Programs & Examples On #Discriminated union

Discriminated union, or disjoint union, is a data structure used to hold a value that could take on several different, but fixed types. They are also known as "sum types" in type theory.

How to check if an element is visible with WebDriver

    try{
        if( driver.findElement(By.xpath("//div***")).isDisplayed()){
          System.out.println("Element is Visible");
        }
}
catch(NoSuchElementException e){
   else{
     System.out.println("Element is InVisible");
        }
}

horizontal line and right way to code it in html, css

it is depends on requirement , but many developers suggestions is to make your code as simple as possible . so, go with simple "hr" tag and CSS code for that.

TypeError: document.getElementbyId is not a function

Case sensitive: document.getElementById (notice the capital B).

How to get the mouse position without events (without moving the mouse)?

Edit 2020: This does not work any more. It seems so, that the browser vendors patched this out. Because the most browsers rely on chromium, it might be in its core.

Old answer: You can also hook mouseenter (this event is fired after page reload, when the mousecursor is inside the page). Extending Corrupted's code should do the trick:

_x000D_
_x000D_
var x = null;_x000D_
var y = null;_x000D_
    _x000D_
document.addEventListener('mousemove', onMouseUpdate, false);_x000D_
document.addEventListener('mouseenter', onMouseUpdate, false);_x000D_
    _x000D_
function onMouseUpdate(e) {_x000D_
  x = e.pageX;_x000D_
  y = e.pageY;_x000D_
  console.log(x, y);_x000D_
}_x000D_
_x000D_
function getMouseX() {_x000D_
  return x;_x000D_
}_x000D_
_x000D_
function getMouseY() {_x000D_
  return y;_x000D_
}
_x000D_
_x000D_
_x000D_

You can also set x and y to null on mouseleave-event. So you can check if the user is on your page with it's cursor.

Java Compare Two List's object values?

Logic should be something like:

  1. First step: For class MyData implements Comparable interface, override the compareTo method as per the per object requirement.

  2. Second step: When it comes to list comparison (after checking for nulls), 2.1 Check the size of both lists, if equal returns true else return false, continue to object iteration 2.2 If step 2.1 returns true, iterate over elements from both lists and invoke something like,

    listA.get(i).compareTo(listB.get(i))

This will be as per the code mentioned in step-1.

regex.test V.S. string.match to know if a string matches a regular expression

Basic Usage

First, let's see what each function does:

regexObject.test( String )

Executes the search for a match between a regular expression and a specified string. Returns true or false.

string.match( RegExp )

Used to retrieve the matches when matching a string against a regular expression. Returns an array with the matches or null if there are none.

Since null evaluates to false,

if ( string.match(regex) ) {
  // There was a match.
} else {
  // No match.
} 

Performance

Is there any difference regarding performance?

Yes. I found this short note in the MDN site:

If you need to know if a string matches a regular expression regexp, use regexp.test(string).

Is the difference significant?

The answer once more is YES! This jsPerf I put together shows the difference is ~30% - ~60% depending on the browser:

test vs match | Performance Test

Conclusion

Use .test if you want a faster boolean check. Use .match to retrieve all matches when using the g global flag.

String concatenation in Ruby

You can do that in several ways:

  1. As you shown with << but that is not the usual way
  2. With string interpolation

    source = "#{ROOT_DIR}/#{project}/App.config"
    
  3. with +

    source = "#{ROOT_DIR}/" + project + "/App.config"
    

The second method seems to be more efficient in term of memory/speed from what I've seen (not measured though). All three methods will throw an uninitialized constant error when ROOT_DIR is nil.

When dealing with pathnames, you may want to use File.join to avoid messing up with pathname separator.

In the end, it is a matter of taste.

Understanding repr( ) function in Python

>>> x = 'foo'
>>> x
'foo'

So the name x is attached to 'foo' string. When you call for example repr(x) the interpreter puts 'foo' instead of x and then calls repr('foo').

>>> repr(x)
"'foo'"
>>> x.__repr__()
"'foo'"

repr actually calls a magic method __repr__ of x, which gives the string containing the representation of the value 'foo' assigned to x. So it returns 'foo' inside the string "" resulting in "'foo'". The idea of repr is to give a string which contains a series of symbols which we can type in the interpreter and get the same value which was sent as an argument to repr.

>>> eval("'foo'")
'foo'

When we call eval("'foo'"), it's the same as we type 'foo' in the interpreter. It's as we directly type the contents of the outer string "" in the interpreter.

>>> eval('foo')

Traceback (most recent call last):
  File "<pyshell#5>", line 1, in <module>
    eval('foo')
  File "<string>", line 1, in <module>
NameError: name 'foo' is not defined

If we call eval('foo'), it's the same as we type foo in the interpreter. But there is no foo variable available and an exception is raised.

>>> str(x)
'foo'
>>> x.__str__()
'foo'
>>> 

str is just the string representation of the object (remember, x variable refers to 'foo'), so this function returns string.

>>> str(5)
'5'

String representation of integer 5 is '5'.

>>> str('foo')
'foo'

And string representation of string 'foo' is the same string 'foo'.

jQuery - Getting the text value of a table cell in the same row as a clicked element

This will also work

$(this).parent().parent().find('td').text()

How to read data from excel file using c#

I don't have a machine available to test this but it should work. First you will probably need to install the either the 2007 Office System Driver: Data Connectivity Components or the Microsoft Access Database Engine 2010 Redistributable. Then try the following code, note you will need to change the name of the Sheet in the Select statement below to match sheetname in your excel file:

using System.Data;
using System.Data.OleDb;

namespace Data_Migration_Process_Creator
{
    class Class1
    {
        private DataTable GetDataTable(string sql, string connectionString)
        {
            DataTable dt = null;

            using (OleDbConnection conn = new OleDbConnection(connectionString))
            {
                conn.Open();
                using (OleDbCommand cmd = new OleDbCommand(sql, conn))
                {
                    using (OleDbDataReader rdr = cmd.ExecuteReader())
                    {
                        dt.Load(rdr);
                        return dt;
                    }
                }
            }
        }

        private void GetExcel()
        {
            string fullPathToExcel = "<Path to Excel file>"; //ie C:\Temp\YourExcel.xls
            string connString = string.Format("Provider=Microsoft.ACE.OLEDB.12.0;Data Source={0};Extended Properties='Excel 12.0;HDR=yes'", fullPathToExcel);
            DataTable dt = GetDataTable("SELECT * from [SheetName$]", connString);

            foreach (DataRow dr in dt.Rows)
            {
                //Do what you need to do with your data here
            }
        }
    }
}

Note: I don't have an environment to test this in (One with Office installed) so I can't say if it will work in your environment or not but I don't see why it shouldn't work.

How to run a shell script at startup

Working with Python 3 microservices or shell; using Ubuntu Server 18.04 (Bionic Beaver) or Ubuntu 19.10 (Eoan Ermine) or Ubuntu 18.10 (Cosmic Cuttlefish) I always do like these steps, and it worked always too:

  1. Creating a microservice called p example "brain_microservice1.service" in my case:

    $ nano /lib/systemd/system/brain_microservice1.service
    
  2. Inside this new service that you are in:

    [Unit]
    Description=brain_microservice_1
    After=multi-user.target
    
    [Service]
    Type=simple
    ExecStart=/usr/bin/python3.7 /root/scriptsPython/RUN_SERVICES/microservices    /microservice_1.py -k start -DFOREGROUND
    ExecStop=/usr/bin/python3.7 /root/scriptsPython/RUN_SERVICES/microservices/microservice_1.py -k graceful-stop
    ExecReload=/usr/bin/python3.7 /root/scriptsPython/RUN_SERVICES/microservices/microservice_1.py -k graceful
    PrivateTmp=true
    LimitNOFILE=infinity
    KillMode=mixed
    Restart=on-failure
    RestartSec=5s
    
    [Install]
    WantedBy=multi-user.target
    
  3. Give the permissions:

    $ chmod -X /lib/systemd/system/brain_microservice*
    $ chmod -R 775 /lib/systemd/system/brain_microservice*
    
  4. Give the execution permission then:

    $ systemctl daemon-reload
    
  5. Enable then, this will make then always start on startup

    $ systemctl enable brain_microservice1.service
    
  6. Then you can test it;

    $ sudo reboot now

  7. Finish = SUCCESS!!

This can be done with the same body script to run shell, react ... database startup script ... any kind os code ... hope this help u...

...

Convert date time string to epoch in Bash

Just be sure what timezone you want to use.

datetime="06/12/2012 07:21:22"

Most popular use takes machine timezone.

date -d "$datetime" +"%s" #depends on local timezone, my output = "1339456882"

But in case you intentionally want to pass UTC datetime and you want proper timezone you need to add -u flag. Otherwise you convert it from your local timezone.

date -u -d "$datetime" +"%s" #general output = "1339485682"

Comments in Markdown

You can try

[](
Your comments go here however you cannot leave
// a blank line so fill blank lines with
//
Something
)

Replacing blank values (white space) with NaN in pandas

I think df.replace() does the job, since pandas 0.13:

df = pd.DataFrame([
    [-0.532681, 'foo', 0],
    [1.490752, 'bar', 1],
    [-1.387326, 'foo', 2],
    [0.814772, 'baz', ' '],     
    [-0.222552, '   ', 4],
    [-1.176781,  'qux', '  '],         
], columns='A B C'.split(), index=pd.date_range('2000-01-01','2000-01-06'))

# replace field that's entirely space (or empty) with NaN
print(df.replace(r'^\s*$', np.nan, regex=True))

Produces:

                   A    B   C
2000-01-01 -0.532681  foo   0
2000-01-02  1.490752  bar   1
2000-01-03 -1.387326  foo   2
2000-01-04  0.814772  baz NaN
2000-01-05 -0.222552  NaN   4
2000-01-06 -1.176781  qux NaN

As Temak pointed it out, use df.replace(r'^\s+$', np.nan, regex=True) in case your valid data contains white spaces.

Java project in Eclipse: The type java.lang.Object cannot be resolved. It is indirectly referenced from required .class files

Object class is the base class for all the classes in java, if you are missing this it means you don't have the jdk libs in your buildpath. I don't know much about Kepler but you need to make sure it points to a correct jdk for compilation and a correct jre for running your java apps.

However I have set the path as C:\Program Files\Java\jdk1.6.0_41 from eclipse Kepler toolbar->windows->preferences->java->installed jre

You are trying to point jdk instead of jre in your preferences. toolbar->windows->preferences->java->installed jre should point to a jre and not jdk.

Dynamically adding elements to ArrayList in Groovy

What you actually created with:

MyType[] list = []

Was fixed size array (not list) with size of 0. You can create fixed size array of size for example 4 with:

MyType[] array = new MyType[4]

But there's no add method of course.

If you create list with def it's something like creating this instance with Object (You can read more about def here). And [] creates empty ArrayList in this case.

So using def list = [] you can then append new items with add() method of ArrayList

list.add(new MyType())

Or more groovy way with overloaded left shift operator:

list << new MyType() 

Select SQL results grouped by weeks

I think this should do it..

Select 
ProductName,
WeekNumber,
sum(sale)
from
(
    SELECT 
    ProductName,
    DATEDIFF(week, '2011-05-30', date) AS WeekNumber,
    sale
    FROM table
)
GROUP BY
ProductName,
WeekNumber

Convert string to date in bash

We can use date -d option

1) Change format to "%Y-%m-%d" format i.e 20121212 to 2012-12-12

date -d '20121212' +'%Y-%m-%d'

2)Get next or last day from a given date=20121212. Like get a date 7 days in past with specific format

date -d '20121212 -7 days' +'%Y-%m-%d'

3) If we are getting date in some variable say dat

dat2=$(date -d "$dat -1 days" +'%Y%m%d')

PHP display image BLOB from MySQL

This is what I use to display images from blob:

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

JavaScript split String with white space

You can just split on the word boundary using \b. See MDN

"\b: Matches a zero-width word boundary, such as between a letter and a space."

You should also make sure it is followed by whitespace \s. so that strings like "My car isn't red" still work:

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

The initial \b is required to take multiple spaces into account, e.g. my car is red

EDIT: Added grouping

How can I compile a Java program in Eclipse without running it?

Try this in your console:

javac {$PathToYourProyect}/*

If you also need any external library, try:

javac -cp {$PathToYourLibrary}.jar {$PathToYourProyect}/*

Cannot install node modules that require compilation on Windows 7 x64/VS2012

For windows 8 64-bit, installing zmq and protobuf, the following worked for me: Install Visual Studio 2012 On the command line:

SET VisualStudioVersion=11.0
npm install zmq
npm install protobuf

How can I pretty-print JSON using node.js?

what about this?

console.table(object)

sample

How to remove folders with a certain name

I ended up here looking to delete my node_modules folders before doing a backup of my work in progress using rsync. A key requirements is that the node_modules folder can be nested, so you need the -prune option.

First I ran this to visually verify the folders to be deleted:

find -type d -name node_modules -prune

Then I ran this to delete them all:

find -type d -name node_modules -prune -exec rm -rf {} \;

Thanks to pistache

Compare two date formats in javascript/jquery

As in your example, the fit_start_time is not later than the fit_end_time.

Try it the other way round:

var fit_start_time  = $("#fit_start_time").val(); //2013-09-5
var fit_end_time    = $("#fit_end_time").val(); //2013-09-10

if(Date.parse(fit_start_time) <= Date.parse(fit_end_time)){
    alert("Please select a different End Date.");
}

Update

Your code implies that you want to see the alert with the current variables you have. If this is the case then the above code is correct. If you're intention (as per the implication of the alert message) is to make sure their fit_start_time variable is a date that is before the fit_end_time, then your original code is fine, but the data you're getting from the jQuery .val() methods is not parsing correctly. It would help if you gave us the actual HTML which the selector is sniffing at.

MySql Inner Join with WHERE clause

You are using two WHERE clauses but only one is allowed. Use it like this:

SELECT table1.f_id FROM table1
INNER JOIN table2 ON table2.f_id = table1.f_id
WHERE
  table1.f_com_id = '430'
  AND table1.f_status = 'Submitted'
  AND table2.f_type = 'InProcess'

Accessing dict keys like an attribute?

I created this based on the input from this thread. I need to use odict though, so I had to override get and set attr. I think this should work for the majority of special uses.

Usage looks like this:

# Create an ordered dict normally...
>>> od = OrderedAttrDict()
>>> od["a"] = 1
>>> od["b"] = 2
>>> od
OrderedAttrDict([('a', 1), ('b', 2)])

# Get and set data using attribute access...
>>> od.a
1
>>> od.b = 20
>>> od
OrderedAttrDict([('a', 1), ('b', 20)])

# Setting a NEW attribute only creates it on the instance, not the dict...
>>> od.c = 8
>>> od
OrderedAttrDict([('a', 1), ('b', 20)])
>>> od.c
8

The class:

class OrderedAttrDict(odict.OrderedDict):
    """
    Constructs an odict.OrderedDict with attribute access to data.

    Setting a NEW attribute only creates it on the instance, not the dict.
    Setting an attribute that is a key in the data will set the dict data but 
    will not create a new instance attribute
    """
    def __getattr__(self, attr):
        """
        Try to get the data. If attr is not a key, fall-back and get the attr
        """
        if self.has_key(attr):
            return super(OrderedAttrDict, self).__getitem__(attr)
        else:
            return super(OrderedAttrDict, self).__getattr__(attr)


    def __setattr__(self, attr, value):
        """
        Try to set the data. If attr is not a key, fall-back and set the attr
        """
        if self.has_key(attr):
            super(OrderedAttrDict, self).__setitem__(attr, value)
        else:
            super(OrderedAttrDict, self).__setattr__(attr, value)

This is a pretty cool pattern already mentioned in the thread, but if you just want to take a dict and convert it to an object that works with auto-complete in an IDE, etc:

class ObjectFromDict(object):
    def __init__(self, d):
        self.__dict__ = d

.htaccess redirect www to non-www with SSL/HTTPS

www to non www with https

RewriteEngine on

RewriteCond %{HTTP_HOST} ^www\.(.*)$ [NC]
RewriteRule ^(.*)$ https://%1/$1 [R=301,L]

RewriteCond %{ENV:HTTPS} !on
RewriteRule ^(.*)$ https://%{HTTP_HOST}%{REQUEST_URI} [R=301,L]

Display fullscreen mode on Tkinter

This will create a completely fullscreen window on mac (with no visible menubar) without messing up keybindings

import tkinter as tk
root = tk.Tk()

root.overrideredirect(True)
root.overrideredirect(False)
root.attributes('-fullscreen',True)


root.mainloop()

Scrolling to element using webdriver?

You can scroll to the element by using javascript through the execute_javascript method. For example here is how I do it using SeleniumLibrary on Robot Framework:

web_element = self.selib.find_element(locator)
self.selib.execute_javascript(
    "ARGUMENTS",
    web_element,
    "JAVASCRIPT",
    'arguments[0].scrollIntoView({behavior: "instant", block: "start", inline: "start"});'
)

Should I use the Reply-To header when sending emails as a service to others?

You may want to consider placing the customer's name in the From header and your address in the Sender header:

From: Company A <[email protected]>
Sender: [email protected]

Most mailers will render this as "From [email protected] on behalf of Company A", which is accurate. And then a Reply-To of Company A's address won't seem out of sorts.

From RFC 5322:

The "From:" field specifies the author(s) of the message, that is, the mailbox(es) of the person(s) or system(s) responsible for the writing of the message. The "Sender:" field specifies the mailbox of the agent responsible for the actual transmission of the message. For example, if a secretary were to send a message for another person, the mailbox of the secretary would appear in the "Sender:" field and the mailbox of the actual author would appear in the "From:" field.

SQL Server® 2016, 2017 and 2019 Express full download

When you can't apply Juki's answer then after selecting the desired version of media you can use Fiddler to determine where the files are located.

SQL Server 2019 Express Edition (English):

SQL Server 2017 Express Edition (English):

SQL Server 2016 with SP2 Express Edition (English):

SQL Server 2016 with SP1 Express Edition (English):

And here is how to use Fiddler.

Sort dataGridView columns in C# ? (Windows Form)

There's a method on the DataGridView called "Sort":

this.dataGridView1.Sort(this.dataGridView1.Columns["Name"], ListSortDirection.Ascending);

This will programmatically sort your datagridview.

How to align text below an image in CSS?

Best way is to wrap the Image and Paragraph text with a DIV and assign a class.

Example:

<div class="image1">
    <div class="imgWrapper">
        <img src="images/img1.png" width="250" height="444" alt="Screen 1"/>
        <p>It's my first Image</p>
    </div>
    ...
    ...
    ...
    ...
</div>

What is the fastest way to create a checksum for large files in C#

As Anton Gogolev noted, FileStream reads 4096 bytes at a time by default, But you can specify any other value using the FileStream constructor:

new FileStream(file, FileMode.Open, FileAccess.Read, FileShare.ReadWrite, 16 * 1024 * 1024)

Note that Brad Abrams from Microsoft wrote in 2004:

there is zero benefit from wrapping a BufferedStream around a FileStream. We copied BufferedStream’s buffering logic into FileStream about 4 years ago to encourage better default performance

source

Create a string and append text to it

Use the string concatenation operator:

Dim str As String = New String("") & "some other string"

Strings in .NET are immutable and thus there exist no concept of appending strings. All string modifications causes a new string to be created and returned.

This obviously cause a terrible performance. In common everyday code this isn't an issue, but if you're doing intensive string operations in which time is of the essence then you will benefit from looking into the StringBuilder class. It allow you to queue appends. Once you're done appending you can ask it to actually perform all the queued operations.

See "How to: Concatenate Multiple Strings" for more information on both methods.

In SQL, is UPDATE always faster than DELETE+INSERT?

The bigger the table (number of and size of columns) the more expensive it becomes to delete and insert rather than update. Because you have to pay the price of UNDO and REDO. DELETEs consume more UNDO space than UPDATEs, and your REDO contains twice as many statements as are necessary.

Besides, it is plain wrong from a business point of view. Consider how much harder it would be to understand a notional audit trail on that table.


There are some scenarios involving bulk updates of all the rows in a table where it is faster to create a new table using CTAS from the old table (applying the update in the the projection of the SELECT clause), dropping the old table and renaming the new table. The side-effects are creating indexes, managing constraints and renewing privileges, but it is worth considering.

Drop Down Menu/Text Field in one

Option 1

Include the script from dhtmlgoodies and initialize like this:

<input type="text" name="myText" value="Norway"
       selectBoxOptions="Canada;Denmark;Finland;Germany;Mexico"> 
createEditableSelect(document.forms[0].myText);

Option 2

Here's a custom solution which combines a <select> element and <input> element, styles them, and toggles back and forth via JavaScript

<div style="position:relative;width:200px;height:25px;border:0;padding:0;margin:0;">
  <select style="position:absolute;top:0px;left:0px;width:200px; height:25px;line-height:20px;margin:0;padding:0;"
          onchange="document.getElementById('displayValue').value=this.options[this.selectedIndex].text; document.getElementById('idValue').value=this.options[this.selectedIndex].value;">
    <option></option>
    <option value="one">one</option>
    <option value="two">two</option>
    <option value="three">three</option>
  </select>
  <input type="text" name="displayValue" id="displayValue" 
         placeholder="add/select a value" onfocus="this.select()"
         style="position:absolute;top:0px;left:0px;width:183px;width:180px\9;#width:180px;height:23px; height:21px\9;#height:18px;border:1px solid #556;"  >
  <input name="idValue" id="idValue" type="hidden">
</div>

Python Sets vs Lists

Sets are faster, morover you get more functions with sets, such as lets say you have two sets :

set1 = {"Harry Potter", "James Bond", "Iron Man"}
set2 = {"Captain America", "Black Widow", "Hulk", "Harry Potter", "James Bond"}

We can easily join two sets:

set3 = set1.union(set2)

Find out what is common in both:

set3 = set1.intersection(set2)

Find out what is different in both:

set3 = set1.difference(set2)

And much more! Just try them out, they are fun! Moreover if you have to work on the different values within 2 list or common values within 2 lists, I prefer to convert your lists to sets, and many programmers do in that way. Hope it helps you :-)

How to get docker-compose to always re-create containers from fresh images?

$docker-compose build

If there is something new it will be rebuilt.

How to filter files when using scp to copy dir recursively?

I'd probably recommend using something like rsync for this due to its include and exclude flags, e.g:-

rsync -rav -e ssh --include '*/' --include='*.class' --exclude='*' \
server:/usr/some/unknown/number/of/sub/folders/ \ 
/usr/project/backup/some/unknown/number/of/sub/folders/

Some other useful flags:

  • -r for recursive
  • -a for archive (mostly all files)
  • -v for verbose output
  • -e to specify ssh instead of the default (which should be ssh, actually)

WARNING: sanitizing unsafe style value url

Based on the docs at https://angular.io/api/platform-browser/DomSanitizer, the right way to do this seems to be to use sanitize. At least in Angular 7 (don't know if this changed from before). This worked for me:

import { Component, OnInit, Input, SecurityContext } from '@angular/core';
import { DomSanitizer } from '@angular/platform-browser';

constructor(
    private sanitizer: DomSanitizer
) { }

this.sanitizer.sanitize(SecurityContext.STYLE, 'url(' + this.image + ')');

Re SecurityContext, see https://angular.io/api/core/SecurityContext. Basically it's just this enum:

enum SecurityContext {
  NONE: 0
  HTML: 1
  STYLE: 2
  SCRIPT: 3
  URL: 4
  RESOURCE_URL: 5
}

The POST method is not supported for this route. Supported methods: GET, HEAD. Laravel

If you are using a Route::group, with a vendor plugin like LaravelLocalization (from MCAMARA), you need to put POST routes outside of this group. I've experienced problems with POST routes using this plugin and I did solved right now by putting these routes outside Route::group..

Get unique values from a list in python

In addition to the previous answers, which say you can convert your list to set, you can do that in this way too

mylist = [u'nowplaying', u'PBS', u'PBS', u'nowplaying', u'job', u'debate', u'thenadnow']
mylist = [i for i in set(mylist)]

output will be

[u'nowplaying', u'job', u'debate', u'PBS', u'thenadnow']

though order will not be preserved.

Another simpler answer could be (without using sets)

>>> t = [v for i,v in enumerate(mylist) if mylist.index(v) == i]
[u'nowplaying', u'PBS', u'job', u'debate', u'thenadnow']

pandas GroupBy columns with NaN (missing) values

I answered this already, but some reason the answer was converted to a comment. Nevertheless, this is the most efficient solution:

Not being able to include (and propagate) NaNs in groups is quite aggravating. Citing R is not convincing, as this behavior is not consistent with a lot of other things. Anyway, the dummy hack is also pretty bad. However, the size (includes NaNs) and the count (ignores NaNs) of a group will differ if there are NaNs.

dfgrouped = df.groupby(['b']).a.agg(['sum','size','count'])

dfgrouped['sum'][dfgrouped['size']!=dfgrouped['count']] = None

When these differ, you can set the value back to None for the result of the aggregation function for that group.

mailto using javascript

You can use the simple mailto, see below for the simple markup.

<a href="mailto:[email protected]">Click here to mail</a>

Once clicked, it will open your Outlook or whatever email client you have set.

Get img src with PHP

Use a HTML parser like DOMDocument and then evaluate the value you're looking for with DOMXpath:

$html = '<img id="12" border="0" src="/images/image.jpg"
         alt="Image" width="100" height="100" />';

$doc = new DOMDocument();
$doc->loadHTML($html);
$xpath = new DOMXPath($doc);
$src = $xpath->evaluate("string(//img/@src)"); # "/images/image.jpg"

Or for those who really need to save space:

$xpath = new DOMXPath(@DOMDocument::loadHTML($html));
$src = $xpath->evaluate("string(//img/@src)");

And for the one-liners out there:

$src = (string) reset(simplexml_import_dom(DOMDocument::loadHTML($html))->xpath("//img/@src"));

When do I use super()?

I just tried it, commenting super(); does the same thing without commenting it as @Mark Peters said

package javaapplication6;

/**
 *
 * @author sborusu
 */
public class Super_Test {
    Super_Test(){
        System.out.println("This is super class, no object is created");
    }
}
class Super_sub extends Super_Test{
    Super_sub(){
       super();
       System.out.println("This is sub class, object is created");
    }
    public static void main(String args[]){
        new Super_sub();
    }
}

How do you install Boost on MacOS?

Unless your compiler is different than the one supplied with the Mac XCode Dev tools, just follow the instructions in section 5.1 of Getting Started Guide for Unix Variants. The configuration and building of the latest source couldn't be easier, and it took all about about 1 minute to configure and 10 minutes to compile.

Cannot use object of type stdClass as array?

To get an array as result from a json string you should set second param as boolean true.

$result = json_decode($json_string, true);
$context = $result['context'];

Otherwise $result will be an std object. but you can access values as object.

  $result = json_decode($json_string);
 $context = $result->context;

How can I provide multiple conditions for data trigger in WPF?

@jasonk - if you want to have "or" then negate all conditions since (A and B) <=> ~(~A or ~B)

but if you have values other than boolean try using type converters:

<MultiDataTrigger.Conditions>
    <Condition Value="True">
        <Condition.Binding>
            <MultiBinding Converter="{StaticResource conditionConverter}">
                <Binding Path="Name" />
                <Binding Path="State" />
            </MultiBinding>
        </Condition.Binding>
        <Setter Property="Background" Value="Cyan" />
    </Condition>
</MultiDataTrigger.Conditions>

you can use the values in Convert method any way you like to produce a condition which suits you.

How to use 'cp' command to exclude a specific directory?

cp -rv `ls -A | grep -vE "dirToExclude|targetDir"` targetDir

Edit: forgot to exclude the target path as well (otherwise it would recursively copy).

Ignoring new fields on JSON objects using Jackson

You can annotate the specific property in your POJO with @JsonIgnore.

Difference between document.addEventListener and window.addEventListener?

The window binding refers to a built-in object provided by the browser. It represents the browser window that contains the document. Calling its addEventListener method registers the second argument (callback function) to be called whenever the event described by its first argument occurs.

<p>Some paragraph.</p>
<script>
  window.addEventListener("click", () => {
    console.log("Test");
  });
</script>

Following points should be noted before select window or document to addEventListners

  1. Most of the events are same for window or document but some events like resize, and other events related to loading, unloading, and opening/closing should all be set on the window.
  2. Since window has the document it is good practice to use document to handle (if it can handle) since event will hit document first.
  3. Internet Explorer doesn't respond to many events registered on the window,so you will need to use document for registering event.

Merge (with squash) all changes from another branch as a single commit

Try git rebase -i master on your feature branch. You can then change all but one 'pick' to 'squash' to combine the commits. See squashing commits with rebase

Finally, you can then do the merge from master branch.

How to copy files between two nodes using ansible

You can use deletgate with scp too:

- name: Copy file to another server
  become: true
  shell: "scp -o StrictHostKeyChecking=no -o UserKnownHostsFile=/dev/null admin@{{ inventory_hostname }}:/tmp/file.yml /tmp/file.yml"
  delegate_to: other.example.com

Because of delegate the command is run on the other server and it scp's the file to itself.

Efficient SQL test query or validation query that will work across all (or most) databases

For tests using select count(*), it should be more efficient to use select count(1) because * can cause it to read all the column data.

Entitlements file do not match those specified in your provisioning profile.(0xE8008016)

File > Workspace Settings > Build System > Legacy Build System

This worked for me. Xcode 10.0

Apply function to pandas groupby

Regarding the issue with 'size', size is not a function on a dataframe, it is rather a property. So instead of using size(), plain size should work

Apart from that, a method like this should work

 def doCalculation(df):
    groupCount = df.size
    groupSum = df['my_labels'].notnull().sum()

    return groupCount / groupSum

dataFrame.groupby('my_labels').apply(doCalculation)

How to fix error ::Format of the initialization string does not conform to specification starting at index 0::

I was getting this exception, fixed it by adding throwIfV1Schema: false to my DbContext constructor:

public class AppDb : IdentityDbContext<User>
{
    public AppDb()
        : base("DefaultConnection", throwIfV1Schema: false)
    {
    }
}

Can I edit an iPad's host file?

Best Answer: Simply add http or https in your browser, the IP address, colon and port number. Example: https://123.23.145.67:80

How to hide the Google Invisible reCAPTCHA badge

Recaptcha contact form 7 and Recaptcha v3 solution.

body:not(.page-id-20) .grecaptcha-badge {
    display: none;
}

More Than One Contact Form Page?

body:not(.page-id-12):not(.page-id-43) .grecaptcha-badge {
    display: none;
}

You can add more “nots” if you have more contact form pages.

body:not(.page-id-45):not(.page-id-78):not(.page-id-98) .grecaptcha-badge {
    display: none;
}

Make sure that your body section will like this:

<body>

Change it so that it looks like this:

 <body <?php body_class(); ?>>

Undefined index with $_POST

Try this:

I use this everywhere where there is a $_POST request.

$username=isset($_POST['username']) ? $_POST['username'] : "";

This is just a short hand boolean, if isset it will set it to $_POST['username'], if not then it will set it to an empty string.

Usage example:

if($username===""){ echo "Field is blank" } else { echo "Success" };

How to Force New Google Spreadsheets to refresh and recalculate?

What worked for me is inserting a column before the first column and deleting it immediately. Basically, do a change that will affect all the cells in the worksheet that will trigger recalculation.

Convert factor to integer

Quoting directly from the help page for factor:

To transform a factor f to its original numeric values, as.numeric(levels(f))[f] is recommended and slightly more efficient than as.numeric(as.character(f)).

How to make a node.js application run permanently?

Another way is creating a system unit for your app. create a "XXX.service" file in "/etc/systemd/system" folder, similar to this:

[Unit]
Description=swagger
After=network.target

[Service]
ExecStart=/usr/bin/http-server /home/swagger/swagger-editor &
WorkingDirectory=/home/swagger
Restart=always
RestartSec=30

[Install]
WantedBy=multi-user.target

A benefit is the app will run as a service, it automatically restarts if it crashed.

You can also use sytemctl to manage it:

systemctl start XXX to start the service, systemctl stop XXX to stop it and systemctl enable XXX to automatically start the app when system boots.

Chart.js v2 hide dataset labels

Replace options with this snippet, will fix for Vanilla JavaScript Developers

_x000D_
_x000D_
options: {
            title: {
                text: 'Hello',
                display: true
            },
            scales: {
                xAxes: [{
                    ticks: {
                        display: false
                    }
                }]
            },
            legend: {
                display: false
            }
        }
_x000D_
_x000D_
_x000D_

Maven project.build.directory

Aside from @Verhás István answer (which I like), I was expecting a one-liner for the question:

${project.reporting.outputDirectory} resolves to target/site in your project.

Reading from memory stream to string

If you'd checked the results of stream.Read, you'd have seen that it hadn't read anything - because you haven't rewound the stream. (You could do this with stream.Position = 0;.) However, it's easier to just call ToArray:

settingsString = LocalEncoding.GetString(stream.ToArray());

(You'll need to change the type of stream from Stream to MemoryStream, but that's okay as it's in the same method where you create it.)

Alternatively - and even more simply - just use StringWriter instead of StreamWriter. You'll need to create a subclass if you want to use UTF-8 instead of UTF-16, but that's pretty easy. See this answer for an example.

I'm concerned by the way you're just catching Exception and assuming that it means something harmless, by the way - without even logging anything. Note that using statements are generally cleaner than writing explicit finally blocks.

How to use git merge --squash?

Assume the name of the branch where you made multiple commits is called bugfix/123, and you want to squash these commits.
First, create a new branch from develop (or whatever the name of your repo is). Assume the name of the new branch is called bugfix/123_up. Checkout this branch in git bash -

  • git fetch
  • git checkout bugfix/123_up
  • git merge bugfix/123 --squash
  • git commit -m "your message"
  • git push origin bugfix/123_up

Now this branch will have only one commit with all your changes in it.

An internal error occurred during: "Updating Maven Project". Unsupported IClasspathEntry kind=4

I solved this by looking at this comment on JBIDE-11655 : deleting all .project, .settings and .classpath in my projects folder.

How often should Oracle database statistics be run?

Whenever the data changes "significantly".

If a table goes from 1 row to 200 rows, that's a significant change. When a table goes from 100,000 rows to 150,000 rows, that's not a terribly significant change. When a table goes from 1000 rows all with identical values in commonly-queried column X to 1000 rows with nearly unique values in column X, that's a significant change.

Statistics store information about item counts and relative frequencies -- things that will let it "guess" at how many rows will match a given criteria. When it guesses wrong, the optimizer can pick a very suboptimal query plan.

jquery - Click event not working for dynamically created button

the simple and easy way to do that is use on event:

$('body').on('click','#element',function(){
    //somthing
});

but we can say this is not the best way to do this. I suggest a another way to do this is use clone() method instead of using dynamic html. Write some html in you file for example:

<div id='div1'></div>

Now in the script tag make a clone of this div then all the properties of this div would follow with new element too. For Example:

var dynamicDiv = jQuery('#div1').clone(true);

Now use the element dynamicDiv wherever you want to add it or change its properties as you like. Now all jQuery functions will work with this element

Java 8 Streams: multiple filters vs. complex condition

This test shows that your second option can perform significantly better. Findings first, then the code:

one filter with predicate of form u -> exp1 && exp2, list size 10000000, averaged over 100 runs: LongSummaryStatistics{count=100, sum=4142, min=29, average=41.420000, max=82}
two filters with predicates of form u -> exp1, list size 10000000, averaged over 100 runs: LongSummaryStatistics{count=100, sum=13315, min=117, average=133.150000, max=153}
one filter with predicate of form predOne.and(pred2), list size 10000000, averaged over 100 runs: LongSummaryStatistics{count=100, sum=10320, min=82, average=103.200000, max=127}

now the code:

enum Gender {
    FEMALE,
    MALE
}

static class User {
    Gender gender;
    int age;

    public User(Gender gender, int age){
        this.gender = gender;
        this.age = age;
    }

    public Gender getGender() {
        return gender;
    }

    public void setGender(Gender gender) {
        this.gender = gender;
    }

    public int getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }
}

static long test1(List<User> users){
    long time1 = System.currentTimeMillis();
    users.stream()
            .filter((u) -> u.getGender() == Gender.FEMALE && u.getAge() % 2 == 0)
            .allMatch(u -> true);                   // least overhead terminal function I can think of
    long time2 = System.currentTimeMillis();
    return time2 - time1;
}

static long test2(List<User> users){
    long time1 = System.currentTimeMillis();
    users.stream()
            .filter(u -> u.getGender() == Gender.FEMALE)
            .filter(u -> u.getAge() % 2 == 0)
            .allMatch(u -> true);                   // least overhead terminal function I can think of
    long time2 = System.currentTimeMillis();
    return time2 - time1;
}

static long test3(List<User> users){
    long time1 = System.currentTimeMillis();
    users.stream()
            .filter(((Predicate<User>) u -> u.getGender() == Gender.FEMALE).and(u -> u.getAge() % 2 == 0))
            .allMatch(u -> true);                   // least overhead terminal function I can think of
    long time2 = System.currentTimeMillis();
    return time2 - time1;
}

public static void main(String... args) {
    int size = 10000000;
    List<User> users =
    IntStream.range(0,size)
            .mapToObj(i -> i % 2 == 0 ? new User(Gender.MALE, i % 100) : new User(Gender.FEMALE, i % 100))
            .collect(Collectors.toCollection(()->new ArrayList<>(size)));
    repeat("one filter with predicate of form u -> exp1 && exp2", users, Temp::test1, 100);
    repeat("two filters with predicates of form u -> exp1", users, Temp::test2, 100);
    repeat("one filter with predicate of form predOne.and(pred2)", users, Temp::test3, 100);
}

private static void repeat(String name, List<User> users, ToLongFunction<List<User>> test, int iterations) {
    System.out.println(name + ", list size " + users.size() + ", averaged over " + iterations + " runs: " + IntStream.range(0, iterations)
            .mapToLong(i -> test.applyAsLong(users))
            .summaryStatistics());
}

Extract hostname name from string

Was looking for a solution to this problem today. None of the above answers seemed to satisfy. I wanted a solution that could be a one liner, no conditional logic and nothing that had to be wrapped in a function.

Here's what I came up with, seems to work really well:

hostname="http://www.example.com:1234"
hostname.split("//").slice(-1)[0].split(":")[0].split('.').slice(-2).join('.')   // gives "example.com"

May look complicated at first glance, but it works pretty simply; the key is using 'slice(-n)' in a couple of places where the good part has to be pulled from the end of the split array (and [0] to get from the front of the split array).

Each of these tests return "example.com":

"http://example.com".split("//").slice(-1)[0].split(":")[0].split('.').slice(-2).join('.')
"http://example.com:1234".split("//").slice(-1)[0].split(":")[0].split('.').slice(-2).join('.')
"http://www.example.com:1234".split("//").slice(-1)[0].split(":")[0].split('.').slice(-2).join('.')
"http://foo.www.example.com:1234".split("//").slice(-1)[0].split(":")[0].split('.').slice(-2).join('.')

Tensorflow: Using Adam optimizer

You need to call tf.global_variables_initializer() on you session, like

init = tf.global_variables_initializer()
sess.run(init)

Full example is available in this great tutorial https://www.tensorflow.org/get_started/mnist/mechanics

Convert array of indices to 1-hot encoded numpy array

Using a Neuraxle pipeline step:

  1. Set up your example
import numpy as np
a = np.array([1,0,3])
b = np.array([[0,1,0,0], [1,0,0,0], [0,0,0,1]])
  1. Do the actual conversion
from neuraxle.steps.numpy import OneHotEncoder
encoder = OneHotEncoder(nb_columns=4)
b_pred = encoder.transform(a)
  1. Assert it works
assert b_pred == b

Link to documentation: neuraxle.steps.numpy.OneHotEncoder

Get first day of week in PHP?

Another way to do it....

$year = '2014';
$month = '02';
$day = '26';

$date = DateTime::createFromFormat('Y-m-d H:i:s', $year . '-' . $month . '-' . $day . '00:00:00');
$day = date('w', $date->getTimestamp());

// 0=Sunday 6=Saturday
if($day!=0){

   $newdate = $date->getTimestamp() - $day * 86400;  //86400 seconds in a day

   // Look for DST change 
   if($old = date('I', $date->getTimestamp()) != $new = date('I', $newdate)){
       if($old == 0){
           $newdate -= 3600;  //3600 seconds in an hour
       } else {
           $newdate += 3600;
       }
   }

   $date->setTimestamp($newdate);
}

echo $date->format('D Y-m-d H:i:s');

How to make in CSS an overlay over an image?

You could use a pseudo element for this, and have your image on a hover:

_x000D_
_x000D_
.image {_x000D_
  position: relative;_x000D_
  height: 300px;_x000D_
  width: 300px;_x000D_
  background: url(http://lorempixel.com/300/300);_x000D_
}_x000D_
.image:before {_x000D_
  content: "";_x000D_
  position: absolute;_x000D_
  top: 0;_x000D_
  left: 0;_x000D_
  height: 100%;_x000D_
  width: 100%;_x000D_
  transition: all 0.8s;_x000D_
  opacity: 0;_x000D_
  background: url(http://lorempixel.com/300/200);_x000D_
  background-size: 100% 100%;_x000D_
}_x000D_
.image:hover:before {_x000D_
  opacity: 0.8;_x000D_
}
_x000D_
<div class="image"></div>
_x000D_
_x000D_
_x000D_

How to establish a connection pool in JDBC?

Don't reinvent the wheel.

Try one of the readily available 3rd party components:

  • Apache DBCP - This one is used internally by Tomcat, and by yours truly.
  • c3p0

Apache DBCP comes with different example on how to setup a pooling javax.sql.DataSource. Here is one sample that can help you get started.

'Incorrect SET Options' Error When Building Database Project

For me, just setting the compatibility level to higher level works fine. To see C.Level :

select compatibility_level from sys.databases where name = [your_database]

How should I escape commas and speech marks in CSV files so they work in Excel?

According to Yashu's instructions, I wrote the following function (it's PL/SQL code, but it should be easily adaptable to any other language).

FUNCTION field(str IN VARCHAR2) RETURN VARCHAR2 IS
    C_NEWLINE CONSTANT CHAR(1) := '
'; -- newline is intentional

    v_aux VARCHAR2(32000);
    v_has_double_quotes BOOLEAN;
    v_has_comma BOOLEAN;
    v_has_newline BOOLEAN;
BEGIN
    v_has_double_quotes := instr(str, '"') > 0;
    v_has_comma := instr(str,',') > 0;
    v_has_newline := instr(str, C_NEWLINE) > 0;

    IF v_has_double_quotes OR v_has_comma OR v_has_newline THEN
        IF v_has_double_quotes THEN
            v_aux := replace(str,'"','""');
        ELSE
            v_aux := str;
        END IF;
        return '"'||v_aux||'"';
    ELSE
        return str;
    END IF;
END;

How do I parse a YAML file in Ruby?

Maybe I'm missing something, but why try to parse the file? Why not just load the YAML and examine the object(s) that result?

If your sample YAML is in some.yml, then this:

require 'yaml'
thing = YAML.load_file('some.yml')
puts thing.inspect

gives me

{"javascripts"=>[{"fo_global"=>["lazyload-min", "holla-min"]}]}

What is the difference between __init__ and __call__?

In Python, functions are first-class objects, this means: function references can be passed in inputs to other functions and/or methods, and executed from inside them.

Instances of Classes (aka Objects), can be treated as if they were functions: pass them to other methods/functions and call them. In order to achieve this, the __call__ class function has to be specialized.

def __call__(self, [args ...]) It takes as an input a variable number of arguments. Assuming x being an instance of the Class X, x.__call__(1, 2) is analogous to calling x(1,2) or the instance itself as a function.

In Python, __init__() is properly defined as Class Constructor (as well as __del__() is the Class Destructor). Therefore, there is a net distinction between __init__() and __call__(): the first builds an instance of Class up, the second makes such instance callable as a function would be without impacting the lifecycle of the object itself (i.e. __call__ does not impact the construction/destruction lifecycle) but it can modify its internal state (as shown below).

Example.

class Stuff(object):

    def __init__(self, x, y, range):
        super(Stuff, self).__init__()
        self.x = x
        self.y = y
        self.range = range

    def __call__(self, x, y):
        self.x = x
        self.y = y
        print '__call__ with (%d,%d)' % (self.x, self.y)

    def __del__(self):
        del self.x
        del self.y
        del self.range

>>> s = Stuff(1, 2, 3)
>>> s.x
1
>>> s(7, 8)
__call__ with (7,8)
>>> s.x
7

PHP 7 simpleXML

I'm using Bash on Windows (Ubuntu 16.04) and I just installed with php7.0-xml and all is working now for the Symfony 3.2.7 PHP requirements.

sudo apt-get install php7.0-xml

Slick Carousel Uncaught TypeError: $(...).slick is not a function

Old question, but I have only one recent jQuery file (v3.2.1) included (slick is also included, of course), and I still got this problem. I fixed it like this:

function initSlider(selector, options) {
    if ($.fn.slick) {
        $(selector).slick(options);
    } else {
        setTimeout(function() {
            initSlider(selector, options);
        }, 500);
    }
}

//example: initSlider('.references', {...slick's options...});

This function tries to apply slick 2 times a second and stops after get it working. I didn't analyze it deep, but I think slick's initialization is being deferred.

Mock HttpContext.Current in Test Init Method

If your application third party redirect internally, so it is better to mock HttpContext in below way :

HttpWorkerRequest initWorkerRequest = new SimpleWorkerRequest("","","","",new StringWriter(CultureInfo.InvariantCulture));
System.Web.HttpContext.Current = new HttpContext(initWorkerRequest);
System.Web.HttpContext.Current.Request.Browser = new HttpBrowserCapabilities();
System.Web.HttpContext.Current.Request.Browser.Capabilities = new Dictionary<string, string> { { "requiresPostRedirectionHandling", "false" } };

PUT vs. POST in REST

I like this advice, from RFC 2616's definition of PUT:

The fundamental difference between the POST and PUT requests is reflected in the different meaning of the Request-URI. The URI in a POST request identifies the resource that will handle the enclosed entity. That resource might be a data-accepting process, a gateway to some other protocol, or a separate entity that accepts annotations. In contrast, the URI in a PUT request identifies the entity enclosed with the request -- the user agent knows what URI is intended and the server MUST NOT attempt to apply the request to some other resource.

This jibes with the other advice here, that PUT is best applied to resources that already have a name, and POST is good for creating a new object under an existing resource (and letting the server name it).

I interpret this, and the idempotency requirements on PUT, to mean that:

  • POST is good for creating new objects under a collection (and create does not need to be idempotent)
  • PUT is good for updating existing objects (and update needs to be idempotent)
  • POST can also be used for non-idempotent updates to existing objects (especially, changing part of an object without specifying the whole thing -- if you think about it, creating a new member of a collection is actually a special case of this kind of update, from the collection's perspective)
  • PUT can also be used for create if and only if you allow the client to name the resource. But since REST clients aren't supposed to make assumptions about URL structure, this is less in the intended spirit of things.

Javascript Click on Element by Class

class of my button is "input-addon btn btn-default fileinput-exists"

below code helped me

document.querySelector('.input-addon.btn.btn-default.fileinput-exists').click();

but I want to click second button, I have two buttons in my screen so I used querySelectorAll

var elem = document.querySelectorAll('.input-addon.btn.btn-default.fileinput-exists');
                elem[1].click();

here elem[1] is the second button object that I want to click.

php exec command (or similar) to not wait for result

I know this question has been answered but the answers i found here didn't work for my scenario ( or for Windows ).

I am using windows 10 laptop with PHP 7.2 in Xampp v3.2.4.

$command = 'php Cron.php send_email "'. $id .'"';
if ( substr(php_uname(), 0, 7) == "Windows" )
{
    //windows
    pclose(popen("start /B " . $command . " 1> temp/update_log 2>&1 &", "r"));
}
else
{
    //linux
    shell_exec( $command . " > /dev/null 2>&1 &" );
}

This worked perfectly for me.

I hope it will help someone with windows. Cheers.

How should I load files into my Java application?

The short answer

Use one of these two methods:

For example:

InputStream inputStream = YourClass.class.getResourceAsStream("image.jpg");

--

The long answer

Typically, one would not want to load files using absolute paths. For example, don’t do this if you can help it:

File file = new File("C:\\Users\\Joe\\image.jpg");

This technique is not recommended for at least two reasons. First, it creates a dependency on a particular operating system, which prevents the application from easily moving to another operating system. One of Java’s main benefits is the ability to run the same bytecode on many different platforms. Using an absolute path like this makes the code much less portable.

Second, depending on the relative location of the file, this technique might create an external dependency and limit the application’s mobility. If the file exists outside the application’s current directory, this creates an external dependency and one would have to be aware of the dependency in order to move the application to another machine (error prone).

Instead, use the getResource() methods in the Class class. This makes the application much more portable. It can be moved to different platforms, machines, or directories and still function correctly.

Best way to test exceptions with Assert to ensure they will be thrown

With most .net unit testing frameworks you can put an [ExpectedException] attribute on the test method. However this can't tell you that the exception happened at the point you expected it to. That's where xunit.net can help.

With xunit you have Assert.Throws, so you can do things like this:

    [Fact]
    public void CantDecrementBasketLineQuantityBelowZero()
    {
        var o = new Basket();
        var p = new Product {Id = 1, NetPrice = 23.45m};
        o.AddProduct(p, 1);
        Assert.Throws<BusinessException>(() => o.SetProductQuantity(p, -3));
    }

[Fact] is the xunit equivalent of [TestMethod]

grep output to show only matching file

You can use the Unix-style -l switch – typically terse and cryptic – or the equivalent --files-with-matches – longer and more readable.

The output of grep --help is not easy to read, but it's there:

-l, --files-with-matches  print only names of FILEs containing matches

org.apache.http.conn.HttpHostConnectException: Connection to http://localhost refused in android

I am using PHP for webservice and Android 4.x. device for connecting to the webservice. I had similar problem where, using 10.0.2.2 worked well with emulator but failed to connect from device. The solution that worked for me is: Find IP of your computer ... say 192.168.0.103 Find the port of your apache ... say 8080 Now open httpd.conf and locate following line Listen 127.0.0.1:8080 After this line add following Listen 192.168.0.103:8080 Thats it. Now if you use 192.168.0.103:8080 in your android code, it will connect!!

How to find out client ID of component for ajax update/render? Cannot find component with expression "foo" referenced from "bar"

Try change update="insTable:display" to update="display". I believe you cannot prefix the id with the form ID like that.

php create object without class

you can always use new stdClass(). Example code:

   $object = new stdClass();
   $object->property = 'Here we go';

   var_dump($object);
   /*
   outputs:

   object(stdClass)#2 (1) {
      ["property"]=>
      string(10) "Here we go"
    }
   */

Also as of PHP 5.4 you can get same output with:

$object = (object) ['property' => 'Here we go'];

What is the equivalent to a JavaScript setInterval/setTimeout in Android/Java?

I was creating a mp3 player for android, I wanted to update the current time every 500ms so I did it like this

setInterval

private void update() {
    new android.os.Handler().postDelayed(new Runnable() {
        @Override
        public void run() {
            long cur = player.getCurrentPosition();
            long dur = player.getDuration();
            currentTime = millisecondsToTime(cur);
            currentTimeView.setText(currentTime);
            if (cur < dur) {
                updatePlayer();
            }

            // update seekbar
            seekBar.setProgress( (int) Math.round((float)cur / (float)dur * 100f));
        }
    }, 500);
}

which calls the same method recursively

How to parse JSON boolean value?

Try this:

{
    "ACCOUNT_EXIST": true,
    "MultipleContacts": false
}

boolean success ((Boolean) jsonObject.get("ACCOUNT_EXIST")).booleanValue()

Accessing the last entry in a Map

To answer your question in one sentence:

Per default, Maps don't have a last entry, it's not part of their contract.


And a side note: it's good practice to code against interfaces, not the implementation classes (see Effective Java by Joshua Bloch, Chapter 8, Item 52: Refer to objects by their interfaces).

So your declaration should read:

Map<String,Integer> map = new HashMap<String,Integer>();

(All maps share a common contract, so the client need not know what kind of map it is, unless he specifies a sub interface with an extended contract).


Possible Solutions

Sorted Maps:

There is a sub interface SortedMap that extends the map interface with order-based lookup methods and it has a sub interface NavigableMap that extends it even further. The standard implementation of this interface, TreeMap, allows you to sort entries either by natural ordering (if they implement the Comparable interface) or by a supplied Comparator.

You can access the last entry through the lastEntry method:

NavigableMap<String,Integer> map = new TreeMap<String, Integer>();
// add some entries
Entry<String, Integer> lastEntry = map.lastEntry();

Linked maps:

There is also the special case of LinkedHashMap, a HashMap implementation that stores the order in which keys are inserted. There is however no interface to back up this functionality, nor is there a direct way to access the last key. You can only do it through tricks such as using a List in between:

Map<String,String> map = new LinkedHashMap<String, Integer>();
// add some entries
List<Entry<String,Integer>> entryList =
    new ArrayList<Map.Entry<String, Integer>>(map.entrySet());
Entry<String, Integer> lastEntry =
    entryList.get(entryList.size()-1);

Proper Solution:

Since you don't control the insertion order, you should go with the NavigableMap interface, i.e. you would write a comparator that positions the Not-Specified entry last.

Here is an example:

final NavigableMap<String,Integer> map = 
        new TreeMap<String, Integer>(new Comparator<String>() {
    public int compare(final String o1, final String o2) {
        int result;
        if("Not-Specified".equals(o1)) {
            result=1;
        } else if("Not-Specified".equals(o2)) {
            result=-1;
        } else {
            result =o1.compareTo(o2);
        }
        return result;
    }

});
map.put("test", Integer.valueOf(2));
map.put("Not-Specified", Integer.valueOf(1));
map.put("testtest", Integer.valueOf(3));
final Entry<String, Integer> lastEntry = map.lastEntry();
System.out.println("Last key: "+lastEntry.getKey()
         + ", last value: "+lastEntry.getValue());

Output:

Last key: Not-Specified, last value: 1

Solution using HashMap:

If you must rely on HashMaps, there is still a solution, using a) a modified version of the above comparator, b) a List initialized with the Map's entrySet and c) the Collections.sort() helper method:

    final Map<String, Integer> map = new HashMap<String, Integer>();
    map.put("test", Integer.valueOf(2));
    map.put("Not-Specified", Integer.valueOf(1));
    map.put("testtest", Integer.valueOf(3));

    final List<Entry<String, Integer>> entries =
        new ArrayList<Entry<String, Integer>>(map.entrySet());
    Collections.sort(entries, new Comparator<Entry<String, Integer>>(){

        public int compareKeys(final String o1, final String o2){
            int result;
            if("Not-Specified".equals(o1)){
                result = 1;
            } else if("Not-Specified".equals(o2)){
                result = -1;
            } else{
                result = o1.compareTo(o2);
            }
            return result;
        }

        @Override
        public int compare(final Entry<String, Integer> o1,
            final Entry<String, Integer> o2){
            return this.compareKeys(o1.getKey(), o2.getKey());
        }

    });

    final Entry<String, Integer> lastEntry =
        entries.get(entries.size() - 1);
    System.out.println("Last key: " + lastEntry.getKey() + ", last value: "
        + lastEntry.getValue());

}

Output:

Last key: Not-Specified, last value: 1

What is the proper REST response code for a valid request but an empty data?

404 would be very confusing for any client if you return just because there is no data in response.

For me, Response Code 200 with an empty body is sufficient enough to understand that everything is perfect but there is no data matching the requirements.

Create a date from day month and year with T-SQL

Try this query:

    SELECT SUBSTRING(CONVERT(VARCHAR,JOINGDATE,103),7,4)AS
    YEAR,SUBSTRING(CONVERT(VARCHAR,JOINGDATE,100),1,2)AS
MONTH,SUBSTRING(CONVERT(VARCHAR,JOINGDATE,100),4,3)AS DATE FROM EMPLOYEE1

Result:

2014    Ja    1
2015    Ja    1
2014    Ja    1
2015    Ja    1
2012    Ja    1
2010    Ja    1
2015    Ja    1

What are the default color values for the Holo theme on Android 4.0?

If you want the default colors of Android ICS, you just have to go to your Android SDK and look for this path: platforms\android-15\data\res\values\colors.xml.

Here you go:

<!-- For holo theme -->
    <drawable name="screen_background_holo_light">#fff3f3f3</drawable>
    <drawable name="screen_background_holo_dark">#ff000000</drawable>
    <color name="background_holo_dark">#ff000000</color>
    <color name="background_holo_light">#fff3f3f3</color>
    <color name="bright_foreground_holo_dark">@android:color/background_holo_light</color>
    <color name="bright_foreground_holo_light">@android:color/background_holo_dark</color>
    <color name="bright_foreground_disabled_holo_dark">#ff4c4c4c</color>
    <color name="bright_foreground_disabled_holo_light">#ffb2b2b2</color>
    <color name="bright_foreground_inverse_holo_dark">@android:color/bright_foreground_holo_light</color>
    <color name="bright_foreground_inverse_holo_light">@android:color/bright_foreground_holo_dark</color>
    <color name="dim_foreground_holo_dark">#bebebe</color>
    <color name="dim_foreground_disabled_holo_dark">#80bebebe</color>
    <color name="dim_foreground_inverse_holo_dark">#323232</color>
    <color name="dim_foreground_inverse_disabled_holo_dark">#80323232</color>
    <color name="hint_foreground_holo_dark">#808080</color>
    <color name="dim_foreground_holo_light">#323232</color>
    <color name="dim_foreground_disabled_holo_light">#80323232</color>
    <color name="dim_foreground_inverse_holo_light">#bebebe</color>
    <color name="dim_foreground_inverse_disabled_holo_light">#80bebebe</color>
    <color name="hint_foreground_holo_light">#808080</color>
    <color name="highlighted_text_holo_dark">#6633b5e5</color>
    <color name="highlighted_text_holo_light">#6633b5e5</color>
    <color name="link_text_holo_dark">#5c5cff</color>
    <color name="link_text_holo_light">#0000ee</color>

This for the Background:

<color name="background_holo_dark">#ff000000</color>
<color name="background_holo_light">#fff3f3f3</color>

You won't get the same colors if you look this up in Photoshop etc. because they are set up with Alpha values.

Update for API Level 19:

<resources>
    <drawable name="screen_background_light">#ffffffff</drawable>
    <drawable name="screen_background_dark">#ff000000</drawable>
    <drawable name="status_bar_closed_default_background">#ff000000</drawable>
    <drawable name="status_bar_opened_default_background">#ff000000</drawable>
    <drawable name="notification_item_background_color">#ff111111</drawable>
    <drawable name="notification_item_background_color_pressed">#ff454545</drawable>
    <drawable name="search_bar_default_color">#ff000000</drawable>
    <drawable name="safe_mode_background">#60000000</drawable>
    <!-- Background drawable that can be used for a transparent activity to
         be able to display a dark UI: this darkens its background to make
         a dark (default theme) UI more visible. -->
    <drawable name="screen_background_dark_transparent">#80000000</drawable>
    <!-- Background drawable that can be used for a transparent activity to
         be able to display a light UI: this lightens its background to make
         a light UI more visible. -->
    <drawable name="screen_background_light_transparent">#80ffffff</drawable>
    <color name="safe_mode_text">#80ffffff</color>
    <color name="white">#ffffffff</color>
    <color name="black">#ff000000</color>
    <color name="transparent">#00000000</color>
    <color name="background_dark">#ff000000</color>
    <color name="background_light">#ffffffff</color>
    <color name="bright_foreground_dark">@android:color/background_light</color>
    <color name="bright_foreground_light">@android:color/background_dark</color>
    <color name="bright_foreground_dark_disabled">#80ffffff</color>
    <color name="bright_foreground_light_disabled">#80000000</color>
    <color name="bright_foreground_dark_inverse">@android:color/bright_foreground_light</color>
    <color name="bright_foreground_light_inverse">@android:color/bright_foreground_dark</color>
    <color name="dim_foreground_dark">#bebebe</color>
    <color name="dim_foreground_dark_disabled">#80bebebe</color>
    <color name="dim_foreground_dark_inverse">#323232</color>
    <color name="dim_foreground_dark_inverse_disabled">#80323232</color>
    <color name="hint_foreground_dark">#808080</color>
    <color name="dim_foreground_light">#323232</color>
    <color name="dim_foreground_light_disabled">#80323232</color>
    <color name="dim_foreground_light_inverse">#bebebe</color>
    <color name="dim_foreground_light_inverse_disabled">#80bebebe</color>
    <color name="hint_foreground_light">#808080</color>
    <color name="highlighted_text_dark">#9983CC39</color>
    <color name="highlighted_text_light">#9983CC39</color>
    <color name="link_text_dark">#5c5cff</color>
    <color name="link_text_light">#0000ee</color>
    <color name="suggestion_highlight_text">#177bbd</color>

    <drawable name="stat_notify_sync_noanim">@drawable/stat_notify_sync_anim0</drawable>
    <drawable name="stat_sys_download_done">@drawable/stat_sys_download_done_static</drawable>
    <drawable name="stat_sys_upload_done">@drawable/stat_sys_upload_anim0</drawable>
    <drawable name="dialog_frame">@drawable/panel_background</drawable>
    <drawable name="alert_dark_frame">@drawable/popup_full_dark</drawable>
    <drawable name="alert_light_frame">@drawable/popup_full_bright</drawable>
    <drawable name="menu_frame">@drawable/menu_background</drawable>
    <drawable name="menu_full_frame">@drawable/menu_background_fill_parent_width</drawable>
    <drawable name="editbox_dropdown_dark_frame">@drawable/editbox_dropdown_background_dark</drawable>
    <drawable name="editbox_dropdown_light_frame">@drawable/editbox_dropdown_background</drawable>

    <drawable name="dialog_holo_dark_frame">@drawable/dialog_full_holo_dark</drawable>
    <drawable name="dialog_holo_light_frame">@drawable/dialog_full_holo_light</drawable>

    <drawable name="input_method_fullscreen_background">#fff9f9f9</drawable>
    <drawable name="input_method_fullscreen_background_holo">@drawable/screen_background_holo_dark</drawable>
    <color name="input_method_navigation_guard">#ff000000</color>

    <!-- For date picker widget -->
    <drawable name="selected_day_background">#ff0092f4</drawable>

    <!-- For settings framework -->
    <color name="lighter_gray">#ddd</color>
    <color name="darker_gray">#aaa</color>

    <!-- For security permissions -->
    <color name="perms_dangerous_grp_color">#33b5e5</color>
    <color name="perms_dangerous_perm_color">#33b5e5</color>
    <color name="shadow">#cc222222</color>
    <color name="perms_costs_money">#ffffbb33</color>

    <!-- For search-related UIs -->
    <color name="search_url_text_normal">#7fa87f</color>
    <color name="search_url_text_selected">@android:color/black</color>
    <color name="search_url_text_pressed">@android:color/black</color>
    <color name="search_widget_corpus_item_background">@android:color/lighter_gray</color>

    <!-- SlidingTab -->
    <color name="sliding_tab_text_color_active">@android:color/black</color>
    <color name="sliding_tab_text_color_shadow">@android:color/black</color>

    <!-- keyguard tab -->
    <color name="keyguard_text_color_normal">#ffffff</color>
    <color name="keyguard_text_color_unlock">#a7d84c</color>
    <color name="keyguard_text_color_soundoff">#ffffff</color>
    <color name="keyguard_text_color_soundon">#e69310</color>
    <color name="keyguard_text_color_decline">#fe0a5a</color>

    <!-- keyguard clock -->
    <color name="lockscreen_clock_background">#ffffffff</color>
    <color name="lockscreen_clock_foreground">#ffffffff</color>
    <color name="lockscreen_clock_am_pm">#ffffffff</color>
    <color name="lockscreen_owner_info">#ff9a9a9a</color>

    <!-- keyguard overscroll widget pager -->
    <color name="kg_multi_user_text_active">#ffffffff</color>
    <color name="kg_multi_user_text_inactive">#ff808080</color>
    <color name="kg_widget_pager_gradient">#ffffffff</color>

    <!-- FaceLock -->
    <color name="facelock_spotlight_mask">#CC000000</color>

    <!-- For holo theme -->
      <drawable name="screen_background_holo_light">#fff3f3f3</drawable>
      <drawable name="screen_background_holo_dark">#ff000000</drawable>
    <color name="background_holo_dark">#ff000000</color>
    <color name="background_holo_light">#fff3f3f3</color>
    <color name="bright_foreground_holo_dark">@android:color/background_holo_light</color>
    <color name="bright_foreground_holo_light">@android:color/background_holo_dark</color>
    <color name="bright_foreground_disabled_holo_dark">#ff4c4c4c</color>
    <color name="bright_foreground_disabled_holo_light">#ffb2b2b2</color>
    <color name="bright_foreground_inverse_holo_dark">@android:color/bright_foreground_holo_light</color>
    <color name="bright_foreground_inverse_holo_light">@android:color/bright_foreground_holo_dark</color>
    <color name="dim_foreground_holo_dark">#bebebe</color>
    <color name="dim_foreground_disabled_holo_dark">#80bebebe</color>
    <color name="dim_foreground_inverse_holo_dark">#323232</color>
    <color name="dim_foreground_inverse_disabled_holo_dark">#80323232</color>
    <color name="hint_foreground_holo_dark">#808080</color>
    <color name="dim_foreground_holo_light">#323232</color>
    <color name="dim_foreground_disabled_holo_light">#80323232</color>
    <color name="dim_foreground_inverse_holo_light">#bebebe</color>
    <color name="dim_foreground_inverse_disabled_holo_light">#80bebebe</color>
    <color name="hint_foreground_holo_light">#808080</color>
    <color name="highlighted_text_holo_dark">#6633b5e5</color>
    <color name="highlighted_text_holo_light">#6633b5e5</color>
    <color name="link_text_holo_dark">#5c5cff</color>
    <color name="link_text_holo_light">#0000ee</color>

    <!-- Group buttons -->
    <eat-comment />
    <color name="group_button_dialog_pressed_holo_dark">#46c5c1ff</color>
    <color name="group_button_dialog_focused_holo_dark">#2699cc00</color>

    <color name="group_button_dialog_pressed_holo_light">#ffffffff</color>
    <color name="group_button_dialog_focused_holo_light">#4699cc00</color>

    <!-- Highlight colors for the legacy themes -->
    <eat-comment />
    <color name="legacy_pressed_highlight">#fffeaa0c</color>
    <color name="legacy_selected_highlight">#fff17a0a</color>
    <color name="legacy_long_pressed_highlight">#ffffffff</color>

    <!-- General purpose colors for Holo-themed elements -->
    <eat-comment />

    <!-- A light Holo shade of blue -->
    <color name="holo_blue_light">#ff33b5e5</color>
    <!-- A light Holo shade of gray -->
    <color name="holo_gray_light">#33999999</color>
    <!-- A light Holo shade of green -->
    <color name="holo_green_light">#ff99cc00</color>
    <!-- A light Holo shade of red -->
    <color name="holo_red_light">#ffff4444</color>
    <!-- A dark Holo shade of blue -->
    <color name="holo_blue_dark">#ff0099cc</color>
    <!-- A dark Holo shade of green -->
    <color name="holo_green_dark">#ff669900</color>
    <!-- A dark Holo shade of red -->
    <color name="holo_red_dark">#ffcc0000</color>
    <!-- A Holo shade of purple -->
    <color name="holo_purple">#ffaa66cc</color>
    <!-- A light Holo shade of orange -->
    <color name="holo_orange_light">#ffffbb33</color>
    <!-- A dark Holo shade of orange -->
    <color name="holo_orange_dark">#ffff8800</color>
    <!-- A really bright Holo shade of blue -->
    <color name="holo_blue_bright">#ff00ddff</color>
    <!-- A really bright Holo shade of gray -->
    <color name="holo_gray_bright">#33CCCCCC</color>

    <drawable name="notification_template_icon_bg">#3333B5E5</drawable>
    <drawable name="notification_template_icon_low_bg">#0cffffff</drawable>

    <!-- Keyguard colors -->
    <color name="keyguard_avatar_frame_color">#ffffffff</color>
    <color name="keyguard_avatar_frame_shadow_color">#80000000</color>
    <color name="keyguard_avatar_nick_color">#ffffffff</color>
    <color name="keyguard_avatar_frame_pressed_color">#ff35b5e5</color>

    <color name="accessibility_focus_highlight">#80ffff00</color>
</resources>

Checking if a variable is defined?

Also, you can check if it's defined while in a string via interpolation, if you code:

puts "Is array1 defined and what type is it? #{defined?(@array1)}"

The system will tell you the type if it is defined. If it is not defined it will just return a warning saying the variable is not initialized.

Hope this helps! :)

Can a CSS class inherit one or more other classes?

Perfect timing: I went from this question to my email, to find an article about Less, a Ruby library that among other things does this:

Since super looks just like footer, but with a different font, I'll use Less's class inclusion technique (they call it a mixin) to tell it to include these declarations too:

#super {
  #footer;
  font-family: cursive;
}

Convert a date format in epoch

tl;dr

ZonedDateTime.parse( 
                        "Jun 13 2003 23:11:52.454 UTC" , 
                        DateTimeFormatter.ofPattern ( "MMM d uuuu HH:mm:ss.SSS z" ) 
                    )
              .toInstant()
              .toEpochMilli()

1055545912454

java.time

This Answer expands on the Answer by Lockni.

DateTimeFormatter

First define a formatting pattern to match your input string by creating a DateTimeFormatter object.

String input = "Jun 13 2003 23:11:52.454 UTC";
DateTimeFormatter f = DateTimeFormatter.ofPattern ( "MMM d uuuu HH:mm:ss.SSS z" );

ZonedDateTime

Parse the string as a ZonedDateTime. You can think of that class as: ( Instant + ZoneId ).

ZonedDateTime zdt = ZonedDateTime.parse ( "Jun 13 2003 23:11:52.454 UTC" , f );

zdt.toString(): 2003-06-13T23:11:52.454Z[UTC]

Table of types of date-time classes in modern java.time versus legacy.

Count-from-epoch

I do not recommend tracking date-time values as a count-from-epoch. Doing so makes debugging tricky as humans cannot discern a meaningful date-time from a number so invalid/unexpected values may slip by. Also such counts are ambiguous, in granularity (whole seconds, milli, micro, nano, etc.) and in epoch (at least two dozen in by various computer systems).

But if you insist you can get a count of milliseconds from the epoch of first moment of 1970 in UTC (1970-01-01T00:00:00) through the Instant class. Be aware this means data-loss as you are truncating any nanoseconds to milliseconds.

Instant instant = zdt.toInstant ();

instant.toString(): 2003-06-13T23:11:52.454Z

long millisSinceEpoch = instant.toEpochMilli() ; 

1055545912454


About java.time

The java.time framework is built into Java 8 and later. These classes supplant the troublesome old legacy date-time classes such as java.util.Date, Calendar, & SimpleDateFormat.

To learn more, see the Oracle Tutorial. And search Stack Overflow for many examples and explanations. Specification is JSR 310.

The Joda-Time project, now in maintenance mode, advises migration to the java.time classes.

You may exchange java.time objects directly with your database. Use a JDBC driver compliant with JDBC 4.2 or later. No need for strings, no need for java.sql.* classes.

Where to obtain the java.time classes?

The ThreeTen-Extra project extends java.time with additional classes. This project is a proving ground for possible future additions to java.time. You may find some useful classes here such as Interval, YearWeek, YearQuarter, and more.

How to remove an app with active device admin enabled on Android?

You could also create a new DevicePolicyManager and then use removeAdmin(adminReceiver) from an onClickListener of a button in your app

//set the onClickListener here
{
   ComponentName devAdminReceiver = new ComponentName(context, deviceAdminReceiver.class);
   DevicePolicyManager dpm = (DevicePolicyManager)context.getSystemService(Context.DEVICE_POLICY_SERVICE);
   dpm.removeActiveAdmin(devAdminReceiver);
}

And then you can uninstall

Update query with PDO and MySQL

Your update syntax is incorrect. Please check Update Syntax for the correct syntax.

$sql = "UPDATE `access_users` set `contact_first_name` = :firstname,  `contact_surname` = :surname, `contact_email` = :email, `telephone` = :telephone";

How to round double to nearest whole number and then convert to a float?

float b = (float)Math.ceil(a); or float b = (float)Math.round(a);

Depending on whether you meant "round to the nearest whole number" (round) or "round up" (ceil).

Beware of loss of precision in converting a double to a float, but that shouldn't be an issue here.

Make a link use POST instead of GET

This is an old question, but none of the answers satisfy the request in-full. So I'm adding another answer.

The requested code, as I understand, should make only one change to the way normal hyperlinks work: the POST method should be used instead of GET. The immediate implications would be:

  1. When the link is clicked we should reload the tab to the url of the href
  2. As the method is POST, we should have no query string in the URL of the target page we load
  3. That page should receive the data in parameters (names and value) by POST

I am using jquery here, but this could be done with native apis (harder and longer of course).

<html>
<head>
    <script src="path/to/jquery.min.js" type="text/javascript"></script>
    <script>
        $(document).ready(function() {

            $("a.post").click(function(e) {
                e.stopPropagation();
                e.preventDefault();
                var href = this.href;
                var parts = href.split('?');
                var url = parts[0];
                var params = parts[1].split('&');
                var pp, inputs = '';
                for(var i = 0, n = params.length; i < n; i++) {
                    pp = params[i].split('=');
                    inputs += '<input type="hidden" name="' + pp[0] + '" value="' + pp[1] + '" />';
                }
                $("body").append('<form action="'+url+'" method="post" id="poster">'+inputs+'</form>');
                $("#poster").submit();
            });
        });
    </script>
</head>
<body>
    <a class="post" href="reflector.php?color=blue&weight=340&model=x-12&price=14.800">Post it!</a><br/>
    <a href="reflector.php?color=blue&weight=340&model=x-12&price=14.800">Normal link</a>
</body>
</html>

And to see the result, save the following as reflector.php in the same directory you have the above saved.

<h2>Get</h2>
<pre>
<?php print_r($_GET); ?>
</pre>

<h2>Post</h2>
<pre>
<?php print_r($_POST); ?>
</pre>

Display the current time and date in an Android application

My own working solution:

Calendar c = Calendar.getInstance();

String sDate = c.get(Calendar.YEAR) + "-" 
+ c.get(Calendar.MONTH)
+ "-" + c.get(Calendar.DAY_OF_MONTH) 
+ " at " + c.get(Calendar.HOUR_OF_DAY) 
+ ":" + c.get(Calendar.MINUTE);

Hope this helps!

Guid is all 0's (zeros)?

In the spirit of being complete, the answers that instruct you to use Guid.NewGuid() are correct.

In addressing your subsequent edit, you'll need to post the code for your RequestObject class. I'm suspecting that your guid property is not marked as a DataMember, and thus is not being serialized over the wire. Since default(Guid) is the same as new Guid() (i.e. all 0's), this would explain the behavior you're seeing.

How can I execute a PHP function in a form action?

In PHP functions will not be evaluated inside strings, because there are different rules for variables.

<?php
function name() {
  return 'Mark';
}

echo 'My name is: name()';   // Output: My name is name()
echo 'My name is: '. name(); // Output: My name is Mark

The action parameter to the tag in HTML should not reference the PHP function you want to run. Action should refer to a page on the web server that will process the form input and return new HTML to the user. This can be the same location as the PHP script that outputs the form, or some people prefer to make a separate PHP file to handle actions.

The basic process is the same either way:

  1. Generate HTML form to the user.
  2. User fills in the form, clicks submit.
  3. The form data is sent to the locations defined by action on the server.
  4. The script validates the data and does something with it.
  5. Usually a new HTML page is returned.

A simple example would be:

<?php
// $_POST is a magic PHP variable that will always contain
// any form data that was posted to this page.
// We check here to see if the textfield called 'name' had
// some data entered into it, if so we process it, if not we
// output the form.
if (isset($_POST['name'])) {
  print_name($_POST['name']);
}
else {
  print_form();
}

// In this function we print the name the user provided.
function print_name($name) {
  // $name should be validated and checked here depending on use.
  // In this case we just HTML escape it so nothing nasty should
  // be able to get through:
  echo 'Your name is: '. htmlentities($name);
}

// This function is called when no name was sent to us over HTTP.
function print_form() {
  echo '
    <form name="form1" method="post" action="">
    <p><label><input type="text" name="name" id="textfield"></label></p>
    <p><label><input type="submit" name="button" id="button" value="Submit"></label></p>
    </form>
  ';
}
?>

For future information I recommend reading the PHP tutorials: http://php.net/tut.php

There is even a section about Dealing with forms.

How to delete Project from Google Developers Console

For me only way to delete project was switch language to English (UK) - from Polish and then button "DELETE" worked. If anyone have problem with not working or missing options in Google Cloud Platform I suggest switching to english after that everything works like charm...

Object comparison in JavaScript

Here is my ES3 commented solution (gory details after the code):

function object_equals( x, y ) {
  if ( x === y ) return true;
    // if both x and y are null or undefined and exactly the same

  if ( ! ( x instanceof Object ) || ! ( y instanceof Object ) ) return false;
    // if they are not strictly equal, they both need to be Objects

  if ( x.constructor !== y.constructor ) return false;
    // they must have the exact same prototype chain, the closest we can do is
    // test there constructor.

  for ( var p in x ) {
    if ( ! x.hasOwnProperty( p ) ) continue;
      // other properties were tested using x.constructor === y.constructor

    if ( ! y.hasOwnProperty( p ) ) return false;
      // allows to compare x[ p ] and y[ p ] when set to undefined

    if ( x[ p ] === y[ p ] ) continue;
      // if they have the same strict value or identity then they are equal

    if ( typeof( x[ p ] ) !== "object" ) return false;
      // Numbers, Strings, Functions, Booleans must be strictly equal

    if ( ! object_equals( x[ p ],  y[ p ] ) ) return false;
      // Objects and Arrays must be tested recursively
  }

  for ( p in y )
    if ( y.hasOwnProperty( p ) && ! x.hasOwnProperty( p ) )
      return false;
        // allows x[ p ] to be set to undefined

  return true;
}

In developing this solution, I took a particular look at corner cases, efficiency, yet trying to yield a simple solution that works, hopefully with some elegance. JavaScript allows both null and undefined properties and objects have prototypes chains that can lead to very different behaviors if not checked.

First I have chosen to not extend Object.prototype, mostly because null could not be one of the objects of the comparison and that I believe that null should be a valid object to compare with another. There are also other legitimate concerns noted by others regarding the extension of Object.prototype regarding possible side effects on other's code.

Special care must taken to deal the possibility that JavaScript allows object properties can be set to undefined, i.e. there exists properties which values are set to undefined. The above solution verifies that both objects have the same properties set to undefined to report equality. This can only be accomplished by checking the existence of properties using Object.hasOwnProperty( property_name ). Also note that JSON.stringify() removes properties that are set to undefined, and that therefore comparisons using this form will ignore properties set to the value undefined.

Functions should be considered equal only if they share the same reference, not just the same code, because this would not take into account these functions prototype. So comparing the code string does not work to guaranty that they have the same prototype object.

The two objects should have the same prototype chain, not just the same properties. This can only be tested cross-browser by comparing the constructor of both objects for strict equality. ECMAScript 5 would allow to test their actual prototype using Object.getPrototypeOf(). Some web browsers also offer a __proto__ property that does the same thing. A possible improvement of the above code would allow to use one of these methods whenever available.

The use of strict comparisons is paramount here because 2 should not be considered equal to "2.0000", nor false should be considered equal to null, undefined, or 0.

Efficiency considerations lead me to compare for equality of properties as soon as possible. Then, only if that failed, look for the typeof these properties. The speed boost could be significant on large objects with lots of scalar properties.

No more that two loops are required, the first to check properties from the left object, the second to check properties from the right and verify only existence (not value), to catch these properties which are defined with the undefined value.

Overall this code handles most corner cases in only 16 lines of code (without comments).


Update (8/13/2015). I have implemented a better version, as the function value_equals() that is faster, handles properly corner cases such as NaN and 0 different than -0, optionally enforcing objects' properties order and testing for cyclic references, backed by more than 100 automated tests as part of the Toubkal project test suite.

multiple conditions for filter in spark data frames

You can try, (filtering with 1 object like a list or a set of values)

ds = ds.filter(functions.col(COL_NAME).isin(myList));

or as @Tony Fraser suggested, you can try, (with a Seq of objects)

ds = ds.filter(functions.col(COL_NAME).isin(mySeq));

All the answers are correct but most of them do not represent a good coding style. Also, you should always consider the variable length of arguments for the future, even though they are static at a certain point in time.

What is it exactly a BLOB in a DBMS context

They are binary large objects, you can use them to store binary data such as images or serialized objects among other things.

Why can I not create a wheel in python?

I also ran into this all of a sudden, after it had previously worked, and it was because I was inside a virtualenv, and wheel wasn’t installed in the virtualenv.

Print a file, skipping the first X lines, in Bash

Use the sed delete command with a range address. For example:

sed 1,100d file.txt # Print file.txt omitting lines 1-100.

Alternatively, if you want to only print a known range, use the print command with the -n flag:

sed -n 201,300p file.txt # Print lines 201-300 from file.txt

This solution should work reliably on all Unix systems, regardless of the presence of GNU utilities.

load scripts asynchronously

Well, x.parentNode returns the HEAD element, so you are inserting the script just before the head tag. Maybe that's the problem.

Try x.parentNode.appendChild() instead.

How to find the difference in days between two dates?

This is the simplest i managed to get working on centos 7:

OLDDATE="2018-12-31"
TODAY=$(date -d $(date +%Y-%m-%d) '+%s')
LINUXDATE=$(date -d "$OLDDATE" '+%s')
DIFFDAYS=$(( ($TODAY - $LINUXDATE) / (60*60*24) ))

echo $DIFFDAYS

Saving image from PHP URL

I wasn't able to get any of the other solutions to work, but I was able to use wget:

$tempDir = '/download/file/here';
$finalDir = '/keep/file/here';
$imageUrl = 'http://www.example.com/image.jpg';

exec("cd $tempDir && wget --quiet $imageUrl");

if (!file_exists("$tempDir/image.jpg")) {
    throw new Exception('Failed while trying to download image');
}

if (rename("$tempDir/image.jpg", "$finalDir/new-image-name.jpg") === false) {
    throw new Exception('Failed while trying to move image file from temp dir to final dir');
}

Check if url contains string with JQuery

if(window.location.href.indexOf("?added-to-cart=555") >= 0)

It's window.location.href, not window.location.

How can I add JAR files to the web-inf/lib folder in Eclipse?

Found a solution. This problem happens, when you import a project.

The solution is simple

  1. Right click -> Properties
  2. Project Facets -> Check Dyanmic Web Module and Java Version
  3. Apply Setting.

Now you should see the web app libraries showing your jars added.

Pythonic way to check if a list is sorted or not

more_itertools.is_sorted

I'm not sure when this was added, but this hasn't been mentioned yet:

import more_itertools

ls = [1, 4, 2]

print(more_itertools.is_sorted(ls))

ls2 = ["ab", "c", "def"]

print(more_itertools.is_sorted(ls2, key=len))

HTML table needs spacing between columns, not rows

The better approach uses Shredder's css rule: padding: 0 15px 0 15px only instead of inline css, define a css rule that applies to all tds. Do This by using a style tag in your page:

<style type="text/css">
td
{
    padding:0 15px;
}
</style>

or give the table a class like "paddingBetweenCols" and in the site css use

.paddingBetweenCols td
{
    padding:0 15px;
}

The site css approach defines a central rule that can be reused by all pages.

If your doing to use the site css approach, it would be best to define a class like above and apply the padding to the class...unless you want all td's on the entire site to have the same rule applied.

Fiddle for using style tag

Fiddle for using site css

Capturing URL parameters in request.GET

You might as well check request.META dictionary to access many useful things like PATH_INFO, QUERY_STRING

# for example
request.META['QUERY_STRING']

# or to avoid any exceptions provide a fallback

request.META.get('QUERY_STRING', False)

you said that it returns empty query dict

I think you need to tune your url to accept required or optional args or kwargs Django got you all the power you need with regrex like:

url(r'^project_config/(?P<product>\w+)/$', views.foo),

more about this at django-optional-url-parameters

Undo working copy modifications of one file in Git?

Just use

git checkout filename

This will replace filename with the latest version from the current branch.

WARNING: your changes will be discarded — no backup is kept.

How can I generate a 6 digit unique number?

This will generate random 6 digit number

_x000D_
_x000D_
<?php_x000D_
    mt_rand(100000,999999);_x000D_
?>
_x000D_
_x000D_
_x000D_

How to set a Fragment tag by code?

You can provide a tag inside your activity layout xml file.

Supply the android:tag attribute with a unique string.

Just as you would assign an id in a layout xml.

    android:tag="unique_tag"

link to developer guide

Can I pass an argument to a VBScript (vbs file launched with cscript)?

To answer your bonus question, the general answer is no, you don't need to set variables to "Nothing" in short .VBS scripts like yours, that get called by Wscript or Cscript.

The reason you might do this in the middle of a longer script is to release memory back to the operating system that VB would otherwise have been holding. These days when 8GB of RAM is typical and 16GB+ relatively common, this is unlikely to produce any measurable impact, even on a huge script that has several megabytes in a single variable. At this point it's kind of a hold-over from the days where you might have been working in 1MB or 2MB of RAM.

You're correct, the moment your .VBS script completes, all of your variables get destroyed and the memory is reclaimed anyway. Setting variables to "Nothing" simply speeds up that process, and allows you to do it in the middle of a script.

Best way to read a large file into a byte array in C#?

Depending on the frequency of operations, the size of the files, and the number of files you're looking at, there are other performance issues to take into consideration. One thing to remember, is that each of your byte arrays will be released at the mercy of the garbage collector. If you're not caching any of that data, you could end up creating a lot of garbage and be losing most of your performance to % Time in GC. If the chunks are larger than 85K, you'll be allocating to the Large Object Heap(LOH) which will require a collection of all generations to free up (this is very expensive, and on a server will stop all execution while it's going on). Additionally, if you have a ton of objects on the LOH, you can end up with LOH fragmentation (the LOH is never compacted) which leads to poor performance and out of memory exceptions. You can recycle the process once you hit a certain point, but I don't know if that's a best practice.

The point is, you should consider the full life cycle of your app before necessarily just reading all the bytes into memory the fastest way possible or you might be trading short term performance for overall performance.

How do I concatenate multiple C++ strings on one line?

You would have to define operator+() for every data type you would want to concenate to the string, yet since operator<< is defined for most types, you should use std::stringstream.

Damn, beat by 50 seconds...

PostgreSQL: role is not permitted to log in

Using pgadmin4 :

  1. Select roles in side menu
  2. Select properties in dashboard.
  3. Click Edit and select privileges

Now there you can enable or disable login, roles and other options

What is SELF JOIN and when would you use it?

Well, one classic example is where you wanted to get a list of employees and their immediate managers:

select e.employee as employee, b.employee as boss
from emptable e, emptable b
where e.manager_id = b.empolyee_id
order by 1

It's basically used where there is any relationship between rows stored in the same table.

  • employees.
  • multi-level marketing.
  • machine parts.

And so on...

What causes a SIGSEGV

using an invalid/null pointer? Overrunning the bounds of an array? Kindof hard to be specific without any sample code.

Essentially, you are attempting to access memory that doesn't belong to your program, so the OS kills it.

Printing the correct number of decimal points with cout

Simplify the accepted answer

Simplified example:

#include <iostream>
#include <iomanip>

int main()
{
    double d = 122.345;
    std::cout << std::fixed << std::setprecision(2) << d;
}

And you will get output

122.34

Reference:

How to build and fill pandas dataframe from for loop?

Try this using list comprehension:

import pandas as pd

df = pd.DataFrame(
    [p, p.team, p.passing_att, p.passer_rating()] for p in game.players.passing()
)

What is tail recursion?

here is a Perl 5 version of the tailrecsum function mentioned earlier.

sub tail_rec_sum($;$){
  my( $x,$running_total ) = (@_,0);

  return $running_total unless $x;

  @_ = ($x-1,$running_total+$x);
  goto &tail_rec_sum; # throw away current stack frame
}

Where do alpha testers download Google Play Android apps?

  1. Publish your alpha apk by pressing the submit button.

  2. Wait until it's published.
    (e.g.: CURRENT APK published on Apr 28, 2015, 2:20:13AM)

  3. Select Alpha testers - click Manage list of testers.

  4. Share the link with your testers (by email).
    (e.g.: https://play.google.com/apps/testing/uk.co.xxxxx.xxxxx)

Download/Stream file from URL - asp.net

The accepted solution from Dallas was working for us if we use Load Balancer on the Citrix Netscaler (without WAF policy).

The download of the file doesn't work through the LB of the Netscaler when it is associated with WAF as the current scenario (Content-length not being correct) is a RFC violation and AppFW resets the connection, which doesn't happen when WAF policy is not associated.

So what was missing was:

Response.End();

See also: Trying to stream a PDF file with asp.net is producing a "damaged file"

How To Pass GET Parameters To Laravel From With GET Method ?

Router

Route::get('search/{id}', ['as' => 'search', 'uses' => 'SearchController@search']);

Controller

class SearchController extends BaseController {

    public function search(Request $request){

        $id= $request->id ; // or any params

        ...
    }
}

Open an image using URI in Android's default gallery image viewer

My solution

Intent intent = new Intent();
intent.setAction(Intent.ACTION_VIEW);
intent.setDataAndType(Uri.fromFile(new File(Environment.getExternalStorageDirectory().getPath()+"/your_app_folder/"+"your_picture_saved_name"+".png")), "image/*");
context.startActivity(intent);

array.select() in javascript

Underscore.js is a good library for these sorts of operations - it uses the builtin routines such as Array.filter if available, or uses its own if not.

http://documentcloud.github.com/underscore/

The docs will give an idea of use - the javascript lambda syntax is nowhere near as succinct as ruby or others (I always forget to add an explicit return statement for example) and scope is another easy way to get caught out, but you can do most things quite easily with the exception of constructs such as lazy list comprehensions.

From the docs for .select() (.filter() is an alias for the same)

Looks through each value in the list, returning an array of all the values that pass a truth test (iterator). Delegates to the native filter method, if it exists.

  var evens = _.select([1, 2, 3, 4, 5, 6], function(num){ return num % 2 == 0; });
  => [2, 4, 6]

How to create new folder?

You probably want os.makedirs as it will create intermediate directories as well, if needed.

import os

#dir is not keyword
def makemydir(whatever):
  try:
    os.makedirs(whatever)
  except OSError:
    pass
  # let exception propagate if we just can't
  # cd into the specified directory
  os.chdir(whatever)

how to find host name from IP with out login to the host

You can do a reverse DNS lookup with host, too. Just give it the IP address as an argument:

$ host 192.168.0.10
server10 has address 192.168.0.10

Root user/sudo equivalent in Cygwin?

Being unhappy with the available solution, I adopted nu774's script to add security and make it easier to setup and use. The project is available on Github

To use it, just download cygwin-sudo.py and run it via python3 cygwin-sudo.py **yourcommand**.

You can set up an alias for convenience:

alias sudo="python3 /path-to-cygwin-sudo/cygwin-sudo.py"

What is the difference between new/delete and malloc/free?

also,

the global new and delete can be overridden, malloc/free cannot.

further more new and delete can be overridden per type.

Why is Ant giving me a Unsupported major.minor version error

go to run option--->select external tool option ---->external tool configuration---> select ant build ----> select your build.xml --->there you will find JDK option--->select your required JRE.

Regular expression for address field validation

Regular expression for simple address validation

^[#.0-9a-zA-Z\s,-]+$

E.g. for Address match case

#1, North Street, Chennai - 11 

E.g. for Address not match case

$1, North Street, Chennai @ 11

How to delete a file from SD card?

Also you have to give permission if you are using >1.6 SDK

uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"

in AndroidManifest.xml file

Get domain name from given url

There is a similar question Extract main domain name from a given url. If you take a look at this answer , you will see that it is very easy. You just need to use java.net.URL and String utility - Split

Fail to create Android virtual Device, "No system image installed for this Target"

I had android sdk and android studio installed separately in my system. Android studio had installed its own sdk. After I deleted the stand-alone android sdk, the issue of "“No system image installed for this Target” was gone.

Integrate ZXing in Android Studio

I was integrating ZXING into an Android application and there were no good sources for the input all over, I will give you a hint on what worked for me - because it turned out to be very easy.

There is a real handy git repository that provides the zxing android library project as an AAR archive.

All you have to do is add this to your build.gradle

repositories {
    jcenter()
}

dependencies {
    implementation 'com.journeyapps:zxing-android-embedded:3.0.2@aar'
    implementation 'com.google.zxing:core:3.2.0'
}

and Gradle does all the magic to compile the code and makes it accessible in your app.

To start the Scanner afterwards, use this class/method: From the Activity:

new IntentIntegrator(this).initiateScan(); // `this` is the current Activity

From a Fragment:

IntentIntegrator.forFragment(this).initiateScan(); // `this` is the current Fragment
// If you're using the support library, use IntentIntegrator.forSupportFragment(this) instead.

There are several customizing options:

IntentIntegrator integrator = new IntentIntegrator(this);
integrator.setDesiredBarcodeFormats(IntentIntegrator.ONE_D_CODE_TYPES);
integrator.setPrompt("Scan a barcode");
integrator.setCameraId(0);  // Use a specific camera of the device
integrator.setBeepEnabled(false);
integrator.setBarcodeImageEnabled(true);
integrator.initiateScan();

They have a sample-project and are providing several integration examples:

If you already visited the link you going to see that I just copy&pasted the code from the git README. If not, go there to get some more insight and code examples.

How do you check if a JavaScript Object is a DOM Object?

if you are using jQuery, try this

$('<div>').is('*') // true
$({tagName: 'a'}).is('*') // false
$({}).is('*') // false
$([]).is('*') // false
$(0).is('*') // false
$(NaN).is('*') // false

mysql data directory location

If you install MySQL via homebrew on MacOS, you might need to delete your old data directory /usr/local/var/mysql. Otherwise, it will fail during the initialization process with the following error:

==> /usr/local/Cellar/mysql/8.0.16/bin/mysqld --initialize-insecure --user=hohoho --basedir=/usr/local/Cellar/mysql/8.0.16 --datadir=/usr/local/var/mysql --tmpdir=/tmp
2019-07-17T16:30:51.828887Z 0 [System] [MY-013169] [Server] /usr/local/Cellar/mysql/8.0.16/bin/mysqld (mysqld 8.0.16) initializing of server in progress as process 93487
2019-07-17T16:30:51.830375Z 0 [ERROR] [MY-010457] [Server] --initialize specified but the data directory has files in it. Aborting.
2019-07-17T16:30:51.830381Z 0 [ERROR] [MY-013236] [Server] Newly created data directory /usr/local/var/mysql/ is unusable. You can safely remove it.
2019-07-17T16:30:51.830410Z 0 [ERROR] [MY-010119] [Server] Aborting
2019-07-17T16:30:51.830540Z 0 [System] [MY-010910] [Server] /usr/local/Cellar/mysql/8.0.16/bin/mysqld: Shutdown complete (mysqld 8.0.16)  Homebrew.

How to cast/convert pointer to reference in C++

Call it like this:

foo(*ob);

Note that there is no casting going on here, as suggested in your question title. All we have done is de-referenced the pointer to the object which we then pass to the function.

python: how to get information about a function?

You can use pydoc.

Open your terminal and type python -m pydoc list.append

The advantage of pydoc over help() is that you do not have to import a module to look at its help text. For instance python -m pydoc random.randint.

Also you can start an HTTP server to interactively browse documentation by typing python -m pydoc -b (python 3)

For more information python -m pydoc

No matching client found for package name (Google Analytics) - multiple productFlavors & buildTypes

make sure your package name in "google-services.json" file is same with your apps's package name.

Read specific columns with pandas or other python module

Got a solution to above problem in a different way where in although i would read entire csv file, but would tweek the display part to show only the content which is desired.

import pandas as pd

df = pd.read_csv('data.csv', skipinitialspace=True)
print df[['star_name', 'ra']]

This one could help in some of the scenario's in learning basics and filtering data on the basis of columns in dataframe.

How to add a button to UINavigationBar?

The answers above are good, but I'd like to flesh them out with a few more tips:

If you want to modify the title of the back button (the arrow-y looking one at the left of the navigation bar) you MUST do it in the PREVIOUS view controller, not the one for which it will display. It's like saying "hey, if you ever push another view controller on top of this one, call the back button "Back" (or whatever) instead of the default."

If you want to hide the back button during a special state, such as while a UIPickerView is displayed, use self.navigationItem.hidesBackButton = YES; and remember to set it back when you leave the special state.

If you want to display one of the special symbolic buttons, use the form initWithBarButtonSystemItem:target:action with a value like UIBarButtonSystemItemAdd

Remember, the meaning of that symbol is up to you, but be careful of the Human Interface Guidelines. Using UIBarButtonSystemItemAdd to mean deleting an item will probably get your application rejected.

Get first letter of a string from column

Cast the dtype of the col to str and you can perform vectorised slicing calling str:

In [29]:
df['new_col'] = df['First'].astype(str).str[0]
df

Out[29]:
   First  Second new_col
0    123     234       1
1     22    4353       2
2     32     355       3
3    453     453       4
4     45     345       4
5    453     453       4
6     56      56       5

if you need to you can cast the dtype back again calling astype(int) on the column

Compiler error "archive for required library could not be read" - Spring Tool Suite

This happens when Eclipse screws up. To fix it, delete all the files in:

workspace/.metadata/.plugins/org.eclipse.jdt.core

Amazon products API - Looking for basic overview and information

Your post contains several questions, so I'll try to answer them one at a time:

  1. The API you're interested in is the Product Advertising API (PA). It allows you programmatic access to search and retrieve product information from Amazon's catalog. If you're having trouble finding information on the API, that's because the web service has undergone two name changes in recent history: it was also known as ECS and AAWS.
  2. The signature process you're referring to is the same HMAC signature that all of the other AWS services use for authentication. All that's required to sign your requests to the Product Advertising API is a function to compute a SHA-1 hash and and AWS developer key. For more information, see the section of the developer documentation on signing requests.
  3. As far as I know, there is no support for retrieving RSS feeds of products or tags through PA. If anyone has information suggesting otherwise, please correct me.
  4. Either the REST or SOAP APIs should make your use case very straight forward. Amazon provides a fairly basic "getting started" guide available here. As well, you can view the complete API developer documentation here.

Although the documentation is a little hard to find (likely due to all the name changes), the PA API is very well documented and rather elegant. With a modicum of elbow grease and some previous experience in calling out to web services, you shouldn't have any trouble getting the information you need from the API.

a tag as a submit button?

Try this code:

<form id="myform">
  <!-- form elements -->
  <a href="#" onclick="document.getElementById('myform').submit()">Submit</a>
</form>

But users with disabled JavaScript won't be able to submit the form, so you could add the following code:

<noscript>
  <input type="submit" value="Submit form!" />
</noscript>

Cannot send a content-body with this verb-type

Please set the request Content Type before you read the response stream;

 request.ContentType = "text/xml";

How to use lifecycle method getDerivedStateFromProps as opposed to componentWillReceiveProps

About the removal of componentWillReceiveProps: you should be able to handle its uses with a combination of getDerivedStateFromProps and componentDidUpdate, see the React blog post for example migrations. And yes, the object returned by getDerivedStateFromProps updates the state similarly to an object passed to setState.

In case you really need the old value of a prop, you can always cache it in your state with something like this:

state = {
  cachedSomeProp: null
  // ... rest of initial state
};

static getDerivedStateFromProps(nextProps, prevState) {
  // do things with nextProps.someProp and prevState.cachedSomeProp
  return {
    cachedSomeProp: nextProps.someProp,
    // ... other derived state properties
  };
}

Anything that doesn't affect the state can be put in componentDidUpdate, and there's even a getSnapshotBeforeUpdate for very low-level stuff.

UPDATE: To get a feel for the new (and old) lifecycle methods, the react-lifecycle-visualizer package may be helpful.

Setting environment variables in Linux using Bash

The reason people often suggest writing

VAR=value
export VAR

instead of the shorter

export VAR=value

is that the longer form works in more different shells than the short form. If you know you're dealing with bash, either works fine, of course.

How to use font-family lato?

Download it from here and extract LatoOFL.rar then go to TTF and open this font-face-generator click at Choose File choose font which you want to use and click at generate then download it and then go html file open it and you see the code like this

@font-face {
        font-family: "Lato Black";
        src: url('698242188-Lato-Bla.eot');
        src: url('698242188-Lato-Bla.eot?#iefix') format('embedded-opentype'),
        url('698242188-Lato-Bla.svg#Lato Black') format('svg'),
        url('698242188-Lato-Bla.woff') format('woff'),
        url('698242188-Lato-Bla.ttf') format('truetype');
        font-weight: normal;
        font-style: normal;
}
body{
    font-family: "Lato Black";
    direction: ltr;
}

change the src code and give the url where your this font directory placed, now you can use it at your website...

If you don't want to download it use this

<link type='text/css' href='http://fonts.googleapis.com/css?family=Lato:400,700' />

What does void* mean and how to use it?

C11 standard (n1570) §6.2.2.3 al1 p55 says :

A pointer to void may be converted to or from a pointer to any object type. A pointer to any object type may be converted to a pointer to void and back again; the result shall compare equal to the original pointer.

You can use this generic pointer to store a pointer to any object type, but you can't use usual arithmetic operations with it and you can't deference it.

Find a value anywhere in a database

Based on bnkdev's answer I modified Narayana's Code to search all columns even numeric ones.

It'll run slower, but this version actually finds all matches not just those found in text columns.

I can't thank this guy enough. Saved me days of searching by hand!

CREATE PROC SearchAllTables 
(
@SearchStr nvarchar(100)
)
AS
BEGIN

-- Copyright © 2002 Narayana Vyas Kondreddi. All rights reserved.
-- Purpose: To search all columns of all tables for a given search string
-- Written by: Narayana Vyas Kondreddi
-- Site: http://vyaskn.tripod.com
-- Tested on: SQL Server 7.0 and SQL Server 2000
-- Date modified: 28th July 2002 22:50 GMT


CREATE TABLE #Results (ColumnName nvarchar(370), ColumnValue nvarchar(3630))

SET NOCOUNT ON

DECLARE @TableName nvarchar(256), @ColumnName nvarchar(128), @SearchStr2 nvarchar(110)
SET  @TableName = ''
SET @SearchStr2 = QUOTENAME('%' + @SearchStr + '%','''')

WHILE @TableName IS NOT NULL
BEGIN
    SET @ColumnName = ''
    SET @TableName = 
    (
        SELECT MIN(QUOTENAME(TABLE_SCHEMA) + '.' + QUOTENAME(TABLE_NAME))
        FROM    INFORMATION_SCHEMA.TABLES
        WHERE       TABLE_TYPE = 'BASE TABLE'
            AND QUOTENAME(TABLE_SCHEMA) + '.' + QUOTENAME(TABLE_NAME) > @TableName
            AND OBJECTPROPERTY(
                    OBJECT_ID(
                        QUOTENAME(TABLE_SCHEMA) + '.' + QUOTENAME(TABLE_NAME)
                         ), 'IsMSShipped'
                           ) = 0
    )

    WHILE (@TableName IS NOT NULL) AND (@ColumnName IS NOT NULL)
    BEGIN
        SET @ColumnName =
        (
            SELECT MIN(QUOTENAME(COLUMN_NAME))
            FROM    INFORMATION_SCHEMA.COLUMNS
            WHERE       TABLE_SCHEMA    = PARSENAME(@TableName, 2)
                AND TABLE_NAME  = PARSENAME(@TableName, 1)                  
                AND QUOTENAME(COLUMN_NAME) > @ColumnName
        )

        IF @ColumnName IS NOT NULL
        BEGIN
            INSERT INTO #Results
            EXEC
            (
                'SELECT ''' + @TableName + '.' + @ColumnName + ''', LEFT(CONVERT(varchar(max), ' + @ColumnName + '), 3630) 
                FROM ' + @TableName + ' (NOLOCK) ' +
                ' WHERE CONVERT(varchar(max), ' + @ColumnName + ') LIKE ' + @SearchStr2
            )
        END
    END 
END

SELECT ColumnName, ColumnValue FROM #Results
END

Best approach to converting Boolean object to string in java

public class Sandbox {

    /**
     * @param args the command line arguments
     */
    public static void main(String[] args) {
        Boolean b = true;
        boolean z = false;
        echo (b);
        echo (z);
        echo ("Value of b= " + b +"\nValue of z= " + z);
    }

    public static void echo(Object obj){
        System.out.println(obj);
    } 

}
Result
--------------
true
false
Value of b= true
Value of z= false
--------------

Fastest way to copy a file in Node.js

For fast copies you should use the fs.constants.COPYFILE_FICLONE flag. It allows (for filesystems that support this) to not actually copy the content of the file. Just a new file entry is created, but it points to a Copy-on-Write "clone" of the source file.

To do nothing/less is the fastest way of doing something ;)

https://nodejs.org/api/fs.html#fs_fs_copyfile_src_dest_flags_callback

let fs = require("fs");

fs.copyFile(
  "source.txt",
  "destination.txt",
  fs.constants.COPYFILE_FICLONE,
  (err) => {
    if (err) {
      // TODO: handle error
      console.log("error");
    }
    console.log("success");
  }
);

Using promises instead:

let fs = require("fs");
let util = require("util");
let copyFile = util.promisify(fs.copyFile);


copyFile(
  "source.txt",
  "destination.txt",
  fs.constants.COPYFILE_FICLONE
)
  .catch(() => console.log("error"))
  .then(() => console.log("success"));

Angular 2 Scroll to bottom (Chat style)

In angular using material design sidenav I had to use the following:

let ele = document.getElementsByClassName('md-sidenav-content');
    let eleArray = <Element[]>Array.prototype.slice.call(ele);
    eleArray.map( val => {
        val.scrollTop = val.scrollHeight;
    });

How can you flush a write using a file descriptor?

I think what you are looking for may be

int fsync(int fd);

or

int fdatasync(int fd);

fsync will flush the file from kernel buffer to the disk. fdatasync will also do except for the meta data.

Hibernate Query By Example and Projections

The problem seems to happen when you have an alias the same name as the objects property. Hibernate seems to pick up the alias and use it in the sql. I found this documented here and here, and I believe it to be a bug in Hibernate, although I am not sure that the Hibernate team agrees.

Either way, I have found a simple work around that works in my case. Your mileage may vary. The details are below, I tried to simplify the code for this sample so I apologize for any errors or typo's:

Criteria criteria = session.createCriteria(MyClass.class)
    .setProjection(Projections.projectionList()
        .add(Projections.property("sectionHeader"), "sectionHeader")
        .add(Projections.property("subSectionHeader"), "subSectionHeader")
        .add(Projections.property("sectionNumber"), "sectionNumber"))
    .add(Restrictions.ilike("sectionHeader", sectionHeaderVar)) // <- Problem!
    .setResultTransformer(Transformers.aliasToBean(MyDTO.class));

Would produce this sql:

select
    this_.SECTION_HEADER as y1_,
    this_.SUB_SECTION_HEADER as y2_,
    this_.SECTION_NUMBER as y3_,
from
    MY_TABLE this_ 
where
    ( lower(y1_) like ? ) 

Which was causing an error: java.sql.SQLException: ORA-00904: "Y1_": invalid identifier

But, when I changed my restriction to use "this", like so:

Criteria criteria = session.createCriteria(MyClass.class)
    .setProjection(Projections.projectionList()
        .add(Projections.property("sectionHeader"), "sectionHeader")
        .add(Projections.property("subSectionHeader"), "subSectionHeader")
        .add(Projections.property("sectionNumber"), "sectionNumber"))
    .add(Restrictions.ilike("this.sectionHeader", sectionHeaderVar)) // <- Problem Solved!
    .setResultTransformer(Transformers.aliasToBean(MyDTO.class));

It produced the following sql and my problem was solved.

select
    this_.SECTION_HEADER as y1_,
    this_.SUB_SECTION_HEADER as y2_,
    this_.SECTION_NUMBER as y3_,
from
    MY_TABLE this_ 
where
    ( lower(this_.SECTION_HEADER) like ? ) 

Thats, it! A pretty simple fix to a painful problem. I don't know how this fix would translate to the query by example problem, but it may get you closer.

Center content vertically on Vuetify

Here's another approach using Vuetify grid system available in Vuetify 2.x: https://vuetifyjs.com/en/components/grids

<v-container>
    <v-row align="center">
        Hello I am center to vertically using "grid".
    </v-row>
</v-container>

How to concatenate two strings in C++?

If you were programming in C, then assuming name really is a fixed-length array like you say, you have to do something like the following:

char filename[sizeof(name) + 4];
strcpy (filename, name) ;
strcat (filename, ".txt") ;
FILE* fp = fopen (filename,...

You see now why everybody recommends std::string?

How to concatenate characters in java?

Do you want to make a string out of them?

String s = new StringBuilder().append(char1).append(char2).append(char3).toString();

Note that

String b = "b";
String s = "a" + b + "c";

Actually compiles to

String s = new StringBuilder("a").append(b).append("c").toString();

Edit: as litb pointed out, you can also do this:

"" + char1 + char2 + char3;

That compiles to the following:

new StringBuilder().append("").append(c).append(c1).append(c2).toString();

Edit (2): Corrected string append comparison since, as cletus points out, a series of strings is handled by the compiler.

The purpose of the above is to illustrate what the compiler does, not to tell you what you should do.

How to include view/partial specific styling in AngularJS

@sz3, funny enough today I had to do exactly what you were trying to achieve: 'load a specific CSS file only when a user access' a specific page. So I used the solution above.

But I am here to answer your last question: 'where exactly should I put the code. Any ideas?'

You were right including the code into the resolve, but you need to change a bit the format.

Take a look at the code below:

.when('/home', {
  title:'Home - ' + siteName,
  bodyClass: 'home',
  templateUrl: function(params) {
    return 'views/home.html';
  },
  controler: 'homeCtrl',
  resolve: {
    style : function(){
      /* check if already exists first - note ID used on link element*/
      /* could also track within scope object*/
      if( !angular.element('link#mobile').length){
        angular.element('head').append('<link id="home" href="home.css" rel="stylesheet">');
      }
    }
  }
})

I've just tested and it's working fine, it injects the html and it loads my 'home.css' only when I hit the '/home' route.

Full explanation can be found here, but basically resolve: should get an object in the format

{
  'key' : string or function()
} 

You can name the 'key' anything you like - in my case I called 'style'.

Then for the value you have two options:

  • If it's a string, then it is an alias for a service.

  • If it's function, then it is injected and the return value is treated as the dependency.

The main point here is that the code inside the function is going to be executed before before the controller is instantiated and the $routeChangeSuccess event is fired.

Hope that helps.

How do you run a .bat file from PHP?

<?php
exec('c:\WINDOWS\system32\cmd.exe /c START C:\Program Files\VideoLAN\VLC\vlc.bat');
?>

How to convert a JSON string to a dictionary?

Swift 5

extension String {
    func convertToDictionary() -> [String: Any]? {
        if let data = data(using: .utf8) {
            return try? JSONSerialization.jsonObject(with: data, options: []) as? [String: Any]
        }
        return nil
    }
}

What is the equivalent of Select Case in Access SQL?

You can use IIF for a similar result.

Note that you can nest the IIF statements to handle multiple cases. There is an example here: http://forums.devshed.com/database-management-46/query-ms-access-iif-statement-multiple-conditions-358130.html

SELECT IIf([Combinaison] = "Mike", 12, IIf([Combinaison] = "Steve", 13)) As Answer 
FROM MyTable;

How does the "this" keyword work?

"this" is all about scope. Every function has its own scope, and since everything in JS is an object, even a function can store some values into itself using "this". OOP 101 teaches that "this" is only applicable to instances of an object. Therefore, every-time a function executes, a new "instance" of that function has a new meaning of "this".

Most people get confused when they try to use "this" inside of anonymous closure functions like:

(function(value) {
    this.value = value;
    $('.some-elements').each(function(elt){
        elt.innerHTML = this.value;        // uh oh!! possibly undefined
    });
})(2);

So here, inside each(), "this" doesn't hold the "value" that you expect it to (from

this.value = value;
above it). So, to get over this (no pun intended) problem, a developer could:

(function(value) {
    var self = this;            // small change
    self.value = value;
    $('.some-elements').each(function(elt){
        elt.innerHTML = self.value;        // phew!! == 2 
    });
})(2);

Try it out; you'll begin to like this pattern of programming

Java Timestamp - How can I create a Timestamp with the date 23/09/2007?

By Timestamp, I presume you mean java.sql.Timestamp. You will notice that this class has a constructor that accepts a long argument. You can parse this using the DateFormat class:

DateFormat dateFormat = new SimpleDateFormat("dd/MM/yyyy");
Date date = dateFormat.parse("23/09/2007");
long time = date.getTime();
new Timestamp(time);

Getting ORA-01031: insufficient privileges while querying a table instead of ORA-00942: table or view does not exist

ORA-01031: insufficient privileges Solution: Go to Your System User. then Write This Code:

SQL> grant dba to UserName; //Put This username which user show this error message.

Grant succeeded.

CSS selector for disabled input type="submit"

I used @jensgram solution to hide a div that contains a disabled input. So I hide the entire parent of the input.

Here is the code :

div:has(>input[disabled=disabled]) {
    display: none;
}

Maybe it could help some of you.

How to align entire html body to the center?

If I have one thing that I love to share with respect to CSS, it's MY FAVE WAY OF CENTERING THINGS ALONG BOTH AXES!!!

Advantages of this method:

  1. Full compatibility with browsers that people actually use
  2. No tables required
  3. Highly reusable for centering any other elements inside their parent
  4. Accomodates parents and children with dynamic (changing) dimensions!

I always do this by using 2 classes: One to specify the parent element, whose content will be centered (.centered-wrapper), and the 2nd one to specify which child of the parent is centered (.centered-content). This 2nd class is useful in the case where the parent has multiple children, but only 1 needs to be centered). In this case, body will be the .centered-wrapper, and an inner div will be .centered-content.

<html>
    <head>...</head>
    <body class="centered-wrapper">
        <div class="centered-content">...</div>
    </body>
</html>

The idea for centering will now be to make .centered-content an inline-block. This will easily facilitate horizontal centering, through text-align: center;, and also allows for vertical centering as you shall see.

.centered-wrapper {
    position: relative;
    text-align: center;
}
.centered-wrapper:before {
    content: "";
    position: relative;
    display: inline-block;
    width: 0; height: 100%;
    vertical-align: middle;
}
.centered-content {
    display: inline-block;
    vertical-align: middle;
}

This gives you 2 really reusable classes for centering any child inside of any parent! Just add the .centered-wrapper and .centered-content classes.

So, what's up with that :before element? It facilitates vertical-align: middle; and is necessary because vertical alignment isn't relative to the height of the parent - vertical alignment is relative to the height of the tallest sibling!!!. Therefore, by ensuring that there is a sibling whose height is the parent's height (100% height, 0 width to make it invisible), we know that vertical alignment will be with respect to the parent's height.

One last thing: You need to ensure that your html and body tags are the size of the window so that centering to them is the same as centering to the browser!

html, body {
    width: 100%;
    height: 100%;
    padding: 0;
    margin: 0;
}

Fiddle: https://jsfiddle.net/gershy/g121g72a/

Is true == 1 and false == 0 in JavaScript?

with == you are essentially comparing whether a variable is falsey when comparing to false or truthey when comparing to true. If you use ===, it will compare the exact value of the variables so true will not === 1

Reading a List from properties file and load with spring annotation @Value

Have you considered @Autowireding the constructor or a setter and String.split()ing in the body?

class MyClass {
    private List<String> myList;

    @Autowired
    public MyClass(@Value("${my.list.of.strings}") final String strs) {
        myList = Arrays.asList(strs.split(","));
    }

    //or

    @Autowired
    public void setMyList(@Value("${my.list.of.strings}") final String strs) {
        myList = Arrays.asList(strs.split(","));
    }
}

I tend to prefer doing my autowiring in one of these ways to enhance the testability of my code.

Java switch statement multiple cases

Sadly, it's not possible in Java. You'll have to resort to using if-else statements.

How do I get a plist as a Dictionary in Swift?

This answer uses Swift native objects rather than NSDictionary.

Swift 3.0

//get the path of the plist file
guard let plistPath = Bundle.main.path(forResource: "level1", ofType: "plist") else { return }
//load the plist as data in memory
guard let plistData = FileManager.default.contents(atPath: plistPath) else { return }
//use the format of a property list (xml)
var format = PropertyListSerialization.PropertyListFormat.xml
//convert the plist data to a Swift Dictionary
guard let  plistDict = try! PropertyListSerialization.propertyList(from: plistData, options: .mutableContainersAndLeaves, format: &format) as? [String : AnyObject] else { return }
//access the values in the dictionary 
if let value = plistDict["aKey"] as? String {
  //do something with your value
  print(value)
}
//you can also use the coalesce operator to handle possible nil values
var myValue = plistDict["aKey"] ?? ""

Convenient way to parse incoming multipart/form-data parameters in a Servlet

multipart/form-data encoded requests are indeed not by default supported by the Servlet API prior to version 3.0. The Servlet API parses the parameters by default using application/x-www-form-urlencoded encoding. When using a different encoding, the request.getParameter() calls will all return null. When you're already on Servlet 3.0 (Glassfish 3, Tomcat 7, etc), then you can use HttpServletRequest#getParts() instead. Also see this blog for extended examples.

Prior to Servlet 3.0, a de facto standard to parse multipart/form-data requests would be using Apache Commons FileUpload. Just carefully read its User Guide and Frequently Asked Questions sections to learn how to use it. I've posted an answer with a code example before here (it also contains an example targeting Servlet 3.0).

Regular expression for only characters a-z, A-Z

Piggybacking on what the other answers say, since you don't know how to do them at all, here's an example of how you might do it in JavaScript:

var charactersOnly = "This contains only characters";
var nonCharacters = "This has _@#*($()*@#$(*@%^_(#@!$ non-characters";

if (charactersOnly.search(/[^a-zA-Z]+/) === -1) {
  alert("Only characters");
}

if (nonCharacters.search(/[^a-zA-Z]+/)) {
  alert("There are non characters.");
}

The / starting and ending the regular expression signify that it's a regular expression. The search function takes both strings and regexes, so the / are necessary to specify a regex.

From the MDN Docs, the function returns -1 if there is no match.

Also note: that this works for only a-z, A-Z. If there are spaces, it will fail.

How do you disable viewport zooming on Mobile Safari?

@mattis is correct that iOS 10 Safari won't allow you to disable pinch to zoom with the user-scalable attribute. However, I got it to disable using preventDefault on the 'gesturestart' event. I've only verified this on Safari in iOS 10.0.2.

document.addEventListener('gesturestart', function (e) {
    e.preventDefault();
});

Where is debug.keystore in Android Studio

If you find that you do not have JDK installed. Go to your android terminal and navigate to the bin folder of JRE that comes with Android Studio.

C:\Program Files\Android\Android Studio\jre\bin

and run the following command. Remember to replace USERNAME with your actual PC username.

keytool -list -v -keystore "C:\Users\USERNAME\.android\debug.keystore" -alias androiddebugkey -storepass android -keypass android

Disable form auto submit on button click

<button>'s are in fact submit buttons, they have no other main functionality. You will have to set the type to button.
But if you bind your event handler like below, you target all buttons and do not have to do it manually for each button!

$('form button').on("click",function(e){
    e.preventDefault();
});

Android button with icon and text

You can use the Material Components Library and the MaterialButton component.
Use the app:icon and app:iconGravity="start" attributes.

Something like:

  <com.google.android.material.button.MaterialButton
        style="@style/Widget.MaterialComponents.Button.Icon"
        app:icon="@drawable/..."
        app:iconGravity="start"
        ../>

enter image description here