert enumeration to list

Use multiple custom fonts using @font-face?

You can use multiple font faces quite easily. Below is an example of how I used it in the past:

<!--[if (IE)]><!-->
    <style type="text/css" media="screen">
        @font-face {
            font-family: "Century Schoolbook";
            src: url(/fonts/century-schoolbook.eot);
        }
        @font-face {
            font-family: "Chalkduster";
            src: url(/fonts/chalkduster.eot);
        }
    </style>
<!--<![endif]-->
<!--[if !(IE)]><!-->
    <style type="text/css" media="screen">
        @font-face {
            font-family: "Century Schoolbook";
            src: url(/fonts/century-schoolbook.ttf);
        }
        @font-face {
            font-family: "Chalkduster";
            src: url(/fonts/chalkduster.ttf);
        }
    </style>
<!--<![endif]-->

It is worth noting that fonts can be funny across different Browsers. Font face on earlier browsers works, but you need to use eot files instead of ttf.

That is why I include my fonts in the head of the html file as I can then use conditional IE tags to use eot or ttf files accordingly.

If you need to convert ttf to eot for this purpose there is a brilliant website you can do this for free online, which can be found at http://ttf2eot.sebastiankippe.com/.

Hope that helps.

How to close a window using jQuery

This will only work for windows which are opened by using window.open(); method. Try this

var tmp=window.open(params);
tmp.close();

SSL Error: CERT_UNTRUSTED while using npm command

Reinstall node, then update npm.

First I removed node

apt-get purge node

Then install node according to the distibution. Docs here .

Then

npm install npm@latest -g

Sort an ArrayList based on an object field

Modify the DataNode class so that it implements Comparable interface.

public int compareTo(DataNode o)
{
     return(degree - o.degree);
}

then just use

Collections.sort(nodeList);

Oracle to_date, from mm/dd/yyyy to dd-mm-yyyy

select to_char(to_date('1/21/2000','mm/dd/yyyy'),'dd-mm-yyyy') from dual

How to position the form in the center screen?

Change this:

public FrameForm() { 
    initComponents(); 
}

to this:

public FrameForm() {
    initComponents();
    this.setLocationRelativeTo(null);
}

How to Create Multiple Where Clause Query Using Laravel Eloquent?

The whereColumn method can be passed an array of multiple conditions. These conditions will be joined using the and operator.

Example:

$users = DB::table('users')
            ->whereColumn([
                ['first_name', '=', 'last_name'],
                ['updated_at', '>', 'created_at']
            ])->get();

$users = User::whereColumn([
                ['first_name', '=', 'last_name'],
                ['updated_at', '>', 'created_at']
            ])->get();

For more information check this section of the documentation https://laravel.com/docs/5.4/queries#where-clauses

NameError: name 'python' is not defined

It looks like you are trying to start the Python interpreter by running the command python.

However the interpreter is already started. It is interpreting python as a name of a variable, and that name is not defined.

Try this instead and you should hopefully see that your Python installation is working as expected:

print("Hello world!")

"A namespace cannot directly contain members such as fields or methods"

The snippet you're showing doesn't seem to be directly responsible for the error.

This is how you can CAUSE the error:

namespace MyNameSpace
{
   int i; <-- THIS NEEDS TO BE INSIDE THE CLASS

   class MyClass
   {
      ...
   }
}

If you don't immediately see what is "outside" the class, this may be due to misplaced or extra closing bracket(s) }.

How do I print colored output with Python 3?

Since Python is interpreted and run in C, it is possible to set colors without a module.

You can define a class for colors like this:

class color:
   PURPLE = '\033[1;35;48m'
   CYAN = '\033[1;36;48m'
   BOLD = '\033[1;37;48m'
   BLUE = '\033[1;34;48m'
   GREEN = '\033[1;32;48m'
   YELLOW = '\033[1;33;48m'
   RED = '\033[1;31;48m'
   BLACK = '\033[1;30;48m'
   UNDERLINE = '\033[4;37;48m'
   END = '\033[1;37;0m'

When writing code, you can simply write:

print(color.BLUE + "hello friends" + color.END)

Note that the color you choose will have to be capitalized like your class definition, and that these are color choices that I personally find satisfying. For a fuller array of color choices and, indeed, background choices as well, please see: https://gist.github.com/RabaDabaDoba/145049536f815903c79944599c6f952a.

This is code for C, but can easily be adapted to Python once you realize how the code is written.

Take BLUE for example, since that is what you are wanting to display.

BLUE = '033[1;37;48m'

\033 tells Python to break and pay attention to the following formatting.

1 informs the code to be bold. (I prefer 1 to 0 because it pops more.)

34 is the actual color code. It chooses blue.

48m is the background color. 48m is the same shade as the console window, so it seems there is no background.

Codeigniter : calling a method of one controller from other

I agree that the way to do is to redirect to the new controller in usual cases.

I came across a use case where I needed to display the same page to 2 different kind of users (backend user previewing the page of a frontend user) so in my opinion what I needed was genuinely to call the frontend controller from the backend controller.

I solved the problem by making the frontend method static and wrapping it in another method. Hope it helps!

//==========
// Frontend
//==========
function profile()
{
   //Access check

   //Get profile id
   $id = get_user_id();

   return self::_profile($id);
}

static function _profile($id)
{
   $CI = &get_instance();
   //Prepare page
   //Load view
}

//==========
// Backend
//==========
function preview_profile($id)
{
   $this->load->file('controllers/frontend.php', false);

   Frontend::_profile($id);
}

How to get HttpContext.Current in ASP.NET Core?

Necromancing.
YES YOU CAN, and this is how.
A secret tip for those migrating large junks chunks of code:
The following method is an evil carbuncle of a hack which is actively engaged in carrying out the express work of satan (in the eyes of .NET Core framework developers), but it works:

In public class Startup

add a property

public IConfigurationRoot Configuration { get; }

And then add a singleton IHttpContextAccessor to DI in ConfigureServices.

    // This method gets called by the runtime. Use this method to add services to the container.
    public void ConfigureServices(IServiceCollection services)
    {
        services.AddSingleton<Microsoft.AspNetCore.Http.IHttpContextAccessor, Microsoft.AspNetCore.Http.HttpContextAccessor>();

Then in Configure

    public void Configure(
              IApplicationBuilder app
             ,IHostingEnvironment env
             ,ILoggerFactory loggerFactory
    )
    {

add the DI Parameter IServiceProvider svp, so the method looks like:

    public void Configure(
           IApplicationBuilder app
          ,IHostingEnvironment env
          ,ILoggerFactory loggerFactory
          ,IServiceProvider svp)
    {

Next, create a replacement class for System.Web:

namespace System.Web
{

    namespace Hosting
    {
        public static class HostingEnvironment 
        {
            public static bool m_IsHosted;

            static HostingEnvironment()
            {
                m_IsHosted = false;
            }

            public static bool IsHosted
            {
                get
                {
                    return m_IsHosted;
                }
            }
        }
    }


    public static class HttpContext
    {
        public static IServiceProvider ServiceProvider;

        static HttpContext()
        { }


        public static Microsoft.AspNetCore.Http.HttpContext Current
        {
            get
            {
                // var factory2 = ServiceProvider.GetService<Microsoft.AspNetCore.Http.IHttpContextAccessor>();
                object factory = ServiceProvider.GetService(typeof(Microsoft.AspNetCore.Http.IHttpContextAccessor));

                // Microsoft.AspNetCore.Http.HttpContextAccessor fac =(Microsoft.AspNetCore.Http.HttpContextAccessor)factory;
                Microsoft.AspNetCore.Http.HttpContext context = ((Microsoft.AspNetCore.Http.HttpContextAccessor)factory).HttpContext;
                // context.Response.WriteAsync("Test");

                return context;
            }
        }


    } // End Class HttpContext 


}

Now in Configure, where you added the IServiceProvider svp, save this service provider into the static variable "ServiceProvider" in the just created dummy class System.Web.HttpContext (System.Web.HttpContext.ServiceProvider)

and set HostingEnvironment.IsHosted to true

System.Web.Hosting.HostingEnvironment.m_IsHosted = true;

this is essentially what System.Web did, just that you never saw it (I guess the variable was declared as internal instead of public).

// This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
public void Configure(IApplicationBuilder app, IHostingEnvironment env, ILoggerFactory loggerFactory, IServiceProvider svp)
{
    loggerFactory.AddConsole(Configuration.GetSection("Logging"));
    loggerFactory.AddDebug();

    ServiceProvider = svp;
    System.Web.HttpContext.ServiceProvider = svp;
    System.Web.Hosting.HostingEnvironment.m_IsHosted = true;


    app.UseCookieAuthentication(new CookieAuthenticationOptions()
    {
        AuthenticationScheme = "MyCookieMiddlewareInstance",
        LoginPath = new Microsoft.AspNetCore.Http.PathString("/Account/Unauthorized/"),
        AccessDeniedPath = new Microsoft.AspNetCore.Http.PathString("/Account/Forbidden/"),
        AutomaticAuthenticate = true,
        AutomaticChallenge = true,
        CookieSecure = Microsoft.AspNetCore.Http.CookieSecurePolicy.SameAsRequest

       , CookieHttpOnly=false

    });

Like in ASP.NET Web-Forms, you'll get a NullReference when you're trying to access a HttpContext when there is none, such as it used to be in Application_Start in global.asax.

I stress again, this only works if you actually added

services.AddSingleton<Microsoft.AspNetCore.Http.IHttpContextAccessor, Microsoft.AspNetCore.Http.HttpContextAccessor>();

like I wrote you should.
Welcome to the ServiceLocator pattern within the DI pattern ;)
For risks and side effects, ask your resident doctor or pharmacist - or study the sources of .NET Core at github.com/aspnet, and do some testing.


Perhaps a more maintainable method would be adding this helper class

namespace System.Web
{

    public static class HttpContext
    {
        private static Microsoft.AspNetCore.Http.IHttpContextAccessor m_httpContextAccessor;


        public static void Configure(Microsoft.AspNetCore.Http.IHttpContextAccessor httpContextAccessor)
        {
            m_httpContextAccessor = httpContextAccessor;
        }


        public static Microsoft.AspNetCore.Http.HttpContext Current
        {
            get
            {
                return m_httpContextAccessor.HttpContext;
            }
        }


    }


}

And then calling HttpContext.Configure in Startup->Configure

public void Configure(IApplicationBuilder app, IHostingEnvironment env, ILoggerFactory loggerFactory, IServiceProvider svp)
{
    loggerFactory.AddConsole(Configuration.GetSection("Logging"));
    loggerFactory.AddDebug();


    System.Web.HttpContext.Configure(app.ApplicationServices.
        GetRequiredService<Microsoft.AspNetCore.Http.IHttpContextAccessor>()
    );

ssh server connect to host xxx port 22: Connection timed out on linux-ubuntu

Try connecting to a vpn, if possible. That was the reason I was facing problem. Tip: if you're using an ec2 machine, try rebooting it. This worked for me the other day :)

Storing Python dictionaries

Pickle save:

try:
    import cPickle as pickle
except ImportError:  # Python 3.x
    import pickle

with open('data.p', 'wb') as fp:
    pickle.dump(data, fp, protocol=pickle.HIGHEST_PROTOCOL)

See the pickle module documentation for additional information regarding the protocol argument.

Pickle load:

with open('data.p', 'rb') as fp:
    data = pickle.load(fp)

JSON save:

import json

with open('data.json', 'w') as fp:
    json.dump(data, fp)

Supply extra arguments, like sort_keys or indent, to get a pretty result. The argument sort_keys will sort the keys alphabetically and indent will indent your data structure with indent=N spaces.

json.dump(data, fp, sort_keys=True, indent=4)

JSON load:

with open('data.json', 'r') as fp:
    data = json.load(fp)

Which data type for latitude and longitude?

I strongly advocate for PostGis. It's specific for that kind of datatype and it has out of the box methods to calculate distance between points, among other GIS operations that you can find useful in the future

Limit Get-ChildItem recursion depth

Use this to limit the depth to 2:

Get-ChildItem \*\*\*,\*\*,\*

The way it works is that it returns the children at each depth 2,1 and 0.


Explanation:

This command

Get-ChildItem \*\*\*

returns all items with a depth of two subfolders. Adding \* adds an additional subfolder to search in.

In line with the OP question, to limit a recursive search using get-childitem you are required to specify all the depths that can be searched.

Binding a generic list to a repeater - ASP.NET

Code Behind:

public class Friends
{
    public string   ID      { get; set; }
    public string   Name    { get; set; }
    public string   Image   { get; set; }
}

protected void Page_Load(object sender, EventArgs e)
{
        List <Friends> friendsList = new List<Friends>();

        foreach (var friend  in friendz)
        {
            friendsList.Add(
                new Friends { ID = friend.id, Name = friend.name }    
            );

        }

        this.rptFriends.DataSource = friendsList;
        this.rptFriends.DataBind();
}

.aspx Page

<asp:Repeater ID="rptFriends" runat="server">
            <HeaderTemplate>
                <table border="0" cellpadding="0" cellspacing="0">
                    <thead>
                        <tr>
                            <th>ID</th>
                            <th>Name</th>
                        </tr>
                    </thead>
                    <tbody>
            </HeaderTemplate>
            <ItemTemplate>
                    <tr>
                        <td><%# Eval("ID") %></td>
                        <td><%# Eval("Name") %></td>
                    </tr>
            </ItemTemplate>
            <FooterTemplate>
                    </tbody>
                </table>
            </FooterTemplate>
        </asp:Repeater>

How can I initialize an array without knowing it size?

Just return any kind of list. ArrayList will be fine, its not static.

    ArrayList<yourClass> list = new ArrayList<yourClass>();
for (yourClass item : yourArray) 
{
   list.add(item); 
}

z-index not working with position absolute

I faced this issue a lot when using position: absolute;, I faced this issue by using position: relative in the child element. don't need to change position: absolute to relative, just need to add in the child element look into the beneath two examples:

_x000D_
_x000D_
let toggle = document.getElementById('toggle')

toggle.addEventListener("click", () => {
 toggle.classList.toggle('change');
})
_x000D_
.container {
  width: 60px;
  height: 22px;
  background: #333;
  border-radius: 20px;
  position: relative;
  cursor: pointer;

}

.change .slide {
  transform: translateX(33px);
}

.slide {
  transition: 0.5s;
  width: 20px;
  height: 20px;
  background: #fff;
  border-radius: 20px;
  margin: 2px 2px;
  z-index: 100;
}

.dot {
  width: 10px;
  height: 16px;
  background: red;
  position: absolute;
  top: 4px;
  right: 5px;
  z-index: 1;
}
_x000D_
<div class="container" id="toggle">
  <div class="slide"></div>
  <div class="dot"></div>
</div>
_x000D_
_x000D_
_x000D_

This's how it can be fixed using position relative:

_x000D_
_x000D_
let toggle = document.getElementById('toggle')

toggle.addEventListener("click", () => {
 toggle.classList.toggle('change');
})
_x000D_
.container {
  width: 60px;
  height: 22px;
  background: #333;
  border-radius: 20px;
  position: relative;
  cursor: pointer;

}

.change .slide {
  transform: translateX(33px);
}

.slide {
  transition: 0.5s;
  width: 20px;
  height: 20px;
  background: #fff;
  border-radius: 20px;
  margin: 2px 2px;
  z-index: 100;
  
  // Just add position relative;
  position: relative;
}

.dot {
  width: 10px;
  height: 16px;
  background: red;
  position: absolute;
  top: 4px;
  right: 5px;
  z-index: 1;
}
_x000D_
<div class="container" id="toggle">
  <div class="slide"></div>
  <div class="dot"></div>
</div>
_x000D_
_x000D_
_x000D_

Sandbox here

SQL: Alias Column Name for Use in CASE Statement

Not in MySQL. I tried it and I get the following error:

ERROR 1054 (42S22): Unknown column 'a' in 'field list'

Android Studio not showing modules in project structure

Do right mouse click on your project, then select 'Open Module Settings' - then you can add modules to your project..

How to POST using HTTPclient content type = application/x-www-form-urlencoded

I was using a .Net Core 2.1 API with the [FromBody] attribute and I had to use the following solution to successfully Post to it:

_apiClient =  new HttpClient();
_apiClient.BaseAddress = new Uri(<YOUR API>);
var MyObject myObject = new MyObject(){
    FirstName = "Me",
    LastName = "Myself"
};

var stringified = JsonConvert.SerializeObject(myObject);
var result = await _apiClient.PostAsync("api/appusers", new StringContent(stringified, Encoding.UTF8, "application/json"));

Array String Declaration

As Tr?n Si Long suggested, use

String[] mStrings = new String[title.length];

And replace string concatation with proper parenthesis.

mStrings[i] = (urlbase + (title[i].replaceAll("[^a-zA-Z]", ""))).toLowerCase() + imgSel;

Try this. If it's problem due to concatation, it will be resolved with proper brackets. Hope it helps.

Matplotlib: Specify format of floats for tick labels

The answer above is probably the correct way to do it, but didn't work for me.

The hacky way that solved it for me was the following:

ax = <whatever your plot is> 
# get the current labels 
labels = [item.get_text() for item in ax.get_xticklabels()]
# Beat them into submission and set them back again
ax.set_xticklabels([str(round(float(label), 2)) for label in labels])
# Show the plot, and go home to family 
plt.show()

How to lock orientation of one view controller to portrait mode only in Swift

Thanks to @bmjohn's answer above. Here is a working Xamarin / C# version of the that answer's code, to save others the time of transcription:

AppDelegate.cs

 public UIInterfaceOrientationMask OrientationLock = UIInterfaceOrientationMask.All;
 public override UIInterfaceOrientationMask GetSupportedInterfaceOrientations(UIApplication application, UIWindow forWindow)
 {
     return this.OrientationLock;
 }

Static OrientationUtility.cs class:

public static class OrientationUtility
{
    public static void LockOrientation(UIInterfaceOrientationMask orientation)
    {
        var appdelegate = (AppDelegate) UIApplication.SharedApplication.Delegate;
        if(appdelegate != null)
        {
            appdelegate.OrientationLock = orientation;
        }
    }

    public static void LockOrientation(UIInterfaceOrientationMask orientation, UIInterfaceOrientation RotateToOrientation)
    {
        LockOrientation(orientation);

        UIDevice.CurrentDevice.SetValueForKey(new NSNumber((int)RotateToOrientation), new NSString("orientation"));
    }
}

View Controller:

    public override void ViewDidAppear(bool animated)
    {
       base.ViewWillAppear(animated);
       OrientationUtility.LockOrientation(UIInterfaceOrientationMask.Portrait, UIInterfaceOrientation.Portrait);
    }

    public override void ViewWillDisappear(bool animated)
    {
        base.ViewWillDisappear(animated);
        OrientationUtility.LockOrientation(UIInterfaceOrientationMask.All);
    }

Perform Button click event when user press Enter key in Textbox

You can try:

In HTML:

    <asp:TextBox ID="TextBox1" runat="server" onKeyDown="submitButton(event)"></asp:TextBox>
<asp:Button ID="Button1" runat="server" Text="Button" onclick="Button1_Click" />

And javascript:

function submitButton(event) {
        if (event.which == 13) {
            $('#Button1').trigger('click');
        }
    }

Code behind:

protected void Button1_Click(object sender, EventArgs e)
{
        //load data and fill to gridview
} // fixed the function view for users

Hope this help

React JS Error: is not defined react/jsx-no-undef

This happens to me occasionally, usually it's just a simple oversight. Just pay attention to details, simple typos, etc. For example when copy/pasting import statements, like this: enter image description here

Aggregate a dataframe on a given column and display another column

This is how I baseically think of the problem.

my.df <- data.frame(group = rep(c(1,2), each = 3), 
        score = runif(6), info = letters[1:6])
my.agg <- with(my.df, aggregate(score, list(group), max))
my.df.split <- with(my.df, split(x = my.df, f = group))
my.agg$info <- unlist(lapply(my.df.split, FUN = function(x) {
            x[which(x$score == max(x$score)), "info"]
        }))

> my.agg
  Group.1         x info
1       1 0.9344336    a
2       2 0.7699763    e

Java: how to represent graphs?

class Graph<E> {
    private List<Vertex<E>> vertices;

    private static class Vertex<E> {
        E elem;
        List<Vertex<E>> neighbors;
    }
}

What is the main purpose of setTag() getTag() methods of View?

Setting of TAGs is really useful when you have a ListView and want to recycle/reuse the views. In that way the ListView is becoming very similar to the newer RecyclerView.

@Override
public View getView(int position, View convertView, ViewGroup parent)
  {
ViewHolder holder = null;

if ( convertView == null )
{
    /* There is no view at this position, we create a new one. 
       In this case by inflating an xml layout */
    convertView = mInflater.inflate(R.layout.listview_item, null);  
    holder = new ViewHolder();
    holder.toggleOk = (ToggleButton) convertView.findViewById( R.id.togOk );
    convertView.setTag (holder);
}
else
{
    /* We recycle a View that already exists */
    holder = (ViewHolder) convertView.getTag ();
}

// Once we have a reference to the View we are returning, we set its values.

// Here is where you should set the ToggleButton value for this item!!!

holder.toggleOk.setChecked( mToggles.get( position ) );

return convertView;
}

How to open VMDK File of the Google-Chrome-OS bundle 2012?

WinMount provides an easiest way to mount VMDK as a virtual disk. You can read or write to the vmdk file without loading the virtual system. Here shows you how to do: http://www.winmount.com/mount_vmdk.html

Perform Segue programmatically and pass parameters to the destination view

I understand the problem of performing the segue at one place and maintaining the state to send parameters in prepare for segue.

I figured out a way to do this. I've added a property called userInfoDict to ViewControllers using a category. and I've override perform segue with identifier too, in such a way that If the sender is self(means the controller itself). It will pass this userInfoDict to the next ViewController.

Here instead of passing the whole UserInfoDict you can also pass the specific params, as sender and override accordingly.

1 thing you need to keep in mind. don't forget to call super method in ur performSegue method.

How do I get the entity that represents the current user in Symfony2?

Best practice

According to the documentation since Symfony 2.1 simply use this shortcut :

$user = $this->getUser();

The above is still working on Symfony 3.2 and is a shortcut for this :

$user = $this->get('security.token_storage')->getToken()->getUser();

The security.token_storage service was introduced in Symfony 2.6. Prior to Symfony 2.6, you had to use the getToken() method of the security.context service.

Example : And if you want directly the username :

$username = $this->getUser()->getUsername();

If wrong user class type

The user will be an object and the class of that object will depend on your user provider.

Load external css file like scripts in jquery which is compatible in ie also

Based on your comment under @Raul's answer, I can think of two ways to include a callback:

  1. Have getScript call the file that loads the css.
  2. Load the contents of the css file with AJAX, and append to <style>. Your callback would be the callback from $.get or whatever you use to load the css file contents.

How to convert DateTime to VarChar

The shortest and the simplest way is :

DECLARE @now AS DATETIME = GETDATE()

SELECT CONVERT(VARCHAR, @now, 23)

How do I put double quotes in a string in vba?

I have written a small routine which copies formula from a cell to clipboard which one can easily paste in Visual Basic Editor.

    Public Sub CopyExcelFormulaInVBAFormat()
        Dim strFormula As String
        Dim objDataObj As Object

        '\Check that single cell is selected!
       If Selection.Cells.Count > 1 Then
            MsgBox "Select single cell only!", vbCritical
            Exit Sub
        End If

        'Check if we are not on a blank cell!
       If Len(ActiveCell.Formula) = 0 Then
            MsgBox "No Formula To Copy!", vbCritical
            Exit Sub
        End If

        'Add quotes as required in VBE
       strFormula = Chr(34) & Replace(ActiveCell.Formula, Chr(34), Chr(34) & Chr(34)) & Chr(34)

        'This is ClsID of MSFORMS Data Object
       Set objDataObj = CreateObject("New:{1C3B4210-F441-11CE-B9EA-00AA006B1A69}")
        objDataObj.SetText strFormula, 1
        objDataObj.PutInClipboard
        MsgBox "VBA Format formula copied to Clipboard!", vbInformation

        Set objDataObj = Nothing

    End Sub

It is originally posted on Chandoo.org forums' Vault Section.

Using app.config in .Net Core

I have a .Net Core 3.1 MSTest project with similar issue. This post provided clues to fix it.

Breaking this down to a simple answer for .Net core 3.1:

  • add/ensure nuget package: System.Configuration.ConfigurationManager to project
  • add your app.config(xml) to project.

If it is a MSTest project:

  • rename file in project to testhost.dll.config

    OR

  • Use post-build command provided by DeepSpace101

What is the Angular equivalent to an AngularJS $watch?

In Angular 2, change detection is automatic... $scope.$watch() and $scope.$digest() R.I.P.

Unfortunately, the Change Detection section of the dev guide is not written yet (there is a placeholder near the bottom of the Architecture Overview page, in section "The Other Stuff").

Here's my understanding of how change detection works:

  • Zone.js "monkey patches the world" -- it intercepts all of the asynchronous APIs in the browser (when Angular runs). This is why we can use setTimeout() inside our components rather than something like $timeout... because setTimeout() is monkey patched.
  • Angular builds and maintains a tree of "change detectors". There is one such change detector (class) per component/directive. (You can get access to this object by injecting ChangeDetectorRef.) These change detectors are created when Angular creates components. They keep track of the state of all of your bindings, for dirty checking. These are, in a sense, similar to the automatic $watches() that Angular 1 would set up for {{}} template bindings.
    Unlike Angular 1, the change detection graph is a directed tree and cannot have cycles (this makes Angular 2 much more performant, as we'll see below).
  • When an event fires (inside the Angular zone), the code we wrote (the event handler callback) runs. It can update whatever data it wants to -- the shared application model/state and/or the component's view state.
  • After that, because of the hooks Zone.js added, it then runs Angular's change detection algorithm. By default (i.e., if you are not using the onPush change detection strategy on any of your components), every component in the tree is examined once (TTL=1)... from the top, in depth-first order. (Well, if you're in dev mode, change detection runs twice (TTL=2). See ApplicationRef.tick() for more about this.) It performs dirty checking on all of your bindings, using those change detector objects.
    • Lifecycle hooks are called as part of change detection.
      If the component data you want to watch is a primitive input property (String, boolean, number), you can implement ngOnChanges() to be notified of changes.
      If the input property is a reference type (object, array, etc.), but the reference didn't change (e.g., you added an item to an existing array), you'll need to implement ngDoCheck() (see this SO answer for more on this).
      You should only change the component's properties and/or properties of descendant components (because of the single tree walk implementation -- i.e., unidirectional data flow). Here's a plunker that violates that. Stateful pipes can also trip you up here.
  • For any binding changes that are found, the Components are updated, and then the DOM is updated. Change detection is now finished.
  • The browser notices the DOM changes and updates the screen.

Other references to learn more:

Proper usage of Optional.ifPresent()

In addition to @JBNizet's answer, my general use case for ifPresent is to combine .isPresent() and .get():

Old way:

Optional opt = getIntOptional();
if(opt.isPresent()) {
    Integer value = opt.get();
    // do something with value
}

New way:

Optional opt = getIntOptional();
opt.ifPresent(value -> {
    // do something with value
})

This, to me, is more intuitive.

How do I exit a while loop in Java?

You can use "break", already mentioned in the answers above. If you need to return some values. You can use "return" like the code below:

 while(true){
       if(some condition){
            do something;
            return;}
        else{
            do something;
            return;}
            }

in this case, this while is in under a method which is returning some kind of values.

xxxxxx.exe is not a valid Win32 application

VS 2012 applications cannot be run under Windows XP.

See this VC++ blog on why and how to make it work.

It seems to be supported/possible from Feb 2013. See noelicus answer below on how to.

find difference between two text files with one item per line

I successfully used

diff "${file1}" "${file2}" | grep "<" | sed 's/^<//g' > "${diff_file}"

Outputting the difference to a file.

Background images: how to fill whole div if image is small and vice versa

Try below code segment, I've tried it myself before :

#your-div {
    background: url("your-image-link") no-repeat;
    background-size: cover;
    background-clip: border-box;
}

How to remove focus without setting focus to another control?

Try the following (calling clearAllEditTextFocuses();)

private final boolean clearAllEditTextFocuses() {
    View v = getCurrentFocus();
    if(v instanceof EditText) {
        final FocusedEditTextItems list = new FocusedEditTextItems();
        list.addAndClearFocus((EditText) v);

        //Focus von allen EditTexten entfernen
        boolean repeat = true;
        do {
            v = getCurrentFocus();
            if(v instanceof EditText) {
                if(list.containsView(v))
                    repeat = false;
                else list.addAndClearFocus((EditText) v);
            } else repeat = false;
        } while(repeat);

        final boolean result = !(v instanceof EditText);
        //Focus wieder setzen
        list.reset();
        return result;
    } else return false;
}

private final static class FocusedEditTextItem {

    private final boolean focusable;

    private final boolean focusableInTouchMode;

    @NonNull
    private final EditText editText;

    private FocusedEditTextItem(final @NonNull EditText v) {
        editText = v;
        focusable = v.isFocusable();
        focusableInTouchMode = v.isFocusableInTouchMode();
    }

    private final void clearFocus() {
        if(focusable)
            editText.setFocusable(false);
        if(focusableInTouchMode)
            editText.setFocusableInTouchMode(false);
        editText.clearFocus();
    }

    private final void reset() {
        if(focusable)
            editText.setFocusable(true);
        if(focusableInTouchMode)
            editText.setFocusableInTouchMode(true);
    }

}

private final static class FocusedEditTextItems extends ArrayList<FocusedEditTextItem> {

    private final void addAndClearFocus(final @NonNull EditText v) {
        final FocusedEditTextItem item = new FocusedEditTextItem(v);
        add(item);
        item.clearFocus();
    }

    private final boolean containsView(final @NonNull View v) {
        boolean result = false;
        for(FocusedEditTextItem item: this) {
            if(item.editText == v) {
                result = true;
                break;
            }
        }
        return result;
    }

    private final void reset() {
        for(FocusedEditTextItem item: this)
            item.reset();
    }

}

JDK on OSX 10.7 Lion

For Mountain Lion, Apple's java is up to 1.6.0_35-b10-428.jdk as of today.
It is indeed located under /Library/Java/JavaVirtualMachines .

You just download
"Java for OS X 2012-005 Developer Package" (Sept 6, 2012)
from
http://connect.apple.com/

In my view, Apple's naming is at least a bit confusing; why "-005" - is this the fifth version, or the fifth of five installers one needs?

And then run the installer; then follow the above steps inside Eclipse.

How do I display a MySQL error in PHP for a long query that depends on the user input?

Use this:

mysqli_query($this->db_link, $query) or die(mysqli_error($this->db_link)); 
# mysqli_query($link,$query) returns 0 if there's an error.
# mysqli_error($link) returns a string with the last error message

You can also use this to print the error code.

echo mysqli_errno($this->db_link);

Take a look here and here

Create database from command line

Change the user to postgres :

su - postgres

Create User for Postgres

$ createuser testuser

Create Database

$ createdb testdb

Acces the postgres Shell

psql ( enter the password for postgressql)

Provide the privileges to the postgres user

$ alter user testuser with encrypted password 'qwerty';
$ grant all privileges on database testdb to testuser;

Add default value of datetime field in SQL Server to a timestamp

To make it simpler to follow, I will summarize the above answers:

Let`s say the table is called Customer it has 4 columns/less or more...

you want to add a new column to the table where every time when there is insert... then that column keeps a record of the time the event happened.

Solution:

add a new column, let`s say timepurchase is the new column, to the table with data type datetime.

Then run the following alter:

ALTER TABLE Customer ADD CONSTRAINT DF_Customer DEFAULT GETDATE() FOR timePurchase

How to find the date of a day of the week from a date using PHP?

I had to use a similar solution for Portuguese (Brazil):

<?php
$scheduled_day = '2018-07-28';
$days = ['Dom','Seg','Ter','Qua','Qui','Sex','Sáb'];
$day = date('w',strtotime($scheduled_day));
$scheduled_day = date('d-m-Y', strtotime($scheduled_day))." ($days[$day])";
// provides 28-07-2018 (Sáb)

How can I pull from remote Git repository and override the changes in my local repository?

As an addendum, if you want to reapply your changes on top of the remote, you can also try:

git pull --rebase origin master

If you then want to undo some of your changes (but perhaps not all of them) you can use:

git reset SHA_HASH

Then do some adjustment and recommit.

Keeping session alive with Curl and PHP

You also need to set the option CURLOPT_COOKIEFILE.

The manual describes this as

The name of the file containing the cookie data. The cookie file can be in Netscape format, or just plain HTTP-style headers dumped into a file. If the name is an empty string, no cookies are loaded, but cookie handling is still enabled.

Since you are using the cookie jar you end up saving the cookies when the requests finish, but since the CURLOPT_COOKIEFILE is not given, cURL isn't sending any of the saved cookies on subsequent requests.

What does \d+ mean in regular expression terms?

\d is called a character class and will match digits. It is equal to [0-9].

+ matches 1 or more occurrences of the character before.

So \d+ means match 1 or more digits.

Fatal error: Out of memory, but I do have plenty of memory (PHP)

Fatal error: Out of memory (allocated SOLVED
i had similar problem, for months no solution. finally i was checking in one of the apache folders i.e(\apache\conf\extra) i came across this file that controls the memory allocation of apache. the file name is httpd-mpm in that file you are to increase the MaxMemFree which is set 2048 to something higher, i took mine to 10000 for the first MaxMemFree (IfModule !mpm_netware_module) then made the second one MaxMemFree to 5000 IfModule mpm_netware_module.

These solved my problem. hope it helps

Using Java generics for JPA findAll() query with WHERE clause

you can also use a namedQuery named findAll for all your entities and call it in your generic FindAll with

entityManager.createNamedQuery(persistentClass.getSimpleName()+"findAll").getResultList();

How to convert uint8 Array to base64 Encoded String?

function Uint8ToBase64(u8Arr){
  var CHUNK_SIZE = 0x8000; //arbitrary number
  var index = 0;
  var length = u8Arr.length;
  var result = '';
  var slice;
  while (index < length) {
    slice = u8Arr.subarray(index, Math.min(index + CHUNK_SIZE, length)); 
    result += String.fromCharCode.apply(null, slice);
    index += CHUNK_SIZE;
  }
  return btoa(result);
}

You can use this function if you have a very large Uint8Array. This is for Javascript, can be useful in case of FileReader readAsArrayBuffer.

Password must have at least one non-alpha character

Run it through a fairly simple regex: [^a-zA-Z]

And then check it's length separately:

if(string.Length > 7)

maven compilation failure

The error is pretty clear: "cannot find symbol". Some dependencies can't be resolved (you even have the line and column in the trace of the reference that can't be resolved):

V:/dhs_tss_build_view/dhs_tssproject/tss/tsscommon-server/src/main/java/us/mn/state/dhs/tss/common/oblix/da/wsdl/OblixLoginAc
cess.java:[51,60] cannot find symbol
symbol  : class BusinessException
location: class us.mn.state.dhs.tss.common.oblix.da.wsdl.OblixLoginAccess

V:/dhs_tss_build_view/dhs_tssproject/tss/tsscommon-server/src/main/java/us/mn/state/dhs/tss/common/app/da/ldap/BaseLdapImpl.j
ava:[187,14] cannot find symbol
symbol  : class Phone
location: class us.mn.state.dhs.tss.common.app.da.ldap.BaseLdapImpl

V:/dhs_tss_build_view/dhs_tssproject/tss/tsscommon-server/src/main/java/us/mn/state/dhs/tss/common/app/da/ldap/BaseLdapImpl.j
ava:[204,14] cannot find symbol
symbol  : class Phone
location: class us.mn.state.dhs.tss.common.app.da.ldap.BaseLdapImpl

Below a couple of things to verify:

  • Check or recheck that these classes are in the jar A (same version as in the pom)
  • Check or recheck the import statement in B sources (should match the package of classes in A)
  • Check or recheck B's pom.xml and especially the declaration of the dependency on A (it's version)
  • Check that the dependency on A is not excluded transitively somewhere in B's pom
  • Is A a SNAPSHOT dependency? If no, delete A from your local repository and rebuild

Maven is working fine, you have a mistake somewhere.

#ifdef replacement in the Swift language

Moignans answer here works fine. Here is another peace of info in case it helps,

#if DEBUG
    let a = 2
#else
    let a = 3
#endif

You can negate the macros like below,

#if !RELEASE
    let a = 2
#else
    let a = 3
#endif

How do I remove all HTML tags from a string without knowing which tags are in it?

You can use the below code on your string and you will get the complete string without html part.

string title = "<b> Hulk Hogan's Celebrity Championship Wrestling &nbsp;&nbsp;&nbsp;<font color=\"#228b22\">[Proj # 206010]</font></b>&nbsp;&nbsp;&nbsp; (Reality Series, &nbsp;)".Replace("&nbsp;",string.Empty);            
        string s = Regex.Replace(title, "<.*?>", String.Empty);

How to capture a backspace on the onkeydown event

Try this:

document.addEventListener("keydown", KeyCheck);  //or however you are calling your method
function KeyCheck(event)
{
   var KeyID = event.keyCode;
   switch(KeyID)
   {
      case 8:
      alert("backspace");
      break; 
      case 46:
      alert("delete");
      break;
      default:
      break;
   }
}

What is the $$hashKey added to my JSON.stringify result

If you are using Angular 1.3 or above, I recommend that you use "track by" in your ng-repeat. Angular doesn't add a "$$hashKey" property to the objects in your array if you use "track by". You also get performance benefits, if something in your array changes, angular doesn't recreate the entire DOM structure for your ng-repeat, it instead recreates the part of the DOM for the values in your array that have changed.

PHP - Session destroy after closing browser

Use a keep alive.

On login:

session_start();
$_SESSION['last_action'] = time();

An ajax call every few (eg 20) seconds:

windows.setInterval(keepAliveCall, 20000);

Server side keepalive.php:

session_start();
$_SESSION['last_action'] = time();

On every other action:

session_start();
if ($_SESSION['last_action'] < time() - 30 /* be a little tolerant here */) {
  // destroy the session and quit
}

Plotting time-series with Date labels on x-axis

Your code has lots of errors.

  • You are mixing up dm$Day and dm$day. Probably not the same thing
  • Your column headings are Date and Visits. So you would access them (I'm guessing) as dm$Date and dm$Visits
  • In the date field you have %Y-%m-%d this should be %m/%d/%Y

The following code should plot what you want:

dm$newday = as.Date(dm$Date, "%m/%d/%Y")
plot(dm$newday, dm$Visits)

Call multiple functions onClick ReactJS

Calling multiple functions on onClick for any element, you can create a wrapper function, something like this.

wrapperFunction = () => {
    //do something
    function 1();
    //do something
    function 2();
    //do something
    function 3();
}

These functions can be defined as a method on the parent class and then called from the wrapper function.

You may have the main element which will cause the onChange like this,

<a href='#' onClick={this.wrapperFunction}>Some Link</a>

iOS: Modal ViewController with transparent background

A complete method tested on iOS 7 and iOS 8.

@interface UIViewController (MBOverCurrentContextModalPresenting)

/// @warning Some method of viewControllerToPresent will called twice before iOS 8, e.g. viewWillAppear:.
- (void)MBOverCurrentContextPresentViewController:(UIViewController *)viewControllerToPresent animated:(BOOL)flag completion:(void (^)(void))completion;

@end

@implementation UIViewController (MBOverCurrentContextModalPresenting)

- (void)MBOverCurrentContextPresentViewController:(UIViewController *)viewControllerToPresent animated:(BOOL)flag completion:(void (^)(void))completion {
    UIViewController *presentingVC = self;

    // iOS 8 before
    if (floor(NSFoundationVersionNumber) <= NSFoundationVersionNumber_iOS_7_1) {
        UIViewController *root = presentingVC;
        while (root.parentViewController) {
            root = root.parentViewController;
        }

        [presentingVC presentViewController:viewControllerToPresent animated:YES completion:^{
            [viewControllerToPresent dismissViewControllerAnimated:NO completion:^{
                UIModalPresentationStyle orginalStyle = root.modalPresentationStyle;
                if (orginalStyle != UIModalPresentationCurrentContext) {
                    root.modalPresentationStyle = UIModalPresentationCurrentContext;
                }
                [presentingVC presentViewController:viewControllerToPresent animated:NO completion:completion];
                if (orginalStyle != UIModalPresentationCurrentContext) {
                    root.modalPresentationStyle = orginalStyle;
                }
            }];
        }];
        return;
    }

    UIModalPresentationStyle orginalStyle = viewControllerToPresent.modalPresentationStyle;
    if (orginalStyle != UIModalPresentationOverCurrentContext) {
        viewControllerToPresent.modalPresentationStyle = UIModalPresentationOverCurrentContext;
    }
    [presentingVC presentViewController:viewControllerToPresent animated:YES completion:completion];
    if (orginalStyle != UIModalPresentationOverCurrentContext) {
        viewControllerToPresent.modalPresentationStyle = orginalStyle;
    }
}

@end

How to swap String characters in Java?

Here is java sample code for swapping java chars recursively.. You can get full sample code at http://java2novice.com/java-interview-programs/string-reverse-recursive/

public String reverseString(String str){

    if(str.length() == 1){
        return str;
    } else {
        reverse += str.charAt(str.length()-1)
                +reverseString(str.substring(0,str.length()-1));
        return reverse;
    }
}

caching JavaScript files

The best (and only) method is to set correct HTTP headers, specifically these ones: "Expires", "Last-Modified", and "Cache-Control". How to do it depends on the server software you use.

In Improving performance… look for "Optimization on server side" for general considerations and relevant links and for "Client-side cache" for the Apache-specific advice.

If you are a fan of nginx (or nginx in plain English) like I am, you can easily configure it too:

location /images {
  ...
  expires 4h;
}

In the example above any file from /images/ will be cached on the client for 4 hours.

Now when you know right words to look for (HTTP headers "Expires", "Last-Modified", and "Cache-Control"), just peruse the documentation of the web server you use.

How do I change the number of open files limit in Linux?

If you are using Linux and you got the permission error, you will need to raise the allowed limit in the /etc/limits.conf or /etc/security/limits.conf file (where the file is located depends on your specific Linux distribution).

For example to allow anyone on the machine to raise their number of open files up to 10000 add the line to the limits.conf file.

* hard nofile 10000

Then logout and relogin to your system and you should be able to do:

ulimit -n 10000

without a permission error.

Configure apache to listen on port other than 80

In /etc/apache2/ports.conf, change the port as

Listen 8079

Then go to /etc/apache2/sites-enabled/000-default.conf

And change the first line as

<VirtualHost *: 8079>

Now restart

sudo service apache2 restart

Apache will now listen on port 8079 and redirect to /var/www/html

Specifying row names when reading in a file

If you used read.table() (or one of it's ilk, e.g. read.csv()) then the easy fix is to change the call to:

read.table(file = "foo.txt", row.names = 1, ....)

where .... are the other arguments you needed/used. The row.names argument takes the column number of the data file from which to take the row names. It need not be the first column. See ?read.table for details/info.

If you already have the data in R and can't be bothered to re-read it, or it came from another route, just set the rownames attribute and remove the first variable from the object (assuming obj is your object)

rownames(obj) <- obj[, 1]  ## set rownames
obj <- obj[, -1]           ## remove the first variable

jQuery checkbox checked state changed event

Bind to the change event instead of click. However, you will probably still need to check whether or not the checkbox is checked:

$(".checkbox").change(function() {
    if(this.checked) {
        //Do stuff
    }
});

The main benefit of binding to the change event over the click event is that not all clicks on a checkbox will cause it to change state. If you only want to capture events that cause the checkbox to change state, you want the aptly-named change event. Redacted in comments

Also note that I've used this.checked instead of wrapping the element in a jQuery object and using jQuery methods, simply because it's shorter and faster to access the property of the DOM element directly.

Edit (see comments)

To get all checkboxes you have a couple of options. You can use the :checkbox pseudo-selector:

$(":checkbox")

Or you could use an attribute equals selector:

$("input[type='checkbox']")

Best way to represent a fraction in Java?

One very minor improvement could potentially be to save the double value that you're computing so that you only compute it on the first access. This won't be a big win unless you're accessing this number a lot, but it's not overly difficult to do, either.

One additional point might be the error checking you do in the denominator...you automatically change 0 to 1. Not sure if this is correct for your particular application, but in general if someone is trying to divide by 0, something is very wrong. I'd let this throw an exception (a specialized exception if you feel it's needed) rather than change the value in a seemingly arbitrary way that isn't known to the user.

In constrast with some other comments, about adding methods to add subtract, etc...since you didn't mention needing them, I'm assuming you don't. And unless you're building a library that is really going to be used in many places or by other people, go with YAGNI (you ain't going to need it, so it shouldn't be there.)

add title attribute from css

As Quentin and other suggested this cannot totally be done with css(partially done with content attribute of css). Instead you should use javascript/jQuery to achieve this,

JS:

document.getElementsByClassName("mandatory")[0].title = "mandatory";

or using jQuery:

$('.mandatory').attr('title','mandatory');

_x000D_
_x000D_
document.getElementsByClassName('mandatory')[0].setAttribute('title', 'mandatory');_x000D_
_x000D_
$('.jmandatory').attr('title', 'jmandatory');
_x000D_
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>_x000D_
Place the Mouse Over the following elements to see the title,_x000D_
<br/><br/>_x000D_
<b><label class="mandatory">->Javascript Mandatory</label></b>_x000D_
<br/><br/>_x000D_
<b><label class="jmandatory">->jQuery Mandatory</label></b>
_x000D_
_x000D_
_x000D_

Error CS2001: Source file '.cs' could not be found

I had this problem, too.

Possible causes in my case: I had deleted a duplicated view twice and a view model. I reverted one of the deletes and then the InitializeComponent error appeared. I took these steps.

  1. I checked all of the solutions mentioned on this question. The class name and build action were correct.
  2. I Cleaned my Solution and rebuilt. Another error appeared. "Error CS2001: Source file '.cs' could not be found"
  3. I found this answer and followed the steps.
  4. I reloaded the project and cleaned/rebuilt again.
  5. My solution builds without errors and my application works now.

TypeError: 'list' object is not callable in python

If you are in a interactive session and don't want to restart you can remove the shadowing with

del list

How do I declare an array with a custom class?

In order to create an array of objects, the objects need a constructor that doesn't take any paramters (that creates a default form of the object, eg. with both strings empty). This is what the error message means. The compiler automatically generates a constructor which creates an empty object unless there are any other constructors.

If it makes sense for the array elements to be created empty (in which case the members acquire their default values, in this case, empty strings), you should:

-Write an empty constructor:

class name {
  public:
    string first;
    string last;

  name() { }
  name(string a, string b){
    first = a;
    last = b;
  }
};

-Or, if you don't need it, remove the existing constructor.

If an "empty" version of your class makes no sense, there is no good solution to provide initialisation paramters to all the elements of the array at compile time. You can:

  • Have a constructor create an empty version of the class anyway, and an init() function which does the real initialisation
  • Use a vector, and on initialisation create the objects and insert them into the vector, either using vector::insert or a loop, and trust that not doing it at compile time doesn't matter.
  • If the object can't be copied either, you can use an array/vector of smart pointers to the object and allocate them on initialisation.
  • If you can use C++11 I think (?) you can use initialiser lists to initialise a vector and intialise it (I'm not sure if that works with any contructor or only if the object is created from a single value of another type). Eg: .
 std::vector<std::string> v = { "xyzzy", "plugh", "abracadabra" };

`

In Python, what is the difference between ".append()" and "+= []"?

>>> a=[]
>>> a.append([1,2])
>>> a
[[1, 2]]
>>> a=[]
>>> a+=[1,2]
>>> a
[1, 2]

See that append adds a single element to the list, which may be anything. +=[] joins the lists.