Programs & Examples On #Persistence ignorance

Get source JARs from Maven repository

Based on watching the Maven console in Eclipse (Kepler), sources will be automatically downloaded for a Maven dependency if you attempt to open a class from said Maven dependency in the editor for which you do not have the sources downloaded already. This is handy when you don't want to grab source for all of your dependencies, but you don't know which ones you want ahead of time (and you're using Eclipse).

I ended up using @GabrielRamierez's approach, but will employ @PascalThivent's approach going forward.

Change the selected value of a drop-down list with jQuery

Just try with

$("._statusDDL").val("2");

and not with

$("._statusDDL").val(2);

Bootstrap 3 collapse accordion: collapse all works but then cannot expand all while maintaining data-parent

To keep the accordion nature intact when wanting to also use 'hide' and 'show' functions like .collapse( 'hide' ), you must initialize the collapsible panels with the parent property set in the object with toggle: false before making any calls to 'hide' or 'show'

// initialize collapsible panels
$('#accordion .collapse').collapse({
  toggle: false,
  parent: '#accordion'
});

// show panel one (will collapse others in accordion)
$( '#collapseOne' ).collapse( 'show' );

// show panel two (will collapse others in accordion)
$( '#collapseTwo' ).collapse( 'show' );

// hide panel two (will not collapse/expand others in accordion)
$( '#collapseTwo' ).collapse( 'hide' );

How can I search sub-folders using glob.glob module?

In Python 3.5 and newer use the new recursive **/ functionality:

configfiles = glob.glob('C:/Users/sam/Desktop/file1/**/*.txt', recursive=True)

When recursive is set, ** followed by a path separator matches 0 or more subdirectories.

In earlier Python versions, glob.glob() cannot list files in subdirectories recursively.

In that case I'd use os.walk() combined with fnmatch.filter() instead:

import os
import fnmatch

path = 'C:/Users/sam/Desktop/file1'

configfiles = [os.path.join(dirpath, f)
    for dirpath, dirnames, files in os.walk(path)
    for f in fnmatch.filter(files, '*.txt')]

This'll walk your directories recursively and return all absolute pathnames to matching .txt files. In this specific case the fnmatch.filter() may be overkill, you could also use a .endswith() test:

import os

path = 'C:/Users/sam/Desktop/file1'

configfiles = [os.path.join(dirpath, f)
    for dirpath, dirnames, files in os.walk(path)
    for f in files if f.endswith('.txt')]

How to force a SQL Server 2008 database to go Offline

Go offline

USE master
GO
ALTER DATABASE YourDatabaseName
SET OFFLINE WITH ROLLBACK IMMEDIATE
GO

Go online

USE master
GO
ALTER DATABASE YourDatabaseName
SET ONLINE
GO

Right way to write JSON deserializer in Spring or extend it

I was trying to @Autowire a Spring-managed service into my Deserializer. Somebody tipped me off to Jackson using the new operator when invoking the serializers/deserializers. This meant no auto-wiring of Jackson's instance of my Deserializer. Here's how I was able to @Autowire my service class into my Deserializer:

context.xml

<mvc:annotation-driven>
  <mvc:message-converters>
    <bean class="org.springframework.http.converter.json.MappingJackson2HttpMessageConverter">
      <property name="objectMapper" ref="objectMapper" />
    </bean>
  </mvc:message-converters>
</mvc>
<bean id="objectMapper" class="org.springframework.http.converter.json.Jackson2ObjectMapperFactoryBean">
    <!-- Add deserializers that require autowiring -->
    <property name="deserializersByType">
        <map key-type="java.lang.Class">
            <entry key="com.acme.Anchor">
                <bean class="com.acme.AnchorDeserializer" />
            </entry>
        </map>
    </property>
</bean>

Now that my Deserializer is a Spring-managed bean, auto-wiring works!

AnchorDeserializer.java

public class AnchorDeserializer extends JsonDeserializer<Anchor> {
    @Autowired
    private AnchorService anchorService;
    public Anchor deserialize(JsonParser parser, DeserializationContext context)
             throws IOException, JsonProcessingException {
        // Do stuff
    }
}

AnchorService.java

@Service
public class AnchorService {}

Update: While my original answer worked for me back when I wrote this, @xi.lin's response is exactly what is needed. Nice find!

Impact of Xcode build options "Enable bitcode" Yes/No

@vj9 thx. I update to xcode 7 . It show me the same error. Build well after set "NO"

enter image description here

set "NO" it works well.

enter image description here

How to generate UML diagrams (especially sequence diagrams) from Java code?

There is a Free tool named binarydoc which can generate UML Sequence Diagram, or Control Flow Graph (CFG) from the bytecode (instead of source code) of a Java method.

Here is an sample diagram binarydoc generated for the java method java.net.AbstractPlainSocketImpl.getInputStream:

  • Control Flow Graph of method java.net.AbstractPlainSocketImpl.getInputStream:

Control Flow Graph

  • UML Sequence Diagram of method java.net.AbstractPlainSocketImpl.getInputStream:

UML Sequence Diagram

When to use "ON UPDATE CASCADE"

I think you've pretty much nailed the points!

If you follow database design best practices and your primary key is never updatable (which I think should always be the case anyway), then you never really need the ON UPDATE CASCADE clause.

Zed made a good point, that if you use a natural key (e.g. a regular field from your database table) as your primary key, then there might be certain situations where you need to update your primary keys. Another recent example would be the ISBN (International Standard Book Numbers) which changed from 10 to 13 digits+characters not too long ago.

This is not the case if you choose to use surrogate (e.g. artifically system-generated) keys as your primary key (which would be my preferred choice in all but the most rare occasions).

So in the end: if your primary key never changes, then you never need the ON UPDATE CASCADE clause.

Marc

The differences between initialize, define, declare a variable

For C, at least, per C11 6.7.5:

A declaration specifies the interpretation and attributes of a set of identifiers. A definition of an identifier is a declaration for that identifier that:

  • for an object, causes storage to be reserved for that object;

  • for a function, includes the function body;

  • for an enumeration constant, is the (only) declaration of the identifier;

  • for a typedef name, is the first (or only) declaration of the identifier.

Per C11 6.7.9.8-10:

An initializer specifies the initial value stored in an object ... if an object that has automatic storage is not initialized explicitly, its value is indeterminate.

So, broadly speaking, a declaration introduces an identifier and provides information about it. For a variable, a definition is a declaration which allocates storage for that variable.

Initialization is the specification of the initial value to be stored in an object, which is not necessarily the same as the first time you explicitly assign a value to it. A variable has a value when you define it, whether or not you explicitly give it a value. If you don't explicitly give it a value, and the variable has automatic storage, it will have an initial value, but that value will be indeterminate. If it has static storage, it will be initialized implicitly depending on the type (e.g. pointer types get initialized to null pointers, arithmetic types get initialized to zero, and so on).

So, if you define an automatic variable without specifying an initial value for it, such as:

int myfunc(void) {
    int myvar;
    ...

You are defining it (and therefore also declaring it, since definitions are declarations), but not initializing it. Therefore, definition does not equal declaration plus initialization.

Recursive file search using PowerShell

Get-ChildItem V:\MyFolder -name -recurse *.CopyForbuild.bat

Will also work

JavaScript string and number conversion

You want to become familiar with parseInt() and toString().

And useful in your toolkit will be to look at a variable to find out what type it is—typeof:

<script type="text/javascript">
    /**
     * print out the value and the type of the variable passed in
     */

    function printWithType(val) {
        document.write('<pre>');
        document.write(val);
        document.write(' ');
        document.writeln(typeof val);
        document.write('</pre>');
    }

    var a = "1", b = "2", c = "3", result;

    // Step (1) Concatenate "1", "2", "3" into "123"
    // - concatenation operator is just "+", as long
    //   as all the items are strings, this works
    result = a + b + c;
    printWithType(result); //123 string

    // - If they were not strings you could do
    result = a.toString() + b.toString() + c.toString();
    printWithType(result); // 123 string

    // Step (2) Convert "123" into 123
    result = parseInt(result,10);
    printWithType(result); // 123 number

    // Step (3) Add 123 + 100 = 223
    result = result + 100;
    printWithType(result); // 223 number

    // Step (4) Convert 223 into "223"
    result = result.toString(); //
    printWithType(result); // 223 string

    // If you concatenate a number with a 
    // blank string, you get a string    
    result = result + "";
    printWithType(result); //223 string
</script>

Group By Multiple Columns

.GroupBy(x => x.Column1 + " " + x.Column2)

Delete all duplicate rows Excel vba

There's a RemoveDuplicates method that you could use:

Sub DeleteRows()

    With ActiveSheet
        Set Rng = Range("A1", Range("B1").End(xlDown))
        Rng.RemoveDuplicates Columns:=Array(1, 2), Header:=xlYes
    End With

End Sub

SQL Server Script to create a new user

You can use:

CREATE LOGIN <login name> WITH PASSWORD = '<password>' ; GO 

To create the login (See here for more details).

Then you may need to use:

CREATE USER user_name 

To create the user associated with the login for the specific database you want to grant them access too.

(See here for details)

You can also use:

GRANT permission  [ ,...n ] ON SCHEMA :: schema_name

To set up the permissions for the schema's that you assigned the users to.

(See here for details)

Two other commands you might find useful are ALTER USER and ALTER LOGIN.

What is the difference between lower bound and tight bound?

Asymptotic upper bound means that a given algorithm executes during the maximum amount of time, depending on the number of inputs.

Let's take a sorting algorithm as an example. If all the elements of an array are in descending order, then to sort them, it will take a running time of O(n), showing upper bound complexity. If the array is already sorted, the value will be O(1).

Generally, O-notation is used for the upper bound complexity.


Asymptotically tight bound (c1g(n) ≤ f(n) ≤ c2g(n)) shows the average bound complexity for a function, having a value between bound limits (upper bound and lower bound), where c1 and c2 are constants.

How to handle ETIMEDOUT error?

We could look at error object for a property code that mentions the possible system error and in cases of ETIMEDOUT where a network call fails, act accordingly.

if (err.code === 'ETIMEDOUT') {
    console.log('My dish error: ', util.inspect(err, { showHidden: true, depth: 2 }));
}

How to align checkboxes and their labels consistently cross-browsers

Maybe some folk are making the same mistake I did? Which was... I had set a width for the input boxes, because they were mostly of type 'text' , but then forgotten to over-ride that width for checkboxes - so my checkbox was trying to occupy a lot of excess width and so it was tough to align a label beside it.

.checkboxlabel {
    width: 100%;
    vertical-align: middle;
}
.checkbox {
    width: 20px !important;
}
<label for='acheckbox' class='checkboxlabel'>
    <input name="acheckbox" id='acheckbox' type="checkbox" class='checkbox'>Contact me</label>

Gives clickable labels and and proper alignment as far back as IE6 (using a class selector) and in late versions of Firefox, Safari and Chrome

node: command not found

The problem is that your PATH does not include the location of the node executable.

You can likely run node as "/usr/local/bin/node".

You can add that location to your path by running the following command to add a single line to your bashrc file:

echo 'export PATH=$PATH:/usr/local/bin' >> $HOME/.bashrc

Bin size in Matplotlib (Histogram)

I use quantiles to do bins uniform and fitted to sample:

bins=df['Generosity'].quantile([0,.05,0.1,0.15,0.20,0.25,0.3,0.35,0.40,0.45,0.5,0.55,0.6,0.65,0.70,0.75,0.80,0.85,0.90,0.95,1]).to_list()

plt.hist(df['Generosity'], bins=bins, normed=True, alpha=0.5, histtype='stepfilled', color='steelblue', edgecolor='none')

enter image description here

How to remove origin from git repository

Fairly straightforward:

git remote rm origin

As for the filter-branch question - just add --prune-empty to your filter branch command and it'll remove any revision that doesn't actually contain any changes in your resulting repo:

git filter-branch --prune-empty --subdirectory-filter path/to/subtree HEAD

What is a "callable"?

A callable is anything that can be called.

The built-in callable (PyCallable_Check in objects.c) checks if the argument is either:

  • an instance of a class with a __call__ method or
  • is of a type that has a non null tp_call (c struct) member which indicates callability otherwise (such as in functions, methods etc.)

The method named __call__ is (according to the documentation)

Called when the instance is ''called'' as a function

Example

class Foo:
  def __call__(self):
    print 'called'

foo_instance = Foo()
foo_instance() #this is calling the __call__ method

Transpose a matrix in Python

You can use zip with * to get transpose of a matrix:

>>> A = [[ 1, 2, 3],[ 4, 5, 6]]
>>> zip(*A)
[(1, 4), (2, 5), (3, 6)]
>>> lis  = [[1,2,3], 
... [4,5,6],
... [7,8,9]]
>>> zip(*lis)
[(1, 4, 7), (2, 5, 8), (3, 6, 9)]

If you want the returned list to be a list of lists:

>>> [list(x) for x in zip(*lis)]
[[1, 4, 7], [2, 5, 8], [3, 6, 9]]
#or
>>> map(list, zip(*lis))
[[1, 4, 7], [2, 5, 8], [3, 6, 9]]

Angular 2 'component' is not a known element

I am beginning Angular and in my case, the issue was that I hadn't saved the file after adding the 'import' statement.

Why is it said that "HTTP is a stateless protocol"?

From Wikipedia:

HTTP is a stateless protocol. A stateless protocol does not require the server to retain information or status about each user for the duration of multiple requests.

But some web applications may have to track the user's progress from page to page, for example when a web server is required to customize the content of a web page for a user. Solutions for these cases include:

  • the use of HTTP cookies.
  • server side sessions,
  • hidden variables (when the current page contains a form), and
  • URL-rewriting using URI-encoded parameters, e.g., /index.php?session_id=some_unique_session_code.

What makes the protocol stateless is that the server is not required to track state over multiple requests, not that it cannot do so if it wants to. This simplifies the contract between client and server, and in many cases (for instance serving up static data over a CDN) minimizes the amount of data that needs to be transferred. If servers were required to maintain the state of clients' visits the structure of issuing and responding to requests would be more complex. As it is, the simplicity of the model is one of its greatest features.

Is there a .NET/C# wrapper for SQLite?

http://www.devart.com/dotconnect/sqlite/

dotConnect for SQLite is an enhanced data provider for SQLite that builds on ADO.NET technology to present a complete solution for developing SQLite-based database applications. As a part of the Devart database application development framework, dotConnect for SQLite offers both high performance native connectivity to the SQLite database and a number of innovative development tools and technologies.

dotConnect for SQLite introduces new approaches for designing application architecture, boosts productivity, and leverages database application implementation.

I use the standard version,it works perfect :)

Check if all values of array are equal

You can get this one-liner to do what you want using Array.prototype.every, Object.is, and ES6 arrow functions:

const all = arr => arr.every(x => Object.is(arr[0], x));

SQL - ORDER BY 'datetime' DESC

Remove the quotes here:

is:

ORDER BY = 'post_datetime DESC' AND LIMIT = '3'

Should be:

ORDER BY post_datetime DESC LIMIT 3

Where is svcutil.exe in Windows 7?

If you are using vs 2010 then you can get it in

C:\Program Files (x86)\Microsoft SDKs\Windows\v7.0A\Bin\NETFX 4.0 Tools

How to install mscomct2.ocx file from .cab file (Excel User Form and VBA)

You're correct that this is really painful to hand out to others, but if you have to, this is how you do it.

  1. Just extract the .ocx file from the .cab file (it is similar to a zip)
  2. Copy to the system folder (c:\windows\sysWOW64 for 64 bit systems and c:\windows\system32 for 32 bit)
  3. Use regsvr32 through the command prompt to register the file (e.g. "regsvr32 c:\windows\sysWOW64\mscomct2.ocx")

References

Can I force a UITableView to hide the separator between empty cells?

Using the link from Daniel, I made an extension to make it more usable:

//UITableViewController+Ext.m
- (void)hideEmptySeparators
{
    UIView *v = [[UIView alloc] initWithFrame:CGRectZero];
    v.backgroundColor = [UIColor clearColor];
    [self.tableView setTableFooterView:v];
    [v release];
}

After some testings, I found out that the size can be 0 and it works as well. So it doesn't add some kind of margin at the end of the table. So thanks wkw for this hack. I decided to post that here since I don't like redirect.

How to include an HTML page into another HTML page without frame/iframe?

If you're just trying to stick in your own HTML from another file, and you consider a Server Side Include to be "pure HTML" (because it kind of looks like an HTML comment and isn't using something "dirty" like PHP):

<!--#include virtual="/footer.html" -->

Global Events in Angular

DO Not Use EventEmitter for your service communication.

You should use one of the Observable types. I personally like BehaviorSubject.

Simple example:

You can pass initial state, here I passing null

let subject = new BehaviorSubject(null);

When you want to update the subject

subject.next(myObject)

Observe from any service or component and act when it gets new updates.

subject.subscribe(this.YOURMETHOD);

Here is more information..

Npm Please try using this command again as root/administrator

If you're in react native project, and Expo is running, then close it.

Re-install the package, and everything should be fine.

Check if starting characters of a string are alphabetical in T-SQL

You don't need to use regex, LIKE is sufficient:

WHERE my_field LIKE '[a-zA-Z][a-zA-Z]%'

Assuming that by "alphabetical" you mean only latin characters, not anything classified as alphabetical in Unicode.

Note - if your collation is case sensitive, it's important to specify the range as [a-zA-Z]. [a-z] may exclude A or Z. [A-Z] may exclude a or z.

Pointer vs. Reference

Pointers

  • A pointer is a variable that holds a memory address.
  • A pointer declaration consists of a base type, an *, and the variable name.
  • A pointer can point to any number of variables in lifetime
  • A pointer that does not currently point to a valid memory location is given the value null (Which is zero)

    BaseType* ptrBaseType;
    BaseType objBaseType;
    ptrBaseType = &objBaseType;
    
  • The & is a unary operator that returns the memory address of its operand.

  • Dereferencing operator (*) is used to access the value stored in the variable which pointer points to.

       int nVar = 7;
       int* ptrVar = &nVar;
       int nVar2 = *ptrVar;
    

Reference

  • A reference (&) is like an alias to an existing variable.

  • A reference (&) is like a constant pointer that is automatically dereferenced.

  • It is usually used for function argument lists and function return values.

  • A reference must be initialized when it is created.

  • Once a reference is initialized to an object, it cannot be changed to refer to another object.

  • You cannot have NULL references.

  • A const reference can refer to a const int. It is done with a temporary variable with value of the const

    int i = 3;    //integer declaration
    int * pi = &i;    //pi points to the integer i
    int& ri = i;    //ri is refers to integer i – creation of reference and initialization
    

enter image description here

enter image description here

how to prevent this error : Warning: mysql_fetch_assoc() expects parameter 1 to be resource, boolean given in ... on line 11

This is how you should be using mysql_fetch_assoc():

$result = mysql_query($query);

while ($row = mysql_fetch_assoc($result)) {
    // Do stuff with $row
}

$result should be a resource. Even if the query returns no rows, $result is still a resource. The only time $result is a boolean value, is if there was an error when querying the database. In which case, you should find out what that error is by using mysql_error() and ensure that it can't happen. Then you don't have to hide from any errors.

You should always cover the base that errors may happen by doing:

if (!$result) {
    die(mysql_error());
}

At least then you'll be more likely to actually fix the error, rather than leave the users with a glaring ugly error in their face.

Javascript wait() function

You shouldn't edit it, you should completely scrap it.

Any attempt to make execution stop for a certain amount of time will lock up the browser and switch it to a Not Responding state. The only thing you can do is use setTimeout correctly.

How to get response from S3 getObject in Node.js?

Alternatively you could use minio-js client library get-object.js

var Minio = require('minio')

var s3Client = new Minio({
  endPoint: 's3.amazonaws.com',
  accessKey: 'YOUR-ACCESSKEYID',
  secretKey: 'YOUR-SECRETACCESSKEY'
})

var size = 0
// Get a full object.
s3Client.getObject('my-bucketname', 'my-objectname', function(e, dataStream) {
  if (e) {
    return console.log(e)
  }
  dataStream.on('data', function(chunk) {
    size += chunk.length
  })
  dataStream.on('end', function() {
    console.log("End. Total size = " + size)
  })
  dataStream.on('error', function(e) {
    console.log(e)
  })
})

Disclaimer: I work for Minio Its open source, S3 compatible object storage written in golang with client libraries available in Java, Python, Js, golang.

Change Name of Import in Java, or import two classes with the same name

It's probably worth noting that Groovy has this feature:

import java.util.Calendar
import com.example.Calendar as MyCalendar

MyCalendar myCalendar = new MyCalendar()

"Mixed content blocked" when running an HTTP AJAX operation in an HTTPS page

If you are just visiting a webpage that you trust and you want to move forward fast, just:

1- Click the shield icon in the far right of the address bar.

Allow mixed content in Google Chrome

2- In the pop-up window, click "Load anyway" or "Load unsafe script" (depending on your Chrome version).


If you want to set your Chrome browser to ALWAYS(in all webpages) allow mixed content:

1- In an open Chrome browser, press Ctrl+Shift+Q on your keyboard to force close Chrome. Chrome must be fully closed before the next steps.

2- Right-click the Google Chrome desktop icon (or Start Menu link). Select Properties.

3- At the end of the existing information in the Target field, add: " --allow-running-insecure-content" (There is a space before the first dash.)

4- Click OK.

5- Open Chrome and try to launch the content that was blocked earlier. It should work now.

How to make a phone call programmatically?

You forgot to call startActivity. It should look like this:

Intent intent = new Intent(Intent.ACTION_CALL);

intent.setData(Uri.parse("tel:" + bundle.getString("mobilePhone")));
context.startActivity(intent);

An intent by itself is simply an object that describes something. It doesn't do anything.

Don't forget to add the relevant permission to your manifest:

<uses-permission android:name="android.permission.CALL_PHONE" />

How to see an HTML page on Github as a normal rendered HTML page to see preview in browser, without downloading?

You can use RawGit:
https://rawgit.com/necolas/css3-social-signin-buttons/master/index.html

It works better (at the time of this writing) than http://htmlpreview.github.com/, serving files with proper Content-Type headers. Additionally, it also provides CDN URL for use in production.

How to display the value of the bar on each bar with pyplot.barh()?

I have noticed api example code contains an example of barchart with the value of the bar displayed on each bar:

"""
========
Barchart
========

A bar plot with errorbars and height labels on individual bars
"""
import numpy as np
import matplotlib.pyplot as plt

N = 5
men_means = (20, 35, 30, 35, 27)
men_std = (2, 3, 4, 1, 2)

ind = np.arange(N)  # the x locations for the groups
width = 0.35       # the width of the bars

fig, ax = plt.subplots()
rects1 = ax.bar(ind, men_means, width, color='r', yerr=men_std)

women_means = (25, 32, 34, 20, 25)
women_std = (3, 5, 2, 3, 3)
rects2 = ax.bar(ind + width, women_means, width, color='y', yerr=women_std)

# add some text for labels, title and axes ticks
ax.set_ylabel('Scores')
ax.set_title('Scores by group and gender')
ax.set_xticks(ind + width / 2)
ax.set_xticklabels(('G1', 'G2', 'G3', 'G4', 'G5'))

ax.legend((rects1[0], rects2[0]), ('Men', 'Women'))


def autolabel(rects):
    """
    Attach a text label above each bar displaying its height
    """
    for rect in rects:
        height = rect.get_height()
        ax.text(rect.get_x() + rect.get_width()/2., 1.05*height,
                '%d' % int(height),
                ha='center', va='bottom')

autolabel(rects1)
autolabel(rects2)

plt.show()

output:

enter image description here

FYI What is the unit of height variable in "barh" of matplotlib? (as of now, there is no easy way to set a fixed height for each bar)

rails 3.1.0 ActionView::Template::Error (application.css isn't precompiled)

I also had this issue, where trying to run in production without precompiling it would still throw not-precompiled errors. I had to change which line was commented application.rb:

  # If you precompile assets before deploying to production, use this line
  # Bundler.require(*Rails.groups(:assets => %w(development test)))
  # If you want your assets lazily compiled in production, use this line
  Bundler.require(:default, :assets, Rails.env)

What is "Linting"?

Interpreted languages like Python and JavaScript benefit greatly from linting, as these languages don’t have a compiling phase to display errors before execution.

Linters are also useful for code formatting and/or adhering to language specific best practices.

Lately I have been using ESLint for JS/React and will occasionally use it with an airbnb-config file.

What is a .pid file and what does it contain?

To understand pid files, refer this DOC

Some times there are certain applications that require additional support of extra plugins and utilities. So it keeps track of these utilities and plugin process running ids using this pid file for reference.

That is why whenever you restart an application all necessary plugins and dependant apps must be restarted since the pid file will become stale.

how to write javascript code inside php

You can put up all your JS like this, so it doesn't execute before your HTML is ready

$(document).ready(function() {
   // some code here
 });

Remember this is jQuery so include it in the head section. Also see Why you should use jQuery and not onload

#ifdef replacement in the Swift language

func inDebugBuilds(_ code: () -> Void) {
    assert({ code(); return true }())
}

Source

Bound method error

I think you meant print test.sorted_word_list instead of print test.sort_word_list.

In addition list.sort() sorts a list in place and returns None, so you probably want to change sort_word_list() to do the following:

self.sorted_word_list = sorted(self.word_list)

You should also consider either renaming your num_words() function, or changing the attribute that the function assigns to, because currently you overwrite the function with an integer on the first call.

Change the row color in DataGridView based on the quantity of a cell value

Using the CellFormating event and the e argument:

If CInt(e.Value) < 5 Then e.CellStyle.ForeColor = Color.Red

Vue.JS: How to call function after page loaded?

You import the function from outside the main instance, and don't add it to the methods block. so the context of this is not the vm.

Either do this:

ready() {
  checkAuth.call(this)
}

or add the method to your methods first (which will make Vue bind this correctly for you) and call this method:

methods: {
  checkAuth: checkAuth
},
ready() {
  this.checkAuth()
}

How do I remove objects from an array in Java?

In an array of Strings like

String name = 'a b c d e a f b d e' // could be like String name = 'aa bb c d e aa f bb d e'

I build the following class

class clearname{
def parts
def tv
public def str = ''
String name
clearname(String name){
    this.name = name
    this.parts = this.name.split(" ")
    this.tv = this.parts.size()
}
public String cleared(){

        int i
        int k
        int j=0        
    for(i=0;i<tv;i++){
        for(k=0;k<tv;k++){
            if(this.parts[k] == this.parts[i] && k!=i){
               this.parts[k] = '';
                j++
            }
        }
    }
    def str = ''
    for(i=0;i<tv;i++){
        if(this.parts[i]!='')

           this.str += this.parts[i].trim()+' '
    } 
    return this.str    
}}



return new clearname(name).cleared()

getting this result

a b c d e f

hope this code help anyone Regards

No resource found that matches the given name: attr 'android:keyboardNavigationCluster'. when updating to Support Library 26.0.0

I had this exact error and I realized the my compileSdkVersion was set at 25 and my buildToolsVersion was set at "26.0.1".

So I just changed the compileSdkVersion to 26 and synced the Gradle. it fixed the problem for me.

EDIT: my targetSDKVersion was also set as 26

The #include<iostream> exists, but I get an error: identifier "cout" is undefined. Why?

cout is in std namespace, you shall use std::cout in your code. And you shall not add using namespace std; in your header file, it's bad to mix your code with std namespace, especially don't add it in header file.

how to open Jupyter notebook in chrome on windows

Take any html file on your computer and set the default browser to open html files to chrome. This will automatically open jupyter notebook with chrome. Worked for me.

How to create a POJO?

import java.io.Serializable;

public class Course implements Serializable {

    protected int courseId;
    protected String courseName;
    protected String courseType;

    public Course() {
        courseName = new String();
        courseType = new String();
    }

    public Course(String courseName, String courseType) {
        this.courseName = courseName;
        this.courseType = courseType;
    }

    public Course(int courseId, String courseName, String courseType) {
        this.courseId = courseId;
        this.courseName = courseName;
        this.courseType = courseType;
    }

    public int getCourseId() {
        return courseId;
    }

    public void setCourseId(int courseId) {
        this.courseId = courseId;
    }

    public String getCourseName() {
        return courseName;
    }

    public void setCourseName(String courseName) {
        this.courseName = courseName;
    }

    public String getCourseType() {
        return courseType;
    }

    public void setCourseType(String courseType) {
        this.courseType = courseType;
    }

    @Override
    public int hashCode() {
        return courseId;
    }

    @Override
    public boolean equals(Object obj) {
        if (obj != null || obj instanceof Course) {
            Course c = (Course) obj;
            if (courseId == c.courseId && courseName.equals(c.courseName)
                    && courseType.equals(c.courseType))
                return true;
        }
        return false;
    }

    @Override
    public String toString() {
        return "Course[" + courseId + "," + courseName + "," + courseType + "]";
    }
}

How to Load RSA Private Key From File

Two things. First, you must base64 decode the mykey.pem file yourself. Second, the openssl private key format is specified in PKCS#1 as the RSAPrivateKey ASN.1 structure. It is not compatible with java's PKCS8EncodedKeySpec, which is based on the SubjectPublicKeyInfo ASN.1 structure. If you are willing to use the bouncycastle library you can use a few classes in the bouncycastle provider and bouncycastle PKIX libraries to make quick work of this.

import java.io.BufferedReader;
import java.io.FileReader;
import java.security.KeyPair;
import java.security.Security;

import org.bouncycastle.jce.provider.BouncyCastleProvider;
import org.bouncycastle.openssl.PEMKeyPair;
import org.bouncycastle.openssl.PEMParser;
import org.bouncycastle.openssl.jcajce.JcaPEMKeyConverter;

// ...   

String keyPath = "mykey.pem";
BufferedReader br = new BufferedReader(new FileReader(keyPath));
Security.addProvider(new BouncyCastleProvider());
PEMParser pp = new PEMParser(br);
PEMKeyPair pemKeyPair = (PEMKeyPair) pp.readObject();
KeyPair kp = new JcaPEMKeyConverter().getKeyPair(pemKeyPair);
pp.close();
samlResponse.sign(Signature.getInstance("SHA1withRSA").toString(), kp.getPrivate(), certs);

Java Compare Two List's object values?

You can subtract one list from the other using CollectionUtils.subtract, if the result is an empty collection, it means both lists are the same. Another approach is using CollectionUtils.isSubCollection or CollectionUtils.isProperSubCollection.

For any case you should implement equals and hashCode methods for your object.

JNZ & CMP Assembly Instructions

JNZ     Jump if Not Zero    ZF=0

Indeed, this is confusing right.

To make it easier to understand, replace Not Zero with Not Set. (Please take note this is for your own understanding)

Hence,

JNZ     Jump if Not Set     ZF=0

Not Set means flag Z = 0. So Jump (Jump if Not Set)

Set means flag Z = 1. So, do NOT Jump

best way to create object

Or you can use a data file to put many person objects in to a list or array. You do need to use the System.IO for this. And you need a data file which contains all the information about the objects.

A method for it would look something like this:

static void ReadFile()
{
    using(StreamWriter writer = new StreamWriter(@"Data.csv"))
    {
        string line = null;
        line = reader.ReadLine();
        while(null!= (line = reader.ReadLine())
                {
                    string[] values = line.Split(',');
                    string name = values[0];
                    int age = int.Parse(values[1]);
                }
        Person person = new Person(name, age);
    }
}

How do I make text bold in HTML?

The HTML element defines bold text, without any extra importance.

<b>This text is bold</b>

The HTML element defines strong text, with added semantic "strong" importance.

<strong>This text is strong</strong>

How to convert a "dd/mm/yyyy" string to datetime in SQL Server?

The last argument of CONVERT seems to determine the format used for parsing. Consult MSDN docs for CONVERT.

111 - the one you are using is Japan yy/mm/dd.

I guess the one you are looking for is 103, that is dd/mm/yyyy.

So you should try:

 SELECT convert(datetime, '23/07/2009', 103)

"Actual or formal argument lists differs in length"

Say you have defined your class like this:

    @Data
    @AllArgsConstructor(staticName = "of")
    private class Pair<P,Q> {

        public P first;
        public Q second;
    }

So when you will need to create a new instance, it will need to take the parameters and you will provide it like this as defined in the annotation.

Pair<Integer, String> pair = Pair.of(menuItemId, category);

If you define it like this, you will get the error asked for.

Pair<Integer, String> pair = new Pair(menuItemId, category);

How to put text over images in html?

You need to use absolutely-positioned CSS over a relatively-positioned img tag. The article Text Blocks Over Image gives a step-by-step example for placing text over an image.

position fixed header in html

Well! As I saw my question now, I realized that I didn't want to mention fixed margin value because of the dynamic height of header.

Here is what I have been using for such scenarios.

Calculate the header height using jQuery and apply that as a top margin value.

var divHeight = $('#header-wrap').height(); 
$('#container').css('margin-top', divHeight+'px');

Demo

Is there Java HashMap equivalent in PHP?

Arrays in PHP can have Key Value structure.

How to encode the plus (+) symbol in a URL

In order to encode + value using JavaScript, you can use encodeURIComponent function.

Example:

_x000D_
_x000D_
var url = "+11";
var encoded_url = encodeURIComponent(url);
console.log(encoded_url)
_x000D_
_x000D_
_x000D_

How to use the start command in a batch file?

An extra pair of rabbits' ears should do the trick.

start "" "C:\Program...

START regards the first quoted parameter as the window-title, unless it's the only parameter - and any switches up until the executable name are regarded as START switches.

R: "Unary operator error" from multiline ggplot2 command

This is a well-known nuisance when posting multiline commands in R. (You can get different behavior when you source() a script to when you copy-and-paste the lines, both with multiline and comments)

Rule: always put the dangling '+' at the end of a line so R knows the command is unfinished:

ggplot(...) + geom_whatever1(...) +
  geom_whatever2(...) +
  stat_whatever3(...) +
  geom_title(...) + scale_y_log10(...)

Don't put the dangling '+' at the start of the line, since that tickles the error:

Error in "+ geom_whatever2(...) invalid argument to unary operator"

And obviously don't put dangling '+' at both end and start since that's a syntax error.

So, learn a habit of being consistent: always put '+' at end-of-line.

cf. answer to "Split code over multiple lines in an R script"

How to edit log message already committed in Subversion?

If you are using an IDE like eclipse, you can use this easy way.

Right click on the project -> Team - Show history

In that right click on the revision id for your commit and select 'Set commit properties'.

You can modify the message as you want from here.

How to show all rows by default in JQuery DataTable

Use:

$('#example').dataTable({
    aLengthMenu: [
        [25, 50, 100, 200, -1],
        [25, 50, 100, 200, "All"]
    ],
    iDisplayLength: -1
});

Or if using 1.10+

$('#example').dataTable({
    paging: false
});

The option you should use is iDisplayLength:

$('#adminProducts').dataTable({
  'iDisplayLength': 100
});

$('#table').DataTable({
   "lengthMenu": [ [5, 10, 25, 50, -1], [5, 10, 25, 50, "All"] ]
});

It will Load by default all entries.

$('#example').dataTable({
    aLengthMenu: [
        [25, 50, 100, 200, -1],
        [25, 50, 100, 200, "All"]
    ],
    iDisplayLength: -1
});

Or if using 1.10+

$('#example').dataTable({
    paging: false
});

If you want to load by default 25 not all do this.

$('#example').dataTable({
    aLengthMenu: [
        [25, 50, 100, 200, -1],
        [25, 50, 100, 200, "All"]
    ],
});

Change URL without refresh the page

Update

Based on Manipulating the browser history, passing the empty string as second parameter of pushState method (aka title) should be safe against future changes to the method, so it's better to use pushState like this:

history.pushState(null, '', '/en/step2');    

You can read more about that in mentioned article

Original Answer

Use history.pushState like this:

history.pushState(null, null, '/en/step2');

Update 2 to answer Idan Dagan's comment:

Why not using history.replaceState()?

From MDN

history.replaceState() operates exactly like history.pushState() except that replaceState() modifies the current history entry instead of creating a new one

That means if you use replaceState, yes the url will be changed but user can not use Browser's Back button to back to prev. state(s) anymore (because replaceState doesn't add new entry to history) and it's not recommended and provide bad UX.

Update 3 to add window.onpopstate

So, as this answer got your attention, here is additional info about manipulating the browser history, after using pushState, you can detect the back/forward button navigation by using window.onpopstate like this:

window.onpopstate = function(e) {
    // ... 
};

As the first argument of pushState is an object, if you passed an object instead of null, you can access that object in onpopstate which is very handy, here is how:

window.onpopstate = function(e) {
    if(e.state) {
        console.log(e.state);
    }
};

Update 4 to add Reading the current state:

When your page loads, it might have a non-null state object, you can read the state of the current history entry without waiting for a popstate event using the history.state property like this:

console.log(history.state);

Bonus: Use following to check history.pushState support:

if (history.pushState) {
  // \o/
}

Convert the first element of an array to a string in PHP

If your goal is output your array to a string for debbuging: you can use the print_r() function, which receives an expression parameter (your array), and an optional boolean return parameter. Normally the function is used to echo the array, but if you set the return parameter as true, it will return the array impression.

Example:

    //We create a 2-dimension Array as an example
    $ProductsArray = array();

    $row_array['Qty'] = 20;
    $row_array['Product'] = "Cars";

    array_push($ProductsArray,$row_array);

    $row_array2['Qty'] = 30;
    $row_array2['Product'] = "Wheels";

    array_push($ProductsArray,$row_array2);

    //We save the Array impression into a variable using the print_r function
    $ArrayString = print_r($ProductsArray, 1);

    //You can echo the string
    echo $ArrayString;

    //or Log the string into a Log file
    $date = date("Y-m-d H:i:s", time());
    $LogFile = "Log.txt";
    $fh = fopen($LogFile, 'a') or die("can't open file");
    $stringData = "--".$date."\n".$ArrayString."\n";
    fwrite($fh, $stringData);
    fclose($fh);

This will be the output:

Array
(
    [0] => Array
        (
            [Qty] => 20
            [Product] => Cars
        )

    [1] => Array
        (
            [Qty] => 30
            [Product] => Wheels
        )

)

How do you iterate through every file/directory recursively in standard C++?

If using the Win32 API you can use the FindFirstFile and FindNextFile functions.

http://msdn.microsoft.com/en-us/library/aa365200(VS.85).aspx

For recursive traversal of directories you must inspect each WIN32_FIND_DATA.dwFileAttributes to check if the FILE_ATTRIBUTE_DIRECTORY bit is set. If the bit is set then you can recursively call the function with that directory. Alternatively you can use a stack for providing the same effect of a recursive call but avoiding stack overflow for very long path trees.

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

using namespace std;

bool ListFiles(wstring path, wstring mask, vector<wstring>& files) {
    HANDLE hFind = INVALID_HANDLE_VALUE;
    WIN32_FIND_DATA ffd;
    wstring spec;
    stack<wstring> directories;

    directories.push(path);
    files.clear();

    while (!directories.empty()) {
        path = directories.top();
        spec = path + L"\\" + mask;
        directories.pop();

        hFind = FindFirstFile(spec.c_str(), &ffd);
        if (hFind == INVALID_HANDLE_VALUE)  {
            return false;
        } 

        do {
            if (wcscmp(ffd.cFileName, L".") != 0 && 
                wcscmp(ffd.cFileName, L"..") != 0) {
                if (ffd.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY) {
                    directories.push(path + L"\\" + ffd.cFileName);
                }
                else {
                    files.push_back(path + L"\\" + ffd.cFileName);
                }
            }
        } while (FindNextFile(hFind, &ffd) != 0);

        if (GetLastError() != ERROR_NO_MORE_FILES) {
            FindClose(hFind);
            return false;
        }

        FindClose(hFind);
        hFind = INVALID_HANDLE_VALUE;
    }

    return true;
}

int main(int argc, char* argv[])
{
    vector<wstring> files;

    if (ListFiles(L"F:\\cvsrepos", L"*", files)) {
        for (vector<wstring>::iterator it = files.begin(); 
             it != files.end(); 
             ++it) {
            wcout << it->c_str() << endl;
        }
    }
    return 0;
}

System.Data.OracleClient requires Oracle client software version 8.1.7

When we first moved over to Vista with Oracle 10g, we experienced this issue when we installed the Oracle client on our Vista boxes, even when we were running with admin privileges during install.

Oracle brought out a new version of the 10g client (10.2.0.3) that was Vista compatible.

I do believe that this was after 11g was released, so it is possible that there is a 'Vista compatible' version for 11g also.

Getting Serial Port Information

I tried so many solutions on here that didn't work for me, only displaying some of the ports. But the following displayed All of them and their information.

        using (var searcher = new ManagementObjectSearcher("SELECT * FROM Win32_PnPEntity WHERE Caption like '%(COM%'"))
        {
            var portnames = SerialPort.GetPortNames();
            var ports = searcher.Get().Cast<ManagementBaseObject>().ToList().Select(p => p["Caption"].ToString());

            var portList = portnames.Select(n => n + " - " + ports.FirstOrDefault(s => s.Contains(n))).ToList();

            foreach(string s in portList)
            {
                Console.WriteLine(s);
            }
        }
    }

Disable ScrollView Programmatically?

Does this help?

((ScrollView)findViewById(R.id.QuranGalleryScrollView)).setOnTouchListener(null);

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>

Adding script tag to React/JSX

I created a React component for this specific case: https://github.com/coreyleelarson/react-typekit

Just need to pass in your Typekit Kit ID as a prop and you're good to go.

import React from 'react';
import Typekit from 'react-typekit';

const HtmlLayout = () => (
  <html>
    <body>
      <h1>My Example React Component</h1>
      <Typekit kitId="abc123" />
    </body>
  </html>
);

export default HtmlLayout;

Can I set the cookies to be used by a WKWebView?

Here is my version of Mattrs solution in Swift for injecting all cookies from HTTPCookieStorage. This was done mainly to inject an authentication cookie to create a user session.

public func setupWebView() {
    let userContentController = WKUserContentController()
    if let cookies = HTTPCookieStorage.shared.cookies {
        let script = getJSCookiesString(for: cookies)
        let cookieScript = WKUserScript(source: script, injectionTime: .atDocumentStart, forMainFrameOnly: false)
        userContentController.addUserScript(cookieScript)
    }
    let webViewConfig = WKWebViewConfiguration()
    webViewConfig.userContentController = userContentController

    self.webView = WKWebView(frame: self.webViewContainer.bounds, configuration: webViewConfig)
}

///Generates script to create given cookies
public func getJSCookiesString(for cookies: [HTTPCookie]) -> String {
    var result = ""
    let dateFormatter = DateFormatter()
    dateFormatter.timeZone = TimeZone(abbreviation: "UTC")
    dateFormatter.dateFormat = "EEE, d MMM yyyy HH:mm:ss zzz"

    for cookie in cookies {
        result += "document.cookie='\(cookie.name)=\(cookie.value); domain=\(cookie.domain); path=\(cookie.path); "
        if let date = cookie.expiresDate {
            result += "expires=\(dateFormatter.stringFromDate(date)); "
        }
        if (cookie.secure) {
            result += "secure; "
        }
        result += "'; "
    }
    return result
}

FormsAuthentication.SignOut() does not log the user out

Are you testing/seeing this behaviour using IE? It's possible that IE is serving up those pages from the cache. It is notoriously hard to get IE to flush it's cache, and so on many occasions, even after you log out, typing the url of one of the "secured" pages would show the cached content from before.

(I've seen this behaviour even when you log as a different user, and IE shows the "Welcome " bar at the top of your page, with the old user's username. Nowadays, usually a reload will update it, but if it's persistant, it could still be a caching issue.)

Completely remove MariaDB or MySQL from CentOS 7 or RHEL 7

These steps are working on CentOS 6.5 so they should work on CentOS 7 too:

(EDIT - exactly the same steps work for MariaDB 10.3 on CentOS 8)

  1. yum remove mariadb mariadb-server
  2. rm -rf /var/lib/mysql If your datadir in /etc/my.cnf points to a different directory, remove that directory instead of /var/lib/mysql
  3. rm /etc/my.cnf the file might have already been deleted at step 1
  4. Optional step: rm ~/.my.cnf
  5. yum install mariadb mariadb-server

[EDIT] - Update for MariaDB 10.1 on CentOS 7

The steps above worked for CentOS 6.5 and MariaDB 10.

I've just installed MariaDB 10.1 on CentOS 7 and some of the steps are slightly different.

Step 1 would become:

yum remove MariaDB-server MariaDB-client

Step 5 would become:

yum install MariaDB-server MariaDB-client

The other steps remain the same.

How to show changed file name only with git log?

This gives almost what you need:

git log --stat --oneline

Commit id + short one line still remains, followed by list of changed files by that commit.

how to call service method from ng-change of select in angularjs?

You have at least two issues in your code:

  • ng-change="getScoreData(Score)

    Angular doesn't see getScoreData method that refers to defined service

  • getScoreData: function (Score, callback)

    We don't need to use callback since GET returns promise. Use then instead.

Here is a working example (I used random address only for simulation):

HTML

<select ng-model="score"
        ng-change="getScoreData(score)" 
        ng-options="score as score.name for score in  scores"></select>
    <pre>{{ScoreData|json}}</pre> 

JS

var fessmodule = angular.module('myModule', ['ngResource']);

fessmodule.controller('fessCntrl', function($scope, ScoreDataService) {

    $scope.scores = [{
        name: 'Bukit Batok Street 1',
        URL: 'http://maps.googleapis.com/maps/api/geocode/json?address=Singapore, SG, Singapore, 153 Bukit Batok Street 1&sensor=true'
    }, {
        name: 'London 8',
        URL: 'http://maps.googleapis.com/maps/api/geocode/json?address=Singapore, SG, Singapore, London 8&sensor=true'
    }];

    $scope.getScoreData = function(score) {
        ScoreDataService.getScoreData(score).then(function(result) {
            $scope.ScoreData = result;
        }, function(result) {
            alert("Error: No data returned");
        });
    };

});

fessmodule.$inject = ['$scope', 'ScoreDataService'];

fessmodule.factory('ScoreDataService', ['$http', '$q', function($http) {

    var factory = {
        getScoreData: function(score) {
            console.log(score);
            var data = $http({
                method: 'GET',
                url: score.URL
            });


            return data;
        }
    }
    return factory;
}]);

Demo Fiddle

Initializing a static std::map<int, int> in C++

You can try:

std::map <int, int> mymap = 
{
        std::pair <int, int> (1, 1),
        std::pair <int, int> (2, 2),
        std::pair <int, int> (2, 2)
};

How can I represent an infinite number in Python?

In Python, you can do:

test = float("inf")

In Python 3.5, you can do:

import math
test = math.inf

And then:

test > 1
test > 10000
test > x

Will always be true. Unless of course, as pointed out, x is also infinity or "nan" ("not a number").

Additionally (Python 2.x ONLY), in a comparison to Ellipsis, float(inf) is lesser, e.g:

float('inf') < Ellipsis

would return true.

How can I create a correlation matrix in R?

Have a look at qtlcharts. It allows you to create interactive correlation matrices:

library(qtlcharts)
data(iris)
iris$Species <- NULL
iplotCorr(iris, reorder=TRUE)

enter image description here

It's more impressive when you correlate more variables, like in the package's vignette: enter image description here

Best way to check if an PowerShell Object exist?

Type-check with the -is operator returns false for any null value. In most cases, if not all, $value -is [System.Object] will be true for any possible non-null value. (In all cases, it will be false for any null-value.)

My value is nothing if not an object.

How can I create an executable JAR with dependencies using Maven?

There are millions of answers already, I wanted to add you don't need <mainClass> if you don't need to add entryPoint to your application. For example APIs may not have necessarily have main method.

maven plugin config

  <build>
    <finalName>log-enrichment</finalName>
    <plugins>
      <plugin>
        <artifactId>maven-assembly-plugin</artifactId>
        <configuration>
          <descriptorRefs>
            <descriptorRef>jar-with-dependencies</descriptorRef>
          </descriptorRefs>
        </configuration>
      </plugin>
    </plugins>
  </build>

build

mvn clean compile assembly:single

verify

ll target/
total 35100
drwxrwx--- 1 root vboxsf     4096 Sep 29 16:25 ./
drwxrwx--- 1 root vboxsf     4096 Sep 29 16:25 ../
drwxrwx--- 1 root vboxsf        0 Sep 29 16:08 archive-tmp/
drwxrwx--- 1 root vboxsf        0 Sep 29 16:25 classes/
drwxrwx--- 1 root vboxsf        0 Sep 29 16:25 generated-sources/
drwxrwx--- 1 root vboxsf        0 Sep 29 16:25 generated-test-sources/
-rwxrwx--- 1 root vboxsf 35929841 Sep 29 16:10 log-enrichment-jar-with-dependencies.jar*
drwxrwx--- 1 root vboxsf        0 Sep 29 16:08 maven-status/

How can I get a character in a string by index?

Do you mean like this

int index = 2;
string s = "hello";
Console.WriteLine(s[index]);

string also implements IEnumberable<char> so you can also enumerate it like this

foreach (char c in s)
    Console.WriteLine(c);

Use CSS to automatically add 'required field' asterisk to form inputs

To put it exactly INTO input as it is shown on the following image:

enter image description here

I found the following approach:

.asterisk_input::after {
content:" *"; 
color: #e32;
position: absolute; 
margin: 0px 0px 0px -20px; 
font-size: xx-large; 
padding: 0 5px 0 0; }
 <form>
    <div>              
        <input type="text" size="15" />                                 
        <span class="asterisk_input">  </span>            
    </div>            
</form> 

Site on which I work is coded using fixed layout so it was ok for me.

I'm not sure that that it's good for liquid design.

jquery $(this).id return Undefined

use this actiion

$(document).ready(function () {
var a = this.id;

alert (a);
});

How to use http.client in Node.js if there is basic authorization

var username = "Ali";
var password = "123";
var auth = "Basic " + new Buffer(username + ":" + password).toString("base64");
var request = require('request');
var url = "http://localhost:5647/contact/session/";

request.get( {
    url : url,
    headers : {
        "Authorization" : auth
    }
  }, function(error, response, body) {
      console.log('body : ', body);
  } );

SQL Server: IF EXISTS ; ELSE

EDIT

I want to add the reason that your IF statement seems to not work. When you do an EXISTS on an aggregate, it's always going to be true. It returns a value even if the ID doesn't exist. Sure, it's NULL, but its returning it. Instead, do this:

if exists(select 1 from table where id = 4)

and you'll get to the ELSE portion of your IF statement.


Now, here's a better, set-based solution:

update b
  set code = isnull(a.value, 123)
from #b b
left join (select id, max(value) from #a group by id) a
  on b.id = a.id
where
  b.id = yourid

This has the benefit of being able to run on the entire table rather than individual ids.

Find most frequent value in SQL column

Below query seems to work good for me in SQL Server database:

select column, COUNT(column) AS MOST_FREQUENT
from TABLE_NAME
GROUP BY column
ORDER BY COUNT(column) DESC

Result:

column          MOST_FREQUENT
item1           highest count
item2           second highest 
item3           third higest
..
..

Eclipse - Failed to create the java virtual machine

it works for me after changing MaxPermSize=512M to MaxPermSize=256M

Display List in a View MVC

You are passing wrong mode to you view. Your view is looking for @model IEnumerable<Standings.Models.Teams> and you are passing var model = tm.Name.ToList(); name list. You have to pass list of Teams.

You have to pass following model

var model = new List<Teams>();

model.Add(new Teams { Name =  new List<string>(){"Sky","ABC"}});
model.Add(new Teams { Name =  new List<string>(){"John","XYZ"} });
return View(model);

Converting Decimal to Binary Java

    int n = 13;
    String binary = "";

    //decimal to binary
    while (n > 0) {
        int d = n & 1;
        binary = d + binary;
        n = n >> 1;
    }
    System.out.println(binary);

    //binary to decimal
    int power = 1;
    n = 0;
    for (int i = binary.length() - 1; i >= 0; i--) {
        n = n + Character.getNumericValue(binary.charAt(i)) * power;
        power = power * 2;
    }

    System.out.println(n);

How can I analyze a heap dump in IntelliJ? (memory leak)

I would like to update the answers above to 2018 and say to use both VisualVM and Eclipse MAT.

How to use:

VisualVM is used for live monitoring and dump heap. You can also analyze the heap dumps there with great power, however MAT have more capabilities (such as automatic analysis to find leaks) and therefore, I read the VisualVM dump output (.hprof file) into MAT.



Get VisualVM:

Download VisualVM here: https://visualvm.github.io/

You also need to download the plugin for Intellij: enter image description here

Then you'll see in intellij another 2 new orange icons: enter image description here

Once you run your app with an orange one, in VisualVM you'll see your process on the left, and data on the right. Sit some time and learn this tool, it is very powerful: enter image description here



Get Eclipse's Memory Analysis Tool (MAT) as a standalone:

Download here: https://www.eclipse.org/mat/downloads.php

And this is how it looks: enter image description here enter image description here

Hope it helps!

How to check Oracle patches are installed?

Here is an article on how to check and or install new patches :


To find the OPatch tool setup your database enviroment variables and then issue this comand:

cd $ORACLE_HOME/OPatch 
> pwd
/oracle/app/product/10.2.0/db_1/OPatch

To list all the patches applies to your database use the lsinventory option:

[oracle@DCG023 8828328]$ opatch lsinventory
Oracle Interim Patch Installer version 11.2.0.3.4
Copyright (c) 2012, Oracle Corporation. All rights reserved.

Oracle Home : /u00/product/11.2.0/dbhome_1
Central Inventory : /u00/oraInventory
from : /u00/product/11.2.0/dbhome_1/oraInst.loc
OPatch version : 11.2.0.3.4
OUI version : 11.2.0.1.0
Log file location : /u00/product/11.2.0/dbhome_1/cfgtoollogs/opatch/opatch2013-11-13_13-55-22PM_1.log
Lsinventory Output file location : /u00/product/11.2.0/dbhome_1/cfgtoollogs/opatch/lsinv/lsinventory2013-11-13_13-55-22PM.txt


Installed Top-level Products (1):
Oracle Database 11g 11.2.0.1.0
There are 1 products installed in this Oracle Home.

Interim patches (1) :
Patch 8405205 : applied on Mon Aug 19 15:18:04 BRT 2013
Unique Patch ID: 11805160
Created on 23 Sep 2009, 02:41:32 hrs PST8PDT
Bugs fixed:
8405205

OPatch succeeded.

To list the patches using sql :

select * from registry$history;

How to combine multiple conditions to subset a data-frame using "OR"?

my.data.frame <- subset(data , V1 > 2 | V2 < 4)

An alternative solution that mimics the behavior of this function and would be more appropriate for inclusion within a function body:

new.data <- data[ which( data$V1 > 2 | data$V2 < 4) , ]

Some people criticize the use of which as not needed, but it does prevent the NA values from throwing back unwanted results. The equivalent (.i.e not returning NA-rows for any NA's in V1 or V2) to the two options demonstrated above without the which would be:

 new.data <- data[ !is.na(data$V1 | data$V2) & ( data$V1 > 2 | data$V2 < 4)  , ]

Note: I want to thank the anonymous contributor that attempted to fix the error in the code immediately above, a fix that got rejected by the moderators. There was actually an additional error that I noticed when I was correcting the first one. The conditional clause that checks for NA values needs to be first if it is to be handled as I intended, since ...

> NA & 1
[1] NA
> 0 & NA
[1] FALSE

Order of arguments may matter when using '&".

Checking if any elements in one list are in another

You could solve this many ways. One that is pretty simple to understand is to just use a loop.

def comp(list1, list2):
    for val in list1:
        if val in list2:
            return True
    return False

A more compact way you can do it is to use map and reduce:

reduce(lambda v1,v2: v1 or v2, map(lambda v: v in list2, list1))

Even better, the reduce can be replaced with any:

any(map(lambda v: v in list2, list1))

You could also use sets:

len(set(list1).intersection(list2)) > 0

Why can't Python find shared objects that are in directories in sys.path?

sys.path is only searched for Python modules. For dynamic linked libraries, the paths searched must be in LD_LIBRARY_PATH. Check if your LD_LIBRARY_PATH includes /usr/local/lib, and if it doesn't, add it and try again.

Some more information (source):

In Linux, the environment variable LD_LIBRARY_PATH is a colon-separated set of directories where libraries should be searched for first, before the standard set of directories; this is useful when debugging a new library or using a nonstandard library for special purposes. The environment variable LD_PRELOAD lists shared libraries with functions that override the standard set, just as /etc/ld.so.preload does. These are implemented by the loader /lib/ld-linux.so. I should note that, while LD_LIBRARY_PATH works on many Unix-like systems, it doesn't work on all; for example, this functionality is available on HP-UX but as the environment variable SHLIB_PATH, and on AIX this functionality is through the variable LIBPATH (with the same syntax, a colon-separated list).

Update: to set LD_LIBRARY_PATH, use one of the following, ideally in your ~/.bashrc or equivalent file:

export LD_LIBRARY_PATH=/usr/local/lib

or

export LD_LIBRARY_PATH=/usr/local/lib:$LD_LIBRARY_PATH

Use the first form if it's empty (equivalent to the empty string, or not present at all), and the second form if it isn't. Note the use of export.

How to create a new object instance from a Type

If you want to use the default constructor then the solution using System.Activator presented earlier is probably the most convenient. However, if the type lacks a default constructor or you have to use a non-default one, then an option is to use reflection or System.ComponentModel.TypeDescriptor. In case of reflection, it is enough to know just the type name (with its namespace).

Example using reflection:

ObjectType instance = 
    (ObjectType)System.Reflection.Assembly.GetExecutingAssembly().CreateInstance(
        typeName: objectType.FulName, // string including namespace of the type
        ignoreCase: false,
        bindingAttr: BindingFlags.Default,
        binder: null,  // use default binder
        args: new object[] { args, to, constructor },
        culture: null, // use CultureInfo from current thread
        activationAttributes: null
    );

Example using TypeDescriptor:

ObjectType instance = 
    (ObjectType)System.ComponentModel.TypeDescriptor.CreateInstance(
        provider: null, // use standard type description provider, which uses reflection
        objectType: objectType,
        argTypes: new Type[] { types, of, args },
        args: new object[] { args, to, constructor }
    );

Variables declared outside function

When Python parses a function, it notes when a variable assignment is made. When there is an assignment, it assumes by default that that variable is a local variable. To declare that the assignment refers to a global variable, you must use the global declaration.

When you access a variable in a function, its value is looked up using the LEGB scoping rules.


So, the first example

  x = 1
  def inc():
      x += 5
  inc()

produces an UnboundLocalError because Python determined x inside inc to be a local variable,

while accessing x works in your second example

 def inc():
    print x

because here, in accordance with the LEGB rule, Python looks for x in the local scope, does not find it, then looks for it in the extended scope, still does not find it, and finally looks for it in the global scope successfully.

Creating a "Hello World" WebSocket example

I couldnt find a simple working example anywhere (as of Jan 19), so here is an updated version. I have chrome version 71.0.3578.98.

C# Websocket server :

using System;
using System.Text;
using System.Net;
using System.Net.Sockets;
using System.Security.Cryptography;

namespace WebSocketServer
{
    class Program
    {
    static Socket serverSocket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.IP);
    static private string guid = "258EAFA5-E914-47DA-95CA-C5AB0DC85B11";

    static void Main(string[] args)
    {
        serverSocket.Bind(new IPEndPoint(IPAddress.Any, 8080));
        serverSocket.Listen(1); //just one socket
        serverSocket.BeginAccept(null, 0, OnAccept, null);
        Console.Read();
    }

    private static void OnAccept(IAsyncResult result)
    {
        byte[] buffer = new byte[1024];
        try
        {
            Socket client = null;
            string headerResponse = "";
            if (serverSocket != null && serverSocket.IsBound)
            {
                client = serverSocket.EndAccept(result);
                var i = client.Receive(buffer);
                headerResponse = (System.Text.Encoding.UTF8.GetString(buffer)).Substring(0, i);
                // write received data to the console
                Console.WriteLine(headerResponse);
                Console.WriteLine("=====================");
            }
            if (client != null)
            {
                /* Handshaking and managing ClientSocket */
                var key = headerResponse.Replace("ey:", "`")
                          .Split('`')[1]                     // dGhlIHNhbXBsZSBub25jZQ== \r\n .......
                          .Replace("\r", "").Split('\n')[0]  // dGhlIHNhbXBsZSBub25jZQ==
                          .Trim();

                // key should now equal dGhlIHNhbXBsZSBub25jZQ==
                var test1 = AcceptKey(ref key);

                var newLine = "\r\n";

                var response = "HTTP/1.1 101 Switching Protocols" + newLine
                     + "Upgrade: websocket" + newLine
                     + "Connection: Upgrade" + newLine
                     + "Sec-WebSocket-Accept: " + test1 + newLine + newLine
                     //+ "Sec-WebSocket-Protocol: chat, superchat" + newLine
                     //+ "Sec-WebSocket-Version: 13" + newLine
                     ;

                client.Send(System.Text.Encoding.UTF8.GetBytes(response));
                var i = client.Receive(buffer); // wait for client to send a message
                string browserSent = GetDecodedData(buffer, i);
                Console.WriteLine("BrowserSent: " + browserSent);

                Console.WriteLine("=====================");
                //now send message to client
                client.Send(GetFrameFromString("This is message from server to client."));
                System.Threading.Thread.Sleep(10000);//wait for message to be sent
            }
        }
        catch (SocketException exception)
        {
            throw exception;
        }
        finally
        {
            if (serverSocket != null && serverSocket.IsBound)
            {
                serverSocket.BeginAccept(null, 0, OnAccept, null);
            }
        }
    }

    public static T[] SubArray<T>(T[] data, int index, int length)
    {
        T[] result = new T[length];
        Array.Copy(data, index, result, 0, length);
        return result;
    }

    private static string AcceptKey(ref string key)
    {
        string longKey = key + guid;
        byte[] hashBytes = ComputeHash(longKey);
        return Convert.ToBase64String(hashBytes);
    }

    static SHA1 sha1 = SHA1CryptoServiceProvider.Create();
    private static byte[] ComputeHash(string str)
    {
        return sha1.ComputeHash(System.Text.Encoding.ASCII.GetBytes(str));
    }

    //Needed to decode frame
    public static string GetDecodedData(byte[] buffer, int length)
    {
        byte b = buffer[1];
        int dataLength = 0;
        int totalLength = 0;
        int keyIndex = 0;

        if (b - 128 <= 125)
        {
            dataLength = b - 128;
            keyIndex = 2;
            totalLength = dataLength + 6;
        }

        if (b - 128 == 126)
        {
            dataLength = BitConverter.ToInt16(new byte[] { buffer[3], buffer[2] }, 0);
            keyIndex = 4;
            totalLength = dataLength + 8;
        }

        if (b - 128 == 127)
        {
            dataLength = (int)BitConverter.ToInt64(new byte[] { buffer[9], buffer[8], buffer[7], buffer[6], buffer[5], buffer[4], buffer[3], buffer[2] }, 0);
            keyIndex = 10;
            totalLength = dataLength + 14;
        }

        if (totalLength > length)
            throw new Exception("The buffer length is small than the data length");

        byte[] key = new byte[] { buffer[keyIndex], buffer[keyIndex + 1], buffer[keyIndex + 2], buffer[keyIndex + 3] };

        int dataIndex = keyIndex + 4;
        int count = 0;
        for (int i = dataIndex; i < totalLength; i++)
        {
            buffer[i] = (byte)(buffer[i] ^ key[count % 4]);
            count++;
        }

        return Encoding.ASCII.GetString(buffer, dataIndex, dataLength);
    }

    //function to create  frames to send to client 
    /// <summary>
    /// Enum for opcode types
    /// </summary>
    public enum EOpcodeType
    {
        /* Denotes a continuation code */
        Fragment = 0,

        /* Denotes a text code */
        Text = 1,

        /* Denotes a binary code */
        Binary = 2,

        /* Denotes a closed connection */
        ClosedConnection = 8,

        /* Denotes a ping*/
        Ping = 9,

        /* Denotes a pong */
        Pong = 10
    }

    /// <summary>Gets an encoded websocket frame to send to a client from a string</summary>
    /// <param name="Message">The message to encode into the frame</param>
    /// <param name="Opcode">The opcode of the frame</param>
    /// <returns>Byte array in form of a websocket frame</returns>
    public static byte[] GetFrameFromString(string Message, EOpcodeType Opcode = EOpcodeType.Text)
    {
        byte[] response;
        byte[] bytesRaw = Encoding.Default.GetBytes(Message);
        byte[] frame = new byte[10];

        int indexStartRawData = -1;
        int length = bytesRaw.Length;

        frame[0] = (byte)(128 + (int)Opcode);
        if (length <= 125)
        {
            frame[1] = (byte)length;
            indexStartRawData = 2;
        }
        else if (length >= 126 && length <= 65535)
        {
            frame[1] = (byte)126;
            frame[2] = (byte)((length >> 8) & 255);
            frame[3] = (byte)(length & 255);
            indexStartRawData = 4;
        }
        else
        {
            frame[1] = (byte)127;
            frame[2] = (byte)((length >> 56) & 255);
            frame[3] = (byte)((length >> 48) & 255);
            frame[4] = (byte)((length >> 40) & 255);
            frame[5] = (byte)((length >> 32) & 255);
            frame[6] = (byte)((length >> 24) & 255);
            frame[7] = (byte)((length >> 16) & 255);
            frame[8] = (byte)((length >> 8) & 255);
            frame[9] = (byte)(length & 255);

            indexStartRawData = 10;
        }

        response = new byte[indexStartRawData + length];

        int i, reponseIdx = 0;

        //Add the frame bytes to the reponse
        for (i = 0; i < indexStartRawData; i++)
        {
            response[reponseIdx] = frame[i];
            reponseIdx++;
        }

        //Add the data bytes to the response
        for (i = 0; i < length; i++)
        {
            response[reponseIdx] = bytesRaw[i];
            reponseIdx++;
        }

        return response;
    }
}
}

Client html and javascript:

_x000D_
_x000D_
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"_x000D_
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">_x000D_
<html xmlns="http://www.w3.org/1999/xhtml">_x000D_
<head>_x000D_
    <script type="text/javascript">_x000D_
        var socket = new WebSocket('ws://localhost:8080/websession');_x000D_
        socket.onopen = function() {_x000D_
           // alert('handshake successfully established. May send data now...');_x000D_
     socket.send("Hi there from browser.");_x000D_
        };_x000D_
  socket.onmessage = function (evt) {_x000D_
                //alert("About to receive data");_x000D_
                var received_msg = evt.data;_x000D_
                alert("Message received = "+received_msg);_x000D_
            };_x000D_
        socket.onclose = function() {_x000D_
            alert('connection closed');_x000D_
        };_x000D_
    </script>_x000D_
</head>_x000D_
<body>_x000D_
</body>_x000D_
</html>
_x000D_
_x000D_
_x000D_

How to extract the file name from URI returned from Intent.ACTION_GET_CONTENT?

If you want it short this should work.

Uri uri= data.getData();
File file= new File(uri.getPath());
file.getName();

Listing all extras of an Intent

Bundle extras = getIntent().getExtras();
Set<String> ks = extras.keySet();
Iterator<String> iterator = ks.iterator();
while (iterator.hasNext()) {
    Log.d("KEY", iterator.next());
}

mongodb how to get max value from collections

You can also achieve this through aggregate pipeline.

db.collection.aggregate([{$sort:{age:-1}}, {$limit:1}])

Python-equivalent of short-form "if" in C++

While a = 'foo' if True else 'bar' is the more modern way of doing the ternary if statement (python 2.5+), a 1-to-1 equivalent of your version might be:

a = (b == True and "123" or "456" )

... which in python should be shortened to:

a = b is True and "123" or "456"

... or if you simply want to test the truthfulness of b's value in general...

a = b and "123" or "456"

? : can literally be swapped out for and or

Set content of iframe

I needed to reuse the same iframe and replace the content each time. I've tried a few ways and this worked for me:

// Set the iframe's src to about:blank so that it conforms to the same-origin policy 
iframeElement.src = "about:blank";

// Set the iframe's new HTML
iframeElement.contentWindow.document.open();
iframeElement.contentWindow.document.write(newHTML);
iframeElementcontentWindow.document.close();

Here it is as a function:

function replaceIframeContent(iframeElement, newHTML)
{
    iframeElement.src = "about:blank";
    iframeElement.contentWindow.document.open();
    iframeElement.contentWindow.document.write(newHTML);
    iframeElement.contentWindow.document.close();
}

How do I pull from a Git repository through an HTTP proxy?

The above answers worked for me when my proxy doesn't need authentication. If you are using proxy which requires you to authenticate then you may try CCProxy. I have small tutorial on how to set it up here,

http://blog.praveenkumar.co.in/2012/09/proxy-free-windows-xp78-and-mobiles.html

I was able to push, pull, create new repos. Everything worked just fine. Make sure you do a clean uninstall and reinstall of new version if you are facing issues with Git like I did.

Java null check why use == instead of .equals()

I have encountered this case last night.
I determine that simply that:

Don't exist equals() method for null
So, you can not invoke an inexistent method if you don't have
-->>> That is reason for why we use == to check null

CS1617: Invalid option ‘6’ for /langversion; must be ISO-1, ISO-2, 3, 4, 5 or Default

The easiest solution for me was upgrading the .Net Compilers via Package Manager

Install-Package Microsoft.Net.Compilers

and then changing the Web.Config lines to this

<system.codedom>
 <compilers>
  <compiler language="c#;cs;csharp" extension=".cs" type="Microsoft.CodeDom.Providers.DotNetCompilerPlatform.CSharpCodeProvider, Microsoft.CodeDom.Providers.DotNetCompilerPlatform, Version=1.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" warningLevel="4" compilerOptions="/langversion:6 /nowarn:1659;1699;1701" />
  <compiler language="vb;vbs;visualbasic;vbscript" extension=".vb" type="Microsoft.CodeDom.Providers.DotNetCompilerPlatform.VBCodeProvider, Microsoft.CodeDom.Providers.DotNetCompilerPlatform, Version=1.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" warningLevel="4" compilerOptions="/langversion:14 /nowarn:41008 /define:_MYTYPE=\&quot;Web\&quot; /optionInfer+" />
 </compilers>
</system.codedom>

Change key pair for ec2 instance

This answer is useful in the case you no longer have SSH access to the existing server (i.e. you lost your private key).

If you still have SSH access, please use one of the answers below.

https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/ec2-key-pairs.html#replacing-lost-key-pair

Here is what I did, thanks to Eric Hammond's blog post:

  1. Stop the running EC2 instance
  2. Detach its /dev/xvda1 volume (let's call it volume A) - see here
  3. Start new t1.micro EC2 instance, using my new key pair. Make sure you create it in the same subnet, otherwise you will have to terminate the instance and create it again. - see here
  4. Attach volume A to the new micro instance, as /dev/xvdf (or /dev/sdf)
  5. SSH to the new micro instance and mount volume A to /mnt/tmp
$ sudo mkdir /mnt/tmp; sudo mount /dev/xvdf1 /mnt/tmp
  1. Copy ~/.ssh/authorized_keys to /mnt/tmp/home/ubuntu/.ssh/authorized_keys
  2. Logout
  3. Terminate micro instance
  4. Detach volume A from it
  5. Attach volume A back to the main instance as /dev/xvda
  6. Start the main instance
  7. Login as before, using your new .pem file

That's it.

How to get all elements inside "div" that starts with a known text

Presuming every new branch in your tree is a div, I have implemented this solution with 2 functions:

function fillArray(vector1,vector2){
    for (var i = 0; i < vector1.length; i++){
        if (vector1[i].id.indexOf('q17_') == 0)
            vector2.push(vector1[i]);
        if(vector1[i].tagName == 'DIV')
            fillArray (document.getElementById(vector1[i].id).children,vector2);
    }
}

function selectAllElementsInsideDiv(divId){ 
    var matches = new Array();
    var searchEles = document.getElementById(divId).children;
    fillArray(searchEles,matches);
    return matches;
}

Now presuming your div's id is 'myDiv', all you have to do is create an array element and set its value to the function's return:

var ElementsInsideMyDiv = new Array();
ElementsInsideMyDiv =  selectAllElementsInsideDiv('myDiv')

I have tested it and it worked for me. I hope it helps you.

How to pass 2D array (matrix) in a function in C?

I don't know what you mean by "data dont get lost". Here's how you pass a normal 2D array to a function:

void myfunc(int arr[M][N]) { // M is optional, but N is required
  ..
}

int main() {
  int somearr[M][N];
  ...
  myfunc(somearr);
  ...
}

Solve error javax.mail.AuthenticationFailedException

Just in case anyone comes looking a solution for this problem.

The Authentication problems can be alleviated by activating the google 2-step verification for the account in use and creating an app specific password. I had the same problem as the OP. Enabling 2-step worked.

PHP header redirect 301 - what are the implications?

Search engines like 301 redirects better than a 404 or some other type of client side redirect, no worries there.

CPU usage will be minimal, if you want to save even more cycles you could try and handle the redirect in apache using htaccess, then php won't even have to get involved. If you want to load test a server, you can use ab which comes with apache, or httperf if you are looking for a more robust testing tool.

How to get elements with multiple classes

As @filoxo said, you can use document.querySelectorAll.

If you know that there is only one element with the class you are looking for, or you are interested only in the first one, you can use:

document.querySelector('.class1.class2');

BTW, while .class1.class2 indicates an element with both classes, .class1 .class2 (notice the whitespace) indicates an hierarchy - and element with class class2 which is inside en element with class class1:

<div class='class1'>
  <div>
    <div class='class2'>
      :
      :

And if you want to force retrieving a direct child, use > sign (.class1 > .class2):

<div class='class1'>
  <div class='class2'>
    :
    :

For entire information about selectors:
https://www.w3schools.com/jquery/jquery_ref_selectors.asp

How to put img inline with text

This should display the image inline:

.content-dir-item img.mail {
    display: inline-block;
    *display: inline; /* for older IE */
    *zoom: 1; /* for older IE */
}

Deleting all files in a directory with Python

In Python 3.5, os.scandir is better if you need to check for file attributes or type - see os.DirEntry for properties of the object that's returned by the function.

import os 

for file in os.scandir(path):
    if file.name.endswith(".bak"):
        os.unlink(file.path)

This also doesn't require changing directories since each DirEntry already includes the full path to the file.

Error pushing to GitHub - insufficient permission for adding an object to repository database

Oddly enough, I had this issue on one clone of the repo I had, but not another I had. Aside from re-cloning the repo (which a coworker did to successfully get around this issue), I managed to do a "git reset" to the commit I had before the failures started. Then I re-committed the changes, and I was able to push successfully after that. So despite all the indications there was a problem on the server, in this case it apparently was indicative of some oddity in the local repo.

How to align td elements in center

The best way to center content in a table (for example <video> or <img>) is to do the following:

_x000D_
_x000D_
<table width="100%" border="0" cellspacing="0" cellpadding="100%">
<tr>
<td>Video Tag 1 Here</td>
<td>Video Tag 2 Here</td>
</tr>
</table>
_x000D_
_x000D_
_x000D_

Environment variables in Mac OS X

For 2020 Mac OS X Catalina users:

Forget about other useless answers, here only two steps needed:

  1. Create a file with the naming convention: priority-appname. Then copy-paste the path you want to add to PATH.

    E.g. 80-vscode with content /Applications/Visual Studio Code.app/Contents/Resources/app/bin/ in my case.

  2. Move that file to /etc/paths.d/. Don't forget to open a new tab(new session) in the Terminal and type echo $PATH to check that your path is added!

Notice: this method only appends your path to PATH.

Synchronously waiting for an async operation, and why does Wait() freeze the program here

Calling async code from synchronous code can be quite tricky.

I explain the full reasons for this deadlock on my blog. In short, there's a "context" that is saved by default at the beginning of each await and used to resume the method.

So if this is called in an UI context, when the await completes, the async method tries to re-enter that context to continue executing. Unfortunately, code using Wait (or Result) will block a thread in that context, so the async method cannot complete.

The guidelines to avoid this are:

  1. Use ConfigureAwait(continueOnCapturedContext: false) as much as possible. This enables your async methods to continue executing without having to re-enter the context.
  2. Use async all the way. Use await instead of Result or Wait.

If your method is naturally asynchronous, then you (probably) shouldn't expose a synchronous wrapper.

C# listView, how do I add items to columns 2, 3 and 4 etc?

One line that i've made and it works:

listView1.Items.Add(new ListViewItem { ImageIndex = 0, Text = randomArray["maintext"], SubItems = { randomArray["columntext2"], randomArray["columntext3"] } });

Read file-contents into a string in C++

Here's an iterator-based method.

ifstream file("file", ios::binary);
string fileStr;

istreambuf_iterator<char> inputIt(file), emptyInputIt
back_insert_iterator<string> stringInsert(fileStr);

copy(inputIt, emptyInputIt, stringInsert);

Cleanest way to toggle a boolean variable in Java?

Unfortunately, there is no short form like numbers have increment/decrement:

i++;

I would like to have similar short expression to invert a boolean, dmth like:

isEmpty!;

In Flask, What is request.args and how is it used?

request.args is a MultiDict with the parsed contents of the query string. From the documentation of get method:

get(key, default=None, type=None)

Return the default value if the requested data doesn’t exist. If type is provided and is a callable it should convert the value, return it or raise a ValueError if that is not possible.

char initial value in Java

you can initialize it to ' ' instead. Also, the reason that you received an error -1 being too many characters is because it is treating '-' and 1 as separate.

set div height using jquery (stretch div height)

The correct way to do this is with good-old CSS:

#content{
    width:100%;
    position:absolute;
    top:35px;
    bottom:35px;
}

And the bonus is that you don't need to attach to the window.onresize event! Everything will adjust as the document reflows. All for the low-low price of four lines of CSS!

C++ convert string to hexadecimal and vice versa

This will convert Hello World to 48656c6c6f20576f726c64 and print it.

#include <iostream>
#include <cstring>

using namespace std;

int main()
{
    char hello[20]="Hello World";

    for(unsigned int i=0; i<strlen(hello); i++)
        cout << hex << (int) hello[i];
    return 0;
}

validate natural input number with ngpattern

The problem is that your REGX pattern will only match the input "0-9".

To meet your requirement (0-9999999), you should rewrite your regx pattern:

ng-pattern="/^[0-9]{1,7}$/"

My example:

HTML:

<div ng-app ng-controller="formCtrl">
  <form name="myForm" ng-submit="onSubmit()">
    <input type="number" ng-model="price" name="price_field" 
           ng-pattern="/^[0-9]{1,7}$/" required>
    <span ng-show="myForm.price_field.$error.pattern">Not a valid number!</span>
    <span ng-show="myForm.price_field.$error.required">This field is required!</span>
    <input type="submit" value="submit"/>
  </form>
</div>

JS:

function formCtrl($scope){
  $scope.onSubmit = function(){
    alert("form submitted");
  }
}

Here is a jsFiddle demo.

Reverse / invert a dictionary mapping

To do this while preserving the type of your mapping (assuming that it is a dict or a dict subclass):

def inverse_mapping(f):
    return f.__class__(map(reversed, f.items()))

configure: error: C compiler cannot create executables

First get the gcc path using

Command: which gcc

Output: /usr/bin/gcc

I had the same issue, Please set the gcc path in below command and install

CC=/usr/bin/gcc rvm install 1.9.3

Later if you get "Ruby was built without documentation" run below command

rvm docs generate-ri

How to send PUT, DELETE HTTP request in HttpURLConnection?

For doing a PUT in HTML correctly, you will have to surround it with try/catch:

try {
    url = new URL("http://www.example.com/resource");
    HttpURLConnection httpCon = (HttpURLConnection) url.openConnection();
    httpCon.setDoOutput(true);
    httpCon.setRequestMethod("PUT");
    OutputStreamWriter out = new OutputStreamWriter(
        httpCon.getOutputStream());
    out.write("Resource content");
    out.close();
    httpCon.getInputStream();
} catch (MalformedURLException e) {
    e.printStackTrace();
} catch (ProtocolException e) {
    e.printStackTrace();
} catch (IOException e) {
    e.printStackTrace();
}

Start new Activity and finish current one in Android?

You can use finish() method or you can use:

android:noHistory="true"

And then there is no need to call finish() anymore.

<activity android:name=".ClassName" android:noHistory="true" ... />

After installing SQL Server 2014 Express can't find local db

Also, if you just installed localDB, you won't see the instance in the configuration manager. You would need to initiate it first, and then connect to it using server name (localdb)\mssqllocaldb. Source

Binding List<T> to DataGridView in WinForm

After adding new item to persons add:

myGrid.DataSource = null;
myGrid.DataSource = persons;

How to create a self-signed certificate for a domain name for development?

Using PowerShell

From Windows 8.1 and Windows Server 2012 R2 (Windows PowerShell 4.0) and upwards, you can create a self-signed certificate using the new New-SelfSignedCertificate cmdlet:

Examples:

New-SelfSignedCertificate -DnsName www.mydomain.com -CertStoreLocation cert:\LocalMachine\My

New-SelfSignedCertificate -DnsName subdomain.mydomain.com -CertStoreLocation cert:\LocalMachine\My

New-SelfSignedCertificate -DnsName *.mydomain.com -CertStoreLocation cert:\LocalMachine\My

Using the IIS Manager

  1. Launch the IIS Manager
  2. At the server level, under IIS, select Server Certificates
  3. On the right hand side under Actions select Create Self-Signed Certificate
  4. Where it says "Specify a friendly name for the certificate" type in an appropriate name for reference.
    1. Examples: www.domain.com or subdomain.domain.com
  5. Then, select your website from the list on the left hand side
  6. On the right hand side under Actions select Bindings
  7. Add a new HTTPS binding and select the certificate you just created (if your certificate is a wildcard certificate you'll need to specify a hostname)
  8. Click OK and test it out.

Get all table names of a particular database by SQL query?

Just put the DATABASE NAME in front of INFORMATION_SCHEMA.TABLES:

select table_name from YOUR_DATABASE.INFORMATION_SCHEMA.TABLES where TABLE_TYPE = 'BASE TABLE'

jQuery - Follow the cursor with a DIV

This works for me. Has a nice delayed action going on.

var $mouseX = 0, $mouseY = 0;
var $xp = 0, $yp =0;

$(document).mousemove(function(e){
    $mouseX = e.pageX;
    $mouseY = e.pageY;    
});

var $loop = setInterval(function(){
// change 12 to alter damping higher is slower
$xp += (($mouseX - $xp)/12);
$yp += (($mouseY - $yp)/12);
$("#moving_div").css({left:$xp +'px', top:$yp +'px'});  
}, 30);

Nice and simples

MongoDB via Mongoose JS - What is findByID?

findById is a convenience method on the model that's provided by Mongoose to find a document by its _id. The documentation for it can be found here.

Example:

// Search by ObjectId
var id = "56e6dd2eb4494ed008d595bd";
UserModel.findById(id, function (err, user) { ... } );

Functionally, it's the same as calling:

UserModel.findOne({_id: id}, function (err, user) { ... });

Note that Mongoose will cast the provided id value to the type of _id as defined in the schema (defaulting to ObjectId).

Getting Excel to refresh data on sheet from within VBA

Sometimes Excel will hiccup and needs a kick-start to reapply an equation. This happens in some cases when you are using custom formulas.

Make sure that you have the following script

ActiveSheet.EnableCalculation = True

Reapply the equation of choice.

Cells(RowA,ColB).Formula = Cells(RowA,ColB).Formula

This can then be looped as needed.

Remove element by id

You could make a remove function so that you wouldn't have to think about it every time:

function removeElement(id) {
    var elem = document.getElementById(id);
    return elem.parentNode.removeChild(elem);
}

How to get data out of a Node.js http get request

Simple Working Example of Http request using node.

const http = require('https')

httprequest().then((data) => {
        const response = {
            statusCode: 200,
            body: JSON.stringify(data),
        };
    return response;
});
function httprequest() {
     return new Promise((resolve, reject) => {
        const options = {
            host: 'jsonplaceholder.typicode.com',
            path: '/todos',
            port: 443,
            method: 'GET'
        };
        const req = http.request(options, (res) => {
          if (res.statusCode < 200 || res.statusCode >= 300) {
                return reject(new Error('statusCode=' + res.statusCode));
            }
            var body = [];
            res.on('data', function(chunk) {
                body.push(chunk);
            });
            res.on('end', function() {
                try {
                    body = JSON.parse(Buffer.concat(body).toString());
                } catch(e) {
                    reject(e);
                }
                resolve(body);
            });
        });
        req.on('error', (e) => {
          reject(e.message);
        });
        // send the request
       req.end();
    });
}

How to read from a text file using VBScript?

Dim obj : Set obj = CreateObject("Scripting.FileSystemObject")
Dim outFile : Set outFile = obj.CreateTextFile("in.txt")
Dim inFile: Set inFile = obj.OpenTextFile("out.txt")

' Read file
Dim strRetVal : strRetVal = inFile.ReadAll
inFile.Close

' Write file
outFile.write (strRetVal)
outFile.Close

Label word wrapping

Refer to Automatically Wrap Text in Label. It describes how to create your own growing label.

Here is the full source taken from the above reference:

using System;
using System.Text;
using System.Drawing;
using System.Windows.Forms;

public class GrowLabel : Label {
  private bool mGrowing;
  public GrowLabel() {
    this.AutoSize = false;
  }
  private void resizeLabel() {
    if (mGrowing) return;
    try {
      mGrowing = true;
      Size sz = new Size(this.Width, Int32.MaxValue);
      sz = TextRenderer.MeasureText(this.Text, this.Font, sz, TextFormatFlags.WordBreak);
      this.Height = sz.Height;
    }
    finally {
      mGrowing = false;
    }
  }
  protected override void OnTextChanged(EventArgs e) {
    base.OnTextChanged(e);
    resizeLabel();
  }
  protected override void OnFontChanged(EventArgs e) {
    base.OnFontChanged(e);
    resizeLabel();
  }
  protected override void OnSizeChanged(EventArgs e) {
    base.OnSizeChanged(e);
    resizeLabel();
  }
}

How do I get the directory of the PowerShell script I execute?

PowerShell 3 has the $PSScriptRoot automatic variable:

Contains the directory from which a script is being run.

In Windows PowerShell 2.0, this variable is valid only in script modules (.psm1). Beginning in Windows PowerShell 3.0, it is valid in all scripts.

Don't be fooled by the poor wording. PSScriptRoot is the directory of the current file.

In PowerShell 2, you can calculate the value of $PSScriptRoot yourself:

# PowerShell v2
$PSScriptRoot = Split-Path -Parent -Path $MyInvocation.MyCommand.Definition

Python Infinity - Any caveats?

I found a caveat that no one so far has mentioned. I don't know if it will come up often in practical situations, but here it is for the sake of completeness.

Usually, calculating a number modulo infinity returns itself as a float, but a fraction modulo infinity returns nan (not a number). Here is an example:

>>> from fractions import Fraction
>>> from math import inf
>>> 3 % inf
3.0
>>> 3.5 % inf
3.5
>>> Fraction('1/3') % inf
nan

I filed an issue on the Python bug tracker. It can be seen at https://bugs.python.org/issue32968.

Update: this will be fixed in Python 3.8.

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

There is often the tip to use 'echo.'

But that is slow, and it could fail with an error message, as cmd.exe will search first for a file named 'echo' (without extension) and only when the file doesn't exists it outputs an empty line.

You could use echo(. This is approximately 20 times faster, and it works always. The only drawback could be that it looks odd.

More about the different ECHO:/\ variants is at DOS tips: ECHO. FAILS to give text or blank line.

Create WordPress Page that redirects to another URL

There is a much simpler way in wordpress to create a redirection by using wordpress plugins. So here i found a better way through the plugin Redirection and also you can find other as well on this site Create Url redirect in wordpress through Plugin

Error in setting JAVA_HOME

Do not include bin in your JAVA_HOME env variable

what is an illegal reflective access

Apart from an understanding of the accesses amongst modules and their respective packages. I believe the crux of it lies in the Module System#Relaxed-strong-encapsulation and I would just cherry-pick the relevant parts of it to try and answer the question.

What defines an illegal reflective access and what circumstances trigger the warning?

To aid in the migration to Java-9, the strong encapsulation of the modules could be relaxed.

  • An implementation may provide static access, i.e. by compiled bytecode.

  • May provide a means to invoke its run-time system with one or more packages of one or more of its modules open to code in all unnamed modules, i.e. to code on the classpath. If the run-time system is invoked in this way, and if by doing so some invocations of the reflection APIs succeed where otherwise they would have failed.

In such cases, you've actually ended up making a reflective access which is "illegal" since in a pure modular world you were not meant to do such accesses.

How it all hangs together and what triggers the warning in what scenario?

This relaxation of the encapsulation is controlled at runtime by a new launcher option --illegal-access which by default in Java9 equals permit. The permit mode ensures

The first reflective-access operation to any such package causes a warning to be issued, but no warnings are issued after that point. This single warning describes how to enable further warnings. This warning cannot be suppressed.

The modes are configurable with values debug(message as well as stacktrace for every such access), warn(message for each such access), and deny(disables such operations).


Few things to debug and fix on applications would be:-

  • Run it with --illegal-access=deny to get to know about and avoid opening packages from one module to another without a module declaration including such a directive(opens) or explicit use of --add-opens VM arg.
  • Static references from compiled code to JDK-internal APIs could be identified using the jdeps tool with the --jdk-internals option

The warning message issued when an illegal reflective-access operation is detected has the following form:

WARNING: Illegal reflective access by $PERPETRATOR to $VICTIM

where:

$PERPETRATOR is the fully-qualified name of the type containing the code that invoked the reflective operation in question plus the code source (i.e., JAR-file path), if available, and

$VICTIM is a string that describes the member being accessed, including the fully-qualified name of the enclosing type

Questions for such a sample warning: = JDK9: An illegal reflective access operation has occurred. org.python.core.PySystemState

Last and an important note, while trying to ensure that you do not face such warnings and are future safe, all you need to do is ensure your modules are not making those illegal reflective accesses. :)

Get Excel sheet name and use as variable in macro

in a Visual Basic Macro you would use

pName = ActiveWorkbook.Path      ' the path of the currently active file
wbName = ActiveWorkbook.Name     ' the file name of the currently active file
shtName = ActiveSheet.Name       ' the name of the currently selected worksheet

The first sheet in a workbook can be referenced by

ActiveWorkbook.Worksheets(1)

so after deleting the [Report] tab you would use

ActiveWorkbook.Worksheets("Report").Delete
shtName = ActiveWorkbook.Worksheets(1).Name

to "work on that sheet later on" you can create a range object like

Dim MySheet as Range
MySheet = ActiveWorkbook.Worksheets(shtName).[A1]

and continue working on MySheet(rowNum, colNum) etc. ...

shortcut creation of a range object without defining shtName:

Dim MySheet as Range
MySheet = ActiveWorkbook.Worksheets(1).[A1]

PDF to byte array and vice versa

To convert pdf to byteArray :

public byte[] pdfToByte(String filePath)throws JRException {

         File file = new File(<filePath>);
         FileInputStream fileInputStream;
         byte[] data = null;
         byte[] finalData = null;
         ByteArrayOutputStream byteArrayOutputStream = null;

         try {
            fileInputStream = new FileInputStream(file);
            data = new byte[(int)file.length()];
            finalData = new byte[(int)file.length()];
            byteArrayOutputStream = new ByteArrayOutputStream();

            fileInputStream.read(data);
            byteArrayOutputStream.write(data);
            finalData = byteArrayOutputStream.toByteArray();

            fileInputStream.close(); 

        } catch (FileNotFoundException e) {
            LOGGER.info("File not found" + e);
        } catch (IOException e) {
            LOGGER.info("IO exception" + e);
        }

        return finalData;

    }

Unable to connect to SQL Server instance remotely

I know this is almost 1.5 years old, but I hope I can help someone with what I found.

I had built both a console app and a UWP app and my console connnected fine, but not my UWP. After hours of banging my head against the desk - if it's a intranet server hosting the SQL database you must enable "Private Networks (Client & Server)". It's under Package.appxmanifest and the Capabilities tab.Screenshot

Finding moving average from data points in Python

As numpy.convolve is pretty slow, those who need a fast performing solution might prefer an easier to understand cumsum approach. Here is the code:

cumsum_vec = numpy.cumsum(numpy.insert(data, 0, 0)) 
ma_vec = (cumsum_vec[window_width:] - cumsum_vec[:-window_width]) / window_width

where data contains your data, and ma_vec will contain moving averages of window_width length.

On average, cumsum is about 30-40 times faster than convolve.

Format decimal for percentage values?

Use the P format string. This will vary by culture:

String.Format("Value: {0:P2}.", 0.8526) // formats as 85.26 % (varies by culture)

How do I get the file name from a String containing the Absolute file path?

The other answers didn't quite work for my specific scenario, where I am reading paths that have originated from an OS different to my current one. To elaborate I am saving email attachments saved from a Windows platform on a Linux server. The filename returned from the JavaMail API is something like 'C:\temp\hello.xls'

The solution I ended up with:

String filenameWithPath = "C:\\temp\\hello.xls";
String[] tokens = filenameWithPath.split("[\\\\|/]");
String filename = tokens[tokens.length - 1];

create multiple tag docker image

docker build  -t name1:tag1 -t name2:tag2 -f Dockerfile.ui .

Expected initializer before function name

Try adding a semi colon to the end of your structure:

 struct sotrudnik {
    string name;
    string speciality;
    string razread;
    int zarplata;
} //Semi colon here

How to list the size of each file and directory and sort by descending size in Bash?

I tend to use du in a simple way.

du -sh */ | sort -n

This provides me with an idea of what directories are consuming the most space. I can then run more precise searches later.

is the + operator less performant than StringBuffer.append()

Yes, according to the usual benchmarks. E.G : http://mckoss.com/jscript/SpeedTrial.htm.

But for the small strings, this is irrelevant. You will only care about performances on very large strings. What's more, in most JS script, the bottle neck is rarely on the string manipulations since there is not enough of it.

You'd better watch the DOM manipulation.

How to loop over files in directory and change path and add suffix to filename

A couple of notes first: when you use Data/data1.txt as an argument, should it really be /Data/data1.txt (with a leading slash)? Also, should the outer loop scan only for .txt files, or all files in /Data? Here's an answer, assuming /Data/data1.txt and .txt files only:

#!/bin/bash
for filename in /Data/*.txt; do
    for ((i=0; i<=3; i++)); do
        ./MyProgram.exe "$filename" "Logs/$(basename "$filename" .txt)_Log$i.txt"
    done
done

Notes:

  • /Data/*.txt expands to the paths of the text files in /Data (including the /Data/ part)
  • $( ... ) runs a shell command and inserts its output at that point in the command line
  • basename somepath .txt outputs the base part of somepath, with .txt removed from the end (e.g. /Data/file.txt -> file)

If you needed to run MyProgram with Data/file.txt instead of /Data/file.txt, use "${filename#/}" to remove the leading slash. On the other hand, if it's really Data not /Data you want to scan, just use for filename in Data/*.txt.

Are "while(true)" loops so bad?

I would say that generally the reason it's not considered a good idea is that you are not using the construct to it's full potential. Also, I tend to think that a lot of programming instructors don't like it when their students come in with "baggage". By that I mean I think they like to be the primary influence on their students programming style. So perhaps that's just a pet peeve of the instructor's.

support FragmentPagerAdapter holds reference to old fragments

I faced the same issue but my ViewPager was inside a TopFragment which created and set an adapter using setAdapter(new FragmentPagerAdapter(getChildFragmentManager())).

I fixed this issue by overriding onAttachFragment(Fragment childFragment) in the TopFragment like this:

@Override
public void onAttachFragment(Fragment childFragment) {
    if (childFragment instanceof OnboardingDiamondsFragment) {
        mChildFragment = (ChildFragment) childFragment;
    }

    super.onAttachFragment(childFragment);
}

As known already (see answers above), when the childFragmentManager recreate itself, it also create the fragments which were inside the viewPager.
The important part is that after that, he calls onAttachFragment and now we have a reference to the new recreated fragment!

Hope this will help anyone getting this old Q like me :)

Return list using select new in LINQ

public List<Object> GetProjectForCombo()
{
    using (MyDataContext db = new MyDataContext (DBHelper.GetConnectionString()))
     {
         var query = from pro in db.Projects
                     select new {pro.ProjectName,pro.ProjectId};

         return query.ToList<Object>();
    }
}

how to dynamically add options to an existing select in vanilla javascript

The simplest way is:

selectElement.add(new Option('Text', 'value'));

Yes, that simple. And it works even in IE8. And has other optional parameters.

See docs:

Change the Textbox height?

Just found a great little trick to setting a custom height to a textbox.

In the designer view, set the minimumSize to whatever you desire, and then completely remove the size setting. This will cause the designer to update with the new minimum settings!

Use of "this" keyword in C++

Either way works, but many places have coding standards in place that will guide the developer one way or the other. If such a policy is not in place, just follow your heart. One thing, though, it REALLY helps the readability of the code if you do use it. especially if you are not following a naming convention on class-level variable names.

How can I list all collections in the MongoDB shell?

> show tables

It gives the same result as Cameron's answer.

How to import NumPy in the Python shell

The message is fairly self-explanatory; your working directory should not be the NumPy source directory when you invoke Python; NumPy should be installed and your working directory should be anything but the directory where it lives.

View a specific Git commit

git show <revhash>

Documentation here. Or if that doesn't work, try Google Code's GIT Documentation

How do I change Bootstrap 3 column order on mobile layout?

Updated 2018

For the original question based on Bootstrap 3, the solution was to use push-pull.

In Bootstrap 4 it's now possible to change the order, even when the columns are full-width stacked vertically, thanks to Bootstrap 4 flexbox. OFC, the push pull method will still work, but now there are other ways to change column order in Bootstrap 4, making it possible to re-order full-width columns.

Method 1 - Use flex-column-reverse for xs screens:

<div class="row flex-column-reverse flex-md-row">
    <div class="col-md-3">
        sidebar
    </div>
    <div class="col-md-9">
        main
    </div>
</div>

Method 2 - Use order-first for xs screens:

<div class="row">
    <div class="col-md-3">
        sidebar
    </div>
    <div class="col-md-9 order-first order-md-last">
        main
    </div>
</div>

Bootstrap 4(alpha 6): http://www.codeply.com/go/bBMOsvtJhD
Bootstrap 4.1: https://www.codeply.com/go/e0v77yGtcr


Original 3.x Answer

For the original question based on Bootstrap 3, the solution was to use push-pull for the larger widths, and then the columns will show is their natural order on smaller (xs) widths. (A-B reverse to B-A).

<div class="container">
    <div class="row">
        <div class="col-md-9 col-md-push-3">
            main
        </div>
        <div class="col-md-3 col-md-pull-9">
            sidebar
        </div>
    </div>
</div>

Bootstrap 3: http://www.codeply.com/go/wgzJXs3gel

@emre stated, "You cannot change the order of columns in smaller screens but you can do that in large screens". However, this should be clarified to state: "You cannot change the order of full-width "stacked" columns.." in Bootstrap 3.

Error while inserting date - Incorrect date value:

I had a different cause for this error. I tried to insert a date without using quotes and received a strange error telling me I had tried to insert a date from 2003.

My error message:

Although I was already using the YYYY-MM-DD format, I forgot to add quotes around the date. Even though it is a date and not a string, quotes are still required.

Regular expression to validate US phone numbers?

The easiest way to match both

^\([0-9]{3}\)[0-9]{3}-[0-9]{4}$

and

^[0-9]{3}-[0-9]{3}-[0-9]{4}$

is to use alternation ((...|...)): specify them as two mostly-separate options:

^(\([0-9]{3}\)|[0-9]{3}-)[0-9]{3}-[0-9]{4}$

By the way, when Americans put the area code in parentheses, we actually put a space after that; for example, I'd write (123) 123-1234, not (123)123-1234. So you might want to write:

^(\([0-9]{3}\) |[0-9]{3}-)[0-9]{3}-[0-9]{4}$

(Though it's probably best to explicitly demonstrate the format that you expect phone numbers to be in.)

Plot yerr/xerr as shaded region rather than error bars

This is basically the same answer provided by Evert, but extended to show-off some cool options of fill_between

enter image description here

from matplotlib import pyplot as pl
import numpy as np

pl.clf()
pl.hold(1)

x = np.linspace(0, 30, 100)
y = np.sin(x) * 0.5
pl.plot(x, y, '-k')


x = np.linspace(0, 30, 30)
y = np.sin(x/6*np.pi)
error = np.random.normal(0.1, 0.02, size=y.shape) +.1
y += np.random.normal(0, 0.1, size=y.shape)

pl.plot(x, y, 'k', color='#CC4F1B')
pl.fill_between(x, y-error, y+error,
    alpha=0.5, edgecolor='#CC4F1B', facecolor='#FF9848')

y = np.cos(x/6*np.pi)    
error = np.random.rand(len(y)) * 0.5
y += np.random.normal(0, 0.1, size=y.shape)
pl.plot(x, y, 'k', color='#1B2ACC')
pl.fill_between(x, y-error, y+error,
    alpha=0.2, edgecolor='#1B2ACC', facecolor='#089FFF',
    linewidth=4, linestyle='dashdot', antialiased=True)



y = np.cos(x/6*np.pi)  + np.sin(x/3*np.pi)  
error = np.random.rand(len(y)) * 0.5
y += np.random.normal(0, 0.1, size=y.shape)
pl.plot(x, y, 'k', color='#3F7F4C')
pl.fill_between(x, y-error, y+error,
    alpha=1, edgecolor='#3F7F4C', facecolor='#7EFF99',
    linewidth=0)



pl.show()

In .NET, which loop runs faster, 'for' or 'foreach'?

My guess is that it will probably not be significant in 99% of the cases, so why would you choose the faster instead of the most appropriate (as in easiest to understand/maintain)?

How to use java.Set

Since it is a HashSet you will need to override hashCode and equals methods. http://preciselyconcise.com/java/collections/d_set.php has an example explaining how to implement hashCode and equals methods

Httpd returning 503 Service Unavailable with mod_proxy for Tomcat 8

Resolve issue Immediate, It's related to internal security

We, SnippetBucket.com working for enterprise linux RedHat, found httpd server don't allow proxy to run, neither localhost or 127.0.0.1, nor any other external domain.

As investigate in server log found

[error] (13)Permission denied: proxy: AJP: attempt to connect to
   10.x.x.x:8069 (virtualhost.virtualdomain.com) failed

Audit log found similar port issue

type=AVC msg=audit(1265039669.305:14): avc:  denied  { name_connect } for  pid=4343 comm="httpd" dest=8069 
scontext=system_u:system_r:httpd_t:s0 tcontext=system_u:object_r:port_t:s0 tclass=tcp_socket

Due to internal default security of linux, this cause, now to fix (temporary)

 /usr/sbin/setsebool httpd_can_network_connect 1

Resolve Permanent Issue

/usr/sbin/setsebool -P httpd_can_network_connect 1

How do you specify table padding in CSS? ( table, not cell padding )

You can try the border-spacing property. That should do what you want. But you may want to see this answer.

Python Selenium accessing HTML source

By using the page source you will get the whole HTML code.
So first decide the block of code or tag in which you require to retrieve the data or to click the element..

options = driver.find_elements_by_name_("XXX")
for option in options:
    if option.text == "XXXXXX":
        print(option.text)
        option.click()

You can find the elements by name, XPath, id, link and CSS path.

How to add element into ArrayList in HashMap

First you have to add an ArrayList to the Map

ArrayList<Item> al = new ArrayList<Item>();

Items.add("theKey", al); 

then you can add an item to the ArrayLIst that is inside the Map like this:

Items.get("theKey").add(item);  // item is an object of type Item

What is the correct way to start a mongod service on linux / OS X?

I did a bit of looking around on the Mac side. You may want to use the installer here as it looks like it does all the setup for you to automatically launch on Mac OS. The only downside is it looks like it's using a pretty old mongo version.

This link here also explains the setup to get mongo automatically launching as a background service on the Mac.

Zero-pad digits in string

First of all, your description is misleading. Double is a floating point data type. You presumably want to pad your digits with leading zeros in a string. The following code does that:

$s = sprintf('%02d', $digit);

For more information, refer to the documentation of sprintf.

How to make PyCharm always show line numbers

Version 2.6 and above:
PyCharm (far left menu) -> Preferences... -> Editor (bottom left section) -> General -> Appearance -> Show line numbers checkbox

enter image description here

Version 2.5 and below:
Settings -> Editor -> General -> Appearance -> Show line numbers checkbox

Showing/Hiding Table Rows with Javascript - can do with ID - how to do with Class?

You can change the class of the entire table and use the cascade in the CSS: http://jsbin.com/oyunuy/1/

Google Chrome default opening position and size

Maybe a little late, but I found an easier way to set the defaults! You have to right-click on the right of your tab and choose "size", then click on your window, and it should keep it as the default size.

How can I disable a button in a jQuery dialog from a function?

In the jQuery world, if you want to select an object from a set of DOM elements, you should use eq().

Examples:

var button = $('button').eq(1);

or

var button = $('button:eq(1)');

Oracle query to fetch column names

On Several occasions, we would need comma separated list of all the columns from a table in a schema. In such cases we can use this generic function which fetches the comma separated list as a string.

CREATE OR REPLACE FUNCTION cols(
    p_schema_name IN VARCHAR2,
    p_table_name  IN VARCHAR2)
  RETURN VARCHAR2
IS
  v_string VARCHAR2(4000);
BEGIN
  SELECT LISTAGG(COLUMN_NAME , ',' ) WITHIN GROUP (
  ORDER BY ROWNUM )
  INTO v_string
  FROM ALL_TAB_COLUMNS
  WHERE OWNER    = p_schema_name
  AND table_name = p_table_name;
  RETURN v_string;
END;
/

So, simply calling the function from the query yields a row with all the columns.

select cols('HR','EMPLOYEES') FROM DUAL;

EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE_NUMBER,HIRE_DATE,JOB_ID,SALARY,COMMISSION_PCT,MANAGER_ID,DEPARTMENT_ID

Note: LISTAGG will fail if the combined length of all columns exceed 4000 characters which is rare. For most cases , this will work.

How do I calculate someone's age based on a DateTime type birthday?

To calculate how many years old a person is,

DateTime dateOfBirth;

int ageInYears = DateTime.Now.Year - dateOfBirth.Year;

if (dateOfBirth > today.AddYears(-ageInYears )) ageInYears --;

nodeJs callbacks simple example

A callback function is simply a function you pass into another function so that function can call it at a later time. This is commonly seen in asynchronous APIs; the API call returns immediately because it is asynchronous, so you pass a function into it that the API can call when it's done performing its asynchronous task.

The simplest example I can think of in JavaScript is the setTimeout() function. It's a global function that accepts two arguments. The first argument is the callback function and the second argument is a delay in milliseconds. The function is designed to wait the appropriate amount of time, then invoke your callback function.

setTimeout(function () {
  console.log("10 seconds later...");
}, 10000);

You may have seen the above code before but just didn't realize the function you were passing in was called a callback function. We could rewrite the code above to make it more obvious.

var callback = function () {
  console.log("10 seconds later...");
};
setTimeout(callback, 10000);

Callbacks are used all over the place in Node because Node is built from the ground up to be asynchronous in everything that it does. Even when talking to the file system. That's why a ton of the internal Node APIs accept callback functions as arguments rather than returning data you can assign to a variable. Instead it will invoke your callback function, passing the data you wanted as an argument. For example, you could use Node's fs library to read a file. The fs module exposes two unique API functions: readFile and readFileSync.

The readFile function is asynchronous while readFileSync is obviously not. You can see that they intend you to use the async calls whenever possible since they called them readFile and readFileSync instead of readFile and readFileAsync. Here is an example of using both functions.

Synchronous:

var data = fs.readFileSync('test.txt');
console.log(data);

The code above blocks thread execution until all the contents of test.txt are read into memory and stored in the variable data. In node this is typically considered bad practice. There are times though when it's useful, such as when writing a quick little script to do something simple but tedious and you don't care much about saving every nanosecond of time that you can.

Asynchronous (with callback):

var callback = function (err, data) {
  if (err) return console.error(err);
  console.log(data);
};
fs.readFile('test.txt', callback);

First we create a callback function that accepts two arguments err and data. One problem with asynchronous functions is that it becomes more difficult to trap errors so a lot of callback-style APIs pass errors as the first argument to the callback function. It is best practice to check if err has a value before you do anything else. If so, stop execution of the callback and log the error.

Synchronous calls have an advantage when there are thrown exceptions because you can simply catch them with a try/catch block.

try {
  var data = fs.readFileSync('test.txt');
  console.log(data);
} catch (err) {
  console.error(err);
}

In asynchronous functions it doesn't work that way. The API call returns immediately so there is nothing to catch with the try/catch. Proper asynchronous APIs that use callbacks will always catch their own errors and then pass those errors into the callback where you can handle it as you see fit.

In addition to callbacks though, there is another popular style of API that is commonly used called the promise. If you'd like to read about them then you can read the entire blog post I wrote based on this answer here.

How do you add an ActionListener onto a JButton in Java

I don't know if this works but I made the variable names

public abstract class beep implements ActionListener {
    public static void main(String[] args) {
        JFrame f = new JFrame("beeper");
        JButton button = new JButton("Beep me");
        f.setVisible(true);
        f.setSize(300, 200);
        f.add(button);
        button.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                // Insert code here
            }
        });
    }
}