Programs & Examples On #Symbols

can refer to a letter or special character; a primitive data type in many programming languages; an item of the alphabet of a formal language.

Reference — What does this symbol mean in PHP?

PHP Strings: PHP Strings can be specified in four ways not just two ways:

1) Single Quote Strings:

$string = 'This is my string'; // print This is my string

2) Double Quote Strings:

$str = 'string';

$string = "This is my $str"; // print This is my string

3) Heredoc:

$string = <<<EOD
This is my string
EOD; // print This is my string

4) Nowdoc (since PHP 5.3.0):

$string = <<<'END_OF_STRING'
    This is my string 
END_OF_STRING; // print This is my string

Placing Unicode character in CSS content value

Why don't you just save/serve the CSS file as UTF-8?

nav a:hover:after {
    content: "?";
}

If that's not good enough, and you want to keep it all-ASCII:

nav a:hover:after {
    content: "\2193";
}

The general format for a Unicode character inside a string is \000000 to \FFFFFF – a backslash followed by six hexadecimal digits. You can leave out leading 0 digits when the Unicode character is the last character in the string or when you add a space after the Unicode character. See the spec below for full details.


Relevant part of the CSS2 spec:

Third, backslash escapes allow authors to refer to characters they cannot easily put in a document. In this case, the backslash is followed by at most six hexadecimal digits (0..9A..F), which stand for the ISO 10646 ([ISO10646]) character with that number, which must not be zero. (It is undefined in CSS 2.1 what happens if a style sheet does contain a character with Unicode codepoint zero.) If a character in the range [0-9a-fA-F] follows the hexadecimal number, the end of the number needs to be made clear. There are two ways to do that:

  1. with a space (or other white space character): "\26 B" ("&B"). In this case, user agents should treat a "CR/LF" pair (U+000D/U+000A) as a single white space character.
  2. by providing exactly 6 hexadecimal digits: "\000026B" ("&B")

In fact, these two methods may be combined. Only one white space character is ignored after a hexadecimal escape. Note that this means that a "real" space after the escape sequence must be doubled.

If the number is outside the range allowed by Unicode (e.g., "\110000" is above the maximum 10FFFF allowed in current Unicode), the UA may replace the escape with the "replacement character" (U+FFFD). If the character is to be displayed, the UA should show a visible symbol, such as a "missing character" glyph (cf. 15.2, point 5).

  • Note: Backslash escapes are always considered to be part of an identifier or a string (i.e., "\7B" is not punctuation, even though "{" is, and "\32" is allowed at the start of a class name, even though "2" is not).
    The identifier "te\st" is exactly the same identifier as "test".

Comprehensive list: Unicode Character 'DOWNWARDS ARROW' (U+2193).

Regex to remove letters, symbols except numbers

If you want to keep only numbers then use /[^0-9]+/ instead of /[^a-zA-Z]+/

Best way to encode Degree Celsius symbol into web page?

Add a metatag to your header

<meta http-equiv="Content-Type" content="text/html;charset=utf-8" />

This expands the amount of characters you can use.

Is there Unicode glyph Symbol to represent "Search"

Use the ? symbol (encoded as &#9906; or &#x26B2;), and rotate it to achieve the desired effect:

<div style="-webkit-transform: rotate(45deg); 
               -moz-transform: rotate(45deg); 
                 -o-transform: rotate(45deg);
                    transform: rotate(45deg);">
    &#9906;
</div>

It rotates a symbol :)

HTML for the Pause symbol in audio and video control

I'm using ▐ ▌

HTML: &#9616;&nbsp;&#9612;

CSS: \2590\A0\258C

Meaning of *& and **& in C++

That is taking the parameter by reference. So in the first case you are taking a pointer parameter by reference so whatever modification you do to the value of the pointer is reflected outside the function. Second is the simlilar to first one with the only difference being that it is a double pointer. See this example:

void pass_by_value(int* p)
{
    //Allocate memory for int and store the address in p
    p = new int;
}

void pass_by_reference(int*& p)
{
    p = new int;
}

int main()
{
    int* p1 = NULL;
    int* p2 = NULL;

    pass_by_value(p1); //p1 will still be NULL after this call
    pass_by_reference(p2); //p2 's value is changed to point to the newly allocate memory

    return 0;
}

How to count instances of character in SQL Column

If you want to count the number of instances of strings with more than a single character, you can either use the previous solution with regex, or this solution uses STRING_SPLIT, which I believe was introduced in SQL Server 2016. Also you’ll need compatibility level 130 and higher.

ALTER DATABASE [database_name] SET COMPATIBILITY_LEVEL = 130

.

--some data
DECLARE @table TABLE (col varchar(500))
INSERT INTO @table SELECT 'whaCHAR(10)teverCHAR(10)whateverCHAR(10)'
INSERT INTO @table SELECT 'whaCHAR(10)teverwhateverCHAR(10)'
INSERT INTO @table SELECT 'whaCHAR(10)teverCHAR(10)whateverCHAR(10)~'

--string to find
DECLARE @string varchar(100) = 'CHAR(10)'

--select
SELECT 
    col
  , (SELECT COUNT(*) - 1 FROM STRING_SPLIT (REPLACE(REPLACE(col, '~', ''), 'CHAR(10)', '~'), '~')) AS 'NumberOfBreaks'
FROM @table

How do I list the symbols in a .so file

nm -g list the extern variable, which is not necessary exported symbol. Any non-static file scope variable(in C) are all extern variable.

nm -D will list the symbol in the dynamic table, which you can find it's address by dlsym.

nm --version

GNU nm 2.17.50.0.6-12.el5 20061020

How to change facet labels?

I feel like I should add my answer to this because it took me quite long to make this work:

This answer is for you if:

  • you do not want to edit your original data
  • if you need expressions (bquote) in your labels and
  • if you want the flexibility of a separate labelling name-vector

I basically put the labels in a named vector so labels would not get confused or switched. The labeller expression could probably be simpler, but this at least works (improvements are very welcome). Note the ` (back quotes) to protect the facet-factor.

n <- 10
x <- seq(0, 300, length.out = n)

# I have my data in a "long" format
my_data <- data.frame(
  Type = as.factor(c(rep('dl/l', n), rep('alpha', n))),
  T = c(x, x),
  Value = c(x*0.1, sqrt(x))
)

# the label names as a named vector
type_names <- c(
  `nonsense` = "this is just here because it looks good",
  `dl/l` = Linear~Expansion~~Delta*L/L[Ref]~"="~"[%]", # bquote expression
  `alpha` = Linear~Expansion~Coefficient~~alpha~"="~"[1/K]"
  )


ggplot() + 
  geom_point(data = my_data, mapping = aes(T, Value)) + 
  facet_wrap(. ~ Type, scales="free_y", 
             labeller = label_bquote(.(as.expression(
               eval(parse(text = paste0('type_names', '$`', Type, '`')))
               )))) +
  labs(x="Temperature [K]", y="", colour = "") +
  theme(legend.position = 'none')

enter image description here

Enums in Javascript with ES6

You can check Enumify, a very good and well featured library for ES6 enums.

How do you do the "therefore" (?) symbol on a Mac or in Textmate?

From System Preferences, turn on the "Show Keyboard & Character Viewer in menu bar" setting.

Then, the "Character Viewer" menu will pop up a tool that will let you search for any unicode character (by name) and insert it ? you're all set.

Undefined Symbols for architecture x86_64: Compiling problems

There's no mystery here, the linker is telling you that you haven't defined the missing symbols, and you haven't.

Similarity::Similarity() or Similarity::~Similarity() are just missing and you have defined the others incorrectly,

void Similarity::readData(Scanner& inStream){
}

not

void readData(Scanner& inStream){
}

etc. etc.

The second one is a function called readData, only the first is the readData method of the Similarity class.

To be clear about this, in Similarity.h

void readData(Scanner& inStream);

but in Similarity.cpp

void Similarity::readData(Scanner& inStream){
}

Displaying the Indian currency symbol on a website

Please try the following solution:

<span style='font-family:Arial;'>&#8377;</span>

This will be displayed as : ₹

What characters can be used for up/down triangle (arrow without stem) for display in HTML?

This one seems to imply that 030 and 031 are up and down triangles.

(As bobince pointed out, this doesn't seem to be an ASCII standard)

Unfamiliar symbol in algorithm: what does ? mean?

In math, ? means FOR ALL.

Unicode character (\u2200, ?).

OSError - Errno 13 Permission denied

This may also happen if you have a slash before the folder name:

path = '/folder1/folder2'

OSError: [Errno 13] Permission denied: '/folder1'

comes up with an error but this one works fine:

path = 'folder1/folder2'

Count number of rows within each group

Following @Joshua's suggestion, here's one way you might count the number of observations in your df dataframe where Year = 2007 and Month = Nov (assuming they are columns):

nrow(df[,df$YEAR == 2007 & df$Month == "Nov"])

and with aggregate, following @GregSnow:

aggregate(x ~ Year + Month, data = df, FUN = length)

Remove Project from Android Studio

The project can be removed from the "recent project" list but it will still remain in the project directory. To remove from the project list:

  1. Close the project
  2. Highlight the project in the "recent project" list
  3. Press Backspace (NOT Delete!)

To completely remove the project:

  1. List item
  2. Use Windows File Explorer to navigate to the Android Studio project directory (normally in "x:\Users\YourName\AndroidStudioProjects")
  3. Select the project to delete
  4. Press Delete (NOT Backspace!)

<embed> vs. <object>

OBJECT vs. EMBED - why not always use embed?

Bottom line: OBJECT is Good, EMBED is Old. Beside's IE's PARAM tags, any content between OBJECT tags will get rendered if the browser doesn't support OBJECT's referred plugin, and apparently, the content gets http requested regardless if it gets rendered or not.

object is the current standard tag to embed something on a page. embed was included by Netscape (along img) before anything like object were on the w3c mind.

This is how you include a PDF with object:

<object data="data/test.pdf" type="application/pdf" width="300" height="200">
  alt : <a href="data/test.pdf">test.pdf</a>
</object>

If you really need the inline PDF to show in almost every browser, as older browsers understand embed but not object, you'll need to do this:

<object data="abc.pdf" type="application/pdf">
    <embed src="abc.pdf" type="application/pdf" />
</object>

This version does not validate.

Interface naming in Java

Bob Lee said once in a presentation:

whats the point of an interface if you have only one implementation.

so, you start off with one implementation i.e. without an interface. later on you decide, well, there is a need for an interface here, so you convert your class to an interface.

then it becomes obvious: your original class was called User. your interface is now called User. maybe you have a UserProdImpl and a UserTestImpl. if you designed your application well, every class (except the ones that instantiate User) will be unchanged and will not notice that suddenly they get passed an interface.

so it gets clear -> Interface User implementation UserImpl.

when I run mockito test occurs WrongTypeOfReturnValue Exception

This is my case:

//given
ObjectA a = new ObjectA();
ObjectB b = mock(ObjectB.class);
when(b.call()).thenReturn(a);

Target target = spy(new Target());
doReturn(b).when(target).method1();

//when
String result = target.method2();

Then I get this error:

org.mockito.exceptions.misusing.WrongTypeOfReturnValue: 
ObjectB$$EnhancerByMockitoWithCGLIB$$2eaf7d1d cannot be returned by method2()
method2() should return String

Can you guess?

The problem is that Target.method1() is a static method. Mockito completely warns me to another thing.

hibernate: LazyInitializationException: could not initialize proxy

I think Piko means in his response that there is the hbm file. I have a file called Tax.java. The mapping information are saved in the hbm (=hibernate mapping) file. In the class tag there is a property called lazy. Set that property to true. The following hbm example shows a way to set the lazy property to false.

` id ...'

If you are using Annotations instead look in the hibernate documenation. http://docs.jboss.org/hibernate/stable/annotations/reference/en/html_single/

I hope that helped.

Use JsonReader.setLenient(true) to accept malformed JSON at line 1 column 1 path $

Also this issue occurres when the response contenttype is not application/json. In my case response contenttype was text/html and i faced this problem. I changed it to application/json then it worked.

Using async/await with a forEach loop

it's pretty painless to pop a couple methods in a file that will handle asynchronous data in a serialized order and give a more conventional flavour to your code. For example:

module.exports = function () {
  var self = this;

  this.each = async (items, fn) => {
    if (items && items.length) {
      await Promise.all(
        items.map(async (item) => {
          await fn(item);
        }));
    }
  };

  this.reduce = async (items, fn, initialValue) => {
    await self.each(
      items, async (item) => {
        initialValue = await fn(initialValue, item);
      });
    return initialValue;
  };
};

now, assuming that's saved at './myAsync.js' you can do something similar to the below in an adjacent file:

...
/* your server setup here */
...
var MyAsync = require('./myAsync');
var Cat = require('./models/Cat');
var Doje = require('./models/Doje');
var example = async () => {
  var myAsync = new MyAsync();
  var doje = await Doje.findOne({ name: 'Doje', noises: [] }).save();
  var cleanParams = [];

  // FOR EACH EXAMPLE
  await myAsync.each(['bork', 'concern', 'heck'], 
    async (elem) => {
      if (elem !== 'heck') {
        await doje.update({ $push: { 'noises': elem }});
      }
    });

  var cat = await Cat.findOne({ name: 'Nyan' });

  // REDUCE EXAMPLE
  var friendsOfNyanCat = await myAsync.reduce(cat.friends,
    async (catArray, friendId) => {
      var friend = await Friend.findById(friendId);
      if (friend.name !== 'Long cat') {
        catArray.push(friend.name);
      }
    }, []);
  // Assuming Long Cat was a friend of Nyan Cat...
  assert(friendsOfNyanCat.length === (cat.friends.length - 1));
}

Sort Pandas Dataframe by Date

You can use pd.to_datetime() to convert to a datetime object. It takes a format parameter, but in your case I don't think you need it.

>>> import pandas as pd
>>> df = pd.DataFrame( {'Symbol':['A','A','A'] ,
    'Date':['02/20/2015','01/15/2016','08/21/2015']})
>>> df
         Date Symbol
0  02/20/2015      A
1  01/15/2016      A
2  08/21/2015      A
>>> df['Date'] =pd.to_datetime(df.Date)
>>> df.sort('Date') # This now sorts in date order
        Date Symbol
0 2015-02-20      A
2 2015-08-21      A
1 2016-01-15      A

For future search, you can change the sort statement:

>>> df.sort_values(by='Date') # This now sorts in date order
        Date Symbol
0 2015-02-20      A
2 2015-08-21      A
1 2016-01-15      A

How to plot multiple functions on the same figure, in Matplotlib?

To plot multiple graphs on the same figure you will have to do:

from numpy import *
import math
import matplotlib.pyplot as plt

t = linspace(0, 2*math.pi, 400)
a = sin(t)
b = cos(t)
c = a + b

plt.plot(t, a, 'r') # plotting t, a separately 
plt.plot(t, b, 'b') # plotting t, b separately 
plt.plot(t, c, 'g') # plotting t, c separately 
plt.show()

enter image description here

String concatenation in Jinja

If you can't just use filter join but need to perform some operations on the array's entry:

{% for entry in array %}
User {{ entry.attribute1 }} has id {{ entry.attribute2 }}
{% if not loop.last %}, {% endif %}
{% endfor %}

Different ways of loading a file as an InputStream

Use MyClass.class.getClassLoader().getResourceAsStream(path) to load resource associated with your code. Use MyClass.class.getResourceAsStream(path) as a shortcut, and for resources packaged within your class' package.

Use Thread.currentThread().getContextClassLoader().getResourceAsStream(path) to get resources that are part of client code, not tightly bounds to the calling code. You should be careful with this as the thread context class loader could be pointing at anything.

Spring Boot access static resources missing scr/main/resources

You can use following code to read file in String from resource folder.

final Resource resource = new ClassPathResource("public.key");
String publicKey = null;
try {
     publicKey = new String(Files.readAllBytes(resource.getFile().toPath()), StandardCharsets.UTF_8);
} catch (IOException e) {
     e.printStackTrace();
}

How do I specify new lines on Python, when writing on files?

As mentioned in other answers: "The new line character is \n. It is used inside a string".

I found the most simple and readable way is to use the "format" function, using nl as the name for a new line, and break the string you want to print to the exact format you going to print it:

python2:

print("line1{nl}"
      "line2{nl}"
      "line3".format(nl="\n"))

python3:

nl = "\n"
print(f"line1{nl}"
      f"line2{nl}"
      f"line3")

That will output:

line1
line2
line3

This way it performs the task, and also gives high readability of the code :)

How to convert a String to JsonObject using gson library

String emailData = {"to": "[email protected]","subject":"User details","body": "The user has completed his training"
}

// Java model class
public class EmailData {
    public String to;
    public String subject;
    public String body;
}

//Final Data
Gson gson = new Gson();  
EmailData emaildata = gson.fromJson(emailData, EmailData.class);

"The system cannot find the file specified" when running C++ program

if vs2010 installed correctly

check file type (.cpp)

just build it again It will automatically fix,, ( if you are using VS 2010 )

OperationalError: database is locked

In my case, I added a new record manually saved and again through shell tried to add new record this time it works perfectly check it out.

In [7]: from main.models import Flight

In [8]: f = Flight(origin="Florida", destination="Alaska", duration=10)

In [9]: f.save()

In [10]: Flight.objects.all() 
Out[10]: <QuerySet [<Flight: Flight object (1)>, <Flight: Flight object (2)>, <Flight: Flight object (3)>, <Flight: Flight object (4)>]>

How to get All input of POST in Laravel

There seems to be a major mistake in almost all the current answers in that they show BOTH GET and POST data. Not ONLY POST data.

The issue with your code as the accepted answer mentioned is that you did not import the facade. This can imported by adding the following at the top:

use Request;

public function add_question(Request $request)
{
    return Request::post();
}

You can also use the global request method like so (mentioned by @Canaan Etai), with no import required:

request()->post();

However, a better approach to importing Request in a controller method is by dependency injection as mentioned in @shuvrow answer:

use Illuminate\Http\Request;

public function add_question(Request $request)
{
    return $request->post();
}

More information about DI can be found here:

In either case, you should use:

// Show only POST data
$request->post(); // DI
request()->post(); // global method
Request::post(); // facade

// Show only GET data
$request->query(); // DI
request()->query(); // global method
Request::query(); // facade

// Show all data (i.e. both GET and POST data)
$request->all(); // DI
request()->all(); // global method
Request::all(); // facade

How can I control Chromedriver open window size?

Ruby version:

caps = Selenium::WebDriver::Remote::Capabilities.chrome("chromeOptions" => {"args"=> ["--window-size=1280,960"]})

url = "http://localhost:9515"  # if you are using local chrome or url = Browserstack/ saucelabs hub url if you are using cloud service providers.

 Selenium::WebDriver.for(:remote, :url => url, :desired_capabilities => caps)

resize chrome is buggy in latest chromedrivers , it fails intermittanly with this failure message.

                        unknown error: cannot get automation extension
from timeout: cannot determine loading status
from timeout: Timed out receiving message from renderer: -65.294
  (Session info: chrome=56.0.2924.76)
  (Driver info: chromedriver=2.28.455517 (2c6d2707d8ea850c862f04ac066724273981e88f)

And resizeTo via javascript also not supported for chrome started via selenium webdriver. So the last option was using command line switches.

TabLayout tab selection

With the TabLayout provided by the Material Components Library just use the selectTab method:

TabLayout tabLayout = findViewById(R.id.tab_layout);
tabLayout.selectTab(tabLayout.getTabAt(index));

enter image description here

It requires version 1.1.0.

How to set some xlim and ylim in Seaborn lmplot facetgrid

The lmplot function returns a FacetGrid instance. This object has a method called set, to which you can pass key=value pairs and they will be set on each Axes object in the grid.

Secondly, you can set only one side of an Axes limit in matplotlib by passing None for the value you want to remain as the default.

Putting these together, we have:

g = sns.lmplot('X', 'Y', df, col='Z', sharex=False, sharey=False)
g.set(ylim=(0, None))

enter image description here

Where can I set environment variables that crontab will use?

You can also prepend your command with env to inject Environment variables like so:

0 * * * *   env VARIABLE=VALUE /usr/bin/mycommand

Print a div content using Jquery

<div id='printarea'>
    <p>This is a sample text for printing purpose.</p> 
</div>
<input type='button' id='btn' value='Print' onlick="printDiv()">
<p>Do not print.</p>

function printDiv(){
        var printContents = document.getElementById("printarea").innerHTML;
        var originalContents = document.body.innerHTML;
        document.body.innerHTML = printContents;
        window.print();
        document.body.innerHTML = originalContents;
}

This Above function should be load on same page.

How do you set the document title in React?

React Portals can let you render to elements outside the root React node (such at <title>), as if they were actual React nodes. So now you can set the title cleanly and without any additional dependencies:

Here's an example:

import React, { Component } from 'react';
import ReactDOM from 'react-dom';

class Title extends Component {
    constructor(props) {
        super(props);
        this.titleEl = document.getElementsByTagName("title")[0];
    }

    render() {
        let fullTitle;
        if(this.props.pageTitle) {
            fullTitle = this.props.pageTitle + " - " + this.props.siteTitle;
        } else {
            fullTitle = this.props.siteTitle;
        }

        return ReactDOM.createPortal(
            fullTitle || "",
            this.titleEl
        );
    }
}
Title.defaultProps = {
    pageTitle: null,
    siteTitle: "Your Site Name Here",
};

export default Title;

Just put the component in the page and set pageTitle:

<Title pageTitle="Dashboard" />
<Title pageTitle={item.name} />

Best way to display data via JSON using jQuery

JQuery has an inbuilt json data type for Ajax and converts the data into a object. PHP% also has inbuilt json_encode function which converts an array into json formatted string. Saves a lot of parsing, decoding effort.

jQuery - Redirect with post data

This needs clarification. Is your server handling a POST that you want to redirect somewhere else? Or are you wanting to redirect a regulatr GET request to another page that is expecting a POST?

In either case what you can do is something like this:

var f = $('<form>');
$('<input>').attr('name', '...').attr('value', '...');
//after all fields are added
f.submit();

It's probably a good idea to make a link that says "click here if not automatically redirected" to deal with pop-up blockers.

Correct way to try/except using Python requests module?

Have a look at the Requests exception docs. In short:

In the event of a network problem (e.g. DNS failure, refused connection, etc), Requests will raise a ConnectionError exception.

In the event of the rare invalid HTTP response, Requests will raise an HTTPError exception.

If a request times out, a Timeout exception is raised.

If a request exceeds the configured number of maximum redirections, a TooManyRedirects exception is raised.

All exceptions that Requests explicitly raises inherit from requests.exceptions.RequestException.

To answer your question, what you show will not cover all of your bases. You'll only catch connection-related errors, not ones that time out.

What to do when you catch the exception is really up to the design of your script/program. Is it acceptable to exit? Can you go on and try again? If the error is catastrophic and you can't go on, then yes, you may abort your program by raising SystemExit (a nice way to both print an error and call sys.exit).

You can either catch the base-class exception, which will handle all cases:

try:
    r = requests.get(url, params={'s': thing})
except requests.exceptions.RequestException as e:  # This is the correct syntax
    raise SystemExit(e)

Or you can catch them separately and do different things.

try:
    r = requests.get(url, params={'s': thing})
except requests.exceptions.Timeout:
    # Maybe set up for a retry, or continue in a retry loop
except requests.exceptions.TooManyRedirects:
    # Tell the user their URL was bad and try a different one
except requests.exceptions.RequestException as e:
    # catastrophic error. bail.
    raise SystemExit(e)

As Christian pointed out:

If you want http errors (e.g. 401 Unauthorized) to raise exceptions, you can call Response.raise_for_status. That will raise an HTTPError, if the response was an http error.

An example:

try:
    r = requests.get('http://www.google.com/nothere')
    r.raise_for_status()
except requests.exceptions.HTTPError as err:
    raise SystemExit(err)

Will print:

404 Client Error: Not Found for url: http://www.google.com/nothere

What are some ways of accessing Microsoft SQL Server from Linux?

There is an abstraction lib available for PHP. Not sure what your client's box will support but if its Linux then certainly should support building a PHP query interface with this: http://adodb.sourceforge.net/ Hope that helps you.

A simple algorithm for polygon intersection

Here's a simple-and-stupid approach: on input, discretize your polygons into a bitmap. To intersect, AND the bitmaps together. To produce output polygons, trace out the jaggy borders of the bitmap and smooth the jaggies using a polygon-approximation algorithm. (I don't remember if that link gives the most suitable algorithms, it's just the first Google hit. You might check out one of the tools out there to convert bitmap images to vector representations. Maybe you could call on them without reimplementing the algorithm?)

The most complex part would be tracing out the borders, I think.

Back in the early 90s I faced something like this problem at work, by the way. I muffed it: I came up with a (completely different) algorithm that would work on real-number coordinates, but seemed to run into a completely unfixable plethora of degenerate cases in the face of the realities of floating-point (and noisy input). Perhaps with the help of the internet I'd have done better!

Java correct way convert/cast object to Double

new Double(object.toString());

But it seems weird to me that you're going from an Object to a Double. You should have a better idea what class of object you're starting with before attempting a conversion. You might have a bit of a code quality problem there.

Note that this is a conversion, not casting.

How to run code after some delay in Flutter?

await Future.delayed(Duration(milliseconds: 1000));

Javascript set img src

Wow! when you use src then src of searchPic must be used also.

document["pic1"].src = searchPic.src

looks better

How do I make a relative reference to another workbook in Excel?

In Excel, there is a way to embed relative reference to file or directory. You can try type in excel cell : =HYPERLINK("..\Name_of_file_or_folder\","DisplayLinkName")

How can I append a string to an existing field in MySQL?

You need to use the CONCAT() function in MySQL for string concatenation:

UPDATE categories SET code = CONCAT(code, '_standard') WHERE id = 1;

How to get row number from selected rows in Oracle

There is no inherent ordering to a table. So, the row number itself is a meaningless metric.

However, you can get the row number of a result set by using the ROWNUM psuedocolumn or the ROW_NUMBER() analytic function, which is more powerful.

As there is no ordering to a table both require an explicit ORDER BY clause in order to work.

select rownum, a.*
  from ( select *
           from student
          where name like '%ram%'
          order by branch
                ) a

or using the analytic query

select row_number() over ( order by branch ) as rnum, a.*
  from student
 where name like '%ram%'

Your syntax where name is like ... is incorrect, there's no need for the IS, so I've removed it.

The ORDER BY here relies on a binary sort, so if a branch starts with anything other than B the results may be different, for instance b is greater than B.

Converting video to HTML5 ogg / ogv and mpg4

The Miro video converter does a beautiful job and is drag-n-drop. http://www.mirovideoconverter.com/

BTW it's FREE and also very good for mobile device encoding.

convert HTML ( having Javascript ) to PDF using JavaScript

You can do it using a jquery,

Use this code to link the button...

$(document).ready(function() {
    $("#button_id").click(function() {
        window.print();
        return false;
    });
});

This link may be also helpful: jQuery Print HTML Pdf Page Options Link

Best way to find os name and version in Unix/Linux platform

this command gives you a description of your operating system

cat /etc/os-release

java.lang.NoSuchMethodError: javax.servlet.ServletContext.getContextPath()Ljava/lang/String;

java.lang.NoSuchMethodError: javax.servlet.ServletContext.getContextPath()Ljava/lang/String;

That method was added in Servlet 2.5.

So this problem can have at least 3 causes:

  1. The servlet container does not support Servlet 2.5.
  2. The web.xml is not declared conform Servlet 2.5 or newer.
  3. The webapp's runtime classpath is littered with servlet container specific JAR files of a different servlet container make/version which does not support Servlet 2.5.

To solve it,

  1. Make sure that your servlet container supports at least Servlet 2.5. That are at least Tomcat 6, Glassfish 2, JBoss AS 4.1, etcetera. Tomcat 5.5 for example supports at highest Servlet 2.4. If you can't upgrade Tomcat, then you'd need to downgrade Spring to a Servlet 2.4 compatible version.
  2. Make sure that the root declaration of web.xml complies Servlet 2.5 (or newer, at least the highest whatever your target runtime supports). For an example, see also somewhere halfway our servlets wiki page.
  3. Make sure that you don't have any servlet container specific libraries like servlet-api.jar or j2ee.jar in /WEB-INF/lib or even worse, the JRE/lib or JRE/lib/ext. They do not belong there. This is a pretty common beginner's mistake in an attempt to circumvent compilation errors in an IDE, see also How do I import the javax.servlet API in my Eclipse project?.

ImportError: No module named PyQt4

You have to check which Python you are using. I had the same problem because the Python I was using was not the same one that brew was using. In your command line:

  1. which python
    output: /usr/bin/python
  2. which brew
    output: /usr/local/bin/brew     //so they are different
  3. cd /usr/local/lib/python2.7/site-packages
  4. ls   //you can see PyQt4 and sip are here
  5. Now you need to add usr/local/lib/python2.7/site-packages to your python path.
  6. open ~/.bash_profile   //you will open your bash_profile file in your editor
  7. Add 'export PYTHONPATH=/usr/local/lib/python2.7/site-packages:$PYTHONPATH' to your bash file and save it
  8. Close your terminal and restart it to reload the shell
  9. python
  10. import PyQt4    // it is ok now

What port is used by Java RMI connection?

With reference to other answers above, here is my view -

there are ports involved on both client and server side.

  • for server/remote side, if you export the object without providing a port , remote object would use a random port to listen.

  • a client, when looks up the remote object, it would always use a random port on its side and will connect to the remote object port as listed above.

get next and previous day with PHP

You could use 'now' as string to get today's/tomorrow's/yesterday's date:

$previousDay = date('Y-m-d', strtotime('now - 1day'));
$toDay       = date('Y-m-d', strtotime('now'));
$nextDay     = date('Y-m-d', strtotime('now + 1day'));

ERROR 403 in loading resources like CSS and JS in my index.php

You need to change permissions on the folder bootstrap/css. Your super user may be able to access it but it doesn't mean apache or nginx have access to it, that's why you still need to change the permissions.

Tip: I usually make the apache/nginx's user group owner of that kind of folders and give 775 permission to it.

How to apply a CSS class on hover to dynamically generated submit buttons?

Add the below code

input[type="submit"]:hover {
    border: 1px solid #999;
    color: #000;
}

If you need only for these button then you can add id name

#paginate input[type="submit"]:hover {
    border: 1px solid #999;
    color: #000;
}

DEMO

How to make a class property?

I happened to come up with a solution very similar to @Andrew, only DRY

class MetaFoo(type):

    def __new__(mc1, name, bases, nmspc):
        nmspc.update({'thingy': MetaFoo.thingy})
        return super(MetaFoo, mc1).__new__(mc1, name, bases, nmspc)

    @property
    def thingy(cls):
        if not inspect.isclass(cls):
            cls = type(cls)
        return cls._thingy

    @thingy.setter
    def thingy(cls, value):
        if not inspect.isclass(cls):
            cls = type(cls)
        cls._thingy = value

class Foo(metaclass=MetaFoo):
    _thingy = 23

class Bar(Foo)
    _thingy = 12

This has the best of all answers:

The "metaproperty" is added to the class, so that it will still be a property of the instance

  1. Don't need to redefine thingy in any of the classes
  2. The property works as a "class property" in for both instance and class
  3. You have the flexibility to customize how _thingy is inherited

In my case, I actually customized _thingy to be different for every child, without defining it in each class (and without a default value) by:

   def __new__(mc1, name, bases, nmspc):
       nmspc.update({'thingy': MetaFoo.services, '_thingy': None})
       return super(MetaFoo, mc1).__new__(mc1, name, bases, nmspc)

Angular2 - Input Field To Accept Only Numbers

You can create this Validator and import it in your component.
Basically validates the form input string:

  • check there is no dot
  • converts string to number
  • check is an integer
  • check is greater than zero

To implement it in your project:

  1. suggested path in your app folder: src/app/validators/number.validator.ts
  2. import in your component

    import { NumberValidator } from '../../validators/number.validator';

  3. add it to the form control
    inputNumber: ['', [NumberValidator.isInteger]],
  4. if you dont want to show the invalid char, bind a (change)="deleteCharIfInvalid()" to the input, if form.get('inputNumber').hasError('isInteger') is true, delete the last char inserted.
// FILE: src/app/validators/number.validator.ts

import { FormControl } from '@angular/forms';

export interface ValidationResult {
    [key: string]: boolean;
}

export class NumberValidator {

    public static isInteger(control: FormControl): ValidationResult {
        // check if string has a dot
        let hasDot:boolean = control.value.indexOf('.') >= 0 ? true : false;
        // convert string to number
        let number:number = Math.floor(control.value);
        // get result of isInteger()
        let integer:boolean = Number.isInteger(number);
        // validate conditions 
        let valid:boolean = !hasDot && integer && number>0;
        console.log('isInteger > valid', hasDot, number, valid);
        if (!valid) {
            return { isInteger: true };
        }
        return null;
    }        
}

How to use [DllImport("")] in C#?

You can't declare an extern local method inside of a method, or any other method with an attribute. Move your DLL import into the class:

using System.Runtime.InteropServices;


public class WindowHandling
{
    [DllImport("User32.dll")]
    public static extern int SetForegroundWindow(IntPtr point);

    public void ActivateTargetApplication(string processName, List<string> barcodesList)
    {
        Process p = Process.Start("notepad++.exe");
        p.WaitForInputIdle();
        IntPtr h = p.MainWindowHandle;
        SetForegroundWindow(h);
        SendKeys.SendWait("k");
        IntPtr processFoundWindow = p.MainWindowHandle;
    }
}

Java - How do I make a String array with values?

Another way is with Arrays.setAll, or Arrays.fill:

String[] v = new String[1000];
Arrays.setAll(v, i -> Integer.toString(i * 30));
//v => ["0", "30", "60", "90"... ]

Arrays.fill(v, "initial value");
//v => ["initial value", "initial value"... ]

This is more usefull for initializing (possibly large) arrays where you can compute each element from its index.

CronJob not running

Sometimes the command that cron needs to run is in a directory where cron has no access, typically on systems where users' home directories' permissions are 700 and the command is in that directory.

$(document).ready shorthand

The correct shorthand is this:

$(function() {
    // this behaves as if within document.ready
});

The code you posted…

(function($){

//some code

})(jQuery);

…creates an anonymous function and executes it immediately with jQuery being passed in as the arg $. All it effectively does is take the code inside the function and execute it like normal, since $ is already an alias for jQuery. :D

Iif equivalent in C#

Also useful is the coalesce operator ??:

VB:

Return Iif( s IsNot Nothing, s, "My Default Value" )

C#:

return s ?? "My Default Value";

jQuery 1.9 .live() is not a function

jQuery .live() has been removed in version 1.9 onwards.

That means if you are upgrading from version 1.8 and earlier, you will notice things breaking if you do not follow the migration guide below. You must not simply replace .live() with .on()!


Read before you start doing a search and replace:

For quick/hot fixes on a live site, do not just replace the keyword live with on,
as the parameters are different!

.live(events, function)

should map to:

.on(eventType, selector, function)

The (child) selector is very important! If you do not need to use this for any reason, set it to null.


Migration Example 1:

before:

$('#mainmenu a').live('click', function)

after, you move the child element (a) to the .on() selector:

$('#mainmenu').on('click', 'a', function)

Migration Example 2:

before:

$('.myButton').live('click', function)

after, you move the element (.myButton) to the .on() selector, and find the nearest parent element (preferably with an ID):

$('#parentElement').on('click', '.myButton', function)

If you do not know what to put as the parent, body always works:

$('body').on('click', '.myButton', function)

See also:

fe_sendauth: no password supplied

This occurs if the password for the database is not given.

default="postgres://postgres:[email protected]:5432/DBname"

How to query all the GraphQL type fields without writing a long query?

Package graphql-type-json supports custom-scalars type JSON. Use it can show all the field of your json objects. Here is the link of the example in ApolloGraphql Server. https://www.apollographql.com/docs/apollo-server/schema/scalars-enums/#custom-scalars

Image size (Python, OpenCV)

You can use image.shape to get the dimensions of the image. It returns 3 values. First value is width of an image, second is height and last one is channel. You dont need last value here so you can use below code to get height and width of image:

width, height = src.shape[:2]<br>
print(width, height)

Docker-Compose persistent data MySQL

first, you need to delete all old mysql data using

docker-compose down -v

after that add two lines in your docker-compose.yml

volumes:
  - mysql-data:/var/lib/mysql

and

volumes:
  mysql-data:

your final docker-compose.yml will looks like

version: '3.1'

services:
  php:
    build:
      context: .
      dockerfile: Dockerfile
    ports:
      - 80:80
    volumes:
      - ./src:/var/www/html/
  db:
    image: mysql
    command: --default-authentication-plugin=mysql_native_password
    restart: always
    environment:
      MYSQL_ROOT_PASSWORD: example
    volumes:
      - mysql-data:/var/lib/mysql

  adminer:
    image: adminer
    restart: always
    ports:
      - 8080:8080
volumes:
  mysql-data:

after that use this command

docker-compose up -d

now your data will persistent and will not be deleted even after using this command

docker-compose down

extra:- but if you want to delete all data then you will use

docker-compose down -v

Python: Get HTTP headers from urllib2.urlopen call?

Actually, it appears that urllib2 can do an HTTP HEAD request.

The question that @reto linked to, above, shows how to get urllib2 to do a HEAD request.

Here's my take on it:

import urllib2

# Derive from Request class and override get_method to allow a HEAD request.
class HeadRequest(urllib2.Request):
    def get_method(self):
        return "HEAD"

myurl = 'http://bit.ly/doFeT'
request = HeadRequest(myurl)

try:
    response = urllib2.urlopen(request)
    response_headers = response.info()

    # This will just display all the dictionary key-value pairs.  Replace this
    # line with something useful.
    response_headers.dict

except urllib2.HTTPError, e:
    # Prints the HTTP Status code of the response but only if there was a 
    # problem.
    print ("Error code: %s" % e.code)

If you check this with something like the Wireshark network protocol analazer, you can see that it is actually sending out a HEAD request, rather than a GET.

This is the HTTP request and response from the code above, as captured by Wireshark:

HEAD /doFeT HTTP/1.1
Accept-Encoding: identity
Host: bit.ly
Connection: close
User-Agent: Python-urllib/2.7

HTTP/1.1 301 Moved
Server: nginx
Date: Sun, 19 Feb 2012 13:20:56 GMT
Content-Type: text/html; charset=utf-8
Cache-control: private; max-age=90
Location: http://www.kidsidebyside.org/?p=445
MIME-Version: 1.0
Content-Length: 127
Connection: close
Set-Cookie: _bit=4f40f738-00153-02ed0-421cf10a;domain=.bit.ly;expires=Fri Aug 17 13:20:56 2012;path=/; HttpOnly

However, as mentioned in one of the comments in the other question, if the URL in question includes a redirect then urllib2 will do a GET request to the destination, not a HEAD. This could be a major shortcoming, if you really wanted to only make HEAD requests.

The request above involves a redirect. Here is request to the destination, as captured by Wireshark:

GET /2009/05/come-and-draw-the-circle-of-unity-with-us/ HTTP/1.1
Accept-Encoding: identity
Host: www.kidsidebyside.org
Connection: close
User-Agent: Python-urllib/2.7

An alternative to using urllib2 is to use Joe Gregorio's httplib2 library:

import httplib2

url = "http://bit.ly/doFeT"
http_interface = httplib2.Http()

try:
    response, content = http_interface.request(url, method="HEAD")
    print ("Response status: %d - %s" % (response.status, response.reason))

    # This will just display all the dictionary key-value pairs.  Replace this
    # line with something useful.
    response.__dict__

except httplib2.ServerNotFoundError, e:
    print (e.message)

This has the advantage of using HEAD requests for both the initial HTTP request and the redirected request to the destination URL.

Here's the first request:

HEAD /doFeT HTTP/1.1
Host: bit.ly
accept-encoding: gzip, deflate
user-agent: Python-httplib2/0.7.2 (gzip)

Here's the second request, to the destination:

HEAD /2009/05/come-and-draw-the-circle-of-unity-with-us/ HTTP/1.1
Host: www.kidsidebyside.org
accept-encoding: gzip, deflate
user-agent: Python-httplib2/0.7.2 (gzip)

How do I make a transparent border with CSS?

You could remove the border and increase the padding:

_x000D_
_x000D_
li {_x000D_
  display: inline-block;_x000D_
  padding: 6px;_x000D_
  border-width: 0px;_x000D_
}_x000D_
_x000D_
li:hover {_x000D_
  border: 1px solid #FC0;_x000D_
  padding: 5px;_x000D_
}
_x000D_
<ul>_x000D_
  <li>Hovering is great</li>_x000D_
</ul>
_x000D_
_x000D_
_x000D_

Datatable select with multiple conditions

Dim dr As DataRow()


dr = dt.Select("A="& a & "and B="& b & "and C=" & c,"A",DataViewRowState.CurrentRows)

Where A,B,C are the column names where second parameter is for sort expression

How do I start Mongo DB from Windows?

It is showing admin web console waiting for connections on port 28017.

The above message means that mongodb has started successfully and is listening on port 28017.

You can use the mongo shell(mongo.exe) to connect to the mongoDB and perform db operations.

There are several GUI tools available for MongoDB like MongoVUE, etc.

Getting error: ISO C++ forbids declaration of with no type

Your declaration is int ttTreeInsert(int value);

However, your definition/implementation is

ttTree::ttTreeInsert(int value)
{
}

Notice that the return type int is missing in the implementation. Instead it should be

int ttTree::ttTreeInsert(int value)
{
    return 1; // or some valid int
}

Declaring & Setting Variables in a Select Statement

The SET command is TSQL specific - here's the PLSQL equivalent to what you posted:

v_date1 DATE := TO_DATE('03-AUG-2010', 'DD-MON-YYYY');

SELECT u.visualid
  FROM USAGE u 
 WHERE u.usetime > v_date1;

There's also no need for prefixing variables with "@"; I tend to prefix variables with "v_" to distinguish between variables & columns/etc.

See this thread about the Oracle equivalent of NOLOCK...

How to resolve the error on 'react-native start'

The solution is simple, but temporary...

Note that if you run an npm install or a yarn install you need to change the code again!

So, how can we run this automatically?

Permanent Solution

To do this "automagically" after installing your node modules, you can use patch-package.

  1. Fix the metro-config file, solving the error:

The file appears in \node_modules\metro-config\src\defaults\blacklist.js.

Edit from:

var sharedBlacklist = [
  /node_modules[/\\]react[/\\]dist[/\\].*/,
  /website\/node_modules\/.*/,
  /heapCapture\/bundle\.js/,
  /.*\/__tests__\/.*/
];

To:

var sharedBlacklist = [
  /node_modules[\/\\]react[\/\\]dist[\/\\].*/,
  /website\/node_modules\/.*/,
  /heapCapture\/bundle\.js/,
  /.*\/__tests__\/.*/
];
  1. Then, generate a permanent patch file:

npx patch-package metro-config

  1. In your package.json trigger the patch:
"scripts": {
+  "postinstall": "npx patch-package"
}

All done! Now this patch will be made at every npm install / yarn install.

Thanks to https://github.com/ds300/patch-package

how to determine size of tablespace oracle 11g

The following query can be used to detemine tablespace and other params:

select df.tablespace_name "Tablespace",
       totalusedspace "Used MB",
       (df.totalspace - tu.totalusedspace) "Free MB",
       df.totalspace "Total MB",
       round(100 * ( (df.totalspace - tu.totalusedspace)/ df.totalspace)) "Pct. Free"
  from (select tablespace_name,
               round(sum(bytes) / 1048576) TotalSpace
          from dba_data_files 
         group by tablespace_name) df,
       (select round(sum(bytes)/(1024*1024)) totalusedspace,
               tablespace_name
          from dba_segments 
         group by tablespace_name) tu
 where df.tablespace_name = tu.tablespace_name 
   and df.totalspace <> 0;

Source: https://community.oracle.com/message/1832920

For your case if you want to know the partition name and it's size just run this query:

select owner,
       segment_name,
       partition_name,
       segment_type,
       bytes / 1024/1024 "MB" 
  from dba_segments 
 where owner = <owner_name>;

Difference between Apache CXF and Axis

  • Axis2: More ubiquitous on the marketplace, supports more bindings, supports other languages like C/C++.
  • CXF: Much easier to use, more Spring friendly, faster got support for some WS-* extensions.

Convert pandas dataframe to NumPy array

Two ways to convert the data-frame to its Numpy-array representation.

  • mah_np_array = df.as_matrix(columns=None)

  • mah_np_array = df.values

Doc: https://pandas.pydata.org/pandas-docs/stable/generated/pandas.DataFrame.as_matrix.html

Get only the Date part of DateTime in mssql

This may not be as slick as a one-liner, but I use it to perform date manipulation mainly for reports:

DECLARE @Date datetime
SET @Date = GETDATE()

-- Set all time components to zero
SET @Date = DATEADD(ms, -DATEPART(ms, @Date), @Date) -- milliseconds = 0
SET @Date = DATEADD(ss, -DATEPART(ss, @Date), @Date) -- seconds = 0
SET @Date = DATEADD(mi, -DATEPART(mi, @Date), @Date) -- minutes = 0
SET @Date = DATEADD(hh, -DATEPART(hh, @Date), @Date) -- hours = 0

-- Extra manipulation for month and year
SET @Date = DATEADD(dd, -DATEPART(dd, @Date) + 1, @Date) -- day = 1
SET @Date = DATEADD(mm, -DATEPART(mm, @Date) + 1, @Date) -- month = 1

I use this to get hourly, daily, monthly, and yearly dates used for reporting and performance indicators, etc.

Are multiple `.gitignore`s frowned on?

You can have multiple .gitignore, each one of course in its own directory.
To check which gitignore rule is responsible for ignoring a file, use git check-ignore: git check-ignore -v -- afile.

And you can have different version of a .gitignore file per branch: I have already seen that kind of configuration for ensuring one branch ignores a file while the other branch does not: see this question for instance.

If your repo includes several independent projects, it would be best to reference them as submodules though.
That would be the actual best practices, allowing each of those projects to be cloned independently (with their respective .gitignore files), while being referenced by a specific revision in a global parent project.
See true nature of submodules for more.


Note that, since git 1.8.2 (March 2013) you can do a git check-ignore -v -- yourfile in order to see which gitignore run (from which .gitignore file) is applied to 'yourfile', and better understand why said file is ignored.
See "which gitignore rule is ignoring my file?"

PowerShell : retrieve JSON object by field value

Hows about this:

$json=Get-Content -Raw -Path 'my.json' | Out-String | ConvertFrom-Json
$foo="TheVariableYourUsingToSelectSomething"
$json.SomePathYouKnow.psobject.properties.Where({$_.name -eq $foo}).value

which would select from json structured

{"SomePathYouKnow":{"TheVariableYourUsingToSelectSomething": "Tada!"}

This is based on this accessing values in powershell SO question . Isn't powershell fabulous!

null check in jsf expression language

Use empty (it checks both nullness and emptiness) and group the nested ternary expression by parentheses (EL is in certain implementations/versions namely somewhat problematic with nested ternary expressions). Thus, so:

styleClass="#{empty obj.validationErrorMap ? ' ' :  
 (obj.validationErrorMap.contains('key') ? 'highlight_field' : 'highlight_row')}"

If still in vain (I would then check JBoss EL configs), use the "normal" EL approach:

styleClass="#{empty obj.validationErrorMap ? ' ' :  
 (obj.validationErrorMap['key'] ne null ? 'highlight_field' : 'highlight_row')}"

Update: as per the comments, the Map turns out to actually be a List (please work on your naming conventions). To check if a List contains an item the "normal" EL way, use JSTL fn:contains (although not explicitly documented, it works for List as well).

styleClass="#{empty obj.validationErrorMap ? ' ' :  
 (fn:contains(obj.validationErrorMap, 'key') ? 'highlight_field' : 'highlight_row')}"

How to update attributes without validation

You can do something like:

object.attribute = value
object.save(:validate => false)

How do I change TextView Value inside Java Code?

First, add a textView in the XML file

<TextView  
    android:id="@+id/rate_id"
    android:layout_width="fill_parent" 
    android:layout_height="wrap_content" 
    android:text="@string/what_U_want_to_display_in_first_time"
    />

then add a button in xml file with id btn_change_textView and write this two line of code in onCreate() method of activity

Button btn= (Button) findViewById(R.id. btn_change_textView);
TextView textView=(TextView)findViewById(R.id.rate_id);

then use clickListener() on button object like this

btn.setOnClickListener(new View.OnClickListener {
    public void onClick(View v) {
      
        textView.setText("write here what u want to display after button click in string");
    }
});

Removing element from array in component state

Just a suggestion,in your code instead of using let newData = prevState.data you could use spread which is introduced in ES6 that is you can uselet newData = ...prevState.data for copying array

Three dots ... represents Spread Operators or Rest Parameters,

It allows an array expression or string or anything which can be iterating to be expanded in places where zero or more arguments for function calls or elements for array are expected.

Additionally you can delete item from array with following

onRemovePerson: function(index) {
  this.setState((prevState) => ({
    data: [...prevState.data.slice(0,index), ...prevState.data.slice(index+1)]
  }))
}

Hope this contributes!!

How to create SPF record for multiple IPs?

Try this:

v=spf1 ip4:abc.de.fgh.ij ip4:klm.no.pqr.st ~all

How I can print to stderr in C?

To print your context ,you can write code like this :

FILE *fp;
char *of;
sprintf(of,"%s%s",text1,text2);
fp=fopen(of,'w');
fprintf(fp,"your print line");

How to copy a string of std::string type in C++?

Caesar's solution is the best in my opinion, but if you still insist to use the strcpy function, then after you have your strings ready:

string a = "text";
string b = "image";

You can try either:

strcpy(a.data(), b.data());

or

strcpy(a.c_str(), b.c_str());

Just call either the data() or c_str() member functions of the std::string class, to get the char* pointer of the string object.

The strcpy() function doesn't have overload to accept two std::string objects as parameters. It has only one overload to accept two char* pointers as parameters.

Both data and c_str return what does strcpy() want exactly.

How to format code in Xcode?

  1. Select the block of code that you want indented.

  2. Right-click (or, on Mac, Ctrl-click).

  3. Structure → Re-indent

using where and inner join in mysql

Try this:

SELECT Locations.Name, Schools.Name
FROM Locations
INNER JOIN School_Locations ON School_Locations.Locations_Id = Locations.Id
INNER JOIN Schools ON School.Id = Schools_Locations.School_Id
WHERE Locations.Type = "coun"

You can join Locations to School_Locations and then School_Locations to School. This forms a set of all related Locations and Schools, which you can then widdle down using the WHERE clause to those whose Location is of type "coun."

How to auto adjust the <div> height according to content in it?

Just write:

min-height: xxx;
overflow: hidden;

then div will automatically take the height of the content.

Displaying the Error Messages in Laravel after being Redirected from controller

A New Laravel Blade Error Directive comes to Laravel 5.8.13

// Before
@if ($errors->has('email'))
    <span>{{ $errors->first('email') }}</span>
@endif

// After:
@error('email')
    <span>{{ $message }}</span>
@enderror

JavaScript: Class.method vs. Class.prototype.method

Yes, the first one is a static method also called class method, while the second one is an instance method.

Consider the following examples, to understand it in more detail.

In ES5

function Person(firstName, lastName) {
   this.firstName = firstName;
   this.lastName = lastName;
}

Person.isPerson = function(obj) {
   return obj.constructor === Person;
}

Person.prototype.sayHi = function() {
   return "Hi " + this.firstName;
}

In the above code, isPerson is a static method, while sayHi is an instance method of Person.

Below, is how to create an object from Person constructor.

var aminu = new Person("Aminu", "Abubakar");

Using the static method isPerson.

Person.isPerson(aminu); // will return true

Using the instance method sayHi.

aminu.sayHi(); // will return "Hi Aminu"

In ES6

class Person {
   constructor(firstName, lastName) {
      this.firstName = firstName;
      this.lastName = lastName;
   }

   static isPerson(obj) {
      return obj.constructor === Person;
   }

   sayHi() {
      return `Hi ${this.firstName}`;
   }
}

Look at how static keyword was used to declare the static method isPerson.

To create an object of Person class.

const aminu = new Person("Aminu", "Abubakar");

Using the static method isPerson.

Person.isPerson(aminu); // will return true

Using the instance method sayHi.

aminu.sayHi(); // will return "Hi Aminu"

NOTE: Both examples are essentially the same, JavaScript remains a classless language. The class introduced in ES6 is primarily a syntactical sugar over the existing prototype-based inheritance model.

How can I get all sequences in an Oracle database?

You may not have permission to dba_sequences. So you can always just do:

select * from user_sequences;

Can't load IA 32-bit .dll on a AMD 64-bit platform

I had a problem when run red5(tomcat) on Windows x64 that previous worked under Windows x32, got next error:

 INFO pool-15-thread-1 com.home.launcher.CommandLauncher - Exception in thread "main" java.lang.UnsatisfiedLinkError: C:\....\lib\Data Samolet.dll: Can't find dependent libraries
INFO pool-15-thread-1 com.home.launcher.CommandLauncher - at java.lang.ClassLoader$NativeLibrary.load(Native Method)

Problem solved when I installed Java x32 version and set next

"Environment variables"

"User variables for Home"

JAVA_HOME => C:\Program Files (x86)\Java\jdk.1.6.0_45

"System variables"

Path[at the beginning] => C:\Program Files\Java\jdk.1.8.0_60;..

How to Check whether Session is Expired or not in asp.net

Use Session.Contents.Count:

if (Session.Contents.Count == 0)
{
    Response.Write(".NET session has Expired");
    Response.End();
}
else
{
    InitializeControls();
}

The code above assumes that you have at least one session variable created when the user first visits your site. If you don't have one then you are most likely not using a database for your app. For your case you can just manually assign a session variable using the example below.

protected void Page_Load(object sender, EventArgs e)
{
    Session["user_id"] = 1;
}

Best of luck to you!

Change placeholder text

var input = document.getElementById ("IdofInput");
input.placeholder = "No need to fill this field";

You can find out more about placeholder here: http://help.dottoro.com/ljgugboo.php

Merge/flatten an array of arrays

I recommend a space-efficient generator function:

_x000D_
_x000D_
function* flatten(arr) {_x000D_
  if (!Array.isArray(arr)) yield arr;_x000D_
  else for (let el of arr) yield* flatten(el);_x000D_
}_x000D_
_x000D_
// Example:_x000D_
console.log(...flatten([1,[2,[3,[4]]]])); // 1 2 3 4
_x000D_
_x000D_
_x000D_

If desired, create an array of flattened values as follows:

let flattened = [...flatten([1,[2,[3,[4]]]])]; // [1, 2, 3, 4]

How can I display a pdf document into a Webview?

Opening a pdf using google docs is a bad idea in terms of user experience. It is really slow and unresponsive.

Solution after API 21

Since api 21, we have PdfRenderer which helps converting a pdf to Bitmap. I've never used it but is seems easy enough.

Solution for any api level

Other solution is to download the PDF and pass it via Intent to a dedicated PDF app which will do a banger job displaying it. Fast and nice user experience, especially if this feature is not central in your app.

Use this code to download and open the PDF

public class PdfOpenHelper {

public static void openPdfFromUrl(final String pdfUrl, final Activity activity){
    Observable.fromCallable(new Callable<File>() {
        @Override
        public File call() throws Exception {
            try{
                URL url = new URL(pdfUrl);
                URLConnection connection = url.openConnection();
                connection.connect();

                // download the file
                InputStream input = new BufferedInputStream(connection.getInputStream());
                File dir = new File(activity.getFilesDir(), "/shared_pdf");
                dir.mkdir();
                File file = new File(dir, "temp.pdf");
                OutputStream output = new FileOutputStream(file);

                byte data[] = new byte[1024];
                long total = 0;
                int count;
                while ((count = input.read(data)) != -1) {
                    total += count;
                    output.write(data, 0, count);
                }

                output.flush();
                output.close();
                input.close();
                return file;
            } catch (IOException e) {
                e.printStackTrace();
            }
            return null;
        }
    })
            .subscribeOn(Schedulers.io())
            .observeOn(AndroidSchedulers.mainThread())
            .subscribe(new Subscriber<File>() {
                @Override
                public void onCompleted() {

                }

                @Override
                public void onError(Throwable e) {

                }

                @Override
                public void onNext(File file) {
                    String authority = activity.getApplicationContext().getPackageName() + ".fileprovider";
                    Uri uriToFile = FileProvider.getUriForFile(activity, authority, file);

                    Intent shareIntent = new Intent(Intent.ACTION_VIEW);
                    shareIntent.setDataAndType(uriToFile, "application/pdf");
                    shareIntent.addFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION);
                    if (shareIntent.resolveActivity(activity.getPackageManager()) != null) {
                        activity.startActivity(shareIntent);
                    }
                }
            });
}

}

For the Intent to work, you need to create a FileProvider to grant permission to the receiving app to open the file.

Here is how you implement it: In your Manifest:

    <provider
        android:name="android.support.v4.content.FileProvider"
        android:authorities="${applicationId}.fileprovider"
        android:exported="false"
        android:grantUriPermissions="true">

        <meta-data
            android:name="android.support.FILE_PROVIDER_PATHS"
            android:resource="@xml/file_paths" />

    </provider>

Finally create a file_paths.xml file in the resources foler

<?xml version="1.0" encoding="utf-8"?>
<paths>
    <files-path name="shared_pdf" path="shared_pdf"/>
</paths>

Hope this helps =)

127 Return code from $?

Generally it means:

127 - command not found

but it can also mean that the command is found,
but a library that is required by the command is NOT found.

Change navbar color in Twitter Bootstrap

In this navbar CSS, set to own color:

_x000D_
_x000D_
/* Navbar */_x000D_
.navbar-default {_x000D_
    background-color: #F8F8F8;_x000D_
    border-color: #E7E7E7;_x000D_
}_x000D_
/* Title */_x000D_
.navbar-default .navbar-brand {_x000D_
    color: #777;_x000D_
}_x000D_
.navbar-default .navbar-brand:hover,_x000D_
.navbar-default .navbar-brand:focus {_x000D_
    color: #5E5E5E;_x000D_
}_x000D_
/* Link */_x000D_
.navbar-default .navbar-nav > li > a {_x000D_
    color: #777;_x000D_
}_x000D_
.navbar-default .navbar-nav > li > a:hover,_x000D_
.navbar-default .navbar-nav > li > a:focus {_x000D_
    color: #333;_x000D_
}_x000D_
.navbar-default .navbar-nav > .active > a, _x000D_
.navbar-default .navbar-nav > .active > a:hover, _x000D_
.navbar-default .navbar-nav > .active > a:focus {_x000D_
    color: #555;_x000D_
    background-color: #E7E7E7;_x000D_
}_x000D_
.navbar-default .navbar-nav > .open > a, _x000D_
.navbar-default .navbar-nav > .open > a:hover, _x000D_
.navbar-default .navbar-nav > .open > a:focus {_x000D_
    color: #555;_x000D_
    background-color: #D5D5D5;_x000D_
}_x000D_
/* Caret */_x000D_
.navbar-default .navbar-nav > .dropdown > a .caret {_x000D_
    border-top-color: #777;_x000D_
    border-bottom-color: #777;_x000D_
}_x000D_
.navbar-default .navbar-nav > .dropdown > a:hover .caret,_x000D_
.navbar-default .navbar-nav > .dropdown > a:focus .caret {_x000D_
    border-top-color: #333;_x000D_
    border-bottom-color: #333;_x000D_
}_x000D_
.navbar-default .navbar-nav > .open > a .caret, _x000D_
.navbar-default .navbar-nav > .open > a:hover .caret, _x000D_
.navbar-default .navbar-nav > .open > a:focus .caret {_x000D_
    border-top-color: #555;_x000D_
    border-bottom-color: #555;_x000D_
}
_x000D_
_x000D_
_x000D_

Is Unit Testing worth the effort?

Occasionally either myself or one of my co-workers will spend a couple of hours getting to the bottom of slightly obscure bug and once the cause of the bug is found 90% of the time that code isn't unit tested. The unit test doesn't exist because the dev is cutting corners to save time, but then looses this and more debugging.

Taking the small amount of time to write a unit test can save hours of future debugging.

Objective-C: Reading a file line by line

Mac OS X is Unix, Objective-C is C superset, so you can just use old-school fopen and fgets from <stdio.h>. It's guaranteed to work.

[NSString stringWithUTF8String:buf] will convert C string to NSString. There are also methods for creating strings in other encodings and creating without copying.

Wordpress - Images not showing up in the Media Library

Well, Seems like there was a bug when creating custom post types in the function.php file of the theme... which bugged that.

Curl command line for consuming webServices?

Wrong. That doesn't work for me.

For me this one works:

curl 
-H 'SOAPACTION: "urn:samsung.com:service:MainTVAgent2:1#CheckPIN"'   
-X POST 
-H 'Content-type: text/xml'   
-d @/tmp/pinrequest.xml 
192.168.1.5:52235/MainTVServer2/control/MainTVAgent2

How to open the terminal in Atom?

Atom currently does not have a built-in terminal(that I know of), so you would have to install an additional package such as platformio-ide-terminal.

The following screenshots were taken on a mac.

  1. Click on Atom and select Preferences

    enter image description here

  2. In the Settings tab that appears, click on the add icon + to Install a new package

    enter image description here

  3. A search bar will appear. Most packages should have the feature you desire in their name, so you can begin to type those keywords to see suggestions. In this case if you already know the name, just enter it there

    enter image description here

  4. Click Install

Ball to Ball Collision - Detection and Handling

You have two easy ways to do this. Jay has covered the accurate way of checking from the center of the ball.

The easier way is to use a rectangle bounding box, set the size of your box to be 80% the size of the ball, and you'll simulate collision pretty well.

Add a method to your ball class:

public Rectangle getBoundingRect()
{
   int ballHeight = (int)Ball.Height * 0.80f;
   int ballWidth = (int)Ball.Width * 0.80f;
   int x = Ball.X - ballWidth / 2;
   int y = Ball.Y - ballHeight / 2;

   return new Rectangle(x,y,ballHeight,ballWidth);
}

Then, in your loop:

// Checks every ball against every other ball. 
// For best results, split it into quadrants like Ryan suggested. 
// I didn't do that for simplicity here.
for (int i = 0; i < balls.count; i++)
{
    Rectangle r1 = balls[i].getBoundingRect();

    for (int k = 0; k < balls.count; k++)
    {

        if (balls[i] != balls[k])
        {
            Rectangle r2 = balls[k].getBoundingRect();

            if (r1.Intersects(r2))
            {
                 // balls[i] collided with balls[k]
            }
        }
    }
}

How to force R to use a specified factor level as reference in a regression?

Others have mentioned the relevel command which is the best solution if you want to change the base level for all analyses on your data (or are willing to live with changing the data).

If you don't want to change the data (this is a one time change, but in the future you want the default behavior again), then you can use a combination of the C (note uppercase) function to set contrasts and the contr.treatments function with the base argument for choosing which level you want to be the baseline.

For example:

lm( Sepal.Width ~ C(Species,contr.treatment(3, base=2)), data=iris )

How to update column value in laravel

You may try this:

Page::where('id', $id)->update(array('image' => 'asdasd'));

There are other ways too but no need to use Page::find($id); in this case. But if you use find() then you may try it like this:

$page = Page::find($id);

// Make sure you've got the Page model
if($page) {
    $page->image = 'imagepath';
    $page->save();
}

Also you may use:

$page = Page::findOrFail($id);

So, it'll throw an exception if the model with that id was not found.

How to run a Command Prompt command with Visual Basic code?

You need to use CreateProcess [ http://msdn.microsoft.com/en-us/library/windows/desktop/ms682425(v=vs.85).aspx ]

For ex:

LPTSTR szCmdline[] = _tcsdup(TEXT("\"C:\Program Files\MyApp\" -L -S")); CreateProcess(NULL, szCmdline, /.../);

"Correct" way to specifiy optional arguments in R functions

You could also use missing() to test whether or not the argument y was supplied:

fooBar <- function(x,y){
    if(missing(y)) {
        x
    } else {
        x + y
    }
}

fooBar(3,1.5)
# [1] 4.5
fooBar(3)
# [1] 3

How to read until end of file (EOF) using BufferedReader in Java?

You are consuming a line at, which is discarded

while((str=input.readLine())!=null && str.length()!=0)

and reading a bigint at

BigInteger n = new BigInteger(input.readLine());

so try getting the bigint from string which is read as

BigInteger n = new BigInteger(str);

   Constructor used: BigInteger(String val)

Aslo change while((str=input.readLine())!=null && str.length()!=0) to

while((str=input.readLine())!=null)

see related post string to bigint

readLine()
Returns:
    A String containing the contents of the line, not including any line-termination characters, or null if the end of the stream has been reached 

see javadocs

SyntaxError: multiple statements found while compiling a single statement

A (partial) practical work-around is to put things into a throw-away function.

Pasting

x = 1
x += 1
print(x)

results in

>>> x = 1
x += 1
print(x)
  File "<stdin>", line 1
    x += 1
print(x)

    ^
SyntaxError: multiple statements found while compiling a single statement
>>>

However, pasting

def abc():
  x = 1
  x += 1
  print(x)

works:

>>> def abc():
  x = 1
  x += 1
  print(x)
>>> abc()
2
>>>

Of course, this is OK for a quick one-off, won't work for everything you might want to do, etc. But then, going to ipython / jupyter qtconsole is probably the next simplest option.

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

I know this is a very old question and the problem is marked as fixed. However, if someone with a case like mine where the table have trigger for data logging on update events, this will cause problem. Both the columns will get the update and log will make useless entries. The way I did

IF (CONDITION) IS TRUE
BEGIN
    UPDATE table SET columnx = 25
END
ELSE
BEGIN
    UPDATE table SET columny = 25
END

Now this have another benefit that it does not have unnecessary writes on the table like the above solutions.

Split string into array

You can try this:

var entryArray = Array.prototype.slice.call(entry)

How to revert to origin's master branch's version of file

Assuming you did not commit the file, or add it to the index, then:

git checkout -- filename

Assuming you added it to the index, but did not commit it, then:

git reset HEAD filename
git checkout -- filename

Assuming you did commit it, then:

git checkout origin/master filename

Assuming you want to blow away all commits from your branch (VERY DESTRUCTIVE):

git reset --hard origin/master

Check if a number is odd or even in python

if num % 2 == 0:
    pass # Even 
else:
    pass # Odd

The % sign is like division only it checks for the remainder, so if the number divided by 2 has a remainder of 0 it's even otherwise odd.

Or reverse them for a little speed improvement, since any number above 0 is also considered "True" you can skip needing to do any equality check:

if num % 2:
    pass # Odd
else:
    pass # Even 

jQuery .each() index?

surprise to see that no have given this syntax.

.each syntax with data or collection

jQuery.each(collection, callback(indexInArray, valueOfElement));

OR

jQuery.each( jQuery('#list option'), function(indexInArray, valueOfElement){
//your code here
}); 

declaring a priority_queue in c++ with a custom comparator

The accepted answer makes you believe that you must use a class or a std::function as comparator. This is not true! As cute_ptr's answer shows, you can pass a function pointer to the constructor. However, the syntax to do so is much simpler than shown there:

class Node;
bool Compare(Node a, Node b);

std::priority_queue<Node, std::vector<Node>, decltype(&Compare)> openSet(Compare);

That is, there is no need to explicitly encode the function's type, you can let the compiler do that for you using decltype.

This is very useful if the comparator is a lambda. You cannot specify the type of a lambda in any other way than using decltype. For example:

auto compare = [](Node a, Node b) { return a.foo < b.foo; }
std::priority_queue<Node, std::vector<Node>, decltype(compare)> openSet(compare);

How to install a specific version of package using Composer?

Add double quotes to use caret operator in version number.

composer require middlewares/whoops "^0.4"

How to dynamically create a class?

You can use System.Runtime.Remoting.Proxies.RealProxy. It will allow you to use "normal" code rather than low level assembly type stuff.

See the RealProxy answer to this question for a good example:

How do I intercept a method call in C#?

How to print a int64_t type in C

//VC6.0 (386 & better)

    __int64 my_qw_var = 0x1234567890abcdef;

    __int32 v_dw_h;
    __int32 v_dw_l;

    __asm
        {
            mov eax,[dword ptr my_qw_var + 4]   //dwh
            mov [dword ptr v_dw_h],eax

            mov eax,[dword ptr my_qw_var]   //dwl
            mov [dword ptr v_dw_l],eax

        }
        //Oops 0.8 format
    printf("val = 0x%0.8x%0.8x\n", (__int32)v_dw_h, (__int32)v_dw_l);

Regards.

find without recursion

If you look for POSIX compliant solution:

cd DirsRoot && find . -type f -print -o -name . -o -prune

-maxdepth is not POSIX compliant option.

The target ... overrides the `OTHER_LDFLAGS` build setting defined in `Pods/Pods.xcconfig

This definitely works most of the time:

Go to your target Build Settings -> Other linker flags -> double click . Add $(inherited) to a new line.

If you have problem with "...target overrides the GCC_PREPROCESSOR_DEFINITIONS build setting defined in..." then you must add $(inherited) to your target Build Settings -> Preprocessor Macros

Installing the Android USB Driver in Windows 7

Just download and install "Samsung Kies" from this link. and everything would work as required.

Before installing, uninstall the drivers you have installed for your device.

Update:

Two possible solutions:

  1. Try with the Google USB driver which comes with the SDK.
  2. Download and install the Samsung USB driver from this link as suggested by Mauricio Gracia Gutierrez

Multiple controllers with AngularJS in single page app

We can simply declare more than one Controller in the same module. Here's an example:

  <!DOCTYPE html>
    <html>

    <head>
       <script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.6.4/angular.min.js">
       </script>
      <title> New Page </title>


    </head> 
    <body ng-app="mainApp"> <!-- if we remove ng-app the add book button [show/hide] will has no effect --> 
      <h2> Books </h2>

    <!-- <input type="checkbox" ng-model="hideShow" ng-init="hideShow = false"></input> -->
    <input type = "button" value = "Add Book"ng-click="hideShow=(hideShow ? false : true)"> </input>
     <div ng-app = "mainApp" ng-controller = "bookController" ng-if="hideShow">
             Enter book name: <input type = "text" ng-model = "book.name"><br>
             Enter book category: <input type = "text" ng-model = "book.category"><br>
             Enter book price: <input type = "text" ng-model = "book.price"><br>
             Enter book author: <input type = "text" ng-model = "book.author"><br>


             You are entering book: {{book.bookDetails()}}
     </div>

    <script>
             var mainApp = angular.module("mainApp", []);

             mainApp.controller('bookController', function($scope) {
                $scope.book = {
                   name: "",
                   category: "",
                   price:"",
                   author: "",


                   bookDetails: function() {
                      var bookObject;
                      bookObject = $scope.book;
                      return "Book name: " + bookObject.name +  '\n' + "Book category: " + bookObject.category + "  \n" + "Book price: " + bookObject.price + "  \n" + "Book Author: " + bookObject.author;
                   }

                };
             });
    </script>

    <h2> Albums </h2>
    <input type = "button" value = "Add Album"ng-click="hideShow2=(hideShow2 ? false : true)"> </input>
     <div ng-app = "mainApp" ng-controller = "albumController" ng-if="hideShow2">
             Enter Album name: <input type = "text" ng-model = "album.name"><br>
             Enter Album category: <input type = "text" ng-model = "album.category"><br>
             Enter Album price: <input type = "text" ng-model = "album.price"><br>
             Enter Album singer: <input type = "text" ng-model = "album.singer"><br>


             You are entering Album: {{album.albumDetails()}}
     </div>

    <script>
             //no need to declare this again ;)
             //var mainApp = angular.module("mainApp", []);

             mainApp.controller('albumController', function($scope) {
                $scope.album = {
                   name: "",
                   category: "",
                   price:"",
                   singer: "",

                   albumDetails: function() {
                      var albumObject;
                      albumObject = $scope.album;
                      return "Album name: " + albumObject.name +  '\n' + "album category: " + albumObject.category + "\n" + "Book price: " + albumObject.price + "\n" + "Album Singer: " + albumObject.singer;
                   }
                };
             });
    </script>

    </body>
    </html>

Uncaught Error: Invariant Violation: Element type is invalid: expected a string (for built-in components) or a class/function but got: object

I had an issue with React.Fragment, because the version of my react was < 16.2, so I got rid of it.

Table with 100% width with equal size columns

<table width="400px">
  <tr>
  <td width="100px"></td>
  <td width="100px"></td>
  <td width="100px"></td>
  <td width="100px"></td>
  </tr>
</table>

For variable number of columns use %

<table width="100%">
  <tr>
  <td width="(100/x)%"></td>
  </tr>
</table>

where 'x' is number of columns

Reload browser window after POST without prompting user to resend POST data

This worked for me.

window.location = window.location.pathname;

Tested on

  • Chrome 44.0.2403
  • IE edge
  • Firefox 39.0

How can I post data as form data instead of a request payload?

The following line needs to be added to the $http object that is passed:

headers: {'Content-Type': 'application/x-www-form-urlencoded; charset=UTF-8'}

And the data passed should be converted to a URL-encoded string:

> $.param({fkey: "key"})
'fkey=key'

So you have something like:

$http({
    method: 'POST',
    url: url,
    data: $.param({fkey: "key"}),
    headers: {'Content-Type': 'application/x-www-form-urlencoded; charset=UTF-8'}
})

From: https://groups.google.com/forum/#!msg/angular/5nAedJ1LyO0/4Vj_72EZcDsJ

UPDATE

To use new services added with AngularJS V1.4, see

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

First Step

install mongodb in your linux machine with

apt install mongodb-client && apt install mongodb-server

second step is

change the database path instead of your system default path if you want.
so do the following steps and change it for yourself.

mongod --directoryperdb --dbpath /var/lib/mongodb/data/db --logpath /var/lib/mongodb/log/mongodb.log --logappend --rest

and in your windows machine do it just like that just put an --install flag. you have to get a successful message.

Best Regards...

Format date as dd/MM/yyyy using pipes

Angular: 8.2.11

<td>{{ data.DateofBirth | date }}</td>

Output: Jun 9, 1973

<td>{{ data.DateofBirth | date: 'dd/MM/yyyy' }}</td>

Output: 09/06/1973

<td>{{ data.DateofBirth | date: 'dd/MM/yyyy hh:mm a' }}</td>

Output: 09/06/1973 12:00 AM

How do I download NLTK data?

This worked for me:

nltk.set_proxy('http://user:[email protected]:8080')
nltk.download()

How to rename a file using svn?

The behaviour differs depending on whether the target file name already exists or not. It's usually a safety mechanism, and there are at least 3 different cases:

Target file does not exist:

In this case svn mv should work as follows:

$ svn mv old_file_name new_file_name
A         new_file_name
D         old_file_name
$ svn stat
A  +    new_file_name
        > moved from old_file_name
D       old_file_name
        > moved to new_file_name
$ svn commit
Adding     new_file_name
Deleting   old_file_name
Committing transaction...

Target file already exists in repository:

In this case, the target file needs to be removed explicitly, before the source file can be renamed. This can be done in the same transaction as follows:

$ svn mv old_file_name new_file_name 
svn: E155010: Path 'new_file_name' is not a directory
$ svn rm new_file_name 
D         new_file_name
$ svn mv old_file_name new_file_name 
A         new_file_name
D         old_file_name
$ svn stat
R  +    new_file_name
        > moved from old_file_name
D       old_file_name
        > moved to new_file_name
$ svn commit
Replacing      new_file_name
Deleting       old_file_name
Committing transaction...

In the output of svn stat, the R indicates that the file has been replaced, and that the file has a history.

Target file already exists locally (unversioned):

In this case, the content of the local file would be lost. If that's okay, then the file can be removed locally before renaming the existing file.

$ svn mv old_file_name new_file_name 
svn: E155010: Path 'new_file_name' is not a directory
$ rm new_file_name 
$ svn mv old_file_name new_file_name 
A         new_file_name
D         old_file_name
$ svn stat
A  +    new_file_name
        > moved from old_file_name
D       old_file_name
        > moved to new_file_name
$ svn commit
Adding         new_file_name
Deleting       old_file_name
Committing transaction...

laravel Unable to prepare route ... for serialization. Uses Closure

If someone is still looking for an answer, for me the problem was in routes/web.php file. Example:

Route::get('/', function () {
    return view('welcome');
});

It is also Route, so yeah...Just remove it if not needed and you are good to go! You should also follow answers provided from above.

Unmount the directory which is mounted by sshfs in Mac

If you have a problems with fusermount command you can kill the process :

ps -ax | grep "sshfs"

ActiveModel::ForbiddenAttributesError when creating new user

I guess you are using Rails 4. If so, the needed parameters must be marked as required.

You might want to do it like this:

class UsersController < ApplicationController

  def create
    @user = User.new(user_params)
    # ...
  end

  private

  def user_params
    params.require(:user).permit(:username, :email, :password, :salt, :encrypted_password)
  end
end

Reading *.wav files in Python

IMHO, the easiest way to get audio data from a sound file into a NumPy array is SoundFile:

import soundfile as sf
data, fs = sf.read('/usr/share/sounds/ekiga/voicemail.wav')

This also supports 24-bit files out of the box.

There are many sound file libraries available, I've written an overview where you can see a few pros and cons. It also features a page explaining how to read a 24-bit wav file with the wave module.

Google Chrome Full Black Screen

You can turn off GPU usage by Chrome without Windows restart in safe mode. Options:

1) by inserting section in Chrome config file "%USERPROFILE%\AppData\Local\Google\Chrome\User Data\Local State":

"hardware_acceleration_mode": { "enabled": false },

2) chrome.exe --disable-gpu

How to push local changes to a remote git repository on bitbucket

This is a safety measure to avoid pushing branches that are not ready to be published. Loosely speaking, by executing "git push", only local branches that already exist on the server with the same name will be pushed, or branches that have been pushed using the localbranch:remotebranch syntax.

To push all local branches to the remote repository, use --all:

git push REMOTENAME --all
git push --all

or specify all branches you want to push:

git push REMOTENAME master exp-branch-a anotherbranch bugfix

In addition, it's useful to add -u to the "git push" command, as this will tell you if your local branch is ahead or behind the remote branch. This is shown when you run "git status" after a git fetch.

Proper Linq where clauses

The second one would be more efficient as it just has one predicate to evaluate against each item in the collection where as in the first one, it's applying the first predicate to all items first and the result (which is narrowed down at this point) is used for the second predicate and so on. The results get narrowed down every pass but still it involves multiple passes.

Also the chaining (first method) will work only if you are ANDing your predicates. Something like this x.Age == 10 || x.Fat == true will not work with your first method.

What does AND 0xFF do?

it clears the all the bits that are not in the first byte

Android EditText for password with android:hint

Here is your answer. We can use both simultaniously. As i used both and they are working fine. The code is as follows:

<EditText
    android:id="@+id/edittext_password_la"
    android:layout_below="@+id/edittext_username_la"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:layout_margin="15dip"
    android:inputType="textPassword"
    android:hint="@string/string_password" />

This will help you.

HttpServletRequest - Get query string parameters, no form data

You can use request.getQueryString(),if the query string is like

username=james&password=pwd

To get name you can do this

request.getParameter("username"); 

How do I use installed packages in PyCharm?

In my PyCharm 2019.3, select the project, then File ---> Settings, then Project: YourProjectName, in 'Project Interpreter', click the interpreter or settings, ---> Show all... ---> Select the current interpreter ---> Show paths for the selected interpreter ---> then click 'Add' to add your library, in my case, it is a wheel package

Assert that a method was called in a Python unit test

I use Mock (which is now unittest.mock on py3.3+) for this:

from mock import patch
from PyQt4 import Qt


@patch.object(Qt.QMessageBox, 'aboutQt')
def testShowAboutQt(self, mock):
    self.win.actionAboutQt.trigger()
    self.assertTrue(mock.called)

For your case, it could look like this:

import mock
from mock import patch


def testClearWasCalled(self):
   aw = aps.Request("nv1")
   with patch.object(aw, 'Clear') as mock:
       aw2 = aps.Request("nv2", aw)

   mock.assert_called_with(42) # or mock.assert_called_once_with(42)

Mock supports quite a few useful features, including ways to patch an object or module, as well as checking that the right thing was called, etc etc.

Caveat emptor! (Buyer beware!)

If you mistype assert_called_with (to assert_called_once or assert_called_wiht) your test may still run, as Mock will think this is a mocked function and happily go along, unless you use autospec=true. For more info read assert_called_once: Threat or Menace.

Maximum number of threads in a .NET app?

There is no inherent limit. The maximum number of threads is determined by the amount of physical resources available. See this article by Raymond Chen for specifics.

If you need to ask what the maximum number of threads is, you are probably doing something wrong.

[Update: Just out of interest: .NET Thread Pool default numbers of threads:

  • 1023 in Framework 4.0 (32-bit environment)
  • 32767 in Framework 4.0 (64-bit environment)
  • 250 per core in Framework 3.5
  • 25 per core in Framework 2.0

(These numbers may vary depending upon the hardware and OS)]

How to create an array of object literals in a loop?

In the same idea of Nick Riggs but I create a constructor, and a push a new object in the array by using it. It avoid the repetition of the keys of the class:

var arr = [];
var columnDefs = function(key, sortable, resizeable){
    this.key = key; 
    this.sortable = sortable; 
    this.resizeable = resizeable;
    };

for (var i = 0; i < len; i++) {
    arr.push((new columnDefs(oFullResponse.results[i].label,true,true)));
}

How do you read CSS rule values with JavaScript?

Here is code to iterate through all rules in a page:

_x000D_
_x000D_
function iterateCSS(f) {_x000D_
  for (const styleSheet of window.document.styleSheets) {_x000D_
    const classes = styleSheet.rules || styleSheet.cssRules;_x000D_
    if (!classes) continue;_x000D_
_x000D_
    for (const cssRule of classes) {_x000D_
      if (cssRule.type !== 1 || !cssRule.style) continue;_x000D_
      const selector = cssRule.selectorText, style=cssRule.style;_x000D_
      if (!selector || !style.cssText) continue;_x000D_
      for (let i=0; i<style.length; i++) {_x000D_
        const propertyName=style.item(i);_x000D_
        if (f(selector, propertyName, style.getPropertyValue(propertyName), style.getPropertyPriority(propertyName), cssRule)===false) return;_x000D_
      }_x000D_
    }_x000D_
  }_x000D_
}_x000D_
_x000D_
iterateCSS( (selector, propertyName, propertyValue, propertyPriority, cssRule) => {_x000D_
  console.log(selector+' { '+propertyName+': '+propertyValue+(propertyPriority==='important' ? ' !important' : '')+' }');_x000D_
});
_x000D_
_x000D_
_x000D_

How to insert multiple rows from a single query using eloquent/fluent

It is really easy to do a bulk insert in Laravel using Eloquent or the query builder.

You can use the following approach.

$data = [
    ['user_id'=>'Coder 1', 'subject_id'=> 4096],
    ['user_id'=>'Coder 2', 'subject_id'=> 2048],
    //...
];

Model::insert($data); // Eloquent approach
DB::table('table')->insert($data); // Query Builder approach

In your case you already have the data within the $query variable.

Is it possible to register a http+domain-based URL Scheme for iPhone apps, like YouTube and Maps?

I think the least intrusive way of doing this is as follows:

  1. Check if the user-agent is that of an iPhone/iPod Touch
  2. Check for an appInstalled cookie
  3. If the cookie exists and is set to true, set window.location to your-uri:// (or do the redirect server side)
  4. If the cookie doesn't exist, open a "Did you know Your Site Name has an iPhone application?" modal with a "Yep, I've already got it", "Nope, but I'd love to try it", and "Leave me alone" button.
    1. The "Yep" button sets the cookie to true and redirects to your-uri://
    2. The "Nope" button redirects to "http://itunes.com/apps/yourappname" which will open the App Store on the device
    3. The "Leave me alone" button sets the cookie to false and closes the modal

The other option I've played with but found a little clunky was to do the following in Javascript:

setTimeout(function() {
  window.location = "http://itunes.com/apps/yourappname";
}, 25);

// If "custom-uri://" is registered the app will launch immediately and your
// timer won't fire. If it's not set, you'll get an ugly "Cannot Open Page"
// dialogue prior to the App Store application launching
window.location = "custom-uri://";

Error: EACCES: permission denied

This solved my issue straight away - mac Mojave 10.14.6 - PhpStorm.

Unhandled rejection Error: EACCES: permission denied, mkdir '/Users/myname/.npm/_cacache/index-v5/fb/5a'

sudo chown -R $USER:$GROUP ~/.npm
sudo chown -R $USER:$GROUP ~/.config

Original post: https://stackoverflow.com/a/50639828

ArrayAdapter in android to create simple listview

For your question answer is android.R.id.text1 is int: The id of the TextView within the layout resource to be populated.

ArrayAdapter has so many constructors with different number of arguments I'm mention some of them

ArrayAdapter(Context context, int resource)
ArrayAdapter(Context context, int resource, int textViewResourceId)
ArrayAdapter(Context context, int resource, T[] objects)
ArrayAdapter(Context context, int resource, int textViewResourceId, T[] objects)
ArrayAdapter(Context context, int resource, List<T> objects)
ArrayAdapter(Context context, int resource, int textViewResourceId, List<T> objects)

Now you can understand each and every constructor is different and they used different list of arguments.

And simple answer is you can use ArrayAdapter with text view inside a target xml file or without. It is doesn't matter. And you not need specify text view id you can use it without. But you may need to go with some advance option with your simple list view you must go with a text view.!

Here sample example

ArrayAdapter adapter = new ArrayAdapter<String>(this,R.layout.ListView,StringArray);
ListView listView = (ListView) findViewById(R.id.listview);
listView.setAdapter(adapter);

This is also a valid code you can use with much more clear.

How to erase the file contents of text file in Python?

Assigning the file pointer to null inside your program will just get rid of that reference to the file. The file's still there. I think the remove() function in the c stdio.h is what you're looking for there. Not sure about Python.

Get all directories within directory nodejs

Recursive solution

I came here in search of a way to get all of the subdirectories, and all of their subdirectories, etc. Building on the accepted answer, I wrote this:

const fs = require('fs');
const path = require('path');

function flatten(lists) {
  return lists.reduce((a, b) => a.concat(b), []);
}

function getDirectories(srcpath) {
  return fs.readdirSync(srcpath)
    .map(file => path.join(srcpath, file))
    .filter(path => fs.statSync(path).isDirectory());
}

function getDirectoriesRecursive(srcpath) {
  return [srcpath, ...flatten(getDirectories(srcpath).map(getDirectoriesRecursive))];
}

Github: error cloning my private repository

If you use MSYS2...

Just install the certificate packages with the following commands:

32 bits

pacman -S mingw-w64-i686-ca-certificates ca-certificates

64 bits

pacman -S mingw-w64-x86_64-ca-certificates ca-certificates

How can I format date by locale in Java?

Take a look at java.text.DateFormat. Easier to use (with a bit less power) is the derived class, java.text.SimpleDateFormat

And here is a good intro to Java internationalization: http://java.sun.com/docs/books/tutorial/i18n/index.html (the "Formatting" section addressing your problem, and more).

How to get current formatted date dd/mm/yyyy in Javascript and append it to an input

I honestly suggest that you use moment.js. Just download moment.min.js and then use this snippet to get your date in whatever format you want:

<script>
$(document).ready(function() {

     // set an element
     $("#date").val( moment().format('MMM D, YYYY') );

     // set a variable
     var today = moment().format('D MMM, YYYY');

});
</script>

Use following chart for date formats:

enter image description here

Write output to a text file in PowerShell

Use the Out-File cmdlet

 Compare-Object ... | Out-File C:\filename.txt

Optionally, add -Encoding utf8 to Out-File as the default encoding is not really ideal for many uses.

How to modify STYLE attribute of element with known ID using JQuery

$("span").mouseover(function () {
$(this).css({"background-color":"green","font-size":"20px","color":"red"});
});

<div>
Sachin Tendulkar has been the most complete batsman of his time, the most prolific     runmaker of all time, and arguably the biggest cricket icon the game has ever known. His batting is based on the purest principles: perfect balance, economy of movement, precision in stroke-making.
</div>

T-SQL string replace in Update

update YourTable
    set YourColumn = replace(YourColumn, '@domain2', '@domain1')
    where charindex('@domain2', YourColumn) <> 0

How can I selectively escape percent (%) in Python strings?

Alternatively, as of Python 2.6, you can use new string formatting (described in PEP 3101):

'Print percent % in sentence and not {0}'.format(test)

which is especially handy as your strings get more complicated.

SOAP request in PHP with CURL

Tested and working!

  • with https, user & password

     <?php 
     //Data, connection, auth
     $dataFromTheForm = $_POST['fieldName']; // request data from the form
     $soapUrl = "https://connecting.website.com/soap.asmx?op=DoSomething"; // asmx URL of WSDL
     $soapUser = "username";  //  username
     $soapPassword = "password"; // password
    
     // xml post structure
    
     $xml_post_string = '<?xml version="1.0" encoding="utf-8"?>
                         <soap:Envelope xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/">
                           <soap:Body>
                             <GetItemPrice xmlns="http://connecting.website.com/WSDL_Service"> // xmlns value to be set to your WSDL URL
                               <PRICE>'.$dataFromTheForm.'</PRICE> 
                             </GetItemPrice >
                           </soap:Body>
                         </soap:Envelope>';   // data from the form, e.g. some ID number
    
        $headers = array(
                     "Content-type: text/xml;charset=\"utf-8\"",
                     "Accept: text/xml",
                     "Cache-Control: no-cache",
                     "Pragma: no-cache",
                     "SOAPAction: http://connecting.website.com/WSDL_Service/GetPrice", 
                     "Content-length: ".strlen($xml_post_string),
                 ); //SOAPAction: your op URL
    
         $url = $soapUrl;
    
         // PHP cURL  for https connection with auth
         $ch = curl_init();
         curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, 1);
         curl_setopt($ch, CURLOPT_URL, $url);
         curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
         curl_setopt($ch, CURLOPT_USERPWD, $soapUser.":".$soapPassword); // username and password - declared at the top of the doc
         curl_setopt($ch, CURLOPT_HTTPAUTH, CURLAUTH_ANY);
         curl_setopt($ch, CURLOPT_TIMEOUT, 10);
         curl_setopt($ch, CURLOPT_POST, true);
         curl_setopt($ch, CURLOPT_POSTFIELDS, $xml_post_string); // the SOAP request
         curl_setopt($ch, CURLOPT_HTTPHEADER, $headers);
    
         // converting
         $response = curl_exec($ch); 
         curl_close($ch);
    
         // converting
         $response1 = str_replace("<soap:Body>","",$response);
         $response2 = str_replace("</soap:Body>","",$response1);
    
         // convertingc to XML
         $parser = simplexml_load_string($response2);
         // user $parser to get your data out of XML response and to display it. 
     ?>
    

How to get File Created Date and Modified Date

Use :

FileInfo fInfo = new FileInfo('FilePath');
var fFirstTime = fInfo.CreationTime;
var fLastTime = fInfo.LastWriteTime;

What is the difference between JOIN and UNION?

You may see the same schematic explanations for both, but these are totally confusing.

For UNION:

Enter image description here

For JOIN:

Enter image description here

jQuery onclick toggle class name

you can use toggleClass() to toggle class it is really handy.

case:1

<div id='mydiv' class="class1"></div>

$('#mydiv').toggleClass('class1 class2');

output: <div id='mydiv' class="class2"></div>

case:2

<div id='mydiv' class="class2"></div>

$('#mydiv').toggleClass('class1 class2');

output: <div id='mydiv' class="class1"></div>

case:3

<div id='mydiv' class="class1 class2 class3"></div>

$('#mydiv').toggleClass('class1 class2');

output: <div id='mydiv' class="class3"></div>

How to get the bluetooth devices as a list?

Find list of Nearby Bluetooth Devices:

Find Screenshot for the same.

enter image description here

MainActivity.java:

public class MainActivity extends ActionBarActivity {

    private ListView listView;
    private ArrayList<String> mDeviceList = new ArrayList<String>();
    private BluetoothAdapter mBluetoothAdapter;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        listView = (ListView) findViewById(R.id.listView);

        mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
        mBluetoothAdapter.startDiscovery();

        IntentFilter filter = new IntentFilter(BluetoothDevice.ACTION_FOUND);
        registerReceiver(mReceiver, filter);

    }


    @Override
    protected void onDestroy() {
        unregisterReceiver(mReceiver);
        super.onDestroy();
    }

    private final BroadcastReceiver mReceiver = new BroadcastReceiver() {
        public void onReceive(Context context, Intent intent) {
            String action = intent.getAction();
            if (BluetoothDevice.ACTION_FOUND.equals(action)) {
                BluetoothDevice device = intent
                        .getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
                mDeviceList.add(device.getName() + "\n" + device.getAddress());
                Log.i("BT", device.getName() + "\n" + device.getAddress());
                listView.setAdapter(new ArrayAdapter<String>(context,
                        android.R.layout.simple_list_item_1, mDeviceList));
            }
        }
    };

activity_main.xml:

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="com.example.bluetoothdemo.MainActivity" >

    <ListView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/listView"/>

</RelativeLayout>

Manifest file:

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.bluetoothdemo"
    android:versionCode="1"
    android:versionName="1.0" >

    <uses-sdk
        android:minSdkVersion="8"
        android:targetSdkVersion="21" />

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

    <application
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
        <activity
            android:name=".MainActivity"
            android:label="@string/app_name" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest>

Note:

Please make sure that you ask Location permission to your user and turn GPS On.

Reason: From Android 6.0 you need Location permission for Bluetooth Discovery.

More reference:

  1. https://developer.android.com/guide/topics/connectivity/bluetooth
  2. https://getlief.zendesk.com/hc/en-us/articles/360007600233-Why-does-Android-require-Location-Permissions-for-Bluetooth-

Done

The provided URI scheme 'https' is invalid; expected 'http'. Parameter name: via

To re-cap the question in the OP:

I am connecting [to a WCF service] using WCFStorm which is able to retrieve all the meta data properly, but when I call the actual method I get:

The provided URI scheme 'https' is invalid; expected 'http'. Parameter name: via

The WCFStorm tutorials addresses this issue in Working with IIS and SSL.

Their solution worked for me:

  1. To fix the error, generate a client config that matches the wcf service configuration. The easiest way to do this is with Visual Studio.

    • Open Visual Studio and add a service reference to the service. VS will generate an app.config file that matches the service

    • Edit the app.config file so that it can be read by WCFStorm. Please see Loading Client App.config files. Ensure that the endpoint/@name and endpoint/@contract attributes match the values in wcfstorm.

  2. Load the modified app.config to WCFStorm [using the Client Config toobar button].

  3. Invoke the method. This time the method invocation will no longer fail

Item (1) last bullet in effect means to remove the namespace prefix that VS prepends to the endpoint contract attribute, by default "ServiceReference1"

<endpoint ... contract="ServiceReference1.ListsService" ... />

so in the app.config that you load into WCFStorm you want for ListsService:

<endpoint ... contract="ListsService" ... />

How to get these two divs side-by-side?

#parent_div_1, #parent_div_2, #parent_div_3 {
  width: 100px;
  height: 100px;
  border: 1px solid red;
  margin-right: 10px;
  float: left;
}
.child_div_1 {
  float: left;
  margin-right: 5px;
}

Check working example at http://jsfiddle.net/c6242/1/

Center an element in Bootstrap 4 Navbar

Updated for Bootstrap 4.1+

Bootstrap 4 the navbar now uses flexbox so the Website Name can be centered using mx-auto. The left and right side menus don't require floats.

<nav class="navbar navbar-expand-md navbar-fixed-top navbar-dark bg-dark main-nav">
    <div class="container">
        <ul class="nav navbar-nav">
            <li class="nav-item active">
                <a class="nav-link" href="#">Home</a>
            </li>
            <li class="nav-item">
                <a class="nav-link" href="#">Download</a>
            </li>
            <li class="nav-item">
                <a class="nav-link" href="#">Register</a>
            </li>
        </ul>
        <ul class="nav navbar-nav mx-auto">
            <li class="nav-item"><a class="nav-link" href="#">Website Name</a></li>
        </ul>
        <ul class="nav navbar-nav">
            <li class="nav-item">
                <a class="nav-link" href="#">Rates</a>
            </li>
            <li class="nav-item">
                <a class="nav-link" href="#">Help</a>
            </li>
            <li class="nav-item">
                <a class="nav-link" href="#">Contact</a>
            </li>
        </ul>
    </div>
</nav>

Navbar center with mx-auto Demo

If the Navbar only has a single navbar-nav, then justify-content-center can also be used to center.

EDIT

In the solution above, the Website Name is centered relative to the left and right navbar-nav so if the width of these adjacent navs are different the Website Name is no longer centered.

enter image description here

To resolve this, one of the flexbox workarounds for absolute centering can be used...

Option 1 - Use position:absolute;

Since it's ok to use absolute positioning in flexbox, one option is to use this on the item to be centered.

.abs-center-x {
    position: absolute;
    left: 50%;
    transform: translateX(-50%);
}

Navbar center with absolute position Demo

Option 2 - Use flexbox nesting

Finally, another option is to make the centered item also display:flexbox (using d-flex) and center justified. In this case each navbar component must have flex-grow:1

As of Bootstrap 4 Beta, the Navbar is now display:flex. Bootstrap 4.1.0 includes a new flex-fill class to make each nav section fill the width:

<nav class="navbar navbar-expand-sm navbar-dark bg-dark main-nav">
    <div class="container justify-content-center">
        <ul class="nav navbar-nav flex-fill w-100 flex-nowrap">
            <li class="nav-item active">
                <a class="nav-link" href="#">Home</a>
            </li>
            <li class="nav-item">
                <a class="nav-link" href="#">Download</a>
            </li>
            <li class="nav-item">
                <a class="nav-link" href="#">Register</a>
            </li>
            <li class="nav-item">
                <a class="nav-link" href="#">More</a>
            </li>
        </ul>
        <ul class="nav navbar-nav flex-fill justify-content-center">
            <li class="nav-item"><a class="nav-link" href="#">Center</a></li>
        </ul>
        <ul class="nav navbar-nav flex-fill w-100 justify-content-end">
            <li class="nav-item">
                <a class="nav-link" href="#">Help</a>
            </li>
            <li class="nav-item">
                <a class="nav-link" href="#">Contact</a>
            </li>
        </ul>
    </div>
</nav>

Navbar center with flexbox nesting Demo

Prior to Bootstrap 4.1.0 you can add the flex-fill class like this...

.flex-fill {
   flex:1
}

As of 4.1 flex-fill is included in Bootstrap.


Bootstrap 4 Navbar center demos
More centering demos
Center links on desktop, left align on mobile

Related:
How to center nav-items in Bootstrap?
Bootstrap NavBar with left, center or right aligned items
How move 'nav' element under 'navbar-brand' in my Navbar

enter image description here

Top 5 time-consuming SQL queries in Oracle

There are a number of possible ways to do this, but have a google for tkprof

There's no GUI... it's entirely command line and possibly a touch intimidating for Oracle beginners; but it's very powerful.

This link looks like a good start:

http://www.oracleutilities.com/OSUtil/tkprof.html

When should I use GET or POST method? What's the difference between them?

When the user enters information in a form and clicks Submit , there are two ways the information can be sent from the browser to the server: in the URL, or within the body of the HTTP request.

The GET method, which was used in the example earlier, appends name/value pairs to the URL. Unfortunately, the length of a URL is limited, so this method only works if there are only a few parameters. The URL could be truncated if the form uses a large number of parameters, or if the parameters contain large amounts of data. Also, parameters passed on the URL are visible in the address field of the browser not the best place for a password to be displayed.

The alternative to the GET method is the POST method. This method packages the name/value pairs inside the body of the HTTP request, which makes for a cleaner URL and imposes no size limitations on the forms output. It is also more secure.

Set Memory Limit in htaccess

In your .htaccess you can add:

PHP 5.x

<IfModule mod_php5.c>
    php_value memory_limit 64M
</IfModule>

PHP 7.x

<IfModule mod_php7.c>
    php_value memory_limit 64M
</IfModule>

If page breaks again, then you are using PHP as mod_php in apache, but error is due to something else.

If page does not break, then you are using PHP as CGI module and therefore cannot use php values - in the link I've provided might be solution but I'm not sure you will be able to apply it.

Read more on http://support.tigertech.net/php-value

Remove '\' char from string c#

         while ((line = stringReader.ReadLine()) != null)
         {
             // split the lines
             for (int c = 0; c < line.Length; c++)
             {
                 line = line.Replace("\\", "");
                 lineBreakOne = line.Substring(1, c - 2);
                 lineBreakTwo = line.Substring(c + 2, line.Length - 2);
             }
         }

What integer hash function are good that accepts an integer hash key?

There's a nice overview over some hash algorithms at Eternally Confuzzled. I'd recommend Bob Jenkins' one-at-a-time hash which quickly reaches avalanche and therefore can be used for efficient hash table lookup.

How to Query Database Name in Oracle SQL Developer?

DESCRIBE DATABASE NAME; you need to specify the name of the database and the results will include the data type of each attribute.

How to initialize std::vector from C-style array?

The quick generic answer:

std::vector<double> vec(carray,carray+carray_size); 

or question specific:

std::vector<double> w_(w,w+len); 

based on above: Don't forget that you can treat pointers as iterators

How to disable sort in DataGridView?

If you can extend the DataGridView you can override the Sort method with am empty one. This disables Sort for the DataGridView entirely.

public override void Sort(DataGridViewColumn dataGridViewColumn, ListSortDirection direction)
{
    //base.Sort(dataGridViewColumn, direction);
}

Note: You cannot even programmatically sort any column.

Java's L number (long) specification

There are specific suffixes for long (e.g. 39832L), float (e.g. 2.4f) and double (e.g. -7.832d).

If there is no suffix, and it is an integral type (e.g. 5623), it is assumed to be an int. If it is not an integral type (e.g. 3.14159), it is assumed to be a double.

In all other cases (byte, short, char), you need the cast as there is no specific suffix.

The Java spec allows both upper and lower case suffixes, but the upper case version for longs is preferred, as the upper case L is less easy to confuse with a numeral 1 than the lower case l.

See the JLS section 3.10 for the gory details (see the definition of IntegerTypeSuffix).

Better way to revert to a previous SVN revision of a file?

If you use the Eclipse IDE with the SVN plugin you can do as follows:

  1. Right-click the files that you want to revert (or the folder they were contained in, if you deleted them by mistake and you want to add them back)
  2. Select "Team > Switch"
  3. Choose the "Revision" radion button, and enter the revision number you'd like to revert to. Click OK
  4. Go to the Synchronize perspective
  5. Select all the files you want to revert
  6. Right-click on the selection and do "Override and Commit..."

This will revert the files to the revision that you want. Just keep in mind that SVN will see the changes as a new commit. That is, the change gets a new revision number, and there is no link between the old revision and the new one. You should specify in the commit comments that you are reverting those files to a specific revision.

SQLite: How do I save the result of a query as a CSV file?

From here and d5e5's comment:

You'll have to switch the output to csv-mode and switch to file output.

sqlite> .mode csv
sqlite> .output test.csv
sqlite> select * from tbl1;
sqlite> .output stdout

Invoking a jQuery function after .each() has completed

JavaScript runs synchronously, so whatever you place after each() will not run until each() is complete.

Consider the following test:

var count = 0;
var array = [];

// populate an array with 1,000,000 entries
for(var i = 0; i < 1000000; i++) {
    array.push(i);
}

// use each to iterate over the array, incrementing count each time
$.each(array, function() {
    count++
});

// the alert won't get called until the 'each' is done
//      as evidenced by the value of count
alert(count);

When the alert is called, count will equal 1000000 because the alert won't run until each() is done.

How to parse a CSV file using PHP

I love this

        $data = str_getcsv($CsvString, "\n"); //parse the rows
        foreach ($data as &$row) {
            $row = str_getcsv($row, "; or , or whatever you want"); //parse the items in rows 
            $this->debug($row);
        }

in my case I am going to get a csv through web services, so in this way I don't need to create the file. But if you need to parser with a file, it's only necessary to pass as string

SQL Query for Selecting Multiple Records

If you know the list of ids try this query:

SELECT * FROM `Buses` WHERE BusId IN (`list of busIds`)

or if you pull them from another table list of busIds could be another subquery:

SELECT * FROM `Buses` WHERE BusId IN (SELECT SomeId from OtherTable WHERE something = somethingElse)

If you need to compare to another table you need a join:

SELECT * FROM `Buses` JOIN OtheTable on Buses.BusesId = OtehrTable.BusesId

How do you copy the contents of an array to a std::vector in C++ without looping?

In addition to the methods presented above, you need to make sure you use either std::Vector.reserve(), std::Vector.resize(), or construct the vector to size, to make sure your vector has enough elements in it to hold your data. if not, you will corrupt memory. This is true of either std::copy() or memcpy().

This is the reason to use vector.push_back(), you can't write past the end of the vector.

How do I check if the Java JDK is installed on Mac?

Type in a terminal:

which javac

It should show you something like

/usr/bin/javac

How can I solve the error 'TS2532: Object is possibly 'undefined'?

For others facing a similar problem to mine, where you know a particular object property cannot be null, you can use the non-null assertion operator (!) after the item in question. This was my code:

  const naciStatus = dataToSend.naci?.statusNACI;
  if (typeof naciStatus != "undefined") {
    switch (naciStatus) {
      case "AP":
        dataToSend.naci.certificateStatus = "FALSE";
        break;
      case "AS":
      case "WR":
        dataToSend.naci.certificateStatus = "TRUE";
        break;
      default:
        dataToSend.naci.certificateStatus = "";
    }
  }

And because dataToSend.naci cannot be undefined in the switch statement, the code can be updated to include exclamation marks as follows:

  const naciStatus = dataToSend.naci?.statusNACI;
  if (typeof naciStatus != "undefined") {
    switch (naciStatus) {
      case "AP":
        dataToSend.naci!.certificateStatus = "FALSE";
        break;
      case "AS":
      case "WR":
        dataToSend.naci!.certificateStatus = "TRUE";
        break;
      default:
        dataToSend.naci!.certificateStatus = "";
    }
  }

Java function for arrays like PHP's join()?

A similar alternative

/**
 * @param delimiter 
 * @param inStr
 * @return String
 */
public static String join(String delimiter, String... inStr)
{
    StringBuilder sb = new StringBuilder();
    if (inStr.length > 0)
    {
        sb.append(inStr[0]);
        for (int i = 1; i < inStr.length; i++)
        {
            sb.append(delimiter);                   
            sb.append(inStr[i]);
        }
    }
    return sb.toString();
}

MySQL root access from all hosts

if you have many networks attached to you OS, yo must especify one of this network in the bind-addres from my.conf file. an example:

[mysqld]
bind-address = 127.100.10.234

this ip is from a ethX configuration.

Conda activate not working?

After installing conda in Linux if you are trying to create env just type bash and hit Enter later you can create env

Writing a pandas DataFrame to CSV file

Something else you can try if you are having issues encoding to 'utf-8' and want to go cell by cell you could try the following.

Python 2

(Where "df" is your DataFrame object.)

for column in df.columns:
    for idx in df[column].index:
        x = df.get_value(idx,column)
        try:
            x = unicode(x.encode('utf-8','ignore'),errors ='ignore') if type(x) == unicode else unicode(str(x),errors='ignore')
            df.set_value(idx,column,x)
        except Exception:
            print 'encoding error: {0} {1}'.format(idx,column)
            df.set_value(idx,column,'')
            continue

Then try:

df.to_csv(file_name)

You can check the encoding of the columns by:

for column in df.columns:
    print '{0} {1}'.format(str(type(df[column][0])),str(column))

Warning: errors='ignore' will just omit the character e.g.

IN: unicode('Regenexx\xae',errors='ignore')
OUT: u'Regenexx'

Python 3

for column in df.columns:
    for idx in df[column].index:
        x = df.get_value(idx,column)
        try:
            x = x if type(x) == str else str(x).encode('utf-8','ignore').decode('utf-8','ignore')
            df.set_value(idx,column,x)
        except Exception:
            print('encoding error: {0} {1}'.format(idx,column))
            df.set_value(idx,column,'')
            continue

How to set Java classpath in Linux?

Can you provide some more details like which linux you are using? Are you loged in as root? On linux you have to run export CLASSPATH = %path%;LOG4J_HOME/og4j-1.2.16.jar If you want it permanent then you can add above lines in ~/.bashrc file.

How can I initialize base class member variables in derived class constructor?

Aggregate classes, like A in your example(*), must have their members public, and have no user-defined constructors. They are intialized with initializer list, e.g. A a {0,0}; or in your case B() : A({0,0}){}. The members of base aggregate class cannot be individually initialized in the constructor of the derived class.

(*) To be precise, as it was correctly mentioned, original class A is not an aggregate due to private non-static members

Which MIME type to use for a binary file that's specific to my program?

mimetype headers are recognised by the browser for the purpose of a (fast) possible identifying a handler to use the downloaded file as target, for example, PDF would be downloaded and your Adobe Reader program would be executed with the path of the PDF file as an argument,

If your needs are to write a browser extension to handle your downloaded file, through your operation-system, or you simply want to make you project a more 'professional looking' go ahead and select a unique mimetype for you to use, it would make no difference since the operation-system would have no handle to open it with (some browsers has few bundled-plugins, for example new Google Chrome versions has a built-in PDF-reader),

if you want to make sure the file would be downloaded have a look at this answer: https://stackoverflow.com/a/34758866/257319

if you want to make your file type especially organised, it might be worth adding a few letters in the first few bytes of the file, for example, every JPG has this at it's file start:

if you can afford a jump of 4 or 8 bytes it could be very helpful for you in the rest of the way

:)

How to run a JAR file

A very simple approach to create .class, .jar file.

Executing the jar file. No need to worry too much about manifest file. Make it simple and elgant.

Java sample Hello World Program

public class HelloWorld {
    public static void main(String[] args) {
        System.out.println("Hello World");
    }
}

Compiling the class file

javac HelloWorld.java

Creating the jar file

jar cvfe HelloWorld.jar HelloWorld HelloWorld.class

or

jar cvfe HelloWorld.jar HelloWorld *.class

Running the jar file

 java -jar HelloWorld.jar

Or

java -cp HelloWorld.jar HelloWorld

SSL handshake alert: unrecognized_name error since upgrade to Java 1.7.0

I had what I believe the same issue is. I found that I needed to adjust the Apache configuration to include a ServerName or ServerAlias for the host.

This code failed:

public class a {
   public static void main(String [] a) throws Exception {
      java.net.URLConnection c = new java.net.URL("https://mydomain.com/").openConnection();
      c.setDoOutput(true);
      c.getOutputStream();
   }
}

And this code worked:

public class a {
   public static void main(String [] a) throws Exception {
      java.net.URLConnection c = new java.net.URL("https://google.com/").openConnection();
      c.setDoOutput(true);
      c.getOutputStream();
   }
}

Wireshark revealed that during the TSL/SSL Hello the warning Alert (Level: Warning, Description: Unrecognized Name), Server Hello Was being sent from the server to the client. It was only a warning, however, Java 7.1 then responded immediately back with a "Fatal, Description: Unexpected Message", which I assume means the Java SSL libraries don't like to see the warning of unrecognized name.

From the Wiki on Transport Layer Security (TLS):

112 Unrecognized name warning TLS only; client's Server Name Indicator specified a hostname not supported by the server

This led me to look at my Apache config files and I found that if I added a ServerName or ServerAlias for the name sent from the client/java side, it worked correctly without any errors.

<VirtualHost mydomain.com:443>
  ServerName mydomain.com
  ServerAlias www.mydomain.com

ORA-01461: can bind a LONG value only for insert into a LONG column-Occurs when querying

I had the same problem with Entity Framework database first on all CLOB columns.

As a workaround, I filled the text values with spaces to be at least 4000 in width in insert operations (did not come with any better solution).

How to upload image in CodeIgniter?

check $this->upload->initialize($config); this works fine for me

    $new_image_name = "imgName".time() . str_replace(str_split(' ()\\/,:*?"<>|'), '', 
    $_FILES['userfile']['name']);
    $config = array();
    $config['upload_path'] = './uploads/'; 
    $config['allowed_types'] = 'gif|jpg|png|bmp|jpeg';
    $config['file_name'] = $new_image_name;
    $config['max_size']  = '0';
    $config['upload_path'] = './uploads/';
    $config['allowed_types'] = 'gif|jpg|png|mp4|jpeg';
    $config['file_name'] = url_title("imgsclogo");
    $config['max_size']      = '0';
    $config['overwrite']     = FALSE; 
    $this->upload->initialize($config);
    $this->upload->do_upload();
    $data = $this->upload->data();
}

How to print spaces in Python?

rjust() and ljust()

test_string = "HelloWorld"

test_string.rjust(20)
'          HelloWorld'

test_string.ljust(20)
'HelloWorld          '

Choice between vector::resize() and vector::reserve()

From your description, it looks like that you want to "reserve" the allocated storage space of vector t_Names.

Take note that resize initialize the newly allocated vector where reserve just allocates but does not construct. Hence, 'reserve' is much faster than 'resize'

You can refer to the documentation regarding the difference of resize and reserve

How do I execute .js files locally in my browser?

Around 1:51 in the video, notice how she puts a <script> tag in there? The way it works is like this:

Create an html file (that's just a text file with a .html ending) somewhere on your computer. In the same folder that you put index.html, put a javascript file (that's just a textfile with a .js ending - let's call it game.js). Then, in your index.html file, put some html that includes the script tag with game.js, like Mary did in the video. index.html should look something like this:

<html>
    <head>
        <script src="game.js"></script>
    </head>
</html>

Now, double click on that file in finder, and it should open it up in your browser. To open up the console to see the output of your javascript code, hit Command-alt-j (those three buttons at the same time).

Good luck on your journey, hope it's as fun for you as it has been for me so far :)

geom_smooth() what are the methods available?

Sometimes it's asking the question that makes the answer jump out. The methods and extra arguments are listed on the ggplot2 wiki stat_smooth page.

Which is alluded to on the geom_smooth() page with:

"See stat_smooth for examples of using built in model fitting if you need some more flexible, this example shows you how to plot the fits from any model of your choosing".

It's not the first time I've seen arguments in examples for ggplot graphs that aren't specifically in the function. It does make it tough to work out the scope of each function, or maybe I am yet to stumble upon a magic explicit list that says what will and will not work within each function.

How to pick element inside iframe using document.getElementById

You need to make sure the frame is fully loaded the best way to do it is to use onload:

<iframe id="nesgt" src="" onload="custom()"></iframe>

function custom(){
    document.getElementById("nesgt").contentWindow.document;
    }

this function will run automatically when the iframe is fully loaded.

it could be done with setTimeout but we can't get the exact time of the frame load.

hope this helps someone.

JS strings "+" vs concat method

There was a time when adding strings into an array and finalising the string by using join was the fastest/best method. These days browsers have highly optimised string routines and it is recommended that + and += methods are fastest/best

How can I throw a general exception in Java?

The simplest way to do it would be something like:

throw new java.lang.Exception();

However, the following lines would be unreachable in your code. So, we have two ways:


  1. Throw a generic exception at the bottom of the method.
  2. Throw a custom exception in case you don't want to do 1.

Join two data frames, select all columns from one and some columns from the other

drop duplicate b_id

c = a.join(b, a.a_id == b.b_id).drop(b.b_id)

How to set auto increment primary key in PostgreSQL?

If you want to do this in pgadmin, it is much easier. It seems in postgressql, to add a auto increment to a column, we first need to create a auto increment sequence and add it to the required column. I did like this.

1) Firstly you need to make sure there is a primary key for your table. Also keep the data type of the primary key in bigint or smallint. (I used bigint, could not find a datatype called serial as mentioned in other answers elsewhere)

2)Then add a sequence by right clicking on sequence-> add new sequence. If there is no data in the table, leave the sequence as it is, don't make any changes. Just save it. If there is existing data, add the last or highest value in the primary key column to the Current value in Definitions tab as shown below. enter image description here

3)Finally, add the line nextval('your_sequence_name'::regclass) to the Default value in your primary key as shown below.

enter image description here Make sure the sequence name is correct here. This is all and auto increment should work.

How to delete the top 1000 rows from a table using Sql Server 2008?

SET ROWCOUNT 1000;

DELETE FROM [MyTable] WHERE .....