Programs & Examples On #Database update

jQuery get the name of a select option

Firstly name isn't a valid attribute of an option element. Instead you could use a data parameter, like this:

<option value="foo" data-name="bar">Foo Bar</option>

The main issue you have is that the JS is looking at the name attribute of the select element, not the chosen option. Try this:

$('#band_type_choices').on('change', function() {         
    $('.checkboxlist').hide();
    $('#checkboxlist_' + $('option:selected', this).data("name")).css("display", "block");
});

Note the option:selected selector within the context of the select which raised the change event.

Rename Oracle Table or View

To rename a table you can use:

RENAME mytable TO othertable;

or

ALTER TABLE mytable RENAME TO othertable;

or, if owned by another schema:

ALTER TABLE owner.mytable RENAME TO othertable;

Interestingly, ALTER VIEW does not support renaming a view. You can, however:

RENAME myview TO otherview;

The RENAME command works for tables, views, sequences and private synonyms, for your own schema only.

If the view is not in your schema, you can recompile the view with the new name and then drop the old view.

(tested in Oracle 10g)

How to comment out a block of Python code in Vim

Highlight your block with: ShiftV

Comment the selected block out with: :norm i# (lower case i)

To uncomment, highlight your block again, and uncomment with: :norm ^x

The :norm command performs an action for every selected line. Commenting will insert a # at the start of every line, and uncommenting will delete that #.

Maven2: Best practice for Enterprise Project (EAR file)

What helped me a lot was to run the Maven archetype:generate goal and select from one of the archetypes, some of which seem to be updated regularly (in particular JBoss seems to be well maintained).

mvn archetype:generate

Hundreds of archetypes appeared in a numbered list from which to select (519 as of now!). The goal, still running, prompted me to make a selection by entering a number or entering a search string e.g.:

513: remote -> org.xwiki.commons:xwiki-commons-component-archetype
514: remote -> org.xwiki.rendering:xwiki-rendering-archetype-macro
515: remote -> org.zkoss:zk-archetype-component
516: remote -> org.zkoss:zk-archetype-webapp
517: remote -> ru.circumflex:circumflex-archetype (-)
518: remote -> se.vgregion.javg.maven.archetypes:javg-minimal-archetype (-)
Choose a number or apply filter (format: [groupId:]artifactId, case sensitive contains):

I entered the search string "ear," which reduced the list to only 8 items (as of today):

Choose archetype:
1: remote -> org.codehaus.mojo.archetypes:ear-j2ee14 (-)
2: remote -> org.codehaus.mojo.archetypes:ear-javaee6 (-)
3: remote -> org.codehaus.mojo.archetypes:ear-jee5 (-)
4: remote -> org.hibernate:hibernate-search-quickstart (-)
5: remote -> org.jboss.spec.archetypes:jboss-javaee6-ear-webapp 
6: remote -> org.jboss.spec.archetypes:jboss-javaee6-webapp-ear-archetype
7: remote -> org.jboss.spec.archetypes:jboss-javaee6-webapp-ear-archetype-blank
8: remote -> org.ow2.weblab.tools.maven:weblab-archetype-searcher

I selected "org.jboss.spec.archetypes:jboss-javaee6-ear-webapp" (by entering the selection "5" in this example).

Next, the goal asked me to enter the groupId, artifactId, package names, etc., and it then generated the following well-documented example application:

[pgarner@localhost Foo]$ tree
.
|-- Foo-ear
|   `-- pom.xml
|-- Foo-ejb
|   |-- pom.xml
|   `-- src
|       |-- main
|       |   |-- java
|       |   |   `-- com
|       |   |       `-- foo
|       |   |           |-- controller
|       |   |           |   `-- MemberRegistration.java
|       |   |           |-- data
|       |   |           |   `-- MemberListProducer.java
|       |   |           |-- model
|       |   |           |   `-- Member.java
|       |   |           `-- util
|       |   |               `-- Resources.java
|       |   `-- resources
|       |       |-- import.sql
|       |       `-- META-INF
|       |           |-- beans.xml
|       |           `-- persistence.xml
|       `-- test
|           |-- java
|           |   `-- com
|           |       `-- foo
|           |           `-- test
|           |               `-- MemberRegistrationTest.java
|           `-- resources
|-- Foo-web
|   |-- pom.xml
|   `-- src
|       `-- main
|           |-- java
|           |   `-- com
|           |       `-- foo
|           |           `-- rest
|           |               |-- JaxRsActivator.java
|           |               `-- MemberResourceRESTService.java
|           `-- webapp
|               |-- index.html
|               |-- index.xhtml
|               |-- resources
|               |   |-- css
|               |   |   `-- screen.css
|               |   `-- gfx
|               |       |-- banner.png
|               |       `-- logo.png
|               `-- WEB-INF
|                   |-- beans.xml
|                   |-- faces-config.xml
|                   `-- templates
|                       `-- default.xhtml
|-- pom.xml
`-- README.md

32 directories, 23 files

After reading the four POM files, which were well-commented, I had pretty much all the information I needed.

./pom.xml
./Foo-ear/pom.xml
./Foo-ejb/pom.xml
./Foo-web/pom.xml

php get values from json encode

json_decode() will return an object or array if second value it's true:

$json = '{"countryId":"84","productId":"1","status":"0","opId":"134"}';
$json = json_decode($json, true);
echo $json['countryId'];
echo $json['productId'];
echo $json['status'];
echo $json['opId'];

Android appcompat v7:23

Ran into a similar issue using React Native

> Could not find com.android.support:appcompat-v7:23.0.1.

the Support Libraries are Local Maven repository for Support Libraries

enter image description here

Unable to open project... cannot be opened because the project file cannot be parsed

If you ever merge and still get problems that dont know what they are, I mean not the obvious marks of a diff

<<<<<
....
======
>>>>>>

Then you can analise your project files with https://github.com/Karumi/Kin, install it and use it

kin project.pbxproj

It has make extrange erros that doesn't allow open the project more easy to understand and solve (ones of hashes, groups and so on).


And by the way, this could also be helpful, thought I have not used it try to diff 2 versions of your project files https://github.com/bloomberg/xcdiff so this will give you really what is going on.

How to take backup of a single table in a MySQL database?

You can either use mysqldump from the command line:

mysqldump -u username -p password dbname tablename > "path where you want to dump"

You can also use MySQL Workbench:

Go to left > Data Export > Select Schema > Select tables and click on Export

Check string length in PHP

$message is propably not a string at all, but an array. Use $message[0] to access the first element.

add column to mysql table if it does not exist

$smpt = $pdo->prepare("SHOW fields FROM __TABLE__NAME__");
$smpt->execute();
$res = $smpt->fetchAll(PDO::FETCH_ASSOC);
//print_r($res);

Then in $res by cycle look for key of your column Smth like this:

    if($field['Field'] == '_my_col_'){
       return true;
    }
+

**Below code is good for checking column existing in the WordPress tables:**
public static function is_table_col_exists($table, $col)
    {
        global $wpdb;
        $fields = $wpdb->get_results("SHOW fields FROM {$table}", ARRAY_A);
        foreach ($fields as $field)
        {
            if ($field['Field'] == $col)
            {
                return TRUE;
            }
        }

        return FALSE;
    }

Beginner Python: AttributeError: 'list' object has no attribute

They are lists because you type them as lists in the dictionary:

bikes = {
    # Bike designed for children"
    "Trike": ["Trike", 20, 100],
    # Bike designed for everyone"
    "Kruzer": ["Kruzer", 50, 165]
    }

You should use the bike-class instead:

bikes = {
    # Bike designed for children"
    "Trike": Bike("Trike", 20, 100),
    # Bike designed for everyone"
    "Kruzer": Bike("Kruzer", 50, 165)
    }

This will allow you to get the cost of the bikes with bike.cost as you were trying to.

for bike in bikes.values():
    profit = bike.cost * margin
    print(bike.name + " : " + str(profit))

This will now print:

Kruzer : 33.0
Trike : 20.0

PHP display image BLOB from MySQL

This is what I use to display images from blob:

echo '<img src="data:image/jpeg;base64,'.base64_encode($image->load()) .'" />';

Detecting superfluous #includes in C/C++?

This article explains a technique of #include removing by using the parsing of Doxygen. That's just a perl script, so it's quite easy to use.

How can I have grep not print out 'No such file or directory' errors?

Use -I in grep.

Example: grep SEARCH_ME -Irs ~/logs.

Why does Boolean.ToString output "True" and not "true"

This probably harks from the old VB NOT .Net days when bool.ToString produced True or False.

rotate image with css

Perform rotation using transform: rotate(xdeg) and also apply overflow: hidden to the parent component to avoid overlapping effect

.div-parent {
   overflow: hidden
}

.div-child {
   transform: rotate(270deg);
}

Select rows with same id but different value in another column

Join the same table back to itself. Use an inner join so that rows that don't match are discarded. In the joined set, there will be rows that have a matching ARIDNR in another row in the table with a different LIEFNR. Allow those ARIDNR to appear in the final set.

SELECT * FROM YourTable WHERE ARIDNR IN (
    SELECT a.ARIDNR FROM YourTable a
    JOIN YourTable b on b.ARIDNR = a.ARIDNR AND b.LIEFNR <> a.LIEFNR
)

How to use ng-repeat without an html element

The above is correct but for a more general answer it is not enough. I needed to nest ng-repeat, but stay on the same html level, meaning write the elements in the same parent. The tags array contain tag(s) that also have a tags array. It is actually a tree.

[{ name:'name1', tags: [
  { name: 'name1_1', tags: []},
  { name: 'name1_2', tags: []}
  ]},
 { name:'name2', tags: [
  { name: 'name2_1', tags: []},
  { name: 'name2_2', tags: []}
  ]}
]

So here is what I eventually did.

<div ng-repeat-start="tag1 in tags" ng-if="false"></div>
    {{tag1}},
  <div ng-repeat-start="tag2 in tag1.tags" ng-if="false"></div>
    {{tag2}},
  <div ng-repeat-end ng-if="false"></div>
<div ng-repeat-end ng-if="false"></div>

Note the ng-if="false" that hides the start and end divs.

It should print

name1,name1_1,name1_2,name2,name2_1,name2_2,

How to copy text from a div to clipboard

<div id='myInputF2'> YES ITS DIV TEXT TO COPY  </div>

<script>

    function myFunctionF2()  {
        str = document.getElementById('myInputF2').innerHTML;
        const el = document.createElement('textarea');
        el.value = str;
        document.body.appendChild(el);
        el.select();
        document.execCommand('copy');
        document.body.removeChild(el);
        alert('Copied the text:' + el.value);
    };
</script>

more info: https://hackernoon.com/copying-text-to-clipboard-with-javascript-df4d4988697f

error: command 'gcc' failed with exit status 1 while installing eventlet

Build from source and install, this is fixed in the latest release (10.3+):

mkdir -p /tmp/install/netifaces/
cd /tmp/install/netifaces && wget -O "netifaces-0.10.4.tar.gz" "https://pypi.python.org/packages/source/n/netifaces/netifaces-0.10.4.tar.gz#md5=36da76e2cfadd24cc7510c2c0012eb1e"
tar xvzf netifaces-0.10.4.tar.gz
cd netifaces-0.10.4 && python setup.py install

How to create a shared library with cmake?

First, this is the directory layout that I am using:

.
+-- include
¦   +-- class1.hpp
¦   +-- ...
¦   +-- class2.hpp
+-- src
    +-- class1.cpp
    +-- ...
    +-- class2.cpp

After a couple of days taking a look into this, this is my favourite way of doing this thanks to modern CMake:

cmake_minimum_required(VERSION 3.5)
project(mylib VERSION 1.0.0 LANGUAGES CXX)

set(DEFAULT_BUILD_TYPE "Release")

if(NOT CMAKE_BUILD_TYPE AND NOT CMAKE_CONFIGURATION_TYPES)
  message(STATUS "Setting build type to '${DEFAULT_BUILD_TYPE}' as none was specified.")
  set(CMAKE_BUILD_TYPE "${DEFAULT_BUILD_TYPE}" CACHE STRING "Choose the type of build." FORCE)
  # Set the possible values of build type for cmake-gui
  set_property(CACHE CMAKE_BUILD_TYPE PROPERTY STRINGS "Debug" "Release" "MinSizeRel" "RelWithDebInfo")
endif()

include(GNUInstallDirs)

set(SOURCE_FILES src/class1.cpp src/class2.cpp)

add_library(${PROJECT_NAME} ...)

target_include_directories(${PROJECT_NAME} PUBLIC
    $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/include>
    $<INSTALL_INTERFACE:include>
    PRIVATE src)

set_target_properties(${PROJECT_NAME} PROPERTIES
    VERSION ${PROJECT_VERSION}
    SOVERSION 1)

install(TARGETS ${PROJECT_NAME} EXPORT MyLibConfig
    ARCHIVE  DESTINATION ${CMAKE_INSTALL_LIBDIR}
    LIBRARY  DESTINATION ${CMAKE_INSTALL_LIBDIR}
    RUNTIME  DESTINATION ${CMAKE_INSTALL_BINDIR})
install(DIRECTORY include/ DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}/${PROJECT_NAME})

install(EXPORT MyLibConfig DESTINATION share/MyLib/cmake)

export(TARGETS ${PROJECT_NAME} FILE MyLibConfig.cmake)

After running CMake and installing the library, there is no need to use Find***.cmake files, it can be used like this:

find_package(MyLib REQUIRED)

#No need to perform include_directories(...)
target_link_libraries(${TARGET} mylib)

That's it, if it has been installed in a standard directory it will be found and there is no need to do anything else. If it has been installed in a non-standard path, it is also easy, just tell CMake where to find MyLibConfig.cmake using:

cmake -DMyLib_DIR=/non/standard/install/path ..

I hope this helps everybody as much as it has helped me. Old ways of doing this were quite cumbersome.

How to delete row in gridview using rowdeleting event?

protected void GridView1_RowDeleting(object sender, GridViewDeleteEventArgs e)
{
    MySqlCommand cmd;
    string id1 = GridView1.DataKeys[e.RowIndex].Value.ToString();
    con.Open();
    cmd = new MySqlCommand("delete from tableName where refno='" + id1 + "'", con);
    cmd.ExecuteNonQuery();
    con.Close();
    BindView();
}
private void BindView()
{
    GridView1.DataSource = ms.dTable("select * from table_name");
    GridView1.DataBind();
}

getOutputStream() has already been called for this response

In some cases this case occurs when you declare

Writer out=response.getWriter   

after declaring or using RequestDispatcher.

I encountered this similar problem while creating a simple LoginServlet, where I have defined Writer after declaring RequestDispatcher.

Try defining Writer class object before RequestDispatcher class.

Git 'fatal: Unable to write new index file'

This worked for me:

rm -f ./.git/index.lock

"No X11 DISPLAY variable" - what does it mean?

Very Easy, Had this same problem then what i did was to download and install an app that would help in displaying then fixed the error.

Download this app xming:

http://sourceforge.net/project/downloading.php?

Install, then use settings on this link:

http://www.geo.mtu.edu/geoschem/docs/putty_install.html or follow this steps:

Installing/Configuring PuTTy and Xming

Once PuTTy and Xming have been downloaded to the PC, install according to their respective instructions.

Configuring Xming

Once Xming is installed, run the application called 'XLaunch' and verify that the settings are as shown:

  • select Default entries on Display Settings windows, click next
  • click next on Session Type window.
  • click next on Additional parameters window(Notice clipboard checkbox is true)
  • save configuration and click to finish.

Configuring PuTTy

After installing PuTTy, double-click on the PuTTy icon on the desktop and configure as shown:

This shows creating a login profile then saving it.

  • On ssh -> X11, click on checkbox to enable X11 forwarding.
  • on X display location textbox, type localhost:0.0

save profile then connect remotely to server to test.

Cheers!!!

Difference between classification and clustering in data mining?

I'm a new comer to Data Mining, but as my textbook says, CLASSICIATION is supposed to be supervised learning, and CLUSTERING unsupervised learning. The difference between supervised learning and unsupervised learning can be found here.

Is It Possible to NSLog C Structs (Like CGRect or CGPoint)?

There are a few functions like:

NSStringFromCGPoint  
NSStringFromCGSize  
NSStringFromCGRect  
NSStringFromCGAffineTransform  
NSStringFromUIEdgeInsets

An example:

NSLog(@"rect1: %@", NSStringFromCGRect(rect1));

Python str vs unicode types

Unicode and encodings are completely different, unrelated things.

Unicode

Assigns a numeric ID to each character:

  • 0x41 ? A
  • 0xE1 ? á
  • 0x414 ? ?

So, Unicode assigns the number 0x41 to A, 0xE1 to á, and 0x414 to ?.

Even the little arrow ? I used has its Unicode number, it's 0x2192. And even emojis have their Unicode numbers, is 0x1F602.

You can look up the Unicode numbers of all characters in this table. In particular, you can find the first three characters above here, the arrow here, and the emoji here.

These numbers assigned to all characters by Unicode are called code points.

The purpose of all this is to provide a means to unambiguously refer to a each character. For example, if I'm talking about , instead of saying "you know, this laughing emoji with tears", I can just say, Unicode code point 0x1F602. Easier, right?

Note that Unicode code points are usually formatted with a leading U+, then the hexadecimal numeric value padded to at least 4 digits. So, the above examples would be U+0041, U+00E1, U+0414, U+2192, U+1F602.

Unicode code points range from U+0000 to U+10FFFF. That is 1,114,112 numbers. 2048 of these numbers are used for surrogates, thus, there remain 1,112,064. This means, Unicode can assign a unique ID (code point) to 1,112,064 distinct characters. Not all of these code points are assigned to a character yet, and Unicode is extended continuously (for example, when new emojis are introduced).

The important thing to remember is that all Unicode does is to assign a numerical ID, called code point, to each character for easy and unambiguous reference.

Encodings

Map characters to bit patterns.

These bit patterns are used to represent the characters in computer memory or on disk.

There are many different encodings that cover different subsets of characters. In the English-speaking world, the most common encodings are the following:

ASCII

Maps 128 characters (code points U+0000 to U+007F) to bit patterns of length 7.

Example:

  • a ? 1100001 (0x61)

You can see all the mappings in this table.

ISO 8859-1 (aka Latin-1)

Maps 191 characters (code points U+0020 to U+007E and U+00A0 to U+00FF) to bit patterns of length 8.

Example:

  • a ? 01100001 (0x61)
  • á ? 11100001 (0xE1)

You can see all the mappings in this table.

UTF-8

Maps 1,112,064 characters (all existing Unicode code points) to bit patterns of either length 8, 16, 24, or 32 bits (that is, 1, 2, 3, or 4 bytes).

Example:

  • a ? 01100001 (0x61)
  • á ? 11000011 10100001 (0xC3 0xA1)
  • ? ? 11100010 10001001 10100000 (0xE2 0x89 0xA0)
  • ? 11110000 10011111 10011000 10000010 (0xF0 0x9F 0x98 0x82)

The way UTF-8 encodes characters to bit strings is very well described here.

Unicode and Encodings

Looking at the above examples, it becomes clear how Unicode is useful.

For example, if I'm Latin-1 and I want to explain my encoding of á, I don't need to say:

"I encode that a with an aigu (or however you call that rising bar) as 11100001"

But I can just say:

"I encode U+00E1 as 11100001"

And if I'm UTF-8, I can say:

"Me, in turn, I encode U+00E1 as 11000011 10100001"

And it's unambiguously clear to everybody which character we mean.

Now to the often arising confusion

It's true that sometimes the bit pattern of an encoding, if you interpret it as a binary number, is the same as the Unicode code point of this character.

For example:

  • ASCII encodes a as 1100001, which you can interpret as the hexadecimal number 0x61, and the Unicode code point of a is U+0061.
  • Latin-1 encodes á as 11100001, which you can interpret as the hexadecimal number 0xE1, and the Unicode code point of á is U+00E1.

Of course, this has been arranged like this on purpose for convenience. But you should look at it as a pure coincidence. The bit pattern used to represent a character in memory is not tied in any way to the Unicode code point of this character.

Nobody even says that you have to interpret a bit string like 11100001 as a binary number. Just look at it as the sequence of bits that Latin-1 uses to encode the character á.

Back to your question

The encoding used by your Python interpreter is UTF-8.

Here's what's going on in your examples:

Example 1

The following encodes the character á in UTF-8. This results in the bit string 11000011 10100001, which is saved in the variable a.

>>> a = 'á'

When you look at the value of a, its content 11000011 10100001 is formatted as the hex number 0xC3 0xA1 and output as '\xc3\xa1':

>>> a
'\xc3\xa1'

Example 2

The following saves the Unicode code point of á, which is U+00E1, in the variable ua (we don't know which data format Python uses internally to represent the code point U+00E1 in memory, and it's unimportant to us):

>>> ua = u'á'

When you look at the value of ua, Python tells you that it contains the code point U+00E1:

>>> ua
u'\xe1'

Example 3

The following encodes Unicode code point U+00E1 (representing character á) with UTF-8, which results in the bit pattern 11000011 10100001. Again, for output this bit pattern is represented as the hex number 0xC3 0xA1:

>>> ua.encode('utf-8')
'\xc3\xa1'

Example 4

The following encodes Unicode code point U+00E1 (representing character á) with Latin-1, which results in the bit pattern 11100001. For output, this bit pattern is represented as the hex number 0xE1, which by coincidence is the same as the initial code point U+00E1:

>>> ua.encode('latin1')
'\xe1'

There's no relation between the Unicode object ua and the Latin-1 encoding. That the code point of á is U+00E1 and the Latin-1 encoding of á is 0xE1 (if you interpret the bit pattern of the encoding as a binary number) is a pure coincidence.

How to push object into an array using AngularJS

_x000D_
_x000D_
  var app = angular.module('myApp', []);_x000D_
        app.controller('myCtrl', function ($scope) {_x000D_
_x000D_
            //Comments object having reply oject_x000D_
            $scope.comments = [{ comment: 'hi', reply: [{ comment: 'hi inside commnet' }, { comment: 'hi inside commnet' }] }];_x000D_
_x000D_
            //push reply_x000D_
            $scope.insertReply = function (index, reply) {_x000D_
                $scope.comments[index].reply.push({ comment: reply });_x000D_
            }_x000D_
_x000D_
            //push commnet_x000D_
            $scope.newComment = function (comment) {_x000D_
                $scope.comments.push({ comment:comment, reply: [] });_x000D_
            }_x000D_
        });
_x000D_
<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.2.23/angular.min.js"></script>_x000D_
<div ng-app="myApp" ng-controller="myCtrl">_x000D_
_x000D_
        <!--Comment section-->_x000D_
        <ul ng-repeat="comment in comments track by $index" style="background: skyblue; padding: 10px;">_x000D_
            <li>_x000D_
                <b>Comment {{$index}} : </b>_x000D_
                <br>_x000D_
                {{comment.comment}}_x000D_
                <!--Reply section-->_x000D_
                    <ul ng-repeat="reply in comment.reply track by $index">_x000D_
                        <li><i>Reply {{$index}} :</i><br>_x000D_
                            {{reply.comment}}</li>_x000D_
                    </ul>_x000D_
                <!--End reply section-->_x000D_
                <input type="text" ng-model="reply" placeholder=" Write your reply." /><a href="" ng-click="insertReply($index,reply)">Reply</a>_x000D_
            </li>_x000D_
        </ul>_x000D_
        <!--End comment section -->_x000D_
            _x000D_
_x000D_
        <!--Post your comment-->_x000D_
        <b>New comment</b>_x000D_
        <input type="text" placeholder="Your comment" ng-model="comment" />_x000D_
        <a href="" ng-click="newComment(comment)">Post </a>_x000D_
    </div>
_x000D_
_x000D_
_x000D_

What are the benefits to marking a field as `readonly` in C#?

To put it in very practical terms:

If you use a const in dll A and dll B references that const, the value of that const will be compiled into dll B. If you redeploy dll A with a new value for that const, dll B will still be using the original value.

If you use a readonly in dll A and dll B references that readonly, that readonly will always be looked up at runtime. This means if you redeploy dll A with a new value for that readonly, dll B will use that new value.

How to create a HTML Cancel button that redirects to a URL

There are a few problems here.

First of all, there is no such thing as <button type="cancel">, so it is treated as just a <button>. This means that your form will be submitted, instead of the button taking you elsewhere.

Second, javascript: is only needed in href or action attributes, where a URL is expected, to designate JavaScript code. Inside onclick, where JavaScript is already expected, it merely acts as a label and serves no real purpose.

Finally, it's just generally better design to have a cancel link rather than a cancel button. So you can just do this:

<a href="http://stackoverflow.com/">Cancel</a>

With CSS you can even make it look the same as a button, but with this HTML there is absolutely no confusion as to what it is supposed to do.

Why use double indirection? or Why use pointers to pointers?

Strings are a great example of uses of double pointers. The string itself is a pointer, so any time you need to point to a string, you'll need a double pointer.

Need to install urllib2 for Python 3.5.1

Acording to the docs:

Note The urllib2 module has been split across several modules in Python 3 named urllib.request and urllib.error. The 2to3 tool will automatically adapt imports when converting your sources to Python 3.

So it appears that it is impossible to do what you want but you can use appropriate python3 functions from urllib.request.

What is the Difference Between Mercurial and Git?

There is a dynamic comparison chart over at the versioncontrolblog where you can compare several different version control systems.

Here is a comparison table between git, hg and bzr.

PHP substring extraction. Get the string before the first '/' or the whole string

You can try using a regex like this:

$s = preg_replace('|/.*$|', '', $s);

sometimes, regex are slower though, so if performance is an issue, make sure to benchmark this properly and use an other alternative with substrings if it's more suitable for you.

How to pass table value parameters to stored procedure from .net code

Use this code to create suitable parameter from your type:

private SqlParameter GenerateTypedParameter(string name, object typedParameter)
{
    DataTable dt = new DataTable();

    var properties = typedParameter.GetType().GetProperties().ToList();
    properties.ForEach(p =>
    {
        dt.Columns.Add(p.Name, Nullable.GetUnderlyingType(p.PropertyType) ?? p.PropertyType);
    });
    var row = dt.NewRow();
    properties.ForEach(p => { row[p.Name] = (p.GetValue(typedParameter) ?? DBNull.Value); });
    dt.Rows.Add(row);

    return new SqlParameter
    {
        Direction = ParameterDirection.Input,
        ParameterName = name,
        Value = dt,
        SqlDbType = SqlDbType.Structured
    };
}

iptables LOG and DROP in one rule

Example:

iptables -A INPUT -j LOG --log-prefix "INPUT:DROP:" --log-level 6
iptables -A INPUT -j DROP

Log Exampe:

Feb 19 14:18:06 servername kernel: INPUT:DROP:IN=eth1 OUT= MAC=aa:bb:cc:dd:ee:ff:11:22:33:44:55:66:77:88 SRC=x.x.x.x DST=x.x.x.x LEN=48 TOS=0x00 PREC=0x00 TTL=117 ID=x PROTO=TCP SPT=x DPT=x WINDOW=x RES=0x00 SYN URGP=0

Other options:

   LOG
       Turn on kernel logging of matching packets.  When this option 
       is set for a rule, the Linux kernel will print some 
       information  on  all  matching  packets
       (like most IP header fields) via the kernel log (where it can 
       be read with dmesg or syslogd(8)).  This is a "non-terminating 
       target", i.e. rule traversal
       continues at the next rule.  So if you want to LOG the packets 
       you refuse, use two separate rules with the same matching 
       criteria, first using target LOG
       then DROP (or REJECT).

       --log-level level
              Level of logging (numeric or see syslog.conf(5)).

       --log-prefix prefix
              Prefix log messages with the specified prefix; up to 29 
              letters long, and useful for distinguishing messages in 
              the logs.

       --log-tcp-sequence
              Log TCP sequence numbers. This is a security risk if the 
              log is readable by users.

       --log-tcp-options
              Log options from the TCP packet header.

       --log-ip-options
              Log options from the IP packet header.

       --log-uid
              Log the userid of the process which generated the packet.

There isn't anything to compare. Nothing to compare, branches are entirely different commit histories

I had a similar situation, where my master branch and the develop branch I was trying to merge had different commit histories. None of the above solutions worked for me. What did the trick was:

Starting from master:

git branch new_branch
git checkout new_branch
git merge develop --allow-unrelated-histories

Now in the new_branch, there are all the things from develop and I can easily merge into master, or create a pull request, as they now share the same commit hisotry.

How to find out what is locking my tables?

I have a stored procedure that I have put together, that deals not only with locks and blocking, but also to see what is running in a server. I have put it in master. I will share it with you, the code is below:

USE [master]
go


CREATE PROCEDURE [dbo].[sp_radhe] 

AS
BEGIN

SET TRANSACTION ISOLATION LEVEL READ UNCOMMITTED


-- the current_processes
-- marcelo miorelli 
-- CCHQ 
-- 04 MAR 2013 Wednesday

SELECT es.session_id AS session_id
,COALESCE(es.original_login_name, '') AS login_name
,COALESCE(es.host_name,'') AS hostname
,COALESCE(es.last_request_end_time,es.last_request_start_time) AS last_batch
,es.status
,COALESCE(er.blocking_session_id,0) AS blocked_by
,COALESCE(er.wait_type,'MISCELLANEOUS') AS waittype
,COALESCE(er.wait_time,0) AS waittime
,COALESCE(er.last_wait_type,'MISCELLANEOUS') AS lastwaittype
,COALESCE(er.wait_resource,'') AS waitresource
,coalesce(db_name(er.database_id),'No Info') as dbid
,COALESCE(er.command,'AWAITING COMMAND') AS cmd
,sql_text=st.text
,transaction_isolation =
CASE es.transaction_isolation_level
    WHEN 0 THEN 'Unspecified'
    WHEN 1 THEN 'Read Uncommitted'
    WHEN 2 THEN 'Read Committed'
    WHEN 3 THEN 'Repeatable'
    WHEN 4 THEN 'Serializable'
    WHEN 5 THEN 'Snapshot'
END
,COALESCE(es.cpu_time,0) 
    + COALESCE(er.cpu_time,0) AS cpu
,COALESCE(es.reads,0) 
    + COALESCE(es.writes,0) 
    + COALESCE(er.reads,0) 
+ COALESCE(er.writes,0) AS physical_io
,COALESCE(er.open_transaction_count,-1) AS open_tran
,COALESCE(es.program_name,'') AS program_name
,es.login_time
FROM sys.dm_exec_sessions es
LEFT OUTER JOIN sys.dm_exec_connections ec ON es.session_id = ec.session_id
LEFT OUTER JOIN sys.dm_exec_requests er ON es.session_id = er.session_id
LEFT OUTER JOIN sys.server_principals sp ON es.security_id = sp.sid
LEFT OUTER JOIN sys.dm_os_tasks ota ON es.session_id = ota.session_id
LEFT OUTER JOIN sys.dm_os_threads oth ON ota.worker_address = oth.worker_address
CROSS APPLY sys.dm_exec_sql_text(er.sql_handle) AS st
where es.is_user_process = 1 
  and es.session_id <> @@spid
  and es.status = 'running'
ORDER BY es.session_id

end 

GO

this procedure has done very good for me in the last couple of years. to run it just type sp_radhe

Regarding putting sp_radhe in the master database

I use the following code and make it a system stored procedure

exec sys.sp_MS_marksystemobject 'sp_radhe'

as you can see on the link below

Creating Your Own SQL Server System Stored Procedures

Regarding the transaction isolation level

Questions About T-SQL Transaction Isolation Levels You Were Too Shy to Ask

Jonathan Kehayias

Once you change the transaction isolation level it only changes when the scope exits at the end of the procedure or a return call, or if you change it explicitly again using SET TRANSACTION ISOLATION LEVEL.

In addition the TRANSACTION ISOLATION LEVEL is only scoped to the stored procedure, so you can have multiple nested stored procedures that execute at their own specific isolation levels.

java.security.cert.CertificateException: Certificates does not conform to algorithm constraints

this is more likely happening because somewhere along your certificate chain you have a certificate, more likely an old root, which is still signed with the MD2RSA algorythm.

You need to locate it into your certificate store and delete it.

Then get back to your certification authority and ask them for then new root.

It will more likely be the same root with the same validity period but it has been recertified with SHA1RSA.

Hope this help.

Hide "NFC Tag type not supported" error on Samsung Galaxy devices

Before Android 4.4

What you are trying to do is simply not possible from an app (at least not on a non-rooted/non-modified device). The message "NFC tag type not supported" is displayed by the Android system (or more specifically the NFC system service) before and instead of dispatching the tag to your app. This means that the NFC system service filters MIFARE Classic tags and never notifies any app about them. Consequently, your app can't detect MIFARE Classic tags or circumvent that popup message.

On a rooted device, you may be able to bypass the message using either

  1. Xposed to modify the behavior of the NFC service, or
  2. the CSC (Consumer Software Customization) feature configuration files on the system partition (see /system/csc/. The NFC system service disables the popup and dispatches MIFARE Classic tags to apps if the CSC feature <CscFeature_NFC_EnableSecurityPromptPopup> is set to any value but "mifareclassic" or "all". For instance, you could use:

    <CscFeature_NFC_EnableSecurityPromptPopup>NONE</CscFeature_NFC_EnableSecurityPromptPopup>
    

    You could add this entry to, for instance, the file "/system/csc/others.xml" (within the section <FeatureSet> ... </FeatureSet> that already exists in that file).

Since, you asked for the Galaxy S6 (the question that you linked) as well: I have tested this method on the S4 when it came out. I have not verified if this still works in the latest firmware or on other devices (e.g. the S6).

Since Android 4.4

This is pure guessing, but according to this (link no longer available), it seems that some apps (e.g. NXP TagInfo) are capable of detecting MIFARE Classic tags on affected Samsung devices since Android 4.4. This might mean that foreground apps are capable of bypassing that popup using the reader-mode API (see NfcAdapter.enableReaderMode) possibly in combination with NfcAdapter.FLAG_READER_SKIP_NDEF_CHECK.

TextView - setting the text size programmatically doesn't seem to work

the method TextView.setTextSize(int unit , float size); takes two parameters .

Try this :

text.setTextSize(TypedValue.COMPLEX_UNIT_SP,14);

refer this and this.

UPDATE: Now the setTextSize(float size) will set the text size automatically in "scaled pixel" units. no need to mention the COMPLEX_UNIT_SP manually. Refer to the documentation.

How do I append a node to an existing XML file in java

The following complete example will read an existing server.xml file from the current directory, append a new Server and re-write the file to server.xml. It does not work without an existing .xml file, so you will need to modify the code to handle that case.

import java.util.*;
import javax.xml.transform.*;
import javax.xml.transform.stream.*;
import javax.xml.transform.dom.*;
import org.w3c.dom.*;
import javax.xml.parsers.*;

public class AddXmlNode {
    public static void main(String[] args) throws Exception {

        DocumentBuilderFactory documentBuilderFactory = DocumentBuilderFactory.newInstance();
        DocumentBuilder documentBuilder = documentBuilderFactory.newDocumentBuilder();
        Document document = documentBuilder.parse("server.xml");
        Element root = document.getDocumentElement();

        Collection<Server> servers = new ArrayList<Server>();
        servers.add(new Server());

        for (Server server : servers) {
            // server elements
            Element newServer = document.createElement("server");

            Element name = document.createElement("name");
            name.appendChild(document.createTextNode(server.getName()));
            newServer.appendChild(name);

            Element port = document.createElement("port");
            port.appendChild(document.createTextNode(Integer.toString(server.getPort())));
            newServer.appendChild(port);

            root.appendChild(newServer);
        }

        DOMSource source = new DOMSource(document);

        TransformerFactory transformerFactory = TransformerFactory.newInstance();
        Transformer transformer = transformerFactory.newTransformer();
        StreamResult result = new StreamResult("server.xml");
        transformer.transform(source, result);
    }

    public static class Server {
        public String getName() { return "foo"; }
        public Integer getPort() { return 12345; }
    }
}

Example server.xml file:

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<Servers>
  <server>
    <name>something</name>
    <port>port</port>
  </server>
</Servers>

The main change to your code is not creating a new "root" element. The above example just uses the current root node from the existing server.xml and then just appends a new Server element and re-writes the file.

Real mouse position in canvas

The Simple 1:1 Scenario

For situations where the canvas element is 1:1 compared to the bitmap size, you can get the mouse positions by using this snippet:

function getMousePos(canvas, evt) {
    var rect = canvas.getBoundingClientRect();
    return {
      x: evt.clientX - rect.left,
      y: evt.clientY - rect.top
    };
}

Just call it from your event with the event and canvas as arguments. It returns an object with x and y for the mouse positions.

As the mouse position you are getting is relative to the client window you'll have to subtract the position of the canvas element to convert it relative to the element itself.

Example of integration in your code:

//put this outside the event loop..
var canvas = document.getElementById("imgCanvas");
var context = canvas.getContext("2d");

function draw(evt) {
    var pos = getMousePos(canvas, evt);

    context.fillStyle = "#000000";
    context.fillRect (pos.x, pos.y, 4, 4);
}

Note: borders and padding will affect position if applied directly to the canvas element so these needs to be considered via getComputedStyle() - or apply those styles to a parent div instead.

When Element and Bitmap are of different sizes

When there is the situation of having the element at a different size than the bitmap itself, for example, the element is scaled using CSS or there is pixel-aspect ratio etc. you will have to address this.

Example:

function  getMousePos(canvas, evt) {
  var rect = canvas.getBoundingClientRect(), // abs. size of element
      scaleX = canvas.width / rect.width,    // relationship bitmap vs. element for X
      scaleY = canvas.height / rect.height;  // relationship bitmap vs. element for Y

  return {
    x: (evt.clientX - rect.left) * scaleX,   // scale mouse coordinates after they have
    y: (evt.clientY - rect.top) * scaleY     // been adjusted to be relative to element
  }
}

With transformations applied to context (scale, rotation etc.)

Then there is the more complicated case where you have applied transformation to the context such as rotation, skew/shear, scale, translate etc. To deal with this you can calculate the inverse matrix of the current matrix.

Newer browsers let you read the current matrix via the currentTransform property and Firefox (current alpha) even provide a inverted matrix through the mozCurrentTransformInverted. Firefox however, via mozCurrentTransform, will return an Array and not DOMMatrix as it should. Neither Chrome, when enabled via experimental flags, will return a DOMMatrix but a SVGMatrix.

In most cases however you will have to implement a custom matrix solution of your own (such as my own solution here - free/MIT project) until this get full support.

When you eventually have obtained the matrix regardless of path you take to obtain one, you'll need to invert it and apply it to your mouse coordinates. The coordinates are then passed to the canvas which will use its matrix to convert it to back wherever it is at the moment.

This way the point will be in the correct position relative to the mouse. Also here you need to adjust the coordinates (before applying the inverse matrix to them) to be relative to the element.

An example just showing the matrix steps

function draw(evt) {
    var pos = getMousePos(canvas, evt);        // get adjusted coordinates as above
    var imatrix = matrix.inverse();            // get inverted matrix somehow
    pos = imatrix.applyToPoint(pos.x, pos.y);  // apply to adjusted coordinate

    context.fillStyle = "#000000";
    context.fillRect(pos.x-1, pos.y-1, 2, 2);
}

An example of using currentTransform when implemented would be:

    var pos = getMousePos(canvas, e);          // get adjusted coordinates as above
    var matrix = ctx.currentTransform;         // W3C (future)
    var imatrix = matrix.invertSelf();         // invert

    // apply to point:
    var x = pos.x * imatrix.a + pos.y * imatrix.c + imatrix.e;
    var y = pos.x * imatrix.b + pos.y * imatrix.d + imatrix.f;

Update I made a free solution (MIT) to embed all these steps into a single easy-to-use object that can be found here and also takes care of a few other nitty-gritty things most ignore.

Convert NSData to String?

Swift 5:

String(data: data!, encoding: String.Encoding.utf8)

How to return a table from a Stored Procedure?

It's VERY important to include:

 SET NOCOUNT ON;

into SP, In First line, if you do INSERT in SP, the END SELECT can't return values.

THEN, in vb60 you can:

SET RS = CN.EXECUTE(SQL)

OR:

RS.OPEN CN, RS, SQL

TypeError [ERR_INVALID_ARG_TYPE]: The "path" argument must be of type string. Received type undefined raised when starting react app

In my case, it was because I (at one point) had reactn installed, which also includes its own version of React (for some reason).

After that had been installed (even after uninstalling again), this error occured.

I simply removed node_modules and ran npm install again, and it worked.

How to call a function from a string stored in a variable?

What I learnt from this question and the answers. Thanks all!

Let say I have these variables and functions:

$functionName1 = "sayHello";
$functionName2 = "sayHelloTo";
$functionName3 = "saySomethingTo";

$friend = "John";
$datas = array(
    "something"=>"how are you?",
    "to"=>"Sarah"
);

function sayHello()
{
echo "Hello!";
}

function sayHelloTo($to)
{
echo "Dear $to, hello!";
}

function saySomethingTo($something, $to)
{
echo "Dear $to, $something";
}
  1. To call function without arguments

    // Calling sayHello()
    call_user_func($functionName1); 
    

    Hello!

  2. To call function with 1 argument

    // Calling sayHelloTo("John")
    call_user_func($functionName2, $friend);
    

    Dear John, hello!

  3. To call function with 1 or more arguments This will be useful if you are dynamically calling your functions and each function have different number of arguments. This is my case that I have been looking for (and solved). call_user_func_array is the key

    // You can add your arguments
    // 1. statically by hard-code, 
    $arguments[0] = "how are you?"; // my $something
    $arguments[1] = "Sarah"; // my $to
    
    // 2. OR dynamically using foreach
    $arguments = NULL;
    foreach($datas as $data) 
    {
        $arguments[] = $data;
    }
    
    // Calling saySomethingTo("how are you?", "Sarah")
    call_user_func_array($functionName3, $arguments);
    

    Dear Sarah, how are you?

Yay bye!

How to obtain the location of cacerts of the default java installation?

In MacOS Mojave, the location is:

/Library/Java/JavaVirtualMachines/jdk1.8.0_192.jdk/Contents/Home/jre/lib/security/cacerts 

If using sdkman to manage java versions, the cacerts is in

~/.sdkman/candidates/java/current/jre/lib/security

You need to use a Theme.AppCompat theme (or descendant) with this activity

min sdk is 10. ActionBar is available from api level 11. So for 10 you would be using AppCompat from the support library for which you need to use Theme.AppCompat or descendant of the same.

Use

android:theme="@style/Theme.AppCompat" >

Or if you dont want action bar at the top

android:theme="@style/Theme.AppCompat.NoActionBar">

More info @

http://developer.android.com/guide/topics/ui/actionbar.html

Edit:

I might have misread op post.

Seems op wants a Dialog with a Activity Theme. So as already suggested by Bobbake4 extend Activity instead of ActionBarActivity.

Also have a look @ Dialog Attributes in the link below

http://grepcode.com/file/repository.grepcode.com/java/ext/com.google.android/android/4.4_r1/frameworks/base/core/res/res/values/themes.xml/

Convert tuple to list and back

Since Python 3.5 (PEP 448 -- Additional Unpacking Generalizations) one can use the following literal syntax to convert a tuple to a list:

>>> t = (1,2,3)
>>> lst = [*t]
>>> lst
[1, 2, 3]
>>> *lst,  # back to tuple
(1, 2, 3)

A list comprehension can be use to convert a tuple of tuples to a list of lists:

>>> level1 = (
...      (1,1,1,1,1,1),
...      (1,0,0,0,0,1),
...      (1,0,0,0,0,1),
...      (1,0,0,0,0,1),
...      (1,0,0,0,0,1),
...      (1,1,1,1,1,1))
>>> level1_list = [[*row] for row in level1]
>>> level1_list
[[1, 1, 1, 1, 1, 1], 
 [1, 0, 0, 0, 0, 1], 
 [1, 0, 0, 0, 0, 1], 
 [1, 0, 0, 0, 0, 1], 
 [1, 0, 0, 0, 0, 1], 
 [1, 1, 1, 1, 1, 1]]
>>> *((*row,) for row in level1_list),
((1, 1, 1, 1, 1, 1), 
 (1, 0, 0, 0, 0, 1), 
 (1, 0, 0, 0, 0, 1), 
 (1, 0, 0, 0, 0, 1), 
 (1, 0, 0, 0, 0, 1), 
 (1, 1, 1, 1, 1, 1))
>>> _ == level1
True

ERROR 2003 (HY000): Can't connect to MySQL server on localhost (10061)

This happened to me too! But I accidentally found out that execute the 'mysqld' command can solve your problem.

My SQL version is 5.7. Hope this works for you.

Convert JSON string to array of JSON objects in Javascript

Using jQuery:

var str = '{"id":1,"name":"Test1"},{"id":2,"name":"Test2"}';
var jsonObj = $.parseJSON('[' + str + ']');

jsonObj is your JSON object.

Django Reverse with arguments '()' and keyword arguments '{}' not found

The solution @miki725 is absolutely correct. Alternatively, if you would like to use the args attribute as opposed to kwargs, then you can simply modify your code as follows:

project_id = 4
reverse('edit_project', args=(project_id,))

An example of this can be found in the documentation. This essentially does the same thing, but the attributes are passed as arguments. Remember that any arguments that are passed need to be assigned a value before being reversed. Just use the correct namespace, which in this case is 'edit_project'.

input() error - NameError: name '...' is not defined

Here is an input function which is compatible with both Python 2.7 and Python 3+: (Slightly modified answer by @Hardian) to avoid UnboundLocalError: local variable 'input' referenced before assignment error

def input_compatible(prompt=None):
    try:
        input_func = raw_input
    except NameError:
        input_func = input
    return input_func(prompt)

Create a .txt file if doesn't exist, and if it does append a new line

When you start StreamWriter it's override the text was there before. You can use append property like so:

TextWriter t = new StreamWriter(path, true);

How to check if all inputs are not empty with jQuery

$('input').each(function() {
    if ($(this).val() != '') {
        console.log('all inputs filled');
    }
    else{
        console.log('theres an empty input');
        return false
    }
});

you might want to wrap this in a keyup function

How can I build for release/distribution on the Xcode 4?

To set the build configuration to Debug or Release, choose 'Edit Scheme' from the 'Product' menu.

Then you see a clear choice.

The Apple Transition Guide mentions a button at the top left of the Xcode screen, but I cannot see it in Xcode 4.3.

Are static class variables possible in Python?

If you are attempting to share a static variable for, by example, increasing it across other instances, something like this script works fine:

# -*- coding: utf-8 -*-
class Worker:
    id = 1

    def __init__(self):
        self.name = ''
        self.document = ''
        self.id = Worker.id
        Worker.id += 1

    def __str__(self):
        return u"{}.- {} {}".format(self.id, self.name, self.document).encode('utf8')


class Workers:
    def __init__(self):
        self.list = []

    def add(self, name, doc):
        worker = Worker()
        worker.name = name
        worker.document = doc
        self.list.append(worker)


if __name__ == "__main__":
    workers = Workers()
    for item in (('Fiona', '0009898'), ('Maria', '66328191'), ("Sandra", '2342184'), ('Elvira', '425872')):
        workers.add(item[0], item[1])
    for worker in workers.list:
        print(worker)
    print("next id: %i" % Worker.id)

How do I add an image to a JButton

public class ImageButton extends JButton {

    protected ImageButton(){
    }

    @Override
        public void paint(Graphics g) {
        Graphics2D g2 = (Graphics2D) g;
        Image img = Toolkit.getDefaultToolkit().getImage("water.bmp");

        g2.drawImage(img, 45, 35, this);
        g2.finalize();
    }
}

OR use this code

class MyButton extends JButton {

    Image image;
    ImageObserver imageObserver;


    MyButtonl(String filename) {
            super();
            ImageIcon icon = new ImageIcon(filename);
            image = icon.getImage();
            imageObserver = icon.getImageObserver();
        }

     public void paint( Graphics g ) {
            super.paint( g );
            g.drawImage(image,  0 , 0 , getWidth() , getHeight() , imageObserver);
        }
    }

Get just the filename from a path in a Bash script

$ source_file_filename_no_ext=${source_file%.*}
$ echo ${source_file_filename_no_ext##*/}

Set Google Chrome as the debugging browser in Visual Studio

To add something to this (cause I found it while searching on this problem, and my solution involved slightly more)...

If you don't have a "Browse with..." option for .aspx files (as I didn't in a MVC application), the easiest solution is to add a dummy HTML file, and right-click it to set the option as described in the answer. You can remove the file afterward.

The option is actually set in: C:\Documents and Settings[user]\Local Settings\Application Data\Microsoft\VisualStudio[version]\browser.xml

However, if you modify the file directly while VS is running, VS will overwrite it with your previous option on next run. Also, if you edit the default in VS you won't have to worry about getting the schema right, so the work-around dummy file is probably the easiest way.

Form submit with AJAX passing form data to PHP without page refresh

$(document).ready(function(){
$('#userForm').on('submit', function(e){
        e.preventDefault();
//I had an issue that the forms were submitted in geometrical progression after the next submit. 
// This solved the problem.
        e.stopImmediatePropagation();
    // show that something is loading
    $('#response').html("<b>Loading data...</b>");

    // Call ajax for pass data to other place
    $.ajax({
    type: 'POST',
    url: 'somephpfile.php',
    data: $(this).serialize() // getting filed value in serialize form
    })
    .done(function(data){ // if getting done then call.

    // show the response
    $('#response').html(data);

    })
    .fail(function() { // if fail then getting message

    // just in case posting your form failed
    alert( "Posting failed." );

    });

    // to prevent refreshing the whole page page
    return false;

    });

How to validate Google reCAPTCHA v3 on server side?

I'm not a fan of any of these solutions. I use this instead:

$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, "https://www.google.com/recaptcha/api/siteverify");
curl_setopt($ch, CURLOPT_HEADER, 0);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1); 
curl_setopt($ch, CURLOPT_POST, 1);
curl_setopt($ch, CURLOPT_POSTFIELDS, [
    'secret' => $privatekey,
    'response' => $_POST['g-recaptcha-response'],
    'remoteip' => $_SERVER['REMOTE_ADDR']
]);

$resp = json_decode(curl_exec($ch));
curl_close($ch);

if ($resp->success) {
    // Success
} else {
    // failure
}

I'd argue that this is superior because you ensure it is being POSTed to the server and it's not making an awkward 'file_get_contents' call. This is compatible with recaptcha 2.0 described here: https://developers.google.com/recaptcha/docs/verify

I find this cleaner. I see most solutions are file_get_contents, when I feel curl would suffice.

DataTable: Hide the Show Entries dropdown but keep the Search box

This is key answer to this post "bLengthChange": false, will hide the Entries Dropdown

Deprecated Gradle features were used in this build, making it incompatible with Gradle 5.0

It work for me in this issue in a project of react-native:

Deprecated Gradle features were used in this build, making it incompatible with Gradle 7.0.

244 actionable tasks: 2 executed, 242 up-to-date D8: Cannot fit requested classes in a single dex file (# fields: 67296 > 65536) com.android.builder.dexing.DexArchiveMergerException: Error while merging dex archives: The number of method references in a .dex file cannot exceed 64K. Learn how to resolve this issue at https://developer.android.com/tools/building/multidex.html ....

I Did this:

TypeScript static classes

I got the same use case today(31/07/2018) and found this to be a workaround. It is based on my research and it worked for me. Expectation - To achieve the following in TypeScript:

var myStaticClass = {
    property: 10,
    method: function(){} 
}

I did this:

//MyStaticMembers.ts
namespace MyStaticMembers {
        class MyStaticClass {
           static property: number = 10;
           static myMethod() {...}
        }
        export function Property(): number {
           return MyStaticClass.property;
        }
        export function Method(): void {
           return MyStaticClass.myMethod();
        }
     }

Hence we shall consume it as below:

//app.ts
/// <reference path="MyStaticMembers.ts" />
    console.log(MyStaticMembers.Property);
    MyStaticMembers.Method();

This worked for me. If anyone has other better suggestions please let us all hear it !!! Thanks...

Firebase FCM force onTokenRefresh() to be called

FirebaseMessaging.getInstance().getToken().addOnSuccessListener(new 
OnSuccessListener<String>() {
    @Override
    public void onSuccess(String newToken) {
        ....
    }
});

ERROR in ./node_modules/css-loader?

I tried both

npm rebuild node-sass

and

npm install --save node-sass

Later by seeing EACCESS, i checked the folder permission of /node_modules, which was not 777 permission

Then I gave

chmod -R 777 *

-R for recursively(setting the same permission not in the dir but also inside nested sub dir) * is for all files in current directory

What is file permission

To check for permission you can use

ls -l

If u don't know about it, first see here, then check the url

Every file and directory has permission of 'rwx'(read, write, execute). and if 'x' permission is not there, then you can not execture, if no 'w', you can not write into the file. if some thing is missiing it will show in place of r/w/x with '-'. So, if 'x' permission is not there, it will show like 'rw-'

And there will be 3 category of user Owner(who created the file/directory), Group(some people who shares same permission and user previlege), Others(general public)

So 1st letter is 'd'(if it is a directory) or '-'(if it is not a directory), followed by rwx for owner, followed by for group, followed by other

drwxrwxrwx

For example, for 'node_modules'directory I want to give permission to owner all permission and for rest only read, then it will be

drwxr--r--

And about the number assume for 'r/w/x' it is 1 and for '-' it is 0, 777, first 7 is for owner, followed by group, followed by other

Let's assume the permission is rwxr-xrw-

Now 'rwx' is like '111' and it's equivalent decimal is 1*2^2+1*2^1+1*2^0=7

Now 'r-x' is like '101' and it's equivalent decimal is 1*2^2+0*2^1+1*2^0=5

Now 'rw-' is like '110' and it's equivalent decimal is 1*2^2+1*2^1+0*2^0=6

So, it will be 756

Why does using from __future__ import print_function breaks Python2-style print?

First of all, from __future__ import print_function needs to be the first line of code in your script (aside from some exceptions mentioned below). Second of all, as other answers have said, you have to use print as a function now. That's the whole point of from __future__ import print_function; to bring the print function from Python 3 into Python 2.6+.

from __future__ import print_function

import sys, os, time

for x in range(0,10):
    print(x, sep=' ', end='')  # No need for sep here, but okay :)
    time.sleep(1)

__future__ statements need to be near the top of the file because they change fundamental things about the language, and so the compiler needs to know about them from the beginning. From the documentation:

A future statement is recognized and treated specially at compile time: Changes to the semantics of core constructs are often implemented by generating different code. It may even be the case that a new feature introduces new incompatible syntax (such as a new reserved word), in which case the compiler may need to parse the module differently. Such decisions cannot be pushed off until runtime.

The documentation also mentions that the only things that can precede a __future__ statement are the module docstring, comments, blank lines, and other future statements.

jQuery select2 get value of select tag?

If you are using ajax, you may want to get updated value of select right after the selection.

//Part 1

$(".element").select2(/*Your code*/)    

//Part 2 - continued 

$(".element").on("select2:select", function (e) { 
  var select_val = $(e.currentTarget).val();
  console.log(select_val)
});

Credits: Steven-Johnston

Twitter bootstrap scrollable table

Don't need the wrap it in a div...

CSS:

tr {
width: 100%;
display: inline-table;
table-layout: fixed;
}

table{
 height:300px;              // <-- Select the height of the table
 display: -moz-groupbox;    // Firefox Bad Effect
}
tbody{
  overflow-y: scroll;      
  height: 200px;            //  <-- Select the height of the body
  width: 100%;
  position: absolute;
}

Bootply : http://www.bootply.com/AgI8LpDugl

How to setup virtual environment for Python in VS Code?

  1. If your using vs code on mac, it's important to have your venv installed in the same directory as your workspace.

  2. In my case my venv was in a different directory( not in my project workspace) so a simple cut/copy-paste of my venv to the project workspace did the trick.

  3. As soon as your venv is copied to the project workspace, your vs code will pick that up and show a notification giving you an option to select venv as an interpreter.

In git, what is the difference between merge --squash and rebase?

Merge squash merges a tree (a sequence of commits) into a single commit. That is, it squashes all changes made in n commits into a single commit.

Rebasing is re-basing, that is, choosing a new base (parent commit) for a tree. Maybe the mercurial term for this is more clear: they call it transplant because it's just that: picking a new ground (parent commit, root) for a tree.

When doing an interactive rebase, you're given the option to either squash, pick, edit or skip the commits you are going to rebase.

Hope that was clear!

Current date and time - Default in MVC razor

Isn't this what default constructors are for?

class MyModel
{

    public MyModel()
    {
        this.ReturnDate = DateTime.Now;
    }

    public date ReturnDate {get; set;};

}

gcc/g++: "No such file or directory"

this works for me, sudo apt-get install libx11-dev

How do you detect the clearing of a "search" HTML5 input?

My solution is based on the onclick event, where I check the value of the input (make sure that it's not empty) on the exact time the event fires and then wait for 1 millisecond and check the value again; if it's empty then it means that the clear button have been clicked not just the input field.

Here's an example using a Vue function:

HTML

<input
  id="searchBar"
  class="form-input col-span-4"
  type="search"
  placeholder="Search..."
  @click="clearFilter($event)"
/>

JS

clearFilter: function ($event) {
  if (event.target.value !== "") {
    setTimeout(function () {
      if (document.getElementById("searchBar").value === "")
        console.log("Clear button is clicked!");
    }, 1);
  }
  console.log("Search bar is clicked but not the clear button.");
},

How to fix java.lang.UnsupportedClassVersionError: Unsupported major.minor version

  • If you use Maven, set your Java compile level. Open a command line and write java -version for your compile level:

    Enter image description here

  • If you use IntelliJ IDEA, select project ? File ? Settings ? Build Execution Deployment ? Compiler ? Java Compiler. Then change byte code as 1.7 like this image:

    Enter image description here

Using $_POST to get select option value from HTML

Use this way:

$selectOption = $_POST['taskOption'];

But it is always better to give values to your <option> tags.

<select name="taskOption">
  <option value="1">First</option>
  <option value="2">Second</option>
  <option value="3">Third</option>
</select>

How to get the connection String from a database

put below tag in web.config file in configuration node

 <connectionStrings>
<add name="NameOFConnectionString" connectionString="Data Source=Server;Initial Catalog=DatabaseName;User ID=User;Password=Pwd"
  providerName="System.Data.SqlClient" />

then you can use above connectionstring, e.g.

SqlConnection con = new SqlConnection();
            con.ConnectionString = ConfigurationManager.ConnectionStrings["NameOFConnectionString"].ToString();

Why don’t my SVG images scale using the CSS "width" property?

The transform CSS property lets you rotate, scale, skew, or translate an element.

So you can easily use the transform: scale(2.5); option to scale 2.5 times for example.

Binding a generic list to a repeater - ASP.NET

You should use ToList() method. (Don't forget about System.Linq namespace)

ex.:

IList<Model> models = Builder<Model>.CreateListOfSize(10).Build();
List<Model> lstMOdels = models.ToList();

calling java methods in javascript code

Java is a server side language, whereas javascript is a client side language. Both cannot communicate. If you have setup some server side script using Java you could use AJAX on the client in order to send an asynchronous request to it and thus invoke any possible Java functions. For example if you use jQuery as js framework you may take a look at the $.ajax() method. Or if you wanted to do it using plain javascript, here's a tutorial.

Set a cookie to never expire

You can't but what if you set expire time to now + 100 years ?

How can I deserialize JSON to a simple Dictionary<string,string> in ASP.NET?

I did discover .NET has a built in way to cast the JSON string into a Dictionary<String, Object> via the System.Web.Script.Serialization.JavaScriptSerializer type in the 3.5 System.Web.Extensions assembly. Use the method DeserializeObject(String).

I stumbled upon this when doing an ajax post (via jquery) of content type 'application/json' to a static .net Page Method and saw that the method (which had a single parameter of type Object) magically received this Dictionary.

What is the best way to conditionally apply attributes in AngularJS?

To get an attribute to show a specific value based on a boolean check, or be omitted entirely if the boolean check failed, I used the following:

ng-attr-example="{{params.type == 'test' ? 'itWasTest' : undefined }}"

Example usage:

<div ng-attr-class="{{params.type == 'test' ? 'itWasTest' : undefined }}">

Would output <div class="itWasTest"> or <div> based on the value of params.type

server certificate verification failed. CAfile: /etc/ssl/certs/ca-certificates.crt CRLfile: none

The first thing you should check for is the file permission of /etc/ssl and /etc/ssl/certs.

I made the mistake of dropping file permissions (or blowing away the SSL rm -rf /etc/ssl/* directories) when using ssl-cert group name/ID while working on my Certificate Authority Management Tool.

It was then that I noticed the exact same error message for wget and curl CLI browser tools:

server certificate verification failed. CAfile: /etc/ssl/certs/ca-certificates.crt CRLfile: none

Once I brought the /etc/ssl and /etc/ssl/cert directories' file permission up to o+rx-w, those CLI browser tools started to breath a bit easier:

mkdir -p /etc/ssl/certs
chmod u+rwx,go+rx /etc/ssl /etc/ssl/certs

I also had to recreate Java subdirectory and reconstruct the Trusted CA certificate directories:

mkdir /etc/ssl/certs/java
chmod u+rwx,go+rx /etc/ssl/certs/java
update-ca-certificates

and the coast was clear.

How to loop through an array of objects in swift

Your userPhotos array is option-typed, you should retrieve the actual underlying object with ! (if you want an error in case the object isn't there) or ? (if you want to receive nil in url):

let userPhotos = currentUser?.photos

for var i = 0; i < userPhotos!.count ; ++i {
    let url = userPhotos![i].url
}

But to preserve safe nil handling, you better use functional approach, for instance, with map, like this:

let urls = userPhotos?.map{ $0.url }

IIS 500.19 with 0x80070005 The requested page cannot be accessed because the related configuration data for the page is invalid error

On the IIS 7.5 error page you get click on 'View more Information' at the bottom of the page and in this case it will take you to the following Microsoft link:

http://support.microsoft.com/kb/942055

The 0x80070005 Error Code seems to be permissions related and following the steps in Resolution 2, Method 2 assigning the correct accounts with permissions on relevant folders should fix it - I spent 3 days looking for a solution until I came across it, worked straight after.

How to create a link to another PHP page

Html a tag

Link in html

 <a href="index1.php">page1</a>
 <a href="page2.php">page2</a>

Html in php

echo ' <a href="index1.php">page1</a>';
echo '<a href="page2.php">page2</a>';

Delimiter must not be alphanumeric or backslash and preg_match

You need a delimiter for your pattern. It should be added at the start and end of the pattern like so:

$pattern = "/My name is '(.*)' and im fine/";  // With / as a delimeter 

Cosine Similarity between 2 Number Lists

Using numpy compare one list of numbers to multiple lists(matrix):

def cosine_similarity(vector,matrix):
   return ( np.sum(vector*matrix,axis=1) / ( np.sqrt(np.sum(matrix**2,axis=1)) * np.sqrt(np.sum(vector**2)) ) )[::-1]

Adding days to a date in Java

java.time

With the Java 8 Date and Time API you can use the LocalDate class.

LocalDate.now().plusDays(nrOfDays)

See the Oracle Tutorial.

:first-child not working as expected

you can also use

.detail_container h1:nth-of-type(1)

By changing the number 1 by any other number you can select any other h1 item.

error MSB6006: "cmd.exe" exited with code 1

I also faced similar issue.

My source path had one directory with 'space' (D:/source 2012). I resolved this by removing the space (D:/source2012).

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

You will notice a big change when selecting options if you type in "java -version" after doing so. So if you run update-alternatives --config java and select option 3, you will be using the Sun implementation.
Also, with regards to auto vs manual mode, making a selection should take it out of auto mode per this page stating:

When using the --config option, alternatives will list all of the choices for the link group of which given name is the master link. You will then be prompted for which of the choices to use for the link group. Once you make a change, the link group will no longer be in auto mode. You will need to use the --auto option in order to return to the automatic state.

And I believe auto mode is set when you install the first/only JRE/JDK.

Redirect pages in JSP?

Just define the target page in the action attribute of the <form> containing the submit button.

So, in page1.jsp:

<form action="page2.jsp">
    <input type="submit">
</form>

Unrelated to the problem, a JSP is not the best place to do business stuff, if you need to do any. Consider learning servlets.

ViewPager and fragments — what's the right way to store fragment's state?

To get the fragments after orientation change you have to use the .getTag().

    getSupportFragmentManager().findFragmentByTag("android:switcher:" + viewPagerId + ":" + positionOfItemInViewPager)

For a bit more handling i wrote my own ArrayList for my PageAdapter to get the fragment by viewPagerId and the FragmentClass at any Position:

public class MyPageAdapter extends FragmentPagerAdapter implements Serializable {
private final String logTAG = MyPageAdapter.class.getName() + ".";

private ArrayList<MyPageBuilder> fragmentPages;

public MyPageAdapter(FragmentManager fm, ArrayList<MyPageBuilder> fragments) {
    super(fm);
    fragmentPages = fragments;
}

@Override
public Fragment getItem(int position) {
    return this.fragmentPages.get(position).getFragment();
}

@Override
public CharSequence getPageTitle(int position) {
    return this.fragmentPages.get(position).getPageTitle();
}

@Override
public int getCount() {
    return this.fragmentPages.size();
}


public int getItemPosition(Object object) {
    //benötigt, damit bei notifyDataSetChanged alle Fragemnts refrehsed werden

    Log.d(logTAG, object.getClass().getName());
    return POSITION_NONE;
}

public Fragment getFragment(int position) {
    return getItem(position);
}

public String getTag(int position, int viewPagerId) {
    //getSupportFragmentManager().findFragmentByTag("android:switcher:" + R.id.shares_detail_activity_viewpager + ":" + myViewPager.getCurrentItem())

    return "android:switcher:" + viewPagerId + ":" + position;
}

public MyPageBuilder getPageBuilder(String pageTitle, int icon, int selectedIcon, Fragment frag) {
    return new MyPageBuilder(pageTitle, icon, selectedIcon, frag);
}


public static class MyPageBuilder {

    private Fragment fragment;

    public Fragment getFragment() {
        return fragment;
    }

    public void setFragment(Fragment fragment) {
        this.fragment = fragment;
    }

    private String pageTitle;

    public String getPageTitle() {
        return pageTitle;
    }

    public void setPageTitle(String pageTitle) {
        this.pageTitle = pageTitle;
    }

    private int icon;

    public int getIconUnselected() {
        return icon;
    }

    public void setIconUnselected(int iconUnselected) {
        this.icon = iconUnselected;
    }

    private int iconSelected;

    public int getIconSelected() {
        return iconSelected;
    }

    public void setIconSelected(int iconSelected) {
        this.iconSelected = iconSelected;
    }

    public MyPageBuilder(String pageTitle, int icon, int selectedIcon, Fragment frag) {
        this.pageTitle = pageTitle;
        this.icon = icon;
        this.iconSelected = selectedIcon;
        this.fragment = frag;
    }
}

public static class MyPageArrayList extends ArrayList<MyPageBuilder> {
    private final String logTAG = MyPageArrayList.class.getName() + ".";

    public MyPageBuilder get(Class cls) {
        // Fragment über FragmentClass holen
        for (MyPageBuilder item : this) {
            if (item.fragment.getClass().getName().equalsIgnoreCase(cls.getName())) {
                return super.get(indexOf(item));
            }
        }
        return null;
    }

    public String getTag(int viewPagerId, Class cls) {
        // Tag des Fragment unabhängig vom State z.B. nach bei Orientation change
        for (MyPageBuilder item : this) {
            if (item.fragment.getClass().getName().equalsIgnoreCase(cls.getName())) {
                return "android:switcher:" + viewPagerId + ":" + indexOf(item);
            }
        }
        return null;
    }
}

So just create a MyPageArrayList with the fragments:

    myFragPages = new MyPageAdapter.MyPageArrayList();

    myFragPages.add(new MyPageAdapter.MyPageBuilder(
            getString(R.string.widget_config_data_frag),
            R.drawable.ic_sd_storage_24dp,
            R.drawable.ic_sd_storage_selected_24dp,
            new WidgetDataFrag()));

    myFragPages.add(new MyPageAdapter.MyPageBuilder(
            getString(R.string.widget_config_color_frag),
            R.drawable.ic_color_24dp,
            R.drawable.ic_color_selected_24dp,
            new WidgetColorFrag()));

    myFragPages.add(new MyPageAdapter.MyPageBuilder(
            getString(R.string.widget_config_textsize_frag),
            R.drawable.ic_settings_widget_24dp,
            R.drawable.ic_settings_selected_24dp,
            new WidgetTextSizeFrag()));

and add them to the viewPager:

    mAdapter = new MyPageAdapter(getSupportFragmentManager(), myFragPages);
    myViewPager.setAdapter(mAdapter);

after this you can get after orientation change the correct fragment by using its class:

        WidgetDataFrag dataFragment = (WidgetDataFrag) getSupportFragmentManager()
            .findFragmentByTag(myFragPages.getTag(myViewPager.getId(), WidgetDataFrag.class));

What does --net=host option in Docker command really do?

  1. you can create your own new network like --net="anyname"
  2. this is done to isolate the services from different container.
  3. suppose the same service are running in different containers, but the port mapping remains same, the first container starts well , but the same service from second container will fail. so to avoid this, either change the port mappings or create a network.

WMI "installed" query different from add/remove programs list?

I have been using Inno Setup for an installer. I'm using 64-bit Windows 7 only. I'm finding that registry entries are being written to

HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\Windows\CurrentVersion\Uninstall

I haven't yet figured out how to get this list to be reported by WMI (although the program is listed as installed in Programs and Features). If I figure it out, I'll try to remember to report back here.

UPDATE:

Entries for 32-bit programs installed on a 64-bit machine go in that registry location. There's more written here:

http://mdb-blog.blogspot.com/2010/09/c-check-if-programapplication-is.html

See my comment that describes 32-bit vs 64-bit behavior in that same post here:

http://mdb-blog.blogspot.com/2010/09/c-check-if-programapplication-is.html?showComment=1300402090679#c861009270784046894

Unfortunately, there doesn't seem to be a way to get WMI to list all programs from the add/remove programs list (aka Programs and Features in Windows 7, not sure about Vista). My current code has dropped WMI in favor of using the registry. The code itself to interrogate the registry is even easier than using WMI. Sample code is in the above link.

test if display = none

Use like this:

if( $('#foo').is(':visible') ) {
    // it's visible, do something
}
else {
    // it's not visible so do something else
}

Hope it helps!

Reorder / reset auto increment primary key

for InnoDB, do this (this will remove all records from a table, make a bakcup first):

SET @OLD_CHARACTER_SET_RESULTS=@@CHARACTER_SET_RESULTS ;
SET @OLD_COLLATION_CONNECTION=@@COLLATION_CONNECTION ;
SET NAMES utf8 ;
SET @OLD_UNIQUE_CHECKS=@@UNIQUE_CHECKS, UNIQUE_CHECKS=0 ;
SET @OLD_FOREIGN_KEY_CHECKS=@@FOREIGN_KEY_CHECKS, FOREIGN_KEY_CHECKS=0 ;
SET @OLD_SQL_MODE=@@SQL_MODE, SQL_MODE='NO_AUTO_VALUE_ON_ZERO' ;
SET @OLD_SQL_NOTES=@@SQL_NOTES, SQL_NOTES=0 ;
/* ================================================= */

drop table tablename;
CREATE TABLE `tablename` (
   table structure here!

) ENGINE=InnoDB AUTO_INCREMENT=  ai number to reset  DEFAULT CHARSET= char set here;



/* ================================================= */
SET SQL_MODE=@OLD_SQL_MODE ;
SET FOREIGN_KEY_CHECKS=@OLD_FOREIGN_KEY_CHECKS ;
SET UNIQUE_CHECKS=@OLD_UNIQUE_CHECKS ;
SET CHARACTER_SET_CLIENT=@OLD_CHARACTER_SET_CLIENT ;
SET CHARACTER_SET_RESULTS=@OLD_CHARACTER_SET_RESULTS ;
SET COLLATION_CONNECTION=@OLD_COLLATION_CONNECTION ;
SET SQL_NOTES=@OLD_SQL_NOTES ;

%matplotlib line magic causes SyntaxError in Python script

There are several reasons as to why this wouldn't work.

It is possible that matplotlib is not properly installed. have you tried running:

conda install matplotlib

If that doesn't work, look at your %PATH% environment variable, does it contain your libraries and python paths?

Similar problem on github anaconda

event Action<> vs event EventHandler<>

I realize that this question is over 10 years old, but it appears to me that not only has the most obvious answer not been addressed, but that maybe its not really clear from the question a good understanding of what goes on under the covers. In addition, there are other questions about late binding and what that means with regards to delegates and lambdas (more on that later).

First to address the 800 lb elephant/gorilla in the room, when to choose event vs Action<T>/Func<T>:

  • Use a lambda to execute one statement or method. Use event when you want more of a pub/sub model with multiple statements/lambdas/functions that will execute (this is a major difference right off the bat).
  • Use a lambda when you want to compile statements/functions to expression trees. Use delegates/events when you want to participate in more traditional late binding such as used in reflection and COM interop.

As an example of an event, lets wire up a simple and 'standard' set of events using a small console application as follows:

public delegate void FireEvent(int num);

public delegate void FireNiceEvent(object sender, SomeStandardArgs args);

public class SomeStandardArgs : EventArgs
{
    public SomeStandardArgs(string id)
    {
        ID = id;
    }

    public string ID { get; set; }
}

class Program
{
    public static event FireEvent OnFireEvent;

    public static event FireNiceEvent OnFireNiceEvent;


    static void Main(string[] args)
    {
        OnFireEvent += SomeSimpleEvent1;
        OnFireEvent += SomeSimpleEvent2;

        OnFireNiceEvent += SomeStandardEvent1;
        OnFireNiceEvent += SomeStandardEvent2;


        Console.WriteLine("Firing events.....");
        OnFireEvent?.Invoke(3);
        OnFireNiceEvent?.Invoke(null, new SomeStandardArgs("Fred"));

        //Console.WriteLine($"{HeightSensorTypes.Keyence_IL030}:{(int)HeightSensorTypes.Keyence_IL030}");
        Console.ReadLine();
    }

    private static void SomeSimpleEvent1(int num)
    {
        Console.WriteLine($"{nameof(SomeSimpleEvent1)}:{num}");
    }
    private static void SomeSimpleEvent2(int num)
    {
        Console.WriteLine($"{nameof(SomeSimpleEvent2)}:{num}");
    }

    private static void SomeStandardEvent1(object sender, SomeStandardArgs args)
    {

        Console.WriteLine($"{nameof(SomeStandardEvent1)}:{args.ID}");
    }
    private static void SomeStandardEvent2(object sender, SomeStandardArgs args)
    {
        Console.WriteLine($"{nameof(SomeStandardEvent2)}:{args.ID}");
    }
}

The output will look as follows:

enter image description here

If you did the same with Action<int> or Action<object, SomeStandardArgs>, you would only see SomeSimpleEvent2 and SomeStandardEvent2.

So whats going on inside of event?

If we expand out FireNiceEvent, the compiler is actually generating the following (I have omitted some details with respect to thread synchronization that isn't relevant to this discussion):

   private EventHandler<SomeStandardArgs> _OnFireNiceEvent;

    public void add_OnFireNiceEvent(EventHandler<SomeStandardArgs> handler)
    {
        Delegate.Combine(_OnFireNiceEvent, handler);
    }

    public void remove_OnFireNiceEvent(EventHandler<SomeStandardArgs> handler)
    {
        Delegate.Remove(_OnFireNiceEvent, handler);
    }

    public event EventHandler<SomeStandardArgs> OnFireNiceEvent
    {
        add
        {
            add_OnFireNiceEvent(value)
        }
        remove
        {
            remove_OnFireNiceEvent(value)

        }
    }

The compiler generates a private delegate variable which is not visible to the class namespace in which it is generated. That delegate is what is used for subscription management and late binding participation, and the public facing interface is the familiar += and -= operators we have all come to know and love : )

You can customize the code for the add/remove handlers by changing the scope of the FireNiceEvent delegate to protected. This now allows developers to add custom hooks to the hooks, such as logging or security hooks. This really makes for some very powerful features that now allows for customized accessibility to subscription based on user roles, etc. Can you do that with lambdas? (Actually you can by custom compiling expression trees, but that's beyond the scope of this response).

To address a couple of points from some of the responses here:

  • There really is no difference in the 'brittleness' between changing the args list in Action<T> and changing the properties in a class derived from EventArgs. Either will not only require a compile change, they will both change a public interface and will require versioning. No difference.

  • With respect to which is an industry standard, that depends on where this is being used and why. Action<T> and such is often used in IoC and DI, and event is often used in message routing such as GUI and MQ type frameworks. Note that I said often, not always.

  • Delegates have different lifetimes than lambdas. One also has to be aware of capture... not just with closure, but also with the notion of 'look what the cat dragged in'. This does affect memory footprint/lifetime as well as management a.k.a. leaks.

One more thing, something I referenced earlier... the notion of late binding. You will often see this when using framework like LINQ, regarding when a lambda becomes 'live'. That is very different than late binding of a delegate, which can happen more than once (i.e. the lambda is always there, but binding occurs on demand as often as is needed), as opposed to a lambda, which once it occurs, its done -- the magic is gone, and the method(s)/property(ies) will always bind. Something to keep in mind.

Set color of text in a Textbox/Label to Red and make it bold in asp.net C#

TextBox1.ForeColor = Color.Red;
TextBox1.Font.Bold = True;

Or this can be done using a CssClass (recommended):

.highlight
{
  color:red;
  font-weight:bold;
}

TextBox1.CssClass = "highlight";

Or the styles can be added inline:

TextBox1.Attributes["style"] = "color:red; font-weight:bold;";

How to call two methods on button's onclick method in HTML or JavaScript?

<input type="button" onclick="functionA();functionB();" />

function functionA()
{

}

function functionB()
{

}

ReactJS - How to use comments?

{ 
    // any valid js expression
}

If you wonder why does it work? it's because everything that's inside curly braces { } is a javascript expression,

so this is fine as well:

{ /*
         yet another js expression
*/ }

How to add label in chart.js for pie chart

Use ChartNew.js instead of Chart.js

...

So, I have re-worked Chart.js. Most of the changes, are associated to requests in "GitHub" issues of Chart.js.

And here is a sample http://jsbin.com/lakiyu/2/edit

var newopts = {
    inGraphDataShow: true,
    inGraphDataRadiusPosition: 2,
    inGraphDataFontColor: 'white'
}
var pieData = [
    {
        value: 30,
        color: "#F38630",
    },
    {
       value: 30,
       color: "#F34353",
    },
    {
        value: 30,
        color: "#F34353",
    }
]
var pieCtx = document.getElementById('pieChart').getContext('2d');
new Chart(pieCtx).Pie(pieData, newopts);

It even provides a GUI editor http://charts.livegap.com/

So sweet.

Get PostGIS version

Since some of the functions depend on other libraries like GEOS and proj4 you might want to get their versions too. Then use:

SELECT PostGIS_full_version();

How to open the second form?

//To open the form

Form2 form2 = new Form2();

form2.Show();
// And to close
form2.Close();

Hope this helps

How to add reference to a method parameter in javadoc?

I guess you could write your own doclet or taglet to support this behaviour.

Taglet Overview

Doclet Overview

Capitalize the first letter of both words in a two word string

Match a regular expression that starts at the beginning ^ or after a space [[:space:]] and is followed by an alphabetical character [[:alpha:]]. Globally (the g in gsub) replace all such occurrences with the matched beginning or space and the upper-case version of the matched alphabetical character, \\1\\U\\2. This has to be done with perl-style regular expression matching.

gsub("(^|[[:space:]])([[:alpha:]])", "\\1\\U\\2", name, perl=TRUE)
# [1] "Zip Code"    "State"       "Final Count"

In a little more detail for the replacement argument to gsub(), \\1 says 'use the part of x matching the first sub-expression', i.e., the part of x matching (^|[[:spacde:]]). Likewise, \\2 says use the part of x matching the second sub-expression ([[:alpha:]]). The \\U is syntax enabled by using perl=TRUE, and means to make the next character Upper-case. So for "Zip code", \\1 is "Zip", \\2 is "code", \\U\\2 is "Code", and \\1\\U\\2 is "Zip Code".

The ?regexp page is helpful for understanding regular expressions, ?gsub for putting things together.

Submitting form and pass data to controller method of type FileStreamResult

This is because you have specified the form method as GET

Change code in the view to this:

using (@Html.BeginForm("myMethod", "Home", FormMethod.Post, new { id = @item.JobId })){
}

Declare a dictionary inside a static class

The problem with your initial example was primarily due to the use of const rather than static; you can't create a non-null const reference in C#.

I believe this would also have worked:

public static class ErrorCode
{
    public static IDictionary<string, string> ErrorCodeDic
        = new Dictionary<string, string>()
            { {"1", "User name or password problem"} };
}

Also, as Y Low points out, adding readonly is a good idea as well, and none of the modifiers discussed here will prevent the dictionary itself from being modified.

PermissionError: [WinError 5] Access is denied python using moviepy to write gif

Solution on windows : restarted docker

On windows I used --use-container option during sam build

So, in order to fix stuck process, I've restarted docker

How to convert column with string type to int form in pyspark data frame?

from pyspark.sql.types import IntegerType
data_df = data_df.withColumn("Plays", data_df["Plays"].cast(IntegerType()))
data_df = data_df.withColumn("drafts", data_df["drafts"].cast(IntegerType()))

You can run loop for each column but this is the simplest way to convert string column into integer.

Query to check index on a table

Simply you can find index name and column names of a particular table using below command

SP_HELPINDEX 'tablename'

It work's for me

How to import functions from different js file in a Vue+webpack+vue-loader project

Say I want to import data into a component from src/mylib.js:

var test = {
  foo () { console.log('foo') },
  bar () { console.log('bar') },
  baz () { console.log('baz') }
}

export default test

In my .Vue file I simply imported test from src/mylib.js:

<script> 
  import test from '@/mylib'

  console.log(test.foo())
  ...
</script>

Verify if file exists or not in C#

In addition to using File.Exists(), you might be better off just trying to use the file and catching any exception that is thrown. The file can fail to open because of other things than not existing.

E: gnupg, gnupg2 and gnupg1 do not seem to be installed, but one of them is required for this operation

I have debian 9 and to fix this i used the new library as follows:

ln -s /usr/bin/gpgv /usr/bin/gnupg2

Execute php file from another php

Sounds like you're trying to execute the PHP code directly in your shell. Your shell doesn't speak PHP, so it interprets your PHP code as though it's in your shell's native language, as though you had literally run <?php at the command line.

Shell scripts usually start with a "shebang" line that tells the shell what program to use to interpret the file. Begin your file like this:

#!/usr/bin/env php
<?php
//Connection
function connection () {

Besides that, the string you're passing to exec doesn't make any sense. It starts with a slash all by itself, it uses too many periods in the path, and it has a stray right parenthesis.

Copy the contents of the command string and paste them at your command line. If it doesn't run there, then exec probably won't be able to run it, either.

Another option is to change the command you execute. Instead of running the script directly, run php and pass your script as an argument. Then you shouldn't need the shebang line.

exec('php name.php');

How to get all Windows service names starting with a common word?

sc queryex type= service state= all | find /i "NATION"
  • use /i for case insensitive search
  • the white space after type=is deliberate and required

Bootstrap modal in React.js

You can use the model from the react-bootstrap from link and it's basically a function based

function Example() {
  const [show, setShow] = useState(false);
  const handleClose = () => setShow(false);
  const handleShow = () => setShow(true);
  return (
    <>
      <Button variant="primary" onClick={handleShow}>
        Launch demo modal
      </Button>

      <Modal show={show} onHide={handleClose} animation={false}>
        <Modal.Header closeButton>
          <Modal.Title>Modal heading</Modal.Title>
        </Modal.Header>
        <Modal.Body>Woohoo, you're reading this text in a modal!</Modal.Body>
        <Modal.Footer>
          <Button variant="secondary" onClick={handleClose}>
            Close
          </Button>
          <Button variant="primary" onClick={handleClose}>
            Save Changes
          </Button>
        </Modal.Footer>
      </Modal>
    </>
  );
}

and You can convert it into the class component

import React, { Component } from "react";
import { Button, Modal } from "react-bootstrap";


export default class exampleextends Component {
  constructor(props) {
    super(props);
    this.state = {
      show: false,
      close: false,
    };
  } 
  render() {
    return (
      <div>
        <Button
          variant="none"
          onClick={() => this.setState({ show: true })}
        >
          Choose Profile
        </Button>
        <Modal
          show={this.state.show}
          animation={true}
          size="md" className="" shadow-lg border">
          <Modal.Header className="bg-danger text-white text-center py-1">
            <Modal.Title className="text-center">
              <h5>Delete</h5>
            </Modal.Title>
          </Modal.Header>
          <Modal.Body className="py-0 border">
            body   
          </Modal.Body>
<Modal.Footer className="py-1 d-flex justify-content-center">
              <div>
                <Button
                  variant="outline-dark" onClick={() => this.setState({ show: false })}>Cancel</Button>
              </div>
              <div>
                <Button variant="outline-danger" className="mx-2 px-3">Delete</Button>
              </div>
            </Modal.Footer>
        </Modal>
      </div>
    );
  }
}

MVC 4 @Scripts "does not exist"

That has an obvious solution. I had the same problem later. Not related to Assembly References or ... .It'll occur In hierarchy calling of MVC Partial views, when you have complicated page structures. So calling/rendering each part separately on each page (maybe a master page or partial) will cause to not see required parts of page like the bellow code :

@RenderSection("Scripts", required: false)

That simply forces page to find and render related section and in case of failure shows you an error message like you.

So I suggest you to trace your pages (like program trace) from master to all of its partials to Detect Dependencies. Maybe it be a terrible work, but no other choices available here.

Not that according to my experience, some conditional situations in programming causes not to show you the right error causes the problem.

Android button background color

Why not just use setBackgroundColor(getResources().getColor(R.color.holo_light_green))?

Edit: If you want to have something which looks more like an Android button you are going to want to create a gradient and set it as the background. For an example of this, you can check out this question.

float:left; vs display:inline; vs display:inline-block; vs display:table-cell;

I prefer inline-block, although float is also useful. Table-cell isn't rendered correctly by old IEs (neither does inline-block, but there's the zoom: 1; *display: inline hack that I use frequently). If you have children that have a smaller height than their parent, floats will bring them to the top, whereas inline-block will screw up sometimes.

Most of the time, the browser will interpret everything correctly, unless, of course, it's IE. You always have to check to make sure that IE doesn't suck-- for example, the table-cell concept.

In all reality, yes, it boils down to personal preference.

One technique you could use to get rid of white space would be to set a font-size of 0 to the parent, then give the font-size back to the children, although that's a hassle, and gross.

How to check if a function exists on a SQL database

Why not just:

IF object_id('YourFunctionName', 'FN') IS NOT NULL
BEGIN
    DROP FUNCTION [dbo].[YourFunctionName]
END
GO

The second argument of object_id is optional, but can help to identify the correct object. There are numerous possible values for this type argument, particularly:

  • FN : Scalar function
  • IF : Inline table-valued function
  • TF : Table-valued-function
  • FS : Assembly (CLR) scalar-function
  • FT : Assembly (CLR) table-valued function

How can I avoid getting this MySQL error Incorrect column specifier for column COLUMN NAME?

The auto_increment property only works for numeric columns (integer and floating point), not char columns:

CREATE TABLE discussion_topics (
    topic_id INT NOT NULL AUTO_INCREMENT,
    project_id char(36) NOT NULL,
    topic_subject VARCHAR(255) NOT NULL,
    topic_content TEXT default NULL,
    date_created DATETIME NOT NULL,
    date_last_post DATETIME NOT NULL,
    created_by_user_id char(36) NOT NULL,
    last_post_user_id char(36) NOT NULL,
    posts_count char(36) default NULL,
    PRIMARY KEY (topic_id)
) ENGINE=InnoDB DEFAULT CHARSET=utf8 AUTO_INCREMENT=1;

Difference between SET autocommit=1 and START TRANSACTION in mysql (Have I missed something?)

If you want to use rollback, then use start transaction and otherwise forget all those things,

By default, MySQL automatically commits the changes to the database.

To force MySQL not to commit these changes automatically, execute following:

SET autocommit = 0;
//OR    
SET autocommit = OFF

To enable the autocommit mode explicitly:

SET autocommit = 1;
//OR    
SET autocommit = ON;

Can a relative sitemap url be used in a robots.txt?

Good technical & logical question my dear friend. No in robots.txt file you can't go with relative URL of the sitemap; you need to go with the complete URL of the sitemap.

It's better to go with "sitemap: https://www.example.com/sitemap_index.xml"

In the above URL after the colon gives space. I also like to support Deepak.

What is the Python equivalent for a case/switch statement?

While the official docs are happy not to provide switch, I have seen a solution using dictionaries.

For example:

# define the function blocks
def zero():
    print "You typed zero.\n"

def sqr():
    print "n is a perfect square\n"

def even():
    print "n is an even number\n"

def prime():
    print "n is a prime number\n"

# map the inputs to the function blocks
options = {0 : zero,
           1 : sqr,
           4 : sqr,
           9 : sqr,
           2 : even,
           3 : prime,
           5 : prime,
           7 : prime,
}

Then the equivalent switch block is invoked:

options[num]()

This begins to fall apart if you heavily depend on fall through.

Converting Numpy Array to OpenCV Array

Your code can be fixed as follows:

import numpy as np, cv
vis = np.zeros((384, 836), np.float32)
h,w = vis.shape
vis2 = cv.CreateMat(h, w, cv.CV_32FC3)
vis0 = cv.fromarray(vis)
cv.CvtColor(vis0, vis2, cv.CV_GRAY2BGR)

Short explanation:

  1. np.uint32 data type is not supported by OpenCV (it supports uint8, int8, uint16, int16, int32, float32, float64)
  2. cv.CvtColor can't handle numpy arrays so both arguments has to be converted to OpenCV type. cv.fromarray do this conversion.
  3. Both arguments of cv.CvtColor must have the same depth. So I've changed source type to 32bit float to match the ddestination.

Also I recommend you use newer version of OpenCV python API because it uses numpy arrays as primary data type:

import numpy as np, cv2
vis = np.zeros((384, 836), np.float32)
vis2 = cv2.cvtColor(vis, cv2.COLOR_GRAY2BGR)

android.app.Application cannot be cast to android.app.Activity

You can also try this one.

override fun registerWith( registry: PluginRegistry) {
        GeneratedPluginRegistrant.registerWith(registry as FlutterEngine)       
    //registry.registrarFor("io.flutter.plugins.firebasemessaging.FirebaseMessagingPlugin")
    }

I think this one is far better solution than creating a new class.

Module AppRegistry is not registered callable module (calling runApplication)

Need to replace

.setJSMainModulePath("index") with .setJSMainModulePath("index.android")

How to loop through all elements of a form jQuery

What happens, if you do this way:-

$('#new_user_form input, #new_user_form select').each(function(key, value) {

Refer LIVE DEMO

Setting the default active profile in Spring-boot

Currently using Maven + Spring Boot. Our solution was the following:

application.properties

#spring.profiles.active= # comment_out or remove

securityConfig.java

@Value(${spring.profiles.active:[default_profile_name]}")
private String ACTIVE_PROFILE_NAME;

Credit starts with MartinMlima. Similar answer provided here:

How do you get current active/default Environment profile programmatically in Spring?

Removing the first 3 characters from a string

Just use substring: "apple".substring(3); will return le

Accessing UI (Main) Thread safely in WPF

Use [Dispatcher.Invoke(DispatcherPriority, Delegate)] to change the UI from another thread or from background.

Step 1. Use the following namespaces

using System.Windows;
using System.Threading;
using System.Windows.Threading;

Step 2. Put the following line where you need to update UI

Application.Current.Dispatcher.Invoke(DispatcherPriority.Background, new ThreadStart(delegate
{
    //Update UI here
}));

Syntax

[BrowsableAttribute(false)]
public object Invoke(
  DispatcherPriority priority,
  Delegate method
)

Parameters

priority

Type: System.Windows.Threading.DispatcherPriority

The priority, relative to the other pending operations in the Dispatcher event queue, the specified method is invoked.

method

Type: System.Delegate

A delegate to a method that takes no arguments, which is pushed onto the Dispatcher event queue.

Return Value

Type: System.Object

The return value from the delegate being invoked or null if the delegate has no return value.

Version Information

Available since .NET Framework 3.0

How can I convert a string to a number in Perl?

You don't need to convert it at all:

% perl -e 'print "5.45" + 0.1;'
5.55

PHP : send mail in localhost

You will need to install a local mailserver in order to do this. If you want to send it to external e-mail addresses, it might end up in unwanted e-mails or it may not arrive at all.

A good mailserver which I use (I use it on Linux, but it's also available for Windows) is Axigen: http://www.axigen.com/mail-server/download/

You might need some experience with mailservers to install it, but once it works, you can do anything you want with it.

How to easily import multiple sql files into a MySQL database?

Just type below command on your command prompt & it will bind all sql file into single sql file,

c:/xampp/mysql/bin/sql/ type *.sql > OneFile.sql;

Add UIPickerView & a Button in Action sheet - How?

I liked the approach taken by Wayfarer and flexaddicted, but found (like aZtral) that it did not work as the backgroundTapButton was the only element that was responding to user interaction. This led me to put all three of his subviews: _picker, _pickerToolbar and backgroundTapButton inside a containing view (popup) which was then animated on and off the screen. I also needed a Cancel button on the _pickerToolbar. Here are the relevant code elements for the popup view (you need to supply your own picker data source and delegate methods).

#define DURATION            0.4
#define PICKERHEIGHT        162.0
#define TOOLBARHEIGHT       44.0

@interface ViewController ()
@property (nonatomic, strong) UIView        *popup;
@property (nonatomic, strong) UIPickerView  *picker;
@property (nonatomic, strong) UIToolbar     *pickerToolbar;
@property (nonatomic, strong) UIButton      *backgroundTapButton;
@end

-(void)viewDidLoad {
    // These are ivars for convenience
    rect = self.view.bounds;
    topNavHeight = self.navigationController.navigationBar.frame.size.height;
    bottomNavHeight = self.navigationController.toolbar.frame.size.height;
    navHeights = topNavHeight + bottomNavHeight;
}

-(void)showPickerView:(id)sender {
    [self createPicker];
    [self createToolbar];

    // create view container
    _popup = [[UIView alloc] initWithFrame:CGRectMake(0.0, topNavHeight, rect.size.width, rect.size.height - navHeights)];
    // Initially put the centre off the bottom of the screen
    _popup.center = CGPointMake(rect.size.width / 2.0, rect.size.height + _popup.frame.size.height / 2.0);
    [_popup addSubview:_picker];
    [_popup insertSubview:_pickerToolbar aboveSubview:_picker];

    // Animate it moving up
    // This seems to work though I am not sure why I need to take off the topNavHeight
    CGFloat vertCentre = (_popup.frame.size.height - topNavHeight) / 2.0;

    [UIView animateWithDuration:DURATION animations:^{
        // move it to a new point in the middle of the screen
        [_popup setCenter:CGPointMake(rect.size.width / 2.0, vertCentre)];
    } completion:^(BOOL finished) {
        // When done, place an invisible 'button' on the view behind the picker,
        // so if the user "taps to dismiss" the picker, it will go away
        self.backgroundTapButton = [UIButton buttonWithType:UIButtonTypeCustom];
        _backgroundTapButton.frame = CGRectMake(0, 0, _popup.frame.size.width, _popup.frame.size.height);
        [_backgroundTapButton addTarget:self action:@selector(doneAction:) forControlEvents:UIControlEventTouchUpInside];
        [_popup insertSubview:_backgroundTapButton belowSubview:_picker];
        [self.view addSubview:_popup];
    }];
}

-(void)createPicker {
    // To use the default UIPickerView frame of 216px set frame to CGRectZero, but we want the 162px height one
    CGFloat     pickerStartY = rect.size.height - navHeights - PICKERHEIGHT;
    self.picker = [[UIPickerView alloc] initWithFrame:CGRectMake(0.0, pickerStartY, rect.size.width, PICKERHEIGHT)];
    _picker.dataSource = self;
    _picker.delegate = self;
    _picker.showsSelectionIndicator = YES;
    // Otherwise you can see the view underneath the picker
    _picker.backgroundColor = [UIColor whiteColor];
    _picker.alpha = 1.0f;
}

-(void)createToolbar {
    CGFloat     toolbarStartY = rect.size.height - navHeights - PICKERHEIGHT - TOOLBARHEIGHT;
    _pickerToolbar = [[UIToolbar alloc] initWithFrame:CGRectMake(0, toolbarStartY, rect.size.width, TOOLBARHEIGHT)];
    [_pickerToolbar sizeToFit];

    NSMutableArray *barItems = [[NSMutableArray alloc] init];
    UIBarButtonItem *cancelButton = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemCancel target:self action:@selector(cancelAction:)];
    [barItems addObject:cancelButton];

    // Flexible space to make the done button go on the right
    UIBarButtonItem *flexSpace = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemFlexibleSpace target:self action:nil];
    [barItems addObject:flexSpace];

    // The done button
    UIBarButtonItem *doneButton = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemDone target:self action:@selector(doneAction:)];
    [barItems addObject:doneButton];
    [_pickerToolbar setItems:barItems animated:YES];
}

// The method to process the picker, if we have hit done button
- (void)doneAction:(id)sender {
    [UIView animateWithDuration:DURATION animations:^{
        _popup.center = CGPointMake(rect.size.width / 2.0, rect.size.height + _popup.frame.size.height / 2.0);
    } completion:^(BOOL finished) { [self destroyPopup]; }];
    // Do something to process the returned value from your picker
}

// The method to process the picker, if we have hit cancel button
- (void)cancelAction:(id)sender {
    [UIView animateWithDuration:DURATION animations:^{
        _popup.center = CGPointMake(rect.size.width / 2.0, rect.size.height + _popup.frame.size.height / 2.0);
    } completion:^(BOOL finished) { [self destroyPopup]; }];
}

-(void)destroyPopup {
    [_picker removeFromSuperview];
    self.picker = nil;
    [_pickerToolbar removeFromSuperview];
    self.pickerToolbar = nil;
    [self.backgroundTapButton removeFromSuperview];
    self.backgroundTapButton = nil;
    [_popup removeFromSuperview];
    self.popup = nil;
}

MongoError: connect ECONNREFUSED 127.0.0.1:27017

I had below error:

Error: connect ECONNREFUSED 127.0.0.1:27017

In my case, this issue occurred since MongoDB is not installed at all.

The solution was to install MongoDB from below location:
https://www.mongodb.com/download-center/community

After installing the ECONNREFUSED error did not appear again.

Hope that helps.

Copy a git repo without history

You can limit the depth of the history while cloning:

--depth <depth>
Create a shallow clone with a history truncated to the specified 
number of revisions.

Use this if you want limited history, but still some.

copying all contents of folder to another folder using batch file?

RoboCopy did not work for me, and there are some good solutions here, but none explained the XCopy switches and what they do. Also you need quotes in case your path has spaces in it.

xcopy /i /e "C:\temp\folder 1" "C:\temp\folder 2"

Here is the documentation from Microsoft:

XCopy MS Documentation

/s: Specifies to include subdirectories. Excludes empty subdirectories
/e: Copies all subdirectories, even if they are empty
/i: specifies the destination is a folder (Otherwise it prompts you)

'setInterval' vs 'setTimeout'

setTimeout(expression, timeout); runs the code/function once after the timeout.

setInterval(expression, timeout); runs the code/function in intervals, with the length of the timeout between them.

Example:

var intervalID = setInterval(alert, 1000); // Will alert every second.
// clearInterval(intervalID); // Will clear the timer.

setTimeout(alert, 1000); // Will alert once, after a second.

How to handle static content in Spring MVC?

The URLRewrite is sort of a "hack" if you want to call it that. What it comes down to is, you're re-inventing the wheel; as there are already existing solutions. Another thing to remember is Http Server = Static content & App server = dynamic content (this is how they were designed). By delegating the appropriate responsibilities to each server you maximize efficiency... but now-a-days this is probably only a concern in a performance critical environments and something like Tomcat would most likely work well in both roles most of the time; but it is still something to keep in mind none the less.

Good font for code presentations?

I use DejaVu Sans Mono at Size 16.

UPDATE : I have switched to Envy Code R for coding and Anonymous Pro for terminal

Can there be an apostrophe in an email address?

Yes, according to RFC 3696 apostrophes are valid as long as they come before the @ symbol.

How do I make a LinearLayout scrollable?

You can implement it using View.scrollTo(..) also.

postDelayed(new Runnable() {
            public void run() {

                counter = (int) (counter + 10);
                handler.postDelayed(this, 100);

                    llParent.scrollTo(counter , 0);
                }

            }
        }, 1000L);

Substitute multiple whitespace with single whitespace in Python

A simple possibility (if you'd rather avoid REs) is

' '.join(mystring.split())

The split and join perform the task you're explicitly asking about -- plus, they also do the extra one that you don't talk about but is seen in your example, removing trailing spaces;-).

Getting list of parameter names inside python function

If you also want the values you can use the inspect module

import inspect

def func(a, b, c):
    frame = inspect.currentframe()
    args, _, _, values = inspect.getargvalues(frame)
    print 'function name "%s"' % inspect.getframeinfo(frame)[2]
    for i in args:
        print "    %s = %s" % (i, values[i])
    return [(i, values[i]) for i in args]

>>> func(1, 2, 3)
function name "func"
    a = 1
    b = 2
    c = 3
[('a', 1), ('b', 2), ('c', 3)]

Loop through an array of strings in Bash?

None of those answers include a counter...

#!/bin/bash
## declare an array variable
declare -a array=("one" "two" "three")

# get length of an array
arraylength=${#array[@]}

# use for loop to read all values and indexes
for (( i=1; i<${arraylength}+1; i++ ));
do
  echo $i " / " ${arraylength} " : " ${array[$i-1]}
done

Output:

1  /  3  :  one
2  /  3  :  two
3  /  3  :  three

Plugin with id 'com.google.gms.google-services' not found

In the app build.gradle dependency, you must add the following code

classpath 'com.google.gms:google-services:$last_version'

And then please check the Google Play Service SDK tools installing status.

How to merge two PDF files into one in Java?

Multiple pdf merged method using org.apache.pdfbox:

public void mergePDFFiles(List<File> files,
                          String mergedFileName) {
    try {
        PDFMergerUtility pdfmerger = new PDFMergerUtility();
        for (File file : files) {
            PDDocument document = PDDocument.load(file);
            pdfmerger.setDestinationFileName(mergedFileName);
            pdfmerger.addSource(file);
            pdfmerger.mergeDocuments(MemoryUsageSetting.setupTempFileOnly());
            document.close();
        }
    } catch (IOException e) {
        logger.error("Error to merge files. Error: " + e.getMessage());
    }
}

From main program, call mergePDFFiles method using list of files and target file name.

        String mergedFileName = "Merged.pdf";
        mergePDFFiles(files, mergedFileName);

After calling mergePDFFiles, load merged file

        File mergedFile = new File(mergedFileName);

Decoding base64 in batch

Here's a batch file, called base64encode.bat, that encodes base64.

@echo off
if not "%1" == "" goto :arg1exists
echo usage: base64encode input-file [output-file]
goto :eof
:arg1exists
set base64out=%2
if "%base64out%" == "" set base64out=con 
(
  set base64tmp=base64.tmp
  certutil -encode "%1" %base64tmp% > nul
  findstr /v /c:- %base64tmp%
  erase %base64tmp%
) > %base64out%

How can a windows service programmatically restart itself?

The first response to the question is the simplest solution: "Environment.Exit(1)" I am using this on Windows Server 2008 R2 and it works perfectly. The service stops itself, the O/S waits 1 minute, then restarts it.

Easy way to export multiple data.frame to multiple Excel worksheets

You can also use the openxlsx library to export multiple datasets to multiple sheets in a single workbook.The advantage of openxlsx over xlsx is that openxlsx removes the dependencies on java libraries.

Write a list of data.frames to individual worksheets using list names as worksheet names.

require(openxlsx)
list_of_datasets <- list("Name of DataSheet1" = dataframe1, "Name of Datasheet2" = dataframe2)
write.xlsx(list_of_datasets, file = "writeXLSX2.xlsx")

How do I handle too long index names in a Ruby on Rails ActiveRecord migration?

In PostgreSQL, the default limit is 63 characters. Because index names must be unique it's nice to have a little convention. I use (I tweaked the example to explain more complex constructions):

def change
  add_index :studies, [:professor_id, :user_id], name: :idx_study_professor_user
end

The normal index would have been:

:index_studies_on_professor_id_and_user_id

The logic would be:

  • index becomes idx
  • Singular table name
  • No joining words
  • No _id
  • Alphabetical order

Which usually does the job.

Interview Question: Merge two sorted singly linked lists without creating new nodes

I created only one dummy node at the beginning to save myself many 'if' conditions.

    public ListNode mergeTwoLists(ListNode l1, ListNode l2) {

        ListNode list1Cursor = l1;
        ListNode list2Cursor = l2;

        ListNode currentNode = new ListNode(-1); // Dummy node
        ListNode head = currentNode;

        while (list1Cursor != null && list2Cursor != null)
        {
            if (list1Cursor.val < list2Cursor.val) {
                currentNode.next = list1Cursor;
                list1Cursor = list1Cursor.next;
                currentNode = currentNode.next;
            } else {
                currentNode.next = list2Cursor;
                list2Cursor = list2Cursor.next;
                currentNode = currentNode.next;
            }
        }

        // Complete the rest
        while (list1Cursor != null) {
            currentNode.next = list1Cursor;
            currentNode = currentNode.next;
            list1Cursor = list1Cursor.next;
        }
        while (list2Cursor != null) {
            currentNode.next = list2Cursor;
            currentNode = currentNode.next;
            list2Cursor = list2Cursor.next;
        }

        return head.next;
    }

Center align with table-cell

This would be easier to do with flexbox. Using flexbox will let you not to specify the height of your content and can adjust automatically on the height it contains.

DEMO

here's the gist of the demo

.container{

  display: flex;
  height: 100%;
  justify-content: center;
  align-items: center;

}

html

<div class="container">
  <div class='content'> //you can size this anyway you want
    put anything you want here,
  </div>
</div>

enter image description here

How to implement my very own URI scheme on Android

Another alternate approach to Diego's is to use a library:

https://github.com/airbnb/DeepLinkDispatch

You can easily declare the URIs you'd like to handle and the parameters you'd like to extract through annotations on the Activity, like:

@DeepLink("path/to/what/i/want")
public class SomeActivity extends Activity {
  ...
}

As a plus, the query parameters will also be passed along to the Activity as well.

Expected BEGIN_ARRAY but was BEGIN_OBJECT at line 1 column 2

You state in the comments that the returned JSON is this:

{ 
  "dstOffset" : 3600, 
  "rawOffset" : 36000, 
  "status" : "OK", 
  "timeZoneId" : "Australia/Hobart", 
  "timeZoneName" : "Australian Eastern Daylight Time" 
}

You're telling Gson that you have an array of Post objects:

List<Post> postsList = Arrays.asList(gson.fromJson(reader,
                    Post[].class));

You don't. The JSON represents exactly one Post object, and Gson is telling you that.

Change your code to be:

Post post = gson.fromJson(reader, Post.class);

Best Practices for securing a REST API / web service

REST itself offers no security standards, but things like OAuth and SAML are rapidly becoming the standards in this space. However, authentication and authorization are only a small part of what you need to consider. Many of the known vulnerabilities relating to web applications apply very much to REST apis. You have to consider input validation, session cracking, inappropriate error messages, internal employee vulnerabilities and so on. It is a big subject.

What is the difference between exit(0) and exit(1) in C?

exit in the C language takes an integer representing an exit status.

Exit Success

Typically, an exit status of 0 is considered a success, or an intentional exit caused by the program's successful execution.

Exit Failure

An exit status of 1 is considered a failure, and most commonly means that the program had to exit for some reason, and was not able to successfully complete everything in the normal program flow.

Here's a GNU Resource talking about Exit Status.


As @Als has stated, two constants should be used in place of 0 and 1.

EXIT_SUCCESS is defined by the standard to be zero.

EXIT_FAILURE is not restricted by the standard to be one, but many systems do implement it as one.

Bootstrap 4: responsive sidebar menu to top navbar

If this isn't a good solution for any reason, please let me know. It worked fine for me.

What I did is to hide the Sidebar and then make appear the navbar with breakpoints

@media screen and (max-width: 771px) {
    #fixed-sidebar {
        display: none;
    }
    #navbar-superior {
        display: block !important;
    }
}

Storing integer values as constants in Enum manner in java

Well, you can't quite do it that way. PAGE.SIGN_CREATE will never return 1; it will return PAGE.SIGN_CREATE. That's the point of enumerated types.

However, if you're willing to add a few keystrokes, you can add fields to your enums, like this:


    public enum PAGE{
        SIGN_CREATE(0),
        SIGN_CREATE_BONUS(1),
        HOME_SCREEN(2),
        REGISTER_SCREEN(3);

        private final int value;

        PAGE(final int newValue) {
            value = newValue;
        }

        public int getValue() { return value; }
    }

And then you call PAGE.SIGN_CREATE.getValue() to get 0.

Color picker utility (color pipette) in Ubuntu

I recommend GPick:

sudo apt-get install gpick

Applications -> Graphics -> GPick

It has many more features than gcolor2 but is still extremely simple to use: click on one of the hex swatches, move your mouse around the screen over the colours you want to pick, then press the Space bar to add to your swatch list.

If that doesn't work, another way is to click-and-drag from the centre of the hexagon and release your mouse over the pixel that you want to sample. Then immediately hit Space to copy that color into the next swatch in rotation.

It also has a traditional colour picker (like gcolor2) in the bottom right-hand corner of the window to allow you to pick individual colours with magnification.

What does PHP keyword 'var' do?

var is used like public .if a varable is declared like this in a class var $a; if means its scope is public for the class. in simplea words var ~public

var $a;
public

Table Height 100% inside Div element

to set height of table to its container I must do:

1) set "position: absolute"

2) remove redundant contents of cells (!)

JAVA Unsupported major.minor version 51.0

The Java runtime you try to execute your program with is an earlier version than Java 7 which was the target you compile your program for.

For Ubuntu use

apt-get install openjdk-7-jdk

to get Java 7 as default. You may have to uninstall openjdk-6 first.

Using (Ana)conda within PyCharm

I know it's late, but I thought it would be nice to clarify things: PyCharm and Conda and pip work well together.

The short answer

Just manage Conda from the command line. PyCharm will automatically notice changes once they happen, just like it does with pip.

The long answer

Create a new Conda environment:

conda create --name foo pandas bokeh

This environment lives under conda_root/envs/foo. Your python interpreter is conda_root/envs/foo/bin/pythonX.X and your all your site-packages are in conda_root/envs/foo/lib/pythonX.X/site-packages. This is same directory structure as in a pip virtual environement. PyCharm sees no difference.

Now to activate your new environment from PyCharm go to file > settings > project > interpreter, select Add local in the project interpreter field (the little gear wheel) and hunt down your python interpreter. Congratulations! You now have a Conda environment with pandas and bokeh!

Now install more packages:

conda install scikit-learn

OK... go back to your interpreter in settings. Magically, PyCharm now sees scikit-learn!

And the reverse is also true, i.e. when you pip install another package in PyCharm, Conda will automatically notice. Say you've installed requests. Now list the Conda packages in your current environment:

conda list

The list now includes requests and Conda has correctly detected (3rd column) that it was installed with pip.

Conclusion

This is definitely good news for people like myself who are trying to get away from the pip/virtualenv installation problems when packages are not pure python.

NB: I run PyCharm pro edition 4.5.3 on Linux. For Windows users, replace in command line with in the GUI (and forward slashes with backslashes). There's no reason it shouldn't work for you too.

EDIT: PyCharm5 is out with Conda support! In the community edition too.

How can I remove item from querystring in asp.net using c#?

Try this ...

PropertyInfo isreadonly   =typeof(System.Collections.Specialized.NameValueCollection).GetProperty("IsReadOnly", BindingFlags.Instance | BindingFlags.NonPublic);    

isreadonly.SetValue(this.Request.QueryString, false, null);
this.Request.QueryString.Remove("foo");

Extract Google Drive zip from Google colab notebook

You can simply use this

!unzip file_location

Javascript - How to show escape characters in a string?

You have to escape the backslash, so try this:

str = "Hello\\nWorld";

Here are more escaped characters in Javascript.

How do I concatenate or merge arrays in Swift?

If you want the second array to be inserted after a particular index you can do this (as of Swift 2.2):

let index = 1
if 0 ... a.count ~= index {
     a[index..<index] = b[0..<b.count]
}
print(a) // [1.0, 4.0, 5.0, 6.0, 2.0, 3.0] 

MVC Razor Hidden input and passing values

A move from WebForms to MVC requires a complete sea-change in logic and brain processes. You're no longer interacting with the 'form' both server-side and client-side (and in fact even with WebForms you weren't interacting client-side). You've probably just mixed up a bit of thinking there, in that with WebForms and RUNAT="SERVER" you were merely interacting with the building of the Web page.

MVC is somewhat similar in that you have server-side code in constructing the model (the data you need to build what your user will see), but once you have built the HTML you need to appreciate that the link between the server and the user no longer exists. They have a page of HTML, that's it.

So the HTML you are building is read-only. You pass the model through to the Razor page, which will build HTML appropriate to that model.

If you want to have a hidden element which sets true or false depending on whether this is the first view or not you need a bool in your model, and set it to True in the Action if it's in response to a follow up. This could be done by having different actions depending on whether the request is [HttpGet] or [HttpPost] (if that's appropriate for how you set up your form: a GET request for the first visit and a POST request if submitting a form).

Alternatively the model could be set to True when it's created (which will be the first time you visit the page), but after you check the value as being True or False (since a bool defaults to False when it's instantiated). Then using:

@Html.HiddenFor(x => x.HiddenPostBack)

in your form, which will put a hidden True. When the form is posted back to your server the model will now have that value set to True.

It's hard to give much more advice than that as your question isn't specific as to why you want to do this. It's perhaps vital that you read a good book on moving to MVC from WebForms, such as Steve Sanderson's Pro ASP.NET MVC.

Java ArrayList clear() function

If you in any doubt, have a look at JDK source code

ArrayList.clear() source code:

public void clear() {
    modCount++;

    // Let gc do its work
    for (int i = 0; i < size; i++)
        elementData[i] = null;

    size = 0;
}

You will see that size is set to 0 so you start from 0 position.

Please note that when adding elements to ArrayList, the backend array is extended (i.e. array data is copied to bigger array if needed) in order to be able to add new items. When performing ArrayList.clear() you only remove references to array elements and sets size to 0, however, capacity stays as it was.

using stored procedure in entity framework

You need to create a model class that contains all stored procedure properties like below. Also because Entity Framework model class needs primary key, you can create a fake key by using Guid.

public class GetFunctionByID
{
    [Key]
    public Guid? GetFunctionByID { get; set; }

    // All the other properties.
}

then register the GetFunctionByID model class in your DbContext.

public class FunctionsContext : BaseContext<FunctionsContext>
{
    public DbSet<App_Functions> Functions { get; set; }
    public DbSet<GetFunctionByID> GetFunctionByIds {get;set;}
}

When you call your stored procedure, just see below:

var functionId = yourIdParameter;
var result =  db.Database.SqlQuery<GetFunctionByID>("GetFunctionByID @FunctionId", new SqlParameter("@FunctionId", functionId)).ToList());

How can I delay a :hover effect in CSS?

You can use transitions to delay the :hover effect you want, if the effect is CSS-based.

For example

div{
    transition: 0s background-color;
}

div:hover{
    background-color:red;    
    transition-delay:1s;
}

this will delay applying the the hover effects (background-color in this case) for one second.


Demo of delay on both hover on and off:

_x000D_
_x000D_
div{_x000D_
    display:inline-block;_x000D_
    padding:5px;_x000D_
    margin:10px;_x000D_
    border:1px solid #ccc;_x000D_
    transition: 0s background-color;_x000D_
    transition-delay:1s;_x000D_
}_x000D_
div:hover{_x000D_
    background-color:red;_x000D_
}
_x000D_
<div>delayed hover</div>
_x000D_
_x000D_
_x000D_

Demo of delay only on hover on:

_x000D_
_x000D_
div{_x000D_
    display:inline-block;_x000D_
    padding:5px;_x000D_
    margin:10px;_x000D_
    border:1px solid #ccc;_x000D_
    transition: 0s background-color;_x000D_
}_x000D_
div:hover{_x000D_
    background-color:red;    _x000D_
    transition-delay:1s;_x000D_
}
_x000D_
<div>delayed hover</div>
_x000D_
_x000D_
_x000D_


Vendor Specific Extentions for Transitions and W3C CSS3 transitions

Comparing two input values in a form validation with AngularJS

No need a function or a directive. Just compare their $modelValue from the view:

ng-show="formName.email.$modelValue !== formName.confirmEmail.$modelValue"

More detailed example:

<span ng-show="(formName.email.$modelValue !== formName.confirmEmail.$modelValue) 
                && formName.confirmEmail.$touched
                && !formName.confirmEmail.$error.required">Email does not match.</span>

Please note that the ConfirmEmail is outside the ViewModel; it's property of the $scope. It doesn't need to be submitted.

how to load CSS file into jsp

You can write like that. This is for whenever you change context path you don't need to modify your jsp file.

<link rel="stylesheet" href="${pageContext.request.contextPath}/css/styles.css" />

nodemon command is not recognized in terminal for node js server

  1. Install nodemon globally:

    C:\>npm install -g nodemon
    
  2. Get prefix:

    C:\>npm config get prefix
    

    You will get output like following in your console:

    C:\Users\Family\.node_modules_global
    

    Copy it.

  3. Set Path.
    Go to Advance System Settings → Environment Variable → Click New (Under User Variables) → Pop up form will be displayed → Pass the following values:

    variable name = path,
    variable value = Copy output from your console
    
  4. Now Run Nodemon:

    C:\>nodemon .
    

Why can't I duplicate a slice with `copy()`?

The builtin copy(dst, src) copies min(len(dst), len(src)) elements.

So if your dst is empty (len(dst) == 0), nothing will be copied.

Try tmp := make([]int, len(arr)) (Go Playground):

arr := []int{1, 2, 3}
tmp := make([]int, len(arr))
copy(tmp, arr)
fmt.Println(tmp)
fmt.Println(arr)

Output (as expected):

[1 2 3]
[1 2 3]

Unfortunately this is not documented in the builtin package, but it is documented in the Go Language Specification: Appending to and copying slices:

The number of elements copied is the minimum of len(src) and len(dst).

Edit:

Finally the documentation of copy() has been updated and it now contains the fact that the minimum length of source and destination will be copied:

Copy returns the number of elements copied, which will be the minimum of len(src) and len(dst).

Reset local repository branch to be just like remote repository HEAD

Provided that the remote repository is origin, and that you're interested in branch_name:

git fetch origin
git reset --hard origin/<branch_name>

Also, you go for reset the current branch of origin to HEAD.

git fetch origin
git reset --hard origin/HEAD

How it works:

git fetch origin downloads the latest from remote without trying to merge or rebase anything.

Then the git reset resets the <branch_name> branch to what you just fetched. The --hard option changes all the files in your working tree to match the files in origin/branch_name.

CSS Selector for <input type="?"

Sadly the other posters are correct that you're ...actually as corrected by kRON, you are ok with your IE7 and a strict doc, but most of us with IE6 requirements are reduced to JS or class references for this, but it is a CSS2 property, just one without sufficient support from IE^h^h browsers.

Out of completeness, the type selector is - similar to xpath - of the form [attribute=value] but many interesting variants exist. It will be quite powerful when it's available, good thing to keep in your head for IE8.

SQL Server 2000: How to exit a stored procedure?

Unless you specify a severity of 20 or higher, raiserror will not stop execution. See the MSDN documentation.

The normal workaround is to include a return after every raiserror:

if @whoops = 1
    begin
    raiserror('Whoops!', 18, 1)
    return -1
    end

How do I round a float upwards to the nearest int in C#?

Do I use one of these then cast to an Int?

Yes. There is no problem doing that. Decimals and doubles can represent integers exactly, so there will be no representation error. (You won't get a case, for instance, where Round returns 4.999... instead of 5.)

Moment Js UTC to Local Time

let utcTime = "2017-02-02 08:00:13.567";
var offset = moment().utcOffset();
var localText = moment.utc(utcTime).utcOffset(offset).format("L LT");

Try this JsFiddle

How do I populate a JComboBox with an ArrayList?

DefaultComboBoxModel dml= new DefaultComboBoxModel();
for (int i = 0; i < <ArrayList>.size(); i++) {
  dml.addElement(<ArrayList>.get(i).getField());
}

<ComboBoxName>.setModel(dml);

Understandable code.Edit<> with type as required.

How do I programmatically set the value of a select box element using JavaScript?

I compared the different methods:

Comparison of the different ways on how to set a value of a select with JS or jQuery

code:

$(function() {
    var oldT = new Date().getTime();
     var element = document.getElementById('myId');
    element.value = 4;
    console.error(new Date().getTime() - oldT);

    oldT = new Date().getTime();
    $("#myId option").filter(function() {
        return $(this).attr('value') == 4;
    }).attr('selected', true);
    console.error(new Date().getTime() - oldT);

    oldT = new Date().getTime();
    $("#myId").val("4");
    console.error(new Date().getTime() - oldT);
});

Output on a select with ~4000 elements:

  • 1 ms
  • 58 ms
  • 612 ms

With Firefox 10. Note: The only reason I did this test, was because jQuery performed super poorly on our list with ~2000 entries (they had longer texts between the options). We had roughly 2 s delay after a val()

Note as well: I am setting value depending on the real value, not the text value.

set dropdown value by text using jquery

For the exact match use

    $("#HowYouKnow option").filter(function(index) { return $(this).text() === "GOOGLE"; }).attr('selected', 'selected');

contains is going to select the last match which might not be exact.

How to update MySql timestamp column to current timestamp on PHP?

Use this query:

UPDATE `table` SET date_date=now();

Sample code can be:

<?php
$con = mysql_connect("localhost","peter","abc123");
if (!$con)
  {
  die('Could not connect: ' . mysql_error());
  }

mysql_select_db("my_db", $con);

mysql_query("UPDATE `table` SET date_date=now()");

mysql_close($con);
?>

If statement for strings in python?

Python is a case-sensitive language. All Python keywords are lowercase. Use if, not If.

Also, don't put a colon after the call to print(). Also, indent the print() and exit() calls, as Python uses indentation rather than brackets to represent code blocks.

And also, proceed = "y" or "Y" won't do what you want. Use proceed = "y" and if answer.lower() == proceed:, or something similar.

There's also the fact that your program will exit as long as the input value is not the single character "y" or "Y", which contradicts the prompting of "N" for the alternate case. Instead of your else clause there, use elif answer.lower() == info_incorrect:, with info_incorrect = "n" somewhere beforehand. Then just reprompt for the response or something if the input value was something else.


I'd recommend going through the tutorial in the Python documentation if you're having this much trouble the way you're learning now. http://docs.python.org/tutorial/index.html

CodeIgniter: Create new helper?

Create a file with the name of your helper in /application/helpers and add it to the autoload config file/load it manually.

E.g. place a file called user_helper.php in /application/helpers with this content:

<?php
  function pre($var)
  {
    echo '<pre>';
    if(is_array($var)) {
      print_r($var);
    } else {
      var_dump($var);
    }
    echo '</pre>';
  }
?> 

Now you can either load the helper via $this->load->helper(‘user’); or add it to application/config/autoload.php config.

Converting a String array into an int Array in java

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

public class array_test {

public static void main(String args[]) throws IOException{

BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
String line = br.readLine();

String[] s_array = line.split(" ");

/* Splitting the array of number separated by space into string array.*/

Integer [] a = new Integer[s_array.length];

/Creating the int array of size equals to string array./

    for(int i =0; i<a.length;i++)
    {
        a[i]= Integer.parseInt(s_array[i]);// Parsing from string to int

        System.out.println(a[i]);
    }

    // your integer array is ready to use.

}

}

Error:Unable to locate adb within SDK in Android Studio

Finally after several hours of investigation I think I have another solution for everyone having issues with AVD Manager "Unable to locate adb".

I know we have the setting for the SDK in File -> Settings -> Appearance & Behavior -> System Settings -> Android SDK. This it seems is not enough! It appears that Android Studio (at least the new version 4) does not give projects a default SDK, despite the above setting.

So, you also (for each project) need to go to File -> Project Structure -> Project Settings -> Project, and select the Project SDK, which is set to [No SDK] by default.

If there's nothing in the drop-down box, then select New, select Android SDK, and navigate to your Android SDK location (normally C:\Users[username]\AppData\Local\Android\Sdk on Windows). You will then be able to select the Android API xx Platform. You now should not get this annoying adb error.

HTH