Programs & Examples On #Matisse

How do I extend a class with c# extension methods?

Extension methods are syntactic sugar for making static methods whose first parameter is an instance of type T look as if they were an instance method on T.

As such the benefit is largely lost where you to make 'static extension methods' since they would serve to confuse the reader of the code even more than an extension method (since they appear to be fully qualified but are not actually defined in that class) for no syntactical gain (being able to chain calls in a fluent style within Linq for example).

Since you would have to bring the extensions into scope with a using anyway I would argue that it is simpler and safer to create:

public static class DateTimeUtils
{
    public static DateTime Tomorrow { get { ... } }
}

And then use this in your code via:

WriteLine("{0}", DateTimeUtils.Tomorrow)

Count number of lines in a git repository

git diff --stat 4b825dc642cb6eb9a060e54bf8d69288fbee4904

This shows the differences from the empty tree to your current working tree. Which happens to count all lines in your current working tree.

To get the numbers in your current working tree, do this:

git diff --shortstat `git hash-object -t tree /dev/null`

It will give you a string like 1770 files changed, 166776 insertions(+).

How to sort by Date with DataTables jquery plugin?

Follow the link https://datatables.net/blog/2014-12-18

A very easy way to integrate ordering by date.

<script type="text/javascript" charset="utf8" src="https://cdnjs.cloudflare.com/ajax/libs/moment.js/2.8.4/moment.min.js"></script>
<script type="text/javascript" charset="utf8" src="https://cdn.datatables.net/plug-ins/1.10.19/sorting/datetime-moment.js"></script>

Put this code in before initializing the datatable:

$(document).ready(function () {
    // ......
    $.fn.dataTable.moment('DD-MMM-YY HH:mm:ss');
    $.fn.dataTable.moment('DD.MM.YYYY HH:mm:ss');
    // And any format you need
}

Install windows service without InstallUtil.exe

Topshelf is an OSS project which was started after this question was answered and it makes Windows service much, MUCH easier.I highly recommend looking into it.

http://topshelf-project.com/

Radio buttons and label to display in same line

My answer from a different post on the same subject should help you zend form for multicheckbox remove input from labels

Using sed to mass rename files

I wrote a small post with examples on batch renaming using sed couple of years ago:

http://www.guyrutenberg.com/2009/01/12/batch-renaming-using-sed/

For example:

for i in *; do
  mv "$i" "`echo $i | sed "s/regex/replace_text/"`";
done

If the regex contains groups (e.g. \(subregex\) then you can use them in the replacement text as \1\,\2 etc.

DSO missing from command line

DSO here means Dynamic Shared Object; since the error message says it's missing from the command line, I guess you have to add it to the command line.

That is, try adding -lpthread to your command line.

Java: splitting the filename into a base and extension

http://docs.oracle.com/javase/6/docs/api/java/io/File.html#getName()

From http://www.xinotes.org/notes/note/774/ :

Java has built-in functions to get the basename and dirname for a given file path, but the function names are not so self-apparent.

import java.io.File;

public class JavaFileDirNameBaseName {
    public static void main(String[] args) {
    File theFile = new File("../foo/bar/baz.txt");
    System.out.println("Dirname: " + theFile.getParent());
    System.out.println("Basename: " + theFile.getName());
    }
}

CREATE FILE encountered operating system error 5(failed to retrieve text for this error. Reason: 15105)

No need to do all this. Just right click on database files and add permission to everyone. That will work for sure.

Set up DNS based URL forwarding in Amazon Route53

Update

While my original answer below is still valid and might be helpful to understand the cause for DNS based URL forwarding not being available via Amazon Route 53 out of the box, I highly recommend checking out Vivek M. Chawla's utterly smart indirect solution via the meanwhile introduced Amazon S3 Support for Website Redirects and achieving a self contained server less and thus free solution within AWS only like so.

  • Implementing an automated solution to generate such redirects is left as an exercise for the reader, but please pay tribute to Vivek's epic answer by publishing your solution ;)

Original Answer

Nettica must be running a custom redirection solution for this, here is the problem:

You could create a CNAME alias like aws.example.com for myaccount.signin.aws.amazon.com, however, DNS provides no official support for aliasing a subdirectory like console in this example.

  • It's a pity that AWS doesn't appear to simply do this by default when hitting https://myaccount.signin.aws.amazon.com/ (I just tried), because it would solve you problem right away and make a lot of sense in the first place; besides, it should be pretty easy to configure on their end.

For that reason a few DNS providers have apparently implemented a custom solution to allow redirects to subdirectories; I venture the guess that they are basically facilitating a CNAME alias for a domain of their own and are redirecting again from there to the final destination via an immediate HTTP 3xx Redirection.

So to achieve the same result, you'd need to have a HTTP service running performing these redirects, which is not the simple solution one would hope for of course. Maybe/Hopefully someone can come up with a smarter approach still though.

How many values can be represented with n bits?

29 = 512 values, because that's how many combinations of zeroes and ones you can have.


What those values represent however will depend on the system you are using. If it's an unsigned integer, you will have:

000000000 = 0 (min)
000000001 = 1
...
111111110 = 510
111111111 = 511 (max)

In two's complement, which is commonly used to represent integers in binary, you'll have:

000000000 = 0
000000001 = 1
...
011111110 = 254
011111111 = 255 (max)
100000000 = -256 (min) <- yay integer overflow
100000001 = -255
...
111111110 = -2
111111111 = -1

In general, with k bits you can represent 2k values. Their range will depend on the system you are using:

Unsigned: 0 to 2k-1
Signed: -2k-1 to 2k-1-1

MySQL Fire Trigger for both Insert and Update

In response to @Zxaos request, since we can not have AND/OR operators for MySQL triggers, starting with your code, below is a complete example to achieve the same.

1. Define the INSERT trigger:

DELIMITER //
DROP TRIGGER IF EXISTS my_insert_trigger//
CREATE DEFINER=root@localhost TRIGGER my_insert_trigger
    AFTER INSERT ON `table`
    FOR EACH ROW

BEGIN
    -- Call the common procedure ran if there is an INSERT or UPDATE on `table`
    -- NEW.id is an example parameter passed to the procedure but is not required
    -- if you do not need to pass anything to your procedure.
    CALL procedure_to_run_processes_due_to_changes_on_table(NEW.id);
END//
DELIMITER ;

2. Define the UPDATE trigger

DELIMITER //
DROP TRIGGER IF EXISTS my_update_trigger//

CREATE DEFINER=root@localhost TRIGGER my_update_trigger
    AFTER UPDATE ON `table`
    FOR EACH ROW
BEGIN
    -- Call the common procedure ran if there is an INSERT or UPDATE on `table`
    CALL procedure_to_run_processes_due_to_changes_on_table(NEW.id);
END//
DELIMITER ;

3. Define the common PROCEDURE used by both these triggers:

DELIMITER //
DROP PROCEDURE IF EXISTS procedure_to_run_processes_due_to_changes_on_table//

CREATE DEFINER=root@localhost PROCEDURE procedure_to_run_processes_due_to_changes_on_table(IN table_row_id VARCHAR(255))
READS SQL DATA
BEGIN

    -- Write your MySQL code to perform when a `table` row is inserted or updated here

END//
DELIMITER ;

You note that I take care to restore the delimiter when I am done with my business defining the triggers and procedure.

How to change to an older version of Node.js

On windows 7 I used the general 'Uninstall Node.js' (just started typing in the search bottom left ,main menu field) followed by clicking the link to the older version which complies with the project, for instance: Windows 64-bit Installer: https://nodejs.org/dist/v4.4.6/node-v4.4.6-x64.msi

Visual Studio 2013 License Product Key

I solved this, without having to completely reinstall Visual Studio 2013.

For those who may come across this in the future, the following steps worked for me:

  1. Run the ISO (or vs_professional.exe).
  2. If you get the error below, you need to update the Windows Registry to trick the installer into thinking you still have the base version. If you don't get this error, skip to step 3 "The product version that you are trying to set up is earlier than the version already installed on this computer."

    • Click the link for 'examine the log file' and look near the bottom of the log, for this line: Detected related bundle ... operation: Downgrade

    • open regedit.exe and do an Edit > Find... for that GUID. In my case it was {6dff50d0-3bc3-4a92-b724-bf6d6a99de4f}. This was found in:

      HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\Windows\CurrentVersion\Uninstall{6dff50d0-3bc3-4a92-b724-bf6d6a99de4f}

    • Edit the BundleVersion value and change it to a lower version. I changed mine from 12.0.21005.13 to 12.0.21000.13: BundleVersion for Visual Studio lower the version for BundleVersion

    • Exit the registry

  3. Run the ISO (or vs_professional.exe) again. If it has a repair button like the image below, you can skip to step 4.

    Visual Studio Repair button

    • Otherwise you have to let the installer fix the registry. I did this by "installing" at least one feature, even though I think I already had all features (they were not detected). This took about 20 minutes.
  4. Run the ISO (or vs_professional.exe) again. This time repair should be visible.

  5. Click Repair and let it update your installation and apply its embedded license key. This took about 20 minutes.


Now when you run Visual Studio 2013, it should indicate that a license key was applied, under Help > Register Product:

License: Product key applied

Hope this helps somebody in the future!

Reference blog 'story'

Decimal separator comma (',') with numberDecimal inputType in EditText

This is a known bug in the Android SDK. The only workaround is to create your own soft keyboard. You can find an example of implementation here.

catching stdout in realtime from subprocess

Your problem is:

for line in p.stdout:
    print(">>> " + str(line.rstrip()))
    p.stdout.flush()

the iterator itself has extra buffering.

Try doing like this:

while True:
  line = p.stdout.readline()
  if not line:
     break
  print line

How do I rename a column in a database table using SQL?

On PostgreSQL (and many other RDBMS), you can do it with regular ALTER TABLE statement:

=> SELECT * FROM Test1;
 id | foo | bar 
----+-----+-----
  2 |   1 |   2

=> ALTER TABLE Test1 RENAME COLUMN foo TO baz;
ALTER TABLE

=> SELECT * FROM Test1;
 id | baz | bar 
----+-----+-----
  2 |   1 |   2

How to check if running as root in a bash script

As @wrikken mentioned in his comments, id -u is a much better check for root.

In addition, with proper use of sudo, you could have the script check and see if it is running as root. If not, have it recall itself via sudo and then run with root permissions.

Depending on what the script does, another option may be to set up a sudo entry for whatever specialized commands the script may need.

How to import CSV file data into a PostgreSQL table?

Use this SQL code

    copy table_name(atribute1,attribute2,attribute3...)
    from 'E:\test.csv' delimiter ',' csv header

the header keyword lets the DBMS know that the csv file have a header with attributes

for more visit http://www.postgresqltutorial.com/import-csv-file-into-posgresql-table/

How to get the focused element with jQuery?

I've tested two ways in Firefox, Chrome, IE9 and Safari.

(1). $(document.activeElement) works as expected in Firefox, Chrome and Safari.

(2). $(':focus') works as expected in Firefox and Safari.

I moved into the mouse to input 'name' and pressed Enter on keyboard, then I tried to get the focused element.

(1). $(document.activeElement) returns the input:text:name as expected in Firefox, Chrome and Safari, but it returns input:submit:addPassword in IE9

(2). $(':focus') returns input:text:name as expected in Firefox and Safari, but nothing in IE

<form action="">
    <div id="block-1" class="border">
        <h4>block-1</h4>
        <input type="text" value="enter name here" name="name"/>            
        <input type="button" value="Add name" name="addName"/>
    </div>
    <div id="block-2" class="border">
        <h4>block-2</h4>
        <input type="text" value="enter password here" name="password"/>            
        <input type="submit" value="Add password" name="addPassword"/>
    </div>
</form>

Creating a DateTime in a specific Time Zone in c#

I like Jon Skeet's answer, but would like to add one thing. I'm not sure if Jon was expecting the ctor to always be passed in the Local timezone. But I want to use it for cases where it's something other then local.

I'm reading values from a database, and I know what timezone that database is in. So in the ctor, I'll pass in the timezone of the database. But then I would like the value in local time. Jon's LocalTime does not return the original date converted into a local timezone date. It returns the date converted into the original timezone (whatever you had passed into the ctor).

I think these property names clear it up...

public DateTime TimeInOriginalZone { get { return TimeZoneInfo.ConvertTime(utcDateTime, timeZone); } }
public DateTime TimeInLocalZone    { get { return TimeZoneInfo.ConvertTime(utcDateTime, TimeZoneInfo.Local); } }
public DateTime TimeInSpecificZone(TimeZoneInfo tz)
{
    return TimeZoneInfo.ConvertTime(utcDateTime, tz);
}

CSS @media print issues with background-color;

For Chrome:::::::::::::::::

Ctrl+P => Select the Click On More Settings => In the Options Menu Select the Background and Graphics Options

                      :) Will Work

**Why wasn't it working!Reason:**Chrome Browser had Fonts And Headers Enabled

General Case:::::

When you dont need to turn on this option manually.In body in CSS type:::::

-webkit-print-color-adjust:exact !important;

:)Works

How can I make a menubar fixed on the top while scrolling

 #header {
        top:0;
        width:100%;
        position:fixed;
        background-color:#FFF;
    }

    #content {
        position:static;
        margin-top:100px;
    }

Is Python faster and lighter than C++?

It's the same problem with managed and easy to use programming language as always - they are slow (and sometimes memory-eating).

These are languages to do control rather than processing. If I would have to write application to transform images and had to use Python too all the processing could be written in C++ and connected to Python via bindings while interface and process control would be definetely Python.

How to write to file in Ruby?

This is preferred approach in most cases:

 File.open(yourfile, 'w') { |file| file.write("your text") }

When a block is passed to File.open, the File object will be automatically closed when the block terminates.

If you don't pass a block to File.open, you have to make sure that file is correctly closed and the content was written to file.

begin
  file = File.open("/tmp/some_file", "w")
  file.write("your text") 
rescue IOError => e
  #some error occur, dir not writable etc.
ensure
  file.close unless file.nil?
end

You can find it in documentation:

static VALUE rb_io_s_open(int argc, VALUE *argv, VALUE klass)
{
    VALUE io = rb_class_new_instance(argc, argv, klass);
    if (rb_block_given_p()) {
        return rb_ensure(rb_yield, io, io_close, io);
    }
    return io;
}

How to run only one task in ansible playbook?

are you familiar with handlers? I think it's what you are looking for. Move the restart from hadoop_master.yml to roles/hadoop_primary/handlers/main.yml:

- name: start hadoop jobtracker services
  service: name=hadoop-0.20-mapreduce-jobtracker state=started

and now call use notify in hadoop_master.yml:

- name: Install the namenode and jobtracker packages
  apt: name={{item}} force=yes state=latest
  with_items: 
   - hadoop-0.20-mapreduce-jobtracker
   - hadoop-hdfs-namenode
   - hadoop-doc
   - hue-plugins
  notify: start hadoop jobtracker services

Checking whether a variable is an integer or not

If you want to check that a string consists of only digits, but converting to an int won't help, you can always just use regex.

import re
x = "01234"
match = re.search("^\d+$", x)
try: x = match.group(0)
except AttributeError: print("not a valid number")

Result: x == "01234"

In this case, if x were "hello", converting it to a numeric type would throw a ValueError, but data would also be lost in the process. Using a regex and catching an AttributeError would allow you to confirm numeric characters in a string with, for instance, leading 0's.

If you didn't want it to throw an AttributeError, but instead just wanted to look for more specific problems, you could vary the regex and just check the match:

import re
x = "h01234"
match = re.search("\D", x)
if not match:
    print("x is a number")
else:
    print("encountered a problem at character:", match.group(0))

Result: "encountered a problem at character: h"

That actually shows you where the problem occurred without the use of exceptions. Again, this is not for testing the type, but rather the characters themselves. This gives you much more flexibility than simply checking for types, especially when converting between types can lose important string data, like leading 0's.

Uncaught TypeError: Cannot set property 'value' of null

The problem may where the code is being executed. If you are in the head of a document executing JavaScript, even when you have an element with id="u" in your web page, the code gets executed before the DOM is finished loading, and so none of the HTML really exists yet... You can fix this by moving your code to the end of the page just above the closing html tag. This is one good reason to use jQuery.

Upgrade Node.js to the latest version on Mac OS

Upgrade the version of node without installing any package, not even nvm itself:

sudo npx n stable

Explanations:
This approach is similar to Johan Dettmar's answer. The only difference is here the package n is not installed glabally in the local machine.

How can I change cols of textarea in twitter-bootstrap?

Simply add the bootstrap "row-fluid" class to the textarea. It will stretch to 100% width;

Update: For bootstrap 3.x use "col-xs-12" class for textarea;

Update II: Also if you want to extend the container to full width use: container-fluid class.

Is it possible to have multiple styles inside a TextView?

As stated, use TextView.setText(Html.fromHtml(String))

And use these tags in your Html formatted string:

<a href="...">
<b>
<big>
<blockquote>
<br>
<cite>
<dfn>
<div align="...">
<em>
<font size="..." color="..." face="...">
<h1>
<h2>
<h3>
<h4>
<h5>
<h6>
<i>
<img src="...">
<p>
<small>
<strike>
<strong>
<sub>
<sup>
<tt>
<u>

http://commonsware.com/blog/Android/2010/05/26/html-tags-supported-by-textview.html

Javascript Array.sort implementation?

After some more research, it appears, for Mozilla/Firefox, that Array.sort() uses mergesort. See the code here.

Select all columns except one in MySQL?

While trying the solutions by @Mahomedalid and @Junaid I found a problem. So thought of sharing it. If the column name is having spaces or hyphens like check-in then the query will fail. The simple workaround is to use backtick around column names. The modified query is below

SET @SQL = CONCAT('SELECT ', (SELECT GROUP_CONCAT(CONCAT("`", COLUMN_NAME, "`")) FROM
INFORMATION_SCHEMA.COLUMNS WHERE TABLE_NAME = 'users' AND COLUMN_NAME NOT IN ('id')), ' FROM users');
PREPARE stmt1 FROM @SQL;
EXECUTE stmt1;

Printing a java map Map<String, Object> - How?

I'm sure there's some nice library that does this sort of thing already for you... But to just stick with the approach you're already going with, Map#entrySet gives you a combined Object with the key and the value. So something like:

for (Map.Entry<String, Object> entry : map.entrySet()) {
    System.out.println(entry.getKey() + ":" + entry.getValue().toString());
}

will do what you're after.


If you're using java 8, there's also the new streaming approach.

map.forEach((key, value) -> System.out.println(key + ":" + value));

Tar a directory, but don't store full absolute paths in the archive

The following command will create a root directory "." and put all the files from the specified directory into it.

tar -cjf site1.tar.bz2 -C /var/www/site1 .

If you want to put all files in root of the tar file, @chinthaka is right. Just cd in to the directory and do:

tar -cjf target_path/file.tar.gz *

This will put all the files in the cwd to the tar file as root files.

Test if numpy array contains only zeros

As another answer says, you can take advantage of truthy/falsy evaluations if you know that 0 is the only falsy element possibly in your array. All elements in an array are falsy iff there are not any truthy elements in it.*

>>> a = np.zeros(10)
>>> not np.any(a)
True

However, the answer claimed that any was faster than other options due partly to short-circuiting. As of 2018, Numpy's all and any do not short-circuit.

If you do this kind of thing often, it's very easy to make your own short-circuiting versions using numba:

import numba as nb

# short-circuiting replacement for np.any()
@nb.jit(nopython=True)
def sc_any(array):
    for x in array.flat:
        if x:
            return True
    return False

# short-circuiting replacement for np.all()
@nb.jit(nopython=True)
def sc_all(array):
    for x in array.flat:
        if not x:
            return False
    return True

These tend to be faster than Numpy's versions even when not short-circuiting. count_nonzero is the slowest.

Some input to check performance:

import numpy as np

n = 10**8
middle = n//2
all_0 = np.zeros(n, dtype=int)
all_1 = np.ones(n, dtype=int)
mid_0 = np.ones(n, dtype=int)
mid_1 = np.zeros(n, dtype=int)
np.put(mid_0, middle, 0)
np.put(mid_1, middle, 1)
# mid_0 = [1 1 1 ... 1 0 1 ... 1 1 1]
# mid_1 = [0 0 0 ... 0 1 0 ... 0 0 0]

Check:

## count_nonzero
%timeit np.count_nonzero(all_0) 
# 220 ms ± 8.73 ms per loop (mean ± std. dev. of 7 runs, 1 loop each)
%timeit np.count_nonzero(all_1)
# 150 ms ± 4.56 ms per loop (mean ± std. dev. of 7 runs, 10 loops each)

### all
# np.all
%timeit np.all(all_1)
%timeit np.all(mid_0)
%timeit np.all(all_0)
# 56.8 ms ± 3.41 ms per loop (mean ± std. dev. of 7 runs, 10 loops each)
# 57.4 ms ± 1.76 ms per loop (mean ± std. dev. of 7 runs, 10 loops each)
# 55.9 ms ± 2.13 ms per loop (mean ± std. dev. of 7 runs, 10 loops each)

# sc_all
%timeit sc_all(all_1)
%timeit sc_all(mid_0)
%timeit sc_all(all_0)
# 44.4 ms ± 2.49 ms per loop (mean ± std. dev. of 7 runs, 10 loops each)
# 22.7 ms ± 599 µs per loop (mean ± std. dev. of 7 runs, 10 loops each)
# 288 ns ± 6.36 ns per loop (mean ± std. dev. of 7 runs, 1000000 loops each)

### any
# np.any
%timeit np.any(all_0)
%timeit np.any(mid_1)
%timeit np.any(all_1)
# 60.7 ms ± 1.38 ms per loop (mean ± std. dev. of 7 runs, 10 loops each)
# 60 ms ± 287 µs per loop (mean ± std. dev. of 7 runs, 10 loops each)
# 57.7 ms ± 1.12 ms per loop (mean ± std. dev. of 7 runs, 10 loops each)

# sc_any
%timeit sc_any(all_0)
%timeit sc_any(mid_1)
%timeit sc_any(all_1)
# 41.7 ms ± 1.24 ms per loop (mean ± std. dev. of 7 runs, 10 loops each)
# 22.4 ms ± 1.51 ms per loop (mean ± std. dev. of 7 runs, 10 loops each)
# 287 ns ± 12.7 ns per loop (mean ± std. dev. of 7 runs, 1000000 loops each)

* Helpful all and any equivalences:

np.all(a) == np.logical_not(np.any(np.logical_not(a)))
np.any(a) == np.logical_not(np.all(np.logical_not(a)))
not np.all(a) == np.any(np.logical_not(a))
not np.any(a) == np.all(np.logical_not(a))

How to detect when keyboard is shown and hidden

If you have more then one UITextFields and you need to do something when (or before) keyboard appears or disappears, you can implement this approach.

Add UITextFieldDelegate to your class. Assign integer counter, let's say:

NSInteger editCounter; 

Set this counter to zero somewhere in viewDidLoad. Then, implement textFieldShouldBeginEditing and textFieldShouldEndEditing delegate methods.

In the first one add 1 to editCounter. If value of editCounter becomes 1 - this means that keyboard will appear (in case if you return YES). If editCounter > 1 - this means that keyboard is already visible and another UITextField holds the focus.

In textFieldShouldEndEditing subtract 1 from editCounter. If you get zero - keyboard will be dismissed, otherwise it will remain on the screen.

Can I add a UNIQUE constraint to a PostgreSQL table, after it's already created?

If you had a table that already had a existing constraints based on lets say: name and lastname and you wanted to add one more unique constraint, you had to drop the entire constrain by:

ALTER TABLE your_table DROP CONSTRAINT constraint_name;

Make sure tha the new constraint you wanted to add is unique/ not null ( if its Microsoft Sql, it can contain only one null value) across all data on that table, and then you could re-create it.

ALTER TABLE table_name
ADD CONSTRAINT constraint_name UNIQUE (column1, column2, ... column_n);

Group by in LINQ

You can also Try this:

var results= persons.GroupBy(n => new { n.PersonId, n.car})
                .Select(g => new {
                               g.Key.PersonId,
                               g.Key.car)}).ToList();

Loop over html table and get checked checkboxes (JQuery)

The following code snippet enables/disables a button depending on whether at least one checkbox on the page has been checked.
$('input[type=checkbox]').change(function () {
    $('#test > tbody  tr').each(function () {
        if ($('input[type=checkbox]').is(':checked')) {
            $('#btnexcellSelect').removeAttr('disabled');
        } else {
            $('#btnexcellSelect').attr('disabled', 'disabled');
        }
        if ($(this).is(':checked')){
            console.log( $(this).attr('id'));
         }else{
             console.log($(this).attr('id'));
         }
     });
});

Here is demo in JSFiddle.

How do I use reflection to invoke a private method?

Microsoft recently modified the reflection API rendering most of these answers obsolete. The following should work on modern platforms (including Xamarin.Forms and UWP):

obj.GetType().GetTypeInfo().GetDeclaredMethod("MethodName").Invoke(obj, yourArgsHere);

Or as an extension method:

public static object InvokeMethod<T>(this T obj, string methodName, params object[] args)
{
    var type = typeof(T);
    var method = type.GetTypeInfo().GetDeclaredMethod(methodName);
    return method.Invoke(obj, args);
}

Note:

  • If the desired method is in a superclass of obj the T generic must be explicitly set to the type of the superclass.

  • If the method is asynchronous you can use await (Task) obj.InvokeMethod(…).

What is a non-capturing group in regular expressions?

I cannot comment on the top answers to say this: I would like to add an explicit point which is only implied in the top answers:

The non-capturing group (?...) does not remove any characters from the original full match, it only reorganises the regex visually to the programmer.

To access a specific part of the regex without defined extraneous characters you would always need to use .group(<index>)

On design patterns: When should I use the singleton?

It can be very pragmatic to configure specific infrastructure concerns as singletons or global variables. My favourite example of this is Dependency Injection frameworks that make use of singletons to act as a connection point to the framework.

In this case you are taking a dependency on the infrastructure to simplify using the library and avoid unneeded complexity.

Android - Center TextView Horizontally in LinearLayout

Just use: android:layout_centerHorizontal="true"

It will put the whole textview in the center

Delete a closed pull request from GitHub

5 step to do what you want if you made the pull request from a forked repository:

  1. reopen the pull request
  2. checkout to the branch which you made the pull request
  3. reset commit to the last master commit(that means remove all you new code)
  4. git push --force
  5. delete your forked repository which made the pull request

And everything is done, good luck!

Django DateField default options

I think a better way to solve this would be to use the datetime callable:

from datetime import datetime

date = models.DateField(default=datetime.now)

Note that no parenthesis were used. If you used parenthesis you would invoke the now() function just once (when the model is created). Instead, you pass the callable as an argument, thus being invoked everytime an instance of the model is created.

Credit to Django Musings. I've used it and works fine.

What is the difference between print and puts?

If you would like to output array within string using puts, you will get the same result as if you were using print:

puts "#{[0, 1, nil]}":
[0, 1, nil]

But if not withing a quoted string then yes. The only difference is between new line when we use puts.

Submit two forms with one button

A form submission causes the page to navigate away to the action of the form. So, you cannot submit both forms in the traditional way. If you try to do so with JavaScript by calling form.submit() on each form in succession, each request will be aborted except for the last submission. So, you need to submit the first form asynchronously via JavaScript:

var f = document.forms.updateDB;
var postData = [];
for (var i = 0; i < f.elements.length; i++) {
    postData.push(f.elements[i].name + "=" + f.elements[i].value);
}
var xhr = new XMLHttpRequest();
xhr.open("POST", "mypage.php", true);
xhr.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
xhr.send(postData.join("&"));

document.forms.payPal.submit();

How to get client IP address in Laravel 5+

If you are still getting 127.0.0.1 as the IP, you need to add your "proxy", but be aware that you have to change it before going into production!

Read "Configuring Trusted Proxies".

And add this:

class TrustProxies extends Middleware
{
    /**
     * The trusted proxies for this application.
     *
     * @var array
     */
    protected $proxies = '*';

Now request()->ip() gives you the correct IP.

How can I select multiple columns from a subquery (in SQL Server) that should have one record (select top 1) for each record in the main query?

You'll have to make a join:

SELECT A.SalesOrderID, B.Foo
FROM A
JOIN B bo ON bo.id = (
     SELECT TOP 1 id
     FROM B bi
     WHERE bi.SalesOrderID = a.SalesOrderID
     ORDER BY bi.whatever
     )
WHERE A.Date BETWEEN '2000-1-4' AND '2010-1-4'

, assuming that b.id is a PRIMARY KEY on B

In MS SQL 2005 and higher you may use this syntax:

SELECT SalesOrderID, Foo
FROM (
  SELECT A.SalesOrderId, B.Foo,
         ROW_NUMBER() OVER (PARTITION BY B.SalesOrderId ORDER BY B.whatever) AS rn
  FROM A
  JOIN B ON B.SalesOrderID = A.SalesOrderID
  WHERE A.Date BETWEEN '2000-1-4' AND '2010-1-4'
) i
WHERE rn

This will select exactly one record from B for each SalesOrderId.

JavaScript code for getting the selected value from a combo box

There is an unnecessary hashtag; change the code to this:

var e = document.getElementById("ticket_category_clone").value;

What is the use of System.in.read()?

System is a final class in java.lang package

code sample from the source code of api

public final class System {

   /**
     * The "standard" input stream. This stream is already
     * open and ready to supply input data. Typically this stream
     * corresponds to keyboard input or another input source specified by
     * the host environment or user.
     */
    public final static InputStream in = nullInputStream();

}

read() is an abstract method of abstract class InputStream

 /**
     * Reads the next byte of data from the input stream. The value byte is
     * returned as an <code>int</code> in the range <code>0</code> to
     * <code>255</code>. If no byte is available because the end of the stream
     * has been reached, the value <code>-1</code> is returned. This method
     * blocks until input data is available, the end of the stream is detected,
     * or an exception is thrown.
     *
     * <p> A subclass must provide an implementation of this method.
     *
     * @return     the next byte of data, or <code>-1</code> if the end of the
     *             stream is reached.
     * @exception  IOException  if an I/O error occurs.
     */
    public abstract int read() throws IOException;

In short from the api:

Reads some number of bytes from the input stream and stores them into the buffer array b. The number of bytes actually read is returned as an integer. This method blocks until input data is available, end of file is detected, or an exception is thrown.

from InputStream.html#read()

Java: Static vs inner class

static inner class: can declare static & non static members but can only access static members of its parents class.

non static inner class: can declare only non static members but can access static and non static member of its parent class.

If list index exists, do X

ok, so I think it's actually possible (for the sake of argument):

>>> your_list = [5,6,7]
>>> 2 in zip(*enumerate(your_list))[0]
True
>>> 3 in zip(*enumerate(your_list))[0]
False

Python JSON serialize a Decimal object

I tried switching from simplejson to builtin json for GAE 2.7, and had issues with the decimal. If default returned str(o) there were quotes (because _iterencode calls _iterencode on the results of default), and float(o) would remove trailing 0.

If default returns an object of a class that inherits from float (or anything that calls repr without additional formatting) and has a custom __repr__ method, it seems to work like I want it to.

import json
from decimal import Decimal

class fakefloat(float):
    def __init__(self, value):
        self._value = value
    def __repr__(self):
        return str(self._value)

def defaultencode(o):
    if isinstance(o, Decimal):
        # Subclass float with custom repr?
        return fakefloat(o)
    raise TypeError(repr(o) + " is not JSON serializable")

json.dumps([10.20, "10.20", Decimal('10.20')], default=defaultencode)
'[10.2, "10.20", 10.20]'

Java - Get a list of all Classes loaded in the JVM

It's not a programmatic solution but you can run

java -verbose:class ....

and the JVM will dump out what it's loading, and from where.

[Opened /usr/java/j2sdk1.4.1/jre/lib/rt.jar]
[Opened /usr/java/j2sdk1.4.1/jre/lib/sunrsasign.jar]
[Opened /usr/java/j2sdk1.4.1/jre/lib/jsse.jar]
[Opened /usr/java/j2sdk1.4.1/jre/lib/jce.jar]
[Opened /usr/java/j2sdk1.4.1/jre/lib/charsets.jar]
[Loaded java.lang.Object from /usr/java/j2sdk1.4.1/jre/lib/rt.jar]
[Loaded java.io.Serializable from /usr/java/j2sdk1.4.1/jre/lib/rt.jar]
[Loaded java.lang.Comparable from /usr/java/j2sdk1.4.1/jre/lib/rt.jar]
[Loaded java.lang.CharSequence from /usr/java/j2sdk1.4.1/jre/lib/rt.jar]
[Loaded java.lang.String from /usr/java/j2sdk1.4.1/jre/lib/rt.jar]

See here for more details.

What's the difference between abstraction and encapsulation?

Difference between Abstraction and Encapsulation :-

Abstraction

  1. Abstraction solves the problem in the design level.
  2. Abstraction is used for hiding the unwanted data and giving relevant data.
  3. Abstraction lets you focus on what the object does instead of how it does it.
  4. Abstraction- Outer layout, used in terms of design. For Example:- Outer Look of a Mobile Phone, like it has a display screen and keypad buttons to dial a number.

Encapsulation

  1. Encapsulation solves the problem in the implementation level.
  2. Encapsulation means hiding the code and data into a single unit to protect the data from outside world.
  3. Encapsulation means hiding the internal details or mechanics of how an object does something.
  4. Encapsulation- Inner layout, used in terms of implementation. For Example:- Inner Implementation detail of a Mobile Phone, how keypad button and Display Screen are connect with each other using circuits.

How to get PID of process I've just started within java program?

Include jna (both "JNA" and "JNA Platform") in your library and use this function:

import com.sun.jna.Pointer;
import com.sun.jna.platform.win32.Kernel32;
import com.sun.jna.platform.win32.WinNT;
import java.lang.reflect.Field;

public static long getProcessID(Process p)
    {
        long result = -1;
        try
        {
            //for windows
            if (p.getClass().getName().equals("java.lang.Win32Process") ||
                   p.getClass().getName().equals("java.lang.ProcessImpl")) 
            {
                Field f = p.getClass().getDeclaredField("handle");
                f.setAccessible(true);              
                long handl = f.getLong(p);
                Kernel32 kernel = Kernel32.INSTANCE;
                WinNT.HANDLE hand = new WinNT.HANDLE();
                hand.setPointer(Pointer.createConstant(handl));
                result = kernel.GetProcessId(hand);
                f.setAccessible(false);
            }
            //for unix based operating systems
            else if (p.getClass().getName().equals("java.lang.UNIXProcess")) 
            {
                Field f = p.getClass().getDeclaredField("pid");
                f.setAccessible(true);
                result = f.getLong(p);
                f.setAccessible(false);
            }
        }
        catch(Exception ex)
        {
            result = -1;
        }
        return result;
    }

You can also download JNA from here and JNA Platform from here.

How to use parameters with HttpPost

You can also use this approach in case you want to pass some http parameters and send a json request:

(note: I have added in some extra code just incase it helps any other future readers)

public void postJsonWithHttpParams() throws URISyntaxException, UnsupportedEncodingException, IOException {

    //add the http parameters you wish to pass
    List<NameValuePair> postParameters = new ArrayList<>();
    postParameters.add(new BasicNameValuePair("param1", "param1_value"));
    postParameters.add(new BasicNameValuePair("param2", "param2_value"));

    //Build the server URI together with the parameters you wish to pass
    URIBuilder uriBuilder = new URIBuilder("http://google.ug");
    uriBuilder.addParameters(postParameters);

    HttpPost postRequest = new HttpPost(uriBuilder.build());
    postRequest.setHeader("Content-Type", "application/json");

    //this is your JSON string you are sending as a request
    String yourJsonString = "{\"str1\":\"a value\",\"str2\":\"another value\"} ";

    //pass the json string request in the entity
    HttpEntity entity = new ByteArrayEntity(yourJsonString.getBytes("UTF-8"));
    postRequest.setEntity(entity);

    //create a socketfactory in order to use an http connection manager
    PlainConnectionSocketFactory plainSocketFactory = PlainConnectionSocketFactory.getSocketFactory();
    Registry<ConnectionSocketFactory> connSocketFactoryRegistry = RegistryBuilder.<ConnectionSocketFactory>create()
            .register("http", plainSocketFactory)
            .build();

    PoolingHttpClientConnectionManager connManager = new PoolingHttpClientConnectionManager(connSocketFactoryRegistry);

    connManager.setMaxTotal(20);
    connManager.setDefaultMaxPerRoute(20);

    RequestConfig defaultRequestConfig = RequestConfig.custom()
            .setSocketTimeout(HttpClientPool.connTimeout)
            .setConnectTimeout(HttpClientPool.connTimeout)
            .setConnectionRequestTimeout(HttpClientPool.readTimeout)
            .build();

    // Build the http client.
    CloseableHttpClient httpclient = HttpClients.custom()
            .setConnectionManager(connManager)
            .setDefaultRequestConfig(defaultRequestConfig)
            .build();

    CloseableHttpResponse response = httpclient.execute(postRequest);

    //Read the response
    String responseString = "";

    int statusCode = response.getStatusLine().getStatusCode();
    String message = response.getStatusLine().getReasonPhrase();

    HttpEntity responseHttpEntity = response.getEntity();

    InputStream content = responseHttpEntity.getContent();

    BufferedReader buffer = new BufferedReader(new InputStreamReader(content));
    String line;

    while ((line = buffer.readLine()) != null) {
        responseString += line;
    }

    //release all resources held by the responseHttpEntity
    EntityUtils.consume(responseHttpEntity);

    //close the stream
    response.close();

    // Close the connection manager.
    connManager.close();
}

Speed comparison with Project Euler: C vs Python vs Erlang vs Haskell

Some more numbers and explanations for the C version. Apparently noone did it during all those years. Remember to upvote this answer so it can get on top for everyone to see and learn.

Step One: Benchmark of the author's programs

Laptop Specifications:

  • CPU i3 M380 (931 MHz - maximum battery saving mode)
  • 4GB memory
  • Win7 64 bits
  • Microsoft Visual Studio 2012 Ultimate
  • Cygwin with gcc 4.9.3
  • Python 2.7.10

Commands:

compiling on VS x64 command prompt > `for /f %f in ('dir /b *.c') do cl /O2 /Ot /Ox %f -o %f_x64_vs2012.exe`
compiling on cygwin with gcc x64   > `for f in ./*.c; do gcc -m64 -O3 $f -o ${f}_x64_gcc.exe ; done`
time (unix tools) using cygwin > `for f in ./*.exe; do  echo "----------"; echo $f ; time $f ; done`

.

----------
$ time python ./original.py

real    2m17.748s
user    2m15.783s
sys     0m0.093s
----------
$ time ./original_x86_vs2012.exe

real    0m8.377s
user    0m0.015s
sys     0m0.000s
----------
$ time ./original_x64_vs2012.exe

real    0m8.408s
user    0m0.000s
sys     0m0.015s
----------
$ time ./original_x64_gcc.exe

real    0m20.951s
user    0m20.732s
sys     0m0.030s

Filenames are: integertype_architecture_compiler.exe

  • integertype is the same as the original program for now (more on that later)
  • architecture is x86 or x64 depending on the compiler settings
  • compiler is gcc or vs2012

Step Two: Investigate, Improve and Benchmark Again

VS is 250% faster than gcc. The two compilers should give a similar speed. Obviously, something is wrong with the code or the compiler options. Let's investigate!

The first point of interest is the integer types. Conversions can be expensive and consistency is important for better code generation & optimizations. All integers should be the same type.

It's a mixed mess of int and long right now. We're going to improve that. What type to use? The fastest. Gotta benchmark them'all!

----------
$ time ./int_x86_vs2012.exe

real    0m8.440s
user    0m0.016s
sys     0m0.015s
----------
$ time ./int_x64_vs2012.exe

real    0m8.408s
user    0m0.016s
sys     0m0.015s
----------
$ time ./int32_x86_vs2012.exe

real    0m8.408s
user    0m0.000s
sys     0m0.015s
----------
$ time ./int32_x64_vs2012.exe

real    0m8.362s
user    0m0.000s
sys     0m0.015s
----------
$ time ./int64_x86_vs2012.exe

real    0m18.112s
user    0m0.000s
sys     0m0.015s
----------
$ time ./int64_x64_vs2012.exe

real    0m18.611s
user    0m0.000s
sys     0m0.015s
----------
$ time ./long_x86_vs2012.exe

real    0m8.393s
user    0m0.015s
sys     0m0.000s
----------
$ time ./long_x64_vs2012.exe

real    0m8.440s
user    0m0.000s
sys     0m0.015s
----------
$ time ./uint32_x86_vs2012.exe

real    0m8.362s
user    0m0.000s
sys     0m0.015s
----------
$ time ./uint32_x64_vs2012.exe

real    0m8.393s
user    0m0.015s
sys     0m0.015s
----------
$ time ./uint64_x86_vs2012.exe

real    0m15.428s
user    0m0.000s
sys     0m0.015s
----------
$ time ./uint64_x64_vs2012.exe

real    0m15.725s
user    0m0.015s
sys     0m0.015s
----------
$ time ./int_x64_gcc.exe

real    0m8.531s
user    0m8.329s
sys     0m0.015s
----------
$ time ./int32_x64_gcc.exe

real    0m8.471s
user    0m8.345s
sys     0m0.000s
----------
$ time ./int64_x64_gcc.exe

real    0m20.264s
user    0m20.186s
sys     0m0.015s
----------
$ time ./long_x64_gcc.exe

real    0m20.935s
user    0m20.809s
sys     0m0.015s
----------
$ time ./uint32_x64_gcc.exe

real    0m8.393s
user    0m8.346s
sys     0m0.015s
----------
$ time ./uint64_x64_gcc.exe

real    0m16.973s
user    0m16.879s
sys     0m0.030s

Integer types are int long int32_t uint32_t int64_t and uint64_t from #include <stdint.h>

There are LOTS of integer types in C, plus some signed/unsigned to play with, plus the choice to compile as x86 or x64 (not to be confused with the actual integer size). That is a lot of versions to compile and run ^^

Step Three: Understanding the Numbers

Definitive conclusions:

  • 32 bits integers are ~200% faster than 64 bits equivalents
  • unsigned 64 bits integers are 25 % faster than signed 64 bits (Unfortunately, I have no explanation for that)

Trick question: "What are the sizes of int and long in C?"
The right answer is: The size of int and long in C are not well-defined!

From the C spec:

int is at least 32 bits
long is at least an int

From the gcc man page (-m32 and -m64 flags):

The 32-bit environment sets int, long and pointer to 32 bits and generates code that runs on any i386 system.
The 64-bit environment sets int to 32 bits and long and pointer to 64 bits and generates code for AMD’s x86-64 architecture.

From MSDN documentation (Data Type Ranges) https://msdn.microsoft.com/en-us/library/s3f49ktz%28v=vs.110%29.aspx :

int, 4 bytes, also knows as signed
long, 4 bytes, also knows as long int and signed long int

To Conclude This: Lessons Learned

  • 32 bits integers are faster than 64 bits integers.

  • Standard integers types are not well defined in C nor C++, they vary depending on compilers and architectures. When you need consistency and predictability, use the uint32_t integer family from #include <stdint.h>.

  • Speed issues solved. All other languages are back hundreds percent behind, C & C++ win again ! They always do. The next improvement will be multithreading using OpenMP :D

How can I pass a list as a command-line argument with argparse?

I want to handle passing multiple lists, integer values and strings.

Helpful link => How to pass a Bash variable to Python?

def main(args):
    my_args = []
    for arg in args:
        if arg.startswith("[") and arg.endswith("]"):
            arg = arg.replace("[", "").replace("]", "")
            my_args.append(arg.split(","))
        else:
            my_args.append(arg)

    print(my_args)


if __name__ == "__main__":
    import sys
    main(sys.argv[1:])

Order is not important. If you want to pass a list just do as in between "[" and "] and seperate them using a comma.

Then,

python test.py my_string 3 "[1,2]" "[3,4,5]"

Output => ['my_string', '3', ['1', '2'], ['3', '4', '5']], my_args variable contains the arguments in order.

How to reload current page in ReactJS?

Since React eventually boils down to plain old JavaScript, you can really place it anywhere! For instance, you could place it on a componentDidMount() in a React class.

For you edit, you may want to try something like this:

class Component extends React.Component {
  constructor(props) {
    super(props);
    this.onAddBucket = this.onAddBucket.bind(this);
  }
  componentWillMount() {
    this.setState({
      buckets: {},
    })
  }
  componentDidMount() {
    this.onAddBucket();
  }
  onAddBucket() {
    let self = this;
    let getToken = localStorage.getItem('myToken');
    var apiBaseUrl = "...";
    let input = {
      "name" :  this.state.fields["bucket_name"]
    }
    axios.defaults.headers.common['Authorization'] = getToken;
    axios.post(apiBaseUrl+'...',input)
    .then(function (response) {
      if (response.data.status == 200) {
        this.setState({
          buckets: this.state.buckets.concat(response.data.buckets),
        });
      } else {
        alert(response.data.message);
      }
    })
    .catch(function (error) {
      console.log(error);
    });
  }
  render() {
    return (
      {this.state.bucket}
    );
  }
}

Convert .class to .java

Invoking javap to read the bytecode

The javap command takes class-names without the .class extension. Try

javap -c ClassName

Converting .class files back to .java files

javap will however not give you the implementations of the methods in java-syntax. It will at most give it to you in JVM bytecode format.

To actually decompile (i.e., do the reverse of javac) you will have to use proper decompiler. See for instance the following related question:

pySerial write() won't take my string

I had the same "TypeError: an integer is required" error message when attempting to write. Thanks, the .encode() solved it for me. I'm running python 3.4 on a Dell D530 running 32 bit Windows XP Pro.

I'm omitting the com port settings here:

>>>import serial

>>>ser = serial.Serial(5)

>>>ser.close()

>>>ser.open()

>>>ser.write("1".encode())

1

>>>

How to construct a relative path in Java from two absolute paths (or URLs)?

Recursion produces a smaller solution. This throws an exception if the result is impossible (e.g. different Windows disk) or impractical (root is only common directory.)

/**
 * Computes the path for a file relative to a given base, or fails if the only shared 
 * directory is the root and the absolute form is better.
 * 
 * @param base File that is the base for the result
 * @param name File to be "relativized"
 * @return the relative name
 * @throws IOException if files have no common sub-directories, i.e. at best share the
 *                     root prefix "/" or "C:\"
 */

public static String getRelativePath(File base, File name) throws IOException  {
    File parent = base.getParentFile();

    if (parent == null) {
        throw new IOException("No common directory");
    }

    String bpath = base.getCanonicalPath();
    String fpath = name.getCanonicalPath();

    if (fpath.startsWith(bpath)) {
        return fpath.substring(bpath.length() + 1);
    } else {
        return (".." + File.separator + getRelativePath(parent, name));
    }
}

Detect whether a Python string is a number or a letter

For a string of length 1 you can simply perform isdigit() or isalpha()

If your string length is greater than 1, you can make a function something like..

def isinteger(a):
    try:
        int(a)
        return True
    except ValueError:
        return False

Filter values only if not null using lambda in Java8

In this particular example I think @Tagir is 100% correct get it into one filter and do the two checks. I wouldn't use Optional.ofNullable the Optional stuff is really for return types not to be doing logic... but really neither here nor there.

I wanted to point out that java.util.Objects has a nice method for this in a broad case, so you can do this:

cars.stream()
    .filter(Objects::nonNull)

Which will clear out your null objects. For anyone not familiar, that's the short-hand for the following:

cars.stream()
    .filter(car -> Objects.nonNull(car))

To partially answer the question at hand to return the list of car names that starts with "M":

cars.stream()
    .filter(car -> Objects.nonNull(car))
    .map(car -> car.getName())
    .filter(carName -> Objects.nonNull(carName))
    .filter(carName -> carName.startsWith("M"))
    .collect(Collectors.toList());

Once you get used to the shorthand lambdas you could also do this:

cars.stream()
    .filter(Objects::nonNull)
    .map(Car::getName)        // Assume the class name for car is Car
    .filter(Objects::nonNull)
    .filter(carName -> carName.startsWith("M"))
    .collect(Collectors.toList());

Unfortunately once you .map(Car::getName) you'll only be returning the list of names, not the cars. So less beautiful but fully answers the question:

cars.stream()
    .filter(car -> Objects.nonNull(car))
    .filter(car -> Objects.nonNull(car.getName()))
    .filter(car -> car.getName().startsWith("M"))
    .collect(Collectors.toList());

How to draw vectors (physical 2D/3D vectors) in MATLAB?

I agree with Aamir that the submission arrow.m from Erik Johnson on the MathWorks File Exchange is a very nice option. You can use it to illustrate the different methods of vector addition like so:

  • Tip-to-tail method:

    o = [0 0 0];  %# Origin
    a = [2 3 5];  %# Vector 1
    b = [1 1 0];  %# Vector 2
    c = a+b;      %# Resultant
    arrowStarts = [o; a; o];        %# Starting points for arrows
    arrowEnds = [a; c; c];          %# Ending points for arrows
    arrow(arrowStarts,arrowEnds);   %# Plot arrows
    
  • Parallelogram method:

    o = [0 0 0];  %# Origin
    a = [2 3 5];  %# Vector 1
    b = [1 1 0];  %# Vector 2
    c = a+b;      %# Resultant
    arrowStarts = [o; o; o];        %# Starting points for arrows
    arrowEnds = [a; b; c];          %# Ending points for arrows
    arrow(arrowStarts,arrowEnds);   %# Plot arrows
    hold on;
    lineX = [a(1) b(1); c(1) c(1)];  %# X data for lines
    lineY = [a(2) b(2); c(2) c(2)];  %# Y data for lines
    lineZ = [a(3) b(3); c(3) c(3)];  %# Z data for lines
    line(lineX,lineY,lineZ,'Color','k','LineStyle',':');  %# Plot lines
    

How to get twitter bootstrap modal to close (after initial launch)

Here is a snippet for not only closing modals without page refresh but when pressing enter it submits modal and closes without refresh

I have it set up on my site where I can have multiple modals and some modals process data on submit and some don't. What I do is create a unique ID for each modal that does processing. For example in my webpage:

HTML (modal footer):

 <div class="modal-footer form-footer"><br>
              <span class="caption">
                <button id="PreLoadOrders" class="btn btn-md green btn-right" type="button" disabled>Add to Cart&nbsp; <i class="fa fa-shopping-cart"></i></button>     
                <button id="ClrHist" class="btn btn-md red btn-right" data-dismiss="modal" data-original-title="" title="Return to Scan Order Entry" type="cancel">Cancel&nbsp; <i class="fa fa-close"></i></a>
              </span>
      </div>

jQUERY:

$(document).ready(function(){
// Allow enter key to trigger preloadorders form
    $(document).keypress(function(e) {       
      if(e.which == 13) {   
          e.preventDefault();   
                if($(".trigger").is(".ok")) 
                   $("#PreLoadOrders").trigger("click");
                else
                    return;
      }
    });
});

As you can see this submit performs processing which is why I have this jQuery for this modal. Now let's say I have another modal within this webpage but no processing is performed and since one modal is open at a time I put another $(document).ready() in a global php/js script that all pages get and I give the modal's close button a class called: ".modal-close":

HTML:

<div class="modal-footer caption">
                <button type="submit" class="modal-close btn default" data-dismiss="modal" aria-hidden="true">Close</button>
            </div>

jQuery (include global.inc):

  $(document).ready(function(){
         // Allow enter key to trigger a particular button anywhere on page
        $(document).keypress(function(e) {
                if(e.which == 13) {
                   if($(".modal").is(":visible")){   
                        $(".modal:visible").find(".modal-close").trigger('click');
                    }
                }
         });
    });

C++ IDE for Macs

Xcode which is part of the MacOS Developer Tools is a great IDE. There's also NetBeans and Eclipse that can be configured to build and compile C++ projects.

Clion from JetBrains, also is available now, and uses Cmake as project model.

How to handle query parameters in angular 2

Angular 5+ Update

The route.snapshot provides the initial value of the route parameter map. You can access the parameters directly without subscribing or adding observable operators. It's much simpler to write and read:

Quote from the Angular Docs

To break it down for you, here is how to do it with the new router:

this.router.navigate(['/login'], { queryParams: { token:'1234'} });

And then in the login component (notice the new .snapshot added):

constructor(private route: ActivatedRoute) {}
ngOnInit() {
    this.sessionId = this.route.snapshot.queryParams['token']

}

How to convert a string to number in TypeScript?

if you are talking about just types, as other people said, parseInt() etc will return the correct type. Also, if for any reason the value could be both a number or a string and you don't want to call parseInt(), typeof expressions will also cast to the correct type:

function f(value:number|string){
  if(typeof value==='number'){
   // value : number
  }else {
   // value : string
  }
}

How to generate a GUID in Oracle?

I would recommend using Oracle's "dbms_crypto.randombytes" function.

Why?
This function returns a RAW value containing a cryptographically secure pseudo-random sequence of bytes, which can be used to generate random material for encryption keys.

select REGEXP_REPLACE(dbms_crypto.randombytes(16), '(.{8})(.{4})(.{4})(.{4})(.{12})', '\1-\2-\3-\4-\5') from dual;

You should not use the function "sys_guid" because only one character changes.

ALTER TABLE locations ADD (uid_col RAW(16));

UPDATE locations SET uid_col = SYS_GUID();

SELECT location_id, uid_col FROM locations
   ORDER BY location_id, uid_col;

LOCATION_ID UID_COL
----------- ----------------------------------------------------------------
       1000 09F686761827CF8AE040578CB20B7491
       1100 09F686761828CF8AE040578CB20B7491
       1200 09F686761829CF8AE040578CB20B7491
       1300 09F68676182ACF8AE040578CB20B7491
       1400 09F68676182BCF8AE040578CB20B7491
       1500 09F68676182CCF8AE040578CB20B7491

https://docs.oracle.com/database/121/SQLRF/functions202.htm#SQLRF06120

ASP.NET strange compilation error

Cause: I have noticed that when I clean my project or clean one of the dependent projects and then hit refresh a few times on the page showing the site then it causes this error. It seems like it tries to load/run a broken/missing DLL project somehow.

Rename the project’s IIS directory to something different and with new name it loads fine (again providing project is built first OK then run otherwise it causes the same issue)

How to remove time portion of date in C# in DateTime object only?

Declare the variable as a string.

example :

public string dateOfBirth ;

then assign a value like :

dateOfBirth = ((DateTime)(datetimevaluefromDB)).ToShortDateString();

How to fix error Base table or view not found: 1146 Table laravel relationship table?

If you're facing this error but your issue is different and you're tired of searching for a long time then this might help you.

If you have changed your database and updated .env file and still facing same issue then you should check C:\xampp\htdocs{your-project-name}\bootstrap\cache\config.php file and replace or remove the old database name and other changed items.

True/False vs 0/1 in MySQL

If you are into performance, then it is worth using ENUM type. It will probably be faster on big tables, due to the better index performance.

The way of using it (source: http://dev.mysql.com/doc/refman/5.5/en/enum.html):

CREATE TABLE shirts (
    name VARCHAR(40),
    size ENUM('x-small', 'small', 'medium', 'large', 'x-large')
);

But, I always say that explaining the query like this:

EXPLAIN SELECT * FROM shirts WHERE size='medium';

will tell you lots of information about your query and help on building a better table structure. For this end, it is usefull to let phpmyadmin Propose a table table structure - but this is more a long time optimisation possibility, when the table is already filled with lots of data.

VBA code to set date format for a specific column as "yyyy-mm-dd"

Use the range's NumberFormat property to force the format of the range like this:

Sheet1.Range("A2", "A50000").NumberFormat = "yyyy-mm-dd"

How can I convert a DateTime to an int?

long n = long.Parse(date.ToString("yyyyMMddHHmmss"));

see Custom Date and Time Format Strings

How to show all privileges from a user in oracle?

There are various scripts floating around that will do that depending on how crazy you want to get. I would personally use Pete Finnigan's find_all_privs script.

If you want to write it yourself, the query gets rather challenging. Users can be granted system privileges which are visible in DBA_SYS_PRIVS. They can be granted object privileges which are visible in DBA_TAB_PRIVS. And they can be granted roles which are visible in DBA_ROLE_PRIVS (roles can be default or non-default and can require a password as well, so just because a user has been granted a role doesn't mean that the user can necessarily use the privileges he acquired through the role by default). But those roles can, in turn, be granted system privileges, object privileges, and additional roles which can be viewed by looking at ROLE_SYS_PRIVS, ROLE_TAB_PRIVS, and ROLE_ROLE_PRIVS. Pete's script walks through those relationships to show all the privileges that end up flowing to a user.

Error - Android resource linking failed (AAPT2 27.0.3 Daemon #0)

  • Right click on the drawable folder and select "Show in Explorer".
  • Find the failing file in the opened file system, select them (or select the files in the entire drawable), then copy them to the drawable-v24 file (do not delete the drawable file and create it if there is no drawable-v24 file).
  • Then choose File -> Invalidate Caches / Restart and
  • restart Android Studio.

Repeat-until or equivalent loop in Python

REPEAT
    ...
UNTIL cond

Is equivalent to

while True:
    ...
    if cond:
        break

Differences in boolean operators: & vs && and | vs ||

&& ; || are logical operators.... short circuit

& ; | are boolean logical operators.... Non-short circuit

Moving to differences in execution on expressions. Bitwise operators evaluate both sides irrespective of the result of left hand side. But in the case of evaluating expressions with logical operators, the evaluation of the right hand expression is dependent on the left hand condition.

For Example:

int i = 25;
int j = 25;
if(i++ < 0 && j++ > 0)
    System.out.println("OK");
System.out.printf("i = %d ; j = %d",i,j);

This will print i=26 ; j=25, As the first condition is false the right hand condition is bypassed as the result is false anyways irrespective of the right hand side condition.(short circuit)

int i = 25;
int j = 25;
if(i++ < 0 & j++ > 0)
    System.out.println("OK");
System.out.printf("i = %d ; j = %d",i,j);

But, this will print i=26; j=26,

NUnit Unit tests not showing in Test Explorer with Test Adapter installed

Make sure your tests are properly marked with the Test attribute. If all of the tests are marked with only the Explicit attribute, the TestAdapter doesn't recognize the fixture.

Warning: mysqli_select_db() expects exactly 2 parameters, 1 given in C:\

mysqli_select_db() should have 2 parameters, the connection link and the database name -

mysqli_select_db($con, 'phpcadet') or die(mysqli_error($con));

Using mysqli_error in the die statement will tell you exactly what is wrong as opposed to a generic error message.

How to check a string for a special character?

You can use string.punctuation and any function like this

import string
invalidChars = set(string.punctuation.replace("_", ""))
if any(char in invalidChars for char in word):
    print "Invalid"
else:
    print "Valid"

With this line

invalidChars = set(string.punctuation.replace("_", ""))

we are preparing a list of punctuation characters which are not allowed. As you want _ to be allowed, we are removing _ from the list and preparing new set as invalidChars. Because lookups are faster in sets.

any function will return True if atleast one of the characters is in invalidChars.

Edit: As asked in the comments, this is the regular expression solution. Regular expression taken from https://stackoverflow.com/a/336220/1903116

word = "Welcome"
import re
print "Valid" if re.match("^[a-zA-Z0-9_]*$", word) else "Invalid"

Reliable way to convert a file to a byte[]

byte[] bytes = File.ReadAllBytes(filename) 

or ...

var bytes = File.ReadAllBytes(filename) 

How do I make CMake output into a 'bin' dir?

$ cat CMakeLists.txt
project (hello)
set(EXECUTABLE_OUTPUT_PATH "bin")
add_executable (hello hello.c)

Using pointer to char array, values in that array can be accessed?

When you want to access an element, you have to first dereference your pointer, and then index the element you want (which is also dereferncing). i.e. you need to do:

printf("\nvalue:%c", (*ptr)[0]); , which is the same as *((*ptr)+0)

Note that working with pointer to arrays are not very common in C. instead, one just use a pointer to the first element in an array, and either deal with the length as a separate element, or place a senitel value at the end of the array, so one can learn when the array ends, e.g.

char arr[5] = {'a','b','c','d','e',0}; 
char *ptr = arr; //same as char *ptr = &arr[0]

printf("\nvalue:%c", ptr[0]);

Delete multiple objects in django

You can delete any QuerySet you'd like. For example, to delete all blog posts with some Post model

Post.objects.all().delete()

and to delete any Post with a future publication date

Post.objects.filter(pub_date__gt=datetime.now()).delete()

You do, however, need to come up with a way to narrow down your QuerySet. If you just want a view to delete a particular object, look into the delete generic view.

EDIT:

Sorry for the misunderstanding. I think the answer is somewhere between. To implement your own, combine ModelForms and generic views. Otherwise, look into 3rd party apps that provide similar functionality. In a related question, the recommendation was django-filter.

How to extract numbers from string in c?

Or you can make a simple function like this:

// Provided 'c' is only a numeric character
int parseInt (char c) {
    return c - '0';
}

In Typescript, what is the ! (exclamation mark / bang) operator when dereferencing a member?

That's the non-null assertion operator. It is a way to tell the compiler "this expression cannot be null or undefined here, so don't complain about the possibility of it being null or undefined." Sometimes the type checker is unable to make that determination itself.

It is explained here:

A new ! post-fix expression operator may be used to assert that its operand is non-null and non-undefined in contexts where the type checker is unable to conclude that fact. Specifically, the operation x! produces a value of the type of x with null and undefined excluded. Similar to type assertions of the forms <T>x and x as T, the ! non-null assertion operator is simply removed in the emitted JavaScript code.

I find the use of the term "assert" a bit misleading in that explanation. It is "assert" in the sense that the developer is asserting it, not in the sense that a test is going to be performed. The last line indeed indicates that it results in no JavaScript code being emitted.

Writing outputs to log file and console

exec 3>&1 1>>${LOG_FILE} 2>&1

would send stdout and stderr output into the log file, but would also leave you with fd 3 connected to the console, so you can do

echo "Some console message" 1>&3

to write a message just to the console, or

echo "Some console and log file message" | tee /dev/fd/3

to write a message to both the console and the log file - tee sends its output to both its own fd 1 (which here is the LOG_FILE) and the file you told it to write to (which here is fd 3, i.e. the console).

Example:

exec 3>&1 1>>${LOG_FILE} 2>&1

echo "This is stdout"
echo "This is stderr" 1>&2
echo "This is the console (fd 3)" 1>&3
echo "This is both the log and the console" | tee /dev/fd/3

would print

This is the console (fd 3)
This is both the log and the console

on the console and put

This is stdout
This is stderr
This is both the log and the console

into the log file.

Peak detection in a 2D array

It's probably worth to try with neural networks if you are able to create some training data... but this needs many samples annotated by hand.

GenyMotion Unable to start the Genymotion virtual device

In my case, the only option was to remove the VM and download it again. No re-configuration of the host-only adapter did not help, I used different addressing of DHCP. Virtual Box I updated to version 4.3.4 and Genymotion to 2.0.2

IIS7 deployment - duplicate 'system.web.extensions/scripting/scriptResourceHandler' section

This error message seems to come up in various situations.

In my case, on top of my application's Web.Config file I had an extra Web.Config file in the root folder (C:\Inetpub\www.root). Probably left there after some testing, I had forgotten all about it, and couldn't figure out what the problem was.

Removing it solved the problem for me.

How to Run the Procedure?

In SQL Plus:

VAR rc REFCURSOR
EXEC gokul_proc(1,'GOKUL', :rc);
print rc

How to change the background colour's opacity in CSS

Use RGBA like this: background-color: rgba(255, 0, 0, .5)

How to run Ruby code from terminal?

If Ruby is installed, then

ruby yourfile.rb

where yourfile.rb is the file containing the ruby code.

Or

irb

to start the interactive Ruby environment, where you can type lines of code and see the results immediately.

Automating the InvokeRequired code pattern

Create a ThreadSafeInvoke.snippet file, and then you can just select the update statements, right click and select 'Surround With...' or Ctrl-K+S:

<?xml version="1.0" encoding="utf-8" ?>
<CodeSnippet Format="1.0.0" xmlns="http://schemas.microsoft.com/VisualStudio/2005/CodeSnippet">
  <Header>
    <Title>ThreadsafeInvoke</Title>
    <Shortcut></Shortcut>
    <Description>Wraps code in an anonymous method passed to Invoke for Thread safety.</Description>
    <SnippetTypes>
      <SnippetType>SurroundsWith</SnippetType>
    </SnippetTypes>
  </Header>
  <Snippet>
    <Code Language="CSharp">
      <![CDATA[
      Invoke( (MethodInvoker) delegate
      {
          $selected$
      });      
      ]]>
    </Code>
  </Snippet>
</CodeSnippet>

How to print binary tree diagram?

This is a very simple solution to print out a tree. It is not that pretty, but it is really simple:

enum { kWidth = 6 };
void PrintSpace(int n)
{
  for (int i = 0; i < n; ++i)
    printf(" ");
}

void PrintTree(struct Node * root, int level)
{
  if (!root) return;
  PrintTree(root->right, level + 1);
  PrintSpace(level * kWidth);
  printf("%d", root->data);
  PrintTree(root->left, level + 1);
}

Sample output:

      106
            105
104
            103
                  102
                        101
      100

Jquery: Checking to see if div contains text, then action

Yes, I now made think for me. And it works fine!!!

if($("div:contains('CONGRATULATIONS')").length)
                        {
                            $('#SignupForm').hide(500);
                        }

Print all but the first three columns

Use cut:

cut -d <The character between characters> -f <number of first column>,<number of last column> <file name>

e.g.: If you have file1 containing : car.is.nice.equal.bmw

Run : cut -d . -f1,3 file1 will print car.is.nice

How to list all AWS S3 objects in a bucket using Java

As a slightly more concise solution to listing S3 objects when they might be truncated:

ListObjectsRequest request = new ListObjectsRequest().withBucketName(bucketName);
ObjectListing listing = null;

while((listing == null) || (request.getMarker() != null)) {
  listing = s3Client.listObjects(request);
  // do stuff with listing
  request.setMarker(listing.getNextMarker());
}

Can I serve multiple clients using just Flask app.run() as standalone?

Using the simple app.run() from within Flask creates a single synchronous server on a single thread capable of serving only one client at a time. It is intended for use in controlled environments with low demand (i.e. development, debugging) for exactly this reason.

Spawning threads and managing them yourself is probably not going to get you very far either, because of the Python GIL.

That said, you do still have some good options. Gunicorn is a solid, easy-to-use WSGI server that will let you spawn multiple workers (separate processes, so no GIL worries), and even comes with asynchronous workers that will speed up your app (and make it more secure) with little to no work on your part (especially with Flask).

Still, even Gunicorn should probably not be directly publicly exposed. In production, it should be used behind a more robust HTTP server; nginx tends to go well with Gunicorn and Flask.

Finding the max value of an attribute in an array of objects

Each array and get max value with Math.

data.reduce((max, b) => Math.max(max, b.costo), data[0].costo);

In Python, how do I determine if an object is iterable?

try:
  #treat object as iterable
except TypeError, e:
  #object is not actually iterable

Don't run checks to see if your duck really is a duck to see if it is iterable or not, treat it as if it was and complain if it wasn't.

Python 2: AttributeError: 'list' object has no attribute 'strip'

Split the strings and then use chain.from_iterable to combine them into a single list

>>> import itertools
>>> l = ['Facebook;Google+;MySpace', 'Apple;Android']
>>> l1 = [ x for x in itertools.chain.from_iterable( x.split(';') for x in l ) ]
>>> l1
['Facebook', 'Google+', 'MySpace', 'Apple', 'Android']

php - How do I fix this illegal offset type error

check $xml->entry[$i] exists and is an object before trying to get a property of it

 if(isset($xml->entry[$i]) && is_object($xml->entry[$i])){
   $source = $xml->entry[$i]->source;          
   $s[$source] += 1;
 }

or $source might not be a legal array offset but an array, object, resource or possibly null

blur() vs. onblur()

I guess it's just because the onblur event is called as a result of the input losing focus, there isn't a blur action associated with an input, like there is a click action associated with a button

How to get the parent dir location

Here is another relatively simple solution that:

  • does not use dirname() (which does not work as expected on one level arguments like "file.txt" or relative parents like "..")
  • does not use abspath() (avoiding any assumptions about the current working directory) but instead preserves the relative character of paths

it just uses normpath and join:

def parent(p):
    return os.path.normpath(os.path.join(p, os.path.pardir))

# Example:
for p in ['foo', 'foo/bar/baz', 'with/trailing/slash/', 
        'dir/file.txt', '../up/', '/abs/path']:
    print parent(p)

Result:

.
foo/bar
with/trailing
dir
..
/abs

Is there a pure CSS way to make an input transparent?

input[type="text"]
{
    background: transparent;
    border: none;
}

Nobody will even know it's there.

An ASP.NET setting has been detected that does not apply in Integrated managed pipeline mode

It took me few hours to solved this because all off the settings that I found here about this error were the same but it still didn't work. The problem was tha I had a folder in my web service from which the file should be send to WinCE device, after converting that folder to an application with Classic.NetAppPool it started to work.

jQuery equivalent of JavaScript's addEventListener method

_x000D_
_x000D_
$( "button" ).on( "click", function(event) {_x000D_
_x000D_
    alert( $( this ).html() );_x000D_
    console.log( event.target );_x000D_
_x000D_
} );
_x000D_
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.4.1/jquery.min.js"></script>_x000D_
_x000D_
<button>test 1</button>_x000D_
<button>test 2</button>
_x000D_
_x000D_
_x000D_

Order a MySQL table by two columns

ORDER BY article_rating, article_time DESC

will sort by article_time only if there are two articles with the same rating. From all I can see in your example, this is exactly what happens.

? primary sort                         secondary sort ?
1.  50 | This article rocks          | Feb 4, 2009    3.
2.  35 | This article is pretty good | Feb 1, 2009    2.
3.  5  | This Article isn't so hot   | Jan 25, 2009   1.

but consider:

? primary sort                         secondary sort ?
1.  50 | This article rocks          | Feb 2, 2009    3.
1.  50 | This article rocks, too     | Feb 4, 2009    4.
2.  35 | This article is pretty good | Feb 1, 2009    2.
3.  5  | This Article isn't so hot   | Jan 25, 2009   1.

How do I make a comment in a Dockerfile?

Use the # syntax for comments

From: https://docs.docker.com/engine/reference/builder/#format

# My comment here
RUN echo 'we are running some cool things'

MS SQL Date Only Without Time

FWIW, I've been doing the same thing as you for years

CAST(CONVERT(VARCHAR, [tstamp], 102) AS DATETIME) = @dateParam 

Seems to me like this is one of the better ways to strip off time in terms of flexibility, speed and readabily. (sorry). Some UDF functions as suggested can be useful, but UDFs can be slow with larger result sets.

Download file from an ASP.NET Web API method using AngularJS

C# WebApi PDF download all working with Angular JS Authentication

Web Api Controller

[HttpGet]
    [Authorize]
    [Route("OpenFile/{QRFileId}")]
    public HttpResponseMessage OpenFile(int QRFileId)
    {
        QRFileRepository _repo = new QRFileRepository();
        var QRFile = _repo.GetQRFileById(QRFileId);
        if (QRFile == null)
            return new HttpResponseMessage(HttpStatusCode.BadRequest);
        string path = ConfigurationManager.AppSettings["QRFolder"] + + QRFile.QRId + @"\" + QRFile.FileName;
        if (!File.Exists(path))
            return new HttpResponseMessage(HttpStatusCode.BadRequest);

        HttpResponseMessage response = new HttpResponseMessage(HttpStatusCode.OK);
        //response.Content = new StreamContent(new FileStream(localFilePath, FileMode.Open, FileAccess.Read));
        Byte[] bytes = File.ReadAllBytes(path);
        //String file = Convert.ToBase64String(bytes);
        response.Content = new ByteArrayContent(bytes);
        response.Content.Headers.ContentDisposition = new ContentDispositionHeaderValue("attachment");
        response.Content.Headers.ContentType = new MediaTypeHeaderValue("application/pdf");
        response.Content.Headers.ContentDisposition.FileName = QRFile.FileName;

        return response;
    }

Angular JS Service

this.getPDF = function (apiUrl) {
            var headers = {};
            headers.Authorization = 'Bearer ' + sessionStorage.tokenKey;
            var deferred = $q.defer();
            $http.get(
                hostApiUrl + apiUrl,
                {
                    responseType: 'arraybuffer',
                    headers: headers
                })
            .success(function (result, status, headers) {
                deferred.resolve(result);;
            })
             .error(function (data, status) {
                 console.log("Request failed with status: " + status);
             });
            return deferred.promise;
        }

        this.getPDF2 = function (apiUrl) {
            var promise = $http({
                method: 'GET',
                url: hostApiUrl + apiUrl,
                headers: { 'Authorization': 'Bearer ' + sessionStorage.tokenKey },
                responseType: 'arraybuffer'
            });
            promise.success(function (data) {
                return data;
            }).error(function (data, status) {
                console.log("Request failed with status: " + status);
            });
            return promise;
        }

Either one will do

Angular JS Controller calling the service

vm.open3 = function () {
        var downloadedData = crudService.getPDF('ClientQRDetails/openfile/29');
        downloadedData.then(function (result) {
            var file = new Blob([result], { type: 'application/pdf;base64' });
            var fileURL = window.URL.createObjectURL(file);
            var seconds = new Date().getTime() / 1000;
            var fileName = "cert" + parseInt(seconds) + ".pdf";
            var a = document.createElement("a");
            document.body.appendChild(a);
            a.style = "display: none";
            a.href = fileURL;
            a.download = fileName;
            a.click();
        });
    };

And last the HTML page

<a class="btn btn-primary" ng-click="vm.open3()">FILE Http with crud service (3 getPDF)</a>

This will be refactored just sharing the code now hope it helps someone as it took me a while to get this working.

Who sets response content-type in Spring MVC (@ResponseBody)

I set the content-type in the MarshallingView in the ContentNegotiatingViewResolver bean. It works easily, clean and smoothly:

<property name="defaultViews">
  <list>
    <bean class="org.springframework.web.servlet.view.xml.MarshallingView">
      <constructor-arg>
        <bean class="org.springframework.oxm.xstream.XStreamMarshaller" />     
      </constructor-arg>
      <property name="contentType" value="application/xml;charset=UTF-8" />
    </bean>
  </list>
</property>

SQLSTATE[42S22]: Column not found: 1054 Unknown column 'id' in 'where clause' (SQL: select * from `songs` where `id` = 5 limit 1)

$song = DB::table('songs')->find($id);

here you use method find($id)

for Laravel, if you use this method, you should have column named 'id' and set it as primary key, so then you'll be able to use method find()

otherwise use where('SongID', $id) instead of find($id)

Getting Unexpected Token Export

Using ES6 syntax does not work in node, unfortunately, you have to have babel apparently to make the compiler understand syntax such as export or import.

npm install babel-cli --save

Now we need to create a .babelrc file, in the babelrc file, we’ll set babel to use the es2015 preset we installed as its preset when compiling to ES5.

At the root of our app, we’ll create a .babelrc file. $ npm install babel-preset-es2015 --save

At the root of our app, we’ll create a .babelrc file.

{  "presets": ["es2015"] }

Hope it works ... :)

JavaScript split String with white space

Although this is not supported by all browsers, if you use capturing parentheses inside your regular expression then the captured input is spliced into the result.

If separator is a regular expression that contains capturing parentheses, then each time separator is matched, the results (including any undefined results) of the capturing parentheses are spliced into the output array. [reference)

So:

var stringArray = str.split(/(\s+)/);
                             ^   ^
//

Output:

["my", " ", "car", " ", "is", " ", "red"]

This collapses consecutive spaces in the original input, but otherwise I can't think of any pitfalls.

How to scroll to top of long ScrollView layout?

I faced Same Problem When i am using Scrollview inside View Flipper or Dialog that case scrollViewObject.fullScroll(ScrollView.FOCUS_UP) returns false so that case scrollViewObject.smoothScrollTo(0, 0) is Worked for me

Scroll Focus Top

How to reference a .css file on a razor view?

I prefer to use the razor html helper from Client Dependency dll

Html.RequireCss("yourfile", 9999); // 9999 is loading priority 

Add missing dates to pandas dataframe

You could use Series.reindex:

import pandas as pd

idx = pd.date_range('09-01-2013', '09-30-2013')

s = pd.Series({'09-02-2013': 2,
               '09-03-2013': 10,
               '09-06-2013': 5,
               '09-07-2013': 1})
s.index = pd.DatetimeIndex(s.index)

s = s.reindex(idx, fill_value=0)
print(s)

yields

2013-09-01     0
2013-09-02     2
2013-09-03    10
2013-09-04     0
2013-09-05     0
2013-09-06     5
2013-09-07     1
2013-09-08     0
...

Cannot find vcvarsall.bat when running a Python script

The solution to this problem is to set the following environment variable:

VS90COMNTOOLS

For instance:

set VS90COMNTOOLS=C:\Program Files\Microsoft Visual Studio 9.0\Common7\Tools

This error can be caused by not rebooting after installing Visual Studios, or not starting a new command prompt after installing.

Also the version of Visual Studios you can use to compile the extensions may depend on the version of python you are building for.

The role of #ifdef and #ifndef

"#if one" means that if "#define one" has been written "#if one" is executed otherwise "#ifndef one" is executed.

This is just the C Pre-Processor (CPP) Directive equivalent of the if, then, else branch statements in the C language.

i.e. if {#define one} then printf("one evaluates to a truth "); else printf("one is not defined "); so if there was no #define one statement then the else branch of the statement would be executed.

Get current directory name (without full path) in a Bash script

basename $(pwd)

or

echo "$(basename $(pwd))"

How to trigger an event in input text after I stop typing/writing?

There is some simple plugin I've made that does exacly that. It requires much less code than proposed solutions and it's very light (~0,6kb)

First you create Bid object than can be bumped anytime. Every bump will delay firing Bid callback for next given ammount of time.

var searchBid = new Bid(function(inputValue){
    //your action when user will stop writing for 200ms. 
    yourSpecialAction(inputValue);
}, 200); //we set delay time of every bump to 200ms

When Bid object is ready, we need to bump it somehow. Let's attach bumping to keyup event.

$("input").keyup(function(){
    searchBid.bump( $(this).val() ); //parameters passed to bump will be accessable in Bid callback
});

What happens here is:

Everytime user presses key, bid is 'delayed' (bumped) for next 200ms. If 200ms will pass without beeing 'bumped' again, callback will be fired.

Also, you've got 2 additional functions for stopping bid (if user pressed esc or clicked outside input for example) and for finishing and firing callback immediately (for example when user press enter key):

searchBid.stop();
searchBid.finish(valueToPass);

How to handle screen orientation change when progress dialog and background thread active?

These days there is a much more distinct way to handle these types of issues. The typical approach is:

1. Ensure your data is properly seperated from the UI:

Anything that is a background process should be in a retained Fragment (set this with Fragment.setRetainInstance(). This becomes your 'persistent data storage' where anything data based that you would like retained is kept. After the orientation change event, this Fragment will still be accessible in its original state through a FragmentManager.findFragmentByTag() call (when you create it you should give it a tag not an ID as it is not attached to a View).

See the Handling Runtime Changes developed guide for information about doing this correctly and why it is the best option.

2. Ensure you are interfacing correctly and safely between the background processs and your UI:

You must reverse your linking process. At the moment your background process attaches itself to a View - instead your View should be attaching itself to the background process. It makes more sense right? The View's action is dependent on the background process, whereas the background process is not dependent on the View.This means changing the link to a standard Listener interface. Say your process (whatever class it is - whether it is an AsyncTask, Runnable or whatever) defines a OnProcessFinishedListener, when the process is done it should call that listener if it exists.

This answer is a nice concise description of how to do custom listeners.

3. Link your UI into the data process whenever the UI is created (including orientation changes):

Now you must worry about interfacing the background task with whatever your current View structure is. If you are handling your orientation changes properly (not the configChanges hack people always recommend), then your Dialog will be recreated by the system. This is important, it means that on the orientation change, all your Dialog's lifecycle methods are recalled. So in any of these methods (onCreateDialog is usually a good place), you could do a call like the following:

DataFragment f = getActivity().getFragmentManager().findFragmentByTag("BACKGROUND_TAG");
if (f != null) {
    f.mBackgroundProcess.setOnProcessFinishedListener(new OnProcessFinishedListener() {
        public void onProcessFinished() {
            dismiss();
        }
    });
 }

See the Fragment lifecycle for deciding where setting the listener best fits in your individual implementation.

This is a general approach to providing a robust and complete solution to the generic problem asked in this question. There is probably a few minor pieces missing in this answer depending on your individual scenario, but this is generally the most correct approach for properly handling orientation change events.

How to add onload event to a div element

Try this.

_x000D_
_x000D_
document.getElementById("div").onload = alert("This is a div.");
_x000D_
<div id="div">Hello World</div>
_x000D_
_x000D_
_x000D_

Try this one too. You need to remove . from oQuickReply.swap() to make the function working.

_x000D_
_x000D_
document.getElementById("div").onload = oQuickReplyswap();_x000D_
function oQuickReplyswap() {_x000D_
alert("Hello World");_x000D_
}
_x000D_
<div id="div"></div>
_x000D_
_x000D_
_x000D_

Set selected item in Android BottomNavigationView

Add android:enabled="true" to BottomNavigationMenu Items.

And then set bottomNavigationView.setOnNavigationItemSelectedListener(mListener) and set it as selected by doing bottomNavigationView.selectedItemId = R.id.your_menu_id

Windows batch script launch program and exit console

The simplest way ist just to start it with start

start notepad.exe

Here you can find more information about start

How can I simulate an array variable in MySQL?

Maybe create a temporary memory table with columns (key, value) if you want associative arrays. Having a memory table is the closest thing to having arrays in mysql

How do you do a ‘Pause’ with PowerShell 2.0?

cmd /c pause | out-null

(It is not the PowerShell way, but it's so much more elegant.)

Save trees. Use one-liners.

Searching for Text within Oracle Stored Procedures

If you use UPPER(text), the like '%lah%' will always return zero results. Use '%LAH%'.

Get SSID when WIFI is connected

Answer In Kotlin Give Permissions

<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
<uses-permission android:name="android.permission.ACCESS_WIFI_STATE" />
<uses-permission android:name="android.permission.CHANGE_WIFI_STATE" />
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />



 private fun getCurrentNetworkDetail() {
    val connManager =
        context.getSystemService(Context.CONNECTIVITY_SERVICE) as ConnectivityManager
    val networkInfo = connManager.getNetworkInfo(ConnectivityManager.TYPE_WIFI)
    if (networkInfo.isConnected) {
        val wifiManager =
            context.getApplicationContext().getSystemService(Context.WIFI_SERVICE) as WifiManager
        val connectionInfo = wifiManager.connectionInfo
        if (connectionInfo != null && !TextUtils.isEmpty(connectionInfo.ssid)) {
            Log.e("ssid", connectionInfo.ssid)
        }
    }
    else{
        Log.e("ssid", "No Connection")
    }

}

'NoneType' object is not subscriptable?

Don't use list as a variable name for it shadows the builtin.

And there is no need to determine the length of the list. Just iterate over it.

def printer(data):
    for element in data:
        print(element[0])

Just an addendum: Looking at the contents of the inner lists I think they might be the wrong data structure. It looks like you want to use a dictionary instead.

Using @property versus getters and setters

In Python you don't use getters or setters or properties just for the fun of it. You first just use attributes and then later, only if needed, eventually migrate to a property without having to change the code using your classes.

There is indeed a lot of code with extension .py that uses getters and setters and inheritance and pointless classes everywhere where e.g. a simple tuple would do, but it's code from people writing in C++ or Java using Python.

That's not Python code.

Scale image to fit a bounding box

This example to stretch the image proportionally to fit the entire window. An improvisation to the above correct code is to add $( window ).resize(function(){});

function stretchImg(){
    $('div').each(function() {
      ($(this).height() > $(this).find('img').height()) 
        ? $(this).find('img').removeClass('fillwidth').addClass('fillheight')
        : '';
      ($(this).width() > $(this).find('img').width()) 
        ? $(this).find('img').removeClass('fillheight').addClass('fillwidth')
        : '';
    });
}
stretchImg();

$( window ).resize(function() {
    strechImg();
});

There are two if conditions. The first one keeps checking if the image height is less than the div and applies .fillheight class while the next checks for width and applies .fillwidth class. In both cases the other class is removed using .removeClass()

Here is the CSS

.fillwidth { 
   width: 100%;
   max-width: none;
   height: auto; 
}
.fillheight { 
   height: 100vh;
   max-width: none;
   width: auto; 
}

You can replace 100vh by 100% if you want to stretch the image with in a div. This example to stretch the image proportionally to fit the entire window.

LISTAGG function: "result of string concatenation is too long"

Short of using 12c overflow using the CLOB and substr will also work

rtrim(dbms_lob.substr(XMLAGG(XMLELEMENT(E,column_name,',').EXTRACT('//text()') ORDER BY column_name).GetClobVal(),1000,1),',')

Write variable to file, including name

I found an easy way to get the dictionary value, and its name as well! I'm not sure yet about reading it back, I'm going to continue to do research and see if I can figure that out.

Here is the code:

your_dict = {'one': 1, 'two': 2}

variables = [var for var in dir() if var[0:2] != "__" and var[-1:-2] != "__"]

file = open("your_file","w")
for var in variables:
     if isinstance(locals()[var], dict):
          file.write(str(var) + " = " + str(locals()[var]) + "\n")
file.close()

Only problem here is this will output every dictionary in your namespace to the file, maybe you can sort them out by values? locals()[var] == your_dict for reference.

You can also remove if isinstance(locals()[var], dict): to output EVERY variable in your namespace, regardless of type. Your output looks exactly like your decleration your_dict = {'one': 1, 'two': 2}.

Hopefully this gets you one step closer! I'll make an edit if I can figure out how to read them back into the namespace :)

---EDIT---

Got it! I've added a few variables (and variable types) for proof of concept. Here is what my "testfile.txt" looks like:

string_test = Hello World
integer_test = 42
your_dict = {'one': 1, 'two': 2}

And here is the code the processes it:

import ast

file = open("testfile.txt", "r")
data = file.readlines()
file.close()

for line in data:
    var_name, var_val = line.split(" = ")
    for possible_num_types in range(3):  # Range is the == number of types we will try casting to
        try:
            var_val = int(var_val)
            break
        except (TypeError, ValueError):
            try:
                var_val = ast.literal_eval(var_val)
                break
            except (TypeError, ValueError, SyntaxError):
                var_val = str(var_val).replace("\n","")
                break
    locals()[var_name] = var_val


print("string_test =", string_test, " :  Type =", type(string_test))
print("integer_test =", integer_test, " :  Type =", type(integer_test))
print("your_dict =", your_dict, " :  Type =", type(your_dict))

This is what that outputs:

string_test = Hello World  :  Type = <class 'str'>
integer_test = 42  :  Type = <class 'int'>
your_dict = {'two': 2, 'one': 1}  :  Type = <class 'dict'>

I really don't like how the casting here works, the try-except block is bulky and ugly. Even worse, you cannot accept just any type! You have to know what you are expecting to take in. This wouldn't be nearly as bad if you only cared about dictionaries, but I really wanted something a bit more universal.

If anybody knows how to better cast these input vars I would LOVE to hear about it!

Regardless, this should still get you there :D I hope I've helped out!

How to prevent "The play() request was interrupted by a call to pause()" error?

This piece of code fixed for me!

Modified code of @JohnnyCoder

HTML:

 <video id="captureVideoId" muted width="1280" height="768"></video>
                <video controls id="recordedVideoId" muted width="1280" 
 style="display:none;" height="768"></video>

JS:

  var recordedVideo = document.querySelector('video#recordedVideoId');
  var superBuffer = new Blob(recordedBlobs, { type: 'video/webm' });
  recordedVideo.src = window.URL.createObjectURL(superBuffer);
  // workaround for non-seekable video taken from
  // https://bugs.chromium.org/p/chromium/issues/detail?id=642012#c23
  recordedVideo.addEventListener('loadedmetadata', function () {
    if (recordedVideo.duration === Infinity) {
        recordedVideo.currentTime = 1e101;
        recordedVideo.ontimeupdate = function () {
            recordedVideo.currentTime = 0;
            recordedVideo.ontimeupdate = function () {
                delete recordedVideo.ontimeupdate;
                var isPlaying = recordedVideo.currentTime > 0 && 
     !recordedVideo.paused && !recordedVideo.ended && 
      recordedVideo.readyState > 2;
                if (isPlaying) {
                    recordedVideo.play();
                }
            };
        };
       }
      });

Cannot find module cv2 when using OpenCV

I have come accross same as this problem i installed cv2 by

pip install cv2

However when i import cv2 module it displayed no module named cv2 error.
Then i searched and find cv2.pyd files in my computer and i copy and paste to site-packages directory

C:\Python27\Lib\site-packages

then i closed and reopened existing application, it worked.

EDIT I will tell how to install cv2 correctly.

1. Firstly install numpy on your computer by

pip install numpy


2. Download opencv from internet (almost 266 mb).
I download opencv-2.4.12.exe for python 2.7. Then install this opencv-2.4.12.exe file.
I extracted to C:\Users\harun\Downloads to this folder.
After installation go look for cv2.py into the folders.
For me

C:\Users\harun\Downloads\opencv\build\python\2.7\x64

in this folder take thecv2.pyd and copy it in to the

C:\Python27\Lib\site-packages

now you can able to use cv2 in you python scripts.

How can I join on a stored procedure?

Here's a terrible idea for you.

Use an alias, create a new linked server from your server to its own alias.

Now you can do:

select a.SomeColumns, b.OtherColumns
from LocalDb.dbo.LocalTable a
inner join (select * from openquery([AliasToThisServer],'
exec LocalDb.dbo.LocalStoredProcedure
') ) b
on a.Id = b.Id

How to simulate a mouse click using JavaScript?

From the Mozilla Developer Network (MDN) documentation, HTMLElement.click() is what you're looking for. You can find out more events here.

Why is `input` in Python 3 throwing NameError: name... is not defined

If we setaside the syntax error of print, then the way to use input in multiple scenarios are -

If using python 2.x :

then for evaluated input use "input"
example: number = input("enter a number")

and for string use "raw_input"
example: name = raw_input("enter your name")

If using python 3.x :

then for evaluated result use "eval" and "input"
example: number = eval(input("enter a number"))

for string use "input"
example: name = input("enter your name")

What is a Data Transfer Object (DTO)?

In general Value Objects should be Immutable. Like Integer or String objects in Java. We can use them for transferring data between software layers. If the software layers or services running in different remote nodes like in a microservices environment or in a legacy Java Enterprise App. We must make almost exact copies of two classes. This is the where we met DTOs.

|-----------|                                                   |--------------|
| SERVICE 1 |--> Credentials DTO >--------> Credentials DTO >-- | AUTH SERVICE |
|-----------|                                                   |--------------|

In legacy Java Enterprise Systems DTOs can have various EJB stuff in it.

I do not know this is a best practice or not but I personally use Value Objects in my Spring MVC/Boot Projects like this:

        |------------|         |------------------|                             |------------|
-> Form |            | -> Form |                  | -> Entity                   |            |
        | Controller |         | Service / Facade |                             | Repository |
<- View |            | <- View |                  | <- Entity / Projection View |            |
        |------------|         |------------------|                             |------------|

Controller layer doesn't know what are the entities are. It communicates with Form and View Value Objects. Form Objects has JSR 303 Validation annotations (for instance @NotNull) and View Value Objects have Jackson Annotations for custom serialization. (for instance @JsonIgnore)

Service layer communicates with repository layer via using Entity Objects. Entity objects have JPA/Hibernate/Spring Data annotations on it. Every layer communicates with only the lower layer. The inter-layer communication is prohibited because of circular/cyclic dependency.

User Service ----> XX CANNOT CALL XX ----> Order Service

Some ORM Frameworks have the ability of projection via using additional interfaces or classes. So repositories can return View objects directly. There for you do not need an additional transformation.

For instance this is our User entity:

@Entity
public final class User {
    private String id;
    private String firstname;
    private String lastname;
    private String phone;
    private String fax;
    private String address;
    // Accessors ...
}

But you should return a Paginated list of users that just include id, firstname, lastname. Then you can create a View Value Object for ORM projection.

public final class UserListItemView {
    private String id;
    private String firstname;
    private String lastname;
    // Accessors ...
}

You can easily get the paginated result from repository layer. Thanks to spring you can also use just interfaces for projections.

List<UserListItemView> find(Pageable pageable);

Don't worry for other conversion operations BeanUtils.copy method works just fine.

For loop in Objective-C

You mean fast enumeration? You question is very unclear.

A normal for loop would look a bit like this:

unsigned int i, cnt = [someArray count];
for(i = 0; i < cnt; i++)
{ 
   // do loop stuff
   id someObject = [someArray objectAtIndex:i];
}

And a loop with fast enumeration, which is optimized by the compiler, would look like this:

for(id someObject in someArray)
{
   // do stuff with object
}

Keep in mind that you cannot change the array you are using in fast enumeration, thus no deleting nor adding when using fast enumeration

Pass multiple parameters to rest API - Spring

Multiple parameters can be given like below,

    @RequestMapping(value = "/mno/{objectKey}", method = RequestMethod.GET, produces = "application/json")
    public List<String> getBook(HttpServletRequest httpServletRequest, @PathVariable(name = "objectKey") String objectKey
      , @RequestParam(value = "id", defaultValue = "false")String id,@RequestParam(value = "name", defaultValue = "false") String name) throws Exception {
               //logic
}

jquery get all input from specific form

_x000D_
_x000D_
$(document).on("submit","form",function(e){
        //e.preventDefault();
        $form = $(this);
        $i = 0;
        $("form input[required],form select[required]").each(function(){
            if ($(this).val().trim() == ''){
                $(this).css('border-color', 'red');
                $i++;
            }else{
                $(this).css('border-color', '');    
            }               
        })
        if($i != 0) e.preventDefault();
    });
    $(document).on("change","input[required]",function(e){
        if ($(this).val().trim() == '')
            $(this).css('border-color', 'red');
        else
            $(this).css('border-color', '');    
    });
    $(document).on("change","select[required]",function(e){
        if ($(this).val().trim() == '')
            $(this).css('border-color', 'red');
        else
            $(this).css('border-color', '');
    });
_x000D_
_x000D_
_x000D_

Saving an image in OpenCV

SayntLewis is right. When you activate the camera with cvCaptureFromCAM, the auto white balance is not yet adjusted (it's a slow process), so you may get a mostly white or mostly black (depends on the camera and your lightning conditions) on the first frames. The same happens when there's a sudden change of the lightning of the scene. Just wait some time after opening the camera, flush the buffer and you're ready to go.

CASE .. WHEN expression in Oracle SQL

Since web search for Oracle case tops to that link, I add here for case statement, though not answer to the question asked about case expression:

CASE
   WHEN grade = 'A' THEN dbms_output.put_line('Excellent');
   WHEN grade = 'B' THEN dbms_output.put_line('Very Good');
   WHEN grade = 'C' THEN dbms_output.put_line('Good');
   WHEN grade = 'D' THEN dbms_output.put_line('Fair');
   WHEN grade = 'F' THEN dbms_output.put_line('Poor');
   ELSE dbms_output.put_line('No such grade');
END CASE;

or other variant:

CASE grade
   WHEN 'A' THEN dbms_output.put_line('Excellent');
   WHEN 'B' THEN dbms_output.put_line('Very Good');
   WHEN 'C' THEN dbms_output.put_line('Good');
   WHEN 'D' THEN dbms_output.put_line('Fair');
   WHEN 'F' THEN dbms_output.put_line('Poor');
   ELSE dbms_output.put_line('No such grade');
END CASE;

Per Oracle docs: https://docs.oracle.com/cd/B10501_01/appdev.920/a96624/04_struc.htm

How can I clear console

// #define _WIN32_WINNT 0x0500     // windows >= 2000 
#include <windows.h> 
#include <iostream>

using namespace std; 

void pos(short C, short R)
{
    COORD xy ;
    xy.X = C ;
    xy.Y = R ;
    SetConsoleCursorPosition( 
    GetStdHandle(STD_OUTPUT_HANDLE), xy);
}
void cls( )
{
    pos(0,0);
    for(int j=0;j<100;j++)
    cout << string(100, ' ');
    pos(0,0);
} 

int main( void )
{
    // write somthing and wait 
    for(int j=0;j<100;j++)
    cout << string(10, 'a');
    cout << "\n\npress any key to cls... ";
    cin.get();

    // clean the screen
    cls();

    return 0;
}

Open page in new window without popup blocking

PS> I posted this answer on a related question. Here's how I got round the issue of my async ajax request losing the trusted context:

I opened the popup directly on the users click, directed the url to about:blank and got a handle on that window. You could probably direct the popup to a 'loading' url while your ajax request is made

var myWindow = window.open("about:blank",'name','height=500,width=550');

Then, when my request is successful, I open my callback url in the window

function showWindow(win, url) {
     win.open(url,'name','height=500,width=550');
}

Reducing video size with same format and reducing frame size

If you want to keep same screen size, you can consider using crf factor: https://trac.ffmpeg.org/wiki/Encode/H.264

Here is the command which works for me: (on mac you need to add -strict -2 to be able to use aac audio codec.

ffmpeg -i input.mp4 -c:v libx264 -crf 24 -b:v 1M -c:a aac output.mp4

Add image in pdf using jspdf

For result in base64, before convert to canvas:

var getBase64ImageUrl = function(url, callback, mine) {

                    var img = new Image();

                    url = url.replace("http://","//");

                    img.setAttribute('crossOrigin', 'anonymous');

                    img.onload = function () {
                        var canvas = document.createElement("canvas");
                        canvas.width =this.width;
                        canvas.height =this.height;

                        var ctx = canvas.getContext("2d");
                        ctx.drawImage(this, 0, 0);

                        var dataURL = canvas.toDataURL(mine || "image/jpeg");

                        callback(dataURL);
                    };
                    img.src = url;

                    img.onerror = function(){

                        console.log('on error')
                        callback('');

                    }

            }

   getBase64ImageUrl('Koala.jpeg', function(img){
         //img is a base64encode result
         //return img;
          console.log(img);

          var doc = new jsPDF();
              doc.setFontSize(40);
              doc.text(30, 20, 'Hello world!');
              doc.output('datauri');
              doc.addImage(img, 'JPEG', 15, 40, 180, 160);
    });

How to add display:inline-block in a jQuery show() function?

try this:

$('#foo').show(0).css('display','inline-block');

How to jump back to NERDTree from file in tab?

All The Shortcuts And Functionality is At

press CTRL-?

Getting Excel to refresh data on sheet from within VBA

You might also try

Application.CalculateFull

or

Application.CalculateFullRebuild

if you don't mind rebuilding all open workbooks, rather than just the active worksheet. (CalculateFullRebuild rebuilds dependencies as well.)

How to read fetch(PDO::FETCH_ASSOC);

/* Design Pattern "table-data gateway" */

class Gateway
{
    protected $connection = null;

    public function __construct()
    {
        $this->connection = new PDO("mysql:host=localhost; dbname=db_users", 'root', '');
    }

    public function loadAll()
    {
        $sql = 'SELECT * FROM users';
        $rows = $this->connection->query($sql);

        return $rows;
    }

    public function loadById($id)
    {
        $sql = 'SELECT * FROM users WHERE user_id = ' . (int) $id;
        $result = $this->connection->query($sql);

        return $result->fetch(PDO::FETCH_ASSOC);
        // http://php.net/manual/en/pdostatement.fetch.php //                   
    }
}

/* Print all row with column 'user_id' only */

$gateway  = new Gateway();
$users    = $gateway->loadAll();

$no = 1;
foreach ($users as $key => $value) {
    echo $no . '. ' . $key . ' => ' . $value['user_id'] . '<br />';
    $no++;
}

/* Print user_id = 1 with all column */

$user = $gateway->loadById(1);

$no = 1;
foreach ($user as $key => $value) {
    echo $no . '. ' . $key . ' => ' . $value . '<br />';
    $no++;
}

/* Print user_id = 1 with column 'email and password' */

$user = $gateway->loadById(1);

echo $user['email'];
echo $user['password'];

Inverse dictionary lookup in Python

There is none. Don't forget that the value may be found on any number of keys, including 0 or more than 1.

WPF ListView turn off selection

Below code disable Focus on ListViewItem

<ListView.ItemContainerStyle>
<Style TargetType="{x:Type ListViewItem}">
    <Setter Property="Background" Value="Transparent" />
    <Setter Property="Template">
        <Setter.Value>
            <ControlTemplate TargetType="{x:Type ListViewItem}">
                <ContentPresenter />
            </ControlTemplate>
        </Setter.Value>
    </Setter>
</Style>

Show Image View from file path?

String path = Environment.getExternalStorageDirectory()+ "/Images/test.jpg";

File imgFile = new File(path);
if(imgFile.exists())
{
   Bitmap myBitmap = BitmapFactory.decodeFile(imgFile.getAbsolutePath());
   ImageView imageView=(ImageView)findViewById(R.id.imageView);
  imageView.setImageBitmap(myBitmap);
}

Why doesn't Console.Writeline, Console.Write work in Visual Studio Express?

Right click on the project in solution-explorer and click "clean".

Now run F5

Make sure the code is as below:

Console.WriteLine("TEST");
Console.ReadLine();

How do you check if a certain index exists in a table?

Wrote the below function that allows me to quickly check to see if an index exists; works just like OBJECT_ID.

CREATE FUNCTION INDEX_OBJECT_ID (
    @tableName VARCHAR(128),
    @indexName VARCHAR(128)
    )
RETURNS INT
AS
BEGIN
    DECLARE @objectId INT

    SELECT @objectId = i.object_id
    FROM sys.indexes i
    WHERE i.object_id = OBJECT_ID(@tableName)
    AND i.name = @indexName

    RETURN @objectId
END
GO

EDIT: This just returns the OBJECT_ID of the table, but it will be NULL if the index doesn't exist. I suppose you could set this to return index_id, but that isn't super useful.

Set textarea width to 100% in bootstrap modal

I had the same problem. I fixed it by adding this piece of code inside the text area's style.

resize: vertical;

You can check the Bootstrap reference here

What are database constraints?

  1. UNIQUE constraint (of which a PRIMARY KEY constraint is a variant). Checks that all values of a given field are unique across the table. This is X-axis constraint (records)

  2. CHECK constraint (of which a NOT NULL constraint is a variant). Checks that a certain condition holds for the expression over the fields of the same record. This is Y-axis constraint (fields)

  3. FOREIGN KEY constraint. Checks that a field's value is found among the values of a field in another table. This is Z-axis constraint (tables).

What is the meaning of single and double underscore before an object name?

._variable is semiprivate and meant just for convention

.__variable is often incorrectly considered superprivate, while it's actual meaning is just to namemangle to prevent accidental access[1]

.__variable__ is typically reserved for builtin methods or variables

You can still access .__mangled variables if you desperately want to. The double underscores just namemangles, or renames, the variable to something like instance._className__mangled

Example:

class Test(object):
    def __init__(self):
        self.__a = 'a'
        self._b = 'b'

>>> t = Test()
>>> t._b
'b'

t._b is accessible because it is only hidden by convention

>>> t.__a
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
AttributeError: 'Test' object has no attribute '__a'

t.__a isn't found because it no longer exists due to namemangling

>>> t._Test__a
'a'

By accessing instance._className__variable instead of just the double underscore name, you can access the hidden value

Excel VBA Macro: User Defined Type Not Defined

Sub DeleteEmptyRows()  

    Worksheets("YourSheetName").Activate
    On Error Resume Next
    Columns("A").SpecialCells(xlCellTypeBlanks).EntireRow.Delete

End Sub

The following code will delete all rows on a sheet(YourSheetName) where the content of Column A is blank.

EDIT: User Defined Type Not Defined is caused by "oTable As Table" and "oRow As Row". Replace Table and Row with Object to resolve the error and make it compile.

How to pass variable as a parameter in Execute SQL Task SSIS?

Along with @PaulStock's answer, Depending on your connection type, your variable names and SQLStatement/SQLStatementSource Changes

https://docs.microsoft.com/en-us/sql/integration-services/control-flow/execute-sql-task https://docs.microsoft.com/en-us/sql/integration-services/control-flow/execute-sql-task

How to copy directories with spaces in the name

There is a bug in robocopy in interpreting the source name. If you include a back slash at the end of the path to describe a folder it keeps including the string for the source into the rest of the line. ie

robocopy "C:\back up\" %destination% /e Nothing here will go to the destination string

robocopy "C:\back up" %destination% /e but this works

I may be wrong but I think both should work!

From Arraylist to Array

ArrayList<String> myArrayList = new ArrayList<String>();
...
String[] myArray = myArrayList.toArray(new String[0]);

Whether it's a "good idea" would really be dependent on your use case.

box-shadow on bootstrap 3 container

For those wanting the box-shadow on the col-* container itself and not on the .container, you can add another div just inside the col-* element, and add the shadow to that. This element will not have the padding, and therefor not interfere.

The first image has the box-shadow on the col-* element. Because of the 15px padding on the col element, the shadow is pushed to the outside of the div element rather than on the visual edges of it.

box-shadow on col-* element

<div class="col-md-4" style="box-shadow: 0px 2px 25px rgba(0, 0, 0, .25);">
    <div class="thumbnail">
        {!! HTML::image('images/sampleImage.png') !!}
    </div>
</div>

The second image has a wrapper div with the box-shadow on it. This will place the box-shadow on the visual edges of the element.

box-shadow on wrapper div

<div class="col-md-4">
    <div id="wrapper-div" style="box-shadow: 0px 2px 25px rgba(0, 0, 0, .25);">
        <div class="thumbnail">
            {!! HTML::image('images/sampleImage.png') !!}
        </div>
    </div>
</div>

regular expression: match any word until first space

Derived from the answer of @SilentGhost I would use:

^([\S]+)

Check out this interactive regexr.com page to see the result and explanation for the suggested solution.

How to set base url for rest in spring boot?

Since this is the first google hit for the problem and I assume more people will search for this. There is a new option since Spring Boot '1.4.0'. It is now possible to define a custom RequestMappingHandlerMapping that allows to define a different path for classes annotated with @RestController

A different version with custom annotations that combines @RestController with @RequestMapping can be found at this blog post

@Configuration
public class WebConfig {

    @Bean
    public WebMvcRegistrationsAdapter webMvcRegistrationsHandlerMapping() {
        return new WebMvcRegistrationsAdapter() {
            @Override
            public RequestMappingHandlerMapping getRequestMappingHandlerMapping() {
                return new RequestMappingHandlerMapping() {
                    private final static String API_BASE_PATH = "api";

                    @Override
                    protected void registerHandlerMethod(Object handler, Method method, RequestMappingInfo mapping) {
                        Class<?> beanType = method.getDeclaringClass();
                        if (AnnotationUtils.findAnnotation(beanType, RestController.class) != null) {
                            PatternsRequestCondition apiPattern = new PatternsRequestCondition(API_BASE_PATH)
                                    .combine(mapping.getPatternsCondition());

                            mapping = new RequestMappingInfo(mapping.getName(), apiPattern,
                                    mapping.getMethodsCondition(), mapping.getParamsCondition(),
                                    mapping.getHeadersCondition(), mapping.getConsumesCondition(),
                                    mapping.getProducesCondition(), mapping.getCustomCondition());
                        }

                        super.registerHandlerMethod(handler, method, mapping);
                    }
                };
            }
        };
    }
}

LaTeX source code listing like in professional books

For R code I use

\usepackage{listings}
\lstset{
language=R,
basicstyle=\scriptsize\ttfamily,
commentstyle=\ttfamily\color{gray},
numbers=left,
numberstyle=\ttfamily\color{gray}\footnotesize,
stepnumber=1,
numbersep=5pt,
backgroundcolor=\color{white},
showspaces=false,
showstringspaces=false,
showtabs=false,
frame=single,
tabsize=2,
captionpos=b,
breaklines=true,
breakatwhitespace=false,
title=\lstname,
escapeinside={},
keywordstyle={},
morekeywords={}
}

And it looks exactly like this

enter image description here

Get clicked item and its position in RecyclerView

Use below code:-

public class SergejAdapter extends RecyclerView.Adapter<SergejAdapter.MyViewHolder>{

...

class MyViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener{


    @Override
    public void onClick(View v) {
        // here you use position
        int position = getAdapterPosition();
        ...

    }
}
}

Python: How to remove empty lists from a list?

list1 = [[], [], [], [], [], 'text', 'text2', [], 'moreText']
list2 = []
for item in list1:
    if item!=[]:
        list2.append(item)
print(list2)

output:

['text', 'text2', 'moreText']

Javascript: Extend a Function

The other methods are great but they don't preserve any prototype functions attached to init. To get around that you can do the following (inspired by the post from Nick Craver).

(function () {
    var old_prototype = init.prototype;
    var old_init = init;
    init = function () {
        old_init.apply(this, arguments);
        // Do something extra
    };
    init.prototype = old_prototype;
}) ();

How to sign an android apk file

I ran into this problem and was solved by checking the min sdk version in the manifest. It was set to 15 (ICS), but my phone was running 10(Gingerbread)

How to open the Google Play Store directly from my Android application?

Peoples, dont forget that you could actually get something more from it. I mean UTM tracking for example. https://developers.google.com/analytics/devguides/collection/android/v4/campaigns

public static final String MODULE_ICON_PACK_FREE = "com.example.iconpack_free";
public static final String APP_STORE_URI =
        "market://details?id=%s&referrer=utm_source=%s&utm_medium=app&utm_campaign=plugin";
public static final String APP_STORE_GENERIC_URI =
        "https://play.google.com/store/apps/details?id=%s&referrer=utm_source=%s&utm_medium=app&utm_campaign=plugin";

try {
    startActivity(new Intent(
        Intent.ACTION_VIEW,
        Uri.parse(String.format(Locale.US,
            APP_STORE_URI,
            MODULE_ICON_PACK_FREE,
            getPackageName()))).addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP));
} catch (android.content.ActivityNotFoundException anfe) {
    startActivity(new Intent(
        Intent.ACTION_VIEW,
        Uri.parse(String.format(Locale.US,
            APP_STORE_GENERIC_URI,
            MODULE_ICON_PACK_FREE,
            getPackageName()))).addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP));
}

MySQL select one column DISTINCT, with corresponding other columns

SELECT DISTINCT(firstName), ID, LastName from tableName GROUP BY firstName

Would be the best bet IMO

Checking if a character is a special character in Java

You can use regular expressions.

String input = ...
if (input.matches("[^a-zA-Z0-9 ]"))

If your definition of a 'special character' is simply anything that doesn't apply to your other filters that you already have, then you can simply add an else. Also note that you have to use else if in this case:

if(c == ' ') {
    blankCount++;
} else if (Character.isDigit(c)) {
    digitCount++;
} else if (Character.isLetter(c)) {
    letterCount++;
} else { 
  specialcharCount++;
}

Converting double to string

double total = 44;
String total2= new Double(total).toString();

this code works

How to set background color of a button in Java GUI?

Use the setBackground method to set the background and setForeground to change the colour of your text. Note however, that putting grey text over a black background might make your text a bit tough to read.

Equivalent of varchar(max) in MySQL?

The max length of a varchar in MySQL 5.6.12 is 4294967295.

"Char cannot be dereferenced" error

I guess ch is a declared as char. Since char is a primitive data type and not and object, you can't call any methof from it. You should use Character.isLetter(ch).

SQL split values to multiple rows

Best Practice. Result:

SELECT
SUBSTRING_INDEX(SUBSTRING_INDEX('ab,bc,cd',',',help_id+1),',',-1) AS oid
FROM
(
SELECT @xi:=@xi+1 as help_id from 
(SELECT 1 UNION SELECT 2 UNION SELECT 3 UNION SELECT 4 UNION SELECT 5) xc1,
(SELECT 1 UNION SELECT 2 UNION SELECT 3 UNION SELECT 4 UNION SELECT 5) xc2,
(SELECT @xi:=-1) xc0
) a
WHERE 
help_id < LENGTH('ab,bc,cd')-LENGTH(REPLACE('ab,bc,cd',',',''))+1

First, create a numbers table:

SELECT @xi:=@xi+1 as help_id from 
(SELECT 1 UNION SELECT 2 UNION SELECT 3 UNION SELECT 4 UNION SELECT 5) xc1,
(SELECT 1 UNION SELECT 2 UNION SELECT 3 UNION SELECT 4 UNION SELECT 5) xc2,
(SELECT @xi:=-1) xc0;
| help_id  |
| --- |
| 0   |
| 1   |
| 2   |
| 3   |
| ...   |
| 24   |

Second, just split the str:

SELECT SUBSTRING_INDEX(SUBSTRING_INDEX('ab,bc,cd',',',help_id+1),',',-1) AS oid
FROM
numbers_table
WHERE
help_id < LENGTH('ab,bc,cd')-LENGTH(REPLACE('ab,bc,cd',',',''))+1
| oid  |
| --- |
| ab   |
| bc   |
| cd   |

How to implement a lock in JavaScript

JavaScript is, with a very few exceptions (XMLHttpRequest onreadystatechange handlers in some versions of Firefox) event-loop concurrent. So you needn't worry about locking in this case.

JavaScript has a concurrency model based on an "event loop". This model is quite different than the model in other languages like C or Java.

...

A JavaScript runtime contains a message queue, which is a list of messages to be processed. To each message is associated a function. When the stack is empty, a message is taken out of the queue and processed. The processing consists of calling the associated function (and thus creating an initial stack frame) The message processing ends when the stack becomes empty again.

...

Each message is processed completely before any other message is processed. This offers some nice properties when reasoning about your program, including the fact that whenever a function runs, it cannot be pre-empted and will run entirely before any other code runs (and can modify data the function manipulates). This differs from C, for instance, where if a function runs in a thread, it can be stopped at any point to run some other code in another thread.

A downside of this model is that if a message takes too long to complete, the web application is unable to process user interactions like click or scroll. The browser mitigates this with the "a script is taking too long to run" dialog. A good practice to follow is to make message processing short and if possible cut down one message into several messages.

For more links on event-loop concurrency, see E

Should I URL-encode POST data?

curl will encode the data for you, just drop your raw field data into the fields array and tell it to "go".

How to pop an alert message box using PHP?

You can use DHP to do this. It is absolutely simple and it is fast than script. Just write alert('something'); It is not programing language it is something like a lit bit jquery. You need require dhp.php in the top and in the bottom require dhpjs.php. For now it is not open source but when it is you can use it. It is our programing language ;)

How do I install PIL/Pillow for Python 3.6?

You can download the wheel corresponding to your configuration here ("Pillow-4.1.1-cp36-cp36m-win_amd64.whl" in your case) and install it with:

pip install some-package.whl

If you have problem to install the wheel read this answer

How can I fix the form size in a C# Windows Forms application and not to let user change its size?

I'm pretty sure this isn't the BEST way, but you could set the MinimumSize and MaximimSize properties to the same value. That will stop it.

Resize image proportionally with CSS?

We can resize image using CSS in the browser using media queries and the principle of responsive design.

    @media screen and (orientation: portrait) {
img.ri {
    max-width: 80%;
  }
}

_x000D_
_x000D_
@media screen and (orientation: landscape) {_x000D_
  img.ri { max-height: 80%; }_x000D_
}
_x000D_
_x000D_
_x000D_

Checking if form has been submitted - PHP

if ($_SERVER['REQUEST_METHOD'] == 'POST').

How can I verify if a Windows Service is running

Here you get all available services and their status in your local machine.

ServiceController[] services = ServiceController.GetServices();
foreach(ServiceController service in services)
{
    Console.WriteLine(service.ServiceName+"=="+ service.Status);
}

You can Compare your service with service.name property inside loop and you get status of your service. For details go with the http://msdn.microsoft.com/en-us/library/system.serviceprocess.servicecontroller.aspx also http://msdn.microsoft.com/en-us/library/microsoft.windows.design.servicemanager(v=vs.90).aspx