Programs & Examples On #Django contrib

django-contrib is a django package with a variety of extra, optional tools that solve common Web-development problems

Disable form auto submit on button click

Buttons like <button>Click to do something</button> are submit buttons.

Set type="button" to change that. type="submit" is the default (as specified by the HTML recommendation).

What is the difference between a strongly typed language and a statically typed language?

Strongly typed means that there are restrictions between conversions between types.

Statically typed means that the types are not dynamic - you can not change the type of a variable once it has been created.

Detect iPad users using jQuery?

Although the accepted solution is correct for iPhones, it will incorrectly declare both isiPhone and isiPad to be true for users visiting your site on their iPad from the Facebook app.

The conventional wisdom is that iOS devices have a user agent for Safari and a user agent for the UIWebView. This assumption is incorrect as iOS apps can and do customize their user agent. The main offender here is Facebook.

Compare these user agent strings from iOS devices:

# iOS Safari
iPad: Mozilla/5.0 (iPad; CPU OS 5_1 like Mac OS X) AppleWebKit/534.46 (KHTML, like Gecko) Version/5.1 Mobile/9B176 Safari/7534.48.3
iPhone: Mozilla/5.0 (iPhone; CPU iPhone OS 5_0 like Mac OS X) AppleWebKit/534.46 (KHTML, like Gecko) Version/5.1 Mobile/9A334 Safari/7534.48.3

# UIWebView
iPad: Mozilla/5.0 (iPad; CPU OS 5_1 like Mac OS X) AppleWebKit/534.46 (KHTML, like Gecko) Mobile/98176
iPhone: Mozilla/5.0 (iPhone; U; CPU iPhone OS 4_1 like Mac OS X; en-us) AppleWebKit/532.9 (KHTML, like Gecko) Mobile/8B117

# Facebook UIWebView
iPad: Mozilla/5.0 (iPad; U; CPU iPhone OS 5_1_1 like Mac OS X; en_US) AppleWebKit (KHTML, like Gecko) Mobile [FBAN/FBForIPhone;FBAV/4.1.1;FBBV/4110.0;FBDV/iPad2,1;FBMD/iPad;FBSN/iPhone OS;FBSV/5.1.1;FBSS/1; FBCR/;FBID/tablet;FBLC/en_US;FBSF/1.0]
iPhone: Mozilla/5.0 (iPhone; U; CPU iPhone OS 5_1_1 like Mac OS X; ru_RU) AppleWebKit (KHTML, like Gecko) Mobile [FBAN/FBForIPhone;FBAV/4.1;FBBV/4100.0;FBDV/iPhone3,1;FBMD/iPhone;FBSN/iPhone OS;FBSV/5.1.1;FBSS/2; tablet;FBLC/en_US]

Note that on the iPad, the Facebook UIWebView's user agent string includes 'iPhone'.

The old way to identify iPhone / iPad in JavaScript:

IS_IPAD = navigator.userAgent.match(/iPad/i) != null;
IS_IPHONE = navigator.userAgent.match(/iPhone/i) != null) || (navigator.userAgent.match(/iPod/i) != null);

If you were to go with this approach for detecting iPhone and iPad, you would end up with IS_IPHONE and IS_IPAD both being true if a user comes from Facebook on an iPad. That could create some odd behavior!

The correct way to identify iPhone / iPad in JavaScript:

IS_IPAD = navigator.userAgent.match(/iPad/i) != null;
IS_IPHONE = (navigator.userAgent.match(/iPhone/i) != null) || (navigator.userAgent.match(/iPod/i) != null);
if (IS_IPAD) {
  IS_IPHONE = false;
}

We declare IS_IPHONE to be false on iPads to cover for the bizarre Facebook UIWebView iPad user agent. This is one example of how user agent sniffing is unreliable. The more iOS apps that customize their user agent, the more issues user agent sniffing will have. If you can avoid user agent sniffing (hint: CSS Media Queries), DO IT.

Terminal Multiplexer for Microsoft Windows - Installers for GNU Screen or tmux

As of the Windows 10 "Anniversary" update (Version 1607), you can now run an Ubuntu subsystem from directly inside of Windows by enabling a feature called Developer mode.

To enable developer mode, go to Start > Settings then typing "Use developer features" in the search box to find the setting. On the left hand navigation, you will then see a tab titled For developers. From within this tab, you will see a radio box to enable Developer mode.

After developer mode is enabled, you will then be able to enable the Linux subsystem feature. To do so, go to Control Panel > Programs > Turn Windows features on or off > and check the box that says Windows Subsystem for Linux (Beta)

Now, rather than using Cygwin or a console emulator, you can run tmux through bash on the Ubuntu subsystem directly from Windows through the traditional apt package (sudo apt-get install tmux).

Deleting folders in python recursively

The command (given by Tomek) can't delete a file, if it is read only. therefore, one can use -

import os, sys
import stat

def del_evenReadonly(action, name, exc):
    os.chmod(name, stat.S_IWRITE)
    os.remove(name)

if  os.path.exists("test/qt_env"):
    shutil.rmtree('test/qt_env',onerror=del_evenReadonly)

Cannot open include file with Visual Studio

By default, Visual Studio searches for headers in the folder where your project is ($ProjectDir) and in the default standard libraries directories. If you need to include something that is not placed in your project directory, you need to add the path to the folder to include:

Go to your Project properties (Project -> Properties -> Configuration Properties -> C/C++ -> General) and in the field Additional Include Directories add the path to your .h file.

You can, also, as suggested by Chris Olen, add the path to VC++ Directories field.

recursion versus iteration

recursion + memorization could lead to a more efficient solution compare with a pure iterative approach, e.g. check this: http://jsperf.com/fibonacci-memoized-vs-iterative-for-large-n

Finding last index of a string in Oracle

Use -1 as the start position:

INSTR('JD-EQ-0001', '-', -1)

python encoding utf-8

Unfortunately, the string.encode() method is not always reliable. Check out this thread for more information: What is the fool proof way to convert some string (utf-8 or else) to a simple ASCII string in python

SQL Order By Count

You need to aggregate the data first, this can be done using the GROUP BY clause:

SELECT Group, COUNT(*)
FROM table
GROUP BY Group
ORDER BY COUNT(*) DESC

The DESC keyword allows you to show the highest count first, ORDER BY by default orders in ascending order which would show the lowest count first.

How to get current html page title with javascript

try like this

$('title').text();

TypeError: string indices must be integers, not str // working with dict

time1 is the key of the most outer dictionary, eg, feb2012. So then you're trying to index the string, but you can only do this with integers. I think what you wanted was:

for info in courses[time1][course]:

As you're going through each dictionary, you must add another nest.

"ORA-01438: value larger than specified precision allowed for this column" when inserting 3

You can't update with a number greater than 1 for datatype number(2,2) is because, the first parameter is the total number of digits in the number and the second one (.i.e 2 here) is the number of digits in decimal part. I guess you can insert or update data < 1. i.e. 0.12, 0.95 etc.

Please check NUMBER DATATYPE in NUMBER Datatype.

How can I add a hint or tooltip to a label in C# Winforms?

yourToolTip = new ToolTip();
//The below are optional, of course,

yourToolTip.ToolTipIcon = ToolTipIcon.Info;
yourToolTip.IsBalloon = true;
yourToolTip.ShowAlways = true;

yourToolTip.SetToolTip(lblYourLabel,"Oooh, you put your mouse over me.");

Nodemailer with Gmail and NodeJS

I solved this by going to the following url (while connected to google with the account I want to send mail from):

https://www.google.com/settings/security/lesssecureapps

There I enabled less secure apps.

Done

Node package ( Grunt ) installed but not available

Hello I had this problem on mac, and what I did was

installed globally and prefix with global path

sudo npm install grunt -g --prefix=/usr/local

now $ which grunt

should out put /usr/local/bin/grunt

Cheers

Moving Git repository content to another repository preserving history

As per @Dan-Cohn answer Mirror-push is your friend here. This is my go to for migrating repos:

Mirroring a repository

1.Open Git Bash.

2.Create a bare clone of the repository.

$ git clone --bare https://github.com/exampleuser/old-repository.git

3.Mirror-push to the new repository.

$ cd old-repository.git
$ git push --mirror https://github.com/exampleuser/new-repository.git

4.Remove the temporary local repository you created in step 1.

$ cd ..
$ rm -rf old-repository.git

Reference and Credit: https://help.github.com/en/articles/duplicating-a-repository

Excel function to get first word from sentence in other cell

If you want to cater to 1-word cell, use this... based upon astander's

=IFERROR(LEFT(A1,SEARCH(" ",A1)-1),A1)

How to use <sec:authorize access="hasRole('ROLES)"> for checking multiple Roles?

Within Spring Boot 2.4 it is

sec:authorize="hasAnyRole('ROLE_ADMIN')

Ensure that you have

thymeleaf-extras-springsecurity5

in your dependencies. Also make sure that you include the namespace

xmlns:sec="http://www.thymeleaf.org/extras/spring-security"

in your html...

Loop inside React JSX

Here is a sample from React doc:JavaScript Expressions as Children

function Item(props) {
  return <li>{props.message}</li>;
}

function TodoList() {
  const todos = ['finish doc', 'submit pr', 'nag dan to review'];
  return (
    <ul>
      {todos.map((message) => <Item key={message} message={message} />)}
    </ul>
  );
}

as your case, I suggest writing like this:

function render() {
  return (
    <tbody>
      {numrows.map((roe, index) => <ObjectRow key={index} />)}
    </tbody>
  );
}

Please notice the Key is very important, because React use Key to differ data in array.

<SELECT multiple> - how to allow only one item selected?

I am coming here after searching google and change thing at my-end.

So I just change this sample and it will work with jquery at run-time.

$('select[name*="homepage_select"]').removeAttr('multiple')

http://jsfiddle.net/ajayendra2707/ejkxgy1p/5/

Reverse colormap in matplotlib

The standard colormaps also all have reversed versions. They have the same names with _r tacked on to the end. (Documentation here.)

Difference Between ViewResult() and ActionResult()

While other answers have noted the differences correctly, note that if you are in fact returning a ViewResult only it is better to return the more specific type rather than the base ActionResult type. An obvious exception to this principle is when your method returns multiple types deriving from ActionResult.

For a full discussion of the reasons behind this principle please see the related discussion here: Must ASP.NET MVC Controller Methods Return ActionResult?

C99 stdint.h header and MS Visual Studio

Microsoft do not support C99 and haven't announced any plans to. I believe they intend to track C++ standards but consider C as effectively obsolete except as a subset of C++.

New projects in Visual Studio 2003 and later have the "Compile as C++ Code (/TP)" option set by default, so any .c files will be compiled as C++.

ExecuteNonQuery: Connection property has not been initialized.

just try this..

you need to open the connection using connection.open() on the SqlCommand.Connection object before executing ExecuteNonQuery()

Extract the first (or last) n characters of a string

Make it simple and use R basic functions:

# To get the LEFT part:
> substr(a, 1, 4)
[1] "left"
> 
# To get the MIDDLE part:
> substr(a, 3, 7)
[1] "ftrig"
> 
# To get the RIGHT part:
> substr(a, 5, 10)
[1] "right"

The substr() function tells you where start and stop substr(x, start, stop)

How to parse string into date?

You can use:

SELECT CONVERT(datetime, '24.04.2012', 103) AS Date

Reference: CAST and CONVERT (Transact-SQL)

NameError: global name 'unicode' is not defined - in Python 3

One can replace unicode with u''.__class__ to handle the missing unicode class in Python 3. For both Python 2 and 3, you can use the construct

isinstance(unicode_or_str, u''.__class__)

or

type(unicode_or_str) == type(u'')

Depending on your further processing, consider the different outcome:

Python 3

>>> isinstance('text', u''.__class__)
True
>>> isinstance(u'text', u''.__class__)
True

Python 2

>>> isinstance(u'text', u''.__class__)
True
>>> isinstance('text', u''.__class__)
False

What order are the Junit @Before/@After called?

This isn't an answer to the tagline question, but it is an answer to the problems mentioned in the body of the question. Instead of using @Before or @After, look into using @org.junit.Rule because it gives you more flexibility. ExternalResource (as of 4.7) is the rule you will be most interested in if you are managing connections. Also, If you want guaranteed execution order of your rules use a RuleChain (as of 4.10). I believe all of these were available when this question was asked. Code example below is copied from ExternalResource's javadocs.

 public static class UsesExternalResource {
  Server myServer= new Server();

  @Rule
  public ExternalResource resource= new ExternalResource() {
      @Override
      protected void before() throws Throwable {
          myServer.connect();
         };

      @Override
      protected void after() {
          myServer.disconnect();
         };
     };

  @Test
  public void testFoo() {
      new Client().run(myServer);
     }
 }

Remove Elements from a HashSet while Iterating

Java 8 Collection has a nice method called removeIf that makes things easier and safer. From the API docs:

default boolean removeIf(Predicate<? super E> filter)
Removes all of the elements of this collection that satisfy the given predicate. 
Errors or runtime exceptions thrown during iteration or by the predicate 
are relayed to the caller.

Interesting note:

The default implementation traverses all elements of the collection using its iterator(). 
Each matching element is removed using Iterator.remove().

From: https://docs.oracle.com/javase/8/docs/api/java/util/Collection.html#removeIf-java.util.function.Predicate-

How to get a matplotlib Axes instance to plot to?

You can either

fig, ax = plt.subplots()  #create figure and axes
candlestick(ax, quotes, ...)

or

candlestick(plt.gca(), quotes) #get the axis when calling the function

The first gives you more flexibility. The second is much easier if candlestick is the only thing you want to plot

Refresh or force redraw the fragment

Use the following code for refreshing fragment again:

FragmentTransaction ftr = getFragmentManager().beginTransaction();                          
ftr.detach(EnterYourFragmentName.this).attach(EnterYourFragmentName.this).commit();

Why call git branch --unset-upstream to fixup?

Issue: Your branch is based on 'origin/master', but the upstream is gone.

Solution: git branch --unset-upstream

What is the difference between Google App Engine and Google Compute Engine?

App Engine gives developers the ability to control Google Compute Engine cores, as well as provide a web-facing front end for Google Compute Engine data processing applications.

On the other hand, Compute Engine offers direct and complete operating system management of your virtual machines. To present your App, you're going to need resources, and Google Cloud Storage is ideal for storing your assets and data, whatever they're used for. You get fast data access with hosting around the globe. Reliability is guaranteed at a 99.95% up-time, and Google also provides the ability to back up and restore your data, and believe it or not, storage is unlimited.

You can manage your assets with Google Cloud Storage, storing, retrieving, displaying, and deleting them. You can also quickly read and write to flat datasheets that are kept in Cloud Storage. Next in the Google Cloud lineup is BigQuery. With BigQuery, you can analyze massive amounts of data, we're talking millions of records, within seconds. Access is handled via a straightforward UI, or a Representational State Transfer, or REST interface.

Data storage is, as you might suspect, not a problem, and scales to hundreds of TB. BigQuery is accessible via a host of client libraries, including those for Java, .NET, Python, Go, Ruby, PHP, and Javascript. A SQL-like syntax called NoSQL is available which can be accessed through these client libraries, or through a web user interface. Finally, let's talk about the Google Cloud platform database options, Cloud SQL and Cloud Datastore.

There is a major difference. Cloud SQL is for relational databases, primarily MySQL, whereas Cloud Datastore is for non-relational databases using noSQL. With Cloud SQL, you have the choice of either hosting in the US, Europe, or Asia, with 100 GB of storage, and 16 GB of RAM per database instance.

Cloud Datastore is available at no charge for up to 50 K read/write instructions per month and 1 GB of data stored also per month. There is a fee if you exceed these quotas, however. App Engine can also work with other lesser known, more targeted members of the Google Cloud platform, including the Cloud Endpoints for creating API backends, Google Prediction API for data analysis and trend forecasting, or the Google Translate API, for multilingual output.

While you can do a fair amount with App Engine on its own, It's potential skyrockets when you factor in its ability to work easily and efficiently with its fellow Google Cloud platform services.

How to measure time taken between lines of code in python?

I always prefer to check time in hours, minutes and seconds (%H:%M:%S) format:

from datetime import datetime
start = datetime.now()
# your code
end = datetime.now()
time_taken = end - start
print('Time: ',time_taken) 

output:

Time:  0:00:00.000019

How to get the date from jQuery UI datepicker

Use

var jsDate = $('#your_datepicker_id').datepicker('getDate');
if (jsDate !== null) { // if any date selected in datepicker
    jsDate instanceof Date; // -> true
    jsDate.getDate();
    jsDate.getMonth();
    jsDate.getFullYear();
}

APT command line interface-like yes/no input?

As you mentioned, the easiest way is to use raw_input() (or simply input() for Python 3). There is no built-in way to do this. From Recipe 577058:

import sys

def query_yes_no(question, default="yes"):
    """Ask a yes/no question via raw_input() and return their answer.

    "question" is a string that is presented to the user.
    "default" is the presumed answer if the user just hits <Enter>.
        It must be "yes" (the default), "no" or None (meaning
        an answer is required of the user).

    The "answer" return value is True for "yes" or False for "no".
    """
    valid = {"yes": True, "y": True, "ye": True,
             "no": False, "n": False}
    if default is None:
        prompt = " [y/n] "
    elif default == "yes":
        prompt = " [Y/n] "
    elif default == "no":
        prompt = " [y/N] "
    else:
        raise ValueError("invalid default answer: '%s'" % default)

    while True:
        sys.stdout.write(question + prompt)
        choice = raw_input().lower()
        if default is not None and choice == '':
            return valid[default]
        elif choice in valid:
            return valid[choice]
        else:
            sys.stdout.write("Please respond with 'yes' or 'no' "
                             "(or 'y' or 'n').\n")

Usage example:

>>> query_yes_no("Is cabbage yummier than cauliflower?")
Is cabbage yummier than cauliflower? [Y/n] oops
Please respond with 'yes' or 'no' (or 'y' or 'n').
Is cabbage yummier than cauliflower? [Y/n] [ENTER]
>>> True

>>> query_yes_no("Is cabbage yummier than cauliflower?", None)
Is cabbage yummier than cauliflower? [y/n] [ENTER]
Please respond with 'yes' or 'no' (or 'y' or 'n').
Is cabbage yummier than cauliflower? [y/n] y
>>> True

How can I keep Bootstrap popovers alive while being hovered?

        $(function() {
            $("[data-toggle = 'popover']").popover({
                placement: 'left',
                html: true,
                trigger: "  focus",
            }).on("mouseenter", function() {
                var _this = this;
                $(this).popover("show");
                $(this).siblings(".popover").on("mouseleave", function() {
                    $(_this).popover('hide');
                });
            }).on("mouseleave", function() {
                var _this = this;
                setTimeout(function() {
                    if (!$(".popover:hover").length) {
                        $(_this).popover("hide")
                    }
                }, 100);
            });
        }); 

How to Set Active Tab in jQuery Ui

Inside your function for the click action use

$( "#tabs" ).tabs({ active: # });

Where # is replaced by the tab index you want to select.

Edit: change from selected to active, selected is deprecated

How to filter array when object key value is in array

You can use Array#filter function and additional array for storing sorted values;

var recordsSorted = []

ids.forEach(function(e) {
    recordsSorted.push(records.filter(function(o) {
        return o.empid === e;
    }));
});

console.log(recordsSorted);

Result:

[ [ { empid: 1, fname: 'X', lname: 'Y' } ],
  [ { empid: 4, fname: 'C', lname: 'Y' } ],
  [ { empid: 5, fname: 'C', lname: 'Y' } ] ]

How to determine whether a Pandas Column contains a particular value

Suppose you dataframe looks like :

enter image description here

Now you want to check if filename "80900026941984" is present in the dataframe or not.

You can simply write :

if sum(df["filename"].astype("str").str.contains("80900026941984")) > 0:
    print("found")

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

if you have ID or any specific field in your item, you can use filter(). its act like Where().

<a class="btn" ng-click="remove(item)">Delete</a>

in controller:

$scope.remove = function(item) { 
  $scope.bdays = $scope.bdays.filter(function (element) {
                    return element.ID!=item.ID
                });
}

MySQL high CPU usage

If this server is visible to the outside world, It's worth checking if it's having lots of requests to connect from the outside world (i.e. people trying to break into it)

How to check the version before installing a package using apt-get?

Linux Mint, Debian 9, Ubuntu 16.04 and older:

Short info:

apt policy <package_name>

Detailed info (With Description and Depends):

apt show <package_name>

How to hide "Showing 1 of N Entries" with the dataTables.js library

Now, this seems to work:

$('#example').DataTable({
  "info": false
});

it hides that div, altogether

Converting two lists into a matrix

You can use np.c_

np.c_[[1,2,3], [4,5,6]]

It will give you:

np.array([[1,4], [2,5], [3,6]])

How to do a simple file search in cmd

dir /s *foo* searches in current folder and sub folders.

It finds directories as well as files.

where /s means(documentation):

/s Lists every occurrence of the specified file name within the specified directory and all subdirectories.

How to Convert UTC Date To Local time Zone in MySql Select Query

SELECT CONVERT_TZ() will work for that.but its not working for me.

Why, what error do you get?

SELECT CONVERT_TZ(displaytime,'GMT','MET');

should work if your column type is timestamp, or date

http://dev.mysql.com/doc/refman/5.0/en/date-and-time-functions.html#function_convert-tz

Test how this works:

SELECT CONVERT_TZ(a_ad_display.displaytime,'+00:00','+04:00');

Check your timezone-table

SELECT * FROM mysql.time_zone;
SELECT * FROM mysql.time_zone_name;

http://dev.mysql.com/doc/refman/5.5/en/time-zone-support.html

If those tables are empty, you have not initialized your timezone tables. According to link above you can use mysql_tzinfo_to_sql program to load the Time Zone Tables. Please try this

shell> mysql_tzinfo_to_sql /usr/share/zoneinfo

or if not working read more: http://dev.mysql.com/doc/refman/5.5/en/mysql-tzinfo-to-sql.html

How to show row number in Access query like ROW_NUMBER in SQL

One way to do this with MS Access is with a subquery but it does not have anything like the same functionality:

SELECT a.ID, 
       a.AText, 
       (SELECT Count(ID) 
        FROM table1 b WHERE b.ID <= a.ID 
        AND b.AText Like "*a*") AS RowNo
FROM Table1 AS a
WHERE a.AText Like "*a*"
ORDER BY a.ID;

Print the contents of a DIV

Although this has been said by @gabe, If you are using jQuery, you can use my printElement plugin.

There's a sample here, and more information about the plugin here.

The usage is rather straight forward, just grab an element with a jQuery selector and print it:

$("#myDiv").printElement();

I hope it helps!

Which MySQL datatype to use for an IP address?

Since IPv4 addresses are 4 byte long, you could use an INT (UNSIGNED) that has exactly 4 bytes:

`ipv4` INT UNSIGNED

And INET_ATON and INET_NTOA to convert them:

INSERT INTO `table` (`ipv4`) VALUES (INET_ATON("127.0.0.1"));
SELECT INET_NTOA(`ipv4`) FROM `table`;

For IPv6 addresses you could use a BINARY instead:

`ipv6` BINARY(16)

And use PHP’s inet_pton and inet_ntop for conversion:

'INSERT INTO `table` (`ipv6`) VALUES ("'.mysqli_real_escape_string(inet_pton('2001:4860:a005::68')).'")'
'SELECT `ipv6` FROM `table`'
$ipv6 = inet_pton($row['ipv6']);

How to display with n decimal places in Matlab

You can convert a number to a string with n decimal places using the SPRINTF command:

>> x = 1.23;
>> sprintf('%0.6f', x)

ans =

1.230000

>> x = 1.23456789;
>> sprintf('%0.6f', x)

ans =

1.234568

Sending email from Command-line via outlook without having to click send

Send SMS/Text Messages from Command Line with VBScript!

If VBA meets the rules for VB Script then it can be called from command line by simply placing it into a text file - in this case there's no need to specifically open Outlook.

I had a need to send automated text messages to myself from the command line, so I used the code below, which is just a compressed version of @Geoff's answer above.

Most mobile phone carriers worldwide provide an email address "version" of your mobile phone number. For example in Canada with Rogers or Chatr Wireless, an email sent to <YourPhoneNumber> @pcs.rogers.com will be immediately delivered to your Rogers/Chatr phone as a text message.

* You may need to "authorize" the first message on your phone, and some carriers may charge an additional fee for theses message although as far as I know, all Canadian carriers provide this little-known service for free. Check your carrier's website for details.

There are further instructions and various compiled lists of worldwide carrier's Email-to-Text addresses available online such as this and this and this.


Code & Instructions

  1. Copy the code below and paste into a new file in your favorite text editor.
  2. Save the file with any name with a .VBS extension, such as TextMyself.vbs.

That's all!
Just double-click the file to send a test message, or else run it from a batch file using START.

Sub SendMessage()
    Const EmailToSMSAddy = "[email protected]"
    Dim objOutlookRecip
    With CreateObject("Outlook.Application").CreateItem(0)
        Set objOutlookRecip = .Recipients.Add(EmailToSMSAddy)
        objOutlookRecip.Type = 1
        .Subject = "The computer needs your attention!"
        .Body = "Go see why Windows Command Line is texting you!"
        .Save
        .Send
    End With
End Sub

Example Batch File Usage:

START x:\mypath\TextMyself.vbs

Of course there are endless possible ways this could be adapted and customized to suit various practical or creative needs.

Twitter Bootstrap - add top space between rows

<div class="row row-padding">

simple code

Python equivalent of a given wget command

I had to do something like this on a version of linux that didn't have the right options compiled into wget. This example is for downloading the memory analysis tool 'guppy'. I'm not sure if it's important or not, but I kept the target file's name the same as the url target name...

Here's what I came up with:

python -c "import requests; r = requests.get('https://pypi.python.org/packages/source/g/guppy/guppy-0.1.10.tar.gz') ; open('guppy-0.1.10.tar.gz' , 'wb').write(r.content)"

That's the one-liner, here's it a little more readable:

import requests
fname = 'guppy-0.1.10.tar.gz'
url = 'https://pypi.python.org/packages/source/g/guppy/' + fname
r = requests.get(url)
open(fname , 'wb').write(r.content)

This worked for downloading a tarball. I was able to extract the package and download it after downloading.

EDIT:

To address a question, here is an implementation with a progress bar printed to STDOUT. There is probably a more portable way to do this without the clint package, but this was tested on my machine and works fine:

#!/usr/bin/env python

from clint.textui import progress
import requests

fname = 'guppy-0.1.10.tar.gz'
url = 'https://pypi.python.org/packages/source/g/guppy/' + fname

r = requests.get(url, stream=True)
with open(fname, 'wb') as f:
    total_length = int(r.headers.get('content-length'))
    for chunk in progress.bar(r.iter_content(chunk_size=1024), expected_size=(total_length/1024) + 1): 
        if chunk:
            f.write(chunk)
            f.flush()

How to add a "sleep" or "wait" to my Lua Script?

This homebrew function have precision down to a 10th of a second or less.

function sleep (a) 
    local sec = tonumber(os.clock() + a); 
    while (os.clock() < sec) do 
    end 
end

django: TypeError: 'tuple' object is not callable

There is comma missing in your tuple.

insert the comma between the tuples as shown:

pack_size = (('1', '1'),('3', '3'),(b, b),(h, h),(d, d), (e, e),(r, r))

Do the same for all

What is the C# equivalent of friend?

There isn't a 'friend' keyword in C# but one option for testing private methods is to use System.Reflection to get a handle to the method. This will allow you to invoke private methods.

Given a class with this definition:

public class Class1
{
    private int CallMe()
    {
        return 1;
    }
}

You can invoke it using this code:

Class1 c = new Class1();
Type class1Type = c.GetType();
MethodInfo callMeMethod = class1Type.GetMethod("CallMe", BindingFlags.Instance | BindingFlags.NonPublic);

int result = (int)callMeMethod.Invoke(c, null);

Console.WriteLine(result);

If you are using Visual Studio Team System then you can get VS to automatically generate a proxy class with private accessors in it by right clicking the method and selecting "Create Unit Tests..."

Print page numbers on pages when printing html

Can you try this, you can use content: counter(page);

     @page {
       @bottom-left {
            content: counter(page) "/" counter(pages);
        }
     }

Ref: http://www.w3.org/TR/CSS21/generate.html#counters

http://www.princexml.com/doc/9.0/page-numbers/

What is the problem with shadowing names defined in outer scopes?

Do this:

data = [4, 5, 6]

def print_data():
    global data
    print(data)

print_data()

Android - How to regenerate R class?

My problem was errors in my XML files. Errors aren't always automatically detected in the Android Common XML Editor or Android Common Manifest Editor, so try using the regular text editor instead. For example, somehow some random gibberish from a .java file had been inserted into my manifest and strings.xml files.

Right click on any XML files (most likely in the /res folder or AndroidManifest.xml) and click "Open With," then select "Text editor." Make sure everything looks good and then save. Also, make sure to enable "Build Automatically" for your project. I had deleted my R.java file and it was rebuilt from scratch, so no need to restore it from local history.

How does OAuth 2 protect against things like replay attacks using the Security Token?

Figure 1, lifted from RFC6750:

     +--------+                               +---------------+
     |        |--(A)- Authorization Request ->|   Resource    |
     |        |                               |     Owner     |
     |        |<-(B)-- Authorization Grant ---|               |
     |        |                               +---------------+
     |        |
     |        |                               +---------------+
     |        |--(C)-- Authorization Grant -->| Authorization |
     | Client |                               |     Server    |
     |        |<-(D)----- Access Token -------|               |
     |        |                               +---------------+
     |        |
     |        |                               +---------------+
     |        |--(E)----- Access Token ------>|    Resource   |
     |        |                               |     Server    |
     |        |<-(F)--- Protected Resource ---|               |
     +--------+                               +---------------+

.Net HttpWebRequest.GetResponse() raises exception when http status code 400 (bad request) is returned

I had similar issues when trying to connect to Google's OAuth2 service.

I ended up writing the POST manually, not using WebRequest, like this:

TcpClient client = new TcpClient("accounts.google.com", 443);
Stream netStream = client.GetStream();
SslStream sslStream = new SslStream(netStream);
sslStream.AuthenticateAsClient("accounts.google.com");

{
    byte[] contentAsBytes = Encoding.ASCII.GetBytes(content.ToString());

    StringBuilder msg = new StringBuilder();
    msg.AppendLine("POST /o/oauth2/token HTTP/1.1");
    msg.AppendLine("Host: accounts.google.com");
    msg.AppendLine("Content-Type: application/x-www-form-urlencoded");
    msg.AppendLine("Content-Length: " + contentAsBytes.Length.ToString());
    msg.AppendLine("");
    Debug.WriteLine("Request");
    Debug.WriteLine(msg.ToString());
    Debug.WriteLine(content.ToString());

    byte[] headerAsBytes = Encoding.ASCII.GetBytes(msg.ToString());
    sslStream.Write(headerAsBytes);
    sslStream.Write(contentAsBytes);
}

Debug.WriteLine("Response");

StreamReader reader = new StreamReader(sslStream);
while (true)
{  // Print the response line by line to the debug stream for inspection.
    string line = reader.ReadLine();
    if (line == null) break;
    Debug.WriteLine(line);
}

The response that gets written to the response stream contains the specific error text that you're after.

In particular, my problem was that I was putting endlines between url-encoded data pieces. When I took them out, everything worked. You might be able to use a similar technique to connect to your service and read the actual response error text.

Adding event listeners to dynamically added elements using jQuery

When adding new element with jquery plugin calls, you can do like the following:

$('<div>...</div>').hoverCard(function(){...}).appendTo(...)

How to set a hidden value in Razor

There is a Hidden helper alongside HiddenFor which lets you set the value.

@Html.Hidden("RequiredProperty", "default")

EDIT Based on the edit you've made to the question, you could do this, but I believe you're moving into territory where it will be cheaper and more effective, in the long run, to fight for making the code change. As has been said, even by yourself, the controller or view model should be setting the default.

This code:

<ul>
@{
        var stacks = new System.Diagnostics.StackTrace().GetFrames();
        foreach (var frame in stacks)
        {
            <li>@frame.GetMethod().Name - @frame.GetMethod().DeclaringType</li>
        }
}
</ul>

Will give output like this:

Execute - ASP._Page_Views_ViewDirectoryX__SubView_cshtml
ExecutePageHierarchy - System.Web.WebPages.WebPageBase
ExecutePageHierarchy - System.Web.Mvc.WebViewPage
ExecutePageHierarchy - System.Web.WebPages.WebPageBase
RenderView - System.Web.Mvc.RazorView
Render - System.Web.Mvc.BuildManagerCompiledView
RenderPartialInternal - System.Web.Mvc.HtmlHelper
RenderPartial - System.Web.Mvc.Html.RenderPartialExtensions
Execute - ASP._Page_Views_ViewDirectoryY__MainView_cshtml

So assuming the MVC framework will always go through the same stack, you can grab var frame = stacks[8]; and use the declaring type to determine who your parent view is, and then use that determination to set (or not) the default value. You could also walk the stack instead of directly grabbing [8] which would be safer but even less efficient.

What .NET collection provides the fastest search

Have you considered List.BinarySearch(item)?

You said that your large collection is already sorted so this seems like the perfect opportunity? A hash would definitely be the fastest, but this brings about its own problems and requires a lot more overhead for storage.

Way to ng-repeat defined number of times instead of repeating over array?

I needed a more dynamic solution to this - where I could increment the repeat.

HTML

<div ng-repeat="n in newUserCount">
<input type="text" value="" name="newuser{{n}}"/>
</div>

Duplicator Control

<span class="helper" ng-click="duplicateUser()">
Create another user with the same permissions
</span>

JS

 $scope.newUserCount = Array('1');
var primaryValue = 1;
$scope.duplicateUser = function()
{
    primaryValue++;
    $scope.newUserCount.push(primaryValue)
}

Java Project: Failed to load ApplicationContext

I had the same problem, and I was using the following plugin for tests:

<plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-surefire-plugin</artifactId>
    <version>2.9</version>
    <configuration>
        <useFile>true</useFile>
        <includes>
            <include>**/*Tests.java</include>
            <include>**/*Test.java</include>
        </includes>
        <excludes>
            <exclude>**/Abstract*.java</exclude>
        </excludes>
        <junitArtifactName>junit:junit</junitArtifactName>
        <parallel>methods</parallel>
        <threadCount>10</threadCount>
    </configuration>
</plugin>

The test were running fine in the IDE (eclipse sts), but failed when using command mvn test.

After a lot of trial and error, I figured the solution was to remove parallel testing, the following two lines from the plugin configuration above:

    <parallel>methods</parallel>
    <threadCount>10</threadCount>

Hope that this helps someone out!

Confirm deletion in modal / dialog using Twitter Bootstrap?

I can easily handle this type of task using bootbox.js library. At first you need to include bootbox JS file. Then in your event handler function simply write following code:

    bootbox.confirm("Are you sure to want to delete , function(result) {

    //here result will be true
    // delete process code goes here

    });

Offical bootboxjs site

Inject service in app.config

Easiest way: $injector = angular.element(document.body).injector()

Then use that to run invoke() or get()

The OutputPath property is not set for this project

I had exact same error after adding a new configuration via ConfigurationManager in Visual Studio.

It turned out when the 'Production' configuration was added for the whole solution (and each project) the OutputPath element was not added to the .csproj files.

To fix, I went to the Build tab in project properties, changed OutputPath from \bin\Production\ to \bin\Production (deleted trailing \) and saved changes. This forced creation of the OutputPath element in the .csproj file and the project has built successfully.

Sounds like a glitch to me.

Setting POST variable without using form

you can do it using ajax or by sending http headers+content like:

POST /xyz.php HTTP/1.1
Host: www.mysite.com
User-Agent: Mozilla/4.0
Content-Length: 27
Content-Type: application/x-www-form-urlencoded

userid=joe&password=guessme

How do I add a linker or compile flag in a CMake file?

Suppose you want to add those flags (better to declare them in a constant):

SET(GCC_COVERAGE_COMPILE_FLAGS "-fprofile-arcs -ftest-coverage")
SET(GCC_COVERAGE_LINK_FLAGS    "-lgcov")

There are several ways to add them:

  1. The easiest one (not clean, but easy and convenient, and works only for compile flags, C & C++ at once):

    add_definitions(${GCC_COVERAGE_COMPILE_FLAGS})
    
  2. Appending to corresponding CMake variables:

    SET(CMAKE_CXX_FLAGS  "${CMAKE_CXX_FLAGS} ${GCC_COVERAGE_COMPILE_FLAGS}")
    SET(CMAKE_EXE_LINKER_FLAGS  "${CMAKE_EXE_LINKER_FLAGS} ${GCC_COVERAGE_LINK_FLAGS}")
    
  3. Using target properties, cf. doc CMake compile flag target property and need to know the target name.

    get_target_property(TEMP ${THE_TARGET} COMPILE_FLAGS)
    if(TEMP STREQUAL "TEMP-NOTFOUND")
      SET(TEMP "") # Set to empty string
    else()
      SET(TEMP "${TEMP} ") # A space to cleanly separate from existing content
    endif()
    # Append our values
    SET(TEMP "${TEMP}${GCC_COVERAGE_COMPILE_FLAGS}" )
    set_target_properties(${THE_TARGET} PROPERTIES COMPILE_FLAGS ${TEMP} )
    

Right now I use method 2.

Calculating distance between two geographic locations

http://developer.android.com/reference/android/location/Location.html

Look into distanceTo

Returns the approximate distance in meters between this location and the given location. Distance is defined using the WGS84 ellipsoid.

or distanceBetween

Computes the approximate distance in meters between two locations, and optionally the initial and final bearings of the shortest path between them. Distance and bearing are defined using the WGS84 ellipsoid.

You can create a Location object from a latitude and longitude:

Location locationA = new Location("point A");

locationA.setLatitude(latA);
locationA.setLongitude(lngA);

Location locationB = new Location("point B");

locationB.setLatitude(latB);
locationB.setLongitude(lngB);

float distance = locationA.distanceTo(locationB);

or

private double meterDistanceBetweenPoints(float lat_a, float lng_a, float lat_b, float lng_b) {
    float pk = (float) (180.f/Math.PI);

    float a1 = lat_a / pk;
    float a2 = lng_a / pk;
    float b1 = lat_b / pk;
    float b2 = lng_b / pk;

    double t1 = Math.cos(a1) * Math.cos(a2) * Math.cos(b1) * Math.cos(b2);
    double t2 = Math.cos(a1) * Math.sin(a2) * Math.cos(b1) * Math.sin(b2);
    double t3 = Math.sin(a1) * Math.sin(b1);
    double tt = Math.acos(t1 + t2 + t3);
   
    return 6366000 * tt;
}

MySQl Error #1064

maybe you forgot to add ";" after this line of code:

`quantity` INT NOT NULL)

File path to resource in our war/WEB-INF folder?

There's a couple ways of doing this. As long as the WAR file is expanded (a set of files instead of one .war file), you can use this API:

ServletContext context = getContext();
String fullPath = context.getRealPath("/WEB-INF/test/foo.txt");

http://tomcat.apache.org/tomcat-5.5-doc/servletapi/javax/servlet/ServletContext.html#getRealPath(java.lang.String)

That will get you the full system path to the resource you are looking for. However, that won't work if the Servlet Container never expands the WAR file (like Tomcat). What will work is using the ServletContext's getResource methods.

ServletContext context = getContext();
URL resourceUrl = context.getResource("/WEB-INF/test/foo.txt");

or alternatively if you just want the input stream:

InputStream resourceContent = context.getResourceAsStream("/WEB-INF/test/foo.txt");

http://tomcat.apache.org/tomcat-5.5-doc/servletapi/javax/servlet/ServletContext.html#getResource(java.lang.String)

The latter approach will work no matter what Servlet Container you use and where the application is installed. The former approach will only work if the WAR file is unzipped before deployment.

EDIT: The getContext() method is obviously something you would have to implement. JSP pages make it available as the context field. In a servlet you get it from your ServletConfig which is passed into the servlet's init() method. If you store it at that time, you can get your ServletContext any time you want after that.

Good PHP ORM Library?

Try Doctrine2. It's probably the most powerful ORM tool for PHP. I'm mentioning it separately from Doctrine 1, because it's a completely different piece of software. It's been rewritten from scratch, is still in beta phase, but it's usable now and developed.

It's a very complex ORM, but well designed. Lot of magic from original Doctrine 1 disappeared. It provides a complete solution, and you can write your own ORM on top of Doctrine2 or use just one of its layers.

Getting Exception(org.apache.poi.openxml4j.exception - no content type [M1.13]) when reading xlsx file using Apache POI?

You get this exact error should you pass an old school .xls file into this API. Save the .xls as a .xlsx and then it will work.

Scroll to the top of the page using JavaScript?

When top scroll is top less than limit bottom and bottom to top scroll Header is Sticky. Below See Fiddle Example.

var lastScroll = 0;

$(document).ready(function($) {

$(window).scroll(function(){

 setTimeout(function() { 
    var scroll = $(window).scrollTop();
    if (scroll > lastScroll) {

        $("header").removeClass("menu-sticky");

    } 
    if (scroll == 0) {
    $("header").removeClass("menu-sticky");

    }
    else if (scroll < lastScroll - 5) {


        $("header").addClass("menu-sticky");

    }
    lastScroll = scroll;
    },0);
    });
   });

https://jsfiddle.net/memdumusaib/d52xcLm3/

Start systemd service after specific service?

In the .service file under the [Unit] section:

[Unit]
Description=My Website
After=syslog.target network.target mongodb.service

The important part is the mongodb.service

The manpage describes it however due to formatting it's not as clear on first sight

systemd.unit - well formatted

systemd.unit - not so well formatted

How to find the sum of an array of numbers

var arr = [1,2,3,4];
var total=0;
for(var i in arr) { total += arr[i]; }

Why do I get "Cannot redirect after HTTP headers have been sent" when I call Response.Redirect()?

If you get Cannot redirect after HTTP headers have been sent then try this below code.

HttpContext.Current.Server.ClearError();
// Response.Headers.Clear();
HttpContext.Current.Response.Redirect("/Home/Login",false);

SQL WHERE condition is not equal to?

WHERE id <> 2 should work fine...Is that what you are after?

How to convert int to date in SQL Server 2008

Reading through this helps solve a similar problem. The data is in decimal datatype - [DOB] [decimal](8, 0) NOT NULL - eg - 19700109. I want to get at the month. The solution is to combine SUBSTRING with CONVERT to VARCHAR.

    SELECT [NUM]
       ,SUBSTRING(CONVERT(VARCHAR, DOB),5,2) AS mob
    FROM [Dbname].[dbo].[Tablename] 

How to select a node of treeview programmatically in c#?

private void btn_CollapseAllAndExpandFirstLevelUnderRoot(object sender, EventArgs e)

{
    //this example collapses everything, then expands the first level under the root node.

    tv_myTreeView.CollapseAll();
    TreeNode tn =  tv_myTreeView.Nodes[0];
    tn.Expand();
}

How can I pipe stderr, and not stdout?

It's much easier to visualize things if you think about what's really going on with "redirects" and "pipes." Redirects and pipes in bash do one thing: modify where the process file descriptors 0, 1, and 2 point to (see /proc/[pid]/fd/*).

When a pipe or "|" operator is present on the command line, the first thing to happen is that bash creates a fifo and points the left side command's FD 1 to this fifo, and points the right side command's FD 0 to the same fifo.

Next, the redirect operators for each side are evaluated from left to right, and the current settings are used whenever duplication of the descriptor occurs. This is important because since the pipe was set up first, the FD1 (left side) and FD0 (right side) are already changed from what they might normally have been, and any duplication of these will reflect that fact.

Therefore, when you type something like the following:

command 2>&1 >/dev/null | grep 'something'

Here is what happens, in order:

  1. a pipe (fifo) is created. "command FD1" is pointed to this pipe. "grep FD0" also is pointed to this pipe
  2. "command FD2" is pointed to where "command FD1" currently points (the pipe)
  3. "command FD1" is pointed to /dev/null

So, all output that "command" writes to its FD 2 (stderr) makes its way to the pipe and is read by "grep" on the other side. All output that "command" writes to its FD 1 (stdout) makes its way to /dev/null.

If instead, you run the following:

command >/dev/null 2>&1 | grep 'something'

Here's what happens:

  1. a pipe is created and "command FD 1" and "grep FD 0" are pointed to it
  2. "command FD 1" is pointed to /dev/null
  3. "command FD 2" is pointed to where FD 1 currently points (/dev/null)

So, all stdout and stderr from "command" go to /dev/null. Nothing goes to the pipe, and thus "grep" will close out without displaying anything on the screen.

Also note that redirects (file descriptors) can be read-only (<), write-only (>), or read-write (<>).

A final note. Whether a program writes something to FD1 or FD2, is entirely up to the programmer. Good programming practice dictates that error messages should go to FD 2 and normal output to FD 1, but you will often find sloppy programming that mixes the two or otherwise ignores the convention.

The create-react-app imports restriction outside of src directory

I have had to overcome this same issue in Truffle. The solution was as follows:

ince Create-React-App's default behavior disallows importing files from outside of the src folder, we need to bring the contracts in our build folder inside src. We can copy and paste them every time we compile our contracts, but a better way is to simply configure Truffle to put the files there.

In the truffle-config.js file, replace the contents with the following:

const path = require("path");

module.exports = {
  contracts_build_directory: path.join(__dirname, "client/src/contracts")
};

I don't know if this helps you, but I know I found your question when I had the same issue in Truffle, and this might help someone else.

What is Haskell used for in the real world?

Haskell is a general purpose programming language. It can be used for anything you use any other language to do. You aren't limited by anything but your own imagination. As for what it's suited for? Well, pretty much everything. There are few tasks in which a functional language does not excel.

And yes, I'm the Rayne from Dreamincode. :)

I would also like to mention that, in case you haven't read the Wikipedia page, functional programming is a paradigm like Object Oriented programming is a paradigm. Just in case you didn't know. Haskell is also functional in the sense that it works; it works quite well at that.

Just because a language isn't an Object Oriented language doesn't mean the language is limited by anything. Haskell is a general-purpose programming language, and is just as general purpose as Java.

How to vertically align text in input type="text"?

I found this question while looking for a solution to my own problem. The previous answers rely on padding to make the text appear at the top or bottom of the input or use a combination of height and line-height to align the text to the vertical middle.

Here is an alternative solution to making the text appear in the middle using a div and positioning. Check out the jsfiddle.

<style type="text/css">
    div {
        display: inline-block;
        height: 300px;
        position: relative;
        width: 500px;
    }

    input {
        height: 100%;
        position: absolute;
        text-align: center; /* Optional */
        width: 100%;
    }
</style>

<div>
    <input type="text" value="Hello world!" />
</div>

Cannot open Windows.h in Microsoft Visual Studio

For my case, I had to right click the solution and click "Retarget Projects". In my case I retargetted to Windows SDK version 10.0.1777.0 and Platform Toolset v142. I also had to change "Windows.h"to<windows.h>

I am running Visual Studio 2019 version 16.25 on a windows 10 machine

How to delete files older than X hours

-mmin is for minutes.

Try looking at the man page.

man find

for more types.

Regex replace (in Python) - a simpler way?

>>> import re
>>> s = "start foo end"
>>> s = re.sub("foo", "replaced", s)
>>> s
'start replaced end'
>>> s = re.sub("(?<= )(.+)(?= )", lambda m: "can use a callable for the %s text too" % m.group(1), s)
>>> s
'start can use a callable for the replaced text too end'
>>> help(re.sub)
Help on function sub in module re:

sub(pattern, repl, string, count=0)
    Return the string obtained by replacing the leftmost
    non-overlapping occurrences of the pattern in string by the
    replacement repl.  repl can be either a string or a callable;
    if a callable, it's passed the match object and must return
    a replacement string to be used.

How do I uninstall a package installed using npm link?

"npm install" replaces all dependencies in your node_modules installed with "npm link" with versions from npmjs (specified in your package.json)

Set form backcolor to custom color

With Winforms you can use Form.BackColor to do this.
From within the Form's code:

BackColor = Color.LightPink;

If you mean a WPF Window you can use the Background property.
From within the Window's code:

Background = Brushes.LightPink;

Syntax for creating a two-dimensional array in Java

In Java, a two-dimensional array can be declared as the same as a one-dimensional array. In a one-dimensional array you can write like

  int array[] = new int[5];

where int is a data type, array[] is an array declaration, and new array is an array with its objects with five indexes.

Like that, you can write a two-dimensional array as the following.

  int array[][];
  array = new int[3][4];

Here array is an int data type. I have firstly declared on a one-dimensional array of that types, then a 3 row and 4 column array is created.

In your code

int[][] multD = new int[5][];
multD[0] = new int[10];

means that you have created a two-dimensional array, with five rows. In the first row there are 10 columns. In Java you can select the column size for every row as you desire.

Displaying a vector of strings in C++

You have to insert the elements using the insert method present in vectors STL, check the below program to add the elements to it, and you can use in the same way in your program.

#include <iostream>
#include <vector>
#include <string.h>

int main ()
{
  std::vector<std::string> myvector ;
  std::vector<std::string>::iterator it;

   it = myvector.begin();
  std::string myarray [] = { "Hi","hello","wassup" };
  myvector.insert (myvector.begin(), myarray, myarray+3);

  std::cout << "myvector contains:";
  for (it=myvector.begin(); it<myvector.end(); it++)
    std::cout << ' ' << *it;
    std::cout << '\n';

  return 0;
}

how to remove new lines and returns from php string?

Replace a string :

$str = str_replace("\n", '', $str);

u using also like, (%n, %t, All Special characters, numbers, char,. etc)

which means any thing u can replace in a string.

How to use the command update-alternatives --config java

Have a look at https://wiki.debian.org/JavaPackage At the bottom of this page an other method is descibed using a command from the java-common package

oracle SQL how to remove time from date

We can use TRUNC function in Oracle DB. Here is an example.

SELECT TRUNC(TO_DATE('01 Jan 2018 08:00:00','DD-MON-YYYY HH24:MI:SS')) FROM DUAL

Output: 1/1/2018

React-Redux: Actions must be plain objects. Use custom middleware for async actions

For future seekers who might have dropped simple details like me, in my case I just have forgotten to call my action function with parentheses.

actions.js:

export function addNewComponent() {
  return {
    type: ADD_NEW_COMPONENT,
  };
}

myComponent.js:

import React, { useEffect } from 'react';
import { addNewComponent } from '../../redux/actions';

  useEffect(() => {
    dispatch(refreshAllComponents); // <= Here was what I've missed.
  }, []);

I've forgotten to dispatch the action function with (). So doing this solved my issue.

  useEffect(() => {
    dispatch(refreshAllComponents());
  }, []);

Again this might have nothing to do with OP's problem, but I hope I helps people with the same problem as mine.

Align nav-items to right side in bootstrap-4

In last versions, it is easier. Just put a ml-auto class in the ul like so:

<ul class="nav navbar-nav ml-auto">

Hadoop MapReduce: Strange Result when Storing Previous Value in Memory in a Reduce Class (Java)

It is very inefficient to store all values in memory, so the objects are reused and loaded one at a time. See this other SO question for a good explanation. Summary:

[...] when looping through the Iterable value list, each Object instance is re-used, so it only keeps one instance around at a given time.

Cannot find pkg-config error

Try

Writing to an Excel spreadsheet

CSV stands for comma separated values. CSV is like a text file and can be created simply by adding the .CSV extension

for example write this code:

f = open('example.csv','w')
f.write("display,variable x")
f.close()

you can open this file with excel.

How to embed images in html email

I would strongly recommend using a library like PHPMailer to send emails.
It's easier and handles most of the issues automatically for you.

Regarding displaying embedded (inline) images, here's what's on their documentation:

Inline Attachments

There is an additional way to add an attachment. If you want to make a HTML e-mail with images incorporated into the desk, it's necessary to attach the image and then link the tag to it. For example, if you add an image as inline attachment with the CID my-photo, you would access it within the HTML e-mail with <img src="cid:my-photo" alt="my-photo" />.

In detail, here is the function to add an inline attachment:

$mail->AddEmbeddedImage(filename, cid, name);
//By using this function with this example's value above, results in this code:
$mail->AddEmbeddedImage('my-photo.jpg', 'my-photo', 'my-photo.jpg ');

To give you a more complete example of how it would work:

<?php
require_once('../class.phpmailer.php');
$mail = new PHPMailer(true); // the true param means it will throw exceptions on     errors, which we need to catch

$mail->IsSMTP(); // telling the class to use SMTP

try {
  $mail->Host       = "mail.yourdomain.com"; // SMTP server
  $mail->Port       = 25;                    // set the SMTP port
  $mail->SetFrom('[email protected]', 'First Last');
  $mail->AddAddress('[email protected]', 'John Doe');
  $mail->Subject = 'PHPMailer Test';

  $mail->AddEmbeddedImage("rocks.png", "my-attach", "rocks.png");
  $mail->Body = 'Your <b>HTML</b> with an embedded Image: <img src="cid:my-attach"> Here is an image!';

  $mail->AddAttachment('something.zip'); // this is a regular attachment (Not inline)
  $mail->Send();
  echo "Message Sent OK<p></p>\n";
} catch (phpmailerException $e) {
  echo $e->errorMessage(); //Pretty error messages from PHPMailer
} catch (Exception $e) {
  echo $e->getMessage(); //Boring error messages from anything else!
}
?>

Edit:

Regarding your comment, you asked how to send HTML email with embedded images, so I gave you an example of how to do that.
The library I told you about can send emails using a lot of methods other than SMTP.
Take a look at the PHPMailer Example page for other examples.

One way or the other, if you don't want to send the email in the ways supported by the library, you can (should) still use the library to build the message, then you send it the way you want.

For example:

You can replace the line that send the email:

$mail->Send();

With this:

$mime_message = $mail->CreateBody(); //Retrieve the message content
echo $mime_message; // Echo it to the screen or send it using whatever method you want

Hope that helps. Let me know if you run into trouble using it.

How can I load storyboard programmatically from class?

Swift 3

let storyboard = UIStoryboard(name: "Main", bundle: nil)
let vc = storyboard.instantiateViewController(withIdentifier: "viewController")
self.navigationController!.pushViewController(vc, animated: true)

Swift 2

let storyboard = UIStoryboard(name: "Main", bundle: nil)
let vc = storyboard.instantiateViewControllerWithIdentifier("viewController")
self.navigationController!.pushViewController(vc, animated: true)

Prerequisite

Assign a Storyboard ID to your view controller.

Storyboard ID

IB > Show the Identity inspector > Identity > Storyboard ID

Swift (legacy)

let storyboard = UIStoryboard(name: "Main", bundle: nil)
let vc = storyboard.instantiateViewControllerWithIdentifier("viewController") as? UIViewController
self.navigationController!.pushViewController(vc!, animated: true)

Edit: Swift 2 suggested in a comment by Fred A.

if you want to use without any navigationController you have to use like following :

    let Storyboard  = UIStoryboard(name: "Main", bundle: nil)
    let vc = Storyboard.instantiateViewController(withIdentifier: "viewController")
    present(vc , animated: true , completion: nil)

How to invoke function from external .c file in C?

you shouldn't include c-files in other c-files. Instead create a header file where the function is declared that you want to call. Like so: file ClasseAusiliaria.h:

int addizione(int a, int b); // this tells the compiler that there is a function defined and the linker will sort the right adress to call out.

In your Main.c file you can then include the newly created header file:

#include <stdlib.h>
#include <stdio.h>
#include <ClasseAusiliaria.h>

int main(void)
{
    int risultato;
    risultato = addizione(5,6);
    printf("%d\n",risultato);
}

How to match hyphens with Regular Expression?

Is this what you are after?

MatchCollection matches = Regex.Matches(mystring, "-");

How to resolve Value cannot be null. Parameter name: source in linq?

System.ArgumentNullException: Value cannot be null. Parameter name: value

This error message is not very helpful!

You can get this error in many different ways. The error may not always be with the parameter name: value. It could be whatever parameter name is being passed into a function.

As a generic way to solve this, look at the stack trace or call stack:

Test method GetApiModel threw exception: 
System.ArgumentNullException: Value cannot be null.
Parameter name: value
    at Newtonsoft.Json.JsonConvert.DeserializeObject(String value, Type type, JsonSerializerSettings settings)

You can see that the parameter name value is the first parameter for DeserializeObject. This lead me to check my AutoMapper mapping where we are deserializing a JSON string. That string is null in my database.

You can change the code to check for null.

What is the difference between 'classic' and 'integrated' pipeline mode in IIS7?

Classic mode (the only mode in IIS6 and below) is a mode where IIS only works with ISAPI extensions and ISAPI filters directly. In fact, in this mode, ASP.NET is just an ISAPI extension (aspnet_isapi.dll) and an ISAPI filter (aspnet_filter.dll). IIS just treats ASP.NET as an external plugin implemented in ISAPI and works with it like a black box (and only when it's needs to give out the request to ASP.NET). In this mode, ASP.NET is not much different from PHP or other technologies for IIS.

Integrated mode, on the other hand, is a new mode in IIS7 where IIS pipeline is tightly integrated (i.e. is just the same) as ASP.NET request pipeline. ASP.NET can see every request it wants to and manipulate things along the way. ASP.NET is no longer treated as an external plugin. It's completely blended and integrated in IIS. In this mode, ASP.NET HttpModules basically have nearly as much power as an ISAPI filter would have had and ASP.NET HttpHandlers can have nearly equivalent capability as an ISAPI extension could have. In this mode, ASP.NET is basically a part of IIS.

Changing every value in a hash in Ruby

my_hash.each do |key, value|
  my_hash[key] = "%#{value}%"
end

C Linking Error: undefined reference to 'main'

You're not including the C file that contains main() when compiling, so the linker isn't seeing it.

You need to add it:

$ gcc -o runexp runexp.c scd.o data_proc.o -lm -fopenmp

How to do vlookup and fill down (like in Excel) in R?

If I understand your question correctly, here are four methods to do the equivalent of Excel's VLOOKUP and fill down using R:

# load sample data from Q
hous <- read.table(header = TRUE, 
                   stringsAsFactors = FALSE, 
text="HouseType HouseTypeNo
Semi            1
Single          2
Row             3
Single          2
Apartment       4
Apartment       4
Row             3")

# create a toy large table with a 'HouseType' column 
# but no 'HouseTypeNo' column (yet)
largetable <- data.frame(HouseType = as.character(sample(unique(hous$HouseType), 1000, replace = TRUE)), stringsAsFactors = FALSE)

# create a lookup table to get the numbers to fill
# the large table
lookup <- unique(hous)
  HouseType HouseTypeNo
1      Semi           1
2    Single           2
3       Row           3
5 Apartment           4

Here are four methods to fill the HouseTypeNo in the largetable using the values in the lookup table:

First with merge in base:

# 1. using base 
base1 <- (merge(lookup, largetable, by = 'HouseType'))

A second method with named vectors in base:

# 2. using base and a named vector
housenames <- as.numeric(1:length(unique(hous$HouseType)))
names(housenames) <- unique(hous$HouseType)

base2 <- data.frame(HouseType = largetable$HouseType,
                    HouseTypeNo = (housenames[largetable$HouseType]))

Third, using the plyr package:

# 3. using the plyr package
library(plyr)
plyr1 <- join(largetable, lookup, by = "HouseType")

Fourth, using the sqldf package

# 4. using the sqldf package
library(sqldf)
sqldf1 <- sqldf("SELECT largetable.HouseType, lookup.HouseTypeNo
FROM largetable
INNER JOIN lookup
ON largetable.HouseType = lookup.HouseType")

If it's possible that some house types in largetable do not exist in lookup then a left join would be used:

sqldf("select * from largetable left join lookup using (HouseType)")

Corresponding changes to the other solutions would be needed too.

Is that what you wanted to do? Let me know which method you like and I'll add commentary.

delete image from folder PHP

There are a few routes. One, the most simple, would involve making that into a form; when it submits you react to POST data and delete the image using unlink

DISCLAIMER: This is not secure. An attacker could use this code to delete any file on your server. You must expand on this demonstration code to add some measure of security, otherwise you can expect bad things.

Each image's display markup would contain a form something like this:

echo '<form method="post">';
  echo '<input type="hidden" value="'.$file.'" name="delete_file" />';
  echo '<input type="submit" value="Delete image" />';
echo '</form>';

...and at at the top of that same PHP file:

if (array_key_exists('delete_file', $_POST)) {
  $filename = $_POST['delete_file'];
  if (file_exists($filename)) {
    unlink($filename);
    echo 'File '.$filename.' has been deleted';
  } else {
    echo 'Could not delete '.$filename.', file does not exist';
  }
}
// existing code continues below...

You can elaborate on this by using javascript: instead of submitting the form, you could send an AJAX request. The server-side code would look rather similar to this.

Documentation and Related Reading

adding directory to sys.path /PYTHONPATH

As to me, i need to caffe to my python path. I can add it's path to the file /home/xy/.bashrc by add

export PYTHONPATH=/home/xy/caffe-master/python:$PYTHONPATH.

to my /home/xy/.bashrc file.

But when I use pycharm, the path is still not in.

So I can add path to PYTHONPATH variable, by run -> edit Configuration.

enter image description here

jquery - How to determine if a div changes its height or any css attribute?

Please don't use techniques described in other answers here. They are either not working with css3 animations size changes, floating layout changes or changes that don't come from jQuery land. You can use a resize-detector, a event-based approach, that doesn't waste your CPU time.

https://github.com/marcj/css-element-queries

It contains a ResizeSensor class you can use for that purpose.

new ResizeSensor(jQuery('#mainContent'), function(){ 
    console.log('main content dimension changed');
});

Disclaimer: I wrote this library

Java converting Image to BufferedImage

From a Java Game Engine:

/**
 * Converts a given Image into a BufferedImage
 *
 * @param img The Image to be converted
 * @return The converted BufferedImage
 */
public static BufferedImage toBufferedImage(Image img)
{
    if (img instanceof BufferedImage)
    {
        return (BufferedImage) img;
    }

    // Create a buffered image with transparency
    BufferedImage bimage = new BufferedImage(img.getWidth(null), img.getHeight(null), BufferedImage.TYPE_INT_ARGB);

    // Draw the image on to the buffered image
    Graphics2D bGr = bimage.createGraphics();
    bGr.drawImage(img, 0, 0, null);
    bGr.dispose();

    // Return the buffered image
    return bimage;
}

How does the SQL injection from the "Bobby Tables" XKCD comic work?

Let's say the name was used in a variable, $Name.

You then run this query:

INSERT INTO Students VALUES ( '$Name' )

The code is mistakenly placing anything the user supplied as the variable.

You wanted the SQL to be:

INSERT INTO Students VALUES ( 'Robert Tables` )

But a clever user can supply whatever they want:

INSERT INTO Students VALUES ( 'Robert'); DROP TABLE Students; --' )

What you get is:

INSERT INTO Students VALUES ( 'Robert' );  DROP TABLE STUDENTS; --' )

The -- only comments the remainder of the line.

jQuery SVG vs. Raphael

I will throw my vote behind Raphael - the cross-browser support, clean API and consistent updates (so far) make it a joy to use. It plays very nicely with jQuery too. Processing is cool, but more useful as a demo for bleeding-edge stuff at the moment.

Laravel Eloquent: How to get only certain columns from joined tables

I know that this is an old question, but if you are building an API, as the author of the question does, use output transformers to perform such tasks.

Transofrmer is a layer between your actual database query result and a controller. It allows to easily control and modify what is going to be output to a user or an API consumer.

I recommend Fractal as a solid foundation of your output transformation layer. You can read the documentation here.

Activity <App Name> has leaked ServiceConnection <ServiceConnection Name>@438030a8 that was originally bound here

You should only need to unbind the service in onDestroy(). Then, The warning will go.

See here.

As the Activity doc tries to explain, there are three main bind/unbind groupings you will use: onCreate() and onDestroy(), onStart() and onStop(), and onResume() and onPause().

sqlalchemy: how to join several tables by one query?

Try this

q = Session.query(
         User, Document, DocumentPermissions,
    ).filter(
         User.email == Document.author,
    ).filter(
         Document.name == DocumentPermissions.document,
    ).filter(
        User.email == 'someemail',
    ).all()

Are there benefits of passing by pointer over passing by reference in C++?

Most of the answers here fail to address the inherent ambiguity in having a raw pointer in a function signature, in terms of expressing intent. The problems are the following:

  • The caller does not know whether the pointer points to a single objects, or to the start of an "array" of objects.

  • The caller does not know whether the pointer "owns" the memory it points to. IE, whether or not the function should free up the memory. (foo(new int) - Is this a memory leak?).

  • The caller does not know whether or not nullptr can be safely passed into the function.

All of these problems are solved by references:

  • References always refer to a single object.

  • References never own the memory they refer to, they are merely a view into memory.

  • References can't be null.

This makes references a much better candidate for general use. However, references aren't perfect - there are a couple of major problems to consider.

  • No explicit indirection. This is not a problem with a raw pointer, as we have to use the & operator to show that we are indeed passing a pointer. For example, int a = 5; foo(a); It is not clear at all here that a is being passed by reference and could be modified.
  • Nullability. This weakness of pointers can also be a strength, when we actually want our references to be nullable. Seeing as std::optional<T&> isn't valid (for good reasons), pointers give us that nullability you want.

So it seems that when we want a nullable reference with explicit indirection, we should reach for a T* right? Wrong!

Abstractions

In our desperation for nullability, we may reach for T*, and simply ignore all of the shortcomings and semantic ambiguity listed earlier. Instead, we should reach for what C++ does best: an abstraction. If we simply write a class that wraps around a pointer, we gain the expressiveness, as well as the nullability and explicit indirection.

template <typename T>
struct optional_ref {
  optional_ref() : ptr(nullptr) {}
  optional_ref(T* t) : ptr(t) {}
  optional_ref(std::nullptr_t) : ptr(nullptr) {}

  T& get() const {
    return *ptr;
  }

  explicit operator bool() const {
    return bool(ptr);
  }

private:
  T* ptr;
};

This is the most simple interface I could come up with, but it does the job effectively. It allows for initializing the reference, checking whether a value exists and accessing the value. We can use it like so:

void foo(optional_ref<int> x) {
  if (x) {
    auto y = x.get();
    // use y here
  }
}

int x = 5;
foo(&x); // explicit indirection here
foo(nullptr); // nullability

We have acheived our goals! Let's now see the benefits, in comparison to the raw pointer.

  • The interface shows clearly that the reference should only refer to one object.
  • Clearly it does not own the memory it refers to, as it has no user defined destructor and no method to delete the memory.
  • The caller knows nullptr can be passed in, since the function author explicitly is asking for an optional_ref

We could make the interface more complex from here, such as adding equality operators, a monadic get_or and map interface, a method that gets the value or throws an exception, constexpr support. That can be done by you.

In conclusion, instead of using raw pointers, reason about what those pointers actually mean in your code, and either leverage a standard library abstraction or write your own. This will improve your code significantly.

What evaluates to True/False in R?

This is documented on ?logical. The pertinent section of which is:

Details:

     ‘TRUE’ and ‘FALSE’ are reserved words denoting logical constants
     in the R language, whereas ‘T’ and ‘F’ are global variables whose
     initial values set to these.  All four are ‘logical(1)’ vectors.

     Logical vectors are coerced to integer vectors in contexts where a
     numerical value is required, with ‘TRUE’ being mapped to ‘1L’,
     ‘FALSE’ to ‘0L’ and ‘NA’ to ‘NA_integer_’.

The second paragraph there explains the behaviour you are seeing, namely 5 == 1L and 5 == 0L respectively, which should both return FALSE, where as 1 == 1L and 0 == 0L should be TRUE for 1 == TRUE and 0 == FALSE respectively. I believe these are not testing what you want them to test; the comparison is on the basis of the numerical representation of TRUE and FALSE in R, i.e. what numeric values they take when coerced to numeric.

However, only TRUE is guaranteed to the be TRUE:

> isTRUE(TRUE)
[1] TRUE
> isTRUE(1)
[1] FALSE
> isTRUE(T)
[1] TRUE
> T <- 2
> isTRUE(T)
[1] FALSE

isTRUE is a wrapper for identical(x, TRUE), and from ?isTRUE we note:

Details:
....

     ‘isTRUE(x)’ is an abbreviation of ‘identical(TRUE, x)’, and so is
     true if and only if ‘x’ is a length-one logical vector whose only
     element is ‘TRUE’ and which has no attributes (not even names).

So by the same virtue, only FALSE is guaranteed to be exactly equal to FALSE.

> identical(F, FALSE)
[1] TRUE
> identical(0, FALSE)
[1] FALSE
> F <- "hello"
> identical(F, FALSE)
[1] FALSE

If this concerns you, always use isTRUE() or identical(x, FALSE) to check for equivalence with TRUE and FALSE respectively. == is not doing what you think it is.

How can I view the contents of an ElasticSearch index?

I can recommend Elasticvue, which is modern, free and open source. It allows accessing your ES instance via browser add-ons quite easily (supports Firefox, Chrome, Edge). But there are also further ways.

Just make sure you set cors values in elasticsearch.yml appropiate.

Length of array in function argument

This is a old question, and the OP seems to mix C++ and C in his intends/examples. In C, when you pass a array to a function, it's decayed to pointer. So, there is no way to pass the array size except by using a second argument in your function that stores the array size:

void func(int A[]) 
// should be instead: void func(int * A, const size_t elemCountInA)

They are very few cases, where you don't need this, like when you're using multidimensional arrays:

void func(int A[3][whatever here]) // That's almost as if read "int* A[3]"

Using the array notation in a function signature is still useful, for the developer, as it might be an help to tell how many elements your functions expects. For example:

void vec_add(float out[3], float in0[3], float in1[3])

is easier to understand than this one (although, nothing prevent accessing the 4th element in the function in both functions):

void vec_add(float * out, float * in0, float * in1)

If you were to use C++, then you can actually capture the array size and get what you expect:

template <size_t N>
void vec_add(float (&out)[N], float (&in0)[N], float (&in1)[N])
{
    for (size_t i = 0; i < N; i++) 
        out[i] = in0[i] + in1[i];
}

In that case, the compiler will ensure that you're not adding a 4D vector with a 2D vector (which is not possible in C without passing the dimension of each dimension as arguments of the function). There will be as many instance of the vec_add function as the number of dimensions used for your vectors.

Error: No Entity Framework provider found for the ADO.NET provider with invariant name 'System.Data.SqlClient'

Add "EntityFramework.SqlServer.dll" into your bin folder. Problem will get resolved.

What is the best place for storing uploaded images, SQL database or disk file system?

It depends on your requirements, specially volume, users and frequency of search. But, for small or medium office, the best option is to use an application like Apple Photos or Adobe Lighroom. They are specialized to store, catalog, index, and organize this kind of resource. But, for large organizations, with strong requirements of storage and high number of users, it is recommend instantiate an Content Management plataform with a Digital Asset Management, like Nuxeo or Alfresco; both offers very good resources do manage very large volumes of data with simplified methods to retrive them. And, very important: there is an free (open source) option for both platforms.

No mapping found for HTTP request with URI.... in DispatcherServlet with name

If you are using Maven , Add these to your pom.xml

<dependency>
<groupid>javax.servlet</groupid>
<artifactId>jstl</artifactId>
<version>1.2</version>
<scope>runtime</scope>

<dependency>
<groupid>taglibs</groupid>
<artifactId>standard</artifactId>
<version>1.1.2</version>
<scope>runtime</scope>

php return 500 error but no error log

You need to enable the PHP error log.

This is due to some random glitch in the web server when you have a php error, it throws a 500 internal error (i have the same issue).

If you look in the PHP error log, you should find your solution.

see here in the doc of how to enable it in the php.ini

Using any() and all() to check if a list contains one set of values or another

Generally speaking:

all and any are functions that take some iterable and return True, if

  • in the case of all(), no values in the iterable are falsy;
  • in the case of any(), at least one value is truthy.

A value x is falsy iff bool(x) == False. A value x is truthy iff bool(x) == True.

Any non-booleans in the iterable will be fine — bool(x) will coerce any x according to these rules: 0, 0.0, None, [], (), [], set(), and other empty collections will yield False, anything else True. The docstring for bool uses the terms 'true'/'false' for 'truthy'/'falsy', and True/False for the concrete boolean values.


In your specific code samples:

You misunderstood a little bit how these functions work. Hence, the following does something completely not what you thought:

if any(foobars) == big_foobar:

...because any(foobars) would first be evaluated to either True or False, and then that boolean value would be compared to big_foobar, which generally always gives you False (unless big_foobar coincidentally happened to be the same boolean value).

Note: the iterable can be a list, but it can also be a generator/generator expression (˜ lazily evaluated/generated list) or any other iterator.

What you want instead is:

if any(x == big_foobar for x in foobars):

which basically first constructs an iterable that yields a sequence of booleans—for each item in foobars, it compares the item to big_foobar and emits the resulting boolean into the resulting sequence:

tmp = (x == big_foobar for x in foobars)

then any walks over all items in tmp and returns True as soon as it finds the first truthy element. It's as if you did the following:

In [1]: foobars = ['big', 'small', 'medium', 'nice', 'ugly']                                        

In [2]: big_foobar = 'big'                                                                          

In [3]: any(['big' == big_foobar, 'small' == big_foobar, 'medium' == big_foobar, 'nice' == big_foobar, 'ugly' == big_foobar])        
Out[3]: True

Note: As DSM pointed out, any(x == y for x in xs) is equivalent to y in xs but the latter is more readable, quicker to write and runs faster.

Some examples:

In [1]: any(x > 5 for x in range(4))
Out[1]: False

In [2]: all(isinstance(x, int) for x in range(10))
Out[2]: True

In [3]: any(x == 'Erik' for x in ['Erik', 'John', 'Jane', 'Jim'])
Out[3]: True

In [4]: all([True, True, True, False, True])
Out[4]: False

See also: http://docs.python.org/2/library/functions.html#all

How to run JUnit tests with Gradle?

If you created your project with Spring Initializr, everything should be configured correctly and all you need to do is run...

./gradlew clean test --info
  • Use --info if you want to see test output.
  • Use clean if you want to re-run tests that have already passed since the last change.

Dependencies required in build.gradle for testing in Spring Boot...

dependencies {
    compile('org.springframework.boot:spring-boot-starter')
    testCompile('org.springframework.boot:spring-boot-starter-test')
}

For some reason the test runner doesn't tell you this, but it produces an HTML report in build/reports/tests/test/index.html.

How to correctly use Html.ActionLink with ASP.NET MVC 4 Areas

Just to add up my bit:
Remember, you're gonna need to have at least 2 areas in your MVC application to get the routeValues: { area="" } working; otherwise the area value will be used as a query-string parameter and you link will look like this: /?area=

If you don't have at least 2 areas, you can fix this behavior by:
1. editing the default route in RouteConfig.cs like this:

routes.MapRoute(
    name: "Default",
    url: "{controller}/{action}/{id}",
    defaults: new { area = "", controller = "Home", action = "Index", id = UrlParameter.Optional }
);

OR
2. Adding a dummy area to your MVC project.

What is the difference between int, Int16, Int32 and Int64?

They both are indeed synonymous, However i found the small difference between them,

1)You cannot use Int32 while creatingenum

enum Test : Int32
{ XXX = 1   // gives you compilation error
}

enum Test : int
{ XXX = 1   // Works fine
}

2) Int32 comes under System declaration. if you remove using.System you will get compilation error but not in case for int

Is there a regular expression to detect a valid regular expression?

You can submit the regex to preg_match which will return false if the regex is not valid. Don't forget to use the @ to suppress error messages:

@preg_match($regexToTest, '');
  • Will return 1 if the regex is //.
  • Will return 0 if the regex is okay.
  • Will return false otherwise.

Exponentiation in Python - should I prefer ** operator instead of math.pow and math.sqrt?

Even in base Python you can do the computation in generic form

result = sum(x**2 for x in some_vector) ** 0.5

x ** 2 is surely not an hack and the computation performed is the same (I checked with cpython source code). I actually find it more readable (and readability counts).

Using instead x ** 0.5 to take the square root doesn't do the exact same computations as math.sqrt as the former (probably) is computed using logarithms and the latter (probably) using the specific numeric instruction of the math processor.

I often use x ** 0.5 simply because I don't want to add math just for that. I'd expect however a specific instruction for the square root to work better (more accurately) than a multi-step operation with logarithms.

Two values from one input in python?

The easiest way that I found for myself was using split function with input Like you have two variable a,b

a,b=input("Enter two numbers").split()

That's it. there is one more method(explicit method) Eg- you want to take input in three values

value=input("Enter the line")
a,b,c=value.split()

EASY..

Renaming a branch in GitHub

You can do that without the terminal. You just need to create a branch with the new name, and remove the old after.

Create a branch

In your repository’s branch selector, just start typing a new branch name. It’ll give you the option to create a new branch:

Create a branch

It’ll branch off of your current context. For example, if you’re on the bugfix branch, it’ll create a new branch from bugfix instead of master. Looking at a commit or a tag instead? It’ll branch your code from that specific revision.

Delete a branch

You’ll also see a delete button in your repository’s Branches page:

Delete a branch

As an added bonus, it’ll also give you a link to the branch’s Pull Request, if it has one.

I just copied this content from: Create and delete branches

How can I list ALL DNS records?

For Windows:

You may find the need to check the status of your domains DNS records, or check the Name Servers to see which records the servers are pulling.

  1. Launch Windows Command Prompt by navigating to Start > Command Prompt or via Run > CMD.

  2. Type NSLOOKUP and hit Enter. The default Server is set to your local DNS, the Address will be your local IP.

  3. Set the DNS Record type you wish to lookup by typing set type=## where ## is the record type, then hit Enter. You may use ANY, A, AAAA, A+AAAA, CNAME, MX, NS, PTR, SOA, or SRV as the record type.

  4. Now enter the domain name you wish to query then hit Enter.. In this example, we will use Managed.com.

  5. NSLOOKUP will now return the record entries for the domain you entered.

  6. You can also change the Name Servers which you are querying. This is useful if you are checking the records before DNS has fully propagated. To change the Name Server type server [name server]. Replace [name server] with the Name Servers you wish to use. In this example, we will set these as NSA.managed.com.

  7. Once changed, change the query type (Step 3) if needed then enter new a new domain (Step 4.)

For Linux:

1) Check DNS Records Using Dig Command Dig stands for domain information groper is a flexible tool for interrogating DNS name servers. It performs DNS lookups and displays the answers that are returned from the name server(s) that were queried. Most DNS administrators use dig to troubleshoot DNS problems because of its flexibility, ease of use and clarity of output. Other lookup tools tend to have less functionality than dig.

2) Check DNS Records Using NSlookup Command Nslookup is a program to query Internet domain name servers. Nslookup has two modes interactive and non-interactive.

Interactive mode allows the user to query name servers for information about various hosts and domains or to print a list of hosts in a domain.

Non-interactive mode is used to print just the name and requested information for a host or domain. It’s network administration tool which will help them to check and troubleshoot DNS related issues.

3) Check DNS Records Using Host Command host is a simple utility for performing DNS lookups. It is normally used to convert names to IP addresses and vice versa. When no arguments or options are given, host prints a short summary of its command line arguments and options.

Laravel - Eloquent "Has", "With", "WhereHas" - What do they mean?

With

with() is for eager loading. That basically means, along the main model, Laravel will preload the relationship(s) you specify. This is especially helpful if you have a collection of models and you want to load a relation for all of them. Because with eager loading you run only one additional DB query instead of one for every model in the collection.

Example:

User > hasMany > Post

$users = User::with('posts')->get();
foreach($users as $user){
    $users->posts; // posts is already loaded and no additional DB query is run
}

Has

has() is to filter the selecting model based on a relationship. So it acts very similarly to a normal WHERE condition. If you just use has('relation') that means you only want to get the models that have at least one related model in this relation.

Example:

User > hasMany > Post

$users = User::has('posts')->get();
// only users that have at least one post are contained in the collection

WhereHas

whereHas() works basically the same as has() but allows you to specify additional filters for the related model to check.

Example:

User > hasMany > Post

$users = User::whereHas('posts', function($q){
    $q->where('created_at', '>=', '2015-01-01 00:00:00');
})->get();
// only users that have posts from 2015 on forward are returned

Pass command parameter to method in ViewModel in WPF?

Try this:

 public class MyVmBase : INotifyPropertyChanged
{
  private ICommand _clickCommand;
   public ICommand ClickCommand
    {
        get
        {
            return _clickCommand ?? (_clickCommand = new CommandHandler( MyAction));
        }
    }
    
       public void MyAction(object message)
    {
        if(message == null)
        {
            Notify($"Method {message} not defined");
            return;
        }
        switch (message.ToString())
        {
            case "btnAdd":
                {
                    btnAdd_Click();
                    break;
                }

            case "BtnEdit_Click":
                {
                    BtnEdit_Click();
                    break;
                }

            default:
                throw new Exception($"Method {message} not defined");
                break;
        }
    }
}

  public class CommandHandler : ICommand
{
    private Action<object> _action;
    private Func<object, bool> _canExecute;

    /// <summary>
    /// Creates instance of the command handler
    /// </summary>
    /// <param name="action">Action to be executed by the command</param>
    /// <param name="canExecute">A bolean property to containing current permissions to execute the command</param>
    public CommandHandler(Action<object> action, Func<object, bool> canExecute)
    {
        if (action == null) throw new ArgumentNullException(nameof(action));
        _action = action;
        _canExecute = canExecute ?? (x => true);
    }
    public CommandHandler(Action<object> action) : this(action, null)
    {
    }

    /// <summary>
    /// Wires CanExecuteChanged event 
    /// </summary>
    public event EventHandler CanExecuteChanged
    {
        add { CommandManager.RequerySuggested += value; }
        remove { CommandManager.RequerySuggested -= value; }
    }

    /// <summary>
    /// Forcess checking if execute is allowed
    /// </summary>
    /// <param name="parameter"></param>
    /// <returns></returns>
    public bool CanExecute(object parameter)
    {
        return _canExecute(parameter);
    }

    public void Execute(object parameter)
    {
        _action(parameter);
    }
    public void Refresh()
    {
        CommandManager.InvalidateRequerySuggested();
    }
}

And in xaml:

     <Button
    Command="{Binding ClickCommand}"
    CommandParameter="BtnEdit_Click"/>

ng-repeat: access key and value for each object in array of objects

In fact, your data is not well design. You'd better use something like :

$scope.steps = [
    {stepName: "companyName", isComplete: true},
    {stepName: "businessType", isComplete: true},
    {stepName: "physicalAddress", isComplete: true}
];

Then it is easy to do what you want :

<div ng-repeat="step in steps">
 Step {{step.stepName}} status : {{step.isComplet}}
</div>

Example: http://jsfiddle.net/rX7ba/

Spring MVC Multipart Request with JSON

As documentation says:

Raised when the part of a "multipart/form-data" request identified by its name cannot be found.

This may be because the request is not a multipart/form-data either because the part is not present in the request, or because the web application is not configured correctly for processing multipart requests -- e.g. no MultipartResolver.

Is an HTTPS query string secure?

Yes. The entire text of an HTTPS session is secured by SSL. That includes the query and the headers. In that respect, a POST and a GET would be exactly the same.

As to the security of your method, there's no real way to say without proper inspection.

docker : invalid reference format

I had a similar problem. Issue I was having was $(pwd) has a space in there which was throwing docker run off.

Change the directory name to not have spaces in there, and it should work if this is the problem

How to send characters in PuTTY serial communication only when pressing enter?

The settings you need are "Local echo" and "Line editing" under the "Terminal" category on the left.

To get the characters to display on the screen as you enter them, set "Local echo" to "Force on".

To get the terminal to not send the command until you press Enter, set "Local line editing" to "Force on".

PuTTY Line discipline options

Explanation:

From the PuTTY User Manual (Found by clicking on the "Help" button in PuTTY):

4.3.8 ‘Local echo’

With local echo disabled, characters you type into the PuTTY window are not echoed in the window by PuTTY. They are simply sent to the server. (The server might choose to echo them back to you; this can't be controlled from the PuTTY control panel.)

Some types of session need local echo, and many do not. In its default mode, PuTTY will automatically attempt to deduce whether or not local echo is appropriate for the session you are working in. If you find it has made the wrong decision, you can use this configuration option to override its choice: you can force local echo to be turned on, or force it to be turned off, instead of relying on the automatic detection.

4.3.9 ‘Local line editing’ Normally, every character you type into the PuTTY window is sent immediately to the server the moment you type it.

If you enable local line editing, this changes. PuTTY will let you edit a whole line at a time locally, and the line will only be sent to the server when you press Return. If you make a mistake, you can use the Backspace key to correct it before you press Return, and the server will never see the mistake.

Since it is hard to edit a line locally without being able to see it, local line editing is mostly used in conjunction with local echo (section 4.3.8). This makes it ideal for use in raw mode or when connecting to MUDs or talkers. (Although some more advanced MUDs do occasionally turn local line editing on and turn local echo off, in order to accept a password from the user.)

Some types of session need local line editing, and many do not. In its default mode, PuTTY will automatically attempt to deduce whether or not local line editing is appropriate for the session you are working in. If you find it has made the wrong decision, you can use this configuration option to override its choice: you can force local line editing to be turned on, or force it to be turned off, instead of relying on the automatic detection.

Putty sometimes makes wrong choices when "Auto" is enabled for these options because it tries to detect the connection configuration. Applied to serial line, this is a bit trickier to do.

What does 'URI has an authority component' mean?

After trying a skeleton project called "jsf-blank", which did not demonstrate this problem with xhtml files; I concluded that there was an unknown problem in my project. My solution may not have been too elegant, but it saved time. I backed up the code and other files I'd already developed, deleted the project, and started over - recreated the project. So far, I've added back most of the files and it looks pretty good.

What's the best way to check if a file exists in C?

You can use realpath() function.

resolved_file = realpath(file_path, NULL);
if (!resolved_keyfile) {
   /*File dosn't exists*/
   perror(keyfile);
   return -1;
}

How do I change a TCP socket to be non-blocking?

It is sometimes convenient to employ the "send/recv" family of system calls. If the flags parameter contains the MSG_DONTWAIT flag, each call will behave similar to a socket having the O_NONBLOCK flag set.

ssize_t send(int sockfd, const void *buf, size_t len, int flags);

ssize_t recv(int sockfd, void *buf, size_t len, int flags);

How to validate GUID is a GUID

if(MyGuid!=Guild.Empty)

{

//Valid Guild

}

else {

// Invalid Guild

}

Get loop counter/index using for…of syntax in JavaScript

That's my version of a composite iterator that yields an index and any passed generator function's value with an example of (slow) prime search:

_x000D_
_x000D_
const eachWithIndex = (iterable) => {_x000D_
  return {_x000D_
    *[Symbol.iterator]() {_x000D_
      let i = 0_x000D_
      for(let val of iteratable) {_x000D_
        i++_x000D_
          yield [i, val]_x000D_
      }_x000D_
    }_x000D_
  }_x000D_
_x000D_
}_x000D_
_x000D_
const isPrime = (n) => {_x000D_
  for (i = 2; i < Math.floor(Math.sqrt(n) + 1); i++) {_x000D_
    if (n % i == 0) {_x000D_
      return false_x000D_
    }_x000D_
  }_x000D_
  return true_x000D_
}_x000D_
_x000D_
let primes = {_x000D_
  *[Symbol.iterator]() {_x000D_
    let candidate = 2_x000D_
    while (true) {_x000D_
      if (isPrime(candidate)) yield candidate_x000D_
        candidate++_x000D_
    }_x000D_
  }_x000D_
}_x000D_
_x000D_
for (const [i, prime] of eachWithIndex(primes)) {_x000D_
  console.log(i, prime)_x000D_
  if (i === 100) break_x000D_
}
_x000D_
_x000D_
_x000D_

How to generate .env file for laravel?

If you have trouble viewing the .env file or it is not showing up in the project just do this: ls -a.
This allows to see the hidden files in Linux. You can also open the folder with Visual Studio Code and you will see the files and be able to modify them.

How do I set up Visual Studio Code to compile C++ code?

To Build/run C++ projects in VS code , you manually need to configure tasks.json file which is in .vscode folder in workspace folder . To open tasks.json , press ctrl + shift + P , and type Configure tasks , and press enter, it will take you to tasks.json

Here i am providing my tasks.json file with some comments to make the file more understandable , It can be used as a reference for configuring tasks.json , i hope it will be useful

tasks.json

{
    "version": "2.0.0",

    "tasks": [

        {
            "label": "build & run",     //It's name of the task , you can have several tasks 
            "type": "shell",    //type can be either 'shell' or 'process' , more details will be given below
            "command": "g++",   
            "args": [
                "-g",   //gnu debugging flag , only necessary if you want to perform debugging on file  
                "${file}",  //${file} gives full path of the file
                "-o",   
                "${workspaceFolder}\\build\\${fileBasenameNoExtension}",    //output file name
                "&&",   //to join building and running of the file
                "${workspaceFolder}\\build\\${fileBasenameNoExtension}"
            ],
            "group": {
                "kind": "build",    //defines to which group the task belongs
                "isDefault": true
            },
            "presentation": {   //Explained in detail below
                "echo": false,
                "reveal": "always",
                "focus": true,
                "panel": "shared",
                "clear": false,
                "showReuseMessage": false
            },
            "problemMatcher": "$gcc"
        },

    ]
}

Now , stating directly from the VS code tasks documentation

description of type property :

  • type: The task's type. For a custom task, this can either be shell or process. If shell is specified, the command is interpreted as a shell command (for example: bash, cmd, or PowerShell). If process is specified, the command is interpreted as a process to execute.

The behavior of the terminal can be controlled using the presentation property in tasks.json . It offers the following properties:

  • reveal: Controls whether the Integrated Terminal panel is brought to front. Valid values are:

    • always - The panel is always brought to front. This is the default
    • never - The user must explicitly bring the terminal panel to the front using the View > Terminal command (Ctrl+`).
    • silent - The terminal panel is brought to front only if the output is not scanned for errors and warnings.
  • focus: Controls whether the terminal is taking input focus or not. Default is false.

  • echo: Controls whether the executed command is echoed in the terminal. Default is true.
  • showReuseMessage: Controls whether to show the "Terminal will be reused by tasks, press any key to close it" message.
  • panel: Controls whether the terminal instance is shared between task runs. Possible values are:
    • shared: The terminal is shared and the output of other task runs are added to the same terminal.
    • dedicated: The terminal is dedicated to a specific task. If that task is executed again, the terminal is reused. However, the output of a different task is presented in a different terminal.
    • new: Every execution of that task is using a new clean terminal.
  • clear: Controls whether the terminal is cleared before this task is run. Default is false.

How can I copy network files using Robocopy?

You should be able to use Windows "UNC" paths with robocopy. For example:

robocopy \\myServer\myFolder\myFile.txt \\myOtherServer\myOtherFolder

Robocopy has the ability to recover from certain types of network hiccups automatically.

What does the CSS rule "clear: both" do?

CSS float and clear

Sample Fiddle

Just try to remove clear:both property from the div with class sample and see how it follows floating divs.

How do I change TextView Value inside Java Code?

First we need to find a Button:

Button mButton = (Button) findViewById(R.id.my_button);

After that, you must implement View.OnClickListener and there you should find the TextView and execute the method setText:

mButton.setOnClickListener(new View.OnClickListener {
    public void onClick(View v) {
        final TextView mTextView = (TextView) findViewById(R.id.my_text_view);
        mTextView.setText("Some Text");
    }
});

Non-recursive depth first search algorithm

If you have pointers to parent nodes, you can do it without additional memory.

def dfs(root):
    node = root
    while True:
        visit(node)
        if node.first_child:
            node = node.first_child      # walk down
        else:
            while not node.next_sibling:
                if node is root:
                    return
                node = node.parent       # walk up ...
            node = node.next_sibling     # ... and right

Note that if the child nodes are stored as an array rather than through sibling pointers, the next sibling can be found as:

def next_sibling(node):
    try:
        i =    node.parent.child_nodes.index(node)
        return node.parent.child_nodes[i+1]
    except (IndexError, AttributeError):
        return None

How do I copy directories recursively with gulp?

If you want to copy the entire contents of a folder recursively into another folder, you can execute the following windows command from gulp:

xcopy /path/to/srcfolder /path/to/destfolder /s /e /y

The /y option at the end is to suppress the overwrite confirmation message.

In Linux, you can execute the following command from gulp:

cp -R /path/to/srcfolder /path/to/destfolder

you can use gulp-exec or gulp-run plugin to execute system commands from gulp.

Related Links:

  1. xcopy usage

  2. gulp-exec and gulp-run

How to remove focus from input field in jQuery?

Use .blur().

The blur event is sent to an element when it loses focus. Originally, this event was only applicable to form elements, such as <input>. In recent browsers, the domain of the event has been extended to include all element types. An element can lose focus via keyboard commands, such as the Tab key, or by mouse clicks elsewhere on the page.

$("#myInputID").blur(); 

Python time measure function

Decorator method using decorator Python library:

import decorator

@decorator
def timing(func, *args, **kwargs):
    '''Function timing wrapper
        Example of using:
        ``@timing()``
    '''

    fn = '%s.%s' % (func.__module__, func.__name__)

    timer = Timer()
    with timer:
        ret = func(*args, **kwargs)

    log.info(u'%s - %0.3f sec' % (fn, timer.duration_in_seconds()))
    return ret

See post on my Blog:

post on mobilepro.pl Blog

my post on Google Plus

Error : Program type already present: android.support.design.widget.CoordinatorLayout$Behavior

As android latest update doesn't support 'compile' keyword use 'implementation' in place inside your module build.gradle file.

And check thoroughly in build.gradle for dependancy with + sign like this.

implementation 'com.android.support:support-v4:28.+'

If there are any dependencies like this, just update them with a specific version. After that:

  1. Sync gradle.
  2. Clean your project.
  3. Rebuild the project.

Push to GitHub without a password using ssh-key

You have to use the SSH version, not HTTPS. When you clone from a repository, copy the link with the SSH version, because SSH is easy to use and solves all problems with access. You can set the access for every SSH you input into your account (like push, pull, clone, etc...)

Here is a link, which says why we need SSH and how to use it: step by step

Git Generate SSH Keys

How disable / remove android activity label and label bar?

public void onCreate(Bundle savedInstanceState) {  
        super.onCreate(savedInstanceState);  

        //set up notitle 
        requestWindowFeature(Window.FEATURE_NO_TITLE);  
        //set up full screen
        getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,   
                WindowManager.LayoutParams.FLAG_FULLSCREEN);  

        setContentView(R.layout.main);  
} 

"replace" function examples

Here's an example where I found the replace( ) function helpful for giving me insight. The problem required a long integer vector be changed into a character vector and with its integers replaced by given character values.

## figuring out replace( )
(test <- c(rep(1,3),rep(2,2),rep(3,1)))

which looks like

[1] 1 1 1 2 2 3

and I want to replace every 1 with an A and 2 with a B and 3 with a C

letts <- c("A","B","C")

so in my own secret little "dirty-verse" I used a loop

for(i in 1:3)
{test <- replace(test,test==i,letts[i])}

which did what I wanted

test
[1] "A" "A" "A" "B" "B" "C"

In the first sentence I purposefully left out that the real objective was to make the big vector of integers a factor vector and assign the integer values (levels) some names (labels).

So another way of doing the replace( ) application here would be

(test <- factor(test,labels=letts))
[1] A A A B B C
Levels: A B C

How to set Grid row and column positions programmatically

Here is an example which might help someone:

Grid test = new Grid();
test.ColumnDefinitions.Add(new ColumnDefinition());
test.ColumnDefinitions.Add(new ColumnDefinition());
test.RowDefinitions.Add(new RowDefinition());
test.RowDefinitions.Add(new RowDefinition());
test.RowDefinitions.Add(new RowDefinition());

Label t1 = new Label();
t1.Content = "Test1";
Label t2 = new Label();
t2.Content = "Test2";
Label t3 = new Label();
t3.Content = "Test3";
Label t4 = new Label();
t4.Content = "Test4";
Label t5 = new Label();
t5.Content = "Test5";
Label t6 = new Label();
t6.Content = "Test6";

Grid.SetColumn(t1, 0);
Grid.SetRow(t1, 0);
test.Children.Add(t1);

Grid.SetColumn(t2, 1);
Grid.SetRow(t2, 0);
test.Children.Add(t2);

Grid.SetColumn(t3, 0);
Grid.SetRow(t3, 1);
test.Children.Add(t3);

Grid.SetColumn(t4, 1);
Grid.SetRow(t4, 1);
test.Children.Add(t4);

Grid.SetColumn(t5, 0);
Grid.SetRow(t5, 2);
test.Children.Add(t5);

Grid.SetColumn(t6, 1);
Grid.SetRow(t6, 2);
test.Children.Add(t6);

Box shadow in IE7 and IE8

use this for fixing issue with shadow box

filter: progid:DXImageTransform.Microsoft.dropShadow (OffX='2', OffY='2', Color='#F13434', Positive='true');

Difference between Node object and Element object?

Node is used to represent tags in general. Divided to 3 types:

Attribute Note: is node which inside its has attributes. Exp: <p id=”123”></p>

Text Node: is node which between the opening and closing its have contian text content. Exp: <p>Hello</p>

Element Node : is node which inside its has other tags. Exp: <p><b></b></p>

Each node may be types simultaneously, not necessarily only of a single type.

Element is simply a element node.

Delayed rendering of React components

We can solve this using Hooks:

First we'll need a timeout hook for the delay.

This one is inspired by Dan Abramov's useInterval hook (see Dan's blog post for an in depth explanation), the differences being:

  1. we use we setTimeout not setInterval
  2. we return a reset function allowing us to restart the timer at any time

_x000D_
_x000D_
import { useEffect, useRef, useCallback } from 'react';_x000D_
_x000D_
const useTimeout = (callback, delay) => {_x000D_
  // save id in a ref_x000D_
  const timeoutId = useRef('');_x000D_
_x000D_
  // save callback as a ref so we can update the timeout callback without resetting the clock_x000D_
  const savedCallback = useRef();_x000D_
  useEffect(_x000D_
    () => {_x000D_
      savedCallback.current = callback;_x000D_
    },_x000D_
    [callback],_x000D_
  );_x000D_
_x000D_
  // clear the timeout and start a new one, updating the timeoutId ref_x000D_
  const reset = useCallback(_x000D_
    () => {_x000D_
      clearTimeout(timeoutId.current);_x000D_
_x000D_
      const id = setTimeout(savedCallback.current, delay);_x000D_
      timeoutId.current = id;_x000D_
    },_x000D_
    [delay],_x000D_
  );_x000D_
_x000D_
  useEffect(_x000D_
    () => {_x000D_
      if (delay !== null) {_x000D_
        reset();_x000D_
_x000D_
        return () => clearTimeout(timeoutId.current);_x000D_
      }_x000D_
    },_x000D_
    [delay, reset],_x000D_
  );_x000D_
_x000D_
  return { reset };_x000D_
};
_x000D_
_x000D_
_x000D_

and now we need a hook which will capture previous children and use our useTimeout hook to swap in the new children after a delay

_x000D_
_x000D_
import { useState, useEffect } from 'react';_x000D_
_x000D_
const useDelayNextChildren = (children, delay) => {_x000D_
  const [finalChildren, setFinalChildren] = useState(children);_x000D_
_x000D_
  const { reset } = useTimeout(() => {_x000D_
    setFinalChildren(children);_x000D_
  }, delay);_x000D_
_x000D_
  useEffect(_x000D_
    () => {_x000D_
      reset();_x000D_
    },_x000D_
    [reset, children],_x000D_
  );_x000D_
_x000D_
  return finalChildren || children || null;_x000D_
};
_x000D_
_x000D_
_x000D_

Note that the useTimeout callback will always have the latest children, so even if we attempt to render multiple different new children within the delay time, we'll always get the latest children once the timeout finally completes.

Now in your case, we want to also delay the initial render, so we make this change:

_x000D_
_x000D_
const useDelayNextChildren = (children, delay) => {_x000D_
  const [finalChildren, setFinalChildren] = useState(null); // initial state set to null_x000D_
_x000D_
  // ... stays the same_x000D_
_x000D_
  return finalChildren || null;  // remove children from return_x000D_
};
_x000D_
_x000D_
_x000D_

and using the above hook, your entire child component becomes

_x000D_
_x000D_
import React, { memo } from 'react';_x000D_
import { useDelayNextChildren } from 'hooks';_x000D_
_x000D_
const Child = ({ delay }) => useDelayNextChildren(_x000D_
  <div>_x000D_
    ... Child JSX goes here_x000D_
    ... etc_x000D_
  </div>_x000D_
  , delay_x000D_
);_x000D_
_x000D_
export default memo(Child);
_x000D_
_x000D_
_x000D_

or if you prefer: ( dont say i havent given you enough code ;) )

_x000D_
_x000D_
const Child = ({ delay }) => {_x000D_
  const render = <div>... Child JSX goes here ... etc</div>;_x000D_
_x000D_
  return useDelayNextChildren(render, delay);_x000D_
};
_x000D_
_x000D_
_x000D_

which will work exactly the same in the Parent render function as in the accepted answer

...

except the delay will be the same on every subsequent render too,

AND we used hooks, so that stateful logic is reusable across any component

...

...

use hooks. :D

How to load image to WPF in runtime?

Make sure that your sas.png is marked as Build Action: Content and Copy To Output Directory: Copy Always in its Visual Studio Properties...

I think the C# source code goes like this...

Image image = new Image();
image.Source = (new ImageSourceConverter()).ConvertFromString("pack://application:,,,/Bilder/sas.png") as ImageSource;

and XAML should be

<Image Height="200" HorizontalAlignment="Left" Margin="12,12,0,0" 
       Name="image1" Stretch="Fill" VerticalAlignment="Top" 
       Source="../Bilder/sas.png"
       Width="350" />  

EDIT

Dynamically I think XAML would provide best way to load Images ...

<Image Source="{Binding Converter={StaticResource MyImageSourceConverter}}"
       x:Name="MyImage"/>

where image.DataContext is string path.

MyImage.DataContext = "pack://application:,,,/Bilder/sas.png";

public class MyImageSourceConverter : IValueConverter
{
    public object Convert(object value_, Type targetType_, 
    object parameter_, System.Globalization.CultureInfo culture_)
    {
        return (new ImageSourceConverter()).ConvertFromString (value.ToString());
    }

    public object ConvertBack(object value, Type targetType, 
    object parameter, CultureInfo culture)
    {
          throw new NotImplementedException();
    }
}

Now as you set a different data context, Image would be automatically loaded at runtime.

JavaScript: How to find out if the user browser is Chrome?

To check if browser is Google Chrome, try this:

// please note, 
// that IE11 now returns undefined again for window.chrome
// and new Opera 30 outputs true for window.chrome
// but needs to check if window.opr is not undefined
// and new IE Edge outputs to true now for window.chrome
// and if not iOS Chrome check
// so use the below updated condition
var isChromium = window.chrome;
var winNav = window.navigator;
var vendorName = winNav.vendor;
var isOpera = typeof window.opr !== "undefined";
var isIEedge = winNav.userAgent.indexOf("Edge") > -1;
var isIOSChrome = winNav.userAgent.match("CriOS");

if (isIOSChrome) {
   // is Google Chrome on IOS
} else if(
  isChromium !== null &&
  typeof isChromium !== "undefined" &&
  vendorName === "Google Inc." &&
  isOpera === false &&
  isIEedge === false
) {
   // is Google Chrome
} else { 
   // not Google Chrome 
}

Example of use: http://codepen.io/jonathan/pen/WpQELR

The reason this works is because if you use the Google Chrome inspector and go to the console tab. Type 'window' and press enter. Then you be able to view the DOM properties for the 'window object'. When you collapse the object you can view all the properties, including the 'chrome' property.

You can't use strictly equals true anymore to check in IE for window.chrome. IE used to return undefined, now it returns true. But guess what, IE11 now returns undefined again. IE11 also returns a empty string "" for window.navigator.vendor.

I hope this helps!

UPDATE:

Thank you to Halcyon991 for pointing out below, that the new Opera 18+ also outputs to true for window.chrome. Looks like Opera 18 is based on Chromium 31. So I added a check to make sure the window.navigator.vendor is: "Google Inc" and not is "Opera Software ASA". Also thanks to Ring and Adrien Be for the heads up about Chrome 33 not returning true anymore... window.chrome now checks if not null. But play close attention to IE11, I added the check back for undefined since IE11 now outputs undefined, like it did when first released.. then after some update builds it outputted to true .. now recent update build is outputting undefined again. Microsoft can't make up it's mind!

UPDATE 7/24/2015 - addition for Opera check

Opera 30 was just released. It no longer outputs window.opera. And also window.chrome outputs to true in the new Opera 30. So you must check if OPR is in the userAgent. I updated my condition above to account for this new change in Opera 30, since it uses same render engine as Google Chrome.

UPDATE 10/13/2015 - addition for IE check

Added check for IE Edge due to it outputting true for window.chrome .. even though IE11 outputs undefined for window.chrome. Thanks to artfulhacker for letting us know about this!

UPDATE 2/5/2016 - addition for iOS Chrome check

Added check for iOS Chrome check CriOS due to it outputting true for Chrome on iOS. Thanks to xinthose for letting us know about this!

UPDATE 4/18/2018 - change for Opera check

Edited check for Opera, checking window.opr is not undefined since now Chrome 66 has OPR in window.navigator.vendor. Thanks to Frosty Z and Daniel Wallman for reporting this!

django.core.exceptions.ImproperlyConfigured: Error loading MySQLdb module: No module named MySQLdb

Faced similar issue. I tried installing mysql-python using pip, but it failed due to gcc dependency errors.

The solution that worked for me

conda install mysql-python

Please note that I already had anaconda installed, which didn't had gcc dependency.

How can I capture the right-click event in JavaScript?

Use the oncontextmenu event.

Here's an example:

<div oncontextmenu="javascript:alert('success!');return false;">
    Lorem Ipsum
</div>

And using event listeners (credit to rampion from a comment in 2011):

el.addEventListener('contextmenu', function(ev) {
    ev.preventDefault();
    alert('success!');
    return false;
}, false);

Don't forget to return false, otherwise the standard context menu will still pop up.

If you are going to use a function you've written rather than javascript:alert("Success!"), remember to return false in BOTH the function AND the oncontextmenu attribute.

Check that Field Exists with MongoDB

Suppose we have a collection like below:

{ 
  "_id":"1234"
  "open":"Yes"
  "things":{
             "paper":1234
             "bottle":"Available"
             "bottle_count":40
            } 
}

We want to know if the bottle field is present or not?

Ans:

db.products.find({"things.bottle":{"$exists":true}})

How to export collection to CSV in MongoDB?

Solution for MongoDB Atlas users!

Add the --fields parameter as comma separated field names enclosed in double inverted quotes:

--fields "<FIELD 1>,<FIELD 2>..."

This is complete example:

mongoexport --host Cluster0-shard-0/shard1URL.mongodb.net:27017,shard2URL.mongodb.net:27017,shard3URL.mongodb.net:27017 --ssl --username <USERNAME> --password <PASSWORD> --authenticationDatabase admin --db <DB NAME> --collection <COLLECTION NAME> --type <OUTPUT FILE TYPE> --out <OUTPUT FILE NAME> --fields "<FIELD 1>,<FIELD 2>..."

wait process until all subprocess finish?

A Popen object has a .wait() method exactly defined for this: to wait for the completion of a given subprocess (and, besides, for retuning its exit status).

If you use this method, you'll prevent that the process zombies are lying around for too long.

(Alternatively, you can use subprocess.call() or subprocess.check_call() for calling and waiting. If you don't need IO with the process, that might be enough. But probably this is not an option, because your if the two subprocesses seem to be supposed to run in parallel, which they won't with (check_)call().)

If you have several subprocesses to wait for, you can do

exit_codes = [p.wait() for p in p1, p2]

which returns as soon as all subprocesses have finished. You then have a list of return codes which you maybe can evaluate.

How to set the context path of a web application in Tomcat 7.0

For me both answers worked.

  1. Adding a file called ROOT.xml in /conf/Catalina/localhost/
<Context
    docBase="/tmp/wars/hpong"
  path=""
  reloadable="true"
/>
  1. Adding entry in server.xml
<Service name="Catalina2">
    <Connector port="8070" protocol="HTTP/1.1"
               connectionTimeout="20000"
               redirectPort="8743" />
    <Engine name="Catalina2" defaultHost="localhost">
        <Host name="localhost"
            unpackWARs="true" autoDeploy="true">
            <Context path="" docBase="/tmp/wars/hpong"  reloadable="true">
                <WatchedResource>WEB-INF/web.xml</WatchedResource>
            </Context>
      </Host>
    </Engine>
</Service>

Note: when you declare docBase under context then ignore appBase at Host.

  1. However I have preferred converting my war name as ROOT.war and place it under webapps. So now unmatched url requests from other wars(contextpaths) will land into this war. This is better way to handle ROOT ("/**") context path.

The second option is (double) loading the wars from Webapps folder as well. Also it only needs uncompressed war folder which is a headache.

Connect to Active Directory via LDAP

If your email address is '[email protected]', try changing the createDirectoryEntry() as below.

XYZ is an optional parameter if it exists in mydomain directory

static DirectoryEntry createDirectoryEntry()
{
    // create and return new LDAP connection with desired settings
    DirectoryEntry ldapConnection = new DirectoryEntry("myname.mydomain.com");
    ldapConnection.Path = "LDAP://OU=Users, OU=XYZ,DC=mydomain,DC=com";
    ldapConnection.AuthenticationType = AuthenticationTypes.Secure;
    return ldapConnection;
}

This will basically check for com -> mydomain -> XYZ -> Users -> abcd

The main function looks as below:

try
{
    username = "Firstname LastName"
    DirectoryEntry myLdapConnection = createDirectoryEntry();
    DirectorySearcher search = new DirectorySearcher(myLdapConnection);
    search.Filter = "(cn=" + username + ")";
    ....    

how to write javascript code inside php

Just echo the javascript out inside the if function

 <form name="testForm" id="testForm"  method="POST"  >
     <input type="submit" name="btn" value="submit" autofocus  onclick="return true;"/>
 </form>
 <?php
    if(isset($_POST['btn'])){
        echo "
            <script type=\"text/javascript\">
            var e = document.getElementById('testForm'); e.action='test.php'; e.submit();
            </script>
        ";
     }
  ?>

How to install python modules without root access?

You can run easy_install to install python packages in your home directory even without root access. There's a standard way to do this using site.USER_BASE which defaults to something like $HOME/.local or $HOME/Library/Python/2.7/bin and is included by default on the PYTHONPATH

To do this, create a .pydistutils.cfg in your home directory:

cat > $HOME/.pydistutils.cfg <<EOF
[install]
user=1
EOF

Now you can run easy_install without root privileges:

easy_install boto

Alternatively, this also lets you run pip without root access:

pip install boto

This works for me.

Source from Wesley Tanaka's blog : http://wtanaka.com/node/8095

Convert NULL to empty string - Conversion failed when converting from a character string to uniqueidentifier

You need to CAST the ParentId as an nvarchar, so that the output is always the same data type.

SELECT Id   'PatientId',
       ISNULL(CAST(ParentId as nvarchar(100)),'')  'ParentId'
FROM Patients

How to reload a page after the OK click on the Alert Page

I may be wrong here but I had the same problem, after spending more time than I'm proud of I realised I had set chrome to block all pop ups and hence kept reloading without showing me the alert box. So close your window and open the page again.

If that doesn't work then you problem might be something deeper because all the solutions already given should work.

How do I make a placeholder for a 'select' box?

I just stumbled across this question, and here's what works in Firefox and Chrome (at least):

_x000D_
_x000D_
<style>_x000D_
select:invalid { color: gray; }_x000D_
</style>_x000D_
<form>_x000D_
<select required>_x000D_
    <option value="" disabled selected hidden>Please Choose...</option>_x000D_
    <option value="0">Open when powered (most valves do this)</option>_x000D_
    <option value="1">Closed when powered, auto-opens when power is cut</option>_x000D_
</select>_x000D_
</form>
_x000D_
_x000D_
_x000D_

The Disabled option stops the <option> being selected with both mouse and keyboard, whereas just using 'display:none' allows the user to still select via the keyboard arrows. The 'display:none' style just makes the list box look 'nice'.

Note: Using an empty value attribute on the "placeholder" option allows validation (required attribute) to work around having the "placeholder", so if the option isn't changed, but is required, the browser should prompt the user to choose an option from the list.

Update (July 2015):

This method is confirmed working in the following browsers:

  • Google Chrome - v.43.0.2357.132
  • Mozilla Firefox - v.39.0
  • Safari - v.8.0.7 (the placeholder is visible in dropdown, but it is not selectable)
  • Microsoft Internet Explorer - v.11 (Placeholder is visible in dropdown but is not selectable)
  • Project Spartan - v.15.10130 (the placeholder is visible in dropdown, but it is not selectable)

Update (October 2015):

I removed the style="display: none" in favour of HTML5 attribute hidden which has wide support. The hidden element has similar traits as display: none in Safari, Internet Explorer, (Project Spartan needs checking) where the option is visible in dropdown, but it is not selectable.

Update (January 2016):

When the select element is required it allows use of the :invalid CSS pseudo-class which allows you to style the select element when in its "placeholder" state. :invalid works here because of the empty value in the placeholder option.

Once a value has been set, the :invalid pseudo-class will be dropped. You can optionally also use :valid if you so wish.

Most browsers support this pseudo-class. Internet Explorer 10 and later. This works best with custom styled select elements; in some cases i.e. (Mac in Chrome / Safari) you'll need to change the default appearance of the select box so that certain styles display, i.e., background-color and color. You can find some examples and more about compatibility at developer.mozilla.org.

Native element appearance Mac in Chrome:

Select box native Mac in Chrome

Using altered border element Mac in Chrome:

Altered select box Mac in Chrome

Update Git branches from master

If you've been working on a branch on-and-off, or lots has happened in other branches while you've been working on something, it's best to rebase your branch onto master. This keeps the history tidy and makes things a lot easier to follow.

git checkout master
git pull
git checkout local_branch_name
git rebase master
git push --force # force required if you've already pushed

Notes:

  • Don't rebase branches that you've collaborated with others on.
  • You should rebase on the branch to which you will be merging which may not always be master.

There's a chapter on rebasing at http://git-scm.com/book/ch3-6.html, and loads of other resources out there on the web.

Determine command line working directory when running node bin script

Current Working Directory

To get the current working directory, you can use:

process.cwd()

However, be aware that some scripts, notably gulp, will change the current working directory with process.chdir().

Node Module Path

You can get the path of the current module with:

  • __filename
  • __dirname

Original Directory (where the command was initiated)

If you are running a script from the command line, and you want the original directory from which the script was run, regardless of what directory the script is currently operating in, you can use:

process.env.INIT_CWD

Original directory, when working with NPM scripts

It's sometimes desirable to run an NPM script in the current directory, rather than the root of the project.

This variable is available inside npm package scripts as:

$INIT_CWD.

You must be running a recent version of NPM. If this variable is not available, make sure NPM is up to date.

This will allow you access the current path in your package.json, e.g.:

scripts: {
  "customScript": "gulp customScript --path $INIT_CWD"
}

Composer killed while updating

Run composer self-update and composer clearcache remove vendor and composer.lock restart your local environment and then run php -d memory_limit=-1 /usr/local/bin/composer install

How to configure log4j.properties for SpringJUnit4ClassRunner?

Add a log4j.properties(log4j.xml) file with at least one appender in root of your classpath.

The contents of the file(log4j.properties) can be as simple as

log4j.rootLogger=WARN,A1

# A1 is set to be a ConsoleAppender.
log4j.appender.A1=org.apache.log4j.ConsoleAppender
log4j.appender.A1.layout=org.apache.log4j.PatternLayout
log4j.appender.A1.layout.ConversionPattern=%d{ISO8601} [%t] %-5p %c %x - %m%n

This will enable log4j logging with default log level as WARN and use the java console to log the messages.

How do I set proxy for chrome in python webdriver?

For people out there asking how to setup proxy server in chrome which needs authentication should follow these steps.

  1. Create a proxy.py file in your project, use this code and call proxy_chrome from
    proxy.py everytime you need it. You need to pass parameters like proxy server, port and username password for authentication.

javascript unexpected identifier

In such cases, you are better off re-adding the whitespace which makes the syntax error immediate apparent:

function(){
  if(xmlhttp.readyState==4&&xmlhttp.status==200){
    document.getElementById("content").innerHTML=xmlhttp.responseText;
  }
}
xmlhttp.open("GET","data/"+id+".html",true);xmlhttp.send();
}

There's a } too many. Also, after the closing } of the function, you should add a ; before the xmlhttp.open()

And finally, I don't see what that anonymous function does up there. It's never executed or referenced. Are you sure you pasted the correct code?

The proxy server received an invalid response from an upstream server

This is not mentioned in you post but I suspect you are initiating an SSL connection from the browser to Apache, where VirtualHosts are configured, and Apache does a revese proxy to your Tomcat.

There is a serious bug in (some versions ?) of IE that sends the 'wrong' host information in an SSL connection (see EDIT below) and confuses the Apache VirtualHosts. In short the server name presented is the one of the reverse DNS resolution of the IP, not the one in the URL.

The workaround is to have one IP address per SSL virtual hosts/server name. Is short, you must end up with something like

1 server name == 1 IP address == 1 certificate == 1 Apache Virtual Host

EDIT

Though the conclusion is correct, the identification of the problem is better described here http://en.wikipedia.org/wiki/Server_Name_Indication

Check if input value is empty and display an alert

Also you can try this, if you want to focus on same text after error.

If you wants to show this error message in a paragraph then you can use this one:

 $(document).ready(function () {
    $("#submit").click(function () {
        if($('#selBooks').val() === '') {
            $("#Paragraph_id").text("Please select a book and then proceed.").show();
            $('#selBooks').focus();
            return false;
        }
    });
 });

How to create a backup of a single table in a postgres database?

I was trying to run pg_dump from within psql command prompt and I was not able to trace output file anywhere on my ubuntu 20.04 box. I tried finding by find / -name "myfilename.sql".

Instead When I tried pg_dump from /home/ubuntu, I found my output file in /home/ubuntu

How do I get a file's last modified time in Perl?

You need the stat call, and the file name:

my $last_mod_time = (stat ($file))[9];

Perl also has a different version:

my $last_mod_time = -M $file;

but that value is relative to when the program started. This is useful for things like sorting, but you probably want the first version.

How to read attribute value from XmlNode in C#?

To expand Konamiman's solution (including all relevant null checks), this is what I've been doing:

if (node.Attributes != null)
{
   var nameAttribute = node.Attributes["Name"];
   if (nameAttribute != null) 
      return nameAttribute.Value;

   throw new InvalidOperationException("Node 'Name' not found.");
}

Display UIViewController as Popup in iPhone

You can do this in Interface Builder.

  • For the view you wish to present modally set its outermost view background to transparent
  • Control + click and drag from the host view controller to the modal view controller
  • Select present modally
  • Click on the newly created segue and in the Attribute Inspector (on the right) set "Presentation" to "Over Current Context"

Do you have to put Task.Run in a method to make it async?

First, let's clear up some terminology: "asynchronous" (async) means that it may yield control back to the calling thread before it starts. In an async method, those "yield" points are await expressions.

This is very different than the term "asynchronous", as (mis)used by the MSDN documentation for years to mean "executes on a background thread".

To futher confuse the issue, async is very different than "awaitable"; there are some async methods whose return types are not awaitable, and many methods returning awaitable types that are not async.

Enough about what they aren't; here's what they are:

  • The async keyword allows an asynchronous method (that is, it allows await expressions). async methods may return Task, Task<T>, or (if you must) void.
  • Any type that follows a certain pattern can be awaitable. The most common awaitable types are Task and Task<T>.

So, if we reformulate your question to "how can I run an operation on a background thread in a way that it's awaitable", the answer is to use Task.Run:

private Task<int> DoWorkAsync() // No async because the method does not need await
{
  return Task.Run(() =>
  {
    return 1 + 2;
  });
}

(But this pattern is a poor approach; see below).

But if your question is "how do I create an async method that can yield back to its caller instead of blocking", the answer is to declare the method async and use await for its "yielding" points:

private async Task<int> GetWebPageHtmlSizeAsync()
{
  var client = new HttpClient();
  var html = await client.GetAsync("http://www.example.com/");
  return html.Length;
}

So, the basic pattern of things is to have async code depend on "awaitables" in its await expressions. These "awaitables" can be other async methods or just regular methods returning awaitables. Regular methods returning Task/Task<T> can use Task.Run to execute code on a background thread, or (more commonly) they can use TaskCompletionSource<T> or one of its shortcuts (TaskFactory.FromAsync, Task.FromResult, etc). I don't recommend wrapping an entire method in Task.Run; synchronous methods should have synchronous signatures, and it should be left up to the consumer whether it should be wrapped in a Task.Run:

private int DoWork()
{
  return 1 + 2;
}

private void MoreSynchronousProcessing()
{
  // Execute it directly (synchronously), since we are also a synchronous method.
  var result = DoWork();
  ...
}

private async Task DoVariousThingsFromTheUIThreadAsync()
{
  // I have a bunch of async work to do, and I am executed on the UI thread.
  var result = await Task.Run(() => DoWork());
  ...
}

I have an async/await intro on my blog; at the end are some good followup resources. The MSDN docs for async are unusually good, too.

Android getResources().getDrawable() deprecated API 22

Just an example of how I fixed the problem in an array to load a listView, hope it helps.

 mItems = new ArrayList<ListViewItem>();
//    Resources resources = getResources();

//    mItems.add(new ListViewItem(resources.getDrawable(R.drawable.az_lgo), getString(R.string.st_az), getString(R.string.all_nums)));
//    mItems.add(new ListViewItem(resources.getDrawable(R.drawable.ca_lgo), getString(R.string.st_ca), getString(R.string.all_nums)));
//    mItems.add(new ListViewItem(resources.getDrawable(R.drawable.co_lgo), getString(R.string.st_co), getString(R.string.all_nums)));
    mItems.add(new ListViewItem(ResourcesCompat.getDrawable(getResources(), R.drawable.az_lgo, null), getString(R.string.st_az), getString(R.string.all_nums)));
    mItems.add(new ListViewItem(ResourcesCompat.getDrawable(getResources(), R.drawable.ca_lgo, null), getString(R.string.st_ca), getString(R.string.all_nums)));
    mItems.add(new ListViewItem(ResourcesCompat.getDrawable(getResources(), R.drawable.co_lgo, null), getString(R.string.st_co), getString(R.string.all_nums)));

Pass props in Link react-router

For v5

 <Link
  to={{
    pathname: "/courses",
    search: "?sort=name",
    hash: "#the-hash",
    state: { fromDashboard: true }
  }}
/>

React Router Official Site