Programs & Examples On #Rfc3161

RFC issued by the IETF in 2001 is about the "Internet X.509 Public Key Infrastructure Time-Stamp Protocol (TSP)"

How can I compare two lists in python and return matches

You can use

def returnMatches(a,b):
       return list(set(a) & set(b))

exit application when click button - iOS

exit(X), where X is a number (according to the doc) should work. But it is not recommended by Apple and won't be accepted by the AppStore. Why? Because of these guidelines (one of my app got rejected):

We found that your app includes a UI control for quitting the app. This is not in compliance with the iOS Human Interface Guidelines, as required by the App Store Review Guidelines.

Please refer to the attached screenshot/s for reference.

The iOS Human Interface Guidelines specify,

"Always Be Prepared to Stop iOS applications stop when people press the Home button to open a different application or use a device feature, such as the phone. In particular, people don’t tap an application close button or select Quit from a menu. To provide a good stopping experience, an iOS application should:

Save user data as soon as possible and as often as reasonable because an exit or terminate notification can arrive at any time.

Save the current state when stopping, at the finest level of detail possible so that people don’t lose their context when they start the application again. For example, if your app displays scrolling data, save the current scroll position."

> It would be appropriate to remove any mechanisms for quitting your app.

Plus, if you try to hide that function, it would be understood by the user as a crash.

How to change date format (MM/DD/YY) to (YYYY-MM-DD) in date picker

Try the following:

$('#to').datepicker({
      dateFormat: 'yy-mm-dd'
});

You'd think it would be yyyy-mm-dd but oh well :P

Pandas/Python: Set value of one column based on value in another column

one way to do this would be to use indexing with .loc.

Example

In the absence of an example dataframe, I'll make one up here:

import numpy as np
import pandas as pd

df = pd.DataFrame({'c1': list('abcdefg')})
df.loc[5, 'c1'] = 'Value'

>>> df
      c1
0      a
1      b
2      c
3      d
4      e
5  Value
6      g

Assuming you wanted to create a new column c2, equivalent to c1 except where c1 is Value, in which case, you would like to assign it to 10:

First, you could create a new column c2, and set it to equivalent as c1, using one of the following two lines (they essentially do the same thing):

df = df.assign(c2 = df['c1'])
# OR:
df['c2'] = df['c1']

Then, find all the indices where c1 is equal to 'Value' using .loc, and assign your desired value in c2 at those indices:

df.loc[df['c1'] == 'Value', 'c2'] = 10

And you end up with this:

>>> df
      c1  c2
0      a   a
1      b   b
2      c   c
3      d   d
4      e   e
5  Value  10
6      g   g

If, as you suggested in your question, you would perhaps sometimes just want to replace the values in the column you already have, rather than create a new column, then just skip the column creation, and do the following:

df['c1'].loc[df['c1'] == 'Value'] = 10
# or:
df.loc[df['c1'] == 'Value', 'c1'] = 10

Giving you:

>>> df
      c1
0      a
1      b
2      c
3      d
4      e
5     10
6      g

How correctly produce JSON by RESTful web service?

@POST
@Path ("Employee")
@Consumes("application/json")
@Produces("application/json")
public JSONObject postEmployee(JSONObject jsonObject)throws Exception{
    return jsonObject;
}       

No restricted globals

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

Install specific version using laravel installer

use laravel new blog --5.1
make sure you must have laravel installer 1.3.4 version.

Parsing PDF files (especially with tables) with PDFBox

It is not required for me to use the PDFBox library, so a solution that uses another library is fine

Camelot and Excalibur

You may want to try Python library Camelot, an open source library for Python. If you are not inclined to write code, you may use the web interface Excalibur created around Camelot. You "upload" the document to a localhost web server, and "download" the result from this localhost server.

Here is an example from using this python code:

import camelot
tables = camelot.read_pdf('foo.pdf', flavor="stream")
tables[0].to_csv('foo.csv')

The input is a pdf containing this table:

PDF-TREX sample

Sample table from the PDF-TREX set

No help is provided to camelot, it is working on its own by looking at pieces of text relative alignment. The result is returned in a csv file:

PDF table extracted from sample by camelot

PDF table extracted from sample by camelot

"Rules" can de added to help camelot identify where are fillets in sophisticated tables:

Rule added to Excalibur
Rule added in Excalibur. Source

GitHub:

The two projects are active.

Here is a comparison with other software (with test based on actual documents), Tabula, pdfplumber, pdftables, pdf-table-extract.


I want is to be able to parse the file and know what each parsed number means

You cannot do that automatically, as pdf is not semantically structured.

Book versus document

Pdf "documents" are unstructured from a semantic standpoint (it's like a notepad file), the pdf document gives instructions on where to print a text fragment, unrelated to other fragments of the same section, there is no separation between content (what to print, and whether this is a fragment of a title, a table or a footnote) and the visual representation (font, location, etc). Pdf is an extension of PostScript, which describes a Hello world! page this way:

!PS
 /Courier             % font
 20 selectfont        % size
 72 500 moveto        % current location to print at
 (Hello world!) show  % add text fragment
 showpage             % print all on the page

(Wikipedia).
One can imagine what a table looks like with the same instructions.

We could say html is not clearer, however there is a big difference: Html describes the content semantically (title, paragraph, list, table header, table cell, ...) and associates the css to produce a visual form, hence content is fully accessible. In this sense, html is a simplified descendant of sgml which puts constraints to allow data processing:

Markup should describe a document's structure and other attributes rather than specify the processing that needs to be performed, because it is less likely to conflict with future developments.

exactly the opposite of PostScript/Pdf. SGML is used in publishing. Pdf doesn't embed this semantical structure, it carries only the css-equivalent associated to plain character strings which may not be complete words or sentences. Pdf is used for closed documents and now for the so-called workflow management.

After having experimented the uncertainty and difficulty in trying to extract data from pdf, it's clear pdf is not at all a solution to preserve a document content for the future (in spite Adobe has obtained from their pairs a pdf standard).

What is actually preserved well is the printed representation, as the pdf was fully dedicated to this aspect when created. Pdf are nearly as dead as printed books.

When reusing the content matters, one must rely again on manual re-entering of data, like from a printed book (possibly trying to do some OCR on it). This is more and more true, as many pdf even prevent the use of copy-paste, introducing multiple spaces between words or produce an unordered characters gibberish when some "optimization" is done for web use.

When the content of the document, not its printed representation, is valuable, then pdf is not the correct format. Even Adobe is unable to recreate perfectly the source of a document from its pdf rendering.

So open data should never be released in pdf format, this limits their use to reading and printing (when allowed), and makes reuse harder or impossible.

Search for "does-not-contain" on a DataFrame in pandas

You can use the invert (~) operator (which acts like a not for boolean data):

new_df = df[~df["col"].str.contains(word)]

, where new_df is the copy returned by RHS.

contains also accepts a regular expression...


If the above throws a ValueError, the reason is likely because you have mixed datatypes, so use na=False:

new_df = df[~df["col"].str.contains(word, na=False)]

Or,

new_df = df[df["col"].str.contains(word) == False]

How to stop creating .DS_Store on Mac?

Put following line into your ".profile" file.

Open .profile file and copy this line

find ~/ -name '.DS_Store' -delete

When you open terminal window it will automatically delete your .DS_Store file for you.

What is the difference between HTTP and REST?

REST is not necessarily tied to HTTP. RESTful web services are just web services that follow a RESTful architecture.

What is Rest -
1- Client-server
2- Stateless
3- Cacheable
4- Layered system
5- Code on demand
6- Uniform interface

ORA-12505, TNS:listener does not currently know of SID given in connect descriptor

I too faced the same issue. I had installed Oracle Express edition 10g in Windows XP OS using VMware and it was working fine. Since it was very awkward typing SQL queries in the SQL utility provided by 10g and since I was used to working with SQL developer, I installed 32 bit SQL developer in XP and tried connecting to my DB SID "XE". But the connection failed with error-ORA-12505 TNS listener doesn't currently know of SID given in connect descriptor. I was at sea as to how this problem occurred since it was working fine with the SQL utility and I had also created few Informatica mappings using the same. I did browse a lot on this stuff hither thither and applied the suggestions offered to me after pinging the status of "lsnrctl" on public forums but to no avail. However, this morning I tried creating a new connection again, and Voila, it worked with no issues. I am guessing after reading in few posts that sometimes listener listens before the DB connects or something(pardon me for my crude reference as I am a newbie here) but I suggest to just restart the machine and check again.

Why can I not switch branches?

You need to commit or destroy any unsaved changes before you switch branch.

Git won't let you switch branch if it means unsaved changes would be removed.

Change the background color in a twitter bootstrap modal?

I used couple of hours trying to figure how to remove background from launched modal, so far tried

.modal-backdrop {    background: none; }

Didn't work even I have tried to work with javascript like

 <script type="text/javascript">   
 $('#modal-id').on('shown.bs.modal',  function () {
       $(".modal-backdrop.in").hide();     })
</script>

Also didn't work either. I just added

data-backdrop="false"

to

<div class="modal fade" id="myModal" data-backdrop="false">......</div>

And Applying css CLASS

.modal {     background-color: transparent !important;  }

Now its working like a charm This worked with Bootstrap 3

How to create a number picker dialog?

For kotlin lovers.

fun numberPickerCustom() {
    val d = AlertDialog.Builder(context)
    val inflater = this.layoutInflater
    val dialogView = inflater.inflate(R.layout.number_picker_dialog, null)
    d.setTitle("Title")
    d.setMessage("Message")
    d.setView(dialogView)
    val numberPicker = dialogView.findViewById<NumberPicker>(R.id.dialog_number_picker)
    numberPicker.maxValue = 15
    numberPicker.minValue = 1
    numberPicker.wrapSelectorWheel = false
    numberPicker.setOnValueChangedListener { numberPicker, i, i1 -> println("onValueChange: ") }
    d.setPositiveButton("Done") { dialogInterface, i ->
        println("onClick: " + numberPicker.value)       
        }
    d.setNegativeButton("Cancel") { dialogInterface, i -> }
    val alertDialog = d.create()
    alertDialog.show()
}

and number_picker_dialog.xml

<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:layout_gravity="center"
    android:gravity="center_horizontal">

    <NumberPicker
        android:id="@+id/dialog_number_picker"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"/>
</LinearLayout>

Excel VBA calling sub from another sub with multiple inputs, outputs of different sizes

To call a sub inside another sub you only need to do:

Call Subname()

So where you have CalculateA(Nc,kij, xi, a1, a) you need to have call CalculateA(Nc,kij, xi, a1, a)

As the which runs first problem it's for you to decide, when you want to run a sub you can go to the macro list select the one you want to run and run it, you can also give it a key shortcut, therefore you will only have to press those keys to run it. Although, on secondary subs, I usually do it as Private sub CalculateA(...) cause this way it does not appear in the macro list and it's easier to work

Hope it helps, Bruno

PS: If you have any other question just ask, but this isn't a community where you ask for code, you come here with a question or a code that isn't running and ask for help, not like you did "It would be great if you could write it in the Excel VBA format."

Include CSS and Javascript in my django template

Refer django docs on static files.

In settings.py:

import os
CURRENT_PATH = os.path.abspath(os.path.dirname(__file__).decode('utf-8'))

MEDIA_ROOT = os.path.join(CURRENT_PATH, 'media')

MEDIA_URL = '/media/'

STATIC_ROOT = 'static/'

STATIC_URL = '/static/'

STATICFILES_DIRS = (
                    os.path.join(CURRENT_PATH, 'static'),
)

Then place your js and css files static folder in your project. Not in media folder.

In views.py:

from django.shortcuts import render_to_response, RequestContext

def view_name(request):
    #your stuff goes here
    return render_to_response('template.html', locals(), context_instance = RequestContext(request))

In template.html:

<link rel="stylesheet" type="text/css" href="{{ STATIC_URL }}css/style.css" />
<script type="text/javascript" src="{{ STATIC_URL }}js/jquery-1.8.3.min.js"></script>

In urls.py:

from django.conf import settings
urlpatterns += patterns('',
    url(r'^media/(?P<path>.*)$', 'django.views.static.serve', {'document_root': settings.MEDIA_ROOT, 'show_indexes': True}),
)

Project file structure can be found here in imgbin.

in_array multiple values

Going off of @Rok Kralj answer (best IMO) to check if any of needles exist in the haystack, you can use (bool) instead of !! which sometimes can be confusing during code review.

function in_array_any($needles, $haystack) {
   return (bool)array_intersect($needles, $haystack);
}

echo in_array_any( array(3,9), array(5,8,3,1,2) ); // true, since 3 is present
echo in_array_any( array(4,9), array(5,8,3,1,2) ); // false, neither 4 nor 9 is present

https://glot.io/snippets/f7dhw4kmju

Angularjs on page load call function

you can also use the below code.

function activateController(){
     console.log('HELLO WORLD');
}

$scope.$on('$viewContentLoaded', function ($evt, data) {
    activateController();
});

Serialize Class containing Dictionary member

Instead of using XmlSerializer you can use a System.Runtime.Serialization.DataContractSerializer. This can serialize dictionaries and interfaces no sweat.

Here is a link to a full example, http://theburningmonk.com/2010/05/net-tips-xml-serialize-or-deserialize-dictionary-in-csharp/

Things possible in IntelliJ that aren't possible in Eclipse?

Structural search and replace.

For example, search for something like:

  System.out.println($string$ + $expr$);

Where $string$ is a literal, and $expr$ is an expression of type my.package.and.Class, and then replace with:

  $expr$.inspect($string$);

Access to file download dialog in Firefox

Not that I know of. But you can configure Firefox to automatically start the download and save the file in a specific place. Your test could then check that the file actually arrived.

Using an IF Statement in a MySQL SELECT query

try this code worked for me

SELECT user_display_image AS user_image,
       user_display_name AS user_name,
       invitee_phone,
       (CASE WHEN invitee_status = 1 THEN "attending"
             WHEN invitee_status = 2 THEN "unsure"
             WHEN invitee_status = 3 THEN "declined"
             WHEN invitee_status = 0 THEN "notreviwed"
       END) AS invitee_status
  FROM your_table

How to handle iframe in Selenium WebDriver using java

Below approach of frame handling : When no id or name is given incase of nested frame

WebElement element =driver.findElement(By.xpath(".//*[@id='block-block19']//iframe"));
driver.switchTo().frame(element);
driver.findElement(By.xpath(".//[@id='carousel']/li/div/div[3]/a")).click();

Xcode/Simulator: How to run older iOS version?

To anyone else who finds this older question, you can now download all old versions.

Xcode -> Preferences -> Components (Click on Simulators tab).

Install all the versions you want/need.

To show all installed simulators:

Target -> In dropdown "deployment target" choose the installed version with lowest version nr.

You should now see all your available simulators in the dropdown.

Fetch: reject promise and catch the error if status is not OK?

Fetch promises only reject with a TypeError when a network error occurs. Since 4xx and 5xx responses aren't network errors, there's nothing to catch. You'll need to throw an error yourself to use Promise#catch.

A fetch Response conveniently supplies an ok , which tells you whether the request succeeded. Something like this should do the trick:

fetch(url).then((response) => {
  if (response.ok) {
    return response.json();
  } else {
    throw new Error('Something went wrong');
  }
})
.then((responseJson) => {
  // Do something with the response
})
.catch((error) => {
  console.log(error)
});

Scrolling to element using webdriver?

This can be done using driver.execute_script():-

driver.execute_script("document.getElementById('myelementid').scrollIntoView();")

Redirecting from cshtml page

This clearly is a bad case of controller logic in a view. It would be better to do this in a controller and return the desired view.

[ChildActionOnly]
public ActionResult Results() 
{
    EnumerableRowCollection<DataRow> custs = ViewBag.Customers;
    bool anyRows = custs.Any();

    if(anyRows == false)
    {
        return View("NoResults");
    }
    else
    {
        return View("OtherView");
    }
}

Modify NoResults.cshtml to a Partial.

And call this as a Partial view in the parent view

@Html.Partial("Results")

You might have to pass the Customer collection as a model to the Result action or in a ViewDataDictionary due to reasons explained here: Can't access ViewBag in a partial view in ASP.NET MVC3

The ChildActionOnly attribute will make sure you cannot go to this page by navigating and that this view must be rendered as a partial, thus by a parent view. cfr: Using ChildActionOnly in MVC

Sending email with PHP from an SMTP server

When you are sending an e-mail through a server that requires SMTP Auth, you really need to specify it, and set the host, username and password (and maybe the port if it is not the default one - 25).

For example, I usually use PHPMailer with similar settings to this ones:

$mail = new PHPMailer();

// Settings
$mail->IsSMTP();
$mail->CharSet = 'UTF-8';

$mail->Host       = "mail.example.com"; // SMTP server example
$mail->SMTPDebug  = 0;                     // enables SMTP debug information (for testing)
$mail->SMTPAuth   = true;                  // enable SMTP authentication
$mail->Port       = 25;                    // set the SMTP port for the GMAIL server
$mail->Username   = "username"; // SMTP account username example
$mail->Password   = "password";        // SMTP account password example

// Content
$mail->isHTML(true);                                  // Set email format to HTML
$mail->Subject = 'Here is the subject';
$mail->Body    = 'This is the HTML message body <b>in bold!</b>';
$mail->AltBody = 'This is the body in plain text for non-HTML mail clients';

$mail->send();

You can find more about PHPMailer here: https://github.com/PHPMailer/PHPMailer

Event detect when css property changed using Jquery

Note

Mutation events have been deprecated since this post was written, and may not be supported by all browsers. Instead, use a mutation observer.

Yes you can. DOM L2 Events module defines mutation events; one of them - DOMAttrModified is the one you need. Granted, these are not widely implemented, but are supported in at least Gecko and Opera browsers.

Try something along these lines:

document.documentElement.addEventListener('DOMAttrModified', function(e){
  if (e.attrName === 'style') {
    console.log('prevValue: ' + e.prevValue, 'newValue: ' + e.newValue);
  }
}, false);

document.documentElement.style.display = 'block';

You can also try utilizing IE's "propertychange" event as a replacement to DOMAttrModified. It should allow to detect style changes reliably.

Convert a timedelta to days, hours and minutes

If you have a datetime.timedelta value td, td.days already gives you the "days" you want. timedelta values keep fraction-of-day as seconds (not directly hours or minutes) so you'll indeed have to perform "nauseatingly simple mathematics", e.g.:

def days_hours_minutes(td):
    return td.days, td.seconds//3600, (td.seconds//60)%60

Disable sorting on last column when using jQuery DataTables

The aoColumnDefs' aTargets parameter lets you give indexes offset from the right (use a negative number) as well as from the left. So you could do:

aoColumnDefs: [
  {
     bSortable: false,
     aTargets: [ -1 ]
  }
]

The equivalent new API (for DataTables 1.10+) would be:

columnDefs: [
   { orderable: false, targets: -1 }
]

Git branching: master vs. origin/master vs. remotes/origin/master

Take a clone of a remote repository and run git branch -a (to show all the branches git knows about). It will probably look something like this:

* master
  remotes/origin/HEAD -> origin/master
  remotes/origin/master

Here, master is a branch in the local repository. remotes/origin/master is a branch named master on the remote named origin. You can refer to this as either origin/master, as in:

git diff origin/master..master

You can also refer to it as remotes/origin/master:

git diff remotes/origin/master..master

These are just two different ways of referring to the same thing (incidentally, both of these commands mean "show me the changes between the remote master branch and my master branch).

remotes/origin/HEAD is the default branch for the remote named origin. This lets you simply say origin instead of origin/master.

How to test whether a service is running from the command line

I've found this:

  sc query "ServiceName" | findstr RUNNING  

seems to do roughly the right thing. But, I'm worried that's not generalized enough to work on non-english operating systems.

Node.js Error: Cannot find module express

I'm not proud sharing this, but in my case I had:

 require('express.handlebars')

 //and the correct form is:
 require('express-handlebars'); //Use dash instead.

Replace given value in vector

Perhaps replace is what you are looking for:

> x = c(3, 2, 1, 0, 4, 0)
> replace(x, x==0, 1)
[1] 3 2 1 1 4 1

Or, if you don't have x (any specific reason why not?):

replace(c(3, 2, 1, 0, 4, 0), c(3, 2, 1, 0, 4, 0)==0, 1)

Many people are familiar with gsub, so you can also try either of the following:

as.numeric(gsub(0, 1, x))
as.numeric(gsub(0, 1, c(3, 2, 1, 0, 4, 0)))

Update

After reading the comments, perhaps with is an option:

with(data.frame(x = c(3, 2, 1, 0, 4, 0)), replace(x, x == 0, 1))

Python function attributes - uses and abuses

I've used them as static variables for a function. For example, given the following C code:

int fn(int i)
{
    static f = 1;
    f += i;
    return f;
}

I can implement the function similarly in Python:

def fn(i):
    fn.f += i
    return fn.f
fn.f = 1

This would definitely fall into the "abuses" end of the spectrum.

How can you make a custom keyboard in Android?

System keyboard

This answer tells how to make a custom system keyboard that can be used in any app that a user has installed on their phone. If you want to make a keyboard that will only be used within your own app, then see my other answer.

The example below will look like this. You can modify it for any keyboard layout.

enter image description here

The following steps show how to create a working custom system keyboard. As much as possible I tried to remove any unnecessary code. If there are other features that you need, I provided links to more help at the end.

1. Start a new Android project

I named my project "Custom Keyboard". Call it whatever you want. There is nothing else special here. I will just leave the MainActivity and "Hello World!" layout as it is.

2. Add the layout files

Add the following two files to your app's res/layout folder:

  • keyboard_view.xml
  • key_preview.xml

keyboard_view.xml

This view is like a container that will hold our keyboard. In this example there is only one keyboard, but you could add other keyboards and swap them in and out of this KeyboardView.

<?xml version="1.0" encoding="utf-8"?>
<android.inputmethodservice.KeyboardView
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/keyboard_view"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:keyPreviewLayout="@layout/key_preview"
    android:layout_alignParentBottom="true">

</android.inputmethodservice.KeyboardView>

key_preview.xml

The key preview is a layout that pops up when you press a keyboard key. It just shows what key you are pressing (in case your big, fat fingers are covering it). This isn't a multiple choice popup. For that you should check out the Candidates view.

<?xml version="1.0" encoding="utf-8"?>
<TextView
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:gravity="center"
    android:background="@android:color/white"
    android:textColor="@android:color/black"
    android:textSize="30sp">
</TextView>

3. Add supporting xml files

Create an xml folder in your res folder. (Right click res and choose New > Directory.)

Then add the following two xml files to it. (Right click the xml folder and choose New > XML resource file.)

  • number_pad.xml
  • method.xml

number_pad.xml

This is where it starts to get more interesting. This Keyboard defines the layout of the keys.

<?xml version="1.0" encoding="utf-8"?>
<Keyboard xmlns:android="http://schemas.android.com/apk/res/android"
    android:keyWidth="20%p"
    android:horizontalGap="5dp"
    android:verticalGap="5dp"
    android:keyHeight="60dp">

    <Row>
        <Key android:codes="49" android:keyLabel="1" android:keyEdgeFlags="left"/>
        <Key android:codes="50" android:keyLabel="2"/>
        <Key android:codes="51" android:keyLabel="3"/>
        <Key android:codes="52" android:keyLabel="4"/>
        <Key android:codes="53" android:keyLabel="5" android:keyEdgeFlags="right"/>
    </Row>

    <Row>
        <Key android:codes="54" android:keyLabel="6" android:keyEdgeFlags="left"/>
        <Key android:codes="55" android:keyLabel="7"/>
        <Key android:codes="56" android:keyLabel="8"/>
        <Key android:codes="57" android:keyLabel="9"/>
        <Key android:codes="48" android:keyLabel="0" android:keyEdgeFlags="right"/>
    </Row>

    <Row>
        <Key android:codes="-5"
             android:keyLabel="DELETE"
             android:keyWidth="40%p"
             android:keyEdgeFlags="left"
             android:isRepeatable="true"/>
        <Key android:codes="10"
             android:keyLabel="ENTER"
             android:keyWidth="60%p"
             android:keyEdgeFlags="right"/>
    </Row>

</Keyboard>

Here are some things to note:

  • keyWidth: This is the default width of each key. The 20%p means that each key should take up 20% of the width of the parent. It can be overridden by individual keys, though, as you can see happened with the Delete and Enter keys in the third row.
  • keyHeight: It is hard coded here, but you could use something like @dimen/key_height to set it dynamically for different screen sizes.
  • Gap: The horizontal and vertical gap tells how much space to leave between keys. Even if you set it to 0px there is still a small gap.
  • codes: This can be a Unicode or custom code value that determines what happens or what is input when the key is pressed. See keyOutputText if you want to input a longer Unicode string.
  • keyLabel: This is the text that is displayed on the key.
  • keyEdgeFlags: This indicates which edge the key should be aligned to.
  • isRepeatable: If you hold down the key it will keep repeating the input.

method.xml

This file tells the system the input method subtypes that are available. I am just including a minimal version here.

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

    <subtype
        android:imeSubtypeMode="keyboard"/>

</input-method>

4. Add the Java code to handle key input

Create a new Java file. Let's call it MyInputMethodService. This file ties everything together. It handles input received from the keyboard and sends it on to whatever view is receiving it (an EditText, for example).

public class MyInputMethodService extends InputMethodService implements KeyboardView.OnKeyboardActionListener {

    @Override
    public View onCreateInputView() {
        // get the KeyboardView and add our Keyboard layout to it
        KeyboardView keyboardView = (KeyboardView) getLayoutInflater().inflate(R.layout.keyboard_view, null);
        Keyboard keyboard = new Keyboard(this, R.xml.number_pad);
        keyboardView.setKeyboard(keyboard);
        keyboardView.setOnKeyboardActionListener(this);
        return keyboardView;
    }

    @Override
    public void onKey(int primaryCode, int[] keyCodes) {

        InputConnection ic = getCurrentInputConnection();
        if (ic == null) return;
        switch (primaryCode) {
            case Keyboard.KEYCODE_DELETE:
                CharSequence selectedText = ic.getSelectedText(0);
                if (TextUtils.isEmpty(selectedText)) {
                    // no selection, so delete previous character
                    ic.deleteSurroundingText(1, 0);
                } else {
                    // delete the selection
                    ic.commitText("", 1);
                }
                break;
            default:
                char code = (char) primaryCode;
                ic.commitText(String.valueOf(code), 1);
        }
    }

    @Override
    public void onPress(int primaryCode) { }

    @Override
    public void onRelease(int primaryCode) { }

    @Override
    public void onText(CharSequence text) { }

    @Override
    public void swipeLeft() { }

    @Override
    public void swipeRight() { }

    @Override
    public void swipeDown() { }

    @Override
    public void swipeUp() { }
}

Notes:

  • The OnKeyboardActionListener listens for keyboard input. It is also requires all those empty methods in this example.
  • The InputConnection is what is used to send input to another view like an EditText.

5. Update the manifest

I put this last rather than first because it refers to the files we already added above. To register your custom keyboard as a system keyboard, you need to add a service section to your AndroidManifest.xml file. Put it in the application section after activity.

<manifest ...>
    <application ... >
        <activity ... >
            ...
        </activity>

        <service
            android:name=".MyInputMethodService"
            android:label="Keyboard Display Name"
            android:permission="android.permission.BIND_INPUT_METHOD">
            <intent-filter>
                <action android:name="android.view.InputMethod"/>
            </intent-filter>
            <meta-data
                android:name="android.view.im"
                android:resource="@xml/method"/>
        </service>

    </application>
</manifest>

That's it! You should be able to run your app now. However, you won't see much until you enable your keyboard in the settings.

6. Enable the keyboard in Settings

Every user who wants to use your keyboard will have to enable it in the Android settings. For detailed instructions on how to do that, see the following link:

Here is a summary:

  • Go to Android Settings > Languages and input > Current keyboard > Choose keyboards.
  • You should see your Custom Keyboard on the list. Enable it.
  • Go back and choose Current keyboard again. You should see your Custom Keyboard on the list. Choose it.

Now you should be able to use your keyboard anywhere that you can type in Android.

Further study

The keyboard above is usable, but to create a keyboard that other people will want to use you will probably have to add more functionality. Study the links below to learn how.

Going On

Don't like how the standard KeyboardView looks and behaves? I certainly don't. It looks like it hasn't been updated since Android 2.0. How about all those custom keyboards in the Play Store? They don't look anything like the ugly keyboard above.

The good news is that you can completely customize your own keyboard's look and behavior. You will need to do the following things:

  1. Create your own custom keyboard view that subclasses ViewGroup. You could fill it with Buttons or even make your own custom key views that subclass View. If you use popup views, then note this.
  2. Add a custom event listener interface in your keyboard. Call its methods for things like onKeyClicked(String text) or onBackspace().
  3. You don't need to add the keyboard_view.xml, key_preview.xml, or number_pad.xml described in the directions above since these are all for the standard KeyboardView. You will handle all these UI aspects in your custom view.
  4. In your MyInputMethodService class, implement the custom keyboard listener that you defined in your keyboard class. This is in place of KeyboardView.OnKeyboardActionListener, which is no longer needed.
  5. In your MyInputMethodService class's onCreateInputView() method, create and return an instance of your custom keyboard. Don't forget to set the keyboard's custom listener to this.

disable textbox using jquery?

I would've done it slightly different

 <input type="radio" value="1" name="userradiobtn" id="userradiobtn" />   
 <input type="radio" value="2" name="userradiobtn" id="userradiobtn" />    
 <input type="radio" value="3" name="userradiobtn" id="userradiobtn" class="disablebox"/>   
 <input type="checkbox" value="4" name="chkbox" id="chkbox" class="showbox"/>    
 <input type="text" name="usertxtbox" id="usertxtbox" class="showbox" />   

Notice class attribute

 $(document).ready(function() {      
    $('.disablebox').click(function() {
        $('.showbox').attr("disabled", true);           
    });
});

This way should you need to add more radio buttons you don't need to worry about changing the javascript

What does Ruby have that Python doesn't, and vice versa?

Shamelessly copy/pasted from: Alex Martelli answer on "What's better about Ruby than Python" thread from comp.lang.python mailing list.

Aug 18 2003, 10:50 am Erik Max Francis wrote:

"Brandon J. Van Every" wrote:

What's better about Ruby than Python? I'm sure there's something. What is it?

Wouldn't it make much more sense to ask Ruby people this, rather than Python people?

Might, or might not, depending on one's purposes -- for example, if one's purposes include a "sociological study" of the Python community, then putting questions to that community is likely to prove more revealing of information about it, than putting them elsewhere:-).

Personally, I gladly took the opportunity to follow Dave Thomas' one-day Ruby tutorial at last OSCON. Below a thin veneer of syntax differences, I find Ruby and Python amazingly similar -- if I was computing the minimum spanning tree among just about any set of languages, I'm pretty sure Python and Ruby would be the first two leaves to coalesce into an intermediate node:-).

Sure, I do get weary, in Ruby, of typing the silly "end" at the end of each block (rather than just unindenting) -- but then I do get to avoid typing the equally-silly ':' which Python requires at the start of each block, so that's almost a wash:-). Other syntax differences such as '@foo' versus 'self.foo', or the higher significance of case in Ruby vs Python, are really just about as irrelevant to me.

Others no doubt base their choice of programming languages on just such issues, and they generate the hottest debates -- but to me that's just an example of one of Parkinson's Laws in action (the amount on debate on an issue is inversely proportional to the issue's actual importance).

Edit (by AM 6/19/2010 11:45): this is also known as "painting the bikeshed" (or, for short, "bikeshedding") -- the reference is, again, to Northcote Parkinson, who gave "debates on what color to paint the bikeshed" as a typical example of "hot debates on trivial topics". (end-of-Edit).

One syntax difference that I do find important, and in Python's favor -- but other people will no doubt think just the reverse -- is "how do you call a function which takes no parameters". In Python (like in C), to call a function you always apply the "call operator" -- trailing parentheses just after the object you're calling (inside those trailing parentheses go the args you're passing in the call -- if you're passing no args, then the parentheses are empty). This leaves the mere mention of any object, with no operator involved, as meaning just a reference to the object -- in any context, without special cases, exceptions, ad-hoc rules, and the like. In Ruby (like in Pascal), to call a function WITH arguments you pass the args (normally in parentheses, though that is not invariably the case) -- BUT if the function takes no args then simply mentioning the function implicitly calls it. This may meet the expectations of many people (at least, no doubt, those whose only previous experience of programming was with Pascal, or other languages with similar "implicit calling", such as Visual Basic) -- but to me, it means the mere mention of an object may EITHER mean a reference to the object, OR a call to the object, depending on the object's type -- and in those cases where I can't get a reference to the object by merely mentioning it I will need to use explicit "give me a reference to this, DON'T call it!" operators that aren't needed otherwise. I feel this impacts the "first-classness" of functions (or methods, or other callable objects) and the possibility of interchanging objects smoothly. Therefore, to me, this specific syntax difference is a serious black mark against Ruby -- but I do understand why others would thing otherwise, even though I could hardly disagree more vehemently with them:-).

Below the syntax, we get into some important differences in elementary semantics -- for example, strings in Ruby are mutable objects (like in C++), while in Python they are not mutable (like in Java, or I believe C#). Again, people who judge primarily by what they're already familiar with may think this is a plus for Ruby (unless they're familiar with Java or C#, of course:-). Me, I think immutable strings are an excellent idea (and I'm not surprised that Java, independently I think, reinvented that idea which was already in Python), though I wouldn't mind having a "mutable string buffer" type as well (and ideally one with better ease-of-use than Java's own "string buffers"); and I don't give this judgment because of familiarity -- before studying Java, apart from functional programming languages where all data are immutable, all the languages I knew had mutable strings -- yet when I first saw the immutable-string idea in Java (which I learned well before I learned Python), it immediately struck me as excellent, a very good fit for the reference-semantics of a higher level programming language (as opposed to the value-semantics that fit best with languages closer to the machine and farther from applications, such as C) with strings as a first-class, built-in (and pretty crucial) data type.

Ruby does have some advantages in elementary semantics -- for example, the removal of Python's "lists vs tuples" exceedingly subtle distinction. But mostly the score (as I keep it, with simplicity a big plus and subtle, clever distinctions a notable minus) is against Ruby (e.g., having both closed and half-open intervals, with the notations a..b and a...b [anybody wants to claim that it's obvious which is which?-)], is silly -- IMHO, of course!). Again, people who consider having a lot of similar but subtly different things at the core of a language a PLUS, rather than a MINUS, will of course count these "the other way around" from how I count them:-).

Don't be misled by these comparisons into thinking the two languages are very different, mind you. They aren't. But if I'm asked to compare "capelli d'angelo" to "spaghettini", after pointing out that these two kinds of pasta are just about undistinguishable to anybody and interchangeable in any dish you might want to prepare, I would then inevitably have to move into microscopic examination of how the lengths and diameters imperceptibly differ, how the ends of the strands are tapered in one case and not in the other, and so on -- to try and explain why I, personally, would rather have capelli d'angelo as the pasta in any kind of broth, but would prefer spaghettini as the pastasciutta to go with suitable sauces for such long thin pasta forms (olive oil, minced garlic, minced red peppers, and finely ground anchovies, for example - but if you sliced the garlic and peppers instead of mincing them, then you should choose the sounder body of spaghetti rather than the thinner evanescence of spaghettini, and would be well advised to forego the achovies and add instead some fresh spring basil [or even -- I'm a heretic...! -- light mint...] leaves -- at the very last moment before serving the dish). Ooops, sorry, it shows that I'm traveling abroad and haven't had pasta for a while, I guess. But the analogy is still pretty good!-)

So, back to Python and Ruby, we come to the two biggies (in terms of language proper -- leaving the libraries, and other important ancillaries such as tools and environments, how to embed/extend each language, etc, etc, out of it for now -- they wouldn't apply to all IMPLEMENTATIONS of each language anyway, e.g., Jython vs Classic Python being two implementations of the Python language!):

  1. Ruby's iterators and codeblocks vs Python's iterators and generators;

  2. Ruby's TOTAL, unbridled "dynamicity", including the ability
    to "reopen" any existing class, including all built-in ones, and change its behavior at run-time -- vs Python's vast but bounded dynamicity, which never changes the behavior of existing built-in classes and their instances.

Personally, I consider 1 a wash (the differences are so deep that I could easily see people hating either approach and revering the other, but on MY personal scales the pluses and minuses just about even up); and 2 a crucial issue -- one that makes Ruby much more suitable for "tinkering", BUT Python equally more suitable for use in large production applications. It's funny, in a way, because both languages are so MUCH more dynamic than most others, that in the end the key difference between them from my POV should hinge on that -- that Ruby "goes to eleven" in this regard (the reference here is to "Spinal Tap", of course). In Ruby, there are no limits to my creativity -- if I decide that all string comparisons must become case-insensitive, I CAN DO THAT! I.e., I can dynamically alter the built-in string class so that a = "Hello World" b = "hello world" if a == b print "equal!\n" else print "different!\n" end WILL print "equal". In python, there is NO way I can do that. For the purposes of metaprogramming, implementing experimental frameworks, and the like, this amazing dynamic ability of Ruby is extremely appealing. BUT -- if we're talking about large applications, developed by many people and maintained by even more, including all kinds of libraries from diverse sources, and needing to go into production in client sites... well, I don't WANT a language that is QUITE so dynamic, thank you very much. I loathe the very idea of some library unwittingly breaking other unrelated ones that rely on those strings being different -- that's the kind of deep and deeply hidden "channel", between pieces of code that LOOK separate and SHOULD BE separate, that spells d-e-a-t-h in large-scale programming. By letting any module affect the behavior of any other "covertly", the ability to mutate the semantics of built-in types is just a BAD idea for production application programming, just as it's cool for tinkering.

If I had to use Ruby for such a large application, I would try to rely on coding-style restrictions, lots of tests (to be rerun whenever ANYTHING changes -- even what should be totally unrelated...), and the like, to prohibit use of this language feature. But NOT having the feature in the first place is even better, in my opinion -- just as Python itself would be an even better language for application programming if a certain number of built-ins could be "nailed down", so I KNEW that, e.g., len("ciao") is 4 (rather than having to worry subliminally about whether somebody's changed the binding of name 'len' in the builtins module...). I do hope that eventually Python does "nail down" its built-ins.

But the problem's minor, since rebinding built-ins is quite a deprecated as well as a rare practice in Python. In Ruby, it strikes me as major -- just like the too powerful macro facilities of other languages (such as, say, Dylan) present similar risks in my own opinion (I do hope that Python never gets such a powerful macro system, no matter the allure of "letting people define their own domain-specific little languages embedded in the language itself" -- it would, IMHO, impair Python's wonderful usefulness for application programming, by presenting an "attractive nuisance" to the would-be tinkerer who lurks in every programmer's heart...).

Alex

T-SQL: Using a CASE in an UPDATE statement to update certain columns depending on a condition

I believe that you can omit updating the "non-desired" columns by adjusting the other answers as follows:

update table set
    columnx = (case when condition1 then 25 end),
    columny = (case when condition2 then 25 end)`

As I understand it, this will update only when the condition is met.

After reading all the comments, this is the most efficient:

Update table set ColumnX = 25 where Condition1
 Update table set ColumnY = 25 where Condition1`

Sample Table:

CREATE TABLE [dbo].[tblTest](
    [ColX] [int] NULL,
    [ColY] [int] NULL,
    [ColConditional] [bit] NULL,
    [id] [int] IDENTITY(1,1) NOT NULL
) ON [PRIMARY]

Sample Data:

Insert into tblTest (ColX, ColY, ColConditional) values (null, null, 0)
Insert into tblTest (ColX, ColY, ColConditional) values (null, null, 0)
Insert into tblTest (ColX, ColY, ColConditional) values (null, null, 1)
Insert into tblTest (ColX, ColY, ColConditional) values (null, null, 1)
Insert into tblTest (ColX, ColY, ColConditional) values (1, null, null)
Insert into tblTest (ColX, ColY, ColConditional) values (2, null, null)
Insert into tblTest (ColX, ColY, ColConditional) values (null, 1, null)
Insert into tblTest (ColX, ColY, ColConditional) values (null, 2, null)

Now I assume you can write a conditional that handles nulls. For my example, I am assuming you have written such a conditional that evaluates to True, False or Null. If you need help with this, let me know and I will do my best.

Now running these two lines of code does infact change X to 25 if and only if ColConditional is True(1) and Y to 25 if and only if ColConditional is False(0)

Update tblTest set ColX = 25 where ColConditional = 1
Update tblTest set ColY = 25 where ColConditional = 0

P.S. The null case was never mentioned in the original question or any updates to the question, but as you can see, this very simple answer handles them anyway.

Set a default parameter value for a JavaScript function

From ES6/ES2015, default parameters are in the language specification.

function read_file(file, delete_after = false) {
  // Code
}

just works.

Reference: Default Parameters - MDN

Default function parameters allow formal parameters to be initialized with default values if no value or undefined is passed.

You can also simulate default named parameters via destructuring:

// the `= {}` below lets you call the function without any parameters
function myFor({ start = 5, end = 1, step = -1 } = {}) { // (A)
    // Use the variables `start`, `end` and `step` here
    ···
}

Pre ES2015,

There are a lot of ways, but this is my preferred method — it lets you pass in anything you want, including false or null. (typeof null == "object")

function foo(a, b) {
  a = typeof a !== 'undefined' ? a : 42;
  b = typeof b !== 'undefined' ? b : 'default_b';
  ...
}

Understanding lambda in python and using it to pass multiple arguments

I believe bind always tries to send an event parameter. Try:

self.entry_1.bind("<Return>", lambda event: self.calculate(self.buttonOut_1.grid_info(), 1))

You accept the parameter and never use it.

what does the __file__ variable mean/do?

When a module is loaded from a file in Python, __file__ is set to its path. You can then use that with other functions to find the directory that the file is located in.

Taking your examples one at a time:

A = os.path.join(os.path.dirname(__file__), '..')
# A is the parent directory of the directory where program resides.

B = os.path.dirname(os.path.realpath(__file__))
# B is the canonicalised (?) directory where the program resides.

C = os.path.abspath(os.path.dirname(__file__))
# C is the absolute path of the directory where the program resides.

You can see the various values returned from these here:

import os
print(__file__)
print(os.path.join(os.path.dirname(__file__), '..'))
print(os.path.dirname(os.path.realpath(__file__)))
print(os.path.abspath(os.path.dirname(__file__)))

and make sure you run it from different locations (such as ./text.py, ~/python/text.py and so forth) to see what difference that makes.


I just want to address some confusion first. __file__ is not a wildcard it is an attribute. Double underscore attributes and methods are considered to be "special" by convention and serve a special purpose.

http://docs.python.org/reference/datamodel.html shows many of the special methods and attributes, if not all of them.

In this case __file__ is an attribute of a module (a module object). In Python a .py file is a module. So import amodule will have an attribute of __file__ which means different things under difference circumstances.

Taken from the docs:

__file__ is the pathname of the file from which the module was loaded, if it was loaded from a file. The __file__ attribute is not present for C modules that are statically linked into the interpreter; for extension modules loaded dynamically from a shared library, it is the pathname of the shared library file.

In your case the module is accessing it's own __file__ attribute in the global namespace.

To see this in action try:

# file: test.py

print globals()
print __file__

And run:

python test.py

{'__builtins__': <module '__builtin__' (built-in)>, '__name__': '__main__', '__file__':
 'test_print__file__.py', '__doc__': None, '__package__': None}
test_print__file__.py

Ansible playbook shell output

Expanding on what leucos said in his answer, you can also print information with Ansible's humble debug module:

- hosts: all
  gather_facts: no
  tasks:
    - shell: ps -eo pcpu,user,args | sort -r -k1 | head -n5
      register: ps

    # Print the shell task's stdout.
    - debug: msg={{ ps.stdout }}

    # Print all contents of the shell task's output.
    - debug: var=ps

Numpy ValueError: setting an array element with a sequence. This message may appear without the existing of a sequence?

To put a sequence or another numpy array into a numpy array, Just change this line:

kOUT=np.zeros(N+1)

to:

kOUT=np.asarray([None]*(N+1))

Or:

kOUT=np.zeros((N+1), object)

python dataframe pandas drop column using int

You need to identify the columns based on their position in dataframe. For example, if you want to drop (del) column number 2,3 and 5, it will be,

df.drop(df.columns[[2,3,5]], axis = 1)

CSS: Position text in the middle of the page

Even though you've accepted an answer, I want to post this method. I use jQuery to center it vertically instead of css (although both of these methods work). Here is a fiddle, and I'll post the code here anyways.

HTML:

<h1>Hello world!</h1>

Javascript (jQuery):

$(document).ready(function(){
  $('h1').css({ 'width':'100%', 'text-align':'center' });
  var h1 = $('h1').height();
  var h = h1/2;
  var w1 = $(window).height();
  var w = w1/2;
  var m = w - h
  $('h1').css("margin-top",m + "px")
});

This takes the height of the viewport, divides it by two, subtracts half the height of the h1, and sets that number to the margin-top of the h1. The beauty of this method is that it works on multiple-line h1s.

EDIT: I modified it so that it centered it every time the window is resized.

reactjs - how to set inline style of backgroundcolor?

Your quotes are in the wrong spot. Here's a simple example:

<div style={{backgroundColor: "#FF0000"}}>red</div>

How to do error logging in CodeIgniter (PHP)

More oin regards to question part 4 How do you e-mail that error to an email address? The error_log function has email destination too. http://php.net/manual/en/function.error-log.php

Agha, here I found an example that shows a usage. Send errors message via email using error_log()

error_log($this->_errorMsg, 1, ADMIN_MAIL, "Content-Type: text/html; charset=utf8\r\nFrom: ".MAIL_ERR_FROM."\r\nTo: ".ADMIN_MAIL);

My Routes are Returning a 404, How can I Fix Them?

The Main problem of route not working is there is mod_rewrite.so module in macos, linux not enabled in httpd.conf file of apache configuration, so can .htaccess to work. i have solved this by uncomment the line :

# LoadModule rewrite_module libexec/apache2/mod_rewrite.so

Remove the # from above line of httpdf.conf. Then it will works.
enjoy!

How can I connect to MySQL in Python 3 on Windows?

There are currently a few options for using Python 3 with mysql:

https://pypi.python.org/pypi/mysql-connector-python

  • Officially supported by Oracle
  • Pure python
  • A little slow
  • Not compatible with MySQLdb

https://pypi.python.org/pypi/pymysql

  • Pure python
  • Faster than mysql-connector
  • Almost completely compatible with MySQLdb, after calling pymysql.install_as_MySQLdb()

https://pypi.python.org/pypi/cymysql

  • fork of pymysql with optional C speedups

https://pypi.python.org/pypi/mysqlclient

  • Django's recommended library.
  • Friendly fork of the original MySQLdb, hopes to merge back some day
  • The fastest implementation, as it is C based.
  • The most compatible with MySQLdb, as it is a fork
  • Debian and Ubuntu use it to provide both python-mysqldb andpython3-mysqldb packages.

benchmarks here: https://github.com/methane/mysql-driver-benchmarks

How to change date format using jQuery?

var d = new Date();

var curr_date = d.getDate();

var curr_month = d.getMonth();

var curr_year = d.getFullYear();

curr_year = curr_year.toString().substr(2,2);

document.write(curr_date+"-"+curr_month+"-"+curr_year);

You can change this as your need..

Make body have 100% of the browser height

I would use this

_x000D_
_x000D_
html, body{_x000D_
      background: #E73;_x000D_
      min-height: 100%;_x000D_
      min-height: 100vh;_x000D_
      overflow: auto; // <- this is needed when you resize the screen_x000D_
    }
_x000D_
<html>_x000D_
    <body>_x000D_
    </body>_x000D_
</html>
_x000D_
_x000D_
_x000D_

The browser will use min-height: 100vh and if somehow the browser is a little older the min-height: 100% will be the fallback.

The overflow: auto is necessary if you want the body and html to expand their height when you resize the screen (to a mobile size for example)

How to do a SOAP Web Service call from Java class?

Or just use Apache CXF's wsdl2java to generate objects you can use.

It is included in the binary package you can download from their website. You can simply run a command like this:

$ ./wsdl2java -p com.mynamespace.for.the.api.objects -autoNameResolution http://www.someurl.com/DefaultWebService?wsdl

It uses the wsdl to generate objects, which you can use like this (object names are also grabbed from the wsdl, so yours will be different a little):

DefaultWebService defaultWebService = new DefaultWebService();
String res = defaultWebService.getDefaultWebServiceHttpSoap11Endpoint().login("webservice","dadsadasdasd");
System.out.println(res);

There is even a Maven plug-in which generates the sources: https://cxf.apache.org/docs/maven-cxf-codegen-plugin-wsdl-to-java.html

Note: If you generate sources using CXF and IDEA, you might want to look at this: https://stackoverflow.com/a/46812593/840315

How to solve npm install throwing fsevents warning on non-MAC OS?

Instead of using --no-optional every single time, we can just add it to npm or yarn config.

For Yarn, there is a default no-optional config, so we can just edit that:

yarn config set ignore-optional true

For npm, there is no default config set, so we can create one:

npm config set ignore-optional true

Open Cygwin at a specific folder

This is the only Cygwin64 registry solution that worked for me in Windows 8.1:

Windows Registry Editor Version 5.00

[HKEY_CLASSES_ROOT\Directory\shell\mintty]
@="Mintty from Here"
"NoWorkingDirectory"=""

[HKEY_CLASSES_ROOT\Directory\shell\mintty\command]
@="C:\\cygwin64\\bin\\mintty.exe -h always -e /usr/bin/ash -c 'cd  \"$(/usr/bin/cygpath \"%L\")\";  exec /usr/bin/bash  '"

Make sure you modify your 'C:\cygwin64' path as necessary.

How to enable curl in Wamp server

I got the same issue and this solved it for me. Perhaps this might be a fix for your problem too.

Here is the fix. Follow this link http://www.anindya.com/php-5-4-3-and-php-5-3-13-x64-64-bit-for-windows/

Go to "Fixed curl extensions" and download the extension that matches your PHP version.

Extract and copy "php_curl.dll" to the extension directory of your wamp installation. (i.e. C:\wamp\bin\php\php5.3.13\ext)

Restart Apache

Done!

Refer to: http://blog.nterms.com/2012/07/php-curl-issues-with-wamp-server-on.html

Cheers!

javascript regex for password containing at least 8 characters, 1 number, 1 upper and 1 lowercase

At least 8 = {8,}:

str.match(/^(?=.*[0-9])(?=.*[a-z])(?=.*[A-Z])([a-zA-Z0-9]{8,})$/)

How to copy a char array in C?

Well, techincally you can…

typedef struct { char xx[18]; } arr_wrap;

char array1[18] = "abcdefg";
char array2[18];

*((arr_wrap *) array2) = *((arr_wrap *) array1);

printf("%s\n", array2);     /* "abcdefg" */

but it will not look very beautiful.

…Unless you use the C preprocessor…

#define CC_MEMCPY(DESTARR, SRCARR, ARRSIZE) \
    { struct _tmparrwrap_ { char xx[ARRSIZE]; }; *((struct _tmparrwrap_ *) DESTARR) = *((struct _tmparrwrap_ *) SRCARR); }

You can then do:

char array1[18] = "abcdefg";
char array2[18];

CC_MEMCPY(array2, array1, sizeof(array1));

printf("%s\n", array2);     /* "abcdefg" */

And it will work with any data type, not just char:

int numbers1[3] = { 1, 2, 3 };
int numbers2[3];

CC_MEMCPY(numbers2, numbers1, sizeof(numbers1));

printf("%d - %d - %d\n", numbers2[0], numbers2[1], numbers2[2]);     /* "abcdefg" */

(Yes, the code above is granted to work always and it's portable)

WooCommerce: Finding the products in database

I would recommend using WordPress custom fields to store eligible postcodes for each product. add_post_meta() and update_post_meta are what you're looking for. It's not recommended to alter the default WordPress table structure. All postmetas are inserted in wp_postmeta table. You can find the corresponding products within wp_posts table.

How to identify platform/compiler from preprocessor macros?

See: http://predef.sourceforge.net/index.php

This project provides a reasonably comprehensive listing of pre-defined #defines for many operating systems, compilers, language and platform standards, and standard libraries.

integrating barcode scanner into php application?

PHP can be easily utilized for reading bar codes printed on paper documents. Connecting manual barcode reader to the computer via USB significantly extends usability of PHP (or any other web programming language) into tasks involving document and product management, like finding a book records in the database or listing all bills for a particular customer.

Following sections briefly describe process of connecting and using manual bar code reader with PHP.

The usage of bar code scanners described in this article are in the same way applicable to any web programming language, such as ASP, Python or Perl. This article uses only PHP since all tests have been done with PHP applications.

What is a bar code reader (scanner)

Bar code reader is a hardware pluggable into computer that sends decoded bar code strings into computer. The trick is to know how to catch that received string. With PHP (and any other web programming language) the string will be placed into focused input HTML element in browser. Thus to catch received bar code string, following must be done:

just before reading the bar code, proper input element, such as INPUT TEXT FIELD must be focused (mouse cursor is inside of the input field). once focused, start reading the code when the code is recognized (bar code reader usually shortly beeps), it is send to the focused input field. By default, most of bar code readers will append extra special character to decoded bar code string called CRLF (ENTER). For example, if decoded bar code is "12345AB", then computer will receive "12345ABENTER". Appended character ENTER (or CRLF) emulates pressing the key ENTER causing instant submission of the HTML form:

<form action="search.php" method="post">
    <input name="documentID" onmouseover="this.focus();" type="text">
</form>

Choosing the right bar code scanner

When choosing bar code reader, one should consider what types of bar codes will be read with it. Some bar codes allow only numbers, others will not have checksum, some bar codes are difficult to print with inkjet printers, some barcode readers have narrow reading pane and cannot read for example barcodes with length over 10 cm. Most of barcode readers support common barcodes, such as EAN8, EAN13, CODE 39, Interleaved 2/5, Code 128 etc.

For office purposes, the most suitable barcodes seem to be those supporting full range of alphanumeric characters, which might be:

  • code 39 - supports 0-9, uppercased A-Z, and few special characters (dash, comma, space, $, /, +, %, *)
  • code 128 - supports 0-9, a-z, A-Z and other extended characters

Other important things to note:

  • make sure all standard barcodes are supported, at least CODE39, CODE128, Interleaved25, EAN8, EAN13, PDF417, QRCODE.
  • use only standard USB plugin cables. RS232 interfaces are meant for industrial usage, rather than connecting to single PC.
  • the cable should be long enough, at least 1.5 m - the longer the better.
  • bar code reader plugged into computer should not require other power supply - it should power up simply by connecting to PC via USB.
  • if you also need to print bar code into generated PDF documents, you can use TCPDF open source library that supports most of common 2D bar codes.

Installing scanner drivers

Installing manual bar code reader requires installing drivers for your particular operating system and should be normally supplied with purchased bar code reader.

Once installed and ready, bar code reader turns on signal LED light. Reading the barcode starts with pressing button for reading.

Scanning the barcode - how does it work?

STEP 1 - Focused input field ready for receiving character stream from bar code scanner:

step 1

STEP 2 - Received barcode string from bar code scanner is immediatelly submitted for search into database, which creates nice "automated" effect:

step 2

STEP 3 - Results returned after searching the database with submitted bar code:

step 3

Conclusion

It seems, that utilization of PHP (and actually any web programming language) for scanning the bar codes has been quite overlooked so far. However, with natural support of emulated keypress (ENTER/CRLF) it is very easy to automate collecting & processing recognized bar code strings via simple HTML (GUI) fomular.

The key is to understand, that recognized bar code string is instantly sent to the focused HTML element, such as INPUT text field with appended trailing character ASCII 13 (=ENTER/CRLF, configurable option), which instantly sends input text field with populated received barcode as a HTML formular to any other script for further processing.

Reference: http://www.synet.sk/php/en/280-barcode-reader-scanner-in-php

Hope this helps you :)

Get the last inserted row ID (with SQL statement)

You can use:

SELECT IDENT_CURRENT('tablename')

to access the latest identity for a perticular table.

e.g. Considering following code:

INSERT INTO dbo.MyTable(columns....) VALUES(..........)

INSERT INTO dbo.YourTable(columns....) VALUES(..........)

SELECT IDENT_CURRENT('MyTable')

SELECT IDENT_CURRENT('YourTable')

This would yield to correct value for corresponding tables.

It returns the last IDENTITY value produced in a table, regardless of the connection that created the value, and regardless of the scope of the statement that produced the value.

IDENT_CURRENT is not limited by scope and session; it is limited to a specified table. IDENT_CURRENT returns the identity value generated for a specific table in any session and any scope.

How can I check if a MySQL table exists with PHP?

The cleanest way to achieve this in PHP is to simply use DESCRIBE statement.

if ( mysql_query( "DESCRIBE `my_table`" ) ) {
    // my_table exists
}

I'm not sure why others are posting complicated queries for a such a straight forward problem.

Update

Using PDO

// assuming you have already setup $pdo
$sh = $pdo->prepare( "DESCRIBE `my_table`");
if ( $sh->execute() ) {
    // my_table exists
} else {
    // my_table does not exist    
}

Finding the direction of scrolling in a UIScrollView?

- (void)scrollViewWillEndDragging:(UIScrollView *)scrollView withVelocity:(CGPoint)velocity targetContentOffset:(inout CGPoint *)targetContentOffset {
NSLog(@"px %f py %f",velocity.x,velocity.y);}

Use this delegate method of scrollview.

If y co-ordinate of velocity is +ve scroll view scrolls downwards and if it is -ve scrollview scrolls upwards. Similarly left and right scroll can be detected using x co-ordinate.

JavaScript Loading Screen while page loads

If in your site you have ajax calls loading some data, and this is the reason the page is loading slow, the best solution I found is with

$(document).ajaxStop(function(){
    alert("All AJAX requests completed");
});

https://jsfiddle.net/44t5a8zm/ - here you can add some ajax calls and test it.

Appending to 2D lists in Python

You haven't created three different empty lists. You've created one empty list, and then created a new list with three references to that same empty list. To fix the problem use this code instead:

listy = [[] for i in range(3)]

Running your example code now gives the result you probably expected:

>>> listy = [[] for i in range(3)]
>>> listy[1] = [1,2]
>>> listy
[[], [1, 2], []]
>>> listy[1].append(3)
>>> listy
[[], [1, 2, 3], []]
>>> listy[2].append(1)
>>> listy
[[], [1, 2, 3], [1]]

Echo a blank (empty) line to the console from a Windows batch file

Note: Though my original answer attracted several upvotes, I decided that I could do much better. You can find my original (simplistic and misguided) answer in the edit history.

If Microsoft had the intent of providing a means of outputting a blank line from cmd.exe, Microsoft surely would have documented such a simple operation. It is this omission that motivated me to ask this question.

So, because a means for outputting a blank line from cmd.exe is not documented, arguably one should consider any suggestion for how to accomplish this to be a hack. That means that there is no known method for outputting a blank line from cmd.exe that is guaranteed to work (or work efficiently) in all situations.

With that in mind, here is a discussion of methods that have been recommended for outputting a blank line from cmd.exe. All recommendations are based on variations of the echo command.


echo.

While this will work in many if not most situations, it should be avoided because it is slower than its alternatives and actually can fail (see here, here, and here). Specifically, cmd.exe first searches for a file named echo and tries to start it. If a file named echo happens to exist in the current working directory, echo. will fail with:

'echo.' is not recognized as an internal or external command,
operable program or batch file.

echo:
echo\

At the end of this answer, the author argues that these commands can be slow, for instance if they are executed from a network drive location. A specific reason for the potential slowness is not given. But one can infer that it may have something to do with accessing the file system. (Perhaps because : and \ have special meaning in a Windows file system path?)

However, some may consider these to be safe options since : and \ cannot appear in a file name. For that or another reason, echo: is recommended by SS64.com here.


echo(
echo+
echo,
echo/
echo;
echo=
echo[
echo]

This lengthy discussion includes what I believe to be all of these. Several of these options are recommended in this SO answer as well. Within the cited discussion, this post ends with what appears to be a recommendation for echo( and echo:.

My question at the top of this page does not specify a version of Windows. My experimentation on Windows 10 indicates that all of these produce a blank line, regardless of whether files named echo, echo+, echo,, ..., echo] exist in the current working directory. (Note that my question predates the release of Windows 10. So I concede the possibility that older versions of Windows may behave differently.)

In this answer, @jeb asserts that echo( always works. To me, @jeb's answer implies that other options are less reliable but does not provide any detail as to why that might be. Note that @jeb contributed much valuable content to other references I have cited in this answer.


Conclusion: Do not use echo.. Of the many other options I encountered in the sources I have cited, the support for these two appears most authoritative:

echo(
echo:

But I have not found any strong evidence that the use of either of these will always be trouble-free.


Example Usage:

@echo off
echo Here is the first line.
echo(
echo There is a blank line above this line.

Expected output:

Here is the first line.

There is a blank line above this line.

What is java pojo class, java bean, normal class?

POJO stands for Plain Old Java Object, and would be used to describe the same things as a "Normal Class" whereas a JavaBean follows a set of rules. Most commonly Beans use getters and setters to protect their member variables, which are typically set to private and have a no-argument public constructor. Wikipedia has a pretty good rundown of JavaBeans: http://en.wikipedia.org/wiki/JavaBeans

POJO is usually used to describe a class that doesn't need to be a subclass of anything, or implement specific interfaces, or follow a specific pattern.

pycharm running way slow

Well Lorenz Lo Sauer already have a good question for this. but if you want to resolve this problem through the Pycharm Tuning (without turning off Pycharm code inspection). you can tuning the heap size as you need. since I prefer to use increasing Heap Size solution for slow running Pycharm Application.

You can tune up Heap Size by editing pycharm.exe.vmoptions file. and pycharm64.exe.vmoptions for 64bit application. and then edit -Xmx and -Xms value on it.

So I allocate 2048m for xmx and xms value (which is 2GB) for my Pycharm Heap Size. Here it is My Configuration. I have 8GB memory so I had set it up with this setting:

-server
-Xms2048m
-Xmx2048m
-XX:MaxPermSize=2048m
-XX:ReservedCodeCacheSize=2048m

save the setting, and restart IDE. And I enable "Show memory indicator" in settings->Appearance & Behavior->Appearance. to see it in action :

Pycharm slow, slow typing, increase Pycharm Heap Size

and Pycharm is quick and running fine now.

Reference : https://www.jetbrains.com/help/pycharm/2017.1/tuning-pycharm.html#d176794e266

Pass multiple arguments into std::thread

If you're getting this, you may have forgotten to put #include <thread> at the beginning of your file. OP's signature seems like it should work.

Case-insensitive string comparison in C++

My first thought for a non-unicode version was to do something like this:

bool caseInsensitiveStringCompare(const string& str1, const string& str2) {
    if (str1.size() != str2.size()) {
        return false;
    }
    for (string::const_iterator c1 = str1.begin(), c2 = str2.begin(); c1 != str1.end(); ++c1, ++c2) {
        if (tolower(static_cast<unsigned char>(*c1)) != tolower(static_cast<unsigned char>(*c2))) {
            return false;
        }
    }
    return true;
}

Number of regex matches

#An example for counting matched groups
import re

pattern = re.compile(r'(\w+).(\d+).(\w+).(\w+)', re.IGNORECASE)
search_str = "My 11 Char String"

res = re.match(pattern, search_str)
print(len(res.groups())) # len = 4  
print (res.group(1) ) #My
print (res.group(2) ) #11
print (res.group(3) ) #Char
print (res.group(4) ) #String

Getting the source of a specific image element with jQuery

var src = $('img.conversation_img[alt="example"]').attr('src');

If you have multiple matching elements only the src of the first one will be returned.

Can I use GDB to debug a running process?

Yes you can. Assume a process foo is running...

ps -elf | grep foo

look for the PID number

gdb -a {PID number}

What's the easiest way to install a missing Perl module?

Sometimes you can use the yum search foo to search the relative perl module, then use yum install xxx to install.

How do you run a .bat file from PHP?

For anyone who needs to run a program in the background "without PHP waiting for it to finish" do this:

 pclose(popen("start /B ".$cmd, "r")); 

where $cmd is the string command for the program that you need to run (e.g. $cmd can equal notepad.exe or node Path\to\server.js).

Source: https://www.php.net/manual/en/function.exec.php (see Arno van den Brink's note in the section titled "User Contributed Notes").

How to change the link color in a specific class for a div CSS

It can be something like this:

a.register:link { color:#FFF; text-decoration:none; font-weight:normal; }
a.register:visited { color: #FFF; text-decoration:none; font-weight:normal; }
a.register:hover { color: #FFF; text-decoration:underline; font-weight:normal; }
a.register:active { color: #FFF; text-decoration:none; font-weight:normal; }

HTML Input Box - Disable

<input type="text" disabled="disabled" />

See the W3C HTML Specification on the input tag for more information.

Switch between two frames in tkinter

One way is to stack the frames on top of each other, then you can simply raise one above the other in the stacking order. The one on top will be the one that is visible. This works best if all the frames are the same size, but with a little work you can get it to work with any sized frames.

Note: for this to work, all of the widgets for a page must have that page (ie: self) or a descendant as a parent (or master, depending on the terminology you prefer).

Here's a bit of a contrived example to show you the general concept:

try:
    import tkinter as tk                # python 3
    from tkinter import font as tkfont  # python 3
except ImportError:
    import Tkinter as tk     # python 2
    import tkFont as tkfont  # python 2

class SampleApp(tk.Tk):

    def __init__(self, *args, **kwargs):
        tk.Tk.__init__(self, *args, **kwargs)

        self.title_font = tkfont.Font(family='Helvetica', size=18, weight="bold", slant="italic")

        # the container is where we'll stack a bunch of frames
        # on top of each other, then the one we want visible
        # will be raised above the others
        container = tk.Frame(self)
        container.pack(side="top", fill="both", expand=True)
        container.grid_rowconfigure(0, weight=1)
        container.grid_columnconfigure(0, weight=1)

        self.frames = {}
        for F in (StartPage, PageOne, PageTwo):
            page_name = F.__name__
            frame = F(parent=container, controller=self)
            self.frames[page_name] = frame

            # put all of the pages in the same location;
            # the one on the top of the stacking order
            # will be the one that is visible.
            frame.grid(row=0, column=0, sticky="nsew")

        self.show_frame("StartPage")

    def show_frame(self, page_name):
        '''Show a frame for the given page name'''
        frame = self.frames[page_name]
        frame.tkraise()


class StartPage(tk.Frame):

    def __init__(self, parent, controller):
        tk.Frame.__init__(self, parent)
        self.controller = controller
        label = tk.Label(self, text="This is the start page", font=controller.title_font)
        label.pack(side="top", fill="x", pady=10)

        button1 = tk.Button(self, text="Go to Page One",
                            command=lambda: controller.show_frame("PageOne"))
        button2 = tk.Button(self, text="Go to Page Two",
                            command=lambda: controller.show_frame("PageTwo"))
        button1.pack()
        button2.pack()


class PageOne(tk.Frame):

    def __init__(self, parent, controller):
        tk.Frame.__init__(self, parent)
        self.controller = controller
        label = tk.Label(self, text="This is page 1", font=controller.title_font)
        label.pack(side="top", fill="x", pady=10)
        button = tk.Button(self, text="Go to the start page",
                           command=lambda: controller.show_frame("StartPage"))
        button.pack()


class PageTwo(tk.Frame):

    def __init__(self, parent, controller):
        tk.Frame.__init__(self, parent)
        self.controller = controller
        label = tk.Label(self, text="This is page 2", font=controller.title_font)
        label.pack(side="top", fill="x", pady=10)
        button = tk.Button(self, text="Go to the start page",
                           command=lambda: controller.show_frame("StartPage"))
        button.pack()


if __name__ == "__main__":
    app = SampleApp()
    app.mainloop()

start page page 1 page 2

If you find the concept of creating instance in a class confusing, or if different pages need different arguments during construction, you can explicitly call each class separately. The loop serves mainly to illustrate the point that each class is identical.

For example, to create the classes individually you can remove the loop (for F in (StartPage, ...) with this:

self.frames["StartPage"] = StartPage(parent=container, controller=self)
self.frames["PageOne"] = PageOne(parent=container, controller=self)
self.frames["PageTwo"] = PageTwo(parent=container, controller=self)

self.frames["StartPage"].grid(row=0, column=0, sticky="nsew")
self.frames["PageOne"].grid(row=0, column=0, sticky="nsew")
self.frames["PageTwo"].grid(row=0, column=0, sticky="nsew")

Over time people have asked other questions using this code (or an online tutorial that copied this code) as a starting point. You might want to read the answers to these questions:

Drop columns whose name contains a specific string from pandas DataFrame

This can be done neatly in one line with:

df = df.drop(df.filter(regex='Test').columns, axis=1)

Clear MySQL query cache without restarting server

according the documentation, this should do it...

RESET QUERY CACHE 

How to use Tomcat 8.5.x and TomEE 7.x with Eclipse?

I had similar issues with Eclipse Kepler v3.8 I had tomcat v8.5.37 installed. I couldn't see Apache v8.5 as an option. By skimming through StackOverflow I found Apache v9.0 is available on Eclipse Neon. Cool thing is you don't have to change your eclipse version. In your current Eclipse. Download WTP(Web Tools Package) by following the steps:

Step 1: Help >>> Install New Software. Copy this link in the Work with: http://download.eclipse.org/webtools/repository/neon

Step 2: Select JST Server Adapters and JST Server Adapters Extensions from the first package you see. Install those.

Step 3: Windows >>> Preferences >>> Server >>> Runtime Environments >>> Add..

You'll see Apache v9.0 there! It works!

href="tel:" and mobile numbers

When dialing a number within the country you are in, you still need to dial the national trunk number before the rest of the number. For example, in Australia one would dial:

   0 - trunk prefix
   2 - Area code for New South Wales
6555 - STD code for a specific telephone exchange
1234 - Telephone Exchange specific extension.

For a mobile phone this becomes

   0 -      trunk prefix
   4 -      Area code for a mobile telephone
1234 5678 - Mobile telephone number

Now, when I want to dial via the international trunk, you need to drop the trunk prefix and replace it with the international dialing prefix

   + -      Short hand for the country trunk number
  61 -      Country code for Australia
   4 -      Area code for a mobile telephone
1234 5678 - Mobile telephone number

This is why you often find that the first digit of a telephone number is dropped when dialling internationally, even when using international prefixing to dial within the same country.

So as per the trunk prefix for Germany drop the 0 and add the +49 for Germany's international calling code (for example) giving:

_x000D_
_x000D_
<a href="tel:+496170961709" class="Blondie">_x000D_
    Call me, call me any, anytime_x000D_
      <b>Call me (call me) I'll arrive</b>_x000D_
        When you're ready we can share the wine!_x000D_
</a>
_x000D_
_x000D_
_x000D_

MySQL : transaction within a stored procedure

This is just an explanation not addressed in other answers

At least in recent versions of Mysql, your first query is not committed.

If you query it under the same session you will see the changes, but if you query it from a different session, the changes are not there, they are not committed.

What's going on?

When you open a transaction, and a query inside it fails, the transaction keeps open, it does not commit nor rollback the changes.

So BE CAREFUL, any table/row that was locked with a previous query likeSELECT ... FOR SHARE/UPDATE, UPDATE, INSERT or any other locking-query, keeps locked until that session is killed (and executes a rollback), or until a subsequent query commits it explicitly (COMMIT) or implicitly, thus making the partial changes permanent (which might happen hours later, while the transaction was in a waiting state).

That's why the solution involves declaring handlers to immediately ROLLBACK when an error happens.

Extra

Inside the handler you can also re-raise the error using RESIGNAL, otherwise the stored procedure executes "Successfully"

BEGIN
    DECLARE EXIT HANDLER FOR SQLEXCEPTION 
        BEGIN
            ROLLBACK;
            RESIGNAL;
        END;

    START TRANSACTION;
        #.. Query 1 ..
        #.. Query 2 ..
        #.. Query 3 ..
    COMMIT;
END

Can I pass parameters in computed properties in Vue.Js

Yes methods are there for using params. Like answers stated above, in your example it's best to use methods since execution is very light.

Only for reference, in a situation where the method is complex and cost is high, you can cache the results like so:

data() {
    return {
        fullNameCache:{}
    };
}

methods: {
    fullName(salut) {
        if (!this.fullNameCache[salut]) {
            this.fullNameCache[salut] = salut + ' ' + this.firstName + ' ' + this.lastName;
        }
        return this.fullNameCache[salut];
    }
}

note: When using this, watchout for memory if dealing with thousands

Difference between == and ===

There are subtleties with Swifts === that go beyond mere pointer arithmetics. While in Objective-C you were able to compare any two pointers (i.e. NSObject *) with == this is no longer true in Swift since types play a much greater role during compilation.

A Playground will give you

1 === 2                    // false
1 === 1                    // true
let one = 1                // 1
1 === one                  // compile error: Type 'Int' does not conform to protocol 'AnyObject'
1 === (one as AnyObject)   // true (surprisingly (to me at least))

With strings we will have to get used to this:

var st = "123"                                 // "123"
var ns = (st as NSString)                      // "123"
st == ns                                       // true, content equality
st === ns                                      // compile error
ns === (st as NSString)                        // false, new struct
ns === (st as AnyObject)                       // false, new struct
(st as NSString) === (st as NSString)          // false, new structs, bridging is not "free" (as in "lunch")
NSString(string:st) === NSString(string:st)    // false, new structs
var st1 = NSString(string:st)                  // "123"
var st2 = st1                                  // "123"
st1 === st2                                    // true
var st3 = (st as NSString)                     // "123"
st1 === st3                                    // false
(st as AnyObject) === (st as AnyObject)        // false

but then you can also have fun as follows:

var st4 = st             // "123"
st4 == st                // true
st4 += "5"               // "1235"
st4 == st                // false, not quite a reference, copy on write semantics

I am sure you can think of a lot more funny cases :-)

Update for Swift 3 (as suggested by the comment from Jakub Truhlár)

1===2                                    // Compiler error: binary operator '===' cannot be applied to two 'Int' operands
(1 as AnyObject) === (2 as AnyObject)    // false
let two = 2
(2 as AnyObject) === (two as AnyObject)  // false (rather unpleasant)
(2 as AnyObject) === (2 as AnyObject)    // false (this makes it clear that there are new objects being generated)

This looks a little more consistent with Type 'Int' does not conform to protocol 'AnyObject', however we then get

type(of:(1 as AnyObject))                // _SwiftTypePreservingNSNumber.Type

but the explicit conversion makes clear that there might be something going on. On the String-side of things NSString will still be available as long as we import Cocoa. Then we will have

var st = "123"                                 // "123"
var ns = (st as NSString)                      // "123"
st == ns                                       // Compile error with Fixit: 'NSString' is not implicitly convertible to 'String'; did you mean to use 'as' to explicitly convert?
st == ns as String                             // true, content equality
st === ns                                      // compile error: binary operator '===' cannot be applied to operands of type 'String' and 'NSString'
ns === (st as NSString)                        // false, new struct
ns === (st as AnyObject)                       // false, new struct
(st as NSString) === (st as NSString)          // false, new structs, bridging is not "free" (as in "lunch")
NSString(string:st) === NSString(string:st)    // false, new objects
var st1 = NSString(string:st)                  // "123"
var st2 = st1                                  // "123"
st1 === st2                                    // true
var st3 = (st as NSString)                     // "123"
st1 === st3                                    // false
(st as AnyObject) === (st as AnyObject)        // false

It is still confusing to have two String classes, but dropping the implicit conversion will probably make it a little more palpable.

Cannot find module '../build/Release/bson'] code: 'MODULE_NOT_FOUND' } js-bson: Failed to load c++ bson extension, using pure JS version

First copy bson.js code from browser_build folder

second create new file bson.js and paste code

third save the new file near to in index.js.

How to get row count using ResultSet in Java?

your sql Statement creating code may be like

statement = connection.createStatement();

To solve "com.microsoft.sqlserver.jdbc.SQLServerException: The requested operation is not supported on forward only result sets" exception change above code with

statement = connection.createStatement(
    ResultSet.TYPE_SCROLL_INSENSITIVE, 
    ResultSet.CONCUR_READ_ONLY);

After above change you can use

int size = 0;
try {
    resultSet.last();
    size = resultSet.getRow();
    resultSet.beforeFirst();
}
catch(Exception ex) {
    return 0;
}
return size;

to get row count

Should I URL-encode POST data?

@DougW has clearly answered this question, but I still like to add some codes here to explain Doug's points. (And correct errors in the code above)

Solution 1: URL-encode the POST data with a content-type header :application/x-www-form-urlencoded .

Note: you do not need to urlencode $_POST[] fields one by one, http_build_query() function can do the urlencoding job nicely.

$fields = array(
    'mediaupload'=>$file_field,
    'username'=>$_POST["username"],
    'password'=>$_POST["password"],
    'latitude'=>$_POST["latitude"],
    'longitude'=>$_POST["longitude"],
    'datetime'=>$_POST["datetime"],
    'category'=>$_POST["category"],
    'metacategory'=>$_POST["metacategory"],
    'caption'=>$_POST["description"]
);

$fields_string = http_build_query($fields);

$ch = curl_init();
curl_setopt($ch, CURLOPT_URL,$url);
curl_setopt($ch, CURLOPT_POST,1);
curl_setopt($ch, CURLOPT_POSTFIELDS,$fields_string);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
$response = curl_exec($ch);

Solution 2: Pass the array directly as the post data without URL-encoding, while the Content-Type header will be set to multipart/form-data.

$fields = array(
        'mediaupload'=>$file_field,
        'username'=>$_POST["username"],
        'password'=>$_POST["password"],
        'latitude'=>$_POST["latitude"],
        'longitude'=>$_POST["longitude"],
        'datetime'=>$_POST["datetime"],
        'category'=>$_POST["category"],
        'metacategory'=>$_POST["metacategory"],
        'caption'=>$_POST["description"]
    );

    $ch = curl_init();
    curl_setopt($ch, CURLOPT_URL,$url);
    curl_setopt($ch, CURLOPT_POST,1);
    curl_setopt($ch, CURLOPT_POSTFIELDS,$fields);
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
    $response = curl_exec($ch);

Both code snippets work, but using different HTTP headers and bodies.

Android ListView with different layouts for each row

If we need to show different type of view in list-view then its good to use getViewTypeCount() and getItemViewType() in adapter instead of toggling a view VIEW.GONE and VIEW.VISIBLE can be very expensive task inside getView() which will affect the list scroll.

Please check this one for use of getViewTypeCount() and getItemViewType() in Adapter.

Link : the-use-of-getviewtypecount

What is the significance of 1/1/1753 in SQL Server?

1752 was the year of Britain switching from the Julian to the Gregorian calendar. I believe two weeks in September 1752 never happened as a result, which has implications for dates in that general area.

An explanation: http://uneasysilence.com/archive/2007/08/12008/ (Internet Archive version)

How to input a path with a white space?

If the path in Ubuntu is "/home/ec2-user/Name of Directory", then do this:

1) Java's build.properties file:

build_path='/home/ec2-user/Name\\ of\\ Directory'

Where ~/ is equal to /home/ec2-user

2) Jenkinsfile:

build_path=buildprops['build_path']
echo "Build path= ${build_path}"
sh "cd ${build_path}"

Correct way to handle conditional styling in React

 <div style={{ visibility: this.state.driverDetails.firstName != undefined? 'visible': 'hidden'}}></div>

Checkout the above code. That will do the trick.

Send form data using ajax

you can use serialize method of jquery to get form values. Try like this

<form action="target.php" method="post" >
<input type="text" name="lname" />
<input type="text" name="fname" />
<input type="buttom" name ="send" onclick="return f(this.form) " >
</form>

function f( form ){
    var formData = $(form).serialize();
    att=form.attr("action") ;
    $.post(att, formData).done(function(data){
        alert(data);
    });
    return true;
}

Style jQuery autocomplete in a Bootstrap input field

I don't know if you fixed it, but I did had the same issue, finally it was a dumb thing, I had:

<script src="jquery-ui/jquery-ui.min.css" rel="stylesheet">

but it should be:

<link href="jquery-ui/jquery-ui.min.css" rel="stylesheet">

Just change <scrip> to <link> and src to href

Bypass invalid SSL certificate errors when calling web services in .Net

ServicePointManager.ServerCertificateValidationCallback +=
            (mender, certificate, chain, sslPolicyErrors) => true;

will bypass invaild ssl . Write it to your web service constructor.

Simplest way to detect keypresses in javascript

Use event.key and modern JS!

No number codes anymore. You can use "Enter", "ArrowLeft", "r", or any key name directly, making your code far more readable.

NOTE: The old alternatives (.keyCode and .which) are Deprecated.

document.addEventListener("keypress", function onEvent(event) {
    if (event.key === "ArrowLeft") {
        // Move Left
    }
    else if (event.key === "Enter") {
        // Open Menu...
    }
});

Mozilla Docs

Supported Browsers

Numpy - add row to array

You can also do this:

newrow = [1,2,3]
A = numpy.concatenate((A,newrow))

How to prevent line-break in a column of a table cell (not a single cell)?

<td style="white-space: nowrap">

The nowrap attribute I believe is deprecated. The above is the preferred way.

Runnable with a parameter?

Since Java 8, the best answer is to use Consumer<T>:

https://docs.oracle.com/javase/8/docs/api/java/util/function/Consumer.html

It's one of the functional interfaces, which means you can call it as a lambda expression:

void doSomething(Consumer<String> something) {
    something.accept("hello!");
}

...

doSomething( (something) -> System.out.println(something) )

...

Maven: The packaging for this project did not assign a file to the build artifact

I don't know if this is the answer or not but it might lead you in the right direction...

The command install:install is actually a goal on the maven-install-plugin. This is different than the install maven lifecycle phase.

Maven lifecycle phases are steps in a build which certain plugins can bind themselves to. Many different goals from different plugins may execute when you invoke a single lifecycle phase.

What this boils down to is the command...

mvn clean install

is different from...

mvn clean install:install

The former will run all goals in every cycle leading up to and including the install (like compile, package, test, etc.). The latter will not even compile or package your code, it will just run that one goal. This kinda makes sense, looking at the exception; it talks about:

StarTeamCollisionUtil: The packaging for this project did not assign a file to the build artifact

Try the former and your error might just go away!

What are the use cases for selecting CHAR over VARCHAR in SQL?

Many people have pointed out that if you know the exact length of the value using CHAR has some benefits. But while storing US states as CHAR(2) is great today, when you get the message from sales that 'We have just made our first sale to Australia', you are in a world of pain. I always send to overestimate how long I think fields will need to be rather than making an 'exact' guess to cover for future events. VARCHAR will give me more flexibility in this area.

When does Java's Thread.sleep throw InterruptedException?

If an InterruptedException is thrown it means that something wants to interrupt (usually terminate) that thread. This is triggered by a call to the threads interrupt() method. The wait method detects that and throws an InterruptedException so the catch code can handle the request for termination immediately and does not have to wait till the specified time is up.

If you use it in a single-threaded app (and also in some multi-threaded apps), that exception will never be triggered. Ignoring it by having an empty catch clause I would not recommend. The throwing of the InterruptedException clears the interrupted state of the thread, so if not handled properly that info gets lost. Therefore I would propose to run:

} catch (InterruptedException e) {
  Thread.currentThread().interrupt();
  // code for stopping current task so thread stops
}

Which sets that state again. After that, finish execution. This would be correct behaviour, even tough never used.

What might be better is to add this:

} catch (InterruptedException e) {
  throw new RuntimeException("Unexpected interrupt", e);
}

...statement to the catch block. That basically means that it must never happen. So if the code is re-used in an environment where it might happen it will complain about it.

Get Today's date in Java at midnight time

    Calendar c = new GregorianCalendar();
    c.set(Calendar.HOUR_OF_DAY, 0); //anything 0 - 23
    c.set(Calendar.MINUTE, 0);
    c.set(Calendar.SECOND, 0);
    Date d1 = c.getTime(); //the midnight, that's the first second of the day.

should be Fri Mar 09 00:00:00 IST 2012

How to get year, month, day, hours, minutes, seconds and milliseconds of the current moment in Java?

    // Java 8
    System.out.println(LocalDateTime.now().getYear());       // 2015
    System.out.println(LocalDateTime.now().getMonth());      // SEPTEMBER
    System.out.println(LocalDateTime.now().getDayOfMonth()); // 29
    System.out.println(LocalDateTime.now().getHour());       // 7
    System.out.println(LocalDateTime.now().getMinute());     // 36
    System.out.println(LocalDateTime.now().getSecond());     // 51
    System.out.println(LocalDateTime.now().get(ChronoField.MILLI_OF_SECOND)); // 100

    // Calendar
    System.out.println(Calendar.getInstance().get(Calendar.YEAR));         // 2015
    System.out.println(Calendar.getInstance().get(Calendar.MONTH ) + 1);   // 9
    System.out.println(Calendar.getInstance().get(Calendar.DAY_OF_MONTH)); // 29
    System.out.println(Calendar.getInstance().get(Calendar.HOUR_OF_DAY));  // 7
    System.out.println(Calendar.getInstance().get(Calendar.MINUTE));       // 35
    System.out.println(Calendar.getInstance().get(Calendar.SECOND));       // 32
    System.out.println(Calendar.getInstance().get(Calendar.MILLISECOND));  // 481

    // Joda Time
    System.out.println(new DateTime().getYear());           // 2015
    System.out.println(new DateTime().getMonthOfYear());    // 9
    System.out.println(new DateTime().getDayOfMonth());     // 29
    System.out.println(new DateTime().getHourOfDay());      // 7
    System.out.println(new DateTime().getMinuteOfHour());   // 19
    System.out.println(new DateTime().getSecondOfMinute()); // 16
    System.out.println(new DateTime().getMillisOfSecond()); // 174

    // Formatted
    // 2015-09-28 17:50:25.756
    System.out.println(new Timestamp(System.currentTimeMillis()));

    // 2015-09-28T17:50:25.772
    System.out.println(new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss.SSS", Locale.ENGLISH).format(new Date()));

    // Java 8
    // 2015-09-28T17:50:25.810
    System.out.println(LocalDateTime.now());

    // joda time
    // 2015-09-28 17:50:25.839
    System.out.println(DateTimeFormat.forPattern("YYYY-MM-dd HH:mm:ss.SSS").print(new org.joda.time.DateTime()));

Split a python list into other "sublists" i.e smaller lists

I'd say

chunks = [data[x:x+100] for x in range(0, len(data), 100)]

If you are using python 2.x instead of 3.x, you can be more memory-efficient by using xrange(), changing the above code to:

chunks = [data[x:x+100] for x in xrange(0, len(data), 100)]

Edittext change border color with shape.xml

This is work for me: Drwable->New->Drawable Resource File->create xml file

  <?xml version="1.0" encoding="utf-8"?>
    <shape xmlns:android="http://schemas.android.com/apk/res/android">
        xmlns:android="http://schemas.android.com/apk/res/android"
        android:shape="rectangle">
        <solid android:color="#e0e0e0" />
        <stroke android:width="2dp" android:color="#a4b0ba" />
    </shape>

How do I force Robocopy to overwrite files?

I did this for a home folder where all the folders are on the desktops of the corresponding users, reachable through a shortcut which did not have the appropriate permissions, so that users couldn't see it even if it was there. So I used Robocopy with the parameter to overwrite the file with the right settings:

FOR /F "tokens=*" %G IN ('dir /b') DO robocopy  "\\server02\Folder with shortcut" "\\server02\home\%G\Desktop" /S /A /V /log+:C:\RobocopyShortcut.txt /XF *.url *.mp3 *.hta *.htm *.mht *.js *.IE5 *.css *.temp *.html *.svg *.ocx *.3gp *.opus *.zzzzz *.avi *.bin *.cab *.mp4 *.mov *.mkv *.flv *.tiff *.tif *.asf *.webm *.exe *.dll *.dl_ *.oc_ *.ex_ *.sy_ *.sys *.msi *.inf *.ini *.bmp *.png *.gif *.jpeg *.jpg *.mpg *.db *.wav *.wma *.wmv *.mpeg *.tmp *.old *.vbs *.log *.bat *.cmd *.zip /SEC /IT /ZB /R:0

As you see there are many file types which I set to ignore (just in case), just set them for your needs or your case scenario.

It was tested on Windows Server 2012, and every switch is documented on Microsoft's sites and others.

How to downgrade tensorflow, multiple versions possible?

I discovered the joy of anaconda: https://www.continuum.io/downloads

C:> conda create -n tensorflow1.1 python=3.5
C:> activate tensorflow1.1
(tensorflow1.1) 
C:> pip install --ignore-installed --upgrade https://storage.googleapis.com/tensorflow/windows/gpu/tensorflow_gpu-1.1.0-cp35-cp35m-win_amd64.whl

voila, a virtual environment is created.

Difference between opening a file in binary vs text

The link you gave does actually describe the differences, but it's buried at the bottom of the page:

http://www.cplusplus.com/reference/cstdio/fopen/

Text files are files containing sequences of lines of text. Depending on the environment where the application runs, some special character conversion may occur in input/output operations in text mode to adapt them to a system-specific text file format. Although on some environments no conversions occur and both text files and binary files are treated the same way, using the appropriate mode improves portability.

The conversion could be to normalize \r\n to \n (or vice-versa), or maybe ignoring characters beyond 0x7F (a-la 'text mode' in FTP). Personally I'd open everything in binary-mode and use a good text-encoding library for dealing with text.

Datepicker: How to popup datepicker when click on edittext

Couldn't get anyone of these working so will add my one just in-case it helps.

public class MyEditTextDatePicker  implements OnClickListener, OnDateSetListener {   
EditText _editText;
private int _day;
private int _month;
private int _birthYear;
private Context _context;

public MyEditTextDatePicker(Context context, int editTextViewID)
{       
    Activity act = (Activity)context;
    this._editText = (EditText)act.findViewById(editTextViewID);
    this._editText.setOnClickListener(this);
    this._context = context;
}

@Override
public void onDateSet(DatePicker view, int year, int monthOfYear, int dayOfMonth) {
    _birthYear = year;
    _month = monthOfYear;
    _day = dayOfMonth;
    updateDisplay();
}
@Override
public void onClick(View v) {
    Calendar calendar = Calendar.getInstance(TimeZone.getDefault());

    DatePickerDialog dialog = new DatePickerDialog(_context, this,
            calendar.get(Calendar.YEAR), calendar.get(Calendar.MONTH),
            calendar.get(Calendar.DAY_OF_MONTH));
    dialog.show();

}

// updates the date in the birth date EditText
private void updateDisplay() {

    _editText.setText(new StringBuilder()
    // Month is 0 based so add 1
    .append(_day).append("/").append(_month + 1).append("/").append(_birthYear).append(" "));
}
}

Also something that isn't mentioned in the others. Make sure you put the following on EditText xml.

android:focusable="false"

Otherwise like in my case the Keyboard will keep popping up. Hope this helps someone

How do I find the current machine's full hostname in C (hostname and domain information)?

The easy way, try uname()

If that does not work, use gethostname() then gethostbyname() and finally gethostbyaddr()

The h_name of hostent{} should be your FQDN

Why does corrcoef return a matrix?

Consider using matplotlib.cbook pieces

for example:

import matplotlib.cbook as cbook
segments = cbook.pieces(np.arange(20), 3)
for s in segments:
     print s

What is a JavaBean exactly?

Spring @Bean annotation indicates that a method produces a bean to be managed by the Spring container.

More reference: https://www.concretepage.com/spring-5/spring-bean-annotation

Ruby class instance variable vs. class variable

Official Ruby FAQ: What is the difference between class variables and class instance variables?

The main difference is the behavior concerning inheritance: class variables are shared between a class and all its subclasses, while class instance variables only belong to one specific class.

Class variables in some way can be seen as global variables within the context of an inheritance hierarchy, with all the problems that come with global variables. For instance, a class variable might (accidentally) be reassigned by any of its subclasses, affecting all other classes:

class Woof

  @@sound = "woof"

  def self.sound
    @@sound
  end
end

Woof.sound  # => "woof"

class LoudWoof < Woof
  @@sound = "WOOF"
end

LoudWoof.sound  # => "WOOF"
Woof.sound      # => "WOOF" (!)

Or, an ancestor class might later be reopened and changed, with possibly surprising effects:

class Foo

  @@var = "foo"

  def self.var
    @@var
  end
end

Foo.var  # => "foo" (as expected)

class Object
  @@var = "object"
end

Foo.var  # => "object" (!)

So, unless you exactly know what you are doing and explicitly need this kind of behavior, you better should use class instance variables.

require_once :failed to open stream: no such file or directory

It says that the file C:\wamp\www\mysite\php\includes\dbconn.inc doesn't exist, so the error is, you're missing the file.

How to get different colored lines for different plots in a single figure?

Matplot colors your plot with different colors , but incase you wanna put specific colors

    import matplotlib.pyplot as plt
    import numpy as np
            
    x = np.arange(10)
            
    plt.plot(x, x)
    plt.plot(x, 2 * x,color='blue')
    plt.plot(x, 3 * x,color='red')
    plt.plot(x, 4 * x,color='green')
    plt.show()

jQuery creating objects

May be you want this (oop in javascript)

function box(color)
{
    this.color=color;
}

var box1=new box('red');    
var box2=new box('white');    

DEMO.

For more information.

setContentView(R.layout.main); error

Step 1 : import android.*;

Step 2 : clean your project

Step 3 : Enjoy !!!

how to transfer a file through SFTP in java?

Try this code.

public void send (String fileName) {
    String SFTPHOST = "host:IP";
    int SFTPPORT = 22;
    String SFTPUSER = "username";
    String SFTPPASS = "password";
    String SFTPWORKINGDIR = "file/to/transfer";

    Session session = null;
    Channel channel = null;
    ChannelSftp channelSftp = null;
    System.out.println("preparing the host information for sftp.");

    try {
        JSch jsch = new JSch();
        session = jsch.getSession(SFTPUSER, SFTPHOST, SFTPPORT);
        session.setPassword(SFTPPASS);
        java.util.Properties config = new java.util.Properties();
        config.put("StrictHostKeyChecking", "no");
        session.setConfig(config);
        session.connect();
        System.out.println("Host connected.");
        channel = session.openChannel("sftp");
        channel.connect();
        System.out.println("sftp channel opened and connected.");
        channelSftp = (ChannelSftp) channel;
        channelSftp.cd(SFTPWORKINGDIR);
        File f = new File(fileName);
        channelSftp.put(new FileInputStream(f), f.getName());
        log.info("File transfered successfully to host.");
    } catch (Exception ex) {
        System.out.println("Exception found while tranfer the response.");
    } finally {
        channelSftp.exit();
        System.out.println("sftp Channel exited.");
        channel.disconnect();
        System.out.println("Channel disconnected.");
        session.disconnect();
        System.out.println("Host Session disconnected.");
    }
}   

Retrieving an element from array list in Android?

In arraylist you have a positional order and not a nominal order, so you need to know in advance the element position you need to select or you must loop between elements until you find the element that you need to use. To do this you can use an iterator and an if, for example:

Iterator iter = list.iterator();
while (iter.hasNext())
{
    // if here          
    System.out.println("string " + iter.next());
}

Python Git Module experiences?

Here's a really quick implementation of "git status":

import os
import string
from subprocess import *

repoDir = '/Users/foo/project'

def command(x):
    return str(Popen(x.split(' '), stdout=PIPE).communicate()[0])

def rm_empty(L): return [l for l in L if (l and l!="")]

def getUntracked():
    os.chdir(repoDir)
    status = command("git status")
    if "# Untracked files:" in status:
        untf = status.split("# Untracked files:")[1][1:].split("\n")
        return rm_empty([x[2:] for x in untf if string.strip(x) != "#" and x.startswith("#\t")])
    else:
        return []

def getNew():
    os.chdir(repoDir)
    status = command("git status").split("\n")
    return [x[14:] for x in status if x.startswith("#\tnew file:   ")]

def getModified():
    os.chdir(repoDir)
    status = command("git status").split("\n")
    return [x[14:] for x in status if x.startswith("#\tmodified:   ")]

print("Untracked:")
print( getUntracked() )
print("New:")
print( getNew() )
print("Modified:")
print( getModified() )

Subtracting 1 day from a timestamp date

Use the INTERVAL type to it. E.g:

--yesterday
SELECT NOW() - INTERVAL '1 DAY';

--Unrelated to the question, but PostgreSQL also supports some shortcuts:
SELECT 'yesterday'::TIMESTAMP, 'tomorrow'::TIMESTAMP, 'allballs'::TIME;

Then you can do the following on your query:

SELECT 
    org_id,
    count(accounts) AS COUNT,
    ((date_at) - INTERVAL '1 DAY') AS dateat
FROM 
    sourcetable
WHERE 
    date_at <= now() - INTERVAL '130 DAYS'
GROUP BY 
    org_id,
    dateat;


TIPS

Tip 1

You can append multiple operands. E.g.: how to get last day of current month?

SELECT date_trunc('MONTH', CURRENT_DATE) + INTERVAL '1 MONTH - 1 DAY';

Tip 2

You can also create an interval using make_interval function, useful when you need to create it at runtime (not using literals):

SELECT make_interval(days => 10 + 2);
SELECT make_interval(days => 1, hours => 2);
SELECT make_interval(0, 1, 0, 5, 0, 0, 0.0);


More info:

Date/Time Functions and Operators

datatype-datetime (Especial values).

What is the bit size of long on 64-bit Windows?

This article on MSDN references a number of type aliases (available on Windows) that are a bit more explicit with respect to their width:

http://msdn.microsoft.com/en-us/library/aa505945.aspx

For instance, although you can use ULONGLONG to reference a 64-bit unsigned integral value, you can also use UINT64. (The same goes for ULONG and UINT32.) Perhaps these will be a bit clearer?

How to select following sibling/xml tag using xpath

How would I accomplish the nextsibling and is there an easier way of doing this?

You may use:

tr/td[@class='name']/following-sibling::td

but I'd rather use directly:

tr[td[@class='name'] ='Brand']/td[@class='desc']

This assumes that:

  1. The context node, against which the XPath expression is evaluated is the parent of all tr elements -- not shown in your question.

  2. Each tr element has only one td with class attribute valued 'name' and only one td with class attribute valued 'desc'.

What does a Status of "Suspended" and high DiskIO means from sp_who2?

This is a very broad question, so I am going to give a broad answer.

  1. A query gets suspended when it is requesting access to a resource that is currently not available. This can be a logical resource like a locked row or a physical resource like a memory data page. The query starts running again, once the resource becomes available. 
  2. High disk IO means that a lot of data pages need to be accessed to fulfill the request.

That is all that I can tell from the above screenshot. However, if I were to speculate, you probably have an IO subsystem that is too slow to keep up with the demand. This could be caused by missing indexes or an actually too slow disk. Keep in mind, that 15000 reads for a single OLTP query is slightly high but not uncommon.

Moving Panel in Visual Studio Code to right side

"workbench.panel.defaultLocation": "right",

Bootstrap 4 - Responsive cards in card-columns

Update 2019 - Bootstrap 4

You can simply use the SASS mixin to change the number of cards across in each breakpoint / grid tier.

.card-columns {
  @include media-breakpoint-only(xl) {
    column-count: 5;
  }
  @include media-breakpoint-only(lg) {
    column-count: 4;
  }
  @include media-breakpoint-only(md) {
    column-count: 3;
  }
  @include media-breakpoint-only(sm) {
    column-count: 2;
  }
}

SASS Demo: http://www.codeply.com/go/FPBCQ7sOjX

Or, CSS only like this...

@media (min-width: 576px) {
    .card-columns {
        column-count: 2;
    }
}

@media (min-width: 768px) {
    .card-columns {
        column-count: 3;
    }
}

@media (min-width: 992px) {
    .card-columns {
        column-count: 4;
    }
}

@media (min-width: 1200px) {
    .card-columns {
        column-count: 5;
    }
}

CSS-only Demo: https://www.codeply.com/go/FIqYTyyWWZ

Vue Js - Loop via v-for X times (in a range)

You can use the native JS slice method:

<div v-for="item in shoppingItems.slice(0,10)">

The slice() method returns the selected elements in an array, as a new array object.

Based on tip in the migration guide: https://vuejs.org/v2/guide/migration.html#Replacing-the-limitBy-Filter

How can I select item with class within a DIV?

Try this

$("#mydiv div.myclass")

Removing App ID from Developer Connection

As @AlexanderN pointed out, you can now delete App IDs.

  1. In your Member Center go to the Certificates, Identifiers & Profiles section.
  2. Go to Identifiers folder.
  3. Select the App ID you want to delete and click Settings
  4. Scroll down and click Delete.

dropping a global temporary table

-- First Truncate temporary table
SQL> TRUNCATE TABLE test_temp1;

-- Then Drop temporary table
SQL> DROP TABLE test_temp1;

How to fix '.' is not an internal or external command error

Replacing forward(/) slash with backward(\) slash will do the job. The folder separator in Windows is \ not /

HTTP Request in Swift with POST method

Heres the method I used in my logging library: https://github.com/goktugyil/QorumLogs

This method fills html forms inside Google Forms.

    var url = NSURL(string: urlstring)

    var request = NSMutableURLRequest(URL: url!)
    request.HTTPMethod = "POST"
    request.setValue("application/x-www-form-urlencoded; charset=utf-8", forHTTPHeaderField: "Content-Type")
    request.HTTPBody = postData.dataUsingEncoding(NSUTF8StringEncoding)
    var connection = NSURLConnection(request: request, delegate: nil, startImmediately: true)

jQuery .load() call doesn't execute JavaScript in loaded HTML file

I was able to fix this issue by changing $(document).ready() to window.onLoad().

Apply style to only first level of td tags

I wanted to set the width of the first column of the table, and I found this worked (in FF7) - the first column is 50px wide:

#MyTable>thead>tr>th:first-child { width:50px;}

where my markup was

<table id="MyTable">
 <thead>
  <tr>
   <th scope="col">Col1</th>
   <th scope="col">Col2</th>
  </tr>
 </thead>
 <tbody>
   ...
 </tbody>
</table>

WebView showing ERR_CLEARTEXT_NOT_PERMITTED although site is HTTPS

When you call "https://darkorbit.com/" your server figures that it's missing "www" so it redirects the call to "http://www.darkorbit.com/" and then to "https://www.darkorbit.com/", your WebView call is blocked at the first redirection as it's a "http" call. You can call "https://www.darkorbit.com/" instead and it will solve the issue.

Magento - Retrieve products with a specific attribute value

$attribute = Mage::getModel('eav/entity_attribute')
                ->loadByCode('catalog_product', 'manufacturer');

$valuesCollection = Mage::getResourceModel('eav/entity_attribute_option_collection')
            ->setAttributeFilter($attribute->getData('attribute_id'))
            ->setStoreFilter(0, false);

$preparedManufacturers = array();            
foreach($valuesCollection as $value) {
    $preparedManufacturers[$value->getOptionId()] = $value->getValue();
}   


if (count($preparedManufacturers)) {
    echo "<h2>Manufacturers</h2><ul>";
    foreach($preparedManufacturers as $optionId => $value) {
        $products = Mage::getModel('catalog/product')->getCollection();
        $products->addAttributeToSelect('manufacturer');
        $products->addFieldToFilter(array(
            array('attribute'=>'manufacturer', 'eq'=> $optionId,          
        ));

        echo "<li>" . $value . " - (" . $optionId . ") - (Products: ".count($products).")</li>";
    }
    echo "</ul>";
}

How do I perform HTML decoding/encoding using Python/Django?

Use daniel's solution if the set of encoded characters is relatively restricted. Otherwise, use one of the numerous HTML-parsing libraries.

I like BeautifulSoup because it can handle malformed XML/HTML :

http://www.crummy.com/software/BeautifulSoup/

for your question, there's an example in their documentation

from BeautifulSoup import BeautifulStoneSoup
BeautifulStoneSoup("Sacr&eacute; bl&#101;u!", 
                   convertEntities=BeautifulStoneSoup.HTML_ENTITIES).contents[0]
# u'Sacr\xe9 bleu!'

Regular Expression: Allow letters, numbers, and spaces (with at least one letter or number)

^[ _]*[A-Z0-9][A-Z0-9 _]*$

You can optionally have some spaces or underscores up front, then you need one letter or number, and then an arbitrary number of numbers, letters, spaces or underscores after that.

Something that contains only spaces and underscores will fail the [A-Z0-9] portion.

Mask output of `The following objects are masked from....:` after calling attach() function

You use attach without detach - every time you do it new call to attach masks objects attached before (they contain the same names). Either use detach or do not use attach at all. Nice discussion and tips are here.

Split string into individual words Java

Use split()

String words[] = stringInstance.split(" ");

Java socket API: How to tell if a connection has been closed?

There is no TCP API that will tell you the current state of the connection. isConnected() and isClosed() tell you the current state of your socket. Not the same thing.

  1. isConnected() tells you whether you have connected this socket. You have, so it returns true.

  2. isClosed() tells you whether you have closed this socket. Until you have, it returns false.

  3. If the peer has closed the connection in an orderly way

    • read() returns -1
    • readLine() returns null
    • readXXX() throws EOFException for any other XXX.

    • A write will throw an IOException: 'connection reset by peer', eventually, subject to buffering delays.

  4. If the connection has dropped for any other reason, a write will throw an IOException, eventually, as above, and a read may do the same thing.

  5. If the peer is still connected but not using the connection, a read timeout can be used.

  6. Contrary to what you may read elsewhere, ClosedChannelException doesn't tell you this. [Neither does SocketException: socket closed.] It only tells you that you closed the channel, and then continued to use it. In other words, a programming error on your part. It does not indicate a closed connection.

  7. As a result of some experiments with Java 7 on Windows XP it also appears that if:

    • you're selecting on OP_READ
    • select() returns a value of greater than zero
    • the associated SelectionKey is already invalid (key.isValid() == false)

    it means the peer has reset the connection. However this may be peculiar to either the JRE version or platform.

How to convert a DataFrame back to normal RDD in pyspark?

@dapangmao's answer works, but it doesn't give the regular spark RDD, it returns a Row object. If you want to have the regular RDD format.

Try this:

rdd = df.rdd.map(tuple)

or

rdd = df.rdd.map(list)

How do I link to Google Maps with a particular longitude and latitude?

To get your current location as start point you need to use this URL:

https://www.google.com/maps/dir/?api=1&origin=Current+Location&destination=<latitude>,<longitude>

You can fill up the destination parameter with the address, name or latitude and longitude values.

CSS rotation cross browser with jquery.animate()

Without plugin cross browser with setInterval:

                        function rotatePic() {
                            jQuery({deg: 0}).animate(
                               {deg: 360},  
                               {duration: 3000, easing : 'linear', 
                                 step: function(now, fx){
                                   jQuery("#id").css({
                                      '-moz-transform':'rotate('+now+'deg)',
                                      '-webkit-transform':'rotate('+now+'deg)',
                                      '-o-transform':'rotate('+now+'deg)',
                                      '-ms-transform':'rotate('+now+'deg)',
                                      'transform':'rotate('+now+'deg)'
                                  });
                              }
                            });
                        }

                        var sec = 3;
                        rotatePic();
                        var timerInterval = setInterval(function() {
                            rotatePic();
                            sec+=3;
                            if (sec > 30) {
                                clearInterval(timerInterval);
                            }
                        }, 3000);

How to set selected value of jquery select2?

    $("#select_location_id").val(value);
    $("#select_location_id").select2().trigger('change');

I solved my problem with this simple code. Where #select_location_id is an ID of select box and value is value of an option listed in select2 box.

How to hide a button programmatically?

Please try this: playButton = (Button) findViewById(R.id.play); playButton.setVisibility(View.INVISIBLE); I think this will do it.

How do I select the "last child" with a specific class name in CSS?

You can't target the last instance of the class name in your list without JS.

However, you may not be entirely out-of-css-luck, depending on what you are wanting to achieve. For example, by using the next sibling selector, I have added a visual divider after the last of your .list elements here: http://jsbin.com/vejixisudo/edit?html,css,output

JSON Array iteration in Android/Java

On Arrays, look for:

JSONArray menuitemArray = popupObject.getJSONArray("menuitem"); 

Eclipse No tests found using JUnit 5 caused by NoClassDefFoundError for LauncherFactory

This issue happening while implementing Mockito with spring boot api. Below add below dependency in in gradle file

compile group: 'org.mockito', name: 'mockito-core', version: '2.22.0'

Note: Spring boot version 2.2.0

running multiple bash commands with subprocess

Join commands with "&&".

os.system('echo a > outputa.txt && echo b > outputb.txt')

Is there a template engine for Node.js?

You should take a look at node-asyncEJS, which is explicitly designed to take the asynchronous nature of node.js into account. It even allows async code blocks inside of the template.

Here an example form the documentation:

<html>
  <head>
    <% ctx.hello = "World";  %>
    <title><%= "Hello " + ctx.hello %></title>
  </head>
  <body>

    <h1><%? setTimeout(function () { res.print("Async Header"); res.finish(); }, 2000)  %></h1>
    <p><%? setTimeout(function () { res.print("Body"); res.finish(); }, 1000)  %></p>

  </body>
</html>

IntelliJ: Working on multiple projects

To Intellij IDEA 2019.2, F4 + click on module, click to + for add any project from your HDD, above this menu yo can edit the IDE with you create the project and more options, very easy

What's the difference between HEAD, working tree and index, in Git?

A few other good references on those topics:

workflow

I use the index as a checkpoint.

When I'm about to make a change that might go awry — when I want to explore some direction that I'm not sure if I can follow through on or even whether it's a good idea, such as a conceptually demanding refactoring or changing a representation type — I checkpoint my work into the index.

If this is the first change I've made since my last commit, then I can use the local repository as a checkpoint, but often I've got one conceptual change that I'm implementing as a set of little steps.
I want to checkpoint after each step, but save the commit until I've gotten back to working, tested code.

Notes:

  1. the workspace is the directory tree of (source) files that you see and edit.

  2. The index is a single, large, binary file in <baseOfRepo>/.git/index, which lists all files in the current branch, their sha1 checksums, time stamps and the file name -- it is not another directory with a copy of files in it.

  3. The local repository is a hidden directory (.git) including an objects directory containing all versions of every file in the repo (local branches and copies of remote branches) as a compressed "blob" file.

Don't think of the four 'disks' represented in the image above as separate copies of the repo files.

3 states

They are basically named references for Git commits. There are two major types of refs: tags and heads.

  • Tags are fixed references that mark a specific point in history, for example v2.6.29.
  • On the contrary, heads are always moved to reflect the current position of project development.

commits

(note: as commented by Timo Huovinen, those arrows are not what the commits point to, it's the workflow order, basically showing arrows as 1 -> 2 -> 3 -> 4 where 1 is the first commit and 4 is the last)

Now we know what is happening in the project.
But to know what is happening right here, right now there is a special reference called HEAD. It serves two major purposes:

  • it tells Git which commit to take files from when you checkout, and
  • it tells Git where to put new commits when you commit.

When you run git checkout ref it points HEAD to the ref you’ve designated and extracts files from it. When you run git commit it creates a new commit object, which becomes a child of current HEAD. Normally HEAD points to one of the heads, so everything works out just fine.

checkout

Bootstrap: Open Another Modal in Modal

You can actually detect when the old modal closes by calling the hidden.bs.modal event:

    $('.yourButton').click(function(e){
        e.preventDefault();

        $('#yourFirstModal')
            .modal('hide')
            .on('hidden.bs.modal', function (e) {
                $('#yourSecondModal').modal('show');

                $(this).off('hidden.bs.modal'); // Remove the 'on' event binding
            });

    });

For more info: http://getbootstrap.com/javascript/#modals-events

How to get all selected values of a multiple select box?

Same as the earlier answer but using underscore.js.

function getSelectValues(select) {
    return _.map(_.filter(select.options, function(opt) { 
        return opt.selected; }), function(opt) { 
            return opt.value || opt.text; });
}

How to make an ng-click event conditional?

It is not good to manipulate with DOM (including checking of attributes) in any place except directives. You can add into scope some value indicating if link should be disabled.

But other problem is that ngDisabled does not work on anything except form controls, so you can't use it with <a>, but you can use it with <button> and style it as link.

Another way is to use lazy evaluation of expressions like isDisabled || action() so action wouold not be called if isDisabled is true.

Here goes both solutions: http://plnkr.co/edit/5d5R5KfD4PCE8vS3OSSx?p=preview

MVC 5 Access Claims Identity User Data

Request.GetOwinContext().Authentication.User.Claims

However it is better to add the claims inside the "GenerateUserIdentityAsync" method, especially if regenerateIdentity in the Startup.Auth.cs is enabled.

How do I show a console output/window in a forms application?

Perhaps this is over-simplistic...

Create a Windows Form project...

Then: Project Properties -> Application -> Output Type -> Console Application

Then can have Console and Forms running together, works for me

Minimum and maximum value of z-index?

While INT_MAX is probably the safest bet, WebKit apparently uses doubles internally and thus allows very large numbers (to a certain precision). LLONG_MAX e.g. works fine (at least in 64-Bit Chromium and WebkitGTK), but will be rounded to 9223372036854776000.

(Although you should consider carefully whether you really, really need this many z indices…).

How to update a single library with Composer?

To ensure that composer update one package already installed to the last version within the version constraints you've set in composer.json remove the package from vendor and then execute :

php composer.phar update vendor/package

Laravel Mail::send() sending to multiple to or bcc addresses

I am using Laravel 5.6 and the Notifications Facade.

If I set a variable with comma separating the e-mails and try to send it, I get the error: "Address in mail given does not comply with RFC 2822, 3.6.2"

So, to solve the problem, I got the solution idea from @Toskan, coding the following.

        // Get data from Database
        $contacts = Contacts::select('email')
            ->get();

        // Create an array element
        $contactList = [];
        $i=0;

        // Fill the array element
        foreach($contacts as $contact){
            $contactList[$i] = $contact->email;
            $i++;
        }

        .
        .
        .

        \Mail::send('emails.template', ['templateTitle'=>$templateTitle, 'templateMessage'=>$templateMessage, 'templateSalutation'=>$templateSalutation, 'templateCopyright'=>$templateCopyright], function($message) use($emailReply, $nameReply, $contactList) {
                $message->from('[email protected]', 'Some Company Name')
                        ->replyTo($emailReply, $nameReply)
                        ->bcc($contactList, 'Contact List')
                        ->subject("Subject title");
            });

It worked for me to send to one or many recipients.

C# DataTable.Select() - How do I format the filter criteria to include null?

Try out Following:

DataRow rows = DataTable.Select("[Name]<>'n/a'")

For Null check in This:

DataRow rows =  DataTable.Select("[Name] <> 'n/a' OR [Name] is NULL" )

How do you programmatically update query params in react-router?

Example using react-router v4, redux-thunk and react-router-redux(5.0.0-alpha.6) package.

When user uses search feature, I want him to be able to send url link for same query to a colleague.

import { push } from 'react-router-redux';
import qs from 'query-string';

export const search = () => (dispatch) => {
    const query = { firstName: 'John', lastName: 'Doe' };

    //API call to retrieve records
    //...

    const searchString = qs.stringify(query);

    dispatch(push({
        search: searchString
    }))
}

How do I remove objects from a JavaScript associative array?

As other answers have noted, you are not using a JavaScript array, but a JavaScript object, which works almost like an associative array in other languages except that all keys are converted to strings. The new Map stores keys as their original type.

If you had an array and not an object, you could use the array's .filter function, to return a new array without the item you want removed:

var myArray = ['Bob', 'Smith', 25];
myArray = myArray.filter(function(item) {
    return item !== 'Smith';
});

If you have an older browser and jQuery, jQuery has a $.grep method that works similarly:

myArray = $.grep(myArray, function(item) {
    return item !== 'Smith';
});

INNER JOIN vs LEFT JOIN performance in SQL Server

There is one important scenario that can lead to an outer join being faster than an inner join that has not been discussed yet.

When using an outer join, the optimizer is always free to drop the outer joined table from the execution plan if the join columns are the PK of the outer table, and none of the outer table columns are referenced outside of the outer join itself. For example SELECT A.* FROM A LEFT OUTER JOIN B ON A.KEY=B.KEY and B.KEY is the PK for B. Both Oracle (I believe I was using release 10) and Sql Server (I used 2008 R2) prune table B from the execution plan.

The same is not necessarily true for an inner join: SELECT A.* FROM A INNER JOIN B ON A.KEY=B.KEY may or may not require B in the execution plan depending on what constraints exist.

If A.KEY is a nullable foreign key referencing B.KEY, then the optimizer cannot drop B from the plan because it must confirm that a B row exists for every A row.

If A.KEY is a mandatory foreign key referencing B.KEY, then the optimizer is free to drop B from the plan because the constraints guarantee the existence of the row. But just because the optimizer can drop the table from the plan, doesn't mean it will. SQL Server 2008 R2 does NOT drop B from the plan. Oracle 10 DOES drop B from the plan. It is easy to see how the outer join will out-perform the inner join on SQL Server in this case.

This is a trivial example, and not practical for a stand-alone query. Why join to a table if you don't need to?

But this could be a very important design consideration when designing views. Frequently a "do-everything" view is built that joins everything a user might need related to a central table. (Especially if there are naive users doing ad-hoc queries that do not understand the relational model) The view may include all the relevent columns from many tables. But the end users might only access columns from a subset of the tables within the view. If the tables are joined with outer joins, then the optimizer can (and does) drop the un-needed tables from the plan.

It is critical to make sure that the view using outer joins gives the correct results. As Aaronaught has said - you cannot blindly substitute OUTER JOIN for INNER JOIN and expect the same results. But there are times when it can be useful for performance reasons when using views.

One last note - I haven't tested the impact on performance in light of the above, but in theory it seems you should be able to safely replace an INNER JOIN with an OUTER JOIN if you also add the condition <FOREIGN_KEY> IS NOT NULL to the where clause.

Implement Validation for WPF TextBoxes

To get it done only with XAML you need to add Validation Rules for individual properties. But i would recommend you to go with code behind approach. In your code, define your specifications in properties setters and throw exceptions when ever it doesn't compliance to your specifications. And use error template to display your errors to user in UI. Your XAML will look like this

<Window x:Class="WpfApplication1.MainWindow"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    Title="MainWindow" Height="350" Width="525">
<Window.Resources>
    <Style x:Key="CustomTextBoxTextStyle" TargetType="TextBox">
        <Setter Property="Foreground" Value="Green" />
        <Setter Property="MaxLength" Value="40" />
        <Setter Property="Width" Value="392" />
        <Style.Triggers>
            <Trigger Property="Validation.HasError" Value="True">
                <Trigger.Setters>
                    <Setter Property="ToolTip" Value="{Binding RelativeSource={RelativeSource Self},Path=(Validation.Errors)[0].ErrorContent}"/>
                    <Setter Property="Background" Value="Red"/>
                </Trigger.Setters>
            </Trigger>
        </Style.Triggers>
    </Style>
</Window.Resources>
<Grid>
    <TextBox Name="tb2" Height="30" Width="400"
             Text="{Binding Name, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged, ValidatesOnExceptions=True}" 
             Style="{StaticResource CustomTextBoxTextStyle}"/>
</Grid>

Code Behind:

public partial class MainWindow : Window
{
    private ExampleViewModel m_ViewModel;
    public MainWindow()
    {
        InitializeComponent();
        m_ViewModel = new ExampleViewModel();
        DataContext = m_ViewModel;
    }
}


public class ExampleViewModel : INotifyPropertyChanged
{
    private string m_Name = "Type Here";
    public ExampleViewModel()
    {

    }

    public string Name
    {
        get
        {
            return m_Name;
        }
        set
        {
            if (String.IsNullOrEmpty(value))
            {
                throw new Exception("Name can not be empty.");
            }
            if (value.Length > 12)
            {
                throw new Exception("name can not be longer than 12 charectors");
            }
            if (m_Name != value)
            {
                m_Name = value;
                OnPropertyChanged("Name");
            }
        }
    }


    public event PropertyChangedEventHandler PropertyChanged;
    protected void OnPropertyChanged(string propertyName)
    {
        if (PropertyChanged != null)
        {
            PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
        }

    }
}

How to append text to an existing file in Java?

Better to use try-with-resources then all that pre-java 7 finally business

static void appendStringToFile(Path file, String s) throws IOException  {
    try (BufferedWriter out = Files.newBufferedWriter(file, StandardCharsets.UTF_8, StandardOpenOption.APPEND)) {
        out.append(s);
        out.newLine();
    }
}

What is an idiomatic way of representing enums in Go?

There is a way with struct namespace.

The benefit is all enum variables are under a specific namespace to avoid pollution. The issue is that we could only use var not const

type OrderStatusType string

var OrderStatus = struct {
    APPROVED         OrderStatusType
    APPROVAL_PENDING OrderStatusType
    REJECTED         OrderStatusType
    REVISION_PENDING OrderStatusType
}{
    APPROVED:         "approved",
    APPROVAL_PENDING: "approval pending",
    REJECTED:         "rejected",
    REVISION_PENDING: "revision pending",
}

jQuery: get data attribute

1. Try this: .attr()

  $('.field').hover(function () {
    var value=$(this).attr('data-fullText');
  $(this).html(value);
});

DEMO 1: http://jsfiddle.net/hsakapandit/Jn4V3/

2. Try this: .data()

$('.field').hover(function () {
    var value=$(this).data('fulltext');
  $(this).html(value);
});

DEMO 2: http://jsfiddle.net/hsakapandit/Jn4V3/1/

Difference between thread's context class loader and normal classloader

Adding to @David Roussel answer, classes may be loaded by multiple class loaders.

Lets understand how class loader works.

From javin paul blog in javarevisited :

enter image description here

enter image description here

ClassLoader follows three principles.

Delegation principle

A class is loaded in Java, when its needed. Suppose you have an application specific class called Abc.class, first request of loading this class will come to Application ClassLoader which will delegate to its parent Extension ClassLoader which further delegates to Primordial or Bootstrap class loader

  • Bootstrap ClassLoader is responsible for loading standard JDK class files from rt.jar and it is parent of all class loaders in Java. Bootstrap class loader don't have any parents.

  • Extension ClassLoader delegates class loading request to its parent, Bootstrap and if unsuccessful, loads class form jre/lib/ext directory or any other directory pointed by java.ext.dirs system property

  • System or Application class loader and it is responsible for loading application specific classes from CLASSPATH environment variable, -classpath or -cp command line option, Class-Path attribute of Manifest file inside JAR.

  • Application class loader is a child of Extension ClassLoader and its implemented by sun.misc.Launcher$AppClassLoader class.

NOTE: Except Bootstrap class loader, which is implemented in native language mostly in C, all Java class loaders are implemented using java.lang.ClassLoader.

Visibility Principle

According to visibility principle, Child ClassLoader can see class loaded by Parent ClassLoader but vice-versa is not true.

Uniqueness Principle

According to this principle a class loaded by Parent should not be loaded by Child ClassLoader again

jQuery If DIV Doesn't Have Class "x"

jQuery has the hasClass() function that returns true if any element in the wrapped set contains the specified class

if (!$(this).hasClass("selected")) {
    //do stuff
}

Take a look at my example of use

  • If you hover over a div, it fades as normal speed to 100% opacity if the div does not contain the 'selected' class
  • If you hover out of a div, it fades at slow speed to 30% opacity if the div does not contain the 'selected' class
  • Clicking the button adds 'selected' class to the red div. The fading effects no longer work on the red div

Here is the code for it

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
  "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">
<head>
<script src="http://ajax.googleapis.com/ajax/libs/jquery/1.3.1/jquery.min.js"></script>
<title>Sandbox</title>
<meta http-equiv="Content-type" content="text/html; charset=utf-8" />
<style type="text/css" media="screen">
body { background-color: #FFF; font: 16px Helvetica, Arial; color: #000; }
</style>


<!-- jQuery code here -->
<script type="text/javascript">
$(function() {

$('#myButton').click(function(e) {
$('#div2').addClass('selected');
});

$('.thumbs').bind('click',function(e) { alert('You clicked ' + e.target.id ); } );

$('.thumbs').hover(fadeItIn, fadeItOut);


});

function fadeItIn(e) {
if (!$(e.target).hasClass('selected')) 
 { 
    $(e.target).fadeTo('normal', 1.0); 
  } 
}

function fadeItOut(e) { 
  if (!$(e.target).hasClass('selected'))
  { 
    $(e.target).fadeTo('slow', 0.3); 
 } 
}
</script>


</head>
<body>
<div id="div1" class="thumbs" style=" background-color: #0f0; margin: 10px; padding: 10px; width: 100px; height: 50px; clear: both;"> 
One div with a thumbs class
</div>
<div id="div2" class="thumbs" style=" background-color: #f00; margin: 10px; padding: 10px; width: 100px; height: 50px; clear: both;">
Another one with a thumbs class
</div>
<input type="button" id="myButton" value="add 'selected' class to red div" />
</body>
</html>

EDIT:

this is just a guess, but are you trying to achieve something like this?

  • Both divs start at 30% opacity
  • Hovering over a div fades to 100% opacity, hovering out fades back to 30% opacity. Fade effects only work on elements that don't have the 'selected' class
  • Clicking a div adds/removes the 'selected' class

jQuery Code is here-

$(function() {

$('.thumbs').bind('click',function(e) { $(e.target).toggleClass('selected'); } );
$('.thumbs').hover(fadeItIn, fadeItOut);
$('.thumbs').css('opacity', 0.3);

});

function fadeItIn(e) {
if (!$(e.target).hasClass('selected')) 
 { 
    $(e.target).fadeTo('normal', 1.0); 
  } 
}

function fadeItOut(e) { 
  if (!$(e.target).hasClass('selected'))
  { 
    $(e.target).fadeTo('slow', 0.3); 
 } 
}

<div id="div1" class="thumbs" style=" background-color: #0f0; margin: 10px; padding: 10px; width: 100px; height: 50px; clear: both; cursor:pointer;"> 
One div with a thumbs class
</div>
<div id="div2" class="thumbs" style=" background-color: #f00; margin: 10px; padding: 10px; width: 100px; height: 50px; clear: both; cursor:pointer;">
Another one with a thumbs class
</div>

Image is not showing in browser?

You need to import your image from the image folder. import name_of_image from '../imageFolder/name_of_image.jpg';

<img src={name_of_image} alt=''>

Please refer here. https://create-react-app.dev/docs/adding-images-fonts-and-files -

How to allocate aligned memory only using the standard library?

You could also try posix_memalign() (on POSIX platforms, of course).

How to have PHP display errors? (I've added ini_set and error_reporting, but just gives 500 on errors)

Syntax errors is not checked easily in external servers, just runtime errors.

What I do? Just like you, I use

ini_set('display_errors', 'On');
error_reporting(E_ALL);

However, before run I check syntax errors in a PHP file using an online PHP syntax checker.

The best, IMHO is PHP Code Checker

I copy all the source code, paste inside the main box and click the Analyze button.

It is not the most practical method, but the 2 procedures are complementary and it solves the problem completely

How to return a boolean method in java?

You can also do this, for readability's sake

boolean passwordVerified=(pword.equals(pwdRetypePwd.getText());

if(!passwordVerified ){
    txtaError.setEditable(true);
    txtaError.setText("*Password didn't match!");
    txtaError.setForeground(Color.red);
    txtaError.setEditable(false);
}else{
    addNewUser();
}
return passwordVerified;

Extract substring in Bash

Here's how i'd do it:

FN=someletters_12345_moreleters.ext
[[ ${FN} =~ _([[:digit:]]{5})_ ]] && NUM=${BASH_REMATCH[1]}

Explanation:

Bash-specific:

Regular Expressions (RE): _([[:digit:]]{5})_

  • _ are literals to demarcate/anchor matching boundaries for the string being matched
  • () create a capture group
  • [[:digit:]] is a character class, i think it speaks for itself
  • {5} means exactly five of the prior character, class (as in this example), or group must match

In english, you can think of it behaving like this: the FN string is iterated character by character until we see an _ at which point the capture group is opened and we attempt to match five digits. If that matching is successful to this point, the capture group saves the five digits traversed. If the next character is an _, the condition is successful, the capture group is made available in BASH_REMATCH, and the next NUM= statement can execute. If any part of the matching fails, saved details are disposed of and character by character processing continues after the _. e.g. if FN where _1 _12 _123 _1234 _12345_, there would be four false starts before it found a match.

How do I check if a property exists on a dynamic anonymous type in c#?

Using reflection, this is the function i use :

public static bool doesPropertyExist(dynamic obj, string property)
{
    return ((Type)obj.GetType()).GetProperties().Where(p => p.Name.Equals(property)).Any();
}

then..

if (doesPropertyExist(myDynamicObject, "myProperty")){
    // ...
}

java.util.zip.ZipException: duplicate entry during packageAllDebugClassesForMultiDex

I tried all the above solutions but not working for me. I tried update libraries by goto project structure > app. And it works for me! Hope this answer helpful to someone.

Android - implementing startForeground for a service?

Note: If your app targets API level 26 or higher, the system imposes restrictions on using or creating background services unless the app itself is in the foreground.

If an app needs to create a foreground service, the app should call startForegroundService(). That method creates a background service, but the method signals to the system that the service will promote itself to the foreground.

Once the service has been created, the service must call its startForeground() method within five seconds.

What's the difference between using CGFloat and float?

Objective-C

From the Foundation source code, in CoreGraphics' CGBase.h:

/* Definition of `CGFLOAT_TYPE', `CGFLOAT_IS_DOUBLE', `CGFLOAT_MIN', and
   `CGFLOAT_MAX'. */

#if defined(__LP64__) && __LP64__
# define CGFLOAT_TYPE double
# define CGFLOAT_IS_DOUBLE 1
# define CGFLOAT_MIN DBL_MIN
# define CGFLOAT_MAX DBL_MAX
#else
# define CGFLOAT_TYPE float
# define CGFLOAT_IS_DOUBLE 0
# define CGFLOAT_MIN FLT_MIN
# define CGFLOAT_MAX FLT_MAX
#endif

/* Definition of the `CGFloat' type and `CGFLOAT_DEFINED'. */

typedef CGFLOAT_TYPE CGFloat;
#define CGFLOAT_DEFINED 1

Copyright (c) 2000-2011 Apple Inc.

This is essentially doing:

#if defined(__LP64__) && __LP64__
typedef double CGFloat;
#else
typedef float CGFloat;
#endif

Where __LP64__ indicates whether the current architecture* is 64-bit.

Note that 32-bit systems can still use the 64-bit double, it just takes more processor time, so CoreGraphics does this for optimization purposes, not for compatibility. If you aren't concerned about performance but are concerned about accuracy, simply use double.

Swift

In Swift, CGFloat is a struct wrapper around either Float on 32-bit architectures or Double on 64-bit ones (You can detect this at run- or compile-time with CGFloat.NativeType) and cgFloat.native.

From the CoreGraphics source code, in CGFloat.swift.gyb:

public struct CGFloat {
#if arch(i386) || arch(arm)
  /// The native type used to store the CGFloat, which is Float on
  /// 32-bit architectures and Double on 64-bit architectures.
  public typealias NativeType = Float
#elseif arch(x86_64) || arch(arm64)
  /// The native type used to store the CGFloat, which is Float on
  /// 32-bit architectures and Double on 64-bit architectures.
  public typealias NativeType = Double
#endif

*Specifically, longs and pointers, hence the LP. See also: http://www.unix.org/version2/whatsnew/lp64_wp.html

When to use a linked list over an array/array list?

To add to the other answers, most array list implementations reserve extra capacity at the end of the list so that new elements can be added to the end of the list in O(1) time. When the capacity of an array list is exceeded, a new, larger array is allocated internally, and all the old elements are copied over. Usually, the new array is double the size of the old one. This means that on average, adding new elements to the end of an array list is an O(1) operation in these implementations. So even if you don't know the number of elements in advance, an array list may still be faster than a linked list for adding elements, as long as you are adding them at the end. Obviously, inserting new elements at arbitrary locations in an array list is still an O(n) operation.

Accessing elements in an array list is also faster than a linked list, even if the accesses are sequential. This is because array elements are stored in contiguous memory and can be cached easily. Linked list nodes can potentially be scattered over many different pages.

I would recommend only using a linked list if you know that you're going to be inserting or deleting items at arbitrary locations. Array lists will be faster for pretty much everything else.

Java regular expression OR operator

You can just use the pipe on its own:

"string1|string2"

for example:

String s = "string1, string2, string3";
System.out.println(s.replaceAll("string1|string2", "blah"));

Output:

blah, blah, string3

The main reason to use parentheses is to limit the scope of the alternatives:

String s = "string1, string2, string3";
System.out.println(s.replaceAll("string(1|2)", "blah"));

has the same output. but if you just do this:

String s = "string1, string2, string3";
System.out.println(s.replaceAll("string1|2", "blah"));

you get:

blah, stringblah, string3

because you've said "string1" or "2".

If you don't want to capture that part of the expression use ?::

String s = "string1, string2, string3";
System.out.println(s.replaceAll("string(?:1|2)", "blah"));

How to see the proxy settings on windows?

It's possible to view proxy settings in Google Chrome:

chrome://net-internals/#proxy

Enter this in the address bar of Chrome.

Converting binary to decimal integer output

Try this solution:

def binary_int_to_decimal(binary):
    n = 0
    for d in binary:
        n = n * 2 + d

    return n

Access parent URL from iframe

For pages on the same domain and different subdomain, you can set the document.domain property via javascript.

Both the parent frame and the iframe need to set their document.domain to something that is common betweeen them.

i.e. www.foo.mydomain.com and api.foo.mydomain.com could each use either foo.mydomain.com or just mydomain.com and be compatible (no, you can't set them both to com, for security reasons...)

also, note that document.domain is a one way street. Consider running the following three statements in order:

// assume we're starting at www.foo.mydomain.com
document.domain = "foo.mydomain.com" // works
document.domain = "mydomain.com" // works
document.domain = "foo.mydomain.com" // throws a security exception

Modern browsers can also use window.postMessage to talk across origins, but it won't work in IE6. https://developer.mozilla.org/en/DOM/window.postMessage

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

Just try this:

<button type="button">Click Me</button>
<p></p>
<script type="text/javascript">
    $(document).ready(function(){
        $("button").click(function(){

            $.ajax({
                type: 'POST',
                url: 'script.php',
                success: function(data) {
                    alert(data);
                    $("p").text(data);

                }
            });
   });
});
</script>

In script.php

<?php 
  echo "You win";
 ?>

How does collections.defaultdict work?

My own 2¢: you can also subclass defaultdict:

class MyDict(defaultdict):
    def __missing__(self, key):
        value = [None, None]
        self[key] = value
        return value

This could come in handy for very complex cases.

How do I concatenate text in a query in sql server?

Another option is the CONCAT command:

SELECT CONCAT(MyTable.TextColumn, 'Text') FROM MyTable

Arrow operator (->) usage in C

foo->bar is only shorthand for (*foo).bar. That's all there is to it.

Getting rid of all the rounded corners in Twitter Bootstrap

Or you could add this to the html of the element you want to remove the border radius from (this way you wouldn't be removing it from all buttons / elements):

style="border-radius:0px; -webkit-border-radius:0px; -moz-border-radius:0px;"

What is the difference between os.path.basename() and os.path.dirname()?

To summarize what was mentioned by Breno above

Say you have a variable with a path to a file

path = '/home/User/Desktop/myfile.py'

os.path.basename(path) returns the string 'myfile.py'

and

os.path.dirname(path) returns the string '/home/User/Desktop' (without a trailing slash '/')

These functions are used when you have to get the filename/directory name given a full path name.

In case the file path is just the file name (e.g. instead of path = '/home/User/Desktop/myfile.py' you just have myfile.py), os.path.dirname(path) returns an empty string.

How do I cancel an HTTP fetch() request?

As for now there is no proper solution, as @spro says.

However, if you have an in-flight response and are using ReadableStream, you can close the stream to cancel the request.

fetch('http://example.com').then((res) => {
  const reader = res.body.getReader();

  /*
   * Your code for reading streams goes here
   */

  // To abort/cancel HTTP request...
  reader.cancel();
});